JP4462501B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator that melts frost attached to a cooler that cools the inside of a refrigerator with a heater and defrosts the frost.

  In patent documents 1-5, the refrigerator which distributes the cooler of a cooling device in a store | warehouse | chamber, and cools the inside of a store | warehouse | chamber with this cooler is disclosed. In the refrigerator, frost adheres due to the cooler becoming cold, and this reduces the cooling capacity of the cooler.

  For this reason, as shown in Patent Document 1, it is known that a defrost heater is disposed in a cooler, and frost attached to the cooler is melted and defrosted by the defrost heater. In addition, a drain pan is disposed below the cooler, and water droplets generated by the defrosting are received by the drain pan and drained to the outside of the refrigerator main body through a drain pipe (Patent Document). 1 (see FIG. 1).

Japanese Patent Laid-Open No. 2002-174483 (FIGS. 1 and 3) JP 2001-215077 A (FIG. 1) Japanese Patent Laid-Open No. 11-248331 (FIGS. 1 and 2) JP 2001-324248 A (FIG. 1) Japanese Patent Laying-Open No. 2004-251480 (FIG. 2-3)

  Since the drain pan is cooled to a low temperature by the cool air in the cabinet, water droplets from the cooler may freeze and not be drained. In this case, as shown in Patent Documents 4 and 5, a heater is provided on the drain pan, and the drain pan is warmed during defrosting to prevent the water droplets from freezing. However, there is a problem in that the power consumption of the refrigerator is increased by the amount of heater provided in the drain pan.

  Then, the objective of this invention is providing the refrigerator which can suppress the increase in power consumption, being able to drain | drain defrost water from a cooler reliably, without making it freeze.

  As shown in FIGS. 1 to 3, the refrigerator targeted by the present invention includes a cooler 3 that cools the interior 2, a defrost heater 9 that heats the cooler 3 to defrost, and the defrost. A drain pan 10 that receives the defrost water generated in the cooler 3, a temperature detection means 7 that detects the temperature of the cooler 3, and a drain pipe 11 that is connected to the drain pan 10 and drains the defrost water out of the refrigerator body 1. A drain pipe heater 12 for heating the drain pipe 11 and a control means 30 for turning on the defrost heater 9 and the drain pipe heater 12 in response to the start of defrosting of the cooler 3. 9 is provided in the lower part of the cooler 3, and a drain pan 10 is arranged below the defrost heater 9.

As shown in FIGS. 4 and 5, the control means 30 of the present invention has a temperature D detected by the temperature detection means 7 higher than the melting point (0 ° C.) of ice after defrosting of the cooler 3 is started. When a preset time elapses after the preset timing start temperature D1 or higher (YES in step S3) (YES in step S7), only the defrost heater 9 is temporarily turned off (step S8). When a preset time has elapsed since the temporary turning off (YES in step S11), the defrost heater 9 is turned on again (step S12). After a preset time has elapsed (YES in step S15), the defrost heater 9 is turned off again (step S16), and when a preset time has elapsed since the defrosting heater 9 is turned off again (YES in step S19), the drain pipe heater 12 is turned off. (Step S20).

  Here, the time for temporarily turning off the defrost heater 9 is such that the drain pan 10 heated by turning on the defrost heater 9 is cooled to a temperature at which the defrost water on the drain pan 10 is frozen by turning off the defrost heater 9. Is set to be shorter than the set time. The time from when the defrost heater 9 is turned off again to when the drain pipe heater 12 is turned off is set so that the drainage of the defrost water is surely completed from the start of the defrosting until the drain pipe heater 12 is turned off. Is done.

Further, the control means 30 preliminarily detects the temperature D detected by the temperature detection means 7 higher than the timing start temperature D1 before the preset time elapses after the detected temperature D becomes equal to or higher than the timing start temperature D1. When the temperature is equal to or higher than the set first off temperature D2 (NO in step S7 and YES in step S6), the defrost heater 9 is forcibly temporarily turned off, and a preset time after the defrost heater 9 is turned on again. If the detected temperature D becomes equal to or higher than a preset second off temperature D3 higher than the first off temperature D2 before the time elapses (NO in step S15 and YES in step S14), the defrost heater 9 is forcibly re-entered. you off.

  In addition, the control unit 30 performs the above-mentioned removal when a preset time has elapsed since the state in which the temperature D detected by the temperature detection unit 7 is equal to or higher than the timing start temperature D1 continues for a predetermined duration or longer. The frost heater 9 can be temporarily turned off.

  According to the present invention, the defrost heater 9 is provided in the lower part of the cooler 3 and the drain pan 10 is arranged below the defrost heater 9, so that the cooler 3 is turned on when the defrost heater 9 is turned on. At the same time, the drain pan 10 can be warmed, and the defrost water from the cooler 3 can be prevented from freezing on the drain pan 10 without providing a heater in the drain pan 10. The power consumption of the refrigerator can be reduced to the extent that the heater does not have to be arranged on the drain pan 10, and the temperature rise of the interior 2 at the heater arranged on the drain pan 10 can be suppressed.

  Since the defrosting heater 9 is turned on until the defrosting is almost completed and the temperature D detected by the temperature detecting means 7 becomes equal to or higher than the first off-temperature D2 and the timing start temperature D1 higher than the melting point of ice, the cooler 3 It is possible to reliably perform defrosting. In addition, since the defrost heater 9 is temporarily turned off and then turned on again, the cooler 3 and the drain pan 10 that have been gradually lowered in temperature due to the defrost heater 9 being turned off are warmed again, and the cooler 3 and the drain pan 10 are drained. It is possible to reliably prevent the defrost water remaining in the drain pan 10 and the like from being frozen before being drained. In addition, the power consumption of the defrost heater 9 can be reduced by the amount of the off period of the defrost heater 9, and the temperature rise in the interior 2 due to the defrost heater 9 can be reduced.

  Since sufficient time has passed after the defrosting is completed and the drainage of the cooler 3 and the drain pan 10 has been reliably completed, the drain pipe heater 12 is turned off, so that the defrost water remains in the drain pipe 11. In this state, it is possible to reliably prevent the defrost water from being frozen by cooling the cold air from the interior 2 of the drain pipe 11 and reliably drain the defrost water out of the refrigerator main body 1.

  Drawing shows the refrigerator which this invention makes object. Refrigerators include commercial refrigerators or freezers, refrigerated or frozen showcases, and the like. The front surface of the interior 2 of the refrigerator body 1 is open, and the front surface of the refrigerator body 1 is opened and closed by a plurality of doors 16 and 16 arranged vertically.

  As shown in FIG. 1 and FIG. 2, the interior 2 has a cooler 3 disposed on the ceiling of the interior 2 to cool the interior 2, and a ceiling surface of the interior 2, which is more than the cooler 3. A fan support plate 5 attached to the front side, a pair of left and right internal fans 6 and 6 that are attached to the fan support plate 5 and send the air in the internal compartment 2 to the cooler 3 side, and air inflow to the cooler 3 A defrosting temperature sensor (temperature detecting means) 7 arranged on the side to detect the temperature of the cooler 3, a defrosting heater 9 provided at the lower end of the cooler 3, and a lower side of the cooler 3. The drain pan 10, the drain pipe 11 connected to the connection pipe 10 a provided on the drain pan 10, the drain pipe heater 12 for heating the upper portion of the drain pipe 11, and the cover that covers the lower side of the fan support plate 5 and the drain pan 10. 13 etc. are arranged.

  The cooler 3 forms a cooling device 21 together with the compressor 19 and the condenser 20 disposed on the upper side of the refrigerator main body 1, and the refrigerant circulates through the cooler 3, the compressor 19, the condenser 20, and the like. To cool the cooler 3. The drain pan 10 is arranged in an inclined shape in which the connecting pipe 10a side is lowered, and the cooler 3 is also arranged in an inclined shape in which the connecting pipe 10a side is lowered accordingly. The defrosting temperature sensor 7 is disposed in a state in contact with the inlet side of the cooler 3 in the refrigerant passage pipe in the cooler 3. The fan support plate 5 holds each internal fan 6 in a posture facing diagonally downward and facing the front side of the internal chamber 2. The defrost heater 9 defrosts by heating the cooler 3. Since the cooler 3 and the drain pan 10 are inclined as described above, the defrost heater 9 can be brought close to the drain pan 10 in the entire drain pan 10, and when the defrost heater 9 is turned on, the drain pan together with the cooler 3. 10 is definitely warmed.

  The drain pan 10 receives the defrosted water generated in the cooler 3 by the defrosting and covers the lower side of the cooler 3 so as to restrict the air supply from the internal fans 6 through the cooler 3. ing. As shown in FIG. 2, the drain pipe 11 is connected to a drain port 23 disposed in the bottom surface 1 a of the refrigerator main body 1 through the outer peripheral wall 22 of the heat insulating structure, and the defrost water received by the drain pan 10 is stored in the refrigerator main body. 1 It drains outside. The drain port 23 is also configured to discharge water accumulated on the bottom surface of the interior 2. Note that a part of the cool air in the cabinet 2 has entered the drain pipe 11, and the upper side of the drain pipe 11 is cooled by this cool air.

  In the cabinet 2, shelves 17 for placing the articles to be stored are arranged in a plurality of stages. On the upper front surface of the refrigerator body 1, an operation switch 25 (FIG. 3) for setting the internal temperature, a display unit 26 (FIG. 3) for displaying the internal temperature, and the like are arranged. As shown in FIG. 1, the cover 13 is provided with a plurality of ventilation holes 27 at the front portion facing the internal fans 6 and 6.

  As shown in FIG. 3, a control unit (control means) 30 that performs on / off control of the cooling device 21 and the heaters 9 and 12 is disposed inside the refrigerator body 1. The control unit 30 has various timers and memories.

  The controller 30 detects the internal temperature detected by the internal temperature sensor 31 so that the internal temperature is maintained within the temperature range set by the operation of the operation switch 25 during the normal cooling operation. On / off control of the cooling device 21 is performed based on the above. In other words, the controller 30 turns on the cooling device 21 and turns on and rotates the internal fan 6. 6, whereby the cold air in the internal compartment 2 is sent to the cooler 3 by the internal fan 6 and 6. After being cooled by the cooler 3, the air is sent from the rear side of the cooler 3 to the back side of the interior 2, whereby the cool air circulates in the interior 2. The in-compartment temperature sensor 31 is arranged at an appropriate place in the in-compartment 2.

  Further, when the defrosting is started at the preset defrosting time, the control unit 30 turns off the cooling device 21 and turns on the heaters 9 and 12 respectively. As a result, the frost adhering to the cooler 3 is melted, and the drain pan 10 and the drain pipe 11 are warmed, and the defrosted water generated by melting the frost is drained from the drain port 23 without freezing. The control unit 30 may arbitrarily start defrosting by operating the operation switch 25. In addition, the drain pan 10 receives dew that has been condensed and dripped by the cooler 3, and a lump of frost that has fallen from the cooler 3. The frost mass is melted by the heat of the defrost heater 9 and drained.

  The defrosting operation of the refrigerator will be specifically described with reference to the flowcharts of FIGS. 4 and 5 and the timing chart of FIG. In addition, each below-mentioned 1st-5th timer is reset at the time of the start of a defrost operation. When the defrosting operation is started (time t0), the defrosting mode is set in step S1. That is, the control unit 30 turns off the cooling device 21, turns off the internal fans 6 and 6, and turns on the defrost heater 9 and the drain pipe heater 12, respectively. Thereby, the frost adhering to the cooler 3 is melted, and the defrost water generated by melting the frost is drained from the drain port 23 through the drain pan 10 and the drain pipe 11 without freezing. At this time, the display unit 26 displays that defrosting is in progress.

  Next, after starting the time measurement by the first timer in step S2, the control unit 30 starts the time measurement in which the temperature (detected temperature) D of the cooler 3 detected by the defrost temperature sensor 7 is set in advance in step S3. It is determined whether or not a state in which the temperature (for example, 4 ° C.) is equal to or higher than D1 and is equal to or higher than the timing start temperature D1 is continued for a predetermined duration (for example, 10 seconds). By discriminating this continuation, it can be reliably discriminated that the temperature D of the cooler 3 has become the time measurement start temperature D1 or higher. As the timing start temperature D1, a temperature higher than the melting point of ice is set.

  When the temperature D of the cooler 3 is lower than the timing start temperature D1, or when the temperature does not reach the duration even when the temperature D is equal to or higher than the timing start temperature D1 (NO in step S3), the control unit 30. Determines whether the time measured TM1 in the first timer in step S4 is equal to or greater than a preset defrost time (for example, 30 minutes) T0, and the time measured TM1 in the first timer is the defrost time T0. If not reached (NO in step S4), the process returns to step S3 and the processes in and after step S3 are repeated.

  On the other hand, when the state in which the temperature D of the cooler 3 is equal to or higher than the timing start temperature D1 continues for the duration or longer (YES in step S3), the defrosting of the cooler 3 is almost completed. 3 and drain pan 10 have not yet been drained, so that control unit 30 starts measuring time in the second timer in step S5 in order to keep the defrost heater 9 on, and then in step S6 the cooler It is determined whether or not the temperature D of 3 is equal to or higher than a preset first off temperature (for example, 10 ° C.) D2 that is higher than the timing start temperature D1. Even when the time measured TM1 in the first timer becomes equal to or longer than the defrosting time T0 in step S4 (YES in step S4), the defrosting of the cooler 3 is almost completed, and the process proceeds to step S5.

  When the temperature D of the cooler 3 is lower than the first off temperature D2 in step S6 (NO in step S6), the control unit 30 determines that the time count TM2 in the second timer is preset in step S7. It is determined whether or not time (for example, 2 minutes) T1 or more. If the time measured TM2 in the second timer has not reached the first time T1 (NO in step S7), the process returns to step S6 again.

  When the temperature D of the cooler 3 becomes equal to or higher than the first off temperature D2 at time t1 (YES in step S6), the control unit 30 turns off (temporarily turns off) only the defrost heater 9 in step S8. Note that the drain pipe heater 12 is kept on. At this time, the drainage of the cooler 3 is mostly completed, and the drain pipe heater 12 is kept on so that the defrost water from the cooler 3 can be discharged from the drain outlet 23 without freezing in the drain pipe 11. Drained. In addition, the drain pan 10 is warmed by the residual heat of the defrost heater 9, and the defrost water is hardly frozen in the drain pan 10. Even when the time measured TM2 in the second timer becomes equal to or longer than the first time T1 in step S7 (YES in step S7), the process proceeds to step S8.

  Thereafter, the control unit 30 waits in step S9 until the time count TM2 in the second timer becomes equal to or greater than the first time T1, and then starts time measurement in the third timer in step S10. When the time measured TM3 by the 3 timer is equal to or greater than a preset second time (for example, 2 minutes) T2 (YES in step S11), the drain pan 10 may be cooled and the defrost water may freeze in the drain pan 10. In step S12, the defrost heater 9 is turned on again. Next, time measurement by the fourth timer is started in step S13.

  Next, the control part 30 discriminate | determines whether the temperature D of the cooler 3 is more than the preset 2nd off temperature (for example, 15 degreeC) D3 higher than 1st off temperature D2 by step S14. When the temperature D of the cooler 3 is lower than the second off temperature D3 (NO in step S14), whether or not the time measured TM4 in the fourth timer in step S15 is equal to or greater than a preset third time (for example, 2 minutes) T3. Is determined. If the time measured TM4 in the fourth timer has not reached the third time T3 (NO in step S15), the process returns to step S14.

  When the temperature D of the cooler 3 becomes equal to or higher than the second off temperature D3 in step S14 at time t3 (YES in step S14), draining of the cooler 3 and the drain pan 10 is almost completed. Turn off only 9 again. Alternatively, even when the time measured TM4 in the fourth timer becomes equal to or greater than the third time T3 in step S15 (YES in step S15), the drainage of the cooler 3 is almost completed, and the process proceeds to step S16.

  Next, after waiting in step S17 until the time measured TM4 in the fourth timer becomes equal to or greater than the third time T3, in order to continue the drain pipe heater 20 until drainage in the drain pipe 11 is completed, step S18 is performed. In step S19, it is determined whether or not the time measured TM5 in the fifth timer is equal to or greater than a preset fourth time (for example, 2 minutes) T4. When the time measured TM5 in the fifth timer becomes equal to or greater than the fourth time T4 at time t4 (YES in step S19), the drainage of the drainpipe 11 is also completed, so the drainpipe heater 20 is turned off in step S20.

  Thereafter, the normal cooling mode is set in step S21. That is, the control unit 30 turns on the cooling device 21 and turns on the internal fans 6 and 6 when the temperature D of the cooler 3 detected by the defrost temperature sensor 7 becomes, for example, 0 ° C. or less (time point t5). . The display unit 26 displays that defrosting is in progress until, for example, about time t6 when about 10 minutes have elapsed after the cooling device 21 is turned on.

  In the flowchart, in step S9, the process waits until the time count TM2 becomes equal to or greater than the first time T1, and in step S17, the process waits until the time count TM4 exceeds the third time T3. However, these wait processes are omitted. Also good. The set temperatures D1, D2, and D3 and the set times T0, T1, T2, and T4 may be set by a user or a service person using the operation switch 25 or the like.

Vertical side view showing the main part of the refrigerator according to the present invention Vertical side view of the entire refrigerator Block diagram of control system Flow chart for explaining the defrosting operation of the refrigerator Flow chart for explaining the defrosting operation of the refrigerator Timing chart for explaining the defrosting operation of the refrigerator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator main body 2 Inside 3 Cooler 6 Inside fan 7 Defrost temperature sensor 9 Defrost heater 10 Drain pan 11 Drain pipe 12 Drain pipe heater 21 Cooling device 30 Control part

Claims (2)

A cooler (3) that cools the inside (2), a defrost heater (9) that heats and defrosts the cooler (3), and a defrost generated in the cooler (3) by the defrosting A drain pan (10) for catching water, a temperature detecting means (7) for detecting the temperature of the cooler (3), and a drain connected to the drain pan (10) to drain the defrost water out of the refrigerator main body (1). The defrost heater (9) and drain pipe heater (12) are turned on in response to the start of defrosting of the pipe (11), the drain pipe (11) for heating the drain pipe (11), and the cooler (3). Control means (30) for
The defrost heater (9) is provided in the lower part of the cooler (3), and the drain pan (10) is arranged below the defrost heater (9).
After the defrosting of the cooler (3) is started, the control means (30) has a preset timing start temperature (D1) in which the detected temperature (D) in the temperature detecting means (7) is higher than the melting point of ice. ) When a preset time elapses from the above, only the defrost heater (9) is temporarily turned off, and when a preset time elapses after the defrost heater (9) is temporarily turned off, the defrost heater (9) When the preset time elapses thereafter, only the defrost heater (9) is turned off again, and when the preset time has elapsed since the defrost heater (9) is turned off again, the drain pipe heater Turn off (12)
Before the preset time elapses after the detected temperature (D) becomes equal to or higher than the timing start temperature (D1), the detected temperature (D) in the temperature detection means (7) is determined from the timing start temperature (D1). Is higher than the preset first off temperature (D2), the defrost heater (9) is forcibly temporarily turned off, and a preset time elapses after the defrost heater (9) is turned on again. Before, when the detected temperature (D) is equal to or higher than a preset second off temperature (D3) higher than the first off temperature (D2), the defrost heater (9) is forcibly turned off again. Features a refrigerator. The control means (30) is configured so that a preset time has elapsed since the state in which the temperature detected by the temperature detection means (7) is equal to or higher than the time measurement start temperature (D1) for a predetermined duration or longer. The refrigerator of Claim 1 which performs temporary turn-off of the said defrost heater (9) when it does .

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