RU2616220C1 - Gas pressure controller - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: controller includes inlet (5) and outlet (13) gas channels, a body (1) with its back cover (22), inside of which a piston valve (3) cooperating with the saddle (2) connecting the inlet (5) and outlet (13) gas channels, and a control piston (30) sealingly separated from each other by the fixed sleeve (32) forming, respectively, a discharge cavity (16) and a control pressure cavity (18), are fixed on the rod (25) with the possibility of the axial movement. The saddle (2) is provided with a cap nut (6) forming a cavity between them, inside of which a removable deformable seal (35) is installed, latched with the cap nut (6), and a profiled ring (14) is hermetically installed on the piston valve (3), the projection of which enters the cavity between the saddle (2) and the cap nut (6) and forms a throttle passage with a variable area of the flow cross-section, when moving the piston valve (3). The saddle (2), the seal (35), the cap nut (6) and the profiled ring (14) define the throttle channel geometry at the "open" regulator and ensure tightness at the "closed" pressure regulator. A significant pressure drop is produced when throttling gas between the inlet channel (5) and outlet channel (13), fluctuations are generated in the stream caused by loose phenomena and self-fluctuations, wherein good streamlined surfaces and special profiling of the throttle passage can reduce the noise level generated in the controller.

EFFECT: increasing the regulator reliability and the resource of its operation.

8 cl, 4 dwg

Description

The invention relates to mechanical engineering, namely to pneumatic automation, and can be used to reduce and control the pressure of the gas entering the consumer from the high-pressure line, for example, to control the pressure of natural gas at the outlet of gas distribution stations.

Indirect pressure regulators are known in which a shut-off valve controlled by a rubber membrane is used as an actuator (Gas equipment, devices and fittings - M .: Nedra, 1985, p. 68). The advantage of such devices is that the actuator can be unloaded from the effects of flow and to exclude direct contact of the working medium with a rubber membrane. However, during operation due to mechanical and thermal effects, the rubber membrane loses its strength and dynamic characteristics, which reduces the sensitivity of the actuator, reliability and durability of the device.

Known pressure regulator (AS USSR No. 1171761, MKI G05D 16/10, publ. 08/07/1985, bull. No. 29) containing a housing with inlet and outlet cavities, between which there is a regulatory body associated with a sensitive element equipped with a control mechanism and a spring-loaded rod connected to the equalizing piston installed in the bore of the housing and forming a cavity with it, connected to the hydraulic damping device through the pressure relief element of the regulating body according to the input pressure. The regulator is additionally equipped with an annular piston installed in the housing bore coaxially with the equalizing piston.

The closest in technical essence and adopted for the prototype is a gas pressure regulator (RF patent No. 2361261, IPC G05D 16/10, publ. 07/10/2009, bull. No. 19), containing gas inlet and outlet channels, a housing with a back cover, inside which on a rod mounted with axial movement, a piston valve is fixed, which communicates the gas inlet and outlet channels, and a control piston, which are separated from each other with the formation of a discharge cavity and a control pressure cavity, respectively, and between the control piston and the rear housing cover an outlet pressure cavity is formed, the discharge cavity being in communication with a gas inlet channel, an outlet pressure cavity in communication with a gas outlet channel. The inlet channel is in communication with the outlet channel through a piston valve cooperating with a seat located in the inlet channel. The control pressure cavity is in communication with the gas command pressure system by means of a damping system, which includes a separation tank with gas and hydraulic cavities and a jet, the gas cavity communicating with the gas command pressure system and the hydraulic cavity through the nozzle with the control pressure cavity. In the separation vessel, the gas and hydraulic cavities are separated by means of a bellows, or a membrane box, or a flaccid membrane. The device has insufficient accuracy of maintaining the outlet pressure at low gas flow rates and low resource due to valve wear and seat seal. In addition, with a quick change of operating parameters, with a sudden start, a sharp increase in pressure, a sharp change in gas flow at low flow rates, self-oscillations occur in the regulator, which lead to wear of the saddle-valve pair, since the regulator contains an elastic element (spring), which contributes to oscillatory movements of the valve relative to the seat, which leads to pressure pulsations in the outlet cavity (consumer pressure). Thus, at low flow rates in such systems, self-oscillation of the valve develops, which significantly reduces the reliability and accuracy of maintaining the outlet pressure.

The technical result, the achievement of which the present invention is directed, is to increase the resource of the regulator and increase the reliability of operation and the accuracy of maintaining the outlet pressure at low gas flow rates, reducing noise.

The technical result is achieved by the fact that in the gas pressure regulator containing the gas inlet and outlet channels, a body with a back cover, inside of which a piston valve communicating the gas inlet and outlet channels and the control piston are separated are mounted on a rod mounted with axial movement with each other with the formation, respectively, of the discharge cavity and the cavity of the control pressure, and between the control piston and the back cover of the housing, an outlet pressure cavity is formed, while the discharge cavity communicates on with the gas inlet channel, the outlet pressure cavity is in communication with the gas outlet channel, the control pressure cavity is in communication with the gas command pressure system, the inlet channel is communicated with the outlet channel by means of a piston valve interacting with a seat located in the inlet channel, new is that the saddle equipped with a union nut with the formation of a cavity between them, inside of which a removable seal is installed, fixed by a union nut, and on the piston valve on the inlet side a removable profiled is hermetically installed a ring whose profile enters the cavity between the seat and the union nut and forms a throttle channel with a variable passage area when moving the piston valve.

The removable seal between the seat and the union nut is deformable.

The throttle channel formed by the seat, union nut and profiled ring has well streamlined surfaces.

The throttle channel formed by a saddle, a union nut and a profiled ring has a cylindrical part in the initial section, turning into an expanding part.

The throttle channel formed by a seat, a union nut and a profiled ring is formed by combined stepwise variable conical surfaces with different angles at the top of the cones: the initial section with a small taper angle and the conjugate section with a large taper angle.

The union nut on the piston valve side has a well streamlined surface.

There is a seal on the outer surface of the seat on the side of its contact with the regulator body, and there is also a seal between the piston valve and the profiled ring.

In FIG. 1 is a longitudinal section through a pressure regulator.

In FIG. 2 shows a longitudinal section of a throttle assembly with smooth generators of the surfaces of the throttle channel.

In FIG. 3 shows a longitudinal section through a throttle assembly with stepwise variable conical surfaces of the throttle channel.

In FIG. 4 is a longitudinal section through a throttle assembly with a cylindrical portion of the throttle channel at its initial portion.

Here: 1 - housing; 2 - a saddle; 3 - piston valve; 4 - holes for the selection of static pressure; 5 - gas inlet channel; 6 - a union nut; 7- seal between the inner surface of the seat 2 and the union nut 6; 8 - a stub; 9 - jet; 10 - command pressure fitting; 11 - filter; 12 - a sealing ring on the outer surface of the seat 2 from the side of its contact with the housing 1; 13 - gas outlet channel; 14 - shaped ring; 15 - a piston; 16 - discharge cavity; 17 - channel transmission control pressure; 18 - cavity command pressure; 19 - cuff; 20 - feedback pressure cavity; 21 - stem cuff; 22 - a cover; 23 - a glass; 24 - cavity compensation input pressure; 25 - stock; 26 - through axial channel; 27 - a lock ring; 28 - a lining; 29 - channel for transmitting feedback pressure; 30 - control piston; 31 - spring; 32 - fixed sleeve; 33 - piston seal 15; 34 - a sealing ring between the piston valve 3 and the profiled ring 14; 35 - removable deformable seal in the cavity between the seat 2 and the union nut 6; 36 - feedback pressure fitting; 37 - feedback pressure line; 38 - line command pressure; 39 - the surface of the throttle channel formed by the seat 2; 40 - the outer surface of the profiled ring 14; 41 - the inner surface of the shaped ring 14; 42 - the surface of the throttle channel formed by a union nut 6.

The pressure regulator includes channels for the inlet 5 and gas outlet 13, a housing 1 with a cover 22, inside of which a piston 15 and a piston valve 3 with a profiled ring 14 are fixed to the piston valve 25, which communicates the gas inlet 5 and the gas outlet 13, when interacting with the seat 2 and the control piston 30 with the formation of the discharge cavity 16 and the cavity of the command pressure 18, respectively, hermetically separated by a fixed sleeve 32. The seat 2 is provided with a union nut 6 with the formation of the floor between them STI, inside which is installed a deformable seal 35, lockable cap nut 6 and the piston valve 3 with the inlet side sealed profiled ring set 14 with the projection of the periphery. The protrusion of the profiled ring 14 enters the cavity between the seat 2 and the union nut 6 and forms a throttle channel with a variable bore when moving the piston valve 3. The surface 39 of the seat 2, the surface of the deformable seal 35, the surface 41 of the union nut 6, the surfaces 40 and 41 of the profiled rings 14 (Fig. 2) determine the geometry of the throttle channel through which gas is supplied (throttled) from the input channel 5 to the output channel 13 with an “open” regulator. The spring 31, relying on the stationary sleeve 32, compresses the piston 15 and the piston valve 3 together with the profiled ring 14 to an easily removable deformable seal 35, which ensures the tightness of the pressure regulator in the "closed" position. A sealing ring 12 is installed on the outer surface of the seat 2 from the side of its contact with the regulator body 1, which ensures the tightness of the connection and separates the gas inlet channel 5 from the outlet channel 13. A seal 7 is installed between the inner surface of the seat 2 and the union nut 6. Between the control piston 30 a feedback pressure cavity 20 is formed and a cover 22 in the housing 1. A command pressure cavity 18 is formed between the control piston 30 and the stationary sleeve 32 in the housing 1. A pressure cavity 18 is formed between the piston 15 and the stationary sleeve 32 a discharge cavity 16 is connected to the unit, in communication with the gas inlet channel 5. The command pressure cavity 18 is in communication with the command pressure line 38 via the channel 17 and the nozzle 10. The feedback pressure chamber 20 is connected to the feedback pressure line 37 through the channel 29 and the nozzle 36. B the tail portion of the rod 25 is formed by a cavity for compensating the inlet pressure 24, which is in communication with the gas inlet channel 5 by means of a through axial channel 26 in the rod 25 connected to the static pressure selection hole 4.

The pressure regulator works in conjunction with the command gas pressure system, which can be used as a pressure regulator (pilot regulator), gearbox and other similar devices. In these devices, regulated gas is most often used as a working fluid.

To open the regulator, the gas command pressure system is adjusted to a certain predetermined pressure, which is transmitted through the nozzle pressure line 38 through the nozzle 11 to the command pressure cavity 18. Under the influence of command pressure, the control piston 30 moves and through the piston valve 3 rigidly connected to the rod 25 opens the pressure regulator . Gas reduction occurs when it passes through a throttle channel formed by the surface 42 of the union nut 6, the surface of the deformable seal 35, the surfaces 40 and 41 of the shaped ring 14, the surface 39 of the seat 2 (Fig. 2, 3, 4). In the process, an additional correction of the control pressure is possible to select one or another mode of operation of the regulator for the output pressure, the value of which is set by the gas consumer. With an increase in the flow rate of the consumed gas, the pressure in the gas outlet channel 13 decreases and is transmitted along the feedback pressure line 37 through the channel 29 to the cavity 20. The decrease in pressure in the cavity 20 leads to an imbalance of the control piston 30 and its movement, and with it the displacement of the piston valve 3, as a result of which the passage area of the throttle channel increases, and consequently, the gas flow rate. The control piston 30 moves with the piston valve 3 until an equilibrium is established corresponding to a given output pressure at a new flow rate. With a decrease in the flow rate of the consumed gas, the pressure in the gas outlet channel 13 rises, which leads to a reverse movement of the control piston 30 and a decrease in the area of the throttle channel. In order to reduce the pressure fluctuations arising in the gas outlet channel 13 and to ensure the stable operation of the pressure regulator, a feedback pressure line 37 is provided, which communicates the feedback pressure cavity 20 with the consumer line in a section located at a distance of at least six pipeline diameters after the pressure regulator.

To ensure stable operation of the regulator at low gas flow rates, to prevent sticking of the profiled ring 14 and to reduce self-oscillations, the geometry of the throttle channel is set in such a way that at low flow rates and, therefore, small passage sections of the throttle channel, the movement of the piston valve 3 does not lead to a significant change in throttle channel section.

This is achieved by profiling surfaces 39, 40, 41, 42. In FIG. 2 is a longitudinal section through a smooth-running throttle channel where tangents to surfaces 39 and 42 at their contact with the removable deformable seal 35 form an angle close to 90 ° with respect to the surface of the deformable seal 35. Rounding radii R at surfaces 40 and 41 the shaped ring 14 is R≤0.5 L, where L is the thickness of the shaped ring 14.

In FIG. 3 shows a longitudinal section of a throttle assembly with stepwise variable conical surfaces of the throttle channel. The surfaces of the throttle channel 42 formed by a union nut and 39 formed by a saddle are combined in the form of stepwise variable conical surfaces with different angles at the apex of the cones: the initial section with a small angle of taper and the conjugate section with a large angle of taper.

In FIG. 4 is a longitudinal section through a throttle assembly in which the throttle channel formed by the surface 39 of the seat 2 and the surface 42 of the union nut 6 and the profiled ring 14 has an initial cylindrical portion that passes into the expandable part.

When gas is throttled due to high flow rates and the possible presence of various abrasive particles in the gas, erosion of the elements of the throttle channel occurs.

The elements of the throttle channel union nut 6, seat 2, shaped ring 14 are made of wear-resistant material and allow their dismantling and replacement, which increases the resource of the regulator and the reliability of its operation. The deformable seal 35 is easily removed and replaced, which also contributes to an increase in the resource of the regulator and its reliability. In addition, the change of the profiled ring 14, and / or union nut, 6 and / or seat 2 makes it easy to change the operating characteristics of the regulator, to increase or decrease the range of regulation of flow, pressure and provides maintainability.

A slight change in the area of the throttle channel occurring at a small distance of the piston valve 3 from the surface of the deformable seal 35 (from several fractions of mm to 1-2 mm) ensures stable operation of the regulator at low flow rates and reduces self-oscillations in the gas flow control system and prevents sticking shaped ring 14.

The geometry of the throttle channel is ensured by the fact that:

- the throttle channel formed by the seat 2, the union nut 6 and the profiled ring 14, has well streamlined surfaces;

- the throttle channel has in the initial section a cylindrical part, passing into an expanding part;

- the throttle channel is formed by combined stepwise variable conical surfaces with different angles at the top of the cones: the initial section with a small angle of taper and the conjugate section with a large angle of taper;

- the union nut 6 from the side of the piston valve 3 has a well streamlined surface.

During gas throttling, a significant pressure difference is formed between the input channel 5 and output channel 13 (including the supercritical pressure difference) in the flow, oscillations are generated due to separation phenomena and self-oscillations, while well-streamlined surfaces and special profiling of the throttle channel can reduce the noise level, generated in the regulator

Claims (8)

1. Gas pressure regulator containing gas inlet and outlet channels, a housing with a back cover, inside of which a piston valve communicating gas inlet and outlet channels, and a control piston are separated with each other, forming respectively the discharge cavity and the control pressure cavity, and an outlet pressure cavity is formed between the control piston and the back cover of the housing, while the discharge cavity is in communication with the gas inlet channel, the outlet cavity for the phenomena are in communication with the gas outlet channel, the control pressure cavity is in communication with the command gas pressure system, the inlet channel is in communication with the outlet channel by means of a piston valve interacting with a seat located in the inlet channel, characterized in that the seat is provided with a union nut to form a cavity between them, inside of which a removable seal is installed, fixed by a union nut, and on the piston valve on the inlet side a removable profiled ring with a protrusion on the periphery, a protrusion of which first enters the cavity between the seat and cap nut and forms a throttling passage with variable cross section flow area by moving the piston valve. 2. The gas pressure regulator according to claim 1, characterized in that the removable seal between the seat and the union nut is deformable. 3. The gas pressure regulator according to claim 1, characterized in that the throttle channel formed by a seat, a union nut and a profiled ring has well streamlined surfaces. 4. The gas pressure regulator according to claim 1, characterized in that the throttle channel formed by a seat, a union nut and a profiled ring has a cylindrical part in the initial section, turning into an expanding part. 5. The gas pressure regulator according to claim 1, characterized in that the throttle channel formed by a seat, a union nut and a profiled ring is formed by combined stepwise variable conical surfaces with different angles at the top of the cones: the initial section with a small angle of taper and the conjugate section with a large angle of taper. 6. The gas pressure regulator according to claim 1, characterized in that the union nut on the piston valve side has a well streamlined surface. 7. The gas pressure regulator according to claim 1, characterized in that on the outer surface of the seat on the side of its contact with the regulator body there is a seal. 8. The gas pressure regulator according to claim 1, characterized in that there is a seal between the piston valve and the profiled ring.

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