CN108169281B

CN108169281B - Vent pipe aperture ratio control test device and method

Info

Publication number: CN108169281B
Application number: CN201810042269.4A
Authority: CN
Inventors: 孙斌祥; 杨丽君; 张昌扬; 潘述平; 詹培敏
Original assignee: Shaoxing University Yuanpei College
Current assignee: Shaoxing University Yuanpei College
Priority date: 2018-01-17
Filing date: 2018-01-17
Publication date: 2023-08-15
Anticipated expiration: 2038-01-17
Also published as: CN108169281A

Abstract

The invention mainly relates to a vent pipe aperture ratio control test device which comprises a first vent pipe with a hollow structure, wherein a plurality of first vent holes are formed in the first vent pipe, a second vent pipe with a second vent hole is arranged in the first vent pipe, and the second vent pipe is provided with a second vent hole with a quantity corresponding to the first vent hole. The design has few variables and convenient experiment in the experimental process, can prevent the generation of redundant variables, and ensures the high efficiency of the experimental process and the accuracy of the experimental result.

Description

Vent pipe aperture ratio control test device and method

Technical Field

The invention relates to a vent pipe opening ratio control test device and a vent pipe opening ratio control test method, in particular to a vent pipe opening ratio control test device and a vent pipe opening ratio control test method.

Background

The permeable wall ventilation pipe roadbed is a roadbed form in a frozen soil roadbed structure. The roadbed structure is an improved method for opening holes in the pipe wall of a ventilation pipe buried in a roadbed filling material on the basis of a traditional ventilation pipe roadbed structure. The principle of the permeable wall ventilation pipe for cooling the soil body is as follows: firstly, heat in the soil body is taken away by convective heat exchange between the cold air flow in the ventilation pipe and the pipe wall. Secondly, the moisture in the soil body close to the ventilation pipe is evaporated through the pipe wall openings, and the soil body is cooled through evaporation heat dissipation in the evaporation process. The aperture ratio of the permeable wall ventilation pipe is a key factor influencing the cooling effect of the permeable wall ventilation pipe roadbed. By adopting the traditional test method, a plurality of vent pipe samples with different opening ratios are required to be manufactured and buried in a sample box. In this process, a number of variables are caused, such as the degree of compaction and the water content of the filler used in each test, to change. In addition, the process of replacing ventilation pipes with different opening ratios is time-consuming. These problems have a great impact on the accuracy and efficiency of the test.

Disclosure of Invention

In order to solve the problems, the invention provides a vent pipe aperture ratio control test device and a vent pipe aperture ratio control test method.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the ventilation pipe aperture ratio control test device comprises a first ventilation pipe with a hollow structure, wherein a plurality of first ventilation holes are formed in the first ventilation pipe, a second ventilation pipe with a plurality of second ventilation holes are formed in the first ventilation pipe, and the second ventilation pipe is provided with a plurality of second ventilation holes corresponding to the first ventilation holes.

The first through-wall ventilation pipe is a plastic pipe with the diameter of 5-12 cm and the length of 0.8-1.5 m.

The first ventilation pipe is uniformly provided with a plurality of first ventilation holes with the distance of 2-4 cm, and the diameter of the first ventilation holes is 0.5-1.5 cm.

The second permeable wall ventilation pipe is a plastic hollow pipe, the outer diameter of the second permeable wall ventilation pipe is 0.1-0.3 cm smaller than the inner diameter of the first permeable wall ventilation pipe, the second permeable wall ventilation pipe can freely rotate in the first permeable wall ventilation pipe, and the second permeable wall ventilation pipe is the same as the first permeable wall ventilation pipe in length.

And the vent hole II on the vent pipe II corresponds to the vent hole I in position and has the same aperture.

The lower end of the through-wall ventilation pipe II is provided with a bulge.

A vent pipe aperture ratio control test method comprises the following specific steps:

1. filling sandy soil or broken stone filler into the sample box;

2. inserting a second permeable wall ventilation pipe into the first permeable wall ventilation pipe;

3. embedding the assembled first permeable wall ventilation pipe and the assembled second permeable wall ventilation pipe into the filler;

4. arranging a temperature sensor in the sample box according to test requirements;

5. placing the sample box into a temperature control chamber;

6. the second permeable wall ventilation pipe is rotated by the protrusion by a required angle, and one part of the ventilation hole on the first permeable wall ventilation pipe is covered by the second permeable wall ventilation pipe, so that the opening ratio of the first permeable wall ventilation pipe is controlled;

7. test data and conclusions are drawn by observing the temperature sensor to detect changes in temperature.

The invention has the following beneficial effects:

1. the ventilation pipe aperture ratio control test device comprises a first ventilation pipe with a hollow structure, wherein a plurality of first ventilation holes are formed in the first ventilation pipe, a second ventilation pipe with a plurality of second ventilation holes are formed in the first ventilation pipe, and the second ventilation pipe is provided with a plurality of second ventilation holes corresponding to the first ventilation holes. The design has few variables and convenient experiment in the experimental process, can prevent the generation of redundant variables, and ensures the high efficiency of the experimental process and the accuracy of the experimental result.

2. The bulge is arranged at the lower end of the second permeable wall ventilation pipe, so that an experimenter can conveniently adjust the rotation angle of the second permeable wall ventilation pipe.

Drawings

FIG. 1 is a perspective view of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a front view of the experimental state of the invention;

FIG. 4 is a perspective view of a sample case of the present invention;

FIG. 5 is a schematic diagram of a new open area calculation according to the present invention.

Reference numerals in the drawings: 1. a first ventilation pipe with a penetrating wall; 2. a second ventilation pipe with a penetrating wall; 21. a protrusion; 3. a first ventilation hole; 4. a vent II; 5. sample box.

Detailed Description

The invention will be explained in more detail by the following embodiments:

as shown in fig. 1 and 2, the invention provides a vent hole ratio control test device, which comprises a first vent pipe 1, wherein the first vent pipe 1 is of a hollow structure, a plurality of first vent holes 3 are formed in the first vent pipe 1, a second vent pipe 2 is arranged in the first vent pipe 1, and a plurality of second vent holes 4 corresponding to the first vent holes 3 are formed in the second vent pipe 2. The design has few variables and convenient experiment in the experimental process, can prevent the generation of redundant variables, and ensures the high efficiency of the experimental process and the accuracy of the experimental result.

The first ventilation pipe 1 with a permeable wall is a plastic pipe with a diameter of 5-12 cm and a length of 0.8-1.5 m.

A plurality of vent holes I3 with the distance of 2-4 cm are uniformly arranged on the vent pipe I1, and the diameter of the vent hole I3 is 0.5-1.5 cm.

The second permeable wall ventilation pipe 2 is a plastic hollow pipe, the outer diameter of the second permeable wall ventilation pipe 2 is 0.1-0.3 cm smaller than the inner diameter of the first permeable wall ventilation pipe 1, the second permeable wall ventilation pipe 2 can freely rotate in the first permeable wall ventilation pipe 1, and the second permeable wall ventilation pipe 2 and the first permeable wall ventilation pipe 1 are the same in length.

And a vent hole II 4 on the vent pipe II 2 with the penetrating wall corresponds to the vent hole I3 in position and has the same aperture.

The lower end of the second ventilation pipe 2 is provided with a bulge 21, so that the experimenter can conveniently adjust the rotation angle of the second ventilation pipe 2.

As described above, referring to fig. 3 and 4, a test method for controlling the aperture ratio of a vent pipe comprises the following specific steps:

embodiment one:

1. filling sand or broken stone filler in the sample box 5;

2. inserting a second permeable wall ventilating pipe 2 into the first permeable wall ventilating pipe 1;

3. embedding the assembled first ventilation pipe 1 and the assembled second ventilation pipe 2 into the filler;

4. a temperature sensor is arranged in the sample box 5 according to the test requirement;

5. placing the sample box 5 into a temperature control chamber;

6. the through-wall ventilation pipe II 2 is rotated by a required angle through the bulge 21, and the part of the ventilation hole I3 on the through-wall ventilation pipe I1 is shielded by the through-wall ventilation pipe II 2, so that the opening ratio of the through-wall ventilation pipe I1 is controlled;

Embodiment two:

the second ventilation pipe 2 with the permeable wall is placed in the interior and rotated by an angle alpha, and the calculation formula of the aperture ratio is shown as a formula 1:

(1)

In the formula 1, a is a single open area, k is the number of open holes, and A is the total area of the pipe wall; r is the radius of an opening, k is the number of the opening, h is the length of the ventilation pipe, and D is the diameter of the outer wall of the ventilation pipe used for the test;

the new open area formula is shown in figure 2:

(2)

In the formula 2, d is the width of the intersection part of the two openings, r is the same as r in the formula 1, and in the new opening area calculation schematic diagram shown in fig. 5, 1 is the opening of the vent pipe used for the test, 2 is the opening of the vent pipe put in, 3 is the edge of the outer wall of the vent pipe, and L is the distance between the center of the opening and the edge of the outer wall of the vent pipe; alpha is the angle through which the ventilation pipe is placed inside;

the width d of the intersection of the two openings is shown in figure 3:

(3)

Embodiment III:

note that: the average temperature in a temperature control box used in the test is between-0.5 ℃ and 1.0 ℃, the temperature amplitude is 15.53 ℃, the air temperature fluctuation period of the test box is 72 hours, and the test is carried out for 5 periods; the temperature values in the table are average values of temperatures measured for a plurality of cooling periods (1/4 time point of each cooling period).

Summary of effects: as the opening ratio is continuously increased, the cooling effect of the permeable wall ventilation pipe roadbed is more obvious, and the concrete effect of the permeable wall ventilation pipe on the roadbed cooling can be effectively researched by the test method.

Claims

1. The vent pipe opening ratio control test method is characterized by comprising the following specific steps:

(1) Filling sand or broken stone filler in the sample box;

(2) Inserting the second permeable wall ventilating pipe into the first permeable wall ventilating pipe;

the first ventilation pipe with the permeable wall is of a hollow structure, a plurality of first ventilation holes are formed in the first ventilation pipe with the permeable wall, and a second ventilation hole with the number corresponding to that of the first ventilation holes is formed in the second ventilation pipe with the permeable wall;

the first ventilation pipe with the wall is a plastic pipe with the diameter of 5-12 cm and the length of 0.8-1.5 m, and a plurality of first ventilation holes with the distance of 2-4 cm are uniformly arranged on the first ventilation pipe with the diameter of 0.5-1.5 cm;

the second permeable wall ventilation pipe is a plastic hollow pipe, the outer diameter of the second permeable wall ventilation pipe is 0.1-0.3 cm smaller than the inner diameter of the first permeable wall ventilation pipe, the second permeable wall ventilation pipe can freely rotate in the first permeable wall ventilation pipe, the second permeable wall ventilation pipe is the same as the first permeable wall ventilation pipe in length, the second ventilation hole on the second permeable wall ventilation pipe corresponds to the first ventilation hole in position and has the same aperture, and a bulge is arranged at the lower end of the second permeable wall ventilation pipe;

(3) Embedding the assembled first ventilation pipe and the assembled second ventilation pipe into the filler;

(4) Arranging a temperature sensor in the sample box according to the test requirement;

(5) Placing the sample box into a temperature control chamber;

(6) The second through-wall ventilation pipe is rotated by a required angle through the bulge, and one part of the ventilation hole on the first through-wall ventilation pipe is covered by the second through-wall ventilation pipe, so that the opening ratio of the first through-wall ventilation pipe is controlled;

(7) Test data and conclusions are drawn by observing the temperature sensor to detect changes in temperature.