JP2003269827A - Freezer-refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a refrigerant from reaching combustible concentration by positively recovering the refrigerant to minimize a leakage into a freezer- refrigerator. <P>SOLUTION: This freezer-refrigerator is provided with a refrigerating cycle in which the combustible refrigerant discharged from a compressor 17 passes through a condenser 11, a throttle apparatus 21 and an evaporator 25 and returns again to the compressor 17. When a liquid leakage is detected by liquid leakage means S3, S4, a first on-off valve c is put in closing operation, and a second on-off valve d is put in opening operation to positively recover the refrigerant from the compressor 17 by a refrigerant recovery means 47 while minimizing a leakage into the freezer-refrigerator. <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 freezer-refrigerator using a refrigerant that does not adversely affect the global environment.

[0002]

2. Description of the Related Art At present, as a refrigerant for a freezer-refrigerator, a CFC refrigerant is used because of its stable physical properties and easy handling.

[0003]

Although CFC-based refrigerants have stable physical properties and are easy to handle, they are said to destroy the ozone layer and adversely affect the global environment. Becomes

Among CFC-based refrigerants, HFC refrigerants do not destroy the ozone layer at all, but have the property of promoting global warming. In particular, in Europe where concern over environmental issues is high, this refrigerant is also prohibited. There is movement. That is, the artificially produced CFC refrigerant may be prohibited and a conventional natural refrigerant such as hydrocarbon may be used.

Therefore, the present invention provides a freezer-refrigerator that uses a flammable refrigerant that does not adversely affect the global environment as an alternative refrigerant and that does not cause an explosion even if it leaks and that ensures safety. Is intended.

[0006]

To achieve the above object, the present invention relates to a refrigeration cycle in which a refrigerant discharged from a compressor passes through a condenser, a throttle device and an evaporator, and returns to the compressor again. Refrigerant recovery means connected in parallel to the condenser on the discharge side of the compressor, and disconnecting the refrigerant flow to the condenser
A first on-off valve in contact with the second recovery valve, a second on-off valve disconnecting / contacting the flow of the refrigerant to the refrigerant recovery means, and a refrigerant leakage detection means for detecting a refrigerant leak, and a flammable refrigerant is used as the refrigerant, When the refrigerant leakage means detects the refrigerant leakage, the first opening / closing valve is closed and the second opening / closing valve is opened to collect the refrigerant from the compressor to the refrigerant recovery means. To do.

In a preferred embodiment, the refrigerant recovery means is covered with a heat insulating material and is housed in a cooling tank in which a refrigerant liquid is sealed.

Alternatively, a capillary tube having a third opening / closing valve openable to the atmosphere is provided on the outer circumference of the refrigerant recovery means.

Further, after the refrigerant from the compressor is recovered by the refrigerant recovery means, the third opening / closing valve is opened, and then the discharge pressure of the compressor detected by the discharge pressure detecting means provided in the compressor is The second on-off valve is closed and the compressor is stopped when the value becomes equal to or less than a predetermined set value.

[0010]

According to such a refrigerator-freezer, the refrigerant discharged from the compressor constitutes a refrigeration cycle in which the refrigerant passes through the condenser, the expansion device, and the evaporator, and returns to the compressor. During this refrigeration cycle, in the evaporator, the latent heat of evaporation is taken from the surrounding air through the fins to cool the air into cold air, and the cold air is sent to the inside by the air blower for cooling the inside to cool the inside.

When the refrigerant leaks during this refrigeration cycle operation, the refrigerant leak detection means detects it and, for example, the first
By opening the open / close valve and opening the second open / close valve, the refrigerant from the compressor is recovered by the refrigerant recovery means, so that the amount of refrigerant leakage can be suppressed to a low level and the explosive concentration can be reached. You will definitely be able to prevent it.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings of FIGS.

In FIG. 2, reference numeral 1 denotes a refrigerator main body of a freezer-refrigerator 3, and a front surface thereof has a plurality of opening / closing doors 5 for a freezing room, a refrigerating room and the like.

The lower part of the refrigerator body 1 is a partition room 7 and a machine room 9 of the refrigeration cycle as shown in FIG.

An accumulator 19 and an expansion device 21 (capillary tube) are arranged outside the condenser 11, the evaporation tray 13, the heat radiating blower 15 and the compressor 17 on the machine room 9 side. The accumulator 19 and the diaphragm device 21 are
It has a layout structure in which a pipe connection portion surrounded by an independent chamber 23 and in which refrigerant leakage is most likely to occur is arranged outside the partition chamber 7.

An evaporator 25, an internal cooling fan 27, a cool air outlet 29, and an internal air return port 31 are arranged on the partition chamber 7 side. The cold air outlet 29 and the in-compartment air return port 31 are connected to the in-compartment cold air circulation duct 33 on the refrigerator body 1 side, and communicate with the inside of the refrigerator 35 via the in-compartment cold air circulation duct 33.

FIG. 3 shows a refrigeration cycle in which a flammable refrigerant such as propane or isobutane is used as the refrigerant. That is, the refrigerant discharged from the compressor 17 passes through the condenser 11, the expansion device 21, the evaporator 25, and then returns to the compressor 17 to repeat the refrigeration cycle.
The latent heat of evaporation is taken from the surrounding air through the fins to cool the air to form cold air, and the cooling air is sent out from the cold air outlet 29 by the inside cooling fan 27.

The respective motors M1 and M2 of the compressor 17 and the fan 15 for radiating heat have a compressor drive circuit M1-1 as shown in FIG.
And the blower drive circuit M2-2 are turned on / off.

A contact point R-1 of the compressor drive circuit M1-1,
The contact R-2 of the blower drive circuit M2-2 is opened and closed by the control unit 33 described later. In FIG. 4, S-1 indicates a thermoswitch that opens the contact R-1 of the compressor drive circuit M1-1 separately from the signal from the control unit 34.

The control section 34 is a motor abnormality detecting sensor S which is an abnormality detecting means for detecting an abnormality in each of the motors M1 and M2.
1, S2 and the detection signals from the flammable refrigerant detection sensors S3, S4 serving as refrigerant leakage detection means are subjected to arithmetic processing and a command signal is output.

As the abnormality detection for detecting the abnormality of each motor M1, M2, the abnormality due to the insulation resistance value of the motor power supply, the abnormality due to the rotation speed of the motor, and the abnormality due to the winding temperature are detected. There are cases. The abnormality detection of each of the motors M1 and M2 is detected by the compressor motor abnormality detection sensor S1 or the blower motor abnormality detection sensor S2 provided in each of the motors M1 and M2 serving as abnormality detection means, and the detection signal is sent to the control unit 34. Is entered. As a result, the control unit 34 causes the contact point R of the compressor drive circuit M1-1.
-1 or the contact R2 of the blower drive circuit M2-2 is opened.

On the other hand, on the downstream side of the passing air passing through the condenser 11 or on the downstream side of the passing air passing through the evaporator 25, the flammable refrigerant detecting sensor S serving as the above-mentioned refrigerant leak detecting means.
3 and S4 are provided respectively.

The combustible refrigerant detection sensors S3 and S4 are arranged at the positions other than the above, in the vicinity of a pipe connecting portion such as an accumulator 19 serving as a high pressure side refrigerant passage, and the compressor 17.
Downstream S5 of the passing air passing through the air, near the cold air outlet 29 S
There is 6 mag.

The flammable refrigerant detection sensors S3 and S4 detect oxygen leakage, and at the same time, oxygen in the refrigerant flowing in the refrigeration cycle, that is, oxygen that enters the refrigeration cycle when the refrigerant leaks. The detection signal may be input to the control unit 34.

The control unit 34 contacts R-1 of the compressor drive circuit M1-1 based on the detection signals input from the combustible refrigerant detection sensors S3 and S4 during the refrigeration cycle operation.
3 is opened and the contact R-2 of the blower drive circuit M2-2 is closed, an alarm device 37, which is separately provided, is turned on and the inside cooling fan 27 is stopped, while FIG. As shown, it functions to close the opening / closing valves a and b, which are refrigerant circuit cutoff means provided between the expansion device 21 and the evaporator 25 and between the evaporator 25 and the compressor 17.

When the refrigeration cycle is stopped,
The control unit 34 functions to close the contact R-2 of the blower drive circuit M2-2 and turn on the alarm device 37 based on the detection signals input from the combustible refrigerant detection sensors S3 and S4. Since the rotational speed of the heat-dissipating blower at this time is for the purpose of diffusing the refrigerant, for example, low-speed rotation is given by control means such as inverter control, so that energy saving and noise reduction can be achieved.

6 and 7 show a flow for explaining the movement of the on-off valves a and b.

FIG. 7 is a flow chart showing an embodiment on the side of the condenser 11 which is the high pressure side, in which the flammable refrigerant detection sensor S4 judges a detection leak (step 101). The contact R-1 of the compressor drive circuit M1-1 is opened to stop the compressor 17 (step 1
02), the discharge pressure detector S7 provided on the discharge side of the compressor 17 determines whether the discharge pressure Pd is less than or equal to a set value (step 103). Next, when it becomes less than the set value, the on-off valves a and b are closed to shut off the refrigerant circuit.

This eliminates the ignition source. Further, the pressure on the high-pressure side is reduced to reduce leakage, and the refrigerant in the evaporator 25 is trapped (step 1
04).

FIG. 6 is a flow chart showing an embodiment on the side of the evaporator 25 which is the low pressure side. The combustible refrigerant detection sensor S3 judges a detection leak (step 201). By the air blower 27 for cooling the inside,
The compressor 17 is stopped and the on-off valves a and b are closed (steps 203 and 204). As a result, the inside 35
Refrigerant will not be sent to and the ignition source will disappear. Moreover, the refrigerant in the evaporator 25 is trapped.

FIG. 8 shows a concrete example of the cold air shut-off means, which is an embodiment in which a cool air shut-off means shutter 39 is provided at the cold air outlet 29 and the inside air return port 31.

The shutter 39 is a cam type which is controlled to be opened and closed by a cam 43 driven by a drive motor 41, and its operation flow is shown in FIG.

That is, the presence or absence of refrigerant leakage is detected by the combustible refrigerant detection sensors S3 and S4 (step 301), and when it is judged that there is refrigerant leakage, the drive motor 41 is turned on (step 302), and the drive motor 41 is operated. Shutter 3
9 is closed (step 303) and the alarm device 37 is turned on (step 304). As a result, the inside 35
The passage leading to will be blocked.

The shutter 39 is not limited to the cam type. For example, as shown in FIG. 10, the shutter 39 may be a bellows type in which the shutter 39 is controlled by a bellows 45 operated by the discharge pressure from the compressor 17. FIG. 11 shows the operation flow.

That is, the presence or absence of refrigerant leakage is detected by the combustible refrigerant detection sensors S3 and S4 (step 401). If it is determined that there is refrigerant leakage, the compressor 17 is stopped (step 402) and the bellows 45 is opened. As a result, the shutter 39 is closed (step 403) and the alarm device 37 is turned on (step 405). As a result, the passage leading to the inside 35 is blocked.

FIG. 12 shows a refrigerant recovery means for recovering the refrigerant in the refrigeration cycle when a refrigerant leak occurs.

In the compressor 17, the condenser 11, the expansion device 21, and the evaporator 25 which constitute the refrigeration cycle, the compressor 1
At the discharge side of 7, the refrigerant recovery tank 47 is provided in parallel with the condenser 17.
And a first opening / closing valve c for cutting / contacting the refrigerant flow to the condenser 11 side and a second opening / closing valve d for cutting / contacting the refrigerant flow to the refrigerant recovery tank 47 side. The refrigerant recovery tank 47 is arranged on the downstream side of the heat-dissipating blower 15, and the refrigerant recovery tank 47 is cooled so that the refrigerant can be recovered.
FIG. 14 shows another embodiment of the cooling method of the refrigerant recovery tank 47.

The refrigerant recovery tank 47 is surrounded by a heat insulating material 51 and is housed in a cooling tank 55 in which a refrigerant liquid 53 such as CO ₂ is sealed. On the outer circumference of the refrigerant recovery tank 47, a third opening / closing valve e which is opened to the atmosphere by being opened
A capillary tube 57 having a is wound.

The operation of the first and second on-off valves c and d and the third on-off valve e will be described with reference to the flow chart of FIG. 13. Existence of refrigerant leakage is detected by the flammable refrigerant detection sensors S3 and S4 (step 501). ), If it is determined that there is a refrigerant leak, the first on-off valve c is closed and the second on-off valve d is opened (step 5).
02). The refrigerant from the compressor 17 is sent into the refrigerant recovery tank 47, and the refrigerant liquid such as CO ₂ is gasified and the pressure rises. Next, the third on-off valve e is opened (step 503),
The refrigerant recovery tank 47 is cooled by the rapid expansion of the refrigerant liquid. At this time, in the refrigerant recovery tank 47, the high-temperature refrigerant gas is liquefied and has a low pressure, and is collected in the refrigerant recovery tank 47 in a liquefied state.

Next, the discharge pressure detection sensor S7 provided on the discharge side of the compressor 17 determines whether or not the discharge pressure Pd is a set value (step 504). When the discharge pressure Pd is below the set value, the second on-off valve d is opened. The compressor 17 is closed and the compressor 17 is stopped (steps 505 and 506).

FIG. 15 shows another embodiment of the refrigerator-freezer which has taken safety measures. An opening / closing detection switch 59 is provided on the opening / closing door 5, and the inside of the refrigerator is cooled by a detection signal from the opening / closing detection switch 59. The structure is such that the blower 27 is turned off.

The relationship between the open / close detection switch 59 and the internal cooling blower 27 will be specifically described with reference to the flow shown in FIG. 16. The open / close detection switch 59 is ON or OFF, that is,
It is determined whether the door 5 is open or closed (step 601). The open / close door 5 is determined to be open, and the opening time is managed (step 602). At this time, when it is determined that the opening time of the opening / closing door 5 is equal to or longer than the predetermined time, the inside cooling fan 27 is stopped (step 603). As a result, when a refrigerant leak occurs in the inside 35, it is diffused by the inside cooling blower 27 so as not to reach a combustible concentration, and is quickly discharged outside by opening the opening / closing door 5. .

The heat-dissipating blower 15 can be operated at a low speed depending on the temperature of the condenser or the outside air temperature. FIG. 17 shows a control flow of the heat radiation blower 15 during normal operation and low speed operation.

That is, it is judged whether the compressor 17 is in operation or stopped (step 701), and if it is stopped (NO),
The blower stop time is integrated (step 702). At this time, it is judged whether or not the blower has reached a certain time (step 703), and in the case of NO, the circulation returning to step 702 is repeated. If YES in step 703, the blower is operated at a low speed for a fixed time (step 704).

On the other hand, it is judged that the compressor 17 is in operation, and it is judged whether or not the temperature of the condenser is below a certain temperature (step 705). When it is above the certain temperature, normal operation is performed (step 706). Further, it is determined whether the condenser temperature is below a certain temperature and the outside air temperature is below a certain temperature (step 707). When the outside air temperature is below the certain temperature, low speed operation is performed (step 708). In this case, step 70
In Fig. 7, when the outside air temperature is equal to or higher than a certain temperature, normal operation is performed.

According to the refrigerator-refrigerator thus constructed, the refrigerant discharged from the compressor 17 passes through the condenser 11 → the expansion device 21 → the evaporator 25 and returns to the compressor 17 again to constitute a refrigeration cycle. Like During this refrigeration cycle, in the evaporator 25, the latent heat of evaporation is taken from the surrounding air through the fins to cool the air into cold air, and the cold air is sent to the inside 35 by the inside cooling fan 27 to cool the inside 35. Done.

When the refrigerant leaks during this refrigerant cycle operation, the flammable refrigerant detection sensors S3 and S4 serving as refrigerant leakage detection means detect it, and, for example, close the first on-off valve c,
By opening the second opening / closing valve d, the refrigerant from the compressor 17 is recovered in the refrigerant recovery tank 47 serving as a refrigerant recovery means. In this case, by opening the third opening / closing valve e, the refrigerant recovery tank 747 is cooled by the expansion of the refrigerant liquid, and in the refrigerant recovery tank 47, the high temperature refrigerant gas is liquefied and becomes a low pressure and is accumulated in a liquefied state. . As a result, it is possible to minimize the leakage of the refrigerant into the inside of the refrigerator, and it is possible to reliably prevent the combustible concentration from exploding.

[0048]

As described above, according to the present invention, since the leaked refrigerant can be reliably recovered by the refrigerant recovery means, it is possible to minimize the leakage of the refrigerant to the outside and to explode. It is possible to reliably prevent the combustible concentration from being reached and to ensure safety.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing the arrangement of a compressor, a condenser, a throttle device, and an evaporator that constitute a refrigeration cycle.

FIG. 2 is a cut-away side view of a refrigerator-freezer embodying the present invention.

FIG. 3 is an explanatory view showing a refrigeration cycle.

FIG. 4 is an explanatory diagram showing a compressor drive circuit and a heat dissipation drive circuit.

FIG. 5 is an explanatory view in which cold air shut-off means is provided at the cold air outlet and the in-compartment air return port.

FIG. 6 is a flowchart showing an operation of leak detection on the evaporator side.

FIG. 7 is a flowchart showing an operation of leak detection on the evaporator side.

FIG. 8 is an explanatory diagram of a cam type in which a shutter that serves as a cool air blocking unit is driven by a cam.

9 is a flowchart showing the operation of FIG.

FIG. 10 is an explanatory view of a bellows type in which a shutter serving as a cool air cutoff unit is driven by a bellows.

11 is a flowchart showing the operation of FIG.

FIG. 12 is an explanatory circuit diagram showing a refrigerant recovery means.

13 is a flowchart showing the operation of FIG.

FIG. 14 is an explanatory diagram showing a specific example of a refrigerant recovery device.

FIG. 15 is a cutaway side view in which an opening / closing detection switch is provided on the opening / closing door of the refrigerator body.

16 is a flowchart showing the operation of the open / close detection switch of FIG.

FIG. 17 is a control flow chart showing a normal operation and a low speed operation of the fan for heat radiation.

[Explanation of symbols]

11 ... Condenser 17 ... Compressor 21 ... Throttling device 25 ... Evaporator 47 ... Refrigerant recovery tank (refrigerant recovery means) 51 ... Insulation material 53 ... Refrigerant liquid 55 ... Cooling tank 57 ... Capillary tube c ... First on-off valve d ... Second on-off valve c ... Third on-off valve S3, SA ... Combustible refrigerant detection sensor (refrigerant leak detection means) S7 ... Discharge pressure detection sensor (discharge pressure detection means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25D 11/00 101 F25D 11/00 101B (72) Inventor Koji Kashima 1-6 Ota Toshiba-cho, Ibaraki-shi, Osaka No. Stock Company Toshiba Osaka Factory (72) Inventor Tetsuo Sano 336 Tatehara, Fuji City, Shizuoka Prefecture Toshiba Fuji Co., Ltd. (72) Inventor Masao Ozu 336 Tatehara Fuji City, Shizuoka Prefecture F Term, Toshiba Fuji Factory Co., Ltd. (Reference) 3L045 AA03 DA02 JA14 KA07 LA17 MA09

Claims (4)

[Claims] 1. A refrigeration cycle in which refrigerant discharged from a compressor passes through a condenser, a throttle device, and an evaporator and returns to the compressor, and a refrigerant connected to the discharge side of the compressor in parallel with the condenser. Recovery means, a first opening / closing valve for cutting / contacting the flow of the refrigerant to the condenser, a second opening / closing valve for cutting / contacting the flow of the refrigerant to the refrigerant recovery means, and a refrigerant leakage detection means for detecting refrigerant leakage And using a flammable refrigerant as the refrigerant, while closing the first opening / closing valve and opening the second opening / closing valve when the refrigerant leakage means detects a refrigerant leakage, the compressor Refrigerator / refrigerator, characterized in that the refrigerant from the above is recovered by the refrigerant recovery means. 2. The refrigerator / freezer according to claim 1, wherein the refrigerant recovery means is covered with a heat insulating material and is housed in a cooling tank in which a refrigerant liquid is sealed. 3. The refrigerator / freezer according to claim 2, wherein a capillary tube having a third opening / closing valve that can be opened to the atmosphere is provided on the outer periphery of the refrigerant recovery means. 4. After the refrigerant from the compressor is recovered by the refrigerant recovery means, the third opening / closing valve is opened, and then the discharge pressure of the compressor detected by the discharge pressure detecting means provided in the compressor is changed. The refrigerator / freezer according to claim 3, wherein the second on-off valve is closed and the compressor is stopped when the value becomes equal to or less than a predetermined set value.