KR960008783B1 - Water-fuel injection apparatus for diesel engine - Google Patents

Abstract

None.

Description

Fuel and water injector of water injection diesel engine

1 to 6 are related to the first embodiment, Figure 1 is a block diagram of a water spray device.

2 is a longitudinal sectional view of a water and fuel switching valve.

3 is a cross-sectional view taken along the line III-III of FIG.

4 is a modification of the copper switching valve

5 is a cross-sectional view of the fuel injection valve.

6 is a diagram illustrating the operation of the embodiment.

7 to 9 show a conventional example.

7 is a corresponding view of FIG.

8 is a correspondence diagram of FIG.

9 is a diagram explaining the operation.

* Explanation of symbols for main parts of the drawings

40 fuel and water injection valve 13 check valve

16 control valve 31 confluence

21: injection charge 22: fuel passage

17: water supply pipe 117: fuel supply pipe

201: switching valve device

The present invention relates to a fuel and water injector for a water spray diesel engine.

As a means of reducing nitrogen oxides (NO _X ) in the exhaust gas of the diesel engine and at the same time reducing the exhaust gas smoke and fuel consumption rate of the engine, the conventional fuel and water shown in FIGS. Diesel engines capable of injecting fuel from the same fuel injection valve are valid.

In the drawings, reference numeral 1 denotes a fuel tank, 2 denotes a fuel supply pump, 3 denotes a fuel injection pump body, 4 denotes a copper plunger, 5 denotes a plunger barrel, and 6 denotes a discharge valve. 7) denotes a pressure regulating check valve provided in the shaft of the discharge valve 6, 8 denotes a fuel injection pipe, 4 denotes a fuel and water injection valve, 9 denotes the main body, and 10 denote injection holes. (11) is a needle valve, (12) is an oil sump part, (14) is a pressure spring of the needle valve (11).

19 is a water tank, 18 is a water supply pump, 17 is a water supply pipe, 16 is a water supply control valve, 15 is a water supply pipe, and 13 is a water supply check valve. Prevent backflow to the control valve. Further, reference numeral 20 denotes a control device for controlling the amount of water supplied and the timing of supply of water, and inputs an engine crank angle signal and other engine operating conditions, and outputs an open / close signal to the control valve 176 via a line 23. .

A fuel passage 22 is drilled through the main body 9 of the fuel / water injection valve 40 to communicate with the fuel injection pipe 8 and the fuel / water injection valve oil sump part 12. Similarly, the check valve 13 for water supply is connected to the confluence part 31 in the middle of the upper fuel passage 22 via the water passage 30 drilled through the main body of the fuel / water injection valve 40.

Next, the operation of the conventional example will be described.

The water pressurized by the water supply pump 18 from the water tank 19 is passed through the supply pipe 17 to the control valve 16, and the plunger 4 of the fuel injection pump 3 pumps the fuel. The control valve 16 is maintained in a valve open state for a predetermined period through a control device during the idle period which is not performed, and a predetermined amount of water is sent to the fuel / water injection valve 40 via the supply pipe 15. give. At this time, when the valve opening pressure P _R of the pressure regulating check valve 7 of the fuel injection pump 3 and the valve opening pressure of the check valve 13 for water supply are P _P as described above, the needle valve 11 is used. Valve opening pressure P _O

P _O P _R , P _O P _P

Therefore, the supplied water flows into the fuel passage 22 through the water passage 30 and the confluence portion 31 via the check valve 13.

The fuel upstream from the confluence part 31 in the fuel passage 22, that is, the fuel injection pump 3, is pushed back through the injection pipe 8 in the direction of the fuel injection pump 3 by the supply water pressure to adjust the pressure. The check valve 7 is pushed open to flow back to the plunger chamber.

As a result, as shown in FIG. 8, in the fuel / water injection valve 40, the volume V ₂ of the oil sump part 12 and the fuel passage 22 from the confluence part 31 to the oil sump part 12 are shown. The volume of V ₁ + V ₂ , which is the sum of the volumes V ₁ ), is filled with fuel, and a predetermined amount of water is filled in the fuel passage 22 upstream of the confluence unit 31, and again upstream of the fuel passage 22. The fuel is in a filled state.

Next, when the plunger 4 of the fuel injection pump 3 rises and compression of fuel starts, the pressure in the injection pipe 8, the fuel passage 22, and the oil sump part 12 rises, and the needle valve The needle valve 11 is opened when the valve opening pressure P ₀ is _{equal to} or _greater than. At this time, the water in the water passage 30 is not pushed back toward the water tank 19 by the action of the check valve 13.

When the needle valve 11 reaches the valve opening pressure P0, from the injection hole 10 of the fuel / water injection valve 40 of FIG. 9, the confluence part in the oil sump part 12 and the fuel passage 22 is first. Fuel of the volume of V ₁ + V ₂ filled in the volume up to is injected, water which has been supplied for a predetermined amount is injected, and finally, the remaining fuel is all injected. If the quantity of fuel injected by one injection is Q _F , the quantity of fuel first injected Q _FP becomes Q _FP = V ₁ + V ₂ as described above, and then the entire quantity of water of Q _W is injected, and finally If the remaining fuel is Q _FS , Q _FS = Q _F -Q _FP is injected.

As a result, the ignition of the initial stage of the diesel fuel stroke is surely performed by the fuel of Q _FP , _and the introduction of air into the spray is continuously increased by the water of Q _W , thereby increasing the fuel speed and reducing the black smoke generation. At the same time, reduction of NO _x is obtained by introduction of water into the flame zone.

However, in the above conventional technique, the reduction effect of NO _x in exhaust is obtained in approximately proportion to the injection amount Q _W of water, but if the Q _W is excessively increased with respect to the fuel amount Q _F , the initial Q _FP and the later Q Excessive time intervals between the fuel injections of the _FS cause combustion failures and prevent the engine from operating stably. For this reason, in order to further reduce the NO _X is means for increasing the water injection amount Q _W without accompanying the lack of combustion is necessary.

An object of the present invention is to solve the problems of the conventional apparatus, and water injection fuel is injected in a multi-layered form during water injection, so that even if the water supply amount of water is greatly increased, water injection diesel does not cause instability of combustion as in the prior art. To provide an engine.

Means according to the present invention include a fuel supply passage and a check valve communicating with a fuel injection pump in a water injection diesel engine for injecting fuel and water into a combustion chamber, and the fuel supply passage further upstream of the oil sump portion. A fuel injection valve having a fuel and mole supply path, a switching valve device for communicating with the fuel tank and the water tank separately and discharging fuel and water alternately and continuously, a discharge port of the switching valve device, and a fuel and water supply A control valve disposed between the inlet of the furnace and a control device for opening the control valve while the fuel injection pump is held, the fuel injection and water injection device of the water injection diesel engine characterized in that it comprises.

In the present invention, when the injection control valve 16 is opened during the rest of the fuel injection pump, the pressurized water and fuel are alternated by the water and fuel supply device and the water and fuel switching valve device 201, respectively. It flows into the injection path through the electronic control valve 16.

As a result, a multi-layered liquid column is formed in the injection furnace with water, fuel, water, and fuel. This multi-layer liquid column of water and fuel flows in through the confluence portion 31 formed in the fuel valve while the injection control current control valve 16 is open, and is upstream of the confluence portion in the fuel flow path, that is, the fuel injection pump. The fuel on the side is filled into the fuel flow path while pushing the pressure regulating check valve 7 provided on the fuel injection pump to open the fuel toward the fuel injection pump. At this time, the multi-layered liquid column of water-fuel formed in the injection path is filled while maintaining the multi-layered structure as it is, so that the multi-layered liquid column of the same water-fuel is preserved even in the fuel flow passage 22.

When the fuel injection pump is operated, this liquid column is injected from the injection hole via the needle valve of the fuel valve while maintaining its multilayer structure.

As a result, even if the water injection amount Q _W is greatly increased as compared with the conventional one, since the multi-layered water made of water and fuel is injected at the time of pouring, combustion destabilization can be avoided.

Therefore, an increase in water injection amount can be realized without causing unstable operation of the engine, and a significant effect of reducing NO _X in exhaust gas corresponding to an increase in water injection amount is obtained.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 9.

1 to 6 are related to an embodiment of the present invention, Figure 1 is a configuration of the water spray device, Figure 2 is a longitudinal cross-sectional view of the switching valve, Figure 3 is a cross-sectional view III-III of Figure 2, Figure 4 is a switch 5 is a cross-sectional view of the fuel injection valve, and FIG. 6 is an explanatory view of the operation.

(1)-(31) is the same as that of the prior art example (FIG. 7).

Reference numeral 118 denotes a fuel pressure pump, which sucks and pressurizes the fuel from the fuel tank 1 and passes it through the fuel supply pipe 117 to the switching valve device 201. On the other hand, the water pressurized by the water supply tank 18 is similarly led to the switching valve device 201 via the water supply pipe 17. A check valve is provided between the fuel supply pipe 117 and the water supply pipe 17 and the switching valve device 201 to allow only a flow from the fuel tank 1 and the water tank 19 toward the switching valve device 201. 203 and 204 are each excreted. 202 may be a drive device for driving the switching valve 201 or a drive device synchronized with the engine speed, or a constant-speed electric motor.

2 and 3 show a switching valve device 201, 211 and 212 are water or fuel supply ports and 210 are rotary valves, respectively. In this rotary valve, a water opening groove 214 and a fuel opening groove 215 are formed so that water and fuel are alternately sent to the supply pipe 213.

4 is a second modification of the switching valve device in which the control device 20 and the electromagnetic control valves 16 and 116 are combined. Numeral 16 denotes a water control valve, numeral 116 denotes a fuel control valve, which is installed in the water supply pipe 17 and the fuel supply pipe 117, respectively, and the fuel injection pump 3 is controlled by the controller 20 during the idle period. Alternately, opening and closing is controlled for a predetermined period.

Next, the operation of the above embodiment will be described.

2 and 3, when the control solenoid valve 16 is opened during the rest period of the fuel pump, pressurized water and fuel are introduced through the supply pipes 17 and 117, respectively. Inflow to 15 is made, but water and fuel flow in alternately from the control ports 211 and 212 corresponding to the respective opening periods by the action of the switching valve 201.

In the variation of the switching valve device of FIG. 4, the control valves 16 and 116 of water and fuel are alternately opened and closed controlled by the control device 20 during the rest period of the fuel injection pump 3, As in the case of the example, water and fuel flow into the injection pipe 15 alternately corresponding to the opening period. As a result, a liquid column in which water and fuel are alternately multilayered is formed in the injection pipe 15.

During the multi-layer liquid column injection period, the injection path 21, the check valve 13, and the confluence part 31 formed upstream from the oil sump part 12 are sequentially formed in the fuel injection valve body 9. The fuel is flowed into the fuel flow passage 22 while maintaining the multilayer structure, and the fuel upstream from the confluence portion 31 in the fuel flow passage, that is, the fuel injection pump 3, is regulated in the pressure injection pump 3. The check valve 7 is pushed open and returned to fill the fuel passage 22 with a multi-layered liquid column. At this time, the alternating multi-layered liquid column of water-fuel formed in the injection passage 21 is filled as it is while maintaining the multilayer structure, and thus, the fuel passage 22 has the fuel (white portion) as shown in FIG. Multi-layered liquid column is formed by alternating with water (black part) -fuel-water.

Next, when the fuel injection pump 3 operates to start injection, the fuel of the oil sump part 12 is opened by opening the needle valve 11, as shown in FIG. Water and fuel in the inject are alternately injected in a multi-layered form, and only the fuel is injected at the end, and this is repeated. For this reason, even if the amount of water required to reduce NO _x in the exhaust gas is increased, the rotation of the engine is not unstable.

According to the present invention, in the water injection diesel engine for injecting fuel and water from the same fuel injection valve, the fuel and water are injected in a multi-layered form instead of the conventional water injection. Therefore, the amount of water injected is greatly increased. Even if it does so, since fuel is inject | poured in a multilayer form in the middle, combustion will not become unstable.

As a result, the water injection amount can be increased without causing the combustion failure of the engine, and a significant reduction of NO _{X in} the exhaust gas can be obtained in response to the increase in the water injection amount.

Claims (1)

In a water injection diesel engine that injects fuel and water into the combustion chamber, a fuel supply path and a check valve in communication with the fuel injection pump are incorporated, and a fuel and water supply path joined upstream than the oil sump part in the fuel supply path. Branches have a fuel injection valve, a switching valve device which communicates separately with the fuel tank and the water tank and discharges fuel and water alternately and continuously, and a control disposed between the discharge port of the switching valve device and the inlet of the fuel / water supply passage. A valve and a control device for opening the control valve while the fuel injection pump is held, the fuel and water injector of the water injection diesel engine, characterized in that the.