JP2005509125A - Heat exchanger - Google Patents

Abstract

  A heat exchanger for exchanging heat between the first fluid and the second fluid is disposed in the casing so as to form a cylindrical casing (2) and a tubular space (8) extending in the axial direction. Cylindrical fluid conduit (5), at least one screw tube (9, 10) comprising a finned or corrugated tube disposed in the tubular space, and a first passage through the fluid conduit (5). Adjustable throttle means (17, 17a, 18) arranged to adjust the flow of one fluid in an adjustable manner, and adjust the flow of the first fluid through the conduit and the tubular space to adjust the first fluid flow. The heat exchange between the fluid and the second fluid flowing through the screw tube (9, 10) is adjusted.

Description

Detailed Description of the Invention

(Technical field)
The present invention relates to a heat exchanger for exchanging heat between a first fluid and a second fluid, and the heat exchanger has a first inlet and a first outlet that allow the first fluid to flow through the casing in a generally axial direction. And a generally cylindrical casing, and at least one finned or corrugated tube disposed within the casing.

(Background technology)
In this type of heat exchanger, the first fluid is flowed from one or more screw tubes to the outside or from the outside to the screw tube. The heat transfer from the first fluid to the second fluid flowing in the screw tube is not always well controlled, and the maximum efficiency is not obtained.

(Disclosure of the Invention)
(Technical problem to be solved by the invention)
The object of the present invention is to ensure that the flow of the first fluid such as exhaust gas from a natural gas combustion turbine, an internal combustion engine, an incinerator, a furnace, a burner, etc. is well controlled and efficiently around the fin tube. It is to provide a heat exchanger of this kind that is capable of efficiently transferring heat from a first fluid to a second fluid such as water.

(Solution)
This object is achieved by the present invention having the following configuration. That is, a cylindrical fluid conduit is provided generally coaxially with the casing to define a first tubular space extending axially between the casing and the conduit, the conduit comprising a second inlet and a second outlet. And the first tubular space has a third inlet and a third outlet to allow the first fluid to flow substantially axially and to pass the second fluid. At least one screw tube composed of a finned or corrugated tube having a fourth inlet and a fourth outlet is disposed in the first tubular space coaxially therewith.

  With this configuration, the first fluid is flowed so that heat exchange is performed very efficiently around the winding of the screw tube composed of the finned tube. This configuration also reduces the space required for heat exchange, the so-called “footprint”.

  According to the present invention, the heat exchanger adjusts the flow of the first fluid passing through the conduit in an adjustable manner and the second restriction restricting the flow of the first fluid through the first tubular space in an adjustable manner. It further comprises at least one means.

  With this configuration, the flow of the first fluid bypasses the screw tube composed of the finned tube, and the heat transfer to the second fluid is reduced according to the heating requirement of the second fluid. In addition, the pressure loss from the inlet to the outlet of the casing is reduced by bypassing the finned tube, which is a start-up of a gas-fired turbine, for example, that generates a first fluid in the form of exhaust gas by combustion of the gas. Desirable for.

  According to a preferred embodiment of the heat exchanger according to the present invention, the first throttle means comprises a first butterfly valve, preferably arranged in the vicinity of the second inlet or the second outlet, the second throttle means. Preferably comprises a second butterfly valve disposed in the vicinity of the third inlet or the third outlet. This provides a simple mechanism that is easy to adjust and control.

  According to an alternative embodiment, the first throttling means preferably comprises a first butterfly valve arranged in the vicinity of the second inlet or the second outlet, and the second throttling means comprises the first throttling means. A first fluid flow through the first tubular space from a heating position having a planar dimension corresponding to a cross-section of the one tubular space and not substantially impeding the flow of the first fluid through the first tubular space; It is arranged to be displaced to a bypass position that substantially impedes. According to this embodiment, the required space is reduced.

  In another preferred embodiment, the first diaphragm means and the second diaphragm means are provided with a stationary plate fixedly provided with first and second openings, and third and fourth openings. Comprising one or two moveable plates, said stationary plate obstructing the second and third inlets or outlets so that the flow of the first fluid through the conduit and the first tubular space is the first and second respectively. The movable plate is arranged such that the third opening coincides with the first opening and the fourth opening overlaps with the stationary plate not coincident with the second opening from the bypass position. The first opening coincides with the second opening, and the third opening is displaceable to a heating position that overlaps the stationary plate that does not coincide with the first opening, and is preferably rotatably arranged. This embodiment of the first and second throttling means requires a minimum amount of space and is particularly suitable for precise adjustment of the bypass flow through the conduit relative to the heat transfer flow through the tubular space.

  A preferred embodiment of the heat exchanger according to the present invention preferably further comprises a motor driving means for adjusting the throttling action of the first throttling means and the second throttling means. The flow rate ratio of the first fluid passing through the third inlet can be substantially arbitrarily obtained between the maximum value and the minimum value. The minimum value is substantially zero. Accordingly, the first fluid can be distributed at an arbitrary flow ratio between the bypass conduit and the tubular space, and the output of the heat exchanger can be easily and precisely controlled according to the heat transfer requirement from the first fluid. . By substantially bypassing all of the first fluid, no heat is transferred to the second fluid, which is not necessary when heat transfer to the means outside the heat exchanger, no temperature rise is required. Advantageously, steam is generated in the threaded tube.

  A preferred embodiment of the heat exchanger according to the invention comprises two or more concentrically arranged screw tubes, the screw tubes being adjacent to each other, forming a second tube gap extending in the axial direction. Such that the outer surface of the conduit is radially spaced to form a third tube gap extending axially from a nearby screw tube, the dimensions of the second and third tube gaps being the first A predetermined pressure loss is generated with respect to the first fluid having a predetermined flow rate passing through the tubular space.

  This keeps the pressure loss from the first inlet to the first outlet for a given flow of the first fluid to a minimum without substantially reducing the efficiency of the heat exchanger. This is particularly important for the gas combustion turbine that is the source of the first fluid. This is because gas turbines are particularly sensitive to exhaust outlet back pressure.

  The adjacent turns of the screw tube are preferably separated in the axial direction so as to form a spirally extending gap. Thereby, any axial extension or contraction due to the temperature difference of at least one of the casing and the conduit with respect to the screw tube is absorbed by the helically extending gap.

  A preferred embodiment of the heat exchanger according to the present invention comprises three or more screw tubes arranged concentrically, the inner diameter of the finned tube constituting the screw tube is preferably the same, and the third throttle means is , Provided in the tube constituting the screw tube radially inward from the outermost screw tube to compensate for a short length compared to the outermost screw tube and increase the pressure loss, The flow rate of the second fluid through all the threads is substantially the same for a given uniform pressure at the fourth inlet of the second fluid. Thereby, the heat transfer efficiency of each screw tube becomes substantially the same without changing the diameter of each screw tube.

  According to a preferred embodiment of the heat exchanger according to the present invention, the third throttle means is configured by reducing the cross-sectional area of the flow of the second fluid with respect to the inner cross-sectional area of the tube, Preferably, the heat exchanger further includes an inlet header tube and an outlet header tube that communicate with each other via communication ports corresponding to the fourth inlet and the fourth outlet of all the tubes, respectively, and the reduction of the cross-sectional area of the flow is The size of the communication port of at least one of the inlet header tube and the outlet header tube is reduced. This is a particularly simple and inexpensive way to compensate for different lengths of different screw tubes.

  When the heat exchanger according to the present invention is used to generate steam, each screw tube is advantageously constructed by spirally winding two or more finned tubes adjacently at the same pitch. The This increases the number of channels and is advantageous for large volume expansion of water in the screw tube due to the generation of steam.

  Another aspect of the present invention is a heat exchanger according to the present invention and a combustion unit that generates combustion gas such as a natural gas combustion turbine, an internal combustion engine using gasoline, diesel oil, or natural gas, a furnace, a burner, or an incinerator. With respect to the combination, this combination comprises connecting means for connecting the exhaust gas outlet of the combustion means to the second and third inlets of the heat exchanger so that the exhaust gas becomes the first fluid.

  The combination according to the present invention includes heat exchange means for performing heat exchange between at least one of the second fluid and the third fluid and between the heat exchanger and the surrounding environment and communicating with the fourth outlet; Measuring means for measuring the heat exchange rate of the heat exchanging means, signal output means for outputting a signal representing the result measured by the measuring means, and the first and second restricting means in response to the signal First control means for controlling the adjustment.

  The combination according to the present invention preferably further comprises a second control means for controlling the adjustment of the first throttle means so that the throttle effect is minimized when the combustion means is started.

  Yet another aspect of the present invention relates to a method for manufacturing a heat exchanger according to the present invention, the method comprising procuring a first length of finned or corrugated tube and a substantially cylindrical surface. A main body having a step, a step of procuring a rotating means for rotating the tube and the cylindrical surface relative to each other, a step of arranging an introduction portion of the tube that contacts the cylindrical surface, and the cylindrical shape Rotating the surface and the tube introduction portion so that the first length of tube is spirally wound on the cylindrical surface to form a first screw tube. This makes the heat exchanger according to the invention particularly simple, precise and inexpensive.

  The method of manufacturing a heat exchanger of the present invention having two or more concentric screw tubes includes a step of procuring spacing means, a step of attaching the spacing means to the first screw tube, and a fin having a second length. Alternatively, a step of procuring a corrugated tube, a step of disposing an introduction portion of the fin tube having the second length in contact with the spacing means, and introduction of the first screw tube and the second length tube Rotating the tube relative to each other, winding the second length tube spirally on the spacing means, and forming a second screw tube spaced radially from the first screw tube. It is preferable to further provide.

  In order to avoid inaccuracy of the diameter of the screw tube and other disadvantages, the manufacturing method according to the present invention further comprises the steps of fixing the screw tube to the main body, and annealing and heat-treating the main body and the screw tube. preferable. Alternatively, it is preferable to further include a step of fixing the second screw tube to at least one of the main body and the first screw tube, and a step of annealing and heat-treating the main body and the first and second screw tubes. This makes it possible to easily, inexpensively and efficiently avoid changes in diameter due to the elasticity and stress in the steel of the screw tube.

(Best Mode for Carrying Out the Invention)
1 and 4, a heat exchanger 1 according to the present invention includes a cylindrical outer casing 2 having a flanged inlet 3 and a flanged outlet 7. A cylindrical inner casing having an inlet 6 and an outlet 7, i.e. a conduit 5, is arranged concentrically with the cylindrical outer casing 2 to define a tubular space 8, in which a tube 2 with fins is formed. Two screw tubes (coils) 9 and 10 are arranged. The finned tube comprises a tube 11 with fins 12 disposed generally across the tube axis.

  The screw tubes 9 and 10 made of finned tubes are arranged concentrically with each other and coaxially with the outer casing 2 and the inner casing 5. The flanged outlet header tube 13 and the flanged inlet header tube 14 communicate with the inside of the tubes 11 of the screw tubes 9 and 10 through the openings 15 and 16, respectively.

  The butterfly valve 17 (bypass valve) is pivotally supported on the shaft 18 of the outlet 7 of the conduit 5, and the intermediate position between the position where the butterfly valve 17 completely closes the outlet 7 and the position where it completely opens is indicated by a broken line 17a. It is shown. Semi-circular rings 19, 20 that abut the rim of the butterfly valve 17 are arranged in the vicinity thereof to ensure a good closing function of the butterfly valve 17.

  The heat exchanger 1 is primarily intended for use in combination with a natural gas combustion turbine to recover and use the heat of the exhaust gas of a natural gas combustion turbine, but in essence, an internal combustion engine, furnace, burner, It can be used in combination with any means for generating heated gas such as an incinerator.

  In the maximum output operation of the heat exchanger 1, the butterfly bypass valve 17 is in the closed position indicated by the solid line in FIG. 1 so that all the gases introduced from the gas turbine to the inlet 3 are indicated by the solid arrow. It flows through the tubular space 8 so as to pass through the finned tubes 9 and 10. The water to be heated is introduced into the screw tubes 9 and 10 through the inlet header tube 14, heated by heat transferred from the exhaust gas to the water through the fins 12 and the tubes 11, and then discharged through the openings 15 and 16. The

  The heated water is carried to an external heat exchange means (not shown) to transfer part of the heat to other fluids or the surrounding environment, particularly the radiator of the building heating system or district heating system.

  (In order to start the turbine easily, the pressure loss through the heat exchanger 1 should be minimized.) When starting the gas turbine, or if the external heat exchange means does not require the full heat capacity of the heat exchanger 1, The butterfly valve 17 is a shaft 18 that allows some or all of the exhaust gas from the gas turbine to flow into the inner conduit 5 as indicated by the dashed arrows, bypassing the tubular space 8 and the threads 9 and 10. Is rotated around.

  Thereby, the pressure loss through the heat exchanger 1 is reduced, and the heat transfer to the water in the tubes 9 and 10 is reduced. The butterfly valve 7 can be referred to as throttling means and may be replaced by other means as described below in connection with FIGS.

  Referring to FIGS. 2 and 3, the strip 12a made of carbon steel is cut transversely to form a plurality of tabs or fingers 12b and bent transversely with respect to the plane of the strip to alternate. Then, it is welded spirally to the surface of the tube 11 by seam welding 12c. This provides a very efficient heat transfer from the hot exhaust gas to the finger 12b and thus to the tube 11. Instead of the helically wound tooth-like fins shown in FIGS. 2 and 3, other forms such as disk-like fins and corrugated fins can be used.

  Next, referring to FIG. 14, the tube 11 is welded around the openings 15, 16 of the inlet header tube 14, whereby the inside of the tube 11 communicates with the inside of the inlet header tube 14. The screw tubes 9 and 10 are suspended and attached to a beam 22 welded to the outer casing 2 and the conduit 5. The beam 22 is welded to two rings 23 and 24 that are press-fitted around the fins 12 b of the screw tubes 9 and 10. A similar attachment is made on the bottom of the heat exchanger near the outlet header tube 13.

  Referring to FIG. 8, the positions of the screw tubes 9 and 10 with respect to the outer casing 2 and the inner casing 5 and each other and the winding gap of each screw tube are illustrated.

  The inner screw tube 10 is spaced from the outer screw tube by a tube spacing having a thickness or radial dimension t1, and the inner screw tube 10 is spaced from the outer tube by a tube spacing having a thickness or radial dimension t3. Separated from the exterior. The outer screw tube 9 is not separated from the inner surface of the outer casing 2, that is, is in contact with the outer casing 2.

  The interval t1 is such that the pressure loss in the tubular space 8 is maintained at a level that is acceptable for the optimum operation of the gas turbine (or other hot exhaust gas generating means) that supplies the exhaust gas to the heat exchanger 1. , T3 are selected. The heat exchange efficiency of the heat exchanger 1 is not substantially affected by the intervals t1 and t3. On the other hand, the operation test shows that if there is a gap between the outer casing 2 and the outermost screw tube 9, the efficiency of the heat exchanger 1 is considerably reduced. These two phenomena are due, at least to some extent, to turbulent flow between the screw tubes 9 and 10 and between the conduit 5 and the screw tube 10, while on the other hand, the tube between the outer screw tube 9 and the casing 2. The cause is laminar flow in space.

  There are several parameters that determine the distance t1 between the screws 9 and 10 and the distance t3 between the innermost screw 10 and the conduit 5. The two most important considerations or parameters are the following exhaust gas pressure drop and heat transfer coefficient.

Exhaust gas pressure drop The exhaust gas pressure drop, i.e., pressure loss, remarkably depends on the exhaust gas velocity and the heating surface configuration of the screw winding. The velocity depends on the cross-sectional area of the free gas flow (total cross-sectional area for the gas flow between the tube and the fin).
Δp = ζ · 1/2 · ρ · w2
Δp: exhaust gas pressure drop [Pa]
ζ: Pressure drop coefficient, this is the form (fin shape,
Tube diameter, linear / zigzag arrangement,
Depends on the number of turns
ρ: density of the gas at the average temperature between the inlet 3 and the outlet 4 [kg / m ³ ]
w: exhaust gas speed [m / s]

    In most cases, the exhaust gas pressure drop allowed in the heat exchanger and boiler behind the gas turbine (also engine) is completely limited. For gas turbines, it is very important to minimize the pressure drop of the exhaust gas, since the power generation of the turbine (and hence the efficiency of the turbine) depends significantly on the back pressure. For the heat exchanger according to the present invention, the allowable exhaust gas pressure drop is preferably limited to be less than 500 Pa (50 mm water column), with very low exhaust gas speeds and such large helix. The distance between the tubes is given (instead of many screw tubes giving large gas cross sections and large diameter units).

Heat transfer rate In general, the heat transfer rate should be as high as possible to reduce the heating surface area. The heat transfer rate increases as exhaust gas velocity increases and turbulence increases. For the selected heating surface (helically wound serrated finned tube), the flow turbulence is very good and generally provides a high heat transfer rate even at low exhaust gas velocities.

  Also, designing the heat exchanger with the intervals t1, t3 according to the present invention is advantageous from a manufacturing point of view, since the screw tubes can be individually inserted into the casing, so that they abut each other. This is evident when compared to a screw tube that is designed to be nested with each other and that must be treated and inserted as a unit with several screws.

  Referring to FIG. 8, the space extending in a spiral shape is provided between adjacent windings of the screw tubes 9, 10, and the thickness of the space, that is, the dimension in the axial direction is t2. This interval t2 between the windings causes thermal expansion and contraction of the casing 2 and the conduit 5 in the axial direction relative to the screw tubes 9 and 10 without causing unacceptable stress. This is because a difference in expansion or contraction is absorbed by a change in the space t2 between the windings of the screw tube.

Examples Next, the basic technical specifications for the combination according to the invention of a two-screw heat exchanger according to the invention and a gas-fired turbine are listed as non-limiting examples.

Heat exchanger dimensions / height excluding inlet: 1550mm
・ Diameter excluding insulator: ............ 633mm
・ Insulator: ........ 100mm, covered with zinc iron plate ・ Gas outlet flange: ...... DN450, DIN86044
・ Water inlet / outlet joint: Carbon steel pipe, OD 60.5 × 3.6mm, 2 "RGW
・ Case thickness (inside 5 and outside 2): 5mm
・ Weight of heat exchanger excluding water: 475kg
・ Weight of heat exchanger including water: 500 kg
・ Outer diameter of tube 11: 38mm
・ Thickness of tube material: 3.6mm
・ Fin type: ..... height of fins and fins wound in serrated spiral ... ............ 15mm
・ Fin density: 250pc / m
・ Fin thickness: 1mm
・ Tube and fin materials: carbon steel ・ Tube arrangement: ... ........... Inline (series)
・ Number of coaxial and concentric threads: 2
・ Number of rolls: .................................... 10
・ Tube pitch in the gas direction: 70mm
-Free space t2 between fins on screw winding body in gas direction: 2mm
・ Bypass channel (inner casing 5) diameter: ... 323.9mm
・ Length of inner casing 5 including bypass valve: 860mm
・ The center diameter of the inner screw 10: ...... 401mm
・ Center diameter of outer screw tube 9: ............ 555mm
-Free space t3 between the inner casing 5 and the fin on the inner screw 10:
.................... 4.5mm
・ Free space t1 between fins on two screw tubes: 9mm
-Free space between the fin on the outer screw tube and the inner surface of the outer casing 2:
.................... 0mm
-Size of holes 15 and 16 of header 13 for screw connection (both screws): 30.8mm

Process data ・ Micro gas turbine type: ............ HONEYWELL Parallon 75
・ Maximum output from gas turbine: 75kW (e)
・ Exhaust gas flow rate: 0.68kg / s
・ Exhaust gas inlet temperature to the heat exchanger: 246 ℃
・ Exhaust gas outlet temperature from heat exchanger: 90 ℃
・ Exhaust gas pressure loss across the heated surface: 300 Pa
・ Heating capacity of heat exchanger: ............... 120kW
・ Water inlet temperature: 50 ° C
・ Water outlet temperature: 70 ° C
・ Flow rate of water, approximate value: 1.44kg / s
・ Pressure drop, water side: ............ 0.2bar

  Referring to FIG. 5, an embodiment of a heat exchanger 31 according to the present invention having three concentric threads 32-34 is shown using the same reference numerals for elements similar to those of FIG. . The main difference between the embodiment of FIG. 1 and the embodiment of FIG. 5 is that, apart from the number of threads, the inlet openings 35, 36, 37 of the outlet header tube 38 are described above as described below. This means that the sizes are different in order to compensate for the difference in the screw length between the screws 32 to 34.

  The lengths of the tubes 11 of the different screw tubes 32 to 34 are different, and all the screw tubes are connected to each other by the outlet header 38 and the inlet header 39. Thus, the flow is distributed in the threads so as to give the same pressure loss between each of the threads.

  In this way, the inner screw tubes 33 and 34 (the second fluid (typically water) therein has a shorter flow path than the outermost screw tube 32) are more than the outer screw tube 32. Can transport a lot of water. At this time, the water in the screw tubes 32, 33, and 34 is not heated to the same temperature, and the heat contained in the first fluid (for example, exhaust gas from the gas combustion turbine) is in an asymmetric reduced recovery state. .

  Therefore, it is desirable to adjust the flow rate through the screw tube so that the best possible heat recovery is obtained with the best possible temperature distribution in both water and exhaust gas. This is accomplished by creating an extra pressure loss in the inner threads 33, 34 relative to the outer threads 32.

This can be achieved in two ways:
This is achieved by providing different diameters for the tube of the screw tube. This is undesirable from a practical point of view. However, except when a few different tube diameters are allowed and many concentric threads are required.
Achieved by installing a throttling or blocking means in the tube or at the inlet or outlet of the tube. As shown in FIGS. 5 and 6, this can be accomplished by providing the outlet header tube 38 with openings 35-37 and 40-43, each having a different diameter. The diameter of the individual openings is determined based on the tube diameter and tube length in the individual screw tubes of the heat exchanger. When the inner diameters of the four screw tubes are all 56 mm, as an example of the four opening diameters shown in FIG. 6, the opening 40 is 56 mm, the opening 41 is 13 mm, the opening 42 is 11 mm, and the opening 43 is 9 mm. Other throttling or blocking means well known in the art may be used to achieve different pressure loss factors for individual screw tubes.

  Referring now to FIG. 7, the inner screw tube adjacent to the inner conduit 5 comprises two parallel wound finned tubes 50,51. The tubes 50 and 51 provide two parallel flow paths for the second fluid (typically water) indicated by arrows R1 and R2.

  This embodiment is intended for use in steam generation, but in addition to pressure loss at the inner surface of the tube, large-scale volume expansion of the material inside the tube (from liquids) to accommodate increased flow rates and flow rates. Steam, change from water to steam) needs to be considered. Accordingly, to provide sufficient internal flow cross-sectional area within the tube, it is necessary to use a larger tube diameter or multiple threads or otherwise provide more flow paths.

  Unlike providing a number of screws, like the screw shown in FIG. 7, having a number of parallel extending windings provides more channels. That is, they are “twisted” threads that have the same thread diameter and a large pitch. Thereby, a larger internal cross-sectional area is achieved without having many screws with an outermost screw tube of large diameter and thus without having an outer casing 2 (large installation area). This smaller footprint, i.e. the small outer diameter of the heat exchanger, has important advantages both in the end user and in manufacturing, assembly and transportation. For a given output, the axial length of the heat exchanger, i.e. the height of the heat exchanger, will of course be larger, which is usually essential during production or even for the end user. It will not be a problem.

  Referring to FIGS. 9-13, various embodiments of throttling means for restricting the flow of the first fluid (typically exhaust gas) passing through the conduit 5 and the tubular space 8 are shown, respectively.

  In the embodiment of FIG. 9, butterfly valve 17 cooperates with ring 52. The ring 52 is suspended by three steel wires 53 attached at equal distances along the ring 52. The wire 53 extends to the shaft 18 via the pulley 54.

  In the state shown by the solid line, the butterfly valve 17 is closed and no exhaust gas flows through the conduit 5, while the ring 52 is at the highest position and passes through the tubular space 8. Don't squeeze the flow.

  In the state indicated by the dotted line, the butterfly valve 17a functions like a bypass valve and does not restrict the flow of exhaust gas passing through the conduit 5. On the other hand, the ring 52 a is in a completely throttled state supported by the tightening ring 55, thereby preventing the flow of exhaust gas passing through the tubular space 8.

  The shaft 18 can be moved manually or by a motor, pneumatic or hydraulic mechanism. In the simplest form, the wire is wound up on a pulley (not shown) on the shaft so that rotation of the shaft 18 to open the butterfly valve 17 automatically lowers or reverses the ring 52. Rewind.

  When the external heat consuming means connected to the heat exchanger 31 does not require heat, the butterfly valve 17 is in the fully open position (17a) and the ring 52 is in the lowered fully closed position ( 52a). Thus, all exhaust gas is bypassed through the conduit 5. As a result, the water in the finned screw tube is not heated, and as a result, no external cooling means for avoiding overheating of the water is required.

  In this way, a very simple means of adjusting the heat output of the heat exchanger 31 is provided. A temperature sensor and a transmitter (not shown) may be provided in the outlet header 38 to transmit a signal to the actuator (electric motor) (not shown) with respect to the shaft 18. As a result, if the temperature measured at the outlet header does not match the desired temperature, the shaft rotates in the corresponding direction of either opening or closing the bypass valve 17. Many different control circuits are conceivable depending on the requirements of the end user and the configuration of the external heat consuming device connected to the heat exchanger 31.

  Referring to FIGS. 10 and 11, there are shown an elevation view and a plan view of the first throttle means and the second throttle means for exhaust gas flow passing through the internal conduit and the tubular space, respectively. The inner conduit 5 is connected to another conduit 56 having an outlet 57, in which a butterfly valve 58 is rotatably attached to a shaft 59. The outlet 57 communicates with the outlet 4 of the casing 5. The butterfly valve 58 is rotated by the shaft 59 from the illustrated closed position where the outlet 57 is completely blocked to an open position where the flow of exhaust gas through the outlet 57 is not hindered.

  The tubular space 8 is connected to a space 60 formed by an extension of the outer casing 2. The space 60 communicates with the outlet 4 through an opening 61 in the plate 62. The butterfly valve 63 is mounted on the shaft 59 in the opening 61, and the butterfly valve 63 is rotated by the rotation of the shaft 59, so that the exhaust gas flows from the tubular space 8 through the space 60 and the opening 61. From the fully open position shown in the figure, which is not blocked, the exhaust gas flow through the opening 61 is completely blocked. The shaft 59 is connected to an electric motor 64 so as to rotate in the opposite direction in order to rotate the valves 58 and 63 between the two positions described above or to an intermediate position therebetween.

  Referring to FIG. 12, in this embodiment, the butterfly valves 58 and 63 of the embodiment in FIGS. 10 and 11 are replaced by a butterfly valve 65 and two butterfly valves 66, respectively. The operation of 66 and the shaft 59 is the same as described for the embodiment of FIGS.

  Referring to FIG. 13, in the same heat exchanger embodiment as shown in FIG. 1 or FIG. 4 (except for the butterfly valve 17 above), a circular stationary plate 70 is connected to the outlet of the conduit 5 and the tubular space 8. Is arranged horizontally at the annular outlet. The plate 70 includes an opening 71 that communicates with the inside of the conduit 5 and an opening 72 that communicates with the tubular space 8.

  A rotatable circular plate 73 is arranged on the plate 70 on the pivot shaft 74. The plate 73 includes an opening 75 having the same shape and distribution as the opening 72 of the plate 70, and an opening 76 having the same shape and distribution as the opening 71 of the plate 70. An electric motor 77 is arranged to rotate the rotatable plate 73 in both directions.

  In the position of the rotatable plate shown in FIG. 13, the openings 71 and 76 coincide, i.e. overlap each other, so that the exhaust gas passes through the conduit 5 below these coincident openings, It flows without being actually disturbed. On the other hand, since the opening 72 and the opening 75 are not connected to each other at all, the flow through the tubular space 8 is blocked. By rotating the plate 73 using the motor 77, the openings 72 and 75 can coincide with each other to obtain a position where the flow through the tubular space is relatively unimpeded, and the openings 71 and 76 are provided. Since they are not connected to each other at all, it is possible to obtain a position where the flow through the conduit 5 is completely blocked.

  Alternatively, the lower plate 70 may be a rotatable plate, so that the pressure from the exhaust gas presses the plate 70 against the stationary plate 73, and the sealing effect of the adjacent plates 70, 73 is mutually reduced. Improve. Sealing between the plates may be accomplished in many other ways apparent to those skilled in the art.

  Referring to FIG. 15, a method according to the invention for producing a heat exchanger according to the invention (the embodiment of FIG. 5) is illustrated.

  The cylindrical main body 80 includes a steel plate 81 having a thickness of 10 mm, a steel rod 82 inserted between free edges extending in the axial direction of the plate 81, and the plate 81 in the illustrated cylindrical shape. In order to hold | maintain the rod 82, it is comprised by the fastening strap (band | wire) or the wire which is not shown in figure which extends in the circumferential direction.

  The inner screw tube 34 is spirally wound around the main body, ie, the core 80, and the introduction end (not shown) of the pipe 11 of the screw tube 34 and the rear end 11 a are welded to the end portion and the main body 80. The bracket 80 or the rod 83 is attached to the main body 80. The fastening strap described above is located outside the region of the main body 80 and is covered by the screw tube 34.

  The four cylindrical plates 84 have a quarter circular cross section and a thickness equal to the required radial dimension t1 (see FIG. 8), and are arranged between adjacent axially extending edges of the plate 84. It is arranged on the outer surface of the screw tube 33 together with the rod 85. The plate 84 and the rod 85 are held in proper positions by fastening straps or wires extending in the circumferential direction (not shown). The rod 85 has an oval or elliptical cross section so that the main cross sectional dimension is a tangent to the circumference of the plate 84, and is disposed between the plates 84.

  The next screw tube 33 is wound around the plate 84 and the rod 85 in a spiral shape. The introduction end and the rear end of the screw tube 33 are welded to one of the plates 84 by a bracket or rod 83 in the same manner as the winding and attachment of the inner screw tube 34.

  The above process is repeated for the next screw tube 32. If more than four screws are needed, the above process is repeated for such additional screws.

  The unit comprising the main body 80, the screw tubes 32-34 and the plate 84 with the rod 85 is then used to avoid elastic expansion of the screw tube diameter and also to remove potential damaging stresses. Therefore, annealing and heat treatment are performed.

  After annealing, the object attached by the bracket 83 is removed. The rod 85 is rotated so that the major dimension of the oval or elliptical cross section is oriented radially, thereby forcibly expanding the threads 32-34 slightly and removing the cylindrical plate 84. it can. Finally, the rod 82 is removed so that the body 80 can be removed. The tubes 32 to 34 are now ready to be inserted into the casing 2 where the conduit 5 is located inside the inner tube 34.

  The heat exchanger according to the invention is particularly suitable for use in a combination or system comprising a gas combustion turbine (or an internal combustion engine that utilizes natural gas as fuel). In addition, such systems are particularly suited for use in, but not limited to, systems for small-scale production that combine electricity and heat, such as large buildings, hospitals, and small district heating systems. Well suited.

Referring now to FIG. 16, a system or combination according to the present invention including a heat exchanger, gas combustion turbine and external heat consuming device according to the present invention is illustrated with the following features.

(Possibility of industrial use)
The system can include other exhaust gas generators. In addition, there are many heat exchanger bypass valves (and a heat exchanger throttle valve for restricting the flow rate of fluid through a tubular space including a finned screw tube) depending on the form of the heat consumption device of the end user. Can be adjusted in various ways.

It is a partially broken elevation view of a first embodiment of a heat exchanger according to the present invention. It is a top view which shows the external shape of the fin of the fin tube by this invention. It is a top view which shows the external shape of the fin of the fin tube by this invention. FIG. 2 is a bottom view of the embodiment of FIG. 1. It is a partially broken elevation view of a second embodiment according to the present invention. FIG. 3 shows an inlet header tube of an embodiment of a heat exchanger with a screw tube consisting of four fin tubes arranged concentrically according to the present invention. It is a fracture elevation view of a third embodiment of a heat exchanger according to the present invention. It is an enlarged dimension figure which shows the clearance gap between the finned tube of the screw tube in embodiment of FIG. FIG. 6 is a partially cutaway sectional view showing a first example of the throttle means according to the present invention at the top of the embodiment of FIG. 5; It is a partially broken elevation sectional view showing a second example of the throttling means according to the present invention at the top of the fourth embodiment of the heat exchanger. FIG. 11 is a top view of the embodiment of FIG. 10. FIG. 6 is a partially cutaway sectional view showing a third embodiment of the throttle means according to the present invention. It is a top view which shows the 4th Example of the aperture means by this invention. It is a partially broken enlarged perspective view of the header tube and fixing means for the screw tube of the embodiment of FIG. It is a top view which shows the manufacturing method by this invention of embodiment of FIG. It is a figure which shows one Embodiment of the control means for adjusting the aperture means by this invention.

Claims (43)

A heat exchanger for exchanging heat between a first fluid and a second fluid,
A substantially cylindrical casing having a first inlet and a first outlet and allowing the first fluid to flow substantially axially;
A cylindrical fluid conduit provided substantially coaxially with the casing in the casing,
A first tubular space extending in an axial direction is defined between the casing and the conduit, the conduit having a second inlet and a second outlet for allowing the first fluid to flow substantially axially, and One tubular space has a third inlet and a third outlet to allow the first fluid to flow substantially axially;
Comprising at least one screw tube comprising a finned or corrugated tube;
The screw tube is disposed coaxially with the first tubular space, and has a fourth inlet and a fourth outlet through which the second fluid flows in the finned or corrugated tube. Features heat exchanger. The heat exchanger according to claim 1,
It further comprises at least one of first restricting means for adjusting the flow of the first fluid passing through the conduit and second restricting means for adjusting the flow of the first fluid passing through the first tubular space. A heat exchanger characterized by having The heat exchanger according to claim 2,
The first throttle means preferably comprises a first butterfly valve disposed in the vicinity of the second inlet or the second outlet, and the second throttle means is preferably the third inlet or the third outlet. It consists of a 2nd butterfly valve arrange | positioned in the vicinity. The heat exchanger according to claim 2,
The first throttle means is preferably a first butterfly valve disposed in the vicinity of the second inlet or the second outlet, and the second throttle means is a plane corresponding to the cross section of the first tubular space. Bypass having a general dimension and substantially preventing the flow of the first fluid through the first tubular space from a heating position that does not substantially prevent the flow of the first fluid through the first tubular space. A heat exchanger characterized by being arranged to be displaced to a position. The heat exchanger according to claim 2,
The first diaphragm means and the second diaphragm means include a stationary plate fixedly provided with first and second openings, and one or two stationary holes provided with third and fourth openings. With a movable plate,
The stationary plate prevents the second and third inlets or outlets so that the flow of the first fluid through the conduit and the first tubular space respectively causes the first and second in the stationary plate. The movable plate is disposed on the stationary plate so that the third opening coincides with the first opening and the fourth opening does not coincide with the second opening. Displaceable, preferably rotatable, from a bypass position to a heating position on the stationary plate where the fourth opening coincides with the second opening and the third opening does not coincide with the first opening Heat exchanger characterized by being made. The heat exchanger according to any one of claims 2 to 5,
In order to adjust the throttling action of the first throttling means and the second throttling means, the heat exchanger is preferably further provided with motor operating means. The heat exchanger according to any one of claims 2 to 6,
The throttle means and the motor driving means can obtain the flow rate of the first fluid passing through the second inlet and the third inlet substantially arbitrarily between a maximum value and a minimum value. A heat exchanger characterized by that. The heat exchanger according to claim 7,
The heat exchanger according to claim 1, wherein the maximum value is substantially zero. The heat exchanger according to any one of claims 1 to 8,
It is provided that two or more screw tubes arranged concentrically, the adjacent screw tubes are separated from each other in the radial direction, and a second tubular space extending in the axial direction is formed between the adjacent screw tubes. Features heat exchanger. The heat exchanger according to any one of claims 1 to 9,
The outer surface of the conduit has a third tubular space extending in the axial direction between the outer surface and the adjacent screw tube, spaced radially from the screw tube adjacent to the outer surface. Features heat exchanger. The heat exchanger according to claim 9 or 10,
The radial dimensions of the second tubular space and the third tubular space are such that a predetermined pressure loss is obtained with respect to the first fluid at a predetermined flow rate passing through the first tubular space. Features heat exchanger. The heat exchanger according to any one of claims 1 to 11,
A heat exchanger characterized in that individual windings adjacent to each other of the screw tube are spaced apart from each other in the axial direction, and a space extending in a spiral shape is provided between the adjacent windings. . The heat exchanger according to any one of claims 1 to 12,
Three or more screw tubes arranged concentrically, and the inner diameter of the finned tube constituting the screw tube is preferably the same, and the third throttling means is located radially inward from the outermost screw tube. In a tube constituting a certain screw tube, it is provided to compensate for a short length compared to the outermost screw tube and increase the pressure loss, and as a result, the second fluid passing through all the screw tubes. The flow rate of the second fluid is substantially the same for a predetermined uniform pressure at the fourth inlet of the second fluid. The heat exchanger according to claim 13,
The heat exchanger according to claim 3, wherein the third throttle means is configured by reducing a cross-sectional area of the flow of the second fluid with respect to an inner cross-sectional area of the tube. The heat exchanger according to claim 14,
An inlet header tube and an outlet header tube are further provided, and the inlet header tube and the outlet header tube are respectively connected to the fourth inlet and the fourth outlet of the whole tube through corresponding communication openings of the header tube. The flow cross-sectional area is reduced by the reduced size of the communication opening in at least one of the inlet header tube and the outlet header tube. . The heat exchanger according to any one of claims 1 to 15,
The screw tube includes two or more spirally wound finned tubes extending adjacent to each other at the same pitch. The heat exchanger according to any one of claims 1 to 16, an exhaust gas such as a natural gas combustion turbine, an internal combustion engine using gasoline, diesel oil or natural gas, a heating furnace, a burner or an incinerator In combination with the production combustion means,
Connection means is provided for connecting an exhaust gas outlet of the combustion means to the second inlet and the third inlet of the heat exchanger so that the exhaust gas becomes the first fluid. A combination. The combination according to claim 17,
Heat exchange means for performing heat exchange between at least one of the second fluid and the third fluid and between the second fluid and a peripheral device and communicating with the fourth outlet;
Measuring means for measuring the heat exchange rate of the heat exchange means;
Signal output means for outputting a signal representing the result measured by the measurement means;
The combination further comprising first control means for controlling the adjustment of the first diaphragm means and the second diaphragm means and receiving the signal. A combination according to claim 17 or 18,
The combination further comprising second control means for controlling adjustment of the first throttle means so that the throttle effect is minimized when the combustion means is started. A combination of a heat exchanger for exchanging heat between the first fluid and the second fluid and an exhaust gas generating combustion means,
The heat exchanger is
A substantially cylindrical casing having a first inlet and a first outlet and allowing the first fluid to flow substantially axially;
A cylindrical fluid conduit provided substantially coaxially with the casing in the casing,
A first tubular space extending in an axial direction is defined between the casing and the conduit, the conduit having a second inlet and a second outlet for allowing the first fluid to flow substantially axially, and One tubular space has a third inlet and a third outlet to allow the first fluid to flow substantially axially;
Comprising at least one screw tube comprising a finned or corrugated tube;
The screw tube is disposed coaxially with the first tubular space, and has a fourth inlet and a fourth outlet through which the second fluid flows in the finned or corrugated tube. Characteristic combination. The combination according to claim 20,
It further comprises at least one of first restricting means for adjusting the flow of the first fluid passing through the conduit and second restricting means for adjusting the flow of the first fluid passing through the first tubular space. A combination characterized by The combination according to claim 21,
The first throttle means preferably comprises a first butterfly valve disposed in the vicinity of the second inlet or the second outlet, and the second throttle means is preferably the third inlet or the third outlet. A combination characterized by comprising a second butterfly valve disposed in the vicinity of. The combination according to claim 21,
The first throttle means is preferably a first butterfly valve disposed in the vicinity of the second inlet or the second outlet, and the second throttle means is a plane corresponding to the cross section of the first tubular space. Bypass having a general dimension and substantially impeding the flow of the first fluid through the first tubular space from a heating position that does not substantially impede the flow of the first fluid through the first tubular space. A combination characterized by being arranged to be displaced to a position. The combination according to claim 21,
The first diaphragm means and the second diaphragm means include a stationary plate fixedly provided with first and second openings, and one or two stationary holes provided with third and fourth openings. With a movable plate,
The stationary plate prevents the second and third inlets or outlets so that the flow of the first fluid through the conduit and the first tubular space respectively causes the first and second in the stationary plate. The movable plate is disposed on the stationary plate so that the third opening coincides with the first opening and the fourth opening does not coincide with the second opening. Displaceable, preferably rotatable, from the bypass position to a heating position on the stationary plate where the fourth opening coincides with the second opening and the third opening does not coincide with the first opening A combination characterized by being made. The combination according to claim 21,
In order to adjust the squeezing action of the first squeezing means and the second squeezing means, the combination preferably further comprises motor operating means. The combination according to claim 21,
The throttle means and the motor driving means can obtain the flow rate of the first fluid passing through the second inlet and the third inlet substantially arbitrarily between a maximum value and a minimum value. A combination characterized by that. The combination of claim 26.
A combination characterized in that the maximum value is substantially zero. The combination according to claim 21,
It has two or more screw tubes arranged concentrically, the adjacent screw tubes are separated from each other in the radial direction, and a second tubular space extending in the axial direction is formed between the adjacent screw tubes. Characteristic combination. The combination according to claim 21,
The outer surface of the conduit has a third tubular space extending in the axial direction between the outer surface and the adjacent screw tube, spaced radially from the screw tube adjacent to the outer surface. Characteristic combination. The combination of claim 28,
The radial dimensions of the second tubular space and the third tubular space are such that a predetermined pressure loss is obtained with respect to the first fluid at a predetermined flow rate passing through the first tubular space. Characteristic combination. 30. The combination of claim 29,
The radial dimensions of the second tubular space and the third tubular space are such that a predetermined pressure loss is obtained with respect to the first fluid at a predetermined flow rate passing through the first tubular space. Characteristic combination. The combination according to claim 21,
A combination characterized in that the individual windings adjacent to each other of the screw tube are spaced apart from each other in the axial direction, and a space extending spirally is provided between the adjacent windings. The combination according to claim 21,
Three or more screw tubes arranged concentrically, and the inner diameter of the finned tube constituting the screw tube is preferably the same, and the third throttling means is located radially inward from the outermost screw tube. In a tube constituting a certain screw tube, it is provided to compensate for a short length compared to the outermost screw tube and increase the pressure loss, and as a result, the second fluid passing through all the screw tubes. The flow rate is substantially the same for a predetermined uniform pressure at the fourth inlet of the second fluid. The combination of claim 33,
The combination characterized in that the third throttling means is configured by reducing the cross-sectional area of the flow of the second fluid with respect to the inner cross-sectional area of the tube. The combination of claim 34,
An inlet header tube and an outlet header tube, wherein the inlet header tube and the outlet header tube are respectively connected to the fourth inlet and the fourth outlet of the whole tube through corresponding communication openings of the header tube. The flow cross-sectional area is reduced by a reduced dimension of the communication opening in at least the inlet header tube and the outlet header tube. The combination according to claim 21,
The screw tube comprises two or more spirally wound finned tubes extending adjacent to each other at the same pitch. The combination according to claim 21,
Heat exchange means for performing heat exchange between at least one of the second fluid and the third fluid and between the second fluid and a peripheral device and communicating with the fourth outlet;
Measuring means for measuring the heat exchange rate of the heat exchange means;
Signal output means for outputting a signal representing the result measured by the measurement means;
The combination further comprising first control means for controlling the adjustment of the first diaphragm means and the second diaphragm means and receiving the signal. The combination according to claim 21,
The combination further comprising second control means for controlling adjustment of the first throttle means so that the throttle effect is minimized when the combustion means is started. The combination according to claim 20,
The exhaust gas generating combustion means is selected from the group consisting of a natural gas combustion turbine, an internal combustion engine using gasoline or diesel oil or natural gas, a heating furnace, a burner, and an incinerator. Combination to do. A method of manufacturing a heat exchanger according to any one of claims 1 to 16,
Providing a fin or corrugated tube of a first length;
Providing a body having a substantially cylindrical surface;
Comprising a rotating means for relatively rotating the tube and the cylindrical surface;
Placing the tube introduction portion in contact with the cylindrical surface;
A step of relatively rotating the cylindrical surface and the introduction portion of the tube so that the first length of the tube is spirally wound on the cylindrical surface to form a first screw tube; A method for manufacturing a heat exchanger, comprising: In the manufacturing method of the heat exchanger of Claim 40,
Providing a spacing means;
Attaching the spacing means to the first screw tube;
Providing a second length finned or corrugated tube;
Placing an introduction portion of the second length of finned tube that abuts the spacing means;
The first screw tube and the introduction portion of the second length tube are rotated relative to each other, and the second length tube is spirally wound on the spacing means. And a step of forming a second screw tube at a distance from each other. In the manufacturing method of the heat exchanger of Claim 40,
Fixing the screw tube to the body;
And a step of annealing and heat-treating the main body and the screw tube. In the manufacturing method of the heat exchanger of Claim 41,
Fixing the second screw tube to at least one of the main body and the first screw tube;
A method of manufacturing a heat exchanger, further comprising the step of annealing and heat-treating the main body, the first screw tube, and the second screw tube.

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