Patent Description:
The present disclosure relates to a connection tube support of a waste heat recovery boiler and a waste heat recovery boiler including the same. More particularly, the present disclosure relates to a connection tube support of a waste heat recovery boiler and a waste heat recovery boiler including the same, wherein the connection tube support supports a connection tube unit, which is disposed inside the waste heat recovery boiler and exchanges heat between a fluid flowing inside and exhaust gas flowing outside.

In general, a waste heat recovery boiler constitutes, together with a gas turbine system and a steam turbine system, a combined power generation system. The waste heat recovery boiler is often used as a subsidiary system to recover the heat of the combustion gas exhausted after driving the gas turbine and drive the steam turbine again.

Such a waste heat recovery boiler is called a heat exchanger together with a nuclear steam generator, a feed water heater, a condenser, an evaporator, and the like and, as shown in <FIG>, has therein a support frame <NUM>, a fin tube <NUM>, a fin tube support <NUM>, a header <NUM>, and the like. Here, the fin tube <NUM> is designed to facilitate heat exchange by allowing fluids with different materials and temperatures to flow inside and outside of it, respectively. To create a block, hundreds to thousands of these fin tubes are assembled.

Due to the presence of high-flow energy, the combustion gas passing through the inside of the fin tube 10requires rigid attachment to the header <NUM>. This prevents any potential damage caused by vibration waves generated by the internal flow of the combustion gas. The header <NUM> serves to collect the combustion gas flowing in through the fin tube <NUM>.

Here, given the considerable length of the fin tube <NUM>, the fin tube support <NUM> is installed on the inner wall surface of a boiler body to securely fix the fin tube <NUM> at an intermediate position along its length. The fin tube support <NUM> has a plurality of insertion holes <NUM> that allow the fin tube <NUM> to pass through and be securely fixed in please.

When the fin tube <NUM> vibrates due to the internal flow of the combustion gas or thermal deformation occurs in the fin tube <NUM> due to high temperature and high pressure of the combustion gas during the operation of the waste heat recovery boiler, a phenomenon can occur where the fin <NUM> becomes restricted and caught on the fin tube support <NUM> as shown in <FIG>. This can lead to local buckling as shown in <FIG>. Since the fin tube <NUM> is inserted tightly into the hole <NUM> and supported to prevent movement, these constraints contribute to the occurrence of such phenomena. Therefore, several issues may arise, including breakage in the fin tube support <NUM>, cracks in the welded portion between the fin tube <NUM> and the header <NUM>, and thermal separation within the fin tube <NUM> itself.

Meanwhile, in the related art, when the vibration and thermal deformation occur in the.

fin tube <NUM>, the above problems have been solved by drilling the insertion hole <NUM> to be a little larger than the diameter of the fin tube <NUM>, so that the fin tube <NUM> may move in an axial direction through the inner space of the insertion hole <NUM> as shown in <FIG>. However, there has occurred a problem in that supporting force for supporting the fin tube <NUM> is inhibited due to the insertion hole <NUM> being drilled larger than the diameter of the fin tube <NUM>.

<CIT> discloses a boiler. The boiler has two horizontal rows of steel tubes with steel fins staggered with respect to each other and extending between tube sheets. Headers are associated with the tube sheets to provide multiple passes. The tube sheets are in sections having joints between the sections so that the tube sheets are articulated to allow freedom of axial expansion relatively of tubes in respective passes to prevent failure at tube ends. The tubes are copper lined and the faces of tubes sheets within headers are copper clad with copper inserts joining ends of copper tube linings with copper claddings.

<CIT> discloses a heat exchanger. The heat exchanger includes a plurality of heat exchange tubes arranged into a first row of tubes and a second row of tubes. A fixed mount fixedly positions the first row of tubes, and a movable mount makes the second row of tubes movable between an aligned position in which tubes in the second row are aligned with tubes in the first row, creating a linear flow path for the fluid through the tubes, and a non-aligned position in which tubes in the second row are not aligned with tubes in the first row, creating a curvilinear flow path for the fluid through the plurality of tubes. Heat is exchanged between the first fluid and a second fluid passing through the plurality of heat exchange tubes. The heat exchanger may be employed as an HRSG in a combined cycle plant, among other applications.

Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and an objective of the present disclosure is to provide a connection tube support of a waste heat recovery boiler and a waste heat recovery boiler including the same, which are capable of stably supporting a connection tube preventing damage to the connection tube due to the motion even in situations of thermal-expansion-induced movements of the connection tube through which a fluid flows exchanging heat with exhaust gas and of a tube sheet supporting the connection tube.

In order to achieve the above objective, according to the present disclosure, there may be provided a connection tube support of a waste heat recovery boiler supporting a connection tube unit having a plurality of connection tubes that is disposed inside a waste heat recovery boiler and performs heat exchange between a fluid flowing inside and exhaust gas flowing outside, the connection tube support including: a header storing fluid flowing through the connection tube unit and supporting one end of the connection tube unit.

by being connected to one end of the connection tube unit; and a tube sheet supporting a circumferential surface of each of the plurality of connection tubes, wherein the tube sheet may have the plurality of connection tubes passing therethrough and be provided with a plurality of support holes respectively supporting circumferential surfaces of the plurality of connection tubes passing therethrough. Each of the support holes is in a long-hole shape. wherein a width (W) of each of the support holes is W=D+a compared with an outer diameter (D) of each of the connection tubes, wherein a length (L) of each of the support holes is longer than the outer diameter (D) of each of the connection tubes, wherein the length (L) of each of the support holes is D≤L≤bD compared with the outer diameter (D) of each of the connection tubes, wherein a range of "a" may be <NUM>mm≤a≤<NUM>mm, and a range of "b" may be <NUM> ≤b≤<NUM>.

In the connection tube support of a waste heat recovery boiler according to the present disclosure, the header and the tube sheet may be installed on an inner wall of a casing part of the waste heat recovery boiler.

A plurality of the tube sheets may be installed to be spaced apart from each other in a longitudinal direction of the connection tube unit.

When the tube sheet pertains to a condition of moving in an upper direction according to a thermal expansion analysis thereon, the connection tube may be positioned on an upper side part of the support hole.

When the tube sheet pertains to a condition of moving in upper and lower directions according to a thermal expansion analysis thereon, the connection tube may be positioned in a central part of the support hole.

When the tube sheet pertains to a condition of moving in a lower direction according to a thermal expansion analysis thereon, the connection tube may be positioned on a lower side part of the support hole.

The plurality of support holes may be disposed in a plurality of rows on the tube sheet.

A first row and a second row may be adjacent to each other.

The plurality of support holes in a second row may be positioned between the plurality of support holes in the first row.

Wherein a plurality of support holes may be provided in a third row which is adjacent to the second row.

The plurality of support holes in the third row may be positioned on the same line as the plurality of support holes in the first row.

A plurality of support holes may be provided in a fourth row which is adjacent to the third row.

The plurality of support holes in the fourth row may be positioned on the same line as the plurality of support holes in the second row.

In addition, there may be provided a waste heat recovery boiler, the boiler including: a casing part providing a flow path through which exhaust gas flows; a connection tube unit disposed inside the casing part and having a plurality of connection tubes provided to be perpendicular to a flow direction of the exhaust gas inside the casing part, the connection tube unit configured to perform heat exchange between a fluid flow inside the connection tube unit and the exhaust gas; and a connection tube support supporting the connection tube unit that is disposed inside the casing part and exchanges heat with a fluid flowing inside and exhaust gas flowing outside, wherein the connection tube support may include: a header storing fluid flowing through the connection tube unit and supporting one end of the connection tube unit by being connected to one end of the connection tube unit; and a tube sheet supporting a circumferential surface of each of the plurality of connection tubes, wherein the tube sheet may have the plurality of connection tubes passing therethrough and be provided with a plurality of support holes respectively supporting circumferential surfaces of the plurality of connection tubes passing therethrough.

As described above, according to a connection tube support of a waste heat recovery boiler and a waste heat recovery boiler including the same, even when a motion of the connection tube through which a fluid that exchanges heat with exhaust gas flows and a tube sheet supporting the connection tube occurs due to thermal expansion, the connection tube can be stably supported while flexibility for the motion thereof is secured by the long hole-shaped support hole provided in the tube sheet.

The above and other objectives, features, and other advantages of the present invention will be more clearly understood from the following detailed description when taken in conjunction with the accompanying drawings, in which:.

Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Prior to this, it is noted that terms or words used in the present specification and claims should not be construed as being limited to the usual or dictionary meaning because, on the basis of the principle that the inventor may define the concept of the terms in order to explain his/her invention in the best way, the terms and words should be interpreted as meaning and concept consistent with the technical idea of the present disclosure.

With reference to <FIG>, a waste heat recovery boiler <NUM> according to an embodiment of the present invention includes a casing part <NUM>, a connection tube unit <NUM>, and a connection tube support <NUM>, wherein the casing part <NUM> has a substantially cubic shape and provides a flow path through which exhaust gas flows.

The casing part <NUM> is provided inside thereof with the connection tube unit <NUM> composed of a plurality of connection tubes disposed in a direction perpendicular to the flow direction of exhaust gas, wherein the plurality of connection tubes <NUM> included in the connection tube unit <NUM> is partitioned into a plurality of sections, and the plurality of connection tubes <NUM> partitioned above is classified into superheaters, evaporators, and the like according to the roles thereof.

The casing part <NUM> includes casings <NUM> and a thermal expansion absorbing member <NUM>. The casing part <NUM> includes at least two casings <NUM> separated from each other, and the casings <NUM> separated from each other may be connected by the mediation of the thermal expansion absorbing member <NUM> capable of absorbing deformation due to thermal expansion.

One side of the casing <NUM> may be provided with a gas inlet 1100a through which the exhaust gas of a gas turbine (not shown) is introduced, and an opposite side may be provided with a gas outlet 1100b for discharging the exhaust gas into the atmosphere.

The casing <NUM> may be provided in a metallic material, thereby being able to be thermally expanded by high-temperature exhaust gas, and the thermal expansion absorbing member <NUM> is configured to have fluidity in order to mitigate the thermal expansion of the casings <NUM> separated from each other.

With reference to <FIG> and <FIG>, the connection tube unit <NUM>, provided inside the casing part <NUM> and perpendicular to the exhaust gas flow direction, is supported by the connection tube support <NUM>. The connection tube support <NUM> includes a header <NUM> and a tube sheet <NUM>. In <FIG> and <FIG>, the direction in which the exhaust gas flows from the bottom to the top of the thermal expansion absorbing member <NUM> may be referred to as an upper direction or an upward direction and a direction opposite to the upper direction may be referred to as a lower direction or a downward direction. The upward and the downward directions may be referred to as a vertical direction, collectively.

The header <NUM> stores the fluid that flows through the connection tube <NUM> of the connection tube unit <NUM>. It is connected to one end of the connection tube <NUM>, providing support for that one end of the connection tube <NUM>. The header <NUM> may be installed on an inner wall surface of the casing part <NUM>.

The tube sheet <NUM> supports a plurality of connection tubes <NUM>, with their one ends connected to the header <NUM>. The tube sheet <NUM> is designed to have the plurality of connection tubes <NUM> pass through it, and it is provided with a plurality of support holes <NUM>. These support holes <NUM> are specifically positioned to support circumferential surfaces of the plurality of connection tubes <NUM> as they pass through the tube sheet <NUM>. The plurality of support holes <NUM> provided in the tube sheet <NUM> supports circumferential surfaces of the plurality of connection tubes <NUM>, respectively, and a plurality of tube sheets <NUM> is installed to be spaced apart from each other in a longitudinal direction of the plurality of connection tubes <NUM>. Each of the plurality of tube sheets <NUM> may be generally in a form of a flat plane, disposed parallel to the upper and the lower directions.

With reference to <FIG>, the plurality of support holes <NUM> provided in the tube sheet <NUM> has a long hole shape, where its length is in the upper and lower directions and is larger than its width. The width of the long hole shape is in a perpendicular direction to the upper and the lower directions. The width W of the support hole <NUM> is larger than an outer diameter D of the connection tube having the width W being W=D+a. According to the invention, the range of a may be <NUM>mm≤a≤<NUM>mm. In addition, the length L of the support hole <NUM> is larger than the outer diameter D of the connection tube <NUM>. In addition, the length L of the support hole may be D≤L≤bD compared with the outer diameter D of the connection tube. According to the invention, an the range of b may be <NUM> ≤b≤<NUM>, in other words, L being larger than D by <NUM> times to <NUM> times.

When the length L of the support hole <NUM> is longer than the outer diameter D of the connection tube <NUM> by greater than <NUM> times, an impact caused by the flow of the tube sheet <NUM> may be transferred to the connection tube <NUM>, and the connection tube <NUM> may be damaged. In the case in which the length L of the support hole <NUM> is equal to the outer diameter of the connection tube <NUM>, when the tube sheet <NUM> flows due to thermal expansion, a problem that can occur is that the connection tube <NUM> flows together.

With reference to <FIG>, the position of the connection tube <NUM> inserted into the support hole <NUM> of the tube sheet <NUM> may be adjusted according to the thermal expansion analysis of the tube sheet <NUM> supporting the connection tube <NUM>. As a result of the thermal expansion analysis, the tube sheet <NUM> may pertains to a condition of moving in the upward direction, in other words, may be expected to move in the upward direction under the thermal expansion. Instead, as the result of the thermal expansion analysis, the tube sheet <NUM> may pertain to a condition of moving in the downward direction, in other words, may be expected to move in the downward direction under the thermal expansion. Still instead, as the result of the thermal expansion analysis, the tube sheet <NUM> may pertain to a condition of moving both in the upward and downward direction, in other words, may be expected to move both in the upward and downward direction under the thermal expansion. According to such analysis, the position of insertion of a connection tube <NUM> into a corresponding support hole <NUM> may be adjusted before the thermal expansion.

For example, when the tube sheet <NUM> pertains to a condition of moving in an upper direction according to the thermal expansion analysis, the connection tube <NUM> may be positioned on an upper side part of the support hole <NUM> (see <FIG>). In other words, when the position of the support holes <NUM> are expected to change upward during thermal expansion of the tube sheet <NUM>, the connection tube <NUM> may be inserted into the support hole before the thermal expansion such that the connection tube <NUM> may be positioned on an upper side part of the support hole <NUM>.

When the connection tube <NUM> is inserted to be positioned on the upper side part of the support hole <NUM> provided in the tube sheet <NUM> before the thermal expansion, a space is secured at a lower part of the support hole <NUM>. This arrangement helps eliminate any potential constraints that may occur when the tube sheet <NUM> and the support holes <NUM> therein moves upward during thermal expansion.

When the tube sheet <NUM> pertains to a condition of moving in a lower direction according to the thermal expansion analysis, the connection tube <NUM> may be positioned on a lower side part of the support hole <NUM> (see <FIG>). In other words, when the position of the support holes <NUM> is expected to change downward during thermal expansion of the tube sheet <NUM>, the connection tube <NUM> may be inserted into the support hole before the thermal expansion such that the connection tube <NUM> may be positioned on a lower side part of the support hole <NUM>.

When the connection tube <NUM> is inserted to be positioned on the lower side part of the support hole <NUM> provided in the tube sheet <NUM> before the thermal expansion, a space is secured at the upper part of the support hole 1321This arrangement helps eliminate any potential constraints that may occur when the tube sheet <NUM> and the support holes <NUM> therein moves downward during thermal expansion.

When the tube sheet <NUM> pertains to a condition of moving in the upper and lower directions according to the thermal expansion analysis, the connection tube <NUM> may be positioned in a central part of the support hole <NUM> (see <FIG>). In other words, in this case, the connection tube <NUM> may be inserted into the support hole before the thermal expansion such that the connection tube <NUM> may be positioned in a central part of the support hole <NUM>.

In this case, a space is secured at both of upper and lower parts of the support hole <NUM>, whereby constraining conditions may be removed that may occur during thermal expansion.

With reference to <FIG>, the plurality of support holes <NUM> may be disposed in a plurality of rows on the tube sheet <NUM>. The plurality of rows may be arranged along the vertical direction. In each row, a plurality of support holes <NUM> are present, and they may be uniformly spaced apart from each other at equal same intervals. When the tube sheet <NUM> is erected and installed inside the casing part <NUM>, and when the first row is adjacent to the second row, a plurality of support holes <NUM> in a second row are positioned between the plurality of support holes <NUM> in the first row.

Furthermore, when the third row is adjacent to the second row, the plurality of support holes <NUM> in the third row is positioned on the same line as the plurality of support holes <NUM> in the first row in the vertical direction, and when the fourth row is adjacent to the third row, a plurality of support holes <NUM> in a fourth row is positioned on the same line as the plurality of support holes <NUM> in the second row in the vertical direction.

Out of the plurality of support holes <NUM> disposed in the plurality of rows in the tube sheet <NUM>, a plurality of odd-numbered support holes <NUM> is positioned on the same line in the vertical direction, and a plurality of even-numbered rows of support holes <NUM> is positioned between and in the middle of the odd-numbered rows of support holes <NUM>, whereby on the tube sheet <NUM>, the plurality of odd-numbered and even-numbered support holes <NUM> is arranged in a zigzag shape. As a result of this arrangement, smooth heat exchange occurs between the exhaust gas flowing into the casing part <NUM> and the fluid moving through the plurality of connection tubes <NUM>. The positioning and spacing of the support holes in the tube sheet <NUM> allow for efficient and effective heat exchange between the two mediums.

Furthermore, the long hole-shaped support holes <NUM> provided in the tube sheet <NUM> enables stable support of the connection tube <NUM> while maintain flexibility to accommodate the thermal expansion-induced motion of the connection tube <NUM> and the tube sheet <NUM>. This design feature allows the connection tube <NUM>, through which heat-exchanging fluid flow and exchanges heat with exhaust gas, to be effectively supported and ensure its motion is accommodated without compromising stability.

Claim 1:
A connection tube support (<NUM>) of a waste heat recovery boiler (<NUM>) supporting a connection tube unit (<NUM>) having a plurality of connection tubes (<NUM>) that is disposed inside a waste heat recovery boiler (<NUM>) and perform heat exchange between a fluid flowing inside and exhaust gas flowing outside, the connection tube support (<NUM>) comprising:
a header (<NUM>) storing fluid flowing through the connection tube unit (<NUM>) and supporting one end of the connection tube unit (<NUM>) by being connected to one end of the connection tube unit (<NUM>); and
a tube sheet (<NUM>) supporting a circumferential surface of each of the plurality of connection tubes (<NUM>),
wherein the tube sheet (<NUM>) has the plurality of connection tubes (<NUM>) passing therethrough and is provided with a plurality of support holes (<NUM>) respectively supporting circumferential surfaces of the plurality of connection tubes (<NUM>) passing therethrough, wherein each of the support holes (<NUM>) is in a long hole shape,
characterized in that
a width (W) of each of the support holes (<NUM>) is W=D+a compared with an outer diameter (D) of each of the connection tubes (<NUM>), and a length (L) of each of the support holes (<NUM>) is longer than the outer diameter (D) of each of the connection tubes (<NUM>),
wherein the length (L) of each of the support holes (<NUM>) is D≤L≤bD compared with the outer diameter (D) of each of the connection tubes (<NUM>), the range of "a" is <NUM>mm≤a≤<NUM>mm, and the range of "b" is <NUM>≤b≤<NUM>.