JP2009174732A - Showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a showcase capable of reducing current capacity as a whole by controlling power distribution to an evaporation pan heater according to the ratio of a cooling use area and a heating use area in a display chamber. <P>SOLUTION: This showcase 1 comprising a shelf heater 22 for heating a shelf in the display chamber 11, and an evaporator 15 for cooling the inside of the display chamber, and capable of constituting the heating use area and the cooling use area in the display chamber in a state that their ratio can be changed, further comprises the evaporation pan 32 receiving drainage from the evaporator 15 and the like, the evaporation pan heater 51, a temperature sensor 52 detecting a temperature of the evaporation pan or the like, and a control device C controlling power distribution of the evaporation pan heater on the basis of the output of the temperature sensor. The evaporation pan heating control in defrosting, and the low-water cut-off control evaporation pan heating control detecting the presence or absence of drainage and controlling the power distribution to the evaporation pan heater 51 can be executed, and whether the evaporation pan heating control in defrosting and the low-water cut-off control evaporation pan heating control are executed or not, is decided according to the ratio of the heating use area and the cooling use area. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes a shelf heater that heats a shelf in the display room, and an evaporator that cools the display room, and includes a heating use area that is heated by the shelf heater in the display room, and a cooling use area that is cooled by the evaporator. This is a showcase that can change the ratio, and particularly relates to control of a heater provided in an evaporating dish that receives drain water from an evaporator.

  Conventionally, an evaporator is installed in a low temperature storage such as a low temperature showcase, and cool air exchanged with the evaporator is forcibly circulated in the cabinet for cooling. Since this evaporator is frosted by operation, the evaporator defrosting operation is executed periodically or at an arbitrary time. This defrosting operation includes a so-called OFF cycle defrosting operation in which only the blower is operated in a state where the supply of refrigerant to the evaporator is stopped, a heater defrosting operation in which the evaporator is heated by an evaporating dish heater, or evaporation. There is hot gas defrosting operation that allows hot gas (high-temperature refrigerant) to flow into the evaporator, but in any case, drain water (defrosted water that has melted frost) will drip from the evaporator and this must be treated. There is.

  When processing this drain water, an evaporating dish is usually installed and the drain water is received in the evaporating dish. And while the evaporating dish was forcibly heated by the evaporating dish heater, the outside air was ventilated by the blower to evaporate the drain water received in the evaporating dish.

  In this case, the electric heater stops energization of the electric heater when the predetermined upper limit temperature is reached based on the detection output of the evaporating dish temperature sensor provided in the evaporating dish, and the evaporating dish temperature reaches the predetermined lower limit temperature. When reaching, ON-OFF control for starting energization of the electric heater has been performed. However, since the ON-OFF control is continuously performed while the low temperature storage is being operated, the temperature of the evaporating dish is actually in a certain high temperature range (for example, regardless of the presence or absence of drain water in the evaporating dish). + 60 ° C.).

  Therefore, even when there is no drain water in the evaporating dish, the evaporating dish is heated, which increases the power consumption, and there is an unnecessarily large machine room in which the evaporating dish is provided. Being heated also contributes to an increase in the thermal load on the compressor and condenser disposed in the machine room.

  Therefore, conventionally, the drain water in the evaporating dish is evaporated by energizing the electric heater according to the defrosting time in which the drain water is predicted to be stored in the evaporating dish. (See Patent Document 1).

On the other hand, the conventional showcase includes a shelf heater for heating a shelf installed in the display room, and an evaporator for cooling the display room, and a heating use area heated by the shelf heater; The cooling use area cooled by the evaporator is configured in the display room, the flow of cold air cooled by the evaporator is controlled by a damper, etc., and each shelf heater is energized and controlled. In some cases, the ratio between the area and the cooling use area (actually, the number of shelves used for heating and the number of shelves used for cooling) can be changed.
JP 2002-295958 A

  As described above, in the showcase that configures the heating use area and the cooling use area that allow the ratio to be changed in the display room, the amount of frost formed on the evaporator and the drain water that is received by the evaporating dish depends on the use ratio. The amount is different. That is, when the ratio of the cooling use area is large, the amount of frost formation is large and the amount of drain water in the evaporating dish increases, and when the ratio of the heating use area is large, the amount of frost formation is small and The amount of drain water decreases.

  As in the case of a large amount of drain water, as in the case of a large amount, it is more than necessary to control the evaporating dish heater to maintain the evaporating dish at a constant high temperature and to energize the evaporating dish heater according to the defrosting time. The evaporating dish heater will be heated, and the running cost will rise.

  In addition, when the ratio of the heating use area is large, the current capacity to the shelf heater increases, and when the evaporating dish heater is energized at the same time, the peak current capacity of the entire showcase increases and the capacity of the rated power supply It was necessary to raise.

  Therefore, the present invention has been made to solve the conventional technical problem, and controls the energization of the evaporating dish heater according to the ratio of the cooling use area and the heating use area configured in the display chamber, and the showcase. Provided is a showcase capable of realizing a reduction in current capacity as a whole.

  The showcase of the present invention includes a shelf heater for heating a shelf installed in the display room, an evaporator for cooling the display room, a heating use region heated by the shelf heater, and an evaporator. The cooling use area to be cooled can be configured in the display chamber, and the ratio of these areas can be changed, and an evaporating dish for receiving drain water from an evaporator or the like, and the evaporating dish An evaporating dish heater for heating the evaporating dish heater, a temperature sensor for detecting the temperature of the evaporating dish or drain water in the evaporating dish, and a control device for controlling energization of the evaporating dish heater based on the output of the temperature sensor, The controller supplies power to the evaporating dish heater during defrosting of the evaporator to evaporate the drain water in the evaporating dish, and supplies power to the evaporating dish heater every predetermined time. Drain water in the evaporating dish according to the gradient When the presence or absence of drain water is determined, the evaporating dish heater can be energized to carry out the emptying evaporating dish heating control that evaporates the drain water in the evaporating dish. It is characterized by determining whether to perform evaporating dish heating control at the time of defrosting and emptying prevention evaporating dish heating control according to the ratio of a use area and a cooling use area.

  The showcase of the invention of claim 2 is the above-described invention, wherein the control device performs the defrosting evaporating dish heating control and the emptying prevention evaporating dish heating control when the ratio of the cooling use area in the display room is large. The evaporating dish heating control at the time of defrosting or the emptying prevention evaporating dish heating control or both of them is not executed in accordance with the increase in the ratio of the heating use area.

  According to the present invention, the apparatus includes a shelf heater for heating a shelf installed in the display room, an evaporator for cooling the display room, a heating use area heated by the shelf heater, and cooling by the evaporator. In the showcase in which the cooling use area can be configured in the display room and the ratio of these areas can be changed, the evaporating dish for receiving drain water from the evaporator and the like, and heating the evaporating dish An evaporating dish heater, a temperature sensor for detecting the temperature of the evaporating dish or drain water in the evaporating dish, and a control device for controlling energization of the evaporating dish heater based on the output of the temperature sensor, The defrosting evaporating dish heating control that energizes the evaporating dish heater to evaporate the drain water in the evaporating dish during defrosting of the evaporator, and energizes the evaporating dish heater every predetermined time, and the temperature gradient at that time Depending on the drain water in the evaporating dish When the presence or absence of drain water is determined, the evaporating dish heater can be energized to carry out the emptying evaporating dish heating control that evaporates the drain water in the evaporating dish. It is determined whether to perform the defrosting evaporating dish heating control and the emptying prevention evaporating dish heating control according to the ratio of the use area and the cooling use area, and the cooling use area in the display chamber as in the invention of claim 2 When the ratio of the defrosting is large, the evaporating dish heating control at the time of defrosting and the emptying prevention evaporating dish heating control are executed. Since the evaporative dish heating control, or both of them are not executed, the heating control of the evaporator heater according to the amount of frost formation on the evaporator determined by the ratio of the cooling use area and the heating use area in the display room, and Evaporation prevention It is possible to perform the heating control.

  Therefore, when the ratio of the heating use area in the display room is large, the amount of frost on the evaporating dish is reduced, and the current carrying capacity of the evaporator heater can be reduced accordingly, and the current capacity of the entire showcase Can be reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a showcase 1 according to an embodiment to which the present invention is applied, and FIG. 2 is a vertical side view of the showcase 1 of FIG. The showcase 1 of an Example is what is called an open showcase installed in stores, such as a convenience store and a supermarket. In the display room 11 for displaying products formed in the showcase 1, a cooling use area, a heating use area, or both a cooling use area and a heating use area can be configured. / It is supposed that it can be used warm.

  The main body 2 is constituted by a heat insulating wall 3 having a substantially U-shaped cross section that opens to the front surface of the showcase 1 and side plates 4 and 4 attached to both sides thereof. A back panel 6 and a top panel 7 are disposed on the back and top surfaces of the inside of the heat insulating wall 3 with a space therebetween, and the back panel 6 and the top panel 7 and the heat insulating wall 3 are spaced from the back. A rear duct 9 extending upward is formed.

  In addition, a deck pan 10 extending forward is provided at the lower end of the back panel 6, and a display chamber 11 is formed inside the back panel 6, the top panel 7, and the deck pan 10. A lower duct 14 communicating with the rear duct 9 and constituting a part thereof is formed below the deck pan 10.

  The upper end of the rear duct 9 communicates with the upper cool air discharge port 16 positioned at the upper edge of the front opening of the display chamber 11, and the front end of the lower duct 14 is positioned at the lower edge of the front opening of the display chamber 11 and includes a plurality of slits. It communicates with the cold air inlet 17. In addition, a cool air circulation blower 19 is disposed in the lower duct 14 below the deck pan 10, and an evaporator 15 constituting a refrigeration cycle of the cooling device R is vertically installed in the rear duct 9 behind the display chamber 11. ing.

  A machine room 25 is formed below the heat insulating wall 3, and in this machine room 25, a compressor 26 that constitutes a refrigerant circuit of the cooling device R together with the evaporator 15, a condenser 27, and a condenser A blower 28 is installed, and an electrical box (not shown) that houses a power source and a control board is also provided. A back plate 29 made of a steel plate is attached to the back of the heat insulating wall 3 with a predetermined distance from the back surface of the heat insulating wall 3, and an exhaust duct is provided between the back plate 29 and the heat insulating wall 3. 30 is configured.

  The lower end of the exhaust duct 30 opens and communicates with the rear portion of the machine room 25, and the upper end is open above the showcase 1. A panel 31 closes the front surface of the machine room 25 so that it can be opened and closed. Reference numeral 32 denotes an evaporating dish provided in the lower part of the machine room 25, and drain water (dewed water, defrosted water, etc.) from the evaporator 15 flows in through a drain hose (not shown) and is stored.

  The evaporating dish 32 is made of a heat conductive material, and an evaporating dish heater (electric heater) 51 for heating the evaporating dish 32 is disposed on the bottom surface. In the evaporating dish 32, an evaporating dish temperature sensor 52 for detecting the temperature of the evaporating dish 32 or the drain water in the evaporating dish 32 is disposed. Further, an evaporation plate 53 is provided in the evaporating dish 32 so that drain water permeates and easily diffuses from the surface thereof. In the present embodiment, Universex (trade name) is used as an example of the evaporation plate 53, and this is made of a nonwoven fabric such as polyester fiber as a base material, and a fine phenol is thermally cured on this base material as a fixing agent. Further, it was dried after soaking in an alcohol solvent after imparting hydrophilicity.

  A plurality of shelves 12 are installed in the display chamber 11, and in this embodiment, four shelves are installed vertically. In the present embodiment, the shelf device 12 at the top level is the shelf device 12A, the shelf device 12 at the second level from the top is the shelf device 12B, and the shelf device 12 at the third level from the top (second level from the bottom) is the shelf device. The shelf device 12 at the lowest level of 12C is referred to as a shelf device 12D. Each shelf device 12 has a pair of left and right brackets 20 having hook-like claws protruding rearward at the rear end, a shelf board 21 mounted on the bracket 20 and mounted thereon, and a product placement surface of the shelf board 21. And a heating shelf heater 22 (electric heater, shown in FIG. 3) attached to the back side of the heater. In this embodiment, the shelf heater 22 includes a shelf heater 22A in the shelf device 12A, a shelf heater 22B in the shelf device 12B, a shelf heater 22C in the shelf device 12C, and a shelf heater 22D in the shelf device 12D. And

  Then, each shelf device 12 is engaged with the engagement holes of the shelf columns (not shown) attached to both front surfaces of the rear panel 6 in the display chamber 11 so that the rack devices 12 can be engaged and disengaged. It is installed so that the vertical position (height) can be changed inside.

  Moreover, in FIG. 2, 35 is a shelf duct member. A shelf duct 36 is formed in the shelf duct member 35, and the front end of the shelf duct 36 is communicated with a shelf cold air discharge port 37 that opens obliquely forward and downward at the front end of the shelf duct member 35, and the rear end is The cold air inlet 38 opens. Further, the shelf duct member 35 is provided with a damper member 39 attached to the upper side of the cold air inlet 38 so as to be movable in the front-rear direction. Further, at the rear end of the damper member 39, damper sensors (damper opening / closing detection means) 39A, 39B, 39C for detecting that the damper member 39 has closed the rear duct 9 are provided. It is connected to a control device C described later.

  On the other hand, in the present embodiment, the back panel 6 is composed of a plurality of back panel members, and a communication portion 40 is formed movably by these back panel members. Therefore, the cold air inlet 38 at the rear end of the shelf duct member 35 is made to correspond to the communication portion 40, and the inner shelf duct 36 is made to communicate with the rear duct 9.

  In such a configuration, by projecting the damper member 39 toward the rear duct 9, the rear duct 9 can be closed on the upper side of the communication portion 40, and the cold air inlet 38 formed at the rear end of the shelf duct 36. Is communicated with the inside of the rear duct 9, so that the cold air in the rear duct 9 is introduced into the shelf duct 36 via the cold air introduction port 38, and the cold air discharge port under the shelf that opens downward at the front opening of the display chamber 11. It is possible to discharge from 37.

  The showcase 1 according to the present embodiment includes a shelf device 12A at the uppermost level, a shelf device 12B at the second level from the top, and a shelf device 12C at the second level from the bottom. Thus, the damper member 39 is operated, and the rear duct 9 can be closed at the height of the operated shelf device 12.

  Next, the control device C of the showcase 1 will be described with reference to FIG. The control device C is a controller composed of a general-purpose microcomputer and incorporates a timer 42 as a time limit means. The timer 42 may have a date mechanism or may count an accumulated time.

  On the input side of the control device C, a discharge cold air temperature sensor 43 that detects the temperature of the discharge cold air to the display chamber 11, a defrost end temperature sensor 44 that detects the temperature of the evaporator 15, and the evaporating dish temperature sensor 52. The damper sensors 39A to 39C, a shelf sensor 45 that detects the temperature of each shelf device 12, and a control panel 46 that performs various settings of the showcase 1 are connected. Here, the shelf sensor 45 is provided in each shelf device 12 and detects a shelf temperature that is a temperature of each shelf device 12.

  On the output side of the control device C, the compressor motor 26M of the compressor 26, the shelf heaters 22 (22A to 22D) provided in each shelf device 12, the evaporating dish heater 51 provided in the evaporating dish 32, and the cold air circulation The blower motor 19M of the blower 19 and the blower motor 28M of the condenser blower 28 are connected. Here, the shelf heater 22 is connected via a heater control unit 49, and the energization amount can be changed by duty control or the like for each of the shelf heaters 22A to 22D.

  The control operation of the showcase 1 will be described with the above configuration. First, the control device C determines the usage status in the display room 11 based on the input setting by the control panel 46 and the outputs of the damper sensors 39A, 39B, 39C.

  Specifically, when the whole is used as a cooling use area, the user moves the damper member 39 provided in each shelf device 12A, 12B, 12C to the foremost position and positions it in front of the rear duct 9, The control panel 46 inputs that the entire display chamber 11 is to be used as a cooling use area. As a result, the control device C determines that the entire display chamber 11 is the cooling use region, de-energizes all the shelf heaters 22A to 22D, and based on the output of the discharge cold air temperature sensor 43, the upper limit temperature (for example, When the temperature is higher than the set temperature + 2 ° C., the compressor 26 is started, and when the temperature is lower than the lower limit temperature (for example, the set temperature −2 ° C.), a cooling operation for stopping the compressor 26 is executed. In this embodiment, the cool air circulation blower 19 and the condenser blower 28 are continuously operated.

  When the compressor 26 is started, high-temperature refrigerant is discharged from the compressor 26. The high-temperature refrigerant discharged from the compressor 26 flows into the condenser 27, where it is cooled by the outside air sucked by the operation of the condenser blower 28. The refrigerant that dissipates heat and condenses in the condenser 27 is decompressed by the decompression device, and then flows into the evaporator 15 and evaporates. At this time, it removes latent heat from the surroundings and exhibits a cooling effect.

  The cool air cooled by exchanging heat with the evaporator 15 rises in the rear duct 9 when the cool air circulation blower 19 is operated, and is discharged from the upper cool air discharge port 16. The discharged cool air cools the display chamber 11 while forming a cool air curtain in the front opening of the display chamber 11. Then, the circulation that is sucked into the lower duct 14 from the cold air suction port 17 and sucked into the blower 19 again is repeated. As a result, the entire area in the display chamber 11 is used as a cooling use area cooled to the refrigeration temperature, and the products on all the shelf devices 12 are cooled to a predetermined cooling temperature.

  Next, when the upper side of the shelf device 12A is the heating use region and the lower side of the shelf device 12A is the cooling use region, the user operates only the damper member 39 of the shelf device 12A, The rear duct 9 is closed at such a height, and the inside of the display chamber 11 above the shelf device 12A is used as a heating use region by the control panel 46, and the inside of the display chamber 11 below the shelf device 12A is used as a cooling use region. Enter the effect.

  As a result, the control device C determines that the inside of the display chamber 11 below the uppermost shelf device 12A is the cooling use region, and cools the compressor 26 based on the output of the discharge cold air temperature sensor 43 as described above. Run the operation. A part of the cool air rising in the rear duct 9 enters the shelf duct 36 of the second shelf device 12C from the bottom through the communication portion 40 formed in the rear panel 6, and is displayed from the shelf lower cool air discharge port 37 to the display chamber. 11 is discharged toward the lower part in the interior. Further, the remaining part of the cold air enters the shelf duct 36 of the second shelf device 12B from the top through the communication portion 40 formed in the back panel 6, and the lower portion in the display chamber 11 from the shelf under-cool air discharge port 37. It is discharged toward. Further, the remaining cold air further rises in the rear duct 9, enters the shelf duct 36 of the uppermost shelf device 12 </ b> A from the communication portion 40, and is discharged from the shelf under-cool air discharge port 37 toward the lower part in the display chamber 11. The As a result, the inside of the display chamber 11 below the uppermost shelf device 12A can be cooled by supplying cold air.

  Further, the control device C uses the damper sensor 39A provided at the rear end of the damper member 39 to detect the closing of the damper member 39, so that the shelf heater 22A of the uppermost shelf device 12A is provided in the shelf device 12A. The energization control is performed based on the temperature detected by the sensor 45 so as to reach a predetermined heating temperature. Thus, the inside of the display chamber 11 above the uppermost shelf device 12A can be heated and used by stopping the cold air supply and energizing the shelf heater 22A.

  In addition, when the upper side of the second shelf device 12B from the top is the heating use region and the lower side of the shelf device 12B is the cooling use region, the user operates the damper member 39 of the shelf device 12B. The rear duct 9 is closed at such a height, the inside of the display chamber 11 on the upper side from the shelf device 12B is set as a heating use region by the control panel 46, and the inside of the display chamber 11 below the shelf device 12B is set as a cooling use region. Enter that you want to.

  Thereby, the control device C determines that the inside of the display chamber 11 below the shelf device 12B in the second stage from the top is the cooling use region, and based on the output of the discharge cold air temperature sensor 43 as described above, the compressor 26 cooling operation is performed. A part of the cool air rising in the rear duct 9 enters the shelf duct 36 of the second shelf device 12C from the bottom through the communication portion 40 formed in the rear panel 6, and is displayed from the shelf lower cool air discharge port 37 to the display chamber. 11 is discharged toward the lower part in the interior. Further, the remaining cold air enters the shelf duct 36 of the second shelf device 12B from the top through the communicating portion 40 formed in the back panel 6, and from the shelf cold air discharge port 37 toward the lower part in the display chamber 11. Discharged. Thereby, the inside of the display chamber 11 below the shelf device 12B at the second stage from the top can be cooled and used by supplying cold air.

  Even in such a case, the control device C detects the closure of the damper member 39 by the damper sensor 39B provided at the rear end of the damper member 39, and the shelf device above the second shelf device 12B from the top. 12, that is, the shelf heaters 22A and 22B of the shelf device 12A in the uppermost stage and the shelf device 12B in the second stage from the top are set to a predetermined heating temperature based on the detection temperature of the shelf sensor 45 provided in the shelf device 12. Energize control. Thereby, the inside of the display chamber 11 above the shelf device 12B in the second stage from the top can be heated and used by stopping the supply of cold air and energizing the shelf heaters 22A and 22B. In such a case, it is desirable that the damper member 39 of the shelf device 12A is closed in order to effectively perform convection of the air in the display chamber 11 above the shelf device 12B in the second stage from the top.

  Similarly, in the case where the upper side from the shelf device 12C at the second stage from the bottom is the heating use region and the lower side from the shelf device 12C is the cooling use region, the user operates the damper member 39 of the shelf device 12C. Then, the rear duct 9 is closed at such a height, the control panel 46 uses the inside of the display chamber 11 above the shelf device 12C as a heating use region, and the inside of the display chamber 11 below the shelf device 12C is used as a cooling use region. Enter that.

  Thereby, the control device C determines that the inside of the display chamber 11 below the shelf device 12C in the second stage from the bottom is the cooling use region, and based on the output of the discharge cold air temperature sensor 43 as described above, the compressor 26 cooling operation is performed. The cool air rising in the rear duct 9 enters the shelf duct 36 of the second shelf device 12C from the bottom through the communication portion 40 formed in the rear panel 6, and the lower portion in the display chamber 11 from the shelf lower cool air discharge port 37. It is discharged toward. Thereby, the inside of the display chamber 11 below the shelf device 12C in the second stage from the bottom can be cooled and used by supplying cold air.

  Even in such a case, the control device C uses the damper sensor 39C provided at the rear end of the damper member 39 to detect the closure of the damper member 39, and the shelf device above the second shelf device 12C from the bottom. 12, that is, the shelf sensor 45 provided on the shelf device 12 is provided with the shelf heaters 22A, 22B, and 22C of the shelf device 12A of the uppermost stage, the shelf device 12B of the second stage from the top, and the shelf device 12C of the second stage from the bottom. The energization is controlled so as to reach a predetermined heating temperature based on the detected temperature. Thereby, the inside of the display chamber 11 above the shelf device 12C, which is the second stage from the bottom, can be heated and used by stopping the cold air supply and energizing the shelf heaters 22A, 22B, and 22C. In such a case, the damper members 39 of the shelf devices 12A and 12B must be closed in order to effectively perform convection of the air in the display chamber 11 above the shelf device 12C in the second stage from the bottom. Is desirable.

  Further, when the entire display chamber 11 is used as the heating use area, the user inputs on the control panel 46 that the entire display room 11 is set as the heating use area. As a result, the control device C stops the cooling device R and the cool air circulation blower 19, energizes the shelf heaters 22 (22 </ b> A to 22 </ b> D) of the shelf devices 12 in all stages, and can use the entire display chamber 11 for heating. To do.

  As described above, when the entire display chamber 11 is used as a cooling use area and when a part of the display chamber 11 is used as a cooling use area, the cooling operation of the cooling device R is executed, whereby the evaporator In 15 frost grows. In order to avoid the frost blockage of the evaporator 15 due to frost formation, the control device C performs a defrosting operation in accordance with conditions as described in detail later.

  In the present embodiment, the control device C starts the defrosting operation of the evaporator 15 at a predetermined time (for example, midnight) set in advance based on the output of the timer 42. During this defrosting operation, the control device C forcibly stops the compressor 26 regardless of the output of the discharge cold air temperature sensor 43, so that the refrigerant supply to the evaporator 15 is stopped. Then, the evaporator 15 is continuously ventilated by a cool air circulation blower 19 and is subjected to so-called OFF cycle defrosting.

  When such a defrosting operation is started, the frost on the evaporator 15 starts to melt gradually, and the drain water that has been melted begins to flow into the evaporating dish 32 through the drain hose. Then, when the frost formation of the evaporator 15 is completely melted and the temperature of the evaporator 15 rises to a predetermined defrosting end temperature, the control device C ends the defrosting operation based on the output of the defrosting end temperature sensor 44. Then, the cooling operation is started again.

  At this time, when the environment such as the set temperature of the cooling use area in the display chamber 11 is set to the same condition, the amount of frost formed on the evaporator 15 changes according to the capacity of the cooling use area. That is, when the entire display room 11 is used as a cooling use area, the cooling use area is circulated as compared with the case where only the inside of the display room 11 below the shelf device 12C at the second stage from the bottom is used as the cooling use area. Since the amount of air to be increased increases, the amount of frost formation in the evaporator 15 increases accordingly.

Therefore, the control apparatus C performs defrosting evaporating dish heating control and emptying prevention evaporating dish heating control according to the ratio of the cooling use area. FIG. 4 is a flowchart for determining the presence or absence of each evaporating dish heating control according to the number of shelf devices 12 used as the heating usage area.
(When the entire display room is used for cooling)
First, in step S1, the control device C determines whether or not the number of shelves used as the internal heating use area of the shelf device 12 currently set on the control panel 46 is zero. When the number of the shelf devices 12 used in the heating use area is 0, that is, when the entire display chamber 11 is the cooling use area, the process proceeds to step S2 and the empty evaporating dish heating control during the cooling operation is performed. Execute. Next, the control device C proceeds to step S3, and executes the defrosting evaporating dish heating control accompanying the defrosting operation.

(Evaporation dish heating control during defrosting)
In the defrosting evaporating dish heating control, the control device C evaporates the evaporating dish 32 when the temperature detected by the evaporating dish temperature sensor 52 decreases to a predetermined lower limit value, that is, the heater ON point. Is energized, and the heater 51 is deenergized when it rises to a predetermined upper limit value, that is, the heater OFF point. Note that the evaporating dish 32 is heated to, for example, about + 60 ° C. by the evaporating dish heating control.

  FIG. 5 shows a timing chart of the evaporating dish heater 51 accompanying the defrosting operation. In such an embodiment, since the heater 51 is not always on-off controlled, the temperature of the evaporating dish 32 is normally substantially the same as the temperature in the machine room 25. Therefore, it is at least lower than the heater ON point. In this state, when the defrosting operation is started, the control device C starts energizing the heater 51 accordingly.

  As a result, the temperature of the evaporating dish 32 or the drain water in the evaporating dish 32 detected by the evaporating dish temperature sensor 52 rises and eventually reaches the heater OFF point. Based on the temperature detection, the control device C deenergizes the heater 51. Thereby, the evaporating dish 32 is gradually cooled by the drain water flowing into the evaporating dish 32 and the outside air temperature, and reaches the heater ON point. Based on the temperature detection, the control device C energizes the heater 51.

  When performing the defrosting operation, the controller C repeatedly executes the evaporating dish heating control regardless of the gradient per time of the temperature change detected by the evaporating dish temperature sensor 52. In this case, when a relay is used for energization control to the heater 51, to prevent a short cycle, a predetermined protection time has elapsed since the heater 51 was de-energized even when the heater OFF point was reached. Until this is done, the heater 51 is not energized. Similarly, even when the heater ON point is reached, the heater 51 is not de-energized until a predetermined protection time elapses after the heater 51 is energized.

  After the defrosting operation is completed, the control device C calculates the gradient of the temperature change of the evaporating dish 32 when the heater 51 is energized, and determines the presence or absence of drain water in the evaporating dish 32. That is, as long as the energization amount of the heater 51 that heats the evaporating dish 32 is the same, if there is drain water in the evaporating dish 32, the heating target is present in addition to the evaporating dish 32, so The temperature rise gradient is slow. On the other hand, when there is no drain water in the evaporating dish 32, only the evaporating dish 32 is heated, so the temperature rise gradient per unit time becomes steeper than when there is drain water.

  Therefore, the control device C calculates the gradient of temperature rise from the temperature difference ΔT detected by the evaporating dish temperature sensor 52 per Δt time (unit time) as shown in FIG. When the calculated gradient of the temperature rise is smaller than the predetermined value and is slow, the control device C determines that there is a lot of drain water in the evaporating dish 32 and continuously executes the evaporating dish heating control. .

  On the other hand, when the calculated gradient of the temperature rise is greater than or equal to the predetermined value and is steep, the control device C determines that there is no drain water in the evaporating dish 32 and that the evaporating dish is heated. The control is terminated (interrupted) and the heater 51 is deenergized.

  Thereby, the presence or absence of drain water in the evaporating dish 32 is determined based on the gradient of the temperature change of the evaporating dish 32 per time, and it is determined that there is no drain water after the defrosting operation of the evaporator 15 and that it is empty. The evaporating dish heating control is finished.

  Therefore, in spite of the drain water remaining in the evaporating dish 32, the evaporating dish heating control is ended, and the evaporating dish 32 is no longer in the evaporating dish 32. It becomes possible to continue the heating control and avoid the inconvenience that wasteful power is consumed, and to perform appropriate evaporating dish heating control.

  In a model in which the power supply capacity of the apparatus is insufficient due to simultaneous energization of the compressor 26 and the heater 51, the compressor 26 is used when the evaporating dish heating control is executed after the defrosting operation of the evaporator 15. Is activated, the evaporating dish heating control is interrupted regardless of the temperature gradient, and the evaporating dish heating control is executed again when the ON-OFF controlled compressor 26 is stopped. good.

  In the present embodiment, the defrosting operation of the evaporator 15 is started at a predetermined time (for example, midnight) based on the timer 42 built in the control device C. For example, the accumulated time from the start of the previous defrosting operation or the end of the defrosting operation is counted by the timer 42, and the accumulated time becomes a predetermined time, for example, 12 hours or 24 hours. The defrosting operation may be started on the condition.

(Empty pan heating control)
In addition, as described above, when the number of the shelf devices 12 used in the heating use area is zero, that is, when the entire display chamber 11 is the cooling use area, the empty evaporating dish during the cooling operation is used. Perform heating control. In this empty-fired evaporating dish heating control, regardless of whether or not the defrosting operation is performed, the control device C, when the counting time reaches a predetermined time by the timer 42 during the cooling operation, for example, when 30 minutes have elapsed, Executes the empty detection operation. That is, as shown in FIG. 6, the controller C energizes the heater 51 of the evaporating dish 32 every predetermined time, and is detected by the evaporating dish temperature sensor 52 per Δt time (unit time) at this time. The gradient of temperature rise is calculated from the temperature difference ΔT.

  When the calculated temperature increase gradient is not less than a predetermined value and is steep, the control device C determines that there is no drain water in the evaporating dish 32 and that the evaporating dish heater 51 is empty. Is de-energized. In the same manner as described above, the heater 51 is not de-energized until the predetermined protection time elapses after the evaporating dish heater 51 is energized, and is de-energized after the elapse of the time. Then, the count of the timer 42 is reset, and a new count is started. And if the said predetermined time passes, the control apparatus C will energize the heater 51 again, and will perform an empty detection operation.

  On the other hand, the control device C determines that there is drain water in the evaporating dish 32 when the calculated gradient of the temperature rise is less than a predetermined value and is slow in the airing detection operation. In this case, when the evaporating dish heater 51 is energized, the temperature increase gradient per unit time is calculated in the same manner as described above, and when the gradient becomes a predetermined value or more steep, the control device C is placed in the evaporating dish 32. It is determined that there is no drain water, and the state is empty, and the emptying evaporating dish heating control is terminated (interrupted), and the evaporating dish heater 51 is deenergized.

  Thus, in the empty-fired evaporating dish heating control, the control device C ends the heating control by the evaporating dish heater 51 when the gradient becomes equal to or greater than a predetermined value. Based on this, the energization of the evaporating dish heater 51 can be stopped at the time when it is determined that there is no drain water and the water is empty.

  Therefore, in spite of the fact that drain water remains in the evaporating dish 32, the inconvenience that the empty evaporating dish heating control ends, and even though drain water has already disappeared in the evaporating dish 32, It is possible to continue the empty-cooked evaporating dish heating control and avoid the disadvantage that wasteful power is consumed.

(When only the shelf device 12A is used as a heating use area and the other is used as a cooling use area)
Next, in the flowchart of FIG. 4 described above, when the number of shelves used as the heating use area is not 0 in step S1, the process proceeds to step S4. Here, it is determined whether or not the number of shelves used as the internal heating use area of the shelf device 12 currently set on the control panel 46 is one. As described above, when the inside of the display chamber 11 above the uppermost shelf apparatus 12A is a heating use area and the inside of the display room 11 below the shelf apparatus 12A is a cooling use area, the process goes to step S5. In the same manner as in step S2, the empty evaporating dish heating control during the cooling operation is executed. Next, the control device C proceeds to step S6, and executes the defrosting evaporating dish heating control accompanying the defrosting operation as in step S3. In addition, since the empty-boiled evaporating dish heating control in step S5 and the defrosting evaporating dish heating control in step S6 are the same as those in step S2 and step S3, description thereof is omitted.

(When the shelf devices 12A and 12B are used as heating areas, and the other shelf devices 12 are used as cooling areas)
If the number of shelves used as the heating use area is not 1 in step S4, the process proceeds to step S7. Here, it is determined whether or not the number of shelves currently used as the internal heating use area of the shelf device 12 set on the control panel 46 is two. As described above, when the inside of the display chamber 11 above the shelf device 12B in the second stage from the top is the heating use region, and the inside of the display chamber 11 below the shelf device 12B is the cooling use region, Since there are two shelf devices to be used in the heating area, the shelf devices 12A and 12B, the process proceeds to step S8, and the empty-boiled evaporating dish heating control during the cooling operation performed in step S2 is not executed. . Next, the control device C proceeds to step S9, and executes the defrosting evaporating dish heating control accompanying the defrosting operation as in step S3. In addition, since the evaporating dish heating control at the time of defrosting in step S9 is the same as that of said step S3, description is abbreviate | omitted.

(When shelf devices 12A, 12B, and 12C are used as heating areas, and other shelf devices 12D are used as cooling areas)
If the number of shelves used as the heating use area is not 2 in step S7, the process proceeds to step S10. Here, it is determined whether or not the number of shelves used as the internal heating use area of the shelf device 12 currently set on the control panel 46 is three. As described above, when the inside of the display chamber 11 above the shelf device 12C at the second stage from the bottom is the heating use region, and the inside of the display chamber 11 below the shelf device 12C is the cooling use region, Since the shelf devices 12 to be used in the heating area are the three shelf devices 12A, 12B, and 12C, the process proceeds to step S11, and the empty-boiled evaporating dish heating control during the cooling operation performed in step S2 is not executed. Shall. Next, the control device C proceeds to step S12, and the defrosting evaporating dish heating control accompanying the defrosting operation performed in step S3 is not executed.

  In the present embodiment, when the number of shelves used as the heating use area is 4, the entire interior of the display room 11 is used as the heating use area in step S13, so that the cooling device R operates. It has stopped. For this reason, since the frost formation to the evaporator 15 does not arise, each said evaporating dish heating control becomes unnecessary.

  Thus, according to the ratio of the heating use area and the cooling use area in the display chamber 11, in this embodiment, the number of the shelf devices 12 in the heating use area in the display chamber 11, It is determined whether or not to perform the emptying prevention evaporating dish heating control.

  And when the ratio of the cooling use area | region in the display chamber 11 is large, ie, when the number of the shelf apparatuses 12 of the heating use area | region in the display chamber 11 is small (in fact, the whole display chamber 11 is made into a cooling use area | region. And when the upper shelf unit 12A is used as the heating use area and the lower side is used as the cooling use area), the evaporating dish heating control during defrosting and the emptying prevention evaporating dish heating control are executed. . In this case, since the ratio of the cooling use area in the display chamber 11 is large, the circulation amount of air in the cooling use area increases, so that the amount of frost formation on the evaporator 15 increases, and accordingly, the evaporation tray 32 The amount of drain water that is accepted increases.

  In such a case, by performing evaporating dish heating control during defrosting and emptying prevention evaporating dish heating control, it becomes possible to smoothly evaporate the drain water in the evaporating dish 32 and evaporate during the cooling operation. It is possible to avoid an inconvenience that drain water overflows from the dish 32 and an increase in power consumption due to excessive heating.

  On the other hand, as the ratio of the heating usage area in the display chamber 11 increases, that is, as the number of the shelf devices 12 in the heating usage area in the display chamber 11 increases, the amount of air circulation in the cooling usage area decreases. As a result, the amount of frost formed on the evaporator 15 and further the amount of drain water received in the evaporating dish 32 decreases.

  When the ratio of the cooling use area and the heating use area in the display chamber 11 is substantially the same as in this embodiment, only the evaporating dish heating control at the time of defrosting is executed and the emptying prevention evaporating dish at the cooling operation is executed. Heating control is not executed.

  As a result, the drain water can be smoothly and appropriately evaporated only by performing the heating control by the evaporating dish heater 51 only during the defrosting in which more drain water is received in the evaporating dish 32 than in the cooling operation. Can be realized.

  Thereby, as the number of shelf devices 12 in the heating use area increases, the energization amount to the shelf heater 22 provided in the shelf device 12 increases, but by reducing the total energization amount to the evaporating dish heater 51. Further, it is possible to realize energy saving as compared with the conventional case (when the heating control of the evaporating dish heater is performed without being limited to the number of shelves).

  Further, in this embodiment, when the ratio of the heating use area in the display chamber 11 is larger, that is, when the number of the shelf devices 12 in the heating use area in the display chamber 11 is larger (here, two stages from the bottom). In the case where the inside of the display chamber 11 above the eye shelf device 12C is used as a heating use area and the lower side is used as a cooling use area), the ratio of the cooling use area becomes small, and the circulation amount of air in the cooling use area is reduced. Further, the frosting on the evaporator 15 is further reduced. Therefore, the amount of drain water received in the evaporating dish 32 is reduced, and evaporation can be sufficiently promoted by natural evaporation or waste heat from the machine room 25.

  Therefore, the drain water in the evaporating dish 32 can be processed smoothly without executing the evaporating dish heating control at the time of defrosting or the emptying prevention evaporating dish heating control, and the conventional case (not limited to the number of shelves). Energy saving can be realized as compared to the case where the heating control of the evaporating dish heater is performed.

  In particular, in the present embodiment, the evaporating dish 32 is provided with an evaporating plate 53 for promoting evaporation, so that smooth drain water treatment can be realized without performing heating control by the evaporating dish heater 51. Can do.

  Moreover, when the ratio of the heating use area | region in the display chamber 11 is large, although the energization amount to each shelf heater 22 becomes large, since the ratio of a cooling use area | region becomes small, the amount of frost formation to an evaporating dish is small. Accordingly, the energization capacity of the evaporator heater 51 can be reduced and further reduced accordingly. Therefore, it is possible to reduce the amount of current that is simultaneously applied to the entire showcase 1, so that the current capacity of the entire showcase 1 can be reduced. Therefore, the production cost can be reduced by reducing the rated current of the device itself.

  In the present embodiment, the number of shelves installed in the display room 11 is four, but the present invention is not limited to this. Here, the ratio between the cooling use area and the heating use area can be arbitrarily changed by the shelf device and the damper member 39 provided on the shelf apparatus. However, the ratio is not limited to this, and other methods, for example, display Even if the room is partitioned by a partition wall or the like and the ratio of the cooling use area and the heating use area can be changed, the same effect can be obtained.

  In the above embodiment, the open showcase 1 is described as an example. However, the present invention is not limited to this, and a cooling use area and a heating use area are configured in the display room (or storage room). The same effect can be achieved even if the showcase is made possible.

It is a perspective view of the showcase of the Example to which this invention is applied. It is a vertical side view of the showcase of FIG. It is an electrical block diagram of a control apparatus. It is a flowchart which determines the presence or absence of the evaporating dish heating control according to the number of the shelf apparatuses of a heating use area | region. It is a timing chart of the heater of the evaporating dish accompanying a defrost operation. It is a timing chart of the heater in the empty detection operation.

Explanation of symbols

R Cooling device C Control device 1 Showcase 11 Display room 12, 12A, 12B, 12C, 12D Shelf device 15 Evaporator 19 Blower for cold air circulation 22, 22A, 22B, 22C, 22D Shelf heater (electric heater)
25 Machine room 26 Compressor 32 Evaporating dish 36 Shelf duct 39 Damper member 39A, 39B, 39C Damper sensor (damper open / close detection means)
42 Timer 43 Discharge cold air temperature sensor 44 Defrosting end temperature sensor 45 Shelf sensor 46 Control panel 51 Evaporating dish heater (electric heater)
52 Evaporating dish temperature sensor 53 Evaporating plate

Claims (2)

A shelf heater for heating a shelf installed in the display room;
An evaporator for cooling the display chamber,
In the showcase in which the heating use area heated by the shelf heater and the cooling use area cooled by the evaporator can be configured in the display room, and the ratio of these areas can be changed,
An evaporating dish for receiving drain water from the evaporator or the like;
An evaporating dish heater for heating the evaporating dish;
A temperature sensor for detecting the temperature of the evaporating dish or drain water in the evaporating dish;
A controller for controlling energization of the evaporating dish heater based on the output of the temperature sensor,
The controller is a defrosting evaporating dish heating control that energizes the evaporating dish heater to evaporate drain water in the evaporating dish when the evaporator defrosts;
Energize the evaporating dish heater every predetermined time, determine the presence or absence of drain water in the evaporating dish according to the temperature gradient at that time, and energize the evaporating dish heater when it is determined that there is drain water It is possible to execute an emptying prevention evaporating dish heating control for evaporating drain water in the evaporating dish,
Whether to execute the defrosting evaporating dish heating control and the emptying prevention evaporating dish heating control according to the ratio of the heating use area and the cooling use area in the display room is determined. .   The control device executes the defrosting evaporating dish heating control and the emptying prevention evaporating dish heating control when the ratio of the cooling use area in the display room is large, and the ratio of the heating use area is increased. The showcase according to claim 1, wherein the evaporating dish heating control at the time of defrosting or the emptying prevention evaporating dish heating control or both of them are not executed according to the above.

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