Abstract
Keywords - Fuel-Water Separator, Water Separation Efficiency, Repeatability, Test Method, Water Droplet Dispersion
According to the requirement of the modern automobile diesel, the water in fuel must be eliminate thoroughly. Therefore the fuel-water separation function is prerequisite to the modern diesel fuel filter system. How to determine the water separation efficiency of the fuel-water separators accurately is the problem which should be resolved in urgent need.
In accordance with three test method standards in effect in the world, the same product CD72 sedimentor was tested repeadly. All the results of the test procedures are short of stability, repeatability and reproducibility. The reasons are: 1. At the fuel-inlet side of the tested fuel-water separators, it is difficult to control the consistency of water droplet dispersion in the fuel; 2. The precision of the flowmeter for minim water flow is too small, could hardly control the added water with 0.25% precisely; 3. The distribution of the small water drops, on the pipe section is misproportion, so it is difficult to get an exact sample.
After analysis and reseach, a new test method is offered: Base on the method of the SAE J1839, the water dispersion installation is adopted to get water droplets in the fuel flow about 180-260m, but the servo injector is adopted instead of feeding water flowmeter and the bulk sampling method is adopted instead of small sampling method.
After improving the test equipment and test procedure, the CD72 sedimentor was tested for the water separation efficiency altogether 10 times, the error of the test results isn´t exceeding 0.89%, the stability, repeatability and reproducibility are good enough.