An insulation device for pipelines inside a solar power tower

Abstract

The present invention discloses a pipeline heat preservation device in a solar power tower. By arranging a heat storage medium part inside the solar power tower body, the heat absorption medium pipeline is wrapped by the heat storage medium therein; an optical path channel is opened on the solar power tower body, and a corresponding heat absorption area is arranged on the heat storage medium part. The secondary reflector performs secondary reflection on the discarded light of the external mirror field, and the discarded light is secondarily reflected to the heat absorption area through the optical path channel. The heat storage medium in the heat storage medium part absorbs and stores the heat energy of sunlight, and the heat accumulated by the discarded light is stored in the heat storage medium. When the heat absorption system stops operating (such as during night and cloudy days, etc.), this part of heat energy can maintain the temperature of the heat absorption medium pipeline, thereby realizing the replacement of the electric tracing equipment. Without energy consumption, the heating and heat preservation of the heat absorption medium pipeline can be completed, solving the problems of high cost and large energy consumption caused by the existing heat absorption medium pipeline using electric tracing equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar thermal power generation, and particularly relates to a pipeline heat preservation device in a heat absorption tower. Background Art

[0002] While the economy is developing continuously, energy is becoming increasingly scarce, traditional non-renewable energy is drying up day by day, economic development is more and more restricted by the development and utilization of energy, the utilization of renewable energy has received widespread attention, especially the utilization of solar energy has attracted more attention from the world.

[0003] In the field of solar thermal power generation, tower-type solar thermal power generation will become the next new energy technology that can be commercially operated due to its advantages such as high solar-thermal conversion efficiency, high focusing temperature, simple installation and commissioning of the control system, and less heat dissipation loss.

[0004] In the field of tower-type solar thermal power generation, heliostats are an important part of the tower-type solar thermal power generation system. As Figure 1 shown, the heliostats reflect sunlight onto the absorber to heat the heat-absorbing working medium, thereby converting light energy into heat energy, and then driving a steam turbine to generate electricity.

[0005] If the tower-type solar thermal power generation system uses molten salt as the medium, the riser and downcomer need to be heated before each operation of the heat absorption system or after the operation ends to ensure that the molten salt medium does not freeze and adhere to the wall in the heat absorption pipeline. The conventional pipeline heating method is electric tracing heating, and the equipment cost of the electric tracing heating method is high, and the energy consumption required during the heating process is large. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a pipeline heat preservation device in a heat absorption tower to solve the problems of high cost and large energy consumption caused by using electric tracing equipment for the existing heat absorption medium pipeline.

[0007] To solve the above problems, the technical solution of the present invention is as follows:

[0008] A pipeline heat preservation device in a heat absorption tower of the present invention includes:

[0009] A heat absorption tower body, on which an optical path channel is provided, and the first end of the optical path channel is communicated with the outside;

[0010] A heat storage medium part, which is arranged inside the heat absorption tower, the heat storage medium part is filled with a heat storage medium, and the heat storage medium wraps the heat absorption medium pipeline inside the heat absorption tower body; a heat absorption area is provided on the heat storage medium part, and the heat absorption area corresponds to the optical path channel;

[0011] A secondary reflector, which is arranged in an external mirror field, and the light reflection direction of the secondary reflector faces the optical path channel for reflecting the discarded light of the external mirror field;

[0012] Under working conditions, the light rejection is reflected by the secondary reflector, and is reflected to the heat absorption area through the optical path channel. The heat storage medium in the heat storage medium part absorbs and stores the heat energy of sunlight to maintain the temperature of the heat absorption medium pipeline.

[0013] For the pipeline heat preservation device in the solar tower of the present invention, the top of the solar tower body is a ring-shaped heat absorber panel; the inner wall surface of the heat absorber panel forms the optical path channel;

[0014] The secondary reflector is arranged above the heat absorber panel.

[0015] For the pipeline heat preservation device in the solar tower of the present invention, a tertiary reflector is arranged on the inner wall surface of the heat absorber panel.

[0016] For the pipeline heat preservation device in the solar tower of the present invention, the secondary reflector is a secondary parabolic reflector, which is used to focus the reflected light rejection in the optical path channel and then diffuse it to the heat absorption area.

[0017] For the pipeline heat preservation device in the solar tower of the present invention, a heat absorption coating is arranged on the heat absorption area.

[0018] For the pipeline heat preservation device in the solar tower of the present invention, the heat storage medium part is a heat storage medium shell, and the inner cavity of the heat storage medium shell is filled with the heat storage medium;

[0019] The surface of the heat storage medium shell facing the optical path channel is the top surface, and a heat absorption groove is formed on the top surface. The inner wall surface of the heat absorption groove is the heat absorption area.

[0020] For the pipeline heat preservation device in the solar tower of the present invention, the top surface is attached to the second end of the optical path channel;

[0021] The bottom surface of the heat storage medium shell extends below the lowest point of the heat absorption medium pipeline in the solar tower body.

[0022] For the pipeline heat preservation device in the solar tower of the present invention, the depth direction of the heat absorption groove is the vertical direction, and the bottom surface of the heat absorption groove is a hemispherical bottom surface arranged in a concave shape.

[0023] For the pipeline heat preservation device in the solar tower of the present invention, the form of the heat storage medium is a solid form or a phase change energy storage form.

[0024] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0025] In an embodiment of the present invention, a heat storage medium part is arranged inside the heat absorption tower body, and the heat absorption medium pipeline is wrapped by the heat storage medium therein; an optical path channel is opened on the heat absorption tower body, and a corresponding heat absorption area is arranged on the heat storage medium part. The secondary reflector reflects the discarded light of the external mirror field for the second time, and the discarded light is reflected to the heat absorption area through the optical path channel. The heat storage medium in the heat storage medium part absorbs and stores the heat energy of sunlight, and the heat accumulated by the discarded light is stored in the heat storage medium. When the heat absorption system stops operating (such as during night and cloudy days, etc.), this part of the heat energy can maintain the temperature of the heat absorption medium pipeline, thereby realizing the replacement of the electric tracing equipment, and the heating and heat preservation of the heat absorption medium pipeline can be completed without energy consumption (one is that it can maintain the heat absorption medium in the heat absorption medium pipeline from condensing, and the other is that it can replace the electric tracing equipment to heat the heat absorption medium in the heat absorption medium pipeline when the system starts), solving the problem that the existing heat absorption medium pipeline using electric tracing equipment has high cost and large energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the pipeline heat preservation device in the heat absorption tower of the present invention.

[0027] Description of the reference numerals: 1: Heat absorption tower body; 2: Heat storage medium part; 3: Heat storage medium; 4: Secondary reflector; 5: Optical path channel; 6: Heat absorber panel; 7: Heat absorption groove; 8: Heat absorption coating; 9: Rising pipe; 10: Downcomer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following further describes in detail a pipeline heat preservation device in a heat absorption tower proposed by the present invention with reference to the drawings and specific embodiments. According to the following description and the claims, the advantages and features of the present invention will be clearer.

[0029] Refer to Figure 1 , in one embodiment, a pipeline heat preservation device in a heat absorption tower includes a heat absorption tower body 1, a heat storage medium part 2 and a secondary reflector 4.

[0030] An optical path channel 5 is provided on the heat absorption tower body 1, and the first end of the optical path channel 5 is communicated with the outside.

[0031] The heat storage medium part 2 is arranged inside the heat absorption tower, the heat storage medium part 2 is filled with a heat storage medium 3, and the heat storage medium 3 wraps the heat absorption medium pipeline inside the heat absorption tower body 1. A heat absorption area is provided on the heat storage medium part 2, and the heat absorption area corresponds to the optical path channel 5.

[0032] The secondary reflector 4 is arranged in the external mirror field, and the light reflection direction of the secondary reflector 4 faces the optical path channel 5, and is used to reflect the discarded light of the external mirror field into the optical path channel 5.

[0033] During operation, the light rejection is reflected by the secondary reflector 4 and then reflected to the heat absorption area through the optical path channel 5 for the second time. The heat storage medium 3 in the heat storage medium section 2 absorbs and stores the solar heat energy to maintain the temperature of the heat absorption medium pipeline.

[0034] In this embodiment, a heat storage medium section 2 is arranged in the heat absorption tower body 1, and the heat absorption medium pipeline is wrapped by the heat storage medium 3 therein. An optical path channel 5 is opened on the heat absorption tower body 1, and a corresponding heat absorption area is arranged on the heat storage medium section 2. The secondary reflector 4 performs a secondary reflection on the light rejection of the external mirror field, and the light rejection is reflected to the heat absorption area through the optical path channel 5 for the second time. The heat storage medium 3 in the heat storage medium section 2 absorbs and stores the solar heat energy, and the heat accumulated by the light rejection is stored in the heat storage medium 3. After the heat absorption system stops operating (such as during night and cloudy days), this part of the heat energy can maintain the temperature of the heat absorption medium pipeline, thereby realizing the replacement of the electric tracing equipment and completing the heating and heat preservation of the heat absorption medium pipeline without energy consumption (one is to maintain the heat absorption medium in the heat absorption medium pipeline from condensing, and the other is to replace the electric tracing equipment to heat the heat absorption medium in the heat absorption medium pipeline when the system starts), solving the problems of high cost and large energy consumption caused by the use of electric tracing equipment for the existing heat absorption medium pipeline.

[0035] The specific structure of the pipeline heat preservation device in the heat absorption tower of this embodiment will be further described below:

[0036] In this embodiment, based on the form of the existing heat absorber panel 6, the present application arranges a ring-shaped heat absorber panel 6 at the top of the heat absorption tower body 1, and the inner wall surface of the heat absorber panel 6 can form the optical path channel 5 required by the present application.

[0037] At this time, the secondary reflector 4 can be arranged above the heat absorber panel 6 to reflect the sunlight transmitted from the lower mirror field to the optical path channel 5 below the secondary reflector 4 for the second time.

[0038] Furthermore, a tertiary reflector can be arranged on the inner wall surface of the heat absorber panel 6, and the tertiary reflector can reflect part of the scattered radiation light three times to a deeper place, so as to ensure that even if there are some deviations in the optical path of the light entering the interior, it can still be reflected to the heat absorption area again.

[0039] In this embodiment, the secondary reflector 4 is a secondary parabolic reflector, and the secondary reflector 4 is set in the shape of a secondary parabola, so that the light rejection reflected for the second time can be focused at a central point position at a certain height in the optical path channel 5 and then diffused to the heat absorption area, so that the heat absorption area can be evenly heated (as shown in Figure 1 , the hatched part in the oblique section is the reflection area of the sunlight).

[0040] Further, in order to ensure a good sunlight absorption efficiency, an absorption coating 8 is provided on the heat absorption area in this embodiment.

[0041] In this embodiment, the above-mentioned heat storage medium part 2 may specifically be a heat storage medium 3 housing, and the inner cavity of the heat storage medium 3 housing is filled with the heat storage medium 3. The heat absorption medium pipeline may specifically include a riser pipe 9 and a downcomer pipe 10. Both the riser pipe 9 and the downcomer pipe 10 pass through the inner cavity of the heat storage medium 3 housing and are wrapped by the heat storage medium 3.

[0042] It is set that the surface of the heat storage medium 3 housing facing the optical path channel 5 is the top surface. In order to ensure that the heat storage medium 3 above and below in the heat storage medium 3 housing can be uniformly heated, a heat absorption groove 7 is opened on the top surface in this embodiment. The heat absorption groove 7 extends downward to be close to the bottom surface of the heat storage medium 3 housing, and the inner wall surface of the heat absorption groove 7 is the heat absorption area provided with the absorption coating 8.

[0043] Meanwhile, in order to ensure that the sunlight transmitted through the optical path channel 5 can be directly transmitted into the heat absorption groove 7, the top surface of the heat storage medium 3 housing is set to be attached to the second end of the optical path channel 5 (i.e., attached to the lower end surface of the heat absorber panel 6).

[0044] In order to ensure the heat preservation and heating functions of the riser pipe 9 and the downcomer pipe 10, the bottom surface of the heat storage medium 3 housing can be set to extend below the lowest point of the heat absorption medium pipeline in the heat absorption tower body 1, that is, to wrap as much as possible the parts of the riser pipe 9 and the downcomer pipe 10 in the heat absorption tower body 1.

[0045] In this embodiment, the inner cavity of the heat absorption groove 7 is a heat absorption cavity. The groove depth direction of the heat absorption groove 7 is set to be the vertical direction, and the bottom surface of the heat absorption groove 7 is set to be a hemispherical bottom surface with a concave shape, so that the sunlight entering the heat absorption cavity can be uniformly absorbed and converted into heat energy. The converted heat will heat the heat storage medium 3 and the riser pipe 9 and the downcomer pipe 10 placed therein.

[0046] In this embodiment, the form of the above-mentioned heat storage medium 3 can be set to a solid form or a phase change energy storage form.

[0047] Taking the heat absorption medium in the riser pipe 9 and the downcomer pipe 10 as molten salt as an example, the sunlight is reflected by the heliostat in the external mirror field to the secondary parabolic mirror at the top of the heat absorber panel 6 and then reflected, and enters the interior of the heat absorption tower through the top of the heat absorber panel 6 to heat the heat storage medium 3. The heat storage medium 3, the riser pipe 9, and the downcomer pipe 10 can be heated integrally and maintained at above 300°C for a long time, ensuring the preheating effect of the pipeline or facilitating the smooth desalting of the salt. The remaining salt in the pipeline during shutdown will not hang on the wall and condense, and can also reduce or even replace the electricity consumption for electric heating preheating during system startup.

[0048] The main operating conditions of this embodiment are described below:

[0049] 1. There may be light curtailment during the operation of tower solar thermal power generation. In this embodiment, the heat absorption system can utilize the light curtailment during the day to heat the heat storage medium 3. The heat accumulated by light curtailment is stored in the heat storage medium 3, and this part of the heat maintains the temperature of the riser pipe 9 and the downcomer pipe 10 after the heat absorption system stops operating (such as during the night and cloudy days, etc.), which is convenient for desalting the pipeline.

[0050] 2. When the tower solar thermal power generation system is under maintenance, overhaul or in a low DNI situation (solar light is not sufficient to support the operation of the heat absorption system), the light from the mirror field is focused to heat the heat storage medium 3 to preheat the pipeline. Once the repair work is completed or the DNI rises to an operable state, the heat absorption system can be directly started and operated.

[0051] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and their equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. An insulation device for pipelines inside a solar tower, characterized in that, it includes: A solar tower body, on which an optical path channel is provided, and the first end of the optical path channel is connected to the outside; A heat storage medium part, which is arranged inside the solar tower. The heat storage medium part is filled with a heat storage medium, and the heat storage medium wraps the heat absorption medium pipeline inside the solar tower body; an endothermic area is provided on the heat storage medium part, and the endothermic area corresponds to the optical path channel; A secondary reflector, which is arranged in an external mirror field, and the light reflection direction of the secondary reflector faces the optical path channel, and is used for reflecting the discarded light of the external mirror field; Under the working state, the discarded light is reflected by the secondary reflector, and is reflected to the endothermic area through the optical path channel. The heat storage medium in the heat storage medium part absorbs and stores the heat energy of sunlight to maintain the temperature of the heat absorption medium pipeline; The top of the solar tower body is an annular heat absorber panel; the inner wall surface of the heat absorber panel forms the optical path channel; The secondary reflector is arranged above the heat absorber panel.

2. The insulation device for pipelines inside a solar tower according to claim 1, characterized in that, A tertiary reflector is provided on the inner wall surface of the heat absorber panel.

3. The insulation device for pipelines inside a solar tower according to claim 1, characterized in that, The secondary reflector is a secondary parabolic reflector, which is used for focusing the reflected discarded light in the optical path channel and then diffusing it to the endothermic area.

4. The insulation device for pipelines inside a solar tower according to claim 1, characterized in that, An endothermic coating is provided on the endothermic area.

5. The insulation device for pipelines inside a solar tower according to claim 1, characterized in that, The heat storage medium part is a heat storage medium shell, and the inner cavity of the heat storage medium shell is filled with the heat storage medium; The surface of the heat storage medium shell facing the optical path channel is the top surface, and an endothermic groove is opened on the top surface, and the inner wall surface of the endothermic groove is the endothermic area.

6. The insulation device for pipelines inside a solar tower according to claim 5, characterized in that, The top surface is attached to the second end of the optical path channel; The bottom surface of the heat storage medium shell extends below the lowest point of the heat absorption medium pipeline inside the solar tower body.

7. The insulation device for pipelines inside a solar tower according to claim 5, characterized in that, The depth direction of the endothermic groove is the vertical direction, and the bottom surface of the endothermic groove is a hemispherical bottom surface which is concave downward.

8. The insulation device for pipelines inside a solar tower according to claim 1, characterized in that, The form of the heat storage medium is a solid form or a phase change energy storage form.

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