JPH01200052A - Backfire suppressing device in hydrogen engine - Google Patents

Abstract

PURPOSE:To prevent the generation of backfire by forming a hydrogen discharge port having an opening/closing valve, on an intake manifold, and by opening- controlling said opening/closing valve when an engine stops and discharging the hydrogen staying in the intake manifold outside. CONSTITUTION:In a hydrogen storage alloy tank 1, the hydrogen gas generated by heating a hydrogen storage alloy by the engine cooling water, etc. The generated hydrogen gas is supplied into a caburetor 6 through a filter 2. reducing valve 4, and a regulator 5, and mixed with the air supplied from an air cleaner 7, and the mixed gas is supplied into a hydrogen engine 9 through an intake manifold 8. In this case, a hydrogen discharge port 10 is formed in the upper part of the intake manifold 8, and an opening/closing valve 11 is installed at the discharge port 10. When, in a drive controller 12, the engine stop is detected from the output of a revolution detecting sensor 14, the opening/ closing valve 11 is opened to discharge the mixed gas in the intake manifold 8 outside.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydrogen engine, and more particularly to a flashback suppression device for a hydrogen engine.

[Prior Art] In recent years, various internal combustion engines using hydrogen gas, that is, hydrogen engines, have been proposed. One of the hydrogen engine systems is a premixing system. This premixing system uses a carburetor to mix air and hydrogen gas supplied from a hydrogen storage tank, supplies the mixed gas to each cylinder of the hydrogen engine via an intake manifold, and combusts it inside the cylinder. It is.

[Problems to be Solved by the Invention] However, when a hydrogen engine stalls in a premix type hydrogen engine, unburned hydrogen accumulates in the intake manifold, and when the engine is restarted, the unburned hydrogen and The concentration of hydrogen increases due to the newly inhaled hydrogen.

As a result, the mixed gas with high hydrogen concentration does not burn inside the cylinder chamber, but instead burns outside the cylinder chamber.
A so-called backfire occurs. This backfire interferes with the operation of the hydrogen engine and poses a problem in restarting the engine smoothly.

The purpose of this invention is to solve the above-mentioned problems, and when a hydrogen engine stops for some reason, to prevent backfire when starting operation caused by unburned hydrogen accumulating in the intake manifold, An object of the present invention is to provide a flashback suppression device for a hydrogen engine that allows the engine to operate smoothly.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a hydrogen engine that sucks a mixed gas consisting of hydrogen gas and air into a cylinder chamber through an intake manifold and burns it, and a hydrogen engine formed in the intake manifold. Hydrogen release port and hydrogen release port W! d An on-off valve that closes, an operation detection means that detects the operation of the hydrogen engine, and when it is detected that the hydrogen engine has stopped based on the detection signal of the operation detection means, the hydrogen accumulated in the intake manifold is removed from the hydrogen discharge port. The gist of this invention is a flashback suppression device for a hydrogen engine, which comprises a drive control means for opening an on-off valve so that the gas is discharged from the hydrogen engine.

[Operation] With the above configuration, when the hydrogen engine stops for some reason, the on-off valve opens and the hydrogen remaining in the intake manifold is discharged from the hydrogen discharge port.

[Embodiment] An embodiment embodying the present invention will be described below with reference to the drawings.

Figure 1 shows the basic configuration of a hydrogen engine and a flashback suppression device.A hydrogen storage alloy tank 1 stores hydrogen storage alloy and generates hydrogen gas by controlling heating with engine cooling water, exhaust gas, etc. It is sent to stage filter 2. The filter 2 removes alloy fine powder contained in the hydrogen gas, and supplies the hydrogen gas from which the alloy fine powder has been removed to a pressure reducing circuit including a pressure reducing valve 4 via a check valve 3. The pressure reducing circuit reduces the pressure of hydrogen gas to a predetermined pressure and supplies it to the regulator 5.

In this embodiment, the regulator 5 is the same as that used in an engine driven by LPG, and further regulates the pressure of hydrogen gas and supplies it to the carburetor 6. The carburetor 6 supplies air via an air cleaner 7, air and hydrogen gas are mixed in the carburetor 6, and the mixed gas is supplied to each cylinder chamber of the hydrogen engine 9 via an intake manifold 8.

As shown in FIG. 2, a hydrogen discharge port 10 is formed in the upper part of the intake manifold 8, and an on-off valve 11 is attached to the discharge port 10. A movable rod 13a of an electromagnetic solenoid 13 that is energized based on a drive signal from a drive control device [12] is connected to the upper surface of the on-off valve 11, and the facing valve 11 is moved up and down based on the up and down movement of the rod 13a. to open and close the hydrogen discharge port 10. Note that when the electromagnetic solenoid 13 is energized, the movable rod 13b moves downward to open the hydrogen discharge port 1.
0 is open, and on the other hand, when the current is not energized, the rod 13a is held in an upwardly moved position so as to completely close the hydrogen discharge port 10. Further, in this embodiment, one hydrogen discharge port 10 is formed, but a plurality of hydrogen discharge ports 10 may be formed.

The drive control device 12 as a drive control means is constituted by a microcomputer in this embodiment, and receives a detection signal from a rotation detection sensor 14 as an operation detection means for detecting the rotation of the output shaft of the hydrogen engine 9. engine 9
It is determined whether the hydrogen engine 9 has stopped, that is, whether the rotation speed N has become zero.

Then, when the rotational speed N becomes zero, the drive control device 12 operates a timer built in the device 12 to measure the time, and energizes the electromagnetic solenoid 13 for a predetermined time t.

In this embodiment, the rotation detection sensor 14 is constituted by a sensor such as a photocoupler or a magnetic sensing element, and is
It is designed to detect the passage of a detected object made of a light reflecting object or a magnetic material attached to a rotating body fixed to the output shaft of the sensor. The drive control device 12 then controls the rotation detection sensor 1.
The rotation speed N is calculated based on a pulse signal as a detection signal outputted from 4.

Next, the operation of the flashback suppression device configured as described above will be explained according to the operation of the drive control device.

Now, while the hydrogen engine 9 is being operated by sucking a mixture of hydrogen gas and air through the carburetor 6 and the intake manifold 8, the drive control device 12 operates based on the detection signal from the rotation detection sensor 14. The rotation speed N of the hydrogen engine 9 is calculated, and it is determined that N is zero, that is, it is not stopped, and the electromagnetic solenoid 13 is maintained in a non-energized state. Therefore, since the hydrogen discharge port 10 is closed by the on-off valve 11, the mixed gas is surely sucked into each cylinder chamber of the hydrogen engine 9 without being released from the same discharge port 10. be burned.

On the other hand, when the hydrogen engine 9 stalls and stops for some reason, or when the driver stops the hydrogen engine 9, the drive control device 12 controls the hydrogen engine 9 based on the detection signal from the rotation detection sensor 14. It is determined that the rotational speed N of the hydrogen engine 9 is zero, that is, the hydrogen engine 9 has stopped, and the electromagnetic solenoid 13 is energized for a time t. Electromagnetic solenoid 13
When the movable rod 13a is energized, the movable rod 13a moves downward.

Then, the on-off valve 11 also moves downward, and the hydrogen discharge port 10 opens only for a time t. As a result, the unburned hydrogen gas remaining in the intake manifold 8 due to the stoppage of the hydrogen engine 6 is discharged from the discharge port 10.

After this time, the drive control device 12 de-energizes the electromagnetic solenoid 13, closes the hydrogen discharge port 11, and prepares for the next operation of the hydrogen engine 9.

Therefore, when restarting the operation of the hydrogen engine 9, since the hydrogen gas in the intake manifold 8 has been removed, the hydrogen in the mixed gas sucked into the hydrogen engine 9 is newly transferred via the carburetor 6 and the intake manifold 8. This is only hydrogen gas that is sucked in. As a result, hydrogen engine 9
The concentration of hydrogen gas in the mixed gas sucked into the system does not increase, and the flashback that occurs when restarting operations, as in the past, no longer occurs.

It should be noted that the present invention is not limited to the above-mentioned embodiment, and the above-mentioned embodiment uses a cover made of a light reflecting object or a magnetic material attached to a rotating body fixed to the output shaft of the hydrogen engine 9 as an operation detection means. It was constructed with a sensor such as a photocoupler or a magnetic sensing element that detects the passage of a detection object, but this was replaced with a tacho generator that rotates relative to the rotation of the engine 9 and outputs an electromotive force, and it was also constructed with a microcomputer. The drive control device 12 as a drive control means may be implemented as shown in FIG.

The tachogenerator 21 outputs an electromotive force {circle around (2)} proportional to the rotational speed N of the hydrogen engine 9 to the inverting input terminal of the comparator 22 . The non-inverting input terminal of comparator 22 is connected to switch 2.
The variable resistor 24 is connected to a movable terminal of a variable resistor 24 which divides the voltage applied through the resistor 3 and outputs a reference voltage VS to the same terminal. Note that the switch 23 is the electromagnetic solenoid 13 in this embodiment.
This switch is controlled so that it opens after a certain period of time after the engine 6 is energized, and closes after the engine 6 has started and rotated to a certain extent.

Further, in this embodiment, the reference voltage Vs is the electromotive force V output from the tachogenerator 21 when the hydrogen engine 9 reaches a minute rotation just before stopping, and this value is determined in advance by conducting a test. The comparator 22 turns on the transistor Tr via the resistor R1 when the electromotive force V from the tachogenerator 21 becomes smaller than the reference voltage VS, that is, when the hydrogen engine 9 reaches a minute rotation just before stopping. It has become.

The transistor Tr has a resistor R2 connected between its pace emitters and an electromagnetic solenoid 13 connected to its collector terminal. When turned on by the comparator 22, the solenoid 13 is energized and the hydrogen discharge port 10 is opened. Therefore, the same effects as in the embodiment described above can be expected, and the structure is simpler and more cost-effective than in the embodiment in which the drive control means is a microcomputer.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to prevent the occurrence of flashback and restart the operation of the hydrogen engine.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the basic configuration of a hydrogen engine and a flashback suppression device embodying the present invention, Fig. 2 is a sectional view showing the installation state of the on-off valve provided at the hydrogen discharge port, and Fig. 3 is FIG. 4 is a flowchart diagram for explaining the operation of the flashback suppression device, and FIG. 4 is an electric circuit diagram of the flashback suppression device for explaining the present invention in detail. In the figure, 1 is a hydrogen engine, 6 is a carburetor, 8 is an intake manifold, 9 is a hydrogen engine, 10 is a hydrogen discharge port, 11 is an on-off valve, 12 is a drive control device as a drive control means, 13 is an electromagnetic solenoid, 13a 14 is a rotation detecting sensor as a driving detecting means, 21 is a tacho generator as a driving detecting means, 22 is a comparator as a drive controlling means, 24 is a variable resistor, and Tr is a transistor. Patent applicant: Toyoda Automatic Co., Ltd.

Claims (1)

[Claims] 1. A hydrogen engine that sucks a mixed gas of hydrogen gas and air into a cylinder chamber through an intake manifold and burns it; a hydrogen discharge port formed in the intake manifold; and a hydrogen discharge port formed in the intake manifold. an on-off valve that opens and closes; an operation detecting means for detecting operation of the hydrogen engine; A flashback suppression device for a hydrogen engine, comprising a drive control means for opening the on-off valve so that discharge is discharged from a discharge port.