scholarly journals Performance Analysis and Design Optimization of Shell and Tube Heat Exchangers

2021 ◽  
Author(s):  
praveen math
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Pressure Loss ◽  
Fluid Flows ◽  
Hot Water ◽  
Flow Conditions ◽  
Shell Side ◽  
Shell And Tube ◽  
Side Flow

Abstract Shell and Tube heat exchangers are having special importance in boilers, oil coolers, condensers, pre-heaters. They are also widely used in process applications as well as the refrigeration and air conditioning industry. The robustness and medium weighted shape of Shell and Tube heat exchangers make them well suited for high pressure operations. The aim of this study is to experiment, validate and to provide design suggestion to optimize the shell and tube heat exchanger (STHE). The heat exchanger is made of acrylic material with 2 baffles and 7 tubes made of stainless steel. Hot fluid flows inside the tube and cold fluid flows over the tube in the shell. 4 K-type thermocouples were used to read the hot and cold fluids inlet and outlet temperatures. Experiments were carried out for various combinations of hot and cold water flow rates with different hot water inlet temperatures. The flow conditions are limited to the lab size model of the experimental setup. A commercial CFD code was used to study the thermal and hydraulic flow field inside the shell and tubes. CFD methodology is developed to appropriately represent the flow physics and the procedure is validated with the experimental results. Turbulent flow in tube side is observed for all flow conditions, while the shell side has laminar flow except for extreme hot water temperatures. Hence transition k-kl-omega model was used to predict the flow better for transition cases. Realizable k- epsilon model with non-equilibrium wall function was used for turbulent cases. Temperature and velocity profiles are examined in detail and observed that the flow remains almost uniform to the tubes thus limiting heat transfer. Approximately 2/3 rd of the shell side flow does not surround the tubes due to biased flow contributing to reduced overall heat transfer and increased pressure loss. On the basis of these findings an attempt has been made to enhance the heat transfer by inducing turbulence in the shel l side flow. The two baffles were rotated in opposite direction to each other to achieve more circulation in the shell side flow and provide more contact with tube surface. Various positions of the baffles were simulated and studied using CFD analysis and th e results are summarized with respect to heat transfer and pressure loss.

Semi-Analytical Calculation of the Inlet Zone Performance of Ideal Shell and Tube Heat Exchangers

2010 ◽  
Author(s):  
K. Mohammadi ◽  
W. Heidemann ◽  
H. Mu¨ller-Steinhagen
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Numerical Data ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Performance Factor ◽  
Shell And Tube ◽  
Inlet Zone

A semi-analytical model is presented for the evaluation of the performance factor of the inlet zone of an E type shell and tube heat exchanger without leakage flows. The performance factor is defined as the ratio of dimensionless heat transfer coefficients and pressure drops of both vertical and horizontal baffle orientation and therefore facilitates the decision between horizontal and vertical baffle orientation of shell and tube heat exchangers. The model allows the calculation of the performance factor of the inlet zone as a function of the baffle cut, the shell-side Reynolds number at the inlet nozzle and the Prandtl number of the shell-side fluid. The application of the model requires the knowledge of the performance factor of water at baffle cut equal to 24% of the shell inside diameter. For the development of the model a numerical data basis is used due to the lack of experimental data for shell and tube heat exchangers with different baffle orientations. The numerical data are obtained from CFD calculations for steady state conditions within a segmentally baffled shell and tube heat exchanger following the TEMA standards. Air, water and engine oil with Prandtl numbers in the range of 0.7 to 206 are used as shell-side fluids. The semi-analytical model introduced for the performance factor predicts the CFD results with a relative absolute error less than 5%. The presented model has to be validated with further experimental data and/or numerical results which explain the effect of baffle orientation on the shell-side heat transfer coefficient and pressure drop in order to check the general applicability.

Simulation of Shell-Side Performance of Novel Heat Exchanger

2012 ◽  
Vol 201-202 ◽  
pp. 107-110
Author(s):  
Xing Cao ◽  
Wen Jing Du ◽  
Lin Cheng
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Heat Transfer Characteristics ◽  
Shell Side ◽  
Flow And Heat Transfer ◽  
Triangle Zone ◽  
Comprehensive Performance ◽  
Shell And Tube ◽  
Side Flow ◽  
Unit Pressure

Numerical simulation of shell-and-tube heat exchangers with novel helical baffles was carried out by using commercial codes to study shell-side flow and heat transfer characteristics. The results show that compared with shell-and-tube heat exchangers with conventional helical baffles, the ones with novel helical baffles can efficiently reduce the leakage from triangle zone so that the distributions of both the velocity field and heat transfer on tubes are more uniform. The comparison of comprehensive performance which is evaluated by heat transfer coefficient per unit pressure drop between conventional helical baffles and novel ones indicates that the latter performs better.

Experimental Study and Genetic-Algorithm-Based Correlation on Shell-Side Heat Transfer and Flow Performance of Three Different Types of Shell-and-Tube Heat Exchangers

2006 ◽  
Vol 129 (9) ◽  
pp. 1277-1285 ◽  
Author(s):  
Qiu-wang Wang ◽  
Gong-nan Xie ◽  
Bo-tao Peng ◽  
Min Zeng
Keyword(s):  
Heat Transfer ◽  
Genetic Algorithm ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Transfer Coefficients ◽  
Shell Side ◽  
Heat Transfer Coefficients ◽  
Friction Factors ◽  
Shell And Tube

The heat transfer and pressure drop of three types of shell-and-tube heat exchangers, one with conventional segmental baffles and the other two with continuous helical baffles, were experimentally measured with water flowing in the tube side and oil flowing in the shell side. The genetic algorithm has been used to determine the coefficients of correlations. It is shown that under the identical mass flow, a heat exchanger with continuous helical baffles offers higher heat transfer coefficients and pressure drop than that of a heat exchanger with segmental baffles, while the shell structure of the side-in-side-out model offers better performance than that of the middle-in-middle-out model. The predicted heat transfer rates and friction factors by means of the genetic algorithm provide a closer fit to experimental data than those determined by regression analysis. The predicted corrections of heat transfer and flow performance in the shell sides may be used in engineering applications and comprehensive study. It is recommended that the genetic algorithm can be used to handle more complicated problems and to obtain the optimal correlations.

Numerical Simulation of a Shell-and-Tube Heat Exchanger with Special Form Helical Baffles

2013 ◽  
Vol 860-863 ◽  
pp. 754-757
Author(s):  
Can Zheng ◽  
Fei Wang ◽  
Yong Gang Lei
Keyword(s):  
Numerical Simulation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Shell Side ◽  
Fluid Medium ◽  
Tube Heat Exchanger ◽  
New Type ◽  
Shell And Tube ◽  
Side Flow

A new type of helical baffles heat exchanger is presented in this paper. Comparative study, through numerical simulation, was undertook between the new helical baffles heat exchanger and segmental baffle board heat exchanger in shell side flow and heat exchange characteristics. Fluid medium in the shell side is air. At the same velocity in the same flow conditions, pressure drop of helical baffles heat exchangers fell by an average of 26.8% compared with segmental baffle board heat exchangers, and the unit pressure drop of the heat transfer ratio of helical baffles heat exchanger increased by an average of 40.6%.

Novel Heat Exchanger Design With Rectangular Shell Geometry

2014 ◽  
Author(s):  
Vipul Patel ◽  
Rajesh Patel ◽  
Vimal Savsani
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Industrial Applications ◽  
Shell Side ◽  
Counter Flow ◽  
Heat Exchanger Design ◽  
Operation Conditions ◽  
Shell And Tube ◽  
Rectangular Shell

Shell and Tube Heat Exchangers (STHE) are the most versatile type of heat exchangers used in industrial applications. The shape of Shell side of the traditional STHE’s is cylindrical for industrial applications. On one hand, STHE have some good features but on the other hand, it has some limitations due to the cylindrical geometry of the shell side. Some of these limitations are maximum two shell pass is possible as per TEMA layout, complete counter flow cannot be achieved, possibility of reverse heat transfer when number of tube passes are more, tubes are always laid parallel to shell and mounting over the entire length of shell is not possible when impingement plate provided etc. The objective of this study is to design a novel heat exchanger to overcome the limitations of traditional STHE. An experimental setup has been designed with rectangular shell side for STHE. The novel heat exchanger provides the flexibility to increase the number of shell pass and complete counter flow can be achieved due to rectangular geometry of shell side. For the same heat transfer rates, the proposed novel heat exchanger design provides better Effective Mean Temperature Difference (EMTD) and hence less surface area for heat transfer in comparison with traditional STHE. The experiments have been conducted on novel heat exchangers under different operation conditions of hot and cold fluids. The experiment results are compared with theoretical estimations of overall heat transfer coefficient and Log Mean Temperature Difference (LMTD) for traditional shell and tube heat exchangers for the same operation conditions. The results show that under the same operation conditions, the performance of novel heat exchanger is much better than traditional STHE.

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.

scholarly journals A CFD investigation and heat transfer augmentation of double pipe heat exchanger by employing helical baffles on shell and tube side

2021 ◽  
pp. 300-300
Author(s):  
Sobhanadri Anantha ◽  
Senthilkumar Gnanamani ◽  
Vivekanandan Mahendran ◽  
Venkatesh Rathinavelu ◽  
Ramkumar Rajagopal ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
The Other ◽  
Outlet Temperature ◽  
Shell Side ◽  
Shell And Tube ◽  
Double Pipe ◽  
Pipe Heat

The inclusion of baffles in a double pipe heat exchanger is becoming increasingly important as it improves the heat exchanger's performance. CFD analysis is used in this paper to investigate the performance of double pipe heat exchangers with and without helical baffles on both shell tube sides. The 3D Computation Fluid Dynamics (CFD) model was created in Solid Works, and the FloEFD software was used to analyze the conjugate Heat Transfer between the heat exchanger's tube and shell sides. Heat transfer characteristic like Outlet temperature of shell and tube are investigated along with pressure drop on shell and tube side. Based on CFD results of Double Pipe Heat exchanger with helical baffle on both shell side and tube side (Type 4) gives the better results than the other type of heat exchangers with an increased pressure drop than the others, results reveals that type 4 outlet temperature of shell side is 8% higher and on tube side it is 5.5% higher, also pressure drop on shell side is 12% higher and on tube side it is 42% higher than the other types.

scholarly journals Optimization and CFD analysis of a shell-and-tube heat exchanger with a multi segmental baffle

2020 ◽  
pp. 293-293
Author(s):  
Ahmet Aydin ◽  
Halit Yaşar ◽  
Tahsin Engin ◽  
Ekrem Büyükkaya
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Exchanger ◽  
Flow Field ◽  
Heat Exchangers ◽  
Operating Cost ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Side Flow

The Shell-and-tube type heat exchangers have long been widely used in many fields of industry. These types of heat exchangers are generally easy to design, manufacturing and maintenance, but require relatively large spaces to install. Therefore the optimization of such heat exchangers from thermal and economical points of view is of particular interest. In this article, an optimization procedure based on the minimum total cost (initial investment plus operational costs) has been applied. Then the flow analysis of the optimized heat exchanger has been carried out to reveal possible flow field and temperature distribution inside the equipment using computational fluid dynamics. The experimental results were compared with computational fluid dynamics analyses results. It has been concluded that the baffles play an important role in the development of the shell side flow field. This prompted us to investigate new baffle geometries without compromising from the overall thermal performance. It has been found that the heat exchanger with the new baffle design gives rise to considerably lower pressure drops in the shell side, which in turn reducing operating cost. The new baffle design is particularly well suited for shell-and-tube heat exchangers, where a viscous fluid flows through shell side with/out phase change.

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