-Thermodynamics-I：热力学的我-PPT课件.ppt

1、Thermodynamics IIo Contact informationo Educate.spsu.eduo SPSU e-mailo“tt”o Syllabuso Power Pointo Class ScheduleThermodynamics IIo Outcomeso Creditso Text:M&S 6th or 7th Edition Thermodynamics IIo Learn Ao A basis for learning BRead textExamplesHomeworkQuestionsPracticeThermodynamics IIo Principles

2、 working equations applicationsThermo I:lots of principles&some working equationsThermo II:some working equations&lots of applicationsThermodynamics IIo No cookbooko Orderly/logical approachRead carefullyDescribe systemSketchAssumptionsPrinciples&working equationsSolveReasonable Thermodynamics IIo R

3、ead Type of system Type of working fluid Type of processThermodynamics IIo Assumptions reasonable Steady state Ideal gas Incompressible liquid KE&PE often negligibleSolve Equationo Include unitso Consistent unit systemo Significant digits Thermodynamics IIo Reasonable Make sense?Sign Units Magnitude

4、 Thermodynamics IIo“Heat strength”o Energy transformationsTransportationComfortManufacturingEnergy usage o Effective thermodynamics understandingo Costso Pollutiono Resource conservationThermodynamics IIo Energy usage 10+%income24%Nuclear Powero SPSU:Nuclear Power Generation&Training sessions.Thermo

5、dynamics Basicso Systems Closed Openo ProcessesIsothermalIsobaricIsometricAdiabatic IsentropicPolytropic Thermodynamics Basicso Working fluid:changes phase processes Steam R134a R22 NH3 Propane Working Fluid phase changeo Property tableso State diagram:pressure&volume Compressed liquid Saturated liq

6、uid Vapor dome quality Saturated vapor Superheated vaporWorking Fluid phase changeo Properties:P,T,v,u,h,sWorking fluido No phase change:ideal gaso Ideal gas lawo Caloric equations for u&h:constant specific heatso Variable specific heats:table for air as ideal gasThermodynamic basicso State defined

7、by propertieso Process described by change of stateFirst Law of Thermodynamicso Conservation of mass&energyo Closed system:Heat:direction&magnitude Work:direction&magnitude Kinetic energy:property Potential energy:property Internal energy:propertyFirst Law of Thermodynamicso Open system:control volu

8、meo Additional:flow energy*Internal energy u for CLOSED SYSTEM*enthalpy:h=u+pv for OPEN SYSTEMCycles o Two or more processes in series which return working fluid to its initial stateo Heat engineo Reversed cycleHeat engineo Thermal efficiencyReversed cycleo Coefficient of performanceReversed cycleo COP cooling():refrigeration&air conditioningo COP heating():heat pumpIdeal cycleo Carnot:ideal cycles with no wasted energy.o Ideal COP Cooling Heating Assignment o 3.129&3.130o 4.43&4.45QUESTIONS Examples o 8.2o 8.17o 8.29