CN211777622U - Compressed air energy storage system coupled with coal-fired cogeneration unit - Google Patents

Abstract

The utility model discloses a compressed air energy storage system coupled with a coal-fired cogeneration unit. The system includes three parts: steam turbine system, heating network heating system and compressed air energy storage system. By coupling the steam turbine system and the compressed air energy storage system, the utility model stores excess electric energy through compressed air during the low electricity consumption period, and at the same time recovers the heat generated when the air is compressed to heat the return water of the heating network; when the electricity consumption load is high Release the steam extracted from the high-pressure cylinder of the steam turbine, heat the released compressed air, and make the compressed air enter the air expander to fully generate power and provide more electricity. The utility model can effectively improve the flexibility and economy of the coal-fired cogeneration unit.

Description

A compressed air energy storage system coupled with a coal-fired cogeneration unit

technical field

The utility model relates to the technical field of compressed air energy storage, in particular to an energy storage system coupled with a heat and power cogeneration unit, in particular to a compressed air energy storage system coupled with a coal-fired heat and power cogeneration unit.

Background technique

In recent years, with the rapid development of the national economy, the power load peak-to-valley difference in the power grid has gradually increased, and at the same time, users have higher and higher requirements for the quality of basic power consumption. Balance the load to adjust, so as to ensure the stable operation of the power system and meet the needs of users, that is, it is necessary to adjust the peak load of the power load. Under normal circumstances, the power grid relies on thermal power units, gas turbine units and other generating units for peak shaving. When configuring the generator set, reserve the load margin, that is, the generator set works in a low-efficiency operating state of less than full load. During peak electricity consumption, increase the output of the generator set to ensure that customers use electricity; when the electricity consumption is low, reduce the output of the generator set to achieve a balance between the power supply side and the load side; that is, relying on frequent load adjustment for power grid peak regulation. Such a peak-shaving state is not only uneconomical and efficient, but also not conducive to the safe and stable operation of the unit. Taking a thermal power unit as an example, it is extremely unreasonable that thermal power units have higher coal consumption under frequent peak shaving conditions, shorten unit maintenance time, and increase operating costs. The booming energy storage technology in recent years can store the excess electric energy of new energy and other generator sets when the power consumption is low, especially when the load is low at night, and the stored electric energy can be stored in a reasonable way when the grid power consumption peaks. Release it, so as to achieve the purpose of peak shaving/peak shaving and valley filling. This can not only reasonably reduce the pressure on the power grid caused by the difference between urban peaks and valleys, but also have a scientific effect of energy saving and emission reduction.

Aiming at the cogeneration power plants in my country, the optimal operation of energy storage in the thermal power plant is proposed, that is, the steam turbine and the air compressor are coupled with the energy storage system to store and utilize the excess electric energy generated by the steam turbine unit during the low load period of the grid. In this newly proposed system, through the arrangement of the steam turbine and the air compressor, for the steam turbine unit, the extraction steam of the steam turbine unit is used to heat the return water and compressed air of the heating network, and the temperature of the return water and the compressed air of the heating network are increased. It effectively utilizes steam heat and increases the working capacity of compressed air, which not only realizes heat supply, but also improves energy utilization rate; for air compressor units, the air compressor utilizes the excess electric energy produced by the steam turbine unit during the low load period of the power grid. Compressed air enters the gas storage tank for storage. During the peak load period of the power grid, the compressed air is released into the air expander to generate power, which can effectively reduce the power loss of the steam turbine unit and improve the peak regulation capacity of the steam turbine unit.

SUMMARY OF THE INVENTION

The utility model provides a compressed air energy storage system coupled with a coal-fired heat and power co-generation unit to solve the problem of excess electric energy when the steam turbine unit operates in the low load period of the power grid. Energy and peak regulation, use the extraction steam from the communication pipe between the low-pressure cylinders in the steam turbine to heat the return water of the heating network for heating, and use the last-stage extraction steam from the high-pressure cylinder of the steam turbine to heat the compressed air, so that the compressed air can be compressed. After the air absorbs heat, it enters the air expander to do work and generate electricity. By coupling the steam turbine system and the compressed air energy storage system, the utility model stores excess electric energy through compressed air during the low electricity consumption period, and at the same time recovers the heat generated when the air is compressed to heat the return water of the heating network; when the electricity consumption load is high Release the steam extracted from the final stage of the high-pressure cylinder of the steam turbine to heat the released compressed air, so that the compressed air enters the air expander to fully generate power and provide more electric power, which effectively improves the flexibility and economy of the coal-fired cogeneration unit.

To achieve the above object, the utility model adopts the following technical solutions:

A compressed air energy storage system coupled with a coal-fired cogeneration unit, the system mainly includes a steam turbine system, a heating network heating system and a compressed air energy storage system; it is characterized in that, in the steam turbine system, the steam turbine high-pressure cylinder It is connected in series with the medium pressure cylinder of the steam turbine, the last stage extraction port of the high pressure cylinder of the steam turbine is connected to the steam inlet of the No. 2 heater, the steam outlet of the connecting pipe of the medium and low pressure cylinder of the steam turbine is connected to the steam inlet of the No. The low pressure cylinder of the steam turbine is connected in series, and the low pressure cylinder of the steam turbine is connected in series with the No. 1 generator; in the heating network heating system, the water outlet of the No. 1 heat exchanger is connected with the water inlet of the No. 3 heat exchanger; in the compressed air energy storage system, the No. 1 generator It is connected with the air compressor, the exhaust port of the air compressor is connected with the air inlet of the No. 1 heat exchanger, the exhaust port of the No. 1 heat exchanger is connected with the air inlet of the air storage tank, and the air outlet of the air storage tank is connected with the No. 2 heat exchange The air outlet of the No. 2 heat exchanger is connected to the air inlet of the air expander, and the air expander is connected in series with the No. 2 generator.

The turbine system uses the surplus electric energy generated by the No. 1 generator during the low load period of the grid for the air compressor to compress the air, and stores the compressed air in the air storage tank. The electric energy that would have been wasted during the low load period of the grid is effectively stored, saving energy and improving the energy utilization efficiency of the entire system.

The network heating system makes the extraction steam from the connecting pipe of the low-pressure cylinder in the steam turbine pass through the No. 3 heat exchanger, heats the return water of the heating network, and passes the high-temperature compressed gas compressed by the air compressor through the No. 1 heat exchanger for heating. The return water from the heating network is used for heating.

The compressed air energy storage system absorbs the excess electric energy produced by the steam turbine system during the low load period of the power grid, and the air is compressed by the air compressor and enters the air storage tank. The No. 1 heat exchanger absorbs the heat from the final stage extraction steam of the high-pressure cylinder of the steam turbine, and then enters the air expander to do work, and drives the No. 2 generator to generate electricity.

The utility model has the following advantages and effects:

1) The excess electric energy during the grid load trough period is used to compress the air in the air compressor, and the compressed air is stored in the air storage tank. The electric energy that would have been wasted during the grid load trough period is effectively stored, saving energy, Improve the energy utilization efficiency of the whole system;

2) The thermal energy of the compressed air is used to heat the return water of the heating network. Under the original operating conditions of the steam turbine unit, energy is saved, the energy utilization efficiency of the entire system is improved, and the thermal economy of the steam turbine unit is optimized;

3) The sliding adjustment of the power generation of the steam turbine unit is realized, and the corresponding electric energy can be output flexibly according to the load condition of the power grid, which improves the peak regulation capacity of the steam turbine unit.

Description of drawings

Figure 1 is a schematic diagram of a compressed air energy storage system coupled with a coal-fired cogeneration unit.

In the figure: 1- Turbine high pressure cylinder; 2- Turbine medium pressure cylinder; 3- Turbine low pressure cylinder; 4- No. 1 generator; 5- Air compressor; 6- No. 1 heat exchanger; 7- Air storage tank; 8 - No. 2 heat exchanger; 9 - Air expander; 10 - No. 2 generator; 11 - No. 3 heat exchanger.

Detailed ways

The utility model proposes a compressed air energy storage system coupled with a coal-fired cogeneration unit, which is described below with reference to the accompanying drawings and examples.

As shown in Figure 1, a compressed air energy storage system coupled with a coal-fired cogeneration unit, the system mainly includes a steam turbine system, a heating network heating system and a compressed air energy storage system; it is characterized in that the steam turbine In the system, the high-pressure cylinder 1 of the steam turbine is connected in series with the medium-pressure cylinder 2 of the steam turbine, the last-stage extraction port of the high-pressure cylinder 1 of the steam turbine is connected to the steam inlet of the No. 2 heater 8, and the medium-low pressure cylinder of the steam turbine is connected to the steam outlet of the No. 3 heat exchanger. 11. The steam inlet is connected, the steam turbine medium pressure cylinder 2 is connected in series with the steam turbine low pressure cylinder 3, and the steam turbine low pressure cylinder 3 is connected in series with the No. 1 generator 4; in the heating network heating system, the No. 1 heat exchanger 6 water outlet and No. 3 heat exchange In the compressed air energy storage system, the No. 1 generator 4 is connected to the air compressor 5, the exhaust port of the air compressor 5 is connected to the air inlet of the No. 1 heat exchanger 6, and the No. 1 heat exchanger 6 The exhaust port is connected to the air inlet of the air storage tank 7, the air outlet of the air storage tank 7 is connected to the air inlet of the second heat exchanger 8, the air outlet of the second heat exchanger 8 is connected to the air inlet of the air expander 9, and the air The expander 9 is connected in series with the second generator 10 .

The steam turbine system uses the excess electric energy generated by the No. 1 generator 4 during the grid load trough period to be used for the air compressor 5 to compress the air, and the compressed air is stored in the air storage tank 7 . The electric energy that would have been wasted during the low load period of the grid is effectively stored, saving energy and improving the energy utilization efficiency of the entire system.

The described network heating system makes the extraction steam from the low-pressure cylinder connecting pipe of the steam turbine pass through the No. 3 heat exchanger 11, heats the return water of the heating network, and passes the high-temperature compressed gas compressed by the air compressor 5 through the No. 1 heat exchanger. 6. The return water of the heating network is used for heating.

The described compressed air energy storage system absorbs the excess electric energy produced by the steam turbine system during the low load period of the power grid, and the air is compressed by the air compressor 5 and then enters the air storage tank 7, and the air storage tank 7 releases the compressed air during the peak load period of the power grid, And through the No. 2 heat exchanger 8 to absorb the heat from the final stage extraction steam of the high-pressure cylinder of the steam turbine, it enters the air expander 9 to do work, and drives the No. 2 generator 10 to generate electricity.

The specific control process is illustrated below in conjunction with the embodiment:

When the steam turbine system operates under the grid load trough period, steam is extracted from the connecting pipe between the middle and low pressure cylinders of the steam turbine, and enters the No. 3 heat exchanger 11 to heat the return water of the heating network, and the excess electric energy produced by the No. 1 generator 4 Used for air compressor 5, the compressed air enters No. 1 heat exchanger 6 to heat the return water of the heating network and then enters the air storage tank 7; when the steam turbine system operates under the working conditions of the grid load peak period, the air storage tank 7 releases the compressed air , the steam is extracted from the connecting pipe between the low-pressure cylinders of the steam turbine, and enters the No. 3 heat exchanger 11 to heat the return water of the heating network, and the extraction steam from the last stage of the high-pressure cylinder 1 of the steam turbine enters the No. 2 heater 8 to heat the compressed air, so that the compressed air is fully Expand, push the air expander 9 to do work, and drive the No. 2 generator 10 to generate electricity.

By coupling the steam turbine system and the compressed air energy storage system, the system uses electric energy for compressed air during the low load period of the power grid, recovers the heat generated during air compression, and uses it to heat the return water of the heat network, and releases the compressed air during the peak load period of the power grid. The expansion works to generate electricity, avoiding the loss of electric energy, realizing the flexible peak regulation of the steam turbine unit, and improving the economy of the steam turbine unit.

In addition, it should be noted that, in the specific embodiments described in this specification, the shapes and names of the components thereof may be different. All equivalent or simple changes made according to the structure, features and principles described in the patent concept of the present utility model are included in the protection scope of the present utility model patent. Those skilled in the art to which the present invention pertains can make various modifications or additions to the described specific embodiments or substitute in similar manners, as long as they do not deviate from the structure of the present invention or go beyond what is defined in the claims. All should belong to the protection scope of the present invention.

Claims (4)

1. a compressed air energy storage system coupled with a coal-fired cogeneration unit, the system mainly comprises a steam turbine system, a heating network heating system and a compressed air energy storage system; it is characterized in that, in the described steam turbine system, the steam turbine The high-pressure cylinder (1) is connected in series with the middle-pressure cylinder (2) of the steam turbine, the last-stage extraction port of the steam-turbine high-pressure cylinder (1) is connected to the steam inlet of the No. No. 3 heat exchanger (11) is connected to the steam inlet, the steam turbine medium pressure cylinder (2) is connected in series with the steam turbine low pressure cylinder (3), and the steam turbine low pressure cylinder (3) is connected in series with the No. 1 generator (4); the heating network heating system In the middle, the water outlet of the No. 1 heat exchanger (6) is connected to the water inlet of the No. 3 heat exchanger (11); in the compressed air energy storage system, the No. 1 generator (4) is connected to the air compressor (5), and the air compresses The exhaust port of the engine (5) is connected to the air inlet of the No. 1 heat exchanger (6), and the exhaust port of the No. 1 heat exchanger (6) is connected to the air inlet of the air storage tank (7). The air storage tank (7) The air outlet is connected to the air inlet of the No. 2 heat exchanger (8), the air outlet of the No. 2 heat exchanger (8) is connected to the air inlet of the air expander (9), and the air expander (9) is connected to the No. 2 generator ( 10) In series. 2. A compressed air energy storage system coupled with a coal-fired cogeneration unit according to claim 1, wherein the turbine system generates electricity generated by the No. 1 generator (4) during the grid load trough period The surplus electric energy is used for the air compressor (5) to compress the air, and the compressed air is stored in the air storage tank (7). 3. A compressed air energy storage system coupled with a coal-fired cogeneration unit according to claim 1, wherein the network heating system makes the extraction steam from the low-pressure cylinder connecting pipe of the steam turbine pass through the three The No. 1 heat exchanger (11) heats the return water of the heating network, and the high-temperature compressed gas compressed by the air compressor (5) passes through the No. 1 heat exchanger (6) to heat the return water of the heating network for heating. 4. A compressed air energy storage system coupled with a coal-fired cogeneration unit according to claim 1, wherein the compressed air energy storage system absorbs excess electric energy produced by a steam turbine system during a grid load trough period , the air is compressed by the air compressor (5) and then enters the air storage tank (7), and the air storage tank (7) releases the compressed air during the peak load period of the grid, and absorbs the high pressure from the steam turbine through the No. 2 heat exchanger (8). The heat of the extraction steam at the last stage of the cylinder enters the air expander (9) to do work, and drives the No. 2 generator (10) to generate electricity.

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