Cooling device, cooling system, and method of cooling

A cooling system comprising:

• an electronic device;
• and
• a cooling device including:
• an inner tank configured to store a first coolant which is a liquid;
• a separation wall that is provided in the inner tank, that faces a side wall portion of the inner tank, that forms an accommodating portion in which the electronic device to be immersed in the first coolant is accommodated, that forms, at at least part of a periphery of the accommodating portion, a coolant channel through which the first coolant is to flow toward a lower side of the inner tank;
• an outer tank which is disposed outside the inner tank and through which a second coolant flows;
• a heat sink including an inner fin and an outer fin, and positioned at an upper side of the inner tank, the heat sink is configured to transfer heat from the first coolant to the second coolant;
• and
• a bottom plate that is disposed below the accommodating portion, that has an injection hole through which the first coolant having has flowed, through the coolant channel, to a region below the accommodating portion is injected toward the accommodating portion,
• the injection hole is tapered such that a diameter of the injection hole reduces from a lower surface side of the bottom plate to an upper surface side of the bottom plate,
• the inner fin has an area enlarged portion disposed in an upper portion of the inner fin,
• an upper edge portion of the separation wall has a guide plate portion inclined toward a central portion of the inner tank as the guide plate portion extends upward, and
• the area enlarged portion and the guide plate portion are opposed to one another so that a force of a flow of the first coolant is able to be further increased.

A method of cooling an electronic device using a cooling device, the method comprising:

• accommodating the electronic device in an accommodating portion formed in an inner tank of the cooling device, the electronic device being immersed in a first coolant stored in the inner tank, the accommodating portion being formed by a separation wall provided in the inner tank such that the separation wall faces a side wall portion of the inner tank;
• heating the first coolant heated from heat generated by the electronic device, the heating causing;
• an upward flow of the first coolant toward a lower side of the inner tank through a coolant channel formed at at least part of a periphery of the accommodating portion;
• a downward flow of the first coolant to transfer the heat to a second coolant flowing in an outer tank of the cooling device, the heat being transferred by a heat sink positioned at an upper side of the inner tank and including an inner fin and an outer fin;
• the first coolant that transferred the heat to flow toward a region below the accommodating portion;
• the first coolant in the region below the accommodating portion to be drawn into the accommodating portion again,
• the cooling device including a bottom plate that is disposed below the accommodating portion, that has an injection hole through which the first coolant having has flowed, through the coolant channel, to the region below the accommodating portion is injected toward the accommodating portion,
• the injection hole is tapered such that a diameter of the injection hole reduces from a lower surface side of the bottom plate to an upper surface side of the bottom plate,
• the inner fin has an area enlarged portion disposed in an upper portion of the inner fin,
• an upper edge portion of the separation wall has a guide plate portion inclined toward a central portion of the inner tank as the guide plate portion extends upward, and
• the area enlarged portion and the guide plate portion are opposed to one another so that a force of a flow of the first coolant is able to be further increased.