Patent Description:
Conventional methods of assembling and installing a coil wound heat exchanger ("CWHE") are time consuming and lead to increased manufacturing duration. Under a typical method, the shell supported by set of shop saddles while a wound bundle is telescoped into the pressure containing shell ("shell"). After the wound bundle is telescoped into the shell, the CWHE is lifted onto a transport vehicle, where it is strapped to a set of transport saddles and transported in a horizontal position. When the CWHE arrives at a plant site, it is erected into a vertical position and a support frame is built around it. The support frame includes structural elements that are designed to provide vertical support for the CWHE, as well as to account for wind and seismic loads.

Conventional CWHE assembly methods require that piping connections, electrical connections, instrumentation, walking platforms, etc. be installed after the CWHE has been erected at the plant site and at least some of the support frame has been built. This results in relatively long construction timelines and means that the installation of these items must take place outdoors at the plant site. In addition, three different sets of structures are used to support the CWHE during the various stages of construction and lifting equipment must be directly attached to the shell when the shell is lifted onto the transport vehicle and when it is erected at the plant site. <CIT> discloses a large air distillation column and corresponding cold box modules.

There is a need for an improved method of assembling and installing a CHWE.

Improved methods are provided herein for assembling a heat exchanger and cryogenic equipment, as well as an improved module frame and structure for connecting the heat exchanger to the module frame.

According to a first aspect of the present invention, there is provided a method comprising:.

According to a second aspect of the present invention, there is provided a heat exchange module comprising:.

Preferably, each of the first saddle joints is adapted to prevent movement of the first saddle relative to the module frame in directions that are not parallel to the shell longitudinal axis.

In a preferred embodiment, the heat exchange module, further comprises a second saddle that is rigidly attached to the shell and is connected to the module frame by a plurality of second saddle joints, each of the plurality of second saddle joints being adapted to allow for thermal expansion and contraction of the shell by enabling the second saddle to move relative to the module frame in a direction that is parallel to the shell longitudinal axis of the shell.

Preferably, each of the second saddle joints is adapted to prevent movement of the second saddle relative to the module frame in directions that are not parallel to the shell longitudinal axis.

Preferably, each of the plurality of first saddle joints comprises a plurality of bolts extending through a plurality of plates, at least one of the plurality of plates having a plurality of slots that each engage at least one bolt.

Preferably, the first saddle is positioned between the lug and the top end and the bottom end of the shell.

Preferably, the second saddle is positioned between the lug and the other of the top end and the bottom end of the shell.

Preferably, the lug is positioned within <NUM>% of a longitudinal center of mass of the shell:.

Preferably, the first saddle is positioned within <NUM>% of a midpoint between the lug and one of the top and bottom end of the shell.

Preferably, the second saddle is positioned within <NUM>% of a midpoint between the lug and the other of the top and bottom end of the shell.

Preferably, the first saddle further comprises a first contoured plate at a first interface with the shell, the first contoured plate being complimentary in shape to the shell along the first interface.

Preferably, the first interface comprises at least one third of a circumference of the shell.

Preferably, the second saddle further comprises a second contoured plate at a second interface with the shell, the second contoured plate being complimentary in shape to the shell along the second interface.

Preferably, the second interface comprises at least one third of a circumference of the shell.

Preferably, the first saddle further comprises a plurality of ribs, each of the plurality of ribs being oriented perpendicular to the plurality of first saddle joints and extending linearly between the heat exchange module and the plurality of first saddle joints.

Preferably, the second saddle further comprises a plurality of ribs, each of the plurality of ribs being oriented perpendicular to the plurality of second saddle joints and extending linearly between the heat exchange module and the plurality of second saddle joints.

Preferably, the first saddle, the second saddle, and the lug each encircle the shell.

In a preferred embodiment, the heat exchange module further comprises at least one walkway comprising a walking platform and a railing, each of the at least one walkway being rigidly attached to the module frame and having no attachment points with the shell.

According to a third aspect of the present invention, there is provided a plant for liquefying a hydrocarbon feed gas, the plant comprising:.

Preferably, the at least one heat exchange module comprises a first heat exchange module and a second heat exchange module, a module frame of the first heat exchange module being affixed to and vertically aligned with a module frame of the second heat exchange module.

Preferably, the shell of the first heat exchange module is in fluid flow communication with the shell of the second heat exchange module.

Preferably, the hydrocarbon feed gas consists of natural gas.

Embodiments are described herein making reference to the appended drawings.

In the following, details are set forth to provide a more thorough explanation of the exemplary embodiments. However, it will be apparent to those skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form or in a schematic view rather than in detail in order to avoid obscuring the embodiments. In addition, features of the different embodiments described hereinafter may be combined with each other, unless specifically noted otherwise.

Further, equivalent or like elements or elements with equivalent or like functionality are denoted in the following description with equivalent or like reference numerals. As the same or functionally equivalent elements are given the same reference numbers in the figures, a repeated description for elements provided with the same reference numbers may be omitted. Hence, descriptions provided for elements having the same or like reference numbers are mutually exchangeable.

The following detailed description is not to be taken in a limiting sense. In this regard, directional terminology, such as "top", "bottom", "lower," "upper," "below", "above", "front", "behind", "back", "leading", "trailing", "horizontal," "vertical," etc., may be used with reference to the orientation of the figures being described. Terms including "inwardly" versus "outwardly," "longitudinal" versus "lateral" and the like are to be interpreted relative to one another or relative to an axis of elongation, or an axis or center of rotation, as appropriate. Because parts of embodiments may be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims.

Terms concerning attachments, coupling and the like, such as "connected" and "interconnected," refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both moveable or rigid attachments or relationships, unless expressly described otherwise, and includes terms such as "directly" coupled, secured, etc. The term "operatively coupled" is such an attachment, coupling, or connection that allows the pertinent structures to operate as intended by virtue of that relationship.

The term "substantially" may be used herein to account for manufacturing tolerances (e.g., within <NUM>%) that are deemed acceptable in the industry without departing from the aspects of the embodiments described herein. In the context of an orientation, the term "substantially" means within <NUM> degrees of that orientation. For example, "substantially vertical" means within <NUM> degrees in either direction of vertical.

As used herein, the term "orientation", in reference to an orientation of a structure, is intended to mean that the orientation of the structure is defined by the structure's longest dimension.

The term "fluid flow communication," as used in the specification and claims, refers to the nature of connectivity between two or more components that enables liquids, vapors, and/or two-phase mixtures to be transported between the components in a controlled fashion (i.e., without leakage) either directly or indirectly. Coupling two or more components such that they are in fluid flow communication with each other can involve any suitable method known in the art, such as with the use of welds, flanged conduits, gaskets, and bolts. Two or more components may also be coupled together via other components of the system that may separate them, for example, valves, gates, or other devices that may selectively restrict or direct fluid flow.

The term "conduit," as used in the specification and claims, refers to one or more structures through which fluids can be transported between two or more components of a system. For example, conduits can include pipes, ducts, passageways, and combinations thereof that transport liquids, vapors, and/or gases.

The term "natural gas", as used in the specification and claims, means a hydrocarbon gas mixture consisting primarily of methane.

The term "mixed refrigerant" (abbreviated as "MR"), as used in the specification and claims, means a fluid comprising at least two hydrocarbons and for which hydrocarbons comprise at least <NUM>% of the overall composition of the refrigerant.

The terms "bundle" and "tube bundle" are used interchangeably within this application and are intended to be synonymous.

The term "compression circuit" is used herein to refer to the components and conduits in fluid communication with one another and arranged in series (hereinafter "series fluid flow communication"), beginning upstream from the first compressor or compression stage and ending downstream from the last compressor or compressor stage. The term "compression sequence" is intended to refer to the steps performed by the components and conduits that comprise the associated compression circuit.

As used herein, the term "vertical orientation" is intended to mean that a structure's longest dimension is oriented vertically.

As used herein, the term "horizontal orientation" is intended to mean that a structure's longest dimension is oriented horizontally.

As used herein, the term "rigidly attached" is intended to mean that a structure is mechanically coupled to the other structure in a way that prevents any motion between the two structures, such as bolting or welding. Unless otherwise specified, a first element is considered to be "rigidly attached" to a second element even if the attachment is indirect (i.e., additional elements are located between the first and second elements).

As used herein, the term "ambient temperature" refers to the air temperature of the environment surrounding the equipment.

<FIG> and <FIG> illustrate an exemplary method of assembling a single shell heat exchange module <NUM> (<FIG>). The heat exchange module <NUM> comprises a coil wound heat exchanger (CWHE). CWHEs are often employed for natural gas liquefaction. CWHEs typically contain helically wound tube bundles housed within an aluminum or stainless steel shell that forms a pressure vessel. For liquid natural gas (LNG) service, a CWHE may include multiple tube bundles, each having several tube circuits. Cooling might be provided using any one of a variety of refrigerants, for example, a mixed refrigerant (MR) stream having a mixture of nitrogen, methane, ethane/ethylene, propane, butanes and pentanes is a commonly used refrigerant for many base-load LNG plants. The refrigeration cycle employed for natural gas liquefaction might be a cascade cycle, single mixed refrigerant cycle (SMR), propane-precooled mixed refrigerant cycle (C3MR), dual mixed refrigerant cycle (DMR), nitrogen or methane expander cycles, or any other appropriate refrigeration process. The composition of the MR stream is optimized for the feed gas composition and operating conditions. Located at the top of each tube bundle within the shell is a distributor assembly that distributes the refrigerant over the tube bundle in the space between the shell and the mandrel, which provides refrigeration for the fluids flowing through the tube bundles. An example of a distributor assembly is disclosed in <CIT>.

<FIG> illustrate a first exemplary method of assembling a heat exchange module <NUM> comprising a CWHE having two coil wound mandrels <NUM>, <NUM>. In order to form each coil wound mandrel, <NUM>, <NUM>, tubing <NUM> is spirally wound about a mandrel <NUM>. In most applications, multiple circuits of tubing will be wound about the mandrel <NUM>. Each coil wound mandrel <NUM> has inlets located at or proximate to a first end 110a of the mandrel <NUM> and outlets located at or proximate to a second end 110b of the mandrel <NUM>.

As shown in <FIG>, two saddles 136a, 136b are affixed to a first (lower) portion <NUM> of the pressure vessel shell ("shell"), then the first coil wound mandrels <NUM> is telescoped (i.e., inserted) into the first portion <NUM> of the shell through an open top end of the first portion <NUM> along a longitudinal axis L of the lower portion <NUM>. Similarly, as shown in <FIG>, two saddles 136c and 136d affixed to a second (upper) portion <NUM> of the shell, then the second coil wound mandrel <NUM> is telescoped into the second portion <NUM>. After both coil wound mandrels <NUM>, <NUM> have been inserted into the first and second portions <NUM>, <NUM> of the shell, respectively, the first and second portions <NUM>, <NUM> are joined to form the pressure vessel shell <NUM> (See <FIG>). After the shell <NUM> is fully formed and closed, it is transported to a plant site in a horizontal orientation (the orientation shown in <FIG>). Upon arrival at the plant site and as shown in <FIG>, the heat exchange module <NUM> is erected into a vertical orientation and installation is completed.

The module frame structure that supports the heat exchange module <NUM> at the plant site is not shown. The module frame could be assembled and affixed to the first and second portions <NUM>, <NUM> of the shell <NUM> prior to telescoping of the coil wound mandrels <NUM>, <NUM>, or the module frame could be assembled and affixed to shell <NUM> after it is erected at the plant site.

A key improvement of the assembly method described in connection with the heat exchange module <NUM> shown in <FIG> is that the saddles 136a-136d are attached each portion <NUM>, <NUM> of the shell <NUM> prior to telescoping the coil wound mandrel <NUM>, <NUM> into each portion, that those saddles 136a-136d are never removed from the shell <NUM>, and that the saddles 136a-136d are attached to the module frame when it is installed. In other words, the saddles 136a-d that are used to support the portions <NUM>, <NUM> of the shell <NUM> during telescoping remain part of the structural support of the CWHE throughout the construction and installation process, as well as when the CWHE is operated. Accordingly, the saddles 136a-136d are adapted to provide support for the CWHE during transport (when it is in a horizonal orientation) and after the CWHE has been erected and installed at the plant site (in which the CWHE is in a vertical orientation). This is in contrast to convention assembly methods, in which three different set of saddles are used in the telescoping, transportation, and final installation stages.

As shown in <FIG> & <FIG>, the saddles 136a are configured to support both horizontal and vertical loads of the CWHE shell <NUM>. To this end, each of saddles 136a-136b includes a frame portion (see frame portions 137a, 137b) that is framed around (i.e., fully encircles) the shell <NUM> and a base portion (see base portions 138a, 138b) that makes contact with a load bearing surface (e.g., a platform, ground, and/or a module frame) and supports horizontal and vertical loads when the shell <NUM> is in a horizontal orientation.

Using a single set of saddles throughout the assembly, transportation, and site installation stages provides several advantages. For example, insulation can be installed on shell <NUM> prior to transportation of the CWHE to the plant site because it won't be disturbed by removal and installation of different saddles and additional connection to the module frame.

<FIG> illustrate the exemplary assembly method on a heat exchange module <NUM> having a different configuration. This method is very similar to the method described in <FIG>, the primary difference being that, in this method, the CWHE has two separate shells (pressure vessels) <NUM>, <NUM>, each containing one coil wound mandrel <NUM>. In this method, the coil wound mandrels are formed as shown in <FIG>. As shown in <FIG>, two saddles 236a, 236b are affixed to the first shell <NUM>, then the first coil wound mandrel <NUM>,<NUM> is telescoped into the first shell <NUM> through an open top end/face. When telescoping is complete, the top end of the shell <NUM> is sealed by, as shown in <FIG>. The process is repeated for the second shell <NUM>. The assembled shells <NUM>, <NUM> are transported to the plant site in the same manner as the shell <NUM> and as shown in <FIG>. Upon arrival at the plant site and as shown in <FIG>, each of the shells <NUM>, <NUM> are erected into a vertical orientation. Two saddles 236c, 236d are affixed to the second shell <NUM>.

In this exemplary method, the module frame structure that supports the CWHE shells <NUM>, <NUM> at the plant site is not shown. The module frame could be assembled and affixed to the shells <NUM>, <NUM> prior to telescoping of the coil wound mandrels or the module frame could be assembled and affixed to shells <NUM>, <NUM> after the heat exchange module <NUM> is erected at the plant site. Referring to <FIG>, because the CWHE comprises two shells <NUM>, <NUM>, the second shell <NUM> is positioned atop the first shell <NUM>. Accordingly, if the module frame for each shell <NUM>, <NUM> is installed prior to transport of the shells <NUM>, <NUM> to the plant site, the module frame of the second shell <NUM> is preferably attached to the top of the module frame for the first shell <NUM>. Once the shells <NUM>, <NUM> are installed at the plant site, external piping 254a-b that interconnects the shells <NUM>, <NUM> is installed.

<FIG> illustrate another exemplary method of assembling a heat exchange module <NUM> having a multiple shell CWHE. The steps of the assembly process are nearly identical to those of the method shown in <FIG>, except the module frames 360a-b are constructed and connected to the saddles 338a-b prior to telescoping the coil wound mandrels <NUM>, <NUM> into the respective shells <NUM>, <NUM> (see <FIG>). Constructing the module frame 360a and connecting the saddles 338a-b to the module frame 360a prior to telescoping enables external piping 354a-c, piping supports, valves, steps, ladders, standing platforms, and insulation to be installed prior to transportation of the shells <NUM>, <NUM> to the plant site because the module frame 360a protects the shell <NUM> and provides attachment points for the elements being installed. In this method, the module frame 360a, the fully formed shell <NUM>, and the saddles 336a-b form a heat exchange module 366a. A second heat exchange module 366b is formed using the same steps as the heat exchange module 366a.

Installation at the plant site is further simplified with this method. The first heat exchange module 366a is erected into a vertical position and the first module frame is affixed to a platform <NUM> at the plant site (typically a concrete pad or footer). Then the second heat exchange module 366b is erected into a vertical position and the second module frame 366b is mounted to top of the first module frame 366a. Once the shells <NUM>, <NUM> are installed at the plant site, external piping 354d-e and electrical connections (not shown) that interconnect the shells <NUM>, <NUM> are installed.

<FIG> illustrates another exemplary method for forming a heat exchange module <NUM>. The multiple shell heat exchange module <NUM> includes two pressure vessels (shells) <NUM>, <NUM>, a first module frame 360a and a second module frame 360b are manufactured. Each module frame <NUM> includes a plurality of beams <NUM> and trusses <NUM> to increase the overall strength of the structure. The plurality of beams <NUM> that define a frame volume of the module frame <NUM>. Trusses <NUM>, if included, may also define the frame volume since they do not extend beyond the frame volume defined by the beams <NUM>. Thus, the framing of each module frame <NUM> forms a rectangular frame with a cavity (i.e., frame volume) configured to receive a corresponding pressure vessel. In other words, each module frame <NUM> is serves as an exoskeleton for its pressure vessel. Multiple module frames and support modules may be manufactured in parallel for each pressure vessel.

As will be described below, the first and second module frames 360a, 360b are configured to be rigidly connected to a corresponding one of the first and second shells <NUM>, <NUM>, thereby forming a first heat exchange module. In this arrangement, the plurality of beams <NUM> are sized and arranged such that no part of the pressure vessel shell extends outwardly beyond the frame volume. In some arrangements, a pressure vessel, including external piping and wiring is confined within the frame volume, while in other arrangements, some eternal piping and wiring may extend beyond the frame volume. Thus, the module frame <NUM> itself is a frame enclosure configured to enclose a pressure vessel therein, such that the module frame <NUM> defines an outermost boundary in each dimension of the corresponding pressure vessel shell. In other words, at the very least, the corresponding pressure vessel shell does not extend beyond the module frame <NUM> in any dimension. In alternative arrangements, it may be desirable to have the shell protrude from the top of the module frame in order to facilitate connections to other elements of the plant.

In addition, each of the first and second shells <NUM>, <NUM> is suspended within the frame volume of its corresponding module frame, such that the pressure vessel is supported by the module frame both when in a horizonal orientation and in a vertical orientation. In addition, each saddle <NUM> is rigidly attached to its corresponding module frame <NUM> (see e.g., <FIG>). Also, when the wound bundle <NUM> is being telescoped into the shell <NUM>, it may be desirable to pull the wound bundle <NUM> through the shell <NUM> using cables that extend through a opening at the bottom end of the shell <NUM>.

An exemplary embodiment in accordance with the present invention is shown in <FIG>. In this embodiment, exemplary structures used to execute the assembly methods disclosed in <FIG> are disclosed in greater detail. <FIG>show a fully assembled CWHE, which consists of two heat exchange modules 466a, 466b. Each heat exchange module 466a, 466b comprises a shell <NUM>, <NUM>, a module frame 460a, 460b, two saddles 436a-d, and a lug 441a, 441b. As will be described herein, the saddles 436a-d, and the lug 441a, 441b connect the shells <NUM>, <NUM> to their respective module frames 466a, 466b and are adapted to accommodate for multiple types of loads throughout the assembly process and during operation. The structure of the second heat exchange module 466b will be described in detail herein. The described structure is nearly identical in nature in the first heat exchange module 466a, understanding that some dimensions may be different due primarily to the fact that the shells <NUM>, <NUM> have different dimensions.

One of the saddles 436d is shown in <FIG>. It should be understood that the other saddle 436c of the upper heat exchange module 466b and the saddles 436a-b of the lower heat exchange module 466a have the same structural elements and only differ in dimension/proportions and location. For example, the saddles 436a-b will have larger dimensions due to the larger circumference of the shell <NUM>. The saddle 436d includes a frame portion <NUM> which encircles the shell <NUM>. The saddle 436d further includes sliding joint plates 438a-b which engage sliding joints 467a-d and connect the saddle 436d with a cross member <NUM> of the module frame 466d. Optionally, a base plate <NUM> can be provided at the connection to the cross member <NUM> to provide additional structural strength.

The saddle 436d further includes a contoured plate <NUM>, which is arcuate and complimentary in shape to the outer surface of the shell <NUM> along an interface. The interface preferably overlaps at least one quarter and, more preferably, at least one third of the circumference of the shell <NUM>. The saddle 436d further includes a plurality of ribs <NUM>, which extend linearly from the base plate <NUM>, are welded to the sliding joint plates 443a-b, then continue to the contour plate <NUM> in a direction that is perpendicular to the base plate <NUM>. The saddle 436d is rigidly affixed to the shell <NUM>, either with welds and or fasteners.

Each of the sliding joints 467a-d includes a plurality of bolts <NUM> (in this embodiment, two bolts per sliding joint), which extend through slots <NUM> formed in the sliding joint plates 445a-b. Each slot <NUM> has a length that is significantly greater than the diameter of the bolt <NUM> that engages that slot <NUM>. The length of the slot <NUM> is preferably at least <NUM> times (more preferably at least twice) the diameter of the bolt <NUM>. Alternatively, an elongated slot <NUM> could be formed in one of the sliding joint plates 445a-b and holes that are much closer to the diameter of the bolts <NUM> could be provided. The joint plates 445a-b, slots <NUM>, and bolts <NUM> combine to define a shear block. The configuration of the sliding joints 436a-d enables the saddle 436d to move relative to the module frame 466b in a direction parallel to the length of the shell <NUM>, but prevents any other substantial movement of the saddle 436d relative to the module frame 466b. The movement allowed by the slots <NUM> is preferably sufficient to accommodate thermal contraction and expansion of the shell <NUM> that is expected to occur when the shell <NUM> is transition to operating temperature.

<FIG> show the structure of the lug 441b in detail. The lug 441b comprises cross-members 442a-d and beams 443a-d that "box" in the shell <NUM>. The beams 443a-d are each welded to two cross-members 442a-d and are either welded or bolded to the shell <NUM>. The cross-members 442a-d are also preferably welded or bolted to the module frame. This structure rigidly attaches the lug 441b to both the shell <NUM> and the module frame 460b.

The lug 441b and the two saddles 436c-d attach the shell <NUM> to the module frame 460b and cooperate to accommodate multiple different types of loads during assembly, transportation, and operation of the heat exchange module <NUM>. When the shell <NUM> is being assembled and transported (see shell <NUM>, <FIG>), the saddles 436c-d provide the primary support and stability for the shell <NUM>. When the shell <NUM> is installed in a vertical orientation at the plant site (see <FIG>), the lug 441b provides the primary vertical support. The saddles 436c-d cooperate with the lug 441b to provide support against wind and seismic loads. The sliding joints 467a-d and the position of each saddle 436c-d allows for thermal expansion of the shell <NUM>.

The preferred location of the lug 441b and the saddles 436c-d will depend upon a number of factors, including the geometry of the shell <NUM>, its position in the module frame 460b, and the location of piping protrusions on the surface of the shell <NUM>. In general, it is preferable that the lug 441b be located within <NUM>% (more preferably within <NUM>%) of the center of mass of the shell <NUM>. The lower saddle 436c is located between the lug 441b and the bottom end of the shell <NUM> and is preferably within <NUM>% (more preferably within <NUM>%) of the midpoint between the location of the lug 441b and the bottom end of the shell <NUM>. The upper saddle 436c is located between the lug 441b and the top end of the shell <NUM> and is preferably within <NUM>% (more preferably within <NUM>%) of the midpoint between the location of the lug 441b and the top end of the shell <NUM>. By way of example, if the shell <NUM> has a length of <NUM> meters and a center of mass at its midpoint, the lug 441b would be preferably located within <NUM> meters, and more preferably within <NUM> meters, of the midpoint.

As noted in previous embodiments, each shell <NUM>, <NUM> is contained within a perimeter defined by the cross members 462a-d (see <FIG>) of the module frame 466a-b. This provides protection for the shells <NUM>,<NUM> during construction and transport. It should be understood that a shell <NUM>, <NUM> may extend beyond an end of the frame module 466a-b, such at the top of shell <NUM>, which extends beyond the upper end of its frame module 466b. This most common for a shell of a single-shell heat exchanger or the uppermost shell of a multiple-shell heat exchanger.

The methods described herein allow for all internal piping and almost all external piping to the shells to be completed prior to the completion of the coil wound exchanger bundle. In addition, valves and instruments can be installed and insulated before the long lead bundles are telescoped into the shells. Additionally, this method can eliminate the need for temporary shipping saddles. In addition, the use of multiple pressure vessels including any combination thereof within the module frames can be accommodated. Furthermore, once at the operation site the final piping connections are made and the exchanger modules can be made operational.

As noted above, the heat exchange modules <NUM>, <NUM>, <NUM>, <NUM> disclosed herein are most commonly used as part of a natural gas liquefaction plant (system). An exemplary natural gas liquefaction system <NUM> is shown in <FIG>. Referring to <FIG>, a feed stream <NUM>, which is preferably natural gas, is cleaned and dried by known methods in a pre-treatment section <NUM> to remove water, acid gases such as CO2 and H2S, and other contaminants such as mercury, resulting in a pre-treated feed stream <NUM>. The pre-treated feed stream <NUM>, which is essentially water free, is pre-cooled in a pre-cooling system <NUM> to produce a pre-cooled natural gas stream <NUM> and further cooled, liquefied, and/or sub-cooled in a CWHE <NUM> (which could be heat exchange module <NUM> or <NUM>) to produce an LNG stream <NUM>. The LNG stream <NUM> is typically let down in pressure by passing it through a valve or a turbine (not shown) and is then sent to LNG storage tank <NUM>. Any flash vapor produced during the pressure letdown and/or boil-off in the tank is represented by stream <NUM>, which may be used as fuel in the plant, recycled to feed, or vented.

The pre-treated feed stream <NUM> is pre-cooled to a temperature below <NUM> degrees Celsius, preferably below about <NUM> degrees Celsius, and more preferably about -<NUM> degrees Celsius. The pre-cooled natural gas stream <NUM> is liquefied to a temperature between about -<NUM> degrees Celsius and about -<NUM> degrees Celsius, preferably between about -<NUM> degrees Celsius and about -<NUM> degrees Celsius, and subsequently sub-cooled to a temperature between about -<NUM> degrees Celsius and about -<NUM> degrees Celsius, preferably between about -<NUM> degrees Celsius and about -<NUM> degrees Celsius. CWHE <NUM> is a coil wound heat exchanger with three bundles. However, any number of bundles and any exchanger type may be utilized.

Refrigeration duty for the CWHE <NUM> is provided by a mixed refrigerant that is cooled and compressed in a compression system <NUM>. The warm mixed refrigerant is withdrawn from the bottom of the CWHE <NUM> at stream <NUM>, cooled and compressed, then reintroduced into the tube bundles through streams <NUM>, <NUM>. The mixed refrigerant is withdrawn, expanded, and reintroduced in the shell side of the CWHE <NUM> via streams <NUM>, <NUM>. Additional details concerning the natural gas liquefaction system can be found in <CIT>. The system <NUM> shown in <FIG> is identical to the system shown in <FIG> of <CIT>.

In view of the of the disclosed embodiments, the integration of the pressure containing shell (i.e., pressure vessel) into the module frame inclusive of piping outside as well as internal to the CWHE reduces manufacturing time, cost, and field work through simultaneous mechanical work and winding of the bundle. Once the wound bundle is completed it can be telescoped into the pressure shell that is already disposed within the module frame for final assembly. This method allows for completion of electrical and mechanical work, including both electrical systems and piping systems (both internal and external) within the module frame prior to completion of manufacturing of the mandrel with the wound bundle. It also allows for the manufacturing of the pressure shell and assembly to be completed at different sites to optimize labor availability and cost. In addition, the use of saddles that are configured to support both horizontal and vertical loads of the pressure vessels aids in: performing the electrical and mechanical work on the pressure shell within the module frame, supporting the horizontal pressure vessel during shipping of the pressure vessel within the module frame, and supporting the erected pressure vessel within the module frame at the operation site, including during operation.

<FIG> provides a flow diagram of an exemplary method of assembly, transport, and installation of a heat exchange module in accordance with the exemplary embodiments described herein. The process commences with construction of the shell (step <NUM>) and winding of tubes around the mandrel to form a wound bundle (step <NUM>). When the shell has been formed, the module frame, including the saddles and lug, is constructed (step <NUM>) and attached to the shell (step <NUM>). When the wound bundle is finished, it is telescoped (inserted) into the shell (step <NUM>) and the top end of the shell is closed (step <NUM>).

Constructing and attaching the module frame to the shell prior to telescoping the wound bundle into the shell provides a number of benefits. The structural stability of the module frame reduces stress on the shell during telescoping, transition to transportation, during transportation, and during erection of the shell at the plant side. In some applications, this will enable the shell to be thinner (and therefore lighter) and less costly. For example, the bracing force used to stabilize the shell during the telescoping step <NUM> can be applied to the module frame instead of being applied directly to the shell. Similarly, when the shell is being moved (lifted) in preparation for transportation (step <NUM>) and erected and installed at the plant site (step <NUM>), the moving/lifting forces can be applied to the module frame instead of being applied directly to the shell. In addition, in installations where the heat exchanger consists of multiple shells (see <FIG> and <FIG>), the upper shell (e.g., shell <NUM> of <FIG>) can be installed by simply bolting its module frame to the module frame of the lower shell (e.g., shell <NUM> of <FIG>).

Claim 1:
A method comprising:
(a) suspending a coil wound heat exchanger in a substantially vertical orientation above a platform with at least one saddle (436a-d) and at least one lug (441a-b) that are each rigidly connected to the coil wound heat exchanger and are each connected to a module frame (460a-b, 466a-b);
(b) rigidly affixing the at least one lug (441a-b) to the module frame (460a-b, 466a-b);
(c) enabling the at least one saddle (436a-d) to move relative to the module frame (460a-b, 466a-b) in a direction parallel to a longitudinal axis of the coil wound heat exchanger when the coil wound heat exchanger transitions from ambient temperature to an operating temperature;
(d) telescoping a coil wound mandrel (<NUM>) into a shell (<NUM>, <NUM>, <NUM>, <NUM>) of the coil wound heat exchanger with the shell of the coil wound heat exchanger in a substantially horizontal orientation; and
(e) supporting the coil wound heat exchanger during step (d) using the at least one saddle (436a-d) and at least one lug (441a-b) that suspend the coil wound heat exchanger in step (a).