Efficient self cooling heat exchanger

A heat exchanger comprising:

• at least one first plate of a set of first plates each having a first channel defined therein having an inlet and an outlet, wherein the plate is divided into a heat exchange region and an expansion region, wherein the channel passes through a heat exchange region and an expansion region, and wherein the first channel has a first section in the heat exchange region, a second section in the expansion region, and a third section in the heat exchange region;
• at least one second plate of a set of second plates each having a second channel defined in the second plate, wherein the second channel is defined in the heat exchange region, and wherein the second channel is substantially parallel to the third section of the first channel in the heat exchange region, and extends the entire length of the second plate;
• wherein the first and second set of plates are stacked in an alternating arrangement;
• and
• an expansion device disposed in the second section of the first channel located in the expansion region, and the second section of the first channel traverses across the expansion region and where one end of the second section of the first channel is in fluid communication with the first section of the first channel and the other end of the second section of the first channel is in fluid communication with the third section of the first channel, wherein the expansion region is separated from the heat exchange region by a region of thermal insulation that provides a lower weighted average thermal conductivity, wherein the region of thermal insulation is a section of the plate having an open space, and, wherein the heat exchanger provides for self-cooling of the fluid in the heat exchanger.