A process of transferring heat from a first relatively cold medium to a second relatively hot medium features rotating a contained amount of a compressible fluid about an axis of rotation, thus generating a radial temperature gradient in the fluid, and heating the second medium by the fluid in a section of the fluid relatively far from the axis of rotation. An apparatus for carrying out the process includes a gastight drum rotatably mounted in a frame, and a first heat exchanger mounted inside the drum relatively far from the axis of rotation of the drum.

Rotary heat exchangers can include a ride-along compressor, at least a portion of which can be rotated along with the heat exchanger. By rotating at least a portion of the compressor along with the heat exchanger, a sealed fluid circuit containing a two-phase working fluid can be provided. A rotary heat pump or heat engine can include an evaporator and a condenser in the form of back-to-back centrifugal fans. The centrifugal fan blades or other portions of the evaporator and condenser may include internal cavities where the working fluid undergoes a phase change.

Rotary heat exchangers can include a ride-along compressor, at least a portion of which can be rotated along with the heat exchanger. By rotating at least a portion of the compressor along with the heat exchanger, a sealed fluid circuit containing a two-phase working fluid can be provided. A rotary heat pump or heat engine can include an evaporator and a condenser in the form of back-to-back centrifugal fans. The centrifugal fan blades or other portions of the evaporator and condenser may include internal cavities where the working fluid undergoes a phase change.

A heating, ventilation, and/or air conditioning (HVAC) system includes a mobile air conditioning unit configured to separately dock with each docking station of a plurality of docking stations. The mobile air conditioning unit includes a refrigerant circuit configured to condition an airflow to produce a conditioned airflow and a transportation system configured to autonomously relocate the mobile air conditioning unit.

A heating, ventilation, and/or air conditioning (HVAC) system includes a mobile air conditioning unit configured to separately dock with each docking station of a plurality of docking stations. The mobile air conditioning unit includes a refrigerant circuit configured to condition an airflow to produce a conditioned airflow and a transportation system configured to autonomously relocate the mobile air conditioning unit.

A device includes at least one volume that comprises a liquid quantity of a liquid and a partial volume with a working medium. The device further includes multiple volume limiting elements which limit the at least one volume and which are configured such that one or more passages allow outflow of a maximum of a predetermined partial quantity of the liquid quantity during one or more of a compression period, an expansion period, or a displacement period. The liquid quantity performs a rotation about an axis of rotation. The multiple volume limiting elements are configured to prevent an annular flow of the liquid quantity about the axis of rotation. The at least one volume is changeable in terms of its overall size by displacement of at least one of the volume limiting elements.

A system for measuring oil circulation ratio in a vapor-compression refrigeration system (VCRS) is provided. The system may include an oil separator configured to receive the refrigerant and oil flow from the low-pressure line of the VCRS and output a oil flow and a refrigerant flow. The system may further include an oil collector configured to receive the separated oil flow provided by the oil separator. A valve may control an oil flow from the oil collector to the low-pressure line. A level sensor may measure oil level in the oil collector. The system may close, in response to the oil being at or less than a first level, the valve to collect oil in the oil collector. The system may open, in response to the oil being at or greater than a second level, the valve to release oil from the oil collector to the low-pressure line.

An evaporator coil and housing system is sometimes used in commercial applications wherein refrigeration occurs in confined and harsh environments. The disclosed evaporator coils are energy efficient, configured for installation in areas typically not suited for evaporator coil insulation, and made to withstand acids and other contaminants of spilled food stuffs. The fan motors are also made to withstand contaminates often found in commercial food environments. The various housing assemblies allow for air flow in a plethora of directions to comport with the most constrained and difficult applications. Multiple blow directions may be configured and individual blow patterns may be configured in a cone shape for maximum efficiency.

An evaporator coil and housing system is sometimes used in commercial applications wherein refrigeration occurs in confined and harsh environments. The disclosed evaporator coils are energy efficient, configured for installation in areas typically not suited for evaporator coil insulation, and made to withstand acids and other contaminants of spilled food stuffs. The fan motors are also made to withstand contaminates often found in commercial food environments. The various housing assemblies allow for air flow in a plethora of directions to comport with the most constrained and difficult applications. Multiple blow directions may be configured and individual blow patterns may be configured in a cone shape for maximum efficiency.

A refrigerator includes a main body that has a storage chamber and a drying chamber; a thermoelectric module that includes a heat absorber and a heat dissipater; a cooling fan that circulates air in the storage chamber to the heat absorber and the storage chamber; a heat-dissipating fan that blows air to the heat dissipater; an air guide that has a passage for guiding air heated by the heat dissipater to the drying chamber; a heater that is disposed in the passage; and a damper that controls a flow of air in the passage between the heat-dissipating fan and the heater. Heat of the heat dissipater transfers to the drying chamber through the passage of the air guide and the damper, thereby being able to dry an object to be dried.