压差法机动车高温尾气瞬时流量测量

Instantaneous flow measurement of high temperature exhaust gas of motor vehicles based on differential pressure

机动车高温尾气流量对机动车尾气中排放因子含量的测量有着重要影响。基于压差式流量计理论模型,以DSP处理芯片为核心,综合热电偶、压力传感器、压差传感器及高温尾气采样管路等部件集成了高温尾气瞬时流量计,研发了相应的检测和处理电路,搭建了高温尾气实验平台,进行了流量检测的实验。实验结果表明,研发的流量计可准确测得机动车高温尾气的瞬时质量流量,其最大误差小于4.5%,平均误差仅为2.17%。为高温尾气流量的准确检测提供了技术装置,具有一定的工程应用价值。

The mass flow rate of vehicle exhaust significantly influence the measurement of the exhaust pollutants emission factors. Based on the study of the theoretical model of differential pressure flow meter, the architecture of high temperature exhaust flow meter is designed. With the DSP as core, a high temperature exhaust flow meter is integrated with improving Pitot tube, thermocouple, pressure gauge, differential pressure gauge and high temperature tail gas sampling pipeline. The corresponding detection and processing circuit is designed, the high temperature exhaust experimental platform is built, and the experiment of flow detection is carried out. The experimental results show that the flow meter can accurately measure the instantaneous mass flow of high temperature exhaust gas of motor vehicles. The maximum error is less than 4.5%, and the average error is only 2.17%. It provides a technical device for accurate detection of high temperature exhaust gas flow and has certain engineering application value.