阅读说明：本技术 非平面塔式太阳能吸热屏及吸热器 (Non-planar tower type solar heat absorption screen and heat absorber ) 是由 肖刚 曾季川 倪明江 岑可法 骆仲泱 于 2020-05-26 设计创作，主要内容包括：本发明提供了非平面塔式太阳能吸热屏,包括上集箱、下集箱、通过连接管与上/下集箱连通的吸热管、包覆在上/下集箱外周的集箱保温元件及设置在吸热管背光面的吸热管保温元件,所述吸热管分为两段,上段为直管,下段为弧形管,所述吸热管成排紧密布置,每一根吸热管的弧形管曲率相同,所述吸热管向外弯曲侧为受光面；所述集箱保温元件,为围绕于上/下集箱的四周的多层壳体,由外到内分别为外壳、隔热层、密封层和壁挂式电热辐射板,所述吸热管保温元件为多层结构,由内到外依次为金属板、加热电缆和保温层。该吸热屏下部呈曲面,避免了防护装置对吸热屏下部的遮挡,增大受光面比例,弧形的设计可以缓解吸热管由于受热在竖直方向上的膨胀。(The invention provides a non-planar tower type solar heat absorption screen, which comprises an upper header, a lower header, heat absorption pipes communicated with the upper header and the lower header through connecting pipes, header heat insulation elements coated on the periphery of the upper header and the lower header, and heat absorption pipe heat insulation elements arranged on the backlight surface of the heat absorption pipes, wherein the heat absorption pipes are divided into two sections, the upper section is a straight pipe, the lower section is an arc pipe, the heat absorption pipes are closely arranged in rows, the curvature of the arc pipe of each heat absorption pipe is the same, and the outwards bent side of each heat absorption pipe is a light receiving surface; the heat-insulating element of the header is a multilayer shell surrounding the periphery of the upper/lower header, and comprises a shell, a heat-insulating layer, a sealing layer and a wall-mounted electrothermal radiation plate from outside to inside respectively, and the heat-absorbing pipe heat-insulating element is of a multilayer structure and comprises a metal plate, a heating cable and a heat-insulating layer from inside to outside in sequence. This heat absorption screen lower part is the curved surface, has avoided protector to shelter from to heat absorption screen lower part, increases the sensitive surface proportion, and the expansion of heat absorption pipe in vertical direction owing to being heated can be alleviated in curved design.)

1. Non-planar tower solar heat absorption screen, including last header (11), lower header (12), through connecting pipe (14) and last/heat absorption pipe (13) of header intercommunication down, the cladding is at header heat preservation component (15) of header periphery under/and sets up heat absorption pipe heat preservation component (16) in heat absorption pipe (13) shady face, its characterized in that: the heat absorption pipe (13) is divided into two sections, the upper section is a straight pipe (131), the lower section is an arc pipe (132), the heat absorption pipes (13) are closely arranged in rows, and the outward bending side of the heat absorption pipes (13) is a light receiving surface; the heat-insulating element (15) of the header is a multilayer shell surrounding the periphery of the upper/lower header and is composed of a shell (151), a heat-insulating layer (152), a sealing layer (153) and a wall-mounted electrothermal radiation plate (154) from outside to inside, and the heat-insulating element (16) of the heat absorption tube is of a multilayer structure and is composed of a metal plate (161), a heating cable (162) and a heat-insulating layer (163) from inside to outside in sequence.

2. The non-planar tower solar thermal panel of claim 1, wherein: the connecting points of the connecting pipes (14) and the upper/lower header are distributed along the length direction of the header at intervals in a staggered manner; the connecting points with odd numbers are positioned on the same straight line, the connecting points with even numbers are positioned on the same straight line, and the two straight lines are parallel and have a certain distance.

3. The non-planar tower solar thermal panel of claim 1, wherein: the arc-shaped pipe (132) is divided into three sections, the joint of the two ends is arc-shaped, and the middle is a straight line.

4. The non-planar tower solar thermal panel of claim 1, wherein: the arc-shaped pipe (132) is arc-shaped, the upper end of the arc-shaped pipe is tangent to the straight pipe (131), the direction of the tangent line of the joint of the lower end of the arc-shaped pipe and the connecting pipe (14) of the lower header (12) is inclined towards the lower side, and the central angle of two ends of the arc-shaped pipe (132) relative to the circle center is 60-90 degrees.

5. The non-planar tower solar thermal panel of claim 1, wherein: the light receiving surface of the heat absorption tube (13) is coated with a high-temperature resistant selective absorption coating.

6. The non-planar tower solar thermal panel of claim 1, wherein: and the heat insulation layer (152) of the header heat insulation element (15) and the heat insulation layer (163) of the heat absorption pipe heat insulation element (16) are made of aluminum silicate heat insulation cotton with the heat conductivity coefficient of less than 0.12W/(m.K).

7. The non-planar tower solar thermal panel of claim 1, wherein: the wall-mounted electrothermal radiation plate (154) is circumferentially arranged in the header heat-insulating element (15) and fixed on the shell (151) through a metal bracket (155), and the heating mode is infrared radiation heating.

8. The non-planar tower solar thermal panel of claim 1, wherein: the sealing layer (153) is made of a waterproof material, and a high-reflection coating is coated on the surface of the sealing layer (153) facing the upper/lower header side.

9. The non-planar tower solar thermal panel of claim 1, wherein: the metal plate (161) of the heat absorption pipe heat preservation element (16) is arranged close to the backlight surface of the heat absorption pipe (13), a high-reflection coating is coated on one side of the metal plate close to the heat absorption pipe (13), and the heating cable (162) is uniformly arranged on one side, far away from the heat absorption pipe (13), of the metal plate (161) in a wave shape.

10. A non-planar tower solar heat absorber, characterized in that a non-planar tower solar heat absorber screen according to any of claims 1-9 is used: the non-planar tower type solar heat absorption screen comprises a plurality of non-planar tower type solar heat absorption screens, wherein the plurality of non-planar tower type solar heat absorption screens are annularly arranged to form a heat absorber similar to a cylinder, and the center line of an upper header of each non-planar tower type solar heat absorption screen is farther from the center of the heat absorber than the center line of a lower header of each non-planar tower type solar heat absorption screen.

Technical Field

The invention relates to the technical field of tower type solar heat absorber design, in particular to a non-planar tower type solar heat absorption screen and a heat absorber.

Background

Solar energy is a renewable energy source, and has the advantages of unlimited reserves, universality, cleanness in use, economical utilization and the like: the energy emitted by the sun every second is about 1.6 × 1023 kw, and the total amount of solar energy reaching the earth surface in one year is reduced to about 1.892 × 1013 billion t of standard coal, which is ten thousand times the main energy source proven reserves in the world at present. At present, the solar energy utilization mode mainly comprises solar photovoltaic power generation and solar photo-thermal power generation. In solar photo-thermal power generation, according to the form of light condensation, the power generation technology can be divided into: tower type, groove type, disc type and linear Fresnel type.

Aiming at a tower type solar thermal power generation system, a heat absorber is an extremely important component of the whole system, and can convert high-energy current density radiant energy reflected by a heliostat system into high-temperature heat energy of a heat transfer working medium. The heat absorber can be divided into a tubular heat absorber and a positive displacement heat absorber according to the difference of the structure. Wherein, the tubular heat absorber can be divided into an exposed tubular heat absorber and a cavity tubular heat absorber.

At present, protective bricks are arranged at the upper end and the lower end of an exposed tower type solar molten salt heat absorber, because inlet and outlet headers of each heat absorption screen are arranged at the positions of the upper end and the lower end of the heat absorber. The heat absorber is generally arranged at 200 meters high altitude, the environmental condition is severe, and high wind speed can cause huge heat dissipation. In order to prevent the phenomenon of molten salt solidification at the inlet and the outlet of the header, the inlet and the outlet of the header are required to be ensured to be in a proper temperature range, so that heat preservation devices are required to be arranged around the inlet and the outlet of the header; meanwhile, in order to avoid direct irradiation of sunlight reflected by a heliostat field to the heat preservation equipment, a layer of protective brick is additionally arranged on the outer side of the heat preservation element. Although the arrangement can effectively ensure the temperature of the inlet and outlet header, the overall size of the heat preservation equipment is greatly increased, and the specific expression is that the positions of the heat preservation equipment and the protective bricks are more convex compared with the light receiving surface of the heat absorption screen, which can influence the light receiving effect of the heat absorption screen.

In actual operation, especially during warm-up, the sunlight reflected from the heliostat field will strive to strike every part of the receiver surface of the heat absorber screen in order to achieve a higher temperature across the receiver surface of the absorber. However, for the lower end of the light receiving surface of the heat absorbing screen, the projected heat preservation equipment and the protective bricks can partially shield sunlight reflected by the heliostat field, so that the lower end of the light receiving surface of the heat absorber cannot receive the sunlight, and further cannot reach an ideal temperature, and the phenomenon that molten salt is solidified in the sunlight can be caused, and the safe operation of the whole tower type solar thermal power station is damaged. The heat absorber which is free from shielding the lower end of the light receiving surface of the heat absorbing screen, can prevent the blockage caused by the condensation of the molten salt in the pipeline of the heat absorber, has longer service life and better safety is urgently needed to be developed.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides the non-planar tower type solar heat absorption screen, the position of the lower header is moved to the inside of the heat absorber by the heat absorption screen, the lower heat absorption screen is a convex curved surface, the shielding of a protection device on the lower part of the heat absorption screen in the traditional heat absorption screen structure is avoided, the proportion of a light receiving surface is increased, and the heating surface of the heat absorption screen can reach the ideal temperature during preheating; the addition of the arc-shaped pipeline on the lower part of the heat absorption pipe enables the light receiving area of the heat absorption screen to be increased, full heat exchange of fused salt in the heat absorption pipe is facilitated, and meanwhile, expansion of the heat absorption pipe in the vertical direction due to heating can be relieved through the arc-shaped design. The application also provides a non-planar tower solar heat absorber.

The non-planar tower type solar heat absorption screen comprises an upper header, a lower header, heat absorption pipes communicated with the upper header and the lower header through connecting pipes, header heat insulation elements coated on the peripheries of the upper header and the lower header and heat absorption pipe heat insulation elements arranged on the backlight surfaces of the heat absorption pipes, wherein the heat absorption pipes are divided into two sections, the upper section is a straight pipe, the lower section is an arc pipe, the heat absorption pipes are closely arranged in rows, the curvature of the arc pipe of each heat absorption pipe is the same, and the outward bending side of each heat absorption pipe is a light receiving surface; the heat-insulating element of the header is a multilayer shell surrounding the periphery of the upper/lower header, and comprises a shell, a heat-insulating layer, a sealing layer and a wall-mounted electrothermal radiation plate from outside to inside respectively, and the heat-absorbing pipe heat-insulating element is of a multilayer structure and comprises a metal plate, a heating cable and a heat-insulating layer from inside to outside in sequence.

Compared with the prior art, the non-planar tower type solar heat absorption screen has the following remarkable improvements:

(1) the position of the lower header is moved towards the interior of the heat absorber, so that the shielding of a protective device on the heat absorber screen in the traditional heat absorber screen structure is prevented, the light receiving surface of the whole heat absorber screen can receive the sunlight reflected by the heliostat field, and the heating surface of the heat absorber screen can reach the ideal temperature during preheating;

(2) the addition of the arc-shaped pipeline on the lower part of the heat absorption pipe enables the light receiving area of the heat absorption screen to be increased, full heat exchange of fused salt in the heat absorption pipe is facilitated, and meanwhile, expansion of the heat absorption pipe in the vertical direction due to heating can be relieved through the arc-shaped design.

As optimization, the connecting points of the connecting pipes and the upper/lower header are distributed at intervals in a staggered manner along the length direction of the header; the connecting points with odd numbers are positioned on the same straight line, the connecting points with even numbers are positioned on the same straight line, and the two straight lines are parallel and have a certain distance.

According to the optimization scheme, the adjacent connection points are distributed in a staggered manner, so that the situation that the distance between the connection points is too close to influence the strength of the header can be prevented, and a welding gun operation space is reserved for welding the header and the connection pipe; the tie point is two lines and sets up and is convenient for fix a position and punch.

Preferably, the arc-shaped pipe is divided into three sections, the joint of the two ends is arc-shaped, and the middle part is a straight line.

According to the optimization scheme, the connection parts of the two ends are arc-shaped, so that the installation is convenient, the resistance of the molten salt flowing through the connection parts can be buffered, the straight line illuminated surface in the middle is smoother and uniform, and the heat absorption effect is good.

Preferably, the upper end of the arc-shaped pipe is tangent to the straight pipe, the central angle of the two ends of the arc-shaped pipe relative to the circle center is 60-90 degrees, and the central angle is inclined to the lateral lower part along the direction of the tangent line at the joint of the lower header connecting pipe.

According to the optimization scheme, the arc-shaped pipeline is in tangent connection with the heat absorption pipe straight pipe and the connecting pipe, so that the flow resistance of the molten salt in the pipe is favorably reduced.

Preferably, the light receiving surface of the heat absorption tube is coated with a high-temperature-resistant selective absorption coating.

According to the optimization scheme, the high-temperature-resistant selective absorption coating is coated on the heating surface of the heat absorption tube, on one hand, the absorption effect of the heat absorber on solar radiation is improved, and on the other hand, the coating is prevented from being damaged by high temperature.

As optimization, the heat insulation layer of the heat collection box heat insulation element and the heat insulation layer of the heat absorption pipe heat insulation element are both made of aluminum silicate heat insulation cotton with the heat conductivity coefficient smaller than 0.12W/(m.K).

According to the optimized scheme, the aluminum silicate material has the advantages of small heat conductivity coefficient, less heat dissipation and better heat preservation effect.

Preferably, the wall-mounted electrothermal radiation plate is circumferentially arranged in the header heat-insulating element and fixed on the shell through a metal bracket, and the heating mode is infrared radiation heating.

According to the optimization scheme, the wall-mounted electrothermal radiation plate is parallel to the side surface of the header heat-storage and heat-preservation device, the inner space of the header heat-storage and heat-preservation device can be utilized more reasonably, the area of the wall-mounted electrothermal radiation plate is increased as much as possible, the wall-mounted electrothermal radiation plate and the header are arranged relatively, the wall-mounted electrothermal radiation plate can be used for heating the header, the wall-mounted electrothermal radiation plate and the header can be used for heating a connecting pipe correspondingly arranged with the position of the connecting pipe.

Further, as an optimization, the sealing layer is made of a material having water resistance, and a high-reflection coating is coated on the surface of the sealing layer facing the upper/lower header side.

According to the optimized scheme, the high-reflection coating on the surface of the sealing layer is used for reflecting infrared rays emitted by the wall-mounted electrothermal radiation plate, so that the heating effect of the wall-mounted electrothermal radiation plate is enhanced.

Preferably, the metal plate of the heat-insulating element of the heat-absorbing pipe is arranged close to the backlight surface of the heat-absorbing pipe, one side of the heat-insulating element close to the heat-absorbing pipe is coated with a high-reflection coating, and the heating cable is uniformly arranged on one side of the metal plate far away from the heat-absorbing pipe in a wave shape.

According to the optimized scheme, the metal plate of the heat absorption tube heat insulation element is coated with the high-reflection coating on one side close to the heat absorption tube, sunlight irradiated into gaps of the heat absorption tube can be reflected to the backlight side of the heat absorption tube, the heat absorption area of the heat absorption tube is increased, and the heat absorption tube is heated more uniformly when the heating cable is arranged in a wave shape.

The application also provides a non-planar tower solar heat absorber, adopts the non-planar tower solar heat absorber screen: the non-planar tower type solar heat absorption screen comprises a plurality of non-planar tower type solar heat absorption screens, wherein the plurality of non-planar tower type solar heat absorption screens are annularly arranged to form a heat absorber similar to a cylinder, and the center line of an upper header of each non-planar tower type solar heat absorption screen is farther from the center of the heat absorber than the center line of a lower header of each non-planar tower type solar heat absorption screen.

Compared with the prior art, the non-planar tower type solar heat absorber lower header is closer to the inside of the cylindrical frame of the heat absorber relative to the position of the upper header, the light receiving surface of the heat absorber screen can not be shielded, the heating area of the heat absorber can be improved, no illumination dead angle exists, and the heat absorbing pipe is uniformly heated and is not easy to block.

Drawings

FIG. 1 is a schematic view of a main structure of a heat absorbing panel of the non-planar tower solar heat absorbing panel of the present invention;

FIG. 2 is a schematic structural diagram of the non-planar tower solar heat absorption panel of the present invention at the connection pipe;

FIG. 3 is a side cross-sectional view of a non-planar tower solar thermal panel of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 taken within the dashed box;

fig. 5 is a partially enlarged view of a dotted frame of fig. 3 in embodiment 2.

Description of the reference numerals

11-upper header; 12-lower header; 13-heat absorption tube, 131-straight tube, 132-arc tube; 14-connecting pipe; 15-header insulation element, 151-shell, 152-thermal insulation layer, 153-sealing layer, 154-wall hanging type electrothermal radiation plate, 155-metal bracket; 16-heat absorbing pipe heat preservation component, 161-metal flat plate, 162-heating cable, 163-heat preservation layer.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments (examples), which are described herein for illustrative purposes only and are not intended to be a basis for limiting the present invention.