scholarly journals Performance Analysis of a Countercurrent Flow Heat Exchanger Placed on the Truck Compartment Roof

2011 ◽  
Author(s):  
Wamei Lin ◽  
Jinliang Yuan ◽  
Bengt Sunde´n
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Cross Flow ◽  
Countercurrent Flow ◽  
Position Change ◽  
Power Requirement ◽  
Ansys Fluent ◽  
Pin Fin ◽  
Fluent Software ◽  
Flow Heat

Due to the increasing power requirement and the limited available space in vehicles, placing the heat exchanger at the roof or the underbody of vehicles might increase the possibility to handle the cooling requirement. A new configuration of the heat exchanger has to be developed to accommodate with the position change. In this paper, a countercurrent heat exchanger is developed for position on the roof of the vehicle compartment. In order to find an appropriate configuration of fins with high thermal performance on the air side, the CFD (computational fluid dynamics) approach is applied for a comparative study among louver fin, wavy fin, and pin fin by using ANSYS FLUENT software. It is found that the louver fin has high thermal performance and low pressure drop. Thus, the louver fin is chosen to be the configuration of the countercurrent heat exchanger, which presents higher heat transfer coefficient than a cross flow heat exchanger. For a specific case, the overall size and the air pumping power of the countercurrent flow heat exchanger is lower than that one for a cross flow heat exchanger. Several suggestions and recommendations are highlighted.

scholarly journals Performance Analysis of a Countercurrent Flow Heat Exchanger Placed on the Truck Compartment Roof

2012 ◽  
Vol 4 (4) ◽  
Author(s):  
Wamei Lin ◽  
Jinliang Yuan ◽  
Bengt Sundén
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Cross Flow ◽  
Countercurrent Flow ◽  
Position Change ◽  
Power Requirement ◽  
Ansys Fluent ◽  
Pin Fin ◽  
Flow Heat ◽  
The Cross

Due to the increasing power requirement and the limited available space in vehicles, placing the heat exchanger at the roof or the underbody of vehicles might increase the possibility to handle the cooling requirement. A new configuration of the heat exchanger has to be developed to accommodate with the position change. In this paper, a countercurrent heat exchanger is developed for position on the roof of the vehicle compartment. In order to find an appropriate configuration of fins with high thermal performance on the air side, the computational fluid dynamics approach is applied for a comparative study among louver fin, wavy fin, and pin fin by using ANSYS FLUENT software. It is found that the louver fin performs high thermal performance and low pressure drop. Thus, the louver fin is chosen to be the configuration of the countercurrent flow heat exchanger. It is also found that the countercurrent flow heat exchanger presents higher heat transfer coefficient than the cross flow heat exchanger. Furthermore, the overall size and the air pumping power of the countercurrent flow heat exchanger are lower than those in the cross flow heat exchanger. Several suggestions and recommendations are highlighted.

Performance Analysis of Multi-Pass Cross-Flow Heat Exchangers

2018 ◽  
Author(s):  
Kiran Lankalapalli ◽  
Ahmed ElSawy ◽  
Stephen Idem
Keyword(s):  
Heat Exchanger ◽  
Performance Analysis ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Threshold Value ◽  
Finned Tube ◽  
Flow Heat ◽  
Rate Ratios ◽  
Side Flow

A steady state sensible performance analysis of multi-pass cross-flow finned-tube heat exchangers is reported. The investigation considers various flow circuiting, such as counter cross-flow, parallel cross-flow, and cross-flow where the tube-side flow is in parallel. A previously developed matrix approach is used to evaluate the heat exchanger performance in each tube pass. The equations required to model the thermal performance of these configurations are presented, and the thermal performance is compared for each type of flow circuiting. Thereafter a parametric study on cross-flow heat exchanger performance is performed by varying physically significant parameters such as number of transfer units (NTU) and capacity rate ratios, and the graphical results for each type of flow circuiting are presented both for both two-pass and three-pass arrangements. A consistent criterion is proposed for each case, wherein increasing the NTU beyond a certain threshold value does not significantly improve heat exchanger thermal performance.

Analysis of Flow Mal-Distribution in a Cross-Flow Heat Exchanger

2014 ◽  
Vol 592-594 ◽  
pp. 1428-1432 ◽  
Author(s):  
Krishna P. Mohan ◽  
Shekar M. Santosh ◽  
M. Ramakanth ◽  
M.R. Thansekhar ◽  
M. Venkatesan
Keyword(s):  
Heat Exchanger ◽  
Pressure Drop ◽  
Cross Flow ◽  
Flow Distribution ◽  
Ansys Fluent ◽  
Commercial Code ◽  
Uniform Flow Distribution ◽  
Flow Heat ◽  
Channel Assembly ◽  
Uniform Fluid

Flow mal-distribution is defined as the non-uniform fluid flow distribution among the parallel channels having a common header. Flow mal-distribution is present in every header channel assembly. This mal-distribution has a significant effect on the performance of the heat exchanger by increasing the pressure drop and affecting the heat transfer characteristics. However, in designing a heat exchanger, a uniform flow distribution in each channel is assumed. The present work attempts to reduce the flow mal-distribution in a cross flow heat exchanger. A numerical analysis is done using a commercial code ANSYS FLUENT 3D and the results are validated experimentally. A parametric study is done by changing the size of the channels within the heat exchanger so as to reduce the flow mal-distribution. The effect of varying channel size on flow mal-distribution and pressure drop across the heat exchanger is studied and a geometry with reduced flow mal-distribution is found.

Thermal performance escalation of cross flow heat exchanger using in-line elliptical tubes

2019 ◽  
Vol 33 (7) ◽  
pp. 587-612 ◽  
Author(s):  
Chidanand K. Mangrulkar ◽  
Ashwinkumar S. Dhoble ◽  
Pawan Kumar Pant ◽  
Nitin Kumar ◽  
Ashutosh Gupta ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Cross Flow ◽  
Flow Heat

Thermal Performance of Multipass Parallel and Counter-Cross-Flow Heat Exchangers

2006 ◽  
Vol 129 (3) ◽  
pp. 282-290 ◽  
Author(s):  
Luben Cabezas-Gómez ◽  
Hélio Aparecido Navarro ◽  
José Maria Saiz-Jabardo
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Experimental Studies ◽  
Cross Flow ◽  
Numerical Procedure ◽  
Complex Flow ◽  
Flow Heat ◽  
Small Elements ◽  
Effectiveness Data

A thorough study of the thermal performance of multipass parallel cross-flow and counter-cross-flow heat exchangers has been carried out by applying a new numerical procedure. According to this procedure, the heat exchanger is discretized into small elements following the tube-side fluid circuits. Each element is itself a one-pass mixed-unmixed cross-flow heat exchanger. Simulated results have been validated through comparisons to results from analytical solutions for one- to four-pass, parallel cross-flow and counter-cross-flow arrangements. Very accurate results have been obtained over wide ranges of NTU (number of transfer units) and C* (heat capacity rate ratio) values. New effectiveness data for the aforementioned configurations and a higher number of tube passes is presented along with data for a complex flow configuration proposed elsewhere. The proposed procedure constitutes a useful research tool both for theoretical and experimental studies of cross-flow heat exchangers thermal performance.

Cross-Flow Heat Exchanger: Volume-Averaging Formulation of a Unit Cell Model and Thermal Performance Analysis

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Hengyun Zhang ◽  
Zhaoqiang Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Cell Model ◽  
Cross Flow ◽  
Volume Averaging ◽  
Unit Cell ◽  
Unit Cell Model ◽  
Flow Heat ◽  
The Cross

A formulation of the unit cell model and the corresponding thermal performance analysis for the cross-flow heat exchanger are carried out, with the design goal of dissipating 175 W from a high-power electronic chip in a compact space. A liquid to liquid heat exchanger in the cross-flow arrangement is preferred due to its compact size and high effectiveness. The unit cell model is formulated based on the volume-averaging method to determine the heat transfer coefficient involving two heat exchanging fluids and a solid. The various factors such as channel shape, channel edge length, channel size, and heat exchanger material can be examined based on the unit cell model. The obtained heat transfer coefficients are used for the estimation of the heat exchanger thermal performance based on the effectiveness–number of transfer units (NTU) correlation. To verify the model formulation, the heat and fluid flow over the cross-flow heat exchangers are investigated through the full-field numerical computation. The amount of heat exchanged from the numerical computation is extracted and compared with the predicted results from the unit cell model. A fairly good agreement is obtained between the two approaches. Based on the unit cell model, an aluminum cross heat exchanger with eight channel layers for the hot and cold fluids, 15 channels in each layer with a channel diameter of 2 mm, is able to meet the design target.

Unit Cell Model Formulation and Thermal Performance Analysis for Cross-Flow Heat Exchanger

2016 ◽  
Author(s):  
Hengyun Zhang ◽  
Zhaoqiang Wang ◽  
Yansong Wang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Cell Model ◽  
Cross Flow ◽  
Volume Averaging ◽  
Unit Cell ◽  
Unit Cell Model ◽  
Flow Heat ◽  
The Cross

An analysis for the cross-flow heat exchanger is conducted for electronic cooling applications, with the design goal of dissipating 175W from high power chip by maintaining the chip temperature within 85 °C in a compact space. Liquid to liquid heat exchanger in cross flow arrangement is preferred due to its compact size and high effectiveness. A volume averaging formulation is developed to determine the heat transfer coefficient at the unit cell level. The effects of channel shape, channel size, and heat exchanger material are examined through the heat transfer in the unit cell model. The obtained heat transfer coefficients are also used for the estimation of the heat exchanger thermal performance based on the effectiveness-NTU method. To verify the volume averaging formulation, a full field heat and fluid flow over the cross-flow heat exchangers are investigated through numerical computation. The amount of heat exchanged is extracted and compared with the unit cell model prediction. A fairly good agreement is obtained between the two approaches. Fabrication of cross-flow heat exchanger is further discussed to meet the design target.

Comparison of Tube-Tube Collision Frequency With and Without the Use of Impingement Plate

2018 ◽  
Author(s):  
Jiří Buzík ◽  
Tomáš Létal ◽  
Pavel Lošák ◽  
Martin Naď ◽  
Marek Pernica
Keyword(s):  
Heat Exchanger ◽  
Tube Bundle ◽  
Cross Flow ◽  
Data Bank ◽  
Shell Side ◽  
Ansys Fluent ◽  
Vibration Data ◽  
Impingement Plate ◽  
Computational Fluid Dynamics Analysis ◽  
Fluent Software

The aim of the present work is to carry out the checking of the tube bundle of heat exchanger for the occurrence of tube-tube collision caused by cross-flow vibration with and without the use of impingement plate. This will be achieved using numerical 2D CFD (computational fluid dynamics) analysis. The 2D analysis is done using ANSYS Fluent software. Tube movement in the shell side is provided by UDF (user-defined function) DEFINE_SDOF_PROPERTIES. By determining the stiffness and weight of the tubes, two-way fluid and tube interaction can be achieved. Due to limitations of 2D CFD analysis, only the occurrence of the tube-tube or tube-shell collisions can be observed. Unfortunately, the first collision causes termination of the simulation due to negative volumes in dynamic mesh. Possible solutions to the issue are also discussed in presented paper. The analyzed geometry of the shell side is taken from the Heat Exchanger Tube Vibration Data Bank [2]. This publication collects heat exchanger data for which vibration phenomena have been reported. The above-mentioned geometry is a domain with tube bundle at the shell side under the inlet. In the same domain, both the tie rod and the seal strips and the 45° turn of the partitions are considered.

scholarly journals Numerical and experimental analysis of a tube-and-fin cross-flow heat exchanger with a controlled non-uniform inflow of gas

2021 ◽  
Vol 323 ◽  
pp. 00005
Author(s):  
Tomasz Bury ◽  
Małgorzata Hanuszkiewicz-Drapała
Keyword(s):  
Heat Exchanger ◽  
Water Temperature ◽  
Experimental Test ◽  
Experimental Analysis ◽  
Cross Flow ◽  
Ansys Fluent ◽  
Flow Rates ◽  
Air Inlet ◽  
Flow Heat ◽  
The Impact

The paper presents results of numerical and experimental analyses of a fin-and-tube air-water heat exchanger. The analysed device is a one-row heat exchanger with finned elliptical tubes. The aim of the analyses is to investigate the impact of a controlled non-uniform inflow of air on the heat exchanger performance. The heat exchanger was modelled numerically using the ANSYS Fluent program. The developed model was applied to simulate the heat exchanger operation in the conditions of the uniform inflow of air. Cases of an uncontrolled non-uniform inflow of gas were investigated experimentally, using a purpose-designed test station. On the experimental test station the effect of a controlled non-uniform air inflow was also achieved by placing appropriately shaped inserts in the air inlet duct, directing the air partially to the region of the water inlet header. By controlling the gas inflow, it was possible to significantly enhance the heat exchanger performance. The results of the multivariate numerical analyses conducted for the adopted parameters of the mediums (air and water volumetric flow rates and water temperature) show that the heat exchanger performance can be improved by up to almost 5% compared to a variant with a natural non-uniform air inflow taking place in the exchanger under consideration.

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