عنوان مقاله [English]
CO pollutant gas is an odorless and highly toxic gas and is one of the toxic pollutants caused by incomplete combustion in cars. In this study, the amount of carbon monoxide and hydrocarbon pollutants produced by gasoline and CNG vehicles has been analyzed. These studies have been done according to the amount of vehicle mileage. Attempts have been made to select vehicles so that the amounts of CO and HC emissions produced in gasoline and CNG vehicles are in the same range for a more accurate comparison. According to studies, the amount of carbon monoxide pollutants produced in a CNG vehicle with 733,000 km is almost equal to a gasoline vehicle with 242,000 km. Also, the minimum value for a CNG vehicle with 210,000 km is 0.39. While in the same mileage for gasoline vehicles, this value is estimated at about 0.58. In the case of hydrocarbon pollutants, the conditions are better for CNG vehicles and they produce fewer pollutants in the same kilometers. Thus, the amount of hydrocarbon pollutants produced in 733,000 km of CNG vehicles is slightly different from its amount in 242,000 km of gasoline vehicles.
Today, vehicles are considered as one of the main causes of pollution in the world. Therefore, the issue of increasing environmental pollution has caused serious strictures to be considered to control the amount of pollution produced by vehicles. CO pollutant is a colorless, odorless and highly toxic gas that is one of the causes of incomplete combustion in cars. The toxicity of carbon monoxide is due to the fact that the tendency of hemoglobin to combine with CO is 200 to 250 times that of oxygen. Therefore, due to the importance of environmental pollutants created by cars, many researchers have done research in this field.
Mehdi Niajalili et al. have investigated the effect of using optimal wires in the car ignition system on its emissions. The researchers used low-resistance wires in the ignition system and investigated the effect of using these wires on pollutants such as CO, HC, CO2 and O2. The researchers finally stated that the use of optimal wires can reduce the CO parameter in the output of healthy vehicles by up to 60%. It also reduces the amount of HC pollutants to an acceptable level.
Dehghan et al. have also researched on the emissions of several vehicles. These researchers conducted their research in the city of Shiraz. They analyzed CO, CO2 and HC pollutants in vehicles and evaluated the relationship between the year of production of the vehicle and the amount of emissions of these pollutants. They stated that there was a significant and negative relationship between the year of production and the amount of CO and HC production, so that with the increase of the year of car production, the amount of these pollutants decreases.
In this study, 8 Pride cars with different vehicle mileage and production years have been analyzed and the CO and HC parameters produced by these cars in two categories of CNG and gasoline based on the vehicle mileage of the said car have been investigated.
Investigation of CO and HC gases in study vehicles
In this section, eight cars, including four gasoline cars and four CNG cars are considered. Then, using the vehicle gas analyzer device called QROTECH (QRO-401) the exhaust gases of study vehicles are recorded and analyzed. This device, which has high accuracy and strength, can be used within two to eight minutes after turning on. This emission control device is also capable of measuring CO, HC, NOx, O2 and CO2 emissions. It is noteworthy that all study cars are Pride type and have similar conditions and are considered only with differences in the fuel system (gasoline and CNG). In the selection of cars, the criterion of the range of pollutants produced and the mileage of the car is considered and the year of production of the car has no effect on its selection. In addition, there is no obligation to include the production range of vehicle pollutants in the standard range.
In the next step, the reported values are analyzed. As mentioned, the criterion for selecting cars was the mileage of the car and the year of production did not affect the selection of studied cars. In addition, vehicles have been selected so that the high and low percentages of CO gas for both groups of vehicles are in close range, so that the results can be better analyzed. According to research, the percentage of CO pollutants in CNG vehicles is much lower. So that the CO pollution produced in 733000 km in CNG vehicles with the same parameter in one third of a kilometer of gasoline vehicle mileage is equal. According to investigation, with the increase of vehicle mileage, the amounts of CO and HC emissions increase, but according to vehicle data, the growth of CO emissions in gasoline vehicles is higher. According to research, similar results are obtained for HC. That is, with the increase of mileage of gasoline vehicles, the growth rate of HC pollutants increases more than CNG vehicles. The amount of this pollutant at 733000 km in CNG vehicles is estimated at 230 ppm. However, in gasoline vehicles, the amount of HC pollutants at 242,000 km is measured at 240 ppm.
Due to the fact that vehicles are one of the most important sources of pollution in cities, this paper examines the impact of vehicle mileage on the production of CO and HC pollutants in gasoline and CNG vehicles. These cars, all of which are Pride, have similar physical conditions and are selected only with differences in the fuel system. According to studies, with increasing vehicle mileage, the amounts of CO and HC emissions in both gasoline and CNG vehicles are increased. But in the gasoline type, the slope of increasing these parameters has been evaluated more. Thus, the values of these parameters in 733000 km of CNG vehicles are almost equal to the same parameters in 242000 km of gasoline vehicles, and these values confirm that the pollutants produced by gasoline vehicles during long-term operation can have more effects on the environment. Therefore, by promoting CNG vehicle technology and using more of these vehicles in urban traffic, the amounts of CO and HC pollutants can be significantly reduced in the long-term. This creates healthier air and a cleaner environment.