CN-116517655-B - Power generation system coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage

Abstract

The power generation system comprises a compressed air waste heat energy unit, an air energy storage power generation unit and an electrolysis waste gas waste heat power generation unit, wherein one path of air is supplied to a user, the other path of air is stored after being subjected to secondary boosting and secondary cooling in the compressed air waste heat energy unit, the air energy storage power generation unit releases the stored air, the stored air is heated, generated and depressurized and then supplied to the user, the compressed air waste heat energy unit exchanges heat with the electrolysis waste gas waste heat power generation unit through cooling water, the air energy storage power generation unit absorbs organic matter heat in the electrolysis waste gas waste heat power generation unit, and the electrolysis waste gas waste heat power generation unit heats organic matters by utilizing electrolysis waste gas waste heat, and organic matter steam generates power. The invention can improve the utilization efficiency of the waste heat of the electrolytic flue gas, realize the cascade utilization of the waste heat, realize the deep peak regulation of a compressed air system of an electrolytic aluminum factory and reduce the emptying.

Inventors

• TAN PING
• ZHAO HONGWEI
• GAO PENGFEI
• LIU XIANCHEN

Assignees

• 沈阳铝镁设计研究院有限公司

Dates

Publication Date

20260512

Application Date

20230418

Claims (8)

1. 1. The power generation system is characterized by comprising a compressed air waste heat energy unit, an air energy storage power generation unit and an electrolysis flue gas waste heat power generation unit, wherein in the compressed air waste heat energy unit, air is subjected to primary boosting and primary cooling, one path is supplied to a user, the other path is subjected to secondary boosting and secondary cooling and is stored, the air energy storage power generation unit releases the stored air, is heated, generated and depressurized and is supplied to the user, the compressed air waste heat energy unit exchanges heat with the electrolysis flue gas waste heat power generation unit through cooling water, the air energy storage power generation unit absorbs organic matter heat in the electrolysis flue gas waste heat power generation unit, the electrolysis flue gas waste heat power generation unit heats organic matters by utilizing electrolysis flue gas waste heat, organic matter steam generates power, the compressed air waste heat energy unit comprises a middle-pressure air compressor (1), a No. 1 air cooler (2), a high-pressure air compressor (3), a No. 2 air cooler (4) and a high-pressure air storage tank (5), the output end of the middle-pressure air compressor (1) is connected with the No. 1 air cooler (2), the output end of the No. 1 air cooler (2) is connected with an electrolysis plant respectively, the other path is connected with the input end of a high-pressure air compressor (3), the output end of the high-pressure air compressor (3) is connected with a No. 2 air cooler (4), the output end of the No. 2 air cooler (4) is connected with a high-pressure air storage tank (5), the No. 1 air cooler (2) is connected with a No. 2 heat exchanger (16) in the electrolytic flue gas waste heat power generation unit, and the No. 2 air cooler (4) is connected with a No. 1 heat exchanger (15) in the electrolytic flue gas waste heat power generation unit.
2. 2. The power generation system for coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage according to claim 1, wherein the air energy storage power generation unit enables high-pressure air stored by the compressed air waste heat energy unit to enter an air heater (6), the output end of the air heater (6) is connected with the input end of an air turbine (7), the air turbine (7) is connected with a No. 1 generator (8), the air outlet of the air turbine (7) is connected with the output end of a No. 1 air cooler (2), and the air heater (6) is connected with a cooler in the electrolysis flue gas waste heat power generation unit.
3. 3. The power generation system for coupling the electrolytic flue gas waste heat, the compressed air waste heat and the air energy storage according to claim 1 is characterized in that the electrolytic flue gas waste heat power generation unit comprises an organic matter evaporator (9), the organic matter evaporator (9) is connected with the input end of an organic matter turbine (10), the organic matter turbine (10) is connected with a No. 2 generator (11), an organic matter outlet of the organic matter turbine (10) is connected with an air heater of the air energy storage power generation unit, a tube side outlet of the air heater of the air energy storage power generation unit is connected with an organic matter condenser (12), the organic matter condenser (12) is connected with an organic matter storage tank (13), the organic matter storage tank (13) is connected with an organic matter pump (14), the organic matter pump (14) is connected with a No. 1 heat exchanger (15), the No. 1 heat exchanger (15) is connected with a No. 2 heat exchanger (16), and the No. 2 heat exchanger (16) is connected with the organic matter evaporator (9).
4. 4. The power generation system for coupling the waste heat of the electrolytic flue gas, the waste heat of the compressed air and the air energy storage according to claim 3 is characterized in that the electrolytic flue gas of the power generation unit of the waste heat of the electrolytic flue gas is from an electrolytic tank, the electrolytic flue gas enters an organic matter evaporator (9), a bypass pipeline is arranged in the electrolytic flue gas, a flue gas outlet of the organic matter evaporator (9) is connected with a fan (19), and the fan (19) is connected with a chimney (20).
5. 5. The power generation system for coupling the waste heat of the electrolytic flue gas, the waste heat of the compressed air and the air energy storage according to claim 1, wherein the No.1 air cooler (2) and the No. 2 air cooler (4) are provided with bypasses communicated with external circulating water.
6. 6. The power generation system for coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage according to claim 4, wherein the organic matter evaporator (9) is provided with a flue gas bypass system.
7. 7. The power generation system for coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage according to claim 3, wherein the organic matter evaporator (9) is provided with an organic matter tube pass, the flue gas passes through a shell pass, the flue gas organic matter is changed into organic matter steam in the organic matter evaporator (9), the pressure is 1.0MPa, and the pressure is reduced to 0.15MPa after the organic matter turbine (10) does work.
8. 8. The power generation system for coupling the electrolytic flue gas waste heat, the compressed air waste heat and the air energy storage according to claim 1, wherein the cooling medium of the No. 1 air cooler (2) and the cooling medium of the No. 2 air cooler (4) are circulating water, the circulating water is communicated with a No. 2 heat exchanger (16) of the No. 1 air cooler (2) and the electrolytic flue gas waste heat power generation unit, and the No. 2 air cooler (4) and a No. 1 heat exchanger (15) of the electrolytic flue gas waste heat power generation unit.

Description

Power generation system coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage Technical Field The invention belongs to the technical field of waste heat utilization, and particularly relates to a power generation system for coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage. Background The electrolytic aluminum factory is a large household of compressed air, taking 50 ten thousand tons of electrolytic aluminum factory as an example, the consumption of the compressed air reaches 1200Nm 3/min, and the electrolytic aluminum factory is mainly used in the working sections of electrolytic tank crust breaking and blanking, electrolytic flue gas desulfurization, dust collection and the like, and the compressed air is characterized by large load fluctuation, low load of the compressed air at night, high load of the compressed air at daytime and the phenomenon of compressed air emptying at night. Compression heat generated in the compression process of the air compressor is sent to the cooling tower through the cooling water and is emitted to the atmosphere, and the two conditions cause great waste of energy. The aluminum electrolysis flue gas takes carbon dioxide as a main component and fluoride, sulfur dioxide and dust as main pollutants. The temperature of the flue gas at the outlet of the electrolytic tank is generally 110-140 ℃, and a large amount of heat energy is dissipated into the air along with the discharge of the electrolytic flue gas. At present, a heat exchanger is mainly arranged for the waste heat utilization of the electrolysis flue gas, the recovered heat is used for heating and bathing, and the heat is not fully utilized. Disclosure of Invention In view of the defects and shortcomings of the prior art, the invention provides a power generation system for coupling electrolysis flue gas waste heat, compressed air waste heat and air energy storage, which can improve the utilization efficiency of the electrolysis flue gas waste heat, realize cascade utilization of the waste heat by matching with the waste heat energy of an air compressor, and realize deep peak regulation of a compressed air system of an electrolytic aluminum plant by utilizing the compressed air energy storage, so that the air discharge is reduced. In order to achieve the above purpose, the main technical scheme adopted by the invention comprises the following steps: The power generation system comprises a compressed air waste heat energy unit, an air energy storage power generation unit and an electrolysis flue gas waste heat power generation unit, wherein air in the compressed air waste heat energy unit is subjected to primary boosting, primary cooling, one path of air is supplied to a user, the other path of air is subjected to secondary boosting and secondary cooling and then stored, the air energy storage power generation unit releases the stored air, the stored air is heated, generated and depressurized and then supplied to the user, the compressed air waste heat energy unit exchanges heat with the electrolysis flue gas waste heat power generation unit through cooling water, the air energy storage power generation unit absorbs organic matter heat in the electrolysis flue gas waste heat power generation unit, and the electrolysis flue gas waste heat power generation unit utilizes electrolysis flue gas waste heat to heat organic matters, and organic matter steam is used for power generation. The compressed air waste heat energy unit comprises a medium-pressure air compressor, a No. 1 air cooler, a high-pressure air compressor, a No. 2 air cooler and a high-pressure air storage tank, wherein the output end of the medium-pressure air compressor is connected with the No. 1 air cooler, the output end of the No. 1 air cooler is divided into two paths, one path is connected with a user of an electrolytic aluminum factory, the other path is connected with the input end of the high-pressure air compressor, the output end of the high-pressure air compressor is connected with the No. 2 air cooler, the output end of the No. 2 air cooler is connected with the high-pressure air storage tank, the No. 1 air cooler is connected with a heat exchanger in the electrolytic flue gas waste heat generation unit, and the No. 2 air cooler is connected with the heat exchanger in the electrolytic flue gas waste heat generation unit. Further, the air energy storage power generation unit enables high-pressure air stored by the compressed air waste heat energy unit to enter the air heater, the output end of the air heater is connected with the input end of the air turbine, the air turbine is connected with the No. 1 generator, the air outlet of the air turbine is connected with the output end of the No. 1 air cooler, and the air heater is connected with the cooler in the electrolytic flue gas waste heat power generation unit. The electrolytic flue gas waste heat power generation unit