BOUNDARY CONDITIONS OF HEAT EXCHANGE IN THE LACE SEALS OF CYLINDERS OF HIGH AND LOW PRESSURE OF TURBINE K-1000-60 / 3000

Abstract

Purpose. Investigation of operating conditions of a wet-steam turbine with a capacity of 1000 MW, development of a calculation procedure and determination of the boundary conditions for heat transfer for end seals of high and low pressure rotors in the variable operating modes of power units for the subsequent evaluation of low cycle fatigue of the K-1000-60 / 3000 turbine rotors, determining the degree of possible damage to the main metal, calculating the residual operating time, as well as an individual resource. Methodology. When modeling the geometry of the seals, the first stage of verification calculation developed a technique for creating spatial structures of turbomachine elements using the Solid Works software and the mathematical calculation method, which is embedded in it (the finite element method) for the RVD and RND. Findings. The boundary conditions of the sections of the end seals of the RVD and RND at the starts from cold, non-heated and hot states are calculated taking into account the change in the regime parameters. It is established that the value of the heat transfer coefficient increases with increasing turbine power and has a maximum value at the nominal mode. The maximum value of the heat transfer coefficient for the RVD is α = 2168.8 W / (m2 K), for RND α = 701.5 W / (m2 · K). An approximating dependence of the heat transfer coefficient for the initial section of the high-pressure rotor on the relative steam consumption on the turbine in the range 0.4-1.0 has been obtained. Originality. The authors for the first time calculated the values of the heat transfer coefficient for the end seals of high and low pressure rotors for three types of starting-from a cold, non-heated and hot state, depending on the thermal state of the rotors and the relative steam flow to the turbine. The approximated dependence of the heat transfer coefficient for the initial section of the high-pressure rotor on the relative steam consumption on the turbine in the range 0.4-1.0 makes it possible to perform the necessary calculations for other types of starts and the temperature states of the rotors. Practical value. The results of calculating the heat transfer coefficient at the sections of the RVD and RND end seals during starts from different thermal states make it possible to calculate the thermally stressed state of the turbine rotors and to estimate the value of the low-cycle fatigue of the CVP and LPC rotors.

Keywords

• steam turbine
• front end seal
• rear end seal
• starting from a cold, hot, unfired condition
• heat exchange in seals
• border conditions