Patent ID: 8191385

Claim:
An evaporator, adapted to a two-stage expansion cooling system, for receiving a high-pressure liquid working fluid, the evaporator comprising: a thermal-conductive block having a channel system therein and receiving a liquid that has been expanded in a first stage expansion device, wherein the channel system comprises: a high-pressure channel provided for the high-pressure liquid working fluid to enter the thermal-conductive block through the high-pressure channel; a low-pressure channel having a cross-sectional area smaller than that of the high-pressure channel; and a second stage expansion channel having: an input end and an output end; a length defined by the distance from the input end to the output end; and a first side and a second side opposite the first side when an axis exists throughout the length of the second stage expansion channel; wherein the input end is communicated with the high-pressure channel, the output end is communicated with the low-pressure channel and has a cross-sectional area smaller than that of the low-pressure channel, the second stage expansion channel is between the high-pressure channel and the low-pressure channel, the high-pressure liquid working fluid enters the second stage expansion channel through the input end, and a part of the high-pressure liquid working fluid flowing out of the output end expands into a saturated low-pressure liquid working fluid and enters the low-pressure channel, and wherein the high pressure channel extends around the low pressure channel on four sides, a section of the high pressure channel extends in parallel to the entire length of the second stage expansion channel at the first side, and a section of the low pressure channel extends in parallel to the entire length of the second stage expansion channel at the second side.