MAE 431 ENERGY SYSTEMS I.

Transcription

1 MAE 431 ENERGY SYSTEMS I 1

2 ENERGY SOURCES COAL Deep Mine Strip Mine NATURAL GAS Cnentinal Shale Gas OIL Cnentinal Shale Oil TYPE DISADVANTAGE ADVANTAGE Heat Energ Enirntal Damage Cheap, Abndant 12,000Bt/lb Occpatinal Danger Chemical Heat Energ 950 Bt/ft 3 Chemical Heat Energ 18,000 Bt/lb Chemical Well sealing Water clean p Difficlt in ransprtatin Ver Transprtable Limited Sppl Cheap Abndant Epensie Pliticall Sensitie GEOTHERMAl Heat Energ Limited Sppl N Fel Cst NUCLEAR FISSION Heat Energ Radiactie aste Fel cst Capital Cst FUSION Heat Energ Nt Cmmercial Lng Deelpment (50 r) Fel Cst L Radiatin Unlimited Sppl SOLAR Thermal Heat Energ Large Area Reqired N Fel Cst Bt/ft 2 hr Unaailable Perids BIOFUELS Heat Energ Oil replacement HYDRO Ptential Limited Lcatins N Fel Cst WIND Kinetic Energ Limited Lcatins N Fel Cst > 30 mph reqired Unaailable Perids SOLAR Phtltaic Radiatin Energ Large Area Reqired N Fel Cst Bt/ft 2 hr Unaailable Perids WAVE AND TIDE Kinetic Energ Limited Lcatins N Fel Cst Capital Cst ELECTRICITY? HYDROGEN?

3 ENERGY SYSTEMS ENERGY SOURCE TYPE ENERGY SYSTEMS COAL Deep Mine Strip Mine Heat Energ 12,000Bt/lb Steam Electric Heating Snfel NATURAL GAS Cnentinal Shale Gas OIL Cnentinal Shale Oil Heat Energ Gas Trbine Electric 950 Bt/ft 3 Gas Trbine Mechanical Cmbined Ccle Heating Heat Energ 18,000 Bt/lb Gasline Engine Diesel Engine Heating Aircraft Gas Trbinel GEOTHERMAl Heat Energ Steam Electric NUCLEAR FISSION Heat Energ Steam Electric FUSION Heat Energ Steam Electric SOLAR Thermal Heat Energ Steam Electric Bt/ft 2 hr BIOFUELS Heat Energ Oil Sbstitte HYDRO Ptential Energ Electric WIND Kinetic Energ Electric > 30 mph reqired SOLAR Phtltaic Radiatin Energ Electric Bt/ft 2 hr WAVE AND TIDE Kinetic Energ Electric

4 Gas Per Ccles Bratn Ccle Gas Trbine Aircraft - high elcit jet Transprtatin - mechanical per Statinar per - mechanical per Ott Ccle - spark ignitin engines Diesel engines - trcks, lcmties, statinar per Cmpressin Sstems - Prcess Indstr, Air tls Vapr Per Ccles Rankine Ccle steam and nclear plants Organic Ccle sstems Refrigeratin Ccles Vapr cmpressin - air cnditining, refrigeratin Heat Pmps Reerse Bratn Ccle - air cnditining, crgenics Nn-Reacting Mitres Gas Mitres Pschrmetrics Nn-Reacting Mitres Gas Mitres Pschrmetrics Reacting Mitres Cmbstin 4

5 Crse Smmar REVIEW OF THERMODYNAMICS Chapters 1-6, abt 3 eeks Chapter 1 Cncepts Thermdnamic sstem, prperties, state pint, prcess, ccle, heat and rk. Thermdnamic prblem sling techniqe. Chapter First La First La fr prcesses and ccles Chapter 3 Flid Prperties Real gases - steam, air, refrigerants tables Ideal gases, Eqatins f state First La in Clsed Sstems Chapter 4 Clsed Sstems First La in clsed Sstems Chapter Cntrl Vlmes Mass balance in Open Sstems First La in Open Sstems Chapter 6 Secnd La Statement and Crllaries Heat Engines Reersible engines and refrigeratrs Carnt Ccle Chapter 7 Entrp Secnd La and heat engines The Entrp prpert Isentrpic prcess Entrp change calclatin 5

6 Crse Smmar ENERGY SYSTEM TOPICS Chapters 7-13, abt 11 eeks Chapter 8 Eerg, Aailiabilit Aailabilit in Energ Sstems Eerg Chapter 15 Reacting Mitres Reactin mass balances. Reacting energ balances. Cmbstin Chapter 10 Vapr Per Ccles Rankine (steam per) reheat, sperheat and regeneratin ccles Chapter 9 Gas Per Ccles Bratn (gas trbine) ccle Ott (spark ignitin engine) ccle Diesel ccle Chapter 11 Refrigeratin Ccles Vapr Cmpressin Ccle Heat Pmps Reersed Bratn Ccle Chapter 12 Prpert Relatinships Using eqatins f state Maell Relatins Prpert Ealatin Chapter 13 Mitres Prperties f mitres. Chapter 14 Gas- Vapr Mitres Prperties f air ater apr mitres. Pschrmetrics 6

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8 Q in W = W net tpt cmpressr trbine W Gas Generatr Per Trbine Aer-deriatie Gas Trbine 8

9 Frnas Hall J79-GE-8A Fighter Trbjet Engine First flight 1955, 17,000 bilt, replaced 1960 Cmpressr (right end), Cmbstr (red) Trbine (left end) 9

10 Frnas Hall J79-GE-8A Fighter Trbjet Engine Cmbstr (red) and Trbine Stages 10

11 Gas Trbine Technlgies Thermdnamics - prcess design, T, p and mass fl Aerdnamics - cmpressr and trbine blades Stress Analsis Vibratin Bearing and Lbricatin Sppl Rtrdnamics Manfactring Prcesses Mechanical Design Cntrls and instrmentatin Gas Trbine Engineering Tasks Design Reqirements Deelpment Design Deelpment Testing Manfactre Shp Testing Field Testing Installatin Maintenance Operatin Reamp Energ Sstems are nt all thermdnamics. Thermdnamics is the beginning f Energ Sstem design Prcess Design. This Crse: Thermdnamics f Energ Sstems Prcess Design f Energ Sstems 11

12 Thermdnamics Oerie Thermdnamics Thermdnamics is the std f the relatinship beteen all frms f Energ beginning histricall ith the relatinship beteen Heat and Wrk. Las f Thermdnamics ( fndamental bseratins) Mass Balance (shld be a la) Mass can nt be created r destred and is cnsered. First La (Energ Balance) Heat and rk are eqialent Prpert energ is defined Energ can change frm, can nt be destred, and is cnsered Secnd La Heat can nt be cnerted cmpletel t rk. Prpert entrp defined. Ideal and actal heat engine efficienc. 12

13 Thermdnamics Cncepts Thermdnamic Sstem Prperties State Pint Prcess Ccle Heat Wrk Energ First La - Energ Balance lead the analsis 13

14 WORK MASS HEAT Thermdnamic CONCEPTS Sstem Prperties State Pint Prcess Ccle Cntrl Vlme 3 Tpes f SYSTEMS Clsed Open Unstead 14

15 CLOSED THERMODYNAMIC SYSTEM NON FLOW SYSTEM A mass f material. Heat and Wrk can crss the sstem bndaries. Mass can nt. Heat Eamples: A clsed tank. A pistn clinder. Internal Cmbstin Clinder Wrk CONCEPTS Sstem Prperties State Pint Prcess Ccle 15

16 OPEN THERMODYNAMIC SYSTEM STEADY FLOW SYSTEM A fied regin in space. Mass, heat and rk can crss the sstem bndaries. Eamples: CONCEPTS Sstem Prperties State Pint Prcess Ccle trbine, cmpressrs,bilers, heat echangers Mass in Mass t Heat Wrk 16

17 UNSTEADY FLOW THERMODYNAMIC SYSTEM A ariable regin in space. Mass, heat and rk can crss the sstem bndaries CONCEPTS Sstem Prperties State Pint Prcess Ccle Eamples: A filling tank. An empting tank Pistn-Clinder Filling Heat Mass Wrk 17

18 18 Thermdnamic Prperties Temperatre Pressre Vlme Internal Energ Enthalp Entrp mass V,ft m,lbm/ft kg/m /lb ft m /kg, Ambient pressre Gage pressre Abslte pressre lb/in bar, atmspheres, kpa, F R C K 32. C 1.8 F R K, abslte, C, F, = = = = = Vlme V Densit ρ SpecificVlme Pressre p Temperatre CONCEPTS Sstem Prperties State Pint Prcess Ccle

19 Thermdnamic Prperties SpecificInternalEnerg kj/kg, BTU/lb d = c c dt specifc heat at cnstant lme, 3 kg/jg, m /kg U InternalEnerg kj, BTU C, BTU/lbm F CONCEPTS Sstem Prperties State Pint Prcess Ccle h Specific Enthalp kj/kg, BTU/lbm h = p c p dh = c dt specific heat at cnstant pressre, H Enthalp kj, BTU H = m h s S Specific Entrp kj/ p S = m s Entrp kj/kg K C, kj/kg C, BTU/lbm F BTU/lbm F 19

20 THERMODYNAMIC STATE POINT Prperties are measred. Eqatins and mdels are fitted t the data reslting in : Tables f Prpert Vales Eqatins f State Cmpter prpert mdles T prperties define the state pint f a single phase flid. rdinate prpert (T,p,,,h,s) CONCEPTS Sstem Prperties State Pint Prcess Ccle One prpert defines the state pint f a mltiphase flid. absisa prpert 20

21 THERMODYNAMIC PROCESS A thermdnamic prcess is an interactin beteen a thermdnamic sstem and its srrndings hich reslts in a change in the state pint f the sstem Reersible Prcess A prcess is reersible if the state pints f all affected thermdnamic sstems, inclding the eternal sstem r srrndings, are retrned t their riginal state pint ales. Eamples: - mement f a frictinless pendlm - transfer f rk t ptential energ itht lss - mement f a frictinless spring CONCEPTS Sstem Prperties State Pint Prcess Ccle Irreersible Prcess A prcess hich can nt be reersed bringing all the affected thermdnamic prperties back t their riginal ales is irreersible. Eamples: - appling brakes t a ming heel - miing ht and cld ater - transfer f heat thrgh a finite temperatre difference Heat Wrk 21

22 Q ccle net W ccle net THERMODYNAMIC CYCLE A thermdnamic sstem nderges a ccle hen the sstem is sbjected t a series f prcesses and all f the state pint prperties f the sstem are retrned t their initial ales. = = ccle ccle Q W prcess prcess p CONCEPTS Sstem Prperties State Pint Prcess Ccle First δq = La δw initial pint is an ineact differential, a deriiatie that is path dependent. 22

23 Thermdnamic Prblem Sling Techniqe 1. Prblem Statement Carbn diide is cntained in a clinder ith a pistn. The carbn diide is cmpressed ith heat remal frm T1,p1 t T2,p2. The gas is then heated frm T2, p2 t T3, p3 at cnstant lme and then epanded itht heat transfer t the riginal state pint. 2. Schematic 3. Select Thermdnamic Sstem pen - clsed - cntrl lme a clsed thermdnamic sstem cmpsed t the mass f carbn diide in the clinder CO 2 W Q srrndings p p 4. Prpert Diagram state pints - prcesses - ccle Q T2,p2 T3,p3 T1,p1 5. Prpert Determinatin T2,p2 W Q T p h s W Las f Thermdnamics Q=? W=? E=? material fls=? CONCEPTS Sstem Prperties State Pint Prcess Ccle 23

24 24 τ τ τ τ τ τ = ρ ρ τ τ τ ρ ρ ρ = ρ ρ τ τ τ ρ ρ ρ = ρ ρ τ τ τ ρ ρ ρ = ρ = T p T q q q T T T t T c ENERGY f p t f p t f p t directins,, MOMENTUM 0 t CONTINUITY p EQUATION SUMMARY - 3D, iscs, ariable densit, nstead