Journal of Siberian Federal University. Engineering & Technologies / Influence of the Thermodinamic Parameters and Architecture of the Two- Stage Rankin Cycle on Its Efficiency

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Issue
Journal of Siberian Federal University. Engineering & Technologies. 2025 18 (3)
Authors
Shchinnikov, Pavel A.; Borush, Olesya V.; Luzina, Alina A.
Contact information
Shchinnikov, Pavel A. : Novosibirsk State Technical University Novosibirsk, Russian Federation; Borush, Olesya V.: Novosibirsk State Technical University Novosibirsk, Russian Federation; Luzina, Alina A.: Novosibirsk State Technical University Novosibirsk, Russian Federation;
Keywords
ORC; two-stage Rankine cycle; ORC; refrigerant; R-agent; thermal scheme; method; calculations; efficiency
Abstract

One of the directions of the development of power plants for electric power generation is the application of two- stage Rankine cycles. Two working fluids are used in them: water vapor and refrigerant. Each working fluid circulates in its circuit and does work. External energy supply from the combustion of organic fuel is realized in the steam-water Rankine cycle. The heat removed from the steam-water circuit is directed to a heat exchanger, where low-boiling working fluid steam is generated. This circuit is commonly referred to as the organic Rankine cycle (ORC). The article considers two- stage Rankine cycles of different levels of complexity using a wide range of cooling agents. It is shown that the increase in the thermal efficiency of such cycles is associated with the amount of cooling agent vapor generated by 1 kg/s of water vapor and depends on the type of working fluid. The analysis of such cycles operation was carried out depending on the initial temperature of the water vapor inlet to the steam turbine, the initial temperature of the cooling agent inlet to the ORC-turbine, and the ambient temperature. It is shown that the initial temperature of water vapor and cooling agents affects the cycle efficiency in different ways. It is demonstrated that as the thermal scheme of the two-stage cycle becomes more complex, its efficiency increases by more than 8 %. It is shown that the two-stage Rankine cycle is comparable with steam power plant for supercritical and ultra -supercritical parameters, and in-cycle fuel gasification technologies and inferior to the Allam cycle and combined cycle gas turbine unit based on promising H and HA series gas turbines

Pages
325–342
EDN
IAWZVU
Paper at repository of SibFU
https://elib.sfu-kras.ru/handle/2311/156045

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