Энергетический баланс и показатели тепловой экономичности энергоблока атомной электрической станции

Abstract

The Guidelines for drawing up a technical report on the effectiveness and thermal efficiency of nuclear power plant operation that have been developed at the All-Russian Research Institute for Nuclear Power Plants Operation (VNIIAES) contain a recommendation according to which the thermal power supplied to external consumers should be determined taking into account the heat transferred to the delivery water in the power plant's district heating installation network pumps. Similarly, the thermal power consumed for power generation should be determined taking into account the heat transferred to the primary circuit coolant and to the secondary circuit working fluid in the pumps installed in the NPP thermal process cycle circuit. The thermal energy transferred to the water in the NPP process circuit pumps is noticeably smaller than the electric energy (in the same units of measurement) supplied to the pump driving electric motors, and the total power consumed by the drive motors is less than the total electric power consumed for the power unit auxiliaries. The energy balances of an NPP power unit equipped with a VVER reactor and of its main process installations, namely, the nuclear steam supply system (NSSS) and the steam turbine plant (STP) are drawn up as applied to their operation in the steady-state mode. The obtained balances were used to derive formulas for calculating the thermal efficiency indicators: the gross and net electric efficiency values. In drawing up the energy balances separately for the NSSS and STP, their performance efficiency indicators were determined. The results of calculations using these formulas for a power unit equipped with a VVER-1000 reactor, the thermal process circuit of which incorporates only electric motors as pump drives, are taken as an example. The obtained results show that the additional heating of water in the pumps has a noticeable influence on the thermal efficiency indicators, a conclusion that seems to be of importance at the present stage of designing the thermal process circuits of NPP power units.