JPH0532766U - Combustion device for a diesel engine - Google Patents

Abstract

(57) [Summary] [Purpose] Diesel engine combustion that can achieve stable combustion even during emulsion combustion with an increased water mixing ratio, and can achieve excellent combustion with significantly low NO _x , low smoke emission, and high combustion efficiency. To provide the equipment. [Constitution] In a conventional emulsion fuel diesel engine, a fuel valve for pilot-injecting a small amount of fuel with good ignitability is provided, and a flame due to pilot fuel is generated near the emulsion fuel valve nozzle shortly before the injection of emulsion fuel from the emulsion fuel valve. Its characteristic is that it is formed into a.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a combustion device of an internal combustion engine, especially a diesel engine that performs compression ignition combustion.

[0002]

[Prior Art]

 FIG. 4 shows the structure of a conventional emulsion fuel injection diesel engine. In the figure, 1 is a piston, 2 is a combustion chamber, 3 is an emulsion fuel injection valve, 4 is a cylinder head, 5 is a cylinder liner, 6 is an emulsion fuel spray, 7 is an emulsion fuel injection pump, 8 is an emulsion manufacturing device, and 9 is an emulsion manufacturing device. Is a water tank, 10 is an oil fuel tank, and SW is a swirl. In FIG. 4, the water and oil fuels respectively flowing out from both tanks 9 and 10 are mixed in the emulsion fuel production apparatus 8 to form an emulsion, and the emulsion fuel is supplied from the fuel injection valve 3 through the fuel injection valve 3 to the piston 1 In the vicinity of the top dead center, is adiabatically compressed in the combustion chamber 2 and injected into the high-temperature and high-pressure air, where it self-ignites and burns.

At this time, if the amount of emulsion fuel is appropriate, the momentum of the fuel spray 6 increases as much as water is mixed into the fuel, as compared with the case where only ordinary oil fuel is injected and burned. and as penetration of the fuel spray 6 with mixing of air is promoted to increase, the less favorable combustion properties of NO _X produced the temperature is reduced the higher the flue gas concentration is low also combustion zone the combustion efficiency can be obtained It has become.

[0004]

[Problems to be solved by the device]

But its combustion efficiency as indicated by a broken line in FIG. 3 as the mixing ratio of water in the conventional apparatus the fuel is increased by increasing, although NO _X and flue gas concentration decreases, the temperature at the ignition time of fuels sprayed area Since it decreases due to the increase in heat capacity due to water evaporation and water mixing, it is disadvantageous for ignition, the so-called ignition delay becomes longer, the pressure rise rate due to the rapid combustion of the combustible mixture during ignition increases, and noise increases. If the mixing ratio of water increases as the amount of water increases, the ignition itself may become unstable and the operation of the engine may become impossible.

The object of the present invention is to solve the above-mentioned problems of the conventional device, and to obtain stable combustion even in the case of emulsion combustion in which the water mixing ratio is increased, resulting in significantly low NO _x , low smoke emission, and high combustion. (EN) It is an object to provide a combustion device for a diesel engine, which can obtain highly efficient combustion.

[0006]

[Means for Solving the Problems]

 The diesel engine combustion device of the present invention is a diesel engine equipped with an emulsion fuel injection valve for injecting an emulsion fuel, which is a mixture of oil fuel and water, into a cylinder. It is characterized by including an oil fuel injection valve that injects the oil fuel and the oil fuel sent from the injection pump into the cylinder earlier than the start of the injection.

[0007]

[Action]

 With the structure of the present invention, a small amount of ordinary oil fuel having a high cetane number and good ignitability is pilot-injected into the cylinder prior to the injection of emulsion fuel, and a small amount of flame is generated near the nozzle tip of the emulsion injection valve. Since it is formed, the ignition of the emulsion fuel spray can be accelerated and the ignition can be reliably performed. The pilot oil fuel supply system is designed to take out a part of it from the oil fuel tank for emulsion fuel production. The amount of oil fuel is about 1/10 of the amount of oil fuel in emulsion fuel and is small. Since the fuel injection pump is sufficient in time, the structure of the device is extremely simple and can be manufactured at low cost.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. 1 is a block diagram of an emulsion fuel injection diesel engine with pilot injection according to the first embodiment of the present invention, FIG. 2 is a relationship diagram of crank angle and needle valve lift of the first embodiment, and FIG. 3 is a performance of emulsion combustion engine. It is a curve figure.

In the figure, 1 is a piston, 2 is a combustion chamber, 3 is an emulsion fuel injection valve, 4 is a cylinder head, 5 is a cylinder liner, 6 is an emulsion fuel spray, 7 is an emulsion fuel injection pump, and 8 is an emulsion. Fuel production device, 9 is a water tank, 10 is an oil fuel tank, SW is a swirl, 11 is an oil fuel injection valve, 12 is an oil fuel spray, 13 is an oil fuel injection pump, 14 is an oil fuel pipe, and 15 is an oil fuel injection. Shows a tube.

The emulsion fuel manufacturing apparatus manufactures an emulsion fuel by supplying a required ratio of fuel and water from the oil fuel tank 10 and the water tank 9. The emulsion fuel is injected into the combustion chamber 2 through the emulsion fuel injection pump and the emulsion fuel injection valve 3. These parts are exactly the same as the conventional example, but in the embodiment of the present invention, when the injection of the emulsion fuel from the emulsion fuel valve 3 is started earlier, the oil fuel from the oil fuel tank 10 is partially removed as shown in FIG. The small fuel oil injection pump 13 takes out and fuel oil having good ignitability is pilot-injected from the fuel oil injection valve 11 to form the fuel oil spray 12 in the combustion chamber 2. As a result, the ignitability of the emulsion combustion engine is improved and a high performance emulsion combustion engine as shown in FIG. 3 can be realized.

[0011]

[Effect of the device]

Since the present invention is configured as described above and pilot-injects oil fuel to the conventional emulsion combustion diesel engine due to its ignitability, it is possible to accelerate the ignition of emulsion fuel injection fog and has a relatively simple structure. Moreover, it is easy to handle, and stable ignition combustion can be obtained even when the water mixing ratio is increased, and as shown in FIG. 3, a significantly low NO _x , low smoke emission, and high combustion efficiency and good combustion can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an emulsion fuel injection diesel engine with pilot injection according to a first embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the crank angle and the needle valve lift of the engine.

FIG. 3 is a performance explanatory diagram of the pilot injection emulsion engine of the present invention.

FIG. 4 is an illustration of the conventional device in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piltun, 2 ... Combustion chamber, 3 ... Emulsion fuel injection valve, 6 ... Emulsion fuel spray, 7 ... Emulsion fuel injection pump, 8 ... Emulsion fuel manufacturing device, 9 ... Water tank, 10 ... Oil fuel tank, 11 ... Oil Fuel injection valve, 12
... oil fuel spray, 13 ... oil fuel injection pump.

Claims (1)

[Scope of utility model registration request] 1. In a diesel engine equipped with an emulsion fuel injection valve for injecting an emulsion fuel, which is a mixture of oil fuel and water, into a cylinder, rather than a fuel injection pump for injecting a small amount of oil fuel and starting the injection of emulsion fuel. A combustion device for a diesel engine, comprising: an oil fuel injection valve for injecting the oil fuel fed from the oil fuel injection pump into the cylinder at an early stage.