JPS5831452B2 - Nenshiyoukikan - Google Patents

Description

Detailed Description of the Invention The present invention involves catalytically cracking methanol, reforming it into a gaseous fuel whose main components are CO and H2, and combusting this reformed gaseous fuel in an engine. This invention relates to a combustion engine that enables smooth operation, reduces harmful exhaust gas components, and improves fuel efficiency.

The object of the present invention is to obtain a combustion engine equipped with a reformer that can catalytically crack part or all of methanol to efficiently reform it into a gaseous fuel rich in H2 and CO.

Hereinafter, the present invention will be described in detail from the embodiments shown in the drawings.

In FIG. 1, 1 is an internal combustion engine as a combustion engine, and this internal combustion engine 1 includes a cylinder block 3 in which a cylinder 2 is formed, a piston 4 that reciprocates within the cylinder 2 of this cylinder block 3, and a cylinder block 3. A cylinder head 5 is bolted and fixed via a gasket or the like to the cylinder head 5,
An intake hole 8 communicates with a combustion chamber 6 formed in the cylinder head 5 via an intake valve 7, and an exhaust hole 10 communicates with the combustion chamber 6 via an exhaust valve 9. An exhaust pipe 11, a fuel reformer 12 inserted into the exhaust pipe 11, and an intake hole 8 to which fuel reformed by the fuel reformer 12 is supplied via a pipe 13 and a mixer 14. The intake pipe 14a is connected to the intake pipe 14a.

Further, the fuel reformer 12 has an inner cylinder 1 that communicates with the exhaust hole 11.
5, an outer cylinder 16 provided at a predetermined interval on the outer circumference of the inner cylinder 15, a catalyst chamber 17a formed by the outer cylinder 16 and the inner cylinder 15, and a catalyst 1 inserted in the catalyst chamber 17a.
7, one end is supplied with methanol 2 through a valve 18 and a pump 19.
0 is placed in the tank 21, and the other end is connected to the inner cylinder 15.
The catalyst chamber 17a is arranged so that it can be sufficiently heated within the catalyst chamber 17a.
methanol supply pipe 22 connected to the inner cylinder 15;
an auxiliary burner 23 with a point stopper provided on the upstream side of the
It is comprised of a pipe 25 connected to the pump 19 via a valve 24 for supplying methanol to the auxiliary burner 23, and a blower 26 for supplying air to the auxiliary burner 23.

In the case of the above configuration, the auxiliary burner 23 is connected to the tank 2.
1, methanol 20 is supplied from a pipe 25 via a methanol supply pipe 22, a pump 19 and a valve 24, and air is supplied by a Q blower 26 to ignite and burn it, and the temperature of the catalyst 17 is set to the methanol decomposition temperature (300
Burn until reaching ~400'C).

As a result, methanol supplied into the catalyst chamber 17a by the methanol supply pipe 22 via the pump 19 and the valve 18 is decomposed and reformed into a gaseous fuel rich in H2 and CO, which is then supplied to the air-fuel mixture 14.

When the internal combustion engine 1 is cranked and started in this state, the air-fuel mixture 14 is mixed with air and supplied to the combustion chamber 6 through the intake hole 8 and the intake valve 7 .

Note that the combustion chamber of this embodiment has an ignition plug (not shown) and ignites the air-fuel mixture using this, which is the same as in a normal spark ignition type engine.

The exhaust gas combusted in this combustion chamber 6 is then transferred to an exhaust valve 9.
It is discharged to the exhaust hole 10 and the exhaust pipe 11 through the exhaust hole 10 and the exhaust pipe 11.

This exhaust gas heats the fuel reformer 12 inserted into the exhaust pipe 11.

Therefore, the combustion of the auxiliary burner 23 is reduced accordingly.

In addition, if the exhaust temperature is high and the fuel reformer 12 becomes high temperature even if the auxiliary burner 23 is stopped, the auxiliary burner 2
3, only air is supplied into the inner cylinder to cool the catalyst 17 and keep it at an appropriate temperature for reforming.

Furthermore, since the internal combustion engine is normally operated at an excess air ratio λ of approximately 2, the blower 26 may be stopped by supplying only methanol to the auxiliary burner 23 by utilizing the residual oxygen in the exhaust gas.

Furthermore, by supplying a mixture of reformed gas and residual fuel, that is, unreformed methanol fuel, to the combustion engine, smooth operation with a lean mixture can be achieved.

Next, an embodiment of the second invention shown in FIG. 2 will be described.

In the description of this embodiment, parts ζ that are considered to have the same or equivalent structure as those of the previous embodiment in terms of function will be designated by the same reference numerals as those of the previous embodiment, and redundant explanation will be omitted.

The embodiment shown in FIG. 2 (here, the main differences from the embodiment shown in FIG. This configuration is such that gas components can be supplied from the gas-liquid separator 28 to the mixture 14 and condensed components can be supplied to the auxiliary burner 23 via a pump 29 and a valve 30 and a pipe 31. By doing so,
Substances such as undecomposed (20 to 30%) methanol, formaldehyde, methyl formate, etc. can be burned in the auxiliary burner 23.

Therefore, it is possible to efficiently prevent the adverse effects of the above-mentioned substances on each device.

The reason is as follows.

The methanol decomposition product from the reformer contains condensed components such as methanol and formaldehyde, which are difficult to burn.If these are sent to the engine, the condensed components will not only enter the air-fuel mixture metering section but also the combustion chamber. (Because it is an intermittent combustion, there are times when the temperature is low.) It tends to adhere to other engine equipment and harm the performance of the engine.

Therefore, in the second invention, the condensed component is separated and used as fuel for the auxiliary burner.In this way, the exhaust system serves as a collection point for the exhaust gas from each cylinder and also as a place where high-temperature expanded gas flows. Therefore, it can be regarded as a continuous combustion system, and the components that are difficult to burn in the engine combustion chamber can be reliably burned to prevent adverse effects on various devices.

As is clear from the above description, according to the present invention, part or all of methanol can be catalytically cracked and efficiently reformed into a gaseous fuel rich in H2 and CO.
By supplying this fuel, it is possible to smoothen operation with a lean mixture (this can reduce harmful components contained in exhaust gas and improve fuel efficiency).

In addition, since the fuel reformer is heated by the auxiliary burner, it is possible to make up for the lack of decomposition heat during steady operation, and there is an advantage that the warm-up time can be shortened during startup.

Furthermore, the condensed components in the methanol decomposition products are preferentially combusted by the auxiliary burner, which has excellent advantages such as preventing the accumulation of intermediate products such as formaldehyde and preventing adverse effects on various equipment. be.

Note that the present invention is applicable not only to spark ignition engines but also to compression ignition engines.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing one embodiment of the present invention, and FIG. 2 is a schematic explanatory diagram showing an embodiment different from FIG. 1. 1... Internal combustion engine as a combustion engine, 2...
...Cylinder, 3...Cylinder block, 4.
... Piston, 5 ... Cylinder head,
6... Combustion chamber, 7... Intake valve, 8...
...Intake hole, 9...Exhaust valve, 10...
...Exhaust hole, 11...Exhaust pipe, 12...
・Fuel reformer, 13...pipe, 14...
...Mixer, 14a...Intake pipe, 15...
...Inner cylinder, 16...Outer cylinder, 17...
Catalyst, 17a... Catalyst chamber, 18... Valve, 19... Pump, 20... Methanol, 21... Tank, 22... ...Methanol supply pipe, 23...Auxiliary burner, 24.
...Valve, 25...Pipe, 26...
...Blower, 27...Condenser, 28.
...gas-liquid separator, 29 ...pump, 30
... Valve, 31 ... Pipe O

Claims (1)

[Claims] 1 Part or all of methanol is catalytically cracked in a reformer to reform a gaseous fuel rich in hydrogen (H2) and carbon oxide (CO), and this reformed gas or reformed gas is reformed. In a combustion engine that uses a mixture of gas and residual fuel as fuel, the reformer includes an inner cylinder inserted into an exhaust pipe of the combustion engine, and an outer periphery of the inner cylinder (which is provided at a predetermined interval). a catalyst chamber formed by the outer cylinder and the inner cylinder, a catalyst inserted into the catalyst chamber, one end of which is connected to a methanol tank, and the other end of which is heated by exhaust gas within the inner cylinder. a methanol supply pipe arranged as shown in FIG. The system consists of an auxiliary burner, a device for supplying fuel to the auxiliary burner, and a device for supplying air to the auxiliary burner. At the same time, when the combustion engine is started or when the exhaust gas temperature is low, the fuel is supplied to the auxiliary burner by the device that supplies the fuel, and when the exhaust gas temperature is high, the air supply device is used to supply only air. 2. The combustion engine ζ according to claim 1, wherein:
In the pipe system that transports the methanol decomposition product from the reformer to the engine, there is a system in which the methanol decomposition product is cooled and its gas components are supplied as fuel for the engine, and the condensed components separated by cooling are used as fuel for the auxiliary burner. A combustion engine characterized by being equipped with a supply device.