ORC (organic Rankine cycle) power generation system based on series connection of multistage evaporators

Abstract

The invention discloses an ORC power generation system based on series connection of multistage evaporators. The system comprises n evaporators , wherein the n evaporators are connected in series sequentially on a heat source side; a heat source fluid enters a first evaporator, is discharged from a last evaporator and is recharged to the underground; a working medium side of each evaporator is connected to n inlets of a steam turbine; an outlet of the steam turbine is sequentially connected with a preheater and a condenser in series; a working medium enters the preheater and the condenser, and then enters the other side of the preheater again and exchanges heat with exhaust steam exhausted by the steam turbine after working; the working medium flowing out of the preheater enters n working medium pumps in a parallel connection manner, and the n working medium pumps are connected to the n evaporators correspondingly, so that the closed cycle of the working medium is formed; a cold source side of the condenser is connected to a cooling water circulation system; a plurality of evaporator heat source sides are in series connection; and the working medium side is directly connected with the steam turbine in parallel, so that the defect that a single evaporator in a conventional ORC system is irreversible and has large loss is overcome, and the utilization efficiency and the technical economy of the system are improved.

Description

technical field

[0001] The invention belongs to the field of thermal energy engineering, and mainly relates to a thermoelectric conversion system device adopting an organic Rankine cycle mode. Background technique

[0002] The Organic Rankine cycle is a way of using organic working fluid as a thermal cycle. Geothermal energy, solar energy or other low-grade heat sources are used to heat the organic working fluid to generate steam to drive the turbogenerator to generate electricity. The temperature of the heat source fluid inlet of Organic Rankine Cycle (ORC) is usually above 80°C, and the evaporator is the part that causes the largest irreversible loss in ORC, especially when the enthalpy drop at the inlet and outlet of the heat source fluid is high. The irreversible loss of the evaporator will further increase. Therefore, multi-stage evaporators are reasonably set up to connect the heat source fluid with the evaporators at all levels, so that the liquid working medium is h...

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