Exhaust gas sampling mechanism and exhaust gas analysis apparatus

Abstract

To provide an exhaust gas sampling mechanism which can prevent condensed water droplets in exhaust gas from being sampled by a sampling probe and advantageously sample only the gas components of the exhaust gas to be measured, thereby maintaining a high response speed in analyzing the exhaust gas, the exhaust gas sampling mechanism includes: the sampling probe disposed in a flow path through which the exhaust gas flows, for sampling the exhaust gas; and a gas-permeable cover which covers at least an upstream portion or a lateral surface portion of the sampling probe in the flow path, and has a water droplet removing structure.

Description

technical field [0001] The invention relates to an exhaust gas sampling mechanism, which is used for sampling exhaust gas from a flow path through which the exhaust gas flows. Background technique [0002] Conventionally, a part of the exhaust gas flowing in flow passages such as an exhaust pipe is sampled by an exhaust gas sampling mechanism, and the collected exhaust gas is introduced into an exhaust gas analysis device that detects carbon monoxide (CO), carbon dioxide ( CO 2 ), nitrogen oxides (NO X ) and total hydrocarbons (THC) in the exhaust gas are analyzed. [0003] Such as Figure 7 As shown, the exhaust gas sampling mechanism 3A includes: an installation pipe 31A installed at the open end of the vehicle exhaust pipe; a sampling probe 32A inserted into the interior from the outer side of the installation pipe 31A; and a substantially cylindrical protective tube 34A, covering the periphery of the sampling probe 32A in the flow channel (refer to Patent Document 1)....

AI Technical Summary

Problems solved by technology

[0005] However, in the structure of the protection tube 34A, when the water droplets condensed in the exhaust gas fly, they may enter the inside of the protection tube 34A and stay in the protection tube 34A.

In addition, if the moisture W stagnant, for example, below the inner surface of the protection tube 34A evaporates, the concentration of the moisture will be much higher than the concentration of the moisture that should be contained in the exhaust gas, which will cause not only a failure in the measurement of the moisture concentration Influence, and also have adverse effects on the measurement accuracy of other exhaust components due to moisture interference, etc.

In addition, if Figure 7 As shown, since the opening of the protective tube 34A faces in the opposite direction with respect to the advancing direction of the exhaust gas as a whole, it is difficult to introduce the exhaust gas into the protective tube 34A, which causes the analysis response speed of the exhaust gas analysis device to decrease.

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