Compressor and refrigeration cycle device

Abstract

To provide a compressor with improved sliding properties at sliding parts. To achieve this object, a compressor 100 is provided, which is equipped with a high-pressure chamber type sealed container 1 in which a refrigerant containing 50% by mass or more of a hydrofluoroolefin refrigerant and a refrigeration oil are sealed, and a compression mechanism unit 8 housed in the sealed container 1 and having sliding parts 9 made of an iron-based material, the refrigeration oil containing at least one of polyvinyl ether and polyol ester, and the kinetic viscosity of the refrigeration oil at 40°C is 10 mm 2 / s or more 40mm 2 / s or less.

Description

[Technical field]

[0001] The present disclosure relates to a compressor and a refrigeration cycle device. [Background technology]

[0002] The R410A refrigerant, which is the mainstream refrigeration cycle equipment in refrigerators, freezers, commercial air conditioners, etc., has a high global warming potential (GWP) of 2090, and is being changed to refrigerants with lower GWP values ​​in order to curb global warming. For example, the R454C refrigerant, a next-generation low-GWP candidate refrigerant, is a mixed refrigerant containing 78.5% by mass of R1234yf and 21.5% by mass of R32.

[0003] The abstract of Patent Document 1 describes "a composition comprising a refrigerant and a refrigerating machine oil, wherein the refrigerant comprises at least one refrigerant selected from the group consisting of HFO-1141, HFO-1132(E / Z), HFO-1132a, HFO-1123, and HFO-1114, and the refrigerating machine oil has a contact angle of 0.1°≦Θ≦90° with a substrate constituted by at least one selected from the group consisting of engineering plastics, organic films, inorganic films, glass, and metal parts." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-132670 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a hydrofluoroolefin refrigerant (hereinafter referred to as HFO refrigerant) and a hydrofluorocarbon refrigerant (hereinafter referred to as HFC refrigerant) are used in combination, depending on the ratio of the HFO refrigerant and the HFC refrigerant used, the performance such as the refrigeration capacity may be lower than when the refrigerants are not used in combination. For example, when calculating with R454C refrigerant, under the rated temperature H condition in Table 1 of JIS-B8600 "Rated temperature conditions for refrigerant compressors", the theoretical refrigeration capacity is about 35% lower than that of R410A refrigerant. In order to ensure the refrigeration capacity, in the case of a compressor driven by an inverter, it is possible to increase the operating speed (rotational speed). However, the PV value of the bearing increases by the increase in the rotational speed. For this reason, it is preferable to have high sliding properties.

[0006] In the invention described in Patent Document 1, disproportionation of the refrigerant is considered (paragraph 0059, etc.), but no consideration is given to improving the sliding properties of the sliding parts (bearings, etc.) of the compressor. An object of the present disclosure is to provide a compressor and a refrigeration cycle device in which the sliding properties of sliding parts are improved. [Means for solving the problem]

[0007] The compressor of the present disclosure includes a high-pressure chamber-type sealed container in which a refrigerant containing 50% by mass or more of a hydrofluoroolefin refrigerant and a refrigeration oil are sealed, and a refrigerant oil is contained in the sealed container and made of an iron-based material. The film containing fluorine derived from the hydrofluoroolefin refrigerant slides on the surface of the film formed on the surface. and a compression mechanism having a sliding portion, the refrigeration oil containing at least one of polyvinyl ether and polyol ester, the kinetic viscosity of the refrigeration oil at 40°C being 10 mm 2 / s or more 40mm 2 / s or less The hydrofluoroolefin refrigerant is at least one of R1234yf and R1234ze. Other solutions are described later in the description of the embodiment. Effect of the Invention

[0008] According to the present disclosure, it is possible to provide a compressor and a refrigeration cycle device in which the sliding properties of the sliding parts are improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view showing a compressor of the present disclosure. [Diagram 2] FIG. 4 is a cross-sectional view showing the vicinity of a sliding portion. [Diagram 3] 1 is a graph showing the relationship between the type of refrigerant and the kinematic viscosity of refrigeration oil, and the PV value. [Figure 4] 1 is a system diagram showing a refrigeration cycle device according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, a form for carrying out the present disclosure (referred to as an embodiment) will be described with reference to the drawings. In the following description of one embodiment, other embodiments applicable to the one embodiment will also be described as appropriate. The present disclosure is not limited to the following one embodiment, and different embodiments can be combined with each other or modified as desired without significantly impairing the effects of the present disclosure. In addition, the same symbols will be used for the same members, and duplicate descriptions will be omitted. Furthermore, the same names will be used for members having the same functions. The contents shown are merely schematic, and for the sake of illustration, changes may be made from the actual configuration within a range that does not significantly impair the effects of the present disclosure, and some members may be omitted or modified between drawings. In addition, the same embodiment does not necessarily need to have all the configurations.

[0011] FIG. 1 is a cross-sectional view showing a compressor of the present disclosure. The compressor 100 is a device that compresses a gaseous refrigerant, for example, a scroll compressor. The compressor 100 includes a sealed container 1 and a compression mechanism unit 8 housed in the sealed container 1. The compression mechanism unit 8 includes a frame 3, a crankshaft 4 (drive shaft), a main bearing 5, and an orbiting bearing 6. Of these, a sliding part 9 is formed at a contact portion between the crankshaft 4 and the main bearing 5. Therefore, the compression mechanism unit 8 has the sliding part 9. Note that the sliding part 9 is not limited to between the crankshaft 4 and the main bearing 5, and may be any part that slides in the compressor 100.

[0012] The sealed container 1 is of a high-pressure chamber type. In addition to the compression mechanism 8, the sealed container 1 also accommodates an electric motor 7 and the like. A refrigerant containing 50% by mass or more of HFO refrigerant (hydrofluoroolefin refrigerant) and refrigeration oil are sealed in the sealed container 1. The refrigeration oil also exists as an oil reservoir M at the lower inside of the sealed container 1. The sealed container 1 includes a suction pipe Pa that draws in the refrigerant and a discharge pipe Pb that discharges the refrigerant compressed by the compression mechanism 8. The suction pipe Pa is connected to a suction circuit 13 (FIG. 4) described later. The discharge pipe Pb is connected to a discharge circuit 14 (FIG. 4) described later.

[0013] The compression mechanism 8 is a mechanism that compresses the refrigerant as the crankshaft 4 rotates. The compression mechanism 8 includes a fixed scroll 21 and a revolving scroll 22. The fixed scroll 21 is a fixed member that is fixed in the sealed container 1. The fixed scroll 21 includes a thick, disk-shaped base plate 21a and a spiral wrap 21b that is erected on the lower side of the base plate 21a. The revolving scroll 22 is a moving member that forms a compression chamber C between the fixed scroll 21 and the revolving scroll 22 by revolving. The revolving scroll 22 includes a disk-shaped base plate 22a, a spiral wrap 22b that is erected on the base plate 22a, and a boss portion 22c that is fitted to the upper end portion of the crankshaft 4. The revolving scroll 22 is supported by the frame 3.

[0014] The compression chamber C is formed between the wrap 21b and the wrap 22b. The compression chamber C is a space for compressing a gaseous refrigerant, and is formed on the outer line side and the inner line side of the wrap 22b. A discharge port V is provided near the center of the base plate 21a to guide the refrigerant compressed in the compression chamber C to the upper space in the sealed container 1.

[0015] The crankshaft 4 extends in the vertical direction and is made of, for example, an iron-based material (carbon steel, chrome molybdenum steel, etc.). The crankshaft 4 includes a main shaft 4a, a flange portion 4b connected to the upper side of the main shaft 4a, and an eccentric portion 4c connected to the upper side of the flange portion 4b. The main bearing 5 rotatably supports an upper portion of the crankshaft 4. The main bearing 5 is fixed to the frame 3. The main bearing 5 is, for example, a thrust bearing, and is in rotatable contact with a surface 41 of the crankshaft 4. The slewing bearing 6 rotatably supports the eccentric portion 4c.

[0016] As described above, the sliding portion 9 is formed between the main bearing 5 and the crankshaft 4. The sliding portion 9 is made of an iron-based material, and in the example of the present disclosure, the crankshaft 4 having the surface 41 and the main bearing 5 are made of an iron-based material. The iron-based material here is, for example, carbon steel or chrome molybdenum steel. These have high hardness, so by using these, it is possible to obtain a compressor 100 that has excellent wear resistance and high reliability.

[0017] 2 is a cross-sectional view showing the vicinity of the sliding part 9. A film 42 (a physical adsorption film and a chemical adsorption film described later) containing fluorine derived from the HFO refrigerant is formed on a surface 41 of the crankshaft 4 (an example of a member) of the sliding part 9, which is made of an iron-based material. The film 42 is usually formed by the rotation of the crankshaft 4 accompanying the use of the compressor 100 (FIG. 1), but may also be formed before the compressor 100 is used (for example, at the time of shipment from a factory).

[0018] As described above, the refrigerant sealed in the sealed container 1 (FIG. 1) contains 50% by mass or more of HFO refrigerant. The HFO refrigerant is an unsaturated refrigerant that contains double bonds (unsaturated bonds) in its molecules. The double bonds exhibit strong adsorptivity to the surface 41 formed of an iron-based material when the crankshaft 4 is in sliding contact with it. For this reason, the HFO refrigerant forms a physically adsorbed film (film 42) made of the refrigerant on the surface 41. As a result, the physically adsorbed film exhibits high sliding properties, improving the sliding properties of the crankshaft 4.

[0019] At least a part of the formed physically adsorbed film is decomposed by frictional heat generated by sliding. As a result, the decomposed physically adsorbed film is transformed into a chemically adsorbed film (film 42) made of a fluorine compound. The chemically adsorbed film exhibits higher sliding properties against the sliding of the crankshaft 4 than the above-mentioned physically adsorbed film. This can further improve the sliding properties of the crankshaft 4 at the sliding portion 9, and can improve the seizure resistance and reliability of the compressor 100.

[0020] FIG. 3 is a graph showing the relationship between the type of refrigerant and the dynamic viscosity of the refrigeration oil and the PV value. The graph in FIG. 3 is a relative graph in which the bearing PV value when the horizontal axis is 0.24 is set to 100%. The horizontal axis shows the actual inclination angle of the crankshaft 4 with respect to the allowable inclination angle of the crankshaft 4. It can be said that the closer the value on the horizontal axis is to 1, the greater the inclination of the crankshaft 4. Therefore, it can be said that the condition of the sliding part 9 is more severe as the value on the horizontal axis is larger. The vertical axis shows the PV value (limit PV value) of the main bearing 5 (FIG. 2). The PV value is the product of the surface pressure (p) and the surface speed (v), and is correlated with frictional heat. It can be said that the larger the PV value is, the higher the sliding property and the more excellent the durability are. Therefore, the smaller the actual inclination angle of the crankshaft 4 with respect to the allowable inclination angle of the crankshaft 4 is, the higher the PV value is.

[0021] The solid line graph (Example 1) shows a case where the refrigerant is R454C and the refrigeration oil is polyvinyl ether (kinematic viscosity at 40°C: 32 mm 2 The dashed line graph (Comparative Example 1) shows the results when R410A was used as the refrigerant and polyvinyl ether (kinematic viscosity at 40°C: 68 mm / s) was used as the refrigerant. R454C is a refrigerant containing 78.5 mass% R1234yf (HFO refrigerant) and 21.5 mass% R32 (HFC refrigerant). 2 / s) was used. R410A is a refrigerant containing 50% by mass of R125 (HFO refrigerant) and 50% by mass of R32 (HFC refrigerant).

[0022] The dashed line graph (Comparative Example 2) shows a case where the refrigerant was R448A and the refrigeration oil was polyvinyl ether (kinematic viscosity at 40°C: 32 mm 2 / s). R448A is a refrigerant containing 20 mass% R1234yf (HFO refrigerant), 7 mass% R1234ze (HFO refrigerant), 26 mass% R32 (HFO refrigerant), 26 mass% R125 (HFC refrigerant), and 21 mass% R134a (HFO refrigerant). Therefore, R448A contains 27 mass% HFO refrigerant and 73 mass% HFC refrigerant.

[0023] The above points are summarized in Table 1 below.

[0024] [Table 1]

[0025] Usually, the higher the kinetic viscosity of the refrigeration oil, the higher the sliding property. Therefore, in Comparative Example 1, which has a relatively high kinetic viscosity, a large PV value is shown, and it can be said that it has high sliding property (durability). However, the graph of Example 1 is located at approximately the same position as the graph of Comparative Example 1. Therefore, it was found that Example 1, which has a relatively low kinetic viscosity, also has high sliding property (durability). This decrease is considered to be caused by the mechanism referred to in FIG. 2 above. That is, since the kinetic viscosity of Example 1 is lower than that of Comparative Example 1, it is considered that the sliding property would also be low if the refrigerant was not taken into consideration, but it is considered that the refrigerant of Example 1 acts to compensate for the low sliding property. In other words, even if the kinetic viscosity of the refrigeration oil is low, the sliding property can be improved by using an HFO refrigerant at a predetermined ratio or more.

[0026] From another perspective, the kinetic viscosity of the refrigeration oil is the same in Example 1 and Comparative Example 2. Therefore, if only the effects caused by the refrigeration oil are considered, the positions of the graphs regarding the PV value are considered to be almost the same. However, the ratio of the HFO refrigerant in the refrigerant used is completely different. Due to such a difference in ratio, the PV value of Example 1 was increased by about 20% overall compared to the PV value of Comparative Example 2. Therefore, it was found that the sliding properties can be improved by using the HFO refrigerant within the range of the present disclosure (including 50 mass% or more of HFO refrigerant) rather than simply using an arbitrary amount of HFO refrigerant.

[0027] In addition, the refrigeration oil sealed in the sealed container 1 (FIG. 1) has a kinetic viscosity of 10 mm at 40°C. 2 / s or more 40mm 2 This allows for high sliding properties to be obtained even when using a refrigeration oil with a relatively low kinetic viscosity. 2 By setting the refrigeration oil pressure at or below 100 psi, the viscous resistance, friction resistance, etc. of the refrigeration oil can be kept low, and the efficiency of the compressor 100 can be improved.

[0028] The refrigeration oil includes at least one of polyvinyl ether and polyol ester. In particular, polyvinyl ether has high durability against air and water. For this reason, polyvinyl ether can be suitably used in, for example, a refrigeration cycle device 200 (FIG. 4) having a long piping length. On the other hand, polyol ester has lower durability against air and water than polyvinyl ether. For this reason, polyol ester can be suitably used in a refrigeration cycle device 200 (FIG. 4) having a relatively short piping length.

[0029] As described above, the refrigerant filled in the sealed container 1 (FIG. 1) contains 50% by mass or more (at least 50% by mass) of HFO refrigerant. The content of HFO refrigerant is preferably 70% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, based on the total amount of the filled refrigerant. It is preferable to use an HFO refrigerant and an HFC refrigerant in combination. By using them in combination, the functions of both the HFO refrigerant and the HFC refrigerant (e.g., sliding properties, refrigeration capacity, etc.) can be exhibited.

[0030] The HFO refrigerant includes, for example, at least one of R1234yf and R1234ze. These have high refrigeration capacity while having low global warming potential (GWP). Therefore, by including at least one of these, it is possible to obtain a high-performance compressor 100 with a small load on the global environment.

[0031] In this case, the refrigerant preferably contains R32 as at least a part other than the HFO refrigerant. R32 is widely used and has high refrigeration performance, and has a low GWP among HFC refrigerants. Therefore, it is possible to obtain a high-performance compressor 100 with a small load on the global environment.

[0032] In another embodiment, the HFO refrigerant includes a first refrigerant which is at least one of R1234yf and R1234ze, and a second refrigerant which is at least one of R1132(E) and R1123. In the entire HFO refrigerant to be charged, the first refrigerant is contained at a ratio of 50 mass% or more, and the second refrigerant is contained at a ratio of less than 50 mass%. In this way, the ratio of the first refrigerant which is at least one of R1234yf and R1234ze among the HFO refrigerants used can be increased, and the functions (stability, refrigerant capacity, efficiency, etc.) due to these can be improved.

[0033] When the second refrigerant contains R1132(E), the first refrigerant is preferably 65% ​​by mass to 100% by mass, more preferably 70% by mass to 85% by mass, and particularly preferably 70% by mass to 80% by mass. When the second refrigerant contains R1123, the first refrigerant is preferably 50% by mass to 100% by mass, more preferably 55% by mass to 80% by mass, and particularly preferably 55% by mass to 70% by mass.

[0034] FIG. 4 is a system diagram showing a refrigeration cycle device 200 of the present disclosure. In the illustrated example, the refrigeration cycle device 200 is an air conditioner, but may be, for example, a refrigerator, a showcase, or the like. The refrigeration cycle device 200 includes a compressor 100, an outdoor heat exchanger 26 (an example of a condenser or an evaporator), an electronic expansion valve 27 for heating and an electronic expansion valve 29 for cooling (both are examples of expansion mechanisms), and an indoor heat exchanger 11 (an example of an evaporator or a condenser). The compressor 100, the outdoor heat exchanger 26, the electronic expansion valves 27 and 29, and the indoor heat exchanger 11 are connected by piping (not shown), so that the refrigerant circulates through the discharge circuit 14, forming a refrigeration cycle. The refrigeration cycle is a closed circuit. A blower 25 is attached to the outdoor heat exchanger 26. A blower 10 is attached to the indoor heat exchanger 11.

[0035] The refrigeration cycle apparatus 200 further includes an oil separator 23 provided in the discharge circuit 14 of the compressor 100, and a series circuit 12 that returns refrigeration oil from the oil separator 23 to the compressor 100. The series circuit 12 is a circuit that returns refrigeration oil to an oil reservoir M (FIG. 1) formed in the lower inside part of the compressor 100. The refrigeration cycle apparatus 200 further includes a four-way switching valve 24 that switches the circulation direction of the refrigerant, a receiver 28, an accumulator 15, and a suction circuit 13.

[0036] For example, R454C, which is the refrigerant used in the above-mentioned embodiment 1, can be used in the refrigeration cycle apparatus 200. The refrigeration cycle apparatus 200 includes the compressor 100 described with reference to Figs. 1 to 3. Therefore, the sliding property at the sliding part 9 (Fig. 1) of the compressor 100 is high, and the reliability of the refrigeration cycle apparatus 200 can be improved. [Explanation of symbols]

[0037] 1. Airtight container 100 Compressor 11 Indoor heat exchanger 200 Refrigeration cycle equipment 21 Fixed Scroll 22 Swivel Scroll 26 Outdoor heat exchanger 4 Crankshaft 41 Surface 42 membrane 4a main shaft 5 Main bearing 6 Slewing bearing 8 Compression mechanism 9 Sliding part

Claims

1. A hermetic container of a high-pressure chamber type in which a refrigerant containing 50% by mass or more of a hydrofluoroolefin refrigerant and a refrigeration oil are enclosed, and a compression mechanism unit that is accommodated in the hermetic container and has a sliding portion that slides on a surface formed of an iron-based material, wherein the refrigeration oil contains at least one of a polyvinyl ether or a polyol ester refrigeration oil, The kinematic viscosity of the refrigeration oil at 40°C is 10 mm ２ / s or more and 40 mm ２ / s or less characterizing a compressor.

2. The hydrofluoroolefin refrigerant contains at least one of R1234yf or R1234ze, and the refrigerant contains R32 as at least a part other than the hydrofluoroolefin refrigerant characterizing the compressor according to Claim 1.

3. The hydrofluoroolefin refrigerant contains a first refrigerant that is at least one of R1234yf or R1234ze, and a second refrigerant that is at least one of R1132(E) or R1123, and in the whole of the hydrofluoroolefin refrigerant, the first refrigerant is contained at a ratio of 50% by mass or more, and the second refrigerant is contained at a ratio of less than 50% by mass characterizing the compressor according to Claim 1.

4. The iron-based material is carbon steel or chrome molybdenum steel characterizing the compressor according to Claim 1.

5. A hermetic container of a high-pressure chamber type in which a refrigerant containing 50% by mass or more of a hydrofluoroolefin refrigerant and a refrigeration oil are enclosed, and a compression mechanism unit that is accommodated in the hermetic container and has a sliding portion that slides on the surface of a film containing fluorine derived from the hydrofluoroolefin refrigerant formed on a surface formed of an iron-based material, wherein the refrigeration oil contains at least one of a polyvinyl ether or a polyol ester refrigeration oil, The kinematic viscosity of the refrigeration oil at 40°C is 10 mm ２ / s or more and 40 mm ２ / s or less characterizing a compressor.

6. A refrigeration cycle device including a compressor, a condenser, an expansion mechanism, and an evaporator, wherein the compressor is a hermetic container of a high-pressure chamber type in which a refrigerant containing 50% by mass or more of a hydrofluoroolefin refrigerant and a refrigeration oil are enclosed, and a compression mechanism unit that is accommodated in the hermetic container and has a sliding portion that slides on a surface formed of an iron-based material, wherein the refrigeration oil contains at least one of a polyvinyl ether or a polyol ester refrigeration oil, The kinematic viscosity of the refrigeration oil at 40 °C is 10 mm ２ / s or more and 40 mm ２ / s or less characterizing the refrigeration cycle device.

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