KR20190064048A - Natural Gas Pressure Regulating Eqiupment Commissioning System - Google Patents

Abstract

The present invention relates to a trial running system for a pressure regulating facility of natural gas and a trial running method for the same, capable of reducing the risk of an accident and production costs by not using natural gas in a trial run of a pressure regulating facility of the natural gas. According to the present invention, the trial running system for a pressure regulating facility of natural gas includes: a pressure regulating device decompressing the natural gas and supplying the decompressed natural gas to a place demanding gas at a fixed pressure; a feeder firstly decompressing the pressure of the natural gas supplied to the pressure regulating device to be higher than the pressure of the natural gas supplied from the pressure regulating device to the place demanding the gas; a pilot controlling an opening and closing rate of the pressure regulating device by secondly decompressing the natural gas firstly decompressed by the feeder and supplying the same to the pressure regulating device; and a nitrogen tank storing nitrogen. The trial running system for a pressure regulating facility of natural gas also includes: a first nitrogen line connected for the nitrogen stored in the nitrogen tank to be supplied to the feeder; and a second nitrogen line connected for the nitrogen stored in the nitrogen tank to be supplied to the pressure regulating device. So, the trial running system for a pressure regulating facility of natural gas can perform the trial run using the nitrogen stored in the nitrogen tank in the trial run of the pressure regulating device.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a natural gas pressure regulating system,

The present invention relates to a commissioning system and a commissioning method for a natural gas static pressure facility which can avoid the use of natural gas during commissioning of a natural gas static pressure facility, reduce the risk of accidents, and reduce costs.

Liquefied natural gas (LNG) imported through an LNG carrier is stored in landfill storage tanks through the cargo handling facility and is then vaporized from the vaporization plant and supplied to the governor station. The gasification plant delivers heat exchange efficiency of natural gas and high pressure, for example around 70 bar, in order to increase the transport density from the gasification plant to the supply station.

From the supply station, gas supply is provided to natural gas demand sites such as power plants and city gas companies at each branch of the nation. At this time, the supply station uses the static pressure equipment to reduce the vaporized gas supplied from the gasification equipment to a certain pressure and supply it to the natural gas demand place.

In this way, the number of static pressure installations installed nationwide is about one hundred (domestic), and various types of standardized static pressure installations are installed and operated. In addition, the nationwide gas pipeline is expanding due to the surge in demand for natural gas, which is a clean energy, and the number of static pressure installations is continuously increasing.

Generally, a static pressure equipment is constituted by a regulator in which a depressurization is practically performed and a Slam Shut Valve provided in a rear stage of the pressure regulator are connected in series. The slam shut valve automatically closes when the pressure of the downstream side of the regulator increases beyond the set pressure due to abnormal occurrence of the regulator, thereby preventing the downstream pressure of the regulator from rising to a dangerous level.

In order to test the static pressure equipment, for example, to set the operating pressure, or temporarily or regularly check the abnormality, the shut-off valve installed in the back-end pipe of the regulator is closed and the regulator is operated to artificially increase the pressure after the regulator, Test the shut valve for normal operation and set the operating pressure.

At this time, since the flow of natural gas through the static pressure equipment must be continued, the vent hose is connected to the rear end pipe of the regulator, the shutoff valve provided at the rear end pipe of the regulator is opened, and natural gas is discharged to the atmosphere through the vent hose . The discharged natural gas is artificially raised in pressure for commissioning, so it can not be supplied to the natural gas demand place beyond the proper supply pressure.

The amount of natural gas to dissipate for commissioning is approximately 186 Nm ³ per test. In other words, unnecessary dissipation of natural gas causes not only economic loss, but also the environmental pollution of releasing natural gas, which is the main component of methane, into the atmosphere.

In addition, since natural gas is a combustible material and explosive, and static pressure equipment is installed in a closed space, artificially compressing natural gas to a high pressure for trial operation is a risk of safety accidents.

In addition, there is a problem that it is difficult to calculate the exact quantity of natural gas required for commissioning depending on the situation, because the capacity of the static pressure facility differs for each supply station.

That is, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a commissioning system for a natural gas constant-pressure facility capable of safely and efficiently performing commissioning of a static pressure facility without using natural gas.

According to an aspect of the present invention, there is provided a gas turbine comprising: a regulator for decompressing natural gas and supplying it to a gas consumer at a constant pressure; A feeder for primarily depressurizing the pressure of the natural gas supplied to the pressure regulator to a pressure higher than a pressure of natural gas supplied to the gas consumer from the regulator; A pilot for controlling a degree of opening and closing of the regulator by supplying the regenerator with the first reduced pressure natural gas from the feeder, And a nitrogen tank for storing nitrogen, the first nitrogen line being connected so that nitrogen stored in the nitrogen tank is supplied to the feeder; And a second nitrogen line connected to supply the nitrogen stored in the nitrogen tank to the regulator so as to perform trial operation using nitrogen stored in the nitrogen tank at the time of trial operation of the regulator, A commissioning system is provided.

Preferably, the feeder further comprises a third nitrogen line, connected to the lower space in the feeder, for containing nitrogen stored in the nitrogen tank, the nitrogen line being separated by the diaphragm into an upper space and a lower space can do.

Preferably, the first valve regulates the pressure of the nitrogen flowing through the first nitrogen line constantly; A second valve for constantly controlling the pressure of nitrogen flowing through the second nitrogen line; And a third valve for regulating the pressure of nitrogen flowing through the third nitrogen line to a constant value.

Preferably, a lower connection line connecting the regulator and the pilot; And a re-circulation line connecting the outlet side of the regulator to the feeder and the pilot, and a differential pressure gauge measuring a pressure difference between the pressure of the lower connection line and the pressure of the recirculation line.

The commissioning system for the natural gas static pressure facility according to the present invention can perform the trial operation of the static pressure facility using the inert gas without using the natural gas, thereby preventing waste of unnecessary natural gas, There is an effect of prevention.

In addition, since the natural gas is not used for the commissioning, the possibility of a safety accident can be prevented, and the incidental costs can be reduced.

In addition, conventionally, it was difficult to accurately calculate the amount of defense products due to the difference in time required for commissioning depending on the time required for commissioning and the capacity of each facility. However, by separately providing a commissioning device, yield accuracy can be improved, You can contribute.

In addition, standards for commissioning, such as regular maintenance of static pressure equipment, can be suggested.

1 is a schematic view illustrating a test operation system of a natural gas static pressure facility according to an embodiment of the present invention.

In order to fully understand the operational advantages of the present invention and the objects attained by the practice of the present invention, reference should be made to the accompanying drawings, which illustrate preferred embodiments of the present invention, and to the contents of the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals refer to like elements throughout. The same elements are denoted by the same reference numerals even though they are shown in different drawings. In addition, the following examples can be modified in various forms, and the scope of the present invention is not limited to the following examples.

In the embodiment of the present invention described below, the present invention is applied to a static pressure equipment for depressurizing high-pressure natural gas transferred from a vaporization equipment to low pressure. However, the trial operation system of the natural gas constant- Alternatively, the present invention can be applied to a regasification gas in which a liquefied gas capable of being transported by liquefying the gas at a low temperature is vaporized. The liquefied gas may be, for example, liquefied petroleum gas such as Liquefied Natural Gas (LNG), Liquefied Ethane Gas (LEG), Liquefied Petroleum Gas (LPG), Liquefied Ethylene Gas and Liquefied Propylene Gas It may be a chemical gas.

Hereinafter, a commissioning system for a natural gas static pressure facility according to an embodiment of the present invention will be described with reference to FIG. The commissioning system for a natural gas pressure regulator according to an embodiment of the present invention is applied for commissioning a natural gas gas pressure regulator according to an embodiment of the present invention.

First, referring to FIG. 1, a natural gas static pressure facility according to an embodiment of the present invention will be described. The natural gas static pressure facility according to the present embodiment includes a regulator 100; A feeder 200; A pilot 300; And a slam shut down device (not shown).

The pressure regulator 100 of the present embodiment is a device for reducing the high pressure front end pressure P _u to a low pressure end pressure P _d within a set value range to supply natural gas to a gas consumer at a constant pressure.

The regulator 100 includes a regenerator inlet 110 through which a high pressure P _u natural gas flows into the regulator 100 and a regulated low pressure P _d natural gas discharged from the regulator 100 at a constant pressure And a pressure regulator outlet (120).

The regulator inlet 110 is connected to a supply source for supplying high-pressure natural gas to regulate the pressure. For example, the pressure regulator inlet 110 may be connected to an outlet of a vaporization plant that vaporizes Liquefied Natural Gas (LNG). The vaporization equipment may include, for example, a high pressure pump and a vaporizer.

The outlet 120 of the regulator is connected to a customer who is supplied with the pressure-regulated low-pressure natural gas at a constant pressure. For example, the regulator outlet 120 may be connected to a natural gas consumer, such as a power plant and a city gas company.

The feeder 200 of this embodiment is a device that always supplies the same pressure to the pilot 300, which will be described later.

The pilot 300 of this embodiment controls the regulator 100 and adjusts the back pressure of the pilot 300 according to the back pressure of the regulator 100. [ The back pressure of the pilot 300 is the pressure acting on the lower portion of the diaphragm of the pressure regulator 100.

Although not shown in the drawing, inside the pressure regulator 100, the feeder 200, and the pilot 300 of the present embodiment, a chamber, which is the path of the fluid, is provided. A diaphragm for isolating the chamber into two spaces; And the degree of opening and closing of the chamber is adjusted by the balance of the pressure acting on the upper and lower portions of the diaphragm, thereby adjusting the pressure of each rear end.

As shown in FIG. 1, the natural gas constant-pressure system according to the present embodiment includes a path through which the fluid flows from the inlet of the reformer 110 to the feeder 200, connecting the inlet of the reformer 110 to the feeder 200, Feeder feed line (u1); And a pilot supply line up1 that connects the feeder 200 and the pilot 300 and is a path through which the fluid flows from the feeder 200 to the pilot 300. [

A lower connection line m1 that connects the pilot 300 and the pressure regulator 100 and is a path through which fluid flows from the pilot 300 to the regulator 100; And the pilot supply line up1 and connected to the regulator 100 so that fluid flowing in the pilot supply line up1 flows into the regulator 100 or fluid flows from the regulator 100 to the pilot supply line up1, And an upper connection line up2 which is a flow path.

A recirculation line d1 that connects the regulator outlet 120 and the feeder 200 and is a path through which the fluid flows from the regulator outlet 120 to the feeder 200; And a pilot recirculation line (d2) that branches from the recirculation line (d1) and connects the regulator outlet (120) to the pilot (300) and is a path through which fluid flows from the regulator outlet (120) to the pilot .

A slam shutdown valve (not shown) is a type of safety device that is installed under the regulator 100, is connected to the regulator outlet 120, and operates when the pressure of the regulator outlet 120 abnormally increases.

Hereinafter, the operation principle of the natural gas static pressure facility according to the present embodiment will be described.

First, the feeder 200 feeds the front end pressure P _u of the regulator 100 supplied to the feeder 200 through the feeder feed line u1 to the rear end pressure P _d of the regulator 100 by about 1.2 To a pressure of _up to 1.5 bar (P _up ), so that a constant pressure (P _up ) can be supplied to the pilot 300 through the pilot supply line up1. Here, about 1.2 to 1.5 bar may be the same value as the initial load of the spring (not shown) of the pilot 300.

At this time, the gap between the pad (not shown) inside the feeder 200 and the sleeve (not shown) inside the feeder 200 is adjusted by the left / right or up / down movement, When the set point is determined, that is, when the posterior pressure P _up after the feeder 200 is determined, the sleeve stops at the position, and the position is adjusted again when the set value is changed.

The force acting on the upper part of the diaphragm in the feeder 200 is the back pressure P _up of the feeder 200 and the force acting on the lower part is the back pressure P _d of the pressure regulator 100, The degree of opening and closing of the feeder 200 is determined.

For example, if the force acting on the upper portion of the diaphragm inside the feeder 200 is smaller than the force acting on the lower portion, that is, 'P _up <P _d ' Is more opened, the flow rate of the fluid is increased, and the back pressure (P _up ) of the feeder 200 is increased.

The pilot 300 is sent by setting pressure governor to maintain a constant 100 in the pressure (P _m) adjusted to the opening degree of the (P _d) through lower connecting lines (m1). At this time, the pressure regulated in the pilot 300 is supplied to the lower portion of the diaphragm of the pressure regulator 100. That is, the force acting on the lower portion of the diaphragm of the pressure regulator 100 is the sum of the _{rear end} pressure P _m of the pilot 300 and the spring load P _rspring of the regulator 100.

The chamber inside the pilot 300 is always filled with the set pressure P _d and the fluid is supplied from the feeder 200 in accordance with the movement of the moving part,

The force acting on the upper portion of the diaphragm inside the pilot 300 is the set pressure P _d and the force acting on the lower portion is the spring load P _pspring of the pilot 300, The degree of opening and closing of the door 300 is determined.

For example, if the force acting on the upper portion of the diaphragm inside the pilot 300 is smaller than the force acting on the lower portion, i.e., 'P _d <P _pspring ', the force acting on the lower portion is greater, 300 is more opened, the flow rate of the fluid is increased, and after the pilot 300 is increased danap (P _m).

The upper chamber inside the pressure regulator 100 is filled with the feeder back pressure P _up through the upper connection line up2 and the lower chamber is fed through the lower connection line m1 to the post- _m ).

That is, the governor 100, the force acting on the upper portion of the inner diaphragm set pressure (P _d), and the force is the spring load of after the pilot 300 danap (P _m) and a governor 100, which acts on the bottom (P _rspring ), and the opening / closing degree of the pressure regulator 100 is determined according to the balance of the two pressures.

The degree of opening and closing of the pressure regulator 100 is determined by the difference between the spring load P _rspring in the regulator 100 and the load of the moving part, that is, the difference between the rear end pressure P _up of the feeder 200, Is determined by the back pressure (P _m ).

For example, in order to increase the gas flow rate supplied to the gas consumer through the outlet of the regulator 100, the force acting on the lower portion of the inner diaphragm of the regulator 100, that is, the post- _{lt; RTI ID} = 0.0 &_gt; _m ) &lt; / RTI &gt; As a result, the fluid flow rate at the outlet of the regulator 100 becomes large, and the post-end pressure P _{d of the} regulator 100 becomes high. This is performed until the post-end pressure P _{d of the} pressure regulator 100 reaches the set value.

The natural gas static pressure facility according to the present embodiment includes a lock-up valve (not shown) for closing the static pressure generator 100 in a no-flow condition.

The above-mentioned static pressure equipment for natural gas should be commissioned such as start-up, periodical checks and maintenance of operating condition and sealing, It is common to supply gas to the static pressure equipment and vent gas to the atmosphere because the natural gas used for commissioning can not be supplied to the gas consumer.

However, the commissioning system of the natural gas static pressure facility according to the present embodiment includes a commissioning apparatus. The commissioning apparatus according to the present embodiment may be installed in a box and closed.

A test apparatus for a natural gas static pressure facility according to an embodiment of the present invention includes a nitrogen tank 400; A first nitrogen line i1 which connects the nitrogen tank 400 and the feeder feed line u1 and from which the nitrogen flows from the nitrogen tank 400 to the feeder feed line u1; A second nitrogen line i2 which connects the nitrogen tank 400 and the lower connection line m1 and is a path through which nitrogen flows from the nitrogen tank 400 to the lower connection line m1; And a third nitrogen line i3 that connects the nitrogen tank 400 and the recycle line d1 and is the path through which nitrogen flows from the nitrogen tank 400 to the recycle line d1.

According to the present embodiment, the lower connection line m1 is provided with a first point P1 as a pressure measurement spot of the lower connection line m1, and the recirculation line d1 is provided with a pressure And a second point P2 that is a measurement spot.

The first point P1 may be located downstream of the point at which the second nitrogen line i2 joins the lower connection line m1.

The second point P2 may be located downstream of the point at which the third nitrogen line i3 joins the recirculation line d1.

The test apparatus according to the present embodiment further includes a differential pressure gauge 500 for measuring the pressure difference between the first point P1 and the second point P2 to confirm whether the static pressure facility is normally operated or leaked .

The first nitrogen line i1 is controlled by a control unit (not shown), and the flow rate and pressure of nitrogen flowing through the first nitrogen line i1 are controlled so that nitrogen is supplied from the nitrogen tank 400 at a constant flow rate and pressure A first valve (v1) for flowing into the feeder feed line (u1); And a first pressure transmitter (not shown) for measuring the pressure of the first nitrogen line i1. The first valve (v1) may be installed upstream of the first pressure transmitter.

 The second nitrogen line (i2) is controlled by a control unit (not shown), and the flow rate and pressure of nitrogen flowing through the second nitrogen line (i2) are controlled so that nitrogen is supplied to the nitrogen tank ) To the lower connecting line (m1); And a second pressure transmitter (not shown) for measuring the pressure of the second nitrogen line i2. The second valve (v2) may be installed upstream of the second pressure transmitter.

The third nitrogen line (i3) is controlled by a control unit (not shown), and the flow rate and pressure of nitrogen flowing through the third nitrogen line (i3) are controlled so that nitrogen is supplied to the nitrogen tank ) To the recirculation line (d1); And a third pressure transmitter (not shown) for measuring the pressure of the third nitrogen line i3. The third valve (v1) may be installed upstream of the third pressure transmitter.

In this embodiment, the nitrogen gas is used for the trial operation of the natural gas constant-pressure equipment. However, the present invention is not limited thereto, and an inert gas such as nitrogen may be used. That is, the name 'nitrogen' in the present embodiment may be understood as an inert gas.

According to this embodiment, when the natural gas constant-pressure facility is operated, the natural gas is not supplied to the natural gas static pressure facility, and the nitrogen gas is supplied from the nitrogen tank 400 through the first to third nitrogen lines i1, i2, It is possible to perform a trial operation.

The nitrogen gas flowing through the first to third nitrogen lines i1, i2, i3 can flow at a constant pressure by the first to third valves v1, v2, v3.

The control unit (not shown) opens the first valve (v1) and the third valve (v3) and performs nitrogen gas supply through the first nitrogen line (i1) and the third nitrogen line (200). The nitrogen gas flowing along the third nitrogen line i3 may also be supplied to the pilot 300 via the pilot recirculation line d2. The second valve v2 is also opened to supply the nitrogen gas to the reactor 100 via the second nitrogen line i2 and the lower connection line m1.

Therefore, according to the embodiment of the present invention described above, when the start-up of the natural gas static pressure facility is performed, or when the pressure set value of the natural gas static pressure facility is checked or reset, When performing the periodic inspection, it is possible to prevent a safety accident at the time of commissioning by using inert gas such as nitrogen without using natural gas, and unnecessary waste of natural gas And the flow rate of the inert gas used in the test run can be confirmed, thereby improving the yield accuracy.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or scope of the invention as defined in the appended claims. . Therefore, the above-described embodiments are to be considered as illustrative rather than restrictive, and thus the present invention is not limited to the above description, but may be modified within the scope of the appended claims and equivalents thereof.

100: Regulator
110: inlet of regulator
120: Regulator outlet
200: feeder
300: Pilot
400: nitrogen tank
500: Differential pressure gauge
u1: feeder feed line
up1: pilot supply line
up2: Upper connection line
m1: Lower connection line
d1: recirculation line
d2: pilot recirculation line
i1 to i1: first to third nitrogen lines
v1 to v3: first to third valves

Claims (4)

A regulator for reducing the pressure of natural gas and supplying the natural gas to a consumer with a constant pressure;
A feeder for primarily depressurizing the pressure of the natural gas supplied to the pressure regulator to a pressure higher than a pressure of the natural gas supplied to the gas consumer from the regulator;
A pilot for controlling a degree of opening and closing of the regulator by supplying the regenerator with the first reduced pressure natural gas from the feeder, And
A nitrogen tank for storing nitrogen,
A first nitrogen line connected to feed the nitrogen stored in the nitrogen tank to the feeder; And
And a second nitrogen line connected to supply the nitrogen stored in the nitrogen tank to the regulator,
And a test operation is performed using nitrogen stored in the nitrogen tank at the time of trial operation of the pressure regulator. The method according to claim 1,
The feeder
And a chamber isolated by the diaphragm into an upper space and a lower space,
And a third nitrogen line connected to supply the nitrogen stored in the nitrogen tank to the lower space in the feeder. The method of claim 2,
A first valve for constantly controlling the pressure of nitrogen flowing through the first nitrogen line;
A second valve for constantly controlling the pressure of nitrogen flowing through the second nitrogen line; And
A third valve for constantly regulating the pressure of nitrogen flowing through said third nitrogen line; a commissioning system for a natural gas static pressure facility, The method according to claim 1 or 2,
A lower connection line connecting the regulator and the pilot; And
And a recirculation line connecting an outlet side of the regulator with a feeder and a pilot,
And a differential pressure gauge for measuring a pressure difference between the pressure of the lower connection line and the pressure of the recirculation line.

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