JP2003232731A - Smoke measuring system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a smoke measuring system that can measure the relative discharge of smoke in an exhaust gas with accuracy in real time. <P>SOLUTION: A light transmittance measuring instrument 3 which measures the light transmittance of the exhaust gas G and a flow rate measuring instrument 4 which measures the flow rate of the gas G are installed to a pipeline 2 through which the exhaust gas G flows and the relative discharge of the smoke in the exhaust gas G is obtained based on the light transmittance obtained from the light transmittance measuring instrument 3 and the flow rate of the exhaust gas G obtained from the flow rate measuring instrument 4. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for measuring smoke (black smoke) contained in exhaust gas of an internal combustion engine.

[0002]

2. Description of the Related Art For example, in a diesel engine of an automobile, combustion progresses locally and unevenly, resulting in incomplete combustion in a portion where the amount of fuel (light oil) is large relative to the amount of air. As a result, soot that does not dissolve in the organic solvent is generated. When the liquid droplets of unburned fuel or lubricating oil adhere to the soot, the particulate matter (P
M) is generated. When a large amount of this PM is discharged from the tail pipe of the engine, not only is the air polluted, but it is clearly visible as smoke.

In order to measure the amount of smoke discharged, a so-called filter weight method has been mainly used in the past. That is, FIG. 5 shows an example of a PM collecting apparatus for carrying out the filter weight method. In this figure,
51 is an automobile diesel engine (hereinafter, simply referred to as an engine), 52 is an exhaust pipe connected to the engine 51,
Exhaust gas G flows. The exhaust pipe 52 has a downstream end 52.
a is inserted and connected to a diluting pipe (also referred to as a diluting tunnel) 53. The diluting pipe line 53 dilutes the entire amount of the exhaust gas G with the clean air A so that the flow rate of the flowing gas becomes a constant flow rate. Is formed, and on the downstream side, for example, CFV (Critical
Flow Venturi) 55 and suction pump 5
6 is provided so that the exhaust gas G from the engine 51 can flow at a constant flow rate. And
Reference numeral 57 denotes a gas sampling flow path connected at a point slightly upstream of the CFV 55 with respect to the diluting pipeline 53,
The probe 57a on the upstream side is inserted and connected in the diluting pipe line 53, and a part of the exhaust gas G diluted with the air A is sampled as the sample gas S. The gas sampling channel 57 is provided with a filter device 58 for collecting PM contained in the sample gas S.

Then, the PM in the exhaust gas G is collected by the filter body in the filter device 58 by using the PM collecting apparatus having the above-mentioned configuration, and the weight of the filter body before PM collection and the weight after PM collection are measured. Measured with and exhaust gas G
The amount of PM in it was quantified.

However, according to the above-mentioned conventional filter weight method, although the total weight of PM generated within a certain specific time can be obtained, the overall construction of the apparatus for collecting PM becomes large and the PM The filter device 58 needs to be removed from the gas sampling channel 57 to measure the weight, which is disadvantageous in that real-time continuous measurement cannot be performed.

As a method for solving the above-mentioned drawbacks of the filter weight method, for example, there is a measuring device disclosed in Japanese Patent Laid-Open No. 2000-161043. In the measuring device of this publication, a light transmittance measuring unit is provided in an exhaust pipe connected to an engine to obtain the absorbance of exhaust gas flowing in the exhaust pipe, while an engine rotational speed detecting unit is provided in the engine to measure the exhaust gas flow rate, and the Lambertian bale is measured. Is used to estimate the amount of smoke in the exhaust gas from the absorbance of the exhaust gas and the exhaust gas flow rate.

However, in the method disclosed in the above publication, the exhaust gas flow rate is obtained based on the engine speed, and this engine speed is not always constant, so an error occurs in the obtained exhaust gas flow rate value. In particular, EG
In the case of an R type (exhaust gas recirculation type) engine, the error becomes extremely large. That is, the above-mentioned publication has a drawback that smoke in exhaust gas cannot be accurately measured.

The present invention has been made in view of the above matters, and an object thereof is to provide a smoke measuring system capable of accurately measuring the relative amount of smoke emitted from exhaust gas in real time. .

[0009]

In order to achieve the above object, the smoke measuring system of the present invention comprises a light transmittance measuring device for measuring the light transmittance of the exhaust gas in a pipe through which the exhaust gas flows, and the exhaust gas of the exhaust gas. An exhaust gas flow rate measuring device for measuring a flow rate is provided to obtain the relative emission amount of smoke in the exhaust gas based on the light transmittance obtained from the light transmittance measuring device and the exhaust gas flow rate obtained from the exhaust gas flow rate measuring device. (Claim 1).

Further, in the smoke measuring system according to the first aspect, the light emitting portion and the light receiving portion of the light transmittance measuring device may be provided so as to respectively face the openings formed in the pipe so as to face each other. Good (Claim 2).

In the smoke measuring system having the above structure, the light transmittance of the exhaust gas flowing in the pipe is measured by the light transmittance measuring device, and the flow rate of the exhaust gas is measured by the exhaust gas flow measuring device. Since the relative emission amount of smoke in the exhaust gas is obtained based on the rate and the exhaust gas flow rate, the relative emission amount of smoke in the exhaust gas can be measured in real time and accurately.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The details of the present invention will be described below with reference to the drawings. 1 to 3 show one embodiment of the present invention. First, FIG. 1 schematically shows the basic configuration of a smoke measuring system of the present invention. Is a diesel engine (hereinafter simply referred to as an engine) of an automobile (not shown), and 2 is an exhaust pipe (an example of piping) connected to the engine 1. Reference numerals 3 and 4 denote a light transmittance measuring device and an exhaust gas flow rate measuring device provided in the exhaust pipe 2. In the illustrated example, the exhaust gas flow rate measuring device 4 is provided slightly upstream of the light transmittance measuring device 3. 5 is a smoke emission amount calculation device, which is a light transmittance measuring device 3 and an exhaust gas flow rate measuring device 4
The output of each is input and the smoke emission amount is calculated. Reference numeral 6 denotes a personal computer, which controls the entire smoke measuring system and performs necessary calculations based on the input from the smoke emission calculation device 5.

Next, an example of the configurations of the light transmittance measuring device 3 and the exhaust gas flow rate measuring device 4 will be described with reference to FIG. First, the structure of the light transmittance measuring device 3 will be described. The exhaust pipe 2 is, for example, circular in cross section, and two openings 7 and 8 are formed in the pipe wall 2a so as to face each other on one diameter. Has been done. Then, an LE that emits blue light (measurement light) having a wavelength of, for example, 560 nm outside the one opening 7 (outside the exhaust pipe 2) so as to face the opening 7.
A light emitting portion 9 made of D is provided, and a light receiving portion 10 is provided outside the other opening 8 so as to face the opening 8. The light receiving unit 10 is composed of a detector 10a such as a photo sensor and an optical filter 10b provided on the front surface of the light receiving side thereof for allowing only light of a specific wavelength to pass through. The light emitting unit 9 and the light receiving unit 10 allow a full flow type opacimeter. The light transmittance measuring device 3 is constructed. Then, in the light transmittance measuring device 3, the exhaust gas G from the engine 1 passing through the exhaust pipe 2 is irradiated with the measurement light from the light emitting section 9, and the exhaust gas G is output by the light receiving section 10 at that time. The light transmittance of can be measured.

Reference numerals 11 and 12 are fans provided so as to be located on the pipe wall 2a on the upstream side of the openings 7 and 8 (engine 1 side). These fans 11 and 12 are formed on the pipe wall 2a and the light emitting portion 9. And the air curtain 1 between the light receiving unit 10 and
3 and 14 are formed, and the exhaust pipe 2 is opened from the openings 7 and 8.
Exhaust gas G flowing out of the air is emitted from the light emitting unit 9 and the light receiving unit 10.
This is for prompt removal from the front side of the.

Next, the structure of the exhaust gas flow rate measuring device 4 will be described. The exhaust gas flow rate measuring device 4 is composed of, for example, a differential pressure type gas flow meter such as a Pitot tube, and is connected to the main body 15 and the main body 15. A first pressure detection pipe 16 that is inserted in the exhaust pipe 2 in its diameter direction and has a proper number of holes 16a of a proper diameter arranged side by side, and an exhaust pipe on a pipe wall 2a upstream of the first pressure detection pipe 16. The second pressure detection pipe 17 is provided so as to face the inside of the unit 2 and is connected to the main body unit 15. In the exhaust gas flow rate measuring device 4, an output corresponding to the sum of the dynamic pressure and the static pressure of the exhaust gas G flowing in the exhaust pipe 2 is obtained by the first pressure detection pipe 16, and the exhaust gas G by the second pressure detection pipe 17. An output equivalent to the static pressure of is obtained. Then, the dynamic pressure of the exhaust gas G is obtained by taking the difference between these two outputs, and the flow rate of the exhaust gas G is obtained by performing calculations based on this.

In the smoke measuring system having the above structure, the exhaust gas G from the engine 1 flows through the exhaust pipe 2 in the downstream direction, but when the exhaust gas G passes through the exhaust gas flow rate measuring device 4, the exhaust gas G is thereby generated. Is measured, and the measurement result is sequentially input to the smoke emission amount computing device 5. Then, when the exhaust gas G passes through the light transmittance measuring device 3 located on the downstream side of the exhaust gas flow measuring device 4, the light transmittance of the exhaust gas G is measured by this, and the measurement result is the smoke emission calculating device 5 Are sequentially input to. In the smoke emission amount calculation device 5, the relative emission amount of smoke in the exhaust gas G can be obtained by multiplying the sequentially input light transmittance of the exhaust gas G and the flow rate of the exhaust gas G by each other.

FIG. 3 shows the light transmittance of the exhaust gas G (the uppermost stage in the figure) and the flow rate of the exhaust gas G (the middle stage in the figure) obtained when the smoke measurement is performed on the engine exhaust gas G by the smoke measuring system. ) And the relative amount of smoke emitted (the lowest row in the figure).

As described above, according to the smoke measuring system of the present invention, the light transmittance of the exhaust gas G and the flow rate of the exhaust gas G can be measured continuously in real time.
By multiplying the light transmittance and the flow rate of the exhaust gas G with each other, the relative emission amount of smoke in the exhaust gas G can be continuously obtained in real time.

In the smoke measuring system shown in FIG. 2, the exhaust pipe 2 is provided with openings 7 and 8 and one of the openings 7 is provided.
In order to form the air curtains 13 and 14 along the open openings 7 and 8, since the light emitting section 9 is provided so as to face the other side and the light receiving section 10 is provided so as to face the other opening 8. Although the fans 11 and 12 of FIG.
As shown in FIG. 5, the optical windows 18 and 19 made of a material having a good light-transmitting property may be provided in the openings 7 and 8 by appropriate sealing members 20 and 21 to seal the openings 7 and 8.
In this case, the light emitting unit 9 and the light receiving unit 10 are connected to the optical window 18,
You may make it closely contact with 19.

Needless to say, the smoke measuring system shown in FIG. 4 has the same effects as the smoke measuring system shown in FIG. In the structure shown in FIG. 4, there is no possibility that the exhaust gas G will flow out through the openings 7 and 8 formed in the exhaust pipe 2,
Therefore, the light transmittance measuring device 3 can be installed at an arbitrary position of the exhaust pipe 2.

In the embodiments shown in FIGS. 2 and 4, the light transmittance measuring device 3 and the exhaust gas flow rate measuring device 4 are provided in the exhaust pipe 2 directly connected to the engine 1. Alternatively, another pipe may be connected in series to the exhaust pipe 2, and the light transmittance measuring device 3 and the exhaust gas flow rate measuring device 4 may be provided in this pipe. Also,
In the exhaust pipe 2 or the pipe, the light transmittance measuring device 3 may be provided on the upstream side of the exhaust gas flow rate measuring device 4.

The light emitting section 9 of the light transmittance measuring device 3 may be one that emits visible light, and the light receiving section 10 may be adapted to this.

Further, as the exhaust gas flow rate measuring device 4, a device for measuring the flow rate of the exhaust gas G using ultrasonic waves may be used.

In any of the above embodiments, the outputs of the light transmittance measuring device 3 and the exhaust gas flow rate measuring device 4 are input to the smoke emission amount calculating device 5 so that the smoke emission amount is calculated. However, the smoke emission amount calculation device 5 may be omitted, and the outputs of the measuring devices 3 and 4 may be input to the personal computer 6 to calculate the smoke emission amount.

Further, the engine 1 in each of the above-mentioned embodiments may be installed in a vehicle running on a road surface, or may be installed in a vehicle mounted on a chassis dynamo. It may exist, or may be a single engine mounted on the engine dynamo. In particular, when the smoke measuring system of the present invention is mounted on an automobile running on a road surface, the amount of smoke emitted during actual running can be measured in real time.

The smoke measuring system of the present invention can be used not only for measuring smoke in engine exhaust gas of automobiles described above, but also for measuring smoke in exhaust gas discharged from other combustion engines such as boilers. By providing the light transmittance measuring device 3 and the exhaust gas flow rate measuring device 4 in the flue, the relative amount of smoke contained in the exhaust gas G from the boiler can be obtained.

[0027]

As described above, according to the smoke measuring system of the present invention, the relative amount of smoke emitted from exhaust gas discharged from various combustion devices such as automobile engines and boilers can be accurately measured in real time. be able to.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a basic configuration of a smoke measuring system of the present invention.

FIG. 2 is a diagram showing an example of a configuration of a main part of the smoke measurement system.

FIG. 3 is a diagram for explaining the operation of the smoke measuring system.

FIG. 4 is a diagram showing another example of a configuration of a main part of the smoke measurement system.

FIG. 5 is a diagram for explaining a conventional technique.

[Explanation of symbols]

2 ... Piping, 3 ... Light transmittance measuring device, 4 ... Exhaust gas flow rate measuring device, 7, 8 ... Opening, 9 ... Light emitting part, 10 ... Light receiving part, G ...
Exhaust gas.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01F 1/46 G01F 1/46 3G090 G01N 21/05 G01N 21/05 3G091 F term (reference) 2F030 CC20 2G057 AA01 AB01 AB06 AC03 BA05 2G059 AA02 BB01 CC19 DD12 EE01 FF04 GG02 HH02 HH06 JJ02 KK01 MM01 3G004 AA01 BA06 DA25 FA04 3G084 AA01 DA04 FA28 3G090 DA02 DA09 DA10 3G091 AA18 AA28 BA31 BA39 EA33 EA21 EA21 EA21

Claims (2)

[Claims] 1. A pipe in which exhaust gas flows inside is provided with a light transmittance measuring device for measuring a light transmittance of the exhaust gas and an exhaust gas flow measuring device for measuring a flow rate of the exhaust gas. A smoke measuring system, characterized in that a relative emission amount of smoke in the exhaust gas is obtained based on the obtained light transmittance and the exhaust gas flow rate obtained from the exhaust gas flow rate measuring device. 2. The smoke measuring system according to claim 1, wherein the light emitting portion and the light receiving portion of the light transmittance measuring device are provided so as to respectively face openings formed in the pipe so as to face each other.