Cooling apparatus using boiling and condensing refrigerant

A cooling apparatus using boiling and condensing refrigerant for cooling an exothermic device, comprising:

• a refrigerant tank for storing liquid refrigerant which is partially boiled and vaporized into gaseous refrigerant by heat transmitted from the exothermic device;
• and
• a radiator communicated to said refrigerant tank to receive said gaseous refrigerant from said refrigerant tank, for radiating heat of said gaseous refrigerant to an outside of said radiator to condense said gaseous refrigerant, and for returning said condensed refrigerant to said refrigerant tank, wherein;
• said refrigerant tank includes a refrigerant chamber in which said liquid refrigerant is vaporized by receiving heat transmitted from the exothermic device, a condensed liquid passage in which said condensed refrigerant flows, a heat insulating passage provided between said refrigerant chamber and said condensed liquid passage for reducing heat transmission from said refrigerant chamber to said condensed liquid passage, and a communication passage provided at a bottom of said refrigerant tank for communicating said refrigerant chamber, said condensed liquid passage, and said heat insulating passage;
• and
• said refrigerant tank includes a vapor reverse flow reducing member provided between said heat insulating passage and said communication passage for reducing a flow of said gaseous refrigerant from said heat insulating passage to said communication passage.