JP7293633B2 - Showcase - Google Patents

Description

TECHNICAL FIELD The present invention relates to a showcase and a defrosting control method for the showcase that can suppress an increase in product temperature at the end of defrosting.

In stores such as convenience stores and supermarkets, frozen or refrigerated showcases are arranged. Such showcases are provided with cooling devices for freezing or refrigerating products (see Patent Document 1). In addition, the cooling device performs a defrosting process to remove frost adhered to the cooling heat exchanger, which is an evaporator, to suppress reduction in the cooling effect.

JP 2006-38252 A

By the way, in the defrosting process, the cooling temperature control output is stopped, the defrosting heater in the vicinity of the cooling heat exchanger is turned on, or the high-temperature refrigerant is sent to the cooling heat exchanger to prevent the adhesion of the refrigerant to the cooling heat exchanger. Removes frost. This defrosting process includes a draining process for removing water adhered by defrosting by driving a blower fan, and the defrosting process ends when this draining process ends.

However, if the defrosting process is followed by the cooling temperature control process that drives the blower fan, the temperature of the cooling heat exchanger is high, close to the defrosting release temperature, so warm air is exposed to the product. As a result, the product temperature of the product to be cooled rises.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a showcase and a defrosting control method for the showcase that can suppress an increase in product temperature at the end of defrosting.

In order to solve the above-described problems and achieve the object, the showcase according to the present invention performs cooling processing by a refrigeration cycle including a cooling heat exchanger for freezing or refrigerating the products displayed in the showcase, and A showcase having a cooling device that performs defrosting processing including draining processing of a cooling heat exchanger, comprising a defrosting release temperature sensor that detects a defrosting release temperature, and blowing air to the cooling heat exchanger. When the defrosting temperature is reached after the defrosting process is started, the blowing fan is driven to perform the draining process for a predetermined draining time to end the defrosting process. and a defrosting control unit for restarting the cooling process after the frosting process and for driving the blower fan after stopping the blower fan for a predetermined stop time.

Further, in the showcase according to the present invention, in the above invention, the predetermined stop time is the time after the defrosting process ends until the defrosting release temperature sensor detects the set cooling temperature control target temperature. It is characterized by

Further, in the showcase according to the present invention, in the above invention, when the defrosting processing time including the predetermined water draining time of this time is shorter than the defrosting processing time of the previous time, the time difference The predetermined stop time is shortened accordingly, and when it is longer than the previous defrosting processing time, the predetermined stop time is lengthened according to the time difference.

Further, in the showcase according to the present invention, in the above invention, the defrosting control unit controls that the temperature detected by the defrosting release temperature sensor is higher than the set cooling temperature control target temperature at the start of the defrosting process. In this case, the predetermined stop time is shortened according to the temperature difference, and when the temperature is lower than the set cooling temperature control target temperature, the predetermined stop time is lengthened according to the temperature difference.

In addition, the showcase defrosting control method according to the present invention performs cooling processing by a refrigeration cycle including a cooling heat exchanger for freezing or refrigerating the products displayed in the showcase, and drains the cooling heat exchanger. A defrosting control method for a showcase that performs defrosting processing including processing, when a defrosting release temperature is reached after the defrosting processing is started, a blower fan of the cooling heat exchanger is driven and a predetermined temperature is reached. During the draining time, the draining process is performed to end the defrosting process, and after the defrosting process, the cooling process is resumed, and the blowing fan is stopped for a predetermined stop time, and then the blowing fan is driven. do.

ADVANTAGE OF THE INVENTION According to this invention, the temperature rise of goods at the time of completion|finish of defrosting can be suppressed.

FIG. 1 is a diagram showing a schematic configuration of a showcase cooling device according to an embodiment of the present invention. FIG. 2 is a time chart showing an example of defrosting processing by a defrosting control unit. FIG. 3 is a flowchart showing a defrosting control processing procedure by a defrosting control unit. FIG. 4 is a flowchart showing a defrosting control process procedure by the defrosting control unit of Modification 1. FIG. FIG. 5 is a flow chart showing a defrosting control process procedure by the defrosting control section of Modification 2. As shown in FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

<Overall composition>
FIG. 1 is a diagram showing a schematic configuration of a showcase cooling device 1 according to an embodiment of the present invention. As shown in FIG. 1, the showcase cooling device 1 has a refrigeration cycle mechanism in which a compressor 10, a four-way valve 12, a condenser 13, an expansion valve 14, and an evaporator 15 as a cooling heat exchanger are connected in sequence. have. The condenser 13 has a blower fan 23 that blows the heat-exchanged air to the outside of the apparatus. The evaporator 15 also has a blower fan 25 that is arranged near the product placement area 2 and blows heat-exchanged air to the product placement area 2 . The cooling air blown from the evaporator 15 forms an air curtain to cool the product placement area 2 .

When cooling the product (solid line arrow), the compressor 10 compresses the low-pressure refrigerant introduced from the evaporator 15 through the four-way valve 12 into a high-pressure refrigerant and discharges it to the condenser 13 through the four-way valve 12. . The condenser 13 condenses the high-pressure refrigerant to radiate heat, and leads the condensed refrigerant to the expansion valve 14 . The expansion valve 14 decompresses and expands the introduced refrigerant and discharges it to the evaporator 15 . The evaporator 15 absorbs heat with the decompressed and expanded refrigerant, blows the cooled air toward the product placement area 2 , and discharges the normal pressure refrigerant to the compressor 10 via the four-way valve 12 .

On the other hand, when defrosting (dashed arrow) is performed, the four-way valve 12 is switched (turned on) to cause the refrigerant to flow backward, and the high-temperature and high-pressure refrigerant (hot gas) generated by the compressor 10 is led out to the evaporator 15. , raises the temperature of the evaporator 15 and removes the frost adhering to the evaporator 15 .

In addition to the hot gas method using the four-way valve 12 described above, the defrosting method is not provided with the four-way valve 12, and part of the high-temperature and high-pressure refrigerant generated by the compressor 10 is directly introduced into the evaporator 15. There is a hot gas bypass system that Further, the defrosting method is a defrosting heater method in which a defrosting heater is provided near the evaporator 15, the cooling process is stopped during defrosting, and the temperature of the evaporator 15 is raised by turning on the defrosting heater. There is also In this embodiment, a cooling device employing a hot gas method as an example of a defrosting method will be described.

Further, downstream of the evaporator 15, an air outlet temperature sensor S1 for detecting the air outlet temperature is provided. The blowout temperature sensor S1 also functions as a defrost release temperature sensor that detects the defrost release temperature. Further, in the product placing area 2, an internal temperature sensor S2 for detecting the product temperature is provided. In addition, you may provide a defrost release temperature sensor separately from blowing temperature sensor S1. For example, as shown in FIG. 1, a defrosting release temperature sensor S10 that detects the refrigerant outlet temperature of the evaporator 15 during defrosting may be provided. Also, a defrost release temperature sensor S10 directly arranged on the evaporator 15 may be provided. Further, the defrost release temperature sensor is not limited to the temperature as long as it can detect the defrost state of the evaporator 15. For example, the defrost state may be detected by an image.

The showcase cooling device 1 also includes a control unit 30 , an input/output unit 40 and a storage unit 50 . The control unit 30 is a control unit that controls the entire device, and has a defrosting control unit 31 . The defrosting control unit 31 performs cooling control processing including defrosting control processing based on the values of various sensors including the blowout temperature sensor S1 and the inside temperature sensor S2. The defrosting control unit 31 controls the rotation speed of the compressor 10 and the like via the drive unit 11, controls the opening degree of the expansion valve 14, controls the refrigerant flow rate, and sets the blowout temperature or the inside temperature. Control the temperature.

The input/output unit 40 is an input/output device that inputs various setting values and performs output such as displaying various states.

The storage unit 50 stores set values such as the defrost time W, the set cooling temperature control target temperature TO, the set defrost release temperature TR, and the predetermined drain time Tw.

<Example of defrosting process>
Next, an example of the defrosting process by the defrosting control section 31 will be described with reference to the time chart shown in FIG. First, when the time counted from the end of the previous defrosting reaches the defrosting time W at time t1, the defrosting control unit 31 turns off the cooling temperature control command (Fig. 2(a)), and issues the defrosting command. (FIG. 2(b)), the four-way valve 12 is turned ON (FIG. 2(c)), and the blower fan 25 is turned OFF (FIG. 2(d)). It should be noted that the blower fan 25 blows air toward the product placement area 2 until time t1. Thereby, the evaporator 15 is heated and the defrosting process is started.

After that, at time t2, when the outlet temperature sensor S1 functioning as a defrost release temperature sensor detects the set defrost release temperature TR (FIG. 2(e)), the blower fan 25 is turned ON and driven (FIG. 2 ( c)), draining is performed for a predetermined draining time Tw until time t3. The blower fan 25 is reversely driven during the predetermined draining time Tw.

After that, when the draining process ends at time t3, the defrosting control unit 31 turns ON the cooling temperature control command (FIG. 2(a)), turns OFF the defrosting command (FIG. 2(b)), and blows air. The fan 25 is turned off for a predetermined stop time Tz (FIG. 2(d)). As a result, the warm air blown from the heated evaporator 15 is not exposed to the product, so the temperature of the product does not rise.

The predetermined stop time Tz may be a time set in advance, or, as shown in FIG. 2, may be a time up to time t4 when the blowout temperature sensor S1 drops to the set cooling temperature control target temperature TO. . When the time t4 is reached, the defrosting control unit 31 drives the blower fan 25 in forward rotation (Fig. 2(d)), and continues the cooling temperature control process.

<Defrost control processing>
Next, the defrosting control processing procedure by the defrosting control unit 31 will be described with reference to the flowchart shown in FIG. As shown in FIG. 3, the defrosting control unit 31 performs cooling temperature control processing (step S101). After that, the defrosting control unit 31 determines whether or not the defrosting start point (defrosting time W) has been reached (step S202). If the defrosting start point has not been reached (step S102, No), this determination process is repeated.

On the other hand, when the defrosting start point has been reached (step S102, Yes), the four-way valve 12 is turned ON to start the defrosting process (step S103). After that, the defrost controller 31 determines whether or not the temperature detected by the blow-out temperature sensor S1 has reached the set defrost release temperature TR (step S104). If the detected temperature has not reached the set defrost release temperature TR (step S104, No), this determination process is repeated.

On the other hand, when the detected temperature reaches the set defrost release temperature TR (step S104, Yes), the four-way valve 12 is turned OFF, and the blower fan 25 is driven in reverse to start draining (step S105). . After that, the defrosting control unit 31 determines whether or not the predetermined draining time Tw has passed (step S106). If the predetermined draining time Tw has not elapsed (step S106, No), this determination process is repeated.

On the other hand, when the predetermined draining time Tw has passed (step S106, Yes), the cooling temperature control process is started (step S107), and the blower fan 25 is stopped (step S108).

After that, the defrost control unit 31 determines whether or not the detected temperature has decreased to the set cooling target temperature TO (step S109). If the detected temperature has not decreased to the set cooling target temperature TO (step S109, No), this determination process is repeated to keep the blower fan 25 stopped. On the other hand, if the detected temperature has decreased to the set cooling target temperature TO (step S109, Yes), the blower fan 25 is driven again (step S110), the cooling temperature control process is continued, and this process ends. Note that the above-described processing is repeatedly performed at predetermined time intervals.

<Modification 1>
In the defrosting control process shown in FIG. 3, the blower fan 25 is stopped until the detected temperature drops to the set cooling target temperature TO. If the defrosting processing time including the predetermined draining time Tw is shorter than the previous defrosting processing time, the predetermined stop time Tz is shortened according to the time difference, and if it is longer than the previous defrosting processing time, The predetermined stop time Tz is reset to be longer according to the time difference.

FIG. 4 is a flowchart showing a defrosting control process procedure by the defrosting control section 31 of Modification 1. As shown in FIG. The processing from steps S201 to S208 of Modification 1 is the same as the processing from steps S101 to S108 shown in FIG.

As shown in FIG. 4, after stopping the blower fan (step S208), the defrosting control unit 31 determines whether the current defrosting time Td is shorter than the previous defrosting time (step S209). If the current defrosting time Td is shorter than the previous defrosting time Td (step S209, Yes), the current predetermined stop time Tz is reset to be shorter than the previous predetermined stop time Tz according to the time difference ( step S210). On the other hand, if the current defrosting time Td is shorter than the previous defrosting time Td (step S209, No), the current predetermined stop time Tz is reset longer than the previous predetermined stop time Tz according to the time difference. (step S211).

After that, it is determined whether or not the reset predetermined stop time Tz has elapsed (step S212). If the reset predetermined stop time Tz has not elapsed (step S212, No), this determination process is repeated, and if the reset predetermined stop time Tz has elapsed (step S212, Yes), The blower fan 25 is re-driven in forward rotation (step S213), and the process ends.

<Modification 2>
In the defrosting control process shown in FIG. 3, the blower fan 25 is stopped until the detected temperature drops to the set cooling target temperature TO. When the temperature detected by the defrosting release temperature sensor at the start of the defrosting process is higher than the set cooling temperature control target temperature TO, the predetermined stop time Tz is shortened according to the temperature difference, and the set cooling temperature control target temperature TO is shortened. If it is lower than , resetting is performed to lengthen the predetermined stop time Tz according to the temperature difference.

FIG. 5 is a flowchart showing a defrosting control process procedure by the defrosting control section 31 of Modification 2. As shown in FIG. It should be noted that the processing from steps S301 to S308 in this modified example 2 is the same as the processing from steps S101 to S108 shown in FIG.

As shown in FIG. 5, after stopping the blower fan (step S308), the defrosting control unit 31 determines whether or not the temperature at the start of defrosting is higher than the set cooling temperature control temperature TO (step S309). If the temperature at the start of defrosting is higher than the set cooling temperature control temperature TO (step S309, Yes), the current predetermined stop time Tz is reset to be shorter according to the temperature difference (step S310). On the other hand, if the temperature at the start of defrosting is lower than the set cooling temperature control temperature TO (step S309, No), the current predetermined stop time Tz is reset longer according to the temperature difference (step S311).

Thereafter, it is determined whether or not the reset predetermined stop time Tz has elapsed (step S312). If the reset predetermined stop time Tz has not elapsed (step S312, No), this determination process is repeated, and if the reset predetermined stop time Tz has elapsed (step S312, Yes), The blower fan 25 is driven forward again (step S313), and the process ends.

In the above-described embodiment and modification, the blowing direction of the blower fan 25 is reversed during the defrosting process. When the blowing direction is reversed during the defrosting process, the position of the defrosting release temperature sensor is preferably provided on the outlet of the blower fan 25 or on the refrigerant outlet side.

In addition, each configuration illustrated in the above embodiment and modified examples is functionally schematic, and does not necessarily need to be physically configured as illustrated. In other words, the form of dispersion/integration of each device and component is not limited to the illustrated one, and all or part of them can be functionally or physically distributed/integrated in arbitrary units according to various usage conditions. can be configured

1 Showcase Cooling Device 2 Commodity Placement Area 10 Compressor 11 Drive Unit 12 Four-Way Valve 13 Condenser 14 Expansion Valve 15 Evaporator 23, 25 Blower Fan 30 Control Unit 31 Defrost Control Unit 40 Input/Output Unit 50 Storage Unit S1 Blow-out temperature sensor S2 Inside temperature sensor S10 Defrost release temperature sensor Time from t1 to t4 TO Set cooling temperature adjustment target temperature TR Set defrost release temperature Tw Predetermined drain time Tz Predetermined stop time W Defrost time

Claims (2)

A showcase having a cooling device that performs cooling processing by a refrigerating cycle including a cooling heat exchanger for freezing or refrigerating products displayed in the showcase and performs defrosting processing including draining of the cooling heat exchanger. and
a defrost release temperature sensor that detects a defrost release temperature;
A blower fan for blowing air to the cooling heat exchanger;
After the defrost process is started, when the defrost release temperature is reached, the blower fan is driven to perform the water drain process for a predetermined water drain time to end the defrost process, and after the defrost process, cooling is performed. a defrosting control unit that restarts the process and drives the blower fan after stopping the blower fan for a predetermined stop time;
with
The defrosting control unit shortens the predetermined stop time according to the time difference when the current defrosting processing time including the predetermined water draining time is shorter than the previous defrosting processing time, and the previous defrosting processing. A showcase characterized in that, if it is longer than the time, the predetermined stop time is lengthened according to the time difference. A showcase having a cooling device that performs cooling processing by a refrigerating cycle including a cooling heat exchanger for freezing or refrigerating products displayed in the showcase and performs defrosting processing including draining of the cooling heat exchanger. and
a defrost release temperature sensor that detects a defrost release temperature;
A blower fan for blowing air to the cooling heat exchanger;
After the defrost process is started, when the defrost release temperature is reached, the blower fan is driven to perform the water drain process for a predetermined water drain time to end the defrost process, and after the defrost process, cooling is performed. a defrosting control unit that restarts the process and drives the blower fan after stopping the blower fan for a predetermined stop time;
with
When the temperature detected by the defrosting release temperature sensor at the start of the defrosting process is higher than the set cooling temperature control target temperature, the defrosting control unit shortens the predetermined stop time according to the temperature difference. and, when the temperature is lower than the set cooling temperature control target temperature, the predetermined stop time is lengthened according to the temperature difference.

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