A STUDI OF AN NPP UNIT WITH THERMAL POWER ACCUMULATORS DURING THE REGULATION OF TURBINE POWER IN DISCHARGE MODE

The article presents the computational and analytical research results onf the static and dynamic turbine characteristics of a Nuclear Power Plant (NPP) unit with a thermal energy accumulation system (TEAS) in discharge mode. Such research is necessary since NPPs are required to participate in the electric load schedule and to regulate the frequency of electrical current, while the reactors have a low flexibility for participating in these modes. The study was performed for one of the previously developed draft versions of the NPP-2006 project with a VVER -type 1200 MW reactor, a K-1200-6,9 / 50 turbine and a TEAS. The issues, discussed in the article, concern static and dynamic turbine characteristics over the whole possible power range of the NPP unit in TEAS discharge mode with constant values of operating parameters of reactor and regulation of the turbine power by changing the value of the regenerative bleed-off. The study has been conducted with the goal of verifying that the NPP with a TEAS and the above-described power regulation parameters is in compliance with the regulatory on turbine power change rate for NPPs participating in the primary frequency control of the electrical current network. The research results can be applied to any types of NPPs with VVER-type reactors and TEAS.