U.S. patent application number 13/193655 was filed with the patent office on 2012-02-02 for compressor for refrigeration and air-conditioning and refrigerating and air-conditioning apparatus.
Invention is credited to Kuninari Araki, Ryo OTA, Tsuneji Sugano.
Application Number | 20120024007 13/193655 |
Document ID | / |
Family ID | 45525342 |
Filed Date | 2012-02-02 |
United States Patent
Application |
20120024007 |
Kind Code |
A1 |
OTA; Ryo ; et al. |
February 2, 2012 |
COMPRESSOR FOR REFRIGERATION AND AIR-CONDITIONING AND REFRIGERATING
AND AIR-CONDITIONING APPARATUS
Abstract
A refrigerating machine oil including a refrigerating machine
oil basis such as polyol ester oil and an additive polyol ester oil
is mixed to a refrigerant including 2,3,3,3-tetrafluoropropene,
1,3,3,3-tetrafluoropropene or the like. A compressor for
refrigeration and air-conditioning including the mixture charged
therein is used. The composition of the additive polyol ester oil
is 1 to 30 wt %. The wear resistance of the compressor is improved,
and the efficiency of a refrigerating and air-conditioning
apparatus using the compressor is enhanced.
Inventors: |
OTA; Ryo; (Hitachi, JP)
; Sugano; Tsuneji; (Nikko, JP) ; Araki;
Kuninari; (Itakura, JP) |
Family ID: |
45525342 |
Appl. No.: |
13/193655 |
Filed: |
July 29, 2011 |
Current U.S.
Class: |
62/468 |
Current CPC
Class: |
C09K 5/045 20130101;
C10M 2205/0285 20130101; C10M 2203/1065 20130101; F25B 1/04
20130101; C10M 2207/283 20130101; C10N 2040/30 20130101; C10M
2207/2835 20130101; C10M 2209/105 20130101; C10M 2209/043 20130101;
C09K 2205/126 20130101; C10N 2020/103 20200501; C10N 2030/06
20130101; C10N 2020/101 20200501; C10N 2020/02 20130101; C10M
171/008 20130101; C09K 5/042 20130101; C09K 2205/24 20130101; C10M
2209/105 20130101; C10M 2209/108 20130101 |
Class at
Publication: |
62/468 |
International
Class: |
F25B 41/00 20060101
F25B041/00; F25B 1/00 20060101 F25B001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 29, 2010 |
JP |
2010-169889 |
Claims
1. A compressor for refrigeration and air-conditioning, comprising
a mixture charged therein, the mixture comprising: a charged
refrigerant which is a refrigerant including
2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene or
difluoromethane, or R410A; and a refrigerating machine oil
comprising a refrigerating machine oil basis including at least one
base oil selected from the group consisting of polyol ester oils
expressed by the following chemical formulae (1) and (2) (where in
the formulae, R.sub.1 represents an alkyl group having 5 to 9
carbon atoms), and an additive polyol ester oil expressed by the
following chemical formula (3) (where in the formula, R.sub.2
represents an alkyl group having 7 to 9 carbon atoms), a
composition of the additive polyol ester oil being 1 to 30 wt %.
##STR00002##
2. The compressor according to claim 1, wherein a kinetic viscosity
at 40.degree. C. of the refrigerating machine oil basis is within
the range of 25 to 120 mm.sup.2/s, and the kinetic viscosity at
40.degree. C. of the additive polyol ester oil is 180 mm.sup.2/s or
more.
3. A refrigerating and air-conditioning apparatus comprising the
compressor according to claim 1, a heat exchanger for dissipating
the heat of the charged refrigerant discharged from the compressor,
a pressure reducing unit for reducing the pressure of the charged
refrigerant flowed from the heat exchanger, and a heat exchanger
for heating the charged refrigerant reduced in pressure in the
pressure reducing unit.
4. The refrigerating and air-conditioning apparatus according to
claim 3, wherein an adsorption capability of the additive polyol
ester oil to an iron-based material is two or more times higher
than that of the refrigerating machine oil basis.
5. A compressor for refrigeration and air-conditioning, comprising
a mixture charged therein, the mixture comprising: a charged
refrigerant which is a refrigerant including
2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene, propane,
propylene or fluoroethane; and a refrigerating machine oil
comprising a refrigerating machine oil basis including mineral oils
or polyvinyl ether oils, or at least one base oil selected from the
group consisting of polyol ester oils expressedby the following
chemical formulae (1) and (2) (where in the formulae, R.sub.1
represents an alkyl group having 5 to 9 carbon atoms), the
refrigerating machine oil basis having a lower critical solution
temperature of -30.degree. C. or less, and an additive polyol ester
oil expressed by the following chemical formula (3) (where in the
formula, R.sub.2 represents an alkyl group having 7 to 9 carbon
atoms), a composition of the additive polyol ester oil being 1 to
30 wt %. ##STR00003##
6. The compressor according to claim 5, wherein a kinetic viscosity
at 40.degree. C. of the refrigerating machine oil basis is within
the range of 25 to 120 mm.sup.2/s, and the kinetic viscosity at
40.degree. C. of the additive polyol ester oil is 180 mm.sup.2/s or
more.
7. A refrigerating and air-conditioning apparatus comprising the
compressor according to claim 5, a heat exchanger for dissipating
the heat of the charged refrigerant discharged from the compressor,
a pressure reducing unit for reducing the pressure of the charged
refrigerant flowed from the heat exchanger, and a heat exchanger
for heating the charged refrigerant reduced in pressure in the
pressure reducing unit.
8. The refrigerating and air-conditioning apparatus according to
claim 7, wherein an adsorption capability of the additive polyol
ester oil to an iron-based material is two or more times higher
than that of the refrigerating machine oil basis.
9. A compressor for refrigeration and air-conditioning comprising a
mixture charged therein, the mixture comprising: a refrigerant for
refrigeration and air-conditioning which is a refrigerant with a
global warming potential of 1000 or less, or R410A; and a
refrigerating machine oil comprising a refrigerating machine oil
basis including at least one base oil selected from the group
consisting of polyol ester oils expressed by the following chemical
formulae (1) and (2) (where in the formulae, R.sub.1 represents an
alkyl group having 5 to 9 carbon atoms), the refrigerating machine
oil basis having a kinetic viscosity at 40.degree. C. of 25 to 120
mm.sup.2/s, and an additive polyol ester oil expressed by the
following chemical formula (3) (where in the formula, R.sub.2
represents an alkyl group having 7 to 9 carbon atoms), a
composition of the additive polyol ester oil being 1 to 30 wt %.
##STR00004##
10. A refrigerating and air-conditioning apparatus comprising the
compressor according to claim 9, a heat exchanger for dissipating
the heat of the refrigerant discharged from the compressor, a
pressure reducing unit for reducing the pressure of the refrigerant
flowed from the heat exchanger, and a heat exchanger for heating
the refrigerant reduced in pressure in the pressure reducing
unit.
11. The refrigerating and air-conditioning apparatus according to
claim 10, wherein an adsorption capability of the additive polyol
ester oil to an iron-based material is two or more times higher
than that of the refrigerating machine oil basis.
Description
CLAIM OF PRIORITY
[0001] The present application claims priority from Japanese Patent
application serial No. 2010-169889, filed on Jul. 29, 2010, the
content of which is hereby incorporated by reference into this
application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a compressor for
refrigeration and air-conditioning and a refrigerating and
air-conditioning apparatus using a heat pump cycle.
[0004] 2. Description of Related Art
[0005] As the global environment measures in a refrigerating and
air-conditioning system field, mention may be made of substitution
of CFC (Chlorofluorocarbons) and HCFC (Hydrochlorofluorocarbons)
used as refrigerants or heat insulating materials as ozone
depleting substances, and substitution of HFC (Hydrofluorocarbons)
used for enhancement of efficiency or refrigerants as global
warming countermeasures. These have been positively pursued.
[0006] For substitutes of CFC and HCFC which are ozone depleting
substances, selection of refrigerants and heat insulating
materials, and development of equipment have been pursued with the
aims of preventing the depletion of the ozone layer, providing low
toxicity and flammability, and being capable of ensuring
efficiency. As a result, for the heat insulating materials for
refrigerators, substitution of the blowing agent from CFC11 to
HCFC141b and cyclopentane has been done in this order. Currently,
there has been made a shift to use in combination with a vacuum
heat insulating material.
[0007] The refrigerant was sequentially changed from CFC12C to
HFC134a (GWP (Global Warming Potential)=1430) in a refrigerator or
a car air conditioner, and was changed from HCFC22 to R410A
(HFC32/HFC125 (50/50 wt %) mixture: GWP=2088) in a room air
conditioner or a package air conditioner.
[0008] However, in the third session of the Conference of Parties
to the United Nations Framework Convention on Climate Change (COP3)
held in Kyoto in 1997), the HFC emission was to be converted to the
CO.sub.2 equivalent emission as a greenhouse gas, to be subject to
the regulation. Accordingly, reduction of HFC has come to be
pursued.
[0009] Thus, in home refrigerators, the amount of a refrigerant
charged therein is small, and flammable refrigerants are also
judged as usable from the viewpoint of manufacturing. Accordingly,
HFC134a was substituted with flammable R600a (isobutane: GWP=3).
Further, attention has currently also been directed to HFC134a for
the car air conditioners, and R410A for room air conditioners and
package air conditioners due to a groundswell of popular opinion.
Whereas, in industrial refrigerators, the amount of R600a charged
is large. Thus, HFC134a is used even at present because of a
concern about the flammability.
[0010] In actuality, by the Home Appliance Recycling Law (Law for
Recycling of Specified kinds of Home Appliances) enforced in 2001,
and the End-of-life Vehicle Recycling Law (Act on Recycling, etc.
of End-of-life Vehicles) enforced in 2003, recycling of equipment
is obliged. Thus, HFC and the like used as refrigerants are
recovered and treated. However, in EU (the European Union), in the
2006 Directive (the Directive 2006/40/EC), use of refrigerants with
a GWP of more than 150 as the refrigerants for use in car air
conditioners was prohibited from those shipped in January, 2011. In
response to this, the car air conditioner industry shows various
movements. Concerns are rising that R410A will be also regulated
sometime for room air conditioners. There may be review of
regulations including those on fixed air conditioners in 2011 based
on the EU Directive. This accelerates the study on alternative
refrigerants.
[0011] For the alternative refrigerants, 2,3,3,3-tetrafluoropropene
(HFO1234yf (Hydrofluoroolefine)) (GWP=4) and
1,3,3,3-tetrafluoropropene (HFO1234ze) (GWP=10) become candidates
alone or in mixture thereof because they have the same thermal
physical properties as that of HFC134a, and each have a low GWP, a
low toxicity, a low flammability and the like. The refrigerant to
be mixed with 2,3,3,3-tetrafluoropropene is mainly difluoromethane
(HFC32).
[0012] Further, it can be also considered that HFC134a or HFC125 is
mixed according to GWP allowable for low flammability. As other
refrigerants, mention may be made of hydrocarbons such as propane
and propylene, and low GWP hydrofluorocarbons such as fluoroethane
(HFC161), difluoroethane (HFC152a), and difluoromethane
(HFC32).
[0013] On the other hand, a refrigerating machine oil is used for a
closed electric compressor, and plays roles of lubrication,
sealing, cooling and the like of the sliding part.
[0014] For air conditioners, APF (Annual Performance Factor) is
adopted as an index indicating the energy saving performance in
accordance with the actual usage by the Energy Saving Law (Law
concerning the Rational Use of Energy) revised from 2006. Also for
compressors, further saving in energy and higher efficiency are
required. Thus, the use conditions become severe. This results in a
demand for a refrigerating machine oil with good lubricity in view
of ensuring the reliability.
[0015] As refrigerating machine oils for use in compressors using
each single refrigerant of 2,3,3,3-tetrafluoropropene (HFO1234yf)
and 1,3,3,3-tetrafluoropropene (HFO1234ze), or a mixed refrigerant
including the refrigerants, there are disclosed polyalkylene glycol
oils, mineral oils, poly-alpha-olefin oils, and alkylbenzene oils
from the foregoing circumstances (e.g., Japanese Translation of PCT
Application No. 2009-540170 (Patent Document 1)).
[0016] JP-A No. S58-93796 (Patent Document 2) discloses a
refrigerating machine oil composition in which a fraction with a
boiling point of 50 to 250.degree. C. under ordinary pressure, and
a viscosity of 5 centistokes/40.degree. C. or less is contained in
a refrigerating machine oil including at least one of paraffin type
refrigerating machine oils, naphthene type refrigerating machine
oils and synthetic refrigerating machine oils.
[0017] Other than these, Japanese Translation of PCT Application
No. 2007-532767 (Patent Document 3), Japanese Translation of PCT
Application No. 2007-538115 (Patent Document 4), Japanese
Translation of PCT Application No. 2008-504374 (Patent Document 5),
Japanese Translation of PCT Application No. 2008-505989 (Patent
Document 6), Japanese Translation of PCT Application No.
2008-506793 (Patent Document 7), Japanese Translation of PCT
Application No. 2008-524433 (Patent Document 8) and Japanese
Translation of PCT Application No. 2008-239814 (Patent Document 9)
disclose azeotrope-like compositions including HFO-1234yf,
HFO-1225yeZ, trans-1,3,3,3-pentafluoropropane (transHFO-1234ze),
1,1-difluoroethane (HFC-152a), 1,1,1,2,3,3,3-heptafluoropropane
(HFC-227ea), 1,1,1,2-tetrafluoroethane (HFC-134a),
1,1,1,2,2-pentafluoroethane (HFC-125) and the like, and lubricants
such as mineral oils (including paraffin oils or naphthene oils),
silicone oil, polyalkylbenzene, polyol ester, polyalkylene glycol,
polyalkylene glycol ester, polyvinyl ether, poly(alpha-olefin) and
halocarbon oil.
SUMMARY OF THE INVENTION
[0018] 2,3,3,3-Tetrafluoropropene (HFO1234yf) and
1,3,3,3-tetrafluoropropene (HFO1234ze) are lower-pressure
refrigerants than R410A. Accordingly, it is essential to increase
the volume of displacement of the compressor and increase the
rotation speed thereof for gaining the circulating refrigerant
amount. For this reason, in the case of the refrigerating machine
oils, there remains a problem on the wear resistance in sliding
parts such as compressor bearings.
[0019] Further, refrigerants such as HFO1234yf, HFO1234ze, propane,
propylene and fluoroethane each have a very high miscibility with
the refrigerating machine oils, and the amount of each refrigerant
dissolved in the compressor is large. This results in reduction of
the refrigerant dissolved viscosity in the refrigerating machine
oil. This unfavorably causes reduction of the sealing property of
the compression part, and further an increase in wear amount of the
sliding part.
[0020] For the foregoing reasons, a refrigerating machine oil
capable of ensuring both the improvement of efficiency and the wear
resistance of the system is preferably used for a refrigerating and
air-conditioning apparatus.
[0021] It is an object of the present invention to improve the wear
resistance of a compressor for refrigeration and air-conditioning
using refrigerants for refrigeration and air-conditioning such as
refrigerants including 2,3,3,3-tetrafluoropropene,
1,3,3,3-tetrafluoropropene and the like, or hydrocarbons such as
propane and propylene, fluoroethane (HFC161), difluoroethane
(HFC152a), difluoromethane (HFC32) and R410A as refrigerants, and
to implement a higher efficiency of the refrigerating and
air-conditioning system using the compressor.
[0022] The compressor for refrigeration and air-conditioning of the
present invention includes a mixture charged therein. The mixture
includes a refrigerant including 2,3,3,3-tetrafluoropropene,
1,3,3,3-tetrafluoropropene or the like; and a refrigerating machine
oil including a refrigerating machine oil basis such as polyol
ester oil, and an additive polyol ester oil. The compressor is
characterized in that the composition of the additive polyol ester
oil is 1 to 30 wt %.
[0023] In accordance with the present invention, it is possible to
obtain a compressor which has achieved both the improvement of the
performances of the compressor and the wear resistance thereof
without using a phosphorus-containing extreme pressure agent
detrimental to environment as the additive of the refrigerating
machine oil.
[0024] Further, in accordance with the present invention, it is
possible to obtain an environmentally friendly refrigerating and
air-conditioning apparatus capable of achieving both the
improvement of performances and the long-term reliability of the
refrigerating and air-conditioning apparatus without using the
phosphorus-containing extreme pressure agent as the additive of the
refrigerating machine oil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a schematic block diagram showing a room air
conditioner.
[0026] FIG. 2 is a cross-sectional view showing a scroll type
closed compressor for a room air conditioner.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Below, a description will be given to a compressor for
refrigeration and air-conditioning in accordance with an embodiment
of the present invention, and a refrigerating and air-conditioning
apparatus using the same.
[0028] The compressor for refrigeration and air-conditioning
includes a mixture therein. The mixture includes a charged
refrigerant which is a refrigerant including
2,3,3,3-tetrafluoropropene, 1,3,3,3-tetrafluoropropene or
difluoromethane, or R410A; and a refrigerating machine oil
including a refrigerating machine oil basis including at least one
base oil selected from the group consisting of polyol ester oils
expressed by the following chemical formulae (1) and (2) (where in
the formulae, R.sub.1 represents an alkyl group having 5 to 9
carbon atoms), and an additive polyol ester oil expressed by the
following chemical formula (3) (where in the formula, R.sub.2
represents an alkyl group having 7 to 9 carbon atoms).
##STR00001##
[0029] The compressor for refrigeration and air-conditioning is
charged with a mixture of a charged refrigerant which is a
refrigerant including 2,3,3,3-tetrafluoropropene,
1,3,3,3-tetrafluoropropene, propane, propylene or fluoroethane; and
a refrigerating machine oil basis including at least one base oil
selected from the group consisting of mineral oils, polyvinyl ether
oils, or polyol ester oils expressed by the chemical formulae (1)
and (2) (where in the formulae, R.sub.1 represents an alkyl group
having 5 to 9 carbon atoms), the refrigerating machine oil basis
having a lower critical solution temperature of -30.degree. C. or
less; and an additive polyol ester oil expressed by the chemical
formula (3) (where in the formula, R.sub.2 represents an alkyl
group having 7 to 9 carbon atoms). Then, the composition of the
additive polyol ester oil is 1 to 30 wt %.
[0030] In the compressor for refrigeration and air-conditioning, it
is desirable that a kinetic viscosity at 40.degree. C. of the
refrigerating machine oil basis is within the range of 25 to 120
mm.sup.2/s, and the kinetic viscosity at 40.degree. C. of the
additive polyol ester oil is 180 mm.sup.2/s or more.
[0031] The refrigerating and air-conditioning apparatus includes
the compressor for refrigeration and air-conditioning, a heat
exchanger for dissipating the heat of the charged refrigerant
discharged from the compressor for refrigeration and
air-conditioning, a pressure reducing unit for reducing the
pressure of the charged refrigerant flowed from the heat exchanger,
and a heat exchanger for heating the charged refrigerant reduced in
pressure in the pressure reducing unit.
[0032] In the refrigerating and air-conditioning apparatus, it is
desirable that a kinetic viscosity at 40.degree. C. of the
refrigerating machine oil basis is 25 to 120 mm.sup.2/s, and the
adsorption capability of the additive polyol ester oil to an
iron-based material is two or more times higher than that of the
refrigerating machine oil basis.
[0033] The compressor for refrigeration and air-conditioning is
charged with a mixture including a refrigerant for refrigeration
and air-conditioning which is a refrigerant having a global warming
potential of 1000 or less, or R410A; and a refrigerating machine
oil including a refrigerating machine oil basis including at least
one base oil selected from the group consisting of polyol ester
oils expressed by the following chemical formulae (1) and (2)
(where in the formulae, R.sub.1 represents an alkyl group having 5
to 9 carbon atoms), the refrigerating machine oil basis having a
kinetic viscosity at 40.degree. C. of 25 to 120 mm.sup.2/s; and an
additive polyol ester oil expressed by the following chemical
formula (3) (where in the formula, R.sub.2 represents an alkyl
group having 7 to 9 carbon atoms).
[0034] The composition of the additive polyol ester oil is
desirably 1 to 30 wt %.
[0035] The compressor for refrigeration and air-conditioning
includes a scroll or rotary closed compressor including a motor
therein, and in addition, a twin rotary compressor, a two-stage
compression rotary compressor, and a swing compressor including a
roller and a vane integrated with each other. Desirably, the
kinetic viscosity at 40.degree. C. of the refrigerating machine oil
basis is 25 mm.sup.2/s to 120 mm.sup.2/s or less, and the kinetic
viscosity at 40.degree. C. of the additive polyol ester oil is 180
mm.sup.2/s or more.
[0036] The compressor for refrigeration and air-conditioning
includes a sliding part formed of an iron-based material. The
contact surface pressure in the sliding part is 10 MPa or more.
[0037] In the compressor for refrigeration and air-conditioning,
the additive polyol ester oil has an adsorption capability to the
iron-based material two or more times higher than that of the
refrigerating machine oil basis. Further, the adsorption capability
of the additive polyol ester oil to the iron-based material is
desirably two times higher, and further desirably 4 times
higher.
[0038] The refrigerating and air-conditioning apparatus uses the
scroll or rotary compressor.
[0039] Below, the present invention will be described in details by
way of Examples.
[0040] Examples each disclose a compressor using
2,3,3,3-tetrafluoropropene or 1,3,3,3-tetrafluoropropene, or a
mixed refrigerant including these, or propane, propylene,
fluoroethane, difluoromethane, or R410A as a refrigerant, and a
refrigerating and air-conditioning apparatus using the
compressor.
[0041] In this specification, the refrigerants for refrigeration
and air-conditioning include refrigerants with a GWP of 1000 or
less such as 2,3,3,3-tetrafluoropropene or
1,3,3,3-tetrafluoropropene, or a mixed refrigerant including these,
or propane, propylene, fluoroethane and difluoromethane, and
R410A.
[0042] The refrigerating machine oils of Examples include additive
polyol ester oils with an extremely higher adsorption capability to
an iron-based material than that of the base oil.
[0043] As base oils with a lower adsorption capability than that of
the additive polyol ester oil, mention may be made of mineral oil,
polyvinyl ether oil, and polyol ester oil having an ester group in
the molecular structure.
[0044] As the mineral oils, there can be used naphthene type
mineral oils and paraffin type mineral oils. As these mineral oils,
mention may be made of, for example, burning oils obtained by
refining distillate oils obtained by subjecting paraffinic crudes,
intermediate base crudes, or naphthenic crudes to atmospheric
distillation, or by subjecting atmospherically distilled residual
oils to vacuum distillation according to the ordinary methods,
deeply dewaxed oils obtained by further performing a deep dewaxing
treatment after refining, and hydrogen-treated oils obtained by a
hydrogen treatment. The refining methods at the steps have no
particular restriction, and various methods are used.
[0045] The polyol ester oil is obtained from the condensation
reaction between polyhydric alcohol and monohydric fatty acid.
[0046] The polyol ester oils are preferably of hindered type
excellent in thermal stability. Preferred examples of polyhydric
alcohols include neopentyl glycol, trimethylolpropane and
pentaerythritol.
[0047] Monohydric fatty acids include n-pentanoic acid, n-hexanoic
acid, n-heptanoic acid, n-octanoic acid, 2-methylbutanoic acid,
2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic
acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid and the like.
These are used alone, or in mixture of two or more thereof.
[0048] The additive polyol ester oils with a high adsorption
capability to an iron-based material are desirably polyol ester
oils including ester groups in a large amount in the molecular
structure. Mention may be made of dipentaerythritol of a hindered
type synthesized from polyhydric alcohol and monohydric fatty
acid.
[0049] Monohydric fatty acids include n-pentanoic acid, n-hexanoic
acid, n-heptanoic acid, n-octanoic acid, 2-methylbutanoic acid,
2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylhexanoic
acid, isooctanoic acid, 3,5,5-trimethylhexanoic acid and the like.
These are used alone, or in mixture of two or more thereof.
[0050] The viscosity grade of each refrigerating machine oil for
use in the air-conditioning apparatuses and the refrigerating
machines of Examples varies according to the type of the
compressor. However, the kinetic viscosity at 40.degree. C. is
preferably within the range of 46 to 120 mm.sup.2/s in a scroll
compressor. Whereas, the kinetic viscosity at 40.degree. C. is
preferably within the range of 25 to 70 mm.sup.2/s in a rotary
compressor.
[0051] The heat resistance class of electrical insulation is
specified according to the heat resistance class of electrical
insulation and the heat resistance evaluation JEC-6147 (The
Institute of Electrical Engineers of Japan, Japanese
Electrotechnical Committee Standard). The insulation materials
adopted for compressors for refrigeration and air-conditioning are
also selected according to the heat resistance class of the
standard. However, in the case of the organic insulating materials
for the refrigerating and air-conditioning system, the insulating
materials are used in specific environment such as in a refrigerant
atmosphere. Therefore, it is necessary to consider the inhibition
of deformation and alternation due to pressure other than
temperature. Further, the insulating materials are also in contact
with polar compounds such as refrigerants or refrigerating machine
oils. Therefore, a consideration must be also given to solvent
resistance, extraction resistance, stabilities concerning thermal,
chemical and mechanical properties, refrigerant resistance (crazing
(minute pleated crack formed upon immersion in a refrigerant after
applying a stress to the film), blister (bubble in a film caused by
temperature rising of the refrigerant absorbed in the film)), and
the like.
[0052] For this reason, it is necessary to use an insulating
material of a high heat resistance class (class E 120.degree. C. or
more).
[0053] The insulating material most frequently used in a compressor
is PET (polyethylene terephthalate). As the uses thereof, a film
material is used for coil insulation from the iron core of a
distributed winding motor. Fibrous PET is used for the covering
material of the coil binding thread and the lead wire of the
motor.
[0054] As other insulation film than this, mention may be made of
PPS (polyphenylene sulfide), PEN (polyethylene naphthalate), PEEK
(polyether ether ketone), PI (polyimide), PA (polyamide) and the
like.
[0055] Further, for the main insulation covering materials of the
coil, there are used THEIC-modified polyester, polyamide,
polyamideimide, polyesterimide, polyesteramideimide and the like. A
double covered copper wire subjected to double coating of
polyesterimide-amideimide is preferably used.
[0056] It does not matter at all if an extreme-pressure additive,
an oxidation inhibitor, an acid scavenger, a defoamer, a metal
deactivator, and the like are added to the refrigerating machine
oil. Particularly, the polyol ester oil undergoes degradation
caused by hydrolysis in the presence of moisture. Therefore, mixing
of the oxidation inhibitor and the acid scavenger is essential.
[0057] The oxidation inhibitor is preferably DBPC
(2,6-di-t-butyl-p-cresol) of a phenol type.
[0058] As the acid scavengers, there are generally used aliphatic
epoxy type compounds and carbodiimide type compounds as compounds
having epoxy rings. Particularly, the carbodiimide type compounds
are high in reactivity with fatty acids, and trap hydrogen ions
dissociated from fatty acids. Accordingly, the effect of inhibiting
the hydrolysis reaction of the polyol ester oil is very large.
[0059] As the carbodiimide type compound, mention may be made of
bis (2,6-isopropylphenyl) carbodiimide. The amount of the acid
scavenger to be added is preferably set at 0.05 to 1.0 wt % based
on the amount of the refrigerating machine oil.
[0060] Incidentally, an extreme pressure agent may generally be
mixed in the refrigerant for use in a compressor. As the extreme
pressure agents, there are conventionally used tertiary phosphates
such as tricresyl phosphate and triphenyl phosphate.
[0061] In the compressor for refrigeration and air-conditioning of
the present invention it is possible to improve the wear resistance
by using the refrigerants and the refrigerating machine oils. This
eliminates the necessity of using an extreme pressure agent.
Examples 1 to 12
[0062] (Refrigerating Machine Oil Component)
[0063] For the enhancement of efficiency of the compressor for
refrigeration and air-conditioning, the dissolved viscosity of the
refrigerant and the refrigerating machine oil in a mutually
dissolved state (which will be hereinafter simply referred to as
"dissolved viscosity") is the important factor.
[0064] A refrigerant whose lower critical solution temperature at
which liquid-liquid double layer separation starts to occur at low
temperatures is -30.degree. C. or less and a refrigerating machine
oil are combined. In this case, the refrigerant is dissolved in a
large amount in the refrigerating machine oil according to the
compressor operation conditions. Accordingly, the dissolved
viscosity is largely reduced. When the dissolved viscosity in the
compressor is low, not only the compression part sealing property
is reduced, but also the oil film strength at the compressor
sliding part is reduced. Accordingly, wear proceeds, resulting in
degradation of the reliability of the refrigerating and
air-conditioning apparatus. For this reason, the adsorption
property of the refrigerating machine oil component to the sliding
part becomes an important parameter.
[0065] The large part of the sliding part includes an iron-based
material, and on the surface thereof, iron oxide is formed.
[0066] The adsorption capability of the refrigerating machine oil
to an iron-based material in this specification is substantially
considered as the adsorption capability of the refrigerating
machine oil to iron oxide.
[0067] Based on this point of view, in the present example, using a
Fe.sub.3O.sub.4 (triiron tetroxide) powder (specific surface area
1.57 m.sup.2/g) with a mean particle size of 1 .mu.m, the
adsorption capability of the refrigerating machine oil was
evaluated.
[0068] The concentrations of the refrigerating machine oil
component diluted with a solvent before and after adsorption were
quantified by nuclear magnetic resonance spectrometry (NMR). Thus,
the amount of the component adsorbed to the iron oxide powder was
calculated. Hexane was used as the solvent, and adjustment was
performed such that each refrigerating machine oil component was
0.3 mol-ppm. Into a 20-ml screw tube, the iron oxide powder was
collected in an amount of 3 g. Then, a solution of the
refrigerating machine oil components was charged in an amount of 10
g. The solution was dispersed for 30 minutes in an ultrasonic
washer, and was allowed to stand for 48 hours. Then, the
supernatant liquid was subjected to 1H-NMR analysis.
[0069] Herein, mol-ppm is ppm (parts per million) based on moles.
Namely, mol-ppm is ppm calculated with the number of moles of the
solution (mixture of solvent and solute) as the denominator and
with the number of moles of the solute as the numerator.
[0070] The base oil used as the refrigerating machine oil component
is as follows. Herein, the 40.degree. C. kinetic viscosity means
the kinetic viscosity at 40.degree. C.
[0071] (A) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of pentaerythritol type 2-methylhexanoic
acid/2-ethylhexanoic acid): 40.degree. C. kinetic viscosity 31.8
mm.sup.2/s;
[0072] (B) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of neopentyl glycol/pentaerythritol type 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid): 40.degree. C. kinetic viscosity
46.9 mm.sup.2/s;
[0073] (C) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of neopentyl glycol/pentaerythritol type 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid): 40.degree. C. kinetic viscosity
64.8 mm.sup.2/s;
[0074] (D) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of pentaerythritol type 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid); 40.degree. C. kinetic viscosity
91.3 mm.sup.2/s;
[0075] (E) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of dipentaerythritol type 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid): 40.degree. C. kinetic viscosity
190 mm.sup.2/s;
[0076] (F) Hindered type polyol ester oil (POE) (mixed fatty acid
ester oil of dipentaerythritol type 2-ethylhexanoic
acid/3,5,5-trimethylhexanoic acid): 40.degree. C. kinetic viscosity
217 mm.sup.2/s;
[0077] (G) Hindered type polyol ester oil (POE) (dipentaerythritol
type 3,5,5-trimethylhexanoic acid ester oil): 40.degree. C. kinetic
viscosity 417 mm.sup.2/s;
[0078] (H) Polyvinyl ether oil (PVE): 40.degree. C. kinetic
viscosity 50.1 mm.sup.2/s;
[0079] (I) Polyvinyl ether oil (PVE): 40.degree. C. kinetic
viscosity 65 mm.sup.2/s;
[0080] (J) Polyalkylene glycol oil (PAG) (polypropylene glycol
dimethyl ether): 40.degree. C. kinetic viscosity 112
mm.sup.2/s;
[0081] (K) Naphthene type mineral oil: 40.degree. C. kinetic
viscosity 54.1 mm.sup.2/s; and
[0082] (L) Poly-alpha-olefin oil: 40.degree. C. kinetic viscosity
61.8 mm.sup.2/s
[0083] The results of measurement of the adsorption amount of each
compound to the iron oxide powder are shown in Table 1.
TABLE-US-00001 TABLE 1 Refrigerating 40.degree. C. kinetic Iron
oxide Initial Post-adsorption Adsorption machine oil viscosity
amount concentration concentration amount component (mm.sup.2/s)
(g) (mol-ppm) (mol-ppm) (mol/m.sup.2) Example 1 A 31.8 3.0 0.30
0.255 4.85 .times. 10.sup.8 2 B 46.9 3.0 0.30 0.250 5.39 .times.
10.sup.8 3 C 64.8 3.0 0.30 0.260 4.31 .times. 10.sup.8 4 D 91.3 3.0
0.30 0.265 3.77 .times. 10.sup.8 5 E 190 3.0 0.30 0.110 2.05
.times. 10.sup.-7 6 F 217 3.0 0.30 0.110 2.05 .times. 10.sup.-7 7 G
417 3.0 0.30 0.130 1.83 .times. 10.sup.-7 8 H 50.1 3.0 0.30 0.280
2.16 .times. 10.sup.-8 9 I 65 3.0 0.30 0.280 2.16 .times. 10.sup.-8
10 J 112 3.0 0.30 0.280 2.16 .times. 10.sup.-8 11 K 54.1 3.0 0.30
0.290 1.08 .times. 10.sup.-8 12 L 61.8 3.0 0.30 0.290 1.08 .times.
10.sup.-8
[0084] Each compound shows a different adsorption amount to the
iron oxide powder (adsorption capability). It is indicated that the
polar compounds are more likely to be adsorbed to the iron-based
material.
[0085] It is indicated that the compounds (E), (F) and (G) each
including a large amount of ester groups present in the molecular
structure particularly exhibit a large adsorption amount in the
polar compounds. Namely, the compounds (E), (F) and (G) are 2.0 or
more times higher in adsorption capability to an iron-based
material (iron oxide) than other refrigerating machine oil
components (A) to (D) and (H) to (L).
[0086] This indicates that the refrigerating machine oil components
(E), (F) and (G) each tend to form a film at the compressor sliding
part.
[0087] This is considered to be due to the following reason.
[0088] The oxygen of carbonyl (C=0) included in an ester group
tends to be negatively charged. In contrast, the surface of iron
oxide is generally hydrated to be in a structure having a hydroxyl
group. For this reason, the attractive force due to the Coulomb
force is generated between the hydrogen included in the hydroxyl
group in the surface of the iron oxide and the oxygen included in
the ester group, which facilitates adsorption.
[0089] From the results, (E), (F) and (G) were determined to be
used as additive polyol ester oils in the present invention.
Examples 13 to 25
[0090] A refrigerant and a refrigerating machine oil are charged in
the compressor for refrigeration and air-conditioning.
[0091] The compatibility between the refrigerant and the
refrigerating machine oil is one of important characteristics in
terms of ensuring the reliability of the compressor such as oil
return from the refrigeration cycle to the compressor (ensuring the
oil amount inside the compressor) or reduction of the heat exchange
efficiency. However, the dissolved viscosity of the liquid mixture
largely varies according to the amount of the refrigerant dissolved
in the refrigerating machine oil due to the presence of the
refrigerant. A large dissolution amount results in a remarkable
reduction of the viscosity of the oil. Accordingly, a sufficient
oil film strength cannot be obtained at the sliding part. Further,
the function as the sealing material of the compression part is
impaired.
[0092] The compatibility between the refrigerant and the
refrigerating machine oil was evaluated and measured according to
JIS K 2211.
[0093] In a pressure resistant glass container, the refrigerant was
charged at a given oil concentration. Thus, the temperature was
changed to observe the contents. At this step, when the contents
became whitish, the contents were determined as having undergone
two-layer separation. For transparency, the contents were
determined as having undergone dissolution. The oil concentration
dependency of the temperature at which two-layer separation occurs
is generally a curve having a maximum value. This maximum value is
referred to as a lower critical solution temperature. The lower
critical solution temperature is a parameter indicating the degree
of the compatibility between the refrigerant and the refrigerating
machine oil.
[0094] The refrigerating machine oil compatible with each
refrigerant was selected. Thus, the results of measurement of the
lower critical solution temperature are shown in Table 2.
TABLE-US-00002 TABLE 2 40.degree. C. Refrigerating kinetic Lower
critical machine oil viscosity solution Refrigerant component
(mm.sup.2/s) temperature Example 13 HFO1234yf C 64.8 -60.degree. C.
or less 14 HFO1234yf I 65 -60.degree. C. or less 15 Propane C 64.8
-60.degree. C. or less 16 Propane K 54.1 -60.degree. C. or less 17
Propylene C 64.8 -60.degree. C. or less 18 Propylene K 54.1
-60.degree. C. or less 19 HFC161 C 64.8 -60.degree. C. or less 20
HFC161 I 65 -60.degree. C. or less 21 HFC161 K 54.1 -40.degree. C.
22 HFC32 C 64.8 20.degree. C. or more 23 HFC32 I 65 20.degree. C.
or more 24 R410A C 64.8 9.degree. C. 25 R410A I 65 -47.degree.
C.
[0095] The lower critical solution temperature largely varies
according to the degree of compatibility between the refrigerant
and the refrigerating machine oil. Particularly, when HFO1234yf,
propane, propylene or fluoroethane is used as the refrigerant, the
solubility in the refrigerating machine oil is very high, which
causes a large reduction of the viscosity in the operation
conditions of the compressor. Generally, the viscosity grade of the
refrigerating machine oil is increased to take countermeasures
thereagainst. However, the amount of the refrigerant dissolved
increases according to the temperature and pressure in the
operation conditions of the compressor for refrigeration and
air-conditioning. Accordingly, in actuality, the viscosity does not
increase largely.
Examples 26 to 31 and Comparative Examples 1 to 6
[0096] Using a shell type four-ball friction-wear tester, the
lubricity of the refrigerating machine oil was evaluated.
[0097] Using a 1/2-inch SUJ2 steel ball as a specimen, the wear
scar diameter (average of 3 balls) and the coefficient of friction
of each fixed specimen after performing the test under load: 280 N,
temperature: 120.degree. C., rotation speed: 1200 min.sup.-1, and
time: 10 min were measured.
[0098] As the refrigerating machine oil bases, there were used the
polyol ester oils (A) to (D), the polyvinyl ether oil (I), and the
naphthene type mineral oil (K). The mixtures obtained by adding the
additive polyol ester oil (F) in an amount of 5.0 wt % thereto were
evaluated.
[0099] As Comparative Examples, evaluation was made on the cases of
the polyol ester oils (A) to (D) used alone, the case of the
polyvinyl ether oil (I) used alone, and the case of the naphthene
type mineral oil (K) used alone.
[0100] The results of evaluation of the lubricity of each
refrigerating machine oil are shown in Table 3.
TABLE-US-00003 TABLE 3 Refrigerating 40.degree. C. machine oil
kinetic Wear scar component viscosity diameter Coefficient Basis
Additive (mm.sup.2/s) (mm) of friction Example 26 A F (5 wt %) 34.7
0.57 0.23 27 B F (5 wt %) 50.4 0.51 0.22 28 C F (5 wt %) 68.6 0.49
0.23 29 D F (5 wt %) 95.2 0.48 0.21 30 I F (5 wt %) 68.9 0.46 0.18
31 K F (5 wt %) 57.5 0.45 0.18 Compar- 1 A None 31.8 0.62 0.36
ative 2 B None 46.9 0.57 0.35 Example 3 C None 64.8 0.58 0.35 4 D
None 91.3 0.55 0.33 5 I None 65 Seizure Seizure occurred occurred 6
K None 54.1 Seizure Seizure occurred occurred
[0101] The results indicate the following: for the refrigerating
machine oils not including the additive polyol ester oil (F) mixed
therein of Comparative Examples 1 to 4, each wear scar diameter is
large, and each coefficient of friction is high; for Comparative
Examples 5 and 6, the test was stopped because of the occurrence of
seizure immediately after the start of the test.
[0102] In contrast, for the refrigerating machine oils each
including the additive polyol ester oil (F) mixed therein shown in
Examples 26 to 31, each wear scar diameter and each coefficient of
friction were suppressed regardless of the oil species of the
refrigerating machine oil basis. Thus, the lubricity improving
effect was produced. This is due to the following fact. The
adsorption capability of the additive polyol ester oil (F) to the
iron-based material is larger than that of the refrigerating
machine oil basis. Accordingly, the friction surface was rendered
in a low surface energy state. This produced the wear resistance
and an effect of reducing the coefficient of friction. Also when
the refrigerating machine oil bases were the polyvinyl ether oil
(I) and the naphthene type mineral oil (K), seizure did not occur.
Particularly, when the refrigerating machine oil basis is the
polyvinyl ether oil (I) or the naphthene type mineral oil (K)
exhibiting a smaller adsorption amount than that of the additive
polyol ester oil (F) as shown in Table 1, the additive polyol ester
oil (F) becomes more likely to be adsorbed on the friction surface.
For this reason, the lubricity improving effect tends to be
produced.
Examples 32 to 37 and Comparative Examples 7 to 8
[0103] In order to observe the effects of the additive polyol ester
oils (E) and (G), the same test as in Example 26 was performed
using the shell type four-ball friction-wear tester, except for
changing the type and the addition amount of the additive polyol
ester oil.
[0104] The results of evaluation of the lubricity of each
refrigerating machine oil are shown in Table 4.
TABLE-US-00004 TABLE 4 Refrigerating 40.degree. C. machine oil
kinetic Wear scar Co- component viscosity diameter efficient Basis
Additive (mm.sup.2/s) (mm) of friction Example 32 C F (1 wt %) 65.5
0.52 0.23 33 C F (10 wt %) 72.7 0.48 0.22 34 C F (20 wt %) 81.7
0.49 0.23 35 C F (30 wt %) 91.9 0.48 0.21 36 C E (5 wt %) 68.2 0.51
0.25 37 C G (5 wt %) 70.6 0.52 0.25 Compar- 7 C F (0.1 wt %) 64.9
0.58 0.35 ative 8 C F (0.5 wt %) 65.2 0.57 0.33 Example
[0105] For the refrigerating machine oils of Examples 32 to 37
shown in this table, as compared with the refrigerating machine oil
using (C) as the refrigerating machine oil basis, and not including
an additive added thereto of Comparative Example 3 (shown in Table
3), the wear scar diameter and the coefficient of friction were
suppressed. Thus, it was possible to observe the lubricity
improving effect.
[0106] Whereas, in the cases of Comparative Examples 7 and 8 each
having a small amount of the additive polyol ester oil (F) added
therein, each wear scar diameter is large, and each coefficient of
friction is high. Accordingly, the lubricity improving effect is
less likely to be exerted. In contrast, for the refrigerating
machine oils in each of which the additive polyol ester oil (F) is
added in an amount of 1.0 wt % or more based on the amount of the
refrigerating machine oil basis shown in Examples 32 to 35, each
wear scar diameter and each coefficient of friction are suppressed.
This produced the lubricity improving effect.
Examples 38 and 39, Comparative Examples 9 and 10
[0107] FIG. 1 shows the outline of a dual-purpose cooling/heating
room air conditioner used in the present Examples.
[0108] When an inside of a room is cooled, a high-temperature
high-pressure refrigerant gas (charged refrigerant) adiabatically
compressed through a discharge pipe of a compressor 1 passes
through a four-way valve 2 to be cooled in an outdoor heat
exchanger 3 (used as a condensing means), resulting in a
high-pressure liquid refrigerant. The refrigerant is expanded in an
expansion means 4 (such as a capillary tube or a temperature type
expansion valve, which is also referred to as a pressure reducing
unit), resulting in a low-temperature low-pressure solution
slightly containing a gas. The solution reaches the indoor heat
exchanger 5 (used as an evaporation means), and gets heat from the
air inside the room, resulting in a low-temperature gas form. The
resulting gas passes through the four-way valve 2 again, and
reaches the compressor 1. When the inside of the room is heated,
the flow of the refrigerant is changed to the opposite direction by
the four-way valve 2, resulting in the adverse effect. In the
present example, a scroll compressor was used as the
compressor.
[0109] FIG. 2 shows the schematic structure thereof.
[0110] In the compressor, a spiral wrap 8 standing upright on an
end plate 7 of a fixed scroll member 6, and a rotary scroll member
9 having a wrap 10 in substantially the same shape as that of the
fixed scroll member 6 are engaged with the wrap 8 and the wrap 10
facing each other. As a result, a compression mechanism part is
formed. And the rotary scroll member 9 is caused to undergo rotary
movement by a crank shaft 11. A compression chamber situated on the
outermost side of compression chambers 12a and 12b formed by the
fixed scroll member 6 and the rotary scroll member 9 moves toward
the central part formed of the fixed scroll member 6 and the rotary
scroll member 9 while gradually shrinking in volume with the rotary
movement. When the compression chambers 12a and 12b reach the
vicinity of the central part including the fixed scroll member 6
and the rotary scroll member 9, the compression chambers 12a and
12b communicate with the discharge port 13. Accordingly, the
compressed gas in the compression chambers 12a and 12b is
discharged through the discharge pipe 16 to the outside of the
compressor.
[0111] In the compressor of the present example, an electric motor
17 is included in a pressure vessel 15. Thus, the compressor
performs a compression operation by rotation of the crank shaft 11
at a given constant speed or at a rotation speed according to the
voltage controlled by an inverter not shown. Further, an oil
reservoir part 20 is provided below the motor 17. The oil in the
oil reservoir part 20 passes through an oil path 19 provided in the
crank shaft 11 due to the difference in pressure, and is subjected
to lubrication of the sliding part between the rotary scroll member
9 and the crank shaft 11, a sliding bearing 18 and the like.
[0112] In Examples 38 and 39 and Comparative Examples 9 and 10, the
indoor unit was set in a thermostatic chamber (35.degree. C.,
humidity 75%) to perform an actual equipment test of 2160-hour
operation using the room air conditioner shown in FIG. 1.
[0113] A heat-resistant PET film (type B 130.degree. C.) was used
for coil insulation from the iron core of the motor 17. There was
used a double covered copper wire subjected to double coating of
polyesterimide-amideimide for coil main insulation.
[0114] For evaluation of the room air conditioner, attention was
given to the wear state of the scroll compressor. Thus, there was
measured the clearance increment due to wear from the frame 14 to
the crank shaft 11 (between the frame 14 and the crank shaft 11)
before and after the test. A larger clearance increment from the
frame 14 to the crank shaft 11 (which will be hereinafter also
referred to as between the frame and the shaft) indicates a larger
wear amount. Generally, as the clearance increment increases,
vibration and noise increase.
[0115] HFO1234yf (2,3,3,3-tetrafluoropropene) was used alone as the
refrigerant. The HFO1234yf is a low-pressure refrigerant. The
amount of circulating refrigerant is small, resulting in an
increase in pressure loss in piping. For this reason, evaluation
was conducted in the following manner: the displacement amount of
the compressor was set at two times higher than usual, and the
diameter of the connection piping was increased, and the number of
paths of the heat exchanger was increased; thus, the distribution
balance was adjusted.
[0116] In a refrigerating and air-conditioning cycle using
HFO1234yf and HFO1234ze, and a mixed refrigerant including these,
the compatibility between the refrigerant and the refrigerating
machine oil becomes an important characteristic for ensuring the
amount of oil to be returned to the compressor. In the
refrigerating and air-conditioning cycle, it is necessary that the
refrigerating machine oil also circulates as with the refrigerant.
When the compatibility is inferior, the refrigerating machine oil
discharged by a mechanical element from the compressor does not
circulate. Accordingly, the oil separated particularly at the
low-temperature part is retained, resulting in a smaller oil amount
of the compressor. This hinders the lubricating oil of the sliding
part. For this reason, it is preferable that the refrigerant and
the refrigerating machine oil are dissolved within the operating
condition temperature range in the cycle.
[0117] With respect to HFO1234yf, hydrocarbon oils such as
naphthene type mineral oils, paraffin type mineral oils,
alkylbenzene oils and poly-alpha-olefin oils are less likely to be
miscible. Therefore, a polyol ester oil or a polyvinyl ether oil is
preferable.
[0118] In Example 38, evaluation was performed using the
refrigerating machine oil ((C)+(F)) adopted in Example 28 having
compatibility with HFO1234yf. Whereas, in Example 39, evaluation
was performed using the refrigerating machine oil ((I)+(F)) adopted
in Example 30.
[0119] As the refrigerating machine oil basis, the oil (C) or (I)
was used. The oil (F) having a high adsorption capability thereto
is mixed in an amount of 5 wt % therein. Thus, there was carried
out a test with a refrigerating machine oil having a kinetic
viscosity at 40.degree. C. set at 68.6 mm.sup.2/s or 68.9
mm.sup.2.
[0120] In Comparative Examples 9 and 10, the test was carried out
with only the refrigerating machine oil bases in each of which the
additive polyol ester oil in Examples 38 and 39 was not added.
[0121] As the target value of this test, the clearance increment
due to wear between the frame and the shaft after the test is 10
.mu.m or less.
[0122] The results of Examples 38 and 39 and Comparative Examples 9
and 10 are shown in Table 5.
TABLE-US-00005 TABLE 5 Refrigerating machine oil 40.degree. C.
kinetic Sliding bearing component viscosity Clearance Cooling
intermediate conditions Refrigerant Basis Additive (mm.sup.2/s)
increment (.mu.m) Viscosity (mPa s) COP(%) Example 38 HFO1234yf C F
(5 wt %) 68.6 3 1.8 101 (Ratio based on reference 1) 39 HFO1234yf I
F (5 wt %) 68.9 4 2.2 101.5 (Ratio based on reference 1) 40 R290 C
F (5 wt %) 68.6 5 2.0 102 (Ratio based on reference 2) 41 R290 K F
(5 wt %) 57.5 6 1.5 101 (Ratio based on reference 2) 42 R410A C F
(5 wt %) 68.6 2 3.8 101 (Ratio based on reference 3) Comparative 9
HFO1234yf C None 64.8 12 1.2 100 (Reference 1) Example 10 HFO1234yf
I None 65 18 1.3 100 (Ratio based on reference 1) 11 R290 C None
68.6 15 1.1 100 (Reference 2) 12 R290 K None 57.5 24 0.9 98 (Ratio
based on reference 2) 13 R410A C None 68.6 8 3.7 100 (Reference
3)
[0123] As apparent from Table 5, for the room air conditioners of
Examples 38 and 39, as compared with Comparative Examples 9 and 10,
the frame-shaft clearance increment can be largely reduced.
Accordingly, wear is inhibited. As a result, high reliability can
be obtained in the room air conditioner.
[0124] Further, in Table 5, regarding each combination of the
refrigerants and the refrigerating machine oils, the measurement
results of the viscosity and an efficiency in a cooling
intermediate conditions are also shown.
[0125] For the measurement of the viscosity, a piston type
viscometer from Japan Controls Co., Ltd. was used.
[0126] Further, the efficiency is expressed as the ratio using
Coefficient of Performance (COP) with Comparative Example 9 as the
reference (100).
[0127] The results indicate as follows. In Comparative Examples 9
and 10, reduction of the viscosity occurred, so that a sufficient
sealing property could not be obtained at the compression part. In
contrast, the viscosity increased in Examples 38 and 39.
[0128] Further, as shown in Examples 28 and 30 of Table 3, the
friction inhibiting effect due to the additive polyol ester oil was
exhibited. Accordingly, the coefficient of performance was improved
as compared with Comparative Example 9 (reference From the results
of Examples up to this point, it has been indicated that there can
be obtained a refrigerating and air-conditioning apparatus capable
of inhibiting wear of the compressor, and sufficiently ensuring the
long-term insulation reliability.
[0129] Further, although not shown, evaluation was performed by the
same actual equipment test with a combination of a mixed
refrigerant of HFO1234yf and HFC32 (20 wt % and 40 wt %) for the
refrigerant and the refrigerating machine oil ((C)+(F)) adopted in
Example 28. As a result, roughly the same results as those of
Examples 38 and 39 were obtained. This has indicated that even use
of a mixed refrigerant can produce effects, and produces no
problem.
Examples 40 to 42 and Comparative Examples 11 to 13
[0130] In Examples 40 to 42, propane and R410A were used for the
refrigerant. Thus, refrigeration cycles in accordance with
respective refrigerants were prepared to perform the same actual
equipment test as that of Example 38.
[0131] In Example 40, there were used propane as the refrigerant,
and a refrigerating machine oil including the oil (C) as the
refrigerating machine oil basis, and the oil (F) as an additive
polyol ester oil mixed in an amount of 5.0 wt % therein.
[0132] In Example 41, there were used propane as the refrigerant,
and a refrigerating machine oil including the oil (K) as the
refrigerating machine oil basis, and the oil (F) as an additive
polyol ester oil mixed in an amount of 5.0 wt % therein.
[0133] In Example 42, there were used R410A as the refrigerant, and
a refrigerating machine oil including the oil (C) as the
refrigerating machine oil basis, and the oil (F) as an additive
polyol ester oil mixed in an amount of 5.0 wt % therein. In
Comparative Examples 40 to 42, evaluations were respectively made
on the refrigerating machine oils each not including the additive
polyol ester oil added therein.
[0134] The evaluation results are shown in Table 5.
[0135] Propane has a high solubility in polyol ester oil, mineral
oil or the like as shown in the evaluation results of the
compatibility of Table 2. This causes a large reduction of
viscosity in the compressor. Further, propane does not contain a
halogen atom in the molecular structure, and hence does not form
iron halide contributing to the lubricity at a friction-generating
site. This results in a large increase in clearance increment due
to friction between the frame and the shaft as shown in Comparative
Examples 11 and 12.
[0136] In contrast, as shown in Examples 40 and 41, for the
combination including the additive polyol ester oil (F) mixed to
the refrigerating machine oil basis, the clearance increment due to
the wear between the frame and the shaft was largely reduced,
resulting in ease of friction. As a result, the Coefficient of
Performance (COP) improved as compared with Comparative Example 11
(reference 2).
[0137] Further, in Example 42 using R410A as the refrigerant, as
compared with Comparative Example 13 (reference 3), the clearance
increment due to the wear between the frame and the shaft was
suppressed, and the Coefficient of Performance (COP) also
improved.
[0138] This indicates that even refrigerants such as
difluoromethane, fluoroethane and propylene can provide the same
effects regardless of the type of the refrigerant.
[0139] Other than these, the same effects can also be produced by a
rotary compressor, a twin rotary compressor, a two-stage
compression rotary compressor, and a swing compressor including a
roller and a vane integrated with each other.
[0140] The present invention is applicable to a refrigerant
compressor for a refrigerating and air-conditioning apparatus, and
a refrigerating and air-conditioning apparatus.
* * * * *