A Low Temperature Waste Heat CO2 Rankine Cycle System

Abstract

The invention discloses a low temperature exhaust heat CO2 Rankine cycle system. According to the system, steam exhausted by steam turbines of an offshore coal-fired power station or a nuclear power station serves as a heat source, deep sea cold water or offshore cold seawater in a high latitude area serves as a cold source, CO2 serves as the working medium, and recovery and conversion of heat into power of exhaust heat of low temperature exhaust steam are achieved through the subcritical / transcritical CO2 Rankine cycle. High-pressure supercooled CO2 liquid is converted into overheated CO2 gas after absorbing heat from the heat source, the overheated CO2 gas enters a CO2 turbine to expand so as to do work, and the exhaust steam completes one cycle through condensation of the cold source and pressure boosting of a booster pump. Essentially, it is equivalent to that through the system, the temperature of the cold source of the power station is lowered to the temperature of cold seawater, but the exhaust steam flow-through area of the original power station steam turbines does not need to be increased, and thus the net output power and the generating efficiency of the coal-fired power station and the nuclear power station are improved at low cost. The low temperature exhaust heat CO2 Rankine cycle system has huge economic benefits and broad application prospects.

Description

technical field [0001] The invention relates to a low-temperature waste heat CO 2 Rankine cycle system, specifically related to a sub-(trans) critical CO 2 The Rankine cycle method belongs to the fields of mechanical engineering and low temperature waste heat recovery. Background technique [0002] At present, the thermal power conversion efficiency of large-scale coal-fired power plants using advanced technology is about 40-48%, while the efficiency of conventional pressurized water reactor nuclear power is only 30-36%, and the rest of the energy is mostly discharged through the steam turbine condenser and cooling medium. into the atmosphere, rivers and oceans, known as cold end loss, which not only wastes energy, but also causes serious thermal pollution. How to reduce the cold end loss has always been the focus of the power generation industry. [0003] Reducing the temperature of the cold source is the most effective way to reduce the loss at the cold end of the steam...

AI Technical Summary

Problems solved by technology

However, for steam turbines, the volumetric flow rate of exhaust steam increases dramatically as the condensing temperature decreases

Research shows that when the condensation temperature is 15°C, the exhaust steam volume flow rate is about 2.8 times that at 33°C. Correspondingly, the number and length of low-pressure cylinders of high-power steam turbines will also increase in the same proportion, which is technically unfeasible

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