RU2761939C1 - Gas distribution unit - Google Patents

Abstract

FIELD: testing.

SUBSTANCE: invention relates to apparatuses for gas pressure control without auxiliary power sources and can be used in designing and operating gas networks. The substance of the invention consists in preventing the overcooling of the elements of the equipment of the gas distribution unit (GDU). The pressure adjusters, which are one of the main elements of the GDU, can be subjected to freezing due to the occurrence of hydrates at the pressure reduction point. Ice may accumulate in the adjuster, thereby interfering with the operation of the adjuster. In order to prevent overcooling of the elements of the GDU, a Ranque-Hilsch vortex tube is used, installed before the pressure adjuster with a safety shutoff valve in the direction of the high-pressure gas flow. The heated gas from the Ranque-Hilsch vortex tube enters the pressure adjuster with a safety shutoff valve. The gas temperature is reduced due to the reduction in pressure. The GDU fittings are therein not overcooled and hydrates are not formed. The gas then enters a low-pressure gas pipeline. The cooled gas from the Ranque-Hilsch vortex tube is suctioned by an ejector installed on the high-pressure gas pipeline. The high-pressure gas of the initial temperature is therein mixed with the cooled gas. The total temperature of the gas in the high-pressure pipeline is reduced. In order compensate for heat losses, the gas pipeline and the cooled high-pressure gas pipeline are laid below the freezing depth of the ground.

EFFECT: ensured restoration of the temperature in the high-pressure gas pipeline to the next gas distribution unit.

2 cl, 1 dwg

Description

The invention relates to the field of gas supply, in particular to devices for regulating the pressure of gases without auxiliary energy sources, and can be used in the design and operation of gas networks of medium and low pressure. The essence of the invention lies in the prevention of overcooling of the elements of the equipment of the gas control point (HSC).

Hydrates, or a frozen mixture of water and hydrocarbons, are formed when, for example, water and natural gas come into contact with a material at low temperatures. Freezing caused by hydrates can result from the passage of a hydrocarbon fluid containing water vapor and / or carbon dioxide through the pressure regulator. As the pressure of the fluid decreases, in accordance with the operation of the pressure regulator, the temperature of the fluid also decreases according to the Joule-Thomson effect. As a result of the temperature drop, any moisture present in the fluid stream can cause hydrates to form. A decrease in pressure is accompanied by overcooling of the pressure regulator elements. Pressure regulators, which are one of the main elements of hydraulic fracturing, can freeze and hydrate at the point of pressure reduction. Hydrate buildup in the pressure regulator can prevent the pressure regulator valve from opening and closing properly, affecting its ability to control gas pressure.

Known device "Vortex gas pressure regulator" [RU 2655565 C2 IPC G05D 16/04, publ. 28.05.2018 Bul. No. 15], containing a housing with inlet and outlet nozzles, a vortex chamber coaxially installed with the outlet nozzles, an energy separation chamber equipped with ribbing on the outer side, a swirling device, characterized in that a regulator made in the form of a regulating wedge equipped with an electric drive, while the energy separation chamber is coaxially connected to the heated flow outlet pipe, equipped with a regulating cone located inside it, made with the possibility of reciprocating movement along the pipe axis, in addition, the vortex chamber is located inside a cylindrical jacket, the cavity of which is communicated with the outlet of the cooled flow and the outlet of the heated flow, and the vortex chamber housing is equipped with an annular heating channel of the diaphragm connected by a tube with the outlet of the heated flow, while the outlet of the heating channel is located placed in the cooled flow chamber.

The disadvantage of this device is the presence of a regulator equipped with an electric drive, which increases the explosion and flammability of the structure, and also requires supplying power lines to the hydraulic fracturing station.

Known invention "Regulators of fluid pressure with heating" [RU 2672835 C2 IPC G05D 16/06, publ. 19.11.2018 Bul. No. 22]. The device consists of a regulator containing a body, a stem located therein, a first inlet and a first outlet. The regulator controls the pressure of the fluid flowing from the first inlet to the first outlet. The device contains a turbulator located inside the housing, made with the possibility of transferring heat to the regulator valve. The stem controls the regulator and the turbulator. As a result, ice does not accumulate in the regulator and does not interfere with its operation.

The disadvantage of the device is the complexity of manufacturing the pressure regulator housing, which has an additional outer jacket, which is a turbulizer.

The closest in technical essence to the claimed device, the prototype is "Gas control point" [RU 2253145 C2 IPC G05D 16/04, publ. 05/27/2005 Bul. No. 15], containing a high-pressure gas pipeline with a thermometer showing and recording pressure gauges, a gas purification filter from mechanical impurities with a liquid pressure gauge, a gas flow unit, a safety shut-off valve, an outlet pressure gas pipeline with indicating and recording pressure gauges, a relief device, a bypass gas pipeline, a vortex tube enclosed in a thermostatic housing necessary for mixing hot and cold gas flows from the vortex tube, a safety shut-off valve is connected to the inlet of the vortex tube, and the thermostatic body is connected to the outlet (low) pressure gas pipeline.

The disadvantage of this device is the absence of a pressure regulator in the circuit, and, as a consequence, the weak ability to maintain a stable pressure with a varying gas flow rate at the outlet of the hydraulic fracturing. The disadvantages also include the presence of a sealed thermostatic housing, inside which a vortex tube is located. This housing must maintain tightness against a constantly changing internal pressure, which is always higher than atmospheric. This complicates the design of the gas control station and reduces its operational reliability at a continuously changing pressure.

The objective of the invention is to develop a method to prevent overcooling of the equipment elements of the gas control point. The technical result is to ensure efficient and reliable operation of the gas control point.

High pressure gas pipelines are designed to transport gas over long distances. In the overwhelming majority of cases, high-pressure gas pipelines are laid underground. In exceptional cases, above-ground laying of gas pipelines is allowed [SP42-01-2002 "Gas distribution systems" clause 5.1.2].

The problem is solved by the fact that in the method of operation of the gas control point, which includes the supply of high-pressure gas through a gas pipeline located below the earth's surface, measuring the gas pressure at the inlet with a pressure gauge, sequential passage of gas through shut-off valves, a filter, a gas meter with the flow of gas into the Ranque vortex tube -Hilsch, the flow of hot gas from the Rank-Hilsch vortex tube to the pressure regulator with a built-in safety shut-off valve for stable pressure maintenance in the downstream low pressure gas pipeline with varying gas flow rate, the cooled gas is removed from the Rank-Hilsch vortex tube into the high-pressure gas pipeline by a jet pump for mixing a high-pressure gas of an initial temperature with a cooled gas to lower the gas temperature in a high-pressure gas pipeline, and the ranca-Hilsch vortex tube is not enclosed in a thermostatic housing.

The problem is solved by the fact that in the "Gas control point" device containing a high-pressure gas pipeline with a thermometer, pressure gauges, a gas purification filter, a gas meter, a safety shut-off valve, a low (medium) outlet pressure gas pipeline with pressure gauges, a bypass pipeline, a Rank vortex tube -Hilsch, according to the invention, the Rank-Hilsch vortex tube is not enclosed in a thermostatic body, and the hot gas from the Rank-Hilsch vortex tube supplied to the pressure regulator with a built-in safety shut-off valve allows the pressure in the low (medium) outlet gas pipeline to be maintained stably at varying gas flow rate, and the cooled gas from the Rank-Hilsch vortex tube, discharged into the high-pressure gas pipeline by a jet pump for mixing the high-pressure gas of the initial temperature with the cooled one, makes it possible to lower the gas temperature in the high-pressure gas pipeline; the cooled high-pressure gas pipeline is located below the depth of soil freezing.

FIG. 1 shows a gas control station, where:

1. High pressure gas pipeline

2. Bypass pipeline

3. Cooled high pressure gas pipeline

4. Pressure gauge

5. Shut-off valves

6. Gas cleaning filter

7. Gas meter

8. Jet pump

9. Rank-Hilsch vortex tube

10. Pipeline for removal of cold gas

11. Branch pipe of a hot gas stream

12. Pressure regulator with built-in safety shut-off valve

13. Gas line of outlet low (medium) pressure

Thus, in the "Gas control station" device containing a high-pressure gas pipeline with a thermometer, pressure gauges, a gas purification filter, a gas meter, a safety shut-off valve, an outlet low (medium) pressure gas pipeline with pressure gauges, a bypass pipeline, a Rank-Hilsch vortex tube, the Ranque-Hilsch vortex tube is not enclosed in a thermostatic body, and from the Rank-Hilsch vortex tube the hot gas enters the pressure regulator with a built-in safety shut-off valve, which allows the pressure in the low (medium) outlet gas line to be maintained stably with varying gas flow rates, and the cooled gas from the Rank-Hilsch vortex tube is discharged into the high-pressure gas pipeline thanks to the jet pump. In this case, the high-pressure gas of the initial temperature mixes with the cooled one. The total gas temperature in the high pressure pipeline decreases. The cooled high-pressure gas pipeline is located below the depth of soil freezing, which allows the thermal energy of the earth to be taken off and the gas heated. This allows you to restore the temperature in the high-pressure gas pipeline to the next gas control point.

Gas control point operates as follows (Fig. 1).

High-pressure gas enters through the gas pipeline 1, located below the surface of the earth, through a branch to the gas control point. In the case of repair of the hydraulic fracturing, gas enters the low-pressure gas pipeline 13 through the bypass pipeline 2, equipped with shut-off valves. During normal operation of the hydraulic fracturing, the gas pressure at the inlet is measured (with a pressure gauge 4), and the gas sequentially passes through the shut-off valves 5, filter 6, gas meter 7. Then the gas enters the Rank-Hilsch vortex tube 9. Vortex tube 9 is a smooth cylindrical tube equipped with tangential nozzle, volute, diaphragm with axial bore and throttle. When gas enters the nozzle, an intense circular flow is formed, the axial layers of which are cooled and discharged through the diaphragm opening in the form of a cold flow into the pipeline 10. The peripheral layers are heated and flow out through the throttle in the form of a hot gas flow through the nozzle 11 and enter the pressure regulator with a built-in safety - a shut-off valve 12. In a pressure regulator with a built-in safety shut-off valve 12, the heated gas decreases its temperature due to a decrease in pressure. This prevents overcooling of the pressure regulator and the formation of hydrates. Further, the gas enters the low (medium) pressure gas pipeline 13, on which instrumentation is installed (pressure gauge 4). Gas from the cold gas outlet pipeline 10 is sucked in by the jet pump 8, mixed with the high pressure gas of the initial temperature and enters the cooled high pressure gas pipeline 3. The cooled high pressure gas pipeline 3 is laid below the soil freezing depth.

The use of the proposed device allows:

1. Prevent overcooling of the pressure regulator with built-in safety shut-off valve, as well as the low (medium) pressure pipeline of the gas control point.

2. To restore the temperature in the high pressure gas pipeline to the next gas control point, using the thermal energy of the earth.

3. Maintain a stable pressure with a varying gas flow rate at the outlet of the hydraulic fracturing.

4. Remove from the structure of the hydraulic fracturing the hermetically sealed thermostatic body, inside which the vortex tube is located.

Thus, the use of the claimed utility model makes it possible to prevent overcooling of the equipment elements of the gas control station and to ensure efficient and reliable operation of the gas control station.

Claims (2)

1. A method of operation of a gas control point, including the supply of high-pressure gas through a gas pipeline located below the earth's surface, measurement of gas pressure at the inlet with a pressure gauge, sequential passage of gas through shut-off valves, a filter, a gas meter with gas flow into the Rank-Hilsch vortex tube, hot gas from the Ranque-Hilsch vortex tube to a pressure regulator with a built-in safety shut-off valve for stable pressure maintenance in the downstream low pressure gas pipeline at varying gas flow rates, withdrawing the cooled gas from the Rank-Hilsch vortex tube into the high pressure gas pipeline by a jet pump for mixing high pressure gas the initial temperature with cooled to lower the gas temperature in the high-pressure gas pipeline, and the ranca-Hilsch vortex tube is not enclosed in a thermostatic housing. 2. A gas control station containing a high-pressure gas pipeline with a thermometer, pressure gauges, a gas purification filter, a gas meter, a safety shut-off valve, an outlet low (medium) pressure gas pipeline with pressure gauges, a bypass pipeline, a Rank-Hilsch vortex tube, characterized in that the vortex the Rank-Hilsch tube is not enclosed in a thermostatic body, but the hot gas from the Rank-Hilsch vortex tube supplied to the pressure regulator with a built-in safety shut-off valve makes it possible to stably maintain the pressure in the outlet low (medium) pressure gas pipeline with varying gas flow rates, while the cooled gas gas from the Rank-Hilsch vortex tube, discharged into the high-pressure gas pipeline by a jet pump for mixing the high-pressure gas of the initial temperature with the cooled one, makes it possible to lower the gas temperature in the high-pressure gas pipeline; the cooled high-pressure gas pipeline is located below the depth of soil freezing.

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