Apparatus and method for cleaning pipes of refrigerating unit

A piping cleaning method for refrigeration units, in which refrigerant piping (3, 5) is cleaned by circulating a cleaning refrigerant through the refrigerant piping, the method comprising:

• circulating liquid refrigerant through the refrigerant piping (3, 5) by two transfer heat exchangers (25, 26) provided on a heat pump use refrigerant circuit other than a cleaning circuit (2) through which the cleaning refrigerant flows, the transfer heat exchangers (25, 26) alternately iterating a sucking operation by cooling a gas refrigerant within the transfer heat exchangers (25, 26) to effectuate depressurization thereof so that a refrigerant is sucked in from outside thereto, and a discharge operation by heating the refrigerant within the transfer heat exchangers (25, 26) to effectuate pressurization thereof so that a liquid refrigerant is discharged therefrom;
• and
• detecting an amount of cleaning refrigerant circulated through the refrigerant piping (3, 5) and, based on the detected amount of cleaning refrigerant, adjusting the amount of cleaning refrigerant.

A piping cleaning system in which a liquid refrigerant is circulated through refrigerant piping (3, 5) by two transfer heat exchangers (25, 26) provided on a heat pump use refrigerant circuit other than a cleaning circuit (2) through which a cleaning refrigerant flows, the transfer heat exchangers (25, 26) alternately iterating a sucking operation by cooling a gas refrigerant within the transfer heat exchangers (25, 26) to effectuate depressurization thereof so that a refrigerant is sucked in from outside thereto, and a discharge operation for heating the refrigerant within the transfer heat exchangers (25, 26) to effectuate pressurization thereof so that a liquid refrigerant is discharged therefrom, wherein

• the heat pump use refrigerant circuit has a throttle mechanism (48, 56) connected between the two transfer heat exchangers (25, 26), a compressor (41) and a four-way switching valve (43), and the piping cleaning system further comprises four-way switching valve switching means (100) for switching over the four-way switching valve (43) every specified time interval, thereby switching over a flowing direction of working refrigerant flowing through the two transfer heat exchangers (25, 26), by which the sucking operation and the discharge operation of the two transfer heat exchangers (25, 26) are switched over.

A piping cleaning method for refrigeration units, in which refrigerant piping (3, 5) is cleaned by circulating a cleaning medium through the refrigerant piping, the method comprising:

• detecting an amount of cleaning medium with which the refrigerant piping (3, 5) is cleaned and, based on the detected amount of cleaning medium, adjusting the amount of cleaning medium.