Hitachi, Ltd.

Hitachi-ge Nuclear Energy, Ltd.

Koji Namba

Takanori Shibata

Shigeo Hatamiya

Susumu Nakano

Koji Nishida

A boiling water nuclear power plant supplies steam from a reactor to high-pressure and low-pressure turbines. Feed water generated by condensing steam in a condenser is heated by low-pressure and high-pressure feed water heaters and supplied to the reactor. The steam discharged from the low-pressure turbine is compressed by a steam compressor and supplied to one of the low-pressure feed water heaters to heat feed water. The steam extracted from the low-pressure turbine is supplied to the low-pressure feed water heater. When power required for the steam compressor is Q, heat energy supplied from the steam compressor is Q, a coefficient of performance of the steam compressor is COP (=Q/Q), and a thermal efficiency of the boiling water nuclear power plant is &#x3b7;, the steam compression apparatus is connected to a position in a main steam system and to the feed water heater so as to satisfy COP&#x2212;1/&#x3b7;&#x3e;0.

Power plant

An electric power plant supplies steam generated to a high-pressure turbine and a low-pressure turbine. The steam discharged from the low-pressure turbine is condensed with a condenser. Water generated with the condenser is heated with a low-pressure feed water heater and a high-pressure feed water heater. The steam extracted from the high-pressure turbine is supplied to the high-pressure feed water heater. The steam extracted from the low-pressure turbine is compressed with a steam compressor, and the steam whose temperature has been increased is then supplied to the high-pressure feed water heater. The feed water is heated in the high-pressure feed water heater by the steam extracted from the high-pressure turbine and the steam compressed with the steam compressor. Because the feed water is heated by the extracted steam and the compressed steam in the high-pressure feed water heater, the amount of power consumed by the steam compressor can be reduced.

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Mito, Japan

Koji Namba