JP2000337781A - Module type condensation heat exchanger for recovering waste heat of low-temperature exhaust gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a module type condensation heat exchanger wherein a colliding jet having a large amount of condensed components is disposed alternately and then the heat is made to collide with flat tubes and which uses the flat tubes having heat arranged to be on the right and the left alternately so that the time of stagnation of flow is prolonged due to a high strength of a turbulent flow and large mixing of the flow caused by generation of a recirculation vortex on the downstream side from the flat tubes. SOLUTION: In the heat exchanger for recovering waste heat of low-temperature exhaust gas, a large number of flat tubes 11 for supplying a fluid which are fixed by supports 12, panels for supporting the flat tubes which support the opposite lateral sides of the flat tubes 11, panels 17 for intercepting exhaust gas which fix the panels for supporting, at the upper and lower parts thereof, leaving the remaining side to be open so as to pass main flowing gas through, and headers for mixing the fluid which are provided fop the panels for supporting the flat tubes, positioned on the opposite sides, are combined into a module, and mixing of the fluid and movement thereof are connected through connecting passages of the headers. The modules are fitted additionally in conformity with the size and the amount of heat exchange when necessary and they are arranged and connected so that the space between the flat tubes be narrowed and that the density of the flat tubes be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modular condensing heat exchanger for recovering low-temperature exhaust gas waste heat, and more particularly to a tube capable of recovering not only the present heat of exhaust gas but also residual heat from the heat exchanger for recovering waste heat. (Tube) shape is newly designed and arranged to improve heat transfer by jet collision effect, improve turbulence intensity and mixing effect by overflow motion from the rear surface of the pipe, and reduce heat transfer efficiency by non-condensable gas. The present invention relates to a reduced heat exchanger for condensing residual heat waste heat recovery.

[0002]

2. Description of the Related Art Generally, the heat transfer of a gas-liquid bundle heat exchanger for waste heat recovery is such that the heat resistance of the external gas side is 80% of the total heat resistance.
The heat resistance outside the pipe determines the performance of the heat exchanger. Normally, since the amount of energy that can be recovered in a current heat recovery heat exchanger is relatively small, the shape and arrangement of the tubes are taken into consideration when designing to minimize the pressure loss.

However, when recovering not only the current heat but also the residual heat of condensation, it is desirable to utilize the high heat transfer phenomenon of the jet impingement surface. The influence of the mass fraction of the non-condensable gas and the ambient temperature on the condensation of the exhaust gas containing the non-condensable gas is very large. In the case of film condensation, the partial pressure of the saturated vapor decreases near the interface between the vapor and the condensate, the partial pressure of the non-condensable gas increases, the saturation temperature of the vapor decreases, and the heat transfer of condensation decreases.

In the case of film condensation, the heat transfer coefficient (the amount of condensate) greatly depends on the mass fraction of non-condensable gas. For example, containing 2% of non-condensable gas reduces by about 10 to 20% depending on the temperature in forced convection, and more remarkably to about 70 to 90% in the case of a stagnant mixer.

[0005] Due to the influence of such non-condensable gas, a large number of shell tube-condensing heat exchangers are mainly used, but the heat transfer efficiency is low because the pressure loss due to the baffle is large and the dead zone is large. was there.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce the influence of non-condensable gas and pressure loss by making a flat tube a collision surface. By increasing the heat transfer coefficient at the collision surface due to the jet, the impinging jet, which has a high condensed component combined in the adjacent flat tubes after the collision, collides with the flat tubes of heat after being alternately arranged, and downstream of the flat tubes An object of the present invention is to provide a modular condensing heat exchanger using flat tubes in which heat is alternately arranged on the left and right sides so that the turbulence intensity is high and flow mixing is large due to the generation of recirculation vortices, so that the flow residence time is long.

[0007]

SUMMARY OF THE INVENTION The present invention provides an impinging jet having a flat tube as an impinging surface, increasing the heat transfer coefficient at the impinging surface by the impinging jet, and having a high condensed component combined by the adjacent flat tubes after the impingement. After being alternately arranged, the flattened tube impinges on the flat tubes of heat, and the turbulence intensity is high due to the generation of recirculation vortices downstream of the flat tubes and the flow mixing is large. Are arranged and fixed by a support base that plays a role of suppressing flow-promoting vibrations, a plurality of flat tubes for supplying fluid, flat panel supporting panels for supporting both side surfaces of the flat tubes for supplying fluid, The panel for fixing the exhaust gas at the top and bottom, and the remaining surface is an open surface to allow the main flowing gas to pass, and the fluid mixing headers provided on the flat tube support panels on both sides are combined to form a module. Each model The fluid mixing and transfer between the pipes are connected through the connection flow path of the header, and if necessary, additional modules are installed to match the size and heat exchange amount, narrowing the gap between the flat pipes and reducing the density of the flat pipes. It features a structure in which modules are arranged and connected so as to be enhanced.

Hereinafter, the present invention will be described in detail. The flat tube-group module type condensing heat exchanger of the present invention can significantly reduce the size of the dead zone of the flow and greatly reduce the pressure loss as compared with the existing shell-tube heat exchanger. The heat exchange efficiency is improved by the high heat transfer coefficient near the stagnation point of the gas jet, so that the heat exchange efficiency can be improved, the compactness can be achieved, and the module structure can easily cope with the increase and decrease of the heat exchange capacity.

Further, the heat transfer efficiency in the curved tube portion is improved as compared with the case of using the existing U-shaped tube, so that the manufacture is easy.
The mean temperature difference between the heat transfer media can be increased by mixing the liquid inside the tubes at the intermediate header. Therefore, the heat exchanger of the present invention is a heat exchanger having higher efficiency than the existing shell-tube heat exchanger and U-shaped tube-group heat exchanger.

In addition, the density of the flow direction and the inclination angle can be easily changed in design, and the design flexibility can be increased.
On the other hand, if the outer surface shape of the tube is required,
The heat transfer enhancement effect is much higher than that of a simple flat tube by processing it into various forms such as fins, hexahedral projections, or convex or concave, and fine wavy shapes. Is obtained.

When the heat exchanger is manufactured, the main body is modularized to form a connecting flow path, so that the capacity can be adjusted as required and the structure can be easily disassembled and cleaned. Also, by mixing the flows of the respective pipes in the header, the temperature distribution becomes almost uniform, and in the U- or V-type condensate flowing grooves, the discharge of the condensate outside the pipes is facilitated, so that heat transfer is achieved. Enables the mounting of corrosion resistant metal or plastic (or Teflon (TM)) spacers, beams or cross rod supports between tube bundles to not only increase the modulus but also prevent flow induced vibrations .

In general, in the case of a gas-liquid heat exchanger, the heat resistance on the liquid side is very small, and the heat transfer on the liquid side is relatively reduced in consideration of the heat resistance on the gas side to increase the pressure. The ability to adjust the aspect ratio to achieve some balance is another advantage of flat tubes. Further, there is an advantage that a tube having a helically twisted structure can be used to promote heat transfer while reducing the pressure loss and facilitate the removal of condensed water.

A flat tube having a large aspect ratio can be manufactured by bending a strip of a plate having various uneven patterns to promote heat transfer and seam welding.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings. FIG. 1 is an overall assembly plan view of the apparatus of the present invention.
Is a plan view of the whole assembly using a header of another form according to the apparatus of the present invention, and a plurality of flat tubes 11 for fluid supply, flat tube support panels 16 for supporting both side surfaces of the flat tubes 11 for fluid supply, and An exhaust gas blocking panel 17 for fixing the supporting panel 16 at the upper and lower portions and a fluid mixing header 13 provided on the flat tube supporting panel 16 on both sides are connected in series to form a module to mix and move the fluid between the modules. Indicates that the connection flow path of the header is connected to the connection device 14 to move the fluid, and the plurality of flat tubes 11 for supplying fluid are connected to the plurality of support bases 12 which play a role of suppressing flow-induced vibration. Fixedly supported.

FIG. 1B, which is a side view of the "A" portion of FIG. 1A, shows that the connecting device 14 bypasses the outside and connects the fluid mixing headers 13 of each module. In FIG. 2, not only the fluid-mixed type header 13 of FIG. 1 but also the series connection, each module is connected by using an integrated fluid mixing and connection header 15 without a separate fluid connection connection device. Configured.

FIG. 2B is an enlarged cross-sectional view taken along line BB of FIG. 2A, and FIG. 2C is an enlarged cross-sectional view taken along line CC of FIG. 2B. Has an "I" shape with a "U" shaped flow groove 12a serving as a drain for condensate, and a "V" shaped flow having a cross section for the support base 12 serving as a drain for condensate. It shows that it is an "X" shape having a groove 12a.

FIG. 3 (A) shows the flow of a flow path in which a fluid mixing type header 13 is connected to a connecting device 14 and each module is connected in series as a flow path of a modularized liquid supply pipe of the present invention. FIG. 3 (B) shows a flow in which the modules are connected in series as a flow path of a modularized liquid supply pipe according to the present invention, which is connected to a fluid mixing and connection / combination header 15 integrated without a connection device 14. The flow of the road is shown.

FIG. 4 shows a heat transfer tube bank (he) used in the present invention.
FIG. 3 is a perspective view of the transfer tube and header, showing a number of flat tubes 11 for supplying fluid, flat panel supporting panels 16 for supporting both sides of the flat tubes 11 for fluid supply, and upper and lower panels 16 for supporting the flat tubes. The exhaust gas cut-off panel 17 fixed by the above and the fluid mixing headers 13 provided on the flat tube supporting panels 16 on both sides are connected in series to form a module, and the fluid mixing and movement between each module connects the connection flow path of the header. Indicate that it is connected to the device 14 and configured to move fluid, and that it is configured to have an open surface to allow passage of the main flowing gas.

At this time, the flat tubes 11 serve as collision surfaces to increase the heat transfer coefficient at the collision surfaces due to the collision jets. After being arranged, the heat is collided with the flat tubes and the heat is arranged alternately left and right downstream of the flat tubes so that turbulence intensity is high due to the generation of recirculation vortices, flow mixing is large, and flow residence time is long.

FIG. 5 is a perspective view of the module type electric heating tube group used in the present invention at the time of parallel connection, in which the fluids flowing out of the modules connected in parallel are mixed to move the fluid through one flow path. The mixing header 18 is shown,
It shows that the flow of the main flowing gas flows horizontally with respect to the flat tube.

FIG. 6A is a side view of the flat tube for heat transfer used in the present invention, and FIG. 6B shows an external gas flow pattern of the flat tube for heat transfer used in the present invention. Angle of inclination β of a flat tube perpendicular to the flowing gas (0 ° ≦ β ≦ 90
°) and the amount of eccentricity δ. The amount of eccentricity δ is the gas flow velocity outside the flat tube and the collision inclination angle β, s, l of the flat tube.
To maximize the heat transfer coefficient.

Where s is the distance between the centers of the flat tubes in the direction perpendicular to the flow, and l is the distance between the centers of the flat tubes in the direction of flow. FIG. 7A is a side view of the flat tube for heat transfer used in the present invention, and FIG. 7B shows an external gas flow pattern of the flat tube for heat transfer used in the present invention. On the other hand, the collision inclination angle β of the flat tube that is horizontal (0 ° ≦ β ≦ 90
°) and the amount of eccentricity δ.

The amount of eccentricity δ is adjusted so as to maximize the heat transfer coefficient by the gas flow velocity outside the flat tube and the collision inclination angles β, s, l of the flat tube. Here, s is the distance between the centers of the flat tubes in the direction perpendicular to the flow, and l is the distance between the centers of the flat tubes in the flow direction. 8A is an assembly view of the multi-channel flat tube used in the present invention and the mixing promoter, FIG. 8B is a multi-channel flat tube used in the present invention, and FIG. 8C is used in the present invention. Shows a multi-channel flat tube in which a mixing promoter for promoting internal mixing of a fluid is inserted and divided by a large number of mixing promoter support walls 11a having a flat tube 11 formed therein. .

The mixing promoting body for promoting the internal mixing of the fluid promotes the mixing on the liquid side by the helical twisted tape 11b, thereby relatively reducing the thermal resistance. FIG. 9 (A) is a flat tube having an external condensation heat transfer promoting shape used in the present invention;
FIG. 9B shows a flat tube having an external condensation heat transfer promoting shape used in the present invention. The surface of the flat tube 11 is processed into a heat transfer promoting surface form to promote the condensation heat transfer.

FIG. 9A shows the heat transfer promoting surface in a low fin shape, and FIG. 9B shows the heat transfer promoting surface in a hexahedron shape. FIG. 10 (A) shows a twisted flat tube used in the present invention and an assembly drawing, and FIG. 10 (B) shows a DD of FIG. 10 (A).
In the cross-sectional view of the line, the flat tube 11 is provided with an end adjustment flat at one end to facilitate heat transfer by vortex motion while considerably reducing pressure loss and to facilitate removal of condensed water on the outer surface of the tube. A plurality of spiral torsion flat tubes 19 having a portion 19a are arranged and arranged vertically to the main flowing gas.

FIG. 11A shows the distortion (d) used in the present invention.
FIG. 11 shows a flat tube and an assembly drawing.
(B) shows a cross-sectional view taken along the line CC of FIG. 11 (A). The flat tube 11 promotes heat transfer by vortex while considerably reducing the pressure loss, thereby facilitating removal of condensed water on the outer surface of the tube. This shows that a large number of flat tubes 19 whose side portions are distorted are arranged vertically to the main flowing gas.

FIG. 12 (A) shows a corrugated flat tube used in the present invention and an assembly drawing, and FIG. 12 (B) is a cross-sectional view taken along line CC of FIG. 12 (A). In order to facilitate heat transfer by vortex while considerably reducing pressure loss and to facilitate removal of condensed water on the outer surface of the tube, a flat tube 19 having a corrugated side surface is used.
Shows a large number of devices arranged and arranged perpendicular to the main flowing gas.

FIG. 13 shows a flat tube having a large aspect ratio used in the present invention, and FIGS. 14 (A) to 15 (C) are full plan views showing the surface treatment of the flat tube of FIG. The surface of the flat tube 11 is stripped on a plate with an arbitrary aspect ratio so as to increase the pressure and balance by relatively reducing the heat transfer on the liquid side in consideration of the thermal resistance on the gas side.
To form a convex or concave strip 20a,
This shows what was molded into various shapes such as a fine corrugated shape.

FIG. 16A shows a flat tube used in the present invention having a large aspect ratio and easy to remove condensate. FIG. 16B shows the flat tube of FIG. A plan view of the entire weld shown is shown, but a guide 20c for accelerating the collection and removal of condensate is formed below the plate to facilitate the removal of condensed water by gravity. Explanation code 20
b is a welding line.

[0030]

The heat exchanger for condensing residual heat recovery according to the present invention can have a capacity and a size arbitrarily adjusted by adding a module according to a heat exchange capacity, thereby promoting heat transfer and mixing by a vertical / inclined impinging jet. High efficiency can be achieved by effective condensate removal. By condensing and recovering the moisture contained in the exhaust gas, it is possible to recover not only the current heat but also the residual heat, which has a high thermal efficiency. Condensing boilers that use gas or city gas, and corrosion-resistant materials can be applied to low-temperature hot water generators, and evaporators for air conditioning systems,
It can also be used as a waste heat recovery heater pipe.

[Brief description of the drawings]

FIG. 1A is a plan view of an entire assembly showing an apparatus of the present invention, and FIG. 1B is a partial side view of “A” in FIG. 1A.

2A is an overall assembly plan view using a header according to another embodiment of the present invention, FIG. 2B is an enlarged cross-sectional view taken along the line BB of FIG. 2A, and FIG. FIG. 4 is an enlarged cross-sectional view taken along line C.

FIGS. 3A and 3B are flow paths of a modularized liquid supply pipe of the present invention.

FIG. 4 is a diagram showing a module electric heating tube group (mod) used in the present invention.
ullar heat transfer tube b
(an) and a perspective view of the header (including a general series connection).

FIG. 5 is a perspective view of a modular electric heating tube group used in the present invention when connected in parallel.

FIG. 6A is a side view of a flat tube for heat transfer used in the present invention, and FIG. 6B is an external gas flow pattern of the flat tube for heat transfer used in the present invention.

FIG. 7A is a side view of a flat tube for heat transfer used in the present invention, and FIG. 7B is an external gas flow pattern of the flat tube for heat transfer used in the present invention.

8 (A) is an assembly view of a multi-channel flat tube and a mixing promoter used in the present invention, (B) is a multi-channel flat tube used in the present invention, and (C) is a mixing promoter used in the present invention. Body.

FIGS. 9A and 9B are flat tubes having an external condensation heat transfer promoting shape used in the present invention.

FIG. 10A is a sectional view of a twisted flat tube used in the present invention and an assembly drawing, and FIG. 10B is a sectional view taken along the line DD of FIG.

FIG. 11A shows the distortion (disto) used in the present invention.
rted) Flat tube and assembly drawing, (B) is C-C of (A)
It is a line sectional view.

FIG. 12 (A) is a waveform (wavy) used in the present invention.
(B) is a cross-sectional view taken along the line CC of (A).

FIG. 13 shows an aspect ratio (aspect) used in the present invention.
The flat tube has a large ratio.

14A is a full welding plan view showing the surface processing of the flat tube of FIG. 13, and FIGS. 14B and 14C are full welding plan views showing another surface processing of the flat tube of FIG. is there.

15 (A) to (C) are full plan views of welding showing another surface processing of the flat tube of FIG. 13;

FIG. 16 (A) is a flat tube having a shape having a large aspect ratio and easy to remove condensate used in the present invention;
(B) is a full plan view of welding (FIG. 14 (B) to FIG. 15 (C)) showing the shape for easily removing the condensate shown in FIG. Is similarly applicable).

[Explanation of symbols]

11 Flat tube for fluid supply 11a Mixing promoting body support wall inside flat tube for fluid supply 11b Twisted tape for promoting internal mixing of fluid 11c Impact inclination angle β (0 ≦ β ≦ 90) against main flowing gas
°), flat tube having an eccentricity δ 12 I or X-shaped heat exchange tube support base 12a having a condensed water removal promoting function and a flow promoting vibration preventing function 12a A removed condensed water flow groove 13 A header for serial fluid mixing 14 Connection device for fluid mixing header 15 Combination header for fluid mixing and connection 16 Flat tube support panel 17 Exhaust gas cut-off panel 18 Parallel fluid mixing header 19 Fluid supply twisted flat tube 19a Flat end for twisted flat tube end adjustment 20 Flat tube with large aspect ratio 20a Strip of uneven plate for promoting heat transfer for manufacturing flat tube 20b Welding line 20c Guide for removing and collecting condensed water by gravity

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[Procedure amendment]

[Submission date] June 30, 2000 (2006.3.3)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

Continuing on the front page (72) Inventor Kim Hye-Bon South Korea, Sok Samcheong-dong Jongsol Apartment 1-902 (No address) (72) Inventor Yom Han-Gill Sok Wol-pyeong 3 Dong Fan-sil Apartment 110, Daejeon, Korea -1503 (No address) (72) Inventor Li-Jung-Hyun South Korea Incheon Yong-suk Yong-su 2 635 Address 1 Cha-apart 109-2201 (72) Inventor Li Jung-Sik Seoul South Korea Yan-Chong Shin Jong 1-Dong Mok Ton apartment 1024-1405 (No address) F-term (reference) 3L103 AA32 AA37 AA39 CC27 CC30 DD08 DD32 DD42

Claims (17)

[Claims] 1. A heat exchanger for recovering waste heat of low-temperature exhaust gas, wherein after the collision, the turbulent flow impinges on the flat tubes of the heat which are alternately arranged after the collision, and the turbulence intensity is high due to the generation of a recirculating vortex, whereby flow mixing is performed. The support bases 12 are arranged alternately so as to be large and have a long flow residence time, and serve to suppress flow-promoting vibration.
A number of flat tubes 11 for supplying fluid, which are fixed by the main flow gas and serve as collision surfaces of the main flowing gas, flat panel supporting panels 16 for supporting both side surfaces of the flat tubes 11 for supplying fluid, Exhaust gas cut-off panel 17 fixed at the lower part, and the remaining surface is made an open surface so that the main flowing gas can pass through,
The fluid mixing headers provided on the flat tube supporting panels 16 on both sides are combined and modularized, and fluid mixing and movement between the modules are connected and configured through the connection flow path of the header. Module type condensate for low-temperature exhaust gas waste heat recovery, characterized by a module with additional modules installed so that they fit together, and the modules are arranged and connected to narrow the gap between the flat tubes and increase the density of the flat tubes Heat exchanger. 2. The condensing heat exchanger according to claim 1, wherein the modules are arranged in series. 3. The condensing heat exchanger according to claim 1, wherein said modules are arranged in parallel. 4. The series-mixing header according to claim 1, wherein the series-mixing header is constituted by a series-fluid-mixing header configured to connect the headers with a coupling device to move the fluid when the series-connected headers are connected in series. 3. The modular condensing heat exchanger for low-temperature exhaust gas waste heat recovery according to any one of 2. 5. The header of claim 1, wherein the fluid-mixing type header comprises a header for combined fluid mixing and connection without a separate fluid connection connection device when connected in series. The condensing heat exchanger for recovering low-temperature exhaust gas waste heat according to any one of the preceding claims. 6. The parallel fluid mixing header according to claim 1, wherein the fluid mixing header comprises a parallel fluid mixing header configured to mix fluids from a plurality of modules and move the fluid through one flow path when connected in parallel. The modular condensing heat exchanger for recovering low-temperature exhaust gas waste heat according to any one of claims 1 and 3. 7. The low temperature exhaust gas waste according to claim 1, wherein the cross section of the support base is an “I” shape having a “U” flow groove serving as a drain for condensate. Modular condensing heat exchanger for heat recovery. 8. The low-temperature exhaust gas according to claim 1, wherein a cross section of the support base is an “X” shape having a “V” shape flow groove serving as a drain for condensate. Modular condensation heat exchanger for waste heat recovery. 9. The low temperature exhaust gas waste heat recovery system according to claim 1, wherein the flat tube has a collision angle β (0 ° ≦ β ≦ 90 °) with the main flowing gas. Modular condensation heat exchanger. 10. The flat tube 11 is a multi-channel flat tube in which a mixing promoting body for promoting internal mixing of fluid is inserted and divided by a plurality of mixing promoting body support walls 11a formed therein. The modular condensing heat exchanger according to claim 1, wherein the low-temperature exhaust gas waste heat is recovered. 11. The mixing promoting body for promoting internal mixing of the fluid is a warped tape 11b having a spiral pattern, which promotes mixing on the liquid side so that thermal resistance is relatively reduced. A modular condensing heat exchanger for low temperature exhaust gas waste heat recovery as described. 12. A flat end adjustment flat plate at one end to promote heat transfer by vortex motion while considerably reducing pressure loss in the flat tube 11, and to facilitate removal of condensed water on the outer surface of the tube. The modular condensing heat exchanger for low-temperature exhaust gas waste heat recovery according to claim 1, characterized in that it is a spiral torsion flat tube (19) having a portion (19a). 13. The condensing heat exchanger according to claim 1, wherein the surface of the flat tube is processed into a heat transfer promoting surface form to promote condensing heat transfer. . 14. The heat transfer promoting surface is formed of a low fin (l).
14. An fin (ow fin) shape.
A modular condensing heat exchanger for low temperature exhaust gas waste heat recovery as described. 15. The condensing heat exchanger of claim 13, wherein the heat transfer promoting surface has a hexahedral shape. 16. A strip 20a is formed on the plate with an arbitrary aspect ratio so that the surface of the flat tube 11 is relatively reduced in heat transfer on the liquid side in consideration of thermal resistance on the gas side to increase pressure and balance. 2. The module type condensing heat exchanger according to claim 1, wherein the shape of the strip 20a is formed into various shapes such as a convex or concave shape and a fine corrugated shape. 17. The module for recovering waste heat of low-temperature exhaust gas according to claim 16, wherein a guide 20c for accelerating collection and removal of condensed liquid is formed at a lower portion of said plate to facilitate removal of condensed water by gravity. Type condensation heat exchanger.