U.S. patent application number 12/997178 was filed with the patent office on 2011-08-04 for lubricants for air conditioning systems.
This patent application is currently assigned to Bright Solutions International LLC. Invention is credited to Terrence D. Kalley.
Application Number | 20110190184 12/997178 |
Document ID | / |
Family ID | 41417086 |
Filed Date | 2011-08-04 |
United States Patent
Application |
20110190184 |
Kind Code |
A1 |
Kalley; Terrence D. |
August 4, 2011 |
Lubricants for air conditioning systems
Abstract
Lubricants for air conditioning systems in hybrid vehicles can
be high dielectric lubricants.
Inventors: |
Kalley; Terrence D.; (Troy,,
MI) |
Assignee: |
Bright Solutions International
LLC
Troy
MI
|
Family ID: |
41417086 |
Appl. No.: |
12/997178 |
Filed: |
June 9, 2009 |
PCT Filed: |
June 9, 2009 |
PCT NO: |
PCT/US09/46674 |
371 Date: |
March 9, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61059892 |
Jun 9, 2008 |
|
|
|
Current U.S.
Class: |
508/519 ;
180/65.21; 508/110; 508/579 |
Current CPC
Class: |
C10M 171/008 20130101;
C10N 2030/20 20130101; C10N 2040/16 20130101; C10M 2209/108
20130101; C10M 2207/283 20130101; C10N 2040/30 20130101; C09K 5/041
20130101; C10M 2227/04 20130101; C10M 2209/103 20130101; C10M
171/007 20130101 |
Class at
Publication: |
508/519 ;
508/110; 508/579; 180/65.21 |
International
Class: |
C10M 105/38 20060101
C10M105/38; C10M 169/04 20060101 C10M169/04; C10M 105/18 20060101
C10M105/18 |
Claims
1. A method of dehydrating a lubricant in an air conditioning
system of an electric compressor comprising introducing a water
scavenger into the system of the electric compressor.
2. The method of claim 1, wherein the electric compressor is in a
hybrid vehicle.
3. The method of claim 1, wherein the lubricant is polyalkylene
glycol or polyolester.
4. (canceled)
5. The method of claim 1, further comprising introducing an
additive into the system.
6. (canceled)
7. The method of claim 5, wherein the additive is a leak detection
dye and the lubricant is polyalkylene glycol.
8. The method of claim 5, wherein the additive has high dielectric
strength.
9. The method of claim 1, wherein the water scavenger is added to
the lubricant prior to introduction of the compressor lubricant to
the system of the hybrid vehicle.
10. The method of claim 1, wherein the water scavenger is an
organometallic compound or an organometalloid compound.
11. (canceled)
12. The method of claim 1, further comprising introducing an
indicator compound that indicates the presence of water in the
system.
13. The method of claim 12, wherein the indicator compound is a
compound that fluoresces in the presence of water.
14. A method of minimizing or eliminating the risk of an electrical
shock to a subject in contact with a system in a hybrid vehicle
comprising introducing a high dielectric lubricant into the
air-conditioning system of the hybrid vehicle wherein the lubricant
is a polyalkylene glycol and has a water content of below 500 ppm,
the lubricant has a volume resistivity between 6.times.10.sup.11 to
12.times.10.sup.11 ohm cm, the lubricant has a dielectric strength
between 35-40 kV, the lubricant has a dielectric strength between
35-40 kV and a volume resistivity of at least 1.times.10.sup.12 ohm
cm, the lubricant has a dielectric strength between 35-40 kV and
block weight loss of more than 30 mg in a modified Falex test in
R-134a atmosphere using aluminum pins and blocks per ASTM D3233 at
200 lb for 60 second.
15. The method of claim 14, wherein the polyalkylene glycol has a
water content of below 300 ppm.
16. The method of claim 14, wherein the polyalkylene glycol has a
water content of below 50 ppm.
17. The method of claim 14, wherein the polyalkylene glycol has a
total acid number of <0.1 mgKOH/g.
18. (canceled)
19. The method of claim 14, wherein introducing the high dielectric
lubricant into the air-conditioning system of the hybrid vehicle
includes using an injection device.
20. The method of claim 19, wherein the high dielectric lubricant
includes a leak detection dye.
21. (canceled)
22. The method of claim 14, wherein the lubricant has a volume
resistivity between 10.times.10.sup.11 to 12.times.10.sup.11 ohm
cm.
23-30. (canceled)
31. The method of claim 30, wherein the lubricant is polyalkylene
glycol.
32. The method of claim 30, wherein the lubricant is
polyolester.
33. (canceled)
34. The method of claim 14, wherein the additive includes a water
scavenger, a leak detection dye, a leak stop additive, or a
performance-enhancing product.
35-36. (canceled)
37. The method of claim 14, wherein the water scavenger is an
organometallic compound or an organometalloid compound.
38. (canceled)
39. The method of claim 14, further comprising introducing an
indicator compound that indicates the presence of water in the
system.
40. The method of claim 14, wherein the indicator compound is a
compound that fluoresces in the presence of water.
41. The method of claim 14, further comprising introducing an
indicator compound that indicates that the lubricant is a high
dielectric lubricant.
42. The method of claim 41, wherein the indicator compound is a
compound that can be differentiated visually.
43. The method of claim 41, wherein the indicator compound is a
compound that can be differentiated though an odor.
44-48. (canceled)
Description
CLAIM FOR PRIORITY
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/059,892, filed on Jun. 9, 2008, which is hereby
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] This invention relates to lubricants for air conditioning
systems in hybrid vehicles.
BACKGROUND
[0003] Regular vehicle manufacturers have used polyalkylene glycols
(PAGs) as a compressor lubricant with refrigerant for many years.
PAGs are chosen over polyolesters (POEs) due to superior
performance characteristics such as protection against wear and
greater thermal and chemical stability. Further, PAGs have superior
hydrodynamic lubricity, better low temperature properties, superior
chemical stability, superior hydrolytic stability and better
elastomers and plastic compatibilities. In addition, the viscosity
of a PAG is retained over broader temperature ranges as measured
via a viscosity index. However, the hybrid car industry perceives
PAGs as having a distinct technical disadvantage compared to POE as
PAGs have high water absorption and poor electrical resistivity
properties.
[0004] The use of PAGs is especially disadvantageous when used as a
lubricant in air conditioning systems powered by high voltage
electrical systems (typically battery voltages between 144-330
volts) in hybrid vehicles, more specifically when used in
electrically driven compressors. In circuits with a boost
converter, the battery pack voltages can double. There are also
so-called "mild hybrids" using 42 volt systems such as the 2008
Saturn Vue and Aura and the 2008 Chevrolet Malibu. Such high
voltage in these electrical systems results in risks to technicians
in certain situations including when servicing these hybrid
vehicles and to other persons such as emergency responders in
accident situations. There is also risk of damage to the A/C system
and its components such as a compressor and possibly with the
recovery and recycling equipment used to service A/C systems.
SUMMARY
[0005] Advantageously, high dielectric lubricants with low or no
water content and low conductivity can be used in air-conditioning
systems in hybrid vehicles to reduce or eliminate risks to subjects
in contact with such vehicles.
[0006] In one aspect, a method of dehydrating a lubricant in an air
conditioning system of an electric compressor can include
introducing a water scavenger into the system of the electric
compressor. The electric compressor can be in a hybrid vehicle. The
lubricant can be polyalkylene glycol or polyolester. The method can
further include introducing an additive into the system. The
additive can include a leak detection dye, a leak stop additive, or
a performance-enhancing product. The additive can be a leak
detection dye and the lubricant can be polyalkylene glycol. The
additive can have high dielectric strength. The water scavenger can
be added to the lubricant prior to introduction of the compressor
lubricant to the system of the hybrid vehicle. The water scavenger
can be an organometallic compound or an organometalloid compound.
The method can further include introducing an indicator compound
that indicates the presence of water in the system. The indicator
compound can be a compound that fluoresces in the presence of water
or shows a change in color or odor in the presence of water.
[0007] In another aspect, a method of minimizing or eliminating the
risk of an electrical shock to a subject in contact with systems in
a hybrid vehicle can include introducing a high dielectric
lubricant into the air-conditioning system of the hybrid vehicle
wherein the lubricant is a polyalkylene glycol and has a water
content of below 500 ppm. The polyalkylene glycol can have a water
content of below 300 ppm. The polyalkylene glycol can have a water
content of below 50 ppm. The polyalkylene glycol can have a total
acid number of <0.1 mgKOH/g. The polyalkylene glycol can have a
total acid number of <0.1 mgKOH/g.
[0008] In a further aspect, a method of minimizing or eliminating
the risk of an electrical shock to a subject in contact with
systems in hybrid vehicle can include introducing a high dielectric
lubricant into the air-conditioning system of the hybrid vehicle
wherein the lubricant has a volume resistivity between
6.times.10.sup.11 to 12.times.10.sup.11 ohm cm. The lubricant can
have a volume resistivity between 10.times.10.sup.11 to
12.times.10.sup.11 ohm cm. The lubricant can have a water content
of below 50 ppm. The method can include introducing the high
dielectric lubricant into the air-conditioning system of the hybrid
vehicle includes using an injection device. The high dielectric
lubricant can include a leak detection dye.
[0009] In one aspect, a method of minimizing or eliminating the
risk of an electrical shock to a subject in contact with systems in
hybrid vehicle can include introducing a high dielectric lubricant
into the air-conditioning system of the hybrid vehicle wherein the
lubricant has a dielectric strength between 35-40 kV. The lubricant
can have a water content of below 50 ppm. The method can include
introducing the high dielectric lubricant into the air-conditioning
system of the hybrid vehicle includes using an injection device.
The high dielectric lubricant can include a leak detection dye.
[0010] In one aspect, a method of minimizing or eliminating the
risk of an electrical shock to a subject in contact with systems in
a hybrid vehicle can include introducing a high dielectric
lubricant into the air-conditioning system of the hybrid vehicle
wherein the lubricant has a dielectric strength between 35-40 kV
and a volume resistivity of at least 1.times.10.sup.12 ohm cm. The
lubricant can be polyalkylene glycol. The lubricant can be
polyolester. The method can further include g introducing an
additive into the system. The additive can include a water
scavenger, a leak detection dye, a leak stop additive, or a
performance-enhancing product. The additive can have high
dielectric strength.
[0011] The water scavenger can be added to the lubricant prior to
introduction of the compressor lubricant to the system of the
hybrid vehicle. The water scavenger can be an organometallic
compound or an organometalloid compound. The method can further
include introducing an indicator compound that indicates the
presence of water in the system. The indicator compound can be a
compound that fluoresces in the presence of water. The method can
further include introducing an indicator compound that indicates
that the lubricant is a high dielectric lubricant. The indicator
compound can be a compound that can be differentiated visually. The
indicator compound can be a compound that can be differentiated
though an odor. The method can include introducing the high
dielectric lubricant into the air-conditioning system of the hybrid
vehicle includes using an injection device. The high dielectric
lubricant can include a leak detection dye.
[0012] In another aspect, a method of minimizing or eliminating the
risk of an electrical shock to a subject in contact with systems in
hybrid vehicle can include introducing a high dielectric lubricant
into an air-conditioning system of the hybrid vehicle wherein the
lubricant has a dielectric strength between 35-40 kV and block
weight loss of more than 30 mg in a modified Falex test in R-134a
atmosphere using aluminum pins and blocks per ASTM D3233 at 200 lb
for 60 seconds. The method can include introducing the high
dielectric lubricant into the air-conditioning system of the hybrid
vehicle includes using an injection device. The high dielectric
lubricant can include a leak detection dye.
[0013] The details of one or more embodiments are set forth in the
accompanying drawings and the description below. Other features,
objects, and advantages of the invention will be apparent from the
description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a graph depicting the results of a basic
hygroscopicity test demonstrating the water content of Zerol RFL
and Idemitsu dicapped PAG at different time points.
[0015] FIG. 2A is a graph depicting the volume resistivity of Zerol
RFL and Idemitsu dicapped PAG when the total acid number (TAN)
constant for all samples is at 0.03 mgKOH/g.
[0016] FIG. 2B is a graph depicting the volume resistivity of Zerol
RFL and Idemitsu dicapped PAG when the water content constant for
all samples is at 50 ppm.
[0017] FIG. 3 is a graph depicting the results of a modified Falex
Test in R-134a atmosphere.
DETAILED DESCRIPTION
[0018] To minimize or eliminate the risk of an electrical shock to
subjects in contact with systems in hybrid or electric cars and/or
to limit damage to such systems and/or their components, lubricants
with low conductivity or high resistivity can be introduced into
the air conditioning systems of hybrid or electric vehicles.
Systems in hybrid cars can include air-conditioning (A/C) systems
or climate control systems. Subjects who are in contact with such
systems can include technicians who are servicing such vehicles or
emergency responders who are responding to an emergency situation
involving such vehicles or vehicle operators involved in such
emergency situations or workers involved with the assembly of A/C
systems or the assembly of hybrid or electric vehicles.
[0019] In addition to the fear of electrical shock, there is also
the fear of cross contamination of A/C system caused by using a
lubricant not intended for use in a particular system. Since about
1993 almost all vehicle worldwide have used PAGs as their
compressor lubricants. These compressors will perform less than
optimally and may experience a reduced life with another lubricant
such as a POE and may actually experience failure with the wrong
lubricant. With the current use of POEs in electrical and/or hybrid
vehicles, there is a fear that these POEs might inadvertently find
there way into vehicles for which PAGs are the original equipment
manufacturer (OEM) specified lubricant. This may occur in a
production/assembly environment or during service. This may be the
result of selecting the incorrect lubricant container or of using a
dispensing device such as a hand-held injector or an injection
device which is part of a recovery and recycling machine or an
injection device which is part of the lubricant insertion process
during manufacturing or assembly which has some or all of its
contents of the incorrect lubricant type.
[0020] Similarly, the use of a PAG with high moisture content in a
hybrid or electrical system where a lower moisture POE is specified
for usage, may result in cross contamination with severe
consequences for individuals and systems as previously outlined. As
a consequence, the SAE specification for contamination, currently
at 1%, is being revised down to 0.1%. Denso has shown that 1% of
PAG oil (such as its ND8) in an electric motor-drive compressor
system lowers resistance to about 1 megaohm, well below the over-10
megaohm provided by the usage of 100% of its ND11 oil, a POE. See
FIG. 2 of Weissler, Peter, "Hybrid oils, trace dyes and the
cross-contamination issue-Special recovery/recycle/recharge
techniques required when servicing hybrids with electric-drive
compressors." MACS Service Reports, p. 1-8. March 2008 issue, which
is incorporated by reference in its entirety.
[0021] The ideal scenario for the A/C industry is to have one
compressor lubricant that can service the needs of existing R-134a
systems designed for using PAGs as well as future systems for
electrical or hybrid vehicles with their needs for high dielectric
strength lubricants. A high resistivity PAG would be able to meet
the needs of both market segments. This high resistivity PAG would
have the added benefits versus POEs of superior performance
characteristics such as protection against wear and greater thermal
and chemical stability, superior hydrodynamic lubricity, better low
temperature properties, superior chemical stability, superior
hydrolytic stability and better elastomers and plastic
compatibilities.
[0022] In one embodiment, high dielectric lubricants with low water
content, low conductivity or high resistivity can be used. For
example, the high dielectric lubricant can have a low water content
of less than 2000 ppm, less than 1500 ppm, less than 1000 ppm, less
than 500 ppm, less than 300 ppm, less than 250 ppm, less than 100
ppm or less than 50 ppm. The high dielectric lubricant can have a
volume resistivity of between 10.times.10.sup.11 to
12.times.10.sup.11 ohm cm, 8.times.10.sup.11 ohm cm to
10.times.10.sup.11 ohm cm, between 6.times.10.sup.11 ohm cm to
8.times.10.sup.11 ohm cm or between 6.times.10.sup.11 ohm cm to
12.times.10.sup.11 ohm cm. The high dielectric lubricant can have a
dielectric strength of between 30-35 kV, between 35-40 kV or
between 40-45 kV. Examples of such lubricants can include double
end-capped PAGs. Such PAGs can be asymmetrically capped PAGs and
can be further additised. The PAGs can have a total acid number
(TAN) of below 0.5 mgKOH/g or below 0.1 mgKOH/g. The PAGs can have
a total acid number of 0.03 mgKOH/g. Alternatively, a suitable PAG
can be chosen based on a combination of TAN/water content
specification. Examples of capped PAGs are described in U.S. Pat.
No. 6,374,629, which is incorporated by reference in its entirety.
Examples of such PAGs include Zerol RFL-X or Zerol HYPAG 46
distributed by Shrieve Chemical Company, Houston, Tex. and
manufactured by Cognis U.K. Ltd.)
[0023] In a further embodiment, risks to a subject in contact with
high voltage systems in a hybrid or electric vehicle can be reduced
by introducing a water scavenger into the system or the lubricant
that can bind or otherwise react with water before or after the
lubricant is introduced into the system. This can have the effect
of dehydrating the system or the oil. In one embodiment, the
lubricant can be packaged for injection during servicing into
containers which are sealed or devoid of air, or into containers
which contain an inert dry gas, such as nitrogen, or a water
scavenger or a combination of inert dry gas and a water scavenger.
Examples of lubricants can include but are not limited to, a
hydrocarbon such as natural or refined mineral oil, a synthetic
hydrocarbon (SHC), an alkylbenzene (AB), a polyalphaolefin (PAO), a
synthetic polyalkylene glycol, for example, that can be terminated
as mono- or diethers or as esters, and a general class of
polyolester lubricant, for example, that can be either di-, tri-,
tetra- or polyfunctional pentaerythritol esters. Containers can
include metal containers including those made largely of tin and
plastic containers either rigid in construction or more formless,
such as a bag. Plastic containers may be constructed of high
density polyethylene, may include a barrier seal, and may include
nylon or any other suitable material to protect the contents from
moisture. The containers may be attachable to injection devices,
which may be constructed in such a way as to minimize moisture
invasion. Such injection devices my be attachable to the port of an
A/C or refrigeration system or to a recovery and recycling machine
or to a manifold gauge set or to a hose or other fluid conduit
connected to any of the aforementioned systems, machines or
devices.
[0024] Examples of water scavengers can include organometalloid
and/or organometallic compounds as described in U.S. Pat. No.
5,882,543, which is incorporated by reference in its entirety.
Other methods of removing water are described in U.S. Pat. Nos.
4,304,805, 4,331,722, 4,379,067, 4,442,015 and 4,508,631 of Packo
et al. which teaches the use of silicon-containing compounds
including certain mercaptosilanes, acyloxysilanes, aminosilanes,
and alkoxysilanes in conjunction with acetic anhydride or
aminosilanes. In one embodiment, the water scavengers can be used
to dehydrate a lubricant before or while adding a leak stop
additive which can prevent the water scavenger from being activated
prematurely by the moisture present in the air-conditioning system.
Examples of leak stop additives are described in U.S. Pat. No.
5,882,543 entitled "Compositions and methods for dehydrating,
passivating and sealing systems," which is incorporated by
reference in its entirety. An example of a water scavenger used
includes dimethyldimethoxysilane in BSL471 from Bright
Solutions.
[0025] It may be useful to use water scavengers with high flash
points of between 150 to 300 degrees Fahrenheit, which can be
beneficial for safety purposes in an operating environment and to
meet less stringent and less costly shipping regulations. An
example of a high-flash point water scavenger includes
octylmethyldiethoxysilane, which has a flash point in excess of 200
degrees Fahrenheit. Other examples include
phenylmethydimethoxysilane with a flash point of approximately 168
degrees Fahrenheit and diphenyldimethoxysilane with a flash point
of approximately 250 degrees Fahrenheit.
[0026] The water scavenger can have the ability to react with water
and thereby sequester it from the A/C system. The by-product of
this reaction can preferably have good lubricating properties. More
preferably, the by-product can be some form of silicon lubricant.
The by-product can be of high resistivity.
[0027] The presence of water or moisture in an air conditioning
system can be determined by an indicator compound that provides
colored visual indication such as fluorescence. Examples of such
indicator compounds can include DF5301 Yellow Industrial Water Dye
manufactured and sold by Corrosion Consultants Inc. in Bloomington,
Minn. Other suitable indicator compounds that fluoresce in the
presence of moisture or water may be used. Examples of indicator
compounds can include providing an odorant in a water soluble
matrix or barrier such that the presence of water or moisture
causes the water soluble matrix or barrier to dissolve releasing
the odorant as described in U.S. Pat. No. 6,063,632, which is
incorporated by reference in its entirety. Other suitable indicator
compounds that release an odor in the presence of moisture or water
may be used.
[0028] In another embodiment, an additive can be added together
with the lubricant and the water scavenger into the air
conditioning system of a hybrid vehicle or the water scavenger may
be absent. The additive can be oil, leak detection dye, or a
performance-enhancing product, for example, a substance that
prolongs the life of the system, a system component, or an assembly
of system components. The additive can further include leak stop
agents, air-conditioning temperature lowering additives,
refrigerant, a leak stop additive for metal leaks, a leak stop
additive for elastomeric leaks and an additive for conditioning
o-rings. One or more of the additives can be introduced together
with the lubricant and the water scavenger. All additives can be of
high-resistivity and should preferably have high resistivity.
Should more than one additive be added to a system at a time, the
additives should preferably work simultaneously and synergistically
to meet several goals related to safety and performance.
[0029] The additive can include a silane such as
dimethyldimethoxysilane, aminoethylaminopropyltrimethoxysilane,
aminopropyltrimethoxysilane, dimethyldimethoxysilane,
octylmethyldiethoxy silane, or vinyltrimethoxysilane, or a
combination thereof, which can be present in an amount between 0.1
and 1 weight percent of the total composition.
[0030] In one embodiment, the lubricant and the water scavenger can
be part of a leak detection dye composition that is introduced into
a climate control system or the water scavenger may be absent. The
climate control system can be a mobile, stationary, window air
conditioning system such as a hybrid or electric vehicle, portable,
residential, or commercial air conditioning system or any other
hermetic system that employs a refrigerant and a lubricant. After
the composition has been loaded into the climate control system,
the system can be operated to circulate the composition throughout
the system. The circulating refrigerant can also disperse the
composition throughout the system.
[0031] Typically the leak detection dye content of the system can
be below about 0.1 percent. After the dye has been allowed to
circulate within the system, the system joints, components, or
attachments can be examined with a light source having a wavelength
from 190 nanometers to 700 nanometers. The presence of a leak can
be determined by a colored visual indication such as fluorescence
or other light emission that can be detected after excitation with
the light from the light source. Alternatively, if the leak
detection composition includes a visible leak detection dye,
visible to the unaided eye, the presence of the leak can be
determined by visual inspection of the climate control system.
[0032] The leak detection dye composition that includes a lubricant
and a water scavenger can be supplied in the form of a pressurized
canister, a hose, a container, or any other fluid transfer or
storage apparatus. The refrigerant can include chlorofluorocarbons,
hydrochlorofluorocarbons, hydrofluorocarbons, carbon dioxide,
ammonia, halogenated or ether derivatives of methane or ethane, or
halogenated ether or cyclic derivatives of propane, butane, or
other hydrocarbons. Examples of a refrigerant include 1,1,1,2
tetrafluoroethane (R-134a, Honeywell), dichlorodifluoromethane
(R-12, DuPont, Wilmington, Del.) and experimental refrigerants such
as those under development by DuPont and Honeywell to replace
R-134a refrigerant. The lubricant can include polyalkylene glycols,
polyolesters, mineral oils, polyvinyl ethers, alkylbenzenes, or
other synthetic lubricating materials. The dye concentrate can
include leak detection dye such as a fluorescent dye. The
fluorescent dye can include a naphthalimide dye, a perylene dye, a
coumarin dye, a thioxane dye, a fluorescein dye, or a derivative
thereof or other dye compatible with a climate control systems. The
fluorescent dye can be liquid or solid, such as a powder. Examples
of suitable dyes include liquid dyes, for example, STAY-BRITE BSL
714 (Bright Solutions, Troy Mich.), DAY GLOW TRY-33 or TRY-53 (Day
Glow Color Corp, Cleveland, Ohio), R-12 Dye STAY-BRITE BSL713 (part
B713012), or R-134a Dye STAY-BRITE BSL712 (part B712012) or other
dyes. The dyes can include a POE lubricant such as B714012 or be a
so-called solvent-free dye such as B703012 (both from Bright
Solutions) which is composed of a dye and lubricant without any
further material amounts of another co-solvent. The dye can be
combined with a low conductivity lubricant, for example a PAG, POE
or PAO, and can also include a water scavenger in the formulation.
The formulation can be the result of a reaction, mixture or other
combination of constituents.
[0033] In one embodiment, the composition can be a combination of a
refrigerant, a lubricant, and a dye concentrate. The composition
can include, for example, a first weight amount of leak detection
dye concentrate, a second weight amount of lubricant and a third
weight amount of refrigerant. The first and second amounts together
can be greater than the third amount. See, for example, U.S. Pat.
No. 6,183,663, which is incorporated by reference in its
entirety.
[0034] The performance-enhancing product can extend the lifetime of
the system or give new life to bearings, seals, and all compressor
parts, increase cooling capacity, quiet compressor noise, or
decrease fuel consumption by reducing friction, thereby improving
the compressor's mechanical efficiency and lowering its power
consumption. The product may have the effect of reducing the
temperature that comes out of the vents. The product can coat the
parts better than existing lubricants resulting in longer life for
the compressor and certain components. See, for example, U.S. Pat.
No. 7,077,149, which is incorporated by reference in its
entirety.
[0035] To reduce the possibilities of cross contamination, the high
resistivity lubricant, such as a PAG, POE or PAO, can be
differentiated from other lubricants by a distinctive colorant or
an odorant. The colorant can be fluorescent. The colorant an be a
dye, a colorant or an optical brightener. Currently PAGs and POEs
are clear liquids, with the exception of at least one PAG which has
a blue color. The differentiating colorant can be of high
electrical resistivity. This visual differentiation should be
capable of distinguishing a high resistivity lubricant (with or
without additives) from a regular/low resistivity lubricant.
EXAMPLES
[0036] Experiments were conducted comparing Zerol RFL with ISO 100
Idemitsu dicapped PAG obtained from Idemitsu Lubricants America
Corporation (Jeffersonville, Ind.). FIG. 1 depicts the results from
a basic hygroscopicity test conducted at 80% relative humidity,
25.degree. C. and on 25 cm.sup.2 surface area. The test
demonstrates that Zerol RFL has lower water content than a dicapped
PAG from Idemitsu.
[0037] Further experiments were conducted to investigate the
influence of water content and TAN value on electrical resistivity
of dicapped PAGs. As shown in FIGS. 2A and B, extensive testing
demonstrated differences in resistivity between commercially
available dicapped PAGs. This can be attributed to additisation
type and production quality, for example residual catalyst rather
than differences in PAG structure. FIG. 2A is a graph that is
measured on samples which have a total acid number (TAN) (mgKOH/g)
set at 0.03 mgKOH/g. The effect of varying water content in these
samples is presented in the plot with resistivity decreasing as
expected when the water content increases. There is a marked
difference between Zerol RFL with ISO 100 Idemitsu dicapped PAG for
samples which have identical TAN and water content. However, this
is thought to be due to the salt content of the samples. Salt can
be a bi-product of PAG manufacture and samples which have higher
salt contents will show poorer electrical resistivity. FIG. 2B is a
graph that is measured on samples which have a water content set at
50 ppm. The effect of varying TAN in these samples is shown with
higher TAN and decreased resistivity. There is a difference between
Zerol RFL with ISO 100 Idemitsu dicapped PAG, particularly at low
TAN which is most likely due to salt content.
TABLE-US-00001 TABLE 1 Volume Dielectric Resistivity strength
Lubricant Type (ohm cm) (kV) POE (eg. ND11) 1.8 .times. 10.sup.14
44 Zerol HYPAG 46 1.06 .times. 10.sup.12 38 (50 ppm H.sub.2O) Zerol
RFL-X 8.7 .times. 10.sup.11 38 Standard dicapped PAG 3.2 .times.
10.sup.11 n/a (300 ppm H.sub.2O)
[0038] Table 1 is a comparison of different PAGs and their volume
resistivity and dielectric strength. As demonstrated, Zerol HYPAG
46 offers an optimized PAG basestock for R-134a systems, combined
with appropriate additisation technology, and can be manufactured
to the appropriate water specification to ensure optimized
electrical properties suitable for hybrid MAC systems.
[0039] FIG. 3 is a graph showing the results of a modified Falex
test (in R-134a atmosphere) showing the superiority of PAGs versus
POEs. The graph demonstrates that an oil can be defined in terms of
its block weight loss.
[0040] Other embodiments are within the claims.
* * * * *