JP2011007435A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a refrigerator which avoids the heat of a heater used for defrosting to flow out into a freezing chamber or a refrigerating chamber, maintains defrosting quality, and suppresses electric power consumption.SOLUTION: The refrigerator includes: a cooler 24 which is part of a refrigerating cycle; a pipe heater 41 for directly melting frost adhered to the cooler 24; a radiant heater 15 arranged below the cooler 24 and melting frost from the lower side; and a control means (not shown in the figure) for controlling current-carrying to the pipe heater 41 and the radiant heater 15. The control means starts to energize the radiant heater 15 after starting to energize the pipe heater 41 so as to defrost the cooler 24.

Description

  The present invention relates to a refrigerator that defrosts frost adhered to a cooler using a heater.

  Some conventional defrosting devices for refrigerators use a glass tube heater and a pipe heater to melt frost attached to an evaporator (same as “cooler”). As an example, “a structure in which a glass tube heater 29 is disposed below the evaporator 13 and the pipe heater 41 is in direct contact with the fins 27 of the evaporator 13 and is made to continue substantially in parallel. The pipe heater 41 and the glass tube heater 29 are managed at the heater temperature set by the control unit 43 "(for example, see Patent Document 1). Defrosting without uneven heating can be performed by operating the pipe heater and the glass tube heater according to a place where the amount of frost formation is large or a place where the amount of frost formation is small.

JP 2000-121233 A (5th page, FIG. 10)

  In the conventional technology, as the control of the plurality of heaters, the degree of frost is determined based on the detection values of the plurality of frosting amount detection sensors, and the control is performed. However, it cannot be said that the generated heat is efficiently used for defrosting only with the actual amount of frost, and conversely, there is a problem that wasteful power consumption is consumed.

  Before the start of defrosting, the ambient temperature of the evaporator is very low and has dropped to around -24 ° C. When the glass tube heater and the pipe heater generate heat, due to the characteristics of both heaters, the periphery of the glass tube heater is instantaneously hot, whereas the periphery of the pipe heater, that is, the periphery of the fins, is instantaneously hot. It will not be. Therefore, since the area around the fins cannot be immediately defrosted, the fins are temporarily blocked with frost even after power is supplied. A large temperature difference occurs between the air suddenly warmed by the glass tube heater and the cool air of the evaporator, convection occurs, and the air warmed by the glass tube heater rises in convection. However, it is bounced back by the wall of the fin blocked by frost and returned to the bottom. The returned warm air flows through the freezer return air path and flows into the freezer and other refrigerators. As a result, there has been a problem that the temperature in the freezer compartment or the refrigerator is raised. This temperature increase can also damage food.

  The present invention has been made in order to solve such problems, and a refrigerator that prevents heat used for defrosting from flowing into the freezer compartment or the refrigerator, maintains defrost quality, and suppresses power consumption. The purpose is to obtain.

  In the refrigerator of the present invention, a compressor that compresses the refrigerant, a condenser that condenses the refrigerant, a throttle device that expands the condensed refrigerant, and a cooler that evaporates the expanded refrigerant are piped in an annular shape. Controls energization of the connected refrigeration cycle, a pipe heater disposed in contact with or near the cooler, a radiant heater disposed below the cooler, and the pipe heater and the radiant heater And a control means for energizing the pipe heater. After the partial defrosting starts, the control means starts energization of the radiant heater to defrost the cooler.

In the present invention, the control means first starts energization of the pipe heater in order to melt a part of the frost clogged between the fins of the cooler. Next, when the control means determines that the fin clogging has been partially eliminated, the control means starts energization of the radiant heater. The radiant heater radiates heat and melts the frost of the cooler and warms the surrounding air. The warmed air passes through the fins from which clogging has been eliminated and rises to the cooler. By reducing the air that has flowed back into the freezer or refrigerator due to clogging of the fins, the cooling efficiency in the freezer or refrigerator is improved, and the quality of food is maintained.
The refrigerator of the present invention has the effect of suppressing power consumption while defrosting the cooler, and further improving the quality of food.

It is a front view of the refrigerator which concerns on Embodiment 1 of this invention. It is sectional drawing of the refrigerator which concerns on Embodiment 1 of this invention. It is a sectional side view of the refrigerator room | chamber of the refrigerator which concerns on Embodiment 1 of this invention. It is a schematic explanatory drawing of the defrosting means of the refrigerator which concerns on Embodiment 1 of this invention. It is a flowchart of the defrost control using the cooler temperature sensor of the refrigerator which concerns on Embodiment 1 of this invention. It is a sectional side view which shows the cooler room of the refrigerator which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
FIG. 1 is a front view of a refrigerator according to Embodiment 1 of the present invention.
In FIG. 1, a refrigerator 11 includes a refrigerating room 12 at the top, an ice making room 3 and a switching room 4 arranged next to each other below the refrigerating room 12, and a freezing room 5 below the ice making room 3 and the switching room 4. The vegetable compartment 6 is provided under the freezer compartment 5. Of course, the presence / absence and position of each room does not limit the present embodiment. Further, the refrigerator 11 includes a refrigerator compartment door 7 and an ice compartment door 8 that can be freely opened and closed at respective openings of the refrigerator compartment 12, the ice making compartment 3, the switching compartment 4, the freezing compartment 5, and the vegetable compartment 6. , A switching room door 9, a freezing room door 10, and a vegetable room door 13. When each door is opened, food can be taken in and out.

FIG. 2 is a side sectional view of the refrigerator according to Embodiment 1 of the present invention.
In FIG. 2, the refrigerator 11 includes a cooling fan 32 and a refrigeration cycle 20 on the back surface. The cooling fan 32 is for blowing the cold air generated in the refrigeration cycle 20 to each room of the refrigerator 11.

  The refrigeration cycle 20 includes a compressor 21 that compresses refrigerant gas, a condenser 22 that condenses and liquefies the compressed refrigerant, a throttling device 23 that decompresses the liquefied refrigerant, and cooling that evaporates the decompressed refrigerant. The vessel 24 is pipe-connected in a ring shape. The cooler 24 is cooled by the heat absorption effect when the refrigerant evaporates inside.

Next, the cooler chamber in which the cooler 24 is housed will be described.
FIG. 3 is a side sectional view of the cooler chamber of the refrigerator according to Embodiment 1 of the present invention.
The pipe heater 41 is disposed in contact with or near the cooler 24, and below the cooler 24 and the wall surface of the freezer compartment 5, a freezer compartment return port 42 through which air flows from the freezer compartment 5 to the cooler 24. There is. In the lowermost part of the cooler chamber, there are a drain pan 33 for receiving drain water which is melted frost, and a drain hole 34 for discharging the drain water. A radiant heater 15 is disposed between the drain pan 33 and the cooler 24, and a heater cover 16 is disposed between the radiant heater 15 and the cooler 24. The heater cover 16 protects the drain water dripped from the cooler 24 from hitting the radiant heater 15.

  The pipe heater 41 is formed of a pipe portion forming an outer shell and a heater in the pipe. The pipe portion is preferably an aluminum tube from the viewpoint of cost and workability, and the internal heater is preferably a silicon-coated silicon heater from the viewpoint of heat resistance. However, the present invention is not limited to this.

FIG. 4 is a schematic explanatory diagram of the defrosting means for the refrigerator according to the first embodiment.
In FIG. 4, the control means 45 is connected to the motor 21 a and the expansion device 23 of the compressor 21, the pipe heater 41 for defrosting, the radiant heater 15, and the cooler temperature sensor 25. The control means 45 can control the pipe heater 41 and the radiant heater 15 independently from each other, based on the driving state of the motor 21a and the measured temperature of the cooler temperature sensor 25. Moreover, in this Embodiment, although the single heater is used for the pipe heater 41 and the radiant heater 15, respectively, you may install multiple each. However, as in the case of a single case, it is necessary to have a control means capable of separately controlling a plurality of heaters that are in contact with or installed near the cooler 24 and a plurality of heaters disposed below the cooler 24. is there.

The control means 45 starts defrosting control under certain conditions, such as when the accumulated operation time of the compressor 21 has passed a predetermined time. In addition, as the defrosting start condition, there is a case where the frosting amount exceeds a certain amount using the frosting amount detection sensor, but this embodiment does not limit the starting condition. When the defrosting is started, the control unit 45 first energizes the pipe heater 41. The pipe heater 41 directly heats the frost adhering to the cooler 24 and partially melts it. When it is determined that the frost adhering to the cooler 24 has been melted and air has flowed into the cooler 24, the control means 45 starts energizing the radiant heater 15.
The method for determining whether or not the gap is formed may be determined by using the frost amount detection sensor, starting after a certain period of time, or by the temperature of the cooler.

By heating only the pipe heater 41 in advance, first, the frost adhering to the cooler 24 can be partially slid down, and the clogging of the fins of the cooler 24 due to the frost is partially eliminated. , Voids are generated. Thereafter, the convection of heat generated by energizing the radiant heater 15 circulates from the formed gap portion to the cooler 24, so that defrosting can be performed efficiently. Of course, the radiant heater 15 also heats and defrosts frost radiation.
In the present embodiment, by controlling the heat of the radiant heater 15 to flow into the previously formed gap, the effect of reducing the heat flowing back into the freezer compartment 5 through the freezer return port 42 can be obtained. As a result, the temperature rise of the food in the freezer compartment 5 can be suppressed, and maintenance of food quality can be made relatively long.

FIG. 5 is a flowchart of defrosting control using the refrigerator temperature sensor of the refrigerator according to Embodiment 1 of the present invention.
The control means 45 is connected to a cooler temperature sensor 25 that measures the temperature of the cooler 24, and controls the pipe heater 41 and the radiant heater 15 according to the temperature of the cooler 24. FIG. 5 shows a defrosting control procedure (all steps).

  The control means 45 starts defrosting control under certain conditions of step S1. In step S2, energization of the pipe heater 41 is started, and the pipe heater 41 starts to generate heat. Due to this heat generation, frost adhering to the cooler 24 is partially melted and the cooler 24 is heated, and the temperature around the cooler 24 rises. In step S3, the control means 45 determines whether or not the measured temperature obtained from the cooler temperature sensor 25 has become equal to or higher than a predetermined temperature T1. The predetermined temperature T1 is desirably an arbitrary value in a range of approximately −13 ° C. or more and 0 ° C. or less. The control procedure returns to step S3 once when it is determined that the measured temperature is lower than the predetermined temperature T1 (N), and proceeds to step S4 when it is determined that the measured temperature is equal to or higher than the predetermined temperature T1 (Y). In step S4, energization of the radiant heater 15 is started, and the radiant heater 15 starts to generate heat. Due to this heat generation, the defrosting of the entire cooler 24 starts and the air around the radiant heater 15 is warmed. This air flows toward the cooler 24 and the temperature around the cooler 24 rises. In step S5, the control means 45 determines whether or not the measured temperature obtained from the cooler temperature sensor 25 has become equal to or higher than a predetermined temperature T2. The predetermined temperature T2 is equal to or higher than the predetermined temperature T1 and is approximately 5 ° C. The control procedure returns to step S5 once when it is determined (N) that the measured temperature is lower than the predetermined temperature T2, and proceeds to step S6 when it is determined (Y) that the measured temperature is equal to or higher than the predetermined temperature T2. In step S6, energization to the pipe heater 41 is terminated. Next, in step S7, the control means 45 determines whether or not the measured temperature obtained from the cooler temperature sensor is equal to or higher than a predetermined temperature T3. The predetermined temperature T3 is equal to or higher than the predetermined temperature T2 and is approximately 14 ° C. However, in practice, the predetermined temperature T3 is desirably set to an arbitrary temperature in the cooler 24 at which the defrosting of the cooler 24 is considered to be completed. In Step S7, the control procedure returns to Step S7 once again when the measured temperature is determined to be lower than the predetermined temperature T3 (N), and proceeds to Step S8 when it is determined that the measured temperature is equal to or higher than the predetermined temperature T3 (Y). . In step S8, energization of the radiant heater 15 is terminated, and in step S9, the defrost control is terminated.

  In step S3 of FIG. 4, the pipe heater 41 is energized until the cooler 24 reaches the predetermined temperature T1, whereby frost attached to the cooler 24 around the pipe heater 41 is melted. However, this melting is partial melting of the cooler 24 to which the pipe heater 41 is fixed, and does not lead to defrosting of the entire cooler 24. However, as the defrosting progresses partially, the temperature in the cooler 24 increases. When the temperature reaches a predetermined temperature T1, the radiant heater 15 is energized in step S5, and the entire cooler 24 is warmed from the bottom. It is done. The air suddenly warmed by the radiant heater 15 rises, passes through the partially melted space, and flows into the cooler 24. When there is no partial melting, the warmed air is repelled by frost clogged in the fins of the cooling air 24, flows backward through the freezer return port 42 and flows into the freezer 5, and the freezing efficiency of the freezer 5 Lower.

  In this embodiment, first, the pipe heater 41 partially melts the frost, then the cooler temperature sensor 25 determines the frost melting state, and the radiant heater 15 is used to delay the frost of the entire cooler 24 later. By melting, the cooler 24 can be efficiently defrosted without flowing heat into the freezer compartment 5.

  The reason for determining whether or not the measured temperature in the cooler 24 has become equal to or higher than the predetermined temperature T2 in step S5 is to avoid excessive heating of the cooler 24 by the pipe heater 41. When the pipe heater 41 finishes the defrosting in the vicinity, the pipe heater 41 starts to apply excess heat to the cooler 24 thereafter. The excessively applied heat becomes a load for the refrigeration control after the defrost control is completed, and decreases the refrigeration efficiency, that is, the power consumption efficiency. In order to avoid this decrease in refrigeration efficiency, the control means 45 ends energization of the pipe heater 41 in step S6.

Embodiment 2. FIG.
FIG. 6 is a side sectional view showing a cooler chamber of the refrigerator according to Embodiment 2 of the present invention.
In FIG. 6, the heater cover 16 </ b> A is inclined with respect to the horizontal plane so that the heat of the radiant heater 15 reaches the cooler 24 directly. Further, due to this inclination, the frost mass and drain water falling from the cooler 24 to the heater cover 16A during defrosting slides down from the heater cover 16A.

If the heater cover 16A is not inclined and the frost mass or drain water stays on the heater cover 16A, the heat of the radiant heater 15 is used to melt the frost on the heater cover 16A or to increase the temperature of the drain water. The defrosting effect of the cooler 24 is reduced.
In the present embodiment, the defrosting efficiency of the cooler 24 can be increased by inclining the heater cover 16A to remove frost masses and drain water from the heater cover 16A.
Although it is desirable that the inclination angle is 7 ° or more, regarding the sliding down of the frost mass and drain water, the heater cover 16A is formed of a material having good water repellency, so that the sliding down can be facilitated. The inclination angle is not limited to 7 ° or more.

The heater cover 16A needs to be large enough to cover the radiant heater 15 when the inclined heater cover 16A and the radiant heater 15 are projected in parallel from above. The heater cover 16A protects the frost mass and drain water falling from the cooler 24 during defrosting from directly falling on the radiant heater 15, and the frost mass and drain water touch the radiant heater 15 and evaporate. The boiling noise of the radiant heater 15 is suppressed, and the temperature drop of the radiant heater 15 due to evaporation is avoided.
In the present embodiment, it is possible to obtain an effect of suppressing noise and preventing efficiency deterioration by covering the frost and drain water falling from above with the heater cover 16 </ b> A so as not to hit the radiant heater 15.

  3 ice making room, 4 switching room, 5 freezing room, 6 vegetable room, 7 refrigeration room door, 8 ice making room door, 9 switching room door, 10 freezing room door, 11 refrigerator, 12 refrigeration room, 13 vegetable room door, 15 radiant Heater, 16 Heater cover, 16A Heater cover, 20 Refrigeration cycle, 21 Compressor, 22 Condenser, 23 Throttle device, 24 Cooler, 25 Cooler temperature sensor, 32 Cooling fan, 33 Drain pan, 34 Drain hole, 41 Pipe Heater, 42 Freezer return, 45 Control means.

Claims (3)

A refrigeration cycle in which a compressor that compresses a refrigerant, a condenser that condenses the refrigerant, a throttle device that expands the condensed refrigerant, and a cooler that evaporates the expanded refrigerant are connected to each other in a ring shape. When,
A pipe heater disposed in contact with or in the vicinity of the cooler;
A radiant heater disposed below the cooler;
Control means for controlling energization of the pipe heater and the radiant heater,
The said control means energizes the said pipe heater, and after partial defrosting starts, energization of the said radiant heater is started and the said cooler is defrosted. The refrigerator characterized by the above-mentioned. A cooler temperature sensor for measuring the temperature in the cooler;
The control means is
Energize the pipe heater,
After the measured temperature of the cooler temperature sensor reaches a predetermined temperature,
The refrigerator according to claim 1, wherein energization of the radiant heater is started. The refrigerator according to claim 1, further comprising a heater cover having an inclined surface between the radiant heater and the cooler.

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