摘要
为了给锡铋合金/微波膨化木复合材料(WMC)作为地采暖地板基材的应用提供理论支撑,选择低熔点锡铋合金和微波膨化木为原料,通过真空浸渍方法制备填缝型WMC,采用多通道温度记录仪、恒温加热仪和红外热成像仪分析木材纹理方向、加热温度和受热面积对WMC温度变化规律的影响及原因。结果表明:不同纹理方向对WMC温度变化存在较大影响,表面温度均随加热时间的增加而提高,纵向的升温速率和降温速率最高,径向与弦向次之。加热温度越高,WMC表面温度越高,其传热性能与加热温度呈正相关,升降温速率均随加热温度的升高而加快,加热70℃时的升降温速率比30℃提高了583%和400%,温度不均匀度随着加热温度的升高而增加。随着受热面积的增加,WMC的稳定最高温度、升降温速率均略有增加。在纹理方向、加热温度和受热面积3种影响因素中,纹理方向和加热温度对WMC的温度变化影响较为明显,因此采用填缝型WMC作为地采暖用木质地板基材时,应优先考虑纹理方向和加热温度的影响。研究证明,低熔点合金(LMA)的加入提高了微波膨化木的传热性能。
The influencing factors of surface temperature change on wood substrate are the key basis for the preparation of wooden heating floor products.Tin-bismuth alloy(lead-free) is selected in this study since it is environmentally friendly and cost-efficient,and it has an excellent mechanical properties and low melting temperature(138 ℃).Wood microwave puffing treatment is an increasingly attracting technology,which can heat wood with a certain moisture content in a microwave field with a higher energy density,resulting in vaporizing moisture rapidly and causing the bulk to expand and form microscopic or macroscopic cracks.In order to provide theoretical support for the application of tin-bismuth alloy/microwave puffed wood composites as the substrate of wooden heating floor,the cracks of microwave puffed wood was filled with molten tin-bismuth alloy through the vacuum impregnation process,being named as wood-metal composites(WMC).Meanwhile,the multi-channel temperature recorder,constant temperature heater and infrared thermal imager were used to analyze three influencing factors(grain direction,heating temperature,and heated acreage) on the change law of WMC surface temperature.The results showed that the grain direction influenced the surface temperature change of WMC.The surface temperature increased with the extension of heating time.The longitudinal heating rate and cooling rate were the fastest,followed by the radial and tangential directions.Besides,the low melting point alloy(LMA) improved the heat transfer property of the microwave puffed wood.The higher the heating temperature,the higher the surface temperature of WMC,thence the heat transfer performance was positively correlated with the heating temperature.The heating rate and cooling rate accelerated with the increase of the heating temperature.In addition,the heating rate and cooling rate at 70 ℃ increased by 583% and 400% compared with 30 ℃,the surface temperature unevenness increased with the rise of heating temperature.With the increase of heated acreage,the stable maximum surface temperature,heating rate,and cooling rate of WMC were all rose slightly.Among there influencing factors,the grain direction and heating temperature had obvious effects on the surface temperature change of WMC.Therefore,when using crack-filled WMC as the substrate of wooden heating floor,the grain direction and heating temperature should be given priority.
作者
柴媛
陶鑫
梁善庆
傅峰
CHAI Yuan;TAO Xin;LIANG Shanqing;FU Feng(Research Institute of Wood Industry,Chinese Academy of Forestry,Beijing 100091,China)
出处
《林业工程学报》
CSCD
北大核心
2022年第2期52-58,共7页
Journal of Forestry Engineering
基金
中央级公益性科研院所基本科研业务费专项资金(CAFYBB2016MB001)。
关键词
微波膨化木
低熔点锡铋合金
复合材料
表面温度变化
采暖木质地板
microwave puffed wood
low melting point tin-bismuth alloy
composite
surface temperature change
wooden heating floor products
