Emergency cooling system using a loop thermosyphon

Abstract

An emergency cooling system for cooling an object certainly and rapidly in case a temperature of the object is accidentally raised abnormally. A loop thermosyphon is formed by connecting an evaporating portion with a condensing portion through a vapor pipe and a return pipe in a manner to form a cyclic conduit. A condensable working fluid circulates within the loop thermosyphon to be evaporated by a heat of the cooling object at the evaporating portion, and to be condensed at the condensing portion to radiate the heat conducted from the cooling object. A switching valve is disposed on the return pipe to selectively allow the working fluid in a liquid phase to be returned from the condensing portion to the evaporating portion. Heat transfer pipes to which the heat of the cooling object is conducted are arranged in the evaporating portion. Heat transfer protrusions are formed on an inner wall of the heat transfer pipe to penetrate through dews of the working fluid, and a preheating portion to which the heat of the cooling object is conducted is formed within a portion of the return pipe connected to the heat transfer pipe.

1 . An emergency cooling system, comprising:
 a loop thermosyphon, in which an evaporating portion at which heat exchange with a cooling object takes place is connected with a condensing portion at which a heat radiation takes place through a vapor pipe and a return pipe in a manner to form a cyclic conduit;   a condensable working fluid circulating within the loop thermosyphon to be evaporated by a heat of the cooling object at the evaporating portion, and to be condensed at the condensing portion to radiate the heat conducted from the cooling object;   a switching valve that is disposed on the return pipe to selectively allow the working fluid in a liquid phase to be returned from the condensing portion to the evaporating portion;   characterized by:   a heat transfer pipe, which is arranged in the evaporating portion and to which the heat of the cooling object is conducted;   a heat transfer protrusion that is formed on an inner wall of the heat transfer pipe to penetrate through a dew of the working fluid; and   a preheating portion, which is formed within a portion of the return pipe connected to the heat transfer pipe, and to which the heat of the cooling object is conducted.   
     
     
         2 . The emergency cooling system as claimed in  claim 1 ,
 wherein the condensing portion is situated higher than the evaporating portion; and   further comprising a storage tank for holding the working fluid in the liquid phase that is connected with a lower portion of the condensing portion.   
     
     
         3 . The emergency cooling system as claimed in  claim 1 , wherein the cooling object includes a containment for holding an atomic fuel. 
     
     
         4 . The emergency cooling system as claimed in  claim 1 ,
 wherein the evaporating portion is comprised of:   an upper header pipe;   an lower header pipe; and   a plurality of the heat transfer pipes arranged in parallel with one another while being connected with the upper header pipe and the lower header pipe; and   wherein the condensing portion is comprised of:   another upper header pipe;   another lower header pipe;   a plurality of a radiating pipes arranged in parallel with one another while being connected with said another upper header pipe and said another lower header pipe; and   a plurality of radiator fins mounted on the radiating pipes to radiate the heat to the air.   
     
     
         5 . The emergency cooling system as claimed in  claim 1 , wherein the preheating portion is formed within the portion of the return pipe extending inside of the cooling object. 
     
     
         6 . The emergency cooling system as claimed in  claim 1 , wherein the preheating portion includes a meander pipe formed by bending the return pipe.