工程热力学(第三版)习题答案全解可打印第三章

143-1M=28.1×10-3kg/mol(1)2NRg(2)2Nv0ρ0(3)132Nm0(4)p=0.1MPat=500N2vρ(5)Vm(1)R=8.3145J/(mol·K)M2N=28.01×10-3kg/molRg2N=RM=38.3145J/(molK)28.0110kg/mol−⋅×=0.297kJ/(kg·K)(2)1molV2,Nm=Mv2N=22.4×10-3m3/molv2N=2,mNVM=33322.410m/mol28.0110kg/mol−−××=0.8m3/kg()22N3N110.8m/kgvρ===1.25kg/m3()(3)13ρ1.25kg(4)pv=RgTv=g36297J/(kgK)(500273)K2.296m/kg0.110PaRTp⋅×+==×33110.4356kg/m2.296m/kgvρ===(5)Vm=Mv=28.01×10-3kg/mol×2.296m3/kg=64.29×10-3m3/mol3-238CH4.4MPa,1201000kg38CHM=44.09×10-3kg/mol3838g,CH3CH8.3145J/(molK)189J/(kgK)44.0910kg/molRRM−⋅===⋅×1kgpv=RgT15g36189J/(kgK)(120273)K0.01688m/kg4.410PaRTvp⋅×+===×V=mv=1000kg×0.01688m3/kg=16.88m3pV=mRgT361000kg189J/(kgK)(120273)K16.88m4.410PagmRTVp×⋅×+===×3-317Cbt=°750mmHgbp=0.2m3V=1m3117Ct=°10.05MPaep=20.7MPap=,250Ct=°(3-9)gpVmRT=511g1gg7500.5101517.21750.062(17273)pvmRTRR+××===+522g2gg71012167.18(50273)pvmRTRR××===+30.2m/mininVq=5gg750100.268.96750.062(17273)ininininVbVmininggpqpqqRTRTRR××====+τgg2121g2167.18/R517.21/R23.93min68.96/Rininmmmmqmmqττ−−=−===3-450003m/h250C°150mmHg756mmHgbp=20.1MPap=162480KT=3m/sfc=1inVq23-10100760mmHg0.101325MPa273KpT===33,022.410m/molmV−=×0,03335000m/h22.410m/mol223.21kmol/h0.062kmol/smVnVqqq−==×==53223.21kmol/h8.3145J/(molK)(250273)K15076510Pa750.0627962.7m/hninqRTqp×⋅×+==+×=000VVpqpqTT=053035076010Pa5000m/h523K750.0627962.7m/h15076510Pa273K750.062inVVpqTqpT×××===+××232620.062mol/s8.3145J/(molK)480K2.4745m/s0.110PaoutnVqRTqp×⋅×===×D234D42.4745m/D1.025m43m/soutoutVVffqsqccπππ×====×3-5250C°100C°12AA12mmqq=221121ffAcAcvv=2211122211373K0.7132523KVmVmqpqTTqpqTT====17222111222111/1:1.4/VmVffVmVqqqAvccAvqqq=====3-62100cmA=h=10cm195kg3-110771mmHgp=027Ct=°100kg211143771195kg9.80665m/s10MPa0.294MPa750.06210010mbmgppA−−×=+=×+=×2333311(27273)K300K100cm10cm10cm10mTV−=+==×==100kg212242771(195100)kg9.80665m/s10MPa0.196MPa750.06210010mbmgppA−−−×=+=×+=×227273300KT=+=112212pVpVTT=333312120.294MPa10m1.510m0.196MPapVVp−−==×=×332142(1.51)10m0.05m5cm10010mVVVHAA−−−∆−×∆=====×1264220.19610Pa0.05m10010m98JWpAH−=∆=××××=TT21=UU21=∆U=098JQUWW=∆+==3-711480K0.2MPaTp==21100KT=20.5MPap=1kg1212uuuhhh∆∆(1)(2)18(3)1212480K1100K0.2MPaTTpp====1212uuuhhh∆∆(4)uhuh,uh∆∆g0.287kJ/(kgK)R=⋅11273480273207CtT=−=−=°222731100273827CtT=−=−=°207C827C0C0C1.0125kJ/(kgK)1.0737kJ/(kgK)||ppc°°°°=⋅=⋅c207C207Cg0C0C827C827Cg0C0C1.0125kJ/(kgK)0.287kJ/(kgK)0.7255kJ/(kgK)1.0737kJ/(kgK)0.287kJ/(kgK)0.7867kJ/(kgK)||||VpVpccRcCR°°°°°°°°=−=⋅−⋅=⋅=−=⋅−⋅=⋅207C110C827C220C0.7255kJ/(kgK)207C150.2kJ/kg0.7867kJ/(kgK)827C650.6kJ/kg||VVuctuct°°°°==⋅×===⋅×=oo21650.6kJ/kg150.2kJ/kg500.4kJ/kguuu∆=−=−=207C110C827C220C1.0125kJ/(kgK)207C209.6kJ/kg1.0737kJ/(kgK)827C887.9kJ/kg||pphcthct°°°°==⋅×===⋅×=oo21887.9kJ/kg209.6kJ/kg678.3kJ/kghhh∆=−=−=212480K1100KTT==12484.49kJ/kg1162.95kJ/kghh==guhRT=−11g122g22121484.49kJ/kg0.287kJ/(kgK)480K346.73kJ/kg1162.95kJ/kg0.287kJ/(kgK)1100K847.25kJ/kg847.25kJ/kg346.73kJ/kg50052kJ/kg1162.95kJ/kg484.49kJ/kg678.46kJ/kguhRTuhRTuuuhhh=−=−⋅×==−=−⋅×=∆=−=−=∆=−=−=3uh12480K1100KTT==1212uuhhuh∆∆4uh0Kuh0C°19uhuh∆∆3-830.5mV=27C0.6MPa°327C°vQ(1)(2)(3)(4)(5)1127273300KT=+=0.658kJ/(kgK)Vc=⋅1327273600KT=+=0.742kJ/(kgK)Vc=⋅600K300K0.658kJ/(kgK)0.742kJ/(kgK)0.7005kJ/(kgK)2|Vc⋅+⋅==⋅11g1pVmRT=m223Og3O8.3145J/(molK)32.010kg/mol0.260kJ/(kgK)32.010kg/molRMRM−−⋅=×===⋅×631g0.610Pa0.5m3.846kg260J/(kgK)(27273)KpVmRT××===⋅×+600K21300K()3.846kg0.7005kJ/(kgK)(600300)K808.27kJ|vVQmcTT=−=×⋅×−=2631g0.610Pa0.5m120.3mol8.3145J/(molK)(27273)KpVnRT××===⋅×+127Ct=°27C,0C29.345J/(molK)|pmC°°=⋅2327Ct=°327C,0C30.529J/(molK)|pmC°°=⋅27C27C,,0C0C29.345J/(molK)8.3145J/(molK)21.031J/(molK)||VmpmCCR°°°°=−=⋅−⋅=⋅327C327C,,0C0C30.529J/(molK)8.3145J/(molK)22.215J/(molK)||VmpmCCR°°°°=−=⋅−⋅=⋅21,2,100()120.3mol[22.215J/(molK)327C21.031J/(molK)27C]805.59kJ||ttvVmVmQnCtCt=−=×⋅×−⋅×=oo3CRTTTpm,....=−×+×−×−−−362618781070551067641036212420,,VmpmCCR=−,,,,1ddpmVmVmvVmCCCQnCTnRTRRR=−==∫∫600K362300K94126322633120.3mol8.3145J/(molK)(3.6261)1.878107.05510d6.764102.156101.87810120.3mol8.3145J/(molK)[2.626(600300)(600300)27.055106.764(600300)3vQTTTTT−−−−−−=×⋅−−×+×−×+××=×⋅××−−×−××+×−−∫944125510(600300)42.15610(600300)]805.955kJ−−×−×+×−=(4)210.65940.000106kJ/(kgK)|tVtct=+⋅210.65940.000106(27327)0.6971kJ/(kgK)|tVtc=++=⋅2121()3.846kg0.6971kJ/(kgK)(32727)K804.31kJ|tvVtQmctt=−=×⋅×−=5,1300KT=,18737.3J/molmH=2600KT=,217926.1J/molmH=,1,118737.3J/mol8.3145J/(molK)300K6242.95J/molmmUHRT=−=−⋅×=,2,2217926.1J/mol8.3145J/(molK)600K12937.4J/molmmUHRT=−=−⋅×=,2,1()120.3mol(12937.4J/mol6242.95J/mol)805.34kJvmmQnUU=−=×−=3-9311520kPa0.1419mpV==2170kPap=320.2744mV=67.95kJH∆=−5.20kJ/(kgK)pc=⋅12Rg1H=U+pV)()(1122VpVpUpVUH−+∆=∆+∆=∆3367.95kJ(170kPa0.2744m520kPa0.1419m)40.81kJ=−−×−×=−212VUmcT∆=∆pHmcT∆=∆5.20kJ/(kgK)3.123kJ/(kgK)/67.95kJ/(40.81kJ)pVccHU⋅===⋅∆∆−−5.20kJ/(kgK)3.123kJ/(kgK)2.077kJ/(kgK)gpVRcc=−=⋅−⋅=⋅3-102kg367.6kJvQ=468.3kJ3-121.124kJ/(kgK)pc=⋅0.934kJ/(kgK)Vc=⋅1280Ct=°1t22UHS∆∆∆1QUW=+∆367.6kJ(468.3kJ)835.9kJvUQW∆=−=−−=21()VUmctt∆=−21835.9kJ280C+727.48C2kg0.934kJ/(kgK)VUttmc∆=+==×⋅oo2gHUmRT∆=∆+∆()835.9kJ2kg[1.124kJ/(kgK)0.934kJ/(kgK)](727.48C280C)1005.94kJpVUm