A method for monitoring a refrigerant charge in a vapour compression system (1) is disclosed, the vapour compression system (1) including a compressor unit (2), a heat rejecting heat exchanger (3), a high pressure expansion device (4), a receiver (5), at least one expansion device (9, 10), and at least one evaporator (11, 12) arranged in a refrigerant path. A change in net mass flow into or out of the receiver (5) and/or a change in net enthalpy flow into or out of the receiver (5) is detected, and a pressure inside the receiver (5) is monitored as a function of time, following the detected change in net mass flow and/or in net enthalpy flow. A time constant being representative for dynamics of the receiver (5) is derived, based on the monitored pressure as a function of time, and information regarding a refrigerant charge in the vapour compression system (1) is derived, based on the derived time constant.

A climate-control system can be used to heat or cool a space. The climate-control system may include first and second vessels between which refrigerant and co-fluid may be circulated. The refrigerant may be absorbed into the co-fluid within the first vessel at a first rate. The refrigerant may desorb from the co-fluid within the second vessel at a second rate. Ultrasonic energy may be used to adjust the second rate to substantially match the first rate.

Thermal management systems include an open circuit refrigeration system featuring a first receiver configured to store a gas, a second receiver configured to store a liquid refrigerant fluid, an evaporator configured to extract heat from a heat load that contacts the evaporator, and an exhaust line, where the first receiver, the second receiver, the evaporator, and the exhaust line are connected to provide a refrigerant fluid flow path.

A vapor-compression system includes a centrifugal compressor configured to increase a pressure of a refrigerant based on at least one of an activation of a device or the device being equal to or above a first threshold temperature. A fluid communication system is configured to provide, to the device, a portion of the refrigerant in a liquid state. The portion of the liquid refrigerant in a liquid state is configured to have a saturation temperature equal to or below the first temperature threshold.

A refrigerating apparatus includes a centrifugal compressor, a capacity control mechanism that controls a capacity of the compressor by changing an opening degree of the capacity control mechanism, an expansion mechanism that reduces a pressure of a refrigerant, and a controller. The controller calculates an opening degree of the expansion mechanism using compressor capacity as one of a plurality of indices of change in load. The compressor capacity is obtained from a current rotation number of the compressor, an opening degree of the capacity control mechanism, and a divergence rate of a current operation head from a surge region.

A refrigeration system has: (a) a fluid tight circulation loop including a compressor, a condenser and an evaporator, the evaporator having at least three evaporator zones, each evaporator zone having an inlet port, the circulation loop being further configured to measure the condition of the refrigerant with a refrigerant condition sensor disposed within the evaporator upstream of the evaporator outlet port; and control the flow of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator, and (b) a controller for controlling the flow rate of refrigerant to the evaporator based upon the measured condition of the refrigerant within the evaporator upstream of the evaporator outlet port.

A control device and method for preventing the start and stop of heat source machines from being frequently repeated. The control device determining whether or not basic conditions for decreasing the number of machines are satisfied when the number of currently operating machines is increased by one is determined if a current operational status satisfies basic conditions for increasing the number of machines, and one heat source machine is started if it is determined that the basic conditions for decreasing the number of machines are not satisfied, and determining whether or not the basic conditions for increasing the number of machines are satisfied when the number of currently operating machines is decreased by one are satisfied if a current operational status satisfies the basic conditions for decreasing the number of machines, and one heat source machine is stopped if it is determined that the basic conditions for increasing the number of machines are not satisfied.

Systems, devices, and methods are presented that include an expansion valve having a pin operable to regulate a primary flow of refrigerant through a flow orifice. A flange is coupled to the pin and is configured to regulate a bleed flow of refrigerant through a bleed orifice. The flange moves cooperatively with the pin, thereby enabling the bleed flow of refrigerant to vary in coordination with the primary flow of refrigerant. When the pin occludes the flow orifice, the flange forms a predetermined gap that allows a non-zero bleed flow when the primary flow of refrigerant is substantially zero. The bleed flow of refrigerant therefore flows persistently through the expansion valve during operation. Other systems, tools and methods are presented.

There is disclosed an air-conditioning apparatus for vehicle which is capable of selecting an appropriate operation mode while inhibiting the operation mode from being unnecessarily changed, and achieving rapid and stable vehicle interior air conditioning. A controller has respective operation modes of a heating mode, a dehumidifying and heating mode, a dehumidifying and cooling mode, and a cooling mode, and selects and executes these operation modes. The controller has a dehumidifying and heating mode maximum radiator temperature MAP and a dehumidifying and cooling mode maximum radiator temperature MAP. The controller selects an operation mode in which a radiator target temperature TCO is achievable by heat radiation in a radiator 4 with reference to each MAP, on startup or at a time of change of the operation mode.

The present disclosure relates to a method for controlling a level of superheat during a pump mode of operation of a refrigeration system, wherein the refrigeration system can operate in either the pump mode or a compressor mode, and has an electronically controlled expansion valve (EEV). A controller obtains a stored, predetermined pump differential pressure range able to be produced by a pump of the system. The controller also obtains a stored, predetermined superheat range, and detects a superheat level. When the detected superheat level is outside of the superheat temperature range, the controller commands adjusting at least one of the EEV and a speed of the pump based on whether the detected superheat level is above or below the superheat range, and whether a current pump differential pressure is above or below the predetermined pump differential pressure range.