Peak shaving system coupled with electrolyzed water hydrogen storage and gas-steam combined cycle unit
By combining solid oxide electrolytic technology and heat exchange units on the gas-steam combined cycle generator set, the demand for high-temperature environment during the electrolytic hydrogen production process is solved, and efficient hydrogen storage and peak shaving effects are achieved, avoiding the problems of low efficiency and high cost in the existing technology.
Patent Information
- Application Number
- CN202311386472.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-24
- Publication Date
- 2025-04-25
AI Technical Summary
In the prior art, the application of solid oxide electrolytic water technology in power plants is limited by the demand for high temperature and continuous water supply, which makes it difficult to implement, and alkaline electrolytic water and proton exchange membrane electrolytic water technology have problems of low efficiency and high cost.
A peak regulating system is developed that is coupled with electrolytic water hydrogen storage and gas steam combined cycle unit. It uses solid oxide electrolytic water technology combined with gas steam combined cycle generator unit to heat the gas turbine exhaust through a heat exchange unit to provide high-temperature water vapor to be electrolyzed, solving the high-temperature environment needs in the process of electrolyzed water hydrogen production.
It has realized the efficient application of solid oxide electrolytic technology on gas-steam combined cycle generator sets, avoiding the need for additional electrolytic water, improving energy utilization, reducing operating costs, and solving the problem of peak shaving.
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Figure CN119878337A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of energy conversion and physical energy storage technology, and in particular to a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit. Background Art
[0002] With the rapid development of my country's economy, energy demand and carbon emissions have increased significantly. According to the "dual carbon" concept of carbon peak and carbon neutrality, it is inevitable to build a clean, low-carbon and efficient energy system and a new power system based on new energy. The new power system is a hub platform for achieving the "dual carbon" goals. To achieve the "dual carbon" goals, it is fundamentally necessary to reduce fossil energy consumption and increase non-fossil energy consumption.
[0003] Compared with traditional coal-fired power generation units, gas-steam combined cycle power generation units have the advantages of short construction period, small footprint, flexible operation mode, etc., coupled with the diversity of available fuels, it can not only improve the efficiency of primary energy utilization, but also reduce carbon emissions from the source, with good energy saving, environmental protection and social benefits, and is the mainstream trend of future power plants. Hydrogen, as a clean secondary energy with no carbon emissions and high calorific value, is widely used in various energy fields. With the rapid development of hydrogen energy production, storage, and transmission technologies, hydrogen energy supply has gradually become popular. In the process of hydrogen production by electrolysis of water, the excess electricity converted from renewable energy in the "valley time" of the unit can be converted into hydrogen for storage. Through energy storage and hydrogen-electricity coupling, the energy in hydrogen can be converted into electrical energy, realizing long-term large-scale planning and optimization of excess energy scheduling, thereby achieving the purpose of peak regulation.
[0004] The gas-steam combined cycle unit uses natural gas as fuel input, and generates high-temperature gas through combustion reaction to drive the turbine to rotate and generate electricity. At the same time, the exhaust gas from the turbine heats the water in the waste heat boiler to drive the steam turbine to rotate and generate electricity. This series of processes is based on the premise that the gas turbine has sufficient fuel input. When the purity of natural gas decreases or the fuel supply is insufficient, it will affect the power generation efficiency of the gas-steam combined cycle unit. Therefore, energy storage and peak regulation are particularly important. At present, hydrogen energy storage is the cleanest secondary energy source. Coupling hydrogen energy storage with power generation is the development trend of future peak regulation systems. There are currently three main ways to electrolyze water, namely alkaline water electrolysis, proton exchange membrane water electrolysis, and solid oxide water electrolysis technology. Alkaline water electrolysis technology has low efficiency in hydrogen production and there is the problem of alkali seepage and environmental pollution; proton exchange membrane water electrolysis technology has high efficiency in hydrogen production but requires precious metals such as Ir and Ru as catalysts, resulting in high processing costs; solid oxide water electrolysis technology has high efficiency in hydrogen production and can use inexpensive nickel-based electrodes, but its extremely high operating temperature makes it difficult to implement. If solid oxide water electrolysis is used to produce hydrogen, a large amount of electricity must be consumed to heat the water to reach the electrolysis temperature. A large amount of electrolyzed water should also be added during the electrolysis process. High temperature and continuous water supply have hindered the development of this technology in power plants.
[0005] Therefore, this application urgently needs to develop a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit. The system applies solid oxide water electrolysis technology to a gas-steam combined cycle generator unit to achieve the purpose of peak regulation through energy storage and hydrogen-electricity coupling. Summary of the invention
[0006] The purpose of the present application is to provide a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit, which applies solid oxide water electrolysis technology to a gas-steam combined cycle generator unit to achieve the purpose of peak-shaving through energy storage and hydrogen-electricity coupling.
[0007] The present application provides a peak load regulation system of water electrolysis hydrogen storage coupled with a gas-steam combined cycle unit, comprising: a gas turbine power generation unit, a waste heat boiler power generation unit, a heat exchange unit, and a solid oxide water electrolysis hydrogen production unit; wherein the heat exchange unit comprises an electric heater and a heat exchanger,
[0008] The waste heat boiler power generation unit is used to receive a first portion of gas turbine exhaust with a first temperature discharged from the gas turbine power generation unit and provide a first portion of steam turbine exhaust with a second temperature to the heat exchanger; the electric heater is used to receive a second portion of gas turbine exhaust with a first temperature discharged from the gas turbine power generation unit, and reheat the second portion of gas turbine exhaust, thereby providing a third gas turbine exhaust with a third temperature to the heat exchanger, and the heat exchanger is configured to perform heat exchange between the first portion of steam turbine exhaust and the third gas turbine exhaust, and provide the solid oxide water electrolysis hydrogen production unit with water vapor to be electrolyzed at the temperature required by the solid oxide water electrolysis hydrogen production unit.
[0009] In another preferred embodiment, the water vapor to be electrolyzed is in gaseous state.
[0010] In another preferred example, the second temperature is lower than the first temperature.
[0011] In another preferred example, the third temperature is greater than the second temperature and greater than the first temperature.
[0012] In another preferred embodiment, the first portion of gas turbine exhaust, the second portion of gas turbine exhaust and the third portion of gas turbine exhaust are all flue gas, and the flue gas is in a gaseous state.
[0013] In another preferred example, the first part of steam turbine exhaust steam is water vapor, and the water vapor is a mixture of gas and liquid.
[0014] In another preferred example, the heat exchange unit is located downstream of the gas turbine power generation unit.
[0015] In another preferred example, the heat exchange unit is located between the gas turbine power generation unit and the waste heat boiler power generation unit.
[0016] In another preferred example, the heat exchanger has a first channel and a second channel, the first channel is configured to receive the first part of the steam turbine exhaust, and the second channel is configured to receive the third gas turbine exhaust.
[0017] In another preferred example, the solid oxide water electrolysis hydrogen production unit is connected to the first channel fluid of the heat exchanger.
[0018] In another preferred example, the system also includes a hydrogen energy storage unit, which is configured to receive and store hydrogen electrolyzed by the solid oxide water electrolysis hydrogen production unit, and when the power load is high, the hydrogen energy storage unit is configured to provide the stored hydrogen as fuel to the gas turbine power generation unit.
[0019] In another preferred example, the hydrogen energy storage unit is further configured to generate electricity using the stored hydrogen.
[0020] In another preferred example, the gas turbine power generation unit includes a compressor, a combustion chamber, a turbine and a first generator.
[0021] In another preferred example, the compressor is configured to compress air and provide the compressed air to the combustion chamber, and the combustion chamber is configured to receive natural gas and burn the received natural gas and compressed air, thereby driving the turbine to work and drive the first generator to generate electricity.
[0022] In another preferred example, the combustion chamber is also fluidically connected to the hydrogen energy storage unit.
[0023] In another preferred example, the waste heat boiler power generation unit includes a boiler, a steam turbine, a condenser, a condensate pump and a second generator.
[0024] In another preferred example, the inlet of the boiler is fluidly connected to the exhaust port of the gas turbine power generation unit, and is used to receive the first part of the gas turbine exhaust so that the first part of the gas turbine exhaust heats the water in the boiler drum, and then provides water vapor to the steam turbine, thereby driving the steam turbine to do work and driving the second generator to generate electricity.
[0025] In another preferred example, the outlet of the steam turbine is fluidly connected to the heat exchanger and the condenser.
[0026] In another preferred example, the condenser is located downstream of the steam turbine, receiving a second portion of steam turbine exhaust steam discharged from the steam turbine, and the condenser is configured to cool the received second portion of steam turbine exhaust steam into condensate, and the condensate is provided to the boiler through the condensate pump located downstream of the condenser.
[0027] In another preferred example, the boiler is located downstream of the condensate pump.
[0028] In another preferred example, the boiler is also connected to the heat exchanger, so as to receive the fourth gas turbine exhaust gas with a certain temperature flowing out from the second channel of the heat exchanger.
[0029] In another preferred example, the hydrogen energy storage unit includes a hydrogen compressor, a hydrogen storage tank, and an outlet regulating valve, wherein the hydrogen compressor is fluidically connected to the solid oxide water electrolysis hydrogen production unit, the hydrogen storage tank is located downstream of the hydrogen compressor, and the outlet regulating valve is located downstream of the hydrogen storage tank.
[0030] In another preferred example, the outlet regulating valve is in fluid communication with the gas turbine power generation unit.
[0031] In another preferred example, the peak shaving system further includes an expander and a third generator, wherein the expander is located downstream of the outlet regulating valve, and the outlet of the expander is fluidically connected to the gas turbine power generation unit.
[0032] In another preferred example, the combustion chamber is fluidly connected to the outlet regulating valve.
[0033] In another preferred example, the combustion chamber is fluidly connected to the expander of the hydrogen energy storage unit.
[0034] In another preferred example, the solid oxide water electrolysis hydrogen production unit includes an electrolysis electrode, a water electrolysis cell and an AC / DC converter.
[0035] In another preferred example, the water electrolysis tank is connected to the first channel of the heat exchanger and is used to receive the water vapor to be electrolyzed at a temperature required by the solid oxide water electrolysis hydrogen production unit.
[0036] In another preferred example, the water electrolyzer is also connected to the compressor of the gas turbine power generation unit and provides electrolyzed oxygen to the compressor.
[0037] In another preferred embodiment, the factory electricity is converted into direct current required for water electrolysis by the AC-DC converter.
[0038] A large number of technical features are recorded in the specification of this application, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above-mentioned invention content of this application, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. It should be understood that the drawings described below are only some implementation examples of the present invention, and ordinary technicians in this field can also obtain other implementation examples based on these drawings without paying creative work.
[0040] Figure 1 It is a schematic diagram of a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit according to an embodiment of the present application.
[0041] In the accompanying drawings, the markings are as follows:
[0042] 1- Compressor
[0043] 2- Combustion Chamber
[0044] 3-Turbine
[0045] 4-Electric heater
[0046] 5-Plate Heat Exchanger
[0047] 6-Waste heat boiler
[0048] 7- Steam Turbine
[0049] 8-Condenser
[0050] 9-Condensate pump
[0051] 10-Water electrolyzer
[0052] 11-Hydrogen compressor
[0053] 12-Hydrogen storage container
[0054] 13-Outlet regulating valve
[0055] 14-Expander DETAILED DESCRIPTION
[0056] Through extensive and in-depth research, the inventor has developed for the first time a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit. The system can apply solid oxide water electrolysis technology to a gas-steam combined cycle generator unit by setting a gas turbine power generation unit, a waste heat boiler power generation unit, a heat exchange unit, a solid oxide water electrolysis hydrogen production unit, and a hydrogen energy storage unit. The purpose of peak regulation is achieved through energy storage and hydrogen-electricity coupling. The peak-shaving system of the present application utilizes the flue gas discharged from the gas turbine to heat the exhaust steam of the steam turbine. While solving the water source, it also solves the high-temperature environment required by the electrolysis ring. Specifically, the exhaust gas of the gas turbine is used as an energy source to heat the steam discharged from the low-pressure exhaust cylinder of the steam turbine. The system has the advantages of utilizing the initial temperature of the steam to avoid the extra energy consumption in the process of heating water to steam, and the flue gas discharged from the gas turbine has a high temperature. The temperature of the flue gas can be easily raised to the temperature of solid oxide water electrolysis hydrogen production by electric heating, which saves a lot of electricity-consuming water heating process.
[0057] the term
[0058] As used herein, "communication," and "communicatively connected" are used interchangeably.
[0059] As used herein, "waste heat boiler" and "boiler" are used interchangeably.
[0060] It should be noted that in the application documents of this patent, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the application documents of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements. Expressions such as multiple, multiple, and multiple include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.
[0061] In the present invention, all directional indications (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.
[0062] This application has at least one of the following advantages
[0063] (a) The peak-shaving system of the present application, which couples water electrolysis hydrogen storage with a gas-steam combined cycle unit, uses the new technology of solid oxide water electrolysis on a gas-steam combined cycle generator unit to achieve the purpose of peak-shaving through energy storage and hydrogen-electricity coupling;
[0064] Optionally, (b) the peak-shaving system of the electrolytic water hydrogen storage coupled with the gas-steam combined cycle unit of the present application provides the ultra-high temperature electrolytic water required for the solid oxide electrolysis water hydrogen production through the gas-steam combined cycle unit; that is, the exhaust steam of the steam turbine is used as the water source for the electrolytic water, and the exhaust steam of the gas turbine is used to heat the steam, and the two complement each other to provide the necessary conditions for reaching the temperature required for the solid oxide electrolysis water, thereby improving the energy utilization rate; that is, the problem of additional supplementary electrolytic water is solved, the exhaust steam of the steam turbine is used as the initial water source, and it also has the characteristics of water recycling;
[0065] Optionally, (c) the peak load regulation system of the present application utilizes solid oxide water electrolysis technology, which can avoid the problem of low efficiency of hydrogen production by electrolyzing water with alkaline solution and the pollution of the environment by alkaline solution on the one hand; on the other hand, it can avoid the problem of high cost of using precious metal catalysts by electrolyzing water with proton exchange membrane;
[0066] Optionally, (d) the peak-shaving system of the present application, which is coupled with the electrolytic water hydrogen storage and the gas-steam combined cycle unit, uses the exhaust gas of the gas turbine as energy to heat the steam discharged from the low-pressure exhaust cylinder of the steam turbine, and has the following advantages: on the one hand, the steam has an initial temperature, which avoids the extra energy consumption in the process of heating water to steam; on the other hand, the flue gas discharged by the gas turbine has a relatively high temperature, and the temperature of the flue gas can be easily raised to the temperature of solid oxide electrolysis water hydrogen production by electric heating, which saves a lot of electricity-consuming water heating process;
[0067] Optionally, (e) in terms of energy storage, the peak-shaving system of the present application, which couples water electrolysis hydrogen storage with a gas-steam combined cycle unit, compresses the hydrogen generated by water electrolysis through a compressor, and stores the compressed gas in a container. When fuel needs to be supplemented or a higher power generation load needs to be driven, the hydrogen stored in the container (hydrogen storage container) can be released. In addition, the compressed hydrogen has a certain amount of energy. By installing an expander behind the container (hydrogen storage container), the high-pressure hydrogen can drive the expander to rotate and generate electricity while entering the fuel inlet of the gas turbine, thereby improving energy utilization;
[0068] Optionally, (f) when the power load is low, the peak load shaving system of the present application can compress the generated hydrogen for energy storage; when the power load is high, on the one hand, the stored hydrogen is released through the regulating valve to drive the expander to rotate and generate electricity; on the other hand, the released hydrogen is sent to the combustion chamber as fuel as fuel supply to improve the power generation efficiency;
[0069] Optionally, (g) the oxygen generated by the peak-shaving system of the present application during the process of producing hydrogen by electrolysis of water is fed into the inlet of the compressor in real time to increase the concentration of oxygen participating in the combustion reaction and improve the combustion efficiency.
[0070] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.
[0071] Peak load regulation system of water electrolysis hydrogen storage coupled with gas-steam combined cycle unit
[0072] See also Figure 1 The peak load regulation system of the present application, which is a combination of water electrolysis hydrogen storage and a gas-steam combined cycle unit, comprises: a gas turbine power generation unit, a waste heat boiler power generation unit, a heat exchange unit, a solid oxide water electrolysis hydrogen production unit and a hydrogen energy storage unit; wherein the heat exchange unit comprises an electric heater 4 and a heat exchanger 5,
[0073] The waste heat boiler power generation unit is used to receive the first part of the gas turbine exhaust gas with a first temperature discharged from the gas turbine power generation unit and provide the first part of the steam turbine exhaust gas with a second temperature to the heat exchanger 5; the electric heater 4 is used to receive the second part of the gas turbine exhaust gas with a first temperature of the gas turbine power generation unit, and reheat the second part of the gas turbine exhaust gas, thereby providing the third gas turbine exhaust gas with a third temperature to the heat exchanger 5, and the heat exchanger 5 is configured to heat exchange the first part of the steam turbine exhaust gas and the third gas turbine exhaust gas and provide the solid oxide water electrolysis hydrogen production unit with the water vapor to be electrolyzed at the temperature required by the solid oxide water electrolysis hydrogen production unit, thereby providing the solid oxide water electrolysis hydrogen production unit with an initial water source, which has the characteristics of water recycling. In one embodiment, the second temperature is less than the first temperature. In one embodiment, the third temperature is greater than the first temperature and greater than the second temperature. In one embodiment, the temperature required for the solid oxide water electrolysis hydrogen production unit is between 700°C and 850°C. In one embodiment, the first part of the gas turbine exhaust, the second part of the gas turbine exhaust and the third gas turbine exhaust are flue gas, which is in a gaseous state, and the first part of the steam turbine exhaust is water vapor, which is a mixture of gas and liquid. In one embodiment, the water vapor to be electrolyzed is in a gaseous state.
[0074] Preferably, the heat exchange unit is located downstream of the gas turbine power generation unit. Preferably, the heat exchange unit is located between the gas turbine power generation unit and the waste heat boiler power generation unit, and the solid oxide water electrolysis hydrogen production unit and the hydrogen energy storage unit are arranged on the side of the gas turbine power generation unit, the heat exchange unit and the waste heat boiler power generation unit, so that the structure is compact and the fluid flows smoothly during the operation of the entire system.
[0075] In one embodiment, the exhaust outlet of the gas turbine power generation unit is connected to the heat exchange unit and the waste heat boiler power generation unit, wherein the waste heat boiler power generation unit receives a first portion of the gas turbine exhaust having a first temperature, and the electric heater 4 of the heat exchange unit receives a second portion of the gas turbine exhaust having the first temperature.
[0076] In one embodiment, the heat exchanger 5 has a first channel and a second channel, the first channel is configured to receive the first portion of steam turbine exhaust, and the second channel is configured to receive the third gas turbine exhaust. The solid oxide water electrolysis hydrogen production unit is in fluid communication with the first channel of the heat exchanger 5, and the solid oxide water electrolysis hydrogen production unit receives the water vapor to be electrolyzed at a temperature required by the solid oxide water electrolysis hydrogen production unit flowing out of the first channel of the heat exchanger 5.
[0077] In one embodiment, the gas turbine power generation unit includes a compressor 1, a combustion chamber 2, a turbine 3 and a first generator. The compressor 1 is configured to compress air and provide compressed air to the combustion chamber 2, and the combustion chamber 2 is configured to receive natural gas and provide the received natural gas and compressed air for combustion, thereby driving the turbine 3 to work and drive the first generator to generate electricity. Preferably, the combustion chamber 2 is also fluidly connected to the hydrogen energy storage unit to receive hydrogen stored in the hydrogen energy storage unit. When fuel needs to be supplemented or a higher power generation load needs to be driven, the hydrogen stored in the hydrogen energy storage unit is released to the combustion chamber 2 to improve the combustion efficiency and achieve the purpose of peak load regulation.
[0078] In one embodiment, the waste heat boiler power generation unit includes a boiler 6, a steam turbine 7, a condenser 8, a condensate pump 9 and a second generator. The inlet of the boiler 6 is in fluid communication with the exhaust port of the gas turbine power generation unit, and is used to receive the first part of the gas turbine exhaust so that the first part of the gas turbine exhaust heats the water in the drum of the boiler 6, and then provides water vapor to the steam turbine 7, thereby driving the steam turbine 7 to do work and drive the second generator to generate electricity.
[0079] Preferably, the outlet of the steam turbine 7 is in fluid communication with the heat exchanger 5 and the condenser 8, and the boiler 6 is located downstream of the condensate pump 9. The first channel of the heat exchanger 5 is configured to receive the first part of the steam turbine exhaust steam, and the condenser 8 is located downstream of the steam turbine 7 to receive the second part of the steam turbine exhaust steam discharged from the steam turbine 7. The condenser 8 is configured to cool the received second part of the steam turbine exhaust steam into condensed water, and the condensed water is provided to the boiler 6 through the condensate pump 9 located downstream of the condenser 8, which has the characteristics of water recycling. Preferably, the boiler 6 is also in communication with the heat exchanger 5, so as to receive the fourth gas turbine exhaust gas with a certain temperature flowing out of the second channel of the heat exchanger 5, and the fourth gas turbine exhaust gas can be used to heat the water in the drum of the boiler 6.
[0080] In one embodiment, the solid oxide water electrolysis hydrogen production unit comprises an electrolysis electrode, a water electrolysis cell 10 and an AC / DC converter, and the plant electricity is converted into the DC power required for water electrolysis by the AC / DC converter. The water electrolysis cell 10 is connected to the first channel of the heat exchanger 5 and is used to receive the water vapor to be electrolyzed at the required temperature of the solid oxide water electrolysis hydrogen production unit.
[0081] Preferably, the water electrolyzer 10 is also connected to the compressor 1 of the gas turbine power generation unit, and provides electrolyzed oxygen to the compressor 1, thereby achieving full utilization of energy.
[0082] In one embodiment, the hydrogen energy storage unit is configured to receive and store hydrogen electrolyzed by the solid oxide water electrolysis hydrogen production unit, and when the power load is high, the hydrogen energy storage unit is configured to provide the stored hydrogen as fuel to the gas turbine power generation unit. Preferably, the hydrogen energy storage unit is also configured to use the stored hydrogen to generate electricity.
[0083] In one embodiment, the hydrogen energy storage unit includes a hydrogen compressor 11, a hydrogen storage 12, and an outlet regulating valve 13, wherein the hydrogen compressor 11 is fluidly connected to the solid oxide water electrolysis hydrogen production unit, the hydrogen storage 12 is located downstream of the hydrogen compressor 11, and the outlet regulating valve 13 is located downstream of the hydrogen storage 12. Preferably, the outlet regulating valve 13 is fluidly connected to the combustion chamber 2 of the gas turbine power generation unit, and when the power load is high, the stored hydrogen is provided to the combustion chamber 2, thereby achieving the purpose of peak load regulation. Preferably, the peak load regulation system also includes an expander 14 and a third generator, the expander 14 is located downstream of the outlet regulating valve 13, and the outlet of the expander 14 is fluidly connected to the combustion chamber 2 of the gas turbine power generation unit, so that the high-pressure hydrogen can drive the expander to rotate and generate electricity while entering the fuel inlet of the gas turbine, thereby improving the utilization rate of energy.
[0084] In order to make the objectives, technical solutions and advantages of the present invention more clear, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.
[0085] Example
[0086] See also Figure 1 The present application provides a peak-shaving system that couples water electrolysis hydrogen storage with a gas-steam combined cycle unit.
[0087] The peak-shaving system consists of four parts, namely, a gas turbine power generation unit, a waste heat boiler power generation unit, a heat exchange unit, a water electrolysis hydrogen production unit and a hydrogen energy storage unit.
[0088] The gas turbine power generation unit includes a compressor 1, a combustion chamber 2, a turbine 3 and a first generator. The compressor compresses the air and sends it into the combustion chamber to react chemically with the natural gas, generating high-temperature gas to drive the turbine to work and drive the generator to generate electricity. The flue gas outlet of the gas turbine power generation unit is respectively connected to the boiler 6 of the waste heat boiler power generation unit and the inlet of the electric heater 4 of the heat exchange unit, wherein most of the flue gas (i.e., the first part of the gas turbine exhaust gas with a first temperature) enters the waste heat boiler 6 to heat the water in the drum, thereby generating high-temperature and high-pressure steam to drive the steam turbine 7 to work and drive the second generator to generate electricity, and a part of the flue gas (i.e., the second part of the gas turbine exhaust gas with a first temperature) enters the electric heater 4 for reheating. The gas turbine power generation unit is connected to the other three parts as the core unit. The gas turbine power generation unit provides high-temperature flue gas (i.e., high-temperature gas turbine exhaust gas) to the heat exchange unit and the waste heat boiler power generation unit, and the hydrogen energy storage unit and the water electrolysis hydrogen production unit send the hydrogen and oxygen generated by water electrolysis into the compressor 1 and the combustion chamber 2 of the gas turbine power generation unit to participate in the combustion reaction.
[0089] The waste heat boiler power generation unit includes a waste heat boiler 6, a steam turbine 7, a condenser 8, a condensate pump 9 and a second generator. The flue gas discharged from the gas turbine power generation unit (i.e., the second part of the gas turbine exhaust gas with the first temperature) heats the water in the drum of the waste heat boiler 6, generates high-temperature and high-pressure steam to drive the steam turbine 7 to work, and the exhaust steam that has completed the work is discharged from the outlet of the low-pressure cylinder, enters the condenser 8 and is cooled into condensate, and the condensate is pumped back to the boiler 6 through the condensate pump 9, as a steam-water cycle, that is, the second part of the steam turbine exhaust gas enters the condenser 8 and is cooled into condensate, and the condensate is pumped back to the boiler 6 through the condensate pump 9. In addition, the outlet end (the outlet end of the second channel) of the heat exchanger 5 in the heat exchange unit is connected to the waste heat boiler 6, and the flue gas after heat exchange (i.e., the fourth gas turbine exhaust gas) still has a relatively high temperature and returns to the furnace to heat the water in the drum.
[0090] The heat exchange unit includes an electric heater 4 and a plate heat exchanger 5. The electric heater 4 extracts part of the flue gas from the flue gas outlet of the gas turbine power generation unit (i.e., the second part of the gas turbine exhaust gas with the first temperature) for electrical reheating to obtain the third gas turbine exhaust gas with the third temperature, and sends it to the inlet end of the second channel of the heat exchanger 5. The heat exchanger 5 extracts part of the steam from the low-pressure exhaust outlet of the steam turbine 7 of the waste heat boiler power generation unit (i.e., the first part of the steam turbine exhaust gas), and sends it to the inlet end of the first channel of the heat exchanger. The steam (i.e., the first part of the steam turbine exhaust gas) absorbs heat through the third gas turbine exhaust gas with the third temperature in the heat exchanger 5, and generates high-temperature steam suitable for the temperature required for high-temperature solid oxide electrolysis (i.e., the water vapor to be electrolyzed at the temperature required by the solid oxide water electrolysis hydrogen production unit). Among them, the third temperature is greater than the first temperature and the second temperature.
[0091] The water electrolysis hydrogen production unit includes an electrolysis electrode, a water electrolyzer 10 and an AC / DC converter. Direct current, a water source required for water electrolysis and a relatively high temperature are the three elements of solid oxide graph water electrolysis hydrogen production. The factory electricity is converted into the direct current required for water electrolysis through an AC / DC converter. The water source for water electrolysis and the high temperature environment required for the reaction, and the high-temperature steam flowing out through the outlet of the first channel of the heat exchange unit plate heat exchanger 5 actually completes the process of heating the water source. Under the action of direct current, the high-temperature steam undergoes an electrolysis reaction in the water electrolyzer 10, and the hydrogen produced at the cathode and the oxygen produced at the anode are respectively sent to the inlet of the hydrogen compressor 11 of the hydrogen energy storage unit and the inlet of the compressor 1 of the gas turbine power generation unit. The oxygen produced by water electrolysis can enter the compressor 1 as part of the compressed air, thereby increasing the oxygen concentration in the chemical reaction and improving the combustion efficiency.
[0092] The hydrogen energy storage unit includes a hydrogen compressor 11, a hydrogen storage container 12, an outlet regulating valve 13, an expander 14 and a generator. The hydrogen generated by the water electrolysis hydrogen production unit is compressed into the hydrogen storage container 12 by the hydrogen compressor 11 for storage. When the power generation needs to be increased for peak regulation, the hydrogen stored in the container can be used as supplementary fuel through the outlet regulating valve 13 downstream of the hydrogen storage container 12 and sent to the fuel inlet of the gas turbine power generation unit to increase the power generation.
[0093] It can be seen that solid oxide water electrolysis is very compatible with gas-steam combined cycle power generation units. By making full use of the tail flue gas of the gas turbine as a heat source to heat the exhaust steam of the steam turbine, on the one hand, the problem of providing water sources for water electrolysis is solved, and on the other hand, the harsh conditions of high temperature required for the use of solid oxide water electrolysis are solved. In addition, the electrolyzed hydrogen can be stored as reserve energy and released when peak load regulation is required; oxygen is delivered to the compressor in real time to increase the oxygen concentration in the chemical reaction and improve combustion efficiency. This application fully embodies the "dual carbon" concept and provides a new peak load regulation idea.
[0094] All documents mentioned in this application are considered to be included in the disclosure of this application as a whole, so that they can be used as the basis for modification when necessary. In addition, it should be understood that after reading the above disclosure of this application, those skilled in the art can make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.
Claims
1. A peak load regulation system coupling water electrolysis hydrogen storage and gas steam combined cycle unit, characterized in that: include: A gas turbine power generation unit, a waste heat boiler power generation unit, a heat exchange unit, and a solid oxide water electrolysis hydrogen production unit; wherein the heat exchange unit includes an electric heater (4) and a heat exchanger (5), The waste heat boiler power generation unit is used to receive a first portion of gas turbine exhaust with a first temperature discharged from the gas turbine power generation unit and provide a first portion of steam turbine exhaust with a second temperature to the heat exchanger (5); the electric heater (4) is used to receive a second portion of gas turbine exhaust with a first temperature discharged from the gas turbine power generation unit and reheat the second portion of gas turbine exhaust, thereby providing a third gas turbine exhaust with a third temperature to the heat exchanger (5); the heat exchanger (5) is configured to perform heat exchange between the first portion of steam turbine exhaust and the third gas turbine exhaust, and provide the solid oxide water electrolysis hydrogen production unit with water vapor to be electrolyzed at the temperature required by the solid oxide water electrolysis hydrogen production unit.
2. The peak load regulation system according to claim 1, characterized in that: The heat exchanger (5) has a first channel and a second channel, the first channel being configured to receive the first portion of steam turbine exhaust steam, and the second channel being configured to receive the third gas turbine exhaust gas.
3. The peak load regulation system according to claim 2, characterized in that: The solid oxide water electrolysis hydrogen production unit is in fluid communication with the first channel of the heat exchanger (5).
4. The peak load regulation system according to claim 3, characterized in that: The system further comprises a hydrogen storage unit, which is configured to receive and store hydrogen electrolyzed by the solid oxide water electrolysis hydrogen production unit. When the power load is high, the hydrogen storage unit is configured to provide the stored hydrogen as fuel to the gas turbine power generation unit.
5. The peak load regulation system according to claim 4, characterized in that: The gas turbine power generation unit comprises a compressor (1), a combustion chamber (2), a turbine (3) and a first generator.
6. The peak load regulation system according to claim 5, characterized in that: The waste heat boiler power generation unit comprises a boiler (6), a steam turbine (7), a condenser (8), a condensate pump (9) and a second generator.
7. The peak load regulation system according to claim 6, characterized in that: The inlet of the boiler (6) is fluidly connected to the exhaust port of the gas turbine power generation unit and is used to receive the first part of the gas turbine exhaust so that the first part of the gas turbine exhaust heats the water in the steam drum of the boiler (6), thereby providing water vapor to the steam turbine (7), thereby driving the steam turbine (7) to do work and drive the second generator to generate electricity.
8. The peak load regulation system according to claim 7, characterized in that: The outlet of the steam turbine (7) is in fluid communication with the heat exchanger (5) and the condenser (8).
9. The peak load regulation system according to claim 8, characterized in that: The condenser (8) is located downstream of the steam turbine (7) and receives a second portion of steam turbine exhaust steam discharged from the steam turbine (7). The condenser (8) is configured to cool the received second portion of steam turbine exhaust steam into condensed water, and the condensed water is provided to the boiler (6) through the condensate pump (9) located downstream of the condenser (8).
10. The peak load regulation system according to claim 9, characterized in that: The hydrogen energy storage unit comprises a hydrogen compressor (11), a hydrogen storage tank (12), and an outlet regulating valve (13), wherein the hydrogen compressor (11) is fluidically connected to the solid oxide water electrolysis hydrogen production unit, the hydrogen storage tank (12) is located downstream of the hydrogen compressor (11), and the outlet regulating valve (13) is located downstream of the hydrogen storage tank (12).