Wide-load and low-carbon gas combined heat and power generation and solid waste utilization coupling system

Abstract

The invention discloses a wide-load and low-carbon gas combined heat and power generation and solid waste utilization coupling system which comprises a gas turbine power generation unit, a combined heat and power generation unit, a solid waste pyrolysis and gasification unit and a heat storage device. High-temperature flue gas of the gas turbine power generation unit is connected into the combined heat and power generation unit, a plurality of steam turbines in the combined heat and power generation unit are matched with a steam turbine generator to supply power to the outside of a plant, and the steam turbines are connected with a heat supply steam main pipe and communicated with the outside of the plant and a heat storage device through the heat supply steam main pipe to conduct heat transmission. The solid waste pyrolysis and gasification unit provides synthesis gas for the gas turbine power generation unit and the combined heat and power generation unit after treating input solid waste and communicates with the heat storage device for heat transmission. The operation flexibility can be improved, after the steam turbine stops working, the heat supply mother pipe can be used for conducting heat preservation on the stopped steam turbine so that the stopped steam turbine can be in a warm state, and the starting time is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of gas cogeneration, and in particular to a wide-load and low-carbon gas cogeneration and solid waste utilization coupling system. Background Art

[0002] In the current context, natural gas-fired combined cycle (GC) units offer the advantages of clean, low-carbon operation, high energy efficiency, and rapid load regulation. To improve system efficiency and economic benefits, many GC units operate as combined heat and power (CHP), also known as gas-fired combined heat and power (CHP) units. In this scenario, there is a strong thermal-electric coupling and limiting relationship between the unit's power and heat output. Furthermore, due to the turbine's minimum flow rate, the unit has a minimum load limit, ultimately resulting in a narrow operating load range and weak peak-shaving capability for CHP units.

[0003] In a new energy mix characterized by a growing use of renewable energy, gas-fired combined heat and power (CHP) units have a very limited role in peak-shaving and lack flexibility. For example, the maximum extraction steam capacity of an extraction-condensing steam turbine is approximately 75% of the main steam capacity. During moderate heating loads, the gas turbine must be maintained at a relatively high load. During periods of low grid demand, the unit is unable to reduce its load. This places increased pressure on other peak-shaving energy storage facilities. For example, a 6F.03 combined cycle CHP unit, operating in a one-to-one configuration, has a gas turbine power of 80 MW at rated load and a main steam flow of 120 t / h. In pure condensing mode, the turbine power is 41 MW. In CHP mode, the maximum extraction steam capacity is 90 t / h, corresponding to a turbine power of 21 MW. When the gas turbine load is reduced to 50%, the main steam flow is 60 t / h, and due to flow restrictions, the maximum extraction steam capacity is 29.8 t / h, resulting in a total power of 57 MW. This means that when the power is below 57 MW, the steam supply cannot exceed 30 t / h; conversely, when the steam supply exceeds 30 t / h, the total power cannot fall below 57 MW. This demonstrates the strong constraint between power supply and heat supply loads. Furthermore, current combined cycles generally employ a "one-to-one" configuration, with one gas turbine paired with one steam turbine, or a "multiple-to-one" configuration, with multiple gas turbines paired with one steam turbine. This operating mode is advantageous in stable operation scenarios, but it lacks flexibility in scenarios where renewable energy fluctuates and thermal power is coordinated for regulation and support.

[0004] In gas-fired combined heat and power (CHP) units, while gas turbines offer rapid start-up and shutdown capabilities and low-load operation, steam turbines, due to limitations such as metal materials, structural design, and thermal inertia, experience slow cold starts, several times longer than warm and hot starts. This results in the combined cycle unit's peak-shaving capacity relying primarily on the gas turbine, making it difficult to fully utilize the steam turbine's peak-shaving capacity. Maintaining the steam turbine in hot standby mode can accelerate start-up and shutdown speeds and enhance the CHP unit's peak-shaving capability.

[0005] Therefore, there is an urgent need for a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system to solve the problem of slow startup caused by cold steam turbines in common gas-steam combined cycle units. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system to solve the problem of slow startup caused by a cold steam turbine in a common gas-steam combined cycle unit.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system comprises a gas turbine power generation unit, a cogeneration unit, a solid waste pyrolysis and gasification unit and a heat storage device. The gas turbine power generation unit is used to access fuel gas and supply power to the outside of the plant and the solid waste pyrolysis and gasification unit separately or simultaneously. The high-temperature flue gas produced by the gas turbine power generation unit is connected to the cogeneration unit, and several steam turbines in the cogeneration unit cooperate with the steam turbine generator to supply power to the outside of the plant. The several steam turbines are also respectively connected to a heating steam main pipe, and are connected to the outside of the plant and the heat storage device through the heating steam main pipe for heat transfer. The solid waste pyrolysis and gasification unit is used to provide synthetic gas as fuel to the gas turbine power generation unit and the cogeneration unit respectively after processing the input solid waste, and is connected to the heat storage device for heat transfer.

[0008] To optimize the above technical solutions, specific measures taken also include: Furthermore, the gas turbine power generation unit includes a gas turbine and a gas turbine generator. The compression part of the gas turbine is connected to the air, and the combustion chamber of the gas turbine is connected to the natural gas and the synthetic gas provided by the solid waste pyrolysis gasification unit. The output end of the gas turbine is connected to the gas turbine generator through a shaft. The gas turbine generator is used to supply power to the outside of the factory and the solid waste pyrolysis gasification unit. The high-temperature flue gas produced by the gas turbine is connected to the cogeneration unit.

[0009] Furthermore, the cogeneration unit includes a supplementary burning waste heat boiler, several steam turbines, several steam turbine generators, a condenser and a circulating pump. The steam turbine includes a steam turbine A and a steam turbine B, and the steam turbine generator includes a steam turbine generator A and a steam turbine generator B. The supplementary burning waste heat boiler is connected to the high-temperature flue gas produced by the gas turbine power generation unit and the synthetic gas provided by the solid waste pyrolysis gasification unit as an auxiliary fuel. The water vapor generated by the supplementary burning waste heat boiler enters the steam turbine A and the steam turbine B simultaneously or separately. The steam turbine A and the steam turbine B are respectively connected to the steam turbine generator A and the steam turbine generator B, and the steam turbine generator A and the steam turbine generator B supply power to the outside of the plant. The steam turbine A and the steam turbine B are also respectively connected to the heating steam main pipe, and are connected to the outside of the plant and the heat storage device through the heating steam main pipe for heat transfer. The steam turbine A and the steam turbine B are also connected to the condenser and the circulating pump in sequence. The circulating pump is used to replenish water and then connect to the supplementary burning waste heat boiler.

[0010] Furthermore, valves b and valve c are respectively provided on the pipes connecting the supplementary-fired waste heat boiler to the steam turbine A and the steam turbine B, and valves d and valve e are respectively provided on the pipes connecting the steam turbine A and the steam turbine B to the heating steam main pipe.

[0011] Furthermore, the solid waste pyrolysis and gasification unit includes a feeder, a drying preheater, a gasifier, an oxygen-enriched production and storage unit, a particulate matter collector, a high-temperature heat exchanger, a low-temperature heat exchanger, an impurity gas removal device and a decarbonized synthesis gas high and low storage unit. The feeder is used to transport the solid waste to the drying preheater, and the dried solid waste is transported from the drying preheater to the gasifier. The oxygen-enriched production and storage unit is used to supply oxygen to the gasifier. The gasifier is powered by a gas turbine power generation unit and outputs high-temperature flue gas to the particulate matter collector. After the high-temperature flue gas is dusted by the particulate matter collector, it is input into the high-temperature heat exchanger and stored in the heat storage device by the high-temperature heat exchanger, and then transported to the low-temperature heat exchanger. The low-temperature heat exchanger is used to supply hot gas to the gasifier and the drying preheater, and then transported to the impurity gas removal device. The impurity gas removal device is used to provide synthesis gas to the gas turbine power generation unit and the cogeneration unit respectively. The heat storage device is also connected to the drying preheater for heat supply.

[0012] Furthermore, a valve n is provided on the pipe connecting the low-temperature heat exchanger and the dry preheater, and a valve o is provided on the pipe connecting the heat storage device and the dry preheater.

[0013] Furthermore, the oxygen-enriched production and storage unit includes an air separation unit and an oxygen-enriched storage device. The air separation unit is powered by a gas turbine power generation unit and is directly connected to the gasifier through a pipeline for supplying air to the gasifier. A valve g is installed on the pipeline connecting the air separation unit and the gasifier; the air separation unit is also connected to the oxygen-enriched storage device through a pipeline, and a valve h is installed on the pipeline between the air separation unit and the oxygen-enriched storage device. The oxygen-enriched storage device is connected to the gasifier through a pipeline, and a valve i is installed on the pipeline between the oxygen-enriched storage device and the gasifier.

[0014] Furthermore, a power regulator a is provided on the circuit connecting the gas turbine power generation unit to the gasifier, and a power regulator b is provided on the circuit connecting the gas turbine power generation unit to the air separation device.

[0015] Furthermore, the decarbonized synthesis gas high and low storage unit includes a high-pressure gas storage tank and a low-pressure gas storage tank. The impurity gas removal device is used to supply synthesis gas to the high-pressure gas storage tank and the low-pressure gas storage tank respectively after removing the acid gas. The high-pressure gas storage tank is used to supply synthesis gas to the gas turbine power generation unit, and the low-pressure gas storage tank is used to supply synthesis gas to the cogeneration unit.

[0016] Furthermore, a valve j is provided on the pipeline connecting the impurity gas removal device and the high-pressure gas storage tank, a valve k is provided on the pipeline connecting the high-pressure gas storage tank and the gas turbine power generation unit, a valve l is provided on the pipeline connecting the impurity gas removal device and the low-pressure gas storage tank, and a valve m is provided on the pipeline connecting the low-pressure gas storage tank and the cogeneration unit.

[0017] The beneficial effects of the present invention are: The present invention, through the arrangement of a gas turbine power generation unit, a cogeneration unit, a solid waste pyrolysis gasification unit, and a heat storage device, forms a gas-steam combined cycle consisting of a gas turbine power generation unit and a cogeneration unit, and the solid waste gasification and heat storage devices are coupled and coordinated to achieve flexible thermal-electric decoupling, wide-load operation, and rapid regulation. By combining the stopping and running of multiple steam turbines, the load range of power supply and heat supply is broadened, and thermal-electric decoupling is achieved to a certain extent. When the gas turbine power generation unit is at low load, the heating capacity is significantly increased. Under a specific load, after a steam turbine stops working, the steam from the heating main pipe is used to keep the stopped steam turbine warm, so that the steam turbine is in a warm state, thereby significantly shortening the start-up time of the steam turbine, shortening the response speed, and reducing the carbon emission intensity of power supply and heat supply. The decarbonized synthesis gas produced by the solid waste pyrolysis gasification unit can achieve partial natural gas substitution and significantly reduce the carbon emission intensity of power generation and heat supply.

[0018] By implementing a one-to-many scheme, the present invention can realize steam extraction heating under the lowest load of the gas turbine in the gas-steam combined cycle part, and can effectively increase the steam extraction heating capacity within the low load range.

[0019] The present invention can significantly increase the thermal power output of the supplementary-fired waste heat boiler by supplementary-fired synthesis gas in the supplementary-fired waste heat boiler, ultimately increasing the external heat supply by 1.5 times that of the non-supplementary-fired working condition, and can further reduce the carbon emission intensity of heat and electricity.

[0020] The present invention greatly improves the corresponding speed of power supply and heat supply. In the electric heating gasification mode, the response of electric power can appear a step response. The steam turbine is in a warm state, the start-up time is shortened by about 30%, and the response speed and amplitude far exceed the traditional gas turbine adjustment.

[0021] The gasifier of the present invention can utilize a device with two heating modes: electric heating and oxygen-enriched self-heating. When the generated power exceeds the grid demand, the gasifier operates in electric heating mode, which can quickly and significantly absorb the surplus power. When the generated power is less than or equal to the grid demand, the gasifier operates in oxygen-enriched self-heating mode, which can quickly and significantly stop power consumption, thereby increasing the power supply capacity to the grid. Either mode can be selected for operation, or they can be used simultaneously. At the maximum blending ratio, the corresponding electric heating power is approximately 4.5% of the gas turbine's rated output, which can assist in achieving rapid regulation within ±9%.

[0022] The present invention can realize flexible operation with a wide load range and achieve thermal and electrical decoupling to a certain extent, thus breaking through the thermal and electrical constraints of conventional gas combined cycle cogeneration. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system proposed by the present invention; Figure 2 This is a control method flow of a wide-load and low-carbon gas cogeneration and solid waste utilization coupling system proposed by the present invention Figure 1 ; Figure 3 This is a control method flow of a wide-load and low-carbon gas cogeneration and solid waste utilization coupling system proposed by the present invention Figure 2 ; Figure 4 This is a control method flow of a wide-load and low-carbon gas cogeneration and solid waste utilization coupling system proposed by the present invention Figure 3 ; Figure 5 This is a control method flow of a wide-load and low-carbon gas cogeneration and solid waste utilization coupling system proposed by the present invention Figure 4 ; Figure 6 This is a structural schematic diagram of a gasifier of a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system proposed by the present invention.

[0024] Reference numerals: 1. Gas turbine, 2. Gas turbine generator, 3. Supplementary combustion waste heat boiler, 4. Steam turbine A, 5. Steam turbine B, 6. Steam turbine generator A, 7. Steam turbine generator B, 8. Condenser, 9. Circulating pump, 10. Air separation unit, 11. Oxygen-enriched storage device, 12. Drying preheater, 13. Gasifier, 131. Feed inlet, 132. Gasification medium gas nozzle, 133. Grate, 134. Slag storage area, 135. Slag discharger, 136. Slag discharge port, 137. Electric heating element, 138. Oxygen-enriched nozzle, 139. Synthesis gas outlet, 14. Particulate matter collector, 15. High High-temperature heat exchanger, 16. Low-temperature heat exchanger, 17. Impurity gas removal device, 18. High-pressure gas storage tank, 19. Low-pressure gas storage tank, 20. Heat storage device, 21. Temperature and pressure reduction device; 1-1. Valve a, 1-2. Power regulator a, 1-3. Power regulator b, 2-1. Valve b, 2-2. Valve c, 2-3. Valve d, 2-4. Valve e, 2-5. Valve f, 3-1. Valve g, 3-2. Valve h, 3-3. Valve i, 3-4. Valve j, 3-5. Valve k, 3-6. Valve l, 3-7. Valve m, 4-1. Valve n, 4-2. Valve o. DETAILED DESCRIPTION

[0025] The present invention will now be described in further detail with reference to the accompanying drawings.

[0026] As attached Figure 1 As shown, a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system includes a gas turbine power generation unit, a cogeneration unit, a solid waste pyrolysis and gasification unit and a heat storage device 20. The gas turbine power generation unit is used to access fuel gas and selectively supply power to the outside of the plant and the solid waste pyrolysis and gasification unit, such as supplying power separately or simultaneously. The high-temperature flue gas produced by the gas turbine power generation unit is connected to the cogeneration unit, and several steam turbines in the cogeneration unit cooperate with the steam turbine generator to supply power to the outside of the plant. The steam turbines are also connected to the heating steam main pipe respectively, and are connected to the outside of the plant and the heat storage device 20 through the heating steam main pipe for heat transfer. The solid waste pyrolysis and gasification unit is used to provide synthetic gas as fuel to the gas turbine power generation unit and the cogeneration unit respectively after processing the input solid waste, and is connected to the heat storage device 20 for heat transfer.

[0027] The present invention comprises a gas turbine power generation unit, a cogeneration unit, a solid waste pyrolysis and gasification unit and a heat storage device 20, and a gas-steam combined cycle is formed by the gas turbine power generation unit and the cogeneration unit. The solid waste gasification and the heat storage device 20 are coupled and coordinated to realize flexible thermal-electrical decoupling and rapid wide load peak regulation. It can significantly increase the heating capacity when the gas turbine power generation unit is under low load, realize thermal-electrical decoupling, and improve the flexibility of the combined cycle operation. The decarbonized synthesis gas is produced by the solid waste pyrolysis and gasification unit, which can realize partial natural gas substitution and significantly reduce the carbon emission intensity of power generation and heating. Under a specific load, after a steam turbine stops working, the steam from the heating main pipe is used to keep the stopped steam turbine hot, so that the steam turbine is in a warm state, thereby greatly shortening the start-up time of the steam turbine and shortening the response speed.

[0028] In the above scheme, valves f2-5 for regulation can be set on the hot steam main pipe, and the heat storage device 20 has the ability of bidirectional heat supply. The heat storage device 20 can not only supply heat to heat users outside the factory, but also supply heat and maintain heat to the shut-down steam turbine to keep the steam turbine in a warm state at all times, thereby reducing the startup speed; among them, the waste heat recovery steam from multiple steam turbines and solid waste pyrolysis gasification units can be stored through the hot steam main pipe. On the basis of external heat supply, the heat storage device 20 can also supply steam to the above equipment in reverse to meet the functions of insulation, preheating, etc.

[0029] In another specific embodiment based on the above, the gas turbine power generation unit includes a gas turbine 1 and a gas turbine generator 2. The compression part of the gas turbine 1 is connected to the air, and the combustion chamber of the gas turbine 1 is connected to the natural gas and the synthetic gas provided by the solid waste pyrolysis gasification unit. The output end of the gas turbine 1 is connected to the gas turbine generator 2 through a shaft. The gas turbine generator 2 is used to supply power to the outside of the factory and the solid waste pyrolysis gasification unit. The high-temperature flue gas produced by the gas turbine 1 is connected to the cogeneration unit.

[0030] In the above scheme, the natural gas is used as the primary fuel gas, and the synthetic gas is used as the auxiliary fuel gas. The blending ratio is adjusted as needed, without affecting the interchangeability of the blended gases. The auxiliary fuel gas supply can be continuous or intermittent. The connecting pipeline between the gas turbine 1 and the natural gas is also equipped with a valve a1-1 for regulating the flow.

[0031] In the above scheme, the load of gas turbine 1 can be adjusted in two ways: 1. Adjust the fuel flow according to grid requirements until gas turbine 1 is shut down; 2. After entering the low-load range, if the power supply load of gas turbine 1 exceeds the grid requirements, maintain the output of gas turbine 1 and send the excess power to the solid waste pyrolysis gasification unit to drive solid waste gasification. When adjusting gas turbine 1, syngas is preferred, provided that the post-blending interchangeability and the high-pressure gas storage capacity allow.

[0032] In another specific embodiment based on the above, the cogeneration unit includes a supplementary combustion type waste heat boiler 3, a plurality of steam turbines, a plurality of steam turbine generators, a condenser 8 and a circulating pump 9, the steam turbines include steam turbine A4 and steam turbine B5, the steam turbine generators include steam turbine generator A6 and steam turbine generator B7, the supplementary combustion type waste heat boiler 3 is connected to the high-temperature flue gas produced by the gas turbine power generation unit, and is connected to the synthetic gas provided by the solid waste pyrolysis gasification unit as an auxiliary fuel, and the water vapor generated by the supplementary combustion type waste heat boiler 3 enters the steam turbine at the same time or separately. A4 and steam turbine B5. Turbines A4 and B5 are connected to turbine generators A6 and B7, respectively, via their respective bearings. Turbine generators A6 and B7 supply power to the plant. Turbines A4 and B5 are also connected to a heating steam main, which connects them to the plant and heat storage device 20 for heat transfer. Turbines A4 and B5 are also connected in sequence to a condenser 8 and a circulating pump 9. Circulating pump 9 replenishes water before connecting to the supplemental-fired waste heat boiler 3 to complete the circulation cycle. In this solution, multiple circulating pumps can be used in parallel.

[0033] The synthesis gas provided by the solid waste pyrolysis and gasification unit can be supplied continuously or intermittently. The fuel quantity and the heat provided by the supplementary combustion type waste heat boiler 3 are determined by the oxygen content in the high-temperature flue gas produced by the gas turbine power generation unit. The load of the supplementary combustion type waste heat boiler 3 can be adjusted in two ways: 1. By adjusting the load of the gas turbine power generation unit; 2. By supplementing the synthesis gas to increase the thermal load. The activation and deactivation of the supplementary combustion mode of the supplementary combustion type waste heat boiler 3 is primarily used to adjust the thermal load, not the power load.

[0034] In the above scheme, N steam turbines can be configured. That is, within a single combined cycle system, one gas turbine 1 is configured with N steam turbines, forming a "one-to-N" solution, with a range of 2 ≤ N ≤ 4. Steam turbines can be configured with equal or unequal capacity. The number of operating turbines and operating loads can be freely combined based on the minimum load limit of the steam turbines, thereby achieving ultra-low heating loads. Steam turbines are not limited to either extraction-condensing or backpressure types; mixed configurations are also possible. For example, in the case of two steam turbines, both can operate simultaneously, one while the other is shut down, or even both shut down simultaneously, thus achieving flexible and wide-load heat supply. By burning the synthesis gas in the supplementary-fired waste heat boiler 3, the gas turbine power generation unit can be shut down and the steam turbine can be operated independently, thus achieving decoupling of the combined cycle. In a non-maintenance, peak-shaving scenario, if one steam turbine is shut down due to low load, the heat storage device 20 can supply a small amount of steam to the shut-down turbine, keeping it in a hot standby state of >150°C. When the grid issues a demand response, the shut-down turbine does not need to be started from a cold state, but can be started directly from a warm state, thus shortening the turbine response time by at least one-third, or 60 minutes. In this solution, the steam extracted from the steam turbine passes through the heating steam main pipe, then passes through the desuperheating and pressure reduction device 21 to adjust the temperature and pressure parameters, and is ultimately supplied to the outside of the plant. The exhaust gas from the supplementary-fired waste heat boiler 3 is automatically discharged.

[0035] Among them, valves b2-1 and c2-2 are respectively provided on the pipes connecting the supplementary-fired waste heat boiler 3 to the steam turbine A4 and the steam turbine B5, and valves d2-3 and e2-4 are respectively provided on the pipes connecting the steam turbine A4 and the steam turbine B5 to the heating steam main pipe.

[0036] In another specific embodiment based on the above, the solid waste pyrolysis gasification unit includes a feeder, a drying preheater 12, a gasifier 13, an oxygen-enriched production and storage unit, a particulate matter collector 14, a high-temperature heat exchanger 15, a low-temperature heat exchanger 16, an impurity gas removal device 17 and a decarbonized synthesis gas high and low storage unit. The feeder is used to input solid waste and transport the solid waste to the drying preheater 12, and the dried solid waste is transported from the drying preheater 12 to the gasifier 13. The oxygen-enriched production and storage unit is used to supply oxygen to the gasifier 13. The gasifier 13 is generated by a gas turbine. The electric unit supplies power and outputs high-temperature flue gas to the particulate collector 14. After the high-temperature flue gas is dust-removed by the particulate collector 14, it is input into the high-temperature heat exchanger 15 and stored in the heat storage device 20 by the high-temperature heat exchanger 15. The heat is then transported to the low-temperature heat exchanger 16. The low-temperature heat exchanger 16 is used to supply hot gas to the gasifier 13 and the dry preheater 12, and then transported to the impurity gas removal device 17. The impurity gas removal device 17 is used to provide synthetic gas to the gas turbine power generation unit and the cogeneration unit respectively. The heat storage device 20 is also connected to the dry preheater 12 for heat supply.

[0037] Therefore, during operation, when the power generated by the gas turbine power generation unit exceeds the grid demand, the gasifier 13 operates in electric heating mode, where the excess electricity is used to heat the gasifier 13. When the power generated is less than or equal to the grid demand, the gasifier 13 operates in self-heating mode, using oxygen-enriched gas as the gasification medium, which reacts with a portion of the combustible gas to release heat. Either mode can be selected, or both can be used simultaneously. Furthermore, the high-temperature heat exchanger 15 is connected to the heat storage device 20, allowing the water vapor generated by the high-temperature heat exchanger 15 to be stored in the heat storage device 20.

[0038] In this solution, the waste heat of the gasification product is recovered in two stages, wherein the steam generated in the high-temperature section can be used to heat the drying preheater 12 or to store heat in the heat storage device 20. The high-temperature heat exchanger 15 and the low-temperature heat exchanger 16 can be replenished with water as needed when in use.

[0039] In this solution, the syngas passes through the impurity gas removal device 17 to separate the acidic gases, resulting in high-purity CO2 and low-carbon syngas rich in CO and H2. This low-carbon raw material has a low-carbon property. By removing CO2, the carbon footprint of the syngas is further reduced. The volume ratio of low-carbon syngas blended into the system does not exceed 15%, and the carbon emission reduction ratio can reach 29%. In this solution, the low-carbon syngas is preferentially used as fuel for the gas turbine 1 within this system. When the system's heating capacity is insufficient, it enters the supplementary-fired waste heat boiler 3 for combustion, increasing the heating capacity of the supplementary-fired waste heat boiler 3. Furthermore, by using biomass solid waste syngas, the carbon emission reduction rate can be further increased.

[0040] Among them, a valve n4-1 is provided on the pipeline connecting the low-temperature heat exchanger 16 and the drying preheater 12, and a valve o4-2 is provided on the pipeline connecting the heat storage device 20 and the drying preheater 12.

[0041] In this way, valve n4-1 can be controlled preferentially as needed to utilize the low-temperature heat exchanger 16 to provide waste heat from the low-temperature section of the synthesis gas for drying in the drying preheater 12. Secondly, valve o4-2 can be controlled as needed to utilize the heat storage device 20 to provide heat, and this will not affect the low-temperature heat exchanger 16 supplying gas to the gasifier 13. In this solution, valves n4-1 and o4-2 can be opened simultaneously, or separately as needed.

[0042] In a further specific embodiment, the above-mentioned oxygen-enriched production and storage unit includes an air separation unit 10 and an oxygen-enriched storage device 11. The air separation unit 10 is powered by a gas turbine power generation unit and is directly connected to a gasifier 13 through a pipeline for supplying air to the gasifier 13. A valve g3-1 is installed on the pipeline connecting the air separation unit 10 and the gasifier 13; the air separation unit 10 is also connected to the oxygen-enriched storage device 11 for storing oxygen-enriched gas through a pipeline, and a valve h3-2 is installed on the pipeline between the air separation unit 10 and the oxygen-enriched storage device 11. The oxygen-enriched storage device 11 is connected to the gasifier 13 through a pipeline, and a valve i3-3 is installed on the pipeline between the oxygen-enriched storage device 11 and the gasifier 13.

[0043] In the above scheme, the air separation unit 10 includes the necessary compression machinery. During operation, when the heating load is low, the material in the oxygen-enriched production and storage unit is used for heat supply. When the output load of the gas turbine power generation unit exceeds the load required by the power grid, the excess electricity is directly used for heating and gasification. These two heating modes can be used independently or in combination.

[0044] The circuit connecting the gas turbine power generation unit to the gasifier 13 is provided with a power regulator a1-2, and the circuit connecting the gas turbine power generation unit to the air separation device 10 is provided with a power regulator b1-3.

[0045] In a further specific embodiment, the above-mentioned decarbonized synthesis gas high and low storage unit includes a high-pressure gas storage tank 18 and a low-pressure gas storage tank 19. The impurity gas removal device 17 is used to supply decarbonized synthesis gas to the high-pressure gas storage tank 18 and the low-pressure gas storage tank 19 respectively after removing the acid gas. The high-pressure gas storage tank 18 is used to supply synthesis gas to the gas turbine power generation unit, and the low-pressure gas storage tank 19 is used to supply synthesis gas to the cogeneration unit.

[0046] Among them, a valve j3-4 is provided on the pipeline connecting the impurity gas removal device 17 and the high-pressure gas storage tank 18, a valve k3-5 is provided on the pipeline connecting the high-pressure gas storage tank 18 and the combustion chamber of the gas turbine 1 of the gas turbine power generation unit, a valve l3-6 is provided on the pipeline connecting the impurity gas removal device 17 and the low-pressure gas storage tank 19, and a valve m3-7 is provided on the pipeline connecting the low-pressure gas storage tank 19 and the supplementary combustion type waste heat boiler 3 of the cogeneration unit.

[0047] In this solution, both high-pressure gas storage 18 and low-pressure gas storage 19 contain compression machinery matched to their respective pressure ratings, as well as expansion machinery for recovering pressure energy. The pressure in high-pressure gas storage 18 is maintained at no less than 5 MPa, and the pressure in low-pressure gas storage 19 is maintained at no less than 0.3 MPa. Based on load requirements, high-pressure gas storage 18 and low-pressure gas storage 19 supply gas to gas turbine 1 and supplementary-fired waste heat boiler 3, respectively, to increase power and heat supply while reducing the carbon intensity of heat and electricity emissions.

[0048] As attached Figure 6 As shown, in the above scheme, the gasifier 13 can adopt an electrically driven gasification device for chemical energy storage with application number CN202122116931.6, and on this basis, an array of oxygen-enriched nozzles 138 connected to the inner cavity are respectively arranged near a plurality of electric heating elements 137. When in use, the feed port 131 of the gasifier 13 is connected to the dry preheater 12, the array of electric heating elements 137 is connected to the gas turbine generator 2, the array of oxygen-enriched nozzles 138 is connected to the oxygen-enriched production and storage unit, the synthesis gas outlet 139 is connected to the particulate matter collector 14, the gasification medium gas nozzle 132 is connected to the low-temperature heat exchanger 16, and the slag discharge port 136 is used for slag discharge.

[0049] The present invention provides a control method for a wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system as follows: All regulation behaviors of this system can be decomposed into the following two basic regulation modes: 1. The heating load Qr remains unchanged and the power supply Pd is regulated; 2. The power supply Pd remains unchanged and the heating load Qr is regulated. The two regulation processes can be referred to in the attached Figure 2 and attached Figure 3 The detailed description is as follows: 1. When the required heat load Qr remains unchanged and the power supply Pd is adjusted: Receive grid adjustment instructions and determine the direction of power supply change, i.e. increase or decrease. When the power supply load needs to be increased, the power supply is gradually increased according to the following procedures based on the initial power: 1) Rapidly reduce the electric heating power of gasifier 13 through power regulator a1-2. This dynamic adjustment of the solid waste treatment volume involves a corresponding reduction in the solid waste treatment volume and processing scale. This adjustment does not affect the operation of the gas-steam combined cycle and can significantly reduce the power demand on the gas turbine generator 2.

[0050] 2) The load and power of the air separation unit 10 are reduced through the power regulator b1-3, and the oxygen stored in the oxygen-enriched gas storage device 11 is used for gasification. This regulation does not affect the operating state of the gas-steam combined cycle and can quickly and significantly reduce the demand for the output power of the gas turbine generator 2.

[0051] 3) Increase the flow through valve k3-5 or valve a1-1 to increase the load on gas turbine 1 and the power of gas turbine generator 2 until gas turbine 1 reaches maximum load. Appropriately decrease the opening of valve d2-3 or valve e2-4 to maintain the extraction steam heat supply while increasing the power of gas turbine generator A6 or gas turbine generator B7. Assuming the compatibility of the blended fuel and the storage capacity of the high-pressure gas storage tank 18 allow, prioritize increasing the supply of syngas to achieve lower carbon emissions.

[0052] 4) If gas turbine 1 reaches maximum load and still cannot meet the power demand, continue to reduce the opening of valve d2-3 or valve e2-4, increasing the power of steam turbine generator A6 or steam turbine generator B7 until valve d2-3 and valve e2-4 are closed. Simultaneously, valve f2-5 is opened and adjusted, and heat storage device 20 is used to ensure external heat supply.

[0053] In this solution, any one of the above measures 1) to 4) can be directly adopted for adjustment, or a flexible combination of them can be used for adjustment, according to the specific load of the combined cycle initial power and the peak power gap.

[0054] When the adjustment target is achieved, stop adjustment.

[0055] When the power supply load needs to be reduced, the power supply can be gradually reduced by taking the opposite measures according to the initial power. Figure 2 Adjustment measures on the right.

[0056] 2. When the required power supply Pd remains unchanged and the heating load Qr is adjusted: Receive the heat network adjustment instruction and specify the direction of heat supply change, i.e. increase or decrease. When the heating load needs to be increased, according to the initial heat supply, gradually increase the heating power according to the following procedures: 1) Open or increase valve f2-5 and use the heat storage device 20 to increase the heat supply. This measure has no effect on the power supply load.

[0057] 2) Prioritize increasing valves k3-5 or a1-1 to increase the power of gas turbine 1 and gas turbine generator 2. Increase the flow rate of valves d2-3 or e2-4 to increase the steam extraction rate of steam turbines A4 or B5. Simultaneously, adjust power regulators a1-2 or b1-3 accordingly based on changes in combined cycle total power, thereby maintaining the total power load constant and increasing heat supply.

[0058] 3) Open or increase valve m3-7 to increase the amount of supplemental combustion in the supplemental heat boiler 3, thereby increasing the power of the steam turbine generator A6 or B7. Two measures are available to offset the increased power generation: 1. Prioritize appropriately decreasing valve a1-1 or k3-5 to reduce the load on gas turbine 1 and the power of gas turbine generator 2, thereby offsetting the increase in steam turbine power. 2. Adjust power regulator a1-2 or power regulator b1-3 to increase the power consumption of gasifier 13 or air separation unit 10, thereby offsetting the increase in steam turbine power.

[0059] In this solution, any one of the above measures 1) to 3) can be used for adjustment based on the initial heating load and heating gap.

[0060] When the adjustment target is achieved, stop adjustment.

[0061] When the heating load needs to be reduced, the heating power can be gradually reduced by taking the opposite measures according to the initial heating capacity. Figure 3 Right side measures.

[0062] The system operation and regulation method of the one-to-N mode of the wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system of the present invention is as follows: In addition to the conventional gas-fired combined heat and power (CHP) unit operation mode, all operations of the CHP unit in heat and power decoupling mode can be broken down into the following two types of regulation: 1. As attached Figure 4 As shown, increasing the load on gas turbine 1 increases the main steam flow rate of supplementary-fired waste heat boiler 3. If all turbines reach their maximum heating load and are unable to continue responding, the heat storage device 20 is called upon to dissipate the stored heat. Otherwise, the load of the operating turbine is checked to see if it is within its normal load range. If so, the opening of the valves upstream of that turbine, such as valve b2-1 on turbine A4, is increased to increase the main steam flow rate of the operating turbine to its maximum flow rate. Simultaneously, the opening of the valves downstream of that turbine, such as valve d2-3 on turbine A4, is decreased to reduce the extraction ratio to maintain or reduce the total extraction rate. If not, turbines in hot standby mode, such as turbine B5 or other turbines in hot standby mode, are activated until all turbines are fully operational.

[0063] 2. As attached Figure 5 As shown, the load on gas turbine 1 is reduced, and the main steam flow rate of supplementary-fired waste heat boiler 3 is reduced. If all turbines reach their minimum heating load and are unable to continue responding, the heat storage device 20 is called upon to meet the demand. Otherwise, the load of the operating turbines is checked to see if it is within its normal load range. If so, the main steam flow rate of the operating turbines is reduced to the minimum flow rate, while the extraction ratio is increased to maintain or increase the total extraction rate. If not, the turbines are shut down one by one and placed in a heat-insulating state until only one is operating.

[0064] A specific embodiment of the present invention is as follows: Taking the conventional one-on-one mode 6F.03 combined cycle cogeneration unit as an example, the power of gas turbine 1 at rated load is 80 MW, the main steam flow is 120 t / h, the turbine power in pure condensing mode is 41 MW, and the characteristics of the cogeneration mode with extraction steam heating are as follows: When the load of gas turbine 1 is 100%, the maximum steam extraction capacity is 90 t / h, and the corresponding turbine power is 21 MW.

[0065] When the load of gas turbine 1 is 50%, the main steam flow rate is 60.2 t / h. Due to the limitation of the minimum flow rate of 30.4 t / h, the maximum extraction steam volume is 29.8 t / h. At this time, the total power is 57 MW.

[0066] When the load of gas turbine 1 is 30%, the main steam flow rate is 36.1 t / h, and there is no heating capacity at this time.

[0067] The cold start time of the steam turbine shall be at least 300 minutes.

[0068] To improve heat supply flexibility through thermal decoupling, switching from a one-to-one configuration to a one-to-two configuration, i.e., deploying two extraction-condensing steam turbines of equal capacity, yields the following cogeneration characteristics: the minimum flow rate per steam turbine is reduced to 15.23 t / h. Using a single turbine operating mode with one turbine shut down and one turbine running, the maximum heat supply capacity for gas turbine 1 at 50% load is 45 t / h, approximately 1.5 times the 30.4 t / h corresponding to the one-to-one configuration. At 30% load, the maximum heat supply capacity reaches 20.9 t / h, indicating that gas turbine 1 still has a significant heat supply capacity even at low loads, thus overcoming the strict thermal coupling constraints of the original configuration. Furthermore, the solid waste pyrolysis and gasification unit can supply an additional approximately 3.5 t / h of heat, approximately 4% of the maximum extraction steam capacity of a conventional unit. Combined with the heat storage device 20, this allows for flexible enhancement of external heat supply capacity.

[0069] In terms of improving power supply flexibility, the solid waste consumption is 2.4 t / h, the electric power in electric heating mode is 3.41 MW, and the electric power in self-heating mode is 0.79 MW. By switching between electric heating mode and self-heating mode, or only using the enriched oxygen of the oxygen-enriched storage device 11, 2.62 MW or 3.41 MW or electric load can be internally consumed or supplied externally in a very short time, which is about 3.2% or 3.5% of the maximum power supply power of the pure condensing mode of a conventional combined cycle unit.

[0070] In terms of rapid turbine start-up, the cold start-up time of a conventional unit is 300 minutes; by switching to a one-to-two mode and keeping the shut down turbine warm, the start-up time is shortened to 180 minutes, a 40% reduction in start-up time.

[0071] In terms of carbon emission intensity, according to the "Guidelines for Accounting and Reporting of Corporate Greenhouse Gas Emissions for Power Generation Facilities," the carbon emission intensities of conventional natural gas for power generation and heating are 0.285 tCO2 / MWh and 0.052 tCO2 / GJ, respectively. When blending with 15% low-carbon syngas, without considering the storage of CO2 purified from syngas, the carbon emission intensities for power generation and heating are reduced to 0.241 tCO2 / MWh and 0.044 tCO2 / GJ, respectively. This represents a reduction of approximately 15.4%, roughly the same as the reduction achieved with blending with low-carbon syngas. When the separated high-purity CO2 is stored, the carbon emission intensities for power generation and heating drop to 0.169 tCO2 / MWh and 0.031 tCO2 / GJ, respectively, representing a reduction of approximately 41%. This indicates that blending with low-carbon syngas significantly reduces carbon emissions, enabling low-carbon power generation and heating. The proportion of synthetic gas blended in the gas turbine of the present invention can be between 0 and 15%, which can save 0 to 13% of natural gas and correspondingly reduce carbon emissions by 0 to 13%.

[0072] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0073] The above are only preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of protection of the present invention are within the scope of protection of the present invention. It should be pointed out that for those skilled in the art, it is understood that various changes, modifications, substitutions, embellishments and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and they should be regarded as the scope of protection of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system, characterized by: The invention comprises a gas turbine power generation unit, a cogeneration unit, a solid waste pyrolysis gasification unit and a heat storage device (20), wherein the gas turbine power generation unit is used to access fuel gas and selectively supply power to the outside of the plant and the solid waste pyrolysis gasification unit, and the high-temperature flue gas produced by the gas turbine power generation unit is connected to the cogeneration unit, and several steam turbines in the cogeneration unit cooperate with the steam turbine generator to supply power to the outside of the plant, and the steam turbines are also connected to the heating steam main pipe respectively, and are connected to the outside of the plant and the heat storage device (20) through the heating steam main pipe for heat transfer, and the solid waste pyrolysis gasification unit is used to provide synthetic gas as fuel to the gas turbine power generation unit and the cogeneration unit respectively after processing the input solid waste, and is connected to the heat storage device (20) for heat transfer.

2. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 1 is characterized by: The gas turbine power generation unit comprises a gas turbine (1) and a combustion engine generator (2), wherein the compression part of the gas turbine (1) is connected to air, the combustion chamber of the gas turbine (1) is connected to natural gas and synthetic gas provided by the solid waste pyrolysis gasification unit, the output end of the gas turbine (1) is connected to the combustion engine generator (2), and the combustion engine generator (2) is used to supply power to the outside of the factory and the solid waste pyrolysis gasification unit, and the high-temperature flue gas produced by the gas turbine (1) is connected to the cogeneration unit.

3. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 1 is characterized by: The cogeneration unit includes a supplementary combustion type waste heat boiler (3), a plurality of steam turbines, a plurality of steam turbine generators, a condenser (8) and a circulating pump (9), wherein the steam turbines include a steam turbine A (4) and a steam turbine B (5), and the steam turbine generators include a steam turbine generator A (6) and a steam turbine generator B (7), wherein the supplementary combustion type waste heat boiler (3) is connected to the high-temperature flue gas produced by the gas turbine power generation unit and is connected to the synthetic gas provided by the solid waste pyrolysis gasification unit as an auxiliary fuel, and the water vapor generated by the supplementary combustion type waste heat boiler (3) enters the steam turbine A (4) at the same time or separately. ) and steam turbine B (5), steam turbine A (4) and steam turbine B (5) are connected to steam turbine generator A (6) and steam turbine generator B (7) respectively, and steam turbine generator A (6) and steam turbine generator B (7) supply power to the outside of the plant, steam turbine A (4) and steam turbine B (5) are also connected to the heating steam main pipe respectively, and are connected to the outside of the plant and the heat storage device (20) through the heating steam main pipe for heat transfer, steam turbine A (4) and steam turbine B (5) are also connected to the condenser (8) and the circulating pump (9) in sequence, and the circulating pump (9) is used for connecting to the supplementary combustion type waste heat boiler (3) after water replenishment.

4. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 3 is characterized by: The pipeline connecting the supplementary combustion type waste heat boiler (3) to the steam turbine A (4) and the steam turbine B (5) is respectively provided with a valve b (2-1) and a valve c (2-2), and the pipeline connecting the steam turbine A (4) and the steam turbine B (5) to the heating steam main pipe is respectively provided with a valve d (2-3) and a valve e (2-4).

5. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 1 is characterized by: The solid waste pyrolysis gasification unit comprises a feeder, a drying preheater (12), a gasifier (13), an oxygen-enriched production and storage unit, a particulate matter collector (14), a high-temperature heat exchanger (15), a low-temperature heat exchanger (16), an impurity gas removal device (17) and a decarbonized synthesis gas high and low storage unit. The feeder is used to transport the solid waste to the drying preheater (12), and the dried solid waste is transported from the drying preheater (12) to the gasifier (13). The oxygen-enriched production and storage unit is used to supply oxygen to the gasifier (13). The gasifier (13) is powered by a gas turbine power generation unit and supplies oxygen to the particulate matter collector (14). The particle collector (14) outputs high-temperature flue gas, which is dust-removed by the particle collector (14) and then input into the high-temperature heat exchanger (15). The high-temperature heat exchanger (15) stores heat in the heat storage device (20), and then transports it to the low-temperature heat exchanger (16). The low-temperature heat exchanger (16) is used to supply hot gas to the gasifier (13) and the dry preheater (12). The hot gas is then transported to the impurity gas removal device (17). The impurity gas removal device (17) is used to provide synthetic gas to the gas turbine power generation unit and the cogeneration unit respectively. The heat storage device (20) is also connected to the dry preheater (12) for heat supply.

6. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 5 is characterized by: A valve n (4-1) is provided on the pipeline connecting the low-temperature heat exchanger (16) and the drying preheater (12), and a valve o (4-2) is provided on the pipeline connecting the heat storage device (20) and the drying preheater (12).

7. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 5 is characterized by: The oxygen-enriched production and storage unit comprises an air separation unit (10) and an oxygen-enriched storage unit (11). The air separation unit (10) is powered by a gas turbine power generation unit and is directly connected to the gasifier (13) via a pipeline for supplying gas to the gasifier (13). A valve g (3-1) is installed on the pipeline connecting the air separation unit (10) and the gasifier (13). The air separation unit (10) is also connected to the oxygen-enriched storage unit (11) via a pipeline, and a valve h (3-2) is installed on the pipeline between the air separation unit (10) and the oxygen-enriched storage unit (11). The oxygen-enriched storage unit (11) is connected to the gasifier (13) via a pipeline, and a valve i (3-3) is installed on the pipeline between the oxygen-enriched storage unit (11) and the gasifier (13).

8. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 7 is characterized by: A power regulator a (1-2) is provided on the circuit connecting the gas turbine power generation unit to the gasifier (13), and a power regulator b (1-3) is provided on the circuit connecting the gas turbine power generation unit to the air separation device (10).

9. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 5 is characterized by: The decarbonized synthesis gas high and low storage unit includes a high-pressure gas storage tank (18) and a low-pressure gas storage tank (19). The impurity gas removal device (17) is used to supply synthesis gas to the high-pressure gas storage tank (18) and the low-pressure gas storage tank (19) respectively after removing the acid gas. The high-pressure gas storage tank (18) is used to supply synthesis gas to the gas turbine power generation unit, and the low-pressure gas storage tank (19) is used to supply synthesis gas to the cogeneration unit.

10. The wide-load and low-carbon gas-fired cogeneration and solid waste utilization coupling system according to claim 9, characterized in that: A valve j (3-4) is provided on the pipeline connecting the impurity gas removal device (17) and the high-pressure gas storage tank (18), a valve k (3-5) is provided on the pipeline connecting the high-pressure gas storage tank (18) and the gas turbine power generation unit, a valve l (3-6) is provided on the pipeline connecting the impurity gas removal device (17) and the low-pressure gas storage tank (19), and a valve m (3-7) is provided on the pipeline connecting the low-pressure gas storage tank (19) and the cogeneration unit.

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