JPS608410A - Diesel particulate combustor - Google Patents

Abstract

PURPOSE:To make it possible to carry out stable combustion with less amount of fuel, by providing such an arrangement that a primary air passage is formed in the outer periphery of a fuel injection port provided with a fine pipe, and the combustor has an inside and outside double shell structure having a space in which secondary and ternary air passages are formed. CONSTITUTION:A fine pipe 103 is provided to the jet port 101 of a fuel injection valve, and a primary air passage is formed in the outer periphery of the jet port 101. The combustor is formed in an inside and outside double-shell structure, and secondary and ternary air passages 153, 154 are formed in a space between inner and outer cylinders 151, 152. The wall surface of the inside cylinder 151 in the vicinity of the jet port 101 is formed as an inclined wall surface having a spreading angle corresponding to the injection angle of fuel. Secondary air communication holes 155 are formed in this inclined wall surface, and ternary air communication holes 156 are formed in the outlet wall surface of the inner cylinder 151.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a particulate combustor for a diesel engine.

A conventional combustor of this type is shown in FIG.

In the figure, 1 is an engine, 2 is an exhaust manifold, 3 is a connecting pipe, 4 is a diesel particulate filter, 5 is an exhaust pipe, 6 is a pressure sensor, 7 is a control device,
8 is a temperature sensor, 9 is a combustor, lO is a fuel injection valve, and this injection valve 1° has a primary air pipe 11 and a fuel supply pipe 12.
It is equipped with 13 is a secondary air pipe and a 14Fi spark plug. Figures 2 and 3 are detailed views of the combustor 9.
1 is a combustion tube, 92 is a swirler 194 having a swirling chamber 93 for secondary air, a secondary air hole is formed in the wall of the combustion tube 91, and 95 is a flange of the combustion tube 91, which connects the above-mentioned connection. Attached to pipe 3.

The fuel injection valve 1o has a rod 104 provided with a fuel injection passage 103 inserted into a valve body 102 having an injection port 101.
A primary air passage 105 is formed around the outer periphery of this passage 103. 106 is a fuel nipple, and 107 is an air supply nipple.

Next, the operation will be explained. Diesel vaticulates (floating substances) discharged from the engine 1 pass through the exhaust manifold 2, the connecting pipe 3, and the filter 4.
It is supplemented by. The purified exhaust gas is then released into the atmosphere through the exhaust pipe 5.

As the collection of particulates progresses, the exhaust pressure increases, and when a predetermined exhaust pressure is reached, the control device 7 starts combustion in the combustor 9. That is, a mixture of fuel and air sent by a pump (not shown) is injected into the combustion tube 91 and ignited by the spark plug 14.

This combustion burns the particulates collected in the filter 4 and regenerates the filter. Note that when the regeneration of the filter 4 is completed, the exhaust pressure decreases and the combustor 9 stops.

The conventional combustor configured as above has an unusual shape,
In addition, a large amount of fuel is required, and the amount of heat generated is high, causing an increase in temperature within the engine compartment, which adversely affects peripheral equipment and reduces engine fuel efficiency. Another drawback was that the high combustion heat caused damage to the filter material.

This invention was made to eliminate the above-mentioned drawbacks of the conventional ones, and it is possible to perform stable combustion with less fuel, and to make it smaller, eliminate the influence of temperature rise on peripheral equipment, and improve fuel efficiency. The purpose of the present invention is to provide a diesel particulate combustor that can

An embodiment of the present invention will be described below with reference to the drawings.

4 and 5, the fuel injection valve 10 is the same as the conventional one, except that the fuel injection passage 103 is made of a fine tube. 15 is the combustor, 2 inside and outside
It consists of heavy combustion cylinders 151 and 152, and a secondary air passage 153 and a tertiary air passage 154 are formed in the space between the inner and outer cylinders. The wall surface of the inner cylinder 151 near the injection port 101 has an inclined surface with a spreading angle commensurate with the fuel injection angle,
A secondary air hole 155 is provided on this inclined surface, and a tertiary air hole 156 is provided on the outlet wall of the cylinder 151.

Next, the operation will be explained. Fuel is supplied from the fuel nipple 106 of the injection valve 10, and the air nipple 107
When the primary air is compressed and sent by a pump etc. from the injection port 1
01, a mixture of fuel and air is injected into the inner cylinder 151, and the fuel is atomized.

The following equation is known as the atomization condition. The average particle size d in fuel atomization is given by:

where d = particle size (μm), vr = relative velocity of fuel and air n1/8, a - surface tension of fuel < dym/c1n),
ρL = citrusiness (t/cti), μt = viscosity (Poise
), Qt - volumetric flow rate of fuel (shih), and Qp - volumetric flow rate of air (ginhe).

When the atomized mixture is ignited by the spark plug 14,
The secondary air fed through the through hole 155 causes combustion.

At this time, the air-fuel mixture is diffused by secondary air until it adheres to the inner cylinder 151, and the fuel and air are mixed to reach a high temperature and are completely combusted. In addition, since the combustor is small, the inner cylinder 151 becomes high temperature due to combustion heat, but the air flowing through the flow path 153 between the inner cylinder 151 and the outer cylinder 152 and the tertiary air flow path 154 near the outlet ( The inner cylinder 151 is cooled by the ticulated combustion air.

On the other hand, the tertiary air sent from the through hole 156 is warmed by heat exchange with the inner cylinder 151, dispersed, and sent into the inner cylinder, where it is heated by a flame that completely burns and removes the particulates attached to the filter 4. Burn.

In the embodiment, the air for ticulated combustion is supplied from the outlet of the inner cylinder 151, but it may be returned to a part of the outer cylinder 152. In addition, the inner cylinder 151 can perform the same operation as described above even if no inclined surface is provided. Furthermore, in the explanation of this invention, the example of a diesel engine was described, but it can be widely applied to other engines.As described above, according to this invention, a fine pipe is used in the injection port of the fuel injection valve, and the combustion cylinder is divided into two parts, the inside and outside. The structure was restructured to form a secondary air flow path and a tertiary air flow path between both cylinders, as well as a secondary air hole near the injection port of the inner cylinder and a tertiary air passage on the outlet wall of the inner cylinder. The provision of air vents allows for stable combustion with less fuel, and the compact size eliminates the effects of temperature rise on peripheral equipment, improving fuel efficiency. Furthermore, it has the effect of reducing heat dissipation to the outside, resulting in a combustor that does not damage the filter due to high temperatures.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a diesel particulate filter regeneration device, Figure 2 is a partially cutaway cross-sectional view of a conventional combustor, and Figure 3 is a diagram of a diesel particulate filter regeneration device.
4 is a partially broken sectional view of a combustor according to the present invention, and FIG. 5 is a longitudinal sectional view of the same. 10...Fuel injection valve, 15...Combustor, 151...
- Inner cylinder, 152... Outer cylinder, 153... Secondary air flow path, 154... Tertiary air flow path, 155... Secondary air hole, 156... Tertiary air vents. In addition, in the figures, the same reference numerals indicate the same or equivalent parts 0 Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A fine tube is used for the injection port of the fuel injection valve, and a passage for primary air is provided around the outer periphery of the injection port. In addition to forming a flow path for secondary air and a flow path for tertiary air, the wall surface near the injection port of the inner cylinder is formed into an inclined surface with a widening angle commensurate with the injection angle of the fuel. A diesel particulate combustor characterized in that a secondary air passage is provided in the inner cylinder, and a tertiary air passage is provided in the outlet wall of the inner cylinder.