阅读说明：本技术 一种多联供液化空气储能系统及优化控制方法 (Multi-connected liquid supply air energy storage system and optimization control method ) 是由 刘琨 厉明 韦古强 何子睿 崔双双 宋锦涛 刘乙学 胡从川 刘广东 李红 于 2021-06-08 设计创作，主要内容包括：本发明属于液化空气储能技术领域,特别涉及一种耦合吸收式制冷机,能够实现热量梯级利用、回收利用的多联供液化空气储能系统；同时涉及一种能够实现冷、热、电、新风多联供的液化空气储能优化控制方法。系统包括储能单元、释能单元、蓄热单元、多联供单元以及控制单元。本发明解决了现有液化空气储能技术中储能效率低、供能单一的问题,充分利用液化空气储能系统中的富余热能和级后排气,在产生电能的同时,能够灵活的供应热能、冷能和新风,满足多种供能需求,同时达到经济,环保,高效的目的。(The invention belongs to the technical field of liquefied air energy storage, and particularly relates to a coupling absorption type refrigerator, which is a multi-connected liquid supply liquefied air energy storage system capable of realizing gradient utilization and recycling of heat; meanwhile, the method for optimally controlling the energy storage of the liquefied air can realize multi-combined supply of cold, heat, electricity and fresh air. The system comprises an energy storage unit, an energy release unit, a heat storage unit, a multi-connection supply unit and a control unit. The invention solves the problems of low energy storage efficiency and single energy supply in the existing liquefied air energy storage technology, fully utilizes surplus heat energy and post-stage exhaust in the liquefied air energy storage system, can flexibly supply heat energy, cold energy and fresh air while generating electric energy, meets various energy supply requirements, and simultaneously achieves the purposes of economy, environmental protection and high efficiency.)

1. The utility model provides a confession liquid air energy storage system more ally, includes energy storage unit, energy release unit, heat accumulation unit, supplies unit and the control unit more, its characterized in that:

the multi-connected liquid supply gasification air energy storage system energy storage unit comprises an air purifier, a compressor (set), a cooler, a cold accumulation heat regenerator, a throttle valve, a gas-liquid separator and a liquid storage tank which are sequentially connected through pipelines.

2. Wherein, the air outlet of the last stage cooler is connected with the air inlet of the cold accumulation heat regenerator.

3. The multi-connected liquid supply gasification air energy storage system energy release unit comprises a liquid storage tank, a liquid pump, a cold accumulation heat regenerator, a reheater, an expander (set) and a valve which are connected in sequence through pipelines.

4. Wherein, the air outlet of the cold accumulation heat regenerator is connected with the air inlet of the first-stage reheater; the high-temperature storage tank is connected with a heat-conducting oil inlet of the reheater through a valve.

5. The heat storage unit of the multi-connected liquid supply and gasification air energy storage system comprises a cooler, a reheater, a high temperature storage tank and a low temperature storage tank.

6. Wherein, the heat-conducting oil outlet of the cooler is connected with the high-temperature storage tank, and the heat-conducting oil inlet of the cooler is connected with the low-temperature storage tank.

7. The multi-connected liquid supply air energy storage system comprises a high-temperature storage tank, a low-temperature storage tank, a heat exchanger, an absorption refrigerator and a mixer; the surplus heat conducting oil outlet of the high-temperature storage tank is connected with a heat conducting oil inlet of the absorption refrigerator through a valve, the heat conducting oil outlet of the absorption refrigerator and the heat conducting oil outlet of the reheater flow through a mixer, the outlet of the mixer is connected with the heat conducting oil inlet of a heat exchanger, and the heat conducting oil outlet of the heat exchanger is connected with the low-temperature storage tank; the post-stage exhaust of the expansion process is connected to the air inlet of one heat exchanger and the water outlets of both heat exchangers are passed through the other mixer.

8. The control unit of the multi-connected liquid supply liquefied air energy storage system mainly comprises two valves.

9. One valve is located between the high temperature storage tank and the reheater, and the other valve is located between the high temperature storage tank and the absorption chiller.

10. -the compressor(s) and the expander(s) of the multiple feed liquefied air energy storage system are connected by means of a generator/motor.

11. A multi-connected liquefied air energy storage system as claimed in claim 1, wherein during the compression process, the ambient air is purified by an air purifier, the compressor consumes electric energy to compress the purified air, the air is raised in pressure and temperature, in order to collect the heat, a cooler is disposed between compressor stages, and heat transfer oil is used as a heat transfer medium to absorb the heat generated during the compression process and store the heat in a high temperature storage tank.

12. A multi-connected liquefied air energy storage system as claimed in claim 1, wherein after the compression process, the cooled high pressure air needs to be cooled and depressurized again to reach the air liquefaction critical point (0.1 MPa, -194.4 ℃) for liquefaction.

13. In order to further cool the air, a cold accumulation heat regenerator is applied after the compression process, the cold accumulation heat regenerator absorbs the heat of the air to cool the air, a throttle valve is applied afterwards, and the high-pressure low-temperature air is liquefied after passing through the throttle valve.

14. Finally, the liquefied air is stored in a liquid storage tank through a gas-liquid separator, and the unliquefied air is discharged into the atmosphere after releasing cold energy in a cold accumulation heat regenerator.

15. A multi-connected liquefied air energy storage system according to claim 1, wherein during the energy release process, the liquid air in the liquid storage tank is pressurized by a liquid pump and then gasified by absorbing heat through a cold storage regenerator.

16. Before the gaseous air enters the expander to do work, the gaseous air needs to absorb heat in the reheater to be heated, and the high-temperature air enters the expander to do work.

17. The multi-connected liquid supply air energy storage system as claimed in claim 1, wherein one absorption refrigerator and two heat exchangers are used in the multi-connected liquid supply system to ensure that surplus heat energy and post-stage exhaust gas in the energy storage system are fully utilized and multi-connected supply is realized.

18. The absorption refrigerator takes surplus high-temperature heat conduction oil as a driving heat source to generate cold energy, the two heat exchangers collect waste heat of the heat conduction oil and waste heat of exhaust gas after the stage for supplying heat, the exhaust gas after the stage is used for supplying fresh air after the waste heat is absorbed, the whole process does not release any pollution to the environment, and the purposes of high efficiency and environmental protection are achieved.

19. The multi-connected liquid supply gasification air energy storage system according to claim 1, wherein the optimization control method is characterized in that when the electric energy demand of the system is greater than the heat energy demand and the cold energy demand, a high-temperature heat conduction oil valve in front of a reheater is preferentially opened to supply heat to the reheater in the expansion process, the air temperature in front of an expander is increased, and the electric energy output of the system is ensured.

20. When the cold energy demand of the system is greater than the heat energy demand and the electric energy demand, the high-temperature heat conduction oil valve in front of the absorption refrigerator is preferentially opened in the expansion process to provide a heat source for the absorption refrigerator, so that the cold energy output of the system is ensured.

21. When the heat energy demand of the system is greater than the cold energy demand and the electric energy demand, a high-temperature heat conduction oil valve in front of the absorption refrigerator is preferentially opened in the expansion process, the absorption refrigerator is set to be out of work, and the heat energy output of the system is ensured by increasing the heat supply temperature.

Technical Field

The invention belongs to the technical field of liquefied air energy storage, and particularly relates to a coupling absorption type refrigerator, which is a multi-connected liquid supply liquefied air energy storage system capable of realizing gradient utilization and recycling of heat; meanwhile, the method for optimally controlling the energy storage of the liquefied air can realize multi-combined supply of cold, heat, electricity and fresh air.

Background

The concept of compressed air energy storage using naturally occurring underground caverns was first proposed by Stal Laval in 1949, and mainly aims to store compressed high-pressure air in natural caverns, thereby achieving energy storage. Liquefied air energy storage is one of compressed air energy storage technologies, and the principle is very similar to the compressed air energy storage technology, but the liquefied air energy storage system adopts liquid air for electric energy storage, and has higher energy storage density. The working principle is as follows: in the compression process, the compressor is used for consuming electric energy to compress the ambient air to a high-temperature high-pressure state, the interstage cooler is used for cooling the compressed air, and the heat conduction oil is used as a heat transfer medium to absorb heat and then is stored in the high-temperature storage tank. In the process of liquefying and storing, high-pressure air is cooled again in the heat regenerator, and high-pressure low-temperature air is liquefied through the throttle valve and then stored in the liquid storage tank. In the expansion process, liquid air is pressurized by a liquid pump and heated and gasified in a heat regenerator, high-pressure air is heated again in a front heat exchanger of the expander, heat transfer oil is used as a heat transfer medium to release heat and then stored in a low-temperature storage tank, and finally, high-pressure high-temperature air enters the expander to do work. However, the expansion process in the existing liquefied air energy storage system cannot completely consume the heat stored in the compression process, and a large amount of heat energy is surplus, so that the cycle efficiency is low.

The invention provides a multi-connection liquid supply liquefied air energy storage system and an optimization control method based on the aim of solving the problems of low energy storage efficiency and single energy supply in the existing liquefied air energy storage technology. The multi-joint supply means that surplus heat energy and exhaust gas in the liquefied air energy storage system are utilized to supply cold energy, heat energy and fresh air so as to improve the utilization efficiency of the system. In addition, the demands for cold, heat and electricity in the user side energy storage scene are very obvious, so that the multi-connected liquid supply liquefied air energy storage system can be suitable for various application occasions and has wide application prospects.

Disclosure of Invention

The invention aims to disclose a multi-connected liquid supply liquefied air energy storage system and an optimization control method, which can make full use of surplus heat energy and post-stage exhaust in the liquefied air energy storage system, and can flexibly supply heat energy, cold energy and fresh air while generating electric energy. The problem of energy storage system inefficiency has not only been solved, satisfies multiple energy supply demand, reaches economy simultaneously, environmental protection, efficient purpose.

The confession liquid air energy storage system that ally oneself with more includes: the device comprises an energy storage unit, an energy release unit, a heat storage unit, a multi-connection supply unit and a control unit. During energy storage, the compressor is driven by the surplus electricity or the valley electricity to compress and purify the air to a high-temperature and high-pressure state, the high-pressure air is liquefied and stored in a liquid storage tank after passing through a cold accumulation heat regenerator and a throttle valve after being cooled by an interstage cooler, and meanwhile, the compression heat is collected and stored in the high-temperature storage tank. When releasing energy, after the liquid air is pressurized by the liquid pump, the liquid air is gasified by utilizing the heat absorbed by the cold accumulation heat regenerator, and is heated by the reheater into high-temperature high-pressure air, and the high-temperature high-pressure air drives the expander to do work. And the surplus high-temperature heat conduction oil is used as a heat source of the absorption refrigerator to generate cold energy for cooling. The heat conducting oil after being absorbed by the absorption refrigerator is mixed with the heat conducting oil flowing out of the reheater, and the heat conducting oil is stored in the low-temperature storage tank after being exchanged with heat by the first heat exchanger. And the second heat exchanger is used for cooling the exhaust gas after the expansion process stage to supply fresh air. And collecting the hot water after the heat exchange of the two heat exchangers for supplying heat.

The multi-connected liquid supply air energy storage system energy storage unit comprises an air purifier, a compressor (set), a cooler, a cold accumulation heat regenerator, a throttle valve, a gas-liquid separator and a liquid storage tank which are sequentially connected through pipelines.

The multi-connected liquid supply gasification air energy storage system energy release unit comprises a liquid storage tank, a liquid pump, a cold accumulation heat regenerator, a reheater and an expansion machine (set) which are sequentially connected through pipelines.

The heat storage unit of the multi-connected liquid supply air energy storage system comprises a cooler, a reheater, a high-temperature storage tank and a low-temperature storage tank.

The multi-connected liquid supply air energy storage system comprises a high-temperature storage tank, a low-temperature storage tank, a heat exchanger, an absorption refrigerator and a mixer.

The multi-connected liquid supply air energy storage system control unit mainly comprises two valves. One valve is located between the high temperature storage tank and the reheater, and the other valve is located between the high temperature storage tank and the absorption chiller.

And the compressor (group) and the expansion machine (group) of the multi-connected liquid-feed liquefied air energy storage system are connected through a generator/motor.

The multi-connected liquid supply gasification air energy storage system uses one absorption refrigerator and two heat exchangers to ensure that heat energy and post-stage exhaust in the system are fully utilized, the absorption refrigerator uses redundant high-temperature heat conduction oil as a heat source to drive and generate cold energy for cooling, and the heat exchangers use water as a heat exchange medium to collect heat in the heat conduction oil waste heat and the exhaust waste heat for supplying heat. And the cooled stage is exhausted to supply fresh air. Therefore, the multi-connected liquid supply air energy storage system becomes an energy storage system with high energy storage efficiency and diversified energy supply, and no pollution is generated to the environment in the whole circulation process.

The multi-connected liquid supply air energy storage system considers the influence of air cleanliness on mechanical performance, and therefore an air purifier is arranged in front of a first-stage compressor of the system to purify air, mechanical damage in the operation process of the system is reduced, and meanwhile, the supply of fresh air is guaranteed.

The method for optimally controlling the multi-connected liquid supply liquefied air energy storage system comprises the following steps: when the electric energy demand of the system is greater than the heat energy demand and the cold energy demand, a high-temperature heat conduction oil valve in front of the reheater is preferentially opened to supply heat to the reheater in the expansion process, the air temperature in front of the expander is increased, and the electric energy output of the system is ensured. When the cold energy demand of the system is greater than the heat energy demand and the electric energy demand, the high-temperature heat conduction oil valve in front of the absorption refrigerator is preferentially opened in the expansion process to provide a heat source for the absorption refrigerator, so that the cold energy output of the system is ensured. When the heat energy demand of the system is greater than the cold energy demand and the electric energy demand, a high-temperature heat conduction oil valve in front of the absorption refrigerator is preferentially opened in the expansion process, the absorption refrigerator is set to be out of work, and the heat energy output of the system is ensured by increasing the heat supply temperature.

The innovation points of the invention are as follows: firstly, utilizing the exhaust gas after the expansion machine stage to supply fresh air; secondly, the surplus heat conduction oil is used for driving the absorption refrigerator to generate cold energy for cooling; thirdly, heat transfer oil waste heat and post-stage exhaust waste heat are collected by a heat exchanger to supply heat; fourthly, surplus heat energy in the liquefied air energy storage system is fully utilized, and the energy storage efficiency of the system is greatly improved; fifthly, the whole circulating system does not produce any pollution, can meet the requirement of multi-energy supply, and can play a better role in an energy storage scene.

Drawings

FIG. 1 is a schematic structural diagram of a multi-connected liquid-supply air energy storage system of the invention;

fig. 2 is a schematic structural diagram of a four-stage compression-four-stage expansion state of the multi-liquid liquefied air energy storage system.

Reference numerals in the figures

As shown in fig. 2, wherein: 1-an air purifier; 2-compressor 1; 3-compressor 2; 4-compressor 3; 5-compressor 4; 6-cold storage regenerator; 7-a throttle valve; 8-a gas-liquid separator; 9-a liquid storage tank; 10-a liquid pump; 11-an expander 1; 12-an expander 2; 13-an expander 3; 14-an expander 4; 15-a cooler 1; 16-a cooler 2; 17-a cooler 3; 18-a cooler 4; 19-reheater 1; 20-reheater 2; 21-reheater 3; 22-reheater 4; 23-a high-temperature storage tank; 24-absorption chiller; 25-heat exchanger 1; 26-mixer 1; 27-a low temperature storage tank; 28-heat exchanger 2; 29-mixer 2; 30-control valve 1; 31-control valve 2.

Detailed Description

The invention provides a multi-connected liquid supply air energy storage system and an optimization control method, and the invention is further explained with reference to the accompanying drawings and the specific implementation mode.

The invention can be realized based on the system, the specific structure of which is shown in fig. 2, the system is composed of an air purifier, a compressor 1, a compressor 2, a compressor 3, a compressor 4, a cold accumulation regenerator, a throttle valve, a gas-liquid separator, a liquid storage tank, a liquid pump, an expander 1, an expander 2, an expander 3, an expander 4, a cooler 1, a cooler 2, a cooler 3, a cooler 4, a reheater 1, a reheater 2, a reheater 3, a reheater 4, a high-temperature storage tank, an absorption refrigerator, a heat exchanger 1, a mixer 1, a low-temperature storage tank, a heat exchanger 2, a mixer 2, a control valve 1 and a control valve 2, and the specific operation process is as follows:

as shown in fig. 2, during the compression process, ambient air is first purified using an air purifier. And then, consuming redundant electric energy or valley electric energy, compressing the purified air to a high-temperature and high-pressure state by using the compressor 1, the compressor 2, the compressor 3 and the compressor 4, cooling the high-pressure and high-temperature air by using the interstage cooler 1, the cooler 2, the cooler 3 and the cooler 4, and storing the heat-conducting oil serving as a heat transfer medium in a high-temperature storage tank after absorbing heat.

In the process of liquefaction storage, high-pressure low-temperature air discharged by the cooler 4 is cooled by the cold accumulation heat regenerator and is liquefied by the throttle valve. After passing through the gas-liquid separator, the liquefied air is stored in the liquid storage tank, and the unliquefied air is discharged into the atmosphere after being cooled by the cold storage heat regenerator.

In the expansion process, liquid air in the liquid storage tank is pressurized by a liquid pump, then is gasified by absorbing heat by a cold accumulation heat regenerator, gaseous air is heated by a pre-reheater 1, a reheater 2, a reheater 3 and a reheater 4, and high-pressure and high-temperature air enters an expander 1, an expander 2, an expander 3 and an expander 4 to perform expansion work.

And the surplus high-temperature heat conduction oil in the high-temperature storage tank is used as a driving heat source to drive the absorption refrigerator to generate cold energy, then, a heat conduction oil outlet of the absorption refrigerator is mixed with low-temperature heat conduction oil flowing out of the pre-reheater 1, the reheater 2, the reheater 3 and the reheater 4 in the mixer 1, and the mixed oil is subjected to heat exchange by the heat exchanger 1 and then stored in the low-temperature storage tank. The 4-stage rear exhaust of the expansion machine is used for supplying fresh air after heat exchange through the heat exchanger 2, and water is used as a heat transfer medium to supply heat after the heat exchanger 1 and the heat exchanger 2 absorb the waste heat of heat transfer oil and the waste heat of the stage rear exhaust.

When the electric energy demand of the system is greater than the heat energy demand and the cold energy demand, the control valve 1 is preferentially opened, and the electric energy output of the system is ensured by increasing the front temperature of the expansion machine. When the cold energy demand of the system is greater than the heat energy demand and the electric energy demand, the control valve 2 is preferentially opened to provide a heat source for the absorption refrigerator, and the cold energy output of the system is ensured. When the heat energy demand of the system is greater than the electric energy demand and the cold energy demand, the control valve 2 is preferentially opened, the absorption refrigerator is set to be out of work, and the heat energy output of the system is ensured by increasing the heat supply temperature.

The above embodiments of the present invention are illustrative of the present invention and are not intended to limit the present invention. The claims set forth below point out the spirit and scope of the claimed invention, and the foregoing description does not constitute a complete disclosure of the invention. Therefore, any changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.