Heat exchanger

Abstract

The present application provides a heat exchanger, comprising: a frame; a core plate bundle disposed within the frame, including a plurality of stacked heat exchange plates, with heat exchange channels formed between adjacent heat exchange plates, and at least one heat exchange process being formed by the heat exchange channels in the core plate bundle; a header assembly disposed outside the core plate bundle and communicating with the ports of the heat exchange channels; a grid plate assembly disposed within the header assembly and located at the port inlet of the heat exchange process, including at least two grid plates spaced apart along the extending direction of the heat exchange process, each grid plate including a plurality of plate pieces stacked at intervals, the stacking directions of the plate pieces of adjacent two grid plates being staggered, and the stacking direction of the plate pieces of the grid plate closer to the port inlet of the heat exchange process being perpendicular to the stacking direction of the heat exchange plates of the core plate bundle. The heat exchanger provided by the present application has a simple structure, is easy to manufacture, has a good fluid distribution effect, greatly improves the phenomena of abrasion and blockage, and has a long service life.

Description

Technical Field

[0001] This application relates to the technical field of heat exchange, and particularly to a heat exchanger. Background Art

[0002] A heat exchanger is a device that transfers part of the heat of a hot fluid to a cold fluid. Heat exchangers play an important role in many industrial productions such as chemical industry, petroleum, power, food, etc. In the field of alumina application, during the intermediate cooling production process of supersaturated alumina solution, a large number of high-hardness alumina particles agglomerate, decompose and crystal grains grow continuously during the temperature reduction process, resulting in phenomena such as abrasion, fouling and blockage failure of the heat exchanger applied in this process. For single-pass or multi-pass heat exchangers, at the inlet of each process flow, uneven flow and a large range of flow velocity changes are inevitable. Especially at the inlets after the second process flow, the problems of abrasion and blockage are more serious. Therefore, there is an urgent need for a heat exchanger that can improve the abrasion phenomenon. Summary of the Invention

[0003] In view of this, the purpose of this application is to propose a heat exchanger to solve the related problems mentioned in the background art.

[0004] Based on the above purpose, this application provides a heat exchanger, including: a frame; a core plate bundle disposed within the frame, including a plurality of stacked heat exchange plates, with heat exchange channels formed between adjacent heat exchange plates, and at least one heat exchange process being formed by the heat exchange channels in the core plate bundle; a header assembly disposed outside the core plate bundle and communicating with the ports of the heat exchange channels; a grid plate assembly disposed within the header assembly and located at the inlet of the port of the heat exchange process, including at least two grid plates spaced apart along the extending direction of the heat exchange process, each grid plate including a plurality of plate pieces stacked at intervals, and the stacking directions of the plate pieces of adjacent two grid plates being staggered; in the grid plate assembly, the grid plate close to the inlet of the port of the heat exchange process is the first grid plate, and the remaining grid plates are the second grid plates, and the stacking direction of the plate pieces of the first grid plate is perpendicular to the stacking direction of the heat exchange plates of the core plate bundle.

[0005] Further, the thickness of the plate piece is 6 mm to 15 mm, the spacing between the plate pieces is 0.3 times to 2.0 times the spacing of the heat exchange channels, and the length of the plate piece along the extending direction of the heat exchange process is 50 mm to 200 mm.

[0006] Furthermore, the heat exchange flow path includes a cold-side flow path and a hot-side flow path. The hot-side flow path forms at least one pass of hot-side process flow in the core plate bundle. The header assembly includes a cold-side header and a hot-side header. The grid plate assembly is disposed in the hot-side header and located at the port inlet of each pass of the hot-side process flow.

[0007] Furthermore, the plate spacing of the first grid plate is greater than or equal to the plate spacing of the second grid plate. The distance between the first grid plate and the core plate bundle is greater than or equal to the distance between the second grid plate and the first grid plate. Alternatively, the distance between the second grid plate and the first grid plate is equal to the distance between two adjacent second grid plates.

[0008] Furthermore, the distance between the first grid plate and the core plate bundle is 200 mm to 400 mm, and the distance between the second grid plate and the first grid plate is 100 mm to 200 mm.

[0009] Furthermore, the heat exchange flow path forms multiple passes of heat exchange process flow. Baffle plates are provided in the header assembly. Each group of grid plate assemblies includes a first grid plate and a second grid plate that are perpendicularly arranged to each other. At least one group of grid plate assemblies is disposed close to the baffle plate.

[0010] Furthermore, in the grid plate assembly close to the baffle plate, the plate spacing in at least part of the area close to the baffle plate is greater than the plate spacing in at least part of the area away from the baffle plate.

[0011] Furthermore, in the grid plate assembly close to the baffle plate, the second grid plate includes a first plate group and a second plate group that are stacked along the stacking direction of the heat exchange plates. The first plate group is disposed close to the baffle plate, and the plate spacing of the first plate group is greater than the plate spacing of the second plate group.

[0012] Furthermore, the plate spacing of the second plate group is greater than or equal to the spacing of the heat exchange flow path. The plate spacing of the first plate group is less than or equal to 1.5 times the plate spacing of the second plate group. The stacking thickness of the first plate group is 1 / 4 to 1 / 3 of the stacking thickness of the plates of the second grid plate.

[0013] Further, in the grid plate assembly near the baffle plate, the plate pitch of the first grid plate is greater than or equal to the plate pitch of the second plate group; or, in the grid plate assembly near the baffle plate, the first grid plate includes a third plate group and a fourth plate group stacked along the stacking direction of the heat exchange plates, a partition parallel to the baffle plate is provided between the third plate group and the fourth plate group, the third plate group is arranged close to the baffle plate, and the plate pitch of the third plate group is greater than the plate pitch of the fourth plate group.

[0014] As can be seen from the above, the heat exchanger provided by the present application includes: a frame; a core plate bundle arranged within the frame, including a plurality of stacked heat exchange plates, with heat exchange channels formed between adjacent heat exchange plates, and at least one pass of heat exchange process is formed by the heat exchange channels in the core plate bundle; a header assembly arranged outside the core plate bundle and communicating with the ports of the heat exchange channels; a grid plate assembly arranged within the header assembly and located at the port inlet of the heat exchange process, including at least two grid plates arranged at intervals along the extending direction of the heat exchange process, each grid plate including a plurality of plates stacked at intervals, and the stacking directions of the plates of adjacent two grid plates are arranged in a staggered manner; in the grid plate assembly, the grid plate close to the port inlet of the heat exchange process is the first grid plate, and the remaining grid plates are the second grid plates, and the stacking direction of the plates of the first grid plate is perpendicular to the stacking direction of the heat exchange plates of the core plate bundle. By providing staggered grid plates at the port inlet of the heat exchange process, the uneven distribution of high-solid-content fluid entering the core plate bundle of the heat exchanger can be solved, thereby improving the problems of abrasion, scaling, and blockage of the core plate bundle of the heat exchanger, and at the same time ensuring the high heat transfer performance during the operation of the heat exchanger, especially for the improvement of the fluid distribution at the port inlet of the heat exchange process after the second pass is more significant. Overall, the cleaning cycle of the heat exchanger can be extended, and the service life is improved. The heat exchanger has a simple structure, is easy to manufacture, has a good fluid distribution effect, greatly improves the abrasion and blockage phenomena, and has a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a three-dimensional structural schematic diagram of a heat exchanger in an embodiment of the present application;

[0017] Figure 2 is Figure 1 a cross-sectional structural schematic diagram of the heat exchanger;

[0018] Figure 3 Side view of the hot-side header located at the total hot-side inlet in the embodiment of the present application;

[0019] Figure 4 is Figure 3 Schematic cross-sectional structure diagram of the hot-side header along the A-A direction in

[0020] Figure 5 is Figure 3 Schematic cross-sectional structure diagram of the hot-side header along the B-B direction in

[0021] Figure 6 Side view of a hot-side header located at the baffle in the embodiment of the present application;

[0022] Figure 7 is Figure 6 Schematic cross-sectional structure diagram of the hot-side header along the C-C direction in

[0023] Figure 8 is Figure 6 Schematic cross-sectional structure diagram of the hot-side header along the D-D direction in

[0024] Figure 9 Side view of another hot-side header located at the baffle in the embodiment of the present application;

[0025] Figure 10 is Figure 9 Schematic cross-sectional structure diagram of the hot-side header along the E-E direction in

[0026] Figure 11 is Figure 9 Schematic cross-sectional structure diagram of the hot-side header along the F-F direction in

[0027] Reference numerals: 1, frame; 2, core plate bundle; 3, header assembly; 3-1, cold-side header; 3-2, hot-side header; 3-3, baffle; 3-4, diverter plate; 3-5, total hot-side inlet; 3-6, total hot-side outlet; 4, grid plate assembly; 4-1, first grid plate; 4-2, second grid plate; 4-3, first plate group; 4-4, second plate group; 4-5, third plate group; 4-6, fourth plate group; 4-7, partition board. Detailed implementation manners

[0028] To make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the ordinary meanings understood by those of ordinary skill in the art to which the present disclosure pertains. The "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative position relationships, and when the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0030] A heat exchanger is a device that transfers part of the heat of a hot fluid to a cold fluid. Heat exchangers play an important role in many industrial productions such as chemical engineering, petroleum, power, food, etc. In the field of alumina application, during the intermediate cooling production process of supersaturated alumina solution, a large number of high-hardness alumina particles agglomerate, decompose and crystal grains grow continuously during the temperature reduction process, resulting in phenomena such as abrasion, fouling and blockage failure of the heat exchangers used in this process. For single-pass or multi-pass heat exchangers, at the inlet of each process flow, uneven flow and a large range of flow velocity changes inevitably occur. Especially at the inlets after the second process flow, the abrasion and blockage problems are more serious. Therefore, there is an urgent need for a heat exchanger that can improve the abrasion phenomenon.

[0031] For a single-pass heat exchanger, at the inlet of the heat exchanger, affected by factors such as installation space limitations, pipeline elbow layouts, and filter blockages, uneven flow and a large range of flow velocity changes inevitably occur at the inlet of the heat exchanger. Excessive flow velocity will cause local abrasion at the inlet header and the inlet of the plate bundle of the heat exchanger. Uneven flow and low flow velocity will cause the decomposition of sodium aluminate and crystal grain growth in the fluid of the corresponding flow channel, thus causing blockage problems.

[0032] For a multi-pass heat exchanger, especially at the inlet of each pass after the second pass of the heat exchanger, due to the influence of the header size and fluid turning, the uneven flow phenomenon is more obvious: the flow rate in the flow channel close to the baffle is small, and scaling is likely to occur in the flow channel; the flow rate in the flow channel far from the baffle is large, and abrasion is likely to occur at its inlet part. In addition, uneven flow also affects the heat transfer efficiency of the heat exchanger, making the heat exchange amount of the fluid unable to meet the temperature reduction requirements designed for the decomposition tank.

[0033] In some technologies, a porous flow-distributing grid plate is proposed to be added at the total inlet on the hot side of the heat exchanger, which has a certain effect on improving the fluid distribution uniformity at the inlet of the first pass of the heat exchanger. However, for the multi-pass inlets after the second pass with more uneven flow distribution, no grid plate is considered for flow distribution. Moreover, the grid plate for single-pass distribution has limited effect on improving the fluid distribution uniformity in the flow channel, and the distribution method depends on the change of the orifice area at different positions of the grid plate. However, if the proportion of the orifice area is too small, it will significantly increase the fluid resistance, resulting in the consumption of pump power and being unfavorable for energy conservation. The small-hole jetting effect easily leads to a relatively high flow velocity behind the orifice, which is likely to cause local abrasion at the inlet of the liquid-solid two-phase heat exchanger in the wide-channel heat exchanger.

[0034] In some other technologies, an inner and outer two-stage opening and flow-guiding plate in a shape of an inverted V is arranged in the semi-circular head to solve the problem of uneven fluid distribution at the inlet of the shell-and-tube heat exchanger. The two-stage flow-guiding plate has an obvious effect of separating the passes at intervals, but there will still be a problem that the flow is concentrated between the flow-guiding plates, while in the peripheral area of the circular shell far from the inlet, the flow is significantly insufficient, the flow velocity is too low, and the improvement of the distribution uniformity is insufficient. Moreover, this orifice plate is not applicable to the liquid-solid two-phase medium working condition of the wide-channel heat exchanger, and its jetting effect will accelerate the local abrasion phenomenon at the inlet of the subsequent tube bundle.

[0035] It is necessary to consider solving the problem of the fluid distribution uniformity at the inlet of the heat exchanger, improving abrasion and slowing down fouling blockage problems, especially for the inlet area after the second pass of the multi-pass heat exchanger, improving the fluid distribution problem without requiring a larger shell space and higher manufacturing cost, and further improving the heat transfer performance of the heat exchanger, extending the product cleaning cycle and service life.

[0036] The following further details the technical solution of the present application through specific embodiments and in combination with the attached Figures 1 to 11 drawings.

[0037] In some embodiments of the present application, a heat exchanger is provided, such as Figure 1 and Figure 2As shown in the figure, it includes: a frame 1; a core plate bundle 2 disposed within the frame 1, including a plurality of stacked heat exchange plates, with heat exchange channels formed between adjacent heat exchange plates, and at least one heat exchange process being formed by the heat exchange channels within the core plate bundle 2; a header assembly 3 disposed outside the core plate bundle 2 and communicating with the ports of the heat exchange channels; a grid plate assembly 4 disposed within the header assembly 3 and located at the inlet of the port of the heat exchange process, including at least two grid plates spaced apart along the extension direction of the heat exchange process, each grid plate including a plurality of plates stacked at intervals, and the stacking directions of the plates of adjacent two grid plates being staggered; within the grid plate assembly 4, the grid plate close to the inlet of the port of the heat exchange process is the first grid plate 4-1, and the remaining grid plates are the second grid plates 4-2, and the stacking direction of the plates of the first grid plate 4-1 is perpendicular to the stacking direction of the heat exchange plates of the core plate bundle 2.

[0038] As Figure 1 shown in the figure, it is a schematic structural diagram of a heat exchanger, and the heat exchanger includes a frame 1, a core plate bundle 2, and a header assembly 3. The frame 1 is used to support the heat exchanger. The core plate bundle 2 is disposed within the frame 1 and is used for fluid heat exchange. The shape of the core plate bundle 2 is rectangular parallelepiped, including a plurality of stacked heat exchange plates. The direction H in the figure is the stacking direction of the heat exchange plates of the core plate bundle 2. Heat exchange channels are formed between adjacent heat exchange plates, and ports of the heat exchange channels are formed in the end regions of the heat exchange plates. The header assembly 3 is disposed outside the core plate bundle 2, and its shape is, for example, semi-cylindrical or rectangular parallelepiped, etc. The header assembly 3 communicates with the flow channel ports of the core plate bundle 2, providing space for fluid inlet / outlet and changing the fluid flow direction. The heat exchange channels form at least one heat exchange process within the core plate bundle 2. As Figure 2 shown in the figure, it is Figure 1 the cross-sectional view of the heat exchanger in [reference], and it can be seen that the heat exchange channels on the hot side have two heat exchange processes. The direction L in the figure is the extension direction of this heat exchange process and is also the length direction of the core plate bundle 2. When the heat exchange process is an odd number of processes, the hot side total inlet 3-5 and the hot side total outlet 3-6 are arranged corresponding to different header assemblies 3. When the heat exchange process is an even number of processes, the hot side total inlet 3-5 and the hot side total outlet 3-6 are arranged corresponding to the same header assembly 3.

[0039] A grid plate assembly 4 is provided inside the tube sheet assembly 3 and is located at the port inlet of the heat exchange process. The grid plate assembly 4 can select the specific installation position according to the distribution requirements. For example, it can be installed only at the port inlet after the second-pass heat exchange process, or only at the port inlet of the first-pass heat exchange process, or installed at the port inlet of each pass of the heat exchange process, etc. There is no specific limitation. Each group of grid plate assemblies 4 includes at least two grid plates arranged at intervals along the extension direction of the heat exchange process. The number of grid plates can be, for example, two, three, or four, etc. There is no specific limitation and can be adjusted according to the distribution effect.

[0040] As Figure 2 shown, a group of grid plate assemblies 4 are installed at the port inlet of each pass of the heat exchange process. Each group of grid plate assemblies 4 includes two grid plates arranged at intervals along the extension direction of the heat exchange process. The grid plate in the grid plate assembly 4 close to the inlet of the heat exchange process is the first grid plate 4-1, and the remaining grid plates are the second grid plates 4-2. Each grid plate includes a plurality of plates stacked at intervals. As Figure 4 and Figure 5 shown, it is a schematic cross-sectional view of the grid plate assembly 4 at the first-pass inlet in different directions. The grid plate includes a plurality of plates stacked at equal intervals along a single direction. The plate surface of a single plate is arranged parallel to the extension direction of the heat exchange process. The fluid flowing along the plates of the grid plate can be redistributed in flow rate, making the distribution more uniform. Compared with the orifice plate design, on the one hand, because the plates occupy less channel space and have less flow resistance, the subsequent heat exchange effect can be ensured. On the other hand, when the fluid flows along the plates, no jet flow is formed, the flow velocity is more stable, and local abrasion is avoided.

[0041] The stacking directions of the plates of two adjacent grid plates are arranged staggeredly, that is, the included angle between the stacking directions of the plates of two adjacent grid plates is greater than 0° and less than or equal to 90°. For example, the included angle is 30°, 45°, 60°, or 90°, etc. There is no specific limitation, which can further improve the fluid distribution effect. As Figure 5 shown, the included angle between the stacking directions of the plates of the two grid plates is 90°. After the fluid enters from the inlet, it first passes through the second grid plate 4-2 for preliminary uniform distribution and is mixed once in the space between the two grid plates. Then, the distribution direction is changed, and it enters the first grid plate 4-1 to change the distribution direction and be redistributed, so that the distribution of the fluid is more uniform, avoiding the phenomenon of abrasion and blockage that still occurs when the fluid enters the core plate bundle 2 with uneven distribution and laminar flow after only one distribution.

[0042] The stacking direction of the plates of the first grid plate 4-1 in each group of grid plate assemblies 4 close to the port inlet of the heat exchange process is perpendicular to the stacking direction of the heat exchange plates of the core plate bundle 2. As Figure 2As shown, this can further improve the distribution effect. After the above-mentioned fluid is distributed by the first grid plate 4-1, secondary mixing is carried out in the space between the first grid plate 4-1 and the core plate bundle 2, and finally the distribution direction is changed again and it enters the core plate bundle 2. Through multiple distributions, mixings, changing directions and then redistributions, and then mixing and changing directions and redistributions again, the distribution of the fluid becomes more uniform, significantly reducing the distribution dead zone.

[0043] The grid plate assembly 4 includes at least two grid plates, ensuring that the grid plate assembly 4 performs at least two fluid distributions to ensure the fluid distribution effect. The more the number of grid plates in the grid plate assembly 4, the higher the final distribution effect. Generally, two grid plates can achieve a uniform distribution effect. However, the severity of the crossflow is different under different working conditions. For working conditions with severe crossflow, more staggered grid plates can be set to improve the fluid distribution effect. But as the number of grid plates increases, more space is occupied, a longer tube box assembly 3 needs to be set, the manufacturing cost is higher, and the resistance loss is greater, which is not conducive to energy conservation.

[0044] In addition, although the grid plate assembly 4 is arranged at the port inlet of each heat exchange process, it can improve the fluid distribution effect at the inlet of each heat exchange process. However, the first heat exchange process is connected to the overall inlet of the heat exchange flow path. As Figure 2 shown, there is usually a long straight pipe section at this place, so the fluid non-uniformity or crossflow is not obvious. And for the heat exchange processes after the second process, because the fluid will flow in a zigzag pattern and the flow direction changes, the crossflow is very obvious. That is to say, the grid plate assembly 4 has a better improvement effect on the fluid distribution at the port inlet of the heat exchange processes after the second process, which can avoid the erosion phenomenon at the inlet and improve the heat exchange effect. From the perspective of cost or occupied space, the grid plate assembly 4 can also be arranged only at the port inlet of the heat exchange processes after the second process.

[0045] By arranging staggered grid plates at the port inlet of the heat exchange process, the problem of uneven distribution of high-solid-content fluid entering the core plate bundle 2 of the heat exchanger can be solved, improving the problems of erosion, fouling and blockage of the core plate bundle 2 of the heat exchanger. At the same time, the high heat transfer performance during the operation of the heat exchanger is ensured. Especially for the port inlet fluid distribution of the heat exchange processes after the second process, the improvement is more significant, overall extending the cleaning cycle of the heat exchanger and increasing the service life.

[0046] This heat exchanger has a simple structure, is easy to manufacture, has a good fluid distribution effect, greatly improves the erosion and blockage phenomena, and has a long service life.

[0047] In some embodiments, as Figures 3 to 5As shown, the thickness of the plate is 6 mm to 15 mm, the spacing between the plates is 0.3 to 2.0 times the spacing of the heat exchange channels, and the length of the plate along the extension direction of the heat exchange process is 50 mm to 200 mm.

[0048] As Figure 4 shown, the thickness T of the plate is 6 mm to 15 mm, such as 6 mm, 8 mm, 10 mm, 12 mm or 15 mm, etc., and is not specifically limited, which can ensure the structural strength and heat exchange effect. Avoiding the plate being too thin, the grid plate has low strength, inconvenient assembly and welding, less wear-resistant thickness margin, short service life and short replacement cycle; also avoiding the plate being too thick, which occupies a large space for the channel, will significantly increase the fluid flow resistance, reduce the heat exchange effect, and also increase the manufacturing cost.

[0049] As Figure 2 shown, the spacing of the heat exchange channels is D0, and the spacing between the plates is set to (0.3 - 2.0)D0, such as the spacing being 0.3D0, 0.5D0, 1.0D0, 1.5D0 or 2.0D0, etc., and is not specifically limited, which can ensure the fluid distribution effect and heat exchange effect. Avoiding too small a spacing, the flow resistance is too large, the heat exchange effect is reduced, and at the same time the manufacturing cost is increased; also avoiding too large a spacing, the fluid distribution effect is poor, and impurities or large particle substances in the fluid will enter the core plate bundle 2, causing blockage, uneven flow and abrasion, etc., and it is difficult to repair.

[0050] In some embodiments, as Figure 2 shown, the heat exchange channels include a cold-side channel and a hot-side channel. The hot-side channel forms at least one pass of the hot-side process in the core plate bundle 2. The header assembly 3 includes a cold-side header 3-1 and a hot-side header 3-2. The grid plate assembly 4 is arranged in the hot-side header 3-2 at the port inlet of each pass of the hot-side process.

[0051] The heat exchange channels include a cold-side channel and a hot-side channel, which are arranged alternately. Correspondingly, the header assembly 3 includes a cold-side header 3-1 and a hot-side header 3-2. The hot-side channel forms at least one pass of the hot-side process in the core plate bundle 2. As Figure 2 shown, the hot-side channel forms two passes of the hot-side process in the core plate bundle 2. Because usually the fluid in the hot-side channel will cool and crystallize after heat exchange, and it is more likely to occur serious abrasion, fouling and blockage failure. Setting the grid plate assembly 4 in the hot-side header 3-2 at the port inlet of each pass of the hot-side process can more effectively ensure the heat exchange effect and improve the service life. And the fluid in the cold-side channel usually has fewer impurities, and the grid plate assembly 4 can not be set, reducing the manufacturing cost and occupying less space.

[0052] In some embodiments, as Figure 2As shown, the plate spacing of the first grid plate 4-1 is greater than or equal to the plate spacing of the second grid plate 4-2, the spacing between the first grid plate 4-1 and the core plate bundle 2 is greater than or equal to the spacing between the second grid plate 4-2 and the first grid plate 4-1, or the spacing between the second grid plate 4-2 and the first grid plate 4-1 is equal to the spacing between two adjacent second grid plates 4-2.

[0053] As Figure 4 shown, the plate spacing of the first grid plate 4-1 is D1. As Figure 5 shown, the plate spacing of the second grid plate 4-2 is D2. Set D1≥D2. For example, set D1≥D0 while D2≤D0. This can ensure the fluid distribution effect and improve the service life of the heat exchanger at the same time. The core plate bundle 2 is usually a thin plate structure. The heat exchange plates are prone to wear-through failure and are not easy to repair. The plate thickness of the grid plate is much greater than that of the heat exchange plate, with a large wear-resistant margin and is located in the header assembly 3, making it easy to repair and replace. When the hot-side fluid carries impurities or large particulate matter into the heat exchanger, it first passes through the second grid plate 4-2 with a smaller plate spacing, which can play a role in blocking and filtering impurities, avoiding impurities from entering the core plate bundle 2 and causing blockage, uneven flow, and abrasion. Then the fluid enters the first grid plate 4-1 with a larger spacing for fluid distribution. The fluid is evenly distributed with a small flow resistance and good heat exchange effect. Especially when a grid plate assembly 4 is set at the port inlet of the first-pass heat exchange process, the filtering effect is better.

[0054] As Figure 2 shown, the spacing between the first grid plate 4-1 at the first-pass inlet and the core plate bundle 2 is L1, the spacing between the first grid plate 4-1 at the second-pass inlet and the core plate bundle 2 is L3, the spacing between the first grid plate 4-1 at the first-pass inlet and the second grid plate 4-2 is L2, and the spacing between the first grid plate 4-1 at the second-pass inlet and the second grid plate 4-2 is L4. Set the spacing between the first grid plate 4-1 and the core plate bundle 2 to be greater than or equal to the spacing between the second grid plate 4-2 and the first grid plate 4-1, that is, set L1≥L2 and L3≥L4 to ensure that the fluid can be fully mixed and evenly distributed before entering the core plate bundle 2. L1 can be equal to or unequal to L3, and L2 can be equal to or unequal to L4, without specific limitation, and can be adjusted according to the fluid distribution degree at the actual position. In addition, for the case where there are multiple second grid plates 4-2 in a set of grid plate assemblies 4, the spacing between two adjacent second grid plates 4-2 can be equal to L2 or L4, which is convenient for design.

[0055] In some embodiments, the spacing between the first grid plate 4-1 and the core plate bundle 2 is 200 mm to 400 mm, and the spacing between the second grid plate 4-2 and the first grid plate 4-1 is 100 mm to 200 mm.

[0056] L1 is set to be from 200 mm to 400 mm. For example, L1 can be 200 mm, 300 mm, 400 mm, etc., and there is no specific limitation. This enables the fluid after secondary distribution to be mixed more effectively, avoiding the situation where L1 is too large, occupying a large space, and due to the influence of particle sedimentation in the fluid, etc., the fluid will again show uneven distribution; it also avoids the situation where L1 is too small, resulting in insufficient fluid mixing, excessive impact, abrasion or fouling blockage at the inlet of the core plate bundle 2.

[0057] L2 is set to be from 100 mm to 200 mm. For example, L2 can be 100 mm, 150 mm, 200 mm, etc., and there is no specific limitation. This enables the primary distribution fluid to be effectively mixed and redistributed.

[0058] In some embodiments, as Figures 3 to 5 shown, the heat exchange flow path forms a multi-pass heat exchange process. At least one baffle 3-3 is provided in the header assembly 3. A set of the grid plate assemblies 4 is provided at the port inlet of each heat exchange process after the second pass. The grid plate assembly 4 is arranged close to the baffle 3-3 and includes a first grid plate 4-1 and a second grid plate 4-2 which are perpendicularly arranged to each other.

[0059] As Figure 2 shown, the heat exchange flow path forms a two-pass heat exchange process. A baffle 3-3 is provided in the header assembly 3 at the inlet of the second pass, which is used to change the flow direction of the fluid, increase the number of flow paths of the fluid in the core plate bundle 2, increase the flow length, and improve the heat exchange effect. In addition, a diverter plate 3-4 is provided in the header assembly 3 at the inlet of the first pass, which is used to isolate the fluid in the first pass and the second pass.

[0060] The grid plate assembly 4 includes a first grid plate 4-1 and a second grid plate 4-2 which are perpendicularly arranged to each other. The perpendicularly arranged grid plates have the best fluid distribution effect. Setting two grid plates ensures the fluid distribution effect and can also ensure the space utilization rate. A set of the grid plate assemblies 4 is provided at the port inlet of each heat exchange process after the second pass. The grid plate assembly 4 is arranged close to the baffle 3-3, which can focus on improving the fluid distribution at the port inlet after the second pass and avoid abrasion and blockage phenomena.

[0061] In some embodiments, as Figures 6 to 8 shown, in the grid plate assembly 4 close to the baffle 3-3, the plate spacing in at least part of the area close to the baffle 3-3 is larger than the plate spacing in at least part of the area far from the baffle 3-3.

[0062] As Figure 8As shown, in the stagnant area near the baffle 3-3 where the fluid flow resistance is relatively large, plate sheets with a looser arrangement can be set; in the area far from the baffle 3-3 where the fluid flow resistance is relatively small, plate sheets with a relatively dense arrangement can be set, so that the overall fluid distribution is more uniform. For adjusting the spacing density of the plate sheets, the first grid plate 4-1 and the second grid plate 4-2 can be adjusted simultaneously, or only the second grid plate 4-2 can be adjusted, because the second grid plate 4-2 is closer to the position where the fluid flow direction changes and the fluid distribution is more uneven at this place.

[0063] In some embodiments, as Figures 6 to 8 shown, in the grid plate assembly 4 near the baffle 3-3, the second grid plate 4-2 includes a first plate sheet group 4-3 and a second plate sheet group 4-4 stacked along the stacking direction of the heat exchange plates. The first plate sheet group 4-3 is arranged close to the baffle 3-3, and the plate sheet spacing of the first plate sheet group 4-3 is greater than the plate sheet spacing of the second plate sheet group 4-4.

[0064] As Figure 8 shown, in the grid plate assembly 4 at the inlet after the second pass, the second grid plate 4-2 includes a first plate sheet group 4-3 and a second plate sheet group 4-4 stacked along the stacking direction of the heat exchange plates. The first plate sheet group 4-3 is arranged close to the baffle 3-3. The stacking direction of the plate sheets in the first plate sheet group 4-3 is the same as the stacking direction of the heat exchange plates, and the stacking direction of the plate sheets in the second plate sheet group 4-4 is also the same as the stacking direction of the heat exchange plates. The plate sheet spacing of the first plate sheet group 4-3 is D3-1, and the plate sheet spacing of the second plate sheet group 4-4 is D3-2. Set D3-1 > D3-2, so that the fluid in the stagnant area near the baffle 3-3 is subjected to less resistance, which is beneficial to uniform distribution.

[0065] In some embodiments, the plate sheet spacing of the second plate sheet group 4-4 is greater than or equal to the spacing of the heat exchange channels, the plate sheet spacing of the first plate sheet group 4-3 is less than or equal to 1.5 times the plate sheet spacing of the second plate sheet group 4-4, and the stacking thickness of the plate sheets in the first plate sheet group 4-3 is 1 / 4 to 1 / 3 of the stacking thickness of the plate sheets of the second grid plate 4-2.

[0066] Set D3-2 ≥ D0, because there are fewer impurities or large particle substances in the fluid flowing out of the core plate bundle 2, and the influence of impurity blockage can be ignored. The focus is on improving the influence of the resistance difference caused by the change of the flow direction. Set D3-2 < D3-1 ≤ 1.5D3-2 to ensure the improvement effect on the resistance difference in the stagnant area. As Figure 8 shown, the stacking thickness of the plate sheets in the first plate sheet group 4-3 is H1, and the overall stacking thickness of the plate sheets of the second grid plate 4-2 is H0. Set H1 = (1 / 4~1 / 3)H0 to ensure the uniform effect on the overall fluid resistance.

[0067] In some embodiments, as Figures 6 to 8 shown, in the grid plate assembly 4 near the baffle plate 3-3, the plate pitch of the first grid plate 4-1 is greater than or equal to the plate pitch of the second plate group 4-4; or, as Figures 9 to 11 shown, in the grid plate assembly 4 near the baffle plate 3-3, the first grid plate 4-1 includes a third plate group 4-5 and a fourth plate group 4-6 stacked along the heat exchange plate stacking direction, a partition plate 4-7 parallel to the baffle plate 3-3 is provided between the third plate group 4-5 and the fourth plate group 4-6, the third plate group 4-5 is arranged close to the baffle plate 3-3, and the plate pitch of the third plate group 4-5 is greater than the plate pitch of the fourth plate group 4-6.

[0068] On the basis of adjusting the pitch density of the plates of the second grid plate 4-2, since the first grid plate 4-1 is farther from the position where the fluid flow direction changes compared with the second grid plate 4-2, the pitch density of the plates of the first grid plate 4-1 may not be adjusted. As Figure 7 shown, the plate pitch of the first grid plate 4-1 is all D4, and D4≥D3-2 is set. The structure is simple, which can ensure the flow distribution effect and prevent the overall resistance of the fluid passing through the baffle plate 3-3 from increasing significantly.

[0069] In addition, the pitch density of the plates of the first grid plate 4-1 can also be adjusted. As Figure 10 and Figure 11 shown, the first grid plate 4-1 includes a third plate group 4-5 and a fourth plate group 4-6 stacked along the heat exchange plate stacking direction. A partition plate 4-7 parallel to the baffle plate 3-3 is provided between the third plate group 4-5 and the fourth plate group 4-6 for convenient fixation. The third plate group 4-5 is arranged close to the baffle plate 3-3. The plate stacking direction of the third plate group 4-5 is perpendicular to the heat exchange plate stacking direction, and the plate stacking direction of the fourth plate group 4-6 is also perpendicular to the heat exchange plate stacking direction. The plate pitch of the third plate group 4-5 is D4-1, and the plate pitch of the fourth plate group 4-6 is D4-2. D4-1>D4-2 is set, which also makes the fluid in the stagnant area near the baffle plate 3-3 subject to less resistance and is conducive to uniform distribution.

[0070] As Figure 11 shown, the plate length of the third plate group 4-5 along the stacking direction is H2, and H2≤H1 can be set to ensure the uniform effect of the overall resistance of the fluid. In addition, D4-1≥D3-1 and D4-2≥D3-2 can be set to ensure the flow distribution effect.

[0071] Those of ordinary skill in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; within the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as above, and for the sake of brevity, they are not provided in detail.

[0072] In addition, in the case where details are set forth to describe exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application can be implemented without these details or with variations of these details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0073] Although the present application has been described in connection with the embodiments of the present application, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description.

[0074] The embodiments of the present application are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. A heat exchanger, characterized in that: include: frame; A core plate bundle is arranged in the frame, and includes a plurality of stacked heat exchange plates, and heat exchange channels are formed between adjacent heat exchange plates, and the heat exchange channels form at least one heat exchange process in the core plate bundle; A pipe box assembly is arranged outside the core plate bundle and communicated with the port of the heat exchange flow channel; A grid plate assembly is arranged in the pipe box assembly, located at the port inlet of the heat exchange process, and includes at least two grid plates arranged at intervals along the extension direction of the heat exchange process, each of the grid plates includes a plurality of plates stacked and arranged at intervals, and the plate stacking directions of two adjacent grid plates are staggered; in the grid plate assembly, the grid plate close to the port inlet of the heat exchange process is the first grid plate, and the remaining grid plates are the second grid plates, and the plate stacking direction of the first grid plate is perpendicular to the heat exchange plate stacking direction of the core plate bundle.

2. The heat exchanger according to claim 1, characterized in that The thickness of the plate is 6 mm to 15 mm, the spacing between the plates is 0.3 times to 2.0 times the spacing between the heat exchange channels, and the length of the plate along the extension direction of the heat exchange flow path is 50 mm to 200 mm.

3. The heat exchanger according to claim 1, characterized in that The heat exchange flow channel includes a cold side flow channel and a hot side flow channel, the hot side flow channel forms at least one hot side process in the core plate bundle, the pipe box assembly includes a cold side pipe box and a hot side pipe box, and the grid plate assembly is arranged in the hot side pipe box and is located at the port inlet of each hot side process.

4. The heat exchanger according to claim 1, characterized in that The plate spacing of the first grid plate is greater than or equal to the plate spacing of the second grid plate, the spacing between the first grid plate and the core plate bundle is greater than or equal to the spacing between the second grid plate and the first grid plate, or the spacing between the second grid plate and the first grid plate is equal to the spacing between two adjacent second grid plates.

5. The heat exchanger according to claim 4, characterized in that The distance between the first grid plate and the core plate bundle is 200 mm to 400 mm, and the distance between the second grid plate and the first grid plate is 100 mm to 200 mm.

6. The heat exchanger according to claim 1, characterized in that The heat exchange flow channel forms a multi-pass heat exchange process, and at least one baffle is provided in the pipe box assembly. A group of grid plate assemblies are provided at the port inlet of each heat exchange process after the second pass. The grid plate assembly is arranged close to the baffle, and includes a first grid plate and a second grid plate arranged perpendicular to each other.

7. The heat exchanger according to claim 6, characterized in that In the grid plate assembly close to the baffle, the plate spacing in at least a portion of the region close to the baffle is greater than the plate spacing in at least a portion of the region away from the baffle.

8. The heat exchanger according to claim 7, characterized in that In the grid plate assembly close to the baffle, the second grid plate includes a first plate group and a second plate group stacked along the stacking direction of the heat exchange plate, the first plate group is arranged close to the baffle, and the plate spacing of the first plate group is greater than the plate spacing of the second plate group.

9. The heat exchanger according to claim 8, characterized in that The plate spacing of the second plate group is greater than or equal to the spacing of the heat exchange flow channels, the plate spacing of the first plate group is less than or equal to 1.5 times the plate spacing of the second plate group, and the plate stacking thickness of the first plate group is 1 / 4 to 1 / 3 of the plate stacking thickness of the second grid plate.

10. The heat exchanger according to claim 8, characterized in that In the grid plate assembly close to the baffle, the plate spacing of the first grid plate is greater than or equal to the plate spacing of the second plate group; or, in the grid plate assembly close to the baffle, the first grid plate includes a third plate group and a fourth plate group stacked along the stacking direction of the heat exchange plate, a partition parallel to the baffle is provided between the third plate group and the fourth plate group, the third plate group is arranged close to the baffle, and the plate spacing of the third plate group is greater than the plate spacing of the fourth plate group.

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