Cooling storage

Abstract

To provide a cooling storage capable of appropriately operating a compressor in the event of communication failure between a control part and a compressor control part.SOLUTION: A cooling storage comprises a compressor 25, a control part 40, a compressor control part 52 for controlling operation of the compressor 25, and a communication part 51. When a first communication failure, which is an abnormality in communication from the compressor control part 52 to the communication part 51, occurs and the compressor 25 is operating, the control part 40 executes first processing in which a preset first rotational speed R1 is transmitted to the communication part 51 as a target rotational speed RM. When the first communication failure occurs and the compressor 25 is stopped, the control part 40 keeps the compressor 25 stopped until a measured temperature TS reaches an upper limit set temperature T3, which is obtained by adding a first predetermined temperature T1 to a target set temperature TM, and upon the measured temperature TS reaching or exceeding the upper limit set temperature T3, executes second processing in which the first rotational speed R1 is transmitted to the communication part 51 as the target rotational speed RM.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The technology disclosed herein relates to a refrigerated storage facility. [Background technology]

[0002] A conventionally known refrigerated storage cabinet is described in Patent Document 1. The refrigerated storage cabinet described in Patent Document 1 includes a storage chamber in which stored items are housed, a compressor that compresses a refrigerant, a cooler that cools the surrounding air by evaporating the refrigerant compressed by the compressor, and a cooling fan that sends the cold air generated by the cooler into the storage chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-317073 Summary of the Invention [Problem to be solved by the invention]

[0004] In a known configuration including a compressor as described above, the use of a compressor with a variable rotation speed (e.g., an inverter-type compressor) allows for more efficient cooling of the storage compartment. In this case, a dedicated compressor control unit is typically provided to control the operation of the compressor, separate from the main control unit that controls each component of the refrigerated storage compartment. For example, the compressor control unit controls the compressor rotation speed to a target rotation speed determined by the main control unit. The compressor control unit is typically a general-purpose product manufactured by the same compressor manufacturer. Using such a general-purpose product allows manufacturers of refrigerated storage compartments to manufacture refrigerated storage compartments at lower cost. However, the main control unit and the compressor control unit may use different communication methods (more specifically, data exchange methods). When the control unit and the compressor control unit use different communication methods, a communication unit is required to communicate between the control unit and the compressor control unit. When the control unit and the compressor control unit communicate via the communication unit, there is a concern that communication errors may occur due to electrical noise or other factors. Conventionally, a response to a communication error is to stop the compressor. However, stopping the compressor results in an increase in the temperature inside the storage compartment.

[0005] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a refrigerated storage facility that can operate the compressor appropriately when a communication abnormality occurs in the communication between the control unit and the compressor control unit. [Means for solving the problem]

[0006] As a means for solving the above-mentioned problems, the present specification discloses a cooling storage facility comprising: a storage chamber in which stored items are stored; a compressor that compresses a refrigerant; a cooler that cools surrounding air by evaporating the refrigerant compressed by the compressor; a cooling fan that sends the air cooled by the cooler to the storage chamber; a storage chamber temperature sensor that measures the temperature of the storage chamber; a control unit; a compressor control unit that controls the operation of the compressor; and a communication unit that performs communication between the control unit and the compressor control unit, wherein the control unit controls the operation of the cooling fan and executes a cooling operation that determines a target rotation speed of the compressor so that the measured temperature of the storage chamber measured by the storage chamber temperature sensor becomes a predetermined target set temperature, and during the cooling operation, the compressor control unit controls the rotation speed of the compressor to: The operation of the compressor is controlled so that the target rotation speed is the target rotation speed transmitted from the control unit via the communication unit. During the cooling operation, if a first communication anomaly occurs, which is an anomaly related to communication from the compressor control unit to the communication unit, and the compressor is operating, the control unit executes a first process of setting a predetermined first rotation speed as the target rotation speed and transmitting it to the communication unit. During the cooling operation, if the first communication anomaly occurs and the compressor is stopped, the control unit stops the compressor until the measured temperature reaches an upper limit set temperature obtained by adding a first predetermined temperature to the target set temperature, and then, if the measured temperature becomes equal to or higher than the upper limit set temperature, executes a second process of setting the first rotation speed as the target rotation speed and transmitting it to the communication unit.

[0007] Furthermore, if during the cooling operation a second communication abnormality, which is an abnormality related to communication from the communication unit to the compressor control unit, continues for a first predetermined time and the compressor is operating, the compressor control unit can execute a third process of operating the compressor at the rotation speed at the time the second communication abnormality occurred for a second predetermined time after the occurrence of the second communication abnormality, and then stopping the compressor. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a refrigerated storage facility that can operate the compressor appropriately when a communication abnormality occurs in the communication between the control unit and the compressor control unit. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view showing a cooling storage cabinet according to a first embodiment of the present invention; [Figure 2] Cross-section showing the cooling storage facility [Figure 3] A diagram showing the cooling cycle of the cooling storage facility [Figure 4] Block diagram showing the electrical configuration of the cooling storage facility [Figure 5] 10 is a flowchart showing the operation of the control unit when a first communication abnormality occurs. [Figure 6] A flowchart showing the operation of the compressor control unit when a second communication abnormality occurs. [Figure 7] FIG. 10 is a front view showing a cooling storage cabinet according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Embodiment 1> A first embodiment of the present invention will be described with reference to FIGS. 1 to 6. The symbols F, Rr, L, R, U, and D shown in FIGS. 1 and 2 respectively indicate the front and rear in the longitudinal direction of the refrigerated storage cabinet 10, the left and right in the width direction when viewed from the front, and the top and bottom in the vertical direction. In this embodiment, as shown in FIG. 1, an upright refrigerator is exemplified as the refrigerated storage cabinet 10. As shown in FIGS. 1 and 2, the refrigerated storage cabinet 10 includes a storage cabinet main body 12, which is an insulated box having a storage chamber 11 for accommodating stored items, a machine room 14 provided above the storage cabinet main body 12, and a cooling device 13 (see FIG. 3). The front surface (the left side in FIG. 2) of the storage cabinet main body 12 is open, and the opening is partitioned by a partition frame 15 extending horizontally. As a result, the storage chamber 11 has two openings 11A, 11A arranged vertically.

[0011] A pair of left and right doors 16, 16 are attached to the storage cabinet main body 12 in two vertical rows. Each door 16 is attached to the storage cabinet main body 12 so that it can rotate at its side edge. This allows the opening 11A to be opened and closed by the door 16. The storage cabinet main body 12 is supported by legs 18 provided at the four corners of the bottom surface. Furthermore, as shown in FIG. 2, shelves 17 are provided in the storage chamber 11 in a horizontal direction, and items stored in the storage chamber 11 can be placed on the shelves 17.

[0012] A drain pan 34, which also serves as a cooling duct, is disposed at the top of the storage body 12, sloping downward toward the rear (right side in FIG. 2). This forms a cooler chamber 35 above the drain pan 34. The cooler chamber 35 houses the cooler 28. A motor-driven cooling fan 29 is provided in front of the drain pan 34, and a cool air outlet 38 is formed at the rear of the drain pan 34. This makes it possible to circulate air between the storage chamber 11 and the cooler chamber 35 by driving the cooling fan 29.

[0013] 3, the cooling device 13 includes an outdoor unit 21, a cooler 28, a cooling fan 29, a capillary tube 30 (or an expansion valve), a storage chamber temperature sensor 44, a cooler temperature sensor 45, and a defrost heater 46. The outdoor unit 21 includes a compressor 25 that compresses the refrigerant, a condenser 26, and a condenser fan 27 that cools the condenser 26.

[0014] The compressor 25, condenser 26, capillary tube 30, and cooler 28 are circulated and connected by refrigerant piping 24 to form a cooling cycle. A non-flammable refrigerant (e.g., R448A) is sealed in the refrigerant pipe. However, the refrigerant is not limited to this, and a flammable refrigerant (e.g., propane, isobutane, etc.) may also be used. The cooler 28 is capable of cooling the surrounding air by evaporating the refrigerant compressed by the compressor 25. The cooling fan 29 is capable of sending the air (cold air) cooled by the cooler 28 to the storage chamber 11.

[0015] A storage chamber temperature sensor 44 is disposed above the cooling fan 29 in the cooler chamber 35. The storage chamber temperature sensor 44 is capable of measuring the temperature of the air in the storage chamber 11 sucked in by the cooling fan 29 (and thus the temperature inside the storage chamber 11). A cooler temperature sensor 45 that measures the temperature of the cooler 28 is attached to the cooler 28. A defrost heater 46, which is formed of, for example, a sheath heater, is provided on the underside of the cooler 28. The defrost heater 46 is provided to remove frost that has adhered to the cooler 28.

[0016] Next, the electrical configuration of the refrigerated storage cabinet 10 will be described. As shown in Fig. 4, the refrigerated storage cabinet 10 includes a control unit 40. The control unit 40 is electrically connected to a memory unit 41, a display unit 42, a timer unit 43, a storage chamber temperature sensor 44, a cooler temperature sensor 45, a condenser fan 27, a cooling fan 29, and a defrost heater 46. The compressor 25 is also electrically connected to the control unit 40 via a communication unit 51 and a compressor control unit 52.

[0017] The control unit 40 is mainly composed of, for example, a CPU, and the memory unit 41 is composed of, for example, a ROM, a RAM, etc. Various parameters (such as a target set temperature, which will be described later) related to the operation of the refrigerated storage cabinet 10 are stored in the memory unit 41. The control unit 40, the memory unit 41, the timer unit 43, and the communication unit 51 are housed, for example, in an electrical box 36 (see FIG. 2) disposed in the machine room 14, but are not limited to this. The compressor control unit 52 is housed in a housing that constitutes the outdoor unit 21.

[0018] The display unit 42 includes, for example, an LCD display and indicator lamps, and is provided on the outer surface of the storage cabinet main body 12. The display unit 42 displays various information related to the refrigerated storage cabinet 10 (such as the temperature inside the cabinet and error messages). The display unit 42 is configured, for example, by an LCD panel. As shown in FIG. 1, the front of the machine room 14 is configured by an openable front cover 14A, and the display unit 42 is disposed on the back side of the front cover 14A. An operator can view the display unit 42 from the front through a transparent member 19 (such as glass) provided on the front cover 14A. The timing unit 43 is configured to measure the time.

[0019] The communication unit 51 communicates between the control unit 40 and the compressor control unit 52. The compressor control unit 52 includes an inverter circuit and the like, and controls the operation of the compressor 25. The compressor control unit 52 transmits, for example, the following information A to E to the communication unit 51 as information related to the control of the compressor 25. Information A: Information on whether the compressor 25 is operating or stopped Information B: Compressor 25 rotation speed Information C: Inverter circuit error code Information D: Inverter circuit temperature Information E: Inverter circuit current value The compressor control unit 52 puts the above information A to E into each packet and transmits it to the communication unit 51. The communication unit 51 collects the information A to E sent from the compressor control unit 52 into one packet and transmits it to the control unit 40.

[0020] In response to this, the control unit 40 transmits, for example, the following information F and G to the communication unit 51 as information related to the control of the compressor 25. Information F: Instruction to operate or stop the compressor 25 Information G: Target rotation speed R1 of compressor 25 The control unit 40 collects the information F and G into one packet and transmits it to the communication unit 51. The communication unit 51 puts the information F and G sent from the control unit 40 into each packet and transmits it to the compressor control unit 52. By going through the communication unit 51 in this way, it is possible to exchange information between the control unit 40 and the compressor control unit 52, which have different information transmission and reception methods (methods of storing information in packets).

[0021] Next, the processing of the control unit 40 and the compressor control unit 52 will be described. The control unit 40 controls the operation of the cooling fan 29 and the condenser fan 27 so that the measured temperature TS of the storage compartment 11 measured by the storage compartment temperature sensor 44 becomes a preset target set temperature TM, and also executes a cooling operation to determine a target rotation speed R1 of the compressor 25. In the cooling operation, the compressor control unit 52 controls the operation of the compressor 25 so that the rotation speed of the compressor 25 becomes the target rotation speed RM transmitted from the control unit 40 via the communication unit 51.

[0022] When cooling fan 29 is driven, air in storage chamber 11 is sucked into cooler chamber 35 as shown by arrow P1 in Fig. 2, and then the cool air generated by heat exchange while passing through cooler 28 is blown out from blowout section 38 into storage chamber 11 as shown by arrow P2. In this way, the cool air is circulated and supplied within storage chamber 11, thereby cooling storage chamber 11.

[0023] In the cooling operation, the control unit 40 drives the compressor 25, the condenser fan 27, and the cooling fan 29 when the measured temperature TS measured by the storage chamber temperature sensor 44 is equal to or higher than a preset set temperature TS1 (target set temperature TM + predetermined temperature TA), and stops the compressor 25 and the condenser fan 27 when the measured temperature TS reaches a preset set temperature TS2 (target set temperature TM - predetermined temperature TB). This maintains the temperature of the storage chamber 11 near the target set temperature TM. The predetermined temperature TA is set to, for example, 1.7 K, and the predetermined temperature TB is set to, for example, 2 K, but is not limited thereto. The target set temperature TM can be set within a range of, for example, -6°C to +12°C, but is not limited thereto.

[0024] Compressor 25 is an inverter compressor capable of switching the rotation speed in multiple stages, and the target rotation speed RM of compressor 25 is determined, for example, in six stages (0th speed: 30 Hz, 1st speed: 42 Hz, 2nd speed: 54 Hz, 3rd speed: 66 Hz, 4th speed: 78 Hz, 5th speed: 90 Hz). During cooling operation, control unit 40 calculates the deviation between measured temperature TS and target set temperature TM at regular time intervals, and sets target rotation speed RM higher as the deviation increases, and sets target rotation speed RM lower as the deviation decreases.

[0025] The control unit 40 also executes a defrosting operation to defrost the cooler 28. Examples of defrosting operations include off-cycle defrosting and heater defrosting. The off-cycle defrosting is a defrosting method in which the compressor 25 and the condenser fan 27 are stopped and the cooling fan 29 is operated, while the heater defrosting is a defrosting method in which the compressor 25, the condenser fan 27, and the cooling fan 29 are stopped and the cooler 28 is heated by the defrost heater 46. The cooling operation and the defrosting operation are performed alternately, and the defrosting operation is performed, for example, every predetermined time (e.g., every few hours).

[0026] 5, if a first communication abnormality occurs during the cooling operation, which is an abnormality related to communication from compressor control unit 52 to communication unit 51 ("YES" in step S11) and compressor 25 is operating ("YES" in step S12), control unit 40 executes a first process of transmitting a preset first rotation speed R1 as a target rotation speed RM to communication unit 51 (step S13). As a result, compressor control unit 52 controls compressor 25 to operate at first rotation speed R1.

[0027] 5, if a first communication anomaly occurs during the cooling operation ("YES" in step S11) and compressor 25 is stopped ("NO" in step S12), control unit 40 stops compressor 25 until measured temperature TS reaches upper limit set temperature T3, which is obtained by adding target set temperature TM to first predetermined temperature T1, and then, if measured temperature TS becomes equal to or higher than upper limit set temperature TS3, executes a second process of transmitting first rotation speed R1 as target rotation speed RM to communication unit 51 (step S14). As a result, compressor control unit 52 controls compressor 25 to operate at first rotation speed R1.

[0028] The first rotation speed R1 is set to, for example, 30 Hz (speed 0), but is not limited to this. For example, when applied to a freezer in which the target set temperature TM is set lower than that of a refrigerator, the first rotation speed R1 may be set to a higher value (for example, speed 2: 54 Hz). The first rotation speed R1 is the minimum rotation speed required to maintain the temperature inside the storage chamber 11, and is set appropriately based on the volume of the storage chamber 11, the cooling performance of the cooling device 13, etc. The first predetermined temperature T1 is set to, for example, the same value as the predetermined temperature TA (for example, 1.7 K), but is not limited to this.

[0029] Also, as shown in FIG. 6, if a second communication abnormality, which is an abnormality related to communication from the communication unit 51 to the compressor control unit 52, continues for a first predetermined time X1 during cooling operation ("YES" in step S21) and the compressor 25 is operating ("YES" in step S22), the compressor control unit 52 operates the compressor 25 at the rotation speed at the time the second communication abnormality occurred for a second predetermined time X2 after the second communication abnormality occurred, and then executes a third process to stop the compressor 25 (step S23).

[0030] For example, the first predetermined time X1 is set to 10 seconds, and the second predetermined time X2 is set to 100 seconds, but is not limited to these. A minimum operating time is set for the compressor 25 to prevent breakdown, and the second predetermined time X2 is set based on this minimum operating time. In other words, the second predetermined time X2 is set to a length equal to or greater than the minimum operating time or as close to the minimum operating time as possible.

[0031] In addition, the communication unit 51 is capable of detecting the occurrence of a first communication abnormality and a second communication abnormality, and is capable of transmitting information to the control unit 40 that the first communication abnormality and the second communication abnormality have occurred.

[0032] Next, the effects of this embodiment will be described. If a first communication abnormality occurs while compressor 25 is operating, by executing the first process, compressor 25 can be operated at first rotation speed R1, and a rise in temperature in storage chamber 11 can be suppressed. Furthermore, if a first communication abnormality occurs while compressor 25 is stopped, control unit 40 executes the second process. The fact that compressor 25 is stopped means that the temperature in storage chamber 11 is lower than set temperature TS1 (target set temperature TM + predetermined temperature TA) and storage chamber 11 is cold. Therefore, in the second process, by stopping compressor 25 until measured temperature TS reaches upper limit set temperature T3, it is possible to suppress a situation in which the temperature in storage chamber 11 becomes too low.

[0033] Furthermore, if a second communication abnormality, which is an abnormality related to communication from the communication unit 51 to the compressor control unit 52, continues for a first predetermined time X1 during cooling operation and the compressor 25 is operating, the compressor control unit 52 operates the compressor 25 at the rotation speed at the time the second communication abnormality occurred for a second predetermined time X2 after the second communication abnormality occurred, and then executes a third process to stop the compressor 25.

[0034] If the continuous operation time of the compressor 25 is extremely short, oil will not be supplied sufficiently to the sliding parts between the components constituting the compressor 25, causing wear and resulting in a malfunction. In the above configuration, if a second communication abnormality occurs, the compressor 25 can be operated for only the second predetermined time X2. This prevents the continuous operation time of the compressor 25 from becoming extremely short compared to the minimum operation time set for the compressor 25, thereby preventing a malfunction of the compressor 25. Note that if a second communication abnormality occurs, it becomes difficult for the compressor control unit 52 to receive the target rotation speed RM transmitted from the control unit 40. Therefore, the compressor control unit 52 executes the third process to control the rotation speed of the compressor 25.

[0035] Furthermore, in this embodiment, the compressor 25 and compressor control unit 52 are disposed in the outdoor unit 21, and the control unit 40 and communication unit 51 are disposed in the electrical equipment box 36. In this configuration, the wiring distance between the communication unit 51 and the compressor control unit 52 is longer than in a configuration in which the communication unit 51 and the compressor control unit 52 are disposed in the same location, making communication failures more likely to occur. This embodiment is preferable because it allows the compressor 25 to operate appropriately when a communication failure occurs.

[0036] <Embodiment 2> Next, a second embodiment of the present invention will be described with reference to FIG. 7. The same parts as those in the above embodiment will be assigned the same reference numerals, and duplicated descriptions will be omitted. In this embodiment, a prefabricated refrigerator will be exemplified as the refrigerated storage cabinet 110. As shown in FIG. 7, the refrigerated storage cabinet 110 comprises a storage cabinet main body 112 having a storage chamber 111 in which stored items are accommodated, and a cooling device 113. The storage cabinet main body 112 (insulated box body) is constructed by assembling a plurality of insulating panels into a box shape. An opening 116 that serves as an entrance and exit is formed in the storage cabinet main body 112, and the opening 116 can be opened and closed by an insulating door 117.

[0037] The cooling device 113 includes an outdoor unit 121, an indoor unit 122, a control box 123, and refrigerant piping (not shown) that circulates and connects the outdoor unit 121 and the indoor unit 122. The outdoor unit 121 includes a compressor 25, a condenser 26, and a condenser fan 27 (see FIG. 3), similar to the first embodiment.

[0038] The indoor unit 122 includes a cooler 28, a cooling fan 29, a capillary tube 30 (or an expansion valve), a storage chamber temperature sensor 44, a cooler temperature sensor 45, and a defrost heater 46 (see FIG. 3). In this embodiment, the control unit 40, the memory unit 41, the timer unit 43, and the communication unit 51 are housed in, for example, a control box 123, and the compressor control unit 52 is housed in a housing that constitutes the outdoor unit 121.

[0039] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and the following embodiments, for example, are also included in the technical scope. (1) In the above embodiment, a refrigerator is used as an example of a cooling storage unit. However, the cooling storage unit is not limited to a refrigerator and may be a showcase, a freezer, or the like. (2) In the above embodiment, the rotation speed of the compressor 25 can be changed in stages. However, the present invention is not limited to this. (3) The information processed by the communication unit 51 is not limited to the information exemplified in the above embodiment (information A to G) and can be changed as appropriate. [Explanation of symbols]

[0040] 10,110... refrigerated storage, 11... storage room, 25... compressor, 28... cooler, 29... cooling fan, 40... control unit, 44... storage room temperature sensor, 51... communication unit, 52... compressor control unit, R1... first rotation speed, RM... target rotation speed, T1... first predetermined temperature, T3... upper limit set temperature, TS... measured temperature, TM... target set temperature, X1... first predetermined time, X2... second predetermined time

Claims

1. a storage chamber in which the stored items are stored; a compressor that compresses a refrigerant; a cooler that cools surrounding air by evaporating the refrigerant compressed by the compressor; a cooling fan that sends the air cooled by the cooler to the storage chamber; a storage chamber temperature sensor for measuring the temperature of the storage chamber; A control unit; a compressor control unit that controls the operation of the compressor; a communication unit that performs communication between the control unit and the compressor control unit; Equipped with the control unit executes a cooling operation to control the operation of the cooling fan and determine a target rotation speed of the compressor so that the temperature of the storage compartment measured by the storage compartment temperature sensor becomes a predetermined target set temperature, In the cooling operation, the compressor control unit controls the operation of the compressor so that the rotation speed of the compressor becomes the target rotation speed transmitted from the control unit via the communication unit, During the cooling operation, when a first communication abnormality occurs that is an abnormality related to communication from the compressor control unit to the communication unit and the compressor is operating, the control unit executes a first process of transmitting a preset first rotation speed to the communication unit as the target rotation speed, In the cooling storage facility, if the first communication abnormality occurs and the compressor is stopped during the cooling operation, the control unit stops the compressor until the measured temperature reaches an upper limit set temperature obtained by adding a first predetermined temperature to the target set temperature, and then, if the measured temperature becomes equal to or higher than the upper limit set temperature, executes a second process of sending the first rotation speed as the target rotation speed to the communication unit.

2. 2. The cooling storage facility of claim 1, wherein if a second communication abnormality, which is an abnormality related to communication from the communication unit to the compressor control unit, continues for a first predetermined time during the cooling operation and the compressor is operating, the compressor control unit operates the compressor at the rotation speed at the time the second communication abnormality occurred for a second predetermined time after the occurrence of the second communication abnormality, and then executes a third process to stop the compressor.

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