JP2008151452A - Storage device and its temperature control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a showcase capable of stably controlling the temperature in a display compartment. <P>SOLUTION: In the showcase 1 having the display compartment 3, a supply duct 21, a suction duct 22, and a connection duct 23 connecting the suction duct 22 and the supply duct 21, and incorporating at least an evaporator 31 and an air distribution fan 32, an air speedometer 37 detecting the air volume F of cold air A is disposed, and the fan is controlled so that an output of the air distribution fan 32 is increased when the air volume F is reduced. By restraining the reduction of air volume of the cold air, the temperature in the display compartment can be stably controlled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a storage device such as a showcase suitable for displaying products in a cooled or frozen state, and a temperature control method therefor.

  Patent Document 1 discloses a temperature control device for a showcase, which detects a temperature inside a chamber using a temperature sensor, and a thermo differential set with a predetermined width up and down with respect to a set value of the chamber temperature. It is described that the opening / closing drive of the solenoid valve in the refrigeration cycle is controlled via the valve drive unit of the solenoid valve according to the comparison result.

Patent Document 2 discloses that among the showcases, the open showcase has a large opening of heat from the opening on the front, and the flat showcase has a large penetration of heat from the opening on the top. It is stated that it is extremely unstable to do. Therefore, a temperature sensor is inserted in the cool air passage that is separated from the inside where the product is actually stored and has little temperature influence from the outside, and the temperature of the discharged cool air discharged into the store is detected. It is described that the compressor is controlled by comparing the temperature and the set temperature to control the temperature.
JP 2003-207246 A JP 2005-337653 A

  For storage devices that need to form an air curtain, such as an open showcase, or storage devices that need to circulate cold air to reduce the temperature distribution in the display room, even if the room temperature falls below the set value The supply of cold air cannot be stopped. Therefore, the cooling capacity of the evaporator, which is the cooling unit, is controlled by turning on / off the compressor or adjusting the flow rate of the refrigerant. When the evaporator is in a frosted or icing state, the pressure loss increases, so that the amount of air passing through the evaporator is reduced and the temperature of the discharged cold air may be lowered. In such a case, if you try to control the temperature with the temperature of the discharged cold air, the air volume will be reduced more or the capacity of the refrigeration cycle will be reduced, which may make it impossible to maintain the internal temperature. . On the other hand, if the temperature is controlled by the internal temperature, the cooling capacity of the evaporator is increased in order to lower the temperature of the cold air when the internal temperature rises, so that frosting progresses and the air volume of the cold air decreases. Therefore, it becomes difficult to maintain the temperature in the cabinet, and the time until defrosting is shortened.

  One aspect of the present invention includes a display room for displaying commodities in a refrigerated and / or frozen state, a duct system including at least a cooling unit for supplying cold air to the display room and a fan for blowing air, It is a storage device having a control unit including a control function for repeating a cool air supply mode for supplying cool air to the display room and a defrost mode for defrosting the cooling unit. The control unit includes a fan control function for controlling the output of the blower fan at the end of the cool air supply mode to be larger than the output of the blower fan at the start of the cool air supply mode. One way to increase the output of the fan for blowing air is to increase the rotational speed of the fan. One of the other methods for increasing the output of the fan for blowing air is to prepare a plurality of fans for blowing air and increase the number of operating fans. It is also possible to increase the output of the fan for blowing air by controlling the flow rate control element on the suction side and / or the discharge side of the fan, for example, the opening degree of the damper.

  When the cooling unit is frosted, the pressure loss increases if the output of the blower fan is constant. Therefore, the amount of cool air supplied from the duct system at the end of the cool air supply mode is smaller than the amount of air at the start of the cool air supply mode. Further, when the air volume passing through the cooling unit decreases, the temperature of the cold air decreases. Therefore, if the temperature of the cool air is simply made constant, the temperature of the display room rises. In addition, when the temperature of the display room is made constant, it is necessary to lower the temperature of the cold air, so that frosting proceeds.

  In this storage device, the fan control function makes the output of the blower fan at the end of the cool air supply mode larger than the output of the blower fan at the start of the cool air supply mode. Therefore, it is possible to prevent the amount of cool air supplied from the duct system at the end of the cool air supply mode from being smaller than the amount of air at the start of the cool air supply mode. For this reason, it is easy to maintain the temperature of the display room by controlling the temperature of the cold air to be constant. In addition, if the display room temperature is kept constant, there is no need to greatly change the cooling capacity of the cooling unit, so that the progress of frost formation can be delayed and the timing of defrosting can be delayed to supply cold air. You can extend the time.

  One method for controlling the cooling capacity of the cooling unit in a cool air circulation type storage device that cools all or part of the air in the display room and returns it to the display room as cold air is to use the intake air temperature as a control element (target). Is. The duct system includes a suction duct for sucking air from the display room, and a temperature sensor for detecting the temperature of the intake air in the suction duct, and the control unit cools the cooling unit according to the temperature detected by the temperature sensor. It is preferable to further have a function of controlling.

  One mode for making the fan output at the end of the cool air supply mode larger than the fan output at the start of the cool air supply mode by the fan control function is that It is to change the output of the fan. That is, the fan control function can increase the output of the fan for blowing according to the elapsed time of the cold air supply mode.

  Another form for the fan control function to make the output of the fan for blowing air at the end of the cool air supply mode larger than the output of the fan for blowing air at the start of the cold air supply mode is Detecting and thereby changing the output of the fan for blowing. That is, by providing the storage device with a sensor for detecting the air volume downstream of the cooling unit, the fan control function increases the output of the fan for blowing so that the air volume detected by the sensor is constant. be able to. The sensor for detecting the air volume is, for example, an anemometer, and there is a sensor that measures the wind pressure (differential pressure) of a Pitot tube or the like, and a sensor that measures the rotational speed of the windmill.

  In this fan control function, the output of the fan for blowing may be continuously controlled by decreasing the elapsed time (service time) or the air volume, and the output of the fan for blowing may be increased stepwise. The fan control function and the function of controlling the cooling capacity of the cooling unit based on the intake air temperature are more easily coordinated when the output of the fan for blowing is controlled stepwise.

  It is preferable that the cooling unit includes an evaporator including a plurality of pipe portions, and intermittent fins having a shape intermittent in the longitudinal direction and the circumferential direction protrude in the radial direction of each pipe portion. Such a tube is also called a spine fin type tube, and frost or ice adheres to the tip of the fin and grows. Therefore, unlike a plate fin or a corrugated fin, there is little possibility of clogging between the fins, and by increasing the output of the fan for blowing air, it is easy to improve the air volume and to ensure a service period until defrosting .

  The fan control function is suitable for an open showcase in which a part of the display room is opened. One form thereof is a flat showcase having a substantially U-shaped cross-section in the display chamber, with the display chamber open above. In this showcase, the supply port of the supply duct and the suction port of the suction duct included in the duct system are arranged at the upper part of the facing wall of the display room.

  Another aspect of the present invention is the above-described temperature control method for a storage device, in which a cool air supply mode for supplying cool air to the display room and a defrost mode for defrosting the cooling unit are repeatedly performed. . This control method includes a fan control step for controlling the output of the blower fan at the end of the cool air supply mode to be larger than the output of the blower fan at the start of the cool air supply mode. As described above, the temperature control characteristics of the storage device can be improved by increasing the fan output so as to restore the air volume or by increasing the air volume. Further, by increasing the fan output and securing the air volume of the cool air, the state of the air curtain can be improved in the open showcase. For this reason, the state in a display room can be improved and the quality degradation of the goods currently displayed can be prevented.

  The temperature control method preferably further includes a step of controlling the cooling capacity of the cooling unit based on the temperature detected by the temperature sensor that detects the intake air temperature in the suction duct. In addition, in the fan control process, the temperature difference becomes larger than a predetermined value, so that the output of the blower fan is increased stepwise in that the cooperative control with the process of controlling the cooling capacity of the cooling unit is easy. It is desirable.

  FIG. 1 is a sectional view showing a schematic configuration of a storage device according to an embodiment of the present invention. This storage device 1 is an open type frozen showcase suitable for storing and displaying ice cream, frozen foods, etc., and is a flat type (flat rectangular parallelepiped shape) with a floor-standing type and an opening 2 at the top. The center of the housing 10 is a display chamber (storage space, storage area, storage) 3 having a substantially U-shaped cross-section with the top open. The showcase 1 further includes a duct system 20 that supplies cool air A to the display room 3 and sucks air B from the display room 3. The duct system 20 includes an inner wall 5 that constitutes the display room 3, , Between the housing 10.

  The duct system 20 includes a supply duct 21 for supplying cold air (supply air) A to the display chamber 3, a suction duct 22 for sucking air (intake air) B from the display chamber 3, a suction duct 22 and a supply duct. The connecting duct 23 is connected to the connecting duct 23. The connection duct 23 incorporates an evaporator 31 that is a cooling unit for cooling the intake air B, and a blower fan (blower fan) 32 for supplying the cool air A to the display chamber 3 by the duct system 20. Yes. The blower fan 32 is driven by a motor 32m, and the air volume can be controlled by changing the rotation speed of the motor 32m. The connection duct 23 extends along the bottom 5b on the opposite side of the bottom 5b of the inner wall 5 constituting the display chamber 3, and the supply duct 21 and the suction duct 22 are the side portions (side walls) 5a and 5c of the inner wall 5. Standing up along. The supply duct 21 and the suction duct 22 are respectively connected to a supply port 25 and a suction port 26 provided at the upper portions of the opposing side walls 5a and 5c, supply cold air A, and suck air B from the display chamber 3. An air curtain can be formed in the upper opening of the display chamber 3. An anemometer (Pitot tube) 37 for measuring the air volume is disposed inside the supply duct 21, and the temperature of the intake air B is measured near the suction port 26 inside the suction duct 22. Temperature sensor 34 is arranged.

  The showcase 1 further includes a heat exhaust portion 40 disposed below the connection duct 23. The exhaust heat unit 40 includes a compressor 41 for compressing the refrigerant supplied to the evaporator 31, a condenser 42 for cooling the compressed refrigerant, and a heat radiation for cooling the condenser 42 by introducing outside air. And a fan 43. The exhaust heat unit 40 is provided with a drain pan 44 for self-evaporating the drain so that the drain can be received from the connection duct 23 through the drain pipe 39.

  The showcase 1 further includes electric heaters 33a and 33b for defrosting disposed on the bottom surface 23b of the connection duct 23. The electric heater 33 a is disposed in a region on the lower side of the evaporator 31 in the bottom surface 23 b of the connection duct 23. The electric heater 33 b is disposed upstream of the blower fan 32 in the bottom surface 23 b of the connection duct 23. Below the evaporator 31 on the bottom surface 23b of the connection duct 23 is an area where frost or ice generated in the evaporator 31 is likely to accumulate. In particular, in an open-type showcase (open showcase) in which a part of the display chamber 3 has an opening 2, an air curtain is formed in the opening 2. At that time, not only the cold air A but also the outside air Also inhale. For this reason, the moisture contained in the outside air becomes frost or ice and adheres to or accumulates on the evaporator 31 or the like. The adhering frost or ice hinders heat transfer, causes pressure loss to reduce the opening area in the duct, and causes a reduction in the air volume of the cold air A supplied to the display chamber 3. Therefore, it is necessary to perform a defrosting operation for removing frost and / or ice under conditions such as a significant decrease in air volume and / or periodically.

  FIG. 2 shows the refrigerant cycle and control configuration of the showcase 1. The showcase 1 has a refrigerant cycle 45 including a compressor 41, a condenser 42, and an evaporator 31. The refrigerant cycle 45 further includes an expansion valve 46 for expanding the refrigerant compressed by the compressor 41 and cooled by the condenser 42 and supplying the refrigerant to the evaporator 31, and before being compressed by the compressor 41 and cooled by the condenser 42. And a hot gas bypass valve 35 for guiding the refrigerant (hot gas) to the evaporator 31. The hot gas bypass valve 35 is opened when the evaporator 31 is defrosted, and is closed in a normal service state in which cold air is supplied.

  The showcase 1 further includes a control unit 50 having a function of controlling the fan 32 (fan motor 32m) for blowing air, the compressor 41, the fan 43 for exhaust heat, the hot gas bypass valve 35, and the electric heaters 33a and 33b. Have. The control unit 50 is further connected to the anemometer 37 and the temperature sensor 34. For this reason, the control unit 50 can control each device described above with reference to the air volume F of the cold air A and the temperature tb of the intake air B.

  The control unit 50 includes a cold air supply control function 51 that controls the cold air supply mode and a defrost control function 52 that controls the defrost mode. In the cold air supply mode, as shown in FIG. 2, the blower fan 32, the exhaust heat fan 43 and the compressor 41 are turned on, the hot gas bypass valve 35 is closed, and the electric heaters 33a and 33b are turned off. It becomes. Therefore, the air B sucked from the suction port 26 by the suction force of the blower fan 32 is guided to the connection duct 23 via the suction duct 22 and cooled by the evaporator 31. Then, the cooled air (cold air, cold air) A is supplied from the supply port 25 to the display chamber 3 through the supply duct 21 to cool the display chamber 3. The cold air A is also sucked from the suction port 26 as the intake air B, thereby forming an air curtain in the opening 2.

  The cold air supply control function 51 further includes a fan control function 55 and a compressor control function 56. The fan control function 55 controls the output of the blower fan 32 by changing the rotation speed of the fan motor 32m according to the air volume F. Specifically, when the air volume F becomes equal to or less than the set value F0, the rotational speed of the fan motor 32m is increased stepwise, and the output of the blower fan 32 is improved stepwise. When the pressure loss increases due to the frost or icing of the evaporator 31, the air volume of the cold air A supplied from the duct system 20 to the display chamber 3 is secured or increased by increasing the output of the blower fan 32. Can be.

  The compressor control function 56 turns on and off the compressor 41 according to the intake air temperature tb, and controls the cooling capacity of the evaporator 31. Specifically, the compressor 41 is turned off when the intake air temperature tb is a set value (TB−Tb) or lower, and the compressor 41 is turned on when the intake air temperature tb is higher than or equal to the set value TB. The compressor control function 56 is a function for setting the width (thermo differential) Tb in the vertical direction and controlling the compressor 41 on and off with the intake air temperature tb as a control target.

  In the defrost mode, the defrost control function 52 stops the blower fan 32, drives the exhaust heat fan 43 and the compressor 41, opens the hot gas bypass valve 35, and heats the evaporator 31. Further, by turning on (energizing) the electric heaters 33a and 33b, a place where frost formation or icing is likely to occur such as the bottom surface 23b of the connection duct 23 is heated. The frost or ice adhering to and / or depositing on the evaporator 31 is melted and drained. These drains pass through the bottom surface 23 b of the connection duct 23 and are collected in the drain pan 44 through the drain pipe 39. Further, frost or ice adhering to and / or depositing on the suction duct 22 and the connection duct 23 is melted and drained. At this time, since the blower fan 32 is stopped, the air flow (forced flow) inside the duct system 20 including the suction duct 22, the connection duct 23, and the supply duct 21 stops, and the display chamber 3 has no duct. Neither cold air nor hot air is supplied from the system 20.

  In the defrost mode, the defrost control function 52 melts frost and / or ice by the above control for a predetermined time, for example, about 15 minutes. Thereafter, the defrost control function 52 stops the compressor 41, closes the hot gas bypass valve 35, turns off the electric heaters 33a and 33b, drives the blower fan 32, and drains water for about 2 minutes. Thereafter, the flow again enters the cold air supply mode. Thereby, the cool air A is supplied from the duct system 20 to the display chamber 3, and the display chamber 3 is cooled. This showcase 1 repeats an 8-hour cold air supply mode and a defrosting mode of about 17 minutes including draining to maintain the inside of the display chamber 3 at a low temperature.

  FIG. 3 is a flowchart showing temperature control in the showcase 1. When the showcase 1 is activated, the cold air supply control function 51 resets a timer for measuring a service time (elapsed time in the cold air supply mode) W in the initial setting of step 71, turns on the compressor 41, and is a cooling unit. A refrigerant is supplied to the evaporator 31. Further, the cool air supply control function 51 sets the rotation speed of the fan motor 32m to a low speed, turns on the fan motor 32m, and starts a service for supplying the cool air A from the duct system 20 to the display chamber 3.

  In step 72, when a predetermined service time W (for example, 8 hours) elapses in the cold air supply mode, the process moves to the defrost mode in step 73, and the defrost control function 52 operates. The timing for shifting to the defrosting mode may be managed by the service time W, or may be managed by factors such as a decrease in the air volume of the cold air A supplied from the supply duct 21. As will be described later, the fan control function 55 controls the airflow to be increased by increasing the output of the blower fan 32 in a stepwise manner (one stage or multiple stages) when the air volume F of the cold air becomes equal to or less than the set value F0. However, even when the output of the blower fan 32 is set to the maximum, the defrosting mode may be shifted to when the air volume F of the cool air becomes the set value F0 or less.

  The defrost control function 52 stops the blower fan 32, opens the hot gas bypass valve 35, and turns on the heaters 33a and 33b. When a predetermined defrosting time, for example, 15 minutes elapses, draining is performed for a predetermined time, for example, 2 minutes. Thereafter, the timer for measuring the service time (elapsed time) W in the cold air supply mode is reset, and the mode is shifted to the cold air supply mode. That is, the cold air supply control function 51 turns on the compressor 41, drives the fan motor 32m with the rotation speed set to a low speed, and restarts the supply of cold air.

  In step 74, when the intake air temperature tb becomes equal to or lower than the set temperature (TB-Tb), in step 75, the compressor control function 56 turns off the compressor 41. Thereby, supply of the refrigerant | coolant to the evaporator 31 which is a cooling unit stops, the cooling capability of a cooling unit is reduced, and the indoor temperature of the display chamber 3 is prevented from becoming too low.

  When the intake air temperature tb becomes equal to or higher than the set temperature TB in step 76, the compressor control function 56 turns on the compressor 41 in step 77. Thereby, since the supply of the refrigerant to the evaporator 31 which is the cooling unit is resumed, the cooling capacity of the cooling unit is increased. Therefore, it is possible to prevent the indoor temperature of the display chamber 3 from becoming too high.

  In step 78, when the air volume F of the cold air A becomes equal to or less than the set air volume F0, in step 79, the fan control function 55 increases the rotation speed of the fan motor 32m by one step. As a result, the output of the blower fan 32 is increased by one stage, and the amount of air passing through the evaporator 31 is increased (fan control process).

  For example, when the evaporator 31 is frosted or iced (hereinafter referred to as frosting including icing), the pressure loss increases, and the amount of air passing through the evaporator 31 decreases. As a result, the temperature of the cold air A decreases and the air volume F also decreases. In this state, since the supply amount of the cold air A is reduced, the temperature of the display chamber 3 rises and the intake air temperature tb rises as time elapses.

  If the temperature control is performed only by the compressor control function 56 without operating the fan control function 55, the intake air temperature tb becomes difficult to decrease due to a decrease in the supply amount (air volume) of the cold air A. For this reason, the compressor control function 56 prevents the compressor 41 from being repeatedly turned on and off and is likely to be continuously operated, so that the frosting on the evaporator 31 proceeds. For this reason, the air volume F of the cold air A further decreases, the temperature of the display chamber 3 rises, and the temperature of the product stored in the display chamber 3 also rises, so that the quality deteriorates. In order to eliminate this state, it is necessary to defrost, and if defrosting is repeated frequently, the temperature change of the display chamber 3 tends to become large, and it becomes difficult to maintain the quality of the product. Furthermore, since the compressor 41 tends to be continuously operated and the power consumed for defrosting increases, the power consumption tends to increase.

  On the other hand, when the fan control function 55 is operated, when the air volume F of the cool air decreases, the rotation speed of the fan motor 32m increases, and the decrease in the supply amount (air volume) of the cool air A is suppressed. Alternatively, the air volume F of the cold air A can be increased. By increasing the air volume F of the cold air A, the temperature (cold air temperature) ta of the cold air increases and the intake air temperature tb decreases. Since the intake air temperature tb decreases, the compressor control function 56 controls the temperature of the display chamber 3 by repeatedly turning the compressor 41 on and off. The progress of frost formation on the evaporator 31 is delayed, and the decrease in the air volume F of the cold air A can be suppressed. Therefore, the temperature rise of the display chamber 3 can be suppressed at an early stage for a long time, and the quality of the product can be easily maintained. In addition, the time period during which the defrosting interval is extended and the cold air A can be continuously supplied becomes longer, and during that time, the compressor 41 can be controlled on and off, so that power consumption can also be reduced.

  FIG. 4 is an enlarged cross-sectional view showing a part of the configuration of the evaporator 31. The evaporator 31 is a spine fin type heat exchanger in which a tube (spine fin tube) 69 including a spine fin 64 is bent in a direction crossing the connection duct 23 to form a plurality of pipe portions 66. Therefore, from each tube main body 62, the spine fin 64 of the shape interrupted in the longitudinal direction and the circumferential direction protrudes in the radial direction. The spine fin tube 69 can be manufactured by cutting a plate material into a strip shape, and winding a band-like member obtained by bending the plate material into a bowl shape around the tube body 62 as a fin 64 and joining them.

  The distance between the spine fins 64 is narrow at the root (the tube body 62 side) and wide at the tip. Therefore, in the evaporator 31 employing the spine fin tube 69, even if frosting or icing progresses, the tips of the fins 64 are widened so that they are not easily blocked, and the air volume F of the cold air A is unlikely to drop rapidly. Further, since clogging due to frost or ice is difficult to proceed rapidly, the air volume F of the desired cold air A can be secured or increased by increasing the output of the blower fan 32 and increasing the air volume F. Therefore, coupled with the fan control function 55 described above, the defrosting interval can be extended and the supply time (service time) of the cold air can be extended.

  FIG. 5 is a flowchart showing a different embodiment of the temperature control in the showcase 1. In this temperature control method (control method), instead of measuring the air volume F of the cold air A, the output of the blower fan 32 is increased by the elapsed time (service time) W of the cold air supply mode, and the decrease in the air volume F is suppressed. . In the control method shown in FIG. 5, steps 71 to 77 are the same as the control method shown in FIG.

  In step 80, when the service time W becomes equal to or longer than the set time W0, the fan control function 55 increases the rotational speed of the fan motor 32m by one step in step 79. As a result, the output of the blower fan 32 is increased by one stage, and the amount of air passing through the evaporator 31 is increased (fan control process).

  In the showcase 1 that repeats cold air supply and defrosting, if the installation location does not change and the stored product does not change, the state in which the frosting of the evaporator 31 proceeds generally does not change significantly. The installation location of the showcase 1 is in a store that is air-conditioned. If the air-conditioning setting does not change, the environment around the showcase 1 does not change so much throughout the season. Further, even if the conditions of the heat load such as the illumination load change depending on the day and night, the cold air supply / defrost cycle can be adjusted to the 24-hour cycle. Moreover, the conditions of the display room 3 change with the goods accommodated in the display room 3, and the conditions of the display room 3 change a lot depending on whether the goods are for refrigeration or freezing. However, since the merchandise to be displayed is determined to some extent and the timing at which the merchandise is replenished is also determined by a 24-hour cycle, the progress of frost formation in the cool air supply mode can be achieved by matching the cold air supply-defrost cycle to the 24-hour cycle. Is easy to predict.

  Therefore, in this temperature control method, a change in the air volume F is predicted based on the service time W, the timing at which it is desirable to restore the air volume F is set as the set time W0, and the output of the blower fan 32 is controlled. Therefore, a sensor for measuring the air volume such as the anemometer 37 can be omitted. And as demonstrated based on FIG. 3, the conditions of the display chamber 3 can be stabilized, the fall of the quality of goods can be prevented, and service time W can be extended further.

  In the above, the fan control function 55 increases the output speed of the blower fan 32 by increasing (fastening) the rotational speed of the fan motor 32m. The system for controlling the output of the blower fan 32 is not limited to this. Instead of changing the rotational speed of the fan motor 32m, the rotational speed of the blower fan 32 may be controlled using a fluid coupling or the like. Moreover, you may control the substantially total output of the ventilation fan 32 by installing the several ventilation fan 32 and changing the operating number of the ventilation fans 32. FIG. Furthermore, elements for controlling the air volume, such as dampers and vanes, may be installed at appropriate locations in the duct system 20.

  In addition, the fan control function 55 described above may change the output of the blower fan 32 not only in one stage but in multiple stages. Every time the air volume F becomes equal to or less than the set value F0, the output of the blower fan 32 can be increased stepwise. The fan control function 55 may continuously control the output of the blower fan 32 so that the air volume F of the cold air A becomes constant. However, there is a possibility that the output of the blower fan 32 may pulsate when the compressor control function 56 controls the on / off of the compressor 41 by the intake air temperature tb. Therefore, in order to cooperatively control the fan control function 55 and the compressor control function 56, it is preferable to change the output of the blower fan 32 in stages.

  In the showcase 1 described above, the evaporator 31 is used as a cooling unit, and the compressor 41 that supplies the refrigerant to the evaporator 31 is turned on / off by the compressor control function 56 to control the cooling capacity of the cooling unit. Instead of the on / off control of the compressor 41, the supply amount of the refrigerant to the evaporator 31 may be controlled by a valve or the supply of the refrigerant may be controlled on / off. A plurality of evaporators 31 may be provided to control the number of evaporators to which the refrigerant is supplied. Furthermore, in the small showcase 1, it is possible to employ a cooling unit of a type that absorbs heat by a Peltier element instead of the evaporator 31. In this case, the cooling capacity can be controlled by controlling the number of operating Peltier element units or controlling the voltage applied to the Peltier elements.

  Furthermore, in the above, the present invention has been described by taking a flat-type open showcase as an example. However, the present invention is not limited to a flat-type, and may be an open showcase having a front or back opened. Furthermore, the present invention can also be applied to a closed type or semi-closed type refrigerated or frozen showcase having a display room (storage room, storage room) that can be opened and closed by a door or the like. As a result, the temperature change in the display room can be suppressed, and the quality deterioration of the products stored in the display room can be prevented. Moreover, the defrosting interval can be set long, and the supply time of cold air can be set long.

Sectional drawing which shows schematic structure of a flat type showcase. The figure which shows the refrigerant cycle and system configuration | structure of the showcase shown in FIG. It is a flowchart which shows the temperature control method of the showcase shown in FIG. Sectional drawing which expands and shows the structure of an evaporator. It is a flowchart which shows the example from which the temperature control method of a showcase differs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Showcase, 3 Display room (storage area), 5 Inner wall of display room 10 Housing 20 Duct system, 21 Supply duct, 22 Suction duct, 23 Connection duct 25 Supply port, 26 Suction port 31 Evaporator, 32 Fan for ventilation ( Blower fan), 32m fan motor 33a, 33b heater (electric heater),
34 Temperature sensor, 37 Anemometer 41 Compressor, 42 Capacitor 50 Control unit

Claims (12)

A display room for displaying goods in a refrigerated and / or frozen state;
A duct system including at least a cooling unit for supplying cold air to the display room and a fan for blowing air;
A control unit including a control function for repeating a cool air supply mode for supplying cool air to the display room and a defrost mode for defrosting the cooling unit;
The control unit includes a fan control function for controlling the output of the blower fan at the end of the cool air supply mode to be larger than the output of the blower fan at the start of the cool air supply mode. The storage device. The duct system according to claim 1, comprising a suction duct for sucking air from the display chamber, and a temperature sensor for detecting a temperature of intake air in the suction duct.
The storage device further includes a function of controlling a cooling capacity of the cooling unit based on a temperature detected by the temperature sensor.   The storage device according to claim 1, wherein the fan control function increases an output of the fan for blowing air according to an elapsed time of the cold air supply mode. In Claim 1, it has a sensor for detecting the air volume of the downstream of the cooling unit,
The fan control function is a storage device that increases the output of the fan for blowing air so that the air volume detected by the sensor is constant.   3. The storage device according to claim 1, wherein the fan control function of the control unit increases the output of the fan for blowing in a stepwise manner.   6. The cooling unit according to claim 1, wherein the cooling unit includes an evaporator including a plurality of pipe portions, and intermittent fins that are intermittently formed in a longitudinal direction and a circumferential direction are provided in a radial direction of each pipe portion. A protruding storage device.   The storage device according to any one of claims 1 to 6, wherein the display chamber is a flat shape having a U-shaped cross section that opens upward. A temperature control method for a storage device having a display room for displaying goods in a refrigerated and / or frozen state,
The storage device further includes a duct system including at least a cooling unit for supplying cold air to the display room and a fan for blowing air,
In the temperature control method, when the cool air supply mode for supplying cool air to the display room and the defrost mode for defrosting the cooling unit are repeatedly performed, the temperature control method is used for the blowing at the end of the cool air supply mode. A temperature control method comprising: a fan control step of controlling so that an output of the fan becomes larger than an output of the fan for blowing at the start of the cold air supply mode. The duct system according to claim 8, comprising a suction duct for sucking air from the display chamber, and a temperature sensor for detecting a temperature of intake air in the suction duct.
The temperature control method further includes the step of controlling the cooling capacity of the cooling unit based on the temperature detected by the temperature sensor.   9. The temperature control method according to claim 8, wherein, in the fan control step, an output of the fan for blowing air is increased according to an elapsed time in the cold air supply mode. 9. The storage device according to claim 8, further comprising a sensor for detecting an air volume downstream of the cooling unit,
In the fan control step, the temperature control method of increasing the output of the fan for blowing air so that the air volume detected by the sensor is constant.   12. The temperature control method according to claim 8, wherein in the fan control step, the output of the fan for blowing air is increased stepwise.

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