Experimental Study of Heat Transfer Analysis in Vertical Rod Bundle of Sub Channel with a Hexagonal on Small Modular Reactor

International
OPEN ACCESS Journal
Of Modern Engineering Research (IJMER)
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 5 | Iss.3| Mar. 2015 | 55|
Experimental Study of Heat Transfer Analysis in Vertical
Rod Bundle of Sub Channel with a Hexagonal on Small
Modular Reactor
Syawaluddin1
, Anwar Ilmar Ramadhan2
, Ery Diniardi3
, Erwin Dermawan4
,
Rismansyah5
1,2,3,5
Department of Mechanical Engineering, University of Muhammadiyah Jakarta, Indonesia
4
Department of Electrical Engineering, University of Muhammadiyah Jakarta, Indonesia
I. INTRODUCTION
Estimates of the temperature distribution in the fuel bundle element are very important in a nuclear
reactor. File cylinder used mostly as a nuclear reactor fuel element configuration, as well as heat exchangers and
passive safety systems [1, 2]. This is certainly a challenge in improving the safety of nuclear reactors at the time
of transfer of heat from the fuel element to the coolant [3, 4]. A fluid heat transfer coefficient is very important;
because of the heat transfer coefficient can determine the fluid used to cool the fuel in a nuclear reactor works
well or not [5, 6].
Phenomena occur in the convection flow into a turbulent or laminar including also affect the heat
transfer coefficient. In NPP (Nuclear Power Plant) for this study used one type of reactor with low power that
SMR (Small Modular Reactor) [7]. Magnitude thermal-hydraulics such as pressure, coolant flow rate and
temperature of the fuel needs to be known, for example through the prediction calculations. For the development
and application of nuclear reactor Small Modular Reactor (SMR) technology was developed for the
implementation of passive cooling systems as well as systems integration to the Generation III + nuclear power
plants. With leading technology and the power generated, it ought to be explored and researched the design and
technology of nuclear reactor Small Modular Reactor CAREM type-25 for one of the new and renewable energy
sources in Indonesia [8].
Experimental studies conducted, done about seven vertical cylinder is heated so as to provide a uniform
constant heat flux with the ratio Pitch/Diameter (P/D) at 1.16 where the cylinder diameter of 3.75 cm and length
of 60 cm. Still in a state of flow conditions develop. Empirical correlations generated as follows [9]:
Forced convection (turbulent flow): Nu = 1.62 Gz 0.27
(1)
867 ≤ Re ≤ 4911
143 ≤ Gz ≤ 3087
ABSTRACT: The ability of the fluid in taking the heat generated by the nuclear reactor fuel is one
important aspect of reactor safety. These capabilities must be kept high enough to maintain integrity of
the fuel cladding as inside retaining radioactive substances. Study characteristics of forced convection in
the fluid water using seven vertical cylinders heated uniformly in the composition ratio of hexagons with
Pitch/Diameter (P/D) at 1.58 in the hexagon-shaped shell model of the reactor core test equipment in
order to obtain the correlation equation displacement convection force. In this study, the heat flux and
velocity of fluid flow greatly affect the temperature of the fluid. The greater the heat flux given the fluid
temperature is getting higher because of the greater heat flux on the cylinder heating the heat absorbed
by the fluid is also getting bigger. Similarly, the velocity of fluid flow, increasing the velocity of the fluid
flow, the smaller the fluid temperature because by increasing the velocity of fluid flow in the sub channel
the heat received by the fluid on the wane led to the smaller fluid temperature. Heat transfer coefficient
results obtained at a velocity flow of 0.1 m s-1
is 500 Wm-2
K-1
to 23 500 Wm-2
K-1
, at a velocity flow of 0.3
m s-1
is 3 100 Wm-2
K-1
up to 2 800 Wm-2
K-1
and in velocity flow of 0.5 m s-1
is 3 500 Wm-2
K-1
to 32 500
Wm-2
K-1
. In this experimental study use forced convection flow has a Reynolds number range from 3 991
to 29 537 and Graetz numbers from 1 371 to 41 244. The correlation of forced convection heat transfer as
follows: Nu forced = 1.641 Gz 0.4267
Keywords: correlation, forced convection, heat flux, heat transfer, hexagonal

Experimental Study of Heat Transfer Analysis in Vertical Rod…………
II. RESEARCH METHOD
This test uses 7 of diameter heating cylinders of 1.95 cm that form the sub channel to be studied only
three cylinder heater to be heated electrically. The seventh cylinders arranged by the ratio of Pitch/Diameter
(P/D) at 1.58 and put in the main test section hexagon shape with dimensions of 10 cm × 0.5 cm. The main test
section has a height of 70 cm that has one hole in each side for water circulation. (Fig.1)
Heating cylinder has a length of 65 cm by 40 cm active part throughout. The remaining 25 cm was not
heated that the velocity of the water is not immediately dropping so out of the heated section. Heating cylinder
used a type of cartridge heater heating element made of pipe filled with the element or chrome wire with
insulation elected. Each heater is capable of 1.5 kW electricity supplied from PLN net through the regulator.
In the active part of the fruit is placed thermocouple type K which are used to measure temperature
vertically. To read the results of the temperature of the thermocouple digitally used thermo
control. Thermocouple electrical voltage can be converted to Celsius and Fahrenheit by using thermo control.
In this study, water enters from 0.5 inch diameter inlet pipe into sections with a velocity of 0.1 m s-
1
; 0.3 m s-1
; and 0.5 m s-1
. Variation for each cylinder heating power is 0 W; 2985 W; 29.85 W; 149.25 W and
298.5 W, each of which is equivalent to the heat flux at the surface of the cylinder 0 Wm-2
; 10 000 Wm-2
; 100
000 Wm-2
; 500 000 Wm-2
and 1 000 000 Wm-2
.
Fig. 1: Experimental section test
Specification:
a. Heating Cylinder hanger, b. Spacer, c. Test section Main, d. Heating cylinder, e. Distributor, f. Holder Test
Section Main, g. Section Test.
For each heat flux, temperature and water heating cylinder was observed to obtain a steady state then
conducted data collection in sub channel water temperature (Ta) and in the cylinder wall heater (Tw) at a height
that corresponds.
III. RESULT AND DISCUSSION
The results obtained from experimental testing of test equipment in the reactor core model of the sub
channel arrangement of hexagons that things affect the temperature of the fluid in the sub channel including the
magnitude of the heat flux in the heating cylinder and fluid inflow velocity. To determine the fluid temperature
distribution based on the influence of velocity to 0.1, 0.3 and 0.5 m s-1
can be seen in the following Fig. 2 - 4:
a b
d
f
e
g
c

0.0 0.1 0.2 0.3 0.4
270
280
290
300
310
320
330
340
350
360
370
380
390
Ta[K]
Position [m]
Hf = 0 W/m
2
Hf = 10000 W/m
2
Hf = 100000 W/m
2
Hf = 500000 W/m
2
Hf = 1000000 W/m
2
Fig. 2. The temperature of the fluid to the height based on variations in the heat flux in the sub channel on
forced convection heat transfer to the incoming fluid velocity of 0.1 m s-1
0.0 0.1 0.2 0.3 0.4
290
300
310
320
330
Ta[K]
Position [m]
Hf = 0 W/m
2
Hf = 10000 W/m
2
Hf = 100000 W/m
2
Hf = 500000 W/m
2
Hf = 1000000 W/m
2
Fig. 3. The temperature of the fluid to the height based on heat flux variation at the sub channel on forced
convection heat transfer to the incoming fluid velocity 0.3 m s-1
0.0 0.1 0.2 0.3 0.4
290
300
310
320
330
Ta[K]
Position [m]
Hf = 0 W/m
2
Hf = 10000 W/m
2
Hf = 100000 W/m
2
Hf = 500000 W/m
2
Hf = 1000000 W/m
2
Fig. 4. The temperature of the fluid to the height based on heat flux variation at the sub channel on forced
convection heat transfer to the incoming fluid velocity of 0.5 m s-1
Fig. 2 - 4 can be seen that the fluid temperature increases due to the heat flux on the heater cylinder to
increase as well, so the greater the heat flux on the heater cylinder resulting fluid temperature goes up, it is
because the larger the heat flux on the heating cylinder heat absorbed fluid also increases.

For heating wall temperature, the magnitude of the heat flux to the wall temperature cylinder affect
heating. The greater the heat flux is given, and then the temperature of the cylinder wall heater will also be more
in line with the increase in height of the cylinder heater. This occurs because the temperature rise in the fluid
absorbs heat from the surface of the heating cylinder required high surface temperatures of the height
underneath. Here is a heat transfer coefficient which is derived in this study with numerical calculations at a
velocity of 0.1 m s-1
, 0.3 m s-1
and 0.5 m s-1
with a heat flux of 100 000 Wm-2
.
Fig. 5. Forced convection heat transfer coefficient on the fluid flow velocity of 0.1 m s-1
and heat flux 100 000
Wm-2
Fig. 6. Forced convection heat transfer coefficient on the fluid flow velocity 0.3 m s-1
Wm-2
Fig. 7. Forced convection heat transfer coefficient on the fluid flow velocity of 0.5 m s-1
Wm-2

Fig. 5 - 7 at the early entry of high fluid velocities resulting heat transfer coefficient value was
high. Flowing fluid velocity will decrease due to the forced convection flow is driven by the size of the initial
input velocity submerged by a wall heater so the heat transfer coefficient was reduced. Velocity affects the heat
transfer coefficient, the greater the velocity of fluid flow heat transfer coefficient increases. This occurs because
the faster fluid flow turbulence in fluid bigger so it can transfer heat rapidly and lead to the heat transfer
coefficient becomes large.
In this study, the physical properties of water are evaluated at the film temperature is the average of the
temperature of the cylinder wall heater with water temperature. While the dimensional characteristics used is the
hydraulic diameter. In forced convection, due to an outside force that generates the flow Nusselt numbers
correlated with Graetz numbers.
Gz = Re Pr Dh / x (2)
In these experimental studies of correlations obtained a relationship between the Nusselt numbers with
another dimensionless number that allegedly correlated with the Nusselt number. Letting X and Y is a
dimensionless number that is believed to correlate with the Nusselt number, the shape of the correlation
equation can be in the form of Equation (3).
Nu = aX b
(3)
Then the modification of Equation (3) with the operation logarithm to the base ten of the left and right
side of the equation. This is done to change the shape of the rank of Equation (3) into a linear equation. Thus
Equation (3) turns into Equation (4).
log Nu = log a + b log X (4)
To obtain Equation (4), heat transfer data is first processed so that the data obtained Nusselt numbers,
X, and Y. Then the data is correlated by using the linear regression analysis of the data, either a variable or
multivariable regression, which is available in Excel software. The results of the regression are a log value
as intercept and b as a constant value, equipped with a statistical analysis that shows the level of correlation is
generated. Then the equation in the form of Equation (3) can be obtained by using the inverse-log operation
against the results obtained by linear regression.
Fig. 8. Correlation forced convection heat transfer in the sub channel with hexagonal arrangement for turbulent
flow regime
Correlation in Fig. 8 above is obtained by connecting between Nu Log in Log Gz results of this test are
statistically coefficient of determination R 2
= 0.5524.
From the above description in order to get a new correlation in this study derived from Figure 8 above
equation y = 0.4267x + 0.2152 may be compared to 0.4267 with b as constants and 0.2152 with a log as
the intercept. To get a, log a must in the log so that the inverse inverse log of 0.2152 is 1.641. so that the results

of the experimental data, obtained correlation equations for forced convection in turbulent flow regime as
follows:
Nu forced Gz = 1.641 0.4267
(5)
This correlation applies to 1 371 ≤ Gz ≤ 41 244 and 29 537 ≤ Re ≤ 3 991 or streams that are in the
turbulent regime.
IV. CONCLUSION
From the results obtained the following conclusions:
1. At the same measurement position, the greater the heat flux supplied to the cylinder wall heater, the
higher the temperature of the cylinder wall heater. So also with the fluid temperature, the greater the
heat flux, the fluid temperature is also higher.
2. The physical properties of water are evaluated at the film temperature and heat transfer data is
correlated with the length of the characteristics of a hydraulic diameter.
3. The experimental results in forced convection flow shows that the flow in a turbulent state.
4. Correlation forced convection heat transfer as follows: Nu forced Gz = 1.641 0.4267
REFERENCES
[1] Diniardi, E., Ramadhan, AI, & Basri, H., “Literature Study of Design and Technology on Small Modular Nuclear
Reactor (SMR) type CAREM-25”, 2013, 1, 1-6.
[2] Febriyanto, C., “Experimental Study of Natural Convection Heat Transfer, Forced, and the Mixed Sub-Channel
Cylinder Hexagonal Structure”, Thesis Master program Science and Nuclear Engineering ITB, 2011, Bandung.
[3] Gimenez., MO, “CAREM Technical Aspects, Project and Licensing Status”, interregional workshop on Advanced
Nuclear Reactor Technology, 2011, Vienna.
[4] Kim, SH, & El-Genk, MS, “Heat Transfer experiments for low flow of water in rod bundles”, 1989, Int. J. Heat Mass
Transfer, 1321 – 1336.
[5] Ramadhan, A. I., “Analysis of Heat Transfer Fluid Cooling of Nano-fluids on Core Reactor PWR (Pressurized Water
Reactor) Using Computational Fluid Dynamics”, Thesis Master Program, University of Pancasila, 2012, Jakarta
[6] Ramadhan, AI, Diniardi, E., & Sutowo, C., “Literature Study of nanofluids for Application Development in the Field
of Engineering in Indonesia”, National Simposium of Application Technology I, 2013, M35-M40.
[7] Ramadhan, AI, Pratama, N., & Umar, E., “Simulation of Fluid Flow In 2000 TRIGA Reactor Using CFD CODE”,
National Seminar of Basic Science, 2009, 1 - 6.
[8] Ramadhan, AI, Setiawan, I., & Satryo, MI, „Characteristics Simulation of Fluid Flow and Temperature Cooling
(H2O) on Nuclear Reactor at core SMR (Small Modular Reactor)” Rotasi Journal, 2013, 15 (4), 33-40.
[9] Supriyadi, J., “Experimental Study of Natural Convection Heat Transfer in the sub channel in Cylinder Vertical File
Structure Longitude Cage”, Proceedings of the 17th National Seminar on Technology and Nuclear Facilities Safety
As well as the nuclear power plant, 2011, Yogyakarta

Experimental Study of Heat Transfer Analysis in Vertical Rod Bundle of Sub Channel with a Hexagonal on Small Modular Reactor

Related slideshows

More Related Content

Experimental Study of Heat Transfer Analysis in Vertical Rod Bundle of Sub Channel with a Hexagonal on Small Modular Reactor