U.S. patent application number 14/594699 was filed with the patent office on 2016-06-09 for liquid refrigerant pumping system.
The applicant listed for this patent is Rudolf Hauleitner, George Lutzow, Guillermo Enrique Morales Espejel, John Travis Shive, Hans Wallin. Invention is credited to Rudolf Hauleitner, George Lutzow, Guillermo Enrique Morales Espejel, John Travis Shive, Hans Wallin.
Application Number | 20160160857 14/594699 |
Document ID | / |
Family ID | 56093929 |
Filed Date | 2016-06-09 |
United States Patent
Application |
20160160857 |
Kind Code |
A1 |
Wallin; Hans ; et
al. |
June 9, 2016 |
LIQUID REFRIGERANT PUMPING SYSTEM
Abstract
A lubricant supply system includes first and second tanks, each
including an internal volume that is divided into a first portion
and a second portion. The first portion of the internal volume of
the first tank and the first portion of the internal volume of the
second tank are configured to alternate supplying a liquid
refrigerant to a machine. A pump is in fluid communication with the
second portion of the internal volume of the first tank and the
second portion of the internal volume of the second tank. The pump
is configured to vary a pressure of a gas in the second portion of
the internal volume of the first tank and the second portion of the
internal volume of the second tank.
Inventors: |
Wallin; Hans; (Cape Coral,
FL) ; Lutzow; George; (Macungie, PA) ; Shive;
John Travis; (Telford, PA) ; Hauleitner; Rudolf;
(Steyr, AT) ; Morales Espejel; Guillermo Enrique;
(IJsselstein, NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wallin; Hans
Lutzow; George
Shive; John Travis
Hauleitner; Rudolf
Morales Espejel; Guillermo Enrique |
Cape Coral
Macungie
Telford
Steyr
IJsselstein |
FL
PA
PA |
US
US
US
AT
NL |
|
|
Family ID: |
56093929 |
Appl. No.: |
14/594699 |
Filed: |
January 12, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14561692 |
Dec 5, 2014 |
|
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14594699 |
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Current U.S.
Class: |
184/6.16 |
Current CPC
Class: |
F04B 43/06 20130101;
F25B 31/002 20130101; F25B 1/053 20130101; F04B 9/117 20130101;
F04D 29/063 20130101 |
International
Class: |
F04B 53/18 20060101
F04B053/18; F04B 53/08 20060101 F04B053/08 |
Claims
1. A lubricant supply system, comprising: a first tank defining an
internal volume that is divided into a first portion and a second
portion; a second tank defining an internal volume that is divided
into a first portion and a second portion, wherein the first
portion of the internal volume of the first tank and the first
portion of the internal volume of the second tank are configured to
alternate supplying a liquid refrigerant to a machine; and a pump
in fluid communication with the second portion of the internal
volume of the first tank and the second portion of the internal
volume of the second tank, wherein the pump is configured to vary a
pressure of a gas in the second portion of the internal volume of
the first tank and the second portion of the internal volume of the
second tank.
2. The lubricant supply system of claim 1, wherein the first
portion of the internal volume of the first tank and the first
portion of the internal volume of the second tank are configured to
be in fluid communication with a refrigeration chiller and to
receive the liquid refrigerant therefrom.
3. The lubricant supply system of claim 2, wherein the pump is
configured to transfer at least a portion of the gas from the
second portion of the internal volume of the first tank to the
second portion of the internal volume of the second tank, thereby
generating a pressure differential that draws the liquid
refrigerant from the refrigeration chiller into the first portion
of the internal volume of the first tank.
4. The lubricant supply system of claim 2, wherein the pump is
configured to transfer at least a portion of the gas back and forth
between the second portion of the internal volume of the first tank
and the second portion of the internal volume of the second
tank.
5. The lubricant supply system of claim 4, wherein the first
portion of the internal volume of the first tank and the first
portion of the internal volume of the first tank are configured to
alternate drawing the liquid refrigerant from the refrigeration
chiller based on operation of the pump.
6. The lubricant supply system of claim 1, wherein the pump
comprises: a first pump in fluid communication with the second
portion of the internal volume of the first tank; and a second pump
in fluid communication with the second portion of the internal
volume of the second tank.
7. The lubricant supply system of claim 1, wherein the first and
second portions of the internal volume of the first tank are
separated by a divider, and wherein the divider comprises a
diaphragm, a piston, or a bladder.
8. A lubricant supply system, comprising: a first tank defining an
internal volume that is divided into a first portion and a second
portion; a second tank defining an internal volume that is divided
into a first portion and a second portion; a refrigeration chiller
including an evaporator and a condenser; a valve in fluid
communication with the first portion of the internal volume of the
first tank, the evaporator, and the condenser, wherein the valve
provides a path of fluid communication from the evaporator to the
first portion of the internal volume of the first tank when the
valve is in a first position, and wherein the valve provides a path
of fluid communication from the condenser to the first portion of
the internal volume of the first tank when the valve is in a second
position; and a pump in fluid communication with the second portion
of the internal volume of the first tank and the second portion of
the internal volume of the second tank, wherein the pump is
configured to vary a pressure of a gas in the second portion of the
internal volume of the first tank and the second portion of the
internal volume of the second tank.
9. The lubricant supply system of claim 8, wherein the pump is
configured to simultaneously increase the pressure of the gas in
the second portion of the internal volume of the first tank and
decrease the pressure of the gas in the second portion of the
internal volume of the second tank.
10. The lubricant supply system of claim 9, wherein the increased
pressure in the second portion of the internal volume of the first
tank causes a liquid refrigerant to flow from the first portion of
the internal volume of the first tank to one or more bearings in a
compressor in the refrigeration chiller.
11. The lubricant supply system of claim 10, wherein the decreased
pressure in the second portion of the internal volume of the second
tank causes additional liquid refrigerant to be drawn into the
first portion of the internal volume of the second tank from the
evaporator or the condenser.
12. The lubricant supply system of claim 11, wherein the pump is
configured to transfer at least a portion of the gas back and forth
between the second portion of the internal volume of the first tank
and the second portion of the internal volume of the second
tank.
13. The lubricant supply system of claim 11, wherein the pump
comprises: a first pump in fluid communication with the second
portion of the internal volume of the first tank; and a second pump
in fluid communication with the second portion of the internal
volume of the second tank.
14. A method for supplying a liquid refrigerant to a machine,
comprising: causing a pressure of a gas in a first tank to
decrease, which draws a liquid refrigerant into the first tank from
a refrigeration chiller; causing a pressure of a gas in second
first tank to decrease, which draws additional liquid refrigerant
into the second tank from the refrigeration chiller; and causing
the pressure of the gas in the first tank to increase
simultaneously with the pressure of the gas in the second tank
decreasing, which causes the liquid refrigerant to flow from the
first tank to a bearing in a compressor in the refrigeration
chiller.
15. The method of claim 14, further comprising causing the pressure
of the gas in the second tank to increase simultaneously with the
pressure of the gas in the first tank decreasing, which causes the
additional liquid refrigerant to flow from the second tank to the
bearing in the compressor.
16. The method of claim 14, wherein a pump causes the pressure of
the gas in the first tank to increase simultaneously with the
pressure of the gas in the second tank decreasing by transferring
at least a portion of the gas in the first tank to the second
tank.
17. The method of claim 14, further comprising actuating a valve
from a first position to a second position, wherein the liquid
refrigerant flows from an evaporator of the refrigeration chiller,
through the valve, and to the first tank when the valve is in the
first position, and wherein the liquid refrigerant flows from a
condenser of the refrigeration chiller, through the valve, and to
the first tank when the valve is in the second position.
18. The method of claim 14, wherein the first and second tanks
alternate supplying the liquid refrigerant and the additional
liquid refrigerant to the bearing in the compressor.
19. The method of claim 14, further comprising closing a shut-off
valve positioned proximate to an opening in the first tank through
which the liquid refrigerant flows before the pressure of the gas
in the first tank decreases.
20. The method of claim 14, wherein the gas in the first tank and
the liquid refrigerant in the first tank are separated by a
divider, and wherein the divider comprises a diaphragm, a piston,
or a bladder.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 14/561,692, filed on Dec. 5, 2014, the
entirety of which is incorporated herein by reference.
BACKGROUND
[0002] A centrifugal compressor includes one or more impellers that
compress a fluid. The impellers are mounted on a rotating shaft
which is supported by a plurality of bearings. The bearings require
a steady supply of lubricant, which is oftentimes oil. However, in
some recent applications, refrigerant has been used to lubricate
the bearings rather than oil. Refrigerant lubrication can be used
when, for example, the compressor is part of a refrigeration
chiller. A refrigeration chiller removes heat from a liquid via a
vapor-compression or absorption refrigeration cycle. The cooled
liquid may then be used to cool air (e.g., air conditioning) or in
an industrial process.
[0003] A pump can be used to make the refrigerant to flow to the
bearings. The pump may cavitate making it more difficult to supply
the refrigerant to the bearings. There can also be operating
conditions under which the supply of refrigerant is in inadequate
supply or the state of the refrigerant is a mix of liquid and vapor
such that it is unable to properly lubricate the bearings.
Therefore, what is needed is a backup lubricant supply system that
is capable of providing lubricant (e.g., refrigerant) to the
bearings when the primary lubricant supply system is unable to
lubricate the bearings.
SUMMARY
[0004] A lubricant supply system is disclosed. The lubricant supply
system includes first and second tanks, each including an internal
volume that is divided into a first portion and a second portion.
The first portion of the internal volume of the first tank and the
first portion of the internal volume of the second tank are
configured to alternate supplying a liquid refrigerant to a
machine. A pump is in fluid communication with the second portion
of the internal volume of the first tank and the second portion of
the internal volume of the second tank. The pump is configured to
vary a pressure of a gas in the second portion of the internal
volume of the first tank and the second portion of the internal
volume of the second tank.
[0005] In another embodiment, the lubricant supply system includes
first and second tanks, each including an internal volume that is
divided into a first portion and a second portion. The system also
includes a refrigeration chiller including an evaporator and a
condenser. A valve is in fluid communication with the first portion
of the internal volume of the first tank, the evaporator, and the
condenser. The valve provides a path of fluid communication from
the evaporator to the first portion of the internal volume of the
first tank when the valve is in a first position, and the valve
provides a path of fluid communication from the condenser to the
first portion of the internal volume of the first tank when the
valve is in a second position. A pump is in fluid communication
with the second portion of the internal volume of the first tank
and the second portion of the internal volume of the second tank.
The pump is configured to vary a pressure of a gas in the second
portion of the internal volume of the first tank and the second
portion of the internal volume of the second tank.
[0006] A method for supplying a liquid refrigerant to a machine is
also disclosed. The method includes causing a pressure of a gas in
a first tank to decrease, which draws a liquid refrigerant into the
first tank from a refrigeration chiller. A pressure of a gas in
second first tank may be caused to decrease, which draws additional
liquid refrigerant into the second tank from the refrigeration
chiller. The pressure of the gas in the first tank may be caused to
increase simultaneously with the pressure of the gas in the second
tank decreasing, which causes the liquid refrigerant to flow from
the first tank to a bearing in a compressor in the refrigeration
chiller.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings, which are incorporated in and
constitutes a part of this specification, illustrates an embodiment
of the present teachings and together with the description, serves
to explain the principles of the present teachings. In the
figures:
[0008] FIG. 1 illustrates a schematic view of a system for
supplying a lubricant to a machine, according to an embodiment.
[0009] FIG. 2 illustrates a schematic view of the system showing
the divider as a piston, according to an embodiment.
[0010] FIG. 3 illustrates a schematic view of the system showing
the divider as a bladder, according to an embodiment.
[0011] FIG. 4 illustrates a flowchart of a method for providing
lubrication to a machine, according to an embodiment.
[0012] FIG. 5 illustrates a schematic view of another system for
supplying lubricant to a machine, according to an embodiment.
[0013] FIG. 6 illustrates another flowchart of a method for
providing lubrication to a machine, according to an embodiment.
[0014] It should be noted that some details of the figures have
been simplified and are drawn to facilitate understanding of the
embodiments rather than to maintain strict structural accuracy,
detail, and scale.
DETAILED DESCRIPTION
[0015] Reference will now be made in detail to embodiments of the
present teachings, examples of which are illustrated in the
accompanying drawing. In the drawings, like reference numerals have
been used throughout to designate identical elements, where
convenient. In the following description, reference is made to the
accompanying drawings that form a part of the description, and in
which is shown by way of illustration one or more specific example
embodiments in which the present teachings may be practiced.
[0016] Further, notwithstanding that the numerical ranges and
parameters setting forth the broad scope of the disclosure are
approximations, the numerical values set forth in the specific
examples are reported as precisely as possible. Any numerical
value, however, inherently contains certain errors necessarily
resulting from the standard deviation found in their respective
testing measurements. Moreover, all ranges disclosed herein are to
be understood to encompass any and all sub-ranges subsumed
therein.
[0017] Additionally, when referring to a position or direction in a
well, the terms "above," "up," "upward," "ascend," and various
grammatical equivalents thereof may be used to refer to a position
in a well that is closer to the surface than another position, or a
movement or direction proceeding toward the surface (topside),
without regard as to whether the well is vertical, deviated, or
horizontal. Similarly, when referring to a position in a well, the
terms "below," "down," "downward," and "descend" and various
grammatical equivalents thereof may be used to refer to a position
in a well that is farther from the surface than another position,
or a direction or movement proceeding away from the surface,
regardless of whether the well is vertical, deviated, or
horizontal. Moreover, the terms "upper," "lower," "above," and
"below," when referring to components of an apparatus, are used to
conveniently refer to the relative positioning of components or
elements, e.g., as illustrated in the drawings, and may not refer
to any particular frame of reference. Thus, a component may be
flipped or viewed in any direction, while parts thereof may remain
unchanged in terms of being "upper" or "lower" etc.
[0018] FIG. 1 illustrates a schematic view of a system 100 for
supplying a lubricant to a machine 160, according to an embodiment.
The system 100 may include a tank 110 that defines an internal
volume. A divider 112 may be positioned in the internal volume of
the tank 110 that divides or separates the internal volume into two
or more portions (two are shown: 114, 116). As shown, the divider
112 may be a diaphragm that is coupled to the inner surface of the
tank 110. The diaphragm 112 may be made of a material that is
configured to bend or flex as the first portion of the internal
volume 114 increases and decreases in response to a pressure
differential between the first and second portions of the internal
volume 114, 116.
[0019] The tank 110 may have one or more openings (four are shown:
122, 132, 142, 152) that provide a path of fluid communication
between the internal volume and the exterior of the tank 110. A
first pump 120 (referred to hereafter as a liquid pump) may be in
fluid communication with the first portion of the internal volume
114 of the tank 110 through a first one of the openings 122. As
used herein, the term "pump" refers to all machines operable to
increase and/or decrease a pressure in any type of fluid, whether
gas, liquid, or a combination thereof. The liquid pump 120 may be
used to introduce a liquid lubricant into the first portion of the
internal volume 114 of the tank 110. The lubricant may be an oil or
a refrigerant. Illustrative refrigerants may include R-134a, R-123,
R-1233zd, R-1234ze, and the like. To prevent lubricant from flowing
back through the liquid pump 120, a check valve may be positioned
at the discharge end of the liquid pump 120. Alternatively, with
the liquid pump 120 running, lubricant cannot flow back through the
liquid pump 120.
[0020] A valve 130 may be in fluid communication with the second
portion of the internal volume 116 of the tank 110 through a second
one of the openings 132. The valve 130 may be used to allow gas to
discharge (i.e. "bleed off") from the second portion of the
internal volume 116 of the tank 110 when the lubricant is being
introduced into the first portion of the internal volume 114.
[0021] A second pump 140 (referred to hereafter as a vacuum pump)
may be in fluid communication with the second portion of the
internal volume 116 of the tank 110 through a third one of the
openings 142. The vacuum pump 140 may be used to withdraw the gas
from the second portion of the internal volume 116 to reduce the
pressure of the gas and leave behind a partial vacuum.
[0022] A third pump 150 (referred to hereafter as a gas pump) may
be in fluid communication with the second portion of the internal
volume 116 of the tank 110 through a fourth one of the openings
152. The gas pump 150 may be used to introduce a gas into the
second portion of the internal volume 116 of the tank 110. As such,
the gas pump 150 may be or include a compressor. The gas may be
air.
[0023] Referring again to the first opening 122 in the tank 110,
the first opening 122 may also be in fluid communication with a
machine 160 via a conduit 162. In at least one embodiment, a valve
124 may be positioned in the conduit 162 between the tank 110 and
the machine 160. A sensor (not shown) may be configured to sense
when the lubricant supply to the machine 160 (e.g., from a primary
lubricant supply system) is insufficient. When this occurs, the
valve 124 may be switched from a closed position to an open
position (e.g., manually or automatically) to supply the lubricant
from the tank 110 to the machine 160.
[0024] The machine 160 may be any machine having relative movement
between two or more components. As shown, the machine 160 is a
centrifugal compressor in a chiller (e.g., a refrigeration
chiller). The "chiller" removes heat from a liquid (e.g., liquid
refrigerant lubricant) via a vapor-compression cycle or an
absorption refrigeration cycle. For example, the liquid refrigerant
lubricant may flow through an evaporator of the chiller where heat
is transferred to a first heat transfer fluid. The first heat
transfer fluid may flow through machine (e.g., compressor) 160
where the pressure may be increased. The first heat transfer fluid
(now compressed) may then be introduced to a condenser of the
chiller where the heat is transferred from the first heat transfer
fluid to a second heat transfer fluid. The liquid refrigerant
lubricant may be discharged from the evaporator and be circulated
through a heat exchanger to cool air or equipment as desired. In
another embodiment, the liquid refrigerant lubricant may be
discharged from the condenser of the chiller depending on the
operating conditions of the compressor chiller 160 and the state of
the refrigerant.
[0025] As shown, the machine (e.g., compressor) 160 may include at
least one impeller 170. The machine (e.g., compressor) 160 may
include a shaft 172 that is configured to rotate about a central
longitudinal axis 174. The shaft 172 may be supported by one or
more bearings (four are shown: 176). The bearings 176 may each
include an inner ring or "race" 178, an outer ring or race 180, and
one or more rolling elements (e.g., balls) 182 positioned
therebetween. As described in greater detail below, the liquid
refrigerant lubricant may flow from the first portion of the
internal volume 114 of the tank 110 and be introduced to the
bearings 176 (e.g., between the inner and outer rings 178, 180). In
some embodiments, the bearings 176 may have steel or ceramic
rolling elements.
[0026] FIG. 2 illustrates a schematic view of the system 100
showing the divider 112 as a piston, according to an embodiment. In
at least one embodiment, rather than the divider 112 being a
diaphragm (as shown in FIG. 1), the divider 112 may be a piston (as
shown in FIG. 2). The piston 212 may be positioned within the tank
110 and divide or separate the internal volume into the two
portions 114, 116. The piston 212 may be configured to move within
the tank 110 as the first portion of the internal volume 114
increases and decreases in response to a pressure differential
between the first and second portions of the internal volume 114,
116. For example, the piston 212 may move in a first axial
direction 214 (e.g., down as shown in FIG. 2) when the pressure of
the gas in the second portion of the internal volume 116 is greater
than the pressure of the lubricant in the first portion of the
internal volume 114. Similarly, the piston 212 may move in a second
axial direction 216 (e.g., up as shown in FIG. 2) when the pressure
of the lubricant in the first portion of the internal volume 114 is
greater than the pressure of the gas in the second portion of the
internal volume 116.
[0027] FIG. 3 illustrates a schematic view of the system 100
showing the divider 112 as a bladder, according to an embodiment.
In at least one embodiment, rather than the divider 112 being a
diaphragm (as shown in FIG. 1) or a piston (as shown in FIG. 2),
the divider 112 may be a bladder (as shown in FIG. 3). The bladder
312 may be positioned within the tank 110 and divide or separate
the internal volume into the two portions 114, 116. More
particularly, the bladder 312 may include a flexible "bag" that
defines an internal volume that is configured to receive the
lubricant. In at least one embodiment, the bladder 312 may be made
from a polymer or elastomer (e.g., rubber). The bladder 312 may
include an opening that is in fluid communication with the first
opening 122 in the tank 110.
[0028] With continuing reference to FIGS. 1-3, FIG. 4 illustrates a
flowchart of a method 400 for providing lubrication to a machine,
according to an embodiment. The method 400 may proceed by operation
of an embodiment of the system 100, for example, and may thus be
best understood with reference thereto. However, it will be
appreciated that the method 400 is not limited to any particular
structure unless otherwise stated herein. In addition, the steps
below may be conducted in any order, and the order described below
is for illustrative purposes only.
[0029] The method 400 may include introducing a lubricant (e.g., a
refrigerant) into a first portion of an internal volume of a tank,
as at 402. In one embodiment, the lubricant may be pumped into the
first portion of the internal volume with a first or "liquid" pump.
A valve that is in fluid communication with a second portion of the
internal volume of the tank may be open as the lubricant is pumped
into the first portion of the internal volume of the tank. This may
allow a gas within the second portion of the internal volume to
discharge from the second portion of the internal volume to make
room for the lubricant in the first portion of the internal volume.
The valve may be closed once the lubricant is stored in the first
portion of the internal volume.
[0030] In another embodiment, instead of, or in addition to, using
the liquid pump to introduce the lubricant into the first portion
of the internal volume, a second or "vacuum" pump may withdraw at
least a portion of the gas from the second portion of the internal
volume, leaving behind a partial vacuum in the second portion of
the internal volume. This partial vacuum may draw the lubricant
into the first portion of the internal volume.
[0031] The method 400 may also include increasing a pressure of the
gas in the second portion of the internal volume of the tank, as at
404. In one embodiment, additional gas (e.g., air) may be pumped
into the second portion of the internal volume with a third or
"gas" pump to increase the pressure in the second portion of the
internal volume. The gas pump may be controlled to maintain a
predetermined pressure in the first portion of the internal volume
and/or the second portion of the internal volume. For example, the
pressurized gas in the second portion of the internal volume may
exert a force on the lubricant in the first portion of the internal
volume via a diaphragm, a piston, a bladder, or the like positioned
between the first and second portions. This may cause the pressure
of the lubricant in the first portion of the internal volume to
increase, and the pressure may be maintained at this level until
the lubricant is released to a machine, as discussed below. In one
embodiment, the vacuum and gas pumps may be a single pump that
includes a switch at the inlet and outlet sides so that it may
serve to increase and decrease the pressure of the gas based on the
position of the switch.
[0032] The method 400 may also include supplying the lubricant from
the tank to a machine, as at 406. More particularly, a sensor may
sense when the lubricant supplied to the machine (e.g., from a
primary lubrication system) is insufficient. When this occurs, a
valve positioned between the tank and the machine may be switched
to an open position, and the (now pressurized) lubricant may flow
through the valve and to the machine. The lubricant may be supplied
to one or more bearings in the machine. By using back pressure to
facilitate the flow of the lubricant, the lubricant may flow easier
than when compared to a conventional gravity-fed system. In
addition, by using back pressure, the lubricant may be supplied in
a sub-cooled liquid state.
[0033] FIG. 5 illustrates a schematic view of another system 500
for supplying lubricant to the machine 160, according to an
embodiment. The system 500 may include one or more accumulator
tanks (two are shown 510, 550 that each define an internal volume.
The first tank 510 may have a divider 512 positioned in the
internal volume that divides or separates the internal volume into
two or more portions (two are shown: 514, 516). Similarly, the
second tank 550 may have a divider 552 positioned in the internal
volume that divides or separates the internal volume into two or
more portions (two are shown: 554, 556). The dividers 512, 552 may
be diaphragms, pistons, bladders, or the like.
[0034] The first portion of the internal volume 514 of the first
tank 510 may be in fluid communication with a refrigeration chiller
502 and configured to receive lubricant therefrom. The lubricant
may be oil or a liquid refrigerant. In at least one embodiment, a
valve 520 may be positioned between the refrigeration chiller 502
and the first tank 510. As shown, the valve 520 may be a three way
valve that is in fluid communication with the first portion of the
internal volume 514 of the first tank 510, an evaporator 504 of the
refrigeration chiller 502, and a condenser 506 of the refrigeration
chiller 502. When the valve 520 is in a first position, a path of
fluid communication may exist from the evaporator 504, through the
valve 520, and to the first portion of the internal volume 514 of
the first tank 510. When the valve 520 is in a second position, a
path of fluid communication may exist from the condenser 506,
through the valve 520, and to the first portion of the internal
volume 514 of the first tank 510. A check valve 522 may also be
positioned between the refrigeration chiller 502 and the first tank
510. The check valve 522 may allow the lubricant to flow from the
refrigeration chiller 502 to the first tank 510, but not from the
first tank 510 to the refrigeration chiller 502.
[0035] The first portion of the internal volume 514 of the first
tank 510 may also be in fluid communication with the machine (e.g.,
compressor) 160 in the refrigeration chiller 502. More
particularly, the lubricant may be supplied from the first portion
of the internal volume 514 of the first tank 510 to the bearings
176 of the machine 160. A check valve 524 may be positioned between
the first tank 510 and the machine 160. The check valve 524 may
allow the lubricant to flow from the first portion of the internal
volume 514 of the first tank 510 to the machine 160, but not from
the machine 160 to the first portion of the internal volume 514 of
the first tank 510. In at least one embodiment, a shut-off valve
526 may also be positioned between the first portion of the
internal volume 514 of the first tank 510 and the refrigeration
chiller 502, between the first portion of the internal volume 514
of the first tank 510 and the machine 160, or both.
[0036] The first portion of the internal volume 554 of the second
tank 550 may also be in fluid communication with the refrigeration
chiller 502 and configured to receive lubricant therefrom. In at
least one embodiment, a valve 560 may be positioned between the
refrigeration chiller 502 and the second tank 550. As shown, the
valve 560 may be a three way valve that is in fluid communication
with the first portion of the internal volume 554 of the first tank
550, the evaporator 504 of the refrigeration chiller 502, and the
condenser 506 of the refrigeration chiller 502. When the valve 560
is in a first position, a path of fluid communication may exist
from the evaporator 504, through the valve 560, and to the first
portion of the internal volume 554 of the second tank 550. When the
valve 560 is in a second position, a path of fluid communication
may exist from the condenser 506, through the valve 560, and to the
first portion of the internal volume 554 of the second tank 550. A
check valve 562 may also be positioned between the refrigeration
chiller 502 and the second tank 550. The check valve 562 may allow
the lubricant to flow from the refrigeration chiller 502 to second
first tank 550, but not from the second tank 550 to the
refrigeration chiller 502.
[0037] The first portion of the internal volume 554 of the second
tank 550 may also be in fluid communication with the machine (e.g.,
compressor) 160. More particularly, the lubricant may be supplied
from the first portion of the internal volume 554 of the second
tank 550 to the bearings 176 of the machine 160. A check valve 564
may be positioned between the second tank 550 and the machine 160.
The check valve 564 may allow the lubricant to flow from the first
portion of the internal volume 554 of the second tank 550 to the
machine 160, but not from the machine 160 to the first portion of
the internal volume 554 of the second tank 550. In at least one
embodiment, a shut-off valve 566 may also be positioned between the
first portion of the internal volume 554 of the second tank 550 and
the refrigeration chiller 502, between the first portion of the
internal volume 554 of the second tank 550 and the machine 160, or
both.
[0038] A pump 570 may be in fluid communication with the second
portion of the internal volume 516 of the first tank 510 and the
second portion of the internal volume 556 of the second tank 550.
The pump 570 may be used to vary a pressure of a gas into the
second portion of the internal volume 516 of the first tank 510 and
the second portion of the internal volume 556 of the second tank
550. More particularly, the pump 570 may be used to transfer a gas
back and forth between the second portion of the internal volume
516 of the first tank 510 and the second portion of the internal
volume 556 of the second tank 550. As such, the pump 570 may be or
include a compressor. The gas may be nitrogen or air. When the pump
570 is operating in a substantially closed circuit between the
first and second tanks 510, 550, as described above, gas may be
added to the circuit to offset any leakage.
[0039] To prevent lubricant from flowing back through the pump 570,
a check valve may be positioned at the discharge end of the pump
570. Alternatively, with the pump 570 running, lubricant cannot
flow back through the pump 570. In at least one embodiment, the
pump 570 may be or include first and second pumps where the first
pump is in fluid communication with the second portion of the
internal volume 516 of the first tank 510, and the second pump is
in fluid communication with the second portion of the internal
volume 556 of the second tank 550.
[0040] With continuing reference to FIG. 5, FIG. 6 illustrates a
flowchart of a method 600 for providing lubrication to a machine,
according to an embodiment. The method 600 may proceed by operation
of an embodiment of the system 500, for example, and may thus be
best understood with reference thereto. However, it will be
appreciated that the method 600 is not limited to any particular
structure unless otherwise stated herein. In addition, the steps
below may be conducted in any order, and the order described below
is for illustrative purposes only.
[0041] The method 600 may include pumping gas (e.g., nitrogen) from
the second portion of the internal volume 516 of the first tank 510
to the second portion of the internal volume 556 of the second tank
550 using the pump 570, as at 602. This may cause the pressure in
the first tank 510 to decrease. The shut-off valve 526 proximate to
the first tank 510 may be opened, allowing lubricant to be drawn
into the first portion of the internal volume 514 of the first tank
510 from the evaporator 504 of the refrigeration chiller 502, as at
604. Once a predetermined amount of the lubricant is within the
first portion of the internal volume 514 of the first tank 510
(e.g., filling about 50% of the first tank 510), the shut-off valve
526 proximate to the first tank 510 may be closed, as at 606.
[0042] The pump 570 may then reverse direction by pumping at least
a portion of the gas from the second portion of the internal volume
556 of the second tank 550 into the second portion of the internal
volume 516 of the first tank 510, as at 608. This may cause the
pressure in the second tank 550 to decrease. The shut-off valve 566
proximate to the second tank 550 may be opened, allowing additional
lubricant to be drawn into the first portion of the internal volume
554 of the second tank 550, as at 610. Once a predetermined amount
of the lubricant is within the first portion of the internal volume
554 of the second tank 550 (e.g., filling about 50% of the second
tank 550), the shut-off valve 566 proximate to the second tank 550
may be closed, as at 612.
[0043] The system 500 is now ready to lubricate the bearings 176 of
the machine (e.g., compressor) 160. The shut-off valve 526
proximate to the first tank 510 may be opened, as at 614. The
pressurized gas in the second portion of the internal volume 516 of
the first tank 510 may exert a force on the divider 512, causing
the lubricant to flow from the first portion of the internal volume
514 of the first tank 510 to the bearings 176 of the machine 160.
The pump 570 may cause an additional portion of the gas to flow
from the second portion of the internal volume 556 of the second
tank 550 to the second portion of the internal volume 516 of the
first tank 510, as at 616. This may maintain or increase the
pressure in the first tank 510 so that the lubricant may continue
to flow to the bearings 176.
[0044] When the lubricant in the first portion of the internal
volume 514 of the first tank 510 drops below a predetermined amount
(e.g., less than 10% of the first tank 510 contains lubricant), the
pump 570 may reverse direction and transfer at least a portion of
the gas from the second portion of the internal volume 516 of the
first tank 510 to the second portion of the internal volume 556 of
the second tank 550, as at 618. The shut-off valve 526 proximate to
the first tank 510 may be closed, and the shut-off valve 566
proximate to the second tank 550 may be opened, as at 620. The
pressurized gas in the second portion of the internal volume 556 of
the second tank 550 may cause the lubricant to flow from the first
portion of the internal volume 554 of the second tank 550 to the
bearings 176 of the machine 160.
[0045] The method 600 may loop back to block 604 where the shut-off
valve 526 proximate to the first tank 510 may be opened again,
allowing additional lubricant to be drawn into the first portion of
the internal volume 514 of the first tank 510 from the evaporator
504 (e.g., simultaneously with lubricant flowing from the second
tank 550 to the bearings 176 of the machine 160). Thus, the tanks
510, 550 may alternate receiving the lubricant from the evaporator
504, and the bearings 176 of the machine 160 may alternate
receiving the lubricant from the tanks 510, 550.
[0046] The first and second tanks 510, 550 may initially (e.g.,
during start-up) draw in the lubricant from the evaporator 504 of
the refrigeration chiller 502. Once the refrigeration chiller 502
reaches steady state conditions, the valves 520, 560 may be
switched to the second position such that the first and second
tanks 510, 550 may draw in the lubricant from the condenser 506 of
the refrigeration chiller 502.
[0047] While the present teachings have been illustrated with
respect to one or more implementations, alterations and/or
modifications may be made to the illustrated examples without
departing from the spirit and scope of the appended claims. In
addition, while a particular feature of the present teachings may
have been disclosed with respect to only one of several
implementations, such feature may be combined with one or more
other features of the other implementations as may be desired and
advantageous for any given or particular function. Furthermore, to
the extent that the terms "including," "includes," "having," "has,"
"with," or variants thereof are used in either the detailed
description and the claims, such terms are intended to be inclusive
in a manner similar to the term "comprising." Further, in the
discussion and claims herein, the term "about" indicates that the
value listed may be somewhat altered, as long as the alteration
does not result in nonconformance of the process or structure to
the illustrated embodiment. Finally, "exemplary" indicates the
description is used as an example, rather than implying that it is
an ideal.
[0048] Other embodiments of the present teachings will be apparent
to those skilled in the art from consideration of the specification
and practice of the present teachings disclosed herein. It is
intended that the specification and examples be considered as
exemplary only, with a true scope and spirit of the present
teachings being indicated by the following claims.
* * * * *