Cooling apparatus and method

1. A cooling apparatus comprising:

a base plate for receiving a heat load from one or more electric components,

an evaporator with a first surface in thermal contact with a surface of the base plate for transferring said heat load into a first fluid in the evaporator in an operating state of the cooling apparatus, wherein the evaporator comprises a porous structure having capillary pores,

a condenser for receiving the first fluid from a first end of the evaporator and for dissipating heat from the first fluid,

a compensation chamber extending along a second surface of the evaporator, the compensation chamber receiving the first fluid from the condenser such that pores opening up into the second surface of the evaporator are provided with the first fluid, and

a chamber in fluid communication with the first end of the evaporator and with a first end of the condenser for passing the first fluid from the evaporator to the condenser, the chamber being delimited by a housing, the evaporator and the condenser,

wherein the cooling apparatus is a capillary loop heat pipe,

wherein the first surface and the second surface of the evaporator are substantially flat and opposite from each other,

wherein the porous structure of the evaporator is a porous aluminum structure having the capillary pores and evaporator channels extending through the evaporator between a second end and the first end of the evaporator, the evaporator channels being larger in cross-sectional size than the capillary pores,

wherein the evaporator channels are embedded in the evaporator at a location between the first surface and the second surface and arranged at different depths between the first surface and the second surface, such that each of the different depths includes a plurality of evaporator channels, and

wherein a cross-sectional flow area of the chamber is of a similar size or larger than a combined cross-sectional flow area of all the evaporator channels.

2. The cooling apparatus according to claim 1 , wherein the apparatus comprises a flow channel for a second fluid which is in thermal contact with the condenser for receiving heat dissipated from the first fluid.

3. The cooling apparatus according to claim 2 , wherein the second fluid is air and the flow channel is provided with fins for dissipating heat into air flowing through the flow channel.

4. The cooling apparatus according to claim 1 , wherein the condenser is provided with assemblies comprising a pair of plates with spacer elements separating the plates from each other in order to provide condenser channels which are limited by the plates and the spacer elements.

5. The cooling apparatus according to claim 1 , wherein the size of the pores is 1 to 100 μm and a width of the evaporator channels is 0.5 to 5 mm.

6. The cooling apparatus according to claim 1 , wherein the size of the pores varies between the first end of the evaporator and the second end of the evaporator.

7. The cooling apparatus according to claim 6 , wherein the size of the pores proximate to the first end is smaller than the size of the pores proximate to the second end.

8. The cooling apparatus according to claim 6 , wherein the size of the pores proximate to the first end is larger than the size of the pores proximate to the second end.

9. The cooling apparatus according to claim 1 , which further comprises a power module comprising one or more electric components thermally connected to the base plate.

10. The cooling apparatus according to claim 1 , wherein the evaporator is a monolithic porous structure between the first surface and the second surface.

11. A method for manufacturing a cooling apparatus, the method comprises:

producing an evaporator having a capillary porous structure with pores and a plurality of evaporator channels, the evaporator channels being larger in cross-sectional size than the pores, the evaporator channels being embedded in the evaporator at a location between a first surface and a second surface of the evaporator, the first surface and the second surface being substantially flat and opposite from each other, the evaporator channels being arranged at different depths between the first surface and the second surface, such that each of the different depths includes a plurality of evaporator channels extending through the evaporator between a second end and a first end of the evaporator by utilizing a 3D printer,

providing a compensation chamber to extend along a second surface of the evaporator for supplying a first fluid to the evaporator via the pores opening up into the second surface,

providing fluid paths from said evaporator and said compensation chamber to a first end and respectively second end of a condenser for passing the first fluid evaporated from the evaporator to the condenser and for passing the first fluid condensed from the condenser to the compensation chamber in an operating state of the cooling apparatus, and

providing a chamber in fluid communication with the first end of the evaporator and with a first end of the condenser for passing the first fluid from the evaporator to the condenser, a cross-sectional flow area of the chamber being of similar size or larger than the combined cross-sectional flow area of all the evaporator channels, and said chamber is delimited by a housing, the evaporator and the condenser.

12. The method according to claim 11 , wherein the components of the cooling apparatus are mechanically connected to each other during a single brazing step.

13. The method according to claim 11 , wherein the evaporator is a monolithic porous structure between the first surface and the second surface.