PUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM LIFE OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLECYCLETammy GreenlawTammy GreenlawChris CaballeroChris CaballeroAaron RaphelAaron RaphelMinja PenttilaMinja PenttilaCliff SmithCliff SmithTEAM 3PUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLELIFE CYCLEPresentation OutlinePresentation OutlineBackground and Engineering Considerations (Cliff)Background and Engineering Considerations (Cliff)Optimization Model (Chris)Optimization Model (Chris)Results and Conclusions (Tammy)Results and Conclusions (Tammy)PUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLELIFE CYCLE““Motors use threeMotors use three--fifths of the worldfifths of the world’’s electricity. s electricity. Pumping systems use at least a fifth of their Pumping systems use at least a fifth of their total output. In industrial pumping, most of the total output. In industrial pumping, most of the motors energy is actually spent in fighting motors energy is actually spent in fighting against friction.against friction.””FROM PAUL HAWKEN, AMORY LOVINS, AND L. HUNTER LOVINS. FROM PAUL HAWKEN, AMORY LOVINS, AND L. HUNTER LOVINS. NATURAL NATURAL CAPITALISM: CREATING THE NEXT INDUSTRIAL REVOLUTIONCAPITALISM: CREATING THE NEXT INDUSTRIAL REVOLUTION. BOSTON, MA: . BOSTON, MA: LITTLE, BROWN, AND CO., 1999.LITTLE, BROWN, AND CO., 1999.Definition of Pump SystemDefinition of Pump System(pump, pipe, valves, fittings)(pump, pipe, valves, fittings)PUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLELIFE CYCLEOptimize system costs given design life cycle. Consider operating costs (pumping energy) vs. capital costs to install pipe AND capital costs to install pump.Consider operating costs (pumping energy) vs. capital costs to install pipe.Cost Analysis1. Design building based on major processes, equipment, and material flows including pipe runs.2. Locate pumps to minimize pipe length and bends. 3. Select pipe diameters and size pumps as a system based on life cycle analysis. 1. Design building based on major processes, equipment, and material flows. 2. Locate pumps.3. Layout pipe runs.4. Select pipe diameters.5. Calculate frictional losses and TDH.6. Size pump based on prior decisions and calculations..Engineering StepsProposedTraditionalPUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLELIFE CYCLEDecision VariablesDecision VariablesDDii= pipe diameter (4= pipe diameter (4””, 6, 6””,8,8””,10,10””,12,12””))PPjj= Pump Selection (12hp, 18hp, 20 hp, 25hp, = Pump Selection (12hp, 18hp, 20 hp, 25hp, 30hp)30hp)DDiiPPjj= Binary Decision Variable representing = Binary Decision Variable representing optimal combination pipe optimal combination pipe diadiaand pump sizeand pump sizeSystem Head (TDH) = Change in Elevation (∆Z) + Energy Loss due to Friction (Hf)Bernoulli EquationSIZING A PUMPPUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM LIFE OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLECYCLEFriction AnalysisFriction AnalysisPipe:Pipe:HHff= fL= fLVV22/2gD/2gDFittings:Fittings:HHff= k= kVV22/2g/2gFluid Flow Fluid Flow Q = VAQ = VAArea increases, Velocity Area increases, Velocity decreasesdecreases……Hence, larger diameter pipe Hence, larger diameter pipe will lower friction losses!will lower friction losses!SYSTEM AND PUMP CURVESSYSTEM AND PUMP CURVES25456585105125145165300 400 500 600 700 800 900 1000 1100Flow (gallons/min)Head (ft)30%40%50%60%70%80%90%100%110%120%130%140%150%160%170%180%190%Efficiency (np) System Curve(8 inch diameter)Pump Performance Curve(18 horsepow er pump)Pump Efficiency Curve(18 horsepow er pump)Target Flow Constraints related Hydraulic Design:∑ Di Pj = 1 - Select one pipe diameter/pump combination.Max. Hpump ≥ TDH - Selected pump has Maximum Head greaterthan System Head at Flow Q.SYSTEM AND PUMP CURVESSYSTEM AND PUMP CURVES25456585105125145165300 400 500 600 700 800 900 1000 1100Flow (gallons/min)Head (ft)30%40%50%60%70%80%90%100%110%120%130%140%150%160%170%180%190%Efficiency (np) 12 " D i a.10 " D i a.8" Dia.6" Dia.18 h p30 hp12 h p25 hp12 h pEff iciency18 h pEff iciency25 hpEff iciency30 hpEff iciencySystem CurvePump Performance CurvePump Efficiency CurveTarget Flow Constraints related Hydraulic Design:∑ DiPj= 1 - Select one pipe diameter/pump combination.Max. Hpump≥ TDH - Selected pump has Maximum Head greaterthan System Head at Flow Q.PUMP SYSTEM DESIGN:PUMP SYSTEM DESIGN:OPTIMIZING TOTAL COST OVER SYSTEM OPTIMIZING TOTAL COST OVER SYSTEM LIFE CYCLELIFE CYCLEOptimization ModelOptimization ModelPumping system design by selecting two components, Pumping system design by selecting two components, pump size and pipe diameterpump size and pipe diameter, based on their impact on , based on their impact on the system life cycle.the system life cycle.MinimizeMinimize--Capital costs for purchasing and installing pumpCapital costs for purchasing and installing pump--Capital costs for purchasing and installing piping Capital costs for purchasing and installing piping systemsystem--Operating costs due to pump energy consumed over Operating costs due to pump energy consumed over life cycle (20 years)life cycle (20 years)SUMMARY OF MODEL INPUTSSUMMARY OF MODEL INPUTSFrom Hydraulic From Hydraulic CalcsCalcs::TDHTDHii= System Head at Flow 750 = System Head at Flow 750 gpmgpmfor each pipe ifor each pipe iFrom Pump Curves:From Pump Curves:Max H = Max pressure added at 750 Max H = Max pressure added at 750 gpmgpmfor each pump jfor each pump jηηpijpij= Hydraulic Efficiency for each specific = Hydraulic Efficiency for each specific ijijpairpairηηmjmj= Motor Efficiency for each pump j= Motor Efficiency for each pump jFrom Cost Estimates:From Cost Estimates:CCii= Capital Costs to install each piping system i= Capital Costs to install each piping system iCCjj= Capital Costs to install each pump j = Capital Costs to install each pump j EijLinear OptimizationLinear OptimizationDecision VariablesConstants from engineering calcsFlow - Q0 (gpm):750 Energy calcsNumber of Pumping Systems - n: 15 Constants from pump manuf. inf.Decision variablesAssumed valuesP1 P1 P1 P1 P1 P2 P2 P2 P2 P2 P3 P3 P3 P3 P3 P4 P4 P4 P4 P4 P5 P5 P5