Double-working-medium organic Rankine cycle power generation system and control method thereof

Abstract

The invention discloses a double-working-medium organic Rankine cycle power generation system, and belongs to the technical field of medium-low temperature heat source power generation. On the basis of a conventional organic Rankine cycle, a flash evaporation cycle which is provided with an ejector and uses a working medium with a low critical temperature is additionally arranged; the organic Rankine cycle uses a working medium with a high critical temperature, and the flash evaporation cycle uses the working medium with a low critical temperature; a circulation loop of the organic Rankine cycle is composed of a preheater, a first evaporator, a first expansion machine, a first condenser and a first working medium pump; a circulation loop of the flash evaporation cycle is composed of a second evaporator, a flash evaporation tank, a second expansion machine, an ejector, a second condenser and a second working medium pump. According to the double-working-medium organic Rankine cycle powergeneration system, the heat source at an outlet of the first evaporator is shunted and enters the preheater and the second evaporator respectively, two cycles are heated simultaneously, and the massflow of the working medium heated by the low-temperature part of the heat source is increased, so that the matching degree of the heat source is improved, the heat absorption amount of the system is increased, and the output work of the system is increased.

Description

technical field [0001] The invention belongs to the technical field of medium and low temperature heat source power generation, and in particular relates to a duplex organic Rankine cycle power generation system and a control method thereof. Background technique [0002] Organic Rankine cycle is one of the effective means to recover waste heat. Due to the linear change of the single-phase heat source and the nonlinear change of the heat absorption process of the circulating working fluid, the heat transfer narrow point of the organic Rankine cycle generally occurs at the bubble point of the working medium, resulting in a low matching degree of the system heat source and a low heat absorption. The output power is lower. Therefore, improving the heat source matching degree of the system, reducing the outlet temperature of the heat source, and increasing the heat absorption of the system can effectively increase the output work of the system. On the basis of improving the hea...

AI Technical Summary

Problems solved by technology

Due to the linear change of the single-phase heat source and the nonlinear change of the heat absorption process of the circulating working fluid, the heat transfer narrow point of the organic Rankine cycle generally occurs at the bubble point of the working medium, resulting in a low matching degree of the system heat source and a low heat absorption. low power output

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