Heat exchanger training 02. 25. 15

Editor's Notes

1. The Purpose of this course is to review the fundamental basic heat transfer forms and heat transfer equations. The goal is to achieve sizing heat exchangers with minimum available information by using the basic heat transfer equations. What are we going to cover today? We will cover next page
2. Basic Heat Transfer Types of Exchangers Heat Transfer Calculation Formulas Working Problems Lets first review basic heat transfer – next page
3. How many forms of heat transfer? As we learned in school-There are three forms of heat transfer There are Conduction Convection Radiation I am not going to read and explain all this three forms, you may read them late. The purpose I am showing here is to show you how the heat transfer equations are derived.
4. These are the basic fundamental equations
5. When we sized the heat exchanger we need to make sure to check that the U clean is greater than U dirty. Normally the ratio at least is 1.1
6. Now we have refreshed heat transfer basics , here is the picture of shell and tube heat exchanger. It shows you how the heat transfer happens between Hot and cold sides
7. In order to size heat exchanger correctly, we need to know what type of exchanger we are designing, Here are the basic Types of Heat Exchangers
8. In the oil and gas industry we use TEMA Types as a standard design
9. Remember there are many parts attached to heat exchanger. They are all need to take consideration. But not in this course.
10. The basic flow Patten are 1) parallel flow or 2) counter –flow.
11. Here schematic to show how to do log mean temperature difference calculation
12. Obtaining the Ft correction factor can be found in GPSA Book. The graph can be found in GPSA Chapter 9 for shell and tube exchangers. Chapter 10 for Air Coolers,
13. This slide shows you how to read the graph to find Ft correction factor.
14. The other important factor we need to consider for sizing heat exchanger is Approach of a temperature difference. This number you can find in the basis of design document.
15. Now we know all about heat transfers. The real work is to design a heat exchanger. By doing that we need to know which equation we need to use. There are the main heat transfer equations
16. In process calculation we always have to check material balance and heat balance. The above equation is used to check heat balance. Then to find out either process missing variable or utility variable.
17. The equations I am going to show you today are rules of thumb for quick estimation or check purposes.
18. In order to size heat exchanger, what do we need to know? types of the fluids, heat transfer surface area and forms of heat transfer
19. We are often asked what information we require to design a heat exchanger. It depends on the project phases Do we have to have all the required information to design a heat exchanger? Not necessary. That is where we use the quick calculation formulas to design it
20. Information Required to Design a Heat Exchanger 1) Any program or excel spreadsheet requires all the above information
21. In this case PFDs.
22. First We need to know what is the Approach of a Temperature Difference (ATD). This information is from licensor. In the basis of design
23. Check from HYSIS simulation results