scholarly journals Performance of Pure Crossflow Heat Exchanger in Sensible Heat Transfer Application

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5489
Author(s):  
Karthik Silaipillayarputhur ◽  
Tawfiq Al-Mughanam
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Research Work ◽  
Cross Flow ◽  
Operating Conditions ◽  
Sensible Heat ◽  
Process Industries ◽  
Flow Heat ◽  
And Performance ◽  
Marginal Improvement

All process industries involve the usage of heat exchanger equipment and understanding its performance during the design phase is very essential. The present research work specifies the performance of a pure cross flow heat exchanger in terms of dimensionless factors such as number of transfer units, capacity rate ratio, and heat exchanger effectiveness. Steady state sensible heat transfer was considered in the analysis. The matrix approach that was established in the earlier work was used in the study. The results were depicted in the form of charts, tables, and performance equations. It was observed that indeterminately increasing the number of transfer units past a threshold limit provided very marginal improvement in the performance of a pure cross flow heat exchanger. Likewise, flow pattern in a heat exchanger is usually assumed either as mixed or unmixed. However, due to various operating conditions, partially mixed conditions do exist. This work considers partially mixed conditions in the tube side of the heat exchanger. The correction factor for heat exchanger effectiveness was developed to accommodate partially mixed flow conditions in the pure cross flow heat exchanger.

scholarly journals The Effect of Flowrate and Effectiveness on Theoretical Design and Thermal Characteristic of a GHE

2018 ◽  
Vol 225 ◽  
pp. 01023
Author(s):  
T.M. Yusof ◽  
M.F. Basrawi ◽  
A. Shahrani ◽  
H. Ibrahim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Characteristic ◽  
Variable Parameter ◽  
Cross Flow ◽  
Outlet Temperature ◽  
Performance Study ◽  
Commercial Unit ◽  
Hot Climate ◽  
Flow Heat

Ground heat exchanger is an exciting technique to reduce energy consumption in building especially in hot climate countries. Implementation of GHE for commercial unit in Malaysia is almost none in record. Thus, performance study of the GHE in Malaysia is crucial to be conducted either experimentally or numerically. Therefore, this paper presents the performance of GHE in term of effectiveness, outlet temperature and rate of heat transfer based on mathematical model. The model is developed based on cross flow heat exchanger with one fluid unmixed. There are two variable parameter used in the analysis which is effectiveness and flowrate of the air for 25 meter length of a PVC pipe. Three effectiveness values which is 0.8, 0.9 and 0.99 have been analysed in this study. Meanwhile, flowrate of air is ranging from 0.02 to 0.2 kg/s. Results show that flowrate at 0.02 kg/s gives great temperature reduction in the pipe compared with higher flowrate. However, flowrate of 0.2 kg/s produces higher cooling potential. Characteristic of the GHE for the rate of heat transfer with 80, 90 and 99 percent effectiveness also have been developed and it has been found that effectiveness of 0.9 provide good combination between flowrate and the rate of heat transfer for 25 meter length of the pipe

Transient Turbulent Flow and Heat Transfer Phenomena in Plate-Fin Type Cross-Flow Heat Exchanger

2011 ◽  
Vol 32 (1) ◽  
pp. 20-32 ◽  
Author(s):  
Isak Kotcioglu ◽  
Ahmet Cansiz ◽  
Sinan Caliskan ◽  
Senol Baskaya
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Turbulent Flow ◽  
Cross Flow ◽  
Flow And Heat Transfer ◽  
Flow Heat

scholarly journals Design of Cross Flow Heat Exchanger Using Performance Charts

2018 ◽  
Vol 3 (2) ◽  
pp. 1
Author(s):  
Mohammed Al Arfaj ◽  
Nasser Al Mulhim ◽  
Abdullah Al Mulhim ◽  
Ahmed Al Naim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Surface Area ◽  
Material Flow ◽  
Cross Flow ◽  
Thermal Characteristics ◽  
Preliminary Design ◽  
Dimensionless Parameters ◽  
Flow Heat ◽  
The Right

The manuscript reviews the various steps involved in the design of a cross flow heat exchanger. Performance charts describing the thermal performance of the heat exchanger in terms of dimensionless parameters are used to develop the preliminary design of the heat exchanger. The preliminary design involves choosing the required number of heat exchanger passes, the required number of transfer units (NTU) and the capacity rate ratio for a given heat transfer application. These dimensionless parameters account for material, flow and thermal characteristics of the heat exchanger. In addition, NTU accounts for heat exchanger size, flow configuration and the type of heat exchanger. Since the preliminary design accounts for all the major characteristics of the heat exchanger, this approach is beneficial in optimizing the heat exchanger during the design phase. Performance charts indicate that indefinitely increasing the surface area (or NTU) does not increase the rate of heat transfer. There exists a threshold limit beyond which increasing the surface area adds no benefit to the heat exchanger. Instead, it just adds weight, material and cost of the heat exchanger. It must be noted that an undersized heat exchanger for a given application may not deliver the required heat transfer and while an oversized heat exchanger will increase the capital cost. Hence, it is very important to choose the right parameters during design of a heat exchanger. From the preliminary design, the detailed design for the heat exchanger can be readily extrapolated. The benefits of using performance charts in the design of a cross flow heat exchanger are described in the manuscript.

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.

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