JP2015025566A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator provided with a cooler having high defrosting efficiency.SOLUTION: The refrigerator includes a defrosting heater 47 disposed below a cooler; and a control part 63 controlling power distribution to the defrosting heater. The control part 63 is structured to start the power distribution to the defrosting heater 47 after the lapse of a predetermined period of time by stopping a compressor 61. According to such a structure, the upper part of the cooler is defrosted also from the inside of a refrigerant pipe by heat transmission via high temperature refrigerant in the lower part refrigerant pipe heated by the defrosting heater in addition to defrosting due to radiation heat/convection heat from the defrosting heater in defrosting operation, and also the heat transmission by the high temperature refrigerant can be effectively performed because of using bursting force of foam due to bumping boiling caused by heating liquid-phase refrigerant, so that highly efficient defrosting can be performed.

Description

  The present invention relates to a refrigerator, and more particularly to a refrigerator with improved defrosting efficiency of a cooler.

  In general, when a refrigerator is used, frost adheres to the cooler, and cooling efficiency decreases. Therefore, it defrosts regularly.

  This defrosting is performed by heating a glass tube heater provided in the lower part of the cooler and heating the cooler with convection heat and radiant heat from the heater.

  However, the convection heat and radiant heat of the glass tube heater may increase the defrosting time due to the presence of the condensation water droplet prevention plate provided above the glass tube heater and the difficulty of hot air reaching the top of the cooler. There has been a problem of increasing the power consumption and increasing the power consumption.

  Therefore, in some conventional refrigerators, the lower refrigerant pipe located near the glass tube heater of the cooler is directly connected to the upper refrigerant pipe located at the upper portion of the cooler, and the high-temperature refrigerant in the lower refrigerant pipe heated by the glass tube heater. Is sent to the upper refrigerant pipe to increase the defrosting efficiency at the upper part of the cooler (see, for example, Patent Document 1).

  FIG. 13 shows a cooler 100 described in Patent Document 1, in which a refrigerant inlet pipe 101 from a condenser is connected to a lower refrigerant pipe 103 in the vicinity of a glass tube heater 102 for defrosting, and the lower cooling pipe 103 is connected to a connecting pipe. 104 is connected to the upper cooling pipe 105 of the cooler.

JP-A-7-190598

  In the cooler described in Patent Document 1, the high-temperature refrigerant in the lower refrigerant pipe 103 heated by the glass tube heater 102 for defrosting rises to the upper pipe 105 through the connection pipe, and the upper part of the cooler 100 is Heat is also heated from the inside of the pipe by the high-temperature refrigerant, and the defrosting time is shortened by heat transfer heating by this refrigerant.

  The present invention further improves the efficiency of such defrosting and provides a refrigerator having a much higher defrosting efficiency.

  In order to further improve the conventional defrosting efficiency, the present invention includes a cooler including a refrigerant pipe and plate fins in which a straight pipe part and a curved pipe part are continuously formed in a plurality of rows in the vertical direction, A blower forcibly circulating cool air generated by a cooler, a defrost heater disposed below the cooler, a cooling chamber containing the cooler, the blower and the defrost heater, and the defrost heater A controller that controls energization, and the controller starts energization of the defrost heater after a predetermined time has elapsed since the compressor was stopped.

  As a result, during the defrosting operation, in addition to the defrosting by radiation and convection heat from the defrosting heater, the high-temperature refrigerant in the lower refrigerant pipe heated by the defrosting heater flows into the upper refrigerant pipe and the cooler is also provided from the inside of the pipe. Since the defrosting of the upper part is performed, the defrosting time can be shortened and the heating by the defrosting heater is started after a predetermined time has elapsed since the compressor is stopped. In the refrigerant pipe, the gas-phase refrigerant is replaced with the liquid-phase refrigerant, and the ratio of the liquid-phase refrigerant increases. It flows into the pipe and heats the upper part of the heater. Therefore, efficient defrosting is possible.

  The present invention can defrost the upper part of the cooler not only by defrosting by radiation / convection heat from the defrosting heater but also by heat transfer of the heat of the refrigerant itself, and the heat transfer of the refrigerant evaporates the heated liquid refrigerant. Thus, the high-temperature refrigerant vapor rises in the pipe by buoyancy, efficiently transporting the heat of the refrigerant to the upper part of the cooler, and can be effectively performed, and a refrigerator having high defrosting efficiency can be obtained.

The longitudinal cross-sectional view of the refrigerator in Embodiment 1 of this invention The expanded longitudinal cross-sectional view which shows the cooling chamber of the refrigerator in the same Embodiment 1 The schematic which looked at the cooling chamber of the refrigerator in Embodiment 1 from the back Front view of refrigerator refrigerator in the first embodiment Side view of refrigerator cooler in the first embodiment The perspective view of the plate fin of the refrigerator cooler in Embodiment 1 Schematic explanatory drawing which shows the pipe arrangement of the refrigerator cooler in the first embodiment Control block diagram for controlling the defrosting heater of the refrigerator in the first embodiment Refrigeration control flow diagram of the refrigerator in the first embodiment The figure which shows the relationship between the pressure and temperature of the cooler after the compressor stop of the refrigerator in Embodiment 1, and low-temperature storage room temperature The schematic which looked at the cooling chamber of the refrigerator in Embodiment 2 from the back Schematic explanatory drawing which shows the pipe arrangement | sequence of the refrigerator cooler in Embodiment 3 Side view showing conventional refrigerator cooler and defrost heater

  According to a first aspect of the present invention, there is provided a cooler including a refrigerant pipe and plate fins in which a straight pipe part and a curved pipe part are continuously formed in a plurality of rows, and cold air generated by the cooler is forced. A fan to be circulated, a defrost heater disposed below the cooler, a cooling chamber containing the cooler, the blower and the defrost heater, and a control unit for controlling energization to the defrost heater, The said control part is set as the structure which starts electricity supply to a defrost heater after progress for the predetermined time which stopped the compressor.

  As a result, during the defrosting operation, in addition to the defrosting by radiation and convection heat from the defrosting heater, the high-temperature refrigerant in the lower refrigerant pipe heated by the defrosting heater flows into the upper refrigerant pipe and the cooler is also provided from the inside of the pipe. Since the defrosting of the upper part is performed, the defrosting time can be shortened and the heating by the defrosting heater is started after a predetermined time has elapsed since the compressor is stopped. In the refrigerant pipe, the gas-phase refrigerant is replaced with the liquid-phase refrigerant to increase the ratio of the liquid-phase refrigerant, and the heat transfer of the refrigerant is efficient because the heated liquid refrigerant evaporates and the high-temperature refrigerant vapor rises in the pipe by buoyancy It is possible to effectively carry the heat of the refrigerant to the upper part of the cooler and effectively perform the defrosting efficiency.

According to a second invention, in the first invention, the predetermined time is a time in which the compressor is stopped and the high pressure and the low pressure of the refrigeration cycle are balanced, and the high pressure and the low pressure of the refrigeration cycle are balanced. The inside of the lower refrigerant pipe becomes a refrigerant in a substantially liquid phase state, heat transfer to the upper refrigerant pipe becomes more efficient, and the defrosting efficiency can be further improved.

  According to a third invention, in the first or second invention, the low temperature storage room and a low temperature storage room temperature detecting means for detecting the temperature in the low temperature storage room, and a cooler temperature detecting means for detecting the temperature of the cooler are provided. The control means is configured to control the predetermined time based on the low temperature storage chamber temperature detection means and the cooler temperature detection means, and depending on the temperatures detected by the low temperature storage chamber temperature detection means and the cooler temperature detection means. Providing a refrigerator with high defrosting efficiency with an inexpensive configuration that can indirectly control the balance between the high pressure and low pressure of the refrigeration cycle and control energization to the defrost heater, without using an expensive pressure detector or the like. it can.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a longitudinal sectional view of a refrigerator according to Embodiment 1 of the present invention, FIG. 2 is an enlarged longitudinal sectional view showing a cooling chamber of the refrigerator according to Embodiment 1, and FIG. 3 is a cooling chamber of the refrigerator according to Embodiment 1. FIG. 4 is a front view of the refrigerator cooler in the first embodiment, FIG. 5 is a side view of the refrigerator cooler in the first embodiment, and FIG. 6 is the first embodiment. 7 is a perspective view of the plate fins of the refrigerator cooler in FIG. 7, FIG. 7 is an explanation showing the pipe arrangement of the refrigerator cooler in the first embodiment, and FIG. 8 is a control for controlling the defrosting heater of the refrigerator in the first embodiment. FIG. 9 is a flowchart for controlling the defrosting of the refrigerator according to the first embodiment. FIG. 10 is a diagram showing the relationship between the pressure and temperature of the refrigerator after the compressor stop of the refrigerator according to the first embodiment and the temperature of the cold storage room. FIG.

  1 to 10, a heat insulating box 31 of a refrigerator 30 is mainly composed of an outer box 32 using a steel plate and an inner box 33 formed of a resin such as ABS. Filled with a foam insulation material 34 such as foamed urethane.

  The inside of the heat insulation box 31 is divided into a plurality of storage rooms. A refrigeration room 35 is arranged at the top, a vegetable room 36 is arranged at the bottom of the refrigeration room 35, and a freezing room 37 is arranged at the bottom.

  A refrigerator compartment door 38 is opened at the front opening of the refrigerator compartment 35, a vegetable compartment door 39 is opened at the front opening of the vegetable compartment 36, and a freezer compartment door 40 is opened and closed at the front opening of the freezer compartment 37. It is provided as possible.

  The refrigerated room 35 is normally set to 1 ° C to 5 ° C at the lower limit of the temperature at which it does not freeze for refrigerated storage, and the vegetable room 36 is configured to be set to 3 to 8 ° C. It has become. The freezer compartment 37 is set in a freezing temperature zone and is usually set at −22 ° C. to −15 ° C. for frozen storage, but for example, −30 ° C. or −25 ° C. to improve the frozen storage state. It may be set at a low temperature, and it is a low-temperature storage room.

  The vegetable compartment 36 and the freezer compartment 37 are partitioned vertically by a first partition wall 41 that is a partition wall, and the refrigerator compartment 35 and the vegetable compartment 36 are partitioned vertically by a second partition wall 42 that is a partition wall.

Further, a cooling chamber 43 for generating cold air is provided on the back surface of the freezing chamber 37 serving as a low-temperature storage chamber, and a cooler 44 is provided inside. The cooling chamber 43 is insulated from the freezing chamber 37 by a vertical partition wall 45. A blower 46 that forcibly blows cool air generated above the cooler 44 is disposed, and a defrost heater 47 that defrosts frost and ice adhering to the cooler 44 is provided below the cooler 44. Yes. Furthermore, a drain pan 48 for receiving defrost water generated at the time of defrosting, a drain pipe 49 penetrating from the deepest part to the outside of the warehouse are configured at the lower part, and the evaporating dish 50 is installed outside the warehouse on the downstream side. .

  The defrost heater 47 is specifically a glass tube heater made of glass, and in particular when the refrigerant is a hydrocarbon-based refrigerant gas, it is a double glass tube heater in which glass tubes are formed in double for explosion protection. ing.

  The drain pan 48 constitutes a part of the bottom surface and the back surface of the cooling chamber 43. The bottom surface is configured to have the lowest connection portion with the drain pipe 49 in order to collect the defrost water in the drain pipe 49, and is farthest from the defrost heater 47 at the connection portion with the drain pipe 49 (distance L). It will be. The back surface rises to a height that exceeds the height at which the amount of water stored in the drain pan 48 can be secured, and the angle between the bottom surface and the back surface is a gently curved surface.

  The vertical partition wall 45 includes a front partition wall 45 a that forms the outer shell of the freezing chamber 37 and a rear partition wall 45 b that forms the outer shell of the cooling chamber 43. A space between the front partition wall 45a and the rear partition wall 45b is a distribution air passage 51 that branches cold air toward each storage chamber.

  The front partition wall 45 a has a freezer compartment discharge port 52 on the upper side, and communicates the distribution air passage 51 and the freezer compartment 37. There is a freezer return air passage 53 protruding downward from the freezer compartment 37 side, and the return cold air from the freezer compartment 37 is introduced into the cooling chamber 43 through an inlet 53a provided in front of the freezer return air passage 53.

  The distribution air passage 51 is also connected to a high temperature discharge air passage 54 provided in the first partition wall 41. Further, the high temperature discharge air passage 54 is connected to the refrigerator compartment 35 and the vegetable compartment 36.

  The rear partition wall 45 b includes a blower 46 on the upper side, and has a rib 55 that partitions the freezer return air passage 53 and the cooling chamber 43 on the lower side. A region surrounded by the freezing chamber return air passage 53 by the rib 55 and the drain pan 48 is a low temperature suction port 56, which is located at the lower part of the front surface of the cooling chamber 43 and communicates the freezing chamber return air passage 53 and the cooling chamber 43. ing.

  The bottom surface of the freezing chamber return air passage 53 is configured as a continuation of the bottom surface of the cooling chamber 43 by a part of the drain pan 48. The drain pan 48 starts from the lower end of the inlet 53a, passes through the lower end of the low-temperature suction port 56, inclines downward to the drain pipe 49, and then gradually turns upward to connect to the back surface of the cooling chamber 43.

  A high-temperature return air passage 57 is disposed on the back surface of the cooler 44. The high temperature return air passage 57 passes through the first partition wall 41 and the second partition wall 42 and communicates with the vegetable compartment 36 and the refrigerator compartment 35 which are high-temperature storage rooms, respectively, and cools the refrigerator compartment 35 and the vegetable compartment 36. The chilled air joins in the high-temperature return air passage 57. The high temperature return air passage 57 includes a high temperature suction port 58 that communicates with the cooling chamber 43 below. As is clear from FIG. 2, the high temperature suction port 58 is configured in the vicinity of the lower portion of the back surface of the cooler 44 and at a position higher than the low temperature suction port 56.

  The cooler 44 includes a refrigerant pipe 201 through which the refrigerant flows and a plurality of plate fins 202 arranged at predetermined intervals.

  Refrigerant pipe 201 is a single pipe made of aluminum or aluminum alloy, in which a straight pipe portion and a curved pipe portion are continuous, and are arranged in a meandering manner so that there are a plurality of pipes in row (left / right) direction X and step (up / down) direction Y. It is a serpentine pipe that is bent into a single shape, and forms one refrigerant flow path without using a connecting pipe that forms a curved pipe portion.

And the straight pipe part of the refrigerant | coolant pipe 201 has become the structure closely_contact | adhered to the plate fin 202, when the curved pipe part of the refrigerant | coolant pipe 201 penetrates the long hole 203 formed in the plate fin 202. FIG.

  The long hole 203 has a rectangular portion and a circular arc portion, and is formed in a long hole shape in which the circular arc portions are continuously formed on both short sides of the rectangular portion. Further, the arc part is provided with an edge-shaped arc part collar 203a for tightly fixing to the straight pipe part of the refrigerant pipe 201, and the edge part is formed substantially vertically at both ends in the longitudinal direction of the rectangular part. A rectangular portion collar 203b is provided.

  In the cooling chamber 43, the cooler 44 is installed such that the rectangular collar 203b is inclined downward toward the back of the refrigerator.

  Here, as shown in FIG. 4, the refrigerant pipe 201 of the cooler connects the refrigerant inlet pipe 201a from the condenser and capillary tube (not shown) to the lower refrigerant pipe 201b and connects the refrigerant inlet 201c to the cooler 44. As the bottom of the. In this embodiment, the front row A (see FIG. 5) is formed by meandering from the refrigerant inlet portion 201c to the upper portion of the cooler 44 by bending in the width direction of the refrigerator. The rear row B is configured to meander to the lower part to form a rear row B, and the end of the rear row B is raised to form the refrigerant outlet pipe 201d.

  On the other hand, the cooling chamber 43 containing the cooler 44 is provided with a bypass air passage 60 at a portion facing the refrigerant pipe row in the front row A connected to the refrigerant inlet portion 201c to which the refrigerant inlet pipe 201a is connected. That is, in this embodiment, the bypass air passage 60 is provided on the front side of the cooler 44 as shown in FIG. 2, and the refrigerant inlet portion 201 c is a low temperature suction port located on the side facing the bypass air passage 60. 56 is provided in the vicinity of one end.

  FIG. 8 is a control block diagram for controlling the defrosting heater 47. The control unit 63 for controlling the compressor 61, the blower 46, and the cool air damper 62 for controlling the cool air supply is operated every time the refrigerator is operated for a predetermined time, for example. The compressor 61 and the blower 46 are periodically stopped and the defrost heater 47 is energized to perform a defrost operation. In this embodiment, the control unit 63 includes a low-temperature storage chamber temperature detection unit 64 that detects the temperature of the freezing chamber 37 serving as the low-temperature storage chamber, and a cooler temperature detection unit 65 that detects the temperature of the cooler 44. The defrosting heater 47 is controlled based on the output of the defrosting operation to stop the defrosting operation.

  About the refrigerator comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the cooling operation will be described. A part of the cool air generated by the cooler 44 in the cooling chamber 43 is forcibly blown forward by the blower 46 in the distribution air passage 51. The freezer compartment 37 is cooled by the cold air discharged from the freezer compartment discharge port 52, and the cold air passes from the low temperature suction port 56 to the lower part of the cooler 44 via the freezer return air passage 53 provided at the lower part of the vertical partition wall 45. Then, the heat is exchanged in the cooler 44, and fresh cold air is again circulated by the blower 46. The freezer compartment 37 is cooled to an appropriate temperature based on the detected temperature from the low temperature storage compartment temperature detecting means 64.

  Further, the cold air discharged upward in the distribution air passage 51 is discharged to the refrigerator compartment 35 and the vegetable compartment 36 through the high temperature discharge air passage 54 in the first partition wall 41. The circulated cold air becomes the air in the refrigerator compartment 35 and the vegetable compartment 36 and the humid air contained in the stored product, passes through the high temperature return air passage 57 and is led to the lower part of the cooler 44 through the high temperature suction port 58. Heat exchange with the cooler 44 and dehumidification are performed, and fresh cool air is forcibly blown by the blower again.

Thereby, even if the refrigerator compartment 35 and the vegetable compartment 36 are in the position away from the cooler 44, the air can be forcedly circulated by the blower 46 to cool the storage compartment to the set temperature.

  When each chamber is cooled in this manner, frost adheres to the cooler 44 and grows. This frost is liquefied by the condenser, and the temperature of the refrigerant inlet 201c at the lower part of the cooler 44 and the lower refrigerant pipe 201b formed in the lower part of the cooler 44 enters the cooler 44. Easy to adhere to. At the same time, a part of the returned cool air from the high temperature suction port 58 and the low temperature suction port 56 passes through the refrigerant pipe row portion on the cooler front row A side facing the bypass air passage 60 from the bypass air passage 60. Therefore, a large amount of frost is likely to adhere to the refrigerant pipe row A side facing the bypass air passage 60. That is, the cooler 44 has a relatively large amount of frost formation on the lower part and the front part of the cooler.

  As described above, frost adheres to the cooler 44 and grows. Therefore, the control unit 63 performs the defrosting operation every time a predetermined time elapses.

  Hereinafter, the defrosting operation will be described using the control flow of FIG.

  When the cooling operation continues for a predetermined time, the control unit 63 first stops the compressor 61 and the blower 46 in step S1, and closes the cold damper 62 if it is in the open state in step S2. In this state, the pressure in the condenser and the cooler 44 in the refrigeration cycle starts to balance.

  Next, in step S3, the control unit 63 confirms that a predetermined time has elapsed from the stop of the compressor 61, and keeps waiting until the predetermined time has elapsed. By this standby, the pressure of the condenser and the cooler 44 is balanced, and during that time, the high-temperature refrigerant from the condenser flows through the capillary tube into the low-temperature cooler 44 in a gas-liquid two-phase state. The liquid refrigerant stays in the lower part due to gravity while partially condensing in the process.

  That is, by waiting for a predetermined time, the high-pressure liquid-phase refrigerant enters the refrigerant inlet 201c at the lower part of the cooler 44 via the refrigerant inlet pipe 201a, and there is sufficient liquid in the lower refrigerant pipe 201b connected to the refrigerant inlet 201c. The refrigerant can stay.

  In this state, the control unit 63 energizes the defrost heater 47 in step S4 and starts defrosting. When the defrost heater 47 is energized, the defrost heater 47 generates heat, the heat becomes radiation and convection heat to heat the cooler 44 above, and a part of the convection heat rises up the bypass air passage 60. The upper part of the cooler 44 is efficiently heated, and the frost adhering to the cooler 44 is defrosted.

  At this time, the temperature of the lower refrigerant pipe 201b of the cooler 44 rises in a short time due to the heating by the defrost heater 47, and the heated liquid refrigerant in the lower refrigerant pipe 201b evaporates, and the high-temperature refrigerant vapor is buoyant. Thus, the inside of the pipe is raised to reach the upper part of the cooler 44, and the upper part of the cooler 44 is also heated from the inside of the pipe. Therefore, the upper part of the cooler 44 is heated by the refrigerant from the inside of the pipe together with the radiation and convection heat from the defrost heater 47. Therefore, the upper part of the cooler 44 that is hard to reach the radiation and convection heat is efficiently defrosted in a short time. be able to.

  Further, the refrigerant rising from the lower refrigerant pipe 201b to the upper part of the cooler rises through the refrigerant pipe front row A on the front surface of the cooler connected to the lower refrigerant pipe 201b, so that the rising refrigerant also heats the refrigerant pipe front row A. It will be. That is, the refrigerant that heats the upper part of the cooler 44 from the inside of the pipe is also effectively used for defrosting on the refrigerant pipe front row A side on the front side of the cooler. As a result, similarly to the upper part of the cooler 44, the cooler front surface portion to which a relatively large amount of frost is attached can be efficiently defrosted in a shorter time than in the past.

  Furthermore, in this embodiment, at the start of the defrosting operation, the compressor 61 and the blower 46 are stopped, and then the standby state is established without performing the defrosting operation for a predetermined time. After the refrigerant is retained, the heated liquid refrigerant can be efficiently raised to the upper part of the cooler 44.

  That is, when the defrosting heater 47 is energized simultaneously with the stop of the compressor 61 and the blower 46 and the defrosting operation is started, the refrigerant in the lower refrigerant pipe 201b remains in a gas phase state and is heated by the defrosting heater 47. The refrigerant whose temperature has been increased does not efficiently rise to the upper part of the cooler 44. However, if the compressor is stopped for a predetermined time as in the present embodiment, the pressure between the condenser and the cooler is balanced during that time, and the gas-phase refrigerant in the lower refrigerant pipe 201b is caused by this pressure balance. The ratio of the liquid-phase refrigerant is increased by replacing the liquid-phase refrigerant from the evaporator, and the heated liquid refrigerant generated by heating the liquid-phase refrigerant at which the ratio is increased evaporates, and the high-temperature refrigerant vapor is buoyant. The heat of the refrigerant can be efficiently transported to the upper portion of the cooler 44 by ascending the pipe and efficient heating becomes possible.

  Here, the predetermined time when the refrigerant in the lower refrigerant pipe 201b of the cooler 44 is replaced with the liquid phase refrigerant is a time when the compressor 61 is stopped and the high pressure and low pressure of the refrigeration cycle are balanced as described above. The pressure balance may be detected by setting the time until the pressure is balanced as a predetermined time, but the pressure detector is expensive.

  Therefore, in this embodiment, the pressure balance is indirectly detected from the temperature of the cooler 44 and the temperature of the freezing chamber 37 which is a low temperature storage chamber, and a predetermined time is detected.

  FIG. 10 is a diagram showing the relationship between the pressure and temperature of the cooler 44 from the time when the compressor 61 is stopped, and the temperature of the low temperature storage chamber. The cooler 44 is pressurized between the compressor 61 and the condenser. In the meantime, the high-temperature liquid refrigerant in the condenser enters the refrigerant inlet 201c below the cooler 44 via the refrigerant inlet pipe 201a and enters the refrigerant inlet 201c. In the connected lower refrigerant pipe 201b, the gas-phase refrigerant at the beginning of the compressor stop is replaced with the liquid-phase refrigerant, and the ratio of the liquid-phase refrigerant increases.

  The point X at which the pressure of the cooler 44 and the condenser begins to balance begins to saturate as indicated by the temperature of the cooler 44, and the pressure balance is indirectly detected by detecting the saturating of the temperature of the cooler 44. can do. Alternatively, the detection is performed slightly earlier, but since the temperature of the cooler 44 exceeds the temperature of the low temperature storage chamber before the pressure is balanced, the detection can be performed indirectly by detecting the time Z.

  In this embodiment, the temperature of the cooler 44 is detected by the cooler temperature detecting means 65, the temperature of the freezer compartment 37, which is a low temperature storage room, is detected by the low temperature storage room temperature detecting means 64, and the temperature of the cooler 44 is low. The predetermined time is defined as a predetermined time after the temperature of the storage room is exceeded, and when the predetermined time is exceeded, the defrost heater 47 is energized to start defrosting. Therefore, it is not necessary to use an expensive pressure detector for detecting the pressure of the cooler 44 or the condenser, and it can be provided at a low cost.

  Further, in this embodiment, although omitted in the description of the above configuration, a second bypass air passage 66 is also provided on the back surface of the cooling chamber 43 as is apparent from FIG. Since the convective heat from 47 flows to the upper part of the cooler 44 through the second bypass air passage 66 together with the front bypass air passage 60, the defrosting efficiency by the convection heat is further improved.

When the defrosting is performed in this way and the removal of the frost adhering to the heater is completed, the cooler 4
The temperature of 4 begins to rise. This temperature rise is detected by the cooler temperature detecting means 65, and when this temperature reaches a predetermined temperature, the control unit 63 detects this in step S5, and in step S6, the energization to the defrost heater 47 is stopped and removed. End frost operation.

  Although the defrosting is performed as described above, the refrigerator of the present embodiment has a configuration in which the low temperature suction port 56 is provided on the front surface of the cooling chamber 43 and the high temperature suction port 58 is provided on the rear surface of the cooling chamber 43. In addition, it is possible to achieve uniform frost formation on the cooler 44 during the cooling operation, and by providing the high temperature suction port 58 on the back surface of the cooling chamber 43, the high temperature suction port 58 can be designed to be wide. Uniform frost formation in the left-right direction can also be achieved. Further, since the high temperature storage chamber such as the refrigerator compartment 35 is at the top and the high temperature return air passage 57 connected to the high temperature storage chamber 57 is located on the back of the cooling chamber 43, heat loss from the cooling chamber 43 to the outside can be reduced. .

  Further, since the bypass air passage 60 is provided on the front side of the cooling chamber 43, the bypass air passage 60 can maintain the return cold air flowing therein by the freezer compartment 37 positioned in front of the bypass air passage 60 at a low temperature. Energy saving can be achieved by preventing the decrease.

  Although not shown, in the refrigerator in which the low temperature suction port 56 is provided on the front surface of the cooling chamber 43 and the high temperature suction port 58 is provided on the back surface of the cooling chamber 43, the refrigerant inlet 201c of the cooler 44 has a cooling chamber. The rear refrigerant pipe row B, which is located in the lower portion near the high-temperature suction port 58 on the rear surface of 43 and is connected to the refrigerant inlet portion 201c, may be provided so as to face the second bypass air passage 66.

  By adopting such a configuration, relatively high temperature and humidity cold air from the high temperature suction port 58 opened at the lower back of the cooling chamber 43 flows through the second bypass air passage 66, so that the second bypass More frost adheres to the rear row of refrigerant pipes facing the air passage 66 than when low-temperature cold air from the freezer compartment passes. Therefore, the present method of defrosting the frost in the refrigerant pipe row portion by heat conveyance of the refrigerant itself is effective, and the defrosting effect is higher. In addition, since the second bypass air passage 66 is located on the back of the cooling chamber 43, the influence of heat on the freezer compartment 37 side due to convective heat from the defrost heater 47 flowing in the second bypass air passage 66 is reduced during defrosting. Can also be more effective.

  In the refrigerator according to the first embodiment, the low-temperature suction port 56 from the freezing chamber 37 serving as the low-temperature storage chamber is in front of the cooling chamber 43, and the high-temperature suction port 58 from the refrigerator compartment 35 serving as the high-temperature storage chamber is the cooling chamber. 43 The low-temperature suction port 56 is provided on the back surface and is positioned below the high-temperature suction port 58, so that the freezing room return cold air having a large backward speed and the high temperature return cold air having a large forward speed are vertically moved. By shifting, it is possible to suppress mutual interference and increase the amount of air circulating in the cabinet, so that the cooling capacity can be improved.

  Further, the drain pan 48 constituting the bottom surface of the cooling chamber 43 has a shape inclined downward from the low temperature suction port 56 to the drain pipe 49, so that the freezing chamber return cold air flows downward along the drain pan 48 and along the rear surface. Since the speed of the freezing chamber return cold air is directed upward in front of the high temperature suction port 58 and can smoothly merge with the high temperature return cold air, the air volume can be increased and the cooling capacity can be improved.

  Moreover, in the cooling chamber 43, the cooler 44 is installed so that the rectangular collar 203b is inclined downward toward the refrigerator back surface, so that the merged cold air has a vertically upward component from the back side of the cooler 44. The main portion of the cool air that has rushed in flows along the rectangular collar 203 b of the cooler 44 and is guided to the front surface of the cooler 44. Thereby, the amount of heat exchange can be increased by passing the cool air through the entire cooler 44, and the cooling capacity can be improved.

(Embodiment 2)
FIG. 11 shows a cooling chamber of the refrigerator in the second embodiment, and is a schematic view of the cooling chamber as viewed from the front.

  In the refrigerator of the second embodiment, the high temperature return air passage 57 and the high temperature suction port 58 described in the first embodiment are provided on the side of the cooling chamber 43, and the low temperature suction port 56 is provided on the front surface of the cooling chamber 43. In addition, the refrigerant inlet portion 201 c of the cooler 44 is a side portion of the cooling chamber 43 opposite to the high temperature suction port 58.

  Other configurations are the same as those of the first embodiment, and the same configurations and the same functional parts are denoted by the same reference numerals and the description thereof is omitted.

  In the second embodiment, since the low temperature suction port 56 is provided on the front surface of the cooling chamber 43 and the high temperature suction port 58 is provided on the side surface of the cooling chamber 43, uniform frost formation on the cooler 44 during the cooling operation is achieved. Can do. Particularly in the second embodiment, since the refrigerant inlet 201c is provided on the side surface opposite to the high temperature suction port 58, the amount of frost formation can be made more uniform. That is, since the return cold air from the high temperature suction port 58 has a high temperature and humidity as described above, the amount of frost formation increases in the lower part of the side surface of the cooler near the high temperature suction port 58. On the other hand, the refrigerant inlet portion 201c provided at the lower part of the side surface of the cooler opposite to the high temperature suction port 58 is strongly cooled because the low temperature refrigerant from the condenser first enters and the amount of frost formation increases. As a result, the amount of frost formation at the lower part of the cooler 44 is substantially uniform on the left and right sides, and the defrosting operation can be performed to remove the frost almost evenly on the left and right, thereby enabling efficient defrosting.

  Further, by providing the high-temperature suction port 58 on the side surface of the cooling chamber 43, the depth dimension of the cooling chamber 43 can be reduced, space saving is possible, or if the depth dimension of the cooling chamber 43 is not reduced, cooling is performed. The depth of the vessel 44 can be increased and the cooling capacity can be increased.

  Other functions and effects are the same as those of the first embodiment, and a description thereof will be omitted.

  In the second embodiment, although not shown, it is conceivable to provide the refrigerant inlet 201c on the same side as the high temperature suction port 58 provided on the side of the cooling chamber 43.

  In this case, although the amount of frost formation on the cooler 44 cannot be made uniform, the refrigerant heat generated at the time of defrosting using the refrigerant inlet pipe 201a communicating from the upper side to the lower side connected to the refrigerant inlet portion 201c. The conveyance also enables defrosting in the high-temperature return air passage 57 in the vicinity of the refrigerant inlet pipe 201a, thereby improving the reliability.

(Embodiment 3)
FIG. 12 shows a refrigerator 44 of the refrigerator in the third embodiment, and is a schematic explanatory view of the cooler 44 viewed from the side.

  The refrigerator cooler 44 of the third embodiment has three rows of refrigerant pipes 201, ie, a front row A, a middle row C, and a rear row B. The refrigerant pipe length is increased to increase the cooling effect. is there.

  Other configurations and effects are the same as those in the first or second embodiment, and a description thereof will be omitted.

The plurality of storage rooms provided in the heat insulating box 31 of the refrigerator described in each of the above embodiments are a refrigeration room 35 at the top, a vegetable room 36 at the bottom of the refrigeration room 35, and a freezing room at the bottom. However, the arrangement is not limited to the arrangement, and for example, the freezing room 37 may be arranged in the lower part of the refrigerator room 35 and the vegetable room may be arranged in the lower part. It is. In this case, the high temperature suction port 58 from the refrigerator compartment 35 and the high temperature suction port 58 from the vegetable compartment 36 are provided separately, but these may be disposed adjacent to each other on the back surface of the cooler 44, for example.

  In the present invention, the upper part of the cooler can be defrosted not only by defrosting by radiation / convection heat from the defrosting heater but also by heat transfer of heat of the refrigerant itself. As a result, it can be a refrigerator with high defrosting efficiency, and can be widely applied not only to household refrigerators but also to commercial refrigerators and showcases.

30 Refrigerator 35 Refrigerated room (high temperature storage room)
36 Vegetable room (high temperature storage room)
37 Freezer room (cold storage room)
43 Cooling chamber 44 Cooler 46 Blower 47 Defrost heater 48 Drain pan (cooling chamber bottom)
53 Freezer return air passage 53a Entrance 56 Low temperature intake port 57 High temperature return air passage 58 High temperature intake port 60 Bypass air passage 61 Compressor 62 Cold air damper 63 Control unit 64 Low temperature storage chamber temperature detection means 65 Cooler temperature detection means 66 Second Bypass air passage 201 Refrigerant pipe 201a Refrigerant inlet pipe 201b Lower refrigerant pipe 201c Refrigerant inlet part 201d Refrigerant outlet pipe 202 Plate fin

Claims (3)

A cooler comprising a refrigerant pipe and plate fins formed in a plurality of rows of straight pipe parts and curved pipe parts continuously in the vertical direction, and a blower for forcibly circulating cold air generated by the cooler; A defrost heater disposed below the cooler; a cooling chamber containing the cooler, a blower, and a defrost heater; and a control unit that controls energization of the defrost heater, wherein the control unit is a compressor The refrigerator which made the structure which starts electricity supply to a defrosting heater after stopping predetermined time progress. The refrigerator according to claim 1, wherein the predetermined time for starting energization of the defrosting heater is a time during which the compressor is stopped and the high pressure and the low pressure of the refrigeration cycle are balanced. A low temperature storage room and a low temperature storage room temperature detecting means for detecting a temperature in the low temperature storage room; and a cooler temperature detecting means for detecting a temperature of the cooler, wherein the control means is the low temperature storage room temperature detecting means and the cooler. The refrigerator according to claim 1 or 2, wherein the predetermined time is controlled based on temperature detection means.

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