Effect of Different Working Fluids on Shell and Tube Heat Exchanger to Recover Heat from Exhaust of An Automotive Diesel Engine

Abstract

In this research, experiments were conducted to measure the exhaust waste heat available from a 60 kW automobile engine. The performance of an available shell and tube heat exchanger using water as the working fluid was conducted. With the available data, computer simulation was carried out to improve the design of the heat exchanger. Two heat exchangers were used: one to generate saturated and the other to generate super heated vapours. These two heat exchangers can be arranged in parallel or series. In series arrangement, the exhaust gas was first passed through superheated heat exchanger and then through the saturated heat exchanger. Whereas, in parallel arrangement, the exhaust gas was divided to pass through saturated and superheated heat exchangers. In both cases, working fluid was passed first through saturated heat exchanger and then through superheated heat exchanger. Computer simulation was carried out to investigate the effectiveness of the proposed heat exchanger for different working fluid like water, ammonia, and HFC-134a. It is found that with the exhaust heat available from the diesel engine additional 15%, 13% and 8% power can be achieved by using water, HFC-134a and ammonia as working fluid respectively.