RU2244868C2 - Pressure vessel - Google Patents

Abstract

FIELD: storing or distributing gases or liquids.

SUBSTANCE: pressure vessel has cylindrical shell made of spiral and ring layers which are made of a fiber composite material and bottoms with flanges made of spiral layers and set in openings. The thickness of the cylindrical shell uniformly decreases along the length in the direction to the bottom with greater opening due to the decrease of the thickness of the ring layers.

EFFECT: reduced weight and cost of vessels.

3 dwg

Description

The invention relates to the field of gas storage and can be used in pressure cylinders made of composite materials by winding.

A known pressure cylinder (RF patent No. 1744358, MKI F 17 C 1/06, 1992) containing a cylindrical shell and bottoms made as a whole by the method of spiral winding. The thickness of the cylindrical shell of the container is made variable, in accordance with the stated formula, with laying when winding in certain places of napkins made of composite material.

The disadvantage of this design is the use in its manufacture of manual styling napkins.

A known construction of a composite cylinder for storing compressed gas (RF patent No. 2061927, MKI F 17 C 1/16, 1996 - the closest analogue), containing a cylindrical power shell made of spiral and annular layers of fibrous composite material, and in areas adjacent to the bottoms between the spiral layers of the power shell are additional annular layers.

This increases the reliability of fixing the embedded elements in the pole holes of the bottoms, however, the comparative diagrams shown show a slight increase in stresses in the cylindrical part of the power shell. In addition, significantly increases the mass of the structure.

In the case of creating a pressure cylinder with pole holes of different diameters, the winding angles of the reinforcing fibers of the spiral layers in the zones adjacent to the bottoms are different for reasons of formation of the bottoms. In this case, when calculating the thickness of the cylindrical shell, the different loading of the annular and spiral layers in the zones adjacent to the bottoms is not taken into account. This leads to a heavier structure.

The objective of the proposed technical solution is to reduce the weight and cost of the material of the pressure cylinder with pole holes of different diameters by taking into account the peculiarities of the loading of the end zones of its cylindrical shell and ensuring equal structural strength.

This problem is solved due to the fact that in the pressure cylinder containing a cylindrical shell made of spiral and annular layers of fibrous composite material and formed by spiral layers of the bottom with flanges installed in the pole holes, the thickness of the cylindrical shell along its length is variable, the thickness of the cylindrical shell decreases along its length in the direction of the bottom with a large pole hole by reducing the thickness of the annular layers.

The thickness of the annular layers from the side of the smaller and larger pole holes is made in accordance with the ratio:

where h ₁ is the thickness of the annular layers from the side of the smaller pole hole;

h ₂ - the thickness of the annular layers from the side of the larger pole hole;

where α ₁ is the angle of winding of the spiral layers from the side of the smaller pole hole;

R ₁ is the radius of the smaller pole hole;

R _C is the radius of the cylindrical shell;

where α ₂ is the angle of winding of the spiral layers from the side of the larger pole hole;

R ₂ is the radius of the larger pole hole.

Ring and spiral layers should be understood as layers with a corresponding arrangement of the reinforcing fibers of the composite material during winding. The thickness of the annular or spiral layers should be understood as the total thickness of the layers with the corresponding arrangement of fibers in the thickness of the shell. Moreover, the sequence of arrangement of layers with an annular and spiral arrangement of reinforcing fibers can be different. The thickness of the spiral layers does not change along the length of the cylindrical shell. The change in the angle of winding of the spiral layers along the length of the shell and the change in the thickness of the annular layers along the length of the shell are uniform.

The presence of one of the pole holes of a larger radius and the execution of the spiral winding angle along the length of the cylindrical shell increasing in the direction of this hole lead to the fact that these spiral layers partially absorb the radial load. In this regard, to ensure alignment of the loading of the cylindrical shell along its length, the thickness of its annular layers is made decreasing in the direction of the bottom with a large flange in comparison with the design thickness obtained without taking into account different radius of the pole holes. This achieves a decrease in the mass of the pressure cylinder while ensuring equal structural strength.

The above ratios of the thicknesses of the annular layers from the side of the smaller and from the side of the larger holes of the flanges in the bottoms of the pressure cylinder are calculated by taking into account the condition of equal strength design with the corresponding ratio of the thicknesses of the annular and spiral layers forming the wall of the cylindrical shell.

The pressure cylinder is shown in the drawings:

figure 1 - General view of the pressure tank;

figure 2 is a schematic diagram of the thicknesses of the spiral and annular layers along the length of the cylindrical shell;

figure 3 - place a of figure 1.

The pressure cylinder with pole openings of different sizes contains a cylindrical power shell 1 with a radius R _c , a bottom 2 with a pole bore with a radius R ₁ and a bottom 3 with a pole bore R ₂ in which flanges 4 and 5 are installed. Shell 1 and bottoms 2, 3 made as a whole by the method of winding: the shell 1 is made of spiral and annular layers of fibrous composite material, and the bottoms 2, 3 are formed by spiral layers of the composite material. The winding angle of the spiral layers (Fig. 1) increases from α ₁ from the bottom 2 with a smaller pole hole to α ₂ from the bottom with a large pole hole. The thickness H of the cylindrical shell 1 (figure 2) is the sum of the total thickness h _{from the} spiral layers and the total thickness of the annular layers, decreasing along the length of the cylindrical shell 1 in the direction of the bottom 3 with a large pole hole from h ₁ to h ₂ .

As a composite material for a pressure balloon, any of the known reinforcing materials can be used: glass, basalt, carbon, organic and other fibers.

Example.

Fiberglass pressure tank.

Cylinder length: 3500 mm

The radius of the cylinder: R _C = 450 mm

The radius of the pole hole R ₁ = 175 mm.

The radius of the pole hole is R ₂ = 275 mm.

Since the cylinder is designed for possible use in a helicopter with a gas fuel system, the indicated weight savings are significant.

Claims (1)

A pressure cylinder containing a cylindrical shell made of spiral and annular layers of fibrous composite material and formed by spiral layers of the bottom with flanges installed in the pole holes, the thickness of the cylindrical shell along its length being variable, characterized in that the thickness of the cylindrical shell uniformly decreases along its length in the direction of the bottom with a large pole hole by reducing the thickness of the annular layers.

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