Pump-free organic Rankine cycle power generation system with compression refrigeration efficiency

Abstract

The invention discloses a pump-free organic Rankine cycle power generation system with compression refrigeration efficiency. The system comprises a supersonic steam-liquid two-phase flow jet pump, anevaporator, an expansion machine, an evaporation condenser, an expansion pressure reduction device, a cooler, a throttling valve, a compressor and a generator which are connected with one another to form an organic Rankine cycle and a steam compression refrigeration cycle. According to the pump-free organic Rankine cycle power generation system with the compression refrigeration efficiency, the supersonic steam-liquid two-phase flow jet pump is adopted to replace a working medium pump in a conventional system, the organic Rankine cycle is coupled with the steam compression refrigeration cyclethrough the evaporation condenser, cooling capacity is provided for the organic Rankine cycle through refrigerating capacity produced by the refrigeration cycle, and the condensation temperature of exhaust gas at an outlet of the expansion machine is reduced; and meanwhile, the expansion pressure reduction device is adopted to recycle pressure energy of the high-pressure liquid working medium in aloop in the steam compression refrigeration circulation, and the irreversible loss of the side throttling process of the refrigeration cycle is reduced.

Description

technical field [0001] The invention relates to the technical field of utilization of low-grade heat energy, in particular to a pumpless organic Rankine cycle power generation system with compression refrigeration efficiency enhancement. Background technique [0002] With the increasingly tense energy supply situation, low-grade thermal power generation technology has received more and more attention, among which the organic Rankine cycle has received the most attention. Different from traditional thermal power plants, the efficiency of the organic Rankine cycle power generation system driven by low-grade heat energy is relatively low, and a large part of the electric energy produced by the system is consumed by the working fluid pump, especially for small and medium-sized organic Rankine cycle power generation systems. Since the flow rate of the working medium is generally small, the efficiency of the working medium pump is low and the power consumption accounts for a large...

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Problems solved by technology

[0003] Invention patent (ZL201410131588.4) discloses a multi-stage gravity-driven power cycle system, including a first-stage gravity-driven power cycle unit and a second-stage gravity-driven power cycle unit. Although the system realizes pump-free operation, the gravity-driven The power cycle unit has a great influence on the compactness of the system, and the height difference requirements of different working fluids are quite different, which is not conducive to system assembly and layout planning

[0004] Literature (Lu Huitong, Jiang Long, Wang Liwei, etc. The transient steady-state power generation performance of a pumpless organic Rankine cycle driven by low-temperature waste heat. Acta Chemical Industry, 2017, DOI: 10.11949 / j.issn.0438-1157.20170405) proposed a pumpless Organic Rankine cycle system, which mainly includes two heat exchangers, an expander, a generator and a four-way valve. Although the system has successfully removed the working medium pump, the two heat exchangers alternately serve as evaporators and condensers The use needs to use the four-way valve to control the flow direction of the working fluid to achieve switching, the control is cumbersome, and it is greatly affected by thermal inertia, and the system efficiency is low.

[0005] The invention patent (201410331353.X) discloses a pumpless organic Rankine power generation cycle method and device, which uses the high-temperature and high-pressure working medium steam generated by the boiler to pressurize the liquid working medium, and the liquid working medium enters the boiler by gravity, realizing Fluid is delivered from the low-pressure condenser to the high-pressure boiler, but this solution also has the problem of adjusting the flow direction of the working fluid through frequent switching of the control valve

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