A supercritical carbon dioxide cogeneration system and operation method

Abstract

The invention discloses a supercritical carbon dioxide cogeneration system and an operation method. The supercritical carbon dioxide cycle is adopted as the cogeneration power cycle, coupled with an air extraction heating system, and simultaneously provides users with two energy sources of heat and electricity; through the hot end Coupling optimization of -regeneration-heat supply process, the invention can greatly improve the energy utilization rate of the supercritical carbon dioxide power system. The system of the present invention performs reasonable energy level matching for air extraction, couples heat supply air extraction with the heat recovery system, reduces the irreversible loss of heat exchange in the system, and can meet different heat supply loads by adjusting the carbon dioxide split ratio of the heat recovery system Demand, improve the operating flexibility of the unit; also can make the system meet the heating temperature, increase the temperature of the working fluid entering the boiler, reduce the heat transfer temperature difference at the hot end, reduce irreversible losses, and improve the power generation efficiency of the unit.

Description

technical field [0001] The invention belongs to the field of cogeneration of heat and power, and in particular relates to a supercritical carbon dioxide cogeneration system and operation method. Background technique [0002] The stable growth of my country's economy is inseparable from the support of a strong energy system. my country's fossil energy structure is unbalanced, coal is the main body of my country's primary energy consumption, and coal-fired power generation is still the main power generation method in my country in a short period of time. As a large coal consumer in my country, thermal power units account for about 50% of the country's total coal consumption each year. [0003] my country's thermal power technology progress has shifted from improving initial parameters and steam reheating to full-working condition operation and deep utilization of waste heat. At the same time, central heating is carried out in the northern region to reduce pollutant emissions...

AI Technical Summary

Problems solved by technology

[0005] At present, cogeneration units in northern my country mostly use high back pressure for heating or steam turbine extraction for heating, but in supercritical carbon dioxide systems, the exhaust steam pressure of the turbine is mostly below 10MPa. The heat is slow, and when it is lower than 60°C, the heat release curve is difficult to match, and it is easy to produce large irreversible losses. The waste heat required for heating is mostly between 50°C and 140°C. The heat supply of coal power generation system is different from the traditional high back pressure heating unit. Reasonable matching of energy levels and meeting the requirements of heating temperature and load are the problems that need to be solved in supercritical carbon dioxide power cycle.

Images