Driving state determination device, driving state determination system, and driving state determination method

Abstract

To provide an operating state determination device capable of appropriately determining an operating state of a refrigeration circuit by using an easy configuration regardless of specifications of the refrigeration circuit such as a compressor.SOLUTION: An operating state determination device includes: an estimation section that estimates a relation between estimation physical quantity of a refrigerant within at least one of first piping connecting a compressor and a condenser and third piping connecting a restriction part and an evaporator and an outside air temperature, on the basis of a temperature and pressure of the refrigerant within each of second piping connecting the condenser and the restriction part and fourth piping connecting the evaporator and the compressor and a measurement result of the outside air temperature; and a determination section that determines an operating state of a refrigeration circuit of a determination target, on the basis of threshold information on determination reference information associated with first refrigeration condition information indicating a set cooling temperature of the refrigeration circuit of the determination target and a type of the refrigerant, out of a plurality of pieces of determination reference information in which the first refrigeration condition information and the threshold information indicating the relation between a threshold value of the estimation physical quantity and the outside air temperature are associated with each other and the relation between the estimation physical quantity and the outside air temperature.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a driving state determination device, a driving state determination system, and a driving state determination method. [Background technology]

[0002] Conventionally, there is known a configuration for diagnosing an abnormality in a refrigeration circuit including a compressor, a condenser, an expansion valve, and an evaporator (see, for example, Patent Document 1). In the configuration of Patent Document 1, temperatures are measured at four locations: the inlet of the compressor, the outlet of the compressor, the outlet of the condenser, and the inlet of the evaporator. Next, the flow rate of the refrigerant is calculated using characteristic parameters determined based on the specifications of the compressor and the temperature measurement results. Then, the heat flow in each component of the refrigeration circuit is calculated based on the refrigerant flow rate, and the presence or absence of an abnormality in the refrigeration circuit is diagnosed based on the calculated heat quantity. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-143817 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the configuration of Patent Document 1, for example, when the compressor is changed to another compressor having different characteristic parameters, the characteristic parameters used for diagnosis must also be changed. Therefore, it is necessary to prepare characteristic parameters corresponding to the types of compressors that can be used. In addition, for a new compressor that is to be used, it is necessary to redefine the characteristic parameters.

[0005] The present disclosure aims to provide an operating state determination device, an operating state determination system, and an operating state determination method that can appropriately determine the operating state of a refrigeration circuit with a simple configuration regardless of the specifications of the refrigeration circuit such as a compressor. [Means for solving the problem]

[0006] The operating state determination device disclosed herein is an operating state determination device that determines the operating state of a refrigeration circuit that includes a compressor, a condenser, a throttling section, an evaporator, a first pipe connecting the compressor and the condenser, a second pipe connecting the condenser and the throttling section, a third pipe connecting the throttling section and the evaporator, and a fourth pipe connecting the evaporator and the compressor, and determines a physical quantity of the refrigerant in at least one of the first pipe and the third pipe based on measurement results of the temperature and pressure of the refrigerant in the second pipe, measurement results of the temperature and pressure of the refrigerant in the fourth pipe, and measurement results of the outside air temperature. The system includes an estimation unit that estimates the relationship between an estimated physical quantity and an outside air temperature, and a judgment unit that selects, from a plurality of judgment criteria information in which first refrigeration condition information representing the set cooling temperature and type of refrigerant of the refrigeration circuit and threshold information representing the relationship between a threshold of the estimated physical quantity and the outside air temperature are associated, the judgment criteria information associated with the first refrigeration condition information representing the set cooling temperature and type of refrigerant of the refrigeration circuit to be judged, and judges the operating state of the refrigeration circuit to be judged based on the threshold information associated with the selected judgment criteria information and the relationship between the estimated physical quantity and the outside air temperature.

[0007] The operating state determination system of the present disclosure comprises a measurement unit, a database, and the above-mentioned operating state determination device connected to the measurement unit and the database via a network, wherein the measurement unit measures the temperature and pressure of the refrigerant in the second pipe, the temperature and pressure of the refrigerant in the fourth pipe, and the outside air temperature at the time of measuring the temperature and the pressure, and outputs measurement information representing the measurement results to the operating state determination device via the network, the database stores the multiple pieces of judgment criterion information, an estimation unit of the operating state determination device estimates the relationship between the estimated physical quantity and the outside air temperature based on the measurement information output from the measurement unit, and the judgment unit selects the judgment criterion information from the multiple pieces of judgment criterion information stored in the database.

[0008] The operating state determination method of the present disclosure is an operating state determination method performed by an operating state determination device that determines the operating state of a refrigeration circuit including a compressor, a condenser, a throttling section, an evaporator, a first pipe connecting the compressor and the condenser, a second pipe connecting the condenser and the throttling section, a third pipe connecting the throttling section and the evaporator, and a fourth pipe connecting the evaporator and the compressor, wherein the operating state determination device determines the operating state of at least one of the first pipe and the third pipe based on the measurement results of the temperature and pressure of the refrigerant in the second pipe, the measurement results of the temperature and pressure of the refrigerant in the fourth pipe, and the measurement result of the outside air temperature. The system estimates the relationship between an estimated physical quantity, which is the physical quantity of the refrigerant in at least one of the pipes, and the outside air temperature, and selects, from a plurality of judgment criteria information in which first refrigeration condition information representing the set cooling temperature and type of refrigerant of the refrigeration circuit to be judged is associated with first refrigeration condition information representing the set cooling temperature and type of refrigerant of the refrigeration circuit to be judged, and judges the operating state of the refrigeration circuit to be judged based on the threshold information associated with the selected judgment criteria information and the relationship between the estimated physical quantity and the outside air temperature. Effect of the Invention

[0009] According to the operating state determination device, operating state determination system, and operating state determination method disclosed herein, the operating state of the refrigeration circuit can be appropriately determined with a simple configuration regardless of the specifications of the refrigeration circuit such as the compressor. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a refrigeration system according to first to fourth embodiments. [Diagram 2] FIG. 1 is a diagram for explaining the configuration of the determination criteria information according to the first to third embodiments using a scatter diagram; [Diagram 3] Mollier diagram of the refrigeration circuit according to the first, third and fourth embodiments [Figure 4] 1 is a flowchart showing a main routine of a driving state determination process according to the first and fourth embodiments; [Diagram 5]1 is a flowchart of a subroutine of a driving state determination process according to the first, second, and fourth embodiments; [Figure 6] 1 is a flowchart of a subroutine of a driving state determination process according to the first and fourth embodiments. [Figure 7] Mollier diagram of the refrigeration circuit according to the second embodiment [Figure 8] 11 is a flowchart of a main routine of a driving state determination process according to a second embodiment. [Figure 9] 11 is a flowchart of a subroutine of the driving state determination process according to the second embodiment. [Figure 10] 11 is a flowchart of a main routine of a driving state determination process according to a third embodiment. [Figure 11A] FIG. 13 is a diagram for explaining the configuration of the judgment criteria information of the first model of reference refrigeration apparatus according to the fourth embodiment using a scatter diagram. [Figure 11B] FIG. 13 is a diagram for explaining the configuration of the judgment criteria information of the second model of reference refrigeration apparatus according to the fourth embodiment using a scatter diagram. [Figure 12] 13 is a flowchart of a subroutine of the driving state determination process according to the fourth embodiment. [Figure 13] FIG. 1 is a block diagram showing a schematic configuration of a refrigeration system according to a first modified example. [Figure 14] FIG. 11 is a block diagram showing a schematic configuration of a refrigeration system according to a second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Embodiment] An embodiment of the present disclosure will be described.

[0012] First Embodiment First, a first embodiment of the present disclosure will be described.

[0013] (Refrigeration system configuration) First, the configuration of the refrigeration system will be described. Fig. 1 is a block diagram showing a schematic configuration of the refrigeration system. Fig. 2 is a diagram explaining the configuration of the judgment criteria information using a scatter diagram. Fig. 3 is a Mollier diagram of the refrigeration circuit.

[0014] The refrigeration system 1 shown in FIG.

[0015] The refrigeration device 2 is disposed, for example, in a store (not shown) and cools products in the store. The refrigeration device 2 includes a refrigeration circuit 20 including a compressor 21, a condenser 22, a throttle unit 23, and an evaporator 24.

[0016] The compressor 21 is, for example, a rotary compressor. One end of a pipe 201 is connected to the compressor 21. The compressor 21 compresses the refrigerant and sends it to the pipe 201. The other end of the pipe 201 and one end of the pipe 202 are connected to the condenser 22. The condenser 22 cools the refrigerant compressed by the compressor 21 and sends it to the pipe 202. The throttling unit 23 is, for example, an electric expansion valve. The other end of the pipe 202 and one end of the pipe 203 are connected to the throttling unit 23. The throttling unit 23 throttles the refrigerant cooled by the condenser 22 and sends it to the pipe 203. The other end of the pipe 203 and one end of the pipe 204 are connected to the evaporator 24. The evaporator 24 exchanges heat between the refrigerant throttled by the throttle unit 23 and air, and sends the refrigerant after heat exchange to the pipe 204. The air cooled by heat exchange in the evaporator 24 cools an object to be cooled, such as a commodity. The other end of the pipe 204 is connected to the compressor 21, and the refrigerant sent from the evaporator 24 is returned to the compressor 21. The pipes 201, 202, 203, and 204 are examples of a first pipe, a second pipe, a third pipe, and a fourth pipe, respectively, of the present disclosure.

[0017] Examples of the refrigerant for the refrigeration circuit 20 include carbon dioxide, hydrocarbon, ammonia, air, and water. Examples of the set cooling temperature for the refrigeration circuit 20 include a refrigeration temperature (-5°C or higher and +10°C or lower) and a freezing temperature (-30°C or higher and -20°C or lower). Note that the refrigeration temperature or the freezing temperature is not limited to the above-mentioned temperatures. Also, three or more set cooling temperatures may be set.

[0018] The operating state determination system 3 performs a process of determining whether or not the amount of refrigerant in the refrigeration circuit 20 is abnormal and a process of determining the amount of refrigerant adjusted as a process of determining the operating state of the refrigeration circuit 20. If the amount of refrigerant in the refrigeration circuit 20 exceeds an upper limit amount, it is determined that the amount of refrigerant is abnormal. The refrigerant adjustment amount is the amount of refrigerant removed from the refrigeration circuit 20 to return the amount of refrigerant in the refrigeration circuit 20 to a predetermined amount that is equal to or less than the upper limit amount. In other words, the refrigerant adjustment amount is the amount of refrigerant required to return the amount of refrigerant in the refrigeration circuit 20 to a normal amount. The operating state determination system 3 includes a measurement unit 4 and an operating state determination device 5.

[0019] The measurement unit 4 measures the temperature and pressure at a predetermined measurement position of the refrigeration circuit. The measurement unit 4 measures the air temperature (outside air temperature) around the refrigeration device 2 when measuring the temperature and pressure. The measurement unit 4 includes a first position measurement unit 41, a second position measurement unit 42, and a third position measurement unit 43.

[0020] The first position measurement unit 41 and the second position measurement unit 42 each include a temperature sensor and a pressure sensor. The first position measurement unit 41 measures the temperature (refrigerator inlet temperature) and pressure (refrigerator inlet pressure) of the refrigerant at the refrigerator inlet P1, and transmits measurement information representing the measurement results to the operating state determination device 5. The refrigerator inlet P1 is a predetermined measurement position in the pipe 204 connecting the compressor 21 and the evaporator 24. The second position measurement unit 42 measures the temperature (condenser outlet temperature) and pressure (condenser outlet pressure) of the refrigerant at the condenser outlet P2, and transmits measurement information representing the measurement results to the operating state determination device 5. The condenser outlet P2 is a predetermined measurement position in the pipe 202 connecting the condenser 22 and the throttle unit 23.

[0021] The third position measurement unit 43 includes a temperature sensor. The third position measurement unit 43 measures the outside air temperature and transmits measurement information indicating the measurement result to the operating state determination device 5. For example, when the compressor 21 is installed outdoors, the third position measurement unit 43 measures the outdoor temperature near the compressor 21 as the outside air temperature.

[0022] The operating state determination device 5 is arranged, for example, in the same store (not shown) as the refrigeration device 2. The operating state determination device 5 includes an operation unit 51, a notification unit 52, a storage unit 53, a database 54, and a control unit 55.

[0023] The operation unit 51 is configured to be able to transmit and receive various signals to and from the control unit 55. The operation unit 51 is operated by a user of the operating state determination device 5. The operation unit 51 outputs a signal corresponding to the operation to the control unit 55. For example, when the operation unit 51 receives an operation to start a process of determining the operating state of the refrigeration circuit 20, it outputs a signal to that effect to the control unit 55.

[0024] The notification unit 52 notifies the user of information related to the refrigeration apparatus 2 under the control of the control unit 55. The notification unit 52 includes at least one of a display unit, a light emitting unit, and a sound output unit.

[0025] The storage unit 53 is composed of a memory, a hard disk, or the like. The storage unit 53 stores various information necessary for controlling the operating state determination device 5. The storage unit 53 stores physical quantity information used in the determination process of the operating state of the refrigeration circuit 20. The physical quantity information is generated by the control unit 55 based on the measurement result in the measurement unit 4. The physical quantity information includes information representing the compressor outlet specific enthalpy value estimated by the control unit 55, the measurement date and time in the measurement unit 4, and the outside air temperature measured by the measurement unit 4. The compressor outlet specific enthalpy value is an example of an estimated physical quantity, and is the specific enthalpy value of the refrigerant at the compressor outlet P3. The compressor outlet P3 is a predetermined unmeasured position in the piping 201 connecting the compressor 21 and the condenser 22. The physical quantity information is deleted from the storage unit 53 after being used in the determination process of the operating state and the update process of the determination criterion information.

[0026] Database 54 stores a plurality of pieces of judgment information related to reference refrigeration devices (hereinafter sometimes referred to as "reference refrigeration devices") having different set cooling temperatures and / or refrigerants. Examples of reference refrigeration devices having different set cooling temperatures and / or refrigerants include a first reference refrigeration device whose refrigerant is carbon dioxide and whose set cooling temperature is a refrigeration temperature, and a second reference refrigeration device whose refrigerant is a hydrocarbon and whose set cooling temperature is a refrigeration temperature. Each piece of judgment information comprises a plurality of pieces of judgment reference information and refrigerant adjustment amount information.

[0027] Each piece of judgment criterion information represents a relationship between the measurement date and time, the outdoor air temperature, the compressor outlet specific enthalpy value, the threshold value of the compressor outlet specific enthalpy value, and the presence or absence of an abnormality. Each piece of judgment criterion information can be said to be information in which first refrigeration condition information representing the set cooling temperature and the type of refrigerant of the refrigeration circuit is associated with threshold information representing the relationship between the estimated physical quantity threshold and the outdoor air temperature. The threshold is set for each outdoor air temperature or for each predetermined temperature range. In the judgment process of the operating state, the threshold is compared with the compressor outlet specific enthalpy value of the physical quantity information. The presence or absence of an abnormality in the amount of refrigerant is judged based on whether the compressor outlet specific enthalpy value of the physical quantity information is equal to or greater than the threshold. When the compressor outlet specific enthalpy value of the physical quantity information is equal to or greater than the threshold, the amount of refrigerant is judged to be normal because it is equal to or less than the upper limit amount, and when the compressor outlet specific enthalpy value is less than the threshold, the amount of refrigerant is judged to be abnormal because it exceeds the upper limit amount. The threshold is updated based on the physical quantity information.

[0028] For example, the judgment criteria information of the first reference refrigeration device is configured to be represented as a scatter diagram shown in FIG. 2. In FIG. 2, the vertical axis represents the compressor outlet specific enthalpy value, and the horizontal axis represents the outside air temperature. The points indicated by light gray circles represent the compressor outlet specific enthalpy values ​​for which the operating state is determined to be normal. The points indicated by dark gray circles represent the compressor outlet specific enthalpy values ​​for which the operating state is determined to be abnormal. When a threshold value is set for each predetermined range of the outside air temperature, the threshold value is represented as a line parallel to the horizontal axis in the scatter diagram (shown by a solid line in FIG. 2). Note that the distribution of the compressor outlet specific enthalpy values ​​for which the operating state is determined to be normal may be referred to as a "normal distribution," and the distribution of the compressor outlet specific enthalpy values ​​for which the operating state is determined to be abnormal may be referred to as an "abnormal distribution."

[0029] In this way, by storing multiple pieces of judgment information regarding refrigeration devices which differ from each other in at least one of the set cooling temperatures and the refrigerant in the database 54, it is possible to use a single operating state judgment device 5 to judge the operating state of multiple refrigeration circuits 20 which differ from each other in at least one of the set cooling temperatures and the refrigerant.

[0030] The refrigerant adjustment amount information is used to determine the refrigerant adjustment amount when it is determined that an operating condition is abnormal. The refrigerant adjustment amount information represents the relationship between the refrigerant adjustment amount and a difference (specific enthalpy difference) obtained by subtracting the compressor outlet specific enthalpy value of the physical quantity information from a threshold value for each outside air temperature. The refrigerant adjustment amount is set to be larger as the specific enthalpy difference is larger. The refrigerant adjustment amount information may be information with a table structure indicating the relationship between the specific enthalpy difference and the refrigerant adjustment amount, or may be information representing a function for calculating the refrigerant adjustment amount.

[0031] The control unit 55 has a CPU (Central Processing Unit), and realizes the functions of the control unit 55 by the CPU executing a driving state determination program stored in the storage unit 53. The control unit 55 includes an acquisition unit 551, a calculation unit 552, an estimation unit 553, a determination unit 554, an update unit 555, and a notification control unit 556.

[0032] The acquisition unit 551 acquires the measurement information from the measurement unit 4 .

[0033] The calculation unit 552 calculates a chiller inlet specific enthalpy value, a chiller inlet specific entropy value, and a condenser outlet specific enthalpy value based on the measurement information. The chiller inlet specific enthalpy value and the chiller inlet specific entropy value are the specific enthalpy value and the specific entropy value of the refrigerant at the chiller inlet P1, respectively. The condenser outlet specific enthalpy value is the specific enthalpy value of the refrigerant at the condenser outlet P2.

[0034] The estimation unit 553 estimates the compressor outlet specific enthalpy value based on the measurement information. For example, the estimation unit 553 estimates the compressor outlet specific enthalpy value using an isogeometric entropy line obtained based on the chiller inlet specific entropy value and the condenser outlet pressure based on the Mollier diagram of the refrigeration circuit 20 shown in Fig. 3. The estimation unit 553 associates the compressor outlet specific enthalpy value with the measurement date and time and the outside air temperature, and stores them in the storage unit 53 as physical quantity information. In Fig. 3 and Fig. 7 described later, filled circles represent measurement results and calculation results at measurement positions, and open circles represent estimation results at unmeasured positions estimated by the estimation unit 553.

[0035] The determination unit 554 determines the presence or absence of an abnormality in the amount of refrigerant and the amount of refrigerant adjustment as the operating state of the refrigeration circuit 20, based on the measurement information, the target circuit information indicating the set cooling temperature and refrigerant of the refrigeration circuit 20, and the determination information corresponding to the set cooling temperature and refrigerant indicated by the target circuit information. The target circuit information may be generated based on an operation of an operation unit (not shown) of the refrigeration device 2 and transmitted from the refrigeration device 2 to the operating state determination device 5, or may be generated based on an operation of the operation unit 51 of the operating state determination device 5.

[0036] Here, in the refrigeration circuit 20, when the set cooling temperature and the refrigerant are determined, there is a relationship in which an appropriate value of a physical quantity obtained based on the temperature and pressure at a predetermined measurement position is determined (hereinafter, sometimes referred to as "correlation between refrigeration conditions and physical quantities"). The appropriate value depends greatly on the set cooling temperature and the refrigerant, but hardly depends on the specifications of the refrigeration circuit 20 such as the compressor 21. The determination unit 554 determines the operating state of the refrigeration circuit 20 based on the measurement information, the target circuit information, and the judgment reference information of the judgment information. The judgment reference information can also be said to be information that represents an example of the correlation between the refrigeration conditions and the physical quantities. In this way, the determination unit 554 determines the operating state without using, for example, a characteristic parameter corresponding to the type of the compressor 21 that can be used, and therefore can appropriately determine the operating state of the refrigeration circuit 20 with a simple configuration regardless of the specifications of the refrigeration circuit 20.

[0037] The update unit 555 updates the threshold value of the determination criterion information based on the latest determination result of the presence or absence of an abnormality and the past determination results of the presence or absence of an abnormality. In this way, by updating the threshold value of the determination criterion information every time the presence or absence of an abnormality is determined, it is possible to set a threshold value that matches the specifications of the refrigeration device 2, and it is possible to appropriately determine the presence or absence of an abnormality based on the threshold value that matches the specifications of the refrigeration device 2.

[0038] The notification control unit 556 controls the notification unit 52 to notify the presence or absence of an abnormality in the refrigerant amount and the determination result of the refrigerant adjustment amount by the determination unit 554. In this manner, the refrigerant adjustment amount is notified, so that the user can easily adjust the refrigerant amount in the refrigeration circuit 20.

[0039] (Refrigeration system operation) Next, the operation of the refrigeration system will be described based on the flowcharts shown in Figures 4 to 6. Figure 4 is a flowchart of a main routine of the operating state determination process. Figures 5 and 6 are flowcharts of subroutines of the operating state determination process.

[0040] As shown in Fig. 4, the control unit 55 of the driving state determination device 5 performs a process of collecting physical quantity information (step S1). Next, the control unit 55 performs a process of determining the driving state based on the physical quantity information (step S2). Thereafter, the control unit 55 notifies the result of the determination (step S3). Finally, the control unit 55 updates the determination criterion information (step S4). The details of each process will be described below. Note that the control unit 55 may perform the process of step S4 before performing the process of step S3.

[0041] First, the process of collecting physical quantity information in step S1 will be described. The measurement unit 4 performs measurement, for example, periodically or at a predetermined time, and outputs measurement information corresponding to the measurement result to the control unit 55 (step S11). As shown in FIG. 5, the acquisition unit 551 of the control unit 55 acquires measurement information representing the refrigerator inlet temperature, the refrigerator inlet pressure, the condenser outlet temperature, the condenser outlet pressure, and the outside air temperature from the measurement unit 4 (step S11). Next, the calculation unit 552 calculates the refrigerator inlet specific enthalpy value and the refrigerator inlet specific entropy value based on the refrigerator inlet temperature and the refrigerator inlet pressure (step S12). Next, the calculation unit 552 calculates the condenser outlet specific enthalpy value based on the condenser outlet temperature and the condenser outlet pressure (step S13). Note that the calculation unit 552 may perform the process of step S13 before performing the process of step S12.

[0042] Next, the estimation unit 553 estimates the compressor outlet specific enthalpy value (step S14). The estimation unit 553 acquires the measurement date and time from a timer unit (not shown), associates the compressor outlet specific enthalpy value with the measurement date and time, and the outside air temperature, and stores them in the storage unit 53 as physical quantity information (step S15).

[0043] The determination unit 554 determines whether or not to start the determination process (step S16). When the determination unit 554 determines not to start the determination process (step S16: NO), the acquisition unit 551 acquires measurement information representing a result of a measurement performed at a time different from the previous measurement from the measurement unit 4 (step S11). Every time the processes of steps S11 to S15 are performed, physical quantity information based on the measurement result at a different date and time is stored in the storage unit 53. On the other hand, when the determination unit 554 determines to start the determination process (step S16: YES), the collection process of the physical quantity information is terminated. Note that the determination unit 554 may determine to start the determination process when it detects an operation of the operation unit 51 by the user, or may determine to start the determination process when the number of pieces of physical quantity information stored in the storage unit 53 reaches a set number.

[0044] Next, the determination process in step S2 will be described. As shown in Fig. 6, the determination unit 554 acquires the target circuit information, and selects, from the database 54, determination information corresponding to the set cooling temperature and refrigerant represented by the target circuit information, that is, determination information related to a reference refrigeration device having the same set cooling temperature and refrigerant as the refrigeration device 2 (step S21).

[0045] Next, the determination unit 554 determines whether the distribution of the compressor outlet specific enthalpy values ​​of all the physical quantity information stored in the storage unit 53 is closer to a normal distribution or an abnormal distribution (step S22). For example, the determination unit 554 compares the compressor outlet specific enthalpy value of the physical quantity information with a threshold value included in the determination criterion information and corresponding to the outside air temperature of the physical quantity information. When a plurality of pieces of physical quantity information corresponding to a plurality of measurement results in a predetermined period are stored in the storage unit 53, the determination unit 554 performs the above-mentioned comparison process on all the physical quantity information. When the number of the compressor outlet specific enthalpy values ​​determined to be equal to or greater than the threshold value is greater than the number of the compressor outlet specific enthalpy values ​​determined to be less than the threshold value, the determination unit 554 determines that the distribution of the compressor outlet specific enthalpy values ​​is closer to a normal distribution. On the other hand, when the number of compressor outlet specific enthalpy values ​​determined to be equal to or greater than the threshold value is smaller than the number of compressor outlet specific enthalpy values ​​determined to be less than the threshold value, the determination unit 554 determines that the distribution of the compressor outlet specific enthalpy values ​​is close to an abnormal distribution. Note that the method of determining whether the distribution of the compressor outlet specific enthalpy values ​​is close to a normal distribution or an abnormal distribution is not limited to the above-described method.

[0046] When the determination unit 554 determines in step S22 that the distribution of the compressor outlet specific enthalpy values ​​is close to a normal distribution, the amount of refrigerant is normal and therefore the operating state is normal (step S23). On the other hand, when the determination unit 554 determines in step S22 that the distribution of the compressor outlet specific enthalpy values ​​is close to an abnormal distribution, the amount of refrigerant is excessive and therefore the operating state is abnormal (step S24). That is, the determination unit 554 determines whether or not there is an abnormality over the entire predetermined period, alternatively, based on the distribution of the compressor outlet specific enthalpy values ​​determined to be equal to or greater than the threshold value by the processing in step S23 or step S24 and the distribution of the compressor outlet specific enthalpy values ​​determined to be less than the threshold value. In this way, the presence or absence of an abnormality in the predetermined period is determined alternatively based on the compressor outlet specific enthalpy values ​​based on a plurality of measurement results, rather than for each compressor outlet specific enthalpy value based on a plurality of measurement results, thereby reducing the load of the process of determining whether or not there is an abnormality.

[0047] Here, as shown in FIG. 2, the threshold value (appropriate value) of the compressor outlet specific enthalpy value may differ depending on the outdoor air temperature. The determination unit 554 compares the compressor outlet specific enthalpy value of the physical quantity information with the threshold value corresponding to the outdoor air temperature of the physical quantity information. For this reason, for example, when the refrigeration device 2 is installed in a place where the outdoor air temperature is likely to change, the presence or absence of an abnormality can be appropriately determined by comparing the compressor outlet specific enthalpy value with the threshold value corresponding to the outdoor air temperature. In addition, as the compressor outlet specific enthalpy value to be compared with the threshold value, an estimated value obtained based on the measurement results at the refrigerator inlet P1 and the condenser outlet P2 is used, rather than a calculated value obtained based on the measurement results of the refrigerant temperature and pressure at the compressor outlet P3. For this reason, the determination unit 554 can appropriately determine the presence or absence of an abnormality based on the measurement results at the minimum measurement positions.

[0048] When the determination unit 554 determines that the operating state is abnormal (step S24), it calculates the refrigerant adjustment amount (step S25). For example, the determination unit 554 uses physical quantity information corresponding to an arbitrary measurement date and time to subtract the compressor outlet specific enthalpy value of the physical quantity information from a threshold corresponding to the outside air temperature of the physical quantity information to calculate a specific enthalpy difference. The determination unit 554 calculates the refrigerant adjustment amount based on the calculated specific enthalpy difference and the refrigerant adjustment amount information. Note that the calculation method of the refrigerant adjustment amount is not limited to the above-mentioned method. For example, the determination unit 554 may calculate the specific enthalpy difference by subtracting the compressor outlet specific enthalpy value of the physical quantity information from a threshold corresponding to the outside air temperature of the physical quantity information for each of all the outside air temperatures obtained by the measurement of the measurement unit 4, and calculate the refrigerant adjustment amount based on the average value of the calculated specific enthalpy differences and the refrigerant adjustment amount information. In addition, the determination unit 554 may perform the process of step S25 and then the process of step S24.

[0049] When the process of step S23 or step S25 is performed, the determination process of step S2 ends.

[0050] Next, a process of notifying the result of the determination in step S3 will be described. When the process of step S23 is performed in the determination process, the notification control unit 556 notifies the fact that the operating state is normal using the notification unit 52, and when the processes of steps S24 and S25 are performed, the notification control unit 556 notifies the fact that the operating state is abnormal and the refrigerant adjustment amount using the notification unit 52. Note that instead of or together with the refrigerant adjustment amount, the notification control unit 556 may calculate a ratio of the refrigerant adjustment amount to the current refrigerant amount and notify it as the determination result of the operating state.

[0051] Next, the update process of the judgment criteria information in step S4 will be described. The update unit 555 updates the judgment criteria information related to the reference refrigeration device having the same set cooling temperature and refrigerant as the refrigeration device 2. When the update unit 555 determines that the operating state of the refrigeration circuit 20 is normal, the update unit 555 generates update information in which the physical quantity information is associated with information indicating that there is no abnormality, regardless of whether the compressor outlet specific enthalpy value of the physical quantity information is equal to or greater than the threshold value corresponding to the outside air temperature of the physical quantity information. On the other hand, when the update unit 555 determines that the operating state is abnormal, the update unit 555 generates update information in which the physical quantity information is associated with information indicating that there is an abnormality, regardless of whether the compressor outlet specific enthalpy value of the physical quantity information is equal to or greater than the threshold value corresponding to the outside air temperature of the physical quantity information.

[0052] Next, the update unit 555 calculates a threshold value for each outside air temperature based on the update information including the latest determination result of the presence or absence of an abnormality and the determination criterion information including the past determination results of the presence or absence of an abnormality. An example of a method of calculating the threshold value is a compressor outlet specific enthalpy value with a conformance rate of 99% or more for determining that the operating state is normal in an information group including the update information and the determination criterion information, or a 99% percentile value of the compressor outlet specific enthalpy for which the operating state is determined to be normal. Another example of a method of calculating the threshold value is a method of calculating the threshold value based on a recall rate or a correct answer rate.

[0053] The update unit 555 updates the threshold for each outside air temperature included in the judgment criterion information to the newly calculated threshold for each outside air temperature. The update unit 555 adds information in which the update information is associated with a new threshold corresponding to the outside air temperature in the update information to the judgment criterion information. Note that, if a threshold is set for each predetermined range of outside air temperature, the above-mentioned process is performed for each predetermined range of outside air temperature. The update unit 555 deletes the physical quantity information stored in the memory unit 53. Note that the method of updating the judgment criterion information is not limited to the above-mentioned method.

[0054] <Second embodiment> Next, a second embodiment of the present disclosure will be described.

[0055] (Refrigeration system configuration) First, the configuration of the refrigeration system will be described with reference to Fig. 1 and Fig. 7. Note that the same names and symbols are used for the same configurations as those of the refrigeration system 1 of the first embodiment, and the description will be simplified or omitted. Fig. 7 is a Mollier diagram of the refrigeration circuit.

[0056] 1, in the refrigeration system 1A of the second embodiment, the configuration of an operating state determination device 5A is different from the configuration of the operating state determination device 5 of the first embodiment. The operating state determination device 5A performs a process of determining the operating state of the refrigeration circuit 20, a process of evaluating the refrigeration performance of the refrigeration circuit 20, a process of determining a method for improving the refrigeration performance, and a process of determining whether or not there is an abnormality in the amount of refrigerant.

[0057] The differences between the driving state determination device 5A of the second embodiment and the driving state determination device 5 of the first embodiment are the information stored in the memory unit 53A and the database 54A, and the processing contents of the estimation unit 553A, the judgment unit 554A, and the notification control unit 556A that constitute the control unit 55A.

[0058] The storage unit 53A stores various information necessary for controlling the operating state determination device 5A and physical quantity information. The physical quantity information includes information representing the compressor outlet specific enthalpy value and the evaporator inlet specific enthalpy value estimated by the control unit 55A, the refrigerator inlet specific enthalpy value calculated by the control unit 55A, and the measurement date and time. The evaporator inlet specific enthalpy value is the specific enthalpy value of the refrigerant at the evaporator inlet P4 shown in Fig. 1. The evaporator inlet P4 is a predetermined unmeasured position in the pipe 203 connecting the throttling unit 23 and the evaporator 24. After being used in the operating state determination process, the physical quantity information is deleted from the storage unit 53A.

[0059] The multiple pieces of determination information stored in database 54A are information relating to reference refrigeration devices having different cooling temperature settings and / or refrigerants, similar to the determination information in the first embodiment. Each piece of determination information includes determination reference information, refrigerant evaluation information, ideal state information, and performance information.

[0060] Each piece of criterion information has the same configuration as the criterion information in the first embodiment, and is used to determine whether the refrigerant amount is abnormal. The threshold value included in the criterion information is set for each outside air temperature or for each predetermined temperature range. For example, the criterion information is configured so that the threshold value can be expressed together with the Mollier diagram of FIG. 7.

[0061] The refrigerant evaluation information indicates the relationship between the result of the determination of an abnormality in the amount of refrigerant based on the determination criterion information and a method for improving the amount of refrigerant.

[0062] The ideal state information is information that represents ideal values ​​of the refrigerator inlet specific enthalpy value, the condenser outlet specific enthalpy value, the compressor outlet specific enthalpy value, and the evaporator inlet specific enthalpy value. The refrigerator inlet specific enthalpy value is an example of a calculated physical quantity of the present disclosure. The compressor outlet specific enthalpy value and the evaporator inlet specific enthalpy value are examples of an estimated physical quantity of the present disclosure. The ideal values ​​are set for each outside air temperature or for each predetermined temperature range. For example, the ideal state information is configured so as to be expressed as a Mollier diagram shown by a dotted line in FIG. 7. Note that the actual measured values ​​shown in FIG. 7 or the actual measured values ​​described later are calculated values ​​or estimated values ​​obtained based on the measurement results in the measurement unit 4. The ideal state information can also be said to be information in which the second refrigeration condition information that represents the set cooling temperature and the type of refrigerant of the refrigeration circuit, the first ideal value information that represents the relationship between the ideal value of the calculated physical quantity and the outside air temperature, and the second ideal value information that represents the relationship between the ideal value of the estimated physical quantity and the outside air temperature are associated with each other.

[0063] The performance information includes refrigeration effect evaluation information, first energy saving performance (energy conservation performance) evaluation information, and second energy saving performance (energy conservation performance) evaluation information.

[0064] The refrigeration effect evaluation information indicates the relationship between the refrigeration effect difference A, the evaluation of the refrigeration effect, and a method for improving the refrigeration effect. The refrigeration effect difference A is a value calculated by the following formulas (1), (2), and (3). The difference between the chiller inlet specific enthalpy value and the evaporator inlet specific enthalpy value is an index indicating the refrigeration effect. Refrigeration effect difference A = Refrigeration effect actual value Am - Refrigeration effect ideal value Ai … (1) Refrigeration effect measured value Am = Erm - Eem … (2) Erm: Measured value of refrigerator inlet specific enthalpy Eem: Measured value of evaporator inlet specific enthalpy Ideal refrigeration effect Ai = Eri - Eei … (3) Eri: Ideal value of refrigerator inlet specific enthalpy Eei: Ideal value of evaporator inlet specific enthalpy The evaluation of the refrigeration effect is set to be higher as the refrigeration effect difference A becomes smaller. The method of improving the refrigeration effect is a method for bringing the refrigeration effect to an ideal state (a state in which the highest refrigeration effect is obtained).

[0065] The first energy saving performance evaluation information indicates the relationship between the first energy saving performance difference B, the evaluation of the first energy saving performance, and a method for improving the first energy saving performance. The first energy saving performance difference B is a value calculated by the following formulas (4), (5), and (6). The difference between the compressor outlet specific enthalpy value and the chiller inlet specific enthalpy value is a parameter that has a significant effect on the compressor power of the compressor 21. First Energy Saving Performance Difference B = 1st energy saving performance actual value Bm - 1st energy saving performance ideal value Bi … (4) First energy saving performance measured value Bm=Ecm-Erm … (5) Ecm: Actual measured value of compressor outlet specific enthalpy First energy saving performance ideal value Bi=Eci-Eri … (6) Eci: Ideal value of compressor outlet specific enthalpy The evaluation of the first energy efficiency is set to be higher as the first energy efficiency performance difference B becomes smaller. The method of improving the first energy efficiency is a method for bringing the energy efficiency to an ideal state (a state where the highest energy efficiency is obtained).

[0066] The second energy saving performance evaluation information indicates the relationship between the second energy saving performance difference C, the evaluation of the second energy saving performance, and a method for improving the second energy saving performance. The second energy saving performance difference C is a value calculated by the following formula (7). Second energy saving performance difference C=Eem-Eei … (7) The evaluation of the second energy efficiency is set to be higher as the second energy efficiency performance difference C becomes smaller. The method of improving the second energy efficiency is a method for bringing the energy efficiency to an ideal state.

[0067] The estimation unit 553A estimates the compressor outlet specific enthalpy value and the evaporator inlet specific enthalpy value based on the measurement information. For example, the estimation unit 553A estimates the compressor outlet specific enthalpy value by the same process as in the first embodiment based on the Mollier diagram of the refrigeration circuit 20 shown by the solid line in FIG. 7. The estimation unit 553A estimates the evaporator inlet specific enthalpy value using the refrigerator inlet pressure and the condenser outlet specific enthalpy value. The estimation unit 553A associates the compressor outlet specific enthalpy value, the evaporator inlet specific enthalpy value, the refrigerator inlet specific enthalpy value, the measurement date and time, and the outside air temperature, and stores them in the storage unit 53A as physical quantity information. The compressor outlet specific enthalpy value, the evaporator inlet specific enthalpy value, and the refrigerator inlet specific enthalpy value constituting the physical quantity information correspond to the actual measurement values ​​in FIG. 7, respectively.

[0068] The judgment unit 554A judges the operating state of the refrigeration circuit 20 based on the measurement information, the target circuit information representing the set cooling temperature and refrigerant of the refrigeration circuit 20, and the judgment information corresponding to the set cooling temperature and refrigerant represented by the target circuit information, and judges the refrigeration performance of the refrigeration circuit 20, a method for improving the refrigeration performance, and whether or not there is an abnormality in the amount of refrigerant.

[0069] The notification control unit 556A controls the notification unit 52 to notify the evaluation of the refrigeration performance by the determination unit 554A, the method for improving the refrigeration performance, and the determination result of whether or not there is an abnormality in the amount of refrigerant. In this way, the evaluation and the method for improving the refrigeration performance, and the presence or absence of an abnormality in the amount of refrigerant are notified, so that the user can easily recognize the evaluation of the refrigeration performance of the refrigeration circuit 20, the method for improving the refrigeration performance, and the presence or absence of an abnormality in the amount of refrigerant, and can take measures to operate the refrigeration circuit 20 appropriately.

[0070] (Refrigeration system operation) Next, the operation of the refrigeration system will be described based on the flowcharts shown in Figures 5, 8 and 9. Note that the same operations as those in the refrigeration system 1 of the first embodiment are given the same names and symbols, and the explanation will be simplified or omitted. Figure 8 is a flowchart of a main routine of the operating state determination process. Figure 9 is a flowchart of a subroutine of the operating state determination process.

[0071] As shown in Fig. 8, the control unit 55A of the driving state determination device 5A performs a process of collecting physical quantity information (step S31). Next, the control unit 55A performs a process of determining the driving state based on the physical quantity information (step S32). After that, the control unit 55A notifies the result of the determination (step S33). The details of each process will be described below. Note that in the second embodiment, the process of updating the determination criterion information is not performed based on the physical quantity information, but the process of updating the determination criterion information may be performed similarly to step S4 in the first embodiment.

[0072] First, the process of collecting physical quantity information in step S31 will be described. As shown in Fig. 5, the control unit 55A performs the processes of steps S11 to S13 similar to those in the first embodiment, and then estimates the compressor outlet specific enthalpy value and the evaporator inlet specific enthalpy value as physical quantities at unmeasured positions (step S41). The estimation unit 553A associates the compressor outlet specific enthalpy value, the evaporator inlet specific enthalpy value, the refrigerator inlet specific enthalpy value, and the measurement date and time, and stores them in the storage unit 53A as physical quantity information (step S42).

[0073] The determination unit 554A determines whether or not to start the process of determining the driving state (step S16). The control unit 55A performs processing based on the result of the determination in step S16.

[0074] Next, the determination process in step S32 will be described. As shown in Fig. 9, determining unit 554A selects, from database 54A, determination information relating to a reference refrigeration device having the same set cooling temperature and refrigerant as refrigeration device 2 (step S21).

[0075] The judgment unit 554A judges the evaluation of the refrigeration effect and a method for improving it based on the physical quantity information and the refrigeration effect evaluation information of the judgment information (step S51). The judgment unit 554A calculates the refrigeration effect difference A based on the physical quantity information and the above formulas (1) to (3). The judgment unit 554A judges the evaluation of the refrigeration effect and a method for improving it based on the calculated refrigeration effect difference A and the refrigeration effect evaluation information.

[0076] In the process of step S51, the determination unit 554A may calculate a refrigeration effect difference A based on physical quantity information corresponding to an arbitrary measurement date and time, and determine an evaluation of the refrigeration effect and a method of improvement based on the calculated refrigeration effect difference A. The determination unit 554A may calculate a refrigeration effect difference A corresponding to each outside air temperature of all physical quantity information, and determine an evaluation of the refrigeration effect and a method of improvement based on an average value of these refrigeration effect differences A.

[0077] The determination unit 554A determines an energy saving evaluation and an improvement method based on the physical quantity information and the first energy saving information and second energy saving evaluation information of the determination information (step S52). The determination unit 554A calculates a first energy saving performance difference B based on the physical quantity information and the above formulas (4) to (6). The determination unit 554A calculates a second energy saving performance difference C based on the physical quantity information and the above formula (7). The determination unit 554A determines an energy saving evaluation and an improvement method based on the calculated first and second energy saving performance differences B and C and the first and second energy saving evaluation information.

[0078] Note that in the process of step S52, the determination unit 554A may calculate the first and second energy saving performance differences B and C based on the physical quantity information corresponding to an arbitrary measurement date and time, and determine the energy saving performance evaluation and the improvement method based on the calculated first and second energy saving performance differences B and C. The determination unit 554A may calculate the first and second energy saving performance differences B and C corresponding to the outside air temperatures of all the physical quantity information, respectively, and determine the energy saving performance evaluation and the improvement method based on the average value of the first energy saving performance difference B and the average value of the second energy saving performance difference C.

[0079] In this way, the determination unit 554A evaluates the refrigeration effect and energy saving performance, and determines a method for improving the refrigeration effect and energy saving performance, based on the physical quantities (specific enthalpy values) at three positions (refrigeration machine inlet P1, compressor outlet P3, and evaporator inlet P4) obtained from the measurement results at two measurement positions (refrigeration machine inlet P1 and condenser outlet P2). Therefore, the determination unit 554A can perform various evaluations based on the measurement results at the minimum number of measurement positions.

[0080] The determination unit 554A determines whether the refrigerant amount is abnormal and how to improve it based on the physical quantity information and the determination reference information of the determination information (step S53). When the compressor outlet specific enthalpy value of the physical quantity information is equal to or greater than a threshold value corresponding to the outside air temperature of the physical quantity information, the determination unit 554A determines that the refrigerant amount is normal, and when it is less than the threshold value, determines that the refrigerant amount is abnormal (excessive). The determination unit 554A determines how to improve the refrigerant amount based on the determination result of the abnormality of the refrigerant amount and the refrigerant evaluation information.

[0081] In the process of step S53, the determination unit 554A may determine an abnormality in the refrigerant amount based on physical quantity information corresponding to an arbitrary measurement date and time and a threshold value corresponding to the outside air temperature included in the physical quantity information. The determination unit 554A may determine an abnormality in the refrigerant amount for all physical quantity information based on the compressor outlet specific enthalpy value and a threshold value corresponding to the outside air temperature included in each piece of physical quantity information, and may determine that the amount of physical quantity information is abnormal if the number of pieces of physical quantity information determined to be abnormal is greater than the number of pieces of physical quantity information determined to be normal, and may determine that the amount of physical quantity information is normal if the number of pieces of physical quantity information determined to be abnormal is greater than the number of pieces of physical quantity information determined to be normal.

[0082] After the process of step S53 is performed, the determination unit 554A deletes the physical quantity information from the storage unit 53A. This ends the operating state determination process of step S33. Note that, if the above-mentioned ideal values ​​and threshold values ​​are set for each predetermined range of outside air temperature, the processes of steps S51 to S53 described above are performed for each predetermined range of outside air temperature. Also, the processing order of steps S51 to S53 is not limited to the order described above.

[0083] Next, the notification process of the result of the determination in step S33 will be described. The notification control unit 556A controls the notification unit 52 to notify the result of the operating state determination process. In the second embodiment, the notification control unit 556A notifies the evaluation and improvement method of the refrigeration effect, the evaluation and improvement method of the energy saving performance, and the presence or absence of an abnormality in the amount of refrigerant. For example, the notification control unit 556A performs the following notification in accordance with the determination result of the determination unit 554A based on the actual measurement value as shown in FIG. 7.

[0084] The judgment unit 554A judges that the evaluation of the refrigeration effect is a small level negative evaluation because the refrigeration effect difference A is a negative value. In this case, the notification control unit 556A notifies the evaluation of the refrigeration effect shown below, but does not notify any improvement method because the evaluation is not very low. (Evaluation of freezing effect) "There are no current issues, but we are seeing a slight decrease in the cooling effect. We will be keeping a close eye on the cooling situation during hotter periods."

[0085] Because first energy saving performance difference B is a negative value, the determination unit 554A determines that the evaluation of energy saving performance based on first energy saving performance difference B is a small level negative evaluation. Because second energy saving performance difference C is a positive value, the rotation speed of a fan (not shown) of condenser 22 is high, and the condenser outlet temperature is high, the determination unit 554A determines that the evaluation of energy saving performance based on second energy saving performance difference C is a medium level negative evaluation. In these cases, the notification control unit 556A notifies the following energy saving performance evaluation and improvement method based on these energy saving performance evaluation results. (Energy saving rating) "The condenser temperature is particularly high, and the condenser fan is suspected to be running at high speed or malfunctioning." (Methods for improving energy efficiency) "Check the condition of the condenser and condenser fan. Clean the condenser if it is dirty."

[0086] The notification control unit 556A notifies the user of the following improvement method based on the determination result by the determination unit 554A that there is an abnormality in the amount of refrigerant. (How to improve the amount of refrigerant) "Refrigerant purging is recommended due to excess refrigerant."

[0087] <Third embodiment> Next, a third embodiment of the present disclosure will be described.

[0088] (Refrigeration system configuration) First, the configuration of the refrigeration system will be described with reference to Fig. 1. Note that the same names and symbols are used for the same configurations as those of the refrigeration system 1 of the first embodiment, and descriptions thereof will be simplified or omitted.

[0089] As shown in FIG. 1, in the refrigeration system 1B of the third embodiment, the configuration of the operating state determination device 5B is different from that of the operating state determination device 5 of the first embodiment. The operating state determination device 5B performs the same process as in the first embodiment to determine the presence or absence of an abnormality in the amount of refrigerant and the amount of refrigerant adjustment as well as the process to determine the reliability of the determination result. That is, the operating state determination device 5B of the third embodiment has a configuration in which a function to perform a process to determine the reliability of the determination result of the operating state is added to the operating state determination device 5 of the first embodiment. Note that a function to perform a process to determine the reliability of the determination result of the operating state may be added to the operating state determination device 5A of the second embodiment.

[0090] A driving state determination device 5B of the third embodiment differs from the driving state determination device 5 of the first embodiment in the processing contents of a determination unit 554B, an update unit 555B, and a notification control unit 556B that constitute a control unit 55B.

[0091] The judgment unit 554B judges the presence or absence of an abnormality and the refrigerant adjustment amount based on at least one of the measurement date and time represented by the measurement information and the trend of the compressor outlet ratio entropy value, and also judges at least the reliability of the judgment result and the reliability of the factors that reduce the reliability.

[0092] The update unit 555B updates the judgment criterion information based on the reliability of the judgment result by the judgment unit 554B. If the update unit 555B judges that the reliability of the judgment result is high, the update unit 555B updates the judgment criterion information based on the information used in the judgment. On the other hand, if the update unit 555B judges that the reliability of the judgment result is low, the update unit 555B does not update the judgment criterion information.

[0093] The notification control unit 556B controls the notification unit 52 to notify the above-described determination result by the determination unit 554B. In this way, by notifying at least the presence or absence of an abnormality and the reliability of the determination result of the refrigerant adjustment amount, the user can easily determine how much to trust the determination result by the determination unit 554B.

[0094] (Refrigeration system operation) Next, the refrigeration system will be described based on the flowchart shown in Fig. 10. Note that the same operations as those in the refrigeration system 1 of the first embodiment are given the same names and symbols, and the explanations are simplified or omitted. Fig. 10 is a flowchart of a main routine of the operating state determination process.

[0095] As shown in FIG. 10, the driving state determination device 5B performs the same physical quantity information collection process (step S1) and driving state determination process (step S2) as in the first embodiment. Next, the control unit 55B of the driving state determination device 5B determines the reliability of the driving state determination result (step S61). After that, the control unit 55B notifies the driving state determination result and its reliability (step S62). Next, the update unit of the control unit 55B determines whether the reliability of the determination result is high or not (step S63). When the control unit 55B determines that the reliability of the determination result is high (step S63: YES), it updates the determination criterion information (step S4). On the other hand, when the control unit 55B determines that the reliability of the determination result is low (step S63: NO), it does not update the determination criterion information. The details of each process will be described below. Note that the control unit 55B may perform the processes of steps S63 and S4 before the process of step S61 or step S62.

[0096] First, a description will be given of the process of determining the reliability of the determination result in step S61. The determination unit 554B determines the reliability based on the content of the physical quantity information used in the process of determining the operating state in step S2.

[0097] For example, the determination unit 554B may determine that the reliability is low when the measurement period for obtaining a plurality of pieces of physical quantity information (the period from the oldest date and time to the newest date and time of measurement among the plurality of pieces of physical quantity information) is shorter than a predetermined period, and may determine that the reliability is high when the measurement period is longer than the predetermined period. The reason for determining that the reliability is low when the measurement period is shorter than the predetermined period is that when an inaccurate measurement result is temporarily obtained, the number of data used in the driving state determination process is small, and therefore the inaccurate measurement result is likely to affect the determination result of the driving state. From this viewpoint, the determination unit 554B may determine that the reliability is low when the number of pieces of physical quantity information is smaller than a predetermined number, and may determine that the reliability is high when the number of pieces of physical quantity information is greater than the predetermined number.

[0098] For example, the determination unit 554B may determine that the reliability is low when the number of singular points is more than a predetermined number based on the transition state of the compressor outlet specific enthalpy value in the plurality of pieces of physical quantity information, and may determine that the reliability is high when the number of singular points is less than the predetermined number. The reason for determining that the reliability is low when the number of singular points is more than a predetermined number is that, since there is a possibility that a temporary trouble has occurred in the refrigeration device 2 or the measurement unit 4, even if the current situation has been resolved from the trouble, an inaccurate measurement result based on the temporary trouble is likely to affect the determination result of the operating state. For example, the memory unit 53 may store information that the refrigeration device 2 has been stopped in an emergency, and that maintenance or defrosting of the refrigeration device 2 has been performed, and if such an emergency stop or the like has occurred within the measurement period, the determination unit 554B may determine that the reliability is low. Note that, when the number of singular points is more than a predetermined number, or when an emergency stop or the like has occurred, the measurement result at the time of the singular point or the emergency stop or the like may be excluded, and the operating state may be re-determined. The reliability may be evaluated in three or more ranks, or may be evaluated by points.

[0099] Next, the process of notifying the determination result of the operating state and the reliability in step S62 will be described. The control unit 55B controls the notifying unit 52 to notify the same determination result and reliability as in the first embodiment. The notified reliability may include the level of reliability and factors that reduce the reliability. Examples of factors that reduce the reliability include the measurement period being shorter than a predetermined period, the presence of more than a predetermined number of singular points in the transition of the compressor outlet specific enthalpy value, and the fact that maintenance or defrosting of the refrigeration device 2 has been performed.

[0100] <Fourth embodiment> Next, a fourth embodiment of the present disclosure will be described.

[0101] (Refrigeration system configuration) First, the configuration of the refrigeration system will be described using Figures 1, 11A, and 11B. The same components as those in the refrigeration system 1 of the first embodiment are given the same names and symbols, and descriptions will be simplified or omitted. Figure 11A is a diagram explaining the configuration of the judgment criteria information of a first model reference refrigeration device using a scatter diagram. Figure 11B is a diagram explaining the configuration of the judgment criteria information of a second model reference refrigeration device using a scatter diagram.

[0102] As shown in FIG. 1, the refrigeration system 1C of the fourth embodiment has an operating state determination device 5C with a different configuration from that of the operating state determination device 5 of the first embodiment. The operating state determination device 5C performs the same process of determining whether or not there is an abnormality in the amount of refrigerant and the amount of refrigerant adjustment as in the first embodiment, using determination information according to the model of the refrigeration device 2. When the operating state determination device 5C determines that the reliability of the threshold included in the determination criterion information according to the model of the refrigeration device 2 is low, it performs the process of determining whether or not there is an abnormality in the amount of refrigerant based on the determination criterion information according to the model of the refrigeration device 2 and the determination criterion information of another model with a high threshold reliability. That is, the operating state determination device 5C of the fourth embodiment has a configuration in which a function of determining the operating state using the determination information according to the model of the refrigeration device 2 and a function of determining the operating state using the determination criterion information of another model when the reliability of the threshold included in the determination criterion information according to the model of the refrigeration device 2 is low are added to the operating state determination device 5 of the first embodiment. Note that these functions may be added to the operating state determination devices 5A and 5B of the second and third embodiments. Further, refrigeration apparatuses of different models refer to refrigeration apparatuses in which the types, sizes, shapes, etc. of components of the refrigeration circuit (compressor, condenser, throttle section, evaporator, piping, etc.) are different from each other.

[0103] The differences between the driving state determination device 5C of the fourth embodiment and the driving state determination device 5 of the first embodiment are the information stored in the memory unit 53C and the database 54C, and the processing contents of the estimation unit 553C, the judgment unit 554C, and the update unit 555C that constitute the control unit 55C.

[0104] The storage unit 53C stores various information necessary for controlling the operating state determination device 5C and physical quantity information. The physical quantity information includes the compressor outlet specific enthalpy value estimated by the control unit 55C, the outside air temperature measured by the measurement unit 4, the date and time of measurement by the measurement unit 4, and information indicating the model of the refrigeration device 2. The physical quantity information is used in the determination process of the operating state and the update process of the determination criterion information, and is then deleted from the storage unit 53C.

[0105] The database 54C stores a plurality of pieces of determination information related to reference refrigeration devices that differ from each other in at least one of the model, refrigerant, and set cooling temperature of the refrigeration device 2. Each piece of determination information includes determination reference information and refrigerant adjustment amount information, each having the same configuration as in the first embodiment.

[0106] For example, the judgment criteria information of the first model of reference refrigeration device is configured to be represented as a scatter diagram shown in FIG. 11A. The judgment criteria information of the second model of reference refrigeration device is configured to be represented as a scatter diagram shown in FIG. 11B. The set cooling temperatures and refrigerants in the first and second models of reference refrigeration devices are the same. The points represented by light gray circles and dark gray circles in the scatter diagrams of FIG. 11A and FIG. 11B have the same meanings as the points in the scatter diagram of FIG. 2. Moreover, the lines parallel to the horizontal axis in the scatter diagrams represent threshold values.

[0107] The estimation unit 553C associates the compressor outlet specific enthalpy value, the outside air temperature, the measurement date and time, and the model, and stores them as physical quantity information in the storage unit 53C. Note that the estimation unit 553C may identify the model of the refrigeration device 2 based on, for example, an input operation of the operation unit 51 by the user.

[0108] The judgment unit 554C judges the presence or absence of an abnormality in the amount of refrigerant and the amount of refrigerant adjustment based on judgment information corresponding to the model of the refrigeration device 2, the set cooling temperature, and the refrigerant.

[0109] The update unit 555C updates the thresholds of the determination criteria information according to the model of the refrigeration device 2, the set cooling temperature, and the refrigerant.

[0110] (Refrigeration system operation) Next, the operation of the refrigeration system will be described based on the flowcharts of Figures 4 to 6 and Figure 12. Note that the same operations as those in the refrigeration system 1 of the first embodiment are given the same names and symbols, and the explanation will be simplified or omitted. Figure 12 is a flowchart of a subroutine for the operating state determination process.

[0111] As shown in FIG. 4, the control unit 55C of the driving state determination device 5C performs a process of collecting physical quantity information (step S71). Next, the control unit 55C performs a process of determining the driving state (step S72). Thereafter, the control unit 55C notifies the determination result of the driving state (step S3) as in the first embodiment. Finally, the control unit 55C updates the determination criterion information of the model (target model) that is the target of the driving state determination (step S73). The details of each process will be described below. The control unit 55C may perform the process of step S73 before the process of step S3.

[0112] First, the process of collecting physical quantity information in step S71 will be described. As shown in Fig. 5, the control unit 55C performs the processes of steps S11 to S14 similar to those in the first embodiment. After that, the estimation unit 553C associates the compressor outlet specific enthalpy value, the outside air temperature, the measurement date and time, and the model, and stores them as physical quantity information in the storage unit 53C (step S81).

[0113] Next, the determination process in step S72 will be described. As shown in Fig. 12, determination unit 554C selects, from database 54C, determination information for a reference refrigeration device having the same model, refrigerant, and set cooling temperature as refrigeration device 2, as determination information for the target model (step S91).

[0114] The determination unit 554C determines whether the reliability of the determination criterion information included in the determination information of the selected target model is high (step S92).

[0115] Here, if the set cooling temperature and refrigerant of different models of refrigeration devices are the same, the appropriate values ​​of physical quantities (e.g., compressor outlet specific entropy value) at predetermined positions in the refrigeration circuits of these refrigeration devices will be approximately the same. However, in the examples shown in Figures 11A and 11B, the distribution and thresholds of the compressor outlet specific entropy value in a part of the temperature range are different from each other. In such a case, it is considered that the reliability of the distribution and thresholds of the compressor outlet specific entropy value in one of the examples shown in Figures 11A and 11B is low.

[0116] For example, the determining unit 554C determines that the reliability of the determination criterion information of the target model is high when, in each temperature range, most of the compressor outlet specific enthalpy values ​​constituting the normal distribution are greater than the threshold value and most of the compressor outlet specific enthalpy values ​​constituting the abnormal distribution are smaller than the threshold value as shown in Fig. 11A. On the other hand, the determining unit 554C determines that the reliability of the determination criterion information of the target model is low when, in at least a part of the temperature range (the low-temperature temperature range in Fig. 11B), most of the compressor outlet specific enthalpy values ​​constituting the abnormal distribution cannot be considered to be smaller than the threshold value as shown in Fig. 11B, or when, although not shown, most of the compressor outlet specific enthalpy values ​​constituting the normal distribution cannot be considered to be greater than the threshold value.

[0117] When the determination unit 554C determines that the reliability of the judgment criterion information of the target model is high (step S92: YES), it selects the judgment criterion information of the target model as the judgment criterion information to be used in the judgment process (step S93). On the other hand, when the determination unit 554C determines that the reliability of the judgment criterion information of the target model is low (step S92: NO), it selects judgment information (judgment information of a non-target model) related to a reference refrigeration device that is different from the refrigeration device 2 only in the model among the model, refrigerant, and set cooling temperature (step S94). The determination unit 554C judges whether the reliability of the judgment criterion information of the selected non-target model is high or not (step S95). The judgment method in step S95 is the same as the judgment method in step S92.

[0118] When the determination unit 554C determines that the reliability of the judgment criterion information of the non-target model is low (step S95: NO), it performs the process of step S94 again. When the process of step S94 is performed twice or more, the determination unit 554C selects judgment information of different models in each process. On the other hand, when the determination unit 554C determines that the reliability of the judgment information of the non-target model is high (step S95: YES), it generates corrected judgment criterion information by correcting the threshold value of the judgment criterion information of the non-target model determined to be highly reliable in step S95 based on the judgment criterion information of the target model selected in step S91 (step S96).

[0119] In the process of generating the corrected criterion information in step S96, the determination unit 554C calculates, for example, a difference between statistical indices that indicate the tendency of normal distribution and abnormal distribution of the compressor outlet specific enthalpy value in the criterion information of the target model and the criterion information of the non-target model. Examples of the statistical indices used here include each outside air temperature, or each percentile value including the average value, standard deviation, and median of the compressor outlet specific enthalpy value in a predetermined temperature range. The determination unit 554C generates the corrected criterion information by correcting the threshold value in the criterion information of the non-target model based on the difference between the calculated statistical indices. For example, when FIG. 11A shows a distribution represented by the criterion information of the non-target model (distribution of the non-target model) and FIG. 11B shows a distribution represented by the criterion information of the target model (distribution of the target model), the threshold value of the target model is larger than the threshold value of the non-target model in the low temperature range. In this case, as shown in FIG. 11A, the threshold value for the temperature range of the judgment criteria information for the non-target model is corrected to be larger (the threshold value indicated by the solid line is corrected to the threshold value indicated by the dotted line), thereby generating corrected judgment criteria information.

[0120] The determination unit 554C selects the generated corrected criterion information as the criterion information to be used in the determination process (step S97). When the determination unit 554C selects the criterion information to be used in the determination process in the process of step S93 or step S97, the determination unit 554C performs the processes of steps S22 to S25 shown in Fig. 6 using the criterion information or corrected criterion information of the selected target model. When the process of step S23 or step S25 is performed, the determination process in step S72 ends.

[0121] In this way, when the determination unit 554C determines that the reliability of the threshold included in the determination criterion information of the target model is low, the determination unit 554C generates corrected determination criterion information by correcting the highly reliable threshold included in the determination criterion information of the non-target model based on the less reliable threshold of the target model, and determines the operating state based on the corrected determination criterion information. Therefore, even if the reliability of the determination criterion information of the target model is low, the determination unit 554C can appropriately determine the operating state based on the corrected determination criterion information.

[0122] In the process of step S3, the notification control unit 556 notifies the result of the process of step S23 or steps S24 and S25, similarly to the first embodiment.

[0123] Next, the update process of the judgment criterion information of the target model in step S73 will be described. As in the first embodiment, the update unit 555C generates update information based on the measurement result of the target model. Next, the update unit 555C calculates a threshold value for each outside air temperature using the method exemplified in the first embodiment based on the update information and the judgment criterion information of the target model. The update unit 555C updates the threshold value for each outside air temperature included in the judgment criterion information of the target model to the newly calculated threshold value for each outside air temperature. The update unit 555C adds information in which the update information is associated with the threshold value corresponding to the outside air temperature of the update information to the judgment criterion information of the target model, and ends the update process, while deleting the physical quantity information stored in the storage unit 53C.

[0124] [Modifications of the embodiment] Needless to say, the present disclosure is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the present disclosure. Furthermore, the above embodiments and the modifications described below may be combined in any way as long as they function normally.

[0125] <First Modification> As a refrigeration device whose operating state is to be determined by the refrigeration system operating state determination system, a so-called two-stage compression refrigeration device 6 shown in Fig. 13 may be applied. The refrigeration device 6 includes a refrigeration circuit 60 including a low-stage compressor 61, an intercooler 62, a high-stage compressor 63, a condenser 64, a first throttling section 65, a gas-liquid separator 66, a second throttling section 67, and an evaporator 24. The low-stage compressor 61 boosts the low-pressure refrigerant introduced from a pipe 609 to an intermediate pressure and sends it to a pipe 601. The intercooler 62 cools the intermediate-pressure refrigerant from the low-stage compressor 61 and sends it to a pipe 602. The high-stage compressor 63 boosts the intermediate-pressure refrigerant from the intercooler 62 to a high pressure and sends it to a pipe 603. The condenser 64 cools the high-pressure refrigerant from the high-stage compressor 63 and sends it to a pipe 604. The first throttling section 65 throttles the refrigerant cooled by the condenser 64, turns it into a gas-liquid mixed state, and sends it to the piping 605. The gas-liquid separator 66 temporarily stores the gas-liquid mixed state refrigerant from the first throttling section 65, and separates the gas-liquid mixed state refrigerant into gas and liquid by gravity. The gas refrigerant is sent to the piping 602 via the piping 606 and merges with the refrigerant at the intermediate pressure. Meanwhile, the liquid refrigerant is sent to the second throttling section 67 via the piping 607. The second throttling section 67 throttles the liquid refrigerant from the gas-liquid separator 66 and sends it to the piping 608. The evaporator 24 exchanges heat between the refrigerant throttled by the second throttling section 67 and air, and sends the refrigerant after the heat exchange to the piping 609. The refrigerant sent from the evaporator 24 is returned to the low-stage compressor 61. The piping 601, 602, and 603 are an example of the first piping of the present disclosure. The pipe 604 is an example of a second pipe of the present disclosure. The pipes 605, 607, and 608 are an example of a third pipe of the present disclosure. The pipe 609 is an example of a fourth pipe of the present disclosure.

[0126] The operating state determination system 3D includes a measurement unit 4 and an operating state determination device 5D. In the first modification, the first position measurement unit 41 of the measurement unit 4 measures the temperature (chiller inlet temperature) and pressure (chiller inlet pressure) of the refrigerant at the chiller inlet P11, and transmits measurement information representing the measurement results to the operating state determination device 5D. The chiller inlet P11 is a predetermined measurement position in the pipe 609 connecting the low-stage compressor 61 and the evaporator 24. The second position measurement unit 42 measures the temperature (condenser outlet temperature) and pressure (condenser outlet pressure) of the refrigerant at the condenser outlet P12, and transmits measurement information representing the measurement results to the operating state determination device 5D. The condenser outlet P12 is a predetermined measurement position in the pipe 604 connecting the condenser 64 and the first throttling section 65.

[0127] The operating state determination device 5D may have a similar configuration to the operating state determination device 5 of the first embodiment, and may determine an excess of the refrigerant amount in the refrigeration circuit 60 by performing the same process as the operating state determination device 5. Specifically, the operating state determination device 5D may determine a high-stage compressor outlet specific enthalpy value or a condenser outlet specific enthalpy value based on the measurement results of the refrigerant temperature and pressure at the refrigerator inlet P11 and the measurement results of the refrigerant temperature and pressure at the condenser outlet P12, and may determine an excess of the refrigerant amount based on these determined specific enthalpy values. The high-stage compressor outlet specific enthalpy value is the specific enthalpy value of the refrigerant at the high-stage compressor outlet P13 in the pipe 603. The condenser outlet specific enthalpy value is the specific enthalpy value of the refrigerant at the condenser outlet P12.

[0128] The operating state determination device 5D may determine a low-stage compressor outlet specific enthalpy value (specific enthalpy value after one-stage compression) and an intercooler outlet specific enthalpy value (specific enthalpy value before two-stage compression) based on the measurement results of the refrigerant temperature and pressure at the chiller inlet P11 and the measurement results of the refrigerant temperature and pressure at the condenser outlet P12, and determine an excess amount of refrigerant based on a difference between these determined specific enthalpy values ​​(specific enthalpy difference). The low-stage compressor outlet specific enthalpy value is the specific enthalpy value of the refrigerant at the low-stage compressor outlet P14 in the piping 601. The intercooler outlet specific enthalpy value is the specific enthalpy value of the refrigerant at the intercooler outlet P15 in the piping 602.

[0129] The operating state determination device 5D may determine whether the amount of refrigerant is excessive based on at least two parameters among the high stage compressor outlet specific enthalpy value, the condenser outlet specific enthalpy value, and the specific enthalpy difference. In this case, the operating state determination device 5D may determine that the amount of refrigerant is excessive in any of the following cases. (A) When M or more parameters out of N (N=3 in this example) parameters are determined to be abnormal (B) When a specific combination of parameters is determined to be abnormal (C) When a specific parameter at a predetermined temperature is determined to be abnormal (for example, when the outside air temperature is 10°C or lower, the first parameter and the second parameter are determined to be abnormal. When the outside air temperature is above 10°C and below 25°C, the first parameter is determined to be abnormal. When the outside air temperature is above 25°C, the second parameter and the third parameter are determined to be abnormal). (D) For example, when the sum of the abnormality degrees of N parameters (a value (>0) defined based on the probability that an abnormality is actually determined when the outside temperature is T°C. The abnormality degree is 0 when the parameters are determined to be normal) is equal to or greater than a predetermined value (for example, when the outside temperature is 10°C, if the first parameter and the second parameter are abnormal and the third parameter is determined to be normal, the sum of the abnormality degree of the first parameter (>0), the abnormality degree of the second parameter (>0), and the abnormality degree of the third parameter (=0) is equal to or greater than a predetermined value).

[0130] When determining whether the amount of refrigerant is excessive using only the condenser outlet specific enthalpy value, the operational state determination device 5D does not need to measure at positions other than the condenser outlet P12. Furthermore, the operational state determination device 5D may determine whether the amount of refrigerant is insufficient based on the chiller outlet specific enthalpy value. The chiller outlet specific enthalpy value is the specific enthalpy value at the chiller outlet P16 in the pipe 607.

[0131] <Second Modification> At least one refrigeration device located away from the operating state determination device may be the target of the refrigeration device whose operating state is determined by the operating state determination system for the refrigeration system. As shown in FIG. 14, the operating state determination system 3E includes a measurement unit 4 disposed in each of the refrigeration devices 2 in the stores X, Y, and Z, and one operating state determination device 5 connected to the measurement unit 4 via a network N such as the Internet. The measurement position of the measurement unit 4 is the same as the measurement position in the first embodiment. The operating state determination device 5 is disposed in, for example, a remote monitoring room. The operating state determination device 5 determines the operating state of the refrigeration device 2 in each store based on the measurement information from each measurement unit 4, as in the first embodiment. Note that the notification unit that notifies the determination result of the operating state may be disposed in the remote monitoring room or in each store.

[0132] <Other Modifications> In the first to fourth embodiments, the abnormality of the refrigerant amount is judged based only on the compressor outlet specific enthalpy value, but the abnormality of the refrigerant amount, the abnormality of the condenser 22, liquid return, or the abnormality of the refrigeration circuit 20 as a whole may be judged based on at least one parameter among the compressor outlet specific enthalpy value, the refrigerator inlet specific enthalpy value, the condenser outlet specific enthalpy value, and the evaporator inlet specific enthalpy value. An example of the abnormality of the condenser 22 is that the heat exchange in the condenser 22 does not go well due to dirt on the condenser 22 or a condensation fan failure, and the refrigerant does not become liquid. The liquid return is a phenomenon in which the refrigerant does not evaporate well in the evaporator 24 due to frost formation, an abnormality in the throttle section 23, or the like, and the refrigerant in a liquid state or a gas-liquid mixture state is compressed by the compressor 21. When the abnormality of the refrigeration circuit 20 is judged based on a plurality of parameters, the methods (A) to (D) exemplified in the first modified example can be used.

[0133] In the first to fourth embodiments, the specific enthalpy value is used as the physical quantity used to determine the operating state of the refrigeration circuit 20, but the temperature, pressure, or specific entropy value may also be used.

[0134] In the first to fourth embodiments, the databases 54, 54A, 54C may be placed in a building or the like different from that of the operating state determination devices 5, 5A, 5B, 5C, and may be connected to the control units 55, 55A, 55B, 55C via a network.

[0135] In the first to fourth embodiments, the compressor outlet specific entropy value is estimated based on the measurement results at the refrigerator inlet P1 and the condenser outlet P2. However, the temperature and pressure of the refrigerant at the compressor outlet P3 may be measured by a measuring unit, and the compressor outlet specific entropy value may be calculated based on the measurement results.

[0136] In the first to fourth embodiments, the judgment criteria information includes a threshold value set for each outside air temperature or each predetermined temperature range, but for example, when the refrigeration device 2 is installed in a place where the outside air temperature hardly changes, one threshold value corresponding to the outside air temperature of that place may be included. There may be two or more threshold values ​​set for the outside air temperature or each predetermined temperature range, in which case the operating state of the refrigeration circuit 20 can be judged in three or more stages. [Industrial Applicability]

[0137] The present disclosure can be applied to a driving state determination device, a driving state determination system, and a driving state determination method. [Explanation of symbols]

[0138] 1,1A,1B,1C Refrigeration System 2,6 Refrigeration equipment 3,3D,3E Driving condition judgment system 4. Measurement section 5, 5A, 5B, 5C, 5D Driving condition determination device 20,60 Refrigeration circuit 21 Compressor 22,64 Condenser 23 Squeezing section 24 Evaporator 41 First position measurement unit 42 Second position measurement unit 43 Third Position Measurement Unit 51 Operation section 52 Notification Department 53,53A,53C Storage section 54, 54A, 54C Database 55, 55A, 55B, 55C Control section 61 Low stage compressor 62 Intercooler 63 High-stage compressor 65 First squeeze section 66 Gas-liquid separator 67 Second squeeze section 201,202,203,204,601,602,603,604,605,606,607,608,609 Piping 551 Acquisition Department 552 Arithmetic section 553,553A,553C Estimation part 554,554A,554B,554C Judgment section 555,555B,555C update section 556, 556A, 556B Notification control unit N Network P1,P11 Freezer inlet P2 Condenser outlet P3 Compressor outlet P4 Evaporator inlet P12 Condenser outlet P13 High stage compressor outlet P14 Low stage compressor outlet P15 Intercooler outlet P16 Freezer outlet

Claims

1. An operating state determination device for determining an operating state of a refrigeration circuit including a compressor, a condenser, a throttling section, an evaporator, a first pipe connecting the compressor and the condenser, a second pipe connecting the condenser and the throttling section, a third pipe connecting the throttling section and the evaporator, and a fourth pipe connecting the evaporator and the compressor, an estimation unit that estimates a relationship between an estimated physical quantity, which is a physical quantity of the refrigerant in at least one of the first pipe and the third pipe, and an outside air temperature, based on a measurement result of a temperature and a pressure of the refrigerant in the second pipe, a measurement result of a temperature and a pressure of the refrigerant in the fourth pipe, and a measurement result of an outside air temperature; a determination unit that selects, from a plurality of determination criteria information in which first refrigeration condition information representing a set cooling temperature and a type of refrigerant of a refrigeration circuit is associated with threshold information representing a relationship between a threshold of the estimated physical quantity and an outside air temperature, the determination criteria information associated with the first refrigeration condition information representing the set cooling temperature and the type of refrigerant of a refrigeration circuit to be determined, and determines an operating state of the refrigeration circuit to be determined based on the threshold information associated with the selected determination criteria information and the relationship between the estimated physical quantity and the outside air temperature, The physical quantity of the refrigerant is based on at least one parameter selected from the group consisting of a compressor outlet specific enthalpy value, a refrigerator inlet specific enthalpy value, a condenser outlet specific enthalpy value, and an evaporator inlet specific enthalpy value; The operating state of the refrigeration circuit to be judged is an abnormality in the amount of refrigerant, an abnormality in the condenser, a liquid return, or an abnormality in the refrigeration circuit as a whole. Driving state determination device.

2. The determination unit is determining whether or not the estimated physical quantity is equal to or greater than the threshold value at an outside air temperature corresponding to the estimated physical quantity, as an operating state of the refrigeration circuit, whether or not there is an abnormality in the amount of refrigerant in the refrigeration circuit; The driving state determination device according to claim 1 .

3. The determination unit is determining an adjustment amount of the refrigerant for adjusting the amount of the refrigerant in the refrigeration circuit to a normal amount based on a difference between the estimated physical quantity and the threshold value at an outside air temperature corresponding to the estimated physical quantity; The driving state determination device according to claim 2 .

4. The apparatus further includes a notification control unit that notifies a notification unit of a result of the determination by the determination unit. The driving state determination device according to any one of claims 1 to 3.

5. The determination unit determines at least the reliability of the determination result of the operating state and factors that reduce the reliability based on the measurement dates and times of the temperature, the pressure, and the outside air temperature. The driving state determination device according to any one of claims 1 to 4.

6. The estimation unit estimates a transition of the estimated physical quantity based on measurement results of the temperature, the pressure, and the outside air temperature at a plurality of dates and times; The determination unit determines at least the reliability of the determination result of the operating state and a factor of a decrease in the reliability based on a transition of the estimated physical quantity. The driving state determination device according to any one of claims 1 to 5.

7. The estimation unit is estimating a relationship between the estimated physical quantity and the outside air temperature at a plurality of dates and times based on measurement results of the temperature, the pressure, and the outside air temperature at the plurality of dates and times during a predetermined period; The determination unit is classifying the estimated physical quantity into a normal value or an abnormal value based on a relationship between the estimated physical quantity at each date and time and a threshold value of an outside air temperature corresponding to the estimated physical quantity; determining whether or not an abnormality exists in the refrigeration circuit over the entire predetermined period based on the relationship between the normal value and the abnormal value, as the operating state of the refrigeration circuit; The driving state determination device according to any one of claims 1 to 6.

8. A calculation unit is further provided that calculates a relationship between a calculation physical quantity, which is a physical quantity of the refrigerant in the second pipe and the fourth pipe, and an outside air temperature based on the measurement results of the temperature, the pressure, and the outside air temperature, The determination unit is from a plurality of ideal state information in which second refrigeration condition information indicative of a set cooling temperature and a type of refrigerant of a refrigeration circuit, first ideal value information indicative of a relationship between an ideal value of the calculated physical quantity and an outside air temperature, and second ideal value information indicative of a relationship between an ideal value of the estimated physical quantity and the outside air temperature are associated, the ideal state information associated with the second refrigeration condition information indicative of a set cooling temperature and a type of refrigerant of the refrigeration circuit to be determined, and at least one of the performance of the refrigeration circuit and a method for improving the performance is determined as an operating state of the refrigeration circuit based on the first ideal value information and the second ideal value information associated with the selected ideal state information, the relationship between the calculated physical quantity and the outside air temperature, and the relationship between the estimated physical quantity and the outside air temperature; The driving state determination device according to any one of claims 1 to 7.

9. A database for storing the plurality of pieces of judgment criteria information and the plurality of pieces of ideal state information, The determination unit selects the determination criterion information and the ideal state information from the plurality of determination criterion information and the plurality of ideal state information stored in the database, respectively. The driving state determination device according to claim 8.

10. A database for storing the plurality of pieces of criterion information; an update unit that updates the threshold information associated with the judgment criterion information in the database, The determination unit selects the determination criterion information from the plurality of determination criterion information stored in the database, and determines the presence or absence of an abnormality in the refrigeration circuit as an operating state of the refrigeration circuit; The update unit is recalculating the relationship between the threshold value and the outside air temperature based on the latest determination result of the presence or absence of the abnormality and previous determination results of the presence or absence of the abnormality; updating the content of the threshold information associated with the selected judgment criterion information in the database to the recalculated relationship between the threshold and the outside air temperature; The driving state determination device according to any one of claims 1 to 7.

11. The judgment criteria information further includes model information representing a model of a refrigeration device having the refrigeration circuit, The determination unit is selecting, from the plurality of pieces of judgment criterion information, the judgment criterion information associated with the first refrigeration condition information representing a set cooling temperature and a type of refrigerant of the refrigeration circuit to be judged, and the model information representing a model of a refrigeration device having the refrigeration circuit to be judged; determining whether or not the abnormality exists based on the threshold information associated with the selected determination criterion information and a relationship between the estimated physical quantity and the outside air temperature; The driving state determination device according to claim 10.

12. The determination unit is when it is determined that the reliability of the threshold information associated with the selected judgment criterion information is low, reselecting the judgment criterion information associated with the model information representing a model different from the model of the refrigeration device having the refrigeration circuit to be judged, which is associated with the first refrigeration condition information representing the set cooling temperature and the type of refrigerant of the refrigeration circuit to be judged, and which has high reliability of the threshold information; correcting a relationship between the threshold and the outside air temperature in the threshold information with high reliability based on a relationship between the threshold and the outside air temperature in the threshold information with low reliability; determining whether or not the abnormality exists based on a relationship between the corrected threshold value and the outside air temperature and a relationship between the estimated physical quantity and the outside air temperature; The update unit is recalculating the relationship between the threshold value and the outside air temperature, the relationship being determined to be unreliable, based on the latest result of the determination as to whether or not there is an abnormality and past results of the determination as to whether or not there is an abnormality; updating the content of the threshold information determined to have low reliability, associated with the selected criteria information in the database, to the recalculated relationship between the threshold and the outside air temperature; The driving state determination device according to claim 11.

13. A measurement unit; A database; The driving state determination device according to any one of claims 1 to 7, which is connected to the measurement unit and the database via a network, the measurement unit measures a temperature and pressure of the refrigerant in the second pipe, a temperature and pressure of the refrigerant in the fourth pipe, and an outside air temperature when measuring the temperatures and the pressures, and outputs measurement information representing the measurement results to the operating state determination device via the network; The database stores the plurality of pieces of criterion information; an estimation unit of the driving state determination device estimating a relationship between the estimated physical quantity and the outside air temperature based on the measurement information output from the measurement unit; The determination unit selects the determination criterion information from the plurality of determination criterion information stored in the database. Driving condition determination system.

14. A measurement unit; A database; and a driving state determination device according to claim 8, which is connected to the measurement unit and the database via a network, the measurement unit measures a temperature and pressure of the refrigerant in the second pipe, a temperature and pressure of the refrigerant in the fourth pipe, and an outside air temperature when measuring the temperatures and the pressures, and outputs measurement information representing the measurement results to the operating state determination device via the network; the database stores the plurality of pieces of judgment criteria information and the plurality of pieces of ideal state information; an estimation unit of the driving state determination device estimating a relationship between the estimated physical quantity and the outside air temperature based on the measurement information output from the measurement unit; The determination unit selects the determination criterion information and the ideal state information from the plurality of determination criterion information and the plurality of ideal state information stored in the database, respectively. Driving condition determination system.

15. A measurement unit; The driving state determination device according to any one of claims 9 to 12, which is connected to the measurement unit via a network, the measurement unit measures a temperature and pressure of the refrigerant in the second pipe, a temperature and pressure of the refrigerant in the fourth pipe, and an outside air temperature when measuring the temperatures and the pressures, and outputs measurement information representing the measurement results to the operating state determination device via the network; The estimation unit of the driving state determination device estimates a relationship between the estimated physical quantity and the outside air temperature based on the measurement information output from the measurement unit. Driving condition determination system.

16. An operation determination method performed by an operation state determination device that determines an operation state of a refrigeration circuit including a compressor, a condenser, a throttling section, an evaporator, a first pipe connecting the compressor and the condenser, a second pipe connecting the condenser and the throttling section, a third pipe connecting the throttling section and the evaporator, and a fourth pipe connecting the evaporator and the compressor, The driving state determination device includes: Based on the measurement results of the temperature and pressure of the refrigerant in the second pipe, the measurement results of the temperature and pressure of the refrigerant in the fourth pipe, and the measurement result of the outside air temperature, an estimated physical quantity, which is a physical quantity of the refrigerant in at least one of the first pipe and the third pipe, is estimated as a relationship between the outside air temperature and the estimated physical quantity; selecting, from among a plurality of pieces of judgment criterion information in which first refrigeration condition information representing a set cooling temperature and a type of refrigerant of a refrigeration circuit is associated with threshold information representing a relationship between a threshold of the estimated physical quantity and an outside air temperature, the judgment criterion information associated with the first refrigeration condition information representing the set cooling temperature and the type of refrigerant of a refrigeration circuit to be judged, and judging an operating state of the refrigeration circuit to be judged based on the threshold information associated with the selected judgment criterion information and the relationship between the estimated physical quantity and the outside air temperature; The physical quantity of the refrigerant is based on at least one parameter selected from the group consisting of a compressor outlet specific enthalpy value, a refrigerator inlet specific enthalpy value, a condenser outlet specific enthalpy value, and an evaporator inlet specific enthalpy value; The operating state of the refrigeration circuit to be judged is an abnormality in the amount of refrigerant, an abnormality in the condenser, a liquid return, or an abnormality in the refrigeration circuit as a whole. A method for determining a driving state.

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