Thermal and Hydraulic Design of Three Fluid Shell and Tube Heat Exchanger

Abstract

Three Fluid Shell and Tube Heat Exchanger represents a new type of heat exchangers in the Shell and Tube Heat Exchanger (STHE) category. It consists of an outer shell and plurality of double pipe tubes incorporated inside the heat exchanger with three uids exchanging heats compared to two uids in a conventional STHE. In the Three Fluid STHE, the uid owing in the annulus between the inner and outer tubes exchanges heat simultaneously with the uid on the shell side and the uid owing through the inner tubes. There are two heat conducting walls through which heat transfer takes place instead of a single heat conduction wall in STHE. Three Fluid STHE can be used for many specific applications such as heat recovery system, power production, chemical processing, air conditioning, cryogenics, food pro- cessing, distillation, transport, pharmaceutical industry, etc. It has various advantages compared to conventional STHE in terms of compactness and overall performance. There is no methodology available to carry out the design / check the performance of Three Fluid STHE. Hence, a methodology has been evolved to carry out the design of Three Fluid STHE starting with the fundamental concepts of heat transfer. The work includes understanding the design procedure of STHE with a parametric case study, then extending the work to design methodology for Bayonet Tube Heat Exchanger and Finally to design of Three Fluid STHE. The calculations and performance characteristics are further elaborated during the analysis. Also the parameters during the calculations were validated using HTRI and HTFS software.