Hydrogen fuel gas turbine combined cycle device system with cold energy cascade utilization and application

Abstract

The application provides a hydrogen fuel gas turbine combined cycle device system and application of cold energy cascade utilization, which comprises a high-pressure hydrogen gas source and processing unit, a hydrogen expander unit, a hydrogen fuel processing unit of a gas turbine, a gas turbine unit power generation unit and a waste heat boiler unit power generation unit connected in sequence. In the application, high-pressure hydrogen gas from the high-pressure hydrogen gas source and processing unit is subjected to pressure energy and cold energy recycling through the hydrogen expander unit, the recycled pressure energy is expanded to do work, and the recycled cold energy is subjected to heat exchange through a heat exchanger, so that hydrogen fuel gas turbine combined cycle system power generation can be carried out more efficiently and at a lower cost, and good economic benefits and environmental benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of gas turbine combined cycle power generation technology, and in particular to a hydrogen fuel gas turbine combined cycle device system and its application that utilizes cold energy in a cascade manner. Background Technology

[0002] Hydrogen is a recognized green, efficient, and high-quality energy source. Hydrogen fuel cell gas turbine power generation can effectively reduce emissions, improve environmental quality, adjust energy structure, lower energy costs, and increase economic benefits. Currently, hydrogen fuel cell gas turbine technology is being developed both domestically and internationally, and the proportion of hydrogen blended into natural gas-fired gas turbines will continue to rise in the future.

[0003] However, in a hydrogen fuel cell combined cycle system, the high-pressure hydrogen source reaches 20 MPa or higher. After passing through a pressure regulating device, the pressure of the high-pressure hydrogen is adjusted to about 4 MPa at the inlet pressure of the natural gas and hydrogen mixture skid. During this process, a large amount of pressure energy is lost, and the temperature drops after pressure regulation, making downstream pipelines prone to ice blockage and corrosion.

[0004] Therefore, developing and applying a hydrogen fuel gas turbine combined cycle system that utilizes cold energy in a cascade manner is of great significance for making full use of high-pressure hydrogen energy. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a hydrogen fuel gas turbine combined cycle device system and application for the cascade utilization of cold energy. It can utilize the pressure energy and cold energy of high-pressure hydrogen to improve the system's energy utilization efficiency and reduce the power plant's power consumption rate; moreover, it can also reduce carbon dioxide emissions and has the prospect of large-scale promotion and application.

[0006] To achieve this objective, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a hydrogen fuel gas turbine combined cycle device system for the cascade utilization of cold energy, the hydrogen fuel gas turbine combined cycle device system comprising a high-pressure hydrogen gas source and processing unit, a hydrogen expander unit, a gas turbine hydrogen fuel processing unit, a gas turbine generator unit and a waste heat boiler generator unit connected in sequence.

[0008] The hydrogen expander unit is connected to the gas turbine generator unit and the waste heat boiler generator unit, respectively.

[0009] The cold energy cascade utilization hydrogen fuel gas turbine combined cycle device system provided by this invention sends high-pressure hydrogen generated by a high-pressure hydrogen source and processing unit into a hydrogen expander unit, making full use of the capacity of high-pressure hydrogen, including the expansion work and the cold energy released during the expansion process, further improving the energy recovery and utilization efficiency, reducing the power plant's power consumption rate, increasing the output power of the gas turbine and the energy utilization efficiency of the entire system, reducing the power plant's operating costs, and having good economic and environmental benefits.

[0010] Preferably, the high-pressure hydrogen source and processing unit includes a hydrogen unloading column, a high-pressure hydrogen transmission pipeline, a high-pressure hydrogen storage tank, a filter, an expander unit inlet valve, an expander unit inlet regulating valve, a hydrogen venting shut-off valve, a hydrogen venting flow regulating valve, a long-distance pipeline gas supply shut-off valve, and a long-distance pipeline gas supply flow regulating valve.

[0011] The high-pressure hydrogen source and processing unit of the present invention receives and stores high-pressure hydrogen from an upstream high-pressure hydrogen source, and simultaneously provides the required hydrogen to the downstream gas turbine generator unit.

[0012] Preferably, the hydrogen unloading column, the hydrogen venting shut-off valve, and the hydrogen venting flow regulating valve are connected in series.

[0013] Preferably, the high-pressure hydrogen transmission pipeline, the long-distance pipeline gas supply shut-off valve, and the long-distance pipeline gas supply flow regulating valve are connected in series.

[0014] Preferably, both the hydrogen venting flow regulating valve and the long-distance pipeline gas supply flow regulating valve are connected to the high-pressure hydrogen storage tank.

[0015] Preferably, the high-pressure hydrogen storage tank is connected in series with the filter, the expander inlet valve, and the expander inlet regulating valve.

[0016] Preferably, the hydrogen expander unit includes at least three expanders, such as three, four, or five expanders.

[0017] The expander described in this invention is connected to a generator via a gearbox. The speed is reduced to the required speed by a high-speed reducer, and the expander generates electricity. The electrical energy output by the expander is directly connected to the power plant's auxiliary power system.

[0018] Preferably, the expander includes any one of a turbine expander, a single-screw expander, or a twin-screw expander.

[0019] Preferably, the hydrogen expander unit includes a first-stage expander, a first heat exchanger, a second-stage expander, a second heat exchanger, a third-stage expander, a third heat exchanger, and a fifth heat exchanger connected in sequence. It can utilize the cold energy of the gas at the expander outlet and heat the gas temperature entering the next stage expander inlet, which is beneficial for efficiently recovering the pressure energy of high-pressure gas and improving energy recovery efficiency.

[0020] Preferably, the hydrogen expander unit further includes a first expander diversion exhaust valve, a first expander diversion regulating valve, and a fourth heat exchanger, which are cyclically connected to the first-stage expander.

[0021] Preferably, the fourth heat exchanger is circulatedly connected to the circulating pump, water cooler, shut-off valve, and flow regulating valve.

[0022] Preferably, the third-stage expander is connected to the fifth heat exchanger via the second expander diversion exhaust valve and the second expander diversion regulating valve.

[0023] Preferably, the fifth heat exchanger is connected to a closed-loop circulating water pipeline.

[0024] The hydrogen expander unit of the present invention also includes a pressure energy recovery monitoring system, which automatically and continuously monitors and controls the operation of the expander unit and its auxiliary systems to ensure the safety of personnel and equipment. The system includes the necessary detection instruments and control system, and has functions such as start-up, shutdown, monitoring and control, interlock protection, and emergency shutdown of the expander unit.

[0025] Preferably, the gas turbine hydrogen fuel processing unit includes a hydrogen flow meter, a hydrogen mixing device, a gas pre-processing module, and a fuel gas module connected in sequence.

[0026] Preferably, the gas turbine generator unit includes a gas turbine intake module, a compressor, a combustion chamber, and a turbine connected in sequence.

[0027] Preferably, the compressor and the turbine are coaxially connected.

[0028] Preferably, the gas turbine intake module is circulated with the coolant circulation pump and the third heat exchanger.

[0029] Preferably, the compressor is connected to the second heat exchanger, the turbine rotor cooling air inlet valve, the turbine rotor cooling air regulating valve, the filter, and the turbine circulation.

[0030] Preferably, the waste heat boiler unit power generation unit includes a waste heat boiler, a steam turbine, a condenser, and a condensate pump connected in a cycle.

[0031] Preferably, the waste heat boiler unit power generation unit includes a flue gas separator, a flue gas fan, and a carbon dioxide treatment device connected in sequence to the waste heat boiler.

[0032] Preferably, a first heat exchanger is provided between the waste heat boiler and the flue gas separator.

[0033] Preferably, the condenser is connected to both the cooling water inlet pipe and the cooling water outlet pipe.

[0034] Preferably, the cooling water outlet pipe is circulated and connected to the water pump, water cooler, and cooling water inlet pipe.

[0035] In a second aspect, the present invention also provides an application of a hydrogen fuel gas turbine combined cycle system for the cascade utilization of cold energy as described in the first aspect, characterized in that the steps of the application include:

[0036] High-pressure hydrogen enters the hydrogen expander unit from the high-pressure hydrogen source and processing unit. It expands and does work in the expander in stages, utilizing the pressure energy and cold energy of the high-pressure hydrogen. Then it enters the gas turbine hydrogen fuel processing unit, the gas turbine power generation unit and the waste heat boiler power generation unit in sequence for heat exchange and combustion to generate electricity.

[0037] During the process of high-pressure hydrogen expanding and doing work in stages, it exchanges heat with the gas turbine generator unit and the waste heat boiler generator unit.

[0038] The application of the hydrogen fuel gas turbine combined cycle device system for cascade utilization of cold energy provided by this invention recovers and utilizes the pressure energy and cold energy of high-pressure hydrogen through a hydrogen expander unit. The recovered pressure energy expands to do work, and the recovered cold energy is exchanged for heat through a heat exchanger. This allows for more efficient and lower-cost power generation from gas turbine units and waste heat boiler units.

[0039] Preferably, the high-pressure hydrogen comes from a hydrogen unloading column and a high-pressure hydrogen delivery pipeline, respectively. The high-pressure hydrogen from the hydrogen unloading column enters the high-pressure hydrogen storage tank sequentially through a hydrogen vent shut-off valve and a hydrogen vent flow regulating valve; the high-pressure hydrogen from the high-pressure hydrogen delivery pipeline enters the high-pressure hydrogen storage tank sequentially through a long-distance pipeline supply shut-off valve and a long-distance pipeline supply flow regulating valve. After the two are combined, they sequentially pass through a filter, an expander unit inlet valve, and an expander unit inlet regulating valve to enter the first-stage expander.

[0040] Preferably, high-pressure hydrogen gas undergoes expansion and heat exchange in sequence through a first-stage expander, a first heat exchanger, a second-stage expander, a second heat exchanger, a third-stage expander, and a third heat exchanger. Afterward, it passes through a hydrogen flow meter and a hydrogen mixing device. Natural gas enters from the hydrogen mixing device and mixes with the hydrogen. Both enter the gas preheating module and the fuel gas module for processing, then enter the combustion chamber of the gas turbine generator unit. There, they mix and burn with air that has passed through the gas turbine intake module and the compressor. The resulting flue gas enters the turbine and then sequentially enters the waste heat boiler, the first heat exchanger, the flue gas separator, and the flue gas fan. Finally, it enters the carbon dioxide treatment device to capture the carbon dioxide in the flue gas.

[0041] Preferably, when pure oxygen is used for combustion in the combustion chamber, the products are carbon dioxide and water, and the carbon dioxide is liquefied and recovered in the carbon dioxide treatment device.

[0042] Preferably, air from the atmosphere enters the gas turbine intake module of the gas turbine generator unit, and the gas turbine intake module includes a filter, a silencer and a heat exchanger arranged in sequence.

[0043] Preferably, the air enters the gas turbine intake module and exchanges heat with the first heat exchange medium. After the first heat exchange medium enters the third heat exchanger via the coolant circulation pump, it returns to the gas turbine intake module. By drawing air from the final stage of the cooling compressor, the temperature of the cooling air entering the gas turbine rotor can be reduced, and the amount of cooling air used for the turbine can be reduced, thereby increasing the turbine output and ultimately improving the output and efficiency of the gas turbine.

[0044] Preferably, the first heat exchange medium comprises a water-ethylene glycol solution, wherein the concentration of ethylene glycol is 50%.

[0045] Preferably, the air from the compressor outlet also enters the second heat exchanger for heat exchange, and after passing through the turbine rotor cooling air inlet valve, the turbine rotor cooling air regulating valve and the filter in sequence, it enters the turbine, mainly to cool the first three stages of the turbine rotor impeller and moving blades.

[0046] Preferably, a portion of the high-pressure hydrogen entering the first heat exchanger exchanges heat with the flue gas at the outlet of the waste heat boiler, while the other portion passes sequentially through the first expander diversion exhaust valve and the first expander diversion regulating valve into the fourth heat exchanger, where it exchanges heat with the second heat exchange medium before entering the second heat exchanger.

[0047] Preferably, the second heat exchange medium comprises a 50% ethylene glycol solution.

[0048] Preferably, in the fourth heat exchanger, the second heat exchange medium passes through a circulating pump, a shut-off valve, and a flow regulating valve in sequence, exchanges heat with cooling water in the water cooler, and then returns to the fourth heat exchanger.

[0049] Preferably, a portion of the high-pressure hydrogen gas from the outlet of the third-stage expander enters the fifth heat exchanger sequentially through the second expander diversion exhaust valve and the second expander diversion regulating valve, where it exchanges heat with the closed-loop circulating water. By providing cooling to the closed-loop circulating water, the closed-loop circulating water, after absorbing cold energy, is sent back to a suitable system within the power plant for cold energy utilization. It can serve as a summer cooling source for the power plant's office air conditioning, saving electricity for the power plant's domestic use, or as a cooling source for the gas turbine unit's cooling water, reducing the cooling tower load and saving power plant operating electricity.

[0050] Preferably, the high-pressure steam generated by the waste heat boiler enters the steam turbine to do work, then enters the condenser and is returned to the waste heat boiler via the condensate pump. This can cool the steam turbine exhaust, reduce the steam turbine exhaust back pressure, and thus improve power generation and unit efficiency.

[0051] Preferably, the cooling water enters the condenser to exchange heat with the steam; after heat exchange, the cooling water is pumped into a water cooler for further heat exchange, then enters the condenser to exchange heat with the steam, and finally is discharged.

[0052] Compared with the prior art, the present invention has at least the following beneficial effects:

[0053] (1) The hydrogen fuel gas turbine combined cycle device system for cold energy cascade utilization provided by the present invention uses a hydrogen expander unit to replace the hydrogen pressure regulating device in the prior art. It utilizes the high pressure energy of high-pressure hydrogen to convert it into electrical energy, which can directly increase the power output of the power plant and reduce the power consumption of the plant, thus having direct economic benefits.

[0054] (2) The cold energy cascade utilization hydrogen fuel gas turbine combined cycle device system provided by the present invention recovers and utilizes the cold energy of the generated low-temperature hydrogen gas during the pressure energy recovery process. By reducing the gas turbine inlet temperature, the power generation power and efficiency of the gas turbine are improved. By reducing the exhaust back pressure of the steam turbine, the power generation power and efficiency of the steam turbine are improved.

[0055] (3) The hydrogen fuel gas turbine combined cycle device system for cold energy cascade utilization provided by the present invention can reduce the temperature of the cooling air entering the gas turbine rotor by cooling the last stage of the compressor, thereby reducing the amount of cooling air used for the turbine, thereby increasing the turbine output, and ultimately improving the output and efficiency of the gas turbine.

[0056] (4) The hydrogen fuel gas turbine combined cycle device system for cold energy cascade utilization provided by the present invention improves the overall utilization efficiency of the gas turbine combined cycle power plant by providing cooling for the closed-loop circulating water of the power plant. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of a hydrogen fuel gas turbine combined cycle device system for the cascade utilization of cold energy provided by the present invention.

[0058] In the diagram: 100 - Gas turbine intake module; 101 - Compressor; 102 - Combustion chamber; 103 - Turbine; 104 - Turbine rotor cooling air intake valve; 105 - Turbine rotor cooling air regulating valve; 106 - Filter; 107 - Coolant circulation pump;

[0059] 200-Waste heat boiler; 201-Steam turbine; 202-Condenser; 203-Condensate pump; 204-Water pump; 205-Flue gas separator; 206-Flue gas fan; 207-Carbon dioxide treatment unit;

[0060] 300 - Hydrogen unloading column; 301 - High-pressure hydrogen transmission pipeline; 302 - High-pressure hydrogen storage tank; 303 - Filter; 304 - Expander unit inlet valve; 305 - Expander unit inlet regulating valve; 306 - Hydrogen vent shut-off valve; 307 - Hydrogen vent flow regulating valve; 308 - Long-distance pipeline gas supply shut-off valve; 309 - Long-distance pipeline gas supply flow regulating valve;

[0061] 400 - First stage expander; 401 - First heat exchanger; 402 - Second heat exchanger; 403 - Third heat exchanger; 404 - Fourth heat exchanger; 405 - Fifth heat exchanger; 406 - Second stage expander; 407 - Third stage expander; 408 - First expander diversion exhaust valve; 409 - First expander diversion regulating valve; 410 - Circulation pump; 411 - Shut-off valve; 412 - Flow regulating valve; 413 - Water cooler; 414 - Second expander diversion exhaust valve; 415 - Second expander diversion regulating valve;

[0062] 500 - Hydrogen flow meter; 501 - Hydrogen mixing device; 502 - Gas pre-processing module; 503 - Fuel gas module. Detailed Implementation

[0063] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0064] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0065] It should be understood that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0066] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0067] Those skilled in the art should understand that the present invention necessarily includes the necessary pipelines, conventional valves and general pump equipment for achieving process integrity, but the above content is not the main inventive point of the present invention. Those skilled in the art can add layouts based on process flow and equipment structure selection, and the present invention does not make any special requirements or specific limitations in this regard.

[0068] As a specific embodiment of the present invention, a combined cycle hydrogen fuel cell gas turbine system for cold energy cascade utilization is provided, the schematic diagram of which is shown below. Figure 1 As shown.

[0069] The hydrogen fuel gas turbine combined cycle unit system includes a high-pressure hydrogen gas source and processing unit, a hydrogen expander unit, a gas turbine hydrogen fuel processing unit, a gas turbine power generation unit, and a waste heat boiler power generation unit connected in sequence.

[0070] The hydrogen expander unit is connected to the gas turbine generator unit and the waste heat boiler generator unit, respectively.

[0071] The high-pressure hydrogen source and processing unit includes a hydrogen unloading column 300, a high-pressure hydrogen transmission pipeline 301, a high-pressure hydrogen storage tank 302, a filter 303, an expander unit inlet valve 304, an expander unit inlet regulating valve 305, a hydrogen vent shut-off valve 306, a hydrogen vent flow regulating valve 307, a long-distance pipeline gas supply shut-off valve 308, and a long-distance pipeline gas supply flow regulating valve 309.

[0072] The hydrogen unloading column 300, the hydrogen venting shut-off valve 306, and the hydrogen venting flow regulating valve 307 are connected in series.

[0073] The high-pressure hydrogen transmission pipeline 301, the long-distance pipeline gas supply shut-off valve 308, and the long-distance pipeline gas supply flow regulating valve 309 are connected in series.

[0074] The hydrogen venting flow regulating valve 307 and the long-distance pipeline gas supply flow regulating valve 309 are both connected to the high-pressure hydrogen storage tank 302.

[0075] The high-pressure hydrogen storage tank 302 is connected in series with the filter 303, the expander unit inlet valve 304, and the expander unit inlet regulating valve 305.

[0076] The hydrogen expander unit includes a first-stage expander 400, a first heat exchanger 401, a second-stage expander 406, a second heat exchanger 402, a third-stage expander 407, a third heat exchanger 403, and a fifth heat exchanger 405 connected in sequence.

[0077] The first-stage expander 400, the second-stage expander 406, and the third-stage expander 407 are all turbine expanders.

[0078] The hydrogen expander unit also includes a first expander diversion exhaust valve 408, a first expander diversion regulating valve 409 and a fourth heat exchanger 404, which are cyclically connected to the first-stage expander 400.

[0079] The fourth heat exchanger 404 is circulatedly connected to the circulating pump 410, water cooler 413, shut-off valve 411 and flow regulating valve 412.

[0080] The third-stage expander 407 is connected to the fifth heat exchanger 405 via the second expander diversion exhaust valve 414 and the second expander diversion regulating valve 415.

[0081] The fifth heat exchanger 405 is connected to a closed-loop circulating water pipeline.

[0082] The gas turbine hydrogen fuel processing unit includes a hydrogen flow meter 500, a hydrogen mixing device 501, a gas pre-processing module 502, and a fuel gas module 503 connected in sequence.

[0083] The gas turbine generator unit includes a gas turbine intake module 100, a compressor 101, a combustion chamber 102, and a turbine 103 connected in sequence.

[0084] The compressor 101 and turbine 103 are coaxially connected;

[0085] The gas turbine intake module 100 is circulatedly connected to the coolant circulation pump 107 and the third heat exchanger 403.

[0086] The compressor 101 is cyclically connected to the second heat exchanger 402, the turbine rotor cooling air inlet valve 104, the turbine rotor cooling air regulating valve 105, the filter 106, and the turbine 103.

[0087] The waste heat boiler unit power generation unit includes a waste heat boiler 200, a steam turbine 201, a condenser 202, and a condensate pump 203 connected in a cycle.

[0088] The waste heat boiler unit power generation unit includes a flue gas separator 205, a flue gas fan 206 and a carbon dioxide treatment device 207 connected in sequence to the waste heat boiler 200.

[0089] A first heat exchanger 401 is provided between the waste heat boiler 200 and the flue gas separator 205.

[0090] The condenser 202 is connected to the cooling water inlet pipe and the cooling water outlet pipe respectively;

[0091] The cooling water outlet pipe is circulatedly connected to the water pump 204, the water cooler 413, and the cooling water inlet pipe.

[0092] As a specific embodiment of the present invention, an application of the above-mentioned hydrogen fuel gas turbine combined cycle system for the cascade utilization of cold energy is also provided.

[0093] The gas turbine unit has a rated power of 54MW, the waste heat boiler is a dual-pressure horizontal natural circulation boiler with an evaporation mass flow rate of 77t / h, and the steam turbine is an extraction condensing turbine unit with a pure condensing rated power of 22.6MW. The exhaust flow rate of the gas turbine unit is 486t / h, of which CO2 emissions are 26.1t / h.

[0094] When the gas turbine combustion chamber 102 is mixed with 15% hydrogen, the high-pressure hydrogen from the high-pressure hydrogen storage tank 302 has a pressure of 20 MPa, a temperature of 20 °C, and a flow rate of 2600 m³ / s. 3 The flue gas, passing through filter 303, expander inlet valve 304, and expander inlet regulating valve 305, enters the first-stage expander 400 to perform work, outputting 140kW of power. The exhaust pressure is 12MPa, temperature -25℃, and it is divided into two streams. One stream enters the first heat exchanger 401, where it exchanges heat with the flue gas from the waste heat boiler 200. After cooling, the flue gas passes through flue gas separator 205 to remove water. The remaining flue gas is then sent to carbon dioxide treatment device 207 by flue gas fan 206, which removes all carbon dioxide produced by the combustion of hydrogen-blended natural gas, achieving carbon dioxide emission reduction. Simultaneously, by utilizing cold energy, the energy consumption for carbon dioxide capture is reduced.

[0095] In this specific embodiment, when the gas turbine generator unit operates with 15% hydrogen, CO2 emissions are reduced from 27.936 t / h to 26.1 t / h compared to using all natural gas, i.e., CO2 emission reduction is 1.836 t / h. After adopting the scheme of the present invention, all remaining CO2 is captured, resulting in an additional CO2 emission reduction of 26.1 t / h.

[0096] Another exhaust stream from the first-stage expander 400 enters the fourth heat exchanger 404 after passing through the first expander diversion exhaust valve 408 and the first expander diversion regulating valve 409. This heat exchanger cools a 50% ethylene glycol solution circulating within it. The 50% ethylene glycol solution circulates through the circulating pump 410, shut-off valve 411, and flow regulating valve 412, absorbing the cooling capacity of the fourth heat exchanger 404 and transferring it to the water cooler 413 to cool the condenser cooling water. This, in turn, cools the exhaust steam of the turbine 201, reducing the turbine 201 exhaust back pressure by 1 kPa, thereby increasing the combined cycle power generation by 880 kW.

[0097] The reheated hydrogen gas from the first heat exchanger 401, with a pressure of 12 MPa and a temperature of 15°C, expands and does work in the second-stage expander 406, with an output power of 150 kW. The exhaust pressure is 7 MPa and the temperature is -26°C. It then enters the second heat exchanger 402, where it exchanges heat with the exhaust gas from the last stage of the compressor 101 before entering the third-stage expander 407 to expand and do work. The outlet pressure of the second-stage expander 406 is 3.5 MPa and the temperature is -36°C. The expander output is 190 kW.

[0098] The air from the outlet of compressor 101 is 450°C. After being cooled, it enters turbine 103 to cool the turbine.

[0099] Compared to the prior art where the compressor outlet air of a gas turbine unit directly enters the turbine, this specific implementation reduces the temperature of the cooling air entering the turbine, which will effectively reduce the compressor exhaust air intake. The turbine cooling air intake is reduced by 1 percentage point, and the gas turbine output increases by about 1.5%, to 810kW.

[0100] The exhaust gas from the third-stage expander 407 is split into two streams. One stream enters the third heat exchanger 403, where it exchanges heat with the cooling medium from the coolant circulation pump 107 to cool the air in the gas turbine intake module 100. This serves as a cold source for cooling the gas turbine intake air, thereby increasing the unit's output. Under summer operating conditions, after cooling, the gas turbine intake air temperature drops from 30°C to 15°C, increasing the gas turbine output from 48MW to 54MW, an increase of approximately 11% in power output and 1.1% in efficiency.

[0101] Another exhaust gas from the third-stage expander 407 passes through the second expander diversion exhaust valve 414 and the second expander diversion regulating valve 415 before entering the fifth heat exchanger 405, where it exchanges heat with the power plant's closed-loop circulating water. The reheated hydrogen then enters the gas turbine hydrogen fuel processing unit.

[0102] The hydrogen from the outlets of the third heat exchanger 403 and the fifth heat exchanger 405 merges and enters the hydrogen flow meter 500 in the hydrogen fuel processing unit of the gas turbine. It then passes through the hydrogen mixing device 501, the gas pre-processing module 502, and the fuel gas module 503 in sequence before finally entering the combustion chamber 102 to generate electricity.

[0103] In this specific embodiment, the hydrogen gas expands and depressurizes, lowering its temperature. A heat exchanger is installed after the expander to heat the hydrogen. This serves two purposes: firstly, it heats the hydrogen to meet the temperature requirements for hydrogen transportation and gas turbine fuel processing; secondly, it recovers and utilizes the cold energy contained in the low-temperature hydrogen, thereby improving the overall energy utilization rate. The power recovered during expansion helps reduce plant power consumption and lower power plant operating costs. Furthermore, generating electricity using high-pressure hydrogen does not produce any toxic or harmful gases or liquids, making it a zero-emission power generation device that does not produce CO2.

[0104] The performance data of each device in this specific embodiment are shown in Table 1.

[0105] Table 1

[0106]

[0107] As can be seen from Table 1, after adopting the scheme of this specific implementation, the total output of the expansion turbine is 480kW. The cold energy generated by the turbine expander unit is used to cool the compressor outlet air, thereby increasing the gas turbine output by 810kW. The cold energy is used to cool the intake air in summer conditions, increasing the gas turbine output by 7MW. The cold energy is used to reduce the exhaust back pressure of the steam turbine, resulting in an increase of 880kW in the steam turbine output.

[0108] The combined cycle power output increased by 9.17 MW and the efficiency improved by 6.6 percentage points after adopting the scheme of this specific implementation method. At the same time, CO2 emissions were further reduced by 26.1 t / h, and the annual CO2 emission reduction was 104,400 tons / year based on the annual operation of the unit of 4,000 hours.

[0109] In summary, the hydrogen fuel gas turbine combined cycle device system and application for cold energy cascade utilization provided by this invention replaces the hydrogen pressure regulating device in the prior art with a hydrogen expander unit. It utilizes the high pressure energy of high-pressure hydrogen to convert it into electrical energy, which can directly increase the power plant's output and reduce plant power consumption, resulting in direct economic benefits. Moreover, it reduces carbon dioxide emissions, resulting in good environmental benefits, and is suitable for large-scale promotion and application.

[0110] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A hydrogen fuel cell combined cycle system for cascade utilization of cold energy, characterized in that, The hydrogen fuel gas turbine combined cycle unit system includes a high-pressure hydrogen gas source and processing unit, a hydrogen expander unit, a gas turbine hydrogen fuel processing unit, a gas turbine power generation unit, and a waste heat boiler power generation unit connected in sequence. The hydrogen expander unit is connected to the gas turbine generator unit and the waste heat boiler generator unit, respectively. The hydrogen expander unit includes a first-stage expander, a first heat exchanger, a second-stage expander, a second heat exchanger, a third-stage expander, a third heat exchanger, and a fifth heat exchanger connected in sequence. The gas turbine generator unit includes a gas turbine intake module, a compressor, a combustion chamber, and a turbine connected in sequence. The compressor is connected to the second heat exchanger, turbine rotor cooling air inlet valve, turbine rotor cooling air regulating valve, filter and turbine circulation in the hydrogen expander unit, and is used to pre-cool the cooling air entering the turbine using the cold energy during the hydrogen expansion process. The waste heat boiler unit power generation unit includes a waste heat boiler, a steam turbine, a condenser, and a condensate pump connected in a loop. A first heat exchanger is installed between the waste heat boiler and the flue gas separator.

2. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The high-pressure hydrogen source and processing unit includes a hydrogen unloading column, a high-pressure hydrogen transmission pipeline, a high-pressure hydrogen storage tank, a filter, an expander unit inlet valve, an expander unit inlet regulating valve, a hydrogen vent shut-off valve, a hydrogen vent flow regulating valve, a long-distance pipeline gas supply shut-off valve, and a long-distance pipeline gas supply flow regulating valve.

3. The hydrogen fuel cell gas turbine combined cycle system according to claim 2, characterized in that, The hydrogen unloading column, hydrogen venting shut-off valve, and hydrogen venting flow regulating valve are connected in series.

4. The hydrogen fuel cell gas turbine combined cycle system according to claim 2, characterized in that, The high-pressure hydrogen transmission pipeline, the long-distance pipeline gas supply shut-off valve, and the long-distance pipeline gas supply flow regulating valve are connected in series.

5. The hydrogen fuel cell gas turbine combined cycle system according to claim 2, characterized in that, Both the hydrogen venting flow regulating valve and the long-distance pipeline gas supply flow regulating valve are connected to the high-pressure hydrogen storage tank.

6. The hydrogen fuel cell gas turbine combined cycle system according to claim 2, characterized in that, The high-pressure hydrogen storage tank is connected in series with the filter, the expander inlet valve, and the expander inlet regulating valve.

7. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, Expanders include any one of turbine expanders, single-screw expanders, or twin-screw expanders.

8. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The hydrogen expander unit also includes a first expander diversion exhaust valve, a first expander diversion regulating valve, and a fourth heat exchanger, which are circulated and connected to the first-stage expander.

9. The hydrogen fuel cell gas turbine combined cycle system according to claim 8, characterized in that, The fourth heat exchanger is circulatedly connected to the circulating pump, water cooler, shut-off valve, and flow regulating valve.

10. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The third-stage expander is connected to the fifth heat exchanger via the second expander diversion exhaust valve and the second expander diversion regulating valve.

11. The hydrogen fuel cell gas turbine combined cycle system according to claim 10, characterized in that, The fifth heat exchanger is connected to a closed-loop circulating water pipeline.

12. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The gas turbine hydrogen fuel processing unit includes a hydrogen flow meter, a hydrogen mixing device, a gas pre-processing module, and a fuel gas module connected in sequence.

13. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The compressor and turbine are coaxially connected.

14. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The gas turbine intake module is circulated with the coolant circulation pump and the third heat exchanger.

15. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The waste heat boiler unit power generation unit includes a flue gas separator, a flue gas fan, and a carbon dioxide treatment device connected in sequence to the waste heat boiler.

16. The hydrogen fuel cell gas turbine combined cycle system according to claim 1, characterized in that, The condenser is connected to the cooling water inlet pipe and the cooling water outlet pipe, respectively.

17. The hydrogen fuel cell gas turbine combined cycle system according to claim 16, characterized in that, The cooling water outlet pipe is circulated and connected to the water pump, water cooler, and cooling water inlet pipe.

18. An application of a hydrogen fuel cell gas turbine combined cycle system for the cascade utilization of cold energy as described in any one of claims 1 to 17, characterized in that, The steps of the application include: High-pressure hydrogen enters the hydrogen expander unit from the high-pressure hydrogen source and processing unit. It expands and does work in the expander in stages, utilizing the pressure energy and cold energy of the high-pressure hydrogen. Then it enters the gas turbine hydrogen fuel processing unit, the gas turbine power generation unit and the waste heat boiler power generation unit in sequence for heat exchange and combustion to generate electricity. During the process of high-pressure hydrogen expanding and doing work in stages, it exchanges heat with the gas turbine generator unit and the waste heat boiler generator unit.

19. The application according to claim 18, characterized in that, The high-pressure hydrogen comes from a hydrogen unloading column and a high-pressure hydrogen delivery pipeline. The high-pressure hydrogen from the hydrogen unloading column enters the high-pressure hydrogen storage tank sequentially through a hydrogen vent shut-off valve and a hydrogen vent flow regulating valve. The high-pressure hydrogen from the high-pressure hydrogen delivery pipeline enters the high-pressure hydrogen storage tank sequentially through a long-distance pipeline supply shut-off valve and a long-distance pipeline supply flow regulating valve. After the two are combined, they enter the first-stage expander sequentially through a filter, an expander unit inlet valve, and an expander unit inlet regulating valve.

20. The application according to claim 18, characterized in that, High-pressure hydrogen gas undergoes expansion and heat exchange in sequence through the first-stage expander, the first heat exchanger, the second-stage expander, the second heat exchanger, the third-stage expander, and the third heat exchanger. It then passes through a hydrogen flow meter and a hydrogen mixing device. Natural gas enters from the hydrogen mixing device and mixes with the hydrogen. Both gases then enter the gas preheating module and the fuel gas module for processing. Finally, they enter the combustion chamber of the gas turbine generator unit, where they mix and burn with air that has passed through the gas turbine intake module and the compressor. The resulting flue gas enters the turbine and then sequentially passes through the waste heat boiler, the first heat exchanger, the flue gas separator, and the flue gas fan. Finally, it enters the carbon dioxide treatment device to capture the carbon dioxide in the flue gas.

21. The application according to claim 20, characterized in that, The air enters the gas turbine intake module and exchanges heat with the first heat exchange medium. The first heat exchange medium enters the third heat exchanger via the coolant circulation pump and then returns to the gas turbine intake module.

22. The application according to claim 21, characterized in that, The first heat exchange medium comprises a water-ethylene glycol solution, wherein the concentration of ethylene glycol is 50%.

23. The application according to claim 20, characterized in that, The air from the compressor outlet also enters the second heat exchanger for heat exchange, and then passes through the turbine rotor cooling air inlet valve, the turbine rotor cooling air regulating valve, and the filter in sequence before entering the turbine.

24. The application according to claim 20, characterized in that, The high-pressure hydrogen entering the first heat exchanger exchanges heat with the flue gas at the outlet of the waste heat boiler, and the other part enters the fourth heat exchanger through the first expander diversion exhaust valve and the first expander diversion regulating valve in sequence. After exchanging heat with the second heat exchange medium therein, it enters the second heat exchanger.

25. The application according to claim 24, characterized in that, The second heat exchange medium comprises a 50% ethylene glycol solution.

26. The application according to claim 24, characterized in that, Inside the fourth heat exchanger, the second heat exchange medium passes through the circulating pump, the shut-off valve, and the flow regulating valve in sequence. After exchanging heat with the cooling water in the water cooler, it returns to the fourth heat exchanger.

27. The application according to claim 20, characterized in that, A portion of the high-pressure hydrogen gas from the outlet of the third-stage expander enters the fifth heat exchanger via the second expander diversion exhaust valve and the second expander diversion regulating valve, where it exchanges heat with the closed-loop circulating water.

28. The application according to claim 20, characterized in that, The high-pressure steam generated by the waste heat boiler enters the steam turbine to do work, then enters the condenser and is returned to the waste heat boiler via the condensate pump.

29. The application according to claim 26, characterized in that, The cooling water enters the condenser to exchange heat with the steam; after heat exchange, the cooling water is pumped into the water cooler for further heat exchange, then enters the condenser to exchange heat with the steam, and finally is discharged.

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