RU2222806C1 - Toxicity indicator of exhaust gases of car diesel engine - Google Patents

Abstract

FIELD: systems controlling fuel supply of car diesel engines. SUBSTANCE: toxicity indicator can be utilized in systems controlling fuel supply of car diesel engines as element of feedback to execute controlling action on quality of working fuel and air mixture and on moment of its injection into combustion chamber and in systems of autonomous ecological monitoring of car diesel engines. Indicator has filter, two isolated electrodes placed in measurement resistor bridge and fabricated from passive ( not capable of reaction ) metal or alloy and presenting plates in the form of hollow semi-cylinders with thin layer of catalyst applied on to concave surface of one of them and filter of cyclone type with certain geometric proportions of elements which outlet branch pipe communicates with electrodes positioned coaxially to it. It comes in the form of tube with plugged upper part, holes drilled in upper part in horizontal plane at angle with side surface of tube and located in zone of concave surface of electrodes. EFFECT: toxicity indicator provides opportunity to obtain information of harmful effect of exhaust gases on men and animals by increase of informativity of measured value of solid particles ( soot ) with diameter under 10 mcm with reference to toxicity of exhaust. 2 cl, 2 dwg

Description

 An automotive diesel exhaust toxicity sensor can be used in automotive diesel fuel management systems as an element of a feedback unit. Using the signal from the sensor, it is possible to exert a control effect on the quality of the working air-fuel mixture and the moment of its injection into the combustion chamber (i.e., to change the coefficient of excess air and the angle of advance of the injection). The sensor can also be used in autonomous environmental monitoring systems for automotive diesel engines to obtain continuous information on exhaust toxicity.

 A known sensor consisting of an insulated support in which two electrodes are located [1].

 The disadvantage of this sensor is the lack of a clear relationship between the sensor signal and the toxicity of exhaust gases, since it registers a value that correlates with the concentration of solid particles over the entire dispersion range, while particles with a size of about 10 microns or less are harmful.

 The objective of the invention is the ability to obtain information about the harmful effects of exhaust gases of a diesel engine on humans and animals. The solution to this problem is realized by increasing the information content of the measured value of the sensor of the content of solid particles (soot) in relation to exhaust toxicity, that is, by increasing the correlation of the signal from the sensor of the content of solid particles (soot) with the toxicity of diesel exhaust. So, in the exhaust of an automobile diesel, soot particles have a wide range of dispersion (0.3 ... 100 microns), however, particles less than 10 microns in diameter are most harmful to humans and animals.

This task is achieved by the fact that the invention contains two electrodes isolated from each other, which are plates in the form of hollow half cylinders with a thin catalyst layer deposited on the concave surface of one of them, and a cyclone filter, the outlet pipe of which communicates with the coaxially arranged with it electrodes and is made in the form of a pipe with a damped upper part and drilled in the upper part in a horizontal plane at an angle to the side surface of the pipe with holes located in the region ognutoy electrode surface. The geometric parameters of the components of the "cyclone" are determined by the relations:
a: b≈1: 2,
a: D: NTs ≈ 1: 6.5: 15,
D: B: N _to ≈1.25: 1: 1,
where a is the height of the inlet section of the inlet pipe, mm;
b is the width of the inlet section of the inlet pipe, mm;
D is the diameter of the cylindrical part, mm;
N _c - the length of the cylindrical part, mm;
In - the smaller diameter of the conical part, mm;
N _to - the length of the conical part, mm

 In addition, the electrodes are made of a passive (non-reactive) metal or alloy and are included in the measuring resistor bridge.

 In FIG. 1 is a perspective view of an exhaust gas toxicity sensor of an automobile diesel engine. Figure 2 is a horizontal section of an exhaust gas toxicity sensor of an automobile diesel engine along the axis of the holes drilled in the upper part of the cyclone outlet pipe.

The sensor contains a filter of the type "cyclone" 1 with input 2 and output 3 nozzles (figure 1). The output pipe 3 is a pipe with a blanked upper part and drilled in the upper part in a horizontal plane at an angle to the side surface of the pipe holes (figure 2). In addition, the sensor contains two electrodes isolated from each other, which are plates in the form of hollow half-cylinders 4 and 5, mounted coaxially to the outlet pipe of the “cyclone” 3. Plates 4 and 5 are made of a passive (non-reactive) metal or alloy, while a concave surface of the plate 4 is coated with a thin catalyst layer. Plates 4 and 5 are included in the resistor bridge, which also contains resistors R ₁ , R ₂ and a galvanometer.

 The operation of the proposed sensor is as follows.

From the engine exhaust tract, exhaust gases through the inlet pipe 2 at a high speed tangentially enter the working cavity of the “cyclone" 1. The exhaust stream is twisted, and soot particles with a diameter of about 10 microns or more contained in the stream are rejected to the walls under the action of the emerging centrifugal force and poured through an opening in the lower part of the cyclone body 1. A stream of exhaust gases, purified from particles of about 10 microns or more, entering through the side holes in the upper part of the outlet pipe 3, washes the surface of the plate stins 4 and 5. Soot particles less than 10 microns are oxidized on the plate 4, increasing its temperature and, therefore, internal resistance. Elimination of side factors acting on the signal from the plate 4 is achieved by including it in the resistor bridge, which also contains the plate 5, which is in the same conditions and does not react with soot particles, resistors R ₁ , R ₂ and a galvanometer detecting the difference of the internal resistance of the plates 4 and 5.

Sources of information
1. Hua Xiangyang, Zeng Mancheng // Neizhanisi Gongcheng, Chin. Intern. Combust Enging Eng. - 1990. - 11, 2. - S. 23-26.

Claims (3)

1. An exhaust gas toxicity sensor for an automobile diesel engine, comprising two electrodes isolated from each other, characterized in that it includes a cyclone filter, the outlet pipe of which communicates with the electrodes aligned with it, which are hollow half-cylinder plates coated with on the concave surface of one of them with a thin layer of catalyst, and made in the form of a pipe with a blanked upper part and drilled in the upper part in a horizontal plane at an angle to the side surface of have openings ranging in the area of the concave surface of the electrodes, wherein the geometric parameters of parts "cyclone" are defined by the relations a: b≈1: 2, a: D: N _c ≈1: 6.5: 15, D: B: N _to ≈1.25: 1: 1, where a is the height of the inlet section of the inlet pipe, mm; b - width of the inlet section of the inlet pipe, mm; D is the diameter of the cylindrical part, mm; N _c - the length of the cylindrical part, mm; In - the smaller diameter of the conical part, mm; N _to - the length of the conical part, mm 2. The sensor according to claim 1, characterized in that the electrodes are made of a passive metal or alloy. 3. The sensor according to claim 1, characterized in that the electrodes are included in the measuring resistor bridge.

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