Patent Description:
<CIT> discloses a refrigeration system comprising a compressor, a condenser, an evaporator, an inner control loop for optimizing refrigerant supply to the evaporator, and an outer control loop for optimizing refrigerant levels in the evaporator. The outer control loop defines a supply rate for the inner control loop based on an optimization including measurement of evaporator performance. The inner control loop optimizes liquid refrigerant supply based on said defined supply rate.

<CIT> discloses a hybrid heat exchanger apparatus and method of operation involving a direct heat exchanger device and an indirect heat exchanger device. A hot fluid to be cooled from a hot fluid source is conveyed through the indirect heat exchanger device to a cooling fluid distribution system, and is then distributed from the cooling fluid distribution system onto the direct heat exchanger device. In a hybrid wet/dry mode, ambient air flows across both the indirect heat exchanger device and the direct heat exchanger device to generate hot humid air from the ambient air flowing across the direct heat exchanger device and hot dry air from the ambient air flowing across the indirect heat exchanger device.

<CIT> discloses a cooling system including a cooling tower, a refrigeration device, a cooling fan provided in the cooling tower, a cooling water pump circulating cooling water between the cooling tower and the refrigeration device, a temperature sensor which detects the cooling water temperature at an inlet or outlet of the cooling tower, and an inverter apparatus which variably controls the speed of the cooling tower. The output frequency of the inverter apparatus is gradually reduced after the output frequency reaches an upper limit frequency, a condition at which a temperature detection value of the cooling water does not rise despite the reduction in the output frequency is stored, and the inverter apparatus is operated thereafter on the basis of the stored condition.

<CIT> discloses a combination wet-dry cooling system for an axial flow steam turbine having a portion of the exhaust steam from the turbine condensed by cooling water circulating through a condenser and through a wet cooling tower, and having another portion of the exhaust steam condensed by liquid coolant circulated in a finned tube heat exchanger. The heat from the liquid coolant is transferred to the air, and the liquid coolant is passed through the tubes extending through the condenser, or the liquid coolant is sprayed directly into the condenser to provide mixing condensing, thus providing a cooling system, which eliminates the objectionable plume associated with wet cooling towers and which is smaller than dry cooling towers.

<CIT> discloses methods and systems for pre-cooling. A cooling system includes a condenser having a condenser inlet and a condenser outlet. The system also includes a cooling tower including a cooling tower inlet and a cooling tower outlet. The system further includes a heat exchanger including a first heat exchanger inlet and a first heat exchanger outlet. The first heat exchanger inlet is fluidically coupled to the cooling tower outlet, and the first heat exchanger outlet is fluidically coupled to the condenser inlet.

<CIT> discloses a dry and wet separation multi-air-inlet composite closed cooling tower and an operation adjusting method thereof. A tower body is divided into a left chamber and a right chamber by a partition plate disposed within a tower body cavity, the left chamber is provided with an air valve and a finned tube heat exchanger from top to bottom, the right chamber is provided with a water absorbing device, a spraying and discharging pipe, a light pipe heat exchanger, a filler and a water collecting tank from top to bottom, a first fan and a second fan are arranged at the top of the left chamber and the top of the right chamber respectively, and a first air inlet, a second air inlet and a third air inlet are arranged on the left side wall surface of the left chamber, the bottom of the left chamber and the right side wall surface of the right chamber. According to the tower, dry air cooling and evaporative cooling are separated, flexible switching and combination of dry air cooling and evaporative cooling under various air inlet working conditions can be achieved by controlling opening states of the different air inlets and the different fans according to changes of an outdoor environment temperature and a cooling heat dissipation load so as to achieve the maximum energy-saving and water-saving effect.

A first aspect of the disclosure provides an integrated circulating water cooling system that comprises at least one load; an air cooling sub-system; a wet surface cooling sub-system; at least one temperature sensor; a control; and a coolant circulation sub-system for fluidly circulating coolant from the at least one load to the air cooling sub-system to the wet surface cooling sub-system and back to the at least one load. The control selectively operates the wet surface cooling sub-system and the air cooling sub-system based on at least one of: temperature sensed in the water circulation sub-system; or sensed ambient temperature. The air cooling sub-system includes a fan operable to draw air into and through the air cooling sub-system, and includes a fan operable to force air into and through the air cooling sub-system, the fans being selectively operable based on a sensed temperature.

The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed.

These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which:
<FIG> illustrates schematic wet dry integrated circulation cooling system, according to embodiments of the disclosure.

It is noted that the drawings of the disclosure are not to scale.

As an initial matter, in order to clearly describe the current technology it will become necessary to select certain terminology when referring to and describing relevant components within cooling systems, including turbomachine cooling systems. To the extent possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. Unless otherwise stated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different or overlapping terms. What may be described herein as being a single part may include and be referenced in another context as consisting of multiple components. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part.

In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the onset of this section. These terms and their definitions, unless stated otherwise, are as follows. As used herein, "downstream" and "upstream" are terms that indicate a direction relative to the flow of a fluid, such as the working fluid through the turbine engine or, for example, the flow of air through the combustor or coolant through one of the turbine's component systems. The term "downstream" corresponds to the direction of flow of the fluid, and the term "upstream" refers to the direction opposite to the flow.

It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Where an element or layer is referred to as being "on," "engaged to," <NUM> "connected to" or "coupled to" another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to" or "directly coupled to" another element or layer, there may be no intervening elements or layers present.

Turbomachinery systems, their components, and sub-systems often benefit from cooling for enhanced, efficient and prolonged life of the overall system and its individual components and sub-systems. Maintaining cooling of components and sub-systems may enable higher operating temperatures which in turn may augment higher thermal efficiency, may extend component life, and can increase turbomachinery output. Therefore, as discussed herein, controlled operation of an air cooling sub-system and wet surface cooling sub-system with a turbomachine system is useful in providing efficient turbomachine operation, control coolant reserves, and operation flexibility.

Referring now to the drawing in detail, <FIG> illustrates a schematic diagram of a wet-dry integrated circulation cooling system <NUM> in accordance with embodiments of the disclosure. Wet dry integrated circulation cooling system <NUM> includes a load <NUM>, an (or dry) air cooling sub-system <NUM>, a wet surface cooling sub-system <NUM> (air cooling sub-system <NUM> and wet surface cooling sub-system <NUM> define heat exchangers in wet dry integrated circulation cooling system <NUM>), a control <NUM>, a coolant circulation sub-system <NUM> where the coolant includes but in no way is intended to be limited to water, and sensors <NUM>, <NUM>, <NUM>. As indicated in <FIG>, air cooling sub-system <NUM> and wet surface cooling sub-system <NUM> are in series.

Coolant fluid, for example water (hereinafter referred to as "water" for ease of description), flows in a circuit through conduits <NUM> of water circulation sub-system <NUM>. As illustrated, the circuit extends through load <NUM> to air cooling sub-system <NUM> and then to wet surface cooling sub-system <NUM>, and then back to load <NUM>. In other words, water circulation sub-system <NUM> fluidically connects load <NUM>, air cooling sub-system <NUM>, and wet surface cooling sub-system <NUM> and their components as discussed herein. Flow of water to wet surface cooling sub-system <NUM> can be controlled by opening and closing valves <NUM>, <NUM>, <NUM> in water circulation sub-system <NUM>, wherein water circulation sub-system <NUM> and its components (described hereinafter) are controlled by control <NUM>. Water circulation sub-system <NUM> includes at least one pump <NUM> shown in phantom at various possible locations in water circulation sub-system <NUM> for circulating water therethrough. The at least one pump <NUM> of water circulation sub-system <NUM> can be located at any point along conduit <NUM>, for example before or after load <NUM>, before or after air cooling sub-system <NUM>, before or after wet surface cooling sub-system <NUM>, and/or before or after any of valves <NUM>, <NUM>, <NUM> and/or temperature sensors <NUM>, <NUM>, <NUM>. Further, in accordance with aspects of the disclosure more than one pump <NUM> for water circulation sub-system <NUM> can be provided.

Load <NUM> includes a load that may need cooling for its operation. In particular, as embodied by the disclosure, load <NUM> can include turbomachinery and/or power plant components. For example, and not intended to limit the disclosure in any manner, load <NUM> can include at least one of a generator <NUM> and a turbine <NUM>. Turbine <NUM> can be a gas turbine, steam turbine or any other device that can generate motive forces, now known or hereinafter developed. Moreover, load <NUM> can also include heat recovery steam generators, gas driers, compressors, heat exchangers, and other load devices, now known or hereinafter developed that may need cooling.

Air cooling sub-system <NUM> is a dry cooling sub-system that includes a fin cooler, such as but not limited to, a finned-tube bundle with multiple parallel rows of finned tubes <NUM> in a series. Water from water circulation sub-system <NUM> flows to air cooling sub-system <NUM>. Water is divided at manifold <NUM> of water circulation sub-system <NUM> to finned tubes <NUM>. Air cooling sub-system <NUM> includes a housing <NUM> supporting finned tubes <NUM> in spaced relationship, such as but not limited to, parallel rows. Housing <NUM> is open to atmosphere and permits air flow in and out (see arrows X) of housing <NUM> and across finned tubes <NUM>.

Air cooling sub-system <NUM> includes an active cooling mode, where one or more fans <NUM>, <NUM> move air across finned tubes <NUM>. If fan <NUM> blows air upwards (in the plane of <FIG>), air cooling sub-system <NUM> is a forced air cooling sub-system <NUM>. If fan <NUM> is employed to pull air up through housing <NUM>, the sub-system is referred to as an induced air cooling sub-system system <NUM>. Fan(s) <NUM>, <NUM> are used to move ambient air over finned tubes <NUM> to cool water being circulated through tubes <NUM> transferring heat to the ambient air. Thus, the temperature of water in water circulation sub-system <NUM> as water passes through air cooling sub-system <NUM> can be lowered. Water exits air cooling sub-system <NUM> and is rejoined into water circulation sub-system <NUM> at manifold <NUM>. If fan(s) <NUM>, <NUM> are directed by control <NUM> not to operate, in other words be in an "off" condition, no active cooling will be completed at air cooling sub-system <NUM>. However, in the "off" condition, heat may dissipate via normal thermodynamic principles out of fins of finned tubes <NUM>, albeit to a lesser extent than provided by active cooling with fan(s) <NUM>, <NUM> operating.

From manifold <NUM>, water flows in conduit <NUM> of water circulation sub-system <NUM> towards wet surface cooling sub-system <NUM>. Before reaching wet surface cooling sub-system <NUM>, the flow of water can be controlled by opening and/or closing values <NUM>. The operation of valves <NUM>, <NUM>, <NUM> is controlled by control <NUM>, as described hereinafter. If valves <NUM>, <NUM> are open and valve <NUM> is closed, flow is directed into wet surface cooling sub-system <NUM>. Alternatively, manual isolation valves can also be used in place of controls operated valves.

Wet surface cooling sub-system <NUM> includes two separate heat exchange portions <NUM> and <NUM> and <NUM>. Each heat exchange portion will effectively extract heat of coolant water. Heat exchange portion <NUM> of wet surface cooling sub-system <NUM> includes housing <NUM> with a plurality of serpentine tubes <NUM> extending therethrough. The tubes <NUM> are so arranged with respect to water circulation sub-system <NUM> so liquid coolant, generally water, flows through serpentine tubes <NUM> from conduit <NUM>, after passing through valve <NUM>, if the control <NUM> has opened valves <NUM>, <NUM> and closed valve <NUM>, as described herein.

Heat exchange portion <NUM> of wet surface cooling sub-system <NUM> includes a spray distributor <NUM>, which atomizes liquid, in this case liquid condensate <NUM>. Liquid condensate <NUM> is liquid that spray distributor <NUM> distributes over plurality of serpentine tubes <NUM> to dissipate heat from water in serpentine tubes <NUM>. After passing on, around, and through serpentine tubes <NUM>, sprayed liquid settles in housing <NUM> in a reservoir <NUM>' as liquid condensate <NUM>. Serpentine tubes <NUM> provide a large surface area so that when liquid condensate <NUM> from spray distributor <NUM> comes in contact with serpentine tubes <NUM>, it absorbs heat therefrom.

A portion of liquid condensate <NUM> is circulated by pumps <NUM> through wet surface cooling sub-system piping <NUM> to direct condensate liquid <NUM> to spray distributor <NUM>. The spray from spray distributor <NUM> contacts serpentine tubes <NUM> to promote cooling, as noted herein.

<FIG> illustrates two pumps <NUM>, however only one pump <NUM>, or more than two pumps, may be provided and/or operated with wet surface cooling sub-system piping <NUM>, in accordance with aspects of the disclosure. Wet surface cooling sub-system piping <NUM> is connected to pump(s) <NUM> that pulls liquid condensate <NUM> from housing reservoir <NUM>'. From pump(s) <NUM> wet surface cooling sub-system piping <NUM> delivers liquid condensate <NUM> to manifold <NUM> and then to spray heads <NUM>. Provision of two pumps <NUM>, or more than two pumps, enables faster movement of liquid condensate <NUM> and control the flow requirement based on temperature sensed in the system by control <NUM>.

Spray distributor <NUM> includes at least one and preferably a plurality of spray heads <NUM> that are fed from a manifold <NUM> of wet surface cooling sub-system piping <NUM> and pump(s) <NUM>. <FIG> shows one manifold <NUM> with five (<NUM>) spray heads <NUM>; however, this configuration is merely illustrative of aspects of the disclosure. Moreover, noting the restrictions of two-dimensional figures, aspects of the embodiment include, but are not limited to one, two, or more manifolds <NUM>. Further, another aspect of the disclosure includes a single spray head <NUM> per manifold <NUM>, or two spray heads <NUM> per manifold <NUM>, or more than two spray heads per manifold <NUM>. Additionally, the number of spray heads <NUM> per manifold <NUM> need not be equal per manifold <NUM>. For example, and in no way intended to limit the embodiments in any manner, one manifold may have five (<NUM>) spray heads <NUM> (as illustrated) and subsequent manifolds <NUM> may have the same or different numbers of spray heads <NUM> thereon.

Wet surface cooling sub-system <NUM> includes at least one fan <NUM> for drawing air (and possibly steam) that has had heat extracted therefrom from water circulation sub-system <NUM>. Housing <NUM> includes openings <NUM> proximate fan <NUM>, so air being moved by fan <NUM> can escape housing and wet surface cooling sub-system <NUM>.

Wet surface cooling sub-system <NUM> also includes a reserve water supply <NUM>, which provides water for wet surface cooling sub-system <NUM> if evaporation of condensate liquid <NUM> in reservoir <NUM>' occurs to a degree where considerate liquid <NUM> is in need of replenishment. A level control valve <NUM> is disposed on wet surface cooling sub-system piping <NUM> in housing <NUM>, so if condensate liquid <NUM> in housing reservoir <NUM>' falls below a predetermined level, a signal from level control valve <NUM> signals control <NUM> to operate pump(s) <NUM> to transfer water from makeup water supply <NUM> into housing <NUM>, for example through an opening <NUM> into housing reservoir <NUM>' through wet surface cooling sub-system piping <NUM>. Alternatively, level control valve <NUM> signals control <NUM> to operate pump(s) <NUM> to transfer water from makeup water supply <NUM> into housing <NUM>, for example through wet surface cooling sub-system piping <NUM> to manifold <NUM> and spray heads <NUM>.

Air cooling sub-system <NUM> is disposed upstream of wet surface cooling sub-system <NUM> so that wet surface cooling sub-system <NUM> has a portion of water circulation sub-system <NUM> which may have had its liquid cooled to a certain degree by air cooling sub-system <NUM>. Therefore, wet surface cooling sub-system <NUM> is able to further extract heat from water in water circulation sub-system <NUM>. Operation of pump(s) in water circulation sub-system <NUM> can be controlled (as described herein) to efficiently, and only as needed, provide liquid condensate <NUM> to wet surface cooling sub-system <NUM>.

Control <NUM> is connected to elements of the water circulation sub-system <NUM>. Control <NUM> is connected to temperature sensors <NUM>, <NUM>, <NUM> of water circulation sub-system <NUM>. Control <NUM> is connected to pump(s) <NUM> to move coolant in water circulation sub-system <NUM>. Moreover, control <NUM> is connected to valves <NUM>, <NUM>, <NUM> of water circulation sub-system <NUM> for permitting or stopping flow of water through those portions of water circulation sub-system <NUM>, as described herein. Further, control <NUM> is connected to pump(s) <NUM> to control water flow and liquid condensate <NUM> levels in wet surface cooling sub-system <NUM>. Additionally, control <NUM> is connected to pump(s) <NUM> and float valve <NUM> to add makeup water from reserve water supply <NUM>, if a level of liquid condensate <NUM> in housing reservoir <NUM>' falls below a predetermined level.

Temperature sensors <NUM> and <NUM> are disposed before and after air cooling sub-system <NUM> and provide data on temperatures of water in water circulation sub-system <NUM> before and after air cooling sub-system <NUM>. Control <NUM> is also connected to fan(s) <NUM>, <NUM> of air cooling sub-system <NUM> to control speeds of fan(s) <NUM>, <NUM> and their operation. Accordingly, as desired and necessitated by temperatures that are sensed by sensors <NUM> and <NUM>, control <NUM> can operate bottom fan <NUM> to force air upwardly so air cooling sub-system <NUM> is a forced air cooling sub-system air cooling sub-system <NUM>, or operate fan <NUM> to pull air up through housing <NUM>, so air cooling sub-system <NUM> is an induced air cooling sub-system <NUM>. If desired, control <NUM> can operate both fans <NUM>, <NUM> for enhanced cooling by air cooling sub-system <NUM>.

Temperature sensors <NUM>, <NUM> respectively are positioned before and after wet surface cooling sub-system wet surface cooling sub-system <NUM>. Temperature sensors <NUM>, <NUM> provide data to control <NUM> indicating if wet surface cooling sub-system <NUM> is effectively working to cool water in water circulation sub-system <NUM>. As noted above, two pumps <NUM> may be provided in wet surface cooling sub-system <NUM> with wet surface cooling sub-system piping <NUM>. By providing data from sensors <NUM>, <NUM>, control <NUM> can operate one, two, or more (if provided) pumps <NUM> for wet surface cooling sub-system <NUM>. This configuration permits one or more pump(s) <NUM> for spray distributor <NUM>. Accordingly, based on data from temperature sensor <NUM> before wet surface cooling sub-system <NUM>, control <NUM> can run necessary pumps <NUM> and limit makeup water requirements.

Control <NUM> is also connected to a temperature sensor <NUM> that senses ambient temperature. In low ambient temperature periods when cooling water inlet temperature to wet surface cooling sub-system <NUM> is lower than needed or required cooling water temperature for load <NUM>, control <NUM> operates to cease operation of wet surface cooling sub-system sub-system <NUM> for cooling water in water circulation sub-system <NUM>. Thus, control <NUM> instructs valves <NUM>, <NUM> to close and valve <NUM> to open. Accordingly, water in water circulation sub-system <NUM> is directed to by-pass conduit <NUM>, not passing through wet surface cooling sub-system sub-system <NUM>, and is returned via water circulation sub-system <NUM> to load <NUM>. Thus, one or more pump(s) <NUM> and spray distributor <NUM>, as well as fan <NUM> in wet surface cooling sub-system <NUM> may be in an off, stand-by, and inoperative mode. These elements will remain in that mode until control <NUM> senses an ambient temperature at sensor <NUM> and a water temperature at sensors <NUM>, <NUM> before and after wet surface cooling sub-system <NUM> that indicates load <NUM> needs cooler coolant in water circulation sub-system <NUM>.

Once that need for cooler water for load <NUM> is determined by control <NUM>, control <NUM> will reinitiate operation of wet surface cooling sub-system <NUM> and open valves <NUM>, <NUM>, closing valve <NUM>. Thus, a series cooling flow from load <NUM> to air cooling sub-system <NUM> to wet surface cooling sub-system <NUM> and back to heat load <NUM> is initiated.

A further aspect of the disclosure, enables control <NUM> to halt operation of fan(s) <NUM>, <NUM> of air cooling sub-system <NUM> so water in water circulation sub-system <NUM> merely passes through air cooling sub-system <NUM> in housing <NUM>. Here, no active cooling is done by air cooling sub-system air cooling sub-system <NUM>. Wet surface cooling sub-system <NUM> alone performs the active cooling of water in water circulation sub-system <NUM>. Of course, control <NUM> can initiate operation of fan(s) <NUM>, <NUM> of air cooling sub-system <NUM> as needed depending on cooling needed by load <NUM> and/or high ambient temperature periods sensed by sensor <NUM>.

An aspect of the disclosure provides control <NUM> as a stand-alone system. Alternatively, control <NUM> may be integrated as a module, or the like, within a broader system, such as a turbine control or a plant control system. For example, but not limiting of, control <NUM> may be integrated with a control system operating the overall power plant in which the wet dry integrated cooling system is installed.

Control <NUM>, as embodied by the disclosure, can also be provided as any combination of one or more computer usable or computer readable medium(s). More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a transmission media such as those supporting the Internet or an intranet, or a magnetic storage device. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable medium may include a propagated data signal with the computer-usable program code embodied therewith, either in baseband or as part of a carrier wave. The computer usable program code may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc..

Accordingly, a value modified by a term or terms, such as "about," "approximately" and "substantially," are not to be limited to the precise value specified. Here and throughout the specification and claims, range limitations may be combined and/or interchanged; such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. "Approximately" as applied to a particular value of a range applies to both end values, and unless otherwise dependent on the precision of the instrument measuring the value, may indicate +/- <NUM>% of the stated value(s).

Claim 1:
An integrated circulating water cooling system for at least one load (<NUM>), the system comprising:
an air cooling sub-system (<NUM>);
a wet surface cooling sub-system (<NUM>);
a control (<NUM>); and
a coolant circulation sub-system for fluidly circulating coolant from the at least one load (<NUM>) to the air cooling sub-system (<NUM>) to the wet surface cooling sub-system (<NUM>) and back to the at least one load (<NUM>); characterised in that
at least one temperature sensor (<NUM>) is provided, in that the control (<NUM>) selectively operates at least one of the wet surface cooling sub-system (<NUM>) and the air cooling sub-system (<NUM>) based on at least one of:
temperature sensed in the coolant circulation sub-system; and
sensed ambient temperature;
and in that the air cooling sub-system (<NUM>) includes a first fan (<NUM>) operable to draw air into and through the air cooling sub-system (<NUM>), and includes a second fan (<NUM>) operable to force air into and through the air cooling sub-system (<NUM>), the first fan (<NUM>) and the second fan (<NUM>) being selectively operable based on a sensed temperature.