Grfico1

Una mquina de Carnot se acopla a un refrigerador de Carnot en forma tal que todo el trabajo realizado por la primera es empleado por el refrigerador para extraer calor de un depsito trmico a 270K a razn de 4 kJs_1. La fuente de energa para la mquina de Carnot es una fuente a 500K. Si ambos sistemas rechazan calor a los alrededores a 300K, cunto calor absorbe la mquina desde la fuente a 500K?Si = Carnot/1.5 es el coeficiente de rendimiento real del refrigerador y la eficiencia trmica de la mquina es = Carnot/1.5 , cunto calor absorbe la mquina de la fuente a 500K?mquina de carnotrefrigerador de carnot

NESSEjemplo 9.1fluidoTaF(F)TaC(F)DTC(F)DTF(F)QF(Btu/h)Problema 9.3fren-1210701010120000refrigeranteTF(F)TC(F)QF(Btu/s)hamoniaco309030000.8TF(F)TC(F)080a)Para el refrigerador de Carnota)Para el refrigerador de CarnotwW(Btu/h)QC(Btu/s)T1(F)H1L(Btu/lbm)S1L(Btu/lbm)T4(F)H4V(Btu/lbm)S4V(Btu/lbm)S3(Btu/lbm)8.1666666667367.34693877553367.346938775590143.50.2958906321.18461.1846S2(Btu/lbm)T2(F)HL(Btu/lbm)HV(Btu/lbm)SL(Btu/lbm)SV(Btu/lbm)x2H2(Btu/lbm)x3H3(Btu/lbm)0.29583075.7620.50.16631.2790.1163835715139.10576974930.9151613193574.2798867619QF(Btu/lbm)m(lbm/s)Po(Btu/s)435.17411701276.8937923528397.9104752436b)Ciclo de refrigeracin con expansorb)Ciclo con vlvula de estrangulamientoT2(F)H2(Btu/lbm)S2(Btu/lbmR)S3(Btu/lbmR)T4(F)H4(Btu/lbm)S4(Btu/lbmR)T2(F)H3(Btu/lbm)S3(Btu/lbmR)S'4(Btu/lbmR)P1(psi)077.2710.168880.168888026.3650.0547530620.51.2791.279180.6P4(psi)P3(psi)H3(Btu/lbm)S1(Btu/lbmR)S1L(Btu/lbmR)S1V(Btu/lbmR)x1P4(psi)P(psi)S(Btu/lbmR)S(Btu/lbmR)H(Btu/lbm)H(Btu/lbm)S'3(Btu/lbmR)S(Btu/lbmR)H(Btu/lbm)H'3(Btu/lbm)98.8798.8788.30.054750.019320.168880.2368948917180.61801.2691.289681693.61.2791.268865681.1215687.508070252201.261.28689.1701.91.288865693.7245H1L(Btu/lbm)H1V(Btu/lbm)H1(Btu/lbm)-400.0090.009-8.1-8.3-0.02-12.6038.520777.27124.80729487161.2688651.288865681.1215693.7245687.50807025Respuestawm(lbm/h)5.53923258012287.2955637877W'(compresor)hW(compresor)H3(Btu/lbm)H4(Btu/lbm)H1(Btu/lbm)67.008070250.883.7600878125704.2600878125143.5143.5c)Ciclo con vlvula de estrangulamientoRespuestawm(lbm/h)QC(Btu/lbm)W(Btu/h)T2(F)H2(Btu/lbm)S2(Btu/lbmR)S'3(Btu/lbmR)P3(psi)H'3(Btu/lbm)5.69483643656.2893081761560.7600878125526.7930051101077.2710.168880.1688898.8788.3W'(compresor)hW(compresor)H3(Btu/lbm)H4(Btu/lbm)H1(Btu/lbm)refrigeranteTF(F)TC(F)QF(Btu/s)11.0290.813.7862591.0572526.36526.365fren -121080400Respuestawm(lbm/h)a)Para el refrigerador de Carnot3.69251972072357.2859780772wW(Btu/s)QC(Btu/s)H4L(Btu/lbm)H3V(Btu/lbm)QC(Btu/lbm)m(lbm/s)Ejemplo 9.26.714285714359.5744680851459.574468085126.36585.28258.9177.8003711677QC(kJ/s)QF(kJ/s)Ta(invierno)(C)Ta(verano)(C)T(suelo)(C)TC(invierno)(C)TF(verano)(C)30602025151025RespuestawW(Btu/s)QC(Btu/s)m(lbm/s)6.714285714359.5744680851459.57446808517.8003711677TR(invierno)(C)TR(verano)(C)305b)Ciclo con vlvula de estrangulamientoT2(F)H2(Btu/lbm)S2(Btu/lbmR)S'3(Btu/lbmR)P3(psi)inviernoTF(invierno)(C)TC(invierno)(C)QF(kJ/s)W(kJ/s)1078.3350.167980.1679898.87283.15303.1528.02078179121.9792182088P3(psi)P(psi)S(Btu/lbmR)S(Btu/lbmR)H(Btu/lbm)H(Btu/lbm)S'3(Btu/lbmR)S(Btu/lbmR)H(Btu/lbm)H'3(Btu/lbm)veranoTF(verano)(C)TC(verano)(C)QF(kJ/s)W(kJ/s)98.871000.169960.1759789.17588.6940.167980.169995789.22541589.3864754133278.15298.1555.97518027844.3142189466900.172340.1782492.53692.1160.1760040588.7453310-0.00238-0.00227-3.361-3.422-0.006008350.480085RespuestaW(kW)0.16999570.1760040589.22541588.7453389.38647541334.3142189466Ejemplo 9.3W'(compresor)hW(compresor)H3(Btu/lbm)H4(Btu/lbm)H1(Btu/lbm)fluidoP3(bar)T3(K)H3(kJ/kg)P8(bar)T8(K)H8(kJ/kg)11.05147541330.7714.352565471992.687565471926.36526.365metano60300114012951188.9Respuestawm(lbm/s)QC(Btu/lbm)W(Btu/s)T1sat(K)H6L(kJ/kg)H7V(kJ/kg)wH4(kJ/kg)3.62095543847.696748123966.3225654719110.468081369111.45285.4796.90.0541228556769.2161593802

BalzhiserProblema 7-10Problema 7-14fluidoQF(kcal/dia)TF(C)Texterior(C)TC(C)fren-12766-17.826.726.7a)TF(R)TC(R)wW(Btu/h)W(cv)459.426540.065.697670957722.21479286133.7344693886b)Pc(ata)PF(ata)Pc(psia)PF(psia)QF(Btu/h)11.71.3171.942958062619.1047731181126.5725801165PF(psia)PF(psia)TF(F)Pc(psia)Pc(psia)TC(F)fluidorelacin.compresinTF(F)hcompresorQF(Btu/min)1.30.97034-110171.9429580626151.11110fren-129-100.71101.428-100172.35120-0.45766-10-21.24-10a)T3(R)H3(Btu/lbm)P3(psia)S3(Btu/lbmR)P4(psia)H4'(Btu/lbm)H4(Btu/lbm)-102.7968360792119.8083606698-1076.19619.1890.16989172.7019197.3445714286TF(R)TC(R)wW(Btu/h)W(cv)P1(psia)P(psia)H(Btu/lbm)H1(Btu/lbm)P2(psia)H2(Btu/lbm)H2L(Btu/lbm)H2V(Btu/lbm)x2357.2031639208579.80836066981.604648809478.878680106313.2600838599172.701172.3536.01336.051165239719.18936.05116523976.371670.1960.465019103195.7138.553c)-23.36-2.5436.0511652397Respuestam(lbm/min)2.7400785346b)Wcom(Btu/lbm)Wcom(Btu/s)Wcom(hp)Respuesta21.14857142860.96581244351.3664621324fluidoP2(ata)P2(psia)P3(ata)P3(psia)P4(ata)P4(psia)P1(ata)P1(psia)T3(C)T3(F)c)hexpansorP1(psia)P(psia)H(Btu/lbm)S(Btu/lbmR)H1(Btu/lbm)S1(Btu/lbmR)SL(Btu/lbmR)SV(Btu/lbmR)x2fren - 121.291911.917511.71721.3620821800.6172.701172.3536.0130.0716836.05116523970.07174235660.014620.169890.3678904914195.7138.5530.07583P3(psia)T3(F)H3(Btu/lbm)P2(psia)P2(psia)H2(Btu/lbm)H2(Btu/lbm)-23.36-2.54-0.0041517518099.8231915.26775.1176.131984515836.05116523970.071742356619.18976.196-3.922-1.086H2L(Btu/lbm)H2V(Btu/lbm)H2(Btu/lbm)'DH(Btu/lbm)'H2(Btu/lbm)Wexpan(Btu/lbm)Wneto(Btu/lbm)Wcom(Btu/s)Wcom(hp)76.13198451586.371670.19629.85198987636.199175363432.33166002173.71950521817.42906621050.795950171.1261355908P4(psia)P4(psia)H4(Btu/lbm)H4(Btu/lbm)H1(Btu/lbm)QF(Btu/h)m(lbm/h)RespuestaWneto(Btu/lbm)Wcom(Btu/s)Wcom(hp)172151.1133.53135.965435118235.9654351182126.57258011653.151193767317.42906621050.795950171.1261355908172.3536.013-21.24-2.482Problema 7-1535.9654351182P2(psia)P2(psia)H2(Btu/lbm)S2(Btu/lbmR)H2(Btu/lbm)S2(Btu/lbmR)S3(Btu/lbmR)1915.26775.110.1710276.13198451580.16995660910.169956609119.18976.1960.16989-3.922-1.0860.0011376.13198451580.1699566091P3(psia)S3(Btu/lbmR)S3(Btu/lbmR)H3(Btu/lbm)H3(Btu/lbm)Wcom(Btu/lbm)Wcom(Btu/h)1750.16995660910.1685992.37393.205108198517.073123682753.80072093780.1747896.142-0.00619-3.76993.2051081985CICLO PROPUESTORespuestam(lbm/h)Wcom(Btu/h)Wcom(hp)fluidoP2(ata)P2(psia)H2(Btu/lbm)S2(Btu/lbmR)S3(Btu/lbmR)P3(ata)P3(psia)T3(C)T3(F)H3(Btu/lbm)3.151193767353.80072093780.0211441582CO210.2149.898989080200.330.33751102.19844911912169.8154Problema 7-12Propiedades del fluidoP4(ata)P4(psia)T4(F)H4(Btu/lbm)H1(Btu/lbm)QF(Btu/lbm)751102.198449119169.8118118-118T(C)Psat(ata)Sliq. SatDSvapSvap.satkcal/(kg.K)T(C)T(C)Sliq. SatDSvapSvap.satRespuesta aQF(Btu/lbm)105.690.04130.1260.16793837.80.06320.10260.1658-11836.78.960.06230.10360.165938.70.0640.10180.165837.89.210.06320.10260.1658-0.9-0.00080.00080Respuesta bW(Btu/lbm)38.99.470.0640.10180.16580.06337777780.10242222220.1658154T(C)T(C)Sliq. SatDSvapSvap.satCICLO CONVENCIONAL10100.04130.12660.167936.70.06230.10360.1659P2(ata)P2(psia)H2(Btu/lbm)S2(Btu/lbmR)S3(Btu/lbmR)P3(ata)P3(psia)T3(C)T3(F)H3(Btu/lbm)-26.7-0.0210.0230.00210.2149.898989080200.330.33751102.19844911913595600.04130.12660.1679P4(ata)P4(psia)T4(F)H4(Btu/lbm)H1(Btu/lbm)QF(Btu/lbm)751102.198449119195118118-118QF(Btu/lbm)-118W(Btu/lbm)Problema N2Prueba N360a)S4(kcal/kg.K)S3(kcal/kg.K)S3L(kcal/kg.K)S3V(kcal/kg.K)x30.16580.16580.04130.16790.9834123223Respuestax0.9834123223b)S2L(kcal/kgK)S2V(kcal/kgK)x2S2(kcal/kgK)DS23(kcal/kgK)T2(C)QF(kcal/kg)0.04130.16790.1850.0647210.1010791028.62051885T4(C)S1L(kcal/kg.K)S4V(kcal/kg.K)DS14(kcal/kgK)QC(kcal/kg)QC/QF380.06337777780.16580.102422222231.86867444441.1134904511RespuestaQC/QF1.1134904511Problema 7-19c)QC(kcal/h)m(kg/h)Wcompre(kcal/kg)Wcompre(kcal/h)145045.49922534523.2481555944147.7885633478fluidoT1(C)P1(ata)P2(ata)CO215.681.51.02RespuestaWcompre(kcal/h)147.7885633478d)QC(kcal)Trecinto(C)DSrecinto(kcal/K)DSsuelo(kcal/kgK)Tagua sub suelo(C)QF(kcal/kg)1450224.91275622564.912756225615.61418.5583601558T1(F)P1(psia)H1(btu/lbm)H2(btu/lbm)RespuestaWcompre(kcalkg)Wcompre(kcal/h)60.081197.7223147095-3870-387031.44163984411430.5702564909P2(psia)HL(btu/lbm)HV(btu/lbm)x14.989898908-4037-37900.6761133603Ejemplo 7.13

a) En una cierta unidad de congelacin profunda, el calor es tranferido a la cmara fra desde los alrededores es de 766 kcal/da. La cmara es mantenida a -17.8C, en tanto que el ambiente exterior est a 26.7C. Cul es la potencia nominal (en CV) del motor ms pequeo que puede ser usado en un ciclo de refrigeracin ideal para mantener la cmara a -17.8C?b) Supngase que el ciclo usa fren-12 como fluido de trabajo y que tiene una presin de 11.7 ata en el condensador y una presin de 1.3 ata en el evaporadorcul es la potencia nominal (cv) del motor ms pequeo que puede usarse en el ciclo?Una termobomba est siendo usada para mantener un recinto a 21.1C, extrayendo calor desde el agua del sub suelo y entregando calor al reinto.a) Cul es la calidad del fluifo que sale del evaporador?b) Cul es la mxima cantidad de calor que puede ser entregada al recinto por cada kcal extrada del agua del sub suelo?c) Si el recinto ha de recibir 1450 kcal/h, cul esla mnima potencia nominal del motor que impulsa el compresor?d) En un ciclo cualquiera, ul es la mnima energa que deber ser suministrada para bombear 1450 kcal al recinto, si se usa como fuente de calor el agua del sub suelo?Las propiedades del fluido son:Un refrigerasor convencional usa fren-12, como fluido de trabajo. En el ciclo de operacin, un compresor aislado, y cuta relacin de compresin es de 9 a 1( esto es, la presin de salida es 9 veces la de entrada), es alimentador con vapor saturado de -10C. El compresor tiene un rendimiento de 70%, basado en una compresin adibtica reversible sobre elmismo intervalo de presin. El gas comprimido que sale del compresor es enfriado y condensado isobricamente hasta el estado de lquido saturado. El lquido saturado se hace pasar por una vlvula de estrangulamiento bien aislada cuya presin de salida corresponde a una temperatura de saturacin de -10F. La mezcla que sale de la vlvula de estrangulamiento va al evaporador, donde absorbe calor, de las bandejas para el hielo y del interior del refrigerador, el calor justamente suficiente para convertirse en vapor saturado, que entra al compresor y repite el ciclo. En condiciones de verano (carga mxima) se anticipa que habr que absorber 110 Btu/min en el evaporador.a) Cul es la msica de circulacin de fren-12 en lbm/min?b) Cul debera ser la potencia nominal (de salida) del motor del compresor?c) Si la vlvula de estrangulamiento fuera reemplazada por un turboexpansor con rendimiento de 60% (basado en la expansin adibtica reversible, en el mismo intervalo de presin) y se se usar el trabajo de este expansor para ayudar a impulsar el copresor, qu potencia nominal debera tener el motor necesario para suplir el trabajo restante del compresor?d) Si una termobomba perfecta estuviese operando entre las mismas temperaturas de evaporacin y condensacin, qu motor (potencia nominal) requerir?El ciclo de refrigeracin mostrado en la figura ha sido propuesto para reemplazar el ciclo ms convencional mostrado a la derecha. Si el fluido circundante es CO2 y si las temperaturas de los fluidos en la entrada y salida de la cmara fra han de ser los mismos en ambos sistemas, determinar lo siguiente:a) El calor extradido desde la cmara fra por cada kg de CO2 a travs del ciclo propuesto (con el ciclo convencional inoperativo)b) El trabajo total (kcal por cada kg de CO2 que circula) entregado al ciclo propuestoc) El trabajo total (kcal por cada kg de CO2 que circula) entregado al ciclo convencionald) La forma que adopta cada ciclo en un diagrama T-Se) La razn de que un ciclo sea ms eficiente que otrof) El tarabjo de refrigeracin mnimo absoluto que corresponde a las condiciones de entrada y salida dadas fra y para el agua de enfriamiento (kcal por cada kg de CO2 que circula)Se dispone de dixido de carbono a 15.6C y 81.5 ata. Se desea fabricar dixido de crabono slido por evaporacin instantnea a 1.02 ata. Si se hace pasar al CO2 a travs de una vlvula y se permite que el gas escape libremente a los alrededores y si las partculas slidas son capturadas en una bolsa.a) Cul ser la temperatura del slido?b) Que fracccin del CO2 ser recuperable como slido?condensadorevaporadorvlvula de expansinP = 1.36 ataP = 1.29 atavapor saturadoP = 11.9 ataT = 82CP = 11.7 atalq. saturado1234condensadorevaporadoragua del sub suelo, 15.6Cvlvula de estrangulamientoadiabticarecinto, 21.1Ccompresoradiabticoreversible10C10Ccalidad, 18.5%lquido sat.38C38Cvapor sat.1234condensadorevaporadorvlvula de estrangulamientoadiabticacompresoradiabtico-10Flquido sat.1234vapor sat.-10F12Compresor adiabticoreversibleCompresor adiabticoreversibleIintercambiadorde calorCmarafraCompresorisotrmicoreversibleAgua de enfriamientoT = 10CAgua de enfriamientoT = 10CT = 21CT = 21CT = 35C10.2 ata75 ata10.2 ata75 ata75 ata28.2 ata12341'2'3'4'CICLO CONVENCIONALCICLO PROPUESTO10.2 ata

SS-1-2 000Problema N2Propiedades del fluidoT(C)Psat(ata)Sliq. SatDSvapSvap.satkcal/(kg.K)105.690.04130.1260.167936.78.960.06230.10360.165937.89.210.06320.10260.165838.99.470.0640.10180.1658T(C)T(C)Sliq. SatDSvapSvap.satSliq. SatDSvapSvap.sat3837.80.06320.10260.16580.063350.102450.165838.90.0640.10180.1658-1.1-0.00080.000800.063350.102450.1658T(C)T(C)Sliq. SatDSvapSvap.satSliq. SatDSvapSvap.sat10100.04130.12660.16790.04130.12660.167936.70.06230.10360.1659-26.7-0.0210.0230.0020.04130.12660.1679Problema N2a)S4(kcal/kg.K)S3(kcal/kg.K)S3L(kcal/kg.K)S3V(kcal/kg.K)x30.16580.16580.04130.16790.9834123223Respuestax0.9834123223b)S2L(kcal/kgK)S2V(kcal/kgK)x2S2(kcal/kgK)DS23(kcal/kgK)T2(C)QF(kcal/kg)0.04130.16790.1850.0647210.1010791028.62051885T4(C)S1L(kcal/kg.K)S4V(kcal/kg.K)DS14(kcal/kgK)QC(kcal/kg)QC/QF380.063350.16580.1024531.87731751.1137924392RespuestaQC/QF1.1137924392c)QC(kcal/h)m(kg/h)Wcompre(kcal/kg)Wcompre(kcal/h)145045.4868889143.25679865148.1416384079RespuestaWcompre(kcal/h)148.1416384079d)QC(kcal)Trecinto(C)DSrecinto(kcal/kg.K)DSsuelo(kcal/kgK)Tagua sub suelo(C)QF(kcal/kg)1450224.91275622564.912756225615.61418.5583601558RespuestaWcompre(kcalkg)Wcompre(kcal/h)31.44163984411430.1823788659Problema N5fluidoT2(C)T1(C)QF(toneladas)fren-12-184118T2(F)T3(F)T1(F)QF(kcal/h)QF(Btu/h)QF(kW)QF(Btu/min)-0.4-0.4105.854.432216000820400282.7511263600T1(F)T1(F)SL(Btu/lbm.R)HL(Btu/lbm)P(psia)H1(Btu/lbm)105.81000.0632331.1131.8632.509981100.0674533.531151.11-10-0.00422-2.431-19.250.065677632.50998143.025S1(kcal/kg.K)S2(Btu/lbmkg.R)0.06567760.0656776T2(F)T(F)SL(Btu/lbm.R)SV(Btu/lbm.R)V(ft3/lbm)HL(Btu/lbm)HV(Btu/lbm)x2H2(Btu/lbm)H3(Btu/lbm)-0.4-100.014620.169891.97276.371676.1960.310742353929.811716786577.22800.019320.168881.60898.520777.271-10-0.00470.001010.3638-2.1491-1.0750.0191320.16892041.6234528.43473677.228P4(psia)S4(kcal/kg.K)H4(Btu/lbm)143.0250.168920473.8a)QF(Btul/lbm)m(lbm/min)47.416283213575.9232853362b)m(g/s)573.9710648257c)v(cm3/s)5817.1202428393

condensadorevaporadoragua del sub suelo, 15.6Cvlvula de estrangulamientoadiabticarecinto, 21.1Ccompresoradiabticoreversible10C10Ccalidad, 18.5%lquido sat.38C38Cvapor sat.1234

WILCaptuloProblema 9.1fluidofluidofluidofluidovapor de aguaP2(psi)T2(F)P3(psi)P3(psi)P3(psi)P3(psi)vapor de aguaP2(psi)T2(F)P3(psi)P3(psi)P3(psi)P3(psi)vapor de aguaP2(psi)T2(F)P3(psi)P3(psi)P3(psi)P3(psi)vapor de aguaP2(psi)T2(F)P3(psi)P3(psi)P3(psi)P3(psi)40060014521400600145214006001452140060014521P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)4006001.59011307.41.59014006001.59011307.41.59014006001.59011307.41.59014006001.59011307.41.5901P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)1413.5860.0166928.880.30611.7632176.1411490.88251008881035.357088086254.9720.0164173.920.23451.8448129.9611310.8431647694974.763515027821.9960.01623174.090.17491.920293.961116.10.8121958701925.135795296510.94920.01613680.12951.9825681105.10.7895626084887.666824961514.1230.016727.80.30911.76178.151149.75.2120.0164270720.23771.8409131.961131.82.1070.01624165.450.17831.915796.9611171.00790.0161469.990.13311.9775701105.9-0.537-0.000011.08-0.0030.0032-2.01-0.7-0.24-0.00001-6998.08-0.00320.0039-2-0.8-0.111-0.000018.64-0.00340.0045-3-0.9-0.0587-0.00001-1.99-0.00360.005-2-0.80.016697709528.04737430170.30841284921.7607329609177.68960893851149.53966480450.01641770955469.08782122910.23696703911.8417932961131.50189944131131.61675977650.0162377095167.42899441340.17752122911.916730726396.2728491621116.79385474860.016137709569.53418994410.1322754191.978645251469.54189944131105.7167597765P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)400381.540.6161419.031204.4424.16390049750.6217022886400381.540.6161419.031204.4424.16390049750.6217022886400381.540.6161419.031204.4424.16390049750.6217022886400381.540.6161419.031204.4424.16390049750.6217022886401.640.6222424.621204.6401.640.6222424.621204.6401.640.6222424.621204.6401.640.6222424.621204.6-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.20.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.583681592P4(psi)x4H4(Btu/lbm)P4(psi)x4H4(Btu/lbm)P4(psi)x4H4(Btu/lbm)P4(psi)x4H4(Btu/lbm)140.2157165193387.333720260150.2397363875371.265823166120.2553924988356.906258902810.2650752092344.2061673002Respuestahx3hP3(psi)Respuestahx3Respuestahx3Respuestahx30.3080070120.88251008880.308007012140.37661106150.84316476940.43279957070.81219587010.47522194270.78956260840.376611061550.432799570720.47522194271Problema 9.2P3(psi)T2(F)P2(psi)P2(psi)P2(psi)2600100200400P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)1006001.75861329.61.75862006001.67761322.61.67764006001.59011307.41.5901P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3H3(Btu/lbm)21.9960.01623174.090.17491.920293.961116.10.90907896581024.007029450621.9960.01623174.090.17491.920293.961116.10.862506083976.478424308321.9960.01623174.090.17491.920293.961116.10.8121958701925.13579529652.1070.01624165.450.17831.915796.9611172.1070.01624165.450.17831.915796.9611172.1070.01624165.450.17831.915796.961117-0.111-0.000018.64-0.00340.0045-3-0.9-0.111-0.000018.64-0.00340.0045-3-0.9-0.111-0.000018.64-0.00340.0045-3-0.90.0162377095167.42899441340.17752122911.916730726396.2728491621116.79385474860.0162377095167.42899441340.17752122911.916730726396.2728491621116.79385474860.0162377095167.42899441340.17752122911.916730726396.2728491621116.7938547486P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H1(Btu/lbm)S1(Btu/lbmR)10096.160.4706295.61186.5300.38490547260.4766614925200195.730.5416353.581198358.49348258710.5473859701400381.540.6161419.031204.4424.16390049750.6217022886103.050.4772300.811187.7207.740.5479358.931198.8401.640.6222424.621204.6-6.89-0.0066-5.21-1.2-12.01-0.0063-5.35-0.8-20.1-0.0061-5.59-0.20.4766614925300.38490547261187.60208955220.5473859701358.49348258711198.73472636820.6217022886424.16390049751204.583681592Respuestahx3hx3hx30.29691846940.90907896580.35900760910.8625060830.43279957070.8121958701hP2(psi)0.29691846941000.35900760912000.4327995707400Problema 9.3P3(psi)P2(psi)T2(F)T2(F)T2(F)T2(F)240044560010001400P2(psi)P(psi)T(F)S(Btu/lbmR)H(Btu/lbm)400381.544401.4891204.4401.644451.48431204.6-20.1-50.0047-0.24451.48468348261204.583681592P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)400444.5920398011.48468348261204.5836815921.48468348264006001.59011307.41.590140010001.76321523.31.763240014001.89551741.91.8955P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3humedad3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3humedad3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3humedad3H3(Btu/lbm)P3(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x3humedad3H3(Btu/lbm)21.9960.01623174.090.17491.920293.961116.10.75051545310.2494845469861.143177589921.9960.01623174.090.17491.920293.961116.10.81219587010.1878041299925.135795296521.9960.01623174.090.17491.920293.961116.10.91172384550.08827615451026.706184804421.9960.01623174.090.17491.920293.961116.10.98779288730.01220711271104.33623987022.1070.01624165.450.17831.915796.9611172.1070.01624165.450.17831.915796.9611172.1070.01624165.450.17831.915796.9611172.1070.01624165.450.17831.915796.961117-0.111-0.000018.64-0.00340.0045-3-0.9Wturbina(Btu/lbm)-0.111-0.000018.64-0.00340.0045-3-0.9Wturbina(Btu/lbm)-0.111-0.000018.64-0.00340.0045-3-0.9Wturbina(Btu/lbm)-0.111-0.000018.64-0.00340.0045-3-0.9Wturbina(Btu/lbm)0.0162303604173.77864864860.17502252251.920037837894.06810810811116.1324324324343.44050400210.0162377095167.42899441340.17752122911.916730726396.2728491621116.7938547486382.26420470350.0162377095167.42899441340.17752122911.916730726396.2728491621116.7938547486496.59381519560.0162377095167.42899441340.17752122911.916730726396.2728491621116.7938547486637.5637601298P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H4(Btu/lbm)Wbomba(Btu/lbm)H1(Btu/lbm)QC(Btu/lbm)Wneto(Btu/lbm)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H4(Btu/lbm)Wbomba(Btu/lbm)H1(Btu/lbm)QC(Btu/lbm)Wneto(Btu/lbm)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H4(Btu/lbm)Wbomba(Btu/lbm)H1(Btu/lbm)QC(Btu/lbm)Wneto(Btu/lbm)P1(psi)P(psi)SL(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)H4(Btu/lbm)Wbomba(Btu/lbm)H1(Btu/lbm)QC(Btu/lbm)Wneto(Btu/lbm)400381.540.6161419.031204.494.06810810811.195377598695.26348570671109.3201958853342.2451264035400381.540.6161419.031204.496.2728491621.195918867897.46876802981209.9312319702381.0682858357400381.540.6161419.031204.496.2728491621.195918867897.46876802981425.8312319702495.3978963278400381.540.6161419.031204.496.2728491621.195918867897.46876802981644.4312319702636.367841262401.640.6222424.621204.6401.640.6222424.621204.6401.640.6222424.621204.6401.640.6222424.621204.6-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.2-20.1-0.0061-5.59-0.20.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.5836815920.6217022886424.16390049751204.583681592Respuestahhumedad3Respuestah0.1878041299Respuestahhumedad3Respuestahhumedad30.30851789020.24948454690.31495036720.18780412990.34744497470.08827615450.38698355330.0122071127hT2(F)0.30851789024450.31495036726000.347444974710000.38698355331400Problema 9.4P1(psi)T1(F)P2(psi)P3(psi)T3(F)P4(psi)40060090906002P1(psi)T1(F)S1(Btu/lbmR)H1(Btu/lbm)S2(Btu/lbmR)4006001.59011307.41.5901P2(psi)P(psi)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x2H2(Btu/lbm)9089.640.4641.6116290.41185.20.98497027831172.79882955696.160.47061.6059295.61186.5-6.52-0.00660.0057-5.2-1.30.46908826821.6072055866294.40893854751186.2022346369P3(psi)T3(F)S3Btu/lbmR)H3(Btu/lbm)S4(Btu/lbmR)906001.77071330.21.7707P4(psi)P(psi)VL(ft3/lbm)VV(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)x4H4(Btu/lbm)21.9960.01623174.090.17491.920293.961116.10.91603614951031.10698157682.1070.01624165.450.17831.915796.961117-0.111-0.000018.64-0.00340.0045-3-0.90.0162377095167.42899441340.17752122911.916730726396.2728491621116.7938547486P1(psi)P(psi)HL(Btu/lbm)H4(Btu/lbm)400381.5496.272849162401.64-20.1Respuestahx40.35147471110.9160361495Problema 9.5P2(psi)T2(F)P5(psi)P3(psi)P4(psi)40060029016P2(psi)T2(F)S2(Btu/lbmR)H2(Btu/lbm)S3(Btu/lbmR)S4(Btu/lbmR)S5(Btu/lbmR)4006001.59011307.41.59011.59011.5901P3(psi)P(psi)VL(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)S3(Btu/lbmR)x3H3(Btu/lbm)H10(Btu/lbm)9089.640.017660.4641.6116290.41185.21.59010.98152856331168.7475151512290.687116564496.160.017710.47061.6059295.61186.5-6.52-0.00005-0.00660.0057-5.2-1.30.01766276070.46436441721.6112852761290.68711656441185.2717791411P10(psi)VL(ft3/lbm)Wbomba(Btu/lbm)H1(Btu/lbm)900.01766276071.0132442738291.7003608382P4(psi)P(psi)VL(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)S4(Btu/lbmR)x4H4(Btu/lbm)H8(Btu/lbm)1615.5920.016740.31661.752183.191151.61.59010.88829526991043.9773878555184.480037641217.1860.016780.32411.7442188.231153.4-1.594-0.00004-0.00750.0078-5.04-1.80.01675023840.31851969891.7500035132184.48003764121152.060727729P8(psi)VL(ft3/lbm)Wbomba(Btu/lbm)H9(Btu/lbm)160.01675023840.2293752688184.7094129099P5(psi)P(psi)VL(ft3/lbm)SL(Btu/lbmR)SV(Btu/lbmR)HL(Btu/lbm)HV(Btu/lbm)S3(Btu/lbmR)x5H5(Btu/lbm)H6(Btu/lbm)21.9960.016230.17491.920293.961116.11.59010.8113047969923.510577183494.47191969892.1070.016240.17831.915795.961117-0.111-0.00001-0.00340.0045-2-0.90.01623255960.17577026351.919048180794.47191969891116.3303638645P6(psi)VL(ft3/lbm)Wbomba(Btu/lbm)H7(Btu/lbm)20.01623255960.042054155994.5139738547y3y4y5Wbom(tota)l(Btu/lbm)Wturbina(Btu/lbm)Wneto(Btu/lbm)Qc(Btu/lbm)0.10769674810.10547527160.78682798031.2846736984246.5993052425245.3146315441015.6996391618Respuestah0.2415228106

WIL

hpresinrendimiento trmicoRendimiento Vs presin

Hoja3

hPresinRendimientoRendimiento Vs. P2

EJEM 1

hRendimientoTemperaturaRendimiento Vs Temperatura T2

EJEM 2Ejemplo 1ancho(ft)largo(ft)alto(ft)Tex-Tin(F)aislante(in)aislantet(horas)10128604poliuretano24moldeadoaislantek(Btu/ft2.F.inTe-Trefri(F)U(Btu/ft2.da)A(ft2)Q1(Btu/da)poliuretano0.2607247233984moldeadoRespuestaQ1(Btu/da)33984Ejemplo 2techoTex-Tin(F)correccin(Tex-Tin(F))corregidoU(Btu/ft2.da)A(ft2)Q1(Btu/da)verde70158510212012240RespuestaQ1'(Btu/da)12240Ejemplo 3aislamientoespesor(in)Trefrigeracin(F)Tverano(F)Tver-Trefri(F)U(Btu/ft2.da)A(ft2)Q1(Btu/da)corcho3406020481205760prensadoRespuestaQ1''(Btu/da)5760Ejemplo 4Trefrigeracin(F)Vrefrig(ft3)Texterior(F)HR(aire)Ncambios de aireVaire(ft3/da)U'(Btu/ft3)Q2(Btu/da)201500905011165002.6243230RespuestaQ2(Btu/da)43230Ejemplo 5productoM(lbm)Tproducto(F)Trefrigeracin(F)Tcongelacin(F)Cprod(alto)(Btu/lbmF)Qsen(alto)(Btu/da)lf(Btu/lbm)Qfusin(Btu/da)Cprod(bajo)(Btu/lbmF)Qsen(bajo)(Btu/da)Q3(Btu/da)pescado1200060-10280.8633024012214640000.452052001999440RespuestaQ3(Btu/da)1999440Ejemplo 7productoM(lbm)Talmacenamiento(F)U''(Btu/lbm.da)Q4(Btu/da)chanpiones8000407.862400RespuestaQ4(Btu/da)62400

recalentador12334calderocondensadorregenerador123456regenerador78910108una cmara frigorfica tiene dimensiones exteriores de 10 ft de ancho por 12 ft de largo por 8 ft de alto. La diferencia de temperaturas entre el exterior y el refrigerador es de 60F. Las paredes y el plafn estn aisaldos con 4 in de poliestireno moldeado Cul ser la ganancia de calor a travs de las paredes y el plafn en 24 horas? No se tiene en cuenta el efecto solar.El techo de una cmara refrigerada est expuesto al sol. La diferencia de temperatura entre el exterior y la cmara es de 70F. El techo est pintado de verde. Qu diferencia de temperatura se debe usar para calcular la transmisin de calor del techo?Una losa de piso no calentada y colocada sobre el terreno tiene un aislamiento de plancha de corcho prensado de 3 in. El cuarto para almacenamineto en fro, situado en Des Miones, Iowa, se amantiene a 40F. Cul ser la ganancia trmica del piso por ft2 de rea ?Un cuarto para almacenamiento en fro a 20F, tiene un volumen de 1500 ft3. Las condiciones del aire exterior son de 90F y 50% de HR (humedad relativa). El almacenamiento del producto es relativamente corto. Calcular la carga calrica de infiltracin a travs de la puerta.Una cmara de congelacin recibe 12000 lbm de pescado a 60F para ser enfriado hasta -10F en 24 horas. Calcular la carga de enfriamiento del productoUn recinto para el almacenamiento contien 8000 lbm de chapiones a 40F. Cul es la carga diaria debida al calor de respiracin?

Problema muestramuestram(kg)Tp(C)personas que entrannp(persona)hp(h/da)ventiladoresnvPpotencia(W)alubias verdes300020131250exterioresTe(C)HRefocos de iluminacinnf(focos)Pfocos(W)hf(h/da)3560flurescentes2603interioresTi(C)HRiaislamientoespesor(cm)m(kg/m3)595espuma de poliestireno1064cmaralongitud(m)ancho(m)altura(m)funcionamientotiempo(h/da)432.516SOLUCION1) Transmisin de calor atravs de las paredes y techosaislamientoespesor(cm)m(kg/m3)Tablak(W/m2K)A(m2)DT(C)Q1(W)espuma de poliestireno106410.335930584.12) Infiltracin de airecmaralongitud(m)ancho(m)altura(m)Vcmara(m3)Tablan(reno/da)432.530317.5cont. calorTe(C)Ti(C)HReTablaDh(Kj/m3)Q2(kJ/da)Q2(W)35560495.450085579.693) Calor por iluminaciniluminacinnf(focos)Pfocos(W)hf(h/da)flurescenteP(W)Q3(W)flurescentes26031.2515018.754) Calor por personasnp(persona)hp(h/da)Ti(C)Tablaqp(W)Q4(W)1355240305) Calor liberado por los ventiladoresventiladoressupuesto(nv)tiempo(h/da)Psupuesto(W)Q5(W)216250333.33333333336) Calor de congelacin de los alimentosmuestraTalmace(C)Hralmace(%)Tablace(kJ/kg.K)DT(C)prdida(%)m(kg)Q6(W)alubias verdes59563.81151030002182.817) Calor de respiracin de los alimentosmuestram(kg)Tablacrespiracin(kJ/kg.da)Q7(W)alubias verdes3000611.6402.78Carga efectiva (W)factor seg(%)Carga total (W)4131.46104544.61Po nom refri (W)6816.92

Calcular la carga trmica de una cmara para refrigeracin de alubias verdes con una carga diaria de 3000 kg/da que entra a una temperatura de 20C. La temperatura del aire es de 35C con una humedad relativa del 60% y la del aire interior de 5C con una humedad relativa del 95%. Una persona entra cada da durante 3 horas y la cmara est iluminada con dos tubos fluorescentes de 60 W durante estas 3 h/da. Las dimensiones exteriores de la cmara son: longitud 4 m, anchura 3 m y una altura 2.5 m.Tiene un aislamiento de espuma de poliestireno de 10 cm de 64 kg/m3 de una masa volumtrica en todos las paredes. Suponer una duracin de 16 h/diarias de funcionamiento. Suponer que todos los ventiladores tienen una potencia de 250 W.

Ejemplo 2cmaralargo(m)exancho(m)exaltura(m)exantecmaralargo(m)exancho(m)exaltura(m)ex22.3413.794.95146.5largo(m)inancho(m)inaltura(m)inVinterior(m3)largo(m)inancho(m)inaltura(m)inVinterior(m3)22.1413.594.81444.236484.8513.74.8318.936productoscarne(%)pescado(%)verduras(%)mariscos(%)varios(%)Tinterior(C)Texterior(C)congelados2520151030-2032distribucinn anaqueles1n anaqueles2n palets1n palets2N total paletsdistribucinn anaqueles3n palets3N total paletsparedes17321111centro14284densidadescarnepescadoverdurasmariscosvariosventacarne(%)pescado(%)verduras(%)mariscos(%)varios(%)(kg/m3)500450400350500productos2520151030densidadr(kg/m3)hpalet(m)anaquel 1largo(m)ancho(m)Vanaquel 1(m3)anaquel 2largo(m)ancho(m)Vanaquel 2(m3)Vcarga(m3)media carga46011.81.22.161.511.5carga total(kg)168249.6velocidadi(m/s)velocidade(m/s)hi(kcal/m2.h.C)he(kcal/m2.h.C)aislantel(kcal/m.h.C)esp(cm)suelol(kcal/m.h.C)esp(cm)densi(kg/m3)148.919.7panel prefabricado0.016310hormig armado1.41540hormig en masa0.475poliuretano inyectado0.02515Ksuelo(kcal/m2.h.C)Ktecho(kcal/m2.h.C)Kparedes(kcal/m2.h.C)superficieAsuelo(m2)Atecho(m2)Apared(norte)(m2)Apared(sur)(m2)Apared(este)(m2)Apared(oeste)(m2)Tmx(verano)(C)Texterior(C)Tantecmara(C)Tsuelo(C)0.1543328020.1630.163exterior308.0686308.0686107.232107.23266.19266.1923227520Qsuelo(kcal/da)Qpared(ante)(kcal/da)Qtecho+paredes(kcal/da)Qtotal(kcal/da)Qtotal(W)45643.28662418456473.5776108245.2598544160362.1240785855746.3094461493Qrenovacin(kcal/da)Vinterior(m3)Tinterior(C)Tantecmara(C)HRTabla 4DHaire(kJ/m3)DHaire(kcal/m3)Tabla 3Vinterior(m3)V(m3)n1444.23648-2057046.111.0287081341444.2364810001.915001.54-5000.361.5801497344

Una cmara para productos envasados congelados ser ubicada en el interio de una nave, con antecmara. Las dimensiones de la cmara son:- Medidas exteriores:22.34 m de largo - 13.79 m de ancho - 4.9 m de altura- Medidas interiores: 22.14 m de largo - 13.59 m de ancho - 4.8 m de altura- Volumen interior de la cmara: 1.444 1.45 m3 (redondeando)Las dimensiones de la antecmara son:- Medidas exteriores:5 m de largo - 14 m de ancho - 6.5 m de altura- Medidas interiores: 4.85 m de largo - 13.7 m de ancho - 4.8 m de altura- Volumen interior de la cmara: 318.9 m3 320 m3 (redondeando) . La estiba se realizar medienta palets normalizados. Se calcula un movimiento de salida semanal de producto de la cmara de 40 a 50 (toneladas mtricas) con la utilizacin de carretillas elevadoras. Los productos congelados sern variados: carne (25%), pescado (20%), verduras (15%); mariscos (10%) y productos variados el resto (30%). Se supondr 18 horas diarias de funcionamiento. El calor desprendido por los motores de los ventiladores y descarches (aparatos para quitar los descarches) se estimar en un 30%. A las prdidas se aadir un 10% por medidad de seguridad. Supondremos que la temperatura en el interior de la cmara es de -20C y la temperatura exterior de 32C.