A dilution refrigerator is provided. The dilution refrigerator includes an outer vacuum chamber comprising at least one substantially planar surface and an opening in the at least one substantially planar surface configured to provide access to an interior of the outer vacuum chamber.

A dilution refrigerator is provided. The dilution refrigerator includes a first thermal stage configured to be cooled to a first temperature, a second thermal stage configured to be cooled to a second temperature lower than the first temperature, and a vacuum chamber housing the first thermal stage and the second thermal stage. The dilution refrigerator also includes a first suspension system configured to suspend the first thermal stage from the vacuum chamber, and a second suspension system configured to suspend the second thermal stage from the vacuum chamber independently from the first thermal stage.

A distributed refrigeration system is provided. The distributed refrigeration system comprises a pre-cooling system configured to be thermally coupled to two or more cryogenic devices and to provide a first cooling stage to the two or more cryogenic devices. The two or more cryogenic devices may be two or more of a dilution refrigerator, a low-temperature microscopy system, a .sup.3He refrigeration system, and/or a superconducting CMOS system.

A dilution refrigerator is provided. The dilution refrigerator includes a plurality of thermal stages configured to be cooled to a plurality of temperatures. A coldest thermal stage of the plurality of thermal stages is disposed above warmer thermal stages of the plurality of thermal stages such that the coldest thermal stage is positioned furthest from a floor supporting the dilution refrigerator.

An improved Bernoulli heat pump, wherein the intake section of a Venturi tube is structured so that when the refrigerant flows from the intake section into and through most of the middle (narrow) section, its flow is essentially laminar. Additionally, a second, bi-phase, component is added to the flowing gaseous refrigerant. Part of the bi-phase component evaporates, reaching super saturation, which state is maintained in the middle section, owing to the laminar flow, increasing heat absorption.

A refrigeration system includes a rotary pressure exchanger fluidly coupled to a low pressure branch and a high pressure branch. The rotary pressure exchanger is configured to receive the refrigerant at high pressure from the high pressure branch, to receive the refrigerant at low pressure from the low pressure branch, and to exchange pressure between the refrigerant at high pressure and the refrigerant at low pressure, and wherein a first exiting stream from the rotary pressure exchanger includes the refrigerant at high pressure in the supercritical state or the subcritical state and a second exiting stream from the rotary pressure exchanger includes the refrigerant at low pressure in the liquid state or the two-phase mixture of liquid and vapor.

Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

A liquid nitrogen-based cooling system features a cooling circuit and a liquid nitrogen-based heat sink. Heat absorbed by fluid flowing in the cooling circuit is subsequently absorbed by liquid nitrogen within the heat sink, which causes the liquid nitrogen to vaporize. The vaporized nitrogen is condensed back to liquid form, e.g., by means of a helium-based cryo-refrigeration system. The heat-sink includes at least a first vessel that contains the liquid nitrogen, with the cooling circuit including a series of coils passing around the first vessel in heat-exchanging contact with an exterior surface thereof so that heat can be transferred into the liquid nitrogen. The first vessel and coils may be contained within a second, outer vessel that minimizes heat transfer from the ambient environment to the fluid flowing in the cooling circuit and the liquid nitrogen within the first vessel.

A heating, ventilation, and air-conditioning (“HVAC”) system for use with a refrigerant. The HVAC system includes a compressor, a condenser, an expansion device, an evaporator, and a separator. The compressor is operable to compress the refrigerant. The condenser is positioned downstream of the compressor and operable to condense the refrigerant. The expansion device is positioned downstream of the condenser and operable to reduce a pressure of the refrigerant flowing therethrough. The evaporator is positioned downstream of the expansion device and operable to vaporize the refrigerant from the expansion device. The separator is positioned downstream of the expansion device and operable to separate the refrigerant into liquid refrigerant and gaseous refrigerant. The gaseous refrigerant from the separator and the liquid refrigerant from the separator are combined prior to being compressed by the compressor.