Calculation and practice of near-zero depth peak regulation,heat storage and release in subcritical circulating fluidized bed unit
With the rapid development of renewable energy,higher requirements are put forward for deep peak regulation of thermal power units.On the basis of subcritical circulating fluidized bed boiler(CFB)furnace fire pressure participating in near-zero depth peak regula-tion,a set of calculation method of near-zero depth peak regulation storage and release heat was established,which provided opera-tion guidance for subsequent near-zero depth peak regulation.Based on the concrete analysis of each part of the boiler with heat stor-age capacity in the process of near-zero depth peak regulation of subcritical CFB unit,a set of calculation method of heat storage and re-lease in the process of near-zero depth peak regulation of CFB was proposed,and this method was applied to the near-zero depth peak reg-ulation operation practice of a 300 MW subcritical CFB unit in Shanxi Province.By using the calculation method,it is concluded that the total apparent heat storage of boiler is 415.5 GJ,and the apparent heat storage of casting layer,metal wall,bed material carrier,soda and flue gas are 205.6,140.4,32.7,11.1 and 36.8 GJ respectively.The total heat consumption of effective work done by steam turbine is 65.2 GJ,and the heat dissipation of boiler body is 6.1 GJ.The data show the downward trend of each heat storage part with the process of near-zero depth peak regulation.This method realizes the quantitative calculation of the heat storage and release of the subcritical circulat-ing fluidized bed,guides the near-zero depth peak regulation time for the follow-up prediction,and studies the tightness and heat trans-fer characteristics of the boiler.it also provides data support for finding out how to obtain more heat storage to improve the heat storage effi-ciency and improve the performance of the boiler.
subcritical circulating fluidized bed boilernear zerodeep peak regulationheat storage and release