A pure countercurrent open heat exchanger with equal flow path

Abstract

The present invention relates to the field of heat exchangers, and in particular to an equal-flow-path pure countercurrent open heat exchanger, the heat exchanger comprising a barrel-shaped shell, within which N annular heat exchange plates are coaxially arranged, the flow path of each heat exchange plate increasing arithmetically from the inside to the outside; the inner cavity of the heat exchange plate constitutes a heat exchange medium flow channel, and sewage flow channels are formed between adjacent heat exchange plates; separation welds are horizontally arranged on the heat exchange plates, which separate the heat exchange medium flow channels of the heat exchange plates into an upper heat exchange zone and a lower heat exchange zone with equal flow paths, both of which are provided with a heat exchange medium inlet joint and a heat exchange medium outlet joint; the heat exchange medium outlet joint of the upper heat exchange zone in the i-th circle of heat exchange plates is connected to the heat exchange medium inlet joint of the lower heat exchange zone in the (N+1-i)th circle of heat exchange plates through a distribution pipe, so as to form N groups of heat exchange medium channels with the same flow path. The present invention ensures uniform heat exchange between the inner and outer heat exchange plates, which are distributed in concentric circles. The media in each heat exchange plate circle can form an equal flow path from the inside to the outside, thereby fully utilizing the heat of the clean working medium and improving the heat exchange efficiency.

Description

Technical Field

[0001] The invention relates to the field of heat exchangers, in particular to an equal flow path pure countercurrent open heat exchanger. Background Art

[0002] With the rapid development of heat exchanger technology, non-clean working fluid heat exchangers have been developed for special scenarios such as crude oil chemical industry, textile, industrial wastewater containing solid particles, sewage / mud containing biomass, and other non-clean working fluids. The current traditional heat exchanger, as described in the publication number "CN106403397A", ​​includes an air inlet manifold, a liquid outlet manifold, and a plurality of heat exchange tubes connected between the air inlet manifold and the liquid outlet manifold. The multiple heat exchange tubes are arc-shaped and arranged at intervals in the radial direction. This type of annular heat exchange tube and plate structure forms a heat exchange medium flow channel in the tube body or plate body for the flow of clean working fluid, and a non-clean working fluid flow channel is formed between adjacent heat exchange tubes.

[0003] Since the heat exchange tubes of traditional heat exchangers are designed in concentric circles, the flow path lengths of the clean working fluid in each circle are inconsistent and the fluid is unevenly distributed. During the heat exchange process, the clean working fluid in the inner circle heat exchange tubes is discharged from the heat exchanger before it is fully heat exchanged, while the clean working fluid in the outer circle heat exchange tubes has completed heat exchange with the unclean working fluid before being discharged from the heat exchanger. As a result, the clean working fluid in the second half of the outer circle heat exchange tubes cannot achieve any heat exchange effect at all, and the heat of the clean working fluid cannot be fully utilized. Therefore, it is urgent to solve this problem. Summary of the Invention

[0004] To avoid and overcome the technical problems of the prior art, the present invention provides an equal-flow-path pure countercurrent open heat exchanger. This invention ensures uniform heat transfer between the concentrically arranged inner and outer heat exchange plates. From the inner to the outer rings, the medium in each heat exchange plate circle forms an equal-flow-path flow, fully utilizing the heat of the clean working fluid and improving heat exchange efficiency.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A pure countercurrent open heat exchanger with equal flow path comprises a barrel-shaped shell with N annular heat exchange plates coaxially arranged inside the shell, the flow path of each heat exchange plate increasing arithmetically from the inside to the outside; the inner cavity of the heat exchange plate constitutes a heat exchange medium flow channel, and the space between adjacent heat exchange plates constitutes a sewage flow channel; separation welds are horizontally arranged on the heat exchange plates, and the separation welds separate the heat exchange medium flow channel of the heat exchange plate into an upper heat exchange zone and a lower heat exchange zone with equal flow paths, and both the upper heat exchange zone and the lower heat exchange zone are provided with a heat exchange medium inlet joint and a heat exchange medium outlet joint; the heat exchange medium outlet joint of the upper heat exchange zone in the i-th circle of heat exchange plates is connected to the heat exchange medium inlet joint of the lower heat exchange zone in the (N+1-i)th circle of heat exchange plates through a distribution pipe, so as to form N groups of heat exchange medium channels with the same flow path.

[0007] As a further solution of the present invention: the heat exchange medium inlet joints and the heat exchange medium outlet joints of the upper heat exchange zone and the lower heat exchange zone are both arranged at the bottom of the heat exchange plate, and the two ends of the separating weld line extend vertically downward to form a guide weld line. The separating weld line and the guide weld line cooperate to form a U-shaped weld line with an opening downward. The heat exchange plate is bounded by the U-shaped weld line, the inner side of the U-shaped weld line constitutes the lower heat exchange zone, and the outer side of the U-shaped weld line constitutes the upper heat exchange zone; the heat exchange medium inlet joints of the upper heat exchange zone and the lower heat exchange zone are symmetrically arranged on both sides of one of the guide weld lines, and the heat exchange medium outlet joints of the upper heat exchange zone and the lower heat exchange zone are symmetrically arranged on both sides of the other guide weld line; diversion weld lines are arranged at intervals along the vertical direction in the upper heat exchange zone and the lower heat exchange zone, and the diversion weld lines correspond to the vertical positions of each heat exchange medium inlet joint and the heat exchange medium outlet joint.

[0008] As a further solution of the present invention: the heat exchange plate is formed by bending a flat plate and then welding it to form an annular plate. The heat exchange plate includes two groups of plates with their edges welded and fixed. The plate bodies of the two plates are welded and fixed by evenly arranged welding points. The plate cavity of the heat exchange plate is pressurized and expanded to form multiple groups of heat exchange medium flow cavities. Each heat exchange medium flow cavity has four groups of welding points arranged in a diamond shape as boundary points. The opening of the heat exchange medium flow cavity is formed between two adjacent groups of welding points of the upper and lower plates. Each opening of the heat exchange medium flow cavity is connected to the adjacent heat exchange medium flow cavity.

[0009] As a further solution of the present invention: the welding points are circular welding points, and a spatial rectangular coordinate system is established with the center of the welding point as the origin. The plate arrangement direction of the heat exchange plate corresponds to the plane formed by the Z axis and the X axis in the spatial rectangular coordinate system. The spacing between two sets of welding points arranged at a distance from each other in the heat exchange medium flow cavity is 2S. T The distance between the other two sets of welding points arranged in close opposition in the heat exchange medium flow cavity is 2S L , the maximum bulging height of the heat exchange medium flow cavity along the Y axis is δ; then in the spatial rectangular coordinate system, the contour coordinates of the heat exchange medium flow cavity on the Y axis are:

[0010]

[0011] As a further solution of the present invention: a heat exchange medium inlet pipe and a heat exchange medium outlet pipe are provided on the shell. The heat exchange medium inlet pipe transports heat exchange medium to each upper heat exchange zone through the inlet branch pipe; the heat exchange medium outlet pipe receives the heat exchange medium discharged from each lower heat exchange zone through the outlet branch pipe. The heat exchange medium inlet pipe, the heat exchange medium outlet pipe and the distribution pipe are all arranged in the tube bundle area of ​​the shell.

[0012] As a further solution of the present invention: the width of the weld line at the top edge of each heat exchange plate located in the inner circle is ≤2cm, the width of the weld line at the bottom of each heat exchange plate located in the inner circle is ≥6cm, and equalizing holes are evenly opened circumferentially along the weld line at the bottom to connect the sewage flow channels on both sides of the heat exchange plate, and the aperture of each equalizing hole is ≥3cm.

[0013] As a further solution of the present invention: an exhaust hole is provided on the top of the upper heat exchange zone, and a ventilation hole is opened on the dividing weld line to allow the gas in the lower heat exchange zone to enter the upper heat exchange zone; an overflow port for sewage to pass through is provided on the top of each heat exchange plate, and each overflow port corresponds to the height of the sewage outlet pipe on the shell. An arc-shaped outlet is opened on the heat exchange plate located on the outermost circle, and the arc radius corresponds to the radius of the sewage outlet pipe so as to directly connect to the sewage outlet pipe.

[0014] As a further solution of the present invention: a sewage pipe box connected to the sewage inlet pipe is provided at the bottom of the shell, and distribution holes corresponding to the positions of each sewage flow channel are opened on the sewage pipe box, and each distribution hole provides sewage to each sewage flow channel from bottom to top; a sewage outlet for discharging sewage to the outside is provided at the bottom of the shell, and a sewage discharge joint is opened on the sewage pipe box outside the shell.

[0015] As a further solution of the present invention: the opening at the top of the shell is closed by a cover, one end of which is hingedly engaged with the shell to flip over and close the shell opening; a drive shaft is axially arranged in the shell, and the drive shaft is driven to rotate by a drive motor, and the drive motor is detachably fixed to the cover through a motor base.

[0016] As a further solution of the present invention: a cleaning rod arranged radially along the shell is fixed on the driving shaft, and an installation gap is provided between the cover and the heat exchange plate for the rotation of the cleaning rod. Brushes arranged vertically are arranged at intervals on the cleaning rod, and the brush surface of the brush contacts the plate surface of the corresponding heat exchange plate.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The equal flow path design of the heat exchange medium flow channels of the present invention ensures that the flow cross-sectional area and flow length of all heat exchange medium flow channels are exactly the same when the heat exchange medium passes through the interior of the heat exchanger, achieving uniform distribution of the heat exchange medium flow rate. The overall flow path is pure countercurrent, which fully utilizes the heat of the clean working fluid, improves the heat exchange efficiency, and avoids the influence of heat exchange caused by inconsistent flow paths of the inner and outer rings of the concentric circle design heat exchange tubes.

[0019] 2. The present invention implements an expansion design for the heat exchange plate and obtains the optimal expansion profile of the heat exchange plate through calculation to maximize its heat exchange efficiency. While reducing the volume of the heat exchanger, it can ensure that the heat exchanger has a high heat exchange efficiency and is not prone to blockage inside the heat exchanger.

[0020] 3. The non-clean working fluid of the present invention is distributed to the sewage flow channel between adjacent heat exchange plates through the distribution hole of the sewage pipe box, flows from bottom to top and converges through the overflow port before flowing out from the sewage outlet pipe. The flow path in the vertical direction is the same, forming a sewage flow path with equal flow path, ensuring uniform heat exchange.

[0021] 4. There are no pipeline obstacles between adjacent heat exchange plates in the present invention. The motor drives the cleaning rod to rotate, which causes the raw sewage to have a concentric rotational angular velocity in the horizontal direction. On the one hand, this rotation increases the flow rate of the sewage itself and increases turbulent disturbance. On the other hand, the soft bristles on the brush group directly physically contact the heat exchange surface of the heat exchange plate, removing dirt and biofilm deposits that may be generated by long-term operation. The outer side of the plate always remains in a "brand new" state. While physically removing the biofilm or dirt deposited on the surface, the wall thermal resistance on the sewage side is reduced to 0, maintaining the heat exchange performance of the heat exchanger and achieving the dual purposes of "preventive self-cleaning" and "enhanced turbulent heat exchange on the non-clean side." BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] Figure 2 It is a structural schematic diagram of the inner ring heat exchange plate after being flattened in the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of the outermost heat exchange plate after it is flattened out in the present invention.

[0025] Figure 4 This is a schematic diagram of the flow path connection of the heat exchange plate in the present invention.

[0026] Figure 5 It is a partial cross-sectional view of the heat exchange plate in the present invention.

[0027] In the picture:

[0028] 1. Shell; 11. Heat exchange medium inlet pipe; 12. Heat exchange medium outlet pipe;

[0029] 13. Distribution pipe; 14. Sewage inlet pipe;

[0030] 141. Sewage pipe box; 142. Distribution hole; 143. Sewage connection; 15. Sewage outlet pipe;

[0031] 2. Capping; 3. Driving motor; 4. Driving shaft;

[0032] 6. Heat exchange plate; 61. Plate; 62. Heat exchange medium flow cavity; 63. Welding point;

[0033] 64. Heat exchange medium inlet connector; 65. Heat exchange medium outlet connector;

[0034] 66. Overflow port; 67. Vent hole; 68. Separation welding line;

[0035] 681, guide welding line; 682, diversion welding line; 683, upper heat exchange area; 684, lower heat exchange area;

[0036] 69. Flow equalizing hole. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] See also Figures 1 to 5 In an embodiment of the present invention, a pure countercurrent open heat exchanger with equal flow path is provided, wherein the shell 1 of the heat exchanger is a barrel-shaped structure with an open top, and a cover 2 is installed at the bottom opening.

[0039] The cover 2 is hingedly connected to the housing 1 via a hinge structure, so that the opening of the housing 1 can be closed by flipping open and close. A handle structure is provided on the cover 2 to facilitate manual opening and closing of the cover 2. A motor base is installed on the crossbeam of the cover 2 to install the drive motor 3.

[0040] Multiple circles of heat exchange plates 6 are coaxially arranged within the housing 1. Each heat exchange plate 6 is horizontally defined by a separator weld line 68. The separator weld line 68 is shorter than the unfolded length of the heat exchange plate 6, and a gap exists between the ends of the separator weld line and the weld seams on either side of the heat exchange plate 6. Two parallel guide weld lines 681 extend vertically downward from each end of the separator weld line 68. These guide weld lines 681, along with the separator weld line 68, form a U-shaped weld line, dividing the heat exchange medium flow path within the heat exchange plate 6 into two heat exchange zones. The inner circle of the U-shaped weld line defines the lower heat exchange zone 684, while the outer circle defines the upper heat exchange zone 683. The heat exchange medium flow paths within the upper and lower heat exchange zones 683 and 684 are equal in diameter.

[0041] The heat exchange plate 6 is a hollow plate that is bent and then welded to form an annular plate. It comprises two sets of plates 61, secured by welding at their edges. The plates 61 are then secured together by evenly spaced weld points 63. Pressurization between the two sets of plates 61 creates a bulging, three-dimensional space between the weld points 63. Specifically, the plates 61 are formed by laminating two metal sheets and then laser or resistance welding. The inlet and outlet pipes are then connected, and the remaining edges of the plates are sealed again using laser or resistance welding. Finally, the plates are hydraulically bulged to form the final shape.

[0042] The weld points 63 are arranged in multiple rows on the vertical surface of the plate 61. The weld points 63 in each row are equally spaced, and the weld points 63 in adjacent rows are staggered vertically. The four groups of weld points 63 arranged in a diamond pattern form heat exchange medium flow cavities 62. Multiple groups of heat exchange medium flow cavities 62 are provided. Each of the non-edge heat exchange medium flow cavities 62 has four openings, each of which communicates with an adjacent opening in the heat exchange medium flow cavities 62, allowing the heat exchange medium to flow through the bulging three-dimensional space within the heat exchange plate 6. The weld points 63 are preferably annular.

[0043] A spatial rectangular coordinate system is established with the center of the welding point 63 as the origin. The arrangement direction of the heat exchange plate 6 corresponds to the plane formed between the Z axis and the X axis in the spatial rectangular coordinate system. The distance between two groups of welding points 63 arranged at a distance opposite to each other in the heat exchange medium flow cavity 62 is 2S. T The distance between the other two sets of welding points 63 arranged in close opposition in the heat exchange medium flow cavity 62 is 2S. L , the maximum bulging height of the heat exchange medium flow cavity 62 along the Y axis is δ; then in the spatial rectangular coordinate system, the contour coordinates of the heat exchange medium flow cavity 62 on the Y axis are:

[0044]

[0045] Annular sewage channels are formed between adjacent heat exchange plates 6, with each circle of channels interconnected. A drive motor 3 is mounted on the cover 2. This drive motor 3 controls the rotation of a drive shaft 4 via a reducer. The drive shaft 4 extends axially along the housing 1 and into the interior of the housing 1. A cleaning rod is secured to the drive shaft 4, its shaft extending along the diameter of the housing 1. Brushes are vertically mounted on the cleaning rods, corresponding to the height of the heat exchange plates. Two sets of brushes are preferably symmetrically arranged in each sewage channel. When the drive motor 3 rotates the cleaning rods via the drive shaft 4, the brush surfaces contact the heat exchange plates 6 on either side of the brushes, scrubbing and cleaning the plates.

[0046] A sewage pipe box 141 is provided at the bottom of the shell 1, and the sewage pipe box 141 is connected to the sewage inlet pipe 14. A plurality of distribution holes 142 are opened on the sewage pipe box 141. The number of distribution holes 142 corresponds to the number of sewage flow channels. The distribution holes 142 are preferably rectangular holes. A sewage pipe box 141 is also provided with a sewage discharge joint 143, which is used to independently discharge the silt in the sewage pipe box 141 after opening.

[0047] Each heat exchange plate 6 has an overflow port 66 at its top. The shape of the overflow port 66 is arbitrary. The connection of the sewage outlet pipe 15 corresponds to the height of the overflow port 66 of the heat exchange plate 6. Sewage flowing upward through the overflow port 66 is discharged along the sewage outlet pipe 15. The outer plates 61 of the outermost heat exchange plates 6 are 0.3-0.5 mm thicker than the inner plates. A set of arc-shaped outlets are formed on the top of the outermost heat exchange plates 6. The radius of the arc corresponds to the radius of the sewage outlet pipe 15, which connects to the sewage outlet pipe 15. A separate sewage outlet is provided at the bottom of the shell 1. During cleaning of the heat exchanger, dirt and impurities generated by cleaning are directly discharged through the sewage outlet. Compared to the sewage inlet pipe 14, the sewage outlet pipe 15 should be larger in size, and its top should be 2-5 cm lower than the total height of the heat exchange plates 6. The heat exchange medium inlet pipe 11 and the heat exchange medium outlet pipe 12 should preferably be arranged at a height higher than the sewage inlet pipe 14 and the sewage manifold 141.

[0048] When the heat exchange plates 6 are laid flat, each upper heat exchange zone 683 is provided with an exhaust hole 67 at the top. The exhaust holes 67 of the upper heat exchange zones 683 of each heat exchange plate 6 located in the inner circle (all heat exchange plates except the outermost circle heat exchange plate) are arranged vertically to avoid position interference with the brushing trajectory of the brush. Exhaust holes 67 are radially arranged at the top of the outer side surface of the heat exchange plate 6 located in the outermost circle. One section of the separating weld line 68 is disconnected, and a small-sized weld ring is provided at the disconnection point to form an air exchange hole, through which the gas in the lower heat exchange zone 684 is discharged into the upper heat exchange zone 683. The aperture of the air exchange hole is small, so the flow rate of the heat exchange medium exchanged between the lower heat exchange zone 684 and the upper heat exchange zone 683 through the air exchange hole is negligible. The position of the air exchange hole is preferably arranged 5 cm near the weld on the side of the heat exchange plate 6.

[0049] Except for the outermost heat exchange plate 6, the distance between the double-sided weld line at the top and the top edge of each heat exchange plate 6 in the inner circle is ≤2cm, and the distance between the double-sided weld line at the bottom and the bottom edge is ≥6cm. A large number of flow-balancing holes 69 with a diameter ≥3cm are evenly distributed along the double-sided weld line at the bottom in the circumferential direction at equal intervals, and the aperture of each flow-balancing hole 69 is ≥3cm.

[0050] The heat exchange medium inlet joints 64 of the upper and lower heat exchange sections 683 and 684 are symmetrically arranged on either side of one of the guide weld lines 681. The heat exchange medium outlet joints 65 of the upper and lower heat exchange sections 683 and 684 are symmetrically arranged on either side of the other guide weld line 681. Diverter weld lines 682 are vertically spaced apart within both sections 683 and 684, corresponding to the vertical positions of the heat exchange medium inlet joints 64 and outlet joints 65. The heat exchange medium in the upper and lower sections 683 and 684 is horizontally diverted by the diverter weld lines 682, flows along a circular path, and is discharged through the heat exchange medium outlet joint 65.

[0051] From the inside out, the heat exchange medium flow paths of each circle of heat exchange plates 6 increase in diameter. Two heat exchange zones in different circles are connected by a distribution pipe 13, forming a heat exchange medium channel. The distribution pipe 13 can be constructed in any form; in this embodiment, it is formed by multiple sections of 90-degree bends.

[0052] The number of heat exchange plates 6 arranged in circles is not limited. When there are N circles of heat exchange plates 6, the heat exchange medium outlet connector 65 of one group of heat exchange zones in the i-th circle of heat exchange plates 6 is connected to the heat exchange medium inlet connector 64 of one group of heat exchange zones in the (N+1-i)th circle of heat exchange plates 6 via the distribution pipe 13. The distribution pipes 13 are preferably arranged parallel to each other.

[0053] This embodiment uses nine circles of heat exchange plates 6 as an example. The two heat exchange zones in each circle of heat exchange plates 6 are zone A and zone B, where zone A represents the upper heat exchange zone 683 and zone B represents the lower heat exchange zone 684. The two heat exchange zones in each circle of heat exchange plates 6 are connected via nine sets of distribution pipes 13, thereby forming nine heat exchange medium channels with the same flow path. The specific connection method is as follows:

[0054] 1A-9B, 2A-8B, 3A-7B, 4A-6B, 5A-5B, 6A-4B, 7A-3B, 8A-2B, 9A-1B.

[0055] Among them, 1A-9B indicate that, from inside out, the upper heat exchange area 683 of the first circle of heat exchange plates 6 is connected to the lower heat exchange area 684 of the ninth circle of heat exchange plates 6 via a distribution pipe 13. The heat exchange medium inlet connector 64 of the upper heat exchange area 683 of the first circle of heat exchange plates 6 is connected to the heat exchange medium inlet pipe 11 on the shell 1 via an inlet branch pipe. The heat exchange medium outlet connector 65 of the upper heat exchange area 683 of the first circle of heat exchange plates 6 is connected to the heat exchange medium inlet connector 64 of the lower heat exchange area 684 of the ninth circle of heat exchange plates 6 via a distribution pipe 13. The heat exchange medium outlet connector 65 of the lower heat exchange area 684 of the ninth circle of heat exchange plates 6 is connected to the heat exchange medium outlet pipe 12 via an outlet branch pipe. The connections of the remaining pipelines correspond to the above connection method, and so on.

[0056] Based on this embodiment, the heat exchange plate 6 can be evenly divided into two groups of half zones, separated by a vertical weld. The two halves form a semi-annular structure with equal flow paths. Each half zone is also evenly divided into an upper heat exchange zone 683 and a lower heat exchange zone 684, with equal flow path heat exchange achieved through the distribution pipe 13. A further improvement can be to evenly divide the heat exchange plate 6 into multiple groups of zones along the vertical direction, each zone forming a heat exchange zone 683 and a lower heat exchange zone 684. This increases the number of heat exchange medium channels and the number of distribution pipes 13.

[0057] When the heat exchanger is started, first flip open the cover 2 and inject clean water as the heat exchange medium into the heat exchange area of ​​each heat exchange plate 6 through the heat exchange medium inlet pipe 11. The clean water flows through the heat exchange medium channels 1A-9B. At this time, the exhaust holes 67 on the two heat exchange areas 1A-9B are opened. After the air in the heat exchange medium channels 1A-9B is completely evacuated, the exhaust holes 67 on the two heat exchange areas 1A-9B are closed. Similarly, the air in each heat exchange medium channel is completely evacuated. Then, close the cover 2, open the sewage inlet pipe 14, and when the liquid level is flush with the inspection hole 21, activate the drive motor 3, rotating the sewage through the brush 51. This physical contact removes accumulated dirt from the surface of the heat exchanger 6, completing the start-up of the heat exchanger.

[0058] During operation, sewage outside the heat exchanger flows through distribution holes 142 in sewage manifold 141, into the various sewage channels within the heat exchanger, and freely flows through equalizing holes 69, thereby balancing the sewage level within the heat exchanger. When the brushes are rotated by drive motor 3, they impart a horizontal, concentric rotational velocity to the raw sewage. This rotation has two beneficial effects: firstly, it increases the fluid's velocity, creating more turbulent flow. Secondly, the soft bristles on the brush assembly directly physically contact the heat exchange surfaces of the heat exchange plates 6, removing dirt and biofilm deposits that may have accumulated over time, ensuring that the outer surfaces of the plates remain "fresh."

[0059] For drainage and maintenance, close the sewage outlet pipe 15, open the sewage outlet at the bottom of the heat exchanger, and open the sewage connection 143 on the sewage manifold 141. Under the action of gravity, the sewage flows out through the sewage outlet and connection 143. After the sewage is completely drained, open the cover 2 and flush downward with a high-pressure water gun to remove accumulated dirt from the openings of the distribution holes 142 of the sewage manifold 141. Alternatively, the sewage inlet pipe 14 and sewage manifold 141 can be directly cleaned with a high-pressure water gun. This allows dirt and impurities to be discharged directly from the sewage outlet.

[0060] Taking the Reynolds number as a variable, under the conditions of the same heat exchange medium, heat exchange velocity, and flow rate, a comparison of the convective heat transfer coefficients of the annular heat exchange plate formed by bending the existing rectangular hollow heat exchange plate and the heat exchange plate 6 of the present invention is shown in Table 1 below. It can be seen that when other operating conditions are the same, the heat exchange efficiency of the heat exchange plate of the present invention is much higher than that of the traditional rectangular hollow heat exchange plate.

[0061] Table 1

[0062]

[0063] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0064] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

Claims

1. A pure countercurrent open heat exchanger with equal flow path, characterized in that: The heat exchanger comprises a barrel-shaped shell (1), wherein N ring-shaped heat exchange plates (6) are coaxially arranged in the shell (1), and the flow path of each heat exchange plate (6) increases arithmetically from the inside to the outside; the inner cavity of the heat exchange plate (6) constitutes a heat exchange medium flow channel, and the space between adjacent heat exchange plates (6) constitutes a sewage flow channel; a separation weld line (68) is horizontally arranged on the heat exchange plate (6), and the separation weld line (68) divides the heat exchange medium flow channel of the heat exchange plate (6) into an upper heat exchange area (683) and a lower heat exchange area (683) with equal flow paths. The zone (684), the upper heat exchange zone (683) and the lower heat exchange zone (684) are all provided with a heat exchange medium inlet joint (64) and a heat exchange medium outlet joint (65); the heat exchange medium outlet joint (65) of the upper heat exchange zone (683) in the i-th circle of heat exchange plates (6) is connected to the heat exchange medium inlet joint (64) of the lower heat exchange zone (684) in the N+1-i-th circle of heat exchange plates (6) through a distribution pipe (13), so as to form N groups of heat exchange medium channels with the same flow path.

2. The equal flow path pure countercurrent open heat exchanger according to claim 1, characterized in that: The heat exchange medium inlet joint (64) and the heat exchange medium outlet joint (65) of the upper heat exchange zone (683) and the lower heat exchange zone (684) are both arranged at the bottom of the heat exchange plate (6). The two ends of the separation weld line (68) extend vertically downward to form a guide weld line (681). The separation weld line (68) and the guide weld line (681) cooperate to form a U-shaped weld line with an opening downward. The heat exchange plate (6) is bounded by the U-shaped weld line. The inner side of the U-shaped weld line constitutes the lower heat exchange zone (684), and the outer side of the U-shaped weld line constitutes the upper heat exchange zone (683); the upper heat exchange zone (683) The heat exchange medium inlet joint (64) of the lower heat exchange zone (684) is symmetrically arranged on both sides of one of the guide welding lines (681), and the heat exchange medium outlet joints (65) of the upper heat exchange zone (683) and the lower heat exchange zone (684) are symmetrically arranged on both sides of the other guide welding line (681); the upper heat exchange zone (683) and the lower heat exchange zone (684) are both provided with diverter welding lines (682) spaced apart in the vertical direction, and the diverter welding lines (682) correspond to the vertical positions of the heat exchange medium inlet joints (64) and the heat exchange medium outlet joints (65).

3. The equal flow path pure countercurrent open heat exchanger according to claim 1, characterized in that: The heat exchange plate (6) is formed by bending a flat plate and then welding it to form an annular plate. The heat exchange plate (6) includes two groups of plate sheets (61) with their edges welded and fixed. The plate bodies of the two plate sheets (61) are welded and fixed by evenly arranged welding points (63). The plate cavity of the heat exchange plate (6) is pressurized and expanded to form multiple groups of heat exchange medium flow cavities (62). Each heat exchange medium flow cavity (62) has four groups of welding points (63) arranged in a diamond shape as boundary points. An opening of the heat exchange medium flow cavity (62) is formed between two adjacent groups of welding points (63) of the upper and lower plate sheets (61). Each opening of the heat exchange medium flow cavity (62) is connected to an adjacent heat exchange medium flow cavity (62).

4. The equal flow path pure countercurrent open heat exchanger according to claim 3, characterized in that: The welding point (63) is a circular welding point. A spatial rectangular coordinate system is established with the center of the welding point (63) as the origin. The plate arrangement direction of the heat exchange plate (6) corresponds to the plane formed between the Z axis and the X axis in the spatial rectangular coordinate system. The distance between two groups of welding points (63) arranged at a distance opposite to each other in the heat exchange medium flow cavity (62) is 2S. T The distance between the other two groups of welding points (63) arranged in close opposition in the heat exchange medium flow cavity (62) is 2S. L , the maximum bulging height of the heat exchange medium flow cavity (62) along the Y axis is δ; then in the spatial rectangular coordinate system, the contour coordinates of the heat exchange medium flow cavity (62) on the Y axis are:

5. The equal flow path pure countercurrent open heat exchanger according to any one of claims 1 to 4, characterized in that: The shell (1) is provided with a heat exchange medium inlet pipe (11) and a heat exchange medium outlet pipe (12). The heat exchange medium inlet pipe (11) transports heat exchange medium to each upper heat exchange zone (683) through an inlet branch pipe; the heat exchange medium outlet pipe (12) receives heat exchange medium discharged from each lower heat exchange zone (684) through an outlet branch pipe. The heat exchange medium inlet pipe (11), the heat exchange medium outlet pipe (12) and the distribution pipe (13) are all arranged in the tube bundle area of ​​the shell (1).

6. The equal flow path pure countercurrent open heat exchanger according to any one of claims 1 to 4, characterized in that: The width of the weld line at the top edge of each heat exchange plate (6) located in the inner circle is ≤2 cm, and the width of the weld line at the bottom of each heat exchange plate (6) located in the inner circle is ≥6 cm, and equal flow holes (69) are evenly opened along the circumferential direction of the weld line at the bottom to connect the sewage flow channels on both sides of the heat exchange plate (6), and the aperture of each equal flow hole (69) is ≥3 cm.

7. The equal flow path pure countercurrent open heat exchanger according to any one of claims 2 to 4, characterized in that: An exhaust hole (67) is provided on the top of the upper heat exchange zone (683), and an air exchange hole is provided on the separation weld line (68) to allow the gas in the lower heat exchange zone (684) to enter the upper heat exchange zone (683); an overflow port (66) for sewage to pass through is provided on the top of each heat exchange plate (6), and each overflow port (66) corresponds in height to the sewage outlet pipe (15) on the shell (1). An arc-shaped outlet is provided on the heat exchange plate (6) located on the outermost circle, and the arc radius corresponds to the radius of the sewage outlet pipe (15) so as to be directly connected to the sewage outlet pipe (15).

8. The equal flow path pure countercurrent open heat exchanger according to any one of claims 1 to 4, characterized in that: A sewage pipe box (141) connected to the sewage inlet pipe (14) is provided at the bottom of the housing (1), and distribution holes (142) corresponding to the positions of the sewage flow channels are provided on the sewage pipe box (141), and each distribution hole (142) provides sewage to each sewage flow channel from bottom to top; a sewage outlet for discharging sewage to the outside is provided at the bottom of the housing (1), and a sewage discharge joint (143) is provided on the sewage pipe box (141) outside the housing (1).

9. The equal flow path pure countercurrent open heat exchanger according to any one of claims 1 to 4, characterized in that: The opening at the top of the shell (1) is closed by a cover (2), one end of which is hingedly connected to the shell (1) so as to flip over and cover the opening of the shell (1); a drive shaft (4) is axially arranged in the shell (1), and the drive shaft (4) is driven to rotate by a drive motor (3), and the drive motor (3) is detachably fixed to the cover (2) via a motor base.

10. The equal flow path pure countercurrent open heat exchanger according to claim 9, characterized in that: A cleaning rod is fixed on the driving shaft (4) and is arranged radially along the shell (1). There is an installation gap between the cover (2) and the heat exchange plate for the cleaning rod to rotate. Vertically arranged brushes are arranged at intervals on the cleaning rod, and the brush surface of the brush contacts the plate surface of the corresponding heat exchange plate.

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