CN106437885A - Compressed air energy storage system - Google Patents

Abstract

The compressed air energy storage system provided by the present invention includes a compression unit, an expansion unit, a gas storage unit, a heat storage unit, a heat exchange unit, and an electric energy unit. The compression unit includes a low-pressure compressor unit and a high-pressure compressor unit. The expansion The unit includes a low-pressure stage expansion unit and a high-pressure stage expansion unit. The compression unit and the expansion unit used in the present invention are all combined structures, and two compressors or expanders of the same type that rotate in opposite directions with the rotating shaft are used as a set. One set or The parallel operation of multiple sets of units constitutes one level, and the series operation of two or more units constitutes the entire compression unit and expansion unit, which is conducive to meeting various levels of energy storage requirements on the one hand, and on the other hand can adapt to different lengths of operation The cycle, moreover, helps to counteract the axial forces and improve the stability of the whole system.

Description

A compressed air energy storage system

technical field

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

Background technique

In recent years, the peak-to-valley difference of traditional power grids in my country has been increasing day by day. There are two main reasons for this: first, more and more large intermittent power units are integrated into the power grid; second, wind power, photovoltaics, etc. Intermittent renewable energy generation is increasing. The incorporation of these intermittent power users and power sources has greatly increased the peak-to-valley difference in the traditional power grid dominated by coal power, and some areas have even had to use power rationing to solve this problem. This has brought about increasingly serious energy waste, and more and more affects people's daily life and even production work. In order to ensure the safe and economical operation of the power grid, it is imperative to configure an electric energy storage system.

At present, there are many kinds of electric energy storage systems, which can be mainly divided into the following three categories: mechanical energy storage (pumped water energy storage, compressed air energy storage, flywheel energy storage, etc.), electromagnetic energy storage (supercapacitors, etc.) and electrochemical energy storage ( lead-acid batteries, lithium-ion batteries, sodium-sulfur batteries, etc.). Among them, only pumped water storage and compressed air energy storage can reach more than 100MW in energy storage scale, so these two electric energy storage technologies are currently the most promising. However, pumped water energy storage technology has many disadvantages, so compressed air energy storage technology is particularly important.

However, the field of compressed air energy storage technology in China is still in the theoretical research stage; from a global perspective, several sets of compressed air energy storage power stations have been put into operation, all of which are supplementary combustion, that is, compressed air from the gas storage It first enters the combustion chamber and combusts with fuel to increase its temperature, and then enters the gas turbine to do work. However, the post-combustion compressed air energy storage system has its inherent disadvantages, which are mainly manifested in the following two points: first, it requires a large amount of fuel, consumes a lot of energy, and will cause air pollution, aggravate carbon emissions, and is not friendly to the environment; Second, the heat generated in the compression process cannot be recycled, and the energy conversion efficiency of the system is low. Therefore, it is particularly important to develop non-supplementary combustion compressed air energy storage technology. However, due to the limited volume of the gas storage equipment in the general compressed air energy storage system, the discharge pressure of the high-pressure stage compressor continues to rise while the suction pressure of the high-pressure stage expander continues to decrease, which greatly affects the energy conversion efficiency of the system; at the same time The internal temperature of the compressor and expander varies greatly, which deviates far from the ideal isothermal condition, which also affects the energy conversion efficiency of the system.

Contents of the invention

In view of this, it is necessary to provide a compressed air energy storage system with good stability and high energy conversion efficiency for the defects of the existing technology.

To achieve the above object, the present invention adopts the following technical solutions:

A compressed air energy storage system, including a compression unit, an expansion unit, an air storage unit, a heat storage unit, a heat exchange unit and an electric energy unit:

The compression unit includes a low-pressure stage compressor unit, a high-pressure stage compressor unit connected in series with the low-pressure stage compressor unit, and an oil-gas separator for compression; the expansion unit includes a low-pressure stage expansion unit, a high-pressure compressor unit connected in series with the low-pressure stage expansion unit stage expansion unit and oil-gas separator for expansion; the gas storage unit includes a gas storage tank; the heat storage unit includes a high-temperature oil tank and a low-temperature oil tank; the heat exchange unit includes a cooler and a heater; the electric energy unit Including motor units and generating units; of which:

The electric motor unit converts electrical energy into mechanical energy and transmits it to the low-pressure stage compressor unit, which compresses the air to medium pressure, and the compressed medium-pressure air is introduced into the cooler, and the generated compression heat is passed through The cooler transfers to the thermal storage oil in the low-temperature oil tank;

The cooler transfers the heat of the medium-pressure air to the thermal storage oil introduced in the low-temperature oil tank, the heated thermal storage oil is introduced into the high-temperature oil tank, and the cooled medium-pressure air is introduced into the high-pressure stage a compressor unit, leading out the thermal storage oil in the low-temperature oil tank and spraying it into the high-pressure stage compressor unit to form a first oil-gas mixture;

After the first oil-gas mixture is separated by the oil separator for compression, the heated thermal storage oil is introduced into the high-temperature oil tank, and the compressed high-pressure air is stored in the air storage tank;

The high-pressure air is exported from the air storage tank and introduced into the high-pressure expansion unit to expand and perform work, and the thermal storage oil in the high-temperature oil tank is extracted and injected into the high-pressure expansion unit to form the second oil gas mixture;

The heater transfers the heat of the heat storage oil introduced into the high temperature oil tank to the medium pressure air, the cooled heat storage oil is introduced into the low temperature oil tank, and the heated medium pressure air is introduced into the low pressure air The stage expansion unit further expands and performs work, and the expansion work is converted into stable electric energy by the generator set and incorporated into the power grid.

In some embodiments, the low-pressure stage compressor units are composed of at least one set of identical compressor sets connected in parallel, wherein any one set of compressor sets is a speed type compressor or a displacement type compressor.

In some embodiments, each low pressure stage compressor train consists of two identical compressors running in opposite directions with co-rotating axes.

In some embodiments, the high-pressure stage compressor unit is composed of at least one set of parallel compressor units, wherein any set of compressor units is a screw compressor that facilitates pressure ratio adjustment, and its suction pressure is constant, and its discharge pressure is constant. Can be changed within a certain range.

In some embodiments, each set of high-pressure stage compressor units is composed of two screw compressors with co-rotating shafts running in opposite directions.

In some embodiments, the low-pressure stage expansion unit is composed of at least one set of identical expansion units connected in parallel, wherein any set of expansion units is a turbo expander or a piston expander.

In some embodiments, each set of low-pressure stage expanders is composed of two identical expanders with co-rotating axes running in opposite directions.

In some embodiments, the high-pressure stage expansion unit is composed of at least one set of the same expansion unit connected in parallel, wherein any set of expansion unit is a screw type expander that facilitates pressure ratio adjustment, and its suction pressure can be within a certain range changes, the exhaust pressure is constant.

In some embodiments, each high-pressure stage expansion unit is composed of two screw expanders with co-rotating shafts running in opposite directions.

In some embodiments, the cooler is a dividing wall heat exchanger.

In some embodiments, the heater is a dividing wall heat exchanger.

The present invention adopts the beneficial effect of above-mentioned technical scheme to be:

The compressed air energy storage system provided by the present invention includes a compression unit, an expansion unit, a gas storage unit, a heat storage unit, a heat exchange unit, and an electric energy unit. The compression unit includes a low-pressure compressor unit and a high-pressure compressor unit. The expansion The unit includes a low-pressure stage expansion unit and a high-pressure stage expansion unit. The compression unit and the expansion unit used in the present invention are all combined structures, and two compressors or expanders of the same type that rotate in opposite directions with the rotating shaft are used as a set. One set or The parallel operation of multiple sets of units constitutes one level, and the series operation of two or more units constitutes the entire compression unit and expansion unit, which is conducive to adapting to various levels of energy storage requirements on the one hand, and on the other hand to adapt to different lengths of operation The cycle, moreover, helps to counteract the axial forces and improve the stability of the whole system.

At the same time, in the compressed air energy storage system provided by the present invention, the high-pressure compressor in the compression unit adopts a screw compressor, and the high-pressure expander in the expansion unit adopts a screw expander, which is convenient for adjusting the pressure ratio to adapt to the exhaust pressure during the compression process. The actual working condition of gradual increase and gradual decrease of the suction pressure during the expansion process improves the energy conversion efficiency of the system, and at the same time facilitates the realization of high-pressure oil injection heat exchange.

In addition, the compressed air energy storage system provided by the present invention cancels the high-pressure stage cooler and heater, and uses oil injection cooling and oil injection heating instead, thus eliminating the high-pressure stage cooler and heater, simplifying The system structure is optimized, and the operating environment of the high-pressure stage compressor and expander is optimized, and the compression efficiency and expansion efficiency are improved.

Finally, the compressed air energy storage system provided by the present invention can utilize various forms of electric energy, has a flexible operation cycle, a wide application range, is environmentally friendly, has high performance and stable operation, and has a good application prospect.

Description of drawings

Fig. 1 is the structural representation of the compressed air energy storage system provided by the present invention;

Fig. 2 is a schematic structural view of the compression unit in the compressed air energy storage system provided by the present invention;

Fig. 3 is a structural schematic diagram of the expansion unit in the compressed air energy storage system provided by the present invention;

Fig. 4 is a schematic structural diagram of the compressed air energy storage system provided by Embodiment 1 of the present invention;

Fig. 5 is a schematic structural diagram of the compressed air energy storage system provided by Embodiment 2 of the present invention.

in:

1/22/23/24/25-low-pressure stage compressor (group); 2-cooler; 3/26/27/28/29-high-pressure stage compressor (group); 4-compression oil separator; 5 -inlet valve; 6-air storage tank; 7-exhaust valve; 8/34/35/36/37-high pressure stage expander (group); 9-expansion oil separator; 10-heater; 11/ 38/39/40/41-low pressure stage expander (group); 12-high temperature oil tank; 13-high temperature stop valve; 14-high temperature oil pump; 15-high temperature regulating valve; 16-low temperature oil tank; 17-low temperature stop valve ; 18-low temperature oil pump; 19-low temperature regulating valve; 20/30/31-electric motor unit; 21/42/43-generator set; 44-medium temperature oil tank;

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Please refer to FIG. 1 , which is a schematic structural diagram of a compressed air energy storage system 100 provided by the present invention, including: a compression unit, an expansion unit, an air storage unit, a heat storage unit, a heat exchange unit and an electric energy unit.

Please refer to FIG. 2 , which is a schematic structural diagram of the compression unit provided by the present invention. The compression unit includes a low-pressure compressor unit, a high-pressure compressor unit connected in series with the low-pressure compressor unit, and an oil-gas separator 4 for compression.

Among them, the low-pressure stage compressor group consists of at least one set of identical compressors 1 (22/23, 24/25) connected in parallel, and the high-pressure stage compressor group consists of at least one set of identical compressors 3 (26/27, 28/29) connected in parallel composition. It can be understood that in order to offset the axial force generated by the rotation and improve the operation stability, each set of low-pressure stage compressor unit and high-pressure stage compressor unit is two identical compressors with co-rotating shafts running opposite to each other.

Specifically, the compressors in the low-pressure stage compressor group are the same speed-type compressors or volume-type compressors in any form; the compressors in the high-pressure stage compressor group are screw compressors that are convenient for pressure ratio adjustment and oil injection cooling, The exhaust pressure can be changed within a certain range, and it is equipped with a compression oil separator 4 to separate the high-temperature heat storage oil from the compressed air.

It can be understood that the displacement of the low-pressure compressor unit and the high-pressure compressor unit, the number of sets of compressors in the compressor unit, and the displacement of each compressor are determined by the compressed air flow required by the energy conversion system.

Please refer to Fig. 3, which is a schematic structural diagram of the expansion unit in the compressed air energy storage system provided by the present invention. The expansion unit includes a low-pressure expansion unit, a high-pressure expansion unit connected in series with the low-pressure expansion unit, and oil-gas separation for expansion. Device 9.

Wherein, the low-pressure stage expansion unit is composed of at least one set of identical expanders 11 (38/39, 40/41) connected in parallel. The high-pressure stage expansion unit is composed of at least one set of identical expanders 8 (34/35, 36/37) connected in parallel. It can be understood that in order to offset the axial force generated by the rotation and improve the operation stability, each set of low-pressure stage expansion The unit and the high-pressure expansion unit are two identical expanders with co-rotating shafts running in opposite directions.

Further, the expander in the low-pressure expansion unit is the same turbo expander or piston expander in any form; the expander in the high-pressure expansion unit is a screw expander that is convenient for pressure ratio adjustment and oil injection cooling , its exhaust pressure can vary within a certain range, and is equipped with an expansion side oil separator 9 to separate the low-temperature heat storage oil from the expansion air.

It can be understood that the displacement of the low-pressure stage expansion unit and the high-pressure stage expansion unit, the number of sets of compressors in the compressor unit, and the displacement of each expander are determined by the compressed air flow required by the energy conversion system.

Please refer to Fig. 1 again, the above-mentioned compressed air energy storage system 100 works as follows:

The motor unit 30 converts electrical energy into mechanical energy and transmits it to the low-pressure compressor unit 1, and the motor unit 31 converts electrical energy into mechanical energy and transmits it to the low-pressure compressor unit 3, and the low-pressure compressor unit 1 converts the The air is compressed to medium pressure, and the compressed medium pressure air is introduced into the cooler 2;

The cooler 2 transfers the heat of the medium-pressure air to the thermal storage oil introduced in the low-temperature oil tank 16, the heated thermal storage oil is introduced into the high-temperature oil tank 12, and the cooled medium-pressure air is introduced into the The high-pressure stage compressor unit 3 is drawn out of the heat storage oil in the low-temperature oil tank 16 and sprayed into the high-pressure stage compressor unit 3 to form a first oil-gas mixture;

After the first oil-gas mixture is separated by the compression oil separator 4, the heated thermal storage oil is introduced into the high-temperature oil tank 12, and the compressed high-pressure air is stored in the air storage tank 6 store;

The high-pressure air is exported from the air storage tank 6 and introduced into the high-pressure expansion unit 8 to expand and perform work, and the thermal storage oil in the high-temperature oil tank 12 is drawn out and injected into the high-pressure expansion unit 8 forming a second oil-gas mixture;

The second oil-air mixture is separated by the expansion oil separator 9, wherein the cooled thermal storage oil is introduced into the low-temperature oil tank 16, and the expanded medium-pressure air is introduced into the heater 10;

The heater 10 transfers the heat of the thermal storage oil introduced in the high temperature oil tank 12 to the medium pressure air, the cooled thermal storage oil is introduced into the low temperature oil tank 16, and the heated medium pressure air is introduced The low-pressure stage expansion unit 11 further expands and works, the high-pressure stage expansion work is converted into stable electric energy by the generator set 42 and incorporated into the grid, and the low-pressure stage expansion work is converted into stable electric energy by the generator set 43 and incorporated into the grid.

The compressed air energy storage system provided by the present invention includes a compression unit, an expansion unit, a gas storage unit, a heat storage unit, a heat exchange unit, and an electric energy unit. The compression unit includes a low-pressure compressor unit and a high-pressure compressor unit. The expansion The unit includes a low-pressure stage expansion unit and a high-pressure stage expansion unit. The compression unit and the expansion unit used in the present invention are all combined structures, and two compressors or expanders of the same type that rotate in opposite directions with the rotating shaft are used as a set. One set or The parallel operation of multiple sets of units constitutes one level, and the series operation of two or more units constitutes the entire compression unit and expansion unit, which is conducive to adapting to various levels of energy storage requirements on the one hand, and on the other hand to adapt to different lengths of operation The cycle, moreover, helps to counteract the axial forces and improve the stability of the whole system.

At the same time, in the compressed air energy storage system provided by the present invention, the high-pressure compressor in the compression unit adopts a screw compressor, and the high-pressure expander in the expansion unit adopts a screw expander, which is convenient for adjusting the pressure ratio to adapt to the exhaust pressure during the compression process. The actual working condition of gradual increase and gradual decrease of the suction pressure during the expansion process improves the energy conversion efficiency of the system, and at the same time facilitates the realization of high-pressure oil injection heat exchange.

In addition, the compressed air energy storage system provided by the present invention cancels the high-pressure stage cooler and heater, and uses oil injection cooling and oil injection heating instead, thus eliminating the high-pressure stage cooler and heater, simplifying The system structure is optimized, and the operating environment of the high-pressure stage compressor and expander is optimized, and the compression efficiency and expansion efficiency are improved.

Finally, the compressed air energy storage system provided by the present invention can utilize various forms of electric energy, has a flexible operation cycle, a wide application range, is environmentally friendly, has high performance and stable operation, and has a good application prospect.

The above-mentioned technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

Example 1

Please refer to FIG. 4 , which is a schematic structural diagram of the compressed air energy storage system provided by Embodiment 1 of the present invention.

Among them, the compression unit is two-stage compression, in which the low-pressure stage is a speed-type compressor unit, and the high-pressure stage is a screw-type expansion unit for easy pressure ratio adjustment; each stage is composed of two sets of compressor units, and each set of compressor units is composed of It consists of two rotating compressors of the same type; the low-pressure stage is cooled by a partition wall heat exchanger, and the high-pressure stage is cooled by oil injection. Its expansion unit is two-stage expansion, in which the high-pressure stage is a screw-type expansion unit that is convenient for pressure ratio adjustment, and the low-pressure stage is a speed-type expansion unit. Each stage is composed of two sets of expansion units. It consists of two expanders of the same type; the high-pressure stage is heated by oil injection, and the low-pressure stage is heated by a partition wall heat exchanger.

In the compression mode, the intake valve 6 is opened, the exhaust valve 8 is closed, the low-temperature cut-off valve 17 and the low-temperature regulating valve 19 are opened, the high-temperature cut-off valve 13 and the high-temperature regulating valve 15 are closed, the motor units 30, 31 and the low-temperature oil pump 18 are started, and power generation Units 41, 42 and high temperature oil pump 14 are out of service. The air at normal temperature and pressure is introduced into the low-pressure stage compressor unit of the compression unit, distributed to the compressors 22, 23, 24 and 25 and compressed into medium-pressure air, which absorbs the heat of compression and rises in temperature; then these four streams of air merge and enter the low-pressure At the same time, the low-temperature heat storage oil from the low-temperature oil tank 16 through the low-temperature shut-off valve 17 and the low-temperature oil pump 18 enters the oil side of the low-pressure stage cooler 2, and the two fluids perform partition heat exchange; The thermal storage oil is heated and then enters the high-temperature oil tank 12 for storage. The high-temperature medium-pressure air is cooled and then enters the high-pressure stage compressor unit, and is distributed to compressors 26, 27, 28 and 29 for further compression. The low-temperature thermal storage oil in the oil tank 16 through the low-temperature cut-off valve 17, low-temperature oil pump 18 and low-temperature regulating valve 19 enters the high-pressure compressor unit and is distributed to the compressors 26, 27, 28 and 29 for cooling, sealing and lubrication. Function; the oil-air mixture discharged from the high-pressure compressor unit enters the oil separator 4 on the compression side, and the high-temperature heat storage oil and high-pressure air are separated; the high-temperature heat storage oil enters the high-temperature oil tank 12 for storage, and the high-pressure air Enter the air storage tank 6 through the intake valve 5 and store it for later use.

After the compression mode ends, close the intake valve 6, the low temperature cut-off valve 17 and the low temperature regulating valve 19, and stop the motor units 30, 31 and the low temperature oil pump 18.

In the expansion mode, the intake valve 6 is closed, the exhaust valve 8 is opened, the low-temperature cut-off valve 17 and the low-temperature regulating valve 19 are closed, the high-temperature cut-off valve 13 and the high-temperature regulating valve 15 are opened, and the motor units 30, 31 and the low-temperature oil pump 18 are stopped. The generator sets 41, 42 and the high temperature oil pump 14 are started. The air at normal temperature and high pressure is introduced into the high-pressure expansion unit of the expansion unit through the exhaust valve 7 from the air storage tank 6, and is distributed to the expansion units 34, 35, 36 and 37 to be expanded into medium-pressure air, and the expansion work is output to the generator set 41 to generate electricity At the same time, the high-temperature heat storage oil drawn from the high-temperature oil tank 12 enters the high-pressure stage expansion unit through the high-temperature shut-off valve 13, the high-temperature oil pump 14 and the high-temperature regulating valve 15, and is distributed to the expansion machines 34, 35, 36 and 37 to play a role. The role of heating, sealing and lubrication; the oil-air mixture discharged from the high-pressure stage expansion unit enters the oil separator 9 on the expansion side, and the low-temperature heat storage oil and medium-pressure air are separated; the low-temperature heat storage oil enters the low-temperature oil tank 16 The medium-pressure air enters the air side of the low-pressure stage heater 10, and at the same time, the high-temperature heat storage oil drawn from the high-temperature oil tank 12 enters the oil side of the low-pressure stage heater 10 through the high-temperature stop valve 13 and the high-temperature oil pump 14. The two fluids perform partition heat exchange; the high-temperature thermal storage oil is cooled and then enters the low-temperature oil tank 16 for storage, and the low-temperature medium-pressure air is heated and then enters the low-pressure stage expansion unit, which is distributed to 38, 39, 40 and 41 Further expand in the air, and output the expansion work to the generator set 42 to generate electricity; the expanded air is discharged to the external environment, or enters other equipment to recover its cold energy.

After the expansion mode ends, close the exhaust valve 8, the high temperature cut-off valve 13 and the high temperature control valve 15, shut down the generator sets 42, 43 and the high temperature oil pump 14, and the whole system is finished.

Example 2

Please refer to FIG. 5 , which is a schematic structural diagram of a compressed air energy storage system provided by Embodiment 2 of the present invention.

Among them, the compression unit is two-stage compression, in which the low-pressure stage is a volumetric compressor unit, and the high-pressure stage is a screw-type expansion unit for easy pressure ratio adjustment; each stage is composed of two sets of compressor units, and each set of compressor units rotates with the same rotating shaft It consists of two compressors of the same type; the low-pressure stage is cooled by a partition wall heat exchanger, and the high-pressure stage is cooled by oil injection. Its expansion unit is two-stage expansion, in which the high-pressure stage is a screw-type expansion unit that is convenient for pressure ratio adjustment, and the low-pressure stage is a volumetric expansion unit. Each stage is composed of two sets of expansion units. It consists of two expanders of the same type; the high-pressure stage is heated by oil injection, and the low-pressure stage is heated by a partition wall heat exchanger.

In the compression mode, the intake valve 6 is opened, the exhaust valve 8 is closed, the low-temperature shut-off valve 17 and the low-temperature regulating valve 19 are opened, the medium-temperature shut-off valve 45 and the high-temperature shut-off valve 13 are closed, the electric motor unit 30/31 and the low-temperature oil pump 18 are started, and power generation Unit 41/42, medium temperature oil pump 46 and high temperature oil pump 14 are out of service. The air at normal temperature and pressure is introduced into the low-pressure stage compressor unit of the compression unit, distributed to the compressors 22, 23, 24 and 25 and compressed into medium-pressure air, which absorbs the heat of compression and rises in temperature; then these four streams of air merge and enter the low-pressure At the same time, the low-temperature heat storage oil from the low-temperature oil tank 16 through the low-temperature shut-off valve 17 and the low-temperature oil pump 18 enters the oil side of the low-pressure stage cooler 2, and the two fluids perform partition heat exchange; The thermal storage oil is heated and then enters the high-temperature oil tank 12 for storage. The high-temperature medium-pressure air is cooled and then enters the high-pressure stage compressor unit, and is distributed to compressors 26, 27, 28 and 29 for further compression. The low-temperature thermal storage oil in the oil tank 16 through the low-temperature cut-off valve 17, low-temperature oil pump 18 and low-temperature regulating valve 19 enters the high-pressure compressor unit and is distributed to the compressors 26, 27, 28 and 29 for cooling, sealing and lubrication. Function; the oil-air mixture discharged from the high-pressure compressor unit enters the oil separator 4 on the compression side, and the medium-temperature heat storage oil and high-pressure air are separated; the medium-temperature heat storage oil enters the medium-temperature oil tank 44 for storage, and the high-pressure air Enter the air storage tank 6 through the intake valve 5 and store it for later use.

After the compression mode ends, close the intake valve 6, the low temperature cut-off valve 17 and the low temperature regulating valve 19, and stop the motor units 30, 31 and the low temperature oil pump 18.

In the expansion mode, the intake valve 6 is closed, the exhaust valve 8 is opened, the low-temperature cut-off valve 17 and the low-temperature regulating valve 19 are closed, the medium-temperature cut-off valve 45 and the high-temperature cut-off valve 13 are opened, and the motor unit 30/31 and the low-temperature oil pump 18 are stopped. The generator set 41/42, the medium temperature oil pump 46 and the high temperature oil pump 14 start. The air at normal temperature and high pressure is introduced into the high-pressure expansion unit of the expansion unit through the exhaust valve 7 from the air storage tank 6, and is distributed to the expansion units 34, 35, 36 and 37 to be expanded into medium-pressure air, and the expansion work is output to the generator set 41 to generate electricity At the same time, the medium-temperature heat storage oil drawn from the medium-temperature oil tank 44 enters the high-pressure stage expansion unit through the medium-temperature cut-off valve 45 and the medium-temperature oil pump 46, and is distributed to the expanders 34, 35, 36 and 37 to play heating, sealing and lubrication The role of; from the high-pressure stage expansion unit discharge is the oil-gas mixture, which enters the expansion side oil separator 9, the low-temperature heat storage oil and medium-pressure air can be separated; wherein the low-temperature heat storage oil enters the low-temperature oil tank 16 for storage, and The medium-pressure air enters the air side of the low-pressure stage heater 10, and at the same time, the high-temperature thermal storage oil drawn from the high-temperature oil tank 12 enters the oil side of the low-pressure stage heater 10 through the high-temperature stop valve 13 and the high-temperature oil pump 14, and the two streams flow through the partition wall. heat exchange; the high-temperature heat storage oil is cooled and then enters the low-temperature oil tank 16 for storage, and the low-temperature medium-pressure air is heated and then enters the low-pressure stage expansion unit, which is distributed to 38, 39, 40 and 41 for further expansion, and Output the expansion work to the generator set 42 to generate electricity; the expanded air is discharged to the external environment, or enters other equipment to recover its cold energy.

After the expansion mode ends, close the exhaust valve 8, the medium-temperature shut-off valve 45 and the high-temperature shut-off valve 13, shut down the generating set 42/43, the medium-temperature oil pump 46 and the high-temperature oil pump 14, and the whole system is finished.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the technical content disclosed above to make some changes or modify them into equivalent embodiments with equivalent changes, but as long as they do not depart from the technical solution of the present invention, the Technical Essence Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (11)

1. a kind of compressed-air energy-storage system is it is characterised in that include compression unit, expansion cell, gas storage unit, accumulation of heat list Unit, heat exchange unit and electric energy unit：

Described compression unit include high pressure stage compressor group that low-pressure stage compressor bank connected with described low-pressure stage compressor bank and Compression gs-oil separator；Described expansion cell includes low-pressure stage and expands unit and the height of described low-pressure stage expansion units connected in series Arbitrarily downgrade and expand unit and expansion gs-oil separator；Described gas storage unit includes air accumulator；Described thermal storage unit includes high temperature oil Tank and low temperature oil tank；Described heat exchange unit includes cooler and heater；Described electric energy unit includes motor unit and electromotor Group；Wherein：

Described motor unit converts electrical energy into mechanical energy and passes to described low-pressure stage compressor bank, described low-pressure stage compressor bank Compress air to middle pressure, the middle pressure air after compression is introduced into described cooler, the heat of compression of generation passes through described cooler It is handed to the accumulation of heat oil in described low temperature oil tank；

The heat transfer of middle pressure air is given the accumulation of heat oil introducing in described low temperature oil tank by described cooler, the accumulation of heat oil after heating It is introduced into described high temperature oil tank, the middle pressure air after cooling is introduced into described high pressure stage compressor group, draw described low temperature oil tank Interior accumulation of heat oil simultaneously sprays into and forms the first gas mixture to described high pressure stage compressor group；

After described compression is separated with oil eliminator, wherein, the accumulation of heat oil after heating is introduced into described first gas mixture To described high temperature oil tank, the pressure-air after compression is stored in storage in described air accumulator；

Described pressure-air is derived from described air accumulator and is introduced to described hiigh pressure stage and expands expansion work in unit, described height Accumulation of heat oil in warm oil tank is drawn and is sprayed into and expands unit formation the second gas mixture to described hiigh pressure stage；

The heat transfer of the accumulation of heat being introduced in described high temperature oil tank oil is given middle pressure air by described heater, the accumulation of heat oil after cooling It is introduced in described low temperature oil tank, the middle pressure air after heating is introduced into described low-pressure stage and expands the further expansion work of unit, Expansion work is converted into stable electric energy through described generating set and is connected to the grid.

2. compressed-air energy-storage system according to claim 1 is it is characterised in that described low-pressure stage compressor bank is by least A set of identical compressor bank composes in parallel, and wherein, any one set compressor bank is velocity profile compressor or displacement type compressor.

3. compressed-air energy-storage system according to claim 2 is it is characterised in that wherein often set compressor bank is common by two The identical compressor composition of the opposite operating of rotary shaft.

4. compressed-air energy-storage system according to claim 1 is it is characterised in that described high pressure stage compressor group is by least A set of identical compressor bank composes in parallel, wherein, the screw compressor that any one set compressor bank is adjusted for ease of pressure ratio, Its pressure of inspiration(Pi) is constant, and pressure at expulsion can change within the specific limits.

5. compressed-air energy-storage system according to claim 4 is it is characterised in that wherein often set compressor bank is common by two The helical-lobe compressor composition of the opposite operating of rotary shaft.

6. compressed-air energy-storage system according to claim 1 is it is characterised in that described low-pressure stage expands unit by least A set of identical expands unit and composes in parallel, and wherein, arbitrarily a set of decompressor group is turbo-expander or piston expansion engine.

7. compressed-air energy-storage system according to claim 6 is it is characterised in that wherein often set expands unit by two altogether The same expansion machine composition of the opposite operating of rotary shaft.

8. compressed-air energy-storage system according to claim 1 is it is characterised in that described hiigh pressure stage expands unit by least A set of identical expands unit and composes in parallel, wherein, the screw type expansion machine that arbitrarily a set of decompressor group is adjusted for ease of pressure ratio, Its pressure of inspiration(Pi) can change within the specific limits, and pressure at expulsion is constant.

9. compressed-air energy-storage system according to claim 8 is it is characterised in that wherein often set expands unit by two altogether The screw expander composition of the opposite operating of rotary shaft.

10. compressed-air energy-storage system according to claim 1 is it is characterised in that described cooler is wall-type heat exchange Device.

11. compressed-air energy-storage systems according to claim 1 are it is characterised in that described heater is wall-type heat exchange Device.