JPS5999058A - Fuel supplying device for modified gas engine - Google Patents

Abstract

PURPOSE:To prevent the inflow of condensed liquid into the engine by a method wherein the device is provided with a trap, reserving the condensed liquid of the modified gas, and a means to recirculate the condensed liquid to a modifier when the level of the condensed liquid, reserved in the trap, has become higher than a given level. CONSTITUTION:The modified gas, obtained by modifying a liquid fuel by the modifier 1, is introduced into a gas cooler 2 through a pipeline 5 and is cooled, thereafter, is separated into a gas and the condensed liquid by the trap 20 and the gas is injected into a suction air pipe from a gas control valve 3 through a surge tank 41 and a gas stop valve 42. On the other hand, the condensed liquid is reserved in the vessel of the trap 20 and when the amount of the reserved liquid has arrived at a predetermined level, a condensed liquid pump 30 is energized and the condensed liquid is discharged forcibly into a liquid fuel pipeline 4B through a recirculating path 40. Thereafter, the condensed liquid is recirculated to the modifier 1 together with the liquid fuel flowing through the pipe- line 4B. The liquid fuel is supplied to the modifier 1 by a pump 10 through a regulator 43 and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel supply device for a reformed gas engine that uses reformed gas obtained by reforming liquid fuel such as alcohol as fuel.

Examples of conventional fuel supply devices of this type include:

There is something like the one shown in Figure 1 (Japanese Unexamined Patent Publication No. 52-113
(See Publication No. 426). In FIG. 1 showing this conventional example, the reformed gas supply system includes a reformer 1 that reforms liquid fuel into a flammable reformed gas containing hydrogen and carbon oxide as main components.
, a gas cooler 2 that cools the reformed high temperature reformed gas by heat exchange with unreformed liquid fuel, and a gas cooler 2 that cools the reformed gas at a high temperature by exchanging heat with unreformed liquid fuel, and controls the supply flow rate of the non-condensable reformed gas to produce a predetermined air-fuel mixture. It is composed of a gas control valve 3, a liquid fuel pipe 4, and a gas pipe 5. A fuel flow control valve 6 is interposed in the liquid fuel pipe 4 . 7 is an intake throttle valve, 8 is an air cleaner, 9
10 is a fuel tank, 10 is a pump, and the gas control valve 3
Directly feed unreformed liquid fuel into the engine during startup or under high load.
A fuel mixture control device 13 is composed of the fuel injection valve 12 that supplies the fuel to the engine I, the intake throttle valve 7, and the like.

However, the reformed gas does not necessarily consist only of non-condensable components, but also includes water that liquefies at room temperature and pressure, unreformed alcohol, and the like. Therefore, non-condensable gas and condensed liquid coexist in the gas pipe 5 downstream of the gas cooler 2. Therefore, since the condensate accumulated in the gas pipe 5 is intermittently supplied to the engine 11 via the gas control valve 3, the engine 11 may become intermittently unstable.

The present invention has been developed in view of these conventional problems.A trap is provided in the gas piping to store the condensate generated by cooling the reformed gas, and when the condensate in the trap reaches a certain amount or more, The object of the present invention is to provide a fuel supply system for a reformed gas engine which solves the above-mentioned problems by refluxing the fuel to the liquid fuel pipe on the upstream side of the reformer using a pump.

The present invention will be explained below based on illustrated embodiments.

FIG. 2 shows an embodiment of the invention. However, in Figure 2,
Components that are the same as those in the conventional example shown in the drawings will be described with the same reference numerals. In the figure, a trap 20 is provided in the gas pipe 5 downstream of the gas cooler 2, and a condensate pump 3o is connected between the bottom of the trap 20 and the liquid fuel pipe 4B leading from the fuel flow control valve 6 to the reformer 1. They are connected through a liquid return pipe 40.

Although not related to the present invention, the trap 20 and the gas control valve 3
A surge tank 41 for temporarily storing the reformed gas and a gas cutoff valve 42 for cutting off the reformed gas supply when the reformed gas supply capacity is insufficient are installed in the gas pipe 5b between the . In addition, 1 is attached to the liquid fuel pipe 4Δ on the downstream side of the fuel pump 10.
A pyrotechnic regulator 43 is provided, and a differential pressure regulator 43 and the same (1 pyrotechnic regulator 43) are installed on the upstream side of the fuel flow control valve 6 in the liquid fuel pipe 4B that branches from the first pyrotechnic regulator 43 and reaches the reformer 1. A differential pressure regulator 45 is also interposed in the liquid fuel pipe 4C branching from the engine regulator 43 and extending to the injector 12, to suppress supply amount fluctuations due to fuel pressure fluctuations in the reformed gas supply system and the liquid fuel supply system. 46 is a valve opening setting device connected to the intake throttle valve 7.

Next, a specific configuration example of the trap 20 and the condensate pump 30 will be explained with reference to FIG. 1-The wrap 20 has a gas port 22 and a gas outlet 23 on the peripheral wall of the cylindrical container 21, and a condensate outlet 24 on the bottom wall, and a flow section 25a is fitted into the container 21 so as to be freely movable up and down. The level switch 25 is screwed onto the upper end of the container 21.

The condensate pump 30 also includes a fuel suction valve 33 connected to the condensate outlet 24 of the trap 20 and having two check valves 31 and 32 interposed in series, and a pump actuator 34 connected to the fuel suction valve 33. The pump actuator 34 has a diaphragm 38 connected to the end of a rod 37 that strokes against the urging force of a return spring 36 by the excitation force of an electromagnetic coil 35, and the diaphragm 38 and the two check valves 31
．． It has a structure in which a pump chamber 39 is formed between the pump chamber 32 and the pump chamber 39 .

The electromagnetic coil 35 is connected in series with the level switch 25 to a power source.

The operation of the fuel supply device having such a configuration will be explained. The reformed gas obtained by reforming the liquid fuel by the reformer 1 flows out into the gas pipe 5, is cooled in the gas cooler 2, and is separated into gas and condensate in the trap 20, and the gas is passed through the surge tank, The condensate is accumulated in the container 21 of the 1-lap 20. When the condensate in the container 21 exceeds a certain level, the level switch 25 is turned on due to the rise of the float 25a, the electromagnetic coil 35 of the condensate pump 30 is energized, and the rod 37 is stroked to the left in the figure. As a result, the center part of the diaphragm 38 connected to the rod 37 is pulled to the left, and the volume of the pump chamber 39 increases, so the upper check valve 31 opens and the condensate in the container 21 is sucked into the pump chamber 39. Ru. When the condensate in the container 21 flows out and the level drops, the level switch 25 with hysteresis characteristics is turned OFF and the electricity to the electromagnetic coil 35 is cut off, so that the rod 37 and the diaphragm 38 are moved to the right by the force of the return spring 36. As the fuel is returned to its original state, the lower check valve 32 opens and the condensate that had been sucked into the pump chamber 39 is pushed out to the liquid fuel pipe 4B via the condensate recirculation passage 40.
The liquid fuel is returned to the reformer 1 together with the liquid fuel flowing through the pipe 4B. In this way, the condensate pump 30 is turned OFF
By repeating 1-lap 30, the condensate level is kept almost constant, and the condensate is returned to the reformer 1 and regenerated into reformed gas, so the condensate can be supplied to the engine as it is. This can be reliably prevented and stable driving performance can be maintained.

FIG. 4 shows another embodiment of the present invention, in which the pulsation of the fuel pressure in the outlet pipe of the fuel flow control valve is used to circulate the condensate.

Immediately, the container 21 of the trap 20 contains flow I.26,
There is also provided a chaiseokharub 27 which opens and closes according to the vertical movement of the float 26 to maintain a constant level of condensed liquid in the container 21.

The outlet pipe 6I of the fuel flow control valve 6 is provided with a jiggle valve 62 that opens when the fuel ratio 1'' pressure decreases, and the jiggle valve 62 and the condensate outlet of the trap 20 are connected via the condensate return pipe 40. It is.

To explain the function of this, the fuel flow control valve 6 controls the fuel supplied to the reformer l by changing the valve opening pulse width, so the fuel pressure in the outlet pipe 61 pulsates as the fuel flow control valve 6 opens and closes. do. When this pressure becomes negative, the jiggle valve 62 opens, and the condensate in the 1-lamp 20 is supplied to the reformer 1 together with the unreformed liquid fuel flowing out from the outlet pipe 61.

With such a configuration, a level switch, a condensate pump, and an electric circuit for driving the same are not required, and only a valve with a simple structure is required, so that it can be manufactured at low cost.

Incidentally, a similar purpose has already been filed by the present applicant (Japanese Patent Application No. 56-38735), but in this case, reformed gas condensate is mixed into liquid fuel when unreformed liquid fuel is used. The problem is that if only reformed gas is operated for a long time, the condensate that overflows at the tramp without being refluxed may mix with the reformed gas and be supplied to the engine. is left behind. In this regard, since the present invention has a configuration in which the condensate is returned to the reformer, the above-mentioned difficulty can also be solved.

As explained above, according to the present invention, an L-rap is provided to store the condensate of the reformed gas, and when the condensate stored in the trap exceeds a certain level, it is returned to the reformer. Since the configuration includes the means, it is possible to reliably avoid supplying the reformed gas condensate directly to the engine, and the engine operating state can be stably maintained.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a fuel supply system of a conventional reformed gas engine, FIG. 2 is an overall configuration diagram showing an embodiment of the present invention, and FIG. FIG. 4 is a sectional view of a main part showing a second embodiment of the present invention. 1... Reformer 4B... Liquid fuel piping 5.
...Gas piping 6...Fuel flow control valve 20...
・L wrap 30... Condensate pump 40... Condensate return pipe 61... Output I pipe 62... Jiggle hybrid patent applicant Nissan Motor Co., Ltd. agent Patent attorney Fujio Sasashima No. 3 Figure 4

Claims (1)

[Claims] In a reformed gas engine that uses reformed gas obtained by reforming liquid fuel in a reformer filled with a reforming catalyst as fuel, the reformed gas that supplies the reformed gas downstream of the reformer to the engine. A trap for storing the condensate of the reformed gas is provided in the passage, and a condensate reflux means is provided for refluxing the liquid fuel to the liquid fuel passage leading to the reformer when the condensate of the trump reaches a predetermined amount or more. 1. A fuel supply device for a reformed gas engine, characterized in that it is configured with: