Recently, at the Yulin Science and Technology Work Conference in 2009, six projects including "Research on the use of residual heat of aging heat treatment for castings such as engine blocks and cylinder heads" and "YC6J-30 Diesel Engine Project" of Yumai Diesel Machinery Co., Ltd. were included. Won the first prize of the 2008 Yulin Science and Technology Progress Award. "Utilizing engine block, cylinder head and other castings residual heat aging heat treatment process research" is the comprehensive utilization of waste heat and other new technologies, new equipment development projects. In April 2009, China's invention patent was granted by using the residual heat of castings to reduce the residual stress of castings. From March 2005 to January 2009, the company’s new casting workshop produced more than 140,000 tons of castings, saving more than 14.08 million kWh of electricity, equivalent to about 5014 tons of standard coal, and reducing SO2 emissions by about 100 tons, reducing CO2 emissions. About 1,103 tons of emissions, significant energy-saving emission reduction effect. At present, Yuchai Foundry Center and several well-known domestic engine factories have applied this technology. YC6J-30 diesel engine has good dynamic performance and economical efficiency. It has reached the national standard of 3, and its emission level is in the leading position in the domestic medium-sized diesel engine of the same kind. It has good social and economic benefits.