Commonwealth Chesapeake Co. LLCis a Virginia, U.S.A.-based power gener-ating company that operates the Com-monwealth Chesapeake Power Station, acombustion turbine peaking plant fueledby low-sulfur fuel oil that was sold to TyrEnergy Inc. in February 2008.

The Chesapeake Power Station in-cludes seven GE LM 6000 simple-cyclegas turbine electric gen-sets that are ableto produce 315 MW of electricity —enough to meet the energy needs ofapproximately 300 000 households. Theplant delivers energy to PJM Intercon-nection, a regional transmission organi-zation (RTO) that coordinates the move-ment of wholesale electricity to largeareas in the East, Northeast and Midwest.

The plant was built in two phases —the first in 2000 and the second in2001 — on a 51 hectare tract on theDelmarva Peninsula, a large peninsulaon the East Coast of the United States,occupied by the states of Delaware andportions of Maryland and Virginia.Three generators were installed in thefirst phase and four more were brought

world, the plant’s team of equipmentoperators would take readings everyquarter and come back with recom-mendations such as the need to moni-tor a particular bearing or issue amandatory replace order. But becauseits equipment isn’t running 24/7, theplant doesn’t have that luxury. If theturbines aren’t running, there is no datato collect. It’s that simple. It also meansthat a successful preventive mainte-nance program is difficult to sustain.

As a result, when the turbines are upand running, the plant’s operators mustcollect as much data as possible in a rel-atively short timeframe. Not knowingwhen their next opportunity may be tocollect information, they must makesure that the data is thorough, accurateand analyzed quickly in order to detectany readings outside the norm andestablish a plan for repairs.

At the outset of the program, Com-monwealth Chesapeake selected AzimaDLI’s DCX for its operators to handledata collection and analysis. The AzimaDLI DCX is a four-channel, Windows-compatible portable vibration datacollector with embedded data acquisi-tion hardware and automated diag-nostic software.

The DCX embeds Azima DLI’s Expert-ALERT vibration analysis system soft-ware, so at the point of data collection,users have all of their machinery history,analysis tools and automated diagnosticresults available. This immediate accessto important machine data allowsCommonwealth Chesapeake to easilyshare data, get a second opinion if neces-sary, and rapidly identify a plan of action.

An effective vibration monitoring pro-gram that includes access to detailedanalysis and reports to back it up, allowsCommonwealth Chesapeake to demon-strate that it is taking the appropriatesteps to achieve machine reliability.While not required by law, yet, focusingon machine reliability is a good businesspractice for plants like CommonwealthChesapeake as they strive to adhere toestablished guidelines set forth by theFederal Energy Regulatory Commission(FERC) and the North American ElectricReliability Corp. (NERC).

Like many U.S.-based power plants,

Commonwealth Chesapeake operators reviewing vibration data on one of the plant’s genera-

tor lubricating oil pumps.

online in the second phase. The plantfeatures “spinning reserve” capacity onfour turbines to provide a ready andreliable regional power source.

As a peaking plant, CommonwealthChesapeake’s turbines are not runningconstantly, but it’s critical that they bein top condition in order to supplyreserve energy with very little notice,and often times in emergency situa-tions. Within the first few years of oper-ation, Commonwealth Chesapeake ini-tiated a comprehensive machine condi-tion monitoring program aimed atensuring the reliability of critical equip-ment, enabling it to get out ahead ofmajor repairs.

In 2002, Azima DLI, a global condi-tion monitoring services company, andstrategic partner PdM Solutions werebrought onboard by CommonwealthChesapeake to help develop its in-house vibration analysis program. Theplant is currently using an Azima DLIdata collector and the company’s ana-lytic software, along with training andsupport from PdM Solutions.

Commonwealth Chesapeake facesseveral challenges with its vibrationdata collection program. In an ideal

December 2009 Diesel & Gas Turbine Worldwide

POWER GENERATION BY TONY ALVELO

PM for Peak PowerWhen Commonwealth Chesapeake is called on for power, the operators must be confident that the plant can deliver

Tony Alvelo is the lead operator, Common-wealth Chesapeake Power Station.

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Az AZIMA DLI hivatalos magyarországi képviseletét a Delta-3N Kft. látja el. Delta-3N Kft. 7030 Paks, Jedlik Á. u. 2. Tel.: +36-75-510115 Fax: +36-75-510114 www.delta3n.hu

major failure with one of the chillers. One of the plant operators recently

collected data at the end of the summer,ran it through the Azima DLI Expert-ALERT diagnostic software and receivedan indication for a major repair. Com-monwealth Chesapeake operators want-ed a second opinion before schedulingthe work. Using the Azima DLI system,they were able to share data with thePdM Solutions team, who confirmed thediagnosis and the plant was then able toprioritize the repair.

Considering the impact of a downedpeaking plant — that in an emergencycould leave hospitals, prisons and otheressential community infrastructure inperil — there is a lot at stake. With thesuccess of its vibration monitoring pro-gram that can be measured in terms ofequipment reliability, plant perform-ance and failure avoidance, Common-wealth Chesapeake is confident that itcan meet the power needs of its com-munity without fail. A

POWER GENERATION

Commonwealth Chesapeake undergoesregular audits by NERC where it mustdemonstrate it has effective processesand technologies in place to ensuremachine reliability. For example, theplant must be able to prove that all thesafeties are working on the turbines,otherwise the plant could risk takingdown the whole power grid.

If a plant fails an audit, it must set upa mitigation plan and is at risk of beingfined up to US$1 million a day per vio-lation. Therefore, CommonwealthChesapeake places a high priority on thesuccess of its machine condition moni-toring programs. The company’s rela-tionship with Azima DLI has helped theplant adhere to industry guidelines.Azima DLI has also assisted with estab-lishing best practices for machine relia-bility and uptime when it’s required.

When Commonwealth Chesapeake iscalled on for power, the operators mustbe confident that the plant can deliver.The ability to see in advance that a pieceof equipment is not performing is a sig-nificant benefit. With the sporadic oper-

ation of the turbines, not only is collect-ing vibration data a challenge, but it canpose a risk for equipment failure as well.Consider this automotive analogy — if acar was kept in storage for long periodsof time, one could not expect to take itout on the road for one day and expectthere not to be any knocking or stiffnessin the way it handles.

Translate this analogy to Common-wealth Chesapeake’s six duplex 2500ton chillers. This equipment is respon-sible for cooling the air that goes intothe turbines. These chillers are espe-cially important during summermonths, peak season for electrical use.

To ensure the chillers are in peakcondition, operators collect data at thebeginning of the summer usage cycleand then again at the end of the season.After analyzing this “before” and “after”data, operators can identify potentialfailures and set up a repair and mainte-nance schedule over the fall and wintermonths while they are not in use. In one particular case, this pattern of seasonal data collection avoided a

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Az AZIMA DLI hivatalos magyarországi képviseletét a Delta-3N Kft. látja el. Delta-3N Kft. 7030 Paks, Jedlik Á. u. 2. Tel.: +36-75-510115 Fax: +36-75-510114 www.delta3n.hu