Experimental Investigation on Thermal Performance of Gas-to-Gas Micro Heat Exchanger With Three Flow Arrangements

2013 ◽  
Author(s):  
Yahui Yang ◽  
Juergen J. Brandner ◽  
Gian Luca Morini
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Cross Flow ◽  
Experimental Tests ◽  
Experimental Results ◽  
Cocurrent Flow ◽  
Micro Heat Exchanger ◽  
Mass Flow Rates ◽  
Parallel Microchannels

In this paper a double-layered microchannel gas-to-gas heat exchanger has been designed and experimentally investigated. The micro heat exchanger (micro HEX) core is based on 133 parallel microchannels machined into polished PEEK plate for both hot side and cold side. Each microchannel is 200 μm high, 200 μm wide and 39.8 mm long. The microchannel layers have been designed in order to be able to test the effect on the thermal performances of the micro heat exchanger of partition foils made in different materials and of various thicknesses. In addition, the device allows to test the layers under three different flow arrangements, namely, countercurrent flow, cocurrent flow and cross flow. Customized pressure and temperature sensors are integrated into the microHEX to enable in-situ measurements. Experimental tests have been performed for various mass flow rates of hot and cold currents. The experimental results are compared with the predictions of the classical theory for conventionally sized heat exchangers. The influence of flow arrangements and wall axial conduction on the thermal performance of the micro heat exchanger are analyzed by considering both the theory and the experimental results.

Design and Analysis of Micro Plastic Heat Exchanger

2012 ◽  
Vol 562-564 ◽  
pp. 1776-1779
Author(s):  
Yue Han ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Da Ming Wu ◽  
Xin Liang Wang
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Chemical Engineering ◽  
Mechanical Systems ◽  
Experimental Results ◽  
Micro Electro Mechanical Systems ◽  
Micro Heat Exchanger ◽  
Simulation And Experiment ◽  
Energy Engineering

The heat exchanger is widely used in energy engineering, chemical engineering etc. And with development of the MEMS (Micro Electro Mechanical Systems), many researchers are interested in the micro heat exchanger. In this paper, the micro plastic heat exchangers are manufactured by modified PPS. A heat exchanger with polypropylene (PP) is also made for comparison. Simulation and experiment are carried out to determine the thermal performance of the micro plastic heat exchangers. The experimental results are compared with that of simulation. The results show the performance of the micro plastic heat exchanger is very close to that of metal heat exchanger with the same dimension.

Applications of Performance Tables on Steady State Analysis of Multipass Parallel Cross Flow Heat Exchanger

2017 ◽  
Vol 28 ◽  
pp. 53-72
Author(s):  
Karthik Silaipillayarputhur ◽  
Ali Al-Saif ◽  
Musab Al-Otaibi
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Heat Exchanger ◽  
Mass Flow ◽  
Thermal Performance ◽  
Rate Ratio ◽  
Cross Flow ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Operational Phase

In this paper, steady state sensible performance analysis on multi pass parallel cross flow exchanger was considered. The inputs to the heat exchanger were described through meaningful physically significant parameters such as number of transfer units, capacity rate ratio and dimensionless input temperature. The inputs to the heat exchager were varied systematically and a parametric study was conducted to determine the thermal performance at each individual pass of the heat exchanger. Heat exchanger’s thermal performance was described through the discharge temperatures that were expressed in a dimensionless form. The results from the study were presented in the form of performance tables. The performance tables employed meaningful and industry recognized dimensionless input parameters and the heat exchanger‘s performance was described through dimensionless discharge temperatures at every pass of the heat exchanger. The developed performance tables shall serve two critical aspects. First, it will help the heat exchanger designers to readily choose an optimum heat exchanger. An undersized heat exchanger shall not deliver the requirements and likewise an oversized heat exchanger shall add unnecessary weight and cost. This aspect was clearly observed in this study as indefinetly increasing the number of transfer units (or surface area) beyond a threshold value didn’t enhance the heat transfer. By employing the performance tables as a guide, the heat exchanger designers can quickly ascertain the performance of the heat exchanger without having to perform simulations and/or lengthy calculations. Second, during operational phase of the heat exchanger, the performance tables can be used to understand the performance variation of the heat exchanger with respect to mass flow rates and/or can help the engineers to choose appropriate mass flow rates for the required heat transfer. The highest heat exchanger performance was observed at the lowest capacity rate ratio and likewise the lowest heat exchanger performance was observed at the highest capacity rate ratio. In-addition, during the operational phase, the performance tables can help to detect an underperforming heat exchanger and can help the engineers to schedule maintenance activity on the heat exchanger equipment.

scholarly journals Execution of a Smart Prediction Tool to Evaluate Thermal Performance in a heat exchanger by using Single Elliptical Leaf Strips with altered Angle

2019 ◽  
Vol 8 (11) ◽  
pp. 123-131
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Industrial Applications ◽  
Generalized Regression Neural Network ◽  
Prediction Tool ◽  
Pressure Drops ◽  
Transfer Rates ◽  
Mass Flow Rates

Heat exchangers are prominent industrial applications where engineering science of heat transfer and Mass transfer occurs. It is a contrivance where transfer of energy occurs to get output in the form of energy transfer. This paper aims at finding a solution to improve the thermal performance in a heat exchanger by using passive method techniques. This experimental and numerical analysis deals with finding the temperature outlets of cold and hot fluid for different mass flow rates and also pressure drop in the tube and the annular side by adding an elliptical leaf strip in the pipe at various angles. The single elliptical leaf used in experiment has major to minor axes ratios as 2:1 and distance of 50 mm between two leaves are arranged at different angular orientations from 0 0 to 1800 with 100 intervals. Since it’s not possible to find the heat transfer rates and pressure drops at every orientation of elliptical leaf so a generalized regression neural network (GRNN) prediction tool is used to get outputs with given inputs to avoid experimentation. GRNN is a statistical method of determining the relationship between dependent and independent variables. The values obtained from experimentation and GRNN nearly had precise values to each other. This analysis is a small step in regard with encomiastic approach for enhancement in performance of heat exchangers

Minimum Irreversibility Criteria for Heat Exchanger Configurations

1999 ◽  
Vol 121 (4) ◽  
pp. 241-246 ◽  
Author(s):  
F. E. M. Saboya ◽  
C. E. S. M. da Costa
Keyword(s):  
Heat Capacity ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cross Flow ◽  
Second Law Of Thermodynamics ◽  
The Other ◽  
Maximum Heat ◽  
Transfer Rates ◽  
Mass Flow Rates ◽  
Flow Heat

From the second law of thermodynamics, the concepts of irreversibility, entropy generation, and availability are applied to counterflow, parallel-flow, and cross-flow heat exchangers. In the case of the Cross-flow configuration, there are four types of heat exchangers: I) both fluids unmixed, 2) both fluids mixed, 3) fluid of maximum heat capacity rate mixed and the other unmixed, 4) fluid of minimum heat capacity rate mixed and the other unmixed. In the analysis, the heat exchangers are assumed to have a negligible pressure drop irreversibility. The Counterflow heat exchanger is compared with the other five heat exchanger types and the comparison will indicate which one has the minimum irreversibility rate. In this comparison, only the exit temperatures and the heat transfer rates of the heat exchangers are different. The other conditions (inlet temperatures, mass flow rates, number of transfer units) and the working fluids are the same in the heat exchangers.

Transient Response of Cross Flow Heat Exchangers Subjected to Simultaneous Temperature and Flow Perturbations

2015 ◽  
Vol 799-800 ◽  
pp. 665-670
Author(s):  
Karthik Silaipillayarputhur
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Convection Heat Transfer ◽  
Cross Flow ◽  
Balance Equations ◽  
Transfer Resistance ◽  
Mass Flow Rates ◽  
Flow Heat ◽  
Transient Thermal ◽  
Central Finite Difference

This paper compares the transient thermal performance between counter and parallel cross flow heat exchangers subjected to time varying inlet mass flow rates and inlet temperatures that hasn’t been previously discussed in the available literature. Specifically the transient performance of 2 pass and 3 pass cross flow heat exchangers is discussed in this paper. In the present study the energy balance equations for the hot and cold fluids and the heat exchanger wall were solved using an implicit central finite difference method. Representative values of NTU were considered, and the NTU’s of the heat exchanger were assumed to be uniformly distributed among the heat exchanger passes. Other physically significant parameters such as the capacity rate ratio and the convection heat transfer resistance ratio were systematically varied. A detailed summary based on the observations has been presented.

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.

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
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