JP3424545B2 - Transpiration gas measuring device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the measurement of a vaporized gas component, for example, a hydrocarbon (HC) of a gas vaporized from a fuel tank or an engine body of a parked vehicle. The present invention relates to an evaporative gas measurement device. 2. Description of the Related Art In recent years, not only hydrocarbons (HC) but also HC evaporating from a fuel tank or an engine body of a parked vehicle are emitted not only from hydrocarbons (HC) but also components emitted from a combustion gas during traveling. It is subject to gas regulations. For this reason, it is necessary to evaluate the HC concentration that evaporates when the vehicle is parked outdoors for a long period of time.Conventionally, HC vaporized by the evaporation gas measurement device that reproduces the situation where the vehicle has been parked outdoors for a long period of time is required. The concentration has been detected. A conventional vaporized gas measuring device will be described with reference to FIG. FIG. 4 shows the overall configuration of a conventional vaporized gas measuring device. As shown in the figure, the measurement target vehicle (vehicle)
The inside of the closed chamber 1 in which the chamber 7 is accommodated is maintained at a constant temperature (for example, a predetermined temperature between 20 ° C. and 30 ° C.) by the air conditioner 2. The gas inside the closed chamber 1 is sent from the sampling point 3 to the analyzer 5 by the supply pipe 4, and the gas that has been analyzed by the analyzer 5 is returned to the inside of the closed chamber 1 by the return pipe 6. In the conventional vaporized gas measuring apparatus, the inside of the closed chamber 1 is maintained at a constant temperature by the air conditioner 2, and the gas inside the closed chamber 1 is sent to the analyzer 5 by the feed pipe 4 at the start of measurement. After the HC concentration has been analyzed, the feed pipe 4
Thus, the gas inside the closed chamber 1 is sent to the analyzer 5 to analyze the HC concentration. Then, based on the HC concentration of the gas in the closed chamber at the start of the measurement and the HC concentration of the gas in the closed chamber sampled with time, the amount of HC evaporating from the vehicle 7 is measured, and the vehicle is kept outdoors for a long time. HC that evaporates when parked
The amount of is estimated. [0005] However, since the actual outdoor temperature varies within a day, a conventional vaporized gas measuring apparatus that measures while maintaining a constant temperature in a closed room is not used. It was impossible to detect the HC concentration according to the actual situation, and it was not possible to accurately estimate the amount of HC to be evaporated. [0006] Therefore, it is conceivable to change the temperature in the closed room in accordance with the temperature change of the day. However, changing the temperature in the closed chamber changes the pressure in the closed chamber,
A control device that absorbs the expansion and contraction of the air in the closed chamber and maintains the pressure at a constant level is required, resulting in a large-scale device. In addition, the control for evaluating the HC concentration becomes complicated. For this reason, the vaporized gas measuring device that changes the temperature in the closed room cannot be modified from the existing vaporized gas measuring device, and becomes an expensive device. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a vaporized gas measuring apparatus capable of inexpensively and accurately estimating a vaporized gas component of gas vaporized from a parked vehicle in response to a temperature change. Aim. [0008] In order to achieve the above object, according to the present invention, an atmosphere environment in a closed room accommodating a vehicle to be measured is set to an environment suitable for measurement conditions by environment setting means, and a communication pipe is provided. Communicates between the closed chamber and the outside air. A first detecting means for detecting a vaporized gas component in the closed chamber is provided, and a second detecting means for detecting a vaporized gas component in the communication pipe is provided in the communication pipe. The first detecting means detects the vaporized gas component inside the closed chamber, and the second detecting means detects the vaporized gas component in a state where the communication pipe is closed by the shut-off valve. (2) Analyzing the vaporized gas component by the analyzing means based on the detection information of the detecting means. Since the detection by the second detection means is performed in a state where the communication pipe is closed by the shut-off valve, the detection result of the second detection means is prevented from being mixed with gas due to a temperature difference between the inside of the closed chamber and the outside, and the detection is accurate. Done in As the first detecting means and the second detecting means, a system for taking out a gas containing a vaporized gas component and sending it to the analyzing means is used, and the gas sent to the analyzing means by the first detecting means is placed in a closed chamber after the analysis. Will be returned. The gas sent to the analysis means by the second detection means when the gas flows from the closed chamber to the outside air is returned to the closed chamber after the analysis, and the gas is returned to the closed chamber from the outside air when the gas flows to the closed chamber. 2 The gas sent to the analysis means by the detection means is returned to the outside air after the analysis. The above switching is
This is performed by controlling the temperature sensor and the supply / exhaust valve. FIG. 1 is an overall configuration of a vaporized gas measuring apparatus according to an embodiment of the present invention, FIG. 2 is a graph showing a temperature state in a closed chamber, and FIG. 3 shows a table of the operation status of the valve. As shown in FIG. 1, a vehicle to be measured (vehicle)
An air conditioner 13 and a temperature sensor 14 are provided in a sealed room 12 that accommodates 11, and detection information of the temperature sensor 14 is sent to a temperature controller 15. The air conditioner 13 is operated via the temperature controller 15 based on the detection information of the temperature sensor 14, and the temperature in the closed chamber 12 is maintained at a predetermined state. A signal from the setting controller 16 is input to the temperature controller 15, and the air conditioner 13 is operated so that the temperature inside the closed chamber 12 becomes the set temperature with the passage of time. That is, as shown in FIG.
The maximum temperature T ° C (eg, 40 ° C) is reached in 2 hours, and the minimum temperature t ° C (eg, 18 ° C) is the same temperature as the measurement started in 24 hours.
The temperature for the elapsed time is set so that
One cycle of measurement time is 72 hours. The air conditioner 13, the temperature sensor 14, the temperature controller 15 and the setting controller 16 constitute an environment setting means for setting the atmosphere environment in the closed room 12 to an environment suitable for the measurement conditions. As shown in FIG. 1, a base end of a supply / exhaust pipe 17 as a communication pipe is connected to the closed chamber 12.
The front end faces the outside air through the filter 18. The supply / exhaust pipe 17 is provided with a shutoff valve 19, and the shutoff valve 19 closes the supply / exhaust pipe 17 by a valve controller 20 to shut off the inside and the outside of the sealed chamber 12. A signal from the setting controller 16 is input to the valve controller 20. A first chamber for extracting gas inside the closed chamber 12 is provided.
A sampling point 21 is provided, and a supply / exhaust pipe 17 between the shutoff valve 19 and the filter 18 is provided.
A second sampling point 22 is provided for extracting the gas inside. The second sampling point 22 is connected to the analyzer 24 by a first feed pipe 23, and the first sampling point 21 is connected to an intermediate portion of the first feed pipe 23 by a second feed pipe 25. First sampling point 21 and second sampling point 2
The gas extracted from 2 is sent to the analyzer 24, where the HC concentration is analyzed. The gas analyzed by the analyzer 24 is returned to the closed chamber 12 or the atmosphere by the return pipe 26. The first feed pipe 23 has a first on-off valve 27
The second feed pipe 25 is provided with a second on-off valve 28, the return pipe 26 is provided with a third on-off valve 29, and the return pipe 26 between the analyzer 24 and the third on-off valve 29 is provided with a flow path. A switching valve 30 for switching the pressure to the atmosphere side is provided. The first on-off valve 27, the second on-off valve 28, the third on-off valve 29, and the switching valve 30 are individually operated by the valve controller 20 in conjunction with the cycle of FIG. In the vaporized gas measuring device having the above-described configuration, the vehicle 11 is disposed in the closed chamber 12, and the temperature controller 15 controls the inside of the closed chamber 12 to the temperature environment shown in FIG. 2 for 72 hours. Meanwhile, from the start of measurement to the end of measurement, the inside of the closed chamber 12 or the supply / exhaust pipe 17
The gas inside is sent to the analyzer 24, and the analyzer 24 analyzes the HC concentration. The change with time in the concentration of HC evaporating from the vehicle 11 is evaluated based on the state of the HC concentration from the start of measurement to the end of measurement. That is, the amount of HC transpiration is determined from the HC concentration at the start of measurement, the HC concentration at the end of measurement, and the volume in the closed chamber 12, and the HC concentration of the gas sampled in the middle is corrected to finally evaporate HC. Find the quantity. Thus, the amount of HC evaporated when the vehicle is parked outdoors for a long time (72 hours) is estimated, and the amount of HC evaporated in the vehicle 11 is measured. Hereinafter, the operation of the above-described vaporized gas measuring device will be described in detail. At the start of measurement, gas in the closed chamber 12 is extracted from the first sampling point 21 and the
The concentration is analyzed, and the analyzed gas is returned to the closed chamber 12. That is, as shown in FIG. 3, the shutoff valve 19 and the first on-off valve 27
Is closed, the second on-off valve 28 and the third on-off valve 29 are opened, and the switching valve 30 is switched to the return pipe 26 side. In this state, the gas extracted from the first sampling point 21 is sent to the analyzer 24 through the second feed pipe 25,
After the HC concentration is analyzed by the analyzer 24, the HC concentration is returned to the closed chamber 12 from the return pipe 26. When the measurement is started, the shut-off valve 19 is opened to allow the closed chamber 12 to communicate with the outside air, thereby absorbing the pressure fluctuation due to the temperature change in the closed chamber 12. When the temperature rises at the time of measurement every predetermined sample time, gas is exhausted to the outside air in the supply / exhaust pipe 17. Therefore, the gas in the closed chamber 12 is extracted from the first sampling point 21, the HC concentration is analyzed by the analyzer 24, and the analyzed gas is returned to the closed chamber 12. That is, as shown in FIG. 3, the shutoff valve 19 and the first on-off valve 27 are closed, and the second
The on-off valve 28 and the third on-off valve 29 are opened, and the switching valve 30 is switched to the return pipe 26 side. In this state, the gas extracted from the first sampling point 21 is sent to the analyzer 24 through the second feed pipe 25 and the first feed pipe 23, and the return pipe 26 after the HC concentration is analyzed by the analyzer 24. From the closed chamber 12. When the temperature drops at the time of measurement at every predetermined sample time, gas is sucked from the outside air into the supply / exhaust pipe 17. For this reason, the gas in the supply / exhaust pipe 17 is extracted from the second sampling point 22, the HC concentration is analyzed by the analyzer 24, and the analyzed gas is released to the outside. That is, as shown in FIG. 3, the shutoff valve 19, the second on-off valve 28, and the third on-off valve 29 are closed, the first on-off valve 27 is opened, and the switching valve 30 is switched to the outside air side. In this state, the gas extracted from the second sampling point 22 is sent to the analyzer 24 through the first feed pipe 23, and is discharged to the outside air after the HC concentration is analyzed by the analyzer 24. At the end of the measurement, the gas in the closed chamber 12 is extracted from the first sampling point 21 and the
The concentration is analyzed, and the analyzed gas is returned to the closed chamber 12. That is, as shown in FIG. 3, the shutoff valve 19, the first on-off valve 27, and the third on-off valve 29 are closed, the second on-off valve 28 is opened, and the switching valve 30 is switched to the outside air side. In this state, the gas extracted from the first sampling point 21 is sent to the analyzer 24 through the second feed pipe 25, and the analyzer 24
After the concentration is analyzed, it is released to the outside air. The HC concentration at the start of the measurement, the HC concentration at the end of the measurement, and the volume in the closed chamber 12 measured as described above.
By calculating the amount of HC transpiration and correcting the HC concentration of the gas sampled on the way to finally obtain the amount of HC transpiration, the temporal change in the concentration of HC transpired from the vehicle 11 is evaluated. Accordingly, the amount of HC evaporated when the vehicle 11 is parked outdoors for a long time (72 hours) is estimated, and the amount of HC evaporated of the vehicle 11 is measured. The above-mentioned vaporized gas measuring device closes the shut-off valve 19 at the time of measurement every predetermined sample time,
When the temperature rises, gas with a low HC concentration on the atmosphere side does not enter the sampling point, and when the temperature decreases, gas with a high HC concentration on the closed chamber 12 side does not enter. For this reason, there is no possibility that the measurement accuracy is deteriorated. In particular, at the inflection point where the temperature changes from rising to falling or the temperature changes from falling to rising, there is almost no temperature difference and there is little gas flow.
Is provided, there is no mixing of gas and deterioration of measurement accuracy can be prevented. When the gas in the closed chamber 12 is extracted from the first sampling point 21, the return pipe 26
When the gas in the supply / exhaust pipe 17 is extracted from the second sampling point 22, the gas is released to the outside air. For this reason, even before the measurement, the state of the gas before the measurement can be maintained, and in this respect, there is no possibility that the measurement accuracy is deteriorated. The return of the gas after measurement by the return pipe 26 and the release to the outside air may not be performed in some cases. Therefore, it is possible to accurately measure the concentration of HC evaporating from the vehicle 11 in the same environment as the environment left outdoors by keeping the pressure in the closed chamber 12 constant without performing any special pressure control. In addition, since a large-scale pressure control device is not required, and special control according to pressure fluctuation is not required, the above-mentioned evaporative gas measurement device can be modified by partially modifying existing equipment (for example, the conventional equipment shown in FIG. 4). Can be constructed. For this reason, it becomes possible to provide a transpired gas measuring device that can estimate the concentration of HC evaporating from a parked vehicle inexpensively and accurately in response to a temperature change. The vaporized gas measuring apparatus according to the present invention can accurately measure the vaporized gas component vaporized from a measurement vehicle in the same environment as an environment left outdoors while keeping the pressure in the closed chamber constant irrespective of the temperature change. Can be measured. In addition, a large-scale pressure control device is not required, and special control according to pressure fluctuation is not required. Therefore, it is possible to construct a vaporized gas measurement device by partially modifying existing equipment. For this reason, it becomes possible to provide a transpired gas measuring device that can estimate the transpired gas component evaporating from the parked vehicle inexpensively and accurately in response to the temperature change.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall configuration diagram of a vaporized gas measuring device according to an embodiment of the present invention. FIG. 2 is a graph showing a temperature state in a closed room. FIG. 3 is a table showing an operation state of a valve at the time of measurement. FIG. 4 is an overall configuration diagram of a conventional evaporated gas measuring device. [Description of Signs] 11 Measurement target vehicle (vehicle) 12 Closed room 13 Air conditioner 14 Temperature sensor 15 Temperature controller 16 Setting controller 17 Supply / exhaust pipe 19 Shutoff valve 20 Valve controller 21 First sample point 22 Second sample point 24 Analyzer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01M 17/007 G01N 1/22

Claims (1)

(57) [Claim 1] A sealed room for accommodating a vehicle to be measured, environment setting means for setting an atmosphere environment in the sealed room to an environment suitable for measurement conditions, and the closed room and outside air. A first communicating means for detecting a vaporized gas component inside the closed chamber; a second detecting means for detecting a vaporized gas component inside the communication pipe; and a second detecting means. A shutoff valve provided in the communication pipe between the airtight chamber and the closed chamber to close the communication pipe at the time of detection by the second detection means, and a vaporized gas based on information detected by the first detection means and the second detection means. An evaporative gas measurement device, comprising: analysis means for analyzing a component.