JP2018009762A - Heat exchanger and boiler - Google Patents

Abstract

[Problem] To provide a heat exchanger, such as a reheater or superheater, installed in a boiler, that can have a header pipe with a smaller diameter than conventional heat exchangers while maintaining steam flow characteristics (pressure loss, flow rate, etc.) equivalent to those of conventional heat exchangers. [Solution] A heat exchanger comprising a plurality of heat transfer tubes arranged in a predetermined direction through which a fluid flows, an inlet header pipe extending in the arrangement direction of the plurality of heat transfer tubes and connected to the inlet ends of the heat transfer tubes, and an outlet header pipe extending in the arrangement direction of the plurality of heat transfer tubes and connected to the outlet ends of the heat transfer tubes, wherein the plurality of heat transfer tubes are exposed to a fluid to be heat exchanged, the plurality of heat transfer tubes being organized into two or more groups, and two or more inlet header pipes and/or outlet header pipes being provided for each group. [Selected Drawing] Figure 1

Description

  The present invention relates to a heat exchanger and a boiler.

  For example, Patent Document 1 discloses a final superheater (heat exchanger) in which a plurality of heat transfer tubes provided between an inlet header and an outlet header constitute a plate-type heat transfer unit. In the final superheater according to Patent Document 1, a plurality of plate heat transfer units are connected to one inlet header and one outlet header. In this final superheater, the plate-like heat transfer section is disposed inside the furnace, and the fluid flowing through the heat transfer tube is heated by the combustion gas of the furnace.

Japanese Patent Laid-Open No. 11-22914

  By the way, in recent years, the temperature of the fluid flowing through the reheater and the superheater has been increased in order to improve the efficiency of the turbine. For this reason, in the outlet header pipe or the inlet header pipe, it is required to employ a material having higher heat resistance than the conventional pipe material. Such a material having high heat resistance is industrially difficult to process into a pipe diameter equivalent to that of a conventional header pipe, and it may be necessary to reduce the pipe diameter.

  The present invention has been made in view of the above-described problems. In a heat exchanger such as a reheater or a superheater installed in a boiler, the characteristics of the fluid (pressure loss and flow rate) equivalent to those of a conventional heat exchanger are provided. Etc.) and the diameter of the header pipe can be made smaller than that of a conventional heat exchanger.

  The present invention adopts the following configuration as means for solving the above-described problems.

  1st invention which concerns on a heat exchanger is extended along the sequence direction of the some heat exchanger tube which the fluid distribute | circulates and arrange | positions in a predetermined direction, and is connected to the inlet end of the said heat exchanger tube An inlet header pipe, and an outlet header pipe extending along an arrangement direction of the plurality of heat transfer tubes and connected to an outlet end of the heat transfer tubes, wherein the plurality of heat transfer tubes serve as heat exchange target fluids. The heat exchanger to be exposed, wherein the plurality of heat transfer tubes constitutes two or more groups, and two or more inlet header tubes and / or outlet header tubes are provided for each group. Adopt the configuration.

  In a second aspect of the heat exchanger according to the first aspect, two or more of the inlet header pipes and / or the outlet header pipes provided for each group have the same pipe length and are arranged with both ends aligned. Adopted a configuration that is.

  In a third aspect of the heat exchanger according to the first or second aspect of the present invention, the group is set so that the temperature of the fluid in the outlet header pipe provided in each group is two or more. Adopt the configuration that.

  In a fourth aspect of the heat exchanger according to any one of the first to third aspects, the group is set such that the heat transfer tubes adjacent to each other in the arrangement direction belong to different groups. adopt.

  1st invention which concerns on a boiler employ | adopts the structure provided with the heat exchanger which concerns on any one of the said 1st-4th invention.

  2nd invention which concerns on a boiler is the said 1st invention. WHEREIN: Two heat exchangers connected in series are provided, The said heat exchanger connected to a back | latter stage is any one of Claims 1-4. The configuration of the heat exchanger described in the above is adopted.

  According to the present invention, the heat exchanger has a plurality of at least one of an inlet header pipe and an outlet header pipe. Thereby, the flow volume of the vapor | steam which flows in into one header pipe | tube can be reduced rather than before. Therefore, the diameter of the header pipe can be reduced while ensuring the same steam flow characteristics as those of the conventional heat exchanger in the entire heat exchanger.

It is a schematic diagram which shows the apparatus structure of the superheater which concerns on one Embodiment of this invention. It is a figure which shows the heat exchanger panel of the superheater which concerns on one Embodiment of this invention, (a) is a schematic diagram of the heat exchanger panel which belongs to an odd number row group, (b) of the heat exchanger panel which belongs to an even number row group It is a schematic diagram. It is an apparatus block diagram of the boiler apparatus in one Embodiment of this invention. It is a block diagram of the reheat system 150 in this embodiment.

  Hereinafter, an embodiment of a heat exchanger according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

[First Embodiment]
First, the reheater 1 is demonstrated as 1st Embodiment of this invention.
FIG. 1 is a schematic diagram showing an apparatus configuration of a reheater 1 according to the first embodiment of the present invention. As shown in FIG. 1, the reheater 1 is a once-through heat exchanger including an inlet header pipe 2, a heat transfer unit 3, and an outlet header unit 4. The inlet header pipe 2 is a tubular member, and steam is supplied from both ends. The inlet header pipe 2 is a straight tubular member connected to a pipe (not shown) at both ends and connected to a heat transfer panel 3A (described later) of the heat transfer section 3 on the peripheral surface. In the inlet header pipe 2, the steam supplied from both ends merges in the pipe and then is supplied toward the heat transfer section 3.

  As shown in FIG. 1, the heat transfer section 3 has a configuration in which a plurality of heat transfer panels 3 </ b> A connected vertically to the inlet header pipe 2 are arranged in parallel. The heat transfer panel 3A is formed by arranging a plurality of heat transfer tubes bent a plurality of times in a plate shape. Note that only four heat transfer panels 3A in FIG. 1 are schematically illustrated, but may be five or more. Further, in the heat transfer section 3, the heat transfer panels 3A provided on the odd-numbered (first, third,..., N-th) from the left in FIG. The heat transfer panels 3A provided in (second, fourth,..., N + 1) constitute the even-numbered column group 3b. That is, the heat transfer panels 3A adjacent to each other are set to belong to different groups.

FIG. 2 is a view showing the heat transfer panel 3A of the reheater 1 according to the present embodiment, where (a) is a schematic view of the heat transfer panel 3A belonging to the odd-numbered row group 3a, and (b) is the even-numbered row group. It is a schematic diagram of the heat-transfer panel 3A which belongs to 3b. In FIG. 2, only one of the heat transfer tubes constituting the heat transfer panel 3A is shown.
As shown in FIGS. 1 and 2, the heat transfer panel 3 </ b> A belonging to the odd-numbered row group 3 a is connected to the inlet header pipe 2 and to a first header pipe 4 a described later of the outlet header section 4. As shown in FIG. 2A, the heat transfer tubes of the heat transfer panel 3A belonging to the odd-numbered row group 3a are bent along the peripheral surfaces of the inlet header tube 2 and the first header tube 4a at both ends of the heat transfer tubes. The central portion excluding both ends is bent a plurality of times in the vertical direction in FIG. The heat transfer panel 3A belonging to the odd-numbered row group 3a is a heating unit 3a1 in which the central portion of the heat transfer tube bent a plurality of times is exposed to the boiler body. The heating unit 3a1 is a region heated by high-temperature combustion gas (heat exchange target fluid) in the boiler body.

  As shown in FIGS. 1 and 2, the heat transfer panel 3 </ b> A belonging to the even-numbered column group 3 b is connected to the inlet header pipe 2 and to a second header pipe 4 b described later of the outlet header section 4. As shown in FIG. 2B, the heat transfer tube of the heat transfer panel 3A belonging to the even row group 3b has one end of the heat transfer tube curved along the peripheral surface of the inlet header tube 2, and the other Are bent toward the second header pipe 4b of the outlet header section 4 and are curved along the peripheral surface of the second header pipe 4b. Further, the central portion excluding both ends of the heat transfer tubes of the heat transfer panel 3A belonging to the even row group 3b has the same shape as the heat transfer panel 3A belonging to the odd row group 3a, and in the vertical direction in FIG. It is bent several times. The central portion of the heat transfer tube of the heat transfer panel 3A belonging to the even row group 3b is similar to the heat transfer panel 3A belonging to the odd row group 3a. It has become. The heating unit 3b1 is a region heated by high-temperature air in the furnace. That is, the heating unit 3a1 and the heating unit 3b1 are set to have the same surface area.

  The outlet header section 4 has a first header pipe 4a (outlet header pipe) and a second header pipe 4b (outlet header pipe). The 1st header pipe | tube 4a and the 2nd header pipe | tube 4b are the same pipe | tube length, are parallel to the inlet header pipe | tube 2, respectively, and are the straight tubular members arrange | positioned by aligning both ends. The first header pipe 4a and the second header pipe 4b extend along the arrangement direction of the heat transfer panel 3A. Further, the first header pipe 4 a and the second header pipe 4 b are set to have a smaller pipe diameter than the inlet header pipe 2. Both ends of the first header pipe 4a and the second header pipe 4b are connected to piping or the like, and steam (fluid) is supplied from both ends to an external device such as a turbine. That is, the first header pipe 4a and the second header pipe 4b are connected in parallel.

  The first header pipe 4a is a pipe member arranged at a position closer to the inlet header pipe 2 than the second header pipe 4b. The first header pipe 4a is connected to the heat transfer panel 3A belonging to the odd row group 3a, and supplies the steam flowing in from the heat transfer panel 3A belonging to the odd row group 3a to the external device. The second header pipe 4b is connected to the heat transfer panel 3A belonging to the even-numbered row group 3b, and supplies the steam flowing in from the heat transfer panel 3A belonging to the even-numbered row group 3b to the external device. That is, the heat transfer panel 3A belonging to the adjacent odd-numbered row group 3a and the heat transfer panel 3A belonging to the even-numbered row group 3b are connected to different header pipes of the outlet header portion 4.

The operation of the reheater 1 according to this embodiment will be described.
The steam flowing in from both ends of the inlet header pipe 2 flows into the heat transfer panel 3A belonging to the odd row group 3a and the heat transfer panel 3A belonging to the even row group 3b. The combustion gas in the boiler body flows between the heat transfer panel 3A and the heat transfer panel 3A in a direction parallel to the heat transfer panel 3A. The steam flowing into the heat transfer panel 3A belonging to the odd row group 3a and the heat transfer panel 3A belonging to the even row group 3b is heated by being exposed to the combustion gas in the boiler body while moving inside the heat transfer tube. And flows into the outlet header portion 4 in a high temperature state. At this time, since the surface areas of the heating section 3a1 of the heat transfer panel 3A belonging to the odd-numbered row group 3a and the heating section 3b1 of the heat transfer panel 3A belonging to the even-numbered row group 3b are equal, the heating amount is equal and belongs to the odd-numbered row group 3a. A steam temperature difference between the heat transfer panel 3A and the heat transfer panel 3A belonging to the even-numbered row group 3b does not occur.

  Further, since the flow rate distribution exists in the combustion gas flowing in the boiler, the flow rate of the combustion gas flowing around the heat transfer unit is different in the heat transfer panel 3A depending on the arrangement in the boiler. For this reason, the amount of heating of the internal steam differs for each heat transfer panel 3A, and the steam temperature may vary downstream of the heat transfer panel 3A. On the other hand, since the heat transfer panel 3A of the heat transfer section 3 is alternately connected to the first header pipe 4a and the second header pipe 4b, the high temperature steam and the low temperature steam are mixed, and the first The steam temperatures in the header pipe 4a and the second header pipe 4b are made uniform and equal.

  The steam that has flowed into the first header pipe 4a and the second header pipe 4b moves inside the first header pipe 4a and the second header pipe 4b, and flows into the external device from both ends. In addition, each flow volume of the vapor | steam which flows in into the 1st header pipe | tube 4a and the 2nd header pipe | tube 4b turns into a vapor | steam flow volume of about half of the inlet header pipe | tube 2.

  According to the reheater 1 according to the present embodiment, the outlet header section 4 includes the first header pipe 4a and the second header pipe 4b, so that the steam heated in the heat transfer section 3 can be The header pipe 4a and the second header pipe 4b can be equally distributed. Thereby, the flow volume of the vapor | steam which distribute | circulates to each of the 1st header pipe | tube 4a and the 2nd header pipe | tube 4b can be suppressed. Therefore, the diameter of the first header pipe 4a and the second header pipe 4b can be reduced in the heat exchanger having the same flow rate as that of the conventional heat exchanger.

  Moreover, even if the diameters of the first header pipe 4a and the second header pipe 4b are reduced, the first header pipe 4a and the second header pipe 4b are compared with the case where the outlet header section 4 is a single pipe. It becomes possible to make each steam flow velocity equivalent, and it becomes possible to make the characteristic of a steam flow equivalent. Furthermore, by suppressing the flow rate of the steam flowing through the first header pipe 4a and the second header pipe 4b, the thickness of the pipe can be made thinner than before.

  Further, the steam temperature on the downstream side of the heat transfer panel 3A may differ depending on the position of the heat transfer panel 3A in the boiler. On the other hand, according to the reheater 1 according to the present embodiment, the odd-numbered column group 3a is connected to the first header tube 4a, and the even-numbered column group 3b is connected to the second header tube 4b. Thereby, the steam in the heat transfer panel 3A is mixed in the first header pipe 4a and the second header pipe 4b. Therefore, the temperature difference between the steam flowing through the first header pipe 4a and the second header pipe 4b is small.

  Further, according to the reheater 1 according to the present embodiment, since the surface areas of the heating unit 3a1 of the odd-numbered column group 3a and the heating unit 3b1 of the even-numbered column group 3b are set to be equal, The heating amount of steam in the group 3a and the even-numbered row group 3b becomes equal. Therefore, there is no temperature difference between the steam flowing through the odd-numbered row group 3a and the steam flowing through the even-numbered row group 3b.

[Second Embodiment]
Subsequently, a boiler apparatus 100 to which the reheater 1 according to the first embodiment is applied will be described as a second embodiment.
FIG. 3 is an apparatus configuration diagram of the boiler apparatus in the present embodiment. As shown in this figure, as shown in FIG. 3, the boiler apparatus 100 includes a boiler body 110, an overheating system 120, a high pressure turbine 130, a medium / low pressure turbine 140, and a reheating system 150 (heat exchange system). It has.

  The boiler body 110 is a container in which fuel is burned, and a flame is formed inside by a burner (not shown) or the like. The superheating system 120 is configured by a superheater or the like disposed in the boiler main body 110, and superheats the steam circulating in the boiler main body 110 to a temperature necessary for driving the high-pressure turbine 130. The high-pressure turbine 130 is a turbine rotated by high-pressure steam heated in the superheat system 120, and is connected to a power generation device (not shown). The steam that has rotated in the high-pressure turbine 130 is supplied to the reheat system 150. The medium / low pressure turbine 140 is a turbine that is rotated by reheat steam supplied from the reheat system 150, and is connected to a power generator (not shown).

  FIG. 4 is a configuration diagram of the reheating system 150 in the present embodiment. In the following description, it is assumed that the upper side in FIG. 4 is right and the lower side is left. As shown in FIG. 4, the reheat system 150 includes a primary reheater 20 and a secondary reheater 30. Moreover, the reheat system has piping P1-7 through which steam flows. Among these, the pipe P <b> 1 is connected to the high-pressure turbine 130. A pipe P2 and a pipe P3 are branched from the pipe P1.

  The primary reheater 20 includes an inlet header pipe 20a, a heat transfer section 20b, and an outlet header pipe 20c. The inlet header pipe 20a is connected to the pipes P2 and P3 branched from the pipe P1 and the heat transfer section 20b, and distributes the steam connected to the high-pressure turbine 130 to the heat transfer section 20b. The heat transfer unit 20b has a plurality of heat transfer panels, is disposed inside the boiler body 110, and heats internal steam by heat exchange with the high-temperature combustion gas in the boiler body 110. The outlet header pipe 20c is connected to the heat transfer section 20b, the pipe P4, and the pipe P5. The steam heated in the heat transfer section 20b is merged in the outlet header pipe 20c and distributed again to the pipe P4 and the pipe P5. The pipe P4 is connected to the right side of the outlet header pipe 20c and connected to the left side of the inlet header pipe 30a. The pipe P5 is connected to the left side of the outlet header pipe 20c and connected to the right side of the inlet header pipe 30a. That is, the pipe P4 and the pipe P5 intersect in the left-right direction.

  The secondary reheater 30 corresponds to the reheater 1 in the first embodiment. This secondary reheater 30 is connected in series to the downstream side (rear stage) of the primary reheater 20, and has an inlet header pipe 30a, a heat transfer part 30b, and an outlet header part 30c. ing. The inlet header pipe 30a is connected to the pipes P4 and P5 and the heat transfer section 30b, and distributes the steam that has passed through the primary reheater 20 to the heat transfer section 30b. The heat transfer unit 30b has a plurality of heat transfer panels, is arranged inside the boiler body 110, and heats the internal steam by heat exchange with the high-temperature combustion gas in the boiler body 110. The outlet header portion 30c has a first header pipe 30c1 and a second header pipe 30c2. The outlet header part 30c is connected to the heat transfer part 30b and to the pipe P6 and the pipe P7. The steam heated in the heat transfer section 30b is merged in the outlet header section 30c and distributed again to the pipe P6 and the pipe P7. Such a secondary reheater 30 is a heat exchanger that further heats the steam that has passed through the primary reheater 20 by heat exchange.

  In such a boiler apparatus 100, the steam supplied to the superheating system 120 is heated by heat exchange and supplied to the high-pressure turbine 130 in a high-temperature and high-pressure state. Further, the steam supplied to the high-pressure turbine 130 is driven to rotate the high-pressure turbine 130, whereby the internal energy is reduced and the steam is reduced in temperature and pressure. The low-temperature steam recovered from the high-pressure turbine 130 is heated again in the reheating system 150 and supplied to the medium-low pressure turbine 140 to drive the medium-low pressure turbine 140.

The operation of the reheating system 150 in this embodiment will be described.
The low-temperature steam collected from the high-pressure turbine 130 is supplied to the primary reheater 20 through the pipe P2 and the pipe P3 branched from the pipe P1. The low temperature steam is heated by the high temperature air of the boiler body 110 when passing through the heat transfer section 20b. The steam that has passed through the heat transfer section 20b merges at the outlet header pipe 20c and is distributed to the pipe P4 and the pipe P5. The steam that has passed through the pipe P4 and the pipe P5 is further heated by being supplied to the secondary reheater 30. The steam that has passed through the heat transfer section 30b is distributed to the first header pipe 30c1 and the second header pipe 30c2 of the outlet header section 30c, and the pipe P6 and the pipe P7 from the first header pipe 30c1 and the second header pipe 30c2. Flow into.

  The secondary reheater 30 according to this embodiment is a device that further heats the steam heated by the primary reheater 20. In such an outlet header portion 30c of the secondary reheater 30, the steam temperature becomes very high. Therefore, by applying the secondary reheater 30 according to this embodiment to the boiler device 100, the outlet header portion 30c has a structure suitable for higher temperatures. For this reason, the heat resistance of the secondary reheater 30 can be improved, and higher temperature steam can be supplied to the intermediate-low pressure turbine 140.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the spirit of the present invention.

  For example, in the above embodiment, the heat transfer section 3 of the present invention has a configuration in which the odd-numbered column group 3a is connected to the first header tube 4a and the even-numbered column group 3b is connected to the second header tube 4b. However, the present invention is not limited to this, and the heat transfer panel 3A is connected to the first header pipe 4a and the second header pipe 4a so that the temperature at both ends of the steam in the first header pipe 4a and the second header pipe 4b is uniform. A configuration of selectively connecting to the header pipe 4b can be employed. For example, the heat transfer section 3 is a tube group in which a plurality of adjacent heat transfer panels 3A are combined, and the tube group is configured to have a plurality of tube groups. The tube groups are respectively connected to the first header tube 4a and the second header tube 4b. It is also possible to adopt a connected configuration.

  In the said 1st Embodiment, the structure by which the 1st header pipe | tube 4a and the 2nd header pipe | tube 4b are arrange | positioned in parallel was employ | adopted. However, the present invention is not limited to this, and for example, a configuration in which the first header pipe 4a and the second header pipe 4b are arranged to be perpendicular to each other may be employed.

  Moreover, in the said 1st Embodiment, it was set as the structure which the exit header part 4 has the 1st header pipe | tube 4a and the 2nd header pipe | tube 4b. However, the present invention is not limited to this, and when the temperature of the steam flowing into the inlet header pipe 2 is high enough to employ a pipe made of a material having high heat resistance, the inlet header pipe 2 is It is also possible to adopt a configuration having the first header pipe 4a and the second header pipe 4b.

  In addition, the heat transfer panel 3A is not limited to a shape composed of only one heat transfer tube. For example, the inlet end and the outlet end of a plurality of heat transfer tubes are each connected to one pipe, It may be set to a flat shape.

  In the above embodiment, the reheater 1 corresponds to the heat exchanger according to the present invention. However, the present invention is not limited to this, and it is possible to employ a superheater as the heat exchanger.

  Further, the shapes of the heating unit 3a1 and the heating unit 3b1 of the odd-numbered row group 3a and the even-numbered row group 3b of the heat transfer unit 3 are not limited, and various shapes can be adopted.

1 Reheater (heat exchanger)
2 Inlet header pipe 3 Heat transfer section 3A Heat transfer panel 3a Odd column group 3a1 Heating section 3b Even column group 3b1 Heating section 4 Outlet header section 4a First header pipe (outlet header pipe)
4b Second header pipe (outlet header pipe)
20 Primary reheater 20a Inlet header pipe 20b Heat transfer section 20c Outlet header pipe 30 Secondary reheater (heat exchanger)
30a Inlet header pipe 30b Heat transfer part 30c Outlet header part 30c1 First header pipe (outlet header pipe)
30c2 Second header pipe (exit header pipe)
DESCRIPTION OF SYMBOLS 100 Boiler apparatus 110 Boiler main body 120 Superheating system 130 High pressure turbine 140 Medium / low pressure turbine 150 Reheating system

Claims (6)

A plurality of heat transfer tubes arranged in a predetermined direction along with fluid flow; an inlet header tube extending along an arrangement direction of the plurality of heat transfer tubes; and connected to an inlet end of the heat transfer tubes; and a plurality of the heat transfer tubes. An outlet header pipe extending along an arrangement direction of the heat pipes and connected to an outlet end of the heat transfer pipe, wherein the plurality of the heat transfer pipes are exposed to a heat exchange target fluid,
The plurality of heat transfer tubes constitutes two or more groups,
Two or more of the inlet header pipe and / or the outlet header pipe are provided for each group.   2. The heat exchanger according to claim 1, wherein two or more of the inlet header pipes and / or the outlet header pipes provided for each group have the same pipe length and are arranged at both ends.   3. The heat exchanger according to claim 1, wherein the group is set so that the temperature of the fluid in the outlet header pipe provided in two or more for each group is uniform. 4.   The heat exchanger according to any one of claims 1 to 3, wherein the group is set so that the heat transfer tubes adjacent to each other in the arrangement direction belong to different groups.   The boiler provided with the heat exchanger as described in any one of Claims 1-4. Two heat exchangers connected in series,
The said heat exchanger connected to a back | latter stage is a heat exchanger as described in any one of Claims 1-4, The boiler of Claim 5 characterized by the above-mentioned.

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