Steam EngineSliding valveSteam enters chamber fromleft, leaving from rightboth valves closed, piston moves to the rightSteam enters from right,leaving from leftpiston moves back to the leftSimple steam power plant cycleHeat inWork outCondensing back to iquidform for easy transportationHeat inWork outHeat out to cooling waterWork inby pumpSuperheated steamSaturated waterliquid+vaporCompressed(subcooled)liquidPhase ChangeAbove critical point,there is no cleardistinction betweenliquid and vapor phasesMeltingvaporizationsublimationConstant pressure processpvpTTVConstanttemperaturelinesConstant pressureline(a) P-v diagram: Along the constant temperature line, increasing vapor pressure will lead to higher density (lower specific volume) due to compression. After it reaches the saturation pressure at that temperature, the vapor will condense into liquid while the pressure remains constant until all vapor condense into liquid. (b) T-v diagram: Along the constant pressure line, increasing liquid temperaturewill lead to lower density (higher specific volume) due to thermal expansion.At the saturation temperature, the liquid will vaporize into gaseous form at a constantpressure until all liquid vaporize.pTP-T phase diagramsolidliquidvaporMelting/freezingSubstances that contract on freezingSubstances that expandon freezing ex. Water.Higher pressure makesit more difficult to freeze, thus requiring lower freezing temperature. The reverse is true for substances that contract on freezingCritical pointVaporization/condensationSublimationTriple point: all three phasescoexist in equilibriumCritical point: A limiting state above which there is no clear distinction betweenliquid and vapor
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