JP2006226587A - Showcase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a showcase that does not require a temperature detecting member exclusively used for a heater, and capable of stopping the dewproofing driving of the heater on the basis of a temperature inside of a merchandise storage. <P>SOLUTION: In this showcase wherein the temperature in the merchandise storage 11 is detected on the basis of a detection signal output from a thermistor 15, and electric power is distributed to a compressor 21 to implement a cooling operation when the temperature is higher than a temperature for driving the compressor 21, a heater control portion 41 of a control portion 40 stops the heater 16a by opening a switch 47a, when the temperature detected in driving the heater 16a is higher than a prescribed temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a showcase for storing a frozen or refrigerated product installed in a store such as a supermarket or a convenience store.

  Conventionally, as this type of showcase, a product storage provided in the showcase body, a refrigerant circuit connecting an evaporator, a condenser, an expansion means and a compressor, and air sucked from the product storage The air flow path that cools the product by an evaporator and discharges it into the product storage, a heater for preventing condensation, and a temperature detection component that detects the temperature in the product storage are output from the temperature detection component. What drives a compressor based on a detection signal is known.

  However, while the showcase is in operation, the heater is driven even when the temperature in the cabinet is high, so there is a problem that the heat load is increased by the heater and electric power is consumed more than necessary.

In view of this, a sensor that detects the outside air temperature and the outside air humidity at the time of starting the showcase is provided in the control circuit, and the heat generation amount of the heater is controlled based on the detected outside air temperature and the outside air humidity (for example, Patent Document 1).
JP 2004-30993 A

  However, if a dedicated temperature detection component is provided in the control circuit, the amount of heat generated by the heater can be controlled. In this case, however, the temperature detection component must be added as a separate component, which increases costs. There is a problem.

  The present invention has been made in view of the above-mentioned problems, and the object of the present invention is to prevent dew condensation according to the temperature in the product storage without requiring a temperature detection component dedicated to the heater. An object of the present invention is to provide a showcase capable of stopping heater driving.

  In order to achieve the above object, a showcase of the present invention comprises a product storage provided in a showcase body, a refrigerant circuit formed by connecting an evaporator, a condenser, an expansion means, and a compressor, and a product storage. A temperature detecting device is provided with a ventilation path for cooling air sucked from inside by an evaporator and discharging it into the product storage, a heater for preventing condensation, and a temperature detecting means for detecting the temperature in the product storage. When the compressor is controlled based on the temperature detected by the means, the heater is stopped when the temperature detected by the temperature detecting means is higher than a predetermined temperature, and when the temperature falls below the predetermined temperature. Is provided with a heater control means for driving the heater. Thereby, the temperature detecting means for controlling the compressor can be applied to the heater control, and the heater is stopped by the heater controlling means when the temperature detected by the temperature detecting means becomes higher than a predetermined temperature. Does not consume power. Further, since the temperature detection means for controlling the compressor is used for heater control, there is no need for temperature detection parts dedicated to the heater.

  According to the present invention, since the heater can be stopped when the temperature in the product storage chamber rises, it is possible to save energy without consuming more power than necessary. Furthermore, since the temperature detection means for controlling the compressor can be used for controlling the heater, a dedicated temperature detection component is not required, and the cost can be reduced.

  1 to 7 show a first embodiment of the present invention. FIG. 1 is a perspective view of a showcase, FIG. 2 is a side sectional view thereof, FIG. 3 is a block diagram of a refrigerant circuit, and FIG. FIG. 5 is a control circuit diagram, and FIGS. 6 and 7 are flowcharts of the control method.

  The showcase includes a showcase body 10 having an open upper surface, a machine room 20 provided at a lower portion of the showcase body 10, a refrigerant circuit 30 constituting a refrigeration cycle, and a thermistor that detects the temperature of the product storage unit 11. 15, a heater 16 a for preventing condensation, and a control unit 40 that controls the heater 16 a and the compressor 21.

  The showcase body 10 is formed of heat insulating walls on the front side, left and right side surfaces, back side, and bottom side, and on the front side, bottom side, and back side between the product storage unit 11 provided in the interior. The ventilation path 12 is formed along. An air discharge port 12a is provided at the upper end on the back side of the ventilation path 12, and an air suction port 12b is provided at the upper end on the front side. On the bottom surface side of the ventilation path 12, an evaporator 13 connected to the refrigerant circuit 30 is disposed in the ventilation path 12. An evaporator blower 14 that exchanges heat between the refrigerant in the evaporator and the air in the ventilation path 12 is disposed on the front side of the evaporator 13.

  A thermistor 15 is provided in the product storage section 11 of the showcase body 10, and an electrical resistance that changes according to the temperature of the product storage section 11 is detected as a detection signal. The thermistor 15 outputs the detected detection signal to the control unit 40 described later. The thermistor 15 constitutes a temperature detecting means in the claims of the present application.

  The heater 16a is provided in the upper part of the air inlet 12b, and by heating the air inlet 12b, the condensation of the air inlet 12b due to adhesion of moisture contained in the cooled air is prevented. .

  A compressor 21 and a condenser 22 connected to the refrigerant circuit 30 are arranged in the machine room 20. The condenser 22 is used for heat exchange between the air in the machine room 20 and the refrigerant in the condenser 22. A condenser blower 23 is provided.

  The refrigerant circuit 30 includes an evaporator 13, a compressor 21, a condenser 22, and an expansion valve 24, which are connected by a refrigerant distribution pipe. That is, as shown in FIG. 3, the discharge side of the compressor 21 is connected to the suction side of the condenser 22, and the discharge side of the condenser 22 is connected to the suction side of the expansion valve 24. Further, the discharge side of the expansion valve 24 is connected to the suction side of the evaporator 13, and the discharge side of the evaporator 13 is connected to the suction side of the compressor 21.

  The control part 40 consists of microcomputers, and adjusts the temperature in the product storage 11 using, for example, an electronic thermostat. As shown in FIG. 4, the control unit 40 includes a heater control unit 41 for controlling the heater 16 a and a compressor control unit 42 for controlling the compressor 21. The heater control unit 41 is preset with a temperature at which the driving of the heater 16 a is stopped, and controls the heater 16 a based on the temperature detected by the thermistor 15. The predetermined temperature in the claims of the present application is a temperature at which the driving of the heater 16a is stopped. Further, the compressor control unit 42 is preset with a temperature at which the compressor 21 is driven and a temperature at which the compressor 21 is stopped, and controls the compressor 21 based on the temperature detected by the thermistor 15.

  In the showcase configured as described above, when the normal cooling operation is performed, the heater control unit 41 and the compressor control unit 42 open and close the switch 45 and the switch 47a as shown in FIG. And the compressor 21 is controlled. First, when the switch 44 is open, that is, when the current from the power supply 43 is interrupted, the switch 45 and the switch 47a are open. Although the switch 46 is closed, the compressor 21 is not energized unless a current flows from the contact 45a. When the switch 44 is closed, a current flows in the circuit, and the compressor control unit 42 closes the switch 45 if the temperature detected based on the detection signal output from the thermistor 15 is higher than the temperature for driving the compressor 21. . As a result, a current also flows through the switch 46 and the compressor 21 is driven. Then, the refrigerant discharged from the compressor 21 flows through the condenser 22, the expansion valve 24, and the evaporator 13. By circulating the refrigerant in this manner, the air in the ventilation path 12 is cooled by the evaporator 13, and the cooled air is discharged from the air discharge port 12a and sucked from the air intake port 12b. Is formed, and the inside of the product storage unit 11 is cooled.

  Next, to drive the heater 16a, as shown in FIG. 6, the heater control unit 41 detects the temperature in the product storage unit 11 based on the detection signal output from the thermistor 15 (S1), and stores the product. When the temperature in the section 11 is equal to or lower than the temperature at which the heater 16a is stopped (S2), the switch 47a is closed (S3). As a result, the heater 16a is energized to warm the air inlet 12b, and condensation of the air inlet 12 due to cooled air is prevented.

  Further, for example, after the defrosting operation of the evaporator 13 is performed, the temperature of the product storage unit 11 rises after the defrosting operation. At that time, as shown in FIG. 7, the heater control unit 41 always detects the temperature in the product storage unit 11 (S5), and when the temperature in the product storage unit 11 becomes higher than the temperature at which the heater 16a is stopped ( S6), the switch 47a is opened (S7). As a result, the driving of the heater 16a is stopped and power is not consumed more than necessary.

  Thus, according to the showcase of the present embodiment, the compressor 21 is controlled based on the temperature of the product storage unit 11 detected by the thermistor 15, and the detected temperature of the thermistor 15 is higher than a predetermined temperature. Since the heater 16a is sometimes stopped and the heater 16a is driven when the temperature is lower than a predetermined temperature, it is possible to save energy without consuming more power than necessary. In addition, since a temperature detection component for controlling the heater 16a is not required, the cost can be reduced.

  Below, the structure at the time of arrange | positioning a some heater is demonstrated as the 2nd Embodiment of this invention.

  FIG. 8 is a side sectional view of the showcase, and FIG. 9 is a control circuit diagram. In FIGS. 8 and 9, parts having the same configurations as those in the above embodiment are given the same reference numerals, and description thereof is omitted. As shown in FIG. 8, when the heaters 16b and 16c are driven by disposing a plurality of heaters 16b and 16c on the upper end portion of the showcase body 10, the upper end portion of the showcase body 10 is warmed and condensation on the upper end portion is prevented. Is done. Further, the control circuit of the present embodiment is configured as shown in FIG. 9, and each heater 16a, 16b, 16c is connected in parallel to the power source 43 and connected in series to the switch 47a. Has been. The heater control unit 41 detects the temperature in the product storage unit 11 based on the detection signal output from the thermistor 15, and closes the switch 47a when each temperature becomes lower than the temperature at which the heater 16a is stopped. When the heaters 16a, 16b, and 16c are driven and the temperature becomes higher than the temperature at which the driving is stopped, the switch 47a is opened to stop the driving of the heaters 16a, 16b, and 16c. Thus, since the heater control part 41 controls opening and closing of the switch 47a, each heater 16a, 16b, 16c is driven or stopped simultaneously.

  According to the present embodiment, a plurality of heaters 16a, 16b, and 16c are connected in parallel to the power source 43, and each heater is connected in series to the switch 47a. 11 is detected, the switch 47a is closed when the temperature of the heater 16a is stopped or lower, and the heaters 16a, 16b, and 16c are driven. When the temperature is higher than the temperature at which the drive is stopped, the switch 47a is opened. Since the driving of the heaters 16a, 16b, and 16c is stopped, the heaters 16a, 16b, and 16c can be driven or stopped at the same time, and condensation can be reliably prevented at a plurality of locations in the showcase. .

  Next, as a third embodiment of the present invention, a circuit configured differently from the second embodiment will be described.

  FIG. 10 is a control circuit diagram of the present embodiment, and parts having the same configurations as those of the above-described embodiment are denoted by the same reference numerals. In the present embodiment, switches 47a, 47b, 47c are connected in series to the heaters 16a, 16b, 16c, respectively. The heater control unit 41 is set with a temperature for stopping the heater for each heater, detects the temperature in the product storage unit 11 based on the detection signal output from the thermistor 15, and drives for each heater. Compare to the temperature at which to stop. If the detected temperature is equal to or lower than the temperature at which the drive is stopped, the heater control unit 41 closes the switch directly connected to the heater whose temperature is compared, and if the detected temperature is high, the heater controller 41 switches the switch directly connected to the heater whose temperature is compared. open. Thus, since the heater control part 41 controls opening and closing of each switch 47a, 47b, 47c, each heater 16a, 16b, 16c is driven or stopped based on the temperature set for each heater.

  According to the present embodiment, the heaters 16a, 16b, and 16c are connected in parallel to the power source 43, and the switches 47a, 47b, and 47c are connected in series to the heaters. If the temperature in the unit 11 is detected and the temperature is equal to or lower than the temperature at which driving is stopped, the switch corresponding to the heater whose temperature is compared is closed, and if the temperature is higher than the temperature at which driving is stopped, the switch corresponding to the heater whose temperature is compared is Since it opens, it can drive or stop for every heater based on the set temperature, and it can prevent dew condensation reliably with appropriate power consumption in each of a plurality of locations in the showcase.

  In the above-described embodiment, the heater 16a is disposed at the upper part of the air inlet 12b. However, the heater 16a may be provided at the intermediate portion on the front side of the ventilation path 12. Moreover, you may provide the heater 16a in the air discharge port 12a.

  Further, in the above-described embodiment, the temperature at which the heater 16a is stopped is set in advance. However, the temperature may be appropriately set by inputting an operation button or the like.

The perspective view of the showcase which shows the 1st Embodiment of this invention Side cross-sectional view of showcase Block diagram of refrigerant circuit Showcase control circuit diagram Block diagram showing the control system Flow chart of control method Flow chart of control method Side surface sectional drawing of the showcase which shows the 2nd Embodiment of this invention Control circuit diagram of a showcase showing the second embodiment of the present invention Control circuit diagram of a showcase showing a third embodiment of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Showcase main body, 11 ... Merchandise storage part, 12 ... Ventilation path, 12a ... Air discharge port, 12b ... Air suction port, 13 ... Evaporator, 15 ... Thermistor, 16a, 16b, 16c ... Heater, 21 ... Compressor , 22 ... condenser, 24 ... expansion valve, 30 ... refrigerant circuit, 40 ... control unit, 41 ... heater control unit, 42 ... compressor control unit.

Claims (3)

The product storage provided in the showcase body, the refrigerant circuit connecting the evaporator, condenser, expansion means and compressor, and the air sucked from the product storage are cooled by the evaporator and stored. The show is provided with a ventilation path for discharging into the storage, a heater for preventing condensation, and a temperature detection means for detecting the temperature in the product storage, and the compressor is controlled based on the temperature detected by the temperature detection means. In case
A showcase comprising heater control means for stopping the heater when the temperature detected by the temperature detection means is higher than a predetermined temperature and driving the heater when the temperature is lower than the predetermined temperature. A plurality of the heaters are provided, and each heater is connected in parallel to the power source, and a switch for opening and closing an energization circuit to each heater is connected in series to each heater,
The heater control unit is configured to turn off the switch when the temperature detected by the temperature detection unit is higher than a predetermined temperature, and to turn on the switch when the temperature is lower than the predetermined temperature. The showcase according to claim 1. A plurality of the heaters are provided, the heaters are connected in parallel to the power source, and a plurality of switches for opening and closing the energization circuits to the heaters are connected in series to the heaters, respectively.
The heater control means compares the detected temperature of the temperature detecting means with a predetermined temperature set for each heater, switches off the heater whose detected temperature is higher than the predetermined temperature, and sets the predetermined temperature The showcase according to claim 1, wherein the heater is switched on as follows.

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