CN101358578B - Chimney generation and desalination device by solar - Google Patents

Abstract

The invention relates to a device for using solar energy to generate electricity in a chimney and to desalinize seawater, and relates to the technical field of generating electricity and desalinating seawater by using solar energy. The invention includes a solar chimney, a transparent heat collection shed, a solar distillation pool, and a turbine generator set. The transparent heat collection shed is covered on the supporting group, and a turbine generator set is arranged in the solar chimney at the junction of the solar chimney and the transparent heat collection shed; A solar distillation pool and a rock heat storage layer are arranged below the heat collection shed, a transparent cover is arranged obliquely at the upper end of the solar distillation pool, and the lower end of the solar distillation pool is respectively connected with seawater input pipes, salt water output pipes, and fresh water output pipes. The invention improves the comprehensive utilization efficiency of solar energy, improves the comprehensive utilization efficiency of land resources, and simultaneously reduces the cost of each product, such as electricity, heat storage, fresh water and the like.

Description

A device that utilizes solar energy for chimney power generation and seawater desalination

technical field

The invention relates to the technical field of generating electricity and seawater desalination by using solar energy. the

Background technique

The solar chimney power generation system mainly consists of four parts: solar chimney, heat collection shed, heat storage layer and turbine generator set. The heat collection shed composed of transparent surface cover and support is centered on the solar chimney, distributed in a circular shape, and has a certain distance from the surface heat storage layer. The light-transmitting and heat-insulating heat-collecting shed is equivalent to a huge glass greenhouse. The surface thermal storage layer inside it absorbs the solar short-wave radiation and the temperature rises, and heats the air in the shed. The air absorbs heat, the temperature rises, and the density decreases. The external environment forms a density difference, thereby forming a pressure difference. The chimney, which acts as a negative pressure pipe, increases the pressure difference inside and outside the system, forming a powerful updraft to drive a single air turbine generator placed in the center of the bottom of the chimney or multiple small air turbine generators arranged in groups to generate electricity. Since the heat storage layer absorbs a large amount of solar radiation energy during the day, it will continue to release heat at night, which can realize continuous power generation. the

Due to the inherent power generation characteristics of the solar chimney power generation system, that is, day and night fluctuations, it lacks the characteristics of adapting to load changes and stabilizing the system unique to thermal power and hydropower. From a thermodynamic point of view, the solar chimney power generation technology is still solar thermal power generation, and the solar heat collection shed is only a low-temperature heat source, which determines that it is difficult to improve the efficiency of the solar chimney power generation system purely for power production. It is also difficult to obtain a conversion efficiency greater than 1% under very ideal conditions. At the same time, the solar chimney power generation system occupies a large area, and the land utilization rate is low. the

There are two ways to use solar energy to desalinate seawater. One is the seawater phase change process driven by the thermal energy generated by solar energy, that is, the distillation process; the other is the electrodialysis process driven by solar power generation. Solar distillation technology refers to the use of heat collected from solar energy to heat seawater, so that seawater evaporates and undergoes a phase change process to form water vapor, and then condenses the water vapor to collect fresh water. the

The water production of traditional solar distillation devices is relatively low. There are three reasons: First, the latent heat of condensation of steam is not reused, but is lost to the atmosphere through the cover plate. The second is the natural convection heat transfer mode in the traditional solar distillation device, which greatly limits the improvement of the thermal performance of the distillation device. The third is that the heat capacity of the seawater to be evaporated in the traditional solar distillation device is too large, which limits the increase of the operating temperature, thereby weakening the driving force of evaporation. Therefore, in order to increase the water yield of the solar distillation system, the above three defects must be overcome. At the same time, the solar distillation device occupies a large area, and the land utilization rate is low. the

Contents of the invention

The technical problem to be solved by the present invention is: aiming at the shortcomings and deficiencies of the solar chimney power generation system purely used for electric power production and the solar distillation device purely for fresh water production, improve the comprehensive utilization efficiency of solar energy, improve the comprehensive utilization efficiency of land resources, and change the direction at the same time Reduced cost per product, such as electricity, heat storage, fresh water, etc. the

In order to achieve the above object, the present invention adopts the following technical solutions:

The invention includes a solar chimney, a transparent heat collection shed, a solar distillation pool, and a turbine generator set. The transparent heat collection shed is covered on the supporting group, and a turbine generator set is arranged in the solar chimney at the junction of the solar chimney and the transparent heat collection shed; A solar distillation pool and a rock heat storage layer are arranged below the heat collection shed, a transparent cover is arranged obliquely at the upper end of the solar distillation pool, and the lower end of the solar distillation pool is respectively connected with seawater input pipes, salt water output pipes, and fresh water output pipes. the

Preferably, the solar distillation pool of the present invention is arranged in a ring shape, and multiple sets of support groups are arranged at equal intervals in the radial direction of the solar distillation pool, and transparent cover plates are arranged obliquely on the upper ends of the adjacent two sets of support groups, and the upper ends of the adjacent two sets of support groups are arranged obliquely. A transparent cover plate is arranged obliquely on the upper end of the support group and the rock heat storage layer. the

Preferably, each supporting group of the present invention includes a support pier and a support, the support is arranged on one side of the upper end of the support pier, an oblique transparent heat collection shed is fixedly arranged on the support, and an oblique transparent cover plate is fixedly arranged on the support pier. the

Preferably, the upper end of each pier of the present invention is provided with a horizontal ring-shaped fresh water collection tank, and each pier is respectively provided with a vertical fresh water drainage pipe, and the two ends of the vertical fresh water drainage pipe are respectively connected with a horizontal ring-shaped fresh water collection tank and a fresh water output pipe. the

Preferably, the device for utilizing solar energy for chimney power generation and seawater desalination of the present invention is characterized in that: a rock heat storage layer is arranged below the above-mentioned turbine generating set and near the center of the heat collection shed, and the periphery of the rock heat storage layer is arranged Solar distillation pool. the

Preferably, the chimney power generation and seawater desalination device utilizing solar energy according to the present invention is characterized in that: the lower end of the above-mentioned rock heat storage layer is provided with an insulating layer. the

Preferably, the device for generating chimney power and seawater desalination using solar energy according to the present invention is characterized in that: an insulating layer is set between the solar distillation pool and the seawater input pipe, brine output pipe, and fresh water output pipe. the

When the present invention is working: the transparent heat-collecting shed composed of a transparent surface cover and a bracket is centered on the solar chimney, distributed in a circular shape, and has a certain distance from the transparent cover plate of the solar distillation pool, and a turbine generator set is installed at the bottom of the chimney . Part of the solar radiation that passes through the transparent heat collection shed and the transparent cover of the distillation tank is reflected from the water surface, and the rest is absorbed by the water body through the black lining in the water tank, which increases the temperature of the sea water and evaporates part of the water. Since the solar energy absorbed by the cover plate is very little, and it directly dissipates heat to the airflow between the heat collecting shed and the transparent cover plate, the temperature of the transparent cover plate is lower than the water temperature in the pan, so convection is generated in the inner space of the distillation tank, and the water surface and The heat exchange between the transparent covers will be carried out through radiation, convection and evaporation, so that the moist air is in contact with the condensing surface of the transparent covers. Then, the water vapor evaporated from the water in the tank will condense on the lower surface of the transparent cover to release latent heat of vaporization. As long as the transparent cover has an appropriate inclination angle, the condensed water will flow down the transparent cover under the action of gravity, collect in the sump, and then flow out of the distiller through the drain hole of the device to become finished fresh water. The heated seawater heat storage layer and the latent heat of vaporization released by the condensation of water vapor heat the air between the heat collection shed and the transparent cover of the solar distillation pool. The solar radiation passing through the transparent heat collection shed is absorbed by the rock heat storage layer at the same time to further heat the air in the shed. The air absorbs heat, the temperature rises, the density decreases, and a density difference is formed with the external environment, thus forming a pressure difference. The chimney, which acts as a negative pressure pipe, increases the pressure difference inside and outside the system, forming a strong updraft to drive a single air turbine generator placed in the center of the bottom of the chimney or multiple small air turbine generators arranged in a ring to generate electricity. At the same time, The cold air around the transparent heat-collecting shed enters the shed, forming a continuous air circulation. On the other hand, the increase of the air velocity in the shed is in turn beneficial to the heat dissipation of the transparent cover plate, thereby relatively increasing the temperature difference between the cover plate and the seawater evaporation surface, and increasing the fresh water production. Studies have pointed out that when the wind speed increases from 0 to 2.15m/s, the water production of the device increases by about 11.5%. When increasing from 2.15m/s to 8.81m/s, the water production of the device only increases by 1.5%. This shows that the light wind is conducive to the increase of water production, while the strong wind makes the increase of water production not obvious. This is why the seawater heat storage layer is arranged on the outside and the rock heat storage layer is arranged on the inside. The ratio of the outer seawater heat storage layer to the inner rock heat storage layer should be determined according to the best income. Since the seawater and rock heat storage layer absorb a large amount of solar radiation energy during the day, they will continue to release heat at night, which can realize continuous power generation and fresh water production. the

Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

1. With the structure of the present invention, the latent heat of condensation released by seawater during evaporation and condensation is used to heat the airflow in the integrated system, and the flow of airflow will promote the evaporation of seawater and increase the production of fresh water. Significantly improve the efficiency of solar energy utilization. the

2. The present invention combines solar power generation and solar seawater desalination devices together, and its construction cost is lower than the sum of the construction costs of single-purpose solar chimney power generation and solar seawater desalination distillation devices with the same capacity, and the occupied land resources are also much lower than the same capacity. The sum of the land resources of the capacity single-objective solar chimney power generation and the solar desalination distillation device. It can be seen that this integrated system can not only improve the comprehensive conversion efficiency of solar energy, but also improve the comprehensive utilization efficiency of land resources. In addition, it can also reduce the cost of each product (electricity, heat storage, fresh water) from another angle. the

3. In the present invention, a rock heat storage layer is set at the center of the solar seawater desalination device that also plays a heat storage role, so that continuous power generation and desalination of seawater can be completed even when there is no sun at night, which enhances the scope of use of the present invention . the

4. Western my country is very rich in solar energy resources, with an average annual sunshine time of 2800-3300 hours, and a large number of wasteland, Gobi Desert and deserts available for site selection, so it is especially suitable for the construction of large-scale solar chimney power stations. Furthermore, since many areas in the west have rich brackish water resources, if the joint development of solar chimney power generation and seawater desalination can be implemented, it will inevitably produce greater resource utilization benefits, and improve the quality and capacity of power supply and water supply. The prospect is very bright broad. the

5. The construction cost of the solar chimney power station of the present invention is not high, the manufacturing technology is relatively mature, and the operating cost and maintenance cost after the power station is completed are low; it does not occupy cultivated land, does not destroy resources, and only uses desert land; large-area heat-collecting greenhouse The comprehensive utilization of solar energy desalination and raw salt production will not only cause no pollution, but also improve the environment in western China, which is short of water, electricity, and ecologically fragile. These are very suitable for my country's national conditions and the geographical and economic conditions of the west. At the same time, they are also an excellent way to partially replace fossil energy. If they can be applied, they will have very huge economic, social and ecological benefits, and have broad application prospects. . the

Description of drawings

Fig. 1 is a kind of structural representation of the present invention. the

Fig. 2 is a schematic structural view of the support group of the present invention. the

Detailed ways

In the figure: 1. Solar chimney; 2. Turbine generator set; 3. Transparent heat collection shed; 4. Support; 5. Transparent cover; 6. Support group; 61. Buttress; 7. Cold air; 9, fresh water drainage pipe; 10, solar distillation pool; 11, rock thermal storage layer; 12, thermal insulation layer; 13, sea water input pipe; 14, salt water output pipe; 15, fresh water output pipe; 16, sea water (or brackish water). the

The technical scheme of the present invention is described in detail below in conjunction with accompanying drawing:

As shown in Figure 1, the present invention comprises a solar chimney 1, a transparent heat collecting shed 3, a solar distillation pool 10, a turbine generator set 2, and the transparent heat collecting shed 3 is covered on the supporting group 6, and is located between the solar chimney 1 and the transparent heat collecting shed 3 The solar chimney 1 at the connection is provided with a turbine generator set 2; a solar distillation pool 10 and a rock heat storage layer 11 are arranged under the transparent heat collection shed 3, and the solar distillation pool 10 is arranged on the outer periphery of the rock heat storage layer 11; The upper end of the pool 10 is obliquely provided with a transparent cover plate 5, and the lower end of the solar distillation pool 10 is respectively connected with a seawater input pipe 13, a salt water output pipe 14, and a fresh water output pipe 15. Seawater 16 or brackish water is in the solar distillation pool. the

Preferably, the solar distillation tank 10 of the present invention is arranged in a ring shape, and multiple sets of support groups 6 are arranged at equal intervals in the radial direction of the solar distillation tank 10, and transparent cover plates 5 are arranged obliquely on the upper ends of the adjacent two groups of support groups 6, close to The support group 6 of the rock heat storage layer 11 and the upper end of the rock heat storage layer 11 are obliquely provided with a transparent cover plate 5 . the

Preferably, each group of supporting groups 6 of the present invention includes a support pier 61 and a support 4, the support 4 is arranged on one side of the upper end of the support pier 61, and the support 4 is fixedly provided with an oblique transparent heat collection shed 3, and on the support pier 61 The oblique transparent cover plate 5 is fixedly arranged. the

Preferably, the upper end of each pier 61 of the present invention is provided with a horizontal annular fresh water collection tank 8, and a vertical fresh water drainage pipe 9 is respectively arranged in each pier 61, and the two ends of the vertical fresh water drainage pipe 9 are connected with the horizontal annular fresh water collection tank respectively. 8. The fresh water output pipe 15 is connected. the

Preferably, the lower end of the rock heat storage layer 11 of the present invention is provided with an insulating layer 12 . the

Preferably, an insulating layer 12 is provided between the solar distillation pool 10 of the present invention and the seawater input pipe 13 , the brine output pipe 14 , and the fresh water output pipe 15 . the

The following is a set of data to compare the utilization rate of solar energy between the independent solar chimney power generation system and the integrated solar chimney power generation seawater desalination system:

In order to be uniform in calculation, it is assumed that the diameter of the heat collection shed is D _coll = 250m, the diameter of the rock heat storage layer is D _xu = 40m, the diameter of the chimney is D _ch = 10.3m, the height is H _ch = 200m, and the height of the entrance of the heat collection shed is H _{coll, in} = 2m, seawater layer thickness is H _w = 0.05m.

At the same time, stable meteorological conditions are taken in the analysis: the average solar radiation intensity is H=800W/m ² , and the average ambient temperature is t _a =27.2°C. In the following formula, η _w is the power of the turbine and the generator set, and the unit is W; T _{ch, in} is the air temperature at the chimney inlet, and the unit is K; ρ _{ch, in} is the air density at the chimney inlet, and the unit is K; q _ew is The heat transfer rate from the water surface to the condensation surface, the unit is W/m ² ; h _fg is the latent heat of vaporization of water, the unit is J/kg.

1. Independent solar chimney power generation system

The power generated by the solar chimney power generation system is:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; w</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; \&pi;</span>}{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; g</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2.8955</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}\mathrm{<span\; class="notranslate">\; W</span>}$

The solar energy utilization efficiency is:

${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; sc</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}}{\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; coll</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.74</span>}<span\; class="notranslate">\; \%</span>$

2. Integrated solar chimney power generation-heat storage layer-seawater desalination system

The power generated by the solar chimney power generation system is:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; e</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 3</span>}}{\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; w</span>}}{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}\mathrm{<span\; class="notranslate">\; \&pi;</span>}{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; g</span>}{\mathrm{<span\; class="notranslate">\; h</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}}\frac{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; ch</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; in</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1.2912</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{\mathrm{<span\; class="notranslate">\; 5</span>}}\mathrm{<span\; class="notranslate">\; W</span>}$

Water production: ${m^{\&Center\; Dot;}}_e=\frac{q_e}{h_{\mathrm{fg}}}=1.842\&times;{10}^{-4}\mathrm{kg}/(m^2\&Center\; Dot;\mathrm{the\; s})$

The solar energy utilization efficiency of the integrated system is: ${\mathrm{\&eta;}}_{\mathrm{system}}=\frac{\frac{1}{4}\mathrm{\&pi;}({\mathrm{D.}}_{\mathrm{coll}}^2-{\mathrm{D.}}_{\mathrm{xu}}^2)q_{\mathrm{ew}}+P_e}{\frac{1}{4}\mathrm{\&pi;}({\mathrm{D.}}_{\mathrm{coll}}^2-{\mathrm{D.}}_{\mathrm{ch}}^2)\&Center\; Dot;h}=55.35\%.$

It can be seen from the above data that the utilization rate of solar energy with the functions of solar chimney power generation and seawater desalination is higher. the

Claims (2)

1. A device for utilizing solar energy to generate electricity through a chimney and seawater desalination, characterized in that it comprises a solar chimney (1), a transparent heat collection shed (3), a solar distillation pool (10), a turbine generator set (2), a transparent collector The heat shed (3) is covered on the supporting group (6), and a turbine generator unit (2) is arranged in the solar chimney (1) at the junction of the solar chimney (1) and the transparent heat collecting shed (3); (3) The solar distillation pool (10) and the rock thermal storage layer (11) are arranged below the solar distillation pool (10), and the solar distillation pool (10) is arranged on the outer periphery of the rock thermal storage layer (11); the upper end of the solar distillation pool (10) is arranged obliquely The transparent cover plate (5), the lower end of the solar distillation tank (10) is respectively connected to the seawater input pipe (13), the salt water output pipe (14), and the fresh water output pipe (15); The above-mentioned solar distillation pool (10) is arranged in a ring shape, and multiple groups of support groups (6) are arranged at equal intervals in the radial direction of the solar distillation pool (10), and transparent cover plates (5) are arranged obliquely on the upper ends of two adjacent groups of support groups (6). ), the support group (6) near the rock heat storage layer (11) and the upper end of the rock heat storage layer (11) are obliquely provided with a transparent cover plate (5); Each above-mentioned supporting group (6) includes a pier (61), a support (4), the support (4) is arranged on one side of the upper end of the pier (61), and an oblique transparent heat collection shed ( 3), the oblique transparent cover plate (5) is fixedly arranged on the buttress (61); The upper end of each of the above-mentioned piers (61) is provided with a horizontal annular freshwater collection tank (8), and a vertical freshwater drainage pipe (9) is respectively arranged in each of the piers (61), and the two ends of the vertical freshwater drainage pipe (9) are respectively horizontal annular freshwater The collection tank (8) and the fresh water output pipe (15) are connected; A thermal insulation layer (12) is arranged at the lower end of the above-mentioned rock heat storage layer (11). 2. the device utilizing solar energy to carry out chimney power generation and seawater desalination according to claim 1, is characterized in that: above-mentioned solar distillation tank (10) and seawater input pipe (13), brine output pipe (14), fresh water output pipe ( 15) insulation layer (12) is set between.

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