Heat pump apparatus

Abstract

To obtain long-term reliability of a heat pump apparatus by using an insulating material that is less liable to be hydrolyzed even when a refrigerating machine oil having high hygroscopicity and a high water content in oil is used, an electric motor of a compressor includes: a stator fixed to a sealed container with a winding being wound around the stator through intermediation of an insulating material; and a rotator surrounded by the stator. The insulating material includes wholly aromatic liquid crystal polyester (LCP) containing, as an essential component, p-hydroxybenzoic acid (PHB) as a monomer and having a main chain of a molecule formed by linking p-hydroxybenzoic acid and, as another monomer, only a monomer having a benzene ring, through an ester bond. A saturated water amount of the refrigerating machine oil is 1% or less at 40 degrees Celsius and a relative humidity of 80%.

1 . A heat pump apparatus, comprising:
 a compressor;   a condenser;   an expansion mechanism; and   an evaporator,
 the compressor, the condenser, the expansion mechanism, and the evaporator being configured to perform a refrigeration cycle, 
 the heat pump apparatus being configured to perform heat transfer in the condenser or the evaporator, 
   wherein the compressor includes
 a sealed container, 
 a compression mechanism mounted inside the sealed container, and 
 an electric motor configured to rotate and drive the compression mechanism, 
 the compression mechanism being configured to compress refrigerant, and to be lubricated by a refrigerating machine oil, 
   wherein the electric motor includes
 a stator fixed to the sealed container with a winding being wound around the stator through intermediation of an insulating material, and 
 a rotator surrounded by the stator, 
   wherein the insulating material includes a liquid crystal polymer having a main chain of a molecule obtained by ester bonding, the liquid crystal polymer being obtained by polycondensation of a total of two or more kinds of monomers, the monomers containing, as an essential component, p-hydroxybenzoic acid (PHB) as a monomer component having an ester bond and containing, as an additive component, one or more kinds of a following five kinds: 4,4′-biphenol (BP), hydroquinone (HQ), terephthalic acid (TPA), isophthalic acid (IPA), and 6-hydroxy-2-naphthoic acid (BON6), and   wherein a saturated water amount of the refrigerating machine oil is 0.5% or more and 1% or less at 40 degrees Celsius and a relative humidity of 80%.   
     
     
         2 . The heat pump apparatus of  claim 1 , wherein a liquid crystal polymer serving as the insulating material has a latent heat of crystallization measured by a differential scanning calorimeter (DSC) of 10 J/g or less. 
     
     
         3 . (canceled) 
     
     
         4 . The heat pump apparatus of  claim 1 , wherein the refrigerating machine oil includes a single substance or a combination of substances including at least one kind of an ester-based mineral oil, an ether-based mineral oil, a glycol-based mineral oil, an alkyl benzene-based mineral oil, a poly-α-olefin-based mineral oil, a polyvinyl ether-based mineral oil, a fluorine-based mineral oil, a naphthene-based mineral oil, and a paraffin-based mineral oil. 
     
     
         5 . The heat pump apparatus of  claim 1 , wherein the refrigerant includes a single substance or a combination of substances including at least one kind of difluoromethane (HFC-32), 1,1,1,2,2-pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 2,2-dichloro-1,1,1-trifluoroethane (HFC-123), trifluoromethane (HFC-23), 1,1-difluoroethane (HFC-152a), 1,1,2 trifluoroethylene (R1123), trans-1,2-difluoroethylene (R1132(E)), cis-1,2 difluoroethylene (R1132(Z)), 1,1-difluoroethylene (R1132a), 2,3,3,3-tetrafluoro-l-propane (HFO-1234yf), chlorodifluoromethane (HFC-22), carbon dioxide, ammonia, dimethyl ether, propane (R-290), isobutane (R-600a), and butane (R-600). 
     
     
         6 . A heat pump apparatus, comprising:
 a compressor;   a condenser;   an expansion mechanism; and   an evaporator,
 the compressor, the condenser, the expansion mechanism, and the evaporator being configured to perform a refrigeration cycle, 
 the heat pump apparatus being configured to perform heat transfer in the condenser or the evaporator, 
   wherein the compressor includes
 a sealed container, 
 a compression mechanism mounted inside the sealed container, and 
 an electric motor configured to rotate and drive the compression mechanism, 
 the compression mechanism being configured to compress refrigerant, and to be lubricated by a refrigerating machine oil, 
   wherein the electric motor includes
 a stator fixed to the sealed container with a winding being wound around the stator through intermediation of an insulating material, and 
 a rotator surrounded by the stator, 
   wherein the insulating material includes a liquid crystal polymer having a main chain of a molecule obtained by ester bonding, the liquid crystal polymer being obtained by polycondensation of monomers, the monomers containing, as an essential component, p-hydroxybenzoic acid (PHB) as a monomer component having an ester bond and containing, as an additive component, a following five kinds: 4,4′-biphenol (BP), hydroquinone (HQ), terephthalic acid (TPA), isophthalic acid (IPA), and 6-hydroxy-2-naphthoic acid (BON6), and   wherein a saturated water amount of the refrigerating machine oil is 0.5% or more and 1% or less at 40 degrees Celsius and a relative humidity of 80%.   
     
     
         7 . The heat pump apparatus of  claim 6 , wherein a liquid crystal polymer serving as the insulating material has a latent heat of crystallization measured by a differential scanning calorimeter (DSC) of 10 J/g or less. 
     
     
         8 . The heat pump apparatus of  claim 6 , wherein the refrigerating machine oil includes a single substance or a combination of substances including at least one kind of an ester-based mineral oil, an ether-based mineral oil, a glycol-based mineral oil, an alkyl benzene-based mineral oil, a poly-α-olefin-based mineral oil, a polyvinyl ether-based mineral oil, a fluorine-based mineral oil, a naphthene-based mineral oil, and a paraffin-based mineral oil. 
     
     
         9 . The heat pump apparatus of  claim 6 , wherein the refrigerant includes a single substance or a combination of substances including at least one kind of difluoromethane (HFC-32), 1,1,1,2,2-pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 2,2-dichloro-1,1,1-trifluoroethane (HFC-123), trifluoromethane (HFC-23), 1,1-difluoroethane (HFC-152a), 1,1,2 trifluoroethylene (R1123), trans-1,2-difluoroethylene (R1132(E)), cis-1,2 difluoroethylene (R1132(Z)), 1,1-difluoroethylene (R1132a), 2,3,3,3-tetrafluoro-1-propane (HFO-1234yf), chlorodifluoromethane (HFC-22), carbon dioxide, ammonia, dimethyl ether, propane (R-290), isobutane (R-600a), and butane (R-600).