High temperature cooling system and method

#The present invention relates in general to a method and related apparatus for cooling a heat source, and in particular to a method which employs a circulating liquid metal coolant composition as a heat dissipation medium within a closed-loop containment vessel of a cooling system. The interior surface of the vessel is covered with a protective coating such as an oxide layer to prevent an untoward reaction between the vessel and the liquid metal composition.

#Traditional heat sources that require proactive heat removal include process systems such as those exemplified by internal-combustion engines, gasoline-driven and coal-driven electricity generators, nuclear reactors, accelerator-driven radioactive waste transmutators, spalation sources used in nuclear accelerators, and the like. Efficient cooling systems have been developed that utilize liquid metal compositions as heat absorbers, and such liquid metal systems are usually found in association with nuclear reactors and related equipment that generate significant heat during operation. The desirability of liquid metal compositions for heat removal is attributed to liquid metal properties that include high thermal conductivity, thermal stability, low neutron capture cross section (resulting in relatively uniform power distributions), self shielding from reactor gamma-rays, high boiling points (enabling in low-pressure operation at high temperatures), and high capacities for heat absorption, storage, and dissipation.

#Liquid metal cooling systems operate in much the same manner as do the aqueous-coolant cooling systems for conventional internal combustion engines found in vehicles. Thus, in conventional liquid metal cooling systems, the liquid metal is confined in a closed-loop system which includes a heat source portion and a heat exchanger portion. Operationally, the heat source portion comes into thermal communication with a heat source (e.g. a nuclear reactor) and heat therefrom transfers into the liquid metal composition as it travels through the heat source portion of the closed-loop. As a result, the temperature of the liquid metal composition increases as the composition passes through the heat source portion. After absorption of heat, the liquid metal composition continues its travel within the closed-loop for ultimate arrival at the heat exchanger portion where the absorbed heat is dissipated and the composition continues in the closed-loop for return to the heat source portion as the circuit repeats.

#An illustrative and presently preferred embodiment of the invention is shown in the accompanying drawing in which:

#FIG. 1 is a schematic representation of a liquid metal cooling system provided with an oxide layer management system;

#FIG. 2 is a schematic representation of the oxide layer management system of FIG. 1;

#Referring to FIG. 1, a cooling system 100 with an oxide layer deposition system is illustrated for preventing chemical interaction between a molten metal cooling composition 176 and the system 100. As shown, the cooling system 100 is a liquid metal cooling system for cooling a heat source (e.g. a process system 110). The cooling system 100 is provided with a containment vessel in the form of, for example, a containment pipe 200, a heat exchanger 130, a tuyere tube 150, a gas/molten-metal separator 180, and a molten metal cooling composition 176. The details of each of the aforementioned exemplary components will now be detailed herein.

#The heat producing process system 110 is provided with a process system inlet 112, a process system outlet 114, and a heat-exchanging surface 116. The heat-exchanging surface 116 is located between the process system inlet 112 and the process system outlet 114. The heat-exchanging surface 116 is provided for transferring heat “q1” from the process system 110 into the molten metal cooling composition 176 via thermal communication therewith. One non-limiting example of the heat exchanging surface 116 is a flow path or tubular conduit wrapped circumferentially around a cylindrical reaction chamber, although any one of a variety of heat exchanging devices may be employed as those skilled in the art may appreciate upon reading the present disclosure. The process system 110 can involve a variety of different systems that produce heat (e.g. nuclear reactors, accelerator driven radioactive waste transmutators, spalation sources used in accelerators, and other comparable devices). The process system 110 generates heat as a product of the process (e.g. nuclear reaction, burning, resistance, or the like). The heat produced by the process system 110 typically needs to be removed in order to ensure optimized performance, to minimize failure, or to produce power (e.g. steam for a nuclear power plant).

#The heat exchanger 130 is provided with a heat exchanger inlet 132, a heat exchanger outlet 134, and a heat-exchanging surface 136. The heat-exchanging surface 136 is located between the heat exchanger inlet 132 and the heat exchanger outlet 134. The heat exchanging surface 136 is used to remove heat “q2” from the molten metal cooling composition 176 traveling through the heat exchanger 130 via thermal communication therewith. The heat exchanger 130 can involve a variety of conventional heat exchanging systems including but not limited to liquid baths, convection cooling fins, evaporative cooling towers, refrigeration devices, or the like.