Unit equipped with a gaseous fuel engine

Abstract

To provide a gaseous fuel engine mounting unit capable of detecting fuel leakage. [Solution] A gaseous fuel engine mounted unit 1 comprises a gaseous fuel engine 10 and a fuel supply passage 30 for introducing gaseous fuel into the engine 10, both housed within a soundproof box 50. A housing box 20 is placed inside the housing box, forming an internal space 21 through which the cooling air generated by the engine 10's cooling fan 11 does not pass. The fuel supply passage 30 is housed within this internal space 21 together with a gas detector 25. This allows for the detection of fuel leakage from the fuel supply passage 30 while eliminating the influence of the cooling air, even when the engine 10's cooling fan 11 generates a strong cooling air within the soundproof box 50 directed towards the air-cooled heat exchanger 12.

Description

Technical Field

[0001] The present invention relates to a device (referred to as a "gas fuel engine mounted unit" in the present invention) in which a gas fuel engine (referred to as a "gas fuel engine" in the present invention), which is an internal combustion engine using a combustible gas such as hydrogen gas as fuel, a fuel supply passage for supplying fuel from a fuel source to the gas fuel engine, and other component devices are housed in a soundproof box and unitized. More specifically, the present invention relates to a gas fuel engine mounted unit capable of detecting leakage of gas fuel from the fuel supply passage.

[0002] In the present invention, the "gas fuel engine" broadly includes engines that can use gas fuel as fuel, such as gas fuel-only dedicated engines that can use only gas fuel, and engines that can selectively or mixedly use both gas fuel and liquid fuel as fuel.

Background Art

[0003] As society's interest in environmental issues has increased, the demand for decarbonization has come to be required in all fields, and the civil engineering and construction fields are no exception.

[0004] Therefore, as part of the response to such decarbonization, engines mounted on engine-driven work machines such as engine-driven generators and engine-driven compressors, which are frequently used at civil engineering and construction sites, etc., are also being considered to shift to gas fuel engines that use natural gas, which has a lower CO2 emission during combustion compared to oil fuel, or hydrogen gas, which does not generate CO2 during combustion, as fuel.

[0005] Here, as shown in Figure 4, in equipment that is a unit comprising an engine 110, a fuel supply passage 130 for supplying fuel from a fuel source 160 to the engine 110, and a work machine (not shown) driven by the engine 110, there is a risk of fuel leaking inside the soundproof box 150 due to deterioration of the piping constituting the aforementioned fuel supply passage 130, or deterioration of the sealing material provided at the connection points between the piping and joints, various valves 133, 134, 136, and other equipment.

[0006] If such a fuel leak occurs, and the fuel is a liquid fuel such as diesel, the leaking area and its surroundings will be wet with the leaked fuel, and there will be a fuel odor, making it easier to notice the leak during inspections.

[0007] However, if the fuel leaking from the fuel supply line 130 is a colorless, transparent, and odorless gaseous fuel such as hydrogen gas, such a fuel leak is difficult to detect because it cannot be perceived by human senses.

[0008] If such a gaseous fuel leak goes unnoticed and is left unattended, it is not only uneconomical, but there is also a risk of accidents such as the leaked gaseous fuel accumulating inside the soundproof box 150 and igniting.

[0009] Therefore, it is desirable to be able to detect if gaseous fuel is leaking from the fuel supply line 130.

[0010] Although this invention is not related to a gaseous fuel engine unit, Patent Documents 1 and 2, listed below, propose a method for detecting gaseous fuels such as hydrogen gas leaking inside a soundproof box. This method involves housing a detector for detecting flammable gaseous fuels such as hydrogen gas inside the soundproof box of a fuel cell power generation device that houses the fuel cell body and the fuel gas supply system (fuel supply piping, etc.) to the fuel cell body. This allows for detection of leaks of flammable fuel gas inside the soundproof box, enabling ventilation of the soundproof box. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 11-86891 [Patent Document 2] Japanese Patent Publication No. 2016-143624 [Overview of the project] [Problems that the invention aims to solve]

[0012] In the fuel cell power generation devices described in Patent Documents 1 and 2 mentioned above, a detector for detecting flammable fuel gas is installed inside the soundproof box. This allows for the detection of a colorless, transparent, and odorless gaseous fuel, such as hydrogen gas, before it reaches an ignition concentration, and the inside of the soundproof box can be ventilated, thereby avoiding the risk of ignition of the gaseous fuel inside the soundproof box.

[0013] In particular, since hydrogen gas, which is lighter than air, accumulates at the top of the soundproof box, by adopting a configuration in which a hydrogen gas detector is installed on the upper side (upper side of the paper) of the soundproof box, as described in Figure 1 of Patent Document 1 and Figure 1 of Patent Document 2, gas leaks can be detected early and efficiently.

[0014] However, even if a gas detector 155 for detecting gaseous fuel is installed, for example, at the top of the soundproof box 150 of the gaseous fuel engine mounted unit 100 shown in Figure 4, following the configuration of the fuel cell power generation device described in the aforementioned Patent Documents 1 and 2, it is difficult to detect gaseous fuel leakage while the engine 110 is operating.

[0015] In other words, a gaseous fuel engine 110 that uses a combustible gas such as hydrogen gas as fuel is also equipped with a cooling fan 111, just like a gasoline engine or a diesel engine. While the engine 110 is operating, the cooling air generated by the rotation of this cooling fan 111 is introduced into the radiator of the engine 110 or into an air-cooled heat exchanger 112 such as an oil cooler installed on the work machine.

[0016] In order to cool the coolant and oil using these air-cooled heat exchangers 112, a large amount of cooling air needs to be introduced to the air-cooled heat exchangers 112. Since the engine 110 is equipped with a relatively large cooling fan 111, a strong flow of cooling air is generated inside the soundproof box 150 while the engine 110 is operating, flowing from the air intake 151 on the wall of the soundproof box 150 towards the exhaust vent 152.

[0017] As a result, even if gaseous fuel leaks from the fuel supply passage 130, the leaked gaseous fuel is diffused by the cooling air before it reaches the gas detector 155 and is discharged outside the soundproof box 150 in a short time. Therefore, even if the gas detector 155 is installed inside the soundproof box 150, it is difficult to detect the leakage of gaseous fuel, and in particular, it is not possible to detect small amounts of gaseous fuel leakage early.

[0018] Therefore, the present invention has been made in view of the drawbacks of the above-mentioned prior art, and aims to provide a gaseous fuel engine mounting unit that can reliably detect leakage of gaseous fuel generated in the fuel supply passage housed in the soundproof box, even when a strong cooling airflow from a cooling fan is generated inside the soundproof box in conjunction with the operation of the engine. [Means for solving the problem]

[0019] The means for solving the problem are described below, along with the reference numerals used in the embodiments for carrying out the invention. These reference numerals are included to clarify the correspondence between the claims and the descriptions of the embodiments for carrying out the invention, and needless to say, they are not used restrictively to interpret the technical scope of the present invention.

[0020] To achieve the above objective, the gaseous fuel engine mounted unit 1 of the present invention is A gas fuel engine 10 that uses a combustible gas as fuel and includes a cooling fan 11, an air-cooled heat exchanger 12, and a fuel supply passage 30 that supplies gas fuel from a fuel source 60 to the gas fuel engine 10 are housed in a soundproof box 50. In the gas fuel engine-mounted unit 1 in which cooling air for the air-cooled heat exchanger 12 is generated in the soundproof box 50 by the rotation of the cooling fan 11 when the gas fuel engine 10 operates, In the soundproof box 50, a housing box 20 of the fuel supply passage 30 is arranged to form an internal space 21 through which the cooling air generated by the cooling fan 11 does not pass. The fuel supply passage 30 is housed in the internal space 21, and a gas detector 25 for detecting the gas fuel in the internal space 21 is provided (Claim 1).

[0021] In the gas fuel engine-mounted unit 1 having the above configuration, the housing box 20 has a shape having a longitudinal direction with ends (20a, 20b) on the fuel source 60 side and the gas fuel engine 10 side, respectively, the internal space 21 is communicated with the outside of the internal space 21 only through a suction port 22 provided at the lower end on one end 20a side (fuel source 60 side in the illustrated example) in the longitudinal direction of the housing box 20 and an exhaust port 23 provided at the upper end on the other end 20b side (gas fuel engine 10 side in the illustrated example), both the suction port 22 and the exhaust port 23 are opened outside the soundproof box 50, and the sensitive portion of the gas detector 25 can be arranged near the exhaust port 23 (Claim 2; see FIG. 1).

[0022] In this case, a ventilation fan 24 for generating a ventilation flow from the suction port 22 toward the exhaust port 23 in the internal space 21 may be provided at the suction port 22 or the exhaust port 23 of the housing box 20 (Claim 3; see FIG. 1).

[0023] Alternatively, instead of the above configuration, the exhaust port 23 of the storage box 20 may be opened outside the soundproof box 50, while the suction port 22 may be opened inside the soundproof box 50. In this case, a ventilation fan 24 that operates at least during the operation of the gaseous fuel engine 10 to generate a ventilation flow from the suction port 22 to the exhaust port 23 in the internal space 21 is provided at the suction port 22 or the exhaust port 23, and the sensitive part of the gas detector 25 may be provided near the exhaust port 23 (Claim 4; see Figure 2).

[0024] Furthermore, in the gaseous fuel engine-mounted unit 1 having the above configuration, an additional gas detector 26 for detecting the gaseous fuel in the internal space 21 may be provided at the upper end portion in the internal space 21 at the intermediate position in the longitudinal direction of the storage box 20 (Claim 5; see Figures 1 and 2).

[0025] Also, an additional gas detector 55 for detecting the gaseous fuel may be provided outside the storage box 20 and inside the soundproof box 50 (Claim 6).

[0026] Furthermore, the internal space 21 of the storage box 20 may be divided in the longitudinal direction of the storage box 20 to form a plurality of independent chambers 21a, 21b, and the fuel supply path 30 may be accommodated in each of the chambers 21a, 21b for each predetermined section, and in each of the chambers 21a, 21b, suction ports 22a, 22b, exhaust ports 23a, 23b, and gas detectors 25a, 25b may be provided (Claim 7; see Figure 3).

Advantages of the Invention

[0027] With the configuration of the present invention described above, the gaseous fuel engine-mounted unit 1 of the present invention can obtain the following remarkable effects.

[0028] By placing a fuel supply passage 30 housing box 20 inside the soundproof box 50 of the gaseous fuel engine-equipped unit 1, and creating an internal space 21 within the housing box 20 that does not allow the cooling air generated by the cooling fan 11 of the gaseous fuel engine 10 to pass through, and housing the fuel supply passage 30 in this internal space 21, and providing a gas detector 25 for detecting gaseous fuel in the internal space 21, it was possible to detect any leakage of gaseous fuel from the fuel supply passage 30 even while the engine 10 was operating, and therefore, even when a strong cooling air was being generated inside the soundproof box 50 by the cooling fan 11.

[0029] In particular, since the volume of the containment box 20 is significantly smaller than the volume of the soundproof box 50, compared to a configuration in which the gas detector 25 is installed inside the soundproof box 50 without the containment box 20, when the gas detector 25 is installed inside the containment box 20 to detect leaked gas, it is possible to detect leaked gas early and with high accuracy, regardless of whether or not cooling air is being generated by the cooling fan 11, even if the amount of gaseous fuel leaked is relatively small.

[0030] In a configuration where the internal space 21 of the housing box 20 is connected to the outside of the internal space 21 only by an intake port 22 provided at the lower end of one end 20a (fuel source 60 side in the illustrated example) in the longitudinal direction of the housing box 20 and an exhaust port 23 provided at the upper end of the other end 20b (gas fuel engine 10 side in the illustrated example), and both the intake port 22 and the exhaust port 23 are opened outside the soundproof box 50, the internal space 21 of the housing box 20 is not directly connected to the internal space of the soundproof box 50, and therefore, despite the relatively simple configuration, it is possible to create an internal space 21 in the housing box 20 that does not allow the cooling air generated by the cooling fan 11 to pass through.

[0031] In this configuration, by placing the sensing element of the gas detector 25 near the exhaust port (exhaust duct) 23 located at the upper end of the internal space 21, and therefore near the upper end of the internal space 21, if the gaseous fuel is a gas lighter than air, such as hydrogen gas, the gaseous fuel will accumulate in the upper part of the inside of the storage box 20, and can be easily detected by the gas detector 25 with its sensing element positioned as described above.

[0032] In particular, in a configuration in which a ventilation fan 24 is provided at either the intake port 22 or the exhaust port 23 to generate a ventilation flow from the intake port 22 to the exhaust port 23 within the internal space 21, regardless of the type of fuel gas, the gaseous fuel leaked by the operation of the ventilation fan 24 is discharged outside the machine through the exhaust port 23, and can therefore be reliably detected by a gas detector 25 with a sensing element located near the exhaust port 23.

[0033] Furthermore, instead of a configuration in which both the intake port 22 and exhaust port 23 are opened outside the soundproof box 50 (Figure 1), if a configuration is adopted in which the exhaust port 23 is opened outside the soundproof box 50 but the intake port 22 is opened inside the soundproof box 50 (see Figure 2), it is advantageous in that it is possible to create a structure that makes it difficult for dust and other debris from outside the soundproof box 50 to be drawn into the housing box 20. However, when the cooling fan 11 of the engine 10 rotates and negative pressure is created inside the soundproof box 50, the air inside the housing box 20 flows back into the soundproof box 50 through the intake port 22.

[0034] Therefore, in the configuration shown in Figure 2, where the intake port 22 is opened inside the soundproof box 50, by providing a ventilation fan 24 at either the intake port 22 or the exhaust port 23 that operates at least while the gaseous fuel engine 10 is running and generates a ventilation flow in the internal space 21 from the intake port 22 to the exhaust port 23, the internal space 21 of the housing box 20 can be prevented from being affected by the cooling air.

[0035] Furthermore, by positioning the sensing element of the gas detector 25 near the exhaust port 23, through which the gaseous fuel inevitably passes when discharged outside the machine, it was possible to reliably detect any leakage of gaseous fuel.

[0036] In a configuration in which an additional gas detector 26 for detecting gaseous fuel is provided at the upper end of the internal space 21 at an intermediate position in the longitudinal direction of the storage box 20, it was possible to roughly predict which part of the fuel supply passage 30 was leaking gaseous fuel when the ventilation fan 24 was operating.

[0037] In other words, if the gas detector (intermediate gas detector) 26 installed in the intermediate position does not detect gaseous fuel, and only the gas detector 25 installed near the exhaust port detects gaseous fuel, it is possible to predict that gaseous fuel is leaking in the fuel supply passage 30 closer to the exhaust port 23 than the gas detector 26 in the intermediate position.

[0038] On the other hand, if the gas detector 25 near the exhaust port detects gaseous fuel with a delay compared to the gas detector 26 at the intermediate position, it is possible to predict that gaseous fuel is leaking from the fuel supply passage 30 on the intake port 22 side relative to the gas detector 26 at the intermediate position.

[0039] Furthermore, in a configuration in which an additional gas detector 55 for detecting gaseous fuel is provided outside the containment box 20 and inside the soundproof box 50, it was possible to detect (for example, when the gaseous fuel engine 10 is stopped) any leakage of gaseous fuel from the portion of the fuel supply passage 30 that could not be contained within the containment box 20.

[0040] In a configuration where the internal space 21 of the housing box 20 is divided into multiple chambers 21a and 21b in the longitudinal direction, and the fuel supply passage 30 is housed in each of the chambers 21a and 21b in predetermined sections (see Figure 3), by providing gas detectors 25a and 25b in each of the chambers 21a and 21b, respectively, it was possible to identify which section of the fuel supply passage 30 was leaking gaseous fuel. [Brief explanation of the drawing]

[0041] [Figure 1] An explanatory diagram showing an example configuration of a gaseous fuel engine-mounted unit of the present invention. [Figure 2]An explanatory diagram showing another configuration example of the gaseous fuel engine mounted unit of the present invention. [Figure 3] An explanatory diagram showing yet another configuration example of the gaseous fuel engine mounted unit of the present invention. [Figure 4] A diagram illustrating the basic structure of a unit equipped with a gaseous fuel engine. [Modes for carrying out the invention]

[0042] The gaseous fuel engine mounting unit of the present invention will be described below with reference to the attached drawings.

[0043] In the following explanation, we will use hydrogen gas as an example of the gaseous fuel, but the application of the present invention is not limited to gaseous fuel engine units (hydrogen engine units) that use hydrogen gas as fuel, but is also applicable to gaseous fuel engine units that use other known gaseous fuels such as natural gas.

[0044] [Overall configuration of the gaseous fuel engine-equipped unit] Figure 1 shows the overall configuration of the gaseous fuel engine-equipped unit (hydrogen engine-equipped unit) of the present invention.

[0045] In Figure 1, reference numeral 1 denotes a gaseous fuel engine mounted unit (hydrogen engine mounted unit). This gaseous fuel engine mounted unit 1 comprises an engine 10 as an internal combustion engine that uses hydrogen gas, which is a gaseous fuel, and a fuel supply passage 30 that supplies hydrogen gas from a fuel source (hydrogen source) 60 to the engine 10, as well as a soundproof box 50 that houses these components.

[0046] In this embodiment, the engine 10 is described as a hydrogen-fired engine that operates using only hydrogen gas as fuel. However, the present invention may also be applied to a gaseous fuel engine unit 1 that is configured to supply liquid fuel such as diesel or gasoline to the engine 10 via a liquid fuel supply passage (not shown), allowing for selective supply of hydrogen fuel and liquid fuel, or simultaneous supply of hydrogen fuel and liquid fuel.

[0047] The aforementioned fuel source 60 may be a hydrogen gas cylinder, or it may be a tank filled with liquefied hydrogen. In the latter case, a vaporizer for vaporizing liquefied hydrogen to obtain hydrogen gas may be included in the configuration of the fuel source 60 along with the liquefied hydrogen tank.

[0048] The fuel supply passage 30 connected to the aforementioned fuel source 60 is for supplying hydrogen gas from the fuel source 60 to the engine 10. In the illustrated embodiment, in addition to the main supply passage 31 connecting the fuel source 60 and the engine 10, it is also equipped with a purge passage 32 that branches off from the main supply passage 31 and is used to purge the hydrogen gas in the main supply passage 31.

[0049] In the illustrated embodiment, the main supply line 31 is equipped with a check valve 33, a fuel shut-off valve 34, a manual auxiliary fuel shut-off valve 35, and a pressure regulating valve 36 in the piping, and pressure sensors 37a and 37b are provided on the primary and secondary sides of the pressure regulating valve 36, respectively.

[0050] The aforementioned check valve 33 prevents gas in the main supply line 31 from flowing back to the fuel source 60, and various known check valves can be used.

[0051] The fuel shut-off valve 34 controls the start and stop of hydrogen gas supply to the engine 10 by opening and closing the main supply passage 31, and in the illustrated embodiment, it is configured as a solenoid valve.

[0052] The manual auxiliary fuel shut-off valve 35 is provided as an auxiliary to the aforementioned fuel shut-off valve (solenoid valve) 34. It is used when the fuel shut-off valve (solenoid valve) 34 fails to operate due to a malfunction or other reason, preventing the fuel supply from being stopped, or when it is necessary to emergency stop the fuel supply. The operator can manually operate the auxiliary fuel shut-off valve 35, and it can be configured using various known manual shut-off valves.

[0053] The pressure regulating valve 36 is used to regulate the gaseous fuel from the fuel source 60 to the pressure required on the engine 10 side, and can be configured using a known pressure regulator or the like.

[0054] In this embodiment, for example, high-pressure hydrogen gas (for example, up to 14.7 MPa) from a hydrogen gas cylinder which is a fuel source 60 is reduced to the pressure required by the engine 10 (1 MPa or less) and supplied to the engine 10.

[0055] In the above explanation, the case in which the pressure adjustment of the gaseous fuel by the pressure regulating valve 36 is performed by "reducing pressure" was used as an example. However, if the pressure of the fuel required by the engine 10 is higher than the pressure of the gaseous fuel supplied from the fuel source 60, the pressure regulating valve 36 may be used to "increase the pressure" of the gaseous fuel before introducing it into the engine 10.

[0056] Furthermore, in the illustrated configuration, the pressure regulating valve 36 is located in the main supply passage 31 closer to the engine 10, but the pressure regulating valve 36 may also be located in the main supply passage 31 closer to the fuel source 60, and is not limited to the illustrated arrangement.

[0057] Furthermore, if the fuel source 60 is equipped with a pressure regulating valve such as a pressure regulator, and hydrogen gas adjusted to the required pressure on the engine 10 side can be introduced into the main supply line 31, then it is not necessary to provide a pressure regulating valve 36 in the main supply line 31.

[0058] In the illustrated configuration, the pressure sensor 37a, located on the primary side of the pressure regulating valve 36, monitors whether the pressure of the gaseous fuel before pressure regulation by the pressure regulating valve 36 is high pressure (for example, up to 14.7 MPa) from the hydrogen gas cylinder which is the fuel source 60, while the pressure sensor 37b, located on the secondary side, monitors whether the pressure of the gaseous fuel after pressure regulation by the pressure regulating valve 36 is regulated to a predetermined pressure (1 MPa or less in this embodiment).

[0059] The aforementioned purge passage 32 purges hydrogen gas remaining in the main supply passage 31 on the secondary side of the fuel shut-off valve 34 when the main supply passage 31 is blocked by the fuel shut-off valve 34 installed in the main supply passage 31, thereby preventing leakage of hydrogen gas remaining in the main supply passage 31 while the engine 10 is stopped.

[0060] This purge channel 32 is equipped with a hydrogen purge valve (solenoid valve) 38, and a bypass channel 32a is provided to bypass the hydrogen purge valve (solenoid valve) 38, and a manually operated auxiliary hydrogen purge valve 39 is provided in this bypass channel 32a.

[0061] Of these, the hydrogen purge valve (solenoid valve) 38 opens when the hydrogen shut-off valve 34 installed in the main supply passage 31 is closed, purging the hydrogen gas in the main supply passage 31 on the secondary side of the hydrogen shut-off valve 34.

[0062] The manually operated auxiliary hydrogen purge valve 39, installed in the bypass channel 32a that bypasses the hydrogen purge valve 38, is provided so that an operator can manually purge hydrogen gas in the event that the aforementioned hydrogen purge valve (solenoid valve) 38 fails to operate due to malfunction or other reasons, or when there is an urgent need to purge hydrogen gas.

[0063] In the illustrated embodiment, a configuration is shown in which a main supply passage 31 and a purge passage 32 are provided in the fuel supply passage 30 described above. However, instead of this configuration, the configuration of the present invention may be applied to a gaseous fuel engine-equipped unit 1 that does not have a purge passage 32.

[0064] Furthermore, although the illustrated embodiment describes a configuration in which a check valve 33, fuel shut-off valve 34, manual auxiliary fuel shut-off valve 35, pressure regulating valve 36, pressure sensors 37a, 37b, hydrogen purge valve 38, and manual auxiliary hydrogen purge valve 39 are provided in the fuel supply passage 30, the equipment provided in the fuel supply passage 30 is not limited to this, and some of these may be omitted, or even more equipment may be provided.

[0065] The engine 10, which receives gaseous fuel from the fuel source 60 via the aforementioned fuel supply passage 30, is connected to working equipment such as a generator and a compressor (not shown), and is configured to be able to drive these working equipment with the engine 10.

[0066] This engine 10 is equipped with a cooling fan 11 to introduce cooling air to air-cooled heat exchangers 12 such as the engine's radiator and oil coolers installed on the work equipment. While the engine 10 is operating, the cooling fan 11 rotates to introduce cooling air to the air-cooled heat exchangers 12.

[0067] The soundproof box 50, which houses the aforementioned engine 10 and fuel supply passage 30, is provided with an air intake 51 for introducing cooling air into the soundproof box 50 and an exhaust port 52 for discharging the cooling air that has cooled the inside of the soundproof box 50. When the engine 10 is in operation, the cooling fan 11 rotates, generating a flow of cooling air inside the soundproof box 50 from the air intake 51 to the exhaust port 52.

[0068] [Small box] In the gaseous fuel engine mounted unit 1 of the present invention, a housing box 20 for housing the aforementioned fuel supply passage 30 is further arranged inside the soundproof box 50 of the gaseous fuel engine mounted unit 1, which has the basic structure described above.

[0069] Then, an internal space 21 is formed within this housing box 20 that does not allow the cooling air generated by the cooling fan 11 of the engine 10 to pass through. The aforementioned fuel supply passage 30 is housed in this internal space 21, and the hydrogen gas in the internal space 21 is detected by the gas detector 25.

[0070] In this way, by detecting hydrogen gas within the internal space 21 of the containment box 20 that houses the fuel supply passage 30, it becomes possible to detect hydrogen gas leaking from the fuel supply passage 30 without being affected by the cooling air generated inside the soundproof box 50 by the cooling fan 11 of the engine 10.

[0071] The material of the storage box 20 is not particularly limited as long as it can form a space inside that does not allow the cooling air generated by the cooling fan 11 to pass through. For example, it can be made of metal, resin, or various other materials, and a combination of these materials may also be used.

[0072] If the fuel supply line 30 is equipped with equipment that can be operated manually by an operator, such as a manually operated auxiliary fuel shut-off valve 35 or a manually operated auxiliary hydrogen purge valve 39, the housing box 20 is provided with a door (not shown) so that the operator can access this equipment.

[0073] Furthermore, by applying a sealant to the door stopper, etc., the internal space 21 of the storage box 20 is prevented from being affected by the cooling air when the door is closed, and the operator can operate the manual auxiliary fuel shut-off valve 35 and the manual auxiliary hydrogen purge valve 39 housed in the internal space 21 by opening the door.

[0074] A portion of the containment box 20 (for example, the door mentioned above) may be made of a transparent material such as glass or acrylic, so that the operator can visually check the equipment inside the containment box 20 (for example, the switching position of a manual valve).

[0075] While the fuel supply line 30 may be housed in the housing box 20, hydrogen gas leakage overwhelmingly occurs at the connections between the piping and fittings, valves, sensors, etc., rather than in the piping itself. Therefore, even if a portion of the piping is located outside the housing box 20, it is preferable that fittings, valves (33-36, 38, 39), pressure sensors (37a, 37b), and other equipment are housed inside the housing box 20.

[0076] Furthermore, parts of the fuel supply passage 30 that are difficult to house within the housing box 20, such as the connection point to the engine 10 or its vicinity, do not necessarily need to be housed within the housing box 20.

[0077] In the embodiment shown in Figure 1, the housing box 20 is formed to have a longitudinal shape with the fuel source 60 side and the engine 10 side as ends (20a, 20b), respectively. The internal space 21 of the housing box 20 is connected to the outside of the internal space 21 only by an intake port 22 provided at the lower end of one end 20a (fuel source 60 side in the illustrated example) and an exhaust port 23 provided at the upper end of the other end 20b (engine 10 side in the illustrated example). Both the intake port 22 and the exhaust port 23 are opened outside the soundproof box 50.

[0078] As a result, the internal space 21 of the housing box 20 is formed as an independent space that is not directly connected to the space inside the soundproof box 50. Therefore, although the internal space 21 of the housing box 20 is located inside the soundproof box 50, it is not affected by the cooling air generated by the cooling fan 11 of the engine 10.

[0079] A ventilation fan 24 is provided in either the intake port 22 or the exhaust port 23 (in the illustrated embodiment, inside the duct leading to the exhaust port 23) of the housing box 20 to generate a ventilation flow from the intake port 22 to the exhaust port 23 within the internal space 21. This allows the housing box 20 to be ventilated by the operation of the ventilation fan 24. In addition, the sensing element of a gas detector 25 for detecting hydrogen gas, which is a gaseous fuel, is provided near the exhaust port 23 (in the illustrated example, at the entrance of the duct leading to the exhaust port 23).

[0080] In the illustrated example, the gas detector 25 itself is placed at the inlet of the duct leading to the exhaust port 23. However, it is sufficient that at least the sensing part of the gas detector 25 is placed near the exhaust port 23. For example, if the exhaust port 23 is formed at the outlet of the duct as shown in the illustration, the sensing part of the gas detector 25 may be placed inside the duct, or it may be provided on the top or side wall of the housing box 20 near the inlet of the duct.

[0081] Furthermore, in the illustrated embodiment, the aforementioned ventilation fan 24 is provided at the exhaust port 23. However, in this configuration, when leaked hydrogen gas is discharged outside the machine through the exhaust port 23, it comes into contact with the motor portion (not shown) of the ventilation fan 24. Therefore, it is preferable to use an explosion-proof motor for the ventilation fan 24.

[0082] On the other hand, if a ventilation fan 24 is installed on the intake port 22 side of the containment box 20 instead of this configuration, the motor of the ventilation fan 24 will come into contact with air introduced from outside the soundproof box 50 and will hardly come into contact with hydrogen gas. Therefore, it is not necessary to use an explosion-proof motor for the ventilation fan 24, and costs can be reduced.

[0083] In this way, a space is formed within the soundproof box 50 that does not allow the cooling air generated by the cooling fan 11 of the engine 10 to pass through, the fuel supply passage 30 is housed within the housing box 20, and a gas detector 25 is provided to detect hydrogen gas in the internal space 21 of the housing box 20. As a result, even when the engine 10 is operating and therefore a strong flow of cooling air is generated inside the soundproof box 50 by the cooling fan 11, any leakage of hydrogen gas from the fuel supply passage 30 can be immediately detected.

[0084] Furthermore, by positioning the sensing element of the gas detector 25 near the exhaust port 23 located at the upper end of the containment box 20, when using a gaseous fuel lighter than air, such as hydrogen gas, leaked hydrogen gas can move towards the upper end of the containment box 20 even when the ventilation fan 24 is not operating, and can be detected by the aforementioned gas detector 25.

[0085] Furthermore, by positioning the sensing element of the gas detector 25 near the exhaust port 23, even if the gaseous fuel is a gas heavier than air, such as propane, when the ventilation fan 24 is operating, the gaseous fuel leaked into the containment box 20 will always pass through the exhaust port 23, allowing the gas detector 25 to reliably detect the leakage of gaseous fuel.

[0086] Thus, in the configuration of the gaseous fuel engine unit 1 shown in Figure 1, if the gaseous fuel is a gas lighter than air, such as hydrogen gas, the ventilation fan 24 does not need to be operated at all times. It may be operated only when the gas detector 25 installed inside the containment box 20 detects hydrogen gas, thereby ventilating the inside of the containment box 20.

[0087] However, even when using hydrogen gas as the gaseous fuel in the configuration shown in Figure 1, it is also possible to use the system with the ventilation fan 24 running continuously.

[0088] In this case, when hydrogen gas is not detected, the ventilation fan 24 is rotated at a low speed to generate a relatively weak ventilation airflow in the internal space 21 that does not affect the detection of leaked gas by the gas detector 25. When the gas detector 25 detects hydrogen gas, the rotation speed of the ventilation fan 24 is increased to increase the ventilation speed.

[0089] Furthermore, the gaseous fuel engine-equipped unit 1 shown in Figure 1 is further equipped with an additional gas detector 55 located inside a soundproof box 50 outside the housing box 20.

[0090] As shown in Figure 1, the main portion of the fuel supply passage 30 is housed in the containment box 20. However, there are parts of the fuel supply passage 30, such as the end connected to the engine 10, that are difficult to house in the containment box 20. On the other hand, hydrogen gas can leak from the portion of the fuel supply passage 30 that is located outside the containment box 20.

[0091] Therefore, the gaseous fuel engine unit 1 shown in Figure 1 is equipped with an additional gas detector 55 near the ceiling of the soundproof box 50, so that hydrogen gas leaking into the soundproof box 50 can also be detected.

[0092] In this embodiment, where the gaseous fuel is hydrogen gas, which is lighter than air, the gas detector 55 is preferably placed near the ceiling inside the soundproof box 50, and more preferably near the ceiling above the portion of the fuel supply passage 30 that could not be housed in the storage box 20.

[0093] Thus, the hydrogen gas detector 55 installed inside the soundproof box 50 outside the containment box 20 has difficulty detecting hydrogen gas leakage while the engine 10 is operating, and therefore while cooling air is being generated by the cooling fan 11. However, it can detect leaked hydrogen gas when the cooling fan 11 stops and no cooling air is being generated inside the soundproof box 50.

[0094] Furthermore, in the configuration of the gaseous fuel engine-equipped unit 1 described in Figure 1 above, the gas detector 25 inside the containment box 20 is provided only in one location near the exhaust port 23. However, instead of this configuration, an additional gas detector 26 may be provided at the upper end of the internal space 21 at an intermediate position in the longitudinal direction of the containment box 20, as shown by the dashed line in Figure 1, to detect hydrogen gas.

[0095] In this configuration, for example, by keeping the ventilation fan 24 running at all times to create a ventilation flow within the containment box 20 from the intake port 22 to the exhaust port 23, if only the gas detector 25 near the exhaust port detects hydrogen gas, it can be predicted that hydrogen gas is leaking from the fuel supply passage 30, which is located closer to the exhaust port 23 than the intermediate gas detector 26.

[0096] Furthermore, if the exhaust port gas detector 25 detects hydrogen gas after the intermediate gas detector 26 has detected it, it can be predicted that hydrogen gas is leaking from the fuel supply passage 30 on the intake port 22 side of the intermediate gas detector 26. This makes it possible to roughly determine not only whether or not a hydrogen gas leak is occurring, but also roughly where in the fuel supply passage 30 the hydrogen gas leak is occurring.

[0097] Furthermore, if hydrogen gas is detected by any of the aforementioned gas detectors 25, 26, or 55, the operator may be notified of the hydrogen gas leak by illuminating a warning light (not shown) or by other means.

[0098] [Variation 1] In the gaseous fuel engine-equipped unit 1 described above with reference to Figure 1, the configuration in which the intake port 22 of the housing box 20 is opened outside the soundproof box 50 has been described.

[0099] In contrast, the gaseous fuel engine mounted unit 1 shown in Figure 2 employs a configuration in which the intake port 22 of the housing box 20 is opened inside the soundproof box 50, while the other configurations are the same as those of the gaseous fuel engine mounted unit 1 described with reference to Figure 1.

[0100] Thus, the intake port 22 of the housing box 20 may be an opening inside the soundproof box 50. In this case, when the cooling fan 11 rotates as the engine 10 operates and negative pressure is created inside the soundproof box 50, the air inside the housing box 20 will be drawn back into the soundproof box 50 through the intake port 22 by this negative pressure.

[0101] Therefore, in the configuration shown in Figure 2, in which the intake port 22 of the housing box 20 is opened inside the soundproof box 50, the ventilation fan 24 is operated at least while the engine 10 is running to create a ventilation flow from the intake port 22 to the exhaust port 23 inside the housing box 20, thereby preventing the internal space 21 of the housing box 20 from being affected by the cooling fan 11 of the engine 10.

[0102] In the configuration of the gaseous fuel engine-equipped unit 1 shown in Figure 2, for example, when the gas detector 25 does not detect hydrogen gas, the ventilation fan 24 is rotated at a low speed to generate a relatively weak ventilation airflow inside the containment box 20 that does not affect the detection of hydrogen gas by the gas detector 25. When the gas detector 25 detects hydrogen gas, the rotation speed of the ventilation fan 24 is increased to increase the ventilation speed inside the containment box 20.

[0103] [Variation 2] In the gaseous fuel engine mounted unit 1 described above with reference to Figures 1 and 2, the internal space 21 of the housing box 20 was formed as a single chamber. However, in the gaseous fuel engine mounted unit 1 shown in Figure 3, the internal space 21 of the housing box 20 is divided into multiple chambers (two chambers in the illustrated embodiment) 21a and 21b along the longitudinal direction of the housing box, and a predetermined section of the fuel supply passage 30 is housed in each of these chambers 21a and 21b.

[0104] In the illustrated embodiment, a partition wall 27 is provided in the internal space 21 of the storage box 20, dividing the internal space 21 into two rooms (21a, 21b) with this partition wall 27 as the boundary. However, instead of this configuration, although not shown in the illustration, the storage box 20 may be formed by connecting multiple boxes, thereby creating independent rooms within each box.

[0105] In the illustrated embodiment, the chambers 21a and 21b formed within the containment box 20 are provided with intake ports 22a and 22b and exhaust ports 23a and 23b, respectively, and ventilation fans 24a and 24b are provided for each chamber 21a and 21b, thereby enabling independent ventilation for each chamber 21a and 21b.

[0106] However, instead of this configuration, although not shown in the diagram, the outlets of the intake ports 22a and 22b provided in the two chambers 21a and 21b may be combined, or the outlets of the exhaust ports 23a and 23b may be combined, and a ventilation fan may be installed at this combined section to provide a single ventilation fan shared by the two chambers, thereby reducing the number of parts.

[0107] Furthermore, each of the rooms 21a and 21b is equipped with hydrogen gas detectors 25a and 25b, respectively, with their sensing elements positioned near the exhaust ports 23a and 23b of each room 21a and 21b, thus enabling the detection of hydrogen gas in each of the rooms 21a and 21b.

[0108] In the embodiment shown in Figure 3, the intake ports 22a and 22b of each chamber 21a and 21b are both opened outside the soundproof box 50. However, instead of this configuration, the intake ports 22a and 22b may be opened inside the soundproof box 50.

[0109] Furthermore, in the embodiment shown in Figure 3, the ventilation fans 24a and 24b are both installed on the exhaust port 23a and 23b side, but instead, a configuration in which they are installed on the intake port 22a and 22b side may be adopted.

[0110] In the configuration of the gaseous fuel engine-equipped unit 1 shown in Figure 3, ventilation fans 24a and 24b are provided in each of the chambers 21a and 21b within the housing box 20. Compared to the configurations shown in Figures 1 and 2, where a single ventilation fan 24 ventilates the entire housing box 20, the volume of the chambers ventilated by each ventilation fan 24a and 24b is significantly reduced, thereby greatly improving ventilation performance.

[0111] Furthermore, by installing gas detectors 25a and 25b in each of the chambers 21a and 21b to detect hydrogen gas, it is possible to accurately identify which section of the fuel supply line 30, contained within chambers 21a and 21b, is leaking hydrogen gas based on which chamber 21a or 21b is detected.

[0112] In the example shown in Figure 3, the internal space 21 of the containment box 20 is divided into two chambers 21a and 21b. However, the internal space 21 may be further divided, and hydrogen gas detectors may be installed in each chamber to more precisely determine which part of the fuel supply line 30 is leaking hydrogen gas.

[0113] [Other variations] In the embodiments described above, the case in which hydrogen gas is used as a gaseous fuel was explained. However, the configuration of the present invention can be widely adopted not only as a configuration for a gaseous fuel engine equipped unit that uses hydrogen gas as fuel, but also as a configuration for a gaseous fuel engine equipped unit that has an engine driven by other gaseous fuels such as natural gas.

[0114] Furthermore, this configuration may be adopted as part of a gaseous fuel engine unit 1 equipped with a gaseous fuel engine that uses not only gaseous fuels lighter than air, such as hydrogen gas, but also gaseous fuels heavier than air, such as propane.

[0115] Thus, when using a gaseous fuel heavier than air, it is preferable to keep the ventilation fans 24, 24a, and 24b installed in the containment box 20 running at all times, and to position the gas detector 55, which is housed in the soundproof box 50 outside the containment box 20, at a low position inside the soundproof box 50. [Explanation of symbols]

[0116] 1,100 Gas-fueled engine unit (hydrogen engine unit) 10,110 engines 11,111 Cooling Fans 12,112 Air-cooled heat exchanger 20 storage boxes 20a One end (of the storage box) 20b Other end (of the storage box) 21 Interior space Room 21a,21b 22,22a,22b Inlet 23, 23a, 23b Exhaust port 24, 24a, 24b Ventilation fan 25, 25a, 25b Gas detectors 26 (Intermediate) Gas Detector 27 Partition wall 30,130 Fuel supply route 31 Main supply route 32 Purge channel 32a Bypass channel 33,133 Check valve 34,134 Fuel shut-off valve 35 Manual auxiliary fuel shutoff valve 36,136 Pressure Regulating Valve 37a, 37b Pressure Sensor 38 Hydrogen purge valve 39 Manual auxiliary hydrogen purge valve 50,150 Soundproof Box 51,151 Air intake 52,152 Air exhaust port 55,155 Gas detectors 60,160 Fuel source

Claims

1. A gaseous fuel engine unit is configured to house a gaseous fuel engine that uses a flammable gas as fuel and is equipped with a cooling fan, an air-cooled heat exchanger, and a fuel supply passage that supplies gaseous fuel from a fuel source to the gaseous fuel engine, all within a soundproof box, and when the gaseous fuel engine is operating, the rotation of the cooling fan generates cooling air for the air-cooled heat exchanger within the soundproof box, The fuel supply passage housing box is placed inside the soundproof box, forming an internal space within the housing box that does not allow the cooling air generated by the cooling fan to pass through, and the fuel supply passage is housed within this internal space, A gaseous fuel engine mounting unit characterized by being provided with a gas detector for detecting the gaseous fuel in the internal space.

2. The aforementioned storage box has a longitudinal shape with the fuel source side and the gaseous fuel engine side as its ends, The aforementioned internal space is connected to the outside of the internal space only by an intake port provided at the lower end of one end of the housing box in the longitudinal direction and an exhaust port provided at the upper end of the other end. The gaseous fuel engine mounting unit according to claim 1, characterized in that both the intake port and the exhaust port are opened outside the soundproof box, and the sensing part of the gas detector is positioned near the exhaust port.

3. The gaseous fuel engine mounting unit according to claim 2, characterized in that a ventilation fan for generating a ventilation flow within the internal space toward the intake port toward the exhaust port is provided at the intake port or the exhaust port of the housing box.

4. The aforementioned storage box has a longitudinal shape with the fuel source side and the gaseous fuel engine side as its ends, The aforementioned internal space is connected to the outside of the internal space only by an intake port provided at the lower end of one end of the housing box in the longitudinal direction and an exhaust port provided at the upper end of the other end. The intake port is opened inside the soundproof box, and the exhaust port is opened outside the soundproof box. A ventilation fan is provided at the intake port or the exhaust port, which operates at least while the gaseous fuel engine is running and generates a ventilation flow within the internal space from the intake port to the exhaust port, The gaseous fuel engine mounting unit according to claim 1, characterized in that the sensing part of the gas detector is located near the exhaust port.

5. A gaseous fuel engine mounting unit according to any one of claims 2 to 4, characterized in that an additional gas detector for detecting the gaseous fuel in the internal space is provided at the upper end of the internal space at an intermediate position in the longitudinal direction of the housing box.

6. The gaseous fuel engine mounting unit according to any one of claims 1 to 4, characterized in that an additional gas detector for detecting the gaseous fuel is provided outside the housing box and inside the soundproof box.

7. A gaseous fuel engine mounting unit according to any one of claims 2 to 4, characterized in that the internal space of the housing box is divided in the longitudinal direction of the housing box to form a plurality of independent chambers, the fuel supply passage is housed in each of the chambers at predetermined intervals, and each of the chambers is provided with the intake port, the exhaust port, and the gas detector.

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