A cooling device for an electrical control cabinet for a sewage treatment plant and a method of using the same

Abstract

The present invention discloses a cooling device for an electrical control cabinet for a sewage treatment plant and a method for using the same. The device comprises an electrical control cabinet, a first heat dissipation device and a second heat dissipation device. The second heat dissipation device is located in a sewage treatment pool, the first heat dissipation device is located in the electrical control cabinet, a fan is also provided in the electrical control cabinet, a pipeline is provided in the first heat dissipation device, one end of the pipeline in the first heat dissipation device is connected to a first cooling pipeline, and the other end is connected to a seventh cooling pipeline. The present invention utilizes sewage from the sewage treatment plant to perform heat exchange on the first cooling medium, thereby achieving a single cooling effect; the condenser provided can perform heat exchange on the first refrigeration circuit and the second refrigeration circuit, thereby achieving a double cooling effect; the fan achieves a triple cooling effect, thereby greatly improving the cooling effect on the electrical control cabinet, improving the operational reliability of the electrical control cabinet, and being energy-saving and environmentally friendly, thereby greatly reducing the cooling cost, and realizing wastewater utilization.

Description

Technical Field

[0001] The invention relates to a cooling device for an electrical control cabinet for a sewage plant and a use method thereof, belonging to the technical field of electrical control cabinets. Background Art

[0002] During the installation of electrical equipment in sewage treatment plants, many electrical control cabinets are required to be installed near the electrical equipment. Most electrical control cabinets are installed outdoors. With the arrival of summer, the temperature inside the electrical control cabinets becomes abnormal due to long-term exposure to the sun, affecting their normal use.

[0003] There are two conventional cooling methods for electrical control cabinets: one is to add a cooling fan to inhale air from the outside and discharge the air inside the cabinet from the cabinet door or the shutters on both sides of the cabinet. Due to the high outdoor temperature in summer, the outside air temperature is already very high, and the cooling effect of inhaling air from the outside is poor. Long-term operation will cause the filter of the cooling fan to be blocked due to dirty air, causing the cooling effect to be further reduced; the second is to add a special air conditioner for the electric cabinet to transfer the heat inside the cabinet to the outside through the air conditioner. Due to the high outdoor temperature in summer, the cooling effect of the air conditioner is poor, resulting in the temperature inside the cabinet not meeting the use requirements. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a cooling device for an electrical control cabinet for a sewage treatment plant and a method for using the same. In the use scenario of the sewage treatment plant, sewage is fully utilized as a cold source, the cooling effect is good, the temperature in the electrical control cabinet can be stabilized within the temperature range allowed for normal operation, and the operational reliability of the electrical control is improved.

[0005] The cooling device of the electrical control cabinet for a sewage treatment plant includes an electrical control cabinet, a first heat dissipation device and a second heat dissipation device, wherein the second heat dissipation device is located in a sewage treatment tank, and the first heat dissipation device is located in the electrical control cabinet. A fan is also provided in the electrical control cabinet, and a pipeline is provided in the first heat dissipation device. One end of the pipeline in the first heat dissipation device is connected to the first cooling pipeline, and the other end is connected to the seventh cooling pipeline. The first cooling pipeline is connected to one end of the second heat dissipation device, and the seventh cooling pipeline is connected to the other end of the second heat dissipation device.

[0006] In one embodiment of the present invention, the first cooling pipeline is connected to the second heat dissipation device through a fifth cooling pipeline, and a third electric valve is provided on the first cooling pipeline; the seventh cooling pipeline is connected to the second heat dissipation device through a second cooling pipeline, and a circulating pump is provided on the second cooling pipeline.

[0007] In one embodiment of the present invention, the pipelines in the first heat dissipation device include a first pipeline and a second pipeline, the first pipeline and the second pipeline are both disc-shaped pipelines, and the two disc-shaped pipelines are independent of each other and do not interfere with each other, the two ends of the first pipeline are respectively connected to the first cooling pipeline and the seventh cooling pipeline; the two ends of the second pipeline are respectively connected to the third cooling pipeline and the sixth cooling pipeline; the air outlet of the fan is directly facing the two disc-shaped pipelines in the first heat dissipation device.

[0008] In one embodiment of the present invention, a first cooling medium is arranged in the first pipeline. Under the action of a circulating pump, the first cooling medium flows from the first pipeline in the first heat dissipation device, through the seventh cooling pipeline, the second cooling pipeline, the second heat dissipation device, the fifth cooling pipeline and the first cooling pipeline, back to the first pipeline in the first heat dissipation device, forming a first refrigeration circuit. When the first cooling medium flows through the second heat dissipation device, it exchanges heat with the sewage in the sewage treatment tank, thereby reducing the temperature of the first cooling medium.

[0009] In one embodiment of the present invention, a condenser is further included, and the third cooling pipeline and the sixth cooling pipeline respectively extend into the condenser and are connected inside the condenser; a compressor is provided on the third cooling pipeline, and a thermal expansion valve is provided on the sixth cooling pipeline.

[0010] In one embodiment of the present invention, a second cooling medium is arranged in the second pipeline. The second cooling medium flows back from the second pipeline in the first heat dissipation device through the third cooling pipeline, the compressor, the condenser, the thermal expansion valve and the sixth cooling pipeline to the second pipeline in the first heat dissipation device to form a second refrigeration circuit.

[0011] In one embodiment of the present invention, a fourth cooling pipeline is further provided in the condenser, one end of the fourth cooling pipeline is connected to the second cooling pipeline, and the other end of the fourth cooling pipeline is connected to the fifth cooling pipeline, the fourth cooling pipeline is provided with a first electric valve and a second electric valve, and the seventh cooling pipeline is provided with a fourth electric valve; the first cooling medium is pressurized by a circulating pump and flows through the seventh cooling pipeline, the cooling pipeline, and the second heat dissipation device in sequence, and by opening or closing the first electric valve, the second electric valve, the third electric valve, and the fourth electric valve, the first cooling medium can be selected to enter through the cooling pipeline and reflux to the first heat dissipation device or to enter the condenser through the fourth cooling pipeline; when the first cooling medium enters the condenser, the first cooling medium and the second cooling medium after heat exchange in the second heat dissipation device exchange heat in the condenser.

[0012] The present invention also provides a method for using a cooling device for an electrical control cabinet for a sewage treatment plant, comprising the following steps:

[0013] S1. Obtaining the temperature and humidity inside the electrical control cabinet and the environment in which the electrical control cabinet is located, the temperature of the first cooling medium flowing into and out of the first heat dissipation device, the temperature of the sewage in the second heat dissipation device, and the temperature range inside the electrical control cabinet that allows normal operation;

[0014] S2, judging whether the temperature in the electrical control cabinet is within the temperature range in which the electrical control cabinet is allowed to work normally, and controlling the opening or closing of the cooling device of the electrical control cabinet;

[0015] S3. Calculate the dew point temperature inside the electrical control cabinet and the environment where the electrical control cabinet is located according to the temperature and humidity inside the electrical control cabinet and the environment where the electrical control cabinet is located;

[0016] S4. Setting a suitable cooling temperature according to the calculated dew point temperature and the temperature range inside the electrical control cabinet that is allowed to work normally, so that the cooling device of the electrical control cabinet operates according to the preset control strategy 1 or strategy 2;

[0017] S5. If the difference between the temperature in the electrical control cabinet and the sewage temperature is greater than the first set value, the electrical control cabinet cooling device operates according to a preset control strategy 1;

[0018] S6. If the difference between the temperature in the electrical control cabinet and the sewage temperature is less than or equal to the second set ceiling value, the electrical control cabinet cooling device operates according to the preset control strategy 2.

[0019] In one embodiment of the present invention, the control strategy 1 preset in S5 includes: closing the first electric valve and the second electric valve, opening the third electric valve and the fourth electric valve, starting the circulating pump, and the first cooling medium flows from the first pipeline in the first heat dissipation device through the seventh cooling pipeline, the second cooling pipeline, the second heat dissipation device, the fifth cooling pipeline and the first cooling pipeline back to the first pipeline in the first heat dissipation device; adjusting the operating frequency of the circulating pump or the opening of the third electric valve and the fourth electric valve according to the temperature change in the electrical control cabinet.

[0020] In one embodiment of the present invention, the control strategy 2 preset in S6 includes: closing the third electric valve and the fourth electric valve, opening the first electric valve and the second electric valve, starting the circulating pump, and the first cooling medium passes through the second cooling pipeline, the second heat dissipation device, the fifth cooling pipeline, the first electric valve, the condenser, the fourth cooling pipeline, and the second electric valve to return to the first refrigeration circuit; the second cooling medium passes through the third cooling pipeline through the compressor, the condenser, the thermal expansion valve, and the sixth cooling pipeline to flow back to the second heat dissipation device to form a second refrigeration circuit; wherein the first refrigeration circuit and the second refrigeration circuit can exchange heat in the condenser; and adjusting the operating frequency of the circulating pump or the opening degree of the first electric valve and the second electric valve according to the temperature change of the first cooling medium flowing in and out of the condenser.

[0021] Beneficial Effects

[0022] 1. The present invention utilizes the sewage from the sewage treatment plant to perform heat exchange on the first cooling medium, thereby achieving a cooling effect. Since the temperature of the sewage from the sewage treatment plant is stable, especially much lower than the ambient temperature in summer, the electrical control cabinet has a good cooling effect using sewage, so that the temperature inside the electrical control cabinet is stabilized within the temperature range that allows normal operation, thereby improving the operational reliability of the electrical control; and it is energy-saving and environmentally friendly, greatly reducing the cooling cost, and realizing wastewater utilization.

[0023] 2. The present invention is provided with two refrigeration circuits and multiple valves. By opening or closing the valves, the first cooling medium can be selected to enter through the cooling pipeline and flow back into the first heat dissipation device or to enter the condenser through the fourth cooling pipeline; when the first cooling medium enters the condenser, the first cooling medium after heat exchange in the second heat dissipation device exchanges heat with the second cooling medium in the condenser, further reducing the heat of the second cooling medium, further reducing the temperature of the second refrigeration circuit, and thereby enhancing the cooling effect of the electrical control cabinet.

[0024] 3. The electrical control cabinet of the present invention can be made into a sealed state to separate it from the external environment, thereby preventing dust, water vapor, etc. from entering the cabinet and improving the operating safety of the electrical control cabinet.

[0025] 4. The condenser provided in the present invention can perform heat exchange between the first refrigeration circuit and the second refrigeration circuit, thereby achieving a double cooling effect, further improving the cooling effect on the electrical control cabinet, and can effectively solve the problem of high outdoor temperature in summer and poor cooling effect of air conditioning, resulting in the temperature inside the cabinet failing to meet the use requirements.

[0026] 5. The air outlet of the fan provided in the present invention faces the two disc-shaped pipes in the first heat dissipation device. The temperature in the electrical control cabinet is evenly cooled by the fan, achieving a triple cooling effect and greatly improving the cooling effect on the electrical control cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural diagram of the cooling device for the electrical control cabinet for a sewage treatment plant in Example 1.

[0028] Figure 2 This is a structural diagram of the cooling device for the electrical control cabinet for a sewage treatment plant in Example 3.

[0029] Among them: 1. electrical control cabinet; 2. first heat dissipation device; 3. fan; 4. circulation pump; 5. second heat dissipation device; 6. first cooling pipeline; 7. second cooling pipeline; 8. third cooling pipeline; 9. fourth cooling pipeline; 10. fifth cooling pipeline; 11. sixth cooling pipeline; 12. seventh cooling pipeline; 13. compressor; 14. condenser; 15. thermal expansion valve; 16. first electric valve; 17. second electric valve; 18. third electric valve; 19. fourth electric valve. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0033] Example 1

[0034] This embodiment provides a cooling device for an electrical control cabinet for a sewage treatment plant, such as Figure 1As shown, it includes an electrical control cabinet 1, a first heat dissipation device 2 and a second heat dissipation device 5, the second heat dissipation device 5 is located in a sewage treatment tank, the first heat dissipation device 2 is located in the electrical control cabinet 1, a fan 3 is also provided in the electrical control cabinet 1, a pipeline is provided in the first heat dissipation device 2, one end of the pipeline in the first heat dissipation device 2 is connected to the first cooling pipeline 6, and the other end is connected to the seventh cooling pipeline 12, the first cooling pipeline 6 is connected to one end of the second heat dissipation device 5, and the seventh cooling pipeline 12 is connected to the other end of the second heat dissipation device 5.

[0035] Furthermore, the first cooling pipeline 6 is connected to the second heat dissipation device 5 through the fifth cooling pipeline 10, and a third electric valve 18 is provided on the first cooling pipeline 6; the seventh cooling pipeline 12 is connected to the second heat dissipation device 5 through the second cooling pipeline 7, and a circulating pump 4 is provided on the second cooling pipeline 7.

[0036] Furthermore, the pipelines in the first heat dissipation device 2 include a first pipeline and a second pipeline, both of which are disc-shaped pipelines, and the two disc-shaped pipelines are independent of each other and do not interfere with each other, and the two ends of the first pipeline are respectively connected to the first cooling pipeline 6 and the seventh cooling pipeline 12; the two ends of the second pipeline are respectively connected to the third cooling pipeline 8 and the sixth cooling pipeline 11; the air outlet of the fan 3 is directly facing the two disc-shaped pipelines in the first heat dissipation device 2, and the temperature in the electrical control cabinet 1 is evenly cooled by the fan 3.

[0037] Furthermore, a first cooling medium is arranged in the first pipeline. Under the action of the circulating pump 4, the first cooling medium flows back from the first pipeline in the first heat dissipation device 2 through the seventh cooling pipeline 12, the second cooling pipeline 7, the second heat dissipation device 5, the fifth cooling pipeline 10 and the first cooling pipeline 6 to the first pipeline in the first heat dissipation device 2, thereby forming a first refrigeration circuit. When the first cooling medium flows through the second heat dissipation device 5, it exchanges heat with the sewage in the sewage treatment tank, thereby reducing the temperature of the first cooling medium.

[0038] Furthermore, it also includes a condenser 14, and the third cooling pipeline 8 and the sixth cooling pipeline 11 extend into the condenser 14 respectively and are connected in the condenser 14; the third cooling pipeline 8 is provided with a compressor 13, and the sixth cooling pipeline 11 is provided with a thermal expansion valve 15.

[0039] Furthermore, a second cooling medium is arranged in the second pipeline, and the second cooling medium flows back from the second pipeline in the first heat dissipation device 2 through the third cooling pipeline 8, the compressor 13, the condenser 14, the thermal expansion valve 15 and the sixth cooling pipeline 11 to the second pipeline in the first heat dissipation device 2, thereby forming a second refrigeration circuit.

[0040] Further, a fourth cooling pipeline 9 is also provided in the condenser 14, one end of the fourth cooling pipeline 9 is connected to the second cooling pipeline 7, and the other end of the fourth cooling pipeline 9 is connected to the fifth cooling pipeline 10, the fourth cooling pipeline 9 is provided with a first electric valve 16 and a second electric valve 17, and the seventh cooling pipeline 12 is provided with a fourth electric valve 19; the first cooling medium is pressurized by the circulation pump 4 and flows through the seventh cooling pipeline 12, the cooling pipeline 7, and the second heat dissipation device 5 in sequence, and by opening or closing the first electric valve 16, the second electric valve 17, the third electric valve 18, and the fourth electric valve 19, the first cooling medium can be selected to enter the first heat dissipation device 2 through the cooling pipeline 6 or to enter the condenser 14 through the fourth cooling pipeline 9; when the first cooling medium enters the condenser 14, the first cooling medium after heat exchange in the second heat dissipation device 5 exchanges heat with the second cooling medium in the condenser 14, further reducing the heat of the second cooling medium, further reducing the temperature of the second refrigeration circuit, and thereby enhancing the cooling effect of the electrical control cabinet 1.

[0041] Furthermore, the first refrigeration circuit and the second refrigeration circuit can exchange heat in the condenser 14 .

[0042] When the first cooling medium or the second cooling medium flows through the first heat sink 2 , it exchanges heat with the air in the electrical control cabinet 1 , thereby reducing the temperature in the electrical control cabinet 1 .

[0043] Example 2

[0044] This embodiment provides a method for using a cooling device for an electrical control cabinet for a sewage treatment plant. The method uses a cooling device for an electrical control cabinet for a sewage treatment plant provided in Example 1, and includes the following steps:

[0045] S1, obtaining the temperature and humidity inside the electrical control cabinet 1 and the environment where the electrical control cabinet 1 is located, the temperature of the first cooling medium flowing into and out of the first heat sink 2, the temperature of the sewage where the second heat sink 5 is located, and the temperature range inside the electrical control cabinet 1 that allows normal operation;

[0046] S2, judging whether the temperature in the electrical control cabinet 1 is within the temperature range in the electrical control cabinet 1 that allows normal operation, and controlling the opening or closing of the cooling device of the electrical control cabinet;

[0047] S3, calculating the dew point temperature in the electrical control cabinet 1 and the environment in which the electrical control cabinet 1 is located according to the temperature and humidity in the electrical control cabinet 1 and the environment in which the electrical control cabinet 1 is located;

[0048] S4, setting a suitable cooling temperature according to the calculated dew point temperature and the temperature range inside the electrical control cabinet 1 that allows normal operation, so that the cooling device of the electrical control cabinet operates according to the preset control strategy 1 or strategy 2;

[0049] S5. If the difference between the temperature in the electrical control cabinet 1 and the sewage temperature is greater than the first set value, the electrical control cabinet cooling device operates according to a preset control strategy 1;

[0050] Further, the preset control strategy 1 includes: closing the first electric valve 16 and the second electric valve 17, opening the third electric valve 18 and the fourth electric valve 19, starting the circulation pump 4, and the first cooling medium flows from the first pipeline in the first heat dissipation device 2 through the seventh cooling pipeline 12, the second cooling pipeline 7, the second heat dissipation device 5, the fifth cooling pipeline 10 and the first cooling pipeline 6 back to the first pipeline in the first heat dissipation device 2; adjusting the operating frequency of the circulation pump 4 or the opening of the third electric valve 18 and the fourth electric valve 19 according to the temperature change in the electrical control cabinet 1;

[0051] S6. If the difference between the temperature in the electrical control cabinet 1 and the sewage temperature is less than or equal to the second set ceiling value, the electrical control cabinet cooling device operates according to the preset control strategy 2;

[0052] Further, the preset control strategy 2 includes: closing the third electric valve 18 and the fourth electric valve 19, opening the first electric valve 16 and the second electric valve 17, starting the circulation pump 4, and the first cooling medium passes through the second cooling pipeline 7, the second heat sink 5, the fifth cooling pipeline 10, the first electric valve 16, the condenser 14, the fourth cooling pipeline 9, and the second electric valve 17, and returns to the first refrigeration circuit; the second cooling medium passes through the third cooling pipeline 8, the compressor 13, the condenser 14, the thermal expansion valve 15, and the sixth cooling pipeline 11 and flows back to the second heat sink 2 to form a second refrigeration circuit; wherein the first refrigeration circuit and the second refrigeration circuit can exchange heat in the condenser 14;

[0053] The operating frequency of the circulation pump 4 or the openings of the first electric valve 16 and the second electric valve 17 are adjusted according to the temperature change of the first cooling medium flowing into and out of the condenser 14 .

[0054] Furthermore, the second set value is smaller than the first set value and can be adjusted according to the actual temperature change.

[0055] Example 3

[0056] like Figure 2As shown, the present embodiment further provides a cooling device for an electrical control cabinet for a sewage treatment plant, comprising an electrical control cabinet 1, a first heat dissipation device 2 and a second heat dissipation device 5, wherein the second heat dissipation device 5 is located in a sewage treatment tank, the first heat dissipation device 2 is located in the electrical control cabinet 1, a fan 3 is also provided in the electrical control cabinet 1, a pipeline is provided in the first heat dissipation device 2, one end of the pipeline in the first heat dissipation device 2 is connected to the first cooling pipeline 6, and the other end is connected to the seventh cooling pipeline 12, the first cooling pipeline 6 is connected to one end of the second heat dissipation device 5, and the seventh cooling pipeline 12 is connected to the other end of the second heat dissipation device 5.

[0057] Furthermore, the first cooling pipeline 6 is connected to the second heat dissipation device 5 through the fifth cooling pipeline 10, and a third electric valve 18 is provided on the first cooling pipeline 6; the seventh cooling pipeline 12 is connected to the second heat dissipation device 5 through the second cooling pipeline 7, and a circulating pump 4 is provided on the second cooling pipeline 7.

[0058] The first cooling medium enters the first heat dissipation device 2 in the electrical control cabinet 1 through the first cooling pipeline 6, and the temperature in the electrical control cabinet 1 is evenly cooled by the fan 3;

[0059] The first cooling medium is pressurized by the circulation pump 4 and flows sequentially through the seventh cooling pipeline 12, the second cooling pipeline 7, the second heat sink 5 located in the sewage treatment tank, the fifth cooling pipeline 10, the second and third electric valves 18, the first cooling pipeline 6 and flows back into the first heat sink 2;

[0060] When the first cooling medium flows through the first heat sink 2, it exchanges heat with the air in the electrical control cabinet 1, thereby reducing the temperature in the electrical control cabinet 1;

[0061] When the first cooling medium flows through the second heat dissipation device 5, it exchanges heat with the sewage, thereby reducing the temperature of the first cooling medium.

[0062] Example 4

[0063] This embodiment further provides a method for using a cooling device for an electrical control cabinet for a sewage treatment plant. The method uses a cooling device for an electrical control cabinet for a sewage treatment plant provided in Example 3, and includes the following steps:

[0064] S1, obtaining the temperature and humidity inside the electrical control cabinet 1 and the environment in which the electrical control cabinet is located, the temperature of the first cooling medium flowing into and out of the first heat sink 2, the temperature of the sewage in the second heat sink 5, and the temperature range inside the electrical control cabinet 1 that allows normal operation;

[0065] S2, judging whether the temperature in the electrical control cabinet 1 is within the temperature range in the electrical control cabinet 1 that allows normal operation, and controlling the opening or closing of the cooling device of the electrical control cabinet;

[0066] S3. Calculate the dew point temperature in the electrical control cabinet 1 and the environment in which the electrical control cabinet is located according to the temperature and humidity in the electrical control cabinet 1 and the environment in which the electrical control cabinet is located.

[0067] S4. Setting a suitable cooling temperature according to the calculated dew point temperature and the temperature range inside the electrical control cabinet 1 that allows normal operation, so that the cooling device of the electrical control cabinet operates according to a preset control strategy.

[0068] Furthermore, the preset control strategy includes: turning on the circulation pump 4, the first cooling medium flows through the seventh cooling pipeline 12, the second cooling pipeline 7, the second heat dissipation device 5 located in the sewage treatment tank, the fifth cooling pipeline 10, the second and third electric valves 18, and the first cooling pipeline 6 to flow back to the first heat dissipation device 2; adjusting the operating frequency of the circulation pump 4 according to the temperature changes in the electrical control cabinet 1.

[0069] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cooling device for an electrical control cabinet for a sewage treatment plant, characterized in that: The invention comprises an electrical control cabinet (1), a first heat dissipation device (2) and a second heat dissipation device (5), wherein the second heat dissipation device (5) is located in a sewage treatment tank, the first heat dissipation device (2) is located in the electrical control cabinet (1), a fan (3) is also arranged in the electrical control cabinet (1), a pipeline is arranged in the first heat dissipation device (2), one end of the pipeline in the first heat dissipation device (2) is connected to a first cooling pipeline (6), and the other end is connected to a seventh cooling pipeline (12), the first cooling pipeline (6) is connected to one end of the second heat dissipation device (5), and the seventh cooling pipeline (12) is connected to the other end of the second heat dissipation device (5); The first cooling pipeline (6) is connected to the second heat dissipation device (5) via a fifth cooling pipeline (10), and a third electric valve (18) is provided on the first cooling pipeline (6); the seventh cooling pipeline (12) is connected to the second heat dissipation device (5) via a second cooling pipeline (7), and a circulation pump (4) is provided on the second cooling pipeline (7); The pipelines in the first heat dissipation device (2) include a first pipeline and a second pipeline, the first pipeline and the second pipeline are both disc-shaped pipelines, and the two disc-shaped pipelines are independent of each other and do not interfere with each other, the two ends of the first pipeline are respectively connected to the first cooling pipeline (6) and the seventh cooling pipeline (12); the two ends of the second pipeline are respectively connected to the third cooling pipeline (8) and the sixth cooling pipeline (11); the air outlet of the fan (3) is directly opposite to the two disc-shaped pipelines in the first heat dissipation device (2); A first cooling medium is arranged in the first pipeline. Under the action of the circulation pump (4), the first cooling medium flows from the first pipeline in the first heat dissipation device (2), through the seventh cooling pipeline (12), the second cooling pipeline (7), the second heat dissipation device (5), the fifth cooling pipeline (10) and the first cooling pipeline (6), back to the first pipeline in the first heat dissipation device (2), thereby forming a first refrigeration circuit. When the first cooling medium flows through the second heat dissipation device (5), heat is exchanged with sewage in the sewage treatment tank, thereby reducing the temperature of the first cooling medium. It also includes a condenser (14), wherein the third cooling pipeline (8) and the sixth cooling pipeline (11) extend into the condenser (14) respectively and are connected in the condenser (14); a compressor (13) is provided on the third cooling pipeline (8), and a thermal expansion valve (15) is provided on the sixth cooling pipeline (11); A second cooling medium is arranged in the second pipeline, and the second cooling medium flows from the second pipeline in the first heat dissipation device (2), passes through the third cooling pipeline (8), the compressor (13), the condenser (14), the thermal expansion valve (15) and the sixth cooling pipeline (11), and then flows back to the second pipeline in the first heat dissipation device (2), thereby forming a second refrigeration circuit; A fourth cooling pipeline (9) is further provided in the condenser (14); one end of the fourth cooling pipeline (9) is connected to the second cooling pipeline (7); the other end of the fourth cooling pipeline (9) is connected to the fifth cooling pipeline (10); a first electric valve (16) and a second electric valve (17) are provided on the fourth cooling pipeline (9); and a fourth electric valve (19) is provided on the seventh cooling pipeline (12); the first cooling medium is pressurized by the circulation pump (4) and flows through the seventh cooling pipeline (12), the cooling pipeline (10) and the cooling pipeline (11) in sequence. (7) The second heat dissipation device (5) can select the first cooling medium to enter through the cooling pipeline (6) and flow back into the first heat dissipation device (2) or to enter the condenser (14) through the fourth cooling pipeline (9) by opening or closing the first electric valve (16), the second electric valve (17), the third electric valve (18) and the fourth electric valve (19); when the first cooling medium enters the condenser (14), the first cooling medium and the second cooling medium that have undergone heat exchange in the second heat dissipation device (5) exchange heat in the condenser (14).

2. A method for using a cooling device for an electrical control cabinet in a sewage treatment plant, characterized in that: The cooling device for the electrical control cabinet for a sewage treatment plant according to claim 1 is applied, comprising the following steps: S1, obtaining the temperature and humidity inside the electrical control cabinet (1) and the environment in which the electrical control cabinet (1) is located, the temperature of the first cooling medium flowing into and out of the first heat dissipation device (2), the temperature of the sewage in the second heat dissipation device (5), and the temperature range inside the electrical control cabinet (1) that allows normal operation; S2, judging whether the temperature in the electrical control cabinet (1) is within the temperature range in the electrical control cabinet (1) that allows normal operation, and controlling the electrical control cabinet cooling device to be turned on or off; S3, calculating the dew point temperature inside the electrical control cabinet (1) and the environment in which the electrical control cabinet (1) is located according to the temperature and humidity inside the electrical control cabinet (1) and the environment in which the electrical control cabinet (1) is located; S4, setting a suitable cooling temperature according to the calculated dew point temperature and the temperature range within the electrical control cabinet (1) that allows normal operation, so that the cooling device of the electrical control cabinet operates according to the preset control strategy 1 or strategy 2; S5, if the difference between the temperature in the electrical control cabinet (1) and the sewage temperature is greater than a first set value, the electrical control cabinet cooling device operates according to a preset control strategy 1; S6. If the difference between the temperature in the electrical control cabinet (1) and the sewage temperature is less than or equal to the second set ceiling value, the electrical control cabinet cooling device operates according to the preset control strategy 2; The control strategy 1 preset in S5 includes: closing the first electric valve (16) and the second electric valve (17), opening the third electric valve (18) and the fourth electric valve (19), starting the circulation pump (4), and allowing the first cooling medium to flow back from the first pipeline in the first heat dissipation device (2) through the seventh cooling pipeline (12), the second cooling pipeline (7), the second heat dissipation device (5), the fifth cooling pipeline (10) and the first cooling pipeline (6) to the first pipeline in the first heat dissipation device (2); and adjusting the operating frequency of the circulation pump (4) or the opening degree of the third electric valve (18) and the fourth electric valve (19) according to the temperature change in the electrical control cabinet (1); The control strategy 2 preset in S6 includes: closing the third electric valve (18) and the fourth electric valve (19), opening the first electric valve (16) and the second electric valve (17), starting the circulation pump (4), and returning the first cooling medium to the first refrigeration circuit through the second cooling pipeline (7), the second heat dissipation device (5), the fifth cooling pipeline (10), the first electric valve (16), the condenser (14), the fourth cooling pipeline (9), and the second electric valve (17); the second cooling medium flows back to the second heat dissipation device (2) through the third cooling pipeline (8), the compressor (13), the condenser (14), the thermal expansion valve (15), and the sixth cooling pipeline (11), thereby forming a second refrigeration circuit; wherein the first refrigeration circuit and the second refrigeration circuit can exchange heat in the condenser (14); and adjusting the operating frequency of the circulation pump (4) or the opening degree of the first electric valve (16) and the second electric valve (17) according to the temperature change of the first cooling medium flowing into and out of the condenser (14).

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