Velammal Institute of Technology, Panchetti. 2, 3, 4,5 UG Scholars, Department of Mechanical Engineering,

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1 Volume 119 No , ISSN: (on-line version) url: Performance Analysis of Single Shell Four Tube Heat Exchanger Mr. H. Bahuruteen Ali Ahamadu M.E., 1, Daniel S.G 2, Rajasekaran B 3, Selvaganesh M 4, Sujin Prasad J 5 1 Assistant Professor, Department of Mechanical Engineering, Velammal Institute of Technology, Panchetti. 2, 3, 4,5 UG Scholars, Department of Mechanical Engineering, Velammal Institute of Technology, Panchetti. ijpam.eu Abstract Heat exchangers play a major role in daily life. It has become an integral part of the industrial life. It is the device used for transferring heat from one medium to other without direct physical contact. They are widely used in space heating, refrigeration, air conditioning, power plants, petrochemical plants, petroleum refineries, and natural gas processing. The operating efficiency of these exchangers plays the key role in the overall running cost of the plant. So the designers are on a trend of developing heat exchangers which are highly efficient, compact, and cost effective. This paper consists of a simplified model of counter flow shell and tube heat exchanger having both interacting liquids as water. By using the derived dimensions of heat exchanger, a computer model using CREO has been developed and then the steady state thermal simulation in ANSYS has been performed by applying several thermal loads on different faces and edges. Index Terms CAD- Computer aided Diagram CFD-Computational fluid Dynamics I. INTRODUCTION A. Overview A heat exchanger is a heat transfer device that is used for transfer of thermal energy between two or more fluids available at different temperatures without the mixing of the two. In most heat exchangers, the fluids are separated by a heat transfer surface and the area of this surface decides the amount of transfer of heat. The fluids are at different temperatures and the one at higher temperature is known as hot fluid and another fluid is known as cold fluid. B. Types of Heat Exchangers Based on Method of Heat Transfer and Constructional Features: Shell and Tube Heat Exchanger Single Tube Heat Exchanger Parallel Plate Heat Exchanger Based on Fluid Flow Arrangement: Counter flow Parallel flow Single Pass Shell and Tube Based on Principles of Operation (Transfer Process): Regenerative type (Storage) Recuperative Type (Direct Transfer) Fluidized Bed Type C. Objectives of the study: The main objective of the present work is to fabricate a four tube one shell heat exchanger and calculate the parameters under balanced conditions. Design and fabrication of the test rig for single shell four tube heat exchanger. To determine the thermal performance parameters like overall heat transfer coefficient, effectiveness through hot testing under balanced flow condition. To compare experimental values of effectiveness and overall heat transfer with values through analysis in software. D. Organization of Paper This paper is organized as the Chapter 2 containing the design methodology. Chapter 3 discusses about the experimental setup. Later chapter 4 explains about design analysis. Results are discussed in the Chapter 5 and Conclusions are given in Chapter 6. At last, the acknowledgement and references for this project are mentioned. II. DESIGN METHODOLOGY There are many types of heat exchanger and are chosen based on their application.the type of heat exchanger which we are designing is single shell and four tube heat exchanger. Normally a shell and tube heat exchanger consists of a shell and a number of tubes. The number of tubes is called as bundle of tubes. The outer tube is called the shell. The cold fluid flows in the bundle of tubes. The hot fluid flows through the annulus region. In this paper we are concerned about the performance analysis of four tube one shell type heat exchanger under different loading conditions. For that we have first designed a four tube one shell type heat exchanger to get the dimensions of the parts involved and thereafter fabrication and testing of the actual working model has been done to see the effects of various parameters on the performance of the heat exchanger. In our project we have considered both hot fluid and cold fluid as water. We have decided the inner tube to be made of copper since it has high heat transfer co-efficient.the copper help in high heat transfer. The outer shell is made up of the mild steel sheet rolled in to a shell. The baffles in our case have been neglected since it accounts for the major pressure drop of the flowing fluid which hence needs additional equipment to maintain the flow. The initial dimension were decided and fabricated. The cold fluid was chosen to flow 13729

2 through the bundle of tubes since the pressure drop is much less in this case and the hot fluid is made to flow through the annulus region. There are many types of flow arrangements. They are parallel, counter and cross flow. We have chosen counter flow arrangements since this provides greater time and area for the flow of the heat exchange. Thus the flow arrangement was fixed and was designed. Number: 2 4) Heater: Type: storage Capacity: 10 L Fig: Heat Exchanger In this project, the methodology used in the design of the heat exchanger is studied and presented. The thermal design involves the calculation of shell side and tube side heat transfer coefficients, heat transfer surface area and pressure drops on the shell side and tube side. The mechanical design involves the calculations of thickness of pressure parts of the heat exchanger such as the shell, channel, tube etc. to evaluate the rigidity of part under design pressures. The design of the heat exchanger is then modeled in CREO and finally analyzed using ANSYS software. In this system water is taken as hot fluid and cold fluid is water. The Specific Heat of Water = Kw/kgK No phase change occurs. III. EXPERIMENTAL SETUP The design has been made properly and the whole of the setup was fabricated as per the design specifications specified below. The design has been calculated and fixed based on the requirements. Thus the dimensions are finalized as follows: 1) Tubes: Material: Copper Internal diameter of inner tube (di) = 25mm Outer diameter of inner tube (do) = 31 mm Length of inner tube = 800 mm Thickness of inner Tube = 3 mm Number = 4 2) Shell: Material: MS Internal diameter of inner tube = 200mm Outer diameter of inner tube =206 mm Length of inner tube = 0.8 m Thickness of inner Tube = 3 mm 3) Tank: Length: 300mm Breadth: 350mm Height: 450mm Capacity: 25 liters Material: steel Figure1: Test rig The above diagram shows the test rig which was designed and fabricated to check for various conditions. The water is first filled in the tank and the outlets are collected in the tank at the bottom. The hot fluid that is the hot water is made to pass through the heater and heated to required temperature and is allowed inside. The cold water directly enters from the tank. The whole of the apparatus is mounted on a frame attached with wheels for easy transportation of the test rig. The digital thermometers are installed at the inlet and outlet of the hot and cold fluid entry and exit. The reading are noted down from the digital display. The mass flow for the hot and cold fluid is also noted down by finding out the time of flow to the volume flowed. The whole of the readings were taken at the normal room temperature and pressure. IV. DESIGN ANALYSIS To validate the above mentioned observation we have made use of the CAD system. The following steps were followed for the analysis. a) Making of software model, 13730

3 b) Meshing of parts c) Thermal analysis a) Making of the software model To validate the above design we have made use of the CAD system. We have generated a software model of four tube one shell type heat exchanger using the above derived dimensions in CREO. The material assigned to the shell is Mild steel and that assigned to the tubes is Copper. Then the model is then meshed and the inputs of the various loading conditions are considered. given. The wall was chosen and the material was chosen as copper and the operating condition was specified. The results of the CFD analysis are shown in the diagrams which are given below in the results. V. OBSERVATION AND CALCULATION A. Observation The readings were taken for different temperatures of the hot fluid and its corresponding temperatures were noted down. The mass flows for the hot and cold fluid were also noted down by noting down the time. The observations are also follows: S.no fluid Inlet Hot Outlet Cold fluid Inlet Outlet Mass flow (hot) Mass flow (cold) Figure 2: heat exchanger b) Meshing of part Then the material was chosen and the corresponding sections were selected. The mesh has been generated to perform finite element analysis. In generating the mesh the mesh quality has been made fine and the smoothing has been kept high so that the results are obtained in high accuracy. The meshing plays the major role in the effectiveness of analysis. The named selections were created to define the fluid domain and the inlet and outlet. c) Figure 3: meshed parts CFD analysis: After meshing of the parts the material and other parts are chosen and the final setup of the system was done. The initial values and the flow rates of the various inlets were given. Then the values were chosen and the initial conditions were 0 C 0 C 0 C 0 C (Kg/sec) (Kg/sec) Table: observation B. Theoretical Calculation 1. First we consider the energy balance to find out the values of some unknown temperature values. Certainly some inputs like hot fluid inlet and outlet temperatures, cold fluid inlet temperature, mass flow rates of the two fluids are needed to serve the purpose. The energy balance equation may be given as: Q = m h c ph (t hi -t ho ) = m c C ph (t co -t ci ) 2. Then we consider the LMTD expression to find its value: Q = UA ΔTm For Counter flow, ΔTm = (ΔT1 - ΔT2) / (ln (ΔT1 / ΔT2)) ΔT1 = T hi - T co ΔT2 = T ho - T ci Where, ΔTm- lograrithmic mean temperature difference T hi -hot inlet temperature T ho -hot outlet temperature T ci -cold inlet temperature T co -cold outlet temperature -mass flow rate(hot) m h m c -mass flow rate(cold) The whole of the above mentioned formula was used to compute whether the theoretical calculation coincides with that of the observation. It was also used to find out the overall heat transfer co-efficient of the heat exchanger

4 The observed values of the inlet and the corresponding outlet of the hot and cold fluid helps us to infer many information because of the following reasons such as same hot and cold fluid that means same specific heat capacity, same mass flow rate of the hot and cold fluid throughout that of the experiment and at last the same operating conditions. VI. RESULTS AND DISSCUSSIONS The results of the CFD Analysis of the Single Shell four Tube Heat Exchanger in the ANSYS CFX has given the following results owing to an maximum temperature of 50 0 c corresponding to the hot inlet and the minimum temperature of 27 0 c of the cold inlet. The variation of the temperature is shown below in the figure. The results which were obtained in the CFD was found to more or less coincide with the values of the observed ones. Figure 4: analysis streamline Figure 6 :analysis cold out The change of the temperature is shown in the figure and the variation of color is used to indicate the change in temperature of the fluid flowing. Thus the CFD analysis of the four tube single shell heat exchanger for the counter flow is analyzed for the given temperature load and noted. The analyzed values are obtained by considering gravity pressure difference and various other factors which accounts for its accuracy to that of the values of the observed one in the table. The following things were observed in the experiment conducted in our test rig. The inferences are as follows: 1. The larger the temperature difference between the hot and cold fluid inlet the larger is the heat transfer that is it follows the basic law heat transfer is high when the temperature difference is high. 2. Thus the whole of effectiveness is one of the function of the temperature.it also depends on various other factors too. The effectiveness thus mainly depends on the operating condition of the heat exchanger. 3. Thus in case if the hot outlet and cold outlet is more or less near then the heat transfer at that condition is very less thus it is advised to choose a heat exchanger based on its application. VII. CONCLUSION This project provided us an opportunity to learn the working of a Single shell one tube heat exchanger and the working under varied conditions. This helped to understand the things in a clear manner the working of the heat transfer and understand in detail the mechanism of heat transfer. Thus a heat exchanger was designed based on the requirements and was checked for accuracy and the results were concluded. Figure 5: analysis cold inlet REFERENCES [1] G.V.N.Santhosh, Y.V.RamanaMurty, S.SwethaRadha, Performance Analysis of Shell and Tube heat Exchanger, International journal of Mechanical Engineering and Computer Applications, vol.2, issue 2 March-April [2] Kuruva Umamahesh, K. Venugopal, Design And Anaysis Of Double Pipe Heat Exchanger Using Computational Method, International Journal Of Professional Engineering Studies, vol. v, issue 2, July

5 [3] Vindhya Vasiny Prasad Dubey, Raj Rajat Verma, Piyush Shanker Verma & A. K. Srivastava, Steady State Thermal Analysis of Shell and Tube Type Heat Exchanger to Demonstrate the Heat Transfer Capabilities of Various Thermal Materials using Ansys, Global Journal of Researches in Engineering, vol. 14, issue 4, Version [4] Baydaa Rashid Ismael, Dr. Aruna Kumari, Design and Analysis of Heat Exchanger, in International Journal of Scientific Engineering and Technology Research, Vol.03, issue.20 Sep 2014, pp [5] Ojha Pramod Kailash, Choudhary Bishwajeet NK, Gajera Umang B, Prajapat Sumit B, Karangiya Gopal A, Design and experimental analysis of pipe in pipe heat exchanger, in International Journal Of Modern Engineering Research, Vol 5, issue 3, March 2015, pp. 42. [6] M.Z.M.Saqheeb Ali, k.mohan Krishna, D.V.V.S.Bhimesh Reddy, R.S.M.Ali, Thermal Analysis of Double Pipe Heat Exchanger by Changing the Materials Using CFD, ACM Trans. Embed. Comput. Syst International Journal of Engineering Trends and Technology (IJETT), vol. 26, no. 2, August [7] Asawari Barde, An Overview Of Shell And Tube Heat Exchanger Performance, in International Journal Of Research In Aeronautical And Mechanical Engineering, vol 4, issue 2,Feb 2016, pp

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