Small hydro power plant

Abstract

The present invention is a small hydroelectric power generation device installed in a flowing fluid, comprising a flow velocity accelerator (100) and a vertical cross-flow turbine (200) installed downstream of the same at a predetermined distance (L4), wherein the flow velocity accelerator (100) comprises: a first housing (110) formed in a truncated cone shape such that the diameter (D1) of the inlet port (111) is maximum and the diameter gradually decreases along the direction of fluid flow so that the diameter (D2) of the outlet port (112) becomes minimum; The present invention provides a small hydroelectric power generation device comprising a second housing (120) installed at a predetermined distance (L3) from the first housing (110), and formed in a bell shape such that the diameter (D3) of the inlet port (121) is maximum, gradually decreases along the direction of fluid flow until it forms a minimum diameter (D4), then begins to increase again so that the diameter of the outlet port (122) becomes larger than the minimum diameter (D4), and the diameter (D3) of the second housing inlet port (121) is larger than the diameter (D2) of the first housing outlet port (112).

Description

Technology Field

[0001] The present invention relates to power generation technology. Background Technology

[0003] Small-scale hydropower generation refers to a power generation device utilizing a water-flow turbine, specifically a small-scale hydroelectric power generation system with a facility capacity of 10,000 kW or less. While hydroelectric power generation is environmentally friendly, it has the disadvantage of significant locational constraints as it typically requires large rivers or reservoirs. In contrast, small-scale hydropower generation is a technology that does not require a large facility capacity, offering the advantage of being installable anywhere a water-flow turbine can be rotated. Another advantage is that installation and operating costs are lower compared to hydroelectric power generation; however, there is also a disadvantage in that it is significantly affected by surrounding environmental factors, such as season and precipitation, depending on the installation environment.

[0004] To compensate for the disadvantages of such small-scale hydropower generation, a flow accelerator can be used in conjunction. By installing a flow accelerator upstream of the water turbine to supplement the fluid velocity, the velocity of the fluid flowing into the turbine can be maintained at a constant level even under conditions where the season or precipitation is unsuitable.

[0005] Most fluid accelerators are based on the Venturi effect. This utilizes the phenomenon where fluid velocity increases and pressure decreases as it flows from a wide section to a narrow section of a pipe. This is explained by the fluid continuity equation and the Bernoulli equation.

[0006] Flow accelerators used in small-scale hydropower are formed solely of funnel-like tubes; however, they are limited in that they only accelerate the velocity of the fluid flowing into the wider section of the tube. In other words, because the flow rate itself is low, friction within the tube increases, and there is a limit to the increase in flow velocity. Furthermore, due to the nature of power generation devices, which are difficult to move or modify once installed, even a slight change in fluid flow prevents the velocity from accelerating to the desired level. If the flow velocity does not increase sufficiently, the power generation capacity is reduced accordingly.

[0008] (Patent Document 1) KR 10-1663248 B1

[0009] (Patent Document 2) KR 10-1314465 B1

[0010] (Patent Document 3) KR 10-1039504 B1

[0011] (Patent Document 4) KR 10-2527939 B1

[0012] (Patent Document 5) KR 10-1990-0014773 A The problem to be solved

[0014] The present invention aims to solve the above-mentioned problems by proposing a power generation method that can significantly increase the fluid velocity compared to conventional flow accelerators, thereby increasing the efficiency of small-scale hydropower generation.

[0015] In addition, we propose a power generation method that can be optimally controlled according to the fluid flow conditions at the site. means of solving the problem

[0017] One embodiment of the present invention for solving the above-mentioned problem is a small hydroelectric power generation device installed in a flowing fluid, comprising a flow accelerator (100) and a vertical cross-flow turbine (200) installed downstream of the same at a predetermined distance (L4), wherein the flow accelerator (100) comprises: a first housing (110) formed in a truncated cone shape such that the diameter (D1) of the inlet port (111) is maximum and the diameter gradually decreases along the direction of fluid flow so that the diameter (D2) of the outlet port (112) becomes minimum; The present invention provides a small hydroelectric power generation device comprising a second housing (120) installed at a predetermined distance (L3) from the first housing (110), and formed in a bell shape such that the diameter (D3) of the inlet port (121) is maximum, gradually decreases along the direction of fluid flow until it forms a minimum diameter (D4), then begins to increase again so that the diameter of the outlet port (122) becomes larger than the minimum diameter (D4), and the diameter (D3) of the second housing inlet port (121) is larger than the diameter (D2) of the first housing outlet port (112).

[0018] In addition, it is preferable that fluid flowing outside the first housing (110) flows into the space between the first housing (110) and the second housing (120), and flows into the second housing inlet (121) together with the fluid that has passed through the first housing outlet (112).

[0019] Additionally, the vertical cross-flow turbine (200) preferably includes a plurality of blades (210) that are installed vertically and rotate clockwise or counterclockwise on a horizontal plane; and a shaft (220) that transmits the rotational force of the blades (210).

[0020] In addition, it is preferable that the curve connecting the inner diameter of the second housing (120) be extended in the direction of fluid flow so as to come into contact with the radius of rotation of the outer edge of the plurality of blades (210).

[0021] Additionally, the extension line of the centerline of the first housing (110) and the second housing (120) passes through the center of the shaft (220) of the vertical cross-flow turbine (200), and it is preferable that a water flow guide (310) that blocks fluid flow is installed upstream of the fluid flow direction on one side of the vertical cross-flow turbine (200) based on the extension line.

[0022] In addition, it is preferable to install a debris remover (500) upstream of the above-mentioned flow accelerator (100).

[0023] In addition, the above-mentioned debris remover (500) is preferably L-shaped with an open surface along the direction of fluid flow.

[0024] Additionally, the length (L1) of the first housing (110) is 83% of the diameter (D1) of the first housing inlet (111), the length (L2) of the second housing (120) is 67% of the diameter (D1) of the first housing inlet (111), the gap (L3) between the first housing (110) and the second housing (120) is 4.2% of the diameter (D1) of the first housing inlet (111), the diameter (D2) of the first housing outlet (112) is 42% of the diameter (D1) of the first housing inlet (111), the diameter (D3) of the second housing inlet (121) is 58% of the diameter (D1) of the first housing inlet (111), and the second housing (120) It is preferable that the minimum diameter (D4) is 42% of the diameter (D1) of the first housing inlet (111). Effects of the invention

[0026] According to the present invention as described above, a flow accelerator that significantly increases the fluid velocity compared to conventional flow accelerators is adopted, thereby increasing the efficiency of small hydropower generation. As a result of fluid analysis, it was confirmed that the power generation efficiency increased by approximately 3.4 times.

[0027] In addition, it can be optimally controlled according to the fluid flow conditions at the site. Brief explanation of the drawing

[0029] FIG. 1 is a perspective view of a small hydropower generation device according to the present invention. FIG. 2 is a plan view of a small hydropower generation device according to the present invention. FIGS. 3 to 5 are the results of a verification experiment of a small hydropower generation device according to the present invention. Figure 6 is a photograph of a small hydropower generation device actually manufactured according to the present invention. FIG. 7 is a plan view of another embodiment of a small hydropower generation device according to the present invention. Specific details for implementing the invention

[0030] The present invention will be described in detail below with reference to the drawings. In the following description, the front side is referred to as upstream and the rear side as downstream based on the direction of fluid flow.

[0032] 1. Description of Small Hydroelectric Power Generation Devices

[0033] A small hydroelectric power generation device according to the present invention will be described with reference to FIG. 1.

[0034] The small hydroelectric power generation device according to the present invention is located in an environment where fluid flows, such as a river, stream, artificial waterway, fluid inlet, or wastewater discharge pipe, and is installed to be submerged in the fluid. Depending on the direction of fluid flow, it may further include a flow accelerator (100) and a vertical cross-flow turbine (200), a frame (300) that fixes and maintains them, and a debris remover (500) located upstream of the flow accelerator (100).

[0035] A small hydroelectric power generation device is installed in a river or stream where fluid flows, such as so that a flow accelerator (100) and a vertical cross-flow turbine (200) are submerged in the fluid. It is preferable that the frame (300) be firmly fixed to the bottom surface of the river or similar surface to keep them fixed.

[0036] The flow accelerator (100) is intended to increase the velocity of the fluid in a flow environment to enable efficient power generation and consists of two components: a first housing (110) and a second housing (120). Both the first housing (110) and the second housing (120) are fixed to a frame (300) using supports (301), etc. There are no limitations on the shape of the frame (300) or the number of supports (301).

[0037] The first housing (110) is formed in a truncated cone shape such that the diameter (D1) of the inlet (111) is maximum and gradually decreases along the direction of fluid flow so that the diameter (D2) of the outlet (112) becomes minimum. At this time, the diameter between the inlet (111) and the outlet (112) does not necessarily have to decrease linearly. In other words, the inlet side and the outlet side may be connected in a straight line in the cross-sectional view to form a trapezoid, but it is also acceptable for the inlet side and the outlet side to be connected in a curve as shown in FIG. 2.

[0038] Since the internal diameter of the first housing (110) decreases along the direction of fluid flow, the fluid flow velocity introduced through the inlet (111) gradually increases and passes through the outlet (112) at an outflow velocity that is greater than the inflow velocity and is discharged.

[0039] The second housing (120) is installed at a predetermined distance (L3) from the first housing (110).

[0040] The second housing is formed in a bell shape such that the diameter (D3) of the inlet (121) is maximum, and the diameter gradually decreases along the direction of fluid flow until it forms a minimum diameter (D4), and then starts to increase again so that the diameter of the outlet (122) becomes larger than the minimum diameter (D4).

[0041] Even though the first housing (110) and the second housing (120) are separated by a certain distance (L3), the diameter (D3) of the second housing inlet (121) is larger than the diameter (D2) of the first housing outlet (112), so the fluid discharged from the outlet (112) of the first housing (110) flows into the inlet (121) of the second housing (120) without loss of flow velocity (see FIG. 5).

[0042] Additionally, since the diameter (D3) of the second housing inlet (121) is larger than the diameter (D2) of the first housing outlet (112), some of the fluid flowing outside the first housing (110) flows into the inside of the second housing (120) through the space between the first housing (110) and the second housing (120). That is, the fluid passing through the inside of the first housing (110) flows into the second housing (120) at a high speed, and the fluid flowing outside the first housing (110) joins in here. Since the flow rate increases as much as it joins, this increases the velocity of the fluid discharged from the second housing (120).

[0043] After joining, the fluid flows inside the second housing (120), and as the diameter gradually decreases, the flow velocity becomes faster, reaching its fastest velocity when passing through the minimum diameter (D4) section (see FIG. 5). However, at this point, although the fluid velocity is fast, the area of ​​the fluid discharged at the fast velocity is narrowed to the minimum diameter (D4), so it is not suitable for rotating the turbine (200) at the rear end. Therefore, even if it reduces a slight loss in flow velocity, it is more suitable for power generation to discharge the fluid with an area suitable for rotating the blades (210) of the turbine (200), so the outlet (122) section of the second housing (120) is designed to have a larger diameter again. This is illustrated by a red arrow in FIG. 5.

[0044] In other words, by making the line extending the curve connecting the inner diameter of the second housing (120) in the direction of fluid flow (indicated by the dotted line in FIG. 2) touch the radius of rotation of the outer edge of the turbine blade (210) described later, the fluid discharged from the second housing (120) can be used to rotate the blade (210) while minimizing loss.

[0045] Accordingly, by forming a flow accelerator (100) with a configuration like that of the present invention, it is suitable for rotating a turbine (200) compared to the case where only the first housing (110) is used alone, or compared to the case where both the first housing (110) and the second housing (120) are formed in a conical shape with a smaller diameter.

[0046] Meanwhile, the vertical cross-flow turbine (200) is a place where high-speed fluid discharged through the outlet (122) of the second housing (120) flows in. It is configured as a vertically positioned cylinder, and inside there are a plurality of blades (210) that can rotate clockwise or counterclockwise and a shaft (220) connected thereto. The fluid rotates the blades (210), causing the shaft (220) to rotate, and a gearbox (not shown) and a power generation unit (not shown) are connected to the shaft (220) to generate power.

[0047] The extension line of the centerline of the first housing (110) and the second housing (120) (dotted line in FIG. 2) passes through the center of the shaft (220) of the vertical cross-flow turbine (200). At this time, it is preferable to install a water flow guide (310) that blocks fluid flow upstream of the fluid flow direction on one side of the vertical cross-flow turbine (200) relative to the extension line. Through this, the fluid flow can be guided only to a part relative to the extension line of the vertical cross-flow turbine (200), thereby preventing the phenomenon where the fluid flow hinders rotation.

[0048] Here, a vertical cross-flow turbine (200) can be formed by providing an intermediate surface between the upper surface and the lower surface, and if the upper plate, lower plate, and middle plate are respectively, holes are formed in the parts where blades (210) are installed in each of the three plates, and then a bent blade structure is inserted between each plate, fixed, and welded (see FIG. 7). At this time, if the diameter of the entire turbine is d1, the diameter of the turbine excluding the blades (210) is d2, the curvature of the bent blade (210) structure is R, and the spacing between each blade (210) is T, then the most efficient shape of the blade (210) can be determined by the formula as shown in FIG. 7.

[0049] Meanwhile, it is preferable to install a debris remover (500) upstream of the fluid flow direction of the flow velocity accelerator (100). This prevents the phenomenon where debris from the river or stream enters the device and hinders power generation or causes equipment failure when the small hydroelectric power generation device according to the present invention is installed in a river or stream. However, if positioned perpendicular to the fluid flow direction, the flow velocity of the river or stream may be reduced, and in this case, the power generation efficiency is lowered; therefore, it is preferable to form it in an L-shape with an open surface along the fluid flow direction as shown in the drawing.

[0051] 2. Verification experiment

[0052] The inventors manufactured an actual device as shown in FIG. 6 and performed a verification experiment. FIG. 6 (a) is a photograph of the first housing (110) and frame (300) of the flow accelerator (100), (b) is a photograph of the second housing (120) and frame (300), (c) is a photograph of the debris remover (500), and (d) is a photograph of the demonstration product of the vertical cross-flow turbine (200).

[0053] Meanwhile, as shown in FIG. 3, CFD was performed while varying the diameter (D1) of the first housing inlet (111), the diameter (D2) of the first housing outlet (112), the length (L1) of the first housing (110), the diameter (D3) of the second housing inlet (121), the minimum diameter (D4) of the second housing (120), the length (L2) of the second housing (120), and the gap (L3) between the first housing (110) and the second housing (120). FIG. 4 and FIG. 5 illustrate an example of such CFD results.

[0054] Based on case S, in cases (S, A1, A2) where the diameter (D1) of the first housing inlet (111) was changed, the outflow speed was faster when the size was 100% (1,200 mm) of the D1 standard size than when it was smaller. In cases (S, B1) where the diameter (D2) of the first housing outlet (112) was changed, no significant difference was observed. In cases (S, C1, C2, C3) where the length (L1) of the first housing (110) was changed, the results were good when the size was 42% (500 mm) or 83% (1,000 mm) of the D1 standard size. In cases (S, D1, D2) where the minimum diameter (D4) of the second housing (120) was changed, the results were better as the minimum diameter became smaller. In cases (S, E1, E2, E3, E4) in which the gap (L3) between the first housing (110) and the second housing (120) was varied, the results were good when the size based on D1 was 4.2% (50mm) or 8.3% (100mm). A negative L3 means that the first housing (110) and the second housing (120) are arranged to partially overlap.

[0055] Among the results of the verification experiment above, it was confirmed that when the minimum diameter (D4) of the second housing (120) is reduced, the flow velocity increases, and thus the flow velocity of the outflowing fluid increases. However, if it becomes too small, it is expected that the flow accelerator (100) will become clogged or difficult to manufacture due to foreign substances such as unfiltered debris.

[0056] Accordingly, reflecting this, when the inflow velocity is 6 m / s, the length (L1) of the first housing (110) is 83% (1000 mm) of the size based on D1, the length (L2) of the second housing (120) is 67% (800 mm) of the size based on D1, the gap (L3) between the first housing (110) and the second housing (120) is 4.2% (50 mm) of the size based on D1, the diameter (D1) of the first housing inlet (111) is 100% (1200 mm) of the size based on D1, the diameter (D2) of the first housing outlet (112) is 42% (500 mm) of the size based on D1, the diameter (D3) of the second housing inlet (121) is 58% (700 mm) of the size based on D1, and the minimum of the second housing (120) The shape of the flow accelerator (100) was determined as a C3 case with a diameter (D4) that is 42% (500 mm) of the size of D1. In this case, it was confirmed that if the flow accelerator (100) according to the present invention is located in a river or stream where fluid is flowing at a speed of 6 m / s, the fluid is discharged at a speed of 12.4 m / s, so a speed gain of approximately 207% can be obtained. In this case, the power generation efficiency increases by approximately 3.4 times.

[0058] 3. Explanation of the control method for small hydropower generation devices

[0059] It was confirmed through a verification experiment that a velocity gain of approximately 207% occurs during the process of passing through the velocity accelerator (100), and more efficient control is possible by changing the arrangement of the velocity accelerator (100) used at this time. This will be determined by the fluid flow.

[0060] For example, if the fluid flows at a low speed, if laminar flow occurs, or if the fluid flows diagonally contrary to the expected flow direction, the layout can be modified to optimally accelerate the flow velocity. Conversely, if the fluid flows at too high a speed and exceeds the upper limit of the power generation unit's capacity, the flow velocity of the discharged fluid can be controlled to prevent it from becoming too fast in order to protect the durability of the power generation unit.

[0061] The small hydropower generation device can be controlled by the following method.

[0062] First, the gap (L3) between the first housing (110) and the second housing (120) can be adjusted. At an inflow velocity of 6 m / s, L3 being 50 mm was optimal, but if the inflow velocity decreases or increases, the gap (L3) can be narrowed or widened to check the optimal condition. To this end, a separate actuator (not shown) capable of moving the first housing (110), the second housing (120), or both in the direction of fluid flow may be provided.

[0063] Second, the gap (L4) between the flow accelerator (100) and the vertical cross-flow turbine (200) can be adjusted. This, like the first case, can also be controlled to find optimal conditions for fluid flow by a separate actuator (not shown) provided in the flow accelerator (100).

[0064] Third, the flow accelerator (100) can be moved to the left or right relative to the extension line (center line in FIG. 2) where the fluid flows. This is effective when the fluid flow is diagonal, unlike the expected direction of fluid flow. It can be controlled to find optimal conditions for fluid flow by an actuator (not shown) equipped in the flow accelerator (100) or the vertical cross-flow turbine (200).

[0065] Fourth, the vertical cross-flow turbine (200) can be moved up and down. This is effective when the fluid flow is laminar, or when the water depth of a river or stream is lower or higher, and the power generation efficiency varies depending on the height of the turbine (200). Likewise, the vertical cross-flow turbine (200) can be controlled to find optimal conditions according to the fluid flow by means of an actuator (not shown) provided in the vertical cross-flow turbine (200).

[0066] Fifth, the gear ratio of a gearbox (not shown) connected to the shaft (220) can be controlled. In particular, if the inflow velocity is excessively fast and may cause problems with the durability of the power generation unit, stable high power generation efficiency can be achieved under conditions that maintain the durability of the power generation unit by adjusting the gear ratio.

[0068] 4. Other embodiments

[0069] In another embodiment of the present invention, as shown in FIG. 7, two fluid flow meters may be applied to a single turbine (200). In this case as well, the first housing (110a, 110b) and the second housing (120a, 120b) must be spaced apart. In order not to interfere with the rotational force of the turbine (200), they may not be arranged symmetrically with respect to an extension line, and it is necessary to arrange them appropriately in the fluid flow environment in which they are installed. Explanation of the symbols

[0071] 100: Flow accelerator 110: 1st Housing 111: 1st Housing Inlet 112: 1st Housing Outlet 120: 2nd Housing 121: 2nd Housing Inlet 122: Second housing outlet 200: Vertical cross-flow turbine 210: Blade 220: Shaft 300: Frame 301: Support 310: Water Flow Guide 500: Debris remover L1: 1st housing length L2: Second housing length L3: Housing spacing D1: Diameter of the first housing inlet D2: Diameter of the first housing outlet D3: Diameter of the 2nd housing inlet D4: Minimum diameter of the second housing L4: Flow accelerator turbine spacing

Claims

Claim 1 A small hydroelectric power generation device installed in a flowing fluid, comprising a flow accelerator (100) and a vertical cross-flow turbine (200) installed downstream of the same at a predetermined distance (L4), wherein the flow accelerator (100) comprises: a first housing (110) formed in a truncated cone shape such that the diameter (D1) of the inlet (111) is maximum and the diameter gradually decreases along the direction of fluid flow so that the diameter (D2) of the outlet (112) becomes minimum; A small hydroelectric power generation device comprising a second housing (120) installed at a predetermined distance (L3) from the first housing (110), and formed in a bell shape such that the diameter (D3) of the inlet port (121) is maximum, gradually decreases along the direction of fluid flow until it forms a minimum diameter (D4), then begins to increase again so that the diameter of the outlet port (122) becomes larger than the minimum diameter (D4), wherein the diameter (D3) of the second housing inlet port (121) is larger than the diameter (D2) of the first housing outlet port (112). Claim 2 A small hydroelectric power generation device according to claim 1, wherein a fluid flowing outside the first housing (110) flows into the space between the first housing (110) and the second housing (120), and flows into the second housing inlet (121) together with the fluid that has passed through the first housing outlet (112). Claim 3 In claim 2, the vertical cross-flow turbine (200) comprises a plurality of blades (210) installed vertically and rotating clockwise or counterclockwise on a horizontal plane; and a shaft (220) that transmits the rotational force of the blades (210), forming a small hydroelectric power generation device. Claim 4 A small hydroelectric power generation device according to claim 3, wherein extending the curve connecting the inner diameter of the second housing (120) in the direction of fluid flow contacts the radius of rotation of the outer edge of the plurality of blades (210). Claim 5 A small hydroelectric power generation device according to claim 3, wherein the extension line of the centerline of the first housing (110) and the second housing (120) passes through the center of the shaft (220) of the vertical cross-flow turbine (200), and a water flow guide (310) that blocks fluid flow is installed upstream of the fluid flow direction on one side of the vertical cross-flow turbine (200) based on the extension line. Claim 6 A small hydroelectric power generation device according to claim 2, wherein a debris remover (500) is installed upstream of the flow velocity accelerator (100). Claim 7 In claim 6, the impurity remover (500) is a small hydroelectric power generation device having an L-shaped open surface along the direction of fluid flow. Claim 8 In claim 2, the length (L1) of the first housing (110) is 83% of the diameter (D1) of the first housing inlet (111), the length (L2) of the second housing (120) is 67% of the diameter (D1) of the first housing inlet (111), the gap (L3) between the first housing (110) and the second housing (120) is 4.2% of the diameter (D1) of the first housing inlet (111), the diameter (D2) of the first housing outlet (112) is 42% of the diameter (D1) of the first housing inlet (111), the diameter (D3) of the second housing inlet (121) is 58% of the diameter (D1) of the first housing inlet (111), and the second A small hydroelectric power generation device in which the minimum diameter (D4) of the housing (120) is 42% of the diameter (D1) of the first housing inlet (111).

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