System and method for reducing spray water discharge capacity of dry-wet combined cooling tower of compressed air energy storage power station

Abstract

The invention discloses a system and a method for reducing spray water discharge capacity of a dry-wet combined cooling tower of a compressed air energy storage power station, and belongs to the field of compressed air energy storage. Comprising a spraying water tank, a spraying pipeline arranged between the spraying water tank and a sprayer in the dry-wet combined cooling tower, a spraying water supply pipeline connected with the spraying water tank and a pollution discharge water supply loop connected with the spraying water tank, the pollution discharge and water supply loop comprises a first branch led out from a pollution discharge port of the spraying water tank, a chemical water treatment dosing device connected with the first branch, and a third branch connected with the chemical water treatment dosing device and a water adding port of the spraying water tank; a second branch is arranged on the first branch in parallel; a blowdown tank is arranged on the second branch; and the chemical water treatment dosing device is connected with the demineralized water supply pipeline. A demineralized water replenishing loop is additionally arranged in a conventional spray water replenishing system of the dry-wet combined cooling tower, and in the high-temperature weather in summer, the concentration ratio of spray water is increased through self circulation, and the discharge capacity is reduced.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage, and in particular to a system and method for reducing the amount of wastewater discharged from the spraying water of a combined dry and wet cooling tower in a compressed air energy storage power station. Background Technology

[0002] In recent years, compressed air energy storage technology has been rapidly applied and developed. In conventional compressed air energy storage systems, cooling towers are typically used to release the heat generated by the main and auxiliary units. Combined dry and wet cooling towers integrate the advantages of both dry and wet cooling towers, reducing costs, saving water resources, and improving thermal efficiency.

[0003] In typical compressed air energy storage (CASP) or compressed carbon dioxide (CCCO) energy storage power plants, summer temperatures are generally stable with minimal extreme heat, resulting in minimal fluctuations in cooling tower spray water discharge and relatively stable output of chemical water treatment equipment. Furthermore, the wastewater treatment capacity within CASP is limited due to the small volume of wastewater requiring treatment. However, with advancements in CASP technology, such as the integration of refrigeration systems into power plants, the capacity and number of cooling towers have significantly increased, leading to a substantial rise in spray water discharge.

[0004] In compressed air energy storage power stations, when outdoor temperatures are not high, the wastewater discharge from the cooling tower is relatively small, and the output of the chemical water treatment equipment is also relatively low. However, when outdoor temperatures are high or even extremely high, the wastewater discharge from the cooling tower can increase exponentially in a short period of time. Selecting chemical water treatment equipment based on these extreme conditions is clearly uneconomical and unreasonable.

[0005] Without appropriate measures, the capacity of chemical treatment equipment would increase exponentially, raising the investment in power plants. Furthermore, many power plants are built in areas where extreme temperatures occasionally occur in summer; selecting chemical water treatment equipment based on these extreme conditions would clearly be uneconomical. Reducing the amount of wastewater discharged from combined wet and dry cooling towers at the source could decrease the output of chemical water treatment systems, thereby reducing the need for related chemical equipment.

[0006] Therefore, considering the current operating mode of dry and wet combined cooling towers in compressed air energy storage power plants and the large amount of wastewater discharged from these towers, it is necessary to develop a system and method to reduce the wastewater discharge from dry and wet combined cooling towers in compressed air energy storage power plants. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a system and method for reducing the amount of wastewater discharged from the spray water of the dry-wet combined cooling tower in a compressed air energy storage power station. By adding a demineralized water replenishment loop to the conventional dry-wet combined cooling tower spray water replenishment system, the system can increase the concentration ratio of the spray water during hot summer weather, reduce the amount of wastewater discharged, reduce the configuration of chemical water treatment devices, enhance the self-regulating ability of the cooling tower to discharge wastewater, reduce initial investment, reduce operating costs, and reduce energy consumption.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0009] A system for reducing the amount of wastewater discharged from a combined dry and wet cooling tower in a compressed air energy storage power station includes a spray pool, a spray pipeline between the spray pool and the sprayers in the combined dry and wet cooling tower, a spray water supply pipeline connected to the spray pool, and a wastewater supply circuit connected to the spray pool.

[0010] The sewage discharge and water supply circuit includes a first branch leading out from the sewage outlet of the spray pool, a chemical water treatment dosing device connected to the first branch, and a third branch connecting the chemical water treatment dosing device to the water inlet of the spray pool; a second branch is connected in parallel to the first branch; a sewage discharge box is installed on the second branch; and the chemical water treatment dosing device is connected to the demineralized water supply pipeline.

[0011] A further improvement to the technical solution of the present invention is that a spray water pump is installed on the spray pipeline.

[0012] A further improvement of the technical solution of the present invention is that a first valve V1 is provided on the spray water supply pipeline.

[0013] A further improvement to the technical solution of the present invention is that a first sewage pump and a second valve V2 are provided on the first branch.

[0014] A further improvement to the technical solution of the present invention is that a third valve V3 is installed on the demineralized water supply pipeline.

[0015] A further improvement to the technical solution of the present invention is that a fourth valve V4 is provided on the third branch.

[0016] A further improvement to the technical solution of the present invention is that: a fifth valve V5, a sewage tank, and a second sewage pump are sequentially installed on the second branch.

[0017] A method for reducing the wastewater discharge from a combined dry and wet cooling tower in a compressed air energy storage power station includes the following steps:

[0018] S1. Determine the temperature range. If the temperature is lower than the preset value, execute S2. If the temperature is higher than the preset value, execute S3.

[0019] S2. Start the normal water replenishment and sewage discharge procedure, turn on the spray water pump, the first sewage pump, the first valve V1, the second valve V2 and the third valve V3, and close the second sewage pump, the fourth valve V4 and the fifth valve V5. Tap water is used as the water source for spray water and enters the spray water pool of the dry and wet combined cooling tower through the spray water supply pipeline. The spray water pump provides spray water to the dry and wet combined cooling tower. The sewage generated after spraying is discharged into the chemical water treatment dosing device through the first sewage pump. The demineralized water generated is used by other process systems in the station.

[0020] S3. Start the water treatment process, turn on the spray pump, the first sewage pump, the second sewage pump, the first valve V1, the second valve V2, the third valve V3, the fourth valve V4 and the fifth valve V5. Part of the sewage will enter the sewage tank for buffering and storage, and part of the sewage will be discharged into the chemical water treatment dosing device.

[0021] A further improvement to the technical solution of the present invention is that S3 specifically includes the following steps:

[0022] S31 opens the second valve V2 to the fully open state, and the fifth valve V5 opens to the opening degree of the second valve V2.

[0023] S32 The second sewage pump is shut off until the temperature T drops below the preset value Ta. Then, the fifth valve V5 is closed, and the second sewage pump is opened to the same degree as the first sewage pump. The wastewater in the wastewater tank is pumped into the water treatment dosing device via the second wastewater pump.

[0024] The demineralized water generated by S33 enters the spray water tank through the fourth valve V4 and mixes with tap water to provide spray water for the cooling tower.

[0025] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0026] 1. Because compressed air energy storage power plants are much smaller in scale than comparable thermal power plants, and their operation is discontinuous, the scale of the chemical water treatment system in a compressed air energy storage power plant is usually much smaller than that in a thermal power plant, and its treatment capacity is also very limited. It is clearly uneconomical and unreasonable to increase the scale of the plant's chemical water treatment system simply for the cooling tower; therefore, the cooling tower's spray water system needs to have strong self-treatment capabilities. This invention, through the comprehensive utilization of wastewater tanks, chemical water treatment dosing devices, and other equipment and pipelines installed in the dry-wet combined cooling tower spray water system of a compressed air energy storage power plant, can reduce the amount of wastewater discharged from the dry-wet combined cooling tower.

[0027] 2. This invention, through the comprehensive utilization of equipment and pipelines such as the wastewater discharge tank, chemical water treatment dosing device, etc., installed in the dry and wet combined cooling tower spray water system of the compressed air energy storage power station, can help reduce the output of the chemical water treatment system in the power station and reduce energy consumption.

[0028] 3. By comprehensively utilizing equipment and pipelines such as the wastewater tank, chemical water treatment dosing device, etc., set in the dry and wet combined cooling tower spray water system of the compressed air energy storage power station, the present invention can enable the dry and wet combined cooling tower spray water system of the compressed air energy storage power station to have a certain self-regulating capability.

[0029] 4. Under extreme high temperature conditions, the sewage discharge volume is large. The sewage discharge tank participates in the sewage treatment process, which improves the quality of the spray water, increases the concentration ratio, and reduces the sewage discharge volume. This circulation and pipeline can also be operated under normal conditions, which helps to reduce the output of the chemical water treatment system in the power plant, reduce energy consumption, enhance the self-regulation capability of this system and the regulation capability of the chemical water treatment system in the power plant. The configuration of the chemical water treatment system in the power plant can also be reduced accordingly, saving initial investment and operating costs.

[0030] 5. If the present invention is designed and applied reasonably, the configuration of the chemical water treatment system in the power plant can be reduced accordingly, saving initial investment and operating costs. Attached Figure Description

[0031] Figure 1 This is a flowchart of a system for reducing the amount of wastewater discharged from the dry and wet combined cooling tower of a compressed air energy storage power station, as described in this invention.

[0032] Among them, 1. Spray water pump, 2. First sewage pump, 3. Sewage tank, 4. Second sewage pump, 5. Chemical water treatment dosing device, 6. Combined dry and wet cooling tower, and 7. Spray water pool. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0034] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0035] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include at least one of that feature. In the description of this invention, "a number" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0036] like Figure 1 As shown, a system for reducing the amount of wastewater discharged from the dry and wet combined cooling tower of a compressed air energy storage power station includes a spray water tank 7, a spray pipeline between the spray water tank 7 and the sprayers in the dry and wet combined cooling tower 6, a spray water supply pipeline connected to the spray water tank 7, and a wastewater supply circuit connected to the spray water tank 7.

[0037] A spray water pump 1 is installed on the spray pipeline;

[0038] A first valve V1 is installed on the spray water supply pipeline;

[0039] The sewage discharge and water supply circuit includes a first branch leading out from the sewage outlet of the spray pool 7, a chemical water treatment dosing device 5 connected to the first branch, and a third branch connecting the chemical water treatment dosing device 5 to the water inlet of the spray pool 7; a second branch is connected in parallel to the first branch; the chemical water treatment dosing device 5 is connected to the demineralized water supply pipeline.

[0040] A first sewage pump 2 and a second valve V2 are installed on the first branch.

[0041] The second branch is equipped with the fifth valve V5, a sewage tank, and the second sewage pump 4 in sequence;

[0042] A fourth valve, V4, is installed on the third branch.

[0043] A third valve V3 is installed on the demineralized water supply pipeline.

[0044] A method for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station includes the following steps:

[0045] S1. Determine the temperature range. When the temperature T is lower than the preset value Ta, execute S2. When the temperature T is higher than the preset value Ta, execute S3. Ta is generally set to 30 degrees.

[0046] S2. Start the normal water replenishment and sewage discharge procedure, turn on spray water pump 1, first sewage pump 2, first valve V1, second valve V2 and third valve V3, and close second sewage pump 4, fourth valve V4 and fifth valve V5. Tap water is used as the water source for spray water and enters the spray water pool 7 of dry and wet combined cooling tower 6 through the spray water supply pipeline. Spray water pump 1 provides spray water to dry and wet combined cooling tower 6. The sewage generated after spraying is discharged into the chemical water treatment dosing device 5 through the first sewage pump 2. The demineralized water generated is used by other process systems in the station.

[0047] S3. Start the water treatment process, turn on the spray pump 1, the first sewage pump 2, the first valve V1, the second valve V2, the third valve V3 and the fourth valve V4. Part of the sewage enters the sewage tank 3 for buffering and storage, and part of the sewage is discharged into the chemical water treatment dosing device 5.

[0048] S31 opens the second valve V2 to the fully open state, and the fifth valve V5 opens to the opening degree of the second valve V2.

[0049] S32 Second sewage pump 4 is shut off until the temperature T drops below the preset value Ta, then the fifth valve V5 is closed, and the second sewage pump 4 is opened to the same degree as the first sewage pump 2. The sewage in sewage tank 3 is pumped into the water treatment dosing device via the second sewage pump 4.

[0050] The demineralized water generated by S33 enters the spray water tank 7 through the fourth valve V4 and mixes with tap water to provide spray water for the cooling tower.

[0051] In summary, this invention, by adding a demineralized water replenishment loop to the conventional wet-dry combined cooling tower spray water replenishment system, increases the spray water concentration ratio, reduces sewage discharge, reduces the configuration of chemical water treatment devices, enhances the self-regulating ability of cooling tower sewage discharge, reduces initial investment, lowers operating costs, and reduces energy consumption during hot summer weather by utilizing its own circulation.

Claims

1. A system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station, characterized in that: It includes a spray pool (7), a spray pipeline between the sprayers installed in the spray pool (7) and the dry and wet combined cooling tower (6), a spray water supply pipeline connected to the spray pool (7), and a sewage supply circuit connected to the spray pool (7). The sewage discharge and water supply circuit includes a first branch leading out from the sewage outlet of the spray pool (7), a chemical water treatment dosing device (5) connected to the first branch, and a third branch connecting the chemical water treatment dosing device (5) to the water inlet of the spray pool (7); a second branch is set in parallel on the first branch; a sewage discharge box is set on the second branch; the chemical water treatment dosing device (5) is connected to the demineralized water supply pipeline.

2. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: A spray water pump (1) is installed on the spray pipeline.

3. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: A first valve V1 is installed on the spray water supply pipeline.

4. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: A first sewage pump (2) and a second valve V2 are installed on the first branch.

5. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: A third valve V3 is installed on the demineralized water supply pipeline.

6. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: A fourth valve, V4, is installed on the third branch.

7. The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 1, characterized in that: The second branch is equipped with the fifth valve V5, the sewage tank, and the second sewage pump (4) in sequence.

8. A method for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station, characterized in that: The system for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station as described in any one of claims 1 to 7 includes the following steps: S1. Determine the temperature range. If the temperature is lower than the preset value, execute S2. If the temperature is higher than the preset value, execute S3. S2. Start the normal water replenishment and sewage discharge procedure, turn on the spray water pump (1), the first sewage pump (2), the first valve V1, the second valve V2 and the third valve V3, and close the second sewage pump (4), the fourth valve V4 and the fifth valve V5. Tap water is used as the water source for spray water and enters the spray water pool (7) of the dry and wet combined cooling tower (6) through the spray water supply pipeline. Spray water is provided to the dry and wet combined cooling tower (6) by the spray water pump (1). The sewage generated after spraying is discharged into the chemical water treatment dosing device (5) through the first sewage pump (2). The demineralized water generated is used by other process systems in the station. S3. Start the water treatment process, turn on the spray pump (1), the first sewage pump (2), the second sewage pump (4), the first valve V1, the second valve V2, the third valve V3, the fourth valve V4 and the fifth valve V5. Part of the sewage enters the sewage tank (3) for buffering and storage, and part of the sewage is discharged into the chemical water treatment dosing device (5).

9. The method for reducing the amount of wastewater discharged from the combined dry and wet cooling tower of a compressed air energy storage power station according to claim 8, characterized in that: S3 specifically includes the following steps: S31 opens the second valve V2 to the fully open state, and the fifth valve V5 opens to the opening degree of the second valve V2. S32 Second sewage pump (4) is shut off until the temperature T drops below the preset value Ta. Then, the fifth valve V5 is closed, and the opening of the second sewage pump (4) is increased to the opening of the first sewage pump (2). The sewage in the sewage tank (3) is pumped into the water treatment dosing device via the second sewage pump (4); The demineralized water generated by S33 enters the spray water pool (7) through the fourth valve V4 and mixes with tap water to provide spray water for the cooling tower.

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