2420071∗EnergySavingAnalysisandControlofFrequencyConversionVariableWaterFlowSystemWuDeshengYangChangzhiSchoolofCivilEngineeringHunanUniversity410082AbstractDiscussestheenergysavingprincipleoffrequencyconversionchilledwatersystem,analyzesfromboththepipelinesandpumpstofindthattheenergysavingfailurereasoninactualengineeringistheconstantpressuredifferencecontrolmethod.Throughasimplifiedchilledwatersystem,comparesthepumpenergysavingunderconstantpressuredifferencecontrolmethodandvariablepressuredifferencecontrolmethod.Itcouldbeconcludedthatundervariablepressuredifferencecontrolmethod,thefrequencyconversionsystemcanreachthemaximumenergysavingefficiency.KeywordsFrequencyconversionenergysavingconstantpressuredifferencevariablepressuredifferencecontrolmethodminimumpressuredifferencecontrol∗20%1[1]70%90%051015020406080100COP60(1)/nfsP=−fsP[2]1100QnQn=(1)200712522111000HnQHnQ⎛⎞⎛⎞==⎜⎟⎜⎟⎝⎠⎝⎠(2)33111000NnQNnQ⎛⎞⎛⎞==⎜⎟⎜⎟⎝⎠⎝⎠(3)QHNn011nq1/q0%1009080706050N1/N010072.951.234.321.612.5[3]3.12o0n0Q1Q1n2n221nnP∆'HPP=∆+∆'P∆NgQHρ=ρg[3]3.2[4]30H0H[5]2620071[6][7]0H412380CABDPkPa∆=50DFHCEGPPkPa∆=∆=70HMGHNGPPkPa∆=∆=020/QLs=10/HMGHNGQQLs==0250CABDDFHCEGGHHPPPPkPa=∆+∆+∆+∆=0004.9NgQHKWρ==4.170%DFECCABD20'('/)39.2CABDCABDPPQQkPa∆=∆=1''209.2CABDDFHCEGGHHPPPPkPa=∆+∆+∆+∆=11'''2.87NgQHKWρ==41.4%'Q22200''('/)122.5HsQHQQkPa===22'''1.68NgQHKWρ==65.7%520071274.2M70%N50%20''(''/)28.8CABDCABDPPQQkPa∆=∆=1''''198.8CABDDFHCEGGHHPPPPkPa=∆+∆+∆+∆=11''''''2.34NgQHKWρ==52.2%HMG2''(''/)34.3HMGHMGHMGHMGPPQQkPa∆=∆=20''(''/)28.8CABDCABDPPQQkPa∆=∆=20''''(''/)18DFHCEGDFHPPPQQkPa∆=∆=∆=2''''''''''99.1CABDDFHCEGGHHPPPPkPa=∆+∆+∆+∆=22''''''1.17NgQHKWρ==76.1%64.3[8]5.15.21.2.5.35.4[1]..20053538385[2]...1994316-318[3]..REFRIGERATION.20052448083[4]...20022323536[5]...20013165154[6]...2003[7]..20043446569..