Abstract: An air conditioner includes a refrigerant circuit which connects an outdoor circuit and a plurality of indoor circuits connected in parallel. The air conditioner includes a leak detection section which detects leak of a refrigerant from the indoor circuits, and a control section which circulates the refrigerant to perform a refrigeration cycle when the leak detection section detects leak of the refrigerant such that the refrigerant in the indoor circuits of the refrigerant circuit is at a low pressure. Providing the control section in the air conditioner can reduce the leak of the refrigerant from the indoor circuit at low cost.

Abstract: A refrigerant charging method includes installing, cooling, confirming, and moving steps. In the installing step, a refrigeration device is installed on site. In the cooling step, a container is cooled to 31° C. or below using a cooling medium. In the confirming step, it is confirmed that the container has reached 31° C. or below. In the moving step, the refrigerant is moved to the intended charging space from the container upon confirming that the container has reached 31° C. or below via the cooling step. When moving the refrigerant from the container to the intended charging space, first, refrigerant that is in a gas phase within the container is moved into the intended charging space, whereupon refrigerant that is in a liquid phase within the container is moved into the intended charging space.

Abstract: An air conditioner includes a refrigerant circuit which connects an outdoor circuit and a plurality of indoor circuits connected in parallel. The air conditioner includes a leak detection section which detects leak of a refrigerant from the indoor circuits, and a control section which circulates the refrigerant to perform a refrigeration cycle when the leak detection section detects leak of the refrigerant such that the refrigerant in the indoor circuits of the refrigerant circuit is at a low pressure. Providing the control section in the air conditioner can reduce the leak of the refrigerant from the indoor circuit at low cost.

Abstract: An air conditioning device capable of preventing drainage water dropped down from a heat exchange portion on the upper side for which a defrosting operation is performed from being frozen again in a heat exchange portion used for a heating operation, so that a decrease in a heating ability can be suppressed is provided. In an air conditioning device including a heat source side heat exchanger formed by providing a plurality of heat exchange portions, to which a refrigerant is supplied through different paths from each other, side by side in the up and down direction, and partial defrosting means for, while the heating operation is performed by using a part of the heat exchange portions, performing the defrosting operation for the other heat exchange portions, a drainage mechanism for draining drainage water generated in each of the heat exchange portions is provided for each of the heat exchange portions.

Abstract: An air conditioning apparatus includes a defrosting flow channel mechanism. The air conditioning apparatus performs an air-warming defrost operation in which refrigerant sent from an indoor heat exchanger to an outdoor heat exchanger is evaporated while defrosting an arbitrarily selected heat exchange path using the defrosting flow channel mechanism. In the defrost operation, the refrigerant sent to the outdoor heat exchanger from the indoor heat exchanger is not channeled into the refrigerant flow diverter but is passed through the arbitrarily selected heat exchange path from the gas-side end to the liquid-side end of the arbitrarily selected heat exchange path, and the refrigerant passed through the arbitrarily selected heat exchange path flows through the refrigerant flow diverter to be passed through other heat exchange paths other than the arbitrarily selected heat exchange path from the liquid-side end to the gas-side end of the other heat exchange paths.

Abstract: An air conditioning system includes a refrigerant circuit (20) in which a compressor (21), an indoor radiant panel (23), a first expansion valve (24), a room air heat exchanger (25), a second expansion valve (26) and an outdoor air heat exchanger (27) are connected in this order and which operates in a refrigeration cycle by reversibly circulating refrigerant therethrough. During a defrosting operation, the first expansion valve (24) is controlled to reduce the refrigerant pressure so that in a cooling cycle the refrigerant releases heat in the outdoor air heat exchanger (27) and the room air heat exchanger (25) and evaporates in the indoor radiant panel (23). Thus, the air conditioning system concurrently provides the defrosting of the outdoor air heat exchanger (27) and the room heating of the room air heat exchanger (25).

Abstract: A refrigerant charging method for an air conditioning device in which carbon dioxide is used as a refrigerant includes a connecting step and a refrigerant charging step. In the connecting step, a cylinder containing the refrigerant is connected to a space in the air conditioning device intended to be charged by the refrigerant. A heater is interposed between the cylinder and the air conditioning device. In the refrigerant charging step, the refrigerant is moved to the intended charging space from the cylinder, via the heater. In the refrigerant charging step, further, the refrigerant that has exited the cylinder is heated by the heater so that a specific enthalpy of the refrigerant when it enters the intended charging space will be 430 kJ/kg or higher.

Abstract: An air-conditioning apparatus uses carbon dioxide as a refrigerant, and includes a two-stage-compression-type compression mechanism, a heat source-side heat exchanger, an expansion mechanism, a usage-side heat exchanger, and an intercooler. The intercooler uses air as a heat source. The intercooler is configured and arranged to cool refrigerant flowing through an intermediate refrigerant tube that draws refrigerant discharged from the first-stage compression element into the second-stage compression element. The intercooler is integrated with the heat source-side heat exchanger to form an integrated heat exchanger, with the intercooler disposed in an upper part of the integrated heat exchanger.

Abstract: A method of cleaning an air conditioner utilizing carbon dioxide as a working refrigerant includes three steps. In a charging step, a refrigeration cycle is charged with carbon dioxide. In a venting step, a charging target with which the refrigeration cycle is charged is vented after the charging step. In a repeating step a unit operation is performed at least one time or more. The unit operation includes the charging step and the venting step. An air conditioner includes a refrigeration cycle configured to perform the unit operation at least one time, and a counter configured to count and output the number of times that the unit operation has been performed.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a liquid receiver, a second expansion mechanism, an evaporator, a pressure detector, a temperature detector, and a control unit. The pressure detector is provided between the refrigerant discharge side of the compression mechanism and the refrigerant inflow side of the first expansion mechanism. The temperature detector is provided between the exit side of the radiator and the refrigerant inflow side of the first expansion mechanism. The control unit controls the first expansion mechanism using the pressure detected by the pressure detector and the temperature detected by the temperature detector so that the refrigerant flowing out from the first expansion mechanism reaches a saturated state.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes heat to be exchanged between refrigerant that flows from the radiator to the inflow side of the first expansion mechanism, and refrigerant that flows from the evaporator to the compression mechanism. The branch pipe branches from a third refrigerant pipe for connecting the radiator and the second expansion mechanism, and merges with the second refrigerant pipe. A third expansion mechanism is provided to the branch pipe. The second internal heat exchanger causes heat to be exchanged between refrigerant that flows out from the first expansion mechanism, and refrigerant that flows out from the third expansion mechanism.

Abstract: A refrigeration device includes a control unit, and a refrigerant circuit in which a compression mechanism, a radiator, a refrigerant cooling unit, a first expansion mechanism, a liquid receiver, a second expansion mechanism, and an evaporator are connected in sequence. The control unit performs refrigerant cooling control whereby the refrigerant is cooled by the refrigerant cooling unit so that the state of the refrigerant that has flowed out from the first expansion mechanism is near the saturation line and not near the critical point.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism (15), a liquid receiver (16), a second expansion mechanism, an evaporator, a temperature detector, a first pressure storing unit (23a), and a second pressure determining unit, a pressure detector, and a control unit (23c). The first pressure storing unit stores an upper limit and lower limit of an intermediate pressure. The second pressure determining unit determines an upper limit and lower limit of a high pressure based on the upper limit and lower limit of the intermediate pressure and on a temperature in a vicinity of an exit of the radiator. The control unit controls the first expansion mechanism and the second expansion mechanism so that a pressure detected by the pressure detector will be equal to or less than the upper limit and equal to or greater than the lower limit of the high pressure.

Abstract: An air conditioning system includes a compressor, a first heat source-side heat exchanger for heating or cooling a refrigerant, a second heat source-side heat exchanger for exchanging heat between the refrigerant and a heat delivery medium, a first utilization-side heat exchanger for performing indoor cooling by using the refrigerant cooled in the first heat source-side heat exchanger, a second utilization-side heat exchanger for performing indoor heating by using the heat delivery medium subjected to heat exchange in the second heat source-side heat exchanger, and a connection mechanism.

Abstract: An air-conditioning apparatus uses carbon dioxide as a refrigerant, and includes comprises a two-stage-compression-type compression mechanism, a heat source-side heat exchanger, an expansion mechanism, a usage-side heat exchanger, and an intercooler. The intercooler uses air as a heat source. The intercooler is configured and arranged to cool refrigerant flowing through an intermediate refrigerant tube that draws refrigerant discharged from the first-stage compression element into the second-stage compression element. The intercooler is integrated with the heat source-side heat exchanger to form an integrated heat exchanger, with the intercooler disposed in an upper part of the integrated heat exchanger.

Abstract: A refrigeration apparatus uses a refrigerant that operates in a supercritical range, and includes a compression mechanism, a heat source-side heat exchanger, an expansion mechanism, a usage-side heat exchanger, an intercooler and an intermediate oil separation mechanism. The compression mechanism has a plurality of compression elements, and is configured and arranged so that refrigerant discharged from a first-stage compression element is sequentially compressed by a second-stage compression element. The intercooler is configured and arranged to cool refrigerant flowing through an intermediate refrigerant tube that draws refrigerant discharged from the first-stage compression element into the second-stage compression element. The intermediate oil separation mechanism is configured and arranged to separate a refrigeration oil from the refrigerant discharged from the first-stage compression element.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe, a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes heat to be exchanged between refrigerant that flows from the radiator to the inflow side of the first expansion mechanism, and refrigerant that flows from the evaporator to the compression mechanism. The branch pipe branches from a third refrigerant pipe for connecting the radiator and the second expansion mechanism, and merges with the second refrigerant pipe. A third expansion mechanism is provided to the branch pipe. The second internal heat exchanger causes heat to be exchanged between refrigerant that flows out from the first expansion mechanism, and refrigerant that flows out from the third expansion mechanism.

Abstract: A refrigerant charging method in an air conditioner using carbon dioxide as a refrigerant includes a first refrigerant charging step and a second refrigerant charging step. The first refrigerant charging step is a step of charging a refrigerant charging target portion including refrigerant communication pipes with refrigerant in a gas state until the pressure of the refrigerant charging target portion rises to a predetermined pressure after the start of charging. The second refrigerant charging step is a step of charging the refrigerant charging target portion with refrigerant in a liquid state until the amount of refrigerant charging the refrigerant charging target portion becomes a predetermined amount. The second refrigerant charging step occurring after the first refrigerant charging step.

Abstract: A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a liquid receiver, a second expansion mechanism, an evaporator and a control unit. The control unit minimizes the degree of pressure reduction by the first expansion mechanism when the refrigerant that flows from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the first expansion mechanism has reached a subcritical state.

Abstract: A refrigeration device includes a control unit, and a refrigerant circuit in which a compression mechanism, a radiator, a refrigerant cooling unit, a first expansion mechanism, a liquid receiver, a second expansion mechanism, and an evaporator are connected in sequence. The control unit performs refrigerant cooling control whereby the refrigerant is cooled by the refrigerant cooling unit so that the state of the refrigerant that has flowed out from the first expansion mechanism is near the saturation line and not near the critical point.