阅读说明：本技术 一种可提高电-电转换效率的压缩空气储能系统及方法 (Compressed air energy storage system and method capable of improving electricity-electricity conversion efficiency ) 是由 蒋庆康 黄博南 肖军 刘鑫蕊 孙秋野 杨珺 李明 高凯 于 2019-09-19 设计创作，主要内容包括：本发明的可提高电-电转换效率的压缩空气储能系统及方法,系统结合了补燃型和非补燃型两种发电模式,弥补了由储气罐气压下限约束较高所造成的系统充电效率降低的缺陷；系统在发电工况下,当储气罐内气压值处于较高位时,由非补燃发电组件进行发电,储气罐排出的高压气体节流后,用低品质热源与高压气体进行换热,可提高单位工质的做功能力；当空气透平长时间处于较高发电负荷运行时,储气罐内的气压值下降速率加快,改用高品质热源与高压气体进行换热,以节省储气罐在气压值处于高位时的用气；当储气罐内气压值较低时,由补燃发电组件进行发电,以增加储气罐的用气深度,保证系统在一个调度周期内只进行一次充放电循环,提高系统电-电转换效率。(According to the compressed air energy storage system and the method capable of improving the electricity-electricity conversion efficiency, the system combines two power generation modes of a complementary combustion type and a non-complementary combustion type, and the defect that the charging efficiency of the system is reduced due to the fact that the lower limit of the air pressure of the air storage tank is high is overcome; under the power generation working condition of the system, when the air pressure value in the air storage tank is at a higher position, the non-afterburning power generation assembly generates power, and high-pressure gas exhausted by the air storage tank is throttled and then exchanges heat with the high-pressure gas by using a low-quality heat source, so that the working capacity of a unit working medium can be improved; when the air turbine is operated at a high power generation load for a long time, the reduction rate of the air pressure value in the air storage tank is increased, and a high-quality heat source is used for exchanging heat with high-pressure air so as to save the air used by the air storage tank when the air pressure value is at a high level; when the air pressure value in the air storage tank is low, the afterburning power generation assembly generates power to increase the air consumption depth of the air storage tank, ensure that the system only carries out one-time charge and discharge cycle in a scheduling period, and improve the electricity-electricity conversion efficiency of the system.)

1. The utility model provides a can improve electricity-electricity conversion efficiency's compressed air energy storage system which characterized in that: the device comprises a motor, a compressor unit, a gas storage tank, a three-way valve, a non-afterburning power generation assembly and an afterburning power generation assembly; the non-afterburning power generation assembly comprises a first gas-liquid heat exchanger, a second gas-liquid heat exchanger, an air turbine and a first power generator; the afterburning power generation assembly comprises a heat regenerator, a natural gas storage tank, a combustion chamber, a gas turbine and a second power generator; a motor shaft of the motor is fixedly connected with a power input shaft of the compressor unit, an air outlet of the compressor unit is communicated with an air inlet of the air storage tank through a first quick-closing valve, and an air outlet of the air storage tank is communicated with an air inlet of the three-way valve through a second quick-closing valve; the first air outlet of the three-way valve is output in two paths, the first path is communicated with the air inlet of the first gas-liquid heat exchanger through a first electric regulating valve, the second path is communicated with the air inlet of the second gas-liquid heat exchanger through a second electric regulating valve, the air outlets of the first gas-liquid heat exchanger and the second gas-liquid heat exchanger are connected into one path in a gathering mode and communicated with the air inlet of the air turbine through a third quick-closing valve, the air outlet of the air turbine is communicated with the atmosphere, and the power output shaft of the air turbine is fixedly connected with the motor shaft of the first generator; a heat source introduced into a liquid inlet of the first gas-liquid heat exchanger is a medium heat source, and the temperature of the heat source is more than or equal to 500 ℃; a heat source introduced into a liquid inlet of the second gas-liquid heat exchanger is a low-quality heat source, and the temperature of the heat source is more than or equal to 200 ℃; a second air outlet of the three-way valve is communicated with a cold end air inlet of the heat regenerator through a third electric regulating valve, a cold end air outlet of the heat regenerator is communicated with an air inlet of the combustion chamber, a gas outlet of the natural gas storage tank is communicated with a gas inlet of the combustion chamber through a fourth electric regulating valve, a flue gas outlet of the combustion chamber is communicated with an air inlet of a gas turbine through a fourth quick closing valve, an air outlet of the gas turbine is communicated with a hot end air inlet of the heat regenerator, and a hot end air outlet of the heat regenerator is communicated with the atmosphere; and a power output shaft of the gas turbine is fixedly connected with a motor shaft of the second generator.

2. A compressed air energy storage method capable of improving the electricity-electricity conversion efficiency, which adopts the compressed air energy storage system capable of improving the electricity-electricity conversion efficiency of claim 1, and is characterized by comprising the following steps:

the method comprises the following steps: measuring the air pressure in the air tank, and recording the measured air pressure as P_cq.t；

Step two: judging whether the system receives a charging/generating command; if a charging command is received, turning to the third step; if a power generation command is received, turning to the fourth step; if no command is received, keeping the first quick closing valve and the second quick closing valve in a closed state;

step three: confirming that the second quick closing valve is closed, and judging whether the air pressure in the air storage tank meets P_cq.t<P_cq.maxIn which P is_cq.maxIs the upper limit of the air pressure value in the air storage tank; when a plurality of conditions are met, the first quick closing valve is opened, the motor is started, the compressor unit is used for inflating the air storage tank, and the step one is carried out; if the condition is not met, turning to the step eight;

step four: confirming that the first quick closing valve is closed, and judging whether the air pressure in the air storage tank meets the lower limit constraint, namely P_cq.t>γδP_eWherein P is_eIs the air pressure of the surrounding environment of the system, gamma is the air depth correction coefficient and satisfies 0.5<γ<1, delta is an ambient air pressure multiple determined according to the rated load power of the air turbine; if it satisfiesLimiting the lower limit, opening a second quick closing valve, and turning to the fifth step; if the lower limit constraint is not met, turning to the step eight;

step five: if P is satisfied_cq.t>δP_eOpening a first air outlet of the three-way valve, and turning to the step six; if gamma delta P is satisfied_e<P_cq.t<γP_eOpening a second air outlet of the three-way valve, and turning to the seventh step;

step six: judging whether the air turbine is in a high power generation load operation state for a long time whenWhen the first electric regulating valve is turned off, the high-pressure gas is subjected to pressure reduction through the second electric regulating valve, then enters the second gas-liquid heat exchanger to perform heat exchange with the low-quality heat source, the high-pressure gas after heat exchange directly enters the air turbine to drive the first generator to generate electricity, and then the step I is carried out; when in use

step seven: opening a third electric regulating valve, throttling high-pressure air through the third electric regulating valve, then, enabling the high-pressure air to enter a heat regenerator to exchange heat with secondarily utilized high-temperature flue gas, enabling the heat-exchanged high-pressure air to enter a combustion chamber, simultaneously introducing natural gas into the combustion chamber through a natural gas storage tank, enabling the natural gas and the high-pressure air to be mixed and combusted in the combustion chamber, enabling the formed high-temperature flue gas to directly enter a gas turbine to drive a second generator to generate electricity, adjusting the air outlet flow of the natural gas storage tank through a fourth electric regulating valve along with the change of the required electricity generation load, and then, turning to the step one;

step eight: and confirming that the first quick closing valve and the second quick closing valve are in a closed state, and stopping generating power by the system.

Technical Field

The invention belongs to the technical field of compressed air energy storage, and particularly relates to a compressed air energy storage system and method capable of improving electricity-electricity conversion efficiency.

Background

The Compressed Air Energy Storage (CAES) technology is characterized in that during the electricity consumption valley, the excess generated energy of new energy such as wind energy, solar energy and the like is stored through compressed air, compressed high-pressure air is stored in a specific air storage tank, and when the electricity consumption peak stage is reached, the high-pressure air in the air storage tank is released to push an air turbine to drive a generator to generate electricity, so that the purpose of electric energy storage is finally achieved.

Because of the constraint of the rated power generation power of the air turbine, the lower limit value of the air pressure of the air storage tank needs to be set higher to meet the power generation requirement of the load, so that when the compressed air energy storage system releases energy, if the power generation power is in a high position for a long time, for a small and medium-sized air storage tank, the residual power generation amount of the small and medium-sized air storage tank also drops sharply along with the rapid reduction of the air pressure value, and therefore, multiple times of charging are necessary in one scheduling period to supplement the air storage amount; in addition, the air exhausted by the air storage tank is heated to improve the generating capacity of unit working media and reduce the air consumption of the compressed air energy storage system when the generating power is high for a long time, the compressed air energy storage system which can be used for achieving the purpose at present can be divided into two types, namely an adiabatic type and a non-adiabatic type, the adiabatic type stores the compression heat, the air exhausted by the air storage tank is heated when the system releases the energy, because the external auxiliary heat energy is not needed, the compressed air energy storage system has high energy conversion efficiency, but the working capacity of the heated unit working media is low; the non-adiabatic type is divided into a post-combustion type and a non-post-combustion type, the post-combustion type generates high-temperature flue gas by additionally consuming fuel to push a gas turbine to generate electricity, the non-post-combustion type exchanges heat with air exhausted from an air storage tank by means of an external heat source, and the post-combustion type has more advantages in unit working medium working capacity.

However, in the charging process of the compressed air energy storage system, along with the increase of the air pressure of the air storage tank, the energy loss generated in the compressor unit and the transmission pipeline is gradually increased, so that the efficiency of the system in a plurality of charging processes in a scheduling period is reduced, and the electricity-electricity conversion efficiency of the whole compressed air energy storage system is reduced.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a compressed air energy storage system and a method capable of improving the electricity-electricity conversion efficiency, wherein a post-combustion type power generation mode and a non-post-combustion type power generation mode are combined for the first time, so that the defect of reduction of the system charging efficiency caused by higher air pressure lower limit constraint of an air storage tank is effectively overcome, and the electricity-electricity conversion efficiency of the system is effectively improved.

In order to achieve the purpose, the invention adopts the following technical scheme: a compressed air energy storage system capable of improving electricity-electricity conversion efficiency comprises a motor, a compressor set, an air storage tank, a three-way valve, a non-afterburning power generation assembly and an afterburning power generation assembly; the non-afterburning power generation assembly comprises a first gas-liquid heat exchanger, a second gas-liquid heat exchanger, an air turbine and a first power generator; the afterburning power generation assembly comprises a heat regenerator, a natural gas storage tank, a combustion chamber, a gas turbine and a second power generator; a motor shaft of the motor is fixedly connected with a power input shaft of the compressor unit, an air outlet of the compressor unit is communicated with an air inlet of the air storage tank through a first quick-closing valve, and an air outlet of the air storage tank is communicated with an air inlet of the three-way valve through a second quick-closing valve; the first air outlet of the three-way valve is output in two paths, the first path is communicated with the air inlet of the first gas-liquid heat exchanger through a first electric regulating valve, the second path is communicated with the air inlet of the second gas-liquid heat exchanger through a second electric regulating valve, the air outlets of the first gas-liquid heat exchanger and the second gas-liquid heat exchanger are connected into one path in a gathering mode and communicated with the air inlet of the air turbine through a third quick-closing valve, the air outlet of the air turbine is communicated with the atmosphere, and the power output shaft of the air turbine is fixedly connected with the motor shaft of the first generator; a heat source introduced into a liquid inlet of the first gas-liquid heat exchanger is a medium heat source, and the temperature of the heat source is more than or equal to 500 ℃; a heat source introduced into a liquid inlet of the second gas-liquid heat exchanger is a low-quality heat source, and the temperature of the heat source is more than or equal to 200 ℃; a second air outlet of the three-way valve is communicated with a cold end air inlet of the heat regenerator through a third electric regulating valve, a cold end air outlet of the heat regenerator is communicated with an air inlet of the combustion chamber, a gas outlet of the natural gas storage tank is communicated with a gas inlet of the combustion chamber through a fourth electric regulating valve, a flue gas outlet of the combustion chamber is communicated with an air inlet of a gas turbine through a fourth quick closing valve, an air outlet of the gas turbine is communicated with a hot end air inlet of the heat regenerator, and a hot end air outlet of the heat regenerator is communicated with the atmosphere; and a power output shaft of the gas turbine is fixedly connected with a motor shaft of the second generator.

A compressed air energy storage method capable of improving the electricity-electricity conversion efficiency adopts the compressed air energy storage system capable of improving the electricity-electricity conversion efficiency, and comprises the following steps:

the method comprises the following steps: measuring the air pressure in the air tank, and recording the measured air pressure as P_cq.t；

Step two: judging whether the system receives a charging/generating command; if a charging command is received, turning to the third step; if a power generation command is received, turning to the fourth step; if no command is received, keeping the first quick closing valve and the second quick closing valve in a closed state;

step three: confirming that the second quick closing valve is closed, and judging whether the air pressure in the air storage tank meets P_cq.t<P_cq.maxIn which P is_cq.maxIs the upper limit of the air pressure value in the air storage tank; when a plurality of conditions are met, the first quick closing valve is opened, the motor is started, the compressor unit is used for inflating the air storage tank, and the step one is carried out; if the condition is not met, turning to the step eight;

step four: confirming that the first quick closing valve is closed, and judging whether the air pressure in the air storage tank meets the lower limit constraint, namely P_cq.t>γδP_eWherein P is_eIs the air pressure of the surrounding environment of the system, gamma is the air depth correction coefficient and satisfies 0.5<γ<1, delta is an ambient air pressure multiple determined according to the rated load power of the air turbine; if the lower limit constraint is met, opening the second quick closing valve, and turning to the fifth step; if the lower limit constraint is not met, turning to the step eight;

step five: if P is satisfied_cq.t>δP_eOpening a first air outlet of the three-way valve, and turning to the step six; if gamma delta P is satisfied_e<P_cq.t<γP_eOpening a second air outlet of the three-way valve, and turning to the seventh step;

step six: judging whether the air turbine is in a high power generation load operation state for a long time when

When the first electric regulating valve is turned off, the high-pressure gas is subjected to pressure reduction through the second electric regulating valve, then enters the second gas-liquid heat exchanger to perform heat exchange with the low-quality heat source, the high-pressure gas after heat exchange directly enters the air turbine to drive the first generator to generate electricity, and then the step I is carried out; when in use

When the gas-liquid heat exchanger is used, the second electric regulating valve is turned off, the high-pressure gas is reduced in pressure through the first electric regulating valve and then enters the first gas-liquid heat exchanger to exchange heat with the medium-quality heat source, and the high-pressure gas after heat exchange is finished is straightThe air turbine is connected into the air turbine to drive the first generator to generate electricity, and then the step I is carried out; wherein, P_1.tIs the actual output power, P, of the first generator_1.mThe output power of the first generator when the air turbine is operated under the rated power generation load, t is a scheduling time interval, delta t_maxOperating time for the air turbine at higher power generation loads;

step seven: opening a third electric regulating valve, throttling high-pressure air through the third electric regulating valve, then, enabling the high-pressure air to enter a heat regenerator to exchange heat with secondarily utilized high-temperature flue gas, enabling the heat-exchanged high-pressure air to enter a combustion chamber, simultaneously introducing natural gas into the combustion chamber through a natural gas storage tank, enabling the natural gas and the high-pressure air to be mixed and combusted in the combustion chamber, enabling the formed high-temperature flue gas to directly enter a gas turbine to drive a second generator to generate electricity, adjusting the air outlet flow of the natural gas storage tank through a fourth electric regulating valve along with the change of the required electricity generation load, and then, turning to the step one;

step eight: and confirming that the first quick closing valve and the second quick closing valve are in a closed state, and stopping generating power by the system.

The invention has the beneficial effects that:

according to the compressed air energy storage system and the method capable of improving the electricity-electricity conversion efficiency, the two power generation modes of the after-combustion type and the non-after-combustion type are combined for the first time, and the defect of low system charging efficiency caused by high air pressure lower limit constraint of the air storage tank is effectively overcome; under the power generation working condition of the system, when the air pressure value in the air storage tank is at a higher position, the non-afterburning power generation assembly generates power, and high-pressure gas exhausted by the air storage tank is throttled and then exchanges heat with the high-pressure gas by using a low-quality heat source, so that the working capacity of a unit working medium can be improved; when the air turbine is operated at a high power generation load for a long time, the reduction rate of the air pressure value in the air storage tank is increased, and then a high-quality heat source is used for exchanging heat with high-pressure air so as to save the air used by the air storage tank when the air pressure value is at a high level; when the air pressure value in the air storage tank is low, the afterburning power generation assembly generates power to increase the gas utilization depth of the air storage tank, so that the system is ensured to only perform one charge-discharge cycle in one scheduling period, and finally the electricity-electricity conversion efficiency of the system is improved.

Drawings

FIG. 1 is a schematic diagram of a compressed air energy storage system according to the present invention for improving the electrical-to-electrical conversion efficiency;

FIG. 2 is a flow chart of a compressed air energy storage method of the present invention for improving the efficiency of electricity-to-electricity conversion;

FIG. 3 is a graph comparing the output curves of the present invention and a conventional non-afterburning system during a scheduling period;

in the figure, 1-motor, 2-compressor group, 3-gas storage tank, 4-first gas-liquid heat exchanger, 5-second gas-liquid heat exchanger, 6-air turbine, 7-first generator, 8-regenerator, 9-natural gas storage tank, 10-combustion chamber, 11-gas turbine, 12-second generator, 13-three-way valve, 14-first quick-closing valve, 15-second quick-closing valve, 16-first electric regulating valve, 17-second electric regulating valve, 18-third quick-closing valve, 19-third electric regulating valve, 20-fourth electric regulating valve, 21-fourth quick-closing valve.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

As shown in fig. 1, a compressed air energy storage system capable of improving electricity-electricity conversion efficiency includes a motor 1, a compressor unit 2, an air storage tank 3, a three-way valve 13, a non-afterburning power generation assembly and an afterburning power generation assembly; the non-afterburning power generation assembly comprises a first gas-liquid heat exchanger 4, a second gas-liquid heat exchanger 5, an air turbine 6 and a first generator 7; the afterburning power generation assembly comprises a heat regenerator 8, a natural gas storage tank 9, a combustion chamber 10, a gas turbine 11 and a second generator 12; a motor shaft of the motor 1 is fixedly connected with a power input shaft of the compressor unit 2, an air outlet of the compressor unit 2 is communicated with an air inlet of the air storage tank 3 through a first quick-closing valve 14, and an air outlet of the air storage tank 3 is communicated with an air inlet of the three-way valve 13 through a second quick-closing valve 15; a first air outlet of the three-way valve 13 is output in two paths, the first path is communicated with an air inlet of the first gas-liquid heat exchanger 4 through a first electric regulating valve 16, the second path is communicated with an air inlet of the second gas-liquid heat exchanger 5 through a second electric regulating valve 17, air outlets of the first gas-liquid heat exchanger 4 and the second gas-liquid heat exchanger 5 are connected into a path in a junction mode and communicated with an air inlet of the air turbine 6 through a third quick-closing valve 18, an air outlet of the air turbine 6 is communicated with the atmosphere, and a power output shaft of the air turbine 6 is fixedly connected with a motor shaft of the first generator 7; a heat source introduced into the liquid inlet of the first gas-liquid heat exchanger 4 is a medium-quality heat source, and the temperature of the heat source is about 500 ℃; a heat source introduced into the liquid inlet of the second gas-liquid heat exchanger 5 is a low-quality heat source, and the temperature of the heat source is about 200 ℃; a second air outlet of the three-way valve 13 is communicated with a cold-end air inlet of the heat regenerator 8 through a third electric regulating valve 19, a cold-end air outlet of the heat regenerator 8 is communicated with an air inlet of the combustion chamber 10, a gas outlet of the natural gas storage tank 9 is communicated with a gas inlet of the combustion chamber 10 through a fourth electric regulating valve 20, a flue gas outlet of the combustion chamber 10 is communicated with an air inlet of the gas turbine 11 through a fourth quick closing valve 21, an air outlet of the gas turbine 11 is communicated with a hot-end air inlet of the heat regenerator 8, and a hot-end air outlet of the heat regenerator 8 is communicated with the atmosphere; and a power output shaft of the gas turbine 11 is fixedly connected with a motor shaft of the second generator 12.

A compressed air energy storage method capable of improving the electricity-electricity conversion efficiency is disclosed, a flow chart of the compressed air energy storage method is shown in figure 2, and the compressed air energy storage system capable of improving the electricity-electricity conversion efficiency is adopted, and the compressed air energy storage method comprises the following steps:

the method comprises the following steps: measuring the air pressure in the air reservoir 3, and recording the measured air pressure as P_cq.t；

Step two: judging whether the system receives a charging/generating command; if a charging command is received, turning to the third step; if a power generation command is received, turning to the fourth step; if no command is received, keeping the first quick closing valve 14 and the second quick closing valve 15 in a closed state;

step three: confirming that the second quick closing valve 15 is closed, and determining whether the air pressure in the air storage tank 3 satisfies P_cq.t<P_cq.maxIn which P is_cq.maxIs the upper limit of the air pressure value in the air storage tank 3; when a plurality of conditions are met, the first quick closing valve 14 is opened, and the motor 1 is started and openedThe compressor unit 2 charges air into the air storage tank 3, and the step I is carried out; if the condition is not met, turning to the step eight;

step four: confirming that the first quick-closing valve 14 is closed, and determining whether the air pressure in the air storage tank 3 satisfies the lower limit constraint thereof, i.e., P_cq.t>γδP_eWherein P is_eIs the air pressure of the surrounding environment of the system, gamma is the air depth correction coefficient and satisfies 0.5<γ<1, δ is an ambient air pressure multiple determined according to the rated load power of the air turbine 6; if the lower limit constraint is met, the second quick closing valve 15 is opened, and the operation is switched to the fifth step; if the lower limit constraint is not met, turning to the step eight;

step five: if P is satisfied_cq.t>δP_eOpening a first air outlet of the three-way valve 13, and turning to the step six; if gamma delta P is satisfied_e<P_cq.t<γP_eOpening a second air outlet of the three-way valve 13, and turning to the seventh step;

step six: judging whether the air turbine 6 is in a high power generation load operation state for a long time whenWhen the first electric regulating valve 16 is turned off, the high-pressure gas is subjected to pressure reduction through the second electric regulating valve 17, then enters the second gas-liquid heat exchanger 5 to perform heat exchange with the low-quality heat source, the high-pressure gas after heat exchange is directly enters the air turbine 6 to drive the first generator 7 to generate power, and then the step I is carried out; when in use

When the first electric control valve 17 is turned off, the high-pressure gas is subjected to pressure reduction through the first electric control valve 16, then enters the first gas-liquid heat exchanger 4 to exchange heat with the medium-quality heat source, the high-pressure gas after heat exchange directly enters the air turbine 6 to drive the first generator 7 to generate power, and then the step I is carried out; wherein, P_1.tIs the actual output power, P, of the first generator 7_1.mFor the first generator when the air turbine 6 is operating at rated load7, t is the scheduling period, Δ t_maxFor the operating time of the air turbine 6 at a higher power generation load;

step seven: the third electric regulating valve 19 is opened, high-pressure air is throttled through the third electric regulating valve 19 and then enters the heat regenerator 8 to exchange heat with high-temperature flue gas which is secondarily utilized, the high-pressure air which completes heat exchange enters the combustion chamber 10, meanwhile, natural gas is introduced into the combustion chamber 10 from the natural gas storage tank 9, the natural gas and the high-pressure air are mixed and combusted in the combustion chamber 10, the formed high-temperature flue gas directly enters the gas turbine 11 to drive the second generator 12 to generate electricity, the outlet flow of the natural gas storage tank 9 is adjusted through the fourth electric regulating valve 20 along with the change of the required electricity generation load, and then the step one is carried out;

step eight: and confirming that the first quick-closing valve 14 and the second quick-closing valve 15 are in the closing state, and stopping the power generation of the system.

Taking a traditional non-afterburning system adopting single-stage compression and single-stage expansion as an example, the system exchanges heat with high-pressure gas discharged by a gas storage tank through an external heat source, although the working capacity of a working medium is improved, the lower limit of the gas pressure of the gas storage tank is still higher, and the total electricity generation amount is limited when the gas pressure of the gas storage tank reaches the upper limit; as shown in fig. 3, it can be seen in fig. 3 that the conventional non-afterburning type system is operated at 9: 00 to 12: 00 is in the operating condition of discharging, considers that the gas holder atmospheric pressure is in lower position, and the system is in 12: 00 to 14: 00, entering into a charging working condition to operate, and preparing for the power consumption peak of the next stage; at 18: 00 to 22: in the period of 00 hours, the system carries out secondary discharge operation, and finally, the system is charged in the electricity utilization valley period to complete the charge-discharge work of a scheduling period; in the dispatching period, the traditional non-afterburning system carries out two-wheeled charging and discharging operation, and in the two charging processes, because the air pressure of the air storage tank is relatively high, the energy loss generated in the compressor unit and the transmission pipeline is high, and finally the electricity-electricity conversion efficiency of the system in the dispatching period is reduced.

In contrast to the present invention, taking a four-stage compression and single-stage expansion compressed air energy storage system as an example, the present invention combines two power generation modes of an after-combustion type and a non-after-combustion type, as shown in fig. 3, and as can be seen in fig. 3, the present invention is implemented in a mode of 9: 00 to 13: 00 is in a discharge working condition running state, and the discharge working condition is 12: after 00, the system is not charged because the available gas depth of the gas storage tank is increased; at 18: 00 to 21: 00 the system enters the discharging working condition again to operate; at 21: when the pressure of the system is insufficient, stopping discharging operation; at 23: 00 to day 6: 00, the system is switched to a charging working condition, and at the moment, because the air pressure of the air storage tank is at a low level, the energy loss caused in the charging process is reduced, and finally the electricity-electricity conversion efficiency of the system in the dispatching cycle is improved.