Waste power and LNG (Liquefied Natural Gas) cold energy utilization mixing station

Abstract

The invention provides an abandoned electricity and LNG (liquefied natural gas) cold energy utilization mixing station which comprises a water electrolysis system, a first-stage cold utilization system, a second-stage cold utilization system, a third-stage cold utilization system and an abandoned electricity utilization system, the water electrolysis system is used for electrolyzing water to generate hydrogen and oxygen, the first-stage cold utilization system is used for providing cooling capacity for heat exchange and cooling of the hydrogen and the oxygen through LNG cold energy, and the second-stage cold utilization system is used for providing cooling capacity for heat exchange and cooling of the third-stage cold utilization system. The second-stage cold using system is used for making a cold storage medium capable of moving to a cold using place through LNG cold energy, and the third-stage cold using system is used for supplying cold energy to ice making operation of an ice factory through the LNG cold energy. According to the ice maker, hydrogen and oxygen prepared by electrolyzing water are sequentially subjected to precooling, cold storage medium preparation and ice making operation, so that the problem of energy storage by abandoning electricity is solved, and the energy-saving effect and the economic benefit are good.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of abandoned electricity and LNG cold energy utilization, and particularly relates to a mixed station for abandoned electricity and LNG cold energy utilization. BACKGROUND

[0002] The statements herein merely provide background technology related to the present application, and do not necessarily constitute prior art.

[0003] In the process of converting liquefied natural gas (LNG) into a gaseous state, the cold energy of the liquid state converted into a gaseous state is not utilized in the direct release by using an air vaporizer in a vaporization station, which causes waste of cold energy (about 830 kJ / kg LNG). In addition, due to the limited capacity of the local power transmission channel, part of the power generation of large-scale wind power or solar power stations cannot be fully consumed, resulting in the generation of abandoned electricity. The abandoned electricity is usually stored by using lithium battery energy storage equipment, but this method has a high cost. Therefore, the present application provides a mixed station for abandoned electricity and LNG cold energy utilization to solve the above problems. SUMMARY

[0004] The main purpose of the present application is to provide a mixed station for abandoned electricity and LNG cold energy utilization.

[0005] To achieve the above purpose, the technical solution of the present application is as follows: a mixed station for abandoned electricity and LNG cold energy utilization is located in a region where a natural power generation system is located, and comprises: a water electrolysis system for electrolyzing water to generate hydrogen and oxygen; a primary cold utilization system for providing cold energy for heat exchange and cooling of hydrogen and oxygen by using LNG cold energy; a liquid hydrogen preparation device for preparing hydrogen after heat exchange and cooling into a liquid state and storing; a liquid oxygen preparation device for preparing oxygen after heat exchange and cooling into a liquid state and storing; a secondary cold utilization system for making a movable cold storage medium to a cold utilization site by using LNG cold energy; a tertiary cold utilization system for supplying cold energy for ice making operation of an ice making plant by using LNG cold energy; and an abandoned electricity utilization system for providing power for operation of the water electrolysis system, the liquid hydrogen preparation device and the liquid oxygen preparation device by using abandoned electricity of the natural power generation system.

[0006] Further, the natural power generation system comprises a wind power station or a photovoltaic power station for converting natural energy into electric energy.

[0007] Further, the water electrolysis system comprises a plurality of electrolytic cells for electrolyzing water to generate hydrogen and oxygen.

[0008] Further, the primary cold utilization system comprises: An oxygen heat exchanger, an input end of which is externally connected with an oxygen pipe for inputting oxygen produced by the water electrolysis system, can utilize LNG cold energy to heat exchange and cool the oxygen. A hydrogen heat exchanger, an input end of which is externally connected with a hydrogen pipe for inputting hydrogen produced by the water electrolysis system, can utilize LNG cold energy to heat exchange and cool the hydrogen.

[0009] Further, the liquid oxygen preparation device comprises: a first compressor for compressing the heat-exchanged and cooled oxygen into liquid state to form liquid oxygen; and a liquid oxygen storage tank for storing the liquid oxygen.

[0010] Further, the liquid hydrogen preparation device comprises: a second compressor for compressing the heat-exchanged and cooled hydrogen into liquid state to form liquid hydrogen; and a liquid hydrogen storage tank for storing the liquid hydrogen.

[0011] Further, the secondary cold utilization system comprises an ice slurry preparation system for preparing ice slurry by using the refrigerant or antifreeze after absorbing the LNG cold energy, so as to use the ice slurry as the cold storage medium.

[0012] Further, the cold utilization site is a refrigeration house, a low-temperature grain warehouse, a data machine room or a regional cold supply system.

[0013] Further, the tertiary cold utilization system comprises a heat exchange tower located in an ice making plant, which is used to provide cold energy for ice making operation by utilizing LNG cold energy.

[0014] Further, the abandoned electricity utilization system comprises: a transformer for adjusting the voltage of the abandoned electricity of the natural power generation system; and a PLC cabinet for controlling the voltage-adjusted abandoned electricity to be respectively input to the water electrolysis system, the liquid hydrogen preparation device and the liquid oxygen preparation device.

[0015] The beneficial effects of the present application are embodied in: The abandoned electricity and LNG cold energy utilization mixed station of the present application can utilize the excess abandoned electricity of natural power generation to supply energy for hydrogen and oxygen production by electrolysis of water, and sequentially utilize LNG cold energy for precooling of hydrogen and oxygen produced by electrolysis of water, preparation of cold storage medium and ice making operation, so as to not only solve the problem of abandoned electricity energy storage, but also have good energy saving effect and economic benefit. BRIEF DESCRIPTION OF DRAWINGS

[0016] In the drawings: Figure 1 It is a layout schematic diagram of the mixed station of the present application.

[0017] Marked for explanation: 1, electrolytic cell; 2, oxygen pipe; 3, hydrogen pipe; 4, oxygen heat exchanger; 5, hydrogen heat exchanger; 6, liquid oxygen preparation device; 7, liquid hydrogen preparation device; 8, liquid oxygen storage tank; 9, liquid hydrogen storage tank; 10, LNG storage tank; 14, ice factory; 16, ice slurry preparation system; 20, transformer; 21, PLC cabinet; 22, heat exchange wing; 23, gas pipeline. DETAILED DESCRIPTION

[0018] The application will be described in further detail below with reference to the drawings and embodiments. It is apparent that the described embodiments are only a part of the embodiments of the application, and not all the embodiments. The embodiments in the application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0019] Please combine Figure 1 , the abandoned electricity and LNG cold energy utilization mixed station is located in the area of the natural power generation system, and includes a water electrolysis system, a primary cold utilization system, a liquid oxygen preparation device 6, a liquid hydrogen preparation device 7, a secondary cold utilization system, a tertiary cold utilization system, and an abandoned electricity utilization system.

[0020] The water electrolysis system is used for electrolyzing water to generate hydrogen and oxygen; The primary cold utilization system is used for providing cold energy for heat exchange and cooling of hydrogen and oxygen by using LNG cold energy; The liquid oxygen preparation device 6 is used for preparing the cooled oxygen into liquid state and storing; The liquid hydrogen preparation device 7 is used for preparing the cooled hydrogen into liquid state and storing; The secondary cold utilization system is used for making a movable cold storage medium to a cold utilization place by using LNG cold energy; The tertiary cold utilization system is used for supplying cold energy for ice making operation of the ice factory 14 by using LNG cold energy; and The abandoned electricity utilization system uses the abandoned electricity of the natural power generation system to provide electric energy for operation of the water electrolysis system, the liquid hydrogen preparation device, and the liquid oxygen preparation device.

[0021] In the specific implementation, the water electrolysis system is arranged near the area of the natural power generation system with more abandoned electricity, water is decomposed into oxygen and hydrogen, and the cold energy of LNG is utilized in stages, -162℃ to -100℃ is used for making liquid oxygen and liquid hydrogen, -162℃ to -20℃ is used for preparing a cold storage medium (ice slurry) (direct contact method), the cold storage medium can be used for fishery freezing and multi-temperature zone cold storage system, and -20℃ to 0℃ is used for ice making.

[0022] It should be noted that even without the abandonment of electricity, the secondary and tertiary cold systems of LNG can still be used. If the demand for liquid oxygen or liquid hydrogen is large and the abandonment of electricity cannot meet the use, the low-price city electricity can be used to electrolyze water.

[0023] In addition, according to the actual situation of the surrounding liquid hydrogen consumption market, a hydrogenation and LNG mixing station can be built next to it to solve the problem of liquid hydrogen storage and sales.

[0024] In an embodiment, the natural power generation system includes a wind power plant or a photovoltaic power plant for converting natural energy into electrical energy.

[0025] In an embodiment, the water electrolysis system includes a plurality of electrolytic cells 1 for electrolyzing water to produce hydrogen and oxygen.

[0026] In an embodiment, the primary cold system includes an oxygen heat exchanger 4 and a hydrogen heat exchanger 5. The input end of the oxygen heat exchanger 4 is connected to the oxygen pipe 2 to input the oxygen produced by the water electrolysis system, and the oxygen can be heat-exchanged and cooled by the cold energy of LNG. The input end of the hydrogen heat exchanger 5 is connected to the hydrogen pipe 3 to input the hydrogen produced by the water electrolysis system, and the hydrogen can be heat-exchanged and cooled by the cold energy of LNG.

[0027] It should be noted that the cold energy of LNG with a temperature range of -162℃-100℃ is used to heat-exchange and cool the oxygen and hydrogen.

[0028] In an embodiment, the liquid oxygen preparation device 6 includes a first compressor and a liquid oxygen storage tank 8. The first compressor is an air compressor. The first compressor is used to compress the heat-exchanged and cooled oxygen into liquid oxygen. The liquid oxygen storage tank 8 is used to store the liquid oxygen.

[0029] It should be noted that the boiling point of liquid oxygen is -182.96°C (90.19 K), which is a relatively easy-to-liquefy gas. Through a cycle composed of air compressors, heat exchangers, etc., the heat of the gas is continuously removed, and finally it is cooled below the boiling point and liquefied, specifically: S1, compression: the heat-exchanged and cooled oxygen is first compressed to high pressure (usually tens to two hundred atmospheres) by an air compressor, and heat is generated during the compression process.

[0030] S2, heat exchange again: the purified high-pressure oxygen flows into the main heat exchanger (usually a plate-fin heat exchanger) for heat exchange, so as to be gradually cooled to near the liquefaction temperature.

[0031] S3, storage: the generated liquid oxygen flows into the liquid oxygen storage tank 8 (vacuum adiabatic Dewar) for storage.

[0032] In an embodiment, the liquid hydrogen production device 7 comprises a second compressor and a liquid hydrogen storage tank 9. The second compressor is a hydrogen compressor. The second compressor is used to compress the heat-exchanged and cooled hydrogen to a liquid state to form liquid hydrogen. The liquid hydrogen storage tank 9 is used to store the liquid hydrogen.

[0033] It is to be noted that the boiling point of liquid hydrogen is extremely low, -252.87°C (20.28 K), and the liquefaction is much more difficult than that of liquid oxygen. It needs to be pre-cooled to a very low temperature (below its conversion temperature 204 K) before the throttling effect takes effect, and a pre-cooling Claude cycle or other more complex cycles must be used. The hydrogen gas is first pre-cooled to below its conversion temperature using a coolant such as liquid nitrogen, and then liquefied by a combination of isentropic expansion (expander work) and throttling expansion to provide a large amount of refrigeration, which is specifically: S1, compression: the cooled hydrogen is first pressurized by a hydrogen compressor to form high-pressure hydrogen, which is divided into two paths. Most of the gas enters an expander (turbine expander or piston expander). The gas is adiabatically expanded in the expander, doing work on the outside, and the temperature and pressure drop sharply, producing a large amount of cold. This extremely cold gas is returned to cool the normal flow of high-pressure hydrogen.

[0034] S2, throttling expansion and liquefaction: the other small part of the pre-cooled high-pressure hydrogen is further cooled in the main heat exchanger by the return of cold hydrogen from the expander and the storage tank, and finally expanded by a throttling valve (J-T valve). At this time, most of the hydrogen is liquefied.

[0035] S3, gas-liquid separation and storage: the liquefied hydrogen flows into the liquid hydrogen storage tank for gas-liquid separation. The flash gas produced as a cold source is returned to the main heat exchanger for final recovery. The extremely low temperature liquid hydrogen is stored in an adiabatic liquid hydrogen storage tank 9.

[0036] In an embodiment, the secondary cooling system comprises an ice slurry production system 16 for producing ice slurry using the refrigerant or antifreeze after absorbing the cold of LNG, taking the ice slurry as the cold storage medium. The cooling site can be a cold storage, a low-temperature grain storehouse, a data center or a regional cooling system.

[0037] It is to be noted that the ice slurry production system 16 is to cool water or aqueous solution below its freezing point to cause phase change (freezing), and to timely strip, break and mix the ice crystals produced by mechanical or physical methods, so as to form a uniform, pumpable slurry. An ice slurry generator can be used as an ice slurry production device.

[0038] In an embodiment, the tertiary cooling system comprises a heat exchange pry 22 in the ice making plant 14, which is used to provide cold energy for ice making operation using LNG cold energy.

[0039] It should be noted that the heat exchange pry 22 of the ice factory is a core equipment used in the refrigeration system, mainly used for realizing the exchange of cold and heat energy. Its core working principle is similar to that of the heat exchanger, and through the structures such as the tube shell type and the fixed tube plate type, the LNG cold energy is exchanged with water to make the water temperature drop to below 0℃ to form ice crystals.

[0040] In an embodiment, the abandoned power utilization system comprises a transformer 20 and a PLC cabinet 21. The transformer 20 is used to adjust the abandoned power voltage of the natural power generation system; and the PLC cabinet 21 is used to control the adjusted abandoned power to be respectively input to the water electrolysis system, the liquid hydrogen preparation device and the liquid oxygen preparation device.

[0041] In summary, the abandoned power generated by the wind power plant or the photovoltaic power plant is input to the transformer 20 through the input cable of the plant, and is input to the electrolytic cell 1 and the entire plant station through the PLC cabinet 21. After the electrolysis of water, the oxygen and hydrogen generated by the anode and the cathode respectively enter the oxygen heat exchanger 4 and the hydrogen heat exchanger 5 through the oxygen pipe 2 and the hydrogen pipe 3. The cooled oxygen enters the liquid oxygen preparation device 6 (the excess power of the abandoned power can be used) to become liquid oxygen and is stored in the liquid oxygen storage tank 8. The cooled hydrogen enters the liquid hydrogen preparation device 7 (the excess power of the abandoned power can be used) to become liquid hydrogen and is stored in the liquid hydrogen storage tank 9. The LNG in the LNG storage tank 10 is simultaneously input to the oxygen heat exchanger 4 and the hydrogen heat exchanger 5 to realize the first-level utilization of the LNG cold energy.

[0042] The LNG pipeline passes through the ice slurry preparation system 16, and the LNG at-162℃ to-20℃ is used for ice slurry preparation (direct contact method). The ice slurry is prepared by using the refrigerant or antifreeze after absorbing the LNG cold energy, and the ice slurry is used as a cold storage medium. The ice slurry is transported to places needing cooling such as refrigeration warehouses, low-temperature grain stores, data machine rooms and regional cooling systems by vehicles and ships to realize the second-level utilization of the LNG cold energy.

[0043] The LNG pipeline passes through the heat exchange pry 22 of the ice factory 14, and the LNG at-20℃ to 0℃ is sold to merchants after being made into ice to realize the third-level utilization of the LNG cold energy.

[0044] In addition, the liquid hydrogen storage tank 9 can be connected in flow linkage with the gas pipeline 23 of the city and town through the hydrogen mixing control device, so that the hydrogen enters the gas pipeline 23 of the city and town to be mixed with the natural gas to improve the combustion efficiency of the natural gas.

[0045] The above only describes the preferred embodiments of the present application and should not be used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

[0046] It should be noted that if the invention embodiments involve directional indications (such as up, down), the directional indications are only used to explain the relative position relationship, movement, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0047] In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, if the invention embodiments involve "first", "second" and the like, the "first", "second" and the like are only for description purposes, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "multiple" means more than two. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor within the scope of the invention.

Claims

1. A hybrid station for abandoned electricity and LNG cold energy utilization, characterized in that, Comprise: a water electrolysis system for electrolyzing water to produce hydrogen and oxygen; a primary cold utilization system for providing cold energy for heat exchange and cooling of hydrogen and oxygen respectively by using cold energy of LNG; a liquid hydrogen preparation device (7) for preparing hydrogen after heat exchange and cooling into liquid state and storing; a liquid oxygen preparation device (6) for preparing oxygen after heat exchange and cooling into liquid state and storing; a secondary cold utilization system for making cold storage medium which can be moved to a cold utilization site by using cold energy of LNG; a tertiary cold utilization system for supplying cold energy for ice making operation of an ice making plant (14) by using cold energy of LNG; and an abandoned electricity utilization system for providing electricity for operation of the water electrolysis system, the liquid hydrogen preparation device (7) and the liquid oxygen preparation device (6) respectively by using abandoned electricity of a natural power generation system.

2. The power curtailment and LNG cold energy utilization hybrid station of claim 1, wherein, The water electrolysis system comprises a plurality of electrolytic cells (1) for electrolyzing water to produce hydrogen and oxygen.

3. The power curtailment and LNG cold energy utilization hybrid station of claim 1, wherein, The primary cold utilization system comprises: an oxygen heat exchanger (4) having an oxygen pipe (2) connected to an input end thereof for inputting oxygen produced by the water electrolysis system, and capable of using cold energy of LNG to heat exchange and cool the oxygen; and a hydrogen heat exchanger (5) having a hydrogen pipe (3) connected to an input end thereof for inputting hydrogen produced by the water electrolysis system, and capable of using cold energy of LNG to heat exchange and cool the hydrogen.

4. The power curtailment and LNG cold energy utilization hybrid station of claim 1, wherein, The liquid oxygen preparation device (6) comprises: a first compressor for compressing oxygen after heat exchange and cooling into liquid state to form liquid oxygen; and a liquid oxygen storage tank (8) for storing the liquid oxygen.

5. The hybrid station for rejecting power and utilizing LNG cold energy according to claim 1, wherein, The liquid hydrogen preparation device (7) comprises: a second compressor for compressing hydrogen after heat exchange and cooling into liquid state to form liquid hydrogen; and a liquid hydrogen storage tank (9) for storing the liquid hydrogen.

6. The power curtailment and LNG cold energy utilization hybrid station of claim 1, wherein, The secondary cold utilization system comprises an ice slurry preparation system (16) for preparing ice slurry by using refrigerant or antifreeze after absorbing cold energy of LNG, and taking the ice slurry as the cold storage medium.

7. The hybrid station for rejecting power and utilizing LNG cold energy according to claim 1, wherein, The cold utilization site is a refrigerator, a low-temperature grain warehouse, a data machine room or a regional cold supply system.

8. The hybrid station for rejecting power and utilizing LNG cold energy according to claim 1, wherein, The tertiary cold utilization system comprises a heat exchange tower (22) in the ice making plant (14) for providing cold energy for ice making operation by using cold energy of LNG.

9. The power curtailment and LNG cold energy utilization hybrid station of claim 1, wherein, The abandoned electricity utilization system comprises: a transformer (20) for adjusting voltage of abandoned electricity of the natural power generation system; and a PLC cabinet (21) for controlling the voltage-adjusted abandoned electricity to be supplied to the water electrolysis system, the liquid hydrogen preparation device (7) and the liquid oxygen preparation device (6) respectively.

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