木材干燥试卷答案及评分标准

木材枯燥试卷1标准答案及评分标准/年度第二学期期末考试试卷名词解释〔每题3分，共15分〕1.木材枯燥：答案：在热力作用下以蒸发或沸腾的方式将木材内水分排出〔或使含水率降低到使用要求〕的过程。评分：答复内容或意义完全正确得3分；答复内容或意义不完全，得1分；不答复、答复错误或局部错误得0分。2.湿含量：答案：含有1㎏干空气的湿空气中水蒸汽的克数。评分：答复内容或意义完全正确得3分；答复内容或意义不完全、不答复、答复错误或局部错误得0分。3.纤维饱和点：答案：在大气条件下，当自由水已蒸发干净，而吸着水还保持着最高量时的木材含水率，叫做纤维饱和点或吸湿极限。评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。4.干缩系数：答案：在纤维饱和点以下时，木材的含水率每降低1%而引起木材的收缩量，叫做木材的干缩系数，简称干缩系数。评分：完全答复正确得3分；短缺“在纤维饱和点以下”得1分；不答复、答复错误或局部错误得0分。5.露点：答案：湿空气在其水蒸汽分压下所对应的饱和温度，或在湿含量不变时到达饱和所对应的温度，叫做湿空气的露点温度，简称露点。评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。填空题：〔每空1分，共20分〕答案：1.导热对流辐射2.0〔零〕3.开裂弯曲皱缩炭化变色枯燥不均翘曲霉变外表硬化〔任选7个〕4.大毛细管〔路径〕微毛细管〔路径〕混合〔路径〕5.长轴型短轴型侧风型端风型喷气型6.湿容量评分：每空按标准填写，得1分，不填、填错得0分。选择题：〔每题3分，共30分〕答案：1.C2.B3.D4.ABD5.ABCD6.C7.ABCD8.A9.B10.A评分：每题全部选对，得3分；不选、错选、选不全得0分。判断题〔每题1分，共10分〕答案：1.√2.√3.√4.√5.×6.√7.√8.√9.×10.√评分：每题判断正确得1分，判断错误得0分。简答题〔每题5分，共15分〕1.真空枯燥的原理是什么？答案要点及评分：⑴降低了水的沸点，木材外表水分蒸发加剧；·······················································1分⑵在木材中形成内高外低较大的压力差，木材内部水分移动加快；···················1分⑶形成内高外低较大的含水率梯度，木材内部水分移动加快；························1.5分⑷木材内部水分之间粘度降低，木材内部水分移动加快。································1.5分2.大气枯燥的优点有哪些？答案要点与评分：⑴技术简单，容易实施。······························································································1分⑵节约能源，经济性强。······························································································1分⑶假设工艺得当，那么木材含水率均匀，应力很小。······················································1分⑷能够防止严重的枯燥缺陷。······················································································1分⑸可保持木材的天然色泽。··························································································1分3.木材枯燥的目的是什么？答案要点与评分：⑴防止木材开裂变形；································································································1.5分⑵防止木材腐朽变色；···································································································1分⑶提高木材力学强度；································································································1.5分⑷减轻木材重量。···········································································································1分六、论述题〔10分〕画图并说明以湿空气为介质枯燥木材的枯燥过程。I〔kJ/㎏〕I〔kJ/㎏〕MMBBCøCø=1AAd〔gd〔g/㎏〕N00答案要点与评分：⑴画出上图····························································································································3分⑵状态点描述·····················································································································2.5分N为新鲜空气状态点······································································································0.5分M为新鲜空气加热后状态点·························································································0.5分A新鲜空气与废气混合后状态点··················································································0.5分B混合空气加热后状态点·······························································································0.5分C枯燥后废气状态点。···································································································0.5分⑶枯燥中各状态的变化过程·····························································································2.5分NM为新鲜空气直接加热过程······················································································0.5分AB为混合气体直接加热过程·······················································································0.5分MC为第一次枯燥过程···································································································0.5分BC为循环枯燥过程········································································································0.5分NC为新鲜空气与废气的混合过程················································································0.5分⑷△ABC为枯燥三角形········································································································1分⑸新鲜空气N加热到M，枯燥后为C，再与N混合成A，加热为B，枯燥后又为C，再与N混合成A，……，形成屡次循环。························································1分木材枯燥试卷2标准答案及评分标准/年度第二学期期末考试试卷一、名词解释：〔每题2分，共14分〕1.木材枯燥：答案：在热力作用下以蒸发或沸腾的方式将木材内水分排出的过程。评分：完全答复正确得2分；答复内容不完全，得1分；不答复、答复错误或局部错误得0分。2.平衡含水率：答案：薄小木料在一定的空气状态下到达稳定的解吸或吸湿含水率叫做该木材在这种空气状态下的平衡含水率，简称平衡含水率。评分：完全答复正确得2分；短缺“薄小木料”或“在一定的空气状态下”其一得1.5分；二者均短缺得1分；不答复、答复错误或局部错误得0分。3.枯燥基准：答案：在木材枯燥过程中按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表，叫做木材枯燥基准，简称枯燥基准。评分：能够表达出“按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表”得2分；答复内容不完全，得1分；不答复、答复错误或局部错误得0分。4.干缩系数：答案：在纤维饱和点以下时，木材的含水率每降低1%而引起木材的收缩量，叫做木材的干缩系数，简称干缩系数。评分：完全答复正确得2分；短缺“在纤维饱和点以下”得1分；不答复、答复错误或局部错误得0分。5.湿含量：答案：含有1㎏干空气的湿空气中水蒸汽的克数。评分：答复内容或意义完全正确得2分；答复内容不完全、不答复、答复错误或局部错误得0分。6.露点：答案：湿空气在湿含量不变时其水蒸汽分压到达饱和压力时所对应的温度叫做湿空气的露点，简称露点。评分：答复内容或意义完全正确得2分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。7.解吸：答案：在纤维饱和点以下时，木材失去水分的过程，叫做解吸。或木材的结合水失去的过程。或木材细胞壁内水分失去的过程。评分：答复内容或意义完全正确得2分；答复内容不完全、不答复、答复错误或局部错误得0分。8.枯燥介质：答案：在木材枯燥过程中既能够把热量传递给木材又能够把木材内蒸发出的水分带走的媒介物质，叫做木材枯燥介质，简称枯燥介质。评分：答复内容或意义完全正确得2分；答复内容不完全、不答复、答复错误或局部错误得0分。9.导热系数：答案：在木材单位厚度上温度每降低1℃评分：答复内容或意义完全正确得2分；答复内容不完全、不答复、答复错误或局部错误得0分。10.相对湿度：答案：每1m3评分：答复内容或意义完全正确得2分；答复内容不完全、不答复、答复错误或局部错误得0分。二、填空〔每空0.5分，共15分〕1.湿空气炉气过热水蒸汽2.开裂弯曲皱缩炭化变色枯燥不均翘曲霉变外表硬化〔任选6个〕3.铸铁肋型管平滑管螺旋片4.干湿球温度差5.水蒸汽压力差6.自由水结合水化合〔学〕水7.长轴型短轴型侧风型端风型喷气型8.时间含水率连续升温9.0——110.高频微波除湿太阳能红外线加压真空化学接触〔任选4个〕三、选择〔每题2分，共30分〕1.C2.C3.C4.C5.B6.D7.C8.A9.C10.B11.C12.A13.B14.C15.A四、判断〔每题1分，共15分〕1.×2.√3.×4.√5.√6.×7.√8.×9.√10.√11.×12.√13.×14.√15.√五、答复以下问题〔每题4分，共16分〕1.隔条的作用是什么？答案要点及评分：⑴在材堆的高度上形成水平循环气流通道；································1.5分⑵湿材堆在宽度方向上稳定；··············································1分⑶湿材堆中各层木料相互夹持，防止和减轻木材的翘曲。····················1.5分2.枯燥新材种的木材，其枯燥基准是如何确定的？答案要点及评分：⑴选择材性相近树种的枯燥基准进行试验、修正；····························1分⑵假设没有材性相近树种的枯燥基准，首先要进行干缩特性试验；················1分⑶小试件枯燥试验拟定枯燥基准〔百度法〕并就不同规格材对拟定枯燥基准的适应性试验及修正；····························································1分⑷中试、生产性试验及修正。··············································1分3.终了处理的目的是什么？答案要点及评分：⑴平衡整个材堆的含水率，使之均到达要求平衡含水率；······················1分⑵平衡每快板材断面的含水率，消除含水率梯度及含水率应力；··············1.5分⑶消除剩余应力，防止变形。············································1.5分4.真空枯燥为什么会提高枯燥速度？答案要点及评分：⑴真空枯燥降低了木材外表水分的汽化温度，使水分易于蒸发；················2分⑵真空枯燥降低了木材内部水分之间的粘度，使水分易于移动。················2分5.在高温枯燥过程中，为什么相对较高的相对湿度能加快枯燥速度？答案要点及评分：⑴木材枯燥的速度取决于木材内部水分的移动；······························2分⑵较高的相对湿度使木材外表湿润，表层水分移动通道加大，易于水分移动。····2分6.木材枯燥的意义是什么？答案要点及评分：⑴防止木材开裂变形；····················································1分⑵防止木材腐朽变色；····················································1分⑶提高木材力学强度；····················································1分⑷减轻木材重量。························································1分7.侧风机型枯燥室的特点是什么？答案要点及评分：⑴结构简单，容积利用系数大；············································1分⑵投资小，能耗少，安装维修方便；········································1分⑶循环不均，影响枯燥质量；··············································1分⑷每两间枯燥室之间需配管理间，生产面积利用不经济。·····················1分8.锯材堆积应注意哪些事项？答案要点：⑴同一材堆树种、规格、含水率应一致，或树种不同而材性相近；⑵隔条在材堆中自上而下保持一条线并落在支撑横梁上；⑶支撑同一材堆的支撑横梁的高度应一致；⑷木料越薄、质量要求越高或终含水率要求越低，隔条数量应越多；⑸材堆端部的两行隔条应与板端对齐。假设木料长短不一，应把短料放在中间；⑹材堆的最高两层放置低级木料，顶部放重物来防止上部木料翘曲；⑺枯燥厚度小于40mm、宽度小于50mm的毛料时，可互为隔条，不再另置隔条；⑻自然循环枯燥室，材堆内要有一系列竖直气道，每一气道应在一直线上。评分：任意答复4条，每条1分。多答不扣分。六、论述〔10分〕1.在I——D图上说明屡次循环的理论枯燥程，并说明每个过程中各状态参数是如何变化的。I〔kJ/㎏〕I〔kJ/㎏〕MMBBCøCø=1NANA0d〔0d〔g/㎏〕答案要点及评分：⑴画出上图····························································································································3分⑵状态点描述·····················································································································2.5分N为新鲜空气状态点······································································································0.5分M为新鲜空气加热后状态点·························································································0.5分A新鲜空气与废气混合后状态点··················································································0.5分B混合空气加热后状态点·······························································································0.5分C枯燥后废气状态点。···································································································0.5分⑶枯燥中各状态的变化过程·····························································································2.5分NM为新鲜空气直接加热过程······················································································0.5分AB为混合气体直接加热过程·······················································································0.5分MC为第一次枯燥过程···································································································0.5分BC为循环枯燥过程········································································································0.5分NC为新鲜空气与废气的混合过程················································································0.5分⑷△ABC为枯燥三角形········································································································1分⑸新鲜空气N加热到M，枯燥后为C，再与N混合成A，加热为B，枯燥后又为C，再与N混合成A，……，形成屡次循环。·········································1分2.论述木材枯燥过程中应力的发生开展过程。答案要点及评分：⑴木材枯燥可分为两个阶段，即自由水排除阶段和结合水排除阶段。自由水排除阶段不产生应力，只有在结合水排除阶段才产生应力。························································2分⑵枯燥开始后，在很短的时间内，木材表层含水率降到纤维饱和点以下并产生干缩，而内层却高于纤维饱和点，不发生干缩。这样内层受到表层的压缩而产生压应力，而表层受到内层的拉伸产生拉应力。····················································································2分⑶随着枯燥的进行，内层含水率也降到纤维饱和点以下并产生干缩，直到内外层之间没有相互作用止。此时虽然没有相互作用，但存在含水率梯度以及表层的剩余变形，因此存在含水率应力和剩余应力。············································································2分⑷随着枯燥的继续，内层进一步收缩，而表层因干缩变定不能收缩，致使内层受拉表层受压，因而内层产生拉应力而表层产生压应力。························································2分⑸枯燥结束后，随着木材含水率的逐步平衡，含水率梯度消除，含水率应力消失，但由于存在剩余变形，因此木材内部还存在剩余应力。····················································2分木材枯燥试卷3标准答案及评分标准/年度第二学期期末考试试卷一、名词解释〔每题3分，共15分〕1.纤维饱和点：答案：在大气条件下，当自由水已蒸发干净，而吸着水还保持着最高量时的木材含水率，叫做纤维饱和点或吸湿极限。评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。2.湿容量：答案：在一定温度下每1m3评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。3.导热系数：答案：指在木材单位厚度上的温度降低1℃评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。4.枯燥室：答案：装配有通风和加热设备，用来枯燥木材的建筑物或金属容器，叫做木材枯燥室〔枯燥窑或枯燥炉〕评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。5.相对湿度：答案：每1m3评分：答复内容或意义完全正确得3分；答复内容不完全、不答复、答复错误或局部错误得0分。空题：〔每空1分，共20分〕答案：1.大气高频微波除湿太阳能红外线加压真空化学接触炉气过热蒸汽〔任写6种〕2.微毛细管〔路径〕大毛细管〔路径〕混合〔路径〕3.过热蒸汽湿饱和蒸汽干饱和蒸汽4.称重法电测法5.弦向径向纵向〔体积〕6.湿空气炉气过热蒸汽评分：每空按标准填写，得1分，不填、填错得0分。选择题：〔每题3分，共30分〕答案：1.B2.D3.A4.A5.ABCD6.ABCD7.B8.AB9.B10.B评分：每题全部选对，得3分；不选、错选、选不全得0分。判断题〔每题1分，共10分〕答案：1.×2.√3.√4.√5.√6.√7.×8.×9.√10.×评分：每题判断正确得1分，判断错误得0分。简答题〔每题6分，共18分〕1.导热的根本定是什么？答案：单位时间内在物体内部两等温面间流动的热量Q，与垂直热流方向的断面积F和温度差△t成正比，与等温面间的距离△x成反比。即：评分：完全答复正确得6分；只有文字表达且内容或意义正确，没有公式得6分；只有公式，没有文字表达，得5分；表达不正确，不管有无公式得0分。2.木材枯燥过程中影响木材枯燥速度的因素哪些？答案要点与评分：⑴树种：不同的树种内部构造不同，纹孔数量多且不闭塞、纹孔膜上微孔数量多的树种容易枯燥。·································································································1分⑵部位：木材的心材内多有沉积物，水分移动困难，较难枯燥。·························1分⑶方向：木材顺纹方向水分移动的速度比横纹快得多，径向因木射线的存在比弦向快。·····················································································································1分⑷温度：温度高，水分移动的速度明显快。·····························································1分⑸木材的含水率：含水率的多少对木材的大毛细管系统和微毛细管系统均有影响，但二者根本可相抵。所以含水率对枯燥速度没有明显的影响。·················1分⑹介质的温度、湿度、循环速度对木材水分的移动有较大的影响。·····················1分3.木材枯燥的目的是什么？答案要点与评分：⑴防止木材开裂变形；····························································································1.5分⑵防止木材腐朽变色；····························································································1.5分⑶提高木材力学强度；····························································································1.5分⑷减轻木材重量。···································································································1.5分六、论述题〔7分〕枯燥过程中，应力是如何形成、开展的。答案要点与评分：⑴木材枯燥可分为两个阶段，即自由水排除阶段和结合水排除阶段。自由水排除阶段不产生应力，只有在结合水排除阶段才产生应力。·······················1分⑵枯燥开始后，在很短的时间内，木材表层含水率降到纤维饱和点以下并产生干缩，而内层却高于纤维饱和点，不发生干缩。这样内层受到表层的压缩而产生压应力，而表层受到内层的拉伸产生拉应力。···························2分⑶随着枯燥的进行，内层含水率也降到纤维饱和点以下并产生干缩，直到内外层之间没有相互作用止。此时虽然没有相互作用，但存在含水率梯度以及表层的剩余变形，因此存在含水率应力和剩余应力。········································1分⑷随着枯燥的继续，内层进一步收缩，而表层因干缩变定不能收缩，致使内层受拉表层受压，因而内层产生拉应力而表层产生压应力。·······················2分⑸枯燥结束后，随着木材含水率的逐步平衡，含水率梯度消除，含水率应力消失，但由于存在剩余变形，因此木材内部还存在剩余应力。···················1分木材枯燥试卷4标准答案及评分标准/年度第二学期期末考试试卷一、名词解释〔每题3分，共15分〕1.纤维饱和点：答案：在大气条件下，当自由水已蒸发干净，而吸着水还保持着最高量时的木材含水率，叫做纤维饱和点或吸湿极限。评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。2.吸湿滞后：答案：在干木材变湿过程中，吸湿稳定含水率或多或少地低于在同样空气条件下的解吸稳定含水率。这种现象叫做吸收滞后或吸湿滞后。评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。3.湿含量：答案：指在湿空气中以1㎏干空气为根底的水蒸汽的克数；或含有1㎏干空气的湿空气中水蒸汽的克数；或含有1㎏干空气的湿空气中水蒸汽的含量，以克计。评分：答复完全正确得3分；短缺“克数〔以克计〕”得2分；不答复、答复错误或局部错误得0分。4.枯燥介质：答案：指在枯燥过程中将热量传给木材、同时〔并〕将木材排出的水汽带走的媒介物质，叫做枯燥介质。评分：答复内容或意义完全正确得3分；答复内容或意义不完全、不答复、答复错误或局部错误得0分。5.导热系数：答案：指在木材单位厚度上的温度降低1℃评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。二、选择题：〔每题2分，共20分〕答案：1.D2.ABCD3.ABCD4.A5.A6.B7.B8.BC9.BD10.ACD评分：每题全部选对，得2分；不选、错选、选不全不得分。三、填空题：〔每空1分，共20分〕答案：1.传导〔导热〕对流辐射2.微毛细管〔路径〕大毛细管〔路径〕混合〔路径〕3.开裂弯曲翘曲皱缩变色枯燥不均炭化外表硬化霉变〔任写7个〕4.0〔零〕5.气干室干6.树种密度温度构造方向部位含水率〔任写四个〕评分：每空按标准填写，得1分，不填、填错得0分。判断题〔每题1分，共10分〕答案：1.√2.√3.×4.×5.√6.×7.√8.√9.×10.√评分：每题判断正确得1分，判断错误得0分。五、简答题〔每题5分，共15分〕1.真空枯燥的原理是什么？答案要点与评分：⑴降低了水的沸点，木材外表水分蒸发加剧；·······················································1分⑵在木材中形成内高外低较大的压力差，木材内部水分移动加快；···················1分⑶形成内高外低较大的含水率梯度，木材内部水分移动加快；························1.5分⑷木材内部水分之间粘度降低，木材内部水分移动加快。································1.5分2.强制循环比自然循环枯燥速度快的主要原因是什么？答案要点与评分：⑴强制循环介质的循环速度比自然循环快的多，木材外表水分易于蒸发或散；····························································································································1分⑵强制循环介质的循环速度比自然循环快的多，木材外表具有较高湿度的湿空气的层流层较薄，使木材内部水分易于向外表移动；············································2分⑶强制循环时木材水分的蒸发面比自然循环大的多。···········································2分3.气干才比室干才变形小的主要原因是什么？答案要点与评分：⑴气干时温度低；·······································································································1分⑵气干时介质的流动速度慢；···················································································1分⑶含水率梯度小；·······································································································1分⑷剩余应力小。···········································································································2分六、论述题〔每题10分，共20分〕1.如何预防枯燥过程中木材的开裂？答案要点与评分：⑴木材的开裂包括表裂、内裂和端裂；···································································2分⑵表裂和内裂是木材在枯燥过程中内外层应力不平衡产生的，而端裂是木材端部水分蒸发太快、木材干缩的各向异性引起的；·······························2分⑶采用合理的枯燥基准是预防开裂的较好方法；··················································2分⑷在枯燥初期与后期进行适时的调湿处理可有效防止表裂和内裂的产生，端部封闭可预防端裂；··················································································2分⑸终了处理可消除剩余应力，可防止枯燥结束后木材的开裂。···························2分2.枯燥过程中枯燥三角形及其面积的物理意义是什么？I〔kJ/㎏〕I〔kJ/㎏〕MMBBCøCø=1AANNd〔d〔g/㎏〕00答案要点与评分：⑴画出上面图形·······················································································································3分⑵△ABC为枯燥三角形··········································································································1分⑶△ABC反映了新鲜空气和废气混合、加热、枯燥、再混合……的屡次循环过程······1分⑷设：A的湿含量为dA，热含量为IAC的湿含量为dC，热含量为IC△ABC的面积为：S△=〔IC－IA〕×〔dC－dA〕······················································3分⑸△ABC的面积反映了一次循环后枯燥过程中对能量的利用。面积越大，能量利用越彻底、越充分。反之，能量利用那么不彻底、不充分，增加了循环次数。············2分木材枯燥试卷5标准答案及评分标准/年度第二学期期末考试试卷名词解释〔每题2分，共14分〕1.枯燥基准：答案：在木材枯燥过程中按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表，叫做木材枯燥基准，简称枯燥基准。评分：能够表达出“按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表”得2分；答复内容不完全，得1分；不答复、答复错误或局部错误得0分。2.湿容量：答案：在一定温度下每1m3评分：答复内容或意义完全正确得2分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。3.平衡含水率：答案：薄小木料在一定的空气状态下到达稳定的解吸或吸湿含水率叫做该木材在这种空气状态下的平衡含水率，简称平衡含水率。评分：完全答复正确得2分；短缺“薄小木料”或“在一定的空气状态下”其一得1.5分；二者均短缺得1分；不答复、答复错误或局部错误得0分。4.木材枯燥室：答案：装配又通风和加热设备，用来枯燥木材的建筑物或金属容器，叫做木材枯燥室〔枯燥窑或枯燥炉〕评分：答复内容或意义完全正确得2分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。5.露点：答案：湿空气在湿含量不变时其水蒸汽分压到达饱和压力时所对应的温度叫做湿空气的露点，简称露点。评分：答复内容或意义完全正确得2分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。6.干度：答案：1㎏湿蒸汽中干蒸汽的相对重量，叫做水蒸汽的干度，简称干度。评分：答复内容或意义完全正确得2分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。7.干缩系数：答案：在纤维饱和点以下时，木材的含水率每降低1%而引起木材的收缩量，叫做木材的干缩系数，简称干缩系数。评分：完全答复正确得2分；短缺“在纤维饱和点以下”得1分；不答复、答复错误或局部错误得0分。填空题：〔每空1分，共20分〕答案：1.过热水蒸汽湿空气炉气2.干湿球温度差3.毛细管压力差4.空气枯燥室过热蒸汽枯燥室炉气枯燥室5.风量风压转速效率6.气干室干7.含水率梯度8.大气高频微波除湿太阳能红外线加压真空化学接触炉气过热蒸汽〔任写5种〕评分：每空按标准填写，正确得1分，不填、填错得0分。选择题：〔每题2分，共30分〕答案：1.C2.AB3.D4.C5.B6.B7.AD8.AD9.ABCD10.C11.A12.D13.A14.BCD15.B评分：每题全部选对，得2分；不选、错选、选不全得0分。判断题〔每题0.5分，共10分〕答案：1.×2.×3.√4.√5.×6.×7.√8.√9.√10.×11.√12.×13.√14.×15.√16.×17.√18.√19.√20.√评分：每题判断正确得1分，判断错误得0分。简答〔每题4分，共16分〕1.木材枯燥时，强制循环为什么比自然循环快？答案要点与评分：⑴强制循环介质的循环速度比自然循环快的多，木材外表水分易于蒸发或散；····························································································································1分⑵强制循环介质的循环速度比自然循环快的多，木材外表具有较高湿度的湿空气的层流层较薄，使木材内部水分易于向外表移动；·········································1.5分⑶强制循环时木材水分的蒸发面比自然循环大的多。········································1.5分2.解吸与枯燥有何区别？答案要点与评分：枯燥排除的是自由水和结合水，而解吸那么只是排除结合水··································4分3.开裂的主要原因有哪些？答案要点与评分：⑴开裂分表裂、内裂和端裂；··················································································1分⑵表裂是枯燥开始时枯燥基准过硬、外表水分蒸发太快造成的；·······················1分⑶内裂是在枯燥后期出现应力后没有进行及时调湿处理造成的；·······················1分⑷端裂是由于端部水分蒸发太快及干缩的各向异性造成的。·······························1分4.木材枯燥的目的是什么？答案要点及评分：⑴防止木材开裂变形；·······························································································1分⑵防止木材腐朽变色；·······························································································1分⑶提高木材力学强度；·······························································································1分⑷减轻木材重量。·······································································································1分六、论述题〔共10分〕1.用I—d图说明一次循环的理想枯燥过程。〔3分〕øø=1I〔kJ/㎏〕d〔g/㎏〕BBCCKAKA00答案要点与评分：⑴K为新鲜空气的状态点，A为混合空气的状态点，B为混合空气加热后的状态点，C为废气状态点。···································································1分⑵新鲜空气与废气混合后，经加热进行枯燥，所消耗的热量全部用于蒸发木材中的水分，热含量不变。·······························2分2.在I—d图上说明实际的枯燥过程中，枯燥三角形面积的的变化对能量利用的影响。〔7分〕⑴上图中△ABC为枯燥三角形·························································································1分⑵三角形面积的变化有两种形式，即A点向C或K点靠近，C点向B点或相对湿度值为1的线靠近·······································································································1分⑶A点向C点靠近，三角形面积减小，说明混合气体中废气较多，枯燥过程中循环次数增多；A点向K点靠近，三角形面积增加，说明混合气体中新鲜空气较多，枯燥过程中加热需要的热量多；············································································2分⑷C点向B点靠近，三角形面积减小，说明废气的相对湿度值较小，介质带走的水分减少，能量利用不彻底；C点向相对湿度值为1的线靠近，三角形面积增加，说明废气的相对湿度值较大，介质带走的水分较多，能量利用较彻底。········2分⑸A点位置的变化对能量利用不如C点变化对能量利用彻底。····································1分木材枯燥试卷6标准答案及评分标准/年度第二学期期末考试试卷一、名词解释：〔每题3分，共15分〕1.纤维饱和点：答案：在大气条件下，当自由水已蒸发干净，而吸着水还保持着最高量时的木材含水率，叫做纤维饱和点或吸湿极限。评分：答复内容或意义完全正确得3分；答复内容仅短缺“在大气条件下”而其他内容或意义正确得2分；不答复、答复错误或局部错误得0分。2.湿容量：答案：在一定温度下每1m3评分：答复内容或意义完全正确得3分；答复内容或意义不完全得1分；不答复、答复错误或局部错误得0分。3.枯燥基准：答案：在木材枯燥过程中按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表，叫做木材枯燥基准，简称枯燥基准。评分：能够表达出“按木材枯燥的时间和状态〔含水率、应力〕的变化而编制的木材枯燥介质温度和相对湿度变化的程序表”得3分；答复内容不完全，得1分；不答复、答复错误或局部错误得0分。4.枯燥介质：答案：在木材枯燥过程中既能够把热量传递给木材又能够把木材内蒸发出的水分带走的媒介物质，叫做木材枯燥介质，简称枯燥介质。评分：答复内容或意义完全正确得3分；答复内容不完全、不答复、答复错误或局部错误得