JP2002195707A - Refrigerating cycle apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable visual detection of refrigerant leakage in a refrigerating cycle device employing inflammable refrigerant. SOLUTION: The refrigerating cycle device is provided with a refrigerant detecting member, whose color changes when it is brought into contact with the inflammable refrigerant or a detection gas mixed in the inflammable refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor compression refrigeration cycle apparatus utilizing heat transfer generated during liquefaction and evaporation of a refrigerant, and more particularly, to a global warming system which has no risk of destroying the ozone layer. The present invention relates to a refrigeration cycle device using a flammable refrigerant having a small effect.

[0002]

2. Description of the Related Art Refrigerant used in a refrigeration cycle apparatus includes:
For the purpose of protecting the ozone layer, CFC (chlorofluorocarbon) such as R12 (dichlorodifluoromethane) and R2
2 (chlorodifluoromethane) or other HCFC (hydrochlorofluorocarbon) to R134a (1,1,
HFCs (hydrofluorocarbons) such as 1-tetrafluoroethane) and R410A (R32; mixed refrigerant of difluoromethane and R125; pentafluoroethane) are being replaced.

[0003] Further, hydrocarbon refrigerants such as propane and isobutane, and R32-only refrigerants, which do not destroy the ozone layer and have a small global warming effect, are being studied from these alternative refrigerants.

[0004] The above-mentioned hydrocarbon refrigerant and R32-only refrigerant have no danger of destruction of the ozone layer and have a small global warming effect. However, they are flammable and should be used as refrigerants for refrigeration cycle devices. Safety measures are needed in case of leakage.

[0005]

As a safety measure at the time of refrigerant leakage in a refrigeration cycle apparatus using a flammable refrigerant, for example, in Japanese Patent Application Laid-Open No. 10-111061, a refrigerator is provided with a refrigerant leakage detector, Techniques for operating a ventilator and warning of the occurrence of leakage of combustible refrigerant have been disclosed.

However, attaching a refrigerant leak detector to a small household refrigeration cycle device such as a refrigerator causes a remarkable increase in the price of the product, and is not practical except for a large-sized refrigerator for business use. Further, in the refrigerant detection by the sensor, it is necessary to supply power to the detection device, and it is difficult to detect a refrigerant leak due to, for example, pipe corrosion during non-operation.

In Japanese Patent Application Laid-Open No. 2000-104049,
A method is disclosed in which an odorant or a coloring agent is mixed into a combustible refrigerant to detect the occurrence of refrigerant leakage by smell or coloring of a portion near the leakage when refrigerant leakage occurs. For detection of refrigerant leakage due to odor, LPG, which is a general household fuel gas, is used.
It is widely known that odors are emitted even from city gas and city gas, and its effect has been proven as a leak detection method. Furthermore, because of the smell, the effect of ventilation can be easily confirmed, which is an effective method as a safety measure when using the equipment.

However, refrigerators are often installed in a kitchen together with a gas range, which is a gas combustor, in ordinary households, and detection of refrigerant leakage due to odor is indistinguishable from leakage of fuel gas. It is not a preferable detection method in a situation where a quick and appropriate response to the occurrence of a gas leak is required.

At the same time, the coloring of the refrigerant can be detected only in the vicinity of the leak occurrence part, and since most of the refrigerant pipes of the refrigeration cycle are housed inside the product and are less likely to be noticeable, the effect is low. You can't expect much.

According to the present invention, in a refrigeration cycle apparatus using these flammable refrigerants, safety is improved by providing a detection member capable of visually detecting refrigerant leakage, and an expensive gas sensor is used. It is intended to realize refrigerant leak detection without any cost.

[0011]

SUMMARY OF THE INVENTION A refrigeration cycle apparatus according to the present invention is a refrigeration cycle apparatus using a flammable refrigerant, wherein the refrigeration cycle device has a refrigerant detecting member that changes color when it comes into contact with the refrigerant.

Further, the refrigerant detecting member is a paint,
The components constituting the refrigeration cycle apparatus may be painted.

[0013] Further, the refrigerant detecting member may be in the form of a sheet and affixed to a component constituting the refrigeration cycle apparatus with a double-sided tape or the like.

Further, the refrigerant detecting member may be plastic, and may be a component constituting the refrigeration cycle apparatus.

[0015] Further, the refrigerant detecting member may include a noble metal compound.

Further, the refrigerant detecting member may include a pigment that changes color when it comes into contact with a predetermined component, and the flammable refrigerant may include the predetermined component.

Further, the predetermined component may be a basic gas.

Further, the predetermined component may be an acidic gas.

[0019] The pigment which changes color when it comes into contact with the predetermined component of the refrigerant detecting member may be a PH indicator.

[0020] The dye that changes color when it comes into contact with the predetermined component of the refrigerant detecting member may be a fluorescent indicator.

Further, the predetermined component may be an oxidizing substance.

Further, the predetermined component may be a reducing substance.

[0023] The dye that changes color when it comes into contact with the predetermined component of the refrigerant detection member may be an oxidation-reduction indicator.

[0024] The pigment that changes color when it comes into contact with the predetermined component of the refrigerant detecting member may be lead acetate.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention The combustible refrigerants to be considered include isobutane, propane, ammonia, methyl ether for refrigerators, and propane, ethane, R32, or mixed refrigerants containing R32 as a main component for air conditioning because of their thermophysical properties.

Noble metal compounds have been known as such substances which change color upon contact with a flammable refrigerant gas. In particular, platinum group compounds, especially palladium oxide, show a remarkable color change. In general, platinum group metals have a high standard electrode potential, and compounds such as chlorides, nitrates, sulphates and oxides undergo a reducing action when contacted with flammable gas such as hydrogen, and are easily converted to single metals. Change.

Specifically, palladium oxide is impregnated into paper to form a sheet-like member, which is attached to a corresponding part of a refrigeration cycle apparatus with a double-sided tape or the like, or mixed with a white paint to coat the corresponding part. By detecting the presence of flammable refrigerant by detecting the presence of flammable refrigerant by changing the color from yellow-brown to black when these detection components come in contact with flammable refrigerant by kneading the plastic material used for the corresponding component to form parts. The user can visually check the leakage of the flammable refrigerant.

Embodiment 2 of the Invention A dye that changes color upon contact with a predetermined component is used as a detection member, and the combustible refrigerant contains the predetermined component.

Specifically, a basic gas or an acidic gas is used as a predetermined component to be mixed with the flammable refrigerant, and a combination using a PH indicator or a fluorescent indicator is used for the detecting member, or There is a combination in which an oxidizing or reducing substance is mixed and a redox indicator or lead acetate is used for a detecting member.

Examples of the basic gas include ammonia, methylamine and fluoroamine, and examples of the acidic gas include sulfurous acid gas and nitrogen oxide.

As the PH indicator, litmus dye, neutral red, phenol red, promocresol green, promocresol purple, methyl red, and the like can be used. Among them, only one kind or a mixture of two or more kinds can be used. You can also. Further, among these PH indicators, those having a discoloration range due to PH of about 7 are easy to use, and in that sense, litmus dye and promocresol purple are preferable.

Further, a combination using a curcumin dye which changes color upon contact with only a basic gas may be used.

Table 1 shows the combinations of the mixed gas components in the combustible refrigerant and the dyes for detection.

[Table 1]

As described above, the detection dye corresponding to the mixed gas component in the flammable refrigerant is impregnated into paper to form a sheet-like member, which is affixed to the corresponding part of the refrigeration cycle apparatus with a double-sided tape or the like, or By mixing with the base paint and painting on the corresponding parts, or even kneading the plastic material used for the corresponding parts to form parts, the discoloration occurs when these detecting parts come in contact with the flammable refrigerant containing the mixed gas Thus, the presence of the flammable refrigerant is detected, and the discoloration allows the user to visually check the leakage of the flammable refrigerant.

[0035]

[Embodiment 1] FIG. 1 shows a front view and a cross-sectional view of a refrigerator according to a first embodiment of the present invention. The refrigerator according to the first embodiment of the present invention uses isobutane as a refrigerant. The refrigerator compresses isobutane, which is a refrigerant, with the compressor 1, cools the high-temperature, high-pressure gas refrigerant into a liquid by cooling it with the outside air temperature with the condenser, decompresses with the capillary tube, and evaporates with the cooler 2 to evaporate the inside of the refrigerator. Cooling. Thereafter, the low-temperature and low-pressure refrigerant is returned to the compressor and circulates in the refrigeration cycle. The air 5 cooled by heat exchange in the cooler 2 in the refrigerator is sent to the refrigerating room 6, the switching room 7, the vegetable room 8 and the freezing room 9 by the fan 3 in the refrigerator to cool each room.

The refrigerator of the first embodiment uses an internal volume of 400 liters and the refrigerant isobutane uses 80 g. Since the gas volume of 80 grams of isobutane is about 30 liters (at 5 ° C.), for example, under the condition that all the refrigerant leaks rapidly into the inside of the refrigerator and there is no ventilation outside the refrigerator, it is about 7.
A mixture of isobutane and air of 5% by volume will be produced. The flammable range of isobutane is 1.8% by volume to 8.5%.
% And falls within this range.

In reality, there is no condition that there is no ventilation outside the refrigerator, and since the refrigerant pressure is low in the refrigerant pipe near the cooler 2 which is lower in temperature than outside the refrigerator, all the refrigerant leaks into the refrigerator. Although it is unlikely that the flammable range will be retained, it may be considered that the flammable range may be reached transiently.

The refrigerant detecting member impregnates filter paper with a palladium oxide suspension obtained by hydrolyzing palladium nitrate,
After drying sufficiently, use one sealed with a polyethylene sheet having a thickness of 0.1 mm. This refrigerant leak detection sheet is attached to the refrigerator with double-sided tape.

When the in-compartment fan 3 is operated and cool air is circulating, the leaked refrigerant is instantaneously diffused and can be detected anywhere in the refrigerator. Must be provided in a position where it can be seen.

In the first embodiment, as shown in FIG. 1, the refrigerant leak detection sheet 4 corresponding to the refrigerant leakage into the refrigerator is provided near the cold air duct of the refrigerator compartment, and the refrigerant leakage detection sheet 4 responds to the refrigerant leakage to the piping outside the refrigerator. The leak detection sheet 11 is stuck on the front of the refrigerator bottom duct.

This is because the refrigerator blows a fan to cool the compressor 1 and the condenser with outside air, and the duct is installed at the bottom of the refrigerator. The danger of ignition due to refrigerant leakage from the outside piping changes depending on external conditions such as the location of the refrigerator and ventilation, but the specific gravity of isobutane used as a refrigerant is larger than air, and therefore it is highly likely that it will stay on the floor surface by.

When 1% by volume of isobutane was circulated in the refrigerator using the refrigerator of Example 1, discoloration of the detection sheet was recognized, and it was confirmed that refrigerant leakage could be detected.

Further, although the palladium oxide impregnated paper is coated with the polyethylene sheet for the refrigerant leak detection sheet, it is needless to say that the refrigerant can be detected without the polyethylene sheet. Since the polyethylene sheet has low hygroscopicity and high gas permeability, the secular change can be reduced without lowering the sensitivity due to moisture absorption.

Further, in the above, the palladium oxide impregnated paper is adhered to the refrigerator parts with a double-sided tape as a refrigerant leakage detection sheet. However, as shown in FIG. May be printed, and the surface of the component itself may be used as a refrigerant leak detection member.

Embodiment 2 FIG. FIG. 4 shows a front view and a side view of an indoor unit of an air conditioner according to Embodiment 2 of the present invention.

In the figure, an indoor unit of an air conditioner according to Embodiment 2 of the present invention has an air intake port 22 on a front panel 21,
An air outlet 23 and a remote control light receiver 24 are provided. The air conditioner according to the second embodiment of the present invention uses R32 as a refrigerant, and contains 100 vol.
pm.

In the refrigerant leak detection, a water-soluble paint containing promocresol purple is used, and the vicinity 25 of the air outlet 23 of the front panel 21 of the indoor unit of the air conditioner is subjected to a coating process. And

Although promocresol purple dissociates in the paint to show acidity and turns yellow, it turns purple when contacted with a basic gas such as ammonia.

In Example 2, in consideration of the weather resistance of the coating film and the effect on the front panel material, about 0.2% by weight of promocresol purple was mixed into the paint so as to have a pH of 4.5.

A volume of 100 p of ammonia according to the second embodiment
An exposure test was performed on the coating film of Example 2 in an atmosphere in which R32 refrigerant containing pm was set to 10% by volume with respect to air, and it was confirmed that the coating film discolored.

The R32 refrigerant has a flammable range of 13.3% by volume.
２９29.3% by volume. From the above results, it was found that
It can be seen that refrigerant leakage detection is possible by the discoloration of the 32 refrigerant before reaching the lower limit of the flammable range.

Embodiment 3 FIG. FIG. 5 shows a front view and a side view of an indoor unit of an air conditioner according to Embodiment 3 of the present invention.

In the figure, an indoor unit of an air conditioner according to Embodiment 3 of the present invention has an air
A remote control light receiver 24 is provided.

The air conditioner according to the third embodiment of the present invention
2, and 10 volume ppm of ethyl mercaptan was mixed therein as a detection component.

For the refrigerant leak detection, an indoor unit air blowing vane 26 made of impact-resistant polystyrene mixed with 5% by weight of lead acetate is used as a refrigerant detecting member.

Ethyl mercaptan 10 according to Example 3
An exposure test was performed on the molded air blow-out vane 26 according to Example 3 in an atmosphere in which the R32 refrigerant containing ppm by volume was 10% by volume with respect to air, and it was confirmed that the discoloration was observed.

[0057]

The refrigeration cycle apparatus according to the present invention uses a flammable refrigerant and has a refrigerant detecting member that changes color when it comes into contact with the flammable refrigerant. Can be confirmed.

The refrigerant detecting member is a combustible refrigerant or a dye that changes its color in response to a detection gas mixed with the combustible refrigerant. Since the corresponding component itself is used as the detection member by coating or printing on the component or mixed with the plastic material, a warning means for visually notifying the occurrence of refrigerant leakage can be easily realized at low cost.

Further, since no power supply or the like is required for operation, regardless of whether the refrigeration cycle apparatus is operating or not.
For example, it is also possible to detect the occurrence of refrigerant leakage due to corrosion of the piping.

[Brief description of the drawings]

FIG. 1 is a front view and a side sectional view of a refrigerator according to a first embodiment of the present invention.

FIG. 2 is an example of a refrigerant detection sheet according to the first embodiment of the present invention.

FIG. 3 is a printing example of a refrigerant detection paint according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram of an air conditioner indoor unit according to a second embodiment of the present invention.

FIG. 5 is a schematic diagram of an air conditioner indoor unit according to a third embodiment of the present invention.

[Explanation of symbols]

1 compressor, 2 cooler,
3 Inside fan, 4 Inside detection sheet, 5
Cold air in the refrigerator, 6 Refrigerator room, 7 Temperature switching room, 8 Vegetable room, 9 Freezer room, 10 Cooling air outside the refrigerator, 11 Outside detection sheet, 21 Indoor unit front panel, 22 Air inlet,
23 air outlet, 24 remote control receiver,
25 Refrigerant detection coating unit, 26 Air blow-out vane

Claims (14)

[Claims] 1. A refrigeration cycle apparatus using a flammable refrigerant, wherein the refrigeration cycle apparatus has a refrigerant detection member that changes color when it comes into contact with the refrigerant. 2. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant detection member is a paint, and is applied to a part constituting the refrigeration cycle apparatus. 3. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant detection member is sheet-shaped, and is attached to a component constituting the refrigeration cycle apparatus with a double-sided tape or the like. 4. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant detection member is made of plastic and is a component constituting the refrigeration cycle apparatus. 5. The refrigeration cycle apparatus according to claim 1, wherein said refrigerant detection member contains a noble metal-based compound. 6. A refrigeration system according to claim 1, wherein said refrigerant detecting member includes a pigment that changes color when it comes into contact with a predetermined component, and said flammable refrigerant includes said predetermined component. Cycle equipment. 7. The refrigeration cycle apparatus according to claim 6, wherein said predetermined component is a basic gas. 8. The refrigeration cycle apparatus according to claim 6, wherein said predetermined component is an acid gas. 9. The refrigeration cycle apparatus according to claim 7, wherein the pigment that changes color when it comes into contact with the predetermined component of the refrigerant detection member is a PH indicator. 10. The refrigeration cycle apparatus according to claim 7, wherein the dye that changes color when it comes into contact with the predetermined component of the refrigerant detection member is a fluorescent indicator. 11. The refrigeration cycle apparatus according to claim 6, wherein said predetermined component is an oxidizing substance. 12. The refrigeration cycle apparatus according to claim 6, wherein said predetermined component is a reducing substance. 13. The refrigeration cycle apparatus according to claim 11, wherein the pigment that changes color when it comes into contact with the predetermined component of the refrigerant detection member is a redox indicator. 14. The refrigeration cycle apparatus according to claim 11, wherein the pigment that changes color when it comes into contact with the predetermined component of the refrigerant detection member is lead acetate.