Abstract: A refrigerating apparatus having a plurality of compressors includes an injection circuit (40) which includes a first injection pipe (37) branched from a first refrigerant pipe (32) of a refrigerant circuit (10) and branch injection pipes (37a, 37b, 37c) branched from the first injection pipe (37), a subcooling pressure-reducing valve (29) provided to the first injection pipe (37), and flow rate adjusting valves (30a, 30b, 30c) provided to the branch injection pipes (37a, 37b, 37c), respectively, thereby providing an appropriate refrigerant injection to each of the compressors.

Abstract: In a refrigeration system in which a compressor mechanism including a plurality of compressors, oil separators (37a, 37b) are provided at a discharge pipe (56a) of a first compressor (14a) and a discharge pipe (56b) of a second compressor (14b), respectively. An oil return passageway (32) for returning refrigerating machine oil from the oil separators (37a, 37b) to a compressor mechanism (40) is configured to combine streams of refrigerating machine oil separated in the oil separators (37a, 37b) and distribute the combined refrigerating machine oil to the first compressor (14a) and the second compressor (14b).

Abstract: A refrigeration device includes a switching valve control section for outputting a switching signal for controlling a four-way switching valve to a predetermined switching state when starting a compression mechanism; and a switching determination section which, when starting only a first compressor as a start-up of the compression mechanism, outputs a low differential pressure signal if a differential pressure between a high-pressure port and a low-pressure port in the four-way switching valve falls below a determination value in a determination operation after the switching signal being outputted by the switching valve control section. After the switching determination section outputs the low differential pressure signal, a capacity control section starts a second compressor.

Abstract: In a refrigeration system, a first non-inverter compressor (2B) backs up one of an inverter compressor (2A) and a second non-inverter compressor (2C) by switching of a third four-way selector valve (3C). The refrigeration system includes: a suction pressure detection section (81) for detecting the suction pressure of the first non-inverter compressor (2B) after the issue of a switching command to the third four-way selector valve (3C); a command holding section (82) for, when the detected pressure of the suction pressure detection section (81) becomes lower than a predetermined value, determining that the third four-way selector valve (3C) has malfunctioned and holding the switching command; and a compressor standby section (83) for, upon the command holding section (82) holding the switching command, stopping the first non-inverter compressor (2B) and putting it into standby for a predetermined time.

Abstract: A refrigeration apparatus (1) is provided with a refrigerant circuit (1E) along which are connected a compressor (2), an outdoor heat exchanger (4), an expansion mechanism, an indoor heat exchanger (41) for providing room air conditioning, and a cooling heat exchanger (45, 51) for providing storage compartment cooling. The refrigerant circuit (1E) includes a discharge side three way switch valve (101) for varying the flow rate of a portion of the refrigerant which is discharged out of the compressor (2) and then distributed to the indoor heat exchanger (41) and the outdoor heat exchanger (4) during a heat recovery operation mode in which the indoor heat exchanger (41) and the outdoor heat exchanger (4) operate as condensers. As a result of such arrangement, even when the amount of heat obtained in the cooling heat exchanger (45, 51) exceeds the amount of heat required in the indoor heat exchanger (41), surplus heat is discharged without excessive decrease in the discharge pressure of the compressor (2).

Abstract: A refrigeration apparatus (1) is disclosed which is provided with multiple systems of utilization-side heat exchangers (20, 30, 40) and in which liquid-side interunit piping lines (53, 54, 55) are combined into a single liquid-side interunit piping line in multiple systems of liquid lines. When the refrigeration apparatus (1) provides space heating of 100% heat recovery without the use of an outdoor heat exchanger (15), the flow of refrigerant in a refrigerant circuit (50) is stabilized even when the temperature of outside air is low, thereby preventing the capacity to provide refrigeration from decreasing.

Abstract: In a refrigerant circuit (20), an air conditioning unit (12), a cold-storage showcase (13), and a freeze-storage showcase (14) are connected in parallel to an outdoor unit (11). When placing an indoor heat exchanger (71) of the air conditioning unit (12) in the thermo-off state, a degree-of-opening control means (101) provides control so that an indoor expansion valve (72) is placed in the fully closed state. Thereafter, the degree-of-opening control means (101) detects the accumulated amount of refrigerant within the indoor heat exchanger (71) and then adjusts the degree of opening of the indoor expansion valve (72) depending on the refrigerant amount detected.

Abstract: In a store, a plurality of electric apparatuses including an air conditioner, a lighting apparatus, a water heater and a refrigeration unit are provided and connected to a single main power supply. An electric energy control system includes an electric energy detection part, an electric energy supervising part, an air conditioner derivation part and an air conditioner control part. The electric energy detection part detects the total electric energy consumption of the plurality of electric apparatuses. The electric energy supervising part outputs a demand signal when the total electric energy consumption detected by the electric energy detection part exceeds a set amount of electric energy.

Abstract: When a guard timer of a compressor (141) expires, an R2 signal from a control section (140) of an outdoor unit is turned on (Action I). If a control section (120) of a freezer unit recognizes from an inside temperature detected by a temperature sensor (124) that the R2 signal is turned on and a request for a shift to a freezer thermo-on state is raised (Action II), a freezer electromagnetic valve (121) is opened (Action III). In general, when the electromagnetic valve (121) is opened, it is supposed that an increase in refrigerant suction pressure is detected by a pressure sensor (146) and then the compressor (141) is actuated. However, if an outside air temperature is low, the refrigerant suction pressure remains lower than a predetermined value. Therefore, the control section (120) actuates a booster compressor (131) (Action IV) to raise the refrigerant suction pressure of the compressor (141).

Abstract: A refrigerant return mechanism (5) is provided for returning liquid refrigerant in a receiver (17) to a circulation path. Whereby, the liquid refrigerant in the receiver (17) is forcedly returned to the circulation path in an operation state where the circulation path is formed in which the refrigerant sent out from compression mechanism (11D, 11E) flows from a second user side unit (20) to first user side units (30, 40) and is then returned to the compression mechanisms (11D, 11E).

Abstract: A refrigerant circuit (20) includes a low stage compressor (101, 102, 121, 122), a high stage compressor (41, 42, 43), an outdoor heat exchanger (44) and a utilization side heat exchanger (83, 93). During a defrosting operation of the refrigeration system (10), the high stage compressor (41, 42, 43) is driven. Refrigerant discharged from the high stage compressor (41, 42, 43) is pumped into the utilization side heat exchanger (83, 93) to heat frost on it from its inside. Thereafter, the refrigerant evaporates in the outdoor heat exchanger (44), is then compressed by the high stage compressor (41, 42, 43) and is sent again to the utilization side heat exchanger (83, 93).

Abstract: A refrigeration apparatus (1) is provided with a refrigerant circuit (1E) along which are connected a compressor (2), an outdoor heat exchanger (4), an expansion mechanism, an indoor heat exchanger (41) for providing room air conditioning, and a cooling heat exchanger (45, 51) for providing storage compartment cooling. The refrigerant circuit (1E) includes a discharge side three way switch valve (101) for varying the flow rate of a portion of the refrigerant which is discharged out of the compressor (2) and then distributed to the indoor heat exchanger (41) and the outdoor heat exchanger (4) during a heat recovery operation mode in which the indoor heat exchanger (41) and the outdoor heat exchanger (4) operate as condensers. As a result of such arrangement, even when the amount of heat obtained in the cooling heat exchanger (45, 51) exceeds the amount of heat required in the indoor heat exchanger (41), surplus heat is discharged without excessive decrease in the discharge pressure of the compressor (2).

Abstract: In order that an indoor heat exchanger (41), a cold storage heat exchanger (45), and a freeze storage heat exchanger (51) may differ in their refrigerant evaporating temperature, a refrigerant circuit (1E) is provided with a suction side three way switching valve (102) capable of switching of flow paths between the heat exchangers (41, 45, 51) and a compressor (2).

Abstract: An outside air temperature sensor (231) for detecting the temperature of outside air, and a control means (240) for controlling the operating capacity of a supercool compressor (221) are provided. The control means (240) controls the operation of the supercool compressor (221) based on the state of refrigerant of a refrigerant circuit (20) flowing through a supercool heat exchanger (210) and the temperature of outside air detected by the outside air temperature sensor (231).

Abstract: A subcooling unit (200) includes a refrigerant passage (205) connected to liquid side communication pipes (21, 22) of a refrigerating apparatus (10). When a subcooling compressor (221) is operated, subcooling refrigerant circulates in a subcooling refrigerant circuit (220) to perform a refrigeration cycle, thereby cooling refrigerant of the refrigerating apparatus (10) which flows in the refrigerant passage (205). A controller (240) of the subcooling unit (200) receives the detection value of an outside air temperature sensor (231) or a refrigerant temperature sensor (236). The controller (240) controls the operation of the subcooling compressor (221) with the use of only information obtainable within the subcooling unit (200).

Abstract: The loss of refrigerant pressure which is caused in a return-side interconnecting piping line (19) comprising return-side interconnecting piping lines respectively extending from outlet ports (24, 34, 44) of single-stage side utilization units (12, 13, 14) to an inlet port (61) of a heat source unit (11) is set such that the lowest valued refrigerant pressure loss is caused by a said return-side interconnecting piping line of the return-side interconnecting piping line (19) that is connected to the lowest of the single-stage side utilization units (12, 13, 14) in compartment preset temperature.

Abstract: In a refrigeration system, a first non-inverter compressor (2B) backs up one of an inverter compressor (2A) and a second non-inverter compressor (2C) by switching of a third four-way selector valve (3C). The refrigeration system includes: a suction pressure detection section (81) for detecting the suction pressure of the first non-inverter compressor (2B) after the issue of a switching command to the third four-way selector valve (3C); a command holding section (82) for, when the detected pressure of the suction pressure detection section (81) becomes lower than a predetermined value, determining that the third four-way selector valve (3C) has malfunctioned and holding the switching command; and a compressor standby section (83) for, upon the command holding section (82) holding the switching command, stopping the first non-inverter compressor (2B) and putting it into standby for a predetermined time.

Abstract: In a refrigerant circuit (20), a refrigerator circuit (110) and a freezing circuit (30) are connected in parallel to an outdoor circuit (40). In the freezing circuit (30), a freezer circuit (130) and a booster circuit (140) are connected in series. A booster compressor (141) and a four-way switch valve (142) are provided in the booster circuit (140). During the time when a freezer heat exchanger (131) performs cooling operation for cooling the inside air, refrigerant evaporated in the freezer heat exchanger (131) is compressed in the booster compressor (141), and then, is sucked into a variable capacitance compressor (41). On the other hand, during defrosting of the freezer heat exchanger (131), the refrigerant evaporated in a refrigerator heat exchanger (111) is compressed in the booster compressor (141), and then, is supplied to the freezer heat exchanger (131).

Abstract: A pressure regulating valve (71) is connected to the discharge side of a low stage compressor (55) to make the pressure in the suction side of high stage compressors (11, 12) lower than the pressure in a dome of the low stage compressor (55). Further, an oil return path (72) is connected to the dome of the low stage compressor (55) at one end and to the suction side of the high stage compressors (11, 12) by bypassing the pressure regulating valve (71) at the other end. With this configuration, refrigeration oil accumulated in the dome of the low stage compressor (55) is returned to the high stage compressors (11, 12).

Abstract: A refrigeration system includes a controller (90) for controlling operation restart after a breaker trips owing to failure in electric systems for refrigeration system components. The controller (90) includes a sequential startup section (91) for, upon the operation restart, sequentially starting up target compressors (2A, 2B, 2C) and outdoor fans (F1, F2) previously selected from among the refrigeration system components, and failure processing section (92) for, if the breaker trips again during the sequential startup of the target compressors and outdoor fans, excluding the compressor or outdoor fan (2A, . . . ) supplied with electric power just before the breaker's trip from the target refrigeration system components to be started up by the sequential startup section (91). Thus, a failed component is identified by the failure processing section (92) and only the normal components, leaving out the failed component, are then started up, thereby resuming the operation.