Factory motor vehicles refer to engineering transport vehicles such as loaders, excavators, forklifts, etc. that operate in production areas such as docks, factories, and mines. These vehicles are mainly powered by diesel engines and have a large number of vehicles. They are a major force in China's motor vehicle industry and also a major source of air pollution. As is well known, incomplete combustion and intermediate products of combustion reactions during diesel combustion, such as CO, CH, NOX, and particulate matter, are harmful. Due to the higher average air-fuel ratio of the mixture used in diesel engines compared to the theoretical air-fuel ratio, their CO and HC emissions are significantly lower than gasoline engines, their NO emissions are almost equivalent to gasoline engines, and their particulate matter emissions are much higher than gasoline engines. Experiments have shown that the particulate matter emissions of diesel engines can reach tens of times that of gasoline engines. This is also the main reason why diesel engines leave a serious impression of pollution. The Linde 351 series forklift adopts a three cylinder four stroke diesel engine, and its speed changes with the load when driving the hydraulic pump. The carbon smoke filtration device used on it can effectively reduce the emission of particulate matter from diesel engines. Its working principle is to first filter the particulate matter in the exhaust gas with a collector, and then clean the filter by oxidizing the collector. The filter is directly connected in series in the exhaust pipeline, and exhaust particles are collected through the filter core. As the working time increases, the amount of particles stored in the filter increases, and the exhaust back pressure increases. The sensor will detect whether the pressure drop of the filter is greater than the set pressure drop based on the engine operating conditions. When the triggering condition is met, the alarm light will prompt the driver to restore the filter. When the driver parks and turns off the engine, press and hold the lock switch for about 6 seconds, and the filter will automatically reset. Preheating takes about 60 seconds, combustion takes 15 minutes, and secondary air is sent into the filter by a blower to accelerate the combustion of particles inside the filter. The entire process takes about 20 minutes. After the work indicator light goes out, the forklift can continue to work. The advantage of Linde forklift's filtration device is that it has a separate combustion chamber, so there is no problem of cracks and melting caused by the heat released by particle combustion during reduction. However, due to the fact that the device only has one filter and exhaust side channel, the filter must be restored after shutdown.
Since 2000, China has implemented GB17691-1999 "Limits and Testing Methods for Exhaust Pollution Emissions from Compression Ignition Engines and Vehicles Equipped with Compression Ignition Engines". Clear regulations have been established on the emission limits of gaseous and particulate pollutants from compression ignition engines. According to foreign experience, adopting turbocharging and intercooling technology in diesel engines is a shortcut to improving their emission conditions. In addition, the electronic control common tube injection technology, due to the use of high-pressure injection, precise injection time and injection quantity control, can optimize the combustion process, resulting in significant improvements in comprehensive performance indicators such as engine fuel consumption, smoke, noise, and emission purification. As for domestically produced motor vehicles in China, their technological content is relatively low, their operating conditions are poor, and the application of new technologies is slow. With the further enhancement of human environmental awareness, the exhaust purification technology of motor vehicles in the factory should also be in line with the world, accelerate the development and utilization of new technologies, and return a clean earth to humanity.
