生物質熱風爐結構特點及設計要點

新型生物質熱風爐由爐體、風管和沉降室組成(其工作過程為:在固定爐排上成都收賬生物質經爐膛一次燃燒後,未燃盡碳粒和可燃氣體隨高溫煙氣流進入副燃燒室進行二次燃燒。燃燒後成都找人公司高溫煙氣通過沉降室除塵後,供幹燥設備使用。1.1潔凈型生物質燃燒技術 目前,我國幹燥用生物質熱風爐,大都采用生物質(樹皮、廢木材等)作燃料。而生物質普遍具有含水率高、燃料尺寸變化大和灰分含量高等特點。此外,層燃爐配風不均勻、燃料不能完全燃燒、熱風爐熱效率降低等綜合因素造成對环境成都收賬嚴重污染。
The new biomass hot blast stove is composed of furnace body, air duct and settling chamber (its working process is that after the biomass on fixed grate is burned once in the furnace, unburned carbon particles and combustible gases enter the secondary combustion chamber with high temperature flue gas for secondary combustion. The high temperature flue gas after combustion is dedusting through the settling chamber for drying equipment. 1.1 Clean biomass combustion technology at present, most drying biomass hot stoves in China use biomass (bark, waste wood, etc.) as fuel. Biomass generally has the characteristics of high water content, large fuel size and high ash content. In addition, the non-uniform distribution of air, incomplete combustion of fuel and low thermal efficiency of hot blast stove cause serious environmental pollution.
實踐證明,層燃爐適用於含水率高、燃料尺寸透水地坪變化大和灰分含量高收賬生物質。所以,設計爐排時需要保證燃料成都找人公司均勻分佈,灰層能覆蓋整個爐排面。此外,層燃爐的另一項重要技術是分階段燃燒。它將燃燒區域分為初級燃燒室和二次燃燒室,分離瞭氣化和氧化階段,避免瞭二次空氣過早混合。為瞭減少紊亂、保持爐排上方燃料層的穩定,空氣與煙氣在初級燃燒室沒有得到充分的混合,二次燃燒室的結構和二次空氣的噴入方式應盡可能地保證煙氣和二次空氣良好的混合。煙氣與二次空氣混合得越充分,完全燃燒所需的過量空氣系數就越小,效率則越高。同時二次風以較高的速度噴入,混合效果良好, 燃燒室最好采用旋風來實現充分混合。
Practice has proved that the stoker furnace is suitable for biomass with high moisture con环氧地坪tent, large fuel size and high ash content. Therefore, when designing the grate, it is necessary to ensure the uniform distribution of fuel, and the ash layer can cover the entire grate surface. In addition, another important technology of staged combustion furnace is staged combustion. It divides the combustion area into primary combustion chamber and secondary combustion chamber, separates the gasification and oxidation stages, and avoids premature mixing of secondary air. In order to reduce the disorder and maintain the stability of the fuel layer above the grate, the air and flue gas are not fully mixed in the primary combustor. The structure of the secondary combustor and the injection mode of the secondary air should ensure the good mixing of the flue gas and the secondary air as far as possible. The more fully the flue gas is mixed with the secondary air, the smaller the excess air coefficient required for complete combustion and the higher the efficiency. At the same time, secondary air is injected at a higher speed, and the mixing effect is good. It is better to use cyclone in combustion chamber to achieve full mixing.
1.2生物質熱風爐的結構和特點 生物質熱風爐設計必須采用適合於生物質燃料的結構和措施。在設計中采用逆流燃燒方式,即燃燒火焰方向與進料方向相反,這種燃燒方式使熱煙氣流經過濕燃料表面,促進瞭燃料的幹燥和水蒸氣輸送,使燃料易於著火。同時二次風以較高的速度沿著圓形爐墻切向噴入,旋風保證煙氣和二次空氣良好的混合,延長瞭未燃盡碳粒在爐膛的滯留時間。在爐膛後部設置副燃燒室,使爐膛內未燃盡碳粒和可燃氣體完全燃燒,減少瞭高溫缺氧不完全燃燒所產生的黑煙。燃燒後的高溫煙氣在經過沉降室來進一步捕捉煙塵,降低瞭煙氣中的含塵量。在配風方面,由於熱風爐後部配有引風機,爐膛燃燒方式為微負壓燃燒,一次空氣通過爐排下的爐渣室吸入,二次空氣通過高壓鼓風機沿兩側風管切向噴入爐膛。這樣既有效地控制強風將爐排上的飛灰和未燃盡的碳粒吹走,又保證瞭生物質燃料完全燃燒所必須的大量空氣。 由於上述技術和措施,所設計的熱風爐燃燒效率明顯提高,燃料的消耗量與常規熱風爐相比節約10%左右,而且冒黑煙的頻率明顯減少,達到瞭潔凈 燃燒的目的 。
1.2 The structure and characteristics of biomass hot blast stove The structure and measures suitable for biomass fuel must be adopted in the design of biomass hot blast stove. In the design, counter-current combustion mode is adopted, that is, the direction of combustion flame is opposite to the direction of feed. This combustion mode makes hot smoke flow through the surface of wet fuel, promotes fuel drying and water vapor transportation, and makes fuel easy to ignite. At the same time, secondary air is injected tangentially along the circular furnace wall at a higher speed. The cyclone ensures a good mixing of flue gas and secondary air, and prolongs the retention time of unburned carbon particles in the furnace. A secondary combustion chamber is installed at the rear of the furnace to make the unburned carbon particles and combustible gases completely burn in the furnace, thus reducing the black smoke produced by incomplete combustion under high temperature and anoxia. The high temperature flue gas after combustion is further captured by the settling chamber to reduce the dust content in the flue gas. In the aspect of air distribution, as the back of the hot blast stove is equipped with induced draft fan, the combustion mode of the furnace is micro-negative pressure combustion. The primary air is inhaled through the slag chamber under the grate, and the secondary air is injected tangentially into the furnace along both sides of the air duct through the high-pressure blower. In this way, not only the fly ash and unburned carbon particles on the grate are effectively controlled by strong wind, but also the large amount of air necessary for the complete combustion of biomass fuel is guaranteed. As a result of the above technology and measures, the combustion efficiency of the designed hot blast stove is obviously improved, the fuel consumption is about 10% less than that of the conventional hot blast stove, and the frequency of black smoke is obviously reduced, thus achieving the goal of clean combustion.