JP2003329354A - Refrigerator refrigerator control device - Google Patents

Abstract

(57) [Problem] Conventionally, when a high refrigerant flow rate is required for high outside air and load fluctuations in a warehouse (door opening / closing, food load, etc.), the valve control flow rate is fixed, so compression is performed. Since control could be performed only within the rotation speed range of the machine, there were problems such as insufficient gas in the cooler, resulting in insufficient cooling capacity. The present invention relates to a refrigerator having a freezer compartment cooler and a refrigerator compartment cooler, and a switching valve for distributing condensed refrigerant to each of the coolers, wherein the plurality of coolers are provided. And a three-way switching valve for controlling the flow rate of the refrigerant flowing through at least one of the coolers in a plurality of stages.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a freezer-refrigerator having a freezer compartment cooler and a refrigerator compartment cooler and having a switching valve for distributing condensed refrigerant to the respective coolers. .

[0002]

2. Description of the Related Art FIG. 17 shows the structure of a conventional refrigerator-freezer having a refrigerator for a freezer and a refrigerator for a refrigerator. In the figure, 1 is a compressor, 2 is a condenser, 3 is a three-way switching valve, 4a is a refrigerating room capillary tube, 4b is a freezing room capillary tube, 5a is a refrigerating room cooler, 5b is a freezing room cooler, 6 Is a check valve, 7a is a defrosting heater for a refrigerating compartment cooler, 7b is a defrosting heater for a refrigerating compartment cooler, 8a is a refrigerating compartment fan, 8b is a freezing compartment fan, 9 is a box body, 10 is a dryer, and 11 is a refrigerating compartment. , 12
Is a chilled room, 13 is a vegetable room, 14 is an ice making machine, 15 is a freezer compartment upper case, 16 is a freezer compartment lower case, 17 is a freezer compartment fan grill, and 18 is a refrigerator compartment fan grill.

Next, the operation of the conventional refrigerator-freezer will be described. The refrigerant is compressed by the compressor 1, enters the condenser 2, and reaches the three-way switching valve 3 via the dryer 10. Here, the thermistors (not shown) attached to the freezer compartment fan grill 17 and the refrigerating compartment fan grill 18 control the three-way switching valve 3 of each flow path to send to each room cooler 5a, 5b. . The role of the conventional three-way switching valve 3 is simply the function of switching the flow path. Further, between the three-way switching valve 3 and each refrigerator compartment cooler 5a and freezer compartment cooler 5b, there are a first capillary tube 4a and a second capillary tube 4b, which are throttle devices having different inner diameters, respectively. 5a, cooler 5 for freezer
b is set to a predetermined evaporation temperature.

18 and 19 are refrigerant circuit diagrams of a conventional refrigerator-freezer having a refrigerator for a freezer compartment and a refrigerator for a refrigerator compartment. Here, a switching valve equipped with a three-way switching valve will be described. In FIG. 18, 1 is a compressor, 2 is a condenser, and 3 is a three-way switching valve, which is connected to the freezer compartment-side capillary tube.
An outlet 3a and a second outlet 3b connected to the refrigerating chamber capillary are provided. Reference numeral 4a denotes a refrigerating room capillary tube, 4b denotes a freezing room capillary tube, 5a denotes a refrigerating room cooler, 5b denotes a freezing room cooler, and 6
Indicates a check valve, and the arrow indicates the flow direction of the refrigerant.

As shown in FIG. 19, the outlet of the refrigerator compartment cooler 5a may be connected to the inlet of the freezer compartment cooler 5b (in front of the freezer compartment capillary 4b). This is because the refrigerant returned to the compressor 1 is passed through the freezer compartment cooler 5b to be completely evaporated and not liquid backed.

In FIG. 18, the refrigerant discharged from the compressor 1 is condensed by the condenser 2 and supplied before the three-way switching valve 3. Regarding the operation of the compressor 1, its start and stop are determined by the F or R thermistor, its start speed is determined by the outside air temperature, and the rotation speed is increased with the continuous operation time thereafter.

The flow path switching is decided, and the refrigerator 5 cooler 5a
Alternatively, the inside of the refrigerator is cooled by supplying a refrigerant to the freezer cooler 5b and evaporating the refrigerant. When the R thermistor reaches the closing point of the three-way switching valve 3, the three-way switching valve is controlled to close the second outlet 3b, the refrigerating compartment fan is also stopped, and cooling of the refrigerating compartment is stopped.

FIG. 20 shows a control flow chart of the compressor, each thermistor, and the three-way switching valve in this case. In FIG. 20,
First, check the operating state of the compressor in step S1 and turn it on.
If so, in step S2, the temperature inside the refrigerator is checked by the F thermistor to determine whether or not cooling is necessary. If it is OFF, in step S6, F
Check the temperature inside the refrigerator with a thermistor to determine if cooling is required. If the F thermistor confirmation temperature is equal to or higher than T2 in step S6, the process proceeds to step S7 and COMP is turned off.
If N and T2 or less, go to step S8 and compare
Turn off. If the F thermistor confirmation temperature in step S2 is T1 or more and cooling is required, the process proceeds to step S3. If the F thermistor confirmation temperature is T1 or less, the first outlet 3a of the three-way switching valve 3 in step S9, 2nd exit 3
b is closed and COMP is turned off in step S10. In step S3, the second outlet 3b side of the three-way switching valve 3 is controlled,
After opening the flow path to allow the refrigerant to flow to the freezer compartment cooler 5b, it is then determined in step S4 whether or not cooling is required by the R thermistor, and if cooling is required at T3 or higher, In step S5, the second outlet 3b side of the three-way switching valve 3 is controlled in the same manner as in step S3, and control is performed to open the flow path so that the refrigerant flows to the freezer compartment cooler 5b. At the same time when each flow path is opened, each fan is operated to send cooled air. If cooling is not necessary at T3 or less, the process proceeds to step S11 to close the first outlet 3a side of the three-way switching valve 3.

FIG. 21 is a time chart showing a time series movement of each element when the outside air is 18 ° C. Figure 2
In 1, the starting rotational speed of each element is determined by the outside air thermistor, and the compressor 1 is controlled by the F thermistor. At this time, also in the three-way switching valve, the valves are switched by the signals of the F and R thermistors to determine opening / closing of the flow path.

FIG. 22 is a starting rotation speed table of each element (compressor 1, freezer compartment fan 8b, refrigerating compartment fan 8a) with respect to the outside air temperature of a conventional refrigerator-freezer. In the figure, N
COMP is a compressor, NF FAN is a freezer fan, N
R FAN is the starting rotation speed of the refrigerator compartment fan.

In the figure, N C
OMP rpm “40”, NR FAN rpm “100
0 ", NF FAN rpm" 1000 ", outside temperature 15
If the temperature is between 20 ° C and 20 ° C, N COMPrpm “50”, N
R FANrpm "1100", NF FANrpm
“1150”, if the outside air temperature is 20 ° C. to 25 ° C., N
COMP rpm “55”, NR FAN rpm “120
0 ", NF FAN rpm" 1200 ", and if the outside air temperature is 25 ° C to 30 ° C, N COMPrpm" 6 "
0 ”, NR FAN rpm“ 1200 ”, NF FAN
If the outside air temperature is 30-at rpm "1250", N
COMP rpm "65", NR FAN rpm "13"
00 "and NF FAN rpm" 1300 ".

However, in these refrigeration cycles, the opening of the three-way switching valve 3 is constant, that is, either fully open or fully closed, and the flow rate is controlled by the capillaries 4a and 4b connected thereafter.

[0013]

In the case of the conventional refrigerator-freezer, the flow rate of the refrigerant supplied to the cooler is determined by the number of revolutions of the compressor and the diameter of the capillary tube, but one flow rate control means is provided for each cooler. Only the capillaries.

When a large amount of refrigerant flow is required for high outside air and load fluctuations (door opening / closing, food load, etc.), the valve control flow rate is fixed, so control is performed only within the rotational speed range of the compressor. Since this was not possible, there was a case where the cooling capacity became insufficient due to gas shortages in the cooler.

Further, when the load is low, even if an attempt is made to reduce the flow rate of the refrigerant in order to reduce the power consumption, since the valve control flow rate is fixed, it can be controlled only within the rotational speed range of the compressor. However, the cooling capacity sometimes exceeded the minimum required flow rate, and the cooling capacity was too large.

If the optimum refrigerant flow rate is set at high load, the cooling capacity becomes too large at low load,
Conversely, if you set the optimum refrigerant flow rate at low load, you will run out of gas at high load, so in the conventional refrigeration cycle, the design is made in the middle of these two,
The optimum values of both flow rates were not satisfied at the same time.

As described above, in the conventional refrigeration cycle of the refrigerator / freezer, the refrigerant flow rate can be controlled only by the number of revolutions of the compressor, and it is a problem to construct a refrigeration cycle having an optimum flow rate for a fluctuating load. ing.

The present invention has been made in order to solve the above-mentioned problems, and is inexpensive and appropriately adjusts the refrigerant supply amount to each cooler in a wide range, so that the outside air load and the internal load are high. The objective is to provide the market with a refrigerator / freezer that secures cooling capacity against fluctuations and reduces power consumption.

[0019]

A control device for a refrigerator / freezer according to the present invention includes a freezer compartment cooler and a refrigerator compartment cooler, and a switching valve for distributing condensed refrigerant to the respective coolers. In the refrigerator-freezer having the above-mentioned, a three-way switching valve for distributing and controlling the flow rate of the refrigerant flowing through at least one of the plurality of coolers in a plurality of stages is provided.

Further, the control device for the refrigerator / freezer according to the present invention comprises a three-way switching valve for controlling the flow rate of the refrigerant flowing through at least one of the coolers in a plurality of stages, and by adjusting the opening degree of the three-way switching valve. , And controls the flow rate of the refrigerant flowing in each cooler.

Further, in the control device for a refrigerator-freezer according to the present invention, a plurality of capillaries are installed between at least one three-way switching valve and at least one cooler, and the refrigerant flow rate is controlled by selecting the capillaries. To do.

Further, the control device for the refrigerator / freezer according to the present invention opens the entrance of the three-way switching valve during defrosting.

Further, the control device for a refrigerator / freezer according to the present invention controls the switching valve for a certain period of time after defrosting, and allows the refrigerant to flow at the same time.

Further, the control device for a refrigerator / freezer according to the present invention comprises temperature detecting means for detecting temperatures at a plurality of points in the refrigerating cycle, and controls the opening degree of the three-way switching valve by the temperature difference of the temperature detecting means. It is a thing.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, the refrigerant circuit of the refrigeration cycle according to Embodiment 1 of the present invention will be described. 1 is a refrigerant circuit diagram of a refrigeration cycle according to Embodiment 1 of the present invention, FIG. 2 is a flow rate characteristic diagram of a three-way switching valve used in Embodiment 1, and FIG. 3 is three-way used in Embodiment 1. 5 is a vertical sectional view of the switching valve body, FIG. 4 is a plan view showing the valve seat of the three-way switching valve used in the first embodiment, and FIG.
FIG. 3 is a schematic view showing the relationship between the valve body and the surface in contact with the valve seat. Figure 6
FIG. 6 is an enlarged cross-sectional view of an essential part showing FIG. FIG. 7 (A),
(B), (C) and (D) are explanatory views showing the contact position of the valve element corresponding to the operation step of the three-way switching valve, and FIG. 8 is an opening table for each operation step of the three-way switching valve. FIG. 9 is a time chart for each operation step of the three-way switching valve. FIG. 10 is a flowchart showing the control of the three-way switching valve according to the first embodiment of the present invention.

In the figure, 1 is a compressor, 2 is a condenser, 3
Is a three-way switching valve whose opening can be controlled. The first outlet 3a whose outlet opening can be controlled is connected to the refrigerating chamber capillary 4a, and the other second outlet 3b is connected to the freezing chamber capillary 4b. There is. 5a is a refrigerator cooler, 5b is a freezer cooler,
6 is a check valve.

In the refrigerant circuit according to the first embodiment, as shown by the arrow, from the compressor 1 to the condenser 2 and through the three-way switching valve 3, one side is provided from the first outlet 3a to the refrigerating chamber capillary tube 4.
a, to the refrigerator 5 cooler 5a, and the other to the compressor 1 from the second outlet 3b through the freezer compartment capillary 4b and the freezer compartment cooler 5b.

FIG. 2 is a flow rate characteristic diagram of the three-way switching valve 3 used in the first embodiment, in which the vertical axis represents the flow rate at full opening of 1.
When the flow rate is set to 00%, the horizontal axis represents the operation step of the valve of the three-way switching valve 3. As shown in FIG. 2 (a), the first outlet 3 a of the three-way switching valve 3 is 0 depending on the number of pulses.
It has only two openings,% or 100%. Further, the second outlet 3b of the three-way switching valve 3 has an opening degree in the middle of the range of a certain number of pulses. The opening degree is determined according to the load, and is 70% in the first embodiment of the present invention. By using this three-way switching valve 3, the flow rate of the refrigerant flowing through the freezer compartment side capillary tube 4b can be controlled in three ways: 100% flowing, 70% flowing, and 0% (no flow).

Further, the three-way switching valve 3 adopts a system of rotating the valve body, and the flow rate can be controlled even in the case where the flow rate of the refrigerant is relatively small such as in a refrigerator.

The details of the three-way switching valve will be described with reference to FIGS. 3 to 9. In the figure, 3a is the first outlet of the three-way switching valve 3, 3b is the second outlet, and 3c is the inlet, all of which are provided on the valve seat 3d. 3e is the first outlet 3a,
An outlet side refrigerant pipe connected to the second outlet 3b, 3f is an inlet side refrigerant pipe connected to the inlet 3c, 3g is a coil, 3h is a resin rotor driven by this coil,
It is fixed to the main body by the shaft 3i. 3j is a stopper rubber for restricting rotation of the resin rotor 3i, 3k
Is a valve body, and a valve groove 3l is provided at a circumferential position of the second outlet 3b provided on the valve seat 3d. As shown in FIGS. 5 and 6, this valve groove has a groove inlet portion width A along the circumferential direction of the groove.
Is formed so that the groove length L and the groove entrance depth B are reduced by the groove length L.

With the valve body 3k thus constructed,
The valve groove 3l is located on the circumference of the second outlet 3b of the valve seat 3d,
By covering the second outlet 3b with the valve groove 3l, the flow path can be closed, and the opening can be controlled to adjust the flow rate.

Further, in FIG. 3, the opening of only one of the outlets can be controlled, but the opening of both outlets can be controlled by stacking two valve bodies.

The control signal is determined by various conditions such as the outside air temperature, the thermistors in each room, and the presence / absence of door opening / closing. For example, when the outside air temperature is high, when the load inside the refrigerator is large, or when the doors are frequently opened and closed, the cooling capacity is secured by setting the opening of the three-way switching valve 3 to 100%, and when the outside air temperature is low or the refrigerator is closed. When the internal load is small, the opening degree of the three-way switching valve 3 can be set to 70% to prevent overcooling and improve energy efficiency when the door is not opened or closed and the load is low.

The opening adjustments on the first outlet 3a and second outlet 3b sides of the three-way switching valve of the first embodiment will be described with reference to FIGS. 7, 8 and 9. 7 (A), (B),
In (C) and (D), the valve element 3k for each operation step has the valve seat 3d.
Showing a state of contact with, as shown in FIG. 8 and FIG.
In the operation step (A), the number of pulses is, and the valve opening / closing state is such that the first outlet 3a of the three-way switching valve is open and the second outlet 3b is closed. In the operation step (B), the number of pulses is and the valve open / close state is the first outlet 3a and the second outlet 3b of the three-way switching valve.
Both are closed. In the operation step (C), the number of pulses is, and the valve opening / closing state is such that the first outlet 3a of the three-way switching valve is closed and the second outlet 3b is 70% open. In the operation step (D), the number of pulses is and the valve opening / closing state is the first of the three-way switching valve.
The outlet 3a is closed and the second outlet 3b is open.

Next, a control flow chart for adjusting the opening degree of the three-way switching valve on the second outlet 3b side shown in FIG. 10 will be described. Starting, is the compressor running in step S11? To judge. As a result, if NO, the process proceeds to step S12. And is defrosting in step S12? Is judged, YE
If it is S, the process proceeds to step S13, and the opening degrees of the first outlet 3a and the second outlet 3b of the three-way switching valve 3 are both fully opened to 100%. Also, is defrosting in step S12? If the determination result is NO, the process proceeds to step S14, and the opening degrees of the first outlet 3a and the second outlet 3b of the three-way switching valve 3 are both fully closed by 0%.

During the operation of the compressor in step S11? If the result of the determination is YES, then step S15
Then, the outside air temperature Tout is measured by the thermistor attached outside the refrigerator. Then, the result measured in step S16 is determined. If Tout ≦ 25 ° C., the process proceeds to step S17. If Tout ≦ 25 ° C., the process proceeds to step S18, and the second outlet 3b of the three-way switching valve 3 is opened. The degree is 100% fully open.

In step S17, the number N of opening / closing operations of the freezer compartment door per fixed time τ1 hour is detected. And
If 5 ≦ N is determined in step S19, and if NO, then in step S20, the temperature of the freezer compartment within a fixed time τ2 is increased to Tfup. If the result of the determination is YES, in step S21, the opening degree of the second outlet 3b of the three-way switching valve 3 is fully opened to 100%.

In step S20, the result of raising the freezing room temperature within a certain time τ2 to raise Tfup is judged in step S22. If 2 ° C. ≦ Tfup, the process proceeds to step S23, in which the three-way switching valve 3 The degree of opening of the second outlet 3b is 70%. If the result of determination in step S22 is 2 ° C. ≦ Tfup, the process proceeds to step S24,
The opening of the second outlet 3b of the three-way switching valve 3 is fully opened to 100%.

Further, in the first embodiment, only 70% between 0% and 100% is provided, but a finer setting is possible, and for example, as shown in FIG. 2B, for a specific pulse range. It is also possible to set a multistage opening degree, or to have an opening degree that linearly changes from 0% to 100% in the same pulse range as shown in FIG. 2 (c). By doing so, it becomes possible to perform finer temperature control of the freezer compartment than before.

Further, depending on the form of the refrigerator, the 3b side of the three-way switching valve whose opening can be controlled may be connected to the refrigerating room capillary tube 4a side. Furthermore, it is also possible to use a three-way switching valve that can control the opening on both sides.

By installing such a three-way switching valve 3, it becomes possible to secure the necessary cooling capacity without waste.

Embodiment 2. FIG. 11 shows a refrigerant circuit diagram of the refrigerator-freezer according to the second embodiment. In FIG. 11, the condenser 2
Equipped with a four-way switching valve 19 (1 inlet, 3 outlets),
The first outlet 19a is connected to the refrigerating compartment capillary 4a, and the second outlet 19b and the third outlet 19c are connected to the first freezing compartment capillary 4b and the second freezing compartment capillary 4c, respectively. The other configurations of the refrigerant circuit are the same as those of the conventional one.

FIG. 12 is a flow rate characteristic diagram of the four-way switching valve 19 according to the second embodiment, and the four-way switching valve 19 provided in this refrigerant circuit has only the function of switching the flow path. The vertical axis represents the flow rate ratio when the fully open flow rate is 100%, and the horizontal axis represents the operation step of the four-way switching valve 19.

Further, the diameters of the first freezer compartment capillaries 4b and the second freezer compartment capillaries 4c are different from each other. For example, the first freezer compartment capillaries 4b have a diameter larger than that of the second freezer compartment capillaries 4c. ing. At this time, the flow rate of the refrigerant flowing through the freezer compartment cooler 5b differs depending on whether the refrigerant flows through the second freezer compartment capillary tube 4b or the second freezer compartment capillary tube 4c.
The flow rate in the first freezer compartment capillary tube 4b is greater than that in the second freezer compartment capillary tube 4c. When the load is high, the refrigerant flows through the first freezer compartment capillaries 4b to ensure sufficient cooling capacity in cooperation with the internal fan and the compressor, and when the load is low, the refrigerant flows through the second freezer compartment capillaries 4c. ,
The flow rate of the refrigerant flowing in the freezer compartment cooler 5b can be reduced to reduce the input and enhance energy saving.

By constructing such a cycle, it is possible to control the flow rate to the refrigerator for the freezer for each load.
It is possible in stages.

Of course, similar to the three-way switching valve used in the first embodiment, the flow rate can be further controlled by providing a multi-stage or linear opening for each function and operation step at each outlet. .

Embodiment 3. In the third embodiment, the three-way switching valve 3 or the four-way switching valve 19 is controlled before and after defrosting. The structure of the refrigeration cycle is the same as in the first and second embodiments.

Usually, the defrosting control is such that the defrosting heater installed below the cooler 5b heats the cooler 5 until the defrosting thermistor attached to the freezer compartment cooler 5b reaches a certain temperature. Therefore, the heating is from the outside of the tube. Here, it is possible to shorten the defrosting time by heating the inside of the pipe. By opening the inlet / outlet of the three-way switching valve 3 or the four-way switching valve 19 in order to warm it from the inside of the pipe, a refrigerant having a relatively high temperature flows into the cooler 5 from the compressor, so that the three-way switching valve 3 or the four-way switching valve 19 Defrosting time is shorter than when the door is closed.

When the defrosting time is shortened, the temperature change in the cold storage before and after the defrosting is small, the temperature rise in the cold storage during defrosting is suppressed, the influence on the food in the cold storage is small, and the power consumption is low. The amount can also be reduced.

Further, after defrosting, each cooler immediately after defrosting is heated to about + 15 ° C. due to heating by the heater. Therefore, in the control for alternately cooling the refrigerating room or the freezing room, either room is cooled. The temperature of will rise until the next cooling.

In order to prevent such a situation, the three-way switching valve 3 or the four-way switching valve 19 is controlled so that the refrigerant flows to both coolers for a certain period of time immediately after defrosting. In order to prevent overcooling, for example, the flow rate to the freezer compartment cooler is suppressed to some extent (about 70%) and 100% to the refrigerating compartment cooler.
Flow control is also possible.

FIG. 13 shows time-series changes in the cooler temperature, the in-compartment temperature (freezer compartment temperature) and the opening of the switching valve when the above control is performed. At the cooler temperature and the freezer temperature in the figure, the alternate long and short dash line shows the case where the inlet / outlet port of the three-way switching valve 3 is closed, and the solid line shows the case where the inlet / outlet port of the three-way switching valve 3 is open. Comparing the two lines, the solid line rises quickly at the start of defrosting, the defrosting completion time is shortened (comparison between A and B), and the rise temperature C of the freezer compartment temperature at the completion of defrosting is also kept low. I understand.

Fourth Embodiment FIG. 14 is a conceptual diagram showing a power consumption amount and a cooler inlet / outlet temperature difference with respect to a refrigerant flow rate flowing in the freezer compartment cooler according to the fourth embodiment. In the figure, the solid line shows the power consumption and the broken line shows the temperature difference between the inlet and outlet of the cooler. It can be seen from FIG. 14 that there is a point where the power consumption becomes minimum for a certain refrigerant flow rate.

The temperature difference between the inlet and outlet of the cooler with respect to the flow rate of the refrigerant changes as shown in FIG. 14. Therefore, the flow rate of the refrigerant flowing through the cooler is detected by detecting this temperature difference and controlling the three-way switching valve 3 and switching the capillaries. It is possible to always operate in a state where the power consumption is low by adjusting the.

In the fourth embodiment, the temperatures of a plurality of points in the refrigerant circuit are detected by a thermistor, and the opening of the three-way switching valve 3 is controlled or the capillaries are switched by the temperature difference. The structure of the refrigerant circuit is the same as in the first and second embodiments.

In the fourth embodiment, temperature detecting thermistors are attached to the inlet and outlet of the cooler. The outlet can also be replaced by a defrost thermistor which is usually attached to the header.

FIG. 15 is a control flowchart according to the fourth embodiment. By performing this control, the temperature difference between the inlet and outlet of the cooler can be kept within a certain range and a stable flow rate can be sent to the cooler, so that the power consumption can be suppressed. In FIG. 15, after starting and determining whether or not the compressor is operating in step S21, the timer count is started in step S22. After starting the timer count, the process proceeds to step S23, where the timer is τ? Count until minutes, YE
If it is S, the process proceeds to step S24, where the temperature difference t between the inlet and outlet of the cooler
_{When ie} is detected and a is not within a certain range and a is not a ≦ t _ie <b, and t _ie <a, the process proceeds to step 25, and the flow rate is decreased by reducing the opening degree of the three-way switching valve 3 or switching to a capillary tube. Control. Further, in step S24, the cooler inlet / outlet temperature difference t _ie is detected, and if b ≦ t _ie , step 2
In step 6, the control is performed by increasing the opening degree of the three-way switching valve 3 or switching to the thick capillary to reduce the flow rate.

Further, in step S24, the cooler inlet / outlet temperature difference t _ie is detected, and if a ≦ t _ie <b, the counter is reset in step S27, the process returns to the start, and every τ minutes until the compressor is stopped. This control is repeated. By performing such control, it is possible to perform lean operation without deviating from the point where the power consumption becomes the smallest.

As a concrete example value of the time constant τ, 1 to 3
Minutes, the temperature difference t between the inlet and outlet of the cooler _ieAs a: 1,
b: About 7 is desirable.

Fifth Embodiment In the fifth embodiment, the temperature of the outside air, the temperature inside the refrigerator, and the temperature at the inlet / outlet of the cooler are detected by a thermistor, and the compressor rotation speed and the opening of the switching valve are controlled or the capillaries are switched.

The content of control is the same as that of the fourth embodiment, but at the time of start-up, high load, and after defrosting, the cooler inlet / outlet temperature difference t _ie is above a certain range ( _b≤tie ). May continue. In such a case, the compressor rotation speed is changed (accelerated) from the outside air temperature and the inside temperature to control the opening of the switching valve or switch the capillaries.

Conventionally, the cooling capacity was increased only by increasing the rotational speed of the compressor.
By this, the opening degree of the switching valve 3 can be controlled or the capillaries can be switched before increasing the rotation speed of the compressor, and the flow rate flowing to the cooler can be increased. Can be achieved. The fifth embodiment is more economical than the fifth embodiment because the power consumption is smaller than that of increasing the rotation speed of the compressor.

Further, by increasing the fan rotation speed in the same manner, it is possible to perform finer control.

FIG. 16 is a time chart showing a time series movement of each element of the fifth embodiment. In FIG. 16, for example, the rotation speed of the compressor is set to the third speed (50, 55, 60 rps),
Switch valve opening in 3 levels (50, 75, 100%), fan speed in 3rd speed (1200, 1250, 1300 rp)
m) It is a time series change in the case of having. By opening the opening of the switching valve before the number of revolutions of the compressor and the number of revolutions of the fan increase, the flow rate of the refrigerant flowing into the cooler can be controlled in stages and more finely than before, so that high load can be achieved. Even when the time goes by, the cooling capacity will not be exceeded and a lean operation will be realized.

[0065]

As described above, the control device of the refrigerator / freezer according to the present invention has the refrigerator for the freezer compartment and the refrigerator for the refrigerating compartment, and distributes the condensed refrigerant to the respective coolers. In a refrigerator-freezer having a switching valve to do so, since it is configured to include a three-way switching valve for controlling the flow rate of the refrigerant flowing through at least one of the plurality of coolers in a plurality of stages, at the time of high load and low load It is possible to obtain an optimum refrigerant flow rate for each and prevent insufficient cooling capacity and supercooling.

Further, the control device for the refrigerator / freezer according to the present invention is provided with a three-way switching valve for controlling the flow rate of the refrigerant flowing through at least one of the coolers in a plurality of stages, and by adjusting the opening degree of the three-way switching valve. Since the configuration is such that the flow rate of the refrigerant flowing through each cooler is controlled, it is possible to provide an inexpensive refrigerator that can cope with load fluctuations.

Further, in the control device for a refrigerator / freezer according to the present invention, a plurality of capillaries are installed between at least one three-way switching valve and at least one cooler, and the refrigerant flow rate is controlled by selecting the capillaries. With this configuration, it is possible to provide an inexpensive refrigerator that can cope with load fluctuations.

Further, since the control device for the refrigerator / freezer according to the present invention is constructed so as to open the inlet / outlet port of the three-way switching valve during defrosting, the defrosting time can be shortened and the temperature rise in the refrigerator can be suppressed. Become.

Further, since the control device for the refrigerator / freezer according to the present invention is configured such that the switching valve is controlled for a certain period of time after defrosting, and the refrigerant flows at the same time, it is possible to reduce the temperature change in the refrigerator before and after defrosting. it can.

Further, the control device for a refrigerator / freezer according to the present invention comprises temperature detecting means for detecting temperatures at a plurality of points in the refrigerating cycle, and controls the opening degree of the three-way switching valve by the temperature difference of the temperature detecting means. Since the configuration is adopted, it is possible to secure the cooling capacity at the time of high load or reduce the power consumption at the time of low load.

[Brief description of drawings]

FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle of a refrigerator-freezer according to Embodiment 1 of the present invention.

FIG. 2 is a flow rate characteristic diagram of the three-way switching valve according to the first embodiment of the present invention.

FIG. 3 is a vertical sectional view of a three-way switching valve body according to the first embodiment of the present invention.

FIG. 4 is a plan view showing a valve seat of the three-way switching valve according to the first embodiment of the present invention.

FIG. 5 is a schematic diagram showing the relationship between the valve body and the surface in contact with the valve seat according to the first embodiment of the present invention.

FIG. 6 is an enlarged cross-sectional view of a main part showing a cross-section of FIG. 5 of the present invention.

FIG. 7 is an explanatory diagram showing a contact surface position of the valve body with the valve seat corresponding to the operation step of the three-way switching valve used in the first embodiment of the present invention.

FIG. 8 is a flowchart showing control of the three-way switching valve according to the first embodiment of the present invention.

FIG. 9 is an opening table for each operation step of the three-way switching valve according to the first embodiment of the present invention.

FIG. 10 is a time chart for each operation step of the three-way switching valve according to the first embodiment of the present invention.

FIG. 11 is a refrigerant circuit diagram of a refrigeration cycle of a refrigerator-freezer according to Embodiment 2 of the present invention.

FIG. 12 is a characteristic diagram simply showing a flow rate characteristic of a switching valve according to a second embodiment of the present invention.

FIG. 13 is a time chart showing a movement showing a time-series change of a cooler temperature before and after defrosting, a freezing room temperature, and an opening degree of a switching valve according to a third embodiment of the present invention.

FIG. 14 is a conceptual diagram showing a power consumption amount and a cooler inlet / outlet temperature difference with respect to a refrigerant flow rate flowing in the cooler of the present invention.

FIG. 15 is a flow chart briefly showing control according to the fourth embodiment of the present invention.

FIG. 16 is a time chart diagram showing a time-series movement of each element of the fifth embodiment of the present invention.

FIG. 17 is a schematic cross-sectional view showing the structure of a conventional refrigerator-freezer.

FIG. 18 is a refrigerant circuit diagram of a refrigeration cycle in which a plurality of coolers of a conventional refrigerator-freezer are connected in parallel.

FIG. 19 is a refrigerant circuit diagram of a refrigeration cycle in which a plurality of coolers of a conventional refrigerator-freezer are connected in series.

FIG. 20 is a flowchart showing control of a switching valve in a conventional refrigerator-freezer.

FIG. 21 is a time chart diagram showing a time-series movement of each element of the conventional refrigerator.

FIG. 22 is an explanatory table showing the starting rotation speed of each element of the conventional refrigerator.

[Explanation of symbols]

1 compressor, 2 condenser, 3 three-way switching valve, 3a 1st
Outlet, 3b Second outlet, 3c Inlet, 3d Valve seat, 3h
Resin rotor, 3j stopper rubber, 3k valve body, 3l
Valve groove, 3n Valve contact surface, 4 Capillary tube, 5a Refrigerator cooler, 5b Freezer cooler, 6 Check valve, 11
Cold room.

Continued front page    (72) Inventor Mutsumi Kato             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 3L045 AA02 AA06 BA01 CA02 DA02                       EA01 HA02 JA15 LA12 LA14                       MA02 MA04 MA05 MA15 NA09                       NA15 NA22 PA01 PA02 PA03                       PA04 PA05

Claims (6)

[Claims] 1. A refrigerating refrigerator having a freezer compartment cooler and a refrigerator compartment cooler, and a switching valve for distributing condensed refrigerant to each of the coolers, wherein at least one of the plurality of coolers is provided. A control device for a refrigerator / freezer, comprising a three-way switching valve for controlling the flow rate of the refrigerant flowing through the cooler in multiple stages. 2. A three-way switching valve for distributing and controlling a refrigerant flow rate flowing to at least one of the coolers in a plurality of stages, and controlling the flow rate of the refrigerant flowing to each cooler by adjusting the opening degree of the three-way switching valve. The control device for the refrigerator / freezer according to claim 1, wherein 3. A plurality of capillaries are installed between at least one three-way switching valve and at least one cooler, and the refrigerant flow rate is controlled by selecting the capillaries. Item 2. A control device for a refrigerator / freezer according to item 2. 4. The control device for a refrigerator / freezer according to claim 1, wherein the inlet / outlet of the three-way switching valve is opened during defrosting. 5. The method according to claim 1, wherein the switching valve is controlled for a certain period of time after defrosting so that the refrigerant flows at the same time.
Alternatively, the control device for the refrigerator / freezer according to claim 3. 6. The method according to claim 1, further comprising a plurality of temperature detecting means for detecting temperatures at a plurality of points of the refrigeration cycle, wherein the opening of the three-way switching valve is controlled by the temperature difference of the temperature detecting means. The control device for the refrigerator / freezer according to claim 2 or 3.