A clean combined cycle steam recovery and flue gas circulation system and method

Abstract

The present invention relates to the field of power generation technology, and more specifically to a clean combined cycle steam recovery and flue gas circulation system and method. The system includes a compressed air system, a gas turbine system, a generator, a heat recovery system, a water supply device, and an exhaust gas treatment system. The gas turbine system is connected to the compressed air system, the generator is connected to the gas turbine system, the heat recovery system is connected to the compressed air system and the gas turbine system, the water supply device is connected to the heat recovery system and the gas turbine system, and the exhaust gas treatment system is connected to the heat recovery system. Renewable energy electricity can be converted into chemical energy and mechanical energy for storage, thereby saving a large amount of energy. Part of the heat in the flue gas generated during power generation can also be recovered and reused. Steam cooling and flue gas circulation technology are also used to avoid energy waste, reduce carbon dioxide and pollutant emissions, and improve the environmental protection effect of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, and in particular to a clean combined cycle steam recovery and flue gas circulation system and method. Background Art

[0002] Renewable energy sources such as solar, wind, hydro, ocean, biomass, geothermal, and fuel cells are emerging green energy sources. Power plants utilizing renewable energy are rapidly expanding and developing due to their inexhaustibility, pollution-free nature, and lack of geographical constraints. Compressed air power storage systems are emerging distributed energy systems for absorbing renewable energy. These systems typically use electricity from renewable energy sources to compress air and store it as chemical and mechanical energy.

[0003] Existing compressed air energy storage technology combined with gas turbine power generation technology usually inputs compressed air into the gas turbine to participate in the combustion reaction and drive the generator to generate electricity. However, the flue gas after the combustion reaction still contains a lot of heat. Directly discharging the flue gas will cause excessive energy waste, thereby increasing energy consumption in the power generation process. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect in the prior art that directly discharging the flue gas of the gas turbine will cause excessive energy waste, thereby leading to increased energy consumption in the power generation process.

[0005] In order to solve the above problems, the present invention provides a clean combined cycle steam recovery and flue gas circulation system, comprising:

[0006] Compressed air system, suitable for compressed air;

[0007] a gas turbine system connected to the compressed air system;

[0008] a generator connected to the gas turbine system;

[0009] a heat recovery system connected to the compressed air system and the gas turbine system, adapted to recover heat from the gas turbine exhaust;

[0010] a water supply device connected to the heat recovery system and the gas turbine system, adapted to provide water to the heat recovery system, wherein a circulation loop is formed among the gas turbine system, the heat recovery system and the water supply device;

[0011] The tail gas treatment system is connected to the heat recovery system and is suitable for treating the tail gas.

[0012] Furthermore, in this clean combined cycle steam recovery and flue gas circulation system, the compressed air system includes:

[0013] a refrigerator, adapted to cool the air;

[0014] a compressor connected to the refrigerator;

[0015] A gas storage tank is connected to the compressor and the gas turbine system.

[0016] Furthermore, the clean combined cycle steam recovery and flue gas recirculation system, the gas turbine system includes:

[0017] a combustion chamber connected to the gas storage tank;

[0018] A turbine is connected to the combustion chamber and the heat recovery system.

[0019] Furthermore, the clean combined cycle steam recovery and flue gas circulation system, the heat recovery system includes:

[0020] The first heat exchanger is connected to the turbine, the combustion chamber and the water supply device, and is suitable for exchanging heat between the water and the exhaust gas. A circulation loop is formed between the water supply device, the first heat exchanger and the turbine.

[0021] Furthermore, the clean combined cycle steam recovery and flue gas circulation system, the heat recovery system also includes:

[0022] The second heat exchanger is connected to the first heat exchanger, the combustion chamber, the gas storage tank and the exhaust gas treatment system.

[0023] Furthermore, the clean combined cycle steam recovery and flue gas circulation system, the heat recovery system also includes:

[0024] The third heat exchanger is arranged between the first heat exchanger and the second heat exchanger, and the exhaust gas forms a circulation loop in the first heat exchanger, the second heat exchanger and the third heat exchanger.

[0025] Furthermore, the clean combined cycle steam recovery and flue gas circulation system, the heat recovery system also includes:

[0026] The heater is arranged between the second heat exchanger and the third heat exchanger and is suitable for heating the exhaust gas.

[0027] Furthermore, the exhaust gas treatment system of the clean combined cycle steam recovery and flue gas circulation system includes:

[0028] an absorber connected to the second heat exchanger;

[0029] A reboiler is connected to the absorber and the third heat exchanger.

[0030] The present invention also provides a clean combined cycle steam recovery and flue gas circulation method, which adopts the above-mentioned clean combined cycle steam recovery and flue gas circulation system.

[0031] Furthermore, the clean combined cycle steam recovery and flue gas recycle method comprises the following steps:

[0032] Step S1: Cooling and compressing the air in the atmosphere into compressed air through the compressed air system and then storing it;

[0033] Step S2: inputting the compressed air into the gas turbine system to participate in combustion with the fuel, so that the chemical energy of the fuel is converted into mechanical energy to drive the generator to generate electricity;

[0034] Step S3: the water supply device inputs the water into the heat recovery system, exchanges heat with the heat in the exhaust gas discharged by the gas turbine system to recover the heat, heats the water into steam, and then inputs the steam into the gas turbine system to cool the gas turbine system;

[0035] Step S4: inputting the exhaust gas after heat exchange into an exhaust gas treatment system for treatment and then discharging clean exhaust gas.

[0036] The present invention has the following advantages:

[0037] 1. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention includes a compressed air system, a gas turbine system, a generator, a heat recovery system, a water make-up device and an exhaust gas treatment system. The compressed air system is suitable for compressing air, the gas turbine system is connected to the compressed air system, the generator is connected to the gas turbine system, the heat recovery system is connected to the compressed air system and the gas turbine system, and is suitable for recovering heat in the exhaust gas of the gas turbine, the water make-up device is connected to the heat recovery system and the gas turbine system, and is suitable for providing water to the heat recovery system, a circulation loop is formed between the gas turbine system, the heat recovery system and the water make-up device, and the exhaust gas treatment system is connected to the heat recovery system and is suitable for treating the exhaust gas.

[0038] The compressed air system is driven by electricity from renewable energy to compress the air, and the compressed air is input into the gas turbine system to participate in combustion, converting chemical energy into mechanical energy and thermal energy, thereby driving the generator to generate electricity. The high-temperature flue gas after combustion is input into the heat recovery system to exchange heat with the compressed air, so that the temperature of the compressed air is increased to improve the thermal efficiency during combustion. At the same time, the water supply device inputs water into the heat recovery system to exchange heat with the flue gas. The water after heat exchange is heated to steam. Part of the steam enters the turbine of the gas turbine system as a working fluid to cool the turbine blades, and the other part of the steam is used as a working fluid to participate in the exhaust gas treatment system. The flue gas after heat exchange is treated by the exhaust gas treatment system and discharged as clean flue gas, reducing the impact and pollution on the environment.

[0039] 2. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention, the compressed air system includes a refrigerator, a compressor and an air storage tank, the refrigerator is suitable for cooling air, the compressor is connected to the refrigerator, and the air storage tank is connected to the compressor and the gas turbine system.

[0040] During the off-peak period, electricity from renewable energy is used to drive refrigerators and compressors to cool and compress the air, and store it in a gas tank. During the peak period, the compressed air in the storage tank is output to the gas turbine system to participate in power generation. In this way, the electricity during the off-peak period can be stored in the storage tank in the form of chemical energy and mechanical energy. During the peak period, the chemical energy is converted into a mechanical drive generator for peak-shaving power generation to meet the needs of the daily peak-to-valley difference in the power system load. It can also save a lot of electricity resources. The volume of the cooled compressed air is reduced, which is convenient for storage. At the same time, the cooled compressed air is higher than the temperature that liquid air needs to be cooled to. Usually, liquid air needs to be cooled to minus 173 degrees Celsius, while the cooled compressed air can meet the effect of reducing the volume at around 0 degrees Celsius.

[0041] 3. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention, the gas turbine system includes a combustion chamber connected to the gas storage tank and a turbine connected to the combustion chamber and the heat recovery system.

[0042] The steam after heat exchange in the heat recovery system provides cooling medium for the turbine. The flue gas, cooled in the third heat exchanger, is recirculated and combined with the turbine outlet flue gas through a mixer, thereby reducing the temperature of the turbine outlet flue gas (typically 600°C) to around 450°C, suitable for heating the steam in the first heat exchanger to the required temperature for cooling the turbine blades (surface temperatures can reach up to 1500°C).

[0043] The present invention provides a third heat exchanger to recycle the flue gas, thereby reducing the direct discharge of the flue gas and causing partial heat loss, saving the energy required by the gas turbine system. At the same time, the circulation of the flue gas in the first heat exchanger, the second heat exchanger and the third heat exchanger increases the concentration of carbon dioxide in the flue gas, thereby improving the treatment effect of the exhaust gas treatment system.

[0044] 4. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention, the heat recovery system also includes a third heat exchanger arranged between the first heat exchanger and the second heat exchanger, and the exhaust gas forms a circulation loop in the first heat exchanger, the second heat exchanger and the third heat exchanger.

[0045] The low-temperature flue gas (at this time, the flue gas is exhausted gas containing moisture) after heat exchange in the second heat exchanger is used to capture and recover water. The recovered water is returned to the water replenishment device and can be input into the third heat exchanger again. The heat in the flue gas can be used to heat the water into steam, and then the steam is input into the first heat exchanger for heat exchange with the high-temperature flue gas output from the turbine, thereby heating the steam into high-temperature and high-pressure steam. This arrangement reduces energy consumption in the power generation process of the gas turbine and saves energy. The water captured from the flue gas can be recycled and reused, reducing water consumption.

[0046] 5. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention, the heat recovery system also includes a heater arranged between the second heat exchanger and the third heat exchanger, suitable for heating the exhaust gas.

[0047] By setting up a heater, electricity from renewable energy can be used to provide electrical energy for the heater for heating, saving fuel consumption. The temperature of the flue gas after heating increases, which can provide higher heat exchange energy for the third air exchanger.

[0048] 6. The clean combined cycle steam recovery and flue gas circulation system provided by the present invention, the tail gas treatment system includes an absorber connected to the second heat exchanger and a reboiler connected to the absorber and the third heat exchanger.

[0049] By setting up an absorber, pollutants in the flue gas output by the second heat exchanger can be absorbed, thereby reducing harmful substances and carbon emissions. The reboiler is connected to the third heat exchanger, and the steam generated in the third heat exchanger can be input into the reboiler to provide working medium for the reboiler, fully recycling and utilizing the energy in the system's own flue gas, saving energy consumption.

[0050] 7. The clean combined cycle steam recovery and flue gas recycle method provided by the present invention comprises the following steps:

[0051] Step S1: Cooling and compressing the air in the atmosphere into compressed air through a compressed air system and then storing it;

[0052] Step S2: The compressed air is input into the gas turbine system to be burned with the fuel, so that the chemical energy of the fuel is converted into mechanical energy to drive the generator to generate electricity;

[0053] Step S3: The water supply device inputs water into the heat recovery system to exchange heat with the exhaust gas discharged by the gas turbine system to recover heat. The water is heated to steam and then input into the gas turbine system to participate in cooling the turbine blades.

[0054] Step S4: The exhaust gas after heat exchange is input into the exhaust gas treatment system for treatment and then discharged as clean exhaust gas.

[0055] Through the above steps, the electricity from renewable energy can be converted into chemical energy and mechanical energy for storage during the off-peak period or when renewable energy is abundant. When the electricity consumption is at its peak, the stored energy can be input into the gas turbine system to participate in power generation, thereby saving a lot of energy. Part of the heat in the flue gas generated during power generation can also be recovered and reused, avoiding energy waste, reducing carbon dioxide and pollutant emissions, and improving the environmental protection effect of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] Figure 1 Schematic diagram of a clean combined cycle steam recovery and flue gas circulation system provided in an embodiment of the present invention.

[0058] Description of reference numerals:

[0059] 1. Compressed air system; 11. Refrigerator; 12. Compressor; 13. Gas storage tank; 14. First pump; 2. Gas turbine system; 21. Combustion chamber; 22. Turbine; 3. Generator; 4. Heat recovery system; 41. First heat exchanger; 42. Second heat exchanger; 43. Third heat exchanger; 44. Heater; 45. Second pump; 46. Third pump; 5. Water make-up device; 51. Fourth pump; 6. Exhaust gas treatment system; 61. Absorber; 62. Reboiler. DETAILED DESCRIPTION

[0060] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0062] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0063] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0064] Example 1

[0065] like Figure 1 As shown, the clean combined cycle steam recovery and flue gas circulation system provided in this embodiment includes a compressed air system 1, a gas turbine system 2, a generator 3, a heat recovery system 4, a water supply device 5 and an exhaust gas treatment system 6. The compressed air system 1 is suitable for compressing air, the gas turbine system 2 is connected to the compressed air system 1, the generator 3 is connected to the gas turbine system 2, the heat recovery system 4 is connected to the compressed air system 1 and the gas turbine system 2, and is suitable for recovering heat in the exhaust gas of the gas turbine. The water supply device 5 is connected to the heat recovery system 4 and the gas turbine system 2, and is suitable for providing water to the heat recovery system 4. A circulation loop is formed between the gas turbine system 2, the heat recovery system 4 and the water supply device 5. The exhaust gas treatment system 6 is connected to the heat recovery system 4 and is suitable for treating the exhaust gas.

[0066] The compressed air system 1 is driven by electricity from renewable energy to compress air. The compressed air is then fed into the gas turbine system 2 for combustion, converting chemical energy into mechanical energy and thermal energy, thereby driving the generator 3 to generate electricity. Using air as a raw material has almost no usage cost. The high-temperature flue gas after combustion is fed into the heat recovery system 4 to exchange heat with the compressed air, thereby increasing the temperature of the compressed air and improving the thermal efficiency during combustion.

[0067] At the same time, the water replenishment device 5 inputs water into the heat recovery system 4 to exchange heat with the flue gas. After the heat exchange, the water is heated to steam. Part of the steam enters the gas turbine system 2 as a working medium as a cooling medium, and the other part of the steam enters the exhaust gas treatment system 6 as a working medium to provide heat. The flue gas after heat exchange is treated by the exhaust gas treatment system 6 and clean flue gas is discharged, reducing the impact and pollution on the environment.

[0068] This embodiment does not specifically limit the renewable energy power. To accommodate practical situations, the renewable energy power in this embodiment may be solar photovoltaic power generation or wind power generation. In other embodiments not shown, the renewable energy power may also be tidal power or hydropower generation.

[0069] In this embodiment, the compressed air system 1 includes a refrigerator 11, a compressor 12 and an air storage tank 13. The refrigerator 11 is suitable for cooling air. The compressor 12 is connected to the refrigerator 11. The air storage tank 13 is connected to the compressor 12 and the gas turbine system 2.

[0070] During the off-peak period, electricity from renewable energy is used to drive the refrigerator 11 and the compressor 12 to cool and compress the air, and store it in the gas storage tank 13. During the peak period, the compressed air in the storage tank is output to the gas turbine system 2 to participate in power generation. In this way, the electricity during the off-peak period can be stored in the storage tank in the form of chemical energy and mechanical energy. During the peak period, the chemical energy is converted into a mechanical drive generator 3 for peak-shaving power generation to meet the needs of the daily peak-to-valley difference in the power system load, and a large amount of electricity resources can be saved. The volume of the cooled compressed air is reduced, which is convenient for storage. At the same time, the cooled compressed air is higher than the temperature to which liquid air needs to be cooled. Usually, liquid air needs to be cooled to minus 173 degrees Celsius, while the cooled compressed air can meet the effect of reducing the volume at around 0 degrees Celsius.

[0071] The present embodiment does not specifically limit the gas storage tank 13. To conform to the actual situation, the gas storage tank 13 in the present embodiment adopts a large commercial underground gas storage container. In some other embodiments not shown, the gas storage tank 13 can also be a metal tank, etc.

[0072] In this embodiment, the gas turbine system 2 includes a combustion chamber 21 connected to the gas storage tank 13 and a turbine 22 connected to the combustion chamber 21 and the heat recovery system 4 .

[0073] The compressed air output from the air storage tank 13 is burned with the fuel in the combustion chamber 21, and the steam after heat exchange is operated in the turbine 22 to provide a cooling medium.

[0074] This embodiment does not make any specific limitations on the gas turbine system 2. To conform to actual conditions, the gas turbine system 2 in this embodiment may adopt an H / J-class heavy-duty gas turbine. The blades of the turbine 22 in this gas turbine have a high operating temperature. By introducing steam to cool the blades of the turbine 22, the exhaust waste heat of the gas turbine can be deeply absorbed.

[0075] In this embodiment, the heat recovery system 4 includes a first heat exchanger 41 connected to the turbine 22, the combustion chamber 21 and the water supply device 5, which is suitable for exchanging heat between water and exhaust gas. A circulation loop is formed between the water supply device 5, the first heat exchanger 41 and the turbine 22.

[0076] By setting up the first heat exchanger 41, part of the heat of the flue gas output by the turbine 22 can be exchanged with the water provided by the water supply device 5 in the first heat exchanger 41. After the water is heated into steam, it can participate in the cooling of the turbine 22, converting the thermal energy of the flue gas into the thermal energy of steam, thereby reducing the direct discharge of the flue gas and causing part of the heat loss, saving the energy required by the gas turbine system 2.

[0077] In this embodiment, the heat recovery system 4 further includes a second heat exchanger 42 connected to the first heat exchanger 41 , the combustion chamber 21 , the gas storage tank 13 and the exhaust gas treatment system 6 .

[0078] The flue gas after heat exchange in the first heat exchanger 41 is input into the second heat exchanger 42, and the residual heat of the flue gas after heat exchange in the first heat exchanger 41 is used to heat the low-temperature compressed air output from the gas storage tank 13. The heated compressed air is input into the combustion chamber 21 for reaction, which can increase the temperature of the compressed air when participating in combustion in the combustion chamber 21, fully recover and utilize the heat in the flue gas, and save the fuel required by the combustion chamber 21.

[0079] In this embodiment, the heat recovery system 4 further includes a third heat exchanger 43 disposed between the first heat exchanger 41 and the second heat exchanger 42 , and the exhaust gas forms a circulation loop within the first heat exchanger 41 , the second heat exchanger 42 and the third heat exchanger 43 .

[0080] The flue gas cooled in the third heat exchanger 43 is recycled and combined with the flue gas at the outlet of the turbine 22 through a mixer, thereby reducing the temperature of the flue gas at the outlet of the turbine 22 (generally 600°C) to about 450°C, which is suitable for heating the steam in the first heat exchanger 41 to the temperature required for cooling the blades of the turbine 22 (up to 1500°C).

[0081] The present invention provides a third heat exchanger 43, which can recycle the flue gas, thereby reducing the direct discharge of the flue gas and causing partial heat loss, saving the energy required by the gas turbine system 2. At the same time, the flue gas circulates in the first heat exchanger 41, the second heat exchanger 42 and the third heat exchanger 43, increasing the concentration of carbon dioxide in the flue gas and improving the treatment effect of the exhaust gas treatment system 6.

[0082] The flue gas (which is now wet exhaust steam) after heat exchange in the second heat exchanger 42 is captured and recovered, and the recovered water is transported to the water replenishment device 5 and then fed together into the third heat exchanger 43. The flue gas after heat exchange in the second heat exchanger 42 is again fed into the third heat exchanger 43, and the water in the water replenishment device 5 is fed into the third heat exchanger 43. The heat in the flue gas is used to heat the water into steam, which is then fed into the first heat exchanger 41 to exchange heat with the high-temperature flue gas output from the turbine 22, thereby heating the steam into high-temperature and high-pressure steam. This arrangement fully recycles the heat in the flue gas, saving energy and reducing energy waste. At the same time, the circulation of the flue gas within the first heat exchanger 41, the second heat exchanger 42, and the third heat exchanger 43 increases the concentration of carbon dioxide in the flue gas, thereby improving the treatment effect of the exhaust gas treatment system 6.

[0083] In this embodiment, the heat recovery system 4 further includes a heater 44 disposed between the second heat exchanger 42 and the third heat exchanger 43 , which is suitable for heating the exhaust gas.

[0084] After the flue gas heats the compressed air, its temperature and pressure will decrease. By setting up the heater 44, the electricity from renewable energy can be used to provide electrical energy for the heater 44 for heating, saving fuel consumption. The temperature and pressure of the heated flue gas increase, which can provide higher heat exchange energy for the third air exchanger.

[0085] The present embodiment does not impose any specific limitation on the heater 44. To conform to the actual situation, the heater 44 in the present embodiment adopts a fixed pore structure and is made of low-cost materials such as concrete and metal, which has a good heat storage effect.

[0086] In this embodiment, the tail gas treatment system 6 includes an absorber 61 connected to the second heat exchanger 42 and a reboiler 62 connected to the absorber 61 , wherein the reboiler 62 is connected to the third heat exchanger 43 .

[0087] By setting up the absorber 61, pollutants in the flue gas output by the second heat exchanger 42 can be absorbed, thereby reducing harmful substances and carbon emissions. The reboiler 62 is connected to the third heat exchanger 43, and the steam generated in the third heat exchanger 43 can be input into the reboiler 62 to provide energy for the operation of the reboiler 62, fully recycling and utilizing the energy in the system's own flue gas, and saving energy consumption.

[0088] This embodiment does not impose specific limitations on absorber 61. To accommodate practical needs, this embodiment employs an aqueous amine-based absorber 61 . Carbon dioxide in the flue gas is primarily absorbed by aqueous ethanolamine (MEA) within absorber 61. During absorption, the flue gas (approximately 90°C) is first cooled to approximately 50°C, then subjected to pollutant treatment to eliminate oily particles. The amine solvent absorbs CO2 (carbon dioxide) and NOx (nitrogen oxides) through a chemical reaction, forming loosely bound compounds.

[0089] This embodiment does not specifically limit the reboiler 62. To conform to the actual situation, the reboiler 62 in this embodiment adopts a solvent regeneration reboiler 62 of water-based ethanolamine. Since the reboiler 62 consumes a large amount of heat energy when working, the steam output from the third heat exchanger 43 can be used to continuously wash the reboiler 62 to separate the CO2 absorbed by the chemical solvent, and the chemical solvent can be recovered, thereby preserving the CO2 in a concentrated form.

[0090] In this embodiment, a first pump 14 is provided between the air storage tank 13 and the second heat exchanger 42. The first pump 14 controls the flow of compressed air into the second heat exchanger 42. The first pump 14 is not specifically limited in this embodiment. To accommodate practical needs, an air pump is employed as the first pump 14 in this embodiment.

[0091] In this embodiment, a second pump 45 is provided between the second heat exchanger 42 and the absorber. The second pump 45 controls the flow of heat-exchanged flue gas into the absorber 61. This embodiment does not specifically limit the second pump 45. To accommodate practical needs, an air pump is employed in this embodiment.

[0092] In this embodiment, a third pump 46 is provided between the water replenishment device 5 and the third heat exchanger 43. The third pump 46 controls the water replenishment device 5 to add water to the third heat exchanger 43. This embodiment does not impose any specific restrictions on the third pump 46. To accommodate practical situations, a water pump is employed in this embodiment.

[0093] In this embodiment, a fourth pump 51 is provided between the heater 44 and the third heat exchanger 43. The heated flue gas can be fed into the third heat exchanger 43 via the fourth pump 51. The fourth pump 51 is not specifically limited in this embodiment. To accommodate actual conditions, an air pump is used as the fourth pump 51 in this embodiment.

[0094] In this embodiment, the flue gas output from the second heat exchanger 42 is output to the heater 44 and / or the second pump 45 through the controller.

[0095] In this embodiment, the steam output from the third heat exchanger 43 is output to the first heat exchanger 41 and / or the reboiler 62 respectively through the controller.

[0096] Example 2

[0097] The clean combined cycle steam recovery and flue gas circulation method provided in this embodiment adopts the clean combined cycle steam recovery and flue gas circulation system in Example 1, and includes the following steps:

[0098] Step S1: The air in the atmosphere is cooled and compressed by the compressed air system 1 and then stored as compressed air;

[0099] Step S2: The compressed air is input into the gas turbine system 2 to be burned with the fuel, so that the chemical energy of the fuel is converted into mechanical energy to drive the generator 3 to generate electricity;

[0100] Step S3: The water supply device 5 inputs water into the heat recovery system 4, exchanges heat with the exhaust gas discharged by the gas turbine system 2 to recover heat, heats the water into steam, and then inputs the steam into the gas turbine system 2 to participate in cooling the blades of the turbine 22;

[0101] Step S4: The exhaust gas after heat exchange is input into the exhaust gas treatment system 6 for treatment and then discharged as clean exhaust gas.

[0102] Through the above steps, the electricity from renewable energy can be converted into chemical energy and mechanical energy for storage during the off-peak period or when renewable energy is abundant. When the electricity consumption is at its peak, the stored energy is input into the gas turbine system 2 to participate in power generation, thereby saving a large amount of energy. In addition, part of the heat in the flue gas generated during power generation can be recovered and reused, avoiding energy waste, reducing the emission of carbon dioxide and pollutants, and improving the environmental protection effect of the system.

[0103] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A clean combined cycle steam recovery and flue gas circulation system, characterized in that: include: A compressed air system (1) adapted to compress air using electricity from renewable energy sources; a gas turbine system (2) connected to the compressed air system (1); a generator (3) connected to the gas turbine system (2); a heat recovery system (4), connected to the compressed air system (1) and the gas turbine system (2), and adapted to recover heat from the gas turbine exhaust; a water supply device (5) connected to the heat recovery system (4) and the gas turbine system (2), and adapted to supply water to the heat recovery system (4), wherein a circulation loop is formed between the gas turbine system (2), the heat recovery system (4), and the water supply device (5); an exhaust gas treatment system (6), connected to the heat recovery system (4), and adapted to treat the exhaust gas; The compressed air system (1) comprises a refrigerator (11), a compressor (12) and an air storage tank (13); the refrigerator (11) is suitable for cooling the air; the compressor (12) is connected to the refrigerator (11); and the air storage tank (13) is connected to the compressor (12) and the gas turbine system (2); The gas turbine system (2) includes a combustion chamber (21) and a turbine (22), wherein the combustion chamber (21) is connected to the gas storage tank (13), and the turbine (22) is connected to the combustion chamber (21) and the heat recovery system (4); The heat recovery system (4) includes a first heat exchanger (41) and a second heat exchanger (42). The first heat exchanger (41) is connected to the turbine (22), the combustion chamber (21) and the water supply device (5), and is suitable for exchanging heat between the water and the exhaust gas. A circulation loop is formed between the water supply device (5), the first heat exchanger (41) and the turbine (22). The second heat exchanger (42) is connected to the first heat exchanger (41), the combustion chamber (21), the gas storage tank (13) and the exhaust gas treatment system (6).

2. The clean combined cycle steam recovery and flue gas recirculation system according to claim 1, characterized in that: The heat recovery system (4) further comprises: The third heat exchanger (43) is arranged between the first heat exchanger (41) and the second heat exchanger (42), and the exhaust gas forms a circulation loop in the first heat exchanger (41), the second heat exchanger (42) and the third heat exchanger (43).

3. The clean combined cycle steam recovery and flue gas recirculation system according to claim 2, characterized in that: The heat recovery system (4) further comprises: The heater (44) is arranged between the second heat exchanger (42) and the third heat exchanger (43) and is suitable for heating the exhaust gas.

4. The clean combined cycle steam recovery and flue gas recirculation system according to claim 2 or 3, characterized in that: The tail gas treatment system (6) comprises: an absorber (61) connected to the second heat exchanger (42); The reboiler (62) is connected to the absorber (61) and the third heat exchanger (43).

5. A clean combined cycle steam recovery and flue gas recycle method, characterized in that: A clean combined cycle steam recovery and flue gas circulation system according to any one of claims 1 to 4 is used.

6. The clean combined cycle steam recovery and flue gas recycle method according to claim 5, characterized in that: The following steps are involved: Step S1: cooling and compressing the air in the atmosphere into compressed air through the compressed air system (1) and then storing the compressed air; Step S2: inputting the compressed air into the gas turbine system (2) to participate in combustion with the fuel, so that the chemical energy of the fuel is converted into mechanical energy to drive the generator (3) to generate electricity; Step S3: the water supply device (5) inputs the water into the heat recovery system (4), exchanges heat with the heat in the exhaust gas discharged by the gas turbine system (2) to recover the heat, heats the water into steam, and then inputs the steam into the gas turbine system (2) to cool the gas turbine system (2); Step S4: the exhaust gas after heat exchange is input into the exhaust gas treatment system (6) for treatment and then discharged as clean exhaust gas.

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