CN2583385Y - Archimedean screw rotary wheel - Google Patents

Abstract

The utility model provides an Archimedes spiral runner used in the fields of hydroelectric power generation and the like. Including the water inlet and the water outlet, the blades located in the runner are characterized in that the flow channel between adjacent blades is an Archimedes spiral flow channel, and there is a projection on the cross section of the runner along the direction of the flow channel in the flow channel as The line of the Archimedes spiral. The utility model is used for hydropower generation on ships, warships and submarines. Efficient, water-saving, and stable operation, it converts the energy of water flow into rotating mechanical energy to drive the generator to generate electricity.

Description

Archimedes screw wheel

Technical field:

The utility model relates to energy conversion equipment used in fields such as hydroelectric power generation, in particular to an Archimedes spiral runner of a water turbine.

Background technique:

There are two types of turbines: impact turbines and impact turbines. The impact turbine is a bucket or vane of the water turbine that is impacted by high-speed water flow to convert the kinetic energy of the water flow into rotational mechanical energy. The impact turbine is the pressure energy and kinetic energy of the water flow that are converted into mechanical energy in the flow channel of the runner. Francis turbine is a kind of impact water turbine, and most large and medium-sized hydropower stations use Francis turbine.

A runner using "X-shaped blades" (Fig. 9) is shown in (Fig. 10). (Fig. 8) is a schematic diagram of the work of the Francis turbine. Water flows through the volute, enters the runner radially through the water guide mechanism, and flows out of the runner axially after doing work in the "X-shaped blade" flow channel.

The unit of Yantan Hydropower Station was designed and manufactured by my country. The first unit was put into operation in 1992. It was found that the pressure fluctuation amplitude in the flow channel was large, the operation was unstable, and the blade cracks and other problems caused domestic Special attention has been paid to the stable operation of large Francis turbines. In the late 1990s, the large-scale Francis turbines that had been put into operation in China all experienced unstable operation to varying degrees. The root cause was that the hydraulic performance of the turbines was unstable. The model test of the turbine of the Three Gorges Hydropower Station also showed that in the area of high water head and small flow, the amplitude of water pressure fluctuation in the flow channel is large, and it is expected that the prototype will not be able to operate stably within the normal operating range.

The pressure and flow field distribution of the "X-blade" runner changes with the water head and flow, which is one of the important reasons for pressure pulsation and unstable operation.

Utility model content:

The purpose of the utility model is to overcome the above disadvantages and provide an Archimedes spiral runner which is efficient, water-saving, runs smoothly, and converts the energy of water flow into rotating mechanical energy to drive a generator to generate electricity.

The purpose of this utility model is achieved like this:

The utility model of the Archimedes spiral runner includes a water inlet and a water outlet, and the blades located in the runner are characterized in that the flow channel between the adjacent blades is an Archimedes spiral flow channel, and the flow channel along the direction of the flow channel has A line whose projection on the cross-section of the wheel is an Archimedean spiral.

The above-mentioned Archimedes spiral is the projection of the intersection line between the inner side of the blade and the bottom surface of the flow channel on the cross section of the runner.

The above-mentioned Archimedes spiral is the projection of the intersection line between the outer side of the blade and the bottom surface of the flow channel on the cross section of the runner.

The above-mentioned Archimedes spiral is the projection of the center line of the Archimedes spiral channel on the cross section of the runner.

There are long blades and short blades among the above-mentioned blades, and the long blades and short blades are evenly distributed on the runner to ensure the balance of water inflow and outflow, and the operation is stable.

The above-mentioned water inlet of the runner has a bell mouth seat ring matched therewith.

Referring to Fig. 1 to Fig. 6, the trumpet seat ring of the utility model is connected with the water inlet pipe, the runner is connected with the main shaft of the generator, the water inlet pipe takes water at an appropriate height of the dam, the water inlet pipe passes through the dam and exits upward from the bottom of the dam, The water flow is injected axially into the runner from bottom to top, and the water flows in the Archimedes spiral channel to do work with pressure energy and kinetic energy to push the runner to rotate.

Referring to Fig. 7, a mathematical formula and a section of curve are introduced for reference. This formula is the polar coordinate equation of the Archimedes spiral, and this section of curve is the Archimedes spiral. One equation and one curve laid the theoretical foundation of this Archimedes spiral runner.

r=aθ

That is, the polar radius r is a linear function of the polar angle θ (radian value), and the arc length L of the spiral $L=a{\∫}_{{\mathrm{\θ}}_1}^{{\mathrm{\θ}}_2}\sqrt{1+{\mathrm{\θ}}^2}\mathrm{d\θ}$

(1) Three elements of the utility model Archimedes spiral runner running smoothly

1. Because the polar radius r is a linear function of the polar angle θ, the force F does work in the flow channel, pushing the runner to move in a uniform circular motion. Changing the flow rate, changing the flow rate, and changing the magnitude of the force can change the speed of the runner.

2. In the whole process from the moment when the water flows into the runner in the axial direction until it flows out of the runner, the force F is always symmetrical with the axis and expressed in the form of a force couple.

3. The Archimedes spiral flow channel "regulates" the "behavior" of the water flow, and the water flow can only exert force and do work in the flow channel. Having a "rail" without a "rail" is one of the notable differences from other runners.

The distribution of pressure and flow field is reasonable, which weakens the conditions for pressure pulsation. Therefore, the Archimedes spiral runner can operate stably no matter the water head is high or low and the flow rate is large or small.

(2) Efficiency of the Archimedes spiral runner

1. First understand a project example:

The Three Gorges Hydropower Station uses the Francis turbine imported from Norway and Canada (Fig. 8), its efficiency η _t = 94.51%, runner diameter D = 9.8m, speed n = 75 rpm, rated water head H = 80.6m, rated flow Under the condition of Q=991.8m ³ /sec, its rated output power P:

P＝9.81η _t η _g Q·H＝710,000KW

In the formula, η _g is the efficiency of the generator, and η _g = 96%. The formula clearly tells us that the efficiency of the water turbine and the generator is very high, and the space away from the limit value 1 is very small. Flow increases power, is there any other way to go?

2. Build a hydroelectric power station using the Archimedes screw runner as shown in Figure 5

Runner diameter still adopts D=9.8m, keep n=75 rev/min (1.25 rev/s), runner water inlet pipe diameter d=6.6m, corresponding circle area S=34m ² , at rated water head H=80.6m Under the conditions, the pressure F at the inlet of the runner=80.6m×34m ² ×1000Kg/m ³ =2740400Kg

For power, we can change the algorithm 1KW=102Kg m/s

P＝2740400Kg×9.8m×π×1.25 rev/s÷102Kg m/s

＝1.03 million KW

Deduct torque loss, friction loss, and various unforeseen losses by 30%

Then P=103×70%=720,000 KW.

(1) The water flow does work W along the Archimedes spiral channel (arc length L) $W={\∫}_{L}p(x,\mathrm{the\; y})\mathrm{dx}+Q(x,\mathrm{the\; y})\mathrm{dy}$

Every drop of water participates in doing work, and every drop of water works according to the above formula. Not wasting a drop of water, and allowing the energy of each drop of water to be converted into mechanical energy in the greatest possible way is one of the efficient water-saving measures of the Archimedes spiral runner.

(2) The torque M of the Archimedes screw wheel

M≈0.94FR

(3) According to the hydrodynamic Bernoulli equation

Z ₁ +P ₁ /γ+a ₁ V ₁ ² /2g＝Z ₂ +P ₂ /γ+a ₂ V ₂ ² /2g+h _w(1-2)

In the formula, Z ₁ is the position head; P ₁ /γ is the pressure head; a ₁ V ₁ ² /2g is the flow head;

Appropriately increase the flow velocity of water in the flow channel, and increase the proportion of kinetic energy in "pressure energy and kinetic energy". This is the second measure to improve efficiency. The flow velocity of water in the water inlet pipe is 6 m/s∽9 m/s. The flow velocity of water in the Archimedes runner channel is 14 m/s∽28 m/s.

In a nutshell, the water flow works hard in the Archimedes channel, which forms the largest torque on the runner, and appropriately increases the flow velocity in the channel. These three factors are different from other runners, and the root of the efficiency is much higher than other runners.

(3) See (Fig. 6) for construction of a Francis hydroelectric power station using the Archimedes screw runner.

The water flows through the volute, flows into the runner radially through the water guiding mechanism, and flows out of the runner axially through the Archimedes spiral flow channel. Its efficiency is still higher than the "X-blade" Francis turbine, and it can run smoothly.

From the above analysis, it can be seen that the runner of the present invention overcomes the deficiencies of existing runners, can be efficient, save water, run smoothly, and convert the energy of water flow into rotating mechanical energy to drive a generator to generate electricity.

Use mechanical energy (engine) to drive the Archimedes spiral runner to rotate, and then the water flow is ejected axially. The reaction force of the water jet can be used to propel ships, warships, and submarines forward, and the speed of the ship can be increased under the same horsepower, or the power can be saved under the same speed of the ship.

Description of drawings:

Fig. 1 is the schematic diagram of the structure of the utility model runner.

Fig. 2 is a sectional view of A-A in Fig. 1 .

Fig. 3 is a working schematic diagram of the runner of the utility model.

Fig. 4 is a B-B sectional view in Fig. 3 .

Fig. 5 is a schematic diagram of the Archimedes screw runner hydroelectric power station.

Fig. 6 is a working schematic diagram of the Archimedes screw runner Francis turbine.

Fig. 7 is a schematic diagram of the formation of the Archimedes spiral.

Fig. 8 is a working schematic diagram of an existing Francis turbine.

Fig. 9 is a structural schematic diagram of "X-shaped blade".

Fig. 10 is a structural schematic diagram of an existing Francis runner.

Detailed ways:

Referring to FIG. 1 , the Archimedes spiral runner includes a fixed bell mouth seat ring 1 and a rotating wheel 2 that rotates on a shaft, and an appropriate gap is maintained between the bell mouth seat ring 1 and the runner 2 . There is a water inlet 3 along the axial direction on the runner, and water outlets 4 and 5 are symmetrically distributed along the radial direction.

FIG. 2 is a cross-sectional view along line A-A of FIG. 1 . From the profile view, there are 16 Archimedes spiral blades, the long and short blades are evenly distributed in half, 6 represents short blades, and 7 represents long blades. The Archimedes flow channel 8 is formed between the long and short blades. There must be one and only one projection on the cross section along the flow channel as an Archimedes spiral. This spiral can be the inner line of the blade or the inner line of the blade. The projection formed by the line of the inner or outer side and the bottom surface of the runner on the cross section of the shaft is the line of the Archimedes spiral or the projection of the center line of the Archimedes runner on the cross section of the runner, or the projection formed by the blade A projection on the cross section of the runner is set for the entire flow path from the inner side of the blade to the outer side of the adjacent blade, as the basis for design and processing.

Figure 3 and Figure 4 are schematic diagrams of the work of the Archimedes runner. The water inlet pipe is connected to the bell mouth seat ring 1, and the water flow is axially injected into the runner, and the water flow changes from the axial direction to the radial direction, and at the same time changes from the axial direction to the radial direction, and at the same time drives the runner to rotate with pressure energy and kinetic energy along the Archimedes channel. The water flow is sprayed in an approximately tangential direction at the tail of the flow channel (that is, at the maximum radius R). Numbers 9 and 10 are respectively the spray direction of the water flow and the rotation direction of the runner. The runner drives the main shaft 11 to rotate.

Fig. 5 is a schematic diagram of the Archimedes screw runner hydroelectric power station. The water inlet of the utility model Archimedes spiral runner 12 is communicated with the reservoir 15 by the water inlet pipe 14 contained in the dam 13 . The runner is connected with the generator 17 through the connecting shaft 16 .

Fig. 6 is a working schematic diagram of the Archimedes screw runner as a Francis turbine. The water flows through the volute 18, the seat ring 19, and radially injects into the runner 21 through the water guide mechanism 20, and the water does work in the Archimedes spiral channel formed by the Archimedes spiral blade 22, and pushes the runner with pressure energy and kinetic energy 21 and drives the main shaft 23 to rotate. The bell mouth ring seat 24 is connected with the draft tube, and the water flows through the bell mouth ring seat and is discharged through the draft tube.

Fig. 7 is a schematic diagram of the formation of the Archimedes spiral.

Fig. 8 is a working schematic diagram of an existing Francis turbine. The water flows through the volute 25 , the seat ring 26 and radially injects into the Francis turbine runner 29 with X-shaped blades 28 through the water guiding mechanism 27 , pushes the runner 29 and drives the main shaft 30 to rotate.

Fig. 9 is a structural schematic diagram of an existing "X-shaped blade". It includes an upper crown edge 31, a lower ring edge 32, a water inlet edge 33, and a water outlet edge 34.

Fig. 10 is a schematic structural diagram of a conventional Francis runner with auxiliary blades. The runner includes main blades 35 and auxiliary blades 36 .

The Archimedes spiral runner of the utility model is applied to the field of hydroelectric power generation. It is actually a kind of energy conversion device; it converts the energy of water flow into rotating mechanical energy to drive a generator to generate electricity. High efficiency, water saving and smooth operation are the goals it pursues. If the hydropower station adopts this runner, then 80% of the flow can be used to generate electricity at full capacity, or 20% more electricity can be generated with the same flow, and the situation of unstable operation in high water head and low flow areas can be greatly improved. All countries are making great efforts to study this subject, and all want to extract this jewel in the crown of hydroelectric power generation.

Water-saving power generation and more power generation will greatly change the proportion of hydropower in energy, and will have an immeasurable impact on the economy, society, environment, and ecology.

Claims (7)

1, Archimedes spiral rotating wheel, comprise water intake and water outlet, be positioned at the blade of runner, it is characterized in that the runner between adjacent blades is the Archimedian screw runner, longshore current road direction has a line that is projected as spiral of Archimedes on the runner cross section in the runner.

2, Archimedes spiral rotating wheel according to claim 1 is characterized in that spiral of Archimedes is the inboard and projection of runner bottom surface intersection on the runner cross section of blade.

3, Archimedes spiral rotating wheel according to claim 1 is characterized in that spiral of Archimedes is the blade outside and the projection of runner bottom surface intersection on the runner cross section.

4, Archimedes spiral rotating wheel according to claim 1 is characterized in that the Archimedes spiral line is the projection of Archimedes's spiral shell runner center line on the runner cross section.

5, Archimedes spiral rotating wheel according to claim 1 is characterized in that linear leaf, short blade are arranged in the blade, and linear leaf and short blade are alternate to be evenly distributed on the runner.

6,, it is characterized in that there is the horn mouth seat ring that cooperates with it the runner water inlet according to the described Archimedes spiral rotating wheel of one of claim 1～4.

7, Archimedes spiral rotating wheel according to claim 5 is characterized in that there is the horn mouth seat ring that cooperates with it the runner water inlet.

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