KR100389594B1 - Heated, light-extinction type diesel smoke meter - Google Patents

Abstract

LIGHT-EXTINCTION TYPE DIESEL SMOKE METER or DIESEL OPACITY METER is a device to measure the opacity of gas in real time by transmitting light through gas containing soot. It is a device consisting of a measuring chamber wound with a heater, an optical unit including a light emitting unit and a light receiving unit, a fan and a flow path for preventing pollution air, a microcontroller, a measurement value indicating unit, and a print.

Conventional diesel light permeation smoke detectors, which measure the concentration of soot emitted from diesel engines, produce two problems when the test is carried out in sub-zero outside air. The first problem is that water in the exhaust gas condenses into water inside the sampling line through which the diesel exhaust gas passes. The second problem is that fog is formed by cooling water vapor in the exhaust gas when cold anti-pollution air and hot exhaust gas supplied to prevent contamination of the lens collide in front of the optical lens.

In the present invention, in order to overcome the above disadvantages, by installing a heater and a temperature sensor in the sampling line of the conventional diesel light transmission type soot gas meter to be able to control and heat the feedback to a constant temperature. This prevented the formation of condensate on the sampling line when tested under sub-zero ambient conditions. In addition, a heater and a temperature sensor were installed in the flow path of the anti-pollution air and heated to a constant temperature by feedback control. This eliminates the phenomenon of fog when cold pollution air and exhaust gas collide.

Heated diesel light transmission smoke meter of the present invention (HEATED, LIGHT-EXTINCTION TYPE DIESEL SMOKE METER),

A sampling probe 14 inserted at the end of the exhaust pipe for measuring the soot concentration in the exhaust gas discharged from the diesel engine,

Heater 16 and a temperature sensor 17 are installed in the sampling line 15 of the light transmission type soot measuring instrument coupled to the outlet of the sampling probe 14 to enable heating to a constant temperature to prevent the generation of condensate. Sampling line,

A measurement chamber 18 through which the exhaust gas and the light beam connected to the outlet of the sampling line 15 pass,

An optical unit including a light emitting unit 20 and a light receiving unit 21 for measuring soot concentration by an optical method;

The heating type pollution of the present invention, in which a heater and a temperature sensor 23 are additionally installed in a mechanism 22 or a flow path for supplying anti-pollution air, thereby preventing the formation of mist generated when the exhaust gas and the anti-pollution air collide. Prevent air supply mechanism,

Interface and control the light source and the optical sensor of the optical unit, control the heater 16 installed in the sampling line 15 to a constant temperature, and control the heater 23 installed in the anti-pollution air supply mechanism to a constant temperature, pollution prevention And a microcontroller 24 which controls the fan 22 for supplying air, controls the heater 19 surrounding the measurement chamber at a constant temperature, and converts the concentration of the soot using the measured electrical value. ,

And a measurement value indicating unit 25 for presenting the measured soot concentration to the tester.

Description

Heated Diesel Light Transmission Smoke Meter {HEATED, LIGHT-EXTINCTION TYPE DIESEL SMOKE METER}

Since the early 1990s, North America and Europe have developed light transmission smoke detectors as standard measuring equipment and applied them to various diesel smoke regulations in order to improve the reliability of filter smoke detectors and the occurrence of large measurement errors. Light transmission type smoke measuring device is used as basic equipment to measure and regulate the concentration of smoke emitted from all vehicles equipped with diesel engine, and smoke of gas discharged from the chimney of diesel and petroleum boiler and power plant. It is also used to measure the concentration.

In Korea, after a pilot operation period of about three years, a diesel light smoke detector was first introduced as a standard equipment in May 2002 for the detailed inspection of operating vehicles conducted by the Ministry of Environment for aging vehicles in the metropolitan area. Currently, diesel light transmission smoke detectors produced around the world have been developed to be tested at more than 5 degrees of image, but the Ministry of Environment requires that the test be carried out at outside temperatures of minus 10 degrees. Detailed inspections of driving vehicles are presented in the Ministry of Environment's Air Quality Preservation Act, the Air Quality Preservation Act, and the National Institute of Environmental Research. Therefore, overseas products show problems that cannot be used in sub-zero weather, and the present invention has been devised to overcome these difficulties.

In Fig. 1, the sampling probe 2, the sampling line 3, the measurement chamber 4, the optical sections 6 and 9, the fan 10 for supplying anti-pollution air and the flow path, the microcontroller 11, the measured value indicating section (12), and a schematic configuration diagram of a conventional diesel light transmission soot measuring instrument (hereinafter referred to as 'a conventional measuring instrument') composed of a print and the like is shown. Exhaust gas from the inlet of the sampling probe (2; SAMPLING PROBE) inserted into the exhaust pipe end (1) of the diesel engine or vehicle flows into the center of the measuring chamber (4; MEASURING CHAMBER) via the sampling line (3). do. The soot-containing exhaust gas flows out into the outside air through the outlets at both ends of the measurement chamber. At this time, the light beam irradiated from the light emitting unit 6 (LIGHT TRANSMITTER) of the optical unit reaches the light receiving unit 9 (LIGHT RECEIVER) after passing through the exhaust gas and is detected as an electrical signal proportional to the amount of light. Light rays passing through the exhaust gas are absorbed or scattered by the soot in the exhaust gas, and only the remaining amount reaches the light receiving portion 9. This amount decreases in proportion to the concentration of soot, so it has been adopted as a quantitative method for measuring soot concentration. The technical content of this is described in detail in ISO 11614 (ISO 11614-APPARATUS FOR THE MEASUREMENT OF THE OPACITY AND FOR DETERMINATION OF THE LIGHT ABSORPTION COEFFICIENT OF THE EXHAUST GAS). One side of the convex lens 7, which produces parallel rays in the light emitting unit 6, and one side of the convex lens 8, which has a light condensing function in the light receiving unit 9, may be exposed to and contaminated. When the lens is contaminated, the irradiated light and the amount of light reaching the light receiving part are changed and measured differently from the actual soot concentration. Therefore, using a fan (FAN) or other equipment, the air pollution (PROTECTION AIR, or AIR CURTAIN) is changed to the lens ( 7,8) The structure is designed to prevent contamination by feeding in the future. Therefore, supply of anti-pollution air is essential and all conventional measuring instruments are equipped with a fan for supply of anti-pollution air. The measurement chamber 4 into which the exhaust gas flows is equipped with a heater and a thermocouple 5 to heat the measurement chamber outer wall to a constant temperature of 80 degrees Celsius or more in order to prevent condensation of moisture. The microcontroller 11 controls soot concentration through the control of the fan 10 for pollution prevention air supply, the control of the heater 5 wrapping the outer wall of the measurement chamber 4, the control of the optical elements of the optics 6 and 9, and the interface. Provides the ability to measure in real time.

Since the conventional measuring instruments of FIG. 1 are all developed and marketed for use only at a temperature of 5 degrees or more of an image, there is a disadvantage that they cannot be used in sub-zero outside air. The first reason is that excessively condensation of moisture occurs in the sampling line 3 exposed to sub-zero outside air conditions while the exhaust gas flows into the measurement chamber 4 along the sampling line 3. This is because the condensed water is pushed into the measurement chamber 4 to contaminate the lenses 7 and 8 of the light emitting portion 6 and the light receiving portion 9. If the lenses 7 and 8 are contaminated by condensate, soot is adsorbed on it, making continuous and continuous measurement impossible. For the second reason, when the test is carried out in sub-zero ambient conditions, sub-zero cold air is supplied as anti-pollution air. In Fig. 1, the exhaust gas exiting both ends of the measurement chamber typically collides with a temperature below 50 degrees Celsius, but meets the cold free anti-pollution air in front of the lenses 7, 8, and drops to a temperature below the dew point for a very short time. To form a mist and get out. Fine droplets in the fog may adversely contaminate the lenses 7 and 8, but even worse, fine droplets in the fog may cause light beams to be refracted (scattered) and produce smoke-like effects. . Water molecules in the gaseous state do not absorb 550 to 570 NM rays as specified in ISO 11614, but when droplets act to scatter the rays, they make the same error as smoke. In general, this phenomenon does not occur in the spring, summer, early autumn weather in Korea, but this phenomenon occurs from late autumn to early spring, it is impossible to measure in the test conditions of the outside air or is measured higher than the actual soot concentration.

In-depth vehicle inspections conducted by the Ministry of Environment in Korea are carried out using diesel light transmission smoke measuring instruments under the conditions of outside air (applied to minus 10 degrees from room temperature). Alternatively, the present invention has been made for overcoming such a phenomenon because there is a possibility of applying a light transmission type soot measuring instrument also in the roadbed control). Detailed inspections of driving vehicles are presented in the Ministry of Environment's Air Quality Preservation Act, the Air Quality Preservation Act, and the National Institute of Environmental Research.

In FIG. 2, heaters and temperature sensors 16, 17, and 23 are additionally installed in the sampling line 15 of the conventional measuring instrument of FIG. 1 and the flow path or mechanism 22 of the anti-pollution air, respectively. A configuration diagram of a heated diesel light permeable smoke measuring device (hereinafter, abbreviated as 'heating type measuring device') of the present invention, which is configured to heat exhaust gas and anti-pollution air at a constant temperature, is shown.

The present invention of FIG. 2 is a heating type measuring device developed to overcome the disadvantages of the conventional measuring device of FIG. 1, and does not generate condensate in the sampling line 15 even at sub-zero temperatures. Provides a function to prevent the fog from forming in front of the lens of the light emitting portion 20 and the light receiving portion 21 collided with each other. To provide this function, the heater 16 and the temperature sensor 17 installed on the outer wall of the sampling line 15 can be controlled to a constant temperature. In addition, by installing a heater and a temperature sensor 23 in the mechanism 22 for supplying the antifouling air, it was possible to heat and supply the antifouling air at a constant temperature.

Through the study for the present invention, the heating temperature of the sampling line 15 is controlled to more than 80 degrees Celsius, and the heating temperature of the anti-pollution air is about 30 to 40 degrees Celsius, so there is a problem in measuring soot even at an ambient air temperature of minus 5 to 10 degrees. It was confirmed that did not occur.

Figure 1 is a conventional diesel light transmission smoke detector (hereinafter referred to as "conventional") consisting of a sampling probe, a sampling line, an optical unit, a measurement chamber, a fan and flow path for supplying anti-pollution air, a microcontroller, a measurement value indicating unit, and a print. Schematic diagram of 'measuring device'.

FIG. 2 is a schematic diagram of a heated diesel light permeable smoke measuring instrument (hereinafter referred to as a 'heating type measuring instrument') of the present invention, in which a heater and a temperature sensor are additionally installed in the flow path of the sampling line and the anti-pollution air of FIG. 1, respectively. Diagram.

3 shows the results of various test data measured in a conventional diesel lug-down test mode.

Fig. 4 is a comparison result of test data measured by installing a conventional measuring instrument and a heating type measuring instrument at the same time when the diesel rundown test is performed under the test conditions at an ambient temperature of minus 5 degrees.

FIG. 5 is a comparison result of data when only the anti-pollution air is heated and tested under the same test conditions as in FIG. 4 without heating the sampling line of the heated measuring instrument. FIG.

Fig. 6 is a comparison result of test data when only the sampling line of a heating measuring instrument is heated under the same test conditions as in Fig. 4 and the pollution prevention air is tested without heating.

FIG. 7 is a comparison result of test data when both the sampling line and the anti-pollution air of the heated measuring instrument are heated and tested under the same test conditions as in FIG. 4; FIG.

Explanation of symbols on the main parts of the drawings

1: end of exhaust pipe 2: sampling probe

3: sampling line 4: measuring room

5: Heater and temperature sensor of measuring room 6: Light emitting part

7 light emitting part lens 8 light receiving part lens

9: light receiving unit 10: fan for air pollution prevention

11 microcontroller 12 measured value indicator

13: end of exhaust pipe 14: sampling probe

15: sampling line 16: heater of sampling line

17: temperature sensor 18: measuring room

19: heater and temperature sensor in the measurement room 20: light emitting unit

21: light receiver 22: fan for preventing pollution air supply

23: heater and temperature sensor for air pollution prevention

24: microcontroller 25: measured value indicator

As shown in FIG. 2, the present invention provides a sampling probe 14, a heating sampling line in which a heater 16 is wrapped around an outer wall of a sampling line 15 of a conventional measuring device, and a temperature sensor 17 is installed together. Measuring chamber 18 in which sensor 19 is installed, optical unit consisting of light emitting unit 20 and light receiving unit 21, heating type in which heater and temperature sensor 23 are installed in conventional anti-pollution air supply mechanism 22 or flow path An anti-pollution air supply mechanism, a microcontroller 24, and a measurement value indicating section 25 for presenting the measured soot concentration to the tester.

The heated sampling lines 15, 16 and 17 and the heated pollution free air supply mechanisms 22 and 23 for controlling and heating the pollution free air at a constant temperature are interface circuits for temperature sensors to a conventional microcontroller. And by adding the power control circuit of the heater. In addition, by installing an independent temperature controller separately without modifying the conventional microcontroller, heating the sampling line 15 and the anti-pollution air 22 and controlling the temperature also have the same effect as those having ordinary knowledge. I can understand enough.

Figure 3 shows the various measured values measured in the conventional diesel lug-down test mode that is applied in the domestic vehicle overhaul inspection. The test was carried out using a commercial van. This test is a data measured using a heating type meter, it can be understood that the flue gas concentration changes qualitatively according to the speed of the engine and the vehicle. The engine was started just before 20 seconds of elapsed time, held idle for 30 seconds, and then accelerated. During the acceleration period of the vehicle up to 66 seconds, soot concentration increases as the transmission changes and the engine speed and load increase. At about 66 seconds, 70KM per hour was maintained for about 5 seconds before entering 1 mode. Mode 1 operates at the vehicle's rated power and maximum engine speed. Mode 2 operates at 90% engine speed by adding load to the vehicle. In mode 3, the vehicle is driven at 80% engine speed by adding load to the vehicle. From this test data, it can be seen that the fumes emitted from diesel vehicles are discharged more in the acceleration section than in the constant speed operation section.

FIG. 4 shows the results of a conventional diesel rundown test under test conditions at -5 ° C outside air temperature. This is the smoke concentration change when the measuring probe and the measuring probe of the conventional measuring instrument are inserted into the outlet of the exhaust pipe at the same time. Conventional measuring instruments show that the lens starts to be contaminated at the end of the acceleration period and shows no reliable results at the end of the 3 mode. However, the heated meter of the present invention shows very good results. By comparing the measured values between the conventional measuring device and the heating type measuring device in this figure, the effect of the heating type measuring device of the present invention can be sufficiently understood.

FIG. 5 compares data when only the anti-pollution air is heated and tested under the same test conditions as in FIG. 4 without heating the sampling line of the heating type measuring instrument. In other words, it is a test for evaluating the difference from the conventional measuring instrument when only the pollution prevention air is heated. In the rundown mode test, high concentration soot measurements emitted during the acceleration period were compared. Heated measuring instruments that only heat pollution-prevented air and conventional measuring instruments show little difference until the elapsed time of 18 seconds.However, the conventional measuring instruments have a large amount of instantaneous contamination caused by condensate generated from the sampling line. Shows an abnormal value in the 22 second interval. This contamination persists until 30 seconds after the acceleration section ends, and the difference between the two values remains.

Fig. 6 is a comparison result of test data when only the sampling line of a heating type measuring instrument is heated and the anti-fouling air is tested without heating under the same test conditions as in Fig. 4. There is no significant difference in data between the conventional measuring instrument and the heating type measuring instrument, but a difference occurs toward the end of acceleration. This effect is more likely to be caused by fog generated when anti-pollution air and exhaust gas collide in front of the lens of the optical unit, rather than the effect of the sampling line.

FIG. 7 is a comparison result of test data when both the sampling line and the anti-pollution air of the heated measuring instrument are heated and tested under the same test conditions as in FIG. 4. Conventional measuring instruments show slightly higher values than the heated measuring instruments from the beginning of the test, but the difference is increasing toward the end of acceleration.

In the above, the effect of heating only the pollution-prevented air at a constant temperature, the effect of heating only the sampling line at a constant temperature, and the effect of heating both sides was confirmed by a test for measuring the diesel soot concentration at an ambient air temperature of minus 5 degrees. It was. The overall effect can be understood through the significant difference accumulated after the acceleration period as shown in FIG.

As described above, the present invention provides a 'heating type diesel light transmission smoke analyzer' having a heater and a temperature sensor installed in a sampling line of a conventional measuring instrument, a pollution prevention air supply mechanism, or a flow path and a temperature sensor. It is a useful invention that overcomes the shortcomings of the conventional diesel light transmission smoke meter that could not be tested in sub-zero outside air.

The owner of the knowledge of conventional diesel permeation smoke detectors can see that various modifications are possible in accordance with the spirit of the present invention, and that such modifications are not new beyond the effects identified through the spirit and precise testing of the present invention. Will understand. It will also be appreciated that the effect of the present invention is very large.

Claims (2)

A sampling probe 14 inserted into the end 13 of the exhaust pipe for measuring soot concentration in the exhaust gas discharged from the diesel engine, A heating sampling line provided with a heater 16 and a temperature sensor 17 at a sampling line 15 coupled to an outlet of the sampling probe 14; A measuring chamber 18 coupled to the outlet of the heated sampling line and having a heater 19 installed therein to be heated to a constant temperature; An optical unit comprising a light emitting unit 20 and a light receiving unit 21 for measuring soot concentration by an optical method; Heater 23 is installed in the anti-pollution air supply mechanism 22 and the flow path, and a temperature sensor is installed at the outlet of the heater to feed and supply the temperature of the anti-pollution air to an optimum temperature through feedback control. Heating type pollution prevention air supply mechanism, The heating sampling line, the measurement chamber, and the heating anti-pollution air supply mechanism are heated to a constant temperature, the fan 22 for supplying the anti-pollution air is controlled, and the light source and the optical sensor of the optical units 20 and 21 are interfaced. And a microcontroller 24 which provides a function of converting the concentration of soot using the measured electrical signal. Heated diesel light transmission smoke meter comprising a measurement value indicating section 25 for presenting the measured soot concentration to the tester. delete