Emulsified Heavy Oil Stability And Combustion Characteristics Of The Experimental Study

With the fast development of the world economy, energy consumption of human increases day by day, while the environment protection rule is becoming more strict, energy saving and emission reduction becomes a worldwide topic. Therefore, developing clear energy and combustion technology of energy saving and emission reduction is a crucial task to solve those problems, and it will be a long-term fundamentality mission in the development plan of our country.As the important strategic energy, heavy-oil takes a vital role in society economy development. Emulsified heavy-oil is a energy saving and environmental protection fuel. In the combustion of emulsified heavy-oil, bead contained in oil globelet vaporizes rapidly and expands sharply, then, micro-explosion happens to oil globelet and second atomization comes into being.In this process, oil globelet gets finer which can improve the contact area between oil globelet and combustion-supporting air, and then it can reduce the degree of incomplete combustion and flue gas loss. Combustion efficiency can be improved and NOX, SO2, et al harmful gas can be reduced by the means of emulsified heavy-oil application. Heavy-oil emulsification technology can contribute a lot in lightening energy crisis and environment improvement, which attracts more and more attention.In this paper, new emulsifier was prepared, united emulsification technique was introduced to intensify emulsification by the means of ultrasonic and mechanical stirring. Stability time and dispersity of heavy-oil with new emulsifier were studied, and combustion property was investigated on an isolation method designed combustion test apparatus.Effects of emulsifier type, emulsifier content, percentage of water added (PWA), mixing rate, emulsification time and temperature on stability were studied using high temperature standing analysis method. Effects of ultrasonic power, ultrasonic frequency, emulsification time and temperature on dispersity were studied on the basis of Sauter Mean Diameter (SMD) calculation. Furthermore, ultrasonic emulsification and united emulsification techniques were compared.The results show that united technique could achieve a better emulsification effect. The optimization experiment result at different emulsification technique are TS-2 emulsifier, emulsifier content 0.2%, PWA 15～20%, mixing rate 700～900rpm, emulsification time 30min, emulsification temperature 70～80℃, ultrasonic power 500～600W, and ultrasonic frequency 25-40kHz. Based on the properties of viscosity, oil-saving rate, combustion product composition, the following conclusion was worked out:viscosity of emulsified heavy oil decreases with the increasing of emulsification temperature, and increases with the increasing of PWA, because more finely dispersing phase enhances viscosity. With the increasing of PWA, oil-saving rate first increases and then decreases. A higher temperature is favorable for oil-saving rate but not all the time, oil-saving rate is high up to 11.60%. With the increasing of PWA, NOx and SO2 concentration increases, and dust concentration first increases and then decreases. NOx concentration increases with the air excess coefficient a, but SO2 concentration decreases. Consequently, optimization combustion effect can be achieved according to the related experiment data.