Numerical Modeling of Chevron Plate Heat Exchangers for Thermal Management Applications

Author(s):  
Harsh Tamakuwala ◽  
Ryan Von Ness ◽  
Debjyoti Banerjee

Plate-fin heat exchangers are widely used in industries especially aerospace, cryogenics, food and chemical process industries where high heat flux surface area per unit volume is of prime importance. These heat exchangers consists of series of corrugated plates (herringbone or chevron), separated by gasket sealing. Chevron angled plates are one of the most commonly used type of geometry. The complex design of chevron plate heat exchanger, induces high turbulence and flow reversals causing high heat transfer through the plates. This paper discusses about the computational fluid dynamics simulations conducted over a simplified geometry of Chevron Plate Heat Exchanger to understand the formulation of vortices at different Reynold’s number for various aspect ratios. A single phase laminar flow with periodic boundary condition is used for analysis of the fluid behavior in a unit pattern of the corrugation geometry. Based on different flow and geometric conditions, varying amounts of swirl-flows are observed and different behavior of shear stress and heat transfer plot along the length of the plate is observed. At higher Reynolds numbers (Re), the re-circulations and mixing by the induced vortices causes significant rise of heat flux, with marginal increase in friction factor.

2021 ◽  
Vol 245 ◽  
pp. 01048
Author(s):  
Bin Ren ◽  
Xuchen Zhu ◽  
Yannan Du ◽  
Zhe Pu ◽  
Hongliang Lu ◽  
...  

Plate heat exchangers are new-type compact heat exchangers with high heat transfer efficiency widely used in heating, food, medicine, shipbuilding and petrochemical industries. However, only the laboratory testing can accurately obtain the real heat transfer and flow resistance performance of plate heat exchanger. In this paper, the basic principles of modified Wilson plot method and equal velocity method are firstly introduced. Then the testing system including flow chart and testing instruments are discussed. Finally, contrast experiments using the different two methods are conducted. The results showed that for plate heat exchangers with equal channel, the equal velocity method and modified Wilson plot method can both be used to test the convective heat transfer performance of plate heat exchanger. The equal velocity method is recommended because the deformation of plate is relatively smaller.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Faraz Afshari ◽  
Azim Doğuş Tuncer ◽  
Adnan Sözen ◽  
Halil Ibrahim Variyenli ◽  
Ataollah Khanlari ◽  
...  

Purpose Using suspended nanoparticles in the base fluid is known as one of the most efficient ways for heat transfer augmentation and improving the thermal efficiency of various heat exchangers. Different types of nanofluids are available and used in different applications. The main purpose of this study is to investigate the effects of using hybrid nanofluid and number of plates on the performance of plate heat exchanger. In this study, TiO2/water single nanofluid and TiO2-Al2O3/water hybrid nanofluid with 1% particle weight ratio have been used to prepare hybrid nanofluid to use in plate type heat exchangers with three various number of plates including 8, 12 and 16. Design/methodology/approach The experiments have been conducted with the aim of examining the impact of plates number and used nanofluids on heat transfer enhancement. The performance tests have been done at 40°C, 45°C, 50°C and 55°C set outlet temperatures and in five various Reynolds numbers between 1,600 and 3,800. Also, numerical simulation has been applied to verify the heat and flow behavior inside the heat exchangers. Findings The results indicated that using both nanofluids raised the thermal performance of all tested exchangers which have a various number of plates. While the major outcomes of this study showed that TiO2-Al2O3/water hybrid nanofluid has priority when compared to TiO2/water single type nanofluid. Utilization of TiO2-Al2O3/water nanofluid led to obtaining an average improvement of 7.5%, 9.6% and 12.3% in heat transfer of heat exchangers with 8, 12 and 16 plates, respectively. Originality/value In the present work, experimental and numerical analyzes have been conducted to investigate the influence of using TiO2-Al2O3/water hybrid nanofluid in various plate heat exchangers. The attained findings showed successful utilization of TiO2-Al2O3/water nanofluid. Based on the obtained results increasing the number of plates in the heat exchanger caused to obtain more increment by using both types of nanofluids.


2010 ◽  
Vol 132 (11) ◽  
Author(s):  
M. J. White ◽  
G. F. Nellis ◽  
S. A. Klein ◽  
W. Zhu ◽  
Y. Gianchandani

Cryogenic and high-temperature systems often require compact heat exchangers with a high resistance to axial conduction in order to control the heat transfer induced by axial temperature differences. One attractive design for such applications is a perforated plate heat exchanger that utilizes high conductivity perforated plates to provide the stream-to-stream heat transfer and low conductivity spacers to prevent axial conduction between the perforated plates. This paper presents a numerical model of a perforated plate heat exchanger that accounts for axial conduction, external parasitic heat loads, variable fluid and material properties, and conduction to and from the ends of the heat exchanger. The numerical model is validated by experimentally testing several perforated plate heat exchangers that are fabricated using microelectromechanical systems based manufacturing methods. This type of heat exchanger was investigated for potential use in a cryosurgical probe. One of these heat exchangers included perforated plates with integrated platinum resistance thermometers. These plates provided in situ measurements of the internal temperature distribution in addition to the temperature, pressure, and flow rate measured at the inlet and exit ports of the device. The platinum wires were deposited between the fluid passages on the perforated plate and are used to measure the temperature at the interface between the wall material and the flowing fluid. The experimental testing demonstrates the ability of the numerical model to accurately predict both the overall performance and the internal temperature distribution of perforated plate heat exchangers over a range of geometry and operating conditions. The parameters that were varied include the axial length, temperature range, mass flow rate, and working fluid.


2017 ◽  
Vol 71 (5) ◽  
pp. 439-449
Author(s):  
Nikola Zlatkovic ◽  
Divna Majstorovic ◽  
Mirjana Kijevcanin ◽  
Emila Zivkovic

Plate heat exchanger is a type of heat exchanger that uses corrugated metal plates to transfer heat between two fluids. The plate corrugations are designed to achieve turbulence across the entire heat transfer area thus producing the highest possible heat transfer coefficients while allowing close temperature approaches. Subsequently, this leads to a smaller heat transfer area, smaller units and in some cases, fewer heat exchangers. In this work, an application for thermal and hydraulic computations of plate heat exchangers had been developed using Sharp Develop, an open source programming platform. During the development process, several literature methods and correlations for calculation of heat transfer coefficient and pressure drop in a plate heat exchanger have been tested and the selected four methods: Martin, VDI, Kumar and Coulson and Richardson have been incorporated into the software. The structure of the software is visually presented through several windows: a window for inserting input data, windows for showing the results of computation by each of the methods, a window for showing comparative analysis of the most important computation results obtained by all of the used methods and a help window for demonstrating the working principle of plate heat exchanger.


2013 ◽  
Vol 597 ◽  
pp. 63-74 ◽  
Author(s):  
Jan Wajs ◽  
Dariusz Mikielewicz

In the paper the experimental analysis of passive heat transfer intensification in the case of modeled plate heat exchanger is conducted. The plate heat exchanger is chosen for the analysis because this kind of heat exchangers could be prospectively applied in the ORC systems, however other areas or application are equally possible. The experimental set-up was assembled at the Department of Energy and Industrial Apparatus of Gdansk University of Technology. The passive intensification was obtained by a modification of the heat transfer surface. The roughness of surface was increased by use of glass shot.During the experiment single-phase convective heat transfer in the single phase system was studied. The experiment was done in two stages. In the first stage the model of commercial plate heat exchanger was investigated, while in the second stage the identical one but with modified heat transfer surface. Model of heat exchanger consisted of three plates. The direct comparison of thermal and flow characteristics between both devices was possible due to assurance of equivalent conditions at the inlet to the system.The thermal and hydraulic characteristics are presented. The thermal analysis shows that in some range of heat flux density the overall heat transfer coefficient was higher for the commercial heat exchanger, while for the other was higher for the heat exchanger with modified surface. The influence of larger roughness on heat transfer cannot unequivocally be evaluated. Therefore as the next step the systematic investigations of model heat exchangers (only with one hot and one cold passage) will be conducted.


Author(s):  
Chang-Nian Chen ◽  
Ji-Tian Han ◽  
Wei-Ping Gong ◽  
Tien-Chien Jen

High heat flux is very dangerous for electronic heat transfer, such as IGBT (Insulated Gate Bipolar Transistor) cooling. In order to explore and master the heat transfer and hydraulic characteristics for IGBT cooling, experiments have been carried out to study the situation mentioned above in a flat plate heat sink, which was designed for high heat flux IGBT cooling. The geometrical parameters of the test section are as follows: outline dimension 229 mm × 124 mm × 30 mm; flow channels of 229 mm × 3 mm × 4 mm in total of 20. The experiments performed at atmospheric pressure and with inlet temperatures of 25–35°C, heat fluxes of 3.5–18.9 kW/m2. The influence of temperatures, heat fluxes on IGBT surface temperature and the cooling effect of the liquid cold plate have been investigated under a range of flow rates of 280–2300 kg/m2s. It was found that the heat transfer enhancement was very obvious using this kind of small sized channel for IGBT cooling, which was tens of times of the effect than air cooling or triple of the effect than that in normal sized channels. And the heat transfer enhancement increases with increasing heat fluxes and flow rates, while it decreases with increasing inlet temperatures. Most of the experimental results show good cooling effect as expected. However, it is dangerous for the cooling system under high heat fluxes when the system starts or stops suddenly, when the Respond Time (RT) is less than 5 seconds to cut off heated power. Also, the cooling performance is bad when the heat fluxes increased greatly, which is considered as abnormal situation in operating. The effect on IGBT surface temperature of heat flux is more obvious when the average Nusselt Number is smaller. For hydraulic characteristics observed, it was found that the flow friction increased with flow rates increasing, but the pressure drops of heated flow channels ahead were slightly larger than those back, especially under large flow rates conditions. That is because the temperatures of flow heated in channels ahead are lower than those back, which causes the fluid viscosity to be higher. At last, this paper suggested a series of method for enhancing heat transfer in flat plate heat sink, and also gave some ways to avoid heat transfer dangerous situations for IGBT cooling, which can provide a basis for thermodynamic and hydraulic calculation of flat plate heat sink design and lectotype.


2003 ◽  
Vol 125 (5) ◽  
pp. 852-857 ◽  
Author(s):  
Y. Y. Hsieh ◽  
T. F. Lin

Experiments are carried out here to measure the evaporation heat transfer coefficient hr and associated frictional pressure drop ΔPf in a vertical plate heat exchanger for refrigerant R-410A. The heat exchanger consists of two vertical counterflow channels which are formed by three plates whose surface corrugations have a sine shape and a chevron angle of 60 deg. Upflow boiling of refrigerant R-410A receives heat from the hot downflow of water. In the experiments, the mean vapor quality in the refrigerant channel is varied from 0.10 to 0.80, the mass flux from 50 to 100 kg/m2s, and the imposed heat flux from 10 to 20 kW/m2 for the system pressure fixed at 1.08 and 1.25 MPa. The measured data indicate that both hr and ΔPr increase with the refrigerant mass flux except at low vapor quality. In addition, raising the imposed heat flux is found to significantly improve hr for the entire range of the mean vapor quality. However, the corresponding friction factor ftp is insensitive to the imposed heat flux and refrigerant pressure. Based on the present data, empirical correlations are provided for hr and ftp, for R-410A in the plate heat exchanger.


2008 ◽  
Author(s):  
Mehdi Nasrabadi ◽  
Ramin Haghighi Khoshkhoo

A heat exchanger is a part of micro turbines, which can improve thermal efficiency of micro turbines up to 30 percent. Some important factors in design of heat exchangers are low cost, high efficiency, small size, low weight and high performance. In this paper, design of a heat exchanger with consideration of Iranian industry’s capability has been investigated. A survey of different types of gas to-gas heat exchangers is presented and then fin-tube heat exchanger, fin-plate heat exchanger, shell & tube heat exchanger and regenerator are designed. Also, the effect of thermo hydraulic parameters on the efficiency of the three heat exchangers is investigated. Effects of these heat exchangers on the efficiency of a 100 kW micro turbine are studied and the heat exchanger with the highest efficiency is selected. The algorithm for design and modeling of the selected heat exchanger is then presented. After research on all types of heat exchangers, fin plate heat exchanger appeared to be the optimum choice for manufacturing in Iran industry. A new design program was written in MATLAB based on our suggested algorithm. Since there were some practical charts about heat transfer and pressure drop in design of the heat exchanger, all the existing experimental curves related to heat transfer and pressure of fins (required in the design of the heat exchanger) were converted to data (using “Image Processing” technique in MATLAB) and implemented in the design program.


2015 ◽  
Vol 752-753 ◽  
pp. 820-827 ◽  
Author(s):  
Vaclav Dvorak

Research of devices for heat recovery is currently focused on increasing the temperature and heat efficiency of plate heat exchangers. The goal of optimization is not only to increase the heat transfer or even moisture but also reduce the pressure loss and possibly material costs. This study deals with a plate heat exchanger with wall shaped by intermittent ridges. We used software fluent and user defined deforming to deform computational mesh and create various heat exchange walls with different number of ridges and different number of set-offs. The intention of the set-offs is to discompose boundary layer inside channels created by ridges, mix the temperature field and thus intensify the heat transfer. We used previously formulated objective function, which is a linear combination of efficiency and pressure loss, and a simple local method to optimize the heat exchanger for required pressure loss. It was found that the objective function surface is monotone and unimodal, but is not smooth. The global optimums were identified and it was shown that the optimal wall shape has no set-off for low pressure losses. The optimal count of ridges and optimal count of set-offs rise with higher required pressure loss. It was proved that the suggested objective function is suitable for optimization of a counterflow plate heat exchanger, but use of a global optimization method would be beneficial.


Author(s):  
Ru Wang ◽  
Tingyan Sun ◽  
Anja-Elsa Polzin ◽  
Stephan Kabelac

AbstractPlate heat exchangers are widely used for two-phase heat transfer in the industrial applications, and recently more attention has been paid to the plate heat exchangers with enhanced surface due to their better heat transfer performance. In this paper, the local condensation heat transfer coefficients are studied using R134a in a micro-structured plate heat exchanger. In order to obtain a more accurate prediction model, a series of measurements are conducted under various operating conditions. The mass flux of R134a varied from 47 kg/m2s to 77 kg/m2s, the saturation pressure in the condenser ranged from 6.32 bar to 8.95 bar, and the value of the heat flux was between 13 kW/m2 and 22 kW/m2. The local two-phase Nusselt number increases with the increase of the mass flux. As the saturation pressure increases, the local two-phase Nusselt number increase at the beginning of the condensation and decrease at the end of the condensation. However, the effect of heat flux on local heat transfer is irregular, due to the interaction of these parameters in the experiment. Comparing with the unstructured plate heat exchanger, R134a condenses faster at the beginning of the process in the micro-sturctured plate heat exchanger, and the local heat transfer performs better when the vapor quality is lower. Combing with the phenomenon that the overall heat flux in micro-structured plate is larger under the same working conditions, it shows that the overall heat transfer of the micro-structured plate is improved, but the local heat transfer uprades only at lower vapor qualities. A new correlation is developed, it predicts all the experimental data within the root mean square error 10%, and a new correlation for the waterside is suggested as well.


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