Heat exchanger with internal sensor grid and restrictors for sensor wires and heat exchange tubes

Abstract

The invention is entitled "Heat exchanger with internal sensor grid and restrictor for sensor wires and heat exchange tubes." The invention discloses a heat exchanger (108) comprising a sensor grid (180) having sensor leads (184) extending through a tube restrictor (190) for heat exchange tubes (146) in the heat exchanger (108). The tube restrictor (190) comprises a body (192) having a plurality of tube openings (194) defined therein, wherein each tube opening (194) receives one heat exchange tube from a group of heat exchange tubes (146) therethrough. The body (192) further comprises sensor lead openings (200) defined therein to receive the sensor leads (184) therethrough. Each tube opening (194) has a larger size than the sensor lead opening (200). The sensor grid (180) is installed during manufacturing rather than in the field, allowing the sensor grid (180) to be located on the outermost set of heat exchange tubes and the inner set (176) of heat exchange tubes (146) in the heat exchanger (108).

Description

Technical Field

[0001] The present disclosure relates generally to heat exchangers and, more particularly, to a heat exchanger including a sensor grid having one or more sensor leads extending through one or more openings in a tube restrictor for heat exchange tubes in the heat exchanger. The sensor grid is installed during manufacturing rather than in the field, allowing the sensor grid to be located on both the outermost and inner groups of heat exchange tubes in the heat exchanger. Background Art

[0002] A countercurrent heat exchanger includes multiple rows of heat exchange tubes that are immediately adjacent to each other. While applicable to any heat exchanger, to illustrate the challenges and benefits of embodiments of the present disclosure, the present disclosure will consider a heat exchanger in the form of a heat recovery steam generator (HRSG) in a combined cycle power plant (CCPP), which includes a gas turbine (GT) system and a steam turbine (ST) system. In this setting, the efficiency of the HRSG varies due to multiple operating parameters. In the CCPP example, the heat input may vary due to operating parameters such as, but not limited to: GT system load, ambient temperature, GT system degradation, GT system modifications / upgrades, duct burner load, and deviations between expected and actual operation. Similarly, the heat exchange efficiency within the HRSG may vary due to operating parameters of the HRSG, such as its cleanliness.

[0003] Managing the operation of CCPPs and heat exchangers to achieve high-efficiency performance requires the use of sensors within the heat exchangers to measure various operating parameters of the heat exchange process, such as, but not limited to, temperature, pressure, flow rate, and the like. Current practice is to install a grid of sensors on the outermost rows of heat exchange tubes of a HRSG in the field (i.e., after the HRSG is assembled at the location where it will be used). Each sensor has sensor leads extending therefrom. Manual installation of the sensors and routing the sensor leads through (and out of) the HRSG typically requires the placement of scaffolding or other elevated equipment in close proximity to the heat exchange tubes, which can be, for example, 10 to 25 meters in height. Sensors are only installed on the outermost rows of heat exchangers because, once assembled, it is virtually impossible to reach the interior of multiple rows of heat exchange tubes. Consequently, measurements of the operating characteristics of the heat exchange process within the inner rows of heat exchange tubes are unavailable, limiting understanding of how to best control the operation of the CCPP or heat exchanger, which affects the heat exchange process and overall efficiency of the system. Summary of the Invention

[0004] One aspect of the present disclosure provides a heat exchanger comprising: a plurality of groups of heat exchange tubes positioned adjacent to one another, each group of heat exchange tubes being fluidly coupled to at least one end of a header; a sensor grid positioned between the plurality of groups of heat exchange tubes, the sensor grid comprising a plurality of sensors, each sensor comprising a sensor lead extending therefrom; and a tube restrictor for positioning at least one of the plurality of groups of heat exchange tubes relative to a housing, the tube restrictor comprising a tube opening and a sensor lead opening for each of the heat exchange tubes of the corresponding group of heat exchange tubes, wherein at least one sensor lead of the sensor grid extends through the sensor lead opening.

[0005] Another aspect of the present disclosure provides a combined cycle power plant (CCPP) comprising: a gas turbine system; a steam turbine system; and a heat recovery steam generator (HRSG) coupled to the gas turbine system to use exhaust gas from the gas turbine system to generate steam for the steam turbine system, wherein the HRSG comprises: a casing configured to direct the exhaust gas therethrough; a plurality of groups of heat exchange tubes positioned adjacent to one another in the casing, each group of heat exchange tubes fluidly coupled to at least one end of a header; a sensor grid positioned between the plurality of groups of heat exchange tubes, the sensor grid comprising a plurality of sensors, each sensor including a sensor lead extending therefrom; a pipe restrictor for positioning at least one of the plurality of groups of heat exchange tubes relative to the casing, the pipe restrictor comprising a pipe opening and a sensor lead opening for each of the heat exchange tubes of the corresponding group of heat exchange tubes, wherein at least one sensor lead of the sensor grid extends through the sensor lead opening.

[0006] Another aspect of the present disclosure provides a tube restrictor for a group of heat exchange tubes of a heat exchanger, the tube restrictor comprising: a body; a plurality of tube openings defined in the body, each tube opening being configured to receive one heat exchange tube of the group of heat exchange tubes therethrough; and a sensor lead opening defined in the body and configured to receive a sensor lead therethrough, wherein each tube opening has a larger size than the sensor lead opening.

[0007] The exemplary aspects of the present disclosure are designed to solve the problems described herein and / or other problems not discussed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the disclosure taken in conjunction with the accompanying drawings which depict various embodiments of the disclosure, in which:

[0009] Figure 1 A schematic diagram illustrating an exemplary application of a heat exchanger in the form of a combined cycle power plant according to an embodiment of the present disclosure;

[0010] Figure 2 A partial transparent perspective view of a heat exchanger having vertical heat exchange tubes according to one embodiment of the present disclosure is shown;

[0011] Figure 3 shows a partial transparent perspective view of a heat exchanger having horizontal heat exchange tubes according to one embodiment of the present disclosure;

[0012] Figure 4 shows a perspective view of an exemplary prior art heat exchange tube;

[0013] Figure 5 shows a perspective view of multiple sets of heat exchange tubes and a sensor grid for a heat exchanger according to an embodiment of the present disclosure;

[0014] Figure 6 shows a side view of a pair of heat exchange tube banks and a sensor grid for a heat exchanger according to an embodiment of the present disclosure;

[0015] Figure 7 shows an enlarged side view of a set of heat exchange tubes and a sensor grid for a heat exchanger according to an embodiment of the present disclosure;

[0016] Figure 8 shows a perspective view of a tubular restraint according to an embodiment of the present disclosure;

[0017] Figure 9 a perspective view showing a conduit passing through a baffle at the end of a header of a heat exchanger according to an embodiment of the present disclosure; and

[0018] Figure 10 Shown are end views of the ends of headers having conduits passing through baffles according to embodiments of the present disclosure.

[0019] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. In the drawings, similar numbers represent similar elements between the drawings. DETAILED DESCRIPTION

[0020] First, in order to clearly describe the current technology, it is necessary to select certain terms when referencing and describing an exemplary application in the form of a combined cycle power plant and components thereof. To the extent possible, common industry terms will be used and adopted in a manner consistent with the accepted meaning of the terms. Unless otherwise indicated, such terms should be given a broad interpretation consistent with the context of this application and the scope of the appended claims. One of ordinary skill in the art will understand that several different or overlapping terms may often be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referenced in another context as consisting of multiple components. Alternatively, an object that may be described herein as comprising multiple components may be referred to elsewhere as a single part.

[0021] In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the beginning of this section. Unless otherwise indicated, these terms and their definitions are as follows. As used herein, "downstream" and "upstream" are terms that indicate the direction relative to the flow of a fluid, such as the working fluid through a turbine engine, or, for example, the flow of hot air through a heat exchanger. The term "downstream" corresponds to the direction of the flow of the fluid, and the term "upstream" refers to the direction opposite to the flow (i.e., the direction from which the flow originates). In the absence of any additional particularity, the terms "front" and "rear" refer to directions, where "front" refers to the front end or compressor end of the engine, and "rear" refers to the rear end or turbine end of the engine.

[0022] It is often necessary to describe parts that are in different radial positions relative to a central axis. The term "radial" refers to movement or position perpendicular to the axis. In cases such as this, if a first component resides closer to the axis than a second component, then this document will refer to the first component as being "radially inward" or "inboard" of the second component. On the other hand, if the first component resides farther away from the axis than the second component, then this document may refer to the first component as being "radially outward" or "outboard" of the second component. The term "axial" refers to movement or position parallel to the axis. Finally, the term "circumferential" refers to movement or position around the axis. It should be understood that such terms may apply relative to the central axis of the turbine.

[0023] In addition, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0024] The terms used herein are only used to describe the purpose of specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in the specification, the terms "comprise" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, or the parts or features described subsequently may or may not exist, and the description includes instances in which the event occurs or the parts exist and instances in which the event does not occur or the parts do not exist.

[0025] When an element or layer is referred to as being "on," "engaged to," "connected to," or "coupled to" another element or layer, it may be directly on, engaged to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0026] As indicated above, the present disclosure provides a heat exchanger comprising a sensor grid having sensor leads extending through a tube restrictor for heat exchange tubes in the heat exchanger. The heat exchanger comprises a plurality of groups (e.g., rows) of heat exchange tubes positioned adjacent to one another. The tube restrictor comprises a body having a plurality of tube openings defined therein, wherein each tube opening receives one heat exchange tube from a group of heat exchange tubes therethrough. The body further comprises sensor lead openings defined therein for receiving sensor leads therethrough. Each tube opening is larger than the sensor lead opening.

[0027] The sensor grid comprises multiple sensors that are installed during manufacturing rather than in the field. This allows sensor leads for the sensor grid to be installed through pipe restraints rather than over them. Unlike heat exchanger tubes, which are installed in the field, each group of heat exchanger tubes is accessible during manufacturing. Therefore, the sensor grid can be installed not only to the outermost group of heat exchanger tubes but also to any inner group of heat exchanger tubes in the heat exchanger. With this arrangement of the sensor grid, more data about the operation of the heat exchanger can be collected and used to provide more efficient operation of the heat exchanger or the power plant using the heat exchanger.

[0028] Go to Figure 1 , a heat exchanger according to an embodiment of the present disclosure will be described with respect to an exemplary application in the form of a combined cycle power plant (CCPP) 100 . Figure 1 A schematic diagram of a CCPP 100 is shown. It should be emphasized that the teachings of the present disclosure are applicable to any heat exchanger. CCPP 100 may include a gas turbine (GT) system 102 operably connected to a generator 104, and a steam turbine (ST) system 110 operably coupled to another generator 112. Generator 104 and GT system 102 may be mechanically coupled via a shaft 106 that may transfer energy between a drive shaft (not shown) of GT system 102 and generator 104.

[0029] It should be understood that the generators 104, 112 and shaft 106 can be of any size or type known in the art and can vary depending on their application or the system to which they are connected. The common numbering of the generators and shafts is for clarity and does not necessarily indicate that the generators or shafts are identical. In the exemplary application, CCPP 100 is a single-shaft system with two generators, but those skilled in the art will readily appreciate that the teachings of the present disclosure are applicable to any type of combined cycle power generation system.

[0030] exist Figure 1 Also shown is a heat exchanger 108 operatively connected to the GT system 102 and the ST system 110. As will be described in greater detail herein, the heat exchanger 108 may include a heat recovery steam generator (HRSG) (as labeled in the figure) that includes a sensor grid positioned according to an embodiment of the present disclosure. The heat exchanger 108 may be fluidly connected to both the GT system 102 and the ST system 110 via conventional conduits (numbering omitted).

[0031] The GT system 102 may include a compressor 120 and a combustor 124. The combustor 124 includes a combustion region 126 and a fuel nozzle assembly 128. The GT system 102 also includes a gas turbine 130 coupled to the common compressor / turbine shaft 106. In one non-limiting example, the GT system 102 may be a 7HA.03 engine, commercially available from General Electric Company, Greenville, SC. The present disclosure is not limited to any particular GT system and may be implemented with other engines, including, for example, General Electric's HA, F, B, LM, GT, TM, and E-class engines, as well as engines from other companies.

[0032] In operation, air enters the inlet of compressor 120, is compressed, and then discharged to combustor 124 where a gaseous or liquid fuel (such as natural gas or oil) is burned to provide high-energy combustion gases that drive gas turbine 130. In gas turbine 130, the energy of the hot gases is converted to work, some of which is used to drive compressor 120 by rotating shaft 106, with the remainder being used to drive a load such as generator 104 via shaft 106 to produce useful work of electricity.

[0033] Figure 1 The CCPP 100 is also shown in its simplest form, where the energy in the exhaust gas leaving the gas turbine 130 is converted into additional useful work. The exhaust gas enters a heat exchanger 108 in the form of a HRSG, where water is converted into steam in the manner of a boiler. The heat exchanger 108 can also use the energy to generate hot feed water.

[0034] The ST system 110 may include one or more steam turbines. For example, the ST system 110 may include a high pressure (HP) turbine 132, an intermediate pressure (IP) turbine 134, and a low pressure (LP) turbine 136, each of which is coupled to the shaft 106. Each steam turbine 132, 134, 136 includes a plurality of rotating blades (not shown) mechanically coupled to the shaft 106. In operation, steam from the heat exchanger 108 and possibly other sources enters the inlet of the HP turbine 132, the IP turbine 134, and / or the LP turbine 136 and is directed to exert force on its blades, thereby rotating the shaft 106. As will be appreciated, steam from the upstream turbine may be later employed in the downstream turbine. Thus, the steam generated by the heat exchanger 108 drives at least a portion of the ST system 110, wherein additional work is extracted to drive the shaft 106 and an additional load such as a second generator 112, which in turn generates additional electricity. In some configurations, the turbines 130, 132, 134, 136 drive a common generator.

[0035] Figure 1 Also shown is a CCPP control system 138 operatively coupled to the GT system 102, the heat exchanger (i.e., HRSG) 108, and the ST system 110. The control system 138 may include any now known or later developed computerized controller for providing automated control of the CCPP 100. As will be described, the control system 138 may receive data from a plurality of sensors of a sensor grid within the heat exchanger 108 and may use this data to control the heat exchanger 108 and / or other components of the CCPP 100.

[0036] Figure 2 and Figure 3 A partially transparent perspective view of an embodiment of a heat exchanger 108 is shown. The heat exchanger 108 is shown as a HRSG configured to be coupled to the GT system 102 ( Figure 1 ) and delivers the steam to, for example, the ST system 110 ( Figure 1 ) and / or deliver heated water to other components of CCPP 100 ( Figure 1 As shown, the heat exchanger 108 includes an insulated housing 140 (hereinafter referred to as "housing 140") configured to contain a fluid 142. The housing 140 may be housed in a heat exchanger housing 148. The housing 140 may include any now known or later developed insulated conduit configured to contain the fluid 142, such as having a carbon steel or stainless steel inner liner, an insulation layer, and an outer carbon steel layer. The heat exchanger housing 148 may include any now known or later developed structural protection, such as a building or other physical protection.

[0037] The fluid 142 may be any form of gas that has a thermal difference with the fluid 144 (shown only by arrows) flowing through the plurality of heat exchange tubes 146 of the heat exchanger 108. Heat is exchanged between the fluid 142 and the fluid 144. The fluid 142 may be a gas from the GT system 102 ( Figure 1 ), while fluid 144 may be a liquid (e.g., water) and / or a gas (e.g., steam). Fluid 142 passes over and around the exterior surfaces of a plurality of heat exchange tubes 146 and exits housing 140 via an exhaust system 150 (e.g., a chimney and / or a scrubber, etc.), while fluid 144 passes through the interiors of the plurality of heat exchange tubes 146.

[0038] Figure 2 and Figure 3 The difference is that in Figure 2 In the embodiment, the tube 146 extends in a vertical direction or arrangement and the fluid 142 passes therearound in a generally horizontal direction, while in the embodiment Figure 3In the embodiment of the present invention, the tube 146 extends in a horizontal direction or arrangement and the fluid 142 passes around it in a generally vertical direction. As used herein, "generally" when applied to the flow direction of the fluid 142 means that the fluid generally travels in the specified direction, but has some minor or temporary deviations as it passes through or around the tube 146 that may impede its path. Although relative to Figure 2 The teachings of the present disclosure are described in detail with reference to the embodiments of the present disclosure, but it should be readily understood that the teachings are also applicable to Figure 3 implementation plan.

[0039] The tube 146 may have any now known or later developed form of heat exchange tubing and may be made of any material that can provide the desired heat transfer characteristics, flexibility, and the ability to withstand the environment to which it is exposed. The dimensions of the tube 146 may vary depending on the application, for example, in some applications the outer diameter may vary between 1.25 inches and 2.0 inches.

[0040] Figure 4 A perspective view of an exemplary prior art heat exchange tube in the form of a finned tube is shown. As shown, in one non-limiting example, tube 146 may include a plurality of disks 152 arranged around a central tube 154 aligned in a longitudinal direction 156. Each disk 152 may be substantially planar and may be stacked so that it is longitudinally positioned above and / or below at least one adjacent disk 152. Central tube 154 may include any tubular member, now known or later developed, configured to allow fluid 144 to pass therethrough, such as by pumping or other force. Each disk 152 may include a plurality of fin segments 158 extending radially outward from a disk center portion 160, such that fin segments 158 extend outward from central tube 154. Disk center portion 160 extends circumferentially around the periphery of central tube 154. Each of fin segments 158 is separated from an adjacent fin segment 158 by serrations 163. Fin segments 158 of adjacent disks may be circumferentially and / or longitudinally aligned or circumferentially and / or longitudinally offset. The fin segments 158 may be arranged longitudinally above and / or below the fin segments 158 in a spiral configuration, an alternating pattern, and / or a random configuration relative to them.

[0041] The one or more disks 152 may be constructed at least in part from carbon steel, alloy steel, stainless steel, aluminum, beryllium, copper, gold, magnesium, iridium, molybdenum, rhodium, silver, tungsten, and / or other suitable materials and alloys thereof. The center tube 154 may be constructed at least in part from carbon steel, alloy steel, stainless steel, ferritic stainless steel, austenitic stainless steel, and / or other materials that are sufficiently thermally conductive, stress-resistant, and temperature-resistant. While one example of the heat exchange tubes 146 has been described, it should be understood that the heat exchanger tubes may take a variety of alternative forms.

[0042] Figure 5An enlarged perspective view of an upper portion 170 (sometimes referred to as a gallery) of the heat exchanger 108 is shown. As shown, the upper portion 170 includes a plurality of manifolds or headers that distribute fluid 144 to the heat exchange tubes 146. For example, a plurality of manifolds 172 can direct the fluid 144 to or from a plurality of upper headers 174. The heat exchanger 108 includes a plurality of groups 176 of heat exchange tubes 146 positioned adjacent to each other. Each group 176 of heat exchange tubes 146 is fluidly coupled to an (upper) header 174 at one end thereof. That is, each upper header 174 is in fluid communication with a group 176 of heat exchange tubes 146 to direct the fluid 144 from the manifolds 172 to the group of heat exchange tubes 146.

[0043] exist Figure 5 In the example shown, the plurality of groups 176 of heat exchange tubes 146 are also in fluid communication with corresponding lower headers 178, which allows the direction of the fluid to change as it passes through different tubes 146 within a given group 176 of tubes 146. In the example shown, the group 176 of heat exchange tubes 146 may be as shown. Figure 2 178, and thus the set of heat exchange tubes together with the connected headers 174, 178 are referred to as a "harp section" because of their resemblance to a musical instrument harp. In an alternative embodiment, the tubes 146 may have U-shaped ends without the lower header 178, see e.g. Figure 3 and Figure 7 (right side).

[0044] In the exemplary embodiment, the plurality of groups 176 of heat exchange tubes 146 share a common manifold (source) 172 for the fluid 144 and are arranged in rows, with each row having its own upper header 174. It should be emphasized that the plurality of groups 176 of heat exchange tubes 146 do not necessarily need to be arranged in rows; for example, they can be staggered, randomly arranged, temporarily offset, etc. Each group 176 can include any number of heat exchange tubes 146, for example, 38-50 tubes arranged throughout a row. For example, each header 174 can be 2 meters to 6 meters long.

[0045] The plurality of groups 176 of heat exchange tubes 146 include a first outermost group 176A of heat exchange tubes 146, a second outermost group 176B of heat exchange tubes 146 opposite the first outermost group 176A of heat exchange tubes 146, and at least one inner group 176C of heat exchange tubes 146 between the first outermost group 176A of heat exchange tubes and the second outermost group 176B of heat exchange tubes. Any number of groups 176 of heat exchange tubes 146 may be used. For example, 10-30 groups 176 of heat exchange tubes 146 may be provided in series with the fluid 142. Figure 5 In the non-limiting example shown, fourteen (14) groups 176 of heat exchange tubes are shown with twelve (12) inner groups 176C.

[0046] Figure 6shows a side view of two sets 176 of heat exchange tubes 146 (side-by-side) according to an embodiment of the present disclosure, Figure 7 shows an enlarged partial side view of a set 176 of heat exchange tubes 146 according to an embodiment of the present disclosure, and Figure 8 An enlarged partial perspective view of a pipe restraint 190 according to an embodiment of the present disclosure is shown. The group shown may be Figure 5 Any group in , i.e. the outermost group or the inner group. Figure 6 and Figure 7 As shown, the heat exchanger 108 includes a sensor grid 180 positioned between the plurality of groups of heat exchange tubes 146. The sensor grid 180 includes a plurality of sensors 182. "Sensor grid" 180 is used herein in a general manner to indicate a desired distributed layout or arrangement of the sensors 182 and is not necessarily used to describe the sensors 182 being arranged in any particular spacing framework.

[0047] Each sensor 182 may be any now known or later developed sensor, such as, but not limited to, a thermocouple, a resistance temperature detector (RTD), or other type of temperature sensor; a pressure or flow rate sensor, such as a pitot tube; a strain gauge; a gas sampling tube, etc. The sensors 182 within the sensor grid 180 need not all be of the same type. For example, the sensors 182 may measure fluid temperature, tube or fin metal temperature, gas static pressure, gas velocity, tube or header strain, exhaust gas composition (such as oxygen, NOx, CO, CO2, hydrocarbons), particulates, ammonia leakage, etc. Thus, the sensors 182 allow data to be collected to determine, for example, the thermal or pressure drop performance of a heat exchanger 108 section, gas temperature or exhaust gas composition distribution for evaluating combustors and emission control devices, gas velocity distribution, tube or header thermal strain, etc.

[0048] Each sensor 182 may include a sensor lead 184 extending therefrom. The sensors 182 may also share a sensor lead 184. The sensor lead 184 may include a sensor that can communicate with one or more corresponding sensors 182 and the control system 138 ( Figure 1 ) any form of linear structure for communication, such as electrical wires with any form of shielding, pneumatic tubing for pitot tube type sensors, etc. The sensor 182 and sensor leads 184 are constructed of suitable materials to withstand the operating environment of the heat exchanger 108.

[0049] According to embodiments of the present disclosure, the sensor grid 180 and its corresponding sensors 182 may be coupled to one or more banks 176 of heat exchange tubes 146 during manufacturing. That is, the sensor grid 180 is installed during the coupling of the heat exchange tubes 146 to the header 174 to form the "harp" and prior to the final installation of multiple other banks 176 of heat exchange tubes 146 in parallel at the power plant site. Thus, and in contrast to conventional heat exchanger sensor systems, the sensor grid 180 of the heat exchanger 108, once assembled on site, may include coupling to at least one internal bank 176C ( Figure 5 ) at least one sensor 182 of at least one of the heat exchange tubes 146. In this way, operational data may be measured at any location within the heat exchanger 108 and from any heat exchange tube 146. Any number of sensors 182 may be used, and the sensors 182 may be arranged in any manner. For example, in Figure 6 In FIG. 1 , five thermocouples may be vertically spaced apart at horizontal planes TC1 - TC5 in any set 176 of heat exchange tubes 146. Sensor leads 184 may extend to any location within heat exchanger 108.

[0050] The heat exchanger 108 also includes a tube restraint 190 for positioning at least one of the plurality of groups 176 of heat exchange tubes 146 relative to the housing 140. Any number of tube restraints 190 may be used along any given group 176 of heat exchange tubes 146 within the heat exchanger 108. For example, Figure 5 and Figure 7 The partial view shows two pipe restraints 190, and Figure 6 Eight (8) tube restraints are shown. The tube restraints 190 may be spaced apart in any manner necessary to maintain the position of the heat exchange tubes 146 (eg, vertically as shown).

[0051] Figure 8 1 shows a partial perspective view of a tube restrictor 190 according to an embodiment of the present disclosure. Each tube restrictor 190 includes a body 192 and a plurality of tube openings 194 defined in the body. Each tube opening 194 is configured to receive one heat exchange tube 146 (176) of a set 176 of heat exchange tubes 146 therethrough. Figure 8 (Only some of the groups are shown). In the example shown, the tube openings 194 are in the form of holes 196 in the body 192. In other embodiments, the tube openings 194 may be open seats, thereby forming a scalloped strip. In any case, the tube restraints 190 position the heat exchange tubes 146 and inhibit them from moving in an undesirable manner or allow controlled movement, for example, by thermal expansion or a controlled actuator (not shown).

[0052] In contrast to conventional tube restrictors, tube restrictor 190 may also include sensor lead openings 200 defined in body 192. Sensor lead openings 200 are configured to receive one or more sensor leads 184 therethrough. Each tube opening 194 has a larger size than sensor lead openings 200, for example, having a larger diameter when circular. Conventional tube restrictors do not require and do not provide sensor lead openings 200 because they are unnecessary because sensor leads 184 are coupled to the exterior of the tubes and the tube restrictor is only on the outermost group of heat exchange tubes.

[0053] Because the multiple groups 176 of heat exchange tubes 146 are manufactured with the sensor grid 180 coupled thereto, the sensors 182 of the sensor grid 180 can be positioned at any desired location on the group 176 of heat exchange tubes 146, and the corresponding sensor leads 184 can be easily positioned through the sensor lead openings 200. The sensor lead openings 200 allow for common routing of the sensor leads 184 and protect the leads during, for example, on-site transportation and assembly of the heat exchanger 108. Each sensor lead opening 200 can be sized to accommodate any number of sensor leads 184 positioned therethrough. For example, a tubing restrictor 190 closer to a location through which sensor leads 184 will exit the housing 140 can have a larger sensor lead opening 200 to accommodate the sensor leads of any number of downstream sensors 182.

[0054] The sensors 182 and sensor leads 184 may be coupled to the plurality 176 of heat exchange tubes 146 by any now known or later developed means, such as, but not limited to, cable ties and / or tube restraints 190 attached to the tubes 146. The sensors 182 may be operatively positioned as desired to measure a desired operating parameter, such as temperature. Figure 6 As shown in the enlarged portion of , the sensor lead 184 may include an expansion bend 202 therein to accommodate thermal expansion / contraction in the heat exchanger 108 .

[0055] Figure 9 An enlarged perspective view of the ends of a pair of adjacent headers 174A, 174B is shown, and Figure 10 An end view of the pair of adjacent headers 174A, 174B is shown. Figure 5 and Figure 9 An enlarged perspective view of adjacent headers 174 ( Figure 9 The ends of 174A, 174B in FIG. 1 do not extend to the same length (they have non-coplanar ends). Figure 5 As shown, the ends of the headers 174 may be staggered in length. More specifically, as shown Figure 9As best shown, the ends 210 of the headers 174A of the first set 176D of heat exchange tubes 146 do not extend longitudinally to the same extent as the ends 212 of the adjacent headers 174B of the second set 176E of heat exchange tubes 146. Figure 9 and Figure 10 Shown (not shown for clarity) Figure 5 , the shorter header 174A includes a baffle 220 extending from its end, for example, to prevent the fluid 142 from migrating upward through the gap or to direct the fluid 142 in a desired manner through the heat exchanger 108. The baffle 220 may extend to the same longitudinal extent as the adjacent header 174B. That is, the end 212 of the header 174B of the second group 176E of heat exchange tubes 146 adjacent to the header 174A of the first group 176D of heat exchange tubes 146 may extend from the end 210 of the header 174A of the first group 176D of heat exchange tubes 146 to the same length as the baffle 220.

[0056] The sensor leads 184 may need to be extended upward between any two adjacent groups 176D, 176E (inner or outermost groups) of heat exchange tubes 146. To guide the sensor leads 184 through the baffle 220, the heat exchanger 108 may also include a conduit 222 extending through the baffle 220. The conduit 222 may include a sensor grid 180 extending therethrough. Figure 5 ) of the plurality of sensor leads 184. Thus, the sensor leads 184 can be routed through the baffle 220. The conduit 222 can take a variety of forms, but in the illustrated example, the conduit includes a first length 230 extending along the end 210 of the header 174A of the first group 176D of heat exchange tubes 146 and a second length 232 extending along the length of the header 174A of the first group 176D of heat exchange tubes 146. If desired, the first length 230 can be fixedly coupled to the end 210 of the header 174A, for example, by a gusset or other connector. Although not required in all cases, the first length 230 can be at a substantially perpendicular angle to the second length 232. The conduit 222 can have any cross-sectional shape and, for example, if the sensor leads 184 are not very flexible, the conduit can be formed in components that are later fastened together, such as by welding, to allow the sensor leads 184 to be routed therethrough. For example, the conduit 222 may include a pair of longitudinally extending portions 234, 236 coupled together, such as halves coupled along a weld 238. The conduit 222 may be made of any material capable of withstanding the environment of the heat exchanger 108.

[0057] Sensor leads 184 may be routed along headers 174A, 174B and ultimately exit through housing 140. Figure 5, the sensor leads 184 are shown as exiting through the top plate 224 of the housing 140; however, the sensor leads may extend through any portion of the housing 140. The sensor leads 184 may be coupled to the control system 138 ( Figure 1 ) for operational control of any number of components of CCPP100.

[0058] As described herein, embodiments of the present disclosure also include a pipe restraint 190 and a CCPP 100. Although a particular type of power plant and a particular type of CCPP 100 have been described herein, it should be emphasized that the teachings of the present disclosure are applicable to any type of heat exchanger.

[0059] As described herein, embodiments of the present disclosure allow the sensor grid 180 to be installed adjacent to any group 176 of heat exchange tubes 146. Thus, the sensor grid 180 can provide data about any portion of the heat exchanger 108, even for the inner group 176C of heat exchange tubes 146 ( Figure 5 Installing the sensor grid 180 during multi-unit fabrication is easier and faster than on-site installation and avoids installing the sensor grid 180 on the critical path of the on-site construction schedule. The sensor grid 180 also supports online performance monitoring, proactive control for CCPP 100 efficiency optimization, and heat exchanger 108 component life monitoring and optimization.

[0060] As used throughout the specification and claims, approximate language can be used to modify any quantitative expression that can be permitted to vary without resulting in a change in the basic function to which it is related. Therefore, a value modified by one or more terms (such as "about," "approximately," and "substantially") is not limited to the precise value specified. In at least some cases, approximate language can correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations can be combined and / or interchangeable. Unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. "About" applied to a particular value of a range applies to both end values and, unless otherwise dependent on the precision of the instrument for measuring the value, can indicate + / - 10% of that value.

[0061] The corresponding structures, materials, actions and equivalents of all means or step-plus-function elements in the following claims are intended to include any structure, material or action for performing the function in conjunction with other claimed elements for specific protection. The description of the present disclosure has been given for the purpose of illustration and description, but it is not intended to be exhaustive or to limit the disclosure to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and essence of the present disclosure. The embodiments have been selected and described in order to best explain the principles and practical applications of the present disclosure and to enable others skilled in the art to understand the various embodiments of the present disclosure with various modifications suitable for the intended specific use.

Claims

1. A heat exchanger comprising: a plurality of groups of heat exchange tubes positioned adjacent to one another, each group of heat exchange tubes fluidly coupled at ends thereof to a header; a sensor grid positioned between the plurality of groups of heat exchange tubes, the sensor grid comprising a plurality of sensors, each sensor including a sensor lead extending therefrom; and a tube restrictor for positioning at least one of the plurality of groups of heat exchange tubes relative to the housing, the tube restrictor comprising a tube opening and a sensor lead opening, the tube opening being for each of the heat exchange tubes of the corresponding group of heat exchange tubes, wherein at least one sensor lead of the sensor grid extends through the sensor lead opening, and The end of the header of the first set of heat exchange tubes includes a baffle extending therefrom, and the heat exchanger further includes a conduit extending through the baffle, the conduit including a plurality of sensor leads of the sensor grid extending therein.

2. The heat exchanger of claim 1 , wherein the plurality of groups of heat exchange tubes include a first outermost group of heat exchange tubes, a second outermost group of heat exchange tubes, and at least one inner group of heat exchange tubes between the first outermost group of heat exchange tubes and the second outermost group of heat exchange tubes, and wherein the sensor grid includes at least one sensor coupled to at least one heat exchange tube of the at least one inner group of heat exchange tubes. 3 . The heat exchanger according to claim 1 , wherein an end portion of the header of the second group of heat exchange tubes adjacent to the header of the first group of heat exchange tubes extends from the end portion of the header of the first group of heat exchange tubes to the same length as the baffle.

4. The heat exchanger of claim 1, wherein the conduit comprises a first length extending along the end of the header of the first set of heat exchange tubes and a second length extending along the length of the header of the first set of heat exchange tubes.

5. The heat exchanger of claim 4, wherein the first length is fixedly coupled to the end of the header. The heat exchanger of claim 4 , wherein the first length is at a perpendicular angle to the second length.

7. The heat exchanger of claim 1, wherein the conduit comprises a pair of longitudinally extending portions coupled together.

8. A combined cycle power plant comprising: gas turbine systems; steam turbine systems; and a heat recovery steam generator coupled to the gas turbine system to generate steam for the steam turbine system using exhaust gas from the gas turbine system, wherein the heat recovery steam generator comprises: a housing configured to direct the exhaust gas therethrough; a plurality of groups of heat exchange tubes positioned adjacent to one another in the shell, each group of heat exchange tubes fluidly coupled to a header at one end thereof; a sensor grid positioned between the plurality of groups of heat exchange tubes, the sensor grid comprising a plurality of sensors, each sensor including a sensor lead extending therefrom; a tube restrictor for positioning at least one of the plurality of heat exchange tube groups relative to the housing, the tube restrictor comprising a tube opening and a sensor lead opening, the tube opening being for the heat exchange tube of the corresponding group of heat exchange tubes; wherein at least one sensor lead of the sensor grid extends through the sensor lead opening, and The end of the header of the first set of heat exchange tubes includes a baffle extending therefrom, and the combined cycle power plant further includes a conduit extending through the baffle, the conduit including a plurality of sensor leads of the sensor grid extending therein.

9. The combined cycle power plant of claim 8, wherein the plurality of groups of heat exchange tubes include a first outermost group of heat exchange tubes, a second outermost group of heat exchange tubes, and at least one inner group of heat exchange tubes between the first outermost group of heat exchange tubes and the second outermost group of heat exchange tubes, and wherein the sensor grid includes at least one sensor coupled to at least one heat exchange tube of the at least one inner group of heat exchange tubes.

10. The combined cycle power plant according to claim 8, wherein an end of the header of a second group of heat exchange tubes adjacent to the header of the first group of heat exchange tubes extends from the end of the header of the first group of heat exchange tubes to the same length as the baffle.

11. The combined cycle power plant of claim 8, wherein the conduit comprises a first length extending along the end of the header of the first set of heat exchange tubes and a second length extending along the length of the header of the first set of heat exchange tubes.

12. The combined cycle power plant of claim 11, wherein the first length is fixedly coupled to the end of the header.

13. The combined cycle power plant of claim 11, wherein the first length is at a perpendicular angle to the second length.

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