Influence of Different Refueling Temperatures and Refueling Rates on Refueling Emission
Authors: Xu Qingyun , Gu Wangwen , Wang Jiguang , Xu Feng , Wang Meng 
Published: July 2023

Abstract
With the increase of automobiles on hand in China, automobile refueling emissions, as an important part of volatile organic compounds (VOC), have been paid more and more attention. Frequent refueling is related to the fuel vapor concentration and operation safety of the gas stations. Reducing refueling emissions can improve fuel vapor recovery efficiency and reduce fuel waste in gas stations. Therefore, the research on refueling emissions test began to attract attention. However, due to the long pre-processing time of the refueling test, the occupation of the laboratory, and the complicated operation of testers, most studies in China focus on the numerical simulation of a simplified refueling model or the impact analysis of refueling emission of the local fuel system, and there are fewer studies on refueling emission of the whole automobile. This paper aims to analyze the influence of automobile refueling emissions on the environment more scientifically and reduce the fuel vapor loss in refueling more reasonably. The influence of different refueling temperatures and refueling rates on the refueling emission of the whole automobile was investigated. The research showed that automobile refueling emissions increased with the refueling temperature increasing. When the refueling temperature increased to a certain extent, fuel splashing occurred in refueling. When the refueling temperatures are 10°C, 30°C, and 40°C, the refueling emissions of vehicles equipped with ORVR system are 0.92 times, 3.08 times, and 8.29 times than the standard refueling temperature (20°C). In actual refueling, it was recommended to adopt the refueling temperature of 20°C. The refueling emissions decreased first and then increased with the refueling rate. The refueling emissions with the increase in refueling rate were lower than that with the decrease in refueling rate. When the refueling rate is 7L/min, 27L/min, 47L/min, the refueling emissions of vehicles equipped with the ORVR system are 13 times, 1.25 times, and 1.75 times that of the standard refueling rate (37L/min). Too high a refueling rate could lead to fuel splashing; therefore, a refueling rate of 37 L/min was recommended. Compared with ordinary gasoline vehicles and gasoline vehicles equipped with the ORVR system, it can be seen that vehicles equipped with the ORVR system can reduce refueling emissions by 99%. According to an industry report, 12320.4386t gasoline can be saved throughout the year if all vehicles are installed with the ORVR system in 2017 in Yunnan province. It will save 39.3730t and 149.6174t gasoline, when the gas station chooses a refueling temperature of 20 °C throughout the year, compared with the refueling temperature of 30°C and 40°C. And using a refueling rate of 37 L/min can save 4.7248t and 14.1743t gasoline, compared with the refueling rates of 27 L/min and 47 L/min throughout the year. Therefore, it is recommended that China continue to promote the installation of the ORVR system. In the actual refueling process, it is recommended to choose a lower refueling temperature and slower refueling rates to save energy.