Design, Analysis and Optimization of Shell and Tube Heat Exchanger

Design, Analysis and Optimization of Shell and Tube Heat Exchanger

1 2 3 4

Mr. S. Mathivanan , Mr. A. Aravinth , Mr. A. Louis Ebi , Mr. M. Manikandan

1-Assistant Professor, 2,3&4-Students

Department of Mechanical Engineering, Hindusthan Institute of Technology, Othakkalmandapam, Coimbatore-641 032, Tamilnadu, India.

Abstract: In present day shell and tube heat exchangers are most common type of heat exchanger widely used in oil refineries and other large chemical process plants since it suits high pressure applications. The objective of the project is to design a heat exchanger with a different baffle and study the flow and temperature field inside the shell using solid works flow simulation software tool and as well as to design, fabricate two shell and tube heat exchangers one with higher heat transfer rate and other with lower heat transfer rate and to compare the results of both experimental values with results of Flow Simulations.

1. INTRODUCTION

   Heat exchangers are one of the mostly used equipments in the process industries. Heat exchangers are used to transfer heat between two process streams. One can realize their usage that any process which involves cooling, heating, condensation, boiling or evaporation will require a heat exchanger for these purposes. Process fluids, usually are heated or cooled before the process or undergo a phase change.

   Different heat exchangers are named according to their applications. For example, heat exchangers being used to condense are known as condensers, similarly heat exchangers for boiling purposes are called boilers. Performance and efficiency of heat exchangers are measured through the amount of heat transferred using least area of heat transfer and pressure drop.

   A better presentation of its efficiency is done by calculating over all heat transfer coefficient. Pressure drop and area required for a certain amount of heat transfer, provides an insight about the capital cost and power requirements (Running cost) of a heat exchanger. Usually, there is lots of literature and theories to design a heat exchanger according to the requirements. A good design is referred to a heat exchanger with least possible area and pressure drop to fulfil the heat transfer requirements.

2. COMPONENT DESIGN

   Fig 2.1 Shell

   Fig 2.2 Baffle

   Fig 2.3 Tube

   Fig 2.4 Assembled View

3. ANALYSIS REPORT

   Temperature Distribution and Surface Parameter over the shell with simple baffle:

   Fig 3.1

   Parameter	Average	Surface Area [m^2]		Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.51	0.204385463		Pressure [Pa]	101325.964	0.303691439
   Heat Transfer Coefficient [W/m2 K] /	8.9682062	0.204385463		Heat Transfer Coefficient [W/m2 K] /	40.475341	0.303691439
   Specific Heat (Cp) [J/(kgK)]	4180.2859	0.204385463		Specific Heat (Cp) [J/(kg*K)]	4180.49305	0.303691439
   Prandtl Number [ Pr]	5.3838108	0.204385463		Prandtl Number [ Pr]	5.57457055	0.303691439
   Temperature (Fluid) [°C]	30.541389	0.204385463		Temperature (Fluid) [°C]	28.9457988	0.303691439

   Parameter	Average	Surface Area [m^2]		Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.51	0.204385463		Pressure [Pa]	101325.964	0.303691439
   Heat Transfer Coefficient [W/m2 K] /	8.9682062	0.204385463		Heat Transfer Coefficient [W/m2 K] /	40.475341	0.303691439
   Specific Heat (Cp) [J/(kgK)]	4180.2859	0.204385463		Specific Heat (Cp) [J/(kg*K)]	4180.49305	0.303691439
   Prandtl Number [ Pr]	5.3838108	0.204385463		Prandtl Number [ Pr]	5.57457055	0.303691439
   Temperature (Fluid) [°C]	30.541389	0.204385463		Temperature (Fluid) [°C]	28.9457988	0.303691439

   Table 3.1

   Temperature Distribution and Surface Parameter over the Baffles with simple baffle:

   Fig 3.2

   Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.543	0.049095362
   Heat Transfer Coefficient [W/ 2/K] m	18.9930451	0.049095362
   Specific Heat (Cp) [J/(kg*K)]	4180.43517	0.049095362
   Prandtl Number [ Pr]	5.52649235	0.049095362
   Temperature (Fluid) [°C]	29.340583	0.049095362

   Table 3.2

   Temperature Distribution and Surface Parameter over the Copper Tubes with simple baffle:

   Fig 3.3

   Table 3.3

   Temperature distribution and surface parameters of the outer shell with modified baffle:

   Fig 3.4

   Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.601	0.203746379
   Heat Transfer Coefficient [W/m2 K] /	8.07375509	0.203746379
   Specific Heat (Cp) [J/(kg*K)]	4180.20439	0.203746379
   Prandtl Number [Pr]	5.34132832	0.203746379
   Temperature (Fluid) [°C]	30.8493843	0.203746379

   Table 3.4

   Temperature distribution and surface parameters of the Baffles with modified baffle:

   Fig 3.5

   Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.53	0.061282976
   Heat Transfer 2 Coefficient [W/m /K]	21.3377011	0.061282976
   Specific Heat (Cp) [J/(kg*K)]	4180.25156	0.061282976
   Prandtl Number [Pr]	5.41812553	0.061282976
   Temperature (Fluid) [°C] /td>	30.1582706	0.061282976

   Table 3.5

   Temperature distribution and surface parameters of the Copper Tubes with modified baffle:

   Fig 3.6

   Parameter	Average	Surface Area [m^2]
   Pressure [Pa]	101325.53	0.061282976
   Heat Transfer Coefficient [W/m2 K] /	21.3377011	0.061282976
   Specific Heat (Cp) [J/(kg*K)]	4180.25156	0.061282976
   Prandtl Number [Pr]	5.41812553	0.061282976
   Temperature (Fluid) [°C]	30.1582706	0.061282976

   Table 3.6

4. CONCLUSION

   The heat transfer and flow distribution are discussed in detail and proposed model is compared with simple design. Thus, the model has been improved. The assumption of changing the baffle design worked well. If hot water is raised to higher temperature, it might be help to get better heat transfer and to get better temperature difference between inlet and outlet. Moreover, the model has provided the reliable results by increase in heat transfer rate by 100%. Thus, this model can also be improved by using any other baffle design, and a software with higher computational theory. The heat transfer coefficient is poor because the temperature of the inlet hot fluid is very low. Thus, a better heater can be used for better heat transfer. And some other ways to obtain better heat transfer is to decrease the cold-water temperature to a lower level and also by using wolverine copper tubes. A SOLIDWORKS package (FLOW SIMULATION) was used for the numerical study of heat transfer characteristics of a modified baffle heat exchanger for counter flow and the results were then compared with that of simple baffle. The FLOW SIMULATION results when compared with the experimental results from different studies were well within the error limits. The study showed that there is much difference in the heat transfer performances of the typical and modified heat exchangers in the same Counter-flow configuration.

5. REFERENCES

1. Process Heat Transfer Donald Q.Kern 871 pages, illustrations, 16 × 23 cm. New York, McGraw-Hill Book Co., Inc., 1950. Journal of the Franklin Institute, Volume 250, Issue, November 1950, Pages 462-463 E.W. Hammer Jr.

2. Heat Exchangers: Theory and Practice J. TABOREK, G.

   F. HEWITT and N. AFGAN,

3. Hemisphere, Washington, DC, 1983, 992 pp.,

4. International 4, April 1984, Pages 636-637 Owen Saunders Journal of Heat and Mass Transfer, Volume 27.

5. Optimal Heat Exchanger Network Synthesis with the Detailed Heat Transfer Equipment Design M.A.S.S. Ravagnani,, J.A. Caballerob a DEQ/UEM, Universidade Estadual de Maring ´a, Av. Colombo 5790, CEP 87020900, Maring a, PR, Brazil, Departamento de Ingenier´a Quimica, Universidad de Alicante, Carretera de San Vicente del Raspeig s/n 03690,San Vicente del Raspeig, Alicante, Spain Received

   18 July 2006; received in revised form 26 October 2006; accepted 16 December 2006Available online 22 December 2006.

6. "Pasteurized Milk Ordinance" (Includes provisions from the Grade A Condensed and Dry Milk Products and Condensed and Dry Whey– Supplement I to the Grade A PMO) 2009 Revision, U.S. Department of Health and Human Services Public Health Service Food and Drug Administration

7. "The Study of Temperature Effect and Length of Pasteurization Heating on Milk Quality" Djoko Winarso, Herawati, Faculty of Veterinary Medicine of Brawijaya University, Malang. Indonesia; Benyamin Foekh, Extention Agriculture College, Malang, Indonesia. J. Agric. Food. Tech.,

8. 137-144, 2011 © 2011, TextRoad Publication ISSN 2090 424X Journal of Agriculture and Food Technology www.textroad.com.