Compressed carbon dioxide energy storage power generation system coupled with gas-steam combined cycle

Abstract

The utility model relates to the field of gas power generation and the technical field of compressed carbon dioxide energy storage, in particular to a compressed carbon dioxide energy storage power generation system coupled with gas-steam combined cycle, which comprises a gas-steam combined cycle system and a compressed carbon dioxide energy storage system. The compressed carbon dioxide energy storage system comprises a low-temperature tank, the output end of the low-temperature tank is sequentially connected with a first compressor, a first heat exchanger, a second compressor, a second heat exchanger and a high-temperature tank, and the output end of the high-temperature tank is sequentially connected with a first heater, a first expansion machine, a second heater, a second expansion machine and a second condenser. The output end of the second condenser is connected with the input end of the low-temperature tank; the first expansion machine and the second expansion machine are coaxially connected with a third power generator. Exhaust smoke waste heat of the gas-steam combined cycle system is used for heating carbon dioxide, meanwhile, cooling water of the condenser is used for providing a cooling medium for the compressed carbon dioxide energy storage system, and efficient cyclic utilization of energy is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of gas power generation and the technical field of compressed carbon dioxide energy storage, in particular to a compressed carbon dioxide energy storage power generation system coupled with a gas-steam combined cycle. BACKGROUND

[0002] The demand for energy storage technology in traditional energy power generation, such as coal power industry, has gradually increased in recent years. The power generation industry needs energy storage technology to help balance power supply and demand fluctuations. When the demand for electricity is low, the power is stored, and when the demand is high, the power is released. The power grid provides flexible regulation capacity to ensure stable operation of the power grid.

[0003] Traditional compressed carbon dioxide energy storage systems usually include compression, storage, heating and expansion power generation links. During the low demand period, the system uses the remaining power to compress and store carbon dioxide. During the peak demand period, the system generates power by releasing high-pressure carbon dioxide and heating and expanding the work. However, the traditional compressed carbon dioxide energy storage system still has certain limitations in energy conversion efficiency and heat energy utilization, especially in terms of heat supply and cooling water utilization, which fails to fully realize efficient recycling of energy.

[0004] Gas-steam combined cycle (GTCC) is a highly efficient cogeneration technology that can achieve energy cascade utilization and significantly improve energy conversion efficiency through the coordinated operation of gas turbines and steam turbines. The gas-steam combined cycle system has great energy recovery potential. If it is coupled with a compressed carbon dioxide energy storage system, it can not only improve the overall efficiency of the energy storage system, but also achieve multi-stage utilization of energy and further reduce energy loss. SUMMARY

[0005] To solve the above technical problems, the utility model provides a compressed carbon dioxide energy storage power generation system coupled with a gas-steam combined cycle, which uses the exhaust heat of the gas-steam combined cycle system to heat carbon dioxide, and uses the condenser cooling water to provide cooling medium for the compressed carbon dioxide energy storage system, realizing efficient recycling of energy.

[0006] The utility model relates to a compressed carbon dioxide energy storage power generation system coupled with a gas-steam combined cycle, which comprises a gas-steam combined cycle system and a compressed carbon dioxide energy storage system.

[0007] The compressed carbon dioxide energy storage system comprises a low-temperature tank, a first compressor, a first heat exchanger, a second compressor, a second heat exchanger and a high-temperature tank connected in sequence at the output end of the low-temperature tank, a first heater, a first expander, a second heater, a second expander and a second condenser connected in sequence at the output end of the high-temperature tank, and the output end of the second condenser is connected to the input end of the low-temperature tank.

[0008] The first expander and the second expander are coaxially connected with the third generator; the first compressor and the second compressor are coaxially connected with the motor;

[0009] The first heater and the second heater are used for heating the carbon dioxide in the high-temperature tank; the first heat exchanger and the second heat exchanger are used for cooling the carbon dioxide in the low-temperature tank.

[0010] The gas-steam combined cycle system comprises a heat supply mechanism, a waste heat boiler, a first condenser, a high-pressure turbine, a low-pressure turbine, a second generator and a first heat exchanger and a second heat exchanger connected in sequence.

[0011] The exhaust gas of the heat supply mechanism provides heat for heating the carbon dioxide in the waste heat boiler.

[0012] As a preferred scheme of the utility model, the heat supply mechanism comprises a gas turbine, a combustion chamber, a compressor and a first generator, the input end of the combustion chamber is connected with air from the compressor and natural gas from the outside, the output end of the combustion chamber is connected with the gas turbine, and the exhaust gas of the gas turbine is connected with the waste heat boiler.

[0013] As a preferred scheme of the utility model, the gas-steam combined cycle system further comprises:

[0014] The output end of the high-pressure turbine is connected with the deaerator.

[0015] The system further comprises a first steam drum, a second steam drum, a first feed water pump and a second feed water pump, the output end of the deaerator comprises two paths, one path is connected with the first feed water pump, the waste heat boiler and the first steam drum in sequence, and the other path is connected with the second feed water pump, the waste heat boiler and the second steam drum in sequence.

[0016] The first steam drum is connected with the high-pressure turbine through the waste heat boiler, and the second steam drum is connected with the high-pressure turbine and the low-pressure turbine through the waste heat boiler.

[0017] The cooling water of the first heat exchanger and the second heat exchanger is connected with the inlet of the deaerator.

[0018] As a preferred scheme of the utility model, the gas-steam combined cycle system further comprises:

[0019] The system further comprises a third feed water pump, the input end of the third feed water pump is connected with the cooling water output by the first condenser, and the output end of the third feed water pump is connected with the waste heat boiler and the inlet of the deaerator in sequence.

[0020] As a preferred scheme of the utility model, the compressed carbon dioxide energy storage system further comprises:

[0021] The system further comprises a booster pump, and the output end of the high-temperature tank is connected with the first heater through the booster pump.

[0022] As a preferred scheme of the utility model, three valves are communicated between the low temperature tank and the first compressor.

[0023] As a preferred scheme of the utility model, two valves are communicated between the high pressure turbine and the oxygen remover.

[0024] As a preferred scheme of the utility model,

[0025] Compared with the prior art, the utility model has the beneficial effects that: the device is coupled through the gas steam combined cycle system and the compressed carbon dioxide energy storage system, the flue gas waste heat discharged by the gas turbine is used to heat carbon dioxide, and the condensed cooling water is used to cool carbon dioxide, realizing efficient recycling of energy, reducing investment of heat storage and cold storage equipment, optimizing system structure, improving energy utilization rate and economy, enhancing the regulation capacity of the power grid, realizing peak shaving and valley filling, reducing energy waste, and improving the reliability and overall performance of the system. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the structural schematic diagram of the utility model;

[0027] Markings in the drawings: 1, gas turbine; 2, combustion chamber; 3, compressor; 4, first generator; 5, high pressure turbine; 6, low pressure turbine; 7, first steam drum; 8, second steam drum; 9, first feed water pump; 10, second feed water pump; 11, oxygen remover; 12, first valve; 13, second valve; 14, second generator; 15, first condenser; 16, third feed water pump; 17, low temperature tank; 18, first heat exchanger; 19, second heat exchanger; 20, first heater; 21, second heater; 22, high temperature tank; 23, first expander; 24, second expander; 25, booster pump; 26, second condenser; 27, first compressor; 28, second compressor; 29, third generator; 30, motor; 31, third valve; 32, waste heat boiler. DETAILED DESCRIPTION

[0028] In order to make the above purpose, features and advantages of the utility model more apparent, obvious and easy to understand, the specific implementation of the utility model is described in detail below with the drawings of the specification.

[0029] In the following description, a lot of specific details are set forth in order to fully understand the utility model, but the utility model can also be implemented in other ways different from the description, and those skilled in the art can make similar generalization without departing from the connotation of the utility model, therefore, the utility model is not limited by the specific embodiments disclosed below.

[0030] Secondly, the term "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments.

[0031] Example

[0032] Reference Figure 1 This embodiment provides a compressed carbon dioxide energy storage power generation system coupled with a gas-steam combined cycle, including: a gas-steam combined cycle system and a compressed carbon dioxide energy storage system;

[0033] The compressed carbon dioxide energy storage system includes a cryogenic tank 17. The output end of the cryogenic tank 17 is sequentially connected to a first compressor 27, a first heat exchanger 18, a second compressor 28, a second heat exchanger 19, and a high-temperature tank 22. The output end of the high-temperature tank 22 is sequentially connected to a first heater 20, a first expander 23, a second heater 21, a second expander 24, and a second condenser 26. The output end of the second condenser 26 is connected to the input end of the cryogenic tank 17.

[0034] Expander No. 1 23 and expander No. 2 24 are coaxially connected to generator No. 3 29; compressor No. 1 27 and compressor No. 2 28 are coaxially connected to motor No. 30;

[0035] Among them, heater 20 and heater 21 are used to heat carbon dioxide in high temperature tank 22; heat exchanger 18 and heat exchanger 19 are used to cool carbon dioxide in low temperature tank 17.

[0036] The gas-fired steam combined cycle system includes a heating mechanism, a waste heat boiler 32, a first condenser 15, and a high-pressure turbine 5, a low-pressure turbine 6, and a second generator 14 connected in sequence. The output end of the low-pressure turbine 6 is cooled by the first condenser 15 and then provides cooling water to the first heat exchanger 18 and the second heat exchanger 19.

[0037] The exhaust gas from the heating system provides heat for the waste heat boiler 32 to heat carbon dioxide;

[0038] The specific working process of this device is as follows: During periods of low electricity demand or when there is surplus electricity, the motor 30 starts, driving the No. 1 compressor 27 and the No. 2 compressor 28 to run; the compressor compresses the carbon dioxide gas in the low-temperature tank 17, increasing its pressure and temperature. The compressed carbon dioxide is cooled by the No. 1 heat exchanger 18 and the No. 2 heat exchanger 19 (the cooling capacity is provided by the cooling water obtained from the output of the low-pressure turbine 6 through the No. 1 condenser 15), and then stored in the high-temperature tank 22.

[0039] When additional power is needed, the high-pressure carbon dioxide in the high-temperature tank 22 is released and heated sequentially by heaters 20 and 21. These heaters use heat from the exhaust gas from the heating system to further increase the temperature of the carbon dioxide. The heated high-pressure carbon dioxide enters the first expander 23, where it expands and does work to drive generator 29 to generate electricity, while its own pressure and temperature decrease. The carbon dioxide exiting the first expander 23 is heated again by heater 21 and enters the second expander 24 to continue expanding and doing work, further driving generator 29 to generate electricity. Finally, the carbon dioxide enters the second condenser 26 to cool and returns to the low-temperature tank 17, ready for the next cycle.

[0040] As a preferred embodiment of this utility model, the heating mechanism includes a gas turbine 1, a combustion chamber 2, a compressor 3, and a generator 4. The input end of the combustion chamber 2 is air from the compressor 3 and natural gas from the outside. The output end of the combustion chamber 2 is connected to the gas turbine 1. The exhaust gas of the gas turbine 1 is connected to the waste heat boiler 32.

[0041] The specific working process of the heating system is as follows: Fresh air from the outside is drawn into the compressor 3. After multi-stage compression, the air pressure increases significantly, and the temperature also rises. The compressed air mixes with natural gas in the combustion chamber 2 and is ignited to produce high-temperature and high-pressure gas. The high-temperature and high-pressure gas flows into the gas turbine 1, driving the turbine to rotate. While the turbine rotates, it drives the coaxial generator 4 to generate electricity. The high-temperature flue gas discharged from the gas turbine 1 contains a large amount of unused heat energy. This flue gas is introduced into the waste heat boiler 32. In the waste heat boiler 32, the heat from the flue gas is used to heat the medium, thereby further improving the efficiency of the entire system.

[0042] As a preferred embodiment of this utility model, the gas-steam combined cycle system further includes:

[0043] Deaerator 11, the output terminal of high-pressure turbine 5 is connected to deaerator 11;

[0044] It also includes: No. 1 steam drum 7, No. 2 steam drum 8, No. 1 feed water pump 9 and No. 2 feed water pump 10; the output end of the deaerator 11 includes two paths, one of which is connected to No. 1 feed water pump 9, waste heat boiler 32 and No. 1 steam drum 7 in sequence, and the other path is connected to No. 2 feed water pump 10, waste heat boiler 32 and No. 2 steam drum 8 in sequence.

[0045] Steam drum 7 is connected to high-pressure turbine 5 via waste heat boiler 32; steam drum 8 is connected to high-pressure turbine 5 and low-pressure turbine 6 via waste heat boiler 32, and its flow is controlled by valve 12.

[0046] The cooling water of heat exchanger 18 and heat exchanger 19 is connected to the inlet of deaerator 11.

[0047] Hot water discharged from high-pressure turbine 5 enters deaerator 11, which removes oxygen and other non-condensable gases from the water to prevent corrosion of downstream equipment and pipelines. The deoxygenated water from deaerator 11 is pressurized by feedwater pump 9 and then sent to waste heat boiler 32, where it absorbs heat from the flue gas of gas turbine 1 and is further heated before being sent to steam drum 7. Another portion of the deoxygenated water is pressurized by feedwater pump 10, and after being heated by waste heat boiler 32, it enters steam drum 8. Steam drums 7 and 8 receive hot water from waste heat boiler 32 and use its stored heat to convert the water into superheated steam. This steam is then returned to waste heat boiler 32 for additional heating to ensure that its temperature and pressure reach the optimal state. After being fully heated, the steam exits from steam drums 7 and 8 and is guided to high-pressure turbine 5 or low-pressure turbine 6 to drive generator 14 to rotate and generate electricity, completing a full steam cycle.

[0048] The cooling water in heat exchanger 18 and heat exchanger 19 increases in temperature after exchanging heat with the compressed carbon dioxide and flows into deaerator 11 to preheat it.

[0049] As a preferred embodiment of this utility model, the gas-steam combined cycle system further includes:

[0050] The No. 3 feedwater pump 16 has its input end connected to the cooling water output from the No. 1 condenser 15, and its output end connected in sequence to the inlet of the waste heat boiler 32 and the deaerator 11.

[0051] The cooling water output from the No. 1 condenser 15 enters the No. 3 feed water pump 16. After being pressurized by the No. 3 feed water pump 16, the condensate is then sent to the waste heat boiler 32. In the waste heat boiler 32, the condensate absorbs heat from the exhaust gas of the gas turbine 1 and its temperature rises. However, it will not be completely converted into steam at this time, but will become high-temperature hot water. The preheated water then enters the deaerator 11.

[0052] As a preferred embodiment of this utility model, the compressed carbon dioxide energy storage system further includes:

[0053] The output end of the booster pump 25 and the high-temperature tank 22 is connected to the first heater 20 through the booster pump 25;

[0054] The high-pressure carbon dioxide in the high-temperature tank 22 is first further pressurized by the booster pump 25, which ensures that the carbon dioxide has sufficient pressure to effectively pass through the subsequent heating and expansion process.

[0055] As a preferred embodiment of this utility model, a third valve 31 is connected between the cryogenic tank 17 and the first compressor 27;

[0056] The flow rate of carbon dioxide between the cryogenic tank 17 and the compressor can be adjusted by controlling the opening and closing of valve 31, thereby optimizing system operation.

[0057] As a preferred embodiment of this utility model, a second valve 13 is connected between the high-pressure turbine 5 and the deaerator 11;

[0058] The flow rate of the medium between the high-pressure turbine 5 and the deaerator 11 can be controlled by valve 13, which improves the flexibility, safety and efficiency of the system.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle, characterized in that, include: Gas-fired steam combined cycle system and compressed carbon dioxide energy storage system; The compressed carbon dioxide energy storage system includes a cryogenic tank (17). The output end of the cryogenic tank (17) is sequentially connected to a first compressor (27), a first heat exchanger (18), a second compressor (28), a second heat exchanger (19), and a high-temperature tank (22). The output end of the high-temperature tank (22) is sequentially connected to a first heater (20), a first expander (23), a second heater (21), a second expander (24), and a second condenser (26). The output end of the second condenser (26) is connected to the input end of the cryogenic tank (17). The No. 1 expander (23) and the No. 2 expander (24) are coaxially connected to the No. 3 generator (29); the No. 1 compressor (27) and the No. 2 compressor (28) are coaxially connected to the motor (30); The first heater (20) and the second heater (21) are both used to heat the carbon dioxide in the high-temperature tank (22); the first heat exchanger (18) and the second heat exchanger (19) are both used to cool the carbon dioxide in the low-temperature tank (17). The gas-steam combined cycle system includes a heating mechanism, a waste heat boiler (32), a first condenser (15), and a high-pressure turbine (5), a low-pressure turbine (6), and a second generator (14) connected in sequence. The output end of the low-pressure turbine (6) is cooled by the first condenser (15) and then provides cooling water to the first heat exchanger (18) and the second heat exchanger (19). The exhaust gas from the heating mechanism provides heat for the waste heat boiler (32) to heat carbon dioxide.

2. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 1, characterized in that, The heating mechanism includes a gas turbine (1), a combustion chamber (2), a compressor (3), and a generator (4). The input of the combustion chamber (2) is air from the compressor (3) and natural gas from the outside. The output of the combustion chamber (2) is connected to the gas turbine (1), and the exhaust gas of the gas turbine (1) is connected to the waste heat boiler (32).

3. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 2, characterized in that, The combined cycle gas-steam system also includes: Deaerator (11), the output end of the high-pressure turbine (5) is connected to the deaerator (11); It also includes: No. 1 steam drum (7), No. 2 steam drum (8), No. 1 feed water pump (9) and No. 2 feed water pump (10); the output end of the deaerator (11) includes two paths, one path is connected to the No. 1 feed water pump (9), the waste heat boiler (32) and the No. 1 steam drum (7) in sequence, and the other path is connected to the No. 2 feed water pump (10), the waste heat boiler (32) and the No. 2 steam drum (8) in sequence; The No. 1 steam drum (7) is connected to the high-pressure turbine (5) via the waste heat boiler (32); the No. 2 steam drum (8) is connected to the high-pressure turbine (5) and the low-pressure turbine (6) via the waste heat boiler (32); The cooling water of the first heat exchanger (18) and the second heat exchanger (19) is connected to the inlet of the deaerator (11).

4. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 3, characterized in that, The combined cycle gas-steam system also includes: The No. 3 feedwater pump (16) has its input end connected to the cooling water output from the No. 1 condenser (15), and its output end connected in sequence to the inlet of the waste heat boiler (32) and the deaerator (11).

5. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 1, characterized in that, The compressed carbon dioxide energy storage system also includes: The booster pump (25) is connected to the first heater (20) through the output end of the high temperature tank (22).

6. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 1, characterized in that, The cryogenic tank (17) is connected to the compressor (27) by valve (31).

7. The compressed carbon dioxide energy storage and power generation system coupled with a gas-steam combined cycle as described in claim 3, characterized in that, A second valve (13) connects the high-pressure turbine (5) and the deaerator (11).

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