降低NO_x排放量的根本途径有两条,一是降低最高燃烧温度;二是降低气缸中的相对氧浓度。到目前为止,比较可行的措施有:改进燃烧过程,如稀薄混合气燃烧;推迟点火;废气再循环;喷水及催化反应方式等。我们在红旗轿车上采用了废气再循环的方法降低NO_x,相比之下,它的净化效果好,比较简单、可靠,不要求发动机有较大的改变,容易实现。 There are two basic ways to reduce NO_x emissions, one is to reduce the maximum combustion temperature; the other is to reduce the relative oxygen concentration in the cylinder. So far, more feasible measures are: to improve the combustion process, such as lean mixture combustion; delayed ignition; exhaust gas recirculation; water and catalytic reactions. We Red Flag sedan using exhaust gas recirculation method to reduce NO_x, compared to its purification effect is good, relatively simple and reliable, does not require a larger engine change, easy to achieve.