Anti-freezing system and method for dry-wet combined cooling tower of compressed air energy storage project

Abstract

The invention discloses an anti-freezing system and method for a dry-wet combined cooling tower in a compressed air energy storage project, and belongs to the field of compressed air energy storage. The anti-freezing system comprises a circulating water system composed of an auxiliary machine heat exchanger, a circulating water pump in a circulating water pump room, a high-level water tank, the dry-wet combined cooling tower, an underground water storage tank, a water filling pump, connecting pipelines and a control system; an ultralow-temperature air source heat pump unit which is communicated with the circulating water system and is used for heating circulating water is arranged in the circulating water pump room; and a plurality of remote thermometers and a plurality of valves are arranged on each connecting pipeline. During shutdown of the compressed air energy storage power station and water filling in winter, the ultralow-temperature air source heat pump is used for heating circulating water, freezing of the dry-wet combined cooling tower is avoided, the running mode of the dry-wet combined cooling tower is matched with the running mode of a main engine, frequent water filling and discharging of the cooling tower are avoided, and the cooling efficiency is improved. The anti-freezing problem in the shutdown period of the dry-wet combined cooling tower of the compressed air energy storage power station is solved, the operation and running difficulty is reduced, and the running efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and in particular to an antifreeze system and method for a dry-wet combined cooling tower of a compressed air energy storage project. Background Art

[0002] With the rapid economic development and in-depth technological research and development in my country, the efficiency of compressed air energy storage systems has been continuously improved. Compressed air energy storage power stations have the characteristics of large capacity, short construction period, long life, strong integration with other technologies, flexible site selection, safety and environmental protection, so compressed air energy storage power stations have been promoted. As a water-saving cold end, the dry-wet combined cooling tower has been widely used in compressed air storage power stations in Northwest my country.

[0003] Compared with the continuous operation of thermal power plants, the operation of compressed air energy storage power stations is divided into two operating conditions: energy storage and power generation, and they operate intermittently and alternately, which brings about the problem of cooling tower antifreeze. Traditional dry-wet combined cooling tower antifreeze basically adopts three methods: variable frequency fans, shutters installed at the air inlet, and emergency water discharge system.

[0004] Since the compressed air energy storage power station operates in intervals and the interruption time is uncertain, variable frequency fans and the installation of shutters cannot achieve a good anti-freeze effect; the emergency waterproofing system can achieve a good anti-freeze effect, but the dry-wet combined cooling tower is frequently filled and discharged, the operation is complicated, and it leads to operational difficulties.

[0005] In view of this, it is necessary to provide an antifreeze system and method for a dry-wet combined cooling tower for a compressed air energy storage project to solve the above problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an antifreeze system and method for a dry-wet combined cooling tower of a compressed air energy storage power station. During the shutdown of the compressed air energy storage power station and the water filling in winter, an ultra-low temperature air source heat pump is used to heat the circulating water to prevent the dry-wet combined cooling tower from freezing. This can solve the problem of water antifreeze in the dry-wet combined cooling tower during the shutdown of the energy storage power station, avoid frequent water filling and discharge of the system, reduce the difficulty of operation, and improve the operating efficiency.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: An antifreeze system for a dry-wet combined cooling tower of a compressed air energy storage project includes a circulating water system consisting of an auxiliary heat exchanger, a circulating water pump arranged in a circulating water pump room, a high-level water tank, a dry-wet combined cooling tower, an underground water storage tank, a water filling pump arranged in the underground water storage tank, various connecting pipes and a control system. An ultra-low temperature air source heat pump unit connected to the circulating water system and capable of heating circulating water is arranged in the circulating water pump room; and a plurality of remote thermometers and a plurality of valves are arranged on each connecting pipe.

[0008] A further improvement of the technical solution of the present invention is that: the dry-wet combined cooling tower comprises a dry section and a wet section arranged in series; the water outlet end of the dry section is connected to the water inlet end of the wet section; the water inlet end of the dry section is connected to the water outlet end of the ultra-low temperature air source heat pump unit; the water outlet end of the wet section is connected to the circulating water pump; a first bypass is also provided at the water outlet end of the dry section and is connected to the circulating water pump; a seventh valve is provided on the first bypass; an eighth valve and a tenth valve are respectively provided at the two water inlet ends of the wet section; a ninth valve and an eleventh valve are respectively provided at the two water outlet ends of the wet section; the outlet water of the dry section and the wet section is also connected to the underground water tank through a second bypass, and a twelfth valve is provided on the second bypass.

[0009] A further improvement of the technical solution of the present invention is that the water outlet of the ultra-low temperature air source heat pump unit is also connected to the underground water tank through a third bypass; a thirteenth valve is arranged on the third bypass; the water in the underground water tank is replenished to the circulating water system and the ultra-low temperature air source heat pump unit through a water filling pump.

[0010] A further improvement of the technical solution of the present invention is that a third remote thermometer, a third valve, a fifth valve, a sixth valve, a first remote thermometer, a second valve, a second remote thermometer and a first valve are arranged on the circulation loop connecting the ultra-low temperature air source heat pump unit and the circulating water system; the first valve is arranged on the fourth bypass connecting the water outlet and the return water end of the ultra-low temperature air source heat pump unit; the first remote thermometer is arranged at the water inlet end of the circulating water pump; the second remote thermometer is arranged at the return water end of the ultra-low temperature air source heat pump unit, and the second valve is arranged at the front end of the second remote thermometer; the third remote thermometer is arranged at the water outlet end of the ultra-low temperature air source heat pump unit, and the third valve is arranged at the rear end of the third remote thermometer.

[0011] A further improvement of the technical solution of the present invention is that a fourth remote thermometer is provided at the water outlet of the water filling pump, and a fourth valve is provided on the water supply pipe connecting the water filling pump and the ultra-low temperature air source heat pump unit.

[0012] A further improvement of the technical solution of the present invention is that the selection of the ultra-low temperature air source heat pump in the ultra-low temperature air source heat pump unit is determined by calculation based on external meteorological conditions, circulating water volume, circulating water temperature rise and heat exchange efficiency, and the number of air source heat pumps is not less than 2 and is not used alone.

[0013] An operating method of an antifreeze system for a dry-wet combined cooling tower of a compressed air energy storage project, comprising the following contents: During the winter operation of the compressed air energy storage power station, due to the low temperature, the dry-wet combined cooling tower only operates in the dry section. At this time, the eighth valve and the tenth valve at the water inlet end of the wet section and the ninth valve and the eleventh valve at the water outlet end are closed, and the seventh valve on the first bypass is opened at the same time; During the winter shutdown period, close the air inlet shutters and cooling tower fans of the dry section of the dry-wet combined cooling tower, operate the circulating water pump with variable frequency, maintain the circulating water flow rate at 20%-40% of the normal flow rate, and at the same time close the first valve, open the second valve and the third valve. When the temperature at the first remote thermometer or the second remote thermometer drops to 8°C, start the ultra-low temperature air source heat pump unit, and use the ultra-low temperature air source heat pump unit to supplement heat for the circulating water system. When the temperature at the third remote thermometer rises to 30-35°C, the ultra-low temperature air source heat pump unit stops running, while keeping the circulating water pump running continuously; During winter maintenance, open the twelfth and thirteenth valves to drain the water in the entire antifreeze system to the underground water tank; When the dry-wet combined cooling tower is filled with water in winter, if the temperature at the fourth remote thermometer is higher than 18°C, the fourth valve is closed, the fifth valve and the sixth valve are opened, and the water in the underground water tank directly enters the dry-wet combined cooling tower; if the temperature at the fourth remote thermometer is lower than 18°C, the second valve, the fifth valve and the sixth valve are closed, the fourth valve and the third valve are opened, and the ultra-low temperature air source heat pump unit is started, and the water in the underground water tank is heated to 18°C ​​by the ultra-low temperature air source heat pump unit and then enters the dry-wet combined cooling tower.

[0014] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is: 1. During the shutdown of the compressed air energy storage power station and the water filling in winter, the present invention utilizes an ultra-low temperature air source heat pump to heat the circulating water to avoid the freezing of the dry-wet combined cooling tower, so that the operation mode of the dry-wet combined cooling tower is consistent with the operation mode of the main engine (compression condition, energy storage condition, intermittent alternating operation), thereby solving the anti-freezing problem of the dry-wet combined cooling tower of the compressed air energy storage power station during the shutdown period, avoiding frequent filling and discharging of the cooling tower, reducing the difficulty of operation, reducing the difficulty of operation, and improving the operation efficiency.

[0015] 2. The present invention is energy-efficient, safe and reliable; easy to construct and install, easy to operate; convenient to maintain, stable in operation; economical and applicable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. Figure 1 It is a structural schematic diagram of an antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project provided in an embodiment of the present invention; Among them, 1. Ultra-low temperature air source heat pump unit; 2. Auxiliary machine heat exchanger; 3. Circulating water pump; 4. High-level water tank; 5. Dry section; 6. Wet section; 7. Filling pump; 8. First remote thermometer; 9. Second remote thermometer; 10. Third remote thermometer; 11. Fourth remote thermometer; 12. First valve; 13. Second valve; 14. Third valve; 15. Fourth valve; 16. Fifth valve; 17. Sixth valve; 18. Seventh valve; 19. Eighth valve; 20. Ninth valve; 21. Tenth valve; 22. Eleventh valve; 23. Twelfth valve; 24. Thirteenth valve. DETAILED DESCRIPTION

[0017] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0018] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "several" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0020] The present invention is further described in detail below with reference to the accompanying drawings and embodiments: like Figure 1As shown, an antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project includes a circulating water system consisting of an auxiliary heat exchanger 2, a circulating water pump 3 arranged in a circulating water pump room, a high-level water tank 4, a dry-wet combined cooling tower, an underground water storage tank, a water filling pump 7 arranged in the underground water storage tank, various connecting pipes and a control system. An ultra-low temperature air source heat pump unit 1 connected to the circulating water system and capable of heating the circulating water is arranged in the circulating water pump room; a plurality of remote thermometers and a plurality of valves are arranged on each connecting pipe.

[0021] Furthermore, the dry-wet combined cooling tower includes a dry section 5 and a wet section 6 arranged in series; the outlet end of the dry section 5 is connected to the inlet end of the wet section 6; the inlet end of the dry section 5 is connected to the outlet end of the ultra-low temperature air source heat pump unit 1; the outlet end of the wet section 6 is connected to the circulating water pump 3; a first bypass is also provided at the outlet end of the dry section 5 to be connected to the circulating water pump 3; a seventh valve 18 is provided on the first bypass; an eighth valve 19 and a tenth valve 21 are respectively provided at the two inlet ends of the wet section 6; a ninth valve 20 and an eleventh valve 22 are respectively provided at the two outlet ends of the wet section 6; the outlet water of the dry section 5 and the wet section 6 is also connected to the underground water tank through a second bypass, and a twelfth valve 23 is provided on the second bypass.

[0022] Furthermore, the water outlet of the ultra-low temperature air source heat pump unit 1 is also connected to the underground water tank through a third bypass; a thirteenth valve 24 is arranged on the third bypass; the water in the underground water tank is replenished to the circulating water system and the ultra-low temperature air source heat pump unit 1 through a filling pump 7.

[0023] Furthermore, a third remote thermometer 10, a third valve 14, a fifth valve 16, a sixth valve 17, a first remote thermometer 8, a second valve 13, a second remote thermometer 9 and a first valve 12 are arranged on the circulation loop connecting the ultra-low temperature air source heat pump unit 1 and the circulating water system; the first valve 12 is arranged on the fourth bypass connecting the water outlet and the return water end of the ultra-low temperature air source heat pump unit 1; the first remote thermometer 8 is arranged at the water inlet end of the circulating water pump 3; the second remote thermometer 9 is arranged at the return water end of the ultra-low temperature air source heat pump unit 1, and the second valve 13 is arranged at the front end of the second remote thermometer 9; the third remote thermometer 10 is arranged at the water outlet end of the ultra-low temperature air source heat pump unit 1, and the third valve 14 is arranged at the rear end of the third remote thermometer 10.

[0024] Furthermore, a fourth remote thermometer 11 is provided at the water outlet of the water filling pump 7 , and a fourth valve 15 is provided on the water supply pipe connecting the water filling pump 7 and the ultra-low temperature air source heat pump unit 1 .

[0025] Furthermore, the selection of the ultra-low temperature air source heat pump in the ultra-low temperature air source heat pump unit 1 is determined by calculation based on external meteorological conditions, circulating water volume, circulating water temperature rise and heat exchange efficiency. The number of air source heat pumps is not less than 2 and is not used alone.

[0026] An operation method of an antifreeze system for a dry-wet combined cooling tower of a compressed air energy storage project, comprising the following contents: During the winter operation of the compressed air energy storage power station, due to the low temperature, only the dry section 5 of the dry-wet combined cooling tower is in operation. At this time, the eighth valve 19 and the tenth valve 21 at the water inlet end of the wet section 6 and the ninth valve 20 and the eleventh valve 22 at the water outlet end are closed, and the seventh valve 18 on the first bypass is opened at the same time; During the winter shutdown period, the air inlet shutters and cooling tower fans of the dry section 5 of the dry-wet combined cooling tower are closed, the circulating water pump 3 is operated at variable frequency, and the circulating water flow rate is maintained at 20%-40% (adjustable) of the normal flow rate. At the same time, the first valve 12 is closed, and the second valve 13 and the third valve 14 are opened. When the temperature at the first remote thermometer 8 or the second remote thermometer 9 drops to 8°C (adjustable), the ultra-low temperature air source heat pump unit 1 is started, and the ultra-low temperature air source heat pump unit 1 is used to supplement heat for the circulating water system. When the temperature at the third remote thermometer 10 rises to 30-35°C (adjustable), the ultra-low temperature air source heat pump unit 1 stops running, while the circulating water pump 3 is kept running continuously; During winter maintenance, open the twelfth valve 23 and the thirteenth valve 24 to drain the water in the entire antifreeze system to the underground water tank; When the dry-wet combined cooling tower is filled with water in winter, if the temperature at the fourth remote thermometer 11 is higher than 18°C, the fourth valve 15 is closed, the fifth valve 16 and the sixth valve 17 are opened, and the water in the underground water tank directly enters the dry-wet combined cooling tower; if the temperature at the fourth remote thermometer 11 is lower than 18°C ​​(adjustable), the second valve 13, the fifth valve 16 and the sixth valve 17 are closed, the fourth valve 15 and the third valve 14 are opened, and the ultra-low temperature air source heat pump unit 1 is started, and the water in the underground water tank is heated to 18°C ​​(adjustable) by the ultra-low temperature air source heat pump unit 1 and then enters the dry-wet combined cooling tower.

[0027] Figure 1 Only the key systems and valves are marked in the figure. Taking the split dry-wet combined cooling tower as an example, the principle of the integrated dry-wet cooling tower is the same and will not be repeated here.

[0028] In summary, the present invention utilizes an ultra-low temperature air source heat pump to heat circulating water during the shutdown of the compressed air energy storage power station and the water filling in winter, thereby avoiding the freezing of the dry-wet combined cooling tower and making the operation mode of the dry-wet combined cooling tower consistent with the operation mode of the main engine (compression condition, energy storage condition, intermittent alternating operation).

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An antifreeze system for a dry-wet combined cooling tower of a compressed air energy storage project, comprising a circulating water system consisting of an auxiliary heat exchanger (2), a circulating water pump (3) arranged in a circulating water pump room, a high-level water tank (4), a dry-wet combined cooling tower, an underground water storage tank, a water filling pump (7) arranged in the underground water storage tank, various connecting pipes and a control system, characterized in that: An ultra-low temperature air source heat pump unit (1) connected to the circulating water system and capable of heating circulating water is arranged in the circulating water pump room; and a plurality of remote thermometers and a plurality of valves are arranged on each connecting pipeline.

2. The antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project according to claim 1, characterized in that: The dry-wet combined cooling tower comprises a dry section (5) and a wet section (6) which are arranged in series; the water outlet end of the dry section (5) is connected to the water inlet end of the wet section (6); the water inlet end of the dry section (5) is connected to the water outlet end of the ultra-low temperature air source heat pump unit (1); the water outlet end of the wet section (6) is connected to the circulating water pump (3); a first bypass is also provided at the water outlet end of the dry section (5) and is connected to the circulating water pump (3); a seventh valve (18) is provided on the first bypass; an eighth valve (19) and a tenth valve (21) are respectively provided at the two water inlet ends of the wet section (6); a ninth valve (20) and an eleventh valve (22) are respectively provided at the two water outlet ends of the wet section (6); the outlet water of the dry section (5) and the wet section (6) is also connected to the underground water storage tank through a second bypass, and a twelfth valve (23) is provided on the second bypass.

3. The antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project according to claim 1, characterized in that: The water outlet of the ultra-low temperature air source heat pump unit (1) is also connected to the underground water storage tank via a third bypass; a thirteenth valve (24) is provided on the third bypass; and the water in the underground water storage tank is supplied to the circulating water system and the ultra-low temperature air source heat pump unit (1) via a water filling pump (7).

4. The antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project according to claim 3, characterized in that: A third remote thermometer (10), a third valve (14), a fifth valve (16), a sixth valve (17), a first remote thermometer (8), a second valve (13), a second remote thermometer (9) and a first valve (12) are arranged on a circulation loop connecting the ultra-low temperature air source heat pump unit (1) and the circulating water system; the first valve (12) is arranged on a fourth bypass connecting the water outlet and the return water end of the ultra-low temperature air source heat pump unit (1); the first remote thermometer (8) is arranged at the water inlet of the circulating water pump (3); the second remote thermometer (9) is arranged at the return water end of the ultra-low temperature air source heat pump unit (1), and the second valve (13) is arranged at the front end of the second remote thermometer (9); the third remote thermometer (10) is arranged at the water outlet of the ultra-low temperature air source heat pump unit (1), and the third valve (14) is arranged at the rear end of the third remote thermometer (10).

5. The antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project according to claim 3, characterized in that: A fourth remote thermometer (11) is provided at the water outlet of the water filling pump (7), and a fourth valve (15) is provided on the water supply pipeline connecting the water filling pump (7) and the ultra-low temperature air source heat pump unit (1).

6. The antifreeze system for a dry-wet combined cooling tower for a compressed air energy storage project according to claim 1, characterized in that: The selection of the ultra-low temperature air source heat pump in the ultra-low temperature air source heat pump unit (1) is determined by calculation based on external meteorological conditions, circulating water volume, circulating water temperature rise and heat exchange efficiency. The number of air source heat pumps is not less than 2 and is not reserved.

7. An operating method of an antifreeze system for a dry-wet combined cooling tower of a compressed air energy storage project according to any one of claims 1 to 6, characterized in that: Includes the following: During the winter operation of the compressed air energy storage power station, due to the low temperature, only the dry section (5) of the dry-wet combined cooling tower is operated. At this time, the eighth valve (19) and the tenth valve (21) at the water inlet end of the wet section (6) and the ninth valve (20) and the eleventh valve (22) at the water outlet end are closed, and the seventh valve (18) on the first bypass is opened at the same time; During the winter shutdown period, the air inlet shutters and cooling tower fans of the dry section (5) of the dry-wet combined cooling tower are closed, the circulating water pump (3) is operated at variable frequency, and the circulating water flow rate is maintained at 20%-40% of the normal flow rate. At the same time, the first valve (12) is closed, and the second valve (13) and the third valve (14) are opened. When the temperature at the first remote thermometer (8) or the second remote thermometer (9) drops to 8°C, the ultra-low temperature air source heat pump unit (1) is started, and the ultra-low temperature air source heat pump unit (1) is used to supplement heat for the circulating water system. When the temperature at the third remote thermometer (10) rises to 30-35°C, the ultra-low temperature air source heat pump unit (1) stops running, while the circulating water pump (3) is kept running continuously; During winter maintenance, the twelfth valve (23) and the thirteenth valve (24) are opened to drain the water in the entire antifreeze system to the underground water storage tank; When the dry-wet combined cooling tower is filled with water in winter, if the temperature at the fourth remote thermometer (11) is higher than 18°C, the fourth valve (15) is closed, the fifth valve (16) and the sixth valve (17) are opened, and the water in the underground water storage tank directly enters the dry-wet combined cooling tower; if the temperature at the fourth remote thermometer (11) is lower than 18°C, the second valve (13), the fifth valve (16) and the sixth valve (17) are closed, the fourth valve (15) and the third valve (14) are opened, and the ultra-low temperature air source heat pump unit (1) is started, and the water in the underground water storage tank is heated to 18°C ​​by the ultra-low temperature air source heat pump unit (1) and then enters the dry-wet combined cooling tower.

Images