BACKGROUND OF THE INVENTION
The subject matter disclosed herein relates to fluid (e.g., air) quality
monitoring and, in particular, to embodiments of a device for monitoring corrosive
contaminants in fluid that enters a turbo-machine.
Gas turbines, aero-derivatives, and other varieties of turbo-machinery use a
fluid inlet system that chaimels incoming fluid towards a compressor. The inlet system
can have a filter section to screen the fluid of foreign objects and other materials.
Typically, the inlet system and the compressor comprise metals that may corrode when
exposed to certain contaminants, which come from the environment in which the turbomachine
operates.
Some turbo-machines may develop microenvironments, e.g., areas of the
turbo-machine in which the fluid flows with different flow properties (e.g., velocity and
pressure). These flow properties can increase the rate of corrosion. Moreover, the
differences in the flow properties across the turbo-machine prevents the use of ambient
conditions to identify the rate of corrosion that will occxir throughout the various parts,
areas, and microenvironments. Rather, it is likely that techniques to determine the
environmental effects of the fluid on the turbo-machine, e.g., on the compressor
components, may necessarily monitor fluid downstream of the turbo-machine.
One technique to measure the rate of corrosion is to place strips (hereinafter
"coupons") in the stream of fluid. This configuration exposes the coupons to the fluid,
which may cause the coupons to corrode and fail. An end user (e.g., a technician) can
monitor the progress of corrosion and time to failure through, for example, periodic
visual examination of coupons. For more accurate determinations, however, the coupons
are sent to a lab for more time consuming and expensive testing to determine the type(s)
of corrosives that caused the failure.
Use of coupons can cause a few problems. For example, all or part of the
coupons may upon failure dislodge and become a projectile that can potentially cause
damage to the compressor components. The coupons may also create flow distortion
waves that can also damage turbo-machine components.
The discussion above is merely provided for general background information
and is not intended to be used as an aid in determining the scope of the claimed subject
matter.
BRIEF DESCRIPTION OF THE INVENTION
This disclosure describes embodiments of a device for monitoring corrosive
components suspended in fluid flowing to a turbo-machine. The device comprises an
elongated body member with test elements that have material properties responsive to the
corrosive components. In one example, the test elements comprise cylindrical tubes that
can slide onto the threaded rod. The assembly is positioned in flow streams and, more
particularly, finds particular use in the flow stream of fluid found in an inlet system that
couples with a turbine (e.g., a gas or steam turbine). An advantage that the practice of
some embodiments of the device is to provide a robust device to identify the presence
and/or absence of constituent components in the fluid, without having a detrimental or
adverse affect on the flow stream of fluid flowing to the turbo-machine.
The disclosure describes, in one embodiment, a corrosion monitoring device.
The corrosion monitoring device comprises an elongated body member having a central
axis and a test element disposed on the elongated member. The test element comprising a
material with properties that corrode in the presence of contaminants in a fluid.
The disclosure also describes, in one embodiment, a corrosion monitoring
device that comprises a threaded rod having a central axis. The corrosion monitoring
device also comprises a test element in surrounding relation to the threaded rod. The test
element comprises a first test element, a second test element, and a spacer assembly
disposed therebetween. The first test element and the second test element having
properties that corrode in the presence of contaminants in the fluid.
The disclosure further describes, in one embodiment, a system for generating
power. The system comprises a turbo-machine and an inlet system coupled to the turbomachine.
The inlet system directs fluid from the surrounding environment to the turbomachine.
The system also comprises a corrosion monitoring device coupled to a wall of
the inlet system. The corrosion monitoring device comprises an elongated body member
and a test element in surrounding relation to the elongated body member. In one
example, the test element projects into the inlet system to expose the test element to the
fluid flowing therein.
This brief description of the invention is intended only to provide a brief
overview of the subject matter disclosed herein according to one or more illustrative
embodiments, and does not serve as a guide to interpreting the claims or to define or limit
the scope of the invention, which is defined only by the appended claims. This brief
description is provided to introduce an illustrative selection of concepts in a simplified
form that are further described below in the detailed description. This brief description is
not intended to identify key features or essential features of the claimed subject matter,
nor is it intended to be used as an aid in determining the scope of the claimed subject
matter. The claimed subject matter is not limited to implementations that solve any or all
disadvantages noted in the background.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the features of the invention can be understood, a
detailed description of the invention may be had by reference to certain embodiments,
some of which are illustrated in the accompanying drawings. It is to be noted, however,
that the drawings illustrate only certain embodiments of this invention and are therefore
not to be considered limiting of its scope, for the scope of the invention encompasses
other equally effective embodiments. The drawings are not necessarily to scale,
emphasis generally being placed upon illustrating the features of certain embodiments of
the invention. In the drawings, like numerals are used to indicate like parts throughout
the various views. Thus, for further understanding of the invention, reference can be
made to the following detailed description, read in connection with the drawings in
which:
FIG. 1 depicts an exemplary corrosion monitoring device;
FIG. 2 illustrates one unplementation of the corrosion monitoring device of
FIG. 1 in an inlet system to a turbo-machine;
FIG. 3 depicts a front view of the inlet system of FIG. 2;
FIG. 4 depicts another exemplary corrosion monitoring device; and
FIG. 5 depicts details of the corrosion monitoring device of FIG. 4.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an exemplary corrosion monitoring device 100 (also "device
100") that is useful to detect corrosive contaminants in a fluid. The device 100 includes
an elongated body member 102 with a first end 104 and a second end 106. At the first
end 104, the device 100 includes a mounting element 108, which can secure the device
100 to a wall or other structure. The elongated body member 102 has a test element 112
that indicates the presence of corrosive contaminants, e.g., materials found in a fluid 114
that contacts the surface of the test element 112. In one example, the test element 112
includes a first test element 116, a second test element 118, a third test element 120 that
extend along a central axis 122. The test elements 116, 118, 120 can comprise materials
with properties that may react to certain contaminants present in tiie fluid 114. The type
of material can be pre-selected, e.g., in connection with an industry standard or other
factors that define the type of contaminants present or known to be present in the fluid
114. In one embodiment, the test elements 116, 118, 120 comprise different materials to
make the device 100 sensitive to several different types of contaminants in the fluid 114.
The elongated body member 102 can form a unitary and/or monolithic
structure which integrates the test elements 116,118,120 therein. The mounting element
108 can attach to this structure, thereby providmg one way to mount the elongated body
member 102 to any corresponding feature. In one alternative, the test elements 116, 118,
120 embody separate pieces that mount adjacent to one another. These separate pieces
can secure to one another, e.g., using threaded connectors, fasteners, and/or features on
the test elements 116, 118, 120 to secure the first test element 116 to the second test
element 118 and the second test element 118 to the third test element 120. As discussed
more below, the elongated body member 102 in other examples of the device 100 may
include a secondary piece that supports the test element 116,118,120 thereon.
Designs that form the test elements 116,118,120 as separate pieces afford the
device 100 with some level of flexibility to address different types of contaminants. For
example, the separate pieces can be removably replaceable from the device 100. This
construction permits the device 100 to be configured and re-configured with different
materials and/or reactive properties. In one implementation, a technician can remove the
device 100 from its position in a flow stream, examine the test elements 116, 118, 120,
and determine whether to replace one or more of the test elements 116, 118, 120 as
desired. The separate pieces are likewise amenable for transport (separate from, e.g., the
secondary piece and/or other parts of the device 100) to a remote location (e.g., a lab) for
more detailed testing and analysis. To continue monitoring and testing, however, the
technician can position new pieces that embody the test elements 116, 118, 120 as part of
the device 100 and, ultimately, re-install the device 100 into the flow stream.
As shown in FIG. 1, the surface of the elongated body member 102 forms a
profile with a curvilinear shape. This feature reduces the effect the corrosion monitoring
device 100 may have on the flow stream. For example, it is desirable that the elongated
body member 102 does not cause undue pressxire drop or induce other changes in the
flow stream when the corrosion monitoring device 100 is positioned in a turbo-machine
system. Examples of the profile can form the generally cylindrical shape shown in FIG.
1 or, in other embodiments, the profile can have other shapes, e.g., an airfoil shape, that
reduce drag of the elongated body member 102 on the fluid 114.
The mounting element 108 can support the elongated body member 102 in a
cantilevered configuration, with the first end 104 secxired proximate a structure and the
second end 106 left relatively imsupported. This configuration exposes of the test
elements 116, 118, 120 to the fluid 114. Examples of the mounting element 108 can
include nuts and threaded fasteners that engage a similarly threaded portion of the
elongated body member 102 at the first end 104. Selected fasteners (and threads) and
components of the mounting element 108 should secure the device 100 in a manner to
withstand vibration and other mechanical motion that might be present at the location of
the moimting location. This motion may occur as a result of operation of an asset (e.g., a
turbo-machine) as well as or in addition to motion the flow stream induces as the fluid
114 contacts the elongated body member 102. In one implementation, the moimting
element 108 also permits an end user (e.g., a technician) to rapidly mount and dismount
the device 100 firom the structure. This feature permits timely inspection of the test
elements 116, 118, 120 to determine, in one example, whether the fluid 114 causes
corrosion to form on the test element 112. Such corrosion, when considered in
combination with the properties (e.g., material properties) of the test element 116, 118,
120, can help to identify the types, levels, and other characteristics of contaminants in the
fluid 114.
FIGS. 2 and 3 depict one implementation of the contaminant monitoring
device 100 to detect and/or monitor constituent components (e.g., debris, moisture
droplets, etc.) found in fluid traveling to a turbo-machine 123. FIG. 2 shows a side view
of the turbo-machine 123 and an inlet system 124, which together form a turbo-machine
system that comprises structure to ensure an appropriate supply of fluid to the turbomachine
123. In one example, the device 100 mounts to a wall of the inlet system 124.
FIG. 3 shows a front view of the inlet system 124 taken at line A-A of FIG. 2. This view
illustrates the cantilevered configuration of the device 100 when in position in the inlet
system 123.
As shown in FIG. 2, a compressor 125 couples with the inlet system 124 to
move fluid through the inlet system 124 and into the turbo-machine 123. The device 100
couples with the structure of tiie inlet system 124 to expose the test element 112 to the
moving fluid. Depending on the level of detection required and other design
requirements, the inlet system 124 can accommodate one or more of the devices 100 at
various mounting or sampling locations (e.g., a first location 126, a second location 128,
a third location 130, a fourth location 132, and a fifth location 134).
The device 100 can help to reduce damage to the turbo-machine 123 by
monitoring contaminants foimd in fluid flowing through the inlet system 124. These
contaminants can damage parts of the turbo-machine 123, e.g., fan blades that rotate in
the path of the fluid during operation. The present design provides a low cost technique
to monitor and to identify the types of contaminants and concentration levels that are
present in the fluid and the environment in which the turbo-machine 123 is foimd.
Moreover, the device 100 can insert directly into the flow stream that forms in the interior
of the inlet system 124, permitting a more accurate measure of contaminants (as
compared to devices that draw off a sample of fluid to a remote measuring station)
without imduly obstructing the flow stream to the turbo-machine 123.
Continuing with the discussion of the inlet system 124, and moving from left
to right in the diagram of FIG. 2, in one example, the inlet system 124 includes a weather
hood 136 and an inlet filter housing 138. A cooling module 140 may be found inside of
the inlet filter housing 138. The cooling module 140 may include a washing system that
disperses fluid (e.g., water) into the inlet filter housing 138 to facilitate filtering of the
fluid flowing therethrough. A transition piece 142 couples the inlet filter housing 138 to
an inlet duct 144. The physical characteristics of these elements help to develop certain
flow characteristics (e.g., velocity, pressure, etc.) in the flow of fluid as the fluid transits
the inlet system 124 to the turbo-machine 123. Inside of inlet duct 144, the fluid can
encounter one or more other elements, e.g., a silencer section 146, heating system 148,
and screen element 150, which are useful for conditioning the fluid as the fluid travels
through the inlet system 124 to the turbo-machine 122.
As best shown in FIG. 3, the device 100 can extend through the wall (e.g., a
wall of the transition piece 142) and into the path of fluid in the inlet system 124. In one
implementation, a technician can secure the device 100 in place on the wall and/or at one
or more of the designated location(s) of the inlet system 124. To sunplify installation,
these locations can comprise an opening, aperture, and/or other feature to provide access
into the interior of the inlet system 124 from outside of the inlet system 124. In one
example, the technician can insert the second end 106 of the elongated body member 102
through the opening. The moimting element (e.g., mounting element 108 of Fig. 1) on
the first end 104 is secured to position the device 100 and to maintain the cantilevered
configuration (as shown in FIG. 3).
FIG. 4 illustrates another exemplary contaminant monitoring device 200 (also
"device 200") that can detect contaminants in fluid. These contaminants may cause
corrosion and/or degradation to appear on the device 200. In one embodiment, the device
200 has an elongated body member 202 with a threaded rod 252, which can comprise
threads that extend along its length or, in one example, along a portion at each of the
ends. Threaded fasteners (e.g., a first threaded fastener 254 and a second threaded
fastener 256) are foimd on either end of the threaded rod 252.
The device 200 also includes a test coupon 258, e.g., a cylinder or tube with a
hollow center that fits about the threaded rod 252. The cylinder can comprise materials
that react to contaminants present in fluid. Exemplary materials include carbon steels,
alloy steels, copper, aluminum, zinc, other alloys, and the like. In one embodiment, the
test coupon 258 sUdes onto the threaded rod 252. This feature allows the test coupon 258
to traverse the length of the threaded rod 252, which in turn permits the test coupon 258
to assume a variety of positions on the threaded rod 252. Although only one test coupon
258 is shown, this disclosure contemplates configurations of the device 200 with a
plurality of the test coupons 258 in position on the threaded rod 252. A configuration
with multiple test coupons 258 mimics the arrangement of test elements 116, 118 ,120
discussed in connection with FIG. 1 above.
The threaded rod 252 provides support for the test coupon 258. Examples of
the threaded rod 252 can embody elongated cylindrical shapes, as shown in FIG. 4, as
well as other any variety of shapes (e.g., roimd, square, and rectangular bar stock).
Selection of the shape and/or construction may depend on the particular application,
which may dictate specific design requirements (e.g., strength, length, etc.) for the
threaded rod 252. Exemplary materials for use in the threaded rod 252 include metals
(e.g., steels, aluminums) and/or other high-strength materials with rigidity sufficient to
withstand the velocity of fluid and other fluids, e.g., velocity typical of the turbo-machine
system discussed above. Materials may also be selected that are inert, or otherwise
chemically inactive, with the material(s) of the test coupons 258 to avoid inadvertent
contamination that can cause premature corrosion and/or reaction in the test coupons 258
contaminants in the fluid do not induce.
FIG. 5 shows details of the device 200 as indicated by Detail A of FIG. 4. In
one example, spacer assemblies (e.g., a first spacer assembly 260 and a second spacer
assembly 262) bound either side of the test coupon 258. The spacer assemblies 260, 262
can include a spacer (e.g., a first spacer 264 and a second spacer 266) and/or one or more
washers 268. A threaded nut 270 couples with end of the threaded rod 252 to retain all of
the components thereon. In one example, the device 200 can also have a protective
sleeve 272, which bounds at least a portion of the test coupon 258. Examples of the
protective sleeve 272 prevent material and debris that may shed fi-om the test coupon 258
fi-om traveling downstream to the turbo-machine. The protective sleeve 272 may
comprise mesh screen or other semi-porous material, which has properties that are
suitable to capture the debris but not to restrict the passage of fluid over and, in one
example, in contact with the surface of the test coupon 258.
10
Collectively, the assembly shown in the example of FIGS. 4 and 5 secures the
test coupons 258, and other components, onto the threaded rod 252. This configuration
prevents the test coupon 258 from becoming dislodged from the device 200. The spacer
assemblies 260, 262 separate the test coupon 258 from other test coupons (not shown)
that reside adjacent the test coupon 258 on the device 200. This configuration prevents
cross-contamination between the test coupons and ensure accurate test results.
Contamination can occur, for example, when coupons of different materials are in contact
with one another. Examples of the spacers 264, 266 can comprise polymer gaskets as
well as other inert materials (e.g., pljistics and composites). Like the spacers 264, 266,
the washers 268 can comprise polyamide and similar materials.
As used herein, an element or function recited in the singular and proceeded
with the word "a" or "an" should be understood as not excluding plural said elements or
functions, unless such exclusion is explicitly recited. Furthermore, references to "one
embodiment" of the claimed invention should not be interpreted as excluding the
existence of additional embodiments that also incorporate the recited features.
This written description uses examples to disclose the invention, including the
best mode, and also to enable any person skilled in the art to practice the invention,
including making and using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the claims, and may
include other examples that occur to those skilled in the art. Such other examples are
intended to be within the scope of the claims if they have structural elements that do not
differ from the literal language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal language of the claims.
11
GE256172;3054882US01
PARTS LIST
100
102
104
106
108
112
114
116
118
120
122
124
136
138
140
142
144
146
148
150
200
202
212
252
254
256
258
260
262
Corrosion monitoring device
Elongated body member
First end
Second end
Mounting element
Test element
Fluid
First test element
Second test element
Third test element
Central axis
Compressor
Weather hood
Inlet filter housing
Cooling module
Transition piece
Inlet duct
Silencer section
Heating system
Screen element
Monitoring device
Elongated body member
Test section
Threaded rod
First threaded fastener
Second threaded fastener
Test coupon
First spacer assembly
Second spacer assembly
264 First spacer
iXGE256172;
3054882US01
266 Second spacer
268 Washers
270 Threaded nut
272 Protective sleeve
rs

We Claim:
1. A corrosion monitoring device, comprising:
an elongated body member having a central axis; and
a test element disposed on the elongated member, the test element comprising a
material with properties that corrode in the presence of contaminants in a fluid.
2. The corrosion monitoring device of claim 1, wherein the test element
comprises a first test element and a second test element that comprise materials that
corrode in the presence of different contaminants.
3. The corrosion monitoring device of claim 2, wherein the first test element and
the second test element comprise cylindrical tubes.
4. The corrosion monitoring device of claim 1, wherein the elongated body has a
threaded portion on one end to receive a nut.
5. The corrosion monitoring device of claim 1, wherein the test element forms a
monolithic structure that extends along the central axis of the elongated body member.
6. The corrosion monitoring device of claim I, wherein the test element
comprises separate pieces that moimt adjacent to one another along the reactive portion.
7. The corrosion monitoring device of claim 6, wherein the separate pieces are
spaced apart fi-om one another with material inert to the material of the separate pieces.
8. The corrosion monitoring device of claim I, wherein the test element is
removably replaceable fi-om the elongated body member.
9. The corrosion monitoring device of claim 1, wherein the elongated body
member forms a profile with a curvilinear shape.
14
10. The corrosion monitoring device of claim 1, further comprising a protective
sleeve disposed in surrounding relation to the test element, the protective sleeve
comprising porous material.
11. A corrosion monitoring device, comprising:
a threaded rod having a central axis; and
a test element in surrounding relation to the threaded rod, the test element
comprising a first test element, a second test element, and a spacer assembly disposed
therebetween, the first test element and the second test element having properties that
corrode in the presence of contaminants in the fluid.
12. The corrosion monitoring device of claim 11, further comprismg a threaded
fastener disposed at a first end of the threaded rod.
13. The corrosion monitoring device of claim 11, wherein the first test element
and the second test element comprise a tube.
14. The corrosion monitoring device of claim 11, wherein the spacer assembly
comprises material that is different from the first test element and the second test
element.
15. The corrosion monitoring device of claim 11, wherein the spacer assembly
comprises a spacer and one or more washers.
16. A system for generating power, comprising:
a turbo-machine;
an inlet system coupled to the turbo-machine, the inlet system directing fluid from
the surrounding environment to the turbo-machine;
15
a corrosion monitoring device coupled to a wall of the inlet system, the corrosion
monitoring device comprising an elongated body member and a test element in
surrounding relation to the elongated body member, wherein the test element projects
into the inlet system to expose the test element to the fluid flowing therein.
17. The system of claim 16, wherein the test element comprises material that
corrodes in the presence of contaminants in the fluid.
18. The system of claim 16, wherein the corrosion monitoring device comprises a
threaded fastener that couples with the elongated body member to support the elongated
body member in a cantilevered configuration from the wall.
19. The system of claim 16, wherein the inlet system can accommodate more
than one of the corrosion monitoring device.
20. The system of claim 16, wherein the corrosion monitoring device moimts
downstream of the turbo-machine.