Tower type secondary reflection type photo-thermal firing technology and control method

Abstract

The invention provides a tower type secondary reflection type photo-thermal firing technology. A firing object is a working medium which can be prepared only at high temperature, such as cement, ceramic and the like. The system comprises a primary reflecting mirror field, a secondary reflecting tower, a control device and the like, solar rays are converged to a reaction kiln placed on the ground through secondary reflection, a lighting opening of the reaction kiln faces upwards, and a reaction working medium in the reaction kiln is fired. And the control system is used for adjusting the heating temperature of the working medium raw material and ensuring that the working medium is fired within a proper temperature range. Revolutionary clean energy is provided for working media needing high-temperature preparation, solar energy is directly used for firing, the preparation temperature reaches 1000 DEG C or above, greenhouse gas is completely not discharged, safety is high, maintenance cost is low, and compared with a traditional firing process, consumption of a large amount of electric power and fossil fuel is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar energy application, and in particular, relates to a photothermal firing technology and a control method thereof, aiming to improve the energy efficiency and environmental friendliness of high-temperature working fluid preparation. Background Art

[0002] At present, the working fluids that need to be prepared at high temperature generally require a temperature of 800-1600℃, such as cement / ceramics, etc., which generally use firing furnaces as the main firing equipment, and the energy fuels of the firing furnaces are mainly coal, gas, natural gas, oil, electricity, biomass gas, etc. The above fuels mainly come from traditional non-renewable energy and have the defect of polluting the environment. How to reduce dependence on traditional energy is a problem that needs to be considered.

[0003] Solar energy is an inexhaustible renewable energy source. Currently, there are many types of concentrated heat absorption technologies, such as tower, trough, Fresnel, etc. Among them, tower solar technology has the advantages of high efficiency, high concentration ratio, strong heat storage capacity, stable operation, etc., and the secondary reflection tower solar technology is compared with the traditional tower, and the reactor is placed on the ground, which is easy to maintain and manufacture. Therefore, the use of solar energy as the energy source of the firing furnace can promote the realization of the energy conservation and carbon reduction goals of the building materials industry, and has important economic and social benefits.

[0004] At present, there are patent documents related to the use of solar energy as an energy source for firing ceramics. For example, the patent with the authorization announcement number CN118423995B discloses a ceramic solar thermal kiln, which is equidistantly fixed at a preset position on the ground between two solar concentrators. By adjusting the solar concentrators, it is ensured that the light spot focused by the solar concentrator falls on the outer surface of the porcelain. Although the above scheme completes the firing of ceramics through photothermal, its light-receiving surface is small and it is impossible to produce large pieces or large quantities of working fluids. In addition, the above scheme requires multiple adjustments of the concentrator during operation, which affects production efficiency. When applied to a tower solar thermal power station, the kiln needs to be placed at an altitude of 200m, which requires improving the current process and increasing the cost of construction and maintenance.

[0005] For example, the secondary reflection of the traditional solar furnace can also produce a high-temperature and high-concentration ratio environment, but its light opening is small, and the light opening of the reaction medium is level with the ground, so it can only adapt to small workpieces, indirect heating firing and horizontal direct firing conditions.

[0006] Therefore, how to use solar energy to directly burn qualified high-temperature working fluids, with a wide range of applications, diverse heating methods, and guaranteed production efficiency, is a technical problem that needs to be solved urgently. Summary of the invention

[0007] The purpose of the present invention is to provide a photothermal firing technology, which uses solar energy to directly or indirectly heat the working fluid raw materials that need to be fired at high temperature in the reaction kiln. To achieve the above purpose, the present invention provides a tower-based secondary reflection photothermal firing technology and control method.

[0008] The present invention provides a tower-type secondary reflection photothermal firing technology which consists of a primary reflection mirror field and a secondary reflection tower.

[0009] The primary reflector field includes a plurality of rotatable heliostats, which are distributed around the secondary reflector tower so that the sunlight is reflected to the secondary reflector tower through the heliostats.

[0010] The heliostat may be in a two-dimensional rotation mode or a multi-dimensional rotation mode.

[0011] The heliostat comprises a plurality of small reflectors, the area of ​​which ranges from 0.2 m2 to 3 m2, and the shape can be selected to be square or polygonal.

[0012] The secondary reflection tower is composed of a plurality of groups of rotatable secondary reflection mirrors and a secondary reflection mirror supporting structure.

[0013] The secondary reflector comprises a plurality of small reflectors, the area of ​​which ranges from 0.2 m2 to 3 m2, and the shape can be selected to be square or polygonal.

[0014] The secondary reflector can be selected as a two-dimensional rotation mode or a multi-dimensional rotation mode.

[0015] The secondary reflector support structure may be a steel structure, a concrete structure, a cable structure, or a mixed structure of various forms.

[0016] The control method provided by the present invention comprises the following steps:

[0017] Step 1: Install the reaction kiln at a designated location on the ground, with the center of the daylight opening located at the center of the focal plane of the photothermal firing focusing system;

[0018] Step 2: The photothermal firing focusing system calculates the energy flux density curve based on the temperature curve of the reaction kiln at different firing stages, and then calculates the theoretical control angle based on the energy flux density curve.

[0019] Step 3: During operation, the angle of the primary reflector field is controlled to ensure that the light spot falls on the designated position of the reaction kiln;

[0020] Step 4: By changing the angle of the secondary reflector and the position of the focus, the production efficiency of firing multiple groups of working fluids at the same time or firing in stages can be ensured.

[0021] Beneficial effects of the present invention:

[0022] (1) The photothermal firing technology of the present invention requires that the reaction kiln only needs to be installed on the ground, and the height only needs to be adapted to the irradiation range of the light spot. The process, manufacturing and subsequent maintenance are comparable to the current mature technology.

[0023] (2) In the photothermal firing technology of the present invention, both the secondary reflector and the primary reflector are small reflectors, and both have motion control functions, which greatly expands the controllability of the light spot. The energy flow distribution and direction of the light spot can be adjusted according to the temperature requirements of the reaction kiln at different stages, thereby improving the yield of the working medium firing, improving production efficiency, and adapting to reaction kilns of different sizes and reaction kilns installed at different angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of tower-type secondary reflective photothermal firing technology.

[0025] Figure 2 This is a diagram of the optical path changes after the control method is applied during the preparation of a working fluid.

[0026] Among them: 1-primary reflector field, 11-heliostat, 12-primary reflector rotation mechanism, 13-small primary reflector sub-mirror, 2-secondary reflector tower, 21-secondary reflector, 22-secondary reflector support structure, 23-small secondary reflector sub-mirror, 24-primary reflector rotation mechanism, 3-reaction kiln, 31-reaction raw material 1, 32-reaction raw material 2, 33-kiln transport vehicle, 211-secondary reflector after angle adjustment, 111-secondary reflected light before angle adjustment, 112-secondary reflected light after angle adjustment. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, a tower-based secondary reflection photothermal firing technology consists of a primary reflection mirror field 1 and a secondary reflection tower 2.

[0029] The primary reflector field 1 includes a plurality of rotatable heliostats 11, which are distributed around the secondary reflector tower 2, so that the sunlight is reflected to the secondary reflector tower through the heliostats.

[0030] The rotating mechanism 12 of the heliostat 11 may be in a two-dimensional rotating mode or a multi-dimensional rotating mode.

[0031] The heliostat comprises a plurality of small primary reflective sub-mirrors 13, the area of ​​which ranges from 0.2 m2 to 3 m2, and the shape of which can be selected to be square or polygonal.

[0032] The secondary reflection tower 2 is composed of a plurality of groups of rotatable secondary reflection mirrors 21 and a secondary reflection mirror support structure 22 .

[0033] The secondary reflector 21 comprises a plurality of small secondary reflector sub-mirrors 23, the area of ​​which ranges from 0.2 m2 to 3 m2, and the shape of which can be selected to be square or polygonal.

[0034] The secondary reflector 21 can be selected as a two-dimensional rotation mode 24 or a multi-dimensional rotation mode.

[0035] The secondary reflector support structure 22 may be a steel structure, a concrete structure, a cable structure, or a mixed structure of various forms.

[0036] The control method provided by the present invention is further illustrated by a group of embodiments below. The firing technology used is: Figure 1 The firing technique described.

[0037] This embodiment provides a method for controlling the preparation of a working fluid. Figure 2 As shown, the reaction kiln for preparing the working medium comprises a reaction kiln 3, reaction raw materials 31, reaction raw materials 32, and a kiln transport vehicle 33. The control process of the working medium preparation comprises the following steps:

[0038] Step 1: The kiln transport vehicle 33 transports the reaction kiln 3 to a designated position on the ground, and the center of the light-lighting opening is located at the center of the focal plane of the photothermal firing focusing system;

[0039] Step 2: The photothermal firing focusing system calculates the energy flux density curve according to the temperature curve 34 of the reaction kiln 3 at different firing stages, and then calculates the theoretical control angle according to the energy flux density curve. The primary reflector field 1 rotates the heliostat 11 to the specified angle and starts firing the reaction raw material 31.

[0040] Step 3: During the temperature rise phase of the reaction material 31 , the angle of the primary reflector field 1 is controlled to ensure that the light spot falls on the reaction material 31 to raise its temperature.

[0041] Step 4: When the temperature of the reaction raw material 31 reaches the insulation stage, the angle of the secondary reflector 21 is changed to 211. At this time, the light 111 after secondary reflection becomes the light 112, and the reaction raw material 32 begins to be heated.

[0042] At this time, the sunlight is used to keep the reaction material 31 warm and to heat the reaction material 32. This control method not only ensures the production efficiency of firing multiple groups of working fluids at the same time or firing in stages, but also achieves precise temperature control and maintains high efficiency in the utilization of sunlight.

[0043] The above provides some examples of currently preferred embodiments of the control method of the present invention, but these should not be interpreted as limiting the scope of use of the present invention.

Claims

1. A tower-type secondary reflective photothermal firing technology and control method, characterized in that: The purpose of directly or indirectly firing the working fluid by utilizing solar energy is achieved by irradiating the concentrated light or its divergent light reflected by the secondary reflector to the working fluid raw materials or the outside of the reaction kiln body at multiple angles. The heating temperature of the working fluid to be fired is adjusted by utilizing the rotatable small primary and secondary reflective mirrors to ensure that the working fluid raw materials are fired within the appropriate temperature range, thereby improving the yield of the working fluid firing.

2. The tower type secondary reflective photothermal firing technology according to claim 1 is characterized in that: The tower-type secondary reflection photothermal firing technology is composed of a primary reflection mirror field and a secondary reflection tower.

3. The tower type secondary reflective photothermal firing technology according to claim 2 is characterized in that: The primary reflector field includes a plurality of rotatable heliostats, which are distributed around the secondary reflector tower so that the sunlight is reflected to the secondary reflector tower by the heliostats. The heliostats can be selected as a two-dimensional rotation mode or a multi-dimensional rotation mode. The heliostats include a plurality of small reflectors, with an area ranging from 0.2㎡ to 3㎡, and a square or polygonal shape.

4. The tower type secondary reflective photothermal firing technology according to claim 2, characterized in that: The secondary reflector tower is composed of multiple groups of rotatable secondary reflectors and a secondary reflector support structure. The secondary reflectors include multiple small reflectors with an area ranging from 0.2㎡ to 3㎡, and the shape can be selected as a square or polygon. The secondary reflectors can be selected as a two-dimensional rotation mode or a multi-dimensional rotation mode. The secondary reflector support structure can be selected as a steel structure, a concrete structure, a cable structure, or a mixed structure of multiple forms.

5. The control method according to claim 1, comprising the following steps: Step 1: Install the reaction kiln at the designated position on the ground, with the center of the skylight located at the center of the focal plane of the focusing system; Step 2: The photothermal firing system calculates the energy flux density curve based on the temperature curves of different working fluids and raw materials in different firing stages in the reaction kiln, and the focusing system calculates the theoretical control angle based on the energy flux density curve; Step 3: During operation, the angle of the primary reflector field is controlled to ensure that the light spot falls on the designated position of the reaction kiln; Step 4: By changing the angle of the secondary reflector, the position of the focus is changed to ensure the production efficiency of firing multiple groups of working fluids at the same time or firing in stages.

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