CN101303038A - An intelligent exhaust system for the low-pressure end of the hydraulic system pump - Google Patents

Abstract

The invention discloses an intelligent exhaust system used for a low-pressure end in front of a pump in a hydraulic pressure system, which comprises the pump and an air vessel, wherein, a manual air outlet is arranged at the low-pressure end in front of the pump, and the air vessel is arranged at the postion higher than the pump and lower than a liquid storage tank. The air vessel is connected with the manual air outlet and provided with an air outlet while the air outlet is connected with an exhaust valve. The air vessel is internally provided with a high and low liquid level sensor, and the exhaust valve and the high and low liquid level sensor are connected with a control module while the control module is connected with a monitoring indication module and a failure indication module. The technical proposal of the invention utilizes the principle that air specific weight is smaller than liquid specific weight to intensively collect the air in a low-pressure loop in front of the pump into the air vessel and automatically exhaust according to the condition of air reserve, thus avoiding the blind and regular manual exhaust, greatly reducing the contact frequency of workers with high risk equipment and high risk environments and greatly reducing the rate of serious accident.

Description

An intelligent exhaust system for the low-pressure end of the hydraulic system pump

technical field

The invention belongs to the technical field of hydraulic pressure, in particular to an intelligent exhaust system used for exhausting the low-pressure circuit before the pump.

Background technique

In the hydraulic system, the hydraulic medium in the low-pressure fluid storage tank is often in contact with air. When the hydraulic medium flows in the hydraulic circuit, a small amount of air is often brought in, especially when the hydraulic pump is circulating, it is easier to bring air into the hydraulic medium. , This will cause gas-liquid miscibility in the high-pressure circuit of the hydraulic pump, which will easily make the pressure of the high-pressure circuit unstable, resulting in unstable movement of the power mechanism, and may cause serious accidents in important systems that require stability, safety and reliability. Such as high-voltage power system, petrochemical high-risk environment system, etc. In the prior art, a manual exhaust port is mostly set at the high position of the low-pressure liquid inlet end of the hydraulic pump, which is manually inspected and exhausted regularly, which has problems such as poor safety and reliability. The following takes the hydraulic mechanism of the high-voltage power system as an example to illustrate the existing problems.

Circuit breakers in power systems are generally driven by hydraulic mechanisms, especially some imported high-voltage circuit breakers, which are currently widely used in power systems across the country. From the perspective of overall use, they are high-quality products. But the best products are not perfect. From the use in recent years, it has been found that the hydraulic mechanism of 500KV 3AT and 220KV3AQ1 circuit breakers occasionally has abnormal pressure defects. The exposed phenomenon is mainly caused by frequent pressure or unsuccessful pressure building. Suppression overtime alarm, there is a hidden danger of accidents.

During the actual operation of 500KV 3AT and 220KV 3AQ1 circuit breakers, it often happens that the oil pump runs continuously or pumps frequently. At this time, the oil pressure of the switch hydraulic system will be maintained at a relatively low pressure level, and the power supply of the oil pump will be turned off. After that, the oil pressure value of the hydraulic system can remain unchanged. This situation usually occurs in the early morning of the season with a large temperature difference, or when the equipment is combined with maintenance, and the motor power is cut off for more than 24 hours and then resumes operation. After on-site inspection and comprehensive analysis of the treatment situation: the root cause of the problem is that there is air in the oil pump piston, and the oil pump can also be heard from the sound. The air in the oil pump piston is mainly due to the slight leakage of the hydraulic system after the high-pressure switch has been running for a period of time, resulting in the accumulation of a certain amount of gas in the low-pressure part of the oil pump and part of the high-pressure oil system (energy storage tank and high-pressure oil cylinder). Due to the existence of gas, the oil pump cannot effectively output the hydraulic oil from the low-pressure part to the high-pressure part, and the oil pump continues to run, but the oil pressure cannot rise. Problems such as electrical failure (contactor burnout) or mechanical failure (oil pump damage) occur.

The high-voltage circuit breaker has the defect that the oil pump runs continuously or frequently pumps and the oil pressure cannot be increased, which will pose a great threat to the normal operation of the circuit breaker. If the defect continues to occur and is not dealt with, or the maintenance personnel do not stop the power to deal with the defect, it may be The outage of the circuit breaker will directly affect the reliable operation of the power grid and the power outage of the majority of users, and will also have a very adverse impact on the reliability indicators of the power transmission and transformation facilities of the power grid enterprises.

The treatment method for this type of defect is to effectively exhaust the hydraulic circuit, and the oil pump can only operate normally after the hydraulic oil is refilled into the oil pump piston. At present, there are two ways to deal with it. One is to check the equipment irregularly. In the case of no power failure, manually exhaust all hydraulic mechanism oil pumps every year. The steps are: turn off the motor power switch of the oil pump circuit; turn off the oil pump Loosen the exhaust screw on the motor and keep it loose. When the discharged oil has no air bubbles, tighten the exhaust screw; turn on the motor power switch.

The work is relatively simple, the workload is not large, and the equipment does not need to be powered off. The purpose is to eliminate part of the gas in the hydraulic circuit, so that the time for defects to be extended. However, this method has the following main problems: 1) There is a large potential safety hazard during work. If it touches other components inside the switch mechanism box during work, it will cause misoperation of the switch, which may cause large-scale power outages; 2) Artificial Exhausting consumes a lot of maintenance effort, and cannot completely eliminate the defect of pressing overtime, but only prolongs the occurrence time of the defect. In fact, the defect of pressing overtime often occurs just one month after manual exhausting.

The second treatment method is: stop the equipment and exhaust the hydraulic system. The steps are:

a) Exhaust the oil pump of the circuit breaker: turn off the motor power of the oil pump circuit, discharge the oil pressure of the hydraulic system to zero pressure; loosen the exhaust plug on the oil pump and keep it in the loose state, when the discharged oil When there is no air bubble, tighten the exhaust plug; close the motor power switch, and let the oil pump idle for about 5 minutes (at this time, the pressure relief bolt remains in the pressure relief state); repeat the above steps 2 to 3 times, exhaust, and the oil pump idles until the pump No gas is discharged from the body; close the exhaust bolt of the oil pump, turn on the power supply of the motor, and check the pre-charge pressure of the gas in the nitrogen storage tank; after the pressure is stored to normal pressure, open and close the circuit breaker 2 to 3 times; release the pressure, and check the inside of the oil pump again The presence or absence of gas.

b) Relieve the pressure of the hydraulic system, exhaust the energy storage cylinder, hydraulic cylinder and hydraulic locker (the oil pump is idling), until the hydraulic oil flowing out of the cylinder energy storage cylinder exhaust port and other related exhaust ports has no air bubbles.

C) After exhausting, check the nitrogen pre-charge pressure of the nitrogen energy storage cylinder, the energy storage time from zero pressure, the pressure after the on-off operation, and the re-energy storage time.

This work is relatively complicated, but the gas in the hydraulic circuit can be basically exhausted, but the maintenance time is not long, and according to actual experience, it can only be maintained for one year at most. Although the exhaust effect of this method is better, it needs power outage treatment. For electric power equipment, frequent power outages will have a serious impact on society and the power grid system, and in actual work, the technical requirements are high and the operation is complicated. The exhaust needs to be connected by oil pipes. Improper connection may cause a small amount of hydraulic oil to flow out of the oil tank. Therefore, it is necessary to prepare a small amount of hydraulic oil of the same label and the manufacturer as a supplement. At the same time, it should be noted that the plugging screw of the exhaust port is made of copper material, which is easy to twist off.

Contents of the invention

In order to effectively, thoroughly and conveniently solve the problem of equipment failure caused by gas generated at the low-pressure end in front of the pump in the hydraulic system and ensure the normal operation of the hydraulic system, the purpose of this invention is to provide an intelligent exhaust system for the low-pressure end of the pump in the hydraulic system. The air device is set at a position higher than the pump and lower than the liquid storage tank, and is connected to the low-pressure end of the pump. Using the principle that gas is lighter than liquid, the gas is introduced into the exhaust device, and the air in the low-pressure circuit can be collected concentratedly and discharged. Automatic exhausting according to the situation, avoiding manual and regular blind manual exhausting, greatly reducing the number of times the staff contact high-risk equipment and high-risk environments, can greatly reduce the accident rate of major accidents, and improve the safety and reliability of the equipment. , It also improves the labor productivity and production safety of the operator.

In order to achieve the above-mentioned purpose, the present invention has adopted following technical scheme:

An intelligent exhaust system for the low-pressure end of the hydraulic system pump, including the pump, the low-pressure end of the pump is provided with a manual exhaust port, an air storage container set at a position higher than the pump and lower than the liquid storage tank, and the air storage container It is connected with the manual exhaust port, the gas storage container is provided with an exhaust port, and the exhaust port is connected with an exhaust valve, and the gas storage container is provided with a high and low liquid level sensor, and the gas storage container is provided with a high and low liquid level sensor. The liquid level sensor is connected with the control module, and the control module is connected with a monitoring indicating module and a fault indicating module.

As a preference, the above-mentioned high and low liquid level sensor includes a mounting rod vertically arranged in the gas storage container, the upper buoy and the lower buoy are placed on the mounting rod, and the upper and lower buoys are respectively limited to the upper and lower positions of the mounting rod. The limit structure for moving in two sections, wherein, the upper buoy and the lower buoy are provided with magnetic parts, and the installation rod is provided with an upper sensor and a lower sensor for respectively sensing whether the upper buoy and the lower buoy are in place, These two sensors are connected to the control module. The high and low liquid level sensor with this structure can effectively distinguish the air volume in the gas storage container; second, it can monitor the operating status of the system in real time, effectively identify sensor failures or other system failures, and give timely alarm prompts; third, The structure is simple and the manufacture is convenient.

Above-mentioned control module is carried out according to following steps:

Step 1, system initialization;

Step 2, read the state of the upper buoy and the lower buoy; when it is detected that the upper buoy and the lower buoy have reached the upper limit, the control module closes the exhaust valve; when it is detected that the upper buoy and the lower buoy have reached the lower limit, The control module opens the exhaust valve; when it detects that the upper buoy has reached the lower limit and the lower buoy has reached the upper limit, the control module opens the exhaust valve; when it detects that the upper buoy has reached the upper limit and the lower buoy has reached the lower limit, The control module closes the exhaust valve, and the fault indication module indicates that the sensor is faulty;

Step 3, read the state of the exhaust valve; when the control module instructs to open the exhaust valve and detects that the exhaust valve has been opened, the monitoring indicator module indicates that the exhaust is in progress; when the control module instructs to open the exhaust valve and detects that the exhaust valve When not open, the fault indication module indicates exhaust failure; when the control module instructs to close the exhaust valve and detects that the exhaust valve is closed, the monitoring indicator module indicates that monitoring is in progress; when the control module instructs to close the exhaust valve and detects exhaust When the valve is not closed, the fault indication module indicates the exhaust fault;

Step 4, return to step 2 to continue.

By adopting the above steps, the system can be automatically exhausted according to the air quality in the gas storage container, and has the function of self-monitoring and indication.

The above-mentioned monitoring indicating module and fault indicating module are sound and light indicating circuits.

The above-mentioned exhaust valve is a solenoid valve, and the exhaust valve is connected with a forced manual exhaust switch. The forced manual exhaust switch is set in consideration of the serious strong magnetic interference in the operating environment of the system, so that the exhaust valve can be manually opened to exhaust when the control circuit fails to open the exhaust valve.

To monitor the state of the above-mentioned exhaust valve, the control module can judge according to the detected change of the liquid level state, or an exhaust monitoring sensor can be independently installed on the above-mentioned exhaust valve, and the exhaust monitoring sensor can be connected to the control module.

The above-mentioned gas storage container is connected with the pump through a flexible pipe.

A liquid level observation window is provided on the side wall of the gas storage container.

Due to the adoption of the above technical scheme, the present invention can collect the air in the low-pressure circuit before the pump to the air storage container in a concentrated manner by utilizing the specific gravity of air being lighter than that of liquid. When the liquid level sensor senses that the liquid level is lower than the set height, the exhaust valve is opened. , using the high and low pressure difference in the liquid path to automatically exhaust the liquid, and the liquid level will rise automatically; after exhausting, the exhaust valve will close when the liquid level sensor senses that the liquid level reaches the set height. The device can automatically exhaust air according to the gas storage situation, avoiding manual and regular blind manual exhausting, greatly reducing the number of times workers come into contact with high-risk equipment and high-risk environments, which can greatly reduce the accident rate of major accidents, and improve the quality of equipment. The safety and reliability of the work are improved, and the labor productivity and production safety of the operators are improved.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Figure 2 is a program flow chart of the control module.

Fig. 3 is a block diagram of the electrical principle of the present invention.

Fig. 4 is a structural schematic diagram of the high and low liquid level sensor.

Detailed ways

The specific implementation manner of the present invention will be described in detail below in conjunction with the accompanying drawings.

Example 1:

As shown in Figure 1, an intelligent exhaust system for the low-pressure end of the hydraulic system pump, including a pump 1, the low-pressure end of the pump 1 is provided with a manual exhaust port 2, and also includes an The gas storage container 5 at the position of the liquid storage tank, the gas storage container 5 is connected with the manual exhaust port 2, the gas storage container 5 is provided with an exhaust port 6, and the exhaust port 6 is connected with an exhaust valve 7, so The gas storage container 5 is provided with a high and low liquid level sensor 8, as shown in Figure 3, the above-mentioned exhaust valve 7 and the high and low liquid level sensor 8 are connected to the control module 9, and the above-mentioned control module 9 is connected to a monitoring indication module and a fault indication module.

In this embodiment, the use of this system in a high-voltage power system is taken as an example. As shown in FIG. The buoy 82 and the lower buoy 83, and the installation rod 81 is provided with a limit structure that limits the movement of the upper buoy 82 and the lower buoy 83 in the upper and lower sections of the installation rod 81, wherein the upper buoy 82 and the lower buoy 83 are provided with magnetic parts, and the mounting rod 81 is provided with an upper sensor and a lower sensor for respectively sensing whether the upper buoy 82 and the lower buoy 83 are in place, and these two sensors are connected to the control module 9 . As shown in Figure 4, the upper buoy moves within A1-A2, and the lower buoy moves within B1-B2, where A1 and B1 are the upper limits of the upper and lower buoys respectively, and A2 and B2 are the upper and lower buoys respectively lower limit.

The above-mentioned monitoring indicating module and fault indicating module are both sound and light indicating circuits composed of LEDs and sounding devices. The above-mentioned exhaust valve 7 is a solenoid valve, which can be opened and closed directly by the control module 9, or can be opened and closed by the controlled module 9 through a certain exhaust control circuit or mechanism, and the above-mentioned exhaust valve 7 is connected with a forced manual exhaust valve. gas switch. The exhaust valve 7 is provided with an exhaust monitoring sensor connected to the control module 9 . The above-mentioned gas storage container 5 is connected with the pump 1 through the flexible pipe 3, so as to avoid the influence of the vibration of the pump. A liquid level observation window 4 is provided on the side wall of the gas storage container 5 .

As shown in Figure 2, the above-mentioned control module 9 is executed according to the following steps:

Step 1, system initialization;

Step 2, read in the state of the upper buoy 82 and the lower buoy 83; when it is detected that the upper buoy 82 and the lower buoy 83 have reached the upper limit (that is, there is no or only a small amount of air in the air storage container), the control module 9 closes the exhaust Air valve 7; when it is detected that both the upper buoy 82 and the lower buoy 83 have reached the lower limit (that is, the air storage container is full or there is a large amount of air), the control module 9 opens the exhaust valve 7; when it is detected that the upper buoy 82 has reached When the lower limit and the lower buoy 83 have reached the upper limit (that is, the liquid level is at the midline position, and there is more air in the gas storage container), the control module 9 opens the exhaust valve 7; When the buoy 83 has reached the lower limit, the control module 9 closes the exhaust valve 7, and the fault indication module indicates that the sensor is faulty;

Step 3, read the state of the exhaust valve 7; when the control module 9 instructs to open the exhaust valve 7 and detects that the exhaust valve 7 has been opened, the monitoring indicator module indicates that the exhaust is in progress; when the control module 9 instructs to open the exhaust valve 7 When detecting that the exhaust valve 7 is not opened, the fault indication module indicates an exhaust failure; when the control module 9 instructs to close the exhaust valve 7 and detects that the exhaust valve 7 has been closed, the monitoring indication module indicates monitoring; 9 Instruct to close the exhaust valve 7 and detect that the exhaust valve 7 is not closed, the fault indication module indicates an exhaust fault;

Step 4, return to step 2 to continue.

Claims (8)

1. An intelligent exhaust system for the low-pressure end of the hydraulic system pump, including a pump (1), the low-pressure end of the pump (1) is provided with a manual exhaust port (2), it is characterized in that it also includes a The gas storage container (5) at the position of the pump (1) and lower than the liquid storage tank, the gas storage container (5) is connected to the manual exhaust port (2), and the gas storage container (5) is provided with a vent The air port (6), the exhaust port (6) is connected with an exhaust valve (7), and the gas storage container (5) is provided with a high and low liquid level sensor (8), and the exhaust valve (7) and the high and low The liquid level sensor (8) is connected with the control module (9), and the control module (9) is connected with a monitoring indicating module and a fault indicating module. 2. An intelligent exhaust system for the low-pressure end of a hydraulic system pump according to claim 1, characterized in that the high and low liquid level sensor (8) includes a vertically arranged gas storage container (5) Mounting rod (81), upper buoy (82) and lower buoy (83) are put on the mounting rod (81), and the upper buoy (82) and lower buoy (83) are respectively limited in the installation rod (81). The limit structure for movement in the upper and lower sections of the rod (81), wherein the upper buoy (82) and the lower buoy (83) are provided with magnetic parts, and the installation rod (81) is provided with a separate sensor Measure the upper sensor and the lower sensor whether the upper buoy (82) and the lower buoy (83) are in place, and these two sensors are connected to the control module (9). 3. An intelligent exhaust system for the low-pressure end of a hydraulic system pump according to claim 2, wherein the control module (9) is executed according to the following steps: Step 1, system initialization; Step 2, read in the state of the upper buoy (82) and the lower buoy (83); when it is detected that the upper buoy (82) and the lower buoy (83) have reached the upper limit, the control module (9) closes the exhaust valve ( 7); When detecting that the upper buoy (82) and the lower buoy (83) have all reached the lower limit, the control module (9) opens the exhaust valve (7); when it is detected that the upper buoy (82) has reached the lower limit and When the lower buoy (83) has reached the upper limit, the control module (9) opens the exhaust valve (7); when it is detected that the upper buoy (82) has reached the upper limit and the lower buoy (83) has reached the lower limit, the control module (9) close the exhaust valve (7), and the fault indication module indicates that the sensor is faulty; Step 3, read in the state of the exhaust valve (7); when the control module (9) instructs to open the exhaust valve (7) and detects that the exhaust valve (7) has been opened, the monitoring indicator module indicates that the exhaust is in progress; when the control When the module (9) instructs to open the exhaust valve (7) and detects that the exhaust valve (7) is not opened, the fault indication module indicates an exhaust fault; when the control module (9) instructs to close the exhaust valve (7) and detects When the exhaust valve (7) is closed, the monitoring indicator module indicates that the monitoring is in progress; when the control module (9) instructs to close the exhaust valve (7) and detects that the exhaust valve (7) is not closed, the fault indication module indicates that the exhaust valve (7) is not closed. Fault; Step 4, return to step 2 to continue. 4. An intelligent exhaust system for the low-pressure end in front of a hydraulic system pump according to claim 1, 2 or 3, wherein the monitoring and indicating module and the fault indicating module are sound and light indicating circuits. 5. According to claim 1, 2 or 3, an intelligent exhaust system for the low-pressure end of a hydraulic system pump, wherein the exhaust valve (7) is a solenoid valve, and the exhaust valve ( 7) A forced manual exhaust switch is connected. 6. An intelligent exhaust system for the low-pressure end of a hydraulic system pump according to claim 1, 2 or 3, characterized in that, the exhaust valve (7) is provided with an exhaust monitoring sensor, and the exhaust Monitoring sensors are connected to the control module (9). 7. An intelligent exhaust system for the low-pressure end of the hydraulic system pump according to claim 1, 2 or 3, characterized in that the gas storage container (5) is connected to the pump (1) through a flexible pipe (3) )connect. 8. According to claim 1, 2 or 3, an intelligent exhaust system for the low-pressure end of the hydraulic system pump, characterized in that, the side wall of the gas storage container (5) is provided with a liquid level observation window ( 4).

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