Large-capacity high-concentrating ratio composite Fresnel line concentration reflection device

Abstract

The invention relates to a solar heat collector with a focusing element, and in particular relates to a large-capacity high-concentrating ratio composite Fresnel line concentration reflection device. The large-capacity high-concentrating ratio composite Fresnel line concentration reflection device is structurally characterized in that a main reflection device comprises a plurality of microarc Fresnel reflection lenses which are used as main reflection mirrors, a steering device is arranged at the center of each Fresnel reflection lens, the plurality of Fresnel reflection lenses are positioned above a heat collection pipe and distributed in an arc shape by taking the heat collection pipe as a circle center, the large-capacity high-concentrating ratio composite Fresnel line concentration reflection device further comprises an auxiliary reflection device which is arranged under the heat collection pipe, and an arc-shaped convex surface (concentrating surface) faces towards the direction of the heat collection pipe. The large-capacity high-concentrating ratio composite Fresnel line concentration reflection device has the advantages of obtaining larger ground utilization ratio, adequately considering the incident conditions of sunshine, greatly reducing the sunshine loss, improving the heat collection effect of the heat collection pipe, realizing good focusing effect as well as effect of leading the heat collection pipe to be evenly heated, and showing the large-capacity concentrating effect.

Description

technical field [0001] The invention relates to a solar heat collector with focusing elements, in particular to a large-capacity and high-concentration-ratio composite Fresnel line light-concentrating reflector. Background technique [0002] The Fresnel lens has the function of concentrating light. In the application of large-scale concentrating devices for solar thermal power generation, reflective Fresnel equipment is mainly used. There are many types of Fresnel reflectors in the prior art, such as the widely used compact linear Fresnel reflector (CLFR for short), which consists of a plurality of compactly arranged Fresnel reflectors distributed below mirror and the solar collector tube above, refer to the patent ZL200880112788.8; there is also a parabolic trough concentrating device, which is also a commonly used solar thermal power concentrating device, the reflector used is parabolic, and the concave surface faces the direction of the sun A solar collector tube is set ...

AI Technical Summary

Problems solved by technology

[0003] Yet the existence of above-mentioned concentrating device has many weak points: the capacity of tower type concentrating device and parabolic dish type concentrating device is little, and the capacity of parabolic trough type concentrating device is higher than tower type concentrating device and parabolic dish type concentrating device. The large one is the commonly used one at present, but it usually does not exceed 100MW, and the capacity of CLFR can be made larger and the cost is lower, but the CLFR with large capacity has the following problems:

[0005] Secondly, the radian of the reflector of CLFR is not adjustable at present. 1. The reflector in the middle part is relatively close to the heat collecting tube, while the reflectors on both sides are far away from the heat collecting tube. If all the reflectors have the same radian, it is bound to be There will be some reflectors with poor focusing effect; 2. Although the reflector can rotate with the change of sunlight angle, the distance between the center of the reflector and the center of the heat collector tube is constant, but the focal length of the reflector varies with the incident angle of sunlight. position will change, as attached figure 2 And attached image 3 , when the sunlight and the reflector form an angle of 30° (see attached image 3 ), its focusing distance (the distance from the center of the reflector to the center of focus) is only when the sunlight is perpendicular to the reflector (see attached figure 2 ) half

[0006] In addition, the heat collecting tube of CLFR is only heated on one (lower) side, and the heating is uneven, which affects the temperature and heat absorption of the heat collecting tube

[0007] The double-reflected Fresnel line concentrating reflector can reduce the loss of sunlight, but only at the collector, the reflector has the same problems as CLFR, resulting in a limited degree of improvement, and the improvement effect is uncontrollable, that is, different The incident angle of sunlight is different. In fact, if the concentration is accurate, the secondary reflection device is not needed, but it is difficult to achieve a horizontally arranged reflective lens, unless the curvature of the reflective lens changes when the reflection angle changes. The upper part of the reflector will also block the sunlight

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