Thermodynamics Lecture Series

Transcription

1 Therodynac Lecture Sere Dynac Enery Traner Heat, ork and Ma ppled Scence Educaton Reearch Group (SERG) Faculty o ppled Scence Unvert Teknolo MR Pure utance Properte o Pure Sutance- Revew CHPTER eal: drjjlanta@hotal.co Quote Exaple: tea power cycle. Stea Power Plant "Good judent coe ro experence. Experence coe ro ad judent - nonyou Con Product Fuel r Pup Stea Turne Heat Exchaner Mechancal Enery to Generator "The root o educaton are tter, ut the rut weet." -rtotle Cooln ater Syte Boundary or or Therodynac naly Phae Chane o ater Phae Chane o ater C. lqud Q n H O Sat. lqud Q n Sat. Lq. Q n Q n ater nteract wth theral enery T 50 C Q n T, C kpa 3 kpa 00 kpa 5 kpa, 50 C 3 [ + x 3 /k Copreed lqud: Good etaton or properte y takn y y can e ether,, u, h or.

2 Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. FIGURE -6 T-v dara o T v dara: Multple P contant - preure phae-chane procee o a pure utance at varou preure (nuercal value are or water) FIGURE -8 T-v dara o a pure utance. Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. T v dara: Multple P - -3 Phae Chane o ater - Preure Chane Phae Chane o ater- Preure Chane P 4.46 kpa P 4.46 kpa T at@00 kpa C P at@30 C 4.46 kpa P 4.46 kpa P kpa 00 P, kpa 30 C T at@00 kpa C P at@30 C 4.46 kpa n 30 C n 30 C n 3 [n + x n 30 C n 4 30 C 4.46 n 5 30 C C. lqud Sat. lqud Sat. Lq. ater when preure 30 C 3 30 C 5, 3 /k Copreed lqud: Good etaton or properte y takn y y can e ether,, u, h or. P, C,090, Phae Chane o C 00 C 00 C 0 C P- dara wth repect to the aturaton lne, 3 /k Saturated Lqud- Mxture Phae:, V,, n, u, h Lqud Phae:, V,, n, u, h Mxture:, V,, n,, u, h, x t Gven the preure, P, then T T at, y < y <y + av av + t x Sat. Lq. Mxture qualty x t Dvde y + total a, t ( t ) + x x + x

3 Saturated Lqud- Mxture Gven the preure, P, then T T at, y < y <y CHPTER 3 Phae:, V,, n, u, h Lqud Phae:, V,, n, u, h Mxture:, V,, n,, u, h, x + x y y + xy y Sat. Lq. Mxture qualty x t y y y can e n,, u, h Enery Traner y Heat, ork, and Ma Goal: Identy or o enery nteracton and way o repreentn t n therodynac procee I x known or ha een deterned, ue aove relaton to nd other properte. I ether n, u, h are known, ue t to nd qualty, x. Introducton Introducton Ojectve:. Identy the type o dynac enere nteractn wth a yte.. Dtnuh the derence and relate etween heat traner and theral enery. 3. rte the derent yol and the conventon ued to repreent heat traner. 4. Derentate etween heat traner and work done. Ojectve: 5. rte the yol and conventon ued or work done. 6. Otan a atheatcal relaton repreentn echancal work done or any yte. 7. Otan the aount o work done ro a P V or P - n raph. 8. rte down the relatonhp etween a and volue low rate. Ojectve: Introducton 9. Otan a atheatcal relaton repreentn a low rate n ter o the a velocte and the yte nlet or ext area. 0.rte the pecc enery carred y a lown a..ue all atheatcal relaton and raphn kll to olve prole nvolvn nteracton enere. SOD 5 C q n Enery Traner -Heat Traner q ou t Sat. Lq. Q n Oven Na Leak Le 0 C q n 00 C 3-3

4 FIGURE 3-9 Specyn the drecton o heat and work. Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. Iochorc Proce Cloed Syte Ioarc Proce Cloed Syte Syte expand, volue ncreae T 50 C C. lqud H O Sat. lqud Sat. Lq. Q n Q n Q n Q n Q n 3- Source o theral enery Ioarc Proce Cloed Syte Syte expand, volue ncreae T 50 C Syol and Conventon Heat traner Total heat entern, Q n 00, 5 k Specc heat Qn 00 qn 0 5 k k C. lqud H O Sat. lqud Sat. Lq. Q n Q Q n, q, n n Q, n or k k Source o theral enery Rate o heat traner heat allowed to nteract or 50 econd Q 00 n k 50 Q Syol and Conventon Heat traner Total heat leavn, Q 0, 5 k Specc heat q Q k 50 Q Q 0 4 5k k Rate o heat traner heat allowed to nteract or 50 econd Syol and Conventon Heat traner Net heat traner Q Q Net pecc heat traner q q Q, n Qn Q net Qnet, Qn Q 60 5 k n net, n k Net rate o heat traner heat allowed to nteract or 50 econd Q net, n Q. k Q n 4

5 Exaple: tea power cycle. Con Product Fuel r Q n Pup Stea Power Plant Stea Turne Heat Exchaner Mechancal Enery to Generator Mechancal work: Pton ove up Boundary work done y yte Enery Traner ork Done pw, Electrcal work done on yte No heat traner T ncreae ater oe te n Q Cooln ater Syte Boundary or or Therodynac naly Sat. lqud e V e VDt, Voltae, V Syol and conventon or ork Iotheral Proce Syte expand, volue ncreae-oundary work done P 4.46 kpa C. lqud Sat. lqud Sat. Lq. P 4.46 kpa P 4.46 kpa T at@00 kpa C P at@30 C 4.46 kpa P kpa ater when preure reduced no theral enery or heat Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. Boundary ork,, ork done nvolve orce ovn an oject n the drecton o oveent Fnal, n FIGURE 3-9 a doe a derental aount o work d a t orce the pton to ove y a derental aount d. δ F d Total work done y yte to expand ro ntal to nal tate δ δ, + δ, δ, n δ F d + F d +... Intal + F d n n Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. FIGURE 3-9 a doe a derental aount o work d a t orce the pton to ove y a derental aount d. d approache zero δ F d Boundary ork,, Preure exerted on a urace the rato o orce appled w.r.t. the area o urace F P, kpa Fnal, n Intal Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. FIGURE 3-9 a doe a derental aount o work d a t orce the pton to ove y a derental aount d. Boundary ork,, Fnal, n Preure exerted on a urace the rato o orce appled w.r.t. the area o urace Intal F P So But F d P d d dv Hence δ PdV 5

6 Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. FIGURE 3-9 a doe a derental aount o work d a t orce the pton to ove y a derental aount d. Boundary ork,, Fnal, n hen the preure kept contant, Ioarc proce, Intal PdV PV ( V ) Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. Specc Boundary ork, w, FIGURE 3-9 a doe a derental aount o work d a t orce the pton to ove y a derental aount d. Fnal, n hen the preure kept contant, Ioarc proce, Intal ω Pd P ( ), k Or PdV PV P V P P cont P Or ω Pd P P, k P P cont P FIGURE 3-0 The area under the proce curve on a P-V dara repreent the oundary work. 3-3 F Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. d P PdV d Boundary work on a P V raph rea d 0 0 PdV FIGURE 3- The net work done durn a cycle the derence etween the work done y the yte and the work done on the yte. PdV 3-4 ω Pd Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. ork done - Cyclc proce Total work area o nu area o B. Total work haded area Output power,, k Input power, n, k Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. ork done Flow work Enery Traner Ma Conervaton Flow work enery requred to overcoe retance at the Boundary oth whle entern and leavn the yte 3-5 FIGURE 3-48 Scheatc or low work. PV, ω P, k / PV, ω P, k / Ext Conder a lown throuh cylnder o lenth l and area Ma ut e conerved n any proce. n, k y Lenth, l or n k y, For teady low Ext y 0 n 6

7 Enery Traner Enery o Movn Ma Conder a lown throuh cylnder o lenth l and area Let the a low throuh or te Let the a low nterval o Dt, uch a 0 econd wth a velocty Snce volue V Lenth, l volue V low rate Ext or V 3, a V k Flow rate, Enery Traner Enery o Movn Ma Conder a lown throuh cylnder o lenth l and area Let the a low throuh or te Let the a low nterval o Dt, uch a 0 econd wth a velocty Snce volue V l volue V l low rate or 3 V υ r, Ext Lenth, l r a V υ k Flow, rate Copyrht The McGraw -Hll Copane, Inc. Peron requred or reproducton or dplay. Enery Traner Enery o Movn Ma Knetc enery, ke Potental enery, pe r? h ke, pe, 000 k 000 k Internal enery, u u, k Ga Mxture Ideal Gae Equaton o State - P--T ehavour PV RT Hence, can alo wrte PV NR u T FIGURE 3-5 The total enery cont o three part or a nonlown lud and our part or a lown lud. N no o kloole, kol, M olar a n k/kole and R unveral a contant; u R u MR. R u 8.34 /kol kol K K R u Hh denty Low denty 7