JP6888981B2 - Freezer refrigerator - Google Patents

Description

The present invention relates to a freezer / refrigerator having a door for opening / closing a storage chamber, a freezer / refrigerator such as a reach-in type showcase, and more particularly to a freezer / refrigerator having two independent freezing cycles.

This type of freezer / refrigerator is known, for example, in Patent Document 1. In the cooling storage of Patent Document 1, a refrigerating device is composed of a first refrigerating circuit and a second refrigerating circuit, an inverter compressor is provided in the former circuit, and a drive rotation speed is constant in the latter circuit. A compressor (called a constant speed compressor) is provided. Basically, the inverter compressor is driven to keep the temperature inside the refrigerator within the set temperature range, but if the temperature inside the refrigerator exceeds the set temperature even if the inverter compressor is driven to its output limit, it is fixed. The speed compressor is driven to keep the temperature inside the refrigerator within the set temperature range. At this time, the start of the constant speed compressor is delayed until the temperature inside the refrigerator exceeds the upper limit of the set temperature range. Also, if both compressors are being driven at the same time and the refrigerating capacity needs to be further reduced even though the drive speed of the inverter compressor has dropped to the lower limit, the constant speed compressor is stopped. Then, the temperature inside the refrigerator is kept within the set temperature range. At this time, the stop of the constant speed compressor is delayed until the temperature inside the refrigerator drops beyond the lower limit of the set temperature range. As described above, in the cooling storage of Patent Document 1, the operation of the inverter compressor and the constant speed compressor is performed by using the detection value of the temperature sensor as a parameter so that the temperature inside the storage drops according to the preset cooling characteristics. The state is controlled individually. The temperature sensor that detects the temperature inside the refrigerator is arranged on the downstream side of the fan inside the refrigerator provided in the evaporator.

Japanese Patent No. 5236245 (paragraph numbers 0038 to 0041, FIG. 3)

For example, in a reach-in type commercial refrigerator / freezer, if the surrounding environment is adversely affected, such as when the door is frequently opened and closed, the outside temperature is high, or a product with a high temperature is put in the refrigerator, the inside of the refrigerator is used. The air temperature may rise sharply and the air temperature may greatly exceed the upper limit of the set temperature range. In this way, when the air temperature in the refrigerator is abnormally high, the compressor is fully operated, so that the discharge pressure and the discharge refrigerant temperature rise abnormally, and the compressor may be overloaded. is there. A compressor that has fallen into an overloaded state in this way can be protected by stopping it immediately, but since the refrigeration cycle does not function while the compressor is stopped, it is inevitable that the temperature inside the refrigerator will rise. For this reason, there are inconveniences such as deterioration of freshness and quality of foods and the like stored in the refrigerator, and consumption of a large amount of energy at the time of restarting.

The present invention restores the compressor to a normal operating state in a shorter time when the compressor falls into an overloaded state in a freezer / refrigerator having two independent freezing cycles, and the temperature inside the refrigerator. Therefore, it is an object of the present invention to provide a freezer / refrigerator capable of effectively preventing deterioration of freshness and quality of foods and the like stored in the refrigerator while contributing to energy saving.

The present invention comprises a first refrigeration cycle 11 including a compressor 14, a condenser 15, an expander 17 and an evaporator 18 and a second refrigeration cycle 12 including a compressor 24, a condenser 25, an expander 27 and an evaporator 28. The subject is a freezer / refrigerator provided with a control device 31 for controlling the operating states of the refrigeration cycles 11 and 12. The condenser 15 of the first refrigeration cycle 11 and the condenser 25 of the second refrigeration cycle 12 are configured as one aggregate condenser 33 and share the fin group 36. The control device 31 performs normal operation control for controlling the operating states of the compressors 14 and 24 of both refrigeration cycles 11 and 12 based on the detection result of the internal temperature sensor 52 that detects the temperature of the storage chamber 3. Further, the control device 31 is an overload operation that controls the operating states of the compressors 14 and 24 of both refrigeration cycles 11 and 12 based on the detection result of the temperature sensor 41 that detects the temperature of the condenser 15 of the first refrigeration cycle 11. Take control. In the normal operation control, the compressors 14 and 24 of each refrigeration cycle 11 and 12 are operated or stopped based on the first operation control and the second operation control. In the first operation control, the compressor 14 of the first refrigeration cycle 11 is started to operate at the upper limit temperature Dn1 of the internal temperature detected by the internal temperature sensor 52, and is stopped at the lower limit temperature Df1. In the second operation control, the compressor 14 of the first refrigeration cycle 11 starts the operation when the temperature of the condenser 15 drops to the lower limit temperature Rn1, and stops the operation when the temperature rises to the upper limit temperature Rf1. In the second operation control, the compressor 24 of the second refrigeration cycle 12 starts the operation when the temperature of the condenser 25 drops to the lower limit temperature Rn2, and stops the operation when the temperature rises to the upper limit temperature Rf2. The temperature sensor 41 detected that the temperature of the condenser 15 of the first refrigeration cycle 11 was equal to or higher than the upper limit load temperature RL during normal operation control in which the compressors 14 and 24 of both refrigeration cycles 11 and 12 were operated at the same time. Overload operation control is performed in the state. In the overload operation control, the operation of the compressor 24 of the second refrigeration cycle 12 is stopped, only the compressor 14 of the first refrigeration cycle 11 is operated, and the refrigerant liquid of the condenser 15 of the first refrigeration cycle 11 is discharged. It is cooled by the centralized condenser 33. When the temperature sensor 42 detects that the temperature of the condenser 25 in the second refrigeration cycle 12 has dropped to the lower limit temperature Rn2 during the overload operation control, the operation of the compressor 24 in the second refrigeration cycle 12 is restarted. There is. The temperature sensor 41 detects that the temperature of the condenser 15 of the first refrigeration cycle 11 is equal to or less than the lower limit load temperature RM during the overload operation control in which the compressors 14 and 24 of both refrigeration cycles 11 and 12 are operated. in state, characterized in that to return to normal operation control to stop the operation of the compressor 24 of the second refrigerant cycle 12.

As shown in FIG. 4, the condensing condenser 33 is divided into the fin group 36, the condensing tube groups 37.38 of each refrigeration cycle 11/12 arranged folded back in the fin group 36, and the fin group 36 and the condensing tube group 37.38. A condenser fan 39 for supplying cooling air is provided. The condenser tube group 37 of the first refrigeration cycle 11 is arranged in the central region of the aggregate condenser 33 in a plan view, and the condensate tube group 38 of the second refrigeration cycle 12 is arranged in the peripheral region of the aggregate condenser 33.

The evaporator 18 of the first refrigeration cycle 11 and the evaporator 28 of the second refrigeration cycle 12 are configured as one integrated evaporator 45, and are arranged in a duct 6 above the storage chamber 3 of the main body case 1. The integrated evaporator 45 is provided in the fin group 46, the evaporation pipe groups 47 and 48 of each refrigeration cycle 11 and 12 arranged folded back in the fin group 46, and the duct 6, and ducts the air in the storage chamber 3 to the duct 6. It is equipped with an evaporator fan 49 that feeds toward the ceiling wall of the. The evaporation tube group 47 of the first refrigeration cycle 11 is arranged in the upper half of the fin group 46, and the evaporation tube group 48 of the second refrigeration cycle 12 is arranged below the evaporation tube group 47.

In the refrigerator / freezer of the present invention, the operation of the compressor 24 of the second refrigeration cycle 12 is stopped and the operation of the compressor 24 of the first refrigeration cycle 11 is continued in a state of shifting from the normal operation control to the overload operation control. I tried to do it. According to such a showcase, while cooling the storage chamber 3 in the first refrigeration cycle 11, the high-temperature refrigerant liquid in the first refrigeration cycle 11 is effectively cooled by the condensing condenser 33, and the first refrigeration cycle 11 The temperature of the condenser 15 can be lowered in a shorter time. This is because the centralized condenser 33 in the state where the operation of the compressor 24 of the second refrigerating cycle 12 is stopped only needs to cool the refrigerant liquid of the first refrigerating cycle 11, so that the condenser 15 of the first refrigerating cycle 11 needs to be cooled. This is because the high-temperature refrigerant liquid can be effectively cooled by the centralized condenser 33 as compared with the case where is provided alone. Further, since the temperature sensor 41 detects the temperature of the condenser 15 and controls the overload operation, the temperature sensor detects the temperature of the air in the refrigerator afterwards and overloads the inverter compressor and the constant speed compressor. This is because the overload operation control can be performed more quickly by immediately detecting the temperature of the condenser 15 as compared with the conventional device that controls.

Further, according to the refrigerator / freezer of the present invention, it is shorter than the overload countermeasure in which a part of the refrigerant discharged from the compressor is supplied to the refrigerant pipe on the indoor heat exchanger side via the bypass path. It is possible to prevent the temperature inside the refrigerator from rising while restoring the compressor 14 to a normal operating state in time. Therefore, it is possible to prevent deterioration of freshness and quality of foods and the like stored in the refrigerator while contributing to energy saving as much as the time required for the compressor 14 to recover to the normal operating state is short.

In the condensing condenser 33 provided with the fin group 36, the condensing tube groups 37 and 38 of each refrigerating cycle 11 and 12, and the condenser fan 39, the first refrigerating cycle 11 is located in the central region of the condensing condenser 33 in a plan view. The condensing tube group 37 of the second refrigeration cycle 12 was arranged in the peripheral region of the condensing condenser 33. According to such an aggregate condenser 33, in a state where the operation of the compressor 24 of the second refrigeration cycle 12 is stopped, the condensing tube group 37 of the first refrigeration cycle 11 and the area around the tube group 37 are large. By bringing new cooling air into contact with the fin group 36, the heat exchange efficiency in the condenser 15 of the first refrigeration cycle 11 can be increased. Further, the higher the heat exchange efficiency of the condenser 15, the more efficiently the first refrigeration cycle 11 can be operated.

The evaporator 18 of the first refrigeration cycle 11 and the evaporator 28 of the second refrigeration cycle 12 are configured as one integrated evaporator 45, and the evaporation tube group 47 of the first refrigeration cycle 11 is provided in the upper half of the fin group 46. The evaporation tube group 48 of the second refrigeration cycle 12 was arranged below the evaporation tube group 47. Further, the evaporator fan 49 supplies the air in the storage chamber 3 toward the ceiling wall of the duct 6. According to such an aggregate evaporator 45, the pressurized air supplied from the evaporator fan 49 tends to flow along the ceiling wall, so that the evaporation pipe group 47 and the fin group on the upper half side of the first refrigeration cycle 11 A large amount of pressurized air can be brought into contact with the 46 to effectively exchange heat, and the heat exchange efficiency of the evaporator 18 in the first refrigeration cycle 11 can be improved by that amount. Further, the higher the heat exchange efficiency of the evaporator 18, the more efficiently the first refrigeration cycle 11 can be operated.

It is a time chart which shows the control mode at the time of the overload operation control of the refrigerator-freezer which concerns on this invention. It is a vertical sectional side view which shows the schematic structure of the freezing refrigerator which concerns on this invention. It is explanatory drawing which conceptually shows the schematic structure of the 1st and 2nd refrigerating cycles constituting the freezing refrigerator which concerns on this invention. It is a cross-sectional plan view of the centralized condenser which constitutes the freezing refrigerator which concerns on this invention. It is a time chart which shows the control mode at the time of the normal operation control of a freezer / refrigerator. It is a flowchart which shows the control mode at the time of the normal operation control of a freezer / refrigerator. It is a time chart which shows the control mode at the time of the normal operation control of a freezer / refrigerator. It is a flowchart which shows the control mode at the time of the overload operation control of a freezer / refrigerator.

(Examples) FIGS. 1 to 8 show examples in which the refrigerator / freezer according to the present invention is applied to a reach-in type showcase. The front / rear, left / right, and up / down in the present invention follow the crossing arrows shown in FIGS. 2 and 4 and the front / rear, left / right, and up / down indications shown in the vicinity of each arrow. As shown in FIG. 2, the reach-in type showcase includes a main body case 1 made of a heat insulating box body, and the inside of the main body case 1 is a storage chamber 3 provided with a multi-stage shelf body 2. By opening and closing the slide door 4 provided on the front surface of the storage chamber 3, a storage object such as food or beverage can be taken in and out. Inside the machine room 5 partitioned under the main body case 1, a main part of a freezing / refrigerating device for cooling the inside of the storage room 3 to a constant temperature is housed. Further, the upper part of the storage chamber 3 is partitioned by a duct 6 as a heat exchange portion, and a part of the freezing / refrigerating device is also arranged inside the duct 6.

In FIG. 3, the refrigerating / refrigerating apparatus includes two refrigerating cycles, a first refrigerating cycle 11 and a second refrigerating cycle 12. In the first refrigeration cycle 11, the compressor 14, the condenser 15, the dryer 16, the expander 17, the evaporator 18, and the accumulator 19 driven by the motor 13 are connected in a loop by the refrigerant pipe 20. It is composed. Similarly, in the second refrigeration cycle 12, the compressor 24 driven by the motor 23, the condenser 25, the dryer 26, the expander 27, the evaporator 28, and the accumulator 29 are looped by the refrigerant pipe 30. It is configured by connecting. In FIG. 3, reference numeral 31 is a control device for controlling the operating state of each refrigeration cycle 11 and 12, and the control device 31 is a display device inside a control box (not shown) provided on the front surface of the machine room 5. Is housed with.

The condenser 15 of the first refrigeration cycle 11 and the condenser 25 of the second refrigeration cycle 12 are configured as one centralized condenser 33, and the main body case 1 is provided together with the compressors 14 and 24 of the refrigeration cycles 11 and 12. It is arranged in the machine room 5 of. In FIG. 4, the centralized condenser 33 includes a casing 34 whose vertical cross section is fixed to the bottom wall of the machine room 5 on the gate side, and a wind guide 35 fixed to the rear surface of the casing 34, inside the casing 34. The fin group 36 is arranged, and the condenser tube groups 37 and 38 of each refrigeration cycle 11 and 12 are folded back and arranged in the fin group 36 to share the fin group 36. Further, one condenser fan 39 for supplying cooling air to the fin group 36 and the condenser pipe groups 37 and 38 is arranged inside the air guide 35. Outlet tube temperature sensors (temperature sensors) 41.42 that detect the outlet tube temperature of each condenser 15/25 are arranged on the outer surface of the outlet tube portion of the condensing tube group 37/38 of each refrigeration cycle 11/12. (See Fig. 3). The temperature sensors 41 and 42 do not have to be sensors that detect the temperature of the outlet pipe, and may be, for example, a sensor that detects a temperature between the inlet pipe portion and the outlet pipe portion. In short, the condenser 15・ A sensor that can detect the temperature of 25 is sufficient.

While the first refrigeration cycle 11 is operated as the main refrigeration cycle, the second refrigeration cycle 12 keeps the temperature inside the storage chamber 3 (internal temperature) below a predetermined temperature only by the first refrigeration cycle 11. It is operated when it cannot be maintained. Therefore, the operating frequency of the compressor 14 in the first refrigerating cycle 11 is sufficiently higher than the operating frequency of the compressor 24 in the second refrigerating cycle 12, and the higher the heat exchange efficiency of the former condenser 15, the higher the operating frequency of the first refrigerating cycle 11. Can be operated efficiently. In this embodiment, in order to increase the heat exchange efficiency of the condenser 15 of the first refrigeration cycle 11, the condenser tube group 37 of the first refrigeration cycle 11 is arranged in the central region of the aggregate condenser 33 in a plan view to condense. The condenser tube group 38 of the second refrigeration cycle 12 is arranged between the tube group 37 and the left and right side walls of the casing 34, that is, in the peripheral region of the centralized condenser 33. Further, the refrigerating capacity of the first refrigerating cycle 11 and the refrigerating capacity of the second refrigerating cycle 12 are the same, or the refrigerating capacity of the latter is set to be slightly larger than the refrigerating capacity of the former, and the refrigerating capacity of the first refrigerating cycle 11 is set. The lack of refrigerating capacity can be quickly replenished with the refrigerating capacity of the second refrigeration cycle 12.

When the compressor 24 of the second refrigeration cycle 12 is stopped, the refrigerant liquid is not supplied to the condensing tube group 38 of the same cycle 12, so that the condensing tube group 37 and the tube group 37 of the first refrigeration cycle 11 The heat exchange efficiency in the condenser 15 of the first refrigeration cycle 11 can be increased by bringing new cooling air into contact with the fin group 36 having a large area located around the. Further, the higher the heat exchange efficiency of the condenser 15, the more efficiently the first refrigeration cycle 11 can be operated.

The evaporator 18 of the first refrigeration cycle 11 and the evaporator 28 of the second refrigeration cycle 12 are configured as one aggregate evaporator 45 and arranged inside the duct 6 in the same manner as the above-mentioned aggregate condenser 33. .. The integrated evaporator 45 is provided in the fin group 46, the evaporation pipe groups 47 and 48 of the refrigeration cycles 11 and 12 arranged folded back in the fin group 46, and the duct 6 to circulate the air in the storage chamber 3. It is equipped with a vessel fan 49. A suction port 50 for the evaporator fan 49 is opened in the front portion of the bottom wall of the duct 6, and a supply port for supplying cold air after heat exchange into the storage chamber 3 in the rear portion of the duct 6. 51 is open. The evaporator fan 49 composed of an axial fan is provided facing the suction port 50, pressurizes the air in the storage chamber 3, and supplies the air toward the ceiling wall of the duct 6. An internal temperature sensor 52 is arranged in the suction air region between the evaporator fan 49 and the fin group 46 of the centralized evaporator 45.

As described above, the operation frequency of the first refrigeration cycle 11 is sufficiently higher than the operation frequency of the second refrigeration cycle 12, so that the first refrigeration in the state where the compressor 24 of the second refrigeration cycle 12 is stopped is stopped. The higher the heat exchange efficiency of the evaporator 18 in cycle 11, the more efficiently the first refrigeration cycle 11 can be operated. In this way, in order to increase the heat exchange efficiency of the evaporator 18 of the first refrigeration cycle 11, in the integrated evaporator 45, the evaporation tube group 47 of the first refrigeration cycle 11 is arranged in the upper half of the fin group 46. , The evaporation tube group 48 of the second refrigeration cycle 12 is arranged below the evaporation tube group 47. As described above, the evaporator fan 49 supplies the air in the storage chamber 3 toward the ceiling wall of the duct 6, and the pressurized air that collides with the ceiling wall of the duct 6 is the ceiling wall of the duct 6. Tends to flow along. Therefore, a large amount of pressurized air can be brought into contact with the evaporation tube group 47 and the fin group 46 on the upper half side of the first refrigeration cycle 11 to effectively exchange heat, and the evaporator 18 of the first refrigeration cycle 11 can perform heat exchange effectively. The heat exchange efficiency of the

In the steady state, the control device 31 performs normal operation control for controlling the operating states of the compressors 14 and 24 of both refrigeration cycles 11 and 12, and maintains the temperature inside the refrigerator within the set temperature range. However, when the usage conditions and environmental conditions of the reach-in type showcase deteriorate and the possibility that the compressor 14 falls into an overload state becomes high, overload operation control is performed to prevent the temperature inside the refrigerator from rising. At the same time, the temperature of the refrigerant liquid is lowered to restore the normal operating state.

FIG. 5 shows a time chart during normal operation control, and FIG. 6 shows a control flow during normal operation control. In the normal operation control, the compressors 14 and 24 of each refrigeration cycle 11 and 12 are operated or stopped based on the first operation control and the second operation control.
In the first operation control, the compressors 14 and 24 of each refrigeration cycle 11 and 12 are operated and stopped based on the internal temperature of the storage chamber 3 detected by the internal temperature sensor 52, and the internal temperature is set as the set temperature. Keep within range. The temperature conditions for starting / stopping the compressor 14 in the first refrigeration cycle 11 and the temperature conditions for starting / stopping the compressor 24 in the second refrigeration cycle 12 are different. The operation is started at the upper limit temperature Dn1 shown in FIG. 5 and stopped at the lower limit temperature Df1. Further, the compressor 24 of the second refrigeration cycle 12 starts the operation at the upper limit temperature Dn2 and stops the operation at the lower limit temperature Df2.

The lower limit temperature Df1 of the first refrigeration cycle 11 is set lower than the lower limit temperature Df2 of the second refrigeration cycle 12. Further, the upper limit temperature Dn1 of the first refrigeration cycle 11 is set lower than the upper limit temperature Dn2 of the second refrigeration cycle 12 and higher than the lower limit temperature Df2 of the second refrigeration cycle. Therefore, the temperature region of the internal temperature when the compressor 24 of the second refrigeration cycle 12 is operated is higher than the temperature region of the internal temperature when the compressor 14 of the first refrigeration cycle 11 is operated. It has become. According to such a reach-in type showcase, when the temperature inside the refrigerator exceeds the refrigerating capacity of the first refrigerating cycle 11, the compressor 24 of the second refrigerating cycle 12 is operated to reduce the refrigerating capacity of the first refrigerating cycle 11. You can make up for the shortage. Further, when the temperature inside the refrigerator drops to the lower limit temperature Df2 of the second refrigeration cycle, the operation of the compressor 24 of the second refrigeration cycle 12 can be stopped to shorten the operation time of the compressor 24.

In the second operation control, the compressor of each refrigeration cycle 11/12 is based on the outlet pipe temperature (refrigerant liquid temperature) of the condensers 15 and 25 detected by the outlet pipe temperature sensors 41 and 42 of each refrigeration cycle 11/12. The operation and stop of 14 and 24 are performed to prevent the compressor 14 and 24 from falling into an overloaded state. The temperature conditions for starting / stopping the compressor 14 in the first refrigeration cycle 11 and the temperature conditions for starting / stopping the compressor 24 in the second refrigeration cycle 12 are different. As shown in FIG. 7, the compressor 14 of the first refrigeration cycle 11 starts operation when the outlet pipe temperature of the condenser 15 drops to the outlet lower limit temperature Rn1, and stops operation when the outlet upper limit temperature Rf1 rises. Further, the compressor 24 of the second refrigeration cycle 12 starts operation when the outlet pipe temperature of the condenser 25 drops to the outlet lower limit temperature Rn2, and stops operation when the outlet upper limit temperature Rf2 rises. The second operation control is executed in preference to the first operation control, and the outlet pipe temperature of the condensers 15 and 25 reaches the above set temperatures Rn1, Rn2, Rf1 and Rf2 regardless of the temperature inside the refrigerator. At that point, the compressors 14 and 24 are started or stopped.

The outlet upper limit temperature Rf1 of the outlet pipe temperature of the condenser 15 in the first refrigeration cycle 11 is set higher than the outlet upper limit temperature Rf2 of the outlet pipe temperature of the condenser 25 in the second refrigeration cycle 12. The outlet lower limit temperature Rn1 of the outlet tube temperature of the condenser 15 in the first refrigeration cycle 11 is higher than the outlet lower limit temperature Rn2 of the outlet tube temperature of the condenser 25 in the second refrigeration cycle 12, and the condenser in the second refrigeration cycle 12 The outlet pipe temperature of 25 is set lower than the outlet upper limit temperature Rf2. Therefore, the temperature range of the outlet pipe temperature of the condenser 25 when the compressor 24 of the second refrigeration cycle 12 is operated is the outlet pipe of the condenser 25 when the compressor 14 of the first refrigeration cycle 11 is operated. The temperature range is lower than the temperature range of the temperature.

As described above, when the compressor 24 of the second refrigeration cycle 12 is operated in the temperature region where the outlet pipe temperature is lower and the compressor 14 of the first refrigeration cycle 11 is operated in the temperature region where the outlet pipe temperature is higher, the first 2 The operation frequency of the compressor 24 in the refrigeration cycle 12 can be reduced. For example, in a time zone in which the sliding door 4 is opened and closed infrequently and the fluctuation of the temperature inside the refrigerator is small, in most cases, the temperature inside the refrigerator can be set within the set temperature range simply by operating and stopping the compressor 14 of the first refrigeration cycle 11. Since it can be maintained inside, it can contribute to energy saving.

As shown in FIG. 6, the control device 31 in the first operation control determines whether or not the temperature inside the refrigerator (temperature signal) sent from the temperature sensor 52 inside the refrigerator is within the set temperature range, and determines whether or not the temperature inside the refrigerator is within the set temperature range. When the temperature reaches the upper limit temperature Dn1 of the first refrigeration cycle 11 (YES in S1), the compressor 14 of the first refrigeration cycle 11 is started (S2). If the temperature inside the refrigerator is less than the upper limit temperature Dn1 of the first refrigeration cycle 11 (NO in S1), the temperature returns to S1. After that, when the temperature inside the refrigerator drops and the temperature inside the refrigerator reaches the lower limit temperature Df1 of the first refrigeration cycle 11 (YES in S3), the compressor 14 in the first refrigeration cycle 11 is stopped (S4) and returns to S1. .. On the other hand, when the temperature inside the refrigerator rises (NO in S3) despite starting the compressor 14 in the first refrigeration cycle 11, and the temperature inside the refrigerator reaches the upper limit temperature Dn2 of the second refrigeration cycle 12 (in S5). YES), the compressor 24 of the second refrigeration cycle 12 is started (S6). In this state, since the compressors 14 and 24 of both refrigeration cycles 11 and 12 are driven, a larger amount of refrigerant liquid can be circulated and the temperature inside the refrigerator can be lowered within the set temperature range. In S5, when the temperature inside the refrigerator does not reach the upper limit temperature Dn2 of the second refrigeration cycle 12 (NO in S5), the temperature returns to S3.

When the temperature inside the refrigerator drops and the temperature inside the refrigerator reaches the lower limit temperature Df2 of the second refrigeration cycle 12 (YES in S7), the compressor 24 of the second refrigeration cycle 12 is stopped (S8) and returns to S3. The inside of the storage chamber 3 is cooled only by the compressor 14 of the first refrigeration cycle 11. After the execution of S6, the compressors 14 and 24 of both refrigeration cycles 11 and 12 are driven, but the internal temperature is the lower limit temperature Df2 of the second refrigeration cycle 12 due to frequent opening and closing of the slide door 4. If the temperature becomes higher (NO in S7), the compressors 14 and 24 of both refrigeration cycles 11 and 12 may be overloaded. Therefore, the outlet pipe temperature of the condenser 15 in the first refrigeration cycle 11 is detected by the outlet pipe temperature sensor 41, and it is determined whether or not the detected temperature exceeds the upper limit load temperature RL described later (S9) to condense. When the outlet pipe temperature of the vessel 15 exceeds the upper limit load temperature RL (YES in S9), the overload operation control is performed. Further, when the outlet tube temperature of the condenser 15 is lower than the upper limit load temperature RL (NO in S9), the temperature returns to S7. The upper limit load temperature RL in this embodiment was matched with the outlet upper limit temperature Rf2 (for example, 55 ° C.) of the condenser 25 in the second refrigeration cycle 12 when the compressor 24 in the second refrigeration cycle 12 was turned off. The upper limit load temperature RL may be set lower than the outlet upper limit temperature Rf2 of the condenser 25.

In FIG. 8, the control device 31 at the time of overload operation control stops the compressor 24 of the second refrigeration cycle 12 (S11), and continues the operation of the first refrigeration cycle 11. In this state, the compressor 14 of the first refrigeration cycle 11 is operated, and only the condensing tube group 37 of the first refrigeration cycle 11 is cooled by the centralized condenser 33, so that the high-temperature condensed refrigerant passing through the condensing tube group 37 The liquid can be cooled effectively. That is, since only about half the amount of the condensed refrigerant liquid flows through the condenser tube group 37 with respect to the heat exchange capacity of the centralized condenser 33, the condensed refrigerant liquid is effectively cooled, and the first The outlet tube temperature of the condenser 15 in the refrigeration cycle 11 can be effectively lowered. If the outlet pipe temperature of the condenser 25 of the second refrigeration cycle 12 drops to the outlet lower limit temperature Rn2 (YES in S12) after the compressor 24 of the second refrigeration cycle 12 is stopped, the second refrigeration cycle 12 The operation of the compressor 24 of the above is resumed (S13). However, after the compressor 24 of the second refrigeration cycle 12 is stopped, if the outlet pipe temperature of the condenser 15 of the first refrigeration cycle 11 is higher than the outlet lower limit temperature Rn2 (NO in S12), the temperature is returned to S12.

After restarting the operation of the compressor 24 in the second refrigeration cycle 12, when the outlet pipe temperature of the condenser 15 in the first refrigeration cycle 11 reaches the upper limit load temperature RL (YES in S14), it returns to S11 and the second The compressor 24 of the refrigeration cycle 12 is stopped. Further, after restarting the operation of the compressor 24 of the second refrigeration cycle 12, if the outlet pipe temperature of the condenser 15 of the first refrigeration cycle 11 has not reached the upper limit load temperature RL (NO in S14), the process proceeds to S15. After the transition, it is determined whether or not the outlet pipe temperature of the condenser 15 in the first refrigeration cycle 11 has dropped to the lower limit load temperature RM. When the outlet pipe temperature of the condenser 15 in the first refrigeration cycle 11 drops to the lower limit load temperature RM (YES in S15), the compressor 24 in the second refrigeration cycle 12 is stopped (S16), and overload operation is performed. The control is terminated, and the process returns to S3 of the normal operation control. If the outlet tube temperature of the condenser 15 in the first refrigeration cycle 11 has not dropped to the lower limit load temperature RM (NO in S15), the temperature returns to S14. The lower limit load temperature RM in this embodiment was matched with the outlet lower limit temperature Rn2 (for example, 45 ° C.) of the condenser 25 in the second refrigeration cycle 12 when the compressor 24 in the second refrigeration cycle 12 was turned on. The lower limit load temperature RM may be set higher than the outlet lower limit temperature Rn2 of the condenser 25.

In the showcase configured as described above, in the state of shifting from the normal operation control to the overload operation control, the operation of the compressor 24 of the second refrigeration cycle 12 is stopped, and the compressor 24 of the first refrigeration cycle 11 is stopped. I tried to continue driving. According to such a showcase, while cooling the storage chamber 3 in the first refrigeration cycle 11, the high-temperature refrigerant liquid in the first refrigeration cycle 11 is effectively cooled by the condensing condenser 33, and the first refrigeration cycle 11 The outlet tube temperature of the condenser 15 can be lowered in a shorter time. This is because the centralized condenser 33 in the state where the operation of the compressor 24 of the second refrigerating cycle 12 is stopped only needs to cool the refrigerant liquid of the first refrigerating cycle 11, so that the condenser 15 of the first refrigerating cycle 11 needs to be cooled. This is because the high-temperature refrigerant liquid can be effectively cooled by the centralized condenser 33 as compared with the case where is provided alone. Further, since the outlet pipe temperature sensor 41 detects the outlet pipe temperature of the condenser 15 and performs overload operation control, the temperature sensor detects the air temperature in the refrigerator afterwards to detect the inverter compressor and the constant speed compressor. This is because the overload operation control can be completed in a shorter time by immediately detecting the outlet pipe temperature as compared with the conventional device that performs the overload operation control.

Further, the compressor 14 can be operated normally in a shorter time than the overload countermeasure in which a part of the refrigerant discharged from the compressor is supplied to the refrigerant pipe on the indoor heat exchanger side via the bypass path. It is possible to prevent the temperature inside the refrigerator from rising while restoring the state. Therefore, it is possible to prevent deterioration of freshness and quality of foods and the like stored in the refrigerator while contributing to energy saving as much as the time required for the compressor 14 to recover to the normal operating state is short.

In the above embodiment, the condensing tube group 37 of the first refrigeration cycle 11 is arranged in the central region of the condensing condenser 33, and the condensing tube group 38 of the second refrigeration cycle 12 is arranged in the peripheral region of the condensing condenser 33. That is not needed. For example, the condenser tube groups 37 and 38 of both refrigeration cycles 11 and 12 may be arranged alternately in the middle of the fin group 36. Even in such a case, since the area of the fin group 36 for cooling the condenser tube group 37 of the first refrigeration cycle 11 is large, the first refrigeration cycle is compared with the case where the condenser 15 of the first refrigeration cycle 11 is provided alone. The refrigerant liquid of 11 can be effectively cooled.

The refrigerator / freezer according to the present invention can be applied to a refrigerator having a refrigerator compartment and a freezer compartment in addition to the reach-in type showcase. In that case, the refrigerant liquid cooled by the centralized condenser 33 is supplied to the centralized evaporator for the refrigerating room and the centralized evaporator for the freezing room, and the operating states of the first refrigerating cycle 11 and the second refrigerating cycle 12 are performed. It is good to control.

3 Storage chamber 6 Duct 11 1st refrigeration cycle 12 2nd refrigeration cycle 14.24 Compressor 15.25 Condenser 18.28 Evaporator 31 Control device 33 Condensed condenser 37 Condensation tube group 38 2nd refrigeration of 1st refrigeration cycle Cycle Condensing Tube Group 41 Temperature Sensor for First Refrigeration Cycle (Outlet Tube Temperature Sensor)
45 Aggregate evaporator RL Upper limit load temperature RM Lower limit load temperature

Claims (3)

A first refrigeration cycle (11) including a compressor (14), a condenser (15), an expander (17) and an evaporator (18), and a compressor (24), a condenser (25), an expander (27). ) And a second refrigerating cycle (12) including an evaporator (28), and a refrigerating / refrigerator provided with a control device (31) for controlling the operating state of these refrigerating cycles (11/12).
The condenser (15) of the first refrigeration cycle (11) and the condenser (25) of the second refrigeration cycle (12) are configured as one aggregate condenser (33) and share the fin group (36). Ori,
The control device (31) determines the operating state of the compressors (14/24) of both refrigeration cycles (11/12) based on the detection result of the internal temperature sensor (52) that detects the temperature of the storage chamber (3). Based on the normal operation control to be controlled and the detection result of the temperature sensor (41) that detects the temperature of the condenser (15) of the first refrigeration cycle (11), the compressors (14. The overload operation control that controls the operation state of 24) is performed.
In the normal operation control, the compressor (14/24) of each refrigeration cycle (11/12) is operated or stopped based on the first operation control and the second operation control.
In the first operation control, the compressor (14) of the first refrigeration cycle (11) is started to operate at the upper limit temperature (Dn1) of the internal temperature detected by the internal temperature sensor (52), and the lower limit temperature (Dn1) is started. The operation is stopped at Df1),
In the second operation control, the compressor (14) of the first refrigeration cycle (11) starts operation when the temperature of the condenser (15) of the first refrigeration cycle (11) drops to the lower limit temperature (Rn1). , When the temperature rises to the upper limit temperature (Rf1), the operation is stopped.
In the second operation control, the compressor (24) of the second refrigeration cycle (12) starts operation when the temperature of the condenser (25) of the second refrigeration cycle (12) drops to the lower limit temperature (Rn2). , When the temperature rises to the upper limit temperature (Rf2), the operation is stopped.
During normal operation control in which the compressors (14 and 24) of both refrigeration cycles (11 and 12) are operated at the same time, the temperature of the condenser (15) of the first refrigeration cycle (11) is equal to or higher than the upper limit load temperature (RL). The overload operation control is performed in the state where the temperature sensor (41) detects that the temperature is high.
In the overload operation control, the operation of the compressor (24) of the second refrigeration cycle (12) is stopped, and only the compressor (14) of the first refrigeration cycle (11) is operated to operate the first refrigeration cycle (1). The refrigerant liquid of the condenser (15) of 11) is cooled by the centralized condenser (33).
In the state where the temperature sensor (42) detects that the temperature of the condenser (25) of the second refrigeration cycle (12) has dropped to the lower limit temperature (Rn2) during the overload operation control, the second refrigeration cycle (12) The operation of the compressor (24) of
During overload operation control in which the compressors (14.24) of both refrigeration cycles (11/12) are operated, the temperature of the condenser (15) of the first refrigeration cycle (11) is the lower limit load temperature (RM). in a state where the temperature sensor (41) detects that at most, that the stop operation of the second refrigerant cycle (12) of the compressor (24) is configured to return to the normal operation control A featured refrigerator / freezer. The aggregate condenser (33) includes a fin group (36), a condensing tube group (37.38) of each refrigeration cycle (11.12) arranged folded back in the fin group (36), a fin group (36), and a condensate. It is equipped with a condenser fan (39) that supplies cooling air to the tube group (37.38).
The condensing tube group (37) of the first refrigerating cycle (11) is arranged in the central region of the condensing condenser (33) in a plan view, and the condensing tube group (37) of the first refrigerating cycle (11) is arranged in the peripheral region of the condensing condenser (33). The freezer / refrigerator according to claim 1, wherein the condenser tube group (38) is arranged. The evaporator (18) of the first refrigeration cycle (11) and the evaporator (28) of the second refrigeration cycle (12) are configured as one aggregate evaporator (45), and the storage chamber of the main body case (1). (3) It is located in the upper duct (6) and
The integrated evaporator (45) is provided in the fin group (46), the evaporation pipe group (47.48) of each refrigeration cycle (11/12) arranged folded back in the fin group (46), and the duct (6). It is equipped with an evaporator fan (49) that feeds the air in the storage chamber (3) toward the ceiling wall of the duct (6).
The evaporation tube group (47) of the first refrigeration cycle (11) is arranged in the upper half of the fin group (46), and the evaporation tube group (12) of the second refrigeration cycle (12) is arranged below the evaporation tube group (47). The refrigerator / freezer according to claim 1 or 2, wherein 48) is arranged.

Images