Modular Air Cooled Condenser Apparatus and Method
The present invention relates to a mechanical draft cooling tower that employs air cooled condenser modules. The aforementioned cooling tower operates by mechanical draft and achieves the exchange of heat between two fluids such as atmospheric air, ordinarily, and another fluid which is usually steam. The aforementioned cooling tower utilizes a modular air cooled condenser concept wherein the air cooled condensers utilize heat exchange deltas that use tube bundles that are manufactured and assembled prior to being shipped to the tower site.
This application claims priority to U.S. Provisional Application Ser. No. 61/828,076, filed on May 28, 2013, titled “MODULAR AIR COOLED CONDENSER APPARATUS AND METHOD,” the disclosure of which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTIONThe present invention relates to a mechanical draft cooling tower that utilizes air cooled condenser modules. The aforementioned cooling tower operates by mechanical draft and achieves the exchange of heat between two fluids such as atmospheric air, ordinarily, and another fluid which is usually steam or some sort of industrial process fluid. The aforementioned cooling tower operates by mechanical draft which utilizes an air current generator such as a fan or the like.
BACKGROUND OF THE INVENTIONCooling towers are heat exchangers of a type widely used to emanate low grade heat to the atmosphere and are typically utilized in electricity generation, air conditioning installations and the like. In a mechanical draft cooling tower for the aforementioned applications, airflow is induced or forced via an air flow generator such as a driven impeller, driven fan or the like. Cooling towers may be wet or dry. Dry cooling towers can be either “direct dry,” in which steam is directly condensed by air passing over a heat exchange medium containing the steam or an “indirect dry” type cooling towers, in which the steam first passes through a surface condenser cooled by a fluid and this warmed fluid is sent to a cooling tower heat exchanger where the fluid remains isolated from the air, similar to an automobile radiator. Dry cooling has the advantage of no evaporative water losses. Both types of dry cooling towers dissipate heat by conduction and convection and both types are presently in use. Wet cooling towers provide direct air contact to a fluid being cooled. Wet cooling towers benefit from the latent heat of vaporization which provides for very efficient heat transfer but at the expense of evaporating a small percentage of the circulating fluid.
To accomplish the required direct dry cooling the condenser typically requires a large surface area to dissipate the thermal energy in the gas or steam and oftentimes may present several challenges to the design engineer. It sometimes can be difficult to efficiently and effectively direct the steam to all the inner surface areas of the condenser because of non-uniformity in the delivery of the steam due to system ducting pressure losses and velocity distribution. Therefore, uniform steam distribution is desirable in air cooled condensers and is critical for optimum performance. Another challenge or drawback is, while it is desirable to provide a large surface area, steam side pressure drop may be generated thus increasing turbine back pressure and consequently reducing efficiency of the power plant. Therefore it is desirous to have a condenser with a strategic layout of ducting and condenser surfaces that allows for an even distribution of steam throughout the condenser that reduces back pressure, while permitting a maximum of cooling airflow throughout and across the condenser surfaces.
Another drawback to the current air cooled condenser towers is that they are typically very labor intensive in their assembly at the job site. The assembly of such towers oftentimes requires a dedicated labor force, investing a large amount of hours. Accordingly, such assembly is labor intensive requiring a large amount of time and therefore can be costly. Accordingly, it is desirable and more efficient to assemble as much of the tower structure at the manufacturing plant or facility, prior to shipping it to the installation site.
It is well known in the art that improving cooling tower performance (i.e. the ability to extract an increased quantity of waste heat in a given surface) can lead to improved overall efficiency of a steam plant's conversion of heat to electric power and/or to increases in power output in particular conditions. Moreover, cost-effective methods of manufacture and assembly also improve the overall efficiency of cooling towers in terms of cost-effectiveness of manufacture and operation. Accordingly, it is desirable for cooling tower that are efficient in both in the heat exchange properties and assembly. The present invention addresses this desire.
Therefore it would desirous to have an economical, mechanical draft, modular cooling tower that is efficient not only in its heat exchange properties but also in its time required for assembly and cost for doing the same.
SUMMARY OF THE INVENTIONEmbodiments of the present invention advantageously provides for a fluid, usually steam and method for a modular mechanical draft cooling tower for condensing said steam.
An embodiment of the invention includes a method for assembling a modular air cooled condenser extending along a vertical axis away from horizontal, comprising the steps of: assembling a first condenser bundle assembly having a first set of tubes having first and second ends, a steam manifold connected to the first ends of the tubes, and a condensate header connected to the second ends of the tubes; assembling a second condenser bundle having a second set of tubes having first and second ends, a steam manifold connected to the first ends of the tubes, and a condensate header connected to the second ends of the tubes; placing the first and second condenser bundle assemblies in to a container; transporting the container to a location upon which the modular air cooled condenser will be assembled; assembling a heat exchange delta by placing the first condenser bundle and the second condenser bundle; and positioning the heat exchange delta on a modular tower frame.
Another embodiment of the present invention includes a modular air cooled condenser extending along a vertical axis away from horizontal, comprising: means for assembling a first condenser bundle assembly having a first set of tubes having first and second ends, a steam manifold connected to the first ends of the tubes, and a condensate header connected to the second ends of the tubes; means for assembling a second condenser bundle assembly having a second set of tubes having first and second ends, a steam manifold connected to the first end of the tubes, and a condensate header connected to the second ends of the tubes; means for placing the first and second condenser bundle assemblies in to a container; means for transporting the container to a location upon which the modular air cooled condenser will be assembled; means for assembling a heat exchange delta by placing using the first condenser bundle and the second condenser bundle; and means for positioning the heat exchange delta on a modular tower frame.
Another embodiment of the present invention, A mechanical draft modular air cooled condenser that cools an industrial fluid is disclosed, comprising: a plenum with which at least one delta resides wherein said at least one delta comprises first condenser bundle having a first set of tubes having first and second ends, a steam manifold connected to the first ends of the tubes, and a condensate header connected to the second ends of the tubes; and a second condenser bundle having a second set of tubes having first and second ends, a steam manifold connected to the first ends of the tubes, and a condensate header connected to the second ends of the tubes; a support frame that supports said plenum; and a shroud that houses an air current generator.
In yet another embodiment of the present invention, a method for assembling a modular air cooled condenser extending along a vertical axis is disclosed, comprising: assembling a first condenser bundle having a first set of tubes having first and second ends and a condensate header connected to the second end of the tubes; assembling a second condenser bundle having a second set of tubes having first and second ends, and a condensate header connected to the second end of the tubes; placing the first and second condenser bundles in to a container; transporting the container to a location upon which the modular air cooled condenser will be assembled; assembling a heat exchange delta by placing using the first condenser bundle and the second condenser bundle; and positioning the heat exchange delta on a modular tower frame.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The above-mentioned and other features and advantages of this disclosure, and the manner of attaining them, will become more apparent and the disclosure itself will be better understood by reference to the following description of various embodiments of the disclosure taken in conjunction with the accompanying figures.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof and show by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice them, and it is to be understood that other embodiments may be utilized, and that structural, logical, processing, and electrical changes may be made. It should be appreciated that any list of materials or arrangements of elements is for example purposes only and is by no means intended to be exhaustive. The progression of processing steps described is an example; however, the sequence of steps is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps necessarily occurring in a certain order.
Embodiments described herein provide a heat exchange system, a support structure for an air cooled condenser (“ACC”), and a method of constructing a support structure for an ACC. As described herein, some or all of these embodiments provide substantial benefit over standard A-frame ACC. Examples of benefits over standard A-frame ACC include reduced cost of about 25%, improved constructability, higher annual output of power plant, improved cleanability due to use of motorized cleaning shuttlestandard, lower visual impact due to reduced height (26 m vs. 32.6 m) and reduced occupied ground area, and reduced foundations (40 columns vs 48 for A-frame ACC with equivalent output). This height reduction is due to the reduced height of the multi-deltas described herein compared to conventional A-Frame-type bundles that have longer tubes and increased overall height.
Specific examples of reduced cost and improved constructability include: Steam manifolds and steam condensate headers already welded on finned tube bundles in the manufacturing factory; Less total weight of steel structure (−25% vs A-Frame ACC); Less total weight of ducting (−25% vs A-Frame ACC); Reduced number of bundles (25% for A-Frame ACC); Fewer elements of steel structure to be assembled on site by bolting (−50% vs A-Frame ACC); Reduced site welding length on ducting (−50% vs A-frame ACC); Fewer lifting operations; Shorter construction duration; Fewer man activities at height due to more preassembly which results in improved overall safety level; Less scaffolding required; Higher proportion of piping and piping supports preassembled in the manufacturing factory on the finned tube bundles; Important proportion of assembly on site is at ground level (bolting of delta, liaison duct, . . . ); No cleaning ladder required; and More containerized deliveries.
Specific examples of higher annual output of power plant include: Lower back-pressure during low ambient temperature periods (e.g., below 9° C.) which results in higher power plant output during low temperature periods; and lower minimum back-pressure (62 mbar vs 70 mbar for A-Frame ACC) which results in higher power plant electricity production on a yearly basis (+0.4% vs A-Frame ACC). More particularly, the back-pressure may be reduced because the heat exchange tubes in the bundles (described herein) may be made shorter and more numerous in comparison to an A-Frame ACC. In this manner, the total surface area may be equivalent while the velocity in the tubes is reduced. It is yet another advantage that the reduced velocity results in a corresponding reduction in erosion of the tubing.
In use, the power plant 14 generates heat to create steam to drive turbines to generate power in a manner generally known to those skilled in the art. After steam has passed through the turbines, the steam still retains substantial waste heat which is removed by the heat exchange system 10 and the condensate is returned via the return line 36.
At
At
Turning now to
Turning now to
Turning now to
Each of the bundle assemblies 30 are assembled prior to shipping wherein each comprises a riser to header transition piece 202, steam manifold 204, finned tubes 206, and steam condensate headers 200. As can be seen in
Typically, turbine back pressure of an air cooled condenser or the like is limited by the maximum steam velocity in the tubes (to limit erosion) wherein the steam velocity is increasing with a decrease of back pressure (due to density of steam). Thus, due to the addition of tubes in accordance with the present invention, the steam is still maintained at the maximum allowable steam velocity but at a lower back pressure. The other limitation the current delta design addresses is that the pressure at the exit of the secondary bundles cannot be less than the vacuum group capability. This pressure typically results from turbine back pressure minus the pressure drop in ducting minus the pressure drop in the tubes. Accordingly, due to the reduced pressure drop in the tubes, the allowable turbine back pressure is lower with the delta 160 design.
Furthermore, the above-described bundle design also reduces the pressure drop within the individual delta 160. For example, the heat exchange that takes place via the deltas 160, is dependent upon the heat exchange coefficient, i.e., the mean temperature difference between air and steam and the exchange surface. Due to the reduced pressure drop as previously described, the mean pressure (average between inlet pressure and exit pressure) in the exchanger is higher with the design of the current condenser configuration 12. In other words, because steam is saturated, the mean steam temperature is also higher for the same heat exchange surface resulting in increased heat exchange.
Turning now to
Alternatively, the above described embodiments of the present employ tube bundles manufactured and assembled, prior to shipping, having steam manifold 204 and steam condensate headers 200, alternative embodiment bundles may not include a manifold prior to shipping. More specifically, in such embodiments, the tube bundles may be ship without steam manifolds 28 attached thereto. In said embodiments, the tube bundles 30 may be assembled in field to form the A-type configuration, as discussed above. However, instead of employing two steam manifolds, this alternative embodiment may employ a single steam manifold wherein the single steam manifold extends along the “apex” of the A configuration.
Referring now to
Next, the delta, generally indicated as 160, is assembled in the field as identified by numerals 216 and 218. As previously described, while the bundles may be positioned at any desired angle, they preferably are positioned at an angle (y) approximately twenty degrees (20°) to approximately thirty degrees (30°) from vertical and an angle (x) approximately sixty degrees) (60° to approximately seventy degrees (70°) from horizontal. More specifically, the bundles are positioned at twenty-six degrees (26°) from vertical and sixty-four degrees (64°) from horizontal. As designated by numeral 220, a single A-type delta is illustrated 160 formed by two bundle assemblies 30 to form the “A” configuration. The bundle assemblies 30 self support one another in this configuration.
Turning now to the air cooled condenser module 12 as referenced by the numeral 220, it is depicted employing five deltas 160. As discussed above, the air cooled condenser is an improvement over current air cooled condenser types and it has a high “pre-fabrication” level which equates to reduced installation cost and reduced installation time. Moreover, the above-described design reduces the pressure drop, thereby providing a more efficient heat exchange apparatus.
Tables 1 and 2 below show the number of parts utilized for a 32 module Multi-Delta and a 30 module A-Frame ACC designed for the same duty. There is a very dramatic decrease in pieces which translates in to substantially less construction labor and construction time.
As shown in Tables 1 and 2, the multidelta ACC of an embodiment disclosed herein includes less than half the parts of a comparable conventional A-Frame ACC (2125 parts verses 5148 parts). This reduction in part numbers has a corresponding reduction in labor costs, construction time, and the like.
The many features and advantages of the invention are apparent from the detailed specification, and, thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, for example a forced draft air cooled condenser has been illustrated but an induced draft design can be adapted to gain the same benefits and, accordingly, all suitable modifications and equivalents may be resorted to that fall within the scope of the invention.
Claims
1. A method for assembling an understructure for a modular air cooled condenser extending along a vertical axis away from horizontal, comprising the method steps of:
- preparing a foundation for a braced bay;
- placing the braced bay on the foundation;
- assembling a pre-constructed middle truss with a pre-constructed duct and risers;
- placing the assembled middle truss and duct on the braced bay;
- affixing a plurality of pre-constructed transversal structures to the braced bay;
- affixing a plurality of pre-constructed transversal trusses to the affixed transversal structures;
- affixing a plurality of pre-constructed longitudinal trusses to ends of the affixed transversal trusses; and
- affixing a plurality of pre-constructed bridges between ones of the affixed transversal trusses.
2. The method according to claim 1, further comprising the method step of:
- affixing a header to each respective riser.
3. The method according to claim 2, further comprising the method step of:
- affixing a top manifold to each respective header.
4. The method according to claim 3, further comprising the method step of:
- affixing four of the top manifolds to each respective header.
5. The method according to claim 4, further comprising the method step of:
- affixing a bundle to each respective top manifold.
6. The method according to claim 1, further comprising the method step of:
- fluidly connecting a return line to each bundle.
7. The method according to claim 6, further comprising the method step of:
- fluidly connecting the return line to a power plant.
8. The method according to claim 1, further comprising the method step of:
- fluidly connecting a main steam line to the duct.
9. The method according to claim 8, further comprising the method step of:
- fluidly connecting the main steam line to a power plant.
10. The method according to claim 1, further comprising the method step of:
- affixing a bell housing and a fan to the understructure.
11. A modular understructure for an air cooled condenser extending along a vertical axis away from horizontal, comprising:
- a braced bay disposed on a foundation;
- an assembled pre-constructed middle truss with a pre-constructed duct and risers disposed on the braced bay;
- a plurality of pre-constructed transversal structures affixed to the braced bay;
- a plurality of pre-constructed transversal trusses affixed to the affixed transversal structures;
- a plurality of pre-constructed longitudinal trusses affixed to ends of the transversal trusses; and
- a plurality of pre-constructed bridges affixed between ones of the transversal trusses.
12. The modular understructure according to claim 11, further comprising:
- a header affixed to each respective riser.
3. The modular understructure according to claim 12, further comprising the method step of:
- a top manifold affixed to each respective header.
14. The modular understructure according to claim 13, further comprising the method step of:
- four of the top manifolds affixed to each respective header.
15. The modular understructure according to claim 14, further comprising the method step of:
- a bundle affixed to each respective top manifold.
16. The modular understructure according to claim 11, further comprising the method step of:
- a return line fluidly connected to each bundle.
17. The modular understructure according to claim 16, further comprising the method step of:
- the return line fluidly connected to a power plant.
18. The modular understructure according to claim 11, further comprising the method step of:
- a main steam line fluidly connected to the duct.
19. The modular understructure according to claim 18, further comprising the method step of:
- the main steam line fluidly connected to a power plant.
20. The modular understructure according to claim 11, further comprising the method step of:
- a bell housing and a fan affixed to the understructure.
Type: Application
Filed: May 27, 2014
Publication Date: Dec 3, 2015
Inventors: Thomas Van Quickelberghe (Wannebecq), Francis Badin (Binche), Francois van Rechem (Brussels), Christophe Deleplanque (Brussels), Michel Vouche (Marbais)
Application Number: 14/287,922