A refrigerant cycle apparatus includes a refrigerant circuit that circulates a refrigerant, and a leak sensor that detects a refrigerant leaking from the refrigerant circuit, in which the refrigerant cycle apparatus includes, as an operating mode, a recovery mode for recognizing occurrence of an abnormality in the leak sensor and recovering a refrigerant to a predetermined location in the refrigerant circuit.

A refrigeration apparatus includes a refrigerant circuit switchable between a first operation of performing a refrigeration cycle in which a first compressor is stopped and a second compressor is driven and a second operation of performing a refrigeration cycle in which the first and second compressors and are driven. The refrigeration apparatus further includes a reduction mechanism configured to reduce a refrigerant flowing into the first compressor while a first condition is satisfied during the first operation. The first condition indicates that an internal pressure of the first compressor is lower than an evaporation pressure of an evaporator.

A valve opening circuit mounted on a heat pump device having a valve on a refrigerant circuit includes a DC electric path to which a DC voltage generated from an AC voltage for normal use is applied, a valve drive circuit that opens and closes the valve by using the DC voltage of the DC electric path, a control unit that acquires a control power source voltage based on the DC voltage of the DC electric path and controls the valve drive circuit, and a power feed port connected to the DC electric path and connectable to a DC power source line provided from outside for emergency. The control unit causes the valve drive circuit to open the valve when the AC voltage is lost and the DC voltage is fed from the DC power source line to the power feed port.

A heat pump system is provided. The heat pump system comprises a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger and a six-way valve. The compressor comprises an air suction port and an air discharge port. The first heat exchanger is arranged in a first circulation path, the second heat exchanger is arranged in a second circulation path, and the third heat exchanger is arranged in a third circulation path, wherein the first circulation path, the second circulation path and the third circulation path are parallel paths. A first end of the first circulation path, a first end of the second circulation path and a first end of the third circulation path are connected to the six-way valve and are in controllable communication with the air suction port and the air discharge port of the compressor by means of the six-way valve. A second end of the first circulation path, a second end of the second circulation path and a second end of the third circulation path are connected to a common path converging point. The components of the heat pump system in the present application have simple pipelines, have a high degree of integration, are not difficult to mount, and have a small pressure drop during air suction and discharge, and the control logic therefor is simple.

According to one embodiment, in a low speed drive of outdoor fans, a first flow rate adjusting valve in a main outdoor heat exchanger side is narrowed to a closing degree or a close range thereof, and an opening degree of a second flow rate adjusting valve is controlled such that a supercooling degree of refrigerant in auxiliary outdoor heat exchangers becomes constantly a target value.

An EXV (electronic expansion valve) control system includes an EXV controller for controlling an EXV within the refrigerant loop of an HVAC system. The EXV controller implements a master control algorithm that includes a plurality of sub-control algorithms and an initial series of branching decision points to determine the current mode of operation and to execute select sub-control algorithms corresponding to the current mode of operation, while not executing the sub-control algorithms corresponding to the other modes of operation. The sub-control algorithms implement various combinations of PID (Proportional Integral Derivative) control and feed-forward control, the results of which can be mapped to specific control instructions for the EXV.

A heat transfer apparatus includes a plurality of “n” number of control valves, each of the plurality of “n” number of control valves including a control valve inlet and a control valve outlet; a like plurality of “n” number of evaporator sections, each of the like plurality of “n” number of evaporator sections including an evaporator section inlet and an evaporator section outlet, each evaporator section inlet fluidly coupled to a corresponding one of the plurality of “n” number of control valve outlets, each evaporator section configured to extract heat from at least one heat load that is in thermal conductive or convective contact or proximate to the evaporator section; a refrigerant fluid inlet fluidly coupled to the like plurality of evaporator sections; and a refrigerant fluid outlet fluidly coupled to the like plurality of evaporator sections.

A freezer and method of operating a freezer are provided with an adaptive defrost cycle. The freezer includes a controller that operates the freezer to: provide cooling to a cabinet via an evaporator during periodic operational cycles, monitor a time elapsed since a most recent defrost cycle, determine whether the time elapsed is greater than a current defrost interval, and perform a defrost cycle if so. The controller varies the current defrost interval between a first, larger time value and a second, smaller time value based on a plurality of trigger signals in response to various operating characteristics of the freezer monitored by sensors. After each defrost cycle is completed, the current defrost interval is reset to the first, larger time value.

Embodiments of the disclosure provide a controller for a compressor and a control method, a compressor assembly, and a refrigeration system, which improve control efficiency and reliability. The controller includes an obtaining module configured to obtain at least one operation state parameter of the compressor, and a controlling module configured to shut off a liquid injection valve if one of the at least one operation state parameter of the compressor meets a protection action condition, wherein the liquid injection valve is configured to regulate flow of fluid injected into the compressor.

A heating, ventilation, and/or air conditioning (HVAC) unit includes a first sensor disposed adjacent to an inlet of an evaporator configured to receive an airflow. The HVAC unit includes a second sensor disposed adjacent to an outlet of a reheat coil positioned downstream of the evaporator and configured to expel the airflow. The HVAC unit also includes a controller configured to regulate operation of a modulating reheat valve to adjust flow of a working fluid in thermal communication with the airflow to control a difference between a measurement of the first sensor and a measurement of the second sensor.