摘要:
A refrigeration apparatus uses a refrigerant that operates in a region including critical processes, and includes a compression mechanism having first and second compressors, a heat-source-side heat exchanger, an expansion mechanism, a utilization-side heat exchanger, an intercooler, and an intermediate refrigerant pipe. The first compressor has a first low-pressure compression element and a first high-pressure compression element to increase pressure of refrigerant more than the first low-pressure compression element. The second compressor has a second low-pressure compression element and a second high-pressure compression element to increase pressure of refrigerant more than the second low-pressure compression element. The intermediate refrigerant pipe causes refrigerant discharged by the first and second low-pressure compression elements to pass through the intercooler and be sucked into first and second high-pressure the compression elements. The intake sides of the first and second low-pressure compression elements are connected. The discharge sides of the first and second high-pressure compression elements merge.
摘要:
After a refrigerant circuit (10) is formed by connecting a user side circuit (12) and a heat source side circuit (11) by means of a communication pipe (45), a compressor (21) is driven to circulate refrigerant in the refrigerant circuit (10) in a communication pipe cleaning step. Circulation of the refrigerant in the refrigerant circuit (10) peels off oxide which has been deposited on the inner face of the communication pipe (45) by brazing in the communication pipe forming step. The peeled oxide is forced to flow by the refrigerant to be collected on the upstream side of the compressor (21) in the heat source side circuit (11).
摘要:
Disposed is a contaminant recovery receptacle (40) which is connected, through an inflow pipe (42) and an outflow pipe (43), to the suction side of a compressor (21). The inflow pipe (42) has an exit end which opens towards the inner bottom of the recovery receptacle (40). The outflow pipe (43) has an entrance end which is situated above the exit end of the inflow pipe (42) in the recovery receptacle (40). Firstly, a preliminary operation is carried out which causes refrigerant to circulate in a refrigerant circuit (10) for a predetermined length of time so that gas-liquid two-phase refrigerant flows into the recovery receptacle (40). Thereafter, a recovery operation is carried out, which causes refrigerant to circulate in the refrigerant circuit (10) so that gas refrigerant flows into the recovery receptacle (40). As a result, contaminants are recovered in the recovery receptacle (40).
摘要:
A method is disclosed that makes it possible to reduce the amount of refrigerant used and shorten the amount of time over which the new air conditioner must be run in a refrigerant pipe washing mode when an air conditioner that used a mineral-oil-based refrigerant oil is updated to or replaced with an air conditioner using an HFC refrigerant as the working refrigerant and the existing refrigerant piping is reused as is. Thus, the existing refrigerant piping of the air conditioner that used a mineral-oil-based refrigerant oil is reused in the air conditioner that uses an HFC refrigerant as the working refrigerant, the by washing the refrigerant piping using a cleaning agent comprising an HFC refrigerant containing at least 40 wt % of R32 to remove residual refrigerant oil in the refrigerant piping.
摘要:
A refrigerant circuit (15) is provided with a low-pressure stage oil separator (26) for separating refrigerating machine oil out of refrigerant discharged from a low-pressure stage compressor (21) and returning it to the suction side of the low-pressure stage compressor (21), and a high-pressure stage oil separator (36) for separating refrigerating machine oil out of refrigerant discharged from a high-pressure stage compressor (31) and returning it to the suction side of the high-pressure stage compressor (31). The efficiency of oil separation of the low-pressure stage oil separator (26) is set lower than that of the high-pressure stage oil separator (36).
摘要:
A refrigerant circuit (11) includes an oil separator (60) configured to separate oil from high pressure refrigerant, and an oil feed circuit (70) configured to feed the oil separated in the oil separator (60) to a compression mechanism (20) so as to cool the refrigerant in the course of a compression phase of the compression mechanism (20). The oil feed circuit (70) includes a recovery mechanism (40) configured to recover energy of the oil separated in the oil separator (60). In the compression mechanism (20), the refrigerant is cooled by the oil, thereby reducing power of the compression mechanism (20). Simultaneously, in the recovery mechanism (40), power required to increase pressure of the oil in the compression mechanism (20) is recovered.
摘要:
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.
摘要:
A refrigeration system comprises a refrigerant circuit (10) in which a compressor (21), an outdoor heat exchanger (24) and an indoor heat exchanger (33) are connected to operate on a refrigeration cycle, and an oil recovery container (40) connected to the suction side of the compressor (21), and carries out a recovery operation for circulating refrigerant through the refrigerant circuit (10) to recover oil into the recovery container (40). The refrigeration system further comprises: a compressor control section (50) for stepwise increasing the operating capacity of the compressor (21) in an initial stage of the recovery operation so that the refrigerant temperature in the low pressure side of the refrigerant circuit (10) reaches or exceeds a predetermined value; and a fan control section (70) for continuously driving an indoor fan (33a) at least during a time period when the compressor (21) is driven. This suppresses an abrupt start-up of the compressor (21) and ensures that refrigerant in the indoor heat exchanger (33) evaporates. Thus, a temperature drop of refrigerant in the low pressure side can be prevented.
摘要:
The capacity of a compressor (21) in cleaning operation is set based on a Froude number Fr. The Froude number Fr expresses a ratio of an inertial force of a gas refrigerant flowing through a gas side communication pipe (70) to a gravity working on a liquid in the gas side communication pipe (70). The capacity of the compressor (21) in the cleaning operation is set so that the Froude number Fr is larger than 1, whereby the inertial force of the gas refrigerant flowing through the gas side communication pipe (70) becomes larger than the gravity working on the liquid in the gas side communication pipe (70) which contains mineral oil and foreign matters. In this connection, the liquid containing the mineral oil and the foreign matters is pushed up by the gas refrigerant even in a perpendicularly extending portion of the gas side communication pipe (70). Thus, the mineral oil and the foreign matters remaining in the existing liquid side communication pipe (60) and the existing gas side communication pipe (70) are recovered.
摘要:
A method is disclosed that makes it possible to reduce the amount of refrigerant used and shorten the amount of time over which the new air conditioner must be run in a refrigerant pipe washing mode when an air conditioner that used a mineral-oil-based refrigerant oil is updated to or replaced with an air conditioner using an HFC refrigerant as the working refrigerant and the existing refrigerant piping is reused as is. Thus, the existing refrigerant piping of the air conditioner that used a mineral-oil-based refrigerant oil is reused in the air conditioner that uses an HFC refrigerant as the working refrigerant, the by washing the refrigerant piping using a cleaning agent comprising an HFC refrigerant containing at least 40 wt % of R32 to remove residual refrigerant oil in the refrigerant piping.