A simplified Flow Chart for Thermal ScienceSlide 2Slide 3Slide 4Slide 5Slide 6A simplified Flow Chart for Thermal ScienceI n t e r - r e l a t i o n s h i p C h a r t b e t w e e n d i s c i p l i n e s i n t h e r m a l s c i e n c eE n e r g y1 s t L a wE n t o p y2 n d L a wT h e r m o d y n a m i c sR a d i a t i o nS t e f a n - B o l t z m a n n L a wC o n d u c t i o nF o u r i e r ' s L a wC o n v e c t i o nN e w t o n ' s L a wH e a t T r a n s f e rM a s sC o n s e r v a t i o nM o m e n t u mC o n s e r v a t i o nE n e r g yC o n s e r v a t i o nF l u i d M e c h a n i c sT h e r m a l S c i e n c edQdtKAdTdxdQdthA T T ( )U Q W revTqdsEnergy ConservationIrreversibilityAvailabilityQ:heatW: workdmdt0dPudu gdz 0Euler’s Eqn.Navier Stoke’s Eqn.P ugz C 22Bernoulli’s EqnMech. Energy Cons.Note: this is only a brief overview of thermal science. Principles governing these physical phenomena have been greatly simplified in order to illustrate the inter-connectivity between disciplines.dQdtATb4A complete thermal system: Solar Power Plant• Heat received by collector due to solar irradiation.• Heat transfer to working fluid (oil or molten salt) by convection and conduction.• High-temperature fluid heats water into steam via heat exchanger.• Steam flows through typical thermodynamic cycle(s) (ex. Rankine cycle) to generate electricity• Cycle consists of a series of processes (ex. isentropic expansion in turbine, isentropic compression in pump, heat loss to condenser.)• Work and energy balance will be calculated using 1st law of thermodynamics and thermal properties of working fluids.• Fluid principles be used to analyze flow work in pump and turbine, pressure loss in piping system, convection in solar collectors.• Thermal efficiency and availability calculated using 2nd law of thermodynamicsThermal Systems:Solar Power PlantWind Energy Power PlantJet EngineInternal Combustion EngineRefrigeration & Heating EquipmentThermal Bubble Inkjet PrinterElectronic Cooling PackageEnergy Exchange Solar Irradiation Wind Energy Fossil Fuels (Chemical Energy) Electric Energy Thermal EnergyWork Input and Output Generate Electrical Energy Transform into Mechanical Energy Electric Energy Input Inkjet PrintingWasteful Byproducts: Thermal Pollution Air/Water Pollution Toxic ContaminationQ: Heat TransferW: WorkU: Internal Energy ChangeRelevant Issues:• Understand fundamentals of thermal science• Improve efficiency of existing thermal system• Reduce environmental pollutionGreenhouse effect, ozone depletion• Devise innovative thermal technology •Interdisciplinary knowledge is requiredMethodology used:• System definition and modeling• Thermal properties identification• Apply engineering principlesMass, momentum, energy conservationFirst and Second laws of ThermodynamicsHeat transfer modesEnergy Balance: Process U = Q – W, Cycle U = 0, Qcycle=WcycleThermal Efficiency: Power cycle = Wout/QinRefrigeration cycle = Qin/WcycleSolar CollectorCondenserPumpHeat ExchangeSolar IrradiationHigh-tempfluidLow-tempfluidHigh-tempsteamLow-temp,pressurizedwaterShaft work outputMixed water & vaporCooling water TurbineHeat Transfer: Absorption of solar radiant energy Convection and conduction inside pipes and heat exchanger Evaporation and condensationFluid Mechanics: Pressure loss in pipes due to friction and flow separation Flow work in pump and turbine CavitationThermodynamics: Thermodynamic property and state System and control volume, process and cycle Phase change
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