Study And Design Of Oil-Shale Semicoke Circulating Fluidized Bed Boiler

With the approaching crisis of conventional energy resources and the growingdemand for energy, many countries paid more and more attentions to oil shale richand widespread throughout the world. As China’s rapid economic development inrecent years, energy supply and demand have become increasingly prominent, it’surgent to speed up the development and utilization of oil shale resources, which canincrease the domestic supply of oil and gas resources, and will be great significanceto our energy security. Oil shale is the fossil fuel with high volatile content, low fixedcarbon content, and good comprehensive utilization level characteristics, whichdetermine that its pyrolysis and combustion characteristics are different fromconventional coal, so we need exploring characteristics and utilization technologies ofoil shale to seek how to utilize domestic oil shale resources cleanly, efficiently andeconomically.Considering oil shale basic characteristics and present situation of utilizationtechnology, a new comprehensive utilization technical route “combined system of oilshale bubbling bed retorting and semicoke CFB combustion oil refining” wasrecommended for the utilization of oil shale in the chapter2, based on thecharacteristics: gas and heat supply system, which uses bubbling fluidized bed asoil-shale retort furnace and circulating fluidized bed as semicoke combustion facility,hot ash generated by circulating fluidized bed combustion and circulating hot gas asthe heat carrier of retort furnace. This technical route realizes comprehensiveutilization of oil shale resources. The circulating fluidized bed combustionmechanism of oil shale semicoke was regarded as one of the core and primaryresearch of this paper. So the following chapters focused on the this subject.As oil shale semicoke is the oil shale distillation solid waste with the high ashcontent and low calorific value, further study on whether the oil shale could combust in the circulating fluidized bed and its combustion characteristics were essential. Thesmall-scale fluidized bed experimental device was used to carry out the combustionexperiment of oil shale semicoke in the chapter3, which can provide some guidancefor designing industrial circulating fluidized bed boiler. In the small-scale fluidizedbed device, the experiments were proceeded which consisted of the effect of fiveoperating factors on pollutants emission, including bed temperature, particle size, bedmaterial height, secondary air ratio, circulation ratio, and got the influence ofdifferent parameters on the fluidized bed pollutants emission, which can provide theexperimental data and theoretical basis for the design of oil shale semicoke industrialfluidized bed boiler.Based on the research contents given above, combined with design and operationexperiences of Huadian65t/h oil shale CFB boilers, the key technologies of oil shalesemicoke CFB boiler were analyzed, and the structure design of130t/h oil shale CFBboiler was completed for meeting the construction needs of Huadian national oil shalecomprehensive utilization demonstration base in the chapter4. The heat calculationresults show that the boiler design results are reasonable, and the design thermalefficiency of the boiler is85.81%.