FR2615909A1 - Device for cold starting an engine using methanol - Google Patents

Abstract

The subject of the present invention is a device for cold starting an internal combustion engine operating on methanol comprising a catalytic reactor with microporous aluminium balls impregnated with palladium and built up to a temperature for dissociation of the methanol using electrical means 2. According to the invention, the device includes an accumulation tank 18 for the dissociation gases of a sufficient capacity to allow the engine to be started.

Description

The invention relates to a device for cold starting an internal combustion engine operating with methanol.

We know that, to start such an engine, it is necessary to carry out a catalytic dissociation of methanol beforehand and that this dissociation gives mainly hydrogen and carbon monoxide.

The catalyst generally used for dissociation consists of alumina beads. microporous impregnated with palladium and brought to a temperature close to 3000 C.

Several devices have already been proposed for cold starting an internal combustion engine operating with methanol by practicing catalytic dissociation of methanol during startup, in particular by using a heating plug or an electrical resistance surrounding the catalytic reactor.

These devices have not been satisfactory because the electric power which can reasonably be obtained using an on-board electric accumulator is insufficient to generate a flow of dissociated gases allowing the starting.

The present invention relates to a device for cold starting a methanol engine, which avoids this drawback.

This device is characterized in that it comprises a reservoir for accumulating dissociation gases of sufficient capacity to allow the engine to start.

An embodiment of the device according to the invention has been described below, by way of non-limiting example, with reference to the accompanying drawings in which
Figure 1 is a diagram of the device;
Figure 2 is an axial sectional view
of the reactor.

In Figure 1, we see a reactor 1 which contains microporous alumina beads impregnated with palladium and is intended to ensure the catalytic dissociation of methanol. This reactor, which will be described in detail below, contains a heating element 2.

A circuit 3 connects the heating element 2 to the negative terminal of the vehicle battery; a circuit 4 on which an ammeter 5 and a contact 6a of a power relay 6 are interposed, connects it to the positive terminal of this battery. On the control circuit of relay 6 is interposed a contact 7a of a regulator 7.

The latter which is put into service by a switch 8 is connected to a thermocouple 9 arranged inside the reactor 1. Thus, when the switch 8 is closed, the heating element 2 is turned on or off in according to the instructions given by the thermocouple 9.

The inlet of reactor 1 is connected by a conduit 10 on which an injector 11 is interposed, to a pump 12 for supplying liquid methanol. The supply circuit 13 of the injector 11 is connected to the battery by a frequency generator 14 which regulates the methanol supply rate of the reactor 1. A switch 15 is interposed on the circuit 16 connecting the generator to the battery of frequency 14 and the pump 12, the operation of this switch thus having the effect of bringing methanol to reactor 1.

The outlet of reactor 1 is connected by a line 17 to a buffer tank 18 provided with a pressure gauge 19 and with a purge valve 20. This tank is connected to the engine by a supply line 21 on which an electro is interposed -valve 22 controlled by a switch 23.

As seen more particularly in FIG. 2, the reactor 1 comprises a quartz tube 24, the two ends of which are closed in leaktight manner by two flanges 25 and 26 provided with electrical terminals 27 and 28 and axial connections 29 and 30 for the arrival of liquid methanol and the outlet of the decomposition gases towards the reservoir 18. The two flanges 25 and 26 are held in abutment on the quartz tube 24 by tie rods 31.

Resistant wires 32, which constitute the heating element 2, are arranged longitudinally inside the tube 24, in contact with the microporous alumina balls. The electrical contacts between the tensioned resistive wires 32 and the flanges 25 and 26 are produced by transverse screws 33. The resistive wires 32 which are preferably four in number are thus mounted in parallel.

A bore 34 in the outlet flange 26 allows the introduction of the thermocouple 9 inside the tube 24 among the alumina balls.

The liquid methanol flow rate is of the order of 250 to 300 cm3 per hour and the regulated temperature around 3000 C. After approximately two minutes of heating, the decomposition gases mainly hydrogen and carbon moxoxide, accumulated in the reservoir 18 reach a pressure of the order of 1.5 bar indicated by the pressure gauge 19. The starter can then be actuated. As soon as the engine is running, the starting circuit is cut by operating the switch 8 and the solenoid valve 11 delivers liquid methanol directly into the engine.

It goes without saying that the present invention should not be considered as limited to the embodiment described and shown, but on the contrary covers all variants thereof.

Claims (4)

Claims. 1. - Device for cold starting an internal combustion engine operating with methanol comprising a catalytic reactor with alumina balls. microporous impregnated with palladium and brought to a temperature for dissociation of methanol by electrical means (2), characterized in that it comprises a reservoir for the accumulation (18) of dissociation gases of sufficient capacity to allow the starting of the engine. 2. - Device according to claim 1, characterized in that it comprises information means (19) to indicate that the pressure of the dissociation gas in the tank (18) is sufficient for starting. 3. - Device according to claim 1 or 2, characterized in that the electrical means (2) for heating the reactor consist of taut resistant electrical wires (32) mounted in parallel and arranged inside the reactor itself among the balls alumina. 4. - Device according to claim 3, characterized in that the temperature of the reactor during heating is regulated using a thermocouple (9) disposed inside the reactor among the alumina beads.