Design and analysis of the ORC system for the engine waste heat recovery.

Number: pap. L56

Author(s) : QI Z., CHANG Y., LI Y.


Research showed that nearly 55% of the engine waste heat resources were taken away by flue gas and jacket water, which causes a great waste of energy. If these two parts of waste heat were recycled jointly, the energy efficiency of the engine would be prominently improved. Compared with other methods of waste heat recycling, organic Rankine cycle (ORC) was recognized as an effective recovery of low-grade waste heat technology because of its high thermal efficiency and simple equipment needs. Based on the working condition of a certain engine with the rated power 1000kW, three ORC configurations were designed to recycle the waste heat of engine flue gas and jacket water together in this paper, which were direct heat transfer ORC system (DHT), indirect heat transfer ORC system (IHT) and double Rankine cycles system (DRC). R245fa, R123 and water were determined as the working fluids. In DHT, the maximum net output power was 131.68kW while its heat recovery efficiency was 6.73%. This system was simple, but the security of system was reduced, and there was a risk of thermal decomposition of organic working fluids. In IHT, the maximum net output power was 131.60kW while its heat recovery efficiency was 6.73%. The power consumption increased, but the security and operability of the system improved greatly. In DRC, when the expansion ratio of water cycle was 8 and the evaporating temperature of working fluids cycle was 77?, the net output power reached the maximum 220.39kW, and its heat recovery efficiency was 11.27%, which increased by 4.54% compared to the previous two schemes, but the system was much more complex and the running cost was much higher. It was more suitable for large scale equipment.

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  • Original title: Design and analysis of the ORC system for the engine waste heat recovery.
  • Record ID : 30022071
  • Languages: English
  • Source: 8th international conference on compressors and refrigeration, 2017.
  • Publication date: 2017/07/20


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