JP4013875B2 - Freezer refrigerator - Google Patents

Description

  The present invention relates to a refrigerator-freezer having a refrigeration cycle that sends refrigerant to two coolers using a two-stage compressor.

  A conventional refrigerator has a compressor, condenser, capilla tube, refrigeration evaporator, and refrigeration evaporator connected in series, and a refrigerant flow rate variable device is provided between the refrigeration evaporator and the refrigeration evaporator for refrigeration. The refrigeration evaporator is variably controlled in the evaporating temperature, and even if it is desired to cool only the freezer compartment by applying a single-stage compression cycle, the refrigerant is allowed to pass through the cooler installed in the refrigerator compartment. (For example, refer to Patent Document 1).

  The conventional refrigerator forms a closed loop with the compressor, the condenser, the flow path control means, the first pressure reducing means, and the first evaporator, and is parallel to the first pressure reducing means and the first evaporator. The second decompression means and the second evaporator are connected so that the two evaporators are switched alternately by arranging the flow path control means on the inlet side of the first and second decompression means. Thus, the freezer compartment and the refrigerator compartment are controlled to be alternately cooled (see, for example, Patent Document 2).

  In the conventional refrigerator, a freezer cooler, a refrigerator for cooling, a compressor having two compression chambers, a condenser, and a refrigerant pipe from the freezer chamber and the cooler cooler communicate with the two compression chambers. Some of them are connected to each of the suction passages, and have means for switching between an operation of operating the freezer cooler and the refrigerator cooler at the same time and an operation of operating the freezer cooler alone. And in such a refrigerator-freezer using a two-stage compressor, the refrigerator-freezer is controlled using the refrigerator compartment temperature detection means and the refrigerator compartment temperature detection means (for example, refer patent document 3).

JP 2001-133112 A (page 3-5, FIG. 1-2) JP 2003-207247 A (page 4-5, FIG. 1-2) Japanese Patent Laid-Open No. 2001-263901 (page 3-5, Fig. 1-3)

  As described above, when a two-stage compressor is mounted on a conventional household refrigerator and includes a refrigerator for a refrigeration temperature zone and a cooler for a refrigeration temperature zone, there is a problem of operation control in accordance with the cooling load of the refrigerator. For example, when the cooling load is generated only in the freezer compartment, the cooler installed in the refrigerator compartment does not perform the cooling operation, and there is a problem such as a control method therefor.

  Moreover, in the conventional refrigerator, although control using the refrigerator compartment temperature detection means and freezer compartment temperature detection means is implemented, since the detection temperature is not judged simultaneously on the control flow, a delay occurs in the control, etc. There is a problem.

  The present invention has been made to solve these problems, and aims to increase the refrigeration cycle efficiency of a refrigerator and to obtain a refrigerator with low power consumption. Furthermore, it aims at obtaining the refrigerator which reduced the refrigerant | coolant amount and improved safety | security significantly in the refrigerator etc. which used the combustible refrigerant | coolant etc. which have very little influence on global warming.

The refrigerator-freezer according to the present invention is provided with an electric motor and a compression element driven by the electric motor in a sealed container, and the compression element includes a low-stage compression section and a high-stage compression section. A low-stage compression section and a high-stage compression section of the compressor, a condenser, a flow path switching means, a first expansion means connected to the flow path switching means and flowing a refrigerant to a refrigerator for a refrigerator compartment, and the flow path A refrigeration cycle comprising a second expansion means for a low cooling load and a third expansion means for a high cooling load, which are connected to the switching means and provided in parallel so as to flow a refrigerant to the cooler for the freezer compartment; , Refrigerator temperature detection means, freezer temperature detection means, ambient temperature detection means, refrigerator internal refrigerator fan and freezer compartment fan, the refrigerator temperature detection means and freezer temperature detection means respectively Temperature higher than the set temperature When the flow path switching unit communicates both the first expansion unit and the second expansion unit, the temperature detected by the refrigerator temperature detection unit is lower than a set temperature, and When the temperature detected by the freezer temperature detection means is higher than the set temperature, only the third expansion means communicates with the flow path switching means , and the temperature detected by the refrigerator temperature detection means is higher than the set temperature. When the temperature detected by the freezer temperature detection means is lower than a set temperature and it is determined that only the refrigerator compartment needs to be cooled, the flow path switching means causes the first expansion means and the second expansion to be Both of the means are communicated to control the refrigerator compartment and the freezer compartment at the same time .

  The compressor is controlled so as to determine the rotational speed of the compressor based on the signal detected by the ambient temperature detecting means.

When the ambient temperature detected by the ambient temperature detecting means is lower than a preset temperature and the cooling load is small, the second expansion means is used as the expansion means for cooling the freezer in the flow path switching means. When the ambient temperature is higher than the set temperature and the cooling load is large, the third expansion means is selected by the flow path switching means.

According to the refrigerator-freezer according to the present invention, an electric motor and a compression element driven by the electric motor are provided in the sealed container, and the compression element is composed of a low-stage compression section and a high-stage compression section. A first stage expansion means that is connected to the flow path switching means and flows the refrigerant to the refrigerator for the refrigerating chamber, the compressor and the lower stage compression section and the higher stage compression section of the compressor, the condenser, the flow path switching means, A refrigeration system comprising a second expansion means for a low cooling load and a third expansion means for a high cooling load, which are connected to the flow path switching means and provided in parallel so as to flow the refrigerant to the freezer cooler. A refrigerator, a refrigerator internal temperature detection means, a freezer internal temperature detection means, an ambient temperature detection means, a refrigerator compartment internal fan and a freezer compartment internal fan, the refrigerator internal temperature detection means and the freezer internal temperature detection means From preset temperature set in advance When the temperature is detected, the flow switching means communicates both the first expansion means and the second expansion means, and the temperature detected by the refrigerator temperature detection means is smaller than a set temperature, When the temperature detected by the freezer temperature detecting means is higher than the set temperature, only the third expansion means is communicated by the flow path switching means , and the temperature detected by the refrigerator temperature detecting means is the set temperature. If the temperature detected by the freezer temperature detection means is lower than the set temperature and it is determined that only the refrigerator compartment needs to be cooled, the flow path switching means and the first expansion means and the second communicating both inflation means, so controlled to cool the refrigerator compartment and the freezer compartment at the same time, it can be adjusted capacity in accordance with the cooling load, high cooling reliability refrigerator It is possible to provide.

Embodiment 1 FIG.
FIG. 1 is a refrigerant circuit diagram of a refrigerator-freezer showing an example of the embodiment of the present invention, and FIG. 2 is a side sectional view of the refrigerator-freezer. A hydrocarbon refrigerant R600a (isobutane) that has a very small influence on global warming is used as a refrigerant in the refrigeration cycle of the refrigerator-freezer.

  In the figure, 1 is a compressor, 2 is a high-stage compression unit, 3 is a low-stage compression unit, 4 is a condenser connected to the discharge side of the high-stage compression unit 3 of the compressor 1 and into which discharge refrigerant flows, 5 Is an electric flow path switching valve that is a flow path switching means piped from the outlet of the condenser 4 and can communicate or close the flow path by an electrical signal from the outside. Reference numeral 6 denotes a refrigeration capillary connected to the outflow side of the electric flow path switching valve 5 and serves as a first expansion means for cooling the refrigeration chamber. Reference numeral 7 denotes a high stage of the compressor 1 from the refrigeration capillary 6 and the refrigeration cooler 8. A refrigeration heat recovery heat exchanger 15, which is in contact with the high-stage suction pipe 9 that guides the refrigerant to the side compression unit 2 and fixed by soldering or the like, 15 is an accumulator provided in the middle of the high-stage suction pipe 9. 10 is a low cooling load capillary for freezing, which is a second expansion means for the freezer connected to the outflow side of the electric flow path switching valve 5, and 11 is connected to the outflow side of the electric flow path switching valve 5. High cooling load for refrigeration, which is the third expansion means for the freezing chamber, which is arranged in parallel with the capillary 10 for low cooling load, which is the second expansion means, and is connected to the refrigeration cooler 13. Capillary tube 12 is a heat-recovery heat exchange for refrigeration in which capillary tube 10 for low cooling load and low-temperature capillary tube 11 for high cooling load are brought into contact with a suction pipe connected from the outlet of refrigeration cooler 13 and fixed by soldering or the like. , 14 is a low-stage suction pipe connected from the outlet of the refrigeration cooler 13 and circulated to the low-stage compression section 3 of the compressor 1, and these are sequentially connected by pipes to form a refrigeration cycle.

  FIG. 3 is a schematic view of the electric switching valve, and FIG. 4 is an enlarged cross-sectional view taken along a section XX in FIG. In the figure, 17 is a switching valve body comprising a valve seat 19 and a valve body 20 to which an inflow / outflow pipe is connected, and 18 is a drive motor for rotating the valve body 20 such as a stepping motor. The valve seat 19 has three outflow portions: an outflow portion to the refrigeration capillary 6 (A), an outflow portion to the low cooling load capillary 10 (A), and an outflow portion (C) to the high cooling load capillary 11. On the other hand, the valve body 20 is provided with two communication holes. This electric flow path switching valve 5 connects the piping from the outlet of the condenser 4 to the inlet side of the refrigeration capillary 6 and the low cooling load capillary 10 and the high cooling load capillary 11, with the valve body rotating center inside. When the refrigeration capillary 6 and the refrigeration capillary 10 for refrigeration are simultaneously communicated from the condenser side by the operation of the valve body supported by the shaft (d), the refrigeration capillary 6 and the refrigeration from the condenser side. When the high cooling load capillary 11 is connected (e), when only the high cooling load capillary 11 is connected from the condenser side (f), and all the refrigeration capillaries and freezing capillaries are connected from the condenser side It is possible to close (c). In addition, the low-cooling-load capillary 10 that is the second expansion means for the freezer and the high-cooling-load capillary 11 that is the third expansion means for the freezer are used in accordance with the cooling load. Switching is performed with the switching valve 5.

  1 and 2, reference numeral 21 denotes a refrigeration thermistor which is a refrigeration chamber temperature detection means disposed in the refrigeration chamber 26, 22 is a refrigeration thermistor which is a refrigeration chamber temperature detection means disposed in the freezer compartment 27, 29 Is an ambient temperature detecting means which is disposed in the outer part of the refrigerator and detects the ambient temperature of the refrigerator-freezer, and 23 is an actuator such as a compressor or a blower of the refrigerator-freezer which receives the temperature information detected by each of these thermistors. A controller 24 for controlling the operation of the refrigerator, 24 for the refrigerator compartment for sending air to the refrigerator 8 for refrigeration and circulating the cold air into the refrigerator compartment, 25 for the refrigerator compartment for circulating air to the refrigerator compartment 13 by sending air to the refrigerator 13 for freezer A blower 28 is a vegetable room that communicates with the refrigerator compartment 26 via an air passage.

  Next, refrigerator operation control is demonstrated using FIG. FIG. 5 is a flowchart of operation control of the refrigerator-freezer. In the figure, tCOMP is the compressor operation integrated operation time, tsetCOMP is the compressor set operation integration time, and the compressor set operation integration time is the defrost operation. It is a value that determines the timing to perform. The start of the operation control of the refrigerator-freezer is started after the refrigerator-freezer is turned on (S10). First, the ambient temperature is detected by the detection means 29. Depending on the detected value, the control constant of the refrigerator, for example, the upper limit value and the lower limit value of the freezer compartment set temperature, the upper limit value and the lower limit value of the refrigerator compartment set temperature, the rotation speed of the compressor 1, the refrigerator 24 for the refrigerator compartment and the freezer compartment The rotation speed of the blower 25, the initial value of the compressor integration time for performing the defrosting operation, and the like are determined (S11).

  Thereafter, the accumulated operation time tCOMP of the compressor 1 is compared with the set accumulated operation time tsetCOMP (S12). When the actual accumulated operation time tCOMP is smaller than the set value tsetCOMP of the accumulated operation time of the compressor determined by the ambient temperature (determination) A) performs a cooling operation (S13), and when it is large (determination B or determination C), performs a defrosting operation (S15 or S17). During the cooling operation, the accumulated operation time of the compressor is always monitored, and the defrosting operation is performed immediately when the compressor integration time becomes larger than the set value tsetCOMP. Further, when the accumulated operation time tCOMP of the compressor becomes larger than the set value, the defrosting operation is executed, and when the defrosting operation is finished, the cooling operation is controlled to be continued.

  Next, the cooling operation described above will be described with reference to FIG. FIG. 6 is a flowchart for controlling the cooling operation of the refrigerator-freezer. Rth shown in the figure is a value detected by the refrigerated thermistor 21 serving as the refrigerator temperature detecting means, and Fth is a value detected by the refrigerator thermistor serving as the refrigerator temperature detecting means. , TsetR is a preset temperature of the refrigerator compartment stored in the controller 23 in advance, and TsetF is a preset temperature of the freezer compartment stored in the controller 23 in advance.

  First, the case where the value detected by the ambient temperature detection means 29 is small and the cooling load is small will be described. The number of revolutions of the compressor 1 and the number of revolutions of the refrigerator compartment fan 24 and the freezer compartment fan 25 are set to be small and the air volume is reduced. Furthermore, the electric flow path switching valve 5 is controlled so as to select the refrigeration low cooling load capillary 10 which is the second expansion means provided with the freezer compartment cooling capillary tube for low cooling load.

  When the freezing thermistor 22 and the refrigerating thermistor 21 serving as temperature detecting means for the freezer compartment and the refrigerating compartment detect temperatures higher than the preset temperatures TsetF and TsetR, respectively (S102), the electric flow path switching valve 5 Is connected to the refrigeration capillary 6 and the low cooling load capillary 10 used when the cooling load selected by the ambient temperature is small, and the compressor 1, the refrigerating room blower 22 and the freezing room blower 24 are connected. (S104) and the operation of cooling the freezer compartment 27 and the refrigerator compartment 26 at the same time is performed.

  When the value Rth detected by the refrigerator temperature detecting means 21 is smaller than the preset value TsetR and the value Fth detected by the freezer compartment temperature detecting means 22 is larger than the preset value TsetF (S102), the refrigerator is stored. The room blower 24 is stopped, the electric flow path switching valve 5 is brought into a state of communicating only with the high cooling load capillary 11 for freezing, and only the freezing room 27 is cooled so that the refrigerant flows only into the freezing room cooler 13. (S103).

  When the value Rth detected by the refrigerator temperature detecting means 21 is larger than the preset value TsetR and the value Fth detected by the freezer compartment temperature detecting means 22 is smaller than the preset value TsetF, the previous refrigerator compartment The simultaneous cooling operation of 26 and the freezer compartment 27 is continued.

  Further, when the value Rth detected by the refrigerating room temperature detecting means 21 is smaller than the preset value TsetR and the value Fth detected by the freezer compartment temperature detecting means 22 is smaller than the preset value TsetF (S107). ) Stops the freezer compartment fan 25 and the refrigerator compartment fan 24, and also stops the compressor 1 (S108). As a result, the cooling operation ends (S14).

  Next, the operation of the refrigeration cycle when the freezer compartment 27 and the refrigerator compartment 26 are simultaneously cooled will be described with reference to FIGS. FIG. 7 is a Ph diagram in the case where the freezer compartment 27 and the refrigerator compartment 26 are simultaneously cooled. The horizontal axis represents enthalpy [kJ / kg] and the vertical axis represents pressure [kPa]. The same place as the position shown on the refrigerant circuit of 1 is shown. The high-temperature and high-pressure vapor refrigerant (A) discharged from the high-stage compression unit 2 of the compressor 1 releases heat to the outside of the refrigerator by the condenser 4 to be condensed and liquefied (B). Thereafter, the electric flow is switched by the electric flow path switching valve 5, and one flows into the refrigerating room capillary 6. In the refrigeration capillary 6, the high-temperature and high-pressure refrigerant is decompressed and expanded into a medium-temperature and medium-pressure gas-liquid two-phase refrigerant (C). The refrigerating cooler 7 takes heat from the air in the refrigerating chamber to evaporate and cools the refrigerating chamber (D). Thereafter, the medium-pressure vapor refrigerant flowing out of the refrigeration cooler 7 exchanges heat with the refrigeration capillary 6 and flows into the compressor (E).

  The remaining one divided by the electric flow path switching valve 5 flows into the low cooling load capillary 10 for refrigeration. The low cooling load capillary 10 decompresses and expands to a low-temperature and low-pressure gas-liquid two-phase refrigerant while exchanging heat with the suction pipe 14 connected to the freezer outlet (F). The refrigeration cooler 13 removes heat from the air in the freezer compartment to evaporate and gas (G), and cools the freezer compartment. Thereafter, the low-pressure, vapor refrigerant exchanges heat with the low cooling load capillary 10 and flows into the low-stage compression section 3 of the compressor 1 via the suction pipe 14 connected to the low-stage compression section of the compressor 1 (H ).

  The low-pressure vapor refrigerant that has flowed out of the freezer cooler is compressed by the low-stage compression unit 3 to the medium-pressure vapor refrigerant and discharged (I). The discharged intermediate pressure refrigerant merges with the intermediate pressure vapor refrigerant that has flowed in from the refrigerator 8 for the refrigerator compartment, and is sucked into the high-stage compression unit 2 (J). In the high stage side compression part 2, it compresses from a medium pressure vapor refrigerant to a high pressure, high temperature refrigerant (A), and flows into the condenser 4 again.

  Next, the operation of the refrigeration cycle when only the freezer compartment is cooled will be described with reference to FIGS. FIG. 8 is a Ph diagram when only the freezer compartment is cooled, and the symbols in the figure indicate the same positions as those shown on the refrigerant circuit of FIG.

  The high-temperature and high-pressure vapor refrigerant (A) discharged from the high-stage compression unit 2 of the compressor 1 releases heat to the outside of the refrigerator by the condenser 4 to be condensed and liquefied (B). Thereafter, the refrigerant flows into only the high cooling load capillary 11 for freezing by the electric flow path switching valve 5. This high-cooling load low-temperature capillary 11 decompresses and expands into a low-pressure, low-temperature gas-liquid two-phase refrigerant while exchanging heat with the suction pipe connected to the freezer compartment outlet (C). The refrigerating cooler 13 takes heat from the air in the freezing chamber to evaporate and cools the freezing chamber (D). Thereafter, the low-pressure, vapor refrigerant exchanges heat with the refrigeration high-cooling load capillary tube 11, and passes through the suction pipe 11 connected to the low-stage compression unit 3 of the compressor 1 to the low-stage compression unit of the compressor 1. Flow in (E).

  The low-pressure vapor refrigerant that has flowed out of the freezer cooler is compressed to the medium-pressure vapor refrigerant by the low-stage compression unit 3 and discharged (I). The discharged intermediate pressure refrigerant is sucked into the high-stage compression unit 2 while partially sucking the medium pressure vapor refrigerant from the refrigerator for the refrigerator compartment. In the high stage side compression section, the medium pressure vapor refrigerant is compressed to high pressure and high temperature refrigerant (A) and flows into the condenser 4 again.

  If the temperature detection means 14 in the freezer compartment is lower than the preset temperature and the temperature detection means 13 in the refrigerator compartment is larger than the preset temperature, first, the refrigerator for the refrigerator compartment is operated, The inside of the refrigerator is cooled by the melting heat of frost adhering to the refrigerator for the refrigerator compartment. When the preset time has elapsed, or when the value detected by the refrigeration cooler temperature detection means disposed in the refrigeration cooler 8 is greater than a preset value, the electric flow path switching valve 6 is set in the refrigerator compartment. The compressor 1 is operated under control so as to communicate with the capillary tube 6 and the operation of cooling the refrigerator compartment is performed.

  Next, when the value detected by the ambient temperature detection means 29 is large and the cooling load is large, the rotational speed of the compressor 1 and the rotational speeds of the refrigerator compartment fan 24 and the freezer compartment fan 25 are set large. In addition, capillaries for freezer cooling are selected for high cooling loads.

  When the freezing thermistor 22 and the refrigeration thermistor 21 serving as temperature detection means for the freezer compartment and the refrigerator compartment detect temperatures higher than the preset temperatures TsetF and TsetR, respectively, the electric flow path switching valve 5 is used for refrigeration. Both the capillary 6 and the high cooling load capillary 11 used when the cooling load selected according to the ambient temperature is large are in communication with each other, and the compressor 1, the refrigerator compartment fan 22 and the freezer compartment fan 24 are operated. The operation of cooling the freezer compartment 27 and the refrigerator compartment 26 at the same time is performed.

  The operation of the refrigeration cycle is a simultaneous operation of the freezing room and the refrigerating room when the cooling load described above is small, and thus description thereof is omitted. Since the rotation speed of the compressor is larger than when the cooling load is small, the circulation amount of the refrigerant is large. Therefore, in a capillary with a large resistance selected for when the cooling load is small, an efficient operation using the refrigeration cooler effectively cannot be performed if the number of rotations increases when the cooling load is large. Therefore, a capillary having a low resistance (which allows a large amount of refrigerant to flow) is selected as a high-load capillary according to the rotational speed of the compressor.

  In the two-stage compression cycle of the refrigerator-freezer controlled in this way, the compressor may be stopped. However, when the compressor is stopped, the refrigerant is accumulated in the refrigeration cooler 8 and the refrigeration cooler 13, and the compressor is compressed. Liquid refrigerant may flow into the compressor when the machine is started. In the present embodiment, a description has been given of a type in which the inside of the compressor 1 is held at a low pressure. However, in such a type, a low-stage compression unit of the compressor 1 is connected to a pipe to which an outlet of the refrigeration cooler is connected. Since 3 is once connected via the compressor shell, the liquid refrigerant does not flow directly into the compression section. However, since the piping is directly connected to the suction portion of the high-stage compression portion of the compressor 1 to which the refrigeration cooler 8 outlet piping is connected, there is a possibility that the liquid refrigerant flows at the time of startup. Therefore, in the present embodiment, an accumulator 15 is installed in the middle of the outlet-side piping of the refrigeration cooler 8 to suppress the liquid refrigerant flowing into the high-stage compression unit 2 at the time of activation.

  In the present embodiment, the compressor 1 has been described as a low pressure shell type. However, the present invention is not limited to this type. For example, if the compressor is of a type in which the inside of the compressor is held at an intermediate pressure, the compressor suction shown in FIG. The accumulator 15 may be installed in the middle of the outlet side piping of the refrigeration cooler as shown in the main part refrigerant circuit diagram on the side. Furthermore, if the compressor 1 is a high-pressure shell type, as shown in the refrigerant circuit diagram of the main part of FIG. 12, accumulators 15a and 15b are provided in the middle of the outlet side piping of the refrigeration cooler and the refrigeration cooler, respectively. Install it.

  Next, the above-described defrosting operation will be described with reference to FIGS. 5, 9 and 10. TevaRth shown in the figure is a value detected by a thermistor as a refrigerator temperature detector, TevaFth is a value detected by a thermistor as a refrigerator temperature detector, and Tset-evaR is a refrigerator stored in the controller 23 in advance. The defrosting end set temperature of the room cooler, Tset-evaF, is the defrosting end set temperature of the freezer cooler, which is stored in the controller 23 in advance.

  Comparing the compressor integrated time tCOMP and the freezer only electric heater defrosting operation setting integrated time tsetCOMP1 and the simultaneous electric heater defrosting operation setting integrated time tsetCOMP2 for the refrigerator and freezer compartments, and setting the integrated time determined by the ambient temperature When tCOMP is greater than the value tsetCOMP1, the defrosting operation is performed only in the freezer compartment, and when it is greater than tsetCOMP2, the simultaneous electric heater defrosting operation is performed in the refrigerator compartment and the freezer compartment.

  FIG. 9 is a control flow for refrigerating / freezing simultaneous defrosting operation when the refrigerating room and freezing room simultaneous electric heater defrosting operation is performed. First, the compressor 1, the refrigerating room fan, and the freezing room fan are stopped, and then the refrigerating room defrosting heater and the freezing room defrosting heater are energized (S21).

  The value TevaRth detected by the thermistor, which is the refrigerator temperature detector, is compared with the set temperature Tset-evaR of the refrigerator defroster stored in the controller 23 in advance (S22), and the detected temperature becomes higher than the set temperature. If this happens, energization of the refrigerator defrost heater is terminated (S23). If low, continue energization.

  Next, the value TevaFth detected by the thermistor as the freezer cooler temperature detecting means is compared with the defrosting end set temperature Tset-evaF of the freezer cooler previously stored in the controller 23 (S24), and the detected temperature is determined from the set temperature. When becomes high, the energization to the freezing room defrosting heater is terminated (S25). When it is low, energization is continued and the operation completion determination of the refrigerating room defrost heater is repeated again.

  If the detected temperature is lower than the freezer defrosting end set value, it is determined whether or not the refrigerating room defrosting operation has been completed (S26). When the refrigerating room defrosting operation is not completed, the refrigerating room defrosting operation determination is repeated. When the refrigerating room defrosting operation is completed, the defrosting operation is terminated as the entire refrigerator-freezer (S18), and the cooling operation is performed (S13).

  Next, the electric heater defrosting operation only in the freezer compartment will be described. FIG. 10 shows the defrosting operation control flow only in the freezer compartment.

  First, the operation of the freezer compartment fan is stopped, and the freezer compartment defrost heater is energized (S31). Next, the value Rth detected by the refrigeration thermistor 21 serving as the refrigeration room temperature detection means is compared with the set value Tset-R stored in the controller in advance (S32). The path switching valve 5 is controlled to communicate with the refrigeration capillary 6 and the operation of the refrigeration room fan and the compressor 1 is continued, and only the refrigeration room is cooled (S33). When the detected value is smaller than the set value, the operation of the refrigerator compartment fan and the compressor is stopped.

  Next, the value TevaFth detected by the thermistor as the freezer cooler temperature detection means is compared with the defrosting end set temperature Tset-evaF of the freezer cooler previously stored in the controller 23 (S34), and the detected temperature is determined from the set temperature. When becomes higher, energization to the freezing room defrosting heater is terminated (S16), and normal cooling operation control is performed (S13). If the temperature is low, energization is continued, and the process of detecting the temperature of the refrigerator again is repeated.

  In the present embodiment, a case has been described in which one capillary for refrigeration is used, two capillaries for low cooling load for freezing and two capillaries for high cooling load are used, but a total of three capillaries are used. As shown in the refrigerant circuit diagram of the refrigerator, a low load refrigeration capillary 6, a high load refrigeration capillary 40, a low cooling load refrigeration capillary 10, a high cooling load refrigeration capillary 11, a total of four capillaries may be used. good. In the figure, reference numeral 40 denotes a high load load which is a fourth expansion means for cooling the refrigerator compartment disposed between the electric flow switching valve 5 and the refrigerator cooler 8 in parallel with the capillary tube 6 for low load. This is a refrigerated capillary, and the same or corresponding parts as in FIG.

  FIG. 14 shows a cross-sectional structure diagram of the flow path switching valve 5 when four capillaries are used. This valve can be connected to either a low-cooling load refrigeration capillary or two types of freezer capillaries (d) or (f), either a high-cooling load refrigeration capillary or two types of freezer capillaries. Both can be connected (e) (g). Furthermore, it can be connected (h) only to the high-load freezer compartment capillary, and can be fully closed (c).

  In addition, using a conventionally used three-way flow switching valve, a load refrigeration capillary, a high load refrigeration capillary, a low cooling load refrigeration capillary, a high cooling load refrigeration capillary, a total of four capillaries were used. A refrigerant circuit is shown in FIG. One of the flow path switching valves is connected by combining a refrigerated capillary tube for low cooling load and a frozen capillary tube, and the other one is connected by combining a refrigerated capillary tube for low cooling load and a frozen capillary tube.

  Further, in the present embodiment, the freezer capillary and the refrigerating chamber capillary are individually provided from the outlet of the condenser. However, as shown in FIG. 16, a three-way flow switching valve is installed at the outlet of the refrigerating capillary. A low-cooling load freezing chamber capillary tube may be connected to a high-load freezing capillary tube on the other side, and a refrigerating cooler connection pipe may be connected from the middle of the pipe connecting the low-load freezing capillary tube. .

  As described above, in this embodiment, the two-stage compression cycle is applied to the refrigerator-freezer, and the amount of squeezing is adjusted by switching the capillaries. Therefore, when cooling the freezer compartment and the refrigerator compartment at the same time, according to the cooling load. The operation becomes possible and the refrigeration cycle can always be operated with high efficiency, so that the compressor input can be greatly reduced, and the power consumption can be greatly reduced.

  Furthermore, since the flow path switching means is installed and a plurality of capillaries for the freezer compartment are installed so that only the freezer compartment can be cooled, the freezer compartment can be efficiently cooled even when the cooling load on the refrigerator is large.

  Furthermore, since the flow path switching means is arranged upstream of the capillary tube, the compressor suction pressure can be appropriately controlled and cycle efficiency can be increased by setting the capillary tube in consideration of the pressure loss.

  Furthermore, since the operation of the refrigerator-freezer is controlled using the refrigerator compartment temperature detection means, the freezer compartment temperature detection means, and the ambient temperature detection means, an efficient operation can be realized.

  Because the four-way electric flow path switching valve is provided, only the freezer compartment can be cooled when the load increases suddenly so that a large amount of objects to be cooled is put into the freezer compartment, and the refrigerator compartment is not cooled more than necessary. It is possible to improve the temperature control quality of the refrigerator compartment as well as energy saving.

  In addition, since the cycle efficiency is significantly better than the conventional refrigerator, the freezer cooler and the refrigerator cooler can be downsized while maintaining the same performance as the conventional refrigerator. Even if is used, the refrigerant charging amount can be reduced as compared with the conventional case, and the safety is further improved.

  In the present embodiment, the case where the hydrocarbon refrigerant R600a (isobutane) is used as the refrigerant has been described. However, the present invention is not limited thereto, and hydrocarbon refrigerants such as R600 (butane) and R290 (propane), ammonia, carbon dioxide, and the like. Natural refrigerant, or a mixed refrigerant thereof. Moreover, HFC type | system | group fluorocarbon refrigerant | coolants with small global warming coefficients, such as R134a, R32, and R152a, or those mixed refrigerants may be sufficient.

  Furthermore, although it does not specify clearly about the refrigerating machine oil used by embodiment, synthetic oils, such as mineral oil, alkylbenzene, ester oil, ether oil, and PAG oil, may be sufficient.

  Furthermore, the compressor used in the embodiment is not particularly specified, but the reciprocating type, rotary type, scroll type, etc., it is sufficient if there are two or more compression parts, and the pressure in the compressor is maintained at a high pressure. Any of a high-pressure shell type, a low-pressure shell type in which the pressure in the compressor is held at a low pressure, or a medium pressure shell type in which the pressure in the compressor is held at a medium pressure may be used.

  Furthermore, although it is not specified in particular about the condenser used in the embodiment, either the natural convection type in which the copper pipe embedded in the side wall of the refrigerator and the outer plate are in contact or the forced convection type using a blowing means is used. Type may be used.

It is a refrigerant circuit figure of the refrigerator-freezer concerning Embodiment 1 of this invention. It is side surface sectional drawing of the refrigerator-freezer concerning Embodiment 1 of this invention. It is a side view of the flow-path switching valve concerning Embodiment 1 of this invention. It is sectional drawing of the flow-path switching valve concerning Embodiment 1 of this invention. It is a driving | operation control flowchart of the refrigerator-freezer by Embodiment 1 of this invention. It is a driving | operation control flowchart of the refrigerator-freezer by Embodiment 1 of this invention. It is a Ph diagram of a refrigerator-freezer according to Embodiment 1 of the present invention. It is a Ph diagram of a refrigerator-freezer according to Embodiment 1 of the present invention. It is a driving | operation control flowchart of the refrigerator-freezer by Embodiment 1 of this invention. It is a driving | operation control flowchart of the refrigerator-freezer by Embodiment 1 of this invention. It is another refrigerant circuit diagram of the refrigerator-freezer according to Embodiment 1 of the present invention. It is another refrigerant circuit diagram of the refrigerator-freezer according to Embodiment 1 of the present invention. It is another refrigerant circuit diagram of the refrigerator-freezer according to Embodiment 1 of the present invention. It is a side view of the other flow-path switching valve concerning Embodiment 1 of this invention. It is another refrigerant circuit diagram of the refrigerator-freezer according to Embodiment 1 of the present invention. It is another refrigerant circuit diagram of the refrigerator-freezer according to Embodiment 1 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 High stage side compression part, 3 Low stage side compression part, 4 Condenser, 5 Electric flow-path switching valve, 6 Capillary for refrigeration (1st expansion means), 7 Heat recovery heat exchanger for refrigeration, 8 Refrigerating room cooler, 9 High-stage suction pipe, 10 Freezing capillary (second expansion means), 11 Freezing cryogenic capillary (third expansion means), 12 Freezing heat recovery heat exchanger, 13 Freezing Cooler for room, 14 Lower stage suction pipe, 15 Accumulator, 17 Switching valve body, 18 Drive motor, 19 Valve seat, 20 Valve body, 21 Refrigerated thermistor (temperature detection means for refrigerated room), 22 Refrigerated thermistor (freezer room) Temperature detecting means), 23 controller, 24 refrigerator room air blowing means, 25 freezer room air blowing means, 26 refrigerator room, 27 freezing room, 28 vegetable room, 29 ambient temperature detecting means, 30 refrigerator room defrost heater, 31 Defrost for refrigeration room 40, a capillary tube which is a refrigerated capillary tube (fourth expansion means) for high load.

Claims (3)

An electric motor and a compression element driven by the electric motor are provided in the hermetic container, and the compression element includes a low-stage compression unit and a high-stage compression unit, and a low-stage compression of the compressor. And a high-stage compression section, a condenser, a flow path switching means, a first expansion means connected to the flow path switching means and flowing the refrigerant to the refrigerator for the refrigerator compartment, and connected to the flow path switching means for the freezer compartment A refrigeration cycle comprising a second expansion means for a low cooling load and a third expansion means for a high cooling load, which are provided in parallel so as to allow the refrigerant to flow to the cooler, a refrigerator temperature detection means, and a freezer An internal temperature detection means, an ambient temperature detection means, a refrigerator compartment internal fan and a freezer compartment internal fan, wherein the refrigerator internal temperature detection means and the freezer internal temperature detection means are each higher than a preset set temperature. Is detected, the flow path The replacement means communicates both the first expansion means and the second expansion means, and the temperature detected by the refrigerator temperature detection means is lower than a set temperature and is detected by the freezer temperature detection means. When the temperature is higher than the set temperature, only the third expansion means communicates with the flow path switching means , the temperature detected by the refrigerator temperature detection means is greater than the set temperature, and the freezer temperature detection means When the detected temperature is lower than the set temperature and it is determined that only the refrigerating room needs to be cooled, the flow path switching unit causes both the first expansion unit and the second expansion unit to communicate with each other, thereby refrigeration. A refrigerator-freezer controlled to cool a room and a freezer simultaneously . 2. The refrigerator-freezer according to claim 1 , wherein the refrigerator is controlled so as to determine a compressor speed based on a signal detected by the ambient temperature detecting means. When the ambient temperature detected by the ambient temperature detection means is lower than a preset temperature, and the cooling load is small, the second expansion means is selected as the expansion means for cooling the freezer in the flow path switching means. and, if the ambient temperature is high is higher cooling load than the set temperature, the freezing refrigerator according to claim 1 or claim 2, wherein selecting said third expansion means in said flow path switching unit .

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