CN111305920A - A steam-driven air energy storage peak regulation system and method - Google Patents

Abstract

The invention discloses a steam-driven air energy storage peak shaving system and a method, wherein the system consists of a first turbine set, a compressor, a cooler, a gas-liquid conversion device, a liquid air storage tank, a heater, an expander, a heat storage system cold tank, a heat storage system hot tank, a second turbine set, a condenser and a control valve; the operation method of the system comprises an energy storage mode and an energy release mode; the steam turbine directly driven by steam drives the compressor to compress air, the intermediate link from steam heat energy to electric energy to mechanical energy is eliminated, the compressor is directly driven by the high-speed steam turbine, the cost of the motor and the speed increaser is saved, the energy loss in the transmission process is reduced, the energy loss of the energy storage peak regulation system is greatly reduced on the whole, and the economical efficiency is improved; the purpose of additionally arranging the heat storage system is to recover heat generated in the compression process and improve the efficiency of the energy storage system.

Description

A steam-driven air energy storage peak regulation system and method

technical field

The invention belongs to the technical field of energy storage and peak regulation, and in particular relates to a steam-driven air energy storage peak regulation system and method, which is suitable for various thermal power plants typified by coal-fired units, and can improve the flexibility and economy of the coal-fired units. income.

Background technique

At present, my country's wind energy, solar energy and other renewable energy sources are developing rapidly year by year. In addition, the electricity consumption of the whole society is increasing year by year, and the peak-to-valley difference of power grid power consumption is increasing.

At present, the technologies for improving the peak regulation capacity of coal-fired units mainly include electric boiler heat storage technology, water tank heat storage technology, steam turbine steam process transformation technology, electrochemical battery energy storage technology, etc. It is used for heating, with strong peak shaving ability, but the energy quality is greatly reduced, and it is only suitable for cogeneration units. The water tank heat storage technology and the steam turbine steam process transformation technology have good thermal economy and relatively low investment, but the peak shaving capacity is limited. , and only applies to cogeneration units. Electrochemical battery energy storage technology has fast response, small size, and short construction period, but has short lifespan, high average cost, and high safety risks. Whether it is suitable for large-scale energy storage implementation still needs engineering Demonstration verification.

SUMMARY OF THE INVENTION

In order to overcome the deficiencies of the peak regulation technology of the existing coal-fired units, the present invention proposes a steam-driven air energy storage peak regulation system and method. During the energy storage process, the steam turbine driven by the steam directly drives the compressor to compress the air, so as to avoid the use of steam heat energy. From the electrical energy to the mechanical energy, the compressor is directly driven by the high-speed steam turbine, which saves the cost of the motor and the speed increaser and reduces the energy loss during the transmission process, which greatly reduces the energy of the energy storage and peak regulation system as a whole. loss and improved economy.

In order to achieve the above objects, the present invention adopts the following technical solutions.

A steam-driven air energy storage peak regulation system, which consists of a first steam turbine unit 1, a compressor 2, a cooler 3, a gas-liquid conversion device 4, a liquid air storage tank 5, a heater 6, an expander 7, a heat storage system cooling Tank 8, first valve 9, heat storage system heat tank 10, second valve 11, second steam turbine unit 12, condenser 13, third valve 14 and fourth valve 15;

The first steam turbine unit 1 is connected to the compressor 2 through a connecting shaft, and directly drives the compressor 2 to rotate. The outlet of the compressor 2 is sequentially connected to the high temperature side inlet of the cooler 3, the high temperature side outlet of the cooler 3, and the cooling and liquefaction side of the gas-liquid conversion device 4. The inlet, the outlet of the cooling and liquefaction side of the gas-liquid conversion device 4, and the inlet of the liquid air storage tank 5; The inlet of the low temperature side of the heater 6, the outlet of the low temperature side of the heater 6 and the expander 7; the second steam turbine unit 12 is connected to the inlet of the first steam turbine unit 1 through the third valve 14, and the outlet of the first steam turbine unit 1 is connected to the condenser through the fourth valve 15. The inlet of 13 is communicated with the inlet of the second steam turbine unit 12; The inlet of the hot tank 10 is connected, the outlet of the hot tank 10 of the heat storage system is communicated with the inlet of the high temperature side of the heater 6 through the second valve 11, and the outlet of the high temperature side of the heater 6 is communicated with the inlet of the cold tank 8 of the heat storage system; the system is directly driven by steam. The steam turbine drives the compressor to compress the air, eliminating the intermediate link from steam heat energy to electrical energy to mechanical energy. The compressor is directly driven by the high-speed steam turbine, which saves the cost of the motor and speed increaser and reduces the energy loss during the transmission process. The energy loss of the energy storage peak-shaving system is greatly reduced, and the economy is improved.

The compressors 2 and the coolers 3 are of one or more stages, and the number of the compressors 2 and the coolers 3 is in one-to-one correspondence, and each stage of the compressor is connected to a corresponding cooler in series.

The heaters 6 and the expanders 7 are both of one or more stages, and the numbers of the heaters 6 and the expanders 7 are in one-to-one correspondence, and the corresponding expanders are connected in series after each stage of the heater.

The second steam turbine unit 12 includes a high pressure cylinder, a medium pressure cylinder and a low pressure cylinder which are connected in sequence.

The third valve 14 is communicated with the outlet of the medium pressure cylinder and the inlet of the low pressure cylinder in the second steam turbine unit 12, or other steam extraction positions are optimized and screened according to the conditions of the generator unit.

The heat storage system cold tank 8 and the heat storage system hot tank 10 are used to recover the compression heat generated during the compression process, thereby improving the efficiency of the energy storage system.

The system is suitable for cogeneration units and pure condensing units, which can greatly improve the peak shaving capacity of coal-fired units and reduce energy conversion links.

The operation method of the steam-driven air energy storage peak regulation system includes an energy storage mode and an energy release mode, and the details are as follows:

Energy storage mode: when the power consumption of the grid is low and the coal-fired unit needs to reduce the power generation load, the energy storage mode is turned on, the first valve 9, the third valve 14 and the fourth valve 15 are opened, and the second valve 11 is closed; 12 Enter the first steam turbine unit 1 through the third valve 14 to drive the first steam turbine unit 1 to rotate at a high speed. The exhausted steam from the first steam turbine unit 1 enters the condenser 13 through the fourth valve 15 to condense into water, and then continues to enter the coal-fired unit for thermal power System: The first steam turbine unit 1 drives the compressor 2 to compress the air through the connecting shaft, and the obtained high-temperature and high-pressure air enters the cooler 3, and the low-temperature heat storage medium enters the cooler 3 from the heat storage system cold tank 8 through the first valve 9 to cool the high temperature. High pressure air, the obtained high temperature heat storage medium is stored in the heat storage system heat tank 10, the normal temperature high pressure air at the high temperature side outlet of the cooler 3 is cooled and liquefied through the gas-liquid conversion device 4, and the low temperature liquid air enters the liquid air storage tank 5 for storage;

Energy release mode: The energy release mode is turned on when the power consumption of the grid peaks and the coal-fired unit needs to increase the power generation load, close the first valve 9, the third valve 14 and the fourth valve 15, and open the second valve 11; The storage tank 5 flows out, and the normal temperature and high pressure air generated after the cold energy recovery by the gas-liquid conversion device 4 enters the heater 6, and the high temperature heat storage medium enters the heater 6 from the heat storage system hot tank 10 through the second valve 11. Air, the obtained low-temperature heat storage medium is stored in the cold tank 8 of the heat storage system, and the high-temperature and high-pressure air at the low-temperature side outlet of the heater 6 enters the expander 7 to expand and perform work and output electric energy, and the outlet of the expander 7 is normal pressure and normal temperature air, which is discharged into surroundings.

Compared with the prior art, the present invention has the following advantages:

The steam-driven air energy storage peak regulation system and method of the invention is suitable for cogeneration units and pure condensing units. During the energy storage process, the steam turbine driven by the steam directly drives the compressor to compress the air, eliminating the need for steam thermal energy to electrical energy to mechanical energy. The compressor is directly driven by the high-speed steam turbine, which saves the cost of the motor and the speed increaser and reduces the energy loss during the transmission process, which greatly reduces the energy loss of the energy storage peak regulation system as a whole, and improves the economy. The purpose of adding a heat storage system is to recover the heat generated by the compression process and improve the efficiency of the energy storage system.

Description of drawings

FIG. 1 is a schematic diagram of the system of the present invention.

In the picture:

1-The first steam turbine unit 2-Compressor 3-Cooler 4-Gas-liquid conversion device

5-Liquid air storage tank 6-Heater 7-Expander 8-Heat storage system cold tank

9- The first valve 10- Heat storage system heat tank 11- The second valve 12- The first steam turbine unit

13-condenser 14-third valve 15-fourth valve

Detailed ways

The patent of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments described herein are only used to explain the present invention, and are not intended to limit the present invention.

As shown in Figure 1, a steam-driven air energy storage peak regulation system of the present invention consists of a first steam turbine unit 1, a compressor 2, a cooler 3, a gas-liquid conversion device 4, a liquid air storage tank 5, a heater 6, Expander 7 , heat storage system cold tank 8 , first valve 9 , heat storage system heat tank 10 , second valve 11 , second steam turbine unit 12 , condenser 13 , third valve 14 and fourth valve 15 .

The first steam turbine unit 1 is connected to the compressor 2 through the connecting shaft, and directly drives the compressor 2 to rotate. The outlet of the compressor 2 is sequentially connected to the high temperature side inlet of the cooler 3, the high temperature side outlet of the cooler 3, the cooling and liquefaction side inlet of the gas-liquid conversion device 4, The outlet on the cooling and liquefying side of the gas-liquid conversion device 4 and the inlet of the liquid air storage tank 5; Low temperature side inlet, low temperature side outlet of heater 6 and expander 7; the second steam turbine unit 12 is connected to the inlet of the first steam turbine unit 1 through the third valve 14, and the outlet of the first steam turbine unit 1 is connected to the inlet of the condenser 13 through the fourth valve 15 The outlet of the second steam turbine unit 12 is communicated with the inlet of the condenser 13; the outlet of the cold tank 8 of the heat storage system is communicated with the low temperature side inlet of the cooler 3 through the first valve 9, and the low temperature side outlet of the cooler 3 is connected with the heat storage system hot tank 10 The inlet is connected, the outlet of the hot tank 10 of the heat storage system is connected to the inlet of the high temperature side of the heater 6 through the second valve 11, and the outlet of the high temperature side of the heater 6 is connected to the inlet of the cold tank 8 of the heat storage system; the system is suitable for cogeneration units and pure The condensing unit can greatly improve the peak shaving capacity of the coal-fired unit and reduce the energy conversion link.

The steam-driven air energy storage peak regulation system of the present invention can operate according to the following energy storage mode and energy release mode.

Energy storage mode: when the power consumption of the grid is low and the coal-fired unit needs to reduce the power generation load, the energy storage mode is turned on, the first valve 9, the third valve 14 and the fourth valve 15 are opened, and the second valve 11 is closed; 12 Enter the first steam turbine unit 1 through the third valve 14 to drive the first steam turbine unit 1 to rotate at a high speed. The exhausted steam from the first steam turbine unit 1 enters the condenser 13 through the fourth valve 15 to condense into water, and then continues to enter the coal-fired unit for thermal power System: The first steam turbine unit 1 drives the compressor 2 to compress the air through the connecting shaft, and the obtained high-temperature and high-pressure air enters the cooler 3, and the low-temperature heat storage medium enters the cooler 3 from the heat storage system cold tank 8 through the first valve 9 to cool the high temperature. High-pressure air, the obtained high-temperature heat storage medium is stored in the heat storage system heat tank 10, the normal temperature high-pressure air at the high temperature side outlet of the cooler 3 is cooled and liquefied through the gas-liquid conversion device 4, and the low-temperature liquid air enters the liquid air storage tank 5 for storage.

Energy release mode: The energy release mode is turned on when the power consumption of the grid peaks and the coal-fired unit needs to increase the power generation load, close the first valve 9, the third valve 14 and the fourth valve 15, and open the second valve 11; The storage tank 5 flows out, and the normal temperature and high pressure air generated after the cold energy recovery by the gas-liquid conversion device 4 enters the heater 6, and the high temperature heat storage medium enters the heater 6 from the heat storage system hot tank 10 through the second valve 11. Air, the obtained low-temperature heat storage medium is stored in the cold tank 8 of the heat storage system, and the high-temperature and high-pressure air at the low-temperature side outlet of the heater 6 enters the expander 7 to expand and perform work and output electric energy, and the outlet of the expander 7 is normal pressure and normal temperature air, which is discharged into surroundings.

Although the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative rather than restrictive. Under the inspiration of the present invention, many modifications can be made without departing from the spirit of the present invention, which all belong to the protection of the present invention. Any insubstantial modification of the present invention by using this concept shall be regarded as an act infringing the protection scope of the present invention.

Claims (8)

1. The utility model provides a vapour drives air energy storage system of peaking which characterized in that: the system comprises a first turbine set (1), a compressor (2), a cooler (3), a gas-liquid conversion device (4), a liquid air storage tank (5), a heater (6), an expander (7), a heat storage system cold tank (8), a first valve (9), a heat storage system hot tank (10), a second valve (11), a second turbine set (12), a condenser (13), a third valve (14) and a fourth valve (15);

the first turbine set (1) is connected with the compressor (2) through a connecting shaft, the compressor (2) is directly driven to rotate, and an outlet of the compressor (2) is sequentially communicated with a high-temperature side inlet of the cooler (3), a high-temperature side outlet of the cooler (3), a cooling liquefaction side inlet of the gas-liquid conversion device (4), a cooling liquefaction side outlet of the gas-liquid conversion device (4) and an inlet of the liquid air storage tank (5); an outlet of the liquid air storage tank (5) is sequentially communicated with a cold energy recovery side inlet of the gas-liquid conversion device (4), a cold energy recovery side outlet of the gas-liquid conversion device (4), a low-temperature side inlet of the heater (6), a low-temperature side outlet of the heater (6) and the expander (7); the second turbine set (12) is communicated with the inlet of the first turbine set (1) through a third valve (14), the outlet of the first turbine set (1) is communicated with the inlet of the condenser (13) through a fourth valve (15), and the outlet of the second turbine set (12) is also communicated with the inlet of the condenser (13); an outlet of a cold tank (8) of the heat storage system is communicated with a low-temperature side inlet of a cooler (3) through a first valve (9), a low-temperature side outlet of the cooler (3) is communicated with an inlet of a hot tank (10) of the heat storage system, an outlet of the hot tank (10) of the heat storage system is communicated with a high-temperature side inlet of a heater (6) through a second valve (11), and a high-temperature side outlet of the heater (6) is communicated with an inlet of the cold tank (8) of the heat storage system; the system directly drives the compressor to compress air by the steam turbine driven by steam, the intermediate link from steam heat energy to electric energy and then mechanical energy is eliminated, the compressor is directly driven by the high-speed steam turbine, the cost of the motor and the speed increaser is saved, the energy loss in the transmission process is reduced, the energy loss of the energy storage peak regulation system is greatly reduced on the whole, and the economical efficiency is improved.

2. A steam drive air energy storage peak shaving system according to claim 1, characterized in that: the compressor (2) and the cooler (3) are both in one stage or multiple stages, the number of the compressor (2) and the number of the cooler (3) are in one-to-one correspondence, and the corresponding coolers are connected in series behind each stage of the compressor.

3. A steam drive air energy storage peak shaving system according to claim 1, characterized in that: the heaters (6) and the expanders (7) are all in one stage or multiple stages, the number of the heaters (6) corresponds to that of the expanders (7), and the corresponding expanders are connected behind each stage of the heaters in series.

4. A steam drive air energy storage peak shaving system according to claim 1, characterized in that: the second turbine set (12) comprises a high-pressure cylinder, an intermediate-pressure cylinder and a low-pressure cylinder which are sequentially connected.

5. A steam drive air energy storage peak shaving system according to claim 4, characterized in that: and the third valve (14) is communicated with an outlet of an intermediate pressure cylinder and an inlet of a low pressure cylinder in the second steam turbine set (12), or the steam extraction position is optimally screened according to the condition of the generator set.

6. A steam drive air energy storage peak shaving system according to claim 1, characterized in that: the heat storage system cold tank (8) and the heat storage system hot tank (10) are used for recovering compression heat generated in the compression process, and the efficiency of the energy storage system is improved.

7. A steam drive air energy storage peak shaving system according to claim 1, characterized in that: the system is suitable for a cogeneration unit and a straight condensing unit, can greatly improve the peak regulation capacity of a coal-fired unit, and reduces energy conversion links.

8. The operation method of the steam-driven air energy-storage peak-shaving system according to any one of claims 1 to 7, characterized by comprising the following steps: the energy storage device comprises an energy storage mode and an energy release mode, and specifically comprises the following steps:

an energy storage mode: the energy storage mode is started when the power consumption of the power grid is low and the coal-fired unit is required to reduce the power generation load, the first valve (9), the third valve (14) and the fourth valve (15) are opened, and the second valve (11) is closed; steam enters the first steam turbine set (1) from the second steam turbine set (12) through the third valve (14) to push the first steam turbine set (1) to rotate at a high speed, and dead steam at the outlet of the first steam turbine set (1) enters the condenser (13) through the fourth valve (15) to be condensed into water and then continues to enter a thermal system of the coal-fired unit; the first turbine set (1) drives a compressor (2) to compress air through a connecting shaft, the obtained high-temperature and high-pressure air enters a cooler (3), a low-temperature heat storage medium enters the cooler (3) from a heat storage system cold tank (8) through a first valve (9) to cool the high-temperature and high-pressure air, the obtained high-temperature heat storage medium is stored in a heat storage system hot tank (10), the normal-temperature and high-pressure air at the high-temperature side outlet of the cooler (3) is cooled and liquefied through a gas-liquid conversion device (4), and the low-temperature liquid air enters a liquid air storage tank (5) to be stored;

energy release mode: starting an energy release mode when the power consumption peak of a power grid and the power generation load of a coal-fired unit need to be lifted, closing a first valve (9), a third valve (14) and a fourth valve (15), and opening a second valve (11); the low-temperature liquid air flows out from the liquid air storage tank (5), normal-temperature high-pressure air generated after cold energy recovery is carried out through the gas-liquid conversion device (4) enters the heater (6), high-temperature heat storage medium enters the heater (6) through the second valve (11) from the heat storage system hot tank (10) to heat the normal-temperature high-pressure air, the obtained low-temperature heat storage medium is stored in the heat storage system cold tank (8), the high-temperature high-pressure air at the low-temperature side outlet of the heater (6) enters the expansion machine (7) to be expanded to work and output electric energy, and the normal-pressure normal-temperature air at the outlet of the expansion machine (7) is discharged.

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