RU170004U1 - Electrohydrodrive with backup autonomous pneumatic system - Google Patents

Abstract

The electrohydraulic actuator EGPP, with a backup autonomous pneumatic system, is intended for use as a drive device for mechanizing shut-off valves of pipelines. The claimed electrohydraulic actuator with a backup autonomous pneumatic system (EGPP) consists of the following units: a rocker mechanism located in the housing, and two opposed cylinders attached to it , - one hydraulic cylinder and one pneumatic cylinder, the rods of which are connected to the wings, while the rocker mechanism provides linear displacement of the cylinder rods at the moment of rotation transmitted to the shutoff valve shaft, and the working media of the cylinders are separated from each other to ensure independent use of the cylinders. The technical result is to ensure high reliability, efficiency and reliability of control of pipeline valves.

Description

EGPP electrohydrodrive, with a backup autonomous pneumatic system, is intended for use as a drive device for mechanization of pipeline shutoff valves.

From the document RU 130366 U1, a device for remote automatic monitoring and control of stop valves of a pipeline is known. The electrohydraulic actuator is made with a spring-hydraulic mechanism, comprising a housing equipped with a cavity divided into two parts by a piston installed in it, equipped with a rod connected to the working body of the shutoff valves. A part of the cavity contains an energy storage device in the form of a spring in contact with the piston, and a part of the cavity is connected with the working fluid tank via a line containing an electric pump, a pressure sensor of the working fluid, an electromagnetic valve, and a filter, a non-return valve, and a manual valve valve. The line is equipped with a mechanical pilot valve and a fusible link connected to the pipeline. Shut-off valves contain a position sensor of the working body connected to the controller.

A redundant electro-hydraulic actuator is known from RU 2190129 C2, which contains a two-chamber hydraulic cylinder and two electro-hydraulic control channels interconnected by hydraulic lines, each of which is equipped with a seven-line valve with a spool valve, while the feed line through the ring valve is connected to the right middle collar and simultaneously through permanent throttles to its under-end control chambers and nozzles, and drain lines to the right extreme shoulder and left middle shoulder, lanes and the cylinder chambers are connected respectively to the right extreme and middle grooves, the left middle and left extreme collars and are interconnected through windows formed by negative overlays along the collars, and the left extreme groove, and the magnitude of each of the negative overlaps is 1.5-2 times the given value of the possible difference of the signals at the control inputs of each of the electro-hydraulic channels.

A known design of an electrohydrodrive, where for the ability to work autonomously in case of power outages in the power network, accumulators are used, which allow up to three permutations of the valve shutter due to the pressure energy of the fluid accumulated in them. An inert gas is used as a buffer medium for the battery. The disadvantage of this design is that the control medium enters the actuator hydraulic cylinder not directly from the discharge channel of the hydraulic station, but through the accumulator, which must always be charged for the maximum number of permutations in an autonomous mode. Based on this, the pressure in the accumulator is 3-4 times higher than the pressure required for the development of the force by the hydraulic cylinder of the drive when the shut-off valves are repositioned. The accumulator charging time is significantly longer than the time of rebuilding the valves, which leads to a reduction in the life of the hydraulic station. The disadvantage of this design is that when the buffer medium is lost or the electric pump unit fails, the drive becomes inoperative, since it is impossible to maintain the necessary pressure in the accumulator.

The claimed design of the EGPP is devoid of the above disadvantages, and it is also easier to manufacture and has smaller overall mass characteristics.

Due to the reduction in the amount of hydraulic fluid used in the hydraulic system and the use of a less powerful electric motor of the hydraulic unit, as well as the absence of a large number of vessels operating under high pressure, the duplicating pneumatic system due to its autonomy can be used to control shut-off valves even with prolonged failure of the drive electro-hydraulic system without affecting efficiency and safety of the operation of the pipeline.

Thus, the technical result is to ensure high reliability, efficiency and reliability by controlling pipe valves.

The scheme of the electrohydraulic drive with a backup pneumatic system EGPP is shown in the drawing, where:

1 - Cylinder with compressed air;

2 - Check valve;

3 - Pressure sensor;

4 - Pressure reduction gear;

5 - valve;

6 - Drying chamber;

7 - Hydraulic station with an external power source;

8 - Explosion-proof distribution valve;

9 - Hydropneumatic drive;

10 - Block of limit switches;

11 - Control and automation unit with an independent power source (AB).

гидравлическая схема подключения

hydraulic connection diagram

электрическая схема подключения

wiring diagram

An electrohydraulic actuator with a backup autonomous EGPP pneumatic system consists of the following units: a rocker mechanism located in the housing, and two opposed cylinders attached to it - one hydraulic cylinder and one pneumatic cylinder, the rods of which are connected to the wings. The rocker mechanism provides the conversion of the linear movement of the cylinder rods at the moment of rotation, transmitted to the shaft of the stop valve. The working media of the cylinders is separated from each other, so the cylinders can be used independently. The main working cylinder is hydraulic, its work is provided by a hydroelectric station, and control is carried out by an electro-hydraulic control system. In case of violation of external power supply, failure of the pump or email. the engine of the hydraulic power station and other reasons, the shutoff valves are rearranged by the pneumatic cylinder of the backup pneumatic system, consisting of a control unit with an autonomous power supply and a compressed gas source. Thereby, high reliability, efficiency and reliability of control of pipeline valves is achieved.

When the installation is operating in normal mode, when a signal is sent to relocate the shutoff valves, the hydro-electric motor and the working fluid are launched through the channels of the hydraulic distributor, depending on the chosen direction “open” / “close”. The working fluid enters the working cavity of the hydraulic cylinder, moves the rod and the associated wings and the rod of the pneumatic cylinder. The cavity of the pneumatic cylinder at this moment is connected to the atmosphere. When the end position is reached, the contacts of the limit switch are closed / opened, the power circuit and the control circuit of the hydraulic power station are de-energized. The cycle is completed.

If the pump fails, the engine of the hydraulic power station, in the absence of external power supply or other emergency situations, the rearrangement of shutoff valves is carried out by a backup autonomous pneumatic control system. The backup autonomous pneumatic control system includes: a source of compressed air, a three-stage reducing circuit, a filter dryer, connecting lines, pneumatic valves, a telemetry unit with sensors, and a power source (AB).

When the pneumatic control system (PSU) is activated, a control signal is sent to one of the “open” / “close” pneumatic control valves, compressed air with constant pressure enters the pneumatic cylinder, moving the rod and the wings connected to it and the rod of the hydraulic cylinder. In this case, the hydraulic cylinder cavities are connected by a bypass line. Integrated sensors in the control system monitor the pressure in the working line and the cylinder, giving a signal to replace the cylinder when the threshold is reached.

Claims (1)

An electrohydraulic actuator with a backup autonomous pneumatic system (EGPP), characterized in that it consists of the following nodes: a rocker mechanism located in the body, and two opposed cylinders attached to it - one hydraulic cylinder and one pneumatic cylinder, the rods of which are connected to the wings, the rocker mechanism provides the conversion of the linear movement of the cylinder rods at the moment of rotation transmitted to the shutoff valve shaft, and the working media of the cylinders are separated from each other to ensure independent use of cylinders.

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