Turbine intercooler   

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates generally to intercoolers and, more particularly, intercoolers with a set of conducting members disposed in a flow path of compressed gaseous fluid.

2. Discussion of the Prior Art

Intercoolers in turbines are provided to cool air that is compressed in the low pressure compressor before it is channeled to the high pressure compressor. In their conventional structures, intercoolers experience degradation in internal areas that are difficult to access for maintenance or replacement. Thus, intercoolers with an alternative structure that is easier to maintain or fix, and is more efficient, would be desirable.

The following summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

In accordance with one aspect, the present invention provides an intercooler including a shell with an inlet and an outlet. The shell defines a first chamber. The intercooler further includes a plurality of elongate conducting members. Each of the conducting members includes a first end section and a second end section and is disposed such that each of the first end sections is inside the first chamber of the shell and such that each of the second end sections is disposed exteriorly of the shell. Each of the second end sections is disposed in a flow path of at least one cooling medium so as to undergo evaporative cooling.

In accordance with another aspect, the present invention provides an intercooler including a shell defining a first chamber and a plurality of elongate conducting members. Each of the conducting members includes a first end section and a second end section and is disposed such that each of the first end sections is inside the first chamber of the shell and such that each of the second end sections converges toward one another. Each of the second end sections is disposed in a flow path of at least one cooling medium so as to undergo evaporative cooling.

In accordance with yet another aspect, the present invention provides a method of cooling compressed gaseous fluid including the steps of disposing each of first end sections of a plurality of elongate conducting members in a flow path of compressed gaseous fluid such that heat from the compressed gaseous fluid is transferred toward second end sections of the conducting members by way of conduction, disposing each of second end sections of the conducting members in a flow path of at least one cooling medium, and generating a flow of the at least one cooling medium moving toward the second end sections such that heat from the second end sections is transferred to the cooling medium.

The foregoing and other aspects of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic view of a part of a turbo machine;

FIG. 2 shows a first example embodiment of an intercooler;

FIG. 3 shows a variation of the first example embodiment of the intercooler;

FIG. 4 shows a second example embodiment of the intercooler;

FIG. 5 shows a first example of fins formed on conducting members;

FIG. 6 shows a second example of fins formed on the conducting members; and

FIG. 7 shows an example of an arrangement pattern of the conducting members.

FIG. 8 shows an example of an alternative embodiment of the conducting members.

DETAILED DESCRIPTION

Examples of embodiments that incorporate one or more aspects of the present invention are described and illustrated in the drawings. These illustrated examples are not intended to be a limitation on the present invention. For example, one or more aspects of the present invention can be utilized in other embodiments and even other types of devices.

Turning to the shown example of FIG. 1, a schematic of a turbo machine, such as a gas turbine engine, is illustrated partially and shows an intercooler 10, a low-pressure compressor 12 (LPC), and a high-pressure compressor 14 (HPC). Fluid 11 that is compressed at the LPC 12 is channeled to the intercooler 10 where the temperature of the compressed gaseous fluid 11 is lowered prior to being channeled downstream to the HPC 14.

FIGS. 2 and 3 show variations of a first example embodiment of the intercooler 10 in a schematic fashion. The intercooler 10 includes a shell 16 and a cooler 18. The shell 16 includes an inlet 16a in fluid communication with the LPC 12 and an outlet 16b in fluid communication with the HPC 14. The shell 16 forms a first chamber 20 in fluid communication with the LPC 12 and the HPC 14 such that compressed gaseous fluid 11 is channeled through the first chamber 20. The cooler 18 may include a casing 22 forming a peripheral wall defining a second chamber 24 in which various features for providing cooling are located as will be described below.

As shown in FIGS. 2 and 3, the shell 16 and the cooler 18 are connected by a plurality of elongate conducting members 26 each of which include a first end section 26a and a second end section 26b. The conducting members 26 may be cylindrical, pipe-like structures and are sufficiently elongate to connect the shell 16 and the cooler 18 such that the first end section 26a is disposed in the first chamber 20 of the shell 16 and a second end section 26b is disposed in the second chamber 24 of the cooler 18. The elongate conducting members 26 may be formed of metals that are sufficiently conductive so that the first end section 26a can draw heat from gas in the shell 16 and transmit such heat to the second end section 26b that can be cooled inside the cooler 18. For example, the conducting members 26 may be made of copper, stainless steel, carbon steel, or other metals or alloys. In yet another example, the conducting members 26 may be superconductive and examples of such superconducting members may be found in U.S. Pat. Nos. 6,132,823, 6,811,720, 6,911,231, and 6,916,430.

The arrangement of the conducting members 26 inside the first chamber 20 is such that highly efficient heat transfer can occur longitudinally about the conducting members 26 and such that pressure drop in the first chamber 20 is small thereby improving turbine efficiency.

In the embodiments of FIGS. 2 and 3, the second end sections 26b may be disposed in a path of a cooling medium to accomplish cooling. As such, the second chamber 24 of the cooler 18 may include a discharger 28 which releases as one cooling medium a cooling liquid 35 (e.g., water) toward the second end sections 26b although the released cooling liquid 35 may or may not contact the second end sections after discharge. In one example, the discharger 28 may be embodied as a spray that releases a cooling liquid 35 from an elevated area within the cooler 18 as shown in FIGS. 2-3. Additionally, the second end sections 26b may be embedded inside a wick element 30 which is disposed underneath the discharger 28 so as to absorb and retain some of the cooling liquid 35 by capillary action. The wick element 30 may be formed of various materials that are durable, non-dissolving material capable of wicking action via surface tension, retaining water, and capable of allowing evaporation of water retained in the wick when exposed to flowing gas. For example, the wick element 30 may be embodied as a sponge or a bundle of woven fibers or plastics that is capable of retaining the cooling fluid by capillary action and that is sufficiently dimensioned such that a bulk of the second end sections 26b can be embedded therein. The cooling liquid 35 retained by the wick element 30 is kept in proximity with the second end sections 26b for a longer period of time rather than simply passing by the conducting members 26 such that the time during which heat transfer can occur is prolonged.

Additionally, the cooler 18 may include a blower 32, such as an axial fan, a centrifugal fan, or an air suction device, that generates a movement of air 33 across the conducting members 26 or the wick element 30 thereby placing the conducting members 26 in a flow path of another cooling medium. In the embodiment shown in FIGS. 2-3, movement of air 33 is in an upward direction within the cooler 18 although the flow path of the air 33 may vary. In these embodiments, the casing 22 of the cooler 18 is configured with openings 34 formed by louvers near the base to allow ambient air to refill the gap left by the air that has moved out of the second chamber 24 of the cooler 18. The openings 34 may include a filter to guard against contaminants in ambient air from entering the cooler 18. The blower 32 may be located at a top of the cooler 18 which may also include a vent 36 which may be covered by a grille or filter near the blower 32.

Moreover, a container 38 may be disposed at a base of the cooler 18 to recover cooling liquid 35 that falls from the discharger 28 and is not retained by the wick element 30. Furthermore, the recovered cooling liquid 35 may be rerouted to the discharger 28 via a recirculation system 40, which may include a pump 45, to be thereafter released again from the discharger 28. The recirculation system 40 may include a control system 42 for controlling the circulation of cooling fluid 35 back to the discharger 28 or adapting the supply of cooling fluid 35 depending on atmospheric conditions. The control system 42 may adjust the recirculation system 40 in response to operating conditions, such as modifying the degree of cooling or the volume flow of the re-circulated cooling liquid 35 depending on a number of conditions such as ambient temperature of the environment in which the intercooler 10 is located. The cooling liquid 35 which has absorbed heat from the conducting members 26 while falling from the discharger 28 may be cooled by counter flow of air 33 generated by the blower 32. Moreover, the blower 32 can generate evaporation of the cooling liquid 35 (e.g., water) captured in the wick element 30 such that the conducting members 26 are cooled by the latent heat property of the cooling liquid 35. The recirculation system 40 may include a filter to guard against contaminants in the cooling liquid 35 from moving through the recirculation system 40. Without the recirculation system 40, the discharger 28 may simply be connected to a source of the cooling liquid 35 and the container 38 may simply lead to a drainage system.

Some of the second end sections 26b or some parts of the second end sections 26b may be disposed outside the wick element 30 and may experience only forced convective cooling through air flow generated by the blower 32 but not evaporative cooling.

The casing 22 of the cooler 18 may be embodied in a variety of shapes and arrangements. For example, the casing 22 may be oriented upright and be shaped like a box, a cylinder, frustocone, etc. If the cooler 18 is a substantially upright and cylindrical structure, the cooler 18 may be described as a tower cooler 18a. The shell 16 may also be embodied in a variety of shapes and arrangements. For example, the shell 16 may be oriented in a substantially upright (FIG. 2) or horizontal (FIGS. 3 and 4) manner and may be shaped like a box, a cylinder (FIGS. 2 and 3), a ring (FIG. 4), etc. It may be possible to reduce an area occupied by a footing of the intercooler 10 with a vertical arrangement of the shell 16 and the cooler 18 as shown in FIG. 2. Moreover, the arrangement of the shell 16 relative to the cooler 18 may affect the number of conducting members 26 that connect the two. Specifically, if the conducting members 26 are straight, the conducting members 26 may only be disposed in a limited area where parts of the shell 16 and the cooler 18 are immediately and laterally adjacent. However, it may be possible to modify the shape of the conducting members 26 and provide conducting members 26 connecting the shell 16 and the cooler 18 even if an area where parts of the shell 16 and the cooler 18 are immediately and laterally adjacent is small.

In an alternative embodiment of FIG. 4, the shell 16 is arranged to surround or substantially encircle the tower cooler 18a with the inlet and the outlet disposed in one radial direction about the tower cooler 18a. The conducting members 26 that extend from the first chamber 20 of the shell 16 to the interior of the cooler are disposed in a plurality of radial directions with respect to the tower cooler 18a such that the first end sections 26a are in the flow path of the compressed gaseous fluid 11 and the second end sections 26b are in the path of at least one cooling medium. Several features shown in the cooler of FIGS. 2-3 are omitted from FIG. 4 in order to illustrate the arrangement of the conducting members 26. Thus, the tower cooler of FIG. 4 may include the blower, the filter, the wick element, the container, the recirculation system, the heat exchanger or other features similarly as shown in FIGS. 2-3.

FIGS. 5 and 6 show example embodiments of the conducting members 26. A cross-section of the conducting members 26 may be circular such that a fluid passing by the conducting members 26 can undergo a more streamlined flow and be evenly distributed in the spaces between the conducting members 26. In order to enhance heat exchange, the first end sections 26a or the second end sections 26b may be configured with fins 44, as shown in FIGS. 5 and 6, which may be provided at regular intervals along a longitudinal axis of the conducting members 26. The fins 44 may be provided longitudinally throughout the conducting members 26 or may be provided within a longitudinal portion of the conducting members 26. For example, the fins 44 may be provided only on the first end sections 26a. The fins 44 are provided to increase surface areas on which heat exchange can occur between the conducting members 26 and the cooling medium as the air 33 moves in between the fins 44. The longitudinal spacing between the fins 44 is not drawn to scale and the fins 44 may be located closer to or apart from one another than the embodiments shown in FIG. 5 or 6 in order to alter a heat transfer coefficient at the end sections 26a, 26b of the conducting members 26. For example, the fins 44 may be located so close to one another as to provide a gap that is smaller than the thickness of the fins 44. As shown in the embodiments of FIGS. 5-6, the fins 44 may be embodied as circular flanges 44a, rectangular flanges 44b or other polygonal or irregular shapes but may also be embodied in a variety of geometries affecting heat transfer efficiency. For example, the rectangular flanges 44b may be slightly bent at the corners toward the two longitudinal ends of the conducting members 26 and the directions in which the corners are bent may alternate as shown in FIG. 6.

Because a plurality of conducting members 26 is disposed in the intercooler 10, a pattern in which the conducting members 26 are arranged may also affect a heat transfer coefficient between the cooling medium and the conducting members 26. FIG. 7 partially shows a flow path of the compressed gaseous fluid 11 through an arrangement of the conducting members 26 in which the first end sections 26a are configured with fins 44a. In a pattern where all of the conducting members 26 are parallel to one another, as shown in FIG. 7, the pattern may be divided into a plurality of subsets 46 of conducting members 26 that are parallel and vertically aligned. In the pattern of FIG. 7, although each subset 46 includes conducting members 26 that are parallel and vertically aligned, two neighboring subsets 46 are misaligned or staggered horizontally about one another such that the flow path of the cooling medium encounters a greater number of conducting members 26, compared to a pattern in which neighboring subsets 46 are also horizontally aligned, thereby generating increased heat exchange between the compressed gaseous fluid 11 and the first end sections 26a. Such horizontal misalignment between neighboring subsets 46 can also be implemented to the embodiment of FIG. 4 even if all of the conducting members 26 are not parallel to one another due to the radial arrangement of the subsets 46. Similarly, in such a configuration, the subsets 46 would include parallel and vertically aligned conducting members 26 but neighboring subsets 46 would be horizontally misaligned.

The intercooler 10 described herein provides an apparatus for removing heat from compressed gaseous fluid 11 traveling from the LPC to the HPC. The first end sections 26a of the conducting members 26 take away heat from the compressed gaseous fluid 11 and transmit the heat to the second end sections 26b. The first end sections 26a may be configured with fins 44 to enhance heat exchange between the compressed gaseous fluid 11 and the first end sections 26a. The second end sections 26b can be disposed in a flow path of one or more cooling medium (e.g., cooling liquid 35 and/or air 33) to enhance heat loss from the second end sections 26b to the atmosphere. By providing the second end sections 26b in the wick element 30, the cooling liquid 35 can be cooled by convective cooling (i.e., the upward movement of air 33 generated by the blower 32 in counter flow with downwardly falling cooling liquid 35) or the evaporative cooling (i.e., gasification of the cooling liquid 35 taking away heat from neighboring cooling liquid 35 in the wick element 30). In case of the cooling liquid 35, the cooling liquid 35 can be recovered after being released toward the second end sections 26b and re-circulated for cooling prior to being released again toward the second end sections 26b.

In the embodiment of FIG. 4, the donut-shaped shell 16 substantially encircling the tower cooler 18a allows the compressed gaseous fluid 11 to move smoothly therethrough without facing obstructions such that the compressed gaseous fluid 11 experiences a low pressure drop and the overall efficiency of the gas turbine is improved. Other shell shapes, e.g. U-shape, providing smooth curving path for the air flow yield similar benefit of low pressure drop.

FIG. 8 shows an alternative embodiment of the conducting members 26. FIG. 8 only shows one of the first end section 26a or the second end section 26b of the conducting members 26 but the same configuration can be implemented on the other end section. In this embodiment, each end of the plurality of the conducting members 26 includes submembers 50 which are finned similarly to FIGS. 5-6. The submembers 50 transition to a header 52 which includes transition sections 54 at each end and a bundled section therebetween 56. The transition sections 54 and the submembers 50 are located inside the shell 16 or the casing 22 while the bundled section 56 extends through the shell 16 or the casing 22 thus reducing the number of holes formed on the shell 16 or the casing 22 to one.

The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Example embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.