JP5487053B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator.

  As background art of this technical field, there are JP-A-2006-183897 (Patent Document 1) and JP-A-2010-60188 (Patent Document 2).

  In the refrigerator described in Patent Literature 1, heat exchange performance is improved without increasing ventilation resistance in the absence of frost, and heat exchange performance in actual use can be ensured even when frost formation occurs. It describes the cooler shape and its surrounding air path structure. That is, for the main purpose of expanding the storage room (refrigeration room, vegetable room) provided above the cooler, a cooler with a larger depth and lower height than the conventional cooler is adopted. Yes.

  The refrigerator described in Patent Document 2 describes a refrigerator with high energy saving performance that suppresses the temperature rise of the storage room during defrosting. In a refrigerator having a freezer compartment in front of a cooler, a freezer compartment cool air return port is often provided above the defrost heater installation position, and the air heated by the defrost heater is from the freezer compartment cool air return port. It tends to flow out into the freezer compartment. In order to prevent heated air from flowing directly into the freezer compartment, a space is provided between the freezer compartment back member and the cooler cover provided on the front side of the cooler so that the heated air does not flow directly into the freezer compartment. As described above, the heated air is suppressed.

  As described above, in order to save energy during normal cooling and defrosting, there are a plurality of patent documents relating to the refrigerator shape of the refrigerator and its surrounding structure.

JP 2006-183897 A JP 2010-60188 A

  In Patent Document 1, the depth direction is made larger than the cooler conventionally used in refrigerators, mainly for the purpose of expanding the storage room (refrigerator room, vegetable room) provided above the cooler, and the height A cooler with a low direction is adopted. The storage room is arranged in order from the top: a refrigerator room, a vegetable room, and a freezer room, with a vegetable room in the middle. The cold air return port of the freezer compartment provided in front of the cooler is provided below the installation position of the defrost heater provided in the lower part of the cooler.

  At the time of defrosting, since the density of the air around the cooler heated by the defrosting heater is reduced, an upward flow is generated toward the upper part of the cooler. The air that has risen up the cooler flows out from the freezer compartment cool air outlet to the freezer compartment while defrosting the cooler, and then descends in the freezer compartment and heads again toward the freezer compartment cooler return port. That is, a circulation flow by natural convection is formed. The stronger the circulating flow, the quicker the frost that has grown on the cooler can be removed.

  However, the refrigerator described in Patent Literature 1 has a structure in which the freezer compartment cold air return port is provided at a position lower than the defrost heater installation position. Compared with this structure and the case where the freezer compartment cold air return port is provided at a position higher than the position where the defrost heater is installed, the circulation flow caused by heating of the defrost heater is weakened by the ventilation resistance of the freezer compartment cold air return port portion. . Therefore, since the freezer compartment cold air return port is provided at a position lower than the defrost heater installation position, it is difficult to actively generate a circulation flow, and no consideration is given to shortening the defrost time.

  In Patent Document 2, the storage room is arranged in the order of a refrigerator room, a freezer room, and a vegetable room from the top, and is a middle freezer room refrigerator in which a freezer room is provided in front of the cooler. In such a refrigerator, the freezer compartment cool air return port is often provided at a position higher than the defrost heater installation position, and the air heated by the defrost heater returns to the freezer compartment cool air with low ventilation resistance. It becomes easy to flow out of the mouth into the freezer. Therefore, a space is provided between the freezer compartment back member and the cooler cover provided on the front side of the cooler to prevent the heated air from flowing into the freezer compartment, thereby suppressing an increase in the thermal load of the freezer compartment.

  However, in the refrigerator described in Patent Document 2, there is no structural consideration for facilitating the flow of the air around the cooler heated by the defrost heater toward the upper side of the cooler and reducing the defrost time. . In particular, in a refrigerator using a flammable refrigerant, it is necessary to keep it lower than the surface temperature of the defrosting heater of a refrigerator that does not use a flammable refrigerant. This is because the surface temperature of the defrosting heater is set to the ignition point temperature or less assuming that the combustible refrigerant leaks into the cabinet. Therefore, in a refrigerator using a flammable refrigerant, it is necessary to lower the surface temperature of the defrost heater than before, so the upward flow of air generated by heating of the defrost heater tends to be weak, and from the viewpoint of energy saving Increasing the heater input to increase the surface temperature is not a good idea.

  Then, an object of this invention is to provide the refrigerator which shortens defrost time and has high energy saving property.

In order to achieve the above object, for example, the configuration described in the claims is adopted. As an example, it has a storage room of a refrigeration temperature zone and a freezing temperature zone, a cooler storage chamber provided behind the storage chamber of the freezing temperature zone, and a refrigerant pipe provided in the cooler storage chamber and through which a refrigerant passes. A cooler, a blower for blowing cool air from the cooler storage chamber to the storage chamber, a heat generating portion provided below the cooler, and the cool air blown to the storage chamber in the freezing temperature zone in the cooler storage chamber A refrigeration temperature zone cold air return port to return to the refrigeration temperature zone, and a cold air control means for controlling the amount of cold air supplied to the storage room in the refrigeration temperature zone and the storage chamber in the refrigeration temperature zone by opening and closing the cold air passage In the refrigerator, the refrigeration temperature chamber cold air return port is provided above the heat generating part, and the refrigerant pipe is arranged at an interval so as to be positioned forward and rearward from the upper projection surface of the heat generating part, respectively. , With the blower in operation The heat generating part is heated, and the cold air control means opens the cold air air passage to the storage room in the refrigeration temperature zone, closes the cold air air passage to the storage room in the freezing temperature zone, and stops the blower In the state, the heat generating unit generates heat, and the cold air control means closes the cold air flow path to the storage room in the refrigeration temperature zone and opens the cold air flow path to the storage room in the freezing temperature zone .

  ADVANTAGE OF THE INVENTION According to this invention, the defrost time can be shortened and the refrigerator with high energy saving property can be provided.

It is a front external view of the refrigerator which concerns on embodiment of this invention. It is a side longitudinal cross-sectional view of the refrigerator which concerns on embodiment of this invention. It is the figure which looked at the peripheral part of a cooler from the refrigerator front. It is detail drawing of a defrost heater. It is an example of AA sectional view of a defrost heater. It is another example of AA sectional drawing of a defrost heater. It is an example of the temperature detected with the defrost sensor at the time of defrost, and a time-dependent change of freezer compartment temperature. It is a side cross-section enlarged view around the cooler. It is a mimetic diagram about frost formation at the time of cooling of a cooler concerning an embodiment of the present invention. It is the figure which showed typically the mode at the time of frost formation at the time of changing the board thickness of a fin. It is a figure explaining the relationship between fin thickness and cooling performance. It is the figure which showed typically the mode at the time of defrosting of the cooler which concerns on embodiment of this invention. It is an expanded sectional view of the peripheral part of a cooler, and a freezer compartment. It is the figure which showed typically the mode at the time of defrosting of the cooler which concerns on the other Example of this invention. It is the figure which showed typically the mode at the time of defrosting of the cooler which concerns on the other Example of this invention. It is explanatory drawing of the time-dependent change of the defrost sensor temperature of the other defrost system regarding embodiment of this invention. It is control of the other defrost system regarding embodiment of this invention.

  As shown in FIG. 1, the refrigerator 1 according to the present embodiment includes a refrigerator compartment 2, an ice making compartment 3, an upper freezer compartment 4, a lower freezer compartment 5, and a vegetable compartment 6 from above. 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. The refrigerator 1 also has a door sensor (not shown) that detects the open / closed state of each door, and an alarm that informs the user when the state determined to be the door open state continues for a predetermined time, for example, 1 minute or more. (Not shown), a temperature setting device (not shown) for setting the temperature of the refrigerator compartment 2 and the freezer compartment 5 and the like are provided.

  As shown in FIG. 2, 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. The heat insulating box 10 of the refrigerator 1 has a plurality of vacuum heat insulating materials 25 mounted thereon. The refrigerator compartment 2 separates the refrigerator compartment 2 from the upper freezer compartment 4 and the ice making compartment 3 (see FIG. 1), and the insulated compartment wall 29 separates the lower freezer compartment 5 and the vegetable compartment 6 from each other. Yes. A plurality of door pockets 32 are provided inside the refrigerator compartment doors 2 a and 2 b (see FIG. 1), and the refrigerator compartment 2 is partitioned into a plurality of storage spaces in the vertical direction by a plurality of shelves 36. A freezer compartment front partition 40 is provided between the upper freezer compartment 4 and the lower freezer compartment 5.

  The upper freezer compartment 4, the lower freezer compartment 5, and the vegetable compartment 6 are each provided with storage containers 3b, 4b, 5b, 6b integrally with a door provided in front of each, and a handle portion of each door (not shown) ) And withdrawing it toward the front side, the storage containers 4b, 5b, 6b can be pulled out. The ice making chamber 3 shown in FIG. 1 is also provided with a storage container 3b integrally with the ice making chamber door 3a, and the storage container 3b can be pulled out by placing the hand on the handle of the ice making door 3a and pulling it out to the front side. Yes.

  The cooler 7 is provided in a cooler storage chamber 8 provided substantially at the back of the lower freezing chamber 5, and exchanges heat with the cooler 7 by an internal fan 9 (blower) provided above the cooler 7. The cooled air (hereinafter referred to as “cold air”) passes through the refrigerator compartment air duct 11, the upper freezer compartment air duct 12, the lower freezer compartment air duct 13, and the ice making room air duct (not shown). It is sent to the respective storage rooms of the refrigerator compartment 2, the upper freezer compartment 4, the lower freezer compartment 5, and the ice making room 3.

The air blowing to each storage room is controlled by opening / closing a refrigerator compartment damper 20 (hereinafter referred to as “R damper”) and a freezer compartment damper 50 (hereinafter referred to as “F damper”) as cold air control means.
Specifically, when the R damper 20 is in the open state and the F damper 50 is in the closed state, the cold air is sent to the refrigerating chamber 2 from the blowout ports 2 c provided in multiple stages via the refrigerating chamber air duct 11. After the cooling of the refrigerating chamber 2 is finished, cold air flows into a refrigerating chamber return port (not shown) provided in the lower portion of the refrigerating chamber 2 and then returned to the cooler storage chamber 8.

  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 a cool air generated in the cooler 7 does not pass through the refrigerator compartment 2. Thus, a method of sending it alone to the vegetable compartment 6 can be considered. However, in this case, in order to control the cool air supplied to the vegetable compartment 6, a damper dedicated to the vegetable compartment is required. In the present embodiment, 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 passes through the vegetable compartment return duct 18 from the vegetable compartment return port 6 d provided in front of the lower part of the heat insulating partition wall 29, and then returns to the vegetable compartment return discharge port 18 a. To the cooler 7.

  Air is sent from the cooler storage chamber 8 through the upper freezer compartment air duct 12, the lower freezer compartment air duct 13, and the ice making duct (not shown) to cool the upper freezer room 4, the lower freezer room 5, and the ice making room 3. The cooled air after being returned to the cooler 7 from the freezer return port 17. A defrost heater 22 which is a heat generating part is provided at the lower part of the cooler 7, and drain water generated at the time of defrosting once falls on the toy 23 and is provided on the head of the compressor 24 through the drain hole 27. 21 is released.

  Next, FIG. 3 is the figure which looked at the peripheral part of the cooler 7 from the refrigerator front. FIG. 4 is a detailed view of the defrost heater 22. 5 and 6 are AA cross-sectional views of the defrost heater 22. A defrost sensor 41 is installed in the upper part of the cooler 7, and a determination related to defrost is performed based on the temperature detected by the defrost sensor 41. When the cooler 7 is heated from the lower part, the defrost sensor 41 is generally provided on the upper stage side of the cooler 7.

  As shown in FIG. 5, the defrost heater 22 includes a glass tube 44 provided with an electric heater (not shown) and a metal fin 45 (radiation fin) provided on the outer periphery of the glass tube 44, As shown in FIG. 6, there is a double glass tube structure including a glass tube 44 provided with an electric heater wire (not shown) and a glass tube 59 on the outer periphery thereof. These are examples of the defrosting heater 22 employed in a refrigerator that uses a flammable refrigerant. Assuming that the flammable refrigerant leaks in the refrigerator, the surface temperature of the outer glass tube is ignited by the flammable refrigerant. A contrivance has been made to make the temperature lower by about 100 ° C. than the point temperature (494 ° C. for isobutane). Power is supplied to the defrosting heater 22 by a cord 57 connected to both ends of the heater. Since defrost water is dripped from the upper part of the defrost heater 22 at the time of defrosting, the defrost water dripping prevention part 43 is provided in the upper part of the glass tubes 44 and 59. FIG. This is because if the defrost water is directly dropped onto the glass tubes 44 and 59 heated to a high temperature, the glass may be damaged due to a rapid temperature change. In order to prevent this phenomenon, the width B of the defrost water dripping preventing portion 43 is set to be at least the outer diameter C of the defrost heater 22 or more. In consideration of the ventilation resistance during the cooling operation, it is preferable that the width B and the diameter C are substantially equal. In the defrosting heater 22 using a flammable refrigerant, for example, the outer diameter C of the metal fin 45 is φ28 mm, and the outer diameter of the glass tube 44 is φ10 mm.

  In general, the defrosting heater 22 of the refrigerator that employs the flammable refrigerant is configured by the metal fin 45 or the glass tube 59 provided on the outer peripheral portion of the glass tube 44 and the defrosting water dripping preventing unit 43. . Since the metal fin 45 (or the glass tube 59) and the defrost water dripping prevention part 43 are provided in the vicinity of the glass tube 44 provided with the heater wire inside, the respective surface temperatures are sufficiently high to defrost. In addition, the glass tube 44, the metal fin 45, the glass tube 59, and the defrost water dripping prevention unit 43 can be defined as a heat generating unit (defrost heater 22). Further, a thermal fuse 42 for preventing the defrost heater 22 from being overheated is provided below the cooler 7.

  When the cool air sent to the refrigerator compartment 2 is returned directly to the cooler 7 without going through the vegetable compartment 6, a refrigerator compartment cool air return air passage 46 is provided beside the cooler 7 as shown in FIG. Yes, the cold air returning from the refrigerator compartment flows from the side of the cooler 7.

  Next, FIG. 7 is an example of the change over time of the temperature detected by the defrost sensor 41 during defrosting (hereinafter referred to as “defrost sensor temperature”) and the freezer compartment temperature during defrosting. If the defrost sensor temperature at the start of defrosting (time t0) is TD0, the temperature gradually increases after the start of defrosting. And while the frost is thawed, it changes at about 0 ° C. because the phase is changing. When the defrosting is finished, the defrosting sensor temperature rises again, and when the defrosting end temperature TD1 is reached (time t1), the defrosting heater 22 is deenergized and the defrosting is completed.

  Since the frost is melted from the lower part to the upper part of the cooler 7, the temperature detected by the defrost sensor 41 is different from the temperature aging of the lower part of the cooler 7, and the frost at the lower part of the cooler 7 is first melted. . Therefore, the time zone in which about 0 ° C. transitions ends first at the lower part of the cooler 7.

  During defrosting, the freezing temperature zone (ice-making room 3, upper freezing room 4, lower freezing room 5) is not cooled, so the freezing room temperature is changed from TF0 (defrosting start time t0) to TF1 (defrosting end time). rise to t1). For example, even if the amount of frost formation is the same, the defrost time may change due to the upward flow of air generated by the heating of the defrost heater 22. When the time to reach the defrosting end temperature TD1 is changed from t1 to t2, the defrosting time becomes longer (broken line in the graph), so the amount of electric power consumed by the defrosting heater is increased and the defrosting heater 22 is heated. The heat load to the inside increases by the amount. This affects the increase in the amount of power during recooling after the completion of defrosting. Moreover, since the temperature of a freezing temperature zone room will rise to TF2, it will affect the preservability of frozen food. Therefore, shortening the defrosting time with a small heater heating amount in order to suppress an increase in the thermal load in the cabinet by the defrosting heater 22 is useful for improving energy saving and improving the storage stability of frozen foods.

  Next, FIG. 8 is a sectional view around the cooler 7. The cooler 7 is installed in a cooler storage chamber 8 whose front and rear sections are partitioned by an inner back wall 65 of the heat insulation box 10 and a cooler cover 62. A freezing temperature zone back member 58 is provided on the front side of the cooler cover 62, and the lower freezer compartment air duct 13 (or the upper freezer compartment) is provided between the cooler cover 62 and the freezing temperature compartment back member 58. An air duct 12) is formed. A bypass air path 60 is provided on the front side of the cooler 7, and a bypass air path 61 is provided on the back side of the cooler 7. These bypass air passages 60 and 61 are provided so that the cooling performance can be maintained for a predetermined time even when a large amount of frost grows in the lower part of the cooler 7. The shape of the bypass air passages 60 and 61 is determined according to the form of the cooler 7 and the cold air air passage. When the bypass air passages 60 and 61 are not provided, almost no gap is formed between the cooler cover 62 and the cooler 7, and the inner back wall 65 and the cooler 7.

  Immediately after the start of the defrosting, there is a possibility that the air heated by the defrosting heater 22 may flow in the direction of the refrigeration temperature chamber cold air return port 17 due to the draft resistance of the frost that has grown in the lowermost stage of the cooler 7. is there. Between the cooler cover 62 and the refrigeration temperature zone chamber back member 58, a heated air inflow space 64 opened downward is provided. That is, there is a space between the lower freezing chamber 5 and the cooler housing chamber 61 where the lower portion opens and the air heated by the heat generating portion flows in. Thereby, since the air heated with the defrost heater 22 can once be introduce | transduced into the heating air inflow space 64, the heat load inflow to a freezing temperature zone room can be prevented to the minimum.

  As mentioned above, it turns out that the flow of the air heated with the defrost heater 22 is greatly influenced by the ventilation resistance at the time of passing a frost and a cooler. In particular, in a refrigerator in which the refrigeration temperature chamber cold air return port 17 is provided at a position higher than the defrost heater 22 and the upper limit of the surface temperature of the defrost heater 22 is limited in order to use a flammable refrigerant, the flow is defrosted. Greatly affects efficiency.

  Next, the flow of the defrost heater 22 and the heated air will be described. 8 to 15, the horizontal distance between the outer surfaces of the cooler pipes 54a and 54b adjacent to each other in front and rear is A1, and the outer surface of the cooler pipe 54a facing the cooler cover 62 and the cooler cover 62 side. The horizontal distance is A2, the horizontal distance between the outer surface of the opposing cooler pipe 54b and the inner back wall 65 is A3, and the diameter of the defrost heater 22 is C. In addition, it is assumed that frost grows in each area represented by a broken line.

  First, the stage where frost grows will be described. FIG. 9 is an embodiment of the present invention, and is a schematic diagram showing frost formation during cooling when the horizontal distance A1 between the outer surfaces of the adjacent cooler pipes 54a and 54b is larger than the diameter C of the defrost heater 22. is there. FIG. 9A shows a case where the distance A1 is smaller than the diameter C of the defrost heater 22, and FIG. 9B shows a case where the distance A1 is larger than the diameter C of the defrost heater 22. The mode of frost formation in the lowest step part of the vessel 7 is shown. The cooler 7 has the most frost formation at the lowermost step, and the manner of frosting greatly affects the defrosting time, so attention is paid to the frost formation at the lowermost step.

  The fin width of the cooler 7 is F, the height of frost growing around the refrigerant pipes 54a and 54b is Lf1, the horizontal distance from the outer surfaces of the refrigerant pipes 54a and 54b is D, and the outside of the refrigerant pipes 54a and 54b. The horizontal distance from the surface to the fin end is E, and the fin pitch is Pf.

9 (a) and 9 (b), the cool air returns to the lowermost stage of the cooler 7 from the lower side and the front side (left side of FIG. 9) of the lowermost stage of the cooler 7, so that the front edge of the fin The frost 71 tends to increase.
The surface of the refrigerant pipes 54a and 54b has the lowest temperature, but the moisture of the return cold air flowing into the front edge of the fin is defrosted and dehumidified, and the frost 70 around the refrigerant pipes 54a and 54b The height is the same as or lower than the frost height at the edge. The frost 70 that grows around the refrigerant pipes 54a and 54b tends to grow a lot on the side where the return cold air enters. When the fin pitch Pf is 5 mm, defrosting is performed before the gap between the fins is closed in the refrigerator 1, so that the height Lf1 of the frost growing around the refrigerant pipes 54a and 54b is 2.5 mm or less at the highest. .

  For example, when the distance A1 shown in FIG. 9A is smaller than the diameter C of the defrosting heater 22, the fin width F = 60 mm, A1 = 16.6 mm, C = 28 mm, E = 13.3 mm, Lf1 = 2. If the horizontal distance between the outer surfaces of the frost that has grown around the refrigerant pipes 54a and 54b is G, G = 11.6 mm. Accordingly, the horizontal distance G where the amount of frost formation is smaller than that around the refrigerant pipes 54 a and 54 b is smaller than the diameter C of the defrost heater 22, and the upward flow generated by heating by the frost 70 during defrosting. It is easy to disturb.

  On the other hand, when the distance A1 shown in FIG. 9B is larger than the diameter C of the defrosting heater 22, the fin width F = 77 mm, A1 = 41.6 mm, C = 28 mm, E = 9.3 mm, Lf1 = 2.5 mm. Assuming that the distance between the outer surfaces of the frost grown around the refrigerant pipes 54a and 54b is G, G = 36.6 mm. In this case, the horizontal distance D between the refrigerant pipe 54a and the defrosting heater 22 facing the refrigerant pipe 54a is 6.8 mm, and even if the height Lf1 of the frost growing around the refrigerant pipes 54a and 54b is 3 mm, The tip of the frost that grows around 54b does not reach the defrost heater 22. Therefore, the horizontal distance G where the amount of frost formation is relatively smaller than the surroundings of the refrigerant pipes 54a and 54b is larger than the diameter C of the defrost heater 22, and promotes the upward flow generated by heating during defrosting. It becomes easy.

  Since heat transfer is promoted at the front edge of the fin, frost is likely to grow, and air resistance is likely to occur.However, by increasing the horizontal distance A1, the horizontal distance G is also increased, and the wind speed U passing through the horizontal distance G portion is increased. Since it can be slowed down, increasing the horizontal distance A1 between the outer surfaces of the adjacent refrigerant pipes 54a and 54b contributes to a reduction in the ventilation resistance of the entire cooler.

  Next, FIG. 10 schematically shows a state of frost formation when the plate thickness of the fin is changed. Generally, when the pitch between the refrigerant pipes 54a and 54b is increased (equivalent to increasing the horizontal distance A1 between the outer surfaces of the adjacent refrigerant pipes 54a and 54b), the fin efficiency between them decreases, so that cooling is performed. The overall performance of the vessel is reduced. Therefore, in the case of the conventional fin thickness 72 shown in FIG. 10A, if the horizontal distance A1 is increased, the fin efficiency between the refrigerant pipes is lowered. Therefore, the height of the frost Lf2 that grows on the fin surface decreases toward the center of the refrigerant pipes 54a and 54b. This is due to a decrease in cooling performance accompanying a decrease in fin efficiency. On the other hand, in the case of fin thickness 73 in which the fins are thicker than the conventional one shown in FIG. 10 (b), the fin efficiency between the refrigerant pipes 54a and 54b can be increased. It can be seen that the height of the frost Lf2 that grows rapidly increases.

  The above phenomenon will be further described with reference to FIG. FIG. 11 shows the relationship between fin thickness and cooling performance. When the number of rotations of the internal fan 9 is constant, the fin efficiency increases when the fin thickness is increased, so that the cooling performance increases. Moreover, since fin efficiency between refrigerant pipes will fall if distance A1 is made longer than before, it is better to thicken the fins to compensate for this. Regarding the fin thickness, there is a fin thickness at which the fin efficiency becomes 100%, and even if the fin is thickened further, the cooling performance cannot be improved. If the fins are made thicker than necessary, the distance between the fins becomes small, and the cooling performance deteriorates due to the influence of blockage due to frost.

  In summary, the horizontal distance A1 between the outer surfaces of the adjacent refrigerant pipes 54a and 54b is made larger than the diameter C of the defrost heater 22 so that the amount of frost formation is smaller than that around the refrigerant pipes 54a and 54b. It can arrange | position so that the diameter C of the defrost heater 22 may be located. At the time of defrosting, the heated air rises just above the diameter C of the defrosting heater 22, so that the defrosting phenomenon is promoted and the defrosting time is shortened.

  Next, the stage where frost can be dissolved will be described. FIG. 12 schematically shows how to defrost frost when the horizontal distance A1 between the outer surfaces of the adjacent refrigerant pipes 54a and 54b is larger than the diameter C of the defrost heater 22. In FIG. 12, the frost around the refrigerant pipe shown in FIG. 9 is omitted in order to explain the overall defrosting of the cooler 7, but the frost distribution follows FIG. When fixing fins to the refrigerant pipes 54a and 54b, a fin collar is often provided, and the portion is thicker by the fin thickness than the outer diameter of the cooler pipe, but the thickness is larger than the horizontal distance A1. Is sufficiently small, the fin collar portion is not considered.

  The structure around the cooler 7 is simplified in order to explain mainly the flow of the rising flow 55 and the way of melting frost, but the cooler 7 is provided in the portion shown in FIG. Fig. 12 (a) shows the start of defrosting (time t0), Fig. 12 (d) shows the end of defrosting (time t1), and Figs. 12 (b) and 12 (c) schematically show the defrosting process during that time. It is.

  The frost 52 that grows on the cooler 7 grows more on the lowermost stage of the cooler 7 near the refrigeration temperature chamber cold air return port 17 side, and more frost grows on the fin front edge of the cooler 7. At the start of the defrosting in FIG. 12A, the ambient air is heated by the defrosting heater 22, and an upward flow 55 toward the lowermost stage of the cooler 7 is generated. This upward flow 55 is most strongly generated immediately above the defrost heater 22, that is, directly above the horizontal distance C (the diameter C of the defrost heater). Although the frost is gradually heated by the upflow 55 and begins to melt, at the initial stage of defrosting, when there is a lot of frost that has grown in the lowermost stage of the cooler 7, the upflow 55 is directed to the freezing temperature zone cold air return port 17 side. An outflowing flow 56 (see FIG. 8) may be generated, and the heated air inflow space 64 makes it difficult for the outflow to flow directly into the freezing temperature zone chamber.

  As the frost at the lowermost stage of the cooler 7 is melted, the horizontal distance A1 is larger than the diameter C of the defrost heater 22, so that the frost just above the defrost heater 22 is easily melted, as shown in FIG. The defrost promotion part 66 comes to be seen. This is because the upward flow 55 formed on the defrosting heater 22 has a horizontal distance A1 larger than the diameter C of the defrosting heater 22, and therefore the upward flow 55 is resisted by ventilation from the refrigerant pipes 54a and 54b. This is because the frost melting at the horizontal distance A1 is accelerated.

  Moreover, as shown in FIG. 9, since the frost of the fin part of each step | level just above the diameter C of the defrost heater 22 has relatively decreased, horizontal distance A1 part is reduced in a defrost process. Ascending flow 55 becomes easy to flow, a flow is actively generated from the lowermost step portion of the cooler 7 toward the uppermost step portion, and heat is easily transferred to the fins of each step of the cooler 7 (FIG. 12B). The heat transfer path 67) indicated by the arrow in FIG. The defrost sensor 41 is preferably installed above the cooler 7 at a place other than the horizontal distance A1 (outside from between the refrigerant pipes located at the front and rear) where the strong upward flow 55 is likely to be generated.

  Next, FIG. 13 is a cross-sectional view of the vicinity of the cooler 7 and the freezing temperature zone (upper freezing chamber 4, lower freezing chamber 5). In FIG. 9, the defrosting process is schematically described focusing on the cooler, but here, a path including the freezing temperature zone of the upward flow 55 of the air generated during the defrosting will be described. Since the horizontal distance A1 is larger than the diameter C of the defrost heater 22, the upward flow 55 generated by the heating of the defrost heater 22 easily flows through the horizontal distance A1.

  After the upward flow 55 passes through the uppermost stage of the cooler 7, it passes through the internal fan 9 and the freezer damper 50 and flows out mainly from the freezer outlet 51 a to the upper freezer 4. In the refrigerator equipped with the freezer compartment damper 50, it is better to open the freezer compartment damper 50 so that the upward flow 55 flows out from the freezer outlet 51a to the upper freezer compartment 4. When the freezer compartment damper 50 is closed, it is difficult for the upward flow 55 to be generated. Will be heated. The upward flow 55 flowing out into the upper freezer compartment 4 is then cooled by the upper freezer compartment 4 and the lower freezer compartment 5, so that it becomes a downward flow 63 and descends the upper freezer compartment 4 and the lower freezer compartment 5 to freeze again. It flows into the cooler housing chamber 8 from the temperature zone chamber cold air return port 17.

  In this manner, a circulating flow is formed by the upward flow 55 that goes from the bottom to the top of the cooler 7 and the downward flow 63 that goes from the top to the bottom of the upper freezing chamber 4 and the lower freezing chamber 5.

  When the strong upward flow 55 is generated, the heat of the defrost heater 22 is quickly transmitted to the upper part of the cooler 7 (heat transfer path 67 in FIG. 12B), so that the frost can be easily dissolved. At the same time, the downflow 63 also becomes strong, so that the flow of the heated air 56 flowing out from the freezing temperature zone cold air return port 17 opposite to the downflow 63 into the lower freezing chamber 5 is suppressed.

  As described above, the refrigerant pipes 4a and 54b are arranged at intervals so as to be positioned forward and rearward from the upper projection surface of the heat generating portion (defrost heater 22). By passing the upward flow 55 having a strong range of 1 through the distance A1, the defrosting time can be shortened by the circulating flow caused, and energy saving can be achieved.

  Next, FIG. 14 shows another embodiment according to the present invention. FIG. 14A schematically shows the defrosting process (time t0), and FIG. 14B schematically shows the defrosting process. A horizontal distance A2 between the outer surface of the refrigerant pipe 54 a facing the cooler cover 62 and the cooler cover 62, and a diameter C of the defrost heater 22. By making the horizontal distance A2 larger than the diameter C of the defrost heater 22, frost tends to grow around the pipe of the cooler 54a during cooling, but since the horizontal distance A2 is increased, the fin front side (freezer compartment side) ) To grow frost. Accordingly, during the defrosting, the upward flow 55 easily flows from the lowermost step portion of the cooler 7 to the uppermost step portion through the horizontal distance A2. As shown in FIG. 14B, the frost 52 that has grown on the cooler 7 is gradually melted, and a defrost promoting portion 66 appears at the horizontal distance A2 portion. Thereby, the defrost promotion part 66 gradually proceeds to the uppermost part of the cooler 7, and a circulation flow is formed by the upward flow 55 and the downward flow 63 generated in the freezer compartments 4, 5. Frost melting is promoted. The installation place of the defrost sensor 41 is a place other than the horizontal distance A2 where a strong upward flow 55 is likely to be generated, and is preferably above the cooler 7.

  Next, FIG. 15 shows another embodiment according to the present invention. FIG. 15 (a) schematically shows the defrosting process (time t0), and FIG. 15 (b) schematically shows the defrosting process. If the horizontal distance A3 between the outer surface of the refrigerant pipe 54b facing the inner back wall 65 and the inner rear wall 65 and the diameter C of the defrost heater 22 are set, the horizontal distance A3 is made larger than the diameter C of the defrost heater 22. . Thereby, frost easily grows around the pipe of the cooler 54b during cooling, but since the horizontal distance A3 is increased, frost growing on the fin rear side (back side) can be suppressed. Accordingly, during the defrosting, the upward flow 55 easily flows from the lowermost step portion of the cooler 7 to the uppermost step portion through the horizontal distance A3. As shown in FIG. 15B, the frost 52 grown on the cooler 7 is gradually melted, and the defrost promoting part 66 appears at the horizontal distance A3.

  Thereby, the defrost promotion part 66 gradually proceeds to the uppermost part of the cooler 7, and a circulation flow is formed by the upward flow 55 and the downward flow 63 generated in the freezer compartments 4, 5. The frost melts easily. Similarly, in this case, the defrost sensor 41 is preferably installed at a location other than the horizontal distance A3 where the strong upward flow 55 is likely to be generated and above the cooler 7.

  Next, FIG. 16 is explanatory drawing of the time-dependent change of the defrost sensor temperature of the other defrost system regarding embodiment of this invention. In the refrigerator provided with the F damper 50 and the R damper 20, not only the frost that has grown on the cooler 7 can be released, but at the same time, the refrigerator compartment 2 and the vegetable compartment 6 can be cooled by frost (mainly frost latent heat). Defrosting from the start of defrosting (time t0, defrosting sensor temperature TD0) until the defrosting sensor temperature reaches TDA (for example, TDA is 3 ° C., time tA) is section A, and from defrosting sensor temperature TDA to TD1 (time t1) ) Is defrosting that combines section A and section B. In the refrigerator not provided with the F damper 50, the defrosting of the section B is performed only by the defrosting heater 22.

  FIG. 17 shows another defrosting system control relating to the present invention. When the conditions of the compressor operating time and the outside air temperature are satisfied, the defrosting operation is started (S1), and the defrosting in the section A of FIG. 16 is performed (S2). In the section A, the internal fan 9 and the defrost heater 22 are turned on, the R damper 20 is opened, and the F damper 50 is closed. When the air heated by the defrost heater 22 passes through the cooler 7, it is cooled by the cold energy of the frost, and the cold air is supplied to the refrigerator compartment (including the vegetable compartment in the refrigerator temperature zone). proceed. Since the energization amount of the defrost heater 22 is operating the internal fan 9, the defrost heater 22 alone or the vegetable room 6 uses the internal heat load of the refrigerator compartment 2 or the defrost heater 22 alone. Energy saving can be achieved. The defrosting in the section A is performed until the defrosting sensor temperature reaches the TDA (S3), and when the defrosting sensor temperature becomes equal to or higher than the TDA (time tA), the defrosting is switched to the defrosting in the section B (S4).

  In section B, the internal fan 9 is OFF, the defrost heater 22 is ON, the R damper 20 is closed, and the F damper 50 is open. Section B is a conventional defrosting method using only the defrosting heater 22 and is heated by the defrosting heater 22 until the defrosting sensor temperature reaches TD1 (S5), and when the defrosting heater temperature reaches TD1 ( Defrosting ends at time t1) (S6). In order to perform defrosting while performing cooling using the latent heat of frost, the defrost sensor temperature TDA is desirably at least 0 ° C. or higher. In section B where the defrost sensor temperature is TDA or higher, there is often no frost remaining, but in section B, the cooler 7 is heated until the defrost sensor temperature reaches TD1 for reliability. .

  Since the internal fan 9 is operated in the section A, the air passing through the cooler 7 is forced convection, but in the section B, the lowermost stage of the cooler 7 is operated by the action of the upward flow 55 by the defrost heater 22 as usual. Heat is transferred from the section to the top stage.

  As described above, the strength of the circulating flow composed of the upward flow 55 passing through the cooler 7, the downward flow 63 descending the upper freezing chamber 4 and the lower freezing chamber 5 affects the defrosting end time. Therefore, in the refrigerator provided with the F damper 50, it is better to open the F damper 50 in the section B so as to easily form a circulation flow. The air path that passes through the R damper 20, the refrigerating chamber discharge port 2 c, and the refrigerating chamber return duct 46 and returns to the cooler 7 has a larger air path than the circulation path composed of the upflow 55 and the downflow 63 centering on the freezer Since it becomes longer, the ventilation resistance is large, and it is difficult to open the R damper 20 and generate a circulating flow in the refrigerator compartment. Therefore, the defrosting end time affects the opening and closing of the F damper 50. When defrosting by the defrosting heater 22 in the section B, the defrosting time ends earlier when the F damper 50 is opened (solid line in FIG. 16), and when the F damper 50 is closed, no circulation flow is formed. The frost time becomes longer (broken line in FIG. 16).

  As described above, in the refrigerator having the F damper 50, in the section heated only by the defrost heater 22, the condition that the F damper 50 is opened is added, and the horizontal distance A1 between the outer surfaces of the adjacent refrigerant pipes 54a and 54b, The horizontal distance A2 between the outer surface of the refrigerant pipe 54a and the cooler cover 62, the horizontal distance A3 between the outer surface of the refrigerant pipe 54b and the wall surface 62 that forms the inner rear surface, and the diameter C of the defrosting heater 22 are as described above. . As a result, the circulation flow composed of the upflow 55 and the downflow 63 can be further strengthened by opening the F damper 50.

  The present invention has the following effects. First, a storage room of a refrigeration temperature zone and a freezing temperature zone, a cooler chamber provided behind the storage chamber of the freezing temperature zone, a cooler having a refrigerant pipe provided in the cooler chamber and through which the refrigerant passes, A blower that blows cool air from the cooler room to the storage room, a heat generating portion provided below the cooler, and a freezing temperature zone cold air that returns the cool air blown to the freezing temperature zone storage room to the cooler room In the refrigerator including a return port, the freezing temperature chamber cold air return port is provided above the heat generating unit, and the refrigerant pipe is positioned forward and rearward of the upper projection surface of the heat generating unit. Arrange them at intervals.

  Thereby, since the upward flow of the air heated by the heat generating part (defrost heater) can be strengthened, the defrost is promoted by flowing between the refrigerant pipes adjacent to the cooler, and the defrost time is shortened. Can do. In addition, a downward flow is generated in the refrigeration temperature zone due to the upward flow, so that a circulation flow that flows through the cooler and the refrigeration temperature zone chamber is formed, and the refrigeration temperature zone cold air return port is above the heat generating part. Even if it exists, it can suppress that the upward flow of heating air flows out from a freezing temperature zone room cold-air return port directly, and it is useful for prevention of the thermal load increase of a freezing temperature zone room.

  Next, the distance between the front wall (cooler cover 62) of the cooler storage chamber and the outer diameter end of the refrigerant pipe is larger than the width of the heat generating portion. Thereby, since the upward flow of the air heated with the defrost heater can be strengthened between the refrigerant pipe outer surface facing the cooler side wall surface of the cooler cover 62, defrosting is promoted and defrosting is performed. Time can be shortened and energy saving effect can be obtained.

  Next, the distance between the rear wall of the cooler storage chamber (the inner rear wall 65) and the outer diameter end of the refrigerant pipe is larger than the width of the heat generating portion. Thereby, since the upward flow of the air heated by the defrost heater can be strengthened between the refrigerant pipe outer surface facing the inner back wall 65, the defrost is promoted and the defrost time is shortened. Energy saving effect can be obtained.

  Next, a cool air control means for controlling a supply amount of the cool air to the storage room in the freezing temperature zone by opening and closing a cool air air passage is provided, and the heat generating portion is caused to generate heat while the blower is stopped, so that the cool air The control means opens the cold air passage. Thereby, the upward flow of the air by the heating of the defrost heater is caused to flow into the refrigeration temperature zone chamber, and the circulation flow descending toward the refrigeration temperature zone cool air return port is further easily formed. Therefore, an energy saving effect is obtained.

  Next, there is a space above the heat generation unit and between the cooler storage chamber and the storage chamber, and a space into which air heated by the heat generation unit flows. Thereby, immediately after the start of defrosting with a large amount of frost at the lower part of the cooler, the ventilation resistance due to frost tends to increase, and the upward flow generated by heating with the defrosting heater tends to flow out from the freezer compartment cold air return port, By providing the heated air inflow space, an increase in heat load on the freezer is suppressed.

DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Refrigerated room 4 Upper freezer room 5 Lower freezer room 7 Cooler 8 Cooler storage room 9 Fan in fan (blower)
11 Refrigeration room air duct 12 Upper freezer room air duct 13 Lower freezer room air duct 17 Freezing temperature zone room cold air return port 20 Cold room damper (R damper, cold air control means)
22 Defrost heater (heat generating part)
41 Defrost sensor 42 Thermal fuse 43 Defrost water dripping prevention part 44, 59 Glass tube 45 Metal fin (radiation fin)
50 Freezer compartment damper (F damper, cool air control means)
51a, 51b, 51c Freezer compartment outlet 52 Frost 53 Defrosted water 54a, 54b Refrigerant pipe 55 Upflow 56 Flow in the direction of freezer compartment cold air return port 58 Refrigerant temperature zone back member 60, 61 Bypass air path 63 Lower Flow 64 Heated air inflow space 65 Inside rear wall 66 Defrost promoting portion 67 Heat transfer path

Claims (2)

A refrigerating temperature zone and a freezing temperature zone storage chamber, a cooler storage chamber provided behind the freezing temperature zone storage chamber, a cooler having a refrigerant pipe provided in the cooler storage chamber and through which the refrigerant passes, A blower that blows cool air from the cooler storage chamber to the storage chamber, a heat generating portion provided below the cooler, and a freezing temperature zone that returns the cool air blown to the storage chamber of the freezing temperature zone to the cooler storage chamber In a refrigerator comprising: a room cold air return port; and a cold air control means for controlling the amount of cold air supplied to the storage room in the refrigeration temperature zone and the storage room in the freezing temperature zone by opening and closing a cold air passage .
The refrigeration temperature chamber cold air return port is provided above the heat generating part, and the refrigerant pipe is disposed at an interval so as to be located in front and rear of the upper projection surface of the heat generating part, respectively .
The cold air control means opens the cold air flow path to the storage room in the refrigeration temperature zone and opens the cold air flow path to the storage room in the refrigeration temperature zone while the air blower is operated. As closed
The heat generating unit generates heat while the blower is stopped, and the cold air control means closes the cold air flow path to the storage room in the refrigeration temperature zone and opens the cold air flow path to the storage room in the freezing temperature zone. A refrigerator characterized by being opened . A horizontal distance A1 between the outer surfaces of the front and rear refrigerant pipes is larger than a diameter C of the heat generating portion, and a distance G between the outer surfaces of the frost grown around the front and rear refrigerant pipes is the heat generation. The refrigerator according to claim 1, wherein the refrigerator is larger than a diameter C of the portion .

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