At present,the energy efficiency evaluation of centrifugal pump units in China is still in the exploratory stage.In order to evaluate the energy efficiency level of the equipment quickly and accurately,based on the MVC model of the .NET platform,this paper designs and develops an automated evaluation system. On the basis of establishing the mathematical model of energy efficiency evaluation of pump units,the parameters are collected and processed. The data is imported manually or by accessing the database，and the energy efficiency calculation is performed according to the standard using a simple and highly accurate formula. The system is applied to verify the example，and the operating condition of the equipment is compared with the economic operation discriminate table to judge the operation of the unit. The results show that the evaluation results calculated by the software are accurate.Without complicated manual calculation,the evaluation time can be shortened,the work efficiency can be improved，and it has certain application value for industrial production.

According to different damage process of natural gas pipeline leakage diffusion problems, using FLUENT software, CFD simulation model was established, and studied the different leak diameter of the effects on gas leakage diffusion area and simulated the natural gas leak and diffusion process between mountain and city terrain. The situation of wind speed changing along with the height and mass discharge rates variable with the time were taken into account and UDFs were programmed into the FLUENT to amend them. It concluded that the bigger hold can achieve the higher range, the max lower explosive limit of the high from the ground and downwind horizontal distances of diameter of 6.35 , 25.40 mm and 101.60 mm were 92 m and 322 m,122 m and 770 m, 408 m and 1291 m. When diffuses on the surface and in the soil, the 101.60 mm leak diameter had the maximum diffusion range. The biggest downwind horizontal distances were up to 80 m and 105 m respectively. This was because the gas lost a lot of turbulent energy influenced by the soil above the pipeline.