Thermoeconomic assessment of a heat pump-enhanced steam and power cogeneration system under design and off-design conditions based on energy level-based exergy cost allocation method. (1st April 2020)

• Record Type: Journal Article
• Authors: Liu, Changchun; Han, Wei; Wang, Shurui; Wang, Zefeng; Zhang, Na
• Is Part Of: Energy conversion and management. Volume 209(2020)
• Publication Date: 2020-04-01
• Subjects: Thermoeconomic analysis -- Steam and power cogeneration -- ACHP -- ICE; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2020.112633
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Thermoeconomic analysis using the exergy cost allocation method based on energy levels. Steam and power cogeneration system with a high-temperature heat pump. Energy level-based thermoeconomic analysis is suitable for cogeneration systems. The electricity unit cost is more sensitive to the part load than the steam unit cost. Electricity is always costlier than steam for the investigated cogeneration systems. Abstract: Thermoeconomic analysis is considered a strong tool for cogeneration systems to optimize operation and set prices. In this paper, an absorption-compression heat pump enhanced steam and power cogeneration system is proposed, in which a heat pump is used to upgrade low-temperature waste heat and generate steam. The thermoeconomic performance of the proposed system is investigated under design and off-design conditions using a new thermoeconomic analysis approach with energy level-based cost allocation. As a result, the unit exergy costs of electricity and steam under the design conditions are 2.249 kW/kW and 1.714 kW/kW, respectively. The cost of electricity is higher than that of steam, and this result is opposite to that obtained by a conventional thermoeconomic method (2.063 kW/kW and 2.339 kW/kW, respectively). The costs of electricity and steam increase along with the decreasing engine load under off-design conditions, and the cost of electricity is always higher than that of steam. Finally, the thermoeconomic analysis method with energy level-based cost allocation can obtain more reasonable results and is more suitable for cogeneration systems.