Research And Improvement Of The SCR Exhaust Temperature Sensor For Commercial Vehicles

With the rapid development of economy,the living standard of modern peopl e is getting higher and higher.The increasing demand for materials has helped to increase the demand for commercial vehicles,which mainly transport goods,and thus aggravate the pollution of people's living environment.In order to better protect our living environment,at the same time,to meet the increasingly stringent regulations on automobile exhaust emissions,major auto companies stepped up their efforts to the study of automobile exhaust after-treatment technology.And the temperature is the important index to control the automobile exhaust.Only when the temperature reaches the specified temperature,it is transmitted to the on-board computer through the signal,and the corresponding command is issued by the on-board computer so that the urea solution is ejected in an appropriate amount and combined with the nitrogen oxides in the exhaust gas to generate harmless nitrogen and water.If the temperature does not meet the requirements,the reaction rate will slow down,and this will impair the activity of the catalyst.Therefore,the SCR exhaust after-treatment system needs to monitor the exhaust temperature in real time,and timely transfer the corresponding data to the on-board computer,so as to facilitate the on-board computer to make a judgment.The measurement range of the SCR exhaust temperature sensor needs to be between-40°C and 800°C,and its reaction time is required to be less.At the same time,due to the relatively harsh environment and the relatively complex working conditions in which the commercial vehicle is used,it requires good mechanical properties to meet the measurement requirements under complex conditions.At this stage based on the research and analysis of the exhaust gas temperature sensor provided,we have tried to research and develop an SCR exhaust temperature sensor that is more suitable for the commercial vehicles.The sensor uses Pt200 platinum resistance as the measuring element of the temperature sensing probe and is wrapped with aluminum oxide as the insulating material,the M14*1.5 SW16 type hollow hexagonal progressive bolt is used as the fixing nut and the flame-retardant rubber protective sleeve is added,which could help to improve the product structure performance,shorten the product reaction time,enhance the product reaction sensitivity,and extend the product life.This will reduce the maintenance costs of the market customers,and at the same time facilitate the production and installation of vehicle manufacturers.This article introduces the current type of temperature sensor and its development history.It mainly elaborates the design concept,process improvement and subsequent experimental verification content of the improved SCR exhaust temperature sensor for commercial vehicles.At present,the improved SCR exhaust temperature sensor for commercial vehicles has been put into trial production models in small batches.Although the actual data collected is slightly different from the data obtained from the simulation environment in the laboratory.However,as a whole,the results are relatively satisfactory,can meet the requirements of the current market customers and vehicle manufacturers,and can be guaranteed to apply to the current automobile exhaust emissions laws and regulations.At the same time,this improved commercial vehicle SCR exhaust temperature sensor has a certain technical and technological forward-looking,adapts to its development trend,and is able to better serve the market customers and vehicle manufacturers.