Abstract: A liquid cooling unit includes components such as first and second heat receivers, a heat exchanger, a tank and a pump in an electronic apparatus. The electronic apparatus includes a first enclosure and a second enclosure coupled to the second enclosure for relative movement. The liquid cooling unit is enclosed in the first enclosure. No component of the liquid cooling unit is enclosed in the second enclosure. The liquid cooling unit is thus incorporated in the first enclosure in a facilitated manner. This results in a reduced production cost. The liquid cooling unit can also be removed from the first enclosure in a facilitated manner.

Abstract: A portable electronic apparatus includes a first unit, a second unit, and a hinge unit. The first unit includes a first housing, a heat generating component inside the first housing, a first heat diffusing member disposed inside the first housing and diffusing heat from the heat generating component, and a heat dissipating part dissipating heat diffused by the first heat diffusing member to the outside of the first housing. The second unit includes a second housing, a second heat diffusing member disposed inside the second housing and diffusing heat inside the second housing, and a heat receiving part conducting heat from the heat dissipating part to the second heat diffusing member upon the heat receiving part being in contact with the heat dissipating part.

Abstract: An electronic apparatus 100 includes a heat-generating element 1, a heat-radiating plate 4 which is used in heat radiation of the heat-generating element, and a housing 10 which accommodates the heat-generating element and the heat-radiating plate. The heat-radiating plate is disposed between the heat-generating element and a first wall portion 10a of the housing, and a support stage 5 for forming an air layer is disposed between the heat-radiating plate and the first wall portion. Since the heat-insulating effect of the air layer prevents the heat diffused from the heat-radiating plate from being easily conducted to the first wall portion, the formation of a heat spot in the first wall portion can be avoided even when the heat-generating element which generates a large amount of heat is used.

Abstract: A heat exchanger allows establishment of first and second flat spaces, namely parallel flat spaces along a reference. The heat exchanger is inserted in a closed circulating loop for coolant. The first and second flat spaces have a cross-section larger than that of a cylindrical duct of the closed circulating loop. These flat spaces serve as a flow passage for the coolant. An increased cross-section enables a reduction in the flow speed of the coolant. The coolant is allowed to slowly flow through the first and second flat spaces. The coolant thus contacts with the first and second plates and the third and fourth plates for a longer time. The heat of the coolant is sufficiently transferred to the first and second plates and the third and fourth plates. The efficiency of heat radiation is enhanced.

Abstract: A heat exchanger allows establishment of a flat space between first and second plates. The heat exchanger is inserted in a closed circulating loop for coolant. The flat space is allowed to have a cross-section larger than that of a cylindrical duct of the closed circulating loop. The flat space serves as a flow passage. An increased cross-section enables a reduction in the flow speed of the coolant. The coolant is allowed to slowly flow through the flat space. The coolant thus contacts with the first and second plates for a longer time. The heat of the coolant is sufficiently transferred to the first and second plates. The efficiency of heat radiation is enhanced.

Abstract: A liquid cooling unit includes components such as first and second heat receivers, a heat exchanger, a tank and a pump in an electronic apparatus. The electronic apparatus includes a first enclosure and a second enclosure coupled to the second enclosure for relative movement. The liquid cooling unit is enclosed in the first enclosure. No component of the liquid cooling unit is enclosed in the second enclosure. The liquid cooling unit is thus incorporated in the first enclosure in a facilitated manner. This results in a reduced production cost. The liquid cooling unit can also be removed from the first enclosure in a facilitated manner.

Abstract: An electronic component generates heat in an electronic apparatus. The heat of the electronic component is transferred to a thermal conductive plate of a heat receiver in a liquid cooling unit. The heat is transferred to coolant from the thermal conductive plate. The temperature of the coolant rises. The heat exchanger absorbs heat of the coolant. The coolant gets cooled. The heat of the electronic component is also transferred to the printed wiring board. The heat spreads over the printed wiring board through a wiring pattern in the printed wiring board. Since the tank or/and pump is placed at a position outside the printed wiring board, the heat cannot be transferred to the tank or/and the pump. This results in prevention of rise in the temperature of the coolant in the tank or/and the pump. The efficiency of heat radiation can thus be enhanced.

Abstract: An electronic apparatus includes an enclosure enclosing a liquid cooling unit. The liquid cooling unit includes a heat receiver received on an electronic component. Heat of the electronic component is transferred to the heat receiver. The heat of the heat receiver is transferred to the coolant flowing through the flow passage of the heat receiver. The electronic component gets cooled. The coolant flows into a tank in the liquid cooling unit. The tank stores the coolant and air. The air inlet is formed in the enclosure. Fresh air is introduced into the enclosure through the air inlet. Since the tank is opposed to the air inlet, the tank is exposed to the fresh air. The heat of the coolant in the tank is thus radiated into the air. The coolant gets cooled in an efficient manner. The efficiency of heat radiation is enhanced in this manner.

Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. The thermal conductive plate serves to transfer heat to coolant in the flow passage. At least two inflow nozzles extend into the casing to have discharge openings opposed to the upstream end of the flow passage. The coolant flows into the flow passage through the inflow nozzles. At least two streams of the coolant are thus generated in the flow passage. The streams widely expand or spread in the flow passage. The coolant flows through the flow passage without stagnating. The coolant can thus absorb the heat of the thermal conductive plate in an efficient manner. This results in an efficient heat absorption of the heat receiver.

Abstract: A heat receiver includes a casing defining a flow passage on a thermal conductive plate. The thermal conductive plate is received on an electronic component. An outflow nozzle has an inflow opening at the downstream end of the flow passage at a position outside the thermal conductive plate. Since the thermal conductive plate is received on the electronic component, the outflow nozzle is connected to the flow passage at a position outside the electronic component. This results in avoidance of increase in the thickness of the casing as compared with the case where the outflow nozzle directly extends into the flow passage on the thermal conductive plate.