CN1560534A - Method for arranging glass bar width of parabolic refraction solar light collector - Google Patents

Abstract

The invention is a distribution method for glass stripes of a parabolic cylinder solar condenser, in condition that the photic surface is plane, part of the reflection ray is out of the photic surface along with the increase of angle alpha between the parabolic cylinder surface and the horizon plane, thus the light gathering efficiency is decreased. The invention determines the width of the glass stripes of the parabolic cylinder solar condenser through creating a mathematic model Wi=(1-4i2a2L2)L, guarantees all the light are in the photic surface, increasing the efficiency of the solar condenser.

Description

The seriation method of parabolic pole break face shape solar concentrator width of glass twigs

Technical field

The present invention relates to a kind of parabolic pole break face shape solar concentrator, the wide seriation method of particularly a kind of parabolic pole break face shape solar concentrator glass bar.

Background technology

Development and use solar energy is the effective means that solves human energy crisis, and present various countries have all dropped into great amount of manpower and material resources and carried out going deep into extensive studies to this.And the solar concentrator that development has practical value is realized the low-cost solar energy density that improves, then be promote one of main path that solar energy is extensively used (Liu Yuhang. photovoltaic concentration technology new development [J]. solar energy, 1999, (4): 5-8.).Solar energy through can be widely used in behind the optically focused light-heat utilization (generating, refrigeration), light-many fields such as Fu generating (Yang Zhiyong. solar energy optical-thermal coupling approach pre-test [M] .21 century solar energy new technology under the optically focused condition, 2003:490-492; Ben Son B.Acrylic solar energy reflecting film 3Mbrand ECP-224[M] .propr solar Energy ASES, 1993.).Present parabolic curved surface of column shape solar concentrator, common parabolic curved surface of column silvered glass by the slushing is fixed on the support and constitutes, this concentrator can not be widely used in practice, mainly have following defective: flat glass hot bending in particular manufacturing craft becomes the required professional Processes and apparatus in silver-plated again reflecting layer behind the parabolic cylinder, causes its processing cost to increase considerably; Owing to be operated in the abominable large natural environment, be coated with protective paint behind the copper facing protective layer again or its silvered face such as further protected at measure although adopt with plastics, its argentum reflecting layer still can come off in one, two year and lose use value.Be in the utility model patent 02224631.2 in the groove of parabolic curved surface of column shape framework

Be connected with the silver-plated double glazing bar in a plurality of planes successively side by side, folding face shape parabolic cylinder solar concentrator (Ning Duo etc. the design [J] of domestic solar concentrator automatic tracking system. Xibei College of Light Industry's journal, 2002,20 (2): 59-62.), inhomogeneous from theory and practice in conjunction with efficiently solve the optically focused that reflection-type parabolic cylinder concentrator commonly used in use exists always, Machining of Curved Surface expense height, short three problems of life-span, reached the purpose that improves solar energy density, but when finding in practice that this product is cylinder for sensitive surface (as solar water heating pipe), effect is optimal; And be the situation (as solar photovoltaic cell panel) on plane for sensitive surface, partial reflection light is positioned at beyond the sensitive surface, thereby cause the decline of light gathering efficiency, with photovoltaic battery panel as sensitive surface, make its plane into the folding face and also can address this problem, but bring very big difficulty can for the sealing technology of photovoltaic battery panel.

Summary of the invention

The object of the present invention is to provide a kind of light that can guarantee that concentrator reflects all to be in the light plane, thereby improve the wide seriation method of parabolic pole break face shape solar concentrator glass bar of the efficient of solar concentrator.

For achieving the above object, the seriation method that the present invention adopts is: at first make the parabolic curved surface of column shape framework 1 that is made of two parabolic shape channel-section steels, be connected with the silver-plated double glazing bar 2 in several planes in the groove of parabolic curved surface of column shape framework 1 successively side by side, it is characterized in that: the width W of glass bar 2 is by W _i=(1-4i ²a ²L ²) L determines, i=1 wherein, 2,3 ... n-1, α is α for parabolic angle with horizontal plane, L is the light plane width.

The width that will constitute the glass bar of folding face shape parabolic post solar concentrator owing to the present invention narrows down along with the increase of the angle α of parabolic and horizontal plane, can guarantee that then the light that concentrator reflects all is in the light plane, thereby reach optimum efficiency, improve the efficient of solar concentrator.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the A-A cutaway view of Fig. 1;

Fig. 3 is the B-B cutaway view of Fig. 1;

Fig. 4 is the parabolical light path schematic diagram of broken line shape of the present invention;

Fig. 5 is the light path schematic diagram that the present invention rolls over face shape parabolic sensitive surface;

Fig. 6 is the angular relationship between incident ray of the present invention, reflection ray and reflecting surface.

The specific embodiment

Referring to Fig. 1,2,3, the present invention includes the parabolic curved surface of column shape framework 1 that constitutes by two parabolic shape channel-section steels, in the groove of parabolic curved surface of column shape framework 1, be connected with the silver-plated double glazing bar 2 in several planes successively side by side, referring to Fig. 4, by geological theorems as can be known, the width L in optically focused zone and line segment P ₁C equal in length (the parallel segment system between parallel lines equates).As shown in Figure 5, because of the double-deck silver-plated reflective parabolic post solar concentrator of folding face shape for a reality, in order to obtain big as far as possible sectional area, a value is generally all very little, then Δ P ₁P ₂C is obtuse triangle (wherein, ∠ P ₁P ₂C＞pi/2).So with any one width of glass twigs P ₁P ₂Δ P for the limit ₁P ₂Among the C, ∠ P ₁P ₂C 〉=∠ P ₂CP ₁So width of glass twigs W (is line segment P ₁P ₂Length) smaller or equal to line segment P ₁The length of C.If all width of glass twigs all are W=L, then when α=0, ∠ P ₁P ₂C=∠ P ₂CP ₁=0, and the W=L establishment (is line segment P ₁P ₂With line segment P ₁C overlaps); But along with the increase of parabola with the angle α of horizontal plane, width is that the glass bar of W (is line segment P ₁P ₂) distributed areas of institute's reflection ray must exceed beyond the sensitive area QM.If guarantee whenever reflection ray must be distributed in the sensitive area QM, then must suitably reduce the width of glass bar.

Referring to Fig. 6, α=β=γ now establishes P ₁P ₂Width of glass twigs is W, and the light plane width is L, and the number of glass bar is n, then P ₁C=QM=L, and at Δ P ₁CP ₂In, P ₁C=L=P ₁B+BC=Wcos α+Wsin α * tan2 α is so have

$W=\frac{L}{\sin \mathrm{\α}\tan 2\mathrm{\α}+\cos \mathrm{\α}}=\frac{L}{\frac{\tan \mathrm{\α}}{\sqrt{1+{\tan }^2\mathrm{\α}}}\frac{2\tan \mathrm{\α}}{(1-{\tan }^2\mathrm{\α})}+\frac{1}{\sqrt{1+{\tan }^2\mathrm{\α}}}}$

$=\frac{L}{\frac{1+{\tan }^2\mathrm{\α}}{\sqrt{1+{\tan }^2\mathrm{\α}}(1-{\tan }^2\mathrm{\α})}}=\frac{1-{\tan }^2\mathrm{\α}}{\sqrt{1+{\tan }^2\mathrm{\α}}}\×L$

So, all have to each glass bar

$W_i=\frac{1-{\tan }^2{a}_i}{\sqrt{1+{\tan }^2{\mathrm{\α}}_i}}\×L----(i=\mathrm{1,2,3}\mathrm{\Λn}-1)----\left(1\right)$

In conjunction with Fig. 4, Fig. 5, the linear equation of any one section broken line (representing a glass bar) is again:

Yp ₁p ₂＝a(x ₁+x ₂)x-ax ₁x ₂????????????????????????????(2)

Wherein, a is parabolic equation y=ax ²In constant coefficient, x ₁x ₂Be p ₁p ₂Projected length,

When i=1, $x_1=\frac{L}{2}$

$x_2=\frac{L}{2}+W_1\cos {\mathrm{\α}}_1=\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{\sqrt{1+{\tan }^2{\mathrm{\α}}_1}}\×L\×\frac{1}{\sqrt{1+{\tan }^2{\mathrm{\α}}_1}}=\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L$

$\tan {\mathrm{\α}}_1=a(x_1+x_2)=a(\frac{L}{2}+\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L)=\mathrm{aL}(1+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1})=\frac{2\mathrm{aL}}{1+{\tan }^2{\mathrm{\α}}_1}$

Equally, when i=2:

$x_2=\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L$

$x_3=x_2+W_2\cos {\mathrm{\α}}_2=\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L+\frac{1-{\tan }^2{\mathrm{\α}}_2}{1+{\tan }^2{\mathrm{\α}}_2}\×L$

$\mathrm{tg}{\mathrm{\α}}_2=a(x_2+x_3)=a(\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L+\frac{L}{2}+\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}\×L+\frac{1-{\tan }^2{\mathrm{\α}}_2}{1+{\tan }^2{\mathrm{\α}}_2}\×L)$

$=2\mathrm{aL}(\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}+\frac{1}{1+{\tan }^2{\mathrm{\α}}_2})$

Can get equally:

$\tan {\mathrm{\α}}_3=a(x_3+x_4)=a(\frac{L}{2}\×2\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}L+2\frac{1-{\tan }^2{\mathrm{\α}}_2}{1+{\tan }^2{\mathrm{\α}}_2}L+\frac{1-{\tan }^2{\mathrm{\α}}_3}{1+{\tan }^2{\mathrm{\α}}_3}L)$

$=2\mathrm{aL}(\frac{1-{\tan }^2{\mathrm{\α}}_1}{1+{\tan }^2{\mathrm{\α}}_1}+\frac{1-{\tan }^2{\mathrm{\α}}_2}{1+{\tan }^2{\mathrm{\α}}_2}+\frac{1}{1+{\tan }^2{\mathrm{\α}}_3})$

Continue successively,

$\tan {\mathrm{\α}}_i=2\mathrm{aL}(\underset{k}{\overset{i-1}{\mathrm{\Σ}}}\frac{1-{\tan }^2{\mathrm{\α}}_i}{1+{\tan }^2{\mathrm{\α}}_k}+\frac{1}{1+{\tan }^2{\mathrm{\α}}_i})----\left(3\right)$

For the double-deck silver-plated reflective parabolic post solar concentrator of folding face shape of a reality, in order to obtain big as far as possible sectional area, a value is generally all very little, in our sample, gets a=0.0002, and sectional area is 1200 * 2200mm ², promptly the parabola section equation of concentrator is: y=0.0002x ²

According to (1) formula and (3) formula, can obtain:

tanα ₁≈2aL?????????????W ₁＝(1-4a ²L ²)L

tanα ₂≈4aL?????????????W ₂＝(1-16a ²L ²)L

tanα ₃≈6aL?????????????W ₃＝(1-36a ²L ²)L

……

∴tanα _i≈2iaL???????????????????????????????????????(4)

Be that to accumulate in width be W to reflected sunlight _iThe width of glass bar in optically focused zone

W _i＝(1-4i ²a ²L ²)L?????????????????????????????????????(5)

The formula of being derived above utilizing (5) can calculate at an easy rate and can guarantee that it is W that reflected sunlight is accumulated in width _iThe width of glass bar in optically focused zone.Width as the glass bar of the 10th position is:

W ₁₀＝(1-4×10 ²×10 ^-4×2×2 ²×10 ^2×2)L＝(1-0.16)L＝0.84L

According to the method, the double-deck silver-plated reflective parabolic post solar concentrator of folding face shape for the width L=100mm of sensitive surface, then the developed width of each glass bar is as shown in table 1: wherein the position of glass bar in parabola used i=0,1,2,3 respectively ... 10 or the like represent the therefrom order on mind-set both sides, W _iExpression is placed on the width of the glass bar of diverse location.

The glass bar of table 1 diverse location and the table of comparisons of its width

??i	??0	??1	??2	??3	??4	??5	??6	??7	??8	??9	??10
												??W i	?100	??99.84	??99.36	??98.56	??97.44	??96.00	??94.24	??92.16	??89.76	??87.04	??84.00

For suitability for industrialized production and installation, this method is simple: earlier silver-plated double-deck reflecting glass is cut into successively in bulk the glass bar of all size width respectively, and compiles successively and go up number, as 0 ^#, 1 ^#, 2 ^#, etc., be identified in glass back, be bumped into successively in order when mounted that (and noting the both sides symmetry) gets final product in the parabolic post groove.But for a 1.2*2.4M ²The double-deck silver-plated reflective parabolic post solar concentrator of folding face shape, with respect to wide glass bar structure, its light gathering efficiency can improve 8%.

Claims (1)

1, a kind of seriation method of parabolic pole break face shape solar concentrator width of glass twigs, at first make the parabolic curved surface of column shape framework [1] that constitutes by two parabolic shape channel-section steels, be connected with the silver-plated double glazing bar [2] in several planes in the groove of parabolic curved surface of column shape framework [1] successively side by side, it is characterized in that: the width W of glass bar [2] is by W _i=(1-4i ²a ²L ²) L determines, i=1 wherein, 2,3 ... n-1, α is α for parabolic angle with horizontal plane, L is the light plane width.

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