Description: FIELD OF THE INVENTION:
[001] The present invention relates to a tube nest layout of axial circular two-pass steam condenser for power plant or chemical plant application. More particularly, the invention relates to an optimized tube nest layout for a two-pass circular condenser with improved tube nest layout arrangement and pressure drop equalized across different tube bundles from all directions.

BACKGROUND/PRIOR ART OF THE INVENTION:
[002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] The main purpose of a steam condenser is to condense steam from the exhaust of a low-pressure steam turbine. It consists of a number of cooling tubes as high as 30,000 in a large power plant steam condenser. The performance of the condenser is mainly dependent on the arrangement of tubes which gives 1) equalized steam distribution to all the tube bundles 2) well-connected air extraction lanes 3) deaeration of condensate and 4) minimum pressure loss across the tube nest. Condensers can be of a single pass or two pass type depending on the availability of height for the location of the equipment below the turbine.
[004] Various innovations and patents cover the different sealing techniques and technologies developed for optical fiber hermetical sealing.
[005] In prior art, US5649590A, titled “Bundle of tubes for a steam condenser” a tube layout in the form of radiating spikes is disclosed. Some of the spikes spilt at least once into branches and wherein said spikes radiate from a tube containing area that forms a circular ring. This type of layout makes it possible to arrange larger number of tubes in a given area of the tube plate.
[006] Another prior art, US5960867A, titled “Condenser and power plant” describes another version of tube nest layout. The tube nest is spaced from bottom surface and side walls of the condenser so that steam is able to flow from all directions in to the tube nest with reduced velocity. The extracting opening is disposed below the center of gravity of the outer circumference and the width of each of the flow passages increases towards open outer and. The area ratio and length of the flow passage increase towards the central axis of tube nest. The advantage claimed are reduced pressure loss and improved non condensable evacuation.
[007] Another prior art, US6269867B1, titled “Condenser and power plant” describes a tube nest which has amassed region of cooling tubes and plurality of tube bundles with flow passages. A non-condensable gas extracting tube is arranged among the cooling tubes in the massed region. A cooling unit or a steam condensing chamber for condensing steam contained in non-condensable gases which are extracted from the non-condensable gas extracting tube is arranged in the massed region. A discharge flow passage is formed at least partially in the tube next so as to enable the non-condensable gases from the cooling unit or the steam condensing chamber to be discharged outside of the condenser, whereby condensing efficiency of the steam contained in the non-condensable gases which flow into the cooling unit or the steam condensing chamber is improved.
[008] Another prior art, US7481264B2, titled “Steam condenser” describes about a steam condenser having heat transfer tubes arranged in two upper groups and at least two lower groups with gap between each other. A baffle plate is placed at lower part between two lower groups obstructing flow of steam extends horizontally. Between upper and lower heat transfer groups, inter tube group inundation prevention plates extend horizontally. In each heat transfer group an enclosure part extends to guide gas from enclosure part to outside of the container through a gas extraction duct.
[009] Another prior art, US20010025703A1, titled “Condenser” describes inventions relating to a condenser on the church window principle. The condenser comprises at least one bundle with a multiplicity of tubes arranged parallel to one another, the bundle being subdivided into an upper sector and a lower sector. The tubes have a first fluid flowing through them and the vaporous fluid flowing around them. A condensate discharge element is arranged in the bundle between the upper sector and the lower sector preventing the extent blockage of steam paths.
[0010] Another prior art, JP3858725B2, titled “Condenser” describes a tube nest which has amassed region of cooling tubes and plurality of tube bundles with flow passages. A non-condensable gas extracting tube is arranged among the cooling tubes in the massed region. A cooling unit or a steam condensing chamber for condensing steam contained in non-condensable gases which are extracted from the non-condensable gas extracting tube is arranged in the massed region.
[0011] Another prior art, JP2015068613A, titled “Condenser” describes a tube nest that has amassed region of cooling tubes and plurality of tube bundles with flow passages. A non-condensable gas extracting tube is arranged among the cooling tubes in the massed region with gas extracting tube from the sides of the condenser. The tube arrangement is isolated bundles with no interconnection. Entry of steam is from top and removal of condensate is from bottom of the condenser.
[0012] To protect moisture ingress inside the insulator a novel sealing design was incorporated. Therefore, there is a need of ease of fiber handling during assembly and maintenance.
[0013] In view of the above, there is requirement to devise an apparatus/fixture which can address the aforesaid shortcoming(s)/fulfill the requirements. Hence, the present invention has been introduced to serve the purpose efficiently.
[0014] The information disclosed in this background of the disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

OBJECTS OF THE INVENTION:
[0015] It is therefore the object of the present subject matter to provide a tube nest arrangement which overcomes the aforementioned and other drawbacks in prior method/product/apparatus.
[0016] The present invention is based on the object of providing a tube nest arrangement for a two-pass, circular condenser catering axial entry of steam in to condenser having improved bundle design.
[0017] Another object of the present invention is to provide a tube nest arrangement for a two-pass, circular condenser catering axial entry of steam in to condenser having well connected gas extraction vent lanes for improved gas evacuation.
[0018] Another object of the present invention is to provide well-spaced converging steam lanes.
[0019] Another object of the present invention is to provide equalised steam distribution.
[0020] Another object of the present invention is to provide prevention of air pocket formation.
[0021] Another object of the present invention is to provide optimum pressure drop across bundle of different sections.
[0022] Further, another object of the present invention is to provide better utilisation of tube sheet area.
[0023] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION:
[0024] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.
[0025] The present invention relates to a tube nest layout of axial circular two-pass steam condenser for power plant or chemical plant application.
[0026] The present invention provides a two pass circular condenser tube nest layout comprising a steam inlet through which steam is received, a plurality of cooling tubes for condensing steam received through the steam inlet, a condensate out let through which condensate produced by the cooling tubes is discharged and at least one extracting means through which non-condensable gases are extracted.
[0027] According to the present invention, there is disclosed an axial circular two-pass steam condenser having tube nest layout, for power plant or chemical plant application, the condenser comprising:
a steam inlet, to receive steam in the condenser;
a plurality of cooling tubes, arranged on a tube plate, for condensing steam received through the steam inlet;
a plurality of vent lanes, to guide the steam with high concentration of non-condensable gases towards an air cooling zone;
a plurality of baffle plates, to guide the steam with high gas concentration towards a gas evacuation pipe located in a gas evacuation passage for gas evacuation by an evacuation device;
a plurality of bundles, arranged in array before the gas evacuation passage in a horizontal fashion; and
a condensate outlet hot well, to discharge condensate condensed in the plurality of cooling tubes;
wherein the said tube nest layout provides uniform and even steam distribution to all the sections of the bundles and approximately 5-7% steam to air cooling zone.
[0028] In an aspect of the present invention, a vessel surrounds the tube nest of the plurality of cooling tubes having the steam inlet at the entry and condensate outlet hot well at the exit.
[0029] In another aspect of the present invention, the steam lanes are formed in such a way that the steam quantity drawn is in proportion to the total number of cooling tubes in the respective bundles located at different sections.
[0030] In another aspect of the present invention, the shape of the steam lane is converging in nature to maintain the required steam velocity through the steam lanes.
[0031] In another aspect of the present invention, the tube bundles are designed and arranged as a mirror image of horizontal sections A-A through the centerline of the gas evacuation pipe.
[0032] In another aspect of the present invention, the shape of tube bundles is converging in nature.
[0033] In another aspect of the present invention, one tube nest is used in a single section condenser, or two such tube nests as a mirror image to each other are used in a double section condenser.
[0034] The present invention is achieved by the features of the principal claims and subsequent claims.
[0035] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0036] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0037] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0038] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods or structure in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:

[0039] Figure 1 illustrates a cross sectional view of configuration of cooling tubes on tube plate, in accordance with an embodiment of the present invention;
[0040] Figure 2 illustrates a cross sectional view of the steam flow path, in accordance with an embodiment of the present invention;
[0041] Figure 3 illustrates a cross sectional view of flow of air and gas evacuation lanes in condenser layout, in accordance with an embodiment of the present invention;
[0042] Figure 4 illustrates a cross sectional view of the tube bundles and shell with horizontal with flow entry and exit flow passages configuration, in accordance with an embodiment of the present invention;
[0043] Figure 5 illustrates a cross sectional view of overall layout of condenser with tube nest and internals., in accordance with an embodiment of the present invention;

[0044] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) OF THE PRESENT INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS:

[0045] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
[0046] The present invention relates to a tube nest layout of axial circular two-pass steam condenser for power plant or chemical plant application.
[0047] In the present invention, the design for air assisted electrostatic nozzle system has been optimized to provide for efficient mass transfer,
[0048] Now, reference may be made to the accompanying figures.
[0049] Referring to Figure 1, illustrating a schematic view of configuration of cooling tubes (1) on a tube plate (2). A plurality of cooling tubes (1) is arranged on tube plate (2). A plurality of bundles (12) are arranged in array before the gas evacuation passage (11) in a horizontal fashion. At least two conical steam bundles facing the steam entry in both the passes are formed by providing the plurality of cooling tubes (1) in an air cooling zone (7) to facilitate stream lined steam entry to the plurality of horizontal bundles (12). A plurality of steam lanes (3) are formed as shown in fig – 1 for better steam distribution to tube bundles (12) and vent lanes (4) for effective removal of liberated non condensable gases along with steam towards air cooling zone (7) for further condensation of steam and removal of non-condensable along with steam as per HEI standard”. The shape of each of the plurality of the steam lanes (3) is such that uniform steam velocity is maintained. The width of each of the plurality of the steam lanes (3) is selected based on the steam quantity to be received into the plurality of bundles (12) to maintain comparable velocities in the each of the plurality of the steam lanes (3). The bundle width and shape are worked out based on the equalisation of pressure drop in an optimum manner.
[0050] Steam also passes through a central lane (5) and a top gap (13) for supply of steam to last most cooling tube (1) of the horizontal bundle (12). A plurality of vent lanes (4) is provided to guide the steam with high concentration of non-condensable gases towards the air cooling zone (7). A plurality of baffle plates (6, 6a) are provided to prevent direct bye-passing of steam into the air cooling zone (7) and guide the steam with high gas concentration towards the gas evacuation pipe located in a passage (11) for gas evacuation by the evacuation device not shown in the figure. A vessel (10) surrounds the tube nest which has steam inlet at the entry and condensate outlet hot well (8) at the exit and then to the condensate evacuation pump not shown in figure.

[0051] Referring to Figure 2, illustrating a cross sectional view of the steam flow path showing steam entry and stem exit flow passages. The tube nest design provides uniform and even steam distribution to all the sections of the bundles (12) and approximately 5-7% steam to the air cooling zone (7). The number of cooling tubes (1) crossed is decided based on the steam to be condensed in that section satisfying the pressure loss balance among the other sections of the bundles (12) in optimum manner. The shape of cooling tube nest is as shown in Fig-1. Steam lanes (3) are formed in such a way that the steam quantity drawn is in proportion to the total number of cooling tubes (1) in the respective bundles (12) located at different sections. The shape of steam lane (3) is converging in nature to maintain the required steam velocity through the steam lane (3). Tube bundles (12) are designed and arranged as mirror image of horizontal section A-A through the center line of the gas evacuation pipe as shown in fig-1. Cooling tube bundle (12) is provided before the gas evacuation passage (11) for residual condensation and minimum steam venting through gas evacuation device.
[0052] Referring to Figure 3, illustrating a cross sectional view of flow of air and gas evacuation lanes in condenser layout. All the air and gas evacuation lanes are constructed in such a way that they are expanding in nature and the steam with higher non-condensable gas concentration is directed without any obstruction towards the air cooling zone (7). The converging shape of tube bundle (12) is for improved heat transfer and aids improved cooling of the mixture of steam non-condensable gas. Proper cooling of the steam and non-condensable gas mixture reduces the volumetric flow rate to the gas evacuation device and ensures effective suction by the evacuation device connected through suction pipe located in the passage (11).
[0053] Referring to Figure 4, illustrating a cross sectional view of the cooling tube bundles (12) and shell with horizontal with flow entry and exit flow passages configuration. This figure explains different zones of heat transfer in cooling tube bundles (12) arranged as present invention which has features for promoting better deaeration of condensate. A plurality of cooling tubes (1) arranged in bundles (12) of the said cooling tube nest is configured in horizontal segments has cross flow condensate and steam flow path. This feature helps in condensate heating and consequent liberation of non-condensable from the condensate. The vent lanes (4) as described above contribute for deaeration of the condensate before falling on to the condensate outlet (8).
[0054] Referring to Figure 5, illustrating a cross sectional view of overall layout of condenser with tube nest and internals. One tube nest as described above can be used as single section condenser or two such tube nests as mirror image to each other can be used are double section condenser.
[0055] The material above has been given as an example without restricting scope of the invention to the same. Thus, other materials readily apparent to a person skilled in the art are understood to be within scope of the invention.

WORKING OF INVENTION

[0056] The working of the invention is described below:
[0057] The steam lines are arranged in a manner so as to have equitable distribution of steam at all cooling tubes of the condenser. The steam condenses on these tubes and dissolved oxygen and non-condensable are liberated. The unique arrangement of this invention ensures that these liberated gases move towards the air cooling zone. This is done by arranging the condenser internals to provide equal pressure for steam to be distributed over all cooling tubes. air cooling zone is sized and placed at the optimum location to remove the gases liberated.

ADVANTAGES OF THE INVENTION

1. The advantage of present invention is that it equalised steam distribution.
2. Another advantage of present invention is that it is used to prevent air pocket formation.
3. Further another advantage of present invention is that it provides optimum pressure drop across bundle of different sections and better utilisation of tube sheet area.

TEST RESULT

[0058] The invention will be offered as part of a commercial axial steam condenser package to a power plant installation. After commissioning, the axial steam condenser will be instrumented to obtain back pressure and other performance test parameters. The performance of the invention in the overall system can be measured by means of high precision pressure gages with a small operating range. This unique tube nest arrangement for two-pass axial condenser is expected to provide desired results, based on analytical computations. These test results will also form a basis for further design modifications or optimization.

[0059] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0060] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0061] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogue to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0062] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0063] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0064] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0065] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims: WE CLAIM
1. An axial circular two-pass steam condenser having tube nest layout, for power plant or chemical plant application, the condenser comprising:
a steam inlet (9), to receive steam in the condenser;
a plurality of cooling tubes (1), arranged on a tube plate (2), for condensing steam received through the steam inlet (9);
a plurality of vent lanes (4), to guide the steam with high concentration of non-condensable gases towards an air cooling zone (7);
a plurality of baffle plates (6, 6a), to guide the steam with high gas concentration towards a gas evacuation pipe located in a gas evacuation passage (11) for gas evacuation by an evacuation device;
a plurality of bundles (12), arranged in array before the gas evacuation passage (11) in a horizontal fashion; and
a condensate outlet hot well (8), to discharge condensate condensed in the plurality of cooling tubes (1);
wherein the tube nest design provides uniform and even steam distribution to all the sections of the bundles (12) and approximately 5-7% steam to air cooling zone (7).
2. The axial circular two-pass steam condenser as claimed in claim 1, wherein a vessel (10) surrounds the tube nest of the plurality of cooling tubes (1) having the steam inlet (9) at the entry and condensate outlet hot well (8) at the exit.
3. The axial circular two-pass steam condenser as claimed in claim 1 to 2, wherein the steam lanes (3) are formed in such a way that the steam quantity drawn is in proportion to the total number of cooling tubes (1) in the respective bundles (12) located at different sections.
4. The axial circular two-pass steam condenser as claimed in claim 1 to 3, wherein the shape of steam lane (3) is converging in nature to maintain the required steam velocity through the steam lanes (3).
5. The axial circular two-pass steam condenser as claimed in claim 1 to 4, wherein the tube bundles (12) are designed and arranged as mirror image of horizontal section A-A through the center line of the gas evacuation pipe.
6. The axial circular two-pass steam condenser as claimed in claim 1 to 5, wherein the shape of tube bundles (12) is converging in nature.
7. The axial circular two-pass steam condenser as claimed in claim 1-6, wherein one tube nest is used in single section condenser or two such tube nests as mirror image to each other are used in double section condenser.