JP2013061113A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerator that can prevent frost in a tray from residing.SOLUTION: The refrigerator includes: a tray 29 for receiving frost and water which slide from a cooler 25; a first thermistor 61 disposed at the cooler 25 and detecting a temperature of the cooler 25; and a second thermistor 62 disposed at the tray 29 and detecting temperature of the tray 29 where the first thermistor 61 is disposed at an position corresponding to a return port and at an upstream side of a channel in the cooler 25, and the second thermistor 62 is disposed immediately below the first thermistor 61 in the tray 29.

Description

  The present invention relates to a refrigerator, and relates to melting of frost on a cooler and frost sliding down on a tray.

The refrigerator cools the air in the refrigerator with a cooler. The air cooled by the cooler is sent out to a storage room (a refrigeration room, a freezer room, a vegetable room, etc.) by an internal fan, and cools food stored in the storage room. Relative humidity rises in the air in this store | warehouse | chamber, when external air flows in in the store | warehouse | chamber by opening and closing the door of a refrigerator, or the water | moisture content of the foodstuff in a storage chamber is transpired in the store | chamber interior. When the relative humidity increases, the moisture in the internal air sublimates on the surface of the cooler, and frost adheres to the cooler. 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 and the air volume of air sent to the storage chamber decreases. Moreover, the thermal resistance between the refrigerant | coolant which flows in the inside of a cooler, and the air of a store room increases, and refrigerating capacity falls. Then, the refrigerator defrosts every predetermined time (for example, once a day), and suppresses the increase in ventilation resistance and thermal resistance of the cooler.

A conventional refrigerator is proposed in which a heater is attached to the cooler to defrost the cooler and has a function of melting the frost of the cooler by the radiant heat of the heater or the convection of the ambient air heated by the heater. Has been.
In addition, a refrigerator having a function of defrosting a cooler has been proposed that has a refrigerant circuit that melts frost by supplying a refrigerant compressed to a high temperature and high pressure by a compressor to the cooler.

However, when the frost adhering to the cooler is defrosted, the frost may slide onto the tray without melting. There is a possibility that the drain hole of the tray is blocked by the frost that has not melted.
Therefore, a refrigerator in which a pipe through which a high-temperature refrigerant flows (hereinafter referred to as a bypass pipe) out of pipes constituting a hot gas defrosting circuit that supplies a high-temperature refrigerant to a cooler is brought into contact with a tray has been proposed (for example, a patent). Reference 1). In the technology described in Patent Document 1, the heat of the refrigerant flowing through the bypass pipe is transmitted to the tray through the bypass pipe, and the frost that has slipped onto the tray is heated to melt the frost.
In addition to a hot gas defrosting circuit, a refrigerator has also been proposed in which a heater for heating the frost sliding down on the tray is arranged on the tray (see, for example, Patent Document 2).

JP 2007-218537 A (summary) JP-A-2005-249254 (paragraph [0034])

In the technology described in Patent Document 1, when the defrost release sensor is provided on the downstream side of the cooler and the piping temperature immediately downstream of the cooler is higher than 3 ° C, the frost attached to the cooler is completely removed. As a result of melting, the hot gas defrosting is finished.
However, in hot gas defrosting (hereinafter referred to as defrosting operation), when frost slips from the cooler during defrosting, the piping temperature of the cooler rises in a short time. For this reason, there has been a problem in that the defrosting operation is terminated and the frost remains on the tray even though the frost sliding down from the cooler to the tray is not melted.

  On the other hand, if the time for the defrosting operation is made longer than necessary, the time for the operation for cooling the interior (hereinafter referred to as normal operation) is shortened, and the interior is cooled to the set temperature after defrosting. The operation time (hereinafter referred to as pull-down) becomes longer, the amount of increase in the internal temperature increases, and the food in the storage room is damaged. Further, when the time for the defrosting operation is made longer than necessary, there is a problem that the power consumption during defrosting and pull-down (hereinafter referred to as the power consumption during defrosting operation) increases.

In the technique described in Patent Document 2, temperature detection means is provided on the toy (tray) below the cooler, and when the temperature detection means reaches a set temperature or higher, the frost on the cooler and the tray is completely melted. The defrosting operation is finished.
However, when the frost slides in a place other than the place where the temperature detection means is disposed, the defrosting operation ends and the frost remains on the tray even though the frost slipped on the tray is not melted. There was a point.

  That is, in the defrosting operation, reducing the power consumption and preventing the frost from remaining (ensuring defrosting reliability) are in a trade-off relationship, and the power consumption during the defrosting operation. There was a problem that the amount could not be reduced and the frost remaining on the tray could not be prevented.

  The present invention has been made to solve the above-described problems, and provides a refrigerator capable of preventing the frost remaining on the tray. Moreover, the refrigerator which can reduce the power consumption at the time of a defrost driving | operation is obtained.

  The refrigerator according to the present invention includes a storage room in which food is stored, a cooling room in which a cooler is disposed, a blowout port for allowing the air in the cooling room to flow out to the storage room, and the air in the storage room A return port for flowing into the cooling chamber is formed, an air passage for circulating the air in the storage chamber, a tray that is disposed below the cooler and receives frost and water sliding down from the cooler, and the cooler A first heating means for heating; a second heating means for heating the tray; a first temperature sensor provided in the cooler for detecting the temperature of the cooler; provided in the tray; A second temperature sensor for detecting the temperature of the tray, and a control means for determining the end of the defrosting operation by heating of the first and second heating means based on the detection results of the first and second temperature sensors With and before The first temperature sensor is disposed at a position upstream of the air passage and corresponding to the return port in the cooler, and the second temperature sensor is directly below the first temperature sensor in the tray. Is arranged.

  The present invention can prevent the frost from remaining on the tray. Moreover, the power consumption at the time of a defrost operation can be reduced.

It is sectional drawing of the refrigerator which shows Embodiment 1 of this invention. It is a refrigerant circuit of the refrigerator which shows Embodiment 1 of this invention. It is a figure which shows the air path structure of the refrigerator which shows Embodiment 1 of this invention. It is a figure which shows the cooling chamber of the refrigerator which shows Embodiment 1 of this invention. It is a figure which shows the liquid receiving part of the refrigerator which shows Embodiment 1 of this invention. It is a block diagram which shows the structure of the control system of the refrigerator which shows Embodiment 1 of this invention. It is a figure which shows the temperature change of the cooler and tray at the time of the defrost which shows Embodiment 1 of this invention. It is a flowchart of the defrost control which shows Embodiment 1 of this invention. It is a figure which shows the cooling chamber of the refrigerator which shows Embodiment 2 of this invention. It is a figure which shows the liquid receiving part of the refrigerator which shows Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a cross-sectional view of a refrigerator showing Embodiment 1 of the present invention.
As shown in FIG. 1, the refrigerator in the present embodiment includes a refrigerator compartment 1 for storing stored items (food, etc.), an ice making chamber 2 for storing ice, a freezer compartment and a refrigerator compartment in an outer shell that is a heat insulating box. An example will be described in which a multi-function room 3, a freezer room 4, and a vegetable room 5 that can be switched to each temperature zone are partitioned and provided. In the following description, the refrigerator compartment 1, the ice making compartment 2, the multifunctional compartment 3, the freezer compartment 4, and the vegetable compartment 5 are referred to as “storage rooms”.
As shown in FIG. 1, on the back of the refrigerator, a cooler 25 that cools the air in the refrigerator during normal operation, an internal fan 6 that sends the cooled air to the storage room, and a defrost operation There is provided a cooling chamber 7 having a liquid receiving portion 8 for receiving frost melting water or frost sliding down from the cooler 25.

  Each storage room is distinguished by a settable temperature zone (set temperature zone). For example, the refrigerator compartment 1 is about 0 ° C. to 4 ° C., the vegetable compartment 5 is about 3 ° C. to 10 ° C., and the ice making room 2 is about −18 ° C. and the freezer compartment 4 can be set to about −16 ° C. to −22 ° C., respectively. In addition, the multifunctional chamber 3 can be switched to a temperature range such as chilled (about 0 ° C.) or soft refrigeration (about −7 ° C.). The set temperature of each storage room is not limited to this.

FIG. 2 is a refrigerant circuit of the refrigerator showing the first embodiment of the present invention.
In FIG. 2, the refrigerant circuit of the refrigerator in the present embodiment has 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. ing.
In this refrigerant circuit, a compressor 21, a condenser 23, a capillary tube 24, a tray pipe 28, and a cooler 25 are sequentially connected by a pipe, and a main circuit that circulates the refrigerant and a pipe that connects the compressor 21 and the condenser 23. A bypass circuit is formed which branches from the pipe and reaches the pipe connecting the capillary tube 24 and the tray pipe 28.

  The compressor 21 compresses the gas-phase refrigerant sent to the suction side to high pressure and high temperature, and sends it out from the discharge side. 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 switches the flow of the refrigerant sent out from the compressor 21. That is, the flow path switching valve 22 has a refrigerant inlet A1, an outlet A2, and an outlet A3. Then, switching between the inflow port A1 and the outflow port A2 or the connection between the inflow port A1 and the outflow port A3 is possible.
The inflow port A1 is connected to the discharge side of the compressor 21 through a refrigerant pipe. Further, the outlet A2 is connected to the condenser 23 via the refrigerant pipe, and the outlet A3 is connected to the bypass pipe 27.
When the inlet A1 and the outlet A2 of the flow path switching valve 22 are connected, the refrigerant flow path circulates through the main circuit, the cooler 25 is cooled, and the refrigerator air is cooled. Hereinafter, the connection for switching the flow path switching valve 22 to the main circuit and circulating the refrigerant in the main circuit is referred to as “normal connection”, and the operation for cooling the cooler 25 by this normal connection is referred to as “normal operation”.
When the inlet A1 and the outlet A3 are connected in the flow path switching valve 22, the high-temperature refrigerant from the compressor 21 reaches the tray pipe 28 and the cooler 25, and the cooler 25 is heated. Then, the cooler 25 is defrosted. Hereinafter, the connection for switching the flow path switching valve 22 to the bypass circuit and supplying the high-temperature refrigerant discharged from the compressor 21 to the tray pipe 28 and the cooler 25 is referred to as “defrost connection”. The operation is referred to as “defrosting operation”.
The “bypass circuit” corresponds to the “first heating unit” in the present invention.

  The condenser 23 condenses the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 21 when the flow path switching valve 22 is normally connected. That is, it functions as a forced air-cooled condenser during normal connection. The condenser 23 has an inlet side connected to the flow path switching valve 22 via a refrigerant pipe, and an outlet side connected to the capillary 24 via the refrigerant pipe.

  The capillary 24 depressurizes the liquid-phase refrigerant sent from the condenser 23 via the refrigerant pipe to form a low-temperature and low-pressure gas-liquid two-phase state. The capillary 24 has an inlet side connected to the condenser 23 via a refrigerant pipe, and an outlet side connected to the cooler 25.

The tray pipe 28 is constituted by a part of a pipe that connects the capillary tube 24 and the cooler 25, the inlet side is connected to the capillary tube 24 and the bypass pipe 27, and the outlet side is connected to the cooler 25.
The tray pipe 28 is provided in contact with a tray 29 that catches molten water and frost that slides down from the cooler 25. The two-phase refrigerant sent from the capillary 24 when the flow path switching valve 22 is normally connected. Is evaporated. That is, it functions as a subcooler during normal connection.
Further, at the time of defrosting connection, the high-temperature and high-pressure gas-phase refrigerant or gas-liquid two-phase refrigerant sent from the compressor 21 through the flow path switching valve 22, the bypass pipe 27 and the refrigerant pipe is radiated. That is, it functions as a sub radiator at the time of defrosting connection, and the frost sliding down on the tray 29 is thereby melted.
The “tray piping 28” corresponds to the “second heating means” in the present invention.

  Here, the case where the tray pipe 28 is configured by a part of the pipe connecting the capillary tube 24 and the cooler 25 will be described, but the present invention is not limited to this. For example, the tray pipe 28 may be configured as a part of the bypass pipe 27, and the outlet of the bypass pipe 27 may be connected to the cooler 25. Further, for example, the tray pipe 28 may be configured by a part of the arrangement connecting the cooler 25 and the compressor 21, the inlet side may be connected to the cooler 25, and the outlet side may be connected to the compressor 21.

  In the present embodiment, a case where a bypass circuit that supplies high-temperature refrigerant from the compressor 21 to the cooler 25 is used as the first heating means for heating the cooler 25 will be described. The present invention is not limited, and an electric heater or the like that heats the cooler 25 may be used instead of or in addition to the bypass circuit.

  In the present embodiment, the case where the tray pipe 28 is used as the second heating means for heating the tray 29 will be described. However, the present invention is not limited to this, and instead of or together with the tray pipe 28. An electric heater or the like for heating the tray 29 may be used. When the tray pipe 28 is not disposed, the outlet side of the bypass pipe 27 is connected to the cooler 25.

The cooler 25 evaporates the low-temperature and low-pressure refrigerant in the gas-liquid two-phase state fed through the tray pipe 28 when the flow path switching valve 22 is normally connected. That is, it functions as the cooler 25 during normal connection.
In addition, when the flow path switching valve 22 is connected to defrost, the high-temperature and high-pressure gas-phase refrigerant or gas-liquid two-phase refrigerant sent through the tray pipe 28 is radiated. That is, it functions as a radiator during defrosting connection, and the frost in the cooler 25 is thereby melted.

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

  The bypass piping 27 bypasses the condenser 23 and the capillary tube 24 and flows the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 21 into the tray piping 28. The bypass pipe 27 has an inlet side connected to the flow path switching valve 22 and an outlet side connected to the tray pipe 28.

Next, the flow path structure of the refrigerator and the flow of cold air (air) in the refrigerator will be described.
FIG. 3 is a diagram showing an air passage structure of the refrigerator showing the first embodiment of the present invention.
3, the refrigerator in the present embodiment includes a refrigerator compartment 1, an ice making compartment 2, a multifunctional compartment 3, and a freezer compartment 4, each connected by an air passage from a cooling compartment 7 (see FIG. 1), and a vegetable compartment 5. It is connected to the refrigerator compartment 1 by an air passage.

The cold air generated by the cooler 25 is sent to the refrigerating room 1 from the refrigerating room outlet 41 of the refrigerating room 1 through the air passage A connecting the cooling room 7 and the refrigerating room 1 by the internal fan 6.
Since the cold air in the refrigerator compartment 1 exchanges heat with food in the refrigerator compartment 1 and air flowing in from the outside of the refrigerator when the door of the refrigerator compartment 1 is opened and closed, the temperature rises. Moreover, since the relative humidity is usually higher than the cold air in the refrigerator compartment 1 outside the refrigerator, the relative humidity also increases during heat exchange.

In addition, the cold air generated by the cooler 25 is sent out from the ice making chamber outlet 42 of the ice making chamber 2, the multifunction chamber outlet 43 of the multifunction chamber 3, and the freezer chamber outlet 44 of the freezer compartment 4 to each storage room. Similarly, the temperature and humidity rise by exchanging heat with food and air in the cabinet.
Then, the cold air that has flowed into the freezer compartment 4 returns from the freezer compartment return port 54 to the cooling chamber 7. The air flowing into the ice making chamber 2 and the multifunction chamber 3 returns to the cooling chamber 7 from the freezer return port 54 through a back air passage (not shown).

The cold air in the refrigerator compartment 1 flows into the air path B connecting the refrigerator compartment 1 and the vegetable compartment 5 from the refrigerator compartment return port 51 of the refrigerator compartment 1.
A part of the cold air flowing into the air passage B flows into the vegetable compartment 5 from the vegetable compartment outlet 45 of the vegetable compartment 5. The cold air in the vegetable room 5 further increases in temperature and relative humidity due to heat exchange as in the refrigerator room 1. Then, the cold air in the vegetable room 5 returns to the cooling room 7 from the vegetable room return port 55.
Further, the other part of the cold air flowing into the air passage B returns directly to the cooling chamber 7 from the vegetable chamber return port 55 without passing through the vegetable chamber 5.
As described above, the cool air whose temperature / humidity is higher than when it is sent out from the cooling chamber 7 is heat-exchanged in the cooler 25, becomes cold air whose temperature / humidity is lowered again, and is sent out to each storage chamber.

In such an air path for circulating the cold air, moisture in the air passing through the cooler 25 is rapidly cooled and sublimated on the upstream surface of the cool air flow of the cooler 25 and sublimates, and is upstream of the cooler 25. Frost adheres. As a result, the amount of moisture in the air decreases as it goes downstream of the cold air flow, and the amount of frost formation on the downstream side becomes relatively small. For this reason, the amount of frost formation on the upstream side of the cold air flow passing through the cooler 25 becomes larger than the amount of frost formation on the downstream side.
Further, the amount of air passing through the cooler 25 increases at a position corresponding to the return port that returns the cool air in the storage chamber to the cooling chamber 7. For example, in the example of FIG. 3, the amount of air passing through the cooler 25 is larger at the center corresponding to the position of the vegetable room return port 55 than at the side as viewed from the front. For this reason, the amount of frost formation increases in the position corresponding to the return port which returns the cool air in the storage chamber to the cooling chamber 7.
That is, frost is attached to a position corresponding to a return port (for example, the vegetable chamber return port 55) that is located upstream of the cool air flow passing through the cooler 25 and returns the cool air to the cooling chamber 7.

  Next, the arrangement of the temperature sensor (thermistor) in consideration of the frost adhesion amount as described above and the configuration of the liquid receiving unit 8 will be described.

FIG. 4 is a view showing a cooling chamber of the refrigerator showing the first embodiment of the present invention.
5A and 5B are diagrams showing a liquid receiver of the refrigerator according to the first embodiment of the present invention, where FIG. 5A is a top view and FIG. 5B is a side view.
4 and 5, the liquid receiver 8 includes a tray 29 that receives water and frost that slides down from the cooler 25, and a tray pipe 28 that is disposed on the lower surface of the tray 29.
The arrangement of the tray piping 28 is not limited to the lower surface of the tray 29. Any position where heat can be transferred to the tray 29 during the defrosting operation may be used. For example, it may be arranged on the upper surface side of the tray 29.

The cooler 25 is provided with a first thermistor 61 that detects the temperature of the cooler 25. The temperature of the cooler 25 detected by the first thermistor 61 is used to determine the end of the defrosting operation.
The first thermistor 61 is disposed at a position upstream of the cold air flowing into the cooling chamber 7 from the storage chamber and corresponding to the return port of the air passage. This makes it possible to detect the temperature at a position where the frosting amount of the cooler 25 is large.
As described above, in the example of FIG. 4, frost adheres mainly to the upstream side of the cold air flow passing through the cooler 25 and the position corresponding to the vegetable room return port 55, so the first thermistor 61 is installed. In addition, it is arranged upstream of the cooler 25 (lower side of the paper) and at a position close to the vegetable room return port 55 in a front view.
When it is arranged at a place where the amount of frost formation is large, when the frost at the place where the first thermistor 61 is arranged is completely melted, the frost attached to the cooler 25 is completely melted. Remaining frost can be prevented and defrosting reliability can be improved.

  The cool air passing through the cooler 25 may have an increased amount of passage on the back side of the cooler 25 due to, for example, an obstacle between the cooler 25 and the return port. Thus, when cold air | flow flows preferentially to the back side of the cooler 25, as shown to the side view (AA) of FIG. Deploy.

  4 shows the case where the first thermistor 61 is disposed on the back side of the cooler 25, the present invention is not limited to this, and the amount of cool air passing through the cooler 25 is the largest. You may make it arrange | position in the position which increases. The position where the amount of cold air passing through the cooler 25 is the largest and the frost is preferentially attached varies depending on the shape of the return port, the cooling chamber 7, the positional relationship, and the like. The installation position of the first thermistor 61 may be determined by checking the amount of frost formation.

The first thermistor 61 is preferably disposed at a position corresponding to the return port through which the air in the storage chamber having the highest set temperature zone among the plurality of storage chambers flows into the cooling chamber 7.
The air in the storage room with a high set temperature zone has a large amount of saturated water vapor, and therefore, the amount of moisture in the air tends to increase compared to the air in the storage room with a low set temperature zone. When the air in the storage room having a high set temperature zone is cooled by the cooler 25, the relative humidity becomes higher than the air in the storage room having a low set temperature zone, and frost adhering to the cooler 25. The amount is relatively large. In this Embodiment, as shown in FIG. 4, the 1st thermistor 61 is arrange | positioned in the position corresponding to the vegetable room return port 55 of the vegetable room 5 with the highest setting temperature zone among several storage rooms. Yes.
In this way, when the first thermistor 61 is disposed at a position corresponding to the return port of the storage chamber having the highest set temperature zone, the frost at the place where the first thermistor 61 is disposed is completely melted. The frost attached to the cooler 25 is completely melted, so that the frost can be prevented from remaining and the defrosting reliability can be improved.
Also, in the refrigerator having a plurality of storage rooms, it is not necessary to provide the first thermistor 61 at the return port from each storage room, and the position corresponding to the return port of the storage room having the highest set temperature zone, By arranging only one first thermistor 61, defrosting reliability can be ensured.

The tray 29 is provided with a second thermistor 62 that detects the temperature of the tray 29. The temperature of the tray 29 detected by the second thermistor 62 is used for determining the end of the defrosting operation.
The second thermistor 62 is preferably disposed immediately below the first thermistor 61. Thereby, it becomes possible to detect the temperature of the tray 29 at a position where the amount of frost sliding from the cooler 25 is large during the defrosting operation. When the frost is disposed at a location where the amount of frost slide is large, when the frost at the location where the second thermistor 62 is disposed is completely melted, the frost attached to the tray 29 is completely melted. Defrosting reliability can be improved.

The “first thermistor 61” corresponds to the “first temperature sensor” in the present invention.
The “second thermistor 62” corresponds to the “second temperature sensor” in the present invention.

  The tray pipe 28 is brought into contact with the tray 29 and is fixed to the tray 29 with a metal tape having high thermal conductivity. As a result, the tray 29 is effectively heated during the defrosting operation, and the frost sliding down on the tray 29 is melted.

  In addition, by comprising the tray 29 with a metal material having a high thermal conductivity, it is possible to effectively heat the frost that has slipped onto the tray 29 during the defrosting operation.

When the tray pipe 28 is provided on the upper surface of the tray 29, the material of the tray 29 may be made of a material having low thermal conductivity and good heat insulation, for example, a polymer material. Further, the material of the tray 29 may be made of, for example, a metallic 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, during the defrosting operation, it becomes difficult for the heat of the refrigerant to be transmitted to a portion other than the frost, for example, the cooling chamber 7, and wasteful heat dissipation can be suppressed.

  A drain hole 30 is provided in the center of the tray 29, and the frost melting water that has slipped into the liquid receiving portion 8 or the frost melting water that has melted in the liquid receiving portion 8 flows through the drain pipe 9 into the evaporating dish 10. Drained (see FIG. 1). The water stored in the evaporating dish 10 is vaporized by, for example, heat generated by operating the compressor 21 or a fan disposed in the machine room, and is discharged outside the refrigerator.

  In addition, since the frost sliding down to the drain hole 30 has a small contact area with the tray 29, 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 heating amount of the drain hole 30 is increased, so that the drain hole 30 is blocked by the frost that slides down. 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 be disposed so as to pass over the drain hole 30.

  Moreover, by making the drain hole 30 have a mesh structure, it is possible to prevent unmelted frost from flowing into the drain pipe 9 and icing in the middle of the drain pipe 9.

  Further, the drain hole 30 is preferably formed in the vicinity of the arrangement position of the second thermistor 62. Thereby, when the frost sliding down to the drain hole 30 is completely melted, the frost attached to the tray 29 is completely melted, and the defrosting reliability can be improved.

FIG. 6 is a block diagram showing the configuration of the control system of the refrigerator showing the first embodiment of the present invention.
As shown in FIG. 6, the refrigerator in the present embodiment includes a control means 70 that controls the compressor 21, the internal fan 6, and the flow path switching valve 22 and can perform normal operation and defrosting operation. . A first thermistor 61 and a second thermistor 62 are connected to the control means 70.

Next, the temperature change of the cooler 25 and the tray 29 at the time of defrosting is demonstrated based on FIG.
FIG. 7 is a diagram showing temperature changes of the cooler and the tray during defrosting according to Embodiment 1 of the present invention.
FIG. 7 shows temperature changes of the cooler 25 and the tray 29 during defrosting according to the first embodiment.
In addition, the vertical axis | shaft of FIG. 7 shows the temperature of the cooler 25 detected by the 1st thermistor 61, and the temperature of the tray 29 detected by the 2nd thermistor 62, and a horizontal axis shows progress after a defrost start. Shows time.

This refrigerator performs normal operation continuously for a predetermined time. At this time, frost adheres to the tray 29 that functions as a sub-cooler during normal operation and the surface of the cooler 25 that functions as a cooler (evaporator) during normal operation.
After performing normal operation for a predetermined time (for example, about one day), the control means 70 switches to defrost connection and performs defrost operation.

As shown in FIG. 7, when defrosting is started, the temperature of the frost on the tray 29 and 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, although the frost on the cooler 25 and the surface of the cooler 25 also receives heat from the high-temperature refrigerant in the cooler 25 and rises to 0 ° C., the heat capacity of the cooler 25 is generally larger than the heat capacity of the tray 29. It becomes 0 degreeC later than 29 (A1).

When the temperature of the frost in the tray 29 and the tray 29 reaches 0 ° C., the heat of the refrigerant is used for melting the frost in the tray 29 (phase change from solid to liquid). It becomes constant at 0 ° C. until the frost 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).
When the frost melting of the cooler 25 proceeds to some extent, the frost slides from the cooler 25 onto the tray 29, and the temperature of the tray 29 rapidly decreases (B4, A2).

When the frost temperature of the tray 29 and the tray 29 becomes 0 ° C., the heat of the refrigerant is used for melting the frost of the tray 29 (phase change from solid to liquid), and the frost of the tray 29 is completely melted. Until this is done, the temperature of the tray 29 remains constant at 0 ° C. (B5).
When the frost sliding down on the tray 29 is completely melted, the temperature of the tray 29 rises again (B6).
Since no frost is present in the cooler 25 between B4 and B6, the temperature of the cooler 25 rises (A3).

Thus, the temperature of the tray 29 may repeat rising and lowering a plurality of times.
In the present embodiment, in order to prevent the frost from remaining on the tray 29, the temperature of the cooler 25 detected by the first thermistor 61 is equal to or higher than the set temperature, and is detected by the second thermistor 62 disposed immediately below. When the temperature of the tray 29 becomes equal to or higher than the set temperature, the defrosting operation is terminated.
Hereinafter, the details of the operation of the defrosting operation will be described with reference to FIG.

FIG. 8 is a flowchart of the defrost control showing the first embodiment of the present invention.
Hereinafter, control during the defrosting operation will be described based on each step of FIG. Note that STEP-a and STEP-b in FIG. 8 correspond to STEP-a and STEP-b in FIG.

When the normal operation is performed for a predetermined time (for example, about one day), the control means 70 starts the defrosting operation (S101).
When the defrosting operation is started, the control means 70 stops the operation of the internal fan (S102).
The control means 70 switches the flow path switching valve 22 to the defrost connection. 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 (S103).
The control means 70 fixes the rotation speed of the compressor 21 at the set rotation speed. Here, the rotation speed of the compressor 21 can be reduced to a high speed so that the discharge pressure of the compressor 21 does not exceed the specified pressure, so that the defrosting time can be shortened and the power consumption during defrosting can be reduced (S104). .

  The control means 70 detects the temperature of the cooler 25 from the first thermistor 61 (S105), detects the temperature of the tray 29 from the second thermistor 62 (S106), and the temperature of the cooler 25 and the temperature of the tray 29 are detected. And record.

Next, the control means 70 determines whether or not the temperature of the cooler 25 is equal to or higher than the set temperature (S107, STEP-a).
When the temperature of the cooler 25 is lower than the set temperature (S107; NO), the control means 70 returns to S105 and detects the temperature of the cooler 25 again.

On the other hand, when the temperature of the cooler 25 is equal to or higher than the set temperature (S107; YES), the control means 70 determines whether or not the temperature of the tray 29 is equal to or higher than the set temperature (S108, STEP-b). .
When the temperature of the tray 29 is lower than the set temperature (S108; NO), the control means 70 returns to S105 and detects the temperature of the cooler 25 again.

  On the other hand, when the temperature of the tray 29 is equal to or higher than the set temperature (S108; YES), the control means 70 switches the flow path switching valve 22 to the normal connection (S109) and releases the fixing of the compressor rotation speed (S110). ), The internal fan 6 is driven (S111), and the defrosting operation is terminated (S112).

As described above, in the present embodiment, the first thermistor 61 that detects the temperature of the cooler 25 is disposed in the cooler 25 at a position corresponding to the upstream side of the air passage and the return port. A second thermistor 62 for detecting the temperature was disposed directly below the first thermistor 61 in the tray 29. Then, the control means 70 determines the end of the defrosting operation based on the detection results of the first and second thermistors 62.
For this reason, it becomes possible to detect the temperature at the location where the frost amount of the cooler 25 is large and the position where the amount of frost sliding down to the tray 29 is large, and the defrosting operation is performed before the frost of the cooler 25 and the tray 29 is melted. It never ends. Therefore, frost can be prevented from remaining.
Moreover, since the end of the defrosting operation is determined based on the location where the frosting amount of the cooler 25 is large and the temperature at the position where the frost amount sliding down to the tray 29 is large, the time for the defrosting operation is longer than necessary. The power consumption during defrosting and pull-down can be reduced.

In the present embodiment, the first thermistor 61 is disposed upstream of the air passage in the cooler 25 and at a position where the amount of air flowing into the cooling chamber 7 from the return port is the largest. Yes.
For this reason, the 1st thermistor 61 will be arrange | positioned in the location where there is much frost formation among the coolers 25, the remaining of the frost of the cooler 25 can be prevented, and defrost reliability can be improved. .

In the present embodiment, the drain hole 30 is formed in the vicinity of the arrangement position of the second thermistor 62.
For this reason, when the frost sliding down to the drain hole 30 is completely melted, the frost attached to the tray 29 is completely melted, and the defrosting reliability can be improved.

Further, in the present embodiment, the drain hole 30 has a mesh structure that holds the frost that slides down on the tray 29.
For this reason, it is possible to prevent unmelted frost from flowing into the drain pipe 9 and freezing in the middle of the drain pipe 9.

Further, in the present embodiment, a plurality of storage chambers are provided, the air passages are respectively provided in the respective storage chambers, and the first thermistor 61 uses the air in the storage chamber having the highest set temperature zone among the plurality of storage chambers, It is disposed at a position corresponding to the return port that flows into the cooling chamber 7.
For this reason, the 1st thermistor 61 will be arrange | positioned in the location where there is much frost formation among the coolers 25, the remaining of the frost of the cooler 25 can be prevented, and defrost reliability can be improved. .
Also, in the refrigerator having a plurality of storage rooms, it is not necessary to provide the first thermistor 61 at the return port from each storage room, and the position corresponding to the return port of the storage room having the highest set temperature zone, Defrosting reliability can be ensured by arranging only one first thermistor 61.

Embodiment 2. FIG.
FIG. 9 is a diagram showing a cooling chamber of the refrigerator showing the second embodiment of the present invention.
10A and 10B are views showing a liquid receiving part of a refrigerator according to Embodiment 2 of the present invention, in which FIG. 10A is a top view and FIG. 10B is a side view.
9 and 10, the second thermistor 62 in the present embodiment is disposed directly below the first thermistor 61 and in the drain hole 30. In other words, the drain hole 30 is formed immediately below the first thermistor 61.
The drain hole 30 is arranged at a position where the position is lowest in the tray 29 and at a position directly below the first thermistor 61. As a result, the melted water of frost melted in the liquid receiving portion 8 flows through the drain pipe 9 and is drained to the evaporating dish 10.
Other configurations are the same as those in the first embodiment, and the same reference numerals are given to the same portions. Further, the control operation of the defrosting operation is the same as that of the first embodiment.

With this configuration, in the present embodiment, the arrangement location of the second thermistor 62 can be fixed, and variations in the arrangement location of the second thermistor 62 in the manufacturing process can be suppressed.
Also in the present embodiment, it becomes possible to detect the temperature of the portion where the amount of frost slipping from the cooler 25 is large, and when the frost at the portion where the second thermistor 62 is disposed is completely melted, The attached frost is completely melted, and the defrosting reliability can be improved.

  In addition, since the frost sliding down to the drain hole 30 has a small contact area with the tray 29, 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. 10, by arranging a part (II) of the tray pipe 28 in the vicinity of the drain hole 30 and increasing the amount of heating of the drain hole 30, the drain hole 30 is blocked by the frost that slides down. Can be prevented. For example, when the tray pipe 28 is provided on the upper surface of the tray 29, a part (II) of the tray pipe 28 may be disposed so as to pass over the drain hole 30.

Note that the amount of moisture that enters the cooling chamber 7 from the drain pipe 9 through the drain hole 30 due to the large diameter of the drain hole 30 or a large amount of frost melting water stored in the evaporating dish 10 is stored. In some cases, the amount of water entering from the room is greater.
In this case, as in the present embodiment, the drain hole 30 is directly below the first thermistor 61, that is, the first thermistor 61 is directly above the drain hole 30 and below the cooler 25 near the drain hole 30. By disposing, the first thermistor 61 is disposed at a location where the amount of frost that adheres to the cooler 25 is large due to moisture that has entered the cooling chamber 7 from the drain hole 30. It can prevent and defrost reliability can be improved.

  DESCRIPTION OF SYMBOLS 1 Refrigerating room, 2 Ice making room, 3 Multifunctional room, 4 Freezing room, 5 Vegetable room, 6 Inside fan, 7 Cooling room, 8 Liquid receiving part, 9 Drain pipe, 10 Evaporating dish, 21 Compressor, 22 Flow path Switching valve, 23 Condenser, 24 Capillary tube, 25 Cooler, 26 Header, 27 Bypass piping, 28 Tray piping, 29 Tray, 30 Drain hole, 41 Refrigerating chamber outlet, 42 Ice making chamber outlet, 43 Multifunctional chamber outlet , 44 Freezer compartment outlet, 45 Vegetable compartment outlet, 51 Refrigerator compartment return port, 54 Freezer compartment return port, 55 Vegetable room return port, 61 First thermistor, 62 Second thermistor, 70 Control means.

Claims (6)

A storage room for storing food,
A cooling chamber in which a cooler is arranged;
A blowout port through which air in the cooling chamber flows out to the storage chamber, and a return port through which air in the storage chamber flows into the cooling chamber, and an air passage for circulating the air in the storage chamber;
A tray that is disposed below the cooler and receives frost and water sliding down from the cooler;
First heating means for heating the cooler;
A second heating means for heating the tray;
A first temperature sensor provided in the cooler for detecting the temperature of the cooler;
A second temperature sensor provided on the tray for detecting the temperature of the tray;
Control means for determining the end of the defrosting operation by heating of the first and second heating means based on the detection results of the first and second temperature sensors;
The first temperature sensor is arranged at a position corresponding to the upstream side of the air passage and the return port in the cooler,
The refrigerator according to claim 2, wherein the second temperature sensor is disposed immediately below the first temperature sensor in the tray. 2. The refrigerator according to claim 1, wherein the first temperature sensor is disposed on the upstream side of the air passage and in the vicinity of the return port of the cooler. The first temperature sensor is disposed upstream of the air passage in the cooler and at a position where the amount of air flowing into the cooling chamber from the return port is the largest. The refrigerator according to claim 1 or 2. The tray has a drain hole for discharging water that has slipped from the cooler and water generated by melting of frost,
The refrigerator according to any one of claims 1 to 3, wherein the drain hole is formed in the vicinity of an arrangement position of the second temperature sensor. The refrigerator according to claim 4, wherein the drain hole has a mesh structure that holds frost that has slipped onto the tray. A plurality of the storage chambers;
The air passage is provided in each storage room,
The first temperature sensor is arranged at a position corresponding to a return port through which air in the storage chamber having the highest set temperature zone among the plurality of storage chambers flows into the cooling chamber. Item 6. The refrigerator according to any one of Items 1 to 5.

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