A refrigeration system includes an evaporator within which a refrigerant absorbs heat, a gas cooler/condenser within which the refrigerant rejects heat, a compressor operable to circulate the refrigerant between the evaporator and the gas cooler/condenser, a high pressure valve operable to control a pressure of the refrigerant at an outlet of the gas cooler/condenser, and a controller. The controller is configured to automatically generate a setpoint for a measured or calculated variable of the refrigeration system based on a measured temperature of the refrigerant at the outlet of the gas cooler/condenser. The setpoint is generated using a stored relationship between the measured temperature and a maximum estimated coefficient of performance (COP) that can be achieved at the measured temperature. The controller is configured to operate the high pressure valve to drive the measured or calculated variable toward the setpoint.

A dual reclaim coil with a smart control application is provided that allows the refrigerant inlet to the HVAC unit switch between the two sides of the condenser is aimed to use the high temperature and pressure of the condenser/gas cooler outlet while a CO.sub.2 refrigerant system is operating above critical point. This occurs in hot ambient conditions, when the need for heating in the space is not as great as in the wintertime and the available heat at the condenser/gas cooler's outlet is sufficient to satisfy the heating load. This also mitigates space overcooling, while increasing the CO.sub.2 transcritical system's efficiency by subcooling the refrigerant for applications involving dehumidification HVAC systems which often results in a phenomenon called overcooling during the dehumidification season.

A CO.sub.2 based system, such as a heat pump system or a refrigeration system, is disclosed. The system comprises a plurality of ejectors arranged in parallel. Each of the ejectors comprises a motive port and a suction port. Each of the ejectors has a fixed geometry. A first actuated ball valve is arranged in front of the motive port. A second actuated ball valve is arranged in front of the suction port. The system comprises a control unit arranged and configured to control the activity of the ball valves on the basis of one or more predefined criteria.

The invention relates to a refrigeration installation (1), to a method for same, and to a refrigeration installation system, for controlling the temperature of air, comprising at least one compressor (3), at least one expansion element (39) , and at least one first (5) and a second (7) heat exchanger, each of which can be operated as a condenser or a gas cooler, wherein at least one of the heat exchangers can be operated as an evaporator or at least one additional heat exchanger is provided which can be operated as an evaporator. A refrigerant line is equipped with a first valve (11) downstream of at least one compressor (3) at or downstream of a branch (9) and upstream of or at the condenser or gas cooler inlet (15) of the first heat exchanger (5), and a second valve (19) is arranged at or downstream of the condenser or gas cooler outlet (17) of the first heat exchanger (5) and upstream of or as an expansion element. The refrigeration installation (1) contains at least one valve controller (13) for the first (11) and second valve (19) with at least one first and second possible valve set-up in order to displace the refrigerant, wherein the first Valve (11) is open while the second valve (19) is closed at the same time in the first set-up and vice versa in the second set-up. The valve controller (13) comprises an automatic regulator which sets the first valve switch set-up for at least one heat exchanger (5, 7) which is not being used as a with refrigerant flowing through condenser or gas cooler at the moment when a specified refrigerant quantity is exceeded in the refrigerant circuit through which refrigerant is flowing.

A refrigerator includes a main body having a freezing chamber and a switchable chamber communicating with a refrigerating chamber through a duct, a compressor connected with a compressor suction path and a compressor discharging path, a condenser connected with the compressor discharging path and connected with a condenser discharging path, a switchable chamber evaporator, a freezing chamber evaporator connected with the switchable chamber evaporator through an evaporator connection path, a damper configured to control flow of cold air through the duct, a pair of switchable chamber capillary tubes connected with the switchable chamber evaporator, a bypass capillary tube connected with the evaporator connection path, a path switching device connected with the condenser discharging path, the pair of switchable chamber capillary tubes and the bypass capillary tube, and a controller for controlling the compressor, the damper and the path switching device.

An air conditioner is provided that may include at least one compressor that compresses a refrigerant to a high pressure; a plurality of heat exchanger that condenses the refrigerant compressed in the at least one compressor; a plurality of outdoor valves, respectively, provided at an outlet side pipe of the plurality of heat exchangers; a gas liquid separator that separates the refrigerant into gas and liquid refrigerants and supplies the gas refrigerant to the at least one compressor; and one or more bypass devices connected to the outlet side pipe of one or more of the plurality of heat exchangers and an inlet side pipe of the gas liquid separator, the one or more bypass devices controlling a flow of the liquid refrigerant. During a cooling low load operation in which a portion of the plurality of heat exchangers is operating, a liquid refrigerant loaded into a heat exchanger of the plurality of heat exchangers, which is not operated, may flow through the one or more bypass device.

A method of operating an HVAC system includes compressing a working fluid using a compressor, removing heat from the working fluid using a condenser, removing pressure from the working fluid using an expansion valve, and transferring heat between airflow contacting an outer surface of one or more coils in an evaporator and the working fluid passing through the one or more coils. The method further includes detecting a leak of the working fluid using a leak detection sensor. The method further includes transporting at least a portion of the working fluid to a storage container and storing the working fluid in the storage container.

A method of operating an HVAC system includes compressing a working fluid using a compressor, removing heat from the working fluid using a condenser, removing pressure from the working fluid using an expansion valve, and transferring heat between airflow contacting an outer surface of one or more coils in an evaporator and the working fluid passing through the one or more coils. The method further includes detecting a leak of the working fluid using a leak detection sensor. The method further includes transporting at least a portion of the working fluid to a storage container and storing the working fluid in the storage container.

A refrigeration system includes a subcooler configured to provide subcooling for a liquid refrigerant flowing through a first side of the subcooler by transferring heat from the liquid refrigerant to a gas refrigerant flowing through a second side of the subcooler. An expansion valve is located at an inlet of the second side of the subcooler and configured to control a flow of the gas refrigerant through the second side of the subcooler. A gas temperature sensor and a gas pressure sensor are configured to measure a temperature and pressure of the gas refrigerant. A liquid temperature sensor is configured to measure a temperature of the subcooled liquid refrigerant. A controller is configured to calculate a superheat of the gas refrigerant based on the measured temperature and measured pressure of the gas refrigerant and may compare the calculated superheat to a superheat threshold. If the calculated superheat is less than the superheat threshold, the controller may close the expansion valve. If the calculated superheat is equal to or greater than the superheat threshold, the controller may operate the expansion valve using a feedback control technique to drive the temperature of the subcooled liquid refrigerant to a subcooled liquid temperature setpoint.

A method of and system for heating and/or cooling a fluid, the method comprising moving the fluid through a secondary side of a heat exchanger and controlling the temperature of a primary side of the heat exchanger such that the temperature of the primary side of the heat exchanger is maintained substantially at a determined temperature interval from a reference temperature which is a function of at least one of: a temperature of an inlet to the secondary side and a temperature of an outlet of the secondary side.