JP2000121232A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerator having a defrosting system in which a safety characteristic at the time of using ignitable refrigerant can be improved and a storing space of the refrigerator can be expanded. SOLUTION: This refrigerator is comprised of a cooling circuit 36 including a compressor 29, a condenser 31, a first flow passage control means 34 for use in feeding refrigerant to either one of a first pressure reducing means 32 or second pressure reducing means 33, a first evaporator 25 for evaporating and gasifying liquefied refrigerant fed from the pressure reducing means, a second evaporator 27 and a second flow passage control means 35 installed after the second evaporator 27; and a defrosting circuit 38 constructed by a third flow passage control means 37 for use in flowing high temperature gas to the second evaporator 27 during a defrosting operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having a cooling system for cooling a first compartment having a relatively high temperature and a second compartment having a relatively low temperature independently or simultaneously using a combustible refrigerant. It relates to defrosting.

[0002]

2. Description of the Related Art A general conventional refrigerator will be described below.
This will be described with reference to FIGS. 7 is a cross-sectional view showing the structure around the evaporator of the conventional refrigerator, FIG. 8 is an explanatory diagram of a refrigeration cycle of the conventional refrigerator, and FIG. 9 is a time chart of defrost control of the evaporator of the conventional refrigerator. FIG.

In FIG. 7, reference numeral 1 denotes an evaporator, 2 denotes a defrost heater, 3 denotes a defrosting end detecting sensor, 4 denotes a fan motor for circulating cool air, and 5 denotes a cold air adjusting damper discharged from a refrigerator compartment.

In FIG. 8, 1 is an evaporator, 8 is a compressor,
9 is a condenser, 10 is a dryer, 11 is a capillary tube which is a throttle device, ie, a pressure reducing device, and 12 is a suction pipe of a suction pipe.

In FIG. 9, during normal cooling operation, the compressor 8 and the cooling circulation fan motor 4 are controlled to operate synchronously.

Generally, when the accumulated operation time of the compressor 8 reaches a set time, defrosting is started. In the defrosting, the defrost heater 2 is energized at the same time as the stop of the compressor 8 and the stop of the cooling circulation fan motor 4, and the evaporator 1 is heated by the defrost heater 2. When the attached frost melts, the temperature of the evaporator 1 rises. When the temperature of the evaporator 1 rises and the defrosting end detection sensor 3 attached near the evaporator 1 reaches a set temperature, the defrost heater 2 is turned off.

After the defrosting, the temperature of the evaporator 1 is about 20 ° C., and the evaporating pressure has risen to about 4 to 5 kgf / cm ² abs. Becomes

Generally, the defrost heater 2 is turned off.
Thereafter, a time safe time of several minutes is provided to reduce the evaporation pressure.

A conventional refrigerator defrosting method is disclosed in Japanese Patent Application Laid-Open No. H10-160327.

Hereinafter, the above-described conventional defrosting method will be described with reference to the drawings. FIG. 10 is an explanatory diagram of a refrigeration cycle of a refrigerator according to a conventional example, and FIG. 11 is an explanatory diagram of a time chart of evaporator defrosting control of the refrigerator according to the conventional example.

As shown in FIG. 10, a refrigerator according to a conventional form has a compressor 8 for compressing a refrigerant, a condenser 9 for liquefying a gas refrigerant, and a tightening device for controlling the pressure reduction and the amount of circulating refrigerant. That is, it has a capillary tube 11 which is a decompression device, an evaporator 7 for evaporating and gasifying the liquid refrigerant, and a refrigeration cycle configured by connecting each with a piping pipe. A cooling air circulation fan motor 13 to be replaced and a defrost heater 14 of the evaporator 7
And a defrosting end detecting thermistor 15 for detecting the end of defrosting by temperature, and a control device 16 for controlling the compressor 8, the cooling air circulation fan motor 13, and the defrosting heater 14.

In the defrosting control of the evaporator 7 by the control device 16, as shown in FIG. 2, when the integrated operation of the compressor 8 reaches a set time, the compressor 8 is stopped. At this time, the high-pressure liquid refrigerant accumulated in the condenser 9 during the operation of the compressor 8 is turned into a gas after the compressor 8 is stopped, flows into the evaporator 7, and radiates heat in the evaporator 7 to condense. The evaporator 7 is defrosted by the latent heat of condensation. Since the condensation process in the evaporator 7 is completed in a few minutes, the defrost heater 14 is energized to perform normal defrosting thereafter. Thus, the energization time of the large-capacity defrost heater 14 for defrosting the evaporator 7 can be reduced, and low power consumption can be realized.

[0013]

However, in the above-mentioned conventional configuration, a method of defrosting a refrigerator having an independent evaporator in at least two sections is not defined.
A defrost heater, which is one of the factors that increase the power consumption of the refrigerator, is used. Further, when a flammable refrigerant such as R600a is used, if the flammable refrigerant leaks, there is a risk of ignition by the defrost heater.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides a system for defrosting a cooling system that performs independent or simultaneous cooling of a first section and a second section, and a system for defrosting. An object of the present invention is to provide a refrigerator capable of improving safety when using a flammable refrigerant by not using a heater in particular and expanding a storage space.

[0015]

To achieve the above object, the present invention has the following arrangement. The refrigerator according to claim 1 of the present invention is configured by a compartment for performing temperature control in at least two different temperature zones, and has a first compartment having a relatively high temperature and a second compartment having a relatively low temperature. Wherein a first evaporator is provided in the first section and a second evaporator is provided in the second section, and a compressor, a condenser, a first flow path control means, and a first decompression device are provided. A device for sequentially connecting the first evaporator via a means and cooling the two sections independently of the second evaporator in parallel with the first evaporator through a second decompression means. A defrosting flow path provided between the compressor and the condenser to allow the high-temperature gas refrigerant discharged from the compressor to flow into the second evaporator at the time of defrosting. Flow path control means and a first flow path for securing a flow path from the second evaporator to the first evaporator at the time of defrosting. The control means includes a cooling circuit for the first evaporator, a cooling circuit for the second evaporator, and a flow control means which can be switched in three directions of a defrosting circuit, and a control means for controlling them. And a second evaporator is used to defrost the second evaporator.

A refrigerator according to a second aspect of the present invention comprises a compartment for controlling the temperature in at least two different temperature zones, and a first compartment having a relatively high temperature and a second compartment having a relatively low temperature. A refrigerator box having a first evaporator in the first compartment and a second evaporator in the second compartment, and a compressor for controlling a cooling circuit and a defrost circuit. The first evaporator via a flow path control unit, a condenser and a first decompression unit are sequentially connected, and the second evaporator via a second decompression unit is connected to the first evaporator. Connected in parallel, a second flow path control means and a third flow path control means for controlling respective flow paths on the outlet side of the first evaporator and the outlet side of the second evaporator are provided. In a refrigerator provided with a device for independently cooling the first compartment and the second compartment, the high-temperature gas refrigerant discharged from the compressor during defrosting In order to flow into the second evaporator, the first flow path control means and the defrosting flow path provided between the compressor and the condenser provide a defrosting circuit to the second evaporator during defrosting. A refrigerator using a flammable refrigerant, comprising a control means for causing a high-temperature gas refrigerant to flow.

Further, according to a third aspect of the present invention, there is provided a refrigerator according to any one of the first and second aspects, wherein the second flow path control means and the third flow path control means are combined into one. A refrigerator comprising a road control means.

Furthermore, a refrigerator according to a fourth aspect of the present invention is the refrigerator according to any one of the first to third aspects, wherein the cooling circuit of the first evaporator, the cooling circuit of the second evaporator, and the defroster are provided. A refrigerator characterized in that the first flow path control means switchable in three directions of the circuit is replaced with three flow path control means.

Furthermore, in the refrigerator according to the fifth aspect of the present invention, in the refrigerator according to any one of the first to fourth aspects, a flow path from the second evaporator to the first evaporator is secured during defrosting. Rather, a new second defroster is installed in a location different from the first defrost circuit between the compressor and the condenser, between the flow path control means for securing the flow from the second evaporator to the condenser. A refrigerator comprising a circuit and a flow path control means.

[0020] In addition, the refrigerator according to claim 6 of the present invention is the refrigerator according to any one of claims 1 to 5, wherein the branch of the first defrost circuit between the compressor and the condenser is connected to the second branch. A refrigerator characterized by comprising new flow path control means that integrates flow path control means of a defrost circuit into one.

In addition, the refrigerator according to claim 7 of the present invention is the refrigerator according to any one of claims 1 to 6, wherein a fan for an evaporator and a condenser for promoting cooling of the first section and the second section are provided. The operation of the fan is a refrigerator provided with a control circuit for stopping the evaporator fan and the condensing fan during defrosting.

In addition, the refrigerator according to claim 8 of the present invention is the refrigerator according to any one of claims 1 to 6, wherein the fan for the evaporator and the condenser for facilitating the cooling of the first section and the second section. During the defrosting, the first evaporator fan is operated or stopped in the mode determined by the internal temperature detection means during defrosting, and the second evaporator fan and the condensing fan are provided with a control circuit for stopping. It is a refrigerator.

According to the above configuration, in the refrigerator according to the first aspect of the present invention, the first section and the second section can be cooled independently during the cooling operation. It is possible to prevent backflow with respect to the flow from the first evaporator to the compressor by the later flow path control means. Further, the high-temperature gas discharged from the compressor at the time of defrost is passed through the flow path control means in the defrost circuit, the flow path control means after the second evaporator, and the flow path control means after the condenser. By flowing the high-temperature gas into the second evaporator, defrosting of the second evaporator can be performed without using a defrost heater. Further, the gas that has passed through the second evaporator is converted from the second pressure reducing means to the first pressure reducing means,
In the first section having a relatively high temperature, which flows with the first evaporator, the cooling operation can be performed regardless of the defrosting operation in the second section.

Further, the refrigerator according to claim 2 of the present invention comprises:
During the cooling operation, the first section and the second section are independently cooled, but at the time of defrosting, the high-temperature gas discharged from the compressor is supplied to the first flow path control means between the compressor and the condenser. By flowing the high-temperature gaseous refrigerant into the second evaporator by the flow path control means after the first evaporator and after the second evaporator, the configuration of the refrigeration cycle is simplified, and the system can be manufactured at low cost. Can be configured.

Further, in the refrigerator according to the third aspect of the present invention, in the refrigerator according to any one of the first and second aspects, a flow control means provided after the second evaporator and a defroster for preventing backflow during a cooling operation. By integrating the flow path control means in the circuit or the flow path control means for controlling the flow path of the first evaporator into one unit, the number of parts can be reduced and the storage space can be reduced, which leads to an improvement in the storage capacity of the refrigerator. .

The refrigerator according to claim 4 of the present invention is the refrigerator according to any one of claims 1 to 3, wherein
A highly efficient defrosting system can be provided by a flow path control means that is technically simple without using a special flow path control means that can be directed.

In addition, the refrigerator according to the fifth aspect of the present invention is the refrigerator according to any one of the first to fourth aspects, wherein a flow path control means is provided separately from the defrost circuit between the compressor and the condenser. By providing a circuit that does not cool the first section by providing and providing a new defrosting circuit, it is possible to prevent overcooling of the first section at a relatively high temperature.

In addition, the refrigerator according to the sixth aspect of the present invention is the refrigerator according to any one of the first to fifth aspects, wherein a four-way valve is used as a flow path control means between the compressor and the condenser. The cooling system can be simplified, the number of parts can be reduced, and the refrigerator can be stored more easily.

In addition, the refrigerator according to claim 7 of the present invention is the refrigerator according to any one of claims 1 to 6, wherein the defrosting efficiency is reduced by stopping the fans of the evaporator and the condenser during defrosting. It is possible to improve and reduce power consumption.

[0030] In addition, the refrigerator according to claim 8 of the present invention is the refrigerator according to any one of claims 1 to 6, wherein the means for detecting the temperature inside the refrigerator in the first compartment is used for the first fan for the evaporator. By defining the operation, the temperature of the first section can be maintained at an appropriate temperature.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. Detailed descriptions of the same components as those of the conventional example are omitted, and the same reference numerals are given.

(Embodiment 1) FIG. 1 is a schematic diagram of a refrigerator according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a refrigeration cycle according to the embodiment.

As shown in FIG. 1, the refrigerator according to the present embodiment is a refrigerator box 21 having a first compartment 22 which is a relatively high temperature compartment in an upper portion and a first compartment 22 having a relatively low temperature in a lower portion. Two sections 23 are arranged, and are insulated from the surroundings by a heat insulating material such as urethane. Storage of foods and the like is carried out through an insulated door (not shown).

[0034] The first compartment 22 usually contains three compartments for refrigerated storage.
The temperature is set at about 5 ° C., but may be set at a slightly lower temperature, for example, 0 to −3 ° C., for the purpose of improving freshness. In some cases, it is possible to switch. In some cases, the temperature may be set slightly higher, for example, around 10 ° C., for freshening wine and root vegetables.

The second compartment 23 is usually used for cryopreservation.
The temperature is set at 18 to -22 ° C, but may be set at a lower temperature, for example, -25 to -30 ° C for improving freshness.

FIG. 2 is an explanatory diagram of a refrigeration cycle of the refrigerator according to the above embodiment. The compressor 29, the condenser 31 for liquefying the gas refrigerant, the first flow path control means 34 for sending the liquefied refrigerant to one of the first decompression means 32 and the second decompression means 33, and the respective decompression means A first evaporator 25 and a second evaporator 27 for evaporating and gasifying the sent liquefied refrigerant, and a second evaporator 27 for preventing the refrigerant from flowing back to the second evaporator 27 when the refrigerant is flowing through the first evaporator 25. The cooling circuit 36 constituted by the second flow path control means 35 provided after the second evaporator 27 and the high-temperature gas discharged from the compressor 29 to the second evaporator 27 during defrost FIG. 9 is a refrigeration cycle diagram configured by connecting a defrosting circuit 38 configured by third flow path control means 37 for flowing into an evaporator 27 and each of the circuits by a piping pipe.

As shown in FIG. 2, during the cooling operation, the compressor 2
The high-temperature gas discharged from 9 is sent to a condenser 31 for liquefying the refrigerant, and is supplied to a first flow path control means 34, for example, a pressure reducing means determined by an electric three-way valve capable of controlling a flow path in three directions, for example, a capillary tube or expansion. Supply refrigerant to the valve.
Then, the liquefied refrigerant cooled by the decompression means is sent to, for example, the first evaporator 25, and cools the inside of the refrigerator by evaporation and gasification. Secondly, when cooling the section 23, the refrigerant flows into the second evaporator 27, and the inside of the compartment is cooled by evaporation and gasification. Here, since the first section 22 has a relatively high temperature and high pressure compared to the second section 23, the refrigerant flowing from the first evaporator 25 to the compressor 29 when the first section 22 is cooled is cooled by the first section 22. There is a possibility that the refrigerant may flow into the second evaporator 27, and there is a concern that the cooling efficiency is reduced due to a decrease in the amount of circulating refrigerant. Therefore, by using the second flow path control means 35, for example, an electromagnetic valve after the outlet of the second evaporator 27, the backflow of the refrigerant is prevented and the cooling efficiency is prevented from lowering. At the time of defrosting, the high-temperature gas discharged from the compressor is passed from a defrosting circuit 38 provided between the compressor 29 and the condenser 31 through a third flow control means 37 for defrosting, for example, an electromagnetic valve. A high-temperature gas refrigerant is poured into the second evaporator 27 to perform defrosting by the heat. At this time, the second flow path control means 27 is closed and no refrigerant flows. The gasified refrigerant used for defrosting in the second evaporator 27 passes through the second pressure reducing means 33 and reaches the first flow path controlling means 34. The first flow path control means 34 is a flow control means capable of three directions, and at this time, a flow path through which the refrigerant flows from the second pressure reduction means 33 to the first pressure reduction means 32 is secured. By this process,
The refrigerant liquefies at a low temperature and flows into the first evaporator 25 to cool the first section 22. Then, the low-temperature refrigerant gas that has been gasified again returns to the compressor 29. Table 1 shows the operations of the compressor 29, the flow path control means 34, the flow path control means 35, and the flow path control means 37 during cooling and defrosting.

[0038]

[Table 1]

As described above, the refrigerator of this embodiment can cool two compartments independently when cooling.
Defrosting can be performed without using a large-capacity defrosting heater for defrosting during defrosting, which leads to a reduction in the number of parts and an increase in food storage volume.

A large-capacity defrosting heater usually rises to about 600 ° C. in the vicinity of the resistance wire. Therefore, when a flammable refrigerant, for example, R600a is used, ignition and ignition
Risk of explosion. Therefore, by using the present embodiment, when using a combustible refrigerant as the refrigerant, it is possible to safely defrost with the high-temperature gas of the refrigerant without using a defrost heater.

Further, the temperature of the refrigerant used in the defrost can be reduced by the decompression means, and the first section 22 and the evaporator 25 can be cooled while the second evaporator 27 is being defrosted. The internal temperature rise can be prevented.

In this embodiment, the arrangement of the second flow path control means 35 and the third flow path control means 37 prevents backflow during cooling and controls high-temperature gas refrigerant during defrosting. However, a single flow path control means such as an electric three-way valve may be used.

Further, in this embodiment, an electric three-way valve which secures a three-way flow path is used for the first flow path control means 34.
It may be arranged individually.

(Embodiment 2) FIG. 3 is a configuration diagram of a refrigeration cycle of a refrigerator according to this embodiment. The detailed description of the same configuration as the first embodiment is omitted,
The same reference numerals are given.

The compressor 29 and the defrosting circuit 38 or the condenser 31
Flow control means 3 for determining whether to send a high-temperature gas refrigerant to one side
9, a condenser 31 for liquefying the gas refrigerant, a first decompression means 32, a second decompression means 33, and a first evaporator 25 for evaporating and gasifying the liquefied refrigerant sent from the decompression means, and a second evaporation Refrigeration cycle, which is constituted by a second flow path control means 40 and a third flow path control means 41 which are respectively provided after the first evaporator 25 and the second evaporator 27 and control the respective flow paths. FIG. In addition, the compressor 29 at the time of cooling and defrosting,
Flow path control means 39, flow path control means 40, flow path control means 4
Table 2 shows the operation of No. 1.

[0046]

[Table 2]

FIG. 3 and Table 2 showing the operation of the compressor 29, the flow path control means 39, the flow path control means 40, and the flow path control means 41.
During the cooling operation, the high-temperature gas discharged from the compressor 29 is sent to the condenser 31 for liquefying the refrigerant by the first flow path control means 39, for example, the electric three-way valve. The liquefied refrigerant cooled by the respective decompression means is sent to the first evaporator 25 or the second evaporator 27, and cools the inside of the refrigerator by evaporation and gasification. At the time of defrosting, the high temperature gas discharged from the compressor 29 is transferred from the defrosting circuit 38 to the second evaporator 27 by the first flow path control means 39 provided between the compressor 29 and the condenser 31. A gas refrigerant is poured, and the heat is used to perform defrosting. At this time, the second flow path control means 40, for example, the electromagnetic valve is opened, and the third flow path control means 41, for example, the electromagnetic valve is closed. Then, the gasified refrigerant used for defrosting in the second evaporator 27 flows through the second pressure reducing means 33 to the first pressure reducing means 32. By this step, the refrigerant liquefies at a low temperature and flows into the first evaporator, where
To cool. Then, the low-temperature refrigerant gas that has been gasified again returns to the compressor 29.

As described above, in the refrigerator of this embodiment, when the second evaporator 27 is defrosted, the defrosting can be performed without using a large-capacity defrosting heater similarly to the first embodiment, and the number of parts can be reduced. , Leading to an increase in food storage capacity.

Further, by using a simple flow path control means, it is possible to simplify the control means and to provide a space-saving and low-cost flow path control.

In the present embodiment, the flow path control means is provided after each evaporator. However, it is also possible to arrange the flow control means integrally at the merging point on the outlet side of each evaporator. Good.

(Embodiment 3) FIG. 4 is a configuration diagram of a refrigeration cycle of a refrigerator according to this embodiment. The detailed description of the same components as those of the first and second embodiments is omitted, and the same reference numerals are given.

The first degassing means, which is constituted by third flow path control means 37 for causing the high-temperature gas discharged from the compressor 29 to flow into the second evaporator 27 at the time of defrosting, flows into the second evaporator 29. A fourth flow path control means 42 is arranged between the compressor and the condenser separately from the frost circuit 43, and a second defrost circuit 44 directly returns to the compressor from a branch point of the flow path control means 42. It is a refrigeration cycle diagram. In addition, the compressor 29 at the time of cooling and defrosting,
Flow path control means 34, flow path control means 35, flow path control means 3
7. The operation of the road control means 42 is shown in Table 3.

[0053]

[Table 3]

As shown in FIG. 4 and Table 3, at the time of defrosting, the high-temperature gas discharged from the compressor 29 is supplied to the first defrosting circuit 43 provided between the compressor 29 and the condenser 31 for defrosting. The third evaporator 27 is passed through a third flow path control means 37 such as an electromagnetic valve.
A high-temperature gaseous refrigerant is poured into the chiller to perform defrosting by the heat. At this time, the second flow path control means 35 is closed and the refrigerant does not flow. The gasified refrigerant used for defrosting in the second evaporator 27 passes through the second pressure reducing means 33 and reaches the first flow path controlling means 34. At this time, the first flow path control means 34 secures the flow to the condenser 31. By this step, the refrigerant is liquefied at a low temperature, flows into the condenser 31, and then reaches the fourth flow path control means 42. The fourth flow path control means 42 opens the defrost circuit 44 second, flows the refrigerant, and the gasified low-temperature refrigerant gas returns to the compressor 29.

As described above, the refrigerator of this embodiment can defrost the second section 23 without cooling the first section 22 during defrosting.

At the end of defrosting, the refrigerant tends to collect in the condenser 31, which leads to an improvement in the cooling speed of the evaporator during the recooling operation.

Furthermore, since the temperature of the condenser 31 is low, the temperature of the machine room of the refrigerator is low, and the operation can be performed with a small input during the recooling operation.

In the present embodiment, the branch of the defrosting circuit 44 between the fourth flow path control means 42, the compressor 29 and the fourth flow path control means 42 is performed by using a four-way valve. In addition, the piping configuration can be simplified, and the number of parts and man-hours can be reduced.

(Embodiment 4) FIG. 5 is a configuration diagram of a refrigeration cycle of a refrigerator according to this embodiment. The detailed description of the same configuration as the first to third embodiments is omitted, and the same reference numerals are given.

The refrigerating cycle of the refrigerator according to the present embodiment is similar to the first to third embodiments, and includes a first evaporator internal fan motor for facilitating the cooling of the first compartment and a cooling of the second compartment. And a condenser fan motor for improving the condensation capacity. Table 4 shows the operation of each component during cooling and defrosting.

[0061]

[Table 4]

Cooling of the compressor 29, the flow path control means 34, the flow path control means 35, the flow path control means 37, the first evaporator fan motor 26, the second evaporator fan motor 26, and the condenser fan motor 30. Table 4 shows the operation in the operation and the defrosting operation. During the cooling operation, each fan motor repeats the operation and the stop in the predetermined operation mode. However, the cooling of the first section 22 is performed during the defrosting. All of the first evaporator internal fan motor 26 for promoting the cooling, the second evaporator fan motor 28 for promoting the cooling of the second section, and the condenser fan motor 30 installed for improving the condensation capacity. To stop.

With the above configuration, the temperature of the evaporator during defrosting can be increased, and the defrosting efficiency can be improved.

Stopping all the fan motors is effective in reducing the power consumption during defrosting.

(Embodiment 5) FIG. 6 is a configuration diagram of a refrigeration cycle of a refrigerator according to this embodiment. The detailed description of the same components as those of the first to fourth embodiments is omitted, and the same reference numerals are given.

The refrigeration cycle of the refrigerator according to the present embodiment is similar to the first to fourth embodiments, except that the temperature detecting means 45 in the first section 22 for checking whether the inside of the refrigerator can be stored at an appropriate temperature.
It is composed of Table 5 shows the operation of each component during cooling and defrosting.

[0067]

[Table 5]

During the defrosting of the second evaporator 27, the first section 22 having a relatively high temperature is subjected to the second evaporator fan for promoting cooling of the second section by the section temperature detecting means 45. The operation of the motor 26 is determined by the control means.

With the above configuration, the temperature of the first section during defrosting can be stored at a predetermined appropriate temperature without overcooling or cooling, and good food freshness can be provided.

[0070]

As described above, according to the first aspect of the present invention,
According to the refrigerator described above, the first section and the second section can be cooled independently during the cooling operation, and the flow path control means after the second evaporator allows the evaporator 1 to move from the evaporator 1 to the compressor. It is possible to prevent a backflow to the flow of water. Further, the high-temperature gas discharged from the compressor at the time of defrost is passed through the flow path control means in the defrost circuit, the flow path control means after the second evaporator, and the flow path control means after the condenser. By flowing the high-temperature gas into the second evaporator, defrosting of the second evaporator can be performed without using a defrost heater. Further, the gas that has passed through the second evaporator flows from the second decompression means to the first decompression means and the first evaporator, and in the first section having a relatively high temperature, the defrosting operation of the second section is performed. Can be operated regardless of cooling.

According to the refrigerator of the second aspect of the present invention, the cooling operation is performed independently on the first section and the second section during the cooling operation, but the high temperature discharged from the compressor during the defrosting operation. By causing the gas to flow into the second evaporator by the flow path control means between the compressor and the condenser and the flow path control means after each evaporator, the same effect as in claim 1 and the refrigeration cycle The configuration is simplified, and the system can be configured at low cost.

Further, according to the refrigerator of the third aspect of the present invention, in the refrigerator of the first aspect, the flow path control means and the defrost circuit after the second evaporator for preventing backflow during the cooling operation. By integrating the flow control means into one, the number of parts and the storage space can be reduced, which leads to an improvement in the storage of the refrigerator.

Further, according to the refrigerator described in claim 4 of the present invention, in the refrigerator described in any one of claims 1 and 3, it is technically easy to use without using special flow control means capable of three directions. A highly efficient defrosting system can be provided with a simple flow path control means.

In addition, according to the refrigerator of the fifth aspect of the present invention, in the refrigerator of any one of the first to fourth aspects, a flow path control is provided between the compressor and the condenser separately from the defrost circuit. By providing means and providing a new defrost circuit, by configuring a circuit that does not cool the first compartment,
Excessive cooling of the relatively hot first compartment can be prevented.

In addition, according to the refrigerator of the sixth aspect of the present invention, in the refrigerator of any one of the first to fifth aspects, a four-way valve is used as a flow path control means between the compressor and the condenser. As a result, the cooling system can be simplified, the number of parts can be reduced, and the refrigerator can be stored more easily.

In addition, according to the refrigerator of the present invention, in the refrigerator of any one of claims 1 to 6, defrosting is performed by stopping a fan of an evaporator and a condenser during defrosting. It is possible to improve efficiency and reduce power consumption.

In addition, according to the refrigerator of the eighth aspect of the present invention, in the refrigerator of any one of the first to sixth aspects, the first evaporator is detected by the means for detecting the internal temperature in the first compartment. By defining the operation of the fan, the temperature of the first section can be maintained at an appropriate temperature.

[Brief description of the drawings]

FIG. 1 is a front view of a refrigerator according to the present invention.

FIG. 2 is a configuration diagram of a refrigeration cycle of the refrigerator according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a refrigeration cycle of a refrigerator according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a refrigeration cycle of a refrigerator according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a refrigeration cycle of a refrigerator according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a refrigeration cycle of a refrigerator according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view showing the structure around the evaporator of a conventional refrigerator.

FIG. 8 is a configuration diagram of a refrigeration cycle of a conventional refrigerator.

FIG. 9 is a time chart of defrosting control of an evaporator in a conventional refrigerator.

FIG. 10 is a configuration diagram of a refrigeration cycle according to an embodiment of a conventional refrigerator.

FIG. 11 is a time chart of a defrosting control of an evaporator according to an embodiment in a conventional refrigerator.

[Explanation of symbols]

Reference Signs List 21 refrigerator-freezer box 22 first section 23 second section 24 partition section 25 first evaporator 26 first evaporator fan motor 27 second evaporator 28 second evaporator fan motor 29 compressor 30 Condenser fan motor 31 Condenser 32 First decompression means 33 Second decompression means 34, 39 First flow path control means 35, 40 Second flow path control means 36 Cooling circuits 37, 41 Third flow path Control means 38 Defrosting circuit 42 Flow path control means for controlling the cooling circuit and the second defrosting circuit 43 First defrosting circuit 44 Second defrosting circuit 45 Temperature detecting means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Tanaka 4-5-2-5 Takaida Hondori, Higashi-Osaka City, Osaka Inside Matsushita Refrigerating Machinery Co., Ltd. (72) Koichi Nishimura 4-chome Takaida Hondori, Higashi-Osaka City, Osaka Prefecture No.2 No.5 Matsushita Refrigeration Co., Ltd. F term (reference) 3L045 AA01 AA02 AA03 BA01 CA02 DA02 EA01 HA02 HA07 JA03 JA14 JA15 LA09 LA14 NA03 NA05 PA01 PA04 PA05 3L046 AA01 AA02 AA03 BA01 CA03 JA03 JA09 JA14 LA02 LA05 MA01 MA04 MA05

Claims (8)

[Claims] 1. A refrigerator box comprising at least two compartments for controlling temperature in different temperature zones, comprising a first compartment having a relatively high temperature and a second compartment having a relatively low temperature. A first evaporator in the section and a second evaporator in the second section, a compressor, a condenser, the first through a first flow path control means and a first decompression means Are connected in sequence,
The second evaporator is connected in parallel with the first evaporator via a second decompression means, and a second flow path control means is provided on an outlet side of the second evaporator to provide a first section. And a refrigerator provided with a device for independently cooling the second compartment, wherein the high-temperature gas refrigerant discharged from the compressor flows into the second evaporator at the time of defrosting. The defrosting flow path and the third flow path control means provided in the first flow path control means for securing a flow path from the second evaporator to the first evaporator at the time of defrosting The cooling circuit of the first evaporator, the cooling circuit of the second evaporator, and a defrosting circuit including a flow path control means that can be switched in three directions and a control means for controlling them, thereby providing a second circuit. A refrigerator using a flammable refrigerant, which defrosts an evaporator. 2. A refrigerator box, comprising a compartment for controlling temperature in at least two different temperature zones, having a first compartment having a relatively high temperature and a second compartment having a relatively low temperature; A first evaporator in the section and a second evaporator in the second section, a compressor, a first flow path control means for controlling a refrigerant circuit and a defrost circuit, a condenser and a first The first evaporator is sequentially connected via a decompression means, and the second evaporator is connected in parallel with the first evaporator via a second decompression means,
A second flow path control means and a third flow path control means for controlling the respective flow paths on the outlet side of the first evaporator and the outlet side of the second evaporator are provided, and the first section and In a refrigerator provided with a device that independently cools the second section, at the time of defrosting, a high-temperature gas refrigerant discharged from the compressor is provided between the compressor and the condenser to flow into the second evaporator. Flammability characterized by comprising a first flow path control means and a control means for allowing a high-temperature gas refrigerant to flow from the defrost circuit to the second evaporator at the time of defrost by the defrost flow path. Refrigerator using refrigerant. 3. The apparatus according to claim 1, further comprising a flow path control means in which the second flow path control means and the third flow path control means are integrated into one. Refrigerator. 4. The first flow path control means, which can be switched in three directions, a cooling circuit for the first evaporator, a cooling circuit for the second evaporator, and a defrosting circuit, is replaced with three flow path control means. The refrigerator according to any one of claims 1 to 3, wherein the refrigerator is replaced. 5. A flow control means for securing a flow from the second evaporator to the condenser instead of securing a flow path from the second evaporator to the first evaporator during defrosting. A new second defrosting circuit and a flow path control means are provided between the machine and the condenser at a location different from the first defrosting circuit. Item. 6. A new flow path control means which integrates the flow dividing means of the first defrost circuit and the flow control means of the second defrost circuit between the compressor and the condenser into one. The refrigerator according to any one of claims 1 to 5, characterized in that: 7. The operation of an evaporator fan and a condenser fan for promoting cooling of the first section and the second section, wherein a control circuit for stopping the evaporator fan and the condensing fan during defrosting is provided. Item 7. The refrigerator according to any one of Items 1 to 6. 8. The operation of the evaporator fan and the condenser fan for accelerating the cooling of the first section and the second section, during the defrosting, the first evaporator fan is determined by the internal temperature detecting means. The refrigerator according to any one of claims 1 to 6, further comprising a control circuit that operates or stops in a mode and stops the second evaporator fan and the condensing fan.