SK129699A3 - Pressure regulating system - Google Patents

Abstract

A regulating system includes an underground pressure regulating module within a cartridge (112) which receives a high pressure gas stream and produces a low pressure output at a regulated pressure. The cartridge includes a main regulator valve (118) with associated pilot valves (120, 168). The pilot valve (168) has a variable set point which changes under instruction from control (153) so as to replicate demand patterns previously monitored.

Description

Pressure control system

Technical field

The invention relates to a pressure control system which uses an underground control module to control the pressure of a fluid (e.g. fuel gas) in a pipe.

BACKGROUND OF THE INVENTION

In known underground systems, the entire gas pressure control module 110 is arranged in an underground chamber (see FIG. 1) with all the main control devices contained in the module housing space, which module can be easily replaced for maintenance or other purposes.

Access to said module is via the inlet shaft cover 111. In practice, the buried piping systems typically comprise an inlet valve, an outlet valve, and a flap-type non-return valve located outside the module.

The gas pressure regulating module 110 is provided with a flange 113 (e.g., 150 mm diameter) for connection to the inlet conduit, and a flange 115 (e.g., 200 mm diameter) for connection to the outlet conduit.

The underground control module 110 includes a filter 116 through which gas passes into the chamber and then into the removable cartridge 112. The shut-off valve 117 is connected in series with the pressure control valve 118. A variety of additional components are provided, including several control valves. The replaceable cartridge 112 is pre-assembled so that it is readily replaceable to reduce downtime.

Such a control module can normally handle inlet pressures of up to four bar and outlet pressures set at between 20 and 75 millibars with a flow capacity of up to 8500 m ³ / h. The vent pipe 130 provides a comparative atmospheric pressure point for the replaceable cartridge 112 and accommodates additional conduit (shown schematically as conduit 131). The instrument box 133 includes a graphical recorder for inlet and outlet pressures and for various test test points (for example, for test of closure).

In order to increase the operational efficiency of the piping system, a clock-controlled starter can also be used to allow different pressure settings to be available when demand is low overnight.

Such an arrangement is shown in FIG. 2, wherein the shut-off valve 117 has been omitted for reasons of clarity.

The flow pressure is controlled by the main control valve 118, the adjustment of this valve 118 being performed by the control valve 120 (K1). The control regulator operates by receiving a pre-regulated gas supply through regulator 121 (J) before passing it through the constricted conduit 122 and then via control regulator 120 (K1) before it exits into the main conduit (not taking into account a possible control regulator 123 ( K2)).

The main control valve 118 receives gas into its control line near the outlet of the constricted pipe 122. Any pressure changes detected during operation by the control regulator 120 result in velocity changes in the constricted pipe 122 and cause a venturi effect which results in This causes the pressure to be applied against the spring regulating the diaphragm of the regulator 118 to change and bring the outlet pressure back to a predetermined value determined by the control regulator 120.

When the clock is applied, the auxiliary control controller 123 (K2) is provided with a different setpoint for operation with a differently set demand level than during the night. This requires the use of a clock mechanism 135 with an associated valve that is connected to the controller 123 via a fluid conduit.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a modified configuration with much more thorough control that will respond much more precisely to instantaneous requirements, with the device being largely built into an underground module.

In accordance with the present invention, a fluid pressure control system has been developed comprising a replaceable cartridge of an underground control module for insertion into an underground chamber in use, the auxiliary replaceable cartridge comprising a main pressure control valve and a shut-off safety valve connected in series with the controller; control means for providing a plurality of set parameters over a predetermined period for multiple usage requests and means within the module to respond to said parameters to effect changes in the operation of the main control valve within the module to achieve variable desired outlet pressure to meet the requirements for use.

Furthermore, in accordance with the present invention, a method for regulating pressure in a fluid control system comprising a replaceable underground control module cartridge equipped with a control valve and a shut-off valve has been developed, the method comprising monitoring fluid utilization over a given period through a recording device, parameters during a predetermined period based on the original usage information and control of the control valve in the filling space and control of the control valve in the filling space

Also by means of control means in order to vary the flow output in response to specified parameters to cause changes in the desired output pressure to meet the usage requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in more detail below by way of example of an embodiment thereof, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 illustrates an underground control module for controlling gas pressure;

Fig. 2 shows an outlet pressure control mechanism with a built-in clock mechanism;

Fig. 3 is a graph of utilization and output pressure requirements over time;

Fig. 4 shows a modified pressure control arrangement; and FIG. 5 shows the recording, measuring and control arrangements in more detail.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 3 shows pressure plots for gas supply. The requirement is to supply customers with a constant pressure gas stream of at least 20 millibars (see graph (a)). In practice, it is possible to reduce the respective outlet pressure of the regulator from 40 millibars to say 30 millibars during the night using the clock mechanism described above (see graph (b)) and still satisfy customer requirements.

The object of the invention allows the modified underground module to have a continuously variable adjustment

- 6 pressure depending on pre-identified use at relevant positions in the gas supply network. The utilization profile (see graph (c)) allows the available output (see graph (a)) to be maintained to meet the demand requirement while allowing lower pressure to be selected, thereby reducing volume requirements and the likelihood of leakage and so on.

Although the variations of graph (c) are shown to be relatively static over a given short period of time (e.g., one hour), in practice a large number of different variations and variations can be accommodated as desired.

In order to achieve the desired function, the replaceable module cartridge 112 is modified in the manner shown in FIG. 4th

The control valve 123 of FIG. 2 has been replaced by a double diaphragm valve 168 (KDP), which receives control from the write controller 153. Another control valve 120 (K1) can be maintained as required for safety reasons. The inlet control valve 157 provides a controlled supply of gas to the regulator for use therein. The needle valve 170 allows the adjustment of a restricted path that, in the event of a failure of the write regulator 153, will act as a safety path to provide a stable regulated outlet pressure at a predetermined level.

In operation, the writer controller 153 is programmed via information to allow pulse to diaphragm diaphragm valve 168 to impart a different setting to that valve depending on the pre-stored information to allow continuous adjustment of pressure changes to provide the graph (c) profile of FIG. Third

In practice, in order to cover the regulator, an additional instrument box, namely a control box 150 (see FIG. 5), is mounted on the vent pipe 130 under the already existing instrument housing 133. The process control line is fed via line 151 from the instrument box 133. The heart of the control arrangement is the write controller 153, which may include a microprocessor, memory, clock, and display.

Modem 154 allows to retrieve the written information remotely and sell information to the write controller 153 from a remote location. Depending on the operational and safety requirements, a low pressure shut-off and opening valve 156 and a supply pressure control valve 157 may be included.

The controller and recorder monitor pressure and utilization, thereby obtaining gas supply through a small tube at the inlet 160. They also utilize gas to operate the individual components that they acquire via the inlet pressure control valve 157. The outlet 161 passes to the instrument housing 133. The control output 163 provides control pressure for the underground regulator via a flexible conduit 164, which is a control conduit that is also connected to the low pressure shut-off and opening valve 156.

In the event of a failure, when the shut-off and opening valves 156 detect a low outlet, this will reduce the control pressure at the outlet and allow the outlet to increase the predetermined value of the underground controller. Pipe 165 provides a gas exit path during set-up changes.

The write controller 153 monitors and records usage and pressure information to determine the profile for a given station, which is unloaded once every 24 hours based on an immediate signal over a telephone line to modem 154. This information is used by a separate computer (not shown) to calculating the expected usage requirements and selecting the current setting at different pressures for use over the next 24 hours (with a reserve for handling at partially increased load), utilizing lightening via a telephone line leading to a controller that uses its internal clock to increase and depressurizing based on the preceding instructions throughout the day to effect variable pressure control for the replaceable cartridge 112 so as to achieve, for example, the results shown in graph (c) of FIG. and FIG. Third

The recording device may also emit alarms and other signals that are sent to a remote station via a modem. Although it is possible to use telephone lines, it is also possible to use radio or other transmission techniques.

The cartridge is easily interchangeable with the cartridge of FIG. 1 and does not require any excavation work since it is inserted into an existing chamber and is closed using the same partition or shutter.

Claims (15)

PATENT CLAIMS A fluid pressure control system comprising a replaceable cartridge of an underground control module for insertion into an underground chamber in use, the auxiliary replaceable cartridge comprising a main pressure control valve, and a shut-off safety valve connected in series with the controller, and control means for providing a plurality of set parameters over a predetermined period for multiple usage requirements and means within the module to respond to said parameters to effect changes in the operation of the main control valve within the module to achieve variable desired outlet pressure to meet the usage requirements . System according to claim 1, characterized in that the means for causing changes in the operation of the main control valve comprises a dual membrane mechanism, which performs differential control. System according to claim 2, characterized in that the means are located on the module but separate from the main control valve. I System according to claim 1, 2 or 3, characterized in that the recording means are arranged to monitor the use of the fluid over a given period in order to determine the requirements for future use. System according to claim 4, characterized in that remote access means are provided 10 for obtaining the written information, means for computer processing the set parameters, and means for conveying information about these parameters to enable remote control system control. System according to claim 4 or 5, characterized in that the recording means are arranged on a vent pipe above the ground surface. System according to any one of the preceding claims, characterized in that the regulated pressure source is arranged for the control means, wherein the shut-off and opening valve is arranged to open in the event of a failure. System according to any one of the preceding claims, characterized in that it comprises needle valve means for providing a stable comparative adjustment in the event of a failure of the control means. 9. A method of regulating a pressure in a fluid control system comprising a replaceable charge to an underground control module, equipped with a control valve and a shut-off valve, comprising monitoring the fluid utilization over a given period by means of a recording device, providing a plurality of set parameters during pre-set a period of time based on original usage information and regulating the control valve in the charge space by the control means to change the flow output in response to the set parameters to cause changes in the desired outlet pressure to meet the usage requirements. 10. The method of claim 9, comprising remote access to the written information, computer processing of the set parameters, and transmitting the set parameters back to the control system to enable control. The method of claim 9 or 10, comprising controlling the double diaphragm control valve to modulate the control valve setting. Method according to claim 9, 10 or 11, characterized in that it comprises opening the shut-off and opening valve in the event of a failure to allow the pressure to be increased to a predetermined value. Method according to any one of claims 9 to 12, characterized in that it comprises the provision of a needle valve in order to facilitate a stable comparison in the event of a failure of the control means. The fluid pressure control system substantially described herein with reference to FIG. 3 to FIG. 5 of the attached drawings. 15. A method of regulating the fluid pressure of a control system as described in the embodiment herein.