Advanced exergy scrutiny (AES) of a dual-loop organic Rankine cycle for waste heat recovery of a heavy-duty stationary Diesel engine

Document Type : Original Article

Authors

1 Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran

2 Mechanical Engineering Department, Payame Noor University, Tehran, Iran

Abstract

In this paper, the normal exergy scrutiny (NES) and advanced exergy scrutiny (AES) of a waste heat recovery (WHR) system has been performed. The proposed system contains a dual-loop ORC (DORC) which recovers the available waste heat of the intake air, exhaust gas, and coolant streams of a 12-cylinder HDD engine. A well-known method of the AES called the thermodynamic cycle approach is utilized to determine each component exergy destruction parts namely exogenous/endogenous, unavoidable/avoidable, etc. Results showed that 59.04 kW from the 258.69 kW total exergy destruction rate of the system could be eliminated (22.82% of the total exergy destruction rate). The total avoidable exergy destruction part of the low-temperature loop accounts for 46.62 kW, which indicates that it requires more attention than that of the high-temperature loop by 12.42 kW. Furthermore, it is revealed that to enhance the overall productivity of the system, there is a relatively significant difference in priority order regarding the improvement of system components. The AES has proposed this ranking for improvement priority of components: condenser, expander 2, expander 1, respectively. While the NES has specified the priority as the evaporator 1, condenser, expander 2, respectively.

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