基于车用氮氧化物传感器的工程机械NO_x排放因子测量方法研究

Research on construction machinery NO_x emission factor measurement method based on vehicular NO_x sensor

为了能够低成本地获得包括工程机械在内的非道路移动机械的NO_x排放因子,基于目前广泛使用的车用氮氧化物传感器开展了NO_x排放因子的测量系统搭建和计算模型研究.基于柴油机尾气O_2浓度、NO_x浓度、环境温湿度和燃料特性等参数建立了非道路移动机械单位油耗NO_x排放因子计算模型.为了验证测量系统与计算模型,开展了4台工程机械的实际道路验证试验,并选取其中一台开展了基于车载排放测试系统(PEMS)的NO_x排放比对试验.比对和实测试验结果表明建立的NO_x排放因子测量方法具有较低的相对误差和稳定性,与车载排放测量系统的测量结果相比具有很好的相关性.被测2台挖掘机和1台推土机、1台压路机的平均单位油耗NO_x排放因子分别为(22.8±4.0)、(35.8±16.0)和(55.0±18.0)、(68.8±13.0) g·kg^(-1).基于车用氮氧化物传感器的NO_x排放因子测量结果与目前国内外已有研究的NO_x排放因子测量结果接近.

In order to obtain the NOx emission factors of non-road mobile machinery which including construction machinery at low cost, the establishment and algorithm of the measurement system of transient fuel-specific NOx emission factor is carried out based on the currently widely used vehicular NOx sensor. The formula of instantaneous fuel specific NOx emission factor was established by the oxygen concentration, nitrogen oxide concentration and ambient temperature, humidity. In order to verify the measurement system and the algorithm, the real operation condition test of four construction machineries were carried out, and one of them was selected to carry out the emission comparison experiment based on the portable emission measurement system(PEMS). The comparison and the verification experiments results show that the established NOx emission factor measurement method has low relative error and excellent stability. The established measurement method has a good correlation with the measurement results of the PEMS. The average fuel-specific NOx emission factors of the two excavators, one excavator and one roller measured as shown in the verification test results are(32.4±4.0),(35.8±16.0) and(55.0±18.0),(68.8±13.0) g·kg^-1 respectively. NOx emission factors obtained by the measurement method based on the vehicle NOx sensor are similar to the existing worldwide research results.