JP2018204831A - Refrigerator - Google Patents

Abstract

To provide a refrigerator capable of early and accurately determining sign of refrigeration leakage from a refrigeration circuit, and then reporting the sign.SOLUTION: A reference discharge temperature calculation unit 71 is configured to continuously calculate a discharge temperature average value based on a discharge temperature Td at a reference rotational frequency RNc of a compressor, and set a minimum discharge temperature average value as a reference discharge temperature RTd, and similarly a reference suction temperature calculation unit 72 is configured to set a minimum suction temperature average value as a reference suction temperature RTs. A refrigerant leakage determination unit 73 is configured to determine the fact that the discharge temperature Td rises by a threshold or more with respect to the reference discharge temperature RTd, and a suction temperature Ts rises by a threshold or more with respect to the reference suction temperature RTs, as sign of refrigerant leakage.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a refrigeration apparatus that circulates refrigerant in a refrigerant circuit by a compressor, and more particularly, to a refrigeration apparatus that includes a control device that determines and reports refrigerant leakage from the refrigerant circuit.

  Traditionally, multiple showcases (kitchens) have been installed in stores (convenience stores) such as convenience stores, foods such as sandwiches, rice balls, lunch boxes, noodles, prepared dishes, desserts, and beverages such as water, tea, and juice ( Refrigerated products), ice, frozen foods, etc. (frozen products) are being sold while being cooled. In this case, the evaporator of each showcase (referred to as a separate-type showcase) installed near the wall constitutes a refrigerant circuit of the refrigeration apparatus together with the compressor of the refrigerator installed outside the store, and the compressor Therefore, the refrigerant is distributed and supplied to the evaporator of each showcase. For example, in the case of a showcase that sells ice for freezing, convenience stores are often installed in an island shape in a passage away from the wall. In this case, the showcase is a refrigeration system including a compressor and an evaporator. A so-called built-in showcase with a built-in refrigerant circuit was used.

  Here, when the refrigerant leaks from the refrigerant circuit of these refrigeration apparatuses, the required refrigeration capacity cannot be exhibited. In particular, when supplying refrigerant from a compressor of a refrigerator installed outside the store to the evaporator of a showcase in the store, the refrigerator and showcase are connected by a relatively long refrigerant pipe. The refrigerant leaks easily. Therefore, conventionally, a detection device such as an impeller or a leakage sensor for detecting refrigerant leakage from the refrigeration apparatus has been provided (for example, see Patent Document 1).

JP 2006-114333 A

  However, when detecting a refrigerant leak from the refrigerant circuit with a conventional detection device, it is easy to detect a sudden refrigerant leak, but it is difficult to detect when gradually leaking gradually (so-called slow leak). For example, it is not possible to detect refrigerant leakage in winter when the refrigeration load of the showcase is light, and when the refrigeration load increases in summer, the refrigeration capacity is insufficient, and the display room will not cool down, causing deterioration of the product There was a problem. In order to solve this problem, it is necessary to make the sensitivity of the detection device sensitive. However, in this case, there is a drawback that erroneous detection is likely to occur.

  The present invention has been made to solve the conventional technical problems, and provides a refrigeration apparatus capable of determining and notifying a sign of refrigerant leakage from a refrigerant circuit early and accurately. For the purpose.

  In order to solve the above-described problems, a refrigeration apparatus of the present invention includes a control device that circulates refrigerant in a refrigerant circuit by a compressor and controls the rotation speed of the compressor. A discharge temperature sensor for detecting the discharge refrigerant temperature of the compressor, an intake temperature sensor for detecting the intake refrigerant temperature of the compressor, a reference discharge temperature calculation unit for calculating the reference discharge temperature RTd, and a reference suction for calculating the reference intake temperature RTs A temperature calculation unit, a refrigerant leakage determination unit that determines refrigerant leakage from the refrigerant circuit, and a notification unit are provided. The reference discharge temperature calculation unit sets the predetermined rotation speed of the compressor as the reference rotation speed RNc, and the reference rotation speed The discharge temperature average value is continuously calculated by averaging the discharge temperature Td determined based on the value detected by the discharge temperature sensor in the RNc for a predetermined period, and the latest discharge temperature than the previous discharge temperature average value is calculated. When the average value decreases, the latest discharge temperature average value is updated as the reference discharge temperature RTd, and the reference suction temperature calculation unit determines the suction temperature determined based on the value detected by the suction temperature sensor at the reference rotation speed RNc. By averaging Ts for a predetermined period, the average suction temperature value is calculated continuously. If the latest suction temperature average value is lower than the previous suction temperature average value, the latest suction temperature average value is used as the reference suction temperature. The refrigerant leakage determination unit compares the discharge temperature Td with the reference discharge temperature RTd and the suction temperature Ts with the reference suction temperature RTs, and the discharge temperature Td increases with respect to the reference discharge temperature RTd. The degree of change is equal to or higher than the predetermined discharge temperature threshold STd, the suction temperature Ts is increased with respect to the reference suction temperature RTs, and the degree of change is equal to or higher than the predetermined suction temperature threshold STs. Based on bets, as well as determined that there is a sign of refrigerant leakage from the refrigerant circuit, the notification unit, when the refrigerant leakage determination unit determines that there sign of refrigerant leakage, and executes a predetermined notification operation.

  In the refrigeration apparatus according to the second aspect of the present invention, the degree of change of the discharge temperature Td with respect to the reference discharge temperature RTd is the difference between the discharge temperature Td and the reference discharge temperature RTd (Td−RTd) or the discharge temperature Td and the reference. It is a ratio (Td / RTd) to the discharge temperature RTd, and the degree of change of the suction temperature Ts with respect to the reference suction temperature RTs is the difference between the suction temperature Ts and the reference suction temperature RTs (Ts−RTs) or the suction temperature Ts. It is a ratio (Ts / RTs) to the reference suction temperature RTs.

  In the refrigeration apparatus according to a third aspect of the present invention, in each of the above inventions, the reference discharge temperature calculation unit calculates a discharge temperature average value by moving and averaging the discharge temperature Td for the predetermined period, and the reference suction temperature calculation unit An average suction temperature value is calculated by moving and averaging the temperature Ts for the predetermined period.

  In the refrigeration apparatus according to a fourth aspect of the present invention, in each of the above inventions, the reference discharge temperature calculation unit determines, as the discharge temperature Td, a value obtained by averaging a value detected by the discharge temperature sensor at the reference rotation speed RNc for a period shorter than the predetermined period. The reference suction temperature calculation unit determines an average value of a value detected by the suction temperature sensor at a reference rotation speed RNc for a period shorter than the predetermined period as the suction temperature Ts.

  In the refrigeration apparatus according to a fifth aspect of the present invention, in each of the inventions described above, the refrigerant leakage determination unit determines that the degree of change in the discharge temperature Td with respect to the reference discharge temperature RTd is equal to or higher than the discharge temperature threshold STd and the suction temperature Ts with respect to the reference suction temperature RTs. When the state in which the degree of change is equal to or higher than the suction temperature threshold value STs continues for a certain period or longer, it is determined that there is a sign of refrigerant leakage from the refrigerant circuit.

  According to a sixth aspect of the present invention, in the above refrigeration apparatus, the control device includes an outside air temperature sensor that detects the outside air temperature, and the reference discharge temperature calculation unit determines the discharge temperature Td for each outside air temperature, and the reference discharge temperature. RTd is calculated, the reference intake temperature calculation unit determines the intake temperature Ts for each outside air temperature, calculates the reference intake temperature RTs, and the refrigerant leakage determination unit calculates the discharge temperature Td and the reference discharge temperature RTd for each outside air temperature. And comparing the suction temperature Ts with the reference suction temperature RTs to determine whether or not there is a sign of refrigerant leakage from the refrigerant circuit.

  In the refrigeration apparatus according to a seventh aspect of the present invention, in each of the above-described inventions, the control device includes an outside air temperature sensor that detects the outside air temperature, and the refrigerant leakage determination unit sets the suction temperature threshold STs in a direction to increase as the outside air temperature increases. The discharge temperature threshold value STd is changed in such a direction that it is changed and / or is lowered as the outside air temperature is higher.

  The refrigeration apparatus according to an eighth aspect of the invention is characterized in that, in each of the above inventions, the notification unit changes the corresponding urgency level according to the time when the refrigerant leakage determination unit determines that there is a sign of refrigerant leakage. .

  According to a ninth aspect of the present invention, there is provided a refrigeration apparatus comprising a plurality of showcases each provided with an evaporator and a refrigerator provided with a compressor in each of the above inventions, and distributing refrigerant from the compressor to each evaporator by means of refrigerant piping. In addition to supplying, the control device centrally controls the operation of each showcase and the refrigerator.

  FIG. 13 shows the result of measuring the discharge temperature (discharge refrigerant temperature) of the compressor of an example refrigeration apparatus that cools the showcase, and FIG. 14 shows the result of measuring the intake temperature (intake refrigerant temperature) of the compressor. ing. In each figure, L1 indicates the temperature when a full amount of refrigerant is filled in the refrigerant circuit for each outside air temperature, and L2 indicates the temperature when the filling amount is reduced to, for example, 50% of the full amount. It shows for every temperature, L3 has shown those differences (L2-L1).

  Note that the temperature of the compressor is measured at the maximum control frequency (for example, 80 Hz). Moreover, in the example of each figure, outside temperature is low temperature (for example, temperature range below 10 degreeC), medium temperature (for example, temperature range higher than 10 degreeC and below 20 degreeC), and high temperature (for example, temperature range higher than 20 degreeC), respectively. The discharge temperature and the suction temperature when the outside air temperature is 10 ° C., 20 ° C., and 30 ° C. included in each temperature zone are shown. Furthermore, a line graph is shown on the upper side of each figure, and a numerical value is shown on the lower side.

  When the refrigerant leaks from the refrigerant circuit of the refrigeration apparatus, the refrigerant sucked into the compressor becomes dry, so that the intake temperature (intake refrigerant temperature) of the compressor rises. In the case of the example of FIG. 14, when the outside air temperature is low (10 ° C.), the suction temperature when the refrigerant is full is 1.0 ° C., but when it is 50%, the suction temperature rises to 6.0 ° C. The temperature difference between them was 5.0 ° C. In addition, the suction temperature when the refrigerant was full when the outside air temperature was medium temperature (20 ° C) was 2.0 ° C, but when it was 50%, it rose to 9.0 ° C, and the temperature difference between them was The temperature reached 7.0 ° C. Furthermore, when the outside air temperature is high (30 ° C.), the suction temperature when the refrigerant is full was 3.0 ° C., but when it is 50%, it rises to 12.0 ° C., and the temperature difference between them is It became 9.0 degreeC.

  Further, when the refrigerant leaks from the refrigerant circuit of the refrigeration apparatus and the suction temperature rises, the discharge temperature (discharge refrigerant temperature) of the compressor also rises. In the case of the example in FIG. 13, the discharge temperature when the refrigerant is full when the outside air temperature is low (10 ° C.) was 50.0 ° C., but when it is 50%, it rises to 60.0 ° C. The temperature difference between them was 10.0 ° C. Also, the discharge temperature when the refrigerant was full when the outside air temperature was medium temperature (20 ° C.) was 63.0 ° C., but when it was 50%, it increased to 70.0 ° C., and the temperature difference between them was The temperature reached 7.0 ° C. Furthermore, the discharge temperature when the refrigerant was full when the outside air temperature was high (30 ° C.) was 75.0 ° C., but when it was 50%, it increased to 80.0 ° C., and the temperature difference between them was It became 5.0 degreeC. It has been experimentally confirmed that even if the refrigerant is reduced to 50%, the change in the discharge pressure and the suction pressure of the refrigerant circuit is small.

  Therefore, as in the present invention, the reference discharge temperature calculation unit of the control device sets the predetermined rotation speed of the compressor as the reference rotation speed RNc, and the discharge determined based on the value detected by the discharge temperature sensor at the reference rotation speed RNc. The discharge temperature average value is continuously calculated by averaging the temperature Td for a predetermined period. When the latest discharge temperature average value is lower than the previous discharge temperature average value, the latest discharge temperature average value is used as the reference discharge. The temperature is updated as the temperature RTd, and the reference intake temperature calculation unit continuously calculates the intake temperature average value by averaging the intake temperature Ts determined based on the value detected by the intake temperature sensor at the reference rotation speed RNc for a predetermined period. When the latest suction temperature average value is lower than the previous suction temperature average value, the latest suction temperature average value is updated as the reference suction temperature RTs, and the refrigerant leakage determination unit Td is compared with the reference discharge temperature RTd, and the suction temperature Ts is compared with the reference suction temperature RTs. The discharge temperature Td rises with respect to the reference discharge temperature RTd, and the degree of change is equal to or higher than a predetermined discharge temperature threshold STd. Since the suction temperature Ts rises with respect to the reference suction temperature RTs and the degree of change thereof is equal to or higher than the predetermined suction temperature threshold STs, it is determined that there is a sign of refrigerant leakage from the refrigerant circuit. Even when the refrigerant is gradually leaking from the refrigerant circuit, it is possible to determine the sign of refrigerant leakage at an early stage and notify the notification by the notification unit.

  In particular, the reference discharge temperature RTd calculated by the reference discharge temperature calculation unit and the reference suction temperature RTs calculated by the reference suction temperature calculation unit are for a predetermined period of the discharge temperature Td and the suction temperature Ts at the reference rotation speed RNc of the compressor. Since it is an average value and is a value updated when the latest average value is lower than the previous average value calculated continuously, the refrigerant leakage determination unit accurately determines a sign of refrigerant leakage. Will be able to.

  In this case, as the degree of change of the discharge temperature Td with respect to the reference discharge temperature RTd, for example, the difference (Td−RTd) between the discharge temperature Td and the reference discharge temperature RTd as in the invention of claim 2 or the discharge temperature Td and the reference discharge temperature. A ratio (Td / RTd) to the temperature RTd can be adopted, and the degree of change of the suction temperature Ts with respect to the reference suction temperature RTs is the difference (Ts−RTs) between the suction temperature Ts and the reference suction temperature RTs, or the suction temperature Ts. The ratio (Ts / RTs) between the reference suction temperature RTs and the reference suction temperature RTs can be employed.

  According to a third aspect of the present invention, the reference discharge temperature calculation unit calculates a discharge temperature average value by moving and averaging the discharge temperature Td for the predetermined period, and the reference suction temperature calculation unit calculates the suction temperature Ts. By calculating the suction temperature average value by performing the moving average for the period, it is possible to more quickly determine the sign of refrigerant leakage from the refrigerant circuit.

  According to a fourth aspect of the present invention, the reference discharge temperature calculation unit determines, as the discharge temperature Td, a value obtained by averaging the value detected by the discharge temperature sensor at the reference rotation speed RNc for a period shorter than the predetermined period. The calculation unit determines, as the suction temperature Ts, a value obtained by averaging the value detected by the suction temperature sensor at the reference rotational speed RNc for a period shorter than the predetermined period, thereby eliminating the influence of disturbance and providing a more accurate refrigerant. It becomes possible to perform a leakage sign determination.

  Further, according to the invention as set forth in claim 5, the refrigerant leakage determination unit has a change degree of the discharge temperature Td with respect to the reference discharge temperature RTd equal to or higher than the discharge temperature threshold STd, and a change degree of the intake temperature Ts with respect to the reference intake temperature RTs is the intake temperature. If the state where the threshold value STs or more has continued for a certain period or longer, it is possible to eliminate the influence of disturbance and to perform more accurate refrigerant leak sign determination by determining that there is a sign of refrigerant leak from the refrigerant circuit. become able to.

  Here, as shown in FIGS. 13 and 14 described above, the discharge temperature Td and the suction temperature Ts vary depending on the outside air temperature. Therefore, the control device as in the invention of claim 6 includes an outside air temperature sensor that detects the outside air temperature, and the reference discharge temperature calculation unit determines the discharge temperature Td for each outside air temperature, calculates the reference discharge temperature RTd, The reference intake temperature calculation unit determines the intake temperature Ts for each outside air temperature, calculates the reference intake temperature RTs, and the refrigerant leakage determination unit calculates the discharge temperature Td, the reference discharge temperature RTd, and the intake temperature for each outside air temperature. By comparing Ts and the reference suction temperature RTs to determine whether or not there is a sign of refrigerant leakage from the refrigerant circuit, the influence of the outside air temperature is eliminated and accurate refrigerant leakage sign determination is performed. Will be able to.

  Further, as shown in FIGS. 13 and 14, the temperature difference between the discharge temperature Td and the suction temperature Ts when the refrigerant in the refrigerant circuit is full and when it leaks also varies depending on the outside air temperature. The temperature difference between the discharge temperatures Td was the same in the low temperature and medium temperature ranges, but decreased in the high temperature range. In contrast, the temperature difference of the suction temperature Ts is widened to increase the temperature range. Therefore, the refrigerant leakage determination unit of the control device as in the seventh aspect of the invention changes the intake temperature threshold value STs in a direction to increase the higher the outside air temperature and / or decreases the higher the outside air temperature. By changing the discharge temperature threshold value STd, it becomes possible to perform a quick and accurate refrigerant leak sign determination.

  Further, if the notification unit changes the corresponding urgency level according to the timing when the refrigerant leakage determination unit determines that there is a sign of refrigerant leakage as in the invention of claim 8, for example, the refrigeration load is compared. As a result of requesting a quick response unnecessarily, for example, a notification that allows a response with sufficient margin in winter when the refrigeration load is low, and a notification that requests a quick response in summer when the refrigeration load is large Can be avoided in advance.

  The present invention includes a plurality of showcases equipped with an evaporator as in the invention of claim 9 and a refrigerator equipped with a compressor, and distributes and supplies the refrigerant from the compressor to each evaporator through a refrigerant pipe. The control device is extremely effective for predicting and notifying the leakage of refrigerant in the refrigeration apparatus that centrally controls the operation of each showcase and refrigerator.

It is a figure explaining the communication line of the centralized management apparatus containing the freezing apparatus of one Example to which this invention is applied, and the piping structure of a freezing apparatus (Example 1). It is a functional block diagram of the connection case controller of FIG. It is a functional block diagram of the refrigerator controller of FIG. It is a functional block diagram of the main controller of FIG. It is a functional block diagram of the non-connection case controller of FIG. It is a functional block diagram of the tablet terminal of FIG. It is a flowchart explaining the refrigerant | coolant leak sign determination which the main controller of FIG. 4 performs. FIG. 5 is a view showing a detection data table for explaining refrigerant leak prediction determination control similarly executed by the main controller of FIG. 4. FIG. 6 is also a diagram for explaining the totaling / calculation of the discharge temperature average value and the update process of the reference discharge temperature RTd executed by the main controller of FIG. 4. It is a front view which shows the alerting | reporting screen of the tablet terminal of FIG. It is a front view which shows another alerting | reporting screen of the tablet terminal of FIG. (Example 2) which is a figure explaining the communication line of the centralized management apparatus of another Example containing the freezing apparatus to which this invention is applied, and the piping structure of a freezing apparatus. It is a figure which shows the change of the discharge temperature of a compressor when a refrigerant | coolant circuit is filled with the full quantity of refrigerant | coolant, and when a refrigerant | coolant leaks. It is a figure which shows the change of the suction temperature of a compressor when a refrigerant | coolant circuit is filled with the full quantity refrigerant | coolant, and when a refrigerant | coolant leaks.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a communication line of a centralized management apparatus 1 including a refrigeration apparatus R according to an embodiment to which the present invention is applied and a piping configuration of the refrigeration apparatus R.
(1) Refrigeration equipment R
In FIG. 1, the refrigeration apparatus R according to the embodiment includes a plurality of showcases (equipment) 2 installed on the inner wall of a store such as a convenience store, a compressor 3 and the like, and is installed outside the store. It is comprised from the machine 4 (apparatus). Each showcase 2 includes an evaporator 6, an expansion valve (electronic expansion valve) 7, a cool air circulation blower (not shown), and the like, and the refrigerator 4 includes a compressor 3 and a condenser blower (not shown) in addition to the compressor 3. Etc. are provided. In addition, although shown with the single compressor 3 in an Example, you may comprise the compressor 3 of the refrigerator 4 of FIG. 1 with several compressors.

  The condenser described above is connected to the discharge side of the compressor 3 of the refrigerator 4, and a high-pressure pipe (refrigerant pipe) 8 is connected to the condenser. Each showcase 2 is a so-called separate showcase, and the inlet of the evaporator 6 of each showcase 2 is connected in parallel to a high-pressure pipe (refrigerant pipe) 8 via an expansion valve 7, and the outlet of the evaporator 6. Is connected to the suction side of the compressor 3 through a low-pressure pipe (refrigerant pipe) 9. The high-pressure pipe 8 and the low-pressure pipe 9 are arranged from the refrigerator 4 installed outside the store to each showcase 2 installed in the store, and thereby, a refrigerant circuit RC of the refrigeration apparatus R is configured. ing.

  Then, the high-temperature and high-pressure refrigerant (for example, R404a) discharged from the compressor 3 is air-cooled by a condenser, and then exits from the refrigerator 4 and enters the high-pressure pipe 8. Each showcase passes through the high-pressure pipe 8. 2 is distributed and supplied. The refrigerant distributed and supplied from the common compressor 3 to each showcase 2 is throttled by each expansion valve 7 and then flows into the evaporator 6 to evaporate. The interior of each showcase 2 is cooled by cooling the air circulated by the cool air circulation blower by the endothermic action at this time and circulating the cooled cool air into the interior. The refrigerant evaporated in the evaporator 6 then enters the refrigerator 4 through the low-pressure pipe 9 and repeats circulation sucked into the compressor 3.

(2) Connection case controller 12
Each showcase 2 constituting the refrigeration apparatus R is provided with a connection case controller 12 (equipment controller, which constitutes a part of the control device in the present invention) composed of a microcomputer as an example of a computer having a processor. It has been. FIG. 2 shows a functional block diagram of the connection case controller 12. The connection case controller 12 includes a control unit 21 that controls operation of the expansion valve 7 and the cool air circulation blower of the showcase 2 and communication control with the main controller 11 described later, and a storage unit that stores various types of information (data). 22, a signal input unit 23 to which a temperature sensor 25 or the like for detecting the internal temperature or the like is connected, a display unit 24 for displaying various data or the like, an input unit 26 for switching settings, and the like, And a communication unit 28 that transmits and receives information (data) via a main controller 11 described later and a communication line 14 described later.

  The control unit 21 of each connection case controller 12 receives instruction information (driving instruction data) transmitted from the main controller 11 described later to each showcase 2 via the communication unit 28, and receives the received instruction information (setting) Temperature) and the output of the temperature sensor 25 that detects its own internal temperature, the device drive unit 27 controls the valve opening of the expansion valve 7 and the operation of the cool air circulation blower.

  In this case, the showcase 2 is a fixture that sells and sells products such as lunch boxes, noodles, prepared dishes, desserts, ice cream, etc., and the controller 21 of the connection case controller 12 of the showcase 2 has an average internal temperature. Then, the opening degree of the expansion valve 7 is controlled by the device drive unit 27 between the fully closed state and the control upper limit opening degree so as to be each set temperature (instruction information), and the operation of the cooling air circulation fan is controlled.

(3) Refrigerator controller 13
In addition, the refrigerator 4 is also provided with a refrigerator controller 13 (equipment controller, which constitutes a part of the control device in the present invention) composed of a microcomputer that is an example of a computer including a processor. The configuration of the refrigerator controller 13 is basically the same as that shown in FIG. 2, but the signal input unit 23 includes a discharge temperature sensor 30 that detects the discharge refrigerant temperature PTd of the compressor 3 and an intake refrigerant temperature PTs of the compressor 3. A suction temperature sensor 35, a pressure sensor 40, and the like that detect the above are connected, and the device driven by the device driving unit 27 is the compressor 3 or the like. And the control part 21 of this refrigerator controller 13 receives the instruction information (operation instruction data) addressed to the refrigerator controller 13 from the main controller 11, which will be described later, via the communication part 28, and this instruction information (low pressure setting value). ) And the output of the pressure sensor 40 for detecting the low pressure of the refrigerant circuit RC extending from the low pressure pipe 9 to the suction side of the compressor 3, the rotation speed (operation frequency Hz) of the compressor 3 is controlled by the device drive unit 27. To do.

  In this case, the control unit 21 of the refrigerator controller 13 sets the low pressure to the low pressure based on the low pressure setting value (instruction information) transmitted from the main controller 11 and the low pressure (measured value) detected by the pressure sensor 40. When the pressure is higher than the value, the rotation speed (operating frequency Hz) of the compressor 3 is increased by the device driving unit 27, and when it is lower, the operation of the compressor 3 is controlled so as to decrease. When the expansion valve 7 of all the showcases 2 is fully closed, the compressor 3 is stopped by the device driving unit 27.

  Further, the discharge refrigerant temperature PTd and the intake refrigerant temperature PTs detected by the discharge temperature sensor 30 and the suction temperature sensor 35 of the refrigerator controller 13 and the rotation speed (Hz) of the compressor 3 are controlled by the control unit 21 and the communication unit 28. It is configured to be transmitted to the main controller 11 via the communication line 14.

(4) Main controller 11
The main controller 11 is a centralized control device called a store master installed in a management room of a store (this also constitutes a part of the control device in the present invention), and is an example of a computer having a processor. Consists of a microcomputer. FIG. 4 shows a functional block diagram of the main controller 11. The main controller 11 is connected to a control unit 31 that controls each device and communication control, a storage unit 32 that stores various information (data), and an outside temperature sensor 45 that detects outside temperature (outside store temperature). A signal input unit 33, a display unit 34 composed of a color liquid crystal display or the like for displaying various data, an input unit 36 composed of a key switch, an output unit 37 composed of a buzzer, etc. Wirelessly to a modem 38 that performs transmission / reception, a communication unit 39 that transmits / receives information (data) to / from the connection case controller 12 and the refrigerator controller 13 described above, and a tablet terminal (portable terminal device) 41 that will be described later. The wireless communication unit 42 wirelessly communicates data via a LAN.

  The communication unit 39 of the main controller 11 is connected to the communication unit 28 of each connection case controller 12 and the communication unit 28 of the refrigerator controller 13 via the communication line 14, and the main controller 11 and each communication unit 28 are connected via the communication line 14. Information (data) is transmitted and received between the connection case controller 12 and between the main controller 11 and the refrigerator controller 13. The main controller 11, each connection case controller 12, and the refrigerator controller 13 construct a centralized management system for stores connected by the communication line 14, and each controller 11, 12, 13 and a tablet terminal 41 (to be described later) The control apparatus of the freezing apparatus R in this Example is comprised.

  In this case, the control unit 31 of the main controller 11 identifies each of the connection case controller 12 and the refrigerator controller 13 using an ID assigned in advance to each connection case controller 12 and the refrigerator controller 13. And the data regarding the driving | operation information transmitted with each ID from each connection case controller 12 and the refrigerator controller 13 is received, and they are stored in the memory | storage part 32, and are managed. The operation information transmitted from each connection case controller 12 includes information on the internal temperature of the showcase 2, information on the status of the defrosting operation of the evaporator 6, and errors (abnormalities) occurring in the showcase 2. The operation information that includes the alarm information and is transmitted from the refrigerator 4 includes the operation state (the value of the rotation speed) of the compressor 3, the value of the low pressure, and the values of the discharge refrigerant temperature PTd and the intake refrigerant temperature PTs described above. Alarm information regarding an error (abnormality) occurring in the refrigerator 4 is included.

  Further, the main controller 11 transmits data related to the instruction information together with the ID described above to each connection case controller 12 and the refrigerator controller 13. The instruction information includes the set temperature described above when addressing to the showcase 2 and the low-pressure pressure set value described above when addressing to the refrigerator 4. The control unit 21 of each connection case controller 12 or refrigerator controller 13 stores the received data in the storage unit 22 and controls the operation of each device. Thus, the main controller 11 centrally manages the operations of the showcases 2 and the refrigerators 4 constituting the refrigeration apparatus R.

  In addition, the control unit 31 of the main controller 11 includes a reference discharge temperature calculation unit 71, a reference suction temperature calculation unit 72, a refrigerant leakage determination unit 73, and a notification unit 74 as its functions (FIG. 4). These functions will be described in detail later.

(5) Unconnected showcase 2
Next, an unconnected showcase 2 that is not connected to the refrigeration apparatus R in FIG. 1 is, for example, a frozen showcase (ice case) that displays and sells ice cream while cooling it. is set up. The showcase 2 is a so-called built-in showcase, and includes a known refrigerant circuit including a compressor 43, a decompressor 44 such as a condenser and a capillary tube (not shown), and an evaporator 46. The refrigerant discharged from the compressor 43 is squeezed by the decompression device 44 and then flows into the evaporator 46 and evaporates. The inside of the showcase 2 is cooled by cooling the air circulated by a cool air circulation blower (not shown) by the endothermic action at this time and circulating the cooled cold air inside the cabinet. The refrigerant evaporated in the evaporator 46 repeats circulation that is sucked into the compressor 43.

(6) Unconnected case controller 47
This non-connected showcase 2 is also provided with a non-connected case controller 47 (device controller) composed of a microcomputer as an example of a computer provided with a processor. However, the unconnected case controller 47 is not connected to the main controller 11 via the communication line 14.

  FIG. 5 shows a functional block diagram of the non-connection case controller 47. The non-connection case controller 47 includes a control unit 48 that controls operation of the compressor 43 and the cool air circulation blower of the non-connection showcase 2 and communication control with a tablet terminal (portable terminal device) 41 to be described later. A storage unit 49 for storing various information (data), an internal temperature sensor 50 for detecting the internal temperature, a discharge temperature sensor 30 for detecting the discharge refrigerant temperature of the compressor 43 as described above, and an intake refrigerant of the compressor 43 as well. A signal input unit 51 to which an intake temperature sensor 35 that detects temperature is connected, a display unit 52 that displays various data, an input unit 53 that performs setting switching, and the like, and a device drive unit 54 that drives each of the above devices A wireless communication unit 56 that performs wireless communication of information (data) with a tablet terminal 41 (to be described later) via a wireless LAN.

  The control unit 48 of the non-connection case controller 47 receives instruction information (driving instruction data) transmitted from the tablet terminal 41 described later to the showcase 2 via the wireless communication unit 56, and receives the received instruction information ( Based on the output of the internal temperature sensor 50 that detects the set temperature) and the internal temperature of the internal compartment, the device drive unit 54 controls the operation of the compressor 43 and the cool air circulation blower, and the forced defrost instruction information is included in the instruction information. Is included, the defrosting of the evaporator 46 is forcibly executed.

(7) Tablet terminal 41 (mobile terminal device)
Next, reference numeral 41 shown in FIG. 1 denotes the tablet terminal described above. The tablet terminal 41 is a portable terminal device (portable terminal device), and includes a display unit 61 composed of a relatively large liquid crystal display as shown in FIG. 10 and an input unit 62 composed of a touch switch provided in the display unit 61. It is possible to input and output information (FIG. 6).

  FIG. 6 shows a functional block diagram of the tablet terminal 41. The tablet terminal 41 is also composed of a microcomputer that is an example of a computer including a processor, and controls a control unit 63 that controls various types of control including communication, a storage unit 64 that stores various types of information (data) including maintenance information described below, The display unit 61 and the input unit 62 are configured by a wireless communication unit 66 that transmits and receives data by wireless communication via the wireless LAN between the main controller 11 and the non-connection case controller 47 described above.

  Here, in FIG. 1, 76 is a POS terminal provided in a store and performs inventory management and sales management of the store, and 77 is maintenance management of equipment such as the showcase 2 and the refrigerator 4 provided in the store. It is an external maintenance center that is contracted to perform. In FIG. 1, reference numeral 67 denotes a wireless LAN router that establishes a wireless LAN in the store. The wireless LAN router 67 is connected to the Internet line via a broadband modem 68.

  The tablet terminal 41 and the main controller 11, the tablet terminal terminal 41 and the unconnected case controller 47, and the tablet terminal 41 and the POS terminal 76 transmit and receive information (data) via the wireless LAN router 67 in the embodiment. (Alternatively, it may be possible to directly transmit and receive data without using such a wireless LAN router). The tablet terminal 41 transmits and receives information (data) to and from the external maintenance center 77 via the wireless LAN router 67 and the Internet line.

  Also in this case, the control unit 63 of the tablet terminal 41 identifies the unconnected case controller 47 and the main controller 11 using IDs assigned in advance to the unconnected case controller 47 and the main controller 11. And the tablet terminal 41 receives the data regarding the driving | operation information transmitted with ID from the main controller 11 by the wireless communication part 66, and stores and manages it in the memory | storage part 64. FIG. The operation information sent from the main controller 11 includes operation information (including alarm information) of each showcase 2 and refrigerator 4 managed by the main controller 11, such as temperature / humidity inside and outside the store. Information: main controller information).

  In addition, the tablet terminal 41 receives the data related to the driving information transmitted together with the ID from the non-connection case controller 47 by the wireless communication unit 66 and stores the data in the storage unit 64 for management. The operation information sent from the non-connected case controller 47 includes the internal temperature of the non-connected showcase 2, information on the defrosting operation status of the evaporator 46, and errors occurring in the showcase 2 ( Alarm information etc. regarding (abnormality) is included.

  On the other hand, instruction information (driving instruction data) is transmitted from the tablet terminal 41 to the main controller 11 and the unconnected showcase 2 by the wireless communication unit 66. Since the collected information can be displayed on the display unit 61 as appropriate in the tablet terminal 41, in addition to the unconnected showcase 2 in the tablet terminal 41, the showcase 2 and the refrigerator 4 that the main controller 11 centrally manages. It is configured so that the driving situation can be centrally managed.

(8) Refrigerant leakage sign determination control from refrigerant circuit RC of refrigeration apparatus R by main controller 11 Next, a refrigerant leakage sign from refrigerant circuit RC of refrigeration apparatus R using FIGS. 7 to 11, 13, and 14. The determination control will be described. As described above, since the refrigerator 4 and each showcase 2 constituting the refrigerant circuit RC of the refrigeration apparatus R are connected by the high-pressure pipe 8 and the low-pressure pipe 9 extending from the outside of the store to the inside of the store, the refrigerant circuit RC is used over time. Then, the refrigerant leaks from the connection points. When the refrigerant leaks from the refrigerant circuit RC, the discharge refrigerant temperature PTd and the suction refrigerant temperature PTs of the compressor 3 rise as described above.

  Therefore, in this embodiment, the main controller 11 determines once in a day whether or not there is a sign of refrigerant leakage in the refrigerant circuit RC of the refrigeration apparatus R. FIG. 7 shows a flowchart of an embodiment of refrigerant leakage sign determination control by the main controller 11. The control unit 31 of the main controller 11 receives the discharge refrigerant temperature PTd and the intake refrigerant temperature PTs (detected by the discharge temperature sensor 30 and the intake temperature sensor 35) sent from the refrigerator controller 13 at a predetermined sampling period ( For example, every 10 minutes).

  In that case, the control unit 31 simultaneously sends the rotational speed (Hz) of the compressor 3 at that time, which is simultaneously sent from the refrigerator controller 13, and the outside air temperature (outside store temperature) detected by the outside air temperature sensor 45 at that time. 8), the discharge refrigerant temperature PTd and the intake refrigerant temperature PTs are stored, whereby the detection data table shown in FIG. In this embodiment, as described above, the outside air temperature detected by the outside air temperature sensor 45 is set to a low temperature (for example, a temperature range of 10 ° C. or lower), a medium temperature (for example, a temperature range of higher than 10 ° C. to 20 ° C. or lower), and a high temperature ( For example, the detection data table is configured by associating each temperature zone with each temperature PTd, PTs, and the rotation speed (Hz) (FIG. 8).

  Next, the reference discharge temperature calculation unit 71 of the control unit 31 calculates the discharge temperature Td in step S1 of FIG. In the case of the embodiment, the reference discharge temperature calculating unit 71 sets the rotation speed 80 Hz (maximum frequency for control) of the compressor 3 as the reference rotation speed RNc, and the discharge refrigerant temperature PTd at the reference rotation speed RNc (80 Hz) for one day ( An average value for a predetermined period T1) is determined as the discharge temperature Td. Further, the reference discharge temperature calculation unit 71 calculates and determines the discharge temperature Td for each of the low temperature, medium temperature, and high temperature ranges described above.

  In addition, the reference intake temperature calculating unit 72 of the control unit 31 calculates the intake temperature Ts in the same manner at step S1. In the case of the embodiment, the reference intake temperature calculation unit 72 determines the average value for one day (predetermined period T1) of the intake refrigerant temperature PTs at the reference rotation speed RNc (80 Hz) of the compressor 3 as the intake temperature Ts. Further, the reference suction temperature calculation unit 72 calculates and determines the suction temperature Ts for each of the low temperature, medium temperature, and high temperature ranges described above.

  Next, the reference discharge temperature calculation unit 71 calculates and updates the reference discharge temperature RTd in step S2 of FIG. 7 (reference temperature update process). In the case of the embodiment, the reference discharge temperature calculation unit 71 sets the discharge temperature Td for each outside air temperature zone determined as described above for seven days (the predetermined period T2 is shorter than the predetermined period T2) in the embodiment. By calculating and moving average the discharge temperatures Td for these 7 days, the discharge temperature average value (moving average value) is continuously calculated for each outside air temperature zone, and the default discharge temperature average value calculated first is the default. Is written in the storage unit 32 as the reference discharge temperature RTd. When the latest discharge temperature average value is lower than the previous discharge temperature average value, the latest discharge temperature average value is updated by rewriting as the reference discharge temperature RTd. That is, the reference discharge temperature RTd is the lowest value of the discharge temperature average value (moving average value).

  FIG. 9 is a diagram for explaining the aggregation / calculation of the discharge temperature average value and the update process of the reference discharge temperature RTd. In FIG. 9, the latest discharge temperature average value is the moving average value for the past seven days. In this example, the reference discharge temperature RTd in the high temperature outside air temperature zone as of May 3 was 80 ° C., but the average discharge temperature in the high temperature outside air temperature zone counted on May 4 was 79 ° C. It can be seen that the reference discharge temperature RTd is updated from 80.degree. Further, the reference discharge temperature RTd in the low-temperature outside air temperature zone as of May 5 was 60 ° C., but the average discharge temperature value in the low-temperature outside air temperature zone calculated on May 6 decreased to 59 ° C. It can be seen that the reference discharge temperature RTd is updated from 60 ° C. to 59 ° C.

  In addition, the reference intake temperature calculation unit 72 calculates and updates the reference intake temperature RTs in step S2 (reference temperature update process). In the case of the embodiment, the reference intake temperature calculation unit 72 calculates the intake temperature Ts for each outside air temperature zone determined as described above for 7 days (the predetermined period T2; the predetermined period T1 is shorter than the predetermined period T2). The intake temperature average value (moving average value) is continuously calculated for each outside air temperature range by calculating and moving average the intake temperature Ts for 7 days. By default, the intake temperature average value calculated first is the default. Is stored in the storage unit 32 as the reference suction temperature RTs. Also in this case, when the latest intake temperature average value is lower than the previous intake temperature average value, the latest intake temperature average value is updated by rewriting as the reference intake temperature RTs. That is, the reference suction temperature RTs is similarly the lowest value of the suction temperature average value (moving average value).

  Next, the control unit 31 determines whether or not a predetermined refrigerant leak predictor flag is set in step S3. If it is assumed that the flag is reset here, the control unit 31 proceeds to step S4, and the reference for each outside air temperature zone from the storage unit 32. The discharge temperature RTd and the reference suction temperature RTs are acquired (read out). Next, in step S5, it is determined whether or not a predetermined determination start condition is satisfied. The determination start condition in the embodiment is whether or not the reference discharge temperature RTd and the reference suction temperature RTs are recorded in the storage unit 32.

Here, if it is assumed that the reference discharge temperature RTd and the reference suction temperature RTs have already been recorded in the storage unit 32 after seven days have elapsed since the start of operation, the control unit 31 proceeds to step S6. In this step S6, the refrigerant leakage determination unit 73 of the control unit 31 compares the discharge temperature Td with the reference discharge temperature RTd, and the suction temperature Ts and the reference suction temperature RTs to determine a predetermined detection condition for determining a refrigerant leak sign. It is determined whether or not is satisfied. The detection conditions for the refrigerant leak predictor determination in the embodiment are as follows.
(Discharge temperature Td−reference discharge temperature RTd) ≧ discharge temperature threshold STd and (suction temperature Ts−reference suction temperature RTs) ≧ suction temperature threshold STs have continued for a certain period T3 or more.

  (Discharge temperature Td−reference discharge temperature RTd) in the detection condition is a difference between the discharge temperature Td and the reference discharge temperature RTd, and indicates the degree of change in the discharge temperature Td with respect to the reference discharge temperature RTd. Further, the discharge temperature threshold STd is set to 7 ° C. in the embodiment. This 7 ° C. is set with reference to the temperature difference of 7.0 ° C. between the refrigerant amount of 50% and the full amount in the intermediate temperature outside air temperature range shown in FIG.

  In addition, (suction temperature Ts−reference suction temperature RTs) in the detection condition is a difference between the suction temperature Ts and the reference suction temperature RTs, and indicates the degree of change in the suction temperature Ts with respect to the reference suction temperature RTs. . In the embodiment, the suction temperature threshold value STs includes the low temperature (for example, a temperature range of 10 ° C. or less), the intermediate temperature (for example, the temperature range of higher than 10 ° C. and 20 ° C. or less), and the high temperature (for example, a temperature range of higher than 20 ° C.). The outside air temperature is divided into, for example, 5 ° C. for a low temperature outside air temperature zone, 7 ° C. for a medium outside air temperature zone, and 9 ° C. for a high temperature outside air temperature zone, for example. These values are set with reference to the temperature difference between the refrigerant amount of 50% and the full amount shown in FIG. In the actual measurement values shown in FIG. 14, the temperature difference when the outside air temperature is 10 ° C. is 5.0 ° C., 7.0 ° C. at 20 ° C., and 9.0 ° C. at 30 ° C. The suction temperature threshold value STs is changed in a higher direction as the temperature is higher.

  In addition, the fixed period T3 in the detection condition is set to 3 days in the embodiment. For example, the difference (Td−RTd) between the discharge temperature Td and the reference discharge temperature RTd in the low temperature outside air temperature zone is 7 ° C. (STd) or more, and the difference between the suction temperature Ts and the reference suction temperature RTs (Ts−RTs). ) Has reached 5 ° C. (STs) for 3 days (T3) or longer, and when the detection condition is satisfied in step S6, the refrigerant leakage determination unit 73 has a sign of refrigerant leakage from the refrigerant circuit RC (refrigerant The leakage predictor is detected) and the process proceeds to step S7 to set the refrigerant leak predictor flag described above.

  For example, in the case of the example in FIG. 9, the discharge temperature average value (average value for the past 7 days) in the low-temperature outside air temperature zone on May 15 is 67 ° C., so the discharge temperature Td is the same at this time. It is considered that the temperature is 67 ° C. Since the reference discharge temperature RTd in the low-temperature outside air temperature zone on May 15 is 59 ° C., the difference between them is 8 ° C., which is larger than the discharge temperature threshold STd (7 ° C. in the embodiment). Thereafter, on May 16, the difference is 9 ° C., on May 17, the difference is 8 ° C., and the discharge temperature threshold STd is equal to or higher than the discharge temperature threshold STd for 3 consecutive days. If it is equal to or greater than STs, the refrigerant leak determination unit 73 sets the refrigerant leak predictor flag as of May 17th.

  When the refrigerant leakage determination unit 73 sets the refrigerant leakage sign flag in step S7, the notification unit 74 of the control unit 31 performs a predetermined notification operation. An example of the notification operation in this case is shown in FIGS. 10 and 11 show the display unit 61 of the tablet terminal 41, it is assumed that a similar or equivalent notification operation is performed on the display unit 34 of the main controller 11.

  In the case of an Example, the alerting | reporting part 74 of the control part 31 of the main controller 11 performs alarm display (notification operation | movement) on its own display part 34, notifies the tablet terminal 41, and displays on the display part 61 of the tablet terminal 41. The alarm display of FIG. 10 and FIG. 11 is also performed. 10 and 11 show the display unit 61 of the tablet terminal 41, it is assumed that a similar or equivalent alarm display is performed on the display unit 34 of the main controller 11.

  In this case, the notification unit 74 of the control unit 31 changes the degree of urgency according to the time when the refrigerant leakage determination unit 73 sets the refrigerant leakage sign flag as having a sign of refrigerant leakage, and displays an alarm according to the degree of urgency ( Change the notification operation). For example, when the refrigerant leak predictor flag is set in the winter when the refrigeration load is relatively small, or when it is close to the date of the next periodic inspection (set in the storage unit 32) As shown in FIG. 10, an alarm message “There is a possibility that the refrigerant is leaking. Check it at the next periodic inspection.” Is displayed. On the other hand, when the refrigerant leak predictor flag is set in the summer when the refrigeration load is relatively large, or when a long period is available until the next periodic inspection date, as shown in FIG. "Please check it immediately." Is displayed.

  After setting the refrigerant leak predictor flag in step S7, the control unit 31 proceeds from step S3 to step S8. In step S8, it is determined whether or not a predetermined return condition is satisfied. In this embodiment, the return condition is whether or not 24 hours have elapsed since the refrigerant leak predictor flag was set. When the return condition is satisfied in step S8, that is, when 24 hours have elapsed since the refrigerant leakage determination unit 73 has determined that there is a refrigerant leakage sign, the control unit 31 proceeds to step S9 to indicate a refrigerant leakage sign. Reset the flag. The notification unit 74 receives this reset and stops (returns) the alarm display (notification operation) described above.

  As described above, in the present invention, the reference discharge temperature calculation unit 71 of the control unit 31 of the main controller 11 sets the predetermined rotation speed of the compressor 3 as the reference rotation speed RNc, and the discharge of the refrigerator controller 13 at the reference rotation speed RNc. The discharge temperature average value is continuously calculated by averaging the discharge temperature Td determined based on the value detected by the temperature sensor 30 for a predetermined period T2, and the latest discharge temperature average value is more recent than the previous discharge temperature average value. Is updated as the reference discharge temperature RTd, and the reference suction temperature calculation unit 72 is based on the value detected by the suction temperature sensor 35 of the refrigerator controller 13 at the reference rotational speed RNc. The determined suction temperature Ts is averaged for a predetermined period T2 to continuously calculate the suction temperature average value, and the latest suction temperature level is calculated from the previous suction temperature average value. When the value decreases, the latest average suction temperature value is updated as the reference suction temperature RTs, and the refrigerant leakage determination unit 73 sets the discharge temperature Td and the reference discharge temperature RTd, and the suction temperature Ts and the reference suction temperature RTs. In comparison, the discharge temperature Td rises with respect to the reference discharge temperature RTd, the degree of change (Td−RTd) exceeds a predetermined discharge temperature threshold STd, and the suction temperature Ts rises with respect to the reference suction temperature RTs. Since the degree of change (Ts−RTs) is equal to or higher than the predetermined suction temperature threshold value STs, it is determined that there is a sign of refrigerant leakage from the refrigerant circuit RC. Even in such a case, it is possible to determine the sign of refrigerant leakage at an early stage and notify the notification unit 74 of it.

  In particular, the reference discharge temperature RTd calculated by the reference discharge temperature calculation unit 71 and the reference suction temperature RTs calculated by the reference suction temperature calculation unit 72 are predetermined values of the discharge temperature Td and the suction temperature Ts at the reference rotation speed RNc of the compressor 3. Since it is an average value for the period T2 and is a value updated when the latest average value is lower than the previous average value calculated continuously, the refrigerant leakage determination unit 73 accurately detects the refrigerant leakage. It will be possible to determine the sign.

  In this case, as the degree of change of the discharge temperature Td with respect to the reference discharge temperature RTd, the difference (Td−RTd) between the discharge temperature Td and the reference discharge temperature RTd as in the embodiment can be adopted, but not limited thereto, the discharge temperature Td A ratio (Td / RTd) with the reference discharge temperature RTd can also be employed. Further, as the degree of change of the suction temperature Ts with respect to the reference suction temperature RTs, the difference (Ts−RTs) between the suction temperature Ts and the reference suction temperature RTs as in the embodiment can be adopted, but the suction temperature Ts and the reference suction temperature RTs The ratio (Ts / RTs) can also be adopted.

  In the embodiment, the reference discharge temperature calculation unit 71 calculates a discharge temperature average value by moving and averaging the discharge temperature Td for a predetermined period T2, and the reference suction temperature calculation unit 72 calculates the suction temperature Ts for a predetermined period T2. Since the average value of the suction temperature is calculated by moving average, it is possible to determine the sign of refrigerant leakage from the refrigerant circuit RC more quickly.

  In the embodiment, the reference discharge temperature calculation unit 71 determines a value obtained by averaging the value detected by the discharge temperature sensor 30 at the reference rotation speed RNc for a predetermined period T1 shorter than the predetermined period T2 as the discharge temperature Td, and the reference suction temperature Since the calculation unit 72 determines a value obtained by averaging the value detected by the suction temperature sensor 35 at the reference rotation speed RNc for a predetermined period T1 shorter than the predetermined period T2, the influence of the disturbance is eliminated. A more accurate refrigerant leak sign determination can be performed.

  Furthermore, in the embodiment, the refrigerant leakage determination unit 73 determines that the degree of change (Td−RTd) in the discharge temperature Td with respect to the reference discharge temperature RTd is equal to or higher than the discharge temperature threshold STd and the degree of change in the suction temperature Ts with respect to the reference suction temperature RTs ( When the state in which (Ts−RTs) is equal to or higher than the suction temperature threshold STs continues for a certain period T3 or longer, it is determined that there is a sign of refrigerant leakage from the refrigerant circuit RC. This makes it possible to perform an accurate refrigerant leak sign determination.

  In the embodiment, the reference discharge temperature calculation unit 71 determines the discharge temperature Td for each outside air temperature, calculates the reference discharge temperature RTd, and the reference suction temperature calculation unit 72 also determines the suction temperature Ts for each outside air temperature. In addition to calculating the reference suction temperature RTs, the refrigerant leakage determination unit 73 compares the discharge temperature Td with the reference discharge temperature RTd for each outside air temperature, and compares the suction temperature Ts with the reference suction temperature RTs to obtain the refrigerant circuit RC. Since it is determined whether or not there is a sign of refrigerant leakage from the outside, the influence of the outside air temperature can be eliminated and accurate refrigerant leakage sign determination can be performed.

  Further, in the embodiment, the refrigerant leakage determination unit 73 changes the suction temperature threshold value STs in a direction to increase the higher the outside air temperature, so that it is possible to perform a quicker and more accurate refrigerant leakage sign determination. become. In the embodiment, the discharge temperature threshold value STd is set to a constant value (7 ° C.). However, as shown in FIG. 13, the temperature difference of the discharge temperature Td also decreases as the outside air temperature increases. The temperature threshold value STd may be changed in a direction of lowering as the outside air temperature is higher.

  In this case, the discharge temperature threshold value STd is set to, for example, the above-described low temperature (for example, a temperature range of 10 ° C. or lower), medium temperature (for example, a temperature range of higher than 10 ° C. and lower than 20 ° C.), and high temperature (for example, a temperature range of higher than 20 ° C.). The outside air temperature is divided into, for example, 10 ° C. for a low temperature outside air temperature zone, 7 ° C. for a medium outside air temperature zone, and 5 ° C. for a high temperature outside air temperature zone, for example. These values may be set with reference to the temperature difference between the refrigerant amount of 50% and the full amount shown in FIG. That is, in the actual measurement values shown in FIG. 13, the temperature difference when the outside air temperature is 10 ° C. is 10.0 ° C., 7.0 ° C. at 20 ° C., and 5.0 ° C. at 30 ° C. However, the higher the outside air temperature, the more the discharge temperature threshold STd is changed in the direction of lowering. That is, both or either one of the suction temperature threshold value STs and the discharge temperature threshold value STd may be changed.

  Further, in the embodiment, the notification unit 74 of the control unit 31 changes the corresponding urgency level according to the timing when the refrigerant leakage determination unit 73 determines that there is a sign of refrigerant leakage, so that the refrigeration load In the winter when the temperature is relatively small, a notification that allows a marginal response is performed (FIG. 10), and in the summer when the refrigeration load is large, a notification that requests a quick response is performed (FIG. 11). It is possible to avoid inconvenience that results in an unnecessarily quick response.

  The present invention includes a plurality of showcases 2 provided with an evaporator 6 and a refrigerator 4 provided with a compressor 3 as in the embodiment, and the compressor 3 is constituted by refrigerant pipes (a high pressure pipe 8 and a low pressure pipe 9). Thus, the main controller 11 is extremely effective for predicting and reporting refrigerant leakage in the refrigerating apparatus R that centrally controls the operation of each showcase 2 and the refrigerator 4.

  Next, FIG. 12 is a diagram for explaining the communication line of the centralized management device 1 of another embodiment including the refrigeration apparatus R to which the present invention is applied and the piping configuration of the refrigeration apparatus R. In this figure, the same reference numerals as those in FIG. 1 indicate the same or similar functions.

  In the case of this embodiment, the main controller 11 and the POS terminal 76 in FIG. 1 are not provided. Instead, a function of performing wireless communication of information (data) via the wireless LAN with the tablet terminal 41 is added to each connection case controller 12 and refrigerator controller 13. Then, data related to operation information (including alarm information) is collected from each connection case controller 12 and the refrigerator controller 13 by wireless communication with the tablet terminal 41, and instruction information is transmitted to each connection case controller 12 and the refrigerator controller 13. Then, it is configured so that it can be centrally managed.

  The control unit 63 of the tablet terminal 41 also has a function as a so-called POS terminal from inventory management to sales management of the store. Thereby, the tablet terminal 41 becomes a POS terminal.

  Thus, the instruction information is transmitted by wireless communication from the tablet terminal 41 to each connection case controller 12, the refrigerator controller 13, and the non-connection case controller 47, and from the connection case controller 12, the refrigerator controller 13, and the non-connection case controller 47. 1 transmits the operation information including the alarm information to the tablet terminal 41 by wireless communication, and the operation of each device is intensively managed by the tablet terminal 41, without going through the main controller 11 of FIG. In addition, the devices provided in the store are centrally managed by the tablet terminal 41, and the control of the refrigerant leakage sign similar to the above can be realized by the control unit 63 of the tablet terminal 41.

  Further, by making the tablet terminal 41 a POS terminal provided in a store, it is not necessary to provide the tablet terminal 41 and the POS terminal separately, and the facility cost is reduced.

  In the embodiment, the notification operation by the notification unit 74 is displayed as characters as shown in FIGS. 10 and 11, and the contents of the displayed characters are changed. However, the present invention is not limited to this. For example, in the case of FIG. Characters may be displayed and displayed in red in the case of FIG. 11 so that the urgency can be further impressed. Also, the letters to be displayed are the same (for example, “Please check because there is a possibility that the refrigerant is leaking”), and if the refrigerant leak predictor flag is set in winter or the next time If it is close to the date of the periodic inspection, it will be displayed in yellow.If the refrigerant leak predictor flag is set in the summer, or if there is a long period before the next periodic inspection date, it will be red. You may make it alert | report by changing an emergency degree by displaying etc.

  In the embodiment, the change degree of the discharge temperature Td with respect to the reference discharge temperature RTd is set as a difference (Td−RTd), and the change degree of the suction temperature Ts with respect to the reference suction temperature RTs is set as a difference (Ts−RTs). The ratio (Td / RTd) between the discharge temperature Td and the reference discharge temperature RTd is the degree of change in the discharge temperature Td with respect to the reference discharge temperature RTd, and the ratio (Ts / RTs) between the suction temperature Ts and the reference suction temperature RTs is the reference suction. The degree of change of the suction temperature Ts with respect to the temperature RTs may be used. Furthermore, the present invention is not limited to these differences and ratios, and the refrigerant leakage signs may be determined by combining the differences and ratios. From the degree of change in the discharge temperature Td from the reference discharge temperature RTd and the reference suction temperature RTs. Any factor that can determine the degree of change in the intake temperature Ts can be applied.

  In the embodiment, the rotation speed of the compressor 3 is set to 80 Hz as the reference rotation speed RNc, and the discharge temperature Td and the suction temperature Ts are calculated and determined from the discharge refrigerant temperature PTd and the suction refrigerant temperature PTs at that time. For example, the rotation speed of the compressor 3 is regularly set to a reference rotation speed RNc (80 Hz) for a certain period of time during a specific time period of the day, and the discharge refrigerant temperature PTd and the intake refrigerant temperature PTs within the period are used. The discharge temperature Td and the suction temperature Ts may be calculated and determined.

  In the embodiment, the reference discharge temperature calculation unit 71 calculates a discharge temperature average value by moving and averaging the discharge temperature Td for a predetermined period T2, and the reference suction temperature calculation unit 72 calculates the suction temperature Ts for a predetermined period T2. Although the suction temperature average value is calculated by moving average, the invention other than claim 3 is not limited to this, and a simple average of the discharge temperature Td and the suction temperature Ts for a predetermined period T2 is continuously calculated. It may be.

  Furthermore, in the embodiment, the outside air temperature is classified into low temperature, medium temperature, and high temperature ranges, but the present invention is not limited to this, and for example, the outside air temperature may be classified every 1 ° C. Each period can be appropriately changed according to the device to be applied without departing from the gist of the present invention.

  Furthermore, in the embodiment, the present invention is applied to the refrigeration apparatus R composed of the plurality of showcases 2 and the refrigerators 4. However, the invention other than the ninth aspect is not limited thereto, and for example, in FIG. 1 and FIG. You may apply to the non-show showcase 2 shown. In that case, the showcase 2 becomes a refrigeration apparatus, the discharge refrigerant temperature of the compressor 43 detected by the discharge temperature sensor 30 of the unconnected case controller 47 or the tablet terminal 41, and the compressor 43 detected by the suction temperature sensor 35. Based on the suction refrigerant temperature, the discharge temperature Td and the suction temperature Ts, the reference discharge temperature RTd and the reference suction temperature RTs are calculated and compared in the same manner as described above to determine a sign of refrigerant leakage from the refrigerant circuit of the unconnected showcase 2. To notify in the same manner as described above. However, the rise in the outside air temperature is collected by the tablet terminal 41 from the main controller 11 and supplied to the non-connection case controller 47.

DESCRIPTION OF SYMBOLS 1 Centralized management apparatus 2 Showcase 3 Compressor 4 Refrigerator 11 Main controller (control apparatus)
12 Connection case controller (control device)
13 Refrigerator controller (control device)
14 Communication Line 30 Discharge Temperature Sensor 31 Control Unit 35 Suction Temperature Sensor 40 Outside Air Temperature Sensor 41 Tablet Terminal (Control Device)
45 Outside temperature sensor 47 Unconnected case controller (control device)
71 Reference Discharge Temperature Calculation Unit 72 Reference Intake Temperature Calculation Unit 73 Refrigerant Leakage Determination Unit 74 Notification Unit

Claims (9)

In the refrigeration apparatus provided with a control device for circulating the refrigerant in the refrigerant circuit by the compressor and controlling the rotation speed of the compressor,
The control device includes:
A discharge temperature sensor for detecting a discharge refrigerant temperature of the compressor;
An intake temperature sensor for detecting an intake refrigerant temperature of the compressor;
A reference discharge temperature calculator for calculating a reference discharge temperature RTd;
A reference suction temperature calculator for calculating a reference suction temperature RTs;
A refrigerant leakage determination unit for determining refrigerant leakage from the refrigerant circuit;
With a notification unit,
The reference discharge temperature calculation unit sets a predetermined rotation speed of the compressor as a reference rotation speed RNc, and calculates a discharge temperature Td determined based on a value detected by the discharge temperature sensor at the reference rotation speed RNc for a predetermined period. When the discharge temperature average value is continuously calculated by averaging and the latest discharge temperature average value is lower than the previous discharge temperature average value, the latest discharge temperature average value is used as the reference discharge temperature RTd. Updated,
The reference intake temperature calculation unit continuously calculates the intake temperature average value by averaging the intake temperature Ts determined based on the value detected by the intake temperature sensor at the reference rotation speed RNc for a predetermined period; When the latest suction temperature average value is lower than the previous suction temperature average value, the latest suction temperature average value is updated as the reference suction temperature RTs,
The refrigerant leakage determination unit compares the discharge temperature Td with the reference discharge temperature RTd and the suction temperature Ts with the reference suction temperature RTs, and the discharge temperature Td increases with respect to the reference discharge temperature RTd. The degree of change is equal to or higher than a predetermined discharge temperature threshold STd, the suction temperature Ts is increased with respect to the reference suction temperature RTs, and the degree of change is equal to or higher than a predetermined suction temperature threshold STs. While determining that there is a sign of refrigerant leakage from the refrigerant circuit,
The informing unit performs a predetermined informing operation when the refrigerant leakage determining unit determines that there is a sign of refrigerant leakage. The degree of change in the discharge temperature Td with respect to the reference discharge temperature RTd is the difference between the discharge temperature Td and the reference discharge temperature RTd (Td−RTd) or the ratio between the discharge temperature Td and the reference discharge temperature RTd ( Td / RTd),
The degree of change of the suction temperature Ts with respect to the reference suction temperature RTs is the difference between the suction temperature Ts and the reference suction temperature RTs (Ts−RTs), or the ratio of the suction temperature Ts and the reference suction temperature RTs ( The refrigeration apparatus according to claim 1, wherein Ts / RTs). The reference discharge temperature calculation unit calculates the discharge temperature average value by moving and averaging the discharge temperature Td for the predetermined period,
3. The refrigeration apparatus according to claim 1, wherein the reference intake temperature calculation unit calculates the intake temperature average value by moving and averaging the intake temperature Ts for the predetermined period. The reference discharge temperature calculation unit determines, as the discharge temperature Td, an average value of a value detected by the discharge temperature sensor at the reference rotation speed RNc for a period shorter than the predetermined period,
The reference suction temperature calculation unit determines, as the suction temperature Ts, a value obtained by averaging a value detected by the suction temperature sensor for a period shorter than the predetermined period at the reference rotation speed RNc. The refrigeration apparatus according to claim 3.   The refrigerant leakage determination unit has a degree of change of the discharge temperature Td with respect to the reference discharge temperature RTd equal to or higher than the discharge temperature threshold STd, and a degree of change of the suction temperature Ts with respect to the reference suction temperature RTs is the suction temperature threshold STs. 5. The refrigeration apparatus according to claim 1, wherein when the above state continues for a certain period or longer, it is determined that there is a sign of refrigerant leakage from the refrigerant circuit. The control device includes an outside temperature sensor for detecting outside temperature,
The reference discharge temperature calculation unit determines the discharge temperature Td for each outside air temperature, calculates the reference discharge temperature RTd,
The reference intake temperature calculating unit determines the intake temperature Ts for each outside air temperature, calculates the reference intake temperature RTs,
The refrigerant leakage determination unit compares the discharge temperature Td with the reference discharge temperature RTd and the suction temperature Ts with the reference suction temperature RTs for each outside air temperature, and predicts refrigerant leakage from the refrigerant circuit. 6. The refrigeration apparatus according to any one of claims 1 to 5, wherein it is determined whether or not it exists. The control device includes an outside temperature sensor for detecting outside temperature,
The refrigerant leakage determination unit changes the suction temperature threshold value STs in a direction to increase as the outside air temperature increases, and / or changes the discharge temperature threshold value STd in a direction to decrease as the outside air temperature increases. The refrigeration apparatus according to any one of claims 1 to 6, wherein the refrigeration apparatus is any one of claims 1 to 6.   8. The notification unit according to any one of claims 1 to 7, wherein the notification unit changes the corresponding urgency level according to a timing when the refrigerant leakage determination unit determines that there is a sign of refrigerant leakage. The refrigeration apparatus described in 1. A plurality of showcases each provided with an evaporator, and a refrigerator provided with the compressor, and distributing and supplying refrigerant from the compressor to each evaporator through a refrigerant pipe,
The refrigeration apparatus according to any one of claims 1 to 8, wherein the control device centrally controls the operation of each showcase and the refrigerator.

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