5Exergy5.1 IntroductionQuantityEvaluationof heatQualityExergy and AnergyFull convertible energy:mechanicalPartial convertible energy:heatUnconvertible energy: environmental
5 Exergy Exergy and Anergy Evaluation of heat Quantity Quality 5.1 Introduction Full convertible energy: mechanical Partial convertible energy: heat Unconvertible energy: environmental
Exergy: useful work potential; available energy;The maximum useful work a system can deliveredfrom a specified state to the state of its environmentin theoryAnergy: unavailable energy, unconvertible energyConditionsfordefinitionofexergywork = f(initial state, path, final state)(1)basedonenvironment;exergyofenvironmentalenergyiszero(2)reversibleprocess(3) thereis nootherheatresourceintheprocess.e=e.+aE= E, +A
（1）based on environment; exergy of environmental energy is zero （2）reversible process （3）there is no other heat resource in the process. Exergy: useful work potential; available energy; The maximum useful work a system can delivered from a specified state to the state of its environment in theory. Anergy: unavailable energy, unconvertible energy E = Ex + An x an e = e + Conditions for definition of exergy work (initial state, path, final state) = f
5.2 Calculation of exergyTypeunbalanceChemicalChemical potentialPhysicalTemperature and pressureKineticVelocityPositionPositionConcentrationDistribution
5.2 Calculation of exergy Kinetic Distribution Chemical potential Temperature and pressure Velocity Position Concentration unbalance Position Physical Chemical Type
UnbalanceSourceElectricityvoltageWaterlevelHydraulicWindPneumaticpressureDifference betweenWaveinterior and surface
Source Electricity Hydraulic Pneumatic Wave voltage Water level Wind pressure Difference between interior and surface Unbalance
5.2.1WorkresourceElectricity, mechanical energy, pneumatic energy,hydraulic energy, can be converted to workentirely.Exergy of work resource = its total energy12E-mcxk2E, = mg△Zxp
5.2.1 Work resource Electricity, mechanical energy, pneumatic energy, hydraulic energy, can be converted to work entirely. Exergy of work resource = its total energy 1 2 2 xk xp E mc E mg Z = = • • •