KR20170105979A - Apparatus for providing a fuel gas - Google Patents

Abstract

Provided is a fuel gas supply apparatus to prevent a contraflow of a high pressure fluid. According to an aspect of the present invention, the fuel gas supply apparatus comprises: a fuel tank; a pump for transferring fuel inside the fuel tank; a heat exchanger for thermally exchanging fuel transferred by the pump; an engine unit for receiving the thermally exchanged fuel; a driving unit for controlling the number of revolutions of the pump according to a load of the engine unit; a diverged pipe connected to the fuel tank by diverging between the pump and the heat exchanger; and a check valve installed in a path on which the heat exchanger and the fuel tank are connected.

Description

[0001] APPARATUS FOR PROVIDING A FUEL GAS [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a fuel gas supply apparatus, and more particularly, to a fuel gas supply apparatus that is configured to adjust a rotation speed of a fuel supply pump in accordance with a load of an engine unit, To a fuel gas supply device.

Generally, ships carrying Liquefied Natural Gas (LNG) carry liquefied natural gas at cryogenic temperatures of -163 ° C at normal pressure. The liquefied gas at a cryogenic temperature, that is, the LNG, is continuously supplied with heat due to a difference in temperature from the outside, thereby continuously generating boil-off gas (BOG). Recently, And the evaporation gas re-liquefaction device which is returned to the storage tank is installed to reduce waste of resources.

On the other hand, a high-pressure gas engine is an engine using high-pressure natural gas as a fuel, and it is necessary to supply a high-pressure gas.

The fuel gas supply device of the conventional LNG carrier is configured to extract LNG from the LNG storage tank, compress it with a high-pressure pump, vaporize it, and supply it to the high-pressure gas engine (engine for ship propulsion) (RPM) of the variable frequency drive (VFD) of the pump is controlled to control the pressure pump.

However, in the fuel gas supply apparatus of the related art, when the load of the engine portion is rapidly reduced, the RPM adjustment time in the drive portion is required to be longer than the load reduction time in the engine portion. Such a decrease in the engine load and the control time of the VFD become inconsistent, resulting in a time that is impossible to control by the VFD.

The high-pressure fluid existing in the piping between the engine section and the high-pressure pump during such a non-controllable period of time is discharged to the atmosphere through an OPV (Over Pressure Valve) as a pressure regulating means between the engine section and the heat exchanger, And is recovered to the fuel tank through a Minimum Flow Valve installed on the piping that branches off between the vessels and connects to the fuel tank.

However, when the high-temperature, high-pressure fluid flows backward during the uncontrollable time and moves to the fuel tank through the minimum flow rate valve, the fuel tank is impacted. In addition, the pipeline to which the minimum flow rate valve is connected has a liquid as a liquid. When the high temperature and high pressure fluid move to the pipeline, the liquid is vaporized and pressure may be generated, thereby damaging the pipeline.

Korean Patent Laid-Open No. 10-2013-0035058 (published on April 4, 2013)

The embodiments of the present invention provide a fuel gas supply apparatus for preventing reverse flow of high temperature and high pressure fluid which may be generated at the time of abrupt decrease of the engine load when the RPM of the drive unit (VFD) is controlled according to the load of the engine unit .

A fuel gas supply apparatus according to an embodiment of the present invention includes a fuel tank for storing liquefied gas; A liquefied gas supply line for pressurizing and liquefying the liquefied gas and supplying it to the engine section; A pump provided on the liquefied gas supply line for pressurizing the liquefied gas stored in the fuel tank; A heat exchanger for vaporizing the liquefied gas pressurized by the pump; A driving unit for controlling the number of revolutions of the pump in accordance with a load of the engine unit; A branch pipe branching between the pump of the liquefied gas supply line and the heat exchanger and connected to the fuel tank; And a check valve installed between the branch pipe branch point on the liquefied gas supply line and the heat exchanger.

Here, an automatic opening / closing valve may be provided at the front end or the rear end of the check valve.

The fuel gas supply device may further include a control unit for generating a control signal based on a load change of the engine unit and opening and closing the automatic on-off valve.

In the fuel gas supply apparatus according to the embodiments of the present invention, a regulator or an over-pressure valve (OPV) may be installed between the heat exchanger on the liquefied gas supply line and the engine unit.

According to the present embodiment as described above, since the check valve is provided to prevent the high temperature and high pressure fluid from flowing into the fuel tank or the branch pipe, it is possible to prevent the fuel tank or the pipe from being damaged by the high temperature and high pressure fluid .

Further, by providing the control unit and controlling the automatic opening / closing valve in accordance with the load of the engine unit, it is possible to provide a stable system even when the load of the engine unit changes.

1 is a configuration diagram of a fuel gas supply apparatus according to an embodiment of the present invention;
2 is a configuration diagram of a fuel gas supply apparatus according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In addition, the same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. For convenience of explanation, the size and shape of each constituent member shown may be exaggerated or reduced have.

On the other hand, terms including an ordinal number such as a first or a second may be used to describe various elements, but the constituent elements are not limited by the terms, and the terms may refer to a constituent element from another constituent element It is used only for the purpose of discrimination.

1 is a configuration diagram of a fuel gas supply apparatus according to an embodiment of the present invention.

1, a fuel gas supply apparatus according to an embodiment of the present invention includes a fuel tank 110, a high-pressure pump 140 for transferring the liquid fuel in the fuel tank 110, a high-pressure pump 140, A heat exchanger 160 for exchanging heat with the liquid fuel transferred from the heat exchanger 160, and an engine unit 170 receiving the gaseous fuel heat-exchanged from the heat exchanger 160.

A booster pump 120 is installed at the outlet of the fuel tank 110 to pressurize and discharge the discharged fuel.

The high-pressure pump 140 performs a function of again pressurizing the liquid fuel primarily pressurized by the boost pump 120 and transferring the pressurized liquid to the liquid of the higher pressure state.

Here, the high-pressure pump 140 is driven by a variable-frequency drive (VFD) 130, and the VFD 130 is configured to control the RPM of the high-pressure pump in accordance with the load of the engine 170.

Meanwhile, a check valve 145 may be installed in the discharge portion of the high-pressure pump 140 to prevent the backflow of the discharged fuel, which may be included in the configuration of the high-pressure pump 140.

The heat exchanger 160 is coupled to the discharge portion of the high-pressure pump 140 to heat-exchange the high-pressure liquid fuel transferred by the high-pressure pump 140.

Between the high-pressure pump 140 and the heat exchanger 160, a branch pipe 191 branched from the main pipe 121 and connected to the fuel tank 110 is provided.

A minimum flow valve 190 may be provided in the branch piping 191 to allow the minimum flow rate to be set even when the valve is locked.

The engine unit 170 is configured to allow gaseous fuel in a high-temperature and high-pressure state to be introduced from the heat exchanger 160 through the pipe 161.

The fuel gas supply apparatus according to an embodiment of the present invention is configured such that the high temperature and high pressure fuel which has been transferred to the heat exchanger 160 between the intersection of the main pipe 121 and the branch pipe 191 and the heat exchanger 160 A check valve 150 may be provided to prevent backflow.

Hereinafter, the process of moving the high-temperature and high-pressure fuel to the branch pipe 191 will be described in detail.

When the load on the engine 170 is rapidly reduced, the load on the engine 170 must decrease in about 10 seconds. However, in the VFD 130, about 30 seconds It takes about 20 seconds for the control to be impossible.

During this uncontrollable time, the high-temperature, high-pressure fluid between the high-pressure pump 140 and the engine 170 is transferred to the fuel tank 110 through the minimum flow rate valve 190, (181).

When a fluid of a high temperature and a high pressure is moved to the minimum flow valve 190 through the branch pipe 191, some fluid can move to the fuel tank 110 through the minimum flow valve 190, So that the fuel tank 110 can be impacted. In addition, a liquid fluid exists in the branch piping 191 in which the minimum flow rate valve 190 is located, and the liquid is vaporized while being in contact with the high-temperature and high-pressure fluid, and a pressure is generated to impinge on the branch piping 191 .

As described above, in order to prevent the impact of the fuel tank 110 and the branch pipe 191 due to the high temperature and high pressure fluid flowing backward, in an embodiment of the present invention, the main pipe 121 and the branch pipe 191 A check valve 150 may be provided between the intersection and the heat exchanger 160. The check valve 150 is an example only and the heat exchanger 160 and the fuel tank 110 are connected to each other via the branch pipe 191, It is possible to prevent the high temperature and high pressure fluid from flowing backward. However, in order to block the flow into the branch piping 191 and the fuel tank 110, it is preferable to install the branch pipe 191 near the inflow portion of the heat exchanger 160 as in the embodiment shown in FIG. 1, Is effective.

A regulator or an overpressure valve (OPV) may be installed between the heat exchanger 160 and the engine 170 to regulate the pressure. In an exemplary embodiment of the present invention, The pressure is regulated.

2 is a configuration diagram of a fuel gas supply apparatus according to another embodiment of the present invention.

2, a fuel gas supply apparatus according to another embodiment of the present invention includes a fuel tank 110, a high-pressure pump 140 for transferring the liquid fuel in the fuel tank 110, a high- A heat exchanger 160 for exchanging heat with the liquid fuel transferred from the heat exchanger 160, and an engine unit 170 receiving the gaseous fuel heat-exchanged from the heat exchanger 160.

In the embodiment of FIG. 2, a solenoid valve 155, which is an automatic opening / closing valve, and a control unit 200 that can control the solenoid valve 155 are further provided at the rear end of the check valve 150 shown in the embodiment of FIG. do. Although the check valve 145 provided at the discharge end of the high-pressure pump 140 included in FIG. 1 is shown as being excluded, the check valve 145 may be included.

The control unit 200 receives information on the load change of the engine unit 170 from the engine unit 170 and generates a control signal accordingly.

When the load of the engine 170 is suddenly decreased, the control unit 200 recognizes such a load change and generates a control signal for closing the solenoid valve 155, thereby constituting the solenoid valve 155 to be closed The function of the check valve 150 of the embodiment shown in Figs. 1 and 2 can be substituted.

In the embodiment of FIG. 2, the check valve 150 and the solenoid valve 155 are installed at the same time so that the high-temperature and high-pressure fluid flowing backward can be doubly closed. However, One of the valves 155 may be selectively installed.

2, the solenoid valve 155 is installed at the rear end of the check valve 150. However, unlike FIG. 2, the solenoid valve 155 may be installed at the front end of the check valve 150, 191).

The configuration corresponding to the reference numerals not described is already described in FIG.

Although not shown in the embodiment of FIG. 1, a solenoid valve (not shown) may be provided at the front end or the rear end of the check valve 150 to more reliably prevent the backflow prevention function.

Hereinafter, the operation of the fuel gas supply apparatus according to the present embodiment will be described.

First, the liquid fuel in the liquid state is transferred to the heat exchanger 160 by the high-pressure pump 140, is changed to the gas state, and then supplied to the engine unit 170.

The engine unit 170 burns the supplied fuel to produce a predetermined energy

At this time, the VFD 130 controls the RPM of the high-pressure pump 140 according to the load of the engine 170. When the load of the engine 170 is suddenly decreased, The RPM can not be controlled at the same time due to the decrease in the load of the part 170, so that the RPM can not be controlled for a predetermined time.

As a result, the high temperature, high pressure fluid between the high pressure pump 140 and the engine section 170 is controlled through the OPV 180 or the minimum flow valve 190.

At this time, the high-temperature and high-pressure gas tries to move in the direction of the minimum flow rate valve 190 due to the pressure difference, but the high-temperature and high-pressure gas can no longer be moved by the check valve 150 of the present invention.

As described above, the fuel gas supply apparatus according to the embodiment of the present invention prevents the high temperature and high pressure gas from being introduced into the liquid line or the fuel tank 110 by the check valve 150, It is possible to prevent the high temperature and high pressure fluid from being damaged by the high temperature and high pressure fluid.

In addition, as shown in the embodiment of FIG. 2, the control unit and the solenoid valve may be provided to replace the function of the check valve 150, or to prevent the backflow of the check valve 150, thereby providing a more reliable and stable system.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, many modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims. The present invention can be variously modified and changed by those skilled in the art, and it is also within the scope of the present invention.

110: fuel tank 120: boost pump
130: VFD 140: High pressure pump
145,150: Check valve 160: Heat exchanger
170: engine part 180: OPV
190: Minimum flow valve

Claims (4)

A fuel tank for storing liquefied gas;
A liquefied gas supply line for pressurizing and liquefying the liquefied gas and supplying it to the engine section;
A pump provided on the liquefied gas supply line for pressurizing the liquefied gas stored in the fuel tank;
A heat exchanger for vaporizing the liquefied gas pressurized by the pump;
A driving unit for controlling the number of revolutions of the pump in accordance with a load of the engine unit;
A branch pipe branching between the pump of the liquefied gas supply line and the heat exchanger and connected to the fuel tank; And
And a check valve installed between the branch pipe branching point on the liquefied gas supply line and the heat exchanger. The method according to claim 1,
Wherein an automatic opening / closing valve is provided at a front end or a rear end of the check valve. The method of claim 2,
Further comprising a control section for generating a control signal based on a load change of the engine section and opening / closing the automatic on-off valve. The method according to claim 1,
And a regulator or OPV (Over Pressure Valve) for adjusting the pressure is provided between the heat exchanger on the liquefied gas supply line and the engine.

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