Control system, refrigeration system, and control method for refrigeration device

Abstract

A control unit (32) controls a refrigeration device (20). The refrigeration device (20) comprises a heat source unit (40) and a cooling unit (50). The cooling unit (50) comprises a storage (50a) and an evaporator (52), and executes or stops a cooling operation for cooling air in the storage (50a) in accordance with an internal temperature (Tsv), which is the temperature of the air in the storage (50a), and a set temperature (Tset). The control unit (32) outputs control information for controlling an operation of the heat source unit (40) on the basis of cooling status information that is information related to a cooling status of the storage (50a) in the cooling unit (50) and includes a temporal transition of the internal temperature (Tsv).

Description

Control System, Refrigeration System, and Control Method for Refrigeration Equipment

[0001] The present disclosure relates to a control system, a refrigeration system, and a control method for a refrigeration equipment.

[0002] Patent Document 1 discloses a refrigeration system including an outdoor unit, a showcase, and a controller control unit. A unit control unit is provided in the outdoor unit, and a showcase control unit is provided in the showcase.

[0003] The showcase control unit sends the detection values of various sensors such as an in-store temperature sensor to the controller control unit. Based on the detection values and the like sent from the showcase control unit, the controller control unit sends control signals to the unit control unit and the showcase control unit. The unit control unit performs drive control of the compressor. The showcase control unit performs opening degree control of an electronic expansion valve and the like.

[0004] Japanese Patent Application Laid-Open No. 2022-43465

[0005] In the refrigeration system as described above, from the viewpoint of optimizing the control of the heat source unit (the outdoor unit in Patent Document 1), it is desirable to be able to control the operation of the heat source unit based on the cooling status information including the "change over time of the in-store temperature", which is information regarding the cooling status of the storage in the cooling unit (the showcase in Patent Document 1). However, Patent Document 1 does not disclose or suggest anything about the change over time of the in-store temperature as described above.

[0006] A first aspect of the present disclosure relates to a control system applied to a refrigeration device (20) that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (25) composed of the heat source unit (40) having a compressor (42) and a heat sink (43), and a cooling unit (50) having a storage compartment (50a) and an evaporator (52) for cooling the air inside the storage compartment (50a), and which performs or stops a cooling operation to cool the air inside the storage compartment (50a) according to the storage compartment temperature (Tsv) and a set temperature (Tset), wherein the control system comprises a control unit (32) that controls the refrigeration device (20), The control unit (32) outputs control information for controlling the operation of the heat source unit (40) based on cooling status information, which is information regarding the cooling status of the storage compartment (50a) in the cooling unit (50) and includes the change in the temperature inside the compartment (Tsv) over time.

[0007] In the first embodiment, control information can be output that takes into account the cooling status of the storage compartment (50a) in the cooling unit (50) (particularly the change in internal temperature (Tsv) over time). Since the operation of the heat source unit (40) can be controlled based on such control information, the operation of the heat source unit (40) can be appropriately controlled according to the cooling status of the storage compartment (50a) in the cooling unit (50).

[0008] A second aspect of this disclosure is a control system in the first aspect, wherein the cooling status information includes a plurality of temperature values ​​that can derive the change in the internal temperature (Tsv) over time, and the set temperature (Tset).

[0009] In the second embodiment, the time-dependent changes in the internal temperature (Tsv) can be confirmed based on multiple temperature values. This allows for, for example, determining whether the internal temperature (Tsv) is decreasing, whether it is rapidly increasing, and whether it is stable. Furthermore, based on the time-dependent changes in the internal temperature (Tsv) and the set temperature (Tset), the time-dependent changes in the internal temperature (Tsv) relative to the set temperature (Tset) can be confirmed. This allows for, for example, determining whether the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset), and determining whether the cooling operation in the cooling unit (50) has stopped.

[0010] A third aspect of this disclosure is a control system in the second aspect, wherein the cooling status information includes the plurality of temperature values, the set temperature (Tset), and information regarding the status of the cooling operation in the cooling unit (50).

[0011] In the third embodiment, it is possible to determine whether or not the cooling operation has stopped based on information regarding the status of the cooling operation in the cooling unit (50).

[0012] A fourth aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), the compressor (42) is started, the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP) and a target low pressure (LPT), and when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), the compressor (42) is stopped, and the control information is a control system that includes at least one of first information for controlling the target low pressure (LPT), second information for controlling the second low pressure (LP2), and third information for controlling the rate of increase of the rotational speed (R) of the compressor (42).

[0013] In the fourth embodiment, the operation of the heat source unit (40) can be controlled by controlling at least one of the target low pressure (LPT), the second low pressure (LP2), and the rate of increase of the rotational speed (R) of the compressor (42).

[0014] A fifth aspect of the present disclosure is a control system of the fourth aspect, wherein in the cooling unit (50), the cooling operation is started when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and the cooling operation is stopped when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is the temperature corresponding to the set temperature (Tset) and lower than the start temperature (Ts1), and the control information is a control system that includes at least one of the first information, the second information, the third information, and the fourth information for controlling the start temperature (Ts1).

[0015] In the fifth embodiment, the fourth information is information for indirectly controlling the operation of the heat source unit (40). The operation of the heat source unit (40) can be controlled directly or indirectly by controlling at least one of the target low pressure (LPT), the second low pressure (LP2), the rate of increase of the rotational speed (R) of the compressor (42), and the starting temperature (Ts1).

[0016] A sixth aspect of the present disclosure is a control system in any one of the first to fifth aspects, wherein the control unit (32) selects a type corresponding to the cooling status information from among a plurality of types, each corresponding to a different cooling status of the storage compartment (50a), and outputs the control information based on the selected type.

[0017] In the sixth embodiment, the cooling status of the storage compartment (50a) in the cooling unit (50) can be classified into one of several types, thereby enabling smoother processing for outputting control information.

[0018] A seventh aspect of the present disclosure is a control system in the sixth aspect, wherein the control unit (32) outputs the control information based on a selected type and a control execution condition which includes a cooling condition that the type corresponds to a predetermined type, and is necessary for outputting the control information.

[0019] In the seventh embodiment, processing for outputting control information can be smoothly performed based on a type corresponding to the cooling status of the storage compartment (50a) in the cooling unit (50) and pre-prepared control implementation conditions.

[0020] An eighth aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP), which is the refrigerant pressure on the suction side of the compressor (42), and the target low pressure (LPT); in the cooling unit (50), the cooling operation is started when the internal temperature (Tsv) exceeds the start temperature (Ts1) corresponding to the set temperature (Tset), and the cooling operation is stopped when the internal temperature (Tsv) falls below the stop temperature (Ts2), which is the temperature corresponding to the set temperature (Tset) and lower than the start temperature (Ts1); and the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a first cooling status and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The first cooling state includes a state in which the cooling operation is stopped, or a state in which the internal temperature (Tsv) is stable within a range near the stop temperature (Ts2) as the lower limit, and the control information is a control system that includes information for increasing the target low pressure (LPT).

[0021] In the eighth embodiment, the operation of the heat source unit (40) is controlled based on control information including information for increasing the target low pressure (LPT), thereby increasing the target low pressure (LPT) and decreasing the rotational speed (R) of the compressor (42). This reduces the power consumption of the compressor (42).

[0022] A ninth aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), and the target low pressure (LPT); the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a second cooling status and a predetermined time has elapsed, which is a predetermined time before the closing time of the store where the cooling unit (50) is installed; the second cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) has not risen sharply; and the control information includes information for raising the target low pressure (LPT).

[0023] In the ninth embodiment, the operation of the heat source unit (40) is controlled based on control information including information for increasing the target low pressure (LPT), thereby increasing the target low pressure (LPT) and decreasing the rotational speed (R) of the compressor (42). This reduces the power consumption of the compressor (42).

[0024] A tenth aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), the compressor (42) starts when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), and the compressor (42) stops when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1); in the cooling unit (50), the cooling operation starts when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and the cooling operation stops when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is a temperature corresponding to the set temperature (Tset) and is lower than the start temperature (Ts1); The control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a third cooling status and the operating mode of the refrigeration device (20) is an operating mode that prioritizes reducing energy consumption. The third cooling status includes a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) is not rising rapidly. The control information is a control system that includes information for raising the start temperature (Ts1).

[0025] In the tenth embodiment, the operation of the cooling unit (50) is controlled based on control information including information for raising the starting temperature (Ts1), making it difficult to raise the starting temperature (Ts1) and start the cooling operation of the cooling unit (50). As a result, the low pressure (LP), which is the refrigerant pressure on the suction side of the compressor (42), is less likely to exceed the first low pressure (LP1), so the operating time of the compressor (42) in the heat source unit (40) can be shortened and the power consumption of the compressor (42) can be reduced.

[0026] An eleventh aspect of this disclosure relates to a control system in any one of the first to third aspects, wherein in the heat source unit (40), the compressor (42) starts when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), and the compressor (42) stops when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1); in the cooling unit (50), the cooling operation starts when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and the cooling operation stops when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is a temperature corresponding to the set temperature (Tset) and is lower than the start temperature (Ts1); The control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to the fourth cooling status and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed. The fourth cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is decreasing within a range near the stop temperature (Ts2) as the lower limit. The control information is a control system that includes information for increasing the second low pressure (LP2).

[0027] In the eleventh embodiment, the operation of the heat source unit (40) is controlled based on control information that includes information for increasing the second low pressure (LP2), making it easier to increase the second low pressure (LP2) and stop the compressor (42). As a result, the operating time of the compressor (42) in the heat source unit (40) can be shortened, and thus the power consumption of the compressor (42) can be reduced.

[0028] A twelfth aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), the compressor (42) is started, the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP) and the target low pressure (LPT), and when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), the compressor (42) is stopped, and the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a fifth cooling status and the cooling load in the cooling unit (50) is in a high load state. The high-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is shorter than a predetermined time, or the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, the fifth cooling state includes a state in which the internal temperature (Tsv) is rising rapidly, and the control information is a control system that includes information for increasing the rate of increase of the rotational speed (R) of the compressor (42).

[0029] In the twelfth embodiment, when the cooling status of the cooling unit (50) corresponds to the fifth cooling status and the cooling load on the cooling unit (50) is in a high-load state, the operation of the heat source unit (40) is controlled based on control information that includes information for increasing the rate at which the rotational speed (R) of the compressor (42) increases, thereby making it easier to stop the compressor (42). As a result, the operating time of the compressor (42) can be shortened, and thus the power consumption of the compressor (42) can be reduced.

[0030] A thirteenth aspect of this disclosure is a control system according to the twelfth aspect, wherein the heat source unit (40) has a heat source control unit (46) that starts the compressor (42) when the low pressure (LP) exceeds the first low pressure (LP1), controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT), and stops the compressor (42) when the low pressure (LP) falls below the second low pressure (LP2), and the heat source control unit (46) controls the rotational speed (R) of the compressor (42) such that the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase according to the difference between the low pressure (LP) and the target low pressure (LPT) when the control information output from the control unit (32) does not include information for increasing the rate of increase of the rotational speed (R) of the compressor (42), This control system controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase that is higher than the first rate of increase, when the control information output from the control unit (32) includes information for increasing the rate of increase of the rotational speed (R) of the compressor (42).

[0031] In the 13th embodiment, when the cooling load in the cooling unit (50) is in a high-load state (specifically, when the control information includes information to increase the rate at which the rotational speed (R) of the compressor (42) increases), the rate at which the rotational speed (R) of the compressor (42) increases can be increased. This shortens the operating time of the compressor (42), and thus reduces the power consumption of the compressor (42).

[0032] A fourteenth aspect of this disclosure is a control system in the thirteenth aspect, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT) corresponding to the target low pressure (LPT), and the predetermined amount (ΔR) when the cooling load is in a low load state is a first amount (ΔR1) corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), and the predetermined amount (ΔR) when the cooling load is in a high load state is a second amount (ΔR2) which is greater than the first amount (ΔR1).

[0033] In the 14th embodiment, when the cooling load in the cooling unit (50) is in a high load state, a predetermined amount (ΔR), which is the amount by which the rotational speed (R) of the compressor (42) increases per cycle, can be increased, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0034] A fifteenth aspect of this disclosure is a control system in the thirteenth aspect, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT), the predetermined amount (ΔR) is an amount corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), the target rotational speed (RT) when the cooling load is in a low load state is a first target rotational speed (RT1) corresponding to the target low pressure (LPT), and the target rotational speed (RT) when the cooling load is in a high load state is a second target rotational speed (RT2) which is higher than the first target rotational speed (RT1).

[0035] In the 15th embodiment, the target rotational speed (RT) can be increased when the cooling load in the cooling unit (50) is in a high-load state. This allows for a certain amount (ΔR), which is the amount of increase in the rotational speed (R) of the compressor (42) per cycle, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0036] A sixteenth aspect of this disclosure is a control system in any one of the thirteenth to fifteenth aspects, wherein the storage compartment (50a) is an open-type storage compartment (50a).

[0037] In the 16th embodiment, the cooling load in the open-type storage container (50a) tends to be higher than the cooling load in the closed-type storage container (50a). In this way, under conditions where the cooling load in the cooling unit (50) tends to be high, it is possible to appropriately perform processing to increase the rate at which the rotational speed (R) of the compressor (42) increases, thereby appropriately reducing the power consumption of the compressor (42).

[0038] A 17th aspect of the present disclosure is a control system in any one of the first to third aspects, wherein in the heat source unit (40), the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), and the target low pressure (LPT); the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a sixth cooling status; the sixth cooling status includes a situation in which the internal temperature (Tsv) is higher than a predetermined range including the set temperature (Tset); and the control information includes information for reducing the target low pressure (LPT).

[0039] In the 17th embodiment, the operation of the heat source unit (40) is controlled based on control information including information for reducing the target low pressure (LPT), thereby reducing the target low pressure (LPT) and increasing the rotational speed (R) of the compressor (42). This increases the capacity exerted by the heat source unit (40), thereby promoting the cooling of the storage chamber (50a) by the cooling operation of the cooling unit (50), and preventing the internal temperature (Tsv) from becoming too high.

[0040] A 18th aspect of the present disclosure is a control system in any one of the first to 17th aspects, wherein the refrigeration device (20) comprises the heat source unit (40) and a plurality of the cooling units (50), and the control unit (32) is a control system that outputs control information based on the cooling status information obtained from each of the plurality of cooling units (50).

[0041] In the 18th embodiment, control information can be output that takes into account the cooling status of the storage compartment (50a) in each of the multiple cooling units (50) (particularly the change in internal temperature (Tsv) over time). Since the operation of the heat source unit (40) can be controlled based on such control information, the operation of the heat source unit (40) can be appropriately controlled according to the cooling status of the storage compartment (50a) in each of the multiple cooling units (50).

[0042] A 19th aspect of the present disclosure relates to a refrigeration system, which comprises a control system according to any one of the first to 18th aspects and the refrigeration device (20).

[0043] A 20th aspect of the present disclosure relates to a control method for a refrigeration system (20) that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (25) composed of the heat source unit (40) and the cooling unit (50), the control method for the refrigeration system comprising: a heat source unit (40) having a compressor (42) and a heat sink (43); a cooling unit (50) having a storage compartment (50a) and an evaporator (52) for cooling the air inside the storage compartment (50a), and which performs or stops a cooling operation to cool the air inside the storage compartment (50a) according to the temperature inside the storage compartment (50a), which is the temperature of the air inside the storage compartment (50a), and a set temperature (Tset); and a control step of controlling the operation of the heat source unit (40) based on the cooling status information obtained in the acquisition step.

[0044] In the 20th aspect, control information considering the cooling status of the storage chamber (50a) in the cooling unit (50) (particularly the temporal change of the temperature inside the chamber (Tsv)) can be output. Thereby, the operation of the heat source unit (40) can be appropriately controlled according to the cooling status of the storage chamber (50a) in the cooling unit (50).

[0045] The 21st aspect of the present disclosure relates to a control method of a heat source unit having a storage chamber (50a) and an evaporator (52) for cooling the air inside the storage chamber (50a), and constituting a refrigerant circuit (25) that performs a refrigeration cycle by circulating a refrigerant together with a cooling unit (50) that executes or stops a cooling operation for cooling the air inside the storage chamber (50a) according to the temperature inside the storage chamber (Tsv) which is the temperature of the air inside the storage chamber (50a) and a set temperature (Tset), the heat source unit including a compressor (42) that sucks and compresses the refrigerant and a radiator (43) that radiates the refrigerant discharged from the compressor (42). The control method of this heat source unit includes a startup step of starting the compressor (42) when the low-pressure pressure (LP) which is the pressure of the refrigerant on the suction side of the compressor (42) exceeds a first low-pressure pressure (LP1), a control step of controlling the rotation speed (R) of the compressor (42) according to the difference between the low-pressure pressure (LP) and the target low-pressure pressure (LPT), and a stop step of stopping the compressor (42) when the low-pressure pressure (LP) falls below a second low-pressure pressure (LP2) which is lower than the first low-pressure pressure (LP1). In the control step, when the cooling load in the cooling unit (50) is in a low-load state, the rotation speed (R) of the compressor (42) is controlled so that the rising speed of the rotation speed (R) of the compressor (42) becomes a first rising speed corresponding to the difference between the low-pressure pressure (LP) and the target low-pressure pressure (LPT), and when the cooling load is in a high-load state, the rotation speed (R) of the compressor (42) is controlled so that the rising speed of the rotation speed (R) of the compressor (42) becomes a second rising speed higher than the first rising speed.

[0046] In the 21st aspect, when the cooling load in the cooling unit (50) is in a high load state, the rising speed of the rotational speed (R) of the compressor (42) can be increased. As a result, the operation time of the compressor (42) can be shortened, so that the power consumption of the compressor (42) can be reduced.

[0047] FIG. 1 is a piping system diagram illustrating the configuration of the refrigeration system of the embodiment. FIG. 2 is a block diagram illustrating the connection of the control system in the refrigeration system of the embodiment. FIG. 3 is a schematic diagram illustrating the configuration of the cooling unit. FIG. 4 is a flowchart illustrating the control of the compressor of the heat source unit. FIG. 5 is a flowchart illustrating the control of the cooling operation of the cooling unit. FIG. 6 is a flowchart illustrating the first part of the type determination process. FIG. 7 is a flowchart illustrating the second part of the type determination process. FIG. 8 is a flowchart illustrating the third part of the type determination process. FIG. 9 is a table illustrating the relationship between the "type related to the cooling situation" and the "content of the cooling situation". FIG. 10 is a table illustrating the correspondence relationship between the "control pattern", the "control execution conditions", and the "control information". FIG. 11 is a flowchart illustrating the cooling load determination process. FIG. 12 is a graph illustrating the first operation (low load) of the compressor control. FIG. 13 is a graph illustrating the second operation (high load) of the compressor control. FIG. 14 is a graph illustrating the first operation (low load) of the compressor control in a modification of the embodiment. FIG. 15 is a graph illustrating the second operation (high load) of the compressor control in a modification of the embodiment.

[0048] Hereinafter, embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions will not be repeated. Further, the present disclosure is not limited to the embodiments shown below, and various modifications can be made without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0049] (Embodiment) Figure 1 illustrates the configuration of a refrigeration system (10) according to an embodiment. The refrigeration system (10) comprises a refrigeration device (20) and a control system (30) applied to the refrigeration device (20).

[0050] [Refrigeration System] The refrigeration system (20) comprises a heat source unit (40) and a plurality of cooling units (50). The plurality of cooling units (50) have similar configurations to each other. The cooling units (50) constitute a cooling system such as a showcase, refrigerator, or freezer, and cool the inside of the cooling system. For example, the heat source unit (40) is installed outdoors. The cooling units (50) are installed indoors.

[0051] In this example, multiple cooling units (50) are installed inside a store. Examples of stores include supermarkets, food sections within department stores, and convenience stores. In this example, the store has set opening and closing times.

[0052] The heat source unit (40) comprises a heat source circuit (41), a heat source fan (45), and a heat source control unit (46). The heat source circuit (41) is provided with a compressor (42) and a heat source heat exchanger (43). Each of the multiple cooling units (50) comprises a utilization circuit (51), a utilization fan (55), and a utilization control unit (56). The utilization circuit (51) is provided with a utilization heat exchanger (52) and a utilization expansion valve (53).

[0053] The heat source circuit (41) of the heat source unit (40) and the utilization circuits (51) of the multiple cooling units (50) are connected by a gas connecting pipe (21) and a liquid connecting pipe (22). In this example, the utilization circuits (51) of the multiple cooling units (50) are connected in parallel to the heat source circuit (41) of the heat source unit (40). Specifically, the gas connecting pipe (21) is connected to the gas end of the heat source circuit (41), the liquid connecting pipe (22) is connected to the liquid end of the heat source circuit (41), the gas end of the utilization circuit (51) is connected to the gas connecting pipe (21), and the liquid end of the utilization circuit (51) is connected to the liquid connecting pipe (22).

[0054] In this way, the refrigerant circuit (25) is formed by connecting the heat source circuit (41) of the heat source unit (40) and the utilization circuits (51) of the multiple cooling units (50). The refrigerant circuit (25) includes the heat source unit (40) and the multiple cooling units (50). The refrigerant circuit (25) is filled with refrigerant. The refrigeration device (20) performs a refrigeration cycle by circulating the refrigerant in the refrigerant circuit (25).

[0055] <Compressor> The compressor (42) draws in refrigerant, compresses the drawn-in refrigerant, and discharges it. The inlet (suction pipe) of the compressor (42) is connected to one end of the gas connection pipe (21) through the refrigerant pipe. In this example, the compressor (42) has an electric motor and a compression mechanism that is rotationally driven by the electric motor. The compressor (42) is a variable displacement compressor whose rotational speed (operating frequency) can be adjusted. For example, the compressor (42) is a rotary compressor.

[0056] <Heat Source Fan> The heat source fan (45) is positioned near the heat source heat exchanger (43) and transports heat source air to the heat source heat exchanger (43). For example, the heat source air is outdoor air.

[0057] <Heat Source Heat Exchanger> The heat source heat exchanger (43) exchanges heat between the refrigerant flowing through the heat source heat exchanger (43) and the heat source air transported to the heat source heat exchanger (43). For example, the heat source heat exchanger (43) is a fin-and-tube type heat exchanger. The gas end of the heat source heat exchanger (43) is connected to the outlet (discharge pipe) of the compressor (42) through a refrigerant pipe. The liquid end of the heat source heat exchanger (43) is connected to one end of the liquid connecting pipe (22) through a refrigerant pipe. In this example, the heat source heat exchanger (43) functions as a heat radiator.

[0058] <Heat Source Sensor> The heat source unit (40) is equipped with a heat source sensor (60) that detects various physical quantities in each part of the heat source unit (40). For example, the heat source sensor (60) includes various sensors such as a pressure sensor and a temperature sensor. Examples of physical quantities detected by the heat source sensor (60) include the pressure and temperature of the high-pressure side (high-pressure refrigerant) of the refrigerant circuit (25), the pressure and temperature of the low-pressure side (low-pressure refrigerant) of the refrigerant circuit (25), the pressure and temperature of the refrigerant in the heat source heat exchanger (43), and the temperature of the air drawn into the heat source unit (40). The heat source sensor (60) transmits a detection signal indicating the detection result to the heat source control unit (46).

[0059] The heat source sensor (60) (the various sensors described above) may be a sensor provided to directly detect the physical quantities described above, or it may be a sensor provided to indirectly detect or estimate the physical quantities described above.

[0060] In this example, the heat source sensor (60) includes a low-pressure sensor (61), a rotational speed sensor (62), and the like. The low-pressure sensor (61) detects the low-pressure level (LP), which is the refrigerant pressure at the suction side of the compressor (42). The rotational speed sensor (62) detects the rotational speed (R) of the compressor (42).

[0061] <Heat Source Control Unit> The heat source control unit (46) is connected to each part of the heat source unit (40) by signal lines. As shown in Figure 2, in this example, the heat source control unit (46) is connected to the compressor (42), heat source fan (45), heat source sensor (60), etc. The heat source control unit (46) also receives signals (information and data) transmitted from outside the heat source unit (40). The heat source control unit (46) then controls each part of the heat source unit (40) based on the detection signal from the heat source sensor (60) and the signals transmitted from outside the heat source unit (40). This controls the operation of the heat source unit (40).

[0062] For example, the heat source control unit (46) consists of a processor, memory, input / output interfaces, etc. The memory is electrically connected to the processor and stores programs and data for operating the processor. The various functions of the heat source control unit (46) are realized when the programs are executed by the processor. The heat source control unit (46) also includes control components (e.g., electrical circuits and electronic circuits).

[0063] Furthermore, the memory of the heat source control unit (46) stores information and data used for controlling the heat source unit (40) (e.g., setting values ​​such as thresholds), information and data obtained by the heat source sensor (60) (e.g., measured values), and information and data obtained by processing by the heat source control unit (46) (e.g., processing results). The heat source unit (40) may also be provided with a memory unit (not shown) for storing this information.

[0064] <Utilization Fan> The utilization fan (55) is positioned near the utilization heat exchanger (52) and transports utilization air to the utilization heat exchanger (52). For example, the utilization air is the air inside the chamber.

[0065] <Utilizing Heat Exchanger> The utilizing heat exchanger (52) exchanges heat between the refrigerant flowing through the utilizing heat exchanger (52) and the utilizing air transported to the utilizing heat exchanger (52). For example, the utilizing heat exchanger (52) is a fin-and-tube type heat exchanger. The liquid end of the utilizing heat exchanger (52) is connected to the liquid connecting pipe (22) through the refrigerant pipe. The gas end of the utilizing heat exchanger (52) is connected to the gas connecting pipe (21) through the refrigerant pipe. In this example, the utilizing heat exchanger (52) functions as an evaporator.

[0066] <Utilization Expansion Valve> The utilization expansion valve (53) is installed in the refrigerant pipe between the liquid end of the utilization heat exchanger (52) and the liquid connecting pipe (22). The opening degree of the utilization expansion valve (53) is adjustable. For example, the utilization expansion valve (53) is an electrically operated valve.

[0067] <Utilization Sensors> The cooling unit (50) is equipped with utilization sensors (70) for detecting various physical quantities in each part of the cooling unit (50). For example, the utilization sensors (70) include various sensors such as pressure sensors and temperature sensors. Examples of physical quantities detected by the utilization sensors (70) include the pressure and temperature of the high-pressure side (high-pressure refrigerant) of the refrigerant circuit (25), the pressure and temperature of the low-pressure side (low-pressure refrigerant) of the refrigerant circuit (25), the pressure and temperature of the refrigerant in the utilization heat exchanger (52), and the temperature of the air drawn into the cooling unit (50). The utilization sensors (70) transmit detection signals indicating the detection results to the utilization control unit (56). This controls the operation of the cooling unit (50).

[0068] The sensors used (70) (the various sensors described above) may be sensors provided to directly detect the physical quantities described above, or they may be sensors provided to indirectly detect or estimate the physical quantities described above.

[0069] In this example, the utilization sensor (70) includes an intake temperature sensor (71), a discharge temperature sensor (72), and a superheat sensor (73). The superheat sensor (73) detects the degree of superheating of the refrigerant at the refrigerant outlet of the utilization heat exchanger (52). For example, the superheat sensor (73) has an inlet temperature sensor that detects the temperature of the refrigerant at the refrigerant inlet of the utilization heat exchanger (52) and an outlet temperature sensor that detects the temperature of the refrigerant at the refrigerant outlet of the utilization heat exchanger (52). The difference in refrigerant temperature detected by the inlet temperature sensor and the outlet temperature sensor corresponds to the degree of superheating of the refrigerant at the refrigerant outlet of the utilization heat exchanger (52). The intake temperature sensor (71) and the discharge temperature sensor (72) will be explained in detail later.

[0070] <Utilization Control Unit> The utilization control unit (56) is connected to each part of the cooling unit (50) by signal lines. As shown in Figure 2, the utilization control unit (56) is connected to the utilization expansion valve (53), utilization fan (55), utilization sensor (70), etc. The utilization control unit (56) also receives signals (information and data) transmitted from outside the cooling unit (50). The utilization control unit (56) then controls each part of the cooling unit (50) based on the detection signal from the utilization sensor (70) and the signals transmitted from outside the cooling unit (50).

[0071] For example, the utilization control unit (56) is composed of a processor, memory, input / output interfaces, etc. The memory is electrically connected to the processor and stores programs and data for operating the processor. The various functions of the utilization control unit (56) are realized when the processor executes the programs. The utilization control unit (56) also includes control components (e.g., electrical circuits and electronic circuits).

[0072] Furthermore, the memory of the utilization control unit (56) stores information and data used for controlling the cooling unit (50) (e.g., setting values ​​such as thresholds), information and data obtained by the utilization sensor (70) (e.g., measured values), and information and data obtained by processing by the utilization control unit (56) (e.g., calculation results). The cooling unit (50) may also be provided with a storage unit (not shown) for storing this information.

[0073] [Structure of the Cooling Unit] Figure 3 illustrates the structure of the cooling unit (50). In this example, the cooling unit (50) has a storage compartment (50a). The cooling unit (50) cools the "storage air," which is the air inside the storage compartment (50a), during its cooling operation. In this example, the storage compartment (50a) is an open-type storage compartment (50a).

[0074] The storage compartment (50a) has an internal space (50b) and an air passage (50c). The internal space (50b) is a space with one side (the front in this example) open. In this example, the internal space (50b) is provided with multiple shelves for displaying the contents stored in the internal space (50b). Examples of contents include frozen foods, meat, fresh fish, fruits and vegetables, and soft drinks.

[0075] The air passage (50c) has an intake port (50d) and an outlet port (50e) that open into the internal space (50b). The intake port (50d) and the outlet port (50e) are formed in the storage compartment (50a) along the periphery of the open surface of the internal space (50b). In this example, the intake port (50d) is formed at the bottom of the storage compartment (50a), and the outlet port (50e) is formed at the top of the storage compartment (50a).

[0076] A utilization fan (55) and a utilization heat exchanger (52) are arranged in the air passage (50c). The utilization fan (55) generates an airflow within the air passage (50c) that passes from the intake port (50d) through the utilization fan (55) and the utilization heat exchanger (52) to the outlet port (50e). As a result, air drawn from the interior space (50b) through the intake port (50d) into the air passage (50c) is cooled in the utilization heat exchanger (52), which acts as an evaporator, and then blown out from the air passage (50c) through the outlet port (50e) into the interior space (50b). In addition, an air curtain is formed on the open surface of the interior space (50b) by the airflow from the outlet port (50e) towards the intake port (50d).

[0077] The intake temperature sensor (71) is located near the intake port (50d) and detects the "intake temperature," which is the temperature of the air drawn from the interior space (50b) through the intake port (50d) into the air passage (50c). The discharge temperature sensor (72) is located near the discharge outlet (50e) and detects the "discharge temperature," which is the temperature of the air blown from the air passage (50c) through the discharge outlet (50e) into the interior space (50b).

[0078] [Internal Temperature and Set Temperature] Next, we will explain the terms "internal temperature (Tsv)" and "set temperature (Tset)" used in the following explanation.

[0079] The internal temperature (Tsv) corresponds to the temperature of the air inside the storage compartment (50a) that is being cooled by the cooling unit (50). In this example, the internal temperature (Tsv) is derived based on at least one of the intake temperature and the discharge temperature. For example, the internal temperature (Tsv) may be the average value of the intake temperature and the discharge temperature obtained at the same time, a weighted average value of the intake temperature and the discharge temperature, or the result of other calculations (the result of calculations using the intake temperature and the discharge temperature). Alternatively, the internal temperature (Tsv) may be the temperature detected by a temperature sensor (not shown) installed inside the storage compartment (50a). For example, the derivation of the internal temperature (Tsv) is performed by the control unit (32) and the utilization control unit (56), which will be described later.

[0080] The state of "stable internal temperature (Tsv)" means that the fluctuation range of the internal temperature (Tsv) within a predetermined period is relatively narrow, and the internal temperature (Tsv) can be considered constant. For example, this means that the fluctuation range of the internal temperature (Tsv) within a predetermined period is less than or equal to a predetermined range.

[0081] The condition "the internal temperature (Tsv) is rising rapidly" means that the internal temperature (Tsv) over a predetermined period of time shows an upward trend, and the amount of increase in the internal temperature (Tsv) over that period of time is relatively large (for example, the amount of increase exceeds a predetermined amount). Conversely, the condition where the internal temperature (Tsv) over a predetermined period of time shows an upward trend, but the amount of increase in the internal temperature (Tsv) over that period of time is relatively small (for example, the amount of increase is below a predetermined amount) corresponds to the condition "the internal temperature (Tsv) is on an upward trend."

[0082] The condition "the internal temperature (Tsv) is trending downwards" means that the internal temperature (Tsv) over a predetermined period of time shows a downward trend, but the amount of decrease in the internal temperature (Tsv) over that period is relatively small (for example, the amount of decrease is below a predetermined amount). Furthermore, the condition where the internal temperature (Tsv) over a predetermined period of time shows a downward trend AND the amount of decrease in the internal temperature (Tsv) over that period is relatively large (for example, the amount of decrease is above a predetermined amount) corresponds to the condition "the internal temperature (Tsv) is rapidly decreasing."

[0083] The set temperature (Tset) is the target value for the internal temperature (Tsv). The set temperature (Tset) can be set by the user. The set temperature (Tset) may be set individually for each cooling unit (50). The set temperature (Tset) is stored in the memory of the user control unit (56).

[0084] [Control of the compressor in the heat source unit] Next, with reference to Figure 4, the control of the compressor (42) of the heat source unit (40) will be explained. In the heat source unit (40), the following process is repeatedly performed.

[0085] <Step (S11)> The heat source control unit (46) determines whether the low pressure (LP) detected by the low pressure sensor (61) exceeds the first low pressure (LP1). For example, the first low pressure (LP1) is set to the low pressure (LP) at which it can be considered that the low pressure (LP) has risen due to the execution of a cooling operation in at least one cooling unit (50). The first low pressure (LP1) is stored in the memory of the heat source control unit (46). If the low pressure (LP) exceeds the first low pressure (LP1), the process in step (S12) is performed.

[0086] <Step (S12): Startup Step> When the low pressure (LP) exceeds the first low pressure (LP1), the heat source control unit (46) starts the compressor (42). As a result, the rotational speed (R) of the compressor (42) increases.

[0087] <Step (S13): Low-Pressure Control (Control Step)> The heat source control unit (46) controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT). Specifically, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the low pressure (LP) approaches the target low pressure (LPT). For example, the target low pressure (LPT) is a pressure corresponding to a predetermined target evaporation temperature (target value of evaporation temperature in the refrigerant circuit (25)), and the lower the target evaporation temperature, the lower the target low pressure (LPT). The target evaporation temperature may be set by the user.

[0088] <Step (S14)> The heat source control unit (46) determines whether the low pressure (LP) falls below a predetermined second low pressure (LP2). The second low pressure (LP2) is lower than the first low pressure (LP1). For example, the second low pressure (LP2) is set to the low pressure (LP) at which it can be considered that the cooling operation has stopped in all cooling units (50). The second low pressure (LP2) is stored in the memory of the heat source control unit (46). If the low pressure (LP) falls below the second low pressure (LP2), the process in step (S15) is performed.

[0089] <Step (S15): Stop step> When the low pressure (LP) falls below the second low pressure (LP2), the heat source control unit (46) stops the compressor (42). As a result, the rotational speed (R) of the compressor (42) becomes zero.

[0090] [Control of Cooling Operation in Cooling Unit] Next, with reference to Figure 5, the control of the cooling operation of the cooling unit (50) will be explained. The following processes are repeatedly performed in the cooling unit (50).

[0091] <Step (S21)> The user control unit (56) determines whether the internal temperature (Tsv) exceeds the start temperature (Ts1). The start temperature (Ts1) is a temperature corresponding to the set temperature (Tset), and is set, for example, to set temperature (Tset) + rd [°C]. "rd" is a differential value which is the difference between the start temperature (Ts1) and the set temperature (Tset) that has been set in advance. The differential value may be set by the user. The start temperature (Ts1) is stored in the memory of the user control unit (56). If the internal temperature (Tsv) exceeds the start temperature (Ts1), the process in step (S22) is performed.

[0092] <Step (S22): Start Step> When the internal temperature (Tsv) exceeds the start temperature (Ts1), the utilization control unit (56) starts the cooling operation. Specifically, the utilization control unit (56) switches the utilization expansion valve (53) from the closed state to the open state and starts the utilization fan (55). As a result, refrigerant flows into the utilization heat exchanger (52), and the air passing through the utilization heat exchanger (52) (air flowing through the air passage (50c)) is cooled.

[0093] <Step (S23): Superheat Control (Opening Control Step)> The utilization control unit (56) controls the opening of the utilization expansion valve (53) according to the difference between the superheat detected by the superheat sensor (73) and the target superheat. Specifically, the utilization control unit (56) controls the opening of the utilization expansion valve (53) so that the superheat approaches the target superheat.

[0094] <Step (S24)> The usage control unit (56) determines whether the internal temperature (Tsv) falls below the stop temperature (Ts2). The stop temperature (Ts2) is a temperature corresponding to the set temperature (Tset) and is lower than the start temperature (Ts1). For example, the stop temperature (Ts2) is set to the set temperature (Tset). The stop temperature (Ts2) is stored in the memory of the usage control unit (56). If the internal temperature (Tsv) falls below the stop temperature (Ts2), the process in step (S25) is performed.

[0095] <Step (S25): Stop step> When the internal temperature (Tsv) falls below the stop temperature (Ts2), the utilization control unit (56) stops the cooling operation. Specifically, the utilization control unit (56) switches the utilization expansion valve (53) from the open state to the closed state and stops the utilization fan (55). As a result, refrigerant stops flowing to the utilization heat exchanger (52), and the cooling of the air in the utilization heat exchanger (52) stops.

[0096] [Control System] The control system (30) controls the refrigeration system (10). In this example, the control system (30) comprises a memory unit (31) and a control unit (32). The memory unit (31) and the control unit (32), which are components of the control system (30), are collectively housed in a single control device (not shown) that controls the refrigeration system (10).

[0097] <Memory Unit> The memory unit (31) stores various information and data related to the refrigeration system (10). Specifically, the memory unit (31) stores information and data used for controlling the refrigeration system (10) (e.g., setting values ​​such as thresholds and conditions for control), information and data input from outside the refrigeration system (10) (e.g., setting of operating modes), information related to the heat source unit (40), information related to each of the multiple cooling units (50), and information and data obtained by processing by the control unit (32) (e.g., processing results). For example, the memory unit (31) is composed of an HDD (Hard Disk Drive), RAM (Random Access Memory), SSD (Solid State Drive), etc.

[0098] Information relating to the heat source unit (40) includes information and data used for controlling the heat source unit (40) (e.g., set values ​​such as thresholds), information and data obtained by the heat source sensor (60) (e.g., measured values), and information and data obtained by processing by the heat source control unit (46) (e.g., processing results). Information relating to the cooling unit (50) includes information and data used for controlling the cooling unit (50) (e.g., set values ​​such as thresholds), information and data obtained by the utilization sensor (70) (e.g., measured values), and information and data obtained by processing by the utilization control unit (56) (e.g., calculation results).

[0099] The information and data stored in the memory unit (31) may be information and data entered by the user, information and data automatically collected by the control unit (32), information and data automatically transmitted from the heat source control unit (46) included in the heat source unit (40), information and data automatically transmitted from the utilization control unit (56) included in each of the multiple cooling units (50), or new information and data generated based on this information and data (for example, information and data obtained by machine learning).

[0100] <Control Unit> The control unit (32) controls the refrigeration device (20). In this example, the control unit (32) is connected to each part of the refrigeration system (10) by signal lines. As shown in Figure 2, the control unit (32) is connected to the storage unit (31), the heat source control unit (46), the utilization control unit (56), and so on. The control unit (32) also receives signals (information and data) input from outside the refrigeration system (10). Based on the information obtained from each part of the refrigeration system (10) and the signals input from outside the refrigeration system (10), the control unit (32) controls the refrigeration system (10), including the refrigeration device (20).

[0101] For example, the control unit (32) consists of a processor, memory, input / output interfaces, etc. The memory is electrically connected to the processor and stores programs and data for operating the processor. The various functions of the control unit (32) are realized when the program is executed by the processor.

[0102] The control unit (32) acquires "cooling status information," which is information regarding the cooling status of the storage compartment (50a) in the cooling unit (50), and outputs "control information," which is information for controlling the operation of the heat source unit (40) based on the acquired cooling status information. The cooling status information includes the change in the internal temperature (Tsv) over time. The cooling status information acquired from the cooling unit (50) is stored in the storage unit (31). The cooling status information and control information will be described in detail later.

[0103] The processing performed by the control unit (32) is an example of a method for controlling the refrigeration device (20). The process of "acquiring cooling status information" by the control unit (32) is an example of an acquisition step for acquiring cooling status information, and the process of "controlling the operation of the heat source unit (40)" by the control unit (32) is an example of a control step for controlling the operation of the heat source unit (40).

[0104] The control unit (32) acquires cooling status information from each of the multiple cooling units (50) and outputs control information based on that cooling status information. In this example, the control unit (32) selects a type from among several types, each corresponding to a different cooling status of the storage compartment (50a), that corresponds to the cooling status information obtained from the cooling unit (50), and outputs control information based on the selected type. The types will be explained in detail later.

[0105] [Cooling Status Information] In this example, the cooling status information includes multiple temperature values ​​from which the change in internal temperature (Tsv) over time can be derived, the set temperature (Tset), and information regarding the status of the cooling operation in the cooling unit (50). Hereafter, the information regarding the status of the cooling operation in the cooling unit (50) will be referred to as "operation status information".

[0106] Multiple temperature values ​​are arranged in chronological order. Each of the multiple temperature values ​​is associated with a time corresponding to that temperature value (for example, the time when the temperature value was obtained). Examples of temperature values ​​include the measured suction temperature obtained by the suction temperature sensor (71), the measured discharge temperature obtained by the discharge temperature sensor (72), the calculated internal temperature (Tsv) derived based on the measured suction temperature and the measured discharge temperature, and the measured internal temperature (Tsv) obtained by a temperature sensor (not shown) installed in the storage chamber (50a).

[0107] In this example, the refrigerant status information includes multiple temperature values, specifically "multiple measured intake temperatures arranged in chronological order" and "multiple measured discharge temperatures arranged in chronological order." The refrigerant status information may also include multiple temperature values, specifically "multiple calculated internal temperatures (Tsv) arranged in chronological order."

[0108] The operating status information indicates whether the cooling operation in the cooling unit (50) is "running" or "stopped." For example, the operating status information includes a flag indicating whether or not the cooling operation is being performed. Specifically, the operating status information may include a flag indicating whether or not the utilization expansion valve (53) is in the open state. If the utilization expansion valve (53) is in the open state, the cooling operation can be considered to be running, and if the utilization expansion valve (53) is in the closed state, the cooling operation can be considered to be stopped. By referring to the operating status information, it is possible to check whether the cooling operation in the cooling unit (50) is running or stopped.

[0109] [Control Information] The control information includes at least one of the following: first information, second information, third information, and fourth information. The first information is for controlling the target low pressure (LPT). The second information is for controlling the second low pressure (LP2). The third information is for controlling the rate at which the rotational speed (R) of the compressor (42) increases. The fourth information is for controlling the starting temperature (Ts1). The fourth information is also for indirectly controlling the operation of the heat source unit (40).

[0110] The control information includes commands for the heat source control unit (46) or the utilization control unit (56) to perform various controls. The control information may also include control quantities for parameters in the various controls. Examples of control quantities for parameters include the increase in target low pressure (LPT), the increase in start-up temperature (Ts1), the increase in second low pressure (LP2), and the decrease in target low pressure (LPT).

[0111] [Processing in the Refrigeration System] The refrigeration system (10) performs various processes, including cooling status determination processing and control processing. The cooling status determination processing is a process for determining the cooling status of the storage compartment (50a) in one or more cooling units (50) based on cooling status information obtained from each of the cooling units (50). Hereinafter, the cooling status of the storage compartment (50a) in a cooling unit (50) will be simply referred to as "cooling status of the cooling unit (50)". The control processing is a process for outputting control information based on the cooling status of the cooling unit (50) determined in the cooling status determination processing. In this example, the cooling status determination processing and the control processing are performed by the control unit (32).

[0112] [Cooling Status Determination Process] In the cooling status determination process, the control unit (32) determines the type of one or more cooling units (50) based on the cooling status information obtained from each cooling unit (50). Specifically, the control unit (32) selects the "type corresponding to the cooling status information obtained from the cooling unit (50)" from among a plurality of pre-prepared types (a plurality of types, each corresponding to a different cooling status).

[0113] Next, the cooling status determination process will be explained with reference to Figures 6, 7, and 8. The control unit (32) periodically performs the following process for each of the one or more cooling units (50) based on the cooling status information obtained from that cooling unit (50). In this example, nine types (Types 1 to 9) shown in Figure 9 are prepared. In the following process, the type of cooling unit (50) is determined (selected) from the Type 1 to 9 shown in Figure 9.

[0114] <Step (S31)> The control unit (32) determines whether or not a cooling operation is being performed in the cooling unit (50). If a cooling operation is being performed, the process in step (S32) is performed; otherwise, the process in step (S35) is performed.

[0115] In this example, the control unit (32) determines that the cooling operation is being performed if the operation status information included in the cooling status information indicates that "the cooling operation is being performed," and determines that the cooling operation is not being performed (the cooling operation has stopped) if the operation status information indicates that "the cooling operation is not being performed."

[0116] <Step (S32)> When the cooling operation is being performed in the cooling unit (50), the control unit (32) determines whether the internal temperature (Tsv) exceeds the lower limit temperature (TLth). For example, the internal temperature (Tsv) is set based on the latest value (current value) of multiple temperature values ​​included in the cooling status information. If the internal temperature (Tsv) exceeds the lower limit temperature (TLth), the process in step (S33) is performed; otherwise, the process in step (S36) is performed.

[0117] In this example, the internal temperature (Tsv) in step (S32) is set to the latest (current) value of the discharge temperature. The control unit (32) determines whether the latest value of the discharge temperature exceeds the lower limit temperature (TLth). For example, the lower limit temperature (TLth) is a temperature set to determine whether or not low-temperature damage occurs inside the storage chamber (50a), and is set to a temperature slightly higher than the temperature at which low-temperature damage is considered to occur (the lowest temperature at which low-temperature damage is considered not to occur). The lower limit temperature (TLth) may be set to -5 ± α [°C], where α is a value that can be set by the user.

[0118] <Step (S33)> If the internal temperature (Tsv) exceeds the lower limit temperature (TLth), the control unit (32) determines whether the internal temperature (Tsv) falls below the upper limit temperature (TUth). If the internal temperature (Tsv) falls below the upper limit temperature (TUth), the process in step (S34) is performed; otherwise, the process in step (S37) is performed.

[0119] In this example, the internal temperature (Tsv) in step (S33) is set to the latest (current) value of the suction temperature. For example, the upper limit temperature (TUth) is set to determine whether the internal temperature (Tsv) is getting too high, and is set to a temperature slightly lower than the temperature at which the internal temperature (Tsv) is considered to be getting too high (the highest temperature at which the internal temperature (Tsv) is considered not to be getting too high). The upper limit temperature (TUth) may also be set to the set temperature (Tset) + 5 ± α [°C].

[0120] <Step (S34)> If the internal temperature (Tsv) falls below the upper limit temperature (TUth), the control unit (32) determines whether the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset). If the internal temperature (Tsv) is within the predetermined range, the process in step (S41) (see Figure 7) is performed; otherwise, the process in step (S51) (see Figure 8) is performed.

[0121] In this example, the internal temperature (Tsv) in step (S34) is the temperature derived based on the latest values ​​of the intake temperature and the discharge temperature. For example, the internal temperature (Tsv) is set to the average value of the latest values ​​of the intake temperature and the discharge temperature. The upper limit of the predetermined range may be set to the set temperature (Tset) + rd + 1 [°C]. "rd" is a differential value which is the difference between the start temperature (Ts1) and the set temperature (Tset) that has been set in advance. The lower limit of the predetermined range may be set to the lower limit temperature (TLth).

[0122] <Step (S35)> If the cooling operation was not performed in step (S31), the control unit (32) determines the type of the cooling unit (50) to be "Type 1". Type 1 corresponds to the situation in which the cooling operation has stopped.

[0123] <Step (S36)> If the internal temperature (Tsv) in step (S32) is below the lower limit temperature (TLth), the control unit (32) determines the type of cooling unit (50) to be "Type 7". Type 7 is the type that corresponds to a situation where the internal temperature (Tsv) has become too low.

[0124] <Step (S37)> If the internal temperature (Tsv) in step (S33) is equal to or higher than the upper limit temperature (TUth), the control unit (32) determines the type of cooling unit (50) to be "Type 4". Type 4 is the type that corresponds to a situation where the internal temperature (Tsv) has become too high.

[0125] <Step (S41)> As shown in Figure 7, if the internal temperature (Tsv) in step (S34) is within a predetermined range, the control unit (32) determines whether the internal temperature (Tsv) is trending downwards. If the internal temperature (Tsv) is trending downwards, the process in step (S42) is performed; otherwise, the process in step (S45) is performed.

[0126] In this example, it is determined whether the internal temperature (Tsv) is trending downwards as follows. First, the control unit (32) detects the "latest value," the "temperature value obtained 5 seconds before the latest value," the "temperature value obtained 10 seconds before the latest value," and the "temperature value obtained 15 seconds before the latest value" from among the multiple temperature values ​​included in the cooling status information.

[0127] Next, the control unit (32) derives the following based on the above temperature values: "the latest internal temperature (Tsv)", "the value 5 seconds prior to the latest internal temperature (Tsv)", "the value 10 seconds prior to the latest internal temperature (Tsv)", and "the value 15 seconds prior to the latest internal temperature (Tsv)".

[0128] Next, the control unit (32) determines whether the following conditions for a decreasing temperature are met: the internal temperature (Tsv) 5 seconds ago is higher than the current internal temperature (Tsv), the internal temperature (Tsv) 10 seconds ago is higher than the internal temperature (Tsv) 5 seconds ago, and the internal temperature (Tsv) 15 seconds ago is higher than the internal temperature (Tsv) 10 seconds ago. The control unit (32) then determines that the internal temperature (Tsv) is decreasing if the above conditions for a decreasing temperature are met, and determines that the internal temperature (Tsv) is not decreasing if the above conditions for a decreasing temperature are not met.

[0129] <Step (S42)> If the internal temperature (Tsv) is decreasing, the control unit (32) determines whether the internal temperature (Tsv) is within a nearby range with the stop temperature (Ts2) as the lower limit. If the internal temperature (Tsv) is within the nearby range, the process in step (S43) is performed; otherwise, the process in step (S44) is performed.

[0130] The proximity range is the range of internal temperatures (Tsv) that can be considered to be near the stop temperature (Ts2). For example, the upper limit of the proximity range is set to stop temperature (Ts2) + 0.5 [°C]. When the stop temperature (Ts2) is set to the "set temperature (Tset)", the proximity range is set to a range with the "set temperature (Tset)" as the lower limit and the "set temperature (Tset) + 0.5 [°C]" as the upper limit.

[0131] <Step (S43)> If the internal temperature (Tsv) is decreasing and the internal temperature (Tsv) is within a range near the lower limit of the stop temperature (Ts2), the control unit (32) determines the type of cooling unit (50) to be "Type 9". Type 9 is the type that corresponds to a situation in which the internal temperature (Tsv) is decreasing and the cooling operation is about to stop.

[0132] <Step (S44)> If the internal temperature (Tsv) in step (S42) is not within the nearby range, the control unit (32) determines the type of cooling unit (50) to be "Type 3". Type 3 is the type that corresponds to a situation in which the internal temperature (Tsv) is decreasing.

[0133] <Step (S45)> If the internal temperature (Tsv) is not decreasing in step (S41), the control unit (32) determines, similar to step (S42), whether the internal temperature (Tsv) is within the vicinity range with the stop temperature (Ts2) as the lower limit. If the internal temperature (Tsv) is within the vicinity range, the process in step (S46) is performed; otherwise, the process in step (S47) is performed.

[0134] <Step (S46)> If the internal temperature (Tsv) is not decreasing and is within the same range, the control unit (32) determines the type of cooling unit (50) to be "Type 8". Type 8 is the type that corresponds to a situation where the internal temperature (Tsv) is stable and the cooling operation is about to stop.

[0135] <Step (S47)> If the internal temperature (Tsv) in step (S45) is not within the nearby range, the control unit (32) determines whether the internal temperature (Tsv) is rising rapidly. If the internal temperature (Tsv) is rising rapidly, the process in step (S48) is performed; otherwise, the process in step (S49) is performed.

[0136] In this example, it is determined whether the internal temperature (Tsv) is rising rapidly as follows: First, the control unit (32) detects the "latest value," the "temperature value obtained 15 seconds before the latest value," the "temperature value obtained 30 seconds before the latest value," and the "temperature value obtained 60 seconds before the latest value" from among the multiple temperature values ​​included in the cooling status information.

[0137] Next, the control unit (32) derives the "latest internal temperature (Tsv)" based on the above temperature values, the "value 15 seconds prior to the latest internal temperature (Tsv)", the "value 30 seconds prior to the latest internal temperature (Tsv)", and the "value 60 seconds prior to the latest internal temperature (Tsv)".

[0138] Next, the control unit (32) determines whether at least one of the following conditions is met: the first rapid rise condition, where "the internal temperature (Tsv) 15 seconds ago + 0.5 [°C]" is lower than the current internal temperature (Tsv); the second rapid rise condition, where "the internal temperature (Tsv) 30 seconds ago + 0.5 [°C]" is lower than the current internal temperature (Tsv); and the third rapid rise condition, where "the internal temperature (Tsv) 60 seconds ago + 0.5 [°C]" is lower than the current internal temperature (Tsv). The control unit (32) then determines that the internal temperature (Tsv) is rapidly rising if at least one of the first to third rapid rise conditions is met, and determines that the internal temperature (Tsv) is not rapidly rising if none of the first to third rapid rise conditions are met.

[0139] <Step (S48)> If the internal temperature (Tsv) is rising rapidly, the control unit (32) determines the type of cooling unit (50) to be "Type 5". Type 5 is the type that corresponds to the situation where the internal temperature (Tsv) is rising rapidly.

[0140] <Step (S49)> If the internal temperature (Tsv) has not risen sharply in step (S47), the control unit (32) determines the type of cooling unit (50) to be "Type 2". Type 2 corresponds to a situation where the internal temperature (Tsv) is stable.

[0141] <Step (S51)> As shown in Figure 8, if the internal temperature (Tsv) in step (S34) is not within a predetermined range, the control unit (32) determines whether the internal temperature (Tsv) is rising rapidly, similar to step (S47). If the internal temperature (Tsv) is rising rapidly, the process in step (S52) is performed; otherwise, the process in step (S53) is performed.

[0142] <Step (S52)> If the internal temperature (Tsv) rises sharply in step (S51), the control unit (32) determines the type of cooling unit (50) to be "Type 5".

[0143] <Step (S53)> If the internal temperature (Tsv) has not risen sharply in step (S51), the control unit (32) determines the type of cooling unit (50) to be "Type 6". Type 6 is the type that corresponds to a situation where the inside of the storage chamber (50a) is not very cold.

[0144] [Control Processing] Control processing is performed based on the cooling status of one or more cooling units (50) determined by the cooling status determination processing (in this example, the type corresponding to the cooling status). In this example, one or more control patterns are prepared for the implementation of control processing. Each of the one or more control patterns is associated with control information and control implementation conditions, which are the conditions for implementing control (output of control information). The control patterns, control information, and control implementation conditions are stored in the storage unit (31).

[0145] The control implementation conditions include cooling status conditions. The cooling status conditions are those in which the cooling status of each of the one or more cooling units (50) (or at least one of the one or more cooling units (50)) meets a predetermined cooling status. Whether to target "each of the one or more cooling units (50)" or "at least one of the one or more cooling units (50)" is determined for each control pattern. The predetermined cooling status is determined for each control pattern.

[0146] In this example, the cooling condition is that each of the one or more cooling units (50) (or at least one of the one or more cooling units (50)) belongs to a predetermined type. The predetermined type is defined for each control pattern.

[0147] Furthermore, the control implementation conditions may include predetermined conditions defined for each control pattern. Note that among multiple control implementation conditions, there may be control implementation conditions where no predetermined conditions are defined, and only cooling condition conditions are defined. Examples of predetermined conditions include drive conditions related to the drive capacity of the heat source unit (40), such as the rotational speed (R) of the compressor (42); time conditions related to the closing time of the store where the cooling unit (50) is installed; setting conditions related to the setting of the operating mode, such as the energy-saving mode (an operating mode that prioritizes reducing energy consumption); and load conditions related to the cooling load of the cooling unit (50).

[0148] In the control process, the control unit (32) outputs control information associated with one or more control patterns based on the success or failure of the control execution conditions associated with each of the one or more control patterns. Specifically, the control unit (32) monitors the success or failure of the control execution conditions associated with each of the one or more control patterns, and when a control execution condition associated with any of the control patterns is met, it outputs control information associated with that control pattern.

[0149] In the heat source unit (40), the heat source control unit (46) receives control information output from the control unit (32) and controls the operation of the heat source unit (40) by controlling each part of the heat source unit (40) (specifically the compressor (42)) based on that control information.

[0150] In each of the one or more cooling units (50), the utilization control unit (56) receives control information output from the control unit (32) and controls the operation of the cooling unit (50) by controlling each part of the cooling unit (50) (specifically, the utilization expansion valve (53)) based on that control information.

[0151] In this example, six control patterns (control patterns 1 to 6) shown in Figure 10 are prepared. Next, referring to Figure 10, the processing associated with each of the control patterns 1 to 6 will be explained.

[0152] [Processing related to the first control pattern] The first control pattern is associated with the first control execution conditions and control information that includes "information for increasing the target low pressure (LPT)". The information for increasing the target low pressure (LPT) is an example of the first information for controlling the target low pressure (LPT).

[0153] The first control execution conditions include a cooling condition in which the cooling status of one or more cooling units (50) corresponds to the "first cooling status," and a predetermined condition in which the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The latest value (current value) of the rotational speed (R) of the compressor (42) is transmitted from the heat source unit (40) and stored in the storage unit (31).

[0154] The first cooling condition includes a situation in which the cooling operation is stopped, or a situation in which the internal temperature (Tsv) is stable within a range near the stop temperature (Ts2) as the lower limit. In this example, the cooling condition is that each type of one or more cooling units (50) corresponds to either "Type 1" or "Type 8".

[0155] Furthermore, if the cooling conditions in one or more cooling units (50) correspond to the first cooling conditions, and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)) can be considered to be higher than the capacity required for the heat source unit (40). In such cases, it is possible to reduce the capacity exerted by the heat source unit (40).

[0156] When the control execution conditions associated with the first control pattern are met, the control unit (32) outputs control information to the heat source unit (40) that includes information for increasing the target low pressure (LPT) associated with the first control pattern. In other words, the control unit (32) outputs control information that includes information for increasing the target low pressure (LPT) when the cooling status in each of one or more cooling units (50) corresponds to the first cooling status and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed.

[0157] In the heat source unit (40), the heat source control unit (46) changes the target low pressure (LPT) to increase the target low pressure (LPT) based on the control information (information for increasing the target low pressure (LPT)) output from the control unit (32). Then, the heat source control unit (46) performs low pressure control (processing step (S13) shown in Figure 4) using the changed target low pressure (LPT). This makes it possible to reduce the rotational speed of the compressor (42) in low pressure control, and as a result, the power consumption of the compressor (42) can be reduced.

[0158] [Processing related to the second control pattern] The second control pattern is associated with the second control execution conditions and control information that includes "information for increasing the target low pressure (LPT)". The information for increasing the target low pressure (LPT) is an example of the first information for controlling the target low pressure (LPT).

[0159] The second control implementation conditions include a cooling condition in which the cooling status of one or more cooling units (50) corresponds to the "second cooling status," and a predetermined time that has elapsed, which is a predetermined time before the closing time of the store where one or more cooling units (50) are installed. For example, the predetermined time is one hour. The store's closing time is stored in the memory unit (31).

[0160] The second cooling condition includes a situation where the cooling operation has stopped, or a situation where the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) is not rising rapidly. In this example, the cooling condition is that each type of one or more cooling units (50) falls under one of the following categories: "Type 1", "Type 2", "Type 3", "Type 8", and "Type 9".

[0161] Furthermore, if the cooling status of one or more cooling units (50) corresponds to the second cooling status, and a predetermined time (a predetermined time before the closing time of the store where the cooling units (50) are installed) has elapsed, it can be considered that the store is about to close, the cooling load on the cooling units (50) has decreased, and the capacity required of the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)) has decreased. In such a case, it is possible to reduce the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)).

[0162] When the control execution conditions associated with the second control pattern are met, the control unit (32) outputs "control information including information for increasing the target low pressure (LPT)" associated with the second control pattern to the heat source unit (40). In other words, the control unit (32) outputs control information including information for increasing the target low pressure (LPT) when the cooling status in each of one or more cooling units (50) corresponds to the second cooling status and the predetermined time described above has elapsed.

[0163] In the heat source unit (40), the heat source control unit (46) changes the target low pressure (LPT) to increase the target low pressure (LPT) based on the control information (information for increasing the target low pressure (LPT)) output from the control unit (32). Then, the heat source control unit (46) performs low pressure control (processing step (S13) shown in Figure 4) using the changed target low pressure (LPT). This makes it possible to reduce the rotational speed of the compressor (42) in low pressure control, and as a result, the power consumption of the compressor (42) can be reduced.

[0164] [Processing related to the third control pattern] The third control pattern is associated with the conditions for executing the third control and control information that includes "information for raising the startup temperature (Ts1) in the cooling unit (50)". The information for raising the startup temperature (Ts1) is an example of the fourth information for controlling the startup temperature (Ts1).

[0165] The third control implementation conditions include a cooling status condition in which the cooling status of at least one of the one or more cooling units (50) corresponds to the "third cooling status," and a predetermined condition in which the operating mode of the refrigeration system (20) is an operating mode that prioritizes reducing energy consumption (energy-saving mode). Information indicating the operating mode of the refrigeration system (20) (information indicating which mode the operating mode of the refrigeration system (20) is set to) is stored in the storage unit (31).

[0166] The third cooling condition includes a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) is not rising rapidly. In this example, the cooling condition is that at least one of the cooling units (50) among one or more cooling units (50) is of one of the "second type", "third type", "eighth type", or "ninth type".

[0167] Furthermore, if the cooling condition of at least one of the cooling units (50) corresponds to the third cooling condition, and the operating mode of the refrigeration system (20) is an operating mode that prioritizes reducing energy consumption, it is possible to reduce the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)).

[0168] When the control execution conditions associated with the third control pattern are met, the control unit (32) outputs "control information including information for raising the start temperature (Ts1)" associated with the third control pattern to "a cooling unit (50) whose cooling status corresponds to the third cooling status" among one or more cooling units (50). In other words, the control unit (32) outputs control information including information for raising the start temperature (Ts1) when the cooling status of at least one of the one or more cooling units (50) corresponds to the third cooling status, and the operating mode of the refrigeration system (20) is energy-saving mode. The information for raising the start temperature (Ts1) is information for indirectly controlling the operation of the heat source unit (40) so as to shorten the operating time of the compressor (42).

[0169] In one or more cooling units (50), specifically in the "cooling unit (50) whose cooling status corresponds to the third cooling status," the utilization control unit (56) changes the starting temperature (Ts1) to increase the starting temperature (Ts1) based on the control information (information for increasing the starting temperature (Ts1)) output from the control unit (32). This makes it more difficult to start the cooling operation. As a result, the low pressure (LP) is less likely to exceed the first low pressure (LP1), thus shortening the operating time of the compressor (42) in the heat source unit (40) and reducing the power consumption of the compressor (42).

[0170] [Processing related to the fourth control pattern] The fourth control pattern is associated with the conditions for executing the fourth control and control information that includes "information for increasing the second low pressure (LP2)". The information for increasing the second low pressure (LP2) is an example of the second information for controlling the second low pressure (LP2).

[0171] The fourth control execution conditions include a cooling condition in which the cooling status of each of one or more cooling units (50) corresponds to the "fourth cooling condition," and a predetermined condition in which the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed. The latest value (current value) of the rotational speed (R) of the compressor (42) is transmitted from the heat source unit (40) and stored in the storage unit (31).

[0172] The fourth cooling condition includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is decreasing within a range near the stop temperature (Ts2) as the lower limit. In this example, the cooling condition is that each type of one or more cooling units (50) corresponds to either "Type 1" or "Type 9".

[0173] Furthermore, if the cooling condition in each of one or more cooling units (50) corresponds to the fourth cooling condition, and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed (for example, the minimum rotational speed), it is possible to reduce the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)).

[0174] When the control execution conditions associated with the fourth control pattern are met, the control unit (32) outputs "control information including information for increasing the second low pressure (LP2)" associated with the fourth control pattern to the heat source unit (40). In other words, the control unit (32) outputs control information including information for increasing the second low pressure (LP2) when the cooling status in each of one or more cooling units (50) corresponds to the fourth cooling status and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed.

[0175] In the heat source unit (40), the heat source control unit (46) changes the second low pressure (LP2) to increase the second low pressure (LP2) based on the control information (information for increasing the second low pressure (LP2)) output from the control unit (32). This shortens the operating time of the compressor (42), and as a result, reduces the power consumption of the compressor (42).

[0176] [Processing related to the fifth control pattern] The fifth control pattern is associated with the fifth control implementation conditions and control information that includes "information for increasing the rate of increase of the rotational speed (R) of the compressor (42)". The information for increasing the rate of increase of the rotational speed (R) of the compressor (42) is an example of information for controlling the rate of increase of the rotational speed (R) of the compressor (42).

[0177] The fifth control implementation conditions include a cooling condition in which the cooling status of each of the one or more cooling units (50) corresponds to the "fifth cooling condition," and a predetermined condition in which the cooling load of each of the one or more cooling units (50) is in a high-load state. The high-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is shorter than a predetermined time, or a state in which the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed.

[0178] Information indicating the operating status of the compressor (42) (information indicating whether the compressor (42) is running or stopped) and the latest value (current value) of the compressor (42) rotational speed are transmitted from the heat source unit (40) and stored in the storage unit (31). Furthermore, the "cooling load in each of the one or more cooling units (50)" mentioned above is the sum of the cooling loads in each of the one or more cooling units (50) connected to the heat source unit (40).

[0179] The fifth cooling condition includes a situation in which the internal temperature (Tsv) is rapidly increasing. In this example, the cooling condition is that each type of one or more cooling units (50) falls under the "fifth type".

[0180] Furthermore, if the cooling status of one or more cooling units (50) corresponds to the fifth cooling status, and the cooling load in one or more cooling units (50) is in a high-load state, it is desirable to shorten the operating time of the compressor (42) by increasing the rate at which the rotational speed (R) of the compressor (42) increases in order to reduce the power consumption of the compressor (42).

[0181] When the control execution conditions associated with the fifth control pattern are met, the control unit (32) outputs control information to the heat source unit (40) that includes information for increasing the rate at which the rotational speed (R) of the compressor (42) increases, which is associated with the fifth control pattern. In other words, the control unit (32) outputs control information that includes information for increasing the rate at which the rotational speed (R) of the compressor (42) increases when the cooling status in each of one or more cooling units (50) corresponds to the fifth cooling status, and the cooling load in each of one or more cooling units (50) is in a high load state.

[0182] In the heat source unit (40), the heat source control unit (46) controls the compressor (42) to increase the rate at which the rotational speed (R) of the compressor (42) increases, based on the control information (information for increasing the rate at which the rotational speed (R) of the compressor (42) increases) output from the control unit (32). This shortens the operating time of the compressor (42), and as a result, reduces the power consumption of the compressor (42). The control related to the rate at which the rotational speed (R) of the compressor (42) increases (compressor control) will be explained in detail later.

[0183] [Processing related to the sixth control pattern] The sixth control pattern is associated with the sixth control implementation conditions and control information that includes "information for reducing the target low pressure (LPT)". The information for reducing the target low pressure (LPT) is the first information for controlling the target low pressure (LPT). The sixth control implementation conditions include a cooling status condition in which the cooling status of at least one of the one or more cooling units (50) corresponds to the "sixth cooling status".

[0184] The sixth cooling condition includes a situation in which the internal temperature (Tsv) is higher than a predetermined range that includes the set temperature (Tset). In this example, the cooling condition is that at least one of the one or more cooling units (50) is of type "fourth type" or "sixth type".

[0185] Furthermore, if the cooling status of at least one of the one or more cooling units (50) corresponds to the sixth cooling status, the internal temperature (Tsv) may become too high. In such cases, it is desirable to prevent the internal temperature (Tsv) from becoming too high.

[0186] When the control execution conditions associated with the sixth control pattern are met, the control unit (32) outputs control information to the heat source unit (40) that includes information for reducing the target low pressure (LPT), which is associated with the sixth control pattern. In other words, the control unit (32) outputs control information that includes information for reducing the target low pressure (LPT) when the cooling status of at least one of the cooling units (50) among the one or more cooling units (50) corresponds to the sixth cooling status.

[0187] In the heat source unit (40), the heat source control unit (46) modifies the target low pressure (LPT) based on the control information (information for lowering the target low pressure (LPT)) output from the control unit (32). Then, the heat source control unit (46) performs low pressure control (processing step (S13) shown in Figure 4) using the modified target low pressure (LPT). This allows the rotational speed of the compressor (42) in low pressure control to be increased, thereby increasing the capacity exerted by the heat source unit (40). As a result, the cooling operation in the cooling unit (50) can be promoted to cool the storage chamber (50a), preventing the internal temperature (Tsv) from becoming too high.

[0188] [Cooling Load Determination Process] In the refrigeration system (10), a cooling load determination process is performed. The cooling load determination process is a process for determining whether the cooling load in one or more cooling units (50) is in a low load state or a high load state. In this example, the low load state is a state in which the stop duration, which is the time from when the compressor (42) stops until when the compressor (42) starts, is longer than a predetermined time, and the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed. The high load state is a state in which the stop duration is shorter than a predetermined time, or the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The cooling load determination process is performed by the control unit (32).

[0189] The cooling load determination process is a process for determining whether the "predetermined condition that the cooling load in each of the one or more cooling units (50) is in a high-load state" included in the fifth control execution conditions associated with the fifth control pattern is met.

[0190] Furthermore, the "cooling load in one or more cooling units (50)" mentioned above is the sum of the cooling loads in each of the one or more cooling units (50) connected to the heat source unit (40). Hereafter, the cooling load in one or more cooling units (50) will be referred to as the "connected load".

[0191] Next, the cooling load determination process will be explained with reference to Figure 11. For example, when the compressor (42) stops, the control unit (32) starts measuring the duration of the stop. Then, when the compressor (42) starts up, the control unit (32) stops measuring the duration of the stop and performs the following processing.

[0192] <Step (S61)> The control unit (32) determines whether the stop duration obtained by measurement is equal to or greater than a predetermined time. If the stop duration is longer than the predetermined time, the process in step (S62) is performed; otherwise, the process in step (S64) is performed.

[0193] <Step (S62)> If the stop duration is longer than a predetermined time, the control unit (32) determines whether the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed. The predetermined rotational speed is the rotational speed (R) of the compressor (42) when the connected load is relatively low, for example, the minimum rotational speed. If the rotational speed (R) of the compressor (42) is less than or equal to the predetermined rotational speed, the process in step (S63) is performed; otherwise, the process in step (S64) is performed.

[0194] <Step (S63)> If the duration of the stop is longer than a predetermined time and the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed, the control unit (32) determines that the connected load is in a "low load state".

[0195] <Step (S64)> If the duration of the stop is shorter than a predetermined time, or if the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, the control unit (32) determines that the connected load is in a "high load state".

[0196] [Compressor Control] Compressor control is performed in the heat source unit (40). Compressor control is a process for controlling the rotational speed (R) of the compressor (42). In this example, compressor control is performed by the heat source control unit (46). The processing by the heat source control unit (46) is an example of a control method for the heat source unit (40). In compressor control, the heat source control unit (46) selectively performs a first operation and a second operation according to the connected load.

[0197] If the connected load determined by the cooling load determination process is in a "low load state", the heat source control unit (46) performs a first operation. In the first operation, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase corresponding to the difference between the low pressure (LP) and the target low pressure (LPT). Specifically, the smaller the difference between the low pressure (LP) and the target low pressure (LPT), the lower the first rate of increase becomes. The rate of increase of the rotational speed (R) of the compressor (42) is the amount of increase in the rotational speed (R) of the compressor (42) within a predetermined period.

[0198] If the connection load determined by the cooling load determination process is in a "high load state", the heat source control unit (46) performs a second operation. In the second operation, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase that is higher than the first rate of increase. For example, the second rate of increase is greater than or equal to the maximum rate of the first rate of increase, which changes according to the difference between the low pressure (LP) and the target low pressure (LPT).

[0199] As shown in Figures 12 and 13, in compressor control, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT) corresponding to the target low pressure (LPT).

[0200] In the examples in Figures 12 and 13, one of the following numbers, "3," "4," or "5," is assigned to the predetermined amount (ΔR) to facilitate visual identification. The larger the predetermined amount (ΔR), the larger the number assigned to that predetermined amount (ΔR).

[0201] As shown in Figure 12, the predetermined amount (ΔR) in the first operation (when the connected load is in a low load state) is a first amount (ΔR1) corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT). Specifically, the larger the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), the larger the first amount (ΔR1).

[0202] In this example, in the first operation, the heat source control unit (46) repeatedly performs the following operation until the rotational speed (R) of the compressor (42) reaches the target rotational speed (RT): "determine a first amount (ΔR1) based on the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), and control the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by the determined first amount (ΔR1)."

[0203] As shown in Figure 13, the predetermined amount (ΔR) in the second operation (when the connected load is in a high-load state) is a second amount (ΔR2) which is greater than the first amount (ΔR1). For example, the second amount (ΔR2) is greater than or equal to the maximum amount of the first amount (ΔR1), which changes according to the difference between the low pressure (LP) and the target low pressure (LPT).

[0204] In this example, the second quantity (ΔR2) is set to the maximum amount of the first quantity (ΔR1). In the second operation, the heat source control unit (46) repeatedly performs the operation of "controlling the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by the second quantity (ΔR2)" until the rotational speed (R) of the compressor (42) reaches the target rotational speed (RT).

[0205] In the second operation, the predetermined amount (ΔR), which is the amount by which the rotational speed (R) of the compressor (42) increases per cycle, can be increased compared to the first operation, thus increasing the rate at which the rotational speed (R) of the compressor (42) increases. As a result, the operating time of the compressor (42) in the second operation (the length of time from start to stop in the waveform shown by the solid line in Figure 13) can be shortened compared to the operating time of the compressor (42) in the first operation (the length of time from start to stop in the waveform shown by the dashed line in Figure 13).

[0206] In the compressor control, the first operation corresponds to the control of the compressor (42) when the fifth control implementation condition associated with the fifth control pattern is not met. The second operation corresponds to the control of the compressor (42) when the fifth control implementation condition associated with the fifth control pattern is met. In this example, the heat source control unit (46) performs the first operation if the control information output from the control unit (32) does not include "information (e.g., a command) to increase the rate of increase of the rotational speed (R) of the compressor (42)", and performs the second operation if the control information output from the control unit (32) includes "information to increase the rate of increase of the rotational speed (R) of the compressor (42)".

[0207] [Effects of the Embodiment] As described above, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information for controlling the operation of the heat source unit (40) based on cooling status information, which is information regarding the cooling status of the storage compartment (50a) in the cooling unit (50) and includes the change in the internal temperature (Tsv) over time.

[0208] In the above configuration, the cooling unit (50) can output control information that takes into account the cooling status of the storage compartment (50a) (especially the change in internal temperature (Tsv) over time). Since the operation of the heat source unit (40) can be controlled based on such control information, the operation of the heat source unit (40) can be appropriately controlled according to the cooling status of the storage compartment (50a) in the cooling unit (50).

[0209] Furthermore, in the refrigeration system (10) of the embodiment, the cooling status information includes a plurality of temperature values ​​that can be used to derive the change in the internal temperature (Tsv) over time, and a set temperature (Tset).

[0210] In the above configuration, the time-series changes in the internal temperature (Tsv) can be checked based on multiple temperature values. This allows for, for example, determining whether the internal temperature (Tsv) is decreasing, whether it is rapidly increasing, and whether it is stable. Furthermore, based on the time-series changes in the internal temperature (Tsv) and the set temperature (Tset), the time-series changes in the internal temperature (Tsv) relative to the set temperature (Tset) can be checked. This allows for, for example, determining whether the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset), and determining whether the cooling operation in the cooling unit (50) has stopped.

[0211] Furthermore, in the refrigeration system (10) of the embodiment, the cooling status information includes a plurality of temperature values, a set temperature (Tset), and information regarding the status of the cooling operation in the cooling unit (50).

[0212] In the above configuration, it is possible to determine whether or not the cooling operation has stopped based on information regarding the status of the cooling operation in the cooling unit (50).

[0213] Furthermore, in the refrigeration system (10) of the embodiment, the control information includes at least one of the following: first information for controlling the target low pressure (LPT), second information for controlling the second low pressure (LP2), and third information for controlling the rate of increase of the rotational speed (R) of the compressor (42).

[0214] In the above configuration, the operation of the heat source unit (40) can be controlled by controlling at least one of the following: the target low pressure (LPT), the second low pressure (LP2), and the rate of increase in the rotational speed (R) of the compressor (42).

[0215] Furthermore, in the refrigeration system (10) of the embodiment, the control information includes at least one of the first information, second information, third information, and fourth information for controlling the start temperature (Ts1). The fourth information is information for indirectly controlling the operation of the heat source unit (40).

[0216] In the above configuration, the operation of the heat source unit (40) can be controlled directly or indirectly by controlling at least one of the following: the target low pressure (LPT), the second low pressure (LP2), the rate at which the rotational speed (R) of the compressor (42) increases, and the starting temperature (Ts1).

[0217] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) selects a type from among a plurality of types, each corresponding to a different cooling condition of the storage compartment (50a), that corresponds to the cooling condition information obtained from the cooling unit (50), and outputs control information based on the selected type.

[0218] In the above configuration, the cooling status of the storage compartment (50a) in the cooling unit (50) can be classified into one of several types, thereby enabling smooth processing for outputting control information.

[0219] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information based on a type selected from among a plurality of types (a type corresponding to the cooling status information obtained from the cooling unit (50)) and a control execution condition which includes a cooling status condition that the type corresponds to a predetermined type, and is necessary for outputting control information.

[0220] In the above configuration, processing for outputting control information can be carried out smoothly based on a type corresponding to the cooling status of the storage compartment (50a) in the cooling unit (50) and pre-prepared control implementation conditions.

[0221] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to a first cooling status and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The first cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is stable within a nearby range with the stop temperature (Ts2) as the lower limit. The control information includes information for increasing the target low pressure (LPT).

[0222] In the above configuration, if the cooling state of the cooling unit (50) corresponds to the first cooling state, and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)) can be considered to be higher than the capacity required of the heat source unit (40). In such cases, by controlling the operation of the heat source unit (40) based on control information that includes information for increasing the target low pressure (LPT), the target low pressure (LPT) can be increased and the rotational speed (R) of the compressor (42) can be decreased. This makes it possible to reduce the power consumption of the compressor (42).

[0223] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to a second cooling status, and a predetermined time has elapsed, which is a predetermined time before the closing time of the store where the cooling unit (50) is installed. The second cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) is not rising rapidly. The control information includes information for increasing the target low pressure (LPT).

[0224] In the above configuration, if the cooling status of the cooling unit (50) corresponds to the second cooling status, and a predetermined time (a predetermined time before the closing time of the store where the cooling unit (50) is installed) has elapsed, it can be considered that the store is about to close, the cooling load on the cooling unit (50) has decreased, and the capacity required of the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)) has decreased. In such a case, by controlling the operation of the heat source unit (40) based on control information that includes information for increasing the target low pressure (LPT), the target low pressure (LPT) can be increased and the rotational speed (R) of the compressor (42) can be decreased. This makes it possible to reduce the power consumption of the compressor (42).

[0225] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to a third cooling status, and the operating mode of the refrigeration device (20) is an operating mode that prioritizes reducing energy consumption. The third cooling status includes a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset), and the internal temperature (Tsv) is not rising rapidly. The control information includes information for raising the start temperature (Ts1). The information for raising the start temperature (Ts1) is information for indirectly controlling the operation of the heat source unit (40) so as to shorten the operating time of the compressor (42).

[0226] In the above configuration, if the cooling status of the cooling unit (50) corresponds to the third cooling status, and the operating mode of the refrigeration system (20) is an operating mode that prioritizes reducing energy consumption, it is possible to reduce the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)). In such cases, by controlling the operation of the cooling unit (50) based on control information that includes information for raising the starting temperature (Ts1), it is possible to raise the starting temperature (Ts1) and make it more difficult to start the cooling operation of the cooling unit (50). As a result, the low pressure (LP), which is the refrigerant pressure on the suction side of the compressor (42), is less likely to exceed the first low pressure (LP1), so the operating time of the compressor (42) in the heat source unit (40) can be shortened, and the power consumption of the compressor (42) can be reduced.

[0227] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs the control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to the fourth cooling status and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed. The fourth cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is decreasing within a range near the stop temperature (Ts2) as the lower limit. The control information includes information for increasing the second low pressure (LP2).

[0228] In the above configuration, when the cooling state of the cooling unit (50) corresponds to the fourth cooling state, and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed (e.g., the minimum rotational speed), it is possible to reduce the capacity exerted by the heat source unit (40) (specifically, the rotational speed (R) of the compressor (42)). In such cases, by controlling the operation of the heat source unit (40) based on control information that includes information for increasing the second low pressure (LP2), it is possible to increase the second low pressure (LP2) and make it easier to stop the compressor (42). As a result, the operating time of the compressor (42) in the heat source unit (40) can be shortened, and thus the power consumption of the compressor (42) can be reduced.

[0229] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to the fifth cooling status and the cooling load in the cooling unit (50) is in a high-load state. The high-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is shorter than a predetermined time, or a state in which the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The fifth cooling status includes a state in which the internal temperature (Tsv) is rapidly rising. The control information includes information for increasing the rate of increase of the rotational speed (R) of the compressor (42).

[0230] In the above configuration, when the cooling status of the cooling unit (50) corresponds to the fifth cooling status and the cooling load on the cooling unit (50) is in a high-load state, the operation of the heat source unit (40) is controlled based on control information that includes information for increasing the rate at which the rotational speed (R) of the compressor (42) increases, making it easier to stop the compressor (42). This shortens the operating time of the compressor (42), thereby reducing the power consumption of the compressor (42).

[0231] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information when the cooling status derived based on the cooling status information of the cooling unit (50) corresponds to a sixth cooling status. The sixth cooling status includes a situation in which the internal temperature (Tsv) is higher than a predetermined range including the set temperature (Tset). The control information includes information for reducing the target low pressure (LPT).

[0232] In the above configuration, if the cooling status of the cooling unit (50) corresponds to the sixth cooling status, the internal temperature (Tsv) may become too high. In such cases, the operation of the heat source unit (40) can be controlled based on control information that includes information for lowering the target low pressure (LPT), thereby lowering the target low pressure (LPT) and increasing the rotational speed (R) of the compressor (42). This increases the capacity exerted by the heat source unit (40), thereby promoting the cooling of the storage chamber (50a) by the cooling operation of the cooling unit (50), and preventing the internal temperature (Tsv) from becoming too high.

[0233] Furthermore, in the refrigeration system (10) of the embodiment, the control unit (32) outputs control information based on cooling status information obtained from each of the plurality of cooling units (50).

[0234] In the above configuration, control information can be output that takes into account the cooling status of the storage compartment (50a) in each of the multiple cooling units (50) (particularly the change in internal temperature (Tsv) over time). Since the operation of the heat source unit (40) can be controlled based on such control information, the operation of the heat source unit (40) can be appropriately controlled according to the cooling status of the storage compartment (50a) in each of the multiple cooling units (50).

[0235] Furthermore, in the refrigeration system (10) of the embodiment, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that when the cooling load in the cooling unit (50) is in a low load state, the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase corresponding to the difference between the low pressure (LP) and the target low pressure (LPT), and when the cooling load is in a high load state, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase that is higher than the first rate of increase.

[0236] In the above configuration, when the cooling load on the cooling unit (50) is high, the rate at which the rotational speed (R) of the compressor (42) increases can be increased. This shortens the operating time of the compressor (42), thereby reducing the power consumption of the compressor (42).

[0237] Furthermore, in the refrigeration system (10) of the embodiment, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT) corresponding to the target low pressure (LPT). The predetermined amount (ΔR) when the cooling load is in a low load state is a first amount (ΔR1) corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT). The predetermined amount (ΔR) when the cooling load is in a high load state is a second amount (ΔR2) which is greater than the first amount (ΔR1).

[0238] In the above configuration, when the cooling load in the cooling unit (50) is in a high-load state, the predetermined amount (ΔR), which is the amount by which the rotational speed (R) of the compressor (42) increases per cycle, can be increased, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0239] Furthermore, in the refrigeration system (10) of the embodiment, the low-load state is a state in which the stop duration, which is the time from when the compressor (42) stops until when the compressor (42) starts, is greater than or equal to a predetermined time, and the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed. The high-load state is a state in which the stop duration is shorter than the predetermined time, or a state in which the rotational speed (R) of the compressor (42) is higher than the predetermined rotational speed.

[0240] In the above configuration, if the stopping time is shorter than a predetermined time, or if the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, processing can be performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state (processing to increase the rate of increase of the rotational speed (R) of the compressor (42)). In this way, based on the result of comparing the stopping time with the predetermined time and the result of comparing the rotational speed (R) of the compressor (42) with the predetermined rotational speed, processing can be appropriately performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state.

[0241] Furthermore, in the refrigeration system (10) of the embodiment, the storage compartment (50a) is an open-type storage compartment (50a).

[0242] In the above configuration, the cooling load in the open-type storage container (50a) tends to be higher than the cooling load in the closed-type storage container (50a). Thus, in situations where the cooling load in the cooling unit (50) tends to be high, it is possible to appropriately perform processing to increase the rate at which the rotational speed (R) of the compressor (42) increases, thereby appropriately reducing the power consumption of the compressor (42).

[0243] (Modification 1 of the Embodiment) The refrigeration system (10) of Modification 1 of the Embodiment differs from the refrigeration system (10) in the compressor control in the heat source unit (40). The other configurations and operations of the refrigeration system (10) of Modification 1 of the Embodiment are the same as those of the refrigeration system (10) of the Embodiment.

[0244] In the compressor control of the modified embodiment 1, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward the target rotational speed (RT). The predetermined amount (ΔR) is a quantity corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT). Specifically, the larger the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), the larger the predetermined amount (ΔR).

[0245] In each of the first and second operations of compressor control in the modified embodiment 1, the heat source control unit (46) repeatedly performs the operation of "determining a predetermined amount (ΔR) based on the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), and controlling the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by the determined predetermined amount (ΔR)" until the rotational speed (R) of the compressor (42) reaches the target rotational speed (RT).

[0246] As shown in Figure 14, the target rotational speed (RT) in the first operation of the modified embodiment 1 (when the connected load is in a low load state) is the first target rotational speed (RT1) corresponding to the target low pressure (LPT). Specifically, the lower the target low pressure (LPT), the higher the first target rotational speed (RT1).

[0247] As shown in Figure 15, in the second operation of the modified embodiment 1 (when the connected load is in a high load state), the target rotational speed (RT) is a second target rotational speed (RT2) that is higher than the first target rotational speed (RT1). For example, the second target rotational speed (RT2) is greater than or equal to the first target rotational speed (RT1), which changes according to the target low pressure (LPT).

[0248] In the second operation described above, the target rotational speed (RT) can be set higher than in the first operation. This allows for a larger predetermined amount (ΔR), which is the amount of increase in the rotational speed (R) of the compressor (42) per cycle, thus increasing the rate at which the rotational speed (R) of the compressor (42) increases. As a result, the operating time of the compressor (42) in the second operation (the length of time from start to stop in the waveform shown by the solid line in Figure 15) can be shortened compared to the operating time of the compressor (42) in the first operation (the length of time from start to stop in the waveform shown by the dashed line in Figure 15).

[0249] [Effects of Modified Example 1 of the Embodiment] In the refrigeration system (10) of Modified Example 1 of the Embodiment, the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward the target rotational speed (RT). The predetermined amount (ΔR) is an amount corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT). When the cooling load in the cooling unit (50) is in a low load state, the target rotational speed (RT) is the first target rotational speed (RT1) corresponding to the target low pressure (LPT). When the cooling load in the cooling unit (50) is in a high load state, the target rotational speed (RT) is the second target rotational speed (RT2) which is higher than the first target rotational speed (RT1).

[0250] In the above configuration, the target rotational speed (RT) can be increased when the cooling load in the cooling unit (50) is in a high-load state. This allows for a larger predetermined amount (ΔR), which is the amount of increase in the rotational speed (R) of the compressor (42) per cycle, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0251] (Modification of Embodiment 2) The refrigeration system (10) of Modification of Embodiment 2 differs from the refrigeration system (10) of Embodiment in its definition of "low load state" and "high load state". The other configurations and processes of the refrigeration system (10) of Modification of Embodiment 2 are the same as those of the refrigeration system (10) of Embodiment.

[0252] In the refrigeration system (10) of the modified embodiment 2, the low-load state is a state in which the stop duration, which is the time from when the compressor (42) stops until when it starts up, is longer than a predetermined time. The high-load state is a state in which the stop duration is shorter than a predetermined time.

[0253] In the cooling load determination process of the modified embodiment 2, the process of step (S62) shown in Figure 11 is omitted. Specifically, if the stop duration in step (S61) is longer than a predetermined time, the control unit (32) determines that the connection load is in a "low load state" (step (S63)). If the stop duration in step (S61) is shorter than a predetermined time, the control unit (32) determines that the connection load is in a "high load state" (step (S64)).

[0254] [Effects of Modified Example 2 of the Embodiment] In the refrigeration system (10) of Modified Example 2 of the Embodiment, the low-load state is a state in which the stop duration, which is the time from when the compressor (42) stops until when it starts up, is longer than a predetermined time. The high-load state is a state in which the stop duration is shorter than a predetermined time.

[0255] In the above configuration, if the stop duration is shorter than a predetermined time, processing can be performed in accordance with the case where the cooling load in the cooling unit (50) is in a high load state (processing to increase the rate of increase of the rotational speed (R) of the compressor (42)). In this way, based on the result of comparing the stop duration with the predetermined time, processing can be appropriately performed in accordance with the case where the cooling load in the cooling unit (50) is in a high load state.

[0256] (Other Embodiments) In the above description, the following configurations or processes may be used.

[0257] The cooling status information does not necessarily have to include operational status information (information regarding the status of the cooling operation in the cooling unit (50)). For example, the cooling status information may include the start temperature (Ts1) and the stop temperature (Ts2) instead of the operational status information. In this case, it is possible to determine the status of the cooling operation in the cooling unit (50) (whether or not the cooling operation has stopped) based on the start temperature (Ts1), the stop temperature (Ts2), and the internal temperature (Tsv).

[0258] Furthermore, if the relationship between the start temperature (Ts1) and stop temperature (Ts2) of the cooling unit (50) and the set temperature (Tset) is known in the control system (30), the start temperature (Ts1) and stop temperature (Ts2) do not need to be included in the cooling status information. In this case, the start temperature (Ts1) and stop temperature (Ts2) can be derived based on the set temperature (Tset) included in the cooling status information and the relationship between the start temperature (Ts1) and stop temperature (Ts2) and the set temperature (Tset).

[0259] The control patterns pre-prepared in the control system (30) are not limited to the first to sixth control patterns. For example, the control patterns pre-prepared in the control system (30) may be a part of the first to sixth control patterns, or they may be a set of at least one of the first to sixth control patterns and other control patterns. The same applies to the types (types corresponding to cooling conditions) pre-prepared in the control system (30).

[0260] The control unit (32) may consist of a single processor and memory, or it may consist of multiple processors and memories. The multiple processors and memories may be provided together in one device (enclosure), or they may be provided in different devices (enclosures). Similarly, the storage unit (31) may consist of a single storage device, or it may consist of multiple storage devices. The same applies to the heat source control unit (46) and the utilization control unit (56).

[0261] For example, the control unit (32) may be provided in the heat source unit (40). Specifically, the control unit (32) may be part of a heat source control unit (46) provided in the heat source unit (40).

[0262] Furthermore, while embodiments and modifications have been described, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Additionally, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Moreover, the designations "first," "second," "third," etc., in the specification and claims are used to distinguish the phrases to which these designations are given, and do not limit the number or order of such phrases.

[0263] (Other examples) The embodiments of this disclosure may also be as follows:

[0264] A first aspect of the present disclosure relates to a heat source unit that constitutes a refrigeration cycle by circulating a refrigerant, together with a cooling unit (50) that performs or stops a cooling operation to cool the air inside the storage container (50a) according to the internal temperature (Tsv), which is the temperature of the air inside the storage container (50a), and a set temperature (Tset), wherein the heat source unit comprises a compressor (42) that sucks in and compresses the refrigerant, and a heat radiator (43) that dissipates heat from the refrigerant discharged from the compressor (42), The system includes a heat source control unit (46) which starts the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant at the suction side of the compressor (42), exceeds a first low pressure (LP1), controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT), and stops the compressor (42) when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase corresponding to the difference between the low pressure (LP) and the target low pressure (LPT) when the cooling load in the cooling unit (50) is in a low load state. When the cooling load is in a high-load state, the rotational speed (R) of the compressor (42) is controlled so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase that is higher than the first rate of increase.

[0265] In the first embodiment, when the cooling load in the cooling unit (50) is in a high-load state, the rate at which the rotational speed (R) of the compressor (42) increases can be increased. This shortens the operating time of the compressor (42), and thus reduces the power consumption of the compressor (42).

[0266] A second aspect of the present disclosure is a heat source unit of the first aspect, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT) corresponding to the target low pressure (LPT), and the predetermined amount (ΔR) when the cooling load is in a low load state is a first amount (ΔR1) corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), and the predetermined amount (ΔR) when the cooling load is in a high load state is a second amount (ΔR2) which is greater than the first amount (ΔR1).

[0267] In the second embodiment, when the cooling load in the cooling unit (50) is in a high load state, a predetermined amount (ΔR), which is the amount by which the rotational speed (R) of the compressor (42) increases per cycle, can be increased, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0268] A third aspect of the present disclosure is a heat source unit according to the first aspect, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT), the predetermined amount (ΔR) is an amount corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), the target rotational speed (RT) when the cooling load is in a low load state is a first target rotational speed (RT1) corresponding to the target low pressure (LPT), and the target rotational speed (RT) when the cooling load is in a high load state is a second target rotational speed (RT2) which is higher than the first target rotational speed (RT1).

[0269] In the third embodiment, the target rotational speed (RT) can be increased when the cooling load in the cooling unit (50) is in a high-load state. This allows for a certain amount (ΔR), which is the amount of increase in the rotational speed (R) of the compressor (42) per cycle, and as a result, the rate at which the rotational speed (R) of the compressor (42) increases can be increased.

[0270] A fourth aspect of the present disclosure is a heat source unit in any one of the first to third aspects, wherein the low-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is greater than or equal to a predetermined time, and the high-load state is a state in which the stop duration is shorter than the predetermined time.

[0271] In the fourth embodiment, if the duration of the stoppage is shorter than a predetermined time, processing can be performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state (processing to increase the rate of increase of the rotational speed (R) of the compressor (42)). In this way, processing can be appropriately performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state based on the result of comparing the duration of the stoppage with the predetermined time.

[0272] A fifth aspect of the present disclosure is a heat source unit in any one of the first to third aspects, wherein the low-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is greater than or equal to a predetermined time, and the rotational speed (R) of the compressor (42) is less than or equal to a predetermined rotational speed, and the high-load state is a state in which the stop duration is shorter than the predetermined time, or the rotational speed (R) of the compressor (42) is higher than the predetermined rotational speed.

[0273] In the fifth embodiment, if the duration of the stop is shorter than a predetermined time, or if the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, processing can be performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state (processing to increase the rate of increase of the rotational speed (R) of the compressor (42)). In this way, based on the result of comparing the duration of the stop with the predetermined time and the result of comparing the rotational speed (R) of the compressor (42) with the predetermined rotational speed, processing can be appropriately performed in accordance with the case where the cooling load in the cooling unit (50) is in a high-load state.

[0274] A sixth aspect of the present disclosure is a heat source unit in any one of the first to fifth aspects, wherein the storage compartment (50a) is an open-type storage compartment (50a).

[0275] In the sixth embodiment, the cooling load in the open-type storage container (50a) tends to be higher than the cooling load in the closed-type storage container (50a). In this way, under conditions where the cooling load in the cooling unit (50) tends to be high, it is possible to appropriately perform processing to increase the rate at which the rotational speed (R) of the compressor (42) increases, thereby appropriately reducing the power consumption of the compressor (42).

[0276] A seventh aspect of the present disclosure is a refrigeration system comprising a heat source unit according to any one of the first to sixth aspects and the cooling unit (50).

[0277] An eighth aspect of the present disclosure relates to a control method for a heat source unit (40) comprising a storage compartment (50a), an evaporator (52) for cooling the air inside the storage compartment (50a), a cooling unit (50) that performs or stops a cooling operation to cool the air inside the storage compartment (50a) according to the internal temperature (Tsv), which is the temperature of the air inside the storage compartment (50a), and a set temperature (Tset), a refrigerant circuit (25) that performs a refrigeration cycle by circulating a refrigerant, a compressor (42) that inhales and compresses the refrigerant, and a heat radiator (43) that dissipates heat from the refrigerant discharged from the compressor (42), wherein the control method for the heat source unit comprises a start step of starting the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), The system includes a control step of controlling the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT), and a stop step of stopping the compressor (42) when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), wherein the control step controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase corresponding to the difference between the low pressure (LP) and the target low pressure (LPT) when the cooling load in the cooling unit (50) is in a low load state, and controls the rotational speed (R) of the compressor (42) so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase which is higher than the first rate of increase when the cooling load is in a high load state.

[0278] In the eighth aspect, when the cooling load in the cooling unit (50) is in a high-load state, the rate at which the rotational speed (R) of the compressor (42) increases can be increased. This shortens the operating time of the compressor (42), and thus reduces the power consumption of the compressor (42).

[0279] As described above, this disclosure is useful as a control method for control systems, refrigeration systems, and refrigeration equipment.

[0280] 10 Refrigeration system 20 Refrigeration device 25 Refrigerant circuit 30 Control system 31 Memory unit 32 Control unit 40 Heat source unit 41 Heat source circuit 42 Compressor 43 Heat source heat exchanger (radiator) 45 Heat source fan 46 Heat source control unit 50 Cooling unit 50a Storage compartment 51 Utilization circuit 52 Utilization heat exchanger (evaporator) 53 Utilization expansion valve 55 Utilization fan 56 Utilization control unit 60 Heat source sensor 70 Utilization sensor

Claims

1. A control system applied to a refrigeration device (20) that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (25) composed of the heat source unit (40) and the cooling unit (50), the control system comprising: a heat source unit (40) having a compressor (42) and a heat sink (43); a cooling unit (50) having a storage compartment (50a) and an evaporator (52) for cooling the air inside the storage compartment (50a), and which performs or stops a cooling operation to cool the air inside the storage compartment (50a) according to the internal temperature (Tsv), which is the temperature of the air inside the storage compartment (50a), and a set temperature (Tset); the control system comprising a control unit (32) that controls the refrigeration device (20), wherein the control unit (32) outputs control information for controlling the operation of the heat source unit (40) based on cooling status information, which is information regarding the cooling status of the storage compartment (50a) in the cooling unit (50a) and includes the change in the internal temperature (Tsv) over time.

2. The control system according to claim 1, wherein the cooling status information includes a plurality of temperature values ​​that can derive the change in the internal temperature (Tsv) over time, and the set temperature (Tset).

3. The control system of claim 2, wherein the cooling status information includes the plurality of temperature values, the set temperature (Tset), and information regarding the status of the cooling operation in the cooling unit (50).

4. A control system according to any one of claims 1 to 3, wherein in the heat source unit (40), when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), the compressor (42) is started, the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP) and the target low pressure (LPT), the compressor (42) is stopped when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), and the control information includes at least one of first information for controlling the target low pressure (LPT), second information for controlling the second low pressure (LP2), and third information for controlling the rate of increase of the rotational speed (R) of the compressor (42).

5. The control system of claim 4, wherein the cooling unit (50) starts the cooling operation when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and stops the cooling operation when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is the temperature corresponding to the set temperature (Tset) and lower than the start temperature (Ts1), and the control information includes at least one of the first information, the second information, the third information, and the fourth information for controlling the start temperature (Ts1).

6. A control system in any one of claims 1 to 5, wherein the control unit (32) selects a type corresponding to the cooling status information from among a plurality of types, each corresponding to a different cooling status of the storage container (50a), and outputs the control information based on the selected type.

7. A control system according to claim 6, wherein the control unit (32) outputs the control information based on the selected type and a control execution condition which includes a cooling condition that the type corresponds to a predetermined type, and is necessary for outputting the control information.

8. In any one of claims 1 to 3, the heat source unit (40) controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP), which is the refrigerant pressure on the suction side of the compressor (42), and the target low pressure (LPT); the cooling unit (50) starts the cooling operation when the internal temperature (Tsv) exceeds the start temperature (Ts1) corresponding to the set temperature (Tset); stops the cooling operation when the internal temperature (Tsv) falls below the stop temperature (Ts2), which is the temperature corresponding to the set temperature (Tset) and lower than the start temperature (Ts1); and the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a first cooling status and the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed. The first cooling state includes a state in which the cooling operation is stopped, or a state in which the internal temperature (Tsv) is stable within a range near the stop temperature (Ts2) as the lower limit, and the control information includes information for increasing the target low pressure (LPT).

9. A control system according to any one of claims 1 to 3, wherein the heat source unit (40) controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), and the target low pressure (LPT); the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a second cooling status and a predetermined time has elapsed, which is a predetermined time before the closing time of the store where the cooling unit (50) is installed; the second cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) has not risen sharply; and the control information includes information for raising the target low pressure (LPT).

10. In any one of claims 1 to 3, the heat source unit (40) starts the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), and stops the compressor (42) when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1); the cooling unit (50) starts the cooling operation when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and stops the cooling operation when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is a temperature corresponding to the set temperature (Tset) and is lower than the start temperature (Ts1); The control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a third cooling status and the operating mode of the refrigeration device (20) is an operating mode that prioritizes reducing energy consumption, wherein the third cooling status includes a situation in which the internal temperature (Tsv) is within a predetermined range including the set temperature (Tset) and the internal temperature (Tsv) is not rising rapidly, and the control information includes information for raising the start temperature (Ts1).

11. In any one of claims 1 to 3, the heat source unit (40) starts the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), and stops the compressor (42) when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1); the cooling unit (50) starts the cooling operation when the internal temperature (Tsv) exceeds a start temperature (Ts1) corresponding to the set temperature (Tset), and stops the cooling operation when the internal temperature (Tsv) falls below a stop temperature (Ts2) which is a temperature corresponding to the set temperature (Tset) and is lower than the start temperature (Ts1); The control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a fourth cooling status and the rotational speed (R) of the compressor (42) is below a predetermined rotational speed, wherein the fourth cooling status includes a situation in which the cooling operation has stopped, or a situation in which the internal temperature (Tsv) is decreasing within a range near the lower limit of the stop temperature (Ts2), and the control information includes information for increasing the second low pressure (LP2).

12. In any one of claims 1 to 3, the heat source unit (40) starts the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1), the rotational speed (R) of the compressor (42) is controlled according to the difference between the low pressure (LP) and the target low pressure (LPT), the compressor (42) stops when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1), and the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a fifth cooling status and the cooling load in the cooling unit (50) is in a high load state. The high-load state is a state in which the stop duration, which is the time from the stop of the compressor (42) to the start of the compressor (42), is shorter than a predetermined time, or the rotational speed (R) of the compressor (42) is higher than a predetermined rotational speed, the fifth cooling state includes a state in which the internal temperature (Tsv) is rising rapidly, and the control information is a control system that includes information for increasing the rate of increase of the rotational speed (R) of the compressor (42).

13. In the control system of claim 12, the heat source unit (40) has a heat source control unit (46) that starts the compressor (42) when the low pressure (LP) exceeds the first low pressure (LP1), controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT), and stops the compressor (42) when the low pressure (LP) falls below the second low pressure (LP2), and the heat source control unit (46) controls the rotational speed (R) of the compressor (42) such that the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase according to the difference between the low pressure (LP) and the target low pressure (LPT) when the control information output from the control unit (32) does not include information for increasing the rate of increase of the rotational speed (R) of the compressor (42), A control system that controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) becomes a second rotational speed that is higher than the first rotational speed, when the control information output from the control unit (32) includes information for increasing the rate at which the rotational speed (R) of the compressor (42) increases.

14. The control system of claim 13, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT) corresponding to the target low pressure (LPT), wherein the predetermined amount (ΔR) when the cooling load is in a low load state is a first amount (ΔR1) corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), and the predetermined amount (ΔR) when the cooling load is in a high load state is a second amount (ΔR2) which is greater than the first amount (ΔR1).

15. The control system of claim 13, wherein the heat source control unit (46) controls the rotational speed (R) of the compressor (42) so that the rotational speed (R) of the compressor (42) increases by a predetermined amount (ΔR) toward a target rotational speed (RT), the predetermined amount (ΔR) is an amount corresponding to the difference between the rotational speed (R) of the compressor (42) and the target rotational speed (RT), the target rotational speed (RT) when the cooling load is in a low load state is a first target rotational speed (RT1) corresponding to the target low pressure (LPT), and the target rotational speed (RT) when the cooling load is in a high load state is a second target rotational speed (RT2) which is higher than the first target rotational speed (RT1).

16. A control system according to any one of claims 13 to 15, wherein the storage compartment (50a) is an open-type storage compartment (50a).

17. A control system according to any one of claims 1 to 3, wherein the heat source unit (40) controls the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), and the target low pressure (LPT); the control unit (32) outputs the control information when the cooling status derived based on the cooling status information corresponds to a sixth cooling status; the sixth cooling status includes a situation in which the internal temperature (Tsv) is higher than a predetermined range including the set temperature (Tset); and the control information includes information for reducing the target low pressure (LPT).

18. A control system according to any one of claims 1 to 17, wherein the refrigeration device (20) comprises the heat source unit (40) and a plurality of the cooling units (50), and the control unit (32) outputs the control information based on the cooling status information obtained from each of the plurality of cooling units (50).

19. A refrigeration system comprising a control system according to any one of claims 1 to 18 and the refrigeration device (20).

20. A control method for a refrigeration apparatus (20) that performs a refrigeration cycle by circulating a refrigerant in a refrigerant circuit (25) composed of the heat source unit (40) and the cooling unit (50), the method comprising: an acquisition step of acquiring cooling status information, which is information relating to the cooling status of the storage container (50a) in the cooling unit (50a) and includes the change in the internal temperature (Tsv) over time; and a control step of controlling the operation of the heat source unit (40) based on the cooling status information acquired in the acquisition step.

21. A control method for a heat source unit comprising a storage compartment (50a) and an evaporator (52) for cooling the air inside the storage compartment (50a), and a cooling unit (50) that performs a cooling operation to cool the air inside the storage compartment (50a) according to the internal temperature (Tsv), which is the temperature of the air inside the storage compartment (50a), and a set temperature (Tset), and a refrigerant circuit (25) that performs a refrigeration cycle by circulating a refrigerant, comprising a compressor (42) that draws in and compresses the refrigerant, and a heat radiator (43) that dissipates heat from the refrigerant discharged from the compressor (42), comprising: a start step of starting the compressor (42) when the low pressure (LP), which is the pressure of the refrigerant on the suction side of the compressor (42), exceeds a first low pressure (LP1); and a control step of controlling the rotational speed (R) of the compressor (42) according to the difference between the low pressure (LP) and the target low pressure (LPT), A control method for a heat source unit, comprising: a stop step of stopping the compressor (42) when the low pressure (LP) falls below a second low pressure (LP2) which is lower than the first low pressure (LP1); the control step of controlling the rotational speed (R) of the compressor (42) so that when the cooling load in the cooling unit (50) is in a low load state, the rate of increase of the rotational speed (R) of the compressor (42) becomes a first rate of increase corresponding to the difference between the low pressure (LP) and the target low pressure (LPT); and when the cooling load is in a high load state, the rotational speed (R) of the compressor (42) is controlled so that the rate of increase of the rotational speed (R) of the compressor (42) becomes a second rate of increase which is higher than the first rate of increase.

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