The present disclosure relates generally to equipment enclosures, and particularly to enclosures surrounding power plant equipment.
Power generating equipment, such as gas turbines for example, may create significant amounts of acoustic energy (noise) during operation. Therefore it is common practice, as may be required by national agencies or the power station operators, to enclose such equipment within sound enclosures to dampen, or prevent transmission of, this acoustic energy into the surrounding environment. In addition to acoustic energy, many types of power generating equipment also generate large quantities of heat. When this equipment is sited indoors, a means to dissipate the heat to the exterior of the building and maintain specific thermal operating conditions may be required. Presently, enclosures utilize blowers to force cooling air through the enclosures to remove the heat generated by the equipment contained therein. Often, these are large blowers that may utilize motors from twenty to forty horsepower in size. These blowers may consume significant energy and require regular repair and maintenance, which may have a negative impact on the uptime of the generating equipment. Accordingly, there is a need in the art for an equipment enclosure arrangement that overcomes these drawbacks.
An embodiment of the invention includes an enclosure having a top and at least one side to surround equipment. A first set of ventilation ports is disposed toward the bottom of the enclosure, a second set of ventilation ports is disposed toward the top of the enclosure, and a baffle is disposed proximate the top at the interior of the enclosure. The top of the opening of the first set of ventilation ports is disposed to be lower than the bottom of the equipment, the bottom of the opening of the second set of ventilation ports is disposed to be higher than the top of the equipment, and the baffle is configured to direct a cooling medium toward the second set of ventilation ports.
Another embodiment of the invention includes a power plant system comprising generating equipment. The generating equipment includes a generator, which is mechanically driven by a gas turbine or a steam turbine. The gas turbine comprises an inlet plenum, and an exhaust diffuser. The power plant system includes an enclosure enclosing at least one of the generator, the gas turbine, the steam turbine, the inlet plenum, and the exhaust diffuser, or any combination of the foregoing. The enclosure includes a top and at least one side to surround the equipment. A first set of ventilation ports is disposed toward the bottom of the enclosure, a second set of ventilation ports is disposed toward the top of the enclosure, and a baffle is disposed toward the top at the interior of the enclosure. The top of the opening of the first set of ventilation ports is disposed to be lower than the bottom of the equipment, the bottom of the opening of the second set of ventilation ports is disposed to be higher than the top of the equipment, and the baffle is configured to direct a cooling medium toward the second set of ventilation ports.
Referring to the exemplary drawings wherein like elements are numbered alike in the accompanying Figures:
An embodiment of the invention provides a naturally ventilated power plant equipment enclosure, employing natural convection as opposed to forced convection. The enclosure is designed to limit the transmission of acoustic energy generated by the equipment, while maintaining appropriate thermal conditions for operation of the equipment. In an embodiment, the enclosure includes ventilation inlets near the enclosure bottom and ventilation outlets near the enclosure top. The inlets may be located on or near the floor or at or near the bottom of the enclosure sidewalls. The outlets may be positioned on the enclosure roof or near the top of the enclosure sidewalls. In an embodiment, outlets may be located on the top of a pitched roof to drive maximum buoyancy flow through the enclosure. If outlets are not disposed on the enclosure top, due to an obstruction for example, or for reasons relating to the desire to use the enclosure top as a storage area, for example, ventilation outlets may be positioned on the enclosure sidewalls.
Baffles, or any airflow management member suitable for directing a cooling medium, such as air, may be used to increase buoyancy flow, divert the ventilation airflow, and improve natural ventilation through the enclosure to uniformly cool the equipment. Baffle quantity and arrangement will depend on the number and location of outlets.
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The sides 105 and top 110 are constructed of suitable materials configured to minimize, or at least reduce, the transmission of acoustic energy (noise) generated by operation of the equipment. In an exemplary embodiment, the sides 105 and top 110 may be configured to limit the transmission of acoustic energy to a maximum sound pressure level of 74 dbA (decibel A-weighted). Sound pressure level limits may vary, and may be set by equipment operators, local, and national authorities. Alternate embodiments may be configured to meet the variation of sound pressure level limits required.
While an embodiment has been described depicting three inlets 115 on side walls 105, it will be appreciated that scope of the invention is not so limited, and that the invention will also apply to enclosures 100 with different numbers of inlets 115, such as one, two, three, four, or more, that may be disposed on one or more sides 105 of the enclosure. Further, an embodiment of the invention may allow the inlets 115 to be disposed on the bottom of the enclosure 100. While an embodiment has been described depicting three outlets 120 along the center of the top 110, it will be appreciated that the scope of the invention is not so limited, and that it will also apply to enclosures 100 having different numbers of outlets 120 arranged along the top 110, such as one, two, three, four, or more. While the exemplary embodiment has been described depicting one access port 142 through a side 105, it will be appreciated that the scope of the invention is not so limited, and that it will apply to enclosures 100 having various numbers and configurations of access ports 142 as may be required, for example, through the sides 105, top 110, or bottom to provide mechanical, fuel, electrical, exhaust, and thermal connections between the equipment and the surrounding environment.
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In addition to restricting the acoustic energy transmitted by the equipment 175 to the external environment, an embodiment of the enclosure 100 is also configured to maintain appropriate thermal conditions, which may be necessary for proper equipment operation, or may be health-based requirements, set by the appropriate authorities. In an exemplary embodiment, where the enclosure 100 is used to enclose an exemplary turbine exhaust plenum/diffuser 175, the gasses flowing through the exhaust plenum/diffuser 175 may reach temperatures of 1100 degrees Fahrenheit (593 degrees Celsius). In an exemplary embodiment, proper thermal management may require a maximum internal enclosure 100 temperature of 140 degrees Fahrenheit (60 degrees Celsius). Further, an exemplary exhaust plenum/diffuser may require a temperature differential less than or equal to 25 degrees Fahrenheit (14 degrees Celsius) between a top 161 center and a bottom 156 center location of the equipment 175.
As a cooling medium, such as air currents depicted by wavy lines 200, enters the enclosure 100 via the inlets 115, heat generated by the equipment 175 is transferred to the surrounding internal ambient air 200, causing it to expand, become less dense, and rise, until it exits via the outlets 120. In an embodiment of the enclosure 100, the number and size of inlets 115 and outlets 120 will be determined by the thermal and acoustic properties of the equipment 175. Increased heat generation typically results in requiring an increase in total inlet 115 and outlet 120 area. However, if the size of inlets 115 and outlets 120 become too large, the ability of the enclosure 100 to restrict transmission of acoustic energy may be reduced.
As a result of the expansion of the air 200, the volume flow rate of air 200 leaving the enclosure 100 from the outlets 120 is greater than the volume flow rate of air 200 entering via the inlets 115. A ventilation area shall be defined by the size of the ventilation ports 115, 120. Accordingly, to prevent a possible flow restriction, an embodiment of the invention has a first ventilation area of the inlets 115 equal to or less than a second ventilation area of the outlets 120. In an embodiment, the ratio of the second ventilation area to the first ventilation area may range from 1.1 to 1.5 depending upon the specific thermal characteristics of the embodiment. It is contemplated that a ratio of 1.1 to 1.5 will provide sufficient heat transfer while limiting the outlet opening for noise control.
In an embodiment, the inlets 115 are sized and disposed so as to direct incoming air 200 to the bottom 156 center location of the equipment 175. In an embodiment, the top of the opening of the inlet 115 is located lower than the bottom 156 of the equipment 175, as indicated by dimension 155. The actual distance represented by dimension 155 may vary depending upon such factors as inlet 115 and outlet 120 size, and enclosure 100 thermal properties, for example. Similarly, in order to best utilize a “chimney” effect created by the buoyancy of the heated air 200, an embodiment has the bottom of the opening of the outlets 120 located higher than the top 161 of the equipment 175, as indicated by dimension 160. The actual distance represented by dimension 160 may vary depending upon such factors as inlet 110 and outlet 120 size, and enclosure 100 thermal properties, for example.
As may be validated by Computational Fluid Dynamics (CFD) Software, a baffle 150 may be used to direct a cooling medium such as air, maximize air stream velocity, and prevent localized areas of increased temperature. In an embodiment, as depicted in
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The baffle 151 will accelerate heated air 200 towards the outlets 120 on the opposite side 105. This will increase airflow over the top 161 of the equipment 175, the equipment 175 will be uniformly cooled, and hotspots or dead/recirculation zones inside the enclosure 100 will be eliminated or substantially reduced. In an exemplary embodiment, the baffle 151 is disposed such that an angle θ formed between the baffle and the side 106 is about 45 degrees. As used herein, the term “about” represents deviation that may result from optimizing the particular enclosure 100 to the thermal or geometric characteristics that may be required for operation of the particular equipment 175 contained therein. Further, to properly direct airflow, maximize air stream velocity, and prevent localized areas of increased temperature, it is contemplated that the smallest distance (represented by reference numeral 165) from the baffle 151 to the equipment 175 will be equal to or less than the smallest distance (represented by reference numeral 170) from the equipment to the interior of the side 106.
As described above in reference to
As disclosed, some embodiments of the invention may include some of the following advantages: ability to eliminate blower use for heat removal; ability to eliminate, or at least reduce, blower noise, which can contribute to overall power plant noise levels, thereby reducing overall system noise; increased equipment uptime by eliminating blower maintenance; reduced energy consumption via elimination of blower use; and, reduction in space consumed by blower motors and fans.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.