The Research Of Pumping Mode For Volatile Liquids During The Refueling Process

China is currently the second largest oil-consuming country in the world, which is less than the United States. Therefore, there is a large number of fuel sold by the fuel dispenser every day. Most of them belongs to volatile liquid, which has a larger saturated vapor pressure. So the pump system’s efficiency is exceedingly low, and its refueling precision can’t satisfy the national standards’ need. It is no doubt that the energy loss is very high during the refueling process.First of all, we analyze the shortcoming of efficiency and precise of pump system in refueling dispenser. Based on the use of variable frequency control technology, we obtain the new control mode for the aim of improving the efficiency and accuracy by theoretical analysis, numerical simulation and experiment. The main contents of this paper include the following aspects:1. In view of the pumping efficiency is not high, we analyze the construction of the pump system’s efficiency at full length and do a lot of relevant experiments, then put forward the adaptive control method which is proposed for improving the pump efficiency. The new system can search the best efficiency point during the refueling process by the means of adjust the VFC’s frequency in real time, the it makes the motor operate at the corresponding frequency. We also do lots of experiments for test and verify the accuracy of the new controller.2. For the aim of improving the refueling accuracy, we establish the corresponding mathematical model for minimum measurement. Then we propose the new variable frequency control mode which has buffer frequency. At last, we have done many test for verifying the effect of the new way.3. We discuss the harm of water hammer to the fuel pump system, a mathematical model is derived by mathematical calculation of water hammer. The test platform is built for verifying the accuracy of the calculation model. Then we obtain the relationship between pipeline flow, pipe length, pipe diameter, the valve’ closing time and water hammer through the result of MATLAB simulation. Finally, we put forward the control method to reduce the water hammer based on frequency conversion technology, and the accuracy of this control method is verified by the experimental results.