CN102519154A - Track-free two-dimensional solar light concentrating device - Google Patents

Abstract

A track-free two-dimensional solar light concentrating device comprises a support, a modified parabolic reflector and a vacuum heat absorbing tube. The modified parabolic reflector is a reflecting surface, a function is adopted as a generating line, the reflecting surface is obtained by means of moving the generating line along a Z-axis direction, wherein p is a constant with a value ranging from 250 to 500, and the function is a linear function. When an incident angle formed by incident light and a y-axis is changed between 0 degree and 50 degrees, a light concentration range is three to four times larger than a circular area of the p. A light receiving angle of an integral heat collecting device is increased by means of changing the shape of the surface, and round-the-clock track-free solar energy collection is realized. The standard adjustable support is used, one-step installation is realized according to dimensions and positions, and tracking can be omitted all the year around. Compared with light concentrators such as a CPC (compound parabolic concentrator) and the like, the track-free two-dimensional solar light concentrating device is higher in concentrating ratio, simpler in manufacture and lower in cost. In addition, units of the integral heat collecting device can be connected in series or parallel in the west-east direction, and integration of a system is realized. Besides, the track-free two-dimensional solar light concentrating device can be used for solar seawater desalination, solar water heaters, solar water boilers, solar air heaters and the like.

Description

A kind ofly exempt to follow the tracks of the two-dimensional solar energy beam condensing unit

Technical field

The present invention relates to a kind of two-dimensional solar energy beam condensing unit of exempting to follow the tracks of, particularly a kind of tracing collection heat collector mechanism that exempts from belongs to technical field of solar utilization technique.

Background technology

The solar energy utilization be field of renewable energy technology commercialization degree higher, apply one of the most general technology.As new forms of energy, solar energy has advantages such as environmental protection sustainable use, and in solving the traditional energy crisis, the solar energy utilization is the competitively focuses of R and D of various countries.China's solar energy year irradiation total amount surpasses 5000 megajoules for every square metre, and the area that year sunshine time surpassed more than 2200 hours accounts for more than 2/3 of area.This is the most favourable external objective condition of solar energy industry development, and enterprise of domestic existing thousands of family sets foot in the solar energy industry.Yet; Solar energy not only is that a kind of energy-flux density is low, radiation has intermittence, spatial distribution but also the energy that constantly changes; East went out the west and fell daytime, and do not have night, and different and season, the different sun elevation angle was also inequality with latitude; With conventional energy resource very big difference is arranged, this just has higher requirement to the collection and the utilization of solar energy.Now to have that the unit volume dielectric capacity is big, temperature raises slow, the thermal source grade is low, can not obtain problems such as high-temperature fast for solar thermal utilization.

Conventional solar energy vacuum tube heat collector collecting efficiency is low; Be different from solar water heater; Under normal operation, system is difficult to 100 ℃ of aqueous medium thermals source are provided fast, even the single tube thermal-arrest also needs more than three hours sometimes under sunshine in the summer good condition; If heat collection water tank is bigger, provide 100 ℃ thermal source difficult more.If solar thermal collection system is used for solar seawater desalination, it can not evaporate the water under normal pressure at all, and also being difficult to provides high-temperature hot air fast, has so directly limited the application at aspects such as desalinizations.High temperature solar heat collecting system is very necessary in the exploitation.

The tracing collection system effectiveness is than no tracking system height, and instantaneous slot light collection effect is more effective than CPC, because it can focus on focusing surface on a point or the line in theory.Can for systems such as solar seawater desalination, solar boiler, solar air heat collection provide fast in warm source.

The temperature that can solve Photospot solar rise slow and the problem that the high-grade thermal source is provided are owing to can provide incident light source very on a large scale than the big a lot of caustic surface of heat-absorbent surface area, so can be with concentration of energy than the zonule.The exemplary of this caustic surface is exactly a parabola optically focused; And the precondition of parabola optically focused acquisition high concentration ratio is that incident ray is parallel with parabolical axle; Will disperse if depart from the certain angle caustic surface, being embodied in the reality is exactly that the optically focused hot spot may not drop on the heat-absorbent surface.In order to address this problem, adopt one dimension or two-dimentional synchronous sun tracking orientation usually, this can increase beam condensing unit complexity and cost of investment.And mainly there is the relatively lower problem of optically focused in known CPC optically focused, if large tracts of land optically focused adopts the CPC mode, according to the light-receiving tube radius, needs parallel connection of a lot of CPC reflecting surface or series operation.High concentration ratio is exempted from very necessity of tracing collection device.

Summary of the invention

The present invention seeks to solve existing solar-energy light collector complex structure, cost of investment height and the lower problem of optically focused, a kind of non-track type modification parabolic condenser is provided, realize exempting to follow the tracks of the solar light collection of high concentration ratio.

Provided by the inventionly exempt to follow the tracks of the two-dimensional solar energy beam condensing unit, comprise support, modification parabolic mirror and the vacuum heat absorbing pipe installed on the support; Described modification parabolic mirror is to be bus with function

; Move the reflecting surface that obtains along the z direction of principal axis, wherein, p is a constant; Span is between 250～500; Paraboloidal focus is between 250mm～500mm at this moment, and the axial distance of z is generally at 1000mm～2000mm, and kx is a linear function; The k value (0,1] between value.

The incidence angle that constitutes when incident ray and y axle is when 0～50 ° changes, and the optically focused scope is at the border circular areas of 3～4 times of p.

Advantage of the present invention and good effect:

(1) through the change of opposite type, make the light receiving angle of whole heat collector become big, realized that the whole day of collection solar energy is exempted to follow the tracks of.The matching standard adjustable trestle according to the Position Latitude once mounting, can be realized exempting from the whole year following the tracks of.

(2) compare with concentrator such as CPC, caustic surface proposed by the invention has higher optically focused ratio when increasing condensing angle, and makes simply relatively, and cost is lower.

(3) whole heat collector can be realized units in series, parallel connection use at east-west direction, realizes the system integration.Can be used for solar energy sea water (bitter) desalination solar water heater, solar boiler, solar air heater etc.

Description of drawings

Fig. 1 exempts to follow the tracks of two-dimensional solar energy beam condensing unit sketch map,

1 is the modification parabolic mirror among the figure, the 2nd, and vacuum heat absorbing pipe, the 3rd, support, the 4th, adjustment supporting leg, the 5th, fixing rotatable connecting bolt, the 6th, removable connecting bolt.

Fig. 2 is the curve map of different function expressions, and 7 function expression does among the figure 8 function expression does

10 function expression does

9 function expression does $y=\frac{1}{2000}{x}^2+\frac{1}{100}x.$

Fig. 3 is the parabolic schematic three dimensional views of modification.

According to summary of the invention, below in conjunction with accompanying drawing and embodiment, specific embodiments of the invention describes in further detail.

The specific embodiment

Embodiment 1:

Practical implementation is following:

Provided by the invention to exempt to follow the tracks of the two-dimensional solar energy beam condensing unit as shown in Figure 1, comprises support 3, modification parabolic mirror 1 and the vacuum heat absorbing pipe 2 installed on the support.Modification parabolic mirror 1 is chosen modification parabolic function

shown in curve among Fig. 28; With above-mentioned curve along z direction of principal axis stretching certain distance; The preferred 1000mm of this instance; The entire emission face thickness is between 3mm～5mm; The preferred 4mm of this instance just obtains a slot type modification parabolic mirror.Here, the length of speculum is 1000mm, and A/F is 500mm.

Embodiment 2:

Choose modification parabolic function

shown in curve among Fig. 29; With above-mentioned curve along z direction of principal axis stretching certain distance; The preferred 1000mm of this instance; The entire emission face thickness is between 3mm～5mm; The preferred 4mm of this instance just obtains a slot type modification parabolic mirror.Here, the length of speculum is 1000mm, and A/F is 500mm.

For the receiving angle that the modification parabolic mirror better is described becomes big, provide two groups of comparative examples below and describe.

Comparative example 1:

Choose parabolic function

shown in the curve among Fig. 27; This moment, parabolic focus was at x=0, y=250mm place; With above-mentioned parabola along z direction of principal axis stretching certain distance; The preferred 1000mm of this instance; The entire emission face thickness is between 3mm～5mm, and the preferred 4mm of this instance just obtains a groove type paraboloid speculum.Here, the length of speculum is 1000mm, and A/F is 500mm.

Comparative example 2:

Choose parabolic function

shown in the curve among Fig. 2 10; This moment, parabolic focus was at x=0, y=500mm place; With above-mentioned parabola along z direction of principal axis stretching certain distance; The preferred 1000mm of this instance; The entire emission face thickness is between 3mm～5mm, and the preferred 4mm of this instance just obtains a groove type paraboloid speculum.Here, the length of speculum is 1000mm, and A/F is 500mm.

In implementation process, adopt Tracepro optics trace software to carry out analog simulation, be provided with and receive the pipe reception light that speculum reflected, verify the efficiency of light energy utilization of each embodiment when difference half acceptance angle incident, the result is as shown in table 1,

	0°	10°	20°	30°
					Comparative example 1	100％	97.6％	90.4％	58.2％
Comparative example 2	100％	82.7％	70.1％	0
					Embodiment 1	100％	100％	100％	88.1％
Embodiment 2	100％	97.8％	62.2％	70％

Table 1

Can find out that from table 1 comparative example 1 is 0 ° with two kinds of parabolic mirrors in the comparative example 2 in incidence angle, when promptly incident ray is parallel to parabolic symmetry axis; Institute's reflection ray all can reach the receiving tube surface, and when incident angle increased, the efficiency of light energy utilization began to descend; Among two embodiment, the spotlight effect of the modification parabolic mirror among the embodiment 1 is comparatively desirable, and incidence angle is in the time of 0 °～20 °; The efficiency of light energy utilization is all higher; During 30 ° of incidents, descend to some extent, but still can satisfy the use of whole concentrator.

According to analog result; Select the effect modification parabolic mirror among the embodiment 1 preferably; As shown in Figure 1, support (3) is different according to the infield latitude, and interlock is installed the fixing rotatable connecting bolt (5) of adjustment supporting leg (4) and removable connecting bolt (6) so that the elevation angle is consistent with local latitude.When track of sun is radiated at the axial curved surface caustic surface of special-shaped parabola (1) from the east to the west; The sun elevation angle is elevated to gradually and reaches maximum noon; And then fall gradually, in the rising or the 50 ° of scopes that descend, the optically focused hot spot is always in the surface range of endothermic tube (2); Once mounting is accomplished like this, and throughout the year any of spring, summer, autumn and winter has the time of the whole day that shines upon about 85% can carry out optically focused.

Claims (1)

1. exempt to follow the tracks of the two-dimensional solar energy beam condensing unit for one kind, comprise support, modification parabolic mirror and the vacuum heat absorbing pipe installed on the support; It is characterized in that described modification parabolic mirror is is bus with function

; Move the reflecting surface that obtains along the z direction of principal axis, wherein, p is a constant; Span is between 250～500; Kx is a linear function, the k value (0,1] between value.

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