JP4047532B2 - Gas engine fuel supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel supply device for a gas engine that removes oil from an oil collecting filter that collects oil mixed in fuel gas.
[0002]
[Prior art]
In general, in a gas engine using a fuel gas such as compressed natural gas or LPG (for example, disclosed in Japanese Patent Application Laid-Open No. 11-173216), in order to ensure output performance and exhaust gas performance, the engine is constantly changed according to changes in engine operating conditions It is necessary to accurately control the fuel supply amount.
Therefore, for example, a gas regulating valve device is mounted in a gas supply pipe for sending compressed natural gas. The gas regulating valve device includes a hot-wire anemometer including a flow rate detecting unit that detects the flow rate of fuel gas, and a regulating valve. By referring to the gas flow rate measured by the hot wire anemometer in the control circuit, the opening degree of the regulating valve is feedback-controlled, and an appropriate amount of compressed natural gas is sent.
[0003]
On the other hand, a rapid filling station for a compressed natural gas engine vehicle (corresponding to a gasoline station of a gasoline automobile) uses a compressor to supply high-pressure compressed natural gas to the fuel container of the compressed natural gas engine vehicle. When the compressed natural gas is supplied, the oil for lubricating the compressor may be mixed into the compressed natural gas filled in the fuel container to become mixed oil.
In such a case, there is a possibility that the measurement accuracy of the gas flow rate measured by the hot-wire anemometer cannot be ensured because the mixed oil adheres to the hot-wire anemometer. Therefore, it becomes difficult to optimally control the opening state of the regulating valve, and it may be difficult to ensure output performance and exhaust gas performance, for example. Therefore, an oil collecting filter for separating and collecting mixed oil in the compressed natural gas flowing through the gas supply pipe is required.
[0004]
The Figure 6, an example of a fuel supply system of a single point injection type compressed natural gas engine having such an oil trapping filter.
In the figure, the compressed natural gas engine 1 has a cylinder head 2. A branch pipe 4A of the intake manifold 4 is connected to the cylinder head 2 for each intake port 3 of each cylinder.
An intake pipe 5 for introducing air is connected to the intake manifold 4 via an air filter (not shown).
In the middle of the intake pipe 5, an air-fuel mixture generating device 6 that mixes compressed natural gas and air is attached, and a throttle valve 6 A is attached to a downstream portion 5 A of the air-fuel mixture generator 6 of the intake pipe 5.
One end 7 </ b> A of a gas supply pipe 7 for sending compressed natural gas to the gas mixture generator 6 is connected.
In the middle of the gas supply pipe 7, from the upstream side, a plurality of fuel containers 8, 8 for storing compressed natural gas, a fuel shut-off valve 9, a regulator 10 for adjusting the pressure of the compressed natural gas, and an oil collecting unit The filter 11 and the gas regulating valve device 12 are mounted in order.
A fuel filling port 13 is provided at the other end 7 </ b> B of the gas supply pipe 7. The compressed natural gas is filled in the fuel containers 8 and 8 through the fuel filling port 13.
[0005]
The gas regulating valve device 12 described above includes a flow rate detecting unit 12A that detects the flow rate of the fuel gas, and a regulating valve 12B. The flow rate detector 12A is connected to the input side of the control means 14 for the regulating valve, and the output side of the control means 14 is connected to the regulating valve 12B. For example, a hot wire anemometer is used as the flow rate detection unit 12A. In the control means 14, it is determined whether or not the flow rate of the compressed natural gas is an appropriate amount with reference to the optimal air-fuel ratio, and the opening degree of the regulating valve 12B is feedback controlled according to the determination, so that the appropriate amount of the compressed natural gas is accurately determined. It is supposed to be sent.
The oil collecting filter 11 is attached to the upstream portion 7 </ b> C of the gas supply valve 7 from the gas regulating valve device 12.
When filling and supplying compressed natural gas to the fuel containers 8 and 8, even if the oil for lubricating the compressor is mixed into the compressed natural gas and becomes mixed oil, it is mixed into the compressed natural gas by the oil collecting filter 11. The mixed oil separated from the compressed natural gas is collected.
Then, the oil collection filter 11 is maintained by periodically removing the mixed oil accumulated in the oil collection filter 11 or replacing the oil collection filter 11 with a new one. .
[0006]
[Problems to be solved by the invention]
However, in the conventional fuel supply device of the compressed natural gas engine 1, after the mixed oil mixed in the fuel gas is collected in the oil collecting filter 11, the maintenance of the above-described contents of the oil collecting filter 11 is performed. Work was necessary and this maintenance work was troublesome. In addition, there is a problem that the parts cost for replacing the oil collecting filter 11 is increased.
In addition, in the fuel supply device of a multi-point injection type compressed natural gas engine, there is a possibility that mixed oil mixed in the fuel gas may adhere to the injector of the fuel injection device corresponding to each cylinder, and the middle of the gas supply pipe In addition, it is desirable to install an oil collecting filter for collecting the mixed oil. Even in this case, it is necessary to periodically maintain the oil collecting filter by extracting the mixed oil accumulated in the oil collecting filter to the outside or replacing the oil collecting filter. Therefore, the maintenance work was troublesome.
[0007]
The present invention has been made to solve the above-mentioned problems, and its purpose is to automatically remove the mixed oil collected in the oil collecting filter, thereby eliminating the maintenance work and collecting the oil. It is an object to provide a fuel supply device for a gas engine that can eliminate the replacement of a filter for use.
[0008]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an intake pipe of a gas engine using fuel gas, an air-fuel mixture generating device provided in the middle of the intake pipe, a gas supply pipe connected to the air-fuel mixture generating apparatus and sending fuel gas A gas regulating valve device that is mounted in the middle of the gas supply pipe and adjusts the fuel gas to an appropriate amount; and is installed in the middle of the gas supply pipe and located upstream of the gas regulating valve device in the fuel gas. An oil collecting filter for collecting mixed oil, a connecting pipe for connecting the oil collecting filter and the intake pipe, and a normally closed on-off valve mounted in the middle of the connecting pipe; And a control means for opening the on-off valve over the entire region or part of the engine starting period .
[0009]
The invention according to claim 2 is an intake pipe for supplying air to each cylinder of a gas engine using fuel gas, a gas supply pipe for sending fuel gas, a common pipe connected to one end of the gas supply pipe, A fuel injection device that is attached to the common pipe corresponding to each cylinder and injects fuel gas into each cylinder, and is installed in the middle of the gas supply pipe to collect oil mixed in the fuel gas An oil collecting filter, a connecting pipe connecting the oil collecting filter and the intake pipe, a normally closed on-off valve mounted in the middle of the connecting pipe, and an entire area during the engine starting period Or a control means for opening the on-off valve over a part thereof.
[0010]
(Function)
In the first and second aspects of the invention, the following effects are produced.
(A) Fuel gas such as high-pressure compressed natural gas is supplied to a fuel container of the vehicle by a compressor at a fuel filling station in a vehicle equipped with a fuel supply device for a gas engine. At this time, the oil for compressor lubrication is mixed into the fuel gas to become mixed oil, and the mixed oil may be contained in the fuel gas. When the mixed oil is contained in the fuel gas, the mixed oil in the fuel gas is collected in the oil collecting filter.
(B) For example, the on-off valve is closed before the engine start period.
The on-off valve is temporarily opened for a predetermined period by the control means.
Since the pressure P2 of the fuel gas in the gas supply pipe is higher than the pressure P1 of the intake pipe, the mixed oil collected in the oil collecting filter is sucked in via the connecting pipe by the pressure P2 of the fuel gas. It is sent into the pipe and removed from the oil collecting filter.
(C) On the other hand, the control means returns the closed valve to the closed state after the predetermined period. Therefore, even if the fuel gas fed through the gas supply pipe is guided to the connecting pipe, it is blocked by the on-off valve and is not sent directly into the intake pipe.
The on / off valve is closed by the control means before the engine start period.
The on-off valve is opened by the control means during the engine start period over the entire region or part of the engine start period.
During the operation of the gas engine after the end of the period, the on-off valve returns to the closed state .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 shows an embodiment of a fuel supply device for a gas engine according to the first aspect of the present invention (hereinafter referred to as "first embodiment"), the compression of the single-point injection type as a gas engine The parts having the same structure as that of the conventional example applied to a natural gas engine will be denoted by the same reference numerals and the description thereof will be omitted, and only different parts will be described.
[0012]
In the figure, as in the conventional example, the oil collecting filter 11 is attached to the upstream portion 7C of the gas regulating valve device 12 of the gas supply pipe 7, and collects the mixed oil contained in the compressed natural gas. ,
The bottom 11 </ b> A of the oil collecting filter 11 is connected to the downstream portion 5 </ b> A from the air-fuel mixture generating device 6 of the intake pipe 5 through the connecting pipe 15. The open end 15 </ b> A of the connecting pipe 15 is located on the upstream side of the throttle valve 6 </ b> A of the intake pipe 5.
An on-off valve 16 is mounted in the middle of the connecting pipe 15. The on-off valve 16 is normally closed.
Actuator 17 is provided on the opening and closing valve 16, the actuator 17 is connected to the control means 18.
[0013]
As shown in FIGS. 2 and 3, the control means 18 opens the on-off valve 16 over the entire area T0 during the engine start period. The whole area T0 during the engine start period is a period from when the engine start is started (start position of the starter switch 20) to when the engine start is completed (ON position of the starter switch 20).
The control means 18 and the entire area T0 during the engine start period will be described.
The control means 18 is connected to a known engine start circuit 19. The engine start circuit 19 has a starter switch 20, and a start position terminal 20 </ b> A and an ON position terminal 20 </ b> B of the starter switch 20 are connected to the control means 18. A signal (start position signal of the starter switch 20) at the time of starting the engine of the engine start circuit 19 is sent to the control means 18, and the actuator 17 is operated by this signal to control the on-off valve 16 from the closed state to the open state. It is like that. A signal at the completion of engine start of the engine start circuit 19 (ON position signal of the starter switch 20) is sent to the control means 18, and the actuator 17 is operated by this signal to control the on-off valve 16 from the open state to the closed state. It has become. In FIG. 3, reference numeral 19 </ b> A is a starter motor that drives the compressed natural gas engine 1.
[0014]
Next, the operation of the present embodiment will be described.
(A) High-pressure compressed natural gas is supplied to the fuel containers 8 and 8 through the fuel filling port 13 of the gas supply pipe 7 by a compressor (not shown) at the fuel filling station to the vehicle equipped with the compressed natural gas engine 1. Is done. At that time, the oil for compressor lubrication is mixed in the compressed natural gas, so that the mixed oil may be contained in the compressed natural gas.
In this case, the mixed oil in the compressed natural gas is collected in the oil collecting filter 11.
(B) The on-off valve 16 is closed before the engine start period.
When the starter switch 20 is turned from the OFF position to the start position, the compressed natural gas engine 1 is forcibly operated by the driving force of the starter motor 19A.
At the same time, the on / off valve 16 is opened by the control means 18 over the entire area T0 during the engine start period.
Since the pressure P2 of the fuel gas in the gas supply pipe 7 is higher than the pressure P1 (intake pressure) of the downstream portion 5A of the air-fuel mixture generating device 6 in the intake pipe 5, it is trapped in the oil collecting filter 11. The collected mixed oil is instantaneously sent into the downstream portion 5A from the air-fuel mixture generating device 6 of the intake pipe 5 through the connecting pipe 15 by the pressure P2 of the fuel gas, and is removed from the oil collecting filter 11.
(C) On the other hand, the on-off valve 16 is closed during the operation period T1 of the compressed natural gas engine 1 from the end of the period T0. Therefore, even if the compressed natural gas fed through the gas supply pipe 7 is guided to the connecting pipe 15, it is blocked by the on-off valve 16 and is not sent to the downstream portion 5 </ b> A from the air-fuel mixture generating device 6 of the intake pipe 5. .
[0015]
According to the above configuration, the mixed oil collected in the oil collecting filter 11 is mixed in the intake pipe 5 by opening the on-off valve 16 over the entire area T0 during the engine starting period. It can be sent into the downstream portion 5A from the gas generating device 6 and automatically removed from the oil collecting filter 11. As a result, there is an effect that the operation of extracting the mixed oil from the oil collecting filter 11 can be eliminated, the maintenance work of the oil collecting filter 11 can be eliminated, and the replacement of the oil collecting filter 11 can be eliminated.
Further, since the compressed natural gas can be sent to the intake pipe 5 by bypassing the air-fuel mixture generating device 6 over the entire region T0 during the engine start period, an effect of starting supercharging can be achieved.
Furthermore, when the compressed natural gas engine 1 is started, the mixed oil is removed from the oil collecting filter 11 by using the starting circuit 19, and the mixed oil can be reliably prevented from adhering to the gas regulating valve device 12 and the like.
[0016]
In the present embodiment, a natural gas engine has been described as an example of a gas engine. However, the present invention is not limited to this and can be applied to, for example, an LPG engine.
In the present embodiment, the open end 15A of the connecting pipe 15 is located on the upstream side of the throttle valve 6A of the intake pipe 5, but may be located on the downstream side of the throttle valve 6A of the intake pipe 5. it can.
Furthermore, in the present embodiment, the on-off valve is opened over the entire region T0 during the engine start period, but the on-off valve 16 is opened over a part of the engine start period. You can also
For example, as shown in FIG. 4, the on-off valve 16 is opened during a period T3 (T0> T3) that has not been reached since the engine start-up and when the engine start-up is completed. The on-off valve 16 can be closed.
[0017]
FIG. 5 shows an embodiment (hereinafter referred to as “Embodiment 2”) of a fuel supply device for a gas engine according to the second aspect of the present invention. The gas engine is a multipoint injection type compressed natural gas engine. It is applied.
[0018]
In the figure, the compressed natural gas engine 31 has a cylinder head 32. A branch pipe 34A of an intake manifold 34 is connected to the cylinder head 32 for each intake port 33A of each cylinder 33.
An intake pipe 35 for introducing air is connected to the intake manifold 34 via an air filter (not shown).
A throttle valve 36 that adjusts the amount of air is attached in the middle of the intake pipe 35.
A common pipe 37D is connected to one end 37A of the gas supply pipe 37. A fuel injection device 38 is attached to each common pipe 37D corresponding to each cylinder 33, and an injector (not shown) of each fuel injection device 38 is shown. The appropriate amount of compressed natural gas is injected into each intake port 33A from the tip of
In the middle of the gas supply pipe 37, from the upstream side, a plurality of fuel containers 39, 39 for storing compressed natural gas, a fuel shut-off valve 40, a regulator 41 for adjusting the pressure of the compressed natural gas, and oil collection Filters 42 are attached in order.
The other end 37 </ b> B of the gas supply pipe 37 is provided with a fuel filling port 37 </ b> C. Compressed natural gas is filled into the fuel containers 39, 39 from the fuel filling port 37C.
The bottom portion 42 </ b> A of the oil collecting filter 42 is connected to the intake pipe 35 via the connecting pipe 43. The open end 43 </ b> A of the connecting pipe 43 is located on the upstream side of the throttle valve 36 of the intake pipe 5.
An opening / closing valve 44 is mounted in the middle of the connecting pipe 43. The on-off valve 44 is normally closed.
Actuator 45 is provided on the opening and closing valve 44, the actuator 45 is connected to the control means 46. The control means 46 is connected to a known engine start circuit 47.
The control means 46 opens the on-off valve 44 over the entire area T0 during the engine start period. The control means 46 has the same function as the control means 18 of the first embodiment (applying FIG. 2 and FIG. 3), and description thereof is omitted.
[0019]
According to the present embodiment, the same operations and effects as those of the first embodiment are obtained.
In the present embodiment, the application example described in the first embodiment can be applied.
[0020]
【The invention's effect】
According to the first and second aspects of the present invention, the mixed oil collected in the oil collecting filter is sent to the intake pipe by temporarily opening the on-off valve by the control means into the intake pipe. The mixed oil can be automatically removed from the filter for the oil, and therefore, the maintenance work of the oil collecting filter can be eliminated and the replacement of the oil collecting filter can be eliminated.
[0021]
According to the invention of claim 1, wherein, the control means, a mixed oil trapped in the oil trapping the filter, opened off valve over the entire or a portion of the engine starting period Can be sent into the intake pipe.
Therefore, at the time of starting the gas engine, it is possible to reliably prevent the mixed oil from adhering to the hot-wire anemometer or the injector of the gas regulating valve device by removing the mixed oil from the oil collecting filter using the starting circuit.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating a fuel supply device for a gas engine according to a first embodiment.
FIG. 2 is an explanatory diagram showing a relationship between a starting circuit and a control unit in FIG.
FIG. 3 is an explanatory diagram showing a relationship between an engine start period and an open / close state of an on-off valve.
FIG. 4 is an explanatory diagram showing a relationship between an engine start period and an open / close state of an on-off valve.
FIG. 5 is a configuration diagram showing a fuel supply device for a gas engine according to a second embodiment.
FIG. 6 is a block diagram showing a conventional single-point injection type compressed natural gas engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressed natural gas engine 5 Intake pipe 6 Mixture production | generation apparatus 7 Gas supply pipe 11 Oil collection filter 12 Gas adjustment valve apparatus 15 Connection pipe 16 On-off valve 18 Control means 31 Compressed natural gas engine 33 Cylinder 35 Intake pipe 37 Gas supply Pipe 37D Common pipe 38 Fuel injection device 42 Oil collecting filter 43 Connecting pipe 44 On-off valve 45 Control means

Claims (2)

An intake pipe of a gas engine using fuel gas;
An air-fuel mixture generating device provided in the middle of the intake pipe;
A gas supply pipe connected to the air-fuel mixture generating device for sending fuel gas;
A gas regulating valve device that is mounted in the middle of the gas supply pipe and regulates the fuel gas to an appropriate amount;
An oil collecting filter that is mounted in the middle of the gas supply pipe on the upstream side of the gas regulating valve device and collects oil mixed in the fuel gas;
A connecting pipe connecting the oil collecting filter and the intake pipe;
A normally closed on-off valve mounted in the middle of the connecting pipe;
A fuel supply device for a gas engine, comprising: control means for opening the on-off valve over the entire region or a part of the engine starting period . An intake pipe for supplying air to each cylinder of a gas engine using fuel gas;
A gas supply pipe for sending fuel gas;
A common pipe connected to one end of the gas supply pipe;
A fuel injection device that is attached to the common pipe corresponding to each cylinder and injects fuel gas into each cylinder;
An oil collecting filter that is mounted in the middle of the gas supply pipe and collects oil mixed in the fuel gas;
A connecting pipe connecting the oil collecting filter and the intake pipe;
A normally closed on-off valve mounted in the middle of the connecting pipe;
A fuel supply device for a gas engine, comprising: control means for opening the on-off valve over the entire region or a part of the engine starting period .

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