A pressure meter cleaning system and method

Abstract

The present invention relates to effective cleaning equipment and cleaning methods for pressure measuring instruments, and discloses a pressure measuring instrument cleaning system and method, wherein the cleaning system includes an execution device, a measuring unit, auxiliary equipment, a circulation device and a controller. Aiming at the defects of the existing pressure measuring instrument cleaning technology, such as time-consuming and oil residue, the present invention processes the data of the flow sensor and the density meter through PLC, realizes the real-time control of the execution device by the controller, and displays the cleaning progress on the host computer; uses clean water as the cleaning medium, and realizes the recycling of the cleaning medium through the circulation device, which not only greatly reduces the cleaning cost, but also ensures the cleaning efficiency of the system; uses the switching of the manual / automatic mode of PLC to improve the automation and reliability of the system, and lays a good foundation for the normal use of subsequent instruments.

Description

Technical Field

[0001] The invention relates to the technical field of instrument cleaning, and in particular to a pressure meter cleaning system and method. Background Art

[0002] Pressure gauges are measuring instruments that use elastic elements as sensitive elements to measure gas or liquid pressure. Pressure gauges are generally installed on pipelines for pressure detection. After a long period of use, due to the harsh working environment on site, a large amount of oil will accumulate in the cavity of the pressure gauge, corroding the cavity of the gauge, causing defects in the spring tube and destroying its measurement accuracy. Oil stains that are not cleaned in time mainly damage the metal parts of the stop valve, pressure pump, etc., causing them to oxidize and lose their sealing and pressure-increasing properties.

[0003] As the end effector of the cleaning device, the nozzle is an important component of the cleaning device. At present, the nozzles widely used in cleaning devices include fan-shaped, cone-shaped, air atomizing and flat nozzles, but these nozzles often have problems such as small spray angle, insufficient coverage and pressure loss. These problems are mutually restricted and interrelated, making the selection of nozzles very difficult and failing to achieve the ideal spray cleaning effect.

[0004] At present, the method used by various testing institutes and metrology institutes to solve the contamination problem of pressure instruments is usually to place the instrument upright in an oil leaker to allow the oil to slowly flow out naturally. The disadvantage is that it is not only very time-consuming, but also unable to clean the stains attached to the pressure chamber of the instrument being tested, resulting in the need to replace the pressurizing valve and stop valve of the liquid piston detection equipment within one year, affecting the detection efficiency and causing great inconvenience in production maintenance. Summary of the invention

[0005] The present invention aims at the deficiencies in the prior art and provides a pressure meter cleaning system and method that overcomes the above problems. The present invention realizes real-time monitoring and control of the flow rate of the injected cleaning liquid through a flow sensor, so that the pressure meter with different oil pollution levels can ensure high cleaning efficiency; the droplet density of the cleaning liquid in the meter is measured by a density meter, and the data is transmitted to the PLC, so that the control system can control the actuator in real time, and the cleaning progress is displayed in real time through the upper computer matched with the PLC; the high-pressure water jet cleaning is selected, which reduces the cleaning cost and solves the problem of oil residue during the cleaning of the pressure meter, thereby improving the efficiency and practicality of the cleaning of the pressure meter.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A pressure meter cleaning system comprises a circulation device, an execution device, auxiliary equipment, a measuring unit and a controller; the circulation device collects and purifies waste liquid and provides cleaning liquid for the execution device; the execution device receives a control signal from the controller, cleans the pressure meter, and inputs the waste liquid into the circulation device; the auxiliary equipment assists the execution of the execution device; the measuring unit measures the execution status data of the execution device through a density meter and a flow sensor and feeds back the real-time measurement results to the controller; the controller comprises a host computer and a PLC, the PLC is electrically connected to the measuring unit, the execution device and the host computer, the PLC transmits the data measured by the measuring unit in real time to the host computer, and sends a control signal to the execution device.

[0008] To optimize the above technical solutions, the specific measures taken also include:

[0009] Furthermore, the actuator includes a pressure unit, a high-pressure hose and a cleaning nozzle; the pressure unit includes a water pump, a diesel engine and a booster pump; the water pump extracts the cleaning liquid in the circulation device and delivers it to the booster pump; the booster pump pressurizes the cleaning liquid and delivers it to the high-pressure hose; the high-pressure hose is connected to the cleaning nozzle; the diesel engine drives the water pump and the booster pump to work; a flow valve is installed at the inlet of the booster pump, and a pressure regulating valve is installed at the outlet of the booster pump; the flow valve and the pressure regulating valve are connected to the PLC via a data line; the flow valve and the pressure regulating valve adjust the valve opening and closing size according to the control signal sent by the PLC, and the opening and closing size of the flow valve and the pressure regulating valve is linearly related to the current size of the control signal.

[0010] Furthermore, the host computer performs Kalman filtering and data fusion on the data measured in real time by the measuring unit through the Kalman filtering algorithm, and displays the data measured in real time by the measuring unit; the PLC sends a control signal to the execution device according to the fused data; the controller has a manual mode and an automatic mode; when the pressure gauge cleaning system is debugged and maintained, the controller runs in the manual mode, and when the pressure gauge cleaning system is stable, the controller switches to the automatic mode.

[0011] Furthermore, the cleaning nozzle includes a support frame, an outer shell, a water injection port, a rotating rod, a motor and a jet tube; the cleaning nozzle adopts a dual jet mode; the water injection port is connected to the outlet of the high-pressure hose; the motor rotates and moves along the inner wall of the outer shell, while driving the rotating rod to rotate; the end of the rotating rod is fixedly connected to the end of the support frame by bolts; the motor secondary pressurizes the water flow entering the water injection port during the process of moving along the inner wall of the outer shell, and presses it into the jet tube for injection; the motor drives the rotation of the jet tube during the rotation process; the reaction force generated by the jet ejected by the cleaning nozzle through the jet tube moves along the inner wall of the pressure measuring instrument.

[0012] Furthermore, the auxiliary equipment includes a hose feeder and a pressure gauge; the high-pressure hose passes through the hose feeder; the hose feeder is provided with equally spaced circular protrusions, the diameter of the circular protrusions is larger than the diameter of the high-pressure hose, and is used to control the feeding speed of the high-pressure hose along the inner wall of the pressure measuring instrument; the pressure gauge is fixedly connected to the inner wall of the hose feeder, and the pressure gauge is electrically connected to the PLC.

[0013] Furthermore, the flow sensor monitors the jet flow rate from the cleaning nozzle, and the density meter measures the density of the droplets inside the pressure meter; the flow sensor and the density meter transmit the measured flow data and density data to the PLC in real time.

[0014] Furthermore, the circulation device includes a wastewater tank, a sedimentation tank and a water tank; the wastewater tank receives the waste liquid generated by cleaning the nozzle and the pressure meter, and transports it to the sedimentation tank; the sedimentation tank filters and precipitates the waste liquid, and returns clean water to the water tank; the water tank is connected to an external water source and has a drainage pipe; the water pump extracts water from the water tank.

[0015] Further, the PLC includes an input module and an output module; the input module includes a water pump start button, a water pump stop button, a flow monitoring button, a density monitoring button, a manual / automatic mode switching button, a host computer start button and a host computer stop button; the output module includes a water pump start / stop signal port, a host computer start / stop signal port, a flow alarm light, a flow display signal port, a density display signal port and a water pump start status light;

[0016] The PLC has a self-checking function; the PLC automatically checks whether the pressure meter cleaning system is normal by judging the flow data and density data measured by the flow sensor and the density meter; in the self-checking state, the pressure device blocks the high-pressure hose; after the self-checking is completed, the PLC sends a start command to the pressure meter cleaning system, and the pressure device stops applying pressure;

[0017] When the flow data measured by the flow sensor exceeds the threshold, the PLC starts the flow alarm light and automatically stops the press unit.

[0018] Furthermore, the host computer performs Kalman filtering and data fusion on the data measured in real time by the measurement unit through a Kalman filtering algorithm, as follows:

[0019] The host computer receives the data from the measuring unit; pre-processes the initial value of the flow data; uses the density data measured by the density meter to perform error compensation on the pre-processed flow data; performs Kalman filtering on the compensated flow data and the original density data measured by the density meter to obtain the optimal estimated flow data and density data; splices and fuses the optimal estimated flow data and density data to generate new pressure regulating valve and flow valve control instructions; the optimal estimated flow data is returned to the data pre-processing and participates in the next group of Kalman fusion filter processing cycles.

[0020] The present invention also proposes a pressure meter cleaning method using the pressure meter cleaning system as described above, comprising the following steps:

[0021] S1: Turn on the main switch of PLC, start the host computer through PLC, press the water pump start button, and let the water pump run for a while until it works stably and the water pump status light is on;

[0022] S2: PLC self-check, PLC controls the pressure device to block the high-pressure hose, and waits for the PLC self-check to end;

[0023] S3: Select PLC manual mode, set the cleaning time through the host computer, and manually adjust the high-pressure hose so that the cleaning nozzle is located at the bottom center of the pressure gauge;

[0024] S4: Select the automatic mode, the upper computer will display the flow data and cleaning progress in real time. When the cleaning nozzle cleans from the bottom of the pressure gauge to the opening, if the cleaning progress is not completed, select the manual mode to aim the cleaning nozzle at the bottom again to start the second cleaning. If the flow data exceeds the threshold during the cleaning process, the PLC will stop the pump and light up the flow alarm status light.

[0025] S5: Repeat steps S3 and S4. After the cleaning is completed, the PLC turns off all cleaning equipment and enters the standby state.

[0026] The beneficial effects of the present invention are:

[0027] 1. Compared with traditional chemical cleaning, this device uses water as the cleaning medium, so there is no need to post-treat the cleaning wastewater after cleaning, which reduces a lot of unnecessary expenses;

[0028] 2. PLC is used as the control system, and Kalman fusion filtering is performed on the sensor data in the upper computer. The automation level is high, which improves the cleaning efficiency of the pressure meter cleaning system to a considerable extent, saves a lot of manpower and material resources, and ensures the cleanliness and repeatability of the cleaning;

[0029] 3. The nozzle adopts a double jet mode, and the jet tube at the end of the nozzle can rotate to achieve cleaning without dead angles;

[0030] 4. In the self-check state, the high-pressure hose is blocked by the pressure device to ensure the safety of the operator;

[0031] 5. It increases the service life of pressure measuring instruments and lays a good foundation for the normal use of subsequent instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 It is a principle block diagram of the present invention;

[0034] Figure 3a This is a structural diagram of the cleaning nozzle;

[0035] Figure 3b This is a three-dimensional diagram of the appearance of the cleaning nozzle;

[0036] Figure 4 This is the structural diagram of each module of PLC;

[0037] Figure 5 This is the flow chart of the Kalman filter algorithm;

[0038] The reference numerals are as follows: A, circulation device; B, actuator; C, auxiliary equipment; D, measuring unit; E, controller; 1, pressure unit; 2, high pressure hose; 3, cleaning nozzle; 4, pressure meter; 5, density meter; 6, flow sensor; 7, hose feeder; 8, pressure device; 9, waste water tank; 10, sedimentation tank; 11, water tank; 12, PLC; 13, host computer; 14, water pump; 15, diesel engine; 16, booster pump; 17, flow valve; 18, pressure regulating valve; 19, water inlet pipe; 20, water return pipe; 21, drainage pipe;

[0039] 31. Support frame; 32. Housing; 33. Water inlet; 34. Rotating rod; 35. Motor; 36. Jet tube;

[0040] 121. Input module; 122. Output module. DETAILED DESCRIPTION

[0041] The present invention will now be described in further detail with reference to the accompanying drawings.

[0042] In one embodiment, the present invention provides a pressure meter cleaning system. The actual structure and connection relationship of the pressure meter cleaning system are as follows: Figure 1 As shown, the principle block diagram of the pressure meter cleaning system is as follows Figure 2As shown, the pressure meter cleaning system includes a circulation device A, an execution device B, an auxiliary device C, a measuring unit D and a controller E. The circulation device A includes a wastewater tank 9, a sedimentation tank 10 and a water tank 11; the execution device B includes a pressure unit 1, a high-pressure hose 2 and a cleaning nozzle 3; the pressure unit 1 is the main means to pressurize the cleaning liquid flow, which includes a water pump 14, a diesel engine 15 and a booster pump 16. The control system E issues a start control command, and the diesel engine 15 drives the liquid in the water tank 11 to be pumped out by the water pump 14 and then enters the booster pump 16. The booster pump 16 pressurizes the liquid flow at normal pressure to a specified pressure level and delivers the high-pressure water flow to the high-pressure hose 2. Since the diesel drive engine is usually more powerful than the electric drive engine, the pressure unit 1 can achieve a better pumping and pressurizing effect.

[0043] The booster pump 16 and the water pump 14 in the pressure unit 1 are preferably hot water pumps. When the pressure meter 4 has too much oil and high viscosity, it is necessary to heat the clean water to between 50°C and 70°C during the cleaning process to achieve a better cleaning effect. The hot water pump is a mechanical seal with good sealing effect. If a cold water pump is used, it is easy to cause water leakage due to packing seal and temperature problems.

[0044] The medium water has the disadvantages of excessive surface tension and poor affinity for oily dirt. During the cleaning process, alkali, soap or synthetic detergent can be added to the water to enhance the affinity for oily dirt, and an appropriate amount of surfactant can be added to reduce the surface tension of water, thereby enhancing the wetting ability of the dirt to be cleaned and improving the cleaning effect of water.

[0045] One end of the high-pressure hose 2 is connected to the booster pump 16, and the other end is connected to the cleaning nozzle 3, and the cleaning nozzle 3 has a double jet pipe arranged side by side. The high-pressure hose 2 is made of reinforced plastic or high-density fiber. The high-pressure hose 2 mainly plays the role of conveying fluid medium, and at the same time ensures that the high-pressure jet is not leaked to protect the construction personnel. The inner diameter of the high-pressure hose 2 is selected to be moderate.

[0046] The auxiliary equipment C includes a hose feeder 7 and a pressure device 8. The hose feeder 7 is provided with equally spaced circular protrusions, the diameter of which is larger than the diameter of the high-pressure hose 2, which plays a certain friction role, controls the feeding speed of the high-pressure hose 2 along the pipeline direction, and ensures the balance of the cleaning effect. The pressure device 8 is fixedly connected to the inner wall of the hose feeder 7. The pressure device 8 uses a spiral supercharger and is symmetrically distributed along the horizontal axis of the hose feeder 7. With the cooperation of the auxiliary equipment C, the cleaning nozzle 3 can move along the inner wall of the pressure meter 4, and the forward reaction force exerted by the jet on the inner wall of the pressure meter 4 drives the cleaning nozzle 3 to move in the lateral direction of the pressure meter 4, and at the same time achieves the purpose of descaling the inner wall of the pipeline of the pressure meter 4. The cleaning dirty liquid in the pressure meter 4 is discharged into the circulation device A through the pipeline. The dirty liquid passes through the wastewater tank 9 and the sedimentation tank 10 in turn and is injected into the large-capacity water tank 11, realizing the recycling and regeneration of the cleaning liquid in the pressure meter cleaning system.

[0047] like Figure 3a As shown, the cleaning nozzle 3 includes a support frame 31, a shell 32, a water injection port 33, a rotating rod 34, a motor 35 and a jet tube 36. The cleaning nozzle 3 adopts a dual jet mode, and the rotation of the jet tube 36 at the end of the nozzle can be realized by water injection. The water injection port 33 is connected to the outlet of the high-pressure hose 2, and the motor 35 rotates and moves up and down along the inner wall of the shell 32, while driving the rotation of the rotating rod 34; the end of the rotating rod 34 is fixedly connected to the end of the support frame 31 by bolts to ensure the stability of the rotation of the rotating rod 34. During the up and down movement, the motor 35 pressurizes the water flow entering the water injection port 33 for a second time, and presses it into the jet tubes 36 distributed at the left and right ends for spraying. Since the motor 35 works in a liquid environment, a waterproof motor needs to be selected. If the feeding of the cleaning nozzle 3 is unstable, the support frame 31 can be connected to a fixed structure to form sliding friction to ensure the feeding stability; the motor 35 drives the rotation of the jet tube 36 during the rotation process, thereby realizing the cleaning of the pressure meter 4 without dead angles and ensuring the cleaning effect.

[0048] The controller E includes a host computer 13 and a PLC 12. The PLC 12 is controlled by a programmable logic controller. The controller E is divided into two modes: manual mode and automatic mode. When the pressure meter cleaning system is debugged and maintained, the controller E runs in the manual mode and switches to the automatic mode when the system is stable.

[0049] The measuring unit D includes a flow sensor 6 and a density meter 5. The flow sensor 6 is responsible for monitoring the size of the jet flow, and the density meter 5 is responsible for measuring the size of the droplet density inside the pressure meter 4. Through the real-time measurement of the density meter 5, the proportion of oil in the water can be obtained. The lower the proportion, the higher the cleanliness. The measuring unit D transmits the monitored data to the PLC 12 in real time for analysis and calculation, and realizes the real-time display of the flow rate of the pressure meter flushing system and the cleaning progress. In automatic mode, the PLC 12 can issue control commands to the flow valve 17 and the pressure regulating valve 18 according to the flow data and density data to complete the efficient cleaning of the pressure meter 4.

[0050] like Figure 4 As shown, PLC12 includes an input module 121 and an output module 122. The input module 121 includes a water pump start button, a water pump stop button, a flow monitoring button, a density monitoring button, a manual / automatic mode switching button, a host computer start button, and a host computer stop button; the output module 122 includes a water pump start / stop signal port, a host computer start / stop signal port, a flow alarm light, a flow display signal port, a density display signal port, and a water pump start status light.

[0051] PLC12 has a self-checking function, which can automatically check whether the system status is normal by judging the flow data and density data; the pressure device 8 is electrically connected to PLC12. In the self-checking state, the pressure device 8 applies pressure to the high-pressure hose 2, and the high-pressure hose 2 is blocked by the pressure device 8 to prevent the fault from causing the jet to be ejected prematurely and injure the operator, thereby ensuring the safety of the operator. After the self-check is completed, when PLC12 initiates the start command, the pressure device 8 stops applying pressure to allow the high-pressure jet to pass through. The injection flow in the pressure meter 4 is monitored by the flow sensor 6, and PLC12 performs real-time control based on the monitored flow data. When the flow exceeds a certain threshold, the flow alarm light will be activated and the press unit 1 will be automatically stopped.

[0052] Since the measuring unit D is impacted by the jet, high-frequency noise will be generated, and the noise will change over time, resulting in large errors in the flow data and density data received by the host computer 13, affecting the measurement accuracy and cleaning progress. Therefore, a Kalman filter algorithm is set in the host computer to filter and fuse the data uploaded by the density meter 5 and the flow sensor 6. While eliminating the noise, the opening and closing size of the pressure regulating valve 18 and the flow valve 17 are controlled according to the fused data to achieve automatic control of the jet pressure and flow.

[0053] The flowchart of the Kalman filter algorithm is as follows Figure 5As shown, after receiving the data from the measuring unit D, the host computer 13 pre-processes the initial value of the flow data, uses the density data measured by the density meter 5 to perform error compensation on the processed flow data, performs Kalman filtering on the compensated flow data and the original density data measured by the density meter 5, obtains the optimal estimated flow data and density data, splices and fuses the optimal estimated flow data and density data, generates new pressure regulating valve and flow valve control instructions, realizes the jet changes with the change of cleaning progress, and further improves the cleaning efficiency. The optimal estimated flow data will participate in the next group of Kalman fusion filter processing cycles.

[0054] In another embodiment, the present invention provides a pressure meter cleaning method using the pressure meter cleaning system as described above, specifically comprising the following steps:

[0055] S1: Turn on the main switch of PLC, start the host computer through PLC, press the water pump start button, and let the water pump run for a while until it works stably and the water pump status light is on;

[0056] S2: PLC self-check, PLC controls the pressure device to block the high-pressure hose, and waits for the PLC self-check to end;

[0057] S3: Select PLC manual mode, set the cleaning time through the host computer, and manually adjust the high-pressure hose so that the cleaning nozzle is located at the bottom center of the pressure gauge;

[0058] S4: Select the automatic mode, the upper computer will display the flow data and cleaning progress in real time. When the cleaning nozzle cleans from the bottom of the pressure gauge to the opening, if the cleaning progress is not completed, select the manual mode to aim the cleaning nozzle at the bottom again to start the second cleaning. If the flow data exceeds the threshold during the cleaning process, the PLC will stop the pump and light up the flow alarm status light.

[0059] S5: Repeat steps S3 and S4. After the cleaning is completed, the PLC turns off all cleaning equipment and enters the standby state.

[0060] By determining the oil stain thickness and cleaning cycle of the pressure gauge 4, a pressure gauge cleaning system and method with a higher degree of automation can be further developed to improve the cleaning efficiency of the pressure gauge 4 and maintain the normal operation of the pressure gauge 4 in subsequent work.

[0061] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0062] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A pressure meter cleaning system, characterized in that: The invention comprises a circulation device (A), an execution device (B), an auxiliary device (C), a measuring unit (D) and a controller (E); the circulation device (A) collects and purifies waste liquid and provides clean liquid for the execution device (B); the execution device (B) receives a control signal from the controller (E), cleans a pressure meter (4), and inputs waste liquid into the circulation device (A); the auxiliary device (C) assists the execution of the execution device (B); the measuring unit (D) measures the execution status data of the execution device (B) through a density meter (5) and a flow sensor (6) and feeds back the real-time measurement result to the controller (E); the controller (E) comprises a host computer (13) and a PLC (12); the PLC (12) is electrically connected to the measuring unit (D), the execution device (B) and the host computer (13); the PLC (12) transmits the real-time measurement data of the measuring unit (D) to the host computer (13) and sends a control signal to the execution device (B); The actuator (B) comprises a pressure unit (1), a high-pressure hose (2) and a cleaning nozzle (3); the pressure unit (1) comprises a water pump (14), a diesel engine (15) and a booster pump (16); the water pump (14) extracts cleaning liquid from the circulation device (A) and delivers it to the booster pump (16); the booster pump (16) pressurizes the cleaning liquid and delivers it to the high-pressure hose (2); the high-pressure hose (2) is connected to the cleaning nozzle (3); the diesel engine (15) drives the water pump (14) to pump cleaning liquid from the circulation device (A) and delivers it to the booster pump (16); 4) and the booster pump (16); a flow valve (17) is installed at the inlet of the booster pump (16), and a pressure regulating valve (18) is installed at the outlet of the booster pump (16); the flow valve (17) and the pressure regulating valve (18) are connected to the PLC (12) via a data line; the flow valve (17) and the pressure regulating valve (18) adjust the opening and closing size of the valve according to the control signal sent by the PLC (12), and the opening and closing size of the flow valve (17) and the pressure regulating valve (18) is linearly related to the current size of the control signal; The auxiliary equipment (C) comprises a hose feeder (7) and a pressure device (8); the high-pressure hose (2) passes through the hose feeder (7); the hose feeder (7) is provided with equally spaced circular protrusions, the diameter of the circular protrusions being larger than the diameter of the high-pressure hose (2) and being used to control the feeding speed of the high-pressure hose (2) along the inner wall of the pressure meter (4); the pressure device (8) is fixedly connected to the inner wall of the hose feeder (7), and the pressure device (8) is electrically connected to the PLC (12); The PLC (12) comprises an input module (121) and an output module (122); the input module (121) comprises a water pump start button, a water pump stop button, a flow monitoring button, a density monitoring button, a manual / automatic mode switching button, a host computer start button, and a host computer stop button; the output module (122) comprises a water pump start / stop signal port, a host computer start / stop signal port, a flow alarm light, a flow display signal port, a density display signal port, and a water pump start status light; The PLC (12) has a self-checking function; the PLC (12) automatically checks whether the pressure meter cleaning system is normal by judging the flow data and density data measured by the flow sensor (6) and the density meter (5); in the self-checking state, the pressure device (8) blocks the high-pressure hose (2); after the self-checking is completed, the PLC (12) initiates a start command to the pressure meter cleaning system, and the pressure device (8) stops applying pressure; When the flow data measured by the flow sensor (6) exceeds the threshold value, the PLC (12) activates the flow alarm light and automatically stops the press unit (1).

2. The pressure meter cleaning system according to claim 1, characterized in that: The host computer (13) performs Kalman filtering and data fusion on the data measured in real time by the measuring unit (D) through a Kalman filtering algorithm, and displays the data measured in real time by the measuring unit (D); the PLC (13) sends a control signal to the execution device (D) according to the fused data; the controller (E) has a manual mode and an automatic mode; when the pressure meter cleaning system is debugged and maintained, the controller (E) operates in the manual mode, and when the pressure meter cleaning system is stable, the controller (E) switches to the automatic mode.

3. The pressure meter cleaning system according to claim 1, characterized in that: The cleaning nozzle (3) comprises a support frame (31), a housing (32), a water injection port (33), a rotating rod (34), a motor (35) and a jet tube (36); the cleaning nozzle (3) adopts a dual jet mode; the water injection port (33) is connected to the outlet of the high-pressure hose (2); the motor (35) rotates and moves along the inner wall of the housing (32), while driving the rotating rod (34) to rotate; the end of the rotating rod (34) is fixedly connected to the end of the support frame (31) by bolts; the motor (35) performs secondary pressurization on the water flow entering from the water injection port (33) during the process of moving along the inner wall of the housing (32), and presses the water flow into the jet tube (36) for spraying; the motor (35) drives the jet tube (36) to rotate during the process of rotating; the reaction force generated by the jet sprayed by the cleaning nozzle (3) through the jet tube (36) moves along the inner wall of the pressure meter (4).

4. The pressure meter cleaning system according to claim 1, characterized in that: The flow sensor (6) monitors the flow rate of the jet ejected from the cleaning nozzle (3), and the density meter (5) measures the density of the droplets inside the pressure meter (4); the flow sensor (6) and the density meter (5) transmit the measured flow data and density data to the PLC (12) in real time.

5. The pressure meter cleaning system according to claim 1, characterized in that: The circulation device (A) comprises a wastewater tank (9), a sedimentation tank (10) and a water tank (11); the wastewater tank (9) receives waste liquid generated by cleaning the nozzle (3) and the pressure meter (4), and transports it to the sedimentation tank (10); the sedimentation tank (10) filters and precipitates the waste liquid, and returns clean water to the water tank (11); the water tank (11) is connected to an external water source and is provided with a drainage pipe; the water pump (14) extracts water from the water tank (11).

6. The pressure meter cleaning system according to claim 2, characterized in that: The host computer (13) performs Kalman filtering and data fusion on the data measured in real time by the measurement unit (D) through a Kalman filtering algorithm, as follows: The host computer (13) receives data from the measuring unit (D); pre-processes the initial value of the flow data; and uses the density data measured by the density meter (5) to perform error compensation on the pre-processed flow data; The compensated flow data and the original density data measured by the density meter (5) are subjected to Kalman filtering to obtain the optimal estimated flow data and density data; the optimal estimated flow data and density data are spliced ​​and fused to generate new pressure regulating valve and flow valve control instructions; the optimal estimated flow data is returned to the data preprocessing and participates in the next group of Kalman fusion filter processing cycles.

7. A pressure meter cleaning method using the pressure meter cleaning system according to claim 1, characterized in that: The following steps are involved: S1: Turn on the PLC main switch, start the host computer through the PLC, press the water pump start button, and let the water pump run for a while until it works stably and the water pump status light is on; S2: PLC self-check, PLC controls the pressure device to block the high-pressure hose, and waits for the PLC self-check to end; S3: Select PLC manual mode, set the cleaning time through the host computer, and manually adjust the high-pressure hose so that the cleaning nozzle is located at the bottom center of the pressure gauge; S4: Select the automatic mode, the upper computer will display the flow data and cleaning progress in real time. When the cleaning nozzle cleans from the bottom of the pressure gauge to the opening, if the cleaning progress is not completed, select the manual mode to aim the cleaning nozzle at the bottom again to start the second cleaning. If the flow data exceeds the threshold during the cleaning process, the PLC will stop the pump and light up the flow alarm status light. S5: Repeat steps S3 and S4. After the cleaning is completed, the PLC turns off all cleaning equipment and enters the standby state.

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