JP6023900B2 - Fuel gas supply device for gas engine - Google Patents

Description

  The present invention relates to a fuel gas supply device that supplies fuel gas to a gas engine.

  Since the fuel gas supply device for a marine gas engine constitutes a part of the ship, it must be structured in accordance with the rules (Classes & Regulations for Classification of Ships) established by the Classification Society. According to this classification rule, it is stipulated that two emergency shut-off valves are installed in the fuel gas piping provided in the fuel gas supply device. The reason why the two shutoff valves are installed in the fuel gas pipe is to reliably shut off the flow of the fuel gas in an emergency even if one of the shutoff valves fails.

  Further, according to the classification rules, it is determined that open pipes are installed between the two shutoff valves and downstream of the shutoff valve on the downstream side. The open pipe is for discharging the fuel gas remaining in the fuel gas pipe to the outside of the ship when the shutoff valve is closed. Since the two open pipes discharge fuel gas outside the ship, they can be combined into one pipe (see page 22 of Non-Patent Document 1). A structure in which two open pipes are merged to form one pipe can reduce the number of pipes extending from the fuel gas supply device to the outside of the ship. It is effective from.

Thomas Stenhede, “LNG as a Marine Fuel”, [online], December 1, 2010, [searched November 27, 2013], Internet (URL: http://www.markis.eu/fileadmin/Arkiv /Dokumenter/Konference_2010.12.01/Waertsilae_Sweden_-_Markis_2010.12.01.pdf)

  However, if a structure is formed in which two open pipes are joined, a flow path that bypasses the downstream shut-off valve is newly formed. Therefore, if the upstream shut-off valve breaks down, a situation may occur in which the flow of fuel gas cannot be shut off in an emergency. This makes it meaningless to provide two shutoff valves. Similar problems may also occur in a fuel gas supply device of a gas engine for uses other than for ships, such as for power generation.

  The present invention has been made in view of such circumstances, and is a fuel gas supply device of a gas engine for ships and other uses, which includes a pipe extending from the fuel gas supply device toward the outside of the ship or outdoors. It is an object of the present invention to provide a fuel gas supply device that can reliably cut off the flow of fuel gas toward a gas engine in an emergency even if one of the shut-off valves breaks down while reducing the number.

  A fuel gas supply apparatus according to an aspect of the present invention is a fuel gas supply apparatus that supplies fuel gas to a gas engine, and is provided in a fuel gas pipe that conveys the fuel gas to the gas engine, and the fuel gas pipe Two shut-off valves that are closed in an emergency, an upstream open pipe connected to a portion between the two shut-off valves in the fuel gas pipe, and a downstream of the shut-off valve on the downstream side in the fuel gas pipe A downstream open pipe that is connected to the part and merges with the upstream open pipe; an upstream open valve that is provided in the upstream open pipe and that is opened in the emergency; and is provided in the downstream open pipe and is opened in the emergency. A downstream open valve; and a check valve provided in the downstream open pipe and regulating a flow of the fuel gas toward the fuel gas pipe.

  If the upstream open pipe and the downstream open pipe are combined as described above, the number of pipes extending from the fuel gas supply device toward the outside of the ship or outdoors can be reduced, but the upstream shut-off valve fails. In this case, the fuel gas that has passed through the upstream open pipe in an emergency may flow back into the downstream open pipe and continue to flow into the fuel gas pipe. If such a thing happens, there is no point in installing two shutoff valves. However, according to the above gas supply device, since the check valve is provided in the downstream open pipe, the backflow of the fuel gas in the downstream open pipe is prevented, and the flow of the fuel gas toward the gas engine is ensured in an emergency. Can be blocked.

  In the above fuel gas supply device, the fuel gas pipe further includes a pressure regulating valve that adjusts the pressure of the fuel gas, and a pressure vessel that forms an outer shell of the fuel gas supply device, The valves and the pipes including the pressure regulating valve may be accommodated in the pressure vessel. According to such a configuration, it is possible to satisfy the provisions of the double gas leakage prevention structure in the classification rules while using a normal pressure regulating valve as it is. Therefore, it is easy to provide the pressure regulating valve in the fuel gas supply device, that is, to be disposed near the gas engine. If the pressure regulating valve can be provided in the vicinity of the gas engine, it is possible to control the fuel gas pressure with good responsiveness.

  The fuel gas supply apparatus may further include a gas filter provided in the fuel gas pipe and a gas flow meter provided in the fuel gas pipe, and the gas filter and the gas flow meter may include the pressure. It may be accommodated in a container. By using a pressure vessel, a gas filter and a gas flow meter can also be installed in the fuel gas supply device. Therefore, these can be arrange | positioned in the vicinity of a gas engine. Thereby, the quantity of the fuel gas which a gas engine consumes can be measured correctly, and possibility that a foreign material will penetrate | invade a gas engine can be reduced.

  Thus, according to the fuel gas supply apparatus described above, the fuel gas that goes to the gas engine in an emergency even if one of the shut-off valves breaks down while reducing the number of pipes that go from the fuel gas supply apparatus to the outside of the ship or outdoors. Can be reliably shut off.

FIG. 1 is a block diagram of a fuel gas supply apparatus according to an embodiment. FIG. 2 is a diagram showing the flow of fuel gas when there is no check valve.

<Overall structure>
First, the overall structure of the fuel gas supply device according to this embodiment will be described. FIG. 1 is a block diagram of a fuel gas supply apparatus. The fuel gas supply device 100 is a device that supplies fuel gas to a gas engine. This gas engine is an engine mounted on a ship for propulsion. However, the gas engine is not limited to a ship and may be a gas engine used for other purposes. For example, the gas engine may be a power generation gas engine installed in a factory or the like. In this case, “outboard” in the following description is “outdoor”. The fuel gas supplied to the gas engine is supplied from a fuel gas tank. A blower or a compressor (not shown) is disposed between the fuel gas tank and the fuel gas supply device 100, and pressurized fuel gas is supplied to the fuel gas supply device 100. However, when there is no need to pressurize the fuel gas, for example, the inside of the fuel gas tank is at a high pressure, no blower or compressor is arranged.

  As shown in FIG. 1, the fuel gas supply device 100 includes a pressure regulating valve 10, an upstream cutoff valve 11, a downstream cutoff valve 12, an upstream release valve 13, a downstream release valve 14, a check valve 15, And a pressure vessel 16. Of the upstream shut-off valve 11, the downstream shut-off valve 12, the upstream open valve 13, and the downstream open valve 14 shown in FIG. 1, white means open and black means close (see FIG. 2). The same). FIG. 1 shows the open / close state of the shut-off valves 11 and 12 and the open valves 13 and 14 in a normal state.

  The pressure adjustment valve 10 is a valve for adjusting the pressure of the fuel gas. The fuel gas supply apparatus 100 includes a fuel gas pipe 20 that extends from the inlet to the outlet and conveys the fuel gas to the gas engine. The pressure regulating valve 10 is provided in the fuel gas pipe 20. Based on the pressure value of the fuel gas downstream from the pressure regulating valve 10, the pressure regulating valve 10 reduces the opening degree (flow channel area) when the pressure is equal to or larger than a predetermined value, and the pressure is predetermined. When it is less than the value, the pressure of the fuel gas is adjusted by increasing the opening.

  The upstream shutoff valve 11 is a shutoff valve located on the upstream side of the two shutoff valves 11 and 12 provided in the fuel gas pipe 20. The upstream shut-off valve 11 is normally opened, but is configured to close in an emergency. In the case of an emergency here, the case where a fuel gas leak is detected by a gas leak detector (not shown) is included. By closing the upstream shut-off valve 11 in an emergency, the flow of the fuel gas supplied to the gas engine can be shut off and secondary damage can be prevented.

  The downstream shut-off valve 12 is a shut-off valve located on the downstream side of the two shut-off valves 11 and 12 provided in the fuel gas pipe 20. As with the upstream shut-off valve 11, the downstream shut-off valve 12 is normally opened, but is configured to close in an emergency. Thus, the two shut-off valves, the upstream shut-off valve 11 and the downstream shut-off valve 12, are arranged in the fuel gas pipe 20, even if one of the two shut-off valves 11 and 12 fails. This is for reliably blocking the flow of the fuel gas toward the gas engine in an emergency.

  The upstream open valve 13 is a valve provided in the upstream open pipe 21. The upstream open pipe 21 is attached to a portion of the fuel gas pipe 20 between the upstream shut-off valve 11 and the downstream shut-off valve 12 and is connected to the outside of the ship through a merging pipe 23. The upstream opening valve 13 is normally closed, but is configured to be opened in an emergency. By opening the upstream release valve 13, the fuel gas remaining between the cutoff valves 11 and 12 when the upstream cutoff valve 11 and the downstream cutoff valve 12 are closed can be discharged out of the ship.

  The downstream open valve 14 is a valve provided in the downstream open pipe 22. The downstream open pipe 22 is attached to a portion of the fuel gas pipe 20 downstream of the downstream shut-off valve 12 and is connected to the outside of the ship via a junction pipe 23. The downstream opening valve 14 is normally closed, but is configured to be opened in an emergency. By opening the downstream release valve 14, when the downstream cutoff valve 12 is closed, the fuel gas downstream from the downstream cutoff valve 12 can be discharged out of the ship.

  In this embodiment, the downstream open pipe 22 merges with the upstream open pipe 21, and a merge pipe 23 is formed on the downstream side of the merge portion 24. Further, the upstream open pipe 21 and the downstream open pipe 22 merge inside the pressure vessel 16 described later. Therefore, the upstream open pipe 21 and the downstream open pipe 22 are not exposed outside the fuel gas supply apparatus 100, and only the merge pipe 23 extends toward the outside of the ship. Thus, the number of pipes extending from the fuel gas supply apparatus 100 to the outside of the ship can be reduced by joining the upstream open pipe 21 and the downstream open pipe 22 together.

  The check valve 15 is a valve that is provided in the downstream open pipe 22 and regulates the flow of the fuel gas from the junction 24 with the upstream open pipe 21 toward the fuel gas pipe 20. That is, the check valve 15 is a valve that prevents the backflow of the fuel gas in the downstream open pipe 22. In FIG. 1, the check valve 15 is provided in a portion of the downstream open pipe 22 between the merging portion 24 and the downstream open valve 14, but is upstream of the downstream open valve 14 (closer to the fuel gas pipe 20. ).

  The pressure vessel 16 is a member that forms the outer shell of the fuel gas supply apparatus 100. The pressure regulating valve 10, the upstream shut-off valve 11, the downstream shut-off valve 12, the upstream open valve 13, the downstream open valve 14, the check valve 15, the fuel gas pipe 20, the upstream open pipe 21, and the downstream open pipe 22 described above are: All are contained in the pressure vessel 16. Further, the fuel gas supply device 100 includes a gas flow meter 30 and a gas filter 31 provided in the fuel gas pipe 20, and the gas flow meter 30 and the gas filter 31 are also accommodated in the pressure vessel 16.

  According to the classification rules, when fuel gas piping is installed, either (i) a structure capable of shutting off the room where the fuel gas piping is disposed, or (ii) a structure where the fuel gas piping is doubled is adopted. It is prescribed as follows. In the present embodiment, the latter structure is realized with a simple configuration by regarding the pressure vessel 16 as an outer pipe. Therefore, even if it is difficult to construct a device that can handle double piping, if it is installed in the pressure vessel 16, no modification is required. That is, according to this embodiment, even a complicated device can be easily installed in the vicinity of the gas engine.

  In the present embodiment, the pressure regulating valve 10, the gas flow meter 30, and the gas filter 31 that are particularly effective to be installed in the vicinity of the gas engine are installed in the pressure vessel 16. Among these, by installing the pressure regulating valve 10 in the vicinity of the gas engine, the pressure-adjusted fuel gas is immediately supplied to the gas engine, so that the responsiveness to pressure fluctuations associated with changes in operating conditions is improved. In addition, by installing the gas flow meter 30 close to the gas engine, the fuel gas pressure difference and temperature difference between the gas flow meter 30 and the gas engine inlet are reduced, thereby suppressing measurement errors and more accurate. The amount of fuel consumption can be calculated. Furthermore, by installing the gas filter 31 in the vicinity of the gas engine, the number of devices located on the downstream side of the gas filter 31 is reduced, and the risk of contamination can be reduced.

  In FIG. 1, the pressure regulating valve 10 is installed in a portion of the fuel gas pipe 20 between the downstream cutoff valve 12 and the connection position of the downstream open pipe 22, and the gas flow meter 30 is an upstream cutoff valve in the fuel gas pipe 20. 11 and the connection position of the upstream open pipe 21, and the gas filter 31 is installed in a portion downstream of the connection position of the downstream open pipe 22 in the fuel gas pipe 20. However, the installation positions of the pressure adjustment valve 10, the gas flow meter 30, and the gas filter 31 are not limited to this. Any of these can effectively function by being provided in the fuel gas supply apparatus 100.

  Further, the outlet portion 17 of the fuel gas supply apparatus 100 is configured to be a double pipe. The space between the inner pipe (fuel gas pipe 20) and the outer pipe (pressure vessel 16) of the double pipe serves as an intake port. That is, air flows into the pressure vessel 16 from the gas engine through the inner pipe and the outer pipe. Further, the pressure vessel 16 has an exhaust port 18 connected to the outside of the ship, and the air in the pressure vessel 16 is discharged to the outside of the vessel through the exhaust port 18. An exhaust device (not shown) is provided downstream of the exhaust port 18, and the air in the pressure vessel 16 is forcibly exhausted by the exhaust device. Therefore, the pressure vessel 16 has a slightly negative pressure. Since the pressure vessel 16 is configured as described above, even if a fuel gas leak occurs in the pressure vessel 16, the fuel gas is immediately discharged out of the ship.

<Flow of fuel gas>
Next, the flow of fuel gas in the fuel gas supply apparatus 100 will be described. First, at the normal time, as shown in FIG. 1, the upstream cutoff valve 11 and the downstream cutoff valve 12 are opened, and the upstream release valve 13 and the downstream release valve 14 are closed. Therefore, all the fuel gas supplied from the fuel gas tank is supplied to the gas engine through the fuel gas pipe 20.

  On the other hand, in an emergency, the upstream cutoff valve 11 and the downstream cutoff valve 12 are closed, and the upstream release valve 13 and the downstream release valve 14 are opened. Thereby, when the upstream shut-off valve 11 and the downstream shut-off valve 12 operate normally in an emergency, the flow of the fuel gas is shut off. At this time, the fuel gas remaining between the upstream shut-off valve 11 and the downstream shut-off valve 12 is discharged out of the ship through the upstream open pipe 21 and the merge pipe 23. Further, the fuel gas remaining between the downstream shut-off valve 12 and the gas engine is discharged out of the ship through the downstream open pipe 22 and the merge pipe 23.

<Flow of fuel gas at the time of failure>
Next, a case where a failure has occurred in one of the upstream cutoff valve 11 or the downstream cutoff valve 12 will be described. First, in the event of an emergency, when the downstream shut-off valve 12 out of the two shut-off valves 11 and 12 fails and can no longer be closed, the other upstream shut-off valve 11 closes to bring the fuel gas downstream from the upstream shut-off valve 11. Does not flow. Therefore, the flow of fuel gas toward the gas engine can be blocked.

  On the other hand, the situation is different when the upstream shut-off valve 11 fails. Here, if the check valve 15 is not provided in the downstream open pipe 22 as shown in FIG. 2, if the upstream shut-off valve 11 fails and cannot be closed, the fuel gas that has passed through the upstream shut-off valve 11 Passes through the upstream open pipe 21 and partly flows back through the downstream open pipe 22 and continues to flow into the fuel gas pipe 20. That is, a flow path that bypasses the downstream shut-off valve 12 is formed as shown by the two-dot chain arrow in FIG. In this case, the flow of fuel gas toward the gas engine cannot be blocked.

  However, as shown in FIG. 1, the fuel gas supply device 100 according to the present embodiment regulates the flow of the fuel gas in the downstream open pipe 22 toward the fuel gas pipe 20 (that is, the fuel gas flows backward through the downstream open pipe 22). A check valve 15 is provided. Therefore, the bypass flow path as shown in FIG. 2 is not formed, and even if the upstream shutoff valve 11 breaks down, the flow of the fuel gas toward the gas engine can be reliably shut off.

  As described above, according to the fuel gas supply apparatus 100 according to the present embodiment, even if one of the two shutoff valves 11 and 12 fails, the flow of the fuel gas toward the gas engine can be reliably shut off in an emergency. Can do. In the fuel gas supply apparatus 100 according to the present embodiment, the number of pipes extending from the fuel gas supply apparatus 100 to the outside of the ship can be reduced by joining the upstream open pipe 21 and the downstream open pipe 22.

  As described above, the embodiments of the present invention have been described with reference to the drawings. However, the specific configuration is not limited to these embodiments, and even if there is a design change or the like without departing from the gist of the present invention. It is included in the present invention.

  According to the fuel gas supply device described above, the flow of the fuel gas toward the gas engine in an emergency even if one of the shutoff valves breaks down while reducing the number of pipes extending from the fuel gas supply device toward the outside of the ship or outdoors. Can be reliably shut off. Therefore, it is useful in the technical field of a fuel gas supply device for a gas engine.

DESCRIPTION OF SYMBOLS 10 Pressure regulating valve 11 Upstream cutoff valve 12 Downstream cutoff valve 13 Upstream release valve 14 Downstream release valve 15 Check valve 16 Pressure vessel 20 Fuel gas piping 21 Upstream opening piping 22 Downstream opening piping 23 Merge piping 30 Gas flow meter 31 Gas filter 100 Fuel gas supply device

Claims (3)

A fuel gas supply device for supplying fuel gas to a gas engine,
Fuel gas piping for conveying the fuel gas to the gas engine;
Two shut-off valves provided in the fuel gas pipe and closed in an emergency;
An upstream open pipe connected to a portion between the two shutoff valves in the fuel gas pipe;
A downstream open pipe connected to a downstream portion of a shutoff valve on the downstream side in the fuel gas pipe, and joining the upstream open pipe;
An upstream opening valve provided in the upstream opening pipe and opened in the emergency;
A downstream release valve provided in the downstream release pipe and opened in the emergency;
A fuel gas supply device, comprising: a check valve provided in the downstream open pipe and regulating a flow of fuel gas toward the fuel gas pipe. A pressure adjusting valve provided in the fuel gas pipe for adjusting the pressure of the fuel gas;
A pressure vessel that forms an outer shell of the fuel gas supply device, and
The valves and the pipes including the pressure regulating valve are accommodated in the pressure vessel.
The fuel gas supply device according to claim 1. A gas filter provided in the fuel gas pipe;
A gas flow meter provided in the fuel gas pipe,
The gas filter and the gas flow meter are accommodated in the pressure vessel,
The fuel gas supply device according to claim 2.

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