RU2556452C1 - Downcomer - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: downcomer contains input and main sections with walls limited by surfaces of rotation. Walls of input and main sections are provided with internal superhydrophobic film coating. Wall of the main section is made in form of connected power mesh and internal superhydrophobic film with system of microholes. Axes of the microholes make with the pipe axis directed from input section to output of the main section the angle from 90 to 160 degrees.

EFFECT: reduced lifting force.

2 cl, 3 dwg

Description

The invention relates to the field of renewable energy and fresh water and hydraulic piping systems.

In the works of Fedyaevsky K.K. Decrease in friction resistance by changing physical constants on the wall. Reports of the Academy of Sciences of the USSR, 9-10, 1943 and Kornilov V.I. Using micro-air blowing through a porous wall to reduce friction on a flat plate. Bulletin of the Novosibirsk University. T. 5, no. 3, 2010. A method for reducing friction (by 45-47%) on a solid surface by blowing gas into the boundary layer is described. This very effective way to reduce hydraulic friction was used in the record high-speed domestic torpedoes of the Shkval type (O. Kaptsov “Is there a torpedo more dangerous than the Shkval? Military Review, 06/20/2013). However, the gas inlet from the head of the fluid-streamlined body can provide a gas film at a relatively small distance from the gas inlet, incomparably shorter than the length of the pipelines. In addition, high energy costs are required to maintain the gas film, and the hydraulic resistance increases sharply when a part of the solid surface accidentally leaves the gas film during torpedo maneuvers.

A well-known technical solution, the closest to the one under consideration, is the patent RU 2073129 "Means for reducing the friction resistance of bodies in a liquid medium, the device for its implementation", IPC F15D 1/06, publ. 04/27/1993, ed. Denisov E.P., Grigoryev V.Yu., Doroshchenko A.V. and others. In it, to reduce hydraulic resistance, a hydrophobic coating is applied to the inner surface of the pipe. However, the decrease in hydraulic resistance is significantly less than in the previous case.

The objective of the present invention is to significantly reduce hydraulic friction in the down pipes, allowing large flows of fluid to pass through small flow sections with minimal energy loss, as well as maintaining low hydraulic friction during random pipe vibrations. This allows in the downpipes of renewable energy and fresh water from the clouds (patent RU 2407914 C1 "Method and device for the renewable production of electricity and clean water", IPC F03B 13/00, published on 12/27/2010, auth. Baybikov AS and patent RU 2500854 C1 “AERO HPP”, IPC E02B 9/00, F03B 13/00. Published on December 10, 2013, authored by Kazantsev AN), connecting the air and ground parts, use pipes with minimum outer and respectively passage sections what achieves the minimum wind aerodynamic drag and the weight of water in the pipe with minimal hydraulic losses. This reduces the necessary lifting force and the volume of supporting balloons, as well as the load in the tethered cables.

This is achieved by performing the main pipe section of two layers: in the form of a connected power grid and an internal continuous superhydrophobic film penetrated by a system of microholes, their axes being with the pipe axis directed from the input section to the output of the main section, an angle from 90 to 160 degrees, or a continuous wall with an internal superhydrophobic coating with a similar system of through-holes.

In FIG. 1 and 2 show the device of the lowering pipe.

The vertical lowering pipe (see Fig. 1) includes an initial non-perforated section 1 bounded by surfaces of revolution with an inner superhydrophobic coating 2. The main section, which is bounded by similar surfaces (in particular, cylindrical), is attached to it and continues to the wall, the wall of which is made of a power grid fastened together 3 and the inner superhydrophobic film 4. The through perforation of the superhydrophobic film in the main section, as shown in FIG. 2, is made in the form of a dense grid of microholes 5. The angle between the axes 6 of the microholes directed from the inside of the pipe and the axis 7 of the pipe, which coincides with the direction from the input section to the output of the main one, is in the range from 90 to 160 degrees. The main section 3 can also be made in the form of a solid continuous pipe with an internal hydrophobic coating 4. Perforation in the main section in this case, as shown in FIG. 3, is made in the form of a dense mesh of through-holes with axes 6.

The pipe is attached to the balloon holding cable 8 with a mesh clamp 9.

The water entering the initial section 1 of the vertical lowering pipe is accelerated by gravity to a speed level that does not cause significant hydraulic losses, taking into account a decrease in hydraulic friction due to super-hydrophobic coating 2. Accordingly, an increase in the pipe cross-section decreases.

Next, the water enters the 4 main perforated area. As in an ejector (see http://en.wikipedia.org/wiki/ejector), the pressure in the water jet is lower than in the surrounding air, penetrating through the through-holes 5 in the film or in the continuous wall of the pipe to the flowing water. This air creates a gas layer between the liquid and the wall, which reduces friction losses. As in ejectors, this is facilitated by blowing gas in the direction of flow through the microholes 5, which are oblique with respect to the wall. This is made possible by using the recently developed technology for manufacturing track membranes on ion accelerators, which, penetrating into solid material, change the structure of the material along the ion path, creating straight or subsequently etched microchannels (Reutov V.F., Dmitriev S.N. Ion-track nanotechnology. Russian Chemical Journal, vol. XLVI, 5, 2002). This technology provides high uniformity of the location and orientation of the microholes. In accordance with increasing speed, the bore of the pipe continues to decrease. Due to the direct conversion of the energy received by the stream into speed, the resulting slight pressure drop between the atmosphere and the stream is perceived by the force element: a grid or a solid wall. Increasing the stability of the pipe contributes to the super-hydrophobic film or coating 4, which repels water molecules and air molecules penetrate into the gap between the flow and the wall. This preserves the gas film even in case of accidental pipe movements with gusts of wind that can affect the long downpipe as part of a plant for renewable energy and fresh water production.

This effect, as well as the forceful effect of the jet on the obstacle, do not allow the collapse of the pipe from external pressure. Aerodynamic and power loads acting on the tube are absorbed by the tethered cable 7 of the aerostat, rigidly attaching the tube using a mesh clamp 8.

A specific implementation of the invention can be illustrated by the example of a drain pipe of a renewable energy and water source, the main section of which has a length of 3000 m, flowing 350 cubic meters. m / hour of water. With a permissible (according to energy loss) input speed of 2 m / s, the input inner diameter of the main section is 250 mm. In accordance with the acceleration of the flow under the action of gravity, the diameter of the pipe changes approximately inversely with the root of the fourth degree from the inlet. At the outlet, the inner diameter of the pipe is 22.5 mm. In the inner film of hydrophobic polyethylenetetrafthalate (according to the aforementioned patent RU 2073129), a network of through micro-holes with a diameter of 5 μm is made using ion-track technology (see above). The axes of the holes make an obtuse angle with the direction of flow, which provides an ejector effect of air leaks from the surrounding atmosphere. Power loads are absorbed by an external power grid of polyester threads attached to the film, from which standard aerostats aerostats are made.

In the case of a significant increase in the power of accelerators used in ion-track technology, it becomes possible to make micro-holes in solid materials of large thickness and through perforation in the solid walls of the pipe together with an internal super-hydrophobic coating. Since the pressure drop in the water stream and in the surrounding atmosphere is insignificant, the pipe wall thickness may be minimal.

The lowering tube is attached to the aerostat's tethered cable by net clamps made of polyester threads, which slightly impede the access of air, allowing the aerodynamic wind and power loads of the pipe to be transferred to the rope. This design provides an inner diameter of the pipe to a height of 2 km less than 30 mm. Thus, the minimum aerodynamic drag in the most dense layers of the atmosphere and the weight of the water in the pipe are ensured.

The technical result of the proposed device is to reduce energy losses at high speeds of water, reducing the diameter and cost of the down pipe, external aerodynamic drag and weight of the water in the pipe. This allows you to significantly reduce the necessary lifting force and the cost of balloons holding the lowering tube, as well as the diameter and cost of tethered cables.

Of course, the proposed design solution for the main section can be used to reduce hydraulic friction in long high-speed pipelines of stationary low-pressure hydraulic systems, to reduce their weight and cost.

Claims (2)

1. The downcomer of the installation for renewable energy and fresh water production, containing the inlet and main sections with walls bounded by surfaces of revolution, with an internal superhydrophobic film coating, characterized in that the wall of the main section is made in the form of a connected power grid and an internal superhydrophobic film penetrated by a system of microholes, and the axis of the holes are with the axis of the pipe directed from the input section to the output of the main section, the angle is from 90 to 160 degrees. 2. A support pipe according to claim 1, characterized in that the solid wall of the main section, together with the inner superhydrophobic coating, is penetrated by a system of through micro-holes.

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