JP6101926B2 - refrigerator - Google Patents

Description

  The present invention relates to a refrigerator that has a capillary tube as an expansion mechanism of a refrigeration cycle and adjusts the amount of squeezing according to load conditions.

  From the viewpoint of energy saving, in the refrigeration cycle of a household refrigerator, an inverter compressor whose rotation speed is variable according to load conditions is used. At this time, under high load conditions, the inverter compressor is rotated at a high speed to increase the refrigerant circulation rate to increase the capacity. Under normal load conditions, the inverter compressor is rotated at a low speed to reduce the refrigerant circulation rate. To improve efficiency. However, when a capillary tube is used as the expansion mechanism of the refrigeration cycle, if the throttle amount of the capillary tube is designed according to the refrigerant circulation amount under the high load condition, the efficiency will be reduced more slowly than the proper throttle amount under the normal load condition. In addition, if the amount of restriction of the capillary tube is designed in accordance with the amount of refrigerant circulation under normal load conditions, the ability to tighten is reduced more than the proper amount of restriction under high load conditions.

  Then, in order to adjust the refrigerant | coolant circulation amount according to the load conditions of a refrigerator, the refrigerator which switches and uses several capillary tubes is proposed (for example, refer patent document 1).

  Hereinafter, a conventional refrigerator will be described with reference to the drawings.

  FIG. 6 is a configuration diagram of a refrigeration cycle of a conventional refrigerator.

  In FIG. 6, 60 is a compressor, 61 is a condenser, 62 is a freezer compartment evaporator, 63 is a refrigerator compartment evaporator, 64 is a freezer compartment fan, 65 is a refrigerator compartment fan, 66 is an accumulator, and 67 is a check valve. is there. 68 is a flow path switching valve for switching the flow path from the condenser 61 to the freezer compartment evaporator 62 or the refrigerator compartment evaporator 63, 69 is a freezer compartment capillary tube, 70 is a refrigerator compartment capillary tube, and 71 is a refrigerator compartment auxiliary. A capillary tube 72 is an open / close valve that opens and closes the flow path to the refrigerator compartment auxiliary capillary tube 71.

  Here, the conventional refrigerator cools a freezer compartment (not shown) using the freezer evaporator 62 and cools the refrigerator compartment (not shown) using the refrigerator compartment evaporator 63. When supplying the refrigerant to the freezer compartment evaporator 62, the flow path switching valve 68 is switched so as to communicate with the freezer compartment evaporator 62 from the condenser 61 through the freezer compartment capillary tube 69, and the refrigerator compartment evaporator 63. When the refrigerant is supplied to the refrigerant, the flow path switching valve 68 is switched so as to communicate with the refrigerator compartment evaporator 63 from the condenser 61 via the refrigerator compartment capillary tube 70 or the refrigerator compartment auxiliary capillary tube 71.

  The operation of the conventional refrigerator configured as described above will be described below.

  The refrigerant discharged from the compressor 60 is radiated and liquefied by the condenser 61 and then supplied to the flow path switching valve 68. When the freezing room (not shown) needs to be cooled, the flow path switching valve 68 is switched, the pressure is reduced by the freezing room capillary tube 69, and the refrigerant is supplied to the freezing room evaporator 62 to be evaporated. At this time, the freezer compartment (not shown) is cooled by driving the freezer compartment fan 64. Further, the refrigerant circulation amount is excessive as compared with the load of the freezer compartment (not shown), and surplus refrigerant that could not be evaporated by the freezer evaporator 62 is stored in the accumulator 66.

On the other hand, when cooling of the refrigerator compartment (not shown) is necessary, the flow path switching valve 68 is switched,
The refrigerant is depressurized by the refrigerator compartment capillary tube 70 or the refrigerator compartment auxiliary capillary tube 71 and supplied to the refrigerator compartment evaporator 63 to evaporate. At this time, the refrigerator compartment (not shown) is cooled by driving the refrigerator compartment fan 65.

  Here, under normal load conditions in which the temperatures of the freezer compartment (not shown) and the refrigerator compartment (not shown) are relatively stable, the on-off valve 72 is closed when the refrigerator compartment (not shown) is cooled. No refrigerant is supplied to the refrigerator compartment auxiliary capillary tube 71, and only the refrigerator compartment capillary tube 70 is used. On the other hand, when the door is opened or closed and a large amount of high-temperature food is added to increase the temperature of the refrigerator compartment (not shown), the opening / closing valve 72 is opened when the refrigerator compartment (not shown) is cooled. Then, the refrigerant is supplied to both the refrigerator compartment auxiliary capillary tube 71 and the refrigerator compartment capillary tube 70.

  As a result, in a high load condition where the temperature of the refrigerating room (not shown) has increased, the refrigerant circulation amount to the refrigerating room evaporator 63 can be increased to increase the capacity. At this time, if the speed of the compressor 60 is increased in synchronism with the opening of the on-off valve 72, the capacity can be further increased. Further, if the throttle amount of the refrigeration chamber capillary tube 70 is designed in accordance with the normal load condition in which the on-off valve 72 is closed, the efficiency can be improved and the compression is performed in synchronization with the opening of the on-off valve 72. If the machine 60 is decelerated, higher efficiency can be achieved.

  In particular, the refrigerator compartment (not shown) has a higher set temperature than the freezer compartment (not shown), and the room temperature is low in summer, even though the load is small under normal load conditions where there is no door opening or closing or food input. Since there is a possibility that the amount of load under a high load condition in which a large amount of relatively high-temperature foods close to is charged is larger than that in a freezer compartment (not shown), the amount of refrigerant circulation can be reduced according to the load condition. It is important to adjust.

JP 2001-263902 A

  However, in the conventional refrigerator configuration, the refrigerator compartment auxiliary capillary tube 71 and the open / close valve 72 are necessary to adjust the throttle amount in cooling the refrigerator compartment, and the piping configuration becomes complicated.

  Further, in the conventional refrigerator configuration, the throttle amount adjustment is limited to two stages of opening / closing of the on-off valve 72, and finely copes with the refrigerant circulation amount change accompanying the rotation speed change of the compressor 60 which is normally switched to 3-6 stages. Can not do it.

  Therefore, it has been a problem to appropriately adjust the amount of squeezing according to the load condition of the refrigerator.

  The present invention solves the conventional problems, and by cooling the inlet-side non-heat exchange section of the capillary tube with the discharged cold air supplied to the refrigerator compartment, the capillary tube is squeezed particularly according to the load condition of the refrigerator compartment. The purpose is to adjust the amount automatically.

In order to solve the conventional problems, the refrigerator of the present invention includes a refrigeration cycle having at least a compressor, a condenser, a capillary tube, an evaporator, an evaporator fan, and a suction, a refrigerator compartment, and a freezer compartment. An internal heat exchanging portion that thermally couples the capillary tube and the suction to perform internal heat exchange of the refrigeration cycle, and the capillary tube
The non-heat exchanging portion upstream of the internal heat exchanging portion is cooled by cold air supplied to the refrigerating chamber by the evaporator fan .

As a result, when the refrigerator compartment is cooled, the capillary tube inlet side non-heat exchanging portion is simultaneously cooled to reduce the capillary tube throttling amount and increase the refrigerant circulation amount, thereby achieving higher performance. . This is to reduce the pressure loss of the capillary tube by cooling the inlet side non-heat exchanging part of the capillary tube, thereby suppressing the evaporation of the refrigerant passing through the inside and suppressing the increase in the dryness. . In particular, the non-heat exchange section on the inlet side of the capillary tube has a great effect of reducing pressure loss due to cooling because the change in dryness is large.

  In addition, the cooling operation time of the refrigerator compartment varies greatly depending on the load condition of the refrigerator, and especially when a large amount of relatively hot food near room temperature is thrown in the summer when the load condition is high, the cooling operation time of the refrigerator compartment increases. At the same time, the compressor and the fan are increased in speed to control the refrigeration system to have a higher capacity. At this time, the discharged cool air supplied to the refrigerating chamber becomes a low temperature with a higher air volume than usual, and promotes cooling of the inlet side non-heat exchange section of the capillary tube. As a result, it is possible to further increase the capacity by increasing the refrigerant circulation rate.

  On the other hand, under normal load conditions, the cooling operation time of the refrigerator compartment is short, and the cooling operation of the freezer room is the main. In this case, cooling of the inlet-side non-heat exchanging portion of the capillary tube is slow, and the original throttle amount of the capillary tube is maintained. As a result, if the amount of restriction of the capillary tube is designed in accordance with the refrigerant circulation amount under the normal load condition, it is possible to achieve high efficiency under the normal load condition and high performance under the high load condition.

  The refrigerator of the present invention is designed by cooling the capillary tube inlet-side non-heat exchanging portion with the discharge cold air supplied to the refrigeration chamber so that the capillary tube throttle amount is designed in accordance with the refrigerant circulation amount under normal load conditions. It is possible to achieve high efficiency under normal load conditions and high capacity under high load conditions.

The longitudinal cross-sectional view of the refrigerator in Embodiment 1 of this invention Cycle configuration diagram of refrigerator in Embodiment 1 of the present invention Schematic diagram of the front of the refrigerator in Embodiment 1 of the present invention The schematic diagram of the back surface of the refrigerator in Embodiment 1 of this invention Sectional drawing of the internal heat exchange part of the refrigerator in Embodiment 1 of this invention Cycle configuration diagram of a conventional refrigerator

In the first invention, the housing includes a refrigeration cycle having at least a compressor, a condenser, a capillary tube, an evaporator, an evaporator fan, and a suction, a refrigeration chamber, and a freezing chamber, and the internal heat of the refrigeration cycle In order to perform the exchange, an internal heat exchange unit that thermally couples the capillary tube and the suction is provided, and the non-heat exchange unit upstream of the internal heat exchange unit in the capillary tube is refrigerated by the evaporator fan. It is a refrigerator characterized by cooling with cold air supplied to a room.

  As a result, when the refrigerator compartment is cooled, the capillary tube inlet side non-heat exchanging portion is simultaneously cooled to reduce the capillary tube throttling amount and increase the refrigerant circulation amount, thereby achieving higher performance. .

  According to a second aspect of the present invention, there is provided a heat dissipating plate that is thermally coupled to a non-heat exchanging portion on the inlet side of an internal heat exchanging portion in a capillary tube and has a surface area 2 to 10 times that of the non-heat exchanging portion on the inlet side of the capillary tube. The refrigerator is characterized in that the heat dissipation plate is cooled by cold air supplied to a refrigerating chamber by the evaporator fan.

This improves the efficiency of heat exchange between the inlet-side non-heat exchange section of the capillary tube and the cold air supplied to the refrigerator compartment, thereby reducing the length of the inlet-side non-heat exchange section of the capillary tube. . If the length of the non-heat exchange part on the inlet side of the capillary tube is longer than necessary, the efficiency of the internal heat exchange is reduced, resulting in problems such as dew condensation due to a reduction in the temperature of the suction.

  3rd invention is a refrigerator provided with the suction and the fin which is formed in the pipe | tube of the said suction and expands the surface area in a pipe | tube 1.5 to 5 times.

  Thereby, by improving the efficiency of internal heat exchange, it is possible to suppress the temperature drop of the suction due to the temperature drop of the inlet side non-heat exchange part of the capillary tube.

  A fourth invention includes a plurality of dew-proof pipes and a switching valve for switching the dew-proof pipes, and uses all the dew-proof pipes at high loads and switches the switching valves at normal loads. It is a refrigerator characterized by selectively using only some of the dew-proof pipes.

  As a result, at the time of high load when the amount of capillary tube squeezing is reduced and the amount of refrigerant circulation is increased, a sufficient heat radiation amount can be secured by using all the above dew-proof pipes, and the capillary tube squeezing amount can be secured. During normal loads with increased amounts and reduced refrigerant circulation, only some of the dew-proof pipes can be used selectively to reduce the load caused by the dew-proof pipes and save energy. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 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 a cycle configuration diagram of the refrigerator according to Embodiment 1 of the present invention, and FIG. 3 is a schematic front view of the refrigerator according to Embodiment 1 of the present invention. 4 is a schematic view of the back surface of the refrigerator according to Embodiment 1 of the present invention, and FIG. 5 is a cross-sectional view of the internal heat exchange part of the refrigerator according to Embodiment 1 of the present invention.

  In FIG. 1, the refrigerator 11 includes a housing 12, a door 13, and legs 14 that support the housing 12, a lower machine room 15 provided in a lower portion of the housing 12, and a rear upper portion of the housing 12. An upper machine room 16 provided in the storage room, a refrigerating room 17 serving as a storage room arranged at the upper part of the casing 12, and a freezing room 18 arranged at the lower part of the casing 12 are formed.

  The refrigeration cycle includes a compressor 19 housed in the upper machine room 16, an evaporator 20 housed in the back side of the freezer room 18, and a main condenser having a large heat dissipation among the condensers housed in the lower machine room 15. 21.

  In addition, it has a partition wall 22 that partitions the lower machine room 15, a fan 23 that is attached to the partition wall 22 to air-cool the main condenser 21, an evaporating dish 24 that is housed on the back side of the lower machine room 15, and a bottom plate 25 of the lower machine room 15. . Here, the main condenser 21 is composed of a spiral fin tube in which a strip-shaped fin is wound around a refrigerant pipe having an inner diameter of about 4.5 mm.

  The lower machine chamber 15 includes a plurality of intake ports 26 provided in the bottom plate 25, a discharge port 27 provided on the back side of the lower machine chamber 15, a discharge port 27 of the lower machine chamber 15, and the upper machine chamber 16. A connecting air passage 28 is provided. Here, the lower machine chamber 15 is divided into two chambers by a partition wall 22, and a main condenser 21 is housed on the windward side of the fan 23 and an evaporating dish 24 is housed on the leeward side.

  In addition, an evaporator fan 38 that supplies the cool air of the evaporator 20 and a refrigerating room damper 39 that adjusts the supply of the cool air to the refrigerating room 17 are provided on the upper part of the evaporator 20. A refrigerating room cooling air passage 40, which is a passage for the cold air supplied to the refrigerating room 17 through the damper, is provided.

  2 to 5, as a condenser, in addition to the main condenser 21, a dew-proof pipe A <b> 30 disposed in the opening of the freezer compartment 18 as a sub-condenser that dissipates high-temperature heat in the refrigeration cycle, a housing 12 is provided with a dew-proof pipe B31 disposed on the back side.

  Further, a flow path switching valve 32 connecting the downstream side of the main condenser 21 with the dew-proof pipe A30 and the dew-proof pipe B31, a junction point 33 connecting the downstream side of the dew-proof pipe A30 and the downstream side of the dew-proof pipe B31, and a junction point A dryer 34 installed downstream of the dryer 33, a capillary tube 35 installed downstream of the dryer 34, and a suction 36 returning from the evaporator 20 to the compressor 19 are provided. Here, the capillary tube 35 and the suction 36 are thermally coupled via solder 41 in order to perform internal heat exchange. Further, the inlet-side non-heat exchanging portion 35a upstream from the internal heat exchanging portion of the capillary tube 35 is thermally coupled by a heat radiating plate 37 having an approximately five times surface area and an aluminum foil tape (not shown). The side non-heat exchanging portion 35 a and the heat radiating plate 37 are embedded in the wall surface of the refrigerator compartment cooling air passage 40 and exchange heat with the cold air flowing in the refrigerator compartment cooling air passage 40. In the first embodiment of the present invention, the heat radiating plate 37 having a surface area about 5 times that of the inlet-side non-heat exchanging portion 35a is used. However, the heat radiating plate 37 having a surface area of 2 to 10 times may be used. desirable. If it is less than 2 times, a sufficient heat dissipation effect cannot be obtained, and if it exceeds 10 times, the effect of increasing the heat radiation amount with respect to an increase in surface area can hardly be obtained.

  The dew-proof pipe A30 and the dew-proof pipe B31 are made of refrigerant pipes having an inner diameter of about 3.2 mm, and are thermally coupled to the outer surface of the housing 12.

  In FIG. 5, the fin 36a is formed in the pipe | tube of the suction 36, and the internal surface area of the pipe | tube of the suction 36 is expanded about 2 time compared with the smooth pipe. Thereby, the heat conduction of the refrigerant flowing in the suction 36 and the pipe is improved, and the efficiency of the internal heat exchange between the capillary tube 35 and the suction 36 is improved. In the first embodiment of the present invention, the fin 36a is formed so that the inner surface area of the suction 36 is about twice that of the smooth tube, but the fin 36a is formed in the range of 1.5 to 5 times. It is desirable. If it is less than 1.5 times, a sufficient effect of improving heat conduction cannot be obtained, and if it exceeds 5 times, the adverse effect of reducing the circulation rate due to an increase in pressure loss is greater than the effect of improving heat conduction.

  About the refrigerator in Embodiment 1 of this invention comprised as mentioned above, the operation | movement is demonstrated below.

  Under high load conditions, the flow path switching valve 32 is switched to open the connection to the dew-proof pipe A30 and open the connection to the dew-proof pipe B31, and drive the fan 23 in conjunction with the operation of the compressor 19. To do. By driving the fan 23, the main condenser 21 side of the lower machine chamber 15 partitioned by the partition wall 22 has a negative pressure, and external air is sucked from the plurality of intake ports 26, and the evaporating dish 24 side has a positive pressure. The air is discharged from the plurality of discharge ports 27 to the outside.

  On the other hand, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then the dew-proof pipe A 30 and the dew-proof pipe through the flow path switching valve 32. To B31. At this time, the pipe of the main condenser 21 is in an initial stage where the refrigerant condenses, and there is more gaseous refrigerant than the dew-proof pipe A30 and the dew-proof pipe B31, and the flow rate is relatively high. A pipe having an inner diameter larger than that of the dew-proof pipe B31, preferably a pipe having an inner diameter of 4 mm or more is preferably used.

  The refrigerant that has passed through the dew-proof pipe A30 dissipates heat and condenses outside through the housing 12 while warming the opening of the freezer compartment 18, and the refrigerant that has passed through the dew-proof pipe B31 passes through the back surface of the housing 12. While being heated, the heat is dissipated to the outside through the housing 12 and condensed. The liquid refrigerant that has passed through the dew-proof pipe A30 and the dew-proof pipe B31 is dehydrated by the dryer 34, depressurized by the capillary tube 35, and evaporated in the evaporator 20 while being circulated by the evaporator fan 38 and heat. After the replacement, the refrigerant passes through the suction 36 and is returned to the compressor 19 as a gaseous refrigerant. At this time, the gaseous refrigerant that recirculates in the suction 36 is heated to near room temperature while exchanging internal heat with the high-temperature refrigerant flowing in the capillary tube 35 via the solder 41.

  Here, when the temperature of the refrigerator compartment 17 rises, the refrigerator compartment damper 39 is opened, and the cold air generated by the evaporator 20 is supplied from the refrigerator compartment cooling air passage 40 to the refrigerator compartment 17 by the evaporator fan 38. At this time, the inlet side non-heat exchanging portion 35a of the capillary tube 35 is cooled by cooling the heat radiating plate 37 installed on the wall surface in the refrigerator compartment cooling air passage 40. As a result, it is possible to reduce the pressure loss of the capillary tube by suppressing the evaporation of the refrigerant passing through the inside and thereby suppressing the increase in the dryness, and to increase the circulation amount of the refrigerant and to improve the performance. it can.

  On the other hand, the cold air generated by the evaporator 20 is supplied to the freezer compartment 18 in parallel with the refrigerator compartment 17 by the evaporator fan 38. However, since the internal air that is returned to the evaporator 20 due to the load put into the refrigerator compartment 17 becomes relatively high for a long time, the temperature of the cold air generated in the evaporator 20 also rises, and the freezer compartment 18 is frozen. It remains to the extent that the upper temperature limit of −18 to −15 ° C. is maintained.

  When the refrigerator compartment 17 is sufficiently cooled and reaches a predetermined temperature, the refrigerator compartment damper 39 is closed, and the cold air generated by the evaporator 20 is supplied only to the freezer compartment 18 by the evaporator fan 38. At this time, the heat radiating plate 37 installed on the wall surface in the refrigerating room cooling air passage 40 is not cooled, the original throttle amount of the capillary tube 35 is maintained, and the refrigerant circulation amount is reduced. As a result, the evaporation temperature of the refrigerant in the evaporator 20 is lowered to −25 to −30 ° C., and the freezer compartment 18 can be cooled to about −20 ° C.

  As described above, under a high load condition, the heat radiation plate 37 is cooled in accordance with the cooling operation of the refrigerator compartment, so that the pressure loss of the capillary tube can be reduced, and the refrigerant circulation amount is increased to increase the capacity. Can be achieved.

  In addition, by flowing the refrigerant in parallel to the dew-proof pipe A30 and the dew-proof pipe B31, the heat radiation capacity can be increased, and the pressure loss caused by the dew-proof pipe can be reduced by reducing the refrigerant circulation amount per one. Can also be expected to be suppressed.

  Next, under normal conditions, the flow path switching valve 32 is switched to close the connection to the dew-proof pipe A30 and open the connection to the dew-proof pipe B31. At this time, the refrigerant discharged from the compressor 19 is condensed while leaving a part of the gas while exchanging heat with the outside air in the main condenser 21, and then dew-proofing as a sub-condenser via the flow path switching valve 32. It is supplied to the pipe B31. The refrigerant that has passed through the dew-proof pipe B31 dissipates heat through the housing 12 and condenses while warming the back surface of the housing 12.

On the other hand, the dew-proof pipe A30 into which the refrigerant does not flow from the flow path switching valve 32 does not radiate heat and eliminates the temperature difference from the surroundings. At this time, the high-pressure refrigerant flows from the junction 33, and the dew proof pipe A30 is almost filled with the liquid refrigerant. Thus, the liquid refrigerant does not move while staying in the dew-proof pipe A30 that is not used on the high-pressure side of the refrigeration cycle, and the total amount of refrigerant circulating in the refrigeration cycle is reduced. Therefore, when the dew-proof pipe A30 or the dew-proof pipe B31 is switched and not used, in order to suppress a decrease in the amount of refrigerant circulating in the refrigeration cycle, a pipe having a smaller inner diameter than that of the main condenser 21 is preferably used. It is preferable to use a pipe of less than 4 mm.

  The liquid refrigerant that has passed through the dew-proof pipe B31 is subjected to heat exchange with the internal air circulated by the evaporator fan 38 while being dehydrated by the dryer 34, depressurized by the capillary tube 35, and evaporated by the evaporator 20. Then, it passes through the suction 36 and returns to the compressor 19 as a gaseous refrigerant. At this time, the gaseous refrigerant that recirculates in the suction 36 is heated to near room temperature while exchanging internal heat with the high-temperature refrigerant flowing in the capillary tube 35 via the solder 41.

  Here, when the compressor 19 is started, the refrigerator compartment damper 39 is opened, and the cold air generated by the evaporator 20 is supplied from the refrigerator compartment cooling air passage 40 to the refrigerator compartment 17 by the evaporator fan 38. At this time, the inlet side non-heat exchanging portion 35a of the capillary tube 35 is cooled by cooling the heat radiating plate 37 installed on the wall surface in the refrigerator compartment cooling air passage 40. As a result, it is possible to reduce the pressure loss of the capillary tube by suppressing the evaporation of the refrigerant passing through the inside and thereby suppressing the increase in the dryness. The rising characteristic of the ability can be improved.

  And under normal load conditions, the refrigerator compartment 17 is immediately cooled sufficiently. When the refrigerator compartment 17 reaches a predetermined temperature, the refrigerator compartment damper 39 is closed, and the cool air generated by the evaporator 20 is supplied only to the freezer compartment 18 by the evaporator fan 38. At this time, the heat radiating plate 37 installed on the wall surface in the refrigerating room cooling air passage 40 is not cooled, the original throttle amount of the capillary tube 35 is maintained, and the refrigerant circulation amount is reduced. As a result, the evaporation temperature of the refrigerant in the evaporator 20 is lowered to −25 to −30 ° C., and the freezer compartment 18 can be cooled to about −20 ° C.

  As described above, under normal load conditions, it is possible to improve the rising characteristics of the refrigeration capacity when the compressor 19 is started, and to design the throttle amount of the capillary tube 35 in accordance with the refrigerant circulation amount under normal load conditions. Thus, high efficiency can be achieved under normal load conditions.

  Further, under normal load conditions, the dew-proof pipe A30 is not used, and the refrigerant is allowed to flow through the dew-proof pipe B31, so that the heat load caused by the dew-proof pipe A30 can be reduced to further increase the efficiency. it can.

  As described above, the refrigerator of the present invention cools the inlet-side non-heat exchanging portion 35a of the capillary tube 35 with the discharge cold air supplied to the refrigerator compartment 17, thereby reducing the amount of restriction of the capillary tube 35 and circulating the refrigerant. The capacity can be increased by increasing the amount. In particular, when a large amount of food having a relatively high temperature close to room temperature is introduced in summer, which is a high load condition, the cooling operation time of the refrigerator compartment 17 is increased, and the cooling of the inlet side non-heat exchange part 35a of the capillary tube 35 is promoted. By doing so, it is possible to increase the capacity more effectively according to the load of the refrigerator compartment 17.

  On the other hand, under normal load conditions, the cooling operation time of the refrigerator compartment 17 is short, and the cooling operation of the freezer compartment 18 is mainly performed. In this case, the cooling of the inlet-side non-heat exchanging portion 35a of the capillary tube 35 becomes slow, and the original throttle amount of the capillary tube 35 is maintained. As a result, if the amount of restriction of the capillary tube 35 is designed in accordance with the refrigerant circulation amount under the normal load condition, it is possible to achieve high efficiency under the normal load condition and high performance under the high load condition.

In the refrigerator according to the first embodiment of the present invention, the cooling amount of the heat radiating plate 37 under a high load condition is designed to be about 5% of the refrigeration capacity obtained by the evaporator 20. It is desirable to design the amount to 2 to 10% of the refrigeration capacity obtained with the evaporator 20. If the cooling amount is less than 2%, the effect of reducing the amount of restriction of the capillary tube 35 cannot be obtained.
If it exceeds%, there is a risk that the temperature of the suction 36 will decrease and condensation will occur. Since the suction 36 is heated to near room temperature by exchanging heat with the capillary tube 35 via the solder 41, if the cooling amount of the heat radiating plate 37 exceeds 10%, the temperature of the capillary tube 35 is lowered and the suction 36 and the suction are reduced. The heating of the gas refrigerant flowing through the interior 36 becomes insufficient.

  At this time, the fin 36a is formed in the pipe of the suction 36 to increase the internal surface area 1.5 to 5 times, thereby improving the efficiency of internal heat exchange and suppressing the temperature drop of the suction 36. If the cooling amount of the heat radiating plate 37 is 2 to 10%, the temperature after the internal heat exchange of the suction 36 can be maintained near room temperature regardless of the temperature drop of the capillary tube 35.

  As described above, the refrigerator according to the present invention can automatically adjust the amount of squeezing of the refrigeration cycle according to the load of the refrigeration room to achieve high performance. Applicable to applied products.

DESCRIPTION OF SYMBOLS 11 Refrigerator 12 Case 13 Door 14 Leg 15 Lower machine room 16 Upper machine room 17 Refrigeration room 18 Freezing room 19 Compressor 20 Evaporator 21 Main condenser 22 Bulkhead 23 Fan 24 Evaporating dish 25 Bottom plate 26 Inlet 27 Outlet 28 Ventilation path 30 Dew prevention pipe A
31 Dew prevention pipe B
32 Flow path switching valve 33 Junction point 34 Dryer 35 Capillary tube 35a Inlet side non-heat exchanging part 36 Suction 37 Heat radiation plate 38 Evaporator fan 39 Cold room damper 40 Cold room cooling air path 41 Solder

Claims (4)

The casing includes at least a compressor, a condenser, a capillary tube, an evaporator, an evaporator fan, a refrigeration cycle having a suction, a refrigeration chamber, and a freezing chamber, and in order to perform internal heat exchange of the refrigeration cycle, Cold air that has an internal heat exchange part that thermally couples the capillary tube and the suction, and that is supplied to the refrigerating chamber by the evaporator fan at the non-heat exchange part upstream of the internal heat exchange part in the capillary tube The refrigerator is characterized by being cooled by. A heat dissipating plate thermally coupled to the non-heat exchanging part on the inlet side of the internal heat exchanging part in the capillary tube and having a surface area of 2 to 10 times that of the non-heat exchanging part on the inlet side of the capillary tube; The refrigerator according to claim 1, wherein the refrigerator is cooled by cold air supplied to a refrigerator compartment by the evaporator fan. The refrigerator according to claim 1 or 2, further comprising a suction and a fin that is formed in the tube of the suction and expands the surface area of the tube by 1.5 to 5 times. A plurality of dew-proof pipes and a switching valve for switching the dew-proof pipes, all of the dew-proof pipes are used at high loads, and some of the dew-proof valves are switched at normal loads. The refrigerator according to any one of claims 1 to 3, wherein only a pipe is selectively used.