PURIFICATION TECHNOLOGY OF FUEL FOR ELECTRONIC FUEL INJECTION DIESEL ENGINEAFTER ADOPTING ELECTRONIC FUEL INJECTION TECHNOLOGY, DIESEL ENGINES HAVE RECEIVED POSITIVE EVALUATIONS FOR ENERGY SAVING, HIGH EFFICIENCY, ENVIRONMENTAL PROTECTION, AND CONVENIENT MAINTENANCE. HOWEVER, MANY USERS COMPLAIN THAT ELECTRONIC FUEL INJECTION ENGINES HAVE FREQUENT MALFUNCTIONS AND HIGH REPLACEMENT COSTS. THE COMMON FAULTS OF ELECTRONIC FUEL INJECTION ENGINES ARE DIFFICULTY STARTING, DECREASED POWER, AND THE COST OF REPLACING THE FUEL INJECTOR OR FUEL SUPPLY PUMP CAN EASILY REACH TENS OF THOUSANDS OF YUAN. THE POPULAR SAYING IS THAT "THE CAR FUEL IS NOT COMPATIBLE" AND THE QUALITY OF DOMESTIC DIESEL ENGINES IS POOR. THE AUTHOR BELIEVES THAT THE KEY LIES IN THE INADEQUATE HANDLING OF POLLUTION ISSUES AFTER DIESEL EXTRACTION FROM THE FACTORY.THE WORLD FUEL ORGANIZATION (WWFC) HAS CONFIRMED THAT HALF OF THE FUEL SOLD GLOBALLY DOES NOT MEET THE POLLUTION LEVELS OF ISO 18/16/13 IN THE RETAIL PROCESS. FACED WITH COMPLEX ELECTRONIC FUEL INJECTION SYSTEMS, HIGHER QUALITY CLEAN DIESEL IS NEEDED THAN EVER BEFORE, ESPECIALLY WITH HIGHER REQUIREMENTS FOR POLLUTION LEVELS AND WATER CONTENT.KEY INDICATORS OF DIESEL POLLUTIONSOLID PARTICLE POLLUTION LEVELACCORDING TO THE NATIONAL STANDARDS "ORDINARY DIESEL" (GB252-2011) OR "VEHICLE DIESEL (IV)" (GB19147-2013), THE MECHANICAL IMPURITIES OF COMPLIANT DIESEL ARE "FREE" WHEN IT LEAVES THE FACTORY. WHEN MEASURING, VISUAL INSPECTION CAN BE USED. INJECT THE OIL SAMPLE INTO A 100MG GLASS GRADUATED CYLINDER AND OBSERVE QUALITATIVELY AT ROOM TEMPERATURE. IT SHOULD BE TRANSPARENT AND FREE OF SUSPENDED AND SETTLED IMPURITIES. WHEN QUANTITATIVE MEASUREMENT IS REQUIRED, FOLLOW GB/T511 FOR TESTING.IF DIESEL IS MIXED WITH MECHANICAL IMPURITIES SUCH AS DUST, SAND, AND METAL RUST DURING STORAGE, TRANSPORTATION, AND PRESERVATION, IT WILL BE CONTAMINATED. MECHANICAL IMPURITIES IN FUEL CAN CAUSE SEVERE ABRASIVE WEAR OF THE FUEL SUPPLY PUMP AND BLOCKAGE OR JAMMING OF THE FUEL INJECTOR UNDER HIGH OIL PRESSURE. IN ADDITION, IF DIESEL IS STORED IMPROPERLY OR FOR TOO LONG, THE HYDROCARBONS IN THE OIL WILL UNDERGO EVAPORATION, OXIDATION, POLYMERIZATION, AND CONDENSATION BY HOT AIR FLOW, OR UNDERGO CHEMICAL REACTIONS WITH WATER AND METALS, RESULTING IN THE FORMATION OF DARK VISCOUS GUM. THESE RESIDUAL GUMS ARE VERY HARMFUL AND CAN EASILY CLOG THE DIESEL FILTER ELEMENT. AFTER THERMAL DECOMPOSITION, THEY CAN BLOCK THE FUEL INJECTOR.IN ORDER TO CONTROL THE POLLUTION OF SOLID PARTICLES (INORGANIC MECHANICAL IMPURITIES AND ORGANIC RESIDUAL GUM) IN DIESEL, AN AUTOMATIC PARTICLE COUNTER CAN BE USED TO MONITOR AND ENSURE THAT THE DIESEL INJECTED INTO THE FUEL TANK MEETS THE POLLUTION LEVEL OF GB18/16/13.THE POLLUTION LEVEL SHOWN IN FIGURE 1 IS DETERMINED ACCORDING TO GB/T14039. IT IS A SET OF DISTRIBUTION STATISTICS DATA. THE FIRST CODE "18" REPRESENTS PER MILLILITERTHE TOTAL NUMBER OF PARTICLES WITH A SIZE ≥ 4 Μ M IN DIESEL SHALL NOT EXCEED 1900; THE SECOND CODE "16" INDICATES THAT THE TOTAL NUMBER OF PARTICLES WITH A SIZE ≥ 6 Μ M PER MILLILITER OF DIESEL DOES NOT EXCEED 700; THE TOTAL NUMBER OF PARTICLES WITH A SIZE ≥ 14 Μ M PER MILLILITER OF DIESEL IN THE THIRD CODE "13" TABLE SHALL NOT EXCEED 60.USING A LASER AUTOMATIC PARTICLE COUNTER WITH FOUR CHANNELS FOR MEASUREMENT, WITH A SENSITIVITY OF 1 Μ M, IT CAN BE USED FOR BOTH SAMPLING INSPECTION AND ONLINE MONITORING.MOISTURE CONTENTWHEN COMPLIANT DIESEL LEAVES THE FACTORY, ACCORDING TO THE NATIONAL STANDARDS "ORDINARY DIESEL" (GB252-2011) OR "VEHICLE DIESEL (1V)" (GB19147-2013) AND REGULATIONS, IF THE MOISTURE CONTENT (VOLUME FRACTION) IS BELOW 0.03%, IT IS CONSIDERED A "MARK". WHEN MEASURING, THE OIL SAMPLE CAN BE INJECTED INTO A 100MG GLASS GRADUATED CYLINDER AND QUALITATIVELY OBSERVED AT ROOM TEMPERATURE. IT SHOULD BE TRANSPARENT AND FREE OF SUSPENDED AND SETTLED MOISTURE. WHEN QUANTITATIVE MEASUREMENT IS REQUIRED, FOLLOW GB/T260 FOR TESTING.DURING THE STORAGE AND TRANSPORTATION OF DIESEL, IF WATER IS MIXED IN, IT CAN CAUSE WATER POLLUTION OF DIESEL. WATER POLLUTION CAUSES METAL CORROSION, WEAKENS THE FILTERING ABILITY OF THE FILTER ELEMENT, REDUCES THE OIL FILM STRENGTH OF DIESEL, AND EXACERBATES THE WEAR AND TEAR OF THE FUEL DELIVERY PUMP, FUEL SUPPLY PUMP, AND INJECTOR, EVEN LEADING TO TEARING AND SINTERING.THE MOISTURE CONTENT IN DIESEL CAN BE MEASURED USING A MOISTURE METER. THE MOISTURE DETECTOR SHOWN IN FIGURE 3 CAN BE USED FOR ONLINE MONITORING.THREE PURIFICATION TECHNOLOGIESPRECIPITATION FILTRATION PURIFICATIONTHE DIESEL FILTRATION DEVICE INSTALLED ON THE DIESEL ENGINE, ALTHOUGH HAVING THE FUNCTION OF DEHYDRATION FILTRATION, HAS LIMITED ABILITY TO HIDE AND ABSORB DIRT. POLLUTED DIESEL SHOULD BE PURIFIED BEFORE BEING ADDED TO THE FUEL TANK.THE TRADITIONAL MULTI-STAGE FILTRATION METHOD USES OPEN FILTERS OR FABRICS FOR FILTRATION WHEN UNLOADING OIL FROM TANK TRUCKS TO OIL DEPOTS, LOADING OIL FROM OIL TANKS TO REFUELING TRUCKS, AND REFUELING FROM REFUELING TRUCKS (GAS STATIONS) TO USERS' OIL DRUMS OR DIESEL ENGINE FUEL TANKS.THE SIMPLEST METHOD FOR DIESEL PURIFICATION IS TO USE OIL TANKS OR BARRELS TO ALLOW THE DIESEL TO SETTLE FOR 72-96 HOURS.THERE ARE THREE FORMS OF WATER MIXED INTO DIESEL: ① DISSOLVED WATER, WHICH EXISTS IN THE GAPS BETWEEN MOLECULES OF HYDROCARBON COMPOUNDS. THE SOLUBILITY SATURATION OF WATER IN OIL IS VERY LOW. AT LOW TEMPERATURES, DISSOLVED WATER WILL PRECIPITATE AND BECOME SUSPENDED WATER SUSPENDED WATER, AS TINY WATER DROPLETS SUSPENDED IN OIL, CAN CAUSE EMULSIFICATION OF DIESEL AND IS DIFFICULT TO REMOVE BY PRECIPITATION FREE WATER, MIXED WITH LARGER WATER DROPLETS IN OIL. DUE TO THE FACT THAT WATER HAS A SPECIFIC GRAVITY ONLY ABOUT 15% HIGHER THAN DIESEL, THE SETTLING RATE OF FREE WATER IS VERY SLOW. IT TAKES 3 DAYS FOR FREE WATER TO SETTLE AT THE BOTTOM OF THE OIL TANK IN THE FORM OF A WATER CUSHION.THE METHOD OF SEDIMENTATION FILTRATION PURIFICATION REQUIRES THE USE OF TWO OR MORE OIL TANKS (OIL DRUMS), THE SEDIMENTATION TIME NEEDS TO BE LONG ENOUGH, AND THE FILTRATION PROCEDURES ARE COMPLICATED, WHICH IS NOT SUITABLE FOR MINES AND LARGE-SCALE ENGINEERING PROJECTS THAT USE A LARGE AMOUNT OF OIL. THE PRECIPITATION FILTRATION PURIFICATION METHOD CANNOT EFFECTIVELY SEPARATE SUSPENDED WATER. WHEN THE CONTENT OF INSOLUBLE WATER IS REQUIRED TO BE LESS THAN 1000PPM AND THE FILTRATION ACCURACY IS 4-6 Μ M, IT LIMITS THE REMOVAL OF SOLID PARTICLES TO MEET THE PURIFICATION INDEX OF GB18/16/13, WHICH IS TECHNICALLY AND ECONOMICALLY LIMITED.CONDENSATION FILTRATION PURIFICATIONSOLID PARTICLE POLLUTION PURIFICATION IS A SOLID-LIQUID SEPARATION TECHNOLOGY. AS LONG AS THE FILTERING DEVICE USES SYNTHETIC FIBER MATERIAL WITH AN ABSOLUTE FILTRATION ACCURACY OF 4 Υ M AS THE FILTER ELEMENT, AND THE RATIO OF THE AVERAGE NUMBER OF PARTICLES BEFORE AND AFTER PURIFICATION IN THE UNIT VOLUME OF DIESEL (AVERAGE FILTRATION RATIO OF THE MULTI PASS TEST) Β VALUE REACHES 200, THE POLLUTION LEVEL OF GB18/16/13 CAN BE ENSURED.THE PURIFICATION OF WATER POLLUTION REQUIRES PHASE SEPARATION, WHICH POSES CERTAIN TECHNICAL DIFFICULTIES. IF A VACUUM DEHYDRATION DEVICE IS USED, THE PROCESS IS COMPLEX AND THE COST IS HIGH.THE PRINCIPLE OF THE COAGULATION FILTRATION DEVICE DEVELOPED BY COMPANIES SUCH AS ALLEN&CO. IN THE UK AND FADI IN GERMANY IS AS FOLLOWS: WHEN SUSPENDED WATER IN DIESEL PASSES THROUGH A HYDROPHILIC FIBER FILTER, IT WILL ADSORB, COLLIDE, AND CONDENSE INTO LARGER FREE WATER DROPLETS. WHEN FLOWING UNDER LAMINAR FLOW CONDITIONS, MOST OF THE FREE WATER WILL SETTLE QUICKLY, AND A SMALL AMOUNT OF NON SETTLED FREE WATER CAN BE EFFECTIVELY SEPARATED FROM OIL AND WATER BY HYDROPHOBIC SEPARATION THROUGH A PTFE MATERIAL SEPARATION NETWORK, ENSURING THAT THE WATER CONTENT OF DIESEL IS LESS THAN 0.1%.THE PURIFICATION SYSTEM OF KAPLER COMPANY IS SHOWN IN FIGURE 2. THERE ARE FOUR SPECIFICATIONS FOR THIS TYPE OF SYSTEM: ****** FUEL FLOW RATE OF 1136L/MIN AND 757L/MIN, WHICH ARE SUITABLE FOR FAST GAS STATION OPERATIONS, AND 379L/MIN AND 190L/MIN, WHICH CAN BE USED AS CONVENTIONAL OIL TANK FILTRATION DEVICES OR MANUALLY REFUELED ON FUEL TRUCKS. SEVERAL SMALL DOMESTIC DIESEL PURIFICATION DEVICES ARE SHOWN IN FIGURE 3.INTERNAL PURIFICATIONBOTH THE HOST MANUFACTURER AND ENGINE MANUFACTURER PROVIDE DETAILED OPERATIONAL REQUIREMENTS FOR FUEL SYSTEM SPOT CHECKS AND PERIODIC INSPECTIONS IN THEIR RANDOM USE AND MAINTENANCE INSTRUCTIONS. THERE ARE SEVERAL ISSUES THAT REQUIRE THE MANUFACTURER'S TECHNICAL SERVICE PERSONNEL TO REMIND USERS TO PAY ATTENTION.BREAK THE BAD HABIT OF REFUELING IN THE MORNINGADDING DIESEL FUEL AFTER FINISHING HOMEWORK EVERY DAY CAN REDUCE THE STORAGE SPACE OF THE FUEL TANK, AVOID THE CONDENSATION OF WET WATER IN THE AIR INSIDE THE TANK INTO WATER DROPLETS DUE TO THE TEMPERATURE DIFFERENCE BETWEEN DAY AND NIGHT, AND ALSO ALLOW TIME FOR IMPURITIES AND MOISTURE TO SETTLE IN THE DIESEL FUEL TANK (SEE FIGURE 4). IT SHOULD BE DONE EARLY THE NEXT DAYDISCHARGE POLLUTANTS BEFORE STARTING WORK. IN SHORT, IT IS IMPORTANT TO DEVELOP THE HABIT OF STAYING OVERNIGHT WITH A FULL FUEL TANK.CAREFULLY SUBSTITUTE ORIGINAL FACTORY FILTERSTHE DIESEL OIL-WATER SEPARATORS, COARSE FILTERS, AND FINE FILTERS DESIGNED OR SELECTED BY THE ORIGINAL FACTORY HAVE UNDERGONE PERFORMANCE TESTS IN ACCORDANCE WITH THE ISO4020 STANDARD, INCLUDING POLLUTION LEVEL TESTS, BUBBLE TESTS, PRESSURE DIFFERENCE TESTS, MULTI PASS TESTS, WATER SEPARATION EFFICIENCY TESTS, DAMAGE TESTS, ASSEMBLY DAMAGE TESTS, PULSATING PRESSURE TESTS, AND FATIGUE TESTS.THE PERFORMANCE OF DIESEL FILTERS IS EVALUATED BASED ON THE ABOVE TEST RESULTS, INCLUDING FILTRATION EFFICIENCY, LIFESPAN, FLOW RATE, WATER SEPARATION EFFICIENCY, AND THE LEVEL OF DAMAGE PRESSURE DIFFERENCE. IF THE INSTALLATION DIMENSIONS ARE CONSIDERED INTERCHANGEABLE AND UNQUALIFIED FILTERS OR FILTER ELEMENTS ARE REPLACED, THE ORIGINAL DESIGN'S FILTRATION CAPACITY AND EFFICIENCY WILL NOT BE ACHIEVED. OF COURSE, ENGINES THAT HAVE EXCEEDED THE WARRANTY PERIOD CAN ALSO CHOOSE DOMESTICALLY PRODUCED DIESEL FILTERS WITH PERFORMANCE LEVELS SIMILAR TO THOSE OF THE ORIGINAL FACTORY.