低温热解生物质与煤共燃的结渣、积灰和磨损特性分析

Research on co-firing of biomass with coal(part three):analyse of slagging, fouling, and abrasiveness performances

利用灰分的结渣性指数 t2 、B/A、S/A、G ,积灰沾污特性指数Hw 和磨损指数HM 对低温热解生物质单燃和与煤共燃时的结渣、积灰和磨损特性进行了研究和分析。认为 :(1 )低温热解生物质 (锯屑、谷壳和花生壳 )都不适合在电厂锅炉中直接燃烧。(2 )热解生物质与煤共燃时的结渣、积灰和磨损特性取决于热解生物质灰分含量、灰成分 ,煤的灰分含量、灰成分以及混合比例等因素。(3)三种热解生物质与煤共燃能够改善它们的结渣、积灰沾污和磨损性能 ,但又增加了煤的结渣、积灰沾污和磨损性。(4 )热解生物质灰分含量越低 ,煤的灰分含量越高 ,煤的结渣、积灰沾污性能越好 ,越有利于提高混燃比例。(5 )三种热解生物质中 ,热解锯屑与煤可混性最好 。

Employing slagging index \$t\-2、B/A、S/A、G, \$fouling index Hw and abrasiveness index HM, this paper analyzes the slagging, fouling, abrasiveness performances of low\|temperature pyrolyzed biomass and co\|firing it with coal. It suggests: (1) Three kinds of low\|temperature pyrolyzed biomass (sawdust, rice hull and peanut shell) are not appropriate for direct combustion in the boiler of power plant. (2) The slagging, fouling and abrasiveness performances of co-firing low-temperature pyrolyzed biomass with coal depend on the ash content, the ash component of them and their blending rate, etc. (3) Co\|firing the three pyrolyzed biomass with coal will improve the performance of the pyrolyzed biomass in slagging, fouling and abrasiveness but will deteriorate the coal's performance in these aspects. (4) The coal will reveal a better performance in slagging and fouling and be propitious to increase co\|firing proportion, if lower content of pyrolyzed biomass ash and higher content of coal ash are availed. (5) Comparing the three pyrolyzed biomass, due to its low ash content, pyrolyzed sawdust has the best mixability with coal and the blending rate with the two coal samples can reach 3∶7 without serious slagging and fouling problem; blending pyrolyzed rice hull with the two coal samples will reduce the rice hull's abrasiveness but lead to serious slagging trend; pyrolyzed peanut shell has a good mixability with long flame coal because the ash content of the latter outweighs that of the former; when blended with anthracite, the blend will reveal a serious fouling trend for their approximate ash contents.