Nikolai Kirillov, a designer from St. Petersburg, has developed a scheme for a new small nuclear submarine with a revolutionary power plant. He proposed combining a diesel unit, a small nuclear reactor, and an electric motor in it.
On the surface, the submarine should be propelled by diesel engines through a gearbox and a separate propeller shaft with a fixed-pitch propeller. This allows the diesel engines to operate at their nominal mode and reduces their wear.
When submerged, the diesel engines are switched off. Propulsion is provided by a separate electric motor with a controllable-pitch propeller, receiving energy from batteries.
The main feature of the scheme is a small water-cooled nuclear reactor that operates continuously, including when stationary. It does not directly rotate the propeller but generates electricity through an organic Rankine cycle and a generator.
The reactor maintains the battery charge in all modes. Thanks to this, Kirillov proposes reducing the power of the diesel engines, the volume of fuel reserves, and the size of the entire power plant.
The patent also provides for a two-circuit option with low coolant pressure. The author expects to reduce mass and size characteristics and radioactive hazard compared to a single-circuit scheme.
As a result, one submarine gets three power supply modes at once: diesel cruising, electric submerged, and constant generation from a small nuclear unit.