阅读说明：本技术 用于借助于燃料蒸发器对预燃腔主动扫气的燃料供应系统 (Fuel supply system for actively scavenging a prechamber by means of a fuel evaporator ) 是由 K·米歇尔斯 D·哈格尔斯坦 于 2020-09-03 设计创作，主要内容包括：本发明涉及一种用于利用气态的燃料(K)对汽油机式地运行的内燃机(30)的至少一个预燃腔(32)进行主动扫气的燃料供应系统(100),其中,所述内燃机(30)包括至少一个主燃烧腔(31),该主燃烧腔与所述至少一个预燃腔(32)至少在燃料侧处于连接。设置成,在所述至少一个预燃腔(32)上游布置有蒸发器(11)。(The invention relates to a fuel supply system (100) for actively scavenging at least one prechamber (32) of a gasoline-operated internal combustion engine (30) with gaseous fuel (K), wherein the internal combustion engine (30) comprises at least one main combustion chamber (31) which is connected to the at least one prechamber (32) at least on the fuel side. It is provided that an evaporator (11) is arranged upstream of the at least one prechamber (32).)

1. Fuel supply system (100) for actively scavenging at least one prechamber (32) of a gasoline-operated internal combustion engine (30) with gaseous fuel (K), wherein the internal combustion engine (30) comprises at least one main combustion chamber (31) which is connected to the at least one prechamber (32) at least on the fuel side, characterized in that an evaporator (11) is arranged upstream of the at least one prechamber (32).

2. Fuel supply system (100) according to claim 1, characterized in that the evaporator (11) is arranged between a feed pump (10) for supplying fuel (K) in the gaseous state only to the at least one prechamber (32) and the at least one prechamber (32)_gasf、K_gasf’) Wherein the fuel supply system (100) further comprises a high-pressure pump (20) for supplying fuel (K) in liquid state only to the at least one main combustion chamber (31)_fl)。

3. Fuel supply system (100) according to claim 1, characterized in that the evaporator (11) is comprised between a high-pressure pump (20) and the at least one prechamber (32) for supplying the at least one prechamber (32) with fuel (K) in gaseous state_gasf、K_gasf’) Wherein the high-pressure pump (20) is also used for supplying the at least one main combustion chamber (31) with liquid fuel (K)_fl) So as to branch off downstream of the high-pressure pump (20) from a supply line (20a) to the at least one main combustion chamber (31) a supply line (20e) to the evaporator (11).

4. Fuel supply system (100) according to claim 1, characterized in that it is adapted to evaporate fuel (K) in liquid state_fl) Is provided with heating means (11c) or is in connection with heating means (11c) for heat supply.

5. Fuel supply system (100) according to claim 4, characterized in that the evaporator (11) is provided with a separate heating device.

6. Fuel supply system (100) according to claim 4, characterized in that the evaporator (11) is coupled into a preheating of the internal combustion engine (100) for cold start.

7. Fuel supply system (100) according to claim 4, characterized in that the evaporator (11) is constructed in a heat exchanger embodiment, wherein heat is taken off by the cooling water of the internal combustion engine (100) and supplied to the evaporator (11).

8. Fuel supply system (100) according to claim 1 and 2 or 1 and 3, characterized in that a regulating mixing valve (12) is arranged between the evaporator (11) and the at least one prechamber (32), via which regulating mixing valve the gaseous fuel (K) evaporated in the evaporator (11) can be fed_gasf) Supplying another gaseous fluid, in particular air, so as to supply the at least one prechamber (32) with unmixed gaseous fuel (K) optionally in a predefinable ratio_gasf) Or fuel vapor/air mixture (K)_gasf’)。

9. Method for actively scavenging at least one prechamber (32) of a gasoline-operated internal combustion engine (30) with gaseous fuel (K), wherein the internal combustion engine (30) comprises at least one main combustion chamber (31) which is connected at least on the fuel side to the at least one prechamber (32), characterized in that the liquid fuel (K) is supplied to the at least one prechamber (32) before it is supplied to the at least one prechamber (32)_fl) Evaporating in an evaporator (11) arranged upstream of the at least one prechamber (32).

Technical Field

The invention relates to a fuel supply system for actively scavenging a prechamber (Vorkammer) of a gasoline-operated internal combustion engine with fuel vapor or a fuel vapor/air mixture.

Background

Documents CH 683938 a5 and DE 69228131T 2, in which prechambers or prechamber-like regions are disclosed as follows, form prior art of this type. Documents WO 2019/068484 a1 and DE 102004043143 a1 describe the supply of fuel from a prechamber spark plug into the prechamber. In WO 2019/068484 a1 it is known to scavenge the prechamber with fresh gas, which comprises at least fuel and air, so that an ignitable fuel-air mixture is contained in the prechamber at the time of ignition.

Disclosure of Invention

The object of the invention is to provide a fuel supply system for actively scavenging the prechamber of a gasoline-operated internal combustion engine and a corresponding method.

The starting point of the invention is a fuel supply system for actively scavenging at least one prechamber of a gasoline-operated internal combustion engine with gaseous fuel, wherein the internal combustion engine comprises at least one main combustion chamber which is connected to the at least one prechamber at least on the fuel side.

According to the invention, it is provided that an evaporator is arranged upstream of the at least one prechamber.

It is preferably provided that, in a first embodiment, an evaporator of the fuel supply system is arranged between a feed pump (Speisepumpe) for supplying fuel in the gaseous state only to the at least one prechamber and the at least one prechamber, wherein the fuel supply system further comprises a high-pressure pump for supplying fuel in the liquid state only to the at least one main combustion chamber.

In a second embodiment, it is preferably provided that the evaporator comprises a gas-state fuel supply between the high-pressure pump and the at least one prechamber for supplying the at least one prechamber with a gas-state fuel, wherein the high-pressure pump is also used for supplying the at least one main combustion chamber with a liquid-state fuel, so that a supply line to the evaporator branches off downstream of the high-pressure pump from a supply line to the at least one main combustion chamber.

In a number of possible preferred embodiments, it is provided according to the invention that the evaporator for evaporating the liquid fuel is provided with a heating device or is connected to a heating device for supplying heat.

In a preferred embodiment, it is provided that the evaporator is provided with a separate heating device.

In a further preferred embodiment, it is provided that the evaporator is coupled into a preheating device of the internal combustion engine for cold starting.

In a further preferred embodiment, it is provided that the evaporator is designed as a heat exchanger embodiment, wherein heat is removed from the cooling water of the internal combustion engine and supplied to the evaporator.

In a preferred embodiment variant, the fuel supply system is configured such that a control mixing valve (regelmschventoil) is arranged between the evaporator and the at least one prechamber, via which control mixing valve another gaseous fluid (in particular air) can be supplied to the gaseous fuel evaporated in the evaporator, so that the at least one prechamber can advantageously be supplied with unmixed gaseous fuel or fuel vapor/air mixture, optionally in a presettable mixing ratio.

The main aspect of the method according to the invention is that at least one prechamber of a gasoline-operated internal combustion engine is actively scavenged with gaseous fuel using the fuel supply system, wherein the internal combustion engine comprises at least one main combustion chamber which is connected to the at least one prechamber at least on the fuel side, wherein according to the invention it is provided that, before the fuel is supplied to the at least one prechamber, the liquid fuel is evaporated in an evaporator and supplied to this prechamber unmixed or mixed with air, which evaporator is arranged upstream of the at least one prechamber.

Drawings

The invention is explained below with the aid of the associated figures. Wherein:

fig. 1 shows schematically a fuel supply system for actively scavenging a prechamber of an internal combustion engine, in particular of the gasoline engine type, with fuel vapor or a fuel vapor/air mixture by means of a fuel evaporator upstream of the prechamber.

Detailed Description

According to the invention, FIG. 1 provides for each cylinder Z to be operated with a gaseous gasoline fuel pair_nArrangement of the fuel evaporator 11, which is actively scavenged by the prechamber 32 arranged therein, within the fuel supply system 100 of a gasoline internal combustion engine 30, via the connection to each cylinder Z_nAn associated transfer valve (Taktventil)13 beats the gaseous fuel K evaporated in the fuel evaporator 11 in a time-staggered manner_gasfIs blown into the respective prechamber 32.

According to the invention, the method is characterized in general by active scavenging of one or more prechambers 32, which scavenging according to the invention makes use of the gaseous fuel K evaporated in the fuel evaporator 11_gasfAnd (6) executing.

Gaseous fuel K_gasfWith each external ignition device 32A, it is actively ignited in the respective prechamber 32, as is likewise schematically illustrated in fig. 1.

For each cycle, the respective active prechamber 32 is supplied via the metronomic valve 13 with an ignition chamber (prechamber) charge that is ignited by means of the external ignition device 32A.

The main combustion chamber is then charged with gas by means of one or more reactive, burning gas jets (flames) which are generated in the respective prechamber 32 and which exit from the respective prechamber 32 into the main combustion chamber or main combustion chamber 31.

After the ignited ignition chamber (prechamber) charge is burnt out, the ignition chamber (prechamber) charge is resupplied and ignited, so that the residual gas present in the respective prechamber 32 is actively scavenged from the respective prechamber 32 into the main combustion chamber 31, wherein the previously described process is repeated accordingly during operation of the internal combustion engine 30.

The reactive, burning gas jet (flame) generated in the prechamber 32 by means of the ignition chamber (prechamber) charge thus enters the main combustion chamber 31 of the internal combustion engine 30 via at least one opening (not shown in detail in fig. 1) and ignites the main combustion charge supplied to the respective main combustion chamber 31.

To utilize gaseous fuel K_gasf(Fuel vapor) or Fuel vapor/air mixture K_gasf’The active prechamber 32 is purged according to the invention with liquid fuel K in the tank 1_flFor starting, the liquid fuel is preferably electrically heated by the motor cooling water (in the heat exchanger embodiment) or by a preheating device for cold start or a separate heating device for the fuel evaporator 11. The fuel evaporator 11 is supplied with liquid fuel K from the tank 1 via a supply line 10a (see fig. 1)_fl。

A corresponding heating device 11c in one of the above exemplary embodiments is schematically illustrated in fig. 1 and is designated by reference numeral 11 c.

In a first embodiment, the liquid fuel K is supplied by a supply pump 10_flIs supplied to the fuel evaporator 11, which according to the invention generates the required pressure level for the injection pressure of the ignition chamber (prechamber) charge.

Inside the fuel evaporator 11, the liquid fuel K_flEvaporated, thus in gaseous phase K_gasfIs present and is supplied via a supply line 10a to a takt valve 13 which is arranged upstream of the prechamber 32.

Fuel vapor K_gasfIs sucked off from the fuel evaporator 11 and, in a design variant, is supplied unmixed to the injection system of the fuel supply system 100, in particular to the clocked valve 13.

In a further embodiment variant, the fuel vapor K_gasfIs mixed with a gaseous fluid, in particular air, via a control mixing valve 12, so that an air-fuel vapor mixture K is formed_gasf’Wherein a regulating mixing valve 12 is arranged in the supply line 11a between the fuel evaporator 11 and the takt valve 13.

There are thus advantageously the following possibilities: depending on the design variant, pure fuel vapor K is introduced_gasfOr by means of a regulating mixing valve 12, to which in particular air is supplied via a supply line 11b_gasf’Is blown into the active prechamber or prechambers 32.

To make it possible toTo obtain fuel vapor K in the evaporator 11_gasfSo as not to become too lean in volatile components, a feedback valve (Rueckfuehrventil)14 is arranged in the feedback line 10b for supplying a predeterminable quantity of liquid fuel K_flFed back into the tank 1.

According to the illustration in the drawing, the feedback valve 14 can be configured as an overpressure valve or also as a clocked valve.

The main advantage of the described procedure and the described system is that the evaporator 100 is supplied with liquid fuel K, compared to the pressure level required for compressing the already gaseous fuel into the prechamber 32_flSignificantly less drive energy is required to supply the pump 10.

To scavenge the prechamber 32 at the moment of introducing the respective ignition chamber (prechamber) charge, the pressure required in the prechamber 32 must be higher than the main combustion chamber charge pressure in the main combustion chamber 31.

In a variant of the first embodiment, the feed pump 10 can also expediently take off the liquid fuel K before the high-pressure pump 20 of the fuel supply system 100, as opposed to as shown_flSo that the tank 1 does not require a separate interface (Anschluss) for the feed pump 10.

FIG. 1 shows, in addition, a high-pressure pump 20, a liquid fuel K_flFrom the tank 1, via the supply line 20a, by means of the high-pressure pump, the liquid fuel K is conducted via the injection valve 21 to the main combustion chamber 31 of the internal combustion engine 30, in order to obtain a liquid fuel K in the main combustion chamber 31_flReleasing or injecting one or more main combustion chamber charges.

According to FIG. 1, excess liquid fuel K_flIs returned to the tank 1 via a feedback line 20b, in which a quantity control valve 20c is arranged according to fig. 1.

In a second embodiment, it is possible for the liquid fuel K to be supplied to the fuel evaporator 11_flAccording to fig. 1, the high-pressure pump 20 is removed downstream via a supply line 20d, wherein the additional feed pump 10 can then be dispensed with.

In this embodiment variant according to fig. 1, a corresponding pressure control valve 20e is arranged in the supply line 20d, which correspondingly reduces the pressure of the high-pressure pump 20 to a predefinable evaporator pressure of the fuel evaporator 11, and thus reduces the pressure.

Fuel supply system 100 is configured to carry out the method according to the invention for scavenging the active prechamber of a gasoline engine with fuel vapor or a fuel vapor/air mixture by means of a fuel evaporator. For this purpose, the fuel supply system (100) comprises, in particular, at least one control device (motor controller) in which a computer-readable program algorithm for carrying out the method is stored and, if necessary, a required characteristic map. The control device controls and regulates the above-mentioned controllable and adjustable components.

The fuel supply system 100 according to the invention can be part of a fuel supply and ignition system used in combination with a gas combustion method with improved lean operation capability.

Liquid fuel K as fuel tank 1 for an internal combustion engine 30, in particular a gas internal combustion engine_flLiquefied natural gas is currently the focus. It is provided to construct a gas internal combustion engine with a prechamber 32 and a main combustion chamber 31 and to associate the gas internal combustion engine with a fuel supply system as explained above. In other words, the fuel supply system 100 and the method relate to liquid fuel K_fl(in particular liquid gasoline) and in the case of gas internal combustion engines, liquid gas (in particular natural gas) is stored in liquid form in the tank 1 of the fuel supply system 100.

It is known to use a pure gaseous fuel K_gasfThe ignition cavity (pre-combustion cavity) is charged with air to scavenge the pre-combustion cavity. The invention proposes a solution by means of an integrated fuel vaporizer 11, which, together with the stated components of the fuel supply system, ensures the provision of unmixed gaseous fuel or fuel vapor/air mixture K_gasf、K_gasf’To cause scavenging of one or more prechambers 32 inside fuel supply system 100.

List of reference numerals:

100 fuel supply system

1 oil tank

10 supply pump

10a supply line

10b feedback line

11 fuel evaporator

11a supply line

11b supply line

11c heating device

12-regulating mixing valve

13 beat valve

14 feedback valve

20 high pressure pump

20a supply line

20b feedback line

20c quantity control valve

20d supply line

20e quantity control valve

21 injection valve

30 internal combustion engine

Zn cylinder

31 main combustion chamber

32 precombustion chamber

32A external ignition device

K fuel

K_flLiquid fuel

K_gasfGaseous fuel

K_gasf’A fuel vapor/air mixture.