Analyse And Design On Low Temperature Waste Heat Power Generation Thermal System Used In Cement Kiln

At present, our country has large amounts of low temperature waste heat resources in cement industry, and the heat of this part of the waste heat resources are around a third of cement production system. If they are emissioned directly, it will cause serious energy waste. Take advantage of this part of waste heat resources by applicating low temperature waste heat power generation technology of cement kiln, and produce steam to power generation, which will increase energy efficieney of the cement enterprises greatly. Therefore, setting up a complete low temperature waste heat power generation system for cement clinker production is of great significance in cement industry.By referring to the related literatures, this paper gives an overview of the waste heat resources in our country industry firstly. Especially, this paper focuses on recovery of waste heat from cement industry, introduces the development of the cement kiln low temperature waste heat power generation technology, and analyses the existing problems of it, which leads to the study of the cement kiln waste heat power generation system engineering design project.Secondly, a detailed summary and comparison is made in three kinds of cement kiln waste heat power generation thermal system, which are the single pressure system, the dual pressure system and the compound flash steam system. The system is divided into three subunits. According to the second law of thermodynamics, establish the exergy balance model and analyse the exergy flow of the system. Descripte and analyse performance of the waste heat power generation thermal system.Then design the waste heat power generation, including the design and selection of the thermal system, the utilization way of the kiln head and preheater waste heat resource, the calculation and selection of the waste heat boilers and auxiliary equipment and so on. This paper adopts dual pressure steam system and compound flash filling system for the design of the thermal system, establishs the mathematical model of the waste heat recovery, and compiles the computer program for the calculation of waste heat boilers. By debugging and running the program, we get the parameters of two kinds of thermal system design scheme. According to the established exergy balance model, calculate and analyze the exergy flow of two thermal systems, and compare the performance parameters of them. As a result, the compound flash heating system is more suitable for this cement clinker production line. Select other equipments for this thermal system.Finally, the author carries out the technical economy calculation and analyse for the engineering design project of the cement kiln waste heat power generation system. The power from waste heat power generation system can meet the electricity demand of all equipment of the cement clinker production line in the coment plant. Through the invenstment estimate of the design projects and recovery efficiency calculation shows that, the construction of the waste heat power generation system can bring huge economic benefit and energy benefit for the cement enterprise, and waste heat power generation system will not bring such problems as environmental pollution produced by coal-fired power plants. All in all. the social and environmental benefits generated by this cement kiln waste heat power generation project are very obvious.