CN205679109U - A kind of New High-Efficient Fractal fin for plate-fin heat exchanger - Google Patents

Abstract

This utility model is applicable to field of heat exchange equipment, it is provided that a kind of novel fractal fin created based on three points of G.Cantor set；Being made up of N rank (N 2) spaced plain fin section, the length of the plain fin section on adjacent two rank is constantly reduced, and the number of fin is on the increase and the spacing distance of adjacent two rank fins is identical.First rank fin is made up of one section of plain fin.The length of each N rank plain fin section is the 1/3 of each N 1 rank plain fin segment length, and the number of N rank plain fin section is 2 times of N 1 rank plain fin section number.This utility model promotes the mixing of fluid, decreases whirlpool dead area, enhances the convection heat transfer' heat-transfer by convection process between air and fin, thus improves the heat exchange property of heat exchanger.Further, this utility model simple in construction, easy to manufacture, production cost is relatively low, practical.

Description

A kind of New High-Efficient Fractal fin for plate-fin heat exchanger

Technical field

This utility model belongs to field of heat exchangers, particularly relates to a kind of New High-Efficient Fractal wing for plate-fin heat exchanger Sheet

Background technology

Plate-fin heat exchanger is as a kind of efficient, compact, light and handy heat transmission equipment at present, in petrochemical industry, aviation boat My god, electronics, the field such as metallurgical and mechanical be used widely, and utilizing heat energy, recovery waste heat, economizing in raw materials, reduce cost And in some specific uses, achieve significant economic benefit.Plate-fin heat exchanger is one of heat transmission equipment of high-efficiency compact, Its main heat transfer element is the fin between plate, and conventional fin configuration mainly has: plain fin, saw tooth fin, corrugated fin, hundred Leaf window fin, slitted fin etc..Along with the progressively expansion of plate-fin heat exchanger range of application, fin performance is proposed higher Requirement, the demand of exploitation Novel fin is more and more urgent.

Utility model content

The purpose of this utility model is to provide a kind of New High-Efficient Fractal fin for plate-fin heat exchanger, it is intended to solve The certainly existing problem that finned heat exchanger heat exchange efficiency is low, air-side blockage is big.

For achieving the above object, the utility model proposes a kind of New High-Efficient Fractal fin for plate-fin heat exchanger, Including the plain fin section of N rank (N 2) spaced and parallel arrangement, the length of the plain fin section on adjacent two rank is constantly reduced, fin Number be on the increase and the spacing distance of adjacent two rank fins is identical；First rank fin is made up of one section of plain fin；Each The length of N rank plain fin section is the 1/3 of each N-1 rank plain fin segment length, and the number of N rank plain fin section is 2 times of N-1 rank plain fin section number.

The starting point of described N rank plain fin section is hung down with the starting point line of N-1 rank plain fin section and N-1 rank fin Directly, the line at the starting point of another plain fin section of N rank and the 2/3 of N-1 rank plain fin section and N-1 rank plain fin Duan Chuizhi；And the centrage of plain fin Duan Yi 1 rank, N rank plain fin section is symmetrical arranged.

The technical solution of the utility model be achieved in that (1) design two kinds of parted saw tooth type fins, i.e. I fin and II fin；(2) three points of G.Cantor set are utilized to create fractal flat type fin, i.e. III fin and IV fin；(3) fractal fin is set up Laminar flow, turbulence model, and utilize fluent software to carry out numerical simulation, its result is contrasted with plate fin, studies it Flowing and heat transfer property；(4) result drawn according to the 3rd step, sets up the three-dimensional large eddy simulation mould of more excellent fin and plate fin Type also carries out numerical simulation, the heat exchange amount relation over time of research fin, and com-parison and analysis draws optimum fin structure.

This utility model utilizes three points of G.Cantor set to develop a kind of fractal flat type fin, when air enters fractal fin region During territory, continuously forming of air thermal boundary layer in flat substrate has been interrupted at the interval between fin section, is thinned thermal boundary Layer；Meanwhile, have cold air to enter at spacer segment, promote the mixing of fluid, decrease whirlpool dead area, enhance air with Convection heat transfer' heat-transfer by convection process between fin, thus improve the heat exchange property of heat exchanger.

Accompanying drawing explanation

Fig. 1 is the structural upright schematic diagram of this utility model that is 2 rank fractal flat type fin；

1. plain fin section, the 2. starting point of plain fin section.

Fig. 2 is the structural upright schematic diagram of I fin that is 1 rank parted saw tooth type fin；

Fig. 3 is the structural upright schematic diagram of II fin that is 2 rank parted saw tooth type fin；

Fig. 4 is the structural upright schematic diagram of III fin that is 1 rank fractal flat type fin；

Fig. 5 is the relation curve of five kinds of fin unit pressure drop heat exchange amounts and inlet velocity；

Fig. 6 is that the nusselt number of five kinds of fins is with change in pressure drop curve；

Fig. 7 is that the heat exchange amount of II fin, IV fin and plate fin changes over curve.

Detailed description of the invention

In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with accompanying drawing and enforcement Example, is further elaborated to this utility model.Should be appreciated that specific embodiment described herein is only in order to explain This utility model, is not used to limit this utility model.

Fig. 1 shows the structural representation of the fractal fin that this utility model embodiment provides.Fig. 2 is that I fin that is 1 rank are divided The structural upright schematic diagram of shape serrated fin；Fig. 3 is the structural upright schematic diagram of II fin that is 2 rank parted saw tooth type fin； Fig. 4 is the structural upright schematic diagram of III fin that is 1 rank fractal flat type fin；For convenience of description, illustrate only and this reality By the relevant part of new embodiment.

A kind of New High-Efficient Fractal fin for plate-fin heat exchanger, by N rank spaced plain fin section 1 group Becoming, the length of the plain fin section on adjacent two rank is constantly reduced, and the number of fin is on the increase and the interval of adjacent two rank fins Apart from identical.First rank fin is made up of one section of plain fin.The length of each N rank plain fin section is each N-1 rank The 1/3 of plain fin segment length, the number of N rank plain fin section is 2 times of N-1 rank plain fin section number.N rank The starting point 2 of plain fin section is vertical with N-1 rank fin with the starting point line of N-1 rank plain fin section, and another is straight on N rank The starting point of fin section is vertical with N-1 rank plain fin section with the line at the 2/3 of N-1 rank plain fin section 1；And N rank are flat The centrage of straight fins Duan Yi 1 rank plain fin section is symmetrical arranged.

When air enters fractal fin area, air has been interrupted in flat substrate in the interval between plain fin section 1 The continuously forming of thermal boundary layer, be thinned thermal boundary layer；Meanwhile, there is cold air to enter at spacer segment, promote fluid Mixing, decreases whirlpool dead area, enhances the convection heat transfer' heat-transfer by convection process between air and fin, thus improve the heat exchange of heat exchanger Performance.

By using numerical simulation technology, respectively general plate fin and four kinds of fractal fins heat transfer and resistance are carried out Calculating, be concluded that

Fig. 5 is the relation curve of five kinds of fin unit pressure drop heat exchange amounts and inlet velocity.Plate fin therein refers to The fin of existing only one layer heat radiation flat board.As seen from the figure, along with the increase of entrance velocity, the unit pressure drop of five kinds of fins Heat exchange amount is gradually reduced.Wherein, the heat exchange amount of I fin unit pressure drop is minimum, illustrates that its heat-transfer effect is worst；III fin and IV wing The heat exchange amount of sheet unit pressure drop is all higher than plate fin, and is respectively 3.2%～8.3% He relative to the increment of plate fin 12.4%～22.9%.

Fig. 6 is that the nusselt number of five kinds of fins is with change in pressure drop curve.Plate fin therein refer to existing only The fin of one layer of heat radiation flat board.As seen from the figure, along with the increase of pressure drop, the nusselt number of five kinds of fins is gradually increased.Work as pressure drop Time identical, the nusselt number of II, III, IV fin is all higher than plate fin, and wherein, the nusselt number of IV fin is maximum, relatively 5.5%-71.5% is improve in plate fin.

Fig. 7 is that the heat exchange amount of II fin, IV fin and plate fin changes over curve.Plate fin therein refers to It it is the fin of existing only one layer heat radiation flat board.As seen from the figure, increase over time, the heat exchange amount of IV fin always greater than The heat exchange amount of II fin and plate fin.

By above-mentioned analysis, the complex heat transfer performance of IV fin that is 2 rank fractal flat type fin is best, can be as excellent Change result.Relative to existing ordinary flat fin, the fractal plain fin after optimization can strengthen heat-transfer capability effectively, thus Reduce cost.

The foregoing is only preferred embodiment of the present utility model, not in order to limit this utility model, all at this Any amendment, equivalent and the improvement etc. made within the spirit of utility model and principle, should be included in this utility model Protection domain within.

Claims (2)

1. the New High-Efficient Fractal fin for plate-fin heat exchanger, it is characterised in that: include the spaced and parallel arrangement in N rank Plain fin section, wherein N 2, the length of the plain fin section on adjacent two rank constantly reduces, and the number of fin is on the increase and phase The spacing distance of adjacent two rank fins is identical；First rank fin is made up of one section of plain fin；The length of each N rank plain fin section Degree is the 1/3 of each N-1 rank plain fin segment length, and the number of N rank plain fin section is N-1 rank plain fin section 2 times of number.

New High-Efficient Fractal fin the most according to claim 1, it is characterised in that: rising of described N rank plain fin section Select vertical with N-1 rank fin with the starting point line of N-1 rank plain fin section, the starting point of another plain fin section of N rank with Line at the 2/3 of N-1 rank plain fin section is vertical with N-1 rank plain fin section；And plain fin Duan Yi 1 rank, N rank The centrage of plain fin section is symmetrical arranged.