CN111595087A - Refrigerator with a door - Google Patents

Abstract

A refrigeration cycle of a refrigerator is provided with a flow path switching valve (202) arranged at the downstream side of a 1 st condenser (107). A flow path switching valve (202) that branches into a cooling path that supplies a refrigerant that generates cold air to the evaporator (106) and a defrosting path; the defrosting path supplies the heated refrigerant to the evaporator (106) to perform defrosting. The refrigerant flowing through the defrosting path is heated by heat exchange with a path through which the refrigerant is supplied from the compressor (105) to the 1 st condenser (107). In the defrosting path, the warming-side evaporator (211) is provided on the windward side of the compressor (105), and the refrigerant discharged from the evaporator (106) is returned to the compressor (105) after being evaporated in the warming-side evaporator (211). Thus, a refrigerator is provided which can use the heat of a compressor (105) for defrosting and can suppress the occurrence of a sound that makes a user feel uncomfortable.

Description

Refrigerator with a door

Technical Field

The present invention relates to a refrigerator.

Background

Conventionally, refrigerators having a defrosting function for melting frost adhering to an evaporator are known, for example, from japanese patent laid-open nos. 58-024774 (hereinafter, described as "patent document 1") and 2018-004170 (hereinafter, described as "patent document 2"). The defrosting function is usually achieved by providing a defrosting heater below the evaporator and energizing the defrosting heater.

The refrigerator described in patent document 1 includes: an outlet of the compressor, a defrost pipe provided to the evaporator, and a path connecting the two. In addition, a structure is provided in which the high-temperature refrigerant discharged from the compressor is supplied to the defrosting pipe to defrost the same. That is, the refrigerator of patent document 1 uses the heat of the compressor for defrosting.

On the other hand, the refrigerator described in patent document 2 has a configuration in which the paths of the evaporator and the condenser outside the refrigerator can be switched by using a four-way valve. That is, the high-temperature refrigerant discharged from the compressor is supplied to the evaporator to defrost. The refrigerant is evaporated in the condenser outside the refrigerator and then returned to the compressor. Like the refrigerator of patent document 1, the refrigerator of patent document 2 uses the heat of the compressor for defrosting.

That is, the refrigerator of patent document 1 is configured to switch the flow path of the refrigerant to the defrosting pipe using a three-way valve at the time of defrosting. However, since the flow rate of the refrigerant flowing through the three-way valve is high, noise is likely to occur in the three-way valve. This may cause a user standing near the refrigerator to feel uncomfortable with the generated sound.

In the refrigerator disclosed in patent document 2, the amount of cooling generated in the condenser outside the refrigerator exceeds the amount of heat dissipated from the compressor during defrosting. Therefore, the air discharged from the mechanical portion of the refrigerator and having a temperature lower than the ambient temperature may cause condensation around the refrigerator.

Disclosure of Invention

The invention aims to provide a refrigerator which can use heat of a compressor for defrosting and can prevent generation of uncomfortable sound and condensation of dew for a user.

A refrigerator includes a refrigeration cycle including a compressor, a 1 st condenser, a 2 nd condenser, and an evaporator, and a refrigerant is supplied from the compressor to the 1 st condenser. The refrigeration cycle has a cooling path and a defrosting path branching at the downstream side of the 1 st condenser, the cooling path supplying refrigerant to the evaporator for generating cold air; the defrosting path heats the refrigerant, and supplies the heated refrigerant to the evaporator to defrost the same. In the cooling path, the refrigerant passes through the 2 nd condenser and is then supplied to the evaporator, and the refrigerant flowing through the defrosting path is heated by heat exchange with the path through which the refrigerant is supplied from the compressor to the 1 st condenser. In the defrosting path, the warming-side evaporator is provided on the windward side of the compressor, and the refrigerant discharged from the evaporator is evaporated in the warming-side evaporator and returned to the compressor.

In the refrigerator of the present invention, the temperature of the refrigerant evaporated in the heating side evaporator in the defrosting path is lower by 30 ℃ or more than the dew point temperature of the outside air around the refrigerator.

According to the above configuration, the heat of the compressor can be used for defrosting, and the occurrence of a sound that makes a user feel uncomfortable can be suppressed. In addition, it is possible to suppress a decrease in the temperature of air discharged from a machine chamber of the refrigerator housing the compressor, and to prevent condensation from occurring around the refrigerator.

Drawings

Fig. 1 is a vertical cross-sectional view of a refrigerator according to an embodiment of the present invention.

Fig. 2 is a vertical cross-section of the 1 st machine room of the refrigerator.

Fig. 3 is a schematic diagram showing a refrigeration cycle with the refrigerator.

Fig. 4 is a timing chart showing the operation of the refrigerator in the defrosting mode of the refrigerator.

Fig. 5 is a flowchart showing a process executed with the refrigerator.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. The following embodiments do not limit the inventions of the claims, and the combinations of features described in the embodiments are not necessarily all essential to the solutions of the inventions.

(embodiment mode)

Next, a refrigerator according to an embodiment of the present invention will be described with reference to fig. 1.

Fig. 1 is a vertical cross-sectional view of a refrigerator 100. Fig. 1 is a cross-sectional view of refrigerator 100 viewed from the side in the front-rear direction.

As shown in fig. 1, a refrigerator 100 of the present embodiment includes: a refrigerator compartment 101, a freezer compartment 102, a 1 st machine compartment 103, a 2 nd machine compartment 104, and the like. The freezing chamber 102 is provided at a lower portion of the refrigerating chamber 101. The 1 st machine room 103 is provided in the rear upper part of the refrigerator 100. The 2 nd machine room 104 is provided in the lower part of the refrigerator 100.

The refrigerator 100 includes components such as a compressor 105, an evaporator 106, and a 1 st condenser 107, which constitute a refrigeration cycle. The compressor 105 is housed in the 1 st machine chamber 103. The evaporator 106 is housed in the back (rear) of the freezing chamber 102. The 1 st condenser 107 is housed in the 2 nd machine chamber 104.

Hereinafter, the evaporator 106 side shown in fig. 1 will be referred to as the rear side, the opposite side thereof as the front side, the compressor 105 side as the upper side, and the 1 st condenser 107 side as the lower side. The 2 nd machine chamber 104 is divided into two areas by a partition wall 108. A fan 109 for air-cooling the 1 st condenser 107 is provided in the partition wall 108. The 1 st condenser 107 is housed in a region on the windward side (front side) of the fan 109 of the 2 nd machine room 104. The evaporation pan 110 is housed in a region on the leeward side (rear side) of the fan 109 in the 2 nd machine room 104.

The freezing compartment 102 includes a cooling fan 111, a freezing compartment damper 112, a temperature sensor 115, and the like, which are housed in the rear. The cooling fan 111 supplies cold air generated by the evaporator 106 to the refrigerating compartment 101, the freezing compartment 102, and the like. The freezing compartment damper 112 blocks cold air supplied to the freezing compartment 102 as necessary. The temperature sensor 115 detects the temperature of the evaporator 106.

Refrigerating compartment 101 includes duct 113, refrigerating compartment damper 114, and the like, which are housed in the rear. Duct 113 supplies the cold air generated by evaporator 106 to refrigerating compartment 101. The refrigerating compartment damper 114 blocks cold air supplied to the refrigerating compartment 101 as necessary.

As described above, the refrigerator 100 of the present embodiment is configured.

Next, the structure of the 1 st machine room 103 of the refrigerator 100 will be described mainly with reference to fig. 2.

Fig. 2 is a vertical cross-sectional view of the refrigerator 100. That is, fig. 2 is a cross-sectional view of refrigerator 100 viewed from the rear in the left-right direction. In addition, the following description will be made with the right side as the right side and the left side as the left side when the refrigerator 100 shown in fig. 2 is viewed from the front.

As shown in fig. 2, the 1 st machine chamber 103 includes a warming-side evaporator 211, a capacity-adjusting condenser 213, a warming-side evaporator fan 214, a compressor 105, and the like, which are housed therein. The warming-side evaporator 211 is housed on the most windward side (for example, left side) of the 1 st machine chamber 103. The capacity adjustment condenser 213, the warming-side evaporator fan 214, the compressor 105, and the like are arranged in this order from the windward side to the leeward side (for example, the right side) of the warming-side evaporator 211.

The inlet pipe 211a of the warming-side evaporator 211 is connected to the multistage expansion circuit 210. The outlet pipe 211b of the warming-side evaporator 211 is connected to the suction pipe 206 via a warming-side suction pipe 212. The heating-side intake pipe 212 is thermally coupled to a heat storage material 216 that is maintained at the atmospheric temperature in the 1 st machine chamber 103.

The warming-side evaporator 211 has a warming-side evaporation pan 215 disposed at a lower portion (lower portion). The warming-side evaporation pan 215 temporarily stores dew condensation water of the warming-side evaporator 211.

The heat storage material 216 is made of a paraffin-based latent heat storage material having a melting point of 10 to 40 ℃. The heat storage material 216 is maintained in a molten state at the atmospheric temperature in the 1 st machine chamber 103. Therefore, when the liquid refrigerant that has not been evaporated by the warming-side evaporator 211 enters the warming-side intake tube 212, the liquid refrigerant that has entered is evaporated by thermal coupling with the heat storage material 216. This prevents the liquid refrigerant from entering the suction pipe 206.

As described above, the 1 st machine chamber 103 of the refrigerator 100 is configured.

Further, the refrigerator 100 of the present embodiment accommodates components such as the defrosting heater 200 (see fig. 3), for example, in addition to the configuration described with reference to fig. 1 and 2. The components such as the defrosting heater 200 constitute the refrigeration cycle described with reference to fig. 3.

Next, a refrigeration cycle of the refrigerator 100 will be described with reference to fig. 3.

Fig. 3 is a schematic diagram showing a refrigeration cycle of refrigerator 100.

As shown in fig. 3, the refrigerant discharged from the compressor 105 of the 1 st machine room 103 exchanges heat with the outside air in the capacity adjustment condenser 213 and the 1 st condenser 107 of the 2 nd machine room 104. Thereby, the refrigerant leaves a portion of the gas to be condensed. The refrigerant having passed through the 1 st condenser 107 is subjected to moisture removal from air present in a small amount in the piping by the dryer 201 constituting the dryness adjuster, and flows into the flow path switching valve 202. At this time, the refrigerant flowing into the flow path switching valve 202 is in a state where the liquid-phase refrigerant and the gas-phase refrigerant are mixed.

Then, the flow path switching valve 202 branches the flow path of the refrigerant into a cooling path and a defrosting path.

The cooling path constitutes a path for supplying the refrigerant to the evaporator 106, and generates cold air. On the other hand, the defrosting path constitutes a path for heating the refrigerant and then supplying the heated refrigerant to the evaporator 106 to defrost.

First, the cooling path will be specifically described.

As shown in fig. 3, the cooling path is a path through which the refrigerant flows from the flow path switching valve 202 to the 2 nd condenser 203. The 2 nd condenser 203 is provided at a door (one or both of a door of the refrigerating compartment 101 and a door of the freezing compartment 102) of the refrigerator 100.

The refrigerant passing through the 2 nd condenser 203 radiates heat to the outside, thereby raising the temperature of the door of the installed refrigerator 100. This prevents condensation from occurring on the door of the refrigerator 100. At this time, the refrigerant is liquefied by heat dissipation.

The refrigerant liquefied by the 2 nd condenser 203 is decompressed by the 1 st throttle valve 204 and evaporated in the evaporator 106. At this time, the refrigerant evaporates in the evaporator 106, whereby the air near the evaporator 106 is cooled to generate cold air. The generated cold air is used for cooling the refrigerator compartment 101, the freezer compartment 102, and the like. Further, a two-way valve 205 is provided between the 2 nd condenser 203 and the 1 st throttle valve 204. The two-way valve 205 controls the flow of refrigerant to the evaporator 106 by switching.

The refrigerant having passed through the evaporator 106 is returned to the compressor 105 disposed in the 1 st machine chamber 103 via the suction pipe 206.

Next, the defrosting path will be specifically described.

As shown in fig. 3, the defrost path is a path through which the refrigerant flows from the flow path switching valve 202 to the 2 nd throttle 207.

The refrigerant flowing into the defrosting path is decompressed by the 2 nd throttle valve 207. The refrigerant decompressed by the 2 nd throttle 207 is heated and gasified in the 1 st heat exchange unit 208. That is, the refrigerant flowing through the 1 st heat exchanger 208 exchanges heat with the refrigerant flowing through the path 217 from the compressor 105 to the 1 st condenser 107. Thereby, the refrigerant flowing through the 1 st heat exchange portion 208 is heated and vaporized.

The vaporized refrigerant is then supplied to the evaporator 106, and heats the evaporator 106. Thereby, the evaporator 106 is defrosted.

The 1 st heat exchange portion 208 is formed by welding, for example, about 1 to 2m between a pipe through which the refrigerant discharged from the 2 nd throttle 207 flows and a part of a pipe through which the refrigerant is supplied from the compressor 105 to the 1 st condenser 107. The 1 st heat exchange unit 208 is formed on the outer wall surface of the casing of the refrigerator 100. This enables the sensible heat of the casing to be utilized for heating the refrigerant in the defrosting path.

When the refrigerant passes through the 1 st condenser 107, a part of the refrigerant is liquefied and reduced in volume. Therefore, the flow rate of the refrigerant flowing through the flow path switching valve 202 is reduced. That is, the flow path switching valve 202 allows the refrigerant having a slower flow rate in the 1 st condenser 107, rather than the gas-phase refrigerant having a faster flow rate discharged from the compressor 105. This can suppress the occurrence of a sound that the user feels uncomfortable in the flow path switching valve 202 due to the passage of the refrigerant having a high flow velocity as in the conventional refrigerator.

Next, the description will be continued on the defrosting path.

The refrigerant condensed while being heated in the evaporator 106 is decompressed again by the 3 rd throttle valve 209. The refrigerant after pressure reduction is supplied to the warming-side evaporator 211 via the multistage expansion circuit 210. The supplied refrigerant is evaporated by the evaporation mechanism of the warming side evaporator 211. The refrigerant having passed through the warming-side evaporator 211 is returned to the compressor 105 through the warming-side intake pipe 212 and the intake pipe 206.

Here, the evaporation temperature of the refrigerant in the warming side evaporator 211 is adjusted according to the decompression amount of the 3 rd throttle valve 209, the rotation speed of the compressor 105, and the like. The evaporation temperature of the refrigerant is usually maintained between-25 and-15 ℃ by regulation. At this time, the outside air flowing into the 1 st machine chamber 103 receives waste heat of the compressor 105 and the like located in the leeward while suppressing a temperature decrease when passing through the warming-side evaporator 211 by utilizing latent heat of condensation caused by condensation of water vapor contained in the outside air. This causes the outside air to rise to a temperature that is not significantly different from the temperature around the refrigerator 100, and to be discharged from the 1 st machine room 103.

In general, when the evaporator 106 is heated by the defrosting path, it is necessary to deprive the heating-side evaporator 211 of cooling heat corresponding to the amount of heating of the evaporator 106. On the other hand, the heating amount of the evaporator 106 is 2 to 3 times the waste heat of the compressor 105 and the like. Therefore, defrosting of the evaporator 106 can be performed efficiently. However, in the 1 st machine chamber 103, the cooling heat of the warming-side evaporator 211 is sometimes larger than the heat radiation amount of the compressor 105 and the like. In this case, since air having a temperature lower than the ambient temperature is discharged from the 1 st machine chamber 103, dew condensation may occur around the refrigerator.

Therefore, in the refrigerator 100 of the present embodiment, the evaporation temperature of the refrigerant in the heating side evaporator 211 is greatly reduced (preferably, 30 ℃ or more lower than the dew point) with respect to the dew point of the outside air. Accordingly, it is preferable to condense water vapor contained in the outside air and use the latent heat of condensation to suppress a decrease in the air temperature.

In the refrigerator 100 of the present embodiment, the 3 rd throttle valve 209 is formed by a capillary tube having an inner diameter of 0.5 to 1mm, and the multistage expansion circuit 210 is formed by a small-diameter tube having an inner diameter of 1.5 to 3 mm. That is, the inner diameter of the 3 rd throttle valve 209 and the inner diameter of the multistage expansion circuit 210 are gradually increased toward the refrigerant pipe having an inner diameter of 6 to 9mm of the heating side evaporator 211. This suppresses the occurrence of noise due to rapid expansion or speed change of the refrigerant. Further, the increase in the outer surface area of the tube can be suppressed by gradually thickening the inner diameter. This reduces the amount of frost on the surface of the pipe, thereby reducing the outflow of dew condensation water.

That is, the refrigerator 100 of the present embodiment preferably has the following configuration: most of the 3 rd throttle valve 209 is embedded in a heat insulating material (not shown) constituting a casing of the refrigerator 100, and only a connection portion between a part of the multistage expansion circuit 210 and the heating side evaporator 211 is exposed in the 1 st machine chamber 103.

In the present embodiment, the heat storage material 216 is described as an example of a paraffin-based latent heat storage material having a melting point of 10 to 40 ℃. As the heat storage material 216, for example, a heat conductive member such as a general-purpose resin or a rubber material may be used. Further, the heat storage material 216 may be thermally coupled to a component (not shown) constituting the wall surface of the 1 st machine chamber 103, a component (not shown) constituting the outer contour of the compressor 105, or the refrigerator 100. This improves the performance of evaporating the liquid refrigerant that enters, and prevents the liquid refrigerant from entering the suction pipe 206. In addition, since the amount of the heat storage material 216 can be reduced while maintaining the performance of evaporating the liquid refrigerant, the cost can be reduced.

In the present embodiment, the compressor 105 and the components (not shown) that form the outer contour of the 1 st machine chamber 103 or the refrigerator 100 are made of a sensible heat storage material. They are heavier than the warm side suction tube 212. Therefore, the 1 st machine chamber 103, the constituent members, and the compressor 105 have sufficient heat capacity. This makes it possible to easily evaporate the liquid refrigerant that flows back.

As described above, the refrigeration cycle of the refrigerator 100 is configured and operated.

Next, the operation of refrigerator 100 in the defrosting mode in which evaporator 106 is defrosted will be described with reference to fig. 4.

Fig. 4 is a timing chart showing the operation of refrigerator 100 in the defrosting mode. In fig. 4, time is shown from left to right.

As shown in fig. 4, "ON" of the compressor 105 indicates an operating state of the compressor 105, and "OFF" of the compressor 105 indicates a stopped state of the compressor 105. The "ON" of the warming-side evaporator fan 214 indicates the operating state of the warming-side evaporator fan 214, and the "OFF" of the warming-side evaporator fan 214 indicates the stopped state of the warming-side evaporator fan 214.

The "cooling" of the flow path switching valve 202 indicates a state in which the flow path from the flow path switching valve 202 to the cooling path is opened and the flow path from the flow path switching valve 202 to the defrosting path is closed. The "defrosting" of the flow path switching valve 202 indicates a state in which the flow path from the flow path switching valve 202 to the defrosting path is opened and the flow path from the flow path switching valve 202 to the cooling path is closed. Further, "fully closed" of the flow path switching valve 202 indicates a state in which both the flow path from the flow path switching valve 202 to the cooling path and the flow path from the flow path switching valve 202 to the defrosting path are closed.

The "on" of the two-way valve 205 indicates a state in which the two-way valve 205 is opened, and the "off" of the two-way valve 205 indicates a state in which the two-way valve 205 is turned off. The "ON" of the cooling fan 111 indicates an operation state of the cooling fan 111, and the "OFF" of the cooling fan 111 indicates a stop state of the cooling fan 111.

The "open" of the freezing compartment damper 112 indicates a state in which the freezing compartment damper 112 is opened, and the "closed" of the freezing compartment damper 112 indicates a state in which the freezing compartment damper 112 is closed. The "open" of the refrigerating compartment damper 114 indicates a state in which the refrigerating compartment damper 114 is opened, and the "closed" of the refrigerating compartment damper 114 indicates a state in which the refrigerating compartment damper 114 is closed.

Further, "ON" of the defrosting heater 200 indicates a state in which the defrosting heater 200 is energized to defrost the defrosting heater 200. On the other hand, "OFF" of the defrosting heater 200 indicates a state in which the energization to the defrosting heater 200 is stopped and defrosting of the defrosting heater 200 is not performed.

The time T1 shown in fig. 4 is a time when the accumulation of the operating time of the compressor 105 reaches a predetermined time.

First, at time T1, refrigerator 100 shifts from the normal cooling mode to the defrosting mode. At this time, it is assumed that the temperature of the freezing chamber 102 starts to rise by defrosting. Therefore, refrigerator 100 turns freezing room damper 112 ON, and temporarily opens it. Thereby, the temperature of the freezing chamber 102 is lowered before defrosting is started.

Next, at time T2, the state of the flow path switching valve 202 is switched from "cooling" to "defrosting". Then, the flow path of the refrigerant is switched from the cooling path to the defrosting path. Thereby, the refrigerant heated by the 1 st heat exchange portion 208 is supplied to the evaporator 106, and defrosting of the evaporator 106 is started. As shown in fig. 3, defrosting in the defrosting path is performed on the upper side of the evaporator 106. On the other hand, defrosting of the lower side of the evaporator 106 is performed by a defrosting heater 200 described later.

At time T2, the state of the two-way valve 205 is switched from "on" to "off". By closing the two-way valve 205, the inlet and outlet of the 2 nd condenser 203 are closed. Thereby, the refrigerant is stored in the 2 nd condenser 203.

At this time, the amount of refrigerant in the defrosting operation is appropriately adjusted, and the dryness of the 1 st condenser 107 is adjusted to 0 to 50% by the dryer 201 constituting the dryness adjuster. As a result, the flow velocity of the refrigerant flowing through the flow path switching valve 202 can be suppressed, and the occurrence of noise due to the refrigerant flow can be prevented.

Generally, when the dryness of the 1 st condenser 107 exceeds 50%, the flow rate of the refrigerant increases. Therefore, the sound of the refrigerant flow flowing through the flow path switching valve 202 becomes loud. Therefore, the dryness of the 1 st condenser 107 is adjusted to 50% or less, and occurrence of uncomfortable sound to the user is prevented.

On the other hand, when the dryness of the 1 st condenser 107 is less than 0%, i.e., the refrigerant is in a supercooled state, the refrigerant loses enthalpy. Therefore, the refrigerant is not sufficiently vaporized in the 1 st heat exchange portion 208. This reduces the amount of heat required to defrost the evaporator 106 of the 1 st heat exchanger 208. Therefore, the dryness of the 1 st condenser 107 is more preferably adjusted to 0 to 50%.

In the above embodiment, the flow path switching valve 202 and the two-way valve 205 are simultaneously switched at time T2, but the present invention is not limited to this. For example, after the flow path switching valve 202 is switched from "cooling" to "defrosting", the two-way valve 205 may be switched from "open" to "closed" after a predetermined time has elapsed. This can reduce the amount of refrigerant stored in the 2 nd condenser 203. Further, after the two-way valve 205 is switched from "on" to "off", the flow path switching valve 202 may be switched from "cooling" to "defrosting" after a predetermined time has elapsed. This can increase the amount of refrigerant stored in the 2 nd condenser 203. That is, by switching the flow path switching valve 202 and the two-way valve 205 in accordance with various conditions such as the outside air temperature, the storage amount of the refrigerant in the 2 nd condenser 203 can be adjusted to the optimum amount of refrigerant.

Further, at time T2, the state of the freezing compartment damper 112 is switched from "open" to "closed". Then, the state of the refrigerating compartment damper 114 is switched from "closed" to "open". This heats evaporator 106 from the air side while circulating the air in refrigerating room 101. That is, the switching operation is performed to evaporate the refrigerant remaining in the pipe of the evaporator 106 and return the refrigerant to the compressor 105.

Next, at time T3, the state of cooling fan 111 is switched from "ON" to "OFF". Then, the state of the refrigerating compartment damper 114 is switched from "open" to "closed". The switching operation between the refrigerating compartment damper 114 and the cooling fan 111 is performed to avoid difficulty in heat exchange due to the fact that the temperature of the evaporator 106 approaches the air temperature of the refrigerating compartment 101 as the refrigerant remaining in the piping of the evaporator 106 evaporates.

Next, at time T4, the state of the defrosting heater 200 is switched from "OFF" to "ON". Thereby, the energization of the defrosting heater 200 is started, and defrosting of the lower side of the evaporator 106 is started.

Next, at time T5, the state of the compressor 105 is switched from "ON" to "OFF". The time T5 is a time when the temperature detected by the temperature sensor 115 reaches a predetermined temperature. That is, the time when refrigerator 100 determines that defrosting of evaporator 106 is completed.

This stops the operation of the defrosting path.

Further, the OFF state of the compressor 105 is maintained for a predetermined time until the pressure in the defrosting path is substantially equalized (including equalized). Specifically, a predetermined time from the time T5 to, for example, a time T8 is maintained. At this time, the defrosting heater 200 that was turned "ON" at time T4 is maintained in the "ON" state for a predetermined time period up to time T7. The predetermined time period until the time T7 is a time period until the frost on the lower side of the evaporator 106 is melted.

Next, at time T6, the state of the warming-side evaporator fan 214 is switched from "ON" to "OFF", and the state of the flow path switching valve 202 is switched from "defrost" to "cool". Further, the two-way valve 205 is switched from "closed" to "open", and the freezer door is switched from "closed" to "open".

The reason why the "OFF" state of the compressor 105 is maintained for the predetermined time from the time T5 to the time T8 is to prevent the generation of uncomfortable noise in addition to the substantial pressure equalization (including the pressure equalization) in the defrosting path. That is, when the flow path switching valve 202 or the two-way valve 205 is switched, the refrigerant may suddenly flow in the flow path switching valve 202 or the two-way valve 205, and uncomfortable noise may be generated. Therefore, the "OFF" state of the compressor 105 is maintained for a predetermined time, and the rapid flow of the refrigerant is suppressed, thereby preventing the occurrence of noise.

In addition, the warming-side evaporator fan 214 is maintained in the "ON" state from the time T5 to a time T6. This enables the temperature of the warming side evaporator 211 connected to the evaporator 106 via the suction pipe 206 to be rapidly increased. As a result, the refrigerant remaining in the heating side evaporator 211 can be evaporated, and the start of the next cooling operation can be accelerated.

Next, at time T7, the state of the defrosting heater 200 is switched from "ON" to "OFF". Thereafter, the defrosting heater 200 is kept in the OFF state until, for example, time T8 when the residual heat of the defrosting heater 200 is cooled, and is on standby.

Next, at time T8, the state of the compressor 105 is switched from "OFF" to "ON" and the cooling path starts to operate.

Then, the system stands by for a predetermined time until a time T9 when the temperature of the evaporator 106 sufficiently decreases.

Next, after waiting for a predetermined time, at time T9, the state of the heating side evaporator fan 214 is switched from "OFF" to "ON", and the state of the cooling fan 111 is switched from "OFF" to "ON". Thereby, refrigerator 100 moves from the defrost mode to the cool mode.

As described above, refrigerator 100 operates in the defrosting mode in which evaporator 106 is defrosted.

Next, the Processing operation executed by the cpu (central Processing unit) of the refrigerator 100 in the defrosting mode will be described with reference to fig. 5.

Fig. 5 is a flowchart showing processing operations performed by refrigerator 100 in the defrosting mode. The steps shown in the flowchart of fig. 5 are processed by the CPU of the refrigerator 100 executing a control program stored in a memory such as a ROM of the refrigerator 100. In fig. 1, although not shown, a CPU, a ROM (read Only memory), or the like is housed in the top surface of the refrigerator 100, for example, in a control board constituted by a CPU or a ROM.

As shown in fig. 5, the CPU first determines whether or not defrosting is performed (step S401). In the present embodiment, the CPU determines that it is time to perform defrosting when the accumulation of the operating time of the compressor 105 reaches a predetermined time (for example, 13 hours). The operation of step S401 corresponds to time T2 in fig. 4.

Next, the CPU switches the flow path of the refrigerant to the defrosting path (step S402). Specifically, the CPU controls the flow path switching valve 202 to switch the flow path of the refrigerant from the cooling path to the defrosting path. Thereby, the refrigerant heated by the 1 st heat exchange portion 208 is supplied to the evaporator 106, and defrosting of the evaporator 106 is performed. Further, as described above, defrosting via the defrosting path is performed centering on the upper side of the evaporator 106. The operation of step S402 corresponds to times T2 to T4 in fig. 4.

Next, the CPU starts the energization operation of the defrosting heater 200 (step S403). Thereby, defrosting of the evaporator 106 is performed. In addition, the defrosting of the defrosting heater 200 is performed centering on the lower side of the evaporator 106. The operation of step S403 corresponds to time T4 to time T7 in fig. 4.

Next, the CPU determines whether defrosting has been completed (step S404). In the present embodiment, the CPU determines that defrosting is completed when the temperature detected by the temperature sensor 115 reaches a predetermined temperature (for example, 10 ℃). The operation of step S404 corresponds to time T7 in fig. 4. At this time, if the temperature is lower than the predetermined temperature, the CPU determines that defrosting is not completed (No in step S404). Then, the CPU continues to operate until the temperature detected by the temperature sensor 115 reaches a predetermined temperature, and determines that defrosting of the defrosting heater 200 is completed.

On the other hand, if the CPU determines that the detected temperature has reached the predetermined temperature (Yes in step S404), the CPU returns the flow path of the refrigerant to the cooling path to stop the operation of the defrosting heater 200 (step S405). Specifically, the CPU controls the flow path switching valve 202 to switch the flow path of the refrigerant from the defrosting path to the cooling path. Then, the CPU stops the energization operation to the defrosting heater 200. The operation of step S405 corresponds to time T5 to time T7 in fig. 4.

As is clear from the above, the processing operation in the defrosting mode executed by the CPU of the refrigerator 100 is completed.

Next, after the defrosting mode is finished, the CPU waits for a predetermined time and then drives the compressor 105. After that, the CPU drives the warming-side evaporator fan 214 and the cooling fan 111 to start blowing. Thereby, the cooling operation of the refrigerator 100 is started (step S406). The operation of step S406 corresponds to time T7 to time T9 in fig. 4.

In the present embodiment, the description has been made by taking an example in which each step shown in the flowchart of fig. 5 is executed by one CPU, but the present invention is not limited to this. For example, a configuration having a plurality of CPUs may be adopted. In this case, it is preferable to adopt a configuration in which each step is executed by cooperation of a plurality of CPUs.

According to the refrigerator of the present embodiment, the refrigerant flowing through the defrosting path is heated by the high-temperature refrigerant discharged from the compressor 105 in the 1 st heat exchange portion 208. Therefore, the heat of the compressor 105 can be used for defrosting the evaporator 106.

The refrigerant discharged from the compressor 105 has an intact flow velocity and is configured not to flow through the flow path switching valve 202. Therefore, it is possible to suppress the occurrence of a sound in the flow path switching valve 202, which is unpleasant for the user due to the flow velocity of the refrigerant and the like.

Claims (8)

1. A refrigerator having a refrigeration cycle including a compressor, a 1 st condenser, a 2 nd condenser, and an evaporator, a refrigerant being supplied from the compressor to the 1 st condenser, the refrigerator characterized in that:

the refrigeration cycle includes a cooling path branched at a downstream side of the 1 st condenser, the cooling path supplying a refrigerant to the evaporator to generate cold air, and a defrosting path heating the refrigerant and supplying the heated refrigerant to the evaporator to defrost the evaporator,

in the cooling path, the refrigerant is supplied to the evaporator after passing through the 2 nd condenser,

the refrigerant flowing through the defrosting path is heated by heat exchange with a path through which the refrigerant is supplied from the compressor to the 1 st condenser,

in the defrosting path, a warming-side evaporator is provided on an upwind side of the compressor, and the refrigerant discharged from the evaporator is evaporated in the warming-side evaporator and then returned to the compressor.

2. A refrigerator as claimed in claim 1, wherein:

in the defrosting path, the temperature of the refrigerant evaporated in the warming-side evaporator is lower by 30 ℃ or more than the dew point temperature of the outside air around the refrigerator.

3. A refrigerator as claimed in claim 1 or 2, characterized in that:

the refrigeration cycle has, in the defrost path:

a warming-side suction pipe connecting the warming-side evaporator and the compressor; and

a heat storage material thermally bonded to the heating-side intake pipe,

the refrigerant discharged from the warming-side evaporator is heated by heat exchange with the heat storage material.

4. The refrigerator according to any one of claims 1 to 3, wherein:

the refrigeration cycle has a multistage expansion circuit connected to an inlet side of the warming-side evaporator in the defrosting path.

5. The refrigerator according to any one of claims 1 to 4, wherein:

the refrigeration cycle includes a dryness adjuster in the defrosting path for adjusting the dryness of the refrigerant downstream of the 1 st condenser to an appropriate range.

6. The refrigerator according to any one of claims 1 to 5, wherein:

in a case where a defrosting mode is performed, the refrigerator switches the flow path through which the refrigerant flows from the cooling path to the defrosting path.

7. The refrigerator of claim 6, wherein:

when the defrosting mode is completed, the refrigerator returns the flow path through which the refrigerant flows from the defrosting path to the cooling path.

8. The refrigerator of claim 6, wherein:

after the flow path through which the refrigerant flows is switched to the defrosting path, the refrigerator starts to operate a defrosting heater.

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