| China’s consumption demand of primary energy will continue to increasein the long term, which brings new challenge to clean energy utilization andenvironmental protection. Nowadays, l000MW USC unit becomes the maindeveloping unit in our country, and it’s necessarily to focus on the developmentof700℃USC boiler with higher steam parameters. The research of couplingmechanism is the key problem on advanced USC boiler design and operation.The paper focus on the combustion, convection and radiation characteristics infurnace and heating transfer characteristics in water wall, program onMATLAB so as to get the distribution of water wall temperature. The researchachievements are listed as follows:The heat flux distribute as an arc along the width direction, higher in themiddle and lower in the tow margin. The heat flux in34m is higher than thatin54m, which shows that the radiation in34m is stronger than that in54m. the paper also analyze convection between flue gas and heater surface, the resultshows that the proportion of heat transfer by convection in furnace is far over5%, even reach a maximum22%in BMCR.For the working substance in water wall, the substance under BMCR,75%BMCR,50BMCR in600℃USC conditions experience the2-phase-region, however in700℃USC conditions, substance under BMCR doesn’thave a phase transition, there is only one phase in the tube, which shows thesubstance have finish its phase transition before getting into the water wall.The paper construct the coupling model to solve the water walltemperature, the result shows that: without the heat or flow deviation, the waterwall temperature is between534℃~619℃, the maximum is619℃, in5%security margin at design, material with permitted temperature higher than650℃is recommended for water wall tube for operating safety. With the study onheat and flow deviation, the paper recommend to make sure that no more than3m for the flame deviation and-30%for mass flow so as to prevent overheating. |
PDF Full Text Request