JP2018009729A - Cooling storage cabinet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling storage cabinet that can more accurately determine leakage of a refrigerant without being affected by a temperature in a storage chamber.SOLUTION: A cooling storage cabinet comprises: a storage cabinet body 11 including a storage chamber 12 and a cooler chamber 17; a compressor 22; a condenser 24; a cooler 30 arranged in the cooler chamber 17; a cooling fan 25 that sucks air in the storage chamber 12 into the cooler chamber 17, and supplies air passed through the cooler 30 into the storage chamber 12; an inflow port temperature sensor 35; a discharge port temperature sensor 36; and a control unit. When a temperature difference between a detected temperature of the discharge port temperature sensor 36 and a detected temperature of the inflow port temperature sensor 35 becomes equal to or higher than a predetermined value, the control unit executes stop processing for stopping driving of the cooling fan 25, and determination processing for determining whether a refrigerant is leaking on the basis of a temperature related to the cooler 30 after the stop processing.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cooling storage.

  Conventionally, what was described in the following patent document 1 is known as a cooling storage provided with a cooler. Japanese Patent Application Laid-Open No. H10-228667 describes a refrigerant leakage determination based on a temperature difference between a temperature sensor that detects the temperature of the refrigerant flowing into the cooler and a temperature sensor that detects the temperature of the refrigerant discharged from the cooler. Yes.

JP 2005-90953 A

  In the cooling storage, the storage room is cooled by circulating air between the cooler room and the storage room. For this reason, when the temperature in the storage chamber rises due to an increase in the internal load or the opening / closing of the door, the temperature of the temperature sensor for detecting the temperature of the cooler chamber and thus the cooler may rise. As a result, in the determination method for determining the leakage of the refrigerant based on the temperature difference between the two temperature sensors as in Patent Document 1, even if the refrigerant is not leaking, for example, the detected temperature of one temperature sensor As a result of the increase in temperature difference between the two temperature sensors, there is a concern that the refrigerant may erroneously determine that the refrigerant is leaking.

  The present invention has been completed based on the above circumstances, and provides a cooling storage that can more accurately determine refrigerant leakage by reducing the effect of temperature in the storage chamber. Objective.

  In order to solve the above-described problems, the cooling storage of the present invention includes a storage body and a storage body having a cooler chamber adjacent to the storage chamber, a compressor, a condenser, and the compressor and the condenser. A cooler that is circulated and arranged in the cooler chamber; and a cooling fan that sucks air in the storage chamber into the cooler chamber and supplies air that has passed through the cooler to the store chamber; An inlet temperature sensor that detects the temperature of the refrigerant inlet in the cooler, an outlet temperature sensor that detects the temperature of the refrigerant outlet in the cooler, and a control unit, the control unit comprising: , When the temperature difference between the detected temperature of the discharge port temperature sensor and the detected temperature of the inlet temperature sensor is equal to or greater than a predetermined value, after the stop process, to stop the driving of the cooling fan, Engage with the cooler Characterized in that the refrigerant based on the temperature executes a determination processing for determining whether or not leakage.

  When the refrigerant leaks, the amount of the refrigerant flowing into the cooler decreases, and the evaporation of the refrigerant may be completed in the middle of the refrigerant pipe of the cooler. At this time, the temperature is lowered by the evaporation of the refrigerant in the vicinity of the inlet of the cooler, but the temperature is difficult to decrease in the vicinity of the discharge port because the refrigerant does not evaporate. For this reason, when the temperature difference between the discharge port and the inflow port of the cooler is equal to or greater than a predetermined value, it can be estimated that the refrigerant is leaking.

  However, when the temperature in the storage chamber rises due to an increase in the load in the storage chamber or the influence of outside air (for example, opening and closing of the door), relatively high temperature air in the storage chamber is sucked into the cooler chamber by the cooling fan. As a result, the temperature around the cooler rises. As a result, the evaporation of the refrigerant in the cooler is promoted, so that it is conceivable that the evaporation of the refrigerant is completed in the middle of the refrigerant pipe of the cooler even though the refrigerant is not leaking. In such a case, even if the refrigerant is not leaking, a temperature difference between the inlet and the outlet of the cooler may occur, and there is a risk of erroneous determination that the refrigerant is leaking.

  Therefore, in the present invention, when the temperature difference between the detected temperature of the discharge port temperature sensor and the detected temperature of the inlet temperature sensor becomes a predetermined value or more, it is determined that there is a possibility of refrigerant leakage, and the cooling fan Stop driving. Thereafter, it is determined whether or not the refrigerant is leaking based on the temperature related to the cooler. By stopping the cooling fan, the situation in which the air in the storage chamber is sucked into the cooler chamber can be suppressed. For this reason, the situation which the temperature concerning a cooler changes due to the temperature in a storage room can be controlled, and it can be judged more correctly whether the refrigerant has leaked.

  Further, in the determination process, it is determined that the refrigerant is leaking when the temperature difference is equal to or greater than a predetermined value after a predetermined time has elapsed from the stop process. By stopping the driving of the cooling fan, it is possible to suppress the situation in which the detection temperature of the inlet temperature sensor and the outlet temperature sensor changes due to the influence of the temperature in the storage chamber, so it is possible to more accurately determine whether the refrigerant is leaking or not. Can be determined.

  Moreover, in order to solve the said subject, the cooling storehouse of this invention is the storehouse body which has a cooler room adjacent to the storeroom and the said storeroom in which a store thing is arranged, a compressor, a condenser, and the said A cooler that is circulated and connected to the compressor and the condenser and arranged in the cooler chamber, and sucks air in the storage chamber from a suction port provided below the cooler in the cooler chamber. And a cooling fan that supplies the air that has passed through the cooler into the storage chamber, a cooler temperature sensor that detects the temperature of the cooler, and the cooler and the suction port. An internal temperature sensor that detects the temperature of air from the mouth toward the cooler, and a control unit, wherein the control unit is a temperature detected by the internal temperature sensor and a temperature detected by the cooler temperature sensor. When the difference exceeds the specified value And a stop process for stopping the driving of the cooling fan, and a determination process for determining whether or not the refrigerant is leaking based on the temperature of the cooler after the stop process. Have.

  When the refrigerant leaks, the amount of the refrigerant flowing into the cooler is reduced and the cooling capacity is lowered. When the cooling capacity is lowered, the cooler is slightly cooled, while the temperature of the storage room having a large internal load is greatly increased. Thereby, the temperature rise of the storage chamber becomes larger than the temperature rise of the cooler, and the temperature difference between the detected temperature of the internal temperature sensor and the detected temperature of the cooler temperature sensor becomes larger. For this reason, when the temperature difference between the temperature detected by the internal temperature sensor and the temperature detected by the cooler temperature sensor is equal to or greater than a predetermined value, it can be determined that the refrigerant is leaking.

  However, only with the above determination, when the temperature in the storage chamber rises due to an increase in the internal load in the storage chamber or the influence of outside air (for example, opening and closing of the door), the detection temperature of the internal temperature sensor increases. There is a possibility that the temperature difference between the temperature detected by the internal temperature sensor and the temperature detected by the cooler temperature sensor becomes large, and even if the refrigerant is not leaking, it may be erroneously determined that the refrigerant is leaking. is there.

  Therefore, in the present invention, when the temperature difference between the temperature detected by the cooler temperature sensor and the temperature detected by the internal temperature sensor exceeds a predetermined value, it is determined that there is a possibility of refrigerant leakage, and the cooling fan is driven. Stop. Thereafter, it is determined whether or not the refrigerant is leaking based on the temperature related to the cooler. By stopping the cooling fan, the situation in which the air in the storage chamber is sucked into the cooler chamber can be suppressed. For this reason, the situation which the temperature concerning a cooler changes due to the temperature in a storage room can be controlled, and it can be judged more correctly whether the refrigerant has leaked.

  Moreover, in the said determination process, it can be determined whether the refrigerant | coolant has leaked based on the fall rate of the detected temperature of the said internal temperature sensor after the said stop process. By stopping the cooling fan, the cool air around the cooler descends, and the cool air touches the internal temperature sensor arranged between the cooler and the suction port. As a result, the temperature detected by the internal temperature sensor decreases. If the cooling capacity of the cooler is reduced due to refrigerant leakage, the temperature around the cooler will be higher than when the refrigerant is not leaking. The detection temperature of the sensor is difficult to decrease. For this reason, it can be determined whether the refrigerant is leaking based on the decreasing speed of the temperature detected by the internal temperature sensor.

  In addition, a condenser fan that air-cools the condenser may be provided, and the controller may operate the condenser fan when it is determined that the refrigerant is leaking in the determination process. Thereby, when the refrigerant is leaking in the vicinity of the condenser, the refrigerant can be diffused and diluted.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling storehouse which can determine more accurately the leakage of a refrigerant | coolant, without being influenced by the temperature in a storage chamber can be provided.

The perspective view of the cooling storehouse which concerns on Embodiment 1 of this invention. Sectional view showing the internal structure of the cooling storage Perspective view showing the cooler Exploded perspective view showing cooler Block diagram showing the electrical configuration of the cooling storage The flowchart which shows the process (refrigerant determination mode) of a control part. The flowchart which shows the process (refrigerant determination mode) of the control part which concerns on Embodiment 2. FIG.

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, a horizontal (table type) refrigerator is illustrated as a cooling storage. As shown in FIGS. 1 and 2, the cooling storage 10 includes a storage body 11 that is a horizontally long box. The storage body 11 is mainly composed of a metal plate such as a stainless steel plate and has a storage room 12 and a machine room 13. The storage chamber 12 has an opening at the front, and the opening can be opened and closed by a pair of double-split heat insulating doors 14 and 14. Thereby, it becomes the structure which can arrange | position a store thing in the storage chamber 12 through opening. Moreover, the storage body 11 is supported by four leg portions 15 provided on the bottom surface.

  The machine room 13 is provided on the side (left side) of the storage room 12. The machine room 13 is formed in a box shape with an open front, and can be opened and closed by a front panel 16. A cooling unit 20 is housed in the machine room 13 so that it can be pulled out. The cooling unit 20 includes a base 21, a compressor 22, a condenser fan 23, a condenser 24, a cooler 30, and a cooling fan 25. A box 18 constituting the cooler chamber 17 is disposed on the upper portion of the machine chamber 13.

  On the base 21, the compressor 22, the condenser fan 23, and the condenser 24 are mounted in order from the back side. A lid 19 that closes the opening of the box 18 from the front is attached to the upper surface of the condenser 24, and a cooler 30 is cantilevered on the back side of the lid 19. The cooler 30 can be inserted into the box 18 from the front. The condenser fan 23 is provided on the rear surface side of the condenser 24 and has a function of cooling the condenser 24 with air.

  As shown in FIGS. 3 and 4, the cooler 30 has a large number of fins 31 arranged side by side and end plates 32 </ b> A and 32 </ b> B arranged on both left and right sides thereof, and penetrates the fins 31 and the end plates 32 </ b> A and 32 </ b> B. The refrigerant pipe 34 is arranged in a meandering shape, and forms a block shape as a whole. In the present embodiment, for example, the inlet portion 34A of the refrigerant pipe 34 is disposed on the upper side, and the outlet portion 34B of the refrigerant pipe 34 is disposed on the lower side. However, the positional relationship between the inlet portion 34A and the outlet portion 34B is as follows. It is not limited and can be changed appropriately. In addition, the material of the component which comprises the cooler 30 is taken as the material with comparatively high heat conductivity, such as aluminum and copper, for example.

  The cooler 30 is circulated and connected to the compressor 22 and the condenser 24 via a pipe to constitute a refrigeration cycle. Specifically, the inlet 34A of the refrigerant pipe 34 is connected to the condenser 24 side in the refrigeration cycle, and the outlet 34B is connected to the compressor 22 side. As a result, the refrigerant that has flowed in from the inlet portion 34 </ b> A passes through the meandering portion of the refrigerant pipe 34, and then goes to the compressor 22 from the outlet portion 34 </ b> B. Further, between the condenser 24 and the cooler 30, a not-shown cabinet tube (or an expansion valve) is interposed. An inlet temperature sensor 35 that detects the temperature of the refrigerant inlet in the cooler 30 is attached to the inlet 34A. A discharge port temperature sensor 36 that detects the temperature of the refrigerant discharge port in the cooler 30 is attached to the outlet portion 34B.

  A pair of covers 37 and 38 made of a metal plate such as a stainless steel plate are attached to both the front and back surfaces of the cooler 30. A defrosting temperature sensor 41 (cooler temperature sensor) is attached to the upper end of the cover 38. The defrosting temperature sensor 41 is for determining that the defrosting is completed, and has a function of detecting the temperature of the cooler 30. A cooling fan 25 is attached to the top of the cover 37. A defrost heater 42 made of, for example, a glass tube heater is attached to the lower end portion of the cover 37. Further, as shown in FIG. 2, an internal temperature sensor 43 (internal chamber thermistor) for detecting the internal temperature is attached to the surface of the cover 37 opposite to the defrosting heater 42. The inlet temperature sensor 35, the discharge port temperature sensor 36, the defrosting temperature sensor 41, and the internal temperature sensor 43 are each a thermistor, for example. However, a temperature sensor (for example, a thermocouple) other than the thermistor may be used. Good.

  As shown in FIG. 2, the storage chamber 12 and the cooler chamber 17 are each formed of a heat insulating box and are partitioned by a partition plate 45. That is, the storage chamber 12 and the cooler chamber 17 are arranged adjacent to each other. An air outlet 46 that communicates between the storage chamber 12 and the cooler chamber 17 is provided at the upper portion of the partition plate 45, and a suction port 47 that communicates between the storage chamber 12 and the cooler chamber 17 at the lower portion of the partition plate 45. Is provided. The suction port 47 is disposed below the cooler 30, and the internal temperature sensor 43 is disposed between the cooler 30 and the suction port 47. Thereby, the internal temperature sensor 43 is configured to be able to detect the temperature of the air from the suction port 47 toward the cooler 30 (the temperature in the storage chamber 12). In addition, an electrical box 26 is provided on the front side of the lid 19. A control unit 50 to be described later is accommodated in the electrical box 26.

  Next, the electrical configuration of the cooling storage 10 will be described. As shown in FIG. 5, the cooling storage 10 includes a control unit 50. The control unit 50 includes a display unit 51, an operation unit 52, a storage unit 53, a timing unit 54, a compressor 22, a condenser fan 23, a cooling fan 25, a defrosting heater 42, an in-chamber temperature sensor 43, and a defrosting temperature. The sensor 41, the inlet temperature sensor 35, the discharge port temperature sensor 36, and the buzzer 55 are electrically connected.

  For example, the control unit 50 is configured mainly by a CPU, and the storage unit 53 is configured by, for example, a ROM, a RAM, or the like. The control unit 50 executes each computer program stored in the storage unit 53 to thereby connect each device (compressor 22, condenser fan 23, cooling fan 25, defrost heater 42, etc.) connected to the control unit 50. It is possible to control the operation.

  Moreover, the display part 51 and the operation part 52 are provided in the front surface of the electrical equipment box 26, for example. The display unit 51 is configured by, for example, a liquid crystal panel, and the operation unit 52 is configured by buttons that can be pressed. The operator can operate the cooling storage 10 and perform various settings (such as changing the set temperature in the storage) by operating the operation unit 52. Further, the time measuring unit 54 measures time. Moreover, the buzzer 55 is accommodated in the electrical equipment box 26, for example.

  Next, processing of the control unit 50 will be described. In the present embodiment, the cooling operation and the defrosting operation performed after the cooling operation are alternately performed. In addition, although a defrost operation is performed every several hours, for example, it is not limited to this. In the cooling operation, the control unit 50 drives the compressor 22, the condenser fan 23, and the cooling fan 25. As a result, as shown by the arrow in FIG. 2, the air in the storage chamber 12 is sucked into the cooler chamber 17 from the suction port 47 and passes through the cooler 30 to generate cold air. The inside of the storage chamber 12 is cooled by being circulated and supplied from 46 to the ceiling surface side of the storage chamber 12.

  In the cooling operation, the temperature in the storage chamber 12 is detected by the internal temperature sensor 43, and the compressor 22, the condenser fan 23, and the cooling fan 25 are turned on / off so that the detected temperature becomes a preset temperature. Be controlled. Specifically, the control unit 50 drives the compressor 22, the condenser fan 23, and the cooling fan 25 when the temperature detected by the internal temperature sensor 43 is higher than the set temperature, and detects the temperature detected by the internal temperature sensor 43. However, when the temperature is lower than the set temperature, the compressor 22 and the condenser fan 23 are stopped and the cooling fan 25 is driven. Thereby, the temperature in the storage chamber 12 is maintained substantially at the set temperature.

  In the defrosting operation, the control unit 50 is performed by energizing the defrosting heater 42 and heating the cooler 30 while the operation of the compressor 22 and the cooling fan 25 is stopped. Is received by a tray (not shown) disposed on the inner bottom surface of the cooler chamber 17 and then drained out of the cabinet through a drainage channel (not shown). Further, in the defrosting operation, the defrosting temperature sensor 41 detects the temperature of the cooler 30, and when the detected temperature of the defrosting temperature sensor 41 reaches a predetermined value, it is considered that the defrosting is completed and the temperature is removed. The frost operation is finished and the cooling operation is resumed.

  Moreover, the control part 50 performs the process (refrigerant determination mode) which stops a cooling operation and determines the leakage of a refrigerant | coolant, when predetermined conditions (after-mentioned) are satisfy | filled during a cooling operation. The refrigerant determination mode in the present embodiment includes steps S10 to S70 as shown in FIG. During the cooling operation, the control unit 50 determines that the difference between the detected temperature of the discharge port temperature sensor 36 and the detected temperature of the inlet temperature sensor 35 is equal to or greater than a predetermined value DT1 (first predetermined value) (YES in S10). The cooling fan 25 is stopped (S20, stop process). In the refrigerant determination mode, the compressor 22 and the condenser fan 23 are basically controlled in the same manner as in the cooling operation. That is, the cooler 30 is in a state where the cooling capacity is exhibited.

  Next, the controller 50 waits for a predetermined time T4 (S30), and then the difference between the detected temperature of the discharge port temperature sensor 36 and the detected temperature of the inlet temperature sensor 35 is equal to or greater than a predetermined value DT2 (second predetermined value). It is determined whether or not (S40), and if it is equal to or greater than the predetermined value DT2, it is determined that the refrigerant is leaking (determination process). When the control unit 50 determines that the refrigerant is leaking (YES in S40), for example, a wording indicating that the refrigerant is leaked to the display unit 51 (“There is a possibility that the refrigerant is leaking” or the like). (S50, notification process). In the notification process, the user may be notified that the refrigerant is leaking by sounding the buzzer 55, and the display of the display unit 51 and the sounding of the buzzer 55 may be performed simultaneously. Here, as described above, the discharge port temperature sensor 36 and the inflow port temperature sensor 35 detect the temperature related to the cooler 30. For this reason, the determination process is a process of determining whether or not the refrigerant is leaking based on the temperature related to the cooler 30.

  When it is determined that the refrigerant is leaking, the control unit 50 always operates the condenser fan 23 regardless of the temperature detected by the internal temperature sensor 43 (S60). Thereby, when the refrigerant is leaking in the vicinity of the condenser 24, the refrigerant can be diffused and diluted, and a situation in which the refrigerant is accumulated in the machine chamber 13 can be suppressed. In addition, when it is determined that the refrigerant has not leaked (NO in S40), the control unit 50 operates the cooling fan 25 and executes a cooling operation (S70). The predetermined values DT1 and DT2 and the predetermined time T4 described above are values that are appropriately determined in advance by a test or the like, and are stored in the storage unit 53. The predetermined value DT1 and the predetermined value DT2 are set to the same value, for example, but may be set to different values.

  Next, the effect of this embodiment will be described. In the present embodiment, when the refrigerant leaks, the amount of the refrigerant flowing into the cooler 30 is decreased, and the evaporation of the refrigerant may be completed in the middle of the refrigerant pipe of the cooler 30. In this case, the temperature of the cooler 30 near the inlet 34A (inlet) decreases due to the evaporation of the refrigerant, whereas the refrigerant does not evaporate near the outlet 34B (discharge port), so the temperature is difficult to decrease. For this reason, when the temperature difference between the discharge port and the inflow port of the cooler 30 becomes equal to or greater than a predetermined value, it can be estimated that the refrigerant is leaking.

  However, when the temperature in the storage chamber 12 rises due to an increase in the internal load in the storage chamber 12 or the influence of outside air (for example, opening and closing of the door 14), the air having a relatively high temperature in the storage chamber 12 is cooled. By being sucked into the cooler chamber 17 by the fan 25, the temperature around the cooler 30 rises. As a result, by promoting the evaporation of the refrigerant in the cooler 30, it is conceivable that the evaporation of the refrigerant is completed in the middle of the refrigerant pipe of the cooler 30 even though the refrigerant is not leaking. In such a case, even if the refrigerant is not leaking, a temperature difference between the inlet and the outlet of the cooler 30 may occur, and there is a risk of erroneous determination that the refrigerant is leaking.

  Therefore, in this embodiment, when the temperature difference between the detected temperature of the discharge port temperature sensor 36 and the detected temperature of the inlet temperature sensor 35 is equal to or greater than a predetermined value DT1, it is determined that there is a possibility of refrigerant leakage. Then, the driving of the cooling fan 25 is stopped. Then, when the temperature difference is equal to or greater than the predetermined value DT2 after a predetermined time has elapsed, a process for determining that the refrigerant is leaking is performed. By stopping the cooling fan 25, it is possible to suppress a situation in which the air in the storage chamber 12 is sucked into the cooler chamber 17. Thereby, since the situation where the detection temperature of the inflow port temperature sensor 35 and the discharge port temperature sensor 36 changes under the influence of the temperature in the storage chamber 12 can be suppressed, it is more accurately determined whether or not the refrigerant is leaking. Can do.

  In addition, as a method of determining the leakage of the refrigerant, for example, a refrigerant sensor that directly detects the refrigerant may be used. However, in the method using the refrigerant sensor, it is difficult to detect the refrigerant when the refrigerant leaks at a location far from the refrigerant sensor. In the determination method of the present embodiment, it is possible to determine refrigerant leakage regardless of where the refrigerant leakage occurs in the refrigeration cycle.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. In the present embodiment, the processing in the refrigerant determination mode in the control unit 50 is different from the above embodiment. Note that the same portions as those in the above embodiment are denoted by the same reference numerals and redundant description is omitted. The refrigerant determination mode in the present embodiment includes steps S110 to S170 as shown in FIG. The controller 50 stops the cooling fan 25 when the difference between the temperature detected by the internal temperature sensor 43 and the temperature detected by the defrosting temperature sensor 41 is equal to or greater than a predetermined value DT3 (YES in S110) during the cooling operation. (S120, stop process). By stopping the cooling fan 25, the cool air around the cooler 30 is lowered, and the cool air touches the internal temperature sensor 43 disposed between the cooler 30 and the suction port 47. As a result, the temperature detected by the internal temperature sensor 43 decreases.

  Next, after waiting for a predetermined time T3 (S130), the controller 50 determines whether or not the temperature decrease rate V1 of the internal temperature sensor 43 is equal to or lower than a predetermined value DT4 (S140). When it is DT4 or less, it is determined that the refrigerant is leaking (determination process). That is, in this embodiment, it is determined whether the refrigerant is leaking based on the rate of decrease in the temperature detected by the internal temperature sensor 43 after the stop process. As described above, the temperature detected by the internal temperature sensor 43 after the stop process is a temperature caused by the temperature of the cool air around the cooler 30. For this reason, the temperature detected by the internal temperature sensor 43 after the stop process is the temperature related to the cooler 30, and the determination process determines whether the refrigerant is leaking based on the temperature related to the cooler 30. It is processing to do.

  Specifically, the “decrease rate V1 of the detected temperature of the internal temperature sensor 43” specifically refers to the detected temperature T2 of the internal temperature sensor 43 before the elapse of a predetermined time T3 (immediately after the cooling fan 25 is stopped), This is a value obtained by dividing the difference from the detected temperature T1 of the internal temperature sensor 43 after the elapse of the predetermined time T3 by the predetermined time T3. For example, when the detected temperature of the internal temperature sensor 43 decreases from 5 ° C. to 3 ° C. within 2 minutes after the cooling fan 25 stops, the detected temperature T 2 is 5 ° C., the detected temperature T 1 is 3 ° C., and the predetermined time T 3 is 2 Minutes, and the decrease rate V1 is 1 ° C./min.

  The low decrease rate V1 means that the cooling capacity of the cooler 30 is reduced as a result of refrigerant leakage, and the temperature of the cool air around the cooler 30 is relatively high. This means that the temperature drop of the internal temperature sensor 43 is small. For this reason, when the decrease rate V1 is equal to or less than the predetermined value DT4, it can be determined that the refrigerant is leaking. The predetermined values DT3 and DT4 and the predetermined time T3 described above are values that are appropriately determined in advance by a test or the like, and are stored in the storage unit 53.

  When it is determined that the refrigerant is leaking (YES in S140), the control unit 50 displays, for example, a word indicating the refrigerant leakage on the display unit 51 as in the first embodiment (S150, notification). processing). In the notification process, the user may be notified that the refrigerant is leaking by sounding the buzzer 55, and the display of the display unit 51 and the sounding of the buzzer 55 may be performed simultaneously. When it is determined that the refrigerant is leaking, the control unit 50 always operates the condenser fan 23 regardless of the temperature detected by the internal temperature sensor 43 (S160). In addition, when it is determined that the refrigerant has not leaked (NO in S140), the control unit 50 operates the cooling fan 25 and executes the cooling operation (S170).

  Next, the effect of this embodiment will be described. When the refrigerant leaks, the amount of the refrigerant flowing into the cooler 30 is reduced and the cooling capacity is lowered. When the cooling capacity is lowered, the cooler 30 is slightly cooled, while the temperature of the storage room 12 having a large internal load is greatly increased. Thereby, the temperature rise of the storage chamber 12 becomes larger than the temperature rise of the cooler 30, and the temperature difference between the temperature detected by the internal temperature sensor 43 and the temperature detected by the defrosting temperature sensor 41 increases. For this reason, when the temperature difference between the temperature detected by the internal temperature sensor 43 and the temperature detected by the defrosting temperature sensor 41 is equal to or greater than a predetermined value, it can be determined that the refrigerant is leaking.

  However, only by the above determination, when the temperature in the storage chamber 12 rises due to an increase in the internal load in the storage chamber 12 or the influence of outside air (for example, opening and closing of the door 14), the temperature detected by the internal temperature sensor 43 is detected. As a result, the temperature difference between the temperature detected by the internal temperature sensor 43 and the temperature detected by the defrosting temperature sensor 41 becomes large, and the refrigerant is leaking even when the refrigerant is not leaking. May be misjudged.

  Therefore, in the present embodiment, when the temperature difference between the temperature detected by the defrosting temperature sensor 41 and the temperature detected by the internal temperature sensor 43 exceeds a predetermined value (S110), there is a possibility of refrigerant leakage. Judgment is made and the driving of the cooling fan 25 is stopped. Thereby, the situation where the air in the storage chamber 12 is sucked into the cooler chamber 17 is suppressed, and the internal temperature sensor 43 is hardly affected by the temperature of the storage chamber 12. Further, by stopping the cooling fan 25, the cool air around the cooler 30 is lowered, and the cool air touches the inside temperature sensor 43 disposed between the cooler 30 and the suction port 47. As a result, the temperature detected by the internal temperature sensor 43 decreases.

  If the cooling capacity of the cooler 30 is reduced due to the leakage of the refrigerant, the temperature around the cooler 30 is higher than when the refrigerant is not leaking. It is difficult for the temperature detected by the internal temperature sensor 43 to decrease (the rate of decrease is small). For this reason, it can be determined whether the refrigerant is leaking based on the rate of decrease in the temperature detected by the internal temperature sensor 43. Thus, in this embodiment, after the cooling fan 25 is stopped, the influence of the temperature in the storage chamber 12 can be reduced by determining the leakage of the refrigerant, and whether or not the refrigerant is leaking. Can be determined more accurately.

  In the present embodiment, the refrigerant leakage can be determined using the internal temperature sensor 43 and the defrosting temperature sensor 41. For this reason, the inlet temperature sensor 35 and the outlet temperature sensor 36 can be eliminated. In this embodiment, when the cooling fan 25 is stopped, the cool air around the cooler 30 is lowered and the cool air touches the internal temperature sensor 43, so that the cooling capacity of the cooler 30 is improved. A drop (and consequently a refrigerant leak) is detected. For this reason, in this embodiment, when the cool air around the cooler 30 is lowered, the internal temperature sensor 43 needs to be installed at a location where the cool air touches. When there is a situation where the internal temperature sensor 43 cannot be installed at such a location, the refrigerant leakage is determined using the temperature difference between the inlet temperature sensor 35 and the outlet temperature sensor 36 as in the first embodiment. do it.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the cooler chamber 17 is disposed on the side of the storage chamber 12, but the present invention is not limited to this. For example, the cooler chamber 17 may be disposed above the storage chamber 12.
(2) The installation location of the internal temperature sensor 43 is not limited to the location exemplified in the above embodiment.
For example, as indicated by a one-dot chain line in FIG. 2, an internal temperature sensor (denoted by reference numeral 43 </ b> A) may be disposed immediately below the cooler 30.
(3) In the said embodiment, the defrost heater 42 is not limited to a glass tube heater, For example, a sheathed heater etc. may be used.
(4) Words displayed on the display unit 51 in the notification process are not limited to those exemplified in the above embodiment. For example, an error number assigned corresponding to the leakage of the refrigerant may be displayed on the display unit 51.
(5) The stop process and the determination process exemplified in the above embodiments can be used in appropriate combination. For example, the leakage of the refrigerant may be determined by performing the determination process of the second embodiment after the stop process of the first embodiment, and the determination process of the first embodiment is performed after the stop process of the second embodiment. Thus, the leakage of the refrigerant may be determined.

DESCRIPTION OF SYMBOLS 10 ... Cooling storage, 11 ... Storage body, 12 ... Storage room, 17 ... Cooler room, 22 ... Compressor, 24 ... Condenser, 25 ... Cooling fan, 30 ... Cooler, 35 ... Inlet temperature sensor, 36 ... Discharge port temperature sensor, 41 ... defrosting temperature sensor (cooler temperature sensor), 43 ... internal temperature sensor, 47 ... suction port, 50 ... control unit

Claims (5)

A storage body having a storage room in which stored items are arranged and a cooler room adjacent to the storage room;
A compressor,
A condenser,
A cooler circulatingly connected to the compressor and the condenser and disposed in the cooler chamber;
A cooling fan that sucks air in the storage chamber into the cooler chamber and supplies air that has passed through the cooler to the storage chamber;
An inlet temperature sensor for detecting the temperature of the refrigerant inlet in the cooler;
An outlet temperature sensor for detecting the temperature of the refrigerant outlet in the cooler;
A control unit,
The controller is
A stop process for stopping the driving of the cooling fan when the temperature difference between the detected temperature of the discharge port temperature sensor and the detected temperature of the inlet temperature sensor becomes a predetermined value or more;
A cooling storage that executes, after the stop process, a determination process for determining whether or not the refrigerant is leaking based on a temperature related to the cooler. In the determination process,
The cooling storage according to claim 1, wherein after a predetermined time has elapsed from the stop process, it is determined that the refrigerant is leaking when the temperature difference is equal to or greater than a predetermined value. A storage body having a storage room in which stored items are arranged and a cooler room adjacent to the storage room;
A compressor,
A condenser,
A cooler circulatingly connected to the compressor and the condenser and disposed in the cooler chamber;
A cooling fan that sucks air in the storage chamber from a suction port provided below the cooler in the cooler chamber and supplies air that has passed through the cooler to the storage chamber;
A cooler temperature sensor for detecting the temperature of the cooler;
An internal temperature sensor that is arranged between the cooler and the suction port and detects the temperature of air from the suction port toward the cooler;
A control unit,
The controller is
When the temperature difference between the detected temperature of the internal temperature sensor and the detected temperature of the cooler temperature sensor is equal to or greater than a predetermined value, a stop process for stopping the driving of the cooling fan;
A cooling storage that executes, after the stop process, a determination process for determining whether or not the refrigerant is leaking based on a temperature related to the cooler.   The cooling storage according to claim 3, wherein in the determination process, it is determined whether or not the refrigerant is leaked based on a rate of decrease in temperature detected by the internal temperature sensor after the stop process. A condenser fan for air-cooling the condenser;
The cooling storage according to any one of claims 1 to 4, wherein when the control unit determines that the refrigerant is leaked in the determination process, the control unit operates the condenser fan.

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