Video 1: Rankine Cycle Overview Network cycle: waste-wout. will hittipt= I din-But Thermal Efficiency: y Waycle/m = ①in/in 1 = - (Port/in Din/r in Vikco2:Rankine Cycle components enthalpy decrease enthalpy decrease enthalpy increase enthalpy increase Video 3:Rankine Cycle Ideal Processes I A. ⑤I V T Tc = ↳ % ② P Pc = P Pb · = ⑤ ⑭ - T Tc Wine = · B - ⑪ Wort ↳ furt ② P Pc = Video 4: Fixing State 4 * not necessary Videos:Ideal As the As the Cycle Performance averageit tintin Pout we are limited by ambient temperature Tin < * AT is in not boiler, Nth for but is good performance x a at outlet of tubine which Video 6: Rankine internal * -> Cycle within the Principle Irreversibilities system (we seek to minimize) Isentropic Processes * are adiabatic Breversible Internal Irreversibilities · pump & (constant entropy)* Bankine Cycle: turbine -> friction moving parts (mechanical expansion in in that we dont restrain completely =He fluid friction), ideal = actual External Irreversibilities · beattrusten- system - condensers fluid ↳ to Gate: smondings I to system surrounding thid of boiler-Temp ofcombustion products Temp working *there is - Rankine in a finite there temperature difference mustbe finite Bronking third spontaneous nuclear reaction trap diff between cooling Video:Rankine Gale Superbeat change boil A steam to generator A ↳ same functionality * we a can use a higher quality boiler and superbeat higher at the outlet ofturbine order to in a -isentropin .... -steam 1 generator 4 3 2 ersen E 2s 4s and 2 lie on same Pressureline and lie on Same Pressure line 4 3 actual produce Video 8:Rankiee * Assume Bring Cycle Rebeat turbine inlet back fluid stage through is superheated steam genenter chamber with combustion through portion of expansion a in gases E to reheat it after its been turbine pressure condenser in 3 I 2 p P, ↳ - S ③ ~ 88 I p P2 Ps = ↳ 6 S = high pressure ~ reheat 3 . ⑧ p Pc = · A turbine 1 &iorpasmetbin = T, ⑧ m process 4th Wycle/m = Qin/m 0 4th Wupt in with = - this is atire because reg its & m bQ, in * y is I z Qs in improved because the work outputproduced by the 2 turbines than the aditional Heat transfer thatcomes in during reheat is more Video:Bankine Cycle Supercritical p ~ goes from supercritical liquid supercritical vapor to Pcrit = Video 10:Rankine Gale Regenerative Open Feedwater Heater (1 - x) (1) Y Open Feedwater Heater into -> increases Temp of feedwater boiler) by mixingwith High Temp Steam ofTurbine (water thatgoes * we take Pump ↳ a portion of flow from mix it with t-bine middle of low temp flow coming from R 6 since higher than 16 without feedwater heaten, is -x3 ( (1 y) - Theseindicate the fraction Qin at steam generator ofthe mass is flow thatis alongthatparticular path reduced flowing Ibleed y fraction of mass = flow extracted bleed flow = (ty) fraction ofremainder = through *mpsort ant - -> all - mass flow condenser pump to note x paths my only mass mass flow one flow rate Ex. m3 my=is = i, m>=m = way for fluid to flow will have constant exiting MPT and going * Pressurein OFM must have same pressure => all inputs Boukuts mixing together if my diferectflow Pressure were that direction in world go since theyre all need we a pump · M · for this (I-y) reaches states it mixes in when I OFH with - 7 Tzt, Is' until -2 6 if * we flow to ↳ back to condenser some need Instatewe needto P6*P, 3 connected stateto the OFH go · ⑧ · -> Pa=Ps=P6 reaching T6 58 Pump -> fluid at state B: We then so we increase P6beause addanother Higher Pressure at state I would Not What We Want so flow is baked and goes in direction want we pump cause the State w/o Sa OF is process Video Calculations II:DEW To calculate y: Mass Rate Balance & I -6 ....... i OFM( Energy Rate Balance Assumption: - S Adabatic -No menk i done on being ev . Mass Balance: 0 m2 + = * = - m2 mg r, = + - Energy Balance: O = mehz+mghs -m,h6 = hi, mis-n6 is m3 0 y2 I my M, = around of O mehz+mghs -m,h6 = I m, 0 yhz = 0 + ((-y)h) hx - yhz hs = + -hsy - bb h6-hs yhz -yh5 = ho-bs y= b6-hs he -hs The * ra 3 bleed energy ha-hs y = fraction rate balances for work are normalized by the He (ii) highest flow mass Work: Turbines: MPI - S ...... I wou b ........ WE=m,(h, -he) - it,p=ms(ha-by) > WE WE, MP WE, LP = hiz: mi + hi-hat (1-y)ha-hy neuseing becausey has already left e Pumps : " up,=ms(huh t ip, m,(h6 -ha) 6 q z = D Wp, Up z lip, hip.2 = it Wp m,(hy -hy) m3/hn hs) = + - p ha-b (r-y) (by-h) + = Heat Transfers: Steam Generator! ①in mi(h, -ha) = Gain ... " .. . Die= - : - t hi-ha 7 y Wcycle/mi ain/m, = 1 (h, hz) ( y)(ha hz) (h6 x (1 y)(hn b5) - + - - + = h, -by - + - - Video Regenerative 12: Cycle Closed Feedwater ~Massflowrate reduces Din 1 - Y (1) wit 2 3 I -Y [Y) E steam generator S Condenser Port [I] (1) Pump I 4 S 6 heater Trap 7 doesnt mix S between CFM &OFM with flow 5-6 8(Y) X LY) Difference * ↑ Up closed feedwater A is that in CFM the flow from 2-L A steam trap -> operates these I we as throttle, lowers pressure, no power input, ↳ constant enthelpy pressures don't haveto don't have to worry be equal since about direction it is not no moving parts mixing Ps P6 P, = = In F y8 8) S Qin to I advantage O from s-x6 of energy is reduced because from 2.77 me are taking Video Calculations 13:CFM y i2 = mi; To calculate W - ! I b 31 y: Mass Rate Balance & ·------ ↓ - Energy Rate Balance around Mass Balance ↳ I S ↓I .......... mz in m6 Ms i, my = = = = of Energy Rate Balance mahy-m>hytinsts-myho 8 = 8 = mahy-m>hytinsts-myho i, 0 yhz -yh> = hs + - h6 hy-bs yhz-yh> = y ho-hs ha-bs I ↳2 hy ha-hy Y = - Work: HPT · sier it,Mp m, (h, = -ha) T - I swe 3 Lit, (p ms(h2 -hy) = its is because * at LPT inlet the bleed flow has been extracted already ip=in (hn-hs) si ->Y Heat Transfer: steam gen ⑨in m,(h,-h6) I Qin = - -> ↑ 6 y waycle/in = ①in/in, h y itMP,lt,P+ in, = mi, Din/m, 2 (h, hz) (( y)(ha h3) + = - - - +hy-hs hi-h6 Heat Transfer Out Condenser: ↓ Gout-mzhz mehe-myhy + Qurt -> nb48 ⑳ut=(y) hy+ yhs h Video 14: Multiple Feedwater Heaters Videos:Multiple Feedwater Heater Gakulations (1 y' y") - y - y" lisentropic) HP & * EWH every * reheat is multiple CEN FWH should have atleast 1 OFM section between MT $ LPT * y' By"are defined y': i in ms = y in Closed FWM: After "F--; " : terms of in, Mrs. doingEB: =hi, his Y No ha-hiz ↓ ... - - - - 12 Open FWH: S ........ " V After I ↳ I i. - is - ! 8 " = doing EB: y (1-y)h8+ y'his-hp ho-hs it, itz weare Wt3 Dinn I Why Qin3th state l T, 480° = Pi = 8 MPa hi 3i state 2 Se S, = Pa 2 MPa = 3h State 3 5 P3 = se 0.7 = MPa 3hg= State 4 Tn=440° Py P3 = 3 state s 55 S4 = Ps 0.3 MPa = ihs state 6 346= 56 Ss = P=0.008MB state 7 3 = e state 8 P8 P5 0.3MPa h8 3 = = 58 57 = = state o Pg Ps 0.3 MPa = = Xy 0 = 3 hq Sp = = State 10: 3 Sio Sq = Pio Pr Pi 8MP = = a = hio= state II Pi D1o=P, = 8MPa = T1 205 = State ] 12 Piz =P2 MPa 2 = h e hin State B his hie : Pis PS Py 98 = = = it 0.344.3 his = he = its=/1-y) wizz (( = - hasa y)(hy hs) - in, ity=(ky'-y")h5-ho in, up,:(ly'-y) ha-ho in, * for and upo in, pump allmass flow rates mixed are together * ha-hio = ain=h,-h,+(ry) hm-h3 i, Wade i, Wtz +WEn+ tz lizy + + p, ripe e are thesevalues negative A Wade/mi = L Din/i in Wcycle = > IOOMW Wayce/m, Wtz +W2+ity hity + + p, ripe Video Choosing Working Fluid 16: a Criteria: - - inexpensive abundant -nontoxic -chemically stable - chemical reactions in flow -chemical reactions - relatively we -large damage to components of irreversibility strong cause are a source non corrosive dont wortham in components enthalpy of vaporization we want it giveoff alotof energy during expansion - to in turbine large specific volume change during vaporization - Pr. Wort 4 ne water hits all these spots ↳ cuban hydrogen band Topping Ist Cycle Boiler-takes high temp source to turbine HeatTransfer of - topping i S · I fluid to bottoming flid Toppingcycle ↓ Qut ↓ . a , ↓ ⑤ -> Bottoming cycle b C steam atinlet of for ↳ Qin Qin - generate buttoning cycle Water 3 stre S * improved of because you have high heat addition average temp to environment have reduced the but best of you average temp y is a rejection Video 17: Cogeneration Cycles: Video H: Vapor Compression Refrigeration 3 3 energy Refrigeration cycle-transfer hot B from system into reservoir into system outofsystem from cold reservoir reservoir (superbeated vapor phase) (constath)(4s) cold e into system Trh-> I which 1 · 3. Tr,h- v · Tr,c-> S into > TM into hot reservoir Rejection) Tn -> Terop of Ty ----------------- Tr,h goes (Heat 2 Tc.------------- Tr, - of high temp Refrigerant Not Reservo: Temp of Refigment in energy is working graph on TS of Meat Transfered Diagram for remusible processes slid of tells us amount ↳ In Counter Clockwise Meaning its -> -> a net out Waste,net,out=Qayele, - Transfer (Refrigeration Cycle) thatMeat in Wagels,ort=-Quale, in Wayce, Qcycle, out in: location transfered from cold reservoir Tc<Tr,c Area inside cold is Negative resing Video HI: Cycle Components Vapor Compression F T3 TH 1 ~ · - - M 3 S that Exchange theen I exchang hot reservoir Heut I a 3 - X 4 Rout to M L - fiz Condenser of win - V xX ↳ I - I > & Din Heat ↑ Exchange that exchang Qin from cold reservoir into es system (compressa) nic=m/h, -h2) Diort=m/ha-ha) Typically, X3 Gendersel 0 = hy hy (expansion value) = Ideally, X, 1.0 = * For a practical reasons avoid little to we droplets superheat in compressor 3 a ain=m/h, -hu) For instance: 1Th 20°C, = Tn 25 = T3 (25 20) = + Greficient of Performance: B Qin hihy Iwyclel/hi-hal = = (evaporator) The So Explaining bullet first point: point of TySTc process /Temp of w -frdp = 3-4 cold is just a blockage to reduce reservoir) compression is butif had you phase value is done w/ a so mixture vapor turbine at pressure so wis expansion, high so it would be the would be too low tempt expanding liquid a or a 2 Video 42: p-h Fiagrams Video 43:Cascade Refrigeration Cycles Refrigerants Video 44: selection seal easier to Video 4S:Heat Pump Cycles ~ Heattransfer the reserve not Video 46:Gas Refrigeration Gale * 400-sooK -300K Video S3: Ideal GasMixtures to caracterize state A *In mixtures we need extra info Ways to characterize mixture: moles, mass,fructions, average molecular weight n #moles = m ma55 = in component component of M molarmass/Mobeclan neight = Ratios are used more commonly n =#ofmoles n total = component of given of molesin mixture Bitmassofrepareinte the Yi&mfi · 2waysto are intensive properties -> dont depends size on of system calculate: M Yi molar mass mixture average componenti mole fraction of = = Mi=Mola Mass I msi=mass component: of fraction of componenti Mi=Molar mass component: f o Video p-v-T SH: How to relate Mixtures Pressure, Volume Itemp to each other mixtures of ideal for gases: unstert R universal gas (5/molK) (Btw/IbmolR = =8.314 = unigas constant average mixture mole mass * We can aracterize behavior of each component Pi=pantial pressure comparenti of p:total pressure in terms ofideal gas law w Partial Pressure will have: component same total extensive volume V each -> · same · We also relate can Di temperature I P of a T partial ni pressure Di V - is a property particular component to mole functions: Yi = n nRT V · Di p Yi = only * defined in terms ofmole fraction defined not * ↳ Because So I in R terms ofmass fractions is different for each would not cancel in equation * componentIR for overall mixture i Video SS:Mixture Properties M total = To put it emeralize this component: in terms of mass or of components molar in mixture specific propertiesof each Video Psychrometric Principles 56: ↳n Yaz motefraction total either solid or lig of a Pressure D: · D my air Air-> particular agreed upon ideal specification for treat that involves pure component thatwe can Nitrogen, Oxygen Both water · as some a and alittlebit of - - same Some volume Temp or composition of mixture of Argen will fill the entire volume rapar dry system temperature they will both: $ the of the container at the Other ways to characterize mole fractions than justby mole functions - partialpressure Mu 18 = Ma of air 0.622 = 28.2 ~ specified in weather 3 reports tempPene keep Icons but add Me mass water of vapor more into mix [HumidityRatio 4, pantial pressure of water By T · - Pu ..-- - - - vapor 4) Video S7:Moist remember * Air -> Properties moist at=mix ofdry air water vapor were both are treated ideal as gases calculate thetotal We ↳ internal of the moist can energy air mixture ji:total intenergy mixture totalintenergy of energy (an approximation) Las W ⑤ · ofideal gasdepends gasdepends total int a vapor m = approximation) internal energy ofan ideal dependson gas mideal of on enthalpy entropy water of the sun of air ma b (approximation) · as of on Temp (u) Temp (h) Temp, Pressure (st ↳ partial pressure of component particular P = +,P Video 58:Dew Point So Temperature far behave treated rap dry to when theis a condensed get exchange well water mass with the Dry & independent ideal phase of water(hig or but gases solid) which vapor phase Hir WaterVapor some moleculesof liquidwill I some Mee liquid air as become we par moleculesof repor will become liguid lig: satliquid sat vapor: vapor 3 the rol e at - which is this occurs balanced now is able to start: ① Dry Air hatVup Tsat=Dem Point Temp water of T Pr= YvP P Reduce & - rap I I Isat it . ③. ·2 I ............ Du Prz · Dry Air ⑬ WaterVap - - W 2-33 · · occurs Der Point Temp on is sat line related to the initial High ValuesofDPT Feels = to decrease &a quite as more partial pressure braid outside because much for water to start higher partial pressure of water water of vapor vapor temp the doesnot have condensing:More water rep in air Video S4: Adiabatic Saturation · · How to measure I for partial pressure Temperature calculate humidity ratio use that to ofwater vapor in a to characterize moist air mixtures 2 ways get moist mixture humidity ratio, partial pressure - Temp of adiabatic saturation Tas: ...... T - - Pi WI " .... 19) -......... Tz Ta5 = 2 Assumption: Pa PI = %2 100% = w - ? = liquid bi Open System - water - - Mass Rate Balance: mas= maz:ba hi, + mw hve = nic ma Remember * W2 nive = ina in a W, mv, = niw in a We -W, = ma a * Adiabatic No Work No PE no KE value Energy Rate Balance O ma,hai+mvhr, nwho-mashazivahva = t Dividing everything by ina: 0 ha w,hr, = + Pr= * + (wa-wi)hw-baz-wahve Py(tas) W2 0.022 = -> sat mix at outlet Pg (Tas) 4-Py(Tas] Wi haz-hast = we [hva-hm] Gr,-hw A hu h5 (Ta5] = hav ha (T1) haz ha(Tas] = hr, hr(+1) = huz=hr(Tas) Drybulb - Wet Bulls - Tab:TI Tub:Tas ......... wrap tick around thebulb sulk wick in flow Ma air over wick * Video 60: Psychrometric Charts Another way to relate propertiesofmoistair mixtures (notjustusing equations) · Dry Bulb Temperature temperature - thatdoes not have · wehumidity ratio partial pressure a metmick -> Because of the air that on we measure with a it total Pressure is constant, wis constant -> directly related of water -> lines thermometer of constantrelative Note:4 * = 100% is humidity (b) sat mix * to the -> lines of constantmixture enthalpy line used to find metbulb -> temperature lines of volume per unit mass of dry air V ma P latm = Lets say 6 401 = Tb 8 30° = starting - condition . · 8 We can use any 2 properties so long as their lines intersect: W&b -> -> -> I B Tab Tub I -> I -> etc Tdb & Tub Tdb 30C = · b 40% = · ·W 0.011 = E · for dew point E water E · for a constant composition process thup (follow sloped straight lines) (Remember until reach the vapor into mixture you Not the * Turb for 8 occurs Tdp= 15.5 for met bulb A temp (Remember it = 20 specific enthalpy (follow same H ma =Sin For volume (strepest diagmal) line as adding you saturation conditions) are steepest line Tub butextendity Given particular al direction Ex. Air water on the type of conditioning process, air psychrometric chart that process Process Condi t i o ni n g world that process r where Im go determine we can on the cooling following the should ar direction: what go. by evaporation (by adding Tb W4 humidification by doing injecting would be the If I'm then the direction steam following: Tab 7 Y w If Im doing dehumidification by condensation from coding TdbN wi L If I'm doing changingtemp V a i desiccation process (Silica packets) -> absorb water who Video 61:Air Conditioning Processes Wm = There are 3 air conditioning processes: Ma 2 ways: & Evaporating ③ Mix in some liquid water steam, some Temp of sup steam Temp of causes we, Tab ↓ superbected vapor moist mixture Tdb* w4 causes butbecause 2 ways: desiccation -> · other chemical · condensation -> we need a point the wath from absorbing vapor such -> as reducing silica to reduce w cooling coil to reduce mixture the some w temp ofmoistair environment it at be cold so if An is for occupants enough moist be added mixture below its der ejected to in that space where m/lower heating section might constant humidity process heating coil to 4Tdb happening a * into a also redrew the db mig air it into by removingwatervapor from mixture I turning liquid reduces but it -> the moist air mix w is sent to in a Similar to humidification works well in dry climates process butthe purpose is to get some Temp reduction -> is constructed System to have a wick Process to go So mater sort ofstructure that can hold on to water, liquid water out ofwick evaporatingliquid certain down because satuated with that -> or some I then me flow the of we require Process will tTdb energy &Pw air over that and into moist air input to liquid wate mix temp causes evaporate that water Video 62: Analyzing AC Processes H20 Adding -> wa wi - Assumptions: Steady State - may maz: ma = inv, tniw=iva min We-WI = nic 0 Dc -Wa +ha,+whr, = ma inc Removing Hasi +(wa-m)hw-haz-wahre w, swe man=in a = a inv, mint inve = inw W,-W2 = in a O Qu_Wer+ hart wihr, -(w-wahw-haz-wahre : ma ina Constant composition Case Wi W1 = hia,=mas:man mr=rive 0 ger-wartha, -has) w(hn eit = + - One inlet, one outlet Video 63: Cooling Towers Natural Draft · to Towers-> rely Cooling drive the flow into the bottom of and then out the on top where you typically differences coolingtower see a up in past billowing steam density the ofair following water · Freed draft-> small Were * uses droplets evaporate a drive the flow far to better than droplets big to cool down this water inlet trying &remove more energy so thatwe can send it back to the rankine the water inlet into some of Evaporating -> from outside of cooling tower atmospheric water droplets will -> evaporate into atmospheric droplets warm makeup air mater to make sure in atmospheric air somemoist comes in some -> condenser out of Rankine Cycle -> air cycle of of return water:in & flows -> up Reduces incoming warm through the temp both of water water falling droplet air the water