LED spectrum photobioreactor system for microalgae cultivation

Abstract

The invention belongs to a photobioreactor in the field of bioengineering, and particularly relates to a photobioreactor system with novel LED spectrum design for microalgae cultivation. Which comprises a reaction tank (used for containing algae liquid and assembling a special spectrum light source transparent pipeline and related equipment), a special spectrum light source transparent pipeline combination acting on a reaction system, and an automatic transparent pipeline cleaning device, and is characterized in that a multi-spectrum light source combination lamp strip is placed in the special spectrum light source transparent pipeline; the multi-spectrum light source combined lamp strip comprises a main light source and an auxiliary light source, and the continuous spectrum design parameters of the main light source are as follows: the peak wavelength is 465-495 nm, the main wavelength is 510-535 nm, and the continuous spectrum range is 380-780 nm; according to the continuous spectrum design of the auxiliary light source, the light absorption peak of the microalgae is used as the peak wavelength, multiple continuous spectrums are formed, and the spectrum range is 380 nm to 780 nm. According to the invention, the problem of spectrum design defects of indoor artificial light culture of microalgae and the problem of wall adhesion of microalgae in a transparent pipeline of a special spectrum light source are solved, the photosynthesis efficiency of microalgae is improved, and the yield of microalgae is increased.

Description

Technical Field

[0001] The present invention belongs to the field of bioengineering photobioreactor, and in particular refers to a photobioreactor system with a novel LED spectrum design for microalgae cultivation. Background Art

[0002] Due to the huge economic and medical value of microalgae, it is a general trend to cultivate microalgae indoors with artificial light. However, there are two major problems with the current photobioreactor system that uses artificial light to cultivate microalgae: (1) There are defects in the design of the artificial light spectrum that promotes microalgae photosynthesis, which leads to slow accumulation of biomass of indoor cultivated microalgae and a yield that is more than 50% lower than that of outdoor sunlight cultivation. Microalgae belong to phytoplankton. The main basis for the design of plant growth lighting LED spectrum is the light absorption peak of the plant, which is used as the peak wavelength of the plant lighting growth spectrum to form a continuous spectrum of 380nm-780nm, and is combined with artificial light solar spectrum to promote plant growth. For example, Xuyu Optoelectronics (Shenzhen) Co., Ltd., a well-known domestic plant lighting professional lighting manufacturer, designed a universal full spectrum for plant lighting with a peak wavelength of 450nm (chlorophyll light absorption peak) and a solar spectrum with a peak wavelength of 650nm. For details, see the scientific and technological achievements appraisal organized by Xuyu Optoelectronics (Shenzhen) Co., Ltd. organized by the China Light Industry Federation in 2022 (registration number 2022053). The artificial spectrum design of microalgae is basically to design a continuous spectrum with the microalgae light absorption peak as the peak wavelength, and to match it with artificial light solar spectrum illumination. For example, Spirulina contains four photosynthetic pigments: carotenoids, phycocyanin, chlorophyll, and phycoerythrin. Therefore, Spirulina exhibits multiple light absorption peaks in the 450nm, 620nm, and 680nm bands. Based on this, the artificial light spectrum is designed, and the solar spectrum is matched and adjusted to the optimal illumination of the light source to cultivate Spirulina indoors. However, the yield is always lower than that of outdoor cultivation. This is also the case for other microalgae such as golden algae, horn algae, and chlorella. Light is a kind of energy transmission. The low yield of indoor artificial light cultivation of microalgae indicates low photosynthesis efficiency, insufficient light energy, and defects in spectrum design under the same other conditions. In other words, artificial light cannot reach the photosynthetic efficiency of natural sunlight for the growth of microalgae. Based on this situation, we further monitored the changes in light waves in the natural sunlight spectrum from 6:30 in the morning to 18:30 in the afternoon, and conducted tests in Guangxi, Hebei and Liaoning provinces and regions. We found that the 450nm-500nm (cyan light) band in the natural sunlight spectrum changes the least during the day and is very stable. The peak wavelength of the cyan light band is around 477nm at 12:30 noon.We believe that, from the perspective of the 4 billion years of biological evolution on Earth, the stable light waves of 450nm-500nm in sunlight should play a very important role in biological evolution and growth, especially the peak wavelength of this band. Therefore, after repeated experiments, the preferred solution is to avoid the less effective 450nm-465nm band of blue light and the 495nm-500nm band of green light, and select 475nm as the peak wavelength to design a 380nm-780nm continuous spectrum. In combination with the original spectrum of spirulina growth lighting, the final yield of spirulina cultivated under artificial light indoors is 40% higher than that of outdoor sunlight cultivation. It can be seen that the original spirulina growth lighting spectrum lacks further strengthening of the key blue light band, resulting in low photosynthesis efficiency of microalgae and slow biomass accumulation. The same is true for the experimental results of golden algae, chlorella, and flat algae. (2) At present, most of the photobioreactor systems for indoor cultivation of microalgae use a transparent tube with a special spectrum light source placed in the algae solution in the reaction pool for photosynthesis, such as patents ZL202223113631.3 and ZL202222129863.1. However, due to the phototropism of microalgae, a layer of microalgae will soon stick to the wall of the transparent tube of the light source placed in the algae solution, resulting in a significant decrease in illumination, making it difficult to carry out effective photosynthesis. Therefore, the transparent tube of the light source should be equipped with an automatic cleaning device. Summary of the invention

[0003] The purpose of the present invention is to provide a photobioreactor system with a new LED spectrum design. The new LED spectrum design is designed into two types of spectra with 465nm-495nm light waves and microalgae light absorption peak as peak wavelengths to promote microalgae photosynthesis, while solving the problem of microalgae sticking to the wall of transparent pipes of underwater special spectrum light sources and reducing light loss.

[0004] The overall technical concept of the present invention is:

[0005] An LED spectrum photobioreactor system for microalgae cultivation comprises a reaction pool (for containing algae liquid and assembling a special spectrum light source transparent pipeline and related equipment), a special spectrum light source transparent pipeline combination acting on the reaction system, and a transparent pipeline automatic cleaning device. A plurality of spectrum light source combination light strips are placed in the special spectrum light source transparent pipeline. The plurality of spectrum light source combination light strips include a main light source and an auxiliary light source. The continuous spectrum design parameters of the main light source are: peak wavelength 465nm-495nm, main wavelength 510nm-535nm, and continuous spectrum range 380nm-780nm. The continuous spectrum design of the auxiliary light source takes the microalgae light absorption peak as the peak wavelength to form a plurality of continuous spectra with a spectrum range of 380nm-780nm.

[0006] The specific technical concept of the present invention also includes:

[0007] In the embodiment of indoor artificial light cultivation of Spirulina, the special spectrum light source combination is:

[0008] (A) Main light source: peak wavelength 475.6nm, main wavelength 520.5nm, continuous spectrum range 380nm-780nm, color temperature 5345K.

[0009] (B1) Auxiliary light source: peak wavelength 599nm, main wavelength 583nm, color temperature 3031K, continuous spectrum range 380nm-780nm.

[0010] (B2) Auxiliary light source: peak wavelength 450nm, main wavelength 581.5nm, color temperature 4631K, continuous spectrum range 380nm-780nm.

[0011] In order to solve the problem of microalgae sticking to the outer wall of the transparent pipeline of the special spectrum light source, the preferred technical solution is to set up an upper slide rail and a lower slide rail on the same plane above and below the transparent pipeline of the special spectrum light source, and an automatic transparent pipeline cleaning device is provided between the upper slide rail and the lower slide rail, which can reciprocate along the transparent pipeline of the special spectrum light source by relying on the track running motor, and a rotating brush sleeve is provided on the periphery of the transparent pipeline of the special spectrum light source, and the rotating brush sleeve is connected to the upper slide rail and the lower slide rail by an independent bracket, an upper pulley, and a lower pulley, and the upper slide rail and the lower slide rail are connected to the wall of the reaction tank.

[0012] In order to realize the effective operation of the automatic transparent pipe cleaning device, the preferred technical solution is that the automatic transparent pipe cleaning device is provided with a rechargeable battery-driven track running motor and a brush rotating motor, and a gear transmission structure is provided between the brush rotating motor and the rotating brush sleeve, which is composed of a brush rotating motor transmission gear A and a rotating brush sleeve transmission gear B located in the same plane. The gear transmission structure drives the brush to rotate to remove the microalgae sticking to the wall, and the rotating brush sleeve can be disassembled.

[0013] The reaction pool is also equipped with a water truck to keep the algae liquid flowing, as well as water supply and drainage pipelines, algae harvesting equipment, etc.

[0014] The technical progress achieved by the present invention:

[0015] 1. Experiments have proved that the 450nm-500nm cyan band in sunlight is the most stable band in sunlight, with a peak wavelength of about 477nm. The cyan band plays a leading role in improving the photosynthesis efficiency of microalgae. It is not enough to rely solely on the microalgae light absorption peak as a continuous spectrum with a peak wavelength to promote the growth of microalgae. Both are required to work together, and the number of main light sources accounts for more than 50%.

[0016] 2. Experiments have shown that according to the different light intensity requirements of different microalgae, selecting different light waves in the range of 465nm-495nm as the continuous spectrum formed by the peak wavelength with the strongest energy can improve the photosynthesis efficiency of various microalgae and increase the yield of microalgae.

[0017] 3. Experiments have shown that a considerable portion of microalgae contain more than two photosynthetic pigments, each of which has a different light absorption peak, and therefore requires continuous spectrum combination lighting with multiple different peak wavelengths.

[0018] 4. The pipeline outer wall cleaning device, which uses a rotating brush sleeve and a motor gear transmission structure located in the same plane as the main design features, solves the problem of microalgae sticking to the wall of the transparent pipeline of the special spectrum light source. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a schematic diagram of the structure of a reaction pool and a transparent pipeline combination of a special spectral light source and an automatic pipeline cleaning device.

[0020] Figure 2 It is a schematic structural diagram of the automatic transparent pipe cleaning device of the present invention.

[0021] The accompanying drawings are marked as follows:

[0022] 1. Reaction pool 2. Special spectrum light source transparent pipeline 3. Cooling fan

[0023] 4. Multiple spectrum light source combination light strip 5. Upper slide rail 6. Lower slide rail

[0024] 7. Transparent pipe automatic cleaning device 7A. Rotating brush sleeve 8. Rechargeable battery

[0025] 9. Track running motor 10. Brush rotation motor 11. Transmission gear A

[0026] 12. Transmission gear B 13. Brush 14. Upper pulley 15. Lower pulley

[0027] 16. Independent bracket

[0028] The accompanying drawings show embodiments of the present invention. The embodiments of the present invention are further described below in conjunction with the accompanying drawings, but should not be construed as limiting the present invention. The protection scope of the present invention shall be based on the contents recorded in the claims. Any replacement of equivalent technical means made according to the specification shall not depart from the protection scope of the present invention.

[0029] The overall technical structure of this embodiment is shown in the figure, which is an LED spectrum photobioreactor system for microalgae cultivation, including a reaction tank 1 (for containing algae liquid and assembling a special spectrum light source transparent pipeline 2 and related equipment), a special spectrum light source transparent pipeline 2 combination acting on the reaction system, and a transparent pipeline automatic cleaning device 7. A multi-spectrum light source combination light strip 4 is placed in the special spectrum light source transparent pipeline 2. The multi-spectrum light source combination light strip 4 includes two types of main light sources and auxiliary light sources. The continuous spectrum design parameters of the main light source are: peak wavelength 465nm-495nm, main wavelength 510nm-535nm, and continuous spectrum range 380nm-780nm; the continuous spectrum design of the auxiliary light source uses the microalgae light absorption peak as the peak wavelength to form a variety of continuous spectra with a spectral range of 380nm-780nm.

[0030] In the embodiment of indoor artificial light cultivation of Spirulina, the special spectrum light source combination is:

[0031] (A) Main light source: peak wavelength 475.6nm, main wavelength 520.5nm, continuous spectrum range 420nm-780nm, color temperature 5345K.

[0032] (B1) Auxiliary light source: peak wavelength 599nm, main wavelength 583nm, color temperature 3031K, continuous spectrum range 380nm-780nm.

[0033] (B2) Auxiliary light source: peak wavelength 450nm, main wavelength 581.5nm, color temperature 4631K, continuous spectrum range 380nm-780nm.

[0034] An upper slide rail 5 and a lower slide rail 6 are set on the same plane above and below the special spectrum light source transparent pipeline 2, and an automatic transparent pipeline cleaning device 7 is arranged between the upper slide rail 5 and the lower slide rail 6, which can reciprocate along the special spectrum light source transparent pipeline 2 by relying on a track running motor 9, and a rotating brush sleeve 7A is arranged on the periphery of the special spectrum light source transparent pipeline 2, and the rotating brush sleeve 7A is connected to the upper slide rail 5 and the lower slide rail 6 by an independent bracket 16, an upper pulley 14, and a lower pulley 15, and the upper slide rail 5 and the lower slide rail 6 are connected to the pool wall of the reaction pool 1.

[0035] The transparent pipe automatic cleaning device 7 is provided with a rechargeable battery 8 to drive the track running motor 9 and the brush rotating motor 10 to operate. There is a gear transmission structure between the brush rotating motor 10 and the rotating brush sleeve 7A, which is composed of a transmission gear A11 of the brush rotating motor 10 and a transmission gear B12 of the rotating brush sleeve 7A located in the same plane. The gear transmission structure drives the brush 13 to rotate to remove the microalgae sticking to the wall. The rotating brush sleeve 7A can be disassembled.

[0036] The reaction pool 1 is also equipped with a water truck to keep the algae liquid flowing, as well as water supply and drainage pipelines, algae harvesting equipment, etc.

[0037] This embodiment implements control in the following way:

[0038] First, according to the tolerance of different microalgae to light intensity, the peak wavelength is selected in the 465nm-495nm cyan band to design a continuous spectrum (A spectrum). For example, if spirulina has a high tolerance to light intensity, the strongest light wave 475nm-478nm in the 465nm-495nm cyan band can be selected as the peak wavelength to design a continuous spectrum (A spectrum). Secondly, with the multiple light absorption peaks of microalgae as the peak wavelength, a variety of continuous spectra (B spectra) are designed respectively, and together with the A spectrum, a variety of spectrum light source combination light strips are made. In the process of making special spectrum light sources, it is mainly to reasonably select blue light chips with different technical parameters, and encapsulate them with fluorescent powder to form the required special spectrum light source. These tasks need to be customized by professional LED light source factories. Third, during the microalgae cultivation process, the transparent pipeline automatic cleaning device 7 needs to be started every day to clean the outer pipe wall, and the rotating brush sleeve 7A can be disassembled to clean the microalgae accumulated inside. Fourth, the microalgae cultivation in the reaction tank 1 is also equipped with a water truck to stir the water flow and add nutrient solution. When the microalgae are cultivated to a certain concentration, the microalgae collection equipment and water supply and drainage pipelines are started to collect algae and carry out water supply and drainage work.

Claims

1. An LED spectrum photobioreactor system for microalgae cultivation, comprising a reaction pool (1) (used to hold algae liquid and to assemble a special spectrum light source transparent pipeline (2) and related equipment), a special spectrum light source transparent pipeline (2) combination acting on the reaction system, and a transparent pipeline automatic cleaning device (7), characterized in that A multi-spectrum light source combination light strip (4) is placed in the special spectrum light source transparent pipeline (2). The multi-spectrum light source combination light strip (4) includes two types of main light sources and auxiliary light sources. The continuous spectrum design parameters of the main light source are: peak wavelength 465nm-495nm, main wavelength 510nm-535nm, and continuous spectrum range 380nm-780nm; the continuous spectrum design of the auxiliary light source uses the microalgae light absorption peak as the peak wavelength to form a plurality of continuous spectra with a spectrum range of 380nm-780nm.

2. The LED spectrum photobioreactor system for microalgae cultivation according to claim 1, characterized in that In the embodiment of indoor artificial light cultivation of Spirulina, the special spectrum light source combination is: (A) Main light source: peak wavelength 475.6nm, main wavelength 520.5nm, continuous spectrum range 380nm-780nm, color temperature 5345K.

3. (B1) Auxiliary light source: peak wavelength 599nm, main wavelength 583nm, color temperature 3031K, continuous spectrum range 380nm-780nm.

4. (B2) Auxiliary light source: peak wavelength 450nm, main wavelength 581.5nm, color temperature 4631K, continuous spectrum range 380nm-780nm.

5. The LED spectrum photobioreactor system for microalgae cultivation according to claim 1, characterized in that An upper slide rail (5) and a lower slide rail (6) are arranged on the same plane above and below the special spectrum light source transparent pipeline (2); an automatic transparent pipeline cleaning device (7) is arranged between the upper slide rail (5) and the lower slide rail (6), and can reciprocate along the special spectrum light source transparent pipeline (2) by means of a track running motor (9); a rotating brush sleeve (7A) is arranged on the periphery of the special spectrum light source transparent pipeline (2); the rotating brush sleeve (7A) is connected to the upper slide rail (5) and the lower slide rail (6) by an independent bracket (16), an upper pulley (14), and a lower pulley (15); and the upper slide rail (5) and the lower slide rail (6) are connected to the wall of the reaction pool 1.

6. The LED spectrum photobioreactor system for microalgae cultivation according to claim 3, characterized in that The transparent pipeline automatic cleaning device (7) is provided with a rechargeable battery (8) to drive a track running motor (9) and a brush rotating motor (10) to operate. A gear transmission structure is provided between the brush rotating motor (10) and the rotating brush sleeve (7A), which is composed of a transmission gear A (11) of the brush rotating motor (10) and a transmission gear B (12) of the rotating brush sleeve 7A located in the same plane. The gear transmission structure drives the brush (13) to rotate and remove microalgae adhering to the wall. The rotating brush sleeve (7A) is disassembled.

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