System and method for heat recovery steam generator (HRSG) top platform assembly

Abstract

The heat recovery steam generator (HRSG) includes a base and a top platform assembly disposed on the base. The top platform assembly includes a first top platform auxiliary module having a first rectangular frame in which a steam manifold is disposed, a second top platform auxiliary module having a second rectangular frame in which a high-pressure (HP) drum is disposed, and a third top platform auxiliary module having a third rectangular frame in which a low-pressure (LP) drum and an intermediate-pressure (IP) drum are disposed. Each of the top platform auxiliary modules may be pre-assembled on the ground before being raised for installation on the base.

Description

[Technical field]

[0001] The subject matter disclosed herein relates to a system and method for assembling a heat recovery steam generator (HRSG) that includes an HRSG top platform assembly. [Background technology]

[0002] HRSGs are heat exchangers commonly used in recovering heat from exhaust gases. For example, the HRSG may be part of a combined cycle power plant (CCPP) having one or more gas turbine engines configured to combust a fuel-air mixture to generate combustion gases. The combustion gases may drive the rotation of a turbine of the gas turbine engine, which may be coupled to a load (e.g., a generator) that uses the rotational energy to generate power for a power grid. The combustion gases may exit the turbine as exhaust gases that retain heat after passing through the turbine. The exhaust gases may ultimately be routed to the HRSG. The HRSG may include one or more stages (e.g., pressure stages), each of which includes an evaporator (e.g., a water coil) through which the exhaust gases are routed. The exhaust gases may heat water in the evaporator, thereby generating steam (e.g., directly or indirectly) that is collected and / or separated from water in a drum coupled to the top of the evaporator. The steam may be used to drive one or more steam turbines of the CCPP. In this manner, the HRSG serves as a thermodynamic link between the gas turbine(s) and the steam turbine(s) of the CCPP.

[0003] In conventional embodiments, the drum of a conventional HRSG and / or other equipment typically placed on top of a conventional HRSG is heavy and can be difficult to mate with other portions of the conventional HRSG, resulting in cumbersome and significantly time consuming construction complexities. It is now recognized that improvements in HRSG components and assembly techniques are desirable. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 191266 Brochure Summary of the Invention

[0005] Certain embodiments commensurate in scope with the initially claimed subject matter are summarized below. These embodiments are not intended to limit the scope of the claimed subject matter; rather, these embodiments are intended only to provide a brief summary of possible forms of the subject matter. Indeed, the subject matter may encompass a variety of forms that may be similar to or different from the embodiments set forth below.

[0006] In a first embodiment, a heat recovery steam generator (HRSG) includes a base and a top platform assembly disposed on the base, the top platform assembly including a first top platform auxiliary module having a first rectangular frame on which a steam manifold is disposed, a second top platform auxiliary module having a second rectangular frame on which a high pressure (HP) drum is disposed, and a third top platform auxiliary module having a third rectangular frame on which a low pressure (LP) drum and an intermediate pressure (IP) drum are disposed.

[0007] In a second embodiment, a top platform auxiliary module of a heat recovery steam generator (HRSG) includes a frame. The top platform auxiliary module further includes a terminal fitting disposed within the frame and configured to couple to a corresponding terminal fitting disposed within a base of the HRSG. The top platform auxiliary module further includes a mounting assembly extending outwardly from the frame and configured to receive a mounting feature in the base of the HRSG, the mounting assembly being spaced a distance from the terminal fitting such that when the mounting assembly mates with the mounting feature, the terminal fitting of the top platform auxiliary module is aligned to couple with the corresponding terminal fitting.

[0008] In a third embodiment, a method of assembling a heat recovery steam generator (HRSG) includes forming a first top platform auxiliary module having a first frame including a first generally flat bottom surface and having a steam manifold disposed within the first frame. The method further includes forming a second top platform auxiliary module having a second frame including a second generally flat bottom surface and having a high pressure (HP) drum disposed within the second frame. The method further includes forming a third top platform auxiliary module having a third frame including a third generally flat bottom surface and having a low pressure (LP) drum and an intermediate pressure (IP) drum disposed within the third frame. The method further includes lifting the first top platform auxiliary module up and then placing the first top platform auxiliary module on a base of the HRSG such that the first generally flat bottom surface of the first top platform auxiliary module is disposed within a plane defined by the base. The method further includes raising a second top platform assist module up and then placing the second top platform assist module on a base of the HRSG such that a second substantially flat bottom surface of the second top platform assist module is disposed in a plane defined by the base. The method further includes raising a third top platform assist module up and then placing the third top platform assist module on a base of the HRSG such that a third substantially flat bottom surface of the third top platform assist module is disposed in a plane defined by the base.

[0009] These and other features, aspects, and advantages of the present subject matter will be better understood from the following detailed description when read in conjunction with the accompanying drawings, in which like reference numerals represent like parts throughout. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram illustrating an embodiment of a combined cycle power plant (CCPP). [Diagram 2] FIG. 2 is a block diagram illustrating one embodiment of a heat recovery steam generator (HRSG) in the CCPP of FIG. [Diagram 3] 3 is a perspective view of one embodiment of the HRSG of FIG. 2 with a top platform assembly positioned on the base. [Figure 4] FIG. 4 is a perspective view of one embodiment of a top platform assist module for the top platform assembly of the HRSG shown in FIG. 3, where the top platform assist module includes a steam manifold. [Diagram 5] FIG. 4 is a perspective view of one embodiment of a top platform assist module for the top platform assembly of the HRSG shown in FIG. 3, where the top platform assist module includes a high pressure (HP) drum. [Figure 6] FIG. 4 is a perspective view of one embodiment of a top platform assist module for the top platform assembly of the HRSG shown in FIG. 3, where the top platform assist module includes a low pressure (LP) drum and an intermediate pressure (IP) drum. [Figure 7] 4 is a top perspective view of one embodiment of a portion of the top platform assembly of the HRSG shown in FIG. 3 (with certain components removed for clarity). [Figure 8] 4 is a bottom perspective view of one embodiment of a portion of the top platform assembly of the HRSG shown in FIG. 3 (with certain components removed for clarity). [Figure 9] FIG. 4 is a perspective view of one embodiment of the base of the HRSG shown in FIG. [Figure 10] FIG. 4 is a side view of one embodiment of the HRSG shown in FIG. [Figure 11] 11 is a side view of a portion of the HRSG of FIG. 10 taken along line 11-11. [Figure 12] FIG. 4 is a schematic diagram illustrating one embodiment of a joining mechanism between the top platform assembly and the base of the HRSG shown in FIG. [Figure 13]FIG. 4 is a perspective view of one embodiment of an attachment mechanism for a top platform auxiliary module for the top platform assembly of the HRSG shown in FIG. [Figure 14] 14 is a perspective view of one embodiment of the joining mechanism shown in FIG. 13 engaging a sliding engagement plate (or post) on the base of the HRSG shown in FIG. 3. FIG. [Figure 15] 4 is a perspective view illustrating one embodiment of a step in an assembly operation in which the top platform support module is raised from the ground toward the top of the base of the HRSG shown in FIG. [Figure 16] 16 is a perspective view showing another step of the assembly operation shown in FIG. 15. FIG. [Figure 17] 4 illustrates one embodiment of a method for assembling the HRSG shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] One or more specific embodiments of the subject matter of the present invention are described below. While an effort is made to describe these embodiments concisely, it may not be possible to describe all features of a practical implementation herein. It should be understood that the development of any such practical implementation, as with any engineering or design project, will require numerous implementation-specific decisions to be made in order to achieve the developer's particular goals, including compliance with system-related and business-related constraints that may vary from implementation to implementation. It should also be understood that such a development effort may be complex and time-consuming, but would nevertheless be no more than a routine undertaking of design, fabrication, and manufacture for those of ordinary skill in the art having the benefit of this disclosure.

[0012] When introducing elements of various embodiments of the present subject matter, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the element. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0013] A heat recovery steam generator (HRSG) is a heat exchanger commonly utilized in combined cycle power plants (CCPPs). The HRSG may pass a hot gas stream (e.g., exhaust gas) from one or more gas turbines of the CCPP through an evaporator (e.g., water-passing coil) to generate steam that is used in powering one or more steam turbines of the CCPP. In this manner, the HRSG serves as a thermodynamic link between one or more gas turbines and one or more steam turbines of the CCPP.

[0014] In conventional embodiments, the base of the HRSG (e.g., having an exhaust gas flow path, one or more evaporators, and corresponding equipment) is designed and assembled, and other components of the HRSG, such as drums and piping (e.g., steam manifolds), are adapted to be individually raised to the top of the base and connected to the base and corresponding components. For example, the base in conventional embodiments may be modularized and / or standardized, and the drums and manifolds or piping located at the top of the base are raised high and connected to the modularized components of the base. The components raised to the top of the base may be heavy and cumbersome, and therefore the connection method may need to be changed on a case-by-case basis (e.g., customized for a particular work site or project). Such connection methods performed at a certain height may be cumbersome and complicated, at least due to the components located on the base being heavy and difficult to move. Thus, in conventional embodiments, a lot of construction or assembly time is spent to join the components located at the top of the base with the components located within the base.

[0015] It is now recognized that the assembly time of the present HRSG may be improved by first modularizing and standardizing the features located on the top of the base of the present HRSG, and then designing the base to accommodate these modules, as needed. For example, several "top platform auxiliary modules" may be assembled on the ground, and may have standard sizes, shapes, and terminal fittings that can be used for various HRSG embodiments. These top platform auxiliary modules may include, for example, a first top platform auxiliary module in which piping or manifolds (e.g., steam manifolds) and corresponding equipment (e.g., silencers, cable trays) are located, a second top platform auxiliary module in which high pressure (HP) drums and corresponding equipment (e.g., silencers, cable trays) are located, and a third top platform auxiliary module in which intermediate pressure (IP) drums, low pressure (LP) drums, and corresponding equipment (e.g., silencers, cable trays) are located. Each of the top platform auxiliary modules may include a generally rectangular frame on which the above-mentioned components are mounted, the generally rectangular frame including a generally planar bottom surface that is easily received by the base of the HRSG. For example, the base of the HRSG may include a generally planar surface formed by the upper ends of one or more support columns of the base. Additionally, each of the top platform auxiliary modules may be assembled on the ground and then lifted (e.g., by a crane) to be placed on the top of the base of the HRSG. That is, the drums, silencers, cable trays, piping, manifolds, and / or end fittings corresponding to the top platform auxiliary module may be installed on the top platform auxiliary module before the top platform auxiliary module is lifted to the top of the base of the HRSG, thereby allowing all components corresponding to each module to be lifted at once with the corresponding module. In other embodiments (not shown), the modules may include different components than those described above, but the modules may be similarly assembled on the ground before being lifted aloft to form the top platform assembly.

[0016] As alluded to above, the base struts and base fittings (e.g., heat exchanger fittings such as superheater fittings, economizer fittings, or evaporator fittings) may be designed to fit and / or be accommodated in the top platform auxiliary module, including modularized or standardized terminal fittings of the top platform auxiliary module. Modifications to accommodate joining of the top platform auxiliary module to the base may occur in the base, which may make the modifications easier since the equipment is closer to the ground. For example, the base struts (and corresponding heat exchange equipment therein, such as superheater, evaporator, and / or economizer) may be spaced apart at a specific distance so that the base fittings (e.g., heat exchanger fittings such as evaporator fittings, superheater fittings, or economizer fittings) corresponding to each strut are connected at an appropriate distance to features provided in the top platform auxiliary module (e.g., terminal fittings such as terminal fluid fittings). Thus, when each of the top platform auxiliary modules is lifted (e.g., using a two-crane technique) to the top of the base of the HRSG, assembly of the top platform auxiliary modules onto the base of the HRSG is simplified as compared to prior embodiments. In fact, the base may include a plane, or multiple surfaces that form a plane, on which the top platform auxiliary modules are placed. Additionally, the top platform auxiliary modules may include a mounting assembly (e.g., a pair of extensions, hooks, arms, or claws) that interfaces with or receives a mounting mechanism (e.g., a slide engagement plate) that extends along the top of the base, which positions each top platform auxiliary module relative to the base and corresponding equipment, and then attaches each top platform auxiliary module to the base. After the top platform auxiliary modules are placed on the base of the HRSG, the top platform auxiliary modules and other mechanisms that are assembled after placing the top platform auxiliary modules on the base may form a "top platform assembly." These mechanisms are described in more detail below in conjunction with the drawings.

[0017] To begin with, Figure 1 is a schematic diagram of one embodiment of a combined cycle power plant (CCPP) 10. In the illustrated embodiment, the CCPP 10 includes a gas turbine system 14, a steam turbine system 16, and a heat recovery steam generator (HRSG) 18 disposed between the gas turbine system 14 and the steam turbine system 16. The HRSG 18 is typically configured to provide heat transfer from an exhaust gas 20 of the gas turbine system 14 to a fluid (e.g., water 22) in the steam turbine system 16, thereby generating steam 24 for use by the steam turbine system 16. As illustrated, separate streams of steam 24, such as high pressure (HP) steam, intermediate pressure (IP) steam, and low pressure (LP) steam, may be generated, with each of these streams being received by a different region or section of a steam turbine 26 of the steam turbine system 16.

[0018] The gas turbine system 14 may include a compressor 28, one or more combustors 30, and a turbine 32. During operation, an oxidant (e.g., air, oxygen, oxygen-enriched air, or oxygen-reduced air) is received by the compressor 28. The compressor 28 compresses the air in a series of compressor stages (e.g., rotor disks) using compressor blades. As the compressed air exits the compressor 28, it enters a combustor 30 where it is mixed with fuel. The mixture may be ignited in the combustor 30, which then routes the combustion products through one or more turbine stages of a turbine 32. As the combustion products pass through the turbine 32, they contact turbine blades (e.g., one of the turbine stages, each having turbine blades arranged circumferentially about an axis) attached to a turbine rotor disk. As they travel through the turbine 32, the combustion products may cause the turbine blades to rotate the rotor disk. This rotation of the rotor disk induces rotation of at least one shaft 34 and rotation of a rotor disk within the compressor 28 (e.g., which may be rotatably coupled to one of the shafts 34). A load 36 (e.g., a generator) of the gas turbine system 14 is coupled to one of the shafts 34 and uses the rotational energy of the shaft 34 to generate electricity for use by an electric power grid. The products of combustion then exit the gas turbine 32 as exhaust gases 20.

[0019] As previously described, the exhaust gas 20 is then sent to the HRSG 18 along with the water 22, which utilizes the exhaust gas 20 to heat the water 22 to generate pressurized steam. The steam turbine system 16 includes a steam turbine 26, a shaft 38, and a load 40 (e.g., a generator). As the hot pressurized steam 24 enters the steam turbine 26, it contacts turbine blades (e.g., turbine stages) mounted on a turbine rotor disk. As the steam 24 passes through the turbine stages of the steam turbine 26, the steam 24 causes the turbine blades to rotate the rotor disk. This rotation of the rotor disk induces rotation of the shaft 38. As shown, the load 40 (e.g., a generator) is coupled to the shaft 38. Thus, as the shaft 38 rotates, the load 40 (e.g., a generator) uses the rotational energy to generate power for the power grid. As the pressurized steam 24 passes through the steam turbine 26, the pressurized steam 24 loses energy (i.e., expands and cools). After exiting the steam turbine 26 , the exhaust steam may enter a condenser 42 , which converts the exhaust steam into water 22 that is returned to the HRSG 18 .

[0020] 2 is a schematic diagram illustrating HRSG 18 including a low pressure (LP) section 50, an intermediate pressure (IP) section 60, and a high pressure (HP) section 70. Sections 50, 60, 70 may each be configured to produce steam 24 at various pressures. For example, LP section 50 may produce LP steam 51, IP section 60 may produce IP steam 61, and HP section 70 may produce HP steam 71.

[0021] The components of the HRSG 18 in the illustrated embodiment are simplified, but are not intended to be limiting. That is, FIG. 2 should not be read as a relative ordering or positioning of the LP section 50, IP section 60, HP section 70, or any of the individual components of each of these sections 50, 60, 70. Rather, the illustrated HRSG 18 is shown to convey the normal operation of an HRSG system. As mentioned above, the exhaust gas 20 is routed to and through the HRSG 18 via a first flow path and may then be used to heat the water 22 routed to the HRSG 18 via one or more second flow paths. The exhaust gas 20 may heat the water 22 in each section 50, 60, 70 of the HRSG 18.

[0022] The LP section 50 includes, in no particular order, an LP economizer 52, an LP evaporator 54, an LP drum 56, and an LP superheater 58. The LP economizer 52 may be a device configured to preheat the water 22 to prepare the water 22 for receiving heat from the exhaust gas 20. For example, the LP economizer 52 may typically preheat the water 22 to a suitable temperature to control the amount of heat required to generate the steam 24. The LP economizer 52 may then send the preheated water 22 to other components of the HRSG 18, such as the LP drum 56. The LP drum 56 may be a storage vessel that provides the water 22 to the LP evaporator 54. The LP evaporator 54 may receive the preheated water 22 and further heat the water 22 to generate the steam 24. In some embodiments, the water 22 may be in the form of steam before, during, or after being heated by the exhaust gas 20 in the LP evaporator 54. The steam 24 may then be received by an LP superheater 58, which may convert the saturated steam produced by the LP evaporator 54 to superheated steam or dry steam (eg, steam 24).

[0023] As shown, the IP section 60 may include an IP economizer 62, an IP evaporator 64, an IP drum 66, and an IP superheater 68. The IP economizer 62, the IP evaporator 64, the IP drum 66, and the IP superheater 68 may have similar functions as the LP economizer 52, the LP evaporator 54, the LP drum 56, and the LP superheater 58, respectively. Additionally, as shown, the HP section 70 includes an economizer 72, an evaporator 74, a drum 76, and a superheater 78. The HP economizer 72, the HP evaporator 74, the HP drum 76, and the HP superheater 78 may have similar functions as the LP economizer 52, the LP evaporator 54, the LP drum 56, and the LP superheater 58, respectively. As previously mentioned, it will be appreciated that the HRSG 18 of the present disclosure may include fewer components or other components than those listed above. In particular, the HRSG 18 may further include one or more steam manifolds configured to receive the steam 24 and then route the steam 24 to the steam turbine system 16 shown in FIG.

[0024] As alluded to above, the HRSG 18 shown in FIG. 2 (and the CCPP of FIG. 1) may be large and therefore may require complex assembly methods. In an industrial-scale embodiment, for example, the top of the HRSG 18 may be elevated to a height of 30 meters (about 98 feet) or more above the ground. Additionally, certain components of the HRSG 18 that are heavy and / or cumbersome may be located at the top of the HRSG 18. For example, the LP drum 56, IP drum 66, and HP drum 76 shown in the schematic diagram of FIG. 2 may be located at or adjacent to the top of the HRSG 18. Corresponding piping connecting the drums 56, 66, 76 to various other components of the HRSG 18 may be located at or adjacent to the top of the HRSG 18 as well.

[0025] In conventional embodiments, the base of the HRSG 18 may be designed first and then assembled, and may be adapted to be at a height where the components located at the top of the HRSG 18 are individually lifted, for example, by one or more cranes, and then attached or coupled to the base of the HRSG 18. That is, in conventional embodiments, the base of the HRSG 18 may be assembled into standard modules that have certain components, such as evaporators, economizers, and / or superheaters, located below the top of the HRSG 18. In these conventional embodiments, the components located at the top of the HRSG 18 are not modularized, but instead are adapted, modified, invented, or otherwise extemporaneously provided to fit into the modules forming the base of the HRSG 18. This conventional assembly technique may involve steps that are performed at inefficient heights that may substantially increase assembly time.

[0026] In accordance with the present disclosure, components located on or adjacent to the top of HRSG 18 may be modularized with standard features (referred to herein as "top platform auxiliary modules"), and it is presently contemplated that the base of HRSG 18 may be designed around these features of the top platform auxiliary modules.

[0027] For example, FIG. 3 illustrates an embodiment of a portion of a HRSG 18 having a top platform assembly 100 and a base 101. The illustrated embodiment does not include a chimney or exhaust gas duct, although it is understood that these components may typically be included in the tip 90 of the HRSG 18. As illustrated, three top platform auxiliary modules 102, 104, 106 form the top platform assembly 100 and are positioned on top of the base 101. Of course, each of these top platform auxiliary modules 102, 104, 106 are individually assembled (e.g., on the ground) and each of these top platform auxiliary modules 102, 104, 106 are individually lifted from the ground to the top of the base 101 and positioned on top of the base 101. The components provided within each top platform auxiliary module 102, 104, 106 are pre-positioned and standardized as described above. That is, before these top platform support modules 102, 104, 106 are raised up, the terminal fittings of the top platform support modules 102, 104, 106 are first placed and then the fittings (e.g., evaporator fittings, superheater fittings, or economizer fittings) from the base 101 are connected (e.g., via intermediate conduit segments) to the terminal fittings of the top platform support modules 102, 104, 106. That is, as shown, the base 101 may include columns 103 arranged in a row, the columns 103 being spaced apart a certain distance 115 to ensure that the components within the columns 103 and the coupling mechanisms of the components located within the columns 103 are appropriately spaced to receive and connect the top platform support modules 102, 104, 106 after the base 101 is raised to the top of the base 101. In the illustrated embodiment, the posts 103 may be spaced apart a distance 115 of, for example, 2.0 meters (6.6 feet) to 5.0 meters (16.4 feet), 2.5 meters (8.2 feet) to 4.5 meters (14.8 feet), 3.0 meters (9.8 feet) to 4.0 meters (13.1 feet), or 3.25 meters (10.7 feet) to 3.75 meters (12.3 feet).

[0028] Additionally, the standardized end fittings of the top platform support modules 102, 104, 106 may be designed to accommodate a range of pressure components disposed within the base 101. That is, the top platform support modules 102, 104, 106 may be designed to accommodate columns 103 spaced apart any distance 115 within one of the ranges described above. Thus, despite being standardized, the top platform support modules 102, 104, 106 are versatile enough to be mated with a variety of sizes of bases 101 depending on the power output required by the HRSG 18.

[0029] In the illustrated embodiment, as shown in FIG. 4, the first top platform support module 102 includes piping (or steam manifold 111), cable tray, and silencer 112 that are at least partially disposed within and / or integrated with the frame 105 of the first top platform support module 102. The frame 105 of the first top platform support module 102 has an approximate length by width by height of 25.6 meters by 6.6 meters by 7.4 meters (84 feet by 22 feet by 24 feet) and an approximate weight of 130 tons. The first top platform support module 102 does not include the LP drum 56, the IP drum 66, and the HP drum 76. The second top platform support module 104 (shown in FIG. 5) includes the HP drum 76, cable tray, and silencer 112 that are at least partially disposed within and / or integrated with the frame 107 of the second top platform support module 104. The frame 107 of the second top platform auxiliary module 104 has an approximate length by width by height of 25.6 meters by 8.5 meters by 7.4 meters (84 feet by 28 feet by 24 feet) and an approximate weight of 350 tons. The second top platform auxiliary module 104 does not include the LP drum 56, the IP drum 66, and the steam manifold 111. The third top platform auxiliary module 106 (shown in FIG. 6 ) includes the IP drum 66, the LP drum 56, the cable tray, and the silencer 112, which are at least partially disposed within and / or integral with the frame 109 of the third top platform auxiliary module 106. The frame 109 of the third top platform auxiliary module 106 has an approximate length by width by height of 25.6 meters by 8.5 meters by 7.4 meters (84 feet by 28 feet by 24 feet) and an approximate weight of 222 tons. The third top platform auxiliary module 106 does not include the steam manifold 111 and the HP drum 76 .

[0030] 3 and described above, the frames 105, 107, 109 of the top platform support modules 102, 104, 106 may each include the same length and height. In the illustrated embodiment, the frame 105 of the first top platform support module 102 includes a different width than the frame 107 of the second top platform support module 104 and the frame 109 of the third top platform support module 106. It should be noted that according to the present disclosure, the dimensions of the frames 105, 107, 109 of each top platform support module 102, 104, 106 may each vary by approximately plus or minus 10%. For example, the dimensions of the frame 105 of the first top platform auxiliary module 102 may be within the following range: (23 meters to 28.2 meters [75.5 feet to 92.5 feet]) x (5.9 meters to 7.3 meters [19.4 feet to 24 feet]) x (6.7 meters to 8.1 meters [22 feet to 26.6 feet]). Further, for example, the dimensions of the frame 107 of the second top platform auxiliary module 104 may be within the following range: (23 meters to 28.2 meters [75.5 feet to 92.5 feet]) x (7.7 meters to 9.4 meters [25.3 feet to 30.8 feet]) x (6.7 meters to 8.1 meters [22 feet to 26.6 feet]). Further, for example, the dimensions of the frame 109 of the third top platform auxiliary module 106 may be within the following ranges: (23 meters to 28.2 meters [75.5 feet to 92.5 feet]) x (7.7 meters to 9.4 meters [25.3 feet to 30.8 feet]) x (6.7 meters to 8.1 meters [22 feet to 26.6 feet]). It should also be noted that the above ranges are not limited by the proportions included in the more detailed examples above. In other words, the frame 109 of the third top platform auxiliary module 106 may include the following dimensions within the above ranges: 23 meters x 9.4 meters x 7.0 meters (75.5 feet x 30.8 feet x 23 feet).Typically, however, the frames 105, 107, 109 of the top platform support modules 102, 104, 106 may each include the same length and height, while the frame 105 of the first top platform support module 102 may include a different width than the frames 107, 109 of the second top platform support module 104 and the third top platform support module 106, respectively.

[0031] Also, for each of these top platform auxiliary modules 102, 104, 106, the width and height may be a function (e.g., ratio) of the length. For example, the first top platform auxiliary module 102 may include a length L, a width of 0.26L, and a height of 0.29L. The second top platform auxiliary module 104 may include a length L, a width of 0.33L, and a height of 0.29L. The third top platform auxiliary module 106 may include a length L, a width of 0.33L, and a height of 0.29L. However, depending on the embodiment, the ratios may be slightly different. For example, the first top platform auxiliary module 102 may include a length L, a width of 0.21L to 0.31L, and a height of 0.24L to 0.35L. The second top platform auxiliary module 104 may include a length L, a width between 0.27L and 0.41L, and a height between 0.24L and 0.35L. The third top platform auxiliary module 106 may include a length L, a width between 0.27L and 0.41L, and a height between 0.24L and 0.35L.

[0032] It should also be noted that in certain circumstances, shipping constraints may require the height of the top platform auxiliary modules 102, 104, 106 to be reduced from the heights described above. For example, in certain circumstances where shipping constraints exist, each of the top platform auxiliary modules 102, 104, 106 may be split into two parts along the height dimension, each of which has half the height disclosed in the above example. That is, the footprint (i.e., length x width) may remain the same, but the modules may be halved along the height dimension. In such an embodiment, the split parts of each top platform auxiliary module 102, 104, 106 may be joined on the ground before being elevated. In other embodiments, each of the six parts may be elevated individually.

[0033] 3, the top platform auxiliary modules 102, 104, 106 disposed on the top of the base 101 and forming the top platform assembly 100 may protrude above the periphery of the base 101. The top platform auxiliary modules 102, 104, 106, including their generally rectangular frames, are assembled or constructed on the ground so that components that would otherwise protrude beyond the periphery of the base 101 and require cumbersome assembly techniques to the base 101 are instead housed within the sturdy rigid modules 102, 104, 106 and easily positioned on the base 101.

[0034] 4-6 show each of the top platform auxiliary modules 102, 104, 106, respectively. That is, FIG. 4 shows a first top platform auxiliary module 102 having a steam manifold 111, two silencers 112, and a cable tray, FIG. 5 shows a second top platform auxiliary module 104 having an HP drum 76, three silencers 112, and a cable tray, and FIG. 6 shows a third top platform auxiliary module 106 having an IP drum 66, an LP drum 56, a cable tray, and three silencers 112. As shown in FIG. 4-6, each of the top platform auxiliary modules 102, 104, 106 may include a substantially planar or substantially flat bottom surface 119, which may include a solid surface or frame member (e.g., forming a mesh or lattice structure). The generally planar bottom surface 119 of the modules 102, 104, 106 (and / or the generally rectangular shape of the frame) may allow for improved placement of the modules 102, 104, 106 on top of the base of the HRSG. In other embodiments, the modules 102, 104, 106 may include different shapes in common between them.

[0035] Additionally, each of the top platform auxiliary modules 102, 104, 106 may include a corresponding frame 105, 107, 109 configured to accommodate any of a group of differently sized components. For example, focusing specifically on the top platform auxiliary module 104 having the HP drum 76 of FIG. 5, the frame 107 of the top platform auxiliary module 104 may be sized in accordance with the above description to accommodate any of a group of differently sized HP drums 76. That is, the above-sized frame 107 may accommodate any of a number of differently sized HP drums 76 depending on the output required by the corresponding HRSG and / or CCPP. As a non-limiting example, the above-mentioned frame 107 may accommodate an HP drum 76 having an approximate overall height of 1.0 meters (3.3 feet) to 3.0 (9.8 feet). Additionally, the above-mentioned frame 107 may accommodate an HP drum 76 having an approximate overall length of 12 meters (39.4 feet) to 22 meters (72.2 feet). As previously mentioned, it will be appreciated that the presently contemplated embodiments may be scaled to fit various sizes of HRSGs, and thus the concepts disclosed herein of including a modular frame (e.g., frame 107) configured to accommodate any of a set of different sized components depending on the power output required may be applied to smaller or larger HRSGs than those included in the examples provided herein.

[0036] 7 and 8 include top and bottom perspective views, respectively, of the top platform 100. For example, FIG. 7 shows the top platform 100 formed by a first top platform auxiliary module 102, a second top platform auxiliary module 104, and a third top platform auxiliary module 106. As shown, the modules 102, 104, 106 are connected to each other, thereby connecting the scaffolding planks 120 (e.g., formed by platform lattice material, such as steel lattice material) pre-placed on the various modules 102, 104, 106 to form a workable space. It should be understood that the silencer 112, and certain other components shown in FIGS. 3-6, have been removed from FIGS. 7 and 8 to allow other features of the top platform assembly 100 to be clearly visible. It should also be understood that the silencer 112, and certain other components shown in Figures 3-6 that may limit the optimization of the installation, may be installed in the top platform auxiliary modules 102, 104, 106 on the ground prior to raising or forming the top platform assembly 100 as shown.

[0037] As shown in FIG. 7, the top platform support modules 102, 104, 106 may be connected after being placed on the base of the present HRSG. A scaffolding plate 120 (shown in FIGS. 7 and 8) may be formed on the underside 122 (shown in FIG. 8) of the frame of each module 102, 104, 106. Additionally, the terminal joints of the top platform support modules 102, 104, 106 may extend downwardly from the top platform support modules 102, 104, 106 to be connected to the base joints of the base 101 (see FIG. 3). The terminal joints of the top platform support modules 102, 104, 106 may be connected to the corresponding base joints using PUP members 124 (shown in FIG. 8). "PUP member" may be used in this disclosure to refer to a short length of conduit used in connecting two other conduit fittings (e.g., end fittings of modules 102, 104, 106 with corresponding end fittings in base 101).

[0038] In the illustrated embodiment, the PUP member 124 is disposed at the end of the terminal fittings of the top platform support modules 102, 104, 106. However, it should be understood that the top platform support modules 102, 104, 106 may be disposed on the base 101 of the HRSG 18 without the PUP member 124 attached to the terminal fittings, and the PUP member 124 may be used to connect the terminal fittings to the base fittings after the terminal fittings and base fittings are aligned (e.g., via attachment or alignment features of the HRSG). For example, as can be seen in FIG. 12 and the corresponding description, each of the top platform modules 102, 104, 106 may include mounting and / or alignment features configured to properly position the top platform modules 102, 104, 106 relative to the base 101 (see FIG. 3) such that their terminal fittings and corresponding base fittings are aligned to be coupled, for example, via the intervening PUP members 124 shown in FIG. 8. As previously mentioned, the terminal fittings are standardized as part of the modules 102, 104, 106 and are configured to fit, with minimal adjustment, a range of pressure components in the base 101 (see FIG. 3) of the HRSG 18 (see FIG. 3). That is, the modules 102, 104, 106 may be standardized to fit multiple embodiments of the base 101, with each embodiment of the base 101 including different sized pressure components (e.g., based on required power) than other embodiments of the base 101. These features are described in more detail with reference to FIG. 12.

[0039] 9-12 illustrate several features that allow for positioning of the top platform support modules 102, 104, 106 relative to the base 101 such that the base fittings are aligned with the terminal fittings of the top platform support modules. For example, as shown in FIG. 9 and as previously described, the base 101 may include a number of struts 103 spaced a particular distance 115 from one another to ensure that the components (e.g., evaporator section, superheater section, economizer section) and their fittings within the struts 103 are aligned with the terminal fittings protruding from the top platform support modules (not shown). This distance 115 may be, for example, between 2.0 meters (6.6 feet) and 5.0 meters (16.4 feet), between 2.5 meters (8.2 feet) and 4.5 meters (14.8 feet), between 3.0 meters (9.8 feet) and 4.0 meters (13.1 feet), or between 3.25 meters (10.7 feet) and 3.75 meters (12.3 feet).

[0040] At the top 99 of the base 101, ridges 121 may extend upwardly from the base 101. Each of these ridges 121 corresponds to one of the posts 103. Each of the ridges 121 extends upwardly a similar distance such that a generally flat plane 123 extends across the tip of the ridges 121. A top platform support module (not shown) may be configured to be disposed at the tip of the ridges 121 such that a bottom of the top platform support module (not shown) is disposed at the tip of the ridges 121. For example, as previously described, each of the top platform support modules 102, 104, 106 may include a generally flat or generally planar bottom surface 119 that is received along the flat plane 123 defined by the ridges 121 of the base 101.

[0041] 10 and 11 illustrate how the struts 103 of the base 101 are spaced apart the aforementioned distance 115 (e.g., in conjunction with the above-described attachment mechanisms 128 (e.g., hooks, extensions, arms, claws) that mate with the ridges 121 of the base 101 as shown in FIG. 10) to facilitate simplified connections between the components of the base 101 and the components of the modules 102, 104, 106. FIG. 10 further illustrates a chimney 130 located at one end 90 of the base 101 and an intake duct 132 (e.g., for receiving exhaust gases from one or more gas turbines) located at the other end 90 of the base 101.

[0042] 12, each of the top platform support modules (e.g., top platform support modules 102, 104 in the illustrated embodiment) may include an end joint 125 configured to mate with a base joint 126 of a component in the base 101 (e.g., where the PUP member 124 extends between the end joint 125 and the base joint 126). As shown, the top platform support modules (e.g., modules 102, 104 in the illustrated embodiment) may include alignment and / or attachment mechanisms 128 (e.g., a pair of hooks, claws, arms, or extensions) configured to have the ridges 121 disposed therebetween. That is, each pair of attachment mechanisms 128 may include two arms with a gap therebetween that is configured to accommodate one of the ridges 121. The mounting features 128 (e.g., a pair of hooks, tabs, arms, or extensions) may be spaced a distance 115 from the terminal fittings 125 of the module such that receiving the ridges 121 of the base 101 in the gaps between the mounting features 128 of the modules 102 or 104 aligns the base fittings 126 with the terminal fittings 125 of the module, thereby simplifying the connection of the terminal fittings 125 with the corresponding base fittings 126. In this manner, the ridges 121 may be referred to as a "slide engagement plate." It should be noted that the terminal fittings 125 of the modules 102, 104 and the base fittings 126 of the base 101 may refer to fluid fittings (e.g., piping), electrical fittings, and / or mechanical fittings.

[0043] It should also be appreciated that in some embodiments, ridge 121 may be used to accommodate, among other things, the bottom ends of modules, and attachment features 128 (e.g., extensions, hooks, arms, claws) of modules 102, 104 may be configured to mate with other slide-engagement plates protruding from base 101. It should also be noted that "end fitting 125" may refer to, for example, a conduit or other fluid fitting, an electrical fitting, or a strictly mechanical fitting. Furthermore, the corresponding "base fitting 126" may refer to, for example, a conduit or other fluid fitting, an electrical fitting, or a strictly mechanical fitting. In other words, the mating of the attachment features 128 of the modules 102, 104, 106 with the slide engagement plate (or ridge) 121 of the base 101 may be used to guide the joints 125 (e.g., fluid, electrical, or mechanical) of the modules 102, 104, 106 towards the joints 126 (e.g., fluid, electrical, or mechanical) of the base so that the PUP member 124 can be attached between the terminal joints 125 and the base joints 126. Figures 13 and 14 are perspective views illustrating one embodiment of mating the mating features of one of the top platform auxiliary modules 102 with the ridges 121 (or slide engagement plate) as previously described. Figure 13 illustrates the attachment features 128 (e.g., extensions, hooks, arms, claws) of the top platform auxiliary module 102 extending downward from the generally planar bottom surface 119 of the top platform auxiliary module 102. FIG. 13 shows how these attachment features 128 (e.g., extensions, hooks, arms, claws) are joined with the ridges 121 (e.g., receiving the ridges 121, or a sliding engagement plate, between two attachment features 128).

[0044] As previously discussed, each of the top platform support modules may be raised from the ground to the top of the base of the present HRSG. For example, Figures 15 and 16 are perspective views illustrating one embodiment of an assembly operation in which the second top platform support module 104 is raised from the ground toward the top of the base of the HRSG shown in Figure 3. Figure 15 illustrates the second top platform support module 104 at a first height during the assembly (or installation) operation, and Figure 16 illustrates the second top platform support module 104 at a second height during the assembly (or installation) operation. As shown, the second top platform support module 104, which has been pre-positioned and formed on the ground, may be raised higher (e.g., toward the top of the base of the present HRSG) using a first crane 140 and a second crane 142. As shown, by modularizing some of the components that are typically located at the top of the base of the HRSG, these components can be joined to the base of the HRSG in a less cumbersome and less time consuming technique than the conventional embodiment. Due to the weight of the module 104, two cranes 140, 142 may be located on either side of the module 104 and may lift the module 104 on either side, which will stabilize the lifting technique. In the conventional embodiment, one smaller crane may be used to lift the individual components through more lifting operations, which may contribute to longer assembly times.

[0045] FIG. 17 illustrates one embodiment of a method 200 for assembling the HRSG shown in FIG. 3. The method includes forming a first top platform auxiliary module on the ground (block 202) having a frame and piping (e.g., steam manifolds) and corresponding equipment. The method 200 further includes forming a second top platform auxiliary module on the ground (block 204) having a frame and a high pressure (HP) drum and corresponding equipment. The method 200 further includes forming a third top platform auxiliary module on the ground (block 206) having a frame, an intermediate pressure (IP) drum, a low pressure (LP) drum, and corresponding equipment. It should be noted that in blocks 202, 204, and 206, the modules may be formed off-site and shipped to the site already assembled.

[0046] The method 200 further includes raising a first top platform support module and then placing the first top platform support module on the base of the HRSG (block 208). The method 200 further includes raising a second top platform support module and then placing the second top platform support module on the base of the HRSG (block 210). The method 200 further includes raising a third top platform support module and then placing the third top platform support module on the base of the HRSG (block 212). In blocks 208, 210, and 212, the corresponding modules may each include a substantially flat or substantially planar bottom surface configured to be placed in a plane formed by the base of the HRSG. For example, as previously described, the plane may be defined by a ridge extending from a support column of the base of the HRSG, each of which corresponds to a particular HRSG installation. Additionally, the attachment features (e.g., extensions, tabs, arms, hooks) of the modules may accommodate the ridges (and / or other slide-engagement plates) of the HRSG base when the modules are placed on top of the HRSG base. The attachment features of the modules may be spaced a certain distance away from the terminal fittings (e.g., fluid fittings such as piping) of the modules that are configured to be coupled to the base fittings (e.g., fluid fittings such as piping) of the base. Thus, the space between the posts of the base and the base fittings may be designed to accommodate the space between the attachment features and the terminal fittings of the modules.

[0047] It should be noted that the above HRSG examples include a triple-pressure HRSG having an LP drum, an IP drum, and an HP drum. However, the disclosed modularized top platform auxiliary module may also be used in other types of HRSGs, such as a once-through HRSG. A once-through HRSG may not have an HP drum. For example, in a once-through HRSG, the IP drum and the LP drum may be split into two separate top platform auxiliary modules, with the third top platform auxiliary module including a steam manifold. In another once-through HRSG, only two top platform auxiliary modules may be used (e.g., one with a steam manifold and the other with both an IP drum and an LP drum). In yet another once-through HRSG, the multiple manifolds and / or piping assemblies may include dedicated top platform auxiliary modules (e.g., a first top platform auxiliary module corresponding to the first manifold and a second top platform auxiliary module corresponding to the second manifold). It should therefore be understood that the above examples of Figures 1-17 relating to a three-pressure HRSG may also be applied to other types of HRSGs, such as the flow-through HRSGs discussed above.

[0048] Technical effects of the present invention include improved HRSG assembly time, simplified HRSG assembly techniques, reduced HRSG assembly and manufacturing costs, reduced shipping costs and complexity of HRSG components, and improved HRSG operability.

[0049] This specification uses examples to disclose the invention, including the best mode, and to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are considered to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they include equivalent elements that do not differ in substantial degree from the literal language of the claims. [Explanation of symbols]

[0050] 10 Combined Cycle Power Plants (CCPPs) 14 Gas Turbine Systems 16 Steam Turbine System 18. Heat Recovery Steam Generator (HRSG) 20 Exhaust Gas 22 Water, preheated water 24 Steam, high-temperature pressurized steam 26 Steam Turbine 28 Compressor 30 Combustor 32 Gas Turbine 34 Shaft 36 Load 38 Shaft 40 Load 42 Condenser 50 Low Pressure (LP) Section 51 LP steam 52 LP Economizer 54 LP evaporator 56 LP drums 58 LP superheater 60 Medium Pressure (IP) Section 61 IP Steam 62 IP Economizer 64 IP Evaporator 66 IP Drum 68 IP superheater 70 High Pressure (HP) Section 71 HP Steam 72 HP Conomizer 74 HP Evaporator 76 HP drum 78 HP superheater 90 Tip 99 Top 100 Top platform, top platform assembly 101 Base 102 first top platform auxiliary module, top platform module, rigid module 103 Pillar section 104 second top platform auxiliary module, top platform module, rigidity module 105 Frames 106 third top platform auxiliary module, top platform module, rigid module 107 Frames 109 Frames 111 Steam manifold 112 Silencer 115 distance 119 Bottom 120 Scaffolding Board 121 Raised portion, slide engagement plate 122 Underside of frame 123 plane 124 PUP parts 125 Terminal joint 126 Base joint 128 Attachment mechanism 130 Chimney 132 Intake duct 140 First Crane 142 Second Crane 200 ways

Claims

1. A heat recovery steam generator (HRSG) (18), comprising: a base (101) having a base top (99) defining an outer periphery and a plurality of struts (103); a top platform assembly (100) disposed on said base (101); said top platform assembly (100) comprising: a first top platform auxiliary module (102) having a first rectangular frame (105) in which a steam manifold (111) is disposed; a second top platform auxiliary module (104) having a second rectangular frame (107) on which a high pressure (HP) drum (76) is disposed; a third top platform auxiliary module (106) having a third rectangular frame (109) on which at least one of a low pressure (LP) drum (56) and an intermediate pressure (IP) drum (66) is disposed; Equipped with Based on the shape and components of the first top platform support module (102), the second top platform support module (104) and the third top platform support module (106), a number of support posts (103) of the base (101) are spaced apart at specific distances to support the top platform assembly (100) and facilitate connection of the components to the base (101); the base top (99) defines a plane (123) on which the first top platform support module (102), the second top platform support module (104), and the third top platform support module (106) are disposed; The HRSG (18), wherein the top platform assembly (100) extends beyond the periphery of the base top (99).

2. 2. The HRSG (18) of claim 1, wherein the first rectangular frame (105), the second rectangular frame (107), and the third rectangular frame (109) have the same length or the same height, or both the same length and the same height.

3. 2. The HRSG (18) of claim 1, wherein the first rectangular frame (105) has a first width, the second rectangular frame (107) has a second width, and the third rectangular frame (109) has a third width, the first width being different than the second width and the third width.

4. 2. The HRSG (18) of claim 1, wherein each strut (103) of the plurality of struts (103) of the base (101) has at least one raised portion (121) that forms a portion of the plane (123) on which the first top platform support module (102), the second top platform support module (104), and the third top platform support module (106) are disposed.

5. 2. The HRSG (18) of claim 1, wherein the first top platform auxiliary module (102) having the first rectangular frame (105) and the steam manifold (111) is configured to be lifted from ground to the base top (99) in a first assembly operation, the second top platform auxiliary module (104) having the second rectangular frame (107) and the HP drum (76) is configured to be lifted from ground to the base top (99) in a second assembly operation, and the third top platform auxiliary module (106) having the third rectangular frame (109) and at least one of the LP drum (56) and the IP drum (66) is configured to be lifted from ground to the base top (99) in a third assembly operation.

6. Each of the first top platform support module (102), the second top platform support module (104), and the third top platform support module (106) comprises: a generally planar bottom surface (119) configured to engage the base top (99) of the base (101); an end fitting (125) disposed within each rectangular frame (105, 107, 109) and configured to be coupled to a corresponding base end fitting (126) disposed within the base (101) of the HRSG (18); a mounting assembly (128) extending outwardly from each rectangular frame (105, 107, 109) and configured to receive a mounting feature (121) of the base (101) of the HRSG (18), the mounting assembly (128) being spaced a distance (129) from an end fitting (125); Contains 6. The HRSG (18) of claim 1, wherein the terminal fittings (125) of each top platform auxiliary module (102, 104, 106) are aligned with corresponding base terminal fittings (126) when the mounting assembly (128) mates with the mounting mechanism (121).

7. 7. The HRSG (18) of claim 6, wherein each mounting assembly (128) includes a first arm, a second arm, and a gap between the first arm and the second arm, the gap between the first arm and the second arm configured to accommodate a respective mounting feature (121) of the base (101) of the HRSG (18).

8. 8. The HRSG (18) of claim 7, wherein each mounting mechanism (121) on the base (101) includes a slide engagement plate (121), and a gap between the first arm and the second arm is configured to accommodate the slide engagement plate (121) of the base (101) of the HRSG (18).

9. 7. The HRSG (18) of claim 6, wherein each end fitting (125) includes a conduit (124) configured to be fluidly connected with a corresponding base end fitting (126) such that a steam manifold (11) or drum (76, 56, 66) of each of the first, second and third top platform auxiliary modules (102, 104, 106) is fluidly connected with a heat exchanger component of the base (101).

10. A method for assembling a heat recovery steam generator (HRSG) (18), comprising the steps of: forming a first top platform auxiliary module (102) having a first frame (105) having a first generally flat bottom surface (119) and a steam manifold (111) disposed within the first frame (105); forming a second top platform auxiliary module (104) having a second frame (107) having a second generally flat bottom surface (119) and a high pressure (HP) drum (76) disposed within said second frame (107); forming a third top platform auxiliary module (106) having a third frame (109) having a third generally flat bottom surface (119) and a low pressure (LP) drum (56) and an intermediate pressure (IP) drum (66) disposed within the third frame (109); constructing a base (101) of the HRSG (18) having a plurality of struts (103) configured in predetermined positions based on the shapes and components of the first top platform support module (102), the second top platform support module (104), and the third top platform support module (106), such that the struts (103) support the first top platform support module (102), the second top platform support module (104), and the third top platform support module (106); raising the first top platform support module (102) and positioning the first top platform support module (102) on the base (101) of the HRSG (18) such that the first generally planar bottom surface (119) of the first top platform support module (102) is located within a plane (123) formed by the base (101); raising the second top platform support module (104) and positioning the second top platform support module (104) on the base (101) of the HRSG (18) such that the second generally planar bottom surface (119) of the second top platform support module (104) is located within a plane (123) formed by the base (101); raising the third top platform support module (106) and positioning the third top platform support module (106) on the base (101) of the HRSG (18) such that the third generally planar bottom surface (119) of the third top platform support module (106) is located within a plane (123) defined by the base (101); The method includes:

11. The method of claim 10, wherein the step of positioning the first top platform assist module (102) on the base (101) of the HRSG (18) includes engaging a mounting assembly (128) of the first top platform assist module (102) with a slide engagement plate (121) of the base (101), wherein an upper surface of the slide engagement plate (121) of the base (101) forms part of the plane (123).

12. 12. The method of claim 11, comprising spacing an end fitting (125) of the first top platform assist module (102) a distance (129) from a mounting assembly (128) of the first top platform assist module (102) such that the end fitting (125) aligns with a corresponding end fitting (126) of the base (101) of the HRSG (18) when the mounting assembly (128) is engaged with the slide engagement plate (121).

13. 11. The method of claim 10, wherein lifting the first top platform support module (102) includes utilizing a first crane (140) that engages the first top platform support module (102) from a first side of the first top platform support module (102) and a second crane (142) that engages the first top platform support module (102) from a second side of the first top platform support module (102) opposite the first side.

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