Cooling device

Abstract

In a cooling system that connects a cooling cabinet and a display case, the display compartment is kept well-cooled even while the cooler inside the display case is being defrosted. [Solution] Inside the case body 10 of the display case 1, a display room 12 for displaying items to be cooled, a first ceiling duct 16 housing a cooler 37, and a second ceiling duct 17 separated from the first ceiling duct 16 by a partition wall 15 are partitioned. The rear ends of the first ceiling duct 16 and the second ceiling duct 17 are connected to the cooling room 6 of the cooling cabinet 2 which is cooled by the cooling means 7, and the front ends of the first ceiling duct 16 and the second ceiling duct 17 are provided with air outlets 21 and 22 facing the front opening of the case body 10. In the defrosting mode in which the cooler 37 is heated by the defrosting means 47, the first fan 31 corresponding to the first ceiling duct 16 is stopped and the second fan 32 corresponding to the second ceiling duct 17 is driven.

Description

[Technical Field]

[0001] The present invention relates to a cooling device formed by connecting a cooler and a display case. [Background Art]

[0002] For example, Patent Document 1 discloses a cooling device formed by connecting a prefabricated refrigerator for storing spare articles to be cooled to the back side of an open showcase for displaying articles to be cooled. The interior of the showcase and the interior of the refrigerator communicate in the front-rear direction, and a cooler for cooling air is provided respectively in the showcase and the refrigerator. A blower fan for taking in cool air from the refrigerator is provided at the opening on the back side of the showcase, and the cool air taken into the showcase by this blower fan is further cooled by the cooler in the showcase.

[0003] Specifically, the interior of the open showcase is divided into a display chamber in which shelf boards are installed in a multi-stage vertical arrangement, a ceiling duct above the display chamber, and an underfloor duct below the display chamber. A downward air outlet is provided at the front end of the ceiling duct, and an upward air inlet is provided at the front end of the underfloor duct. The aforementioned cooler is housed in the ceiling duct, and a blower fan is arranged behind the cooler. In addition, the underfloor duct is provided with a suction fan for sucking cool air from the air inlet. When the suction fan and the blower fan are driven, cool air cooled by the cooler in the ceiling duct is blown downward from the air outlet to the air inlet, and an air curtain of cool air is formed on the front surface of the display chamber. This air curtain cools the inside of the display chamber and blocks outside air from entering the display chamber. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2000-213852 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] As described above, the entry of outside air into the display room of an open showcase is blocked by an air curtain at the front. However, if the air curtain is disturbed, for example, when a shopper picks up a product (a product to be cooled) inside the display room, it is unavoidable that outside air will enter through that point. The water vapor contained in this outside air is cooled mainly around the cooler and condenses as frost. This frost reduces the heat exchange efficiency between the cooler and the air, so it is desirable to defrost the cooler regularly.

[0006] Generally, defrosting of a cooler is performed by heating the cooler with a heater or the like. In the cooling device of Patent Document 1, when defrosting is performed by heating the cooler inside the ceiling duct of a showcase, it is desirable to stop the blower fan at the rear of the cooler during heating. This is to suppress the outflow of warm air generated by heating into the display room and to trap the warm air in the ceiling duct to promote the melting of frost. However, this blower fan is responsible for forming an air curtain at the front of the display room and supplying cold air from the prefabricated refrigerator to the showcase. Therefore, if the blower fan is stopped, the air curtain disappears, making it easier for outside air to enter the display room, and the inflow of cold air from the refrigerator to the showcase becomes limited, which are factors that cause the temperature of the display room to rise.

[0007] The object of the present invention is to provide a cooling device that connects a cooling cabinet and a display case, which can maintain good cooling of the display compartment even while the cooler inside the display case is being defrosted. [Means for solving the problem]

[0008] The present invention relates to a cooling device comprising a cooling cabinet 2 and a display case 1. The cooling cabinet 2 includes a cooling chamber 6 that is cooled by a cooling means 7. The display case 1 includes a case body 10 having openings on its front and rear surfaces, a cooler 37 for cooling the air inside the case body 10, a defrosting means 47 for heating the cooler 37, a blower 30 that forms an air curtain along the front opening of the case body 10, and a control unit that controls the defrosting means 47 and the blower 30. Inside the case body 10, there is a display chamber 12 for displaying items to be cooled, a first ceiling duct 16 housing the cooler 37, and a second ceiling duct 17 separated from the first ceiling duct 16 by a partition wall 15. The rear ends of the first ceiling duct 16 and the second ceiling duct 17 are connected to the cooling chamber 6, and the front ends of the first ceiling duct 16 and the second ceiling duct 17 are provided with downward-facing outlets 21 and 22 facing the front opening of the case body 10. The air blowing means 30 includes a first fan 31 for taking in air from the cooling chamber 6 into the first ceiling duct 16 and blowing it out from the outlet 21, and a second fan 32 for taking in air from the cooling chamber 6 into the second ceiling duct 17 and blowing it out from the outlet 22. The control unit is characterized in that, in the defrosting mode in which the defrosting means 47 heats the cooler 37, it stops the first fan 31 and drives the second fan 32.

[0009] An external duct 18 is provided on the outer side of the case body 10, and an external outlet 23 is provided at the lower end of the external duct 18, opening downward in front of the outlet 22 of the second ceiling duct 17. The air blowing means 30 includes a third fan 33 for taking in air from outside the display case 1 into the external duct 18 and blowing it out from the external outlet 23. In defrost mode, the control unit drives the third fan 33 in addition to the second fan 32.

[0010] The display case 1 has three operating modes: a strong cooling mode in which the refrigerant liquefied by the condensing unit 38 is supplied to the cooler 37; a weak cooling mode in which the supply of the refrigerant is stopped; and a defrosting mode in which the supply of the refrigerant is stopped and the cooler 37 is heated by the defrosting means 47. In the strong cooling mode and the weak cooling mode, the control unit drives the first fan 31 and the second fan 32. [Effects of the Invention]

[0011] The display case 1 of the cooling device according to the present invention has a case body 10 which contains a display room 12 for displaying items to be cooled, a first ceiling duct 16 for housing a cooler 37, and a second ceiling duct 17 separated from the first ceiling duct 16 by a partition wall 15. The rear ends of the first ceiling duct 16 and the second ceiling duct 17 are connected to the cooling room 6 of the cooling cabinet 2 which is cooled by the cooling means 7, and the front ends of the first ceiling duct 16 and the second ceiling duct 17 are provided with air outlets 21 and 22 facing the front opening of the case body 10. In the present invention, in the defrosting mode in which the cooler 37 is heated by the defrosting means 47, the first fan 31 corresponding to the first ceiling duct 16 is stopped and the second fan 32 corresponding to the second ceiling duct 17 is driven.

[0012] As described above, the cooler 37 is housed in the first ceiling duct 16. Stopping the first fan 31 during defrosting of the cooler 37 suppresses the outflow of warm air generated by heating from the first ceiling duct 16 into the display room 12, and also traps the warm air in the first ceiling duct 16, promoting the melting of frost attached to the cooler 37. Furthermore, driving the second fan 32 during defrosting of the cooler 37 forms an air curtain in front of the display room 12 from the outlet 22 of the second ceiling duct 17, blocking the intrusion of outside air into the display room 12. Since this air curtain is formed by the low-temperature air of the cooling room 6 cooled by the cooling means 7, it exhibits the effect of keeping the display room 12 cool. As described above, according to the present invention, even during defrosting of the cooler 37 in the display case 1, the display room 12 can be kept cool with a low-temperature air curtain without reducing its efficiency.

[0013] An external duct 18 is provided on the outer side of the case body 10, and an external outlet 23 is provided at the lower end of this external duct 18, opening downward in front of the outlet 22 of the second ceiling duct 17. During defrosting of the cooler 37, a third fan 33 corresponding to the external duct 18 is driven in addition to the second fan 32 corresponding to the second ceiling duct 17. With this configuration, ambient temperature air from outside the case is blown out from the external duct 18, forming an ambient temperature air curtain on the outside (front) of the low-temperature air curtain formed from the second ceiling duct 17. This ambient temperature air curtain prevents turbulence in the low-temperature air curtain, thereby allowing the display room 12 to be kept cooler more effectively during defrosting of the cooler 37.

[0014] In addition to the strong cooling mode, which supplies liquefied refrigerant from the condensing unit 38 to the cooler 37 inside the display case 1, if a weak cooling mode is set to stop the supply of the refrigerant, the power consumption of the condensing unit 38 can be reduced by switching from the strong cooling mode to the weak cooling mode during times when it is not necessary to strongly cool the items to be cooled, such as outside of business hours at the store where the cooling device is installed. Even in weak cooling mode, the first fan 31 and the second fan 32 are driven, so that the low-temperature air from the cooling chamber 6 is drawn into the display case 1, and the display chamber 12 can be adequately cooled. Furthermore, in weak cooling mode, if the first fan 31 corresponding to the first ceiling duct 16 is driven, air can be blown onto the frost that has accumulated on the cooler 37 during the strong cooling mode, promoting the melting of the frost. [Brief explanation of the drawing]

[0015] [Figure 1] A longitudinal cross-sectional side view showing the overall configuration of a cooling device according to an embodiment of the present invention. [Figure 2] This is a diagram illustrating the configuration of the refrigeration cycle of a cooling system. [Figure 3] This is a timing chart showing the operation of the cooling system. [Modes for carrying out the invention]

[0016] (Embodiment) Figures 1 to 3 show an embodiment in which the cooling device according to the present invention is applied to a walk-in refrigerated display case installed in a retail store such as a supermarket. As shown in Figure 1, the walk-in refrigerated display case is constructed by connecting a prefabricated cooling cabinet 2, which is accessible to store employees, to the back of an open display case 1 in which refrigerated goods (items to be cooled).

[0017] The cooler 2 comprises a main body 4 made of an insulated enclosure with openings formed on the front and sides, a door 5 that opens and closes the side opening of the main body 4, i.e., the entrance for store employees, a cooling chamber 6 enclosed by the main body 4 and the door 5, and a cooling means 7 that cools the air in the cooling chamber 6 to a refrigeration temperature. The front opening of the main body 4 communicates with the display case 1. The cooling means 7 consists of a unit cooler installed on the ceiling of the cooling chamber 6, and the cooling chamber 6 stores spare refrigerated products before they are displayed in the display case 1. Store employees who enter the cooling chamber 6 can place the spare refrigerated products into the display case 1 from the rear through the front opening of the main body 4.

[0018] Display case 1 is constructed with a case body 10 that is roughly rectangular in shape and has openings on its front and rear surfaces. The front opening of the case body 10 faces the sales floor inside the store, and the rear opening of the case body 10 communicates with the cooling chamber 6. The interior of the case body 10 is divided into a display chamber 12 in which shelves 11 for displaying refrigerated products are installed in multiple tiers, a ceiling duct 13 above the display chamber 12, and an underfloor duct 14 below the display chamber 12. The ceiling duct 13 is divided into a lower first ceiling duct 16 and an upper second ceiling duct 17 by a roughly horizontal partition wall 15. Outside the ceiling duct 13, an external duct 18 is provided that extends vertically along the outer surface of the case body 10.

[0019] Downward-facing air outlets 21 to 23 facing the front opening of the case body 10 are provided at the front ends of the first ceiling duct 16, the second ceiling duct 17 and the lower end of the external duct 18. Specifically, the second air outlet 22 at the front end of the second ceiling duct 17 is arranged on the front side of the first air outlet 21 at the front end of the first ceiling duct 16, and the external air outlet 23 at the lower end of the external duct 18 is further arranged on the front side of the second air outlet 22. The rear ends of the first ceiling duct 16 and the second ceiling duct 17 communicate with the upper part of the cooling compartment 6, and the upper end of the external duct 18 opens toward outside air (air inside the store). On the other hand, an upward-facing suction inlet 24 facing each of the air outlets 21 to 23 is provided at the front end of the underfloor duct 14. The rear end of the underfloor duct 14 communicates with the lower part of the cooling compartment 6.

[0020] A downward air curtain is formed between each of the air outlets 21 to 23 and the suction inlet 24 by the air blowing means 30. The air blowing means 30 includes a first fan 31 arranged at the rear end of the first ceiling duct 16, a second fan 32 arranged at the rear end of the second ceiling duct 17, a third fan 33 arranged at the upper end of the external duct 18, and a suction fan 34 arranged in the underfloor duct 14. The first fan 31 takes in air from the cooling compartment 6 through the rear end of the first ceiling duct 16, and blows the air downward through the first air outlet 21 at the front end of the first ceiling duct 16. Similarly, the second fan 32 takes in air from the cooling compartment 6 through the rear end of the second ceiling duct 17, and blows the air downward through the second air outlet 22 at the front end of the second ceiling duct 17. The third fan 33 takes in outside air through the upper end of the external duct 18, and blows the air downward through the third air outlet 23 at the lower end of the external duct 18. The suction fan 34 takes in air through the suction inlet 24 at the front end of the underfloor duct 14, and recirculates the air to the cooling compartment 6 from the rear end of the underfloor duct 14.

[0021] When all of the fans 31 to 34 constituting the air blowing means 30 are driven, inner and outer three-layered air curtains arranged in front-rear order are formed on the front face of the display chamber 12, thereby blocking outside air from entering the display chamber 12. The first-layer air curtain blown out from the first air outlet 21 and the second-layer air curtain blown out from the second air outlet 22 are formed of low-temperature air in the cooling chamber 6 cooled by the cooling means 7 of the refrigerator 2, and therefore exhibit the effect of keeping the display chamber 12 cold. The third-layer air curtain blown out from the outer air outlet 23 is formed of normal-temperature outside air, and prevents turbulence of the first-layer and second-layer air curtains.

[0022] A cooler 37 for further cooling the air in the cooling chamber 6 taken in by the first fan 31 is provided in front of the first fan 31 in the first ceiling duct 16. When this cooler 37 is operated, the temperature of the first-layer air curtain blown out from the first air outlet 21 becomes even lower than that of the second-layer air curtain blown out from the second air outlet 22, whereby the display chamber 12 is cooled to a temperature lower than that of the cooling chamber 6.

[0023] As shown in Figure 2, the cooler 37 is connected via a refrigerant pipe to a condensing unit 38 installed outside the store. The condensing unit 38 includes a compressor 39 that compresses gaseous refrigerant, and a condenser 40 that air-cools and condenses the refrigerant compressed by the compressor 39. The cooler 37 and an evaporator 41 of the cooling means 7 (unit cooler) are connected in parallel on the downstream side of the condensing unit 38. An expansion valve 42 for depressurizing the refrigerant liquefied by the condenser 40 is provided between a branch point on the downstream side of the condensing unit 38 and the evaporator 41, and an electromagnetic valve 44 for opening and closing the refrigerant pipe is provided in addition to a similar expansion valve 43 between the branch point and the cooler 37. When this electromagnetic valve 44 is opened, the refrigerant liquefied by the condensing unit 38 is depressurized by the expansion valve 43 and then supplied to the cooler 37, whereby the air around the cooler 37 can be cooled.

[0024] As described above, the air curtain in front of display case 1 is effective in blocking the intrusion of outside air into the display room 12. However, if the air curtain is disturbed, for example by a shopper picking up a refrigerated product in the display room 12, outside air cannot be avoided. The water vapor contained in this outside air is cooled mainly around the cooler 37 and adheres as frost, reducing the heat exchange efficiency between the cooler 37 and the air. To remove this frost, that is, to heat and melt it, a defrosting means 47 consisting of an electric heater is attached along the bottom surface of the cooler 37.

[0025] The control unit of the display case 1 controls the blower 30, defrosting means 47, and solenoid valve 44, and selectively executes one of the following modes: strong cooling mode, weak cooling mode, or defrosting mode. First, the strong cooling mode is an operating mode that cools the display room 12 to a temperature lower than that of the cooling room 6, and this strong cooling mode is mainly selected during store operating hours. In strong cooling mode, as shown in the timing chart of Figure 3, the control unit opens the solenoid valve 44 to supply refrigerant from the condensing unit 38 to the cooler 37, and also drives all the fans 31 to 34 that make up the blower 30. Three layers of air curtains are formed in front of the display room 12, and the innermost first layer of air curtain is formed of cold air that has been further cooled around the cooler 37 from the air in the cooling room 6.

[0026] When a predetermined time has elapsed since the start of the strong cooling mode, or when the amount of frost on the cooler 37 detected by any sensor exceeds a predetermined level, the display case 1 switches from the strong cooling mode to the defrosting mode. In the defrosting mode, the control unit closes the solenoid valve 44 to stop the supply of refrigerant from the condensing unit 38 to the cooler 37, and then energizes the defrosting means 47 to heat the cooler 37. In addition, the first fan 31 of the blowing means 30 is stopped, and only the second fan 32, the third fan 33, and the intake fan 34 are driven. When a predetermined time has elapsed since the start of the defrosting mode, or when the amount of frost on the cooler 37 detected by any sensor falls below a predetermined level, the control unit returns the display case 1 from the defrosting mode to the strong cooling mode.

[0027] In defrost mode, stopping the first fan 31 suppresses the outflow of warm air generated by heating from the first ceiling duct 16 into the display room 12, and also traps the warm air in the first ceiling duct 16, promoting the melting of frost attached to the cooler 37. Furthermore, driving the second fan 32 and the third fan 33 forms a two-layer air curtain in front of the display room 12 from the outlets 22 and 23 of the second ceiling duct 17 and the external duct 18, blocking the intrusion of outside air into the display room 12. The inner air curtain formed from the second outlet 22 is formed with the low-temperature air of the cooling room 6 cooled by the cooling means 7, and therefore has the effect of keeping the display room 12 cool. The outer air curtain formed from the outer outlet 23 prevents turbulence in the inner low-temperature air curtain, thereby enhancing the cooling effect of the air curtain. Thus, in the defrost mode of this embodiment, the display room 12 can be kept cool without reducing the defrost efficiency of the cooler 37.

[0028] When the store closes for the day and a store employee attaches the night cover 50 (see Figure 1) to the front of the display room 12, the display case 1 switches from strong cooling mode to weak cooling mode. In weak cooling mode, the control unit closes the solenoid valve 44 to stop the supply of refrigerant from the condensing unit 38 to the cooler 37. In addition, the third fan 33 of the blowing means 30 is stopped, and only the first fan 31, the second fan 32, and the intake fan 34 are driven. The third fan 33 is stopped because if the front of the display room 12 is covered with the night cover 50, the ambient temperature air curtain that prevents disturbance of the low-temperature air curtain is unnecessary. Subsequently, for example, when the store opens for the next day and the night cover 50 is removed from the front of the display room 12, the control unit returns the display case 1 from weak cooling mode to strong cooling mode.

[0029] Switching the display case 1 from strong cooling mode to weak cooling mode reduces the load on the condensing unit 38 by stopping the supply of refrigerant to the cooler 37, thereby reducing its power consumption. Even in weak cooling mode, the first fan 31 and the second fan 32 are driven, so that the cold air from the cooling chamber 6 is drawn into the display case 1, and the display chamber 12 can be adequately cooled. In addition, in weak cooling mode, driving the first fan 31 corresponding to the first ceiling duct 16 blows air onto the frost that has accumulated on the cooler 37 during the strong cooling mode, promoting the melting of the frost. In this way, reducing the volume of frost on the cooler 37 in weak cooling mode allows the defrosting mode to be omitted or its duration shortened, thereby reducing the power consumption of the defrosting means 47.

[0030] In addition to the above, the defrosting means 47 that heats the cooler 37 is not limited to an electric heater, but may also be, for example, so-called hot gas supplied to the cooler 37 from the compressor 39 of the condensing unit 38. The cooler 37 of the display case 1 and the evaporator 41 of the cooling means 7 of the cooler storage 2 may be arranged in different refrigeration cycles. In this case, the solenoid valve 44 upstream of the cooler 37 can be omitted, and the supply of refrigerant to the cooler 37 can be switched by on / off control of the compressor connected to the cooler 37. The cooling means 7 of the cooler storage 2 is not limited to a unit cooler, but may also be a device that supplies cold air to the cooling chamber 6 from the outside, or a device that cools the walls of the cooling chamber 6. Furthermore, the present invention can be applied not only to walk-in showcases for displaying and selling products to be cooled, but also to cold storage warehouses and frozen warehouses for picking products to be cooled. In this case, the front opening of the display case 1 in which the products to be cooled are displayed faces the workspace of the workers who pick the products to be cooled. [Explanation of Symbols]

[0031] 1 Display case 2 Refrigerator 6 Cooling room 7 Cooling means 10 Case body 12 Exhibition room 15 Bulkhead 16. First ceiling duct 17. Second ceiling duct 18 External duct 21 1st air outlet (air outlet) 22 2nd air outlet (air outlet) 23 External air outlet 30. Blower means 31 First Fan 32 Second Fan 33 Third Fan 37 Cooler 38 Condensing Units 47 Defrosting means

Claims

1. A cooling device comprising a cooling cabinet (2) and a display case (1), The cooling cabinet (2) is equipped with a cooling chamber (6) which is cooled by a cooling means (7), The display case (1) comprises a case body (10) having openings on its front and rear surfaces, a cooler (37) for cooling the air inside the case body (10), a defrosting means (47) for heating the cooler (37), a blower (30) for forming an air curtain along the front opening of the case body (10), and a control unit for controlling the defrosting means (47) and the blower (30). The inside of the case body (10) is divided into a display room (12) for displaying the items to be cooled, a first ceiling duct (16) for housing the cooler (37), and a second ceiling duct (17) separated from the first ceiling duct (16) by a partition wall (15). The rear ends of the first ceiling duct (16) and the second ceiling duct (17) are in communication with the cooling chamber (6). The front ends of the first ceiling duct (16) and the second ceiling duct (17) are provided with downward-facing air outlets (21 and 22) facing the front opening of the case body (10). The air blowing means (30) includes a first fan (31) for taking in air from the cooling chamber (6) into a first ceiling duct (16) and blowing it out from an outlet (21), and a second fan (32) for taking in air from the cooling chamber (6) into a second ceiling duct (17) and blowing it out from an outlet (22). A cooling device characterized in that, in a defrosting mode in which the control unit heats the cooler (37) with a defrosting means (47), it stops the first fan (31) and drives the second fan (32).

2. An external duct (18) is provided on the outer side of the case body (10). An external outlet (23) is provided at the lower end of the external duct (18), opening downward in front of the outlet (22) of the second ceiling duct (17). The ventilation means (30) includes a third fan (33) for taking in air from outside the display case (1) into an external duct (18) and blowing it out from an external outlet (23). The cooling device according to claim 1, wherein the control unit in defrost mode drives a third fan (33) in addition to the second fan (32).

3. The display case (1) has three operating modes: a strong cooling mode in which the refrigerant liquefied by the condensing unit (38) is supplied to the cooler (37); a weak cooling mode in which the supply of the refrigerant is stopped; and a defrosting mode in which the supply of the refrigerant is stopped and the cooler (37) is heated by the defrosting means (47). The cooling device according to claim 1 or 2, wherein the control unit drives the first fan (31) and the second fan (32) in the strong cooling mode and the weak cooling mode.

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