Analysis Of Boiler Air Channel's Flow Field And Study On Measures Of Reducing Vibration And Energy Conservation

Boiler is one of key equipments in power plant; the cold air channel system will directly affect the work of boiler. Presently, there are differently extent vibration at the cold air channel system and flue of some boilers these worked many years. Especially, there are too many elbow dead angle of air channel which is vertical in and horizontal out, this causes vortex in air channel. It makes a high air speed, causes the running air channel mangled frequently, and been compelled pause to repair and weld. The vibration of the cold air channel system in boiler is a complicated problem, which relating to the knowledge of boiler elements, hydrodynamics, structural dynamics, the elements of vibration, elastic-plastic mechanics and the elements of wear and cumulative damnification etc. So it's necessary to research the vibration of the cold air channel system in power plant boiler and to get the main factors and mechanism of the vibration. Then we can take the corresponding measures to ensure the power plant boiler work safety and economically and to avoid the loss of the workers and equipments.This paper elucidates the factors and mechanism which result in vibration of the cold air channel system in detail. The status of the air channel, fan and air preheater which result in vibration are synthetically analyzed. And the main reasons of the vibration of cold air channel system which are the instability of flow and mechanism disturbance are especially analyzed.Toward to the situation of the cold air channel system vibration of Pan Gang power plant's #3 boiler, the reasons of vibration are analyzed through doing numerical simulation with the flow field of the boiler's cold air channel system, and the relevant father measures are raised, which include two aspects: firstly, there are necessary to change the strengthening rib in the ektexine of the cold air channel, and to add the transverse rectangular strengthening rib in outside of the cold air channel which manufactured by rolled angle or flat steel to increase the rigidity of the cold air channel, accordingly to increase the abilities of anti-vibration; secondly, there are also important to add the diversion boards in the proper positions of the cold air channel through doing numerical simulation, so to make the airflow of air channel and air preheat devices more homogeneous and to avoid the appearance of vortex, so to resolve the problem successfully finally. By doing this the heat transfer in air preheater will also...