Simulation Study On Operating Characteristics Of Oil Sand Fluidized Bed Incinerator

Oil sand is generated from oil production activities and mainly from the processes of oil exploitation,oil collection and transportation. According to the characteristics of the petroleum industry production in China, oil sand is a kind of waste from production as well as a kind of useful secondary resource. The fluidized bed incinerator designed by Shengli power plant, which belongs to Shengli Oilfield, has supplied a new way to realize harmless treatment of oil sand,cut down its bulk and transform it into energy. By the simulation study on the operating characteristics of the SHF20-1.3/350-YN type incinerator, this article makes a wonderful base for the design and optimum operation of incinerator.The article simply summarizes the characters, harm and processing methods of oil sand. It also introduces the operating parameters,structures and features of the SHF20-1.3/350-YN type incinerator. Then the overall mathematical model for combustion system and steam-water system of incinerator is established by using object-oriented programming method of C + + language.In this article, the model of combustion system is a one-dimensional steady model which bases on"cell". In the model,the furnace is divided into two parts: the dense zone at the bottom and the dilute zone at the upside. The dense zone is a independent cell,while the dilute zone is regularly divided into some cells along the height of the furnace. This article considers the process of gas and solid flow,fuel combustion,heat transfer and so on,and bases on the gas mass conservation,the solid mass conservation and conversation of energy,and uses"the model of cell"as a method to build conservation equation in combustion system. The steam-water system includes two mathematical models:the evaporation zone and the single-phase heat exchanger. In the whole model, combustion system and steam-water system are connected by flue gas parameters at the outlet of the furnace and heat transfer of the heating surface. Based on the model that has been built, this paper also uses C++ Builder 6 programming tool to design a software which can reflect the operating characteristics of incinerator,the sorftware is easy to operate and has a friendly interface.According to the models that have been built,this article simulates and studies the operating characteristics of the incinerator under design conditions. The results show that at the bottom of the incinerator the temperature is at a low level,it is because that the primary air is not preheated and the latent heat of water in the fuel is rather large. Meanwhile,the results also show that the concentration of O2 gradually decreases along the height of furnace and the concentration of CO2 increases along the height of furnace. At first,the concentration of CO increases,and then gradually decreases along the height of furnace.According to the models that have been built,the effects of incinerator load,excess air coefficient,fuel ratio on operating characteristics of incinerator are simulated respectively. Results show that when the load decreases the overall temperature of incinerator will decrease and the combustion condition will become worse; when the excess air coefficient increases the bottom temperature of furnace will decrease while the upside will increase;when the fuel ratio changes,the more the CWS ratio increases,the higher the overall temperature of furnace will be and the better the combustion condition will be.