A refrigeration appliance with multiple storage compartments has a refrigerant circuit with a first expansion valve, a first heat exchanger, a second expansion valve, and a second heat exchanger connected in series between pressure and suction connections of a compressor. Each heat exchanger is associated with at least one storage compartment in order to control its temperature. A control unit controls the compressor rotational speed and positions of the expansion valves. The control unit has a continuously linear regulator for each storage compartment with a P-component for estimating a required temperature control output using a difference between actual and target temperatures. A model computing unit ascertains a target evaporation temperature for a first storage compartment controlled by the first heat exchanger, and for a second storage compartment controlled by the second heat exchanger. The heat exchangers are operated by selecting the compressor rotational speed and the valve positions of the expansion valves.

A rotor is a rotor for a pump. The rotor includes a rotor core having a magnet insertion hole and having an annular shape about an axis, a permanent magnet inserted in the magnet insertion hole, and a rotor cover surrounding the rotor core from outside in a radial direction about the axis. The rotor core has a first core portion disposed on an inner side of the magnet insertion hole in the radial direction, a second core portion disposed on an outer side of the magnet insertion hole in the radial direction, and a hole separating the first core portion and the second core portion from each other. The rotor cover has a positioning portion that positions the first core portion and the second core portion in a circumferential direction about the axis.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

An air conditioner comprises: a refrigerant circuit configured to circulate refrigerant through a compressor, a condenser, an LEV and an evaporator; a first temperature sensor configured to sense the temperature of liquid refrigerant at the inlet port of the evaporator; and a controller configured to control the compressor and the LEV. In a case where a temperature sensed by the first temperature sensor is lower than a frosting reference temperature, the controller increases the opening degree of the LEV and also increases the operating frequency of the compressor as compared with a case where the temperature sensed by the first temperature sensor is higher than the frosting reference temperature.

Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

A system for controlling a capacity of a compressor includes a motor of the compressor including a main winding connected at a connection point to an auxiliary winding and a drive configured to control a speed of the motor. The system includes a first switch configured to selectively connect the main winding to either a first line voltage or a first output of the drive, a second switch configured to selectively connect the connection point to either a second line voltage or a second output of the drive, and a third switch configured to selectively connect the auxiliary winding to either a capacitor or a third output of the drive. The system includes a solenoid valve configured to selectively either operate in a first capacity or a second capacity. The system includes a control module configured to control the drive, the first switch, the second switch, and the third switch.

The invention relates to an electric vehicle cabin heating system and a control method. The system comprises a first refrigerant circuit and a second refrigerant circuit that are connected in parallel, wherein the circuits each comprise a gas-liquid separator and a compressor that are connected in series; the first refrigerant circuit further comprises a first expansion unit; the second refrigerant circuit further comprises a second expansion unit and a condenser; and the first expansion unit is connected to the second expansion unit and the condenser in parallel. Thus, rapid cabin heating and stable heating capacity are achieved, the dependence on a heater is eliminated, and an air-conditioning system is simplified. The method comprises: a refrigerant in the second refrigerant circuit undergoing pressure regulation via the second expansion unit and then entering the condenser to release heat for heating a cabin; and a refrigerant in the first refrigerant circuit undergoing throttling and pressure reduction via the first expansion unit and converges with the refrigerant in the second refrigerant circuit in the gas-liquid separator, and the converging refrigerant enters the compressor for cycling. Thus, the decoupling between the regulation of heating capacity and the temperatures and flow rate of exterior ambient air and cabin air is achieved, and the problems of insufficient heating capacity and frequent defrosting of a heat pump system at a low temperature are solved.

Described is a regulation apparatus for a refrigeration plant having defined therein a refrigerant fluid path and a plurality of devices arranged along the refrigerant fluid path. The regulation apparatus includes a first sensor arranged in a first point (P1), and preferably a second sensor arranged in a second point (P3), both along the refrigerant fluid path. The control unit controls a first value measured by the first sensor and obtains a first regulation request of a device deriving from the first measured value as well as a second value measured by the second sensor, or calculated for the second point, and derives a second regulation request of the device deriving from the second measured value, compares the first and second regulation requests and establishes which regulation request is greater. A control unit commands an actuation device to actuate the most effective regulation request of the refrigeration plant devices.

Described is a regulation apparatus for a refrigeration plant having defined therein a refrigerant fluid path and a plurality of devices arranged along the refrigerant fluid path. The regulation apparatus includes a first sensor arranged in a first point (P1) and a second sensor arranged in a second point (P3), each along the fluid path of the refrigeration plant, a control unit and an actuation device. The control unit controls a first value measured by the first sensor and obtains a first regulation request deriving from the first measured value as well as a second value measured by the second sensor and derives a second regulation request deriving from the second measured value, compares the first and second regulation requests, and establishes which regulation request is greater. The control unit also commands the actuation device to actuate the most effective regulation request of the refrigeration plant devices.

Example embodiments of the present disclosure relate to an HVAC system, and methods for controlling the system, that mitigate the impact of refrigerant leaks before the leaks are even detected. Some embodiments include an HVAC system operable to mitigate refrigerant leaks, the system including an indoor unit including an indoor fan and an indoor heat exchanger, an outdoor unit including an outdoor heat exchanger and a compressor, a refrigerant circuit including a refrigerant circulated between the indoor unit and the outdoor unit, a mass control valve coupled to the refrigerant circuit, and control circuitry configured to: operate the HVAC system to satisfy a conditioning load by circuiting the refrigerant through the refrigerant circuit and operating the indoor fan, and completely close the mass control valve to at least partially isolate the refrigerant circuit at the indoor heat exchanger in response to the indoor fan being shut off.