Nuclear power plant with superheating reheater cooler than evaporator - gives high efficiency without adversely affecting reactor characteristics

摘要

A nuclear power plant comprises a reactor, a primary circuit, opt. also a secondary heat transfer circuit, and a steam generating circuit contg. an economiser, evaporator and super-heater and also an intermediate superheater (reheater) for steam drawn from an intermediate tapping point in the turbine. The heat supply to this intermediate superheater is provided by a tapping from the secondary heat transfer circuit (in the case of a three-circuit system as shown) or from the primary circuit (in the case of a two-circuit system) at the outlet from the evaporator; the heat supply fluid is returned to the same circuit (secondary or primary) at the low temp. side. Used for three-circuit systems esp. sodium-sodium-steam or two-circuit systems esp. gas-steam or water-steam. As compared with an earlier system where the heat supply fluid in the (secondary or primary) heat supply circuit was subdivided into two parallel flows, one for the main superheater and the other for the intermediate reheater, and then recombined before passing through the evaporator and economiser, the present arrangement permits a high thermal efficiency to be obtained without the need to increase the reactor core/diameter ratio with a consequent reduction in the regeneration of secondary fuel. Also, the situation of the intermediate superheater in a zone of lower temp. means that austenitic steel is not required for its construction.