Development Of Urea Pump Function Test Bench For Diesel Engine Exhaust Gas Treatment

In recent years,along with the rapid development of Chinese auto industry,the problem of automobile exhaust pollution is increasingly serious,the nitrogen oxides emitted by diesel vehicles seriously threaten our living environment and physical health.Diesel engines are widely used in medium and heavy vehicles due to their superior dynamic performance,reliability,and economy.However,the emission of nitrogen oxide emissions from diesel vehicles is close to 70% of the total vehicle emissions.Therefore,for the problem of nitrogen oxide emissions from diesel vehicles,many domestic and foreign scholars have put forward many solutions.Among them,the selective catalytic reduction(SCR)technology has become the preferred tail gas treatment technology route for domestic automobile manufacturers because its high processing efficiency and good economic efficiency.In the SCR exhaust gas treatment system,the urea pump is the core component.And the main function of the urea pump is to extract and measure the urea solution.After the injection conditions are satisfied,the urea solution is injected into the exhaust cylinder.Therefore,the reliability of the urea pump function is very important for the SCR system exhaust gas treatment effect.For this reason,this paper has designed and developed a multi-position urea pump functional test bench.The functional test bench mainly consist of an integrated frame structure,a water circulation system,a gas supply system,and an electrical connection system.First of all,the functional test bench is designed and constructed according to the functional test principle.The overall frame is made of aluminum profiles.And the water circulation system mainly provides the test solution for the function detection of urea pump.The air supply system mainly supplies compressed air to the metering pump.The electrical connection system consists of two parts,220 V AC and 24 V DC,which mainly provide the test bench with the necessary power.Secondly,according to the overall test principle of the test bench,the overall communication connection of the test bench is introduced in detail,and a detailed description of the detection and implementation methods of the supply pump and the metering pump is performed in the form of a flow chart.Thirdly,the upper computer software operating interface was designed and developed according to the testing requirements and detection features of the functional test bench.The operating interface was mainly developed with VS2012 and written in C#.Its main functions were to receive test data,store test results and display test results,etc.And according to the detection principle,the multi-thread communication of the host computer is developed and designed.Finally,the reliability of the test bench is verified by the known fault urea pump.And the calibration experiment of the metering pump is carried out and relevant conclusions are drawn.