POWER GENERATING UNITS START-UP PROCESS ASSESSMENT WITH THE RESPECT TO OPERATION COSTS

The paper formulates the problem of power units start-up processes assessment. An algorithm was developed to solve the problem with the respect to the costs of operation. The analysis concerned a chosen period of the power unit operation Delta t(0). The number Delta N(0) and the duration of the start-ups t(iota) are known for the given period Delta t(0). The main value under analysis is the start-Lip duration. The problem solution determines and compares typical start-ups (average start-up duration) and extreme start-ups (the shortest ones) for an analyzed power unit. The assessment regarded the influence of an increased or decreased start-up duration on the fatigue wear and start-up losses. An increased start-up duration leads on one side to lower fatigue wear of the turbine components but on the other hand to higher start-up losses. A decreased duration causes opposite effects. The paper describes the algorithm, which evaluates the start-up losses for a power generating unit. An economical assessment of the start-up processes was also conducted. The influence was determined of the shorten start-up duration on the operation costs.