DEVELOPMENT AND EXPERIENCE IN IMPROVING REGENERATION SCHEMES AND EQUIPMENT OF TURBINES WITH A CAPACITY OF 100 – 800 MW

In the Russian energy sector, the process of modernization of turbine units with a capacity of 100÷800 MW is underway aimed at increasing their capacity and improving the efficiency of the wheelspace of turbine units. The modernization focuses on the design of the flowing part of turbines, which allows to obtain a significant, but not a complete, modernization effect, since the regeneration scheme and its equipment remain the same. In the best case, old equipment is replaced with newly manufactured one which was still designed in the 1970s – 1980s. Improvement of thermal schemes of power units of all types is one of the priority tasks for improving operational and technical and economic indicators of TPPs. The regeneration scheme increases the efficiency of the cycle by 12÷14%; therefore, its modernization, provision of new highly-efficient and reliable equipment, a reduction in the underheating of the main condensate and feed water, and the hydraulic resistance of their paths can have a significant positive effect and help to save fuel. The article presents the shortcomings of the existing regeneration schemes, summarizes the selection criteria and gives options for regeneration schemes for 100÷800 MW turbine units. Different solutions are proposed, both in terms of the composition of the equipment and the structure of the regeneration scheme. A comprehensive approach has been implemented in the development and modernization of turbine regeneration schemes. The designs of low and high-pressure heaters have been developed with reference to the adopted regeneration scheme. The accumulated experience of introducing mixing heaters and using no-deaerator thermal circuits is generalized. The proposed solutions for the modernization of the regeneration scheme, the composition and type of equipment can be implemented for turbine units of various capacities.

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