Design and Analysis of Concentric Pipe Heat Exchanger for Flue Gas Heat Recovery

Abstract

Energy conservation is a worldwide concern and an important consideration for any industry. In a thermal power plant waste heat recovery from the flue gas is necessary for making the boiler more efficient. The conventional heat exchangers for the flue gas heat recovery works on the principle that the primary fluid runs through the pipe and the secondary fluid is in the surrounding shell. The required temperature of the secondary fluid is achieved by passing it over another heat exchanger. In this project the objective is to combine both stages in which the tubes are encircled by another concentric pipe and more controlled temperature of the secondary fluid is achieved by passing another hot fluid over it. Such a design is subjected to complex nature of stresses and to determine its safety the Finite Element Analysis method (FEA) has been used. A practical application is considered from a firm and from the data provided by the client a design analysis has been carried out according to the ASME codes. In this paper some cases are discussed as per the UHX rules for the worst load combination in the design to check the safety of the vessel.