WO2022102026A1

WO2022102026A1 - Refrigeration cycle device

Info

Publication number: WO2022102026A1
Application number: PCT/JP2020/042126
Authority: WO
Inventors: 健嗣小島; 研吾平塚; 悟外山; 愛実中村
Original assignee: 三菱電機株式会社
Priority date: 2020-11-11
Filing date: 2020-11-11
Publication date: 2022-05-19

Abstract

Provided is a refrigeration cycle device comprising a refrigeration circuit that includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve. A refrigerant is sealed within the refrigeration circuit, and the refrigerant includes an unsaturated fluorinated hydrocarbon compound. The compressor is filled with a refrigerator oil, and the refrigerator oil contains at least one compound of a first compound represented by chemical formula 1 and a second compound represented by chemical formula 2. In chemical formula 1: each of R1-R5 is a substituent configured from at least one atom of a carbon atom, a hydrogen atom, and an oxygen atom; and R6-R8 are substituents, at least one of which is a hydrogen atom, and the remainder of which are configured from at least one atom of a carbon atom, a hydrogen atom, and an oxygen atom. In chemical formula (2): R1 is a substituent that forms a ring structure with the neighboring carbon atoms, the ring structure being a 5- to 8-membered carbon ring or heterocycle; each of R2-R5 is a substituent configured from at least one of a carbon atom, a hydrogen atom, and an oxygen atom; and R6-R7 are substituents, at least one of which is a hydrogen atom, and the remainder of which are configured from at least one of a carbon atom, a hydrogen atom, and an oxygen atom.

Description

Refrigeration cycle device

This disclosure relates to a refrigeration cycle device.

Currently, the use of refrigerant used in refrigeration cycle equipment is restricted by the Freon Emission Control Law (enforced in April 2015), specifically by the Global Warming Potential (GWP).

For this reason, a refrigerant that takes GWP into consideration is used. As such a refrigerant, Patent Document 1 (Japanese Patent No. 5777566) describes unsaturated fluorohydrocarbon compounds (Hydro-Fluoro-) such as 2,3,3,3-tetrafluoropropene (R1234yf) having a low GWP. Olefin: HFO) is disclosed.

However, unsaturated fluorinated hydrocarbon compounds are unstable compounds that are more easily decomposed than saturated fluorinated hydrocarbon compounds (Hydr-Fluoro-Carbon: HFC). It was a challenge to maintain the long-term reliability of the machine.

In response to such problems, Patent Document 2 (Japanese Patent No. 66935112) describes a lubricating oil for a compressor as a stabilizer such as a phenol compound, an unsaturated hydrocarbon group-containing aromatic compound, an aromatic amine compound and the like. Saturated fluoride by suppressing the increase in the concentration of acid generated by the decomposition of the refrigerant containing the unsaturated fluorohydrocarbon compound and capturing the radical generated by the decomposition of the refrigerant containing the unsaturated fluorohydrocarbon compound. It is disclosed to suppress further decomposition of hydrocarbon compounds, deterioration of refrigerating machine oil and corrosion of metals.

However, the compound described in Patent Document 2 has a problem that it does not have an effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound sufficiently to maintain the long-term reliability of the refrigerating cycle apparatus and the compressor. be.

Japanese Patent No. 5777566 Japanese Patent No. 66935112

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a refrigeration cycle apparatus that maintains reliability for a long period of time by using a refrigerant containing an unsaturated fluorinated hydrocarbon compound.

The refrigeration cycle apparatus according to the present disclosure includes a refrigeration circuit including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and an expansion valve. A refrigerant is sealed in the refrigeration circuit, and the refrigerant contains an unsaturated fluorinated hydrocarbon compound. The compressor is filled with refrigerating machine oil, and the refrigerating machine oil contains at least one of the first compound represented by the following chemical formula 1 and the second compound represented by the following chemical formula 2.

In the above chemical formula 1, R ₁ to R ₅ are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom, and R ₆ to R ₈ have at least one hydrogen atom and the others. It is a substituent composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom. In the above chemical formula 2, R ₁ is a substituent forming a ring structure with an adjacent carbon atom, and R ₂ to R ₅ are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom. Yes, R ₆ to R ₇ are substituents in which at least one is a hydrogen atom and the other is composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom.

According to the present disclosure, it is possible to provide a refrigeration cycle apparatus that maintains reliability for a long period of time by using a refrigerant containing an unsaturated fluorinated hydrocarbon compound.

It is a schematic block diagram which shows the refrigerating cycle apparatus which concerns on Embodiment 1. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
Embodiment 1.
First, the outline of the refrigerating cycle apparatus of this embodiment will be briefly described. FIG. 1 is a schematic configuration diagram showing a refrigeration cycle apparatus according to the first embodiment. The refrigeration cycle device includes a compressor 1, a flow path switching valve 2 for switching the flow direction during cooling and heating, an outdoor heat exchanger 3, an expansion valve 4, and a refrigerating circuit including an indoor heat exchanger 5. Be prepared. The flow path switching valve 2 is not required in the refrigeration cycle device that does not need to switch between cooling and heating.

During cooling, the high-temperature and high-pressure gaseous refrigerant compressed by the compressor 1 flows into the outdoor heat exchanger 3 via the flow path switching valve 2 (flow path shown by the solid line) and condenses there. The liquid refrigerant condensed in the outdoor heat exchanger 3 flows into the indoor heat exchanger 5 via the expansion valve 4 and evaporates (vaporizes) there. Finally, the gaseous refrigerant evaporated in the indoor heat exchanger 5 returns to the compressor 1 via the flow path switching valve 2 (flow path shown by the solid line). As described above, during cooling, the refrigerant circulates in the refrigerating circuit of the refrigerating cycle device in the direction of the solid arrow shown in FIG.

On the other hand, during heating, the high-temperature and high-pressure gaseous refrigerant compressed by the compressor 1 flows into the indoor heat exchanger 5 via the flow path switching valve 2 (flow path shown by the dotted line) and condenses there. do. The liquid refrigerant condensed in the indoor heat exchanger 5 flows into the outdoor heat exchanger 3 via the expansion valve 4 and evaporates (vaporizes) there. The refrigerant evaporated in the outdoor heat exchanger 3 returns to the compressor 1 via the flow path switching valve 2 (flow path shown by the dotted line). As described above, during heating, the refrigerant circulates in the refrigerating circuit of the refrigerating cycle device in the direction of the broken line arrow shown in FIG.

The above configuration is the minimum component of the refrigeration cycle device capable of performing cooling and heating operations. The refrigeration cycle apparatus of the present embodiment may further include other equipment such as a gas-liquid branching device, a receiver, an accumulator, and a high / low pressure heat exchanger.

(Refrigerant)
Next, in the present embodiment, the refrigerant enclosed in the refrigeration circuit will be described. The refrigerant contains an unsaturated fluorinated hydrocarbon compound.

Further, the refrigerant used in the present embodiment may be only an unsaturated fluorinated hydrocarbon compound, or may further contain other components. Examples of other components include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), hydrofluoroolefins (HFOs), and natural refrigerants containing hydrocarbons. The blending ratio of other components and the like are set within a range that does not interfere with the main effects of the present embodiment. When the unsaturated fluorinated hydrocarbon compound further contains other components, the unsaturated fluorinated hydrocarbon compound is preferably 1 to 80% by mass with respect to the total amount of the refrigerant.

(Refrigerator oil)
Next, in the present embodiment, the refrigerating machine oil filled to lubricate the inside of the compressor will be described. Examples of the refrigerating machine oil include commonly used refrigerating machine oils (ester-based lubricating oil, ether-based lubricating oil, fluorine-based lubricating oil, mineral-based lubricating oil, hydrocarbon-based lubricating oil, etc.). In that case, it is preferable to select a refrigerating machine oil which is excellent in terms of compatibility with the refrigerant and stability. Specific examples of the refrigerating machine oil include, but are not limited to, polyalkylene glycol, polyol ester, polyvinyl ether, alkylbenzene, mineral oil and the like.

The refrigerating machine oil contains at least one of the first compound represented by the chemical formula 1 and the second compound represented by the chemical formula 2 as additives.

The decomposition reaction of the unsaturated fluorinated hydrocarbon compound and the reaction in which the radicals generated by the decomposition are captured by the compound are as shown in Chemical Formula 3 below.

From the above chemical formula 3, the basic skeleton of the compound having the effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound is either the first compound represented by the chemical formula 1 or the second compound represented by the chemical formula 2. ..

In the first compound represented by the chemical formula 1, R ₁ to R ₅ are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom, preferably a hydrogen atom, a methoxy group, an ethoxy group and an alkyl. At least one of the groups. R ₁ to R ₅ may be the same or different. Further, at least one of the substituents of R ₆ to R ₈ is a hydrogen atom. Others are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom, and preferably at least one of a hydrogen atom, a methoxy group, an ethoxy group and an alkyl group. R ₆ to R ₈ may be the same or different.

Further, in the chemical formula 1, R ₃ is -O-R ₉ , R ₉ is a hydrocarbon group having 1 to 10 carbon atoms, R ₇ is -COO-R ₁₀ , and R ₁₀ is. , 1 to 10 carbon atoms, and R ₁ to R ₂ , R ₄ to R ₆ and R ₈ may be hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms. The range of carbon numbers of R ₁ to R ₂ , R ₄ to R ₆ and R ₈ to R ₁₀ is an example, and the present disclosure is not limited to the above range.

Examples of the first compound include ethylhexyl methoxycinnamate, anethole and cinnamil acetate, with ethylhexyl methoxycinnamate and anethole being preferred.

The content of the first compound in the refrigerating machine oil is preferably 1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the refrigerating machine oil. It is preferably 4% by mass or more and 8% by mass or less.

In the second compound represented by the chemical formula 2, R ₂ to R ₅ are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom, preferably a hydrogen atom, a methoxy group, an ethoxy group and an alkyl. At least one of the groups. R ₂ to R ₅ may be the same or different. Further, at least one of the substituents of R ₆ to R ₇ is a hydrogen atom. Others are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom, and preferably at least one of a hydrogen atom, a methoxy group, an ethoxy group and an alkyl group. R ₆ to R ₇ may be the same or different. Further, R ₁ forms a ring structure with two adjacent carbon atoms of the benzene ring to which R ₁ is bonded. The ring structure forms a 5- to 8-membered carbon ring or a heterocycle, preferably a 6-membered heterocycle.

Further, in the chemical formula 2, R ₂ to R ₆ may be a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. The range of carbon atoms of R ₂ to R ₆ is an example, and the present disclosure is not limited to the above range.

Examples of the second compound include coumarin (see chemical formula 4 below), coumarin and the like, and coumarin is preferable. Although there are precedent examples of adding fluorescent coumarin or coumarin derivative as a leakage detection agent for the refrigerant, the compound showing practical performance as a fluorescent agent is coumarin derivative, and coumarin itself is almost fluorescent. Not shown.

The content of the second compound in the refrigerating machine oil is preferably 1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less, based on the total amount of the refrigerating machine oil. It is preferably 2% by mass or more and 6% by mass or less.

The first and second compounds having a basic skeleton that enables the radical capture reaction of Chemical Formula 3 have a high effect of capturing radicals generated when the unsaturated fluorinated hydrocarbon compound is decomposed, and are undecomposed unsaturated. Suppresses decomposition of fluorohydrocarbon compounds, deterioration of refrigerating machine oil, and metal corrosion. In addition, since the first compound and the second compound have a high radical scavenging effect, the radicals of the unsaturated fluorinated hydrocarbon compound generated in the gas phase can be captured even with a minute amount of volatile matter, and the unsaturated foot in the gas phase can be captured. It has the effect of suppressing the decomposition of hydrocarbon compounds.

In the present embodiment, the refrigerating machine oil is selected from extreme pressure agents, oily agents, antioxidants, acid scavengers, metal deactivating agents and defoaming agents, as long as the object of the present disclosure is not impaired. It may contain at least one additive.
(Refrigeration cycle device)
In the present embodiment, the refrigerating cycle device is not particularly limited, but is used in a container such as a commercial or household air conditioner (air conditioner), a car air conditioner, a heat pump for a vending machine, a refrigerator, a refrigerator, or a refrigerator. Examples include a refrigerator for cooling, a chiller unit, and a turbo chiller.

Further, the refrigerating cycle device of the present embodiment can also be used for a dedicated heating cycle machine such as a floor heating device and a snow melting device. In particular, it is useful as an air conditioner (air conditioner) for business use or home use, which requires miniaturization of equipment.

In the refrigerating cycle apparatus of the present embodiment, the description is described in the case where the outdoor unit and the indoor unit are connected one-to-one, but there are a plurality of indoor units for one outdoor unit. Also, there may be a plurality of indoor units for a plurality of outdoor units.

Further, the refrigerating cycle device of the present embodiment may be a room air conditioner or a packaged air conditioner capable of switching between cooling and heating, or may be a refrigerating cycle device for low temperature equipment such as a refrigerator.

The refrigerating cycle device of the present embodiment is preferably a refrigerating cycle device (air conditioner) for air conditioning.

Examples of the refrigerating cycle device (air conditioner) for air conditioning include room air conditioners, package air conditioners, multi air conditioners for buildings, window type air conditioners, mobile air conditioners, and the like.

Embodiment 2.
The refrigerating cycle apparatus according to the present embodiment is different from the first embodiment in that it contains a lysis aid in addition to at least one of the first compound and the second compound which are additives contained in the refrigerating machine oil. ..

By blending a solubilizing agent, precipitation of the first compound and the second compound when the refrigerating machine oil is cooled can be suppressed.

Examples of the solubilizing agent include, but are not limited to, polyol esters, polyvinyl ethers, alkylbenzenes, polyalkylene glycols, and the like. The solubilizing agent is preferably polyalkylene glycol. The content of polyalkylene glycol in the refrigerating machine oil is preferably 2% by mass or more and 10% by mass or less, and more preferably 4% by mass or more and 6% by mass or less, based on the total amount of the refrigerating machine oil. Since the other basic configurations are the same as those in the first embodiment, overlapping description will be omitted.

<Evaluation test 1>
The chemical stability of the sample (Examples 1 to 12) consisting of a mixture of the refrigerant and the refrigerating machine oil in the first embodiment was confirmed by an experimental method based on JIS K2211: 2009 (Annex B shield tube test). bottom. Table 1 below shows the test conditions, and Tables 2 and 3 below show the composition and evaluation results of the refrigerating machine oil.

As an evaluation result, it is used in the concentration of fluorine ion (decomposition product of unsaturated fluoride hydrocarbon compound) in the refrigerating machine oil, the acid value of the refrigerating machine oil, the hue (indicating the degree of deterioration of the refrigerating machine oil), and the above experiment. Indicates the presence or absence of gloss on the metal surface.

As an index for judging the quality of the result, the higher the effect of suppressing the decomposition of the unsaturated fluoride hydrocarbon compound, the smaller the fluorine ion concentration and the acid value.

In addition, the higher the effect of suppressing the decomposition of unsaturated fluorohydrocarbon compounds, the less the deterioration of refrigerating machine oil progresses, so the hue becomes colorless and transparent. On the contrary, if the effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound is low, the refrigerating machine oil deteriorates, the hue changes from yellow to brown, and the transparency also decreases.

Similarly, the higher the effect of suppressing the decomposition of unsaturated fluorinated hydrocarbon compounds, the more the metal surface does not discolor and the metallic luster is maintained. On the contrary, if the effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound is low, the metal surface is corroded and the metallic luster is lost.

From the above, the criteria for judging the quality of the suppression of the decomposition of the unsaturated fluorinated hydrocarbon compound are (1) fluorine ion concentration, (2) acid value, (3) hue and (4) glossiness of the metal surface. .. When the above (1) and (2) are equal to or less than the upper limit, (3) has high transparency, and (4) has metallic luster, decomposition of the unsaturated fluorinated hydrocarbon compound can be suppressed.

Although copper, iron and aluminum can be applied as the metal catalyst, copper is the most variable, so the results in Tables 2 and 3 below are judged by the gloss of the copper surface.

Further, the "gas phase" in Tables 2 and 3 below means a case where the refrigerant is in a gaseous state, and the "liquid phase" means a case where the refrigerant is in a liquid state, and the refrigerant in each state. It is determined whether or not the metal surface is glossy when the gas is brought into contact with the metal catalyst.

As shown in Tables 2 and 3, in the evaluation results of the refrigerating machine oil, Examples 1 and 7 had high fluorine ion concentrations and acid values, whereas Examples 2 to 6 and Examples 8 had high acid values. From to 12, the fluorine ion concentration and the acid value were low. From this, it is considered that Examples 2 to 6 and Examples 8 to 12 have a higher effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound than those of Examples 1 and 7. Since the hues of Examples 1 and 7 are pale yellow and it is considered that the refrigerating machine oil has not deteriorated, decomposition of the unsaturated fluorinated hydrocarbon compound is also considered in Examples 1 and 7. It is considered that there is an effect of suppressing.

Further, in the evaluation results of the metal catalyst, the gas phase and the liquid phase of Examples 1 and 7 were not glossy, whereas the gas phase and the liquid phase of Examples 2 to 6 and 8 to 12 were both dull. It was shiny. From this, it is considered that Examples 2 to 6 and Examples 8 to 12 have a higher effect of suppressing the decomposition of the unsaturated fluorinated hydrocarbon compound than those of Examples 1 and 7.

<Evaluation test 2>
As shown in Table 4 below, the samples (Examples 13 to 35) consisting of a mixture of the refrigerant and the refrigerating machine oil were held at room temperature (25 ° C) or lower in 5 ° C increments for 1 hour at each temperature within the holding time. The temperature at which the precipitation of the additive occurred was defined as the additive precipitation temperature, and the presence or absence of precipitation of the first compound and the second compound as additives was evaluated.

As an evaluation result, the temperature at which precipitation occurs when the mixture of the refrigerating machine oil and the refrigerant having the composition shown in Tables 5 and 6 below is cooled is shown as the precipitation temperature of the additive. The better the solubility of the compound in the refrigerating machine oil, the lower the precipitation temperature. Depending on the type of equipment to be applied, for example, in the case of a refrigeration cycle device, the temperature in the refrigeration circuit may drop to less than -10 ° C. Therefore, it is preferable that the precipitation temperature of the additive in the refrigerating machine oil is low.

As shown in Tables 5 and 6 above, Examples 18 to 24 and Examples 30 to 35 containing polyalkylene glycol as a solubilizing agent contain polyalkylene glycol as a solubilizing agent. The precipitation temperature of the first compound and the second compound, which are additives, was lower than that of Examples 13 to 17 and 25 to 29, which were not present. Therefore, by blending polyalkylene glycol as a solubilizing agent, precipitation of the first compound and the second compound when the refrigerating machine oil is cooled can be suppressed.

Further, in Examples 22 to 24 and Examples 33 to 35 in which the compounding ratio of polyalkylene glycol is large, Examples 18 to 21 and Examples 30 to 32 in which the compounding ratio of polyalkylene glycol is small are low. The precipitation temperature of the first compound and the second compound, which are additives, was further lowered. Therefore, by increasing the blending ratio of the polyalkylene glycol, the precipitation of the first compound and the second compound when the refrigerating machine oil is cooled can be further suppressed.

It should be considered that the embodiments and examples disclosed this time are exemplary in all respects and not restrictive. The scope of this disclosure is set forth by the claims rather than the description above and is intended to include all modifications within the meaning and scope of the claims.

1 Compressor, 2 Flow path switching valve, 3 Outdoor heat exchanger, 4 Expansion valve, 5 Indoor heat exchanger.

Claims

Equipped with a refrigeration circuit including a compressor, outdoor heat exchanger, indoor heat exchanger and expansion valve,
Refrigerant is sealed in the refrigeration circuit,
The refrigerant contains an unsaturated fluorinated hydrocarbon compound and contains
The compressor is filled with refrigerating machine oil,
The refrigerating machine oil is a refrigerating cycle apparatus containing at least one of a first compound represented by the following chemical formula 1 and a second compound represented by the following chemical formula 2.

In the chemical formula 1,
R 1 to R 5 are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom.
In R 6 to R 8 , at least one is a hydrogen atom, and the other is a substituent composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom.
In the chemical formula 2,
R 1 is a substituent that forms a ring structure with adjacent carbon atoms.
The ring structure is a 5- to 8-membered carbon ring or a heterocycle.
R 2 to R 5 are substituents composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom.
In R 6 to R 7 , at least one is a hydrogen atom, and the other is a substituent composed of at least one of a carbon atom, a hydrogen atom and an oxygen atom.
The refrigeration cycle apparatus according to claim 1, wherein the content of the unsaturated fluorinated hydrocarbon compound in the refrigerant is 1 to 80% by mass with respect to the total amount of the refrigerant.
In the chemical formula 1,
The R 7 is -COO-R 10 .
The refrigeration cycle apparatus according to claim 1 or 2, wherein the R 10 is a hydrocarbon group having 1 to 10 carbon atoms.
In the chemical formula 1,
The R 3 is −OR 9 and is
The refrigerating cycle apparatus according to any one of claims 1 to 3, wherein R 9 is a hydrocarbon group having 1 to 10 carbon atoms.
In the chemical formula 1,
The refrigerating cycle apparatus according to any one of claims 1 to 4, wherein R 1 to R 2 , R 4 to R 6 and R 8 are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms.
In the chemical formula 2,
The refrigerating cycle apparatus according to claim 1 or 2, wherein R 2 to R 6 are hydrogen atoms or hydrocarbon groups having 1 to 10 carbon atoms.
The refrigeration cycle apparatus according to claim 1 or 2, wherein the second compound is a compound represented by the following chemical formula 4.
The refrigerating cycle apparatus according to any one of claims 1 to 7, wherein the refrigerating machine oil contains a lysis aid.
The refrigeration cycle apparatus according to claim 8, wherein the lysis aid is polyalkylene glycol.