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.

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.

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.

Heat Transfer Enhancement Analysis of Al2O3-Water Nanofluid Through Parallel and Counter Flow in Shell and Tube Heat Exchangers

2017 ◽  
Vol 16 (05n06) ◽  
pp. 1750020 ◽  
Author(s):  
S. Nallusamy ◽  
N. Manikanda Prabu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Mass Flow ◽  
Flow Rate ◽  
Heat Exchangers ◽  
Counter Flow ◽  
Overall Heat Transfer Coefficient ◽  
Shell And Tube

Heat exchanger plays an essential part in industrial sector in transferring the heat energy. Heat is exchanged between fluids in convection and conduction mode through the walls of the heat exchanger. If the heat transfer medium has low thermal conductivity, it will greatly limit the efficiency of the heat exchanger. Whenever the system acts subjected to an increase in the heat load, heat fluxes caused by more power and smaller size, cooling is one of the technical challenges faced by the industries. The objective of this research work is to evaluate the overall heat transfer coefficient through an experimental analysis on the convective heat transfer and flow characteristics of a nanofluid. In our experiment, the nanofluid consists of water and one percentage volume concentration of Al2O3-water nanofluid flowing through parallel and counter flow in shell and tube heat exchangers. About 50[Formula: see text]nm diameter of Al2O3 nanoparticles was used in this analysis and found that the overall heat transfer coefficient and convective heat transfer coefficient of nanofluid were slightly higher than those of the base liquid at same mass flow rate and inlet temperature. Here, there are three samples of dissimilar mass flow rates, which have been identified for conducting the experiments and their results are continuously monitored and reported. Finally, the observed results through an experimental investigation were presented and concluded that the enhancement of overall heat transfer coefficient is likely to be feasible by means of increasing the mass flow rate of base fluid and prepared nanofluid on the proportional basis.

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.

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.

The Sensitivity of Heat Exchanger Calculations to Uncertainties in the Physical Properties of the Process Fluids

1983 ◽  
Vol 197 (3) ◽  
pp. 171-178 ◽  
Author(s):  
L E Haseler ◽  
R G Owen ◽  
R G Sardesai
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Physical Properties ◽  
Heat Exchangers ◽  
Simple Procedure ◽  
Heat Transfer Area ◽  
Heat Exchanger Design ◽  
Shell And Tube ◽  
Design Calculations

The various processes occurring in shell and tube heat exchangers are examined for their dependence on the physical properties of the fluid streams. This dependence, coupled with estimates of likely uncertainties in the various properties, is used in developing a simple procedure for evaluating the resultant uncertainty in heat exchanger design calculations. Two case studies, which use a well-tested computer program, have shown that the above procedure adequately quantifies the uncertainties in the calculation of heat transfer area and pressure drop.

The Shell and Tube Heat Exchanger Efficiency and Its Relation to Effectiveness

2003 ◽  
Author(s):  
Ahmad Fakheri
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Heat Transfer Rate ◽  
Heat Exchangers ◽  
Transfer Rate ◽  
Counter Flow ◽  
Tube Heat Exchanger ◽  
Optimum Heat ◽  
Flow Heat ◽  
Shell And Tube

The heat exchanger efficiency is defined as the ratio of the actual heat transfer in a heat exchanger to the optimum heat transfer rate. The optimum heat transfer rate, qopt, is given by the product of UA and the Arithmetic Mean Temperature Difference, which is the difference between the average temperatures of hot and cold fluids. The actual rate of heat transfer in a heat exchanger is always less than this optimum value, which takes place in a balanced counter flow heat exchanger. It is shown that for parallel flow, counter flow, and shell and tube heat exchanger the efficiency is only a function of a single nondimensional parameter called Fin Analogy Number. Remarkably, the functional dependence of the efficiency of these heat exchangers on this parameter is identical to that of a constant area fin with an insulated tip. Also a general algebraic expression as well as a generalized chart is presented for the determination of the efficiency of shell and tube heat exchangers with any number of shells and even number of tube passes per shell, when the Number of Transfer Units (NTU) and the capacity ratio are known. Although this general expression is a function of the number of shells and another nondimensional group, it turns out to be almost independent of the number of shells over a wide range of practical interest. The same general expression is also applicable to parallel and counter flow heat exchangers.

scholarly journals Numerical Simulation of Heat Exchanger for Analyzing the Performance of Parallel and Counter Flow

2021 ◽  
Vol 16 ◽  
pp. 145-152
Author(s):  
Farid Ahmed ◽  
Md Minaruzzaman Sumon ◽  
Muhtasim Fuad ◽  
Ravi Gugulothu ◽  
AS Mollah
Keyword(s):  
Numerical Simulation ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Cold Water ◽  
Hot Water ◽  
Shell Side ◽  
Counter Flow ◽  
Tube Heat Exchanger ◽  
Shell And Tube

Heat exchangers are almost used in every industry. Among them, shell and tube heat exchangers are covering around 32% of the total heat exchanger. Numerical simulation of the Computational models is playing an important role for the prototypes including the Heat Exchanger Models for the improvement in modeling. In this study, the CFD analysis of parallel and counter flow shell and tube heat exchanger was performed. Following project, looked into the several aspects and these are the temperature, velocity, and pressure drop and turbulence kinetic energy along with the heat exchanger length. Hot water was placed in tube side and cold water was placed in shell side of the heat exchanger. Shell side cold temperature was increasing along the heat exchanger length. On the other side, tube side hot water temperature was decreasing along the tube length. This effect was more significance in counter flow rather than the parallel flow. Velocity was more fluctuating in the shell side due to presence of the baffles. Also following the same reason, pressure drop was higher in the shell side cold water rather than the tube side hot water. To measure the turbulence effect, turbulence kinetic energy was determined. Turbulence was decreasing first part of the shell and tube heat exchanger. But, it was increasing along through the rest part heat exchanger. All these observations and the outcomes are evaluated and then further analyzed

Temperature Field Prediction of Rectangular Shell-and-Tube Heat Exchanger

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
J. F. Zhou ◽  
Y. Li ◽  
B. Q. Gu ◽  
C. L. Shao
Keyword(s):  
Thermal Expansion ◽  
Temperature Field ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Operating Conditions ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Side Flow ◽  
Rectangular Shell

Shell-and-tube heat exchangers are the most common type of heat exchangers in oil refineries and other large chemical processes. In this manuscript, we demonstrate that the shell-side flow in a cylindrical shell was not as homogeneous as that in a rectangular shell. According to the periodic flow field and the arrangement of tubes in the rectangular shell, the solid-fluid coupling heat transfer model consisting of a single tube section and the outer and inner fluids was developed to represent the whole heat exchanger. Using this model, the relationship among four temperatures, namely the inlet and outlet temperatures of tube-side fluid and the upstream and downstream temperatures of shell-side fluid, was established. By dividing each tube into several tube sections at the sites of baffles, a method for predicting the temperature field of the rectangular shell-and-tube heat exchanger was proposed. Based on the node temperature correlation, all the node temperatures were obtained by iterative computation using the established relationship between the four temperatures and the operating conditions. It was found that the temperature distribution of the fluid in tube was approximately linear along axial direction, but the temperature of tube showed nonlinear regularity. The axial deformation compatibility condition for the tube bundle and shell was considered when resolving the stresses in tubes. For the model established in this paper, the mean temperature of the tube at lower position was found to be larger than that at higher position; hence the thermal expansion of the tube at the lower end is larger. In the case the tube-side fluid was heated, all tubes were pulled because of the larger axial thermal expansion of shell, and the stress in the tube with higher temperature is smaller because of the smaller strain.

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