This project belongs to the field of modern transportation technology. Shangchai Company's SC8DT/9DT series natural gas engines keep the main structure of the original diesel engine unchanged, and have made major improvements in combustion methods and control technology to meet the new national emission standards; In terms of industrialization, an industrialized production line with an annual production capacity of 15000 units has been formed (in 2012).

1. Project background
   With the rapid development of my country's economy, environmental pollution problems have become increasingly prominent. Especially in recent years, severely polluted smog weather has appeared in major large and medium-sized cities, which has adversely affected people's health and also damaged my country's national reputation. Natural gas engine plays a significant role in purifying vehicle exhaust, and is a mature alternative fuel for petroleum, so natural gas vehicles are recognized as a good choice for future urban bus power.
   With the improvement of infrastructure such as domestic gas pipelines and gas stations, the rapid development of natural gas vehicles in China has a basic guarantee. In addition, the natural gas hardware facilities in Southeast Asia and the Middle East continue to improve, and the import demand for natural gas engines is expanding. Therefore, the demand for natural gas engines at home and abroad will have a very broad growth prospect in the next few years. It is estimated that the demand for Shangchai D series natural gas engines will exceed 5000 units per year in the next few years.
2. Project content
   This project draws on the current international advanced gas engine production and manufacturing technologies, and uses various advanced technologies such as electronically controlled injection, lean combustion, self-learning closed-loop control, supercharged intercooling and catalytic conversion technology to develop a vehicle that meets the national IV emission standard. Electronic-controlled single-fuel natural gas engine.
   Specific technical route: On the basis of simulation calculations, optimize the design of CNG engine cylinder heads, combustion chambers, etc., adopt supercharged and intercooling technology to reduce the intake air temperature, and accurately control the air-fuel ratio through optimal matching of the electronic control system to improve the engine's response characteristics and fuel economy. Sex; Through adjustment tests of the precious metal formula of the oxidation catalyst, a new post-processor plan is determined to further reduce the emissions of HC and CO gas pollutants to meet the National IV emission standards; Develop vehicle matching functions, use CAN bus technology to achieve gas consumption display and maximum vehicle speed control, and optimize vehicle calibration and fault diagnosis calibration.
3. Main technological innovation points
   (1)Optimize the design of combustion components such as pistons of natural gas engines to extend the service life of pistons; apply for a patent, authorization number ZL2011 20245809.2;
   (2)According to the emission requirements of the fourth country, research on matching and aging of post-treatment components was carried out; and a patent was applied, with the authorization number ZL2009 20210297.9;
   (3)Optimize and match natural gas engine superchargers to improve low-speed torque and responsiveness;
   (4)Add functions such as vehicle CAN bus, door lock control and maximum speed limit;
   (5)Optimize vehicle calibration technology and vehicle inspection and evaluation methods. Design new testing equipment and apply for a patent, authorization number: ZL2010 20237365.3;
4. promotion and application
   Shangchai Company's D series natural gas engines have been distributed in Chengdu, Shijiazhuang, Yinchuan, Xi'an, Changsha, Wuhan, Chongqing, Fuzhou and other domestic large and medium-sized cities and regions; in the international market, Shangchai's III/IV natural gas engines have taken the lead in passing the certification of the Ministry of Transport of Thailand. They can adapt to the local temperament with low CH4 content and high environmental temperature and humidity. Users have responded well and the market is growing rapidly.
5. economic and social benefits
   Since 2009, Shangchai Company has sold more than 6000 natural gas engines with national IV emission standards, with revenue of approximately 440 million yuan and new tax revenue of approximately 39 million yuan, creating a large amount of profits for the company and becoming a new profit growth point for the company. The application of Shangchai National IV emission natural gas engines has greatly reduced the emissions of harmful substances such as CO, CH and NOx, and reduced the country's dependence on oil to a certain extent. At the same time, Shangchai insists on independently developing new products, which can improve the international competitiveness of my country's automobile products.