Adjusting system and adjusting method for partial load efficiency of combined cycle unit

Abstract

The invention relates to the technical field of combined cycle power stations, in particular to an adjusting system and an adjusting method for the partial load efficiency of a combined cycle unit. The adjusting system comprises a gas compressor, a combustion chamber and a turbine which are connected in sequence; the combustion chamber is provided with a fuel valve; the gas compressor is providedwith a gas compressor outlet pressure measuring point, an inlet guide vane with adjustable opening, and an exhaust pipeline led to an air inlet chamber of the turbine; a cooling air temperature measuring point and an adjusting valve are arranged on the exhaust pipeline; the turbine is provided with a turbine outlet temperature measuring point and a turbine air inlet chamber pressure measuring point; and the inlet guide vane, the fuel valve, the adjusting valve, the cooling air temperature measuring point, the turbine outlet temperature measuring point, the gas compressor outlet pressure measuring point and the turbine air inlet chamber pressure measuring point are all connected with a control module. The adjusting method comprises the following step that when the partial load is smaller than 90% of the base load, the air-fuel ratio in the combustion chamber is adjusted according to an output target single under the partial load, so that the turbine inlet temperature is increased, thatis, the turbine outlet temperature is increased, and the combined cycle efficiency under partial load is improved.

Description

technical field [0001] The invention relates to the technical field of combined cycle power plants, in particular to a system for adjusting part load efficiency of a combined cycle unit and a method for adjusting part load efficiency of a combined cycle unit. Background technique [0002] In combined cycle power plants, gas turbines are mainly used as peak-shaving units, and most of the time they operate under partial load conditions. Part-load operation of gas turbine is of great significance to power plants, because it is not only directly related to the performance index of the gas turbine itself, but also related to the operating parameters of the steam turbine and the economy of the entire power plant operation. Therefore, how to improve the performance of gas turbines and combined cycle units under partial load is the most concerned issue for owners. [0003] The gas turbine control method adopted by the existing combined cycle unit is usually to control the turbine o...

AI Technical Summary

Problems solved by technology

[0003] The gas turbine control method adopted by the existing combined cycle unit is usually to control the outlet temperature of the turbine to keep basically constant. The adoption of this control method makes the efficiency of the unit running for a long time under partial load conditions not high

Some manufacturers also adjust the partial load condition by directly extracting compressor air, and the use of this method will reduce the efficiency of the combined cycle

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