摘要 |
<p>The disclosure relates to a refrigeration system wherein the evaporator of the refrigeration system is placed within a vacuum system as a "Meissner" coil previously described. Optionally it may be provided with extended surface(s). The cryosurface has a single tube passage for flow of either an evaporating low temperature refrigerant fluid for cooldown and continuous cold operation, or superheated compressed refrigerant gas for adding heat during the defrost cycle. Appropriate valves select whether cold fluid or superheated refrigerant gas flows through the tube in the cryosurface. A recuperative heat exchanger and a superheating exchanger preheat, in two stages, a cold compressed refrigerant gas stream after the gas has been rectified within the system. This superheated gas stream defrosts the cryosurface, flows back through the recuperative heat exchanger where it is recooled and then is reintroduced into the cold cascade heat exchangers.</p> |