Research On Emission Inventory And Test Cycle Of Typical Agricultural Machinery Diesel Engine

Diesel engine has been widely used in agricultural machinery because of its strong power and low fuel consumption.Mechanized operation has become the trend and requirement of the development of modern agriculture,which greatly improves the efficiency of agricultural production,but it also brings about environmental pollution problems.With the development of social economy,the process of Agricultural Mechanization in China has made rapid progress,but there is still a big gap compared with developed countries and regions such as Europe and the United States.Unlike the large-scale joint operation mode of agriculture in developed countries,agricultural machinery in China often works in the harsh environment with high load and high intensity,and its technology lags behind.Especially,it is generally lack of effective maintenance.The technical condition of the whole machine deteriorates seriously and the emission level is poor.Therefore,the exhaust emission of diesel engines for agricultural machinery is controlled and reduced to reduce its environmental production.Pressure is imperative.However,the cost sensitivity of agricultural machinery in emission pollution control is relatively high,and it is difficult to implement the post-treatment technology;agricultural machinery is widely used in a wide range of areas,which makes the supervision of agricultural machinery and the compulsory scrapping system difficult to implement,which all improve the difficulty of agricultural machinery emission control.In addition,for the sake of efficiency and other factors,farmers often adopt rough operation mode when using agricultural machinery,which makes the actual working conditions of agricultural machinery quite different from those of the test cycle set in the emission standard of non-road diesel engine.The applicability of the emission limit set under the test cycle condition in the diesel engine of agricultural machinery remains to be discussed.Although China's non-road diesel engine emission standards refer to EU standards,there are some problems in the specific pollution control work,such as unclear basic data,confused management system,lax environmental law enforcement and supervision.Because of the particularity of agricultural machinery and the actual situation of agricultural machinery in China,there are many difficulties and problems in the "one-size-fits-all" management of non-road diesel engine emission standards.Therefore,it is necessary to formulate emission standards for agricultural machinery diesel engines.Establishing agricultural machinery emission inventory is an important basis for analyzing air quality monitoring data,pollutant emission trend analysis,model research and formulation of relevant control strategies.In order to analyze the characteristics of pollutant emission of agricultural machinery diesel engine under actual working conditions and establish the pollutant emission inventory,the emission test of typical agricultural machinery diesel engine was carried out by using the built on-board emission testing system,and the emission factors of CO,HC,NOX and PM were calculated.The relevant parameters of the typical agricultural machinery diesel engine in China were analyzed through the research and analysis.The emission list of typical agricultural machinery diesel engines in China was estimated.The estimated results show that the total emissions of CO,HC,NOX and PM from typical agricultural machinery diesel engines in 2016 are 233.4941,62.0254,118.9278 and 169.867 million tons respectively.However,the CO,HC,NOX and PM emissions are 14.82%,14.41%,20.33% and 30.33% of the same period.It is of great significance to upgrade and effectively implement the emission standards of diesel engines for agricultural machinery in China as soon as possible and eliminate the backward agricultural machinery with high energy consumption and high emission.It is an important part of the standard making to record and refine the actual working conditions by using the working condition recorder and to formulate the emission test cycle of agricultural machinery diesel engine.This paper designs a diesel engine working condition recorder based on disPIC microcontroller,collects and records the actual operating condition information of agricultural machinery diesel engine,carries out data analysis and extraction through K-Means clustering analysis algorithm,puts forward a six-condition steady-state emission test cycle suitable for domestic agricultural machinery diesel engine,and carries out bench test verification.The results of data analysis show that the typical operating conditions of domestic agricultural machinery diesel engine are quite different from those of ISO 8178 C18.The test results of bench emission show that the comprehensive emission levels of pollutants of agricultural machinery diesel engine under actual operating conditions are significantly different from those of non-road diesel engine under standard test cycle conditions,and most of them are different.Under the circumstances,the emission level under six working conditions is worse than that under eight working conditions,which preliminarily confirms the inference that the applicability of ISO 8178 C18 working condition test cycle in agricultural machinery diesel engine needs to be discussed,and it is worth further study.This paper can provide some references for the revision of relevant emission standards and the research on emission control technology of agricultural machinery diesel engine.