Cooling system for server

1. A cooling system for a server, comprising:

a casing, comprising a tank and a cover, wherein the tank has an accommodation space, the cover is movably mounted on the tank, the cover comprises an outer portion and an inner portion, and the cover covers the accommodation space so as to form an airtight space with the tank;

a first heat dissipation device, mounted on the cover and located within the airtight space of the casing; and

at least one second heat dissipation device, located at a periphery of the inner portion and a periphery of the first heat dissipation device.

2. The cooling system according to claim 1 , wherein the tank comprises a first accommodation portion and a second accommodation portion, the first accommodation portion surrounds a liquid storage area of the accommodation space and an opening is connected to the liquid storage area, the second accommodation portion is connected to the first accommodation portion and surrounds a vapor storage area of the accommodation space, the vapor storage area is connected to the liquid storage area via the opening, a length and a width of the second accommodation portion are larger than a length and a width of the first accommodation portion, the cover is movably mounted the second accommodation space portion of the tank, the at least one second heat dissipation device is located in the vapor storage area, and an orthogonal projection of the at least one second heat dissipation device on a plane where the opening is located is located outside the opening.

3. The cooling system according to claim 2 , wherein the outer portion is connected to the periphery of the inner portion, the inner portion protrudes from the outer portion, the inner portion is located closer to the first accommodation portion than the outer portion, the at least one second heat dissipation device is located at a side of the outer portion close to the first accommodation portion.

4. The cooling system according to claim 3 , wherein the quantity of the at least one second heat dissipation device is plural.

5. The cooling system according to claim 4 , wherein every adjacent two of the second heat dissipation devices are connected to each other.

6. The cooling system according to claim 4 , wherein the cover is pivotably disposed on the tank.

7. The cooling system according to claim 6 , wherein the cover is pivotable between a closed position and an opened position with respect to the tank; when the cover is in the closed position, an orthogonal projection of the first heat dissipation device on the plane where the opening is located substantially overlaps with the opening; when the cover is in the opened position, the orthogonal projection of the first heat dissipation device on the plane where the opening is located is located outside the opening, and the orthogonal projection of the first heat dissipation device and the orthogonal projections of the second heat dissipation devices on the plane where the opening is located surround the opening together.

8. The cooling system according to claim 6 , further comprising a hinge assembly, wherein the hinge assembly comprising a first hinge component and a second hinge component, the first hinge component is fixed on the tank, the second hinge component is fixed on the cover, the second hinge component is pivotably disposed on the first hinge component via a pivot, such that the cover is pivotable with respect to the tank.

9. The cooling system according to claim 1 , wherein the cover comprises a transportation port, the transportation port is connected to the first heat dissipation device.

10. The cooling system according to claim 1 , wherein the cover is pivotably disposed on the tank.