Multicycle power generation thermodynamic system

TLDR: In this paper, the authors proposed a multicycle power generation thermodynamic system, where a low-boiling medium is used as a cold source for condensing water vapour, and the medium does work in a second cycle expansion unit to generate power and reduce temperature.

Abstract: The invention relates to a multicycle power generation thermodynamic system. A first cycle is an improved Rankine cycle. A low-boiling medium is used as a cold source for condensing water vapour which accomplishes work doing into water, and the source of cold energy of the low-boiling medium is that the medium does work in a second cycle expansion unit to generate power and reduce temperature. The second cycle comprises: gasification evaporation, expansion work doing and temperature reduction, driving an electric generator to generate power; and after doing work, vapour is directly turned into liquid or is turned into liquid by a compressor from the vapour state, or achieves the vapour state with minimum value of compression work; the vapour is pressurized to enter an evaporator of the second cycle, the absorbed vapour is condensed, the latent heat is vaporized, and finally the vapour enters a second medium expansion machine to do work. The water vapour in the Rankine cycle condenser, which accomplishes work doing, transfers the latent heat to a second medium and then is condensed into water. When the second cycle can not completely convert the latent heat of the water vapour which accomplishes work doing into power, a third medium is used for a third cycle; the principle thereof is identical with the second cycle, but the third medium is a substance with lower boiling point. The invention can increase the thermal efficiency of a condensing type or an extracting-and-condensing style thermal power generation system, namely the Rankine cycle.