Study On Universal Exergy Analysis Method And Its Application

Resource shortages, environmental pollution and climate issues have posed serious obstacles to world economy and social development. It's so important nowadays in the field of general energy saving and sustainable development to study on the analysis and evaluation methods of the comprehensive utilization of resources and environmental impact of social production systems, to propose the corresponding evaluating indicators, to assess overall economic efficiency and sustainability of development of the systems. For the first time, the concept of universal exergy and the universal exergy analysis method have been proposed and defined. As a result, various factors of production resources in the production system can be summed up and compared under a unified scale, so as to obtain the quantitative evaluation results for the system's comprehensive utilization of resources and the impact on the ecological environment. This is a new attempt in the evaluation methodology, as the evaluation results play an important role in optimal allocating resources, efficient utilizing various resources, optimizing energy consumption structure and changing development mode.The main works and originality innovations presented in this paper are as follows:1. The significance and roles of the concept of exergy, the models and application development of exergy analysis method were systematically analyzed, and the shortcomings of the current exergy analysis in comprehensive evaluation of a system were pointed out. However, it was emphasized that the exergy analysis method still plays an important role in guiding the technical development for the systems' energy saving and emission reduction.2. It was revealed that, the material and energy consumption and utilization process in any system, including the Earth environment, is the process of exergy consumption in nature. The fact that, it is the open Earth environment system, which continuously receives exergy (mainly solar power) from the universe to maintain the development of the Earth's natural ecological environment system and that of human social and economic systems, was discovered. Based on the limited capacity of the Earth's environment, a triangular dependence graph of the economic, social and natural environment for sustainable development was presented, and the interdependent as well as mutual-constraining relationship of the three parties was elucidated.3. Based on the economic characteristics of exergy, such as scarcity and usability, the relationship between exergy and use value was discusseed. The concept of universal exergy was proposed for the first time, and the relationships between universal exergy and value, exergy and universal exergy of commodity were depicted, and the principle of calculating the amount of universal exergy was identified, and the methods and models for calculating universal exergy of various resource elements comprising the production system, i.e., raw materials and energy resources, capital, labor and environmental cost, were established.4. Based on the concept of universal exergy, exergy analysis and exergoeconomics analysis, the universal exergy analysis method was proposed for the first time, and models for universal exergy analysis and evaluation of systems were developed, evaluating indicators such as the coefficient of utilization of universal exergy and sustainable development index were defined. A new comprehensive quantitative analysis and assessment indicator system were provided for the analysis and evaluation of the comprehensive utilization of different types of production elements, such as means of production, capital, labor and environmental resources, in the production process.5. Exergy analysis for a complicated nonferrous metal production system--SKS lead smelting system was conducted, the distribution rules of exergy losses in the entire processing of crude lead were revealed, it was found that exergy income is much greater than energy income in metallurgical production systems under the same material flow status. What's more, for metallurgical furnaces, the exergy analysis process is easier and more intuitive than that of the energy analysis. Therefore, it is proposed that exergy analysis method should be used widely in the analysis and evaluation of metallurgical production processes.6. Through the universal exergy analysis of the SKS lead smelting system, the poor sustainable development prospect of resources consumption enterprises like those majoring in metallurgical production was found. The energy-saving measures for such systems should be focused on reducing the consumption of universal exergy of natural resources, i.e., reducing the system's consumption of non-renewable energy and raw materials in the production process. In comparison, universal exergy analysis for a production system utilizing renewable energy--solar photovoltaic power generation system was conducted, and it was found that the system's sustainable development prospect is fairly good. The energy-saving measures for such systems should be focused on reducing energy consumption in manufacturing solar photovoltaic cells and reducing the installation cost of the solar photovoltaic power generation system, rather than on energy-saving in the system's operation process.