A system has: a compressor having a suction port and a discharge port; an ejector having a motive flow inlet, a suction flow inlet, and an outlet; a separator having an inlet, a vapor outlet, and a liquid outlet; a first heat exchanger; an expansion device; and a second heat exchanger. Conduits and valves are positioned to provide alternative operation in: a cooling mode and a heating mode. In the cooling mode, a needle of the ejector is closed. In the heating mode refrigerant passes sequentially from a first section of the second heat exchanger to a second section. In the cooling mode refrigerant passes in parallel through the first section and the second section.

Thermoelectric enhanced hybrid heat pump systems are provided herein. A compressor increases the pressure of refrigerant within tubing. A first heat exchanger is downstream of the compressor and changes enthalpy of first fluid flow through heat exchange with refrigerant. A second heat exchanger changes enthalpy of second fluid flow through heat exchange with refrigerant. A thermoelectric device is downstream of the first heat exchanger and reduces refrigerant temperature. Expansion valves are downstream of the thermoelectric device and first heat exchanger, respectively located on first and second sides of the thermoelectric device, and expand refrigerant and reduce refrigerant pressure while conserving refrigerant enthalpy. At least one valve reverses refrigerant flow within the tubing without changing compressor operation. A control system controls the thermoelectric device and at least one valve to switch the heat pump system from heating mode to cooling mode and from cooling mode to heating mode.

A method of conditioning air includes controlling a secondary refrigerant flow control valve to select between a first mode in which refrigerant flows from a discharge line to a main refrigerant flow control valve, and a second mode in which refrigerant flows from the discharge line to a gas reheat heat exchanger and then flows to the main refrigerant flow control valve. A heat transfer medium flow control valve is controlled to adjust the flow of the heat transfer medium into a heat source side heat exchanger. The heat transfer medium flow control valve allows the heat transfer medium to flow to the heat source side heat exchanger when the secondary refrigerant flow control valve is in the first mode, and adjusts the flow of the heat transfer medium to the heat source side heat exchanger when the secondary refrigerant flow control valve is in the second mode.

A carbon dioxide refrigerating system and a refrigerating method thereof. A carbon dioxide refrigerating system, comprising a compressor (10), a condenser (11), a liquid storage device (12), and an evaporator (13) connected in sequence; a suction assembly (15) is arranged between the compressor (10) and the condenser (11), the suction assembly (1%) being in communication with the liquid storage device (12) and in communication with a gas-liquid separator (14), the gas-liquid separator (14) being arranged between the condenser (11) and the liquid storage device (12), and the carbon dioxide gas in the liquid storage device (12) or the gas-liquid separator (14) being capable of being sucked back into the pipeline between the compressor (10) and the condenser (11) by means of the suction assembly (15). The refrigerating system can effectively separate gas and liquid, and can also flash evaporate part of the liquid and supercool the carbon dioxide; the flash evaporation-type condenser (11) can achieve a refrigerating effect by means of radiation, and aerosol is formed in the cavity, quickly evaporating and cooling, and thereby increasing the refrigerating efficiency; the refrigerating system has a simple structure, convenient operation, and low installation and maintenance costs.

A motor driver for driving a motor including three-phase windings includes: an inverter that applies a desired voltage to the motor; and an inverter controller that controls an operation of the inverter. The inverter includes: a current detector that detects a direct current in a first connecting line among three-phase connecting lines connecting the respective three-phase windings and the inverter; and a current detector that detects an alternating current in a second connecting line among the three-phase connecting lines, and a maximum direct current is caused to flow to the first connecting line in a first control mode for positioning a rotor of the motor.

A refrigeration cycle apparatus provided with: a compressor; a first heat exchanger; a second heat exchanger; a third heat exchanger; a first heat medium passage connecting a heat medium outlet of the third heat exchanger to a heat medium inlet of the second heat exchanger; a first bypass valve; a second heat medium passage to allow the heat medium flowing out of the second heat exchanger to flow into a second load device; a second bypass valve; a return passage; a flow path switching valve to switch between a first mode in which the heat medium flows into the first heat medium passage from the return passage without passing through the third heat exchanger and a second mode in which the heat medium flows into the third heat exchanger from the return passage.

An air-conditioning apparatus includes a refrigerant circuit formed by connecting a compressor that discharges a zeotropic refrigerant, an outdoor-side heat exchanger that exchanges heat between outside air and the refrigerant, a first expansion device that regulates the pressure of the refrigerant, and a load-side heat exchanger that exchanges heat between the air in an air-conditioning target space and the refrigerant. The air-conditioning apparatus includes a controller that has a composition computing function unit and a composition determining function unit The composition determining function unit is configured to adopt a predetermined value set in advance and related to composition as a circulating composition if the computation result is determined as incorrect, and adopt the computation result as the circulating composition if the computation result is determined as correct.

An air-conditioning apparatus includes a low-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant that flows into a compressor and outputs it as a first detection value and a high-pressure-side pressure sensor that detects the pressure of heat-source-side refrigerant discharged from the compressor and outputs it as a second detection value. When switching the operation mode of the apparatus, a controller determines whether the ratio of the first detection value to the second detection value is higher than a first threshold. When the ratio is higher than the threshold, the controller causes a second refrigerant flow switching device to perform a switching operation. When the ratio is less than or equal to the threshold, the controller makes an adjustment such that an opening degree of an expansion device is less than a second threshold, and then causes the second refrigerant flow switching device to perform the switching operation.

The present disclosure provides an air conditioner. The air conditioner includes a compressor; a sensor for measuring the compressors state configured to detect compressor state information that includes at least one of a pressure value and a saturation temperature of the compressor; and a controller configured to control air flow on the side of an indoor unit by comparing the compressor state information measured from the sensor and a threshold.

In an air-conditioning apparatus including a refrigerant circulating circuit A and a heat medium circulating circuit B that performs passing of heat to and from the refrigerant circulating circuit A, the heat medium circulating circuit is a closed circuit, the maximum pump head Pp of a pump of the heat medium circulating circuit is 150 kPa or more, and a pressure near at least a suction side of the pump is set to a charged pressure that is maintained equal to or higher than the atmospheric pressure during operation of the pump.