LU85491A1 - IC engine heater for LPG starting - uses auxiliary heater powered by battery to preheat vaporiser before cooling water reaches required temp. - Google Patents

Abstract

The device comprises an hydraulic circuit containing a limited quantity of water and comprising the fuel expander-vaporiser (1), a water heater (2), and a circulation pump (3). The hydraulic circuit is brought into service when the temp. of the water circulating in it is less than 20 deg.C. The water is heated (2) using energy drawn from the vehicle battery so that the vaporiser reaches a temp. (greater than 40 deg.C) at which the engine can be started directly on liquid petroleum gas fuel. This is necessary whenever the engine is to be cold started or restarted after a period. The temp. is maintained during running by engine cooling water. Solenoid valves (4,5,6), actuated by the thermostats (7,8,9) direct the water flow as required by the water temp. to heat the vaporiser.

Description

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The object of the present invention is to provide a device making it possible to supply exclusively either with p_ \ liquefied petroleum gas, usually called LPG, or :: also with methane, internal combustion engines, in particular for motor vehicles.

As everyone knows, engines for motor vehicles operating on liquefied petroleum gas or on

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'3 methane, have the following disadvantage; in the regulator-vaporizer (apparatus in which the liquid fuel turns into gas), the fuel tends to cool during said transformation, possibly even reaching a temperature of 15-20 ° C below zero, 'l especially when the water temperature of the' i | i radiator is around 0 ° C.

i In these conditions, starting the engine is made difficult and sometimes even impossible.

So far, this drawback j 1 has been remedied by starting with gasoline, provided, of course, that the engine is provided with the double i'3 supply, respectively gasoline and gas of liquefied petroleum.

i ïj Normally, indeed, - and especially when the? engine is cold - we start with petrol to go 1¾ then to gas supply, when the temperature of the radiator water exceeds eO ° C.

; j,,> ί Generally, by an outside temperature

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i | around 0 ° C, you have to wait about 10 minutes before it can switch from gasoline to gas supply, but this delay is about a quarter of an hour when ii if the outside temperature is for example 20 ° C below [il / zero.

r £ 't; On the other hand, when the outside temperature approaches 30 or A0 ° C above zero, direct starting with gas poses no problem, even when the engine is equipped with double supply, j Trouble appears as soon as , by 3 \ low temperatures and when the battery is not i.

powerful enough, we want to restart it! engine which, for any reason, has stopped,; after a direct start test with gas at a fairly cool temperature.

In this case, it is observed in fact that after the engine has been running for two or three minutes, a crust of ice forms around the pressure reducer-vaporizer, - which prevents restarting the engine if, by; chance, it stops.

i - Indeed, when the temperature of the regulator- | vaporizer is less than 0 ° C, the vaporized gas coming I in contact with the walls of said regulator-vaporizer, se! liquefies and prevents ignition.

This problem is well known to anyone who owns a vehicle equipped with dual power! gas and gasoline.

i j To this end, several devices have been proposed I aiming to preheat the regulator-vaporizer; by means of an electrical resistance, supplied i by the battery; However, these systems have the drawback of requiring a battery that is always well charged, otherwise they can easily discharge it, thus causing all the troubles imaginable.

j The present invention specifically aims to allow the realization of a hydraulic circuit! relatively reduced including exclusively the pump! circulation, the regulator-vaporizer and an electric resistance water heater - which is used to heat the small amount of water contained in said hydraulic circuit, "Ü 'thus avoiding having to heat all the water in the j.

radiator - to allow direct starting of the gas engine, in any outdoor temperature condition, without having to overcharge the battery and creating the above mentioned disadvantages ι-i i à 4 \ "! | The tests carried out have shown that, | even when the battery is not fully charged, the | direct gas starting is possible without having to resort to fueling, which can therefore be completely eliminated from the circuit, without however causing any particular disadvantages.

i | The device will be described below in more detail with the aid of the appended drawings, in which: - Figure 1 shows the diagram of the hydraulic circuit "î _ cooling under normal conditions; Î- Figure 2 shows the same circuit during the start-up phase; j-j - figure 3 represents the diagram of the electric circuit

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| ï required to order the vehicle.

î As can be seen in Figures 1 and 2, î the hydraulic heating circuit includes the regulator-vaporizer 1, the water heater 2 and the circulation pump 3, placed in a hydraulic service circuit, which automatically enters into operation when the î | temperature is below 20 ° C and stops automatically when the temperature exceeds 20 ° C.

$ | The three solenoid valves 4, 5 and 6, as well as the i | three thermostats 7, 8 and 9 complete the circuit.

| Solenoid valves 4 and 6 are normally open | * when the hot engine operates normally (fig. 1), ί while the solenoid valve 5 is closed under the same S conditions. Conversely, during the start-up phase, the solenoid valves 4 and 6 are closed (fig. 2) and the solenoid valve 5 is open, thus creating a circuit I-! p closed including the expansion valve 1, the ί water heater 2 and the circulation pump 3.

s "j The three thermostats 7, 8 and 9 have the role of controlling the circuit.

In Figure 3, it should be noted that the key 10, the switch 11, the respective red 12, green 13 and flashing 14 lights as well as the switch 15 are: 5 i! · Dd placed on a panel placed on the board of the | vehicle, while thermostats 7, S and 9, I solenoid valves 4, 5 and 6, pump 3, water heater 2 and | the corresponding relays 16 and 17 are placed close to the motor.

ï | The device works as follows: | 1) In normal operation (fig. 1), when the radiator j is at temperature, the water coming from this radiator,] 'according to the arrow Fl, passes through the solenoid valve 4 open, i 5 the regulator-vaporizer 1 and The solenoid valve 6 and I then returns to the radiator in the direction of the arrow 'F2. In normal operation, the solenoid valve 5 is therefore closed, and the water heater 2 and the pump 3 are not involved in the circulation of the water.

2) When the device is in operation (fig. 2), that is to say when the water temperature is below 20 ° C, the solenoid valves 4 and 6 are closed, while the solenoid valve 5, open, circulates the water; of the radiator, without, however, involving the other elements of the device.

s Under these conditions, a reduced quantity of water j circulates in the closed circuit consisting of the pressure reducer-1 vaporizer 1, the water heater 2 and the circulation pump 3, in the direction of the arrows indicated, which h. allows this small quantity j h of water to be quickly reheated, independently of the water circulating in the radiator i ’and passing through the solenoid valve 5.

| The consumption of electrical energy in the 'water heater 2 is relatively reduced, that is to say; practically comparable to that which is necessary for defrosting the rear window of the vehicle, for which, even when the engine is stopped, the device [i 7 operates as follows: when the engine is cold (outside temperature; below 20 ° C), the key being engaged on the dashboard and put in the position immediately preceding the V \ 6 * ii start, the solenoid valves 4 and 6 are closed while the solenoid valve 5 is open.

* We therefore find ourselves exactly in L: situation represented in fig. 2, namely that a small quantity of water circulates in the circuit drawn in lines | J; hatched comprising the expansion valve 1, the I j li water heater 2 and the circulation pump 3.

y II During this phase, the water heater 2 allows

Uj bring this small amount of water to a temperature if above 20 ° C, indicated on the dashboard by the if1 Î green light 13 (fig. 3) controlled by the thermostat 9, after which the driver activates the switch 15, [| signaled by the lamp 14, and starts the engine by operating the vehicle starter.

(I Once the engine started regularly and the switch 15 actuated, the reduced circulation continues it according to the hydraulic diagram of fig. 2, as long as the water] of the radiator has not reached 20 ° C, after which the thermostat 7 restores the hydraulic circuit to the normal situation, corresponding to Fig. 1, which occurs when the water coming from the radiator, according to arrow Fl, has reached the temperature of 20 ° G.

a When the water circulating in the closed circuit m exceeds 30 ° C, the thermostat 8 cuts the electrical supply '1 „of the water heater 2, thus limiting the consumption of the battery.

3l fj 'If the engine stops for a reason | | any, the maneuver is repeated, the switch 15 -j replacing the hydraulic circuit in the position shown in fig. 2, if however the water in the radiator has not yet reached the temperature of 20 ° C.

| If the radiator water has already reached this temperature, starting is carried out normally, the hydraulic circuit being in the position illustrated in: fig. 1, i.e. without any intervention from the battery for the water heater 2.

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In other words, it is clear that this system, based on a water heater powered by the battery, but requiring only a reduced consumption because it acts on a fairly limited amount of water - which circulates L: ·· in a hydraulic circuit which does not include the H vehicle radiator - allows direct starting of; I, engine powered by liquid gas, without using j. gasoline supply and also allows the operation to be repeated several times, in case the start-up if I 3} / f | would not be immediate, without risking it <1 excessively cooling the regulator-vaporizer, which “| would make starting impossible.

1, The advantages of this device, object of 2;! the invention, are therefore obvious since it allows! possibly eliminate the petrol supply and! that it removes the need for it anyway.

In any case, the only advice to be given is to - »check whether the battery is sufficiently charged, i * j s essential condition for supplying the water heater j 2, engine stopped; consumption is however: § relatively reduced since it corresponds | approximately, as already said, to that required for the .1 defrosting of the rear window.

I The use of the device, object of the invention, | Therefore has obvious advantages: by removing 1 the disadvantage of excessive cooling of the j | regulator-vaporizer, in the event of a bad start of the engine by gas supply, it allows the engine to start after a short period of preheating of a limited quantity of water in a local circuit, thus eliminating a of the main drawbacks which, as everyone knows, are specific to the gas supply of internal combustion engines.

Of course, the invention is not limited to the embodiments shown or described, which have been chosen only by way of example.

Claims (3)

1. Device allowing the exclusive supply of l internal petroleum gas to internal combustion engines I, in particular for motor vehicles,] characterized in that it comprises a hydraulic circuit with limited quantity of water, comprising the pressure regulator-vaporizer (I), the water heater (2) and the circulation pump | '(3), the circuit being able to be put into service on command |' when the temperature of the water circulating therein is i less than 20 ° C, to heat this water quickly, the water heater (2), with relatively reduced consumption, I being supplied by the battery, so as to give the pressure regulator-vaporizer (1) a temperature sufficient to allow direct starting of the gas engine and in any case to compensate for the inevitable cooling of the pressure regulator-vaporizer (1) in the event of the engine stopping after a first gas start. \ 2. Device according to claim 1, | characterized by the fact that a series of solenoid valves (4, 5 and 6), connected to as many thermostats (7, 8 and 9), inserted into the hydraulic circuits respectively of * the water coming from the radiator, from the water leaving the water heater J (2) and the water supplying the pressure reducer! (1), allows automatic passage from the circuit | hydraulic limited (fig. 2) to the normal hydraulic circuit - i ί (fig · 1), when the water temperature has reached and j. exceeded 20 ° C, however automatically bringing the | circuit in the position illustrated in fig. 1, when, due to a bad start, the cooling of the i.r j-I "pressure reducer-vaporizer (1) lowers the temperature h of the water below 20 ° C.} J 3. Device according to claims 1 and 2, H e characterized by the fact that the indicators (12, 13 and 14), the switch (11) and the switch (15) are placed on the dashboard, close to the key (10) of the vehicle, while all the other devices, pump (3), I j * \ l water heater (2), solenoid valves (4, 5 and 6), corresponding thermostats i Ί 1 (7, 8 and 9) and relays (16 and 17), i · serving the pump and the water heater, are arranged at i. close to the engine, in order to minimize ί ί. r -, · '. ,,. quantity of water required for the compensatory precnauxtage, 1 during the start-up phase at cool temperature. H I i i II; ft j j. AT \