Integrated casting type fin heating module and air heater with same

Abstract

The utility model discloses an integrated casting type fin heating module and an air heater with the same, and the heating module comprises a heating element which is connected to a heating power supply and is of a circular tube structure; the fin assembly is integrally formed on the periphery of the heating element in a casting mode and comprises a plurality of circular fins which are arranged at intervals in the length direction of the heating element, each fin is provided with a plurality of circulation holes, the circulation holes in the adjacent fins are arranged in a staggered mode, and the areas of the circulation holes in each fin are equal; the barrel is arranged on the periphery of the fin assembly, the fins are attached to the inner wall of the barrel, one end of the barrel in the length direction is a fluid inlet, and the other end of the barrel in the length direction is a fluid outlet. According to the heating module and the air heater with the same, the heating efficiency can be improved, and the service life can be prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of heaters, and particularly relates to an integrally cast fin heating module and an air heater with the same Background Art

[0002] Generally, the cold core core-making process needs to be able to quickly, continuously, and stably provide high-temperature compressed air to vaporize the triethylamine liquid. The vaporized triethylamine is mixed with compressed air to catalyze and cure the sand core; the inorganic process also needs to be able to quickly, continuously, and stably provide high-temperature compressed air to catalyze and cure the sand core

[0003] At present, a resistive assembled air heater is usually adopted on the equipment, and its structure adopts a form of inserting heating tubes. During operation, the heating element is energized to heat, and the heat is stored in the metal heat exchanger body inserted and matched with the heating element. Then, the compressed air flows through the heat exchange flow channel on the metal heat exchanger body for heat exchange

[0004] The heater with the above structure has the following defects

[0005] (1) Since the heater is an assembled structure, there is a fitting gap between the heating element and the metal heat exchanger body, and the two are in contact only on discrete area elements. The gaps between the non-contact interfaces are filled with tiny foreign matters such as air, dust, oil stains, and surface oxides, increasing the heat conduction resistance, reducing the heat conduction efficiency, and the tiny foreign matters will also cause surface modification of the heating element and the heat exchanger body, reducing the service life

[0006] (2) A serpentine flow channel is opened on the metal heat exchanger body. On the one hand, the airflow impacts too much at the turning back of the flow channel, resulting in a sharp loss of airflow pressure; on the other hand, the airflow cannot generate effective turbulence in the straight-through channel, and the heat exchange efficiency is low

[0007] (3) The cross-section of the heat exchange flow channel is a rectangular structure, and the temperature field distribution from the heating element to the heat exchanger body is very uneven. Therefore, the temperature distribution on the inner surface of the flow channel is not uniform. Therefore, during the convective heat exchange process of the compressed air in the flow channel, the efficiency is very low

[0008] For heaters with a similar integrally cast structure, the flow channels adopt a form of embedding stainless steel pipes or copper pipes. Although the problem of the fitting gap of the traditional heater is avoided, the stainless steel pipes or copper pipes are commonly arranged in a "U-shaped" or "S-shaped" layout, and their cross-sections still adopt a rectangular layout, and the temperature field distribution is very uneven. Therefore, it is not easy for the compressed air to fully exchange heat with the inner wall of the pipeline, and such heaters are often large in volume and low in heat exchange efficiency Summary of the Utility Model

[0009] Based on the above problems, the purpose of the utility model is to provide an integrally cast fin heating module and an air heater with the same, to improve the heat exchange efficiency and reduce the maintenance cost

[0010] To overcome the deficiencies of the prior art, one of the technical solutions provided by the present utility model is as follows:

[0011] An integrally cast fin heating module, comprising:

[0012] A heating element, which is connected to a heating power supply, and the heating element is in a circular tube structure;

[0013] A fin assembly, which is integrally cast and formed on the outer periphery of the heating element, and includes a plurality of fins that are arranged at intervals along the length direction of the heating element and are circular. A plurality of flow holes are respectively provided on each fin, and the plurality of flow holes on adjacent fins are arranged staggeredly and the areas of the plurality of flow holes on each fin are equal;

[0014] A cylinder body, which is arranged on the outer periphery of the fin assembly, the plurality of fins are in contact with the inner wall of the cylinder body, and one end of the cylinder body in the length direction is a fluid inlet and the other end is a fluid outlet.

[0015] In one embodiment, the fin assembly further includes a seat body provided on the outer periphery of the heating element, and the plurality of fins are integrally formed on the seat body.

[0016] In one embodiment, the thickness of the fin gradually decreases from the root to the top.

[0017] In one embodiment, the inclination angle between the top and the root of the fin is 5-8°.

[0018] In one embodiment, the distance between the roots of adjacent fins is 70-80% of the thickness of the fin top.

[0019] In one embodiment, a reinforcing rib assembly is provided between the plurality of fins and the seat body, and the reinforcing rib assembly includes a plurality of reinforcing ribs arranged along the circumferential direction of the seat body, and the reinforcing ribs extend along the radial direction of the fin.

[0020] In one embodiment, a heat insulation layer is provided between the fin assembly and the inner wall of the cylinder body.

[0021] In one embodiment, a temperature measuring element for measuring temperature is further provided on the cylinder body.

[0022] To solve the above problems, another technical solution provided by the present utility model is as follows:

[0023] An air heater, comprising the heating module described in any one of the above.

[0024] In one embodiment, it includes a plurality of heating modules, a first end cover disposed at one end of the plurality of heating modules, and a second end cover disposed at the other end of the plurality of heating modules. The plurality of heating modules are connected in series and / or in parallel with each other;

[0025] When adjacent heating modules are connected in series, the fluid outlet of one heating module is connected to the fluid inlet of the adjacent heating module;

[0026] When adjacent heating modules are connected in parallel, the fluid inlets of the adjacent heating modules communicate with each other, and the fluid outlets communicate with each other.

[0027] Compared with the prior art, the advantages of the present utility model are:

[0028] 1. The heat exchange component adopts an integral casting process, and the heating element is embedded in the casting body, avoiding the fitting gap between the heating element and the heat exchanger, avoiding the contact thermal resistance caused by the fitting gap, improving the conduction efficiency, avoiding the oxidation modification fatigue problem of the mating surface between the heating element and the heat exchanger, and improving the service life;

[0029] 2. According to the convection equation Q = hAΔT, the heat exchange surface adopts a fin structure, replacing the traditional serpentine groove type or bent tube type air flow channel, increasing the heat exchange area, opening staggered air circulation holes on the fins to have a turbulence effect on the fluid, increasing the contact rate between the fluid and the heat exchange wall surface, so as to increase the value of the heat transfer coefficient h and ultimately improve the heat exchange efficiency;

[0030] 3. The fin assembly adopts a conformal setting coaxial with the heating element, making the temperature field distribution of the heat exchanger more uniform, reducing the power of the heating tube, reducing the size of the components while efficiently improving the heat exchange efficiency;

[0031] 4. The heating element, fin assembly and cylinder body form a heating module, and the heating modules can be connected in series or in parallel according to needs to meet the required target temperature and flow rate. The modules are installed separately, which is convenient for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. The following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 It is a schematic structural diagram of an embodiment of the integral casting type fin heating module of the present utility model;

[0034] Figure 2 It is a schematic structural diagram of the cooperation between the fin assembly and the heating element in the embodiment of the present utility model;

[0035] Figure 3 Schematic diagram of the structure of a fin in an embodiment of the present utility model;

[0036] Figure 4 Schematic diagram of the structure of another fin in an embodiment of the present utility model;

[0037] Figure 5 Schematic diagram of the structure of an air heater in an embodiment of the present utility model;

[0038] Figure 6 Schematic diagram of the structure in which multiple heating modules are connected in series in an embodiment of the present utility model;

[0039] Figure 7 Schematic diagram of the structure in which multiple heating modules are connected in parallel in an embodiment of the present utility model;

[0040] Figure 8 Heat transfer rate curve graph of the air heater in an embodiment of the present utility model and a traditional air heater;

[0041] Figure 9 Output compressed air characteristic diagram of the air heater in an embodiment of the present utility model and a traditional air heater;

[0042] Wherein:

[0043] 1. Heating element;

[0044] 2. Fin assembly; 2-1. Base body; 2-2. Fin; 2-2a. First strip-shaped flow hole; 2-2b. Circular hole; 2-2c. Second strip-shaped flow hole; 2-2d. Third strip-shaped flow hole; 2-3. Reinforcing rib;

[0045] 3. Cylinder;

[0046] 4. Front end cover;

[0047] 5. Rear end cover;

[0048] 6. Heat insulation layer;

[0049] 7. First end cover;

[0050] 8. Second end cover;

[0051] 9. Gland;

[0052] 10. Connecting rod;

[0053] 11. First sealing gasket;

[0054] 12. Bushing;

[0055] 13. Second sealing gasket;

[0056] 14. The third gasket. Specific embodiments

[0057] The above solution will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are for illustrating the present utility model and not for limiting the scope of the present utility model. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0058] See Figure 1 and Figure 2 , which is an integrally cast fin heating module of the present utility model, including a heating element 1, a fin assembly 2 integrally cast on the outer periphery of the heating element 1, and a cylinder 3 arranged on the outer periphery of the fin assembly 2.

[0059] The heating element 1 is connected to a heating power supply, and the heating element 1 has a circular tube structure.

[0060] The fin assembly 2 includes a plurality of fins 2-2 that are arranged at intervals along the length direction of the heating element 1 and are circular. Each fin 2-2 is provided with a plurality of flow holes. The plurality of flow holes on adjacent fins 2-2 are arranged staggeredly, and the areas of the plurality of flow holes on each fin 2-2 are equal. The plurality of flow holes on adjacent fins 2-2 are arranged staggeredly to disturb the fluid flow field, and the equal areas of the plurality of flow holes on each fin 2-2 can ensure the stability of the fluid flow field, thereby ensuring sufficient contact heat transfer between the fluid and the surface of the fin 2-2 and improving the heat transfer efficiency.

[0061] To improve the structural stability, the fin assembly 2 further includes a seat body 2-1 arranged on the outer periphery of the heating element 1. A plurality of fins 2-2 are integrally formed on the seat body 2-1, that is, the seat body 2-1 has a circular tube structure, and a plurality of fins 2-2 are arranged at intervals on the outer wall of the seat body 2-1 and are arranged along the length direction of the seat body 2-1.

[0062] In this example, the cross-section of the fin 2-2 is a regular trapezoid structure, that is, the thickness of the fin 2-2 gradually decreases from the root to the top. Here, the root refers to the part of the fin 2-2 close to the seat body, and the top refers to the part of the fin 2-2 far from the seat body 2-1.

[0063] Preferably, the inclination angle between the top and the root of the fin 2-2 is 5-8°. The fin 2-2 has a structure with a wide root and a narrow top, which is conducive to the heat conduction on the fin 2-2 and ensures uniform temperature distribution on the fin 2-2. The distance between the roots of adjacent fins 2-2 is 70-80% of the thickness of the top of the fin 2-2, so as to balance the contradiction between the fluid flow resistance and the number of fin distributions, ensure sufficient heat transfer, and improve the heat transfer efficiency.

[0064] To further improve the stability of the structure, reinforcing rib assemblies are respectively provided between multiple fins 2-2 and the seat body 2-1. The reinforcing rib assembly includes multiple reinforcing ribs 2-3 arranged circumferentially in the seat body 2-1. Each reinforcing rib 2-3 extends radially along the fin 2-2. The multiple fins 2-2 are interconnected by the reinforcing ribs 2-3. This structure can enhance the rigidity of the fins, enabling them to bear a relatively large fluid pressure.

[0065] In this example, four reinforcing ribs 2-3 are provided between the multiple fins 2-2 and the seat body 2-1. Correspondingly, the multiple flow holes on each fin 2-2 are divided into four sections. The flow holes on adjacent sections are symmetrically arranged. As Figure 3 shown, it is a schematic structural diagram of the flow holes on a fin 2-2. Four flow holes are provided on each section, including two first strip-shaped flow holes 2-2a located in the middle and two circular holes 2-2b located on both sides. The area of the first strip-shaped flow hole 2-2a is larger than that of the circular hole 2-2b.

[0066] As Figure 4 shown, it is a schematic structural diagram of the flow holes on adjacent fins 2-2. Three flow holes are provided on each section, including a second strip-shaped flow hole 2-2c located in the middle and two third strip-shaped flow holes 2-2d located on both sides. The area of the second strip-shaped flow hole 2-2c is larger than that of the third strip-shaped flow hole 2-2d. It should be understood that in other embodiments, the shape and position of the flow holes on each fin 2-2 can be set as needed, as long as the flow holes on adjacent fins 2-2 are staggeredly arranged and the areas of the flow holes are equal.

[0067] The cylinder body 3 is used to cooperate with the fin assembly to form a heating module. The fin assembly 2 is in close contact with the inner wall of the cylinder body 3. A fluid inlet is provided at one end in the length direction of the cylinder body 3 and a fluid outlet is provided at the other end.

[0068] The fluid enters from the fluid inlet of the cylinder body 3, fully exchanges heat with the fin assembly 2, and then is discharged from the fluid outlet, realizing the heating of the fluid.

[0069] To improve the heating efficiency, a heat insulation layer 6 is provided between the fin assembly 2 and the inner wall of the cylinder body 3 to reduce heat dissipation to the outside of the cylinder body 3.

[0070] To facilitate the control of the heating temperature, a temperature measuring element for measuring temperature is provided on the cylinder body 3. The temperature inside the cylinder body 3 is detected by the temperature measuring element. When the temperature reaches a predetermined value, the power supply for heating is stopped.

[0071] The present utility model also discloses an air heater, which includes the above-mentioned heating module. As Figure 1As shown in the figure, it is an air heater including a single heating module, which includes a single heating module. A front end cover 4 is provided at one end of the cylinder body 3, and a rear end cover 5 is provided at the other end of the cylinder body 3. A fluid inlet is provided on the front end cover 4, and a fluid outlet is provided on the rear end cover 5.

[0072] As Figures 5 to 7 shown in the figure, it is another air heater, which includes a plurality of heating modules, a first end cover 7 provided at one end of the plurality of heating modules, and a second end cover 8 provided at the other end of the plurality of heating modules. The number of the plurality of heating modules is nine, and three of them are connected in series with each other to form three series units, and the three series units are connected in parallel with each other. Specifically, the plurality of heating modules in each row are connected in series with each other, and the three column series units are connected in parallel with each other.

[0073] The first end cover 7 is provided with a mounting hole for the heating module to extend into, and a first communication hole is provided in the mounting hole so that adjacent heating modules can be connected in series or in parallel with each other. The heating module is pressed against the first end cover 7 by a gland 9. The second end cover 8 is provided with a mounting groove for the heating module to be placed in, and a second communication hole is provided in the mounting groove so that adjacent heating modules can be connected in series or in parallel with each other.

[0074] In order to improve the sealing performance, a first gasket 11 is respectively provided between the cylinder body 3 and the first end cover 7 and the second top cover 8. A bushing 12 is provided between the gland 9 and the seat body 2-1. A second gasket 13 is provided between the bushing 12 and the gland 9, and a third gasket 14 is provided between the bushing 12 and the seat body 2-1.

[0075] This air heater is tested and compared with a traditional assembled air heater. As Figure 8 shown in the figure, under the same input conditions, the heat transfer rate is significantly improved compared with the traditional heater. As Figure 9 shown in the figure, according to the output characteristics of the compressed air, the maximum temperature response time is advanced by about 170 s, which will greatly improve the core-making efficiency. Under the test conditions of the body temperature of 200 °C and the compressed air flow rate of 800 L / min, the measured comprehensive heat transfer efficiency is increased from the original 30% - 35% to 72% - 84%.

[0076] As Figure 6 shown in the figure, when adjacent heating modules are connected in series with each other, the fluid outlet of one heating module is connected to the fluid outlet of the adjacent heating module; as Figure 7 shown in the figure, when adjacent heating modules are connected in parallel with each other, the fluid inlets of the adjacent heating modules are connected to each other, and the fluid outlets are connected to each other. In this way, when the heating modules are connected in series with each other, the requirements for different heating temperatures can be met, and when the heating modules are connected in parallel with each other, the requirements for different flow rates can be met.

[0077] In order to improve the structural stability, a plurality of connecting rods 10 are also connected between the first end cover 7 and the second end cover 8.

[0078] In summary, the heating module can improve the heat exchange efficiency, extend the service life, and can be used in series or parallel to meet different target temperatures and flow rates.

[0079] The above examples are only for illustrating the technical concept and features of the present invention. The purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and it should not be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. One-piece cast fin heating module, characterized in that: include: A heating element connected to a heating power source, wherein the heating element is a circular tubular structure; A fin assembly is integrally cast on the periphery of the heating element, comprising a plurality of circular fins arranged at intervals along the length direction of the heating element, each of the fins is provided with a plurality of flow holes, the plurality of flow holes on adjacent fins are arranged in a staggered manner, and the areas of the plurality of flow holes on each fin are equal; The cylinder is arranged at the periphery of the fin assembly, the multiple fins are in contact with the inner wall of the cylinder, one end of the cylinder in the length direction is a fluid inlet and the other end is a fluid outlet.

2. The integrally cast fin heating module according to claim 1, characterized in that: The fin assembly further comprises a seat body arranged at the periphery of the heating element, and the plurality of fins are integrally formed on the seat body.

3. The integrally cast fin heating module according to claim 2, characterized in that: The thickness of the fin gradually decreases from the root to the top.

4. The integrally cast fin heating module according to claim 2, characterized in that: The inclination angle between the top and the root of the fin is 5-8°.

5. The integrally cast fin heating module according to claim 2, characterized in that: The spacing between adjacent fin roots is 70-80% of the thickness of the fin top.

6. The integrally cast fin heating module according to claim 5, characterized in that: A reinforcing rib assembly is provided between the plurality of fins and the seat body, wherein the reinforcing rib assembly comprises a plurality of reinforcing ribs arranged along the circumference of the seat body, and the reinforcing ribs extend radially along the fins.

7. The integrally cast fin heating module according to claim 1, characterized in that: A heat-insulating layer is provided between the fin assembly and the inner wall of the cylinder.

8. The integrally cast fin heating module according to claim 1, characterized in that: The cylinder is also provided with a temperature measuring element for measuring temperature.

9. Air heater, characterized in that: A heating module comprising any one of claims 1 to 8.

10. The air heater according to claim 9, characterized in that: It comprises a plurality of heating modules, a first end cap arranged at one end of the plurality of heating modules and a second end cap arranged at the other end of the plurality of heating modules, and the plurality of heating modules are connected in series and / or in parallel with each other; When adjacent heating modules are connected in series, the fluid outlet of one heating module is connected to the fluid inlet of an adjacent heating module; When adjacent heating modules are connected in parallel, the fluid inlets of the adjacent heating modules are connected to each other, and the fluid outlets of the adjacent heating modules are connected to each other.

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