Conceptual methods of starting and controlling operating modes of compressorless combined cycle gas turbine unit

Abstract

A method for operation study of a compressorless combined-cycle gas turbine (CCCGT) unit during transients from one steady-state mode to another, including during start-up and shutdown, is proposed. As an example, studies of the transients of an energy complex with a capacity of 60 MW are given. A variant of an algorithm concept for start/stop and transients of such an energy complex is proposed. This concept includes algorithms for starting from the three initial states of the energy complex (cold, hot and standby). For these algorithms, the time and energy consumption characteristics are estimated. It is shown that from a cold state, such an energy complex can be started and brought to the nominal mode in 1.5-2 hours. At the same time, the energy costs will not exceed energy consumption for its own needs in a nominal mode. The start-up time from the hot state can be reduced to 20-25 minutes, and the start-up from the standby state can be 2.5-3 minutes. The proposed concept of control algorithms for transient modes is such, so that a temperature state of the main components and parts of the energy complex is provided at a constant temperature. Thus, the time of transients will be determined only by the speed of the regulatory authorities. Consequently, power systems operating on the CCCGT cycle can operate equally efficiently, both in the basic mode and in the power control mode.