Numerical investigation of the effects of different baffle types on the thermal performance of a shell and tube heat exchanger

Year 2018, Volume: 6 Issue: 3, 58 - 66, 30.09.2018

Halil Bayram , Gökhan Sevilgen

https://doi.org/10.21541/apjes.397414

Cited By: 1

Abstract

In this study, the thermal performance of a small
scale shell and tube heat exchanger was performed according to the baffle type
by using three dimensional Computational Fluid Dynamics (CFD) method. In
numerical calculations, segmental and continuous helical baffle types were
selected to get the comparative results. For helical baffle type, we used two
different models that the numbers of helical rotations and baffle spacing
length were different. Thus, we determined five different numerical models and
the thermal performance of each models were evaluated under different inlet
temperature values selected as 50, 60 and 70°C for the tube side. The inlet
temperature value and the mass flow rate of shell side were kept constant
during all the numerical calculations. The heat transfer calculations were
achieved by using Logarithmic Mean Temperature Difference (LMTD) method. We
also employed the Bell-Delaware method which can be used accurately for shell
and tube heat exchangers. The highest thermal performance was determined in
Case-IV which had equal baffle spacing and the maximum number of rotations for
continuous helical baffle. The predicted total pressure drop results obtained
from the numerical calculations were in good agreement with the calculated
total pressure drop from Bell-Delaware method. The lowest pressure drop and the
highest thermal performance were achieved for continuous helical baffle type
compared to the segmental equal spacing baffle type. The numerical simulations
based on CFD analysis can provide more information about heat exchangers and
this tool can be used to improve both design and the thermal performance of
heat exchangers.

Keywords

Shell and tube heat exchanger, helical baffle, segmental baffle, CFD

Numerical investigation of the effects of different baffle types on the thermal performance of a shell and tube heat exchanger

Abstract

In this study, the thermal performance of a small scale shell and tube heat exchanger was performed according to the baffle type by using three dimensional Computational Fluid Dynamics (CFD) method. In numerical calculations, segmental and continuous helical baffle types were selected to get the comparative results. For helical baffle type, we used two different models that the numbers of helical rotations and baffle spacing length were different. Thus, we determined five different numerical models and the thermal performance of each models were evaluated under different inlet temperature values selected as 50, 60 and 70°C for the tube side. The inlet temperature value and the mass flow rate of shell side were kept constant during all the numerical calculations. The heat transfer calculations were achieved by using Logarithmic Mean Temperature Difference (LMTD) method. We also employed the Bell-Delaware method which can be used accurately for shell and tube heat exchangers. The highest thermal performance was determined in Case-IV which had equal baffle spacing and the maximum number of rotations for continuous helical baffle. The predicted total pressure drop results obtained from the numerical calculations were in good agreement with the calculated total pressure drop from Bell-Delaware method. The lowest pressure drop and the highest thermal performance were achieved for continuous helical baffle type compared to the segmental equal spacing baffle type. The numerical simulations based on CFD analysis can provide more information about heat exchangers and this tool can be used to improve both design and the thermal performance of heat exchangers.

Keywords

Gövde boru tipi ısı değiştirici, helisel şaşırtma levhası, düz şaşırtma levhası, HAD

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