Water ring vacuum pump unit and control method

Abstract

The application provides a water ring vacuum pump unit and a control method, and belongs to the technical field of water ring vacuum pumps.The water ring vacuum pump unit comprises a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, a vacuum pump, a steam-water separator, a cooling unit, a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and a control unit.The first pipeline is connected with the vacuum pump.The vacuum pump is connected with the steam-water separator through the second pipeline.The steam-water separator is connected with the cooling unit through the third pipeline.The steam-water separator is connected with the vacuum pump through the fourth pipeline.An exhaust pipe is arranged on the steam-water separator.In the application, steam and water are separated through the steam-water separator, and the separated water is recycled and flows back to the vacuum pump, thereby reducing the waste of water resources, reducing water pollution, and cooling the separated water through the cooling unit before the water flows back to the vacuum pump, thereby effectively avoiding the occurrence of cavitation and prolonging the service life of the vacuum pump.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water ring vacuum pumps, in particular to a water ring vacuum pump unit and a control method. BACKGROUND

[0002] A water ring vacuum pump is a volumetric pump that forms a vacuum through liquid sealing, and its core component is an eccentric cylindrical pump cavity with a radial blade impeller. When working, an appropriate amount of working liquid (usually water) is injected, and when the impeller rotates at high speed, the liquid is subjected to centrifugal force to form an equal-thickness water ring, which forms a periodically changing sealed space with the impeller, thereby realizing gas suction, compression and discharge. The pump has the characteristics of simple structure, stable operation, strong corrosion resistance, etc., and is widely used in the fields of gas suction, vacuum drying and material conveying in chemical industry, pharmaceutical industry, food processing, etc. Its unique water circulation system can not only maintain the vacuum degree but also realize heat exchange, and is particularly suitable for working conditions containing a small amount of condensable gas, has low maintenance cost and strong pollution medium containment.

[0003] However, the traditional water ring vacuum pump has the problem of cavitation during operation: when the local pressure of the liquid in the pump drops below its saturated vapor pressure, the liquid vaporizes to form bubbles, and when these bubbles move to the high pressure area, they burst rapidly, producing shock waves that cause the surface material of the impeller to erode. Long-term cavitation can damage the impeller and affect the performance and service life of the pump. This phenomenon is particularly pronounced in high-temperature environments. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings and deficiencies of the prior art and provide a water ring vacuum pump unit and a control method.

[0005] The technical scheme adopted by the present application is as follows: In a first aspect, the present application provides a water ring vacuum pump unit, comprising a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, a vacuum pump, a water-gas separator, a cooling unit, a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and a control unit, the first pipeline is connected to the vacuum pump for inputting gas thereto, the vacuum pump is connected to the water-gas separator through the second pipeline, the water-gas separator is connected to the cooling unit through the third pipeline, the water-gas separator is connected to the vacuum pump through the fourth pipeline, the water-gas separator is provided with an exhaust pipe, the water-gas separator separates the water vapor delivered by the vacuum pump, the separated gas is discharged through the exhaust pipe, and the separated water is cooled by the cooling unit and then delivered back to the vacuum pump, the first temperature sensor is used to detect the ambient temperature, the second temperature sensor is used to detect the temperature of the backflow water, the third temperature sensor is used to detect the temperature of the cooling water, and the fourth temperature sensor is used to detect the working temperature of the vacuum pump.

[0006] In some embodiments, a fifth pipeline is arranged on the first pipeline, a vacuum gauge is arranged on the fifth pipeline, and a second control valve and a third control valve are arranged on both sides of the vacuum gauge and connected with the first pipeline.

[0007] In some embodiments, a check valve is arranged on the first pipeline near one end of the vacuum pump, and an atmospheric ejector is arranged on the part between the second control valve and the third control valve.

[0008] In some embodiments, a liquid level gauge is arranged on the steam-water separator, a water inlet pipe and a water outlet pipe are arranged on the steam-water separator, a water inlet control valve is arranged on the water inlet pipe, and a water outlet control valve is arranged on the water outlet pipe.

[0009] In some embodiments, a first control valve is arranged on the inlet end of the first pipeline for controlling the flow of gas, and a fourth control valve is arranged on the fourth pipeline for controlling the flow of cooling water.

[0010] In some embodiments, a sixth pipeline is arranged on the exhaust pipe and connected with the first pipeline through the sixth pipeline, and a fifth control valve is arranged on one end of the sixth pipeline near the exhaust pipe.

[0011] In some embodiments, a seventh pipeline is arranged between the steam-water separator and the inlet end of the vacuum pump, and a sixth control valve is arranged on the seventh pipeline.

[0012] In the second aspect, the application provides a control method applied to the water ring vacuum pump unit, comprising the following steps:

[0013] S1: obtaining the ambient temperature based on the first temperature sensor, comparing it with the pre-stored optimal working temperature of the vacuum pump, and generating the estimated temperature of the cooling water according to the difference between the two;

[0014] S2: obtaining the actual working temperature of the vacuum pump in real time based on the fourth temperature sensor, calculating the deviation value of the actual working temperature from the optimal working temperature, and progressively correcting the estimated temperature according to the preset convergence coefficient based on the current deviation value until the absolute value of the deviation value is less than the allowed range;

[0015] S3: recording the operation data set formed by the optimal working temperature, the ambient temperature, the estimated temperature, the actual working temperature and the deviation value in each adjustment process in the database, and executing data optimization replacement when the deviation amount of the new data set is less than the historical record of the same working condition; wherein the same working condition refers to the same optimal working temperature and ambient temperature.

[0016] S4: during the subsequent operation of the water ring vacuum pump unit, the corresponding estimated temperature in the database is directly called based on the ambient temperature.

[0017] In some embodiments, in step S2, based on the backflow water temperature obtained by the second temperature sensor, the cooling power of the cooling unit is adjusted so that the cooling water temperature approaches the estimated temperature.

[0018] Based on the actual temperature of the cooling water obtained by the third temperature sensor, the actual temperature is compared with the estimated temperature, and if it exceeds the allowable range, the cooling power of the cooling unit is readjusted.

[0019] In some embodiments, if the current ambient temperature is lower than the optimal working temperature, the fifth control valve and the sixth control valve are opened, and the opening degree of the fourth control valve is adjusted according to the actual working temperature obtained by the fourth temperature sensor, so that the actual working temperature approaches the optimal working temperature.

[0020] When the actual working temperature is lower than the optimal working temperature, the fourth control valve is closed, and the cooling unit power is reduced or the cooling unit is closed.

[0021] The beneficial effects of the present application are as follows: In the present application, steam and water are separated by a steam-water separator, and the separated water is recirculated back to the vacuum pump, which saves water resources and reduces water pollution. The separated water is cooled by the cooling unit before being recirculated back to the vacuum pump, which effectively avoids the occurrence of cavitation and prolongs the service life of the vacuum pump.

[0022] In the present application, through the cooperative control of the four-way temperature sensing system (ambient temperature, backflow water temperature, cooling water temperature, and pump body temperature) and the closed-loop water circulation system, dynamic optimization of cavitation protection is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings obtained according to these drawings without creative labor are still within the scope of the present application.

[0024] Figure 1 is a schematic diagram of a water ring vacuum pump unit in the present application Figure 1 ;

[0025] Figure 2 is a schematic diagram of a water ring vacuum pump unit in the present application Figure 2 ;

[0026] Figure 3 is a schematic diagram of a water ring vacuum pump unit in the present application Figure 3 ;

[0027] Figure 4 is a schematic diagram of another water ring vacuum pump unit in the present application

[0028] Figure 5 Flowchart of the control method in the present application. DETAILED DESCRIPTION

[0029] The following description provides specific applications and requirements of the present specification, and aims to enable those skilled in the art to manufacture and use the contents of the present specification. Various partial modifications of the disclosed embodiments are obvious to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the present specification. Therefore, the present specification is not limited to the shown embodiments, but is consistent with the widest scope of the claims.

[0030] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "radial", "length", "width", "thickness", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and these terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0031] Secondly, the terms "first", "second" and similar words do not indicate any order, quantity or importance, but are only used to distinguish different components, and should not be understood as a limitation on the embodiments of the present application.

[0032] In addition, the terms "mount", "set", "provided with", "connected", "connected" should be broadly understood. For example, it can be fixedly connected, detachably connected, or integrally constructed; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components.

[0033] For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] The flowchart used in the present application shows the operation of the system implementation according to some embodiments of the present specification. It should be clearly understood that the operations of the flowchart can not be implemented in sequence. On the contrary, the operations can be implemented in reverse order or simultaneously. In addition, one or more other operations can be added to the flowchart. One or more operations can be removed from the flowchart.

[0035] Regarding the drawings of this application, it should be clearly understood that the drawings are for illustration and description purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not necessarily drawn to scale.

[0036] like Figures 1 to 3 As shown, this specification provides a water ring vacuum pump unit, including a first pipeline 1, a second pipeline 2, a third pipeline 3, a fourth pipeline 4, a vacuum pump 5, a steam-water separator 6 and a cooling unit 7. The first pipeline 1 is connected to the vacuum pump 5 for inputting gas therein, the vacuum pump 5 is connected to the steam-water separator 6 through the second pipeline 2, the steam-water separator 6 is connected to the cooling unit 7 through the third pipeline 3, and the steam-water separator 6 is connected to the vacuum pump 5 through the fourth pipeline 4. An exhaust pipe 8 is provided on the steam-water separator 6, and the steam-water separator 6 is used to separate the water vapor transported by the vacuum pump 5. The separated gas is discharged from the exhaust pipe 8, and the separated water is cooled by the cooling unit 7 and transported back to the vacuum pump 5. In this arrangement, the steam and water are separated by the steam-water separator 6, and the separated water is recirculated back to the vacuum pump 5, which reduces the waste of water resources and reduces water pollution. The separated water is cooled by the cooling unit and then returned to the vacuum pump, which effectively avoids the occurrence of cavitation and extends the service life of the vacuum pump.

[0037] A first control valve 9 is provided at the inlet end of the first pipeline 1. The first control valve 9 is used to control the flow rate of the gas, allowing the system to optimize the gas input under different working conditions, ensuring that the vacuum pump 5 operates in the best state, thereby improving the efficiency of the entire system.

[0038] In some embodiments, a fifth pipeline 10 is provided on the first pipeline 1, and a vacuum gauge 11 is provided on the fifth pipeline 10. By monitoring the vacuum level, the operator can promptly understand the pump's performance, detect faults or abnormalities early, and improve system reliability. A second control valve 12 is provided on either side of the vacuum gauge 11, connected to a third control valve 13 and the first pipeline 1. This allows the operator to flexibly adjust the gas flow rate when changes in the vacuum level are detected, helping to quickly respond to system changes and prevent excessive vacuum conditions, thereby avoiding damage to the vacuum pump, pipelines, and other components due to excessive vacuum pumping.

[0039] In some embodiments, a check valve 14 is provided on one end of the first pipeline 1 close to the vacuum pump 5 to prevent the gas from flowing back to the vacuum pump when the system stops or fails.

[0040] In some embodiments, an atmospheric ejector 15 is provided on the portion of the first pipeline 1 between the second control valve 12 and the third control valve 13, which uses atmospheric pressure to introduce external air into the system, which can provide additional airflow when the vacuum pump is working, thereby improving the fluidity of the gas and the suction capacity of the pump.

[0041] In some embodiments, the water level meter 16 is arranged on the steam-water separator 6, the water inlet pipe 17 and the water outlet pipe 18 are arranged on the steam-water separator 6, the water inlet control valve is arranged on the water inlet pipe 17, and the water outlet control valve is arranged on the water outlet pipe 18. The water level meter 16 can monitor the liquid level in the steam-water separator in real time, ensure that the water quantity of the water ring pump during the working process always meets the requirements, and help to improve the working efficiency and stability of the pump.

[0042] The first temperature sensor is arranged on the first pipeline 1 for detecting the ambient temperature, the second temperature sensor is arranged on the third pipeline 3 for detecting the temperature of the water input into the cooling unit 7, i.e. the backflow water temperature, the third temperature sensor is arranged on the fourth pipeline 4 for detecting the temperature of the cooling water, and the fourth control valve 19 is arranged on the fourth pipeline 4 for controlling the flow of the cooling water. The fourth temperature sensor is arranged on the vacuum pump 5 for detecting the working temperature of the vacuum pump 5. In this way, by monitoring the temperatures of the key parts in real time, potential problems can be found in time, so that corresponding measures can be taken to prevent equipment damage or failure and improve the safety of the system.

[0043] In some embodiments, as shown in Figure 4 The sixth pipeline 20 is arranged on the exhaust pipe 8 and connected to the first pipeline 1 through the sixth pipeline 20, and is generally connected between the first control valve 9 and the atmospheric ejector 15. The fifth control valve 21 is arranged on the sixth pipeline 20 close to one end of the exhaust pipe 8, so as to avoid that the gas discharged from the steam-water separator 6 affects the normal suction of the gas in the first pipeline 1 when the fifth control valve 21 is not opened. The seventh pipeline 22 is arranged between the steam-water separator 6 and the inlet end of the vacuum pump 5, and the sixth control valve 23 is arranged on the seventh pipeline 22 close to the steam-water separator 6.

[0044] It should be understood that in the water ring vacuum pump unit, each control valve is set as an on-off valve, a flow regulating valve, etc. according to the required function, and the valves in the drawings are only schematic. Each temperature sensor can use a temperature detector commonly used in the fields of pipelines, pump bodies, and valves.

[0045] As shown in Figure 5 Based on the above water ring vacuum pump unit, a control method is provided in the present specification, which comprises the following steps:

[0046] S1: Obtain the ambient temperature based on the first temperature sensor, and compare it with the pre-stored optimal working temperature of the vacuum pump 5 to generate the estimated temperature of the cooling water according to the difference between the two. If the ambient temperature is higher than the optimal working temperature, the temperature of the gas entering the vacuum pump will be higher, so the temperature of the cooling water needs to be lowered, and generally needs to be lowered below the optimal working temperature.

[0047] If the current ambient temperature is lower than the optimal working temperature, open the fifth control valve 21 and the sixth control valve 23, and adjust the opening of the fourth control valve 19 according to the actual working temperature obtained by the fourth temperature sensor to control the actual working temperature to approach the optimal working temperature.

[0048] When the actual working temperature is lower than the optimal working temperature, close the fourth control valve 19 and reduce the power of the cooling unit 7 or shut down the cooling unit 7.

[0049] S2: Based on the fourth temperature sensor, the actual working temperature of the vacuum pump 5 is obtained in real time, the deviation value from the optimal working temperature is calculated, and based on the current deviation value, the estimated temperature is progressively corrected according to the preset convergence coefficient until the absolute value of the deviation value does not exceed the allowed range; the preset convergence coefficient is used to avoid overshoot or oscillation. The allowed range, i.e. the deviation range, is set according to the actual working condition, such as ±1℃, which is a common industrial standard. For example, the initial estimated temperature is 38℃, but the actual working temperature is 48℃, the deviation is +8℃. According to the preset convergence coefficient, such as a convergence coefficient of 0.5, the correction amount is the deviation multiplied by the coefficient, i.e. 4℃. In this way, the cooling water temperature is reduced to 34℃, and the actual temperature is detected again until the deviation enters the allowed range.

[0050] Further, when aggressive correction is adopted to quickly eliminate large deviations. Among them, is the deviation of the actual working temperature and the optimal working temperature.

[0051] In the interval, proportional-integral adjustment is started to avoid overshoot and .

[0052] After , it is switched to a maintenance mode and only compensates for slight fluctuations.

[0053] This method only uses temperature sensors for feedback control, without the need for a large amount of calculation and strong real-time performance. Specifically, if the optimal temperature of the cooling water is calculated directly according to the optimal working temperature of the vacuum pump and the ambient temperature, the heat balance model needs to be involved. The heat generated by the vacuum pump needs to be taken away by the cooling water, and the ambient air sucked in will also bring in or take away heat, depending on the difference between the ambient temperature and the internal temperature of the pump. Therefore, the heat balance equation needs to consider the heat exchange of these two parts, and the flow rate of the intake air and the flow rate of the cooling liquid need to be considered.

[0054] When the ambient temperature is higher than the optimal working temperature, the ambient air will bring additional heat, and in this case, the cooling water temperature needs to be lower than the optimal working temperature to provide stronger cooling capacity to offset the heat brought by the ambient air. Conversely, when the ambient temperature is lower than the optimal working temperature, the ambient air may help cooling, and in this case, the cooling water temperature can be appropriately increased to reduce cooling energy consumption. Therefore, the determination of the optimal cooling water temperature should be a dynamic adjustment process, which is calculated in real time according to the change of the ambient temperature. This may need to establish a mathematical model to quantify the relationship between the ambient temperature and the cooling water temperature. This requires a large amount of data collection and data calculation.

[0055] In step S2, based on the backflow water temperature obtained by the second temperature sensor, the cooling power of the cooling unit 7 is adjusted so that the cooling water temperature approaches the estimated temperature, ensuring that the cooling unit 7 is quickly adjusted.

[0056] Based on the actual temperature of the cooling water obtained by the third temperature sensor, it is compared with the estimated temperature. If it exceeds the tolerance range, the cooling power of the cooling unit 7 is readjusted, and an additional calibration is performed to improve the reliability of the system.

[0057] S3: In the database, record the operation data set formed by the optimal working temperature, ambient temperature, estimated temperature, actual working temperature and deviation value in each adjustment process. When the deviation amount of the new data set is less than the same working condition historical record, perform data optimization replacement; wherein the same working condition is the same optimal working temperature and ambient temperature;

[0058] S4: When the water ring vacuum pump unit is running subsequently, the corresponding estimated temperature in the database is directly called based on the ambient temperature. If there is no same ambient temperature, the estimated temperature corresponding to the similar ambient temperature is used, and then steps S2 and S3 are repeatedly executed.

[0059] By using the above method, the continuous evolution of the control system is realized by establishing a working condition-temperature self-optimization database. The estimated temperature under the same working condition is dynamically calibrated and optimized at the data level, which not only ensures the reliable estimation ability at the initial stage of the new working condition, but also automatically selects better operation parameters through the deviation amount comparison mechanism to continuously converge and improve the temperature estimation accuracy of the system under repeated working conditions. After optimization, the temperature control deviation under the same working condition can be reduced, while avoiding the real-time calculation load required by traditional model predictive control, and both control accuracy and response speed are considered.

[0060] In view of the foregoing, it will be seen that the foregoing detailed description of the application is only illustrative in nature and not limiting. Although specific reference can be made to the examples contained herein, this has been done for illustrative purposes only, and is not intended to limit the application of the application in any way. Other ways of implementing the application will be apparent to those skilled in the art in view of the foregoing detailed description of the application. Accordingly, the true spirit and scope of the application is indicated by the appended claims, rather than by the foregoing description; and changes can be made to the details of the application without departing from the application as defined by the claims. Although there has been described above what are considered to be preferred embodiments of the present application, various modifications, alterations, and improvements will readily occur to those skilled in the art. It is the intention, therefore, to include all such modifications, alterations, and improvements within the scope of the present application. Accordingly, the application is not to be restricted, except in the spirit or scope of the appended claims.

[0061] Furthermore, it is to be understood that the application can be carried out by specifically tailored equipment, which is not described in detail in the foregoing description of the embodiments of the application. In the foregoing description of the embodiments of the application, for the purpose of brevity of description, various features of the application are grouped together in one embodiment, drawing or description of the application. This is done for the purpose of simplifying the present application. However, this is not to be interpreted that the groups of features are mandatory requirements. Skilled persons, once armed with this present application, will have no difficulty designing devices that incorporate only a subset of the features of the described embodiments. That is, the embodiments of the application can also be understood as integrated embodiments of the sub-embodiments. Each of the sub-embodiments is valid as long as it incorporates less than all features of the described embodiments.

[0062] Finally, it is to be understood that the embodiments of the application disclosed herein are illustrative of the principles of the present application. Other modifications that fall within the spirit and scope of the application can also be made. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the application is not to be limited to the details given herein, but can be modified within the scope and range of equivalents of the application.

Claims

1. A control method for a water ring vacuum pump unit, characterized in that: The water ring vacuum pump unit includes a first pipeline, a second pipeline, a third pipeline, a fourth pipeline, a vacuum pump, a steam-water separator, a cooling unit, a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and a control unit. The first pipeline is connected to the vacuum pump for inputting gas therein, the vacuum pump is connected to the steam-water separator through the second pipeline, the steam-water separator is connected to the cooling unit through the third pipeline, the steam-water separator is connected to the vacuum pump through the fourth pipeline, an exhaust pipe is provided on the steam-water separator, the steam-water separator is used to separate the water vapor transported by the vacuum pump, and the separated gas is discharged from the exhaust pipe, and the separated water is cooled by the cooling unit and transported back to the vacuum pump, the first temperature sensor is used to detect the ambient temperature, the second temperature sensor is used to detect the reflux water temperature, the third temperature sensor is used to detect the temperature of the cooling water, and the fourth temperature sensor is used to detect the operating temperature of the vacuum pump; The control method comprises the following steps: S1: obtaining the ambient temperature based on the first temperature sensor, comparing it with the pre-stored optimal operating temperature of the vacuum pump, and generating an estimated temperature of the cooling water based on the difference between the two; S2: obtaining the actual operating temperature of the vacuum pump in real time based on the fourth temperature sensor, calculating the deviation between the actual operating temperature and the optimal operating temperature, and progressively correcting the estimated temperature based on the current deviation according to a preset convergence coefficient until the absolute value of the deviation does not exceed an allowable range; In step S2, based on the return water temperature obtained by the second temperature sensor, the cooling power of the cooling unit is adjusted so that the cooling water temperature approaches the estimated temperature; Based on the actual temperature of the cooling water obtained by the third temperature sensor, the actual temperature is compared with the estimated temperature. If it exceeds the allowable range, the cooling power of the cooling unit is readjusted; S3: Recording the optimal operating temperature, ambient temperature, estimated temperature, actual operating temperature, and deviation values ​​during each adjustment process in a database to form an operational data set. When the deviation of the new data set is less than the historical record of the same operating condition, perform data optimization replacement; where the same operating condition refers to the same optimal operating temperature and ambient temperature; S4: When the water ring vacuum pump unit is subsequently operated, the corresponding estimated temperature in the database is directly called based on the ambient temperature.

2. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: The first pipeline is provided with a fifth pipeline, a vacuum meter is provided on the fifth pipeline, and a second control valve and a third control valve are respectively provided on both sides of the vacuum meter to connect with the first pipeline.

3. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: A check valve is provided on one end of the first pipeline close to the vacuum pump, and an atmospheric ejector is provided on the portion of the first pipeline between the second control valve and the third control valve.

4. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: The steam-water separator is provided with a liquid level gauge, a water inlet pipe and a drain pipe are provided on the steam-water separator, the water inlet pipe is provided with a water inlet control valve, and the drain pipe is provided with a drain control valve.

5. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: The inlet end of the first pipeline is provided with a first control valve for controlling the flow of gas, and the fourth pipeline is provided with a fourth control valve for controlling the flow of cooling water.

6. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: The exhaust pipe is provided with a sixth pipeline and is connected to the first pipeline through the sixth pipeline. A fifth control valve is provided at one end of the sixth pipeline close to the exhaust pipe.

7. The control method of a water ring vacuum pump unit according to claim 6, characterized in that: A seventh pipeline is provided between the steam-water separator and the inlet end of the vacuum pump, and a sixth control valve is provided on the seventh pipeline.

8. The control method of a water ring vacuum pump unit according to claim 1, characterized in that: If the current ambient temperature is lower than the optimal operating temperature, open the fifth control valve and the sixth control valve, and then adjust the opening of the fourth control valve according to the actual operating temperature obtained by the fourth temperature sensor to control the actual operating temperature to approach the optimal operating temperature; When the actual operating temperature is lower than the optimal operating temperature, the fourth control valve is closed, and the power of the cooling unit is reduced or the cooling unit is shut down.

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