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EP-4484853-B1 - REFRIGERATION CYCLE DEVICE

EP4484853B1EP 4484853 B1EP4484853 B1EP 4484853B1EP-4484853-B1

Inventors

  • KAWAE, Arisa
  • MATSUURA, HIDEKI
  • TANAKA, MASARU
  • TERAI, HARUKA

Dates

Publication Date
20260506
Application Date
20230220

Claims (6)

  1. A refrigeration cycle apparatus (1) comprising a refrigerant circuit (10) in which a compressor (11), a heat radiator (13), an expansion mechanism (9), and a heat absorber (18) are sequentially connected and propane as a refrigerant is circulated, wherein the compressor includes a sliding portion including a bearing (26, 32, 91) or an Oldham ring (25), at least one of two members slidable with each other in the sliding portion is formed of aluminum or aluminum alloy, , and a refrigerating machine oil used in the compressor has a refrigerant solubility of 30 wt% or less at a pressure of 1.9 MPa and at a temperature of 60°C.
  2. The refrigeration cycle apparatus according to claim 1, wherein the refrigerating machine oil used in the compressor has a refrigerant solubility of 5 wt% or more and 30 wt% or less at a pressure of 1.9 MPa and at a temperature of 60°C.
  3. The refrigeration cycle apparatus according to claim 1 or 2, wherein the refrigerating machine oil is a polyalkylene glycol having a hydroxy group ratio relative to all end groups of 40 mol% or more and 90 mol% or less.
  4. The refrigeration cycle apparatus according to claim 3, wherein the refrigerating machine oil is a polyalkylene glycol having a hydroxy group ratio relative to all end groups of more than 50 mol% and 90 mol% or less.
  5. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the aluminum alloy contains 12.6 wt% to 18 wt% of silicon.
  6. The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein one of the two members is formed of aluminum or aluminum alloy and another one is formed of aluminum.

Description

TECHNICAL FIELD The present invention relates to a refrigeration cycle apparatus. BACKGROUND ART Hitherto, compressors that compress hydrocarbon-type refrigerants such as propane have been used. For example, US 2019/0383289 A1 discloses a compressor that uses propane as a refrigerant and includes an Oldham ring coated with resin in order to suppress wear. SUMMARY OF THE INVENTION <Technical Problem> Hydrocarbon-type refrigerants tend to dissolve in refrigerating machine oils, which may result in a decrease in the viscosity of the refrigerating machine oils and cause excessive wear of the sliding portions inside the compressors. In the case of, as described in US 2019/0383289 A1, coating sliding portions with resin or the like in order to suppress wear, slidability of the sliding portions may degrade. Further examples of previously known refrigeration cycle apparatuses are derivable from JP H11 302675 A, JP 2005 264 931 A, JP 2008 308610 A and JP 2012 31239 A. <Solution to Problem> The above object is resolved by means of a refrigeration cycle apparatus according to independent claim 1. Distinct embodiments are derivable from the dependent claims. A refrigeration cycle apparatus according to a first embodiment includes a refrigerant circuit in which a compressor, a heat radiator, an expansion mechanism, and a heat absorber are sequentially connected and a refrigerant is circulated. The compressor includes a sliding portion including a bearing or an Oldham ring. At least one of two members slidable with each other in the sliding portion is formed of aluminum or aluminum alloy. The refrigerant circulating through the refrigerant circuit is propane. A refrigerating machine oil used in the compressor has a refrigerant solubility of 30 wt% or less at a pressure of 1.9 MPa and at a temperature of 60°C. In this refrigeration cycle apparatus in which the refrigerating machine oil employed has an oil concentration of the predetermined value or more at the predetermined temperature and at the predetermined pressure, the oil concentration being the concentration of the refrigerating machine oil in a mixture of the refrigerant and the refrigerating machine oil, the decrease in the viscosity of the refrigerating machine oil is suppressed and abrasion loss of the sliding portion in the compressor is reduced. A refrigeration cycle apparatus according to a second embodiment is the refrigeration cycle apparatus according to the first embodiment, wherein the refrigerating machine oil used in the compressor has a refrigerant solubility of 5 wt% or more and 30 wt% or less at a pressure of 1.9 MPa and at a temperature of 60°C. A refrigeration cycle apparatus according to a third embodiment is the refrigeration cycle apparatus according to the first embodiment or the second embodiment, wherein the refrigerating machine oil is a polyalkylene glycol having a hydroxy group ratio relative to all end groups of 40 mol% or more and 90 mol% or less. In this refrigeration cycle apparatus in which the refrigerating machine oil employed has an oil concentration within the predetermined range, abrasion loss of the sliding portion in the compressor is reduced and occurrence of the phenomenon in which the refrigerating machine oil is less likely to return to the compressor is suppressed. A refrigeration cycle apparatus according to a fourth embodiment is the refrigeration cycle apparatus according to the third embodiment, wherein the refrigerating machine oil is a polyalkylene glycol having a hydroxy group ratio relative to all end groups of more than 50 mol% and 90 mol% or less. In this refrigeration cycle apparatus in which the refrigerating machine oil employed has an oil concentration within the predetermined range, abrasion loss of the sliding portion in the compressor is reduced and occurrence of the phenomenon in which the refrigerating machine oil is less likely to return to the compressor is suppressed. A refrigeration cycle apparatus according to a fifth embodiment is the refrigeration cycle apparatus according to any one of the first to fourth embodiments, wherein the aluminum alloy contains 12.6 wt% to 18 wt% of silicon. A refrigeration cycle apparatus according to a sixth embodiment is the refrigeration cycle apparatus according to any one of the first to fifth embodiments, wherein one of the two members slidable with each other in the sliding portion is formed of aluminum or aluminum alloy and another one is formed of iron or aluminum. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration view of an air conditioning apparatus 1.FIG. 2 is a schematic sectional view of a compressor 11.FIG. 3 is an enlarged view of a region including a floating member 30 of the compressor 11.FIG. 4 is a graph of relations among the hydroxy group content of a refrigerating machine oil, oil concentration, and abrasion loss of a sliding portion in a compressor 11. DESCRIPTION OF EMBODIMENTS (1) Overall configuration An air conditioning