EXERGY

1. EXERGY Real-time Efficiency Analysis for Power Stations

2. 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.

3. EXERGYReal-time Efficiency analysis Less Fuel = Less CO2 = More profit

4. 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.

5. 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 .

6. 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.

7. 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.

8. 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.

9. 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

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

11. Example Exergy alarm

12. Exergy Alarm Analysis

13. An example EXERGY audit: Bayeswater Station, NSW

14. EXERGY audit as it happened, Bayeswater

15. Exergy audit as it happened, Bayeswater

16. Real Measurements, Bayeswater

17. Overview of Exergy Components

18. 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

19. Contact us • exergy@gns.cri.nz • www.powerstationefficiency.com