Automatic air exhausting device of sewage pump

Abstract

The invention provides an automatic air exhausting device of a sewage pump, and belongs to the technical field of air exhausting of self-suction sewage pumps of wastewater pools. Comprising a sewage pump, a sewage pump outlet pipeline, a sewage pump outlet exhaust pipeline and a water injection pipeline above a pump body gas-liquid separation chamber, the sewage pump outlet pipeline and the sewage pump outlet exhaust pipeline are installed at an outlet of the sewage pump, the sewage pump is further provided with the water injection pipeline above the pump body gas-liquid separation chamber, and a water inlet pipeline of the sewage pump is connected to a wastewater pool. The automatic air exhaust device of the wastewater pool self-suction sewage pump has the advantages of being simple in structure, easy and convenient to operate, remarkable in effect and the like, can effectively solve the problems that in the operation process of a traditional self-suction sewage pump, water does not flow out of an outlet pipe of a single pump or double pumps, and pressure does not rise, and further improves the operation stability and reliability of environment-friendly equipment; the labor cost of operation and maintenance is reduced, and the equipment failure rate is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of air exhausting for self-priming sewage pumps in wastewater pools, and particularly to an automatic air exhausting device for sewage pumps. Background Art

[0002] There are 2 liquid ammonia storage tanks set in the ammonia area of a certain power plant, with a designed total storage capacity of about 51t, belonging to the third-level major hazard source. The plant implemented the comprehensive treatment project for major hazard sources in the ammonia area in 2024, and the reducing agent for the denitration system was changed from liquid ammonia to urea hydrolysis to produce ammonia. The liquid such as hydrophobic water and urea residue in this project is uniformly discharged into a newly built wastewater pool with a volume of 20m³. The liquid in the pool is the sewage from each hydrophobic pipeline, urea hydrolysis tank, etc. The liquid contains a small amount of urea residue, and sometimes there may also be a small amount of chloride ions, with certain corrosiveness. The liquid temperature is relatively high, and sometimes spray cooling water is required. Two self-priming centrifugal sewage pumps are installed in this wastewater pool. The present invention is described with one sewage pump.

[0003] Since there is no check valve installed at the outlet of the self-priming sewage pump, after the sewage pump stops running, the liquid in the pipeline flows back to the wastewater pool. Restricted by the siphon effect, the amount of residual liquid in the pump is very small. When the liquid level in the wastewater pool is high, after the sewage pump starts, the impeller sucks in the small amount of residual liquid stored in the pump chamber and the air inhaled from the inlet pipeline together, and under the action of centrifugal force, it flows towards the outer edge of the volute, and the process is repeated continuously until the air is exhausted and the self-priming process is completed. Due to the small amount of residual liquid in the pump, it is difficult to establish a negative pressure at the pump inlet. In addition, the temperature in the wastewater pool is relatively high, sometimes close to 90°C. At a relatively high temperature, the density of the liquid decreases, and there are many bubbles in the urea solution in the waste liquid, which is also not conducive to the pump to establish a self-priming process.

[0004] During the operation of the sewage pump, the phenomenon that the outlet pipe of a single pump or both pumps fails to build pressure often occurs. Although manual liquid addition is carried out from the liquid addition hole at the pump inlet on-site, but only a few seconds later, the pump outlet pressure returns to zero again. Repeating like this is very laborious and time-consuming, running counter to the current advocated unmanned duty and not meeting the requirements of lean management. Summary of the Invention

[0005] The purpose of the present invention is to eliminate the problems that the outlet pipe of the self-priming sewage pump in the wastewater pool does not discharge water and does not build pressure, improve and correct the deficiencies existing in the pipeline design of the existing sewage system, and provide an automatic air exhausting device for sewage pumps, which can realize remote control and automatic operation.

[0006] To solve the above technical problems, the present invention discloses an automatic air exhausting device for sewage pumps, including: The sewage pump, the outlet pipeline of the sewage pump, the exhaust pipeline of the sewage pump outlet, and the water injection pipeline above the gas-liquid separation chamber of the pump body. The outlet of the sewage pump is installed with the outlet pipeline of the sewage pump and the exhaust pipeline of the sewage pump outlet. The sewage pump is also provided with a water injection pipeline above the gas-liquid separation chamber of the pump body. The inlet pipeline of the sewage pump is connected to the wastewater tank.

[0007] Preferably, a local pressure gauge and a first pressure sensor are installed on the outlet pipeline of the sewage pump. A check valve is also installed on the outlet pipeline of the sewage pump. The outlet of the outlet pipeline of the sewage pump is connected to the sewage treatment station.

[0008] Preferably, an air exhaust electric door is installed on the exhaust pipeline of the sewage pump outlet.

[0009] Preferably, a radar level gauge is installed on the upper part of the wastewater tank.

[0010] Preferably, a second pressure sensor is installed on the water injection pipeline above the gas-liquid separation chamber of the pump body.

[0011] Preferably, an injection electric door is installed on the water injection pipeline above the gas-liquid separation chamber of the pump body; on the water injection pipeline above the gas-liquid separation chamber of the pump body, before and after the electric injection door, an injection bypass manual door is installed; on the water injection pipeline above the gas-liquid separation chamber of the pump body, on the water inlet side of the injection electric door, an industrial water injection manual door and a domestic water injection manual door are installed.

[0012] Preferably, it further includes: Temperature sensor: used to detect the air temperature in the exhaust pipeline of the sewage pump outlet; Third pressure sensor: used to detect the air pressure on the inlet side of the air exhaust electric door in the exhaust pipeline of the sewage pump outlet; Timer: used to time the working duration of the sewage pump; Intelligent control module, electrically connected to the temperature sensor, the third pressure sensor, and the timer respectively.

[0013] Preferably, the intelligent control module includes: First calculation unit: used to calculate the equivalent air pressure parameter at the current time when the triggering condition is met based on the detection value of the third pressure sensor in the latest first historical period at the current time when the triggering condition is met; the triggering condition is that the detection value of the third pressure sensor is greater than or equal to the first air pressure; ; P is the equivalent air pressure parameter at the current time when the triggering condition is met; is the detection value of the third pressure sensor at the current time when the triggering condition is met; is the detection value of the third pressure sensor at the current time when the triggering condition is met; M is the total number of detections of the third pressure sensor in the latest first historical period at the current time when the triggering condition is met; The k-th detection value of the third pressure sensor within the latest first historical period when the current time meets the trigger condition times detection value; is the k-th detection value of the third pressure sensor within the latest first historical period when the current time meets the trigger condition; is the target air discharge time corresponding to the current time when the trigger condition is met; the time intervals between two adjacent detections of the third pressure sensor in the latest first historical period when the current time meets the trigger condition are the same and are all ; The first determination unit: used to determine the target flow rate of the air discharge electric door when the current time meets the trigger condition based on the equivalent air pressure parameter and the detection value of the temperature sensor when the current time meets the trigger condition; The first control unit: used to control the air discharge electric door to work when the current time meets the trigger condition, so that the actual gas flow rate on the outlet side thereof is the target flow rate of the air discharge electric door when the current time meets the trigger condition.

[0014] Preferably, it further includes: a fourth pressure sensor: used to detect the air pressure at the outlet of the exhaust pipeline of the sewage pump outlet; When the current time meets the trigger condition, the target flow rate of the air discharge electric door is calculated based on the following formula: ; D is the inner diameter of the exhaust pipeline of the sewage pump outlet; is the median of the target allowable air pressure range of the third pressure sensor after the air discharge electric door discharges air; takes the value of 3.14; L is the length of the exhaust pipeline of the sewage pump outlet from the end connected to the sewage pump outlet to the inlet of the air discharge electric door; is the air pressure at the outlet of the exhaust pipeline of the sewage pump outlet detected by the fourth pressure sensor when the current time meets the trigger condition; k is the adiabatic index of air; is the detection value of the temperature detection device when the current time meets the trigger condition; is the standard air temperature.

[0015] Compared with the prior art, the beneficial effects of the present invention are: Remote control and automatic operation, with high automation degree, can effectively reduce the on-site inspection and operation workload of operating personnel.

[0016] Automatic water injection, rapid start-up and pressure boost, reduce the water injection time of maintenance personnel through the liquid filling hole, and reduce the workload of maintenance personnel.

[0017] A check valve is added to the pipeline of the sewage pump outlet, effectively preventing the siphon phenomenon caused by the backflow of the medium in the pipeline and preventing the phenomenon that the medium in the liquid storage chamber below the pump body is sucked away passively. Ensure that there is always a certain height of liquid in the pump body, thus ensuring the stable emptying operation of the sewage pump.

[0018] An electric air exhaust valve is added to the outlet pipeline of the sewage pump to reduce the air exhaust time after the pump starts.

[0019] The automatic air exhaust device for the self-priming sewage pump in the wastewater tank of the present invention has the advantages of simple structure, convenient operation, and remarkable effect. It can effectively solve the problems of no water discharge and no pressure rise in the outlet pipes of single pumps or double pumps during the operation of traditional self-priming sewage pumps, further improve the operation stability and reliability of environmental protection equipment, reduce the labor costs of operation and maintenance, and reduce the equipment failure rate. Brief Description of the Drawings

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic diagram of an automatic air exhaust device for a sewage pump according to the present invention.

[0022] Among them, 1. Wastewater tank; 2. Sewage pump; 3. Outlet pipeline of the sewage pump; 4. Exhaust pipeline; 5. Water injection pipeline; 6. Radar level gauge; 7. Pressure gauge; 8. Outlet pipeline pressure sensor; 9. Check valve; 10. Air exhaust electric valve; 11. Water injection pipeline pressure sensor; 12. Water injection electric valve; 13. Water injection bypass manual valve; 14. Industrial water injection manual valve; 15. Domestic water injection manual valve; 16. Sewage treatment station. Detailed Embodiments

[0023] In order to make the purpose, technical solutions, and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0024] Embodiment 1: As Figure 1 shown, an automatic air exhaust device for a sewage pump provided by an embodiment of the present invention includes: The sewage pump 2, the sewage pump outlet pipeline 3, the sewage pump outlet exhaust pipeline 4, and the water injection pipeline 5 above the gas-liquid separation chamber of the pump body. The outlet of the sewage pump 2 is installed with the sewage pump outlet pipeline 3 and the sewage pump outlet exhaust pipeline 4. The sewage pump 2 is also provided with the water injection pipeline 5 above the gas-liquid separation chamber of the pump body. The inlet pipeline of the sewage pump 2 is connected to the wastewater tank 1.

[0025] Preferably, a local pressure gauge 7 and a first pressure sensor 8 are installed on the sewage pump outlet pipeline 3. A check valve 9 is also installed on the sewage pump outlet pipeline 3. The outlet of the sewage pump outlet pipeline 3 is connected to the sewage treatment station 16. The local pressure gauge 7 facilitates observing the pump outlet pressure locally; the first pressure sensor 8 facilitates the operating centralized control personnel to observe the pump outlet pressure remotely (the first pressure sensor 8 is connected to the control device, and the control device is communicatively connected to the remote monitoring terminal); the check valve 9 can effectively prevent the sewage from flowing back and causing the emptying phenomenon caused by the siphon effect of the liquid in the pump when the sewage pump 2 stops operating. Preferably, an air exhaust electric valve 10 is installed on the sewage pump outlet exhaust pipeline 4, which is beneficial for remotely operating to discharge the air in the pipeline during startup.

[0026] Preferably, a radar level gauge 6 (used to measure the liquid level of the wastewater tank) is installed on the upper part of the wastewater tank 1.

[0027] Preferably, a second pressure sensor 11 (detecting the water injection pressure in the pump body) is installed on the water injection pipeline 5 above the gas-liquid separation chamber of the pump body.

[0028] Preferably, a water injection electric valve 12 (facilitating remote operation) is installed on the water injection pipeline 5 above the gas-liquid separation chamber of the pump body; on the water injection pipeline 5 above the gas-liquid separation chamber of the pump body, a water injection bypass manual valve 13 is installed before and after the electric water injection valve 12; on the water injection pipeline 5 above the gas-liquid separation chamber of the pump body, an industrial water injection manual valve 14 and a domestic water injection manual valve 15 are installed on the water inlet side of the water injection electric valve 12. The water injection electric valve 12, the industrial water injection manual valve 14, and the domestic water injection manual valve 15 can not only provide water injection and emptying for the pump body, but also be used as the water source for flushing the pump body after the sewage pump stops operating, preventing the corrosion phenomenon caused by high chloride ion content in the pump body and the impeller, achieving multiple benefits at one stroke. The water injection water sources are used in a one-for-one standby manner. The water injection bypass manual valve 13 introduces bypass water injection for local manual operation.

[0029] Furthermore, optimize the water pressure logic of the sewage pump outlet pipeline. When the water pressure of the sewage pump outlet pipeline ≥ 0.2 MPa, the sewage pump exhaust electric valve and the electric valve of the water injection pipeline above the gas-liquid separation chamber of the pump body will automatically close.

[0030] Furthermore, introduce two water injection water sources to prevent the situation where there is no standby water source after any one water source stops operating.

[0031] Furthermore, two water injection sources are introduced. They are not only used for water injection and drainage, but also can be used to flush the clear water inside the pump body after the pump stops operating, preventing corrosion caused by the long-term shutdown of the sewage pump, achieving two goals with one action.

[0032] The overall process logic of the present invention is optimized as follows: when the liquid level in the wastewater tank is 1500 mm, the water injection electric valve above the gas-liquid separation chamber on the sewage pump body automatically starts. When the pressure on the water injection pipeline is not less than 0.1 MPa and lasts for 30 seconds, the sewage pump automatically starts, and at the same time, the exhaust electric valve of the sewage pump automatically opens. When the water pressure at the outlet pipeline of the sewage pump is ≥ 0.2 MPa, the exhaust electric valve of the sewage pump and the water injection pipeline electric valve of the pump body gas-liquid separation chamber automatically close. When the liquid level in the wastewater tank is lower than 300 mm, the wastewater pump stops operating. 60 seconds after the stop, the water injection electric valve opens to flush the inside of the pump body for 30 seconds. After flushing for 30 seconds, the water injection electric valve automatically closes.

[0033] The beneficial effects of the above technical solutions are as follows: The local pressure gauge 7 facilitates on-site inspection personnel to observe the pressure on the outlet pipeline 3 of the sewage pump on-site, facilitating comparison with the remote pressure value and promptly discovering abnormal phenomena. Installing the first pressure sensor 8 and the exhaust air electric valve 10 facilitates the remote monitoring and operation of the operator, facilitating remote automatic control and enabling the remote control personnel in the operation centralized control room to observe the pump outlet pressure situation. Installing the check valve 9 helps prevent the reverse flow of sewage to cause siphonage, resulting in the liquid inside the pump being sucked back to the sewage tank, and is conducive to the quick start of the sewage pump.

[0034] Adopting two-way water injection can effectively ensure that there is one way available for pump body water injection and drainage in case of failure of any one water source; it can also play a role in flushing and anti-corrosion of the pump body after the sewage pump stops operating, effectively preventing the corrosion phenomenon of the pump body and impeller caused by high chloride ion content. One water injection source is used as the main and the other as the standby to ensure reliable water supply.

[0035] Remote control and automatic operation, with a high degree of automation, can effectively reduce the on-site inspection and operation workload of the operating personnel.

[0036] Automatic water injection, rapid start-up and pressure increase, reducing the water injection time through the liquid filling hole by maintenance personnel and reducing the workload of maintenance personnel.

[0037] A check valve is added to the outlet pipeline of the sewage pump, effectively preventing the siphonage phenomenon caused by the reflux of the medium in the pipeline and preventing the phenomenon that the medium in the liquid storage chamber below the pump body is sucked away passively. Ensure that there is always a certain height of liquid inside the pump body, thus ensuring the stable drainage operation of the sewage pump.

[0038] An electric exhaust air valve is added to the outlet pipeline of the sewage pump, reducing the air exhaust time after the pump starts.

[0039] The automatic air exhausting device for the wastewater tank self-priming sewage pump of the present invention has the advantages of simple structure, convenient operation, and remarkable effect. It can effectively solve the problems of no water discharge and no pressure rise in the outlet pipes of single or double pumps that occur during the operation of traditional self-priming sewage pumps, further improve the operation stability and reliability of environmental protection equipment, reduce the labor costs of operation and maintenance, and reduce the equipment failure rate.

[0040] Embodiment 2, on the basis of Embodiment 1, further includes: Temperature sensor: used to detect the air temperature in the exhaust pipeline 4 of the sewage pump outlet; Third pressure sensor: used to detect the air pressure on the inlet side of the air exhaust electric valve 10 in the exhaust pipeline 4 of the sewage pump outlet; Timer: used to time the working duration of the sewage pump 2; Intelligent control module, electrically connected to the temperature sensor, the third pressure sensor, and the timer respectively.

[0041] Preferably, the intelligent control module includes: First calculation unit: used to calculate the equivalent air pressure parameter at the current time when the trigger condition is met based on the detection value of the third pressure sensor in the latest first historical period at the current time when the trigger condition is met; the trigger condition is that the detection value of the third pressure sensor is greater than or equal to the first air pressure; ; P is the equivalent air pressure parameter at the current time when the trigger condition is met; is the detection value of the third pressure sensor at the current time when the trigger condition is met; is the detection value of the third pressure sensor at the current time when the trigger condition is met; M is the total number of detections of the third pressure sensor in the latest first historical period at the current time when the trigger condition is met; is the kth detection value of the third pressure sensor in the latest first historical period at the current time when the trigger condition is met; is the kth detection value of the third pressure sensor in the latest first historical period at the current time when the trigger condition is met; is the target air exhausting time corresponding to the current time when the trigger condition is met (which can be determined based on - -target air exhausting time mapping table, 、 the larger, the larger the target air exhausting time); the time intervals between two adjacent detections of the third pressure sensor in the latest first historical period at the current time when the trigger condition is met are the same and are all ; The first determination unit: configured to determine the target flow rate of the air exhaust electric valve 10 when the triggering condition is satisfied for the current time based on the equivalent air pressure parameter and the temperature sensor detection value when the triggering condition is satisfied for the current time; The first control unit: configured to control the air electric valve 10 to operate when the triggering condition is satisfied for the current time, so that the actual gas flow rate on the outlet side thereof is the target flow rate of the air exhaust electric valve 10 when the triggering condition is satisfied for the current time.

[0042] Preferably, it further includes: a fourth pressure sensor: configured to detect the air pressure at the outlet of the exhaust pipe 4 of the sewage pump outlet; When the triggering condition is satisfied for the current time, the target flow rate of the air exhaust electric valve 10 is calculated based on the following formula: ; D is the inner diameter of the exhaust pipe 4 of the sewage pump outlet; is the median of the target allowable air pressure range of the third pressure sensor after the air exhaust by the air exhaust electric valve 10; takes a value of 3.14; L is the length of the exhaust pipe 4 of the sewage pump outlet from the end connected to the outlet of the sewage pump 2 to the inlet of the air exhaust electric valve 10; is the air pressure at the outlet of the exhaust pipe 4 of the sewage pump outlet detected by the fourth pressure sensor when the triggering condition is satisfied for the current time; k is the adiabatic index of air; is the detection value of the temperature detection device when the triggering condition is satisfied for the current time; is the standard air temperature.

[0043] The beneficial effects of the above technical solution are: Each time the triggering condition is satisfied, the first calculation unit starts to calculate, reducing the frequent operation of the air exhaust electric valve 10; The first calculation unit: configured to, when the triggering condition is satisfied for the current time, calculate the equivalent air pressure parameter when the triggering condition is satisfied for the current time based on the detection value of the third pressure sensor in the latest first historical period when the triggering condition is satisfied for the current time; the equivalent air pressure parameter when the triggering condition is satisfied for the current time reflects the air pressure change rate based on the latest first historical period when the triggering condition is satisfied for the current time , the estimated air pressure on the inlet side of the air exhaust electric valve 10 in the exhaust pipe 4 of the sewage pump outlet from the current time to after the target air exhaust time corresponding to the current time when the triggering condition is satisfied for the current time obtained from the target air exhaust time corresponding to the current time when the triggering condition is satisfied for the current time; Determine the basic flow rate of the air exhaust electric valve 10 when the triggering condition is satisfied for the current time based on the equivalent air pressure parameter when the triggering condition is satisfied for the current time ; and then correct it based on the temperature sensor detection value , the air pressure at the outlet of the exhaust pipe 4 of the sewage pump outlet When the correction obtains the target flow rate of the air exhaust motorized valve 10 when the triggering condition is satisfied this time, the calculation is reliable, ensuring reliable control of the air exhaust motorized valve 10.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic air exhaust device for a sewage pump, characterized in that: include: A sewage pump (2), a sewage pump outlet pipe (3), a sewage pump outlet exhaust pipe (4), and a water injection pipe (5) above the gas-liquid separation chamber of the pump body. The sewage pump (2) is provided with a sewage pump outlet pipe (3) and a sewage pump outlet exhaust pipe (4) at the outlet. The sewage pump (2) is also provided with a water injection pipe (5) above the gas-liquid separation chamber of the pump body. The water inlet pipe of the sewage pump (2) is connected to the wastewater pool (1).

2. The automatic air exhaust device for a sewage pump according to claim 1, characterized in that: An on-site pressure gauge (7) and a first pressure sensor (8) are installed on the sewage pump outlet pipe (3), and a check valve (9) is also installed on the sewage pump outlet pipe (3). The outlet of the sewage pump outlet pipe (3) is connected to a sewage treatment station (16).

3. The automatic air exhaust device for a sewage pump according to claim 1, characterized in that: An air exhaust electric door (10) is installed on the exhaust pipe (4) at the outlet of the sewage pump.

4. The automatic air exhaust device for a sewage pump according to claim 2, characterized in that: A radar level meter (6) is installed on the upper part of the wastewater tank (1).

5. The automatic air exhaust device for a sewage pump according to claim 2, characterized in that: A second pressure sensor (11) is installed on the water injection pipe (5) above the gas-liquid separation chamber of the pump body.

6. The automatic air exhaust device for a sewage pump according to claim 5, characterized in that: An electric water injection door (12) is installed on the water injection pipe (5) above the gas-liquid separation chamber of the pump body; a water injection bypass manual door (13) is installed on the water injection pipe (5) above the gas-liquid separation chamber of the pump body, located before and after the electric water injection door (12); and an industrial water injection manual door (14) and a domestic water injection manual door (15) are installed on the water injection pipe (5) above the gas-liquid separation chamber of the pump body, located on the water inlet side of the electric water injection door (12).

7. The automatic air exhaust device for a sewage pump according to claim 1, characterized in that: Also includes: Temperature sensor: used to detect the temperature in the exhaust pipe (4) at the outlet of the sewage pump; A third pressure sensor is used to detect the air pressure in the exhaust pipe (4) at the outlet of the sewage pump and located on the inlet side of the exhaust air electric door (10); Timer: used to measure the working time of the sewage pump (2); The intelligent control module is electrically connected to the temperature sensor, the third pressure sensor and the timer respectively.

8. The automatic air exhaust device for a sewage pump according to claim 7, characterized in that: The intelligent control module comprises: A first calculation unit: used for calculating the equivalent air pressure parameter when the trigger condition is met for the current time based on the detection value of the third pressure sensor in the latest first historical period when the trigger condition is met for the current time when the trigger condition is met for the current time; the trigger condition is that the detection value of the third pressure sensor is greater than or equal to the first air pressure; ； P is the equivalent air pressure parameter when the trigger condition is met for the current time; is the detection value of the third pressure sensor when the trigger condition is met for the last time; is the detection value of the third pressure sensor when the trigger condition is met for the current time; M is the total number of detections of the third pressure sensor in the latest first historical period when the trigger condition is met for the current time; is the kth value of the third pressure sensor in the latest first historical period when the trigger condition is met for the current time. Second detection value; is the kth detection value of the third pressure sensor in the latest first historical period when the trigger condition is met for the current time; is the target exhaust time corresponding to the current trigger condition being met; when the trigger condition is met for the current time, the time intervals between two adjacent detections by the third pressure sensor in the latest first historical period are the same and both are ; A first determination unit is used to determine the target flow rate of the exhaust air electric door (10) when the trigger condition is met for the last time based on the equivalent air pressure parameter and the temperature sensor detection value when the trigger condition is met for the last time; A first control unit is used to control the operation of the electric air door (10) when the trigger condition is met for the last time, so that the actual gas flow rate at its outlet side is the target flow rate of the electric exhaust air door (10) when the trigger condition is met for the last time.

9. The automatic air exhaust device for a sewage pump according to claim 8, characterized in that: Also includes: A fourth pressure sensor is used to detect the air pressure at the outlet of the exhaust pipe (4) at the outlet of the sewage pump; When the trigger condition is met for the first time, the target flow rate of the exhaust air electric door (10) is calculated based on the following formula: ； D is the inner diameter of the exhaust pipe (4) at the sewage pump outlet; The middle value of the target allowable air pressure range of the third pressure sensor after the air exhaust electric door (10) exhausts air; The value is 3.14; L is the length of the exhaust pipe (4) at the outlet of the sewage pump from the end connected to the outlet of the sewage pump (2) to the inlet of the exhaust air electric door (10); is the air pressure at the outlet of the exhaust pipe (4) at the outlet of the sewage pump detected by the fourth pressure sensor when the trigger condition is met for the first time; k is the adiabatic index of the air; is the detection value of the temperature detection device when the trigger condition is met for the last time; is the standard air temperature.

Images