Comprehensive energy utilization system for coupling carbon capture, energy storage, and thermal power generation

1 . A comprehensive energy utilization system for coupling carbon capture, energy storage, and thermal power generation, comprising:

a thermal power generation system, comprising a coal-fired boiler unit, a steam turbine generator set, and a feedwater reheating unit;

an energy storage system, comprising a compression energy storage unit and an expansion energy release unit, wherein the compression energy storage unit is coupled to the feedwater reheating unit and configured to draw condensate water from the feedwater reheating unit to cool circulating working fluid in the compression energy storage unit and to increase a temperature of the condensate water; and the expansion energy release unit is coupled to the steam turbine generator set and configured to draw steam from the steam turbine generator set to heat circulating working fluid in the expansion energy release unit; and

a carbon capture system, coupled between the coal-fired boiler unit and the energy storage system, and configured to capture carbon dioxide gas from flue gas in the coal-fired boiler unit and input the carbon dioxide gas into the energy storage system as the circulating working fluid;

wherein the feedwater reheating unit comprises a low-pressure heater, a deaerator, and a feedwater pump sequentially connected in that order; and the compression energy storage unit is further configured to draw the condensate water from an inlet end of the low-pressure heater to cool the circulating working fluid in the compression energy storage unit and increase the temperature of the condensate water, and then convey the condensate water to an outlet end of the low-pressure heater;

wherein the energy storage system further comprises a gas storage unit and a liquid storage unit, and the carbon capture system comprises a carbon dioxide capture device, a carbon dioxide compressor, a dryer, a liquefier, and a storage container sequentially connected in that order;

wherein the carbon dioxide capture device is connected to the coal-fired boiler unit through a first connecting pipeline, the first connecting pipeline is coupled to the expansion energy release unit, and the coal-fired boiler unit is configured to heat the circulating working fluid in the expansion energy release unit by using residual heat of the flue gas;

wherein the dryer is connected to the gas storage unit through a second connecting pipeline, a pressure-reducing mechanism is disposed on the second connecting pipeline, the carbon dioxide capture device is configured to capture the carbon dioxide gas from the flue gas, the carbon dioxide compressor and the dryer are respectively configured to compress and dry the carbon dioxide gas, and the second connecting pipeline is configured to convey the carbon dioxide gas after drying to the gas storage unit;

wherein the liquefier is connected to the liquid storage unit through a third connecting pipeline, the liquefier is configured to liquefy the carbon dioxide gas from the liquid storage unit to obtain liquefied carbon dioxide, and the third connecting pipeline is configured to convey the liquefied carbon dioxide to the liquid storage unit; and

wherein the thermal power generation system further comprises a feedwater heater connected between the coal-fired boiler unit and the feedwater reheating unit, the carbon dioxide compressor is coupled to the feedwater heater, and the carbon dioxide compressor is configured to convey heat generated by the carbon dioxide compressor when compressing the carbon dioxide gas to the feedwater heater to heat boiler feedwater output from the feedwater reheating unit, and convey the boiler feedwater after heating to the coal-fired boiler unit.

2 . The comprehensive energy utilization system as claimed in claim 1 , wherein the compression energy storage unit comprises a first-stage compressor, a first-stage heat exchanger, a second-stage compressor, and a second-stage heat exchanger sequentially connected in that order; and the low-pressure heater is configured to convey the condensate water drawn from the inlet end of the low-pressure heater to the first-stage heat exchanger and the second-stage heat exchanger to cool the circulating working fluid in the first-stage heat exchanger and the second-stage heat exchanger and to increase the temperature of the condensate water.

3 . The comprehensive energy utilization system as claimed in claim 2 , wherein the compression energy storage unit further comprises: a preheater connected to an inlet end of the first-stage compressor, and a condenser connected to an outlet end of the second-stage heat exchanger.

4 . The comprehensive energy utilization system as claimed in claim 1 , wherein the steam turbine generator set comprises a steam turbine and a steam condenser connected to each other;

and the expansion energy release unit is configured to draw the steam from the steam turbine to heat the circulating working fluid in the expansion energy release unit, and convey the steam to the steam condenser.

5 . The comprehensive energy utilization system as claimed in claim 4 , wherein the expansion energy release unit comprises: a third-stage heat exchanger, a first-stage turbine, a fourth-stage heat exchanger, and a second-stage turbine sequentially connected in that order; and

wherein the steam turbine is configured to convey the steam drawn from the steam turbine to the third-stage heat exchanger and the fourth-stage heat exchanger to heat the circulating working fluid in the third-stage heat exchanger and the fourth-stage heat exchanger.

6 . The comprehensive energy utilization system as claimed in claim 5 , wherein the expansion energy release unit further comprises an evaporator connected to an inlet end of the third-stage heat exchanger, and the first connecting pipeline is coupled to the evaporator to heat the circulating working fluid in the evaporator by using the residual heat of the flue gas.