EXERGY

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EXERGY

• Real-time Efficiency Analysis for Power Stations

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The issue

• You need the ability to detect and diagnose
  efficiency problems in a thermal power station.
• You need your operators to be able to react to
  the diagnoses and restore the unit to a higher
  efficiency.
• This can add significantly to the operational
  profits of the station and result in lower CO2
  emissions.

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EXERGY Real-time Efficiency analysis

• Less Fuel Less CO2 More profit

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What is EXERGY?

• EXERGY is a tool for detecting and diagnosing
  efficiency problems in thermodynamic processes
• EXERGY saves operating costs. It has a unique
  ability to detect problems, diagnose causes and
  recommend remedial actions. It also allows
  operators to prioritise problems by providing an
  estimated cost per hour of the problem.

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What is EXERGY?

• EXERGY is the ONLY software available for
  continuous efficiency monitoring that is based on
  sound physics.
• EXERGY gives you continuous online efficiency
  monitoring
• EXERGY lets you pinpoint efficiency losses
• EXERGY delivers instant reporting and diagnostics
  
• EXERGY finds the root cause of problems,
  automatically
• EXERGY is the only software that calculates 2nd
  Law efficiency for your power station processes.
  It allows trending of component efficiencies and
  drill-downs to locate sources of problems .

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How EXERGY works Background

• Plant efficiency management in the first instance
  is concerned with the Heat Rate, a 1st Law
  measure of efficiency.
• Ultimately a plant wants to produce as much
  output for the least expenditure of fuel.
• When plant efficiency deteriorates, either
  through incorrect operation, sudden failure in a
  component or through gradual loss of condition,
  the challenge is to find the cause and then cost
  the value of repairs.
• 1st Law measures of component efficiency are not
  useful for this analysis.

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How EXERGY works Background

• In contrast, 2nd efficiency measures are ideally
  suited for this task.
• Exergy (availability) losses are additive (i.e.
  the total exergy loss for the plant is the sum of
  all the component losses), enabling attribution
  of the losses to plant components.
• The plant is modelled as a hierarchy of
  components, starting with entire plant. Losses
  can be tracked from top level of the plant to
  individual components.

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How EXERGY works Background

• Entropy is additive
• Entropy (and Exergy) is not a conserved quantity
• Unit heatrate trend correlates exactly with
  Exergy loss trend
• These properties enable a quantitative method for
  determining the root cause of heat rate
  excursions.
• The resultant diagnostics procedure is valid both
  for short term ( real time) and long term.

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Thermal Plant Efficiency

• The plant state at commissioning should be
  optimal
• Variance from optimal due to
• Gradual deterioration of components
• Failure of components
• Sub-optimal/incorrect operation
• EXERGY detects the root cause of any efficiency
  loss.
• Alarms when efficiency excursions occur with
  operating recommendations

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EXERGY alarms

• Efficiency excursions result in alarms
• Alarms go to
• Email if desired.
• Client PCs
• A central database

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Example Exergy alarm
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Exergy Alarm Analysis
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An example EXERGY audit Bayeswater Station, NSW
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EXERGY audit as it happened, Bayeswater
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Exergy audit as it happened, Bayeswater
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Real Measurements, Bayeswater
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Overview of Exergy Components
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EXERGY installation

• Installs on MS Windows Server
• Interfaces with OsiSoft PI
• But custom interfaces can be used instead
• Reads instrumentation writes back results
• Communicates with clients over TCP/IP network

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Contact us

• exergy_at_gns.cri.nz
• www.powerstationefficiency.com