A vortex turbulent fin heat exchange tube and heat exchanger

Abstract

The invention discloses a novel vortex turbulent fin heat exchange tube and heat exchanger, comprising a tube body, characterized in that: the two ends of the tube body are light tube sections, the tube body between the light tube sections at the two ends is arranged alternately according to the fin section and the vortex section, or arranged alternately according to the fin section and the turbulent section, there is a transition gap between the fin section and the vortex section or the turbulent section, heat exchange fins are arranged outside the fin section, a structure that can generate vortex flow when gas flows through is arranged on the tube wall of the vortex section, and a structure that can generate turbulent flow when gas flows through is arranged on the tube wall of the turbulent section. It has both high heat exchange performance and anti-dust accumulation characteristics, and can greatly reduce dust accumulation between fins. Under the same heat load, the equipment is lighter; under the same flow rate, the tube spacing is greater than that of the cellular tube or the light tube, which is convenient for making elbows, and the resistance of a single elbow is smaller. By adjusting the angle of the fin, the flow field of the medium outside the tube can also be corrected and regulated, so as to achieve the effect of optimizing the flow field of large equipment.

Description

Technical Field

[0001] The invention relates to the field of heat exchanger tubes, and in particular to a novel vortex turbulent fin heat exchange tube and a heat exchanger. Background Art

[0002] In the existing tubular heat exchanger, the main heat exchange tubes used in the air-water heat exchange condition are plain tubes, finned tubes, t-cell tubes, etc. The heat exchange form is that the air flows through the shell side and the water flows through the tube side.

[0003] Among them, the bare tube is the most widely used, but it has the disadvantages of poor heat exchange effect of single tube and large total resistance of equipment. The heat exchange of finned tube is good outside the tube, but the heat exchange inside the tube is not enhanced, and the outside of the tube is easy to be blocked by dust. The tungsten tube has good comprehensive performance and can resist dust accumulation, but when dense arrangement is required, it is inconvenient to process and manufacture because the turning radius of the elbow is too small, and the resistance of the elbow will increase if the turning radius is too small. In reality, if it is really not suitable to set up such a sharp bend, it is often forced to reduce the flow velocity on the windward side.

[0004] Therefore, there is an urgent need for a heat exchange tube type that has strong heat exchange capacity, outstanding dust resistance, and can adapt to layout schemes that require smaller spacing between tubes.

[0005] At the same time, due to the uneven temperature of the flue gas itself in large heat exchangers, when flowing horizontally, the temperature of the upper medium is often higher than that of the lower medium due to the different densities of flue gases at different temperatures, resulting in stratification of the temperature field of the heat exchanger, affecting the heat exchange effect of the heat exchanger. Although the separate setting of guide plates can improve this situation, it requires additional space and will increase system resistance. Therefore, there is an urgent need for a new type of heat exchange pipe that can take into account both guide and heat exchange on the market. Summary of the invention

[0006] In view of the problems of the prior art, the first purpose of the present invention is to provide a new type of vortex turbulent fin heat exchange tube to increase the heat exchange performance of the heat exchange tube, and the second purpose is to provide a heat exchanger.

[0007] To achieve the above first purpose, the present invention is implemented through the following technical solutions: a new type of vortex turbulent fin heat exchange tube, including a tube body, characterized in that: the two ends of the tube body are smooth tube sections, and the tube body between the smooth tube sections at the two ends is alternately arranged according to the fin section and the vortex section, or is alternately arranged according to the fin section and the turbulent section, and there is a transition gap between the fin section and the vortex section or the turbulent section. Heat exchange fins are arranged outside the fin section, and a structure that can generate a vortex flow when the gas flows through is arranged on the tube wall of the vortex section, and a structure that can generate a turbulent flow when the gas flows through is arranged on the tube wall of the turbulent section.

[0008] Preferably, the vortex section is a t-cell tube section. T-cells are present both inside and outside the t-cell tube.

[0009] The inner wall of the finned tube is smooth, which is not much different from that of an ordinary light tube. Because of the protrusions in the finned tube, the heat transfer of the medium in the tube is enhanced to a certain extent. And because the tube sections of the finned tube are only arranged intermittently, the resistance in the tube is increased compared to the light tube, but it is less than that of the whole finned tube. Although the protrusions in the finned tube are only arranged intermittently, the main mechanism of heat transfer enhancement is to enhance disturbance rather than expand the area, so the heat transfer in the tube is improved to a level close to that of the whole finned tube.

[0010] The cells and fins outside the tube both have the effect of enhancing heat exchange. The difference is that the fin part relies on expanding the heat exchange area to enhance heat exchange, while the cell part relies on improving the heat transfer coefficient. When arranged into a heat exchange tube assembly in the following manner, the fin sections and vortex sections of two adjacent heat exchange tubes are arranged alternately, and the fin section of one corresponds to the vortex section of the other. Since the fins and cells are not only arranged intermittently on the tube, but also arranged at intervals in the direction of flue gas flow, the spiral airflow generated by the cells of the cell tube can directly purge the gap between the heat exchange fins, and can drive the medium between the heat exchange fins to form a vortex flow, which not only enhances the heat exchange on the heat exchange fin surface, but also has a dust cleaning effect, which can greatly reduce the dust accumulation between the heat exchange fins. The two forms of enhanced heat exchange are effectively combined to produce an effect of 1+1>2.

[0011] The heat transfer coefficient inside the tube can be increased by 1.2-2.4 times compared with the bare tube; the heat transfer coefficient outside the tube can be increased by 3-9 times compared with the bare tube.

[0012] In the above scheme: the spoiler section is a vortex tube section. Or the spoiler section is a corrugated tube section. Or the spoiler section is a twisted tube section. Or the spoiler section is other heat exchange enhancement tube sections that rely on increasing disturbance. The lengths of the wing section and the vortex section or spoiler section are the same or different.

[0013] As shown in the figure, vortex segments, twisted segments, and wave segments can also enhance the heat transfer effect and form enhanced turbulence.

[0014] The second object of the present invention is achieved as follows: A heat exchanger, including a heat exchange tube assembly, wherein the heat exchange tube assembly includes a plurality of heat exchange tubes arranged side by side, characterized in that: the heat exchange tube is the new type of vortex turbulent fin heat exchange tube, the fin sections, vortex sections or turbulent sections of two adjacent heat exchange tubes are arranged alternately, and the fin section of one heat exchange tube corresponds to the vortex section or turbulent section of the other heat exchange tube. The heat exchanger adopts a specially made heat exchange tube of this technology as a heat exchange and flow guiding element. The fins of the fin tube section adopt a customized inclination angle to guide the medium gas flow to flow in a specified direction. It can play a flow guiding role.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The heat flux density of the single tube of the present invention is large, far exceeding that of the light tube and higher than that of the tungsten tube. It has high heat exchange performance and anti-dust accumulation characteristics, which can greatly reduce dust accumulation between fins.

[0017] 2. Under the same heat load, the equipment is lighter. Under the same flow rate, the tube spacing is larger than that of the cellular tube or the smooth tube, which is convenient for making elbows, and the resistance of a single elbow is smaller.

[0018] 3. Under the same heat load, it saves more materials compared with bare tubes and finned tubes.

[0019] 4. Since the vortex tube section and the fin section are arranged in a staggered manner, even if the fin tube section is blocked, the dinosaur tube section will not be blocked due to its anti-dust and scaling characteristics. Although the heat exchange capacity of the heat exchanger is reduced, the flow channel can always be kept unobstructed to a certain extent. As the flow channel becomes narrower, the vortex intensity and disturbance of the dinosaur section increase, and the fin section can be cleaned to a certain extent, which can keep the heat exchanger clean for a long time.

[0020] 5. Due to the staggered arrangement of wing segments and vortex segments, there is a strong rectifying effect and the flow field distribution is more uniform and reasonable.

[0021] 6. Because the wing segments and vortex segments are staggered in the horizontal direction and the front-to-back direction, and there is a resistance difference between the wing segments and the vortex segments at the same flow rate, the medium outside the tube will undergo multiple diversions and confluences when flowing through the tube bundle, which will enhance the mixing of the medium. There will be a more uniform temperature field on the same cross section, which is conducive to controlling the temperature field and preventing low-temperature corrosion.

[0022] 7. Without adding extra space and resistance, the heat exchanger has its own flow guidance effect, which can optimize the flow field and improve the overall heat exchange effect of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of embodiment 1 of the present invention.

[0024] Figure 2 This is a schematic diagram of the structure of a heat exchange tube assembly formed by arranging the heat exchange tubes of Example 1.

[0025] Figure 3 Schematic diagram of the heat exchanger.

[0026] Figure 4 This is the other side view of the heat exchanger.

[0027] Figure 5 Schematic diagram of vortex generation.

[0028] Figure 6 This is a schematic diagram of the structure of Example 2.

[0029] Figure 7 This is a schematic diagram of the structure of Example 3.

[0030] Figure 8 This is a schematic diagram of the structure of Example 4.

[0031] Fig. 9 It is a comparison chart of the external heat transfer coefficient of the new vortex turbulent fin heat exchange tube of Example 1 and the bare tube, vortex tube and fin tube.

[0032] Fig.10 This is a schematic diagram of Example 5. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with embodiments and drawings.

[0034] Example 1

[0035] like Figure 1-5 As shown, the new vortex turbulent fin heat exchange tube includes a tube body, and the two ends of the tube body are light tube sections 1. The tube body between the light tube sections 1 at the two ends is arranged alternately in sequence according to the fin section 2 and the vortex section 3, that is, from left to right as shown in the figure, it is light tube section, fin section, vortex section, fin section, vortex section...light tube section, or light tube section, vortex section, fin section...light tube section. There is a transition gap 4 between the fin section 2 and the vortex section 3. The vortex section 3 is a triceratops tube section. The inner and outer walls of the triceratops section are both provided with triceratops, and the triceratops are distributed in a spiral shape. Heat exchange fins are arranged outside the fin section 2, and a structure that can generate a vortex flow when the gas flows through is arranged on the tube wall of the vortex section 3. The lengths of the fin section 2 and the vortex section 3 are the same or different. In this embodiment, the same length is convenient for arrangement.

[0036] A heat exchanger includes a heat exchange tube assembly. When arranged into a heat exchange tube assembly of the heat exchanger, a plurality of heat exchange tubes are arranged side by side, and the fin sections 2 and vortex sections 3 of two adjacent heat exchange tubes are arranged alternately, that is, the fin section 2 of one heat exchange tube corresponds to the vortex section 3 of another heat exchange tube. The heat exchanger also includes a shell, which is a prior art and will not be described in detail here.

[0037] Under the same Re condition, the heat transfer coefficient outside the tube is compared with that of the bare tube, vortex tube and finned tube. Fig. 9 As shown:

[0038] It can be seen from the figure that the heat transfer coefficient of the D-cell finned tube (new type of vortex turbulent finned heat exchange tube) is better than that of the light tube and vortex tube, but lower than that of the finned tube. However, due to the same base tube area, the weight of the finned tube is much heavier, and the weight of the D-cell finned tube is only 50%-70% of the finned tube of the same length. After weight correction, at the same Rayleigh number and the same heat load, the material weight required for the D-cell finned tube is only 30-70% of that of the light tube, which is also slightly lower than that of the finned tube, about 70-90% of the finned tube.

[0039] At the same time, because the intercellular finned tube structure is more compact and the spacing is smaller, the equipment size is smaller and the equipment resistance is lower under the same load.

[0040] Embodiment 2:

[0041] The rest is the same as that of the embodiment 1, except that the vortex section is replaced by a spoiler section, such as the vortex tube section 5. The vortex tube is a prior art and will not be described in detail here.

[0042] Example 3

[0043] The rest is the same as the first embodiment, except that the vortex section is replaced by a spoiler section, such as the bellows section 6. The bellows is a prior art and will not be described in detail here.

[0044] Example 4

[0045] The rest is the same as that of the first embodiment, except that the vortex section is replaced by a spoiler section, such as a twisted tube section 7. The twisted tube is a prior art and will not be described in detail here.

[0046] Example 5

[0047] The other aspects are the same as those of Example 1, except that the fins of the fin segment are designed at a specific angle, with an inclination angle of 30-60°. Fig.10 The guide tube guides the medium outside the tube to flow in a directional manner.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat exchanger, comprising a heat exchange tube assembly, wherein the heat exchange tube assembly comprises a plurality of heat exchange tubes arranged side by side, characterized in that: The heat exchange tube is a vortex turbulent fin heat exchange tube, which includes a tube body, both ends of the tube body are light tube sections, the tube body between the light tube sections at both ends is alternately arranged according to fin sections and vortex sections, or alternately arranged according to fin sections and turbulent sections, there is a transition gap between the fin section and the vortex section or the turbulent section, heat exchange fins are arranged outside the fin section, a structure that can generate vortex flow when gas flows through is arranged on the tube wall of the vortex section, and a structure that can generate turbulent flow when gas flows through is arranged on the tube wall of the turbulent section; The fin sections, vortex sections or turbulent sections of two adjacent heat exchange tubes are arranged alternately, and the fin section of one heat exchange tube corresponds to the vortex section or turbulent section of the other heat exchange tube.

2. The heat exchanger according to claim 1, characterized in that: The vortex section is a t-cell tube section.

3. The heat exchanger according to claim 1, characterized in that: The spoiler section is a vortex tube section.

4. The heat exchanger according to claim 1, characterized in that: The spoiler section is a corrugated tube section.

5. The heat exchanger according to claim 1, characterized in that: The spoiler section is a twisted pipe section.

6. The heat exchanger according to claim 1, characterized in that: The turbulent section is another heat exchange enhancement pipe section that enhances heat exchange by enhancing turbulence.

7. The heat exchanger according to any one of claims 1 to 6, characterized in that: The lengths of the wing section and the vortex section or the spoiler section are the same or different.

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