KR101810734B1 - Treatment system of liquefied natural gas and driving method the same - Google Patents

Abstract

A liquefied gas processing system according to an embodiment of the present invention includes: a boosting pump for supplying liquefied gas stored in a storage tank; A high pressure pump for pressurizing the liquefied gas supplied from the boosting pump; A first recovery line connected to the storage tank from inside the high-pressure pump to recover the liquefied gas; A second recovery line for recovering the liquefied gas from the downstream of the high-pressure pump to the storage tank; And a control unit for causing the high pressure pump to stand by when the standby mode continues for a predetermined time or more.
A method of driving a liquefied gas processing system according to an embodiment of the present invention includes: supplying liquefied gas stored in a storage tank to a customer through a boosting pump or a high-pressure pump; Performing a standby mode to wait for supply of the liquefied gas to the customer; Collecting the liquefied gas introduced into the high-pressure pump into a storage tank; And waiting for the operation of the high-pressure pump when the standby mode time exceeds the preset time, when the standby mode time exceeds the preset time.
The liquefied gas processing system and the method of driving the same according to the present invention can operate and maintain the high pressure pump in accordance with the waiting time of the LNG supply in the standby mode to efficiently operate the high pressure pump with high power consumption, It is effective.
In addition, the present invention keeps the devices operating in the gas mode in the stand-by mode changing from the oil mode to the gas mode continuously without stopping, thereby enabling stable and rapid supply of gas to the customer.

Description

[0001] The present invention relates to a liquefied gas processing system and a method for driving the same,

The present invention relates to a liquefied gas processing system and a method of driving the same.

A ship is a means of transporting large quantities of minerals, crude oil, natural gas, or several thousand containers. It is made of steel and buoyant to float on the water surface. The thrust generated by rotation of the propeller ≪ / RTI >

Such a ship generates thrust by driving the engine. At this time, the engine uses gasoline or diesel to move the piston so that the crankshaft is rotated by the reciprocating motion of the piston, so that the shaft connected to the crankshaft is rotated, .

In recent years, however, LNG LNG supply systems for driving an engine using LNG as an LNG carrier have been used in an LNG carrier carrying Liquefied Natural Gas (LNG) It is also applied to other ships.

Generally, it is known that LNG is clean LNG and its reserves are more abundant than petroleum, and its usage is rapidly increasing as mining and transportation technology develops. This LNG is generally stored in a liquid state at a temperature of -162 ° C below 1 atm under the pressure of 1 atm. The volume of liquefied methane is about 1/600 of the volume of the gaseous methane in the standard state, Is 0.42, which is about one half of the specific gravity of crude oil.

However, the temperature and pressure required to drive the engine may be different from the state of the LNG stored in the tank. Therefore, in recent years, research and development have been made on the technology of controlling the temperature and pressure of the LNG stored in the liquid state and supplying the engine to the engine.

SUMMARY OF THE INVENTION The present invention has been made to improve the conventional technology, and it is an object of the present invention to provide a fuel cell system which can induce stable and quick operation of the engine in a standby mode in which the fuel supply system is changed from the oil mode to the gas mode, And a method for driving the same.

A liquefied gas processing system according to the present invention comprises: a boosting pump for supplying liquefied gas stored in a storage tank; A high pressure pump for pressurizing the liquefied gas supplied from the boosting pump; A first recovery line connected to the storage tank from inside the high-pressure pump to recover the liquefied gas; A second recovery line for recovering the liquefied gas from the downstream of the high-pressure pump to the storage tank; And a control unit for causing the high pressure pump to stand by when the standby mode continues for a predetermined time or more.

Specifically, when the standby mode is started, the control unit operates both the boosting pump and the high-pressure pump to recover the liquefied gas to the storage tank through the second recovery line, and when the standby mode is exceeded , The high pressure pump can be put on standby and the liquefied gas can be recovered to the storage tank through the first recovery line.

Specifically, a fuel supply line may be connected from the storage tank to a customer, and the second recovery line may be connected to the storage tank from the downstream of the high-pressure pump on the fuel supply line.

Specifically, the first recovery line may include a first valve that performs opening or closing; And a second valve formed of a three-way valve at a point where the second recovery line and the fuel supply line are connected to each other.

Specifically, when the standby mode is started, the control unit closes the fuel supply line between the high-pressure pump and the demander through the second valve, opens the second recovery line, , It is possible to close the fuel supply line between the second recovery line and the high pressure pump and the demand place through the second valve and open the first recovery line.

Specifically, the control unit may open the first recovery line according to the standby mode time or open the second recovery line to recover the liquefied gas.

Specifically, when the standby mode is less than the preset time from the start of the standby mode time, the control unit cuts off the downstream of the high-pressure pump, and the second recovery line is opened to recover the liquefied gas.

Specifically, when the standby mode is equal to or longer than the preset time, the control unit may disconnect the outlet of the high-pressure pump and open the first recovery line to recover the liquefied gas.

A method for driving a liquefied gas processing system according to the present invention comprises the steps of: supplying liquefied gas stored in a storage tank to a customer through a boosting pump or a high-pressure pump; Performing a standby mode to wait for supply of the liquefied gas to the customer; Collecting the liquefied gas introduced into the high-pressure pump into a storage tank; And waiting for the operation of the high-pressure pump when the standby mode time exceeds the preset time, when the standby mode time exceeds the preset time.

Specifically, when the standby mode is terminated, the high pressure pump may be restarted to resume the supply of the liquefied gas to the customer.

Specifically, the step of recovering the liquefied gas introduced into the high-pressure pump to the storage tank may block the downstream of the high-pressure pump and recover the liquefied gas to the storage tank.

Specifically, in the step of performing the standby mode for waiting for supply of the liquefied gas to the customer, the operation of the boosting pump and the high-pressure pump can be maintained.

Specifically, when the standby mode is equal to or longer than the preset time, the step of waiting for the operation of the high-pressure pump is maintained, and the operation of the high-pressure pump can be waited for.

Specifically, when the standby mode is equal to or longer than the predetermined time, waiting for operation of the high-pressure pump may be such that liquefied gas flowing into the high-pressure pump through the boosting pump is recovered to the storage tank.

Specifically, when the standby mode is less than the predetermined time, the supply of the liquefied gas to the customer can be resumed at the end of the standby mode.

The liquefied gas processing system and the method of driving the same according to the present invention can operate and maintain the high pressure pump in accordance with the waiting time of the LNG supply in the standby mode to efficiently operate the high pressure pump with high power consumption, It is effective.

In addition, the present invention keeps the devices operating in the gas mode in the stand-by mode changing from the oil mode to the gas mode continuously without stopping, thereby enabling stable and rapid supply of gas to the customer.

1 is a conceptual diagram showing a liquefied gas supply mode of a liquefied gas processing system according to an embodiment of the present invention.
2 is a conceptual diagram showing a high-pressure pump of a liquefied gas processing system according to an embodiment of the present invention.
3 is a conceptual diagram showing a standby mode of the liquefied gas processing system according to an embodiment of the present invention.
4 is a conceptual diagram showing a standby mode of the liquefied gas processing system according to an embodiment of the present invention.
5 is a flowchart of a method of driving a liquefied gas processing system according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual view showing a liquefied gas supply mode of a liquefied gas processing system according to an embodiment of the present invention; Fig. 2 is a conceptual view showing a high-pressure pump of a liquefied gas processing system according to an embodiment of the present invention; FIG. 4 is a conceptual diagram illustrating a standby mode of the liquefied gas processing system according to an embodiment of the present invention. FIG. 4 is a conceptual diagram illustrating a standby mode of the liquefied gas processing system according to an embodiment of the present invention.

1 to 4, the liquefied gas processing system 100 includes a storage tank 10, a customer 20, a boosting pump 131, a high-pressure pump 132, a heat exchanger 50, a control unit 140). In the present specification, the liquefied gas may be used to encompass both NG, which is a liquid state, for convenience, and NG, which is a supercritical state.

The liquefied gas processing system 100 causes the boosting pump 131 to pressurize the liquefied gas discharged from the storage tank through the fuel supply line 21 to several to several tens of bar, (For example, 200 bar to 400 bar) required to supply the liquefied gas to the heat exchanger 50. Thereafter, the heat exchanger 50 may increase the temperature of the liquefied gas supplied from the pump 30, and then supply the liquefied gas in the supercritical state to the customer 20. At this time, the liquefied gas supplied to the customer 20 has a pressure of 200 bar to 400 bar and may be in a supercritical state having a temperature of 30 to 60 degrees.

1, a fuel supply line 21 for transferring liquefied gas may be provided between the storage tank 10 and the customer 20, and the boosting pump 131, The high pressure pump 132 and the heat exchanger 50 are provided to supply the liquefied gas to the customer 20.

At this time, a fuel supply valve (not shown) is provided in the fuel supply line 21, the supply amount of the liquefied gas can be adjusted in accordance with the opening degree control of the fuel supply valve, The liquefied gas adjusted to the temperature and pressure conditions required by the customer 20 can be supplied from the storage tank 10 to the customer 20 so that the customer 20 can be driven.

Specifically, the storage tank 10 stores the liquefied gas to be supplied to the customer 20. The storage tank 10 must store the liquefied gas in a liquid state, wherein the storage tank 10 may have the form of a pressure tank. The storage tank 10 may be formed of a stainless steel material having a dual tank structure, and an insulating portion (which may be in a vacuum state) is provided between the double tank structures and a pressure of 5 bar to 10 bar . ≪ / RTI >

The customer 20 is driven through the liquefied gas supplied from the storage tank 10 to generate thrust. At this time, the customer 20 may be a MEGI engine as an engine, or a dual fuel engine.

When the engine 20 is a dual fuel engine, LNG and oil may be selectively supplied without being mixed with the LNG. This is to prevent the mixture of two materials having different combustion temperatures from being mixed and to prevent the efficiency of the engine 20 from being lowered.

As the piston 20 (not shown) in the engine cylinder (not shown) reciprocates by the combustion of the LNG, the engine 20 rotates the crankshaft (not shown) connected to the piston and is connected to the crankshaft A shaft (not shown) can be rotated. Therefore, as the propeller (not shown) connected to the shaft finally rotates when the engine 20 is driven, the hull is moved forward or backward.

In the present embodiment, the engine 20 may be an engine 20 for driving the propeller, but it is not particularly limited such as an engine 20 for generating electricity or an engine 20 for generating other power .

The boosting pump 131 may be provided on the fuel supply line 21 between the storage tank 10 and the high pressure pump 132 so that a sufficient amount of liquefied gas is supplied to the high pressure pump 132, 132 from being cavitated. Also, the boosting pump 131 can pressurize the liquefied gas from the storage tank 10 to several to several tens of bars, and the liquefied gas through the boosting pump 131 can be pressurized to 1 to 25 bar.

The liquefied gas stored in the storage tank 10 is in a liquid state. At this time, the boosting pump 131 may pressurize the liquefied gas discharged from the storage tank 10 to slightly increase the pressure and the temperature, and the liquefied gas pressurized by the boosting pump 131 may still be in a liquid state.

The liquefied gas processing system 100 of the present embodiment can use oil (for example, diesel) as a fuel although not shown in the drawing, and can be used by converting fuel from liquefied gas to diesel with diesel and liquefied gas . Here, the fuel can be switched from diesel to liquefied gas, or to a stand-by mode after stopping and restarting, which will be described in the driving method.

The high-pressure pump 132 pressurizes the liquefied gas discharged from the boosting pump 131 to a high pressure so that the liquefied gas is supplied to the engine 20. The liquefied gas is discharged from the storage tank 10 at a pressure of about 1 bar to about 10 bar and then primarily pressurized by a boosting pump 131. The high pressure pump 132 is driven by a booster pump 131 The liquefied gas is secondarily pressurized and supplied to the heat exchanger 50 to be described later or supplied to the first recovery line 135 or the second recovery line 235.

At this time, the high-pressure pump 132 pressurizes the liquefied gas to a pressure required by the customer 20 (for example, 200 to 400 bar) and supplies the liquefied gas to the customer 20 so that the customer 20 produces thrust through the liquefied gas can do.

2, the high-pressure pump 132 includes a cylinder 1321 and a piston 1322 reciprocating within the cylinder 1321 and a motor 1323 driving the piston 1322. The piston 1322 reciprocates in the cylinder 1321, ≪ / RTI > In addition, the high-pressure pump 132 further includes a sealing member 1324 provided on the circumferential surface of the piston 1322, so that leakage of the liquefied gas flowing into and out of the cylinder 1321 can be prevented.

When the customer 20 is driven by oil (diesel), the high-pressure pump 132 stops operating, and the liquefied gas in the high-pressure pump 132 is continuously brought into contact with the room temperature, so that the sealing member 1324 also has a temperature Can be increased.

Unlike the driving of the booster pump 131, for example, when the standby mode is started, when the cryogenic liquefied gas flows into the high-pressure pump 132 for cooldown when the driving of the high-pressure pump 132 is stopped, 132 may be cooled. At this time, there is a fear that the sealing member 1324 is damaged by the cold heat.

In order to prevent this, the high-pressure pump 132 further includes a heat source member, and the heat source member can transmit heat when driving of the piston 1322 is waiting to prevent breakage of the sealing member 1324. [ On the other hand, when the piston 1322 is driven, frictional heat is generated by the inner wall of the cylinder 1321, so heat does not need to be transmitted separately, and the heat source member can stop driving.

This heat source member may be made of a heating coil 1325 and a heating coil 1325 is arranged to surround one end face of the sealing member 1324 and a heating coil 1325 is contacted with the sealing member 1324 to heat It is possible to prevent breakage due to cold heat.

Alternatively, the heat source member can supply N2 gas or heat generated from a heat source (e.g., an engine) generated within the liquefied gas processing system 100 to the sealing member 1324.

The booster pump 131 and the high pressure pump 132 may be controlled by the control unit 140 described below in the standby mode and may be controlled by the first recovery line 135 and the second recovery line 235 in the standby mode, The liquefied gas can be recovered to the storage tank 10 through the gas-liquid separator.

3, the first recovery line 135 is connected between the storage tank 10 and the high-pressure pump 132 to store the liquefied gas upstream of the storage tank 10 And is returned to the tank (10). The first recovery line 135 is connected to the inside of the high pressure pump 132 to recover the liquefied gas to the storage tank 10 in the standby mode before the liquefied gas is discharged to the outlet of the high pressure pump 132. The first recovery line 135 can be made to cool down by the liquefied gas in the standby mode in the process of being recovered to the storage tank 10 by the liquefied gas via the high pressure pump 132 have.

In this embodiment, when the liquefied gas is recovered through the first recovery line 135, the high-pressure pump 132 may be in an operation standby state. At this time, the high- The liquefied gas discharged from the high pressure pump 131 can be recovered from the interior of the high pressure pump 132 to the storage tank 10 via the high pressure pump 132.

The first valve 136 is installed on the first recovery line 135. The first valve 136 may be a general valve and the boosting pump 131 and the high pressure pump 132 may be cooldowned The first recovery line 135 is opened to allow the LNG in the high-pressure pump 132 to flow into the storage tank 10.

4, the second recovery line 235 is branched on the fuel supply line 21 downstream of the high-pressure pump 132 and is connected to the storage tank 10 (see FIG. 4) So that the liquefied gas discharged from the high-pressure pump 132 can be recovered to the storage tank 10. The second recovery line 235 can recover liquefied gas, which is pressurized and discharged by the high-pressure pump 132, to the storage tank 10.

Here, the second valve 236 may be provided on the fuel supply line 21 where the second recovery line 235 or the second recovery line 235 is branched, and the second valve 236 may be a general valve or a three- Valve. The second valve 236 closes the downstream of the fuel supply line 21 and opens the second recovery line 235 so that the liquefied gas discharged from the outlet of the high- (10).

The first recovery line 135 and the second recovery line 235 are separately connected to the storage tank 10 in the present embodiment. However, the second recovery line 235 may be connected to the first recovery line 135 The embodiments may be otherwise implemented as merged.

The control unit 40 can selectively open the first recovery line 135 and the second recovery line 235. [ This is for controlling the operation of the booster pump 131 or the high-pressure pump 132 and adjusting the recovery of the liquefied gas according to the standby mode time when the standby mode is executed.

For example, when the standby mode holding time is less than a preset time (for example, 30 minutes), the control unit 140 drives both the boosting pump 131 and the high-pressure pump 132 and the second recovery line 235 And the liquefied gas is recovered to the storage tank (10). Further, when the standby mode time is longer than the preset time (for example, 30 minutes), the boosting pump 131 can be kept driven, but the operation of the high-pressure pump 132 can be put on standby. This is to minimize the power consumption by waiting for the operation of the high-pressure pump 132, which consumes a large amount of power, when the standby mode is executed for more than the preset time.

At this time, when the standby mode time is less than the predetermined time (for example, 30 minutes), the control unit 140 opens the second recovery line 235 so that the liquefied gas is discharged from the high pressure pump 132 after being pressurized . In contrast, when the standby mode time is set to a predetermined time (for example, 30 minutes) or more, the high-pressure pump 132 is in an operation standby state, and therefore does not need to be discharged from the outlet of the high- The liquefied gas can be recovered to the storage tank 10 by opening the valve 135.

The control unit 140 may be divided into a case where the predetermined time is set to be less than a predetermined time and a case where the standby mode is designated to be longer than the predetermined time.

First, when the standby mode is designated (held) below the preset time, for example, when the standby mode is designated to be less than 30 minutes (i.e., 10 minutes, 15 minutes, 20 minutes, or 25 minutes).

The booster pump 131 and the high pressure pump 132 are all driven when the standby mode is executed for less than a preset time (for example, 30 minutes), for example, when the standby mode is maintained for 20 minutes, Side flow and the first recovery line 135 are closed but the second recovery line 235 is opened to circulate the liquefied gas so that the booster pump 131 and the high-pressure pump 132 continue to cool down At the same time, the state of the liquefied gas can continuously maintain the pressure required by the customer 20.

The booster pump 131 and the high-pressure pump 132 are operated when the standby mode is terminated after a predetermined time (for example, 30 minutes) and then terminated, for example, after the standby mode is maintained for 20 minutes, The boosting pump 131 and the high-pressure pump 132 continue to cool down, and the state of the liquefied gas is continuously maintained at the pressure demanded by the customer 20, The liquefied gas can be immediately supplied to the customer 20 when the standby mode is terminated.

Thus, the liquefied gas processing system 100 according to the embodiment of the present invention has the effect of enabling stable and rapid supply of the liquefied gas to the customer 20 and enabling rapid change of the oil mode and the liquefied gas mode .

Hereinafter, the case where the standby mode is designated (held) for a predetermined time or more, for example, 30 minutes or more is designated (i.e., 30 minutes, 35 minutes, 40 minutes, or 45 minutes).

The booster pump 131 and the high-pressure pump 132 are operated until the standby mode is set to a predetermined time (for example, 30 minutes), for example, when the standby mode is maintained for 40 minutes, So that the boiling pump 131 and the high pressure pump 132 continue to cool down by circulating the liquefied gas by opening the second recovery line 235 while closing the first recovery line 135 and the second recovery line 235. [ The high pressure pump 132 is stopped and the booster pump 131 is started after 30 minutes from the preset time, The second recovery line 235 is closed and the first recovery line 135 is opened so that the liquefied gas is circulated so that the boosting pump 131 and the high pressure pump 132 are kept in a state of being kept cool down do.

The booster pump 131 is continuously operated and the booster pump 131 and the high-pressure pump 132 are connected to each other by the high-pressure pump 132. In this case, the operation of the high-pressure pump 132 consuming high power can be avoided, So that the immediate operation of the high-pressure pump 132 can be performed at any time.

As a result, in the embodiment of the present invention, it is not necessary to newly perform additional cooldown, and the fuel supply to the customer 20 is immediately possible, and the driving flexibility of the oil mode and the liquefied gas mode is maximized.

The heat exchanger 50 is provided on the fuel supply line 21 between the high pressure pump 132 and the demander 20 and supplies the liquefied gas to the customer 20 when the customer 20 is driven after the standby mode is completed, It is possible to heat the liquefied gas discharged from the evaporator 132 by a method such as steam.

The liquefied gas can be supplied to the heat exchanger 50 by the high pressure pump 132. The heat exchanger 50 heats the liquefied gas while maintaining the pressure of 200 bar to 400 bar which is discharged from the high pressure pump 132, To a supercritical state of 60 degrees to 60 degrees and then supplied to the engine 20.

Such an embodiment can prevent damage to the sealing member 1324 due to cold heat by transmitting heat to the sealing member 1324 when the high pressure pump 132 is in standby in the standby mode, The high-pressure pump 132 can be driven or operated to efficiently operate the high-pressure pump 132 having a large power consumption, thereby reducing power consumption.

Hereinafter, a method of driving the liquefied gas processing system through the liquefied gas processing system 100 as described above will be described. A duplicate description of the same function and operation according to the configuration of the above-described embodiment will be omitted.

5 is a flowchart of a method of driving a liquefied gas processing system according to an embodiment of the present invention.

5, a method for driving a liquefied gas processing system according to an embodiment of the present invention is a method for driving liquefied gas stored in a storage tank 10 through a booster pump 131 or a high-pressure pump 132, (S110); Performing the standby mode (S120) to wait for supply of the liquefied gas to the customer 20; A step S130 of recovering the liquefied gas introduced into the high-pressure pump 132 to the storage tank 10; (S140), when the standby mode holding time is longer than the predetermined time, waiting for the high pressure pump 132 to operate when the standby mode time exceeds the preset time; (S151) of resuming supply of the liquefied gas to the demander (20) by restarting the high-pressure pump (132) when the standby mode is terminated, and when the standby mode holding time is less than the preset time, (S152) of resuming the supply of the liquefied gas to the demander (20).

The present embodiment is for reducing the power consumption due to the high-pressure pump 132, which consumes a lot of power when the standby mode progresses for a predetermined time or more. For example, the standby mode is set to 2 hours or less for convenience of understanding and explanation do. The controller 140 determines whether the booster pump 131 and the high pressure pump 132 are driven and whether the first and second recovery lines 135 and 235 are open according to the cooldown time. Is similar or similar to the processing system 100.

In step S110, the liquefied gas stored in the storage tank 10 is supplied to the consumer 20 through the boosting pump 131 or the high-pressure pump 132. The contents of supplying the liquefied gas stored in the storage tank 10 to the customer 20 are changed as described above.

In step S120, the standby mode for waiting for supply of the liquefied gas to the customer 20 is performed.

When the supply of the liquefied gas to the consumer 20 is stopped in step S100, for example, when the oil is supplied to the consumer 20, the supply of the liquefied gas is stopped. When the flow of liquefied gas is stopped and then flows again as in the case where the operation of the liquefied gas processing system 100 is stopped and restarted, when the liquefied gas that has continuously contacted with the room temperature and is thermally infiltrated flows into the customer 20, 20), the operation can not be performed in a stable manner. Therefore, there is a possibility that the efficiency of the operation is lowered, and the standby mode in which the supply of the liquefied gas is stopped is operated.

In the embodiment of the present invention, the booster pump 131 and the high-pressure pump 132 are continuously driven without stopping in the standby mode.

The shutting off of the liquefied gas supplied to the customer 20 can be accomplished by shutting off the second valve 236 connected to the downstream of the high pressure pump 132 or the fuel supply line 21 connected to the downstream of the high pressure pump 132 , Which can be selectively made by the standby mode time.

The standby mode hold time may be limited to, for example, a total of two hours or less, wherein the standby mode hold time is initially set to a first standby mode (preferably within a range of 30 minutes or less from the start of the standby mode) Standby mode, preferably, standby mode 30 minutes to 2 hours or less).

The initial and latter phases correspond to the steps S130 and S140, respectively, which will be described later.

In step S130, the liquefied gas flowing into the high-pressure pump 132 is recovered to the storage tank 10. This step S130 may be an initial stage of the standby mode.

The boiling pump 131 and the high-pressure pump 132 are cooled down at the beginning of the standby mode and the liquefied gas is supplied to the customer 20 as shown in Fig. 4 (the solid line shows the circulation of the liquefied gas) The temperature and pressure conditions required by the customer 20 can be obtained. The second recovery line 235 is opened through the second valve 236 and the fuel supply line 231 is opened to the side of the customer 20 via the second valve 236. In this case, 21 may be closed to control the flow of liquefied gas. Here, the second recovery line 235 is connected downstream of the high-pressure pump 132 to recover the liquefied gas pressurized by the high-pressure pump 132 to the storage tank 10.

Unlike the standby mode holding time (2 hours) described in this embodiment, even if the standby mode is abruptly stopped at this initial stage and the liquefied gas is to be supplied to the customer 20, the liquefied gas is supplied to the booster pump 131 and The liquefied gas can be immediately supplied to the customer 20 because the pressure and the conditions required by the customer 20 are always satisfied by the high-pressure pump 132, so that quick response is possible.

In this case, step S152 is performed when the standby mode holding time is less than the preset time (for example, 30 minutes).

Step S152 resumes the supply of the liquefied gas to the customer when the standby mode is ended when the standby mode holding time is less than the preset time.

At this time, the first recovery line 135 and the second recovery line 245 are blocked by the first valve 136 and the second valve 236 to stop the circulation of the liquefied gas, The liquefied gas in which the flow of the liquefied gas is opened and the heat exchanged in the heat exchanger 50 can be supplied to the customer 20. In this case, since the liquefied gas satisfies the pressure and conditions required by the consumer 20 by the boosting pump 131 and the high-pressure pump 132 at all times, the liquefied gas can be immediately supplied to the consumer 20, This is possible.

In step S140, when the standby mode holding time is equal to or longer than the preset time, the stand-by mode time waits for the operation of the high-pressure pump 132 when the predetermined time or more elapses. In this step S140, the standby mode is the last stage of the standby mode, and the standby mode may be a stage where more than 30 minutes have elapsed. At this time, the boosting pump 131 is still in a running state and the high-pressure pump 132 is in a standby state so that the liquefied gas circulates through the storage tank, the boosting pump 131 and the high-pressure pump 132. Accordingly, power consumption can be minimized by waiting for the high-pressure pump 132, which has a large power consumption, in comparison with the boosting pump 131.

On the other hand, as shown in Fig. 3 (the solid line indicates the circulation of the liquefied gas), in the latter stage of the standby mode, when the high pressure pump 132 is switched to the standby state, It does not need to be discharged through. Accordingly, when the standby mode becomes longer than the predetermined time, the outlet of the high-pressure pump 132 is shut off to block the supply of the liquefied gas to the customer 20, and the liquefied gas flowing through the boosting pump 131 is supplied to the high- And may be circulated through the first recovery line 135 before the outlet of the pump 132. [ At this time, the second recovery line 235 and the fuel supply line 21 may be closed.

That is, in this case, the liquefied gas is circulated by the boosting pump 131 by the storage tank 10, the boosting pump 131, the high-pressure pump 132 by the fuel supply line 21 and the first recovery line 135 And the high-pressure pump 132 can minimize power consumption in a state in which the high-pressure pump 132 is in operation.

In step S151, when the standby mode is terminated, the high-pressure pump 132 is restarted to resume the supply of the liquefied gas to the customer 20. When the standby mode is terminated, that is, when the latter state of the standby mode is ended (after 2 hours elapses), supply of the liquefied gas to the consumer 20 is resumed.

At this time, the first recovery line 135 and the second recovery line 245 are blocked by the first valve 136 and the second valve 236 to stop the circulation of the liquefied gas, The liquefied gas in which the flow of the liquefied gas is opened and the heat exchanged in the heat exchanger 50 can be supplied to the customer 20.

As described above, in the present embodiment, for example, when the fuel is switched from oil to liquefied gas, the standby mode is activated to cool down the boosting pump 131 and the high-pressure pump 132, ) And the standby state can be controlled to reduce the waste of electric power, and stable operation can be achieved, thereby improving the efficiency of the operation.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the same is by way of illustration and example only and is not to be construed as limiting the present invention. It is obvious that the modification and the modification are possible.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

10: Storage tank 20: Consumer
21: fuel supply line 50: heat exchanger
100: Liquefied gas processing system 131: Boosting pump
132: high-pressure pump 135: first recovery line
136: first valve 140:
235: Second recovery line 236: Second valve
1321: cylinder 1322: piston
1324: sealing member 1325: heating coil

Claims (15)

A boosting pump for supplying liquefied gas stored in the storage tank;
A high pressure pump for pressurizing the liquefied gas supplied from the boosting pump;
A first recovery line connected to the storage tank from inside the high-pressure pump to recover the liquefied gas;
A second recovery line for recovering the liquefied gas from the downstream of the high-pressure pump to the storage tank; And
And a control unit for causing the high-pressure pump to stand by when the standby mode continues for a predetermined time or more,
Wherein,
When the standby mode is started, both the boosting pump and the high-pressure pump are operated to recover the liquefied gas to the storage tank through the second recovery line,
Pressure pump, and when the standby mode is exceeded for a preset time, the high-pressure pump is operated standby and the liquefied gas is recovered to the storage tank through the first recovery line. delete The method according to claim 1,
Further comprising a fuel supply line connected from the storage tank to a customer,
Wherein the second recovery line is connected from the downstream of the high-pressure pump to the storage tank on the fuel supply line. The method of claim 3,
Wherein the first recovery line comprises a first valve for performing opening or closing; And
Further comprising a second valve formed at a point where the second recovery line and the fuel supply line are connected to form a three-way valve. 5. The apparatus of claim 4,
When the standby mode is started, the fuel supply line between the high-pressure pump and the demander is closed via the second valve, the second recovery line is opened,
Closing the fuel supply line between the second recovery line and the high-pressure pump and the customer via the second valve, and opening the first recovery line when the standby mode exceeds the preset time. Gas treatment system. The apparatus of claim 1,
And the liquefied gas is recovered by opening the first recovery line according to the standby mode time or opening the second recovery line. The apparatus of claim 1,
Wherein when the standby mode is less than the predetermined time from the start of the standby mode time, the downstream of the high pressure pump is shut off, and the second recovery line is opened to recover the liquefied gas. The apparatus of claim 1,
Wherein the outlet of the high-pressure pump is shut off and the first recovery line is opened to recover the liquefied gas when the standby mode is equal to or longer than the predetermined time. A first recovery line for supplying the liquefied gas stored in the storage tank to a customer through a boosting pump or a high pressure pump, the first recovery line connecting the inside of the high pressure pump and the storage tank, and the second recovery line for connecting the storage tank, In a liquefied gas processing system having a recovery line,
Supplying the liquefied gas stored in the storage tank to the customer through the boosting pump or the high-pressure pump;
Performing a standby mode to wait for supply of the liquefied gas to the customer;
Operating both the boosting pump and the high-pressure pump to recover the liquefied gas to the storage tank through the second recovery line when the standby mode is started; And
Characterized by comprising the step of waiting for the high pressure pump to be actuated and recovering the liquefied gas to the storage tank through the first recovery line when the standby mode is exceeding the preset time . 10. The method of claim 9,
Further comprising the step of restarting the high-pressure pump to resume the supply of the liquefied gas to the customer when the standby mode is terminated. The method as claimed in claim 9, wherein, when recovering the liquefied gas introduced into the high-pressure pump to the storage tank,
And the liquefied gas is recovered to the storage tank by shutting off the downstream of the high-pressure pump. delete 10. The method of claim 9,
Wherein the step of waiting for the high pressure pump to operate and recovering the liquefied gas to the storage tank through the first recovery line,
Wherein the operation of the boosting pump is maintained and the operation of the high-pressure pump is awaited. 14. The method of claim 13,
Wherein the step of waiting for the high pressure pump to operate and recovering the liquefied gas to the storage tank through the first recovery line,
And the liquefied gas flowing into the high-pressure pump through the booster pump is recovered to the storage tank. 10. The method of claim 9,
Further comprising the step of resuming supply of the liquefied gas to the customer when the standby mode is terminated when the standby mode holding time is less than the preset time.

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