The user has an account number in the database of petrochemical IC card system when handling the card, and the user's data is stored in the account number. There is an IC card (single user) under this account, and there is a mother card when there are multiple cards.
When users refuel at gas stations, they use IC cards to refuel. The amount of IC card to record users will decrease with the increase of fuel consumption. The IC card can't be refueled until the amount in this IC card is 0. At this time, the user himself or others help to pay the money in the account, but the IC card of the user who only pays the money still can't add oil.
Because the user's IC card does not store the amount information, the user has to store the information in the dedicated machine of the gas station, so that the user can continue to refuel with the data on the card.
Extended data:
China petrochemical refueling card was issued by China Petrochemical Company Limited in 2003. In Beijing, Shanghai, Tianjin, Hebei, Henan, Shandong, Shanxi, Hubei, Hunan, Guangdong, Guangxi, Fujian, Yunnan, Hainan, Zhejiang, Anhui, Jiangxi, Jiangsu, Guizhou and other 2 1 provinces and cities, more than 20,000 gas stations can enjoy refueling consumption and storage.
"Reserve", in English, refers to the part of commercial banks' deposits in the central bank that exceeds the statutory deposit reserve ratio, which is generally called excess reserve, also known as "payment reserve".
Broadly speaking, the payment reserve includes cash on hand and deposits in the central bank. The former is called cash reserve and the latter is called deposit reserve, in which deposit reserve is the main body. China's general payment reserve, that is, reserve fund, is a narrow deposit reserve, that is, the deposits deposited by financial institutions such as commercial banks in the central bank.
China commercial banks and other financial institutions in accordance with the provisions of the proportion of deposit reserves deposited in the central bank, in addition to the decline in customer deposits can be reduced or returned, shall not be withdrawn or used. Actually, it can't be used as a payment preparation. Since 1989, the central bank has approved the ratio of payment reserve to customer deposits according to the different conditions of commercial banks and other financial institutions. Unless there are special circumstances, the deposit in the central bank shall not be lower than this ratio.
References:
China petrochemical refueling card-Baidu Encyclopedia Reserve Fund-Baidu Encyclopedia