JP6186187B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator.

Moisture in the air that has flowed into the refrigerator and moisture that has evaporated from the food is condensed by the cooler and then grows as frost. Since the frost grown on the cooler deteriorates the cooling performance, it is periodically unwound using a heating means such as an electric heater. Since the defrosting operation increases the heat load in the cabinet and deteriorates the energy saving performance, a control method for efficiently performing the defrosting is disclosed.
The timing of starting the defrosting operation of the household refrigerator is often performed, for example, when the cumulative operation time of the compressor reaches a predetermined value, and in addition, when the outside air temperature is high, the humidity is high. Since there are many conditions, the control which accelerates the start of a defrost operation is also performed. However, when the outside air temperature is high or the accumulated operation time of the compressor is long, there is a high possibility that more frost grows on the cooler, but the phenomenon associated with the amount of frost formation is not directly detected by the sensor. Therefore, efficient defrosting operation is not necessarily performed. In addition, since the amount of frost formation cannot be predicted, the heating temperature at the end of defrosting may be increased to satisfy the reliability so that the frost that has grown on the cooler does not melt regardless of the amount of frost. Many.

  Regarding the timing of starting the defrosting operation, for example, in the refrigerator described in Patent Document 1, a cooler temperature detecting means for detecting the temperature of the cooler, a cooler ambient temperature detecting means for detecting the ambient temperature of the cooler, and a cooling The defrosting timing is determined by predicting the frost formation amount of the cooler from both detection information of the cooler temperature detecting means and the cooler ambient temperature detecting means.

JP-A-10-227555

  In the refrigerator described in Patent Document 1, the frost detection sensor includes a cooler temperature detector and a cooler ambient temperature detector. Frost detection is performed using the temperature difference detected by these temperature detection units. If there is a lot of frost in the cooler ambient temperature detector, the cooler ambient temperature detector cannot contact the air around the cooler, and the temperature of the cooler ambient temperature detector is different from the temperature of the cooler temperature detector. Get smaller. On the other hand, if there is little frost in the cooler ambient temperature detection unit, the cooler ambient temperature detection unit can easily come into contact with the air around the cooler, so the temperature of the cooler ambient temperature detection unit is the temperature of the cooler temperature detection unit. And the difference becomes larger. Because frost detection is performed using these principles, frost detection is not performed because there is no difference between the temperature of the cooler ambient temperature detector and the temperature of the cooler temperature detector while the compressor is stopped. However, frost detection is performed during compressor operation.

  However, since the rotation speed of the compressor changes depending on the usage situation of the refrigerator, if the compressor rotation speed increases, the cooler temperature decreases, and if more frost grows between the fins of the cooler, the cooler is turned off. Since the amount of heat exchanged with the passing air is reduced, the cooler temperature may be lowered without increasing the rotational speed of the compressor. Thus, the temperature detected by the cooler temperature detection unit during operation of the compressor is simultaneously affected by the cooling temperature due to the start of the compressor and the amount of frost in the cooler. The change in the ambient temperature of the cooler and the change in the cooler temperature may not always be linked.

  Therefore, the accuracy of frost detection based on the difference between the temperature of the cooler ambient temperature detection unit and the temperature of the cooler temperature detection unit is not necessarily good. In addition, the installation location of the cooler ambient temperature detection unit is not particularly mentioned, and the heating method according to the amount of frost formation is not described.

  The present invention has been made in view of the problems as described above, and predicts the amount of frost formation before carrying out the defrosting operation, and reduces the amount of power consumed for heater heating during defrosting. An object is to provide a refrigerator with excellent energy saving performance.

In order to solve the above problems, for example, the configuration described in the scope of the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems. For example, a cool air supply means for supplying cold air to a storage room in a refrigerated temperature zone, and a cooler for cooling the storage room in the refrigeration temperature zone. A refrigeration cycle configured by connecting the cooler, the compressor, the radiator, and the throttle with a refrigerant pipe, temperature detection means provided in a part of the refrigerant pipe of the cooler, and cold air from the storage chamber In the refrigerator including a storage room cold air return duct that flows into the cooler, a defrost heater that heats the cooler, and a duct heater that heats the storage room cold air return duct , the cold air supply after the compressor is stopped after circulated for a predetermined time cold air by means based on the temperature before the supply of the defrosting heater and the Dakutohita detected by said temperature detecting means, said Dakutohita the defrost heater is energized energized Whether to no control, the defrost heater and whether to control for energizing both the Dakutohita, and determining the.

  According to the present invention, since the amount of frost formation can be predicted before the defrosting operation is performed, the amount of electric power consumed for heating the heater during the defrosting is reduced, and a refrigerator excellent in energy saving is provided. It becomes possible to do.

It is a front view of the refrigerator which concerns on embodiment of this invention. It is AA sectional drawing of the refrigerator which concerns on this invention. It is the figure which looked at the peripheral part of the cooler 7 from the front, and is a flow of the cold air at the time of cooling-room cooling. It is the figure which looked at the peripheral part of the cooler 7 from the front, and is a flow of the cold air at the time of freezing room cooling. 2 is a cross-sectional view of the cooler 7 along BB. It is the temperature chart and operation | movement of each part in cooling operation. It is the schematic of the cooler 7 when there is little frost which grew on the cooler 7. FIG. It is the schematic of the cooler 7 when there is much frost which grew in the cooler 7. FIG. It is the relationship between the temperatures T1 and T2 during the frost detection operation with respect to the frost amount G. It is the temperature increase rate during the frost detection operation with respect to the frost amount G. It is the relationship between temperature T2 with respect to the amount of frost formation G, and freezer compartment temperature. It is the relationship between temperature T2 with respect to the amount of frost formation G, and an internal fan input value. It is an example of the heater heating control at the time of defrosting when there is little frost. It is an example of the heater heating control at the time of defrosting when there is much frost. It is another Example of the heater heating control at the time of defrosting when there is much frost. Frost distribution when there is little frost and the flow of cold air returning to the refrigerator compartment The figure which looked at the section of freezer room 5 when there is little frost from the top Frost distribution when there is a lot of frost and the flow of cold air returning to the refrigerator compartment The figure which looked at the section of freezer compartment 5 when there is much frost from the top It is the sensor temperature of each part at the time of the frost detection operation with respect to the frost amount G.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an external view of a refrigerator according to an embodiment of the present invention. As shown in FIG. 1, the refrigerator 1 of this embodiment is comprised from the upper part from the refrigerator compartment 2, the ice making room 3, the upper stage freezer room 4, the lower stage freezer room 5, and the vegetable compartment 6. As shown in FIG. The refrigerating room 2 includes left and right refrigerating room doors 2a and 2b. The ice making room 3, the upper freezing room 4, the lower freezing room 5, and the vegetable room 6 are a pull-out ice making room door 3a and an upper freezing room door, respectively. 4a, a lower freezer compartment door 5a, and a vegetable compartment door 6a. Hereinafter, the refrigerator compartment doors 2a and 2b, the ice making compartment door 3a, the upper freezer compartment door 4a, the lower freezer compartment door 5a, and the vegetable compartment door 6a are simply referred to as doors 2a, 2b, 3a, 4a, 5a, and 6a. A door hinge for fixing the refrigerator 1 and the doors 2 a and 2 b is provided at the upper part of the refrigerator, and the door hinge is covered with a door hinge cover 53.

  FIG. 2 is a cross-sectional view taken along the line AA of the refrigerator according to the present invention. The outside of the refrigerator 1 and the inside of the refrigerator are separated by a heat insulating box 10 formed by filling a foam heat insulating material. A plurality of vacuum heat insulating materials 25 are mounted on the heat insulating box 10 of the refrigerator 1. The refrigerating compartment 2 is separated from the upper freezing compartment 4 and the ice making compartment 3 by the heat insulating partition wall 28, and the lower freezing compartment 5 and the vegetable compartment 6 are similarly separated by the heat insulating partition wall 29. A plurality of door pockets are provided on the inner side of the doors 2a, 2b in the order of 33a, 33b, 33c from the top, and the refrigerator compartment 2 is partitioned into a plurality of storage spaces by a plurality of shelves 34. In the lower part of the refrigerator compartment 2, a reduced pressure storage chamber 35 for storing food by reducing the pressure is provided. In order to reduce the pressure inside the decompression storage chamber 35, a decompression pump (not shown) is provided, and in order to maintain the internal pressure, a door is provided in the decompression storage chamber so that it can be locked with a handle. It has become.

  Between the upper freezer compartment 4 and the lower freezer compartment 5, the heat insulation partition wall 40 of the freezer compartment is provided. In the upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6, storage containers 3b, 4b, 5b, 6b are provided integrally with doors 3a, 4a, 5a, 6a provided in front of the respective cooling compartments. The storage containers 4b, 5b, 6b can also be pulled out by pulling out the doors 4a, 5a, 6a to the front side. The ice making chamber 3 is also provided with a storage container integrally with the door 3a, and the storage container 3b can also be pulled out by pulling the door 3a forward. Moreover, the outside temperature sensor 52 is provided, for example, inside the door hinge cover 53 of the refrigerator 1.

  The cooler 7 is provided in a cooler storage chamber 8 provided substantially at the back of the lower freezing chamber 5, and heat is exchanged with the cooler 7 by an internal fan 9 (cold air supply means) provided above the cooler 7. The chilled air passes through the refrigeration chamber 2, the upper freezer compartment 4, the lower freezer compartment duct 12, the lower freezer compartment air duct 13, and the ice making compartment air duct (not shown). It is sent to each storage room of the ice making room 3.

  Cooling air blowing to each storage room is controlled by opening / closing of the cold air blowing adjusting means, that is, the refrigerator compartment damper 20 and the freezer compartment damper 60. The refrigerator compartment damper 20 and the freezer compartment damper 60 adjust the air volume by opening and closing the baffles provided at the openings of the respective dampers by a motor drive unit (not shown).

  In the case of the refrigerating room cooling operation for cooling the refrigerating room 2, the refrigerating room 20 is opened, the freezing room damper 60 is closed, and cold air is sent from the outlet (not shown) to the refrigerating room 2 through the refrigerating room duct 11. . After circulating cold air to the refrigerator compartment 2, the cold air flows into the refrigerator compartment cold air return port 54 (see FIG. 3) provided at the lower part of the refrigerator compartment, and then returned from the right side of the cooler 7.

  There are various methods for cooling the vegetable compartment 6, for example, a method of directly sending cold air to the vegetable compartment 6 after cooling the refrigerator compartment 2, or cold air generated by the cooler 7 using a damper dedicated to the vegetable compartment Can be considered as a method of directly sending to the vegetable compartment 6. In the present application, any method may be used for supplying cold air to the vegetable compartment 6. In the example shown in FIG. 2, the cold air that has flowed into the vegetable compartment 6 flows from the vegetable compartment cold air return port 18 a provided in front of the lower part of the heat insulating partition wall 29 to the vegetable compartment return discharge port 18 b via the vegetable compartment return duct 18. To the cooler 7.

  In the case of the freezing room cooling operation for cooling the freezing rooms 4 and 5 (including the ice making room 3 but omitted below), the refrigerating room damper 20 is closed and the freezing room damper 60 is opened, and the cold air is in the upper freezing room 4 and the lower stage. After the freezing room 5 and the ice making room 3 are cooled, they are returned to the cooler 7 through the freezing room cold air return port 17. There is also an operation of cooling the refrigerator compartment 2 and the freezer compartments 4 and 5 at the same time depending on the temperature in the refrigerator. In this case, both the refrigerator compartment damper 20 and the freezer compartment damper 60 are opened to cool each storage compartment. Blow. The ventilation of the refrigerator compartment 2 and the freezer compartments 4 and 5 is detected by a temperature sensor 42 that detects the internal temperature of the refrigerator compartment 2 and a temperature sensor 43 that detects the internal temperature of the freezer compartments 3 and 4. The opening / closing control of the baffles of the refrigerator compartment damper 20 and the freezer compartment damper 60 is performed according to the temperature to be performed.

  A defrost heater 22, which is an example of a heating unit, is provided below the cooler 7. The drain water generated at the time of defrosting once falls into the tub 23 and is discharged through the drain hole 27 to the evaporating dish 21 provided at the upper part of the compressor 24. In addition to the compressor 24, a radiator and a heat radiating fan (not shown) are arranged in the machine room 58 provided at the lower back of the refrigerator.

  A control board 51 equipped with a memory and an interface circuit is disposed on the upper surface of the ceiling wall of the refrigerator 1, and a cooling operation, a defrosting operation, and the like are performed according to the control contents stored in the control board 51. The control board 51 is covered with a board cover 50.

  FIG. 3 is a view of the periphery of the cooler 7 as viewed from the front, and shows the flow of cold air during cooling in the refrigerator compartment. The refrigerating room return air 57 passes through the refrigerating room cold air return duct 54 provided on the side of the cooler 7, and the direction of flow is changed by about 90 degrees by the bent portion 61 provided at the front end of the refrigerating room cold air return duct 54. Instead, it flows from the lower right side of the cooler 7 when viewed from the front. Thereafter, the flow direction is changed again by about 90 degrees, and the flow flows toward the upper part of the cooler 7. The defrost heater 22 for defrosting the frost grown in the cooler 7 and the cooler storage chamber 8 in the periphery of the cooler 7, and the frost grown on the surface of the refrigerating room cold air return duct 54 on the surface of the refrigerating room cold air return duct 54 Duct heaters 55 for solving the above are provided. The cold air flow shown in FIG. 3 is used when the compressor 24 is operated to cool the refrigerator compartment 2 (hereinafter referred to as “R operation”), and the compressor 24 is stopped and the internal fan 9 is operated. It corresponds to the case of cooling (frost cooling) using the frost of the cooler 2. When the refrigerator compartment 2 is cooled regardless of the operation of the compressor 24, the flow of cold air shown in FIG. Further, a temperature detection means 56 is provided on the refrigerant pipe connected to the cooler 7 at the upper part of the cooler 7, and mainly detects the temperature of the cooler 7.

  FIG. 4A is a view of the periphery of the cooler 7 as viewed from the front, and shows the flow of cold air during cooling of the freezer compartment. FIG. 4 b is a cross-sectional view of the cooler 7 taken along the line BB. When the compressor 24 is operated to cool the freezer compartments 4 and 5 (hereinafter referred to as “F operation”), the freezer return to the freezer compartment 17 (see FIG. 2) provided on the front side of the cooler 7 is performed. Cold air 63 flows in. Accordingly, during the F operation, the freezer return cold air 63 flows from the lower front part of the cooler 7, and then the cool air flows toward the upper part of the cooler 7 by changing the direction by about 90 degrees. Further, when the refrigerator compartment 2 and the freezer compartments 4 and 5 are cooled at the same time, the flow of the cold air shown in FIGS. 3 and 4a is generated at the same time.

  FIG. 5 is a temperature chart during the cooling operation and the operation of each part. In the cooling operation of the refrigerator 1, the compressor 24 is operated, the refrigerator compartment damper 20 (hereinafter sometimes referred to as “R damper 20”) is opened, and the freezer compartment damper 60 (hereinafter referred to as “F damper 60”). Is closed and the refrigerator 2 is cooled, the R damper is closed, the F damper is opened, the F damper is opened and the refrigerators 4 and 5 are cooled, the compressor 24 is stopped, and the R damper is opened. The order of the frost cooling operation in which the F damper is closed and the refrigerator compartment 2 is cooled is one cycle, and when the fluctuation of the heat load in the warehouse is small, these are repeated and stable cooling is continued.

  The control during each cooling operation will be briefly described. When the temperature sensor 43 that detects the temperature of the freezer compartments 3 and 4 reaches the TFC, the compressor 24 is started. The cooling operation is performed from the R operation until one of the conditions is satisfied until the lower limit value TRMin of the refrigerator compartment temperature sensor 42 or the upper limit value TFMax of the freezer compartment temperature sensor 43 is reached. Thereafter, the F operation is performed until the lower limit value TFMin of the freezer temperature sensor 43 is reached. In frost cooling, the R damper 20 is opened while the compressor is stopped, the F damper 60 is closed, and the refrigeration chamber 2 is cooled by using the cold energy of the frost grown on the cooler 7.

  Since the temperature sensor 56 is provided so as to be in contact with the refrigerant pipe connected to the upper part of the cooler 7, when the compressor 24 is in operation, it is strongly influenced by the temperature of the refrigerant flowing through the pipe of the cooler 7. On the other hand, at the end of the F operation, that is, when the compressor 24 is stopped and the frost cooling is started, the temperature of the refrigerator compartment 2 is approximately the same every time unless the set temperature in the refrigerator is changed. The temperature of the refrigeration chamber return cold air 57 that flows into the refrigeration chamber 7 is also the same every time. Similarly, the temperature of the freezer compartments 3 and 4 is also cooled until the same temperature TFMin is reached every time unless the set temperature is changed, so the temperatures of the freezer compartments 3 and 4 when the F operation ends are also the same. become. Therefore, the temperature detected by the temperature sensor 56 is less affected by the refrigerant temperature of the cooler 7 when the compressor 24 is stopped, and the temperature change of the cooler 7 due to the cool air flowing into the cooler 7 can be easily measured. Become. In addition, an on-off valve is provided in the middle of the pipe connecting the radiator and the cooler constituting the refrigeration cycle of the refrigerator 1 so that the refrigerant flowing from the high-pressure side radiator to the low-pressure side cooler temporarily when the compressor is stopped. If the temperature sensor 56 detects the temperature change due to the influence of the cold air flowing into the cooler 7 while suppressing the temperature rise of the cooler 7 due to the refrigerant, the accuracy of detecting the amount of frost formation can be further improved. For the reasons as described above, the frosting amount detection operation is simultaneously performed while frost cooling is performed while the compressor 24 is stopped.

  The number of rotations of the internal fan 9 during frost cooling does not change greatly, and the temperature of the cold room return cold air flowing into the cooler 7 is also substantially constant. Therefore, when the frost cooling starts, that is, the frost amount detection operation starts. The temperature of the temperature sensor 56 at the time becomes a substantially constant temperature T1. The temperature sensor 56 can detect the temperature of the cooler 7 after exchanging heat with the refrigerated room return air 57 and the frost grown on the cooler 7. The temperature sensor 56 rises in temperature under the influence of the frost formation amount (heat storage amount due to frost) of the cooler 7 and the air volume (heating by cold air) of the cold room return cold air 57 passing through the cooler 7 (frost layer). Therefore, the temperature T2 is reached after Δt. When the frost formation amount detection operation is performed, the temperature T2 reached by the temperature sensor 56 differs depending on the detection operation time. Therefore, when the frost formation amount detection operation is performed, the operation time Δt is determined in advance.

  6 is a schematic diagram of the cooler 7 when there is little frost grown on the cooler 7, and FIG. 7 is a schematic view of the cooler 7 when there is much frost grown on the cooler 7, respectively.

  The main cause of the frost growing on the cooler 7 is largely due to the cold room return cold air 57 flowing from the cold room cold air return duct 54. Since the refrigeration chamber cold air return duct 54 is a curved flow path, when the refrigeration chamber return cold air 57 flows from the lower part of the cooler 7, the flow is biased to the outside with a large bending radius. Therefore, the frost that grows in the cooler 7 begins to grow from the cooler 7 on the opposite side to the cold room cool air return duct 54 (left side as viewed from the front of the refrigerator 1), and gradually, the cold room cool air return duct 54 side. It is known to grow towards. When there is little frost (refer FIG. 6), the frost which grows to the cooler 7 becomes distribution with much frost on the left side seeing from the front, and few frost toward the right side. On the other hand, when there is a lot of frost (see FIG. 7), the frost that grows on the cooler 7 as a whole is large, but the left side of the cooler 7 that starts to frost tends to increase.

  Since the temperature of the refrigeration chamber return cold air 57 at the start of the frost amount detection operation performed for each cycle is substantially the same, the temperature provided by contacting the refrigerant pipe connected to the cooler 7 by stopping the compressor 24 The sensor 56 can measure the temperature change of the cooler 7 after being simultaneously affected by the amount of frost formation and the air volume of the inflowing cold room return cold air 57. Since the cold air 57 returning from the refrigerator compartment exchanges heat with frost when passing through the cooler 7, the temperature of the cooler 7 rises together with the frost layer adhering to the cooler 7. If the amount of heat transferred from the cooler 57 or the frost layer that has grown into the cooler returns from the refrigerator compartment 57 is the same, the amount of heat stored by the frost is greater when the amount of frost is larger. The temperature rise is suppressed, and the temperature T2 at the end of the frost amount detection operation is lowered. On the other hand, the resistance to ventilation gradually increases due to the frost grown on the cooler 7, and as a result, the air volume of the cold air 57 returning to the refrigerator compartment decreases, and the amount of heat transferred from the cold air 57 returning to the cooler 7 or the frost layer. Therefore, the temperature rise of the temperature sensor 56 is suppressed. In actuality, both of these influences cause an increase in the amount of heat stored by the frost as the frost increases, and the amount of air in the refrigeration room return cold air 57 decreases, so the amount of heat transferred to the cooler 7 or frost layer decreases. Therefore, the rise in temperature T2 at the end of the frost amount detection operation is suppressed and becomes low.

  The phenomenon described above is utilized in the frost formation amount detection operation according to the present invention. When the frost grown on the cooler 7 is small, the temperature detected by the temperature sensor 56 is likely to rise, and when there is a lot of frost, the temperature is detected. Since the rise in temperature detected by the sensor 56 is suppressed, the temperature at the end of the frosting amount detection operation is lowered. In addition, the place where the frost is generated may be the cooler 7 and its surroundings and the inside of the refrigeration room cold air return duct 54, but the location of the temperature change of the temperature sensor 56 is caused by the frost formation. It cannot be distinguished. If the amount of frost that has grown in the refrigerator compartment cool air return duct 54 increases, the ventilation resistance also increases when passing through the refrigerator compartment cool air return duct 54, so the temperature detected by the temperature sensor 56 even when the refrigerator 7 has little frost, Lower.

  Next, the relationship between the temperature detected by the temperature sensor 56 and the frost amount during the frost amount detection operation will be described.

  FIG. 8a shows the relationship between the temperatures T1 and T2 during the frost detection operation with respect to the frost amount G. As described above, the temperature detected by the temperature sensor 56 at the start of the frost detection operation is substantially constant and becomes T1 (for example, T1 = −28 ° C.). During the frosting detection operation (during frost cooling), the temperature of the cooler 7 gradually rises due to heating by the refrigerating room return cold air 57, and the temperature detected by the temperature sensor 56 after time Δt is T2. It has been confirmed by experiments that the temperature T2 decreases as the cooling time elapses. That is, as shown in the temperature chart of FIG. 5, the line 83 connecting the temperature T2 at the end of the frost detection operation linearly decreases with the elapse of the cooling time. Therefore, as shown in FIG. 8a, the temperature T1 detected by the temperature sensor 56 at the start of the frost formation amount detection operation is substantially constant regardless of the frost formation amount. The temperature T2 after the time Δt decreases linearly with the cooling time, that is, with the increase in the amount of frost formation. Therefore, if the temperature change detected by the temperature sensor 56 with respect to the amount of frost formation is stored in advance, the frost Even if the amount is not measured, if the temperature is detected by the temperature sensor 56, the amount of frost formation can be predicted before defrosting.

  FIG. 8 b is a temperature increase rate during the frost detection operation with respect to the frost amount G. The temperature increase rate (slope) A is an average temperature increase rate during the frost amount detection operation, which is obtained from the difference between the detection temperature T1 of the temperature sensor 56 at the start of the frost detection operation and the temperature T2 after Δt. . As shown in the temperature chart of FIG. 5, the temperature increase rate A is the same as the detected temperature T1 of the temperature sensor 56, but the T2 is lower as the amount of frost formation increases. The temperature rise rate of becomes smaller.

  FIG. 8c shows the relationship between the temperature T2 and the freezer compartment temperature with respect to the frost amount G. At the end of the frosting amount detection operation, that is, when the compressor 24 is started when the temperature detected by the freezer temperature sensor 43 reaches TFC (see FIG. 5), it is represented by the freezer temperature sensor 43. The temperatures of the freezing rooms 4 and 5 are also substantially constant regardless of the amount of frost formation (for example, the temperature of the freezing room temperature sensor 43 is −22 ° C.). A relationship similar to that in FIG. 8 a is also observed between the temperature T 2 detected by the temperature sensor 56 and the temperatures of the freezing rooms 4 and 5 represented by the freezing room temperature sensor 43.

  FIG. 8d shows the relationship between the temperature T2 and the input command value of the internal fan 9 with respect to the frost amount G. The temperature T2 detected by the temperature sensor 56 changes in relation to the amount of frost formation. Since the ventilation resistance increases with the increase in the amount of frost formation, the command voltage of the internal fan 9 increases in order to maintain a predetermined rotational speed. If the relationship between the amount of frost formation and the command voltage of the internal fan 9 is measured in advance, the amount of frost formation can be predicted together with the detection of the amount of frost formation by the temperature T2 detected by the temperature sensor 56. The prediction accuracy can be increased.

  Next, heater heating control during defrosting will be described.

  FIG. 9 is an example of heater heating control during defrosting when there is little frost. The compressor integrated time for performing the defrosting start determination determined in advance according to the outside air temperature is ts. The temperature (T2) G detected by the temperature sensor 56 at the end of the frosting amount detection operation performed at the nearest time with respect to the time reaching the integrated time ts is set to a predetermined threshold temperature (T2) Gt. By comparing with (frosting amount Gt), heater heating control at the time of defrosting is determined. The threshold temperature (T2) Gt is a temperature determined in advance by experiment. The threshold temperature (T2) Gt is determined based on the frosting state of the cooler 7 and its surroundings and the frosting state of the cold room return air duct 54. The decision was made in consideration of the fact that no frost thaw occurred. Although the threshold temperature (T2) Gt varies depending on the refrigerator, for example, when the temperature T2 when the frost formation amount Gt = 250 g is set as the threshold temperature, (T2) Gt = −16 ° C. By comparing the threshold temperature (T2) Gt with the temperature (T2) G at the end of the frost amount detection operation, the heater heating control according to the frost amount is performed.

  At the time of defrosting, the defrosting heater 22 provided at the lower part of the cooler 7 and the duct heater 55 are used as main heating sources. However, when the amount of frost formation is large, the frost that has grown on the periphery of the cooler 7 is also released. For the purpose, the defrosting end determination temperature may continue to be heated by the defrosting heater 22 and the duct heater 55 until the temperature detected by the temperature sensor 56 reaches, for example, about 10 ° C. Since the amount of frost formation can be predicted before the start of defrosting by the frost amount detection operation, heater heating control according to the amount of frost formation can be performed.

When the temperature (T2) G at the end of the frost amount detection operation performed at the closest time reaching the integrated time ts is higher than the threshold temperature (T2) Gt, that is, the frost amount at the start of defrosting. Consider the case of few. As a specific example, for example, a case where the temperature at the end of the frost amount detection operation (T2) G = −14 ° C. (frost amount G = 100 g) and the threshold temperature (T2) Gt = −16 ° C. is considered. . When there is a lot of frost, a case where a lot of frost grows in the peripheral part other than the cooler 7 can be considered, but when there is little frost in the cooler 7, a little frost grows in the peripheral part other than the cooler 7. Therefore, heating to a state that greatly exceeds the melting point of 0 ° C. merely raises the temperature of the cooler 7.
In such a case, in addition to the increase in the power consumption of the heater, the amount of heat applied to the interior by the heater during defrosting also increases, so the power consumption during cooling increases, which is a factor that deteriorates energy saving performance. Become. Therefore, detection of the amount of frost formation before defrosting is important in determining heater heating control during defrosting.

  In the refrigerator 1 according to the present embodiment, the internal fan 9 is operated while the defrost heater 22 is energized, and the cold air circulating in the refrigerator compartment 2 can be used as a heating source at the time of defrosting (R damper 20 open, F damper 60 Closed). Therefore, when the heating amount required at the time of defrosting is made constant, the energy consumed by the defrosting heater 22 is reduced by the heating amount by the cold air circulating in the refrigerator compartment 2, and the energy saving performance is improved. Moreover, since the internal fan 9 is operated, cold air is generated by frost, and the temperature of the refrigerator compartment 2 can be lowered. Accordingly, the internal fan 9 is operated until the temperature detected by the temperature sensor 56 reaches, for example, about 3 ° C. (time t2) from the start of defrosting (time t1), and the defrosting heater 22 is energized and heated. At this time, the R damper 20 is open and the F damper 60 is closed. Further, the duct heater 55 is not energized.

  FIG. 10 is an example of heater heating control during defrosting when there is a lot of frost. Consider the case where the temperature (T2) G detected by the temperature sensor 56 is lower than the threshold temperature (T2) Gt, that is, when the amount of frost formation at the start of defrosting is large, in the same way as when there is little frost. . As a specific example, for example, consider a case where the temperature at the end of the frost amount detection operation (T2) G = −18 ° C. (frost amount G = 400 g) and the threshold temperature (T2) Gt = −16 ° C. . It is necessary to consider the case where frost grows in the cooler peripheral part other than the cooler 7 and also in the refrigerator compartment cold air return duct 54. The defrost heater 22 and the duct heater 55 are energized, and the internal fan 9 is operated until the temperature detected by the temperature sensor 56 reaches, for example, about 3 ° C. (time t2) (R damper 20 is open and F damper 60 is closed). Thereafter, the operation of the internal fan 9 is stopped, the defrost heater 22 and the duct heater 55 are continuously energized, and the temperature detected by the temperature sensor 56 is heated to, for example, about 10 ° C. (time t3). Between the time t2 and the time t3, the R damper 20 is closed and the F damper 60 is opened to promote natural convection generated by heating with the defrost heater 22 and quickly raise the temperature above the cooler 7. I am doing so.

  FIG. 11 shows another embodiment of heater heating control during defrosting when there is a lot of frost. The heater heating control when the temperature (T2) G detected by the temperature sensor 56 is lower than the threshold temperature (T2) Gt, that is, when it is determined that the amount of frost formation is large is as described in FIG. However, the heating control in which the amount of heating by the duct heater 55 is suppressed to further improve energy saving will be described.

  The reason why the detection temperature (T2) G of the temperature sensor 56 during the frosting amount detection operation is lower than the threshold temperature (T2) Gt is not necessarily the frost that has grown in the cooler 7 and the cold room return air duct 54. In many cases, the detected temperature (T2) G is actually lowered by the frost that has grown on the cooler 7, not by the frost that has grown on the cooler 7. Therefore, first, the defrost heater 22 is energized, and the internal fan 9 is operated until the temperature detected by the temperature sensor 56 reaches, for example, about 3 ° C. (time t2) (the R damper 20 is opened and the F damper 60 is opened). Then, the operation of the internal fan 9 is stopped, the defrost heater 22 is energized continuously, and heated until the temperature detected by the temperature sensor 56 becomes, for example, about 10 ° C. (time t3). Between the time t2 and the time t3, the R damper 20 is closed and the F damper 60 is opened to promote the natural convection generated by heating with the defrost heater 22 so as to increase the temperature above the cooler 7 quickly. I have to.

  After the defrosting is completed, the compressor 24 is operated, and after reaching a predetermined internal temperature (time t4), the frosting amount detection operation is performed when the compressor is stopped for the first time. Since the defrosting operation is completed and the frosting amount detection operation is performed when the compressor is stopped for the first time, the amount of frost that grows in the cooler 7 is usually small. Therefore, the detected temperature (T2) G after Δt is lower than the threshold value (T2) Gt ′ (for example, (T2) Gt ′ = − 12 ° C.) when the cooler 7 has almost no frost. At that time, it is determined that the frost has grown on the cold air return duct 54, and the duct heater 55 is energized from time t5 when the frost amount detection operation ends. For example, when the temperature detected by the temperature sensor 56 reaches about 3 ° C. (time t6), the duct heater 55 is deenergized. At this time, the internal fan 9 is operated, and the refrigeration chamber 2 may be cooled by the frost that has grown in the refrigeration chamber cold air return return duct 54, and the refrigeration chamber return cold air 57 can be used as a heating source. Can reduce the amount of power consumed. On the other hand, when the detected temperature (T2) G after Δt is higher than the threshold value (T2) Gt ′ when the chiller 7 has almost no frost, the refrigeration chamber cold air return duct 54 has no frost. As a result, the duct heater 55 is not energized.

  As described above, the amount of frost formation is predicted by comparing with a predetermined threshold temperature (T2) Gt based on the temperature (T2) G detected by the temperature sensor 56 during the frost amount detection operation, and defrosting is performed. The control for determining the heating means at the time has been described. Further, as shown in FIG. 8a, the heating means at the time of defrosting can be similarly determined by comparing the temperature difference between the threshold values (T2) Gt and T1 and the temperature difference between (T2) G and T1. it can. Similarly, the heating means at the time of defrosting can be determined by comparing the temperature increase rate (A) G with the threshold value (A) G of the temperature increase rate A shown in FIG. 8b. In FIG. 8c, the F room temperature (temperature sensor 43) at the start of the frost amount detection operation is constant at the start of the frost amount detection operation. Accordingly, since the F room temperature detected by the temperature sensor 43 can be used instead of the temperature T1 detected by the temperature sensor 56, the threshold temperature (T2) Gt and the F room temperature (temperature sensor 43) can be used. Even if the difference is used, the amount of frost formation can be similarly predicted. Further, FIG. 8 d shows the relationship between the command voltage of the internal fan 9 and the temperature T 2 detected by the temperature sensor 56. Similarly to the threshold value (T2) G determined by the temperature detected by the temperature sensor 56, the amount of frost formation is also predicted by providing a threshold value for the command voltage of the internal fan 9 together. Therefore, the prediction accuracy is increased.

  Next, an embodiment in which the frost detection means is provided at another installation location will be described.

  Fig. 12a is a frost distribution when there is little frost and the flow of cold air returning from the refrigerator compartment, and Fig. 12b is a top view of the cross section of the freezer compartment 5 when there is little frost. FIG. 13A is a view of the frost distribution when the frost is high and the flow of the refrigeration room return cold air, and FIG.

  The frost that grows in the cooler 7 is mainly caused by moisture contained in the cooler return cool air 57 that flows into the cooler 7 from the cooler cooler return duct 54. Since the refrigeration chamber cold air return duct 54 is a curved flow path, when the refrigeration chamber return cold air 57 flows from the lower part of the cooler 7, the flow is biased to the outside with a large bending radius. Therefore, the frost that grows in the cooler 7 begins to grow from the cooler 7 on the opposite side to the cold room cool air return duct 54 (left side as viewed from the front of the refrigerator 1), and gradually, the cold room cool air return duct 54 side. Grows towards.

  The frost distribution when there is little frost tends to be “dense” on the left side of the cooler 7 and “sparse” on the right side (see FIG. 12A). Since the amount of frost formation increases with the cooling time, the “dense” portion of the frost distribution expands to the right as the frost grows (see FIG. 13a). Means for predicting the amount of frost formation using the frost growth process of the cooler 7 will be described below.

The cold air flow when the refrigerator compartment 2 is cooled is as shown in FIGS. 12a and 13a.
12b and 13b are views of the cross section of the freezer compartment 5 as seen from above. The freezer compartment cool air return port 17 is provided in front of the cooler 7, and a temperature sensor 73 is provided on the left side of the freezer compartment cool air return port, a temperature sensor 74 is provided in the center, and a temperature sensor 75 is provided on the right side. The cold room return cold air 57 flowing in from the cold room cold air return duct 54 flows from the right side to the left side of the cooler 7 as shown in FIGS. 12a and 13a, and then the side wall surface of the cooler storage chamber 18 and the cooler. 7 flows to the upper part of the cooler 7 along the fins provided in FIG.

  When there is little frost, as shown to FIG. 12a, in the area | region 72 to which the refrigerator compartment return cold air 57 turns upwards, a pressure becomes high compared with the circumference | surroundings. When viewed from the front of the refrigerator, a pressure distribution is formed in which the pressure on the left side of the freezer compartment cold air return port 17 is high and gradually decreases as it moves to the right side, so that it is provided in front of the cooler 7 as shown in FIG. From the freezer compartment cold air return port 17, a part of the refrigerator compartment return cold air 57 flows into the freezer compartment 5, and a flow 76 due to the refrigerator compartment return cold air 57 is generated. As the amount of frost growing on the cooler 7 increases, the “dense” portion of the frost distribution expands to the right as the frost grows. Therefore, the high-pressure region 72 near the freezer compartment cold air return port 17 according to the phenomenon. However, it expands from the left to the right. In addition to the flow 76 formed when the frost is low, a flow 77 newly generated as the frost grows flows out into the freezer compartment 5. Since the refrigeration room return cold air 57 is higher than the temperature in the freezer compartment 5, if a part of it flows out, it can be easily detected by the temperature sensors 73, 74, and 75 provided in the freezer compartment cold air return port 17. Can do.

  FIG. 14 shows the sensor temperature of each part during the frost detection operation with respect to the frost amount G. It is the graph which showed the temperature detected with the temperature sensors 73, 74, and 75 provided in the freezer compartment cold air return port 17 at the time of completion | finish of frost formation amount detection operation with respect to frost formation amount. As the amount of frost formation increases, the temperature detected by the temperature sensor 73 decreases approximately linearly, the temperature detected by the temperature sensor 74 increases approximately linearly, and the temperature detected by the temperature sensor 75 becomes substantially constant. It has become clear through experiments.

  As described with reference to FIGS. 12 b and 13 b, when there is little frost, a high pressure region is formed on the left side of the freezer compartment cool air return port 17, so the temperature sensor 73 installed on the left side of the freezer compartment cool air return port 17 The detected temperature becomes higher due to the influence of outflow of the cold room return cold air 57, and the temperature detected by the temperature sensor 74 provided in the center of the freezer room cold air return port 17 and the temperature sensor 75 provided on the right side is the temperature returned to the cold room. Since the influence of the outflow of the cold air 57 is small, the temperature is lower than the temperature detected by the temperature sensor 73. As the frost increases, the “dense” portion of the frost distribution expands to the right as the frost grows, and accordingly, the high pressure region formed along the freezer compartment cold air return port 17 changes from left to right. Enlarge towards. When the portion where the frost distribution is “dense” reaches the vicinity of the temperature sensor 74, the temperature rise is noticeable due to the influence of the flow 77 caused by the outflow of the cold room return cold air 57 passing through the vicinity of the temperature sensor 74. It becomes like this. The temperature detected by the temperature sensor 75 is provided at the right side of the freezer compartment cold air return port 17 at the temperature sensor installation location, so that the portion where the frost distribution is “dense” is at the right end of the cooler 7. There is no noticeable temperature rise until it is reached.

  As described above, when the temperature sensor is provided in the freezer compartment cool air return port 17 to detect the amount of frost formation, the freezing chamber cool air return port 17 is provided near the center by using the frost growth process of the cooler 7. The temperature sensor 74 can also predict the amount of frost formation. The specific control method is the same as in the case described with reference to FIG. 8. When the temperature (T3) G detected by the temperature sensor 74 is compared with the temperature threshold (T3) Gt, the amount of frost formation is small. When the amount of frost formation is large, the heating control during defrosting can be performed in the same way as in FIGS. Further, the same control can be performed by using the respective temperatures detected by the temperature sensor 73 and the temperature sensor 74, or the temperature difference, and the difference between the freezer compartment temperatures detected by the temperature sensor 74 and the F sensor 43.

  The frost growth process of the cooler 7 is used to detect the temperature by a temperature sensor provided in the freezer compartment cold air return port 17 to predict the amount of frost formation, as shown in FIGS. 3 and 4a. The flow of cool air flowing into the cooler 7 becomes complicated, and the frost formation distribution of the cooler 7 may vary depending on how the refrigerator compartment 2 and the freezer compartments 4 and 5 are cooled. In such a case, in addition to the temperature sensor provided at the freezer compartment cold air return port 17, the temperature sensor 56 provided at the upper part of the cooler 7 is also used in combination to predict the amount of frost formation and improve the prediction accuracy. Is possible.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Refrigeration room 2a, 2b Refrigeration room door 3 Ice making room 3a Ice making room door 3b Storage container 4 Upper freezing room 4a Upper freezing room door 4b Storage container 5 Lower freezing room 5a Lower freezing room door 5b Storage container 6 Vegetable room 6a Vegetable Chamber door 6b Storage container 7 Cooler 8 Cooler storage chamber 9 Fan (cold air supply means)
DESCRIPTION OF SYMBOLS 10 Heat insulation box 11 Refrigeration room cold air duct 12 Upper freezer compartment cold duct 13 Lower freezer compartment cold air duct 17 Freezer room cold air return port 18 Vegetable room return air duct 18a Vegetable room return port 18b Vegetable room return discharge port 20 Refrigeration room damper (refrigeration temperature) (Cooling air adjustment means in the belt storage room)
21 Evaporation dish 22 Defrost heater (heating means)
23 樋 24 Compressor 25 Vacuum heat insulating material 27 Drain holes 28, 29 Heat insulating partition walls 33a, 33b, 33c Door pocket 34 Shelf 35 Depressurized storage chamber 40 Heat insulating partition wall 42 Cold room temperature sensor 50 Substrate cover 51 Control substrate 52 Outside temperature Sensor 53 Door hinge cover 54 Refrigeration room cold air return duct 55 Duct heater 56 Temperature sensor (temperature detection means)
57 Cold room return cold air 58 Machine room 60 Freezer compartment damper (Cooling air ventilation adjusting means for storage room in freezing temperature zone)
61 Bent part 62 Drain hole 63 Freezing chamber return cold air 70, 71 Frost
72 High pressure region 73, 74, 75 Temperature sensor (temperature detection means)
83 Wire connecting temperature T2

Claims (5)

A cold air supply means for supplying cold air to a storage room in a refrigerated temperature zone, a cooler for cooling the storage room in the refrigerated temperature zone, and the cooler, a compressor, a radiator, and a throttle are connected by a refrigerant pipe. Refrigeration cycle, temperature detection means provided in a part of the refrigerant pipe of the cooler, a cooler return duct for storing the cool air from the store chamber into the cooler, and a defrost for heating the cooler In the refrigerator including a heater and a duct heater for heating the storage room cold air return duct, after the compressor is stopped, the cold air is circulated for a predetermined time by the cold air supply means, and then the defrosting detected by the temperature detection means based on the temperature before the supply of the heater and the Dakutohita, the defrost heater whether to control the energization to the Dakutohita it is not energized, to energizing both the defrosting heater and the Dakutohita Refrigerator and determining whether to control the. A cooling air supply means for supplying cold air to a storage room partitioned into a refrigeration temperature zone and a freezing temperature zone, a cooler for cooling the storage chamber, and the cooler, compressor, radiator and throttle are connected by a refrigerant pipe. A refrigeration cycle constituted by the above, a temperature detection means provided in a part of the refrigerant piping of the cooler, a storage chamber cool air return duct for allowing cool air from the storage chamber to flow into the cooler, and heating the cooler In a refrigerator comprising a defrosting heater for heating and a duct heater for heating the storage room cold air return duct, after the compressor is stopped, the cold air in the storage room in the refrigeration temperature zone is circulated for a predetermined time by the cold air supply means , based on the temperature before the supply of the defrosting heater and the Dakutohita detected by said temperature detecting means, said defrosting or heater energized the Dakutohita performs control not energized, the defrost heater Contact Refrigerator and determining whether to perform control for energizing both fine the Dakutohita and. Cold air supply means for supplying cold air to a storage room partitioned into a refrigeration temperature zone and a freezing temperature zone; cold air blowing adjustment means for the storage room in the refrigeration temperature zone; and cold air blowing adjustment means for the storage room in the refrigeration temperature zone; A cooler for cooling the storage chamber, a refrigeration cycle configured by connecting the cooler, a compressor, a radiator, and a throttle with a refrigerant pipe, and temperature detection provided in a part of the refrigerant pipe of the cooler In a refrigerator comprising means, a storage room cold air return duct for allowing cold air from the storage room to flow into the cooler, a defrost heater for heating the cooler, and a duct heater for heating the storage room cold air return duct After the compressor is stopped, the air flow is stopped by the cool air blowing adjusting means of the storage room in the freezing temperature zone, and the cold air in the storage room in the refrigerated temperature zone is circulated for a predetermined time by the cold air supply means, and then the temperature detection By means Based on the temperature before the supply of the defrosting heater and the Dakutohita detected Te, the defrosting or heater energized the Dakutohita performs control not energized, the control for energizing both the defrosting heater and the Dakutohita A refrigerator characterized by determining whether to perform . The compressor is stopped, the refrigerant pipe is closed by an on-off valve provided in the refrigerant pipe between the cooler and the radiator, and the cold air in the storage room in the refrigerated temperature zone is cooled by the cold air supply means for a predetermined time. by circulating, after circulating the cold air in the storage chamber of the refrigeration temperature zone, and detecting the temperature before the supply of the defrosting heater and the Dakutohita by said temperature detecting means, to claim 1 4. The refrigerator according to any one of 3. Cold air supply means for supplying cold air to a storage room partitioned into a refrigeration temperature zone and a freezing temperature zone; cold air blowing adjustment means for the storage room in the refrigeration temperature zone; and cold air blowing adjustment means for the storage room in the refrigeration temperature zone; A cooler that cools the storage chamber, a refrigeration cycle configured by connecting the cooler, a compressor, a radiator, and a throttle with a refrigerant pipe, and the refrigeration temperature zone storage provided on the side of the cooler a chamber of the cool air return port, said cooler is provided in front the freezing temperature zone storage compartment of the cool air return port, a temperature sensing means in the cool air return port of the freezing temperature zone storage compartment provided to heat the cooler removal In a refrigerator having a frost heater and a duct heater for heating a cold air return port of the refrigerated temperature zone storage chamber , the compressor is stopped, and air blowing is stopped by the cold air blowing adjusting means of the refrigeration temperature zone storage chamber. The cold air supply means. After the cool air of the storage chamber of the temperature zone by a predetermined time circulation, wherein the defrost heater and the defrosting heater based on the temperature before the supply of the Dakutohita detected by the temperature detecting means is energized the Dakutohita is not energized A refrigerator which determines whether to perform control or to perform control to energize both the defrost heater and the duct heater .