Hydrogen stable supply and regional energy peak shifting comprehensive utilization method and system

Abstract

The invention discloses a hydrogen stable supply and regional energy peak shifting comprehensive utilization method and system.The method comprises the following steps that under the high-load working condition, green electricity or abandoned electricity is converted into heat energy through a heat storage system, and the heat energy is stored; hydrogen left after absorption of the waste heat utilization system is transmitted to the organic liquid hydrogen storage system and the spherical tank hydrogen storage system for storage; under the low-load working condition, after the circulating water system exchanges heat with the heat storage system through the steam pocket, circulating water is converted into steam, meanwhile, hydrogen is released through the hydrogen release system and the spherical tank hydrogen storage system together, and the released hydrogen and the steam are supplied to the waste heat utilization system together. The spherical tank hydrogen storage system and the organic liquid hydrogen storage system are coupled, on one hand, the starting time of the organic liquid hydrogen storage system can be compensated, and stable supply of downstream hydrogen is guaranteed; on the other hand, heat energy stored by the heat storage system is not consumed, the supply amount of the heat storage system can be maximized, and energy consumption at the valley electricity moment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wind-solar hydrogen production, and in particular to a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization. Background Art

[0002] Existing projects that use wind and solar power to produce hydrogen or upstream wind and solar power as the main energy sources are subject to the volatility of wind and solar power resources themselves, and the green electricity generated is unevenly distributed over time: when wind and solar power resources are sufficient, the entire plant is at full load, and there is sufficient electricity, heat and hydrogen energy, resulting in a portion of the excess electricity being discarded as green electricity; the excess heat energy cannot be effectively utilized or is used inefficiently.

[0003] When wind and solar resources are scarce, the load of the entire plant decreases, and excess energy needs to be consumed externally to insulate and heat the system and maintain the system's minimum load operation. Especially during peak electricity consumption periods, using peak grid electricity to heat the system is not only inefficient but also increases operating costs.

[0004] When using an organic liquid hydrogen storage system to supply hydrogen to the downstream, the organic liquid hydrogen storage system requires a certain response time from initiating an instruction to releasing hydrogen, resulting in an unstable amount of hydrogen supplied and an inability to ensure the smooth operation of downstream chemical equipment. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the uneven temporal distribution of energy and the unstable hydrogen supply caused by upstream wind and solar fluctuations, thereby providing a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] The method for stable hydrogen supply and comprehensive utilization of regional energy peak shifting includes the following steps:

[0008] Under high-load conditions, the heat storage system converts green electricity or abandoned electricity into thermal energy and stores it; the circulating water system converts the circulating water into steam after extracting heat from the steam drum, and the hydrogen production system uses the green electricity or abandoned electricity to produce hydrogen. The produced hydrogen is supplied to the waste heat utilization system together with the steam; the remaining hydrogen after the waste heat utilization system consumes it is transmitted to the organic liquid hydrogen storage system and the spherical tank hydrogen storage system for storage;

[0009] Under low-load conditions, the circulating water system converts the circulating water into steam after heat exchange with the heat storage system through the steam drum, and simultaneously releases hydrogen through the hydrogen release system and the spherical tank hydrogen storage system. The released hydrogen is supplied to the waste heat utilization system together with the steam; wherein, the hydrogen release system uses the thermal energy of the circulating water and steam after heat exchange with the heat storage system to release the hydrogen stored in the organic liquid hydrogen storage system; the spherical tank hydrogen storage system compensates for the startup time of the organic liquid hydrogen storage system when releasing hydrogen, and does not consume the thermal energy stored in the heat storage system, so as to maximize the supply of the heat storage system and reduce energy consumption during valley power periods.

[0010] Further optimizing the technical solution, the relationship between the heat storage capacity of the heat storage system and the external hydrogen supply of the organic liquid hydrogen storage system is as follows:

[0011] W1=V2×k×F

[0012] Where: W1 is the heat storage capacity of the heat storage system under high load conditions, and is the energy supplied by the organic liquid hydrogen storage system under low load conditions; V2 is the amount of hydrogen delivered by the organic liquid hydrogen storage system per unit time; F is the duration of hydrogen supply from the organic liquid hydrogen storage system; k is a coefficient;

[0013] The duration of hydrogen supply from the organic liquid hydrogen storage system is determined by the following formula:

[0014] F=(V3-V5) / V2+E1×V1 / V2

[0015] Among them: V3 is the amount of hydrogen stored in the organic liquid hydrogen storage system per unit time; V5 is the amount of hydrogen stored in the spherical tank hydrogen storage system per unit time; V1 is the amount of hydrogen produced by the hydrogen production system using green electricity or abandoned electricity per unit time.

[0016] Further optimizing the technical solution, under high load conditions, the prepared hydrogen is supplied to the waste heat utilization system together with the steam, including the following steps:

[0017] The prepared hydrogen is mixed with the steam and enters the refrigeration unit to produce chilled water, which is supplied to chilled water users through a chilled water pump;

[0018] After releasing latent heat, the steam flows to the condensate tank and is circulated to the steam drum through the condensate pump.

[0019] Further optimizing the technical solution, under low load conditions, the released hydrogen is supplied to the waste heat utilization system together with the steam, including the following steps:

[0020] The released hydrogen is mixed with the steam and directly enters the condensate tank to exchange heat with the heat exchanger in the condensate tank. The heated water in the insulation water pipe is supplied to the insulation water user.

[0021] The steam after heat exchange is condensed into condensed water, which is circulated to the steam drum through the condensate pump.

[0022] The hydrogen stable supply and regional energy peak-shifting comprehensive utilization system includes:

[0023] A heat storage system, which is used to convert green electricity or abandoned electricity into thermal energy for storage;

[0024] a steam drum, wherein the steam drum interacts thermally with the heat storage system;

[0025] A hydrogen production system, which is used to produce hydrogen using green electricity or abandoned electricity under high-load conditions;

[0026] A hydrogen storage system, which is used to store unabsorbed excess hydrogen under high-load conditions, and includes an organic liquid hydrogen storage system and a spherical tank hydrogen storage system;

[0027] A hydrogen release system, the organic liquid hydrogen storage system is connected to the hydrogen release system; under low load conditions, the hydrogen release system uses the heat energy of the circulating water and steam after heat exchange with the heat storage system to release the hydrogen stored in the organic liquid hydrogen storage system, and the organic liquid hydrogen storage system and the spherical tank hydrogen storage system release hydrogen simultaneously;

[0028] A circulating water system, wherein the circulating water system exchanges heat with the heat storage system through the steam drum and is supplied with heat by the heat storage system. The circulating water system is respectively connected to the organic liquid hydrogen storage system, the hydrogen release system, and the spherical tank hydrogen storage system. The circulating water system is connected to the waste heat utilization system. The circulating water system is used to form a closed water cycle for heat generation and recovery in the steam drum;

[0029] An energy control system is used to manage and control the heat storage system, hydrogen production system, hydrogen storage system and hydrogen release system according to upstream and downstream scheduling and hydrogen and heat supply needs.

[0030] To further optimize the technical solution, the steam drum and the heat storage system are connected by a heat transfer medium circulation pipeline, and the heat transfer medium circulation pipeline includes a heat extraction line and a heat return line connected thereto; the circulating water system is connected to the steam drum cavity and is not connected to the heat transfer medium circulation pipeline.

[0031] To further optimize the technical solution, the heat storage system is a solid-state heat storage system, which directly uses green electricity or abandoned electricity to store heat. The solid-state heat storage system is a container type or integrated in an insulation cavity. The temperature of the solid-state heat storage system is 700-1200°C, and the temperature difference is at least 450°C.

[0032] Further optimizing the technical solution, the solid-state heat storage system includes a heat exchange tube, and the heat exchange tube adopts a sleeve tube or a finned tube; and / or,

[0033] The solid-state heat storage system includes a fan, and the steam heat extraction of the solid-state heat storage system is controlled by the air volume output by the fan in the solid-state heat storage system.

[0034] To further optimize the technical solution, the circulating water system includes a circulating pipeline, a condensate tank and a condensate pump. The circulating pipeline is connected to the steam drum cavity, and the condensate tank and the condensate pump are respectively arranged on the circulating pipeline.

[0035] Further optimizing the technical solution, the waste heat utilization system includes a chilled water preparation module and a thermal insulation water external supply module;

[0036] The chilled water preparation module is arranged on the circulation pipeline between the condensate tank and the steam drum, and the chilled water preparation module includes a chilled water pipeline, a refrigeration unit, a chilled water pump and a chilled water user, and the refrigeration unit, the chilled water pump and the chilled water user are respectively arranged on the chilled water pipeline; and / or,

[0037] The insulated water external supply module includes an insulated water pipe, a heat exchanger, a hot water pump and an insulated water user. The heat exchanger is arranged inside the condensate tank, the water inlet end of the insulated water pipe is connected to the outlet of the heat exchanger, and the water outlet end of the insulated water pipe is connected to the inlet of the heat exchanger. The hot water pump and the insulated water user are respectively arranged on the insulated water pipe; a bypass is arranged between the insulated water pipes on both sides of the insulated water user, and a temperature-regulating bypass valve is arranged on the bypass.

[0038] The technical solution of the present invention has the following advantages:

[0039] 1. The present invention provides a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization. By adding a heat storage system, this system addresses the high curtailment rate caused by overloaded wind / photovoltaic power generation. Furthermore, by staggering the use of stored thermal energy to provide heat for the release of hydrogen from organic liquids during storage, this increases the utilization rate of green electricity and significantly reduces the high energy consumption and costs associated with low-load conditions. This reduces curtailment in green electricity hydrogen production or wind / solar power generation projects caused by exceeding the device's power consumption and the grid's permissible on-grid capacity, thereby increasing the overall economic efficiency of the project.

[0040] The spherical tank hydrogen storage system is coupled with the organic liquid hydrogen storage system. Under low-load conditions, the organic liquid hydrogen storage system and the spherical tank hydrogen storage system simultaneously release hydrogen. On the one hand, the spherical tank hydrogen storage system coupled with the organic liquid hydrogen storage system can compensate for the organic liquid hydrogen storage system's startup time. The combination of the two can eliminate upstream hydrogen fluctuations on time units ranging from seconds to days, ensuring a stable supply of downstream hydrogen. At the same time, the safety risks of large-scale hydrogen storage are reduced. On the other hand, the spherical tank hydrogen storage system coupled with the organic liquid hydrogen storage system can reduce the amount of reaction heat supply.

[0041] 2. The present invention provides a method and system for stable hydrogen supply and regional energy staggered utilization. This method couples electricity, hydrogen, and heat, using valley power or abandoned electricity from wind and solar power generation as input energy, which is stored in the form of hydrogen in an organic liquid hydrogen storage system and in the form of high-grade heat in a heat storage system. When upstream power levels are low, the high-grade heat is supplied to the hydrogen release system to supply hydrogen downstream. The low-grade heat produced by the hydrogen production system is stored and then smoothly output externally. By coupling a solid heat storage system with a steam drum to generate steam, staggered heat supply and hydrogen release are achieved, reducing operating costs and maintaining the minimum operating load of downstream equipment.

[0042] 3. The present invention provides a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization, which reduces regional heating and comprehensive operating energy consumption during low wind and solar power loads by efficiently and economically storing hydrogen and thermal energy and utilizing them during peak hours.

[0043] 4. The present invention provides a method and system for the stable supply of hydrogen and the comprehensive utilization of regional energy peak-shifting. Through evaporative refrigeration, the waste heat of low-grade steam from hydrogenation is utilized, and the externally supplied chilled water can be used as an external energy source for other devices, thereby achieving energy conservation and cost reduction.

[0044] 5. The present invention provides a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization, which reduces carbon emissions and lowers carbon trading costs through comprehensive energy utilization and storage, and improves the peak-shaving and valley-filling function in the region by rationally configuring the proportions and output times of each module.

[0045] 6. The present invention provides a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization. Through the energy control system, the regional energy storage module is supervised, and the energy Internet concept is applied to establish hydrogen energy and thermal energy cache areas through sub-modules to achieve regional energy balance and achieve efficient energy utilization.

[0046] 7. The present invention provides a method and system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization. By adding a lithium bromide refrigeration unit, it solves the problem of low-grade waste heat utilization under high-load conditions and the problem of insufficient system cooling capacity, thereby reducing system power consumption.

[0047] 8. The present invention provides a method and system for stable hydrogen supply and staggered regional energy utilization. By adding a condensate recovery system, heat generation and recovery in the steam drum form a closed-loop water cycle, reducing boiler makeup water consumption, alleviating downstream sewage loads, and lowering water consumption for the entire system. Furthermore, staggered heating reduces the heating load of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0049] Figure 1 This is a structural diagram of the hydrogen stable supply and regional energy peak-shifting comprehensive utilization system of the present invention;

[0050] Figure 2 This is a diagram of the energy utilization system of the present invention;

[0051] Figure 3 This is a diagram of the solid-state thermal storage steam generation system of the present invention;

[0052] Figure 4 It is an experimental effect diagram of the present invention.

[0053] Reference numerals:

[0054] 1. Heat storage system, 2. Steam drum, 21. Heat extraction line, 22. Heat return line, 3. Condensate pump, 4. Circulation pump, 5. Organic liquid hydrogen storage system, 6. Hydrogen release system, 7. Refrigeration unit, 8. Chilled water pump, 9. Condensate tank, 10. Chilled water user, 11. Hot water pump, 12. Insulated water user, 13. Temperature control bypass valve, 14. Spherical tank hydrogen storage system, 15. Energy control system, 16. Circulation pipeline, 17. Heat exchanger. DETAILED DESCRIPTION

[0055] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0058] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0059] It should be noted that, due to the volatility of wind and solar curves, the utilization of green electricity or abandoned electricity, part of the electricity generated by the green hydrogen project at peak times exceeds the load of the downstream hydrogen production device, and cannot be connected to the grid, which will be treated as abandoned electricity loss; in order to maintain the operation of the device during valley times, it is necessary to dispatch part of the grid electricity to be supplemented through the grid.

[0060] Cogeneration and thermal energy graded utilization technologies divide the system thermal energy into different grades and use them in a targeted manner through driving work, generating electricity with waste heat or step-by-step heat exchange to maximize energy utilization efficiency.

[0061] Hydrogen energy storage technology: organic liquid hydrogen storage releases 0.5-0.7MPaG grade steam to the outside. When releasing hydrogen, 2.4-2.7MPaG grade medium-pressure steam needs to be supplied from outside. 70% of the energy consumption in the entire storage and release process is externally supplied steam.

[0062] Heat storage technology converts electrical energy into thermal energy using solid materials or molten salts as media for heat storage; or uses high-quality heat sources to exchange heat and utilize the temperature difference of hot water to store sensible heat.

[0063] Absorption refrigeration technology utilizes the different characteristics of the saturated vapor pressure of certain special working fluid solutions and water, and uses thermal energy as the driving energy to achieve the purpose of refrigeration.

[0064] The specific embodiments of the present invention are described in detail below in conjunction with the hydrogen stable supply and regional energy peak-shifting comprehensive utilization system of the first aspect of the present invention.

[0065] It should be noted that the hydrogen stable supply and regional energy peak-shifting comprehensive utilization system of the first aspect of the present invention is only a preferred embodiment of the present invention. The hydrogen stable supply and regional energy peak-shifting comprehensive utilization system of the present invention can adopt the intermittent valve group of the first aspect of the present invention, and can also adopt other structures. For the convenience of explanation, the hydrogen stable supply and regional energy peak-shifting comprehensive utilization system of the first aspect of the present invention is explained in detail below.

[0066] like Figures 1 to 4As shown, this embodiment discloses a system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization based on the uncertainty of wind and solar fluctuations, including a heat storage system 1, a steam drum 2, a hydrogen production system, a hydrogen storage system, a hydrogen release system 6, a circulating water system and an energy control system 15.

[0067] The heat storage system 1 is used to convert green electricity or abandoned electricity into thermal energy for storage.

[0068] The steam drum 2 exchanges heat with the heat storage system 1 .

[0069] The hydrogen production system is used to produce hydrogen using green electricity or abandoned electricity under high-load conditions. The hydrogen production system includes but is not limited to electrolyzers.

[0070] The hydrogen storage system is used to store the remaining hydrogen that is not consumed under high load conditions. The hydrogen storage system includes an organic liquid hydrogen storage system 5 and a spherical tank hydrogen storage system 14.

[0071] The organic liquid hydrogen storage system 5 is connected to the hydrogen release system 6, and the two operate under different working conditions. The organic liquid hydrogen storage system 5 corresponds to the high-load working condition of the whole plant, and the hydrogen release system 6 corresponds to the low-load working condition of the whole plant. Among them, 70% of the energy consumption is the endothermic hydrogen release reaction. The hydrogen release unit supplies hydrogen to the downstream at low load to meet the stable operation of the downstream chemical equipment. The hydrogen release time is when green electricity is scarce and the downstream equipment is in the low-load operation stage. The by-product heat of the whole plant is small and it is in a period with higher electricity prices. Under low-load working conditions, the hydrogen release system 6 uses the thermal energy of the heat storage system 1 (the thermal energy of the circulating water and steam after heat exchange with the heat storage system) to release the hydrogen stored in the organic liquid hydrogen storage system 5, and the organic liquid hydrogen storage system 5 and the spherical tank hydrogen storage system 14 release hydrogen at the same time. It should be noted that the organic liquid hydrogen storage system 5 can be replaced by a solid-state hydrogen storage system. The organic liquid hydrogen storage system is organic hydrogen storage, and the solid-state hydrogen storage system is inorganic hydrogen storage.

[0072] The circulating water system exchanges heat with the heat storage system through steam drum 2, and the heat storage system provides heat supply. The circulating water system is connected to the organic liquid hydrogen storage system 5, the hydrogen release system 6, and the spherical tank hydrogen storage system 14, and is also connected to the waste heat utilization system. The circulating water system is used to form a closed water loop for heat generation and recovery in steam drum 2.

[0073] Energy control system 15 manages and controls the thermal storage system 1, hydrogen production system, hydrogen storage system, and hydrogen release system 6, as well as their output, based on upstream and downstream scheduling and hydrogen and heat supply needs. Energy control system 15 oversees regional energy storage modules and, utilizing the principles of the Energy Internet, establishes hydrogen and thermal energy cache zones through submodules, achieving regional energy balance and efficient energy utilization.

[0074] The above-mentioned hydrogen stable supply and regional energy peak-shifting comprehensive utilization system solves the problem of excessively high power abandonment rate caused by overload of wind power generation / photovoltaic power generation by adding a heat storage system 1. At the same time, by storing and using thermal energy in a peak-shifting manner, it provides heat for the storage and release of hydrogen in organic liquids, thereby increasing the utilization rate of green electricity and greatly reducing the problems of high energy consumption and high costs during low loads.

[0075] This embodiment couples three energy forms: electricity, hydrogen, and heat. Valley electricity or abandoned electricity in wind and solar power generation is used as input energy, which is stored in the organic liquid hydrogen storage system 5 in the form of hydrogen and in the heat storage system 1 in the form of high-level heat. When the upstream power supply is low, the high-level heat is supplied to the hydrogen release system to supply hydrogen to the downstream. The low-level heat energy produced by the hydrogen production system is stored and then smoothly output to the outside.

[0076] By efficiently and economically storing hydrogen and thermal energy and utilizing them in off-peak conditions, regional heating and comprehensive operating energy consumption can be reduced during low wind and solar power load periods.

[0077] Because the organic liquid hydrogen storage system 5 is suitable for long-term, large-scale storage of hydrogen, but a certain response time is required from initiating the command to releasing hydrogen. The spherical tank hydrogen storage system 14 can smooth the instantaneous fluctuations of upstream hydrogen, but large-scale application has safety risks. In this embodiment, the spherical tank hydrogen storage system 14 is coupled with the organic liquid hydrogen storage system 5. Under low-load conditions, the organic liquid hydrogen storage system 5 and the spherical tank hydrogen storage system 14 release hydrogen at the same time. On the one hand, after the spherical tank hydrogen storage system 14 is coupled with the organic liquid hydrogen storage system 5, it can compensate for the startup time of the organic liquid hydrogen storage system 5. The combination of the two can eliminate upstream hydrogen fluctuations in time units of seconds to days, ensure a stable supply of downstream hydrogen, and at the same time, the safety risk of large-scale storage of hydrogen is relatively small. On the other hand, under low-load conditions, the spherical tank hydrogen storage system 14 does not need to consume heat when supplying hydrogen. When the spherical tank hydrogen storage system 14 and the organic liquid hydrogen storage system 5 are used to supply hydrogen, the amount of hydrogen required by the organic liquid hydrogen storage system 5 is reduced, thereby reducing the energy consumption of the organic liquid hydrogen storage system 5, maximizing the supply of heat storage W1, and reducing energy consumption during off-peak hours.

[0078] In some embodiments, the steam drum 2 is connected to the heat storage system 1 through a heat transfer medium circulation pipeline, and the heat transfer medium circulation pipeline includes a heat extraction line 21 and a heat return line 22 that are connected to each other. The circulating water system is connected to the cavity of the steam drum 2 and is not connected to the heat transfer medium circulation pipeline. In this embodiment, the heat transfer medium in the heat transfer medium circulation pipeline can be thermal oil, and the steam drum 2 is a high-level tank for thermal oil. The heat extraction line 21 is a high-level waste heat boiler heat extraction system. The heat storage system 1 can store and release heat at the same time. The steam drum is connected to the heat storage system 1 through a heat extraction line and a heat return line, and adopts self-circulation heat extraction. The heat extraction line is saturated hot water. After heat exchange with high-temperature air in the heat storage system 1, the heat return line is saturated steam, which is transmitted to the steam drum in the form of latent heat to heat the water in the steam drum.

[0079] Currently, chemical plants generally do not have energy storage modules for thermal energy. Instead, they use waste heat for power generation or use energy in a cascaded manner. These thermal energy systems are poorly adaptable to fluctuating load conditions. Applying these thermal energy systems to green power or abandoned power hydrogen production projects not only results in waste but also creates significant fluctuations in the pipeline network, leading to complex operating conditions and difficulty adjusting thermal energy balance. To address this technical issue, this embodiment changes the "use it now" model in chemical projects, using organic liquids as hydrogen storage media, solid heat storage or molten salts as high-temperature heat storage media, and low-grade heat sources as the basis for preparing chilled water, thus achieving staggered energy utilization and waste heat recovery.

[0080] At present, the heat source of the solid heat storage system is the photothermal system. The defect is that the photothermal heat transfer medium is molten salt (that is, the medium required for the heat transfer of the photothermal system to the solid unit). The maximum temperature of the molten salt is 600°C, so the temperature difference that can be utilized is small (the actual heat usage is calculated at 250°C, and the temperature difference is at most 350°C), and the actual heat storage efficiency is low. In order to solve this technical problem, in some embodiments, the heat storage system is a solid-state heat storage system, which can be a molten salt heat storage system (using the sensible heat of the molten salt in the molten salt storage tank for heat storage). The solid-state heat storage system directly uses green electricity or abandoned electricity for heat storage. The solid-state heat storage system is container-type or integrated in the insulation cavity. When the whole plant has sufficient electricity, the electrical energy is converted into thermal energy and stored in the heat storage system. When in use, the heat is transported out through the air-water heat exchanger in the solid-state heat extraction fan heat supply module. The temperature of the solid-state heat storage system is 700-1200°C, the temperature difference is at least 450°C, and the intermediate links are reduced, and the intermediate heat loss is small.

[0081] In some embodiments, the solid-state heat storage system includes heat exchange tubes, which are either tube-in-tube or finned tubes. In finned tubes, saturated hot water enters the heat exchanger from the bottom and steam exits from the top. In a tube-in-tube heat exchanger, saturated hot water enters the heat exchanger from the inner tube and steam exits from the outer tube.

[0082] In some embodiments, the solid-state heat storage system includes a fan. The steam heat extraction capacity of the solid-state heat storage system is controlled by the air volume output by the fan in the solid-state heat storage system. The air volume can be controlled by adjusting the speed and number of fans in the solid-state heat storage system. The temperature of the heat extraction system is regulated by controlling the pressure in the steam drum 2.

[0083] In some embodiments, the solid-state heat storage system can store and release heat simultaneously. The stored heat W1 can be released across days (>24h) and can be used for heating and heat storage during valley electricity hours, that is, a valley electricity peak-shaving scheduling system is added.

[0084] In some embodiments, the circulating water system includes a circulation line 16, a condensate tank 9, and a condensate pump 3. The circulation line 16 communicates with the steam drum 2 cavity, and the condensate tank 9 and condensate pump 3 are respectively mounted on the circulation line 16. By adding a condensate recovery system, this embodiment forms a closed-loop water cycle for heat generation and recovery in the steam drum, reducing boiler makeup water consumption, alleviating downstream sewage loads, and lowering water consumption for the entire system. Furthermore, staggered heating reduces the heating load of the entire system.

[0085] Solid-state hydrogen storage and water electrolysis hydrogen production devices require chilled water as a refrigerant. Conventional chilled water production consumes electricity and is therefore uneconomical. To address this technical issue, this embodiment utilizes the heat stored in a solid-state heat storage system to heat the water in the circulating water system into steam, eliminating the need for additional electricity. Through evaporative cooling, the waste heat from the low-grade hydrogenated steam is utilized, while the supplied chilled water can be used as an external energy source for other devices, achieving energy savings and cost reductions.

[0086] In some embodiments, the waste heat utilization system includes a chilled water preparation module and a warm water external supply module.

[0087] The chilled water preparation module is arranged on the circulation pipeline 16 between the condensate tank 9 and the steam drum 2. The chilled water preparation module includes a chilled water pipeline, a refrigeration unit 7, a chilled water pump 8 and a chilled water user 10. The refrigeration unit 7, the chilled water pump 8 and the chilled water user 10 are respectively arranged on the chilled water pipeline.

[0088] Among them, refrigeration unit 7 is a lithium bromide refrigeration unit or an ammonia absorption refrigeration unit, which solves the problem of low-grade waste heat utilization under high-load conditions and the problem of insufficient system cooling capacity, and reduces system power consumption.

[0089] In some embodiments, the insulated water external supply module includes an insulated water pipeline, a heat exchanger 17, a hot water pump 11, and an insulated water user 12. The heat exchanger 17 is disposed within the condensate tank 9. The insulated water pipeline's water inlet is connected to the outlet of the heat exchanger 17, and the insulated water pipeline's water outlet is connected to the inlet of the heat exchanger 17. The hot water pump 11 and the insulated water user 12 are respectively disposed on the insulated water pipeline. A bypass is provided between the insulated water pipelines on both sides of the insulated water user 12, and a thermostatic bypass valve 13 is provided on the bypass. In this embodiment, when the heat exchanger 17 needs to exchange heat with the insulated water user 12, the thermostatic bypass valve 13 can be opened; when the heat exchanger 17 does not need to exchange heat with the insulated water user 12, the thermostatic bypass valve 13 can be closed, thereby preventing the insulated water user 12 from exchanging heat with the heat exchanger 17.

[0090] The operating temperature of the condensate heat storage tank is 100-170℃. It has a built-in heat exchanger, which heats the hot water. The hot water is then supplied to the outside through a hot water pump. The temperature of the external heating water is 90℃, and the heating water temperature is controlled by a thermostatic bypass valve.

[0091] When the steam drum 2 does not generate heat under low load conditions, heat is supplied to the outside through the sensible heat of the saturated water in the condensate tank 9.

[0092] Under high-load conditions, low-grade steam released by hydrogenation is sent through a steam line to the lithium bromide refrigeration unit, which produces 7°C chilled water through absorption refrigeration, with a recovery temperature of 12°C. After releasing latent heat, the steam flows by gravity to the condensate tank.

[0093] High-load chilled water users include water electrolysis hydrogen production units, solid-state hydrogen storage units, ammonia synthesis units, and methanol synthesis units.

[0094] The specific embodiments of the present invention are described in detail below in conjunction with the method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization according to the second aspect of the present invention.

[0095] It should be noted that the method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization of the second aspect of the present invention is only a preferred embodiment of the present invention. The method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization of the present invention can adopt the method of the second aspect of the present invention or other methods. For the convenience of explanation, the method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization of the second aspect of the present invention is explained in detail below.

[0096] This embodiment discloses a method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization based on the uncertainty of wind and solar power fluctuations, including the following steps:

[0097] During high-load conditions, when photovoltaic / wind power generation is high and electricity prices are low, some power is wasted. At this time, the heating module in the thermal storage system is activated, providing solid-state heat storage, which is stored as sensible heat by heating the thermal bricks. The circulating water system extracts heat from drum 2 and converts it into steam. Simultaneously, the hydrogen production system uses green electricity or wasted electricity to produce hydrogen, which is then supplied along with the steam to the waste heat utilization system. The remaining hydrogen after the waste heat utilization system consumes it is transferred to the organic liquid hydrogen storage system 5 and the spherical tank hydrogen storage system 14 for storage.

[0098] During high-load conditions, the hydrogen production system is simultaneously activated, extracting heat from the steam drum. The waste heat generated by the drum feeds the lithium bromide refrigeration unit, producing chilled water. At this time, the water electrolysis unit, solid-state hydrogen storage unit, and ammonia synthesis unit are all operating at full load, roughly equivalent to that of organic liquid hydrogen storage. Chilled water is then delivered to users in need. After releasing its latent heat, the steam flows by gravity into the condensate tank, where it is circulated through the condensate pump back to the steam drum to continue generating heat.

[0099] Under low-load conditions, the heating of the heat storage system stops, the organic liquid hydrogen storage system 5 shuts down, and the hydrogen release system 6 starts. The steam drum takes heat from the solid-state heat storage system through the heat extraction line, and the heat extraction is adjusted by the blower module in the solid-state heat storage, and the hydrogen supply is adjusted by the heat extraction. After the circulating water system exchanges heat with the heat storage system through the steam drum 2, the circulating water is converted into steam, and the hot water enters the hydrogen release system 6 through the circulating pump 4 for heating. The hydrogen release system 6 produces hydrogen to supply hydrogen to the downstream, and at the same time, the spherical tank hydrogen storage system 14 produces hydrogen to supply hydrogen to the downstream. Among them, the hydrogen release system 6 uses the thermal energy stored in the thermal storage system to release the hydrogen stored in the organic liquid hydrogen storage system 5; the spherical tank hydrogen storage system 14 compensates for the start-up time of the organic liquid hydrogen storage system 5 when releasing hydrogen, and does not consume the thermal energy stored in the thermal storage system, so as to maximize the supply of the thermal storage system and reduce energy consumption during valley power periods.

[0100] It should be noted that the high-load operating condition in this embodiment is a stage in which the upstream wind and photovoltaic power generation is high, the electricity and thermal energy of the entire plant is sufficient, and the cooling capacity is insufficient; the low-load operating condition is a stage in which the upstream wind and photovoltaic power generation is low, and the hydrogen energy and thermal energy of the entire plant are insufficient.

[0101] This method of stable hydrogen supply and regional energy staggered utilization leverages the uneven temporal distribution of green electricity within the region due to fluctuations in wind and solar power. By coupling electricity, hydrogen, and heat within the system and establishing heat exchange, storage, and transmission modules at different temperatures, regional energy storage and tiered utilization are achieved, allowing for a stable hydrogen supply from fluctuating green electricity to downstream hydrogen users.

[0102] This embodiment initially inputs intermittent upstream green electricity or abandoned electricity, and outputs a steady flow of hydrogen. This fully utilizes low-cost green electricity or abandoned electricity, converting it into hydrogen and heat when it's available. The hydrogen production is V1, the heat storage is W1 (in MJ), the hydrogen is exported at V2, and chemical hydrogen is stored at V3. When green electricity or abandoned electricity is insufficient, the stored heat W1 is converted into hydrogen, and the hydrogen exported is V4, where V2 = V4. The hydrogen storage capacity in the spherical tank is V5.

[0103] The relationship between the heat storage capacity of the heat storage system and the hydrogen supplied by the organic liquid hydrogen storage system 5 is:

[0104] W1=V2×k×F

[0105] Where: W1 is the heat storage capacity of the heat storage system under high load conditions and the energy supplied by the organic liquid hydrogen storage system under low load conditions; V2 is the amount of hydrogen delivered by the organic liquid hydrogen storage system per unit time; F is the duration of hydrogen delivery by the organic liquid hydrogen storage system; the longer the hydrogen delivery duration, the greater W1; k is the safety factor. The K value selected in the present invention is 2.7, and the F value is 9. It can be seen that the hydrogen supply curve is basically stable. The amount of hydrogen delivered during the dehydrogenation process is basically stable.

[0106] Take the 8760-hour wind and solar curve of a certain project as an example (combined with Figure 4 a) Generate a hydrogen production curve with strong fluctuations based on the wind and solar power generation curve (combined with Figure 4 b) By rationally adjusting the hydrogen ball tank storage capacity and hydrogen release rate (combined with Figure 4 c), further configure the organic liquid hydrogen storage capacity and hydrogen storage rate V2 ( Figure 4 ), and finally form a stable external hydrogen supply curve (combined with Figure 4 d).

[0107] The duration of hydrogen supply from the organic liquid hydrogen storage system is determined by the following formula:

[0108] F=V3-V5 / V2+E1×V1 / V2

[0109] It can be seen from this that the duration of external hydrogen supply of the organic liquid hydrogen storage system is determined by the following two aspects: first, it is determined by (V3-V5) / V2, that is, the duration obtained by total storage / external supply; second, it is determined by the compensation duration (E1×V1 / V2), which is suitable for ensuring the stable release of hydrogen at the downstream minimum load when there is no external hydrogen supply source for a long time (corresponding to the situation of long-term no wind and no light).

[0110] Among them: V3 is the amount of hydrogen stored in the organic liquid hydrogen storage system per unit time; V5 is the amount of hydrogen stored in the spherical tank hydrogen storage system per unit time; V1 is the amount of hydrogen produced by the hydrogen production system using abandoned electricity per unit time; E1 is related to photovoltaic and wind power. The value of E1 is determined according to the variable range and frequency of V1 and V2. Different V1 / V2 values ​​will result in different E1 values. The photovoltaic value is 4 to 10, and the wind power value is 8 to 15. Photovoltaic V5 / V3 = 0.2 to 1, wind power V5 / V3 = 0.5 to 1.25. Among them, the units of V1, V2, V3, V4, and V5 are all Nm 3 / h.

[0111] If, under low-load conditions, only the organic liquid hydrogen storage system 5 and the hydrogen release system 6 are set up to supply hydrogen, the hydrogen release system 6 needs to consume the thermal energy of the heat storage system. If the amount of hydrogen used by the downstream hydrogen-using device increases, the hydrogen release system 6 is needed to prepare more hydrogen, and the heat storage system needs to be multiplied to meet the consumption of thermal energy. In order to solve this technical problem, the above-mentioned method of stable hydrogen supply and regional energy peak-shifting comprehensive utilization adds a spherical tank hydrogen storage system, so that part of the hydrogen is not supplied through the organic liquid hydrogen storage system 5, but is directly supplied using the spherical tank hydrogen storage system, reducing the energy consumption of the organic liquid hydrogen storage system 5, maximizing the supply of heat storage W1, and reducing energy consumption during valley electricity hours. The amount of W1 energy reduced by the spherical tank hydrogen storage system is △W1=V5×2.366.

[0112] Under high load conditions, the prepared hydrogen is supplied together with steam to the waste heat utilization system, which includes the following steps:

[0113] When the hydrogen produced by water electrolysis in the plant cannot be fully consumed by downstream equipment, it is stored in an organic liquid via a hydrogen storage system, simultaneously producing steam at a temperature of 140-180°C. The produced hydrogen and steam are mixed and then fed into a refrigeration unit 7 to produce chilled water, which is then supplied to chilled water users 10 via a chilled water pump 8.

[0114] After releasing latent heat, the steam flows to the condensate tank 9 by gravity, and the condensate is circulated to the steam drum 2 through the condensate pump 3 for recycling.

[0115] Under low load conditions, the released hydrogen is supplied together with steam to the waste heat utilization system, which includes the following steps:

[0116] When the entire plant is operating at low load, the circulating water pump continuously supplies heat to the hydrogen release system, with the saturated hot water temperature ranging from 200 to 230°C. The hydrogen release system absorbs heat and releases hydrogen through a chemical reaction. The released hydrogen is mixed with steam and transported to the downstream hydrogen-using unit, which is a chemical plant that uses hydrogen as a raw material, such as an ammonia synthesis plant or a methanol synthesis plant. It then directly enters the condensate tank 9 and exchanges heat with the heat exchanger 17 therein. The heated water in the insulated water pipeline is supplied to the insulated water user 12. The insulated water external supply module continuously exchanges heat from the condensate tank through the plate, and adjusts the flow rate by bypassing to adjust the heating water temperature.

[0117] The steam after heat exchange is condensed into condensed water, which is circulated to the steam drum 2 through the condensate pump 3.

[0118] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization, characterized in that: The following steps are involved: Under high-load conditions, green electricity or abandoned electricity is converted into thermal energy and stored through the heat storage system; the circulating water is converted into steam after heat is taken out through the steam drum (2) by the circulating water system, and hydrogen is produced by the hydrogen production system using green electricity or abandoned electricity. The produced hydrogen is supplied to the waste heat utilization system together with the steam; the remaining hydrogen after the waste heat utilization system consumes it is transmitted to the organic liquid hydrogen storage system (5) and the spherical tank hydrogen storage system (14) for storage; Under low-load conditions, the circulating water system converts the circulating water into steam after heat exchange with the heat storage system through the steam drum (2), and simultaneously releases hydrogen through the hydrogen release system (6) and the spherical tank hydrogen storage system (14). The released hydrogen and the steam are supplied to the waste heat utilization system together; wherein, the hydrogen release system (6) uses the heat energy of the circulating water and steam after heat exchange with the heat storage system to release the hydrogen stored in the organic liquid hydrogen storage system (5); the spherical tank hydrogen storage system (14) compensates for the start-up time of the organic liquid hydrogen storage system (5) when releasing hydrogen, and does not consume the heat energy stored in the heat storage system, so as to maximize the supply of the heat storage system and reduce energy consumption during off-peak hours.

2. The method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization according to claim 1, characterized in that: The relationship between the heat storage capacity of the heat storage system and the external hydrogen supply of the organic liquid hydrogen storage system (5) is: W1=V2×k×F Where: W1 is the heat storage capacity of the heat storage system under high load conditions and the energy supplied by the organic liquid hydrogen storage system under low load conditions; V2 is the amount of hydrogen delivered by the organic liquid hydrogen storage system per unit time; F is the duration of hydrogen supply from the organic liquid hydrogen storage system; k is a coefficient, k = 2.7 to 3.0; The duration of hydrogen supply from the organic liquid hydrogen storage system is determined by the following formula: F=(V3-V5) / V2+E1×V1 / V2 Among them: V3 is the amount of hydrogen stored in the organic liquid hydrogen storage system per unit time; V5 is the amount of hydrogen stored in the spherical tank hydrogen storage system per unit time; V1 is the amount of hydrogen produced by the hydrogen production system using green electricity or abandoned electricity per unit time.

3. The method for stable hydrogen supply and regional energy peak-shifting comprehensive utilization according to claim 1, characterized in that: Under high load conditions, the prepared hydrogen is supplied together with the steam to the waste heat utilization system, which includes the following steps: The prepared hydrogen is mixed with the steam and enters the refrigeration unit (7) to generate chilled water, which is then supplied to the chilled water user (10) via a chilled water pump (8); After releasing the latent heat, the steam flows to the condensate tank (9) by gravity and is circulated to the steam drum (2) through the condensate pump (3).

4. The method for stable hydrogen supply and staggered utilization of regional energy according to claim 1, characterized in that: Under low load conditions, the released hydrogen is supplied together with the steam to a waste heat utilization system, which includes the following steps: The released hydrogen is mixed with the steam and directly enters the condensation tank (9) and exchanges heat with the heat exchanger (17) in the condensation tank (9). The heated water in the insulation water pipe is supplied to the insulation water user (12); The steam after heat exchange is condensed into condensed water, which is circulated to the steam drum (2) through the condensate pump (3).

5. A system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization, characterized by: include: A heat storage system (1), wherein the heat storage system (1) is used to convert green electricity or abandoned electricity into thermal energy for storage; a steam drum (2), wherein the steam drum (2) exchanges heat with the heat storage system (1); A hydrogen production system, which is used to produce hydrogen using green electricity or abandoned electricity under high-load conditions; A hydrogen storage system, the hydrogen storage system is used to store unabsorbed residual hydrogen under high-load conditions, the hydrogen storage system comprising an organic liquid hydrogen storage system (5) and a spherical tank hydrogen storage system (14); A hydrogen release system (6), wherein the organic liquid hydrogen storage system (5) is connected to the hydrogen release system (6); under low-load conditions, the hydrogen release system (6) utilizes the heat energy of circulating water and steam after heat exchange with the heat storage system to release the hydrogen stored in the organic liquid hydrogen storage system (5), and the organic liquid hydrogen storage system (5) and the spherical tank hydrogen storage system (14) release hydrogen simultaneously; A circulating water system, wherein the circulating water system exchanges heat with the heat storage system (1) through the steam drum (2) and the heat storage system (1) supplies heat, the circulating water system is respectively connected to the organic liquid hydrogen storage system (5), the hydrogen release system (6) and the spherical tank hydrogen storage system (14), the circulating water system is connected to the waste heat utilization system, and the circulating water system is used to form a closed-circuit water cycle for heat generation and recovery in the steam drum (2); An energy control system (15) is used to manage and control the heat storage system (1), the hydrogen production system, the hydrogen storage system and the hydrogen release system (6) according to upstream and downstream scheduling and hydrogen and heat supply requirements.

6. A hydrogen stable supply and regional energy peak-shifting comprehensive utilization system according to claim 5, characterized in that: The steam drum (2) and the heat storage system (1) are connected via a heat transfer medium circulation pipeline, wherein the heat transfer medium circulation pipeline comprises a heat extraction line (21) and a heat return line (22) that are connected to each other; the circulating water system is connected to the steam drum (2) cavity and is not connected to the heat transfer medium circulation pipeline.

7. A hydrogen stable supply and regional energy peak-shifting comprehensive utilization system according to claim 5, characterized in that: The heat storage system (1) is a solid-state heat storage system, which directly uses green electricity or abandoned electricity to store heat. The solid-state heat storage system is container-type or integrated in a heat preservation cavity. The temperature of the solid-state heat storage system is 700-1200°C, and the temperature difference is at least 450°C.

8. A hydrogen stable supply and regional energy peak-shifting comprehensive utilization system according to claim 7, characterized in that: The solid-state heat storage system includes a heat exchange tube, and the heat exchange tube is a sleeve tube or a fin tube; and / or, The solid-state heat storage system includes a fan, and the steam heat extraction of the solid-state heat storage system is controlled by the air volume output by the fan in the solid-state heat storage system.

9. The system for stable hydrogen supply and regional energy peak-shifting comprehensive utilization according to claim 5 is characterized in that: The circulating water system comprises a circulating pipeline (16), a condensate tank (9) and a condensate pump (3); the circulating pipeline (16) is in communication with the steam drum (2) cavity; the condensate tank (9) and the condensate pump (3) are respectively arranged on the circulating pipeline (16).

10. A hydrogen stable supply and regional energy peak-shifting comprehensive utilization system according to claim 9, characterized in that: The waste heat utilization system includes a chilled water preparation module and a thermal insulation water external supply module; The chilled water preparation module is arranged on a circulation pipeline (16) between a condensate tank (9) and a steam drum (2), and the chilled water preparation module comprises a chilled water pipeline, a refrigeration unit (7), a chilled water pump (8) and a chilled water user (10), and the refrigeration unit (7), the chilled water pump (8) and the chilled water user (10) are respectively arranged on the chilled water pipeline; and / or, The heat-insulated water external supply module comprises a heat-insulated water pipe, a heat exchanger (17), a hot water pump (11) and a heat-insulated water user (12); the heat exchanger (17) is arranged inside a condensation tank (9); the water inlet end of the heat-insulated water pipe is connected to the outlet of the heat exchanger (17); the water outlet end of the heat-insulated water pipe is connected to the inlet of the heat exchanger (17); the hot water pump (11) and the heat-insulated water user (12) are respectively arranged on the heat-insulated water pipe; a bypass is arranged between the heat-insulated water pipes on both sides of the heat-insulated water user (12); and a temperature-regulating bypass valve (13) is arranged on the bypass.

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