The document summarizes an experiment on a small shell and tube heat exchanger. Two technical objectives were tested: 1) varying the tube side flow rate while keeping the shell side constant, and 2) varying the shell side flow rate while keeping the tube side constant. Key results showed that increasing the flow rate on either side decreased temperatures and increased the heat transfer coefficient. The heat loss to the environment initially increased with flow before decreasing at the highest flow rate tested.
iaetsd Heat transfer enhancement of shell and tube heat exchanger using conic...Iaetsd Iaetsd
This document discusses heat transfer enhancement in a shell and tube heat exchanger using a conical tape insert. It provides heat transfer and friction factor data from experiments using the heat exchanger fitted with a helical tape insert. Hot air was passed through the inner tube while cold water flowed in the annulus. The helical insert increased heat transfer rate by up to 165% compared to the plain tube, with some increase in pressure drop. Equations and calculations are provided for determining heat transfer coefficients, pressure drops, and other parameters on both the shell and tube sides of the heat exchanger. Graphs of results are also presented.
This document provides an overview of Kern's method for designing shell-and-tube heat exchangers. It begins with objectives and an introduction to Kern's method. It then outlines the design procedure algorithm and provides an example application. The example involves designing an exchanger to sub-cool methanol condensate using brackish water as the coolant. The document walks through each step of the Kern's method design process for this example, including calculating properties, determining duties, selecting tube/shell parameters, and estimating heat transfer coefficients.
Heat exchangers transfer thermal energy between two or more fluids at different temperatures. They are classified based on their transfer process, geometry, heat transfer mechanism, and flow arrangement. Shell-and-tube heat exchangers consist of a set of tubes in a shell container and are the most important type, used across many industries. Their design involves calculating the heat transfer rate, selecting appropriate materials and geometry, and ensuring optimal fluid velocities and pressure drops within design limits.
This document provides an overview of the functional design of two types of heat exchangers: shell and tube heat exchangers and plate heat exchangers. It discusses the key components, design considerations, and step-by-step design procedures for shell and tube heat exchangers. These include determining the heat transfer area, number of tubes, tube dimensions, baffle design, and accounting for pressure drops and fouling factors. It also introduces plate heat exchangers and discusses their mechanical characteristics and design methods at a high level.
The document summarizes the design and analysis of an air-cooled heat exchanger for a 3-phase induction motor. It outlines specifications for the heat exchanger including air flow rates, temperatures, and heat exchange capacity. It then describes an 8-step process for the design including selecting materials, configuring piping, calculating heat transfer coefficients, and evaluating effectiveness. The scope of the project is defined as developing a prototype while considering losses, fan calculations, cost analysis, and testing iterations through graphical plotting.
The document discusses the thermal design of cooling and dehumidifying coils. It describes:
- The types of cooling coils, including direct-expansion and chilled water coils.
- Methods for numerically calculating the thermal design using a discrete "row-by-row" technique to locally trace temperatures.
- Governing equations for the air-side and coolant-side energy balances that are applied to discretized segments of the coil to compute the required surface area.
This document provides information about shell and tube heat exchangers, including basic calculations. It defines key concepts such as specific heat, temperature scales, pressure units and energy conversions. It also outlines the overall design process for a shell and tube heat exchanger, describing how to calculate the required heat transfer rate and surface area based on parameters like the overall heat transfer coefficient and log mean temperature difference.
The document discusses the steps for designing a heat exchanger. It begins by introducing the basic heat exchanger equation that relates heat transfer rate, surface area, and temperature difference. It then outlines 14 steps for heat exchanger design, which include: 1) assuming tube dimensions and material, 2) fouling factors, 3) tube material properties, 4) determining temperature points, 5) calculating the log mean temperature difference, 6) correction factors, 7) mean temperature difference, 8) heat transfer coefficient, 9) required surface area, 10) number of tubes, 11) tube pitch and bundle diameter, 12) floating head type, 13) shell diameter, and 14) baffle spacing. The goal is to use these steps
iaetsd Heat transfer enhancement of shell and tube heat exchanger using conic...Iaetsd Iaetsd
This document discusses heat transfer enhancement in a shell and tube heat exchanger using a conical tape insert. It provides heat transfer and friction factor data from experiments using the heat exchanger fitted with a helical tape insert. Hot air was passed through the inner tube while cold water flowed in the annulus. The helical insert increased heat transfer rate by up to 165% compared to the plain tube, with some increase in pressure drop. Equations and calculations are provided for determining heat transfer coefficients, pressure drops, and other parameters on both the shell and tube sides of the heat exchanger. Graphs of results are also presented.
This document provides an overview of Kern's method for designing shell-and-tube heat exchangers. It begins with objectives and an introduction to Kern's method. It then outlines the design procedure algorithm and provides an example application. The example involves designing an exchanger to sub-cool methanol condensate using brackish water as the coolant. The document walks through each step of the Kern's method design process for this example, including calculating properties, determining duties, selecting tube/shell parameters, and estimating heat transfer coefficients.
Heat exchangers transfer thermal energy between two or more fluids at different temperatures. They are classified based on their transfer process, geometry, heat transfer mechanism, and flow arrangement. Shell-and-tube heat exchangers consist of a set of tubes in a shell container and are the most important type, used across many industries. Their design involves calculating the heat transfer rate, selecting appropriate materials and geometry, and ensuring optimal fluid velocities and pressure drops within design limits.
This document provides an overview of the functional design of two types of heat exchangers: shell and tube heat exchangers and plate heat exchangers. It discusses the key components, design considerations, and step-by-step design procedures for shell and tube heat exchangers. These include determining the heat transfer area, number of tubes, tube dimensions, baffle design, and accounting for pressure drops and fouling factors. It also introduces plate heat exchangers and discusses their mechanical characteristics and design methods at a high level.
The document summarizes the design and analysis of an air-cooled heat exchanger for a 3-phase induction motor. It outlines specifications for the heat exchanger including air flow rates, temperatures, and heat exchange capacity. It then describes an 8-step process for the design including selecting materials, configuring piping, calculating heat transfer coefficients, and evaluating effectiveness. The scope of the project is defined as developing a prototype while considering losses, fan calculations, cost analysis, and testing iterations through graphical plotting.
The document discusses the thermal design of cooling and dehumidifying coils. It describes:
- The types of cooling coils, including direct-expansion and chilled water coils.
- Methods for numerically calculating the thermal design using a discrete "row-by-row" technique to locally trace temperatures.
- Governing equations for the air-side and coolant-side energy balances that are applied to discretized segments of the coil to compute the required surface area.
This document provides information about shell and tube heat exchangers, including basic calculations. It defines key concepts such as specific heat, temperature scales, pressure units and energy conversions. It also outlines the overall design process for a shell and tube heat exchanger, describing how to calculate the required heat transfer rate and surface area based on parameters like the overall heat transfer coefficient and log mean temperature difference.
The document discusses the steps for designing a heat exchanger. It begins by introducing the basic heat exchanger equation that relates heat transfer rate, surface area, and temperature difference. It then outlines 14 steps for heat exchanger design, which include: 1) assuming tube dimensions and material, 2) fouling factors, 3) tube material properties, 4) determining temperature points, 5) calculating the log mean temperature difference, 6) correction factors, 7) mean temperature difference, 8) heat transfer coefficient, 9) required surface area, 10) number of tubes, 11) tube pitch and bundle diameter, 12) floating head type, 13) shell diameter, and 14) baffle spacing. The goal is to use these steps
Shell & tube heat exchanger single fluid flow heat transferVikram Sharma
This article was produced to highlight the fundamentals of single-phase heat exchanger rating using Kern's method. The content is strictly academic with no reference to industrial best practices.
Design method for shell tube heat exchangerKarnav Rana
Design method for shell tube heat exchanger
Selection of Cooling Medium or Heating Medium
shell tube heat exchanger
Heating mediums
Cooling mediums
Energy Balance and Heat Transfer Calculations
Mean Temperature Difference
Estimation of Overall Heat Transfer Coefficient
Finding Shell Diameter
Comparison of Shell and Tube Heat Exchanger using Theoretical Methods, HTRI, ...IJERA Editor
This document compares the design of a shell and tube heat exchanger with baffles using four different methods: 1) Kern's theoretical method, 2) ASPEN simulation software, 3) HTRI simulation software, and 4) SOLIDWORKS simulation software. The same input parameters were used to design a shell and tube heat exchanger with single segmental baffles in each method. The results from all four methods for shell side pressure drop and heat transfer coefficient were found to be in close agreement. The theoretical Kern method design results closely matched the simulation software results, showing proven theoretical methods can accurately model shell and tube heat exchanger performance.
This document provides an overview of heat transfer principles and design considerations for heat exchangers, condensers, reboilers, and air coolers. It discusses the three modes of heat transfer (conduction, convection, and radiation) and covers topics like heat transfer coefficients, temperature profiles, pressure drop calculations, and mechanical design standards. The document also describes design procedures for shell and tube heat exchangers using methods like Kern's method and Bell's method to determine heat transfer coefficients and pressure drops.
Fired heaters and its auxiliaries are an essential component in the Chemical Process Industries (CPI). Fired heaters are primarily used to heat hydrocarbons. They are one of the major consumers of energy and hence, it is indispensable for such systems to have efficient operation.
Furnace Improvements Services has a specialist CFD team for modelling fired heater systems. We have developed best practices for each of the above cases and have successfully implemented various recommendations from CFD simulations.
ECONOMIC INSULATION FOR INDUSTRIAL PIPINGVijay Sarathy
Thermal Insulation for Industrial Piping is a common method to reduce energy costs in production facilities while meeting process requirements. Insulation represents a capital expenditure & follows the law of diminishing returns. Hence the thermal effectiveness of insulation needs to be justified by an economic limit, beyond which insulation ceases to effectuate energy recovery. To determine the effectiveness of an applied insulation, the insulation cost is compared with the associated energy losses & by choosing the thickness that gives the lowest total cost, termed as ‘Economic Thickness’.
The following tutorial provides guidance to estimate the economic thickness for natural gas piping in winter conditions as an example case study.
This document discusses basic heat transfer concepts and their relationship to heating coil selection. It covers topics like heat transfer occurring due to temperature differences, the factors that affect heat transfer rate, common coil materials and their thermal conductivity. It also describes different types of coils, coil configurations, construction details and model number selection criteria.
Piping systems associated with production, transporting oil & gas, water/gas injection into reservoirs, experience wear & tear with time & operations. There would be metal loss due to erosion, erosion-corrosion and cavitation to name a few. The presence of corrosion defects provides a means for localized fractures to propagate causing pipe ruptures & leakages. This also reduces the pipe/pipeline maximum allowable operating pressure [MAOP].
The following document covers methods by DNV standards to quantitatively estimate the erosion rate for ductile pipes and bends due to the presence of sand. It is to be noted that corrosion can occur in many other scenarios such as pipe dimensioning, flow rate limitations, pipe performance such as pressure drop, vibrations, noise, insulation, hydrate formation and removal, severe slug flow, terrain slugging and also upheaval buckling. However these aspects are not covered in this document.
Based on the erosional rates of pipes and bends, the Maximum Safe Pressure/Revised MAOP is evaluated based on a Level 1 Assessment procedure for the remaining strength of the pipeline. The Level 1 procedures taken up in this tutorial are RSTRENG 085dL method, DNVGL RP F-101 (Part-B) and PETROBRAS’s PB Equation.
Finned-tube Heat Exchanger with Circular, Eliiptical and Rectangular Tubes wi...Hasibul Hasan Shovon
1) The study numerically investigates a finned-tube heat exchanger with circular, elliptical and rectangular tubes using water vapor as the working fluid.
2) Results show that heat exchanger designs with elliptical and rectangular tubes have higher heat transfer coefficients compared to the baseline circular tube design, with some designs also having lower pressure drops.
3) Temperature and pressure contours indicate better heat transfer and lower resistance for some modified designs compared to the baseline, especially at higher inlet velocities.
Optimization of Air Preheater for compactness of shell by evaluating performa...Nemish Kanwar
Designing of an Air Preheater with increased performance from an existing design through alteration in baffle placement. Analysis of 4 Baffle designs for segmented Baffle case was done using Ansys Fluent. The net heat recovery rate was computed by subtracting pump work from heat recovered. Based on the result, Air Preheater design was recommended.
Optimization of a Shell and Tube Condenser using Numerical MethodIJERA Editor
The purpose of this study was to investigate the effect of installation of the tube external surfaces, their parameter and variable in a shell-and-tube condenser. Variation of heat transfer coefficient with each variable of shell and tube condenser was measured each test. The optimization tube outside diameter size was analyzed and use extended surface area attached tube with tube material and tube layout and arrangement (Number of tube a triangular or hexagonal arrangement) on shell-and tube condenser. The computer programming was used to get faster output in less time. Results suggest that mean heat transfer coefficient in variable condition were mainly at velocity is fixed. And also average additional surfaces and tube layout and the arrangement comparison with the quantity of the heat transfer.
This document describes the design of a ribbed heat exchanger. It begins with an abstract that outlines heat exchangers, their uses, and the goal of designing for heat transfer rates. It then presents the problem statement of designing a ribbed heat exchanger with high effectiveness. The document calculates the required length of pipe through assumptions about temperatures and flows, using the log mean temperature difference method. The calculations find a required surface area of 3.76 square feet, which corresponds to a pipe length of 65 centimeters. In conclusion, the length of pipe for the designed heat exchanger is 65 cm based on the provided calculations.
BOIL OFF GAS ANALYSIS OF LIQUEFIED NATURAL GAS (LNG) AT RECEIVING TERMINALSVijay Sarathy
This document provides background information on boil off gas (BOG) from liquefied natural gas (LNG) storage tanks. It discusses how LNG is transported and stored, and how BOG is generated as heat causes some LNG to vaporize. The key points are:
- LNG is transported internationally on specially designed ships and stored in insulated tanks at receiving terminals. Heat ingress causes some LNG to vaporize, generating BOG.
- BOG management is important for tank pressure control and to prevent weathering of the LNG composition. The boil off rate needs to be precisely determined.
- The document provides design details of a sample single containment LNG tank, and makes assumptions
Mesh Independence Analysis for a test heater shows that results change with further refinement of mesh. A trade-off has to be made between the accuracy of simulation and the computation time. This analysis comes in handy in such situations which helps in optimising time and effort.
The document describes conducting experiments to determine the performance characteristics of various hydraulic machines, including a Venturi meter, centrifugal pump, reciprocating pump, gear oil pump, and Pelton turbine. Key steps involve taking readings like discharge rate, head, power, and efficiency while varying operating parameters. Performance is evaluated based on graphs of discharge versus head, power and efficiency to find the best operating conditions and maximum efficiencies of the machines.
The document contains formulas and information related to HVAC systems. It defines key terms like tons of refrigeration, horsepower, voltage, amperage, resistance, watts, capacitance, gas laws, and geometric formulas. It also includes formulas for calculating areas, volumes, BTUs, airflow, efficiency, and sizing components like ducts, grilles, burners, and nozzles.
This document describes a heat exchanger design project. It provides theory on heat exchanger design including heat transfer rate calculations. It then details the CFD simulation process used to model and analyze different heat exchanger designs. This included an initial 2D model, mesh refinement studies to determine optimal mesh size, and modeling variations in pipe spacing, flow direction, and a 3D design. Results were analyzed using temperature, turbulence, and velocity contours to evaluate design performance.
Techniques of heat transfer enhancement and their application chapter 6ssusercf6d0e
This document discusses different types of externally finned tubes used in heat exchangers. It describes plain plate fins attached to round tubes, as well as enhanced fin geometries like wavy and interrupted fins. The effects of fin spacing and geometry on heat transfer and friction are examined. Reynolds number is defined based on both tube diameter and hydraulic diameter, and it is noted that tube diameter may be a better characteristic length for finned tubes. Friction factor definitions are also discussed.
Exploring LPG Cylinders for Medical Oxygen - A Preliminary StudyVijay Sarathy
This document studies using LPG cylinders to supply medical oxygen in emergencies. It analyzes how long oxygen can be supplied from an LPG cylinder at flow rates of 0.5 and 2 liters per minute. The study finds the cylinder can supply oxygen at 0.5 liters/min for about 3 hours and at 2 liters/min for about 45 minutes before the pressure drops to 1 atmosphere. Governing equations for transient blowdown of the cylinder are derived in the appendices.
This document discusses heat exchangers and provides details on shell-and-tube heat exchangers. It describes the basic components and design of shell-and-tube heat exchangers, including tubes, tube sheets, baffles, and shells. Equations for heat transfer and thermal analysis of shell-and-tube exchangers are presented. An example problem demonstrates the design calculations to determine the required heat exchanger area and fluid flow rates.
Analisis rewetting time dan distribusi temperatur plat english rev04moh rohmatulloh
This document analyzes the effect of gap size on rewetting time and temperature distributions during the cooling process in a vertical rectangular narrow channel. The experiment used two vertical plates with an initial temperature of around 600°C. Cooling water with a flow rate of 0.09 L/s and saturated temperature was flowed through gaps of 1 mm, 2 mm, and 3 mm. The results showed that smaller gap sizes led to longer rewetting times, as smaller gaps increase vapor pressure and decrease the cooling water mass flow rate. Temperature distributions were similar initially for all gap sizes but decreased more slowly over time for smaller gaps.
The document summarizes an experiment to determine heat transfer coefficients in a cross-flow plate heat exchanger under both continuous and batch operations. For continuous operation, the heat transfer rate and coefficient increased with increasing cold water flow rate. The heat transfer coefficient was highest at around 5 gallons per minute. For batch operation, the heat transfer coefficient was determined to be 7490 ± 300 W/m2K using linear regression modeling, which was higher than continuous operation. Heat losses to the environment likely contributed to the lower coefficient in continuous operation compared to batch.
Shell & tube heat exchanger single fluid flow heat transferVikram Sharma
This article was produced to highlight the fundamentals of single-phase heat exchanger rating using Kern's method. The content is strictly academic with no reference to industrial best practices.
Design method for shell tube heat exchangerKarnav Rana
Design method for shell tube heat exchanger
Selection of Cooling Medium or Heating Medium
shell tube heat exchanger
Heating mediums
Cooling mediums
Energy Balance and Heat Transfer Calculations
Mean Temperature Difference
Estimation of Overall Heat Transfer Coefficient
Finding Shell Diameter
Comparison of Shell and Tube Heat Exchanger using Theoretical Methods, HTRI, ...IJERA Editor
This document compares the design of a shell and tube heat exchanger with baffles using four different methods: 1) Kern's theoretical method, 2) ASPEN simulation software, 3) HTRI simulation software, and 4) SOLIDWORKS simulation software. The same input parameters were used to design a shell and tube heat exchanger with single segmental baffles in each method. The results from all four methods for shell side pressure drop and heat transfer coefficient were found to be in close agreement. The theoretical Kern method design results closely matched the simulation software results, showing proven theoretical methods can accurately model shell and tube heat exchanger performance.
This document provides an overview of heat transfer principles and design considerations for heat exchangers, condensers, reboilers, and air coolers. It discusses the three modes of heat transfer (conduction, convection, and radiation) and covers topics like heat transfer coefficients, temperature profiles, pressure drop calculations, and mechanical design standards. The document also describes design procedures for shell and tube heat exchangers using methods like Kern's method and Bell's method to determine heat transfer coefficients and pressure drops.
Fired heaters and its auxiliaries are an essential component in the Chemical Process Industries (CPI). Fired heaters are primarily used to heat hydrocarbons. They are one of the major consumers of energy and hence, it is indispensable for such systems to have efficient operation.
Furnace Improvements Services has a specialist CFD team for modelling fired heater systems. We have developed best practices for each of the above cases and have successfully implemented various recommendations from CFD simulations.
ECONOMIC INSULATION FOR INDUSTRIAL PIPINGVijay Sarathy
Thermal Insulation for Industrial Piping is a common method to reduce energy costs in production facilities while meeting process requirements. Insulation represents a capital expenditure & follows the law of diminishing returns. Hence the thermal effectiveness of insulation needs to be justified by an economic limit, beyond which insulation ceases to effectuate energy recovery. To determine the effectiveness of an applied insulation, the insulation cost is compared with the associated energy losses & by choosing the thickness that gives the lowest total cost, termed as ‘Economic Thickness’.
The following tutorial provides guidance to estimate the economic thickness for natural gas piping in winter conditions as an example case study.
This document discusses basic heat transfer concepts and their relationship to heating coil selection. It covers topics like heat transfer occurring due to temperature differences, the factors that affect heat transfer rate, common coil materials and their thermal conductivity. It also describes different types of coils, coil configurations, construction details and model number selection criteria.
Piping systems associated with production, transporting oil & gas, water/gas injection into reservoirs, experience wear & tear with time & operations. There would be metal loss due to erosion, erosion-corrosion and cavitation to name a few. The presence of corrosion defects provides a means for localized fractures to propagate causing pipe ruptures & leakages. This also reduces the pipe/pipeline maximum allowable operating pressure [MAOP].
The following document covers methods by DNV standards to quantitatively estimate the erosion rate for ductile pipes and bends due to the presence of sand. It is to be noted that corrosion can occur in many other scenarios such as pipe dimensioning, flow rate limitations, pipe performance such as pressure drop, vibrations, noise, insulation, hydrate formation and removal, severe slug flow, terrain slugging and also upheaval buckling. However these aspects are not covered in this document.
Based on the erosional rates of pipes and bends, the Maximum Safe Pressure/Revised MAOP is evaluated based on a Level 1 Assessment procedure for the remaining strength of the pipeline. The Level 1 procedures taken up in this tutorial are RSTRENG 085dL method, DNVGL RP F-101 (Part-B) and PETROBRAS’s PB Equation.
Finned-tube Heat Exchanger with Circular, Eliiptical and Rectangular Tubes wi...Hasibul Hasan Shovon
1) The study numerically investigates a finned-tube heat exchanger with circular, elliptical and rectangular tubes using water vapor as the working fluid.
2) Results show that heat exchanger designs with elliptical and rectangular tubes have higher heat transfer coefficients compared to the baseline circular tube design, with some designs also having lower pressure drops.
3) Temperature and pressure contours indicate better heat transfer and lower resistance for some modified designs compared to the baseline, especially at higher inlet velocities.
Optimization of Air Preheater for compactness of shell by evaluating performa...Nemish Kanwar
Designing of an Air Preheater with increased performance from an existing design through alteration in baffle placement. Analysis of 4 Baffle designs for segmented Baffle case was done using Ansys Fluent. The net heat recovery rate was computed by subtracting pump work from heat recovered. Based on the result, Air Preheater design was recommended.
Optimization of a Shell and Tube Condenser using Numerical MethodIJERA Editor
The purpose of this study was to investigate the effect of installation of the tube external surfaces, their parameter and variable in a shell-and-tube condenser. Variation of heat transfer coefficient with each variable of shell and tube condenser was measured each test. The optimization tube outside diameter size was analyzed and use extended surface area attached tube with tube material and tube layout and arrangement (Number of tube a triangular or hexagonal arrangement) on shell-and tube condenser. The computer programming was used to get faster output in less time. Results suggest that mean heat transfer coefficient in variable condition were mainly at velocity is fixed. And also average additional surfaces and tube layout and the arrangement comparison with the quantity of the heat transfer.
This document describes the design of a ribbed heat exchanger. It begins with an abstract that outlines heat exchangers, their uses, and the goal of designing for heat transfer rates. It then presents the problem statement of designing a ribbed heat exchanger with high effectiveness. The document calculates the required length of pipe through assumptions about temperatures and flows, using the log mean temperature difference method. The calculations find a required surface area of 3.76 square feet, which corresponds to a pipe length of 65 centimeters. In conclusion, the length of pipe for the designed heat exchanger is 65 cm based on the provided calculations.
BOIL OFF GAS ANALYSIS OF LIQUEFIED NATURAL GAS (LNG) AT RECEIVING TERMINALSVijay Sarathy
This document provides background information on boil off gas (BOG) from liquefied natural gas (LNG) storage tanks. It discusses how LNG is transported and stored, and how BOG is generated as heat causes some LNG to vaporize. The key points are:
- LNG is transported internationally on specially designed ships and stored in insulated tanks at receiving terminals. Heat ingress causes some LNG to vaporize, generating BOG.
- BOG management is important for tank pressure control and to prevent weathering of the LNG composition. The boil off rate needs to be precisely determined.
- The document provides design details of a sample single containment LNG tank, and makes assumptions
Mesh Independence Analysis for a test heater shows that results change with further refinement of mesh. A trade-off has to be made between the accuracy of simulation and the computation time. This analysis comes in handy in such situations which helps in optimising time and effort.
The document describes conducting experiments to determine the performance characteristics of various hydraulic machines, including a Venturi meter, centrifugal pump, reciprocating pump, gear oil pump, and Pelton turbine. Key steps involve taking readings like discharge rate, head, power, and efficiency while varying operating parameters. Performance is evaluated based on graphs of discharge versus head, power and efficiency to find the best operating conditions and maximum efficiencies of the machines.
The document contains formulas and information related to HVAC systems. It defines key terms like tons of refrigeration, horsepower, voltage, amperage, resistance, watts, capacitance, gas laws, and geometric formulas. It also includes formulas for calculating areas, volumes, BTUs, airflow, efficiency, and sizing components like ducts, grilles, burners, and nozzles.
This document describes a heat exchanger design project. It provides theory on heat exchanger design including heat transfer rate calculations. It then details the CFD simulation process used to model and analyze different heat exchanger designs. This included an initial 2D model, mesh refinement studies to determine optimal mesh size, and modeling variations in pipe spacing, flow direction, and a 3D design. Results were analyzed using temperature, turbulence, and velocity contours to evaluate design performance.
Techniques of heat transfer enhancement and their application chapter 6ssusercf6d0e
This document discusses different types of externally finned tubes used in heat exchangers. It describes plain plate fins attached to round tubes, as well as enhanced fin geometries like wavy and interrupted fins. The effects of fin spacing and geometry on heat transfer and friction are examined. Reynolds number is defined based on both tube diameter and hydraulic diameter, and it is noted that tube diameter may be a better characteristic length for finned tubes. Friction factor definitions are also discussed.
Exploring LPG Cylinders for Medical Oxygen - A Preliminary StudyVijay Sarathy
This document studies using LPG cylinders to supply medical oxygen in emergencies. It analyzes how long oxygen can be supplied from an LPG cylinder at flow rates of 0.5 and 2 liters per minute. The study finds the cylinder can supply oxygen at 0.5 liters/min for about 3 hours and at 2 liters/min for about 45 minutes before the pressure drops to 1 atmosphere. Governing equations for transient blowdown of the cylinder are derived in the appendices.
This document discusses heat exchangers and provides details on shell-and-tube heat exchangers. It describes the basic components and design of shell-and-tube heat exchangers, including tubes, tube sheets, baffles, and shells. Equations for heat transfer and thermal analysis of shell-and-tube exchangers are presented. An example problem demonstrates the design calculations to determine the required heat exchanger area and fluid flow rates.
Analisis rewetting time dan distribusi temperatur plat english rev04moh rohmatulloh
This document analyzes the effect of gap size on rewetting time and temperature distributions during the cooling process in a vertical rectangular narrow channel. The experiment used two vertical plates with an initial temperature of around 600°C. Cooling water with a flow rate of 0.09 L/s and saturated temperature was flowed through gaps of 1 mm, 2 mm, and 3 mm. The results showed that smaller gap sizes led to longer rewetting times, as smaller gaps increase vapor pressure and decrease the cooling water mass flow rate. Temperature distributions were similar initially for all gap sizes but decreased more slowly over time for smaller gaps.
The document summarizes an experiment to determine heat transfer coefficients in a cross-flow plate heat exchanger under both continuous and batch operations. For continuous operation, the heat transfer rate and coefficient increased with increasing cold water flow rate. The heat transfer coefficient was highest at around 5 gallons per minute. For batch operation, the heat transfer coefficient was determined to be 7490 ± 300 W/m2K using linear regression modeling, which was higher than continuous operation. Heat losses to the environment likely contributed to the lower coefficient in continuous operation compared to batch.
Analysis of effect gapsize to counter current flow limitation knep bali 2014moh rohmatulloh
Three methods were used to analyze the existence of counter current flow limitation (CCFL) in vertical rectangular narrow channels with varying gap sizes:
1. Comparing the time it took for cooling water to flow through the channel without heating versus with initial heating of the plates to 500°C. Smaller gap sizes resulted in longer times, indicating stronger CCFL effects.
2. Analyzing the vapor and water superficial velocities - CCFL occurs when the vapor velocity is higher than the water velocity. For all gap sizes, the vapor velocity was higher, showing CCFL was present.
3. Examining the rewetting time and critical heat flux (CHF) values. Under the same initial temperature,
Aim:
To determine the heat loss in a double pipe heat exchanger counter-current flow
experiment.
Theory:
A double-pipe heat transfer exchanger consists of one or more pipes placed
concentrically inside another pipe of a larger diameter with appropriate fittings to direct
the flow from one section to the next. One fluid flows through the inner pipe (tube side)
in this experiment (hot water), and the other flows through the annular space (annulus)
(cold water).
The double-pipe heat exchanger is one of the basic kinds of exchangers with a very
flexible configuration. There are two types of counterflow or parallel flow for this type
that are the basis of design and calculation for determining pipe size, length, and
number of bends.
Double pipe heat exchanger counter current: heat is exchanged between two flowing
fluids at a different temperature that flows counter current in the heat exchanger double
pipe.
The efficiency is greater in counter-current than in parallel flow because the two fluids
(water) flow separately in counter-current flow when the high different temperatures
meet heat exchange rapidly due to the difference of temperatures, the hot water
becomes warm then cold as heat exchanges, and the cold water becomes warm the heat
exchange occurs till it reaches steady state. As it is explained in Figure 1.
Heat loss can be found by the equation below:
Q=ΔH=mCpΔT
Where: Q=ΔH is the amount of heat transferred to or from the system (J).
m: mass of the system (Kg)
Cp: constant pressure specific heat capacity of the system (J/g°C)
ΔT: difference in temperature of the system °C.
Experiment: Double pipe heat exchanger
4
Figure 1: concurrent and countercurrent respectively.
Procedure:
Double pipe heat exchanger: as shown in the figure-2:
1. Power switch: No.1
2. Temperature scale to select a temperature to heat the water in the tank [No.2] in
the figure.
3. Water tank a heating coil is used to heat the water [no.3].
4. Power pump to set a flow rate, the water is pumped through the double pipe heat
exchanger. [No.4]
5. A flow rate measurement is found in no.5
6. [No.6-7-8-9-10] The temperature measurements measure temperature
throughout the process.
7. Then the temperature and flow rate are collected in the temperature screen.
Experiment: Double pipe heat exchanger
5
Figure 2: double pipe heat exchanger.
Experiment: Double pipe heat exchanger
6
observation:
1. Turn on the device with the power switch.
2. The flow rate is set as 157 ml/s.
3. Heat water up to [40-50 Celsius] in this experiment: [44.4 Celsius] by the
heating coil in the water tank, set the desired temperature by the temperature
scale in the water tank.
4. Then water is pumped to the pipes by the power pump.
5. Adjust the valves so that the hot water and cold water flow countercurrent.
6. The hot water flows in the inner pipe in the double pipe through the pipe from
the pump to the heat exchanger
7. the cold water flows in the outer pipe counter current from the tank to the pipes
the valv
Heat Transfer Enhancement of Shell and Tube Heat Exchanger Using Conical Tapes.IJERA Editor
This paper provides heat transfer and friction factor data for single -phase flow in a shell and tube heat exchanger fitted with a helical tape insert. In the double concentric tube heat exchanger, hot air was passed through the inner tube while the cold water was flowed through the annulus. The influences of the helical insert on heat transfer rate and friction factor were studied for counter flow, and Nusselt numbers and friction factor obtained were compared with previous data (Dittus 1930, Petukhov 1970, Moody 1944) for axial flows in the plain tube. The flow considered is in a low Reynolds number range between 2300 and 8800. A maximum percentage gain of 165% in heat transfer rate is obtained for using the helical insert in comparison with the plain tube.
1) The document presents an experimental study of heat transfer through a uniformly heated vertical tube air heater.
2) The study investigates the effect of tube length, diameter, and heat flux on heat transfer and buoyancy induced airflow.
3) It was found that the heat transfer coefficient increases with increasing heat flux but decreases with increasing tube diameter and length, while air outlet temperature increases with tube length and heat flux but decreases with diameter.
This document discusses the design of a heat exchanger to raise the temperature of air from 25°C to 400°C using combustion gas at 1800°C. It includes the problem statement, assumptions, relevant equations, and calculations to determine the required tube length. The key steps are: (1) determining mass flow rates and properties of air and combustion gas, (2) calculating heat transfer coefficients on the tube and shell sides, and (3) using effectiveness-NTU method to calculate the required tube length based on the heat transfer rates and coefficients. The goal is to evaluate if the heat exchanger dimensions provide high efficiency and could be applied to real systems.
The document describes heat exchangers and experiments conducted using a shell and tube heat exchanger and a plate heat exchanger. It discusses three types of fluid flow - parallel, counter, and cross-flow. Experiments were conducted with both exchangers under parallel and counter-flow configurations. Temperature and flow rate data was collected and used to calculate effectiveness, heat transfer coefficients, and log mean temperature difference. The results showed that the counter-flow configuration had higher effectiveness compared to parallel flow in both exchangers.
FINAL_201 Thursday A-3 Convective and Radiant Heat TransferKaylene Kowalski
This document describes an experiment on heat transfer through various modes. Thermocouples measured the temperature of a heated cylinder surface and surrounding air temperature. The experiment determined heat loss coefficients and amounts due to radiation, natural convection, and forced convection by varying voltage, temperature, and air velocity. Total heat loss was calculated from individual heat losses to understand heat transfer under different conditions.
Heat transfer laboratory HEAT EXCHANGERSoday hatem
1. The document discusses heat exchangers and describes an experiment using a shell and tube heat exchanger. The objectives are to evaluate heat transfer coefficients, LMTD, heat transfer, and heat loss. Water is used as the hot and cold fluids flowing in counter-current configuration.
2. Key aspects covered include types of heat exchangers, theory behind heat transfer calculations, experimental procedures, results which did not match theory due to bubbles, and conclusions that objectives were still met despite non-ideal results.
3. The shell and tube heat exchanger uses water, with hot water inside tubes and cold water in the shell space. Heat is transferred between the streams in counter-current flow. Calculations
FEEMSSD presentation on shell and tube heat exchanger75 .pptxAdarshPandey510683
The document describes the design of a shell and tube heat exchanger. It discusses the components of a shell and tube heat exchanger including the shell, tubes, tube bundle, tubesheet, expansion joint, flanges, gaskets, nozzles, and baffles. It also outlines the objectives of designing a shell and tube heat exchanger for an industry application. The thermal design process involves selecting fluids for the tube and shell sides based on properties, calculating the heat transfer area, tube dimensions, and other parameters. The results of the design case study showed that using recommended design ranges from literature led to an optimal design that met design specifications.
This document describes an experiment on heat conduction using different specimen materials and shapes. Temperature data was collected as specimens cooled in air after being heated to an initial temperature in a water bath. The results were used to calculate dimensionless temperature, Fourier number, and Biot number to determine if the lumped capacitance method could be applied. For a stainless steel sphere specimen, the method yielded a heat transfer coefficient of 32.58 W/m2K, consistent with expected values. The experiment allowed students to analyze unsteady state heat transfer and compare heat transfer coefficients for different materials.
This document analyzes critical heat flux (CHF) in vertical rectangular narrow channels. It summarizes several previous studies that experimentally analyzed CHF in narrow channels using different fluids, channel dimensions, and heating conditions. The document then describes the author's own experiment on CHF using a vertical stainless steel plate with a 1 mm gap. Results showed the highest CHF occurred at the middle of the plate and CHF decreased towards the upper and lower parts. CHF values were compared to several existing correlations, with some correlations showing better agreement with results from different plate positions. The study contributes to understanding CHF in narrow channels.
Experimental Study and Investigation of Helical Pipe Heat Exchanger with Vary...IRJET Journal
The document describes an experimental study of a helical pipe heat exchanger with varying pitch. The study investigated how changing the pitch of the helical coil affected the heat exchanger's effectiveness. An experimental setup was designed and built with a helical copper coil inside a vessel to simulate the shell side. Experiments were conducted by varying the hot and cold water flow rates through the coil and shell, and effectiveness was calculated for different pitch values. Results showed that effectiveness decreased with increasing flow rates but remained over 30% even when flow rates doubled.
This document summarizes an experiment using a plate heat exchanger to determine the overall heat transfer coefficient under continuous and batch operating conditions. Temperature measurements and heat transfer calculations were used to find the overall heat transfer at different flow rates. For continuous operation, heat transfer increased with increasing flow rate, supporting published equations. For batch operation, heat transfer was lower than continuous due to the cold inlet temperature continuously increasing. The relationship between Nusselt and Reynolds numbers followed general patterns but constants did not match literature due to insufficient data. Results confirmed continuous operation provides better heat transfer than batch operation.
AN EXPERIMENTAL STUDY OF EXERGY IN A CORRUGATED PLATE HEAT EXCHANGERIAEME Publication
In the present work an attempt has been made to investigate the performance of a 3 channel 1-1 pass, corrugated plate heat exchanger. The plates had sinusoidal wavy surfaces with corrugation angle of 450. Hot water at different inlet temperature ranging from 400C to 600C was made to flow in the central channel to get cooled by water in the outer channels.
Aim of the experiment
“The aim of this experiment is to determine the amount of heat loss from hot water by
parallel flow current in the pipes of the heat exchanger.”
Double Pipe Heat Exchanger. 3
Chemical Engineering Department.
Stage III
Introduction to double pipe heat exchangers
A double pipe heat exchanger, also known as a hairpin heat exchanger, is a type of heat
exchanger used to transfer heat between two fluids. It consists of two concentric pipes,
one inside the other, forming a “U” or “hairpin” shape. One fluid flows through the inner
pipe, while the other flows through the annular space between the inner and outer pipes.
This design allows for efficient heat transfer between the two fluids, making it suitable for
various applications, such as cooling or heating processes in industrial systems.
Types of flows in double pipe heat exchangers
In a double pipe heat exchanger, there are two primary flow arrangements, each with its
variations, however, we’re are going to be focusing on two simple arrangements only, as
they would suffice to comprehend the basic ideas behind double pipe heat exchangers.
One flow arrangement is called “parallel flow” and the other is called “counter flow”.
The latter will be explained in our next experiment.
Parallel flow or uni-flow: in this type of flow, both the hot and cold fluids flow in the
same direction, entering one end of the inner pipe and exiting the other end. This
arrangement is simple but generally less efficient for heat transfer because the
temperature difference between the two fluids decreases along the length of the
exchanger.
Figure 1: simple parallel flow diagram.
By “Research Gate”
Double Pipe Heat Exchanger. 4
Chemical Engineering Department.
Stage III
However, when there’s a significant temperature difference between the two fluids at the
inlet, parallel flow heat exchangers can be more efficient for heat transfer. Both
arrangements have advantages and disadvantages and are used depending on the
system requirements.
Theoretical calculation for heat transfer in double pipe heat
exchangers
Heat Transfer: Heat transfer is the process of the exchange of thermal energy between
two objects or systems that are at different temperatures, and the heat energy always
flows from the high temperature object or system to the low ones because the entropy of
an isolated system can never decrease.
There are several ways to calculate the amount of heat added or lost by an object or a
system. However, in this experiment a relatively simple equation can be used to
determine the amount of heat lost from the hot water, which is equal to the amount of
heat added to the cold water.
When pressure is held constant throughout the process, the amount of heat transfer will
be equal to the change in enthalpy of the system and therefore can be calculated using
constant pressure enthalpy change equation.
Q=ΔH=mCpΔT
Where:
Q=ΔH is the amount of heat transferred to or from the system (J).
m: mass of the system (Kg)
Cp:
The document summarizes the fabrication and testing of a heat exchanger test rig. Key points:
- The test rig was designed and built to study a counter-flow tube heat exchanger using aluminum sheets and tubes.
- Finite element analysis was performed on the rig design to analyze stresses. Water was heated to 40°C and pumped through one side while tap water entered the other side.
- Effectiveness-NTU method was used to calculate theoretical outlet temperatures which were compared to experimental readings to determine error percentages.
SUMMARYThis report represents the outcome of heat exchang.docxpicklesvalery
SUMMARY:
This report represents the outcome of heat exchange via 4 tubes that are fitted within the shell with four thermocouples to determine the temperature for every pass, two passes for the hot water (in/out) and two for the cold water (in/out). The experiment was commencing according to the amount of hot and cold water that was supplied to the inputs of the heat exchange. The supply was managed by the use of taps that would restrain or allow the gush of water. The temperature for the inputs was constant in the most of the 5 runs while the outputs had been changed due to heat exchange occurring within the shell. Hot water had lost temperature while cold water had gained temperature.
An experiment was set up to resolve the energy losses that affect the hot and cold water, by using thermodynamic laws. During the experiment the water gush rates were measured carefully and the data had been collected and entered to allow the calculations of the energy losses that came out. Finally, it was discovered the heat had been exchanged from the hot into the cold to maintain the temperature inside the shell.
Contents:
SUMMARY:i
1.0INTRODUCTION:1
2.0AIM:1
3.0EXPERIMENTAL METHOD:1
4.0EXPERIMENTAL DATA:2
5.0DATA ANALYSIS:2
6.0DISCUSSION:4
7.0CONCLUSION4
ii
INTRODUCTION:
The exchanger consists of a number of tubes that sit inside a shell that allows cold water to flow through them. Hot water flow through the bordering shell and the two fluids exchange heat. Heat exchanger can come in various forms and as such can have many different motives. A radiator in a car and a boiler in a steam engine are both heat exchanger with the radiator cooling the engine, and the boiler exchanging raw materials into steam that can be used for power generation. The heat exchanger that has been used in this experiment was a basic shell and tube style as shown in figure 1. A Jenco digital thermometer and Jenco thermocouple switches are used in the heat exchanger set up to allow to calculate the measurements for the experiment. Flow meters fitted on the inlet of hot and cold water taps are used to change volume flow rates.
AIM:
The aim of the report is to evaluate the heat losses that came out for the hot water. The experiment will carry of recording temperatures and flow rates and then calculating other possible factors that may cause heat loss.EXPERIMENTAL METHOD:
1) Be familiar with the different part of the experimental.
2) Turn on the cold and hot water taps.
3) Turn valves for the cold water at an initial flow rate (approximate 15 L/min for cold water) Make sure that all the water passes through the flow meters (turn off one of the valves in each water supply line)
4) Water for couple of minutes before reading the data.
5) Take the temperature reading for the thermocouples 1 to 5 by press the Jenco thermocouple buttons.
6) Repeat steps from 3) to 5) for 5 different flow rate combinations.EXPERIMENTAL DATA:
Room temperature: 15°C
Run/Quantities
(L/min)
(L/min)
in ...
Analysis of Double Pipe Heat Exchanger With Helical FinsIRJET Journal
This document analyzes a double pipe heat exchanger with helical fins through computational fluid dynamics (CFD). It aims to study the flow and temperature fields inside the tubes for different helical fin angles. The geometry of the double pipe heat exchanger is modeled in CATIA V5 and meshed in Hypermesh. CFD simulations are performed in ANSYS Fluent to analyze the flow and temperature distributions for fin angles of 0, 5, 10, 15, 20, and 25 degrees. The results determine that heat transfer rate and overall heat transfer coefficient increase with helical fins compared to a smooth tube, with fins providing additional surface area to enhance heat transfer.
Similar to 101 Tuesday A-2 Small Shell and Tube (20)
Analysis of Double Pipe Heat Exchanger With Helical Fins
101 Tuesday A-2 Small Shell and Tube
1. 1
Small Shell and Tube Heat Exchanger
University of Pittsburgh
ChE 0101 Section 1080
Foundations of Chemical Engineering Laboratory
Authors:
Kaitlin Muzic, Kaylene Kowalski, Kayla LeMaster,
Emily Connor, Kelly Schreiber, and Taylor Shaffer
Tuesday A-2
2. 2
Table of Contents
Nomenclature 3
1.0 Introduction and Background 4
2.0 Experimental Methodology 6
2.1 Equipment and Apparatus 6
2.2 Experimental Procedures 7
3.0 Results 8
3.1 Technical Objective 1 Results 8
3.2 Technical Objective 2 Results 9
3.3 Graphical Representation of Results 10
4.0 Analysis and Discussion of Results 11
5.0 Summary and Conclusions 14
References 16
Appendix A-1 18
Appendix A-2 19
3. 3
Nomenclature
Variable Description Units
Qh Heat duty of the hot side Watts
Qc Heat duty of the cold side Watts
QL Heat lost to the environment Watts
Cp Specific heat J/(g*°C)
U Overall heat transfer coefficient W/(°C*m2)
A heat transfer surface area of the tubes m2
T Temperature °C
ΔT Change in temperature °C
ΔTlm Log mean temperature difference °C
F Correction factor No units
4. 4
1.0 Introduction and Background
Heat exchangers transfer heat between fluids of two different temperatures. They are
used in chemical and food industries, refrigeration systems, car radiators, venting, and much
more. There are two general types of heat exchangers: direct contact and indirect contact [1].
Direct contact heat exchangers, such as cooling towers, are used with two immiscible substances,
and there is no wall separating the two fluids. Mass and heat transfer generally occur at the same
time [1]. In an indirect contact heat exchanger, a wall separates the two fluids, and thermal
energy is exchanged through the heat transfer surface [1]. A shell and tube heat exchanger is an
example of an indirect contact heat exchanger.
There are different geometries, or configurations, of heat exchangers, such as tubular,
plate, and extended surface [1]. A shell and tube heat exchanger has a tubular configuration;
tubes inside run parallel to the axis of the shell, as seen in Figure 1. One fluid flows on the inside
of the tubes (the tube side) while another fluid flows on the outside of the tubes (the shell side).
In general, if a fluid is corrosive or has a high pressure, it is used on the tube side [3]. A
corrosive fluid will damage only the inside of the tubes and not the entire shell, thus saving
money when equipment needs to be replaced. Special alloy coatings can also be put on the inside
of the tubes to help prevent damage [3]. High pressure fluids are used on the tube side because
the tubes have a smaller diameter than the shell [3]. Thus, the tubes have a higher pressure rating
than the shell.
FIGURE 1: Representation of a shell and tube heat exchanger [2]
The main design objectives of a heat exchanger are ease of cleaning, low cost, and
accommodation for thermal expansion [1]. Shell and tube heat exchangers are relatively less
expensive compared to other types of heat exchangers. They are easy to clean because they can
be dismantled. The utilization of a U-shaped tube can give way to essentially unlimited thermal
5. 5
expansion [1]. Shell and tube heat exchangers also have great design flexibility, meaning that the
tube diameter and length, the number of tubes, and the arrangement of tubes can conveniently be
altered for specific applications [1].
Advantages and disadvantages of shell and tube heat exchangers coincide with the
efficiency of the heat transfer. The tubes can undergo vibrations caused by the shell side of the
exchanger which can damage the tubes [4]. This can lead to a short operation time of the heat
exchanger because damaged tubes need to be replaced [4]. To help solve this problem, baffles
are sometimes used [4]. Baffles also direct the shell side flow back and forth over the tube
bundle which initiates a higher heat transfer rate. However, dead zones are created in the corners
between the baffle and the shell [5]. This leads to a decreased efficiency of heat transfer. Fins
can be added to the tubes to increase the heat transfer surface area, thus increasing the amount of
heat transfer. Insulation around the shell is frequently required to help minimize the heat loss to
the environment [5]. This can be in the form of a second wall around the shell or a special
coating painted on the outside of the shell of the heat exchanger.
The amount of heat transfer and the overall heat transfer coefficient can be found by
using known and experimental quantities at steady state. Steady state means that an equilibrium
has been reached and the inlet and outlet temperatures of the shell and tube sides are no longer
changing. Heat transfer can be found by calculating the heat duty for the tube side and for the
shell side. Heat duty is calculated by multiplying the mass flow rate of the liquid, the specific
heat, and the change in temperature. Under ideal conditions, the heat duty of the tube side and
the heat duty of the shell side are equivalent. To account for heat loss to the environment, the
energy balance has to be adjusted. The energy balance becomes
|Qh|= |Qc| + QL, (1)
where Qh is the heat duty of the shell side, Qc is the heat duty of the tube side, and QL is the heat
loss to the environment. Using this equation and the heat duties of the shell and tube sides, the
heat loss to the environment can be calculated. The overall heat transfer coefficient is a measure
of the overall ability to transfer heat. It can be determined using the equation
Qc = U × A × ΔTlm × F, (2)
6. 6
where U is the overall heat transfer coefficient, A is the heat transfer surface area of the tubes,
ΔTlm is the log mean temperature difference, and F is the correction factor. A large overall heat
transfer coefficient corresponds to heat being more easily transferred between two fluids. Heat
loss and the overall heat transfer coefficient can be used to determine the relative efficiency of a
shell and tube heat exchanger.
The flow rate of a fluid can have an effect on the steady state heat transfer, the heat loss
to the environment, and the overall heat transfer coefficient. The following experiment was
conducted to determine this effect by varying the flow rate of the tube (cold) side while keeping
the shell (hot) side flow rate constant and vice versa.
2.0 Experimental Methodology
2.1 Equipment and Apparatus
To collect the data in this experiment, the small shell and tube heat exchanger is set up as
illustrated in Figures 2 and 3.
FIGURE 2: Annotated diagram of entire small shell and tube heat exchanger
7. 7
FIGURE 3: Annotated detailed diagram of small shell and tube heat exchanger
As shown in Figure 3, the cold water flows from the chiller, through the tube side valve
that regulates the flow rate, and into the small shell and tube heat exchanger. When it exits the
heat exchanger it flows back into the chiller to be cooled again. As this is occurring, the hot
water flows from the heater, through the shell side valve that regulates the flow rate, and into the
small shell and tube heat exchanger. The hot water then exits the small shell and tube heat
exchanger, via the shell side flow out, and enters the heater again. When the shell and tube sides
enter the heat exchanger, the hot water passes over the cold water in the tubes, and heat transfer
occurs. The temperatures of the shell and tube flows are recorded in the LabVIEW program as
they enter and exit the small shell and tube heat exchanger. The flow rates are varied and
recorded by using the LabVIEW program to set the percent valve openings. The data recorded is
used to determine the heat transfer and heat loss of the small shell and tube heat exchanger in
each trial run.
2.2 Experimental Procedures
The first technical objective was to determine how the tube side flow rate affects the heat
transfer and heat loss of the small shell and tube heat exchanger. In this objective, the initial shell
side valve opening was set to 50% and was kept constant for the entire objective. The initial
8. 8
tube side valve opening was set to 10% open. The temperatures were then allowed to stabilize,
and once the system reached steady state, the data was recorded. The tube side valve opening
was then increased to 30% open, and the system was allowed to come to steady state again. The
tube side valve opening was adjusted to 60% open, and the system was once again allowed to
reach steady state. In the last trial, the tube side valve opening was increased to 100% open and
the system was allowed to reach steady state.
The second technical objective was to determine how the shell side flow rate affects the
heat transfer and heat loss of the small shell and tube heat exchanger. In this technical objective,
the initial shell side valve opening was set to 10% open and the initial tube side
valve opening was set to 50% open. The tube side valve opening was kept constant for the entire
second objective. When temperatures were stabilized and the system was at steady state, the data
was recorded. The shell side valve opening was then adjusted to 30% open, and the system was
allowed to stabilize again. The shell side valve opening was then increased to 50% open, and the
system was allowed to come to steady state. Finally, the shell side valve opening was increased
to 70% open, and the system came to steady state again. As in the last objective, every time the
system reached steady state, the data was recorded.
3.0 Results
3.1 Technical Objective 1 Results
The tube side was varied while the shell side remained at 50% open constantly.
Table 1. Heat Duty Results for Technical Objective 1
Tube Side Open 10% 30% 60% 100%
Tube Side Flow Rate (L/min) 1.27 2.86 4.16 4.78
Shell Side Flow Rate (L/min) 3.83 3.85 3.87 3.74
Heat Duty Cold-side Flow
(Watts) 870.34 907.47 905.44 895.23
Heat Duty Hot-Side Flow
(Watts) -1613.27 -1682.47 -1695.22 -1598.08
Heat Loss
(Watts) 742.92 775.01 789.78 702.85
9. 9
The flow rate of the tube side was fairly inconsistent (yet always increased) as changes
were made to adjust the tube side flow while the corresponding shell side flow rates were very
consistent. With the exception of when the tube side is 10% open, the heat duty of the cold-side
flow decreased overall. The heat loss increased as the tube side flow rate increased until the final
adjustment was made to the system, resulting in a drastic drop in heat loss relatively.
Table 2. Heat Transfer Coefficient for Technical Objective 1
Tube Side Open 10% 30% 60% 100%
Tube Side Flow Rate (L/min) 1.27 2.86 4.16 4.78
Shell Side Flow Rate (L/min) 3.83 3.85 3.87 3.74
ΔTlm (°C) 18.80 15.82 14.39 13.47
U (W/°C*m2) 1522.16 1866.95 2020.03 2378.56
The log mean temperature difference (ΔTlm) used to calculate the heat transfer coefficient
inconsistently decreased. The heat transfer coefficient (U) showed a strong positive trend.
3.2 Technical Objective 2 Results
The shell side was varied while the tube side remained at 50% open constantly.
Table 3. Heat Duty Results for Technical Objective 2
Shell Side Open 10% 30% 50% 70%
Shell Side Flow Rate (L/min) 1.24 2.44 3.83 5.22
Tube Side Flow Rate (L/min) 3.92 3.91 3.90 3.90
Heat Duty Hot-side Flow
(Watts) -1374.69 -1646.22 -1655.60 -1733.69
Heat Duty Cold-Side Flow
(Watts) 802.47 897.20 902.78 893.52
Heat Loss
(Watts) 572.21 749.02 752.81 840.17
10. 10
The flow rate of the shell side was fairly inconsistent (yet increased) as changes were
made to adjust the shell side flow while the corresponding tube side flow rates were extremely
consistent. The heat duty of the hot-side flow decreased overall. The heat loss increased as the
shell side flow rate increased.
Table 4. Heat Transfer Coefficient for Technical Objective 2
Shell Side Open 10% 30% 50% 70%
Shell Side Flow Rate (L/min) 1.24 2.44 3.83 5.22
Tube Side Flow Rate (L/min) 3.92 3.91 3.90 3.90
ΔTlm (°C) 17.77 16.00 14.51 13.50
U (W/°C*m2) 1457.95 1810.38 2009.62 2137.88
The log mean temperature difference (ΔTlm) used to calculate the heat transfer coefficient
inconsistently decreased. The heat transfer coefficient (U) showed a strong positive trend.
3.3 Graphical Representation of Results
By varying the tube side (as in technical objective 1), the calculated heat loss data is
confined to a certain range of values. The altered shell side (as in technical objective 2) displayed
an increasing trend upward over a larger range comparatively.
11. 11
FIGURE 4: Heat Loss vs Volumetric Flow Rate
The calculated heat transfer coefficient was fairly similar in both technical objective one
and technical objective two. The final plotted point at which the tube side was 100% open and
the shell side is 70% open differed by about 200 W while the rest of the plotted data of similar
shell and tube side flow rates were within 100 W of each other.
FIGURE 5: Heat Transfer Coefficient vs Volumetric Flow Rate
742.92
775.01
789.78
702.85
572.21
749.02 752.81
840.17
550.00
600.00
650.00
700.00
750.00
800.00
850.00
0.00 1.00 2.00 3.00 4.00 5.00 6.00
HeatLoss(J/sorW)
Volumetric Flow Rate (L/min)
Heat Loss vs Volumetric Flow Rate
Varying Tube Side Varying Shell Side
12. 12
4.0 Analysis and Discussion of Results
In this experiment, the inlet and outlet temperatures of the tube side and the shell side
streams were recorded when the system reached steady state. Then, by taking the density of the
water at a certain temperature and multiplying it by the volumetric flow rate of the fluid, the
mass flow rate was found. The variation of the flow rate of a liquid had a great effect on the
steady state heat exchanger, the heat loss to the environment, and the overall heat transfer
coefficient.
For the first technical objective, the initial tube side valve opening was varied by
percentages ranging from 10% to 100%, while the shell side valve was kept constant at 50%. The
key results from this trial were the decrease in temperatures of both the shell and tube sides, the
heat duty of the tube and shell side flow, and the heat loss to the environment. To begin, the tube
side flow rate was varied and the inlet temperature of the tube side remained around 20.7 ºC,
while the outlet temperature decreased from 30 ºC to 23 ºC. Then, the shell side valve was
observed while the opening remained at a constant 50%. The inlet temperature of the shell side
decreased from 48 ºC to 39 ºC, and the outlet temperature decreased from 41 ºC to 32 ºC. The
decrease in temperature of the tube side in the first objective and of the shell side in the second
objective indicates that heat was transferred from the shell side to the tube side. Heat is always
transferred from the hot liquid to the cold liquid to increase the entropy of the system.
Conceptually, the tube side should have increased in temperature due to the flow of heat.
However, increasing opening of the valve forced the temperature to decrease due to an increase
in the mass flow rate of the tube side. Another key feature is the heat duty calculated for the tube
and shell side flows, which are Qc and Qh, respectively. From equation (3) and equation (4), Qc
and Qh were calculated. The equation for heat duty of the tube side flow is
Qc = mc × Cp × ∆T, (3)
where mc is the mass flow rate of the tube side, Cp is the specific heat of water, and ∆T is the
change in temperature of the tube side flow. At these temperatures, Cp has a value of 4.186 J/g ºC
[6]. The equation for heat duty of the shell side flow is
13. 13
Qh = mh × Cp × ∆T, (4)
where mh is the mass flow rate of the shell side, Cp is the specific heat of water, and ∆T is the
change in temperature of the shell side flow.
For the first technical objective Qc was a large positive number due to Tcold out - Tcold in
being positive. Then, Qh was found to be a large negative number due to Thot out - Thot in being
negative. Finally, the heat lost to the environment, QL, was another key feature that was
calculated from equation (1a).The equation for the heat balance is
|Qh| = |Qc| + QL, (1)
which was rearranged as
QL = |Qh| − |Qc| (1a)
to solve for the heat loss to the environment. From calculation, Qh was a large negative number,
which shows that heat was lost to the surroundings.
For the second technical objective, the initial shell side valve opening was varied by
percentages ranging from 10% to 70%, while the tube side valve was kept constant at 50%. The
key results from this trial were the increase and decrease in temperature for both the inlet and
outlet of the shell and tube side valves, the heat duty of the tube and shell side flow, and the heat
lost to the environment. To begin, the tube side flow rate was varied and the inlet temperature
remained around 20.7℃, while the outlet temperature increased from 23℃ to 24℃. By increasing
the flow rate of the shell side, the tube side temperature increased. Next, the shell side valve was
varied and the inlet temperature decreased from 48 ℃ to 38℃ and the outlet temperature
increased from 32℃ to 33℃. Another key feature is the heat duty calculated for the tube and
shell side flow, which is Qc and Qh respectively. Qc and Qh had been calculated by equation (3)
and equation (4), respectively. From the calculation, Qc for the second technical objective is a
large negative number due to Tcold out - Tcold in being negative. Futhermore, Qh is a large positive
number due to Thot out - Thot in, which is the change in temperatures being positive. Lastly, the heat
14. 14
lost to the environment QL was another key feature calculated from equation (1a). From
calculation, Qh was a large negative number, which shows that the heat loss was gained by the
environment.
From equation (2), the overall heat transfer coefficient was found. The equation for the
overall heat transfer coefficient is
Qc = U × A × ∆Tlm × F, (2)
In the experiment, the overall heat transfer coefficient represents the overall resistance to
heat transfer over the surface area of the tubes, the change in temperature, and the correction
factor. From the data and calculations, when the shell and tube side valves were varied, the heat
transfer coefficient increased. These results are reasonable because the heat transfer coefficient
depends greatly on the amount of heat transferred over a certain area and the change in
temperatures.
After steady state was reached and calculations were completed, the degree of heat loss to
the environment was interpreted. For the first technical objective, QL was negative because the
system lost heat. This shows that Qc and Qh both decrease because, theoretically, energy was
being subtracted from the overall system. In the second objective, QL was also negative because
heat was gained by the surroundings. This shows that both Qc and Qh both decreased, which in
turn means energy again was being added to the environment. In this experiment, there was a
great amount of heat loss because the hot liquid was in the shell side, which is on the outside,
and therefore more heat was lost to the environment.
5.0 Summary and Conclusions
A small shell and tube heat exchanger was used to evaluate the effects of varying either
the shell or tube side flow rate, while keeping the other constant. The purpose of this experiment
was to assess how changing the flow rates affected the steady state heat duty, the overall heat
transfer coefficient of the heat exchanger, and to estimate the heat loss to the environment.
The data collected through the first trial of the experiment involved varying the tube side
and keeping the shell side fixed at 50% open. As the percent opening of the tube side increased,
the temperature of hot fluid going in and out of the exchanger clearly decreased, and the
15. 15
temperatures of the cold fluid going in and out decreased slightly, but not as noticeably. The flow
rate of the hot fluid decreased slightly with each increase of the tube opening, while the flow rate
of the cold fluid increased with each change. This increase in the cold side flow rate was
expected as increasing the valve opening allowed more fluid to flow through. The data collected
from the second trial, with the tube side fixed at 50% open and the shell side changing, showed
similar results in the temperature changes. The flow rates varied oppositely, though, in
comparison to the first trial. The flow rate of the hot fluid increased as the percent valve opening
of the shell increased, and the flow rate of the cold fluid decreased. This was again expected,
since the hot side valve opening was increased each time. It can be determined from both trials
that the shell side temperatures were more affected by the flow rate changes than the tube side.
After all of the data was collected and recorded, some calculations were performed to
better evaluate the results of the experiment. The heat duty was calculated, which is the amount
of heat, or energy, transferred from the hot side to the cold side [7]. For the first technical
objective, the heat duty of the cold side was a large positive number that overall increased with
each percent valve opening increase in the tube side. For the hot side, this value was a negative
number that did not vary significantly. The heat duties of the second technical objective were the
opposite. For the cold side, it was a very negative number that decreased with each change in
flow rate. The heat duty of the hot side was a positive number that had no conclusive trend. The
negative values are the result of cooling, while the positive values indicate that heating occurred
[8]. The overall heat transfer coefficient was also calculated. This number refers to how well heat
is conducted through the fluid [9]. The larger the coefficient, the easier the heat is transferred
from the source to what is being heated [9]. For both technical objectives, the coefficient was a
large number that was positive for the first trial when the tube flow rate was varied, but negative
for the second, when the shell side was varied. Positive means that temperature decreased, and
negative means that temperature increased. Lastly, the heat lost to the environment was
evaluated. For both trials, the heat loss is a very large value. This is because the hot fluid on the
shell side transferred heat to the tube side and the environment.
17. 17
References
[1] A. Pramuanjaroenkij, H. Liu, and S. Kakac, Heat Exchangers: Selection, Rating, and
Thermal Design. Boca Raton, Florida: CRC Press, 2012. pp.8-22.
[2] A.P., “Analysis of a Shell and Tube Heat Exchanger,” oocities.org, 2003. [Online].
Available: http://www.oocities.org/ucoproject/index.htm. [Accessed: Oct. 12, 2015].
[3] Alfa Laval, “Basic Construction of Shell and Tube Heat Exchangers,” Jul 2010. [Online].
Available: http://local.alfalaval.com/en-us/key-technologies/heat-transfer/shell-and-tube-
heat-exchangers/process-
industrial/Documents/TEMA%20basics%20of%20construction%20-%2007.10.pdf.
[Accessed: Oct. 12, 2015].
[4] A. Roberts, E. Giuffrida, J. Palazzolo, K. Minbiole, M. Africa, and R. Kendrick, “Heat
Exchangers,” in Encyclopedia of Chemical Engineering Equipment. University of
Michigan, [online document], 2014. Available: http://encyclopedia.che.engin.umich.edu/
[Accessed: Oct. 10, 2015].
[5] G. Chen, M. Zeng, Q. Chen, and Q. Wang, “Numerical investigation on combined
multiple shell-pass shell-and-tube heat exchanger with continuous helical baffles,”
International Journal of Heat and Mass Transfer, vol. 52, no. 5-6, February, 2009.
[Online serial].
Available: http://www.sciencedirect.com/science/article/pii/S001793100800536X.
[Accessed Oct. 11, 2015].
[6] “Specific Heat Capacity Table,” [Online]. Available:
http://www2.ucdsb.on.ca/tiss/stretton/database/Specific_Heat_Capacity_Table.html.
[Accessed: Oct. 11, 2015].
[7] O. Araromi, A. Oyelaran, and L. Ogunleye. "Design and Development of a Small Heat
Exchanger as Auxiliary Cooling System for Domestic and Industrial Applications,"
International Journal of Engineering Trends and Technology, vol. 5, no. 6, November,
2013. [Online serial]. Available: http://ijettjournal.org/volume-5/number-6/IJETT-
V5N6P157.pdf. [Accessed Oct. 13, 2015].
[8] “Simple Heat Exchanger,” syscad.net, Mar 13, 2014. [Online]. Available:
http://help.syscad.net/index.php/Simple_Heat_Exchanger. [Accessed: Oct. 13, 2015].
[9] “Overall Heat Transfer Coefficient,” tlv.com. [Online]. Available:
http://www.tlv.com/global/TI/steam-theory/overall-heat-transfer-coefficient.html.
[Accessed: Oct. 13, 2015].
[10] J. Welty, C. Wicks, R. Wilson, G. Rorrer, Fundamentals of Momentum, Mass and Heat
Transfer, 2008, pp. 344.
20. 20
Appendix A-2
Example Calculations
The equation for the energy balance to determine heat loss to the environment is
|Qh| = |Qc| + QL. (1)
The equation for the overall heat transfer coefficient is
Qc = U × A × ∆Tlm × F. (2)
The equation for heat duty of the tube side is:
Qc = mc × Cp × ∆T, (3)
where mc is the mass flow rate of the tube side, Cp is the specific heat of water, and ∆T is the
change in temperature of the tube side.
Example Equation 3:
Using data from technical objective 1 when the tube side is 60% open:
𝑄𝑐 = 4.16
𝐿
𝑚𝑖𝑛
×
1 𝑚𝑖𝑛
60 𝑠𝑒𝑐𝑜𝑛𝑑𝑠
×
1000𝑚𝐿
1𝐿
×
. 998207
𝑔
𝑚𝐿 + .997047
𝑔
𝑚𝐿
2
× 4.184
𝐽
𝑔 °𝐶
× (24.00°𝐶 − 20.87°𝐶)
=905.44 W
The equation for heat duty of the hot-side flow is:
Qh = mh × Cp × ∆T, (4)
Where mh is the mass flow rate of the shell side, Cp is the specific heat of water, and ∆T is the
change in temperature of shell side.
21. 21
Example Equation 4:
Using data from technical objective 2 when the shell side is 30% open:
𝑄ℎ = 2.44
𝐿
𝑚𝑖𝑛
×
1 𝑚𝑖𝑛
60 𝑠𝑒𝑐𝑜𝑛𝑑𝑠
×
1000𝑚𝐿
1𝐿
×
.99565
𝑔
𝑚𝐿
+ .990216
𝑔
𝑚𝐿
2
× 4.184
𝐽
𝑔 °𝐶
× (33.61°𝐶 − 43.37°𝐶)
=-1646.22 W
Equation (1) is solved for heat loss as
QL = |Qh| − |Qc|, (5)
where Qh is the heat duty of the hot-side flow and Qc is the heat duty of the cold-side flow.
Example Equation 5:
Using data from technical objective 2 when the shell side is 10% open:
𝑄𝐿 = |−1374.69 𝑊| − |802.47 𝑊| = 572.21 𝑊
Equation (2) is solved for the overall heat transfer coefficient as
U =
Qc
A×∆Tlm×F
, (6)
where Qc the heat duty of the cold-side flow, A is the heat transfer surface area for the tubes
which is 50 in2 that can be converted for dimensional homogeneity to 0.03225812903 m2, F is
.96, and ∆Tlm is expanded upon below [11].
Example Equation 6:
Using data from technical objective 2 when the shell side is 70% open:
22. 22
𝑈 =
893.52 𝑊
50 𝑖𝑛2 ×
(1 𝑚)2
(39.37 𝑖𝑛)2 × 13.50 °𝐶 × .96
=2137.88 W/(°C*m2)
The equation for ∆Tlm (log mean temperature difference) is
∆Tlm =
(T(hot,in)−T(cold,out))−(T(hot,out)−T(cold,in))
ln(
T(hot,in)−T(cold,out)
T(hot,out)−T(cold,in)
)
. (7)
Example Equation 7:
Using data from technical objective 2 when the shell side is 10% open:
∆𝑇𝑙𝑚 =
(48.79 − 23.70)°𝐶 − (32.80 − 20.76)°𝐶
ln (
48.79 − 23.70
32.80 − 20.76
°𝐶
°𝐶
)
=17.77 °C