A novel bionic multi-body floating water energy collection device and its design method

Abstract

The present invention provides a novel bionic multi-body floating water energy collection device and a design method thereof, comprising a plurality of bionic impellers arranged along an arc toward the river banks on both sides with the center of the river as the base point and a generator installed on the river bank; the bionic impeller is located in the water flow, and the bionic impeller comprises an airfoil blade, a hub and a support shaft, wherein a plurality of airfoil blades are fixed between two hubs, and a support shaft is connected between the two hubs, and the airfoil blades drive the rotation of the support shaft after being washed by the water flow, and torque is transmitted between the support shafts of each bionic impeller through a universal joint, and the support shaft closest to the shore is inserted into the generator to generate electricity, thereby realizing the recovery of water energy. The design method of the present invention is based on the Betz theory, and mainly designs the layout parameters of the multi-body floating device according to the water energy capture width, the maximum flow velocity, the bionic impeller parameters, etc., and can well adapt to the local water flow direction, has the advantages of simple design and novel structure, and can be widely used in rivers and offshore.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic machinery, and in particular relates to a novel bionic multi-body floating water energy collection device and a design method thereof. Background Art

[0002] Driven by the trend of "carbon neutrality", the demand for green and low-carbon industries is active. In order to reduce the proportion of fossil energy, considering the advantage of zero emission of hydropower, taking advantage of this advantage to develop hydropower is an important part of China's energy structure adjustment. my country has extremely rich small-scale hydropower resources, but the development rate is small. Therefore, there is huge potential for the development of small and medium-sized hydropower. How to better utilize this energy is a hot issue. To solve this problem, a new type of bionic multi-body floating water energy collection device and its design method are urgently needed, which can be used for the recovery of water flow potential energy. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a novel bionic multi-body floating water energy collection device and a design method thereof.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A novel bionic multi-body floating water energy collection device is characterized in that it includes: a plurality of bionic impellers arranged along an arc toward the river banks on both sides with the center of the river as the base point, and a generator installed on the river bank; the bionic impeller is located in the water flow, and the bionic impeller includes an airfoil blade, a hub and a support shaft, a plurality of airfoil blades are fixed between two hubs, and a support shaft is connected between the two hubs. The airfoil blades are washed by the water flow to drive the rotation of the support shaft, and the torque is transmitted between the support shafts of each bionic impeller through a universal joint, and the support shaft closest to the shore is inserted into the generator to generate electricity.

[0006] To optimize the above technical solutions, the specific measures taken also include:

[0007] Furthermore, the value of the staggered angle γ between the two hubs is: 10°≤γ≤60°.

[0008] Furthermore, the distance L2 between two adjacent bionic impellers has a value of: 1.5L1≤L2≤2.5L1, wherein L1 represents the length of the bionic impeller.

[0009] Furthermore, the value of the angle α between the arc-shaped connecting line of the plurality of bionic impellers and the river bank is: 10°<α<90°.

[0010] Furthermore, the angle β between the bionic impeller and the water flow velocity direction is i The value of: α≤β i ≤90°.

[0011] In addition, the present invention also proposes a design method for the novel bionic multi-body floating water energy collection device as described above, which is characterized by comprising the following steps:

[0012] S1: Set the length L1 of the bionic impeller and the distance L2 between two adjacent bionic impellers, 1.5L1≤L2≤2.5L1;

[0013] S2: Based on the average water capture width B and maximum flow velocity V max , select the angle α between the arc connecting line of several bionic impellers and the river bank, 10°<α<90°;

[0014] S3: Select the angle β between the water flow direction and the bionic impeller i , α≤β i ≤90°;

[0015] Taking the center point of the river as the base point, the distribution curve of the flow velocity at the center of the bionic impeller is established, where the bionic impellers on both sides of the base point are arranged symmetrically, and i is the serial number of the bionic impellers arranged along the base point to the two banks of the river. N is the number of bionic impellers, the bionic impeller number i at the center of the river is 0, the half of the length L1 of the bionic impeller is the flow velocity calculation point, the center distance between two adjacent bionic impellers is L1+L2, and the length of the bionic impeller number i relative to the center position of the bionic impeller at the base point is i(L1+L2);

[0016] According to the angle β between the water flow direction and the bionic impeller i And the length i(L1+L2) of the bionic impeller center relative to the base point, combined with the distribution curve of the bionic impeller center flow velocity, calculate the bionic impeller center flow velocity V i ;

[0017] S4: According to the bionic impeller center flow velocity V i And the angle β between the water flow direction and the bionic impeller i , determine the effective flow velocity V of the bionic impeller i '; According to the effective flow velocity V of the bionic impeller i ' and the swept area S of the bionic impeller, combined with the Bates theory, the maximum output power P of the entire water energy collection device is calculated max总 ;

[0018] S5: Calculate the angle β of each bionic impeller based on the CFD simulation value i The corresponding power P i , the simulated power P of the entire water energy collection device is obtained by accumulating m ' ax ; The simulated power P m ' ax and the maximum output power Pmax总 In comparison, if the proportion requirement is met, the bionic impeller is arranged according to the length L1 of the bionic impeller, the distance L2 between the bionic impellers, the number N of the bionic impellers and the angle α between the arc line and the river bank; otherwise, go to step S1 and reset the parameters of the bionic impeller until the requirement is met.

[0019] Furthermore, in step S3, the angle β between the water flow velocity direction and the bionic impeller is i =90°-iα3, where α3 is the decreasing compensation angle between the flow velocity and the impeller angle, and its value is related to the distance L2 between the bionic impellers, the average width B of the water energy capture, and the maximum flow velocity V max related.

[0020] Furthermore, in step S3, the bionic impeller center flow velocity

[0021] Furthermore, in step S4, the effective flow velocity V of the bionic impeller is i '=V i sin β i The maximum output power P of the entire water energy collection device max总 The maximum output power P of a single bionic impeller max Add up and you get, Here, ρ represents the density of water.

[0022] Furthermore, in step S5, the ratio requirement is P m ' ax =C1P max总 , the value of the proportional coefficient C1 is: 0.8≤C1≤1.2.

[0023] The beneficial effects of the present invention are as follows: the present invention provides a novel bionic multi-body floating water energy collection device and a design method thereof; the unique bionic impeller design enables it to adapt well to the local water flow direction; the water energy collection device is immersed and floated in the water flow to ensure the water flow capture area and avoid the impact of foreign objects on the water surface; the design method of the present invention is based on the Bates theory, and mainly designs the layout parameters of the multi-body floating device according to the water energy capture width, maximum flow velocity, bionic impeller parameters, etc., which can adapt well to the local water flow direction and can be effectively adjusted according to the power; unlike traditional large and bulky hydroelectric generators, the overall model of the water energy collection device of the present invention is low in cost and easy to use, and can be widely used in rivers and near the sea. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the layout of a new type of bionic multi-body floating water energy collection device.

[0025] Figure 2It is a simplified schematic diagram of the bionic impeller.

[0026] Figure 3 It is a schematic diagram of bionic impeller speed decomposition.

[0027] Figure 4 It is an axial schematic diagram of the bionic impeller.

[0028] Figure 5 It is a radial schematic diagram of the bionic impeller.

[0029] Figure 6 It is a schematic diagram of the inclined plane of the bionic impeller.

[0030] The reference numerals are as follows: 1. shore; 2. bionic impeller; 3. airfoil blades; 4. hub; 5. support shaft. DETAILED DESCRIPTION

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] Embodiment 1

[0033] In this embodiment, if Figure 1 , 4 -6, the present invention provides a novel bionic multi-body floating water energy collection device, comprising: a plurality of bionic impellers 2 arranged along an arc toward the river banks on both sides with the center of the river as the base point, and a generator installed on the shore 1; the bionic impeller 2 is located in the water flow, comprising an airfoil blade 3, a hub 4 and a support shaft 5, a plurality of airfoil blades 3 are fixed between two hubs 4, a support shaft 5 is connected between the two hubs 4, the airfoil blades 3 are flushed by the water flow, driving the rotation of the support shaft 5, torque is transmitted between the support shafts 5 of each bionic impeller 2 through a universal joint, and the support shaft 5 closest to the shore 1 is inserted into the generator to generate electricity.

[0034] In the specific example, the value of the staggered angle γ between the two hubs is: 10°≤γ≤60°; the value of the distance L2 between two adjacent bionic impellers is: 1.5L1≤L2≤2.5L1, where L1 represents the length of the bionic impeller; the value of the angle α between the arc-shaped connecting line of several bionic impellers and the river bank is: 10°<α<90°; the angle β between the bionic impeller and the flow velocity direction of the water is: i The value of: α≤β i ≤90°.

[0035] Embodiment 2

[0036] In this embodiment, further reference is made to Figure 2-3 The present invention provides a design method for a novel bionic multi-body floating water energy collection device according to an embodiment 1. In this method, the average water energy capture width B, the maximum flow velocity V max, with the help of public literature, the maximum thickness, chord length and trailing edge angle of the airfoil blade and the distance L1 between the two hubs are determined, and then the size of the airfoil blade is determined according to the angle γ between the upper and lower hubs. Then the bionic impellers are connected with universal joints, and the distance L2 between the two bionic impellers is designed according to the actual situation, and an arc arrangement is adopted; when the water flows through, it will wash the side of the impeller, driving the airfoil blades to rotate, and the airfoil blades drive the support shafts to rotate. The torque is transmitted between the support shafts through the universal joints, and the support shaft closest to the shore is inserted into the generator to generate electricity using kinetic energy, realizing the recovery of water energy.

[0037] The maximum thickness t, chord length b, trailing edge angle τ of the airfoil blade, the distance L1 between the two hubs, and the staggered angle γ between the upper and lower hubs are known, and the swept area S of the water flow passing vertically through the bionic impeller can be known. The layout design of the bionic impeller along the flow direction is carried out, and its main parameters include: the angle α between the arc-shaped connecting line of several bionic impellers and the river bank, the length L1 of the bionic impeller, the distance L2 between the two bionic impellers, and the number N of bionic impellers.

[0038] In the specific example, t = 6 mm, b = 30 mm, τ = 15°, L1 = 150 mm, γ = 60°, S = 4500 mm 2 .

[0039] The detailed design steps are as follows:

[0040] S1: Assume that the water can capture the average width B and the maximum flow velocity V max , according to actual needs, determine the distance L2 between the two bionic impellers. L2 can be at least 1.5L1, but it is generally recommended that L2 = (1.5 ~ 2.5) L1. If L2 is too small, it is easy to cause entanglement between the two impellers, resulting in damage to the entire device; if L2 is too large, it is not conducive to the power generation efficiency of the entire device.

[0041] In the specific example, B = 30m, V max =2.4m / s, L2=250mm.

[0042] S2: Based on the average water capture width B and maximum flow velocity V max , select the angle α between the arc line and the river bank. When the average width B is larger or the maximum flow velocity V max When the average width B is smaller or the maximum flow velocity V is larger, the value of α is smaller; when the average width B is smaller or the maximum flow velocity V is smaller, the value of α is smaller. max The smaller the angle, the larger the value of α. At the same time, if the α angle is too large, it is easy to cause the device to break, and if the α angle is too small, it is not conducive to power generation efficiency, so the recommended value range is 10°<α<90°.

[0043] In the specific example, α=60° is selected.

[0044] S3: Based on the average water capture width B and maximum flow velocity V max , with the maximum flow velocity V at the midpoint of the river max The location is taken as the base point, that is, the average width B / 2, and the flow velocity function is established.

[0045] Assume that the angle between the water flow velocity direction and the bionic impeller is β i , and β i The value range of is: [α,90°], assuming that the number of the bionic impeller in the center of the river is i = 0, and the angle β0 = 90°, then for the i-th bionic impeller, the angle β i =90°-iα3. When 90°-iα3<α, β i =90°-iα3≡α. α3 is the decreasing compensation angle between the flow velocity and the impeller angle. The value of α3 is related to the distance L2 between the two bionic impellers, the average width B of water energy capture, and the maximum flow velocity V max When B is smaller or L2 is larger or V max When B is large or L2 is small or V max When is smaller, α3 takes a small value.

[0046] Then the distribution curve of the flow velocity in the river that the device can intercept is calculated, and f(β i , i(L1+L2))=V i Equation. Simplifying the velocity distribution to be an arithmetic progression toward the shore, we get i is the serial number of the bionic impellers arranged along the base point to the two banks. The number of bionic impellers N is 2i+1, and the center point of the river i=0. The half of the length L1 of the bionic impeller is used as the flow velocity calculation point. The center distance between two adjacent bionic impellers is L1+L2. According to the relative position and the angle β i , calculate the center flow velocity V of each bionic impeller i .

[0047] In the specific example, α3 = 1°, β i =90°-i, α≤β i ≤90°, when i=31, 90°-iα3<α=60°, then when i≥31, β i ≡α=60°; When i=44, V 44 is less than 0, then the number of bionic impellers N is 87, and the flow velocity corresponding to each bionic impeller is obtained

[0048] S4: Determine the flow rate that can be effectively utilized by the bionic impeller, according to the angle β between the water flow velocity direction in step S3 and the bionic impeller i , the effective flow velocity V of each bionic impeller can be calculated i '=V isinβ i , simplify each individual bionic impeller, and calculate the power of the bionic impeller based on Bates theory.

[0049] like Figure 2 As shown, assuming that V i ' is the velocity of the water flow at an infinite distance in front of the airfoil blade (i.e., the effective velocity), V is the velocity of the water flow after it contacts the surface of the airfoil blade, V i ” is the water velocity at infinity behind the airfoil blade (i.e., wake velocity).

[0050] When the fluid flows through the airfoil blades, the energy of the water flow will be absorbed by the turbine, so the energy behind the turbine will be reduced. The energy on both sides is different. The unit time t = 1, so the expression of the force on the bionic impeller is:

[0051] Ft=F=m(V i '-V i ”)=ρSV(V i '-V i ”)

[0052] In the formula, m and ρ represent the mass and density of the water flow respectively;

[0053] Assuming an ideal situation, there is no need to consider the energy loss problem, so the expression for the energy absorbed by the bionic impeller is:

[0054] P=FV=ρSV 2 (V i '-V i ”)

[0055] When the fluid flows through the bionic impeller and the bionic impeller rotates, there must be an energy conversion equation:

[0056] P=FV=ρSV 2 (V i '-V i ”)

[0057] Because energy is conserved under ideal conditions, P and ΔT are equal. Simplifying, we get:

[0058]

[0059] The expressions of force F and output power P on the bionic impeller are as follows:

[0060]

[0061] Obviously V i ' is a given value, so it can be seen as output power P and wake velocity V i "Constitute a functional relationship.i "The derivative is:

[0062]

[0063] To find the maximum value of a quadratic function, let The solution can be obtained P max The relational expression is:

[0064]

[0065] From the above relationship, since the swept area S of the bionic impeller and the water density ρ are known, it can be considered that the output power P of the hydropower generator is only related to the water flow velocity V i ', so the water velocity V when the fluid flows through the bionic impeller is obtained i 'It is the core factor affecting the output power of the turbine.

[0066] Then the effective water flow velocity V of each bionic impeller is known i ', the swept area S of the impeller, and the output power P of the entire water energy collection device is calculated according to the Betz theory max总 .

[0067] In the specific example, the effective flow rate of each bionic impeller can be calculated According to the Bates theory, the maximum output power P of the entire water energy collection device is obtained by cumulative calculation. max总 =259.33W.

[0068] S5: According to the numerical calculation of CFD simulation, the angle β of each bionic impeller is i The corresponding power P i Simulate and calculate, and then add up to get P m ' ax , P m ' ax =∑P i . Verification requirements: If P m ' ax =C1P max总 , 0.8≤C1≤1.2, meets the requirements. If not, the step goes to S1 and the parameter value is reconsidered until the requirements are met.

[0069] In the specific example, P is accumulated m ' ax =284.9W, P m ' ax =1.1P max总 .

[0070] S6: Arrangement of the water energy collection device: According to the impeller length L1, the distance between the two impellers L2, the number of bionic impellers N, etc. obtained in the above steps, the bionic impellers are connected through universal joints, and a hydroelectric generator is set up on the river bank side according to the actual situation, thereby completing the arrangement of the new bionic multi-body floating water energy collection device.

[0071] In the specific example, the length of the bionic impeller L1=150 mm, the distance between the bionic impellers L2=250 mm, and the number of the bionic impellers N=87 are obtained.

[0072] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A design method for a novel bionic multi-body floating water energy collection device, the novel bionic multi-body floating water energy collection device comprising: A number of bionic impellers are arranged along an arc from the center of the river to the two banks, and a generator is installed on the river bank; The bionic impeller is located in the water flow, and comprises an airfoil blade, a hub and a support shaft. A plurality of airfoil blades are fixed between two hubs, and a support shaft is connected between the two hubs. The airfoil blades are washed by the water flow to drive the rotation of the support shaft. The support shafts of the bionic impellers are transmitted with torque through universal joints, and the support shaft closest to the shore is inserted into a generator to generate electricity. The design method comprises the following steps: S1: Set the length L1 of the bionic impeller and the distance L2 between two adjacent bionic impellers, 1.5L1≤L2≤2.5L1; S2: Based on the average water capture width B and maximum flow velocity V max , select the angle α between the arc connecting line of several bionic impellers and the river bank, 10°<α<90°; S3: Select the angle β between the water flow direction and the bionic impeller i , α≤β i ≤90°; Taking the center point of the river as the base point, the distribution curve of the flow velocity at the center of the bionic impeller is established, where the bionic impellers on both sides of the base point are arranged symmetrically, and i is the serial number of the bionic impellers arranged along the base point to the two banks of the river. N is the number of bionic impellers, the bionic impeller number i at the center of the river is 0, the half of the length L1 of the bionic impeller is the flow velocity calculation point, the center distance between two adjacent bionic impellers is L1+L2, and the length of the bionic impeller number i relative to the center position of the bionic impeller at the base point is i(L1+L2); According to the angle β between the water flow direction and the bionic impeller i And the length i(L1+L2) of the bionic impeller center relative to the base point, combined with the distribution curve of the bionic impeller center flow velocity, calculate the bionic impeller center flow velocity V i ; S4: According to the bionic impeller center flow velocity V i And the angle β between the water flow direction and the bionic impeller i , determine the effective flow velocity V of the bionic impeller i '; According to the effective flow velocity V of the bionic impeller i ' and the swept area S of the bionic impeller, combined with the Bates theory, the maximum output power P of the entire water energy collection device is calculated max总 ; S5: Calculate the angle β of each bionic impeller based on the CFD simulation value i The corresponding power P i , the simulated power P of the entire water energy collection device is obtained by accumulating m ' ax ; The simulated power P m ' ax and the maximum output power P max总 In comparison, if the proportion requirement is met, the bionic impeller is arranged according to the length L1 of the bionic impeller, the distance L2 between the bionic impellers, the number N of the bionic impellers and the angle α between the arc connecting line and the river bank; otherwise, go to step S1 and reset the parameters of the bionic impeller until the requirement is met.

2. The design method according to claim 1, characterized in that: In the bionic impeller, the value of the staggered angle γ between the two hubs is: 10°≤γ≤60°.

3. The design method according to claim 1, characterized in that: The value of the distance L2 between two adjacent bionic impellers is: 1.5L1≤L2≤2.5L1, where L1 represents the length of the bionic impeller.

4. The design method according to claim 1, characterized in that: The value of the angle α between the arc-shaped connecting line of several bionic impellers and the river bank is: 10°<α<90°.

5. The design method according to claim 4, characterized in that: The angle β between the bionic impeller and the water flow velocity direction i The value of: α≤β i ≤90°.

6. The design method according to claim 1, characterized in that: In step S3, the angle β between the water flow velocity direction and the bionic impeller is i =90°-iα3, where α3 is the decreasing compensation angle between the flow velocity and the impeller angle, and its value is related to the distance L2 between the bionic impellers, the average width B of the water energy capture, and the maximum flow velocity V max related.

7. The design method according to claim 1, characterized in that: In step S3, the bionic impeller center flow velocity 8. The design method according to claim 1, characterized in that: In step S4, the effective flow velocity V of the bionic impeller is i '=V i sinβ i The maximum output power P of the entire water energy collection device max总 The maximum output power P of a single bionic impeller max Add up and you get, Here, ρ represents the density of water.

9. The design method according to claim 1, characterized in that: In step S5, the ratio requirement is P' max =C1P max总 , the value of the proportional coefficient C1 is: 0.8≤C1≤1.2.

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