Lightproof smokemeter gas path automatic switching device and automatic switching method

Abstract

The invention discloses a lightproof smokemeter gas path automatic switching device and method. The device comprises a switching main body which is provided with a switching cavity, a switching cavity wall forming the switching cavity, and three opening parts formed on the switching cavity wall and communicated with the switching cavity; the center of the bottom end of one opening part is positioned on a vertical line of a connecting line of the centers of the bottom ends of the other two opening parts; a rotor is rotationally installed on the inner side of the switching main body wall and comprises a T-shaped channel and a rotor wall which forms the T-shaped channel and is used for sealing the opening parts, the rotating center line of the rotor is perpendicular to the plane where the centers of the bottom ends of the three opening parts are located, and the T-shaped channel is provided with three ports used for being communicated with the three opening parts respectively; the output end of a rotary driving source is fixedly connected with the rotor wall. According to the lightproof smokemeter gas path automatic switching device and the method, the three gas paths which need to pass through when the lightproof smokemeter is used for measuring tail gas of a diesel engine can be automatically switched, the labor cost is saved, and the device and the method are convenient to operate, high in efficiency and high in measurement precision.

Description

technical field [0001] The invention relates to the technical field of diesel engine tail gas detection, in particular to an automatic switching device and an automatic switching method for an opacimeter gas path. Background technique [0002] According to the relevant regulations in "GB 3847-2018 Diesel Vehicle Pollutant Emission Limits and Measurement Methods (Free Acceleration Method and Loading Deceleration Method)", when the opacimeter uses the free acceleration method to measure diesel engine exhaust, it needs to pass Three gas circuit switching processes: 1. The instrument needs to be connected to clean air for zero point calibration before the measurement starts; 2. The exhaust pipe of the diesel engine is emptied before the measurement starts, and the residual pollutants in the pipeline are blown out by stepping on the accelerator three times ;3. After the instrument and diesel engine are ready, insert the instrument sampling tube into the exhaust pipe for samplin...

AI Technical Summary

Problems solved by technology

[0005] 1. When two people are operating, because most of the diesel engines are used as power devices for large machinery and vehicles, the noise is loud and the distance between the cab and the exhaust port is far away, and there is a visual obstruction. The communication and cooperation of two people are affected by noise and vision Prone to problems leading to inaccurate measurements

[0006] 2. If it is only operated by one person, it needs to manually unplug and insert the sampling tube back and forth at both ends of the cab and the exhaust port to achieve the purpose of gas path switching, which consumes a lot of physical strength for the operator and reduces work efficiency

[0007] 3. When manually plugging and unplugging the sampling tube, it is necessary to touch the high-temperature sampling tube with bare hands. If no protective measures are taken, it is easy to burn; and when plugging and unplugging the sampling tube, it is necessary to face the exhaust pipe at a close distance, which will inhale a large amount of exhaust gas

Repeated manual extraction and insertion of sampling tubes at close range will cause harm to human health

[0008] 4. If it is necessary to repeat the measurement after the measurement is completed, during each measurement, the sampling tube inserted into the exhaust port of the diesel engine needs to be pulled out during the purging action, and then the sampling tube is manually inserted after the purging is completed. The depth of the sampling end extending into the exhaust port of the diesel engine has a certain influence on the measurement results, and it is difficult to ensure the uniform depth of the sampling end in each measurement process, which makes the measurement results of repeated measurements have certain errors

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