showcase

Abstract

This disclosure provides a showcase that can heat products on a shelf to an appropriate temperature while keeping power consumption low. [Solution] The showcase of this disclosure comprises a plurality of product shelves provided inside a display room, a cooling device for cooling the display room, heaters provided on the product shelves, a control device for performing cooling control to supply power to the cooling device and heating control to supply power to the heaters, wherein the heater provided on at least the uppermost of the plurality of product shelves consists of an electrically independent main heater and an auxiliary heater provided outside the main heater, and the control device performs ON / OFF control so that the current values ​​of the main heater and the auxiliary heater provided on the product shelf to be heated do not exceed the rated current value.

Description

Technical Field

[0001] The present disclosure relates to a showcase.

Background Art

[0002] Patent Document 1 discloses a showcase including a showcase body having an inner product storage section, a cooling device for supplying cold air to the product storage section, one or more product shelves disposed in the product storage section, a product shelf heater attached to the product shelf, and a control device for controlling power supply to the cooling device and the product shelf heater. The control device controls power supply to the product shelf heater so that the power consumption of the product shelf heater is reduced while the cooling device is energized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a showcase that can warm the products on the product shelf to be warmed to an appropriate temperature while suppressing power consumption.

Means for Solving the Problems

[0005] The showcase in this disclosure comprises a plurality of product shelves installed inside a display room, a cooling device for cooling the display room, heaters installed on the product shelves, a control device for performing cooling control to supply power to the cooling device and heating control to supply power to the heaters, wherein the heater installed on at least the uppermost of the plurality of product shelves consists of an electrically independent main heater and an auxiliary heater installed outside the main heater, and the control device performs ON / OFF control so that the current values ​​of the main heater and the auxiliary heater installed on the product shelf to be heated do not exceed the rated current value. [Effects of the Invention]

[0006] According to the showcase of this disclosure, the main heater and auxiliary heater can be controlled so as not to exceed the rated current value of the commercial power supply, thereby reducing power consumption and allowing the products on the shelves to be heated to an appropriate temperature. [Brief explanation of the drawing]

[0007] [Figure 1] Perspective view showing the showcase in Embodiment 1 [Figure 2] Plan view showing the configuration of the first and second shelf units in Embodiment 1. [Figure 3] Plan view showing the configuration of the third to fifth shelves in Embodiment 1. [Figure 4] Block diagram showing the control configuration in Embodiment 1 [Figure 5] Timing chart showing heater power control when the first shelf is heated and shelves 2 through 5 are cooled. [Figure 6] Timing chart showing heater power control when the first and second shelves are heated and the third through fifth shelves are cooled. [Figure 7] Timing chart showing heater power control when the first to fifth shelves of merchandise are to be heated. [Modes for carrying out the invention]

[0008] (Knowledge and other information that formed the basis of this disclosure) At the time the inventors conceived of this disclosure, there was a technology in display cases that used a control device to control the power supply to the shelf heaters so that the power consumption of the shelf heaters would be reduced while the cooling device was powered. In this case, if the showcase is to be used with a single-phase 100V commercial power supply, it is necessary to ensure that the electrical rating of the outlet does not exceed 15A to 125V. For example, in conventional technology, a product shelf heater consists of a first product shelf heater and a second product shelf heater, the first product shelf heater is located on the periphery of the product shelf, and the second product shelf heater is located inside the first product shelf heater. The control device operates the first and second product shelf heaters while the power supply to the cooling device is stopped, and stops operating the second product shelf heater while the power supply to the cooling device is on. However, with conventional technology, if the cooling device remains powered on, the second shelf heater remains stopped, which causes the temperature of the products on the heated shelves directly above the cooling target to drop. Furthermore, the front row of shelves, especially the corners, directly above the shelves to be cooled, is particularly susceptible to the influence of ambient temperature and therefore difficult to heat. The inventors discovered that if the capacity of the shelf heaters is set to match the shelves that are difficult to heat, the overall heater capacity becomes high, and there is a risk that the current value of the showcase may exceed the rated current value of the outlet (15A). The subject matter of this disclosure was developed to solve this problem. Therefore, this disclosure provides a showcase that can heat products on a shelf to be heated to an appropriate temperature while keeping power consumption low.

[0009] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The attached drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0010] (Embodiment 1) Embodiment 1 will be described below with reference to the drawings. [1-1. Structure] [1-1-1. Overall configuration of the showcase] Figure 1 is a perspective view showing a showcase in Embodiment 1. In this embodiment, the case in which an open showcase is applied as the showcase of this disclosure will be explained as an example. Showcase 1 is placed on the floor of a store, such as a supermarket or convenience store, and displays beverages, food, and other products in a refrigerated state. Showcase 1 is a so-called open-type showcase.

[0011] Showcase 1 is equipped with a roughly box-shaped case 10 with an opening at the front for loading and unloading products. Hereinafter, the opening direction of case 10 in the horizontal direction will be referred to as the front, and the direction perpendicular to the front-to-back direction in the horizontal direction will be referred to as the width direction or left-to-right direction.

[0012] Inside case 10, there is a display room 11 where products are displayed. The case 10 includes a deck pan 12 located below the display compartment 11, a pair of side panels 13 located on both sides of the display compartment 11, a top panel 14 located above the display compartment 11, and a back panel (not shown) located at the rear of the display compartment 11. The display room 11 has a shape in which all sides except the front are covered by a deck pan 12, side panels 13, a top panel 14, and a back panel.

[0013] Below the case 10, a machine room 15 is provided. Inside the machine room 15, a compressor, a condenser, a fan, etc. (not shown) are accommodated. Below the deck pan 12, a cold air duct for circulating cold air is provided. One end of the cold air duct extends upward along the back surface of the display chamber 11 and communicates with an air outlet (not shown) provided in the upper front part of the display chamber 11. On the other hand, the other end of the cold air duct communicates with a suction port 16 provided on the front side of the deck pan 12. An evaporator is provided inside the cold air duct of the machine room 15, and the compressor, the condenser, an expansion mechanism provided below the deck pan, and the evaporator constitute a cooling device 17.

[0014] Also, an exhaust duct is provided inside the machine room 15. The exhaust duct extends upward along the back side of the cold air duct of the display chamber 11 and communicates with the upper part of the case 10. Then, the refrigerant sent from the compressor to the condenser and cooled is sent to the evaporator. The evaporator cools the air flowing through the duct and sends it to the air outlet, and the air after cooling the display chamber 11 is sucked into the duct from the suction port 16. Thereby, the inside of the display chamber 11 can be cooled. On the other hand, the air after heat-exchanging with the condenser in the machine room 15 is exhausted from the upper part of the case through the exhaust duct.

[0015] [1-1-2. Structure of the merchandise shelf] Inside the display chamber 11, a merchandise shelf 20 is provided. In the present embodiment, the merchandise shelf 20 is provided in five stages, and from the merchandise shelf 20 located above, they are the first-stage merchandise shelf 20a, the second-stage merchandise shelf 20b, the third-stage merchandise shelf 20c, the fourth-stage merchandise shelf 20d, and the fifth-stage merchandise shelf 20e. In the following description, when explaining the merchandise shelf in general, it will be described as "the merchandise shelf 20". Each of the first-stage merchandise shelf 20a to the fifth-stage merchandise shelf 20e is configured to be able to function as a merchandise shelf 20 to be heated or cooled.

[0016] Figure 2 is a plan view showing the configuration of the first and second shelves in Embodiment 1. Since the configuration of the first shelf 20a and the second shelf 20b are the same, the following description will focus on the first shelf 20a.

[0017] As shown in Figure 2, the first-tier product shelf 20a is equipped with a flat product shelf body 21. The product shelf body 21 is provided with a main heater 22. The main heater 22 is arranged in multiple rows (five rows in this embodiment) along the outer edge of the product shelf body 21. An auxiliary heater 23 is provided on the outside of the main heater 22 of the product shelf body 21. In this embodiment, the power supply capacity of the main heater 22 is greater than that of the auxiliary heater 23, while the power supply capacity per unit length of the main heater 22 is less than that of the auxiliary heater 23. Specifically, for example, the power supply capacity of the main heater 22 is 245W, and the power supply capacity per unit length is 27.8W / m. Furthermore, the power supply capacity of the auxiliary heater 23 is 76W, and the power supply capacity per unit length is 37.0W / m.

[0018] Figure 3 is a plan view showing the configuration of the third to fifth shelves in Embodiment 1. Since the configuration of the third to fifth shelves 20c to 20e is the same, the following description will focus on the third shelf 20c. As shown in Figure 3, the third-tier product shelf 20c is similarly equipped with a product shelf body 21. The main shelf unit 21 is equipped with a main heater 24. There is no auxiliary heater 23. The main heaters 24 are arranged in multiple rows (five rows in this embodiment) along the outer edge of the product shelf body 21. In this embodiment, for example, the power supply capacity of the main heater 24 is 290W, and the power supply capacity per unit length is 29.3W / m.

[0019] [1-1-3. Control Configuration] Next, the control configuration in Embodiment 1 will be described. Figure 4 is a block diagram showing the control configuration in Embodiment 1. As shown in Figure 4, the showcase 1 is equipped with a control device 30. The control device 30 includes a processor 31 such as a CPU (Central Processing Unit) or MPU (Micro Processor Unit), a memory 32, and an interface circuit (not shown) for connecting other devices and sensors.

[0020] Memory 32 is a storage device that stores programs and data. Memory 32 has a non-volatile storage area and stores a predetermined control program. Memory 32 is composed of, for example, ROM (Read Only Memory) or RAM (Random Access Memory). The processor 31 controls each part of the showcase 1 by reading and operating the control program stored in the memory 32.

[0021] The control device 30 is connected to the main heater 22 and auxiliary heater 23 of the first-stage product shelf 20a, the main heater 22 and auxiliary heater 23 of the second-stage product shelf 20b, the main heater 24 of the third-stage product shelf 20c, the main heater 24 of the fourth-stage product shelf 20d, and the main heater 24 of the fifth-stage product shelf 20e. The control device 30 receives detection values ​​from temperature sensors 35 installed on the first to fifth shelves 20a and 20e respectively, and based on these detection values ​​from the temperature sensors 35, it performs ON / OFF control of each main heater 22, 24 and auxiliary heater 23, and output control of each main heater 22, 24 and auxiliary heater 23.

[0022] In this embodiment, the power required for the operation of the showcase 1 includes the power of the cooling device 17, such as the compressor, and the power of the main heaters 22 and 24 and the auxiliary heater 23. In this embodiment, the power supply for the showcase 1 is 100V, which is commercial power. The control device 30 controls the cooling device 17, the main heaters 22, 24, and the auxiliary heaters 23 so that the current value due to the power of the cooling device 17 and the current value due to the power of the main heaters 22, 24, and the auxiliary heaters 23 do not exceed the rated current value of the commercial power supply, which is 15A.

[0023] [1-2. Effect] Next, the operation of Embodiment 1 will be described. Figure 5 is a timing chart showing the heater power supply control when the first shelf is heated and the second to fifth shelves are cooled. As shown in Figure 5, the main heater 22 and auxiliary heater 23 of the first-tier product shelf 20a, which is to be heated, are simultaneously controlled ON / OFF based on the values ​​detected by the temperature sensor 35. Since the second to fifth shelves 20b to 20e are designated for cooling, the main heaters 22 and 24 and the auxiliary heater 23 are controlled to be constantly OFF.

[0024] Figure 6 is a timing chart showing the heater power control when the first and second shelves are heated and the third through fifth shelves are cooled. As shown in Figure 6, when the main heaters 22 of the first shelf 20a and the second shelf 20b are controlled to be ON simultaneously, the auxiliary heaters 23 are controlled to be OFF. Furthermore, if either the main heater 22 of the first-tier shelf 20a or the second-tier shelf 20b is controlled to OFF, the auxiliary heaters 23 of the first-tier shelf 20a and the second-tier shelf 20b are simultaneously controlled to ON. Since the third shelf 20c through the fifth shelf 20e are designated for cooling, the main heater 24 is controlled to be constantly OFF.

[0025] Figure 7 is a timing chart showing the heater power supply control when the first to fifth shelves of merchandise are to be heated. As shown in Figure 7, when the first to fifth shelves 20a to 20e are to be heated, the control device 30 controls the auxiliary heaters 23 of the first shelf 20a and the second shelf 20b to ON if the main heaters 22, 24 of at least one shelf 20 among the first to fifth shelves 20a to 20e are controlled to OFF. Furthermore, if all the main heaters 22,24 of the first-stage product shelves 20a to the fifth-stage product shelves 20e are controlled to be ON, the control device 30 controls the auxiliary heaters 23 of the first-stage product shelves 20a and the second-stage product shelves 20b to be OFF. By controlling the ON / OFF states of the main heaters 22 and 24 and the auxiliary heater 23 in this way, the overall power consumption of the showcase 1 can be reduced.

[0026] The following example, using Figure 6 as a typical example where the first and second shelves are heated and the third through fifth shelves are cooled, will show specific examples of how to control the ON / OFF state of the main and auxiliary heaters so that their current values ​​do not exceed their rated current values. The commercial power supply is rated at 15A, 125V, but the design incorporates a 10% safety margin, resulting in a maximum current of 13.6A. The current values ​​for the main heaters 22 of the first-tier product shelves 20a and the second-tier product shelves 20b are 2.4A, the current value for the auxiliary heaters 23 is 0.7A, and the other current value is 8.8A. Here, the other current value refers to the current value when the cooling device 17, lighting, control device 30, etc. are in operation, and is the value when the cooling device 17 is operating at the upper limit of the compressor rotation speed and the lighting is on.

[0027] First, in the T0-T1 region, we want to heat the first-stage product shelf 20a and the second-stage product shelf 20b, so we control the main heaters 22 of both the first-stage product shelf 20a and the second-stage product shelf 20b to be ON. In this state, the current value is 2.4A × 2 + 8.8A = 13.6A. If the auxiliary heater is turned ON, the current will be 15.0A, so auxiliary heater 23 is turned OFF.

[0028] In the T1-T2 region, since the first-stage product shelf 20a has reached the desired temperature, the main heater 22 of the first-stage product shelf 20a is controlled to OFF. In order to heat the outer edges of the first-stage product shelf 20a and the second-stage product shelf 20b, which are difficult to heat, the auxiliary heaters 23 of the first-stage product shelf 20a and the second-stage product shelf 20b are controlled to ON. The current value in this state is 2.4A + 0.7A × 2 + 8.8A = 12.6A.

[0029] In the T2-T3 region, it is controlled in the same way as in T0-T1. In the T3-T4 region, since the second shelf 20b has reached the desired temperature, the main heater 22 of the second shelf 20b is controlled to OFF. In order to heat the outer edges of the first shelf 20a and the second shelf 20b, which are difficult to heat, the auxiliary heaters 23 of the first shelf 20a and the second shelf 20b are controlled to ON. The current value in this state is 2.4A + 0.7A × 2 + 8.8A = 12.6A.

[0030] In the T4-T5 region, since the first-stage product shelves 20a and the second-stage product shelves 20b have reached the desired temperature, the main heaters 22 of the first-stage product shelves 20a and the second-stage product shelves 20b are controlled to OFF. In order to heat the outer edges of the first-stage product shelves 20a and the second-stage product shelves 20b, which are difficult to heat, the auxiliary heaters 23 of the first-stage product shelves 20a and the second-stage product shelves 20b are controlled to ON. The current value in this state is 0.7A × 2 + 8.8A = 10.2A. In the T5 region and beyond, control is performed in the same way as in T0-T1.

[0031] [1-3. Effects, etc.] As described above, the showcase 1 in this embodiment comprises a plurality of product shelves 20 installed inside the display room 11, a cooling device 17 for cooling the display room 11, heaters 22, 23, and 24 installed on the product shelves 20, and a control device 30 that performs cooling control to supply power to the cooling device 17 and heating control to supply power to the heaters 22, 23, and 24. Of the plurality of product shelves 20, the heaters 22 and 23 installed on at least the first-tier product shelf 20a (product shelf) located on the uppermost tier consist of an electrically independent main heater 22 and an auxiliary heater 23 installed outside the main heater 22. The control device 30 performs ON / OFF control so that the current values ​​of the main heater 22 and auxiliary heater 23 installed on the product shelf 20 to be heated do not exceed the rated current value. This allows the main heater 22 and auxiliary heater 23 to be controlled so as not to exceed the rated current value of the commercial power supply, thereby reducing power consumption and allowing the products on the product shelf 20 to be heated to an appropriate temperature.

[0032] Furthermore, in this embodiment, the showcase 1 has the main heater 22 and auxiliary heater 23 installed on the topmost first-tier product shelf 20a (product shelf) and the second-to-last second-tier product shelf 20b (product shelf) of the product shelves 20. The control device 30 simultaneously turns the main heaters 22, 24 and the auxiliary heater 23 ON / OFF when the first-tier product shelf 20a is to be heated and the other second-tier product shelves 20b to fifth-tier product shelves 20e are to be cooled. As a result, when the first-tier product shelf 20a is designated for heating, the main heater 22 and auxiliary heater 23 can be controlled to keep the current of the main heater 22 and auxiliary heater 23 from exceeding the rated current value of the commercial power supply by simultaneously turning them ON / OFF. Therefore, power consumption can be suppressed, and the products on the first-tier product shelf 20a can be heated to an appropriate temperature.

[0033] Furthermore, in this embodiment, the showcase 1 has a main heater 22 and an auxiliary heater 23 installed on the topmost first-tier product shelf 20a (product shelf) and the second-to-last second-tier product shelf 20b (product shelf) of the product shelves 20. The control device 30 controls the first-tier product shelf 20a and the second-tier product shelf 20b to be heated, and the other third-tier product shelves 20c to the fifth-tier product shelves 20e to be cooled. When the main heaters 22 of the first-tier product shelf 20a and the second-tier product shelf 20b are controlled to ON, the auxiliary heater 23 is controlled to OFF. When either of the main heaters 22 of the first-tier product shelf 20a and the second-tier product shelf 20b is controlled to OFF, the auxiliary heater 23 is controlled to ON. As a result, when the first-tier product shelves 20a and the second-tier product shelves 20b are designated for heating, if the main heaters 22 of the first-tier product shelves 20a and the second-tier product shelves 20b are controlled to be ON, the auxiliary heaters 23 are controlled to be OFF. Conversely, if either of the main heaters 22 of the first-tier product shelves 20a and the second-tier product shelves 20b is controlled to be OFF, the auxiliary heaters 23 are controlled to be ON. This allows the main heaters 22 and auxiliary heaters 23 to be controlled so as not to exceed the rated current value of the commercial power supply. Therefore, power consumption can be suppressed, and the products on the product shelves 20a and 20b can be heated to an appropriate temperature.

[0034] Furthermore, in this embodiment, the showcase 1, when all product shelves 20 are to be heated, controls the control device 30 to turn on all auxiliary heaters 23 if the main heaters 22, 24 of at least one product shelf 20 are controlled to OFF, and controls the auxiliary heaters 23 to turn OFF if the main heaters 22, 24 of all product shelves 20 are controlled to ON. As a result, when all product shelves 20 are to be heated, if the main heaters 22,24 of at least one product shelf 20 are controlled to OFF, all auxiliary heaters 23 are controlled to ON, and if the main heaters 22,24 of all product shelves 20 are controlled to ON, the auxiliary heaters 23 are controlled to OFF, thereby controlling the main heaters 22,24 and auxiliary heaters 23 so as not to exceed the rated current value of the commercial power supply. Therefore, power consumption can be suppressed and the products on the product shelves 20 to be heated can be heated to an appropriate temperature.

[0035] (Other embodiments) As described above, Embodiment 1 has been explained as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to create new embodiments by combining the components described in Embodiment 1 above. Therefore, other embodiments are illustrated below.

[0036] In the above embodiment, an example was described in which the product shelf 20 has five shelves, but the disclosure is not limited thereto. For example, a product shelf 20 with four shelves may be provided, and a main heater 22 and an auxiliary heater 23 may be provided on the top shelf and the second shelf 20.

[0037] Furthermore, although the above embodiment described the showcase 1 as an open-type showcase 1, this is merely an example. The showcase 1 may also be a closed-type showcase 1 having a transparent door that closes the display compartment 11 from the front. Alternatively, the showcase 1 may be a showcase with a door that prevents the interior from being seen.

[0038] [Configurations supported by the above embodiment] The above embodiment supports the following configuration.

[0039] (Note) Based on the above description of embodiments, the following technologies are disclosed. (Technical 1) A showcase comprising: a plurality of product shelves installed inside a display room; a cooling device for cooling the display room; heaters installed on the product shelves; a control device for performing cooling control to supply power to the cooling device and heating control to supply power to the heaters, wherein the heater installed on at least the uppermost of the plurality of product shelves consists of an electrically independent main heater and an auxiliary heater installed outside the main heater, and the control device performs ON / OFF control so that the current values ​​of the main heater and the auxiliary heater installed on the product shelf to be heated do not exceed the rated current value. This configuration allows the main heater and auxiliary heater to be controlled so as not to exceed the rated current value of the commercial power supply, thereby reducing power consumption and ensuring that the products on the shelves are heated to an appropriate temperature.

[0040] (Technology 2) The showcase according to Technology 1, wherein the main heater and the auxiliary heater are provided on the uppermost and second-to-last shelves of the product shelves, and the control device simultaneously turns the main heater and the auxiliary heater ON / OFF when the uppermost shelf is to be heated and the other product shelves are to be cooled. With this configuration, when the top shelf of merchandise is to be heated, the main heater and auxiliary heater can be controlled to stay within the limits of the commercial power supply's rated current by simultaneously turning them ON / OFF. This reduces power consumption while ensuring that the merchandise on the shelves is heated to the appropriate temperature.

[0041] (Technical 3) The showcase according to Technical 1, wherein the main heater and the auxiliary heater are provided on the uppermost and second-to-last shelves of the product shelves, and the control device controls the auxiliary heater to be turned OFF when the uppermost and second-to-last shelves are to be heated and the other shelves are to be cooled, and when the main heaters of the uppermost and second-to-last shelves are controlled to be turned ON, the auxiliary heater is controlled to be turned ON when either of the main heaters of the uppermost or second-to-last shelves is controlled to be turned OFF. With this configuration, when the top or second shelf of merchandise is designated for heating, if the main heater of the top or second shelf is controlled to ON, the auxiliary heater is controlled to OFF. Conversely, if either of the main heaters of the top or second shelf is controlled to OFF, the auxiliary heater is controlled to ON. This allows the main and auxiliary heaters to be controlled so as not to exceed the rated current value of the commercial power supply. As a result, power consumption can be reduced, and the merchandise on the shelves to be heated can be heated to an appropriate temperature.

[0042] (Technical 4) The showcase according to Technical 1, wherein the control device controls all auxiliary heaters to ON when all of the product shelves are to be heated, and when the main heater of at least one of the product shelves is controlled to OFF, and when the main heater of all of the product shelves is controlled to ON, the auxiliary heaters are controlled to OFF. With this configuration, if all product shelves are to be heated, and the main heater of at least one product shelf is controlled to be OFF, all auxiliary heaters are controlled to be ON. If the main heaters of all product shelves are controlled to be ON, the auxiliary heaters are controlled to be OFF. This allows the main heaters and auxiliary heaters to be controlled so as not to exceed the rated current value of the commercial power supply. As a result, power consumption can be suppressed, and the products on the product shelves to be heated can be heated to an appropriate temperature. [Industrial applicability]

[0043] This disclosure is suitably applicable as a showcase that can heat products on a shelf to be heated to an appropriate temperature while keeping power consumption low. [Explanation of Symbols]

[0044] 1. Showcase 10 cases 11 Exhibition room 12 deck pans 13 Side panel 14 Top plate 15 Machine room 16 Inlet 17 Cooling device 20 product shelves 20a 1st stage product shelf 20b 2nd stage product shelf 20c 3rd tier product shelf 20d 4th stage product shelf 20e 5th tier product shelf 21 Main shelf unit 22 Main heater 23 Auxiliary heater 24 Main heater 30 Control device 31 processors 32 memory 35 Temperature Sensor

Claims

1. Multiple product shelves installed inside the display room, A cooling device for cooling the aforementioned display room, A heater installed in the aforementioned product shelf, The system includes a control device that performs cooling control, which supplies power to the cooling device, and heating control, which supplies power to the heater. The heater provided on at least the uppermost of the multiple product shelves consists of an electrically independent main heater and an auxiliary heater provided outside the main heater. The control device performs ON / OFF control so that the current values ​​of the main heater and the auxiliary heater installed on the product shelf to be heated do not exceed the rated current value. A display case.

2. The main heater and the auxiliary heater are provided on the top shelf and the second shelf from the top of the product shelves. The control device simultaneously turns the main heater and the auxiliary heater ON / OFF when the uppermost product shelf is to be heated and the other product shelves are to be cooled. The showcase according to claim 1.

3. The main heater and the auxiliary heater are provided on the top shelf and the second shelf from the top of the product shelves. When the top and second-tier product shelves are to be heated and the other product shelves are to be cooled, the control device controls the auxiliary heater to OFF when the main heaters of the top and second-tier product shelves are controlled to ON, and controls the auxiliary heater to ON when either of the main heaters of the top or second-tier product shelves is controlled to OFF. The showcase according to claim 1.

4. The control device, when all of the product shelves are to be heated, controls all of the auxiliary heaters to ON if the main heater of at least one of the product shelves is controlled to OFF, and controls the auxiliary heaters to OFF if the main heaters of all of the product shelves are controlled to ON. The showcase according to claim 1.

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