Research Of Fuel Dispenser Pump System Based On DSP And Frequency Conversion

With the growing popularity of motor vehicles and the state's energy saving policies gradually in-depth,the demands for biofuel alcoholic gasoline mount up gradually. Because the biofuel alcoholic gasoline is volatile, the research on the corresponding fuel dispenser should be conducted in a great depth.The main purpose of this thesis is to research on the optimization control of the pump system during the transportation process of volatile liquid——ethanol gasoline. The pattern of subsistent fuel dispensers disregards the distinction of different fuels. When the flowrate exceeded 38L/min on the condition of common fuel pipe system, ethanol gasoline will generate lots of bubbles inside and become more volatile, and the flowrate will little increase with the pressure increasing according to the experiments. However, the flowrate of the existing fuel dispensers reaches to about 42L/min, and the motors always run at the highest speed. The server has to change the valve in order to control the flowrate, which is both an energy waste and an additional abrasion to the hydraulic pressure components.Against to shortage of the common fuel dispensers during the volatile fuel transportation above, this thesis creatively combines the frequency conversion technology with the pump system of common fuel dispenser to achieve the optimization control of ethanol gasoline's flowrate. The thesis improves the transportation pattern of ethanol gasoline, defines the 3 different levels of the fuel flowrate: Q1L/min,Q2L/min,and Q3L/min, which provides an automatic discrimination of different flowrate and an adaptive control to ensure a steady flow during fueling.According to the principle of the speed regulating in pump system, this paper analyzes the element and efficiency of the energy-saving in theory, and provide the strategy and method of control optimization to perfect the current fueling pattern of the volatile medium. On the one hand, as to the hardware, the DSP control plat form is composed of one of the HSC/THC20 series fuel dispensers with self priming pump and revenue control device which is produced by Tokheim Hengshan, the control panel with TI TMSLF2047 DSP chipset, and the 750E type embedded frequency convertor of Guangzhou Hongye Technology Co. Ltd. On the other hand, as to the software, the platform is based on the DSP developing software CCS2.2, and built with the adaptive discriminating algorithm of the signal acquirement and data processing, which brings along the adaptive control pattern of the automatical flow rate estimating during fueling. The testing results indicate that after applying the control optimization to the pump system of the fuel dispenser, the adaptive control pattern works well and the medium flow stably. In the mean time, the energy-saving effect appears distinct, which means 43.7% at least and 70% at most, and that the less the flow rate remains, the more distinct the effect appears. Furthermore, after the application, the system pressure of the dispenser becomes stable, the mechanical abrasion and the working noise decreased, and the service life of the hydraulic components is also prolonged.