Carbon dioxide energy storage system coupled with gas turbine

Abstract

The utility model provides a carbon dioxide energy storage system coupled with a gas turbine. The carbon dioxide energy storage system comprises an oxygen source switching and adjusting device, the gas turbine, a first generator, a waste heat boiler, a waste gas recovery device, a carbon dioxide storage device, a carbon dioxide gasification device, a carbon dioxide turbine, a second generator and a chimney. Compared with a traditional carbon dioxide energy storage system, the system is coupled with a gas turbine system, the occupied area needed by construction is greatly reduced, large-scale energy storage can be achieved, theoretically, large-scale energy storage and long-term energy storage time can be achieved as long as the number of carbon dioxide storage tanks is enough, and the system is not affected by any capacity, time, environment and climate; therefore, the system not only saves the construction site, but also saves the maintenance cost, and is not influenced by the capacity, time, environment and climate.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage systems, and in particular to a carbon dioxide energy storage system coupled with a combustion engine. Background Art

[0002] With the development of human industry, environmental and climate change issues have become issues of concern to the whole world. However, the power plant industry that uses fossil fuels as raw materials occupies an important position in the use of fossil fuels. At the same time, it has also become a relatively concentrated source of carbon dioxide emissions with huge emissions.

[0003] In September 2020, my country proposed at the 75th United Nations General Assembly that carbon dioxide emissions should peak before 2030 and strive to achieve carbon neutrality before 2060. Against the backdrop of the dual carbon goals, China's energy transformation mission has been very clear. However, wind power and photovoltaics are naturally intermittent and volatile, so it is difficult for renewable energy alone to completely replace traditional fossil energy installed capacity. In recent years, the installed capacity and power generation share of renewable energy such as wind power and photovoltaics have continued to increase globally, and the impact on the power system has become more and more obvious. Domestic energy storage has developed rapidly in recent years, and various new energy storage technologies are striving to break through their own shortcomings and strive to become the next mainstream energy storage method besides pumped storage. At present, electrochemical energy storage represented by lithium batteries has developed the fastest due to its high conversion efficiency, but it still has the disadvantages of high prices and safety issues that occur from time to time.

[0004] In an oxygen-enriched combustion system, carbon dioxide can be formed by circulating flue gas. How to use the oxygen-enriched combustion system to form an efficient carbon dioxide energy storage system needs to be solved urgently. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art.

[0006] To this end, the utility model provides a carbon dioxide energy storage system coupled with a combustion engine.

[0007] The utility model provides a carbon dioxide energy storage system coupled with a combustion engine, comprising:

[0008] An oxygen source switching regulating device receives a first gas source and a second gas source, wherein the first gas source includes air, and the concentration of oxygen in the second gas source is higher than that of air, and the oxygen source switching regulating device selects one of the first gas source and the second gas source to output through its output end;

[0009] A gas turbine receives a fuel source and is connected to an output end of the oxygen source switching and regulating device, wherein the output end of the gas turbine outputs exhaust gas generated during the operation of the gas turbine, wherein the exhaust gas includes at least gaseous water, carbon dioxide and oxygen; the gas turbine is used to drive a first generator to generate electricity;

[0010] A waste heat boiler is connected to the output end of the gas turbine, and the exhaust gas is output through the output end of the waste heat boiler after heat exchange in the waste heat boiler;

[0011] an exhaust gas recovery device, coupled to the output end of the waste heat boiler, and separating the gas components in the exhaust gas to output a first gaseous medium, a second gaseous medium and a third liquid medium respectively, wherein the first gaseous medium includes oxygen and carbon dioxide, the second gaseous medium includes oxygen, and the third liquid medium includes liquid carbon dioxide; wherein the second gas source is provided by at least the first gaseous medium and / or the second gaseous medium;

[0012] A carbon dioxide storage device receives and stores the third liquid medium;

[0013] A carbon dioxide gasification device, connected to the carbon dioxide storage device, to change the liquid carbon dioxide into a gaseous state and give it heat energy before outputting it through its output end;

[0014] The carbon dioxide turbine is connected to the output end of the carbon dioxide gasification device and converts the thermal energy of the carbon dioxide into kinetic energy to drive the second generator to generate electricity.

[0015] The carbon dioxide energy storage system coupled with a combustion engine according to the above technical solution of the utility model may also have the following additional technical features:

[0016] The above technical solution also includes:

[0017] The chimney is connected to the waste heat boiler through a first control valve, and is connected to the carbon dioxide turbine through a second control valve.

[0018] The above technical solution also includes:

[0019] a first oxygen source, wherein the second gas source is provided by at least one or more of a first gaseous medium, a second gaseous medium and a first oxygen source;

[0020] The first oxygen source is connected to the oxygen source switching and regulating device through a third control valve.

[0021] In the above technical solution, the carbon dioxide gasification device comprises:

[0022] a phase-change evaporation heat exchanger connected to the carbon dioxide storage device to receive liquid carbon dioxide, the phase-change evaporation heat exchanger being used to convert the liquid carbon dioxide into gaseous state and output it through its output end;

[0023] A heater is connected to the output end of the phase-change evaporation heat exchanger to receive gaseous carbon dioxide, and the heater is used to heat the gaseous carbon dioxide.

[0024] In the above technical solution, when the gas turbine uses the first gas source as the combustion-supporting gas source, the components of the exhaust gas include oxygen, carbon dioxide, nitrogen and water, and the exhaust gas is discharged through the chimney after heat exchange in the waste heat boiler;

[0025] When the gas turbine uses the second gas source as the combustion-supporting gas source, the exhaust gas comprises oxygen, carbon dioxide and water. After heat exchange in the waste heat boiler, the exhaust gas enters the exhaust gas recovery device to separate the gas components in the exhaust gas.

[0026] In the above technical solution, the pressure of the second gas source is higher than the pressure of the first gas source.

[0027] In the above technical solution, the waste gas recovery device includes:

[0028] A low-pressure compressor is connected to the output end of the waste heat boiler to receive the waste gas after heat exchange, and the low-pressure compressor compresses the waste gas after heat exchange and outputs it through the output end of the low-pressure compressor;

[0029] a first cooler connected to the output end of the low-pressure compressor, the first cooler being used to cool the compressed exhaust gas so as to liquefy at least part of the gaseous water in the compressed exhaust gas and generate a first gaseous medium;

[0030] a gas-liquid separation device, connected to the output end of the first cooler, for performing gas-liquid separation on the first gaseous medium and the liquid water, wherein the gas-liquid separation device outputs the first gaseous medium through the first output end and / or the second output end, and the gas-liquid separation device outputs the liquid water through the third output end; wherein the gas-liquid separation device provides the first gaseous medium to the second gas source through the first output end;

[0031] A high-pressure compressor connected to the second output end of the gas-liquid separation device to receive at least part of the first gaseous medium, wherein the high-pressure compressor compresses the first gaseous medium and outputs the first gaseous medium through the output end of the high-pressure compressor;

[0032] A second cooler is connected to the output end of the high-pressure compressor, and the second cooler is used to cool the compressed first gaseous medium and output it through the output end of the second cooler;

[0033] The phase change condensation heat exchanger has an input end, a first output end and a second output end. The input end of the phase change condensation heat exchanger is connected to the output end of the second cooler. The first output end of the phase change condensation heat exchanger outputs a third liquid medium. The second output end of the phase change condensation heat exchanger provides a second gaseous medium to a second gas source.

[0034] In the above technical solution, a fourth control valve is provided between the gas-liquid separation device and the oxygen source switching and regulating device;

[0035] A fifth control valve is provided between the phase-change condensing heat exchanger and the oxygen source switching and regulating device.

[0036] In the above technical solution, in the low-pressure compressor, the temperature and pressure of the waste gas after heat exchange are increased;

[0037] In the first cooler, the temperature of the compressed exhaust gas is reduced while the pressure remains unchanged, so that the gaseous water in the compressed exhaust gas is liquefied, and the oxygen and carbon dioxide in the exhaust gas are kept in a gaseous state to form the first gaseous medium.

[0038] In the above technical solution, in the high-pressure compressor, the first gaseous medium is compressed to a pressure above the critical pressure for liquefaction of carbon dioxide;

[0039] In a second cooler, the temperature of the first gaseous medium is reduced to a critical temperature for liquefaction of carbon dioxide;

[0040] In the high-pressure compressor and the second cooler, the second gaseous medium remains in a gaseous state.

[0041] In summary, due to the adoption of the above technical features, the beneficial effects of the utility model are:

[0042] Compared with the currently known carbon dioxide energy storage, this system has obvious advantages. Taking the domestic 10MW carbon dioxide energy storage verification project as an example, the required flexible gas storage volume capacity is about 7000m 3 , it occupies a large area, and the energy storage scale is subject to certain restrictions. The flexible gas warehouse is divided into two layers, the outer layer pressure needs to be maintained by the fan to ensure the storage of the inner layer low-pressure carbon dioxide, resulting in long-term operation and maintenance costs, and the flexible gas warehouse is easily affected by severe weather such as strong winds, heavy snow, and sandstorms. However, this system does not require a gas warehouse, which greatly reduces the area required for construction and can achieve large-scale energy storage. In theory, as long as there are enough carbon dioxide storage tanks, large-scale energy storage and long-term energy storage time can be achieved, which is not affected by any capacity, time, environment and climate. Therefore, this system saves construction space and maintenance costs and is not affected by capacity, time, environment and climate.

[0043] Additional aspects and advantages of the present invention will become apparent in the following description or will be understood through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0045] Figure 1It is a structural schematic diagram of a carbon dioxide energy storage system coupled with a combustion engine according to an embodiment of the utility model.

[0046] in, Figure 1 The corresponding relationship between the reference numerals and the component names is as follows:

[0047] 1. Oxygen source switching and regulating device; 2. Gas turbine; 3. First generator; 4. Waste heat boiler; 5. Carbon dioxide storage device; 6. Carbon dioxide turbine; 7. Second generator; 8. Chimney; 9. Phase change evaporation heat exchanger; 10. Heater; 11. Low pressure compressor; 12. First cooler; 13. Gas-liquid separation device; 14. High pressure compressor; 15. Second cooler; 16. Phase change condensation heat exchanger;

[0048] 101, first control valve; 102, second control valve; 103, third control valve; 104, fourth control valve; 105, fifth control valve;

[0049] 201, first gas source; 202, second gas source; 203, first oxygen source. DETAILED DESCRIPTION

[0050] In order to more clearly understand the above-mentioned purpose, features and advantages of the utility model, the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0051] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0052] Refer to the following Figure 1 To describe a carbon dioxide energy storage system coupled to a combustion engine provided according to some embodiments of the present invention.

[0053] Some embodiments of the present application provide a carbon dioxide energy storage system coupled to a combustion engine.

[0054] like Figure 1 As shown, the first embodiment of the utility model proposes a carbon dioxide energy storage system coupled with a gas turbine, including: an oxygen source switching and regulating device 1, a gas turbine 2, a first generator 3, a waste heat boiler 4, an exhaust gas recovery device, a carbon dioxide storage device 5, a carbon dioxide gasification device, a carbon dioxide turbine 6, a second generator 7 and a chimney 8.

[0055] The oxygen source switching regulating device 1 receives a first gas source 201 and a second gas source 202, wherein the first gas source 201 includes air, and the concentration of oxygen in the second gas source 202 is higher than that of air. The oxygen source switching regulating device 1 selects one of the first gas source 201 and the second gas source 202 to output through its output end.

[0056] The gas turbine 2 receives the fuel source and is connected to the output end of the oxygen source switching and regulating device 1. The output end of the gas turbine 2 outputs the exhaust gas generated during the operation of the gas turbine 2, and the exhaust gas at least includes gaseous water, carbon dioxide and oxygen; the gas turbine 2 is used to drive the first generator 3 to generate electricity. It can be understood that the first gas source 201 and the second gas source 202 both serve as the auxiliary gas source of the gas turbine 2, that is, to provide oxygen for the gas turbine 2. The fuel source used by the gas turbine 2 can be methane, hydrogen, natural gas, etc.

[0057] The waste heat boiler 4 is connected to the output end of the gas turbine 2 , and the exhaust gas is output through the output end of the waste heat boiler 4 after heat exchange in the waste heat boiler 4 .

[0058] The waste gas recovery device is coupled to the output end of the waste heat boiler 4, and separates the gas components in the waste gas to output the first gaseous medium, the second gaseous medium and the third liquid medium respectively, wherein the first gaseous medium includes oxygen and carbon dioxide, the second gaseous medium includes oxygen, and the third liquid medium includes liquid carbon dioxide; wherein the second gas source 202 is provided by at least the first gaseous medium and / or the second gaseous medium. The waste gas recovery device can adopt any one of the existing devices as long as it can produce the above-mentioned first gaseous medium, the second gaseous medium and the third liquid medium.

[0059] The carbon dioxide storage device 5 receives and stores the third liquid medium; in some embodiments, the carbon dioxide storage device 5 may be a plurality of carbon dioxide storage tanks.

[0060] The carbon dioxide gasification device is connected to the carbon dioxide storage device 5 to change the phase of liquid carbon dioxide into gaseous state and give it heat energy before outputting it through its output end.

[0061] The carbon dioxide turbine 6 is connected to the output end of the carbon dioxide gasification device to convert the thermal energy of the carbon dioxide into kinetic energy to drive the second generator 7 to generate electricity.

[0062] The chimney 8 is connected to the waste heat boiler 4 through a first control valve 101, and is connected to the carbon dioxide turbine 6 through a second control valve 102. The opening and closing of the first control valve 101 and the second control valve 102 can be determined according to the power grid absorption state, which will be specifically described in the following embodiments.

[0063] In some embodiments, the second gas source 202 is provided by at least one or more of the first gaseous medium, the second gaseous medium and the first oxygen source 203. The first oxygen source 203 is connected to the oxygen source switching and regulating device 1 through the third control valve 103. The third control valve 103 has the functions of opening and closing control and adjusting the opening, and the oxygen concentration in the gas turbine 2 is ensured to be within a suitable range by adjusting the opening. When the second gas source 202 is provided by at least two of the first gaseous medium, the second gaseous medium and the first oxygen source 203, the pressure must be increased, that is, oxygen is provided to the gas turbine 2 at a higher pressure.

[0064] In some embodiments, the carbon dioxide gasification device includes a phase change evaporation heat exchanger 9 and a heater 10 .

[0065] The phase-change evaporation heat exchanger 9 is connected to the carbon dioxide storage device 5 to receive liquid carbon dioxide. The phase-change evaporation heat exchanger 9 is used to convert the liquid carbon dioxide into gaseous state and output it through its output end.

[0066] The heater 10 is connected to the output end of the phase-change evaporation heat exchanger 9 to receive gaseous carbon dioxide. The heater 10 is used to heat the gaseous carbon dioxide, that is, to give thermal energy to the carbon dioxide therein.

[0067] Specifically, when the gas turbine 2 uses the first gas source 201 as the combustion-supporting gas source, the exhaust gas comprises oxygen, carbon dioxide, nitrogen and water, and the exhaust gas is discharged through the chimney 8 after heat exchange in the waste heat boiler 4;

[0068] When the gas turbine 2 uses the second gas source 202 as the combustion-supporting gas source, the exhaust gas comprises oxygen, carbon dioxide and water. After heat exchange in the waste heat boiler 4, the exhaust gas enters the exhaust gas recovery device to separate the gas components in the exhaust gas.

[0069] Specifically, the pressure of the second gas source 202 is higher than that of the first gas source 201 , that is, when the second gas source 202 is used as the combustion-supporting gas source, the oxygen in the gas turbine 2 can be more fully mixed with the fuel source for combustion.

[0070] In some embodiments, the exhaust gas recovery device includes: a low-pressure compressor 11, a first cooler 12, a gas-liquid separation device 13, a high-pressure compressor 14, a second cooler 15 and a phase change condensation heat exchanger 16.

[0071] The low-pressure compressor 11 is connected to the output end of the waste heat boiler 4 to receive the waste gas after heat exchange. The low-pressure compressor 11 compresses the waste gas after heat exchange and outputs it through the output end of the low-pressure compressor 11 .

[0072] The first cooler 12 is connected to the output end of the low-pressure compressor 11, and is used to cool the compressed exhaust gas to liquefy at least part of the gaseous water in the compressed exhaust gas and generate a first gaseous medium.

[0073] The gas-liquid separation device 13 is connected to the output end of the first cooler 12, and performs gas-liquid separation on the first gaseous medium and the liquid water. The gas-liquid separation device 13 outputs the first gaseous medium through the first output end and / or the second output end, and the gas-liquid separation device 13 outputs the liquid water through the third output end; wherein the gas-liquid separation device 13 provides the first gaseous medium to the second gas source 202 through the first output end.

[0074] The high-pressure compressor 14 is connected to the second output end of the gas-liquid separation device 13 to receive at least part of the first gaseous medium. The high-pressure compressor 14 compresses the first gaseous medium and outputs it through the output end of the high-pressure compressor 14 .

[0075] The second cooler 15 is connected to the output end of the high-pressure compressor 14 . The second cooler 15 is used to cool the compressed first gaseous medium and output it through the output end of the second cooler 15 .

[0076] The phase change condensation heat exchanger 16 has an input end, a first output end and a second output end. The input end of the phase change condensation heat exchanger 16 is connected to the output end of the second cooler 15. The first output end of the phase change condensation heat exchanger 16 outputs a third liquid medium. The second output end of the phase change condensation heat exchanger 16 provides a second gaseous medium to the second gas source 202.

[0077] In some embodiments, a fourth control valve 104 is provided between the gas-liquid separation device 13 and the oxygen source switching regulating device 1; a fifth control valve 105 is provided between the phase change condensing heat exchanger 16 and the oxygen source switching regulating device 1. In a specific embodiment, the fourth control valve 104 is provided between the fifth control valve 105 and the gas-liquid separation device 13.

[0078] Specifically, in the low-pressure compressor 11, the temperature and pressure of the waste gas after heat exchange are increased; in the first cooler 12, the temperature of the compressed waste gas is reduced and the pressure is unchanged, so that the gaseous water in the compressed waste gas is liquefied, and the oxygen and carbon dioxide in the waste gas are kept in gaseous state to form the first gaseous medium. In the high-pressure compressor 14, the first gaseous medium is compressed to a pressure above the critical pressure for liquefaction of carbon dioxide; in the second cooler 15, the temperature of the first gaseous medium is reduced to the critical temperature for liquefaction of carbon dioxide; in the high-pressure compressor 14 and the second cooler 15, the first gaseous medium remains in gaseous state.

[0079] In a specific embodiment, the operation process of the carbon dioxide energy storage system coupled with the combustion engine is as follows:

[0080] The combustion chamber nozzle of the gas turbine 2 is connected to the natural gas pipeline and is also connected to the oxygen source switching regulating device 1, which is simultaneously connected to the first gas source 201 and the second gas source 202. The oxygen source switching regulating device 1 can deliver the first gas source 201 or the second gas source 202 with a certain pressure and temperature to different parts of the gas turbine 2 according to the actual gas source conditions and the needs of the gas turbine 2, so as to ensure that the combustion-supporting gas source can be fully mixed and burned with the fuel source.

[0081] When the gas turbine 2 needs to run at full load, or the energy storage system is in maintenance and cannot be put into use, energy storage is not needed at this time. The gas turbine 2 system uses the air of the first gas source 201 as the combustion-supporting source. The air and natural gas are mixed and burned in the combustion chamber to drive the gas turbine 2, and generate electricity through the coaxially connected first generator 3. The exhaust gas discharged by the gas turbine 2 enters the waste heat boiler 4. After heat exchange in the waste heat boiler 4, the temperature is reduced to about 75°C. The main components of the exhaust gas discharged from the waste heat boiler 4 are oxygen (~11% Vol, Nm3), carbon dioxide (~4.5% Vol, Nm3), nitrogen (~73.5% Vol, Nm3), and gaseous water (~10.5% Vol, Nm3), which enter the chimney 8 through a pipeline and are directly discharged into the atmosphere.

[0082] When the power of the power grid is in excess, energy storage is needed to absorb the abandoned power. At this time, the second gas source 202 is used as the combustion-supporting source. At this time, the oxygen provided by the first oxygen source 203, the second gaseous medium from the phase-change condensing heat exchanger 16, and the first gaseous medium separated by the gas-liquid separation device 13 together constitute the combustion-supporting source required by the gas turbine 2. The second gas source 202 with a certain pressure and temperature is sent to different parts of the gas turbine 2 according to the needs of the gas turbine 2 through the oxygen source switching and regulating device 1 to ensure that the oxygen can be mixed evenly and the proportion of oxygen can ensure sufficient mixing and combustion with the gas. The second gas source 202 is mixed with natural gas and burned in the combustion chamber to drive the gas turbine 2, and the first generator 3 connected coaxially generates electricity. The exhaust gas discharged from the gas turbine 2 enters the waste heat boiler 4. After heat exchange in the waste heat boiler 4, the temperature is reduced to about 75°C. The main components of the exhaust gas discharged from the waste heat boiler 4 are oxygen (~11% Vol, Nm3), carbon dioxide (~79% Vol, Nm3), and H2O (~10% Vol, Nm3). The exhaust gas enters the low-pressure compressor 11 through a pipeline and is preliminarily compressed in the low-pressure compressor 11. After compression, the temperature and pressure increase. The low-pressure compressor 11 is connected to the first cooler 12. The compressed gas enters the first cooler 12. After passing through the first cooler 12, the pressure remains basically unchanged and the temperature decreases. Under the action of pressure, the gaseous water in the exhaust gas is liquefied, and the liquid water is separated and recovered by the gas-liquid separation device 13. In the gas-liquid separation device 13, the exhaust gas after dehydration contains only oxygen and carbon dioxide, that is, the first gaseous medium is formed. The first gaseous medium separated by the gas-liquid separation device 13 is sent to the oxygen source switching device through a pipeline as a combustion-supporting source; on the other hand, it is connected to the high-pressure compressor 14 and enters the high-pressure compressor 14 for further compression. The compression reaches above the critical pressure of carbon dioxide. After the compressed gas is cooled by the second cooler 15, the temperature is reduced to the critical temperature of carbon dioxide. At this time, the carbon dioxide is still in a gaseous state, and then it continues to be cooled in the phase change condensation heat exchanger 16. The gaseous carbon dioxide undergoes a phase change and liquefies in the phase change condensation heat exchanger 16, and the oxygen remains in a gaseous state, thereby achieving the separation of carbon dioxide and oxygen, that is, forming a second gaseous medium. The second gaseous medium separated in the phase change condensation heat exchanger 16 is sent to the oxygen source switching device through a pipeline as an oxygen gas source. The liquefied carbon dioxide is stored in a carbon dioxide storage tank, and the energy storage process is completed at this time.

[0083] When electricity is in short supply, it is necessary to release energy and send electricity to the grid. At this time, the liquid carbon dioxide stored in the carbon dioxide storage tank is changed from liquid to gas through the phase change evaporation heat exchanger 9, and then heated by the heater 10 to make the carbon dioxide gas in an overheated state. Then, it passes through the carbon dioxide turbine 6, driving the carbon dioxide turbine 6 to rotate and drive the second generator 7 to generate electricity, thereby realizing energy conversion. At the same time, the exhaust gas discharged by the carbon dioxide turbine 6 is discharged into the atmosphere through the chimney 8.

[0084] Specifically, two control valves are respectively arranged on the first gas source 201 pipeline and the second gas source 202 pipeline connected to the oxygen switching adjustment device, and two control valves are respectively arranged on the connecting pipelines between the outlet of the waste heat boiler 4 and the chimney 8 and the low-pressure compressor 11. The energy storage system can be switched on and off by adjusting the valve closing, and the energy storage capacity can be adjusted by adjusting the opening of the valve.

[0085] Specifically, since the oxygen of the second gaseous medium separated from the phase-change condensing heat exchanger 16 and the first gaseous medium separated from the gas-liquid separation device 13 is separated from the exhaust gas discharged from the waste heat boiler 4, it cannot meet the oxygen demand of the new cycle. A third control valve 103 is set on the pipeline from the first oxygen source 203 to the oxygen source switching device, and the required oxygen amount of the new cycle is met by adjusting the opening of the third control valve 103. In addition, by adjusting and controlling the third control valve 103, the oxygen concentration in the oxygen source entering the gas turbine 2 is controlled to achieve oxygen-enriched combustion, reduce the excess air coefficient, and keep the oxygen concentration controlled at 21-35%.

[0086] In the present disclosure, since the second gas source 202 is a gas with a certain pressure, the combustion-supporting gas source entering the combustion engine can directly enter the combustion chamber and mix with the combustion gas for combustion without compression, which can increase the power generation efficiency; in addition, the oxygen concentration can be adjusted, and the oxygen-enriched combustion of the combustion engine can be achieved by increasing the oxygen concentration, which greatly improves the performance of the combustion engine.

[0087] In conventional gas turbine power generation systems, the waste heat of flue gas at the outlet of the waste heat boiler 4 at about 70-75 degrees is directly discharged. This part of the exhaust loss accounts for a large proportion of the overall efficiency loss, resulting in energy waste. In this system, the exhaust gas at the boiler outlet is not directly discharged. It passes through the low-pressure compressor 11 and the first cooler 12. After passing through the gas-liquid separator, part of the flue gas directly returns to the gas turbine system and enters the next cycle. The first cooler 12 only cools and absorbs the heat caused by the temperature increase after compression by the low-pressure compressor 11. The temperature after passing through the first cooler 12 is still about 70°C, so that this part of energy is recycled and the heat recovery of this part of the exhaust heat is realized. This part of the recovered heat is very huge, thereby improving the overall efficiency of the gas turbine system.

[0088] Due to the particularity of the fuel of the gas turbine, the main components of the combustion products are oxygen, carbon dioxide and water. In this system, the exhaust gas at the boiler outlet is not directly discharged. The low-pressure compressor 11 and the first cooler 12 increase the pressure of the exhaust gas, thereby liquefying the water in the exhaust gas and realizing water recovery. Taking a 700MW gas turbine with 100% load as an example, the exhaust gas discharged from the waste heat boiler 4 has a flue gas volume of 3105t / h, a water volume concentration of 10.319% (Vol, Nm3), and a mass concentration of 6.58% (wt). Therefore, the water recovery per hour is 204.3t / h (3105t / hx6.58%). This part of water is relatively large, which greatly saves the consumption of water resources.

[0089] In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0090] Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this utility model should be included in the protection scope of this utility model.

Claims

1. A carbon dioxide energy storage system coupled with a gas turbine, characterized in that: include: An oxygen source switching and regulating device (1) receives a first gas source (201) and a second gas source (202), wherein the first gas source (201) includes air, and the concentration of oxygen in the second gas source (202) is higher than that in the air, and the oxygen source switching and regulating device (1) selects one of the first gas source (201) and the second gas source (202) to output through its output end; A gas turbine (2) receives a fuel source and is connected to an output end of the oxygen source switching and regulating device (1), wherein the output end of the gas turbine (2) outputs exhaust gas generated during the operation of the gas turbine (2), wherein the exhaust gas at least includes gaseous water, carbon dioxide and oxygen; the gas turbine (2) is used to drive a first generator (3) to generate electricity; A waste heat boiler (4) is connected to the output end of the gas turbine (2), and the exhaust gas is output through the output end of the waste heat boiler (4) after heat exchange in the waste heat boiler (4); an exhaust gas recovery device, coupled to the output end of the waste heat boiler (4), and separating the gas components in the exhaust gas to output a first gaseous medium, a second gaseous medium and a third liquid medium respectively, wherein the first gaseous medium comprises oxygen and carbon dioxide, the second gaseous medium comprises oxygen, and the third liquid medium comprises liquid carbon dioxide; wherein the second gas source (202) is provided by at least the first gaseous medium and / or the second gaseous medium; A carbon dioxide storage device (5) receives and stores the third liquid medium; A carbon dioxide gasification device connected to the carbon dioxide storage device (5) to change the phase of liquid carbon dioxide into gaseous state and give it heat energy before outputting it through its output end; A carbon dioxide turbine (6) is connected to the output end of the carbon dioxide gasification device and converts the thermal energy of the carbon dioxide into kinetic energy to drive a second generator (7) to generate electricity.

2. The carbon dioxide energy storage system coupled with a combustion engine according to claim 1, characterized in that: Also includes: The chimney (8) is connected to the waste heat boiler (4) via a first control valve (101), and is connected to the carbon dioxide turbine (6) via a second control valve (102).

3. The carbon dioxide energy storage system coupled with a combustion engine according to claim 1, characterized in that: Also includes: a first oxygen source (203), wherein the second gas source (202) is provided by at least one or more of a first gaseous medium, a second gaseous medium and the first oxygen source (203); The first oxygen source (203) is connected to the oxygen source switching and regulating device (1) via a third control valve (103).

4. The carbon dioxide energy storage system coupled with a combustion engine according to claim 1, characterized in that: The carbon dioxide gasification device comprises: a phase-change evaporation heat exchanger (9), connected to the carbon dioxide storage device (5) to receive liquid carbon dioxide, the phase-change evaporation heat exchanger (9) being used to convert the liquid carbon dioxide into a gaseous state and output it through its output end; A heater (10) is connected to the output end of the phase-change evaporation heat exchanger (9) to receive gaseous carbon dioxide, and the heater (10) is used to heat the gaseous carbon dioxide.

5. The carbon dioxide energy storage system coupled with a combustion engine according to claim 2, characterized in that: When the gas turbine (2) uses the first gas source (201) as a combustion-supporting source, the exhaust gas comprises oxygen, carbon dioxide, nitrogen and water, and the exhaust gas is discharged through a chimney (8) after heat exchange in a waste heat boiler (4); When the gas turbine (2) uses the second gas source (202) as a combustion-supporting source, the exhaust gas comprises oxygen, carbon dioxide and water. After heat exchange in the waste heat boiler (4), the exhaust gas enters an exhaust gas recovery device to separate gas components in the exhaust gas.

6. The carbon dioxide energy storage system coupled with a combustion engine according to claim 1, characterized in that: The pressure of the second gas source (202) is higher than the pressure of the first gas source (201).

7. The carbon dioxide energy storage system coupled with a combustion engine according to claim 1, characterized in that: The exhaust gas recovery device comprises: A low-pressure compressor (11) is connected to the output end of the waste heat boiler (4) to receive the waste gas after heat exchange, and the low-pressure compressor (11) compresses the waste gas after heat exchange and outputs it through the output end of the low-pressure compressor (11); A first cooler (12) is connected to the output end of the low-pressure compressor (11), and the first cooler (12) is used to cool the compressed exhaust gas so as to liquefy at least part of the gaseous water in the compressed exhaust gas and generate a first gaseous medium; A gas-liquid separation device (13) is connected to the output end of the first cooler (12), and performs gas-liquid separation on the first gaseous medium and liquid water. The gas-liquid separation device (13) outputs the first gaseous medium through the first output end and / or the second output end, and the gas-liquid separation device (13) outputs liquid water through the third output end; wherein the gas-liquid separation device (13) provides the first gaseous medium to the second gas source (202) through the first output end; A high-pressure compressor (14) is connected to the second output end of the gas-liquid separation device (13) to receive at least part of the first gaseous medium, and the high-pressure compressor (14) compresses the first gaseous medium and outputs it through the output end of the high-pressure compressor (14); A second cooler (15) is connected to the output end of the high-pressure compressor (14), and the second cooler (15) is used to cool the compressed first gaseous medium and output it through the output end of the second cooler (15); The phase change condensation heat exchanger (16) has an input end, a first output end and a second output end. The input end of the phase change condensation heat exchanger (16) is connected to the output end of the second cooler (15). The first output end of the phase change condensation heat exchanger (16) outputs a third liquid medium. The second output end of the phase change condensation heat exchanger (16) provides a second gaseous medium to a second gas source (202).

8. The carbon dioxide energy storage system coupled with a combustion engine according to claim 7, characterized in that: A fourth control valve (104) is provided between the gas-liquid separation device (13) and the oxygen source switching and regulating device (1); A fifth control valve (105) is provided between the phase-change condensing heat exchanger (16) and the oxygen source switching and regulating device (1).

9. The carbon dioxide energy storage system coupled with a combustion engine according to claim 7, characterized in that: In the low-pressure compressor (11), the temperature and pressure of the waste gas after heat exchange are increased; In the first cooler (12), the temperature of the compressed exhaust gas is reduced while the pressure remains unchanged, so that the gaseous water in the compressed exhaust gas is liquefied, and the oxygen and carbon dioxide in the exhaust gas are kept in a gaseous state to form the first gaseous medium.

10. The carbon dioxide energy storage system coupled with a combustion engine according to claim 7, characterized in that: In a high-pressure compressor (14), the first gaseous medium is compressed to a pressure above the critical pressure for liquefaction of carbon dioxide; In a second cooler (15), the temperature of the first gaseous medium is reduced to a critical temperature for liquefaction of carbon dioxide; In the high-pressure compressor (14) and the second cooler (15), the second gaseous medium remains in a gaseous state.

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