An air conditioning apparatus may include an outdoor unit through which a first fluid, such as refrigerant circulates, an indoor unit through which a second fluid, such as water circulates, a heat exchange device which is configured to connect the outdoor unit to the indoor unit and in which the first fluid and the second fluid are heat-exchanged with each other, first to third inner tubes configured to connect the outdoor unit to the heat exchange device, and a heat storage unit connected to the first to third inner tubes.

The invention relates to a refrigerant circuit (1), in particular for use in a vehicle, preferably a motor vehicle, comprising: an air conditioning compressor (2), a main condenser (4), at least one connectable condenser (5), and a switching means (3) which is designed to connect one or more of the switchable condensers (5) to the refrigerant circuit (1), wherein a pressure equalising means (6) is configured to equalise an internal pressure of the at least one connectable condenser (5) with an internal pressure of the main condenser (4).

A cooling and battery cooling mode is performed to release the heat from the refrigerant in a heat releasing unit and an outdoor heat exchanger and to absorb the heat into the refrigerant in a heat absorbing unit and a refrigerant-heat medium heat exchanger, and a heating and battery cooling mode is performed to release the heat from the refrigerant in the heat releasing unit and to absorb the heat into the refrigerant in the outdoor heat exchanger and the in-vehicle device heat exchanger. In a case where the cooling and battery cooling mode is performed, when a temperature of the heat absorbing unit is lower than a target value of the temperature of the heat absorbing unit even though the flowing of the refrigerant into the heat absorbing unit is blocked, the operation mode is moved to the heating and battery cooling mode.

An air-conditioning system includes: an air conditioner including a refrigerant circuit formed by connecting an outdoor unit and a plurality of indoor units together, the air conditioner being configured to condition air in a plurality of indoor spaces; at least one countermeasure device provided in correspondence with at least one of the plurality of indoor spaces and configured to operate during leakage of a refrigerant; a plurality of detectors configured to detect a concentration of the refrigerant, at least one of the detectors being provided in each of the plurality of indoor spaces; and a control unit configured to operate all of the at least one countermeasure device if at least one of the concentrations of the refrigerant respectively detected by the plurality of detectors exceeds a predetermined value.

A chiller system includes a mechanical-cooling circuit configured to circulate a refrigerant through an evaporator of the mechanical-cooling circuit, where the evaporator is configured to cool a conditioning fluid with the refrigerant. The chiller system also includes a free-cooling circuit configured to circulate the refrigerant through a heat exchanger of the free-cooling circuit, where the heat exchanger is configured to cool the conditioning fluid with the refrigerant. The chiller system also includes a distribution header having a first inlet configured to receive the refrigerant from the mechanical-cooling circuit, a second inlet configured to receive the refrigerant from the free-cooling circuit, and an internal volume fluidly coupled to the first inlet and the second inlet. A fan coil unit of the chiller system is configured to receive the refrigerant from the internal volume of the distribution header.

A method for defrosting an external heat exchanger, operated as an air heat pump evaporator, of a cooling system for a motor vehicle. The cooling system includes a refrigerant compressor connected to a primary and secondary section; an external heat exchanger; an evaporator; a heating register; a primary section valve which is closed in the air heat pump operation; and a secondary section valve which is open in the air heat pump operation. The method includes closing of the secondary section valve; opening of the primary section valve, so that refrigerant flows directly from the refrigerant compressor to the external heat exchanger; and setting an inlet-side pressure level of the refrigerant on the external heat exchanger to a target pressure which corresponds to a condensation temperature (Tkond) of the refrigerant in the range: 2° C. ≤ Tkond ≤ 20° C., in particular 4° C. ≤ Tkond ≤ 10° C.

An air-conditioning system that performs a refrigeration cycle in a refrigerant circuit includes: an outdoor unit; a plurality of indoor units; a refrigerant connection pipe that connects the outdoor unit and the indoor units; and a first control valve disposed in the refrigerant connection pipe and that blocks a flow of refrigerant. The refrigerant connection pipe includes: a plurality of indoor-side pipes that each communicate with one of the indoor units; an outdoor-side pipe that communicates with two or more of the indoor-side pipes from an outdoor unit side; and a branch that connects the outdoor-side pipe and a group of two or more of the indoor-side pipes.

An air-conditioning system includes: an air conditioner including an outdoor unit and a plurality of indoor units each provided in a corresponding one of a plurality of indoor spaces and each including a first control unit; and a second control unit capable of communicating with the first control units. Each first control unit is capable of communicating with a countermeasure device if the countermeasure device is installed in correspondence with one of the indoor spaces where the first control unit is located. The second control unit has a first function of prohibiting operation of the air conditioner if a first condition where communication between the first control unit and the countermeasure device is not established in any of the indoor units is satisfied.

In a power converter, an inductance L of a reactor and a capacitance C of a capacitor satisfy a condition of the expression (1) below. In the power converter, a current-limiting circuit between an AC power source and the capacitor is unnecessary. Herein, αm ([A.Math.s]) is a value of a ratio of a maximum rated current squared time product to a maximum rated output current of diodes of a rectifier circuit, Pmax is a maximum power consumption of the motor, Vac is a voltage value of a three-phase AC voltage, and a value of a constant a is 4.3 $\begin{array}{cc}a.Math.C.Math.\sqrt{\frac{C}{L}}.Math.\frac{{\mathrm{Vac}}^3}{P_{\max }}\le {\alpha }_m.& \left(1\right)\end{array}$

A heat pump including a housing configured to be disposed outdoors; a compressor that compresses a refrigerant; a fluid refrigerant heat exchanger configured to perform heat exchange between the refrigerant and a fluid; an outdoor heat exchanger configured to perform heat exchange between the refrigerant and outdoor air; a pressure sensor configured to detect a pressure of the refrigerant flowing between the compressor and the fluid refrigerant heat exchanger; a first shut-off valve disposed in a pipe connected to a discharge of the compressor; a second shut-off valve disposed between the outdoor heat exchanger and the compressor; and a controller configured to: determine whether the refrigerant leaks, control the first shut-off valve to be closed, when the refrigerant leaks, and control the second shutoff valve to be closed, when the pressure sensed by the pressure sensor is less than a predetermined reference pressure.