Patent Description:
A HRSG is a heat exchanger generally utilized to recover heat from an exhaust gas. For example, the HRSG may be a part of a combined cycle power plant (CCPP) having one or more gas turbine engines configured to combust an air-fuel mixture to generate combustion gases. The combustion gases may drive rotation of a turbine of the gas turbine engine, which may be coupled to a load (e.g., electrical generator) that uses the rotational energy to generate electricity for a power grid. The combustion gases may exit the turbine as exhaust gas, which retains heat after passing through the turbine. The exhaust gas may ultimately be passed to the HRSG. The HRSG may include one or more stages (e.g., pressure stages), each of which including an evaporator (e.g., water coils) over which the exhaust gas is directed. The exhaust gas may heat the water in the evaporator, thereby generating steam collected and/or separated from the water in a drum connected to a top of the evaporator (e.g., directly or indirectly). The steam may be utilized to drive one or more steam turbines of the CCPP. In this way, the HRSG operates as a thermodynamic link between the gas turbine(s) and the steam turbine(s) of the CCPP.

In traditional embodiments, drums of the traditional HRSG and/or other equipment generally disposed at a top of the traditional HRSG may be heavy and difficult to interface with other portions of the traditional HRSG, leading to construction complexities that can be tedious and take a considerable amount of time. It is now recognized that improved HRSG componentry and construction techniques are desired.

The invention as herein claimed is related to an HRSG according to independent claim <NUM> and a method of constructing an HRSG as set forth in independent method claim <NUM>.

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 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.

In a second embodiment, a top platform auxiliary module of a heat recovery steam generator (HRSG) includes a frame. The top platform auxiliary module also includes a terminal connection disposed within the frame and configured to couple to a corresponding terminal connection disposed within a base of the HRSG. The top platform auxiliary module also includes a mounting assembly extending outwardly from the frame and configured to receive a mounting feature of the base of the HRSG, the mounting assembly being spaced from the terminal connection a distance such that, when the mounting assembly interfaces with the mounting feature, the terminal connection of the top platform auxiliary module is aligned for coupling with the corresponding terminal connection.

In a third embodiment, a method of constructing a heat recovery steam generator (HRSG) includes forming a first top platform auxiliary module having a first frame with a first generally flat bottom surface, and having a steam manifold disposed in the first frame. The method also includes forming a second top platform auxiliary module having a second frame with a second generally flat bottom surface, and having a high pressure (HP) drum disposed in the second frame. The method also includes forming a third top platform auxiliary module having a third frame with a third generally flat bottom surface, and having a low pressure (LP) drum and intermediate pressure (IP) drum disposed in the third frame. The method also includes lifting the first top platform auxiliary module to elevation, and disposing 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 in a plane formed by the base. The method also includes lifting the second top platform auxiliary module to elevation, and disposing the second top platform auxiliary module on the base of the HRSG such that the second generally flat bottom surface of the second top platform auxiliary module is disposed in the plane formed by the base. The method also includes lifting the third top platform auxiliary module to elevation, and disposing the third top platform auxiliary module on the base of the HRSG such that the third generally flat bottom surface of the third top platform auxiliary module is disposed in the plane formed by the base.

These and other features, aspects, and advantages of the present subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:.

One or more specific embodiments of the present subject matter will be described below. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with systemrelated and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of the herein claimed invention.

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 elements.

A heat recovery steam generator (HRSG) is a heat exchanger generally utilized in a combined cycle power plant (CCPP). The HRSG may flow a hot gas stream (e.g., exhaust gas) from one or more gas turbines of the CCPP across an evaporator (e.g., water coils) in order to generate steam utilized for powering one or more steam turbines of the CCPP. In this way, the HRSG operates as a thermodynamic link between the gas turbine(s) and the steam turbine(s) of the CCPP.

In traditional embodiments, a base of the HRSG (e.g., having an exhaust gas flow path, one or more evaporators, and associated equipment) is designed and constructed, and other components, such as drums and piping (e.g., a steam manifold) of the HRSG, are lifted individually to a top of the base and adapted to connect to the base and corresponding components. For example, the base in traditional embodiments may be modularized and/or standardized, and the drums and manifolds/piping that are disposed on the top of the base are lifted to elevation and connected to the modularized components of the base. The components lifted to the top of the base may be heavy and cumbersome, and it may be necessary to alter the connection techniques on a caseby-case basis (e.g., customized for a particular site or project). These connection techniques executed at elevation may be tedious and complicated, at least because the components disposed on top of the base are heavy and difficult to maneuver. Thus, in traditional embodiments, significant construction/assembly time is spent on interfacing the components disposed on the top of the base with the components residing within the base.

It is presently recognized that construction time of the HRSG can be improved by first modularizing and standardizing the features disposed on the top of the base of the HRSG, and then designing the base, if needed, to accommodate the modules. For example, several "top platform auxiliary modules" may be constructed on the ground, and may have standard sizes, shapes, and terminal connections that can be used for various HRSG embodiments. The top platform auxiliary modules may include, for example, a first top platform auxiliary module in which piping or a manifold (e.g., steam manifold) and corresponding equipment (e.g., silencers, cable trays) are disposed, a second top platform auxiliary module in which a high pressure (HP) drum and corresponding equipment (e.g., silencers, cable trays) are disposed, and a third top platform auxiliary module in which an intermediate pressure (IP) drum, a low pressure (LP) drum, and corresponding equipment (e.g., silencers, cable trays) are disposed. Each top platform auxiliary module may include a generally rectangular frame in which the above-described components are installed, where the generally rectangular frame includes a generally planar bottom side easily received by the base of the HRSG. For example, the base of the HRSG may include a generally planar surface formed by upper ends of one or more columns of the base. Further, each top platform auxiliary module may be constructed on the ground and then elevated (e.g., by cranes) to be disposed on the top of the base of the HRSG. That is, the drums, silencers, cable trays, piping, manifolds, and/or terminal connections associated with the top platform auxiliary modules may be installed in the top platform auxiliary modules prior to lifting the top platform auxiliary modules to the top of the base of the HRSG, such that all of the components corresponding to each module may be lifted at once with the corresponding module. In other embodiments (not shown), the modules may include components different from those described above, but the modules may be similarly constructed on the ground prior to being raised to elevation to form the top platform assembly.

As suggested above, columns of the base, and the connections of the base (e.g., heat exchanger connections, such as superheater, economizer, or evaporator connections), may be designed to fit and/or receive the top platform auxiliary modules, including the modularized/standardized terminal connections of the top platform auxiliary modules. Alterations to accommodate interfacing the top platform auxiliary modules with the base may reside in the base, which may be easier to alter because the equipment is closer to the ground. For example, the columns of the base (and corresponding heat exchange equipment in the columns, such as superheaters, evaporators, and/or economizers) may be spaced a particular distance such that the connections of the base (e.g., heat exchanger connections, such as evaporator connections, superheater connections, or economizer connections) corresponding to each column are appropriately spaced for connecting to the features (e.g., terminal connections, such as terminal fluid connections) residing in the top platform auxiliary modules. Thus, when each top platform auxiliary module is lifted (e.g., via a two-crane technique) to the top of the base of the HRSG, assembly of the top platform auxiliary modules atop the base of the HRSG is simplified relative to traditional embodiments. Indeed, the base may include a planar surface, or several surfaces forming a plane, on which the top platform auxiliary modules are disposed. Further, the top platform auxiliary modules may include a mounting assembly (e.g., a pair of extensions, hooks, arms, or claws) that interface with, or receive, a mounting feature (e.g., a slide-in plate) extending along the top of the base, which positions each top platform auxiliary module with respect to the base and corresponding equipment, and mounts each top platform auxiliary module to the base. After the top platform auxiliary modules are disposed atop the base of the HRSG, the top platform auxiliary modules, and other features built after disposal of the top platform auxiliary modules atop the base, may form a "top platform assembly. " These features are described in detail below with respect to the drawings.

By way of introduction, <FIG> is a schematic diagram of an embodiment of a combined cycled power plant (CCPP) <NUM>. In the illustrated embodiment, the CCPP <NUM> includes a gas turbine system <NUM>, a steam turbine system <NUM>, and a heat recovery steam generator (HRSG) <NUM> disposed between the gas turbine system <NUM> and the steam turbine system <NUM>. The HRSG <NUM> is generally configured to enable heat transfer from an exhaust gas <NUM> of the gas turbine system <NUM> to a fluid (e.g., water <NUM>) of the steam turbine system <NUM>, thereby generating steam <NUM> for use in the steam turbine system <NUM>. As shown, separate streams of steam <NUM> may be generated, such as a high pressure (HP) steam, an intermediate pressure (IP) steam, and a low pressure (LP) steam, each of which being received by a different area or section of a steam turbine <NUM> of the steam turbine system <NUM>.

The gas turbine system <NUM> may include a compressor <NUM>, one or more combustors <NUM>, and a turbine <NUM>. In operation, an oxidant (e.g., air, oxygen, oxygen enriched air, or oxygen reduced air) is received by the compressor <NUM>. The compressor <NUM> pressurizes the air in a series of compressor stages (e.g., rotor disks) with compressor blades. As the compressed air exits the compressor <NUM>, the air enters the combustor <NUM> and mixes with a fuel. The air-fuel mixture may be ignited in the combustor <NUM>, which then directs the combustion products through one or more turbine stages of the turbine <NUM>. As the combustion products pass through the turbine <NUM>, the combustion products contact turbine blades attached to turbine rotor disks (e.g., one of the turbine stages, each having turbine blades disposed circumferentially about the axis). As the combustion products travel through the turbine <NUM>, the combustion products may force turbine blades to rotate the rotor disks. The rotation of the rotor disks induces rotation of at least one shaft <NUM> and rotation of the rotor disks in the compressor <NUM> (e.g., which may be rotatably coupled with the one of the shafts <NUM>). A load <NUM> (e.g., electrical generator) of the gas turbine system <NUM> connects to the one of the shafts <NUM> and uses the rotational energy of the shaft <NUM> to generate electricity for use by a power grid. The combustion products then exit the gas turbine <NUM> as the exhaust gas <NUM>.

As previously described, the exhaust gas <NUM> may then be routed to the HRSG <NUM>, along with the water <NUM>, whereby the HRSG <NUM> utilizes the exhaust gas <NUM> to heat the water <NUM> and generate pressurized steam. The steam turbine system <NUM> includes the steam turbine <NUM>, a shaft <NUM>, and a load <NUM> (e.g., electrical generator). As the hot pressurized steam <NUM> enters the steam turbine <NUM>, the steam <NUM> contacts turbine blades attached to turbine rotor disks (e.g., turbine stages). As the steam <NUM> passes through the turbine stages in the steam turbine <NUM>, the steam <NUM> induces the turbine blades to rotate the rotor disks. The rotation of the rotor disks induces rotation of the shaft <NUM>. As illustrated, the load <NUM> (e.g., electrical generator) connects to the shaft <NUM>. Accordingly, as the shaft <NUM> rotates, the load <NUM> (e.g., electrical generator) uses the rotational energy to generate electricity for the power grid. As the pressurized steam <NUM> passes through the steam turbine <NUM>, the steam <NUM> loses energy (i.e., expands and cools). After exiting the steam turbine <NUM>, the steam exhaust may enter a condenser <NUM>, which converts the steam exhaust to the water <NUM> routed back to the HRSG <NUM>.

<FIG> is a schematic diagram illustrating the HRSG <NUM> containing a low pressure (LP) section <NUM>, an intermediate pressure (IP) section <NUM>, and a high pressure (HP) section <NUM>. Each section <NUM>, <NUM>, <NUM> may be configured to generate the steam <NUM> at various pressures. For example, the LP section <NUM> may generate LP steam <NUM>, the IP section <NUM> may generate IP steam <NUM>, and the HP section <NUM> may generate HP steam <NUM>.

The components of the HRSG <NUM> in the illustrated embodiment are simplified and are not intended to be limiting. That is, <FIG> should not be read as denoting a relative ordering or positioning of the LP section <NUM>, the IP section <NUM>, the HP section <NUM>, or any of the individual components in each of these sections <NUM>, <NUM>, <NUM>. Rather, the illustrated HRSG <NUM> is shown to convey the general operation of certain HRSG systems. As discussed above, the exhaust gas <NUM> may be routed to and through the HRSG <NUM> via a first flow path and used to heat the water <NUM> routed to the HRSG <NUM> via one or more second flow paths. The exhaust gas <NUM> may heat the water <NUM> in each section <NUM>, <NUM>, <NUM> of the HRSG <NUM>.

As illustrated in no particular order, the LP section <NUM> includes an LP economizer <NUM>, an LP evaporator <NUM>, an LP drum <NUM>, and an LP superheater <NUM>. The LP economizer <NUM> may be a device configured to pre-heat the water <NUM> to prepare the water <NUM> for receiving heat from the exhaust gas <NUM>. For example, the LP economizer <NUM> may generally pre-heat the water <NUM> to an ideal temperature for controlling an amount of heat required to generate the steam <NUM>. The LP economizer <NUM> may then direct the pre-heated water <NUM> to other components of the HRSG <NUM>, for example, the LP drum <NUM>. The LP drum <NUM> may be a storage container that feeds the water <NUM> to the LP evaporator <NUM>. The LP evaporator <NUM> may receive the pre-heated water <NUM> to further heat the water <NUM> to generate the steam <NUM>. In some embodiments, the water <NUM> may be in a vapor form before, during, or after being heated by the exhaust gas <NUM> in the LP evaporator <NUM>. The steam <NUM> may then be received by the LP superheater <NUM>, which may convert saturated steam produced by the LP evaporator <NUM> into superheated or dry steam (e.g., the steam <NUM>).

As illustrated, the IP section <NUM> may include an IP economizer <NUM>, an IP evaporator <NUM>, an IP drum <NUM>, and an IP superheater <NUM>. The IP economizer <NUM>, the IP evaporator <NUM>, the IP drum <NUM>, and the IP superheater <NUM> may have similar functionality as the LP economizer <NUM>, the LP evaporator <NUM>, the LP drum <NUM>, and the LP superheater <NUM>, respectively. Further, as illustrated, the HP section <NUM> includes an economizer <NUM>, an evaporator <NUM>, a drum <NUM>, and a superheater <NUM>. The HP economizer <NUM>, the HP evaporator <NUM>, the HP drum <NUM>, and the HP superheater <NUM> may have similar functionality as the LP economizer <NUM>, the LP evaporator <NUM>, the LP drum <NUM>, and the LP superheater <NUM>, respectively. Of course, as previously described, HRSGs <NUM> in accordance with the invention as herein claimed may include fewer components or other components than those described above. In particular, the HRSG <NUM> may additionally include one or more steam manifolds configured to receive the steam <NUM> and direct the steam <NUM> toward the steam turbine system <NUM> illustrated in <FIG>.

As suggested in the description above, the HRSG <NUM> of <FIG> (and CCPP of <FIG>) can be large and require complicated construction methods. In industrial scale embodiments, for example, a top of the HRSG <NUM> may be elevated <NUM> meters (approximately <NUM> feet) or more above the ground. Further, certain heavy and/or cumbersome components of the HRSG <NUM> may be disposed at the top of the HRSG <NUM>. For example, the LP drum <NUM>, IP drum <NUM>, and HP drum <NUM> illustrated in the schematic diagram of <FIG> may be disposed at or adjacent to the top of the HRSG <NUM>. Associated piping connecting the drums <NUM>, <NUM>, <NUM> to the various other components of the HRSG <NUM> may also be disposed at or adjacent to the top of the HRSG <NUM>.

In traditional embodiments, a base of the HRSG <NUM> may be designed and constructed first, and the components disposed at the top of the HRSG <NUM> may be raised individually, for example, by one or more cranes, and then adapted at elevation to fit on, or couple to, the base of the HRSG <NUM>. That is, in traditional embodiments, the base of the HRSG <NUM> may be constructed in standard modules having certain of the components disposed below the top of the HRSG <NUM>, such as the evaporators, economizers, and/or superheaters. In these traditional embodiments, the components disposed at the top of the HRSG <NUM> are not modularized, and are instead adapted, modified, devised, or otherwise improvised to fit the modules forming the base of the HRSG <NUM>. This traditional construction technique may include procedures at elevation that are not efficient, which can substantially increase construction time.

It is presently contemplated that, in accordance with the invention as herein claimed, the components disposed at or adjacent to the top of the HRSG <NUM> may be modularized with standard features (referred to herein as "top platform auxiliary modules"), and the base of the HRSG <NUM> may be designed around the features of the top platform auxiliary modules.

For example, <FIG> illustrates an embodiment of a portion of the HRSG <NUM> having a top platform assembly <NUM> and a base <NUM>. The illustrated embodiment does not include a smoke stack or an exhaust gas duct, although it should be appreciated that these components would normally be included on ends <NUM> of the HRSG <NUM>. As shown, three top platform auxiliary modules <NUM>, <NUM>, <NUM> form the top platform assembly <NUM> and are disposed on top of the base <NUM>. Of course, each of the top platform auxiliary modules <NUM>, <NUM>, <NUM> is assembled individually (e.g., on the ground <NUM>), and each top platform auxiliary module <NUM>, <NUM>, <NUM> is individually lifted from the ground <NUM> to a top of the base <NUM> and disposed on the top of the base <NUM>. The components residing within each top platform auxiliary module <NUM>, <NUM>, <NUM> are, as previously described, pre-arranged and standardized. That is, terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM> are arranged first, prior to elevating the top platform auxiliary modules <NUM>, <NUM>, <NUM> to elevation, and the connection portions (e.g., evaporator connections, superheater connections, or economizer connections) from the base <NUM> are constructed to be coupled to the terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM> (for example, via intermediary pipe segments). That is, as shown, the base <NUM> may include columns <NUM> disposed in a row, where the columns <NUM> are spaced at particular distances <NUM> to ensure that the components within the columns <NUM>, and connection features of the components disposed within the columns <NUM>, are appropriately spaced for receiving and connecting the top platform auxiliary modules <NUM>, <NUM>, <NUM> after they are lifted to the top of the base <NUM>. In the illustrated embodiment, the columns <NUM> may be spaced distances <NUM> of, for example, between <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), or <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet).

Further, the standardized terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM> may be designed to accommodate reception of a range of pressure parts disposed in the base <NUM>. That is, the top platform auxiliary modules <NUM>, <NUM>, <NUM> may be designed to accommodate columns <NUM> spaced any distance <NUM> within one of the above-described ranges. Thus, the top platform auxiliary modules <NUM>, <NUM>, <NUM>, despite being standardized, are versatile for interfacing with various size bases <NUM>, depending on output needs of the HRSG <NUM>.

In the illustrated embodiment, and as shown in <FIG>, the first top platform auxiliary module <NUM> includes piping (or a steam manifold <NUM>), cable trays, and silencers <NUM>, which are disposed at least partially in, and/or integrated with, a frame <NUM> of the first top platform auxiliary module <NUM>. The frame <NUM> of the first top platform auxiliary module <NUM> includes an approximate length x width x height of <NUM> meters x <NUM> meters x <NUM> meters (<NUM> feet x <NUM> feet x <NUM> feet), with an approximate weight of <NUM> tons. The first top platform auxiliary module <NUM> does not include the LP drum <NUM>, the IP drum <NUM>, or the HP drum <NUM>. The second top platform auxiliary module <NUM> (shown in <FIG>) includes the HP drum <NUM>, cable trays, and silencers <NUM>, which are disposed at least partially in, and/or integrated with, a frame <NUM> of the second top platform auxiliary module <NUM>. The frame <NUM> of the second top platform auxiliary module <NUM> includes an approximate length x width x height of <NUM> meters x <NUM> meters x <NUM> meters (<NUM> feet x <NUM> feet x <NUM> feet), with an approximate weight of <NUM> tons. The second top platform auxiliary module <NUM> does not include the LP drum <NUM>, the IP drum <NUM>, or the steam manifold <NUM>. The third top platform auxiliary module <NUM> (shown in <FIG>) includes the IP drum <NUM>, the LP drum <NUM>, cable trays, and silencers <NUM>, which are disposed at least partially in, and/or integrated with, a frame <NUM> of the third top platform auxiliary module <NUM>. The frame <NUM> of the third top platform auxiliary module <NUM> includes an approximate length x width x height of <NUM> meters x <NUM> meters x <NUM> meters (<NUM> feet x <NUM> feet x <NUM> feet), with an approximate weight of <NUM> tons. The third top platform auxiliary module <NUM> does not include the steam manifold <NUM> or the HP drum <NUM>.

As shown in <FIG> and described above, the frames <NUM>, <NUM>, <NUM> of the top platform auxiliary modules <NUM>, <NUM>, <NUM> may each include the same length and height. In the illustrated embodiment, the frame <NUM> of the first top platform auxiliary module <NUM> includes a different width than the frame <NUM> of the second top platform auxiliary module <NUM> and the frame <NUM> of the third top platform auxiliary module <NUM>. It should be noted that, in accordance with the herein claimed invention, each dimension of the frames <NUM>, <NUM>, <NUM> of each top platform auxiliary module <NUM>, <NUM>, <NUM> may be varied by as much as +/- <NUM>%. For example, the sizing of the frame <NUM> of the first top platform auxiliary module <NUM> may be within the following ranges: (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters to <NUM> meters [<NUM> feet to <NUM> feet]). Further, the sizing of the frame <NUM> of the second top platform auxiliary module <NUM> may be within the following ranges: (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]). Further still, the sizing of the frame <NUM> of the third top platform auxiliary module <NUM> may be within the following ranges: (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]) x (<NUM> meters - <NUM> meters [<NUM> feet to <NUM> feet]). It should also be noted that the above-described ranges are not limited by the ratio included in the more precise examples above. In other words, the frame <NUM> of the third top platform auxiliary module <NUM> could include the following sizing, which is within the above described ranges: <NUM> meters x <NUM> meters x <NUM> meters (<NUM> feet x <NUM> feet x <NUM> feet). However, in general, the frames <NUM>, <NUM>, <NUM> of the top platform auxiliary modules <NUM>, <NUM>, <NUM> may each include the same length and height, whereas the frame <NUM> of the first top platform auxiliary module <NUM> may include a different width than the frames <NUM>, <NUM> of the second top platform auxiliary module <NUM> and the third top platform auxiliary module <NUM>, respectively.

Further, for each top platform auxiliary module <NUM>, <NUM>, <NUM>, the width and height may be a function (e.g., ratio) of the length. For example, the first top platform auxiliary module <NUM> may include a length of L, a width of <NUM>, and a height of <NUM>. The second top platform auxiliary module <NUM> may include a length of L, a width of <NUM>, and a height of <NUM>. The third top platform auxiliary module <NUM> may include a length of L, a width of <NUM>, and a height of <NUM>. However, the above-described ratios may differ slightly, depending on the embodiment. For example, the first top platform auxiliary module <NUM> may include a length of L, a width of <NUM> - <NUM>, and a height of <NUM> - <NUM>. The second top platform auxiliary module <NUM> may include a length of L, a width of <NUM> - <NUM>, and a height of <NUM> - <NUM>. The third top platform auxiliary module <NUM> may include a length of L, a width of <NUM> - <NUM>, and a height of <NUM> - <NUM>.

It should also be noted that, in certain circumstances, shipping constraints may require that the top platform auxiliary modules <NUM>, <NUM>, <NUM> include smaller heights than those described above. For example, in certain circumstances in which shipping constraints are present, each of the top platform auxiliary modules <NUM>, <NUM>, <NUM> may be split into two portions along the height dimension, each portion having half the height disclosed in the above examples. That is, the footprints (i.e., length x width) may remain the same, but the module may be halved along the height dimension. In such embodiments, the split portions of each top platform auxiliary module <NUM>, <NUM>, <NUM> may be connected on the ground prior to being lifted to elevation. In other embodiments, each of the six portions may be lifted to elevation individually.

As shown in <FIG>, the top platform auxiliary modules <NUM>, <NUM>, <NUM> disposed on the top of the base <NUM>, and forming the top platform assembly <NUM>, may hang over a perimeter of the base <NUM>. Because the top platform auxiliary modules <NUM>, <NUM>, <NUM> are assembled/constructed on the ground, including the generally rectangular frames thereof, components that would otherwise hang over beyond the perimeter of the base <NUM> and require cumbersome assembly techniques with respect to the base <NUM> are instead easily disposed on the base <NUM> while contained within the sturdy, rigid modules <NUM>, <NUM>, <NUM>.

<FIG> illustrate each of the top platform auxiliary modules <NUM>, <NUM>, <NUM>, respectively. That is, <FIG> illustrates the first top platform auxiliary module <NUM> having the steam manifold <NUM>, two of the silencers <NUM>, and the cable trays, <FIG> illustrates the second top platform auxiliary module <NUM> having the HP drum <NUM>, three of the silencers <NUM>, and the cable trays, and <FIG> illustrates the third top platform auxiliary module <NUM> having the IP drum <NUM>, the LP drum <NUM>, cable trays, and three of the silencers <NUM>. As shown in <FIG>, each top platform auxiliary module <NUM>, <NUM>, <NUM> may include a generally planar, or flat, bottom surface <NUM>, which may include a solid surface or frame members (e.g., forming a mesh or lattice structure). The generally planar bottom surfaces <NUM> of the modules <NUM>, <NUM>, <NUM> (and/or the generally rectangular shapes of the frames) may enable improved disposal of the modules <NUM>, <NUM>, <NUM> on top of the HRSG base. In other embodiments, the modules <NUM>, <NUM>, <NUM> may include a different shape that is common between them.

Further, each top platform auxiliary module <NUM>, <NUM>, <NUM> may include a corresponding frame <NUM>, <NUM>, <NUM> configured to receive any of a family of differently sized components. For example, focusing in particular on the top platform auxiliary module <NUM> having the HP drum <NUM> in <FIG>, the frame <NUM> of the top platform auxiliary module <NUM> may be sized in accordance with the above description to receive any of a family of differently sized HP drums <NUM>. That is, the frame <NUM> having the above-described size could receive any of a number of differently sized HP drums <NUM> depending on the power needs of the corresponding HRSG and/or CCPP. By way of non-limiting example, the above-described frame <NUM> can receive the HP drum <NUM> having an approximate total height between <NUM> meter (<NUM> feet) and <NUM> meters (<NUM> feet). Further, the above-described frame <NUM> can receive the HP drum <NUM> having an approximate total length between <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet). Of course, as previously described, the presently contemplated embodiments may be scaled for various sized HRSGs. Thus, the disclosed concept of including a modular frame (e.g., the frame <NUM>) configured to receive any of a family of differently sized components, depending on power needs, may be applied to a smaller HRSG or a larger HRSG than those included in the examples provided herein.

<FIG> and <FIG> include top and bottom perspective views, respectively, of the top platform <NUM>. For example, <FIG> illustrates the top platform <NUM> formed by the first top platform auxiliary module <NUM>, the second top platform auxiliary module <NUM>, and the third top platform auxiliary module <NUM>. As shown, the modules <NUM>, <NUM>, <NUM> are connected to each other, which causes connection of walkways <NUM> (e.g., formed by platform grating material, such as steel grating material) pre-disposed in the various modules <NUM>, <NUM>, <NUM>, to form a workable space. It should be appreciated that the silencers <NUM>, and certain other components illustrated in <FIG>, are removed from <FIG> and <FIG> for clarity regarding other features of the top platform assembly <NUM>. It should also be appreciated that the silencers <NUM>, and certain other components illustrated in <FIG>, which may limit logistics optimization, may be installed in the top platform auxiliary modules <NUM>, <NUM>, <NUM> on the ground, prior to their elevation and formation of the illustrated top platform assembly <NUM>.

As shown in <FIG>, the top platform auxiliary modules <NUM>, <NUM>, <NUM> may be connected after they are disposed on the base of the HRSG. A walkway <NUM> (shown in <FIG> and <FIG>) may be formed above a lower side <NUM> (shown in <FIG>) of the frame of each module <NUM>, <NUM>, <NUM>. Further, terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM> may extend downwardly from the top platform auxiliary modules <NUM>, <NUM>, <NUM>, for connection to base connections of the base <NUM> (see <FIG>). PUP pieces <NUM> (illustrated in <FIG>) may be utilized to connect terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM> with the corresponding base connections. "PUP pieces" may be used in in connection with the herein claimed invention to refer to a short length of pipe utilized to couple two other pipe connections (e.g., terminal connections of the modules <NUM>, <NUM>, <NUM> with corresponding terminal connections of the base <NUM>).

In the illustrated embodiment, the PUP pieces <NUM> are disposed on the ends of the terminal connections of the top platform auxiliary modules <NUM>, <NUM>, <NUM>. However, it should be understood that the top platform auxiliary modules <NUM>, <NUM>, <NUM> may be disposed on the base <NUM> of the HRSG <NUM> without the PUP pieces <NUM> attached to the terminal connections, and the PUP pieces <NUM> may be utilized to couple the terminal connections with the base connections after the terminal connections and the base connections are aligned (e.g., via the mounting/alignment features of the HRSG). For example, as will be appreciated in view of <FIG> and corresponding description, each of the top platform modules <NUM>, <NUM>, <NUM> may include mounting and/or alignment features configured to appropriately position the top platform modules <NUM>, <NUM>, <NUM> relative to the base <NUM> (see <FIG>) such that the terminal connections and corresponding base connections are aligned for coupling, for example via the intervening PUP pieces <NUM> illustrated in <FIG>. As previously described, the terminal connections are standardized as a part of the modules <NUM>, <NUM>, <NUM>, and are configured to fit, with minimal adaptation, a range of pressure parts in the base <NUM> (see <FIG>) of the HRSG <NUM> (see <FIG>). That is, the modules <NUM>, <NUM>, <NUM> may be standardized to fit multiple embodiments of the base <NUM>, where each embodiment of the base <NUM> may include different sized pressure parts (e.g., based on power needs) than the other embodiments of the base <NUM>. These features will be described in detail with reference to <FIG>.

<FIG> illustrate features that enable positioning of the top platform auxiliary modules <NUM>, <NUM>, <NUM> relative to the base <NUM>, such that the base connections and top platform auxiliary module terminal connections align. For example, as illustrated in <FIG>, and as previously described, the base <NUM> may include several columns <NUM> spaced particular distances <NUM> away from each other to ensure that the components (e.g., evaporator sections, superheater sections, economizer sections) and connection portions thereof within the columns <NUM> will align with the terminal connections protruding from the top platform auxiliary modules (not shown). The distances <NUM> may be, for example, between <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet), or <NUM> meters (<NUM> feet) and <NUM> meters (<NUM> feet).

At a top <NUM> of the base <NUM>, ridges <NUM> may extend upwardly from the base <NUM>. The ridges <NUM> each correspond to one of the columns <NUM>. Each ridge <NUM> extends a similar distance upwardly, such that a substantially flat plane <NUM> extends across the tops of the ridges <NUM>. The top platform auxiliary modules (not shown) may be configured to be disposed on the tops of the ridges <NUM>, such that bottoms of the top platform auxiliary modules (not shown) are disposed on the tops of the ridges <NUM>. For example, as previously described, each top platform auxiliary module <NUM>, <NUM>, <NUM> may include a generally flat or planar bottom surface <NUM> which is received along the flat plane <NUM> defined by the ridges <NUM> of the base <NUM>.

<FIG> illustrate how the columns <NUM> of the base <NUM> are spaced the aforementioned distances <NUM> to facilitate simplified connections between the components of the base <NUM> and the components of the modules <NUM>, <NUM>, <NUM> (e.g., in conjunction with the above-described mounting features <NUM> (e.g., hooks, extensions, arms, claws) that interface with the ridges <NUM> of the base <NUM>, as illustrated in <FIG> also illustrates the smoke stack <NUM> disposed at one end <NUM> of the base <NUM> and the inlet duct <NUM> (e.g., for receiving exhaust gas from one or more gas turbines) disposed at the other end <NUM> of the base <NUM>.

As shown in the schematic illustration of <FIG>, each top platform auxiliary module (for example, top platform auxiliary modules <NUM>, <NUM> in the illustrated embodiment) may include terminal connections <NUM> configured to interface with base connections <NUM> of components within the base <NUM> (e.g., with PUP pieces <NUM> extending between the terminal connections <NUM> and the base connections <NUM>). As shown, the top platform auxiliary modules (for example, modules <NUM>, <NUM> in the illustrated embodiment) may include alignment and/or mounting features <NUM> (e.g., pairs of hooks, claws, arms, or extensions) between which the ridges <NUM> are configured to be disposed. That is, each pair of mounting features <NUM> may include two arms with a gap between the two arms, where the gap is configured to receive one of the ridges <NUM>. The mounting features <NUM> (e.g., pairs of hooks, claws, arms, or extensions) may be spaced a distance <NUM> from the terminal connections <NUM> of the modules such that, upon receiving the ridges <NUM> of the base <NUM> in a gap between the mounting features <NUM> of the module <NUM> or <NUM>, the base connections <NUM> are aligned with the terminal connections <NUM> of the modules, thereby simplifying the connection between the terminal connections <NUM> and the corresponding base connections <NUM>. In this way, the ridges <NUM> may be referred to as "slide-in plates. " It should be noted that terminal connections <NUM> of the modules <NUM>, <NUM> and base connections <NUM> of the base <NUM> may refer to fluid connections (e.g., piping), electrical connections, and/or mechanical connections.

It should also be appreciated that, in some embodiments, the ridges <NUM> may be used specifically for receiving bottom ends of the modules, and that the mounting features <NUM> (e.g., extensions, hooks, arms, claws) of the modules <NUM>, <NUM> may be configured to interface with other slide-in plates protruding from the base <NUM>. It should also be noted that "terminal connections <NUM>" may refer to, for example, conduit or other fluid connections, electrical connections, or strictly mechanical connections. Further, corresponding "base connections <NUM>" may refer to conduit or other fluid connections, electrical connections, or strictly mechanical connections. In other words, the interface between the mounting features <NUM> of the modules <NUM>, <NUM>, <NUM> and the slide-in plates (or ridges) <NUM> of the base <NUM> may be utilized to guide the connections <NUM> (e.g., fluid, electrical, or mechanical) of the modules <NUM>, <NUM>, <NUM> toward the connections <NUM> (e.g., fluid, electrical, or mechanical) of the base, such that the PUP pieces <NUM> can be attached between the terminal connections <NUM> and the base connections <NUM>. <FIG> are perspective views of an embodiment of interfacing features of one of the top platform auxiliary modules <NUM> with the ridge <NUM> (or slide-in plate), as previously described. <FIG> illustrates the mounting features <NUM> (e.g., extensions, hooks, arms, claws) of the top platform auxiliary module <NUM>, extending downwardly from the generally planar bottom surface <NUM> of the top platform auxiliary module <NUM>. <FIG> illustrates the mounting features <NUM> (e.g., extensions, hooks, arms, claws) interfacing with the ridge <NUM> (e.g., receiving the ridge <NUM>, or slide-in plate, between the two mounting features <NUM>).

As previously described, each top platform auxiliary module may be lifted from the ground to a top of the base of the HRSG. For example, <FIG> and <FIG> are perspective views of an embodiment of a construction maneuver in which the second top platform auxiliary module <NUM> is lifted from the ground toward a top of the base of the HRSG of <FIG>. <FIG> illustrates the second top platform auxiliary module <NUM> at a first elevation during the construction (or installation) maneuver and <FIG> illustrates the second top platform auxiliary module <NUM> at a second elevation during the construction (or installation) maneuver. As shown, a first crane <NUM> and a second crane <NUM> may be utilized to lift the second top platform auxiliary module <NUM>, which was pre-arranged and formed on the ground, to elevation (e.g., toward a top of a base of the HRSG). By modularizing a number of components generally disposed at a top of the base of the HRSG as shown, the components can be interfaced with the base of the HRSG with fewer tedious and time-consuming techniques than traditional embodiments. Because of the weight of the module <NUM>, the two cranes <NUM>, <NUM> may be disposed on either side of the module <NUM>, and may lift the module <NUM> on either side, thereby stabilizing the lifting technique. In traditional embodiments, a single, smaller crane may be used to lift individual components over a larger number of lifting maneuvers, which may contribute to longer construction time.

<FIG> is an embodiment of a method <NUM> of constructing the HRSG of <FIG>. The method includes forming (block <NUM>), on the ground, a first top platform auxiliary module having a frame and piping (e.g., a steam manifold), and associated equipment. The method <NUM> also includes forming (block <NUM>), on the ground, a second top platform auxiliary module having a frame and a high pressure (HP) drum, and associated equipment. The method <NUM> also includes forming (block <NUM>), on the ground, a third top platform auxiliary module having a frame, an intermediate pressure (IP) drum, a low pressure (LP) drum, and associated equipment. It should be noted that, in blocks <NUM>, <NUM>, and <NUM>, the modules may be formed off-site and shipped onsite having already been assembled.

The method <NUM> also includes lifting (block <NUM>) the first top platform auxiliary module to elevation, and disposing the first top platform auxiliary module on the base of the HRSG. The method <NUM> also includes lifting (block <NUM>) the second top platform auxiliary module to elevation, and disposing the second top platform auxiliary module on the base of the HRSG. The method <NUM> also includes lifting (block <NUM>) the third top platform auxiliary module to elevation, and disposing the third top platform auxiliary module on the base of the HRSG. In blocks <NUM>, <NUM>, and <NUM>, each corresponding module may include a generally flat or planar bottom surface configured to be disposed in a plane formed by the base of the HRSG. For example, as previously described, the plane may be defined by ridges extending from columns of the base of the HRSG, where each column corresponds to particular HRSG equipment. Further, when disposing the modules on the top of the base of the HRSG, mounting features of the modules (e.g., extensions, claws, arms, hooks) may receive the ridges (and/or other slide-in plates) of the base of the HRSG. The mounting features of the modules may be spaced a particular distance from terminal connections (e.g., fluid connections, such as piping) of the modules configured to be coupled to base connections (e.g., fluid connections, such as piping) of the base. Thus, the space between the columns and the base connections of the base may be designed to accommodate the space between the mounting features and terminal connections of the modules.

It should be noted that the above-described 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 modules can also be utilized in other types of HRSGs, such as a once-through HRSG. A once-through HRSG may not include an HP drum. For example, in a once-through HRSG, the IP drum and LP drum may be segmented into two separate top platform auxiliary modules, with a third top platform auxiliary module containing a steam manifold. In another once-through HRSG, only two top platform auxiliary modules may be used (e.g., one having a steam manifold, the other having both the IP and LP drums). In still another once-through HRSG, multiple manifolds and/or piping assemblies may include dedicated top platform auxiliary modules (e.g., a first top platform auxiliary module corresponding to a first manifold, and a second top platform auxiliary module corresponding to a second manifold). Thus, it should be appreciated that the above-described examples in <FIG>, certain of which relating to triple-pressure HRSGs, can also be applied to other types of HRSGs, such as the above-described once-through HRSG.

Technical effects of the invention include improving construction time of a HRSG, simplifying construction techniques of the HRSG, reducing construction and manufacturing costs of the HRSG, reducing shipping costs and complexity for parts of the HRSG, and improving operability of the HRSG.

Claim 1:
A heat recovery steam generator (HRSG) (<NUM>), comprising:
a base (<NUM>) having a base top (<NUM>) defining a perimeter and a plurality of columns (<NUM>); and
a top platform assembly (<NUM>) disposed on the base (<NUM>), the top platform assembly (<NUM>) comprising:
a first top platform auxiliary module (<NUM>) having a first rectangular frame (<NUM>) in which a steam manifold (<NUM>) is disposed;
a second top platform auxiliary module (<NUM>) having a second rectangular frame (<NUM>) in which a high pressure (HP) drum (<NUM>) is disposed; and
a third top platform auxiliary module (<NUM>) having a third rectangular frame (<NUM>) in which at least one of a low pressure (LP) drum (<NUM>) and an intermediate pressure (IP) drum (<NUM>) is disposed;
wherein, based on the shape and components of the first top platform auxiliary module (<NUM>), the second top platform auxiliary module (<NUM>), and the third top platform auxiliary module (<NUM>), the plurality of the columns (<NUM>) of the base (<NUM>) are spaced at particular distances to support the top platform assembly (<NUM>) and to facilitate coupling of the components to the base (<NUM>);
wherein the base top (<NUM>) defines a plane (<NUM>) on which the first top platform auxiliary module (<NUM>), the second top platform auxiliary module (<NUM>), and the third top platform auxiliary module (<NUM>) are disposed in a row; and
wherein the top platform assembly (<NUM>) extends beyond the perimeter of the base top (<NUM>).