gepump performance optimization

8/12/2019 GEpump Performance Optimization

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Pump Performance Optimization

Increased production Higher efficiency Compliance with environmental regulations Availability and Reliability Life extension

Customer benefits include:

Higher efficiency

Alignment with plant needs

Solving vibration problems

Dramatic reduction in operation and maintenance costs

Energy savings

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Pumps & Valves

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Our customers most frequentrequests relate to match new plantoperating points with existingmachines originally designed fordifferent conditions.The most frequent customer needsare:

Increasing flow rate:Pipelines, refineries, petrochemicaland power plants need to increasetheir productivity without capitalinvestments.Consequently, pumps, as keycomponents of the stream, need toprocess higher volumes withrespect to their design flows. In this

situation we are able to design andimplement the necessarymodifications to meet newoperating point objectives whileremaining within API operatingstandards.

Increasing Mean Time BetweenFailure (MTBF ):In order to improve plant efficiency,customers are always seeking toreduce turn down, especially if it isunplanned. In that case we candevelop new solutions, redesigncomponents and/or introducenew materials that increase thedurability of our machineries.


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Customer pump analysisThe GE Oil & Gas approach startsfrom a detailed analysis of theexisting pump configuration andmargins for matching the new target.Then the assessment turns to: Establishing the feasibility of the

request and how the new targetwould impact the pump design

Analyzing the modifications thatwould be possible to increase the

performance of the machine whilestill complying with API standards

Pump optimization for customerobjectivesWe use a variety of tools forsimulating modifications to the pumpdesign in order to validate potentialmodifications to match the newtarget point. Figure 1 shows a schemeof the study approach.The primary approaches employed are:

Engineering expertise for similarreferences: as the OriginalEquipment Manufacturer (OEM), wecarry out all technical appraisals ofpotential modifications consultingan extensive list of similarreferences

Rotor dynamic software: we areable to examine, enhance andverify rotor stability, and evaluatethe impact of the upgrade on therotordynamic behavior of the

specific machine Computational Fluid Dynamics

(CFD) software is used forsimulating the designmodifications. This allows us toobtain all performance resultsrelated to the modifications withinan accuracy of 5% (Figure 1)

Our Centrifugal Pump Configurator(CPC) is a web based applicationintegrated with a centralized

database that is able to provide uswith pump curves based on thecalculations from the above

mentioned CFD software and testresults from the existing fleet(Figure 2)

SolutionsImpeller modifications based on thesame impeller shape Varying external diameters to shift

the Head vs. Flow performancecurves upward or downward. TheBEP (Best Efficiency Point) is also

shifted toward the new operatingconditions yielding better efficiencyat the operating point

Reducing vibrations:Lower vibration levels usuallyindicate a better machineryoperating state, greater MBTF andlonger life.To keep vibrations at the lowest

levels, it is important that the pumpoperates as close as possible to theBest Efficiency Point (BEP), andmany pump modifications arefocused on move the BEP to theoperating point.

Revision of operating point:When significant variations inplant performance are required,it is much more convenient forthe customer to have existingmachinery modified rather than

making changes in the plantlayout. Our team has thenecessary experience and designtools to reliably reconfigurepumps to match new performancepoints.

Increasing efficiency:It is obvious how increasingefficiency helps to achieve energysavings. Considering that pumpsusually operate in continuousservice, even a few percentage

points of efficiency increase havean immediate pay back on energysavings. This is an area of plantimprovement on which to focus.

0.11 0.220.00 0.33 0.44 0.55 0.66 0.77 0.88 0.99

Raked Trim

Chipping Volute

Underfilling

Overfilling

Channel Cleaning

Cleaning Impeller Inlet

Volute Constriction

Bull Ring (inlet eye reduction)

Orifice 71

Modify CurvesList of Projects New Configuration Other Projects View Technical Data

Figure 1: Graphic interface of GE Oil & Gas centrifugal pump configurator while simulating modification


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Different trims on impeller vanes(i.e., racked, V-trim, etc.) and/orunderfilling/overfilling (Figure 3) tomodify the shape of theperformance curve to better matchcustomer needs (Figure 5)

Change of impeller designThe possibility of installing in theoriginal pump casing an impeller witha new design selected from a widerange of proven GE Oil & Gas impellerpatterns in order to achieve the desiredperformance can be evaluated usingdetailed simulation tools.

De-staging or Re-stagingRemoving (or adding to a previouslyde-staged pump) one or moreimpellers from a multistage pump(Figure 4) allows the performancecurve to be moved upward ordownward, achieving roughly thesame effects as modification of thediameter.Though the BEP position will bedifferent, the most feasible solutionwith respect to the operating pointcan be chosen.

Volute / Diffuser modificationsThe geometry of the static channelshas a dramatic impact on theperformance of a centrifugal pump.Thus modifying parameters such asthe volute cross sectional area, the

position of the volute cutwater, andthe shape and distance of thecutwater to the impeller providessignificant flexibility in the shape ofthe performance curve.A CPC analysis gives a range ofsuggested modifications to achieve adefined operating point.

Volute cleaning and coating of thecasing with ceramic paintSaving energy is a key issue in plantoperations today. In centrifugal pumps,the efficiency is directly affected by thefriction encountered by the processfluid as it passes through the pump. Forthis reason optimum surface finishingis required to reduce friction.Further reduction can be achieved byapplying specialized ceramic coatingsalong all the channels. A recentintroduction in the pump industry, thisprocess produces very positive resultswith regard to the ability to reach andtreat even very narrow areas such as

impeller vanes in multistage pumpswhich cannot be reached for polishing.

Performance Curves

Figure 2: Centrifugal Pump Configurator (CPC)

Proposal No *Item No *Selection NoDate *

Pump Size & Type 8x14-DS THFNumber of Stages 2Curve Reference No Sp-240 000/000/000

42876/SDImpeller 1st stg. 4282529/1881-H

54126/SDImpeller 2st stg. 25625/3056-HRated Impeller Diameter 330.9 mmMax Impel ler Diameter 355.6 mmMin Impeller Diameter 279.4 mmEye Area 390.32 cm^2Specific Speed NS (US) 1209SSS (US) 9499

The pump is guaranteed for the following set ofperformances with H2O. Performances plottedat other capacities are approximate.

Applicable API 610 X Ed. -ISO13709Standard 2005Rated Capacity 346.0 m^3/hTDH 230.0 mRotational Speed 2980 RPMNPSHR 3% @imp. CL 5.5 m

Rated Efficiency 67.8 %Rated Power@SG=1 319.9 kWRated Power 290.3 kWMCSF 146.4 m^3/hPumped LiquidOperating Temp. (O.T.) 355.0 deg CSpecific Gravity@ O.T. 0.901Kinematic Viscosity 6.0 cSt

Viscous correction factors:CE: CQ: CH:0.993 1.0 1.0

Figure 3: Metal removal on impeller

Figure 4: Destaged pump

Metalremoval

ED ExternalDiameter

Starting from the customers request, the system analyses the data and suggests the best solution

NPSHR= Net Positive Suction Head Required


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gepump performance optimization

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