Systems and methods for disrupting a flow of refrigerant within a heat exchanger assembly. One embodiment provides a method that includes receiving, with a controller, a first signal from a first sensor, the first signal indicative of a pressure of the refrigerant flowing through the heat exchanger. The method includes setting, with the controller, an operating frequency of a valve based on the first signal. The operating frequency includes a rate at which the valve actuates between a first valve position that sets a first refrigerant flow rate through the heat exchanger and a second valve position that sets a second refrigerant flow rate through the heat exchanger. The method includes controlling, with the controller, operation of a solenoid to actuate the valve at the operating frequency.

A refrigeration system includes a compressor; a condenser; an expansion valve having a body with an expansion valve inlet and an expansion valve outlet; an evaporator all arranged in a refrigeration circuit; and a controller. The expansion valve body has a pathway comprising an inlet body capillary tube flow-connected to the expansion valve inlet, and an outlet body capillary tube flow-connected to the expansion valve outlet. The expansion valve comprises a solenoid operated valve element that is selectively positionable between the inlet body capillary tube outlet and the outlet body capillary tube inlet. The controller digitally controls the valve element to position the valve element either to allow flow through the pathway in an open position or to block flow through the pathway in a closed position.

A refrigeration system includes a compressor; a condenser; an expansion valve having a body with an expansion valve inlet and an expansion valve outlet; an evaporator all arranged in a refrigeration circuit; and a controller. The expansion valve body has a pathway comprising an inlet body capillary tube flow-connected to the expansion valve inlet, and an outlet body capillary tube flow-connected to the expansion valve outlet. The expansion valve comprises a solenoid operated valve element that is selectively positionable between the inlet body capillary tube outlet and the outlet body capillary tube inlet. The controller digitally controls the valve element to position the valve element either to allow flow through the pathway in an open position or to block flow through the pathway in a closed position.

The invention relates to a refrigerant for a cooling device (10) comprising a cooling circuit (11) comprising at least one heat exchanger (12), the refrigerant undergoing a phase transition in the heat exchanger, the refrigerant being a refrigerant mixture composed of a fraction of carbon dioxide (CO.sub.2), a fraction of 1,1-difluoroethene and a fraction of at least one other component, wherein the fraction of carbon dioxide in the refrigerant mixture is 45 to 90 mole percent, the fraction of 1,1-difluoroethene being 5 to 40 mole percent.

A refrigerant cycle of the present invention includes including an outdoor unit, a plurality of indoor units, and a controller for controlling the refrigeration cycle using at least one EEV. The controller comprises a velocity PID component executing a velocity PID control using pulse number for driving an EEV, three-state controller determining a driving state of the EEV and generating pulse commands designating the driving state, and a state machine driving the EEV depending on the pulse commands generated by the three-state controller.

Systems and methods for disrupting a flow of refrigerant within a heat exchanger assembly. One embodiment provides a method that includes receiving, with a controller, a first signal from a first sensor, the first signal indicative of a pressure of the refrigerant flowing through the heat exchanger. The method includes setting, with the controller, an operating frequency of a valve based on the first signal. The operating frequency includes a rate at which the valve actuates between a first valve position that sets a first refrigerant flow rate through the heat exchanger and a second valve position that sets a second refrigerant flow rate through the heat exchanger. The method includes controlling, with the controller, operation of a solenoid to actuate the valve at the operating frequency.

Systems and methods for disrupting a flow of refrigerant within a heat exchanger assembly. One embodiment provides a method that includes receiving, with a controller, a first signal from a first sensor, the first signal indicative of a pressure of the refrigerant flowing through the heat exchanger. The method includes setting, with the controller, an operating frequency of a valve based on the first signal. The operating frequency includes a rate at which the valve actuates between a first valve position that sets a first refrigerant flow rate through the heat exchanger and a second valve position that sets a second refrigerant flow rate through the heat exchanger. The method includes controlling, with the controller, operation of a solenoid to actuate the valve at the operating frequency.

A refrigeration system includes a compressor; a condenser; an expansion valve having a body with an expansion valve inlet and an expansion valve outlet; an evaporator all arranged in a refrigeration circuit; and a controller. The expansion valve body has a pathway comprising an inlet body capillary tube flow-connected to the expansion valve inlet, and an outlet body capillary tube flow-connected to the expansion valve outlet. The expansion valve comprises a solenoid operated valve element that is selectively positionable between the inlet body capillary tube outlet and the outlet body capillary tube inlet. The controller digitally controls the valve element to position the valve element either to allow flow through the pathway in an open position or to block flow through the pathway in a closed position.

Valve (1), in particular expansion valve, is described including a valve element driven by an actuator and being arranged in a valve housing arrangement (4, 5, 15), wherein the valve housing arrangement (4, 5, 15) includes a housing (4), a tube (15) connected to the housing (4) and at least one connector (5) extending from the housing (4), wherein the actuator comprises a rotary motor having a stator and a rotor, the rotor being arranged inside the tube (15) and the stator being arranged outside the tube (15). A simple way is needed to position the stator and the rotor relative to each other. To this end the stator is fixed to a stator holder (16) which is arranged around the tube (15) and connected to the housing arrangement (4, 5, 15).

The present invention provides a system and method for an improved multistage, cascade refrigeration system using hot gas defrost to rid the evaporator of ice build-up which accumulates over time, while the air in the evaporator enclosure remains below the freezing point of water. The present invention thus provides greater defrost flexibility with increased ease of design and implementation than current refrigeration systems, which allows for more robust hot gas defrost function for multistage refrigeration systems, such that it is unaffected by temperature changes of the condensing fluid (ambient air temperature for air cooled condensers, water temperature for water cooled condensers), and can be readily adapted to any refrigerant suitable for a selected temperature range.