KR20230094201A - System for providing fuel gas - Google Patents

Abstract

A fuel gas supply system is disclosed to supply fuel gas satisfying a methane level required by an engine. A fuel gas supply system according to an embodiment of the present invention comprises: a heat exchanger which lowers the temperature of natural gas separated from a crude oil mixture mined from a gas well or oil well to a set value by heat exchange; an expansion valve which expands the natural gas that has passed through the heat exchanger; and a gas-liquid separator which separates the expanded fluid into a gas component and a liquid component, wherein the gas component and the liquid component separated by the gas-liquid separator are supplied to the heat exchanger to perform heat exchange with natural gas, and the heat-exchanged gas component is supplied as fuel gas for an engine.

Description

Fuel gas supply system {SYSTEM FOR PROVIDING FUEL GAS}

The present invention relates to a fuel gas supply system.

Since the crude oil mixture flowing into the gas/oil production facility from a gas well or oil well is a mixture of various components, it is separated into liquid and gas components by a separator.

The separator can use gravity to separate a crude oil mixture into gas, crude oil and water. Crude oil separated by the separator is transferred to a storage tank through a residual gas and impurity removal facility, etc., and water can be returned to an oil well facility through an injection device or the like.

In addition, the gaseous natural gas separated by the separator may be supplied as fuel gas of the gas turbine, and the gas turbine may maintain operation of electricity production and production facilities using the same. As a prior art related to this, please refer to Korean Patent Publication No. 10-2013-0091135 (published on August 16, 2013).

However, the above-mentioned natural gas does not satisfy the methane number required by conventional engines because it contains a large amount of gas components of a polymer heavier than methane (CH4). Therefore, when natural gas is supplied as fuel for an engine, the output efficiency of the engine may be reduced, and excessive knocking and abnormal combustion may be caused.

This problem has become one of the main causes preventing the use of a gas engine or dual fuel engine as a main power generator in a conventional gas/crude production facility. Compared to gas engines, gas turbines require a large area or space for installation, require a long manufacturing period, low fuel efficiency, Equipment cost is high.

Therefore, there is a need to efficiently control the methane number of natural gas in order to supply natural gas produced in a gas/oil production facility as fuel to a gas engine or a dual fuel engine.

Korean Patent Publication No. 10-2013-0091135 (published on August 16, 2013)

An embodiment of the present invention is to provide a fuel gas supply system that supplies fuel gas according to the methane number required by an engine by lowering the temperature of natural gas separated from a crude oil mixture mined from a gas well or oil well and separating gas-liquid.

According to one aspect of the present invention, a heat exchanger for lowering the temperature of natural gas separated from a crude oil mixture mined in a gas well or oil well to a set value by heat exchange; An expansion valve for expanding the natural gas passing through the heat exchanger; and a gas-liquid separator for separating the expanded fluid into a gas component and a liquid component, wherein the gas component and liquid component separated by the gas-liquid separator are supplied to the heat exchanger to exchange heat with the natural gas, and the heat exchange A fuel gas supply system in which this gas component is supplied as fuel gas of the engine may be provided.

It is provided in front of the heat exchanger and may further include a moisture remover for removing moisture from natural gas separated from the crude oil mixture.

According to another aspect of the present invention, a heat exchanger for lowering the temperature of natural gas separated from a crude oil mixture mined in a gas well or oil well to a set value by heat exchange; a first gas-liquid separator provided at a rear end of the heat exchanger and separating the natural gas that has passed through the heat exchanger into a gas component and a liquid component; an expander for expanding the gas components separated by the first gas-liquid separator; and a second gas-liquid separator for separating the fluid that has passed through the expander into a gas component and a liquid component, wherein the liquid component separated by the first gas-liquid separator joins the liquid component separated by the second gas-liquid separator. A fuel gas supply system supplied to the heat exchanger may be provided.

Further comprising an expansion valve configured in parallel with the expander, the expansion valve may be driven to replace the expander during repair or maintenance of the expander.

A fuel supply line for supplying the gas component separated by the second gas-liquid separator to the engine through the heat exchanger, a compressor provided in the fuel supply line and compressing the fluid passing through the heat exchanger, and the compressed fluid It may further include a cooling unit for cooling by exchanging heat with a cooling medium, and a third gas-liquid separator for gas-liquid separation of the cooled fluid and supplying separated gas components toward the engine.

The compressor is connected to the expander by a shaft, and expansion energy of the expander may be used to drive the compressor.

The fuel gas supply system according to an embodiment of the present invention can supply fuel gas according to the methane number required by the engine by lowering the temperature of the natural gas separated from the crude oil mixture mined in the gas well or oil well and separating the gas and liquid.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 shows a fuel gas supply system according to an embodiment of the present invention.
2 shows a fuel gas supply system according to another embodiment of the present invention.
FIG. 3 shows a state in which a configuration for processing fuel supplied to an engine is added in the fuel gas supply system of FIG. 2 .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments introduced below are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. The present invention is not limited to the embodiments described below and may be embodied in other forms. In order to clearly explain the present invention, parts irrelevant to the description are omitted from the drawings, and in the drawings, the width, length, thickness, etc. of components may be exaggerated for convenience. Like reference numbers indicate like elements throughout the specification.

1 shows a fuel gas supply system according to an embodiment of the present invention.

1, the fuel gas supply system 100 according to an embodiment of the present invention is a heat exchanger (110) that lowers the temperature of natural gas separated from a crude oil mixture mined in a gas well or oil well to a set value by heat exchange. ), an expansion valve 120 for expanding the natural gas passing through the heat exchanger 110, and a gas-liquid separator 130 for separating the fluid expanded by the expansion valve 120 into a gas component and a liquid component. .

Here, the gas component and the liquid component separated by the gas-liquid separator 130 are supplied to the heat exchanger 110 to perform heat exchange with natural gas, and among them, the above-described gas component in which heat exchange is performed by the heat exchanger 110 may be supplied as fuel gas of the engine E.

In addition, the fuel gas supply system 100 is provided in front of the heat exchanger 110 and may include a moisture remover 105 for removing moisture from natural gas separated from the crude oil mixture.

In addition, the fuel gas supply system 100 may include an inhibitor injection line L12 for injecting a hydrate formation inhibitor into the natural gas from which water is removed by the water remover 105.

Hereinafter, each component of the fuel gas supply system 100 according to an embodiment of the present invention will be described in detail.

The fuel gas supply system 100 is, for example, various liquefied fuel carriers, liquefied fuel RV (Regasification Vessel), FPSO (Floating, Production, Storage and Off-loading), FSRU (Floating Storage and Regasification Unit), FPU (Floating Production Unit) It can be applied to various ships and offshore oil/gas production facilities such as , fixed platform, etc.

As shown in Figure 1, the natural gas separated from the crude oil mixture mined in the gas well or oil well is supplied to the heat exchanger 110 through the natural gas supply line (L11).

At this time, the moisture remover 105 is provided at the front end of the heat exchanger 110 to remove moisture from the natural gas separated from the crude oil mixture.

The moisture remover 105 may remove moisture contained in the natural gas separated from the crude oil mixture using, for example, triethylene glycol (TEG).

In addition, a hydrate formation inhibitor for preventing hydrate formation may be injected into the natural gas from which moisture is removed by the moisture remover 105 through the inhibitor injection line L12. For example, methanol, ethylene glycol, etc. may be used as a hydrate formation inhibitor.

The heat exchanger 110 receives natural gas from which moisture has been removed by the water remover 105 through a gas cooling line L11, and exchanges heat with a fluid supplied from a gas-liquid separator 130 to be described later to obtain natural gas. Lower the temperature to the set value.

The expansion valve 120 expands the aforementioned natural gas passing through the heat exchanger 110, and may include, for example, a Joule Thomson valve.

The gas-liquid separator 130 separates the fluid expanded by the expansion valve 120 into a gas component and a liquid component. At this time, the liquid component may include a liquid hydrocarbon (condensate) containing a high molecular weight hydrocarbon such as ethane, propane, butane, and pentane. The gas-liquid separator 130 may include, for example, a fuel gas scrubber.

The liquid component separated by the gas-liquid separator 130 passes through the heat exchanger 110 through the liquid component processing line L13, and the temperature and pressure are reduced by the LP (Low Pressure) separator 107 or MP (Medium Pressure) separator. It can be stored as oil after going through the process of stabilization step while adjusting.

In addition, the gas component separated by the gas-liquid separator 130 may be supplied to the engine E through the heat exchanger 110 through the fuel supply line L20.

At this time, the gas component separated by the gas-liquid separator 130 has a high methane component ratio, so it can satisfy the methane number required by the engine E. That is, the temperature of the natural gas is lowered by the heat exchanger 110 and the expansion valve 120 described above, and liquid hydrocarbons contained in the natural gas are separated by the gas-liquid separator 130, ) can increase the proportion of methane components contained in This has the effect of creating conditions for maintaining stable operation and performance of the engine E by satisfying the methane number required by the engine E.

2 shows a fuel gas supply system according to another embodiment of the present invention. Hereinafter, contents differentiated from those of FIG. 1 will be mainly described.

Referring to FIG. 2, as another example, the fuel gas supply system 100 includes a heat exchanger 110 that lowers the temperature of natural gas separated from a crude oil mixture mined in a gas well or oil well to a set value by heat exchange, and a heat exchanger (110) The first gas-liquid separator 140 provided at the rear and separating the natural gas that has passed through the heat exchanger 110 into a gas component and a liquid component, and the gas component separated by the first gas-liquid separator 140 It may include an expander (150, expander) for expanding and a second gas-liquid separator 160 for separating the fluid that has passed through the expander 150 into a gas component and a liquid component.

Here, the liquid component separated by the first gas-liquid separator 140 is joined to the liquid component separated by the second gas-liquid separator 160 through the joining line L14 and supplied to the heat exchanger 110, and then, After going through a stabilization step process while the temperature and pressure are adjusted by the LP separator 107 or the MP separator, it can be stored as oil.

In addition, an extra expansion valve 155 configured in parallel with the expander 150 may be provided in the fuel gas supply system 100 . That is, the gas component separated by the first gas-liquid separator 140 at normal times may be supplied to the second gas-liquid separator 160 via the expander 150 . In addition, when repair or maintenance of the expander 150 is required, the expansion valve 155 may be operated in place of the expander 150 .

FIG. 3 shows a state in which a configuration for processing fuel supplied to an engine is added in the fuel gas supply system of FIG. 2 . Hereinafter, contents differentiated from those of FIG. 2 will be mainly described.

Referring to FIG. 3, as another example, in the fuel gas supply system 100 of FIG. 2 described above, the gas component separated by the second gas-liquid separator 160 is supplied to the engine E via the heat exchanger 110. A fuel supply line (L20) provided in the fuel supply line (L20) and a compressor 170 for compressing the fluid passing through the heat exchanger 110, and the fluid compressed by the compressor 170 with a cooling medium. A cooling unit 180 for cooling by heat exchange and a third gas-liquid separator 190 for gas-liquid separation of the fluid cooled by the cooling unit 180 and supplying the separated gas components to the engine E may be provided.

The aforementioned compressor 170 may compress the fluid passing through the heat exchanger 110 on the fuel supply line L20 according to the supply conditions of the engine E. The compressor 170 may be used when the engine E requires high-pressure fuel gas. Compressor 170 may be a multi-stage compressor including means for alternately performing compression and cooling. Since the gas components separated by the second gas-liquid separator 160 contain high methane components as described above, the methane number required by the engine E can be satisfied. The compressor 170 may supply the gas component separated by the second gas-liquid separator 160 passing through the heat exchanger 110 toward the engine E through the fuel supply line L20.

The compressor 170 may be connected to the expander 150 by a shaft (X, Shaft). At this time, at least some of the gas components separated by the first gas-liquid separator 140 are supplied to the second gas-liquid separator 160 via the expander 150, and are moved to the shaft X by the expansion energy of the expander 150. A connected compressor 170 may be driven.

The cooling unit 180 heat-exchanges the fluid compressed by the compressor 170 with a cooling medium to cool the engine E according to fuel supply conditions.

For example, seawater may be used as a cooling medium, and seawater may be supplied toward the cooling unit 180 through the seawater supply line L22. At this time, although not shown, a seawater pump is used and seawater may be continuously supplied toward the cooling unit 180 through the seawater supply line L22.

The third gas-liquid separator 190 gas-liquid separates the fluid cooled by the cooling unit 180 and supplies the separated gas components to the engine E.

As such, the present invention can supply fuel gas according to the methane number required by the engine by lowering the temperature of the natural gas separated from the crude oil mixture mined in the gas well or oil well through the above-described embodiment, and gas-liquid separation.

In the above, specific embodiments have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various changes without departing from the gist of the technical idea set forth in the claims below. You will be able to.

105: water eliminator 110: heat exchanger
120: expansion valve 130: gas-liquid separator
140: first gas-liquid separator 150: expander
155: expansion valve 160: second gas-liquid separator
170: compressor 180: cooling unit
190: third gas-liquid separator L11: gas cooling line
L12: inhibitor injection line L13: liquid component processing line
L14: confluence line L20: fuel supply line
L22: seawater supply line

Claims (5)

A heat exchanger that lowers the temperature of natural gas separated from a crude oil mixture extracted from a gas well or oil well to a set value by heat exchange;
An expansion valve for expanding the natural gas passing through the heat exchanger; and
A gas-liquid separator for separating the expanded fluid into a gas component and a liquid component; including,
The gas component and the liquid component separated by the gas-liquid separator are supplied to the heat exchanger to exchange heat with the natural gas,
The gas component subjected to the heat exchange is supplied as fuel gas of the engine. According to claim 1,
A fuel gas supply system further comprising a moisture remover provided at a front end of the heat exchanger and removing moisture from natural gas separated from the crude oil mixture. A heat exchanger that lowers the temperature of natural gas separated from a crude oil mixture extracted from a gas well or oil well to a set value by heat exchange;
a first gas-liquid separator provided at a rear end of the heat exchanger and separating the natural gas that has passed through the heat exchanger into a gas component and a liquid component;
an expander for expanding the gas components separated by the first gas-liquid separator; and
A second gas-liquid separator for separating the fluid that has passed through the expander into a gas component and a liquid component; including,
The liquid component separated by the first gas-liquid separator is joined to the liquid component separated by the second gas-liquid separator and supplied to the heat exchanger. According to claim 3,
Further comprising an expansion valve configured in parallel with the expander,
A fuel gas supply system in which the expansion valve is driven by replacing the expander during repair and maintenance of the expander. According to claim 4,
A fuel supply line for supplying the gas component separated by the second gas-liquid separator to the engine through the heat exchanger;
A compressor provided in the fuel supply line and compressing the fluid passing through the heat exchanger;
A cooling unit for cooling the compressed fluid by exchanging heat with a cooling medium;
The fuel gas supply system further comprises a third gas-liquid separator for gas-liquid separation of the cooled fluid and supplying the separated gas component toward the engine.

Images