DESIGN OF MULTI-STREAM HEAT EXCHANGER

Abstract

In this paper a design methodology of Multistream Plate Fin Heat Exchanger is discussed extensively. As for the two streams heat exchanger design methods is universally available because of many research has been done commonly known few methods are such as LMTD Method and NTU-effectiveness method, but in case of designing of multi-stream heat exchanger there is no such extensive research or mrthod is available that is universally accepted so this thesis is an attempt to design a multi-stream heat exchanger by thermo hydraulic model. This approach is based on the principle of composite curves, according to the method we divide the multi-stream into sub-sections that is termed as enthalpy interval which end shows the temperature distribution. Here the designing is done for multi-stream plate and fin heat exchanger, the aim of this work is to maximize the allowable pressure of the heat exchanger. The design procedure uses a thermo-hydraulic model which equations the relation between thermo and hydraulic parameters together such as pressure drop, heat transfer coefficient, and volume of heat exchanger. We will be able to find the dimensions of heat exchanger such as width, height, length, number of passages per stream and types of fins used for each stream. Furthermore a model of MPFHE consisting of oil and water as alternating streams is shown and its results have been discussed.