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.

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.

THE EFFECT OF LIQUID SUCTION HEAT EXCHANGER SUB-COOLER ON PERFORMANCE OF A FREEZER USING R404A AS WORKING FLUID

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Muhammad Nuriyadi ◽  
Sumeru Sumeru ◽  
Henry Nasution
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Cooling Capacity ◽  
Experimental Results ◽  
Working Fluid ◽  
Liquid Line ◽  
Cabin Temperature

This study presents the effect of liquid-suction heat exchangers (LSHX) sub-cooler in a freezer. The LSHX sub-cooler is a method to increase the cooling capacity of the evaporator by lowering temperature at the condenser outlet. The decrease in temperature of the condenser outlet will cause a decrease in the quality refrigerant entering the evaporator. The lower the quality of the refrigerant entering the evaporator, the higher the cooling capacity produced by the evaporator. The LSHX sub-cooler utilizes a heat exchanger to transfer heat from the outlet of the condenser (liquid line) to the suction of the compressor. In the present study, three different LSHX sub-coolers in the freezer with cabin temperature settings of 0, -10 and -20oC were investigated. The results showed that the lowest and the highest of effectiveness of the heat exchanger were 0.28 and 0.58, respectively. The experimental results also showed that EER reduction is occurred at the cabin temperature setting of 0oC and -10oC, whereas the EER improvements were always occurred at the cabin temperature settings of -20oC.

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

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.

Fabrication and Performance of a Pin Fin Micro Heat Exchanger

2004 ◽  
Vol 126 (3) ◽  
pp. 434-444 ◽  
Author(s):  
Christophe Marques ◽  
Kevin W. Kelly
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Turbine Blades ◽  
High Heat ◽  
Gas Turbine Engine ◽  
High Heat Flux ◽  
Turbine Engine ◽  
Pin Fin ◽  
Micro Heat Exchanger

Nickel micro pin fin heat exchangers can be electroplated directly onto planar or non-planar metal surfaces using a derivative of the LIGA micromachining process. These heat exchangers offer the potential to more effectively control the temperature of surfaces in high heat flux applications. Of particular interest is the temperature control of gas turbine engine components. The components in the gas turbine engine that require efficient, improved cooling schemes include the gas turbine blades, the stator vanes, the turbine disk, and the combustor liner. Efficient heating of component surfaces may also be required (i.e., surfaces near the compressor inlet to prevent deicing). In all cases, correlations providing the Nusselt number and the friction factor are needed for such micro pin fin heat exchangers. Heat transfer and pressure loss experimental results are reported for a flat parallel plate pin fin micro heat exchanger with a staggered pin fin array, with height-to-diameter ratios of 1.0, with spacing-to-diameter ratios of 2.5 and for Reynolds numbers (based on the hydraulic diameter of the channel) from 4000 to 20,000. The results are compared to studies of larger scale, but geometrically similar, pin fin heat exchangers. To motivate further research, an analytic model is described which uses the empirical results from the pin fin heat exchanger experiments to predict a cooling effectiveness exceeding 0.82 in a gas turbine blade cooling application. As a final point, the feasibility of fabricating a relatively complex micro heat exchanger on a simple airfoil (a cylinder) is demonstrated.

What is the Best Solution to Improve Thermal Performance of Storage Tanks With Immersed Heat Exchangers: Baffles or a Divided Tank?

2008 ◽  
Author(s):  
Aaron D. Wade ◽  
Jane H. Davidson ◽  
Julia F. Haltiwanger
Keyword(s):  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Thermal Stratification ◽  
Storage Tanks ◽  
Stored Energy ◽  
Tubular Heat Exchanger ◽  
Energy Delivery ◽  
Potential Methods

Prior studies of indirect water storage tanks that employ an immersed heat exchanger to discharge the stored energy have identified two potential methods of improving the rate of energy extraction: 1) an internal baffle to increase the velocity across the heat exchanger, and 2) a divided storage compartment to achieve thermal stratification. Thermal performance of these two options is compared to that of a conventional cylindrical tank during transient discharge. Each tank has a storage volume of 350 liters and a 10 m long, 0.3 m2 coiled tubular heat exchanger. For the specific configurations evaluated, the baffled heat exchanger provides the highest energy delivery rates and heat exchanger outlet temperatures. An analytic model shows the advantage of the divided storage depends on the NTU of the immersed heat exchanger. The heat exchanger employed in the present study is too small to realize the potential benefit of a divided storage. Both options, if used in the appropriate system, can improve thermal performance as measured by the rate and quality of delivered energy. The baffle is most appropriate when storage-side natural convection is the largest thermal resistance of the heat exchanger. The divided tank is useful when the NTU of the heat exchanger exceeds three.

Study on the Heat Transfer Performance of Two Kinds Material for Microstructure Heat Exchanger

2013 ◽  
Vol 712-715 ◽  
pp. 1593-1599
Author(s):  
Jian Zhuang ◽  
Da Ming Wu ◽  
Wei Wang ◽  
Ya Jun Zhang ◽  
Shi Bao Li ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Cooling Capacity ◽  
Polyphenylene Sulfide ◽  
Polymer Materials ◽  
Manufacturing Cost ◽  
Transfer Performance ◽  
Micro Heat Exchanger ◽  
Metal Materials

In order to verify the possibility that polymer materials for micro heat exchanger could replace metal materials, polymer micro heat exchangers are regarded as the study object. In terms of the experiments and the simulations by Flo EFD software, temperatures, pressures and speeds on micro heat exchanger made by aluminum and conductive plastic Polyphenylene Sulfide (PPS) were carried out analysis respectively. The results showed that the cooling capacities of micro-heat exchangers made by these two materials are quite the same. According to cooling capacity, manufacturing cost and weight, the micro heat exchanger made by conductive plastic is entirely possible to replace the existing metal heat exchanger.

Analytical and Experimental Investigation of Flow-Reversible Heat Exchangers Using Temperature-Entropy Bond Graphs

1984 ◽  
Vol 106 (2) ◽  
pp. 170-175 ◽  
Author(s):  
Rahmatallah Shoureshi ◽  
Kevin M. McLaughlin
Keyword(s):  
Experimental Investigation ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Compressible Flows ◽  
Rate Of Change ◽  
Experimental Results ◽  
Bond Graphs ◽  
Rate Oscillation ◽  
Flow Heat

Modeling of heat exchangers using true bond graphs with temperature and rate of change of entropy as power variables is presented. Techniques used for modeling of irreversabilities and compressible flows are shown. The results of two and three lump models are compared with experimental results, with the agreement between those low order models and the experimental results being good. This paper shows how well a three lump model (6th order) can predict the dynamics of an actual reversal of flow. Heat exchanger response to mass flow rate oscillation is presented.

Development and Application of a Plugging Margin Evaluation Method Taking Into Account the Fouling of Shell-and-Tube Heat Exchangers

2005 ◽  
Author(s):  
Kyeong Mo Hwang ◽  
Tae Eun Jin
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
Power Plants ◽  
Evaluation Method ◽  
Operating Time ◽  
Flow Characteristics ◽  
Shell And Tube

As the operating time of heat exchangers progresses, fouling caused by water-borne deposits and the number of plugged tubes increase and thermal performance decreases. Both fouling and tube plugging are known to interfere with normal flow characteristics and to reduce thermal efficiencies of heat exchangers. The heat exchangers of Korean nuclear power plants have been analyzed in terms of heat transfer rate and overall heat transfer coefficient as a means of heat exchanger management. Except for fouling resulting from the operation of heat exchangers, all the tubes of heat exchangers have been replaced when the number of plugged tubes exceeded the plugging criteria based on design performance sheet. This paper describes a plugging margin evaluation method taking into account the fouling of shell-and-tube heat exchangers. The method can evaluate thermal performance, estimate future fouling variation, and consider current fouling level in the calculation of plugging margin. To identify the effectiveness of the developed method, fouling and plugging margin evaluations were performed at a component cooling heat exchanger in a Korean nuclear power plant.

A Review of Micro Heat Exchanger Flow Physics, Fabrication Methods and Applications

2001 ◽  
Author(s):  
W. Jerry Bowman ◽  
Daniel Maynes
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Design Optimization ◽  
Heat Exchangers ◽  
Review Of The Literature ◽  
Fourth Section ◽  
The Third ◽  
Heat Exchanger Design ◽  
Micro Heat Exchanger ◽  
The Subject

Abstract A review of the literature in the area of micro heat exchangers is presented to provide a concise overview of the recent advances in this field of study. The review is divided into six sections. The first section reviews research focused on understanding friction and heat transfer in microchannels. The second section deals with heat exchanger design, optimization and comparison studies. The third section deals with fabrication methods used for constructing micro heat exchangers. The fourth section reviews applications of micro heat exchangers. The last two sections of the paper deal with miscellaneous topics and other reviews on the subject. The total review focuses on advances made after the early 1990’s.

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