Refrigeration apparatus and method

This is a refrigeration device that uses a cooling element to chill a fluid reservoir. The reservoir has a head region and a body region, both containing a cooling fluid like water. The cooling element cools the head region, which then cools the body region. A payload is cooled directly by the fluid in the body region, with the cold store and payload positioned on opposite sides of the reservoir. The design aims to keep the payload at a stable temperature, specifically the critical temperature of the cooling fluid, like 4 degrees Celsius for water.