FR2912783A1 - Sparkless-ignition engine controlling method for vehicle, involves controllably stopping engine in end of service, while interrupting supply of oil and diesel to eliminate oil from supply circuit, and completely stopping engine - Google Patents

Abstract

The method involves starting a sparkless-ignition engine (12) using diesel, and stabilizing engine rate while heating vegetable oil using energy from the engine. Supply of diesel to the engine is switched to supply of oil by using a three-way solenoid valve (38) when the oil is in combustion temperature. The engine is operated using the oil during service period. The engine is controllably stopped in end of service, while interrupting the supply of oil and diesel to eliminate the oil from a supply circuit. The engine is completely stopped. An independent claim is also included for a device for controlling a sparkless-ignition engine.

Description

METHOD FOR CONTROLLING AN INTERNAL EXPLOSION ENGINE OPERATING WITH TWO

FUEL, ASSOCIATED DEVICE

  The present invention relates to a method for controlling an internal combustion engine operating with two fuels of which one is capable of congealing. The invention also covers the associated device. There are many autonomous combined groups that use an internal combustion engine, such as the generators that combine this engine with a current generator and the pumping units that combine a pump with this motor. Generally, the engines are of the non-controlled ignition type using diesel fuel in particular to benefit from a significant torque for the drive, this for groups of a certain power of 10 HP up to several hundred. In addition, these groups are used in troubleshooting and / or areas where it is easier to obtain diesel fuel, the other surrounding vehicles also running on diesel fuel.

  Another advantage is the greater robustness and lower sensitivity of the engine to fuel quality. Internal combustion engines of the type operating with diesel fuel are uncontrolled and may admit other fuels because of the very high compression prevailing in the combustion chambers. This very strong compression causes a sharp rise in fuel temperature and an auto ignition.

  Thus, so-called diesel engines can operate with heavier fuels such as heavy fuel oil but also oils and in particular vegetable oils without modifying the engine block. Such an advantage is of interest when the groups concerned are on or near producing farms, are close to vegetable oil production sites or are intended for intensive use. Such groups can thus use biofuels, making it possible to offset the use of all oil for the benefit of a renewable fuel. Renewable fuels of vegetable origin can be produced regularly from renewable vegetable sources of course, often low value, can be produced in countries with low fossil fuel and at a lower cost for sale. By cons, vegetable oils have the disadvantage of freezing and can not be used at room temperature.

  This disadvantage is unacceptable for generating sets or motor pumps whose commissioning time must be very short. A delay of several minutes is necessary, even a few tens of minutes, delay totally incompatible with emergency operation. The groups are generally arranged on movable frames to allow routing to the place of use and include a reservoir for autonomous operation. The control method of an internal combustion engine without spark ignition and the associated device according to the invention aim to overcome these problems by operating with a bi fuel.

  The method and device are now described in detail, with reference to the accompanying drawings for illustrating the invention, the figures representing - Figure 1: a schematic side elevational view, and - Figure 2: an exploded schematic view of the device, the device , taken from the representations of Figures 1 and 2, comprises a frame 10 on which is disposed a motor 12, more particularly an internal combustion engine without controlled ignition with its cooling circuit. This motor is mechanically coupled to a driven member 14, for example a current generator or a pump. The chassis also carries a first reservoir 16 of diesel fuel for supplying the engine 12 with a first fluid fuel such as diesel fuel and a second reservoir 18 for supplying the engine 12 with a second freezing fuel such as an oil of vegetable origin.

  The engine environment comprises a control 20, mechanical, acceleration / deceleration and 22 means maneuver this command. In this case, these means 22 maneuver consist of an electric cylinder 24. The engine environment also includes a source 26 of electrical energy such as an accumulator and a controller 28. The device is equipped with means 30 for heating the second freezing fuel. These means 30 for heating comprise first means 32 for heating the second fuel contained in the second tank. These first means 32 may be a coil fed by the cooling water circuit or an electrical resistance dipped in said tank. The heating means 30 also comprise second means 34 for heating at the combustion temperature of the second fuel interposed on the motor supply circuit. The second heating means 34 comprises an oil heater 36 with a high heating capacity, so as to bring the second fuel to a temperature of 60 C, which greatly reduces the viscosity and the door to the combustion temperature.

  This oil heater with high heating capacity comprises an electrical resistance, the only one capable of providing the heating power sufficient to raise the temperature of the oil continuously at a temperature of 60 C. The vegetable oil raised to this temperature allows its use as a fuel of the diesel type, without any modification of the parameters of the engine operation. The motor supply means comprise a three-way solenoid valve 38 for switching the power supply of the motor 12 with the first or the second fuel.

  The means 30 for heating combustion also comprise means 40 for electric heating of the motor 12. These means 40 for electric heating comprise at least one resistor positioned in the fluid circuit for cooling the motor. Electrical connection means 42 are provided to be connected to a power source of electrical power and not accumulation, external for example provided by the network but possibly provided by an onboard generator of lower power. In order to provide the necessary electrical energy consumed by the first and second heating means 32 and 34, the device also includes an additional generator 44 driven by the motor 12. The alternator generally associated with the motor 12 is insufficient to provide the amount of electrical energy sufficient. In addition, in order to make the entire device compatible, the heating means operate at 220 volts and the current generator 44 produces 220 volts, that is to say the voltage of the home network. The alternator therefore operates at 12 volts or 24 volts and the current generator 44 operates at 220 volts.

  The method comprises the steps that will follow according to the modes of operation. 1 / first fuel supply mode: - starting of the engine 12 by a starter powered by the accumulator 26 on board, - idling speed, - increase of the speed in time step, for example 500 rev / min every 30 seconds to reach the optimized work regime. The controller 28 exerts this control through the electric cylinder 22, - stabilized operation, - controlled shutdown of the engine 12 at the end of service and complete shutdown almost simultaneous. 2 / bi fuel supply mode: - starting of the engine 12 by a starter powered by the onboard accumulator 26, - idle speed, - increase of the speed in time step, for example 500 rev / min every 30 seconds to reach the optimized work regime. The controller 28 exerts this control through the electric cylinder 22, operating in steady state mode with first fuel supply of the first tank 16, parallel heating of the second fuel of the second tank 18 and simultaneously setting to the temperature of 60 C of the second fuel contained in the feed heater 36. The generator 44 supplies the electrical energy at 220 volts, necessary for the heating up of this second fuel. automatic switching by the controller 28 of the power supply of the engine 12 which closes the supply of the first fuel and opens the supply of the engine 12 with a second fuel that has been warmed up by controlling the three-way solenoid valve 38 when this second fuel is at the supply temperature, - steady-state operation with second fuel supply, continuous heating of the second fuel by the heater 36, - controlled shutdown of the engine at the end of service and start-up by the controller. the stopping procedure simultaneously comprising the interruption of supply of second fuel and again the supply of first fuel by controlling the three-way solenoid valve 38 so as to eliminate the second fuel from the supply circuit. - complete shutdown of the engine 12. 3 / Second fuel supply mode: This occurs in the event of an unexpected engine stop working with a second fuel supply on fault, failure or emergency stop.

  The operation is disrupted because after a long interruption to overcome the fault, repair the fault or eliminate the risk associated with the emergency stop, the second fuel is too viscous or even frozen. The method then comprises the following steps: - connection of the means 42 of electrical connection to a power source of external power. - Warming the cooling fluid of the engine block to bring the second fuel still contained in the supply circuit to a suitable temperature. Detection by the controller 28 of a setpoint reached and signaling the engine ready to start. - Put into operation of the first and second means 32 and 34 for reheating to prepare the second fuel and put it in temperature, - controlled start of the engine 12 fed with second fuel, - idling speed, - increasing the speed step by step. time, for example 500 rpm every 30 seconds to reach the optimized working regime. The controller 28 exerts this control through the electric cylinder 22, - operation in steady state with a second fuel supply, - steady state operation with supply of second fuel, - controlled shutdown of the engine at the end of service and start-up by the controller 28 of the shutdown procedure simultaneously comprising the interruption of supply of second fuel and again the first fuel supply by controlling the three-way solenoid valve 38 so as to eliminate the second fuel from the fuel circuit. 'food. - Thus, thanks to the means 40 for electric heating of the engine 12, it is possible to operate the engine 12 actually bi fuel, whatever the circumstances, including restarting the motor 12 directly powered by second fuel without disassembly of any conduct whatsoever. Starting directly with the second fuel is an exception because it requires a few minutes of commissioning.

  Nevertheless, it is noted that this commissioning is on the one hand possible and on the other hand only requires a few minutes of commissioning without any disassembly. The control method is very flexible and allows driving by user personnel and not necessarily mechanic as in the devices of the prior art requiring disassembly and disabling the device for several hours.

  The PLC prevents any false operation because the sensors allow operation only if the conditions are met for the first as for the second fuel. Similarly, the switchover from the first to the second fuel is only allowed by the PLC if the conditions are met so that the user does not have to worry about the parameters and can not make mistakes by switching over too much. early or too late.

Claims (10)

  A method of controlling an internal combustion engine for driving a driven member such as a current generator or a pump operating with a feed from a first or second fuel, the second fuel being capable of to freeze, characterized in that the following steps are carried out: a. starting the engine with the first fuel, b. Stabilization of the engine speed with heating of the second fuel by energy from the engine, c. switching from the feed with the first fuel to the feed with the second fuel when the latter is at a combustion temperature, d. operation with the second fuel supply during the service period, e. controlled stopping of the engine at the end of the service with simultaneous interruption of the supply of the second fuel and again the supply of the first fuel so as to eliminate the second fuel from the supply circuit, and, f. complete shutdown of the engine.   2. A method of controlling an internal combustion engine according to claim 1, characterized in that, in case of inadvertent shutdown during the supply of second fuel, it comprises the following steps: a '. operation with the second fuel supply during the service period, b '. inadvertent shutdown with second fuel supply, c. heating the second fuel of the power supply and in the engine itself, with energy external to said engine, of. starting the engine with the second fuel, e '. Stabilization of the engine speed with heating of the second fuel by the energy from the engine, f '. operation with the second fuel supply during the service period, g '. controlled shutdown of the engine at the end of the service with simultaneous interruption of the second fuel supply and again the supply of the first fuel so as to eliminate the second fuel from the supply circuit, and, h '. complete shutdown of the engine.   3. Apparatus for carrying out the method according to claim 1 or 2 comprising an internal combustion engine (12) without controlled ignition capable of driving a member (14) led such as a current generator or a pump operating with a feed from a first or second fuel, the second fuel being capable of freezing, characterized in that it comprises a first reservoir (16) for supplying the engine (12) with a first fluid fuel, a second reservoir (18) for supplying the engine (12) with a second freezing fuel, means (30) for heating the second fuel freezing, first means (32) for heating the second fuel contained in the second tank, second means (34) for heating at the combustion temperature of the second fuel, interposed on the engine supply circuit.   4. Device according to claim 3, characterized in that the second means (34) for heating the combustion temperature of the second fuel are electric and in that it comprises means (44) for producing electrical energy integrated into the engine. (12) for supplying in particular said second heating means (34).   5. Device according to claim 3 or 4, characterized in that the second means (34) of electric heating comprises a heater (36) of the second fuel with a high heating capacity, so as to bring the second fuel to a temperature of 60 C combustion.   6. Device according to claim 4 or 5, characterized in that the means (44) for producing electrical energy work at the voltage of the home network.   7. Device according to one of claims 3 to 6, characterized in that it comprises means (40) for electric heating of the motor (12).   8. Device according to any one of claims 3 to 7, characterized in that it comprises means (42) for electrical connection provided to be connected to a power source of external power.   9. Device according to any one of claims 3 to 8, characterized in that it comprises a three-way solenoid valve (38) for switching the motor supply (12) with the first or the second fuel.   10. Device according to any one of claims 3 to 9, characterized in that it also comprises a controller (28) pipe.