Asymmetric plate heat exchanger

Abstract

The present invention provides an asymmetric plate heat exchanger, the heat exchange zone on the heat exchanger adopts a corrugated convex structure, the heat exchange zone is composed of more than two asymmetric heat exchange partitions arranged in sequence from left to right, the fluid channel of the right heat exchange partition in adjacent heat exchange partitions is on the same horizontal line as the corrugated convexity of the left heat exchange partition, the corrugated convexity of the right heat exchange partition in adjacent heat exchange partitions is on the same horizontal line as the fluid channel of the left heat exchange partition, the height H of the corrugated convex structure in each heat exchange partition decreases along the flow direction of the medium; the number of corrugated convex structures contained in the heat exchange partition decreases from the medium inlet direction to the medium outlet direction. The asymmetric plate heat exchanger of the present invention can reduce the along-the-way resistance loss and local resistance loss generated in the medium flow process, thereby reducing the medium energy loss and the overall power consumption of the equipment.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchangers, and in particular to a plate-type heat exchanger with an asymmetric structure. Background Art

[0002] Plate heat exchangers have been widely used in the fields of petroleum, chemical industry, textile, HVAC, food, medicine, etc. for more than 100 years since their introduction due to their high heat exchange efficiency, compact structure, flexible assembly and disassembly. With the deepening of the world energy crisis and the increasing requirements for environmental protection in my country, efficient, energy-saving and economical plate heat exchangers will have a broader prospect in the future market development process.

[0003] The plate heat exchanger is assembled by staggered arrangement of plate heat exchangers of exactly the same shape and specification. Therefore, the plate heat exchanger is the core component of the plate heat exchanger, which mainly includes the medium inlet and outlet, the guide area, the heat exchange area, and the gasket groove. At present, most of the plate heat exchangers on the market are symmetrical structures, and the corrugation form is relatively simple, resulting in insufficient fluid heat exchange efficiency, and the overall pressure drop of the equipment and the power consumption of the pump are large.

[0004] Therefore, optimizing the structure of the plate heat exchanger to promote the convective heat transfer efficiency of cold and hot fluids and reduce the medium flow pressure drop and equipment power consumption is of great significance for the further promotion of plate heat exchangers. Summary of the invention

[0005] In view of this, the present invention provides an asymmetric plate heat exchanger, which optimizes the heat exchange area structure of the plate heat exchanger to improve the overall heat exchange efficiency of the equipment, and reduce the resistance and pressure drop of the medium flow process, as well as the overall power consumption of the equipment.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an asymmetric plate heat exchanger, which is composed of a cold fluid inlet, a cold fluid outlet, a hot fluid inlet, a hot fluid outlet, a gasket groove, a guide area, a heat exchange area and a guide rod groove. The heat exchange area adopts a corrugated convex structure, and the heat exchange area is composed of more than two asymmetric heat exchange partitions arranged in sequence from left to right.

[0007] Furthermore, the fluid channel of the right heat exchange partition and the corrugated protrusion of the left heat exchange partition among the adjacent heat exchange partitions are on the same horizontal line.

[0008] Furthermore, the corrugated protrusion of the right heat exchange partition and the fluid channel of the left heat exchange partition in the adjacent heat exchange partitions are on the same horizontal line.

[0009] Furthermore, the height H of the corrugated protrusion structure in each heat exchange zone decreases along the medium flow direction.

[0010] Furthermore, the height H of the corrugated protrusion structure satisfies:

[0011]

[0012] Among them, H0 is the height of the first corrugated protrusion, L' is the distance between the corrugated protrusion structure corresponding to H and the starting edge of the heat exchange zone, Q is the volume flow rate of the medium, μ is the medium viscosity, ρ is the medium density, f is the friction resistance coefficient of the medium flow process, W is the width of the plate heat exchanger, R0 is the flow constant, the value is 2500-4000, c is the structural coefficient, the value is 0.5-0.8, η is the resistance coefficient, the value is 1.0-1.5.

[0013] Furthermore, the number of the corrugated protrusion structures included in the heat exchange partition decreases from the medium inlet direction to the medium outlet direction.

[0014] Compared with the prior art, the present invention has the following beneficial effects: the plate heat exchanger of the present invention optimizes the height of the corrugated protrusion structure in the heat exchange area, so that the corrugation height gradually decreases along the flow direction of the medium, thereby reducing the foot resistance loss of the corrugated protrusion structure to the fluid medium, and effectively reducing the power consumption of the equipment. At the same time, the height of the corrugation is reduced, so that the distance between the plates is increased, ensuring that the appropriate degree of turbulence is always maintained during the flow of the medium, and significantly improving the convective heat transfer efficiency of the equipment. By optimizing the adjacent heat exchange partition structure, the fluid channels on the left and right sides are staggered with the corrugated protrusions, which can significantly increase the effective heat exchange area and further improve the overall operating efficiency of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the overall structure of the plate heat exchanger provided by the present invention;

[0016] Figure 2 A schematic diagram of the structure of the heat exchange area of ​​the herringbone corrugated plate provided by the present invention;

[0017] Figure 3 A schematic diagram of the structure of the horizontal corrugated plate heat exchange area provided by the present invention;

[0018] Figure 4 A side view of the horizontal corrugated plate heat exchange area provided by the present invention. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the embodiments of the present invention, the following briefly introduces the drawings required in the technical solution of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0020] The present invention discloses an asymmetric plate heat exchanger to improve the convective heat transfer efficiency of the heat exchanger and reduce the resistance pressure drop during the medium flow process and the overall power consumption of the equipment. Figure 1 The overall structure diagram of the plate heat exchanger provided by the present invention is composed of a cold fluid inlet 1, a cold fluid outlet 2, a hot fluid inlet 3, a hot fluid outlet 4, a gasket groove 5, a guide area 6, a heat exchange area 7 and a guide rod groove 8. Among them, the heat exchange area 7 is the core area of ​​convective heat transfer of cold and hot fluids, which directly affects the overall heat transfer efficiency of the plate heat exchanger.

[0021] The heat exchange zone 7 of the plate heat exchanger provided by the present invention is composed of more than two asymmetric heat exchange partitions arranged in sequence from left to right. A fluid channel is formed in the middle of the adjacent corrugated protrusion structures in each heat exchange partition, and the fluid channel of the right heat exchange partition in the adjacent heat exchange partitions is on the same horizontal line as the corrugated protrusion of the left heat exchange partition, and the corrugated protrusion of the right heat exchange partition in the adjacent heat exchange partitions is on the same horizontal line as the fluid channel of the left heat exchange partition, so that the turbulence degree of the medium when flowing through different heat exchange partitions can be significantly enhanced, thereby strengthening the convective heat exchange process of the cold and hot media.

[0022] The height H of the corrugated protrusion structure in each heat exchange zone of the plate heat exchanger provided by the present invention decreases along the flow direction of the medium; and the height H of the corrugated protrusion structure satisfies:

[0023]

[0024] Among them, H0 is the height of the first corrugation, L' is the distance between the corrugated structure corresponding to H and the starting edge of the heat exchange zone, Q is the volume flow rate of the medium, μ is the viscosity of the medium, ρ is the density of the medium, f is the friction resistance coefficient of the medium flow process, W is the width of the plate heat exchanger, R0 is the flow constant, which is 2500-4000, c is the structural coefficient, which is 0.5-0.8, and η is the resistance coefficient, which is 1.0-1.5. The plate heat exchangers are arranged in a staggered manner to form a plate heat exchanger, and a medium flow area is formed between two adjacent plate heat exchangers. The width of the medium flow area is generally less than 1cm. Therefore, when the cold and hot media flow between the plates, they are mainly affected by the friction force of the plates and the shear force of the fluid, while the effect of the gravity of the fluid itself can be almost ignored. Resistance loss (i.e., pressure drop head) is generated during the flow of cold and hot media, including composition resistance loss and local resistance loss, resulting in a gradual decrease in energy during the flow of the medium. Therefore, for the corrugated structure of the heat exchange area, its height is gradually reduced according to the above formula along the medium flow direction. On the one hand, it can reduce the resistance loss generated by the medium flow process, and on the other hand, it can gradually increase the width of the flow area between the heat exchange plates to form turbulence compensation, thereby ensuring that a sufficient degree of turbulence is always maintained during the medium flow process, significantly improving the overall heat exchange efficiency of the equipment.

[0025] The number of corrugated protrusion structures contained in the heat exchange area of ​​the plate heat exchanger provided by the present invention gradually decreases from the medium inlet side to the outlet side. When the cold and hot media flow diagonally between the heat exchanger plates, the effective utilization rate of the heat exchange zone is not evenly distributed. The effective area utilization rate of the heat exchange partition on the medium inlet side is greater than the effective area utilization rate of the heat exchange partition on the medium outlet side. Therefore, by optimizing the number of corrugated structures in different heat exchange partitions, the utilization rate of the effective heat exchange area of ​​the heat exchange zone can be significantly improved, thereby improving the overall heat exchange efficiency of the heat exchanger plate.

[0026] Example 1

[0027] like Figure 1 The present invention provides a structural schematic diagram of a plate heat exchanger, which is composed of a cold fluid inlet 1, a cold fluid outlet 2, a hot fluid inlet 3, a hot fluid outlet 4, a gasket groove 5, a guide area 6, a heat exchange area 7 and a guide rod groove 8. The heat exchange area is the core area of ​​convective heat transfer of cold and hot fluids, which directly affects the overall heat transfer efficiency and flow pressure drop of the plate heat exchanger.

[0028] like Figure 2 A structural schematic diagram of the heat exchange zone of a herringbone corrugated plate is given. The height of the corrugated protrusions in the heat exchange zone gradually decreases along the flow direction of the medium, and conforms to the height change law provided by the present invention. In a plate heat exchanger, two adjacent plate heat exchangers form cold and hot fluid circulation areas in turn, supplying cold and hot fluid media to flow, and convective heat exchange is performed through the middle heat exchanger. At present, the corrugated structures of the plate heat exchangers on the market all adopt equal height design, which on the one hand causes excessive resistance loss and local loss along the flow process of the medium, forming a large medium energy loss (i.e., head loss), and at the same time causes the medium velocity to decrease during the flow process, thereby affecting the turbulence degree of the medium and the convective heat exchange effect. The plate heat exchanger provided by the present invention has a corrugated structure whose height gradually decreases along the flow direction of the medium, which can significantly reduce the resistance loss and local resistance loss along the flow process of the medium, and can ensure that the turbulence degree is still high after the medium velocity is reduced, thereby greatly improving the overall convective heat exchange efficiency of the heat exchanger. And the corrugated form can be different structures such as triangle, trapezoid, arc, etc., all of which have a high heat exchange effect.

[0029] The number of heat exchange partitions contained in the heat exchange zone should be no less than 2. In this embodiment, the heat exchange zone is composed of four heat exchange partitions. For the vertically upward flowing medium, the lower right corner is the medium inlet, and the upper left corner is the medium outlet. Therefore, the flow form of the medium in the heat exchange plate is diagonal flow, and the distribution of the convective heat transfer area utilization rate shows a pattern of decreasing from the medium inlet side to the outlet side. Therefore, the plate heat exchanger provided by the present invention has a greater number of corrugated protrusion structures in the heat exchange partition on the inlet side than the number of corrugated protrusion structures in the heat exchange partition on the medium outlet side, which can improve the effective utilization rate of the heat exchange area of ​​the heat exchange plate, thereby significantly improving the overall heat exchange efficiency of the heat exchange plate.

[0030] Example 2

[0031] like Figure 3 A schematic diagram of the heat exchange zone of a horizontal corrugated plate is given. In the existing horizontal corrugated plate, the heights of the corrugated protrusions of the same heat exchange plate are all the same, and the number of corrugated structures in different heat exchange zones is basically the same, which cannot give full play to the effective heat exchange area of ​​the heat exchange zone, and the medium flow resistance is also high. The plate-type heat exchange plate with an asymmetric structure provided by the present invention has a horizontal corrugation height in the heat exchange zone that gradually decreases along the flow direction of the medium, which can enable the cold and hot fluids to obtain a higher heat transfer efficiency of the heat exchange plate under the premise of lower energy loss. In addition, the corrugated structures and fluid channels in adjacent heat exchange zones are staggered, which can further enhance the convective heat transfer process when the medium flows through different heat exchange zones, and promote the convective heat transfer of cold and hot fluids in the heat exchange zone. At the same time, the number of protruding structures in the heat exchange zone decreases from the medium inlet side to the medium outlet side, which can further explore the convective heat transfer efficiency in the area with a strong degree of medium turbulence, and reduce the convective heat transfer process in the area with a smaller medium energy, thereby optimizing the distribution of the effective heat exchange area of ​​the entire heat exchange plate, achieving the purpose of improving the heat exchange efficiency of the heat exchange plate and reducing the energy loss of the fluid medium.

[0032] like Figure 4 , which is a side view of the heat exchange area of ​​this embodiment. It can be clearly seen from the figure that the height of the protrusion structure (the protrusion used in this embodiment is arc-shaped) gradually decreases along the flow direction of the medium. This design can achieve the optimal goal of reducing medium energy loss and improving the convective heat exchange efficiency of cold and hot fluids.

[0033] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. An asymmetric plate heat exchanger, comprising a cold fluid inlet (1), a cold fluid outlet (2), a hot fluid inlet (3), a hot fluid outlet (4), a gasket groove (5), a guide area (6), a heat exchange area (7) and a guide rod groove (8), characterized in that: The heat exchange zone (7) adopts a corrugated convex structure, and the heat exchange zone (7) is composed of more than two asymmetric heat exchange partitions arranged in sequence from left to right; the fluid channel of the right heat exchange partition and the corrugated convex of the left heat exchange partition in adjacent heat exchange partitions are on the same horizontal line; the corrugated convex of the right heat exchange partition and the fluid channel of the left heat exchange partition in adjacent heat exchange partitions are on the same horizontal line; the height H of the corrugated convex structure in each heat exchange partition decreases along the flow direction of the medium; The height H of the corrugated protrusion structure satisfies: Among them, H0 is the height of the first corrugated protrusion, L' is the distance between the corrugated protrusion structure corresponding to H and the starting edge of the heat exchange zone, Q is the volume flow rate of the medium, μ is the medium viscosity, ρ is the medium density, f is the friction resistance coefficient of the medium flow process, W is the width of the plate heat exchanger, R0 is the flow constant, the value is 2500-4000, c is the structural coefficient, the value is 0.5-0.8, η is the resistance coefficient, the value is 1.0-1.

5.

2. The asymmetric plate heat exchanger according to claim 1, characterized in that: The number of the corrugated protrusion structures included in the heat exchange partition decreases from the medium inlet direction to the medium outlet direction.

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