Abstract: A multi-type air conditioning device controls an evaporation temperature and a condensing temperature, depending on required capacity of an indoor unit. The air conditioning device compares a current evaporation temperature or condensing temperature with a reference value, of an evaporation temperature or an condensing temperature, corresponding to a lower limit flow rate, of a gaseous refrigerant, required for refrigerating machine oil not to accumulate in, but to flow through, the gas branch pipes, and calculates an amount of the refrigerating machine oil accumulated in a gas branch pipe which does not satisfy the lower limit flow rate. When the calculated amount exceeds a set amount, the air conditioning device performs oil collecting operation, and controls the oil collecting operation in view of a flow rate of a gaseous refrigerant in gas branch pipes.

Abstract: When charging a refrigerant circuit with refrigerant, a control component starts a heating refrigerant charging operation that is performed by switching the refrigerant circuit to a heating cycle state and performs the heating refrigerant charging operation until a predetermined heating refrigerant charging completion condition is met. Thereafter, the control component switches to a cooling refrigerant charging operation that is performed by switching the refrigerant circuit to a cooling cycle state and performs the cooling refrigerant charging operation until a refrigerant charging completion condition where the refrigerant circuit is charged with a prescribed quantity of the refrigerant is met.

Abstract: In a case where the total volume of plural indoor heat exchangers is smaller than the volume of an outdoor heat exchanger, a control component performs a heating refrigerant charging operation until a heating refrigerant charging completion condition is met, and thereafter performs a cooling refrigerant charging operation until a refrigerant charging completion condition where a refrigerant circuit is charged with a prescribed quantity of refrigerant is met.

Abstract: Provided is a refrigeration apparatus in which a decrease in a temperature of an indoor heat exchanger can be suppressed as much as possible while depletion of refrigerator oil in a compressor is also suppressed. An air-conditioning apparatus configured from a parallel connection of a plurality of outdoor units to an indoor unit, wherein when a predetermined defrosting condition has been fulfilled, a controller includes at least one processor programmed to selectively execute a reverse-cycle defrost mode when a predetermined outflow condition pertaining to an outflow integrated quantity of refrigerator oil has also been fulfilled, and selectively execute an alternating defrost mode, in which the outdoor unit that is to be defrosted is changed in sequence, when the predetermined outflow condition has not been fulfilled.

Abstract: In an air conditioning device (10) to which an outdoor unit (20) and indoor units (40) are connected, when a flow rate of a gaseous refrigerant in a gas main pipe (72a) is lower than a lower limit flow rate in main pipe, an amount of refrigerating machine oil accumulated in the gas main pipe (72a) is calculated. When gas branch pipes (72b) include a gas branch pipe (72b) having a flow rate lower than a lower limit flow rate in branch pipe even though the flow rate of the gaseous refrigerant in the gas main pipe (72a) is higher than the lower limit flow rate in main pipe, an amount of the machine oil accumulated in the gas branch pipe (72b) is calculated. When the amounts are integrated and the integrated value exceeds a set amount, oil collecting operation is performed.

Abstract: A multi-type air conditioning device controls an evaporation temperature and a condensing temperature, depending on required capacity of an indoor unit. The air conditioning device compares a current evaporation temperature or condensing temperature with a reference value, of an evaporation temperature or an condensing temperature, corresponding to a lower limit flow rate, of a gaseous refrigerant, required for refrigerating machine oil not to accumulate in, but to flow through, the gas branch pipes, and calculates an amount of the refrigerating machine oil accumulated in a gas branch pipe which does not satisfy the lower limit flow rate. When the calculated amount exceeds a set amount, the air conditioning device performs oil collecting operation, and controls the oil collecting operation in view of a flow rate of a gaseous refrigerant in gas branch pipes.

Abstract: A refrigeration apparatus includes a compressor, a heat source-side heat exchanger, a receiver, a utilization-side heat exchange, a receiver degassing pipe interconnecting an upper portion of the receiver and a suction side of the compressor, and a receiver liquid level detection pipe connected to the receiver. The receiver liquid level detection pipe detects whether or not liquid level in the receiver has reached a predetermined position on a lower side of a position where the receiver degassing pipe is connected. The receiver liquid level detection pipe merges with the receiver degassing pipe via a capillary tube. The receiver degassing pipe has a refrigerant heater to heat refrigerant flowing through the receiver degassing pipe. Whether or not the liquid level in the receiver has reached the predetermined position is detected using a temperature of refrigerant flowing though the receiver degassing pipe.

Abstract: A refrigeration apparatus includes a compressor, a heat-source-side heat exchanger operable as a refrigerant evaporator or radiator, and a usage-side heat exchanger operable as a refrigerant evaporator or radiator. The heat-source-side heat exchanger is disposed inside a heat source unit having an exhaust port and an outdoor fan in an upper part, and an intake port in a side part. The heat-source-side heat exchanger includes first and second heat-source-side heat exchangers. Adjustable first and second heat-source-side flow rate adjusting valves are connected to liquid sides of the first and second heat-source-side heat exchangers, respectively. In a defrost operation in order to defrost the first and second heat-source-side heat exchangers, the opening degrees of the first and second heat-source-side flow rate adjusting valves are controlled so as to achieve a defrost flow rate ratio at which more refrigerant flows to the second heat-source-side heat exchanger than during an air-cooling operation.

Abstract: A refrigeration apparatus includes a refrigerant circuit connecting heat-source units in parallel with usage units. First and second heat-source units have first and second compressors, first and second heat-source-side heat exchangers, first and second high-pressure receivers, first and second detecting elements detecting whether the receivers are near flooding, first and second bypass channels returning refrigerant in top parts of the receivers to intake sides of the compressors, and first and second motor-operated valves on the bypass channels, respectively. A controller performs excess refrigerant distribution control in which an opening degree of the first valve is controlled to be greater than an opening degree of the second valve when the second detecting element detects a nearly flooded state, and the opening degree of the second valve is controlled to be greater than the opening degree of the first valve when the first detecting element detects a nearly flooded state.

Abstract: A heat source unit includes a compressor, first and second heat exchangers connected in parallel, first and second motor-operated valves regulating amounts of refrigerant that flow to the first and second heat exchangers, first and second temperature sensors measuring temperatures of refrigerant flowing from the first and second motor-operated valve to the first and second heat exchangers, a discharge temperature sensor measuring temperature of refrigerant discharged from the compressor, and a valve opening controller. The controller regulates valve openings of the first and second motor-operated valves based on the discharge temperature, refrigerant temperature detected by the first temperature sensor and refrigerant temperature detected by the second temperature sensor.

Abstract: A refrigeration apparatus includes a refrigerant circuit connecting heat-source units in parallel with usage units. First and second heat-source units have first and second compressors, first and second heat-source-side heat exchangers, first and second high-pressure receivers, first and second detecting elements detecting whether the receivers are near flooding, first and second bypass channels returning refrigerant in top parts of the receivers to intake sides of the compressors, and first and second motor-operated valves on the bypass channels, respectively. A controller performs excess refrigerant distribution control in which an opening degree of the first valve is controlled to be greater than an opening degree of the second valve when the second detecting element detects a nearly flooded state, and the opening degree of the second valve is controlled to be greater than the opening degree of the first valve when the first detecting element detects a nearly flooded state.

Abstract: A refrigeration apparatus includes a compressor, a heat source-side heat exchanger, a receiver, a utilization-side heat exchange, a receiver degassing pipe interconnecting an upper portion of the receiver and a suction side of the compressor, and a receiver liquid level detection pipe connected to the receiver. The receiver liquid level detection pipe detects whether or not liquid level in the receiver has reached a predetermined position on a lower side of a position where the receiver degassing pipe is connected. The receiver liquid level detection pipe merges with the receiver degassing pipe via a capillary tube. The receiver degassing pipe has a refrigerant heater to heat refrigerant flowing through the receiver degassing pipe. Whether or not the liquid level in the receiver has reached the predetermined position is detected using a temperature of refrigerant flowing though the receiver degassing pipe.