Study of the operation of a 110 MW combined-cycle power unit at minimum loads when operating on the wholesale electricity market

Abstract

Currently, all generating equipment with a capacity of more than 25 MW operates in the wholesale electricity market. The operation of combined cycle gas turbines is complicated by the implementation of daily load schedules. A distinctive feature of the operation of combined-cycle units is the presence of a gas and steam turbine in the cycle. In this paper, the variable operating modes of a combined cycle plant are considered. The minimum effective load of a gas and steam turbine is determined. An example of the real operation of a steam turbine that is included in a combined cycle plant 110 MW power unit at an operating combined heat and power is shown. The optimal minimum load of a combined cycle gas turbine unit has been determined. As a result of the research, the values of high and low pressure steam flow rates, fuel gas consumption, steam and gas turbine power were obtained. Based on the research results, the optimal minimum load of a combined cycle gas turbine unit was found - 40 MW. This load allows the main and auxiliary equipment to work without compromising reliability.

Keywords

• combined cycle plant
• gas turbine unit
• plant operating modes
• electricity market
• power dependence on external conditions
• initial parameters