CN110849201A

CN110849201A - Hall effect-based enhanced heat exchange method under special working condition

Info

Publication number: CN110849201A
Application number: CN201910984056.8A
Authority: CN
Inventors: 王建强; 杨建刚
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2020-02-28
Anticipated expiration: 2039-10-16
Also published as: CN110849201B

Abstract

The invention provides a Hall effect-based enhanced heat exchange method under special working conditions, which is characterized in that an external electric field and a magnetic field are additionally arranged according to a main heat transfer mechanism of metal, namely a current carrier is used as a main heat-conducting medium, the characteristic of the Hall effect on the change of the flow direction of the current carrier is utilized, so that the circulation interaction of the current carrier between a cold source and a heat source is realized, and finally, the function of performing forced heat exchange by using the current carrier as the heat-conducting medium is realized. Compared with the prior art, the invention has the beneficial effects that: the invention provides active heat transfer enhancement aiming at the condition that the conventional heat transfer enhancement technology is difficult to be applied in the working condition of an extreme high-temperature environment and aiming at relieving the high-temperature performance required by a metal material; finally, the metal temperature under the working conditions can be reduced, so that the high-temperature pressure resistance of the metal material is relieved, the working condition safety and stability of the metal material are enhanced, and meanwhile, the high-temperature creep of the metal material can be relieved and the service life of the metal material can be prolonged through proper control.

Description

Hall effect-based enhanced heat exchange method under special working condition

Technical Field

The invention relates to the field of heat transfer enhancement under special working conditions, in particular to a heat transfer enhancement method based on a Hall effect under special working conditions.

Background

The existing heat exchange enhancement modes can be mainly divided into three types: increase heat transfer area, increase heat transfer temperature difference and improve heat transfer coefficient. The method for increasing the heat transfer area is mainly to add fins and the like. The improvement of heat transfer coefficient is the main research direction at present, and the improvement can be divided into active strengthening and passive strengthening. The passive reinforcement is to use the structures such as spiral groove pipes, transverse groove pipes, corrugated pipes and the like to break the flow boundary layer so as to achieve the purpose of improving the surface heat transfer coefficient. Active enhancement is to improve the surface heat transfer coefficient by using mechanical stirring, surface vibration, fluid vibration, spraying or sucking, and the like. Increasing the heat transfer temperature difference is not commonly used due to economic, safety, etc. However, the technology is only well applied under the conventional working conditions, and is still deficient in extremely severe environmental working conditions, such as the high-temperature working condition environment of an aircraft engine. At present, the common technical idea for the extremely severe environmental conditions is to manufacture high-temperature refractory materials, but the research and development and application of the materials still need to be promoted. The invention provides a solution for the extreme high temperature environment.

The starting angle of the invention is that the heat transfer of the current carrier is realized by an active mode and by utilizing the current carrier to carry out forced heat exchange according to a metal heat transfer mechanism, namely, a vertical electric field and a magnetic field are arranged in a metal material, and the characteristic that the moving charge turns in the magnetic field is utilized.

Disclosure of Invention

The technical problem is as follows: the invention mainly aims at the heat exchange problem in an extreme high temperature environment, and provides a solution idea with lower cost, namely active carrier forced heat exchange based on Hall effect, because the working condition of the extreme high temperature environment has the characteristics of extremely high instantaneous heat productivity, complex mechanical working condition, extremely high safety and stability requirements and the like, the conventional intensified heat exchange technology is difficult to apply, and the research and development application cost of refractory materials is extremely high.

The technical scheme is as follows:

according to the invention, according to the main heat transfer mechanism of metal, namely, a current carrier is used as a main heat-conducting medium, and the characteristic that the flow direction of the current carrier is changed by utilizing the Hall effect is utilized, an external electric field and a magnetic field are additionally arranged for realizing the circulation interaction of the current carrier between a cold source and a heat source, and finally, the function of performing forced heat exchange by using the current carrier as the heat-conducting medium is realized.

When the current carrier is a metal flat plate, an electric field and a magnetic field which are perpendicular to each other are added to the metal flat plate, the direction of the electric field is horizontal to the right, the direction of the magnetic field is perpendicular to the metal flat plate to the outside, electrons move to the left under the action of the external electric field, the movement direction of the electrons is deflected under the action of the external magnetic field, the electrons move downwards and are deflected, then the electrons pass through a backflow guide path to the high-temperature fluid side, a semi-closed loop is formed, and heat is carried to the low-temperature side from the high-temperature side to be cooled in the movement process of the electrons.

When the current carrier is a turbine blade grid, electrons move against the direction of an electric field under the action of the electric field, the electrons deviate under the action of a magnetic field in a blade grid root accessory area, then move towards the top of the blade grid, under the action of an external voltage, the electrons break through gaps to an inner shell loop, then the electrons are led to a cold source through other loops to be cooled, and then closed loops are achieved, and the electrons carry heat at the blade grid accessories to the cold source to be cooled.

Has the advantages that: the invention provides active heat transfer enhancement aiming at the condition that the conventional heat transfer enhancement technology is difficult to be applied in the working condition of an extreme high-temperature environment and aiming at relieving the high-temperature performance required by a metal material; finally, the metal temperature under the working conditions can be reduced, so that the high-temperature pressure resistance of the metal material is relieved, the working condition safety and stability of the metal material are enhanced, and meanwhile, the high-temperature creep of the metal material can be relieved and the service life of the metal material can be prolonged through proper control.

Drawings

FIG. 1 is a schematic view of example 1 of the present invention.

FIG. 2 is a schematic view of example 2 of the present invention.

In fig. 2, arrows indicate electric field directions, and dots indicate magnetic field directions.

Detailed Description

The present invention will be further illustrated with reference to the accompanying drawings and specific embodiments, which are to be understood as merely illustrative of the invention and not as limiting the scope of the invention. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

Example 1

As shown in figure 1, in the heat exchange application of the metal plate, an electric field and a magnetic field which are perpendicular to each other are added to the metal plate, the direction of the electric field is horizontal to the right in figure 1, the direction of the magnetic field is perpendicular to the metal plate to the outside, electrons move to the left under the action of the added electric field, the Hall effect shows that the direction of the movement of the electrons deflects under the action of the added magnetic field, the electrons deflect downwards under the condition of figure 1 and then pass through a backflow guide path to the side of a high-temperature fluid to form a semi-closed loop, heat is carried from the high-temperature side to the low-temperature side to be cooled in the process of the movement of the electrons, and then forced heat exchange is realized.

Example 2

As shown in fig. 2, in the heat exchange application of the turbine blade cascade, under the action of an electric field, electrons move against the direction of the electric field, the region near the root of the blade cascade is subjected to the action of a magnetic field to generate deviation, and then move to the top of the blade cascade to reduce the clearance as much as possible while meeting the requirement of mechanical motion characteristics.

The technical means disclosed in the invention scheme are not limited to the technical means disclosed in the above embodiments, but also include the technical scheme formed by any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.

Claims

1. A heat exchange enhancement method based on a Hall effect under a special working condition is characterized by comprising the following steps: an external electric field and a magnetic field are added to the current carrier.

2. The Hall effect-based enhanced heat exchange method under special working conditions according to claim 1, characterized in that: when the current carrier is a metal flat plate, an electric field and a magnetic field which are perpendicular to each other are added to the metal flat plate, the direction of the electric field is horizontal to the right, the direction of the magnetic field is perpendicular to the metal flat plate to the outside, electrons move to the left under the action of the external electric field, the movement direction of the electrons is deflected under the action of the external magnetic field, the electrons move downwards and are deflected, then the electrons pass through a backflow guide path to the high-temperature fluid side, a semi-closed loop is formed, and heat is carried to the low-temperature side from the high-temperature side to be cooled in the movement process of the electrons.

3. The Hall effect-based enhanced heat exchange method under special working conditions according to claim 1, characterized in that: when the current carrier is a turbine blade grid, electrons move against the direction of an electric field under the action of the electric field, the electrons deviate under the action of a magnetic field in a blade grid root accessory area, then move towards the top of the blade grid, under the action of an external voltage, the electrons break through gaps to an inner shell loop, then the electrons are led to a cold source through other loops to be cooled, and then closed loops are achieved, and the electrons carry heat at the blade grid accessories to the cold source to be cooled.