JPH08278238A - Bypass dilution tunnel apparatus - Google Patents

Abstract

PURPOSE: To easily execute the measuring accuracy inspection of an analytical means as a whole, i.e., of the system of a bypass dilution apparatus as a whole, in the bypass dilution apparatus by which a part of a test gas is introduced into a dilution tunnel, as a bypassing test gas, via an introduction pipe so as to be used as a diluted gas and by which the diluted gas is used as an object whose component is to be analyzed by the analytical means. CONSTITUTION: An analytical means is provided with first component-amount measuring means 34, 74, 76 which measure at least one component amount in a test gas and with second component-amount measuring means which measure at least one component in a diluted gas. A bypassing dilution tunnel apparatus is provided with a measuring accuracy inspection means 50 by which, when the total flow rate of the test gas is discharged into a dilution tunnel via an introduction pipe 12 by test gas supply means 62, 64, the total amount of one component amount in the test gas is compared with the total amount of the same component amount in the diluted gas and by which the measuring accuracy inspection of the analytical means is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diluting diluting tunnel device, and more particularly to a multi-tube diluting diluting tunnel device equipped with measuring accuracy checking means for various measuring means.

[0002]

2. Description of the Related Art Exhaust gas from an internal combustion engine such as an automobile engine contains fine particles and components that adversely affect the atmosphere. Therefore, research is being conducted to improve the internal combustion engine and reduce particulates and air pollutant components by collecting exhaust gas as a test gas and analyzing its components.

Usually, in the analysis of exhaust gas components, a part of the exhaust gas is introduced as a divided exhaust gas (divided test gas) into a diluting tunnel and diluted with a diluting gas such as air.
A split-flow dilution tunnel device that collects the diluted exhaust gas as a sample is used. This split-flow dilution tunnel device is equipped with a multi-tube type divider consisting of a plurality of split flow tubes of the same diameter and the same length that are bundled, and the exhaust gas from the internal combustion engine is used as the test gas. Each of the flow dividing pipes inside is divided evenly and passes through. Then, one of these flow dividing pipes serves as an introducing pipe, whereby a part of the exhaust gas, that is, a divided exhaust gas (divided test gas) is introduced into the dilution tunnel.

At this time, since the flow dividing pipe and the introducing pipe of the divider have the same inner diameter and the same length, the ratio of the divided exhaust gas flow rate to the total exhaust gas flow rate, that is, the division ratio, is determined by the number ratio. Has been decided. Therefore, by converting the analysis result of the divided exhaust gas guided into the dilution tunnel by the introduction pipe based on this division ratio, the components in all the exhaust gas can be satisfactorily grasped.

[0005]

In such a split flow dilution tunnel device, HC, CO and C are used as analysis means.
Various measuring instruments such as an analyzer for measuring the concentration of gas components such as O ₂ and NOx and a flow meter for measuring the gas flow rate are provided. These various measuring instruments are delicate measuring instruments, and if they are used for a long period of time, the measurement accuracy may gradually become incorrect. If the measurement accuracy deteriorates in this way, accurate analysis results cannot be obtained.

Therefore, it is conceivable to individually inspect each of these various measuring instruments, but this method requires a large-scale inspection device depending on the measuring instrument.
It takes time and effort. Further, even if all the measuring instruments maintain good accuracy, it cannot be determined as good unless all of them are inspected. Therefore, this method is not practical as an inspection means that is regularly performed.

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to easily perform measurement accuracy inspection of the entire system of a diversion dilution tunnel device, and to perform periodical measurement of various measuring instruments. It is an object of the present invention to provide a split-flow dilution tunnel device that can easily perform accuracy inspection.

[0008]

In order to achieve the above-mentioned object, the invention of claim 1 allows a test gas to flow in a multi-tube type divider in which a plurality of flow dividing pipes are bundled, and one of the flow dividing pipes The diversion pipe is introduced into the dilution tunnel as the introduction pipe, and the diversion test gas discharged from the introduction pipe is diluted with the dilution gas flowing in the dilution tunnel to be the diluted gas, and the diluted gas is analyzed by the analysis means. In the split-flow dilution tunnel device to be analyzed, the analyzing means measures a first component amount measuring means for measuring at least one component amount in the test gas and the at least one component amount in the diluted gas. A second component amount measuring means for discharging the total flow rate of the test gas into the dilution tunnel through the introduction pipe, and the total test gas supply means. The diluted tunnel When the total flow rate of the test gas is discharged into the inside, the total amount of one component in the test gas measured by the first component amount measuring means and the second component amount measuring means are measured. It is characterized by comprising a measurement accuracy inspection means for performing measurement accuracy inspection of the analysis means by comparing with the total amount of the same component in the diluted gas.

According to the second aspect of the invention, the first component amount measuring means measures the concentration of the component in the test gas.
And a first flow rate measuring means for measuring the total flow rate of the test gas, while the second component amount measuring means measures the concentration of the component in the diluted gas. It is characterized by including a measuring means and a second flow rate measuring means for measuring the total diluted gas flow rate.

Further, in the invention of claim 3, the at least one component is carbon dioxide, and the measurement accuracy inspection means determines the total carbon dioxide amount in the test gas and the total carbon dioxide amount in the diluted gas. The measurement accuracy inspection of the analysis means is performed by comparing

[0011]

According to the split-flow dilution tunnel device of claim 1, when all the test gases are supplied to the introduction pipe by the all-test gas supply means, the first component amount measuring means of the analyzing means measures the total quantity of the test gas. The component amount in the test gas is measured, and the component amount in the diluted gas is measured by the second component amount measuring means of the analyzing means. Then, the measurement accuracy inspection means compares the total amount of one component in the test gas with the total amount of the same component in the diluted gas, that is, the consistency is verified, and as a result, the entire analysis means, that is, diversion dilution is performed. The measurement accuracy inspection of the entire tunnel device system is performed.

According to the split-flow dilution tunnel device of the second aspect, the first concentration measuring means for measuring the component concentration in the test gas, the first flow rate measuring means for measuring the total flow rate of the test gas, and the dilution device. By the second concentration measuring means for measuring the concentration of the component in the diluted gas and the second flow rate measuring means for measuring the flow rate of the total diluted gas, the total amount of one component in the test gas and the same component in the diluted gas are measured. And the total amount of is accurately and satisfactorily obtained. Even when the analysis means has a large number of measurement means in this way, the measurement accuracy inspection means easily evaluates the measurement accuracy of the entire analysis means, that is, the entire system of the diversion dilution tunnel device. It

According to the split-flow dilution tunnel device of claim 3, the total amount of carbon dioxide in the test gas and the total amount of carbon dioxide in the diluted gas are compared, and this carbon dioxide is a stable gas. Therefore, the measurement accuracy inspection of the analysis means is accurately performed.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration diagram of the split flow dilution tunnel device. As shown in the figure, a multi-tube divider 4 including a plurality of flow dividing pipes is connected to an exhaust passage 2 into which exhaust gas (test gas) discharged from an engine (not shown) of a vehicle flows. ing. Flange joints 2a and 4a are integrally formed in the exhaust passage 2 and the multi-tube type divider 4, respectively. The exhaust passage 2 and the multi-pipe type divider 4 are such that the flange joints 2a and 4a are fasteners. It is fixed and connected to each other. Therefore, the exhaust passage 2 can be attached to and detached from the multi-tube divider 4.

The multi-tube type divider 4 is constructed by bundling diversion tubes having the same length and the same inner diameter (for example, 10 mm).
The exhaust gas from the exhaust passage 2 is equally divided and flows into each of the flow dividing pipes. A surge tank 6 that stabilizes the flow of exhaust gas is connected downstream of the multi-tube divider 4, and the exhaust gas is directed toward the exhaust gas recovery device (not shown) via this surge tank 6. Exhausted.

One of the plurality of flow dividing pipes of the multi-tube divider 4 is an exhaust gas introducing pipe 12, and the exhaust gas introducing pipe 1
2 is branched from the middle, bent in a direction different from that of the other flow dividing pipes, and extends to the central portion in the tubular dilution tunnel 14. The discharge port 16 of the exhaust gas introducing pipe 12 is opened toward the downstream direction of the dilution tunnel 14, whereby a part of the exhaust gas introduced into the dilution tunnel 14 through the exhaust gas introducing pipe 12, that is, The divided exhaust gas (divided test gas) flows out along the dilution tunnel 14.

By the way, since the flow dividing pipe in the multi-tube type divider 4 and the exhaust gas introducing pipe 12 have the same inner diameter and length, the dividing ratio of the flow rate of the exhaust gas is determined in advance from the ratio of the numbers. As for this division ratio, as described later, the component analysis is performed with the division exhaust gas divided in the dilution tunnel 14,
It is an important value when converting the analysis results for all exhaust gases.

The dilution tunnel 14 is for diluting the split exhaust gas. A constant volume sampling device (CVS) 32 is provided at the downstream end of the dilution tunnel 14,
This constant volume sample device 32 is adapted to draw in the dilution gas (here, air) from the upstream end of the dilution tunnel 14 that opens toward the dilution gas atmosphere (here, the atmosphere). As a result, the divided exhaust gas is diluted. Also,
An opening / closing valve 20 is provided at the upstream end of the dilution tunnel 14, and the opening / closing valve 20 can adjust the inflow amount of the dilution gas.

The constant volume sampling device 32 detects the flow rate of the diluted exhaust gas flowing through the dilution tunnel 14 (second flow rate measuring means). The constant volume sample device 32 is then electrically connected to the analyzer 50, which
The flow rate of the diluted exhaust gas flowing through the dilution tunnel 14 is calculated. A collection tube 22 for collecting the diluted exhaust gas in the dilution tunnel 14 is provided in front of the constant volume sampling device 32. This collection tube 2
No. 2 is inserted into the dilution tunnel 14 from the outside of the dilution tunnel 14, and its tip is open toward the upstream side of the dilution tunnel 14. On the other hand, an exhaust gas analyzer (second concentration measuring means) 24 is connected to the rear end, and the exhaust gas analyzer 24 is supplied with the diluted exhaust gas collected by the collecting pipe 22. , H in diluted exhaust gas
The concentrations of contained components such as C, CO, CO ₂ , and NOx are detected. This exhaust gas analyzer 24 is an analyzer 5
It is electrically connected to 0.

Further, similarly to the collecting tube 22, the collecting tube 2
6 is inserted into the dilution tunnel 14 from the outside of the dilution tunnel 14, and the tip thereof is open toward the upstream side of the dilution tunnel 14. A filter 28 for collecting particulates such as particulates in the diluted exhaust gas is interposed in the collecting pipe 26 so that the particulates can be captured. A sample device (PMS) 30 for sucking the diluted exhaust gas is provided at the rear end of the collecting tube 26, whereby the particles are stably adsorbed by the filter 28.

The reference numeral 34 in the figure collects exhaust gas passing through the exhaust passage 2, and collects HC, CO, CO ₂ ,
It is an exhaust gas analyzer (first concentration measuring means) for detecting the concentration of contained components such as NOx, and the exhaust gas analyzer 34 is electrically connected to the analyzer 50. This makes it possible to directly analyze the components in the exhaust gas from the engine separately from the exhaust gas analyzer 24 described above. The exhaust gas analyzer 34 is attachable to and detachable from the exhaust passage 2.

Further, a dilution gas analyzer 36 is provided upstream of the dilution tunnel 14, and this dilution gas analyzer 36 draws O ₂ and CO of the dilution gas (atmosphere) drawn into the dilution tunnel 14. _The concentration of contained components such as ₂ is detected.
The analyzer 36 is also electrically connected to the analyzer 50. The analyzer 50 includes the exhaust gas analyzer 2 described above.
4, a constant-volume sample device 32, an exhaust gas analyzer 34, and a diluent gas analyzer 36 are electrically connected, and this analyzer 50 is used for various calculations such as concentration calculation based on the detection signals from the above-mentioned respective measuring instruments. It is possible to perform arithmetic processing and output the arithmetic result.

Next, the operation of the split flow diluting tunnel device constructed as described above during normal use will be described. The divided exhaust gas is diluted through the exhaust gas introduction pipe 12 into the dilution tunnel 1.
When introduced into the No. 4, the divided exhaust gas is diluted with the diluent gas flowing from the upstream side of the dilution tunnel 14. Then, a part of the diluted exhaust gas is collected through the sample pipe 22 and the sample pipe 26, and the exhaust gas analyzer 24 detects the concentration of each component such as CO, CO ₂ , NOx in the diluted exhaust gas. In addition, fine particles are captured by the filter 28.

Then, based on various detection signals, CO, CO
The concentration of ₂ , NOx, etc. is calculated by the analyzer 50. At this time, each measurement result is converted into the case of all the exhaust gases based on the above-mentioned division ratio, that is, the ratio of the number of the flow dividing pipes and the number of the exhaust gas introducing pipes 12. The amount of fine particles is also measured, and this amount is also converted based on the division ratio. FIG. 2 shows a schematic configuration diagram of a diversion dilution tunnel device equipped with a measurement accuracy inspection unit 60 additionally provided in the diversion dilution tunnel device.

The measurement accuracy inspection unit 60 is attached by removing the exhaust passage 2 shown in FIG. 1 and replacing it with the exhaust passage 2. The configuration of the measurement accuracy inspection unit 60 will be described below. As shown in the figure, the multi-tube divider 4 includes a conical taper pipe (total test gas supply means) 62 of the measurement accuracy inspection unit 60.
However, they are connected so that one end on the tapered side faces the multi-tube divider 4 side. A flange joint 62a is formed on the tapered side of the taper pipe 62, and the taper pipe 62 and the multi-tube divider 4 are connected to each other by fixing the flange joints 4a and 62a with fasteners.

The taper pipe 62 has an opening shape and an opening area which are the same as those of the exhaust gas introducing pipe 12 on the tapered side. Then, when the tapered tube 62 is connected to the multi-tube divider 4, the positions of these openings correspond to each other and communicate with each other. That is, all the openings of the split pipes other than the exhaust gas introduction pipe 12 are closed by the flange joint, and the exhaust gas flows only into the exhaust gas introduction pipe 12 and does not flow into the split pipe.

To the other end of the taper pipe 62, an exhaust pipe 66 of a small engine (total test gas supply means) 64 having a small displacement (for example, about 200 cc) is connected. A flange joint 66a is formed on the exhaust pipe 66, and a flange joint 62b is formed on the other end of the taper pipe 62. The taper pipe 62 and the exhaust pipe 66 have flange joints 62b, 66a.
Are fixed and connected with fasteners.

An intake pipe 68 for sucking air is connected to the small engine 64, and an air cleaner 70 is connected to the tip of the intake pipe 68. A fuel pipe 72 for supplying fuel to each combustion chamber is also connected to the small engine 64. Therefore, when the small engine 64 is operated, the exhaust gas discharged from the small engine 64 is sent to the taper pipe 62 via the exhaust pipe 66, and the entire amount of the exhaust gas is passed through the exhaust gas introduction pipe 12 and the dilution tunnel 14. Will be supplied within.

The exhaust pipe 66 is provided with the exhaust gas analyzer 34 once removed from the exhaust passage 2. As described above, the exhaust gas analyzer 34 is electrically connected to the analyzer 50 and outputs a detection signal to the analyzer 50. A flow meter (first flow rate measuring means) 74 is attached to the air cleaner 70,
The flowmeter 74 detects the intake air amount Qa taken into the small engine 64. This flow meter 74 is also electrically connected to the analyzer 50.

Further, the fuel pipe 72 has a fuel flow meter (first
Of the fuel supplied to the small engine 64.
f is detected. This fuel flow meter 76
Is also electrically connected to the analyzer 50. The operation of the diversion dilution tunnel device when performing the measurement accuracy inspection using the measurement accuracy inspection unit 60 will be described below.

When the small engine 64 is started, the exhaust pipe 6
Exhaust gas is supplied into the dilution tunnel 14 via 6 and the exhaust gas introduction pipe 12. Since the small engine 64 has a small displacement (about 200 cc), the exhaust gas smoothly flows through the exhaust gas introduction pipe 12, and the entire amount is surely sent into the dilution tunnel 14. At this time, since no exhaust gas flows into the other split pipes of the multi-tube divider 4, the split ratio of the exhaust gas is 1.

Then, the intake air amount Qa and the fuel flow amount Qf are detected by the flow meter 74 and the fuel flow meter 76, and these detection signals are supplied to the analyzer 50. Then, these values are arithmetically processed in the analyzer 50. At this time, these weight flow rates, that is, the intake air weight flow rate Ga and the fuel weight flow rate Gf are calculated based on the intake air amount Qa and the fuel flow rate Qf, which are volumetric flow rates.

The exhaust gas analyzers 24 and 34 detect the concentration of each component such as CO, CO ₂ and NOx in the exhaust gas. Then, these detection signals are analyzed by the analyzer 5.
It is supplied to 0 for arithmetic processing. Further, the constant volume sampling device 32 detects the flow rate Vmix of the diluted exhaust gas. Then, the detection signal is supplied to the analyzer 50 and subjected to arithmetic processing.

When each measured value is obtained in this way, the measurement accuracy of the diversion dilution tunnel device is confirmed based on these measured values. The measurement accuracy confirmation will be described in detail below. The measurement accuracy is confirmed by the analyzer 50 executing the arithmetic expression of the following expression (1).

SR = (XA × XB) / (XC × XD) (1) XA = KWD × DCO₂-BCO₂ XB = Qe + VDCO₂ XC = KWT × TCO₂-BCO₂ XD = Vmix + VPMS + VTCO₂ In this equation (1), the denominator side (XC × XD) on the right side is the dilution
All CO in channel 14 ₂Shows the amount (the amount of the second component
(Measurement means), the molecular side (XA x XB) is the entire exhaust pipe 66
CO₂The amount is shown (first component amount measuring means). Follow
This formula (1) is based on the total CO in the dilution tunnel 14.₂Quantity and
All CO in the exhaust pipe 66₂It becomes the formula to calculate the ratio SR with the quantity
ing.

Here, DCO ₂ is C in the exhaust gas from the small engine 64 detected by the exhaust gas analyzer 34.
Is the O ₂ concentration and TCO ₂ is the CO ₂ concentration in the diluted exhaust gas detected by the exhaust gas analyzer 24. Further, BCO ₂ is the CO ₂ concentration in the diluted gas (air) detected by the dilution gas analyzer 36, the CO ₂ concentration BCO ₂ is, CO ₂ in order to obtain an accurate concentration of CO ₂ in the exhaust gas Excluded from the concentration DCO ₂ and CO ₂ concentration TCO ₂ .

KWD and KWT are CO ₂ concentrations DCO ₂ and TCO _2.
Is a correction coefficient for converting each to a concentration in a dry state containing no water. As a result, the CO ₂ concentration D
CO ₂ and TCO ₂ in the dilution gas (atmosphere) above CO ₂ concentration BC
Same conditions as O ₂ . Qe is a small engine 64
It is the flow rate of exhaust gas discharged from. The exhaust gas flow rate Qe is the intake air amount Qa and the intake air weight flow rate G described above.
It is calculated by the following equation (2) from a and the fuel weight flow rate Gf.

Qe = Qa × (1 + Gf / Ga) (2) VDCO ₂ is the amount of sample exhaust gas collected by the exhaust gas analyzer 34 to measure the CO ₂ concentration DCO _2, etc. the gas volume VDCO ₂ exhaust gas flow rate Q
An accurate exhaust gas flow rate is obtained by adding it to e. The sample exhaust gas amount VDCO ₂ is set in advance by experiments or the like.

Vmix is the above-mentioned diluted exhaust gas flow rate. Further, VPMS is the amount of the exhausted diluted exhaust gas sucked by the sample device 30 to capture the fine particles, and VTCO ₂ is the sample dilution sampled by the exhaust gas analyzer 24 to measure TCO _{2 and the} like. It is the amount of exhausted gas. Then, the suction diluted exhaust gas amount VPMS and the sample diluted exhaust gas amount VTCO ₂ are added to the diluted exhaust gas flow rate Vmix to obtain an accurate diluted exhaust gas flow rate. The suction diluted exhaust gas amount VPMS is obtained by a flow meter (not shown) provided in the sample device 30, and the sample diluted exhaust gas amount VTCO ₂ is set in advance by experiments or the like.

When the ratio SR is obtained from the calculation result of the equation (1), the analyzer 50 determines whether or not the ratio SR is 1 (measurement accuracy inspection means). As described above, also since the total flow rate of exhaust gas is supplied into the dilution tunnel 14, the ratio SR is split ratio between the total amount of CO ₂ total amount of CO ₂ within the exhaust pipe 66 in the dilution tunnel 14 The value should be 1, and it is determined here whether the ratio SR is the same value 1 as the division ratio.

According to this determination, when the ratio SR matches the value 1, all the exhaust gas analyzers 24 and 34 and the dilution gas analyzer 36 function normally with good measurement accuracy. It can be determined that there is. At the same time, a flow meter 74 connected to the constant volume sampling device 32 and the small engine 64.
Also, the measurement accuracy of all the flow rate measuring means of the fuel flow meter 76 can be determined to be good.

However, if the ratio SR does not match the value 1, it is possible to determine that the measurement accuracy of any of the analyzers or any of the flow meters is poor. In practice, a predetermined range (for example, ± 5%) sandwiching the value 1 is regarded as the measurement accuracy allowable range, and when the ratio SR is outside this predetermined range, it is determined that the measurement accuracy is poor. Then, when the measurement accuracy defect of one of the analyzers or one of the flowmeters is confirmed as described above, the exhaust gas analyzer 24,
34 and dilution gas analyzer 36 and constant volume sample device 3
2. The measurement accuracy of the flow meter 74 and the fuel flow meter 76 will be inspected in detail. The detailed inspection method of each measuring instrument is publicly known, and the explanation is omitted here.

By the way, in this measurement accuracy inspection, the output of the small engine 64 at the time of performing the inspection is kept constant, but the output is changed and the inspection is performed under several different outputs. Of course, it is preferable to carry out, for example, 13 kinds of output modes (13 modes). As described above in detail, when all the exhaust gases from the small engine 64 are introduced into the dilution tunnel 14 and the division ratio is set to 1, the total amount of CO _{2 in the} exhaust gas and the diluted exhaust gas are diluted. total amount of CO ₂ and is consistent, the ratio SR between the total amount of CO ₂ and in the diluted exhaust gas total CO ₂ amount of exhaust gas
Also has a value of 1, so by judging whether or not the ratio SR of the total amount of CO ₂ based on the detection signal from each measuring device has a value of 1, it is possible to divert the dilute flow without inspecting each individual measuring device. The measurement accuracy of the entire tunnel device system can be easily confirmed. Therefore, by using the split-flow dilution tunnel device of the present invention, it is possible to easily and sufficiently carry out a periodic inspection that is regularly performed without any trouble.

In the above embodiment, the exhaust gas introducing pipe 12
Although the taper pipe 62 is used to guide the total amount of exhaust gas to, it is not always necessary to use the taper pipe 62. For example, the exhaust pipe 66 is directly connected to the multitubular divider 4, At this time, the openings of the flow dividing pipes other than the exhaust gas introducing pipe 12 may be closed with masking tape or the like.

[0045]

As described above, according to the split flow diluting tunnel device of the first aspect, the test gas is caused to flow in the multi-tube type divider in which a plurality of flow split tubes are bundled, and one of the flow split tubes is divided. It is introduced into the dilution tunnel as an introduction pipe, and the split flow test gas discharged from the introduction pipe is diluted with the dilution gas flowing in the dilution tunnel to be a diluted gas, and this diluted gas is the target of the component analysis by the analysis means. In the diversion dilution tunnel device,
The analysis unit includes a first component amount measuring unit that measures at least one component amount in the test gas and a second component amount measuring unit that measures at least one component amount in the diluted gas. When the total flow rate of the test gas is discharged into the dilution tunnel by the total test gas supply means for discharging the total flow rate of the test gas through the introduction pipe into the dilution tunnel, By comparing the total amount of one component in the test gas measured by the first component amount measuring device with the total amount of the same component amount in the diluted gas measured by the second component amount measuring device Since the measurement accuracy inspection means for performing the measurement accuracy inspection of the analysis means is provided, the measurement accuracy inspection of the entire analysis means, that is, the entire system of the diversion dilution tunnel device can be easily and favorably performed.

According to the split-flow dilution tunnel device of the second aspect, the first component amount measuring means and the first concentration measuring means for measuring the component concentration in the test gas and the total test gas flow rate. And a second flow rate measuring means for
Since the gas component amount measuring means of No. 2 includes the second concentration measuring means for measuring the component concentration in the diluted gas and the second flow rate measuring means for measuring the total diluted gas flow rate,
The total amount of one component in the test gas and the total amount of the same component in the diluted gas can be accurately and satisfactorily obtained.
Even when the analysis means has a large number of measurement means in this way, it is possible to evaluate the measurement accuracy of the entire analysis means, that is, the entire system of the diversion dilution tunnel device without inspecting the measurement accuracy one by one. It can be done easily.

According to the split-flow dilution tunnel device of the third aspect, at least one component is carbon dioxide, and the measurement accuracy inspection means includes the total amount of carbon dioxide in the test gas and the total dioxide in the diluted gas. Since the measurement accuracy test of the analysis means is performed by comparing with the carbon amount, the measurement accuracy test with high inspection accuracy can be performed by comparing the amount of carbon dioxide which is a stable gas.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a split flow dilution tunnel device.

FIG. 2 is a schematic configuration diagram showing a diversion dilution tunnel device with a measurement accuracy inspection unit attached.

[Explanation of symbols]

 4 Multi-tube type divider 12 Exhaust gas introduction pipe 14 Dilution tunnel 24 Exhaust gas analyzer (second concentration measuring means) 32 Constant volume sample device (second flow rate measuring means) 34 Exhaust gas analyzer (first concentration) Measuring means) 36 Diluting gas analyzer 50 Analyzer (measurement accuracy inspection means) 60 Measurement accuracy inspection unit 62 Tapered pipe (total test gas supply means) 64 Small engine (total test gas supply means) 74 Flowmeter (first) Flow rate measuring means) 76 Fuel flow meter (first flow rate measuring means)

Claims (3)

[Claims] 1. A test gas is caused to flow in a multi-tube type divider in which a plurality of flow dividing pipes are bundled, and one of the flow dividing pipes is introduced as an introduction pipe into a dilution tunnel and discharged from the introduction pipe. In a split-flow dilution tunnel device in which a split-flow test gas is diluted with a diluent gas flowing in the dilution tunnel to obtain a diluted gas, and the diluted gas is a target of component analysis by an analysis unit, the analysis unit is a test gas. A first component amount measuring means for measuring at least one component amount in the diluted gas, and a second component amount measuring means for measuring the at least one component amount in the diluted gas. When the total flow rate of the test gas is discharged into the dilution tunnel by the total test gas supply unit that discharges the total flow rate of the test gas through the introduction pipe, 1 component quantity meter By comparing the total amount of one component in the test gas measured by the measuring unit with the total amount of the same component in the diluted gas measured by the second component amount measuring unit, the analyzing unit Measurement accuracy inspection means for performing measurement accuracy inspection of
A split flow diluting tunnel device comprising: 2. The first component amount measuring means includes first concentration measuring means for measuring a component concentration in a test gas and first flow rate measuring means for measuring a total test gas flow rate. Becomes
On the other hand, the second component amount measuring means includes second concentration measuring means for measuring the component concentration in the diluted gas and second flow rate measuring means for measuring the total diluted gas flow rate. The split flow dilution tunnel device according to claim 1. 3. The at least one component is carbon dioxide, and the measurement accuracy inspection means compares the total carbon dioxide amount in the test gas with the total carbon dioxide amount in the diluted gas, The split-flow dilution tunnel device according to claim 1 or 2, wherein a measurement accuracy inspection of the analysis means is performed.