A phase change heat storage device with folded fins based on bionics

Abstract

The present invention discloses a phase change heat storage device with folded fins based on bionics, which relates to the field of energy storage application technology, including an inner tube of a shell and tube heat exchanger, an outer tube of a shell and tube heat exchanger, and a phase change heat storage folded fin. The outer tube cover of the shell and tube heat exchanger is connected to the outer peripheral side of the inner tube of the shell and tube heat exchanger, and the phase change heat storage folded fin is arranged in the annular area between the inner tube of the shell and tube heat exchanger and the outer tube of the shell and tube heat exchanger. The phase change heat storage folded fin increases the contact area between the phase change heat storage folded fin and the phase change material by folding to increase the area, improves the effective thermal conductivity and heat utilization rate, and accelerates the melting of the phase change heat storage material. At the same time, the design of the structure can ensure the strength of the phase change heat storage folded fin, and can withstand the stress impact on the phase change heat storage folded fin during natural convection of the heat exchanger.

Description

Technical Field

[0001] The invention relates to the technical field of energy storage application, and in particular to a phase change heat storage device with folded fins based on bionics. Background Art

[0002] Traditional high-energy-consuming and high-emission industries such as electricity, chemical industry, and steel have a large amount of waste heat, but the recovery efficiency of industrial waste heat and waste heat in the industry is very low. For example, low-temperature waste heat such as steam waste heat, slag water waste heat, flue gas waste heat, and compressed air waste heat have not yet been developed and utilized, which has resulted in a large part of the energy being wasted, increasing the total energy consumption and generating a large amount of gas emissions. In commercial and civil use, the recovery and utilization of waste heat is also relatively rare, and many waste heat utilization projects have shown many shortcomings in terms of economy and flexibility.

[0003] In today's society, energy conservation has become an important social awareness in the world today. The huge volume and economy of industrial waste heat recovery, and the recovery, storage and utilization of low-temperature waste heat are driving the technological development in related fields. For example, many factories, enterprises, hotels and other places require stable hot water all year round, and the recovery, storage and transportation of waste heat can provide them with corresponding services.

[0004] In the field of waste heat recovery, the use of phase change materials for waste heat recovery is a popular research technology, but it also has problems such as low heat transfer efficiency and slow response speed. Summary of the invention

[0005] The purpose of the present invention is to provide a phase change heat storage device with folded fins based on bionics, which effectively solves the problems of low thermal efficiency and slow response speed of traditional shell and tube heat exchanger systems.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A bionics-based phase change heat storage device with folded fins comprises an inner tube of a shell and tube heat exchanger, an outer tube of the shell and tube heat exchanger, and phase change heat storage folded fins. The outer tube cover of the shell and tube heat exchanger is connected to the outer peripheral side of the inner tube of the shell and tube heat exchanger, and the phase change heat storage folded fins are arranged in an annular area between the inner tube of the shell and tube heat exchanger and the outer tube of the shell and tube heat exchanger.

[0008] Preferably, the phase change heat storage folded ribs include short straight rib segments attached to the outside of the inner tube of the shell and tube heat exchanger, the short straight rib segments are connected to the short straight rib segments attached to the inside of the outer tube of the shell and tube heat exchanger through folded rib segments, and the center lines of the short straight rib segments are in the same radial direction.

[0009] Preferably, the number of the phase-change heat storage folded fins is set to be several, and the several phase-change heat storage folded fins are evenly distributed circumferentially in the annular area between the inner tube of the shell and tube heat exchanger and the outer tube of the shell and tube heat exchanger.

[0010] Preferably, the phase-change heat storage folded ribs are provided in four pieces, and the angle between two adjacent phase-change heat storage folded ribs is 90 degrees.

[0011] Preferably, the shape of the phase-change heat storage folded fin is obtained by using formula (1) and formula (2):

[0012]

[0013]

[0014] Where: r 1 is the outer diameter of the inner tube of the shell and tube heat exchanger; r 2 is the inner diameter of the outer tube of the shell and tube heat exchanger; r is the distance from a point on the x-axis to the center of the inner tube, and the value range is r∈[r 1 , r 2 ]; x is the independent variable; y is the rib position corresponding to the x position.

[0015] Preferably, the thickness of the phase-change heat storage folded fins ranges from 1 to 2 mm.

[0016] Preferably, the outer tube diameter of the shell and tube heat exchanger is no more than 6 times the inner tube diameter of the shell and tube heat exchanger.

[0017] Preferably, the inner tube of the shell and tube heat exchanger is made of metal material.

[0018] Preferably, the material of the phase-change heat storage folded fins is the same as the material of the inner tube of the shell and tube heat exchanger.

[0019] The beneficial effects of the present invention are as follows:

[0020] The phase change heat storage folded fins increase the area by folding, which greatly increases the contact area between the phase change heat storage folded fins and the phase change material, improves the effective thermal conductivity and heat utilization rate, and accelerates the melting of the phase change heat storage material. At the same time, the design of the structure can ensure the strength of the phase change heat storage folded fins and can withstand the stress impact on the phase change heat storage folded fins during natural convection of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of a top view of a phase change heat storage device with folded fins based on bionics in an embodiment of the present invention;

[0022] Figure 2Schematic diagram of the three-dimensional structure of a bionics-based phase change heat storage device with folded fins in an embodiment of the present invention;

[0023] Figure 3 for Figure 2 The schematic diagram of the structure of the outer tube of the shell and tube heat exchanger is omitted;

[0024] Figure 4 for Figure 3 A schematic diagram of the structure from another angle;

[0025] Figure 5 for Figure 3 A schematic diagram of a top view structure;

[0026] Figure 6 for Figure 1 Schematic diagram of the function generation process corresponding to the shape of the folded fins for phase change heat storage.

[0027] Meaning of the reference numerals: 1. Outer tube of shell and tube heat exchanger; 2. Phase change heat storage material; 3. Phase change heat storage folded fins; 4. Inner tube of shell and tube heat exchanger. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly. In addition, the terms "install", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be internally connected between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0030] Reference Figures 1 to 5The present invention provides a phase change heat storage device with folded fins based on bionics, including an inner tube 4 of a shell and tube heat exchanger, an outer tube 1 of a shell and tube heat exchanger, and phase change heat storage folded fins 3. The outer tube 1 of the shell and tube heat exchanger is covered and connected to the outer peripheral side of the inner tube 4 of the shell and tube heat exchanger. The phase change heat storage folded fins 3 are arranged in an annular area between the inner tube 4 of the shell and tube heat exchanger and the outer tube 1 of the shell and tube heat exchanger. The inner tube 4 of the shell and tube heat exchanger carries a working fluid, and a phase change heat storage material 2 is placed in the annular area between the inner tube 4 of the shell and tube heat exchanger and the outer tube 1 of the shell and tube heat exchanger. The present invention uses mathematical analysis to accurately design the shape of the phase change heat storage folded fins. By folding to increase the area, the contact area between the phase change heat storage folded fins and the phase change material is greatly increased, the effective thermal conductivity and heat utilization rate are improved, and the melting of the phase change heat storage material is accelerated. At the same time, the design of the structure can ensure the strength of the phase change heat storage folded fins and can withstand the stress impact on the phase change heat storage folded fins during natural convection of the heat exchanger.

[0031] The phase change heat storage folded fin 3 includes a short straight fin segment attached to the outside of the inner tube 4 of the shell and tube heat exchanger, and the short straight fin segment is connected to the short straight fin segment attached to the inside of the outer tube 1 of the shell and tube heat exchanger through the folded fin segment, wherein the center lines of the short straight fin segments are in the same radial direction. Since the folding area of ​​the fin is too large, it is easy to cause the fin stability to be poor and produce vibration, so the addition of the short straight fin segment helps to improve the stability of the fin.

[0032] The number of phase change heat storage folded fins 3 is set to be several, and the several phase change heat storage folded fins 3 are evenly distributed circumferentially in the annular area between the inner tube 4 of the shell and tube heat exchanger and the outer tube 1 of the shell and tube heat exchanger. Further, the phase change heat storage folded fins 3 are set to be four, and the angle between two adjacent phase change heat storage folded fins 3 is 90 degrees. The thickness of the phase change heat storage folded fins 3 ranges from 1 to 2 mm, which can greatly improve the specific surface area of ​​heat exchange. At the same time, the tortuous fins can guide the internal flow field.

[0033] The inner tube 4 of the shell and tube heat exchanger is made of a metal material with a relatively high thermal conductivity, and the material of the phase change heat storage folded fins 3 is the same as that of the inner tube 4 of the shell and tube heat exchanger.

[0034] The radius of the inner tube 4 of the shell and tube heat exchanger is r 1 , the radius of the outer tube 1 of the shell and tube heat exchanger is r 2 In order to ensure that the phase change heat storage folded fin 3 can be placed between the inner and outer tube diameters, the outer tube diameter of the shell and tube heat exchanger cannot exceed 6 times the inner tube diameter of the shell and tube heat exchanger. Taking a point 4 on the inner tube of the shell and tube heat exchanger as the origin, an x-axis is established radially, and a y-axis is established tangentially at this point. The shape of the phase change heat storage folded fin 3 is consistent with the shape of the function shown below, where x represents the relative position, that is, the x position is a function of the actual tube diameter position.

[0035] The shape of the phase change heat storage folded fin 3 is obtained by using formula (1) and formula (2):

[0036]

[0037]

[0038] Where: r 1 is the outer diameter of the inner tube of the shell and tube heat exchanger; r 2 is the inner diameter of the outer tube of the shell and tube heat exchanger; r is the distance from a point on the x-axis to the center of the inner tube, and the value range is r∈[r 1 , r 2 ]; x is the independent variable; y is the rib position corresponding to the x position.

[0039] The above specifically describes the preferred implementation of the present invention. Of course, the present invention can also take a form different from the above-mentioned implementation mode. Equivalent changes or corresponding modifications made by technicians familiar with the field without violating the spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A phase change heat storage device with folded fins based on bionics, characterized in that: include: Inner tube of shell and tube heat exchanger; An outer tube of a shell and tube heat exchanger, wherein the outer tube cover of the shell and tube heat exchanger is connected to the outer peripheral side of the inner tube of the shell and tube heat exchanger; Phase-change heat storage folded fins, the phase-change heat storage folded fins are arranged in the annular area between the inner tube of the shell and tube heat exchanger and the outer tube of the shell and tube heat exchanger; The phase-change heat storage folded fins include short straight fin segments attached to the outer side of the inner tube of the shell and tube heat exchanger, the short straight fin segments are connected to the short straight fin segments attached to the inner side of the outer tube of the shell and tube heat exchanger through folded fin segments, and the center lines of the short straight fin segments are in the same radial direction; The number of the phase-change heat storage folded fins is set to be a plurality, and the plurality of phase-change heat storage folded fins are evenly distributed circumferentially in the annular region between the inner tube of the shell and tube heat exchanger and the outer tube of the shell and tube heat exchanger; The phase change heat storage folded ribs are set to four pieces, and the angle between two adjacent phase change heat storage folded ribs is 90 degrees; the shape of the phase change heat storage folded ribs is calculated using formula (1) and formula (2): Where: r1 is the outer diameter of the inner tube of the shell and tube heat exchanger; r2 is the inner diameter of the outer tube of the shell and tube heat exchanger; r is the distance from a point on the x-axis to the center of the inner tube, and the value range is r∈[r1, r2]; x is the independent variable; y is the rib position corresponding to the x position.

2. The bionics-based phase change heat storage device with folded fins according to claim 1, characterized in that: The thickness of the phase-change heat storage folded fins ranges from 1 to 2 mm.

3. The bionics-based phase change heat storage device with folded fins according to claim 1, characterized in that: The diameter of the outer tube of the shell and tube heat exchanger is no more than 6 times the diameter of the inner tube of the shell and tube heat exchanger.

4. The bionics-based phase change heat storage device with folded fins according to claim 1, characterized in that: The inner tube of the shell and tube heat exchanger is made of metal material.

5. The bionics-based phase change heat storage device with folded fins according to claim 4, characterized in that: The material of the phase-change heat storage folded fins is the same as the material of the inner tube of the shell and tube heat exchanger.

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