JPS5888470A - Water level adjusting device for through-flow water wheel - Google Patents

Abstract

PURPOSE:To maintain efficiency of a water wheel at high level by providing a mechanism which carries out intake and exhaust motion to a space above water surface below a runner in a casing to adjust water level for placing automatically water surface position below the runner within a proper height range. CONSTITUTION:In a through-flow water wheel which receives water 3 having positional energy at a runner 1 to give work to the runner 1 and then flows out the water 3, a water surface cylinder 14 communicating to water surface is provided at a portion of the outside of a casing 6 downstream of the runner 1. The water surface cylinder 14 is opened to the atmospheric side at the upper portion and floats a float 15 in the interior. A valve body 17 connected to the float 15 through a connecting shaft 16 is normally sealed on a vlave seat 18 and moved upward to open the valve seat 18 as the float floats up when the water surface below the runner 1 rises from the optimum water level so that the atmosphere is absorbed into the casing 6 to lower the water level.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water level adjustment device for a once-through water turbine, and in particular, the present invention relates to a water level adjustment device for a once-through water turbine. This invention relates to a water level adjustment device for a once-through water turbine, which controls the water level within an appropriate height range.

In a once-through turbine, the air inside the casing is drawn into the water by jets from the runner, causing fluctuations in the water surface below the runner. For example, as shown in Fig. 1, if the height of runner 1}{s is set higher than the water level of water discharge surface 2 by υ, water 3 flowing in from the upstream side of runner 1
(Water level H) gives work to the runner and then flows out. In this case, as shown in FIG. 2, the high-speed jet 4 flowing out from the runner 1 collides with the water surface 5 below the launch and entrains the air inside the casing 6. Therefore, the air 7 in the tongue 6 mixes into the water below the runner 1 as many bubbles, but some of the bubbles float to the surface due to buoyancy, while others are released with the downward flow in the suction pipe. Ejected into waterways. As the amount of air inside the casing 6, and hence the air pressure, gradually decreases, the water level below the runner gradually rises, and eventually a portion of the runner 1 is submerged in this water surface, and the rotational energy of the runner is absorbed into the water, causing the water wheel to rotate. It reduces efficiency and tends to disturb the water surface. For this reason, in conventional once-through water turbines, a spring-type intake valve 8 is installed at the top of the casing 6, and the force of the spring is adjusted so that air is taken in when the air pressure inside the casing 6 drops below a certain value, thereby reducing the water surface below the launch. The height is adjusted within a predetermined range. However, even if the spring is adjusted so that the height of the water surface below the launch becomes the optimum water level of 5M at a certain tailwater level of 2M, when the water level changes to 2H, the water level in the casing 6 will rise to 5H. As a result, a part of the runner 1 will be submerged in water. In addition, when the water discharge level drops to 2L, the water level below the runner drops to 5L, and the head difference between the water levels 5M and 5L is wasted. Therefore, in order to maintain the water surface below the runner at the optimal height of 5M, the spring force of the intake valve 8 must be adjusted as the water level changes, but the intake valve 8 cannot be adjusted manually. Therefore, it is generally extremely difficult to make adjustments in practice.

Furthermore, as shown in FIG.
Since some of the water is contained in the water flowing down the suction pipe as air bubbles and disappears, the water level below the runner gradually rises and finally comes into contact with the runner 1. In such a case, the pressure of the air 7 inside the casing 6 is higher than the atmospheric pressure, so in order to properly control the height of the water surface below the runner,
For example, it is necessary to provide means for detecting the water surface position below the lunch with the water level detector 9, driving the compressor 1o with separately provided power, and forcefully feeding air into the casing 6.

Furthermore, when it is necessary to consider the installation position of the water tank both above and below the discharge water level, adjusting devices such as an intake valve, a compressor, and a water level detector may be installed to ensure that the discharge water level is By operating the intake valve based on the detection signal when the temperature is lower than the runner,
Furthermore, when the discharge water level is higher than the runner, it is conceivable to control the water level below the runner to an optimal height by operating a compressor based on the detection signal.

However, in this case, there are problems such as difficulty in adjusting the intake valve, etc., and installation of a compressor operated by separate power, making it difficult to control the runner water level, increasing the equipment cost of the water turbine, and reducing the casing. The disadvantage is that the structure of the mawashi becomes complicated.

The purpose of the present invention is to overcome the drawbacks of the prior art and to provide a water level adjustment device for a once-through water turbine that can automatically control the water surface position below the launch and the height within an appropriate range with a simple structure. It is about providing.

That is, the present invention provides a once-through water turbine which is designed to control the water level below the launch of a once-through water turbine in which the height of the water discharge surface relative to the height of the lower end of the runner inside the casing changes within an appropriate range of heights. The water level adjustment device is provided with a mechanism that adjusts the water level by performing suction and exhaust operations on the space above the water surface below the runner inside the casing, and this mechanism is directly responsive to changes in the water level below the runner. It is characterized by being made to cause

Embodiments of the present invention will be described in detail below based on the drawings.

Figures 4 through 6 show an embodiment of the invention suitable for controlling the water level below the runner when the water level is lower than the runner installation position.

A water surface cylinder 14 communicating with the water surface is provided outside the casing at a portion of the casing 6 on the downstream side of the runner (FIG. 5). As shown in FIG. 6, the water surface cylinder 14 communicates with the water surface below the runner at its lower part and opens to the atmosphere at its upper part. A float 15 having a height of the water surface below the runner (5L, 5M, 5FK) is floated on the water surface cylinder 14, and the float 15 supports a valve body 17 above it via a connecting shaft 16. The valve body 17 is in contact with a valve seat 18 provided above the water surface cylinder 14, and the water surface below the runner is at the optimum water level (
5M) to the water level above it (5H), the float 15 rises and moves upward, releasing the valve seat 18 and sucking the atmosphere 19 into the casing 6 to lower the water level. Control. Furthermore, when the water level drops from its optimum water level (5M) to a lower water level (5L), the float 15 separates from the water surface and loses its buoyancy, causing the valve body 17 (and float 15) to descend under its own weight, causing the valve seat 18 to fall. is closed to block atmospheric air from being drawn into the casing 6. Therefore, as the air in the casing 6 is stirred and mixed into the water by the jet from the runner 1 and discharged into the waterway, the water surface is controlled in a direction toward the optimum water level (5M).

7 to 9 show the detailed shape of one specific example of the valve body 17. FIG. 7 shows the valve in a fully closed state, FIG. 9 shows the valve in a fully open state, and FIG. 8 shows an intermediate state.

The dimensions of each part of the valve are set as follows: π(DI
+ΔR+)・ΔR1<π(D2+ΔR2)・ΔR2<1
(D, +2ΔR,) In the state shown in FIGS. 7 and 8, the intake amount of the air 19 is determined by the radial clearance ΔR1 between the valve body 17 and the valve seat 18 and the overlapping length of the two. The states shown in FIGS. 8 to 9 are similarly determined by the radial clearance ΔR2 and the overlapping length of the two.

When the state shown in Fig. 9 is exceeded, the intake air amount increases rapidly and the valve seat 18
is constant at an amount corresponding to the pore cross-sectional area.

10 and 11 show other specific detailed shapes of the valve body 17. DF of each main part in this case Fig. 12 shows the operating characteristics of the two types of valve bodies shown in Figs. This is a graph showing the curve Ai No. 7.
The curve B of the valve body shown in FIGS. 10-11 represents the characteristics of the valve body shown in FIGS. 10-11, respectively. As is clear from the figure, in each valve body, the intake air amount gradually increases linearly or in a broken line with the upward stroke of the float, and after a certain predetermined stroke, it rapidly increases and settles at a constant value. The water level below the runner is controlled so as not to rise above a certain height.

In this embodiment, the water surface pipe 14 is provided in the casing 6 of the once-through turbine, and the water surface pipe 14 is provided with a valve seat 18 that communicates with the water surface below the runner 1 at the lower part and communicates with the atmosphere side at the upper part. The valve seat 18 is opened and closed by the valve body 17 that moves up and down together with the float 15 floating in the cylinder 14 to control the intake of air into the casing 6, so that the water level below the runner is lower than the optimum water level. When the float 15 rises, the valve body 17 becomes a valve.
Seat 18 is opened to introduce atmospheric air into one casing 6 to lower the water level to the optimum water level again, and when the water level still falls below the optimum water level, valve seat 18 is closed to gradually bring the water level to the optimum water level. can be raised. Since this water level control is based on a float valve mechanism consisting of a float 15 and a valve body 17 that move up and down in direct response to changes in the water level below the runner, the water level is always adjusted automatically without requiring any operations. Maintained at optimum water level.

Similarly, in the above example, the water surface tube is provided outside the casing, but it is also possible to install it inside the casing, and FIGS. 13 and 14 show such another embodiment. The cover 20, which has a substantially circular cross section, is intended to prevent the jet flow from the runner 1 from directly hitting the float, thereby reducing fluid resistance. Furthermore, as shown in the figure, when the runner 1 is divided into a wide channel 21 and a narrow channel 22, the time for water to flow through the narrow channel 22 is generally shorter, so the water level can be reduced. It is provided on the side of the dovetail flow path and positioned at a corner of the casing 6 to facilitate its support. The other components, such as the float 15 and the valve body 17, are constructed in the same manner as the respective parts indicated by the corresponding symbols in the embodiment described above, and have the same functions. Generally, the installation surface of the casing is limited as much as possible for economic reasons, but this embodiment can fully satisfy such requirements.

FIG. 15 shows another embodiment of the invention suitable for controlling the water level below the runner when the water level is higher than the water level. In such a case, since the air inside the casing is normally higher than atmospheric pressure, some energy is required as described above to introduce outside air into the casing to control the water level below the runner.

In this embodiment, as shown in FIG. 15, an outer intake pipe 23 is provided which communicates the space above the water surface below the runner inside the casing 6 with the outside air side.

A jet pipe 26 is opened on the water surface side of the outer intake pipe 23 to guide a jet 24 of a high-speed jet flow from the downstream wall 25 of the upper waterway of the runner 1.

As shown in FIGS. 16 and 17, the jet pipe 26
Inside is a jet 24 that is part of the high-speed jet from runner 1.
flows with great high-speed energy and is ejected from the lower end of the outer intake pipe 23 onto the water surface below the launch. Here, as shown in FIG. 16, when the water surface has fallen to a height L lower than the appropriate water level and is separated from the intake outer pipe 23, there is a gap between the jet 24 from the jet pipe 26 and the intake outer pipe 23. jet 2
A complete ring-shaped gas phase exists around 4, and almost no jet pump action occurs. However, the air inside the casing rises through the outer intake pipe 23 as backflow air 27 and flows out of the casing 6, and as a result, the water level below the runner rises in a direction toward the optimum water level. Additionally, as shown in Fig. 17, the water level below the runner rises and the outer intake pipe 2
If the jet is located above the lower end of the jet 2,
4 produces a jet pump action to draw in the atmosphere outside the casing-6. A portion of this air rises in the form of bubbles, increases the amount of air in the casing 6, and therefore the air pressure, and lowers the height of the water surface toward the optimum water level.

As shown in FIG. 18, if the water level below the runner rises excessively for some reason, there is a risk of overflowing to the outside of the casing through the outer intake pipe 23. A float type valve 28 is provided above to prevent such overflow.

As described above, in this embodiment, the intake outer pipe 23 is provided to connect the space above the water surface below the runner of the once-through turbine casing 6 with the outside air inside the casing 6, and the high-speed jet on the downstream side of the runner 1 is provided. Since a jet pipe 26 is provided to guide the jet 24 to the water surface side below the runner of the outer intake pipe 23, the jet 2
Control the water level in a downward direction by generating a jet pump action by 4 and sucking outside air into the casing 6 through the intake outer pipe 23, and then discharging the air in the casing 6 by stopping this jet pump action. The rise of the water surface can be controlled by As a result, the water surface below the runner can be automatically controlled to the optimal position according to changes in the water surface height, and the intake energy required for this can be obtained from the runner without any special power source. This can be provided by a jet pump that utilizes the velocity energy of the jet 24 ejected at high speed. Therefore, according to the present invention, when the runner is installed below the tailwater level, the water level below the runner can be controlled automatically and precisely, and a special power source for this control is omitted. be able to.

FIG. 19 shows yet another embodiment of the present invention suitable for appropriately controlling the water level below the runner when the water level varies from a higher position to a lower position than the runner installation position.

In the figure, the casing 6 of the once-through water turbine is provided with a float valve mechanism consisting of a float 15, a valve body 17, etc., and a jet pump consisting of an outer intake pipe 23, a jet pipe 26, etc., similar to those in the previous embodiments. . The float valve mechanism is used, for example, to control the water level when the water discharge level is lower than the runner installation position and the air pressure inside the casing 6 is lower than the atmospheric pressure, as explained and explained in the embodiments shown in FIGS. 4 to 6. The jet pump is also used to control the water level when the water discharge level is higher than the runner setting position and the air pressure inside the casing 6 is higher than atmospheric pressure, as explained with reference to FIGS. 15 to 18. A water level detector 29 is provided to detect the height of the discharge water level with reference to the runner installation position, and this detection signal selectively operates the float valve mechanism and valves 30 and 31 respectively attached to the jet pump. There is.

When the discharge water level is low, only the valve 30 is opened in response to a detection signal from the water level detector 29, and the water level below the runner is adjusted by opening and closing the valve body 17. When the discharge water level is high, only the valve 31 opens in response to the detection signal, and the water level below the runner is adjusted by the jet pump action of the jet stream from the jet pipe 26.

According to this embodiment, the water level below the runner can be controlled to an appropriate value regardless of whether the water level is higher or lower than the launch installation, and these two aspects of control can be automatically controlled. This can be done selectively.

According to the device of the present invention, the water surface below the runner of a once-through turbine can be automatically adjusted to an appropriate water level without adding special control power when the discharge water level relative to the runner installation position can change. can be controlled.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are explanatory diagrams showing the operation mode of a once-through water turbine, FIG. 3 is an explanatory diagram showing an example of a runner water level adjustment device for a once-through water turbine, and FIG. 4 is an explanatory diagram of an embodiment of the present invention. 5 is a cross-sectional view of the embodiment, FIG. 6 is a vertical sectional view of the main part of the embodiment, and FIGS. 7 to 9 are detailed views of a specific example of the valve body used in the embodiment, 10 and 11 are detailed views of another specific example of the valve body used in the embodiment, FIG. 12 is an explanatory diagram showing the operating characteristics of each valve body, and FIG. 13 is another embodiment of the present invention. FIG. 14 is a cross-sectional view of the embodiment shown in FIG. 13, FIG. 15 is an mA diagram of still another embodiment of the present invention, and FIGS. FIG. 19 is an explanatory diagram showing the operating mode of the main parts of the embodiment, and FIG. 19 is an explanatory diagram of a further different embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Runner s 5Ll 5Ml 5H...Water surface water level below the lunch, 6...Casing, 14...Water level pipe, 15...Float, 17...Valve body, 23...
Intake outer pipe, 24...Jet, 26...Jet pipe, 29...Water level detection tube. Early 10th ll Mouth LV - th/? 1

Claims (1)

[Claims] 1. The water level below the runner of a once-through turbine is controlled to an appropriate range of height, in which the height of the water discharge surface relative to the height of the lower end of the runner inside the casing can vary. In a water level adjustment device for a once-through water turbine, a mechanism is provided for adjusting the water level by performing suction and exhaust operations on the space above the water surface below the runner inside the casing, and this mechanism is used to adjust the water level below the runner. 1. A water level adjustment device for a once-through water turbine as described above, characterized in that the water level adjustment device is adapted to respond directly to the flow. 28 The mechanism for adjusting the water level includes a jet pipe that guides a part of the jet flow from the runner to a part that communicates between the inside of the casing and the outside air side, and an opening/closing mechanism that controls opening and closing of this communication part. A patented water level adjustment device for a once-through water turbine, characterized in that it consists of a jet pump that adjusts the height of the lower end and adjusts when the discharge water level is high. 3. The mechanism for adjusting the water level communicates with the water surface below the runner and connects the inside of the casing with the outside air side, and opens and closes this communicating part in accordance with the movement of the float. Claim 1: The front station comprises a flow valve mechanism which is equipped with a control opening/closing valve and which performs an adjustment operation when the discharge water level is lower than the height of the lower end of the runner. Water level adjustment device for once-through water turbines as described in Section 1. 4. The mechanism for adjusting the water level includes a jet pipe that guides a part of the jet flow from the runner to a part that communicates between the inside of the casing and the outside air side, and an opening/closing mechanism that controls opening and closing of this communication part. A jet pump, a float provided in a portion that communicates with the water surface below the runner and communicates the inside of the casing with the outside air side, and an on-off valve that controls opening and closing of this communication portion according to movement of the float. It has a float valve mechanism, and the jet pump and the float valve mechanism are configured to selectively perform adjustment operations when the water discharge level is higher and lower than the height of the lower end of the runner, respectively. A patented water level adjustment device for once-through water turbines.