A rotary compressor system includes a compressor housing that includes a compressor motor that draws in fluid from a suction side. The fluid is compressed within a compression chamber and discharged through a discharge side. The compression chamber is disposed between the suction side and the discharge side. An overload-protection switch is electrically coupled in series with the compressor motor and is adapted to cut power to the compressor motor responsive to an overload event. A solenoid valve is fluidly coupled between the compression chamber and a location upstream of the suction side and is electrically coupled in series with the overload-protection switch. An interruption of electrical current to the compressor motor also interrupts electrical current to the solenoid valve, which opens the solenoid valve to equalize pressure between the suction side and the discharge side.

A method for controlling a vapour compression system having an ejector includes, in the case that a pressure difference between a pressure prevailing in the receiver and a pressure of refrigerant leaving the evaporator decreases below a first lower threshold value, the pressure of refrigerant leaving the heat rejecting heat exchanger is kept at a level which is slightly higher than the pressure level providing optimal coefficient of performance.

A heat exchange system including a first heat exchanger and a second heat exchanger arranged in parallel with the first heat exchanger with respect to flow of refrigerant through the heat exchange system. A flow control assembly is at an outlet of the first heat exchanger. The flow control assembly is configured to allow refrigerant to flow out of the first heat exchanger through the flow control assembly, and restrict refrigerant that has passed through the second heat exchanger from flowing through the flow control assembly and into the first heat exchanger.

An apparatus includes a microchannel heat exchanger, a load, a compressor, and a controller. The microchannel heat exchanger removes heat from a refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The compressor compresses the refrigerant from the load. The controller determines a discharge temperature of the refrigerant at the compressor and predicts a saturation temperature of the refrigerant between the compressor and the microchannel heat exchanger. The controller also determines a discharge superheat by subtracting the saturation temperature from the discharge temperature and triggers an alarm if the discharge superheat is below a threshold temperature.

A refrigeration system includes a free cooling system having an air-cooled heat exchanger, where the air-cooled heat exchanger includes a fan configured to move air over coils of the air-cooled heat exchanger to remove heat from a coolant flowing through the air-cooled heat exchanger, and a mechanical cooling system with a refrigerant loop that includes an evaporator, a compressor, and a condenser disposed along the refrigerant loop, where the compressor is configured to circulate a refrigerant through the refrigerant loop, and wherein the evaporator is configured to receive the coolant and transfer heat from the coolant to the refrigerant. The refrigeration system also includes a controller configured to adjust a fan speed of the fan up to a threshold fan speed, to initiate operation of the compressor when the fan speed reaches the threshold fan speed, wherein the fan speed and a compressor speed of the compressor are based at least on an ambient air temperature and a cooling load demand.

An air-conditioning apparatus including a compressor incorporating an electric motor; a temperature sensor configured to detect indoor temperature; a drive circuit configured to drive the electric motor; a connection switching device configured to switch connection of stator windings of the electric motor between a first connection state and a second connection state higher in line-to-line voltage than the first connection state; and a controller configured to enter thermo-off when the indoor temperature reaches a target temperature or a correction temperature set based on the target temperature and cause the connection switching device to switch connection, the thermo-off being entered by stopping the compressor via the drive circuit. When a thermo-off count reaches a reference count with the electric motor being in the first connection state, the controller causes the connection switching device to switch connection from the first connection state to the second connection state.

A heat pump arrangement includes a heat pump device, an evaporator cycle interface for inputting liquid to be cooled into the heat pump device and for outputting cooled liquid out of the heat pump device, a condenser cycle interface for inputting liquid to be heated into the heat pump device and for outputting heated liquid out of the heat pump device, a controllable heat exchanger for controllably coupling the evaporator cycle interface and the condenser cycle interface, and a control for controlling the controllable heat exchanger in dependence on an evaporator cycle temperature in the evaporator cycle interface or a condenser cycle temperature in the condenser cycle interface.

A method and system for optimizing the operation of a geo-exchange system, by generating predictive models pertaining to energy demand and energy capacity for a particular building or district, based on data from sensors associated with components of a district geo-exchange system, historical and real-time operational data associated with district modules, including weather forecast data and current weather conditions.

An absorption cooling system that includes a plurality of solar collectors, a generator containing a dilute absorbent-refrigerant solution, a condenser, an evaporator, an absorber, a heat exchanger located between the generator and the absorber, first, second, and third storage tanks, a first temperature control valve located between the solar collectors and the first storage tank, a second temperature control valve located between the first storage tank and the generator, and a plurality of additional valves, wherein the first temperature control valve and the second temperature control valve are configured to regulate a flow of a heating fluid into the generator by automatically toggling between an open mode or a closed mode in response to a controller signal indicating a presence or an absence of a set point of a solid absorbent content in the dilute absorbent-refrigerant solution of the generator.

An absorption cooling system that includes a plurality of solar collectors, a generator containing a dilute absorbent-refrigerant solution, a condenser, an evaporator, an absorber, a heat exchanger located between the generator and the absorber, first, second, and third storage tanks, a first temperature control valve located between the solar collectors and the first storage tank, a second temperature control valve located between the first storage tank and the generator, and a plurality of additional valves, wherein the first temperature control valve and the second temperature control valve are configured to regulate a flow of a heating fluid into the generator by automatically toggling between an open mode or a closed mode in response to a controller signal indicating a presence or an absence of a set point of a solid absorbent content in the dilute absorbent-refrigerant solution of the generator.