Thermo King Corporation

Dale T Johnson

Herman H Viegas

Roland L Roehrich

Two-sided hoe

Inline filtration unit

Water treatment system

Air conditioning and refrigeration methods and apparatus for controlling the temperature of a conditioned space to a predetermined temperature band adjacent to a predetermined set point temperature via cooling and heating cycles utilizing a supply of pressurized cryogen. A fluid flow path for the cryogen includes a heat exchanger associated with the conditioned space. A cryogen heater is connected in the active cryogen flow path during a heating cycle, and cryogen is directed through the heater and heat exchanger via at least two successive serial passes, utilizing the elevated pressure energy of the cryogen as the motive force.

Air conditioning and refrigeration systems utilizing a cryogen

A refrigeration system, which conditions the air of a conditioned space via heating and cooling cycles, includes a heat exchanger and, in a first embodiment, heat pipes. A cryogen is circulated through the heat exchanger during a cooling cycle. During a heating cycle the flow of cryogen is terminated and heat is transferred into the heat exchanger via the heat pipes. In another embodiment, the temperature of evaporation of a liquid cryogen in the heat exchanger is selected according to the desired temperature of the conditioned space, via selectable cryogen flow paths which provide different pressures and thus different evaporation temperatures. Vaporized cryogen drives a motor connected to a fan which circulates air between the conditioned space and heat exchanger. In still another embodiment, the mass flow rate of liquid cryogen is controlled as a function of the degree of superheat in evaporated cryogen exiting the heat exchanger, and as a function of a predetermined floor temperature of conditioned air discharged into the conditioned space.

Growing community of inventors

Minneapolis, MN, United States of America

Dale T Johnson