heat exchanger

Abstract

To provide a heat exchanger that improves the maintainability of heat transfer tubes. [Solution] The heat exchanger includes a group of heat transfer tubes through which a heat exchange medium flows, a group of holders that hold one or more of the heat transfer tubes, a guide that movably supports at least a portion of the group of holders, a header that is connected to and fixedly positioned in communication with the group of heat transfer tubes, and a stress reduction structure that is positioned at the connection point between the header and the heat transfer tubes and reduces the stress generated in the heat transfer tubes when the holders move.

Description

Technical Field

[0001] The present disclosure relates to a heat exchanger.

Background Art

[0002] For example, Patent Document 1 discloses a vertical heat exchanger that exchanges heat for exhaust gas containing fine dust. The vertical heat exchanger includes a plurality of serpentine heat transfer tubes including straight pipe portions, and a plurality of pairs of first suspension means and second suspension means for suspending two serpentine heat transfer tubes. A hammering device is hinge-connected to a bent portion of a hinge structure included in the first suspension means. The hammering device vibrates the heat transfer tube by applying a blow to shake off the dust adhering to the heat transfer tube.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] With only the vibration by the hammering device, the adhered dust may remain on the heat transfer tube. Such dust may accumulate and adhere. However, in Patent Document 1, since a plurality of serpentine heat transfer tubes are densely arranged, it is difficult to remove the remaining dust. The present disclosure provides a heat exchanger that improves the maintainability of the heat transfer tube.

Means for Solving the Problems

[0005] A heat exchanger according to one aspect of the present disclosure includes a group of heat transfer tubes through which a heat exchange medium flows, a plurality of holders for holding one or more of the heat transfer tubes, a guide for movably supporting at least a portion of the plurality of holders, a header connected to and fixedly positioned in communication with the plurality of heat transfer tubes, and a stress reduction structure disposed at the connection portion between the header and the heat transfer tubes, for reducing stress generated in the heat transfer tubes when the holders move. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows an example of the configuration of a device including a heat exchanger according to an exemplary embodiment. [Figure 2] Figure 2 is a side view showing an example of the configuration of a heat exchanger according to an embodiment. [Figure 3] Figure 3 is a side view showing an example of the configuration of a heat exchanger, viewed from a different direction than in Figure 2. [Figure 4] Figure 4 is an enlarged view of the heat transfer tube in Figure 2. [Figure 5] Figure 5 is a side view showing an example of the structure of the heat transfer tube in Figure 4. [Figure 6] Figure 6 is an enlarged view of the first retaining portion of the first retainer shown in Figure 3. [Figure 7] Figure 7 is a side view showing an example of a stress reduction structure according to an embodiment. [Figure 8] Figure 8 is a side view showing a modified example of the stress reduction structure, similar to Figure 7. [Modes for carrying out the invention]

[0007] Illustrative embodiments of the present disclosure will be described below with reference to the drawings. The embodiments described below are all comprehensive or specific examples. Among the components in the following embodiments, those components that are not described in the independent claim representing the highest-level concept will be described as optional components. The figures in the accompanying drawings are schematic and not necessarily strictly illustrative. In each figure, substantially identical components are denoted by the same reference numerals, and redundant descriptions may be omitted or simplified. In this specification and claims, “apparatus” can mean not only one apparatus but also a system comprising multiple apparatuses. “Apparatus” can also include “equipment.”

[0008] Referring to Figure 1, the configuration of the apparatus 1 including a heat exchanger 100 according to an exemplary embodiment will be described. Figure 1 is a diagram showing an example of the configuration of the apparatus 1 including a heat exchanger 100 according to an exemplary embodiment. The apparatus 1 only needs to include a heat exchanger 100, and more specifically, it needs to include a heat exchanger 100 that exchanges heat with a gas containing dust. In this embodiment, the apparatus 1 is a facility, and more specifically, a plant. Examples of plant 1 may include industrial plants, chemical plants, and environmental plants. Examples of industrial plants may include food processing plants, pharmaceutical plants, steel mills, cement mills, and power plants. Examples of chemical plants may include chemical plants, petrochemical plants, petroleum refineries, and gas refineries. Examples of environmental plants may include waste treatment plants and sewage treatment plants.

[0009] This embodiment will be described using the example that Plant 1 is a waste treatment plant. Plant 1 is an incineration plant that incinerates waste. Plant 1 includes an incinerator 11, a boiler 12, a dust collector 13, a nitrogen oxide removal device 14, and a chimney 15. Plant 1 does not have to include one or more of the above components, and may include additional components in addition to the above components. Examples of further components may include a power generator, a cooling tower, a blower, equipment for chemicals that treat exhaust gas, an exhaust gas cleaning device that removes acidic gases and heavy metals from the exhaust gas, a storage tank for storing fuel or waste, and a crane for transferring fuel or waste from the storage tank to the incinerator 11.

[0010] The incinerator 11 receives fuel or waste containing biomass from the hopper 11a and incinerates them using oxygen-containing gas. The exhaust gas, which is the combustion gas generated in the incinerator 11, is sent to the boiler 12.

[0011] The boiler 12 includes a radiating chamber 121, a drum 122, a superheater 123, and an economizer 124. In this embodiment, the boiler 12 further includes an evaporator 125, although the evaporator 125 is not essential to the boiler 12. The radiating chamber 121 is located furthest upstream in the flow direction of the exhaust gas in the boiler 12 and allows the high-temperature exhaust gas sent from the incinerator 11 to flow through it. The radiating chamber 121 includes water-walled tubes in its surrounding walls. The water-walled tubes receive radiant heat from the high-temperature exhaust gas, causing water to evaporate and lowering the temperature of the exhaust gas.

[0012] In this embodiment, the radiation chamber 121 includes a first radiation chamber 121a and a second radiation chamber 121b. The first radiation chamber 121a is located upstream of the second radiation chamber 121b in the direction of exhaust gas flow and forms a flow path that guides the exhaust gas sent from the incinerator 11 from bottom to top in the direction of gravity. The second radiation chamber 121b communicates with the upper part of the first radiation chamber 121a and forms a flow path that guides the exhaust gas sent from the first radiation chamber 121a from top to bottom in the direction of gravity.

[0013] The evaporator 125 is located in the second radiating chamber 121b. The evaporator 125 includes a heat exchanger that exchanges heat between water, which is used as a heat exchange medium, and the exhaust gas. The water flows through heat transfer tubes contained in the heat exchanger. The exhaust gas rising successively in the first radiating chamber 121a forms a forced flow of exhaust gas in the second radiating chamber 121b. The evaporator 125 evaporates the water in the heat exchanger through convective heat transfer from the forcibly flowing exhaust gas and sends the mixture of water and steam to the drum 122. The evaporator 125 lowers the temperature of the exhaust gas through heat exchange between the exhaust gas and the water in the heat exchanger.

[0014] The drum 122 is positioned adjacent to the first radiating chamber 121a on the downstream side in the direction of exhaust gas flow. For example, the drum 122 may be positioned adjacent to the second radiating chamber 121b on the upstream side in the direction of exhaust gas flow. The drum 122 separates the steam from the mixture of water and steam supplied from the water wall tube and evaporator 125, and sends the separated steam to the superheater 123. Saturated steam is supplied to the superheater 123.

[0015] The superheater 123 is located downstream of the second radiating chamber 121b in the direction of exhaust gas flow, and passes the exhaust gas through the second radiating chamber 121b. The superheater 123 superheats the saturated steam sent from the drum 122 by convective heat transfer from the exhaust gas, generating superheated steam. The superheater 123 includes a heat exchanger that exchanges heat between the exhaust gas and the saturated steam. The saturated steam flows through the heat transfer tubes contained in the heat exchanger. The superheated steam may be used to drive the turbine of the power generation device.

[0016] The economizer 124 is located downstream of the superheater 123 in the direction of exhaust gas flow and allows the exhaust gas that has passed through the superheater 123 to flow through it. The economizer 124 heats the water to be supplied to the drum 122 by convective heat transfer from the exhaust gas and sends the heated water to the drum 122. The exhaust gas that has passed through the economizer 124 is sent to the dust collector 13. The economizer 124 includes a heat exchanger that exchanges heat between the exhaust gas and the water. The water flows through heat transfer tubes contained in the heat exchanger. The economizer 124 is also called an economizer.

[0017] Although not limited, in the present embodiment, the economizer 124 includes the heat exchanger 100 according to the embodiment as a heat exchanger. The superheater 123 or the evaporator 125 may include the heat exchanger 100 according to the embodiment as a heat exchanger. One or more of the superheater 123, the economizer 124, and the evaporator 125 may include the heat exchanger 100 according to the embodiment.

[0018] In FIG. 1, in the boiler 12, the evaporator 125, the superheater 123, and the economizer 124 are arranged in this order in the exhaust gas flow direction, but the arrangement order of the evaporator 125, the superheater 123, and the economizer 124 is not limited to FIG. 1. For example, the superheater 123, the evaporator 125, and the economizer 124 may be arranged in this order in the exhaust gas flow direction.

[0019] The dust collector 13 removes dust contained in the exhaust gas from the exhaust gas. As the dust collector 13, a filtration type dust collector may be used. The exhaust gas after dust collection is sent to the nitrogen oxide removal device 14.

[0020] The nitrogen oxide removal device 14 removes nitrogen oxides (NOx) from the exhaust gas by supplying ammonia gas or aqueous ammonia to the exhaust gas. The exhaust gas after treatment in the nitrogen oxide removal device 14 is sent to the chimney 15 and discharged into the atmosphere from the chimney 15.

[0021] While referring to FIGS. 2 and 3, the configuration of the heat exchanger 100 according to the embodiment will be described. FIG. 2 is a side view showing an example of the configuration of the heat exchanger 100 according to the embodiment. FIG. 3 is a side view showing an example of the configuration of the heat exchanger 100 viewed from a direction different from FIG. 2. In FIGS. 2 and 3, there are components to which reference numerals are attached only to a part of the plurality of existing components.

[0022] The heat exchanger 100 includes a plurality of heat transfer tubes 110. Each heat transfer tube 110 includes a heat exchange section 111, a first connecting tube section 112, and a second connecting tube section 113. The heat exchange section 111 is located between the first connecting tube section 112 and the second connecting tube section 113 and communicates with the first connecting tube section 112 and the second connecting tube section 113. The heat exchange section 111 has a structure that increases the contact area with the exhaust gas to be heat exchanged. In this embodiment, however not limited, the heat exchange section 111 includes a tube that extends in a meandering manner to repeatedly reciprocate and has the shape of a meandering tube. The heat exchange section 111, the first connecting tube section 112, and the second connecting tube section 113 form a single continuous tube. The heat exchange section 111, the first connecting tube section 112, and the second connecting tube section 113 have the same diameter.

[0023] As shown in Figure 4, the heat exchange section 111 includes a plurality of straight pipe sections 111a and a plurality of curved pipe sections 111b. Figure 4 is an enlarged view of the heat transfer tube 110 in Figure 2. In this embodiment, however not limited, the plurality of straight pipe sections 111a extend in a first direction D1 and are parallel to each other. The direction opposite to the first direction D1 is the second direction D2. The plurality of straight pipe sections 111a are aligned in a third direction D3, which is the direction intersecting the first direction D1. In this embodiment, however not limited, the third direction D3 is perpendicular to the first direction D1. The direction opposite to the third direction D3 is the fourth direction D4.

[0024] Some of the multiple curved pipe sections 111b connect the ends in the first direction D1 of two straight pipe sections 111a that are adjacent to each other in the third direction D3. Other parts of the multiple curved pipe sections 111b connect the ends in the second direction D2 of two straight pipe sections 111a that are adjacent to each other in the third direction D3. In this embodiment, however, the curved pipe sections 111b have an arc-shaped pipe form, but may also include bent portions.

[0025] As shown in Figure 5, in this embodiment, the heat transfer tube 110 is a finned tube. Figure 5 is a side view showing an example of the structure of the heat transfer tube 110 in Figure 4. In Figure 5, there are some components for which only some of the multiple components are given reference numerals. The heat transfer tube 110 includes a pipe section 110a and a fin section 110b extending around the pipe section 110a. Multiple annular plate-shaped fin sections 110b are arranged at intervals along the pipe section 110a. The fin sections 110b are integrated with the pipe section 110a. The shape of the fin sections 110b is not limited to an annular shape, but may be any shape including a spiral plate shape, other plate shapes, and protruding shapes. Such a heat transfer tube 110 increases the heat exchange area and improves the heat exchange efficiency. The fin sections 110b may be arranged on the straight pipe section 111a and also on the curved pipe section 111b.

[0026] In this specification and claims, “parallel” may include “perfectly parallel” and “substantial parallel” which can be considered parallel. “Perpendicular” may include “perfectly perpendicular” and “substantial perpendicular” which can be considered perpendicular. “Orthogonal” may include “perfectly orthogonal” which can be considered orthogonal. “Vertical” may include “perfectly vertical” and “substantial vertical” which can be considered vertical. “Horizontal” may include “perfectly horizontal” which can be considered horizontal.

[0027] In this embodiment, however not limited thereto, as shown in Figure 4, the multiple heat transfer tubes 110 are arranged such that the third direction D3 is along the vertical direction and the first connecting tube section 112 is located above the second connecting tube section 113. The heat exchange medium, water, flows in from the first connecting tube section 112 and flows out from the second connecting tube section 113. The first connecting tube section 112 is connected to a straight tube section 111a or a curved tube section 111b, and the second connecting tube section 113 is connected to a straight tube section 111a or a curved tube section 111b. In this embodiment, the third direction D3 is the direction downward in the direction of gravity, and the fourth direction D4 is the direction upward in the direction of gravity.

[0028] The first connecting pipe section 112 extends in a direction different from that of the heat exchange section 111, and in a direction different from that of the straight pipe section 111a or curved pipe section 111b to which the first connecting pipe section 112 is connected. In this embodiment, however, the first connecting pipe section 112 extends from the heat exchange section 111 toward a fourth direction D4. The heat transfer tube 110 may include a bent portion at the connection point between the first connecting pipe section 112 and the heat exchange section 111, including a bent shape, a curved shape, or a combination thereof.

[0029] The second connecting pipe section 113 extends in a direction different from that of the heat exchange section 111, and in a direction different from that of the straight pipe section 111a or curved pipe section 111b to which the second connecting pipe section 113 is connected. In this embodiment, however, the second connecting pipe section 113 extends from the heat exchange section 111 toward a third direction D3. The heat transfer tube 110 may include a bent portion at the connection point between the second connecting pipe section 113 and the heat exchange section 111, including a bent shape, a curved shape, or a combination thereof.

[0030] As shown in Figures 2 and 3, the multiple heat transfer tubes 110 are divided into two or more groups, and in this embodiment, they are divided into two groups. The heat transfer tubes 110 included in the first heat transfer tube group G1, which is the first group, may be referred to as "heat transfer tube 110A", and the heat transfer tubes 110 included in the second heat transfer tube group G2, which is the second group, may be referred to as "heat transfer tube 110B". The first connecting pipe section 112, heat exchange section 111, and second connecting pipe section 113 of heat transfer tube 110A may be referred to as "first connecting pipe section 112A", "heat exchange section 111A", and "second connecting pipe section 113A", respectively. The first connecting pipe section 112, heat exchange section 111, and second connecting pipe section 113 of heat transfer tube 110B may be referred to as "first connecting pipe section 112B", "heat exchange section 111B", and "second connecting pipe section 113B", respectively. The first connecting pipe section 112B may be included in the second connecting pipe section 113A, and the second connecting pipe section 113A may be included in the first connecting pipe section 112B.

[0031] Multiple heat transfer tubes 110A are positioned above multiple heat transfer tubes 110B, i.e., in the fourth direction D4. Multiple heat transfer tubes 110A are positioned away from multiple heat transfer tubes 110B. In this embodiment, however, the number of heat transfer tubes 110A is the same as the number of heat transfer tubes 110B. The second connecting pipe section 113A of each of the multiple heat transfer tubes 110A is connected to the first connecting pipe section 112B of the multiple heat transfer tubes 110B. For example, the second connecting pipe section 113A of heat transfer tube 110A is connected to the first connecting pipe section 112B of heat transfer tube 110B which is located in the third direction D3 relative to heat transfer tube 110A. Heat transfer tubes 110A and 110B connected by the second connecting pipe section 113A and the first connecting pipe section 112B are aligned in the third direction D3.

[0032] For heat transfer tube 110A, the heat exchange section 111A is an example of the first tube section, and the first connecting tube section 112A is an example of the second tube section. For heat transfer tube 110B, the heat exchange section 111B is an example of the fourth tube section, and the second connecting tube section 113B is an example of the fifth tube section. The second connecting tube section 113A of heat transfer tube 110A, the first connecting tube section 112B of heat transfer tube 110B, or a combination thereof, is an example of the third tube section.

[0033] Multiple heat transfer tubes 110A are arranged at intervals from each other in a fifth direction D5, which intersects with the first direction D1 and the third direction D3. In this embodiment, however, the fifth direction D5 is perpendicular to the first direction D1 and the third direction D3. The direction opposite to the fifth direction D5 is the sixth direction D6. In the multiple heat transfer tubes 110A, two adjacent heat transfer tubes 110 in the fifth direction D5 are arranged such that their respective straight tube portions 111a extend along each other, and in this embodiment, they extend parallel to each other.

[0034] Multiple heat transfer tubes 110B are arranged at intervals from each other in the fifth direction D5. In the multiple heat transfer tubes 110B, two adjacent heat transfer tubes 110 in the fifth direction D5 are arranged such that their respective straight tube portions 111a extend along each other, and in this embodiment, they extend parallel to each other.

[0035] The heat exchanger 100 further includes a plurality of first retainers 130, a plurality of second retainers 140, a first guide 150, and a second guide 160. Each first retainer 130 includes a first retaining portion 130A and a second retaining portion 130B. Each second retainer 140 includes a first retaining portion 140A and a second retaining portion 140B.

[0036] A pair of first and second holding parts 130A contained within a single first holder 130 holds two adjacent heat transfer tubes 110A in the fifth direction D5. The holding parts 130A and 130B hold the heat transfer tubes 110A in a suspended manner. The first holding part 130A holds the heat transfer tube 110A near the end of the straight tube section 111a in the first direction D1. The second holding part 130B holds the heat transfer tube 110A near the end of the straight tube section 111a in the second direction D2. The second holding part 130B is located in the second direction D2 relative to the first holding part 130A.

[0037] As shown in Figures 2, 3, and 6, the first holding portion 130A each includes a plurality of first support members 131A, a second support member 132A, and an engaging member 133A. Figure 6 is an enlarged view of the first holding portion 130A of the first holder 130 in Figure 3. In Figure 6, there are some components for which only some of the multiple components are given reference numerals. Each first support member 131A is connected to two adjacent straight pipe sections 111a in the fifth direction D5 between two adjacent heat transfer tubes 110A, near the ends in the first direction D1. The first support member 131A holds the two straight pipe sections 111a at a predetermined distance in the fifth direction D5. The plurality of first support members 131A are connected to each pair of adjacent straight pipe sections 111a in the fifth direction D5 between the two heat transfer tubes 110A, and are aligned in the third direction D3. The second support member 132A is connected to a plurality of first support members 131A arranged in the third direction D3, and holds the plurality of first support members 131A at predetermined intervals in the third direction D3.

[0038] The second support member 132A is slidably supported in directions D5 and D6 by guide members 151 and 152 of the first guide 150 near its end in the fourth direction D4. Guide members 151 and 152 are members that extend in the fifth direction D5 above the first holding portion 130A and slidably clamp the second support member 132A. In this embodiment, although not limited to these, guide members 151 and 152 are columnar members that extend in the fifth direction D5. The engaging member 133A is attached to the end of the second support member 132A that protrudes upward from the guide members 151 and 152, and functions as a stopper that prevents the downward movement of the second support member 132A by engaging with the guide members 151 and 152 from above. Guide members 151 and 152 slidably support at least a portion of the plurality of second support members 132A, and in this embodiment, they slidably support all of the plurality of second support members 132A.

[0039] Each second holding section 130B includes a plurality of first support members 131B, a second support member 132B, and an engaging member 133B. Each first support member 131B is connected to two adjacent straight pipe sections 111a in the fifth direction D5 between two adjacent heat transfer tubes 110A, near the end in the second direction D2. The first support members 131B hold the two straight pipe sections 111a at a predetermined interval in the fifth direction D5. The plurality of first support members 131B are connected to each pair of adjacent straight pipe sections 111a in the fifth direction D5 between the two heat transfer tubes 110A, and are aligned in the third direction D3. The second support member 132B is connected to the plurality of first support members 131B aligned in the third direction D3, and holds the plurality of first support members 131B at a predetermined interval in the third direction D3.

[0040] The second support member 132B is slidably supported in directions D5 and D6 by guide members 153 and 154 of the first guide 150 near its end in the fourth direction D4. Guide members 153 and 154 are members that extend in the fifth direction D5 above the second holding portion 130B and slidably clamp the second support member 132B. In this embodiment, however not limited thereto, guide members 153 and 154 are columnar members that extend in the fifth direction D5. The engaging member 133B is attached to the end of the second support member 132B that protrudes upward from the guide members 153 and 154 and functions as a stopper that prevents the downward movement of the second support member 132B by engaging with the guide members 153 and 154 from above. Guide members 153 and 154 slidably support at least a portion of the plurality of second support members 132B, and in this embodiment, they slidably support all of the plurality of second support members 132B.

[0041] Therefore, the first holder 130 holds the two heat transfer tubes 110A so that they can slide in directions D5 and D6 via the holding portions 130A and 130B.

[0042] A pair of first and second holding parts 140A and 140B contained within a single second holder 140 holds two adjacent heat transfer tubes 110B in the fifth direction D5. The holding parts 140A and 140B hold the heat transfer tubes 110B in a suspended manner. The first holding part 140A holds the heat transfer tube 110B near the end of the straight tube section 111a in the first direction D1. The second holding part 140B holds the heat transfer tube 110B near the end of the straight tube section 111a in the second direction D2. The second holding part 140B is located in the second direction D2 relative to the first holding part 140A. The first holding part 140A has a structure similar to that of the first holding part 130A, and the second holding part 140B has a structure similar to that of the second holding part 130B.

[0043] Each first holding portion 140A includes a plurality of first support members 141A, a second support member 142A, and an engaging member 143A, similar to the first holding portion 130A. Each second holding portion 140B includes a plurality of first support members 141B, a second support member 142B, and an engaging member 143B, similar to the second holding portion 130B.

[0044] Each of the multiple first support members 141A of the first holding section 140A holds the vicinity of the ends in the first direction D1 of two adjacent straight pipe sections 111a in the fifth direction D5 between two adjacent heat transfer tubes 110B, with a predetermined interval in the fifth direction D5. The multiple first support members 141A are connected to each pair of adjacent straight pipe sections 111a between the two heat transfer tubes 110B in the fifth direction D5, and are aligned in the third direction D3. The second support member 142A holds the multiple first support members 141A aligned in the third direction D3 with a predetermined interval in the third direction D3.

[0045] The second support member 142A is slidably held in directions D5 and D6 by guide members 161 and 162 of the second guide 160 near its end in the fourth direction D4. Guide members 161 and 162 extend in the fifth direction D5 above the first holding portion 140A. In this embodiment, however not limited, guide members 161 and 162 are columnar members extending in the fifth direction D5. The engaging member 143A is attached to the end of the second support member 142A in the fourth direction D4 and prevents the downward movement of the second support member 142A by engaging with guide members 161 and 162 from above. Guide members 161 and 162 slidably support at least a portion of the plurality of second support members 142A, and in this embodiment, they slidably support all of the plurality of second support members 142A.

[0046] Each of the multiple first support members 141B of the second holding section 140B holds the vicinity of the ends in the second direction D2 of two adjacent straight pipe sections 111a in the fifth direction D5 between two adjacent heat transfer tubes 110B, with a predetermined interval in the fifth direction D5. The multiple first support members 141B are connected to each pair of adjacent straight pipe sections 111a between the two heat transfer tubes 110B in the fifth direction D5, and are aligned in the third direction D3. The second support member 142B holds the multiple first support members 141B aligned in the third direction D3 with a predetermined interval in the third direction D3.

[0047] The second support member 142B is slidably held in directions D5 and D6 by guide members 163 and 164 of the second guide 160 near its end in the fourth direction D4. Guide members 163 and 164 extend in the fifth direction D5 above the second holding portion 140B. In this embodiment, however not limited, the guide members 163 and 164 are columnar members extending in the fifth direction D5. The engaging member 143B is attached to the end of the second support member 142B in the fourth direction D4 and prevents the downward movement of the second support member 142B by engaging with the guide members 163 and 164 from above. Guide members 163 and 164 slidably support at least a portion of the plurality of second support members 142B, and in this embodiment, they slidably support all of the plurality of second support members 142B.

[0048] Therefore, the second holder 140 holds the two heat transfer tubes 110B so that they can slide in directions D5 and D6 via the holding portions 140A and 140B.

[0049] As shown in Figures 2 and 3, the heat exchanger 100 further includes a first header 170, a second header 180, and a casing 190. The casing 190 houses at least heat transfer tubes 110A and 110B, holders 130 and 140, and guides 150 and 160. The casing 190 surrounds the heat transfer tubes 110A and 110B, the holders 130 and 140, and the guides 150 and 160 from directions D1, D2, D5, and D6. The exhaust gas sent from the superheater 123 to the economizer 124 flows through the casing 190 in the third direction D3.

[0050] The first header 170 is positioned in a fourth direction D4, above the multiple heat transfer tubes 110A. The first header 170 extends in a fifth direction D5 and is fixed in a fixed position. In this embodiment, however, the first header 170 is positioned inside the casing 190. The first header 170 may extend in a fifth direction D5 above the multiple heat transfer tubes 110A and across the entirety of the multiple heat transfer tubes 110A.

[0051] Each of the first connecting pipe sections 112A of the multiple heat transfer tubes 110A is connected to communicate with the first header 170. The first header 170 is connected to the water supply source to the drum 122 via piping. The first header 170 has a structure through which water flows. The first header 170 has a structure that distributes the water supplied from the supply source to the multiple heat transfer tubes 110A. For example, the first header 170 may have a tubular structure.

[0052] The second header 180 is positioned in a third direction D3, below the multiple heat transfer tubes 110B. The second header 180 extends in a fifth direction D5 and is fixed in a fixed position. In this embodiment, however, the second header 180 is positioned within the casing 190. The second header 180 may extend in a fifth direction D5 below the multiple heat transfer tubes 110B and across the entirety of the multiple heat transfer tubes 110B.

[0053] The second connecting pipe sections 113B of each of the multiple heat transfer tubes 110B are connected to communicate with the second header 180. The second header 180 is connected to the drum 122 via piping. The second header 180 has a structure through which water flows. The second header 180 has a structure that collects the water sent from the multiple heat transfer tubes 110B and supplies it to the drum 122. For example, the second header 180 may have a tubular structure.

[0054] The heat transfer tube 110A moves in directions D5 and D6 as the first holder 130 slides in directions D5 and D6. The heat transfer tube 110B moves in directions D5 and D6 as the second holder 140 slides in directions D5 and D6. The heat transfer tubes 110A and 110B, connected via the second connecting pipe section 113A and the first connecting pipe section 112B, can move independently of each other. The heat transfer tube 110A can move independently of the first header 170. The heat transfer tube 110B can move independently of the second header 180.

[0055] As the heat transfer tube 110A moves relative to the first header 170, stress is generated in one or more of the following: the first connecting tube section 112A, the connection between the first connecting tube section 112A and the first header 170, and the connection between the first connecting tube section 112A and the heat exchange section 111A.

[0056] As the heat transfer tube 110A moves relative to the heat transfer tube 110B connected to it, stress is generated in one or more of the following: the second connecting pipe section 113A, the first connecting pipe section 112B, the connection between the second connecting pipe section 113A and the heat exchange section 111A, the connection between the second connecting pipe section 113A and the first connecting pipe section 112B, and the connection between the first connecting pipe section 112B and the heat exchange section 111B.

[0057] As the heat transfer tube 110B moves relative to the second header 180, stress is generated in one or more of the following: the second connecting tube section 113B, the connection between the second connecting tube section 113B and the second header 180, and the connection between the second connecting tube section 113B and the heat exchange section 111B.

[0058] Therefore, one or more of the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B have a stress reduction structure SS that reduces stress. In this embodiment, however not limited, the stress reduction structure SS is arranged at the connection portion between the first header 170 and the heat transfer tube 110A, the connection portion between the heat transfer tube 110A and the heat transfer tube 110B, and the connection portion between the second header 180 and the heat transfer tube 110B. The first connecting pipe section 112A is an example of the connection portion between the first header 170 and the heat transfer tube 110A. The second connecting pipe section 113A and the first connecting pipe section 112B are examples of the connection portions between the heat transfer tube 110A and the heat transfer tube 110B. The second connecting pipe section 113B is an example of the connection portion between the second header 180 and the heat transfer tube 110B.

[0059] Figure 7 is a side view showing an example of a stress reduction structure SS according to an embodiment. In Figure 7, heat transfer tubes 110A and 110B, and headers 170 and 180 that are connected to each other are shown, but the holders 130 and 140 are not shown. In this embodiment, although not limited to this embodiment, as shown in Figure 7, the first connecting tube portion 112A of the heat transfer tube 110A has a length L1 that is greater than or equal to the first connecting distance d1, which is the shortest distance from the connection portion between the first connecting tube portion 112A and the heat exchange section 111A to the connection portion between the first connecting tube portion 112A and the first header 170, as a stress reduction structure SS. In other words, the length L1 of the first connecting tube portion 112A is greater than or equal to the first distance d1A between the heat exchange section 111A and the first header 170. The length L1 of the first connecting tube portion 112A is secured by including a bent portion, a curved portion, or a combination thereof.

[0060] The second connecting pipe section 113B of the heat transfer tube 110B has a stress reduction structure SS and a length L2 that is equal to or greater than the second connecting distance d2, which is the shortest distance from the connection point between the second connecting pipe section 113B and the heat exchange section 111B to the connection point between the second connecting pipe section 113B and the second header 180. In other words, the length L2 of the second connecting pipe section 113B is equal to or greater than the second distance d2A between the heat exchange section 111B and the second header 180. The length L2 of the second connecting pipe section 113B is ensured by including a bent portion, a curved portion, or a combination thereof.

[0061] The combination of the second connecting pipe section 113A of the heat transfer tube 110A and the first connecting pipe section 112B of the heat transfer tube 110B has a stress reduction structure SS with a length L3 that is greater than or equal to the third connecting distance d3, which is the shortest distance from the connection point between the second connecting pipe section 113A and the heat exchange section 111A to the connection point between the first connecting pipe section 112B and the heat exchange section 111B. In other words, the length L3 is greater than or equal to the third distance d3A between the heat exchange section 111A and the heat exchange section 111B. The combination of the second connecting pipe section 113A and the first connecting pipe section 112B ensures the length L3 by including a bent section, a curved section, or a combination thereof, either or both.

[0062] In this embodiment, however not limited thereto, the heat transfer tube 110A has the same diameter as the heat transfer tube 110B and is made of the same material as the heat transfer tube 110B. The heat transfer tubes 110A and 110B have the same Young's modulus and allowable stress.

[0063] The length L1 may be set according to a first condition, where the greater the amount of sliding the first retainer 130 can perform, i.e., the greater the possible displacement S1 of the heat transfer tube 110A, the greater the length L1. For example, the length L1 may be set to be proportional to the square root of the displacement S1. The displacement S1 may be the possible displacement from the reference position set as a reference to the fifth direction D5, the possible displacement from the reference position to the sixth direction D6, or a displacement that includes both of these.

[0064] The length L1 may be set according to a second condition, which is that the larger the radius r1 of the heat transfer tube 110A, the larger the length L1. For example, the length L1 may be set to be proportional to the square root of the radius r1.

[0065] The length L1 may be set according to a third condition, which is that the larger the Young's modulus E1 of the heat transfer tube 110A, the larger the length L1. For example, the length L1 may be set to be proportional to the square root of the Young's modulus E1.

[0066] The length L1 may be set according to the fourth condition, which is that the larger the allowable stress σ1 of the heat transfer tube 110A, the smaller the length L1. For example, the length L1 may be set to be inversely proportional to the square root of the allowable stress σ1.

[0067] Length L1 may be set according to the fifth condition that length L1 is greater than or equal to length LA shown in the following equation 1. The unit of LA is mm. E1 is the Young's modulus of the heat transfer tube 110A, with units of MPa. S1 is the possible displacement of the heat transfer tube 110A, with units of mm. r1 is the radius of the heat transfer tube 110A, with units of mm. σ1 is N / mm2 This is the allowable stress for heat transfer tube 110A.

[0068]

number

[0069] The length L1 may be set according to one of the first to fifth conditions, or according to a combination of two or more of the first to fifth conditions.

[0070] The length L2 may be set according to the sixth condition, which states that the greater the amount of sliding the second retainer 140 can perform, i.e., the greater the possible displacement S2 of the heat transfer tube 110B, the greater the length L2. For example, the length L2 may be set to be proportional to the square root of the displacement S2. The displacement S2 may be the possible displacement from the reference position set as a reference to the fifth direction D5, the possible displacement from the reference position to the sixth direction D6, or a displacement that includes both of these.

[0071] The length L2 may be set according to the seventh condition, which is that the larger the radius r2 of the heat transfer tube 110B, the larger the length L2. For example, the length L2 may be set to be proportional to the square root of the radius r2.

[0072] The length L2 may be set according to the eighth condition, which states that the larger the Young's modulus E2 of the heat transfer tube 110B, the larger the length L2. For example, the length L2 may be set to be proportional to the square root of the Young's modulus E2.

[0073] The length L2 may be set according to the ninth condition, which states that the larger the allowable stress σ2 of the heat transfer tube 110B, the smaller the length L2. For example, the length L2 may be set to be inversely proportional to the square root of the allowable stress σ2.

[0074] Length L2 may be set according to the 10th condition that length L2 is greater than or equal to length LB, which is given by the following equation 2. LB is in units of mm. E2 is the Young's modulus of the heat transfer tube 110B, in units of MPa. S2 is the possible displacement of the heat transfer tube 110B, in units of mm. r2 is the radius of the heat transfer tube 110B, in units of mm. σ2 is in units of N / mm 2 This is the allowable stress for the heat transfer tube 110B.

[0075]

number

[0076] The length L2 may be set according to one of the sixth to tenth conditions, or according to a combination of two or more of the sixth to tenth conditions.

[0077] The length L3 of the combination of the second connecting pipe section 113A of the heat transfer tube 110A and the first connecting pipe section 112B of the heat transfer tube 110B may be set to be larger the larger the slide amount, which includes the slide amount that the first holder 130 of the heat transfer tube 110A can slide and the slide amount that the second holder 140 of the heat transfer tube 110B, which is connected to the heat transfer tube 110A, can slide. In other words, the length L3 may be set according to the 11th condition that the larger the relative displacement amount S3 that the first holder 130 can displace in directions D5 and D6 relative to the second holder 140, the larger the length L3 is.

[0078] The length L3 may be set according to the 12th condition, which states that the larger the radius r of the heat transfer tube 110, the larger the length L3 is, which is one or more of the radii of the second connecting pipe section 113A of the heat transfer tube 110A and the radii of the first connecting pipe section 112B of the heat transfer tube 110B. For example, the length L3 may be set to be proportional to the square root of the radius r.

[0079] The length L3 may be set according to the 13th condition, which states that the larger the Young's modulus E of the heat transfer tube 110, the larger the length L3 is, which is one or more of the Young's modulus E of the heat transfer tube 110A and the Young's modulus E of the first connecting tube 112B of the heat transfer tube 110B. For example, the length L3 may be set to be proportional to the square root of the Young's modulus E.

[0080] The length L3 may be set according to the 14th condition, which states that the larger the allowable stress σ of the heat transfer tube 110, the smaller the length L3 should be, which is one or more of the allowable stress of the second connecting pipe section 113B of the heat transfer tube 110A and the allowable stress of the first connecting pipe section 112B of the heat transfer tube 110B. For example, the length L3 may be set to be inversely proportional to the square root of the allowable stress σ.

[0081] Length L3 may be set according to condition 15, which states that length L3 is greater than or equal to length LC shown in equation 3 below. LC is in units of mm. E3 is the Young's modulus of the heat transfer tube 110, in units of MPa. S3 is the possible relative displacement between heat transfer tubes 110A and 110B, in units of mm. r3 is the radius of the heat transfer tube 110, in units of mm. σ3 is in units of N / mm 2 This is the allowable stress of the heat transfer tube 110. E3, r3, and σ3 may be the same as E1, r1, and σ1 of heat transfer tube 100A, or the same as E2, r2, and σ2 of heat transfer tube 100B, or they may be calculated values ​​of E1 and E2, r1 and r2, and σ1 and σ2. Examples of calculated values ​​may include average values ​​such as arithmetic mean, harmonic mean, square mean, and weighted mean. For example, in the weighted mean, weighting based on the ratio of the second connecting pipe section 113A and the first connecting pipe section 112B in length L3 may be used.

[0082]

number

[0083] The length L3 may be set according to one of the 11th to 15th conditions, or according to a combination of two or more of the 11th to 15th conditions.

[0084] In the heat exchanger 100 described above, both the pair of heat transfer tubes 110A held by the first holder 130 and the pair of heat transfer tubes 110B held by the second holder 140 are displaceable in directions D5 and D6. This allows the gaps between the pairs of heat transfer tubes 110A and the pairs of heat transfer tubes 110B to be enlarged, allowing an operator to enter the gaps and remove dust adhering to the heat transfer tubes 110A and 110B. Since the heat transfer tubes 110A and 110B are finned tubes, dust may remain at the base of the fins even after being struck by a hammering device, but this dust can be removed.

[0085] Since lengths L1, L2, and L3 are set as described above, when the heat transfer tubes 110A and 110B move, one or more of the first connecting pipe sections 112A, 113A, 112B, and 113B can bend. As a result, stress is absorbed in one or more of the first connecting pipe sections 112A, 113A, 112B, and 113B, preventing damage to the heat transfer tubes 110A and 110B and the headers 170 and 180.

[0086] [Other embodiments] While exemplary embodiments of the present disclosure have been described above, the disclosure is not limited to the embodiments described above. That is, various modifications and improvements are possible within the scope of the disclosure. For example, embodiments that have been modified in various ways, and forms constructed by combining components from different embodiments, are also included within the scope of the disclosure.

[0087] For example, in this embodiment, the plurality of heat transfer tubes 110 includes, but is not limited to, two groups of heat transfer tubes, a first heat transfer tube group G1 and a second heat transfer tube group G2, which are connected to each other. For example, the plurality of heat transfer tubes 110 may include only one heat transfer tube group, or it may include three or more heat transfer tube groups that are connected to each other.

[0088] In this embodiment, the first heat transfer tube group G1 and the second heat transfer tube group G2 are arranged side by side in the vertical direction along the third direction D3, but are not limited to this. For example, the first heat transfer tube group G1 and the second heat transfer tube group G2 may be arranged side by side in a direction intersecting the third direction. If the multiple heat transfer tubes 110 include three or more heat transfer tube groups, the three or more heat transfer tube groups may include heat transfer tube groups arranged side by side in the third direction D3, heat transfer tube groups arranged side by side in a direction intersecting the third direction, or a combination thereof.

[0089] In the embodiment, the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B have, as stress reduction structures SS, a structure that increases the length of the first connecting pipe section 112A, a structure that increases the length of the second connecting pipe section 113B, and a structure that increases the length of the combination of the second connecting pipe section 113A and the first connecting pipe section 112B, but are not limited thereto. For example, as shown in Figure 8, the first connecting pipe section 112A, the second connecting pipe section 113B, and the combination of the second connecting pipe section 113A and the first connecting pipe section 112B may include a flexible portion, an expandable portion, or a combination thereof as a stress reduction structure SS. The first connecting pipe section 112A, the second connecting pipe section 113B, and the combination of the second connecting pipe section 113A and the first connecting pipe section 112B may include a structure that increases the length, a flexible structure, an expandable structure, or a combination of two or more thereof. Figure 8 is a side view showing a modified example of the stress-reducing structure SS, similar to Figure 7.

[0090] For example, a flexible pipe or flexible pipe fitting may be used as the flexible portion. At least a portion of the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B may be made of a material that is more elastic or flexible than the heat transfer pipes 110A and 110B, and such a portion may function as the flexible portion. For example, an expansion pipe or expansion pipe fitting may be used as the expansion portion. At least a portion of the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B may be made of a material that is more expandable than the heat transfer pipes 110A and 110B, and such a portion may function as the expansion portion. The flexible and expandable portions may be located in the straight pipe portion 111a or curved pipe portion 111b of the heat exchange sections 111A and 111B adjacent to the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B.

[0091] In this embodiment, the stress reduction structure SS is positioned in the first connecting pipe section 112A and the second connecting pipe section 113A of the heat transfer tube 110A, and in the first connecting pipe section 112B and the second connecting pipe section 113B of the heat transfer tube 110B. In other words, the stress reduction structure SS is positioned in the heat transfer tubes 110A and 110B. The position of the stress reduction structure SS is not limited to the heat transfer tubes 110A and 110B. For example, the first connecting pipe section 112A and the second connecting pipe section 113A may be made of a different material than the heat transfer tube 110A, or may be made as separate components from the heat transfer tube 110A, and the stress reduction structure SS may be positioned in such first connecting pipe section 112A and second connecting pipe section 113A. The first connecting pipe section 112B and the second connecting pipe section 113B may be made of a different material from the heat transfer tube 110B, or may be made as separate components from the heat transfer tube 110B, and a stress reduction structure SS may be placed in such the first connecting pipe section 112B and the second connecting pipe section 113B. The stress reduction structure SS described above may be placed in the straight pipe section 111a or the curved pipe section 111b of the heat exchange sections 111A and 111B adjacent to the first connecting pipe section 112A, the second connecting pipe section 113A, the first connecting pipe section 112B, and the second connecting pipe section 113B.

[0092] In this embodiment, the stress reduction structure SS is arranged in three parts: the first connecting pipe section 112A of the heat transfer tube 110A, the combination of the second connecting pipe section 113A of the heat transfer tube 110A and the first connecting pipe section 112B of the heat transfer tube 110B, and the second connecting pipe section 113B of the heat transfer tube 110B, but is not limited to this. The stress reduction structure SS may be arranged in one or more of the above three parts. When the heat transfer tubes 110A, 110B, or both slide due to the holders 130 and 140, one of the heat transfer tubes 110A and 110B moves in accordance with the other, thereby the stress reduction structure SS can reduce the stress generated in the heat transfer tubes 110A and 110B.

[0093] In this embodiment, the holders 130 and 140 have a structure for holding two heat transfer tubes 110, but are not limited to this. The holders 130 and 140 may have a structure for holding one heat transfer tube 110, or they may have a structure for holding three or more heat transfer tubes 110.

[0094] In this embodiment, all of the multiple holders 130 are slidably supported by the guide 150, but are not limited to this. Some of the multiple holders 130 may be fixed so as not to slide. All of the multiple holders 140 are slidably supported by the guide 160, but are not limited to this. Some of the multiple holders 140 may be fixed so as not to slide.

[0095] In this embodiment, the heat exchange section 111 of the heat transfer tube 110 has a meandering tube structure, but is not limited thereto. The heat exchange section 111 should have a structure that can increase the contact area with the exhaust gas flowing in the third direction D3. For example, the heat exchange section 111 may have a spiral tube structure, a branched tube structure that branches into multiple tubes, an expanding diameter structure, or a combination of two or more of these. In a heat exchange section 111 having a meandering tube structure, the direction in which the straight tube portion 111a extends is not limited to the first direction D1. For example, the direction in which the straight tube portion 111a extends may be a direction along the flow direction of the exhaust gas, such as the third direction D3, or it may be a fifth direction D5, or it may be a direction that diagonally intersects one or more of the first direction D1, the third direction D3, and the fifth direction D5.

[0096] Examples of each aspect of the technology of this disclosure are given below. A heat exchanger according to the first aspect of this disclosure includes a group of heat transfer tubes through which a heat exchange medium flows, a group of holders that hold one or more of the heat transfer tubes, a guide that movably supports at least a portion of the group of holders, a header that is connected to and fixedly positioned in communication with the group of heat transfer tubes, and a stress reduction structure that is positioned at the connection point between the header and the heat transfer tubes and reduces the stress generated in the heat transfer tubes when the holders move.

[0097] According to the above embodiment, the heat transfer tubes held by the holder can be moved by the movement of the holder. Therefore, the gap between the heat transfer tubes can be changed. By widening the gap between the heat transfer tubes, an operator can enter the gap and perform maintenance such as cleaning the heat transfer tubes. Furthermore, since the heat exchanger includes a stress reduction structure at the connection point between the header and the heat transfer tubes, the stress generated in the moved heat transfer tubes relative to the fixed header can be reduced, preventing damage to the heat transfer tubes, etc. Thus, the safe maintainability of the heat transfer tubes is improved.

[0098] In the heat exchanger according to the second aspect of the present disclosure in the first aspect described above, the direction in which the holder can move may be in the direction in which the plurality of heat transfer tubes are adjacent to each other.

[0099] According to the above embodiment, the heat transfer tubes held by the holder can be moved in such a way that the gap between them and adjacent heat transfer tubes is changed by the movement of the holder. Since the gap between adjacent heat transfer tubes can be changed, maintenance of the heat transfer tubes becomes easier.

[0100] In the heat exchanger according to the third aspect of the present disclosure in the first or second aspect described above, the holder may hold the one or more heat transfer tubes in a manner that suspends them.

[0101] According to the above embodiment, the force required to move the holder that suspends the heat transfer tube can be reduced. Since the holder and the heat transfer tube can be moved more easily, maintenance of the heat transfer tube becomes easier.

[0102] In a heat exchanger according to a fourth aspect of the present disclosure in any of the first to third aspects described above, the heat transfer tube includes a first tube portion having a structure that increases the contact area with the heat exchange object flowing through the heat exchanger, and a second tube portion connecting the header and the first tube portion, and the stress reduction structure may be arranged in the second tube portion as the connecting portion.

[0103] According to the above embodiment, when the heat transfer tube moves, the stress reduction structure reduces the stress generated in the second tube section and prevents the stress from extending to the first tube section. As a result, the heat exchange capacity of the first tube section is not affected by the stress. Therefore, the heat exchanger can maintain its heat exchange capacity while preventing damage to the heat transfer tubes due to their movement.

[0104] In the heat exchanger according to the fifth aspect of the present disclosure in the fourth aspect described above, the heat transfer tube may include at least a plurality of fins arranged around the heat transfer tube in the first tube portion.

[0105] According to the above embodiment, the heat exchanger can increase the heat exchange area and improve the heat exchange capacity, at least in the first tube section. For example, if the heat transfer tube has a meandering shape in the first tube section, the heat transfer tube can increase its heat exchange area with multiple fins, thus reducing the number of meanders in the heat transfer tube. Therefore, the heat transfer tube and the group of heat transfer tubes can be made more compact.

[0106] In the heat exchanger according to the sixth aspect of the present disclosure as described in the fourth or fifth aspect above, the stress reduction structure may include a first structure which is the structure of the second pipe portion in which the length of the second pipe portion is equal to or greater than a first distance between the first pipe portion and the header.

[0107] According to the above embodiment, stress reduction by the second pipe section is possible with a simple first structure in which the length of the second pipe section is equal to or greater than the first distance. The second pipe section can bend when the heat transfer tube moves, and can absorb stress by bending. The first structure may be realized by including a bent portion in the second pipe section, including a bent shape, a curved shape, or a combination thereof.

[0108] In the heat exchanger according to the seventh aspect of the present disclosure in the sixth aspect described above, the length of the second tube portion in the first structure may be set according to one or more of the following conditions: a first condition that the greater the amount of displacement that the holder can move, the greater the length of the second tube portion; a second condition that the greater the diameter of the heat transfer tube, the greater the length of the second tube portion; a third condition that the greater the Young's modulus of the heat transfer tube, the greater the length of the second tube portion; and a fourth condition that the greater the allowable stress of the heat transfer tube, the smaller the length of the second tube portion.

[0109] According to the above embodiment, the criteria for setting the length of the second pipe section, which is greater than or equal to the first distance, become clear. Therefore, setting the length of the second pipe section becomes easier.

[0110] In the heat exchanger according to the eighth aspect of the present disclosure in the seventh aspect described above, under the first condition, the length of the second tube portion is proportional to the square root of the amount of displacement the holder can move; under the second condition, the length of the second tube portion is proportional to the square root of the radius of the heat transfer tube; under the third condition, the length of the second tube portion is proportional to the square root of the Young's modulus of the heat transfer tube; and under the fourth condition, the length of the second tube portion is inversely proportional to the square root of the allowable stress of the heat transfer tube.

[0111] According to the above embodiment, the criteria for setting the length of the second pipe section, which is greater than or equal to the first distance, become clearer. Therefore, setting the length of the second pipe section becomes even simpler.

[0112] In the heat exchanger according to the ninth aspect of the present disclosure, as described in any of the sixth to eighth aspects above, the length of the second tube portion in the first structure may be greater than or equal to a length L set by the following formula based on the amount of displacement S that the holder can move, the radius r of the heat transfer tube, the Young's modulus E of the heat transfer tube, and the allowable stress σ of the heat transfer tube.

[0113]

number

[0114] According to the above embodiment, the criteria for setting the length of the second pipe section, which is greater than or equal to the first distance, become more specific. Therefore, setting the length of the second pipe section becomes even simpler.

[0115] In the heat exchanger according to the tenth aspect of the present disclosure as described in any of the first to ninth aspects above, the stress reduction structure may include a second structure in which a flexible tube, an expansion joint, or a combination thereof is included in the connection portion.

[0116] According to the above embodiment, the flexible tube, expansion joint, and combination thereof absorb the stress that may occur in the heat transfer tube by deforming. Therefore, the stress that may occur in the heat transfer tube is effectively reduced. The heat exchanger may include the first structure, the second structure, or both thereof, enabling effective stress reduction.

[0117] In the heat exchanger according to the 11th aspect of the present disclosure in any of the first to tenth aspects described above, the heat transfer tube group includes a first heat transfer tube group and a second heat transfer tube group arranged apart from each other, wherein a plurality of the heat transfer tubes of the first heat transfer tube group are connected to a first header as the header on the upstream side in the flow direction of the heat exchange medium, and are connected to a plurality of the heat transfer tubes of the second heat transfer tube group on the downstream side in the flow direction of the heat exchange medium, wherein a plurality of the heat transfer tubes of the second heat transfer tube group are connected to a second header which is fixedly arranged on the downstream side in the flow direction of the heat exchange medium, and the stress reduction structure may be arranged in one or more of the connection portion between the first header and the first heat transfer tube group, the connection portion between the first heat transfer tube group and the second heat transfer tube group, and the connection portion between the second heat transfer tube group and the second header.

[0118] According to the above embodiment, when the heat transfer tubes of the first heat transfer tube group are moved via the holder, when the second heat transfer tube group is moved via the holder, or in both cases, the stress reduction structure can reduce the stress generated in the heat transfer tubes of the first heat transfer tube group and the heat transfer tubes of the second heat transfer tube group.

[0119] In the heat exchanger according to the twelfth aspect of the present disclosure in the eleventh aspect described above, the plurality of heat transfer tubes of the first heat transfer tube group include a first tube portion having a structure that increases the contact area with the heat exchange object flowing through the heat exchanger, a second tube portion connecting the first header and the first tube portion, and a third tube portion connecting the second heat transfer tube group and the first tube portion; the plurality of heat transfer tubes of the second heat transfer tube group include a fourth tube portion having a structure that increases the contact area with the heat exchange object flowing through the heat exchanger, and a fifth tube portion connecting the second header and the fourth tube portion; and the stress reduction structure may be arranged in one or more of the second tube portion, the third tube portion and the fifth tube portion.

[0120] According to the above embodiment, when the heat transfer tubes of the first heat transfer tube group move relative to the first header, the stress reduction structure can reduce the stress generated in the second tube section and suppress the stress from extending to the first tube section. When the heat transfer tubes of the second heat transfer tube group move relative to the second header, the stress reduction structure can reduce the stress generated in the fifth tube section and suppress the stress from extending to the fourth tube section. When the heat transfer tubes of the first heat transfer tube group and the heat transfer tubes of the second heat transfer tube group move relative to each other, the stress reduction structure can reduce the stress generated in the third tube section and suppress the stress from extending to the second and fourth tube sections. Therefore, effective stress reduction is possible.

[0121] All ordinal numbers, quantities, and other figures used herein are illustrative to illustrate the technology of this disclosure, and this disclosure is not limited to such illustrative figures. The connections between components are illustrative to illustrate the technology of this disclosure, and the connections that realize the functions of this disclosure are not limited to these.

[0122] This disclosure can be implemented in various ways without departing from the scope of its essential features, and the scope of this disclosure is defined more by the appended claims than by the description in the specification; therefore, exemplary embodiments and modifications are illustrative and not limiting. All modifications within the claims and their scope, or equivalents within the claims and their scope, are intended to be encompassed by the claims. [Explanation of Symbols]

[0123] 100 heat exchanger 110, 110A, 110B heat exchanger tube 110b Fin section 111, 111A, 111B Heat exchange section (1st pipe section, 4th pipe section) 112, 112A, 112B 1st connection pipe part (2nd pipe part, 3rd pipe part) 113, 113A, 113B 2nd connecting pipe part (3rd pipe part, 5th pipe part) 130, 140 Holder Guides 150 and 160 170, 180 headers G1 First heat transfer tube group G2 Second heat transfer tube group SS stress reduction structure

Claims

1. A group of heat transfer tubes including multiple heat transfer tubes through which a heat exchange medium flows, A plurality of holders that hold one or more of the heat transfer tubes, A guide that movably supports at least a portion of the plurality of holders, A header is connected to the aforementioned plurality of heat transfer tubes and is fixedly positioned, It includes a stress reduction structure disposed at the connection point between the header and the heat transfer tube, which reduces the stress generated in the heat transfer tube when the holder moves. heat exchanger.

2. The direction in which the holder can move is the direction in which the plurality of heat transfer tubes are adjacent to each other. The heat exchanger according to claim 1.

3. The holder holds one or more heat transfer tubes in a suspended manner. The heat exchanger according to claim 1.

4. The heat transfer tube includes a first tube portion having a structure that increases the contact area with the heat exchange object flowing through the heat exchanger, and a second tube portion connecting the header and the first tube portion. The stress reduction structure is arranged in the second pipe portion as the connecting portion. The heat exchanger according to claim 1.

5. The heat transfer tube includes at least a plurality of fins arranged around the heat transfer tube in the first tube portion. The heat exchanger according to claim 4.

6. The stress reduction structure includes a first structure in which the length of the second pipe portion is equal to or greater than a first distance between the first pipe portion and the header. The heat exchanger according to claim 4.

7. The length of the second pipe portion in the first structure is The first condition is that the greater the amount of displacement the holder can move, the greater the length of the second pipe portion. The second condition is that the larger the diameter of the heat transfer tube, the longer the length of the second tube portion. The third condition is that the larger the Young's modulus of the heat transfer tube, the longer the second tube portion. The length is set according to one or more of the following conditions: the greater the allowable stress of the heat transfer tube, the smaller the length of the second tube section, and the fourth condition. The heat exchanger according to claim 6.

8. In the first condition, the length of the second pipe portion is proportional to the square root of the amount of displacement the holder can move. In the second condition described above, the length of the second tube portion is proportional to the square root of the radius of the heat transfer tube, In the third condition described above, the length of the second tube portion is proportional to the square root of the Young's modulus of the heat transfer tube. In the fourth condition described above, the length of the second pipe section is inversely proportional to the square root of the allowable stress of the heat transfer tube. The heat exchanger according to claim 7.

9. The length of the second pipe portion in the first structure is The length L is greater than or equal to the amount of displacement S that the holder can move, the radius r of the heat transfer tube, the Young's modulus E of the heat transfer tube, and the allowable stress σ of the heat transfer tube, as determined by the following formula. [Math 1] The heat exchanger according to claim 6.

10. The stress reduction structure includes a second structure which includes a flexible tube, an expansion joint, or a combination thereof in the connecting portion. The heat exchanger according to claim 1.

11. The heat transfer tube group includes a first heat transfer tube group and a second heat transfer tube group arranged apart from each other, The plurality of heat transfer tubes of the first heat transfer tube group are connected to the first header, which acts as a header, on the upstream side in the flow direction of the heat exchange medium, and are connected to the plurality of heat transfer tubes of the second heat transfer tube group on the downstream side in the flow direction of the heat exchange medium. The plurality of heat transfer tubes of the second heat transfer tube group are connected to a second header that is fixedly positioned downstream in the flow direction of the heat exchange medium, and communicate with it. The stress reduction structure is provided at one or more of the following locations: the connection between the first header and the first heat transfer tube group, the connection between the first heat transfer tube group and the second heat transfer tube group, and the connection between the second heat transfer tube group and the second header. A heat exchanger according to any one of claims 1 to 10.

12. The plurality of heat transfer tubes of the first heat transfer tube group include a first tube portion having a structure that increases the contact area with the heat exchange target flowing through the heat exchanger, a second tube portion connecting the first header and the first tube portion, and a third tube portion connecting the second heat transfer tube group and the first tube portion. The plurality of heat transfer tubes in the second heat transfer tube group include a fourth tube portion having a structure that increases the contact area with the heat exchange object flowing through the heat exchanger, and a fifth tube portion connecting the second header and the fourth tube portion. The stress reduction structure is arranged in one or more of the second pipe section, the third pipe section, and the fifth pipe section. The heat exchanger according to claim 11.

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