An efficient microalgae cultivation device

Abstract

The present invention discloses an efficient microalgae cultivation device, belonging to the fields of solar energy utilization and biotechnology. The microalgae cultivation device includes: a culture container filled with microalgae liquid; a light condensing element, the lower part of the light condensing element is immersed in the microalgae liquid, and the light condensing element is used to adjust the sunlight incident on the light condensing element into parallel light or divergent light and then downwardly introduce it into the microalgae liquid to increase the light intensity in the microalgae liquid; and an orientation adjusting member, the orientation adjusting member is used to control the direction of the sunlight incident on the light condensing element. In this application, the sunlight incident on the light condensing element is adjusted into parallel light or divergent light by the light condensing element and then downwardly introduced into the microalgae liquid, increasing the light intensity in the microalgae liquid, ensuring the light source required for microalgae growth, and being not affected by the microalgae density or the depth of the algae liquid at the same time. This application only uses solar energy without the need for electric energy, reducing the cost of microalgae cultivation.

Description

Technical Field

[0001] The invention belongs to the field of light energy utilization and biotechnology, and relates to a high-efficiency microalgae cultivation device. Background Art

[0002] Microalgae refers to the general term for microorganisms that contain chlorophyll a and can perform photosynthesis. Microalgae biomass is rich in protein, oil, polysaccharides, etc., especially containing bioactive substances such as unsaturated fatty acids, polysaccharides, pigments, etc., and has the function of enhancing the body's immunity. Therefore, microalgae biomass can be used as a raw material source for high-value-added products such as microalgae food, health products, medicines, animal feed, bioenergy, etc., and has a good economic development prospect.

[0003] The cultivation of microalgae biomass was carried out in closed and open photosynthetic bioreactors.

[0004] A closed photosynthetic bioreactor is a reactor in which the microalgae do not come into contact with the outside environment during the cultivation process, and the culture container needs to be sealed. The closed photosynthetic reactor is relatively expensive, has a long construction period, high operating requirements, is not easy to clean and scale up, and has high maintenance costs in the later stages of cultivation. In the middle and late stages of cultivation, as the density of the microalgae increases, the light transmittance of the closed reactor deteriorates, affecting the photosynthesis efficiency. The closed environment is prone to the accumulation of O 2 , which is toxic to the growth of microalgae. Therefore, closed photosynthetic bioreactors have not yet been used on a large scale.

[0005] An open photosynthetic bioreactor refers to a reactor in which the microalgae are in contact with the external environment during the cultivation process, and the culture container does not need to be sealed. The main types are: shallow water pools and runway pools. Open photosynthetic bioreactors are widely used in large-scale commercial microalgae cultivation. Shallow water pools are shallow, small in volume, low in breeding density per unit area, and high in breeding costs. Runway pools are generally deeper than shallow water pools, which makes it difficult for the microalgae in the lower layer to absorb light, affecting their growth. Artificial light sources are required, such as LED light sources to supplement the light, which consumes a lot of electricity.

[0006] Therefore, it is necessary to propose an energy-saving, light-transmitting and efficient microalgae cultivation device. Summary of the invention

[0007] In order to at least solve the problem in the prior art that the light transmittance of the photosynthetic bioreactor for cultivating microalgae deteriorates due to the increase of microalgae density or the increase of pool water depth, thus affecting the growth of microalgae, the present invention provides the following technical solution: an efficient microalgae cultivation device, the microalgae cultivation device comprising:

[0008] a culture container filled with microalgae liquid;

[0009] A condensing element, the lower part of the condensing element being immersed in the microalgae liquid, the condensing element being used to adjust the sunlight incident on the condensing element into parallel light or divergent light and then guiding it downward into the microalgae liquid to increase the light intensity in the microalgae liquid; and

[0010] An orientation adjusting member, the orientation adjusting member being used to control the direction of the sunlight incident on the condensing element.

[0011] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the condensing element includes:

[0012] A condensing part, the condensing part being used to adjust the sunlight incident on the condensing part into the converging light;

[0013] A light adjusting part, the light adjusting part being located below the condensing part and being used to adjust the converging light from the condensing part into parallel light or divergent light; and

[0014] A conduction part, the conduction part being of a hollow structure, located below the light adjusting part, the conduction part being connected to the light adjusting part, at least part of the conduction part being immersed in the microalgae liquid, the conduction part being used to guide the parallel light or divergent light from the light adjusting part downward into the microalgae liquid.

[0015] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, both the condensing part and the light adjusting part are Fresnel lenses, and the specification size of the condensing part is larger than the specification size of the light adjusting part; and / or

[0016] The conduction part is a light guide tube made of glass or light-transmitting plastic; and / or

[0017] The parallel light is parallel to the axis line of the light guide tube;

[0018] The divergent light is arranged at an angle to the parallel light.

[0019] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the orientation adjusting member includes: a solar tracker;

[0020] The solar tracker is installed on the condensing element and is used to keep the sunlight always irradiating on the condensing element at the designed incident angle.

[0021] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the orientation adjusting member includes: a reflective element;

[0022] The reflective element is used to reflect the sunlight onto the condensing element.

[0023] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the reflective element includes: a first reflector and a second reflector;

[0024] The first reflector is disposed above the culture container through a mounting bracket;

[0025] The second reflector is located on the periphery of the culture container and is used to reflect the sunlight irradiated on the second reflector onto the first reflector;

[0026] The first reflector is used to reflect the sunlight from the second reflector downward onto the condensing element.

[0027] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, a solar tracker is installed on the second reflector to keep the second reflector facing the sun at all times.

[0028] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, a solar tracker is installed on the first reflector to keep the sunlight from the first reflector vertically irradiating the top of the condensing element.

[0029] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the sunlight incident on the condensing element includes: direct light and indirect light;

[0030] The direct light is the direct radiation light from the sun;

[0031] The indirect light is the sunlight reflected onto the condensing element.

[0032] Optionally, in the above-mentioned high-efficiency microalgae cultivation device, the culture container is an open container, and the side wall plate of the culture container is made of a light-shielding material or is coated with a light-shielding coating; or

[0033] The culture container is a closed container, one end of the condensing element passes through the top plate of the culture container and is immersed in the microalgae liquid, and the other end of the condensing element is located outside the culture container.

[0034] The beneficial effects brought by the technical solution provided by the embodiment of the present invention are:

[0035] In this application, the sunlight incident on the condensing element is adjusted into parallel light or divergent light and then downwardly introduced into the microalgae liquid, increasing the light intensity in the microalgae liquid, ensuring the light source required for microalgae growth, and being not affected by the microalgae density or the depth of the algae liquid. This application only uses solar energy and does not require electric energy, reducing the cost of microalgae cultivation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic structural diagram of a high-efficiency microalgae cultivation device provided by an embodiment of the present invention;

[0037] Figure 2Schematic diagram of the working principle of an efficient microalgae cultivation device provided by an embodiment of the present invention;

[0038] Figure 3 Another specific structural schematic diagram of an efficient microalgae cultivation device provided by an embodiment of the present invention;

[0039] In the figure: 1, culture container; 2, light condensing element; 21, large Fresnel lens; 22, small Fresnel lens; 23, light duct; 24, connecting pipe; 3, light reflecting element; 31, first reflector; 32, second reflector; 4, mounting rack; 5, solar tracker. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] In the description of the present invention, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations to the present invention. The terms "connected", "coupled", and "disposed" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected, or detachably connected; they can be directly connected, or indirectly connected through intermediate components; they can be wired connections, radio connections, or wireless communication signal connections. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0042] Please refer to Figures 1-3, the present invention provides the following technical solution: An efficient microalgae cultivation device, which includes: a culture container 1, a light concentrating element 2, and an orientation adjusting member. The culture container 1 (also known as the reaction tank body) is filled with microalgae liquid. The number of the light concentrating elements 2 can be set according to actual needs. The light concentrating element 2 is fixed in the (open) culture container 1 through a bracket (not shown in the figure), or a through hole is opened on the top plate of the (sealed) culture container 1. After the light concentrating element 2 is inserted into the through hole, it will not shake left and right. The type of the culture container 1, whether it is an open or sealed container, is not limited in this embodiment. The lower part of the light concentrating element 2 is immersed in the microalgae liquid. The part of the light concentrating element 2 located in the microalgae liquid is made of glass or light-transmitting plastic, with good light transmittance. When in use, the light concentrating element 2 adjusts the sunlight incident on the light concentrating element 2 into parallel light (referring to the light parallel to the axis line of the light concentrating element 2) or divergent light (in this article, it refers to approximately parallel light, which deviates slightly from the axis line of the light concentrating element 2, and can be understood that the divergent light and the parallel light are set at an angle). The purpose of the light concentrating element 2 to adjust the light (referring to sunlight) is that the light (referring to sunlight) propagates in the air before reaching the light concentrating element 2, resulting in energy loss (light attenuation). Multiple weakened light rays are adjusted by the light concentrating element 2 for the first time to become convergent light, increasing the energy density, and then adjusted by the light concentrating element 2 for the second time to become parallel light or approximately parallel light. Finally, the parallel light or approximately parallel light propagates downward in the inner cavity of the light concentrating element 2, and the light is refracted outward through the lower tube wall of the light concentrating element 2 with good light transmittance (that is, the light concentrating element 2 guides the processed light downward) into the microalgae liquid, increasing the light intensity in the microalgae liquid, ensuring the light source required for the growth of microalgae, and being not affected by the microalgae density or the depth of the pool water. The orientation adjusting member is used to control the direction of sunlight incident on the light concentrating element 2, so that the sunlight can be kept irradiating on the light concentrating element 2 at the designed incident angle at any time. Preferably, in this application, the sunlight incident on the light concentrating element 2 includes: direct light and indirect light. The direct light is the direct radiation light from the sun, such as the sunlight at noon. The indirect light is the sunlight reflected onto the light concentrating element 2. The depth of the culture container 1 in this application is 1 - 10 m. Compared with a shallow pool, it has a large pool volume, a high cultivation density per unit area, and a low cultivation cost. At the same time, this application only uses solar energy and does not require electric energy (that is, energy-saving), reducing the cost of microalgae cultivation.

[0043] Refer to Figure 2As shown in the figure, the light condensing element 2 includes a light condensing part, a light regulating part, and a conducting part. Among them, the light condensing part is used to adjust the sunlight incident on the light condensing part into converging light, that is to say, the function of the light condensing part is to condense light, so that the light energy intensity per unit area can be increased. The light regulating part is located below the light condensing part, and the two are arranged at intervals. The light regulating part is used to adjust the converging light from the light condensing part into parallel light or diverging light, that is to say, the light regulating part changes the propagation direction of the light converged by the light condensing part and scatters the light to the conducting part. The conducting part is a hollow structure, located below the light regulating part, and at the same time the conducting part is connected to the light regulating part, and at least part of the conducting part is immersed in the microalgae liquid. The conducting part is used to guide the parallel light or diverging light from the light regulating part downward through the bottom or the inner side wall of the conducting part into the microalgae liquid, supplement the light energy required by the microalgae, ensure the needs for the growth of the microalgae, and thus increase the microalgae cultivation concentration.

[0044] Preferably, in this embodiment, both the light condensing part and the light adjusting part are Fresnel lenses arranged coaxially. The Fresnel lens has high light transmittance, small volume, light weight, easy processing, and low cost. Through the Fresnel lens, the light irradiated on the Fresnel lens can be concentrated into the conduction part, effectively collecting and utilizing solar energy. The Fresnel lens can be made of materials such as glass or polymethyl methacrylate (PMMA). To achieve uniform light condensation, compared with traditional Fresnel lenses, the light condensing part preferably uses a multi-focus composite Fresnel lens or a toroidal focusing Fresnel lens. The specification size of the light condensing part is larger than that of the light adjusting part, which can also be understood as the projection area of the light condensing part is larger than that of the light adjusting part. Therefore, we call the light condensing part the large Fresnel lens 21 and the light adjusting part the small Fresnel lens 22. The large Fresnel lens 21 is used for light condensation, and the small Fresnel lens 22 is used to adjust the light into parallel light and / or approximate parallel light. The Fresnel lenses are connected by a connecting pipe 24. It should be noted that in actual on-site installation, the total number of Fresnel lenses used in the process of adjusting light is 2 to 5 pieces. These Fresnel lenses are arranged vertically in the order of decreasing specification size, and the shape can be square or circular. Due to reflection loss, absorption loss, process loss, and structural loss, etc., the more Fresnel lenses the light passes through, the more energy loss and the lower the optical efficiency. This embodiment takes two Fresnel lenses (light condensation + scattering) as an example for introduction. In other embodiments, it can also be a combination of multiple Fresnel lenses (such as light condensation + light condensation + scattering), which will not be introduced one by one here. The conduction part is a light guide pipe 23 made of glass or light-transmitting plastic. The light guide pipe 23 is a hollow pipe, and its size should be suitable for the size of the small Fresnel lens 22 to achieve seamless connection and installation. Its pipe diameter is 10 to 300 mm, and its length is 1 to 10 m. The length of the light guide pipe 23 is flexibly set according to the depth of the culture container 1 (or microalgae liquid). Preferably, the bottom of the light guide pipe 23 is about 200 mm close to the bottom of the culture container 1. It should be noted that before use, according to the actual on-site need to irradiate parallel light or divergent light into the microalgae liquid, flexibly select the Fresnel lens assembly (referring to the large Fresnel lens 11 and the small Fresnel lens 12), and fix the Fresnel lens assembly on the top of the light guide pipe 23. The number of light condensing elements 1 can be flexibly set according to the actual on-site need. For the culture container 1 with a large pool volume, multiple light guide pipes 23 (i.e., light condensing elements 2) with Fresnel lens assemblies are uniformly arranged in the culture container 1 (i.e., the reaction tank body) with an outer wall spacing of 100 to 500 mm. This application uses the light guide pipe 23 to introduce light into the microalgae liquid in the culture container 1, realizing the uniform light reception of microalgae cells and improving the production efficiency per unit floor area.

[0045] To meet the requirements of the optimal light intensity for the cultivation of different types of microalgae, the large Fresnel lens 21 and the small Fresnel lens 22 in the device of the present invention are designed differently. For example: the large Fresnel lens 21 has a specification size of 600X600mm, and the small Fresnel lens 22 has a specification size of φ150mm, achieving 20-fold light concentration.

[0046] As an embodiment of the specific structure of the above-mentioned orientation member, in this embodiment, the orientation member includes: a solar tracker 5. The solar tracker 5 is installed on the light concentrating element 2, such as the solar tracker 5 is installed on the light conduit 23 (as Figure 3 shown), and the solar tracker is used to keep the sunlight irradiating on the light concentrating element 2 at the designed incident angle at all times.

[0047] As another embodiment of the specific structure of the above-mentioned orientation member, in this embodiment, the light adjusting member includes: a reflecting element 3. The reflecting element 3 is used to reflect the sunlight onto the light concentrating element 2. Specifically, the reflecting element 3 includes: a first reflecting mirror 31 and a second reflecting mirror 32. Among them, the first reflecting mirror 31 is arranged above the culture container 1 through a mounting bracket 4. The second reflecting mirror 32 is located outside the culture container 1, and the second reflecting mirror 32 is used to reflect the sunlight irradiated on the second reflecting mirror 32 onto the first reflecting mirror 31. The first reflecting mirror 31 is used to reflect the sunlight from the second reflecting mirror 32 downward onto the light concentrating element 2, where "downward" here includes vertically downward and also includes inclined downward at an angle with the vertical direction. The included angle between the divergent light emitted by the small Fresnel lens 22 and the center line of the light conduit 23 is determined after being designed according to the length of the pipeline conduit and the size of the small Fresnel lens 22. It should be noted that neither the first reflecting mirror 31 nor the second reflecting mirror 32 is a single reflecting mirror, but is composed of multiple groups of reflecting mirrors with different angles. Preferably, the sunlight reaches the light concentrating element 2 after 2 to 5 reflections. In Figure 2 the shown drawing, only two reflecting mirrors are schematically shown. The number of the first reflecting mirror 31 and the second reflecting mirror 32 is designed according to the specification size of the culture container 1. The second reflecting mirror 32 can adopt a circular layout, and each second reflecting mirror 32 is in a staggered state; or a linear array layout, and the second reflecting mirrors 32 are arranged on multiple parallel straight lines, and the second reflecting mirrors 32 on each row are located on the same straight line, and the second reflecting mirrors 32 between adjacent rows are staggered in the east-west direction. It should be noted that adding the words "first" and "second" in front of the reflecting mirror is only for distinction and has no other special meaning. In addition, the specific installation positions of all the reflecting mirrors and Fresnel lenses in this application are determined by technicians according to several experimental simulations and on-site measurement data.

[0048] Refer to Figure 2As shown in the figure, in order to keep the second reflector 32 facing the sun at all times, a solar tracker 5 is installed on the second reflector 32. The solar tracker 5 is a power device that allows the light rays of sunlight to be perpendicularly incident on the second reflector 32 at all times. A commercially available solar tracker 5 can be used, and this embodiment does not limit it. The first reflector 31 reflects the sunlight from the second reflector 32 obliquely downward onto the condensing element 2 (referring to the large Fresnel lens 21). In this way, the sunlight is successively shaped into convergent light and divergent light by the large Fresnel lens 21 and the small Fresnel lens 22, and then obliquely irradiates the side wall of the culture container 1. Preferably, the culture container 1 is an open container, and the side wall plate of the culture container 1 is made of a light-shielding material or is coated with a light-shielding coating. A concrete pool can be used, and a heat-insulating board can be provided on the outer wall to achieve a heat-insulating effect.

[0049] In other embodiments, the culture container 1 is a closed container, such as a tubular reactor. One end of the condensing element 2 (referring to the conduction part, that is, the light guide tube 23) passes through the through hole on the top plate of the culture container 1 and is immersed in the microalgae liquid, and the other end of the condensing element 2 (referring to the condensing part and the light-adjusting part) is located above the microalgae liquid. On the basis of installing a solar tracker 5 on the second reflector 32, a solar tracker 5 (not shown in the figure) is also installed on the first reflector 31, which is used to keep the sunlight from the first reflector 31 perpendicularly incident on the top of the condensing element 2 (referring to the large Fresnel lens 21). That is to say, through this solar tracker 5, the first reflector 31 reflects the sunlight from the second reflector 32 vertically downward onto the condensing element 2. In this way, the sunlight is successively shaped into convergent light and parallel light by the large Fresnel lens 21 and the small Fresnel lens 22, and then vertically downward irradiates into the culture container 1.

[0050] Figure 3 An optional solution (without the reflective element 3) is provided. This solution is suitable for microalgae cultivation under environmental conditions with sufficient sunlight. As shown in the figure: The condensing element 2 is an integral element composed of a condensing part (referring to the large Fresnel lens 21), a light-adjusting part (referring to the small Fresnel lens 22), and a conduction part. At the same time, a solar tracker 5 is installed on the upper part of the conduction part (referring to the light guide tube 23). When the sun moves, through the action of the solar tracker 5, the condensing part, the light-adjusting part, and the conduction part can be integrally moved to adjust the direction, and the incident angle of the sunlight irradiating on the large Fresnel lens 21 is adjusted to the required angle to ensure the focusing effect of the large Fresnel lens 21. One solar tracker 5 can act on the overall movement of one group or multiple groups of condensing elements 2. However, when the number of condensing elements 2 is very large, multiple solar trackers 5 need to be set.

[0051] Figure 2 and Figure 3 It is mainly considered to cope with the differences in light intensity at different geographical locations and the different optimal light intensities required for different microalgae species. Figure 2A reflective element 3 is provided in [the device] to reflect more sunlight to the light concentrating element 2, which can supplement the impact of insufficient sunlight on microalgae cultivation. Figure 3 In [the device], the reflective element 3 is removed, which can reduce the construction investment cost and is applicable to microalgae cultivation under environmental conditions with sufficient sunlight. In addition, Figure 2 in [the device], since the solar tracker 5 is provided on the second reflector 32, the sunlight can be made to perpendicularly irradiate the second reflector 32 at any time through the solar tracker 5. Figure 3 in [the device], since the solar tracker 5 is provided on the light guide pipe 23, the sunlight can be made to irradiate the large Fresnel lens 21 at the designed incident angle at any time through the solar tracker 5. Figure 2 and Figure 3 For these two cases, selection should be made according to the local sunlight intensity and the types of microalgae to be cultivated.

[0052] As is known by common technical knowledge, the present invention can be implemented by other embodiments without departing from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all aspects and not exclusive. All changes within the scope of the present invention or equivalent to the present invention are encompassed by the present invention.

Claims

1. An efficient microalgae cultivation device, characterized in that: The microalgae cultivation device comprises: a culture container filled with microalgae liquid; A light-concentrating element, the lower part of which is immersed in the microalgae liquid, and the light-concentrating element is used to adjust the sunlight incident on the light-concentrating element into parallel light or divergent light and then guide it downward into the microalgae liquid to increase the light intensity in the microalgae liquid; and a direction-adjusting member, the direction-adjusting member is used to control the direction in which the sunlight is incident on the focusing element, The light focusing element comprises: A light-concentrating portion, the light-concentrating portion is used to adjust the sunlight incident on the light-concentrating portion into concentrated light; a light adjusting unit, the light adjusting unit being located below the light focusing unit and being used for adjusting the converged light from the light focusing unit into parallel light or divergent light; and The conducting part is a hollow structure, located below the dimming part, connected to the dimming part, at least part of the conducting part is immersed in the microalgae liquid, and the conducting part is used to guide the parallel light or divergent light from the dimming part downward into the microalgae liquid. The light focusing part and the light adjusting part are both Fresnel lenses arranged coaxially. The light focusing unit is composed of one or more Fresnel lenses. The size of the Fresnel lens of the focusing part is larger than the size of the Fresnel lens of the dimming part. The Fresnel lenses are arranged in descending order of size. The direction-adjusting member comprises: a reflective element; The reflective element is used to reflect sunlight onto the focusing element. The reflective element comprises: a first reflector and a second reflector; The first reflector is arranged above the culture container through a mounting frame; The second reflector is located at the periphery of the culture container and is used to reflect the sunlight irradiated on the second reflector to the first reflector; The first reflector is used to reflect the sunlight from the second reflector downward onto the focusing element, The first reflector and the second reflector are composed of multiple groups of reflectors with different angles. The second reflectors are arranged on a plurality of parallel straight lines, the second reflectors in each row are located on the same straight line, and the second reflectors between adjacent rows are arranged alternately in an east-west direction.

2. The high-efficiency microalgae cultivation device according to claim 1, characterized in that: The transmission part is a light guide made of glass or light-transmitting plastic material; and / or The parallel light is parallel to the axis of the light guide; The divergent light is arranged at an angle to the parallel light.

3. The high-efficiency microalgae cultivation device according to claim 1, characterized in that: The direction-adjusting component includes: a solar tracker; The solar tracker is installed on the focusing element to ensure that the sunlight is irradiated on the focusing element at a designed incident angle at all times.

4. The high-efficiency microalgae cultivation device according to claim 3, characterized in that: A sun tracker is installed on the second reflector to keep the second reflector facing the sun at all times.

5. The high-efficiency microalgae cultivation device according to claim 3, characterized in that: A solar tracker is installed on the first reflector to keep the sunlight from the first reflector vertically irradiating the top of the focusing element.

6. The high-efficiency microalgae cultivation device according to claim 1, characterized in that: The sunlight incident on the focusing element includes: direct light and indirect light; The direct light is direct radiation from the sun; The indirect light is sunlight reflected onto the focusing element.

7. The high-efficiency microalgae cultivation device according to claim 1, characterized in that: The culture container is an open container, and the side wall of the culture container is made of a light-shielding material or is coated with a light-shielding coating; or The culture container is a closed container, one end of the light focusing element passes through the top plate of the culture container and is immersed in the microalgae liquid, and the other end of the light focusing element is located outside the culture container.

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