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Beijing releases and implements three local standards for heavy vehicle emission pollution control "NOx rapid detection method"

Publisher:DTS   Release time:2020-03-24
In order to control the emission pollution of nitrogen oxides (NOx) of heavy vehicles, the Beijing Municipal Government has recently approved and released three local standards for the emission control of heavy vehicle emissions, namely: "Quick Test Methods and Emission Limits of Nitrogen Oxides of Heavy Vehicles" (DB 11/1476-2017) (hereinafter referred to as "NOx rapid detection method"), "Limits and Measurement Methods of Heavy Vehicle Exhaust Pollutant Emissions (OBD Method Stages IV and V)" (DB 11/1475-2017) (below Referred to as "OBD Method" and "Limits and Measurement Methods for Heavy Vehicle Exhaust Pollutant Emissions (Vehicle Method Stage IV, V)" (DB 11/965-2017) (hereinafter referred to as "Vehicle Method"). Among them, the two standards "on-board method" and "OBD method" are mainly used for production and sales of heavy-duty vehicle emission inspections. Automobile manufacturers must strictly comply with the standards to produce and sell vehicles that meet the standards; "NOx rapid detection method" is mainly used in-use For the inspection of NOx emissions of heavy vehicles, owners need to do daily maintenance. The promulgation and implementation of the three standards will improve the vehicle emission control level and emission stability of heavy-duty automobile manufacturers, and improve the ability of in-use vehicles to meet regulatory standards.

  Scientific research shows that NOx pollution from heavy vehicles is the main source of pollution from motor vehicles. Beijing’s heavy vehicles account for about 4% of the city’s motor vehicle ownership, but its NOx emissions account for more than 50% of the total motor vehicle emissions. Coupled with the entry of heavy vehicles from other ports into Beijing and transit, the pollution is serious. Heavy vehicle emission pollution control has become the focus of the city's motor vehicle emission pollution control. The three standards released this time will become the main basis for heavy vehicle NOx emission enforcement.

  The first to formulate the "NOx rapid detection method" standard

   "Nox rapid detection method" local standards have been implemented on December 1 this year. At present, most heavy vehicles with emission standards of National IV and above are equipped with a selective catalytic reduction system (SCR system). To ensure the normal operation of the system, users must regularly add car urea solution (that is, the NH3 concentration is about 30%) Ammonia solution), this solution chemically reacts with nitrogen oxides to generate nitrogen, thereby reducing nitrogen oxide emissions. However, through the previous law enforcement inspection, it was found that some vehicles currently have abnormal additions and use of car urea solution; through the analysis of the added records, it is also found that some vehicles have very little consumption of car urea solution, which is insufficient to deal with nitrogen oxidation Pollutant emissions.

  After investigation, there is no international standard for rapid detection of NOX in heavy vehicles. In response to the existing problems, in order to control the pollution of NOX emissions from heavy-duty vehicles in use, our city first formulated this standard. The standard stipulates the detection methods and emission limits of nitrogen oxides. It mainly includes two fast NOx detection methods, on-site detection method and online detection method, which are used for law enforcement such as road inspection and household random inspection. At the same time, the standard specifies that the NOx emission limits of heavy vehicles in use in the fourth, fifth and sixth stages are less than 1250ppm, 1000ppm and 550ppm respectively. The standard will make up for the gap in the rapid detection of NOX emissions of heavy-duty vehicles in use.

   "OBD Method" puts forward detailed requirements for the OBD system that heavy vehicles should meet

   "OBD Method" local standards were implemented on December 20 this year. At present, heavy vehicles with emission standards of National IV and above all have an on-board diagnostic system (OBD). When there are problems with the vehicle's emission control system components, the vehicle's OBD system automatically alarms, limits engine power, and prompts the driver to repair in time vehicle. In order to give full play to the role of the OBD system, comprehensively discover the problems related to the emission control system, and promptly prompt the driver, our city has formulated this standard.

The standard stipulates the OBD system requirements that should be met when the heavy-duty vehicles are shipped from the factory, including the OBD system monitoring vehicle emission limits and measurement methods, and related technical requirements, such as after the vehicle emissions exceed the limit, the OBD system alerts the driver of the specific Methods and specific values for vehicles to limit engine power have been detailed requirements, in order to further prompt drivers to repair the vehicle as soon as possible, to ensure that vehicle emissions are stable and meet the standards. At the same time, the standard specifies a specific list of vehicle sensors or parts directly or indirectly related to excessive emissions. When a vehicle has an emission problem, the system will generate a fault code and store it in the OBD system. This cannot be cleared without maintenance. error code. At that time, through the OBD system test tool, you can read the vehicle emission problem type. In addition, the standard stipulates that heavy vehicles should have online automatic monitoring functions for emissions and energy consumption to achieve real-time management of NOx emissions.

  Revised and improved the "vehicle method" for practical problems

  The local standard of the "vehicle method" was implemented on December 20 this year. In 2013, our city formulated and implemented the local standards for the "vehicle method (2013 version)", which stipulates the NOx emission limits that should be met when the heavy-duty vehicles are sold on the factory. The heavy-duty vehicles can be tested in the laboratory or on the actual roads to control heavy-duty vehicles. Car emission pollution provides a basis. During the implementation process, it was found that the method has some shortcomings: if the test is long, it needs to be continuously tested for 8 hours; the test conditions are inconsistent with the actual operation of the vehicle, and the test requires that the maximum speed needs to reach more than 90km; the single emission of pollutants is only specified. NOx emission limits, etc.

In order to test the emission pollution of heavy vehicles more quickly and accurately, after a lot of tests and expert demonstrations, our city revised the local standard of the new version of the "vehicle method". First, the test time was shortened to 3 hours; second, the test conditions were adjusted to increase the vehicle speed. Modify it to be closer to the actual road speed; third, set the corresponding NOx emission limit of the heavy-duty diesel vehicle according to the National Five engine emission control limit requirements, and increase the carbon monoxide (CO) emission control requirements.

  Through the implementation of the above standards, it will improve the vehicle emission control level and emission stability of heavy-duty automobile production enterprises, and improve the regulatory ability of in-use vehicles to meet the standards. After the implementation of the standard, heavy vehicles selling vehicles in Beijing must strictly comply with the requirements of the standard to produce and sell vehicles that meet the standards, and reduce heavy vehicle emissions from the source. Owners need to strengthen the maintenance of in-use vehicles to ensure compliance. The city's environmental protection department and various relevant departments will conduct inspections on the emissions of heavy vehicles and vehicles in use in this city, and punish those vehicles that exceed emissions in accordance with law.

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