CN118273879A - Hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization - Google Patents
Hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization Download PDFInfo
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- 239000001257 hydrogen Substances 0.000 title claims abstract description 200
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 200
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 170
- 239000007788 liquid Substances 0.000 title claims abstract description 138
- 238000004146 energy storage Methods 0.000 title claims abstract description 54
- 230000008878 coupling Effects 0.000 title claims abstract description 18
- 238000010168 coupling process Methods 0.000 title claims abstract description 18
- 238000005859 coupling reaction Methods 0.000 title claims abstract description 18
- 238000010248 power generation Methods 0.000 claims abstract description 76
- 238000004519 manufacturing process Methods 0.000 claims abstract description 27
- 238000003860 storage Methods 0.000 claims description 101
- 239000012530 fluid Substances 0.000 claims description 82
- 238000001816 cooling Methods 0.000 claims description 42
- 150000002431 hydrogen Chemical class 0.000 claims description 30
- 238000005338 heat storage Methods 0.000 claims description 28
- 238000000926 separation method Methods 0.000 claims description 28
- 239000007789 gas Substances 0.000 claims description 25
- 239000003507 refrigerant Substances 0.000 claims description 17
- 238000004887 air purification Methods 0.000 claims description 12
- 238000009825 accumulation Methods 0.000 claims description 11
- 230000006835 compression Effects 0.000 claims description 4
- 238000007906 compression Methods 0.000 claims description 4
- 238000002309 gasification Methods 0.000 claims description 4
- 230000005611 electricity Effects 0.000 abstract description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 abstract description 4
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 239000003345 natural gas Substances 0.000 abstract description 2
- 239000003949 liquefied natural gas Substances 0.000 description 81
- 238000000034 method Methods 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 230000009467 reduction Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 2
- 239000003570 air Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Abstract
The application provides a hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization, which comprises the following components: an LNG supply unit; the wind-light generating unit generates power by utilizing wind energy and solar energy, and can output first electric energy in a first power generation state and output second electric energy exceeding the first electric energy in a second power generation state; the wind-solar power generation hydrogen production unit is used for producing hydrogen by utilizing the first electric energy; the hydrogen liquefying unit is used for liquefying the prepared hydrogen by utilizing the cold energy of the LNG in the LNG supply unit; and the liquid air energy storage unit exchanges heat with the LNG in the LNG supply unit to liquefy the air and store energy, and the liquefied air is pressurized, expanded to generate power and then combined with the second electric energy to enter a power grid. The application can produce green hydrogen products, green electricity which can stably access the internet and high-pressure natural gas which can be externally delivered, and only LNG cold energy and renewable wind-light energy which are reasonably utilized are consumed, thereby realizing the efficient utilization and conversion of energy.
Description
Technical Field
The application belongs to the technical field of cold energy utilization, cryogenic liquefaction and liquid air energy storage systems, and particularly relates to a hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization.
Background
Liquefied natural gas (Liquefied Natural Gas, LNG for short) is used as clean and high-quality fuel, a large amount of high-quality cold energy is stored, and the high-grade cold energy of about 830kJ/kg can be released when the LNG is gasified. The cold energy of high-pressure LNG gasification in LNG receiving station can not make full use of, leads to a large amount of high-quality cold energy to be taken away by mediums such as sea water, causes the waste of energy. The electric energy in the wind-solar power generation field can fluctuate along with objective reasons such as weather and cannot be directly used on the internet; although the wind-solar power generation field can be produced by coupling with an electrolytic hydrogen production device, the produced hydrogen still has the problems of incapability of high-efficiency storage and transportation and the like. Therefore, how to realize energy peak-valley matching and hydrogen liquefaction output is a problem to be solved at present.
Disclosure of Invention
Aiming at the technical problems in the prior art, the embodiment of the application provides a hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization.
The technical scheme adopted by the embodiment of the application is as follows: a hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization comprises:
An LNG supply unit;
The wind-light power generation unit generates power by utilizing wind energy and solar energy, and has a first power generation state and a second power generation state, wherein in the first power generation state, the wind-light power generation unit can output first electric energy, and in the second power generation state, the wind-light power generation unit can output the first electric energy and second electric energy exceeding the first electric energy;
the wind-light power generation hydrogen production unit is used for producing hydrogen by utilizing the first electric energy output by the wind-light power generation unit;
The hydrogen liquefying unit is used for liquefying the hydrogen produced by the wind-solar power generation hydrogen production unit by utilizing the cold energy of the LNG in the LNG supply unit;
And the liquid air energy storage unit exchanges heat with the LNG in the LNG supply unit to liquefy the air and store energy, and the liquefied air is pressurized and then expanded to generate power and is combined with the second electric energy output by the wind-solar power generation unit to enter a power grid.
In an optional embodiment, the liquid air energy storage unit includes an air purification supercharging device, a compressor stage rear heat exchanger, a multi-channel heat exchanger, an air expansion machine, a liquid-air separation tank, a liquid air storage tank, a high-pressure pump, a generator front heat exchanger and a generator, wherein the air sequentially passes through the air purification supercharging device, the compressor stage rear heat exchanger, the heat exchange and the cooling, then enters a first hot fluid channel of the multi-channel heat exchanger, exchanges heat with LNG flowing through a first cold fluid channel of the multi-channel heat exchanger, and then enters the liquid-air separation tank for gas-liquid separation after being cooled by the air expansion machine, and the separated liquid air enters the liquid air storage tank for storage; the high-pressure pump is connected with the liquid air storage tank and is used for pressurizing the liquid air in the liquid air storage tank and then sending the pressurized liquid air into the generator front heat exchanger for heat exchange and temperature rise, and the liquid air after temperature rise and gasification enters the generator for power generation.
In an alternative embodiment, the top parts of the liquid air storage tank and the liquid air separation tank are respectively connected with the inlets of the second cold fluid channels of the multi-channel heat exchanger, so that the low-temperature air separated by the liquid air separation tank and the evaporated gas evaporated in the liquid air storage tank are both used as liquid air return gas to enter the multi-channel heat exchanger to participate in heat exchange, the cold energy is released, the temperature is raised, and the air enters the inlet of the air purification supercharging device after the heat exchange and the temperature rise.
In an alternative embodiment, the liquid air energy storage unit further comprises a heat storage packed bed, and the heat storage packed bed is connected with the heat storage loop and the heat release loop;
The cold fluid channel of the post-compressor heat exchanger is connected in series with the heat storage loop of the heat storage packed bed, so that circulating hot oil in the heat storage loop of the heat storage packed bed exchanges heat with air flowing through the hot fluid channel of the post-compressor heat exchanger in the post-compressor heat exchanger, absorbs air compression heat, and stores the absorbed heat energy in the heat storage packed bed;
the heat fluid channel of the generator front heat exchanger is connected in series with the heat release loop of the heat storage packed bed, so that circulating hot oil in the heat release loop of the heat storage packed bed exchanges heat with liquid air flowing through the cold fluid channel of the generator front heat exchanger in the generator front heat exchanger, and heat energy stored in the heat storage packed bed is released to the liquid air.
In an alternative embodiment, the liquid air energy storage unit further comprises a cold storage packed bed, and the cold storage packed bed is connected with the cold storage loop and the cold release loop;
the second hot fluid channel of the multi-channel heat exchanger is connected in series on the cold storage loop of the cold storage packed bed, so that circulating refrigerant in the cold storage loop of the cold storage packed bed exchanges heat with LNG flowing through the first cold fluid channel of the multi-channel heat exchanger in the multi-channel heat exchanger, cold energy of the LNG is absorbed, and the absorbed cold energy of the LNG is stored in the cold storage packed bed;
The cold release loop of the cold accumulation packed bed is connected with the hydrogen liquefying unit and is used for providing cold energy stored by the cold accumulation packed bed for the hydrogen liquefying unit and liquefying hydrogen.
In an alternative embodiment, the hydrogen liquefying unit comprises a pre-cooling cold box, and an inlet of a hot fluid channel of the pre-cooling cold box is connected with the wind-light power generation hydrogen producing unit so that the hydrogen produced by the wind-light power generation hydrogen producing unit enters the hot fluid channel of the pre-cooling cold box; the first cold fluid channel of the pre-cooling cold box is connected with the first cold fluid channel of the multi-channel heat exchanger, so that LNG subjected to heat exchange in the multi-channel heat exchanger enters the pre-cooling cold box to exchange heat with hydrogen, and the hydrogen is cooled.
In an alternative embodiment, the hydrogen liquefying unit further comprises a cryogenic box, and a hot fluid channel of the cryogenic box is connected with a hot fluid channel of the pre-cooling box, so that the hydrogen after heat exchange of the pre-cooling box enters the hot fluid channel of the cryogenic box;
The second hot fluid channel of the multi-channel heat exchanger is connected in series on a cold storage loop of the cold storage packed bed, so that circulating refrigerant in the cold storage loop of the cold storage packed bed exchanges heat with LNG flowing through the first cold fluid channel of the multi-channel heat exchanger in the multi-channel heat exchanger, cold energy of the LNG is absorbed, and the absorbed cold energy of the LNG is stored in the cold storage packed bed; the first cold fluid channel of the cryogenic box is connected in series with the cold releasing loop of the cold storage packed bed, so that the circulating refrigerant in the cold releasing loop of the cold storage packed bed exchanges heat with the hydrogen flowing through the hot fluid channel of the cryogenic box in the cold fluid channel of the cryogenic box, and cold energy stored in the cold storage packed bed is released to the hydrogen, and the hydrogen is cooled.
In an alternative embodiment, the hydrogen liquefying unit further includes a hydrogen expander, a hydrogen separation tank and a liquid hydrogen storage tank, an inlet of the hydrogen expander is connected with an outlet of the hot fluid channel of the cryogenic tank, an outlet of the hydrogen expander is connected with an inlet of the hydrogen separation tank, and an outlet of the hydrogen separation tank is connected with the liquid hydrogen storage tank, so that hydrogen cooled by the cryogenic tank is depressurized and cooled by the hydrogen expander and stored in the liquid hydrogen storage tank.
In an alternative embodiment, the tops of the liquid hydrogen storage tank and the hydrogen separation tank are respectively connected to the inlet of the second cold fluid channel of the cryogenic tank, the outlet of the second cold fluid channel of the cryogenic tank is connected to the inlet of the second cold fluid channel of the pre-cooling tank, and the outlet of the second cold fluid channel of the pre-cooling tank is connected to the wind-solar power generation hydrogen production unit.
Compared with the prior art, the embodiment of the application has the beneficial effects that: the application solves the problem that energy and energy cannot be efficiently utilized by coupling co-production of five large-scale energy systems, namely the wind-solar power generation unit, the wind-solar power generation hydrogen production unit, the hydrogen liquefaction unit, the LNG receiving station (LNG providing unit) and the liquid air energy storage unit, and provides an engineering feasibility scheme for coupling co-production of the large-scale energy systems.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application, as claimed.
An overview of various implementations or examples of the technology described in this disclosure is not a comprehensive disclosure of the full scope or all of the features of the technology disclosed.
Drawings
In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. The accompanying drawings illustrate various embodiments by way of example in general and not by way of limitation, and together with the description and claims serve to explain the disclosed embodiments. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Such embodiments are illustrative and not intended to be exhaustive or exclusive of the present apparatus or method.
Fig. 1 is a schematic diagram of a hydrogen liquefaction coupling liquid air energy storage integrated energy system based on LNG cold energy utilization according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. It will be apparent that the described embodiments are some, but not all, embodiments of the application. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present application fall within the protection scope of the present application.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.
In order to keep the following description of the embodiments of the present application clear and concise, the detailed description of known functions and known components thereof have been omitted.
The method aims at solving the problems that a large amount of high-quality cold energy resources are wasted due to the fact that high-pressure LNG is gasified and then is output in the existing LNG receiving station, and the energy is unstable and hydrogen cannot be directly conveyed and utilized in the large-scale wind-light power generation and wind-light hydrogen production industries. The application adopts the measures of large-scale cryogenic energy type energy storage device, LNG cold energy stepped utilization and the like to realize energy peak-valley matching and hydrogen liquefaction output.
As shown in fig. 1, the embodiment of the application provides a hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization, which comprises an LNG supply unit, a wind-solar power generation unit 1, a wind-solar power generation hydrogen production unit 2, a hydrogen liquefaction unit 3 and a liquid air energy storage unit 9.
The LNG supply unit is used for providing cold energy released by LNG during gasification export for the hydrogen liquefaction unit 3 and the liquid air energy storage unit 9, respectively.
The wind-solar power generation unit 1 generates power using wind energy and solar energy to be able to output electric energy. The wind-light power generation unit 1 has a first power generation state in which the wind-light power generation unit 1 can output first electric power, and a second power generation state in which the wind-light power generation unit 1 can output first electric power and second electric power exceeding the first electric power.
The wind-light power generation hydrogen production unit 2 utilizes the first electric energy output by the wind-light power generation unit 1 to produce hydrogen.
The hydrogen liquefying unit 3 uses the cold energy of the LNG in the LNG supply unit to liquefy the hydrogen produced by the wind-solar power generation hydrogen production unit 2 so as to realize the liquefaction of the hydrogen and facilitate transportation.
The liquid air energy storage unit 9 exchanges heat with LNG in the LNG supply unit to liquefy air and store energy, and the liquefied air is pressurized, expanded to generate power and then combined with second electric energy output by the wind-solar power generation unit 1 to enter a power grid.
The specific structural form of the wind-solar power generation unit 1 is not limited, and the wind-solar power generation unit 1 commonly used in the prior art can be adopted.
Because the wind-light power generation unit 1 is influenced by the intensity of wind power and sunlight, the electric energy output by the wind-light power generation unit 1 has certain fluctuation, so that the electric energy output by the wind-light power generation unit 1 is fluctuation instead of being stable and unchanged all the time, but the electric energy is the first electric energy no matter what the electric energy output by the wind-light power generation unit 1 is always not lower than a certain amount. When the wind power and the sunlight conditions are poor, the wind-light generating unit 1 is in a first power generation state, and the wind-light generating unit 1 can only output first electric energy; when the wind power and the sunlight are abundant, the wind-light power generation unit 1 is in the second power generation state, the wind-light power generation unit 1 can output more electric energy, the output electric energy is more than the first electric energy, and the electric energy exceeding the first electric energy is the second electric energy. The first electrical energy may be defined as a steady electrical energy and the second electrical energy as a fluctuating electrical energy. The first electric energy which is stable and unchanged is used for preparing hydrogen, so that continuous and smooth preparation of hydrogen is ensured. The fluctuating second electric energy and the electric energy generated by the liquid air energy storage unit 9 are combined into a power grid, so that stable surfing of wind-solar power generation is realized.
It will be appreciated that it is necessary to determine the first electrical energy in a stable and constant range by predicting the capacity and fluctuation range of the entire wind-solar power generation unit 1 and select the first electrical energy to enter the wind-solar power generation hydrogen production unit 2. For example, for instance, the wind-solar power generation unit 1 has an electric energy output of at least 10MW no matter how the environment changes, then the part of electric energy is the first electric energy which is stable and unchanged, the part of electric energy is used for hydrogen production, the other part of electric energy which fluctuates is the second electric energy, and the second electric energy enters the liquid air energy storage unit 9 according to the fluctuation period of the second electric energy to store energy and peak shaving so as to realize green power surfing.
According to the embodiment of the application, the wind-solar power generation, wind-solar hydrogen production, LNG receiving station and liquid air energy storage device are coupled and co-produced, so that green electricity surfing and green liquid hydrogen transportation can be realized, the utilization efficiency of LNG cold energy is improved, and further, the available energy and the high-efficiency utilization of energy are realized.
In some embodiments, continuing with fig. 1, the liquid air storage unit 9 includes an air purification booster device 10, a compressor stage post heat exchanger 11, a multi-channel heat exchanger 12, an air expander 13, a liquid air separator tank 14, a liquid air storage tank 15, a high pressure pump 16, a generator 18 pre heat exchanger 17, and a generator 18. Firstly, air enters the liquid air energy storage unit 9 through the air purification supercharging device 10, is purified and supercharged through the air purification supercharging device 10, enters the compressor stage and then enters the heat exchanger 11 for heat exchange and cooling, and low-temperature high-pressure air is formed. The high-pressure air enters the first hot fluid channel 121 of the multi-channel heat exchanger 12, exchanges heat with LNG flowing through the first cold fluid channel 123 of the multi-channel heat exchanger 12, cools down, the cooled air enters the air expander 13 to continue cooling down, then enters the liquid-air separation tank 14 for gas-liquid separation, and the separated liquid air enters the liquid air storage tank 15 for storage. The high-pressure pump 16 is connected with the liquid air storage tank 15 and is used for pressurizing the liquid air in the liquid air storage tank 15 and then sending the pressurized liquid air into the heat exchanger 17 before the generator 18 to heat exchange and raise the temperature, and the heated and gasified liquid air enters the generator 18 to generate power so as to peak-shaving unstable green electricity and realize stable surfing of wind-solar power generation.
In some embodiments, as shown in fig. 1, the low-temperature air separated by the liquid-air separation tank 14 and the evaporated gas evaporated in the liquid-air storage tank 15 both enter the second cold fluid channel 124 of the multi-channel heat exchanger 12 as liquid-air return gas, participate in heat exchange of the multi-channel heat exchanger 12, provide cooling capacity for air liquefaction, and meanwhile, the liquid-air return gas is warmed up and enters the inlet of the air purification supercharging device 10 after heat exchange and warming up to participate in the next air liquefaction process. Therefore, the utilization rate of the air is improved, cold energy contained in the liquid-air return air is effectively utilized, and the utilization rate of the cold energy is improved.
In some embodiments, the liquid air energy storage unit 9 further comprises a packed bed of thermal storage 19, the packed bed of thermal storage 19 connecting a thermal storage circuit 191 and a heat release circuit 192.
As shown in fig. 1, the cold fluid channel of the post-compressor heat exchanger is connected in series to the heat storage circuit 191 of the heat storage packed bed 19, so that the circulating hot oil in the heat storage circuit 191 of the heat storage packed bed 19 exchanges heat with the air flowing through the hot fluid channel of the post-compressor heat exchanger in the post-compressor heat exchanger, absorbs the air compression heat, and stores the absorbed heat energy in the heat storage packed bed 19. The hot fluid passage of the generator 18 front heat exchanger 17 is connected in series with the heat release circuit 192 of the packed bed 19, so that the circulating hot oil in the heat release circuit 192 of the packed bed 19 exchanges heat with the liquid air flowing through the cold fluid passage of the generator 18 front heat exchanger 17 in the generator 18 front heat exchanger 17 to release the heat energy stored in the packed bed 19 to the liquid air. That is, the heat generated by the air in the air purifying and pressurizing device 10 is absorbed by the circulating hot oil and stored in the heat storage packed bed 19, and the heat stored in the heat storage packed bed 19 is carried by the circulating hot oil again, and exchanges heat with the liquid air in the heat exchanger 17 before the generator 18, so as to raise the temperature of the liquid air before entering the generator 18.
In some embodiments, the liquid air energy storage unit 9 further comprises a cold storage packed bed 20, the cold storage packed bed 20 connecting the cold storage circuit 201 and the cold release circuit 202.
As shown in fig. 1, the second hot fluid channel 122 of the multi-channel heat exchanger 12 is connected in series to the cold storage circuit 201 of the cold storage packed bed 20, so that the circulating refrigerant in the cold storage circuit 201 of the cold storage packed bed 20 exchanges heat with the LNG flowing through the first cold fluid channel 123 of the multi-channel heat exchanger 12 in the multi-channel heat exchanger 12, absorbs the cold energy of the LNG, and stores the absorbed cold energy of the LNG in the cold storage packed bed 20. The cold release circuit 202 of the cold storage packed bed 20 is connected to the hydrogen liquefying unit 3, and is used for providing cold energy stored in the cold storage packed bed 20 to the hydrogen liquefying unit 3 for liquefying hydrogen.
The high-pressure air enters the multi-channel heat exchanger 12 to exchange heat with LNG and liquid air return air, and meanwhile, residual cold in the multi-channel heat exchanger 12 is absorbed by circulating refrigerant, the cold is stored in the cold storage packed bed 20, and the cold is released in the hydrogen liquefying unit 3.
Because the liquid air energy storage unit 9 is an intermittent operation system, but the LNG supply unit is continuously operated, LNG is continuously supplied and conveyed, and through the design of the cold accumulation packed bed 20 and the multi-channel heat exchanger 12, when the energy storage part of the liquid air energy storage unit 9 does not operate, all cold energy of the LNG is stored in the cold accumulation packed bed 20, so that the efficient utilization of the cold energy of the LNG is ensured.
In some embodiments, as shown in fig. 1, the hydrogen liquefying unit 3 includes a pre-cooling cold box 4, and an inlet of a hot fluid channel 41 of the pre-cooling cold box 4 is connected with the wind-light power generation hydrogen producing unit, so that the hydrogen produced by the wind-light power generation hydrogen producing unit enters the hot fluid channel 41 of the pre-cooling cold box 4; the first cold fluid channel 42 of the pre-cooling cold box 4 is connected with the first cold fluid channel 123 of the multi-channel heat exchanger 12, so that LNG after heat exchange in the multi-channel heat exchanger 12 enters the pre-cooling cold box 4 to exchange heat with hydrogen, and the hydrogen is cooled. LNG from the LNG supply unit firstly carries out primary heat exchange in the multichannel heat exchanger 12 and then enters the precooling cold box 4 to carry out secondary heat exchange with hydrogen, so that the cascade utilization of LNG cold energy is realized. The NG subjected to heat exchange by the pre-cooling cold box 4 can directly enter an external transmission pipeline to carry out external transmission and gas supply, so that the LNG cold energy utilization rate reaches 100%.
Further, the hydrogen liquefying unit 3 further includes a cryogenic tank 5, and the hot fluid channel 51 of the cryogenic tank 5 is connected with the hot fluid channel 41 of the pre-cooling tank 4, so that the hydrogen after heat exchange in the pre-cooling tank 4 enters the hot fluid channel 51 of the cryogenic tank 5. The second hot fluid channel 122 of the multi-channel heat exchanger 12 is connected in series to the cold storage loop 201 of the cold storage packed bed 20, so that the circulating refrigerant in the cold storage loop 201 of the cold storage packed bed 20 exchanges heat with the LNG flowing through the first cold fluid channel 123 of the multi-channel heat exchanger 12 in the multi-channel heat exchanger 12, absorbs the cold energy of the LNG, and stores the absorbed cold energy of the LNG in the cold storage packed bed 20; the first cold fluid channel 52 of the cryogenic refrigerator 5 is connected in series to the cold release loop 202 of the cold storage packed bed 20, so that the circulating refrigerant in the cold release loop 202 of the cold storage packed bed 20 exchanges heat with the hydrogen flowing through the hot fluid channel 51 of the cryogenic refrigerator 5 in the cold fluid channel of the cryogenic refrigerator 5, and the cold energy stored in the cold storage packed bed 20 is released to the hydrogen, so that the hydrogen is cooled.
The hydrogen exchanges heat with the circulating refrigerant in the cold accumulation filling bed 20 of the liquid air energy storage unit 9 in the cryogenic box 5, namely, the cold energy of the LNG stored by the cold accumulation filling bed 20 is used for cryogenic cooling of the hydrogen, so that the cold energy of the LNG is effectively utilized, and the liquefaction of the hydrogen is realized.
In some embodiments, the hydrogen liquefying unit 3 further includes a hydrogen expander 6, a hydrogen separating tank 7 and a liquid hydrogen storage tank 8, the hydrogen subjected to heat exchange and temperature reduction by the cryogenic box 5 enters the hydrogen expander 6, is subjected to further pressure reduction and temperature reduction, and then enters the hydrogen separating tank 7, and the separated liquid hydrogen enters the liquid hydrogen storage tank 8 for storage, so that the liquefaction of the hydrogen is realized, and the transportation is convenient.
Specifically, as shown in fig. 1, an inlet of the hydrogen expander 6 is connected to an outlet of the hot fluid channel 51 of the cryogenic tank 5, an outlet of the hydrogen expander 6 is connected to an inlet of the hydrogen separation tank 7, and an outlet of the hydrogen separation tank 7 is connected to the liquid hydrogen storage tank 8, so that hydrogen cooled in the cryogenic tank 5 is depressurized and cooled by the hydrogen expander 6 and stored in the liquid hydrogen storage tank 8.
In some embodiments, after the liquid hydrogen enters the liquid hydrogen storage tank 8, if an endothermic evaporation phenomenon occurs to generate an evaporation gas, the evaporation gas and the liquid hydrogen return gas separated by the hydrogen separation tank 7 may participate in heat exchange of the cryogenic tank 5 and the precooling tank 4.
Specifically, as shown in fig. 1, the tops of the liquid hydrogen storage tank 8 and the hydrogen separation tank 7 are respectively connected to the inlet of the second cold fluid channel 53 of the cryogenic tank 5 through pipelines, the outlet of the second cold fluid channel 53 of the cryogenic tank 5 is connected to the inlet of the second cold fluid channel 43 of the pre-cooling tank 4, and the outlet of the second cold fluid channel 43 of the pre-cooling tank 4 is connected to the wind-solar power generation hydrogen production unit, so that liquid hydrogen return gas and evaporation gas enter the hydrogen outlet of the wind-solar power generation hydrogen production unit after heat exchange in the cryogenic tank 5 and the pre-cooling tank 4 in sequence, namely, finally return to the inlet of the wind-solar power generation hydrogen production unit to participate in the next hydrogen liquefaction process. Therefore, the utilization rate of the hydrogen is improved, cold energy contained in the liquid hydrogen returned gas is effectively utilized, and the utilization rate of the cold energy is improved.
In some embodiments, the circulating refrigerant in the cold storage packed bed 20 in the liquid air energy storage unit 9 and the first-stage cold energy of the liquid hydrogen return gas (the cold energy exchanged in the cryogenic cooling tank 5) can respectively participate in multistage series or parallel heat exchange according to the actual working condition. That is, in the hydrogen liquefaction process, all the evaporated gas and the liquid hydrogen return gas are used as cold sources to return to the cryogenic tank 5 and the precooling tank 4 to provide cold.
Further, the cryogenic tank 5 and the hydrogen expander 6 may be connected in series or in parallel in multiple stages to meet the requirement of hydrogen liquefaction.
As shown in fig. 1, the LNG supply unit includes an LNG supply line, an LNG transfer line, and an NG line, one end of the LNG supply line is connected to the LNG receiving station, the other end of the LNG supply line is connected to the inlet of the first cold fluid passage 123 of the multi-channel heat exchanger 12, one end of the LNG transfer line is connected to the outlet of the first cold fluid passage 123 of the multi-channel heat exchanger 12, the other end of the LNG transfer line is connected to the inlet of the first cold fluid passage 42 of the pre-cooling cold tank 4 of the hydrogen liquefaction unit 3, and the outlet of the first cold fluid passage 42 of the pre-cooling cold tank 4 is connected to the NG line. LNG firstly carries out primary heat exchange in the multi-channel heat exchanger 12 of the liquid air energy storage unit 9 for air liquefaction and cold accumulation of the cold accumulation packed bed 20, then enters the pre-cooling cold box 4 of the hydrogen liquefaction unit 3 for secondary heat exchange, cascade utilization of LNG cold energy is realized, high-pressure LNG is converted into high-pressure NG, namely, after the LNG passes through the multi-channel heat exchanger 12 and the multi-channel heat exchange of the pre-cooling cold box 4, the LNG is converted into the high-pressure NG by the high-pressure LNG, and the high-pressure NG can directly enter an external transmission pipeline for external transmission and gas supply, so that the utilization rate of the LNG cold energy reaches 100%.
The working process of the hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization is described below:
Firstly, the system starts to operate by the wind-light power generation unit 1, the electric energy generated by the wind-light power generation unit 1 is unstable and fluctuates periodically, the continuously stable electric energy is selected to enter the wind-light power generation hydrogen production unit for preparing hydrogen, and part of the periodic fluctuation is selected to enter the liquid air energy storage unit 9 for energy storage and peak shaving so as to realize green electricity surfing; and then, the hydrogen produced by the wind-solar power generation hydrogen production unit is liquefied by a hydrogen liquefaction unit for convenient transportation and reasonable gradient utilization of LNG cold energy.
In the hydrogen liquefying unit 3, hydrogen firstly exchanges heat with LNG second-stage cold energy and liquid hydrogen return gas second-stage cold energy through a precooling cold box 4, then enters a cryogenic cold box 5 to exchange heat with circulating refrigerant in an energy storage packed bed in a liquid air energy storage unit 9 and liquid hydrogen return gas first-stage cold energy, then enters a hydrogen separating tank 7 after being subjected to further depressurization and temperature reduction through a hydrogen expander 6, liquid hydrogen separated by the hydrogen separating tank 7 enters a liquid hydrogen storage tank 8, liquid hydrogen return gas in the hydrogen separating tank 7 and evaporation gas of the liquid hydrogen storage tank 8 are returned to the cryogenic cold box 5 and the precooling cold box 4 to participate in heat exchange, and finally returns to an inlet of the hydrogen liquefying unit 3 to participate in the next hydrogen liquefying process. Wherein, the cryogenic cooling tank 5 and the hydrogen expander 6 can be in a multistage series connection or parallel connection form to meet the requirement of hydrogen liquefaction; the circulating refrigerant in the cold accumulation packed bed 20 in the liquid air energy storage unit 9 and the first-stage cold energy of the liquid hydrogen return gas can respectively participate in multistage series or parallel heat exchange according to actual working conditions.
In the liquid air energy storage unit 9, air firstly enters the liquid air energy storage unit 9 through the air purification supercharging device 10, enters the compressor stage after being purified and supercharged through the air purification supercharging device 10, then is subjected to cooling heat exchange by the heat exchanger 11, high-pressure air is formed, heat generated by air compression is absorbed by circulating hot oil and stored in the heat storage packed bed 19, the high-pressure air enters the multi-channel heat exchanger 12 to exchange heat with LNG and liquid air return air from the liquid air storage tank 15 and the liquid air separation tank 14, residual cold energy in the multi-channel heat exchanger 12 is absorbed by circulating refrigerant, the cold energy is stored in the cold storage packed bed 20, and cold energy is released in the hydrogen liquefying unit 3 for liquefying hydrogen. The cooled air enters an air expander 13 and then enters a liquid-air separation tank 14, the separated liquid air enters a liquid air storage tank 15, and the low-temperature air separated from the liquid-air separation tank 14 and the evaporated gas evaporated from the liquid air storage tank 15 are all used as liquid air return gas to enter the multi-channel heat exchanger 12 to provide cold energy for air liquefaction. After being pressurized by a high-pressure pump 16, the liquid air in the liquid air storage tank 15 enters a heat exchanger 17 in front of a generator 18 to exchange heat with heat in a heat storage packed bed 19 by taking circulating hot oil as a medium, and then enters the generator 18 to generate power, so that unstable green power is regulated by peak shaving, and stable surfing of wind-solar power generation is realized.
In the present application, the liquid air energy storage unit 9 is intermittently operated, but the multi-channel heat exchanger 12 is continuously operated to efficiently absorb continuous LNG cold energy and store the same in the cold storage packed bed 20, so as to ensure the cold energy supply of the hydrogen liquefying unit 3.
The multi-channel heat exchanger 12 is arranged in a multi-stage heat exchange cascade manner so as to ensure efficient heat exchange between LNG, circulating refrigerant, liquid air return air and air.
According to the hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization, stable operation of the comprehensive energy system and high-quality cold energy and high-efficiency utilization of wind and light energy are realized through the circulating co-production of five working mediums, namely LNG, air, hydrogen, circulating refrigerant and circulating hot oil. Green hydrogen products can be produced, green electricity can be stably connected to the internet, high-pressure natural gas can be externally transmitted, and only LNG cold energy and renewable wind-light energy which are reasonably utilized are consumed, so that the efficient utilization and conversion of energy are realized. The method solves the problem that energy sources and energy cannot be utilized efficiently, and provides an engineering feasibility scheme for coupling co-production of a large-scale energy system.
The above description is intended to be illustrative and not limiting, and variations, modifications, alternatives, and variations of the above embodiments may be made by those of ordinary skill in the art within the scope of the present disclosure. Also, the above examples (or one or more aspects thereof) may be used in combination with each other, and it is contemplated that the embodiments may be combined with each other in various combinations or permutations.
Claims (9)
1. Hydrogen liquefaction coupling liquid air energy storage comprehensive energy system based on LNG cold energy utilization, characterized by comprising:
An LNG supply unit;
The wind-light power generation unit generates power by utilizing wind energy and solar energy, and has a first power generation state and a second power generation state, wherein in the first power generation state, the wind-light power generation unit can output first electric energy, and in the second power generation state, the wind-light power generation unit can output the first electric energy and second electric energy exceeding the first electric energy;
the wind-light power generation hydrogen production unit is used for producing hydrogen by utilizing the first electric energy output by the wind-light power generation unit;
The hydrogen liquefying unit is used for liquefying the hydrogen produced by the wind-solar power generation hydrogen production unit by utilizing the cold energy of the LNG in the LNG supply unit;
And the liquid air energy storage unit exchanges heat with the LNG in the LNG supply unit so as to liquefy the air and store energy, and the liquefied air is pressurized and then expanded to generate power and is combined with the second electric energy output by the wind-solar power generation unit to enter a power grid.
2. The hydrogen liquefaction coupling liquid air energy storage integrated energy system based on LNG cold energy utilization according to claim 1, wherein the liquid air energy storage unit comprises an air purification supercharging device, a compressor stage post heat exchanger, a multi-channel heat exchanger, an air expander, a liquid air separation tank, a liquid air storage tank, a high-pressure pump, a generator pre heat exchanger and a generator, the air sequentially passes through the air purification supercharging device, the heat exchange and cooling of the compressor-stage rear heat exchanger, then enters the first hot fluid channel of the multichannel heat exchanger, exchanges heat with LNG flowing through the first cold fluid channel of the multichannel heat exchanger, cools, then enters the liquid-air separation tank for gas-liquid separation after cooled by the air expander, and the separated liquid air enters the liquid air storage tank for storage; the high-pressure pump is connected with the liquid air storage tank and is used for pressurizing the liquid air in the liquid air storage tank and then sending the pressurized liquid air into the generator front heat exchanger for heat exchange and temperature rise, and the liquid air after temperature rise and gasification enters the generator for power generation.
3. The integrated energy system of hydrogen liquefaction coupling liquid air energy storage based on LNG cold energy utilization according to claim 2, wherein the tops of the liquid air storage tank and the liquid air separation tank are respectively connected with the inlets of the second cold fluid channels of the multi-channel heat exchanger, so that low-temperature air separated by the liquid air separation tank and evaporated gas evaporated in the liquid air storage tank are both used as liquid air return gas to enter the multi-channel heat exchanger to participate in heat exchange, release cold energy and raise temperature, and enter the inlet of the air purification supercharging device after heat exchange and temperature rise.
4. The LNG cold energy utilization based hydrogen liquefaction coupled liquid air energy storage integrated energy system of claim 2, wherein the liquid air energy storage unit further comprises a thermal storage packed bed connecting a thermal storage circuit and a heat release circuit;
The cold fluid channel of the post-compressor heat exchanger is connected in series with the heat storage loop of the heat storage packed bed, so that circulating hot oil in the heat storage loop of the heat storage packed bed exchanges heat with air flowing through the hot fluid channel of the post-compressor heat exchanger in the post-compressor heat exchanger, absorbs air compression heat, and stores the absorbed heat energy in the heat storage packed bed;
the heat fluid channel of the generator front heat exchanger is connected in series with the heat release loop of the heat storage packed bed, so that circulating hot oil in the heat release loop of the heat storage packed bed exchanges heat with liquid air flowing through the cold fluid channel of the generator front heat exchanger in the generator front heat exchanger, and heat energy stored in the heat storage packed bed is released to the liquid air.
5. The LNG cold energy utilization based hydrogen liquefaction coupled liquid air energy storage integrated energy system of claim 2, wherein the liquid air energy storage unit further comprises a cold storage packed bed connecting a cold storage loop and a cold release loop;
the second hot fluid channel of the multi-channel heat exchanger is connected in series on the cold storage loop of the cold storage packed bed, so that circulating refrigerant in the cold storage loop of the cold storage packed bed exchanges heat with LNG flowing through the first cold fluid channel of the multi-channel heat exchanger in the multi-channel heat exchanger, cold energy of the LNG is absorbed, and the absorbed cold energy of the LNG is stored in the cold storage packed bed;
The cold release loop of the cold accumulation packed bed is connected with the hydrogen liquefying unit and is used for providing cold energy stored by the cold accumulation packed bed for the hydrogen liquefying unit and liquefying hydrogen.
6. The integrated energy system of hydrogen liquefaction coupling liquid air energy storage based on LNG cold energy utilization according to claim 2, wherein the hydrogen liquefaction unit includes a pre-cooling cold box, an inlet of a hot fluid channel of the pre-cooling cold box is connected with the wind-solar power generation hydrogen production unit, so that hydrogen produced by the wind-solar power generation hydrogen production unit enters the hot fluid channel of the pre-cooling cold box; the first cold fluid channel of the pre-cooling cold box is connected with the first cold fluid channel of the multi-channel heat exchanger, so that LNG subjected to heat exchange in the multi-channel heat exchanger enters the pre-cooling cold box to exchange heat with hydrogen, and the hydrogen is cooled.
7. The LNG cold energy utilization based hydrogen liquefaction coupled liquid air energy storage integrated energy system of claim 6, wherein the hydrogen liquefaction unit further comprises a cryogenic tank, a hot fluid channel of the cryogenic tank is connected with a hot fluid channel of the pre-cooling tank, so that hydrogen after heat exchange of the pre-cooling tank enters the hot fluid channel of the cryogenic tank;
The second hot fluid channel of the multi-channel heat exchanger is connected in series on a cold storage loop of the cold storage packed bed, so that circulating refrigerant in the cold storage loop of the cold storage packed bed exchanges heat with LNG flowing through the first cold fluid channel of the multi-channel heat exchanger in the multi-channel heat exchanger, cold energy of the LNG is absorbed, and the absorbed cold energy of the LNG is stored in the cold storage packed bed; the first cold fluid channel of the cryogenic box is connected in series with the cold releasing loop of the cold storage packed bed, so that the circulating refrigerant in the cold releasing loop of the cold storage packed bed exchanges heat with the hydrogen flowing through the hot fluid channel of the cryogenic box in the cold fluid channel of the cryogenic box, and cold energy stored in the cold storage packed bed is released to the hydrogen, and the hydrogen is cooled.
8. The LNG cold energy utilization based hydrogen liquefaction coupled liquid air energy storage integrated energy system of claim 7, wherein the hydrogen liquefaction unit further comprises a hydrogen expander, a hydrogen separation tank and a liquid hydrogen storage tank, an inlet of the hydrogen expander is connected with an outlet of a hot fluid channel of the cryogenic tank, an outlet of the hydrogen expander is connected with an inlet of the hydrogen separation tank, and an outlet of the hydrogen separation tank is connected with the liquid hydrogen storage tank, so that hydrogen cooled by the cryogenic tank is depressurized and cooled by the hydrogen expander and stored in the liquid hydrogen storage tank.
9. The LNG cold energy utilization based hydrogen liquefaction coupled liquid air energy storage integrated energy system of claim 8, wherein the tops of the liquid hydrogen storage tank and the hydrogen separation tank are respectively connected to an inlet of a second cold fluid channel of the cryogenic tank, an outlet of the second cold fluid channel of the cryogenic tank is connected to an inlet of the second cold fluid channel of the pre-cooling tank, and an outlet of the second cold fluid channel of the pre-cooling tank is connected to the wind-solar power generation hydrogen production unit.
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| Publication Number | Publication Date |
|---|---|
| CN118273879A true CN118273879A (en) | 2024-07-02 |
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