工程热力学课后习题答案.pdf

112 9-1 3 1 140m /h V = p 1 =0.1MPa t 1 =27 2 0.6MPa p = kW =1.4 n=1.2 1 2 11 1 63 5 5 ln 0.6MPa 0.1 10 Pa 140m /h ln 250.8 10 J/h 0.1MPa 250.8 10 J/h 6966.7J/h 6.97KW 3600s/h T p Wp V p P = = = = 2 4 . 1 = KW W N h J p p v p s W s 11 . 9 3 . 9108 3600 10 9 . 327 10 9 . 327 1 6 140 10 1 . 0 1 4 . 1 4 . 1 1 ) ( 1 5 5 4 . 1 1 4 . 1 6 1 1 2 1 1 = = = = = = 3 KW W N h J p p V p n n W n n n n t 12 . 8 10 12 . 8 3600 10 3 . 292 10 3 . 292 1 6 140 10 1 . 0 1 2 . 1 2 . 1 1 ) ( 1 3 5 5 2 . 1 1 2 . 1 6 1 1 2 1 1 , = = = = = = 9-2 3 1 1 1 032 . 0 , 50 , 1 . 0 m V C t MPa p = = = 3 2 2 012 . 0 , 32 . 0 m V MPa p = = 1 2 3 4 1 n n v p v p 2 2 1 1 = Q 186 . 1 012 . 0 032 . 0 ln 1 . 0 32 . 0 ln ) ln( ) ln( 2 1 1 2 = = = V V p p n 2 K p p T T n n 82 . 387 ) 1 . 0 32 . 0 ( ) 50 15 . 273 ( ) ( 186 . 1 1 186 . 1 1 1 2 1 2 = + = = 3 kJ J p p V p n W n n n 443 . 3 8 . 3442 ) 1 2 . 3 ( 032 . 0 10 1 . 0 1 186 . 1 1 1 ) ( 1 1 186 . 1 1 186 . 1 6 1 1 2 1 1 = = = = 113 4 ) ( 826 . 0 718 . 0 1 186 . 1 4 . 1 186 . 1 1 K kg kJ c n n c V n = = = kJ mq Q kg T R v p m kJ T c q n n g n n 84 . 1 42 . 53 0345 . 0 0345 . 0 15 . 323 287 032 . 0 106 1 . 0 42 . 53 ) 15 . 323 28 . 387 ( 826 . 0 1 1 1 = = = = = = = = = Q 9-3 150 , 20 , 1 . 0 1 1 C t MPa p = = h m 3 250 h kg 465 14 1 2 s kg T R V p q kW t c q Q g a m W m w 08254 . 0 15 . 293 287 3600 250 10 1 . 0 5715 . 7 14 187 . 4 3600 465 6 1 1 1 , , = = = = = = a W Q Q = Q kg kJ q Q q ma W 73 . 91 08254 . 0 5715 . 7 = = = ) ( 1 1 2 T T c n n q v = 0317 . 1 73 . 91 ) 20 150 ( 728 . 0 ) ( 1 1 2 = = = q T T c n n v 20 . 1 = n 1 n n n n p T p T 1 2 2 1 1 1 = MPa T T p p n n 90 . 0 ) 15 . 293 15 . 273 150 ( 1 . 0 ) ( 1 2 . 1 2 . 1 1 1 2 1 2 = + = = 2 t w h q + = kW w q N kg J p p T R n n w kW w q N kg kJ q T T c q h w w c a m n n g c c a m p t c 4 . 18 10 23 . 2 0825 . 0 10 23 . 2 1 ) 1 . 0 9 . 0 ( 15 . 293 287 1 2 . 1 2 . 1 1 ) ( 1 3 . 18 25 . 222 08254 . 0 25 . 222 73 . 91 ) 20 150 ( 004 . 1 ) ( 5 , 5 2 . 1 1 2 . 1 1 1 2 1 , 1 2 = = = = = = = = = = + = = = = 9-4 6% C MPa 27 , 1 . 0 MPa 5 . 0 n 1 =1.4 n 2 =1.25 n 3 =1, 06 . 0 = h c V V 5 1 . 0 5 . 0 = = ) 1 ( 1 1 = n h c v V V 76 . 0 ) 1 5 ( 06 . 0 1 843 . 0 ) 1 5 ( 06 . 0 1 871 . 0 ) 1 5 ( 0006 1 3 , 25 . 1 1 2 , 4 . 1 1 1 , = = = = = = v v v 114 9-5 7 3 009 . 0 m 0.06 750r/min( ) 1.3 1 2 h kg 3 kW 4 C t MPa p = = 20 , 1 . 0 1 1 3 009 . 0 m V h = 7 = 06 . 0 = 3 . 1 = n 1 792 . 0 ) 1 7 ( 06 . 0 1 ) 1 ( 1 ) 1 ( 1 3 . 1 1 1 1 = = = = n n h c v V V 2 3 00713 . 0 009 . 0 792 . 0 m V V h V es = = = h kg v V q kg m p T R es m g v 56 . 3813 08413 . 0 60 750 00713 . 0 08413 . 0 10 1 . 0 15 . 293 287 1 3 6 1 1 1 = = = = = = 3 kg J v p n n w n n c 5 3 . 1 1 6 1 1 1 10 264 . 1 ) 1 7 ( 08413 . 0 10 1 . 0 1 3 . 1 3 . 1 ) 1 ( 1 = = = kW s J w q N c m 4 . 13 10 39 . 13 10 264 . 1 3600 56 . 3813 3 5 = = = = 4 K T T n n 32 . 459 7 15 . 293 3 . 1 1 3 . 1 1 1 2 = = = kW q q Q kg kJ T c n n q n m n V n 13 . 42 ) 77 . 39 ( 3600 56 . 3813 77 . 39 ) 15 . 293 32 . 459 ( 718 . 0 1 3 . 1 4 . 1 3 . 1 1 = = = = = = 4 W 1 W 2 W 116 5 h kJ 1 2 p MPa p p p 5 . 0 5 . 2 1 . 0 3 1 2 = = = 2 K p p T T T n n 33 . 400 ) 1 . 0 5 . 0 ( 15 . 290 ) ( 25 . 1 1 25 . 1 1 1 2 1 3 2 = = = = C t t = = 18 . 127 3 2 3 h kg T R V p q h m p nRT V g ma 64 . 646 15 . 290 287 49 . 538 106 1 . 0 49 . 538 10 1 . 0 15 . 290 5 . 8314 4 . 22 500 1 1 1 3 6 1 1 1 = = = = = = 3 1 1 03590 . 0 60 250 49 . 538 60 250 m V V = = = 3 1 2 1 2 00718 . 0 03590 . 0 5 1 m V p p V = = = 4 h kJ p p V p n n W W n n 5 25 . 1 1 25 . 1 6 1 1 2 1 1 2 1 10 022 . 1 1 5 49 . 538 10 1 . 0 1 25 . 1 25 . 1 1 ) ( 1 = = = = kW W N h kJ w W W W c c 8 . 56 3600 10 044 . 2 3600 10 044 . 2 10 022 . 1 2 2 5 5 5 1 2 1 = = = = = = + = 5 = = + = c t w H H W H Q 1 3 h kJ 5 5 10 33 . 1 10 044 . 2 ) 15 . 290 33 . 400 ( 004 . 1 64 . 646 = 9-9 95 . 0 = v 3 14m C t atm p = = 21 , 1 MPa 52 . 0 1 2 1 132 . 5 101325 . 0 52 . 0 1 2 = = = p p n=1.4 ) 1 ( 1 1 = n h c v V V Q 023 . 0 1 132 . 5 95 . 0 1 1 1 4 . 1 1 1 = = = n v h c V V 2 1 ) ( 1 1 1 2 1 = n n c p p V p n n W kW s J 3 . 49 7 . 49289 1 132 . 5 60 14 101325 1 4 . 1 4 . 1 4 . 1 1 4 . 1 = = = 117 9-10 D=200mm S=300mm C t KPa p = = 20 , 97 1 1 MPa p 55 . 0 2 = n=1.3 500r/min 05 . 0 = 1 2 3 4 3 2 2 009425 . 0 3 . 0 2 . 0 4 4 m s D Vh = = = 1 V v 05 . 0 = = h c V V Q 3 000471 . 0 05 . 0 m V V h c = = 3 V V c = 86 . 0 1 ) 09 . 0 55 . 0 ( 05 . 0 1 ) 1 ( 1 008106 . 0 00179 . 0 009896 . 0 009896 . 0 000471 . 0 009425 . 0 00179 . 0 ) 10 97 55 . 0 ( 000471 . 0 ) ( ) ( 3 . 1 1 1 3 4 1 3 1 3 3 . 1 1 3 1 1 2 3 1 4 3 3 4 = = = = = = = + = + = = = = = n h c v c h n n V V m V V V m V V V m p p V p p V V 86 . 0 009425 . 0 008106 . 0 = = = c v V V 2 K p p T T n n 52 . 437 ) 097 . 0 55 . 0 ( 15 . 293 ) ( 3 . 1 1 3 . 1 1 1 2 1 2 = = = C t = 37 . 164 2 3 h kg s kg T R q p q g V m 4 . 280 07788 . 0 60 15 . 293 287 500 008106 . 0 10 97 3 1 1 = = = = 4 kW s J p p V p n n W n n c 0 . 14 10 398 . 1 1 ) 097 . 0 55 . 0 ( 60 500 008106 . 0 10 97 1 3 . 1 3 . 1 1 ) ( 1 4 3 . 1 1 3 . 1 3 1 1 2 1 = = = = & 9-11 C t MPa p = = 20 , 1 . 0 1 1 1200kg MPa p 6 . 0 2 = 0.85 2 K To 15 . 293 = : 1 1 2 1 2 1 2 1 2 T T T T h h h h s s cs = = K p p T T s 12 . 489 ) 1 . 0 6 . 0 ( 15 . 293 ) ( 4 . 1 1 4 . 1 1 1 2 1 2 = = = 118 C t K T T T T cs s = = + = + = 6 . 250 70 . 523 85 . 0 15 . 293 12 . 489 15 . 293 2 1 2 1 2 kW h h q W m c 0 . 4630 ) 20 6 . 250 ( 004 . 1 60 1200 ) ( 1 2 = = = & 2 f g s s s s + = ) ( 1 2 Q 0 = f s s kJ S T I s K kJ T T c q p p R T T c q S S S g o s p m g p m g 1 . 402 3717 . 1 15 . 293 ) ( 3717 . 1 12 . 489 70 . 523 ln 004 . 1 20 ln ln ln 2 2 1 2 1 2 1 2 = = = = = = = = & & & & & 9-12 C t MPa p = = 27 , 1 . 0 1 min 6 . 516 3 m MPa p 1 2 = 350 1 2 3 : 1 cs 865 . 0 27 350 15 . 300 50 . 579 50 . 579 ) 1 . 0 1 ( ) 15 . 273 27 ( ) ( 4 . 1 1 4 . 1 1 1 2 1 2 1 2 1 2 1 2 1 2 = = = + = = = = cs s s s s cs K p p T T T T T T h h h h Q 2 1 2 S S S S g f & & & & = + 0 = f S Q ) ( 729 . 0 50 . 579 15 . 273 350 ln 004 . 1 15 . 300 287 60 6 . 516 10 1 . 0 ln ln 6 2 2 1 1 1 2 2 1 2 s K kJ T T c T R V p T T c q S S S s p g s p m g = + = = = = & & & & 3 kW T T c T R V p h h q W p g m c 3 . 3241 ) 27 350 ( 004 . 1 15 . 300 287 60 6 . 516 10 1 . 0 ) ( ) ( 6 1 2 1 1 1 1 2 = = = = & & 9-13 MPa p 1 . 0 1 = C t = 17 1 C t = 207 2 MPa p 4 . 0 2 = min 60 kg 185kW : K p p T T s 15 . 431 ) 1 . 0 4 . 0 )( 15 . 273 17 ( ) ( 4 . 1 1 4 . 1 1 1 2 1 2 = + = = C t s = 158 2 2 2 t t s c W & 185kw % 1 . 3 185 185 76 . 190 = 9-14 MPa 0 . 6 A 0.9 B 1.25 C t MPa p o = = 27 , 1 . 0 0 A kg kJ T T c h h w C t K T T T T K T T p p p c cs s s 7 . 743 ) 15 . 300 84 . 966 ( 004 . 1 ) ( 77 . 767 92 . 1042 9 . 0 15 . 300 840 . 966 15 . 300 84 . 966 60 ) 27 15 . 273 ( 60 1 . 0 0 . 6 1 2 1 2 2 1 2 1 2 4 . 1 1 4 . 1 1 1 2 1 2 = = = = = = + = + = = + = = = = = & B 746 . 7 1 . 0 6 1 2 = = = = p p h L K T T T n n L a 02 . 452 746 . 7 15 . 300 25 . 1 1 25 . 1 1 1 2 = = = = C t t a = = 87 . 178 2 kg kJ n T nR w w w w n n g L c h c L c c 8 . 435 ) 1 746 . 7 ( 15 . 300 287 1 25 . 1 25 . 1 2 ) 1 ( 1 2 2 25 . 1 1 25 . 1 1 1 , , , = = = = + = & B A T T 1 1 2 2 B c A c w w , , B A A A