CN201093913Y

CN201093913Y - Strengthened heat exchanging device

Info

Publication number: CN201093913Y
Application number: CNU2007201732229U
Authority: CN
Inventors: 苏生; 刘建军; 安柏涛; 胡捷
Original assignee: Institute of Engineering Thermophysics of CAS
Current assignee: Institute of Engineering Thermophysics of CAS
Priority date: 2007-09-19
Filing date: 2007-09-19
Publication date: 2008-07-30
Anticipated expiration: 2017-09-19

Abstract

The utility model relates to a reinforced heat exchanging device having periodically alternating ribs internally. Based on the channel of periodically alternating ribs, a small rib is arranged between every two big ribs and is situated in the position close to the downstream big rib between two big ribs. The big and small ribs are parallel on the same wall. The structure of the periodically alternating ribs of the utility model has comparatively high overall coefficient of heat transfer and low flow resistance. The integrated heat transferring performance is largely improved compared with the structure of big ribs of single dimension.

Description

Reinforced heat exchanger

Technical field

The utility model relates to a kind of inside and has the reinforced heat exchanger that periodically replaces big or small fin, and its structure is to settle a little fin between per two big fins, and the position of little fin is close big fin place, downstream between two big fins.

Background technology

Fin is widely used in the inner enhanced heat exchange passage, by settling the mode of fin can increase heat exchange area and play the flow-disturbing effect at heat exchange surface, the heat exchange effect is strengthened.The inner rib channel application is in the heat exchange of gas turbine working-blade the time, usually adopt the straight rib angled (cross section can be rectangle, triangle and circle) of periodic arrangement with the air current flow direction, because the channel design with ribbing of this form is simple, be easy to processing and manufacturing, and have enhanced heat exchange effect preferably.By contrast, also have many novel rib structures also to have good enhanced heat exchange effect, as the discrete rib of different shape etc., but when adopting these fins, blade construction can relative complex, is difficult for making.

The utility model content

The purpose of this utility model provides a kind of reinforced heat exchanger, it is the inner rib passage with good enhanced heat exchange performance, this passage all is being better than the inner passage that adopts periodic single fin aspect exchange capability of heat and the flow resistance, and this passage is easy to make.

For achieving the above object, technical solution of the present utility model is:

A kind of reinforced heat exchanger is used for the fluid convection heat exchange; It has in the passage of periodicity fin in inside, and the little fin of a height less than former fin is set between former two fins, forms the big or small rib structure that one-period property replaces on main heat exchange wall.

Described reinforced heat exchanger, the direction of principal axis unanimity of its large and small fin is parallel to each other; The height of little fin is between 0.3～0.5 times of big fin.

Near big fin place, downstream, when the spacing between the adjacent big fin of phasing was p according to appointment, then little fin was arranged in the position between big fin downstream 0.6p～0.8p between two big fins for described reinforced heat exchanger, its described little fin.

The beneficial effects of the utility model are that among the comprehensive heat exchange evaluation criterion of employing, the comprehensive heat exchange property that replaces big or small rib structure of the present utility model obviously is better than single big rib structure.In addition, it is simple to make the technology that replaces big or small rib structure, and difficulty is lower, and is suitable with single big rib structure, all is easy to make.

Description of drawings

Fig. 1 is the heat exchange wall schematic diagram that adopts the passage with ribbing of single size fin;

Fig. 2 is the flow schematic diagram of air-flow under the effect of fin flow-disturbing;

Fig. 3 is the utility model: replace big or small fin heat exchange structure figure;

Fig. 4 is the heat transfer coefficients distribution figure that has single big fin channel wall;

Fig. 5 adopts the heat transfer coefficients distribution figure that replaces big or small fin channel wall.

The specific embodiment

The utility model reinforced heat exchanger adopts inside to replace big or small rib structure.In the big fin passage of periodic arrangement, big fin height e is between 0.05D～0.1D, and the ratio of spacing of fins p and fin height e is between 7～15, and D is the passage hydraulic diameter.On the basis of big fin passage, between per two big fins, arrange little fin, the height of little fin is between 0.3e～0.5e, and little fin is big fin one end in close downstream between two big fins, and the distance of the big fin in downstream is between 0.2p～0.4p.

In the structure that adopts single big fin, when air flow stream is crossed fin, all can produce backflow (front step refluxes and backward step refluxes in the fin upstream and downstream, as shown in Figure 2), air-flow can adhere to again after the backward step in fin downstream refluxes, the coefficient of heat transfer of the shock zone that when adhering to again wall is formed is very high (as shown in Figure 4, wherein A is for impacting the high coefficient of heat transfer zone that produces), and this high coefficient of heat transfer zone extends near next-door neighbour's the upstream of front step backflow position of next fin always, has the coefficient of heat transfer of recirculation zone lower.Add after the little fin, the exchange capability of heat of big fin front step recirculation zone is improved (as shown in Figure 5, wherein B, C are for impacting the high coefficient of heat transfer zone that produces), little fin is when increasing passage effective heat exchange area with ribbing, cross the effect that the big fin in downstream plays a transition for air flow stream, the flow resistance of air-flow in whole passage reduced to some extent.

Below in conjunction with the drawings and specific embodiments the utility model is described in further detail:

Fig. 1 inside has in the passage of single size fin, and typical fin height is between 0.05D～0.1D, and p/e is between 7～15.

Form front step in the fin upstream among Fig. 2 and reflux, this zone has the lower coefficient of heat transfer, and gas shock has the bigger pressure loss during to the fin leading edge.

Be position between 0.6～0.8 at p2/p1 among Fig. 3, near the promptly big fin front step recirculation zone, add little fin (height of little fin is between 0.3～0.5 times of big fin).

Fig. 4, Fig. 5 are a certain Reynolds number condition lower channel wall heat transfer coefficients distribution, the number range that two figure adopt is identical, as can be seen, adopt after the big or small rib structure, the exchange capability of heat of big fin front step recirculation zone strengthens to some extent, impact the high coefficient of heat transfer zone that wall forms when not only having kept big fin downstream to adhere to again, and occurred the C zone of the high coefficient of heat transfer in the lower big fin front step recirculation zone of the script coefficient of heat transfer by air-flow.In addition, on flowing, little fin plays the effect of guiding, transition, and flow resistance is reduced to some extent.

According to multiple strengthening heat exchange evaluation criterion η=(Nu/Nu _s)/(C _f/ Cf _s) ^1/3, of the present utility modelly replace big or small rib structure the heat exchange property of passage be improved.

The utility model is not limited to above-mentioned side chamber passage enhanced heat exchange wall; be equally applicable to the enhanced heat exchange wall of pipe, board-like or other shapes; as long as the little fin of periodic arrangement all belongs to the scope that the utility model claim is protected between periodic fin.

Claims

1. reinforced heat exchanger, be used for the fluid convection heat exchange, it is characterized in that: have in the passage of periodicity fin in inside, the little fin of a height less than former fin is set between former two fins, on the heat exchange wall, form the big or small rib structure that periodically replaces.

2. reinforced heat exchanger according to claim 1 is characterized in that: the direction of principal axis unanimity of large and small fin is parallel to each other; The height of little fin is between 0.3～0.5 times of big fin; Little fin is close big fin place, downstream between two big fins.

3. reinforced heat exchanger according to claim 2, it is characterized in that: described little fin is close big fin place, downstream between two big fins, when the spacing between the adjacent big fin of phasing was p according to appointment, then little fin was arranged in the position between big fin downstream 0.6p～0.8p.