SU1502953A2 - Heat exchange element - Google Patents

Abstract

The invention relates to heat exchange apparatus and intensifies heat exchange when used in shipboard hot water boilers. The heat exchange element comprises a pipe 1 with a sectional swirler inside in the form of a wire helix 2. In the adjacent sections 3 and 4, the helix is made with a different helix angle. Section 3 of helix 2 is attached to pipe 1 and the angle of its helix is determined by the physical properties of the material of the helix, the diameter of the helix wire, the diameter of its helix and the length of section 3. When the internal combustion engines operate, their mechanical vibrations are transmitted hot water boiler. Section 3 of helix 2, having a helix angle, has a natural frequency that coincides with the frequency of oscillation of the gas discharge system. As a result of the coincidence of the frequencies of natural and forced oscillations, section 3 experiences the appearance of resonance and begins to make oscillatory movements along pipe 1. 2 Il.

Description

150

The invention relates to heat exchange apparatus and can be used in shipboard water heating boilers, and is an improvement of the known heat exchange element according to the author. USSR № 66А018.

The aim of the invention is to intensify heat transfer when used in shipboard hot water boilers.

FIG. 1 shows schematically the proposed heat exchange element; in fig. 2 - scan coil attached section of the spiral.

The heat exchange element contains a pipe 1 with a sectional swirler inside in the form of a wire helix 2. In the adjacent sections 3 and 4, the helix is made with a different helix angle. Section 3 of helix 2 is attached to pipe 1 and the angle of its helix is determined from the expression

about arccos

pp2 12. 1Q2

G2-d2

(lr

).

de p D 1 G d

-the density of the material of the spiral, kg / m;

- diameter of helix helix, m;

- length of the spiral section with fastening, m)

modulus of shear of the material of the spiral. Pa;

- diameter of a wire of a spiral, M {

During operation of the shipboard internal combustion engines 40, their mechanical vibrations are transmitted to the gas-exhaust system, which is part of

pre-heating boiler. Section 3 of helix 2, having a helix angle defined by the proposed method, has a natural frequency that coincides with the frequency of oscillation of the gas discharge system. As a result of the coincidence of the frequencies of natural and exhausted oscillations, section 3 experiences a resonance and begins to oscillate along pipe 1, simultaneously driving the adjacent section 4. The natural frequency of section 3 is 10 s. The coolant, the flow through pipe 1, is turbulized and heat transfer is generally intensified.

20 f

formula of invention

five

0

Heat exchanger element auth.St. No. 664018, characterized in that, in order to intensify heat exchange when used in shipboard hot water boilers, the end of the first section of the helix is attached to the pipe and the angle of its helix is determined from the fusion

d arccos

p D2.12. 02

G-d2 J

(JP -D -l 1 /, / (

five

where p is the density of the spiral material

whether. kg / m3

D

0

1 C d li, kg / m,

helix diameter of the helix, m;

the length of the helix section, m, the shear modulus of the helix material. Pa; spiral wire diameter, m,

Claims (1)

Claim Heat exchanger element No. 664018, characterized in that, in order to intensify heat transfer when used in ship boilers, the end of the first spiral section in the direction of flow is attached to the pipe and the angle of its helix is determined from the expression PD ² Ί ² · 10 ² Gd ² o /, = arcco where p is the density of the spiral material, kg / m ³ ; D is the diameter of the helix of the spiral, m; 1 - the length of the attached spiral section, m) G is the shear modulus of the spiral material, Pa; d is the diameter of the wire of the spiral, m, FIG. 2