Heat Exchangers are devices used to enhance or facilitate the flow of heat. Every living thing is equipped in some way or another with heat exchangers. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment. The design of STHE including thermodynamic and fluid dynamic design, cost estimation and optimiza- tion, represents a complex process containing an inte- grated whole of design rules and empirical knowledge of various fields.
The Shell and tubeheat exchangers are generally built of a bundle of round tubes mounted in a cylindrical shell with the tube axis parallel to that of the shell. One fluid flow inside the tubes, the other flows across and along the tubes. The major components of this exchanger are tubes, shell, front end head, rear end head, baffles, and tube sheets. A variety of different internal constructions are used in shell and tube exchangers depending on the desired heat transfer and pressure drop performance and the methods employed to reduce the thermal stress, to prevent leakages, to provide for ease of cleaning, to contain operating pressures and temperatures, to control corrosion, to accommodate highly asymmetric flows, and so on. Shell and tube exchangers are classified and constructed in accordance with the widely used TEMA standards and ASME boiler and pressure vessel codes. TEMA has developed a notation system to designate major types of shell and tube exchangers. In this system, each exchanger is designated by a three-letter combination, the first letter indicating the front-end heat type, the second the shell type, and the third the rear-end head type. Some common shell and tube exchangers are AES, BEM, AEP, CFU, AKT, and AJW.
In present day shell and tubeheatexchanger is the most common type heatexchanger widely used in oil refinery and other large chemical process, because it suits high pressure application. The process in solving CFD consists of modeling and meshing the basic geometry of shell and tubeheatexchanger using CFD package ANSYS 13.0. The objective of the project is design of shell and tubeheatexchanger with helical baffle and study the flow and temperature field inside the shell using ANSYS software tools. The heatexchanger contains 7 tubes and 800 mm length shell diameter 90 mm. The helix angle of helical baffle will be varied from 00 to 20°. In CFD will show how the temperature varies in shell due to different helix angle and flow rate. The flow pattern in the shell side of the heatexchanger 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 heatexchanger. There is a wide application of coiled heatexchanger in the field of industrial applications for its enhanced heat transfer characteristics and compact structure. Lots of researches are going on to improve the heat transfer rate of the helical coil heatexchanger. Here, in this work, an analysis has been done for a tube-in-tube helical heatexchanger with constant heat transfer coefficient with parallel flow. There are various factors present that may affect the heat transfer characteristics of the heatexchanger. The flow pattern in the shell side of the heatexchanger 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 heatexchanger. There is a wide application of coiled heatexchanger in the field of industrial applications for its enhanced heat transfer characteristics and compact structure. Lots of researches are going on to improve the heat transfer rate of the helical coil heatexchanger. Here, in this work, an analysis has been done for a tube-in-tube helical heatexchanger with constant heat transfer coefficient with parallel flow. There are various factors present that may affect the heat transfer characteristics of the heatexchanger.
Andre L.H. Costa and Eduardo M. Queiroz  presented a paper which deals with study about the design optimization of shell-and- tubeheat exchangers. The formulated problem consists of the minimization of the thermal surface area for a certain service, involving discrete decision variables. Additional constraints represent geometrical features and velocity conditions which must be complied in order to reach a more realistic solution for the process task. The optimization algorithm is based on a search along the tube count table where the established constraints and the investigated design candidates are employed to eliminate non optimal alternatives, thus reducing the number of rating runs executed.
Abstract: Heatexchanger is a device which provides a flow of thermal energy between two or more fluids at different temperatures. There are many problems created in the segmental heatexchanger during and after the work. The major causes of this problem is the geometry of heatexchanger, type of fluid used, type of material etc., The purpose of this work is to design the shell and tubeheatexchanger which is one among the majority type of liquid –to –liquid heatexchanger. Since the important design parameters such as the pitch ratio, tube length, and tube layer as well as baffle spacing has a direct effect on pressure drop and effectiveness, they are considered to be the key parameters in this work. General design consideration and design procedure are also illustrated in this work. The analysis of orifice baffle and convergent divergent tube in a shell and tubeheatexchanger are experimentally carried out. The newly designed heatexchanger obtained a maximum heat transfer coefficient and a lower pressure drop. From the numerical experimentation, the result shows that the performance of heatexchanger increases in modified baffle and tube than the segmental baffle and tube arrangement. Keywords: modified heatexchanger, pressure drop, bell –Delaware method, modified baffle and tube
Many of the scholars have studied the experimental investigations over the time and found out heat transfer characteristics of the nature of the corrugated tube therefore experimentation is an impossible thing which requires a full-scale mockup with large test rigs and high scale equipment’s which requires high capital, As the technology has been developed and advanced with the time there is no need now to perform lengthy and time taking tasks to get the results or to get the job done. When the very first simulation has started the capability of simulations have gone thus par with the time now the faculties in computational domain are much more advanced than before therefore to avoid cost that comes with the experimentation and complete the project in a time effective away we are employing the advanced simulation techniques in this project initially the design have been designed in the solid works and then the flow simulation is carried out to determine the heat transfer rates of the models we have done.
The main purpose of heatexchanger is the transfer of heat from one fluid to another. Among all type of heatexchanger, shell and tubeheatexchanger most commonly used. . The performances of shell and tubeheatexchanger mainly depend on baffle geometry and tube geometry. Also fouling consideration and the fluids used in shell and tube have large effect on heatexchanger performance. The effect of fouling is considered in heatexchangerdesign by including shell side tube side fouling resistance. The tube side fluid should be corrosive and have high fouling resistance. Baffle is one of the major parts of shelltubeheatexchanger. Baffles are designed to direct shell side fluid across the tube bundle efficiently as possible. The most common type of baffle is the single segmental baffle which changes the direction of shell fluid to archive cross flow. Now a day’s helical baffles and flower baffles are used in shell and tubeheatexchanger instead of segmental baffles and got better results. There were lots of experiments conducted in baffle plate in order to increase heatexchanger performance. M.M. Elias experimentally investigated the effect of different nano particle shape on the overall heat transfer coefficient and shell and tubeheatexchanger with different baffle angle (0, 10, 20, 30, 40, and 50). Boehmite alumina used as nano particle. In all shapes cylindrical nano particle show grater over all heat transfer coefficient .20° baffle angle show better heat transfer than other angles Arjun K.S [2 ] investigated the performance of one shell and tubeheatexchanger model with helical angle vary from 0 to 40° .They got an effective heat transfer hike by the impact of helical angle and helix baffle inclination angle 20°makes the best performance of shell and tubeheatexchanger .Yonghua you  solved a numerical model shell and tubeheatexchanger with flower baffles for Reynold number ranging from 6813 to 22326.They found that, the mean heat transfer coefficient and convective heat transfer coefficient increase with increase of Reynolds number. Also they found that over all thermal hydraulic behaviour h sm /Δp decreases with increase of Reynolds number. Xiaoming xiao  investigated the heat transfer performance of fluid with different prandel number fluid in the shell side of helical baffle side of heatexchanger. The value of ‘pr’ ranges from 5 to 15000 and helical tilt angle from 10° to 50°. High prandel number fluid with small helical angle reveals to be optimum choice. In this study optimization of shell and tubeheatexchanger have done for maximum heat transfer. Optimization mainly on for tube arrangement and baffle angle .
The importance of mini shell and tubeheat exchangers in industrial and other engineering applications cannot be underestimated. Hence in this project, a mini and shell and tubeheatexchanger was developed on the laboratory scale using an optimized LMTD technique before embarking on the design and fabrication. The performance of the heatexchanger was assessed and evaluated to determine the optimum combination of design parameters for the transfer of heat between the two fluids involved in the STHE without mixing. It was discovered from the obtained results that the Bell-Delaware correlation produced the optimal value of shell fluid film coefficient over the other correlation techniques at any parametric iterations. Kern technique was the closest with correction factors between 0.8440 and 0.9850. There was also an inverse relationship between the shell fluid film coefficient and heat transfer rate. Though, irrespective of the shell diameters, the heat transfer rate is constant. But there is an inverse relationship between the LMTD and the heat transfer rate under any shelldesign parameters. In addition, there was a direct relationship between h o and the LMTD. While h o decreases
This paper is concerned with the study of shell & tube type heatexchanger. Also the main components of shell and tube type heatexchanger are shown in drawing and its detail discussion is given. Moreover the constructional details and design methods of shell and tube type heat exchangers has been given from which of that the Kern method for design is described in detail with step inside the paper. Also some of research paper is studied and then the review from those papers is also described in the paper with some of review work in detail.
The excessive tube fouling usually causes performance problems. In a heatexchanger during normal operations the tube surface gets covered by deposits of ash, soot, and dirt and scale etc. This phenomenon of rust formation and deposition of fluid impurity is called fouling. Deposition of foul ants on the inside of the tube surface reduces the available flow area and increase the skin friction, causing an increase in pressure loss and decrease in heat transfer. Uneven rates of fouling of tubes usually occur in units with low flow velocity design. Uneven fouling may occur on the shell side of the tubes due to a poor baffling scheme which leads to a flow misdistribution. Highly non-uniform fouling on severely modifies the metal temperature profile in some tubes resulting in large tubes to tube sheet joint leads. Thermal stresses in the internal of the heatexchanger can cause serious degradation of heat duty. The most obvious example is failure of welds joining pass partition plates to each other and to the channel.
For efficiency, heat exchangers are designed to maximize the surface area of the wall between the two fluids, while minimizing resistance to fluid flow through the exchanger. The exchanger's performance can also be affected by using fins or corrugations in one or both directions, which increase surface area and may channel fluid flow or induce turbulence. The driving temperature across the heat transfer surface varies with position, but an appropriate mean temperature can be defined. In most simple systems this is the "log mean temperature difference”
Different streams of numerical solution techniques are Finite difference method, Finite element method, spectral method and finite volume method. Following steps will be performed by all the numerical methods. Post-Processor: As in pre-processing a huge amount of development work has recently taken place in the post- processing field. Owing to the increased popularity of engineering workstations many of which have outstanding graphics capabilities, the leading CFD packages are now equipped with versatile data visualization tools.
55°C and 65°C the above procedure was repeated and the readings were observed. Based on the experimental design combination experiments were conducted for water – hot water system and their results are tabulated in the Table 3. The performance of the heatexchanger is assessed by computing overall heat transfer coefficient. The overall heat transfer coefficient is calculated using log mean temperature difference (LMTD) approach because the inlet temperature, outlet temperature and flow rate of the cold and hot water are known. The overall heat transfer coefficient of shell and tubeheatexchanger is calculated by using below equations.
Shell-and-tubeheat exchangers are used widely in the chemical process industries, especially in refineries, because of the numerous advantages they offer over other types of heat exchangers. A lot of information is available regarding their design and construction. The present notes are intended only to serve as a brief introduction.
Andre L.H. Costa and Eduardo M. Queiroz  presented a paper which deals with study about the design optimization of shell-and-tubeheat exchangers. The formulated problem consists of the minimization of the thermal surface area for a certain service, involving discrete decision variables. Additional constraints represent geometrical features and velocity conditions which must be complied in order to reach a more realistic solution for the process task.
Front-End And Rear End Covers: They are containers for tube fluids for every pass. In many rear end head designs, a provision has been made to take care of thermal expansion of whole tube bundle. The front-end head is stationery while the rear end head could be either stationary or floating depending upon the thermal stresses between the tubes and shell.
In this paper a simplified approach to optimize the design of ShellTubeHeatExchanger [STHE] by flow induced vibration analysis [FVA] is presented. The vibration analysis of STHE helps in achieving optimiza- tion in design by prevention of tube failure caused due to flow induced vibration. The main reason for tube failure due to flow induced vibration is increased size of STHE. It is found that in case of increased size of STHE, the surface area and number of tubes increases, thus the understanding and analysis of vibration be- comes a very difficult task. Again it is found that flow induced vibration analysis is considered as an integral part of mechanical & thermal design of STHE. The detailed design, fabrication, testing and analysis work was carried out at Alfa Laval (India), Ltd., Pune-10.
CFD is a sophisticated computationally-based design and analysis technique. CFD software gives you the power to simulate flows of gases and liquids, heat and mass transfer, moving bodies, multiphase physics, chemical reaction, fluid-structure interaction and acoustics through computer modeling. This software can also build a virtual prototype of the system or device before can be apply to real-world physics and chemistry to the model, and the software will provide with images and data, which predict the performance of that design.
Our study aims at studying simple un-baffled heatexchanger, which is more similar to the double pipe heat exchangers. Almost no study is found for an un-baffled shell and tubeheatexchanger. Thus general correlations of heat transfer and pressure drop for straight pipes can be useful to get an idea of the design. Generally there has been lot of work done on heat transfer  and pressure drop  in heat exchangers. Pressure drop in a heatexchanger can be divided in three parts. Mainly it occurs due to fanning friction along the pipe. In addition to this it also occurs due to geometrical changes in the flow i.e. contraction and expansion at inlet and outlet of heatexchanger . Handbook of hydraulic resistance pro- vides the correlations for the pressure losses in these three regions separately by introducing the pressure loss coefficients.
Abstract: A heatexchanger is an equipment used for transferring heat from one medium to another. There is a wide application of coiled heatexchanger in field of cryogenics and other industrial applications for its enhanced heat transfer characteristics and compact structure. Lots of researches are going on to improve the heat transfer rate of the heatexchanger. Here, We have fabricated the shell and tubeheatexchanger with selecting the materials on the primary objective of enhancing the transfer effectiveness. We casted the tube in the spiral shape with the helical angle of 30 degree. Then we intended to perform calculation on the heat transfer effectiveness. We are intended to show the merits of spiral coiled heatexchanger to that of the conventional parallel type heatexchanger.