1. Technical Field
The present invention relates to a cooling system and, in particular, to a rotatable-type liquid-cooled heat sink and a disposition method for the same.
2. Related Art
With the advancement of semiconductor technology, an electronic component has a smaller size and a greater radiation amount, thus causing difficulty in heat dissipation. The conventional heat sinks, such as heat dissipation fins, heat pipes, or fans, are inadequate. Therefore, liquid-cooled heat sinks were born which use pipes with coolant and push the coolant in the pipes by a pump to achieve heat sink circulations. The liquid-cooled heat sinks are becoming more widely used and more prevalent.
However, when the liquid-cooled heat sinks are applied to a desktop computer and etc., after the liquid-cooled heat sinks are installed in electronic heat radiation components of computers, such as CPU or GPU, their dispositions are not changed along with relocations of the computer. For example, they are not rotated with respect to the computer. However, if they are applied to apparatuses like a projector which can be laid on a desk or be hung from the ceiling, because the projector often needs to rotate by any angle to complete its installation according to the layout of the environment, or needs to operate in situations different from being laid on the desk, there are changes to the inside conditions of the liquid-cooled heat sink installed in the projector, causing the liquid-cooled heat sink to operate differently from its original design or causing unexpected problems in use.
The present liquid-cooled heat sink mainly includes a pump, a liquid storage tank, a liquid-cooled head, a cooling module, and a pipe portion connected to each of the aforesaid elements. The liquid storage tank provides coolant, and the pump moves the coolant to flow in the pipe portion, so that the coolant can bring away the heat which is absorbed by the liquid-cooled head contacting a heat source. Then, the coolant is cooled by passing through the cooling module. Such circulations can achieve liquid-cooled radiation effects. However, since the coolant has a thermal expansion feature, the coolant expands by heat under a high temperature operation environment. Therefore, usually a pressure reducing valve is incorporated into the design to overcome such a problem. But, in aforesaid situation that the liquid-cooled heat sink is applied to the projector or other apparatuses that may need to be rotated, the pressure reducing valve cannot function properly due to a liquid leakage problem resulted from rotating the projector or other apparatuses. To solve the problem, some space as a buffer space is reserved in the liquid-cooled heat sink for the expansion of the coolant when filling the coolant in the liquid-cooled heat sink.
Although the above-mentioned method solves the coolant expansion problem resulted from the improper functioning of the pressure reducing valve, as time goes by, some of the coolant of the liquid-cooled heat sink is evaporated due to heat when passing through the liquid-cooled head, thus inevitably leaving unnecessary air inside the liquid-cooled heat sink. If the unnecessary air is accumulated in the pump (e.g. when the pump is in a highest position in the whole liquid-cooled heat sink), the air in excess of an expected amount in the pump results in idling of the pump, so the pump can only move less coolant, thus affecting the radiation efficiency. The idling of the pump even results in malfunction of the pump, so the heat radiation requirement of the apparatus cannot be met, and also the apparatus malfunctions due to overheating.
In view of the foregoing, the inventor made various studies to improve the above-mentioned problems to realize the improvements, on the basis of which the present invention is accomplished.