Combined power generation system and method integrating electrolytic tank, hydrogen gas turbine and coal-fired power plant

Abstract

The invention relates to a combined power generation system and method integrating an electrolytic tank, a hydrogen gas turbine and a coal-fired power plant, and the system comprises an electrolysis system, a hydrogen gas turbine power generation system and a coal-fired power generation system, an electrode of the proton exchange membrane electrolytic tank is electrically connected with the renewable energy power generation system, and the hydrogen gas turbine power generation system comprises a combustion chamber and a hydrogen gas turbine which are connected with each other; the combustion chamber is connected with the electrolysis system and burns hydrogen generated by electrolysis to generate steam to drive the hydrogen gas turbine to generate power; the steam turbine set is connected with the hydrogen gas turbine power generation system, and the coal-fired power generation system supplements steam output by the hydrogen gas turbine power generation system to the steam turbine set during load increasing. On the basis of solving the problem of power consumption of renewable energy power generation, the load of the coal-fired unit is increased, the utilization rate of renewable energy is increased, and the flexibility of peak regulation of the coal-fired unit is improved.

Description

Technical Field

[0001] This invention belongs to the technical field of power generation, and in particular relates to a combined power generation system and method integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant. Background Technology

[0002] With the development of renewable energy in my country, the installed capacity of wind power / solar power has gradually increased. However, due to the inability to transmit or consume the generated electricity, the problem of wind and solar curtailment still exists, which prevents the utilization rate of renewable energy power generation from being improved. "Green electricity consumption" has become a problem that needs to be solved in the development of renewable energy in my country.

[0003] Coal-fired power generation systems are quite common. The coal-fired boiler uses the energy released from coal combustion to heat boiler feedwater, generating high-temperature, high-pressure steam which is then sent to the turbine unit to perform work. Each turbine in the turbine unit is coaxially mounted, driving a generator to produce electricity. A typical turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The steam inlet of the high-pressure cylinder is connected to the main steam outlet of the coal-fired boiler via pipeline. The steam inlet of the intermediate-pressure cylinder is connected to the reheat steam outlet of the coal-fired boiler via pipeline. The steam outlet of the intermediate-pressure cylinder is connected to the steam inlet of the low-pressure cylinder via pipeline. The steam outlet of the high-pressure cylinder is connected to the reheat steam inlet of the coal-fired boiler via a steam loop. The exhaust steam from the turbine unit is condensed into condensate in a condenser, then heated sequentially by the low-pressure heater group and the high-pressure heater group before being supplied back to the coal-fired boiler. The low-pressure heater group and the high-pressure heater group achieve recirculation heating by drawing steam from the turbine unit. Coal-fired power units suffer from slow start-up speeds. Due to the high thermal inertia of coal-fired boilers, the rate of load increase is relatively low, resulting in insufficient operational flexibility. Furthermore, with the development of renewable energy, my country's power system currently faces peak-shaving challenges, requiring many coal-fired units to frequently increase load in response to grid dispatch commands, posing a significant challenge to their operational flexibility.

[0004] Proton exchange membrane (PEM) electrolyzers are one of the most promising and efficient methods for producing green hydrogen. They utilize solid proton exchange membranes as the electrolyte to decompose water and produce hydrogen, achieving an efficiency of 70%–80%. Compared to traditional alkaline electrolyzers, PEM electrolyzers offer advantages such as compact structure, rapid dynamic response (second-level adjustment), quick cold start-up, and high hydrogen purity. Furthermore, PEM electrolyzers have a high outlet water temperature, reaching 70℃–95℃, requiring heat exchange to cool the outlet water during operation.

[0005] Hydrogen-oxygen combustion power generation technology uses hydrogen and oxygen as fuel, and utilizes the heat released from combustion to generate high-temperature, high-pressure steam that enters a hydrogen gas turbine to perform work. Its power generation system has a simple layout, mainly consisting of a combustion chamber and a hydrogen gas turbine, and is characterized by fast response and high efficiency. Summary of the Invention

[0006] This invention provides a combined power generation system and method integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant. It addresses the issue of renewable energy power consumption, assists coal-fired units in increasing load, improves the utilization rate of renewable energy, and enhances the flexibility of peak shaving for coal-fired units.

[0007] The technical solution adopted by this invention to solve its technical problem is to provide a combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant, comprising: A coal-fired power generation system, comprising a coal-fired boiler, a steam turbine unit, a low-pressure heater unit, and a high-pressure heater unit, wherein the steam turbine unit is connected to the coal-fired boiler and driven by steam output from the coal-fired boiler, and the condensate from the exhaust steam of the steam turbine unit is supplied to the coal-fired boiler at least partially through the low-pressure heater unit and the high-pressure heater unit in sequence. An electrolysis system, comprising a proton exchange membrane electrolyzer, wherein the electrodes of the proton exchange membrane electrolyzer are electrically connected to a renewable energy power generation system and utilize the electricity generated by the renewable energy power generation system to electrolyze water to produce hydrogen; A hydrogen gas turbine power generation system, comprising a combustion chamber and a hydrogen gas turbine connected to each other, wherein the combustion chamber is connected to an electrolysis system and generates steam by burning hydrogen produced by electrolysis to drive the hydrogen gas turbine to generate electricity; The steam turbine unit is connected to the hydrogen gas turbine power generation system, and the coal-fired power generation system uses the steam output from the hydrogen gas turbine power generation system to supplement the steam turbine unit when the load increases.

[0008] In another embodiment of the present invention, the integrated power generation system of the electrolyzer, hydrogen gas turbine and coal-fired power plant further includes a heat recovery system, which transfers the heat from the outlet water of the proton exchange membrane electrolyzer to the condensate of the exhaust steam at the end of the steam turbine unit through a heat exchange system.

[0009] In another embodiment of the present invention, the heat recovery system includes a first heat exchanger and a fourth heat exchanger connected in series to form a circulating loop. The first heat exchanger is connected in series with a proton exchange membrane electrolyzer, and the outlet water in the proton exchange membrane electrolyzer can enter the first heat exchanger for heat exchange. The fourth heat exchanger is connected in parallel with at least a portion of the low-pressure heaters of the low-pressure heater group, and at least a portion of the condensate from the exhaust steam at the end of the turbine unit can enter the fourth heat exchanger for heat exchange.

[0010] In another embodiment of the present invention, a cold water tank and a hot water tank are further provided in the circulation loop between the first heat exchanger and the fourth heat exchanger.

[0011] In another embodiment of the present invention, a hydrogen storage tank and a first compressor are provided in the hydrogen delivery pipeline between the proton exchange membrane electrolyzer and the combustion chamber, and an oxygen storage tank and a second compressor are provided in the oxygen delivery pipeline between the proton exchange membrane electrolyzer and the combustion chamber.

[0012] In another embodiment of the present invention, the water supply pipeline between the high-pressure heater group and the coal-fired boiler is connected to the combustion chamber through a first water supply branch, and the first water supply branch is equipped with a booster pump.

[0013] In another embodiment of the present invention, the turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The coal-fired boiler is connected to the high-pressure cylinder and the intermediate-pressure cylinder via pipelines. The intermediate-pressure cylinder and the low-pressure cylinder are connected via pipelines. A second heat exchanger and a third heat exchanger are provided between the hydrogen gas turbine and the turbine unit. The steam discharged from the hydrogen gas turbine is diverted into the second and third heat exchangers for heat exchange and then delivered to the intermediate-pressure cylinder. The feedwater pipeline between the high-pressure heater group and the coal-fired boiler supplies water to the second heat exchanger through a second feedwater branch and exchanges heat with the steam discharged from the hydrogen gas turbine before delivering it to the high-pressure cylinder. The steam circuit between the high-pressure cylinder and the coal-fired boiler supplies steam to the third heat exchanger through a steam supply branch and exchanges heat with the steam discharged from the hydrogen gas turbine before delivering it to the intermediate-pressure cylinder.

[0014] In another embodiment of the present invention, the high-pressure cylinder of the steam turbine is connected to the main steam outlet of the coal-fired boiler via a pipeline, the intermediate-pressure cylinder of the steam turbine is connected to the reheat steam outlet of the coal-fired boiler via a pipeline, and the high-pressure cylinder of the steam turbine is connected to the reheat steam inlet of the coal-fired boiler via a steam circuit.

[0015] Another technical solution adopted by the present invention to solve its technical problem is to provide a combined power generation method, which adopts a combined power generation system of an integrated electrolyzer, a hydrogen gas turbine, and a coal-fired power plant as described in any of the above embodiments, and includes the following steps: 1. Determine whether there is excess power in the renewable energy power generation system. When there is excess power, control the circuit between the renewable energy power generation system and the proton exchange membrane electrolyzer electrode to conduct and use the electricity from the renewable energy power generation system to electrolyze water to produce hydrogen. 2. When the coal-fired power generation system needs to increase its load, the hydrogen produced by the electrolysis system is transported to the combustion chamber for combustion to generate steam, and then the steam generated by the hydrogen combustion is transported to the hydrogen gas turbine to drive the hydrogen gas turbine to generate electricity; 3. The steam discharged from the hydrogen gas turbine is transported to the steam turbine unit, and together with the steam transported from the coal-fired boiler, the steam turbine unit is driven.

[0016] In another embodiment of the present invention, the heat from the outlet water of the proton exchange membrane electrolyzer is used to heat the condensate from the exhaust steam at the end of the turbine of the coal-fired power generation system through heat exchange. Beneficial effects

[0017] First, this invention combines an electrolysis system with a renewable energy power generation system. By using a proton exchange membrane electrolysis cell to electrolyze water to produce hydrogen, the excess electricity that the renewable energy power generation system cannot absorb is utilized, and high-purity hydrogen is produced for further reuse. This solves the problem of "wind and electricity curtailment" in existing renewable energy power generation systems due to the inability to absorb the excess electricity.

[0018] Secondly, this invention further combines a hydrogen gas turbine power generation system and a coal-fired power generation system. On the one hand, it uses the high-temperature, high-pressure steam generated by the combustion of hydrogen and oxygen to drive the hydrogen gas turbine for power generation, improving the utilization rate of renewable energy power generation. On the other hand, when the coal-fired power generation system needs to quickly increase its load to participate in peak shaving, the steam from the hydrogen gas turbine power generation system can be used to supplement the steam turbine unit of the coal-fired power generation system to do work, increasing the amount of steam entering the steam turbine unit of the coal-fired power generation system to do work, thereby increasing the power output of the coal-fired power generation system and assisting the coal-fired power generation system in increasing its load. It utilizes the fast response speed of the hydrogen gas turbine power generation system to make up for the shortcomings of the coal-fired power generation system itself, such as slow load increase rate and insufficient operational flexibility, thereby improving the start-up speed of the coal-fired power generation system in increasing its load and increasing the flexibility of system operation.

[0019] Third, some embodiments of the present invention also include a heat recovery system. The heat recovery system can further reuse the heat of the outlet water of the proton exchange membrane electrolyzer through heat exchange to heat the condensate of the exhaust steam at the end of the turbine unit, thereby further improving the utilization rate of renewable energy power generation. On the other hand, when the coal-fired power generation system needs to increase its load to participate in peak shaving, the heat recovery system can exchange heat with part of the feedwater, which helps to reduce or replace the extraction of steam from the turbine unit by the low-pressure heater group, thereby improving the power output and load increase flexibility of the coal-fired power generation system. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of an embodiment of the combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to the present invention.

[0021] Labeling Explanation: 1-Proton exchange membrane electrolyzer; 2-Hydrogen storage tank; 3-Oxygen storage tank; 4-First heat exchanger; 5-Hot water tank; 6-Cold water tank; 7-Combustion chamber; 8-Hydrogen gas turbine; 9-Second heat exchanger; 10-Third heat exchanger; 11-Coal-fired boiler; 12-High-pressure cylinder of steam turbine; 13-Intermediate-pressure cylinder of steam turbine; 14-Low-pressure cylinder of steam turbine; 15-#1 high-pressure heater; 16-#2 high-pressure heater; 17-#3 high-pressure heater; 18-Deaerator of coal-fired boiler; 19-#1 low-pressure heater; 20-#2 low-pressure heater; 21-#3 low-pressure heater; 22-#4 low-pressure heater; 23-Condensate pump; 24-Feed water pump; 25-Fourth heat exchanger; 26-Condenser; 27-Generator; 28-First compressor; 29-Second compressor; 30-Boost pump. Detailed Implementation

[0022] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0023] like Figure 1 The diagram shows a combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant, comprising an electrolysis system, a hydrogen gas turbine power generation system, a coal-fired power generation system, and a heat recovery system.

[0024] In this embodiment, the electrolysis system includes a proton exchange membrane electrolyzer 1, a hydrogen storage tank 2, and an oxygen storage tank 3. The cathode outlet of the proton exchange membrane electrolyzer 1 is connected to the hydrogen storage tank 2 via a pipeline, and the anode outlet of the proton exchange membrane electrolyzer 1 is connected to the oxygen storage tank 3 via a pipeline. The electrodes of the proton exchange membrane electrolyzer 1 are connected to a renewable energy power generation system via a controllable circuit. When the control circuit is active, hydrogen and oxygen can be produced by electrolyzing water using electricity generated by the renewable energy power generation system and then transported to the hydrogen storage tank 2 and the oxygen storage tank 3 for storage.

[0025] In this embodiment, the hydrogen gas turbine power generation system includes a combustion chamber 7 and a hydrogen gas turbine 8. The steam outlet of the combustion chamber 7 is connected to the steam inlet of the hydrogen gas turbine 8 via a pipeline. The combustion chamber 7 is connected to a hydrogen storage tank 2 and an oxygen storage tank 3 via pipelines. A first compressor 28 is installed in the pipeline between the hydrogen storage tank 2 and the combustion chamber 7, and a second compressor 29 is installed in the pipeline between the oxygen storage tank 3 and the combustion chamber 7. These compressors are used to transport hydrogen from the hydrogen storage tank 2 and oxygen from the oxygen storage tank 3 to the combustion chamber 7 for combustion, and to heat a portion of the extracted coal-fired boiler feedwater to generate high-temperature, high-pressure steam, which is then transported to the hydrogen gas turbine 8 to drive the hydrogen gas turbine 8 for power generation.

[0026] In this embodiment, the coal-fired power generation system includes a coal-fired boiler 11, a steam turbine unit, a generator 27, a condenser 26, a condensate pump 23, a low-pressure heater group, a coal-fired boiler deaerator 18, a feedwater pump 24, and a high-pressure heater group. The steam turbine unit includes a high-pressure cylinder 12, an intermediate-pressure cylinder 13, and a low-pressure cylinder 14, all coaxially arranged, and the generator 27 is also coaxially arranged. The high-pressure heater group includes a #1 high-pressure heater 15, a #2 high-pressure heater 16, and a #3 high-pressure heater 17, connected in series via feedwater pipelines. The low-pressure heater group includes a #1 low-pressure heater 19, a #2 low-pressure heater 20, a #3 low-pressure heater 21, and a #4 low-pressure heater 22, connected in series via feedwater pipelines. The main steam outlet of the coal-fired boiler 11 is connected to the steam inlet of the high-pressure cylinder 12 of the turbine via a pipeline. The reheat steam outlet of the coal-fired boiler 11 is connected to the steam inlet of the intermediate-pressure cylinder 13 of the turbine via a pipeline. The steam outlet of the intermediate-pressure cylinder 13 is connected to the steam inlet of the low-pressure cylinder 14 of the turbine. The main steam from the coal-fired boiler 11 is delivered to the high-pressure cylinder 12 of the turbine to perform work, and the reheat steam is delivered to the intermediate-pressure cylinder 13 of the turbine to perform work. Part of the steam from the intermediate-pressure cylinder 13 of the turbine continues to be delivered to the low-pressure cylinder 14 of the turbine to perform work, driving the generator 27 to generate electricity. The exhaust steam from the end of the low-pressure cylinder 14 of the turbine is condensed by the condenser 26 to form condensate to be supplied to the combustion boiler 11. It should be noted that "end exhaust steam" in "end exhaust steam from the low-pressure cylinder 14 of the turbine" does not refer to a limitation on the location of the exhaust steam, but rather refers to the steam discharged from the low-pressure cylinder 14 of the turbine that undergoes subsequent condensation treatment. The condensate output from the condenser 26 is pumped by the condensate pump 23 and successively passes through the No. 4 low-pressure heater 22, No. 3 low-pressure heater 21, No. 2 low-pressure heater 20, No. 1 low-pressure heater 19, coal-fired boiler deaerator 18, feedwater pump 24, No. 3 high-pressure heater 17, No. 2 high-pressure heater 16 and No. 1 high-pressure heater 15 to supply all or part of the water to the combustion boiler 11. Each low-pressure heater in the low-pressure heater group is connected to the low-pressure cylinder 14 of the turbine via pipelines. Steam is extracted from the low-pressure cylinder 14 to heat the feedwater. The extracted steam is then exchanged and transported to the condenser 26. High-pressure heaters 15 and 2 are connected to the high-pressure cylinder 12 of the turbine via pipelines and extract steam from it to heat the feedwater. High-pressure heater 17 and the deaerator 18 of the coal-fired boiler are connected to the intermediate-pressure cylinder 13 of the turbine via pipelines and extract steam from it to heat the feedwater. The steam from high-pressure heaters 15, 26, and 3 is exchanged and transported to the deaerator 18 of the coal-fired boiler to merge with the feedwater. The high-pressure cylinder 12 of the turbine is connected to the reheat steam inlet of the coal-fired boiler 11 via a steam loop. Part of the steam in the high-pressure cylinder 12 flows back to the coal-fired boiler 11, is heated to form reheat steam, and is then transported to the intermediate-pressure cylinder 13 of the turbine to perform work.

[0027] The feedwater pipeline between the No. 1 high-pressure heater 15 and the coal-fired boiler 11 is connected to the combustion chamber 7 via a first feedwater branch. A booster pump 30 is installed in the first feedwater branch. A portion of the feedwater from the No. 1 high-pressure heater 15 enters the combustion chamber 7 to absorb the heat released by the combustion of hydrogen and oxygen, thereby generating more high-temperature, high-pressure steam in the combustion chamber 7, which is then fed into the hydrogen gas turbine 8 to perform work. A second heat exchanger 9 and a third heat exchanger 10 are installed between the hydrogen gas turbine 8 and the turbine unit. The steam discharged from the hydrogen gas turbine 8 is diverted into the second and third heat exchangers 9 and 10 for heat exchange before merging and being delivered to the intermediate-pressure cylinder 13 of the turbine to perform work. The feedwater pipeline between the No. 1 high-pressure heater 15 and the coal-fired boiler 11 supplies water to the second heat exchanger 9 via the second feedwater branch. After heat exchange with the steam discharged from the hydrogen gas turbine 8, the water is delivered to the high-pressure cylinder 12 of the turbine to perform work. The steam circuit between the high-pressure cylinder 12 of the steam turbine and the coal-fired boiler 11 partially supplies steam to the third heat exchanger 10 through the steam supply branch. After exchanging heat with the steam discharged from the hydrogen gas turbine 8, the steam is then delivered to the intermediate-pressure cylinder 13 of the steam turbine to perform work. By coupling the steam turbine unit of the coal-fired power generation system with the hydrogen gas turbine power generation system, when the coal-fired power generation system increases its load, the steam output from the hydrogen gas turbine power generation system can be used to supplement the steam turbine unit to perform work.

[0028] In this embodiment, the heat recovery system includes a first heat exchanger 4, a fourth heat exchanger 25, a hot water tank 5, and a cold water tank 6. The first heat exchanger 4 and the fourth heat exchanger 25 are connected in series via pipelines to form a circulation loop. In this loop, the cold water tank 6 is located on the feed water side pipeline from the fourth heat exchanger 25 to the first heat exchanger 4, and the hot water tank 5 is located on the feed water side pipeline from the first heat exchanger 4 to the fourth heat exchanger 25. The first heat exchanger 4 is connected in series with the proton exchange membrane electrolyzer 1, allowing the outlet water from the proton exchange membrane electrolyzer 1 to enter the first heat exchanger 1 for heat exchange. The fourth heat exchanger 25 is connected in parallel with low-pressure heaters 21 (#3) and 22 (#4), allowing at least a portion of the feed water to enter the fourth heat exchanger 25 for heat exchange. The cold water in the circulation loop is stored in the cold water tank 6, and after heat exchange with the outlet water from the proton exchange membrane electrolyzer 1, it becomes hot water, which is then stored in the hot water tank 5. When a coal-fired power generation system needs to increase its load to participate in peak shaving, the hot water stored in the hot water tank 5 enters the fourth heat exchanger 25 and exchanges heat with part of the feedwater at the outlet of the condensate pump 23, so as to realize the heating of feedwater to replace steam extraction, thereby improving the power output and load adjustment flexibility of the coal-fired power generation system.

[0029] When this integrated power generation system combining an electrolyzer, hydrogen gas turbine, and coal-fired power plant is applied, the following steps are included: 1. Determine if there is excess electricity in the renewable energy power generation system. "Excess electricity" should be understood as electricity that the renewable energy power generation system cannot consume within a certain period (e.g., one day). When excess electricity exists, control the circuit between the renewable energy power generation system and electrode 1 of the proton exchange membrane electrolyzer to produce hydrogen and oxygen by electrolyzing water using the electricity from the renewable energy power generation system, and then store them. 2. When the coal-fired power generation system needs to increase its load to participate in peak shaving, the hydrogen and oxygen produced by the electrolysis system are transported to the combustion chamber 7 for combustion, heating a portion of the extracted coal-fired boiler feedwater to generate high-temperature and high-pressure steam, which is then transported to the hydrogen gas turbine 8 for power generation; and the steam discharged from the hydrogen gas turbine 8 is supplemented to the steam turbine unit after heat exchange, together with the steam transported by the coal-fired boiler 11 to drive the steam turbine unit to do work; 3. When the coal-fired power generation system needs to increase its load to participate in peak shaving, the hot water stored in the hot water tank 5 can also be transported to the fourth heat exchanger 25 and part of the feedwater at the outlet of the condensate pump 23 for heat exchange, thereby reducing or replacing the steam extraction from the turbine unit by the low-pressure heater group.

[0030] This embodiment combines an electrolysis system with a renewable energy power generation system. By electrolyzing water in a proton exchange membrane electrolyzer 1 to produce hydrogen, the excess electricity that the renewable energy power generation system cannot absorb is utilized. High-purity hydrogen is produced and can be further reused, thus solving the problem of "wind and electricity curtailment" in existing renewable energy power generation systems due to the inability to absorb the excess electricity.

[0031] This embodiment further integrates a hydrogen gas turbine power generation system and a coal-fired power generation system. On one hand, the high-temperature, high-pressure steam generated by the combustion of hydrogen and oxygen drives the hydrogen gas turbine 8 to generate electricity, improving the utilization rate of renewable energy power generation. On the other hand, when the coal-fired power generation system needs to rapidly increase its load to participate in peak shaving, the steam from the hydrogen gas turbine power generation system can be used to supplement the work done by the turbine unit of the coal-fired power generation system. This increases the amount of steam entering the turbine unit of the coal-fired power generation system to do work, thereby increasing the power output of the coal-fired power generation system and assisting the coal-fired power generation system in increasing its load. By utilizing the fast response speed of the hydrogen gas turbine power generation system, the shortcomings of the coal-fired power generation system itself—slow load increase rate and insufficient operational flexibility—are compensated for, improving the start-up speed of the coal-fired power generation system in increasing its load and enhancing the system's operational flexibility.

[0032] This embodiment further incorporates a heat recovery system. This system, through heat exchange, can further reuse the heat from the outlet water of the proton exchange membrane electrolyzer to heat the condensate from the turbine's exhaust steam, thereby further improving the utilization rate of renewable energy power generation. On the other hand, when the coal-fired power generation system needs to increase its load to participate in peak shaving, the heat recovery system can exchange heat with part of the feedwater, which helps reduce or replace the extraction of steam from the turbine by the low-pressure heater unit, thus improving the power output and load increase flexibility of the coal-fired power generation system.

Claims

1. A combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant, comprising: A coal-fired power generation system, comprising a coal-fired boiler, a steam turbine unit, a low-pressure heater unit, and a high-pressure heater unit, wherein the steam turbine unit is connected to the coal-fired boiler and driven by steam output from the coal-fired boiler, and the condensate from the exhaust steam of the steam turbine unit is supplied to the coal-fired boiler at least partially through the low-pressure heater unit and the high-pressure heater unit in sequence. Its characteristic is that it further includes: An electrolysis system, comprising a proton exchange membrane electrolyzer, wherein the electrodes of the proton exchange membrane electrolyzer are electrically connected to a renewable energy power generation system and utilize the electricity generated by the renewable energy power generation system to electrolyze water to produce hydrogen; A hydrogen gas turbine power generation system, comprising a combustion chamber and a hydrogen gas turbine connected to each other, wherein the combustion chamber is connected to an electrolysis system and generates steam by burning hydrogen produced by electrolysis to drive the hydrogen gas turbine to generate electricity; The steam turbine unit is connected to the hydrogen gas turbine power generation system, and the coal-fired power generation system uses the steam output from the hydrogen gas turbine power generation system to supplement the steam turbine unit when the load increases.

2. The integrated power generation system comprising an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to claim 1, characterized in that: It also includes a heat recovery system, which uses a heat exchange system to transfer the heat from the outlet water of the proton exchange membrane electrolyzer to the condensate from the exhaust steam at the end of the turbine unit.

3. The integrated power generation system comprising an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to claim 2, characterized in that: The heat recovery system includes a first heat exchanger and a fourth heat exchanger connected in series to form a circulating loop. The first heat exchanger is connected in series with a proton exchange membrane electrolyzer, and the outlet water in the proton exchange membrane electrolyzer can enter the first heat exchanger for heat exchange. The fourth heat exchanger is connected in parallel with at least part of the low-pressure heaters of the low-pressure heater group, and at least part of the condensate from the exhaust steam at the end of the turbine unit can enter the fourth heat exchanger for heat exchange.

4. The integrated power generation system of an electrolyzer, hydrogen gas turbine, and coal-fired power plant according to claim 3, characterized in that: The circulation loop between the first heat exchanger and the fourth heat exchanger is also equipped with a cold water tank and a hot water tank.

5. A combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to any one of claims 1-4, characterized in that: The hydrogen delivery pipeline between the proton exchange membrane electrolyzer and the combustion chamber is equipped with a hydrogen storage tank and a first compressor, and the oxygen delivery pipeline between the proton exchange membrane electrolyzer and the combustion chamber is equipped with an oxygen storage tank and a second compressor.

6. A combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to any one of claims 1-4, characterized in that: The water supply pipeline between the high-pressure heater group and the coal-fired boiler is connected to the combustion chamber through a first water supply branch, and the first water supply branch is equipped with a booster pump.

7. A combined power generation system integrating an electrolyzer, a hydrogen gas turbine, and a coal-fired power plant according to any one of claims 1-4, characterized in that: The turbine unit includes a high-pressure cylinder, an intermediate-pressure cylinder, and a low-pressure cylinder. The coal-fired boiler is connected to the high-pressure cylinder and the intermediate-pressure cylinder via pipelines. The intermediate-pressure cylinder and the low-pressure cylinder are connected via pipelines. A second heat exchanger and a third heat exchanger are provided between the hydrogen gas turbine and the turbine unit. The steam discharged from the hydrogen gas turbine is diverted into the second and third heat exchangers for heat exchange and is then delivered to the intermediate-pressure cylinder. The feedwater pipeline between the high-pressure heater group and the coal-fired boiler supplies water to the second heat exchanger through a second feedwater branch and exchanges heat with the steam discharged from the hydrogen gas turbine to form steam, which is then delivered to the high-pressure cylinder. The steam circuit between the high-pressure cylinder and the coal-fired boiler supplies steam to the third heat exchanger through a steam supply branch and exchanges heat with the steam discharged from the hydrogen gas turbine before being delivered to the intermediate-pressure cylinder.

8. The integrated power generation system of an electrolyzer, hydrogen gas turbine, and coal-fired power plant according to claim 7, characterized in that: The high-pressure cylinder of the steam turbine is connected to the main steam outlet of the coal-fired boiler via a pipeline, the intermediate-pressure cylinder of the steam turbine is connected to the reheat steam outlet of the coal-fired boiler via a pipeline, and the high-pressure cylinder of the steam turbine is connected to the reheat steam inlet of the coal-fired boiler via a steam circuit.

9. A combined power generation method, employing the combined power generation system of an integrated electrolyzer, hydrogen gas turbine, and coal-fired power plant as described in any one of claims 1-8, characterized in that, Includes the following steps: Determine whether there is excess power in the renewable energy power generation system. If there is excess power, control the circuit between the renewable energy power generation system and the proton exchange membrane electrolyzer electrode to conduct and use the electricity from the renewable energy power generation system to electrolyze water to produce hydrogen. When the coal-fired power generation system needs to increase its load, the hydrogen produced by the electrolysis system is transported to the combustion chamber for combustion to generate steam, and then the steam generated by the hydrogen combustion is transported to the hydrogen gas turbine to drive the hydrogen gas turbine to generate electricity. The steam discharged from the hydrogen gas turbine is transported to the steam turbine unit, and together with the steam transported from the coal-fired boiler, the steam turbine unit is driven.

10. A combined power generation method according to claim 9, characterized in that: The heat from the outlet water of the proton exchange membrane electrolyzer is used to heat the condensate from the exhaust steam at the end of the steam turbine of the coal-fired power generation system through heat exchange.

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