JPWO2016079880A1 - Refrigerator and refrigerant flow rate control method - Google Patents

Abstract

A refrigerator, a storage chamber, a compressor, a radiator, a plurality of capillaries each having a different Cv value, a selection means for selecting at least one of the capillaries, and a cooler are connected by piping to circulate the refrigerant A refrigerant circuit that causes the refrigerant to flow through the selected capillary tube, a first sensor that outputs a first sensor value based on detection of the evaporation temperature of the refrigerant or the evaporation pressure of the refrigerant, and the refrigerant A second sensor that outputs a second sensor value based on detection of at least one of the condensing temperature and the condensing pressure of the refrigerant, a flow rate of the refrigerant based on the rotational speed of the compressor, and a first sensor value And a control means for controlling the selection means based on the second sensor value.

Description

  The present invention relates to a refrigerator that performs refrigerant flow control and a refrigerant flow control method.

  As a general refrigerator, a storage room, a refrigerant circulation circuit, a cooling room provided with a cooler, a blower that sends cold air from the cooling room to the storage room, and an air passage that connects the cooling room and the storage room What you have is known. The refrigerant circulation circuit is configured by connecting a compressor, a radiator, a decompression device (capillary tube), and a cooler with piping. As the refrigerant circulates in the refrigerant circuit, the refrigerant repeatedly changes in the state of evaporation, compression, condensation, and expansion, and the storage chamber is cooled by utilizing the movement of heat during evaporation.

  In the case of a conventional refrigerator, the flow rate of the refrigerant supplied to the cooler is determined by the rotation speed of the compressor and the diameter of the capillary tube. Further, the stroke volume of the compressor and the diameter of the capillary tube are determined and determined from the maximum load point (for example, summer) and the minimum load point (for example, winter) of the refrigerator. Thus, when using a capillary tube designed with the maximum load point and the minimum load point, the adjustment of the refrigerant flow rate inevitably depends only on the rotation speed of the compressor at the other load points. For example, when the outside air temperature is low or the load in the warehouse is small, the rotation speed of the compressor is shifted to the low speed side within the adjustable range, and the refrigerant flow rate is reduced within the adjustable range. Reduce the amount of work. However, even when the load amount is equal to or lower than the lower limit of the refrigerant flow rate adjustment range by adjusting the rotation speed of the compressor, the same refrigerant flow rate is supplied to the cooler, so that the density of refrigerant gas sucked into the compressor becomes high. As a result, the load on the compressor is increased, and the power consumption cannot be reduced.

  Therefore, in order to more appropriately adjust the refrigerant flow rate, Patent Document 1 proposes a refrigerator that includes two capillaries having different diameters and switches the two capillaries according to the outside air temperature or the amount of internal load. . Specifically, the refrigerator described in Patent Document 1 further includes a three-way valve connected to two capillaries and temperature sensors disposed at the inlet and outlet of the cooling chamber. Then, from the outputs of these temperature sensors, the temperature difference between the inlet and outlet of the cooling chamber is obtained and compared with the target temperature difference, and the three-way valve is controlled so as to switch the two capillaries according to the comparison result.

JP 2003-14357 A

  However, in the configuration described in Patent Document 1, as a switching pattern of two capillaries, it is limited to flowing a refrigerant through one of the two capillaries and when flowing a refrigerant through both capillaries, The power consumption cannot be reduced at load points other than the design load point (for example, when the door is opened and closed and the internal temperature rapidly rises). On the other hand, by using many capillaries having different diameters, it is possible to realize adjustment of the refrigerant flow rate according to more load points, but in this case, there is a problem that the product cost increases. is there.

  This invention is for solving the above problems, and provides a refrigerator capable of realizing energy saving by appropriately adjusting the amount of refrigerant supplied to the cooler according to the operating state of the refrigerator. For the purpose.

  The refrigerator according to the present invention includes a storage chamber, a compressor, a radiator, a plurality of capillaries each having a different Cv value, a selection unit that selects at least one of the capillaries, and a cooler connected by piping. A refrigerant circuit that circulates the refrigerant, a refrigerant circuit through which the refrigerant flows through the selected capillary, and a first sensor that outputs a first sensor value based on detection of the evaporation temperature of the refrigerant or the evaporation pressure of the refrigerant; A second sensor that outputs a second sensor value based on detection of at least one of the refrigerant condensing temperature and the refrigerant condensing pressure, a refrigerant flow rate based on the number of revolutions of the compressor, Control means for controlling the selection means based on the sensor value and the second sensor value.

  In the refrigerator according to the present invention, by selecting at least one of the plurality of capillaries on the basis of the rotational speed of the compressor, the evaporation temperature, the condensation temperature, and the like, an optimal refrigerant supply amount can be obtained according to the operating state of the refrigerator. Can be supplied to the cooler. As a result, it is possible to suppress excess or deficiency of the refrigerant flow rate, reduce the burden on the compressor, and realize energy saving.

It is a schematic block diagram of the refrigerator in embodiment of this invention. It is a structural diagram of the refrigerant circuit in the embodiment of the present invention. It is a control block diagram of the refrigerator in the embodiment of the present invention. It is a schematic diagram of the three-way valve in the embodiment of the present invention, (a) is a flow path in the first stage, (b) is a flow path in the second stage, (c) is a flow path in the third stage, (d ) Shows the flow paths in the fourth stage. It is a figure which shows an example of the Cv value map in embodiment of this invention. It is a flowchart which shows the refrigerant | coolant flow control process in embodiment of this invention. It is a figure explaining an example of selection of a channel by a three-way valve in an embodiment of the invention. It is a figure explaining another example of selection of a channel by a three-way valve in an embodiment of the invention.

  Embodiments of a refrigerator and a refrigerant flow rate control method according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a refrigerator 100 in the embodiment of the present invention, and FIG. 2 is a structural diagram of a refrigerant circulation circuit 10 provided in the refrigerator 100. The refrigerator 100 includes a plurality of storage chambers 9a and 9b formed inside a box (not shown), a blower 6, an air volume regulator 7, a cooling chamber 8 including a cooler 4, and a refrigerant circulation circuit 10. And a controller 50. In addition, an internal temperature sensor 21 for detecting the temperature in the storage room 9a is arranged in the storage room 9a, and an internal temperature sensor 22 for detecting the temperature in the storage room 9b is arranged in the storage room 9b. Further, the cooler 4 is provided with an evaporation temperature sensor 23 that detects the evaporation temperature of the refrigerant, and the radiator 2 is provided with a condensation temperature sensor 24 that detects the condensation temperature of the refrigerant. The evaporation temperature sensor 23 and the condensation temperature sensor 24 correspond to the first sensor and the second sensor of the present invention, respectively. The evaporation temperature and the condensation temperature detected by the evaporation temperature sensor 23 and the condensation temperature sensor 24 are output to the controller 50. The evaporation temperature and the condensation temperature correspond to the first sensor value and the second sensor value of the present invention, respectively.

  As shown in FIGS. 1 and 2, the refrigerant circulation circuit 10 includes a compressor 1, a radiator 2, a capillary 3, a cooler 4, and a three-way valve 5. The compressor 1 compresses the refrigerant in the refrigerant circulation circuit 10. The radiator 2 condenses the refrigerant compressed by the compressor 1. The capillary tube 3 is a decompression device, and decompresses the refrigerant condensed by the radiator 2. In the present embodiment, the capillary 3 is composed of two capillaries 3a and 3b that are different in at least one of diameter and length. The capillaries 3a and 3b correspond to the first and second capillaries of the present invention, respectively. The three-way valve 5 corresponds to the selection means of the present invention, and has one inlet channel 5a and two outlet channels 5b and 5c. The three-way valve 5 opens and closes the two outlet channels 5b and 5c to select a refrigerant channel. The outlet channel 5b is connected to the capillary 3a, and the outlet channel 5c is connected to the capillary 3b. The cooler 4 evaporates the refrigerant decompressed by the capillary 3. The compressor 1, the radiator 2, the capillary 3, and the cooler 4 are connected in order to constitute a refrigeration cycle of the refrigerator 100.

  In the refrigerator 100, the high-temperature high-pressure gas refrigerant discharged from the compressor 1 is sent to the radiator 2. In the radiator 2, the refrigerant exchanges heat with the outside air and condenses due to heat dissipation. The condensed high-pressure liquid refrigerant is decompressed by the capillary 3 and becomes a low-pressure and low-temperature refrigerant. Thereafter, the refrigerant flows into the cooler 4 disposed in the box of the refrigerator 100 and exchanges heat with the air in the cooling chamber 8. Thereby, the air in the cooling chamber 8 is cooled by the refrigerant, and the refrigerant becomes a low-pressure gas refrigerant. The air cooled in the cooling chamber 8 is conveyed by the blower 6 and flows into the storage chambers 9a and 9b through the air passages (arrow lines in FIG. 1) connected to the storage chambers 9a and 9b, respectively. Thereby, the storage chambers 9a and 9b are cooled.

  The refrigerant that has become low-pressure gas in the cooler 4 flows into the compressor 1. Then, it is pressurized again by the compressor 1 and discharged as a high-temperature high-pressure gas refrigerant. The cooling air that has cooled the storage chambers 9a and 9b flows again into the cooling chamber 8 through the return air passage and is cooled again by the cooler 4.

  FIG. 3 is a control block diagram of the refrigerator 100. The controller 50 is a control means composed of, for example, a microcomputer or the like. Connected. The controller 50 includes an air volume control unit 51, a refrigerant flow rate control unit 52, and a storage unit 53. The air volume control unit 51 changes the rotation speed of the blower 6 or the operation amount of the air volume adjuster 7 according to the output values of the internal temperature sensors 21 and 22 arranged in the storage chambers 9a and 9b, respectively. . Thereby, the air volume of cooling air is adjusted and the temperature of each store room 9a and 9b is adjusted. In this embodiment, the inside temperature sensors 21 and 22 are arranged in all the storage rooms 9a and 9b, but the present invention is not limited to this, and at least one storage room that controls the temperature to be constant is provided. A temperature sensor may be arranged. Further, the positions of the internal temperature sensors 21 and 22 are not limited to the positions shown in FIG. 1, and may be arranged anywhere as long as they represent the temperatures of the storage chambers 9a and 9b.

  The refrigerant flow rate controller 52 controls the three-way valve 5 based on the output values of the evaporation temperature sensor 23 and the condensation temperature sensor 24 that detect the evaporation temperature and the condensation temperature of the refrigerant, respectively, and the rotation speed of the compressor 1. And the flow rate of the refrigerant supplied to the cooler 4 is adjusted. In addition, about the evaporation temperature sensor 23 and the condensation temperature sensor 24, although the evaporation temperature sensor 23 is arrange | positioned in the cooler 4 and the condensation temperature sensor 24 is arrange | positioned in the heat radiator 2 in FIG. 1, it is not limited to this. However, it may be placed anywhere as long as it is representative of the evaporation temperature and the condensation temperature. For example, the evaporating temperature sensor 23 may detect the outlet temperature of the cooler 4 and use this as the evaporating temperature. The storage unit 53 stores data (such as the Cv values of the capillaries 3a and 3b) required for control in the air volume control unit 51 and the refrigerant flow rate control unit 52.

  FIG. 4 is a schematic diagram of the three-way valve 5 in the present embodiment. As shown in FIG. 4, the three-way valve 5 can select four stages of flow paths. FIG. 4A shows the flow path in the first stage. In the first stage, both outlet channels 5b and 5c are opened (fully open). Thereby, a refrigerant | coolant flows into both the capillary 3a and the capillary 3b. FIG. 4B shows the flow path in the second stage. In the second stage, the outlet channel 5b is opened and the outlet channel 5c is closed. Thereby, a refrigerant | coolant flows only into the capillary 3a connected to the exit flow path 5b. FIG. 4C shows the flow path in the third stage. In the third stage, the outlet channel 5c is opened and the outlet channel 5b is closed. Thereby, a refrigerant | coolant flows only into the capillary 3b connected to the exit flow path 5c. FIG. 4D shows the flow path in the fourth stage. In the fourth stage, both the outlet channels 5b and 5c are closed (fully closed). Thereby, a refrigerant | coolant does not flow into any of the capillary 3a and the capillary 3b.

  If the refrigerant is excessively depressurized by the capillary tube 3 in a general operation state of the refrigerant circulation circuit 10 (a certain compressor rotation speed, outside air temperature, internal temperature), the amount of refrigerant flowing in the refrigerant circulation circuit 10 decreases. However, the cooling capacity is insufficient. On the other hand, if the capillary 3 is not properly depressurized, the circulation rate of the refrigerant increases, but the difference between the refrigerant pressure (high pressure side) in the radiator 2 and the pressure (low pressure) side in the cooler 4 cannot be secured, and the refrigerator The inside of 100 cannot be cooled sufficiently. Therefore, there is a flow coefficient Cv as a throttle amount that allows the refrigerant circulation circuit 10 to be operated efficiently, and is expressed by the following equation (1).

G: Flow rate [kg / h] (rotation speed of the compressor 1)
ρ ・ ・ ・ High-pressure liquid refrigerant density [kg / m ³ ]
Pc: Condensation pressure [MPa]
Pe: Evaporation pressure [MPa]
a: Constant [-]

  Here, the condensation pressure Pc can be calculated from the output value of the condensation temperature sensor 24 that detects the condensation temperature, and the evaporation pressure Pe can be calculated from the output value of the evaporation temperature sensor 23 that detects the evaporation temperature. In refrigerator 100, since the refrigerant state at the outlet of radiator 2 is liquid refrigerant, high-pressure liquid refrigerant density ρ can be calculated from the output value of condensation temperature sensor 24 that detects the condensation temperature. Further, the flow rate G can be calculated from the rotational speed of the compressor 1. Moreover, an appropriate Cv value can be calculated by setting the constant a to a numerical value within 0.3 to 0.45.

FIG. 5 shows the relationship between the Cv value (hereinafter referred to as “Cvp”) obtained by the equation (1), the condensing pressure Pc, the evaporating pressure Pe, and the rotation speed (soot flow rate G) of the compressor 1. FIG. 5 is an example of the Cv value map. In FIG. 5, the horizontal axis indicates the rotation speed (flow rate) of the compressor 1 and the vertical axis indicates the Cv value. FIG. 5 shows a map of Cv values in three examples where the difference (Pc−Pe) between the condensation pressure and the evaporation pressure in the refrigerator 100 is ΔP ₁ , ΔP _2, and ΔP ₃ . Specifically, ΔP ₁ is 7.0 (MPa), ΔP ₂ is 9.0 (MPa), and ΔP ₃ is 11.4 (MPa).

  In FIG. 5, Cva indicates the Cv value of the capillary 3a, and Cvb indicates the Cv value of the capillary 3b. The Cv value of each capillary varies with the diameter and length. As shown in FIG. 5, in this embodiment, the Cv value (Cva) of the capillary 3a is larger than the Cv value (Cvb) of the capillary 3b (Cva> Cvb). Further, the Cv value in the first stage of the three-way valve 5 (when the refrigerant flows through both the capillaries 3a and 3b) is the sum of Cva and Cvb (Cva + Cvb). Therefore, the Cv value generated by the selection of the flow path by the three-way valve 5 satisfies the first stage (Cva + Cvb)> the second stage (Cva)> the third stage (Cvb).

  As shown in FIG. 5, the Cv value (Cvp) for operating the refrigerant circuit 10 efficiently varies in proportion to the flow rate. However, as in the prior art, when the refrigerant flows through one of the two capillaries 3a and 3b, or when there is a selection pattern only when the refrigerant flows through both, the Cv value is Cva, Cvb or (Cva + Cvb ) Will be fixed in either. Therefore, in the refrigerant flow rate control process according to the present embodiment, the three-way valve 5 is controlled so that the capillaries 3a and 3b are selected so that an appropriate Cv value (Cvp) according to the operating state is obtained.

  The flow of the refrigerant flow rate control process in the present embodiment will be described with reference to FIGS. FIG. 6 is a flowchart showing the refrigerant amount control process in the present embodiment. This process is started by the refrigerant flow rate control unit 52 of the controller 50 when the door of the refrigerator 100 is opened / closed, the outside air temperature changes, or the rotation speed of the compressor 1 changes. As shown in FIG. 6, in this process, first, the evaporation temperature and the condensation temperature are acquired from the evaporation temperature sensor 23 and the condensation temperature sensor 24, respectively, and the rotation speed is acquired from the compressor 1 (S1). Then, the target Cv value (Cvp) is calculated from the acquired condensing temperature, evaporation temperature, and rotational speed based on the equation (1) (S2). Subsequently, it is determined whether or not Cvp is larger than the first stage Cv value (Cva + Cvb) (S3).

  When Cvp is larger than the Cv value (Cva + Cvb) in the first stage (S3: YES), the three-way valve 5 is fixed in the first stage shown in FIG. 4A (S4). Thereby, a refrigerant | coolant flows into both the capillary 3a and the capillary 3b. On the other hand, if Cvp is equal to or lower than the first-stage Cv value (Cva + Cvb) (S3: NO), it is determined whether Cvp is equal to or lower than the third-stage Cv value (Cvb) (S5). If Cvp is equal to or less than the Cv value (Cvb) in the third stage (S5: YES), the three-way valve 5 is fixed in the third stage shown in FIG. 4C (S6). Thereby, a refrigerant | coolant flows only into the capillary 3b.

On the other hand, when Cvp is larger than the Cv value (Cvb) in the third stage (S5: NO), it is determined whether Cvp is larger than the Cv value (Cva) in the second stage (S7). When Cvp is larger than the Cv value (Cva) in the second stage (S7: YES), the three-way valve 5 is shown in the first stage shown in FIG. 4A and FIG. The second stage is selected alternately (S8). Thereby, a refrigerant | coolant flows alternately into both the capillary tubes 3a and 3b and only the capillary tube 3a. At this time, the time T ₁ that is fixed in the first stage (the time that the refrigerant flows in both the capillaries 3a and 3b) T ₁ and the time that is fixed in the second stage (the time that the refrigerant flows only in the capillaries 3a) T ₂ are , Cvp is variably set. Specifically, as shown in the following formula (2), the refrigerant flow rate control unit 52 sets the time T ₁ and the time T ₁ so that the average Cv value in the cycle T (T ₁ + T ₂ ) becomes the target Cv value (Cvp). setting the T _2.

[Equation 2]
Cvp = ((Cva + Cvb) × T ₁ + Cva × T ₂ ) / T (2)

FIG. 7 is a diagram for explaining an example of selection of a flow path by the three-way valve 5. In FIG. 7, the horizontal axis represents time, and the vertical axis represents Cv value. In the case of the example of FIG. 7, the Cv value (Cvp) calculated in S2 is a value close to the Cv value (Cva) in the second stage, so that the time T ₂ fixed in the second stage is the first stage. It is set to be longer than the time T ₁ fixed to. FIG. 8 is a diagram for explaining another example of selection by the three-way valve 5. Also in FIG. 8, the horizontal axis indicates time, and the vertical axis indicates Cv value. In the case of the example in FIG. 8, the Cv value (Cvp) calculated in S2 is a value close to the Cv value (Cva + Cvb) in the first stage, so that the time T ₁ fixed in the first stage is the second stage. It is set longer than the time T ₂ fixed to. In any case, the average of Cv values in the period T is Cvp. In addition, an arbitrary time can be set as the predetermined period T, but by setting it to 600 seconds or more, the three-way valve 5 is efficiently controlled while ensuring the life of the three-way valve 5. be able to.

  Returning to FIG. 6, when Cvp is equal to or less than the Cv value (Cva) of the second stage (S7: NO), the three-way valve 5 is moved to the second stage shown in FIG. Selection is alternated with the third stage shown in (c) (S9). Thereby, a refrigerant | coolant flows alternately into the capillary 3a and the capillary 3b. Also in this case, the refrigerant flow rate control unit 52 fixes the second stage so that the average of the Cv values in the cycle T becomes the target Cv value (Cvp), as in the process of S8 (only the capillary 3a only). And the time for which the refrigerant flows in the third stage (the time for which the refrigerant flows only in the capillary tube 3b).

  As described above, in the refrigerator 100 of the above embodiment, the target Cv value corresponding to the operating state of the refrigerator 100 is obtained, and the refrigerant flow path (capillary tubes 3a and 3b) is obtained by the three-way valve 5 so that the target Cv value is obtained. By selecting this, it becomes possible to supply the optimum refrigerant flow rate for the internal load. Thereby, the excess and deficiency of the refrigerant in the refrigerant circuit 10 is suppressed, and the load on the compressor 1 can be reduced and the power consumption can be reduced.

  Further, by selecting a plurality of capillaries 3a and 3b with the three-way valve 5, fine flow rate control becomes possible, and the refrigerant supply amount to the cooler 4 is appropriately adjusted even at a load point other than the load point at the time of design. be able to. Specifically, when the target Cv value (Cvp), which is a load point other than the design point, is equal to or lower than the first stage Cv value (Cva + Cvb) and greater than the second stage Cv value (Cva), or Even when the Cv value (Cvp) is smaller than the second stage Cv value (Cva) and larger than the third stage Cv value (Cvb), the refrigerant supply amount can be appropriately adjusted. Thereby, the energy saving property of the refrigerator 100 can be improved. Further, by configuring the capillary tube 3 with two, it is possible to improve power consumption while suppressing the product cost.

  The above is the description of the embodiment of the present invention. However, the present invention is not limited to the configuration of the above embodiment, and various modifications or combinations are possible within the scope of the technical idea. For example, although the case where the refrigerator 100 includes one cooler 4 has been described in the above embodiment, the present invention can be applied to a refrigerator including a plurality of coolers.

  Moreover, in the said embodiment, although it became the structure which calculates evaporation pressure and a condensation pressure based on the output value of the evaporation temperature sensor 23 and the condensation temperature sensor 24, it is not limited to these. For example, instead of (or in addition to) the evaporation temperature sensor 23 and the condensation temperature sensor 24, an evaporation pressure sensor that detects the evaporation pressure and a condensation pressure sensor that detects the condensation pressure may be provided. The high pressure liquid refrigerant density ρ may be a fixed value stored in the storage unit 53 in advance.

  In the above embodiment, the two capillaries 3a and 3b are selected by the three-way valve 5. However, three or more capillaries are selected by a selection means other than the three-way valve 5 (such as a four-way valve). It is also good.

  Moreover, in said embodiment, since the frequency | count of selection by the three-way valve 5 may increase, it is good also as a structure provided with a soundproof material around the three-way valve 5. By comprising in this way, the silence of the refrigerator 100 can be improved and the comfort to a user can be maintained.

  Furthermore, in the refrigerant flow rate control process in the above embodiment, when the calculated Cv value (Cvp) is equal to or lower than the third-stage Cv value (Cvb) (S5: YES), the three-way valve 5 is changed to FIG. (S6), but is not limited to this. For example, the three-way valve 5 may be configured to alternately select the third stage shown in FIG. 4C and the fourth stage (fully closed state) shown in FIG. As a result, a state in which the refrigerant flows only in the capillary 3b and a state in which the refrigerant does not flow in any capillary are alternately selected. Also in this case, the time is fixed at the third stage (the time when the refrigerant flows only in the capillary 3b) and the fourth stage so that the average of the Cv values in the period T becomes the target Cv value (Cvp). The time (full closing time) is set according to the calculated Cv value (Cvp). The target Cv value (Cvp) is not only calculated from the equation (1), but may be obtained from a table prepared in advance according to the flow rate, the condensation pressure, and the evaporation pressure.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Radiator, 3, 3a, 3b Capillary tube, 4 Cooler, 5 Three-way valve, 5a Inlet flow path, 5b, 5c Outlet flow path, 6 Blower, 7 Air flow regulator, 8 Cooling chamber, 9a, 9b Storage room, 10 Refrigerant circuit, 21, 22 Internal temperature sensor, 23 Evaporation temperature sensor, 24 Condensation temperature sensor, 50 Controller, 51 Air flow control unit, 52 Refrigerant flow control unit, 53 Storage unit, 100 Refrigerator

The refrigerator according to the present invention includes a storage chamber, a compressor, a radiator, a plurality of capillaries each having a different Cv value, a selection unit that selects at least one of the capillaries, and a cooler connected by piping. A refrigerant circuit that circulates the refrigerant, a refrigerant circuit through which the refrigerant flows through the selected capillary, and a first sensor that outputs a first sensor value based on detection of the evaporation temperature of the refrigerant or the evaporation pressure of the refrigerant; A second sensor that outputs a second sensor value based on detection of at least one of the refrigerant condensing temperature and the refrigerant condensing pressure, a refrigerant flow rate based on the number of revolutions of the compressor, Control means for controlling the selection means based on the sensor value and the second sensor value, wherein the plurality of capillaries have a first capillary having a first Cv value and a first capillary smaller than the first Cv value. Has a Cv value of 2 The second capillary, and the selection means includes a first stage for flowing the refrigerant to both the first capillary and the second capillary, a second stage for flowing the refrigerant only to the first capillary, and a second The third stage for flowing the refrigerant only to the capillary is selected, and the control means selects to periodically select the first stage and the second stage or the second stage and the third stage alternately. that controls the means.

Claims (12)

A storage room;
A compressor, a heat radiator, a plurality of capillaries each having a different Cv value, a selection means for selecting at least one of the capillaries and a cooler connected by a pipe, and a refrigerant circulation circuit for circulating a refrigerant, A refrigerant circuit through which the refrigerant flows through selected capillaries;
A first sensor that outputs a first sensor value based on detection of an evaporation temperature of the refrigerant or an evaporation pressure of the refrigerant;
A second sensor that outputs a second sensor value based on detection of at least one of the condensation temperature of the refrigerant and the condensation pressure of the refrigerant;
A refrigerator comprising: control means for controlling the selection means based on the flow rate of the refrigerant based on the rotation speed of the compressor, the first sensor value, and the second sensor value.   The control means calculates a target Cv value based on the flow rate of the refrigerant, the first sensor value, and the second sensor value based on the rotation speed of the compressor, and based on the calculated target Cv value. The refrigerator according to claim 1, wherein the selection means is controlled.   The refrigerator according to claim 2, wherein the control unit controls the selection unit so that an average of Cv values in the plurality of capillaries becomes the target Cv value. The plurality of capillaries include a first capillary having a first Cv value, and a second capillary having a second Cv value smaller than the first Cv value;
The selection means includes a first stage in which the refrigerant flows through both the first capillary and the second capillary, a second stage in which the refrigerant flows through only the first capillary, and only the second capillary. The third stage of flowing the refrigerant in
The said control means controls the said selection means to select alternately the said 1st stage and the said 2nd stage or the said 2nd stage and the 3rd stage periodically based on the said target Cv value. Refrigerator.   When the target Cv value is less than or equal to the sum of the first Cv value and the second Cv value and greater than the first Cv value, the control means periodically performs the first step and The refrigerator according to claim 4, wherein the selection means is controlled to alternately select the second stage.   When the target Cv value is less than or equal to the first Cv value and greater than the second Cv value, the control means periodically selects the second stage and the third stage alternately. The refrigerator according to claim 4 or 5, wherein the selection means is controlled. The selection means can further select a fourth stage in which the refrigerant does not flow through any of the first capillary and the second capillary,
5. The control unit controls the selection unit to periodically select the third stage and the fourth stage periodically when the target Cv value is equal to or less than the second Cv value. The refrigerator as described in any one of -6.   In the case where the control unit periodically selects the first stage and the second stage, or the second stage and the third stage alternately, a time to be fixed in each stage is set to the target Cv value. The refrigerator as described in any one of Claims 4-7 changed according to.   When the control means periodically selects the first stage and the second stage, or the second stage and the third stage alternately, the control unit sets a time for fixing the Cv value in one cycle. The refrigerator as described in any one of Claims 4-8 set so that an average may become the said target Cv value.   The refrigerator according to any one of claims 1 to 9, wherein at least one of the plurality of capillaries is different in diameter or length.   The refrigerator as described in any one of Claims 1-10 further equipped with the soundproof material arrange | positioned around the said selection means. A storage circuit, a compressor, a radiator, a plurality of capillaries each having a different Cv value, a selection means for selecting at least one of the capillaries and a cooler are connected by piping, and a refrigerant circulation circuit for circulating a refrigerant A refrigerant flow rate control method in a refrigerator, comprising: a refrigerant circuit through which the refrigerant flows in the selected capillary tube; and a control unit.
Outputting a first sensor value based on detection of an evaporation temperature of the refrigerant or an evaporation pressure of the refrigerant;
Outputting a second sensor value based on detection of at least one of the condensation temperature of the refrigerant and the condensation pressure of the refrigerant;
Controlling the selection means based on the flow rate of the refrigerant based on the number of rotations of the compressor, the first sensor value, and the second sensor value.

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