Abstract: An icemaking system includes: a refrigerant circuit that executes a vapor compression refrigeration cycle; a circulation circuit that circulates solution as a cooling target of the refrigerant circuit; and a control device that controls refrigerant evaporation temperature at the refrigerant circuit. The circulation circuit includes a solution flow path of: an ice generator; a solution tank that stores the solution; and a pump that pressure feeds the solution to the solution flow path. The refrigerant circuit includes: an evaporator of the ice generator; a compressor; a condenser; and an expansion valve. The control device includes a central processing unit (CPU) that adjusts to lower evaporation temperature at the evaporator as the solution has higher solute concentration.

Abstract: Provided is a refrigeration apparatus with improved safety. A refrigeration apparatus includes: a compressor; a heat source-side expansion valve to be controlled to have a minimum opening degree and brought into a closed state in which the heat source-side expansion valve maximizes prevention of a flow of a refrigerant toward a usage-side refrigerant circuit; a fusible plug; a controller; and a refrigerant leak detector configured to detect a refrigerant leak at the usage-side refrigerant circuit. The fusible plug is disposed in a refrigerant circuit, and is brought into an open state to allow the refrigerant circuit to communicate with an external space. When the refrigerant leak detector detects a refrigerant leak at the usage-side refrigerant circuit, the controller performs refrigerant leak first control to bring the heat source-side expansion valve into the closed state, and performs refrigerant leak second control to bring the fusible plug into the open state.

Abstract: Provided is a refrigeration apparatus capable of reducing the leakage of a refrigerant even when a refrigerant leak occurs in a defrosting operation of a usage-side heat exchanger. When a refrigerant leak situation around a usage-side heat exchanger satisfies a predetermined leak condition in performing a defrosting operation with a connection state of a four-way switching valve brought into a defrosting connection state in which a heat source-side heat exchanger functions as an evaporator for a refrigerant and a usage-side heat exchanger functions as a radiator for the refrigerant, a controller performs density lowering control to lower a refrigerant density in the usage-side heat exchanger while maintaining the four-way switching valve at the defrosting connection state.

Abstract: Provided is a refrigeration apparatus that secures safety while suppressing an increase in cost. A refrigeration apparatus performs a refrigeration cycle in a refrigerant circuit including a compressor, a heat source-side heat exchanger, and a usage-side heat exchanger. The refrigeration apparatus comprises a usage-side fan providing an air flow, and a controller. The usage-side fan is disposed in a target space where inside air is cooled. The controller performs a refrigerant leak determination process to determine whether a refrigerant leak occurs, based on a state of a refrigerant in the refrigerant circuit. When the controller performs the refrigerant leak determination process to determine that a refrigerant leak occurs, then the controller performs leakage refrigerant agitation control to operate the usage-side fan so as to suppress local emergence of a region where the refrigerant leaks at a high concentration in the target space.

Abstract: Provided is a refrigeration apparatus capable of, even in occurrence of a refrigerant leak, suppressing the extent of the refrigerant leak in continuously operating a usage unit other than a usage unit at which the refrigerant leak occurs.

Abstract: A refrigeration system includes a plurality of utilization units provided for one air conditioning target space, a refrigerant leakage sensor that detects a leakage of the refrigerant in a lower part of the air conditioning target space, and a control unit. In a case where the refrigerant leakage sensor detects the refrigerant leakage, the control unit performs detection standby control on the utilization units such that the supply of the refrigerant to utilization-side heat exchangers is temporarily stopped. In a case where the refrigerant leakage is detected based on the state quantity of the refrigerant corresponding to the utilization units under the detection standby control, the control unit stops the use of the utilization unit in which the refrigerant leakage has been detected.

Abstract: An icemaking system includes: a refrigerant circuit that executes a vapor compression refrigeration cycle; a circulation circuit that circulates solution as a cooling target of the refrigerant circuit; and a control device that controls refrigerant evaporation temperature at the refrigerant circuit. The circulation circuit includes a solution flow path of: an ice generator; a solution tank that stores the solution; and a pump that pressure feeds the solution to the solution flow path. The refrigerant circuit includes: an evaporator of the ice generator; a compressor; a condenser; and an expansion valve. The control device includes a central processing unit (CPU) that adjusts to lower evaporation temperature at the evaporator as the solution has higher solute concentration.

Abstract: Provided is a refrigeration apparatus with improved safety. A refrigeration apparatus includes: a compressor; a heat source-side expansion valve to be controlled to have a minimum opening degree and brought into a closed state in which the heat source-side expansion valve maximizes prevention of a flow of a refrigerant toward a usage-side refrigerant circuit; a fusible plug; a controller; and a refrigerant leak detector configured to detect a refrigerant leak at the usage-side refrigerant circuit. The fusible plug is disposed in a refrigerant circuit, and is brought into an open state to allow the refrigerant circuit to communicate with an external space. When the refrigerant leak detector detects a refrigerant leak at the usage-side refrigerant circuit, the controller performs refrigerant leak first control to bring the heat source-side expansion valve into the closed state, and performs refrigerant leak second control to bring the fusible plug into the open state.

Abstract: A refrigeration apparatus includes: a usage-side expansion valve whose opening degree is changed in response to a change in a flow rate or a pressure of a refrigerant on the upstream side; a first expansion valve; and a controller. The controller exerts, in an oil recovery operation, an oil recovery first control on the first expansion valve to attain a first opening degree (an opening degree of increasing an opening degree of the usage-side expansion valve in relation to a reduction in the flow rate or the pressure of the refrigerant passing through the first expansion valve), to reduce the flow rate or the pressure of the refrigerant passing through the first expansion valve.

Abstract: Provided is a refrigeration apparatus that secures safety while suppressing an increase in cost. A refrigeration apparatus performs a refrigeration cycle in a refrigerant circuit including a compressor, a heat source-side heat exchanger, and a usage-side heat exchanger. The refrigeration apparatus comprises a usage-side fan providing an air flow, and a controller. The usage-side fan is disposed in a target space where inside air is cooled. The controller performs a refrigerant leak determination process to determine whether a refrigerant leak occurs, based on a state of a refrigerant in the refrigerant circuit. When the controller performs the refrigerant leak determination process to determine that a refrigerant leak occurs, then the controller performs leakage refrigerant agitation control to operate the usage-side fan so as to suppress local emergence of a region where the refrigerant leaks at a high concentration in the target space.

Abstract: A refrigeration system includes a plurality of utilization units provided for one air conditioning target space, a refrigerant leakage sensor that detects a leakage of the refrigerant in a lower part of the air conditioning target space, and a control unit. In a case where the refrigerant leakage sensor detects the refrigerant leakage, the control unit performs detection standby control on the utilization units such that the supply of the refrigerant to utilization-side heat exchangers is temporarily stopped. In a case where the refrigerant leakage is detected based on the state quantity of the refrigerant corresponding to the utilization units under the detection standby control, the control unit stops the use of the utilization unit in which the refrigerant leakage has been detected.

Abstract: Provided is a refrigeration apparatus capable of, even in occurrence of a refrigerant leak, suppressing the extent of the refrigerant leak in continuously operating a usage unit other than a usage unit at which the refrigerant leak occurs.

Abstract: Provided is a refrigeration apparatus capable of reducing the leakage of a refrigerant even when a refrigerant leak occurs in a defrosting operation of a usage-side heat exchanger. When a refrigerant leak situation around a usage-side heat exchanger satisfies a predetermined leak condition in performing a defrosting operation with a connection state of a four-way switching valve brought into a defrosting connection state in which a heat source-side heat exchanger functions as an evaporator for a refrigerant and a usage-side heat exchanger functions as a radiator for the refrigerant, a controller performs density lowering control to lower a refrigerant density in the usage-side heat exchanger while maintaining the four-way switching valve at the defrosting connection state.

Abstract: A scroll compressor includes a compression mechanism having fixed and orbiting scrolls engaged with each other to form a compression chamber. Each of the fixed and orbiting scrolls includes an end plate and a spiral wall-shaped wrap extending from the end plate. The fixed scroll has an injection port configured to communicate with the compression chamber through a communication passageway located in the fixed-side end plate. The orbiting-side wrap has a thick portion located at a position corresponding to the injection port and having an increasing tooth thickness portion. A tooth thickness of the increasing tooth thickness portion increases from a start of winding to an end of winding of the orbiting-side wrap. The thick portion has a thickness greater than or equal to a dimension of an opening of the injection port measured along a tooth thickness of the orbiting-side wrap.

Abstract: A scroll compressor includes a compression mechanism having fixed and orbiting scrolls engaged with each other to form a compression chamber. Each of the fixed and orbiting scrolls includes an end plate and a spiral wall-shaped wrap extending from the end plate. The fixed scroll has an injection port configured to communicate with the compression chamber through a communication passageway located in the fixed-side end plate. The orbiting-side wrap has a thick portion located at a position corresponding to the injection port and having an increasing tooth thickness portion. A tooth thickness of the increasing tooth thickness portion increases from a start of winding to an end of winding of the orbiting-side wrap. The thick portion has a thickness greater than or equal to a dimension of an opening of the injection port measured along a tooth thickness of the orbiting-side wrap.

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: 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 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.