Energy, exergy, economic (3E) analysis, optimization and comparison of different ORC based CHP systems for waste heat recovery. (December 2021)

• Record Type: Journal Article
• Authors: Teng, Shiyang; Wang, Meiwei; Xi, Huan; Wen, Shuqi
• Is Part Of: Case studies in thermal engineering. Volume 28(2021)
• Publication Date: 2021-12
• Subjects: CHP(combined heat and power) -- ORC (organic Rankine cycle) -- System optimization -- Energy analysis -- Exergy analysis -- Economic analysis; Heat engineering -- Case studies -- Periodicals; 621.40205
• DOI: 10.1016/j.csite.2021.101444
• Languages: English
• ISSNs: 2214-157X

Abstract

Abstract: ORC-CHP (combined heat and power based on organic Rankine cycle) systems have been widely adopted to recover low-grade heat. Economy, one of the advantages of ORC-CHP system, is optimized and compared in this paper. Three ORC-CHP systems are simulated and compared, including SS (serial system), the CS (the condensation system) and SS/CS (serial/condensation system). Energy-exergy-economic (3E) models for these cycles are developed, by using the genetic algorithm, the system performances are optimized with respect to the maximum profit ratio of investment (PRI). The result shows that the SS/CS has the highest PRI value under the considered working conditions. According to the results of economic analysis, the cost of the heat exchangers occupies the largest share in the three systems, all above 70%. When operated under optimal working conditions, most of the energy in the heat source is used to heat return water, leading to all three systems showing low electrical efficiency (less than 0.7%) and high thermal efficiency (more than 92%). Exergy analysis shows that most of the exergy destruction to the SS and the SS/CS occurs in hot water heaters, while for CS, it mainly occurs in the evaporator (67.48%) and then the condenser (31.35%). Graphical abstract: Image 1