What Are Carbon Monoxide Emissions?

Carbon monoxide emissions refer to emissions of unburned carbon monoxide (CO) in automobile exhaust emissions. CO is the main intermediate product generated during the combustion of carbonaceous substances. If the oxygen concentration and temperature of the reaction gas are high enough and the chemical reaction takes a long time, CO will be oxidized to CO2. Therefore, the main reason for the generation of CO is carbonaceous substances. Incomplete combustion.

Basic Information

Chinese name

Carbon monoxide emissions

Field

car

Characteristics of carbon monoxide emissions

CO is colorless, odorless, non-irritating, and easily passes through the alveoli, capillaries, and placental barrier. The affinity of CO and hemoglobin in the blood is 200-250 times that of oxygen. After absorption into the blood, the carboxyhemoglobin produced by the combination of CO and hemoglobin has a dissociation rate 3600 times slower than that of oxyhemoglobin, which weakens the blood to human tissues. Oxygen supply capacity. When the volume fraction of CO in the air exceeds 0.1%, symptoms of poisoning such as headache and palpitation will occur; when it exceeds 3%, it can cause death within 30 minutes. An epidemiological investigation found that CO exposure is related to an increase in the morbidity and mortality of cardiovascular disease in the population, and low-concentration CO burst rates can also cause coronary heart disease patients to have arrhythmias and abnormal electrocardiograms.

Factors affecting carbon monoxide emissions

The main factor affecting the CO emissions is the excess air coefficient of the combustible mixture. In the rich mixture, the volume fraction of CO increases with the decrease of the excess air coefficient. This is due to incomplete fuel combustion caused by lack of oxygen. In the mixed gas, the CO volume fraction is always very low, only between 1.0 and 1.1, and the CO volume fraction has a more complicated change with the change of the excess air coefficient. At part load, the CO emissions are not high; at full load and cold start, the CO emissions are large; if the engine is accelerating, if the transition is rich, or the oil is continuously decelerating, and the fuel supply control in the transition condition is poor, the CO emissions will increase.

Measurement of carbon monoxide emissions

Non-diffusive infrared analyzer can be used to measure CO in tail gas emission, that is, in gas, except for diatomic gases of the same atom, other asymmetric molecular gases have the ability to absorb infrared light. Different gases have their own capabilities in the infrared band. The higher the gas concentration in the absorption band at a specific wavelength, the stronger the ability to absorb infrared light. By measuring the intensity of the transmitted infrared radiation, the concentration of the component to be measured can be determined.

Carbon monoxide emission prevention measures

The main measures for controlling CO emissions include controlling CO emissions from fixed sources of pollution; improving the composition and structure of fuels; devices that can catalyze CO purifiers in exhaust gases, and controlling vehicle exhaust emissions.