EFFECT OF INLET CONFIGURATION ON DISTRIBUTION OF AIR–WATER UPWARD FLOW IN A HEADER OF A PARALLEL FLOW HEAT EXCHANGER

2010 ◽  
Vol 18 (04) ◽  
pp. 265-277 ◽  
Author(s):  
NAE-HYUN KIM ◽  
SOO-HWAN KIM ◽  
JI-HOON PARK
Keyword(s):  
Heat Exchanger ◽  
Mass Flux ◽  
Flow Distribution ◽  
Parallel Flow ◽  
Upward Flow ◽  
Flow Configuration ◽  
Water Flows ◽  
Rear Part ◽  
Flat Tubes ◽  
Flow Heat

The effect of inlet configuration (parallel, normal, vertical) on flow distribution in a parallel flow heat exchanger consisting of round headers and ten flat tubes is experimentally studied using air and water. The effects of tube protrusion depth as well as header mass flux, and quality are investigated for upward flow configuration. It is shown that best flow distribution is obtained for vertical inlet configuration, followed by normal inlet and parallel inlet configuration. For upward flow, significant portion of the water flows through the rear part of the header. As protrusion depth increases, more water is forced to the rear part of the header. The effect is most significant for parallel inlet, followed by normal and vertical inlet. The effect of mass flux or quality is opposite to that of the protrusion depth. Possible explanation is provided from flow visualization results.

Characteristic Analysis of the Influence of Flow Rate Distribution in Each Flat Tube of Parallel Flow Heat Exchanger to Heat Transfer

2014 ◽  
Vol 1008-1009 ◽  
pp. 927-933
Author(s):  
Hai Jiang Yang ◽  
Ming Li ◽  
Xiao Ye Xue ◽  
Yan Liu ◽  
Kui Huang
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Transfer Rate ◽  
Flow Distribution ◽  
Uniform Flow ◽  
Parallel Flow ◽  
Transfer Efficiency ◽  
Heat Transfer Efficiency ◽  
Uniform Flow Distribution ◽  
Flow Heat

In this paper, the heat transfer rate of parallel flow heat exchanger was obtained in the condition of non-uniform flow distribution by 3D numerical simulation. The maximum theoretical heat transfer rate of parallel flow heat exchanger was obtained through 1D calculation. Ultimately, the correlation of the influence of non-uniform flow distribution on heat transfer efficiency was obtained by the comparative analysis of non-uniform flow distribution and heat transfer efficiency and regression calculation. It was found that the forecasted heat transfer efficiency error of correlation was within 2%.

A numerical study of flow distribution effect on a parallel flow heat exchanger

2001 ◽  
Vol 15 (11) ◽  
pp. 1563-1571 ◽  
Author(s):  
Kilyoan Chung ◽  
Kwan-Soo Lee ◽  
Dong-Jin Cha
Keyword(s):  
Heat Exchanger ◽  
Numerical Study ◽  
Flow Distribution ◽  
Parallel Flow ◽  
Distribution Effect ◽  
Flow Heat

Design of Cooling Towers by the Effectiveness-NTU Method

1989 ◽  
Vol 111 (4) ◽  
pp. 837-843 ◽  
Author(s):  
H. Jaber ◽  
R. L. Webb
Keyword(s):  
Heat Exchanger ◽  
Cooling Tower ◽  
Design Method ◽  
Design Methods ◽  
Parallel Flow ◽  
Basic Method ◽  
Cooling Towers ◽  
Flow Configuration ◽  
Heat Exchanger Design

This paper develops the effectiveness-NTU design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat exchanger design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A “one-increment” design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NTU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard LMED or effectiveness-NTU design methods to design cooling towers.

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