Online optimization adjustment method for starting curve of gas-steam combined cycle unit

Abstract

The invention relates to an online optimization adjustment method for a starting curve of a gas-steam combined cycle unit. The method comprises the steps of: firstly, determining a steam turbine heating stage and a low load keeping stage as to-be-optimized stages, and selecting a first-stage metal temperature of a high pressure cylinder of a steam turbine as a unique influence factor; secondly, establishing a calculation model, solving rotor stresses and fatigue life losses at different heating times and low load keeping times, comprehensively considering a fatigue life loss cost and a fuel consumption cost of a rotor in a starting process, and determining the optimal time with the minimum total cost as a target on the premise of guaranteeing the rotor safety; thirdly, solving the optimal time at different first-stage metal temperatures of the high pressure cylinder of the steam turbine; and finally, solving a function analytical equation between the to-be-optimized stage and the influence factor. According to the online optimization adjustment method, the online dynamic adjustment for the starting curve of the gas-steam combined cycle unit is realized, the peak load regulation response time of the gas-steam combined cycle unit is reduced and the running economic level of the unit is improved.

Description

technical field [0001] The invention belongs to the technical field of start-stop optimization methods for a gas-steam combined cycle generator set, and in particular relates to an online optimization and adjustment method for a start-up curve of a gas-steam combined cycle generator set. Background technique [0002] In order to meet the requirements of the power grid for fast peak regulation and frequency regulation of generating units, it is necessary to further optimize the unit's fast load response and unit start-up time. The total installed capacity of gas-steam combined cycle units has been continuously increasing in recent years because of their high energy utilization rate, low pollutant emissions, and rapid start-up and shutdown. However, the steam turbine of the combined cycle unit takes a long time to start, which is the main factor that restricts the unit from responding to the grid's fast peak-shaving requirements in a timely manner. [0003] In the combined cy...

AI Technical Summary

Problems solved by technology

However, the steam turbine manufacturer only divides the start-up curve into cold, warm, and hot states according to the first-stage metal temperature range of the high-pressure cylinder, without considering the duration of the warm-up phase and low-load maintenance phase of the steam turbine when the metal temperature changes continuously may vary

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