With the application and promotion of large-scale biogas project, economic analysis and evaluation of large-scale biogas project are particularly important. However, the benefits of biogas project embodied in the economic, social, ecological, and many other aspects have dispersion, which leads to production decisions in a gray state and investment in conformity. In this paper, the biogas project in Zhuangda village, Zhaozhou County, Heilongjiang province is taken as an example, the supply and demand of funds in project operation are analyzed quantitatively by using system dynamics theory so as to study the economics of biogas project comprehensively, which can provide scientific guidance for evaluating the construction and operation of large and medium-scale biogas project objectively and lay a solid theoretical foundation for the commercial operation in biogas industry.

As a crucial technology of solving energy shortage and environment contamination, battery technology is increasingly paid attention to by people. Among various batteries, lithium battery and Zinc-nickel battery are the most competitive and promising ones, especially the Zinc-nickel battery, which will induce shock to current battery industry chain. Meanwhile, the drastic change of exterior environment, such as 5G, Sharing Economy, low-carbon policy, trade protectionism and covid-19 has brought huge challenge to the management of battery industry chain. In this context, this paper set up a battery supply chain, including two zinc-nickel battery manufacturers and a lithium battery manufacturer. Against the background of cooperative promotion of big data and low-carbon policy, this paper constructs a cooperative game model under non cooperative game and demand disturbance respectively, analysing and discussing equilibrium strategy of supply chain. The results show that the price set by the manufacturer increases with the improvement of its technical level when consumers are more sensitive to technical level; with the increase of the Carbon Emission Technology Renewal Coefficient, the optimal price of all the three manufacturers will drop; when the market promotion rate is in the middle range, the price of zinc-nickel battery will be higher than that of lithium battery. In the demand disturbance model, the supply chain determines different optimal prices according to the different ranges of demand disturbance.