JP2007263426A - Defrosting control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a defrosting control device, achieving energy saving by avoiding wasteful defrosting control in the case of peripheral environment where a frost formation amount to a cooling device is decreased. <P>SOLUTION: The defrosting control device includes: a control means (a centralized supervisory controller 20) for controlling the defrosting of a cooler 5. The control means (the centralized supervisory controller 20) performs defrosting operation of the cooler 5 based on a predetermined cycle, a predetermined time or a predetermined operation time. The control means (the centralized supervisory controller 20) does not perform the defrosting operation in a status where the absolute humidity is low based on the absolute humidity of the peripheral environment where a cooling device is low. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a cooling device that cools the inside of a warehouse with cold air that exchanges heat with a cooler.

  Conventionally, in an open type or closed type showcase installed in a store such as a supermarket or a convenience store, moisture in the surrounding air is cooled by the cool air of the showcase, and it is taken into the showcase so that the cooling part It is easy to get frost on the cooler. In particular, in an open showcase where the product display opening is always open, due to temperature differences and humidity differences from the surrounding air, not only the surrounding air was caught in the showcase cabinet from the opening. .

  In addition, when the goods displayed in the showcase are taken out, disturbance is added to the cold air, and the amount of the surrounding air from the opening increases. For this reason, moisture in the air appears in the form of frost on the inside of the showcase or on the cooler of the showcase. When frosting occurs in the cooler, the cooling load increases, so the operation of the cooling device is periodically stopped to perform the defrosting operation of the cooler (see Patent Document 1).

A large number of showcases are installed in stores such as supermarkets and convenience stores, and several cooling units are provided in each of these showcases. The cooler provided in each showcase stopped the operation of the cooling device at a predetermined time, and the defrosting operation was performed four times a day to six times a day depending on the displayed product. Thereby, reduction of the cooling load was aimed at with respect to the cooling device.
JP 2004-258725 A

  However, many showcase coolers installed at supermarkets and convenience stores were defrosting at a fixed time, but the amount of frost formation depends on the surrounding environment during dry periods such as winter. There were some coolers. Even in such a situation, conventionally, a plurality of coolers have been defrosted at a predetermined time. For this reason, there existed a problem that the useless defrost operation was performed even with the cooler with few frost formation and unnecessary defrost operation.

  The present invention has been made to solve the problems of the related art, and is intended to save energy by avoiding useless defrosting operation in an ambient environment where the amount of frost formation on the cooler is reduced. An object of the present invention is to provide a defrosting control device capable of performing the above.

  That is, the defrosting control device of the present invention comprises a control means for controlling the defrosting of the cooler in the cooling device formed by cooling the inside of the warehouse with the cool air heat-exchanged with the cooler. The defrosting operation of the cooler is performed based on the cycle or the predetermined time or the predetermined operation time, and the defrosting operation is not performed in a situation where the absolute humidity is low based on the absolute humidity of the surrounding environment where the cooling device is installed. It is characterized by.

  Further, in the defrosting control device according to the invention of claim 2, in the above, the control means has a reference value of the absolute humidity of the surrounding environment, and is not executed based on the difference between the reference value and the current absolute humidity The number of operations is determined.

  Further, in the defrosting control device of the invention of claim 3, in claim 1, the control means has a reference value of the absolute humidity of the surrounding environment, and the average value or maximum value of the absolute humidity from the previous defrosting operation is If it is less than the reference value, the next defrosting operation is not executed.

  In the present invention, in the cooling device that cools the inside of the refrigerator with the cool air that exchanges heat with the cooler, the cooler includes a control unit that controls the defrosting of the cooler, and the control unit has a predetermined cycle or a predetermined time or a predetermined operation. The defrosting operation of the cooler is performed based on the time, and the defrosting operation is not performed in the situation where the absolute humidity is low based on the absolute humidity of the surrounding environment where the cooling device is installed. In the surrounding environment where the amount of frost formation is reduced, it is possible to avoid unnecessary defrosting operation, save energy, and improve the cooling capacity.

  In the invention of claim 2, in addition to the above, the control means has a reference value of the absolute humidity of the surrounding environment, and determines the number of defrosting operations not to be executed based on the difference between this reference value and the current absolute humidity. Since the current absolute humidity is significantly lower than the reference value, it is possible to further improve the energy saving and cooling capacity improvement effect by increasing the number of defrosting operations that are not performed. .

  In the invention of claim 3, in addition to the invention of claim 1, the control means has a reference value of the absolute humidity of the surrounding environment, and the average value or maximum value of the absolute humidity from the previous defrosting operation is below the reference value. In this case, since the next defrosting operation is not executed, it is possible to accurately determine the surrounding environment from the previous defrosting operation and determine whether or not the next defrosting operation is necessary. Both energy saving and cooling capacity improvement and reliable defrost control can be achieved.

  The main feature of the present invention is to save energy by avoiding useless defrosting operation in an ambient environment where the amount of frost formation on the cooler is reduced. The purpose of avoiding useless defrosting operation in the surrounding environment where the amount of frost on the cooler is reduced is to prevent the defrosting operation from being performed in a situation where the absolute humidity is low based on the absolute humidity of the surrounding environment. It was realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a defrosting control device 1 showing an embodiment of the present invention, and FIG. 2 is a configuration diagram of the defrosting control device 1 of the present invention and an internal configuration diagram of a dehumidifying device installed in a store 2. Yes.

  The defrost control apparatus 1 in this embodiment performs defrost control of the cooler 5 provided in the open type or closed type showcase 3 installed in many places in stores 2, such as a supermarket and a convenience store. . In a store 2 such as a supermarket or a convenience store, as shown in FIG. 1, the cooler 5 of each showcase 3 installed in the store 2 includes a cooling device 8 installed in a machine room (not shown) of the store 2 or outdoors. The cooling device 8 is supplied with refrigerant from the cooling device 8 and exhibits cooling capacity. In FIG. 1, four showcases 3 are shown, but two or three showcases 3 or four or more showcases 3 may be used.

  The defrosting control device 1 includes a centralized management controller 20 serving as a master device for control, and a plurality of terminal controllers serving as control slave devices connected to the centralized management controller 20 by signal lines 21 and 22. 24. The centralized management controller 20 and the defrost control device 1 are configured by, for example, a general-purpose microcomputer and include a storage unit (memory) that can store various data and a timer. Reference numeral 25 denotes a terminal controller connected to the centralized management controller 20.

  An ID is assigned to each of the centralized management controller 20 and each showcase 3 (terminal controller 24), and the centralized management controller 20 uses this ID to store data (a reference value, which will be described later, and the inside of the showcase 3). 4 temperature setting values, defrost control data, etc.). The central control controller 20 collects the temperature, humidity, operation status data, defrosting status, alarm data, etc. in the cabinet 4 of the showcase 3 from each terminal controller 24 and is connected to each terminal controller 24. Centralized management and control of connected devices.

  On the other hand, the dehumidifying device as shown in FIG. The supply air duct 10 provided in the dehumidifying device is connected to the inside air discharge unit 14 provided in the dehumidifying device and the store 2 by piping. Although not shown, the supply air duct 10 branches in the middle and communicates with the store 2 at an outlet provided in the vicinity of the showcase 3 and at a ceiling outlet provided on the ceiling of the store 2. A pipe is connected in communication with the store 2.

  The return air duct 11 is connected to the inside air suction portion 13 (illustrated in FIG. 2) provided in the dehumidifying device and the ceiling portion of the store 2 by piping, and is formed in the ceiling portion. A plurality of ceiling inlets (not shown) are opened in the store 2.

  Here, the dehumidifying device will be described in detail. The dehumidifier is referred to as a desiccant air conditioner, and includes a rotary dehumidifier 32 having a moisture adsorbing element 31, a blower fan 33 for sucking inside air, a regeneration fan 34 for sucking outside air, and a regeneration heater (electrical Heater) 36 and the like. The blower fan 33 is operated and sucks the air in the return air duct 11 from the inside air suction portion 13 and passes through a moisture adsorption region (described later) of the moisture adsorption element 31, and then the supply air duct 10 from the inside air discharge portion 14. To discharge.

  Reference numeral 37 denotes an outside air intake device that communicates with the suction side of the blower fan 33. The outside air intake device 37 is always closed, but is configured to be able to take in outside air by the blower fan 33 when opened. Reference numerals 38 and 39 denote an indoor temperature sensor and an indoor humidity sensor provided in the inside air suction portion 13, which respectively detect the temperature and humidity of the air in the store 2 sucked from the return air duct 11. The outside air intake device 37 performs ventilation by opening and ventilating at a time when the number of customers increases, and closing when the outside air temperature is high or conversely low. In addition, the moisture adsorption element 31 rises in temperature due to the heating by the heated outside air and the heat of condensation of the water, whereby the temperature of the air passing through the moisture adsorption region is raised to about + 40 ° C.

  The regeneration fan 34 is operated and sucks outside air from the regeneration air intake unit 41 and sequentially passes through the regeneration heater 36 and a moisture release region (to be described later) of the moisture adsorbing element 31. Discharge. Reference numerals 43 and 44 denote an outside air temperature sensor and an outside air humidity sensor, which detect the temperature and humidity of the outside air, respectively.

  46 is a dehumidifying device control device provided in the centralized controller 20, and this control device 46 outputs the indoor temperature sensor 38, the indoor humidity sensor 39, the outdoor air temperature sensor 43, the outdoor air humidity sensor 44, and the like. Based on this, the blower fan 33, the regenerative fan 34, the regenerative heater 36, an electric motor described later, and the like are controlled.

  The central control controller 20 includes a power switch (not shown), an operation switch 26 for performing input operations such as temperature and humidity, an indoor temperature sensor 38 for detecting the temperature in the store 2, and a room for detecting the humidity in the store 2. A humidity sensor 39 and the like are connected. Then, the centralized management controller 20 controls the dehumidifier so that the predetermined set humidity is obtained based on the temperature and humidity in the store 2 detected by the indoor temperature sensor 38 and the indoor humidity sensor 39. In the store 2, air conditioning is performed by an air conditioning device (not shown) connected to the centralized controller 20.

  The moisture adsorbing element 31 has a disk shape with a predetermined thickness and an air passage around it, and is driven to rotate, for example, about half a minute by an electric motor (not shown). The moisture adsorption element 31 is configured to adsorb moisture contained in the air when air passes through it. The air heated by the regenerative heater 36 has a delivery function for absorbing the moisture adsorbed on the moisture adsorption element 31 into the heated air by passing through the moisture adsorption element 31.

  Although the moisture adsorption element 31 rotated by the electric motor is not shown, an air passage provided in the periphery is partitioned by a region partition plate to constitute a first air passage and a second air passage. The portion of the moisture adsorption element 31 located in the first air passage is defined as the moisture adsorption region, and the portion of the moisture adsorption element 31 located in the second air passage is defined as the moisture release region.

  When attention is paid to a part of the moisture adsorption element 31, a cycle in which the part moves from the moisture adsorption region to the moisture release region and returns to the moisture adsorption region by being rotated by the electric motor is repeated. The outside air (regeneration air) sucked from the regeneration air intake 41 by the regeneration fan 34 is heated by the regeneration heater 36 and then passes through the moisture release region of the moisture adsorption element 31 from the second air passage. The regenerative air exhaust unit 42 is configured to be discharged to the outside.

  When the dehumidifying device configured as described above is operated, the blower fan 33, the regeneration fan 34, and the moisture adsorption element 31 are driven, and the regeneration heater 36 is further heated. By the operation of the blower fan 33, the air in the ceiling portion of the store 2 returns from the suction port (not shown) provided in the ceiling portion, enters the air duct 11, and is sucked into the dehumidifier from the inside air suction portion 13. The sucked air is discharged from the inside air discharge unit 14 into the supply air duct 10 through the blower fan 33, the first air passage, and the moisture adsorption region of the moisture adsorption element 31.

  At this time, the moisture contained in the air is adsorbed by the moisture adsorption element 31 in the portion serving as the moisture adsorption region, and is transported to the moisture release region by rotation by the electric motor. Further, the dehumidified dry air discharged into the supply air duct 10 is blown out from the outlet through the branched supply air duct 10 to the floor of the store 2 near the showcase 3 (return). Moreover, after a part of air heat-exchanges with the indoor heat exchanger which is not shown in figure, it blows off from the blower outlet to the ceiling part of the shop 2 (return), and air conditioning is performed.

  The dehumidifying device sucks outside air (regenerated air) from the regenerated air intake unit 41 by the operation of the regenerating fan 34. The sucked air is heated to about + 140 ° C. by the regenerative heater 36, further passes through the moisture release area of the moisture adsorption element 31, and is discharged to the outside through the regeneration fan 34 through the regeneration air exhaust unit 42. At this time, the outside air is discharged to the outside after receiving the moisture adsorbed by the moisture adsorption element 31 in the moisture adsorption area in the moisture release area of the moisture adsorption element 31. Such moisture adsorption and release action is continuously achieved by the rotation of the moisture adsorption element 31.

  That is, the moisture adsorbed by the moisture adsorption element 31 in the moisture adsorption region is transported to the moisture release region by the rotation of the moisture adsorption element 31, where it is absorbed by the outside air heated by the regenerative heater 36, and finally to the outside. Discharged. As a result, the air blown into the store 2 through the supply air duct 10 is dehumidified as described above, so that the inside of the store 2 is dehumidified, and the humidity is reduced or the increase in humidity is suppressed.

  The dehumidifying device controls the fans 33 and 34, the regenerative heater 36, and the electric motor of the moisture adsorption element 31 based on the outputs of the sensors 38, 39, 43, and 44, and maintains the inside of the store 2 at the set humidity. That is, the defrosting control device 1 energizes the regenerative heater 36 when the humidity in the store 2 is higher than the setting based on the outputs of the sensors 38 and 39, and stops energization when the humidity is lower than the set value. To the set humidity.

  The indoor humidity sensor 39 provided in such a dehumidifying device can only measure relative humidity. Therefore, in the present invention, the absolute humidity in the store 2 using an approximate curve (FIG. 3) from the temperature in the store 2 detected by the indoor temperature sensor 38 and the relative humidity in the store 2 detected by the indoor humidity sensor 39. And the defrosting operation of the cooler 5 is performed based on this absolute humidity. FIG. 3 shows the relationship between temperature and absolute humidity when the relative humidity is 100%. The sensors 38 and 39 are shared by the dehumidifying device and the dehumidifying air conditioner 1.

That is, the computation expression for calculating the absolute humidity from temperature and relative humidity, the approximate curve ^{_{H A = H R /100{0.0004365xT 3 +}} 0.001967xT 2 + 0.33373xT + 3.6983} ( absolute humidity H _A [g / kg ], Temperature T [° C.] and relative humidity H _R [%] This calculation formula is stored and executed in the memory of the centralized controller 20 (microcomputer). The table showing the relationship with humidity is a well-known table and will not be described in detail, and the table data showing the relationship between temperature, relative humidity, absolute humidity, and absolute humidity is stored in the centralized controller. 20 based on the temperature of the store 2 detected by the indoor temperature sensor 38 and the relative humidity in the store 2 detected by the indoor humidity sensor 39. It may be possible to obtain the absolute humidity from the table data stored in the memory.

  And the defrost control apparatus 1 performs the defrost operation of the cooler 5 of the showcase 3 from the absolute humidity which the centralized control controller 20 computed based on the said calculation formula. The defrosting operation is performed based on a predetermined cycle or a predetermined time or a predetermined operation time. Specifically, when an absolute humidity corresponding to a temperature of + 28 ° C. and a relative humidity of 40% is set as a reference value, for example, an absolute humidity corresponding to a temperature of + 28 ° C. and a relative humidity of 45% is set as a reference upper limit value, The absolute humidity corresponding to + 28 ° C. and 35% relative humidity is determined as the reference lower limit value. That is, the reference upper limit value and the reference lower limit value are set to + 28 ° C. · 40% ± 5% with respect to the reference value + 28 ° C. · 40%.

  When the reference value (absolute humidity corresponding to + 28 ° C./45%) is input by the operation switch 26, the reference value, the reference upper limit value, and the reference lower limit value are stored in the memory of the centralized management controller 20. Since the conventional defrosting of the cooler 5 is executed by stopping the cooling operation of the cooler 5, the temperature in the interior 4 of the showcase 3 rises and adversely affects the displayed goods. Moreover, since the amount of frost formation of the cooler 5 will increase and cooling capacity will fall if defrost is not performed, it was necessary to defrost the cooler 5 regularly.

  Therefore, the centralized management controller 20 performs defrosting of the cooler 5 of the showcase 3 six times a day, for example, at midnight, 4 o'clock, 8 o'clock, 12 o'clock, 16 o'clock, 20 o'clock, and again at midnight. Is programmed to do so. That is, a defrosting schedule program for six times a day is stored in the memory of the centralized controller 20 (microcomputer) for the cooler 5 of each showcase 3. Since this defrosting schedule is set with a relatively small number of customers in the store 2, the defrosting time is not limited to midnight, 4 o'clock, 8 o'clock, 12 o'clock, 16 o'clock, 20 o'clock. It can be at other times.

  Further, the central control controller 20 compares the received average value of absolute humidity from midnight to immediately before 12:00, or the highest value among them and the reference value (reference lower limit value), and the absolute humidity is When it is lower than the reference value (reference lower limit value), it is programmed so that the defrosting is executed at 16:00 without executing the next (12 o'clock) defrosting.

  Then, the centralized management controller 20 transmits a signal to the terminal controller 24 and executes the defrosting operation of the cooler 5 based on a predetermined cycle or a predetermined time or a predetermined operation time. Specifically, the terminal controller 24 performs the defrosting operation of the cooler 5 of the showcase 3 at a predetermined cycle, a predetermined time, or a predetermined operation time from the absolute humidity calculated by the central management controller 20 based on the calculation formula. .

  Next, operation | movement of the defrost control apparatus 1 is demonstrated in detail with reference to the flowchart of FIG. It is assumed that the defrosting schedule and setting information for each showcase 3 are stored in the memory of the central control controller 20 (microcomputer), and that the showcase 3 has already been cooled. Further, the defrosting of the showcase 3 performed 6 times a day is executed by transmitting a defrosting instruction from the centralized management controller 20 to the defrosting control device 1. When the defrosting schedule is changed in step S1, the process proceeds to step S2, and the defrosting control device 1 receives setting information such as the defrosting schedule and the cooling temperature of the showcase 3 from the centralized controller 20, and proceeds to step S3.

  Therefore, the central control controller 20 has a showcase 3 in which defrosting is performed three or more times a day from the defrost control device 1, and if there is a showcase 3 in which a defrosting schedule exists from 12:00 to 18:00, Proceeding to S4, the showcase 3 is set from the ID. In step S5, when the defrosting target showcase 3 is present, the centralized management controller 20 proceeds to step S6, and proceeds to step S7 if the defrosting control determination time has been reached.

  Therefore, the central control controller 20 shows the showcase 3 when the absolute humidity in the store 2 from midnight to 11:59 or lower than the previous defrosting is lower than the reference value (temperature + 28 ° C., relative humidity 45%). Is determined to be an environment in which the amount of frost on the cooler 5 is small, and the process proceeds to step S8. The centralized management controller 20 selects a defrosting deletion target from each showcase 3, transmits the defrosting deletion target data to the defrosting control device 1 having the selected ID, and the first time after midnight to 11:59 Defrosting (12:00 defrosting) is deleted. In addition, the defrosting after 12:00 is performed.

  In step S9, when the defrosting of the day has been completed and the time of the next day (midnight) has been reached, in detail, when the defrosting time has elapsed, the process proceeds to step S10. The centralized management controller 20 initializes the humidity condition, determination result, deletion target defrosting, and the like stored in the ID memory of the showcase 3 that has received the defrosting deletion target data, and ends.

  On the other hand, in step S9, the defrosting of the day is finished, and if the time of the next day (midnight) has not been reached, the process is finished. In step S7, the centralized controller 20 determines that the absolute humidity when the temperature in the store 2 from midnight to 11:59 is + 28 ° C. and the relative humidity is 45% from the previous defrost is a reference value ( If it is lower than the reference lower limit value (below the absolute humidity), it is determined that the ambient environment of the showcase 3 is an environment in which the amount of frost on the cooler 5 is large, the process proceeds to step S9 and the subsequent steps are executed.

  In step S6, the centralized management controller 20 has the defrosting target showcase 3 and if they have not reached the defrosting control determination time, the process proceeds to step S11, and if the time is from 12:00 to 18:00, step S12. Proceed to When there is the deletion target defrosting showcase 3, the centralized management controller 20 proceeds to step S <b> 13, and when the showcase 3 has reached the deletion target defrosting time, the central management controller 20 proceeds to step S <b> 14. Therefore, the centralized management controller 20 sets the defrost target to be deleted, proceeds to step S9, and executes the subsequent steps.

  If the time is other than 12:00 to 18:00 in step S11, the centralized management controller 20 proceeds to step S9 and executes the subsequent steps. In step S12, the centralized management controller 20 determines that there is no deletion target defrosting step S9. Go to and execute the following. Further, in step S13, the centralized management controller 20 proceeds to step S9 when the deletion target defrosting time has not been reached, and executes the subsequent steps.

  Moreover, when there is no change in the defrosting schedule of the showcase 3 in the step S1, and there is a defrosting schedule three or more times a day from the defrost control device 1 in the step S3, the defrosting time is from 12:00 to 18:00. If there is no showcase 3 having a schedule, the process proceeds to step S5, and the subsequent steps are executed.

  That is, in steps S1 to S4, the setting and type of the defrosting schedule and the showcase 3 are read to determine whether there is a defrosting deletion target. In steps S5 to S8 and steps S11 to S14, after determining whether there is a target showcase 3 that satisfies the defrosting deletion condition at the determination time (12:00), the target showcase 3 is 11:59 or later. The first defrosting (12:00) is deleted. Moreover, in step S9-S10, the determination result of the previous day is initialized at the time of a date change, and the defrosting schedule of the next day is reset.

  In this way, the centralized management controller 20 performs the defrosting operation of the cooler 5 based on a predetermined cycle, a predetermined time, or a predetermined operation time, and based on the absolute humidity of the surrounding environment where the cooling device 8 is installed. , The defrosting operation is stopped in a situation where the absolute humidity is low (when the temperature in the store 2 is + 28 ° C. and the relative humidity is 45% and the absolute humidity is lower than the reference value (reference lower limit value)). is doing. Thereby, useless defrosting operation of the cooler 5 can be avoided in an ambient environment in which the amount of frost on the cooler 5 is reduced.

  Next, another operation of the defrost control device 1 of the present invention will be described. In addition, the defrost control apparatus 1 of the other Example of this invention has the same structure as the above-mentioned Example, and only defrost control of the centralized management controller 20 differs. Hereinafter, different parts will be described. The central control controller 20 has a reference value (including a reference upper limit value and a reference lower limit value) of absolute humidity in the surrounding environment, and based on the difference between this reference value (reference lower limit value) and the current absolute humidity. And a program for determining the number of defrosting operations.

  That is, the centralized controller 20 determines the number of defrosting operations based on the difference between the reference value (reference lower limit value) of the absolute humidity of the surrounding environment and the current absolute humidity. When the humidity is significantly lower than the reference value (reference lower limit value), the defrosting operation of the cooler 5 at a predetermined time determined by the defrosting schedule can be stopped. In addition, the time which reduces the frequency | count of the defrost operation of the cooler 5 is made into the same time as Example 1. FIG. Thereby, the frequency | count of a defrost operation of the cooler 5 decided by the defrost schedule can be reduced, and it becomes possible to aim at energy saving and the improvement of cooling capacity.

  Next, another operation of the defrost control device 1 of the present invention will be described. In addition, the defrost control apparatus 1 of the other Example of this invention has a structure substantially the same as the above-mentioned Example, and only defrost control of the centralized management controller 20 differs. Hereinafter, different parts will be described. The central control controller 20 has a reference value (including a reference upper limit value and a reference lower limit value) of the absolute humidity of the surrounding environment, and the average value or the highest value of the absolute humidity from the previous defrosting operation of the cooler 5. Is below the reference value (reference lower limit value), there is a program that does not execute the next defrosting operation, and this program is stored in the memory of the microcomputer of the centralized management controller 20 and executed. Thereby, the condition of the surrounding environment of the cooler 5 can be judged accurately from the last defrost operation, and the necessity of the next defrost operation can be determined. Therefore, it is possible to achieve both energy saving and improvement in cooling capacity and reliable defrost control in the defrost control device 1.

  In the embodiments, the desiccant air conditioner is described as a desiccant air conditioner. However, the dehumidifier is not limited to the desiccant air conditioner, and a refrigerant using chlorofluorocarbon or non-fluorocarbon gas (carbon dioxide gas, nitrogen gas, etc.) as a refrigerant. The present invention is also effective for a cycle air conditioner.

  Further, the present invention is not limited to the above embodiments, and the present invention is effective even when various other changes are made without departing from the spirit of the present invention.

It is a block diagram of the defrost control apparatus which shows one Example of this invention (Example 1). It is an internal block diagram of the dehumidification apparatus installed in a shop while comprising the defrost control apparatus of this invention. It is a figure which shows the approximate curve of absolute humidity in case relative humidity is 100% from temperature and relative humidity. It is a flowchart which shows operation | movement of the defrost control apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Defrost control apparatus 2 Store 3 Showcase 4 Inside 5 Cooler 20 Central control controller 26 Operation switch 38 Indoor temperature sensor 39 Indoor humidity sensor

Claims (3)

In the cooling device that cools the interior with cold air exchanged with a cooler,
Comprising control means for controlling defrosting of the cooler;
The control means performs the defrosting operation of the cooler based on a predetermined cycle or a predetermined time or a predetermined operation time, and the absolute humidity is low based on the absolute humidity of the surrounding environment where the cooling device is installed. A defrost control device for a cooling device, wherein the defrost operation is not executed in a situation.   The said control means has the reference value of the absolute humidity of the said surrounding environment, and determines the frequency | count of the defrost operation which is not performed based on the difference of this reference value and the present absolute humidity. The defrost control apparatus of the cooling device as described in 2.   The control means has a reference value of the absolute humidity of the surrounding environment, and when the average value or maximum value of the absolute humidity from the previous defrost operation is not more than the reference value, the next defrost operation is not executed. The defrost control device for a cooling device according to claim 1.

Images