Experimental Study On The Bubble Atomizing Small Flow Oil Gun

In the recent years, in order to reduce the cost of power generation, more and more power plants are using low quality coal as a boiler fuel as a result of sustained high coal price. However, traditional oil-fired boiler ignition has a dramatic consumption of fuel oil when igniting low quality pulverized coal, and has little effect on boiler cold start and stable combustion under low load. Therefore, a new-style boiler ignition method that has a low fuel oil consumption rate and stable combustion effect has very important realistic meaning.This paper firstly introduces several advanced low-oil-consumption ignition skills in domestic and abroad and theories of small flow oil gun atomization combustion, and then summarizes the designed atomization test rig and confined combustion test rig of small flow oil gun.An atomization characteristic test was carried out to test the heads of different structure of small flow oil gun, then determined to take 0.5mm head of small flow oil gun as the hot-state test gun head .A test was also took to analyze the impact of small flow oil gun structure, fuel oil pressure, and pressure of atomization medium flow on the flow characteristic of small flow oil gun. It was found that fuel oil pressure and spray aperture of small flow oil gun have a greatest impact on the flow characteristic. Then the air to liquid mass flow ratio was changed to see the atomization characteristic of small flow oil gun, and also the test gets a critical value of air to liquid mass flow ratio of the small oil gun in whole atomization state.There was also a combustion test of small flow oil gun under self-made confined combustion test rig to study the influence that the atomization air flow brings on stable combustion location of small oil gun and the impact of combustion air flow on the combustion flame length and color of small flow oil gun. Specific experiment results are as follows: the more the atomization air flow, the farer the location of combustion flame stability from gun sprayer and combustion flame has a best stability within 60-80mm from the fire point. and also the more the combustion air flow, the shorter the length and the brighter the color of combustion flame, Another test was done to study the combustion chamber temperature and combustion products (CO₂,CO,NO_X,SO₂,O₂) changes, analyzing the respectively impact that gas-liquid ratio, fuel consumption, combustion air flow and excess air coefficient on combustion temperature, combustion products and their distributions in combustion chamber.