化工原理笔记

1目录第一章流体流动与输送设备··················································（3）第一节流体静力学·····················································（3）第二节流体动力学····················································（5）第三节管内流体流动现象··············································（7）第四节流体流动阻力··················································（8）第五节管路计算······················································（11）第六节流速与流量的测量··············································（11）第七节流体输送设备··················································（13）第二章非均相物系分离·····················································（21）第一节概述···························································（21）第二节颗粒沉降·······················································（22）第三节过滤····························································（25）第四节过程强化与展望·················································（27）第三章传热······························································（28）第一节概述·····························································（28）第二节热传导···························································（28）第三节对流传热·························································（30）第四节传热计算·························································（30）第五节对流传热系数关联式···············································（31）第六节辐射传热························································（34）第七节换热器··························································（35）第四章蒸发·······························································（37）第一节概述·····························································（37）第二节单效蒸发与真空蒸发···············································（37）第三节多效蒸发·························································（40）第四节蒸发设备························································（41）第五章气体吸收··························································（42）第一节概述····························································（42）第二节气液相平衡关系···················································（45）2第三节单相传质·························································（46）第四节相际对流传质及总传质速率方程·····································（49）第五节吸收塔的计算······················································（51）第六节填料塔····························································（58）第六章蒸馏·······························································（60）第一节概述·····························································（60）第二节双组分物系的气液相平衡···········································（60）第三节简单蒸馏和平衡蒸馏···············································（62）第四节精馏·····························································（63）第五节双组分连续精馏的计算·············································（63）第六节间歇精馏·························································（67）第七节恒沸精馏与萃取精馏···············································（67）第八节板式塔···························································（67）第九节过程的强化与展望···················································（69）第七章干燥······························································（71）第一节概述·····························································（71）第二节湿空气的性质及湿度图·············································（71）第三节干燥过程的物料衡算与热量衡算·····································（73）第四节干燥速率和干燥时间···············································（75）第五节干燥器···························································（76）第六节过程强化与展望···················································（78）3第一章流体流动与输送设备第一节流体静力学流体静力学主要研究流体处于静止时各种物理量的变化规律。1-1-1密度单位体积流体的质量，称为流体的密度。),(Tpf液体密度一般液体可视为不可压缩性流体，其密度基本上不随压力变化，但随温度变化，变化关系可从手册中查得。液体混合物的密度由下式计算：nnmaaa22111式中，ia为液体混合物中i组分的质量分数；气体密度气体为可压缩性流体，当压力不太高、温度不太低时，可按理想气体状态方程计算RTpM一般在手册中查得的气体密度都是在一定压力与温度下的数值，若条件不同，则此值需进行换算。气体混合物的密度由下式计算：nn2111m式中，i为气体混合物中i组分的体积分数。或RTpMmm其中nnyMyMyMM2211m式中，iy为气体混合物中各组分的摩尔分率。对于理想气体，其摩尔分率y与体积分数φ相同。1-1-2压力流体垂直作用于单位面积上的力，称为流体的静压强，又称为压力。在静止流体中，作用于任意点不同方向上的压力在数值上均相同。4压力的单位（1）按压力的定义，其单位为N/m2，或Pa；（2）以流体柱高度表示，如用米水柱或毫米汞柱等。标准大气压的换算关系：1atm=1.013×105Pa=760mmHg=10.33mH2O压力的表示方法表压=绝对压力－大气压力真空度=大气压力－绝对压力1-1-3流体静力学基本方程静力学基本方程：压力形式)(2112zzgpp能量形式gzpgzp2211适用条件：在重力场中静止、连续的同种不可压缩流体。（1）在重力场中，静止流体内部任一点的静压力与该点所在的垂直位置及流体的密度有关，而与该点所在的水平位置及容器的形状无关。（2）在静止的、连续的同种液体内，处于同一水平面上各点的压力处处相等。液面上方压力变化时，液体内部各点的压力也将发生相应的变化。（3）物理意义：静力学基本方程反映了静止流体内部能量守恒与转换的关系，在同一静止流体中，处在不同位置的位能和静压能各不相同二者可以相互转换，但两项能量总和恒为常量。应用：1.压力及压差的测量（1）U形压差计gRpp)(021若被测流体是气体，可简化为021RgppU形压差计也可测量流体的压力，测量时将U形管一端与被测点连接，另一端与大气相通，此时测得的是流体的表压或真空度。（2）倒U形压差计5RgRgpp)(021（3）双液体U管压差计)(21CARgpp2.液位测量3.液封高度的计算第二节流体动力学1-2-1流体的流量与流速一、流量体积流量VS单位时间内流经管道任意截面的流体体积，m3/s或m3/h。质量流量mS单位时间内流经管道任意截面的流体质量，kg/s或kg/h。二、流速平均流速u单位时间内流体在流动方向上所流经的距离，m/s。质量流速G单位时间内流经管道单位截面积的流体质量，kg/（m2·s）。相互关系：质量流量mSkg/smS=VSρ体积流量VSm3/s质量流速Gkg/（m2·s）(平均)流速um/sG=uρ1-2-2定态流动与非定态流动流体流动系统中，若各截面上的温度、压力、流速等物理量仅随位置变化，而不随时间变化，这种流动称之为定态流动；若流体在各截面上的有关物理量既随位置变化，也随时间变化，则称为非定态流动。1-2-3定态流动系统的质量守恒——连续性方程mS=GA=πd2G/4VS=uA=πd2u/4ρ=常数（不可压缩流体）常数常数221121AuAuVVSS常数常数222111S21SAuAumm61-2-4定态流动系统的机械能守恒——柏努利方程一、实际流体的柏努利方程以单位质量流体为基准：f2222e12112121WpugzWpugzJ/kg以单位重量流体为基准：f2222e12112121hgpugzHgpugzJ/N=m适用条件：（1）两截面间流体连续稳定流动；（2）适于不可压缩