A Study on the Heat Transfer in Shell and Tube Heat Exchanger with Various Baffle Types

2015 ◽  
Vol 727-728 ◽  
pp. 453-458
Author(s):  
Jae Hoon Lee ◽  
Si Pom Kim ◽  
Seong Jun Kim
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heating Surface ◽  
Flow Region ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Design Variables ◽  
Shell And Tube ◽  
Save Energy ◽  
Transfer Properties

Recently, variousresearches and developments of heat exchangers with high thermal efficiencyhave been in progress to save energy. Baffles are used as design variables in a way that enhancesheat transfer performance of shell and tube heat exchanger. There have beenvarious of researches and developments in the relations between baffles andheat transfer performance. Existing studies on shell and tube heat exchangersare mainly about heat transfer properties of either segmental type baffles orhelical baffles. However, there is inadequateof study with comparisons between the two types ofbaffles. Thus, this paper aims to research changes in heat transfer properties according to thenumber of segmental and helical baffles. It shows pressure drop, temperaturedifference of inlet and outlet, heating surface area of inner flow region, andheat transfer coefficient in tubes.

Comparative CFD Analysis of Maldistribution in a Shell and Tube Heat Exchanger With Conical and Cylindrical Headers

2010 ◽  
Author(s):  
Rohitha Paruchuri ◽  
T. S. Ravigururajan ◽  
Arun Muley
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Performance ◽  
Static Pressure ◽  
Flow Distribution ◽  
Transfer Performance ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Improved Performance ◽  
Flow Maldistribution

The analysis of flow maldistribution in a shell and tube heat exchanger is presented. The flow field within the headers was obtained through numerical solution of conservation equations of mass and momentum in addition to the equations of the turbulence model. The flow maldistribution inside the header was a 3-D numerical simulation with the help of commercial software To increase the performance of the heat exchanger, flow maldistribution among the tubes should be minimized.. Flow maldistribution in the header affects the heat transfer performance. The effects of the pressure drop and velocity distribution in the headers were analyzed, as it effects the heat transfer performance. The study showed that by changing the header geometry, the maldistribution can be reduced leading to improved performance. Two types of headers were considered with varying header length and inlet flow velocities from 0.8373mm/sec to 2.344mm/sec are considered. The uniformity of flow distribution improved with increasing header length, whereas it decreased with increasing flow rate. As the header length increased to 1500mm the flow maldistribution decreased and the static pressure was almost equal for all the tubes in case of a conical header. The results show that conical header minimizes flow maldistribution compared to a cylindrical header.

Effects of Baffle Overlap Proportion on Shell-Side Performance of Shell and Tube Heat Exchanger With Helical Baffles

2013 ◽  
Author(s):  
Bin Gao ◽  
Qincheng Bi ◽  
Zesen Nie
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Flow Rate ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Shell And Tube ◽  
Side Flow

Different overlap configurations of discontinuous helical baffles affect the flow pattern of the shell-side fluid directly, and thus there is a significant impact on the flow and heat transfer characteristics of the shell-side fluid. In the present paper, experiments were carried out to study the impact of baffle overlap proportion on the shell-side flow and heat transfer performance of the shell-and-tube heat exchanger with helical baffles (STHEHB). Two different shell-side friction factors, the friction factor per helical pitch (fs,1B) and the friction factor per tube length (fs,1m), were defined based on different reference lengths. The results showed that, since the baffle overlap proportion leads to different helical pitch as well as flow fields in shell side, opposite conclusions are obtained by choosing different reference length. Based on the same Reynolds number, the shell-side Nusselt number of the STHEHB with 10% baffle overlap is higher than that with 50% baffle overlap. The reason is that the larger baffle overlap proportion produces more serious leak flows and weakens the heat transfer in shell side. The comparison of heat transfer coefficient per unit pressure drop versus shell-side flow rate showed that the STHEHB with smaller baffle overlap proportion has better comprehensive heat transfer performance, but the difference between the two decreases gradually with the increase of the flow rate.

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