RU2399083C1 - Pressure controller of indirect action - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: controller can be used for adjusting pressure of natural gas at output of gas-distributing stations. The pressure controller consists of cavities of gas input and output, of a cylinder case with an internal partition, of a control component in form of a movable piston valve pressed down to a seat with a return spring relative to the partition and coaxially positioned relative to the cavity of gas output, of a sensitive component in form of the piston travelling between the partition and a back cover of the case mutually positioned so as, successively with the valve, to form a relief cavity, and cavities of control and output pressure. Also the movable piston valve and piston are interconnected with a rod coaxial to the case. The rod and a fixed cylinder cartridge resting against the back cover of the case with its bottom form an additional relief cavity. The rod has through channels communicating main and additional relief cavities with the input cavity by means of a full pressure receiver containing a branch coaxial to the rod. The branch has bypass channels, area of cross section of which is at least twice as less, than cross section of the receiving channel.

EFFECT: diametre of case of controller is not limited by design, owing to which even small deviations of pressure in cavity of gas output are sufficient to change force on piston to make control valve move, to restore specified pressure, and to facilitate continuous equality of pressure in cavities divided with valve; also invention increases reliability of sealing on movable cone of valve and stability of control mode.

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Description

The present invention relates to the field of hydropneumatic automation and can be used to control the pressure of natural gas at the outlet of gas distribution stations.

Known pressure regulators of indirect action, in which the actuator is made in the form of a membrane actuator associated with a shut-off valve, which is the regulatory body. One of the best regulators of this type is the axial pressure regulator of indirect action, given in the book "Gas equipment, appliances and fittings". M., Nedra, 1985, the circuit diagram of which is shown in Fig. 2.11, p. 68. Its advantage is the fact that the shut-off valve, made in the form of a thin-walled pipe, is almost completely unloaded from the influence of the flow, and the rubber membrane is installed in a separate closed cavity that does not directly contact with the working gas; Nevertheless, in the process of operation, rubber loses its dynamic (and strength) characteristics, as a result of which its reliability and durability are reduced. In addition, all pressure regulators containing elastic sensitive elements in the form of a membrane have significant diametric dimensions and weight.

Closest to the technical nature of the present invention is an indirect gas regulator (see USSR author's certificate No. 126948, class G05D 16/10, 1983), containing inlet and outlet cavities, a cylindrical body with an internal partition, coaxially located relative to the cavity gas outlet, a regulating body in the form of a movable piston valve, pressed by a return spring relative to the partition, and a sensing element in the form of a piston moving between the partition and the rear housing cover, mutually memory location so that the subsequently formed for the discharge valve cavity, the cavity and the control pressure output, wherein the movable valve and the piston are interconnected coaxial with the rod body [prototype].

The disadvantage of this regulator is that its discharge cavity is in communication with the inlet cavity by means of a static pressure sensor, i.e. - minus the dynamic pressure, the value of which can be significant with increasing gas flow (load) through the regulator, which leads to the need to use a return spring of high stiffness. This reduces the accuracy of maintaining the outlet pressure and can even lead to self-oscillating and resonant valve movements. This circumstance forces the use, for example, of a hydraulic damping device, which significantly complicates the design of the regulator and reduces its reliability.

The aim of the invention is to increase reliability and durability, expand the scope of the regulator while maintaining sufficient accuracy of regulation.

This goal is achieved by the fact that the rod of the regulator, in combination with a fixed cylindrical cup, rested with a spherical bottom in the rear cover of the housing, forms an additional discharge cavity, and the rod is equipped with through channels communicating the main and additional discharge cavities with the inlet cavity of high pressure by means of a pipe coaxial with the rod made in the form of a receiver of full pressure, equipped with bypass channels, the cross-sectional area of which is at least half the cross-sectional area of the receiving channel.

The drawing shows a General view of the gas pressure regulator in the form of a longitudinal section with a remote element I.

The gas pressure regulator contains the cavity of the inlet (1) and the outlet (2) of gas, a cylindrical body (3) with an internal partition (4), coaxially located relative to the cavity of the outlet (2) of gas, a regulating body in the form of a movable piston valve (5), preloaded to the seat (6) with a return spring (7) relative to the partition (4), and a sensing element in the form of a piston (8) moving between the partition (4) and the back cover (9) of the housing (3), which are mutually arranged so that sequentially behind the valve (5) form a discharge cavity (10), the polo five control (11) and output (12) of pressure, the movable valve (5) and the piston (8) linked coaxially with the housing (3) rod (13). The rod (13) with a fixed cylindrical glass (14), supported by a spherical bottom in the back cover (9) of the housing (3), form an additional discharge cavity (15), and the rod (13) is provided with through channels (16), communicating the main (10) ) and additional (15) discharge cavities with an inlet cavity (1) of high pressure by means of a pipe (17) coaxial with the rod (13), made in the form of a full pressure receiver (element 1), equipped with bypass channels (18), the cross-sectional area of which at least half the cross-sectional area of the receiving channel (19).

The spring (7) pre-compressed during installation serves to move the valve (5) to the overlapping position of the annular gap formed by the seat (6) and valve (5) in the absence of gas in the pipeline and has low rigidity. The regulator operates as follows.

In the initial position, the regulator is closed. The indirect pressure regulator works in conjunction with a pilot device, usually consisting of a differential gear and an amplifier, which are supplied with input pressure energy. To open the regulator, the pressure reducer and amplifier are adjusted according to monometers to the specified pressures, while the control gas is supplied to the control pressure cavity (11) accordingly. The piston (8) moves and through the stem (13) moves the valve (5). The reduction of gas occurs due to its throttling as it passes through the annular gap between the valve (5) and the seat (6). After starting the regulator, the amplifier adjusts to the specified stationary mode of operation according to the output pressure, the value of which is set by the gas consumer. In the case of a decrease in gas consumption, the pressure in the outlet pipe increases, while the piston (8) moves to the left. The through-throttle cross section is reduced, which reduces gas consumption, restoring the required outlet pressure. When the output pressure decreases (gas consumption increases), the regulator operates in the reverse order.

Moreover, due to the fact that the design of the proposed controller uses an additional discharge cavity (15), which together with the main discharge cavity (10) is in communication with the gas inlet cavity (1) by means of a full pressure receiver, almost complete unloading of the valve (5) is ensured outside depending on the gas flow through the regulator. It is also significant that when using a polluted gas flow in the cavity of the full pressure receiver (17) through the bypass channels (18) connected to the inlet cavity (1), the gas that is substantially purified (due to inertial separation) enters the loading cavities of the regulator, which excludes wear of seals and violation of the regulation mode. In this case, the value of the outlet pressure set by the consumer, if necessary, can vary over a wide range by regulating the gas pressure in the control cavity (11), coordinated through the control pilot with the gas pressure entering the regulator cavity (12) from the outlet cavity (2), and the control limits are not depend on the stiffness of the spring, and are determined by the cross-sectional area of the annular gap between the valve (5) and the seat (6).

In the proposed regulator, the diameter of the housing (3) is not structurally limited, therefore, even with small pressure deviations in the gas outlet cavity, a change in the force on the piston (8) becomes sufficient to move the control valve (5) and restore the set pressure. In addition, the constant equality of pressure in the cavities separated by the valve (5) increases the reliability of the seals on the movable valve body (5) and the stability of the control mode.

Thus, the proposed design of the regulator provides sufficient accuracy, stability and wide limits of the gas pressure regulation process, which allows to increase safety, automate regulation processes, obtain gas savings and reduce labor costs at gas distribution stations, as well as improve the quality of technological processes at gas consuming enterprises .

Claims (1)

Indirect pressure regulator containing gas inlet and outlet cavities, a cylindrical body with an internal partition, coaxially located relative to the gas outlet cavity, a regulating body in the form of a movable piston valve, pressed against the partition by a return spring, and a sensing element in the form of a piston moving between the partition and the back cover of the housing, mutually arranged so that successively behind the valve form a discharge cavity, the cavity of the control and output one pressure, while the movable piston valve and the piston are interconnected by a rod coaxial with the housing, characterized in that the rod with a fixed cylindrical glass, rested with a spherical bottom in the rear housing cover, form an additional discharge cavity, and the rod is equipped with through channels communicating the main and additional unloading cavity with a gas inlet cavity through a full pressure receiver containing a pipe coaxial with the rod, equipped with bypass channels, the cross-sectional area of which is at least at least half the cross-sectional area of the receiving channel of the full pressure receiver.

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