CN101399311A

CN101399311A - Thermoelectric element

Info

Publication number: CN101399311A
Application number: CNA2008101685284A
Authority: CN
Inventors: 胡修泰
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-10
Filing date: 2008-12-10
Publication date: 2009-04-01

Abstract

The invention relates to an element for direct thermal power generation, the element avoids the use of a steam-driven turbine machine and is particularly applicable to warm water power generation, thereby having high efficiency and low cost. The element is mainly characterized in that: the element comprises a thermal deformation tube and a plurality of piezoelectric materials, when the thermal deformation tube is heated, the volume is increased, when the thermal deformation tube is cooled, the volume is reduced; the piezoelectric materials are overlapped in the thermal deformation tube layer by layer; and the power generation process is as follows: when the thermal deformation tube is expanded by heating, the tension is formed on the piezoelectric materials (when in the presence of pre-pressure, the pressure is reduced), the current with a certain polarity (such as positive pole) is output; when the thermal deformation tube is contracted by cooling, the pressure is formed on the piezoelectric materials (when in the presence of pre-pressure, the pressure is increased), and the current with the reverse polarity is output. The element has the advantages that: the element leads the thermal power generation to have low cost and high efficiency and causes the low temperature power generation to be possible.

Description

Thermoelectric element

Technical field under the claimed technical scheme:

The present invention relates to a kind of element that is used for the heating power direct generation of electricity, avoid using the steam driven turbine, be specially adapted to the warm water generating.

Affiliated technical field background:

As everyone knows, present thermal power plant is that medium (water) is added the thermosetting high steam, drives the turbogenerator generating.The cost height must be extensive, just is of practical significance.

In recent years, people have invented alkali metal thermal power generation technology, are used for the generating of warm power, and the heat extraction temperature but can not be used for the low temperature thermal power generation about 300 ℃.The temperature generating did not form commercial climate at present yet during alkali metal thermal power generation technology promptly was used in.

And the demand of low temperature thermal power generation is very extensive, and particularly the cryogenic conditions of thermal source can be found everywhere below 100 ℃, does not have relevant art to be used and is wasted in a large number but suffer from.As solar heat, engine water tank waste heat, engine exhaust heat, equipment heat, light fixture heat, steel plant's waste heat, power plant waste heat, chemical plant waste heat, cement plant waste heat, underground heat, heating etc.Remote districts obtain electric power with life heat, also will have prospect.Utilize the system or the cost of these waste heats very high at present, or do not exist.

Summary of the invention:

The present invention is the thermal power generation element that a kind of efficient cheapness will be provided, and avoids using steam turbine.

The present invention is characterized in:

This element comprises thermal deformation pipe and plurality of piezoelectric materials, and volume increased when the thermal deformation pipe was heated, and volume reduces during cooling;

Described piezoelectric successively is stacked in the thermal deformation pipe;

Power generation process is: during thermal deformation pipe expanded by heating, forming tension force (when having precompression, pressure reduces) on the piezoelectric, exporting certain polarity electric current of (as just);

When the cooling of thermal deformation pipe is shunk, forming pressure (when having precompression, pressure increases), output and above-mentioned opposite polarity electric current on the piezoelectric.

Basic principle of the present invention as shown in Figure 1.1 is pipe end-cap among the figure; 2 is the thermal deformation pipe, and its material can be each metalloid, and as aluminium alloy etc., the powerful shutoff of end cap is used at the two ends of thermal deformation pipe; 3 is piezoelectric.Fig. 1 only pays attention to the axial stretching of thermal deformation pipe, and the radial expansion of thermal deformation pipe also is utilizable, therefore can improve thermoelectrical efficiency.Simultaneously, negligible axial is flexible fully also is fine, and only uses radial expansion, and at this moment the end cap of thermal deformation pipe just can omit.

Can suppose that the thermal deformation pipe directly is heated or cools off and shrink, and the free scale of piezoelectric is relatively stable.When the thermal deformation pipe is heated, must expand, make each piezoelectric be subjected to tension force (pressure reduces when having precompression), the electric current of a direction of output.During the cooling of thermal deformation pipe, must shrink, piezoelectric is under pressure, export the electric current of another direction.In fact the temperature of piezoelectric also may slightly change, but the coefficient of linear expansion of piezoelectric is roughly at 5～8E-6, and the coefficient of linear expansion of common iron is about 1.1～1.5E-5, be about 2 times of piezoelectric, about the coefficient of linear expansion 2.4E-5 of aluminium alloy, be about 3 times of pottery, so suppose relatively stable establishment of free scale of piezoelectric.

In order to avoid piezoelectric patches to stretch fully because of variations in temperature, cause reducing thermoelectrical efficiency, can between the periphery of thermal deformation pipe and piezoelectric patches, heat-insulating material be set, as adiabatic membrane etc.

Strictly speaking, the piezoelectric in the thermal deformation pipe can be made long piezoelectrics, and promptly the quantity of piezoelectric is 1.But such design makes output voltage very high (more than 100000V), and electric current very little (below 20uA) deals with difficulty relatively, and the production of piezoelectric simultaneously is also inconvenient.So should the less piezoelectric patches of used thickness.If but many piezoelectric patches all are together in series, make its electric polarization direction all identical, output performance does not at this moment have difference with using long piezoelectrics.

The way that addresses this problem is exactly that the electric polarization direction of all piezoelectric patches is opposite in twos, and promptly the electric polarization direction of adjacent piezoelectric patches is opposite, and with all anodal connections of piezoelectric patches, all negative poles of piezoelectric patches also are communicated with, at last output then.As shown in Figure 2, piezoelectric patches is all series connection on mechanics, and all in parallel on electricity, make output voltage reduce (near 300V) at double, and output current significantly improve (near 500mA), make that the subsequent treatment of system is very convenient.Certainly do not get rid of other various topologys of using series-parallel connection, to adapt to different input/output conditions.Can allow the negative pole of piezoelectric patches directly be communicated with, can also simplify insulation work with the metal of thermal deformation pipe.With the piezoelectric patches chamfering, prevent electrode and thermal deformation tube short circuit.

If between the periphery of thermal deformation pipe and piezoelectric patches, do not stay the gap, the material of rigidity perhaps is set, promptly closely cooperate, with making full use of the radial expansion of thermal deformation pipe, can improve thermoelectrical efficiency.Can form tension force to piezoelectric patches in the piezoelectric patches periphery during thermal deformation tube swelling, when the thermal deformation pipe shrinks, can form pressure to piezoelectric patches in the piezoelectric patches periphery, the effect that their form with axial for superposeing.

Realize extensive generating, will use a plurality of thermoelectric elements simultaneously.In the system that a plurality of thermoelectric sheets are formed, for load of balance thermal source and low-temperature receiver load, just should allow these thermoelectric element alternatelies, dispersedly with thermal source and low-temperature receiver generation heat exchange.

Fig. 3 is a kind of thermal power generation device, and 4～11 is 8 thermoelectric elements among the figure, and they all are supported in the rotating shaft 14; 12 is fan, assists thermoelectric element to cool off fast; 13 is dividing plate, is the normal temperature and pressure atmosphere on the dividing plate, and dividing plate is normal pressure warm water 15 down.This device is had an appointment 3 thermoelectric elements in warm water 15 the insides, accepts heating, and 3 thermoelectric elements of also having an appointment are cooled in normal temperature atmosphere the inside.Rotate the electric current that 14,8 thermoelectric elements send opposed polarity and phase place in turn.This device is applicable to the warm water generating.

Beneficial effect:

The invention has the beneficial effects as follows: make the thermal power generation cost low, the efficient height; And make low-temperature electricity-generating become possibility.

The drawing explanation:

Fig. 1 is a basic principle schematic of the present invention.

Fig. 2 is a kind of electric polarization of piezoelectric patches preferably direction schematic diagram.

Fig. 3 is for using the principle schematic of warm water generating.

Fig. 4 is an optimum implementation of the present invention.

Optimum implementation:

Optimum implementation of the present invention is for as shown in Figure 4.1 is the nut end cap among the figure; 2 is the thermal deformation pipe, and its material is an aluminium alloy, and the nut shutoff is used at the two ends of thermal deformation pipe, and makes the inner waterproofing of thermal deformation pipe; 3 is piezoelectric; 16 is adiabatic membrane.Piezoelectric patches surface chamfering is avoided electrode and thermal deformation tube short circuit.Between the periphery of thermal deformation pipe and piezoelectric patches, do not stay the gap, and adiabatic membrane is set, make it to closely cooperate, make full use of the radial expansion of thermal deformation pipe, improved thermoelectrical efficiency.In the piezoelectric patches periphery piezoelectric patches is formed tension force during the thermal deformation tube swelling, when the thermal deformation pipe shrinks piezoelectric patches is formed pressure.The thermal deformation pipe axially and radially all piezoelectric is applied precompression.

Claims

1, a kind of thermoelectric element is characterized in that:

Comprise thermal deformation pipe and plurality of piezoelectric materials, volume increased when the thermal deformation pipe was heated, and volume reduces during cooling;

Described piezoelectric successively is stacked in the thermal deformation pipe.

2, according to claim 1 described element, it is characterized in that:

The two ends use side cap seal of thermal deformation pipe is stifled.

3, according to claim 1 or 2 described elements, it is characterized in that:

Between the periphery of described thermal deformation pipe and piezoelectric, heat insulation layer is set.

4, according to claim 2 described elements, it is characterized in that:

The polarised direction of adjacent piezoelectric is opposite.

5, according to claim 1,2 or 4 described elements, it is characterized in that:

The periphery of described piezoelectric and thermal deformation inside pipe wall are close fit.

6, according to claim 3 described elements, it is characterized in that:

The periphery of described piezoelectric and thermal deformation inside pipe wall are the interlayer close fit.