JP2003214743A - Refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerator capable of holding down the quantity of refrigerant leakage even when a refrigerant leakage occurs in one of a plurality of condensers connected in parallel. <P>SOLUTION: A compressor 2, a first switching valve 3, a first condenser 4 and a second condenser 5 connected in parallel, a second change-over valve 6, a capillary tube 7 as a pressure reducer, and a cooling device 10 which is an evaporator and cools a refrigerating chamber 8 of a refrigerator 1 are connected to each other to be annular by piping. When a refrigerant leakage occurs in one condenser, the first and second change-over valves 3, 6 are switched, whereby a refrigerant circulation to one condenser is stopped to hold down the quantity of refrigerant leakage. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator used in homes and the like, and more particularly to a refrigerator provided with a refrigeration cycle using a flammable refrigerant of normal butane, isobutane, propane and a mixture thereof.

[0002]

2. Description of the Related Art Since a non-flammable refrigerant is used in a refrigeration cycle in a household refrigerator or the like, there is no possibility of burning even if the refrigerant leaks from the refrigeration cycle.

However, in recent years, there has been a worldwide demand for prevention of destruction of the ozone layer of the earth and prevention of global warming by a nonflammable refrigerant. Then, as a natural refrigerant that does not destroy the ozone layer and has a small warming effect, use of a flammable refrigerant of normal butane, isobutane, propane and a mixture thereof in a refrigerating cycle of a refrigerator has been studied.

[0004]

However, in the refrigeration cycle using the above-mentioned flammable refrigerant, there is a problem that the refrigerant may be ignited when refrigerant leaks in the condenser.

Further, when the refrigerant flowing to the condenser is stopped in order to reduce the refrigerant leakage from the condenser, the operation of the refrigeration cycle is stopped and the cooling operation is stopped, so that the operation of the refrigerator must be stopped. There was a problem that I could not get it.

[0006] Therefore, an object of the present invention is to provide a refrigerator in which the amount of refrigerant leakage from the condenser is minimized and cooling operation can be continued.

[0007]

Therefore, the invention according to claim 1 is, in a refrigerator having a storage chamber, a compressor, a switching valve, a plurality of condensers connected in parallel, and a refrigerant toward the condenser. And a decompression device, and a refrigerating circuit in which an evaporator for cooling the cold air circulating in the storage chamber is sequentially connected in an annular shape, and the refrigerating circuit is filled with a flammable refrigerant. .

According to a second aspect of the present invention, in a refrigerator having a storage chamber, a compressor, a first switching valve, a plurality of condensers connected in parallel, a second switching valve, a pressure reducing device, and the storage. A refrigerating circuit in which evaporators for cooling cold air circulating in the chamber are sequentially connected in an annular shape is provided, and the refrigerating circuit is filled with a combustible refrigerant.

According to a third aspect of the present invention, in a refrigerator provided with a storage chamber, a compressor, a first switching valve, a parallel circuit in which a plurality of series circuits of a condenser and a pressure reducing device are connected in parallel, and a second circuit. A refrigerating circuit in which a switching valve and an evaporator for cooling the cold air circulating in the storage chamber are sequentially connected in an annular shape is provided, and the refrigerating circuit is filled with a combustible refrigerant.

According to a fourth aspect of the present invention, there is provided a refrigerator including a refrigerating chamber and a freezing chamber, wherein a compressor, a first switching valve,
A parallel circuit of a condenser, a second switching valve, a pressure reducing device, and a series circuit of the evaporator for the refrigerating chamber and a parallel circuit of a pressure reducing device and a series circuit of the evaporator for the freezing chamber, which are connected in parallel, are sequentially connected in an annular shape. It is characterized in that a refrigerating circuit is formed, and the refrigerating circuit is filled with a flammable refrigerant.

According to a fifth aspect of the present invention, in the refrigerator according to the first to fourth aspects, a refrigerant flow rate control valve is provided on the refrigerant outlet side of the cooler, and the opening of the refrigerant flow rate control valve is set in the refrigerator. It is characterized by comprising a control device for controlling according to the temperature detected by the detection means for detecting the temperature.

According to a sixth aspect of the present invention, in the refrigerator according to the second to fourth aspects, a plurality of inlet side temperature detectors for detecting the temperature of the refrigerant inlet side of each condenser, and an outlet of the second switching valve. Side temperature detector for detecting the refrigerant temperature on the side, the temperature detected by each of the inlet side temperature detectors and the temperature detected by the outlet side temperature detectors are compared, and the first switching valve is based on the temperature difference. And a control device for switching the second switching valve.

According to a seventh aspect of the present invention, in the refrigerator according to the first to fourth aspects, a refrigerant gas detector is provided near each condenser, and the gas detector detects the refrigerant gas leaked from each condenser. In this case, a control device for switching the first switching valve and the second switching valve is provided.

The invention according to claim 8 is the refrigerator according to any one of claims 1 to 4, wherein the first switching valve and the second switching valve are arranged so that the refrigerant flows through a plurality of condensers during pull-down operation. It is characterized in that a switching control device is provided.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a refrigeration cycle diagram of a refrigerator 1 according to the present invention, which includes a compressor 2, a first switching valve 3, a first condenser 4 and a second condenser 5 connected in parallel, and a second switching valve. 6, a cooler 1 for cooling the refrigerating chamber 8 of the refrigerator 1 which is a capillary tube 7 as a pressure reducing device and an evaporator
0 is connected by a pipe in a ring shape, and a flammable refrigerant of normal butane, isobutane, propane and a mixture thereof is filled to form a refrigeration cycle.

Reference numeral 11 is a control device including a microcomputer for controlling the operation of the refrigerator 1;
Reference numerals 13 are first and second gas detectors that are provided near the first condenser 4 and the second condenser 5, respectively, and detect the leaked refrigerant gas and output a signal. Reference numeral 15 is a temperature detector provided in the refrigerator compartment 8. The controller 11 is a ROM (not shown) that is a storage element that stores a program for controlling the operation of the compressor 2 and a RAM that is a storage element that stores data such as the refrigerator compartment temperature of the refrigerator at any time. (Not shown) and a program stored in the ROM based on data such as the temperature detected by the temperature detector 15 stored in the RAM, the operation of the compressor 2, the operation of the first switching valve 3 and the second switching valve 6 The CPU is a central processing unit that controls switching.

In the above refrigeration cycle, the first switching valve 3 is normally used when the power of the refrigerator is turned on, that is, when the refrigerator is pulled down.
The control device 11 outputs a signal to each switching valve so that the refrigerant flows through both the first and second condensers 4 and 5. Therefore, the condensing capacity of the refrigerant can be maximized and the pull-down time can be shortened.

By operating the compressor 2, the refrigerant is refrigerated in a refrigeration cycle, that is, from the compressor 2 to the first switching valve 3, the first and second condensers 4 and 5, the second switching valve 6, and the capillaries. It circulates through the tube 7 and the cooler 10, and the cooler 10 cools the inside of the refrigerating chamber 8. Then, when the cooling load of the refrigerating chamber 8 decreases and the cold air temperature gradually decreases to the set temperature, the control device 11 outputs a switching signal to the first and second switching valves 3 and 6, and the first and second switching valves 3 and 6 are output. A timer is provided in, for example, the control device 11 in the second condensers 4 and 5, and the refrigerant flows alternately every predetermined time. Further, the control device 11 outputs an ON / OFF signal of the compressor 2 based on the set temperature, the operation of the compressor 2 is controlled, and the refrigerating chamber is maintained at substantially the set temperature.

When a refrigerant leak occurs in the first condenser 4 or the second condenser 5, the first gas detector 12 or the second gas detector 13 detects the leaked refrigerant gas. Then, the control device 11 controls the first switching valve 3 and the second switching valve so that the refrigerant circulation to one of the condensers in which the refrigerant has leaked is stopped and the refrigerant flows to the condenser in which the refrigerant has not leaked. A switching signal is output to 6 and each switching valve will not switch to the leaked condenser side thereafter. Therefore, the refrigerant leakage from the condenser in which the refrigerant leakage has occurred can be suppressed to the amount of the refrigerant flowing in the condenser when the switching valve is switched as described above, and the refrigerant leakage amount can be minimized. It will be possible. Further, the refrigeration cycle can be operated by continuously using the condenser in which the refrigerant does not leak, and as a result, the inside of the refrigerating chamber 8 can be continuously cooled by the cooler 10.

In the above embodiment, the second switching valve 6 is provided so that the switching can be performed simultaneously with the switching of the first switching valve 3. However, as shown by the broken line in FIG.
And a non-return valve that allows the refrigerant to flow from the condensers toward the capillary tubes 7 on the outlet side of the second condensers 4 and 5 and blocks the refrigerant from the capillary tubes 7 to the condensers. When the valves 14 and 14 are provided, it is not necessary to connect the second switching valve 6, and the switching of the valves can be simplified.

Next, a second embodiment of the present invention will be described based on the refrigeration cycle diagram shown in FIG. In FIG. 2, the same components as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The refrigeration cycle comprises a compressor 2, a first switching valve 3, a first condenser 4 and a first capillary tube 16 connected in parallel, a second condenser 5 and a second capillary tube 17. The parallel circuit, the second switching valve 6 and the cooler 10 are connected to each other in an annular pipe, and a flammable refrigerant of normal butane, isobutane, propane and a mixture thereof is filled.

Further, the control unit 11 controls the operation of the compressor 2 and the switching of the first and second switching valves 3 and 6, and the first and second switching valves are operated during pull-down as in the first embodiment. The refrigerant flows through the condensers 4 and 5. After that, when the cooling load decreases, the first switching valve 3 or the second switching valve 6 is switched, and the first and second condensers 4 and 6 are switched,
In the first condenser 4 or the second condenser 5, for example, a timer is provided in the control device 11 so that the refrigerant flows alternately every predetermined time. As described above, when switching the condenser, first, the operation of the compressor 2 is stopped, and the first and second switching valves 3 and 6 are switched after the pressure on the high-pressure side decreases after a predetermined time has elapsed.

Furthermore, when a refrigerant leak occurs in the first condenser 4 or the second condenser 5, the gas detector 12
Alternatively, the gas detector 13 detects the leaked gas. Then, the control device 11 operates to output a switching signal to the first control valve 3 and the second control valve 6, and the first control valve 3 and the second control valve 6 are output.
The control valve 6 is not switched to the leaked condenser side. As a result, the refrigerant does not flow to the leaking condenser side, and the amount of refrigerant leakage is suppressed to the amount of refrigerant circulating in the leaking condenser and the capillary tube connected to this condenser, and the leakage amount. Can be kept as low as possible.

Even after the refrigerant has stopped flowing into one of the first and second condensers 4 and 5 as described above, the refrigerant flows into the other condenser to continue the refrigeration cycle. You can drive.

In the second embodiment, too,
Although the second switching valve 6 is provided so as to be switched at the same time as the switching of the first switching valve 3, the check valves 14, 14 are shown as shown by the broken line in FIG. 2 as in the first embodiment. In the case where the switch is provided, it is not necessary to connect the second switching valve 6, and the switching of the valve can be simplified.

The third embodiment of the present invention will be described below with reference to the refrigerating cycle diagram of the refrigerator / freezer 50 shown in FIG. In FIG. 3, the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

The refrigeration cycle includes a compressor 2, a first switching valve 3, a parallel circuit of a first condenser 4 and a second condenser 5 connected in parallel, a four-way valve 20 as a switching valve, and a first switching valve. A parallel circuit of the condenser 16 and the cooler 22 on the refrigerating compartment 21 side (hereinafter referred to as refrigerating compartment cooler) 22 and the second capillary tube 17 and the cooler on the freezing compartment 23 side (hereinafter referred to as refrigerating compartment cooler) 24 It is formed by connecting a pipe in an annular shape, connecting a flow rate control valve 25 to the outlet side of the refrigerator compartment cooler 22, and filling a combustible refrigerant of normal butane, isobutane, propane and a mixture thereof.

The controller 11 controls the operation of the compressor 2 and the switching of the first switching valve 3 and the four-way valve 20, and the four-way valve 20 is as shown by solid arrows 30, 31 or broken arrows 32, 33. It is possible for the refrigerant to flow. Then, during pull-down and during normal operation, the four-way valve 20 is switched as shown by the solid arrow 30 and the broken arrow 32 shown in FIG. 3, and the refrigerant flows into the first and second condensers 4 and 5. .

Further, the control unit 11 operates based on the refrigerating compartment temperature and the set temperature detected by the refrigerating compartment side temperature detector 15, and outputs the opening signal of the flow control valve 25. As a result,
The flow rate of the refrigerant flowing through the refrigerator compartment cooler 22 is controlled, and the refrigerator compartment temperature is maintained at a substantially set temperature. Further, the control device 11 operates based on the freezer compartment temperature and the set temperature detected by the freezer compartment temperature detector 35, and controls whether or not the refrigerant flows in the direction of the broken arrow 32 of the four-way valve 20. As a result, whether or not the refrigerant flows in the freezer compartment cooler 24 is controlled, and the freezer compartment temperature is maintained at a substantially set temperature.

When the refrigerator / refrigerator is operating as described above, for example, when a refrigerant leak occurs in the first condenser 4, the first gas detector 12 detects the leaked refrigerant gas and the control device 11 works. Then, from the control device 11 to the first
A valve switching signal is output to the switching valve 3 and the four-way valve 20 of
The first switching valve 3 switches so that the refrigerant flows only to the second condenser 5, and the four-way valve 20 switches so that the refrigerant flows only in the directions indicated by broken line arrows 32 and 33. Therefore, the refrigerant does not flow into the first condenser 4, and the leakage of the refrigerant circulates to the first condenser 4 until just before the switching of the first switching valve 3 and the four-way valve 20 as described above. Since the amount of the refrigerant is suppressed, the amount of refrigerant leakage can be suppressed as small as possible.

The refrigerant is continuously circulated to the refrigerator compartment cooler 22 and the freezer compartment cooler 24 via the second condenser 5, the four-way valve, the first capillary tube 16 and the second capillary tube 17. Therefore, the refrigerating chamber 21 and the freezing chamber 23 can be cooled even after the refrigerant leakage occurs.

When a refrigerant leak occurs in the second condenser 5, the second detector 13 detects the leaked refrigerant gas and the controller 11 operates. Then, a valve switching signal is output from the control device 11 to the first switching valve 3 and the four-way valve 20, the first switching valve 3 switches so that the refrigerant flows only to the first condenser 4, and the four-way valve. 20 is a practice arrow 30, 31
The refrigerant is switched to flow only in the direction indicated by.
Therefore, the refrigerant does not flow into the second condenser 5, and the leakage of the refrigerant is suppressed to the amount of the refrigerant circulated in the second condenser 5, so that the refrigerant leak occurs in the first condenser 4. As in the case of the above, the amount of refrigerant leakage can be suppressed to a minimum.

At this time, the refrigerant continues to the refrigerator compartment cooler 22 and the freezer compartment cooler 24 through the first condenser 4, the four-way valve, the first capillary tube 16 and the second capillary tube 17. Therefore, the refrigerating chamber 21 and the freezing chamber 23 can be cooled even after the refrigerant leakage occurs, as in the case where the refrigerant leakage occurs in the first condenser 4.

In each of the above embodiments, the first
Although the refrigerant leakage from the condenser 4 or the second condenser 5 of the above is detected by the first and second gas detectors 12 and 13, the refrigerant inlet side and the refrigerant of the condensers connected in parallel Each temperature detector on the outlet side is provided, and the difference between the detected refrigerant inlet side temperature and the refrigerant outlet side temperature is compared with a preset normal temperature difference, and as a result of comparison, the detected refrigerant inlet side temperature and refrigerant are detected. When the difference between the outlet side temperature and the preset normal temperature difference are different, the control device determines that refrigerant leakage has occurred. Then, by stopping the operation of the compressor 2 and stopping the circulation of the refrigerant to the condensers 4 and 5 in which it is determined that the refrigerant leakage has occurred, the amount of refrigerant leakage can be minimized.

This will be described in detail. For example, as shown by the broken line in FIG. 1, the first and second condenser inlet temperature detectors are provided on the refrigerant inlet sides of the first and second condensers 4 and 5, respectively. 41, 4
2 is provided, and a condenser outlet temperature detector 43 is provided on the outlet side of the second switching valve 6. Then, the controller 11 compares the difference between the detected temperatures of the first and second condenser inlet temperature detectors 41 and 42 and the detected temperature of the condenser outlet temperature detector 43 with a preset normal temperature difference. .

Then, a refrigerant leak occurs in one of the first and second condensers 4 and 5, and the difference between the detected condenser inlet side temperature and outlet side temperature is usually set. If the temperature difference is different from the above temperature difference, the control device 11 determines that the refrigerant leakage has occurred in one of the condensers. The control device 11 thus determined stops the compressor 2 and also stops the refrigerant circulation to one of the condensers so that the refrigerant flows only to the other normal condenser. Switch between 3 and 6. That is, the first and second switching valves are configured to close the refrigerant circuit of the condenser on the side where the detected temperature difference is different from the set temperature difference and to open the refrigerant circuit of the condenser on the side of the normal temperature difference. Switch between 3 and 6.

Further, while the refrigerant flows through the first and second condensers during pull-down, when the cooling load thereafter decreases, the control device 11 causes the control device 11 to perform the first operation every predetermined time counted by the timer provided in the control device 11. By switching the first and second switching valves to prevent the refrigerant from accumulating in the first and second condensers, the amount of refrigerant leakage can be suppressed and minimized.

Although the embodiments of the present invention have been described above, various alternatives, modifications, and variations can be made by those skilled in the art based on the above description, and the present invention can be carried out in various ways as described above without departing from the spirit of the invention. It is intended to cover alternatives, modifications or variations.

[0040]

As described above, according to the present invention,
Even when a refrigerant leak occurs in any one of the plurality of condensers connected in parallel, the amount of refrigerant leak can be suppressed to a minimum.

Further, the refrigerating cycle can be continuously operated by flowing the refrigerant into the condenser in which the refrigerant does not leak.

[Brief description of drawings]

FIG. 1 is a refrigeration cycle diagram of a first embodiment of a refrigerator.

FIG. 2 is a refrigeration cycle diagram of the second embodiment of the refrigerator.

FIG. 3 is a refrigeration cycle diagram of a third embodiment of a refrigerator.

[Explanation of symbols]

1 refrigerator 2 compressor 3 First switching valve 4 First condenser 5 Second condenser 6 Second switching valve 7, 16, 17 Capillary tube 8 Refrigerator 10 Cooler 11 Control device 12 First gas detector 13 Second gas detector 14 Check valve 15, 35 Temperature detector 20 four-way valve 25 Flow control valve

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25D 29/00 F25D 29/00 Z

Claims (8)

[Claims] 1. In a refrigerator having a storage chamber, a compressor, a switching valve, a plurality of condensers connected in parallel, a means for blocking the flow of a refrigerant toward the condenser, a decompression device, and the storage chamber. A refrigerator comprising a refrigeration circuit in which evaporators for cooling the circulating cold air are sequentially connected in an annular shape, and the refrigeration circuit is filled with a flammable refrigerant. 2. In a refrigerator having a storage chamber, a compressor, a first switching valve, a plurality of condensers connected in parallel, a second switching valve, a pressure reducing device, and cool air circulating in the storage chamber are cooled. A refrigerator comprising a refrigerating circuit in which evaporators are sequentially connected in an annular shape, and the refrigerating circuit is filled with a combustible refrigerant. 3. A refrigerator having a storage chamber, comprising: a compressor, a first switching valve, a parallel circuit in which a plurality of series circuits of a condenser and a pressure reducing device are connected in parallel, a second switching valve, and the storage chamber. A refrigerator comprising a refrigeration circuit in which evaporators for cooling the circulating cold air are sequentially connected in an annular shape, and the refrigeration circuit is filled with a flammable refrigerant. 4. A refrigerator having a refrigerator compartment and a freezer compartment, wherein a compressor, a first switching valve, a condenser connected in parallel,
A second switching valve, a pressure reducing device and a refrigerating circuit in which a parallel circuit of a series circuit of the evaporator for the refrigerating compartment and a series circuit of the pressure reducing device and the evaporator for the freezing compartment are sequentially connected in an annular shape, A refrigerator characterized in that the refrigeration circuit is filled with a flammable refrigerant. 5. A control device, wherein a refrigerant flow rate control valve is provided on the refrigerant outlet side of the cooler, and the opening degree of the refrigerant flow rate control valve is controlled according to the temperature detected by a detection means for detecting the temperature inside the refrigerator. The refrigerator according to claim 1, further comprising: a refrigerator. 6. A plurality of inlet side temperature detectors for detecting a temperature of a refrigerant inlet side of each condenser, an outlet side temperature detector for detecting a refrigerant temperature of an outlet side of the second switching valve, and each of the inlets. And a control device for comparing the detected temperature of the side temperature detector and the detected temperature of the outlet side temperature detector, and switching the first switching valve and the second switching valve based on the temperature difference. The refrigerator according to any one of claims 2 to 4. 7. A refrigerant gas detector is provided in the vicinity of each condenser, and when the gas detector detects a refrigerant gas leaked from each condenser, the first switching valve and the second switching valve. The refrigerator according to any one of claims 1 to 4, further comprising a control device for switching between the two. 8. The control device for switching the first switching valve and the second switching valve so that the refrigerant flows through the plurality of condensers during the pull-down operation. Refrigerator according to any one of.