Experimental Study On External Heat Exchanger In Oxygen-enriched Circulating Fluidized Bed

The large-scale of circulating fluidized bed under the control of the arrangement ofheating surface, so the external heat exchanger as an important way to solve thelarge-scale which has huge value. In order to control greenhouse gas of CO2emissions,fluidized bed combustion oxygen-enriched combustion technology has its remarkableadvantage. But because of the change of combustion atmosphere, the problems ofarrangement of heating surface have higher request. The development of the externalheat exchanger become an important research work of fluidized bed boileroxygen-enriched combustion.This paper is about setting up an Oxygen-enriched combustion circulatingfluidized bed system which has an external heat exchanger through the study forexisting external heat exchanger and has carried on the certain innovation improvementin the structure, the whole test bench has the function of grey tap back. This paperintroduces the structure of the test bench,the function and parameters andcomponents.This experiment study the influence of different heat transfer coefficient forthe whole test-bed. Mainly ensure the parameter values in which the test bench can runnormally in the cold test process, and then choose the suitable parameter values forsome hot state experiments, and the test results contrast with the theoretical results wereanalyzed.Through a series of experiments,it can be learned that because of the addition ofemulsion phase, gas-solid two-phase heat transfer ability is higher than that of a singlegas phase,so the heat transfer coefficient is greater than the single did not join the greymaterial in high temperature gas heating when join the gas;at the same time, Withoutchanging EHE midstream and air volume, under the condition of fluidization windtemperature, along with the rising of the ash air volume in the preheater, the heattransfer coefficient decreases in EHE. Due to the internal structure changes in EIE andthe different way of the coil configuration make the grey material in EHE trajectoryand time changes, leading to the different between the different of coil heating surfaceheat transfer coefficient; on this basis,this paper also discusses the design andcalculation method of the external heat exchanger,and compared the relevant calculationaccuracy of the model,therefore laid the foundation of the external heat exchanger forthe development of rich oxygen combustion fluidized bed.