JP5031045B2 - Freezer refrigerator - Google Patents

Description

  The present invention relates to a hot gas bypass defrosting of a refrigerator-freezer.

  The refrigeration cycle of the refrigerator / freezer is composed of a compressor, a condenser, a capillary tube, and an evaporator in this order, and cools the air in the cabinet with the evaporator. The air cooled by the evaporator is sent out to the room (a refrigerator room, a freezer room, a vegetable room, etc.) by a fan in the cabinet, and becomes a circulation air path that returns from the room to the evaporator again. Moisture contained in the room air due to door opening and closing and foods adheres to the surface of the low-temperature evaporator and forms frost. When the cooling operation is performed for about one day, the evaporator is covered with frost, the ventilation resistance of the evaporator is increased and the air volume is decreased, and the thermal resistance between the refrigerant and the air is increased and the refrigeration capacity is decreased. Therefore, it is necessary to defrost the evaporator once a day in order to prevent a decrease in capacity.

In Patent Document 1, as a defrosting means, a hot gas system in which a bypass pipe connecting between a compressor and a condenser and between a capillary tube and an evaporator is connected, and a refrigerant flow path is switched to the bypass pipe during a defrosting operation. Is disclosed. Further, an operation method is disclosed in which the compressor is stopped when the temperature of the evaporator reaches a predetermined temperature during the defrosting operation. In addition, an operation method is disclosed in which a heater is disposed in a tray section disposed at the lower part of the evaporator, and the heater is heated when the temperature of the tray section reaches around 0 ° C.
Japanese Patent Application Laid-Open No. H10-228667 discloses a refrigeration cycle provided with a hot gas bypass circuit and flowing hot gas to an evaporator via a drain pan.
Patent Document 3 discloses a refrigeration cycle provided with a hot gas bypass circuit, having two bypass pipes, a bypass 1 that passes directly to the evaporator, and a bypass 2 that goes through a tray pipe.

JP-A-2005-249254 (pages 4 to 6, FIG. 1) JP-A-61-159072 (pages 3 to 4, FIGS. 1 and 2) Japanese Utility Model Publication No. 62-093659 (pages 3 to 4, page 8, FIG. 2)

The current refrigerator is generally a heater type defrost, but in the form in which the evaporator is arranged in the vicinity of the freezer compartment, the ratio of the heat of the heater leaking into the cabinet is high, and the power consumption is increased. In the hot gas type, the cooler can be directly heated. However, there are problems that frost falls and remains in the tray, and that heat is radiated from the compressor shell and there is little heat available for defrosting.
In the refrigerator-freezer disclosed in Patent Document 1, as described above, the hot gas method is used for the defrosting of the evaporator, and the heater method is used for the defrosting of the tray. The power saving effect is inadequate in that some heaters are used, and the configuration is complicated in that it is used in combination with a hot gas circuit. In addition, immediately after the defrosting is completed, normal operation is immediately started, so the heat of the evaporator heated during the defrosting is dissipated into the chamber, so that the temperature inside the chamber rises and wasteful power for cooling is consumed. Not only consume, but also reduce food quality.
Although what was disclosed by patent document 2 and patent document 3 uses the hot gas system for the defrosting of a tray and an evaporator, it does not consider about the operation | movement used as power saving. Further, since all the defrost is processed by the evaporator during normal operation, it is likely to be clogged by the frost that has fallen and accumulated on the tray, and the cooling capacity is likely to decrease.

  The present invention has been made to solve the above-described problems. The main purpose of the present invention is to previously remove moisture in the air flowing into the evaporator during normal operation, thereby suppressing a decrease in cooling capacity, and defrosting operation. Sometimes, it is to reduce the amount of power consumption and prevent the temperature inside the cabinet from being raised, thereby improving the storage quality of food.

  The refrigerator-freezer according to the present invention includes a compressor, a three-way valve, a condenser, a capillary tube, a tray pipe, an evaporator, and a suction pipe that are connected in an annular manner in order and a main circuit that exchanges heat between the capillary and the suction pipe, and a three-way valve. Branch circuit from the main circuit and connected to the pipe connecting the capillary tube and the tray pipe, an evaporator fan for sending air to the evaporator, an evaporator temperature sensor for detecting the temperature of the evaporator, and the tray A tray temperature sensor that detects temperature, a control unit that controls the compressor, three-way valve, and evaporator fan, and a refrigeration housing the main circuit, bypass circuit, evaporator fan, evaporator temperature sensor, tray temperature sensor, and control unit A refrigerator body, a cooling chamber that is provided on the back side of the inside of the refrigerator refrigerator body, houses the evaporator, and is provided inside the cooling chamber, receives water and frost falling from the evaporator, A tray having a drain outlet for discharging drainage generated by melting of the outside of the cabinet, and the tray piping is installed so as to pass near the tray, and during normal cooling operation, the air in the cabinet is the tray piping. After passing through the evaporator, the defrosting operation consists of the tray and the evaporator defrosting section, and the evaporator cooling section, and the control unit is in the tray and the evaporator defrosting section. After the evaporator fan is stopped and the three-way valve is switched to the bypass circuit, the compressor is operated at the first rotation speed, the output of the tray temperature sensor reaches a predetermined temperature of 0 ° C. or more, and the evaporator temperature When the sensor output reaches a predetermined temperature of 0 ° C. or higher, the operation proceeds to the evaporator cooling section. In the evaporator cooling section, the three-way valve is switched to the main circuit, and then the compressor is moved beyond the first rotational speed. Drive at a low second speed, Hatsuki is to resume operation of the evaporator fan when the output of the temperature sensor becomes 0 ℃ less below the predetermined temperature.

  According to the present invention, the moisture of the air flowing into the evaporator during normal operation is removed by frosting on the tray piping in advance, and the defrosting operation is efficiently defrosted with the hot gas bypass type. In addition to reducing the amount of power consumed during operation, it is possible to improve the storage quality of food by preventing temperature rise in the storage.

It is a circuit diagram of the refrigerating cycle in Embodiment 1 of this invention. It is a rear view of the refrigerator-freezer in Embodiment 1 of this invention. It is a front view of the cooling chamber 17 of the refrigerator-freezer in Embodiment 1 of this invention. It is the front view and side view which show the tray 19 of the refrigerator-freezer in Embodiment 1 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 1 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 1 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 1 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 1 of this invention. It is side surface sectional drawing of the cooling chamber 17 in Embodiment 1 of this invention. It is a control flowchart of the refrigerator-freezer in Embodiment 1 of this invention. It is a control time chart of the refrigerator-freezer in Embodiment 1 of this invention. It is another control flowchart of the refrigerator-freezer in Embodiment 1 of this invention. It is a control time chart corresponding to the control flow of FIG. It is a rear view of the refrigerator-freezer in Embodiment 2 of this invention. It is a front view of the cooling chamber 17 of the refrigerator-freezer in Embodiment 2 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 2 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 2 of this invention. It is a top view of tray piping 8 of the refrigerator-freezer in Embodiment 2 of this invention. It is a circuit diagram of the refrigerating cycle in Embodiment 3 of this invention. It is a rear view of the refrigerator-freezer in Embodiment 3 of this invention. It is a front view of the cooling chamber 17 of the refrigerator-freezer in Embodiment 3 of this invention. It is a rear view of another freezer refrigerator in Embodiment 3 of this invention. It is a front view of the cooling chamber 17 of the refrigerator-freezer of FIG. It is a front view of the cooling chamber 17 of the refrigerator-freezer in Embodiment 4 of this invention. It is a front view of the cooling chamber 17 of the refrigerator-freezer in Embodiment 5 of this invention. It is a control flowchart of the refrigerator-freezer in Embodiment 6 of this invention. It is the evaporator 5 path | pass structure of the refrigerator-freezer in Embodiment 1 of this invention. It is a block which shows the structure of the control system in Embodiment 1 of this invention. It is a block diagram which shows the structure of the control system in Embodiment 6 of this invention.

Embodiment 1 FIG.
FIG. 1 is a circuit diagram of a refrigeration cycle showing Embodiment 1 of the present invention. In FIG. 1, the refrigerant circuit is composed of a compressor 1, a three-way valve 2, a condenser 3, a dryer 14, a capillary 4, a tray pipe 8 arranged on the upper surface of a tray 19 described later, an evaporator 5, and a suction pipe 22. There is a main circuit 6 in which the capillary 4 and the suction pipe 22 exchange heat, and a bypass circuit 9 that branches off at the three-way valve 2 and is connected between the capillary 4 and the tray pipe 8. There is also an evaporator fan 23 that blows the air cooled by the evaporator 5 into the interior.

  FIG. 2 is a rear view of the refrigerator-freezer according to Embodiment 1 of the present invention. There is a machine room 10 on the lower side of the back surface. The machine room 10 includes a compressor 1, a three-way valve 2, a machine room fan 11 for forced air cooling of the shell of the compressor 1, a forced air cooling condenser 3, a drain pan 13, A dryer 14 is included. The piping of the main circuit 6 of the refrigeration cycle is connected from the compressor 1 to the three-way valve 2 and the forced air-cooled condenser 3, and after exiting the forced air-cooled condenser 3, it is placed inside the steel plate 15 of the refrigerator that is a natural heat dissipation condenser. Connect to the installed piping. The main circuit 6 passes from the natural heat dissipation condenser through the dryer 14 through the capillary tube 4 disposed inside the heat insulating wall 16 and enters the refrigerator through the hole 18 at the inlet of the cooling chamber.

  On the other hand, the bypass circuit 9 exits the three-way valve 2 and then passes through the inside of the heat insulating wall 16 on the back of the refrigerator, and enters the refrigerator through the hole 18 at the cooling chamber inlet. If the pipe from the three-way valve 2 to the hole 18 at the cooling chamber inlet is passed through the range from the center to the outer half in the thickness direction inside the heat insulating wall 16 on the back of the refrigerator, heat insulation is good and wasteful heat dissipation can be prevented. The heat of hot gas can be efficiently used for defrosting. However, when the pipe touches the steel plate 15 on the back surface, heat is easily released to the outside due to the fin effect, so that the steel plate 15 is not touched.

  FIG. 3 is a front view of cooling chamber 17 according to Embodiment 1 of the present invention. FIG. 4 is a front view and a side view showing the tray 19. There is an evaporator 5 at the center of the cooling chamber 17, and an evaporator fan 23 that blows air cooled by the evaporator 5 into the chamber at the top. Under the evaporator 5, there is a tray 19, and the main circuit 6 entering from the inlet hole 18 of the cooling chamber 17 is connected to the evaporator 5 through a tray pipe 8 arranged on the tray 19. The bypass circuit 9 is connected between the throttle mechanism 7 and the tray pipe 8. Note that the bypass circuit 9 does not necessarily enter the refrigerator through the hole 18 at the cooling chamber inlet, and may be connected to the main circuit 6 in the heat insulating wall 16 on the rear surface of the refrigerator.

  5, 6, 7 and 8 are top views of the tray pipe 8 according to the first embodiment of the present invention. The tray 19 has a width of about 400 mm and a depth of about 70 mm, and the tray 19 has a drain outlet 20 at the center. For example, the tray pipe 8 is arranged around the drain outlet 20 as shown in FIG. Further, as shown in FIG. 6, the tray pipe 8 is bent six times in a meandering manner, and arranged so as to pass along the drain port 20 or to pass over the drain port 20. The tray pipe 8 may be wound around the circumference of the drain port 20 as shown in FIG.

  When the shape of the tray pipe 8 is meandered, the heat transfer area with the frost increases and the defrosting time can be shortened. A drain hose 21 is connected to the tip of the drain port 20, and the drain flows from the tray 19 through the drain hose 21 to the drain pan 13 of the machine room 10. The drain port 20 may be frozen and blocked during the cooling operation, and if the drain port 20 is blocked at the start of defrosting, the drain overflows from the tray 19 and leaks into the cabinet. By passing the tray pipe 8 over the circumference of the drain port 20 or the drain port 20, the drain port 20 is warmed simultaneously with the defrosting operation and the ice in the drain port 20 melts, so that the drain can be prevented from overflowing. By forming the tray pipe 8 on the circumference of the drain port 20, the drain port 20 is further easily heated.

  When the tray pipe 8 is placed along the entire tray 19, the defrosting time is faster, but the size of the tray 19 is about 400mm wide and about 70mm deep, and the tray pipe 8 is made of copper with a diameter of 4mm and a wall thickness of 0.3mm. The minimum radius of bending is about 15 mm, and even if meandering, it will be 6 or 7 reciprocations at most. The inlet and outlet pipes of the evaporator 5 are unified on the side closer to the hole 18 at the inlet of the cooling chamber so that the handling is easy. The tray pipe 8 is also connected to the same side as the cooling chamber inlet hole 18 and the evaporator 5 inlet so that the pipe can be connected without waste.

  In FIG. 8, the tray pipe 8 is arranged in the width direction of the tray 19, and the number of bendings is reduced and the productivity is better than the meandering. In order to unify the entrance / exit of the tray piping 8 on the same side, the piping shape is as shown in FIG.

  Next, the operation will be described. In a normal cooling operation, the discharge gas of the compressor 1 is caused to flow to the main circuit 6 by the three-way valve 2 and the bypass circuit 9 is closed. The gas refrigerant compressed to high temperature and high pressure by the compressor 1 dissipates heat to the outside by the condenser 3 and is condensed into liquid refrigerant, becomes low temperature and low pressure by the capillary 4, and sucks heat from the air by the tray pipe 8 and the evaporator 5. The refrigerant evaporates. Air cooled by passing through the tray pipe 8 and the evaporator 5 circulates in the cabinet to cool the room. Moisture in the outside air that flows into the cabinet when the door is opened and closed and frost from the food form frost in the evaporator 5, so if the cooling operation is performed for about one day, the evaporator 5 is covered with frost and the ventilation resistance increases. As the air volume decreases, the thermal resistance between the refrigerant and the air increases and the refrigeration capacity decreases. Therefore, it is necessary to defrost the evaporator 5 about once a day in order to prevent a decrease in capacity.

  Here, FIG. 9 shows a cross-sectional view of the cooling chamber 17 as seen from the side. The air flowing in from the refrigerator is represented by a thick line. The air that has flowed downward from the suction port flows along the tray 19 and then flows into the evaporator 5 from the back side. By disposing the tray pipe 8 on the tray 19, a part of the frost of the evaporator 5 can be frosted on the tray pipe 8, and the amount of frost on the evaporator 5 can be reduced. Since the wind speed of the air is fast on the tray 19, the amount of frost formation can be increased. In addition, since the space through which air flows is vacant in the tray pipe 8 as compared with the evaporator 5, clogging is less likely, cooling capacity reduction in the evaporator 5 can be suppressed, and the cooling operation time can be extended.

  In the defrosting operation, the discharge gas of the compressor 1 is caused to flow to the bypass circuit 9 by the three-way valve 2, and the main circuit 6 is closed. A high-temperature gas refrigerant flows into the evaporator 5 through the tray pipe 8 and melts the frost in the tray pipe 8 and the evaporator 5. Since the frost in the tray pipe 8 is accumulated on the pipe and gradually melts, the frost in the evaporator 5 melts from the pipe and the fin surface, so that the frost slides down from the upper part of the evaporator 5 to the lower part. It falls to the tray 19 below the evaporator 5. In other words, since frost tends to remain in the lower part of the evaporator 5, as shown in FIG. 27, if the path configuration is such that a high-temperature refrigerant flows from the lower part of the evaporator 5 upward, the frost in the lower part of the evaporator 5 is reduced. It becomes easier to dissolve and is more preferable. Further, the frost dropped from the evaporator 5 can be melted by the tray pipe 8. As a result, when the cooling operation is resumed while the frost remains on the tray 19, the frost grows greatly, and finally the air path is blocked and the cold air cannot reach the room and can be prevented from being cooled.

  FIG. 28 is a block diagram showing the configuration of the control system in the first embodiment of the present invention. As shown in FIG. 28, the control system includes a control unit 31, an evaporator temperature sensor 32 connected to the control unit 31, a tray temperature sensor 33, an evaporator fan 23 and a fan motor 231, the compressor 1 and The compressor motor 101, the three-way valve 2, and the three-way valve driving means 201 are configured.

  Next, the control operation will be described with reference to FIG. 1, FIG. 10, FIG. 11, and FIG. When the defrosting operation is started, the control unit 31 controls the fan motor 231 to stop the evaporator fan 23 (step S11), and controls the three-way valve driving means 201 to bypass the discharge gas of the compressor 1 by a bypass circuit. After switching the three-way valve 2 to flow to 9 (step S12), the compressor motor 101 is controlled to change the frequency of the compressor 1 to the defrosting frequency α (step S13) (STEP 1). In general, during normal operation, the compressor 1 is operated at a lower frequency, so the frequency α during defrosting is greater than the frequency during normal operation. The defrosting time can be shortened by setting the value as large as possible in consideration of the current value limitation and the liquid back reliability to the compressor 1. When the three-way valve 2 is switched to the bypass circuit 9, the high and low pressures approach the pressure equalization state, and the refrigerant suddenly flows into the bypass circuit 9 to generate refrigerant noise. Therefore, in order to solve this problem, it is preferable to reduce the frequency of the compressor 1 or stop the compressor 1 before switching the three-way valve 2 to the bypass circuit 9. At this time, if the compressor 1 is stopped, it is necessary to ensure the time until restart for reliability, and it takes time for defrosting. Therefore, the frequency of the compressor 1 is reduced to the minimum rotational speed. Is more preferable.

  Next, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32 and the temperature of the tray 19 detected by the tray temperature sensor 33, and the temperature of the evaporator 5 is equal to or higher than Te ° C. When the temperature of the tray 19 becomes equal to or higher than Tt ° C. (Yes in Step S14), the control unit 31 switches the three-way valve 2 from the bypass circuit 9 to the normal circuit (main circuit) 6 (Step S21), and the frequency of the compressor 1 is changed. It changes to β (step S22) (STEP2). Here, Te ° C. and Tt ° C. are values of 0 ° C. or more, and are set so that the evaporator temperature sensor 32 and the tray temperature sensor 33 respectively detect that the frost on the tray 19 and the evaporator 5 has melted reliably. Temperature. Further, the frequency β of the compressor 1 is a value set for cooling the evaporator 5 warmed in the defrosting operation before shifting to the normal operation, and the evaporator 5 is cooled as soon as possible. Since the evaporator fan 23 is stopped, the frequency β of the compressor 1 may be set large so that the low pressure does not decrease too much. Further, when the temperature of the evaporator 5 detected by the evaporator temperature sensor 32 becomes equal to or lower than Te2 ° C. (Yes in Step S23), the control unit 31 ends the defrosting operation (Step S24). After completion of the defrosting operation, the control unit 31 controls the fan motor 231 to operate the evaporator fan 23, controls the compressor motor 101 to set the frequency of the compressor 1 to the normal operation state, and performs normal operation (cooling). (Operation 3) (STEP 3). The operation after STEP 2 is a time provided for cooling the evaporator 5, and the defrosting operation may be terminated after a predetermined time regardless of the temperature of the evaporator 5.

In the control example described above, the tray 19 and the evaporator 5 are simultaneously defrosted. However, when the frost of the evaporator 5 falls on the tray 19, the temperature rise of the tray 19 is delayed. Considering this, a more preferable control operation will be described.
FIG. 12 is another control flowchart of the refrigerator-freezer according to Embodiment 1 of the present invention. FIG. 13 is a control time chart corresponding to the control flow of FIG. Next, this control example will be described with reference to FIG. 1, FIG. 12, FIG. 13 and FIG.
Since the defrosting operation is started and the control up to STEP 1 is the same as the control shown in FIG.

  After STEP 1, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32, and when the temperature of the evaporator 5 becomes equal to or higher than Te ° C. (Yes in step S <b> 15), the control unit 31 detects the compressor 1. Is changed to γ (step S121) (STEP 12). Here, Te ° C. is a value equal to or higher than 0 ° C., and is a temperature set for the evaporator temperature sensor 32 to detect that the defrosting of the evaporator 5 has been completed with certainty. As described above, since the frost in the evaporator 5 may fall on the tray 19, the temperature rises when the frost in the evaporator 5 disappears. After the temperature of the evaporator 5 becomes 0 ° C. or higher, an operation for melting the frost that has fallen on the tray 19 is required. The frequency γ of the compressor 1 takes a value necessary for melting the frost of the evaporator 5 that has fallen on the tray 19, but the tray pipe 8 has a smaller area than the evaporator 5, and if the frequency value is large, the tray Since the evaporator 5 is heated too much than the pipe 8, a value smaller than the frequency α is desirable.

  Further, the control unit 31 checks the temperature of the tray 19 detected by the tray temperature sensor 33, and when the temperature of the tray 19 becomes Tt ° C. or more (Yes in step S122), the three-way valve 2 is connected from the bypass circuit 9 to the normal circuit ( The main circuit is switched to 6 (step S21), and the frequency of the compressor 1 is changed to β (step S22) (STEP2). Here, Tt ° C. is a value equal to or higher than 0 ° C., and is a temperature set in order for the tray temperature sensor 33 to detect that the frost on the tray 19 has been reliably melted. The frequency β of the compressor 1 is a value set for cooling the evaporator 5 warmed in the defrosting operation before shifting to the normal operation, and is compressed to cool the evaporator 5 as soon as possible. The value is larger than the frequency γ of the machine 1. At this time, since the evaporator fan 23 is stopped, the frequency β of the compressor 1 may be set to a large value so that the low pressure does not decrease too much. Further, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32, and when the temperature of the evaporator 5 becomes Te2 ° C. or lower (Yes in step S23), the control unit 31 performs the defrosting operation. The process is terminated (step S24), and the evaporator fan motor 231 is controlled to operate the evaporator fan 23 to shift to a normal operation (cooling operation) (STEP 3). The operation after STEP 2 is a time provided for cooling the evaporator 5, and the defrosting operation may be terminated after a predetermined time regardless of the temperature of the evaporator 5.

  As described above, since a part of the frost that forms on the evaporator 5 can be frosted by the tray pipe 8 during the cooling operation of the refrigerator-freezer, the cooling operation time can be increased. Moreover, in order to efficiently process the frost on the tray 19 and the evaporator 5 with hot gas in the hot gas bypass defrosting, the defrosting time is shortened to save energy, and the rise in the internal temperature is suppressed to improve the quality of food. Can be kept in.

Embodiment 2. FIG.
In the first embodiment described above, the bypass circuit 9 is inserted from the back surface of the cooling chamber 17 into the cabinet. Next, an embodiment in which the bypass circuit 9 is inserted into the cooling chamber 17 from the drain port 20 will be described. FIG. 14 is a rear view of the refrigerator-freezer according to Embodiment 2 of the present invention. A machine room 10 is provided on the lower side of the back surface, and a compressor 1, a three-way valve 2, a machine room fan 11, a forced air cooling condenser 3, a drain pan 13, and a dryer 14 are placed in the machine room 10. The piping of the main circuit 6 of the refrigeration cycle is connected from the compressor 1 to the three-way valve 2 and the forced air-cooled condenser 3, and after exiting the forced air-cooled condenser 3, it is placed inside the steel plate 15 of the refrigerator that is a natural heat dissipation condenser. Connect to the installed piping. On the other hand, the bypass circuit 9 exits the three-way valve 2, passes through the drain hose 21, and enters the cooling chamber 17 from the drain port 20 of the tray 19.

  FIG. 15 is a front view of cooling chamber 17 according to Embodiment 2 of the present invention. There is an evaporator 5 in the center of the cooling chamber 17, and a tray 19 below the evaporator 5, and the bypass circuit 9 entered from the hole of the tray 19 is connected to the main circuit 6, and then along the tray 19. It can be bent.

  16, 17 and 18 are top views of the tray piping 8 according to the second embodiment of the present invention. The tray 19 has a drain outlet 20 at the center, and the bypass circuit 9 enters the cabinet from the drain outlet 20 and is connected to the main circuit 6, and then follows the tray 19 so as to draw a character “NO”. Shape. If the pipe is copper with an outer diameter of 4 mm and a wall thickness of about 0.3 mm, the minimum radius of bending of the pipe is about 15 mm and the depth of the tray 19 is as narrow as 60 to 80 mm. In the case of the character, it is possible to arrange the pipes on the tray 19 in general without overlapping the pipes, and the end point of the tray pipe 8 becomes the corner of the tray 19 and the connection to the inlet of the evaporator 5 becomes easy. As shown in FIG. 17, when a part of the character “no” is meandered, the heat transfer area increases and the defrosting time can be shortened.

  When the drain outlet 20 is open at the center of the tray 19, as shown in FIG. 4, the bottom surface of the tray 19 is pointed downward and the drain is collected at the center. As shown in FIG. 18, when the tray pipe 8 has a butterfly shape or a figure 8 shape along the corner of the tray 19, the pipe can be easily installed on the tray 19. In addition, water droplets easily flow to the drain port 20.

  Since the defrosting control operation is the same as that of the first embodiment, the description thereof is omitted.

Embodiment 3 FIG.
In the first and second embodiments described above, the bypass circuit 9 enters the evaporator 5 via the tray pipe 8. Next, an embodiment having a circuit for flowing hot gas directly to the evaporator 5 will be described. .

  FIG. 19 is a circuit diagram of a refrigeration cycle in Embodiment 3 of the present invention. The bypass circuit 9 is bifurcated to have a path that passes from the throttle mechanism 7B through the tray pipe 8 to the evaporator 5 and a path that directly enters the evaporator 5 from the throttle mechanism 7A.

  FIG. 20 is a rear view of the refrigerator according to Embodiment 3 of the present invention. The bypass circuit 9 exits the three-way valve 2 and then passes through the inside of the heat insulating wall 16 on the back of the refrigerator, and enters the refrigerator through the hole 18 at the cooling chamber inlet.

  FIG. 21 is a front view of cooling chamber 17 according to Embodiment 3 of the present invention. There is an evaporator 5 in the center of the cooling chamber 17 and a tray 19 below the evaporator 5, and one of the bypass circuits 9 entering from the hole 18 at the inlet of the cooling chamber is directly connected to the inlet of the evaporator 5. One is connected to the main circuit 6 and connected to the evaporator 5 inlet through the tray pipe 8.

FIG. 22 is a rear view of another refrigerator according to Embodiment 3 of the present invention.
In the example shown in FIG. 22, the bypass circuit 9 is branched into two, one passes through the drain hose 21 and enters the cooling chamber 17 from the drain port 20, and the other passes through the inside of the heat insulating wall 16 on the back of the refrigerator. Enter the cooling chamber 17 through the hole 18 at the entrance. FIG. 23 is a front view of the cooling chamber 17 of the refrigerator-freezer of FIG. There is an evaporator 5 at the center of the cooling chamber 17, a tray 19 below the evaporator 5, and the bypass circuit 9 entered from the drain port 20 is connected to the main circuit 6, passed through the tray pipe 8, The bypass circuit 9 connected to the inlet of the evaporator 5 and entering from the hole 18 at the cooling chamber inlet is directly connected to the inlet of the evaporator 5.

  Since the defrosting control operation is the same as that of the first embodiment, the description thereof is omitted.

Embodiment 4 FIG.
In the above first to third embodiments, as shown in FIG. 4, the drain 19 is in the center of the tray 19, and the tray 19 is recessed downward toward the center. The form of a plane is shown.

  FIG. 24 is a front view of cooling chamber 17 according to the fourth embodiment of the present invention. The floor surface of the tray 19 is inclined obliquely so that the left rear surface is the lowest. When the tray pipe 8 is bent as shown in FIGS. 5 to 8 and 16 to 18, if the floor surface of the tray 19 is flat, the arrangement is easy. In FIG. 24, the bypass circuit 9 is put into the cabinet through the hole 18 at the cooling chamber inlet, but it may be put into the cabinet through the drain outlet 20 as in Embodiment 2, and the configuration of the bypass circuit 9 is also shown in FIG. It can be applied to either of FIG. The tilt of the tray 19 is not limited to the left rear surface, and the tray 19 may be tilted so that one corner at the left and right front and rear is lowest.

Embodiment 5 FIG.
In the first to fourth embodiments described above, the tray pipe 8 is placed on the tray 19. Next, a form in which the tray pipe 8 is provided below the tray 19 will be described.
FIG. 25 is a front view of cooling chamber 17 of the refrigerator-freezer according to Embodiment 5 of the present invention.
The tray 19 in FIG. 25 and the tray pipe 8 can be brought into contact with each other to uniformly warm the tray 19 to melt the residual frost. When the tray 19 is made of aluminum, the thermal conductivity is high and the defrosting efficiency is increased. The tray pipe 8 may be installed outside the drain port 20 and along the drain hose 21. The drain hose 21 may be bent from the positional relationship with the drain pan 13 or may have a structure in which a water reservoir is formed by meandering up and down in order to prevent air flow. It may be difficult to install the cooling chamber 17 in the cooling chamber 17. By arranging along the outside of the drain hose 21, the shape of the drain hose 21 becomes free and the production efficiency is good.

Embodiment 6 FIG.
As shown in FIG. 19, a control method for flowing hot gas in a mode in which there are two bypass circuits 9 and a route for entering the evaporator 5 via the tray pipe 8 and a route for flowing the hot gas directly to the evaporator 5 will be described.

  FIG. 29 is a block diagram showing a configuration of a control system in the sixth embodiment of the present invention. In FIG. 29, in place of the diaphragm mechanism 7 and the diaphragm mechanism driving means 701, the structure of FIG. 28 is provided except that a diaphragm mechanism 7A, a diaphragm mechanism driving means 7A1, a diaphragm mechanism 7B, and a diaphragm mechanism driving means 7B1 are provided. The same.

FIG. 26 is a flowchart of the control unit in the sixth embodiment of the present invention.
Next, the operation of the control unit 31 in the sixth embodiment will be described with reference to FIGS. When the frosting amount of the evaporator 5 is large, the frost falls from the evaporator 5 to the tray 19, so that the throttle mechanism 7A is closed and the throttle mechanism 7B is opened, as in the first or second embodiment. Therefore, the description is omitted.
When the frosting amount of the evaporator 5 is small, that is, when the frost is completely melted in the evaporator 5, the temperature rise of the tray 19 becomes large, and wasteful energy is consumed on the tray piping side. It is more efficient to let hot gas flow through. The operation of the control unit when hot gas is allowed to flow only to the evaporator 5 will be described below.
In addition, although it is about some judgment of the amount of frost formation of the said evaporator 5, this is the predetermined value (upper limit value) in which the temperature of the tray 19 detected by the tray temperature sensor 33 is 0 degreeC or more, for example in a defrost operation. ), The control unit 31 melts and the frost is hardly dropped because the amount of frost formation on the evaporator 5 is small, and the temperature of the tray 19 reaches the upper limit due to the hot gas flowing in the tray pipe. What is necessary is just to comprise so that it may judge. Alternatively, if the time from the start of the defrosting operation until the temperature of the tray 19 detected by the tray temperature sensor 33 reaches a predetermined value of 0 ° C. or higher is smaller than the predetermined value, the control unit 31 causes the evaporator 5 to form frost. Since the amount is small, there is almost no drop, and the tray temperature may be determined to have reached the predetermined temperature or higher very quickly due to the hot gas flowing in the tray piping.

  When the defrosting operation is started, the control unit 31 controls the fan motor 231 to stop the evaporator fan 23 (step S11), and further controls the three-way valve driving means 201 to supply the discharge gas of the compressor 1 to the main. The three-way valve 2 is switched so as to flow from the circuit 6 to the bypass circuit 9 (step S12). The control unit 31 further controls the diaphragm mechanism driving unit 7A1 to close the diaphragm mechanism 7A, and controls the diaphragm mechanism driving unit 7B1 to open the diaphragm mechanism 7B (step S261), and then the compressor motor 101 is turned on. The frequency of the compressor 1 is controlled to be changed to the defrosting frequency α (step S13) (STEP 1). Since the compressor 1 is generally operated at a lower frequency during normal operation, the defrosting frequency α is larger than the frequency during normal operation. The defrosting time can be shortened by setting the value as large as possible in consideration of the current value limitation and the liquid back reliability to the compressor. When the three-way valve 2 is switched to the bypass circuit 9, the high and low pressures approach the pressure equalization state, so that the refrigerant suddenly flows into the bypass circuit 9 and refrigerant noise is generated. Therefore, in order to solve this problem, it is preferable to reduce the frequency of the compressor 1 or stop the compressor 1 before switching the three-way valve 2 to the bypass circuit 9. At this time, if the compressor 1 is stopped, it is necessary to ensure the time until restart for reliability, and it takes time for defrosting. Therefore, the frequency of the compressor 1 is reduced to the minimum rotational speed. Is more preferable.

Next, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32 and the temperature of the tray 19 detected by the tray temperature sensor 33, and the temperature of the evaporator 5 is equal to or lower than Te ° C. When the temperature of the tray 19 becomes equal to or higher than Tt ° C. (Yes in step S262), the control unit 31 controls the aperture mechanism driving unit 7A1 to open the aperture mechanism 7A, and further controls the aperture mechanism driving unit 7B1 to control the aperture mechanism. 7B is closed (step S263). As a result, the hot gas stops flowing into the tray pipe 8 and flows only into the evaporator 5. Here, Tt ° C. is a value equal to or higher than 0 ° C., and is a temperature set for the tray temperature sensor 33 to detect that the frost on the tray has surely melted. Next, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32, and when the temperature of the evaporator 5 reaches Te ° C. (Yes in step S264), the control unit 31 detects the three-way valve driving means. 201 is controlled to switch the three-way valve 2 from the bypass circuit 9 to the main circuit 6 (step S21), and the throttle mechanism driving means 7B1 is controlled to open the throttle mechanism 7B, and the frequency of the compressor 1 is changed to β. (Step S22). Here, Te ° C. is a value equal to or higher than 0 ° C., and is a temperature set for the evaporator temperature sensor 32 to detect that the defrosting of the evaporator 5 has been completed with certainty. The frequency β of the compressor 1 is a value that is set for the evaporator temperature sensor 32 to detect that the evaporator 5 has been cooled, and is cooled as soon as possible, but the evaporator fan 23 is stopped. It is preferable to set the compressor frequency β large so that the low pressure does not decrease too much. Further, the control unit 31 checks the temperature of the evaporator 5 detected by the evaporator temperature sensor 32, and when the temperature of the evaporator 5 becomes Te2 ° C. or lower (Yes in step S23), the control unit 31 performs the defrosting operation. The process is terminated (step S24), and the evaporator fan motor 231 is controlled to operate the evaporator fan 23 to shift to a normal operation (cooling operation) (STEP 3).
The cooling operation of the evaporator 5 may end the defrosting operation after a predetermined time regardless of the temperature of the evaporator 5.

Embodiment 7 FIG.
The compressor 1 of the refrigerator is a low-pressure shell, the discharge pipe is routed in the shell to dissipate heat, and the shell is forcibly air-cooled from the outside by the machine room fan 11, so that heat that can be used for defrosting is exhausted to the machine room 10. It is heated. If the rotational speed of the machine room fan 11 is reduced or stopped during defrosting in order to reduce shell heat dissipation, heat used for defrosting increases.

  As an application example of the present invention, it is suitable for a refrigerator-freezer.

  1 compressor, 2 three-way valve, 3 condenser, 4 capillary tube, 5 evaporator, 6 main circuit, 7, 7A, 7B throttle mechanism, 8 tray piping, 9 bypass circuit, 10 machine room, 11 machine room fan, 13 drain pan , 14 Dryer, 15 Steel plate, 16 Heat insulation wall, 17 Cooling chamber, 18 Cooling chamber inlet hole, 19 Tray, 20 Drain port, 21 Drain hose, 22 Suction pipe, 23 Evaporator fan, 31 Control unit, 32 Evaporator temperature Sensor, 33 tray temperature sensor, 101 compressor motor, 201 three-way valve drive means, 231 fan motor, 701, 7A1, 7B1 throttle mechanism drive means.

Claims (13)

A main circuit in which a compressor, a three-way valve, a condenser, a capillary tube, a tray pipe, an evaporator, and a suction pipe are sequentially connected in a ring shape, and the capillary pipe and the suction pipe exchange heat;
A bypass circuit branched from the main circuit at the three-way valve and connected to a pipe connecting the capillary and the tray pipe;
An evaporator fan that sends air to the evaporator;
An evaporator temperature sensor for detecting the temperature of the evaporator;
A tray temperature sensor for detecting the temperature of the tray;
A control unit for controlling the compressor, the three-way valve, and the evaporator fan;
The main body, the bypass circuit, the evaporator fan, the evaporator temperature sensor, the tray temperature sensor, and the refrigerator main body that houses the control unit,
A cooling chamber which is provided on the inner back side of the refrigerator-freezer body, and stores the evaporator;
A tray that is provided inside the cooling chamber, receives water and frost falling from the evaporator, and has a drain outlet for discharging drainage generated by melting of the water and frost to the outside of the chamber;
The tray piping is installed so as to pass near the tray,
During normal cooling operation, the air in the warehouse is configured to pass through the evaporator after passing through the tray pipe,
The defrosting operation consists of a tray and an evaporator defrosting section and an evaporator cooling section,
In the tray and the evaporator defrosting section, the control unit stops the evaporator fan, switches the three-way valve to a bypass circuit, and then operates the compressor at a first rotational speed.
When the output of the tray temperature sensor reaches a predetermined temperature of 0 ° C. or higher and the output of the evaporator temperature sensor reaches a predetermined temperature of 0 ° C. or higher, the operation proceeds to the evaporator cooling section,
In the evaporator cooling section, after switching the three-way valve to the main circuit, the compressor is operated at a second rotational speed lower than the first rotational speed, and the output of the evaporator temperature sensor is A refrigerator-freezer, wherein the operation of the evaporator fan is resumed when the temperature becomes a predetermined temperature of 0 ° C. or lower. A main circuit in which a compressor, a three-way valve, a condenser, a capillary tube, a tray pipe, an evaporator, and a suction pipe are sequentially connected in a ring shape, and the capillary pipe and the suction pipe exchange heat;
A bypass circuit branched from the main circuit at the three-way valve and connected to a pipe connecting the capillary and the tray pipe;
An evaporator fan that sends air to the evaporator;
An evaporator temperature sensor for detecting the temperature of the evaporator;
A tray temperature sensor for detecting the temperature of the tray;
A control unit for controlling the compressor, the three-way valve, and the evaporator fan;
The main body, the bypass circuit, the evaporator fan, the evaporator temperature sensor, the tray temperature sensor, and the refrigerator main body that houses the control unit,
A cooling chamber which is provided on the inner back side of the refrigerator-freezer body, and stores the evaporator;
A tray that is provided inside the cooling chamber, receives water and frost falling from the evaporator, and has a drain outlet for discharging drainage generated by melting of the water and frost to the outside of the chamber;
The tray piping is installed so as to pass near the tray,
During normal cooling operation, the air in the warehouse is configured to pass through the evaporator after passing through the tray pipe,
The defrosting operation consists of a tray and evaporator defrosting section, a tray defrosting section, and an evaporator cooling section,
In the tray and the evaporator defrosting section, the control unit stops the evaporator fan, switches the three-way valve to the bypass circuit, and then operates the compressor at a first rotational speed.
When the output of the evaporator temperature sensor reaches a first temperature of 0 ° C. or higher, the process proceeds to the tray defrosting section,
In the tray defrosting section, the compressor is operated at a second rotational speed lower than the first rotational speed,
When the output of the evaporator temperature sensor reaches a second temperature of 0 ° C. or higher, the process proceeds to the evaporator cooling section,
In the evaporator cooling section, after switching the three-way valve to the main circuit, the compressor is operated at a third rotational speed that is lower than the first rotational speed and higher than the second rotational speed. And
The refrigerator-freezer, wherein the operation of the evaporator fan is resumed when the output of the evaporator temperature sensor becomes equal to or lower than a predetermined temperature of 0 ° C or lower. A main circuit in which a compressor, a three-way valve, a condenser, a capillary tube, a tray pipe, an evaporator, and a suction pipe are sequentially connected in a ring shape, and the capillary pipe and the suction pipe exchange heat;
A bypass circuit branched from the main circuit at the three-way valve and connected to a pipe connecting the capillary and the tray pipe;
An evaporator fan that sends air to the evaporator;
An evaporator temperature sensor for detecting the temperature of the evaporator;
A tray temperature sensor for detecting the temperature of the tray;
A control unit for controlling the compressor, the three-way valve, and the evaporator fan;
The main body, the bypass circuit, the evaporator fan, the evaporator temperature sensor, the tray temperature sensor, and the refrigerator main body that houses the control unit,
A cooling chamber which is provided on the inner back side of the refrigerator-freezer body, and stores the evaporator;
A tray that is provided inside the cooling chamber, receives water and frost falling from the evaporator, and has a drain outlet for discharging drainage generated by melting of the water and frost to the outside of the chamber;
The tray piping is installed so as to pass near the tray,
The bypass circuit further includes a first bypass circuit that is further branched into two and enters the evaporator via the tray pipe, and a second bypass circuit that directly enters the evaporator,
During normal cooling operation, the air in the warehouse is configured to pass through the evaporator after passing through the tray pipe,
The defrosting operation consists of a tray and an evaporator defrosting section and an evaporator cooling section,
In the tray and the evaporator defrosting section, the controller stops the evaporator fan, switches the three-way valve to the bypass circuit, closes the second bypass circuit, and After opening the bypass circuit and circulating the refrigerant, the compressor is operated at the first rotational speed,
When the output of the tray temperature sensor reaches a predetermined temperature of 0 ° C. or higher, it is determined that the amount of frost formation on the evaporator is small and frost has not dropped onto the tray, and the process proceeds to the evaporator cooling section. Before moving to the evaporator defrost section,
In the evaporator defrosting section, the first bypass circuit is closed, the second bypass circuit is opened and the refrigerant is circulated, and then the compressor is moved to a second lower than the first rotational speed. Drive at
When the output of the evaporator temperature sensor reaches a predetermined temperature of 0 ° C. or higher, the process proceeds to the evaporator cooling section,
In the evaporator cooling section, after the three-way valve is switched to the main circuit, the compressor is operated at a third rotational speed that is lower than the first rotational speed and higher than the second rotational speed. ,
The refrigerator-freezer, wherein the operation of the evaporator fan is resumed when the output of the evaporator temperature sensor becomes equal to or lower than a predetermined temperature of 0 ° C or lower. A main circuit in which a compressor, a three-way valve, a condenser, a capillary tube, a tray pipe, an evaporator, and a suction pipe are sequentially connected in a ring shape, and the capillary pipe and the suction pipe exchange heat;
A bypass circuit branched from the main circuit at the three-way valve and connected to a pipe connecting the capillary and the tray pipe;
An evaporator fan that sends air to the evaporator;
An evaporator temperature sensor for detecting the temperature of the evaporator;
A tray temperature sensor for detecting the temperature of the tray;
A control unit for controlling the compressor, the three-way valve, and the evaporator fan;
The main body, the bypass circuit, the evaporator fan, the evaporator temperature sensor, the tray temperature sensor, and the refrigerator main body that houses the control unit,
A cooling chamber which is provided on the inner back side of the refrigerator-freezer body, and stores the evaporator;
A tray that is provided inside the cooling chamber, receives water and frost falling from the evaporator, and has a drain outlet for discharging drainage generated by melting of the water and frost to the outside of the chamber;
The tray piping is installed so as to pass near the tray,
The bypass circuit further includes a first bypass circuit that is further branched into two and enters the evaporator via the tray pipe, and a second bypass circuit that directly enters the evaporator,
During normal cooling operation, the air in the warehouse is configured to pass through the evaporator after passing through the tray pipe,
The defrosting operation consists of a tray and an evaporator defrosting section and an evaporator cooling section,
In the tray and the evaporator defrosting section, the controller stops the evaporator fan, switches the three-way valve to the bypass circuit, closes the second bypass circuit, and After opening the bypass circuit and circulating the refrigerant, the compressor is operated at the first rotational speed,
If the output from the tray temperature sensor reaches a predetermined temperature of 0 ° C. or higher and the time from the start of operation until the output of the tray temperature sensor reaches a predetermined temperature of 0 ° C. or higher is smaller than a predetermined value, Judging that the amount of frost formation in the evaporator is small and there was no frost falling on the tray, before moving to the evaporator cooling section, moving to the evaporator defrosting section,
In the evaporator defrosting section, the first bypass circuit is closed, the second bypass circuit is opened and the refrigerant is circulated, and then the compressor is moved to a second lower than the first rotational speed. Drive at
When the output of the evaporator temperature sensor reaches a predetermined temperature of 0 ° C. or higher, the process proceeds to the evaporator cooling section,
In the evaporator cooling section, after the three-way valve is switched to the main circuit, the compressor is operated at a third rotational speed that is lower than the first rotational speed and higher than the second rotational speed. ,
The refrigerator-freezer, wherein the operation of the evaporator fan is resumed when the output of the evaporator temperature sensor becomes equal to or lower than a predetermined temperature of 0 ° C or lower.   5. The refrigerator-freezer according to claim 1, wherein the control unit reduces the frequency of the compressor to a minimum number of revolutions before switching the three-way valve to a bypass circuit.   6. The evaporator cooling section according to claim 1, wherein the evaporator fan is operated when a predetermined time elapses instead of the output of the evaporator temperature sensor not exceeding a predetermined temperature of 0 ° C. or less. The refrigerator-freezer in any one. Provided with a hole through which the piping of the evaporator enters the cooling chamber on the inner wall of the cooling chamber,
The three-way valve is provided in a machine room on the lower back side of the refrigerator-freezer body,
The bypass circuit is connected to the main circuit by passing through the inside of the heat insulation wall of the refrigerator-freezer main body after leaving the three-way valve, and connecting to the pipe connecting the capillary tube and the tray pipe. The refrigerator-freezer in any one of Claims 1-6 characterized by the above-mentioned. The tray includes a drain hose extending downward from the drain;
The bypass circuit is connected to the main circuit by passing through the drain hose and entering the cooling chamber from the drain and connecting to the pipe connecting the capillary tube and the tray pipe. Item 7. The refrigerator-freezer according to any one of Items 1 to 6.   The refrigerator refrigerator according to any one of claims 1 to 8, wherein the tray pipe passes through an outer periphery of the drain outlet and a lower surface of the tray. The tray is provided with the drain outlet in the approximate center thereof,
The refrigerator-freezer according to any one of claims 1 to 6, wherein a floor surface of the tray is inclined so as to gradually become lower from the edge toward the drain outlet.   The floor surface of the tray is flat and inclined at either the left or right side, and is inclined obliquely so that the back side is lower than the front side, and a drain outlet is provided at the lowest end. The refrigerator-freezer in any one of 1-10.   The refrigerator according to any one of claims 1 to 11, wherein the tray is made of an aluminum steel plate. The refrigerator-freezer main body is provided with a compressor in the lower back machine room and a machine room fan for cooling the compressor,
The refrigerator according to any one of claims 1 to 12, wherein the controller reduces or stops the rotation speed of the machine room fan during defrosting.

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