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: For the supply of refrigeration oil accumulated in an oil return compressor (90a) into a higher stage compression mechanism (11), an oil sump in a discharge pressure space defined in the casing of the oil return compressor (90a) and the downstream side of an oil separator (94) are connected together through an oil return passageway (97). And, a pressure reducing means (93) for the reduction in pressure of refrigerant flowing towards the oil separator (94) from the oil return compression mechanism (90a) is disposed in place between the oil return compressor (90a) and the oil separator (94) in a discharge pipe (85) of a lower stage compression mechanism (90).

Abstract: A refrigeration system (1) includes first to third compressors (11a, 11b, 11c) connected in parallel and an oil separator for separating a refrigeration oil from a refrigerant discharged from the compressors (11a, 11b, 11c). A main suction pipe (55) in which a refrigerant to be sucked into the compressors (11a, 11b, 11c) flows includes a primary curved portion (101) and a primary branch element (102) assembled to part of the main suction pipe (55) downstream of a junction with an oil return pipe (71) for returning the refrigeration oil separated by the oil separator. The main suction pipe (55) is branched by the primary branch element (102) into a first suction pipe branch (61a) of the first compressor (11a) and a connecting suction pipe (56). In the primary branch element (102), the first suction pipe branch (61a) is at the bottommost position and the outermost position in the direction of a radius of curvature of the primary curved portion (101).

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: A refrigeration system includes a refrigerant circuit including a chilling expansion valve, a chilling heat exchanger, a compressor (11) and an outdoor heat exchanger connected in this order to operate a vapor compression refrigeration cycle. A suction pressure sensor (25) is mounted to a suction pipe (61) of the compressor (11) through a heat taking pipe (90). The heat taking pipe (90) is joined through a heat transfer member (91) to a discharge pipe (64) of the compressor (11). The length of the heat taking pipe (90) is set to a predetermined minimum length increasing with decreasing evaporation temperature in the chilling heat exchanger or a longer length.

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 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: 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: 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: 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 refrigerator circuit (110) and a freezing circuit (30) are connected to an outdoor circuit (40) in parallel in a refrigerant circuit (20), and a freezer circuit (130) and a booster circuit (140) are connected in series in the freezing circuit (30). The booster circuit (140) includes a booster compressor (141) and three-way switching mechanisms (142, 160). During cooling operation of a freezing heat exchanger (131), first operation is performed in the three-way switching mechanisms (142, 160) so that the refrigerant evaporated in the freezing heat exchanger (131) is compressed in the booster compressor (141) and is sucked into a variable capacity compressor (41).

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 the 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 a suction pressure sensor (234) and a refrigerant temperature sensor (236). The controller (240) utilizes input signals from the sensors (234, 236) to control driving operation of the subcooling compressor (221) on the basis of information obtained within the subcooling unit (200). Thus, the operation of the subcooling compressor (221) can be controlled without sending and receiving a singal to and from the refrigerating apparatus (10) to which the subcooling unit (200) is incorporated.

Abstract: A refrigerating apparatus including three compressors (2A, 2B, 2C) and application side heat exchangers (41) (45, 51) for two channels is formed so that a first compressor (2A) is used only for the application side heat exchangers (45, 51) in a first channel of a circuit, a third compressor (2C) is used only for the application side heat exchanger (41) in a second channel of the circuit, and a second compressor (2B) is used in a switchable manner between the application side heat exchangers (45, 51) in the first channel of the circuit and the application side heat exchanger (41) in the second channel of the circuit. Thus, not only the pipe arrangement at suction side is simplified, but also operation control is streamlined.

Abstract: In a refrigerating apparatus (1) having application-side heat exchangers (41, 45, 51) for a plurality of systems for air-conditioning, for cold-storage/freezing and the like and a four-way switch valve (3C) and a plurality of check valves (7) on suction sides of compression mechanisms (2D, 2E) and formed from three compressors (2A, 2B, 2C) to allow the operation states to be switched, the number of compressors (2A, 2B, 2C) used at air-conditioning side and cold-storage/freezing side is limited to two at maximum, thereby achieving a simple circuit configuration in which the number of the check valves (7) to be provided in the suction sides of the compression mechanisms (2D, 2E) is reduced to one or two, suppressing the occurrence of chattering noise in check valves (7) and, also, preventing an ability from reducing due to a suction-side pressure loss.

Abstract: A refrigerating apparatus including three compressors (2A, 2B, 2C) and application side heat exchangers (41) (45, 51) for two channels is formed so that a first compressor (2A) is used only for the application side heat exchangers (45, 51) in a first channel of a circuit, a third compressor (2C) is used only for the application side heat exchanger (41) in a second channel of the circuit, and a second compressor (2B) is used in a switchable manner between the application side heat exchangers (45, 51) in the first channel of the circuit and the application side heat exchanger (41) in the second channel of the circuit. Thus, not only the pipe arrangement at suction side is simplified, but also operation control is streamlined.

Abstract: In a refrigerating apparatus (1) having application-side heat exchangers (41, 45, 51) for a plurality of systems for air-conditioning, for cold-storage/freezing and the like and a four-way switch valve (3C) and a plurality of check valves (7) on suction sides of compression mechanisms (2D, 2E) and formed from three compressors (2A, 2B, 2C) to allow the operation states to be switched, the number of compressors (2A, 2B, 2C) used at air-conditioning side and cold-storage/freezing side is limited to two at maximum, thereby achieving a simple circuit configuration in which the number of the check valves (7) to be provided in the suction sides of the compression mechanisms (2D, 2E) is reduced to one or two, suppressing the occurrence of chattering noise in check valves (7) and, also, preventing an ability from reducing due to a suction-side pressure loss.