CN101592403A

CN101592403A - Large-scale, efficient, relatively low cost groove type solar boiler system

Info

Publication number: CN101592403A
Application number: CNA2009101453756A
Authority: CN
Inventors: 冯益安
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-05-18
Filing date: 2009-05-18
Publication date: 2009-12-02

Abstract

Large-scale, efficient, relatively low cost groove type solar boiler system belongs to integrated application fields such as optics, calorifics, thermal conduction study, materialogy, mechanical kinetics, astronomy.At present groove type solar boiler (heat collector) is comparatively economic model of solar energy heat utilization field, but the thermal efficiency low (having only 20%-40%), cost are higher relatively, mechanical support control assembly complex structure, the low defectives such as (generally having only 30-80) of optically focused multiplying power.And the present invention utilizes large-scale open slot to improve optically focused multiplying power and efficient; Utilize the accommodation windbreak, land the enhancings " wind loading rating " that reduce cost such as a rotation, circular arc and differential parabolic minute surface, focal axis rotation; Utilize the compound groove technology of " skewed slot " " positive groove " gradient to improve optically focused multiplying power and efficient; Utilize the parabola support to combine and reduce machining and assembling difficulty with the split minute surface; Utilize the metallic cavity formula absorb to increase absorptivity and reduce cost.Its integrated heat efficiency can reach more than 50%, and cost is reduced to below 1000 yuan/square metre, can be widely used in solar energy steam boiler and large-sized solar slot type power station.

Description

Large-scale, efficient, relatively low cost groove type solar boiler system

Technical field:

Optics, calorifics, thermal conduction study, materialogy, mechanical kinetics, astronomy, mathematics

Background technology:

The development of world wide internal groove heat collection technology at present is mainly used in groove type solar thermal-arrest and groove type solar generating.Though other solar energy heating mode costs are lower relatively, cost is still at 2000-5000 yuan/every square.The optically focused multiplying power is generally at 30-80, and the thermal transition efficient of solar energy is at 20-40%.

Summary of the invention:

By the improvement to each key link of slot type collecting system, positive groove skewed slot gradient is compound, the parabolic linear structure of framework combines with the split minute surface, vacuum tube absorbs reform such as the current techique that changes the cavity absorption into such as changing into by increase opening surface, raising optically focused ratio, the positive groove of the single formula of minute surface.Add the supporting construction technology of " landing " and reduce that whole groove rotates cost, accommodation windbreak technology reduces large-scale paraboloidal mechanical load.And slot type parabolic minute surface become circular arc and differential parabolic minute surface compound in the tracking of slot type one dimension change the tracking of single focal axis into.Make the solar groove type cost reduce to 1000 yuans/below every square or " lower ", the optically focused multiplying power rises to 150-2000, the solar heat conversion ratio rises to more than 50% or " higher ", and making solar energy replace traditional energy as " new forms of energy " large-area applications becomes possibility.

Description of drawings:

Fig. 1 is 8 meters of opening diameters, and 2 meters of focal lengths (2000mm), parabolic equation are that the parabola of x square=8000y dwindles figure.

Fig. 2 is the large-scale groove schematic appearance that parabola shown in Figure 1 is formed, and mainly shows its frame structure.

Fig. 3 is that the axle rotation system of large-scale groove shows.Wherein 1 is block mirror surface, and 2 is the central shaft bracing frame, and 3 for the cavity absorption piece is " focal line ", and 4 is the supporting mechanism of absorption piece.

Fig. 4 is " skewed slot " schematic diagram, when thing is placed then parabola westwards tilt, be placed on the east of positive groove.

Fig. 5 is " positive groove " schematic diagram, and parabola is perpendicular to horizontal plane, just, skewed slot gradient compound tense is placed on the middle part.

Fig. 6 is " skewed slot " schematic diagram, when thing is placed then parabola tilt eastwards, be placed on western part of positive groove.

Fig. 7 is simple and easy cavity absorption piece cross-sectional view, and wherein 1 is the infrared reflection face, and 2 is vacuum layer or the heat-insulation layer be made up of other materials, and 3 is water and wet goods working medium, and 4 is zigzag light absorption face, can plate selective coating.

Fig. 8 is a modified, and its " cavity " characteristics are more outstanding, and wherein 1 is the infrared reflection face, and 2 is vacuum layer or the heat-insulation layer be made up of other materials, and 3 is water and wet goods working medium, and 4 is zigzag light absorption face, can plate selective coating.

Fig. 9 is a glass printing opacity vacuum type " cavity ".Wherein 1 is the infrared reflection face, and 2 is vacuum layer or the heat-insulation layer be made up of other materials, and 3 is water and wet goods working medium, and 4 is zigzag light absorption face, can plate selective coating.5 is vacuum layer, and 6 is the high temperature resistant far-infrared reflection glass of high printing opacity.

Figure 10 is the reprint of Fig. 9 structure, external form is the same, but water and wet goods working medium have been placed on absorbed layer bottom, glassy layer top, be specially: 1 and 7 are the infrared reflection face, 2 and 5 is vacuum layer or the heat-insulation layer be made up of other materials, 3 is water and wet goods working medium, and 4 is zigzag light absorption face, can plate selective coating.6 is the high temperature resistant far-infrared reflection glass of high printing opacity.

Figure 11 is the light absorption face after improving.

Figure 12 is the cross section of circular arc and the compound groove of parabolic minute surface.Wherein 1 is the direct sunlight line, and 2 is the circular arc center of circle and each differential parabolic focus, and 3 is differential parabolic minute surface, and 4 is arc surface.S0, S1, S2, S3, S4, S5, S6, S7, S8 are differential parabola schematic diagram.

Figure 13 lands the technology schematic diagram for accommodation windbreak technology and turning cylinder.1 is turning cylinder, and 2 is the holddown groove of turning cylinder, and 3 is supporting bracket, and 4 is synchronous a thousand pieces of gold top, and 5 are the supporting construction schematic diagram of accommodation windbreak, and 6 are the arc wind board of accommodation windbreak, and 7 is the grooved parabola, and 8 is the direct sunlight line.

Concrete Implementation Modes:

The present inefficient reason of groove type paraboloid concentration applications: the low low temperature class that is similar to of optically focused multiplying power is used, in cryogenic applications, require light absorption part low such as the efficiency of light absorption high IR line tranmitting frequency of vacuum tube, but do not accomplish in the printing opacity technology of glass actually visible light and near infrared high absorption are reached far reflection, so the glass that a large amount of heats sees through vacuum tube with the form of far infrared radiation is dispersed into beyond the heat collector, " heat is imitated " of causing vacuum tube to absorb is low.

For the problem of present existence, can go to solve by another kind of approach, when optically focused multiplying power height to 200 was above, the thermal efficiency was usually above 50% such as solar cooker and tower generating.Promptly go to solve the problem of slot type " efficient " and cost by large-scale groove, high concentration ratio.

The solar cooker optically focused multiplying power of point focusing formula is between 200-2000, and as heat absorption body efficient Gao Shikeda 70%, when the optically focused multiplying power was above above 2000, although " water " is arranged as the cooling material, metal still melted, the kettle bottom hole with common aluminum kettle teapot.The optically focused multiplying power of tower generating surpasses 200, and hot effect can reach 58%, and reason is " optically focused ratio " height.Reason is such, and also in release heat, the heat that heat collection body is assembled in the unit interval was far longer than liberated heat when object absorbed heat, and hot effect will improve, and high concentration ratio just in time has this effect.But the slot type collecting system is because of its design feature, and generally between 30-80, it is difficult really that the slot light collection multiplying power is brought up to more than 200 for the optically focused multiplying power.Large-scale groove type paraboloid system is also because of complex structure and consider that problem such as wind lotus also can increase cost.Consider above factor, can solve with the following methods:

1, big opening parabolic troughs, high optically focused multiplying power.Channel opening is generally greater than 3 meters, and according to the focal line width of design, the optically focused multiplying power is higher than 200, and design channel opening width 5 meters, 6 meters, 7 meters, 8 meters, 10 meters even 30 meters (compound in conjunction with following positive skewed slot gradient) can be considered." large-scale groove " opening is defined in more than 3 meters, and the optically focused multiplying power is more than 150.Under corresponding optically focused multiplying power, different regions illuminance difference, strictness notion accurately should be " energy-flux density ", i.e. the size of the unit are received radiation power of absorber." large-scale groove " notion is relative, and the notion of large-scale groove necessarily requires the unit are distribution power to reach 10-100w/cm ², best optically focused is than about 1000, aluminum receiver best power distribution 60w/cm ²About.And groove type solar power distribution density has only 2-5w/cm by the analysis of 30-80 optically focused multiplying power in general area at present ²..

2, rotate cost and wind lotus.The low distinguishing feature that has high concentration ratio again and reduce unit sunlight area cost of minute surface cost, but along with the increase of grooved area, its weight also can increase, and rotates cost and wind lotus factor and becomes complicated.How to address this problem? following several mode can be arranged: one, accommodation windbreak technology is separated windbreak and slot type structure, and groove type paraboloid is " gently " matter structure, and according to the different wind directions of different regions different time seasonal windbreak is set.Such as windbreak can being reinforced on north in the winter time, and can reduce the windbreak height summer in order to avoid stop sunray and reserve more spaces.When the design grooved is parabolic, the wind lotus can be considered within the windbreak technology like this.The windbreak technology can be changed from passive to active simultaneously, can become active Wind Power Utilization technology, does not state here.Two, support turning cylinder and " land " technology.Groove type paraboloid has a turning cylinder, and on supporting bracket, the paraboloidal part or all of center of gravity of grooved is gathered in turning cylinder usually, and cost is higher like this.Show that as Figure 13 the parabolic center of gravity of grooved mainly is gathered in lands on the turning cylinder, and turning cylinder rotates in deep-slotted chip breaker and belongs to " the petty wiping of rolling ", owing to turning cylinder in deep-slotted chip breaker in case spline moving axis " dislocation ".Figure 13 shaft is thicker, can be hollow, and that in fact can do is less, and must make stent support that big of center of gravity is assembled in turning cylinder simultaneously.This sample prescription makes the power of synchronous jack less.Three, the focal axis rotating technique.Focal axis (being the absorption piece at focal line position, to call focal axis in the following text) is rotated.As Fig. 1, Fig. 2, shown in Figure 3, for the parabolic troughs of aperture area less than 3 meters, even its optically focused focal line width is accomplished 2cm, its optically focused multiplying power also can be less than 150, and optically focused " focal line " width of the groove of generally making with low-cost plated film and reflective membrane is 5-12cm, if the parabolic troughs opening is done greatly, can reduce mechanical strength again and solve wind loading rating, imitate very beneficial to saving the slot type cost and improving heat.Focal line became " loosing " shape when but common groove type paraboloid changed at light, and it is big more that light departs from the center, and " focal line " more becomes one bigger " focal plane ", and after all, regular parabolic can not focus on when the sunlight angle changes at all.Address this problem, can take the parabolic composite algorithm of arc surface and differential.As Figure 12, promptly do a cylindrical surface, fixing many " miniature " parabola of in the inside, " miniature " is relative, sets according to the requirement of " focal line " width in the reality.And each piece parabola all is the different parabola of focal length, because position difference in circular arc, it all is positioned at the center of circle of circular arc with respect to (as Figure 12) its focus when the sunshine vertical incidence of the position in the circular arc.Parabola is not a circular arc, but during its differential near circular arc.Parabola presses close on every side circular arc.This mode is made comparatively trouble, and error is arranged.But can make the minute surface relative fixed, also can seasonal adjustment, focal axis only needs rectilinear motion just can be similar in other words conj.or perhaps " bluring " to focus on every day.

3, positive groove skewed slot gradient is compound.The plane parabola of determining with X-axis and Y-axis (equation x^2=2PY or X square=4fy) along the translation of Z axle, the parabolic troughs that obtains is " just groove ", just " groove " seen in our present production practices decades.(equation x^2=2PY or the X square=plane 4fy) determined with X-axis and Y-axis " groove " that (plane included angle greater than 0 ° less than 45 °) obtain along the translation of Z axle that tilt at a certain angle is tipper, abbreviation " skewed slot " to the plane parabola of determining with X-axis and Y-axis.Tipper is from seeing not " inclination " in appearance, and the mode difference when just processing minute surface is compared with positive groove, and the angle change has taken place in the section of the every bit on the slot type mirror surface of sustained height position.

The groove that " skewed slot " placed for the groove and the north and south of thing placement is all very useful.Because on the groove relatively the angle of inclination in the section of the every bit of " positive groove " same position change, cause thing (or north and south) position of focal line to change and produce height change.Need redefine parabolic equation with " positive groove " compound tense.If two flat inclinations=α, then parabolic equation is: X square=4fy/cos α, wherein f is the focal length (being the distance of parabola initial point to focus) of positive groove.Under same light irradiation, the focal line of " skewed slot " can overlap wholly or in part with the focal line of " positive groove ", and concrete condition needs specifically to calculate according to designing requirement.

The groove that " positive groove skewed slot gradient compound " just is meant the inclination different angles is arranged in order and is arranged in positive groove according to the size at certain angle of inclination.Purpose is to allow the focal line of different grooves condense together, and improves the optically focused multiplying power.Simultaneously because thing is placed or place in north and south " positive groove " at sunshine thing, north and south, almost always have focal line sunlight to tilt groove during three dimensional change up and down, cause energy waste and cause potential safety hazard, and the compound groove of gradient can be stopped this defective.

Fig. 4, Fig. 5, Fig. 6 are the schematic diagrames of tipper.Wherein Fig. 4 is placed in the arrangement of the groove that thing is placed in the east, and the parabola of groove can be understood as parabola and westwards tilts along the vertical line direction of horizontal plane.Fig. 5 is positive groove.Fig. 6 is placed on the west, and the parabola of groove can be understood as parabola and tilts eastwards along the vertical line direction of horizontal plane.This figure is a schematic diagram, can carry out " gradient is compound " by multiple tipper in the production.

4, parabolic framework linear structure combines with the split minute surface.Large-scale paraboloidal processing is compared with little minute surface groove to occupy with installation many differences, needs structure and measure-alike parabola support and parabolic minute surface to combine.Parabolic troughs such as 8 meters of openings, because can left-right symmetry, so as long as processing half lines wherein are as the parabola supporting bracket, left-right symmetry also is arranged in order, form the framework network structure, as Fig. 2 and Fig. 3. parabolic mounting system can independently exist, and the mechanical strength wind force proofing design is all considered wherein.The split minute surface can design width 0.5-2 rice length 1-3 rice split minute surface, is promptly adding man-hour the minute surface segmental machining, is convenient to processing, transportation, assembling and maintenance.This mode becomes loaded down with trivial details and breaks the whole up into parts into simple, can reduce cost.

5, cavity absorbs.At present people generally take vacuum type plated film steel pipe and straight-through type vacuum pipe as light absorption part, because thermal-arrest needs long period and energy-flux density less, take this " tubulose " absorption pattern that positive effect is arranged in the cryogenic applications field.But as high temperature field in light collecting, consider " cost " and " efficient " factor, can use the cavity absorption pattern.The characteristics that cavity absorbs require absorbing surface and peripheral insulation construction separately shown in Fig. 7,8,9,10,11, reduce area of dissipation; Require absorbing surface " deceive " and as the shape of similar " hole " type.Light enters in " cavity " absorbing surface just as " black hole " and seldom is reflected, at " cavity " even in have reflection ray also to be absorbed repeatedly by other " black matrixes " in " cavity ".Infra-red radiation is also repeated to absorb by " black matrix " in the cavity, reaches the minimum loss of heat like this.

Below in conjunction with accompanying drawing " cavity " absorption piece is described further:

Fig. 7 is simple and easy cavity absorption piece cross-sectional view, and wherein 1 is the infrared reflection face, and working medium is returned in the assurance heat radiation substantially, reduces heat loss.2 is vacuum layer or the heat-insulation layer be made up of other materials, isolated or alleviate the heat conduction.3 is water and wet goods working medium, and the heat of absorption is poly-in this lamination, arrives to a certain degree to break through the pressure valve outflow.4 is zigzag light absorption face, and zigzag is for increasing its absorption area, and prevents from not absorb light (being reflection ray) and appear easily and cause energy loss.Black matrix can plate selective coating increases absorption.

Fig. 8 is a modified, and its " cavity " characteristics are more outstanding, and its light is more difficult to appear.

Fig. 9 is a glass printing opacity vacuum type " cavity ".Promptly to absorb in order better promoting, to reduce the loss, increased following transparent glass and vacuum layer, transparent glass requires to have high temperature resistant function, visible light and near infrared height and sees through function and far reflection function.But adding the corresponding raising of cost in man-hour like this, install and life of product etc. influenced by it all, considers alternative application or need not from " cost performance ".

Figure 10 is the reprint of Fig. 9 structure, and external form is the same, but water and wet goods working medium have been placed on absorbed layer bottom, glassy layer top, so more helps light and absorbs, and imitates and do not consider can an examination under the situation of " cost " in the heat that covets.Be specially: 1 and 7 for the infrared reflection face, and 2 and 5 is vacuum layer or the heat-insulation layer be made up of other materials, and 3 is water and wet goods working medium, and 4 is zigzag light absorption face, can plate selective coating.6 is the high temperature resistant and far-infrared reflection glass of high printing opacity.

Figure 11 is the light absorption face cross-sectional view after improving.Be convenient to both sides light and absorb, have more using value.

The general 5-15cm of the width of light absorption face, also can be wide slightly or narrower slightly, the length of cavity absorber is because be metal parts (as aluminium) mainly, that can do is longer, the centre can add helicitic texture (similar expansion joint), but two ends additional flange dish when needing cavity length longer in the engineering, gets final product with conventional ring flange connection.

Claims

1, high-temperature boiler system in a kind of high-efficiency and low-cost groove type solar.Be characterized in the thermal efficiency greater than 50%, cost can be lower than 1000 yuan/square metre.Mainly bear by large-scale, high concentration ratio, accommodation windbreak and minute surface that the wind lotus separates, turning cylinder " lands " or circular arc and the compound focal axis of differential parabolic minute surface are rotated approach such as relative motionless, the parabolic framework of minute surface and the combination of split parabolic minute surface, positive groove skewed slot gradient are compound, cavity type light absorption and realized.

2, according to 1 characteristics of describing, its high efficiency and low cost realize by " large-scale " and " high concentration ratio " that mainly the large-scale channel opening diameter that refers generally to is at 3-30 rice, and optically focused is than between 150-2000 (common international practice slot light collection ratio has only 30-80).Unit are distribution power 10-100w/cm when receiver is used the metallic aluminium goods ², best optically focused is than about 1000, receiver best power distribution 60w/cm ²About.Can carry out corresponding calculating with copper and gold, silver, diamond etc. according to the coefficient of conductivity and fusing point during as heat transfer medium.

3, according to 1 characteristics of describing, large-scale groove rotates, wind lotus factor complexity, uses accommodation windbreak technology instead, and windbreak wind lotus separates with parabolic minute surface wind lotus, and promptly accommodation windbreak technology is one of high-temperature boiler systems technology in this groove type solar.

4, according to 1 characteristics of describing, the turning cylinder technology of " landing " is of value to and alleviates rotating load, is one of key technology.

5, according to 1 characteristics of describing, except minute surface rotates, also have a kind of mode to be exactly: circular arc is relative motionless with the compound focal axis rotation of differential parabolic minute surface minute surface, and this mode can allow minute surface suitably adjust by season.

6, according to 1 characteristics of describing, because of its " large-scale ", adding at it needs merogenesis burst design processing and fabricating man-hour, carry out to have the frame structure of wind loading rating, frame structure by monomer parabola support to intert or welding manner connects.The about 1-6m of each sheet daylighting area of split minute surface ², and fixedly connected with screw and nut between the support.

7, according to 1 characteristics of describing, because large-scale groove is when thing or north and south placement, when solar declination or elevation angle variation, total some light exceeds outside the notch, cause energy loss and have potential safety hazard, adopt positive groove skewed slot gradient combined type can avoid this shortcoming, and can several times of increase optically focused multiplying powers.Positive groove and skewed slot notion: the plane parabola of determining with X-axis and Y-axis (equation x^2=2PY or X square=4fy) along the translation of Z axle, the parabolic troughs that obtains is " just groove ".The curved surface " groove " that the plane parabola of determining with X-axis and Y-axis (equation x^2=2PY or the X square=plane 4fy) determined with X-axis and Y-axis tilt at a certain angle (greater than 0 ° less than 45 °) obtains along the translation of Z axle is tipper, abbreviation " skewed slot ".The curved surface groove that the parabola of differing tilt angles obtains along the translation of Z axle is arranged in order " gradient is compound " that together is called groove.

8, according to 1 characteristics of describing, the cavity absorption plant mainly prevents the infrared radiation of luminous ray reflection and high temperature absorber, be characterized in that this device not only has one " cavity ", and many wrinkle multiaspects have " black matrix " characteristic in the cavity, the more important thing is that the area insulation material greater than 1/2 surrounds in the cavity peripheral structure, be different from straight tubular plated film steel pipe or straight-through type vacuum pipe like this, purpose is to increase absorptivity and reduces heat loss, and also being not precluded within this structure below certainly increases a floor height printing opacity, high temperature resistant, far-infrared reflection glass and vacuumize.