JP2013088081A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator capable of reducing power consumption in defrosting and power consumption in pull-down while accurately determining termination of defrosting.SOLUTION: This refrigerator includes an indoor fan 6 disposed above a cooler 25 for cooling the air in a storage compartment, and allowing the air from the storage compartment to pass through the cooler 25 from a return opening 46 and the like to be distributed to the storage compartment from a supply opening 42 or the like, a tray 29 disposed below the cooler 25, a first thermistor 61 disposed in the cooler 25, a second thermistor 62 positioned roughly just below the first thermistor 61 in the tray 29, and a control means 70 determining termination of heating in a defrosting operation. The first thermistor 61 is positioned on the basis of a position of at least one of shielding members 31, 32 respectively disposed between the cooler 25 and the indoor fan 6 and between the cooler 25 and the return opening 46 in the cooler 25.

Description

  The present invention relates to a refrigerator. In particular, it relates to melting of frost attached to a cooler or the like.

  In the refrigerator, a cooling operation is performed in order to cool food in the storage room (refrigerated room, freezer room, vegetable room, etc., hereinafter referred to as the storage room). At this time, the air in the storage room is circulated by the internal fan, the air in the storage room is cooled by the cooler, and sent to the storage room, thereby cooling the food stored in the storage room. Here, when the outside air flows into the storage chamber by opening and closing the door of the refrigerator, or the moisture of the food in the storage chamber evaporates into the storage chamber, the absolute humidity of the air in the storage chamber increases. When the absolute humidity rises, moisture in the storage room air sublimates on the surface of the cooler, and frost adheres to the cooler. For this reason, for example, when the cooling operation is performed for about one day, the cooler may be covered with frost.

  When frost adheres to the cooler, the airflow resistance of the cooler increases, so the air volume of the air sent into the storage chamber decreases. Moreover, the thermal resistance between the refrigerant flowing in the cooler and the air in the storage room increases, and the refrigeration capacity decreases. Therefore, in the refrigerator, for example, defrosting is performed every predetermined time (for example, once a day) to suppress an increase in ventilation resistance and an increase in thermal resistance of the cooler.

  In order to defrost the refrigerator's cooler, for example, a refrigerator with a function of melting the frost of the cooler by adding a heater near the cooler and convection of the heater's radiant heat and the ambient air warmed by the heater is proposed Has been. However, in such a refrigerator, since the rate at which the heat of the heater leaks into the storage chamber increases, the temperature in the storage chamber rises during defrosting, which may reduce food quality. In addition, there is a problem that the amount of power consumption increases as the heater is energized.

  Moreover, the refrigerator which has a function which defrosts a cooler comprised the refrigerant circuit (hot gas defrost circuit) which can supply the refrigerant | coolant compressed to high temperature and high pressure with the compressor to a cooler, and can melt | dissolve frost. There is a refrigerator. However, hot gas defrosting (hereinafter referred to as defrosting operation) that melts frost from the inside of such a cooler (hereinafter referred to as defrosting operation) easily slides onto the tray without being completely melted. For this reason, the frost that could not be melted may block the drain hole of the tray.

  Then, the refrigerator which made the tray (henceforth a bypass piping) contact the tray through which the high-temperature refrigerant | coolant flows among piping which comprises a hot gas defrost circuit is proposed (for example, refer patent document 1). The technique described in Patent Document 1 transmits heat of the refrigerant flowing through the bypass pipe to the tray through the bypass pipe, and heats the frost that has slipped onto the tray to melt the frost. In addition, a refrigerator in which a heater is disposed as a tray heating means in a hot gas defrosting circuit has been proposed (see, for example, Patent Document 2).

  For example, in Patent Document 1, when the defrost release sensor is attached to the pipe immediately downstream of the cooler and the temperature in the pipe immediately downstream becomes higher than 3 ° C., the frost attached to the cooler is completely melted. As a result, the hot gas defrosting is finished. However, after the frost slips from the cooler during hot gas defrosting, the temperature of the cooler rises in a short time. For this reason, although the frost which slipped from the cooler to the tray is not melted, the defrosting operation may be terminated, and the slipped frost may remain on the tray.

  In order to prevent such a defrosting operation from occurring quickly, if the operation time is made longer than necessary, the power consumption during defrosting is increased. In addition, the temperature of the air in the storage room is greatly increased, which may damage food in the storage room. Furthermore, there is a possibility that the time for the operation for cooling the storage chamber to the set temperature after defrosting (hereinafter referred to as pull-down operation) is lengthened and the power consumption during pull-down is increased.

  For this reason, for example, in the technique described in Patent Document 2, the first temperature detection means (hereinafter referred to as a first thermistor) is used as a cooler, and the second temperature detection means (hereinafter referred to as a second thermistor). ) Is provided on the tray, and when the first and second thermistors are equal to or higher than the set temperature, the defrosting operation is terminated assuming that the frost on the cooler and the tray is completely melted.

JP 2007-218537 A (FIG. 1) Japanese Patent Laying-Open No. 2005-249254 (FIG. 1)

  Here, for example, the position of the internal fan, between the cooler and the internal fan, between the cooler and the return air path, by the presence or absence of a shield that limits the flow of air, etc. The flow of air entering the cooler from the storage changes. For this reason, depending on the position of the first thermistor in the cooler, the presence or absence of frost in the defrosting operation cannot be accurately determined, and the defrosting operation is performed with the frost that has not been completely melted remaining in the cooler. May be terminated.

  Similarly, depending on the position of the second thermistor in the tray, there is a possibility that the defrosting operation is terminated in a state where the frost sliding down from the cooler remains in the tray.

  For example, the above-mentioned phenomenon often occurs in hot gas defrosting, for example. In Patent Document 1 and Patent Document 2, the power consumption during defrosting is reduced and defrosting reliability is ensured in the defrosting operation. This is a trade-off, and these techniques alone do not maximize the benefits.

  The present invention has been made to solve the above-described problems, and is capable of reducing power consumption during defrosting and power consumption during pull-down while accurately determining that defrosting has been completed without residual frost. With the goal.

  The refrigerator according to the present invention includes a cooler for cooling air in a storage for storing an object to be cooled, and an air outlet that is disposed above the cooler and allows air from the storage to pass through the cooler from a return port. The internal fan for forming the flow of air to be blown from the storage to the storage, the tray having the drain hole for drainage disposed below the cooler, and the first for detecting the temperature disposed in the cooler Detection of temperature detection means, second temperature detection means arranged at a position almost directly below the first temperature detection means in the tray, and detecting the temperature, detection of the first temperature detection means and the second temperature detection means And a control means for determining the end of heating of the cooler and the tray in the defrosting operation based on the temperature related to the first temperature detecting means, the first temperature detecting means in the cooler between the cooler and the internal fan and cooling Between the container and the return port Without even one in which is disposed at a position based on the position of the shield to restrict flow of air be in one.

  According to the refrigerator according to the present invention, even when the air flow changes due to a shield between at least one of the cooler and the internal fan and between the cooler and the return port, the cooler has a lot of frost. The first temperature detection means is placed at an easy position, and the second temperature detection means is placed at a position almost directly below the first temperature detection means where a large amount of frost tends to slide on the tray. The control means can quickly and accurately determine that the frost on the container and the tray has been thawed, and for example, by increasing the detection accuracy of the appropriate heating end timing, the power consumption during the defrosting operation can be reduced. Can be reduced.

It is sectional drawing of the refrigerator which concerns on embodiment of this invention. It is a figure which shows the structure etc. of the refrigerant circuit of the refrigerator which concerns on embodiment of this invention. It is a figure which shows the air path structure of the refrigerator which concerns on embodiment of this invention. It is a figure which shows the cooling chamber 7 of the refrigerator which concerns on embodiment of this invention. It is a figure which shows the liquid receiving part 8 of the refrigerator which concerns on embodiment of this invention. It is cooling chamber sectional drawing (the 1) of the refrigerator which concerns on embodiment of this invention. It is cooling room sectional drawing (the 2) of the refrigerator which concerns on embodiment of this invention. It is cooling room sectional drawing (the 3) of the refrigerator which concerns on embodiment of this invention. It is cooling room sectional drawing (the 4) of the refrigerator which concerns on embodiment of this invention. It is a block diagram which shows the apparatus structure of the control system which concerns on embodiment of this invention. It is a figure which shows the temperature change at the time of the defrost operation which concerns on embodiment of this invention. It is a figure which shows the flowchart of the defrost operation control which concerns on embodiment of this invention.

Embodiment.
FIG. 1 is a sectional view of a refrigerator according to an embodiment of the present invention. As shown in FIG. 1, the refrigerator has a refrigerator compartment 1, a freezer compartment 4, a vegetable compartment 5, an ice making compartment 2 for storing ice, and a freezer compartment 4 for storing stored items (food, etc.) in an outer shell that is a heat insulating box. As an example, a case in which the switching chamber 3 that can be switched to the temperature zone of the refrigerator compartment 1 is partitioned and provided. Here, in the following description, unless otherwise specified, the refrigerator compartment 1, the ice making compartment 2, the switching compartment 3, the freezer compartment 4, and the vegetable compartment 5 are collectively referred to as a storage compartment.

  Moreover, as shown in FIG. 1, the refrigerator of this Embodiment has the cooling chamber 7 in the back side. And in the cooling chamber 7, it has the cooler 25, the internal fan 6, the liquid receiving part 8, the 1st shielding object 31, and the 2nd shielding object 32. FIG. The cooler 25 cools the air in the storage chamber by exchanging heat with the refrigerant passing through the inside during normal operation of the refrigerator. Here, the cooler 25 according to the present embodiment has, for example, a fin tube structure in which fins for increasing the heat transfer area of a heat transfer tube through which a refrigerant passes are fixed and fixed in a plurality of rows in the front-rear direction of the refrigerator. It is assumed that the heat transfer tubes are lined up. The internal fan 6 is a blower that forms an air flow (a flow for circulating the air in the storage) that allows the air from the storage to pass through the cooler 25 and sends the cooled air into the storage chamber again. Here, the internal fan 6 is disposed above the cooler 25.

  The liquid receiver 8 has equipment for receiving frost melting water (drain water) dripping from the cooler 25, frost sliding down, etc. during the defrosting operation. The first shielding object 31 and the second shielding object 32 are, for example, in the cooling chamber 7, and restrict the air flow by the internal fan 6 by changing it. Here, the first shield 31 is between the upper part of the cooler 25 and the internal fan 6. Although not particularly limited, for example, a guide for guiding the air cooled by the cooler 25 to the internal fan 6 is the first shield 31. The second shield 32 is located between the lower part of the cooler 25 and a return port 46 described later. Although not particularly limited, for example, a heater or the like for heating the cooler 25 from the outside serves as the second shield 32.

  FIG. 2 is a diagram illustrating a configuration of a refrigerant circuit of the refrigerator according to the embodiment. As shown in FIG. 2, the refrigerator according to the present embodiment connects, for example, a compressor 21, a flow path switching valve 22, a condenser 23, a capillary tube 24, a cooler 25, a header 26, a bypass pipe 27, and a tray pipe 28. Thus, a refrigerant circuit is configured.

  The compressor 21 compresses the gas-phase refrigerant sucked from the suction side to high pressure and high temperature, and sends it out from the discharge side. Here, the discharge side of the compressor 21 is connected to the flow path switching valve 22 via the refrigerant pipe, and the suction side is connected to the header 26 via the refrigerant pipe.

  The flow path switching valve 22 serving as switching means switches the flow of the refrigerant sent out from the compressor 21. For example, the refrigerant has an inlet A1, an outlet A2, and an outlet A3, and selects whether to connect the inlet A1 and the outlet A2 or to connect the inlet A1 and the outlet A3 by switching. be able to. Here, inflow port A1 is connected with the discharge side of compressor 21 via refrigerant piping. The outlet A2 is connected to the condenser 23 via a refrigerant pipe. The outlet A3 is connected to the bypass pipe 27. And when the connection which forms a flow path between inflow port A1 and outflow port A2 is made, the air of a refrigerator is cooled by cooling the cooler 25. FIG. Hereinafter, the connection that forms the flow path between the inlet A1 and the outlet A2 is referred to as “normal connection”, and the operation of cooling by the cooler 25 by the normal connection is referred to as “normal operation”. Moreover, when the connection which forms a flow path between inflow port A1 and outflow port A3 is carried out, the cooler 25 is heated with the refrigerant | coolant from the compressor 21 of the cooler 25. FIG. Hereinafter, the connection that forms the flow path between the inflow port A1 and the outflow port A3 is referred to as “defrost connection”, and the operation in the defrost connection state is referred to as “defrost operation”.

  The condenser 23 condenses the high-temperature and high-pressure gas-phase refrigerant from the compressor 21 by, for example, heat exchange with air outside the refrigerator when the flow path switching valve 22 is normally connected. The condenser 23 has a refrigerant inlet side connected to the flow path switching valve 22 via a refrigerant pipe, and a refrigerant outlet side connected to the capillary tube 24 via the refrigerant pipe.

  The capillary tube 24 serving as a decompression means (a throttling device) decompresses the liquid-phase refrigerant flowing from the condenser 23 into a low-temperature and low-pressure gas-liquid two-phase state. The capillary 24 has a refrigerant inlet side connected to the condenser 23 via a refrigerant pipe, and a refrigerant outlet side connected to the cooler 25 via a bypass pipe 27 and a tray pipe 28.

  For example, the tray pipe 28 is disposed on the lower surface of a tray 29 described later, and is fixed in contact with the tray 29 with a metal tape (not shown) having high thermal conductivity. Thereby, the tray 29 can be effectively heated during the defrosting operation, and the frost sliding down on the tray 29 can be melted. In the present embodiment, for example, a part of the pipe connecting the capillary tube 24 and the cooler 25 is configured. The refrigerant inlet side is connected to the capillary tube 24 and the bypass pipe 27, and the refrigerant outlet side is connected to the cooler 25. When the flow path switching valve 22 is normally connected and performing normal operation, the gas-liquid two-phase refrigerant that has passed through the capillary 24 passes. At this time, it functions as a subcooler and evaporates part of the liquid phase refrigerant. Further, when the flow path switching valve 22 is defrosted and performing a defrosting operation, it functions as a sub radiator, and a high-temperature and high-pressure gas phase that has passed through the flow path switching valve 22 and the bypass pipe 27 from the compressor 21. A refrigerant (which may be a gas-liquid two-phase refrigerant) is radiated. As a result, the frost sliding down on the tray 29 is melted.

  Here, for example, even if a part of the bypass pipe 27 is configured as the tray pipe 28 and the refrigerant outlet of the bypass pipe 27 is connected to the cooler 25, the tray 29 is heated in the defrosting operation, and frost is removed. Can be melted. Further, a part of the pipe connecting the cooler 25 and the compressor 21 is configured as a tray pipe 28 so that the refrigerant inlet side is connected to the cooler 25 and the refrigerant outlet side is connected to the compressor 21. In the defrosting operation, the tray 29 can be heated to melt the frost. Further, the tray 29 may be heated by heating means such as a pipe heater without arranging the tray pipe 28. At this time, the refrigerant outlet side of the bypass pipe 27 is connected to the cooler 25.

  As described above, when the flow path switching valve 22 is normally connected and performing the normal operation, the cooler 25 is connected to the low-temperature and low-pressure refrigerant in the gas-liquid two-phase state fed through the tray pipe 28 and the storage chamber. It is vaporized by evaporating air with heat. At this time, the air in the storage chamber is cooled. Further, when the flow path switching valve 22 is defrosted and performing a defrosting operation, it functions as a radiator and may be a high-temperature and high-pressure gas-phase refrigerant (gas-liquid two-phase refrigerant that has passed through the tray pipe 28 in some cases). ) Is radiated and heated from the inside to melt and defrost the frost.

  The header 26 separates the liquid-phase refrigerant from the refrigerant flowing from the cooler 25 through the refrigerant pipe, and causes the compressor 21 to suck the gas-phase refrigerant. The header 26 has a refrigerant inlet side connected to the cooler 25 via a refrigerant pipe, and a refrigerant outlet side connected to the suction side of the compressor 21 via the refrigerant pipe.

  The bypass pipe 27 passes the condenser 23 and the capillary 24 through the high-temperature and high-pressure gas-phase refrigerant (which may be a gas-liquid two-phase refrigerant) discharged from the compressor 21 when the flow path switching valve 22 is defrosted. The tray pipe 28 and the cooler 25 are allowed to pass through. The bypass pipe 27 has a refrigerant inlet side connected to the flow path switching valve 22 and a refrigerant outlet side connected to the tray pipe 28.

  FIG. 3 is a diagram showing the structure of the air path in the refrigerator according to the embodiment. Here, a refrigerator in which the refrigerator compartment 1, the ice making compartment 2, the switching compartment 3, and the freezer compartment 4 are connected by an air passage from the cooling compartment 7 and the vegetable compartment 5 is connected to the refrigerator compartment 1 by an air passage is taken as an example. Use.

  The air cooled by the cooler 25 is sent into the refrigerator compartment 1 from the outlet 41 of the refrigerator compartment 1 via the air passage A connecting the cooling compartment 7 and the refrigerator compartment 1 by the internal fan 6. Since the air in the refrigerator compartment 1 exchanges heat with food in the refrigerator compartment 1, air that flows in from the outside of the refrigerator when the door of the refrigerator compartment 1 is opened and closed, the temperature rises. In addition, the amount of moisture in the refrigerator compartment 1 increases due to the inflow of air having a high absolute humidity.

  Next, the air in the refrigerator compartment 1 flows into the air path B connecting the refrigerator compartment 1 and the vegetable compartment 5 from the return port 46 of the refrigerator compartment 1. Some percent of the air flowing into the air passage B returns directly to the cooling chamber 7 from the return port 46 without passing through the vegetable chamber 5. The rest flows into the vegetable compartment 5 from the outlet 44 of the vegetable compartment 5. The air that has flowed into the vegetable compartment 5 rises in temperature and amount of water, as does the air in the refrigerator compartment 1. Then, the return port 46 returns to the cooling chamber 7.

  As described above, the cold air that has become hotter and humider than when it is sent out from the cooling chamber 7 is heat-exchanged in the cooler 25, becomes cold air of low temperature and low humidity again, and is then sent out to the refrigerating chamber 1. Frost due to dehumidified moisture is preferentially attached to the vicinity of the cooler 25 located upstream of the air flow passing through the cooler 25 and closer to the return port 46.

  The air cooled by the cooler 25 is sent into the freezer compartment 4 from the outlet 43 of the freezer compartment 4 by the internal fan 6. Since the air in the freezer compartment 4 exchanges heat with food in the freezer compartment 4, air that flows in from the outside of the refrigerator by opening and closing the door of the freezer compartment 4, the temperature rises. In addition, the amount of water in the freezer compartment 4 increases due to the flow of air with high absolute humidity. However, when the internal volume of the freezer compartment 4 is smaller than the refrigerator compartment 1, the amount of water contained in the air in the freezer compartment 4 is less than that of the refrigerator compartment 1. Next, the air in the freezer compartment 4 returns from the return port 45 to the cooling chamber 7.

  FIG. 4 is a diagram showing the configuration of the cooling chamber 7 of the refrigerator according to the embodiment. Moreover, FIG. 5 is the figure which looked at the liquid receiving part 8 of the refrigerator which concerns on embodiment from the upper surface side. As shown in FIGS. 4 and 5, the liquid receiving unit 8 includes a tray 29 and the tray pipe 28 described above. As shown in FIG. 4, in the present embodiment, the tray pipe 28 is disposed on the lower surface of the tray 29. However, if it is a position where heat can be transmitted to the tray 29 during the defrosting operation, it may be disposed on the upper surface side of the tray 29, for example.

  The tray 29 receives molten water and frost that slide down from the cooler 25. Here, by configuring the tray 29 with a metal material having a high thermal conductivity, the frost that has slipped down can be melted effectively by heating it during the defrosting operation. When the tray pipe 28 is provided on the upper surface side of the tray 29, the material of the tray 29 may be made of a material having a low thermal conductivity and good heat insulation, such as a polymer material. Furthermore, the material of the tray 29 may be made of, for example, a metal material having a high conductivity, and a heat insulating material having a lower heat conductivity than the tray 29 and a good heat insulating property may be provided on the lower surface of the tray 29. Thereby, it becomes difficult for the heat | fever of a refrigerant | coolant to conduct to parts other than frost, for example, the cooling chamber 7, etc. at the time of a defrost operation, and useless heat dissipation can be suppressed.

  A drain hole 30 is provided in the center of the tray 29. Melted water of frost that has slipped down to the liquid receiver 8 or melted water of frost that has melted in the liquid receiver 8 flows through the drain pipe 9 that leads to the drain hole 30 and is drained to the evaporating dish 10. Here, since the drain hole 30 has a mesh structure, it is possible to prevent unmelted frost from flowing into the drain pipe 9 and freezing in the middle of the drain pipe 9.

  The water (drain water) stored in the evaporating dish 10 is vaporized by, for example, heat generated by operating the compressor 21, air sent by a fan arranged in the machine room, and the like, and is discharged outside the refrigerator. The

  Here, the frost that has slipped into the drain hole 30 has a small contact area with the tray 29, and therefore, the amount of heat transferred from the tray pipe 28 by heat conduction is insufficient, and is difficult to melt. Therefore, as shown in FIG. 5, a part (I) of the tray pipe 28 is arranged in the vicinity of the drain hole 30, and the amount of heat supplied to the vicinity of the drain hole 30 is increased, so that the drain hole 30 is caused by the frost that has fallen. Blocking can be prevented. For example, when the tray pipe 28 is provided on the upper surface of the tray 29, a part (I) of the tray pipe 28 may pass through the drain hole 30.

  The first thermistor 61 is attached to the cooler 25 and detects the temperature of the cooler 25. Based on the temperature of the cooler 25 detected by the first thermistor 61, the control means 70 described later determines the end of the defrosting operation. Here, the first thermistor 61 is attached to the upstream of the cool air flowing from the storage chamber to the cooling chamber 7 in the cooler 25 and in the vicinity of the return opening of the air passage, and the surface of the cooler 25 has a large amount of frost formation. It is desirable to detect the temperature at. If the first thermistor 61 determines that the frost at this position has melted completely by detecting the temperature at the position where the frost formation is considered to be the slowest, the frost is melted completely. It can be determined that the attached frost is completely melted, and even if only one first thermistor 61 is attached, the reliability of defrosting is improved.

  The second thermistor 62 is attached to the tray 29 and detects the temperature of the tray 29. Based on the temperature of the tray 29 detected by the second thermistor 62, the control means 70 described later determines the end of the defrosting operation. Here, the second thermistor 62 is attached at a position almost directly below the first thermistor 61 where the amount of frost sliding down the cooler 25 is large. When the second thermistor 62 detects the temperature at the position where the frost is most likely to fall on the tray 29, it is determined that the frost at this position has completely melted. It will be determined that it has melted, leading to improved reliability of defrosting.

  FIG. 6: is sectional drawing (the 1) which shows the structural example of the cooling chamber 7 of the refrigerator which concerns on embodiment. FIG. 6A shows a case where the first shield 31 is provided. FIG. 6B shows a case where the second shielding object 32 is provided. In FIG. 6, the internal fan 6 is located on the return port 46 side (storage side) from the central portion of the cooler 25 in the row direction (refrigerant front-rear direction) (return port on the surface where air returning from the return port 46 flows into the cooler 25. 46 position) and blows air toward the return port 46 side. And the 1st shielding object 31 or the 2nd shielding object 32 is arrange | positioned in the position near the return port 46 side from the cooler 25 row direction center part. Here, it is assumed that the return port 46 communicates with the refrigerator compartment 1 where the humidity is highest, for example.

  In the configuration of the cooling chamber 7 as shown in FIG. 6, the first shielding object 31 or the second shielding object 32 having a large pressure loss exists on the shortest distance from the return port 46 to the internal fan 6. Further, the air in the freezer compartment 4 returns from the return port 45 and merges with the air from the return port 46. For this reason, the air flowing from the return port 46 to the cooler 25 flows through the opposite side of the return port 46 from the central portion in the column direction of the cooler 25. Therefore, the first thermistor 61 is arranged on the opposite side of the return port 46 from the central portion in the column direction of the cooler 25, so that the amount of frost formed on the cooler 25 when the air flow is changed due to the shielding. It becomes possible to detect the temperature at a position where there is a lot of noise.

  FIG. 7: is sectional drawing (the 2) which shows the structural example of the cooling chamber 7 of the refrigerator which concerns on embodiment. FIG. 7A shows a case where the first shield 31 is provided. FIG. 7B shows a case where the second shielding object 32 is provided. In FIG. 7, the internal fan 6 is disposed at a position closer to the return port 46 than the central portion in the row direction of the cooler 25, and blows air toward the return port 46. And the 1st shielding object 31 or the 2nd shielding object 32 is arrange | positioned in the position near the opposite side to the return port 46 side from the cooler 25 row direction center part. Here, it is assumed that the return port 46 communicates with the refrigerator compartment 1 where the humidity is highest, for example.

  In the configuration of the cooling chamber 7 as shown in FIG. 7, the first shield 31 or the second shield 32 having a large pressure loss does not exist on the shortest distance from the return port 46 to the internal fan 6. For this reason, the air flowing from the return port 46 to the cooler 25 flows from the center portion in the column direction of the cooler 25 through the return port 46 side. Therefore, the first thermistor 61 is arranged closer to the return port 46 than the central portion in the column direction of the cooler 25, so that the amount of frost on the cooler 25 is large when the air flow changes due to the shielding. The temperature at the position can be detected.

  FIG. 8: is sectional drawing (the 3) which shows the structural example of the cooling chamber 7 of the refrigerator which concerns on embodiment. FIG. 8A shows a case where the first shield 31 is provided. FIG. 8B shows a case where the second shielding object 32 is provided. In FIG. 8, the internal fan 6 is disposed at a position on the opposite side of the return port 46 side from the central portion in the row direction of the cooler 25 and blows air toward the return port 46 side. And the 1st shielding object 31 or the 2nd shielding object 32 is arrange | positioned in the position near the opposite side to the return port 46 side from the cooler 25 row direction center part. Here, it is assumed that the return port 46 communicates with the refrigerator compartment 1 where the humidity is highest, for example.

  In the configuration of the cooling chamber 7 as shown in FIG. 8, the first shield 31 or the second shield 32 having a large pressure loss exists on the shortest distance from the return port 46 to the internal fan 6. In addition, the air flowing from the return port 46 to the cooler 25 flows from the center portion in the column direction of the cooler 25 through the return port 46 side. Therefore, the first thermistor 61 is arranged closer to the return port 46 than the central portion in the column direction of the cooler 25, so that the amount of frost on the cooler 25 is large when the air flow changes due to the shielding. The temperature at the position can be detected.

  FIG. 9: is sectional drawing (the 4) which shows the structural example of the cooling chamber 7 of the refrigerator which concerns on embodiment. FIG. 9A shows a case where the first shield 31 is provided. FIG. 9B shows a case where the second shield 32 is provided. In FIG. 9, the internal fan 6 is disposed at a position opposite to the return port 46 side from the central portion in the row direction of the cooler 25, and blows air toward the return port 46 side. And the 1st shielding object 31 or the 2nd shielding object 32 is arrange | positioned in the position near the return port 46 side from the cooler 25 row direction center part. Here, it is assumed that the return port 46 communicates with the refrigerator compartment 1 where the humidity is highest, for example.

  In the configuration of the cooling chamber 7 as shown in FIG. 9, the first shield 31 or the second shield 32 having a large pressure loss exists on the shortest distance from the return port 46 to the internal fan 6. Further, the air in the freezer compartment 4 returns from the return port 45 and merges with the air from the return port 46. For this reason, the air flowing from the return port 46 to the cooler 25 flows from the central portion in the column direction of the cooler 25 through the opposite side of the return port 46. Therefore, the first thermistor 61 is arranged on the opposite side of the return port 46 from the central portion in the column direction of the cooler 25, so that the amount of frost formed on the cooler 25 when the air flow is changed due to the shielding. It becomes possible to detect the temperature at a position where there is a lot of noise.

  FIG. 10 is a block diagram showing a device configuration of the control system according to the embodiment of the present invention. The control means 70 shown in FIG. 10 controls equipment in the refrigerator. In particular, in the present embodiment, whether or not to end the defrosting operation is determined based on the temperature related to the detection of the first thermistor 61 and the second thermistor 62. In addition, at the start and end of the defrosting operation, settings relating to the motor speed of the compressor 21 related to the refrigerant circuit, rotation and stop of the internal fan 6, and control relating to connection switching of the flow path switching valve 22 are performed.

  FIG. 11 is a diagram illustrating temperature changes of the cooler 25 and the tray 29 during the defrosting operation of the refrigerator according to the embodiment. In FIG. 11, the vertical axis represents the temperature related to detection by the first thermistor 61 (temperature of the cooler 25) and the temperature related to detection by the second thermistor 62 (temperature of the tray 29), and the horizontal axis represents defrosting. The elapsed time from the start.

  For example, in a refrigerator, a normal operation for cooling food in a storage is continuously performed for a predetermined time. During normal operation, the air exchanged with the refrigerant is sent into the storage. At this time, moisture contained in the air adheres to the surface of the cooler 25 and the like as frost, which deteriorates the efficiency of heat exchange. Therefore, the control means 70 performs a normal operation for a predetermined time (for example, about one day), and then performs the defrost operation by switching the flow path switching valve 22 to the defrost connection to remove the attached frost.

  As shown in FIG. 11, when the defrosting operation is started, the temperature of the tray 29 (including the frost on the tray 29) receives heat from the high-temperature refrigerant in the tray pipe 28 and rises to 0 ° C. (B1). On the other hand, the cooler 25 (including frost on the surface of the cooler 25) also receives heat from the high-temperature refrigerant flowing in the cooler 25 and rises to 0 ° C. (A1). Here, since the heat capacity of the cooler 25 is generally larger than the heat capacity of the tray 29, the cooler 25 becomes 0 ° C. later than the tray 29.

  When the temperature of the tray 29 reaches 0 ° C., the heat of the refrigerant is used to melt the frost of the tray 29 (phase change from solid to liquid). For this reason, the temperature of the tray 29 becomes 0 ° C. until the frost on the tray 29 is completely melted (B2). When the frost on the tray 29 is completely melted, the temperature of the tray 29 rises (B3).

  Between B1 and B3, the frost attached to the cooler 25 is also melted (A2). Then, when the frost melting of the cooler 25 proceeds to some extent, the frost slides from the cooler 25 to the tray 29. For this reason, the temperature of the tray 29 that has risen without frost rapidly decreases (B4, A2). Then, the heat of the refrigerant flowing in the tray pipe 28 is used again for melting of the frost in the tray 29 (phase change from solid to liquid) until the frost in the tray 29 is completely melted. The temperature of 29 becomes constant at 0 ° C. (B5).

  Since the frost does not exist in the cooler 25 between B4 and B5, the temperature of the cooler 25 rises (A3). On the other hand, when the frost sliding down on the tray 29 is completely melted, the temperature of the tray 29 rises again (B6). Therefore, when the temperature of the cooler 25 is equal to or higher than the first set temperature and the temperature of the tray 29 is equal to or higher than the second set temperature, the defrosting operation is terminated (B6, A3).

  FIG. 12 is a diagram showing a flowchart of defrosting operation control according to the embodiment of the present invention. Based on FIG. 12, the control at the time of the defrost operation which the control means 70 performs is demonstrated.

  When the normal operation is performed for a predetermined time (for example, about one day), the control means 70 starts the defrosting operation (S101). Here, the start of the defrosting operation is determined based on the time, but the determination criterion is not particularly limited, and when the sensor has a sensor for detecting the amount of frost formation, the determination based on the sensor detection is performed. You may make it judge.

  When the defrosting operation is started, the operation of the internal fan 6 is stopped (S102). And the flow-path switching valve 22 is switched to a defrost connection (S103). As a result, the high-temperature and high-pressure refrigerant discharged from the compressor 21 is supplied to the tray pipe 28 and the cooler 25 via the bypass pipe 27. Here, the (motor) rotation speed of the compressor 21 is fixed (S104). At this time, by setting the rotation speed to a high speed so that the discharge pressure of the compressor 21 does not exceed the specified pressure, more heat can be supplied, the defrosting time can be shortened, and the defrosting operation can be performed. Power consumption can be reduced.

  Then, the temperature related to the detection of the first thermistor 61 is detected as the temperature of the cooler 25 (S105). Further, the temperature related to the detection of the second thermistor 62 is detected as the temperature of the tray 29 (S106). Here, the temperature of the cooler 25 and the temperature of the tray 29 according to the detection may be recorded as data.

  Next, it is determined whether or not the temperature of the cooler 25 is higher than the first set temperature (S107, STEP-a). When it is determined that the temperature of the cooler 25 is equal to or lower than the first set temperature (S107; NO), the control unit 70 returns to S105 and performs determination based on the temperature of the cooler 25 again.

  On the other hand, if it is determined that the temperature of the cooler 25 is higher than the first set temperature (S107; YES), it is determined whether the temperature of the tray 29 is higher than the second set temperature (S108, STEP-b). Here, the first set temperature and the second set temperature may be set to the same temperature, or may be set to different temperatures.

  When it is determined that the temperature of the tray 29 is equal to or lower than the set temperature (S108; NO), the control unit 70 returns to S105 and performs determination based on the temperature of the cooler 25 again. Moreover, if it determines with the cooler 25 being higher than 2nd setting temperature (S108; YES), the flow-path switching valve 22 will be switched to normal connection as what defrosting complete | finished (S109). Then, the fixing of the compressor speed is released (S110), the internal fan 6 is driven (S111), and the defrosting operation is ended (S112).

  As described above, in the refrigerator according to the present embodiment, the first shield 31 and the second shield 31 are located between at least one of the cooler 25 and the internal fan 6 and between the cooler 25 and the return port 46. Even if the flow of air circulating between the storage chamber in the cooling chamber 7 is changed by the shield 32, the first thermistor 61 is arranged at a position where a lot of frost is easily formed in the cooler 25. Since the second thermistor 62 is arranged almost immediately below the first thermistor 61 where a large amount of frost is likely to slide down, the control means 70 confirms that the frost in the cooler 25 and the tray 29 has completely melted. However, it can be determined quickly and accurately, and the power consumption during the defrosting operation can be reduced. Further, it is particularly effective when there is a possibility that unmelted frost may slide onto the tray 29, such as hot gas defrosting. At this time, by disposing the first thermistor 61 at a position based on the position of the internal fan 6, the first shield 31, and the second shield 32 with respect to the cooler 25, The temperature can be detected efficiently.

  1 Refrigeration room, 2 ice making room, 3 switching room, 4 freezing room, 5 vegetable room, 6 internal fan, 7 cooling room, 8 liquid receiving part, 9 drain pipe, 10 evaporating dish, 21 compressor, 22 channel switching Valve, 23 Condenser, 24 Capillary, 25 Cooler, 26 Header, 27 Bypass piping, 28 Tray piping, 29 Tray, 30 Drain hole, 31 First shield, 32 Second shield, 41 Outlet, 42 Outlet port 43 Outlet port 44 Outlet port 45 Return port 46 Return port 61 First thermistor 62 Second thermistor 70 Control means.

Claims (4)

A cooler for cooling the air in the storage for storing the object to be cooled;
An internal fan disposed above the cooler, for allowing air from the storage to pass through the cooler from a return port, and forming a flow of air to be blown from the blowout port to the storage;
A tray disposed below the cooler and having a drain hole for drainage;
A first temperature detecting means arranged in the cooler for detecting the temperature;
A second temperature detecting means for detecting the temperature arranged at a position almost directly below the first temperature detecting means in the tray;
Control means for determining the end of heating of the cooler and the tray in the defrosting operation based on the temperature related to the detection of the first temperature detection means and the second temperature detection means,
The first temperature detection means is a shield for restricting the flow of air in the cooler, which is at least one of the cooler and the internal fan and the cooler and the return port. A refrigerator characterized by being arranged at a position based on the position of an object. When the shield is on the installation side of the return port from the central part of the refrigerator in the front-rear direction of the refrigerator,
2. The refrigerator according to claim 1, wherein the first temperature detection unit is arranged closer to the side opposite to the installation side of the return port than a central portion of the cooler in the front-rear direction of the refrigerator. When the shield is on the side opposite to the installation side of the return port from the central part of the cooler in the front-rear direction of the refrigerator,
2. The refrigerator according to claim 1, wherein the first temperature detection unit is arranged closer to the installation side of the return port than a central portion of the cooler in the front-rear direction of the refrigerator.   The refrigerator according to any one of claims 1 to 3, wherein in the defrosting operation, the heated fluid is flowed at least inside the cooler.

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