Air cooled condenser fogging control system   

Abstract: Certain embodiments of the invention may include systems, methods, and apparatus for controlling turbine steam output. According to an example embodiment of the invention, a method is provided for controlling steam turbine output. The method can include measuring one or more temperatures or back pressures associated with one or more cells associated with a turbine cooling condenser and controlling temperature distribution of the one or more cells in response, at least in part, to the measured one or more temperatures or back pressures.

FIELD OF THE INVENTION

This invention generally relates to gas turbines, and more particularly relates to controlling turbine steam output.

BACKGROUND OF THE INVENTION

Typical industrial gas turbine systems utilize heat recovery steam generators (HRSG) to recover energy that may otherwise be wasted as heat. For example, hot exhaust gases produced by the gas turbine can be directed to the HRSG, where the exhaust heat converts water into steam. The steam, in turn, can be used to drive a steam turbine to produce additional usable power, such as electrical power. After the steam has traversed the turbine, condensers can be used to cool the steam and return it to a liquid state for use again by the HRSG. Removing heat from the steam quickly helps reduce backpressure in the downstream steam path of the turbine, and increases the efficiency of the system.

Condensers can include a number of cooling tubes and/or fin tube bundles that act as heat exchangers for the steam. Ambient air, forced air, or water-cooled condensers are typically used to reduce the steam temperature. For example, when cool air or water is forced across the fin tubes, heat is exchanged from the hot steam inside the condensers to the external air or water. However, forced-air condensers require extra energy for fans to blow air across the cooling fin tubes.

SUMMARY

Some or all of the above needs may be addressed by certain embodiments of the invention. Certain embodiments of the invention may include systems, methods, and apparatus for controlling turbine steam output.

According to an example embodiment of the invention, a method is provided for controlling steam turbine output. The method can include measuring one or more temperatures or back pressures associated with one or more cells associated with a turbine cooling condenser, and controlling temperature distribution of the or more cells in response, at least in part, to the measured one or more temperatures or back pressures.

According to another example embodiment, a system is provided for controlling steam turbine output. The system may include a heat recovery steam generator, a steam turbine associated with the heat recovery steam generator, and one or more condensers associated with the steam turbine. The one or more condensers may include one or more cells. The system may also include one or more sensors for measuring one or more temperature or back pressures of one or more cells, one or more valves for directing steam to the one or more cells, one or more nozzles for introducing coolant towards the one or more cells, one or more fans for forcing air and coolant past and around the one or more cells, and at least one processor configured to execute computer-executable instructions for controlling temperature distribution of the or more cells in response, at least in part, to the to the measured one or more temperatures or back pressures.

According to another example embodiment, an apparatus is provided for controlling steam turbine output. The apparatus may include one or more condensers associated with the steam turbine. The one or more condensers may include one or more cells. The apparatus may also include one or more sensors for measuring one or more temperatures or back pressures of one or more cells. The apparatus may also include one or more valves for directing steam to the one or more cells; one or more nozzles for introducing coolant towards the one or more cells; one or more fans for forcing air and coolant towards the one or more cells; and at least one processor configured to execute computer-executable instructions for controlling temperature distribution of the or more cells in response, at least in part, to the measured one or more temperatures or back pressures.

Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed inventions. Other embodiments and aspects can be understood with reference to the following detailed description, accompanying drawings, and claims.

Reference will now be made to the accompanying tables and drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 is a block diagram of an illustrative turbine and cooling system, according to an example embodiment of the invention.

FIG. 2 depicts an illustrative condenser cooling system, according to an example embodiment of the invention.

FIG. 3 is a block diagram of an illustrative cooling control system, according to an example embodiment of the invention.

FIG. 4 is a block diagram of an illustrative cooling system, according to an example embodiment of the invention.

FIG. 5 is a block diagram of an illustrative cooling system with an alternate header arrangement, according to an example embodiment of the invention.

FIG. 6 is a block diagram of an illustrative cooling system with dual cooling path configuration, according to an example embodiment of the invention.

FIG. 7 is a flow diagram of an example method according to an example embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

Certain embodiments of the invention may enable steam output associated with a heat recovery steam generator to be controlled. According to certain example embodiments, forced air and/or fogging coolant may be directed to condenser banks and selectively activated to control a temperature distribution of the condenser cooling system.

Various fans, valves, pumps, nozzles, and controllers may be utilized for controlling the forced air and/or coolant, according to example embodiments of the invention, and will now be described with reference to the accompanying figures.

FIG. 1 depicts a turbine and cooling system 100, according to an example embodiment of the invention. In an example embodiment, fuel 102 may be combusted to power a turbine 104. Part of the rotational energy produced by the turbine 104 may be utilized, at least in part, to drive a compressor 106 and a generator 108. In an example embodiment, electricity from the generator 108 may be supplied to a power grid 112 via a transformer 110. In an example embodiment, the generator 108 may be cooled by a cooling skid 114. In an example embodiment, an additional cooling skid 116 may be utilized to cool lube oil associated with the turbine 104 and the compressor 106.

According to an example embodiment, hot exhaust gas 118 from the turbine 104 may be directed to a heat recovery steam generator (HRSG) 120 and steam turbine 122 to extract and convert the heat energy from the exhaust to rotational energy that can be utilized to drive an additional generator, for example. According to an example embodiment, cooling water 140 may be converted to steam via the HRSG 120, and the resulting steam pressure may be harnessed to drive the steam turbine 122. In an example embodiment, after the steam has traversed the steam turbine 122, it may have lower energy content and may be considered lower quality steam 124. Therefore, according to an example embodiment, a condenser 126 may be utilized to cool and condense the low quality steam 124 to help reduce the backpressure from the steam turbine 122.

In accordance with an example embodiment, the turbine and cooling system 100 may include supporting structures, steam ducting from the steam turbine interface, auxiliaries such as the condensate and drain pumps, condensate and duct drain tanks, air evacuation units, and related piping works and instrumentation.

According to example embodiments of the invention, spraying water mist or fogging 134 towards and around the condensers 126 may reduce the ambient air temperature via an evaporation process. The lower ambient air temperature may lower the temperature of the air stream. Such a reduction in temperature of air may internally lower the temperature of the water and steam flowing in the cooling tubes via heat exchange as the cooler air blows across the air-cooled condenser cooling tubes.

According to an example embodiment of the invention, one or more condensers 126 sections may be selectively cooled via fogging skids 126. In an example embodiment, the fogging skids 126 may include pumps and fans. According to an example embodiment, one or more condenser 126 regions, zones, or sections may be selectively cooled with ambient or forced air 132. In another example embodiment of the invention, the one or more condensers 126 may be selectively cooled with fogging 134 in addition to the ambient or forced air 132. In an example embodiment, fogging coolant may include aerosolized water that is sprayed through fogging nozzles or nozzle arrays. In an example embodiment, the heat from the condenser 126 may be exchanged with the ambient or forced air 132 with fogging 134 resulting in heat 136 being released from the condenser 126 and the low quality team 124 condensing to water 140 for recycling through the HRSG 120.

According to an example embodiment of the invention a fogging spray pattern may be optimized for maximizing cooling impact on the condenser. According to an example embodiment of the invention a fogging spray pattern may be optimized for minimizing water usage. In accordance with example embodiments of the invention, the wind direction may be monitored and used to control the fogging spray nozzle array 130 to minimize wastage of water and maximize cooling. In an example embodiment, forced air and/or the fogging spray pattern 134 may be based on localized temperature readings from the cooling tower condensate tubes. For example, tubes that run hotter may receive greater percentages of forced air and/or spray of water.

According to an example embodiment, coolant, such as water, may be selectively directed to certain fogging nozzles 130 needed to control the cooling distribution of the condenser 126 zones or sections. Furthermore, in an example embodiment, the forced air fan speeds may be controlled or adjusted by zone. According to an example embodiment, the flow of steam may be selectively directed through certain condenser banks and cooled as needed to reduce the parasitic load of the fans and/or to conserve fogging water.

FIG. 2 depicts a plan view of a condenser cooling system 200, according to an example embodiment of the invention. In an example embodiment, steam 202 may enter the condenser piping 206 and may be directed to cooling cells 207. In an example embodiment, after the steam is cooled, and condensed, it may be directed to a hot well by a condenser return 204. According to an example embodiment, the steam from the turbine 202 may be selectively directed towards certain cooling cell banks or rows by one or more valves 214. The valves 214 may control the flow of the steam to banks or rows of cooling cells 207, and the steam may flow through the individual condenser piping 206. In an example embodiment, the cooling cells 207 may include fans and condensers 212.

According to an example embodiment, the condenser piping 206 may direct the steam 202 to condensers 212, where cooling air and/or fogging coolant may be utilized to exchange heat with the steam to condense it to a liquid. The liquid may then be recycled via a condenser return to a hot well 204.

In certain example embodiments of the invention, the condenser cooling system 200 may include multiple condensers 212 and associated cooling cells 207. In an example embodiment, the various cooling cells 207 in the condenser cooling system 200 may have different temperatures, depending on factors such as wind direction, fan speed, coolant, humidity, nearby heat sources, etc. For example, certain cells may run cooler due to their proximity to the perimeter of the system. For example, FIG. 2 indicates a lower temperature cell 208 in the corner of the system 200, a mid temperature cell 210 along a side of a row of cells, and example higher temperature cells 212 towards the middle of the system 200. In example embodiments, many other temperature distributions may occur due to the factors mentioned above, and other factors.

According to an example embodiment, steam 202 may be selectively directed to certain cells or rows of cells. In certain example embodiments, directing the steam 202 to certain rows of cells may allow maintenance or repair to be carried out in certain condenser cells, while other cells of the condenser cooling system 200 may still be operational. In other example embodiments, directing the steam 202 to certain rows of cells may facilitate a more efficient cooling of the steam 202. For example, if the HRSG is operating at less than full capacity, it may be more cost effective to activate only certain rows of condenser cells to reduce parasitic power, wear and tear on fans, and/or to conserve fogging coolant.

In an example embodiment of the invention, the temperature of the individual cooling cells 207 may be measured by one or more temperature sensors. In an example embodiment, the operation of the condenser cooling system 200 may be based, at least in part, on the measured temperatures of the cooling cells. According to an example embodiment, the speed of individual cooling fans may be controlled based on the measured temperatures to direct more cool air towards the cells that need a higher level of heat transfer. In an example embodiment, fogging spray may be selectively controlled based on measured cell temperature, wind direction, humidity etc. to further provide efficient and selective cooling of the cells 207.

According to example embodiments of the invention, controlling the temperature distribution of the cooling cells 207 may include selectively directing steam through the one or more cells 207. In an example embodiment, controlling the temperature distribution may include selectively introducing coolant towards the one or more cells 207 such that heat from the steam is transferred by the one or more cells 207 to the coolant. According to an example embodiment, selectively introducing the coolant may include manipulating one or more nozzles (such as 130 in FIG. 1) in response to one or more of: temperature, humidity, back pressure, ambient wind direction, zonal temperature distribution, steam flow, parasitic load balance, or power demand.

According to an example embodiment, controlling the temperature distribution of the one or more cooling cells 207 may include selectively forcing air towards the one or more cells 207. According to an example embodiment, heat from the steam may be transferred from the one or more cells 207 to the forced air. In an example embodiment, selectively forcing air may include selectively manipulating one or more fans in response to one or more of: temperature, humidity, backpressure, ambient wind direction, zonal temperature distribution, steam flow, parasitic load balance, or power demand. According to an example embodiment, cooling of the one or more cooling cells 207 may further include selectively introducing coolant towards the one or more condensers wherein heat from the steam may be transferred by the one or more cells (207) to one or more of the coolant, the forced air, or air-entrained coolant.

According to example embodiments of the invention, the steam turbine output may be controlled at least in part by measuring one or more temperature associated with the condensers cells, and/or by measuring the cooling air exit temperature from the air cooled condensers. In an example embodiment, temperature may be measured at or near the steam header (condenser tube inlet) and at or near the exit condensate header (steam discharge) of a particular cell. According to an example embodiment, if there is not sufficient temperature differential between these two measurements, then that particular cell may be sprayed with water or fogging coolant to increase the temperature differential. According to an example embodiment, an increase in vacuum and/or reduction in back pressure may result from the cooling of the cell. According to an example embodiment, vacuum and/or back pressure measurements may be utilized in place of, or in conjunction with temperature differential measurements to determine the appropriate action for directing fog coolant towards a particular condenser cell. In an example embodiment, increasing the heat rejection capability of the condenser by spraying fogging coolant on the cell may facilitate conditions for creating more output from the steam turbine.

FIG. 3 depicts a cooling control system 300, according to an example embodiment of the invention. According to an example embodiment of the invention, the cooling control system may include a controller 302, which may include a memory 304, one or more processors 306, one or more input/output interfaces 308, and/or one or more network interfaces 310. According to an example embodiment, the memory 304 may include an operating system 312, data 314, and one or more control modules 318. In an example embodiment, the one or more control modules 318 may include specialized computer executable code for processing inputs, stored data 314, and for directing certain data for output or control.

According to an example embodiment of the invention, the cooling control system 300 may receive information from, send information to, and interact with various valves, pumps, and sensors 320, the a turbine and steam system (such as 100 in FIG. 1), and a condenser cooling system (such as 200 in FIG. 2). In an example embodiment, the controller may be utilized to receive temperature measurement data from the condenser cooling system (such as 200 in FIG. 2) and provide independent control for each condenser cell fan.

FIG. 4 depicts an end view example of a single condenser cell associated with a cooling system 400 for condensing steam 402. The steam may be supplied from a turbine supply header, for example. In an example embodiment, the steam 402 may be directed through condenser tubes 404 for heat exchange with ambient air, forced air, and/or cooling water fogging. According to example embodiments, the condenser tubes may include chilling fins for increased surface area and increased efficiency of the heat exchange. After the steam is cooled, it may condense and may return in the form of liquid to a hot well via well collection headers 406. According to an example embodiment, the cooling air 408 may be drawn towards the cooling cell via a fan. The fan may include a fan motor 410 and one or more blades 412. In an example embodiment, the fan may blow the cooling air 408 past and around the condenser tubes 404 to exchange heat from the steam within the condenser tubes 404. In an example embodiment, the exchanged heat may be carried away from the condenser cell via discharge air 416.

FIGS. 4-6 depict example embodiments of cooling systems 400, 500, 600 that each represent different embodiments for placement of respective cooling water fogging headers 414, 504, 602. According to an example embodiment, approximate fogging coolant paths 414 may be controlled, at least in part, by the placement of the fogging headers 414. In example embodiments, the fogging header spray nozzle orientation may further allow control of the fogging coolant paths 114. For example, FIG. 4 depicts an example cooling system 400 where the fogging headers 414 are placed approximately parallel with the condenser tubes 404. Certain advantages, for example, cooling efficiencies, fogging water conservation, ease of assembly, ease of repair etc., may be realized by the particular configuration and placement of the fogging headers 414, and the direction of the fogging spray.

FIG. 5 depicts another example embodiment where the fogging headers 502 are placed approximately parallel with the plane of the fan blades. In this example embodiment, the length of the approximate cooling fog path 504 may be longer for fog traveling towards the higher temperature portion of the condenser pipes and fins, and may provide additional cooling of the air prior to the heat exchange process.

FIG. 6 depicts another example embodiment where the fogging headers 602 may be placed in an arrangement that may facilitate one, two, or more interaction regions 608 between the fogging paths 604 and the condenser tubes and chilling fins 610. In an example embodiment, cooling may be enhanced by selectively directing the coolant towards the condenser tubes and chilling fins 610 of one or more cells, and in an opposing direction of the forced air such that at least a portion of the coolant removes heat from the one or more cells. In an example embodiment, the fogging headers 602 may be placed on the outside of the condenser tube structures with the fogging nozzles directing fog towards the condenser tubes and chilling fins 610. In an example embodiment, the fog paths 604 may first encounter the condenser tubes and chilling fins 610 in an interaction region 608, and then by the airflow 606 produced by the fan, may again encounter the condenser tubes and chilling fins 610 in another interaction region 608. Similar example embodiments may be utilized to increase the efficiency of the heat exchange process. Other example configurations may be utilized without departing from the scope of the claimed inventions.

An example method 700 for controlling steam turbine output will now be described with reference to the flowchart of FIG. 7. According to an example embodiment, the method 700 starts in block 702 and includes measuring one or more temperatures or back pressures associated with one or more cells associated with a turbine cooling condenser. In block 704, and according to an example embodiment, the method 700 includes controlling temperature distribution of the one or more cells in response, at least in part, to the measured one or more temperatures or back pressures. The method 700 ends after block 704.

Accordingly, example embodiments of the invention can provide the technical effects of providing enhanced control and cooling of condenser cells. Example embodiments of the invention can provide the further technical effects of selectively cooling certain condenser cells based on temperature measurements of the cells.

In example embodiments of the invention, the turbine and cooling system 100, the cooling control system 300, and the cooling systems 400-600 may include any number of hardware and/or software applications that are executed to facilitate any of the operations.

In example embodiments, one or more I/O interfaces may facilitate communication between the turbine and cooling system 100, the cooling control system 300, and the cooling systems 400-600 and one or more input/output devices. For example, a universal serial bus port, a serial port, a disk drive, a CD-ROM drive, and/or one or more user interface devices, such as a display, keyboard, keypad, mouse, control panel, touch screen display, microphone, etc., may facilitate user interaction with the turbine and cooling system 100, the cooling control system 300, and/or the cooling systems 400-600. The one or more I/O interfaces may be utilized to receive or collect data and/or user instructions from a wide variety of input devices. Received data may be processed by one or more computer processors as desired in various embodiments of the invention and/or stored in one or more memory devices.

One or more network interfaces may facilitate connection of the turbine and cooling system 100, the cooling control system 300, and the cooling systems 400-600 inputs and outputs to one or more suitable networks and/or connections. For example, the connections may facilitate communication with any number of sensors associated with the system. The one or more network interfaces may further facilitate connection to one or more suitable networks; for example, a local area network, a wide area network, the Internet, a cellular network, a radio frequency network, a Bluetooth™ (owned by Telefonaktiebolaget LM Ericsson) enabled network, a Wi-Fi™ (owned by Wi-Fi Alliance) enabled network, a satellite-based network any wired network, any wireless network, etc., for communication with external devices and/or systems.

As desired, embodiments of the invention may include the turbine and cooling system 100, the cooling control system 300, and the cooling systems 400-600 with more or less of the components illustrated in FIGS. 1, 3, 4, 5, and 6.

The invention is described above with reference to block and flow diagrams of systems, methods, apparatuses, and/or computer program products according to example embodiments of the invention. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, respectively, can be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some embodiments of the invention.

These computer-executable program instructions may be loaded onto a general-purpose computer, a special-purpose computer, a processor, or other programmable data processing apparatus to produce a particular machine, such that the instructions that execute on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in the flow diagram block or blocks. These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks. As an example, embodiments of the invention may provide for a computer program product, comprising a computer-usable medium having a computer-readable program code or program instructions embodied therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks.

Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, can be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.

While the invention has been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.