Power + Energy Associates

Thermodynamic Performance Analysis


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Performance Analysis - Monitoring and Improvement

Power + Energy Associates are consultants providing expert advisory, site and support services in the field of thermal power and other energy related plant design, engine performance testing, performance analysis and performance improvement. Our activities include desktop analysis, site investigation and site testing. We are specialists in the provision of Thermodynamic Cycle studies and Thermodynamic modelling for new and existing plants. Our work as independent performance engineer covers new and existing facilities, P+EA has an extensive experience in this area including more than 300 performance tests. We provide advice on the development of new facilities as well as routine and annual performance reviews on existing plants. We witness official tests and also undertake, organise, supervise and arrange tests.

Steam Mollier Diagram

The Need

Thermal efficiency of an engine or power plant is the comparison of the energy content of the input fuel turned into electrical energy by the engine or generating station. With the industry focus on spark spreads and ever increasing fuel costs; efficiency and performance are clearly key drivers for the profitability of any power generating station. Today the drivers also include limiting emissions and of course improving thermal efficiency is also directly linked to reduction of emissions.

Thermal power plants, gas turbines, engines and combined cycle power generating facilities may well have been designed to operate in one operational mode but more likely too for flexible operation under different configurations and part load conditions. Each operating configuration is likely to present different performance issues. As the plant ages the load factors change and a new operational emphasis emerges. Each Operator is obliged to deliver efficient plant performance, seek the most efficient utilisation of fuel and utilise appropriate maintenance to achieve these targets.

Performance Engineer Role

Performance analysis and performance monitoring are seen as essential for the achievement and maintenance of engine and power plant performance targets and improving performance.

The independent performance engineer works alongside the project and power plant personnel to provide additional expertise and advise on how best to achieve the expected performance with optimum operating costs. These considerations will include not only plant overall output and thermal efficiency but also component performance and emissions. Each plant will be fitted with certain facilities enabling performance recovery with a minimum of down time, such as on-load cleaning and other features. Decisions may also need to be taken on modifications needed to optimise performance. Right up front in the development programme agreement is needed on the facilities required for recovering performance. Project agreements all require careful study in relation to the operating parameters and performance guarantees.

Steam Mollier Diagram

About Testing

There is no better way to establish how a plant is performing than to carry out a properly arranged and supervised performance test. These tests are best carried out when the plant is new (before start of commercial operation) then both annually and after major outages. When performance upgrades are implemented it will be required that the plant is tested before and after the upgrade implementation.

Thermal performance tests are essential to verify overall power plant outputs and heat rates.  All thermal Power Plants need to undergo rigorous acceptance testing in order to comply with Contracts and Project Agreements. Expert supervision of performance tests is needed to confirm performance and environmental guarantee compliance. The expert performance engineer may propose that additional non-contractual tests are carried out to ensure that the plant operator has benchmarks against which to monitor the plant operational performance. Verification of the correction curves will be needed. On line fuel analysis will prove to be important together with the services of reliable independent laboratory. Plant component performance evaluation such as boiler, turbine and condenser performance will prove valuable benchmarks. Tests will be required to be carried at several loads and/or different configurations.

Test Codes and Test Procedures

During the project development the appropriate performance test codes need to be agreed and these used as the basis of testing procedures. Choices will be made between various international codes. Preparations for the tests will be important with test procedures and analytical performance test models being developed prior to the start of testing.  Contractor documentation will need to be reviewed. The tests will require the installation of special test instruments and calibration of a selected number of permanent plant instruments. The successful completion of these tests will signal that the plant is ready for commercial operation and is of course a major event the life of any plant. The test procedures will also form the basis of future plant testing.

"P+EA is an active member of several BSI/ ISO technical committees on test codes and technical standards."

Steam Mollier Diagram

Performance Assessment and Modelling

Assessment of performance on an existing plant will involve extensive discussions, document reviews and checks on available performance records. Fuel analysis and measurement will prove to be of high importance including employment of on-line fuel chromatography feeding data directly to fuel flow computers. Following on the periodic testing will be of great value in verifying plant performance, achieving optimum performance, acquiring data and looking for performance shortfalls.  So called annual or “anniversary” tests are called for in many project agreements and off-take agreements.

"We have a vast experience in thermodynamic modelling covering all types of thermal power plants and prime movers. We have created a large number of bespoke models all specific to each plant and meeting the needs of the client." 

Performance modelling may well assist in predicting and enhancing plant performance. Advances in technology are continuously appearing and these need to be justified as every upgrade represents capital investment needing economically justified. A performance model will be the tool to enable the assessment of these cases. Operations teams need a good understanding of performance to successfully monitor plant performance and training courses will cover performance analysis, heat rate improvement and the concepts behind thermal and combined cycle performance.

Performance Degradation

Performance degradation is always an important consideration. Degradation is a fact of life and every plant is subject, to a greater or less degree, to degradation in output and heat rate. Accurate performance data is essential for day-to-day operation and billing purposes and avoid significant financial loss to the Owner. Recovering performance will require action with performance and maintenance being linked. Good performance analysis will detect changes in the plant, which will be used to determine when maintenance is to be scheduled.

Anyone requiring more information about these matters or wishing to discuss performance issues is cordially invited to contact us at Power + Energy Associates.

  • Combined Cycle Power Plants
  • Cogeneration Power Plants
  • CHP and Biomass Power Plants
  • Conventional Thermal Power Plants
  • Gas, Biomass, Coal and Lignite
  • Waste Recovery Energy
  • Combustion
  • Steam Generation Plant
  • Steam Turbines
  • Gas Turbines
  • Industrial Boilers
  • Process Steam and Steam Distribution

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