MANAGEMENT OF FUEL CONSUMPTION OF 200 MW POWER UNIT WHEN OPERATING IN FREQUENT START-UP MODE

Abstract

In the context of insufficient maneuvering capacities in the United Energy System of Ukraine, 200 MW power units are used to cover peak loads in variable operating modes. At the same time, there is a deterioration in the economic performance of power equipment. The efficiency of power generation directly depends on the operating modes of the power unit. Therefore, the task was set to develop a system to rationalize operating modes in order to increase efficiency. The average annual specific fuel consumption was chosen as the objective function. To calculate the specific consumption during the year, the method of bringing all losses during start-up and stationary operation to similar consumption of conventional fuel was used. The following factors were selected as optimization factors: the power unit operation time during the year, the total number of starts from different thermal states for 1 year, and the proportion of starts from different thermal states. The limits of change in the factors were chosen as follows: the number of hours of power unit operation t_i from 2000 to 6500 hours per year; annual number of starts n_i from 25 to 75 times per year; the share of starts from the cold state of metal CS_i from 0.1 to 0.9; the share of starts from the hot state GS_j within the share of all starts (hot and un-cooled) from 0 to 1 The developed mathematical model allows to estimate fuel consumption for all possible combinations of operational factors. To demonstrate the operation of this system, calculations were performed for a specific 200 MW power unit with a TP-100 power boiler and a K-200-130 steam turbine. The main parameters of the power unit operation mode were determined using the start-up map and the operating instructions developed by the manufacturer. The calculations established a rational distribution of operating parameters, at which the consumption of conditional fuel is 334-340 g.c.f./kWh. It has been established that the rational number of hours of power unit operation is t_i = 5500-6500 h/year, with the annual number of starts n_i = 25-36 year^-1, while the share of starts should be: from the cold state of the metal CS_i = 0.72-0.9; from the hot state HS_j = 0.1-0.28; from the un-cooled state US_i,j = 0-0.18, and then the difference between the most rational and irrational operating modes is 16.5 % (fuel consumption of 55 g.c.f /kWh).