Economizers for waste heat recovery systems

Abstract

An economizer includes an outer housing including a cover and a shell having a shellside inlet, a shellside outlet, and a plurality of slots formed in an interior of the outer housing, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell, an inlet fluid conduit, a discharge fluid conduit, and a plurality of tube cartridges individually and separately receivable in the plurality of slots formed in the interior of the outer housing, wherein at least some of the plurality of tube cartridges includes a tube chassis releasably connectable to the outer housing to lock the tube cartridge to the outer housing, and a heat transfer tube fluidically connectable to the inlet fluid conduit and the discharge fluid conduit when the tube cartridge is received in the interior of the outer housing.

Description

3604-00502ECONOMIZERS FOR WASTE HEAT RECOVERY SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a non-provisional application claiming priority to U.S. provisional patent application No. 63 / 754,784 filed February 6, 2025, and entitled “Economizers for Waste Heat Recovery Systems,” which is hereby incorporated herein by reference in its entirety for all purposes.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] Not applicable.BACKGROUND

[0003] The disclosure relates generally to economizers for waste heat recovery systems. Particularly, as used herein, the term “economizer” refers to a device or component of a waste heat recovery system that recovers waste heat from a heat source of the waste heat recovery system. For example, the waste heat may include hot exhaust gasses generated by an internal combustion engine (ICE) and the like whereby the economizer may recover at least some of the heat contained in the exhaust gasses before they are exhausted to the ambient environment. For instance, the economizer may transfer at least some of the heat from the exhaust gasses (or other waste heat) to a separate fluid stream which may require heating as part of the operation of the waste heat recovery system comprising the economizer. For example, the economizer may transfer waste heat to water prior to the boiling of the water (e.g., for feeding to a steam turbine) to thereby reduce the amount of energy that must be inputted to the water by the boiler and increase the overall thermal efficiency of the waste heat recovery system.BRIEF SUMMARY OF THE DISCLOSURE

[0004] An embodiment of an economizer for a waste heat recovery system comprise an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and a plurality of slots formed in an interior of the outer housing, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell, an inlet fluid conduit defining a tubeside inlet of the3604-00502economizer, a discharge fluid conduit defining a tubeside discharge of the economizer, and a plurality of tube cartridges individually and separately receivable in the plurality of slots formed in the interior of the outer housing, wherein at least some of the plurality of tube cartridges comprises: a tube chassis releasably connectable to the outer housing to lock the tube cartridge to the outer housing, and a heat transfer tube fluidically connectable to the inlet fluid conduit and the discharge fluid conduit when the tube cartridge is received in the interior of the outer housing. In some embodiments, the plurality of slots are defined by a plurality of elongate rails positioned in the interior of the outer housing that physically divide the plurality of slots from one another. In certain embodiments, the economizer comprises a plurality of fasteners configured to releasably couple the tube chassis of the plurality of tube cartridges to the outer housing. In certain embodiments, the heat transfer tube of at least some of the plurality of tube cartridges comprises a plurality of parallel extending linear tubes and a plurality of elbows interconnecting the plurality of linear tubes. In some embodiments, the economizer comprises a plurality of releasable connectors configured to releasably couple opposing ends of the heat transfer tube of at least some of the plurality of tube cartridges to the inlet fluid conduit and the discharge fluid conduit. In some embodiments, the plurality of releasable connectors each comprises a threaded connector. In certain embodiments, the economizer comprises a plurality of valves fluidically connectable in parallel between the plurality of tube cartridges and both the inlet fluid conduit and the discharge fluid conduit for individually fluidically isolating selected tube cartridges of the plurality of tube cartridges from both the inlet fluid conduit and the discharge fluid conduit. In certain embodiments, at least one of the tube cartridges comprises a tube and a plurality of fluid nozzles in fluid communication with the tube of the tube cartridge and spaced longitudinally along the tube for emitting a plurality of fluid jets extending along jet axes directed orthogonally against the heat transfer tubes of other tube cartridges of the plurality of tube cartridges.

[0005] A embodiment of an economizer for a waste heat recovery system comprise an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and defining an interior extending between the inlet and the outlet, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell, an inlet fluid conduit defining a tubeside inlet of the economizer, a discharge fluid conduit defining a tubeside discharge of the economizer,3604-00502a plurality of heat transfer tubes connected fluidically in parallel between the inlet fluid conduit and the discharge fluid conduit, wherein the plurality of heat transfer tubes slidably extend through a plurality of tube openings formed in the cover, and a plurality of seal assemblies sealing interfaces formed between the plurality of heat transfer tubes and the plurality of tube openings of the cover through the plurality of heat transfer tubes extend. In some embodiments, each of the plurality of seal assemblies are coupled to the cover with the plurality of heat transfer tubes extending slidably therethrough. In some embodiments, each of the plurality of seal assemblies comprises an annular collar coupled to the cover, an annular seal received within the collar, and an annular connector releasably connectable to the collar, and the connector is insertable into the collar to longitudinally compress the seal assembly and increase a sealing force applied by the annular seal to both the collar and a heat transfer tube of the plurality of heat transfer tube extending through the seal assembly. In certain embodiments, the connector of each of the plurality of seal assemblies is threadable into the collar of the seal assembly. In certain embodiments, the collar of each of the plurality of seal assemblies comprises a threaded inner surface, the connector comprises a threaded outer surface threadably engaged with the threaded inner surface of the collar. In some embodiments, each of the plurality of heat transfer tubes comprises a plurality of parallel extending linear tubes and a plurality of elbows interconnecting the plurality of linear tubes. In some embodiments, the plurality of heat transfer tubes are permitted to slide through the plurality of tube openings of the cover in response to disconnecting the plurality of heat transfer tubes from the inlet fluid conduit and the discharge fluid conduit. In certain embodiments, the economizer comprises a plurality of clamping assemblies for releasably connecting the shell to the cover, wherein each of the plurality of clamping assemblies comprises a first clamping member defining a first clamping surface, a second clamping member defining a second clamping surface, and a fastener for adjusting a width of a clamping opening formed between the first clamping surface and the second clamping surface. In some embodiments, the annular seal of each of the plurality of seal assemblies comprises at least one of a packing gland or an O-ring.

[0006] An embodiment of a method for redressing an economizer of a waste heat recovery system comprises (a) fluidically disconnecting a pair of ends of a heat transfer tube of a selected tube cartridge of a plurality of tube cartridges of the economizer from an inlet fluid conduit and a discharge fluid conduit of the economizer,3604-00502(b) individually extracting the selected tube cartridge from an interior of an outer housing of the economizer, (c) individually inserting a replacement tube cartridge into the interior of the outer housing of the economizer, and (d) fluidically connecting a pair of ends of a heat transfer tube of the replacement tube cartridge to the inlet fluid conduit and the discharge fluid conduit. In certain embodiments, (a) comprises disconnecting releasable connectors from the pair of ends of the heat transfer tube of the selected tube cartridge. In certain embodiments, the releasable connectors comprise threaded connectors. In some embodiments, (b) comprises sliding the selected tube cartridge from a corresponding slot formed in the interior of the outer housing. In some embodiments, the slot is formed by a plurality of elongate dividers positioned in the interior of the outer housing. In certain embodiments, (b) comprises sliding the pair of ends of the heat transfer tube through a pair of seal assemblies connected to the outer housing.

[0007] An embodiment of a method for redressing an economizer of a waste heat recovery system comprises (a) disconnecting a pair of ends of the heat transfer tube to separate the heat transfer tube from an inlet fluid conduit and a discharge fluid conduit of the economizer, (b) extracting a heat transfer tube of the economizer from an interior of an outer housing of the economizer, and (c) sliding a pair of ends of the heat transfer tube through a pair of seal assemblies of the economizer and a pair of tube openings formed in a cover that forms part of the outer housing to release the heat transfer tube from the outer housing. In certain embodiments, (b) comprises cutting the pair of ends of the heat transfer tube. In some embodiments, (b) comprises disconnecting the heat transfer tube from the tube bundle, and the method further comprises (d) sealing each of the pair of ends and the pair of seal assemblies, and (e) inserting a tube bundle comprising the heat transfer tube following (d) into the interior of the outer housing of the economizer. In some embodiments, (e) comprises vertically lowering the tube bundle into the interior of the outer housing. In certain embodiments, the method comprises (f) reconnecting the heat transfer tube to the tube bundle following (c) but prior to (e). In certain embodiments, (d) comprises welding an endcap onto each of the pair of ends. In some embodiments, (d) comprises threadably inserting an enclosed plug into each of the pair of seal assemblies.3604-00502BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a detailed description of various exemplary embodiments, reference will now be made to the accompanying drawings in which:

[0009] FIG. 1 is a block diagram of an embodiment of a waste heat recovery system in accordance with the principles described herein;

[0010] FIGS. 2 and 3 are perspective views of an embodiment of an economizer in accordance with the principles described herein;

[0011] FIG. 4 is a side cross-sectional view of the economizer of FIGS. 2 and 3;

[0012] FIGS. 5 and 6 are perspective views of an embodiment of a tube bundle of the economizer of FIGS. 2 and 3 in accordance with the principles disclosed herein;

[0013] FIG. 7 is a side view of the tube bundle of FIGS. 5 and 6;

[0014] FIG. 8 is an end view of the tube bundle of FIGS. 5 and 6;

[0015] FIGS. 9 and 10 are zoomed-in side cross-sectional views of the tube bundle of FIGS. 5 and 6.

[0016] FIG. 11 is a zoomed-in side view of an embodiment of a seal assembly of the economizer of FIGS. 2 and 3 in accordance with the principles described herein;

[0017] FIG. 12 is a zoomed-in side cross-sectional view of the seal assembly of FIG.11;

[0018] FIGS. 13-15 are perspective views of the economizer of FIGS. 2 and 3;

[0019] FIG. 16 is a perspective view of another embodiment of an economizer in accordance with the principles described herein;

[0020] FIG. 17 is a perspective view of an embodiment of a clamping assembly of the economizer of FIG. 16 in accordance with the principles disclosed herein;

[0021] FIG. 18 is a perspective view of another embodiment of an economizer in accordance with the principles described herein;

[0022] FIG. 19 is a perspective view of another embodiment of a clamping assembly of the economizer of FIG. 18 in accordance with the principles disclosed herein;

[0023] FIGS. 20 and 21 are perspective views of another embodiment of an economizer in accordance with the principles disclosed herein;

[0024] FIG. 22 is a side view of the economizer of FIGS. 20 and 21 ;

[0025] FIG. 23 is a zoomed-in, partial side view of the economizer of FIGS. 20 and 21;

[0026] FIG. 24 is a zoomed-in, partial perspective view of the economizer of FIGS.20 and 21;3604-00502

[0027] FIGS. 25 and 26 are perspective views of an embodiment of a tube cartridge of the economizer of FIGS. 20 and 21 in accordance with the principles disclosed herein;

[0028] FIG. 27 is a zoomed-in, partial perspective view of the economizer of FIGS.20 and 21;

[0029] FIG. 28 is a cross-sectional view along line 28-28 of FIG. 21 of the economizer of FIGS. 20 and 21 ;

[0030] FIGS. 29 is a perspective view of another embodiment of a tube cartridge of the economizer of FIGS. 20 and 21 in accordance with the principles disclosed herein;

[0031] FIG. 30 is a perspective view of an embodiment of a fluid nozzle of the tube cartridge of FIG. 29 in accordance with the principles disclosed herein;

[0032] FIG. 31 is a perspective, cross-sectional view of the fluid nozzle of FIG. 30;

[0033]

[0034] FIG. 20 is a flowchart of an embodiment of a method for redressing an economizer of a waste heat recovery systemin accordance with the principles described herein.DETAILED DESCRIPTION

[0035] The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

[0036] Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0037] Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be3604-00502interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.).

[0038] In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to... As used herein, the phrases “consist(s) of’ and “consisting of” are used to refer to exclusive components of a composition, meaning only those expressly recited components are included in the composition; whereas the phrases “consist(s) essentially of’ and “consisting essentially of” are used to refer to the primary components of a composition, meaning that only small or trace amounts of components other than the expressly recited components (e.g., impurities, byproducts, etc. ) may be included in the composition. For example, a composition consisting of X and Y refers to a composition that only includes X and Y, and thus, does not include any other components ; and a composition consisting essentially of X and Y refers to a composition that primarily comprises X and Y, but may include small or trace amounts of components other than X and Y. In embodiments described herein, any such small or trace amounts of components other than those expressly recited following the phrase “consist (s) essentially of” or “consisting essentially of” preferably represent less than 5.0 wt% of the composition, more preferably less than 4.0 wt% of the composition, even more preferably less than 3.0 wt% of the composition, and still more preferably less than 1.0 wt% of the composition. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc. Use of the term "optionally" with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim.

[0039] The term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be3604-00502through a direct engagement between the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a particular axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to a particular axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. As used herein, the terms “approximately,” “about,” “substantially,” and the like mean within 10% (i.e., plus or minus 10%) of the recited value. Thus, for example, a recited angle of “about 80 degrees” refers to an angle ranging from 72 degrees to 88 degrees.

[0040] As previously described, economizers are components of waste heat recovery systems generally configured to improve the thermal efficiency of the waste heat recovery system (or of a fluid system comprising the waste heat recovery system) by recovering waste heat from a heat source of the waste heat recovery system. This recovered waste heat may be transferred to a separate fluid such as a process fluid of the waste heat recovery system which would otherwise be heated using a dedicated power source such as a burner and the like.

[0041] Existing economizers generally include a tube bundle comprising a plurality of separate tubes each welded to a pair of tubesheets at opposing longitudinal ends of the plurality of tubes to prevent leakage at the connections formed with the tubesheets. Additionally, the tube bundle is typically welded at the connections formed between the individual tubes and a pair of tube manifolds fluidically connected to the opposing ends of the individual tubes. The tube bundle may be received in an outer shell or housing. For example, the tube manifolds may receive the flow of process fluid to be heated by the waste heat recovered by the economizer. Additionally, the outer housing of the existing economizer may comprise a fluid inlet configured to receive a flow of waste heat such as in the form of hot exhaust gasses, and a corresponding fluid outlet configured to expel the cooled exhaust gasses following heat transfer with the process fluid.

[0042] Generally, in the event of leaks, clogged tubes, and / or the rupture of one or more of the tubes of an existing economizer, requires shutting down the entire heat recovery system including the flow of waste heat to the economizer in order to address the issue. Additionally, given that existing economizers, including the tube bundles thereof, are welded together, a leak formed in a single tube may require each of the3604-00502tubes of the tube bundle to be cut from their respective tubesheets and tube manifolds to allow for the replacement of the individual leaking tube. The tubes may then be rewelded to the pair of tubesheets and tube manifolds prior to being leak tested to ensure the integrity of the newly formed welds. The process of shutting down the waste heat recovery system, removing the tube bundle from the outer housing of the economizer, cutting the tubes from the associated components of the tube bundle such that one or more selected tubes may be replaced, rewelding the tubes and associated components of the tube bundle, reinstalling the tube bundle in the outer housing, and pressure testing the reassembled economizer may result in a significant downtime for the waste heat recovery system, potentially resulting in a shutdown of the fluid system comprising the waste heat recovery system or at least a decline in the thermal efficiency of the fluid system.

[0043] Accordingly, embodiments disclosed herein include economizers for waste heat recovery systems that include a tube bundle including a plurality of separate heat transfer tubes (e.g., arranged in parallel) sealably and releasably connected to opposing inlet and discharge fluid conduits of the economizer to permit the convenient removal of one or more selected heat transfer tubes (e.g., leaking heat transfer tubes) without the need of cutting or otherwise separating permanently coupled (e.g., welded) components of the tube bundle to minimize the amount of time required for replacing the selected one or more heat transfer tubes.

[0044] For example, in some embodiments, the economizer may include an outer housing comprising a shell in which a tube bundle of the economizer is receivable, and a cover that may be releasably coupled to the shell to enclose an interior thereof. Additionally, the cover may include a plurality of tube openings through which a plurality of heat transfer tubes of the economizer are slidably insertable without needing to directly connect (e.g., weld) the heat transfer tubes to the cover. Instead, the economizer may include a plurality of seal assemblies coupled between the plurality of heat transfer tubes and the cover to seal the interfaces formed between the plurality of heat transfer tubes and the cover. In some embodiments, each seal assembly includes collar coupled (e.g., welded) to the cover, a connector coupled to the collar, and an annular seal (e.g., an annular packing gland, an O-ring seal and the like) trapped between the collar and the connector.

[0045] As described above, embodiments of economizers disclosed herein include a multi-part outer housing including a shell and a cover that is releasably coupled to the3604-00502shell to enclose an interior thereof in which a tube bundle of the economizer is received. In some embodiments, the cover and shell are coupled together via a plurality of separate fasteners such as threaded fasteners and the like. Alternatively, and as a means for minimizing the time required for assembling or disassembling the economizer, the shell and cover may be releasably coupled together via one or more clamping assemblies defining a pair of opposing clamping surfaces that apply opposing clamping forces to the shell and cover to secure the two together.

[0046] Referring initially to FIG. 1 , an embodiment of a waste heat recovery system 10 including an internal combustion engine (ICE) 12, an economizer 20, a control system 40, and an electrical generator 50. Generally, economizer 20 extracts waste heat from a hot exhaust stream 14 discharged by the ICE 12 as will be further described herein. In this exemplary embodiment, ICE 12 comprises a diesel engine. Alternatively, ICE 12 may consume other fuel sources such as natural gas and the like in other embodiments. Additionally, in other embodiments, ICE 12 may be used to drive or power various types of equipment such as a pumps, compressors, or other powered equipment. Further, ICE 12 acts as a source of waste heat in the form of flue gas exhaust that is at elevated temperatures such as, for example, between approximately 600 degrees Fahrenheit (°F) and up to or more than 1500°F.

[0047] The economizer 20 of waste heat recovery system 10 generally includes an outer housing 22, a tube bundle 24 received in an interior of the outer housing 22, an inlet fluid conduit 26 coupled to an upstream end of tube bundle 24, and an outlet or discharge fluid conduit 28 coupled to an opposing downstream end of tube bundle 24. Economizer 20 is configured to discharge a cooled exhaust stream 16 from the discharge fluid conduit 28 thereof that is at a lower temperature than hot exhaust stream 14 received by the inlet fluid conduit 26 thereof. For example, in some embodiments, the difference in temperature between cooled exhaust stream 16 and hot exhaust stream 14 may be approximately between 800°F and 400°F in some embodiments. For instance, in an embodiment, hot exhaust steam 14 may be approximately between 700°F and 900°F and the cooled exhaust stream 16 may be approximately between 200°F and 400°F. However, the temperatures of streams 14 and 16 and the differential therebetween may vary in other embodiments.

[0048] Economizer 20 is fluidically connected to the generator 50 via a heated process stream 52 discharged from the economizer 20 and received by the generator 50, and a corresponding cooled process stream 54 discharged from the generator 50 and3604-00502received by the economizer 20. In this exemplary embodiment, process flow comprises water (not necessarily liquid water) and is used to facilitate the operation of generator 50. The cooled process stream 54 received by economizer 20 may flow into and through the interior of outer housing 22 where it is heated (indicated schematically by arrows 25) by the exhaust flow passing through tube bundle 24 without contacting the exhaust flow itself. Instead, the process flow within outer housing 22 may be external the tubes of tube bundle 24 (e.g., on a shellside of economizer 20) while the exhaust flow is on the interior of the tubes (e.g., on a tubeside of economizer 20).

[0049] The process flow is cooled in generator 50 such that at least some energy (e.g., heat) from the heated process stream 52 received by generator 50 is transferred to the generator 50 for performing work such as driving a turbine of the generator 50, for instance. In this manner, energy in the form of heat may be transferred from the hot exhaust stream 14 to the cooled process stream 54 via the economizer 20 whereby this transferred heat may be used to perform additional work via generator 50, thereby enhancing the thermal efficiency of the fluid system incorporating waste heat recovery system 10. In this manner, the cooled process stream 54 discharged from generator 50 is at a lower temperature in this exemplary embodiment than the heated process stream 52 received by the generator 50. As an example, the heated process stream 52 received by generator 50 may be between approximately 250°F and 300°F while the cooled process stream 54 may be between approximately 200°F and 250°F with the process flow being cooled in generator 50 by between approximately 20°F and 50°F. However, the temperatures of streams 52 and 54 and the differential therebetween may vary in other embodiments.

[0050] The control system 40 of waste heat recovery system 10 may monitor (and potentially control) one or more parameters of system 10. Particularly, in this exemplary embodiment, control system 40 includes a first or hot sensor 42 and a second or cold sensor 44. Hot sensor 42 is in fluid communication with heated process stream 52 and is configured to monitor one or more parameters (e.g., temperature, pressure, flow rate) of heated process stream 52 while cold sensor 44 is in fluid communication with cooled process stream 54 and is configured to monitor one or more parameters (e.g., temperature, pressure, flow rate) of heated process stream 54. Control system 40 may indicate these measured parameters to an operator of waste heat recovery system 10, and / or control powered equipment (e.g., remotely operable valving and the like) of waste heat recovery system 10.3604-00502

[0051] The tube bundle 24 of economizer 20 includes a plurality of separate tubes (e.g., supported between a pair of opposed tubesheets) each in fluid communication with fluid conduits 26 and 28 for sealingly transporting the exhaust stream discharged by ICE 12 through the interior of outer housing 22 without allowing the exhaust stream to mix or otherwise come into contact with another fluid (e.g., water) located in the interior of outer housing 22 external tube bundle 24. In some embodiments, the individual tubes of tube bundle 24 are simple rectilinear tubes extending between their upstream and downstream ends while in other embodiments each tube may comprise a plurality of rectilinear or straight sections interconnected by a series of ninety degree bends or elbows whereby each tube extends serpentine through the interior of outer housing 22. In some embodiments, tube bundle 24 may be extracted from the interior of outer housing 22 when desired such as for repairing or replacing components of tube bundle 24. In certain embodiments, fluid conduits 26 and 28 may remain coupled with tube bundle 24 following the extraction of tube bundle 24 from outer housing 22.

[0052] I this exemplary embodiment, tube bundle 24 is not permanently coupled to the outer housing 22 and instead may be extracted therefrom. Particularly, tube bundle 24 is sealed coupled to fluid conduits 26 and 28 via a plurality of sealed, inlet seal assemblies 30 and corresponding discharge seal assemblies 32. The seal assemblies 30 and 32 provide fluidically sealed connections between the tubes of tube bundle 24 and fluid conduits 26 and 28, respectfully.

[0053] One or more tubes of tube bundle 24 may be extracted from the outer housing 22 without needing to cut the tube bundle 24 therefrom - thereby avoiding the time and expense associated with rewelding or otherwise re-permanently coupling features of the tubes to the outer housing 22. Instead, should one or more tubes of the tube bundle 24 need to be repaired or replaced during operation of economizer 20 (e.g., due to the formation of a leak in the one or more tubes), those selected one or more tubes may be individually cut from the inlet and discharge fluid conduits connected to economizer and mechanically disconnected (e.g., slidably released) from outer housing 22 without the need for cutting, breaking, or otherwise permanently disconnecting the selected one or more tubes from the outer housing 22. This allows for the quick and convenient replacement of the selected one or more tubes without welding or, alternatively, simply replacing the entire tube bundle 24 (or at least all of the tubes thereof) given the difficulty associated with removing one or more3604-00502permanently coupled (e.g., welded) tubes such as the case with conventional tube bundles.

[0054] Referring to FIGS. 2-4, an embodiment of an economizer 100 is shown. In some embodiments, the economizer 20 shown in FIG. 1 may take the form or otherwise include features in common with economizer 100. In certain embodiments, economizer 100 may be used in fluid systems which vary in configuration from the waste heat recovery system 10. Economizer 100 generally includes an outer housing 102, a tube bundle 120 receivable in an interior 103 of the outer housing 102 and comprising a plurality of heat transfer tubes 140, an inlet fluid conduit 170 in fluid communication with tube bundle 120, and a discharge fluid conduit 190 in fluid communication with a discharge side of tube bundle 120.

[0055] In this exemplary embodiment, the outer housing 102 of economizer 100 generally includes a shell 104 and a cover 106 that may releasably couple with shell 104 to form outer housing 102. Particularly, outer housing 102 includes a closed or assembled configuration in which shell 104 is releasably coupled with cover 106 via a plurality of releasable connectors or fasteners 112 (only some of which are labeled in FIGS. 2-4 for clarity) coupled between shell 104 and cover 106. Outer housing 102 additionally includes a disassembled or open configuration in which cover 106 is mechanically disconnected or decoupled from shell 104 whereby the tube bundle 120 (remaining coupled to cover 106 but not to shell 104) may be extracted from the interior 103 of outer housing 102 such as for servicing or repair.

[0056] For example, releasable fasteners 112 may comprise a screw or bolt that extends openings formed in the cover 106 and shell 104 and which is threadably coupled to a corresponding nut. Alternatively, the configuration of releasable fasteners 112 may vary in other embodiments from that shown in FIGS. 2-4. For instance, in other embodiments, releasable fasteners 112 may be formed integrally or monolithically with shell 104 and / or cover 106. In still other embodiments, economizer 100 may not include releasable fasteners for coupling cover 106 with shell 104 and, instead, shell 104 may couple directly to cover 106 via a friction fit, an interference fit, a snap fit, and the like.

[0057] Additionally, in this exemplary embodiment, shell 104 of outer housing 102 comprises a pair of opposing flanged openings 108 for providing fluid communication into and from the interior 103 of outer housing 102. For example, the interior of 103 outer housing 102 may receive a shellside inlet fluid stream 105 at a first flanged3604-00502opening 108 thereof and outlet a shellside discharge fluid stream 107 from an opposing second flanged opening 108 thereof. In some embodiments, the fluid flow received by interior 103 of outer housing 102 via flanged openings 108 may be a process fluid stream such as the cooled process stream 54 shown in FIG. 1. In this manner, the fluid stream received by a flanged opening 108 of outer housing 102 may exchange heat with a fluid stream passing through the tube bundle 120 (while remaining sealed from the fluid passing through tube bundle 120) in the interior 103 of outer housing 102 before being discharged from the interior 103 via the other flanged opening 108.

[0058] As will be described further herein, tube bundle 120 of economizer is in fluid communication with fluid conduits 170 whereby an upstream side of tube bundle 120 is configured to receive a tubeside inlet fluid stream 171 while a downstream side of tube bundle 120 is configured to outlet a tubeside discharge stream 191. In this exemplary embodiment, inlet fluid conduit 170 comprises a generally cylindrical inlet manifold 172 having a flanged opening 174. Referring briefly to FIGS. 9 and 10, inlet fluid conduit 170 includes a plurality of radial openings 176 (shown in FIG. 9) spaced along the longitudinal length of inlet manifold 172. The heat transfer tubes 140 of tube bundle 120 may connect to inlet manifold 172 at the radial openings 176 thereof. Particularly, inlet terminal ends 143-1 of the heat transfer tubes 140 are at least partially received in radial openings 176 and the annular interface formed therebetween is sealed. In some embodiments, the annular interfaces formed between heat transfer tubes 140 and radial openings 176 may be welded to couple or affix the heat transfer tubes 140 to the inlet manifold 172. In this configuration, tubeside inlet fluid stream 171 may first flow into inlet manifold 172 via flanged opening 174, and then from inlet manifold 172 the tubeside inlet fluid stream 171 may divide and enter the plurality of heat transfer tubes 140 of the tube bundle 120.

[0059] Similarly, discharge fluid conduit 190 comprises a generally cylindrical discharge manifold 192 having a flanged opening 194. Additionally, discharge fluid conduit 190 includes a plurality of radial openings 196 spaced along the longitudinal length of discharge manifold 192. The heat transfer tubes 140 of tube bundle 120 may connect to discharge manifold 192 at the radial openings 196 thereof. Particularly, discharge terminal ends 143-2 of the heat transfer tubes 140 are at least partially received in radial openings 196 and the annular interface formed therebetween is sealed. In some embodiments, the annular interfaces formed between heat transfer3604-00502tubes 140 and radial openings 196 may be welded to couple or affix the heat transfer tubes 140 to the discharge manifold 192. In this configuration, tubeside discharge fluid stream 191 may first flow from the discharge side of tube bundle 120 and into the discharge manifold 192. Additionally, from discharge manifold 192, the tubeside discharge fluid stream 191 may exit economizer 100 via the flanged opening 194.

[0060] Referring to FIGS. 4-10, additional views of the tube bundle 120 and fluid conduits 170 and 190 are provided in FIGS. 5-10. In this exemplary embodiment, tube bundle 120 generally includes cover 106a pair of opposing tubesheets 126, a plurality of elongate support members or rails 130, the plurality of heat transfer tubes 140, and a plurality of annular seal assemblies 150 (only some of the heat transfer tubes 140 and seal assemblies 150 are labeled in FIGS. 4-10 for clarity). In this exemplary embodiment, the cover 106 of outer housing 102 interfaces with tube bundle 120 and cover 106is rectangular in shape and has a plurality of fastener receptacles 109 spaced along a perimeter thereof for receiving the plurality of fasteners 112 to couple or secure the cover 106 to the shell 104 of outer housing 102. Additionally, cover 106 includes a pair of rows of tube openings 111 through which the terminal ends 143 of heat transfer tubes 140 are slidably receivable. Particularly, heat transfer tubes 140 are not directly coupled or mounted to the cover 106 permitting the slidable removal of selected heat transfer tubes 140 therefrom. The shape or configuration of cover 106 may vary in other embodiments. Moreover, the manner in which tube bundle 120 mounts to outer housing 102 may vary in other embodiments.

[0061] In this exemplary embodiment, support rails 130 each extend from the cover 106 and are located along the outer periphery of tube bundle 120 (e.g., at the four corners thereof in this exemplary embodiment). Additionally, tubesheets 126 are received within the plurality of spaced support rails 130 with a first or inner tubesheet 126-1 being positioned between a first or inner end of the plurality of heat transfer tubes 140 and the cover 106 and a second or outer tubesheet 126-2 being positioned at an opposing second or outer end of the plurality of heat transfer tubes 140. In this manner, the inner tubesheet 126-1 physically supports the plurality of heat transfer tubes 140 at the inner ends thereof while the opposing outer tubesheet 126-2 physically supports the plurality of heat transfer tubes 140 at the opposing outer ends thereof. Particularly, each tubesheet 126 may couple to each of the plurality of heat transfer tubes 140 via a releasable connection such as a friction fit and the like to permit the disassembly of tube bundle 120. In this configuration, structural and other3604-00502mechanical loads applied to heat transfer tubes 140 may be transferred to tubesheets 126, and from tubesheets 126 to the cover 106 via the plurality of support rails 130 coupled between the cover 106 and tubesheets 126. Further, these mechanical loads may be transferred to the cover 106 of outer housing 102 via the plurality of releasable fasteners 112 coupled between cover 106 and cover 106.

[0062] As shown particularly in FIG. 7, each heat transfer tube 140 of tube bundle 120 is generally serpentine in shape winding from an upper end (as shown in FIG. 7) of the tube bundle 120 to a lower end of the tube bundle 120. Particularly, in this exemplary embodiment, each heat transfer tube 140 includes a plurality of parallel and generally linear or rectilinear tubes 142 spaced between the upper and lower ends of tube bundle 120. Each rectilinear tube 142 includes a plurality of annular fins which project radially outwards from the rectilinear tube 142 and which are spaced along the longitudinal length of the rectilinear tube 142. The annular fins increase the surface area of heat transfer tubes 140 to maximize heat transfer between fluid flowing through heat transfer tubes 140 and fluid external tubes in the interior 103 of outer housing 102. In other embodiments, the shape of the fins may vary in other embodiments. In still other embodiments, rectilinear tubes 142 may not include fins. Rectilinear tubes 142 are arrayed in a grid-like pattern (shown in FIG. 8, for example) with the rectilinear tubes 142 of a single heat transfer tube 140 spaced along columns of the grid pattern and the rectilinear tubes 142 of different heat transfer tubes 140 spaced orthogonally along rows of the grid pattern.

[0063] Additionally, in this exemplary embodiment, rectilinear tubes 142 are fluidically and mechanically interconnected by a plurality of corresponding ninety degree bends or elbows 144 located at the inner and outer ends of tube bundle 120. For clarity elbows 144 are labeled in FIG. 7 as inner elbows 144-1 (spaced along the inner end of tube bundle 120) and outer elbows 144-2 (spaced along the outer end of tube bundle 120). Elbows 144 interconnect the different rectilinear tubes 142 of a given heat transfer tube 140 to provide the heat transfer tube 140 with its serpentine shape. In other embodiments, heat transfer tubes 140 may not include elbows 144 and instead may include only a single linear (e.g., rectilinear) tube.

[0064] Heat transfer tubes 140 each fluidically and mechanically connect with a different inlet opening 176 of inlet fluid conduit 170 and a different discharge opening 196 of discharge fluid conduit 190. Particularly, seal assemblies 150 seal the annular interface formed between each heat transfer tube 140 and the corresponding tube3604-00502opening 111 of cover 106 through the which the heat transfer tube 140 extends. Additionally, each seal assembly 150 seals the interface formed between a corresponding heat transfer tube 140 and the cover 106 while permitting the heat transfer tube 140 to be slidably released or removed from both the seal assembly 150 and cover 106. In other words, the heat transfer tube 140 may be slid through both the seal assembly 150 and the tube opening 111 of cover 106 through which it extends to release the heat transfer tube 140 from the seal assembly 150 and cover 106. In this manner, should it be desired to remove one or more selected heat transfer tubes 140 from the tube bundle 120 of economizer 100 (such as due to the formation of a leak in the one or more selected heat transfer tubes 140), those selected one or more heat transfer tubes 140 may be quickly and conveniently releasably disconnected and repaired or replaced.

[0065] Referring to FIGS. 11 and 12, additional views of one of the seal assemblies 150 is shown. In this exemplary embodiment, each seal assembly 150 comprises an annular outer collar 152, a second or inner coupler 160, and an annular seal 165 positioned between the collar 152 and inner coupler 160 for sealing the interface formed between a given heat transfer tube 140 and the tube opening 111 of cover 106 through which it extends.

[0066] In some embodiments, collar 152 is coupled to the cover 106 whereby relative movement is restricted therebetween. For example, collar 152 may be welded or otherwise permanently coupled to the cover 106. The collar 152 of seal assembly 150 extends longitudinally between a first end 153 and an opposing second end 154 coupled to the cover 106. Additionally, collar 152 includes an inner surface 156 extending between ends 153 and 154. Inner surface 156 defines an annular, radially extending internal shoulder 158 that is located between ends 153 and 154. Additionally, in this exemplary embodiment, at least a portion of the inner surface 156 is threaded between the first end 153 and internal shoulder 158 such that collar 152 is internally threaded.

[0067] The inner coupler 160 extends longitudinally between a first end 162 and an opposing second end 164 and includes an outer surface 166 extending between ends 162 and 164. In this exemplary embodiment, outer surface 166 defines an interface 168 (e.g., a hexagonal interface) which a tool (e.g., a manually operated or self-powered wrench) may be applied for applying a rotational torque to the inner coupler 160 about a longitudinal axis of the seal assembly 150. Additionally, in this exemplary3604-00502embodiment, at least a portion of the outer surface 166 is threaded between ends 161 and 163 such that inner coupler 160 is externally threaded. Further, the threaded outer surface 166 of inner coupler 160 is configured to releasably and matingly or threadably engage with the threaded inner surface 156 of collar 152 to mechanically (e.g., threadably) connect the inner coupler 160 with the collar 152. In other embodiments, the releasable connection formed between collar 152 and inner coupler 160 may comprise a releasable connection other than the threaded connection as shown in FIG. 12.

[0068] When the inner coupler 160 is threadably coupled to the collar 152, an annular receptacle 167 is formed that extends longitudinally between the second end 163 of inner coupler 160 and the internal shoulder 158 of collar 152 and which receives the annular seal 165. In some embodiments, annular seal 165 comprises a packing gland formed from an elastomeric or otherwise deformable material configured to seal the interface formed between the heat transfer tube 140 and the mounting plate 122. In some embodiments, annular seal 165 comprises an O-ring seal and the like; however, the configuration of annular seal 165 may vary substantially depending on the given application (e.g., fluid pressures, fluid temperatures, fluid compositions).

[0069] In this exemplary embodiment, at least a portion of annular seal 165 is longitudinally trapped in receptacle 167 between internal shoulder 158 of collar 152 and the second end 163 of inner coupler 160. By threading the inner coupler 160 further into the collar 152 (e.g., displacing the inner coupler 160 towards the right in FIG. 10), the longitudinal width of annular receptacle 167 is reduced thereby longitudinally compressing the annular seal 165. Longitudinal compression of annular seal 165 deforms annular seal 165 thereby increasing a sealing contact pressure between the annular seal 165 and both the inner surface 156 of collar 152 and outer surface of heat transfer tube 140. In some embodiments, annular seal 165 may extend entirely to the second end 154 to sealingly contact the mounting plate 122 to seal the annular interface formed between collar 152 and cover 106. Alternatively, a separate seal or sealing mechanism may seal this annular interface. For instance, the second end 154 of collar 152 may be welded to cover 106 to seal the annular interface therebetween.

[0070] Referring to FIGS. 13-15, additional views of the economizer 100 are provided. Particularly, FIGS. 13-15 illustrate an exemplary removal of a selected heat transfer tube 140 from the tube bundle therefrom. FIG. 13 illustrates the cutting of the inlet end3604-00502143-1 of a selected heat transfer tube 140’ forming a cut inlet end 145-1 of the selected heat transfer tube 140’ that is spaced and disconnected from the inlet end 143-1 and inlet manifold 172. Although not shown in FIG. 13, the discharge end 143-2 of the selected heat transfer tube 140’ may similarly be cut to form a discharge cut end 145-2 that is spaced and disconnected from the discharge end 143-2 and discharge manifold 192.

[0071] Following the cutting of the selected heat transfer tube 140’, the selected heat transfer tube 140’ may be extracted from the tube bundle 120 as shown particularly in FIG. 14. Particularly, the outer tubesheet 126-2 may be disconnected from support rails 130 (e.g., via removing one or more fasteners, such as threaded fasteners, connected therebetween). With the outer tubesheet 126-2 removed, the selected heat transfer tube 140’ may be slid outwardly from the cover 106 and inner-tube sheet 126-1 , with the cut ends 145 of the selected heat transfer tube 140’ sliding through the seal assembly 150 and the tube opening 111 of cover 106.

[0072] As shown particularly in FIG. 15, with the selected heat transfer tube 140’ extracted from tube bundle 120, endcaps 173 may be attached (e.g., welded) to the inlet and discharge ends 143-1 and 143-2 of the selected heat transfer tube 140’ (which are now disconnected from the heat transfer tube 140’) to seal the manifolds 172 and 192 from the external environment. Additionally, the inner couplers 160 of the seal assemblies 150 formerly in sealing engagement with selected heat transfer tube 140’ are replaced by solid plugs 180 which may be externally threaded to threadably connect to the collars 152 of the seal assemblies 150. In this manner, plugs 180 may seal the interfaces between the now modified seal assemblies 150’ and the cover 106. In some embodiments, the selected heat transfer tube 140’ (or a portion thereof) may be returned to the tubesheet 126 to ensure the flow of fluid around the heat transfer tubes 140 during operation of economizer 100 is undisturbed.

[0073] Referring to FIGS. 16 and 17, another embodiment of an economizer 200 is shown. Economizer includes features in common with economizer 100 shown in FIGS. 2-15, and shared features are labeled similarly. Particularly, in this exemplary embodiment, economizer 200 generally includes a support structure or skid 202, an outer housing 220, tube bundle 120 receivable in an interior 203 of the outer housing 220, inlet fluid conduit 170 in fluid communication with tube bundle 120, discharge fluid conduit 190 in fluid communication with a discharge side of tube bundle 120, and one or more clamping assemblies 240.3604-00502

[0074] In this exemplary embodiment, skid 202 of economizer 200 includes a raised support surface 204 that is vertically spaced from the ground or other surface upon which a vertically lower end 206 of the skid 202 is positioned. Additionally, in this exemplary embodiment, outer housing 220 of economizer 200 includes a shell 222 and a cover 230 releasably connectable to the shell 222. Shell 222 extends between a vertically lower end 223 and a vertically upper end 225 where the vertically upper end 225 of shell 222 is open to the external environment when not covered by and connected with the cover 230 of outer housing 220.

[0075] Shell 222 is similar to the shell 104 of economizer 100 except that the open end of shell 222 is located at the vertically upper end 225 thereof and shell 222 includes one or more feet 226 positioned at the vertically lower end 223 thereof. Feet 226 are landable against the support surface 204 of skid 202 whereby the shell 222 may be physically supported by skid 202. In some embodiments, each foot 226 comprises one or more fasteners for securing the shell 222 to the skid 202. In this arrangement, shell 222 may be vertically lowered (indicated by arrow 205 in FIG. 16) onto the support surface 204 of skid 202 during the initial installation of economizer 200. Similarly, following the lowering of shell 222 onto skid 202, tube bundle 120 and cover 230 may similarly be vertically lowered such that the tube bundle 120 is received in the interior 203 of shell 222. For instance, cover 230 includes one or more connectors or lifting eyes 232 in this exemplary embodiment to facilitate coupling cover 230 and the tube bundle 120 coupled therewith with a lifting device such as a crane and the like. In this manner, the cumbersome maneuver of transporting the tube bundle 120 horizontally into the shell 222 may be avoided which may require specialized tooling and equipment (beyond that of a crane) may be required.

[0076] Additionally, in this exemplary embodiment, rather than individual fasteners 112, cover 230 is secured or locked to the shell 222 using clamping assemblies 240 to minimize the time required for assembling and / or disassembling the economizer 200. Particularly, instead of torqueing a large number of fasteners 112 to a predefined torque in order to secure the cover 230 to the shell 222, only a small number of clamping assemblies 240(e.g., four clamping assemblies 240 in this exemplary embodiment) may be used to accomplish the same task. In some embodiments, it may not be required to precisely torque the clamping assemblies 240 in order to ensure a secure connection between the cover 230 and shell 222.3604-00502

[0077] As shown particularly in FIG. 17, in this exemplary embodiment, each clamping assembly 240 generally includes a first or upper clamping member 242, a second or lower clamping member 260, and a plurality of fasteners 280 spaced along the clamping members 242 and 260. Particularly, upper clamping member 242 has a generally L-shaped cross-section and includes a first or upper end 244 and an opposing second or lower end 246. A plurality of recesses or slots 248 are spaced longitudinally along the lower end 246 of upper clamping member 242 Additionally, upper clamping member 242 defines a first or upper clamping surface 250 opposing upper end 244 but spaced from the lower end 246 thereof. Further, upper clamping member 242 comprises a plurality of openings or receptacles 252 spaced longitudinally along the upper clamping member 242. Particularly, each receptacle 252 extends from the upper end 244 to the lower end 246 thereof and is configured to slidingly receive a corresponding fastener 280 of clamping assembly 240.

[0078] Lower clamping member 260 has a first a or lower clamping surface 264 located at an upper end thereof vertically aligned with but spaced from the upper clamping surface 250 of upper clamping member 242. In this exemplary embodiment, lower clamping member 260 includes a plurality of laterally extending fingers 262 longitudinally spaced along the lower clamping member 260. Fingers 262 of lower clamping member are interleaved with the slots 248 formed in upper clamping member 242 whereby fingers 262 are a last partially receivable in slots 248 during the operation of clamping assembly 240. Additionally, in this exemplary embodiment, each finger 262 includes an internally threaded receptacle 266 each extending into the upper end of lower clamping member 260. Threaded receptacles 266 are vertically aligned with receptacles 252 of upper clamping member 242 such that each fastener 280 may be inserted into both a receptacle 252 of upper clamping member 242 and a corresponding and aligned threaded receptacle 266 of lower clamping member 260 to couple the upper clamping member 242 to the lower clamping member 260 whereby a clamping force may be applied between the clamping surfaces 250 and 264 thereof.

[0079] Particularly, fasteners 280 may be slidably inserted through the receptacles 252 of upper clamping member 242 and subsequently threaded into the threaded receptacles 266 of lower clamping member 260. Each fastener 280 includes an externally threaded shank 282 configured to matingly and threadably connect to the internally threaded receptacles 266. Threaded engagement of fasteners 280 with threaded receptacles 266 drives the lower clamping surface 264 of lower clamping3604-00502member 260 linearly towards the upper clamping surface 250 of upper clamping member 242 reducing a distance or width of a clamping opening 265 formed therebetween.

[0080] During the assembly of economizer 200, a portion of the outer perimeters of the vertically upper end 225 of shell 222 and cover 230 may each be inserted into the clamping opening 265 of a given clamping assembly 240. The shanks 282 of fasteners 280 may then be threaded through the threaded receptacles 266 of lower clamping member 260 to reduce the width of clamping opening 265 whereby the lower clamping surface 264 may engage and apply a clamping force to the vertically upper end 225 of shell 222 while the upper clamping surface 250 of upper clamping member 242 contacts and applies a corresponding and opposing clamping force to the cover 230 to thereby clamp the vertically upper end 225 of shell 222 to the cover 230. This process may be repeated for each clamping assembly 240 of economizer 200 whereby a sufficient clamping force is applied relatively equally along the perimeters of the vertically upper end 225 of shell 222 and cover 230.

[0081] Referring to FIGS. 18 and 19, another embodiment of an economizer 300 is shown. Economizer includes features in common with economizer 100 shown in FIGS. 2-15 and economizer 200 shown in FIG. 16, and shared features are labeled similarly. Particularly, economizer 300 is similar to the economizer 200 shown in FIG.16 except that, instead of clamping assemblies 240 for coupling the cover 230 to the shell 222 thereof, economizer 300 includes a plurality of clamping assemblies 302 which vary in configuration from clamping assemblies 240.

[0082] As shown particularly in FIG. 19, each clamping assembly 302 generally includes a first or upper clamping member 310, a second or lower clamping member 330, and a single fasteners 280. Upper clamping member 310 has a generally L-shaped cross-section and includes a first or upper end 312 and an opposing second or lower end 314. A single recess or slot 316 is formed along the lower end 314 of upper clamping member 310. Additionally, upper clamping member 310 defines a first or upper clamping surface 318 opposing upper end 312 but spaced from the lower end 314 thereof. Further, upper clamping member 310 comprises a single opening or receptacle 320.

[0083] Lower clamping member 330 has a first a or lower clamping surface 334 located at an upper end thereof vertically aligned with but spaced from the upper clamping surface 318 of upper clamping member 310. In this exemplary embodiment,3604-00502lower clamping member 330 includes a single laterally extending finger 332 longitudinally spaced along the lower clamping member 330. Finger 332 of lower clamping member 330 is aligned with the slot 316 formed in upper clamping member 310 whereby finger 332 is a last partially receivable in slot 316 during the operation of clamping assembly 302. Additionally, in this exemplary embodiment, each finger 332 includes an internally threaded receptacle 336 extending into the upper end of lower clamping member 330. Threaded receptacle 336 is vertically aligned with receptacle 320 of upper clamping member 310 such that fastener 280 may be inserted into both receptacle 320 of upper clamping member 310 and the threaded receptacle 336 of lower clamping member 330 to couple the upper clamping member 310 to the lower clamping member 330 whereby a clamping force may be applied between the clamping surfaces 318 and 334 thereof.

[0084] Referring to FIGS. 20-24, an embodiment of an economizer 400 is shown. In some embodiments, the economizer 20 shown in FIG. 1 may take the form or otherwise include features in common with economizer 400. In certain embodiments, economizer 400 may be used in fluid systems which vary in configuration from the waste heat recovery system 10. In this exemplary embodiment, economizer 400 generally includes an outer housing 402, an inlet fluid conduit or manifold 430, a discharge fluid conduit or manifold 450, a plurality of first tube cartridges 470 receivable in an interior 403 of the outer housing 402 and fluidically connected to manifolds 430 and 450, and a plurality of second tube cartridges 500 also receivable in the interior 403 of the outer housing 402 and fluidically connected to manifolds 430 and 450.

[0085] In this exemplary embodiment, the outer housing 402 of economizer 400 generally includes a shell 404 and a cover 406 that may releasably couple with shell 404 to form outer housing 402. Additionally, shell 404 comprises a pair of opposing flanged openings or plenums 408 for providing fluid communication into and from the interior 403 of outer housing 402. For example, the interior of 403 outer housing 402 may receive a shellside inlet fluid stream at a first opening 408 thereof and outlet a shellside discharge fluid stream from an opposing second opening 408 thereof. In some embodiments, the fluid flow received by interior 403 of outer housing 402 via flanged openings 408 may be a process fluid stream such as the cooled process stream 54 shown in FIG. 1. In this manner, the fluid stream received by a flanged opening 108 of outer housing 102 may exchange heat with a fluid stream passing3604-00502through the plurality of tube cartridges 470 and / or 500 in the interior 403 of outer housing 402 before being discharged from the interior 403 via the other opening 408.

[0086] Outer housing 402 includes a closed or assembled configuration in which shell 404 is releasably coupled with cover 406 via a plurality of releasable connectors or fasteners (e.g., threaded fasteners such as studs or bolts) coupled between shell 404 and cover 406. Outer housing 402 additionally includes a disassembled or open configuration in which cover 406 is mechanically disconnected or decoupled from shell 404 whereby individual tube cartridges 470 and / or 500 may be slidably extracted from the interior 103 of outer housing 402 such as for servicing or repair.

[0087] In this exemplary embodiment, outer housing 402 includes an internal support structure or frame 410 received in the interior 403 thereof. As shown particularly in FIG. 23, support frame 410 includes a plurality of dividers 412 each extending longitudinally between a rear panel 405 (hidden from view in FIGS. 22-24) of the shell 404 and the cover 406. Additionally, a first or upper plurality of the dividers or rails 412 are positioned along or proximal to an upper panel 407 of the shell 404 while a second or lower plurality of rails 412 are positioned along or proximal to an opposing lower panel 409 of shell 404. Rails 412 extend orthogonal a longitudinal or central axis 401 Of economizer 400 and form or define a plurality of generally rectangular slots 415 extending orthogonal to and spaced along the central axis 401. Particularly, each slot 415 is positioned between a corresponding pair of upper rails 412 and lower rails 412. Each slot 415 has a width sized to receive a corresponding tube cartridge 470 or 500 whereby, once slidably received in the slot 415, the tube cartridge 470 or 500 is restricted from moving laterally or pivoting within the interior 403 of outer housing 402.

[0088] Additionally, one or more releasable fasteners (e.g., threaded fasteners) 418 (shown in FIG. 22) may secure tube cartridges 470 and 500 to the support frame 410 such that relative movement between the tube cartridges 470 and 500 and the outer housing 402 is restricted. For instance, a single leaking tube cartridge 470 or 500 may be individually removed and replaced from economizer 400 without needing to perform a single cut or weld such that only releasable fasteners (e.g., threaded fasteners) need be operated on to perform the replacement. In this manner, individual tube cartridges 470 and / or 500 may be selectably removed and replaced in the economizer 400 using only releasable fasteners and without needing to employ any cutting or welding, vastly simplifying the work required with replacing individual tube cartridges 470 and / or 500.3604-00502

[0089] Referring to FIGS. 25 and 26, a first tube cartridge 470 of economizer 400 is shown to facilitate further discussion thereof. In this exemplary embodiment, each first tube cartridge 470 includes a generally rectangular tube chassis 472 formed from one or more support members or plates and a heat transfer tube 480 coupled to and physically supported by the tube chassis 472. Tube chassis 472 may include one or more openings or receptacles for receiving fasteners 418 whereby fasteners 418 may releasably couple or secure the tube chassis 472 to the support frame 410 of outer housing 402 as previously described. Additionally, tube chassis 472 is configured to fit snugly within a corresponding slot 415 of outer housing 402 such that, prior to being secured by releasable fasteners 418, tube cartridge 470 is generally only permitted to slide longitudinally through the slot 415 and is not permitted to pivot or travel laterally within interior 403 of outer housing 402.

[0090] Similar to heat transfer tubes 140 described above, heat transfer tube 480 includes a plurality of rectilinear tubes 482 and a plurality of ninety degree bends or elbows 484 fluidically interconnecting rectilinear tubes 482. In this configuration, heat transfer tube 480 extends back-and-forth in a serpentine manner through the tube chassis 472. Additionally, each heat transfer tube 480 includes a pair of ends (e g., a fluid inlet and a fluid outlet) 486 formed on a pair of the rectilinear tubes 482 thereof. Ends 486 each include an externally threaded connector 488 for releasably coupling the heat transfer tube 480 to the manifolds 430 and 450 of economizer 400, as will be discussed further herein. In some embodiments, ends 486 of heat transfer tube 480 comprise threaded nipples that are welded onto terminal ends of the pair of rectilinear tubes 482; however, in other embodiments, the configuration of ends 486 may vary.

[0091] Referring to FIGS. 27 and 28, in this exemplary embodiment, each tube cartridge 470 and 500 is fluidically connected to each manifold 430 and 450 of economizer 400 by a seal assembly 550, a valve 570, and a fluid conduit 590. Seal assemblies 550 seal the interfaces formed between the ends 486 of heat transfer tubes 480 and openings 411 (shown in FIG. 28) formed in the rear panel 405 of shell 404 through which ends 486 extend from an interior 403 of outer housing 402 to an exterior thereof. In this exemplary embodiment, each seal assembly 550 generally includes an annular an annular outer seal collar 552, a second or inner coupler 560, and an annular seal 565 positioned between the collar 552 and inner coupler 560.

[0092] The seal collar 552 may be inserted into the opening 411 formed in rear panel 405 and an outer surface of the seal collar 552 may be welded or otherwise sealingly3604-00502coupled to the rear panel 405 to seal the annular interface formed between the seal collar 552 and the rear panel 405. Additionally, the end 486 of heat transfer tube 480 may be slidably insertable through a central passage of the outer collar 552 when a first tube cartridge 470 comprising the heat transfer tube 480 is assembled with the shell 404. The annular seal 565 may be positioned in the central passage of seal collar 552 such that the end 586 of heat transfer tube 580 is stabbed or slid through both the seal collar 552 and seal 565. Seal 565 may comprise an elastomeric seal such as an O-ring seal, loose packing material, and / or other seals. In some embodiments, the inner coupler 560 of seal assembly 550 may be threaded into the central passage of seal collar 552 whereby a distal end of the inner coupler 560 engages or presses against the seal 565. In response to pressure from inner coupler 560, seal 565 is forcibly presses in sealing contact against both an inner surface of the seal collar 552 and an outer surface of the end 486 of heat transfer tube 480 to seal the annular interface formed therebetween. In this manner, seal assembly 550 may be conveniently assembled by threading the inner coupler 560 into the seal collar 552. In other embodiments, seal assembly 550 may be configured differently than is shown in FIGS. 1 and 28. For instance, in other embodiments, seal assembly 550 may comprise a metal-to-metal seal utilizing ferrules or other sealing members.

[0093] The valve 570 is coupled between the seal assembly 550 and the fluid conduit 590 and generally includes a valve body 572, a valve element 574 receivable in the valve body 572, and an actuator 576 for shifting the valve element 574 between an open position corresponding to an open state of valve 570 and a closed position associated with a closed state of valve 570. While actuator 576 is shown in FIG. 27 as comprising a manually operable handle, in other embodiments, actuator 576 may comprise a powered (e.g., electrically, hydraulically, or pneumatically powered) actuator that is remotely controllable. Additionally, the valve 570 is coupled to the fluid conduit 590 by a releasable (e.g., threaded) fitting 595 releasably coupled to the valve body 572 and which may be friction fit, bonded, welded, or otherwise sealingly coupled to an end of the fluid conduit 590. In some embodiments, fluid conduit 590 may be flexible comprising a flex hose and the like for minimizing the difficulty in assembling the fluid conduit 590 with the tube cartridges 470 and / or 500.

[0094] Valve 570 may be operated by actuator 576 to fluidically isolate an individual first tube cartridge 470 (or second tube cartridge 500 as will be discussed further herein) from manifolds 430 and 450. Particularly, when the valves 570 connected to a3604-00502selected first tube cartridge 470 are in the open state, fluid flow is freely permitted between the manifolds 430, 450 and the heat transfer tube 480 of the first tube cartridge 470. However, in response to shifting the valves 570 into their closed states, fluid communication is restricted between the heat transfer tube 480 of the first tube cartridge 470 and both manifolds 430 and 450. In this manner, an individual first tube cartridge 470 may be fluidically isolated from manifolds 430 and 450 (e.g., for repair or replacement) without needing to take the economizer 400 out of service. In other words, only the individual first tube cartridge 470 may be taken out of service with the remaining tube cartridges 470 and 500 of economizer 400 remaining in service transferring heat with fluid conveyed through the interior 403 of outer housing 402.

[0095] Additionally, in this exemplary embodiment, a test port 598 is located between the valve 570 and the end 486 of the heat transfer tube 480 of each first tube cartridge 470. While test port 598 is shown formed in the valve body 572 of valve 570 in FIG.28, in other embodiments, test port 598 may be located instead between valve 570 and the end 486 of the heat transfer tube 480 or even in the end 486 of heat transfer tube 480 itself but external outer housing 402. Although not shown in FIGS. 27 and 28, test ports 598 may also be used in conjunction with second tube cartridges 500 in a manner similar to that described above with respect to first tube cartridges 470.

[0096] Test port 598 provides a convenient means for individually pressure testing each tube cartridge 470 and 500 of economizer 400 to determine the specific location of a leak within the economizer 400 without needing to take the economizer 400 entirely out of service. Instead, a single tube cartridge 470 or 500 may be taken out of service to determine the location of the leak while the economizer 400 remains in service transferring heat between fluid travelling through the interior 403 of outer housing 402 and fluid travelling through the remaining tube cartridges 470 and 500. Additionally, upon determining the location of the leak, the single leaking tube cartridge 470 or 500 may be removed and replaced while the economizer 400 remains in service, eliminating the need of altering the overall process or utilizing redundant economizers in order to have one available should one need to be taken offline to have its entire tube bundle repaired or replaced.

[0097] As an example, an individual tube cartridge 470 or 500 may be pressure tested by closing the valves 570 coupled to each end 486 of the heat transfer tube 480 of the tube cartridge 470, for example, thereby isolating the heat transfer tube 480 from manifolds 430 and 450 and the flow of fluid travelling therethrough. With valves 5703604-00502closed, pressure may be applied (e.g., from an external pressure source) to one or both of the test ports 598 to pressurize the heat transfer tube 480 of the tube cartridge 470 to a setpoint pressure. The pressure may then be “shut in” such that pressure will remain at the setpoint pressure in the heat transfer tube 480 so long as the heat transfer tube 480 is not leaking. Thus, should pressure decline over time from the setpoint pressure after the heat transfer tube 480 has been shut in, then it may be inferred that the heat transfer tube 480 is actively leaking fluid and thus needs to be repaired or replaced.

[0098] Referring to FIGS. 29-31 , an additional view of one of the second tube cartridge 500 is shown in FIG. 29. In this exemplary embodiment, each second tube cartridge 500 includes a generally rectangular tube chassis 502 formed from one or more support members or plates and a cleaning tube 510 coupled to and physically supported by the tube chassis 502. Tube chassis 502 may include one or more openings or receptacles for receiving fasteners 418 whereby fasteners 418 may releasably couple or secure the tube chassis 502 to the support frame 410 of outer housing 402 as previously described. Additionally, tube chassis 502 is configured to fit snugly within a corresponding slot 415 of outer housing 402 similar to the tube chassis 472 of each first tube cartridge 470.

[0099] The cleaning tube 510 of each second tube cartridge 500 includes a plurality of rectilinear tubes 512 and a plurality of ninety degree bends or elbows 514 fluidically interconnecting rectilinear tubes 512. In this configuration, cleaning tube 510 extends back-and-forth in a serpentine manner through the tube chassis 472. Additionally, each cleaning tube 510 includes a pair of ends (e.g., a fluid inlet and a fluid outlet) 516 formed on a pair of the rectilinear tubes 512 thereof. The serpentine arrangement of the cleaning tubes 510 may be generally vertically stacked along a single column of cleaning tubes 510 rather than stacked in horizontally spaced pairs such as with heat transfer tubes 482 to more efficiently clean the heat transfer tubes 482.

[0100] In this exemplary embodiment, a plurality of fluid nozzles 520 are spaced longitudinally along each of the rectilinear tubes 512 of cleaning tube 510. Each fluid nozzle 520 is configured to emit a jet or spray of fluid from a rectilinear tube 512 towards the heat transfer tubes 480 of first tube cartridges 470 located near the particular second tube cartridge 500. Particularly, in this exemplary embodiment, nozzles 520 circumferentially spaced approximately 180 degrees from each other are spaced longitudinally along reach rectilinear tube 512 and configured to emit a spray3604-00502of fluid along a jet axis 525 that extends generally orthogonal the rectilinear tube 512 in both orthogonal directions (e.g., a first nozzle 520 spraying in a first orthogonal direction and a second nozzle 520 circumferentially spaced from the first nozzle 520 spraying in an opposing second orthogonal direction). In this manner, the spray of fluid may be distributed equally in each orthogonal direction such that the first tube cartridges 470 positioned along each side of the particular second tube cartridge 500 are sprayed by the nozzles 520 thereof. Moreover, given that a plurality of nozzles 520 are spaced along each rectilinear tube 512 of cleaning tube 510, the spray produced by nozzles 520 is spready relatively evenly across an entire surface area of each lateral side of the second tube cartridge 500.

[0101] As shown particularly in FIGS. 30 and 31, each nozzle 520 extends longitudinally along jet axis 525 between a first or proximal end 522 and an opposing second or distal end 524. Additionally, nozzle 520 includes a central passage 526 defined by an inner surface that includes a frustoconical section forming a reduced-diameter section 528 of central passage 526. The reduced-diameter section 528 of central passage 526 accelerates fluid flowing through central passage 526 such that the fluid is emitted from nozzle 520 along jet axis 525 at high velocity to maximize the dispersion of the fluid within the interior 403 of the outer housing 402. However, in other embodiments, nozzles 520 may be configured differently than they are shown in FIGS. 30 and 31.

[0102] The fluid spray emitted from nozzles 520 may be used to clean the heat transfer tubes 480 of first tube cartridges 470 to prevent or at least mitigate fouling of heat transfer tubes 480 during the operation of economizer 400, thereby increasing the reliability and longevity of the first tube cartridges 470 and minimize downtime or other operational issues with respect to economizer 400. Particularly, by distributing the spray of fluid relatively evenly across each lateral side of each second tube cartridge 500, and directing the fluid spray orthogonally directly towards and against the heat transfer tubes 480 of first tube cartridges 470, the efficacy of the cleaning and fouling prevention provided by second tube cartridges 500 may be maximized.

[0103] Process fluid received from inlet manifold 430 may be sprayed from nozzles 520 to clean the heat transfer tubes 480 of first tube cartridges 470. In some embodiments, a cleaning solution or other additives can be added to the process fluid received specifically by second tube cartridges 500 via test ports 598; however, in other embodiments, only the process fluid itself may be relied on for cleaning the heat3604-00502transfer tubes 480 of first tube cartridges 470. Additionally, second tube cartridges 500 may be individually isolated from or added to the process fluid flow received from inlet manifold 430 depending on the degree of cleaning is desired at a given point in time of the operation of economizer 400, with the degree of cleaning being conveniently adjustable via operating a small number of valves 570 of the economizer 400. Moreover, the number of second tube cartridges 500 included in the economizer 400 may be conveniently adjusted over time without needing to take economizer 400 offline via closing the valves 570 associated with a given slot 415 of outer housing 402, inserting a second tube cartridge 500 into the slot 415 and fluidically connecting the second tube cartridge 500 to the pair of valves 570, and then opening the pair of valves 570 to permit the process fluid to enter and flow through the cleaning tube 510 of the second tube cartridge 500. For instance, additional second tube cartridges 500 may be added (e.g., via swapping out with first tube cartridges 470 or adding to empty or spare slots 415 of outer housing 402).

[0104] More generally, the modularity provided by tube cartridges 470 and 500 allows for the number of first tube cartridges 470, and hence the heat transfer capacity of economizer 400, to be adjusted overtime without needing to take the economizer 400 offline. For instance, the economizer 400 may be initially installed with only 80% of its given slots 415 filled with tube cartridges 470 and 500, leaving additional spare capacity that may be used selectively in the future when it is desired to increase the heat transfer capacity of economizer 400 in response to, for instance, future changes in the fluid system in which the economizer 400 is incorporated (e.g., heat recovery system 10 shown in FIG. 1). Thus, the performance of economizer 400 may be adapted or adjusted over time to account for future changes to the overall fluid system without needing to add additional economizers 400 or otherwise take more drastic changes or alterations to account for these future changes to the fluid system.

[0105] Referring to FIG. 32, an exemplary method 600 for leak testing an economizer (e.g., economizer 400) of a waste heat recovery system (e.g., waste heat recovery system 10) is shown. Initially, at block 602, method 600 includes fluidically isolating a selected tube cartridge (e.g., tube cartridges 470 and 500) of a plurality of tube cartridges of the economizer from both an inlet fluid conduit (e.g., inlet fluid conduit 430) defining a tubeside inlet of the economizer and a discharge fluid conduit (e.g., discharge fluid conduit 450) defining a tubeside discharge of the economizer.3604-00502

[0106] At block 604, method 600 includes pressurizing a heat transfer tube (e.g., heat transfer tubes 480 and 510) of the selected tube cartridge to a test pressure. At block 606, method 600 includes ceasing further pressurization of the heat transfer tube once the test pressure in the heat transfer tube has been achieved to initiate a leak monitoring period. At block 608, method 600 includes determining a presence of a leak in the heat transfer tube in response to a decline in pressure in the heat transfer tube during the leak monitoring period.

[0107] Referring to FIG. 33, an exemplary method 650 for redressing an economizer (e.g., economizer 400) of a waste heat recovery system (e.g., waste heat recovery system 10) is shown. Initially, at block 652, method 650 includes fluidically disconnecting a pair of ends (e.g., ends 486 and 516) of a heat transfer tube (e.g., heat transfer tubes 480 and 510) of a selected tube cartridge (e.g., tube cartridges 470 and 500) of a plurality of tube cartridges of the economizer from an inlet fluid conduit (e.g., inlet fluid conduit 430) and a discharge fluid conduit (e.g., discharge fluid conduit 450) of the economizer.

[0108] At block 654, method 650 includes individually extracting the selected tube cartridge from an interior of an outer housing (e.g., interior 403 of outer housing 402) of the economizer. At block 656, method 650 includes individually inserting a replacement tube cartridge into the interior of the outer housing of the economizer. At block 658, method 650 includes fluidically connecting a pair of ends (e.g., ends 486 and 516) of a heat transfer tube of the replacement tube cartridge to the inlet fluid conduit and the discharge fluid conduit.

[0109] Referring to FIG. 34, an exemplary method 700 for redressing an economizer (e.g., economizer 20 of FIG. 1, economizer 100 shown in FIGS. 2-4, economizer 200 of FIG. 16, or economizer 300 of FIG. 18) of a waste heat recovery system (e.g., waste heat recovery system 10 shown in FIG. 1) is shown. Initially, at block 702, method 700 includes extracting a heat transfer tube (e.g., heat transfer tube 140) from an interior of an outer housing (e.g., outer housing 102 of economizer 100, outer housing 220 of economizers 200 and 300) of the economizer.

[0110] At block 704, method 700 includes disconnecting a pair of ends (e.g., terminal ends 143-1 and 143-2 of a heat transfer tube 140) of the heat transfer tube to separate the heat transfer tube from an inlet manifold (e.g., inlet manifold 170) and a discharge manifold (e.g., discharge manifold 190) of the economizer. At block 706, method 700 includes sliding the pair of ends of the heat transfer tube through a pair of seal3604-00502assemblies (e.g., seal assemblies 150 of economizers 100, 200, and 300) of the economizer and a pair of tube openings formed in a cover (e.g., cover 106 of economizer 100 or cover 230 of economizers 200 and 300) that forms part of the outer housing to release the heat transfer tube from the outer housing.[oom] An embodiment of an economizer for a waste heat recovery system comprises an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and defining an interior extending between the inlet and the outlet, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell, an inlet fluid conduit defining a tubeside inlet of the economizer, a discharge fluid conduit defining a tubeside discharge of the economizer, and a plurality of tubes received in the interior of the outer housing and connected fluidically in parallel between the inlet fluid conduit and the discharge fluid conduit, wherein at least one of the plurality of tubes comprises a plurality of fluid nozzles in fluid communication with the tube and spaced longitudinally along the tube for emitting a plurality of fluid jets extending along jet axes directed through the interior of the outer housing and orthogonally against other tubes of the plurality of tubes. In some embodiments, the jet axes of the plurality of fluid nozzles each extend parallel one another. In some embodiments, at least some of the plurality of fluid nozzles are positioned along each lateral side of the tube for directing the fluid jets in opposing orthogonal directions. In certain embodiments, the tube comprises a plurality of parallel extending linear tubes and a plurality of elbows interconnecting the plurality of linear tubes. In certain embodiments, the plurality of fluid nozzles are spaced along the linear tubes of the tube. In some embodiments, each of the fluid nozzles has a central passage including a reduced-diameter section for accelerating a fluid flow therethrough.

[0112] An embodiment of an economizer for a waste heat recovery system comprises an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and defining an interior extending between the inlet and the outlet, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell, an inlet fluid conduit defining a tubeside inlet of the economizer, a discharge fluid conduit defining a tubeside discharge of the economizer, a plurality of heat transfer tubes connected fluidically in parallel between the inlet fluid conduit and the discharge fluid conduit, and a plurality of valves fluidically connected in parallel between opposing ends of the plurality of heat transfer tubes and the inlet fluid3604-00502conduit and the discharge fluid conduit, wherein the plurality of valves have an open state providing fluid communication between the plurality of heat transfer tubes and both the inlet fluid conduit and the discharge fluid conduit, and closed states fluidically isolating the plurality of heat transfer tubes from both the inlet fluid conduit and the discharge fluid conduit, and a plurality of test ports configured to fluidically connect to the plurality of heat transfer tubes for applying a test pressure to the plurality of heat transfer tubes when the plurality of valves are in the closed state. In some embodiments, each of the plurality of valves is manually actuatable between the open state and the closed state. In some embodiments, the plurality of test ports are fluidically connectable to the plurality of heat transfer tubes to individually apply the test pressure to a selected heat transfer tube of the plurality of heat transfer tubes. In certain embodiments, the plurality of test ports are formed in valve bodies of the plurality of valves. In certain embodiments, the test pressure applied to the plurality of heat transfer tubes is fluidically isolated from both the inlet fluid conduit and the discharge fluid conduit. In some embodiments, the economizer comprises a plurality of releasable connectors configured to releasably connect the plurality of heat transfer tubes to the plurality of valves. In some embodiments, each of the plurality of releasable connectors comprises a threaded connector.

[0113] An embodiment of a method for leak testing an economizer of a waste heat recovery system comprises (a) fluidically isolating a selected tube cartridge of a plurality of tube cartridges of the economizer from both an inlet fluid conduit defining a tubeside inlet of the economizer and a discharge fluid conduit defining a tubeside discharge of the economizer, (b) pressurizing a heat transfer tube of the selected tube cartridge to a test pressure, (c) ceasing further pressurization of the heat transfer tube once the test pressure in the heat transfer tube has been achieved to initiate a leak monitoring period, and (d) determining a presence of a leak in the heat transfer tube in response to a decline in pressure in the heat transfer tube during the leak monitoring period. In certain embodiments, (a) comprises shifting one or more valves fluidically connected o the selected tube cartridge from an open state to a closed state. In certain embodiments, (b) comprises fluidically connecting a test port in fluid communication with the heat transfer tube of the selected tube cartridge to a test pressure source. In some embodiments, the test pressure source is separate from an inlet fluid conduit of the economizer. In some embodiments, (d) comprises monitoring a fluid pressure of the heat transfer tube during the leak monitoring period.3604-00502

[0114] While exemplary embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.

[0115] Each and every claim is incorporated into the specification as an aspect of the present disclosure. Thus, the claims are a further description and are an addition to the aspects of the present invention. The discussion of a reference herein is not an admission that it is prior art to the presently disclosed subject matter, especially any reference that may have a publication date after the priority date of this application. The disclosures of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent that they provide exemplary, procedural or other details supplementary to those set forth herein.

Claims

3604-00502CLAIMSWhat is claimed is:

1. An economizer for a waste heat recovery system, the economizer comprising:an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and a plurality of slots formed in an interior of the outer housing, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell;an inlet fluid conduit defining a tubeside inlet of the economizer;a discharge fluid conduit defining a tubeside discharge of the economizer; and a plurality of tube cartridges individually and separately receivable in the plurality of slots formed in the interior of the outer housing, wherein at least some of the plurality of tube cartridges comprises:a tube chassis releasably connectable to the outer housing to lock the tube cartridge to the outer housing; anda heat transfer tube fluidically connectable to the inlet fluid conduit and the discharge fluid conduit when the tube cartridge is received in the interior of the outer housing.

2. The economizer of claim 1, wherein the plurality of slots are defined by a plurality of elongate rails positioned in the interior of the outer housing that physically divide the plurality of slots from one another.

3. The economizer of claim 1 , further comprising a plurality of fasteners configured to releasably couple the tube chassis of the plurality of tube cartridges to the outer housing.

4. The economizer of claim 1, wherein the heat transfer tube of at least some of the plurality of tube cartridges comprises a plurality of parallel extending linear tubes and a plurality of elbows interconnecting the plurality of linear tubes.

5. The economizer of claim 1, further comprising a plurality of releasable connectors configured to releasably couple opposing ends of the heat transfer tube of3604-00502at least some of the plurality of tube cartridges to the inlet fluid conduit and the discharge fluid conduit.

6. The economizer of claim 5, wherein the plurality of releasable connectors each comprises a threaded connector.

7. The economizer of claim 1, further comprising a plurality of valves fluidically connectable in parallel between the plurality of tube cartridges and both the inlet fluid conduit and the discharge fluid conduit for individually fluidically isolating selected tube cartridges of the plurality of tube cartridges from both the inlet fluid conduit and the discharge fluid conduit.

8. The economizer of claim 1, wherein at least one of the tube cartridges comprises a tube and a plurality of fluid nozzles in fluid communication with the tube of the tube cartridge and spaced longitudinally along the tube for emitting a plurality of fluid jets extending along jet axes directed orthogonally against the heat transfer tubes of other tube cartridges of the plurality of tube cartridges.

9. An economizer for a waste heat recovery system, the economizer comprising:an outer housing comprising a cover and a shell having a shellside inlet, a shellside outlet, and defining an interior extending between the inlet and the outlet, wherein the cover is configured to enclose the interior of the shell in response to releasably coupling the cover to the shell;an inlet fluid conduit defining a tubeside inlet of the economizer;a discharge fluid conduit defining a tubeside discharge of the economizer; a plurality of heat transfer tubes connected fluidically in parallel between the inlet fluid conduit and the discharge fluid conduit, wherein the plurality of heat transfer tubes slidably extend through a plurality of tube openings formed in the cover; and a plurality of seal assemblies sealing interfaces formed between the plurality of heat transfer tubes and the plurality of tube openings of the cover through the plurality of heat transfer tubes extend.3604-0050210. The economizer of claim 9, wherein each of the plurality of seal assemblies are coupled to the cover with the plurality of heat transfer tubes extending slidably therethrough.

11. The economizer of claim 10, wherein:each of the plurality of seal assemblies comprises an annular collar coupled to the cover, an annular seal received within the collar, and an annular connector releasably connectable to the collar; andthe connector is insertable into the collar to longitudinally compress the seal assembly and increase a sealing force applied by the annular seal to both the collar and a heat transfer tube of the plurality of heat transfer tube extending through the seal assembly.

12. The economizer of claim 11, wherein the connector of each of the plurality of seal assemblies is threadable into the collar of the seal assembly.

13. The economizer of claim 11, wherein the collar of each of the plurality of seal assemblies comprises a threaded inner surface, the connector comprises a threaded outer surface threadably engaged with the threaded inner surface of the collar.

14. The economizer of claim 9, wherein each of the plurality of heat transfer tubes comprises a plurality of parallel extending linear tubes and a plurality of elbows interconnecting the plurality of linear tubes.

15. The economizer of claim 9, wherein the plurality of heat transfer tubes are permitted to slide through the plurality of tube openings of the cover in response to disconnecting the plurality of heat transfer tubes from the inlet fluid conduit and the discharge fluid conduit.

16. The economizer of claim 9, further comprising a plurality of clamping assemblies for releasably connecting the shell to the cover, wherein each of the plurality of clamping assemblies comprises a first clamping member defining a first clamping surface, a second clamping member defining a second clamping surface,3604-00502and a fastener for adjusting a width of a clamping opening formed between the first clamping surface and the second clamping surface.

17. The economizer of claim 16, wherein the annular seal of each of the plurality of seal assemblies comprises at least one of a packing gland or an O-ring.

18. A method for redressing an economizer of a waste heat recovery system, the method comprising:(a) fluidically disconnecting a pair of ends of a heat transfer tube of a selected tube cartridge of a plurality of tube cartridges of the economizer from an inlet fluid conduit and a discharge fluid conduit of the economizer;(b) individually extracting the selected tube cartridge from an interior of an outer housing of the economizer;(c) individually inserting a replacement tube cartridge into the interior of the outer housing of the economizer; and(d) fluidically connecting a pair of ends of a heat transfer tube of the replacement tube cartridge to the inlet fluid conduit and the discharge fluid conduit.

19. The method of claim 18, wherein (a) comprises disconnecting releasable connectors from the pair of ends of the heat transfer tube of the selected tube cartridge.

20. The method of claim 19, wherein the releasable connectors comprise threaded connectors.

21. The method of claim 18, wherein (b) comprises sliding the selected tube cartridge from a corresponding slot formed in the interior of the outer housing.

22. The method of claim 21, wherein the slot is formed by a plurality of elongate dividers positioned in the interior of the outer housing.

23. The method of claim 22, wherein (b) comprises sliding the pair of ends of the heat transfer tube through a pair of seal assemblies connected to the outer housing.3604-0050224. A method for redressing an economizer of a waste heat recovery system, the method comprising:(a) disconnecting a pair of ends of the heat transfer tube to separate the heat transfer tube from an inlet fluid conduit and a discharge fluid conduit of the economizer;(b) extracting a heat transfer tube of the economizer from an interior of an outer housing of the economizer; and(c) sliding a pair of ends of the heat transfer tube through a pair of seal assemblies of the economizer and a pair of tube openings formed in a cover that forms part of the outer housing to release the heat transfer tube from the outer housing.

25. The method of claim 24, wherein (b) comprises cutting the pair of ends of the heat transfer tube.

26. The method of claim 24, wherein:(b) comprises disconnecting the heat transfer tube from the tube bundle; and the method further comprises:(d) sealing each of the pair of ends and the pair of seal assemblies; and (e) inserting a tube bundle comprising the heat transfer tube following (d) into the interior of the outer housing of the economizer.

27. The method of claim 26, wherein (e) comprises vertically lowering the tube bundle into the interior of the outer housing.

28. The method of claim 26, further comprising:(f) reconnecting the heat transfer tube to the tube bundle following (c) but prior to (e).

29. The method of claim 24, wherein (d) comprises welding an endcap onto each of the pair of ends.

30. The method of claim 24, wherein (d) comprises threadably inserting an enclosed plug into each of the pair of seal assemblies.

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