A plate heat exchanger

Abstract

An embodiment of the present invention relates to the technical field of heat exchangers and provides a plate heat exchanger. The plate heat exchanger includes a spiral structural member and multiple layers of heat exchange plates stacked thereon. The heat exchange plates are provided with through holes, and the through holes of the multiple layers of heat exchange plates communicate to form an inlet channel. The inlet of the fluid channel between the multiple layers of heat exchange plates communicates with the inlet channel, and the spiral structural member is disposed in the inlet channel. By arranging the spiral structural member in the inlet channel, the vertical flow of the fluid in the inlet channel is converted into a spiral flow, so that the included angle between the flow velocity direction of the fluid and the heat exchange plates is reduced, and a centrifugal force is generated. Under the action of the centrifugal force, the fluid enters each layer of fluid channels, reducing the inlet resistance of the fluid entering the fluid channels and improving the problem of uneven fluid flow rate entering each layer of fluid channels, thereby improving the heat exchange performance of the plate heat exchanger.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchangers, and particularly to a plate heat exchanger. Background Art

[0002] Plate heat exchangers are widely used because of their high heat transfer efficiency, low heat loss, compact and lightweight structure, and small floor area. A plate heat exchanger is formed by stacking a series of heat exchange plates with a certain corrugated shape, and fluid channels for cold fluid and hot fluid to flow through are formed between each layer of heat exchange plates. The cold and hot fluids exchange heat through the heat exchange plates.

[0003] Two through holes are provided at corresponding positions on each layer of heat exchange plates of the plate heat exchanger. After multiple heat exchange plates are stacked, two inlet channels of the plate heat exchanger are formed. After the hot fluid and the cold fluid are respectively introduced into different inlet channels, they enter the fluid channels between each layer of heat exchange plates from the inlet channels. However, since the velocity direction of the fluid at the inlet section of the inlet channel is perpendicular to the heat exchange plates, the flow rates of the hot fluid or the cold fluid in the inlet channel entering each layer of fluid channels are inconsistent, causing serious flow non-uniformity, thereby affecting the heat transfer performance of the plate heat exchanger. Summary of the Invention

[0004] An embodiment of the present invention provides a plate heat exchanger to solve the problem that in the existing plate heat exchanger, the flow rates of the fluid entering each layer of fluid channels from the inlet channel are inconsistent, which affects the heat transfer performance of the plate heat exchanger.

[0005] An embodiment of the present invention provides a plate heat exchanger, including a spiral structure member and multiple layers of heat exchange plates stacked. The heat exchange plates are provided with through holes, and the through holes of multiple layers of the heat exchange plates are communicated to form an inlet channel. The inlet of the fluid channel between the heat exchange plates is communicated with the inlet channel, and the spiral structure member is arranged in the inlet channel.

[0006] For the plate heat exchanger according to an embodiment of the present invention, the pitch of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel.

[0007] For the plate heat exchanger according to an embodiment of the present invention, the spiral radius of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel.

[0008] For the plate heat exchanger according to an embodiment of the present invention, the spiral structure member is eccentric toward the side close to the inlet of the fluid channel.

[0009] For the plate heat exchanger according to an embodiment of the present invention, the spiral eccentricity of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel.

[0010] The plate heat exchanger according to an embodiment of the present invention, wherein the spiral structural member is an integrally formed structure.

[0011] The plate heat exchanger according to an embodiment of the present invention, wherein the spiral structural member is fixedly connected to the side wall of the inlet passage.

[0012] The plate heat exchanger according to an embodiment of the present invention further includes a central column, and the spiral structural member is installed on the central column.

[0013] The plate heat exchanger according to an embodiment of the present invention, wherein the spiral structural member includes a deflector plate, and a plurality of the deflector plates are spirally wound around the central column.

[0014] The plate heat exchanger provided by the embodiment of the present invention converts the vertical flow of the fluid in the inlet passage into a spiral flow by arranging a spiral structural member in the inlet passage, reduces the angle between the flow velocity direction of the fluid and the heat exchange plate, and generates a centrifugal force. Under the action of the centrifugal force, the fluid enters each layer of fluid passages, reduces the inlet resistance of the fluid entering the fluid passages, improves the problem of uneven fluid flow rate entering each layer of fluid passages, and improves the heat exchange performance of the plate heat exchanger. Description of the Drawings

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

[0016] Figure 1 is a schematic structural diagram of a plate heat exchanger in the prior art;

[0017] Figure 2 is a schematic diagram of the flow of hot and cold fluids in a plate heat exchanger in the prior art;

[0018] Figure 3 is a schematic diagram of the fluid flow in a plate heat exchanger with a spiral structural member installed according to an embodiment of the present invention;

[0019] Figure 4 is the inlet flow rate distribution characteristic of each layer of fluid passages when no spiral structural member is installed according to an embodiment of the present invention;

[0020] Figure 5 is the inlet flow rate distribution characteristic of each layer of fluid passages when an equal pitch spiral structural member is installed according to an embodiment of the present invention;

[0021] Figure 6 is a schematic structural diagram of a variable pitch spiral structural member according to an embodiment of the present invention;

[0022] Figure 7 It is the inlet flow rate distribution characteristic of each layer of fluid channels when the gradient pitch spiral structural member is installed in the embodiment of the present invention;

[0023] Figure 8 It is a schematic structural diagram of the variable spiral radius spiral structural member in the embodiment of the present invention;

[0024] Figure 9 It is a schematic diagram of the eccentric spiral structural member in the embodiment of the present invention.

[0025] Reference numerals:

[0026] 1, heat exchange plate; 11, first through hole; 12, second through hole; 13, cold fluid inlet channel; 14, hot fluid inlet channel; 2, spiral structural member. Specific embodiments

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0028] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited. The terms "first" and "second" are used for numbering the product components for clear description and do not represent any substantial difference. The directions of "left" and "right" are subject to the directions shown in the drawings. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] The following will be combined with Figures 1-9 Describe the plate heat exchanger of the embodiments of the present invention.

[0031] As Figure 1 shown is a schematic structural diagram of a plate heat exchanger in the prior art, where the two flow paths indicated by the arrows are the flow paths of the hot fluid and the cold fluid respectively. AsFigure 2 The figure shows a schematic diagram of the flow of cold and hot fluids in a plate heat exchanger in the prior art. The fluids flow linearly and perpendicularly to the heat exchange plates in the inlet channels. In the area near the inlet end of the inlet channels, due to the relatively large fluid flow resistance, the flow velocity is small, resulting in a small amount of fluid in the fluid channels in this area. Most of the fluids flow towards the opposite end of the inlet channels, so that the fluids cannot flow evenly into the fluid channels between each layer of heat exchange plates 1. Accordingly, the heat transfer amount of the heat exchange plates near the inlet end of the inlet channels is small, and the heat transfer amounts of each layer of heat exchange plates along the fluid flow direction are uneven, which affects the heat transfer performance of the plate heat exchanger.

[0032] In view of the above problems, an embodiment of the present invention provides a plate heat exchanger, which includes a spiral structural member 2 and multiple layers of stacked heat exchange plates 1. The heat exchange plates 1 are provided with through holes, and the through holes of the multiple layers of heat exchange plates 2 are communicated to form an inlet channel. The inlets of the fluid channels between the multiple layers of heat exchange plates 1 are communicated with the inlet channel. The spiral structural member is arranged in the inlet channel. Among them, the length direction of the spiral structural member 2 is the same as the length direction of the inlet channel. The spiral structural member 2 is placed in the inlet channel to make the fluids flow spirally in the inlet channel.

[0033] Among them, as Figure 1 and Figure 2 shown, the through holes include a first through hole 11 and a second through hole 12, and the inlet channel includes a cold fluid inlet channel 13 and a hot fluid inlet channel 14. Multiple first through holes 11 are communicated to form the cold fluid inlet channel 13, and the cold fluid flows in the cold fluid inlet channel 13 along the Figure 1 directions indicated by the rightward and upward arrows in Figure 1 . The fluid channel of the cold fluid is communicated with the cold fluid inlet channel 13. Multiple second through holes 12 are communicated to form the hot fluid inlet channel 14, and the hot fluid flows in the hot fluid inlet channel 14 along the Figure 3 directions indicated by the leftward and downward arrows in

[0034] The plate heat exchanger provided by the embodiment of the present invention converts the vertical flow of the fluid in the inlet channel into a spiral flow by arranging a spiral structural member in the inlet channel, reduces the angle between the flow velocity direction of the fluid and the heat exchange plates, and generates a centrifugal force. The cold and hot fluids enter the corresponding fluid channels of each layer under the action of the centrifugal force, reducing the inlet resistance of the fluid entering the fluid channels, improving the problem of uneven fluid flow rates entering each layer of fluid channels, and enhancing the heat exchange performance of the plate heat exchanger. When the spiral density of the spiral structural member is large enough, the fluid can enter the fluid channels in a direction approximately parallel to the heat exchange plates.

[0035] The embodiment of the present invention conducts a simulation test comparison on the experimental sample of the plate heat exchanger with 16 layers of fluid channels. Since the inlet cross-sectional area of each layer of fluid channels is constant, the distribution of the inlet flow rate can be represented by the distribution of the flow velocity in the inlet channel. As Figure 4 shown is the inlet flow rate distribution characteristic of each layer of fluid channels when the spiral structural member is not installed in the embodiment of the present invention. The fluid enters the inlet channel perpendicular to the heat exchange plates and flows along the inlet channel. Due to the influence of the inlet resistance, the fluid flow rates in several layers of fluid channels near the inlet end of the inlet channel are relatively small, while the fluid flow rates entering each layer of fluid channels along the direction of the fluid in the inlet channel gradually increase, and a relatively large part of the fluid directly penetrates to the opposite end of the inlet channel.

[0036] When the spiral structural member 2 is not installed in the inlet channel, from the first layer at the inlet end of the inlet channel to the 16th layer at the opposite end, the inlet flow rates entering each layer of fluid channels show very high non-uniformity. The inlet flow rates of the fluid channels from the first layer to the seventh layer at the inlet end are lower than the average value by 15%, and the inlet flow rates of the fluid channels from the 12th layer to the 16th layer at the opposite end are higher than the average value by 15%, and the overall shows an upward trend. Therefore, in one embodiment of the present invention, one end of the spiral structural member 2 is located at the inlet end of the inlet channel, and the other end is located at the opposite end of the inlet channel.

[0037] In one embodiment of the present invention, the spiral structural member 2 is a constant pitch spiral structure. As Figure 5 shown is the inlet flow rate distribution characteristic of each layer of fluid channels when the constant pitch spiral structural member is installed in the embodiment of the present invention. It can be seen that after installing the constant pitch spiral structural member in the inlet channel, from the inlet end to the opposite end of the inlet channel, the non-uniformity of the fluid flow rates in each layer of fluid channels is significantly improved.

[0038] According to Bernoulli's theorem, for an incompressible fluid, when the fluid flows in a spiral channel, the following theorem exists at any cross-section of the channel:

[0039] ρ1v1A1 = ρ2v2A2

[0040] Among them, ρ1 and ρ2 are the densities of the fluid at two different positions in the spiral flow channel, v1 and v2 are the flow velocities of the fluid at two different positions in the spiral flow channel, and A1 and A2 are the cross-sectional areas at two different positions in the spiral flow channel respectively.

[0041] In this embodiment, the hot fluid and the cold fluid are in the process of flowing in the plate heat exchanger, and their density changes can be ignored, that is, ρ1 = ρ2, regarded as incompressible fluids. And the cross-sectional area of the spiral flow channel will increase with the increase of the pitch. It can be inferred that by changing the pitch of the spiral structural member, the flow velocity of the fluid in the spiral flow channel can be changed, and the larger the pitch, the smaller the flow velocity of the fluid.

[0042] Also according to the centrifugal force action formula: Among them, R is the radius of the rotational motion of the fluid in the spiral flow channel, m is the flow rate of the fluid in the spiral flow channel, and v is the flow velocity of the fluid in the spiral flow channel. It can be seen that when the spiral radius of the spiral structural member is certain, the radius of the rotational motion of the fluid in the spiral flow channel is also certain. Then when the flow velocity of the fluid decreases, the centrifugal force it receives also decreases accordingly, thereby reducing the flow rate entering the fluid channel.

[0043] From Figure 5 it can be seen that under the action of the equal-pitch spiral structural member, the flow velocity of the fluid near the inlet end of the inlet channel increases significantly, the flow velocity of the fluid near the opposite end decreases significantly, and the flow velocities of the fluid near the inlet end and the opposite end are both higher than the average value, while the flow velocity of the fluid in the middle region is lower than the average value. Therefore, in order to further improve the uniformity of the fluid flow rate entering each layer of fluid channels. Based on the above principle, in the embodiment of the present application, the fluid flow rate entering each layer of fluid channels is adjusted by adjusting the pitch of the spiral structural member 2. As Figure 6 shown is the structural schematic diagram of the variable-pitch spiral structural member in the embodiment of the present invention. In the embodiment of the present invention, the pitch of the spiral structural member 2 gradually decreases from the inlet end to the opposite end of the inlet channel. Since the opposite end of the inlet channel is closed, by reducing the pitch of the spiral structural member near the opposite end of the inlet channel, the flow resistance at the rear section of the spiral flow channel can be increased, forcing more fluid to enter the fluid channels in the middle region. At the same time, reducing the pitch of the spiral structural member can also make up for the adverse effect of the reduced flow rate on the reduced flow velocity, making the flow velocities entering all fluid channels tend to be uniform. For example, the pitch of the spiral structural member 2 changes in a gradient from large to small along the fluid flow direction of the inlet channel. Of course, the pitch of the spiral structural member 2 can uniformly and continuously change from large to small from the inlet end to the opposite end of the inlet channel, or can change from large to small discontinuously, which can be specifically adjusted according to the actual fluid dynamics characteristics in the inlet channel, and the embodiment of the present invention does not make specific limitations.

[0044] As Figure 7The figure shows the inlet flow rate distribution characteristics of each layer of fluid channels when the gradient pitch spiral structure is installed in the embodiment of the present invention. Comparison Figure 5 and Figure 7 It can be seen that, compared with the plate heat exchanger installed with an equal pitch spiral structure, the fluid flow uniformity in each layer of fluid channels of the plate heat exchanger installed with a gradient pitch spiral structure is further improved. Compared with the plate heat exchanger without a spiral structure, the fluid flow uniformity in each layer of fluid channels is increased by 80%.

[0045] According to the above Bernoulli's theorem and centrifugal force formula, it can be known that when the pitch is constant, that is, when the cross-sectional area of the spiral flow channel is constant, the flow velocity of the fluid can be ensured to be consistent. Then, the larger the spiral radius, the smaller the centrifugal force received by the fluid. Therefore, in the embodiment of the present invention, the centrifugal force of the fluid in the spiral flow channel is adjusted by adjusting the spiral radius of the spiral structure, so as to adjust the fluid flow rate entering the fluid channel.

[0046] Specifically, the spiral radius of the spiral structure 2 gradually decreases from the inlet end to the opposite end of the inlet channel. By reducing the spiral radius, the centrifugal force of the fluid near the inlet end of the inlet channel is increased, so as to increase the fluid flow rate entering the fluid channel near the inlet end of the inlet channel, and make the fluid volume in each layer of fluid channels along the entire length direction of the inlet channel tend to be uniform.

[0047] As Figure 8 The figure shows a schematic structural diagram of a variable spiral radius spiral structure in the embodiment of the present invention. Of course, in the case of variable pitch, the fluid flow rate entering each layer of fluid channels can be comprehensively adjusted by combining variable spiral radius. The spiral radius of the spiral structure 2 can uniformly and continuously decrease from large to small or discontinuously decrease from large to small from the inlet end to the opposite end of the inlet channel, and can be specifically adjusted according to the fluid dynamics characteristics in the actual inlet channel. The embodiment of the present invention does not make specific limitations.

[0048] In the above embodiment, the fluid flow rate entering each layer of fluid channels is adjusted by adjusting the pitch and spiral radius of the spiral structure 2, which plays a role in splitting the flow of each layer of fluid channels, so that the fluid enters each layer of fluid channels evenly, thereby improving the heat exchange performance of the plate heat exchanger.

[0049] Furthermore, considering that the fluid channel inlet is located on one side of the inlet channel, in the embodiment of the present invention, the spiral structure 2 is eccentric towards the side close to the inlet of the fluid channel. By making the spiral structure eccentric, the fluid is shifted towards the side of the fluid channel inlet, which can reduce the angle between the velocity direction of the fluid at the fluid channel inlet in the inlet channel and the velocity direction in the fluid channel inlet, reduce the velocity loss of the fluid, and thus reduce the pressure drop of the fluid, which is beneficial to the fluid entering the fluid channel.

[0050] Furthermore, the fluid velocity direction at different positions of the inlet channel can also be adjusted by adjusting the spiral eccentricity along the length direction of the spiral structural member. Specifically, the spiral eccentricity of the spiral structural member 2 gradually decreases from the inlet end to the opposite end of the inlet channel. As Figure 9 shown is a schematic diagram of the eccentric spiral structural member in the embodiment of the present invention. It should be noted that the eccentricity of the spiral structural member 2 from the inlet end to the opposite end of the inlet channel can uniformly and continuously decrease from large to small, or can decrease from large to small discontinuously, and can be specifically adjusted according to the actual hydrodynamic characteristics in the inlet channel. The embodiment of the present invention does not make specific limitations.

[0051] In the embodiment of the present invention, the spiral structural member 2 can be an integrally formed structure, such as a spiral fin. The spiral structural member 2 can be fixedly connected to the side wall of the inlet channel. For example, part or all of the outer edge of the spiral structural member 2 is fixedly connected to the side wall of the inlet channel; the spiral structural member 2 can also be movably placed in the inlet channel for convenient disassembly. Among them, the outer shape of the inlet channel can be set to adapt to the outer shape of the spiral structural member 2, that is, the entire outer edge of the spiral structural member 2 is in contact with or connected to the side wall of the inlet channel 11, forming an integrated design of the spiral structural member 2 and the inlet channel 11, so as to form a complete spiral flow channel in the inlet channel. Thereby further improving the uniformity of the fluid flow rate in the fluid channels between the heat exchange plates 1 of each layer in the printed circuit board heat exchanger and reducing the pressure drop.

[0052] The plate heat exchanger provided by the embodiment of the present invention further includes a central column, and the spiral structural member 2 is installed on the central column. The central column can facilitate the handling operation during the installation and disassembly of the spiral structural member 2. Positioning parts for positioning the central column can also be provided on the end plates at both sides of the plate heat exchanger, such as positioning grooves that cooperate with the ends of the central column. During installation, first install the spiral structural member 2 in the inlet channel through the central column, and at the same time assemble and position one end of the central column with the end plate at the opposite end of the inlet channel, and then assemble and position the other end of the central column with the end plate at the inlet end of the inlet channel, so as to realize the positioning installation of the spiral structural member 2. Among them, when the spiral structural member 2 is a variable-radius spiral structure, to ensure that there is sufficient flow channel space at the position with a small radius, at the spiral section with a small radius, the diameter of the central column can be appropriately reduced. The spiral structural member 2 and the central column are integrally formed or welded and fixed or detachably connected.

[0053] Among them, the spiral structural member 2 can be an integrally formed spiral fin or a structure including a plurality of guide plates. The plurality of guide plates are spirally wound around the central column to facilitate the processing and production of the spiral structural member. The guide plate and the central column can be fixedly connected by welding; they can also be detachably connected, such as by snap connection. In this way, the pitch can be adjusted by adjusting the arrangement density of the guide plates along the axial direction of the central column, or the radius of the spiral can be adjusted by adjusting the size of the guide plates, or the spiral eccentricity can be adjusted by replacing the shape of the guide plates.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A plate heat exchanger, comprising a plurality of heat exchange plates stacked, characterized in that, It further includes a spiral structure member. The heat exchange plate is provided with through holes. The through holes of multiple layers of the heat exchange plates are communicated to form an inlet channel. The inlet of the fluid channel between multiple layers of the heat exchange plates is communicated with the inlet channel. The spiral structure member is arranged in the inlet channel; the pitch of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel; the spiral radius of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel; the spiral structure member is eccentric towards the side close to the inlet of the fluid channel, and the spiral eccentricity of the spiral structure member gradually decreases from the inlet end to the opposite end of the inlet channel.

2. The plate heat exchanger according to claim 1 or as described above, characterized in that, The spiral structure member is an integrally formed structure.

3. The plate heat exchanger according to claim 1 or 2, characterized in that The spiral structure member is fixedly connected to the side wall of the inlet channel.

4. The plate heat exchanger according to claim 1 or 2, characterized in that It further includes a central column, and the spiral structure member is installed on the central column.

5. The plate heat exchanger according to claim 4, characterized in that, The spiral structure member includes a guide plate, and multiple guide plates are spirally wound around the central column.

Images