CN103530697B - The mirror field Optimization Design of radial pattern tower type solar thermoelectricity system - Google Patents

Abstract

The invention discloses a kind of radial pattern tower type solar thermoelectricity system mirror field Optimization Design, the method is using the product of the integrated optical efficiency of Jing Chang and the land cover pattern rate of Jing Chang as optimization aim, using simplex algorithm is that optimized variable is optimized to the radial spacing coefficient of Jing Chang and circumference spread ratio, make the quantity of heliostat be arranged in certain specific in the case of, optimization aim value is maximum.The mirror field Optimization Design of the present invention solves the contradiction between heliostat quantity and mirror field integrated optical efficiency, and uses simplex algorithm to have more preferable robustness and stability.The integrated optical efficiency of the little Jing Chang of radial pattern being laid out by the mirror field Optimization Design of the present invention has all reached more than 80%, improves 10% relative to existing general Jing Chang.

Description

The mirror field Optimization Design of radial pattern tower type solar thermoelectricity system

Technical field

The present invention relates to technical field of solar, particularly relate to radial pattern tower type solar thermoelectricity system Mirror field Optimization Design.

Background technology

Tower system, also known as integrated system, mainly includes some heliostats, receives tower and being installed on and connect Receive the heat extractor on tower.The operation principle of tower type solar energy thermal power generation technology is by a number of fixed Sunlight is converged to the heat extractor of tower top and produces high temperature by solar eyepiece, reheats and flows through the medium in heat extractor Luminous energy changing into heat energy, and produces high-temperature steam, pushing turbine generates electricity, and is a kind of big face Long-pending large-scale optically focused generation mode.Every heliostat each all is equipped with follower exactly by the sun Luminous reflectance focuses on the heat extractor of a high top of tower.

In whole electricity generation system, the type of arrangement of Jing Chang and scale can directly affect the optics effect of Jing Chang Rate and generated energy, also can affect the construction cost of Jing Chang simultaneously, the most how reasonably optimizing mirror field layout It is the key of Jing Chang design, and the optical efficiency the most quickly calculating Jing Chang is the premise of design optimization. The index of Jing Chang average annual integrated optical efficiency mainly includes cosine efficiency, shadow occlusion efficiency, overflows effect Rate and atmospheric transmission efficiency.Integrated optical efficiency be cosine efficiency, shadow occlusion efficiency, overflow efficiency, The product of atmospheric transmission efficiency, it may be assumed that

η_field=η_cos×η_S&B×η_int×η_At.M

Wherein, η_fieldFor integrated optical efficiency, η_cosFor cosine efficiency, η_S&BShadow occlusion efficiency, η_int For overflowing efficiency, η_At.MFor atmospheric transmission efficiency.

When solar irradiation is mapped to heliostat surface, and heliostat surface produces certain angle, by incidence The cosine value of the angle of the normal vector of the incident vector sum heliostat of light is defined as cosine efficiency.Such as figure Shown in 1, when the light of the sun 2 is irradiated to heliostat 1 surface, and heliostat 1 surface produces certain Angle theta be the angle of normal vector of incident vector sum heliostat of incident ray, i.e. cosine angle, Wherein zero is the center on ground, the absorption tower, and-X represents that due east, Y represent due south.Cosine is imitated The calculating of rate has only to determine that the coordinate of heliostat, position of sun and heat extractor position can be asked for.

During reflexing to heat extractor from heliostat, sunlight is caused because of decay in an atmosphere Energy loss be referred to as atmospheric transmission (or atmospheric attenuation) loss, and through propagate after reflection light strong The ratio of degree and reflection light intensity just is atmospheric transmission efficiency.This efficiency is generally and the position of the sun Put, local height above sea level and atmospheric condition (such as dust, dampness, the content etc. of carbon dioxide) etc. Factor is relevant.

Cosine efficiency position relative with between heliostat with atmospheric transmission efficiency is unrelated, easily asks for；And it is cloudy Shadow blocks efficiency and spilling efficiency needs in view of between minute surface and minute surface, between minute surface and heat extractor Position and angular relationship, ask for process complex.

As in figure 2 it is shown, when incident ray is irradiated to heliostat 11, is blocked by heliostat 12, make Become shade M, produce shadow loss, by the amount of light of shade and the total light shining this heliostat Ratio of number is shade efficiency；In like manner, then cause block when reflecting light and being blocked by heliostat 3 N, produces eclipsing loss, the ratio of the amount of light being blocked and the total amount of light shining this heliostat For eclipsing loss.One heliostat may occur by shade and situation about being blocked simultaneously.

When reflection light is not shone in heat extractor owing to limiting by heat extractor size, claim these Light is the light overflowed, and the light number of spilling is spilling efficiency with the ratio of total light number.

Jing Chang is optimized to the scheme of design, have and the most traditional will accept energy and cost of investment as excellent Change target, but floor space cost, wire cost that cost of investment is included, receive tower and become Design parameter such as this grade and other correlative factors such as construction material, region location, be difficult to unified estimation.But It is that heliostat quantity exists contradictory relation with mirror field integrated optical efficiency, if land area is fixed, when fixed Solar eyepiece quantity is more, arrangement comparatively dense when, more shadow occlusion loss can be produced, mirror field is whole The integrated optical efficiency of body can decrease；And when heliostat negligible amounts, arrange sparse when, The integrated optical efficiency of Jing Chang can increase relatively.

Radial pattern mirror field energy effectively reduces the eclipsing loss between before and after's heliostat, and most of Jing Chang design Layout uses radial pattern.In radial pattern mirror field, heliostat circularizes from the center of circle (receiving tower position) To external radiation radially arrangement, by distance definition is this ring the half of the heliostat on each ring to reception tower Footpath.Radial spacing and circumference spacing are the important parameters of radial pattern Jing Chang, according to the footpath of ring each in mirror field To spacing and circumference spacing, it becomes possible to obtain the arrangement position of each heliostat in mirror field.

Radial spacing refers to the difference of the radius of adjacent ring, in radial pattern mirror field, and the radius root of a rear ring Determine according to the radius of previous ring, meet below equation:

R_m+1=R_m+ΔR_min+R_coef(ΔR_max-ΔR_min), (1)

R_m+1It is the radius of m+1 ring, R_mIt is the radius of m ring, Δ R_maxFor maximum radial spacing, ΔR_minFor smallest radial spacing, R_coefFor radial spacing coefficient.When radial spacing coefficient is 0, mirror Field m ring and radial spacing (the i.e. R of m+1 ring_m+1-R_m) minimum, when radial spacing coefficient is When 1, the radial spacing of Jing Chang is maximum.

Circumference spacing refers on same ring the difference at the circumferential angle between adjacent heliostat, meets below equation:

$A_m={\mathrm{\ΔA}}_{\min }^m+A_{\mathrm{coef}}({\mathrm{\ΔA}}_{\max }^m-{\mathrm{\ΔA}}_{\min }^m),---\left(2\right)$

It is the maximum circumference spacing of m ring,It is the minimum circumference spacing of m ring, A_coef For circumference spread ratio.When circumference spread ratio is 0, the circumferential spacing of this ring is minimum, works as circumference When spread ratio is 1, the circumferential spacing of this ring is maximum.

Therefore, radial spacing coefficient and circumference spread ratio it are determined by so that it is determined that the footpath of optimized ring To distance and circumference spacing, then determine the arrangement of each heliostat in mirror field.

Summary of the invention

The present invention is directed to above-mentioned deficiency of the prior art, it is provided that a kind of radial pattern tower type solar The mirror field Optimization Design of heat and power system.

The mirror field Optimization Design of a kind of radial pattern tower type solar thermoelectricity system, including following step Rapid:

(1) determine radial pattern Jing Chang radial spacing coefficient and circumference spread ratio be optimized variable, And determine the search bound of each optimized variable respectively；

(2) using the product of integrated optical efficiency and land cover pattern rate as optimization aim, according to Jing Chang The search bound of parameter, sun disk model and each optimized variable, uses simplex algorithm to become Amount optimizes, and obtains the optimal value of each optimized variable, and described optimal value makes optimization aim take maximum；

(3) optimal value of each optimized variable obtained according to step (2), carries out radial pattern tower too The mirror field layout of sun energy heat and power system.

The mirror field Optimization Design of the radial pattern tower type solar thermoelectricity system of the present invention is by by mirror The average annual integrated optical efficiency of field and land cover pattern rate (gross area of heliostat and the given soil of Jing Chang Area ratio) product as optimization aim, use between the simplex algorithm radial direction to radial pattern Jing Chang It is optimized away from coefficient and circumference spread ratio so that the quantity of heliostat is with to be arranged in certain specific In the case of, optimization aim value is maximum.The mirror field Optimization Design of the present invention is by the comprehensive light of Jing Chang The product of the land cover pattern rate of efficiency and Jing Chang, as optimization aim, efficiently solves heliostat quantity And the contradiction between the integrated optical efficiency of mirror field, thus carry out the optimization layout of Jing Chang.Simplex search It is the optimized algorithm being not based on gradient search, comparatively fast can converge to optimal setting and have better Efficiency and availability, and simplex algorithm be again based on sequence algorithm, have more preferable robustness and Stability.Radial spacing coefficient and circumference spread ratio can describe the arrangement of radial pattern Jing Chang accurately Situation.

The search bound of the radial spacing coefficient in described step (1) is [0,1].

The search bound of the circumferential spread ratio in described step (1) is [0,1].

Variable can be effectively reduced during optimizing by limiting the search bound of optimized variable Hunting zone, improve operation efficiency.Radial spacing coefficient and circumference spread ratio are in the range of [0,1] Value, it is ensured that radial spacing and circumference spacing get all probable values.

Sun disk model in described step (2) uses Monte Carlo to spread a method and simulates it and can flow close Degree foundation obtains.

As preferably, the sun disk model in described step (2) is non-parallel incident illumination model.

The sun is the energy source of whole heat and power system, and in accurate solar model, light is to dissipate , sun surface each point has light to penetrate to any direction, observes the picture of the sun the most on earth For circle, being referred to as sun disk (Solar Disk), this is as upper Energy distribution uneven.If it is sharp Spread a method with Monte Carlo and carry out the size of simulated solar disk energy, then the closer to the position in the center of circle, point Number is the most intensive, and corresponding energy is high, then counts the most rare near disk border, and corresponding energy is low. According to the relation of sun flux-density distribution Yu sun coning angle, in conjunction with concrete time specified place too Sun position, generates the unit vector of non-parallel incident illumination.Sunlight is non-parallel light, in prior art The solar model set up mostly is parallel input light model, and the present invention spreads a method by Monte Carlo and simulates it The model that sun disk model is non-parallel incident illumination that energy-flux density is set up, is more nearly reality too Sunlight.According to the relation of sun flux-density distribution Yu sun coning angle, in conjunction with the concrete time specifically The position of sun of point, generates the unit vector of non-parallel incident illumination, according to incident vector sum heliostat Centre coordinate can calculate heliostat center and summit along incident ray projection coordinate on the ground, And corresponding unit normal vector can be calculated according to incident light vector with the reflective vector of every heliostat.

Described step (2) use Monte Carlo Ray-tracing Method calculate the integrated optical efficiency of Jing Chang.

Monte Carlo Ray-tracing Method can effectively follow the trail of the position judging every light with every heliostat Relation, also can obtain the flux-density distribution situation on heat extractor surface simultaneously, and therefore the method can be effective Computational shadowgraph blocks efficiency and overflows efficiency.

Monte Carlo Ray-tracing Method is used to calculate the shadow occlusion efficiency of Jing Chang and overflow the master of efficiency Want thought as follows:

Spread a little: utilize Monte Carlo method random throwing in the heliostat field determining scope to spread substantial amounts of point, A light is formed by any point and incidence vector.

Shade judges the stage: be sprinkling upon four summits of ground point and heliostat along entering by random throwing Penetrate light projection coordinate on the ground and determine the phase friendship of incident ray and each heliostat successively Condition, if spot projection is not in any heliostat, then considers next point, corresponding to this point Light is invalid incident ray；Otherwise judge the heliostat that this root incident ray is finally irradiated to, and ask Take the intersection point of this root incident ray and this heliostat；

Block decision stage: first calculate this reflection light corresponding to root incident ray, it is judged that reflection light Whether line is blocked by other heliostat, if not being blocked, then asks for reflecting that light is final and heat extractor Intersection point；

Overflow decision stage: judge the intersection point of this reflection light and heat extractor whether in heat extractor, if Not then for overflowing in heat extractor.

After all light is disposed, the shadow occlusion efficiency of Jing Chang can be calculated and overflow efficiency.

As preferably, described step (2) calculates platform based on CUDA and carries out variable optimization.

CUDA calculates platform and utilizes the double-deck parallel organization of GPU to realize its high performance parallel computing, Allow multiple thread calculate simultaneously and to judge, be effectively improved arithmetic speed, for the optimization of mirror field layout Design is laid a good foundation, and realizes simple, and cost is relatively low.

The mirror field Optimization Design of the tower type solar thermoelectricity system of the present invention is by the comprehensive light of Jing Chang Learn the taking advantage of of the land cover pattern rate ratio of given land area (gross area of heliostat with) of efficiency and Jing Chang Long-pending as optimization aim so that the quantity of heliostat be arranged in certain specific in the case of, optimize mesh Mark reaches maximum, efficiently solves the contradiction between heliostat quantity and mirror field integrated optical efficiency, Thus complete the optimization design of Jing Chang.Use simplex algorithm to be optimized calculating, be effectively increased meter Calculate efficiency and availability, and simplex algorithm be algorithm based on sequence, have more preferable robustness and Stability.By the average annual integrated optical effect of the little Jing Chang that the Optimization Design optimization of the present invention obtains Rate has all reached more than 80%, with the integrated optical efficiency of general tower type solar thermoelectricity system Jing Chang (70%) compare, improve 10%.

Accompanying drawing explanation

Fig. 1 is earth coordinates schematic diagram (-X-axis sensing due east, the Y-axis water of tower type solar Jing Chang Flat due south of pointing to, Z axis sensing zenith)；

Fig. 2 is shade and blocks schematic diagram；

Fig. 3 is the stream of the mirror field Optimization Design of the radial pattern tower type solar thermoelectricity system of the present invention Cheng Tu；

Fig. 4 is unobstructed top view between the heliostat of radial pattern mirror field；

Fig. 5 is unobstructed side view between the heliostat of radial pattern mirror field；

Fig. 6 is sunlight cone angle schematic diagram；

Fig. 7 is sun disk energy-flux density schematic diagram；

Fig. 8 is non-parallel incident vector composition schematic diagram；

Fig. 9 is that heliostat twin shaft fixes schematic diagram；

Figure 10 is heliostat coordinate system schematic diagram；

Figure 11 is simplex algorithm schematic diagram；

Figure 12 is that simplex initializes sequential perturbation schematic diagram；

Figure 13 is that radial pattern Jing Chang optimizes schematic diagram.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention will be further described.

In the present embodiment, radial pattern tower type solar thermoelectricity system is positioned at the Northern Hemisphere.Jing Chang in the present embodiment Parameter is as shown in table 1: tower height 30m, and the size of heliostat is 1m × 1m, and land area is with The radius R of one distance the that is first ring heliostat being ranked between solar eyepiece distance and reception tower_0,0Stretch out R_LandGivenBanding semi-ring (R in the present embodiment_LandGiven=12m), residing latitude is north latitude 30 °.

Table 1 mirror field parameters

Mirror field parameters	Concrete value
		Receive the height Hc at tower center	30m
The size (length x width) of heliostat	1m×1m
		Land area	π/2×{(R0,0+12)2-R0,0 2}
Latitude at mirror place	North latitude 30 °

The mirror field Optimization Design of the radial pattern tower type solar thermoelectricity system of the present embodiment, such as Fig. 3 Shown in, specifically include following steps:

(1) the radial spacing coefficients R of radial pattern Jing Chang is determined_coefWith circumference spread ratio A_coefFor optimizing Variable, and determine the search bound of each optimized variable respectively；

The distance received between tower and the first ring heliostat is the first ring radius R_0,0。

First, according to receive whether have on tower dead ahead axis heliostat define Essential ring and Staggered ring:

Essential ring: receive the ring having heliostat on tower dead ahead axis；

Staggered ring: receive the ring without heliostat on tower dead ahead axis.

In the present embodiment, the first ring is Essential ring, and the radius of the first ring is generally according to receiving tower target The height of point determines, its first ring radius is equal to the height receiving place, tower center, it may be assumed that

R_0,0=H_c(3)

Wherein, H_cFor receiving the height at place, tower center.According to the first ring radius R_0,0, by with lower section Method determines radial spacing coefficient and the search bound of circumference spread ratio, and determines the half of other each rings The circumferential angle of heliostat on footpath and each ring:

The search bound of (a) radial spacing coefficient

Minimum radial distance should ensure that before and after's heliostat does not collides, as shown in Figure 4 and Figure 5, M ring and m+1 ring radius minimal difference Δ R_min(i.e. the smallest radial spacing of m+1 ring) is full Foot following expression:

ΔR_min=R_m+1,min-R_m=DM × cos30 ° × cos β_L(4)

Wherein, R_m+1,minIt is the least radius of m+1 ring, R_mIt is the radius of m ring, β_LIt is Jing Chang Relative to the angle of inclination (β in the present embodiment receiving tower_L=0).DM is not occur between heliostat The distance definition of collision is safe distance, and its expression formula is:

$\mathrm{DM}=\sqrt{{l_m}^2+{w_m}^2}+\mathrm{dS}---\left(5\right)$

Wherein, l_mIt is the length of heliostat, w_mBeing the width of heliostat, dS is safe distance coefficient, this reality Execute dS=0.1m in example.

Fig. 5 is unscreened radial spacing schematic diagram between heliostat, and heliostat A is positioned on m ring, Heliostat B is positioned on m+1 ring, and corresponding with the position of heliostat A (i.e. every ring same position), Therefore m ring and m+1 ring radius maximum difference (i.e. the maximum radial spacing of m+1 ring) are full The following relational expression of foot:

ΔR_max=R_m+1,max-R_m=DMcos β_L/ cos γ, (6)

Wherein,

ΔR_maxIt is m ring and m+1 ring radius maximum difference；

R_m+1,maxIt it is the maximum radius of m+1 ring；

γ is the intermediate variable of the appearance during calculating:

$\mathrm{\γ}=\arcsin \left(\frac{\mathrm{DM}}{2d}\right)+\arcsin \left(\frac{R_m}{d}\right)-{\mathrm{\β}}_L---\left(7\right)$

D is the heliostat A center distance to reception tower center:

$d=\sqrt{{R_m}^2+(H_c-z_m{)}^2}---\left(8\right)$

z_mVertical height for the place, center of heliostat A:

z_m=R_mtanβ_L+H_h(9)

H_hIt it is the height on heliostat centre distance ground.

Except the first ring radius, obtain according to formula (3)～(9), substitute into formula (1) and get final product root The radius of m+1 ring is obtained according to m ring radius and radial spacing coefficient.The most gradually count Calculate the radius obtaining all rings.

Smallest radial separation delta R at each ring_minWith maximum radial separation delta R_maxIn the case of Yi Ding, for making Each ring radius can get all probable values, and radial spacing coefficient should meet following condition: 0≤R_coef≤ 1, I.e. radial spacing coefficients R_coefSearch bound be [0,1].

The bound of (b) circumference spacing

Circumference spacing refers to the circumferential angular distance on same ring between adjacent heliostat, in the present embodiment, On same ring, the circumferential spacing between adjacent heliostat is identical.The minimum circumference of m ring in the present embodiment SpacingFor:

${\mathrm{\ΔA}}_{\min }^m=\arcsin (\mathrm{DM}/2/R_m)---\left(10\right)$

The maximum circumference spacing of m ring should ensure that heliostat adjacent before and after on reflection direction does not occurs Block, then the maximum circumference spacing of m ringFor:

${\mathrm{\ΔA}}_{\max }^m=\left\{\begin{array}{c}\arcsin (\mathrm{DM}/2{/R}_m)+\arcsin (\mathrm{DM}/2/R_{m+1}),m=1\\ \arcsin (\mathrm{DM}/2/R_m)+\arcsin (\mathrm{DM}/2/R_{m-1}),m=\mathrm{2,3,4},......\end{array}---\left(11\right)\right.$

Formula (10) and formula (11) are substituted in formula (2), i.e. can get the circumference of m ring Angle.

Minimum circumference spacing at each ringWith maximum circumference spacingIn the case of Yi Ding, for making All phase angles of each ring can get all probable values, and circumference spread ratio should meet following condition: 0≤A_coef≤ 1, i.e. circumference spread ratio A_coefSearch bound be [0,1].

(2) using the product of integrated optical efficiency and land cover pattern rate as optimization aim, according to sun circle The search bound of dish model, mirror field parameters and each optimized variable, uses simplex algorithm to carry out variable Optimizing, when optimization aim takes maximum, the value of optimized variable is as the optimal value of each optimized variable；

(S1) Jing Chang is generated

The sequential perturbation method of initialization according to simplex algorithm, initializes each optimized variable, And according to the initial value of each optimized variable and mirror field parameters (land area size and the rule of heliostat Lattice) determine the quantity of the heliostat of optimized ring, thus calculate each heliostat of this ring further Centre coordinate and the coordinate of heat extractor, generate Jing Chang.

The present embodiment, centered by the ground at heat extractor place, is westwards X-axis positive direction from this point, to Due south is Y-axis positive direction, and Z axis points to zenith and sets up right hand rectangular coordinate system as shown in Figure 1.

The distance between first row heliostat and heat extractor according to Jing Chang, radial spacing coefficients R_coefAnd week To spread ratio A_coef, i.e. radial spacing between adjacent ring and the circumferential spacing of every ring, so that it may according to Given land area and heliostat size determine the number of rings of heliostat and every ring heliostat in mirror field Quantity, the meter of quantity I MAX of total number of rings JMAX of heliostat and every ring heliostat in radial pattern mirror field Calculation formula is as follows:

The optimization of radial pattern Jing Chang is that a ring connects a ring design, according to formula (2)～(4) and formula (5)～(9) calculate respectively Jing Chang radial spacing and circumference spacing, the radius of a rear ring with circumference Calculating of angle needs previous ring radius and the data at circumference angle, and therefore the optimization of the second ring is built upon the On the basis of one ring, optimizing of the 3rd ring is set up on the basis of the one the second rings, by that analogy. Then total number of rings JMAX of heliostat need to meet condition:

R_JMAX≤(R_0,0+R_LandGiven) (12)

R_JMAXIt it is the radius of JMAX ring.

Heliostat quantity on each ring is calculated, by the following method as a example by m ring:

First to π/A_mCarry out Modulo-two operation, then judge whether operation result is zero and according to m The type of ring determines heliostat quantity I MAX of m ring_m:

If m ring is Essential ring:

If operation result is zero, then: IMAX_m=floor (π/A_m)-1,

Otherwise, IMAX_m=floor (π/A_m)；

If m ring is Staggering ring:

If result is zero, then, IMAX_m=floor (π/A_m),

Otherwise, IMAX_m=floor (π/A_m)-1,

Floor represents and rounds downwards.

Radial pattern Jing Chang is symmetrical about Y-axis, and in symmetry, optional half is studied, in this enforcement With the heliostat of northwest corner as object of study, heliostat coordinate expressions of certain on m ring is:

$\left\{\begin{array}{c}x=R_m\sin \left({\mathrm{\ψ}}_m\right)\\ y=-R_m\cos \left({\mathrm{\ψ}}_m\right)\\ z=H_h\end{array},---\left(13\right)\right.$

ψ_mCircumferential angle for heliostat.

(S2) according to sun disk model, Monte Carlo Ray-tracing Method is used to calculate generated Jing Chang Integrated optical efficiency

Wherein, sun disk model use Monte Carlo spread a method simulate its energy-flux density set up obtain, Sun disk model for non-parallel incident illumination.

Employing equation below in the present embodiment:

$f\left(\mathrm{\α}\right)=\left\{\begin{array}{cc}{S}_0\{1-\mathrm{\λ}(\frac{\mathrm{\α}}{{\mathrm{\α}}_s}{)}^4\},& \mathrm{\α}\≤{\mathrm{\α}}_s\\ 0,& \mathrm{\α}>{\mathrm{\α}}_s\end{array}---\left(14\right)\right.$

Set up sun disk model.Wherein,

λ is constant, λ=0.5138；

S₀Same f (α) unit is the same, for W/m², its numerical value depends on the point of observation distance to the sun；

α_sIt it is sunlight cone angle₀Half, as shown in Figure 6, sunlight cone angle₀Refer to point of observation Q Tangent line P to sun disk₁Q and P₂Angle (the P of Q₁, P₂Represent point of contact respectively), α_sRepresent and see Examine the Q tangent line P to sun disk₁Q or P₂Q Yu Solar Disk central point O₁To point of observation Q Line O₁The angle of Q.Can obtain according to geometrical calculation: α_s≈(R₁/R₂)/2, wherein, too Sun radius R₁=1.39 × 10⁶Distance R of km, the sun and the earth₂=1.5 × 10⁸Km, substituting into numerical computations can : α_s≈(1.39×10⁶1.5×10⁸)/2≈4.6mrad≈0.5°；

What f (α) represented is the energy-flux density of upper any point P of sun disk (Solar Disk), and α is Line PQ and line O₁The angle of Q, when α is more than α_sTime, f (α) is equal to 0, i.e. Solar Disk Outside is black matrix.

According to formula (17), use roulette principle to randomly generate and a little carry out simulated solar energy-flux density, As it is shown in fig. 7, wherein α_sUniformly it is divided into 100 parts.The unit of the non-parallel incident illumination then generated As shown in Figure 8, expression formula is vector:

$\stackrel{\→}{S}(\mathrm{sa},\mathrm{sb},\mathrm{sc})=\left(\stackrel{\→}{L}+\stackrel{\→}{t}\right)/|\stackrel{\→}{L}+\stackrel{\→}{t}|---\left(15\right)$

Wherein, vectorThe circumferential position (0 °～360 °) of point on sun disk plane is described；Vector's It is meant that when incident illumination is unit vector during directional light (i.e. sun cone angle=0 °), its expression formula Can be by elevation angle h of the sun_sWith azimuth p_sUniquely determine:

$\left\{\begin{array}{c}\stackrel{\→}{L}=(a,b,c);\\ a=-\cos \left(h_s\right)\·\sin \left(P_s\right);\\ b=-\cos \left(h_s\right)\·\cos \left(P_s\right);\\ c=-\sin \left(h_s\right).\end{array}---\left(16\right)\right.$

Sun disk model is according to sun altitude h_sWith azimuth p_s(i.e. sunray and Due South Angle, is negative counterclockwise, clockwise for just) uniquely determine, used in whole optimization process too Sun disk model is identical.

(S21) relevant parameter of Jing Chang is calculated

A () calculates reflective vector and the planar process vector of heliostat

The reflective vector of heliostat is by the direction vector at heat extractor center to heliostat center, in this reality Execute and example is unified with planar process vector, the reflective vector of heliostat is melted into unit vector, minute surface per unit system Vector can be represented by the vector sum of incident ray and reflection light.Being reflected towards of the most any heliostat Amount(rox, roy, roz) and normal vector(nx, ny, nz) is respectively as follows:

$\stackrel{\→}{R}=(\mathrm{rox},\mathrm{roy},\mathrm{roz})=(x,y,z-H_c)/\left|R\right|---\left(17\right)$

$\stackrel{\→}{N}=(\mathrm{nx},\mathrm{ny},\mathrm{nz})=(a+\mathrm{rox},b+\mathrm{roy},c+\mathrm{roz})/\left|N\right|---\left(18\right)$

Wherein, | R | is the heliostat center mould to heat extractor center vector；| N | is minute surface normal vector Mould；(0,0,H_c) it is the centre coordinate of heat extractor.

B () calculates the unit reflective vector of incident ray

To any per incident vector, unit reflective vector that it is correspondingCan be by this incidence vector The normal vector of place minute surfaceWithRepresent.Its expression formula is:

$\stackrel{\→}{\mathrm{RS}}=2\·\stackrel{\→}{N}\·\left(\stackrel{\→}{S}\·\stackrel{\→}{N}\right)-\stackrel{\→}{S}---\left(19\right)$

C () calculates the apex coordinate of heliostat

Heliostat is generally twin shaft heliostat.As shown in Figure 9: a longitudinal bracing axle axle A, connect Heliostat minute surface center and the fixed position on ground so that during heliostat spin, keep center, ground and mirror Center, face is fixed；Be backed with a cross-brace axle axle B at heliostat, axle B cross minute surface center and with Minute surface normal vector is vertical, keeps minute surface center to fix and minute surface is rotated around axle B during spin.By fixed The twin shaft structure of solar eyepiece can obtain, and two limits of the heliostat being parallel to axle B keep flat with ground all the time OK.

In the present embodiment, apex coordinate is described by the way of coordinate rotates.As shown in Figure 10, Set up heliostat coordinate system, with the center of heliostat as initial point, so that heliostat to be parallel to east-west direction Limit be X-axis, in heliostat, be parallel to the limit of North and South direction as Y-axis, with the normal of heliostat Direction is Z axis, and X-axis positive direction is west, and Y-axis positive direction is south, and Z axis positive direction is vertical minute surface Upwards.In heliostat coordinate system, according to size (the i.e. long l of heliostat of heliostat_mWith wide w_m), Determine centre coordinate O'(x, the y of heliostat, and z) ' for O'(0,0,0), four apex coordinates are respectively P₁'(-l_m/2,w_m/ 2,0), P₂'(l_m/2,w_m/ 2,0), P₃'(l_m/2,-w_m/ 2,0), P₄'(-l_m/2,-w_m/2,0)。 By rotation formula by the Coordinate Conversion on lower for heliostat coordinate system four summits to earth coordinates (such as figure Shown in 1) under, then the i-th summit of heliostat is represented by earth coordinates:

P_i=(x, y, z) '+Rxyz P_i', i=1,2,3,4, (20)

Wherein, Rxyz is spin matrix, according to formula:

Rxyz=Rot (-p_m,z)·Rot(0,y)·Rot(h_m-90, x) (21)

Ask for, wherein h_mAnd p_mIt is elevation angle and the azimuth of every heliostat respectively, function Rot(a, B), representing and rotate around b axle, the anglec of rotation is a, then have:

$\mathrm{Rxyz}=\left[\begin{array}{ccc}\cos \left(p_m\right)& \sin \left(h_m\right)\sin \left(p_m\right)& \sin \left(p_m\right)\cos \left(h_m\right)\\ -\sin \left(p_m\right)& \sin \left(h_m\right)\cos \left(p_m\right)& \cos \left(p_m\right)\cos \left(h_m\right)\\ 0& -\cos \left(h_m\right)& \sin \left(h_m\right)\end{array}\right].---\left(12\right)$

D () calculates heliostat center and summit, each summit and sits along incident ray projection on the ground Mark

In three dimensions, be equivalent to calculate the intersection point of straight line and plane, then heliostat center and four Summit coordinate on the ground is respectively (x_os,y_os) and (x_psi,y_psi), wherein:

x_os=-(a/b) z+x, y_os=-(b/c) z+y (23)

x_psi=-(a/b) z_pi+x_pi,y_psi=-(b/c) z_pi+y_pi(24)

I=1,2,3,4, represent four summit sequence numbers, x respectively_pi,y_pi,z_piIt is respectively the i-th of heliostat Summit is the coordinate figure of x-axis, y-axis and z-axis in earth coordinates.

(S22) Monte Carlo Ray-tracing Method is utilized to calculate the integrated optical efficiency of generated Jing Chang

Cosine efficiency, atmospheric transmission efficiency, shadow occlusion efficiency are multiplied with overflowing efficiency and get final product Integrated optical efficiency to generated Jing Chang.

Cosine efficiency and atmospheric transmission efficiency have only to determine minute surface centre coordinate, position of sun and connecing Receiving tower position can ask for, circular can be found in the patent literary composition of Publication No. 102519152A Offer.

Shadow occlusion efficiency is relevant with the relative position of heliostat with spilling efficiency, utilizes Monte Carlo light Line trace following method calculates the shadow occlusion efficiency of generated Jing Chang respectively and overflows efficiency, specifically calculates process As follows:

A () determines that scope is spread in throwing, throw and spread random luminous point

Dynamic tracking heliostat summit and centre coordinate are along incident illumination view field on the ground, really Determine throwing and spread scope, utilize Monte Carlo method to throw at random and spread luminous point and throwing is spread luminous point quantity and should be tried one's best many, many To the view field that can be formed completely on the ground with all minute surfaces of covering Jing Chang, projection on the ground The coordinate of luminous point is represented by:

$\begin{array}{c}\mathrm{Xis}=x_{\min }+(x_{\max }-x_{\min })*\mathrm{rand}(N,1)\\ \mathrm{Yis}=y_{\min }+(y_{\max }-y_{\min })*\mathrm{rand}(N,1)\end{array}---\left(25\right)$

Wherein, x_min,x_maxIt is respectively the minimum that heliostat apex coordinate projects on the ground along incident illumination With maximum X-coordinate value, y_min,y_maxIt is respectively heliostat apex coordinate to project on the ground along incident illumination Minimum and maximum Y-coordinate value, N is that spot number is spread in throwing, and rand (N, 1) represents that stochastic generation is N number of (0,1) random number between.

B () utilizes Ray-tracing Method, follow the trail of the movement locus of each light, it is judged that each light Line and each heliostat or the crossing situation of heat extractor, effective computational shadowgraph blocks efficiency and overflows effect Rate.

(S3) calculate land cover pattern rate, and be calculated integrated optical efficiency and land cover pattern further The product of rate, i.e. optimization aim.

(S4) simplex optimization method is utilized to repeat step S1～S3, big by the optimization aim that obtains Little and previous compare, retain higher value, be repeated several times, obtain largest optimization target, and So that during optimization aim maximum, the value of optimized variable is as the optimal value of corresponding optimized variable, i.e. variable is excellent The result changed.

In step (S4), repeatedly circulation carries out step S1～S3, each optimized variable in cyclic process Value different, number of rings JMAX of heliostat and the heliostat of optimized ring in the mirror field every time generated Quantity I MAX_mAlso change is being continued to optimize.

Use and carry out Jing Chang optimization design through suitably modified simplex search algorithm, such as Figure 11 institute Showing, the concrete thought of algorithm is as follows:

(2-1) algorithm initialization.Simplex counting s=0, simplex builds operator v=1, initializes Simplex search algorithm parameter { α, beta, gamma, δ }, wherein α is reflection factor, and β is contraction factor, and γ is Expansion factor, δ is the factor of collapsing；

(2-2) decision condition is initialized: if current v >=n+1(n is optimized variable number), then turn Step (2-4)；Otherwise return and perform step (2-3)；

(2-3) initial simplex builds.Assume under the search upper bound and the search of k-th optimized variable Boundary is respectivelyWith(in the present embodiment, optimized variable is the radial spacing coefficients R of adjacent ring_coefWith The circumferential spread ratio A of adjacent heliostat on same ring_coef), then to initial pointUse sequential perturbation Method builds initial simplex, if τ is the perturbation factor, ifPerturb the most to the right ${\stackrel{\‾}{X}}^{k+1}={\stackrel{\‾}{X}}^1+\mathrm{\τ}{e}_k$ ；Otherwise, perturb the most to the left ${\stackrel{\‾}{X}}^{k+1}={\stackrel{\‾}{X}}^1-{\mathrm{\τe}}_k.$ Make k=k+1, v=v+1, $V_v^0={\stackrel{\‾}{X}}^k.$ The perturbation schematic diagram that initial simplex builds is as shown in figure 12.

(2-4) simplex summit sequence.By the summit of simplexGenerated The average annual optics rate of the response value that mirror field is corresponding, i.e. optimization aim: Jing Chang and taking advantage of of land cover pattern rate It is long-pending,Size be ranked up, V₁ ^sRepresent smallest point,Represent distance A little louder,Represent secondary a little bigger.Make V^s+1=V^s, F^s+1=F^s, s=s+1；

(2-5) reflection: according toProduce reflective operation pointWhereinMake k=k+1,If Y_ref＜ F₁ ^s, perform step (2-6) Perform expansive working；If, go to step (2-7), perform shrinkage operation；In the case of other, Use V_refReplace V_n+1, Y_refReplaceReturn and perform step (2-4)；

(2-6) expand: according toProduce expansion pointK=k+1, $Y_{\exp }={\stackrel{\‾}{Y}}^k;$

If Y_exp≤Y_ref, useReplaceReturn and perform step (2-4)；

Otherwise, useReplace Return and perform step (2-4)；

(2-7) shrink: according to formulaProduce constriction pointWherein when $Y_{\mathrm{ref}}>F_{n+1}^k,V_{\max /\mathrm{ref}}^s=V_{n+1}^s,F_{\max /\mathrm{ref}}^s=F_{n+1}^s;$ Otherwise, $V_{\max /\mathrm{ref}}^s=V_{\mathrm{ref}}^s,F_{\max /\mathrm{ref}}^s=Y_{\mathrm{ref}}$ .Make k=k+1,After contraction, compare constriction point and shrink reference pointIf WithReplace Return and perform step (2-4)；Otherwise, perform step (2-8) to hold Capable operation of collapsing, if v=2；

(2-8) collapse: perform to collapse operationK=k+1, v=v+1, As v >=n+1, return and perform step (2-4)；Otherwise continue step (2-8).

The optimal value of each optimized variable is obtained, as shown in table 2 by optimization.

Table 2 variable optimum results

(3) result optimized according to variable, carries out radial pattern mirror field layout.As shown in figure 13, should Radial pattern Jing Chang has 7 rings, and the radius (the first ring is to the 7th ring) of each ring is respectively as follows: 30m, 31.9m, 33.3m, 35.3m, 36.6m, 38.9m, 40.6m, the circumferential angular separation of the adjacent heliostat on each ring is divided It is not: 0.0558,0.0563,0.0476,0.0429,0.05166,0.0462,0.0411 that unit is radian, Heliostat quantity on each ring is respectively 55,54,65,72,59,68,75.

Result shows, the integrated optical efficiency of the little Jing Chang after optimizing has reached 82.5%, with one As compare higher than the integrated optical efficiency (about 70%) of Jing Chang of tower type solar thermoelectricity system, improve About 12%., and the land cover pattern of the Jing Chang according to the mirror field Optimization Design layout of the present embodiment Rate is 33.6%.

Claims (8)

1. a mirror field Optimization Design for radial pattern tower type solar thermoelectricity system, its feature exists In, comprise the following steps:

(1) determine radial pattern Jing Chang radial spacing coefficient and circumference spread ratio be optimized variable, And determine the search bound of each optimized variable respectively；

(2) using the product of integrated optical efficiency and land cover pattern rate as optimization aim, according to Jing Chang The search bound of parameter, sun disk model and each optimized variable, uses simplex algorithm to become Amount optimizes, and obtains the optimal value of each optimized variable, and described optimal value makes optimization aim take maximum；

(3) optimal value of each optimized variable obtained according to step (2), carries out radial pattern tower too The mirror field layout of sun energy heat and power system；

Integrated optical efficiency is cosine efficiency, shadow occlusion efficiency, overflows efficiency, atmospheric transmission efficiency Product；

Land cover pattern rate is the gross area ratio with given land area of heliostat.

2. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 1 optimizes design Method, it is characterised in that in described step (1), radially the search bound of spread ratio is [0,1].

3. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 2 optimizes design Method, it is characterised in that in described step (1), the search bound of circumference spread ratio is [0,1].

4. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 3 optimizes design Method, it is characterised in that the mirror field parameters in described step (2) includes size and the soil of heliostat Ground area.

5. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 4 optimizes design Method, it is characterised in that the sun disk model of described step (2) uses Monte Carlo to spread a method Simulate the foundation of its energy-flux density to obtain.

6. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 5 optimizes design Method, it is characterised in that the sun disk model in described step (2) is non-parallel incident optical mode Type.

7. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 6 optimizes design Method, it is characterised in that use Monte Carlo Ray-tracing Method to calculate Jing Chang in described step (2) Integrated optical efficiency.

8. the Jing Chang of radial pattern tower type solar thermoelectricity system as claimed in claim 7 optimizes design Method, it is characterised in that calculate platform based on CUDA in described step (2) and carry out variable optimization.