Experimental Study of Pressure Drop and Heat Transfer of Heat Exchangers with LASH Baffles

2011 ◽  
Vol 199-200 ◽  
pp. 1523-1527 ◽  
Author(s):  
Hai Yang Sun ◽  
Cai Fu Qian
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Axial Flow ◽  
Shell Side ◽  
Pressure Drops ◽  
Comprehensive Performance

LASH or large-and-small-hole baffle is a new kind of baffle which induces axial flow in the shell-side of heat exchangers. In this paper, pressure drop and heat transfer of heat exchangers with LASH baffles were experimentally studied and compared with those in common heat exchangers with segmental baffle. It is founded that compared with the segmental baffles, pressure drops caused by LASH baffles are greatly decreased. Although the shell-side heat transfer coefficient with the LASH baffles is decreased, more comprehensive performance for heat exchangers with LASH baffles can be achieved.

Performance Study of Heat Exchangers with Continuous Helical Baffles on Different Inclination Angles

2013 ◽  
Vol 655-657 ◽  
pp. 461-464 ◽  
Author(s):  
Su Fang Song
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Performance Study ◽  
Three Dimensional Model ◽  
Shell Side ◽  
Inclination Angles

The three-dimensional model of heat exchangers with continuous helical baffles was built. The fluid flow dynamics and heat transfer of shell side in the helical baffled heat exchanger were simulated and calculated. The velocity, pressure and temperature distributions were achieved. The simulation shows that with the same baffle pitch, shell-side heat transfer coefficient increased by 25% and the pressure drop decreases by 18% in helical baffled heat exchanger compared with segmental helical baffles. With the analyzing of the flow and heat transfer in heat exchanger in 5 different inclination angles from 11°to 21°, it can be found that both shell side heat transfer coefficient and pressure drop will reduce respectively by 86% and 52% with the increases 11°to 21°of the inclination angles. Numerical simulation provided reliable theoretical reference for further engineering research of heat exchanger with helical baffles.

3-D Numerical Study on Shell-Side Comprehensive Performance of Shell-and-Tube Heat Exchanger With Combined Helical Baffles

2010 ◽  
Author(s):  
Guidong Chen ◽  
Jing Xu ◽  
Ming Zen ◽  
Qiuwang Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Comprehensive Performance ◽  
Shell And Tube ◽  
The Heat Transfer Coefficient

In order to improve heat transfer performance of conventional segmental baffled shell-and-tube heat exchangers (STHXs), the shell-and-tube heat exchanger with combined helical baffles (CMH-STHX) were invented. In the present study, the CMH-STHX is compared with three other STHXs which were set up with continuous helical baffles (CH-STHX), discontinuous helical baffles (DCH-STHX) and segmental baffles (SG-STHX), by Computational Fluid Dynamics method. The numerical results show that, for the same mass flow rate at the shell side, the overall pressure drop of the CMH-STHX is about 50% and 40% lower than that of SG-STHX and CH-STHX. The heat transfer coefficient of the CMH-STHX is between those of CH-STHX and DCH-STHX and it is 6.3% lower than that of SG-STHX. The heat transfer coefficient under unit pressure drop h/Δp is introduced to evaluate the comprehensive performance of STHXs. The h/Δp of the CMH-STHX is 7.5%, 6.5% and 87.4% higher on average than those of the CH-SHTX, DCH-STHX and SG-STHX. Furthermore, the total heat transfer rate of CMH-STHX is about 25% higher than that of SG-STHX for the same total pressure drop of shell side. Supported by these results, the new heat exchanger (CMH-STHX) may be used to replace the conventional shell-and-tube heat exchanger in industrial applications.

Experimental Study on Shell Side Heat Transfer Performance of Circumferential Overlap Trisection Helical Baffle Heat Exchangers

2011 ◽  
Author(s):  
Yaping Chen ◽  
Ruibing Cao ◽  
Jiafeng Wu ◽  
Cong Dong ◽  
Yanjun Sheng
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Shell Side ◽  
Single Thread ◽  
Helical Baffle ◽  
Inclined Angle

A set of experiments were conducted on the circumferential overlap trisection helical baffle heat exchangers with inclined angles of 20°, 24°, 28° and 32° single-thread and inclined angle of 32° dual-thread one, and a segmental baffle heat exchanger as a contrast scheme. The cylinder case of the testing heat exchanger is a common shell, while the tube bundle core could be replaced. The shell side heat transfer coefficient ho is obtained by subtract tube-side convection thermal resistance and tube wall conduction resistance from the overall heat transfer coefficient K. The curves of shell side heat transfer coefficient ho, pressure drop Δpo, Nusselt number Nuo, and axial Euler number Euz,o are presented versus axial Reynolds number Rez,o. A comprehensive performance index Nuo/Euz,o is suggested to demonstrate the integral properties of both heat transfer and flow resistance of different schemes, and the curves of Nuo/Euz,o versus Rez,o of the different schemes are presented. The results show that the scheme with inclined angle 20° performs better than other schemes, and the scheme with inclined angle 24° ranks the second, however the segment scheme ranks the last. The curves of Nuo/Euz,o of both schemes with inclined angle 32° of single-thread and dual-thread are almost coincident, even though their heat transfer coefficient and pressure drop curves are quite different. The results indicate also that for the circumferential overlap trisection helical baffle schemes the optimal inclined angle is around 20° instead of around 40° as rated by many literatures for the quadrant helical baffle schemes.

An Experimental Study of Shell-and-Tube Heat Exchangers With Continuous Helical Baffles

2007 ◽  
Vol 129 (10) ◽  
pp. 1425-1431 ◽  
Author(s):  
B. Peng ◽  
Q. W. Wang ◽  
C. Zhang ◽  
G. N. Xie ◽  
L. Q. Luo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Tube Bundle ◽  
Shell Side ◽  
Helical Baffle ◽  
Shell And Tube

Two shell-and-tube heat exchangers (STHXs) using continuous helical baffles instead of segmental baffles used in conventional STHXs were proposed, designed, and tested in this study. The two proposed STHXs have the same tube bundle but different shell configurations. The flow pattern in the shell side of the heat exchanger with continuous helical baffles was forced to be rotational and helical due to the geometry of the continuous helical baffles, which results in a significant increase in heat transfer coefficient per unit pressure drop in the heat exchanger. Properly designed continuous helical baffles can reduce fouling in the shell side and prevent the flow-induced vibration as well. The performance of the proposed STHXs was studied experimentally in this work. The heat transfer coefficient and pressure drop in the new STHXs were compared with those in the STHX with segmental baffles. The results indicate that the use of continuous helical baffles results in nearly 10% increase in heat transfer coefficient compared with that of conventional segmental baffles for the same shell-side pressure drop. Based on the experimental data, the nondimensional correlations for heat transfer coefficient and pressure drop were developed for the proposed continuous helical baffle heat exchangers with different shell configurations, which might be useful for industrial applications and further study of continuous helical baffle heat exchangers. This paper also presents a simple and feasible method to fabricate continuous helical baffles used for STHXs.

Modeling for Shell-Side Heat Transfer Coefficient and Pressure Drop of Helical Baffle Heat Exchangers

2016 ◽  
Vol 38 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Reza Tasouji Azar ◽  
Shahram Khalilarya ◽  
Samad Jafarmadar ◽  
Faramarz Ranjbar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Shell Side ◽  
Helical Baffle

scholarly journals Numerical Comparison of Thermohydraulic Performance and Fluid-Induced Vibrations for STHXs with Segmental, Helical, and Novel Clamping Antivibration Baffles

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 540
Author(s):  
S.M.A. Naqvi ◽  
Qiuwang Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Numerical Comparison ◽  
Shell Side ◽  
Cylindrical Tubes ◽  
Side Flow

The most extensively used heat exchanger in numerous research fields and industrial processes is the shell and tube heat exchanger. The selection of the baffle plays a vital role to regulate and increase the thermohydraulic performance and also to decrease fluid-induced vibrations due to shell side flow. 3-D computational fluid dynamics (CFD) and fluid-structure interaction (FSI) have been done to analyze the pressure drop, heat transfer coefficient, vortex shedding, and tube deformation due to induced vibrations among the recently developed clamping antivibration baffles with square twisted tubes, helical baffles with cylindrical tubes, and conventional segmental baffles with cylindrical tubes at different shell side flow rates by using commercial software ANSYS. Complete heat exchangers are modeled for numerical comparison; the thermohydraulic performance of the numerical model shows the suitable agreement by validating it with already published results and Esso method for single segmental baffles. It is then used to compare the performance of the same heat exchangers with CBSTT and HBCT. Thermohydraulic performance of CBSTT-STHX is better than SGCT-STHX. The heat transfer coefficient of heat exchangers with tube-to-baffle-hole clearance is higher and there is a reduction in the pressure drop compared to the results of STHXs without tube-to-baffle-hole clearance. The deformation in the tubes and vortex-induced vibrations are minimum in STHX with CBSTT than in STHXs with HBCT and SGCT.

Numerical simulation of the effect of baffle cut and baffle spacing on shell side heat exchanger performance using CFD

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Swanand Gaikwad ◽  
Ashish Parmar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Numerical Results ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Two Parameters

AbstractHeat exchangers possess a significant role in energy transmission and energy generation in most industries. In this work, a three-dimensional simulation has been carried out of a shell and tube heat exchanger (STHX) consisting of segmental baffles. The investigation involves using the commercial code of ANSYS CFX, which incorporates the modeling, meshing, and usage of the Finite Element Method to yield numerical results. Much work is available in the literature regarding the effect of baffle cut and baffle spacing as two different entities, but some uncertainty pertains when we discuss the combination of these two parameters. This study aims to find an appropriate mix of baffle cut and baffle spacing for the efficient functioning of a shell and tube heat exchanger. Two parameters are tested: the baffle cuts at 30, 35, 40% of the shell-inside diameter, and the baffle spacing’s to fit 6,8,10 baffles within the heat exchanger. The numerical results showed the role of the studied parameters on the shell side heat transfer coefficient and the pressure drop in the shell and tube heat exchanger. The investigation shows an increase in the shell side heat transfer coefficient of 13.13% when going from 6 to 8 baffle configuration and a 23.10% acclivity for the change of six baffles to 10, for a specific baffle cut. Evidence also shows a rise in the pressure drop with an increase in the baffle spacing from the ranges of 44–46.79%, which can be controlled by managing the baffle cut provided.

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

Experimental Study of Evaporation Heat Transfer Characteristics and Pressure Drops of R410A and R134a in a Multiport Mini-Channel

2009 ◽  
Author(s):  
Jatuporn Kaew-On ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Transfer Coefficients ◽  
Pressure Drops ◽  
Heat Transfer Coefficients ◽  
Evaporation Heat ◽  
Evaporation Heat Transfer ◽  
R 134A

The evaporation heat transfer coefficients and pressure drops of R-410A and R-134a flowing through a horizontal-aluminium rectangular multiport mini-channel having a hydraulic diameter of 3.48 mm are experimentally investigated. The test runs are done at refrigerant mass fluxes ranging between 200 and 400 kg/m2s. The heat fluxes are between 5 and 14.25 kW/m2, and refrigerant saturation temperatures are between 10 and 30 °C. The effects of the refrigerant vapour quality, mass flux, saturation temperature and imposed heat flux on the measured heat transfer coefficient and pressure drop are investigated. The experimental data show that in the same conditions, the heat transfer coefficients of R-410A are about 20–50% higher than those of R-134a, whereas the pressure drops of R-410A are around 50–100% lower than those of R-134a. The new correlations for the evaporation heat transfer coefficient and pressure drop of R-410A and R-134a in a multiport mini-channel are proposed for practical applications.

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