Case study

When lighter loads cause turbine efficiency to tumble

Industry: Electric power generation

ISSUE

Increasing hour of operation in lighter loads

Due to significant market penetration by renewable energy resources, a utility company has been forced to turn down the load on their gas turbines which compromised the fuel economy of the power plant because of lower thermal efficiency. In some of available options, it is found that Inlet Guide Vane (IGV) safe operation guidelines had margin for improvement which would increase the exhaust gas temperature and hence, the overall thermal efficiency.

Manual adjustment is not the solution

In the interest of safety and reliability, the maximum exhaust temperature of a gas turbine is limited, to ensure several parameters do not exceed the design specifications. When a turbine changes load or receives sudden frequency response, these parameters become unstable, making it difficult to perform IGV adjustment manually without jeopardizing the safety of the turbines.

Image of Turbine

SOLUTION

KEY POINTS TO THE SOLUTION

  • A carefully engineered algorithm optimizes the control setting of IGV in safe and reliable
  • No need to allocate additional budget for the initial outlay
  • Free to deactivate in case the efficiency uplift did not match expectations

A carefully engineered algorithm optimizes the control setting of IGV in safe and reliable

With IGV Optimization, a carefully engineered algorithm optimizes the control setting of the inlet guide vanes that keeps the control parameters below limits while maintaining the current operational reliability and flexibility, such as frequency response capability.

No need to allocate additional budget for the initial outlay

Because the cost of the system is proportional to the efficiency gains made, there has been no need to allocate additional budget for the initial outlay.

Free to deactivate in case the efficiency uplift did not match expectations

The plant management was free to deactivate the IGV Optimization in case the efficiency uplift did not match expectations. Hence, there was no financial risk to the customer.

EXPECTED OUTCOME

On average, combined cycle thermal efficiency has increased by +0.6%abs.

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