Loop heat pipe

A loop heat pipe comprising:

• an evaporator configured to vaporize a working fluid;
• a condenser configured to liquefy the working fluid;
• a liquid line connecting the evaporator and the condenser;
• and
• a vapor line connecting the evaporator and the condenser;
• wherein
• the evaporator, the condenser, the liquid line, and the vapor line form a loop-shaped flow path through which the working fluid flows;
• the vapor line is formed by stacking a lowermost metallic layer, an uppermost metallic layer, and an intermediate layer set provided between the uppermost metallic layer and the lowermost metallic layer, the intermediate layer set being formed of a plurality of metallic layers including a first metallic layer and a second metallic layer provided on the first metallic layer;
• the first metallic layer includes
• a pair of first walls forming walls of the vapor line,
• a first opening penetrating the first metallic layer, and
• a second opening penetrating the first metallic layer;
• the second metallic layer includes
• a pair of second walls forming walls of the vapor line,
• a third opening penetrating the second metallic layer, and
• a fourth opening penetrating the second metallic layer;
• the first opening and the third opening are disposed to coincide with each other in a plan view;
• and
• the first opening, the second opening, the third opening, and the fourth opening form a portion of the loop-shaped flow path connecting the evaporator with the condenser.

A loop heat pipe comprising:

• an evaporator configured to vaporize a working fluid;
• a condenser configured to liquefy the working fluid;
• a liquid line connecting the evaporator and the condenser;
• and
• a vapor line connecting the evaporator and the condenser;
• wherein
• the evaporator, the condenser, the liquid line, and the vapor line form a loop-shaped flow path through which the working fluid flows;
• the evaporator is formed by stacking a lowermost metallic layer, an uppermost metallic layer, and an intermediate layer set provided between the uppermost metallic layer and the lowermost metallic layer, the intermediate layer set being formed of a plurality of metallic layers including a first metallic layer and a second metallic layer provided on the first metallic layer;
• the first metallic layer includes
• a pair of first walls forming walls of the evaporator, the condenser, the liquid line, and the vapor line,
• a first opening penetrating the first metallic layer, and
• a second opening penetrating the first metallic layer;
• the second metallic layer includes
• a pair of second walls forming walls of the evaporator, the condenser, the liquid line, and the vapor line,
• a third opening penetrating the second metallic layer, and
• fourth opening penetrating the second metallic layer;
• the first opening and the third opening are disposed to coincide with each other in a plan view;
• the second opening and the fourth opening are disposed to partially overlap each other in a plan view, such that the second opening is in communication with the fourth opening;
• the first opening and the third opening form a first portion of the flow path;
• the second opening and the fourth opening form a second portion of the flow path;
• and
• the communication between the second opening and the fourth opening is narrower than the communication between the first opening and the third opening.