Study On Flow Characteristics Of The Calcined Petroleum Coke In Waste Heat Exchanger

The calcined petroleum coke(CPC)is petroleum coke after high temperature calcinated.It is essential material of aluminum electrolysis anode,graphite electrode used in steel producing and carburant.The calcined petroleum coke possess lots of heat.So it is of great significance to achieve efficient recycling of energy conservation of calcined petroleum coke waste heat for both energy saving and emissions reduction and improving the quality of calcined petroleum coke.In current industrial production,waste heat of the high temperature calcined petroleum coke can be recycled through high temperature calcined petroleum coke heat exchanger.The high temperature calcined petroleum coke heat exchanger consists of two parts: internal and external heat exchanger.The external heat exchanger consists of vertical tubes and diaphragm wall,and the internal heat exchanger consists of vertical tubes,and axial fins were welded in the tubes.In this paper the mathematic models of heat exchanger without fins were set up.Numerical simulation and experimental study are carried out to study the influence of the structure parameters,physical parameters of CPC and the operating parameters on flow characteristics of the heat exchanger.Using a self built visual experimental table,the influence of the physical parameters and operating parameters on the flow pattern and flow uniformity of CPC was studied.The results show that,the material flow in the heat exchanger is the whole flow within the experimental range;with the increase of particle size,the flow uniformity of CPC particles becomes worse;the flow velocity has little influence on flow uniformity.Using discrete element method the influence of structure parameters on flow characteristics of heat exchanger was studied.Firstly,a single layer particle flow model is established,and then the model is verified by experiments.N umerical simulation results show that,the material flow in the heat exchanger is the w hole flow;with the increase of the diameter of the header and the inclination of the side wall of the heat exchanger,the overall flow coefficient decreases and the flow uniformity becomes worse;the distance between the upper header and the inlet of the heat exchanger has little influence on the flow pattern and flow uniformity.It is important to study the flow of calcined coke in heat exchanger,to improve the heat exchanger and to improve the efficiency of waste heat recovery.