Method and device for measuring pollutant discharging total of motor vehicle

Abstract

The invention relates to vehicle pollutant discharging total measuring device and method. The device is made up of diluting sampling tube, fan, computer measure-control system, chassis power measuring machine, fan flow rate adjusting device, flow rate, temperature, and pressure measuring devices, five components tail gas, O2, CO2 gas analysis devices. The measuring method includes the following steps: using fan flow rate adjusting device to control pumping drainage fan, measure diluted tail gas flow rate, temperature, pressure, O2, CO2 volume density; using five components gas analysis device to measure undiluted tail gas for each gas volume density; calculating out the undiluted tail gas flow rate by the volume density ratio to gain vehicle pollutants discharging gross. The invention has high detecting precision for tail gas, can be used in pollutants discharging gross detecting for vehicle operating condition method tail gas detecting line or repair shop.

Description

technical field [0001] The invention relates to a measuring device and method for the total discharge of motor vehicle pollutants. Background technique [0002] With the rapid increase in automobile production and sales in recent years, the generation of a large number of automobile pollutants has become a common social problem. In some cities, motor vehicle pollution has become the number one source of pollution in cities. Existing detection methods of automobile exhaust pollutants include FTP, ASM and IM240 methods. The ASM detection method is based on the pollutant emission concentration rather than the total emission, which is unfair to vehicles with different engine displacements, and the total amount of pollutants cannot be counted; the test results of the three pollutants of HC, CO, and NO by the IM240 method Compared with the FTP results, the dispersion is very small, and the false positive rate is very low. However, the equipment cost of the IM240 working condition...

AI Technical Summary

Problems solved by technology

O as a tracer gas 2 or CO 2 Concentration change is very small, very small error (such as O 2 When the error is an absolute percentage of 0.1%, CO 2 When the error is an absolute percentage of 0.04%), it may cause a large error in the calculated dilution ratio

In addition, foreign patents use zirconia oxygen sensors as a tracer method for diluted exhaust gas, but electrochemical sensors are used for oxygen detection in undiluted exhaust gas. The response time of the two is very different, and it is difficult to achieve transient response.

Moreover, CO and HC in the diluted exhaust gas have a great influence on the zirconia oxygen sensor, which is easy to cause large errors

Domestic use of CO 2 Although the tracer method solves the problem of transient response, the CO 2 Tracing is easy to cause large dilution ratio errors, which has also been proved by a large number of domestic experiments

The above analysis shows that the previous methods are not suitable for the measurement of the exhaust gas of a large number of motor vehicles with a displacement of 0.8L-1.8L in my country, and at the same time cannot meet the requirements of the simple transient working condition method for vehicles in use in my country

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