阅读说明：本技术 错级回热式压缩空气储能系统 (Staggered regenerative compressed air energy storage system ) 是由 刘当武 梅生伟 郑天文 高博 陈来军 薛小代 谢毓广 李伟 陈锋 徐斌 陈凡 于 2019-10-17 设计创作，主要内容包括：本发明提供一种错级回热式压缩空气储能系统,错级回热式压缩空气储能系统包括：前级压缩机、吸热器、后级压缩机、储气装置、第一蓄热装置、第二蓄热装置、前级回热器、后级回热器、前级膨胀机、后级膨胀机；其中前级压缩机的出口、吸热器的第一侧、后级压缩机、储气装置、前级回热器的第一侧、前级膨胀机、后级回热器的第一侧、后级膨胀机的进口顺次连接；吸热器的第二侧、第一蓄热装置、后级回热器的第二侧相连,第二蓄热装置、前级回热器的第二侧相连。本发明提供的错级回热式压缩空气储能系统,通过采用错级回热的方式,使储热介质的温度能够错位级间利用,避免级间多级回热减少空气压降,可以提高热源的利用效率,提高整个储能系统的能效。(The invention provides a staggered regenerative compressed air energy storage system, which comprises: the system comprises a preceding stage compressor, a heat absorber, a rear stage compressor, a gas storage device, a first heat storage device, a second heat storage device, a preceding stage heat regenerator, a rear stage heat regenerator, a preceding stage expander and a rear stage expander; wherein the outlet of the fore compressor, the first side of the heat absorber, the rear compressor, the gas storage device, the first side of the fore heat regenerator, the fore expander, the first side of the rear heat regenerator and the inlet of the rear expander are sequentially connected; and the second side of the heat absorber, the first heat storage device and the second side of the back-stage heat regenerator are connected, and the second heat storage device and the second side of the front-stage heat regenerator are connected. According to the staggered-stage regenerative compressed air energy storage system provided by the invention, the temperature of the heat storage medium can be utilized in staggered stages by adopting a staggered-stage regenerative mode, the interstage multistage regenerative is avoided, the air pressure drop is reduced, the utilization efficiency of a heat source can be improved, and the energy efficiency of the whole energy storage system is improved.)

1. A staggered regenerative compressed air energy storage system is characterized by comprising: the system comprises a preceding stage compressor, a heat absorber, a rear stage compressor, a gas storage device, a first heat storage device, a second heat storage device, a preceding stage heat regenerator, a rear stage heat regenerator, a preceding stage expander and a rear stage expander; wherein

The outlet of the fore compressor, the first side of the heat absorber, the rear compressor, the gas storage device, the first side of the fore heat regenerator, the fore expander, the first side of the rear heat regenerator and the inlet of the rear expander are sequentially connected;

the second side of the heat absorber, the first heat storage device and the second side of the back-stage heat regenerator are connected, and the second heat storage device and the second side of the front-stage heat regenerator are connected.

2. The cascade regenerative compressed air energy storage system according to claim 1, wherein the pre-stage compressor and the heat absorber are both multiple, the first sides of the pre-stage compressor and the heat absorber are staggered one by one and connected in sequence, and the second side of each heat absorber is connected to the first heat storage device.

3. The cascade regenerative compressed air energy storage system according to claim 2 wherein the second sides of the plurality of heat sinks are connected in parallel to the first thermal storage device.

4. The cascade regenerative compressed air energy storage system according to claim 3, wherein the outlet of the second side of each heat sink is connected to the high temperature inlet of the first thermal storage device, and the inlet of the second side of each heat sink is connected to the low temperature outlet of the first thermal storage device.

5. The tandem regenerative compressed air energy storage system according to claim 1, wherein the forward compressor comprises a forward first compressor and a forward second compressor, and the heat sink comprises a first heat sink and a second heat sink;

the outlet of the first compressor of the front stage is connected with the inlet of the second compressor of the front stage through the first side of the first heat absorber, and the outlet of the second compressor of the front stage is connected with the inlet of the compressor of the rear stage through the first side of the second heat absorber;

and the second side of the first heat absorber and the second side of the second heat absorber are both connected with the first heat storage device.

6. The regenerative compressed air energy storage system according to claim 5 wherein the second side of the first heat sink and the second side of the second heat sink are connected in parallel to the first thermal storage device.

7. The regenerative, staggered compressed air energy storage system according to any of claims 1 to 6 wherein the first thermal storage device comprises:

the high-temperature heat accumulator comprises a first high-temperature heat accumulator and a first low-temperature heat accumulator, wherein a high-temperature inlet of the first high-temperature heat accumulator is connected with an outlet on the second side of the heat absorber, a high-temperature outlet of the first high-temperature heat accumulator is connected with a low-temperature inlet of the first low-temperature heat accumulator through the second side of the back-stage heat regenerator, and a low-temperature outlet of the first low-temperature heat accumulator is connected with an inlet on the second side of the heat absorber.

8. The regenerative compressed air energy storage system of any of claims 1 to 6,

the number of the rear-stage heat regenerator is one;

or the number of the rear-stage heat regenerators and the number of the rear-stage expanders are multiple, the second sides of the rear-stage heat regenerators are sequentially connected in series, and the first sides of the rear-stage heat regenerators are staggered one by one and connected sequentially.

9. The regenerative compressed air energy storage system of any of claims 1 to 6, wherein the second thermal storage device comprises:

the high-temperature heat accumulator comprises a second high-temperature heat accumulator and a second low-temperature heat accumulator, a heating device is connected between a high-temperature inlet of the second high-temperature heat accumulator and a low-temperature outlet of the second low-temperature heat accumulator, and a high-temperature outlet of the second high-temperature heat accumulator is connected with a low-temperature inlet of the second low-temperature heat accumulator through a second side of the preceding-stage heat regenerator.

10. The cascade regenerative compressed air energy storage system according to any one of claims 1 to 6, wherein the first heat storage device and the second heat storage device are both molten salt heat storage devices, and the heat storage temperature of the second heat storage device is higher than the heat storage temperature of the first heat storage device.

Technical Field

The invention relates to the technical field of energy storage, in particular to a staggered regenerative compressed air energy storage system.

Background

At present, clean energy power generation sources in China are rapidly developed, and novel clean renewable energy represented by hydropower, photovoltaic and wind power becomes the primary choice for building clean energy power stations in China. Due to the influence of complex power supply structures, power grid structures, power price composition, historical factors and the like, outstanding contradictions such as power resource configuration distortion and the like are caused, the problems are limited by conventional power supply characteristics and power grid structures, and new energy consumption is obvious. The large-scale power energy storage technology can effectively solve the problem of instability of renewable energy sources, adjust the peak valley of a power grid and improve the economy and stability of a power system. In the existing large-scale power energy storage technology, compressed air energy storage is widely applied due to the advantages of large capacity, good economy, environmental friendliness, low running cost and the like.

Disclosure of Invention

The embodiment of the invention provides a staggered regenerative compressed air energy storage system, which is used for solving the defect of low efficiency of the energy storage system in the prior art.

The staggered-stage regenerative compressed air energy storage system provided by the embodiment of the invention comprises: the system comprises a preceding stage compressor, a heat absorber, a rear stage compressor, a gas storage device, a first heat storage device, a second heat storage device, a preceding stage heat regenerator, a rear stage heat regenerator, a preceding stage expander and a rear stage expander; wherein the outlet of the pre-stage compressor, the first side of the heat absorber, the post-stage compressor, the gas storage device, the first side of the pre-stage heat regenerator, the pre-stage expander, the first side of the post-stage heat regenerator, and the inlet of the post-stage expander are connected in sequence; the second side of the heat absorber, the first heat storage device and the second side of the back-stage heat regenerator are connected, and the second heat storage device and the second side of the front-stage heat regenerator are connected.

In some embodiments, the preceding stage compressor and the heat absorber are both multiple, and multiple preceding stage compressors and multiple first sides of the heat absorber are staggered one by one and connected in sequence, and each second side of the heat absorber is connected with the first heat storage device.

In some embodiments, a second side of a plurality of the heat sinks are connected in parallel to the first thermal storage device.

In some embodiments, the outlet of the second side of each heat sink is connected to a high temperature inlet of the first thermal storage device and the inlet of the second side of each heat sink is connected to a low temperature outlet of the first thermal storage device.

In some embodiments, the backing compressor comprises a backing first compressor and a backing second compressor, and the heat sink comprises a first heat sink and a second heat sink; the outlet of the first compressor of the front stage is connected with the inlet of the second compressor of the front stage through the first side of the first heat absorber, and the outlet of the second compressor of the front stage is connected with the inlet of the compressor of the rear stage through the first side of the second heat absorber; and the second side of the first heat absorber and the second side of the second heat absorber are both connected with the first heat storage device.

In some embodiments, a second side of the first heat sink and a second side of the second heat sink are connected in parallel to the first thermal storage device.

In some embodiments, the first thermal storage device includes: the high-temperature heat accumulator comprises a first high-temperature heat accumulator and a first low-temperature heat accumulator, wherein a high-temperature inlet of the first high-temperature heat accumulator is connected with an outlet on the second side of the heat absorber, a high-temperature outlet of the first high-temperature heat accumulator is connected with a low-temperature inlet of the first low-temperature heat accumulator through the second side of the back-stage heat regenerator, and a low-temperature outlet of the first low-temperature heat accumulator is connected with an inlet on the second side of the heat absorber.

In some embodiments, the rear stage regenerator is one; or the number of the rear-stage heat regenerators and the number of the rear-stage expanders are multiple, the second sides of the rear-stage heat regenerators are sequentially connected in series, and the first sides of the rear-stage heat regenerators are staggered one by one and connected sequentially.

In some embodiments, the second thermal storage device includes: the high-temperature heat accumulator comprises a second high-temperature heat accumulator and a second low-temperature heat accumulator, a heating device is connected between a high-temperature inlet of the second high-temperature heat accumulator and a low-temperature outlet of the second low-temperature heat accumulator, and a high-temperature outlet of the second high-temperature heat accumulator is connected with a low-temperature inlet of the second low-temperature heat accumulator through a second side of the preceding-stage heat regenerator.

In some embodiments, the first heat storage device and the second heat storage device are both molten salt heat storage devices, and the heat storage temperature of the second heat storage device is higher than the heat storage temperature of the first heat storage device.

According to the staggered-stage regenerative compressed air energy storage system provided by the embodiment of the invention, the temperature of the heat storage medium can be utilized in staggered stages by adopting a staggered-stage regenerative mode, so that the interstage multistage regenerative is avoided, the air pressure drop is reduced, the utilization efficiency of a heat source can be improved, and the energy efficiency of the whole energy storage system is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and those skilled in the art can also obtain other drawings according to the drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a stepped regenerative compressed air energy storage system according to an embodiment of the present invention.

Reference numerals:

1-a preceding stage first compressor; 2-a preceding stage second compressor; 3-a rear stage compressor; 4-a first heat absorber; 5-a second heat sink; 6-a first high temperature regenerator; 7-a first low temperature regenerator; 8-a second high temperature regenerator; 9-a second low temperature regenerator; 10-gas storage means; 11-a pre-stage heat regenerator; 12-a back-stage regenerator; 13-a pre-expander; 14-a rear stage expander; 15-a heating device; A/B-motor.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A staggered regenerative compressed air energy storage system according to an embodiment of the present invention is described below with reference to fig. 1.

As shown in fig. 1, the regenerative compressed air energy storage system with staggered stages according to the embodiment of the present invention includes: the system comprises a front-stage compressor, a heat absorber, a rear-stage compressor 3, a gas storage device 10, a first heat storage device, a second heat storage device, a front-stage heat regenerator 11, a rear-stage heat regenerator 12, a front-stage expansion machine 13 and a rear-stage expansion machine 14.

The front-stage compressor and the rear-stage compressor 3 may be air compressors, the front-stage compressor and the rear-stage compressor 3 are used for compressing air, the air is pressurized and heated during the compression process, the front-stage compressor and the rear-stage compressor 3 may be connected with motors, for example, the front-stage compressor in fig. 1 is driven by a motor a, and the rear-stage compressor 3 is driven by a motor B.

The front-stage expander 13 and the rear-stage expander 14 can utilize the compressed gas to expand and reduce the pressure to output mechanical work outwards and reduce the temperature of the gas, the front-stage expander 13 and the rear-stage expander 14 are used for converting the stored heat energy and the internal energy of the compressed air into mechanical energy to output, for example, the front-stage expander 13 and the rear-stage expander 14 can be connected with a generator to drive the generator to generate electricity.

The heat absorber, the pre-stage regenerator 11 and the post-stage regenerator 12 are all heat exchangers, and the heat absorber, the pre-stage regenerator 11 and the post-stage regenerator 12 may respectively include a first side and a second side (a hot side and a cold side), and flow paths of the first side and the second side are respectively used for circulating corresponding media, so that the two media exchange heat when flowing through the heat exchanger. The inlet and outlet of the first side of the heat exchanger and the inlet and outlet of the second side of the heat exchanger can be arranged in a reverse direction, so that media on the first side and the second side can flow in a reverse direction to enhance the heat exchange efficiency.

As shown in fig. 1, the outlet of the pre-stage compressor, the first side of the heat absorber, the post-stage compressor 3, the gas storage device 10, the first side of the pre-stage heat regenerator 11, the pre-stage expander 13, the first side of the post-stage heat regenerator 12, and the inlet of the post-stage expander 14 are connected in sequence.

In other words, the outlet of the preceding stage compressor is connected to the inlet of the following stage compressor 3 through the first side of the heat absorber, the outlet of the following stage compressor 3 is connected to the inlet of the gas storage device 10, the outlet of the gas storage device 10 is connected to the inlet of the preceding stage expander 13 through the first side of the preceding stage heat regenerator 11, and the outlet of the preceding stage expander 13 is connected to the inlet of the following stage expander 14 through the first side of the following stage heat regenerator 12.

The inlet of the pre-stage compressor is used for sucking air, for example, an air filter may be connected to the inlet of the pre-stage compressor, and the filtered clean air is sucked through the air filter. The outlet of the preceding stage compressor is connected to the inlet of the first side of the heat absorber, and the outlet of the first side of the heat absorber is connected to the inlet of the following stage compressor 3.

The gas storage device 10 is used for storing high-temperature and high-pressure gas, for example, the gas storage device 10 may include a pipeline steel gas storage. The gas storage device 10 may maintain heat energy of the gas stored therein through a heat-insulating process.

An outlet of the gas storage device 10 is connected to an inlet of a first side of the pre-stage regenerator 11, an outlet of the first side of the pre-stage regenerator 11 is connected to an inlet of the pre-stage expander 13, an outlet of the pre-stage expander 13 is connected to an inlet of a first side of the post-stage regenerator 12, an outlet of the first side of the post-stage regenerator 12 is connected to an inlet of the post-stage expander 14, an outlet of the post-stage expander 14 may discharge exhaust gas or an outlet of the post-stage expander 14 may be connected to an adsorption device for filtering air and then discharging clean air to the outside.

As shown in fig. 1, the second side of the heat sink, the first thermal storage device, and the second side of the back-stage regenerator 12 are connected.

The outlet of the second side of the heat absorber is connected with the high-temperature inlet of the first heat storage device, the high-temperature outlet of the first heat storage device is connected with the low-temperature inlet of the first heat storage device through the second side of the back-stage heat regenerator 12, and the low-temperature outlet of the first heat storage device is connected with the inlet of the second side of the heat absorber.

An energy storage stage:

the high-temperature high-pressure gas discharged by the preceding stage compressor enters the first side of the heat absorber and exchanges heat with the heat storage medium on the second side of the heat absorber, that is, the first heat storage device can store the compression heat of the preceding stage compressor, the first heat storage device can be a molten salt heat storage device, correspondingly, the heat storage medium between the second side of the heat absorber, the first heat storage device and the second side of the back stage heat regenerator 12 is molten salt, and the heat storage medium can be driven to flow among the second side of the heat absorber, the first heat storage device and the second side of the back stage heat regenerator 12 by arranging a molten salt pump.

The rear stage compressor 3 sucks the high-pressure gas after heat exchange and then compresses the high-pressure gas again, and the high-temperature high-pressure gas discharged by the rear stage compressor 3 is directly stored in the gas storage device 10 without being subjected to heat recovery, so that the temperature of the gas in the gas storage device 10 is higher.

As shown in fig. 1, the second thermal storage device is connected to the second side of pre-regenerator 11.

The second heat storage device stores high-temperature heat storage media in advance for use during the staggered regenerative heating. For example, the heat storage medium may be heated by the heating device 15 and then stored in the second heat storage device, the first heat storage device and the second heat storage device are both molten salt heat storage devices, correspondingly, the heat storage medium between the second heat storage device and the second side of the pre-regenerator 11 is molten salt, and a molten salt pump may be arranged to drive the heat storage medium to flow between the second heat storage device and the second side of the pre-regenerator 11. The heating device 15 can be an external heat source, which can be determined according to the actual usage environment of the recuperated compressed air energy storage system, such as surplus steam near a power station, or an electric heater driven by electric energy at a low valley price. The heat storage temperature of the second heat storage device is higher than the heat storage temperature of the first heat storage device. This ensures that the gas temperature fed to the pre-expander 13 is higher and the efficiency of the pre-expander 13 is higher.

Energy release stage:

the high-temperature high-pressure gas in the gas storage device 10 flows into the first side of the pre-stage heat regenerator 11, the high-temperature heat storage medium in the second heat storage device flows into the second side of the pre-stage heat regenerator 11, and the high-temperature high-pressure gas in the gas storage device 10 is heated by the high-temperature heat storage medium of the second heat storage device in the pre-stage heat regenerator 11, so that the temperature of the gas storage device is greatly increased, the high-temperature high-pressure gas is expanded to the medium-pressure medium temperature through the pre-stage expander 13, and the pre-stage expander 13 is driven to move to realize.

The medium-temperature medium-pressure gas discharged from the front-stage expander 13 passes through the first side of the rear-stage regenerator 12, the high-temperature heat storage medium in the first heat storage device flows into the second side of the rear-stage regenerator 12, the medium-temperature medium-pressure gas discharged from the front-stage expander 13 is heated in the rear-stage regenerator 12, and after the temperature of the medium-temperature medium-pressure gas in the medium-pressure state is increased, the medium-temperature medium-pressure gas continues to expand and work through the rear-stage expander 14, so that energy release is realized again.

It can be understood that, in the energy storage stage, the high-temperature and high-pressure gas discharged by the rear-stage compressor 3 is directly stored in the gas storage device 10 without being subjected to heat recovery, so that the temperature of the gas in the gas storage device 10 is higher, in the energy release stage, the high-quality heat energy stored in the second heat storage device can be more efficiently utilized, and the high-quality heat energy stored in the second heat storage device is only used for heating the temperature of the gas at the inlet of the front-stage expander 13, so that the medium can be always maintained in a higher working temperature range, and the heat energy can be utilized in a high quality manner.

The high-quality heat energy stored by the second heat storage device further increases the temperature of the gas at the outlet of the gas storage device 10 to be higher than the highest temperature in the compression system, improves the system efficiency, reduces the energy level loss during wide-temperature heat exchange of a high-temperature medium, and keeps high-quality utilization of energy.

The outlet temperature of the preceding stage expander 13 can be increased by supplementing heat with the external heat source high-temperature medium of the second heat storage device, so that when the compression heat of the preceding stage compressor is used for performing the back-stage expansion heat regeneration, the working temperature range of the compression heat is also indirectly increased, the temperature of the medium-pressure inlet air is increased, and the heat energy is released in a reasonable temperature range.

According to the staggered-stage regenerative compressed air energy storage system disclosed by the embodiment of the invention, the temperature of the heat storage medium can be utilized in staggered stages by adopting a staggered-stage regenerative mode, so that the interstage multistage regenerative is avoided, the air pressure drop is reduced, the utilization efficiency of a heat source can be improved, and the energy efficiency of the whole energy storage system is improved.

In some embodiments, as shown in fig. 1, the pre-stage compressor and the heat absorber may be multiple, and the first sides of the multiple pre-stage compressors and the multiple heat absorbers are staggered one by one and connected in sequence, and the second side of each heat absorber is connected to the first thermal storage device. The pre-stage compressor and heat sink may be two or more.

In other words, the first pre-stage compressor, the first side of the first pre-stage compressor, the second pre-stage compressor, the first side … … of the second pre-stage heat sink, and the first side of the last heat sink may be serially connected in series, such that a progressive compression of the gas may be achieved.

The second side of each heat absorber is connected with the first heat storage device, namely, the compression heat of each preceding stage compressor can realize heat recovery.

In some embodiments, as shown in fig. 1, the second sides of the plurality of heat sinks are connected in parallel to the first thermal storage device. In a practical implementation, the outlet of the second side of each heat sink is connected to the high temperature inlet of the first thermal storage means and the inlet of the second side of each heat sink is connected to the low temperature outlet of the first thermal storage means. Therefore, the temperature difference of the media on the two sides of each heat absorber can be kept large enough, and the heat exchange efficiency can be improved.

Of course, in other embodiments, the second sides of the plurality of heat sinks may be connected in series to the first thermal storage device, or in series-parallel series to the first thermal storage device.

In some embodiments, as shown in fig. 1, the backing compressor comprises a backing first compressor 1 and a backing second compressor 2, and the heat sinks comprise a first heat sink 4 and a second heat sink 5; the outlet of the first compressor 1 of the front stage is connected with the inlet of the second compressor 2 of the front stage through the first side of the first heat absorber 4, and the outlet of the second compressor 2 of the front stage is connected with the inlet of the compressor 3 of the rear stage through the first side of the second heat absorber 5; the second side of the first heat sink 4 and the second side of the second heat sink 5 are both connected to the first thermal storage means. The second side of the first heat sink 4 and the second side of the second heat sink 5 are connected in parallel to the first thermal storage device. In practical implementations, the outlet of the second side of the first heat sink 4 and the outlet of the second side of the second heat sink 5 are both connected to the high temperature inlet of the first thermal storage device, and the inlet of the second side of the first heat sink 4 and the inlet of the second side of the second heat sink 5 are both connected to the low temperature outlet of the first thermal storage device. Therefore, the temperature difference of the media on the two sides of each heat absorber can be kept large enough, and the heat exchange efficiency can be improved.

Some structural forms of the first thermal storage device will be described below.

In some embodiments, the first thermal storage device may be of a single-tank type, and for the first thermal storage device of the single-tank type, a high-temperature inlet may be provided at an upper end of the first thermal storage device, a low-temperature outlet may be provided at a bottom of the first thermal storage device, a high-temperature outlet may be provided at an upper end of the first thermal storage device, and a low-temperature inlet may be provided at a bottom of the first thermal storage device.

In other embodiments, as shown in fig. 1, the first thermal storage device includes: the heat absorber comprises a first high-temperature heat accumulator 6 and a first low-temperature heat accumulator 7, wherein a high-temperature inlet of the first high-temperature heat accumulator 6 is connected with an outlet on the second side of the heat absorber, a high-temperature outlet of the first high-temperature heat accumulator 6 is connected with a low-temperature inlet of the first low-temperature heat accumulator 7 through the second side of a back-stage heat regenerator 12, and a low-temperature outlet of the first low-temperature heat accumulator 7 is connected with an inlet on the second side of the heat absorber.

The first heat storage device adopts the structure that the high temperature and the low temperature are separately arranged, so that the high-temperature medium can be effectively prevented from being mixed, and the heat exchange efficiency in the energy storage stage and the energy release stage is improved.

In some embodiments, as shown in fig. 1, there is one after-stage regenerator 12. The inlet of the second side of the back-stage regenerator 12 is connected to the high-temperature outlet of the first thermal storage device, and the outlet of the second side of the back-stage regenerator 12 is connected to the low-temperature inlet of the first thermal storage device.

As shown in fig. 1, the first thermal storage device includes: in the embodiment of the first high-temperature regenerator 6 and the first low-temperature regenerator 7, the inlet of the second side of the back-stage regenerator 12 is connected to the high-temperature outlet of the first high-temperature regenerator 6, and the outlet of the second side of the back-stage regenerator 12 is connected to the low-temperature inlet of the first low-temperature regenerator 7.

In other embodiments, the number of the rear-stage regenerators 12 and the number of the rear-stage expanders 14 are multiple (two or more), the second sides of the multiple rear-stage regenerators 12 are sequentially connected in series, and the first sides of the multiple rear-stage regenerators 14 and the multiple rear-stage regenerators 12 are staggered one by one and sequentially connected.

Taking two post-stage regenerators 12 and two post-stage expanders 14 as an example, the inlet of the second side of the first post-stage regenerator 12 is connected to the high-temperature outlet of the first high-temperature regenerator 6, the outlet of the second side of the first post-stage regenerator 12 is connected to the inlet of the second side of the second post-stage regenerator 12, and the outlet of the second side of the second post-stage regenerator 12 is connected to the low-temperature inlet of the first low-temperature regenerator 7. The inlet of the first side of the first subsequent regenerator 12 is connected to the outlet of the preceding expander 13, the outlet of the first side of the first subsequent regenerator 12 is connected to the inlet of the first subsequent expander 14, the outlet of the first subsequent expander 14 is connected to the inlet of the first side of the second subsequent regenerator 12, and the outlet of the first side of the second subsequent regenerator 12 is connected to the inlet of the second subsequent expander 14.

For embodiments in which the rear-stage regenerator 12 and the rear-stage expander 14 are plural, the configuration can be made with reference to the above-described embodiments.

Some structural forms of the first thermal storage device will be described below.

In some embodiments, the second thermal storage device may be of a single-tank type, and its structural form may be designed with reference to the first thermal storage device.

In other embodiments, as shown in fig. 1, the second thermal storage device includes: the high-temperature heat accumulator comprises a second high-temperature heat accumulator 8 and a second low-temperature heat accumulator 9, a heating device 15 is connected between a high-temperature inlet of the second high-temperature heat accumulator 8 and a low-temperature outlet of the second low-temperature heat accumulator 9, and a high-temperature outlet of the second high-temperature heat accumulator 8 is connected with a low-temperature inlet of the second low-temperature heat accumulator 9 through a second side of a preceding-stage heat regenerator 11.

It should be noted that the first heat storage device and the second heat storage device of the above-described embodiment may be molten salt heat storage devices, but the first heat storage device and the second heat storage device may also be other types of heat storage devices, such as a structural form of an inclined temperature layer heat storage water tank.

A specific embodiment is described below.

As shown in fig. 1, the regenerative compressed air energy storage system of the embodiment includes: the system comprises a first preceding stage compressor 1, a second preceding stage compressor 2, a rear stage compressor 3, a first heat absorber 4, a second heat absorber 5, a first high-temperature heat accumulator 6, a first low-temperature heat accumulator 7, a second high-temperature heat accumulator 8, a second low-temperature heat accumulator 9, a gas storage device 10, a preceding stage heat regenerator 11, a rear stage heat regenerator 12, a preceding stage expander 13 and a rear stage expander 14.

The method comprises the following steps: in the energy storage stage, the first heat absorber 4 and the second heat absorber 5 absorb the compression heat of the first preceding compressor 1 and the second preceding compressor 2, respectively, and store the compression heat in the first high-temperature heat accumulator 6.

If the first compressor 1 at the front stage sucks air from the atmosphere, the ambient pressure is 0.1Mpa, the ambient temperature is-10 to 30 ℃, the exhaust pressure is 0.79 to 0.8Mpa, and the exhaust temperature is 245 to 319 ℃. The front stage second compressor 2 has an air inlet range of 0.75-0.76 Mpa, an air inlet temperature range of 39-41 ℃, an exhaust pressure range of 4.61-4.62 Mpa and an exhaust range of 286-319 ℃. The heat storage medium in the first low-temperature heat accumulator 7 is heated to 290 ℃ or higher by the first heat absorber 4 and the second heat absorber 5 and stored in the first high-temperature heat accumulator 6.

Step two: the high-temperature and high-pressure air compressed by the rear-stage compressor 3 is directly introduced into the air storage device 10, and the air storage device 10 is subjected to heat preservation treatment.

For example, the inlet air temperature of the rear stage compressor 3 is 39-41 ℃. The exhaust pressure is 10.2Mpa, and the exhaust temperature is 120 ℃.

Step three: the heat storage medium (taking molten salt as an example) in the second low-temperature heat accumulator 9 is heated by an external heat source or electric energy at a low valley price and stored in the second high-temperature heat accumulator 8 for use in the staggered heat regeneration. Such as molten salt, is heated to 565 c and stored in the second high temperature regenerator 8.

Step four: in the energy release stage, the high-temperature air with the outlet temperature of 120 ℃ from the gas storage device 10 is further heated to 400 ℃ through the pre-heat regenerator 11 by the molten salt in the second high-temperature heat accumulator 8, so that the temperature of the air is greatly increased. The air is expanded to steam with pressure of 0.68-0.69 MPa, temperature of 114 ℃ and medium temperature through a preceding stage expander 13.

Step five: the medium-temperature medium-pressure air from the outlet of the front-stage expander 13 is further heated to 240 ℃ by the rear-stage regenerator 12, and after the temperature of the medium-temperature medium-pressure air is increased, the medium-temperature medium-pressure air continues to expand and work by the rear-stage expander 14.

It should be noted that, through a great deal of research, the main parameters influencing the output electric energy of the turboexpander in the non-afterburning compressed air energy storage system include: intake pressure and temperature. The energy storage efficiency of the energy storage coefficient is increased along with the increase of the air inlet temperature and the pressure parameter, and the sensitivity of the system energy storage efficiency to the temperature is higher than that of the system energy storage efficiency to the pressure. Therefore, the energy storage coefficient of the system can be greatly improved by increasing the temperature of the air.

According to the staggered regenerative compressed air energy storage system provided by the embodiment of the invention, the high-quality heat source is used for heating the inlet air temperature of the pre-stage expander 13 (the first stage) by converting the low-valley electricity price, the abandoned wind, the abandoned photoelectric electric energy or the external energy sources such as the photo-thermal energy into the high-quality heat energy for storage (taking the fused salt energy storage as an example) and taking the high-quality heat energy as a heat supplementing heat source in a staggered regenerative mode, so that the high-pressure air problem is greatly improved to be higher than the highest outlet temperature in the compression link, the air acting capacity is improved, the heat utilization temperature interval of the high-quality heat source is also improved, and the energy quality is prevented from being greatly reduced. The inlet temperature of the rear stage expander 14 is heated by a quality heat source in the compression heat recovered in the compression process, and the air temperature at the corresponding secondary expansion pressure is raised.

In other words, the high-temperature molten salt medium obtained by high-quality electric energy (or other external heat sources) is only used for heating the air temperature at the front-stage expansion inlet by adopting a staggered-stage heat regeneration mode, so that the medium can be always maintained in a higher working temperature range, and the heat energy can be utilized in high quality. The temperature of the air at the outlet of the air storage device 10 can be further increased to be higher than the highest temperature in a compression system, the system efficiency is improved, the energy level loss during wide-temperature heat exchange of a high-temperature medium is reduced, and high-quality utilization of energy is kept. The outlet temperature of the front stage expander 13 can be raised by the heat compensation of the high temperature medium of the external heat source, so that the working temperature range of the compression heat is indirectly raised when the compression heat of the front stage compressor is used for carrying out the back-heating of the back stage expansion. The temperature of the medium-pressure inlet air is improved, and the heat energy is released in a reasonable temperature range.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.