The Study For Reasons And Countermeasures Of Ash Fouling On Furnace Arch Surface In Coal-Fired Boilers

Ash fouling on boiler heat exchange surface especially furnace arch are common phenomenons in fossil fuel fired power plant. We need to know the theory of ash deposition enough and find out the truth of it. It's very necessary for us to do this if we want to reduce the expense because of ash fouling and enhance the capability of security and improve economic efficiency of the boiler.This thesis focuses on probing into reasons of ash deposition on furnace arch surface in coal-fired utility boiler and finding out how to solve the problem. A lot of the work is based on the No.9 boiler in Baling Petroleum and Chemical Co., Ltd. The problem of No.9 boiler is that ash deposition and slagging especially ash deposition on furnace arch surface are serious. The thesis analyses what lead to fouling and indicates the specific reasons through computer simulation and the operation of the monitoring process and calculation with parameters. And the thesis points out: first, furnace arch's existence in this type of boiler itself would lead to ash fouling; and second, boiler can not run at full capacity in long period of time, and the speed of the gas flowing in the boiler flue is uneven, that increase deposition; third, the device of acoustic soot blower that has been installed can't be competent for the work because of its lower energy. This paper researches and makes three sets of project options to solve the problem. After investigating and researching a variety of sootblowers' advantages and disadvantages on using situation, the paper proposes the last program which is to install combustion gas-pulse shock wave soot-blower and that is the optimal project.The study of this thesis has practical significance to avoid or mitigate the failure of boiler because of ash fouling on furnace arch surface.