WO2019050003A1

WO2019050003A1 - Ship

Info

Publication number: WO2019050003A1
Application number: PCT/JP2018/033257
Authority: WO
Inventors: 拓海野崎; 俊宏 ▲高▼木; 宏之武田; 尚子印藤; 和也萩原; 雄輝宍粟; 崇嗣安部; 直樹成島
Original assignee: 川崎重工業株式会社
Priority date: 2017-09-08
Filing date: 2018-09-07
Publication date: 2019-03-14
Also published as: CN111033024A; JP6982439B2; SG11202001767YA; KR20200047623A; JP2019049216A

Abstract

A ship that comprises: a fuel supply line that supplies LPG from a fuel tank to an engine; a pump and a shutoff valve that are provided to the fuel supply line; a fuel recovery line that recovers LPG from the engine to the fuel tank; a bypass line that branches from the fuel supply line upstream of the shutoff valve and is connected to the fuel recovery line or the fuel tank; a flow rate control valve that is provided to the bypass line; a manometer that detects the supply pressure of the LPG upstream of the shutoff valve; a flowmeter that detects the supply flow rate or the recovery flow rate of the LPG; and a control device. When the shutoff valve is closed, the control device controls the flow rate control valve and/or the rotational speed of the pump such that the supply pressure of the LPG as detected by the manometer stays at a required pressure that is necessary for the engine to operate. When the shutoff valve is open, the control device controls the flow rate control valve and the rotational speed of the pump such that the flow rate detected by the flowmeter is at a prescribed value that corresponds to the fuel consumption of the engine.

Description

Ship

The present invention relates to a ship including a propulsion engine fueled by LPG.

In conventional vessels, the fuel for the propulsion engine is generally a fuel oil such as heavy oil or light oil, or LNG (Liquefied Natural Gas). In recent years, it has also been proposed to use LPG (Liquefied Petroleum Gas) as fuel for a propulsion engine.

For example, the ship disclosed in Patent Document 1 includes a light oil storage tank for storing light oil and a deck tank for storing LPG, so that the diesel fuel or LPG can be selectively supplied to the propulsion engine as fuel. ing. The deck tank is connected to the engine through a fuel transfer pipe, and a pump and a shutoff valve are installed in the fuel transfer pipe.

During the use of light oil, the pump is shut off and the shutoff valve is closed. When switching the fuel from light oil to LPG, the pump operates to open the shutoff valve, thereby starting the supply of LPG to the engine.

Korean Published Patent No. 2012-0113398

In order to inject fuel in the engine, it is necessary to secure the fuel supply pressure to the engine at a certain value or more. As described above, when operating the pump at the stage of starting the LPG supply, the pressure of the LPG in the fuel transfer pipe may not meet the pressure required by the engine, and the engine may not be able to operate smoothly. In addition, the problem at the time of the supply start of this LPG may arise similarly not only in the binary fuel engine disclosed by patent document 1, but the engine which uses only LPG as fuel.

Then, an object of this invention is to provide the ship which can operate a propulsion engine smoothly at the time of supply start of LPG.

A ship according to an aspect of the present invention is provided in a fuel tank storing LPG, a propulsion engine using LPG as fuel, a fuel supply line for supplying LPG from the fuel tank to the engine, and the fuel supply line Pump, a shut-off valve provided on the fuel supply line downstream of the pump, a fuel recovery line for collecting unused LPG from the engine to the fuel tank, and between the pump and the shut-off valve The fuel supply line and a bypass line connected to the fuel recovery line or the fuel tank, a flow control valve provided on the bypass line, the fuel downstream of the pump and upstream of the shutoff valve A pressure gauge provided in a supply line for detecting the pressure of LPG supplied from the pump, and to the engine through the fuel line A flow meter for detecting the supply flow rate of LPG entering or the recovery flow rate of LPG flowing out from the engine through the fuel recovery line, and a control device for controlling the number of rotations of the pump and the flow control valve When closing the valve and stopping the supply of LPG to the engine, the control device maintains the pressure of the LPG detected by the pressure gauge at the required pressure necessary for the operation of the engine. When controlling the number of revolutions of the pump and / or the flow control valve and opening the shutoff valve to supply LPG to the engine, the control device controls the flow rate detected by the flow meter in the engine The number of revolutions of the pump and the flow rate control valve are controlled to be a predetermined value corresponding to the amount of fuel consumption.

According to the above configuration, the pump rotational speed and the flow rate control valve are controlled so that the bypass line is provided and the flow rate of LPG is adjusted according to the fuel consumption, so that excessive supply of LPG to the engine can be suppressed. In a vessel equipped with a recovery line, it is possible to suppress an excessive rise in the temperature of LPG in the fuel tank.

In addition, during the supply of LPG, the pump and flow control valve used for flow control are used to adjust the pressure of the LPG in the fuel supply line when the supply of the LPG whose shutoff valve is closed is stopped. As described above, the pump rotational speed and the flow control valve are used in combination with the pressure control to maintain the LPG supply pressure at the required pressure necessary for the operation of the engine, so that the engine can be operated smoothly at the start of the LPG supply.

The control device is provided with a pressure control valve provided in the fuel recovery line upstream of a merging point of the bypass line, and the control device controls the pressure control when opening the shutoff valve and supplying LPG to the engine. A valve may be operated to control the pressure of the LPG supplied to the engine. According to the above configuration, it is possible to realize the pressure control of the LPG supplied to the engine while using the flow control valve and the pump rotational speed for the flow control when supplying the LPG.

According to the present invention, it is possible to provide a ship capable of smoothly operating the propulsion engine at the start of LPG supply.

It is a schematic block diagram of the ship concerning an embodiment. It is a schematic block diagram of the ship concerning a modification.

Hereinafter, embodiments will be described with reference to the drawings. The same or corresponding elements will be denoted by the same reference symbols throughout the drawings, without redundant description.

The ship 1 shown in FIG. 1 is an LPG fuel propelled ship. The ship 1 includes a fuel tank 2 storing LPG, and a propulsion engine 11 fueled by the LPG. The main component of LPG may be propane (propane gas) or butane (butane gas).

In the present embodiment, the fuel tank 2 is configured of a storage tank 21 having a relatively large volume and a service tank 22 having a relatively small volume. The storage tank 21 and the service tank 22 are both pressure vessels whose pressure resistance is higher than atmospheric pressure. The storage tank 21 and the service tank 22 are connected to each other by a relay line 26.

The LPG is introduced into the storage tank 21 from the LPG supply source through the fuel introduction line 23. The LPG supply source may be a cargo tank mounted on the ship 1, or may be an LPG supply facility on land or an LPG fuel supply ship.

In the present embodiment, the storage tank 21 is not provided with means (for example, a heat insulating material) for maintaining the LPG at a low temperature, and the temperature of the LPG in the storage tank 21 changes following the atmospheric temperature. LPG introduced from an LPG source is often at about -42 ° C. when the main component is propane gas. Therefore, the fuel introduction line 23 is provided with a heater 24 for heating the LPG to a temperature in the range of, for example, −5 ° C. to the ambient temperature. However, if the LPG supply facility on the land that is the LPG supply source and the LPG fuel supply ship are equipped with a heater, and the temperature of the LPG delivered to the ship 1 is -5 ° C or higher, the heater 24 is unnecessary. is there.

In the case of only PG in which the component of the air layer in the storage tank 21 is vaporized, the pressure of the air layer in the storage tank 21 is the saturated vapor pressure of LPG. For example, when the temperature in the storage tank 21 is 25 ° C., the pressure (saturated vapor pressure) of the air layer in the storage tank 21 is about 0.9 MPa in gauge pressure. Hereinafter, all indications of pressure are gauge pressures. In addition, since the saturated vapor pressure of LPG is about 1.7 MPa at 50 ° C., the storage tank 21 is configured to withstand, for example, 1.8 MPa. For reference, the saturated vapor pressure of LPG is about 0.4 MPa at 0 ° C.

A pump 25 is installed inside the storage tank 21. The number of pumps 25 may be one or more. The upstream end of the relay line 26 is connected to the pump 25. The downstream end of the relay line 26 opens in the service tank 22. The LPG is supplied from the storage tank 21 to the service tank 22 through the relay line 26 by the pump 25. However, the pump 25 may be provided in the middle of the relay line 26 outside the storage tank 21.

Similar to the storage tank 21, the service tank 22 is not provided with means for maintaining the LPG at a low temperature, and the temperature of the LPG in the service tank 22 changes following the atmospheric temperature. When the component of the air layer in the service tank 22 is only vaporized PG, the pressure of the air layer in the service tank 22 is the saturated vapor pressure of LPG.

During circulation of LPG between the engine 11 and the service tank 22 as described later, the temperature of the LPG in the service tank 22 may be higher than the ambient temperature. For example, when the temperature of LPG in the service tank 22 is 60 ° C., the pressure (saturated vapor pressure) of the gas layer in the service tank 22 is about 2.1 MPa. The service tank 22 is configured to withstand, for example, 2.2 MPa.

The service tank 22 is connected to the propulsion engine 11 by a fuel supply line 31 and a fuel recovery line 41. LPG is supplied from the service tank 22 to the engine 11 through the fuel supply line 31, and unused LPG is recovered from the engine 11 to the service tank 22 through the fuel recovery line 41. In other words, LPG circulates between the service tank 22 and the engine 11 through the fuel supply line 31 and the fuel recovery line 41.

The upstream end of the fuel supply line 31 is connected to the lower part of the service tank 22. The downstream end of the fuel recovery line 41 opens in the service tank 22.

The engine 11 is, for example, a diesel cycle or Otto cycle reciprocating engine. Although not shown, the engine 11 includes a main flow path connecting the downstream end of the fuel supply line 31 and the upstream end of the fuel recovery line 41, and a plurality of fuel injection valves connected in parallel to the main flow path.

The fuel supply line 31 is provided with a pump 32, a heater 33 and a shutoff valve 34 in this order from the upstream side.

The relay line 26 is provided with a heater 27 for heating the LPG supplied from the storage tank 21 to the service tank 22. The heater 33 heats the LPG to the required temperature (for example, 45 ° C.) of the engine 11. When LPG is supplied to the engine 11, an amount of LPG corresponding to the fuel consumption amount Qe of the engine 11 is supplied from the storage tank 21 to the service tank 22. The heater 27 is used when it is difficult to heat the engine 11 to the required temperature by the heater 33 alone. The heater 27 may be omitted.

In the fuel recovery line 41, a first pressure control valve 42, a shutoff valve 43, a cooler 44 and a second pressure control valve 45 are provided in this order from the upstream side. The cooler 44 cools the LPG to a predetermined temperature (for example, 40 ° C.). The cooler 44 may be omitted.

The fuel supply line 31 and the fuel recovery line 41 are connected by a first bypass line 51. The first bypass line 51 branches from the fuel supply line 31 between the pump 32 and the shutoff valve 34, more specifically, between the heater 33 and the shutoff valve 34, and fuel recovery between the shutoff valve 43 and the cooler 44. It is connected to the line 41. A flow control valve 52 is provided in the first bypass line 51.

Furthermore, in the present embodiment, the second bypass line 53 is also adopted. The second bypass line 53 branches from the fuel supply line 31 between the pump 32 and the heater 33 and is connected to the service tank 22. The second bypass line 53 is provided with a flow control valve 54. However, either one of the first bypass line 51 and the second bypass line 53 may be omitted.

The pump 32, the

shutoff valves

34 and 43, the

pressure control valves

42 and 45, and the

flow control valves

52 and 54 are controlled by the controller 6. However, in FIG. 1, only some signal lines are drawn for simplification of the drawing. The control device 6 is, for example, a computer having a memory such as a ROM or a RAM and a CPU, and a program stored in the ROM is executed by the CPU. The control device 6 may be a single device or may be divided into a plurality of devices (for example, an engine control device and a fuel supply control device).

The controller 6 is electrically connected to the first supply pressure gauge 72, the second supply pressure gauge 73, the recovery pressure gauge 74, and the flow meter 81. The flow meter 81 is used to control the pump 32 and the flow control valve 52, particularly, to control the LPG flow when supplying LPG to the engine 11. The first supply pressure gauge 72 is used for control of the pump 32 and the flow control valve 52, particularly for LPG pressure control when the supply of the LPG to the engine 11 is stopped. The second supply pressure gauge 73 is used to control the first pressure control valve 42, and the recovery pressure gauge 74 is used to control the second pressure control valve 45.

A flowmeter 81 is provided in the fuel supply line 31 downstream of a branch point with the first bypass line 51, and detects a supply flow rate Qi of the LPG flowing into the engine 11 through the fuel supply line 31.

The first supply pressure gauge 72 is provided on the fuel supply line 31 downstream of the pump 32 (more specifically, downstream of the heater 33). The first supply pressure gauge 72 detects the pressure of the LPG supplied from the pump 32. The second supply pressure gauge 73 is provided on the fuel supply line 31 downstream of the shutoff valve 34 and detects the pressure of the LPG supplied to the engine 11 through the shutoff valve 34.

The recovery pressure gauge 74 is provided in the fuel recovery line 41 between the shutoff valve 43 and the second pressure regulating valve 45. The recovery pressure gauge 74 detects the pressure of the LPG after the pressure is reduced by the first pressure control valve 42. In the present embodiment, the recovery pressure gauge 74 is located upstream of the cooler 44, but may be located downstream of the cooler 44.

Here, the engine 11 may be an engine using only LPG as a fuel, or may be a dual fuel engine using LPG and a fuel oil such as heavy oil or light oil as fuel. In the case of an engine using only LPG as fuel, the timing at which the supply of LPG to the engine 11 starts corresponds to the timing at which the operation of the engine 11 starts. The period in which the supply of LPG to the engine 11 is stopped corresponds to the period in which the engine 11 is stopped. In the case of a dual fuel engine, the timing to start supplying the LPG to the engine 11 is the timing to start the operation of the engine 11 and the engine 11 is in operation but the fuel supplied to the engine 11 is changed from fuel oil to LPG The timing of switching is included. The period in which the supply of LPG to the engine 11 is stopped includes the period in which the engine 11 is stopped and the period in which the engine 11 is operated using fuel oil as fuel.

The control device 6 closes the

shutoff valves

34 and 43 while the

shutoff valves

34 and 43 are not supplying the LPG to the engine 11. While LPG is being supplied to the engine 11, the controller 6 opens the

shutoff valves

34 and 43. While the engine 11 is stopped, the flow passage between the shutoff valves 34 and 43 (the downstream portion of the fuel supply line 31, the main flow passage of the engine 11 and the upstream portion of the fuel recovery line 41) is purged with an inert gas.

When LPG is supplied to the engine 11, LPG pressure control, flow control and temperature management are performed.

With regard to the flow control of LPG at the time of engine supply of LPG, the control device 6 controls the rotation of the pump 32 so that the supply flow rate Qi detected by the flowmeter 81 becomes a predetermined value V according to the fuel consumption Qe of the engine 11. Control the number. In the present embodiment, the predetermined value V is a value obtained by multiplying the fuel consumption amount Qe of the engine 11 by the coefficient C (V = Qe × C). For example, the coefficient C is usually 1.1 to 1.50. The coefficient C may be a fixed value set within this numerical range, or may be variably set within this numerical range.

For example, the control device 6 may determine the fuel consumption amount Qe of the engine 11 based on the operation amount of the telegraph lever operated by the operator. Alternatively, when the control device 6 is divided into an engine control device that controls the engine 11 and a fuel supply control device that controls the pump 32 and various valves, the fuel calculated by the engine control device is the fuel supply control device. The fuel consumption Qe of the engine 11 may be determined based on the value related to the consumption.

As a result of the rotational speed control of the pump 32 based on the supply flow rate Qi detected by the flow meter 81, when the rotational speed of the pump 32 becomes the minimum rotational speed, the control device 6 detects the supply flow rate Qi detected by the flow meter 81. Controls either one of the

flow control valves

52 and 54 so that the predetermined value V becomes as described above. Specifically, the control device 6 increases the opening degree of either one of the

flow control valves

52 and 54 as the fuel consumption amount Qe of the engine 11 decreases, and reduces the flow rate of the LPG supplied to the engine 11.

Since the rotational speed of the pump 32 and the flow control valve 52 are controlled so that the flow rate of the LPG is adjusted according to the fuel consumption, it is possible to suppress the excessive supply of the LPG to the engine 11. The temperature of the LPG rises as the LPG passes through the engine 11 and receives heat from the engine 11. By providing the

bypass lines

51 and 53, it is possible to suppress an excessive rise in the temperature of the LPG in the fuel tank 2 (service tank 22) in the ship 1 provided with the fuel recovery line 41.

The temperature of the LPG rises a little as the LPG passes through the engine 11 (for example, 55 ° C.). Therefore, in order to prevent the LPG decompressed by the first pressure regulating valve 42 from being vaporized, the control device 6 sets the pressure detected by the recovery pressure gauge 74 to be higher than the saturated vapor pressure at the assumed maximum temperature. The second pressure regulating valve 45 is controlled to a value (for example, 2.0 MPa).

Regarding pressure control of LPG at the time of engine supply of LPG, the controller 6 sets the pressure detected by the second supply pressure gauge 73 to be the required pressure of the engine 11 (for example, 5.0 to 6.0 MPa). (1) Control the pressure control valve 42. The required pressure is the pressure required to properly inject the fuel and, in turn, to operate the engine 11 smoothly.

Also when the supply of LPG to the engine 11 is stopped, pressure control of the LPG is performed. However, this pressure control is not always performed during the LPG supply stop. In a dual fuel engine, for example, it is performed during use of light oil. At this time, in preparation for the start of supply of LPG to the engine 11, the LPG may be filled in the engine main flow path for LPG. In an engine fueled only with LPG, for example, it is executed during the standby period. In the engine using only LPG as fuel, purge with inert gas may be performed during this standby period.

With regard to pressure control of the LPG during a period in which the

shutoff valves

34 and 43 are closed and the supply of LPG is stopped, the controller 6 operates the pump 32 and opens the flow control valve 52 and / or the flow control valve 54. Let me speak. As a result, the LPG in the storage tank 21 is returned to the storage tank 21 without passing through the engine 11 via the fuel supply line 31, the first bypass line 51 and the fuel recovery line 41. And / or LPG in the storage tank 21 is returned to the storage tank 21 via the fuel supply line 31 and the second bypass line 53 without passing through the engine 11. The controller 6 controls the rotational speed of the pump 32 and the

flow control valves

52, 54 so as to maintain the supply pressure of the LPG detected by the first supply pressure gauge 72 at the required pressure (for example, 5.0 to 6.0 MPa). Control. The first supply pressure gauge 72 is provided on the fuel supply line 31 downstream of the pump 32 and upstream of the shutoff valve 34, and the branch point of the first bypass line 51 is also upstream of the shutoff valve 34. Being located on the side, the pressure of the refluxing LPG can be detected.

As one example, the rotation speed of the pump 32 is maintained at the minimum rotation speed, and the flow control valve 52 increases the opening degree when the detected pressure exceeds the required pressure, and the opening degree when the detected pressure is less than the required pressure Make

When the

shutoff valves

34 and 43 are switched from the closed state to the open state under the condition where such pressure control is being performed, the supply pressure of LPG reaches the required pressure on the upstream side of the shutoff valve 34 from the beginning of switching. ing. For this reason, thereafter, only the pressure increase on the downstream side of the shutoff valve 34 (in particular, between the shutoff valves 34 and 43) is necessary, and the pressure supplied to the engine 11 is rapidly stabilized after the

shutoff valves

34 and 43 are opened. be able to. If the pressure is stabilized, the operation can be switched to the operation using the LPG, and the operation using the LPG can be smoothly and promptly started.

The rotational speed of the pump 32 and the opening degree of the

flow control valves

52 and 54 are used for pressure control when LPG is not supplied, and are used for flow control when LPG is supplied. The control device 6 operates the first pressure control valve 42 to control the pressure supplied to the engine 11, so that the control of the supply pressure is performed while using the rotational speed of the

flow control valves

52, 54 and the pump 32 for flow control. Can be realized at the same time.

(Modification)
The present invention is not limited to the embodiments described above, and various modifications can be made without departing from the scope of the present invention.

For example, as shown in FIG. 2, a flow meter 81 may be provided on the fuel recovery line 41 upstream of the shutoff valve 43 to detect the recovery flow rate Qo of LPG flowing out of the engine 11 through the fuel recovery line 41. That is, the control device 6 may control the pump 32 and the flow control valve 52 such that the recovery flow rate Qo detected by the flow meter 81 becomes a predetermined value V 'corresponding to the fuel consumption amount Qe of the engine 11. . In this case, the predetermined value V ′ is, for example, a value obtained by multiplying the fuel consumption amount Qe of the engine 11 by a coefficient C of usually 0.1 to 0.50.

The predetermined values V and V 'do not necessarily have to be constant, and the control device 6 may increase the predetermined values V and V' when the number of rotations of the pump 32 becomes the minimum number of rotations. For example, in the configuration shown in FIG. 1, the predetermined value V may be increased to a flow rate in the range of 1.1 × Qe to 11.0 × Qe. Alternatively, in the configuration shown in FIG. 2, the predetermined value V ′ may be increased to a flow rate in the range of 0.1 × Qe to 10.0 × Qe.

The predetermined values V and V 'are constant when the rotational speed of the pump 32 reaches the minimum rotational speed, and the flow control valve 54 provided in the second bypass line 53 is opened. The surplus amount obtained by subtracting the predetermined values V and V ′ from the discharge flow rate Q is returned to the service tank 22 through the second bypass line 53. Since the surplus is heated by the pump 32, the temperature of the LPG in the service tank 22 rises. On the other hand, if the predetermined values V and V 'are increased when the rotational speed of the pump 32 reaches the minimum rotational speed, the LPG returned to the service tank 22 through the second bypass line 53 can be reduced. . On the other hand, although the LPG passing through the engine 11 is also increased by the increase of the predetermined values V and V ', the increased amount is cooled by the cooler 44 provided in the fuel recovery line 41. Therefore, the rise of the temperature of the LPG in the service tank 22 can be suppressed.

Further, as shown in FIG. 2, the second supply pressure gauge 73 may be omitted. In this case, the first pressure control valve 42 is controlled using the pressure detected by the first supply pressure gauge 72.

Moreover, in the said embodiment, although the pressure control at the time of supply stop of LPG controlled the rotation speed of the pump 32 to the fixed value of the minimum rotation speed, even if the rotation speed of the pump 32 is controlled to other fixed values. It may be set variably according to the temperature and the pressure of the air layer in the fuel tank 2.

Moreover, in the said embodiment, although the fuel tank 2 was comprised with the storage tank 21 and the service tank 22, the storage tank 21 may be abbreviate | omitted and the fuel tank 2 may be comprised only with the service tank 22. FIG. That is, LPG may be directly introduced into the service tank 22 from the LPG supply source. However, if it is a structure like the said embodiment, the fuel tank 2 can be divided into the storage tank 21 for LPG introduction, and the service tank 22 for LPG circulation.

DESCRIPTION OF SYMBOLS 1 ship 2 fuel tank 6 control device 11 engine for propulsion 31 fuel supply line 32 pump 34 shutoff valve 41 fuel recovery line 42 first pressure regulating valve 43 shutoff valve 51 first bypass line 52 flow control valve 53 second bypass line 54 flow rate Control valve 72 First supply pressure gauge 81 Flow meter Qe Fuel consumption Qi Inflow rate Qo Outflow rate

Claims

A fuel tank for storing LPG,
A propulsion engine powered by LPG,
A fuel supply line for supplying LPG from the fuel tank to the engine;
A pump provided in the fuel supply line;
A shutoff valve provided in the fuel supply line downstream of the pump;
A fuel recovery line for recovering unused LPG from the engine to the fuel tank;
A bypass line branched from the fuel supply line between the pump and the shutoff valve and connected to the fuel recovery line or the fuel tank;
A flow control valve provided in the bypass line;
A pressure gauge provided on the fuel supply line downstream of the pump and upstream of the shutoff valve for detecting the pressure of LPG supplied from the pump;
A flow meter for detecting a supply flow rate of LPG flowing into the engine through the fuel line or a recovery flow rate of LPG flowing out of the engine through the fuel recovery line;
A controller for controlling the number of rotations of the pump and the flow control valve;
When closing the shutoff valve and stopping the supply of LPG to the engine, the control device maintains the pressure of the LPG detected by the pressure gauge at the required pressure necessary for the operation of the engine. Control the number of revolutions of the pump and / or the flow control valve,
When the shutoff valve is opened and LPG is supplied to the engine, the control device causes the flow rate detected by the flow meter to be a predetermined value according to the fuel consumption of the engine. A vessel for controlling the number of revolutions and the flow control valve.
A pressure control valve provided in the fuel recovery line upstream of a junction of the bypass lines;
The control device controls the pressure of LPG supplied to the engine by operating the pressure control valve when the shutoff valve is opened to supply the LPG to the engine. Ship.