RU120111U1 - DEVICE FOR COOLING PERMANENTLY FROZEN SOILS - Google Patents

Abstract

1. A device for cooling permafrost soils, made in the form of a tubular body, partially submerged in the ground and partially located above the ground level, containing an inner pipe located coaxially to the body, and in the lower part of the body pipe and the inner pipe are connected by a channel, characterized in that the upper ends the tubular body and the inner pipe are located at the same level, the annular gap between the upper parts of the body and the inner pipe is hermetically sealed, and the space between the body and the inner pipe is connected to the exhaust pipe in the upper part. ! 2. The device according to claim 1, characterized in that the inner and exhaust pipes are made of a material with a low thermal conductivity of the walls. ! 3. The device according to claim 1, characterized in that the diameter of the inner tube is greater than the transverse dimension of the space between the body and the inner tube of the space.

Description

The utility model relates to the field of construction on permafrost soils and relates to the manufacture of devices for accumulating cold at the base of structures.

It is known “Device for accumulating cold at the base of structures” SU 815122 [1], which includes a tubular body partially located in the ground and a jet distribution pipe coaxially located in it. A heating element is located at the top of the jet distribution pipe.

The disadvantages of the known design are the low energy efficiency of operation due to the presence of a heating element, which must be supplied with electricity.

Closest to the claimed technical solution is the device described in "The method of installation in soil of a freezing column" SU 1728365 [2], made in the form of a tubular body, partially immersed in the soil and partially located above the ground level and containing an inner pipe located coaxially to the body, moreover in the lower part, the casing pipe and the inner pipe are connected by a channel.

The known method has increased energy efficiency due to the absence of a heating element.

The disadvantage is the low reliability and low cooling capacity of the device. In this device, the direction of air movement is unstable. If there is wind above the upper end of the inner pipe, a certain discharge of air occurs. As a result, cold air enters the annulus and exits through the inner pipe. In the absence of wind, air in the annulus due to the influx of heat from the surrounding frozen soils is heated and rises through the annulus, and cold air enters the inner pipe. Reverse air flow in the device due to a drop in its speed to zero reduces its cooling ability. In summer, under the influence of wind, warm air is sucked into the annulus and ice forms on the cold walls of the pipes below the seasonal thawing boundary, which inevitably clogs it in the first or subsequent warm periods of the year. In addition, between the oncoming air flows through the steel pipe separating them, intense heat exchange occurs, significantly reducing the cooling efficiency of the soil.

The technical result of the proposed utility model is to increase the cooling ability and reliability of the device.

The technical result is achieved by the fact that the upper ends of the tubular housing and the inner pipe are located at the same level, the annular gap between the upper parts of the housing and the inner pipe is hermetically closed, and the space between the housing and the inner pipe in the upper part is connected to the exhaust pipe.

The inner and exhaust pipes can be made of a material with low thermal conductivity of the walls. The specified implementation improves the efficiency of the device. The implementation of the inner pipe from a material with low thermal conductivity can increase the efficiency of heat transfer, eliminating spurious heat transfer between the incoming and outgoing flows. The implementation of the exhaust pipe from a low-conductive material will increase the efficiency of the hood due to increased traction due to the reduction of spurious heat transfer between the flow inside the exhaust pipe and the surrounding air.

The diameter of the inner pipe may be larger than the transverse dimension of the annulus.

The ratio of the transverse dimensions of the inner pipe and the annulus is determined by calculations.

From the condition of equality of the cross-sectional area of the pipe and the annulus we obtain

where d _{2, in} , d _{1, in} and d _{1, n} - respectively, the inner diameter of the outer pipe, the inner and outer diameters of the inner pipe. The ratio of the transverse dimensions of the channels is

where c is the gap between the inner and outer pipes.

Marking , from formula (2) we find

To assess the ratio of the transverse dimensions of the channels in the device, you can take k = 1,1; then

Thus, the formation of ice in the inner pipe, the diameter of which is more than 5 times larger than the transverse dimension of the annular space, significantly increases the reliability of the device, and the movement of air in one direction and the reduction of heat transfer between the upward flow of air with a downward flow and the outside air increase the cooling capacity of the device .

In FIG. presents a cross section of the proposed device mounted in the well, where:

1 - well;

2 - soil filler annulus;

3 - case;

4 - an internal pipe;

5 - annular gap;

6 - annular space;

7 - exhaust pipe;

8 - border of seasonal thawing of soil;

9 - ice.

The device operates as follows: The proposed device is placed in the well 1 and the space between the body 3 and the well 1 is filled with soil filler of the annulus 2. The upper part of the inner pipe 4 and the upper part of the body 3 form an annular gap 5, which is hermetically closed. Between the inner tube and the body creates an annular space 6, which serves as a channel for the upward flow of air. The inner part of the inner pipe 4 serves as a channel for the downward flow of air. The exhaust pipe 7 creates a stable draft. The seasonal defrost line 8 is located below ground level.

In this device, in summer, ice 9 freezes on the walls of the inner pipe, the diameter of which is several times larger than the transverse dimension of the annular space 6. In winter, ice 9 formed on the walls of the inner pipe is intensively evaporated under the influence of a stream of cold dry air, and the channel is cleared of ice . The inner 4 and exhaust 7 pipes with low thermal conductivity reduce heat transfer between the oncoming air flows and the outside air, which further enhances the cooling ability of the device.

EFFECT: increased cooling ability and increased reliability of the device is achieved by moving air in one direction - from the bottom up for the inner surface of the case, providing highly efficient cooling in winter and the absence of heating in summer due to the peculiarities of seasonal melting and ice freezing.

Industrial application. The proposed utility model can be successfully applied for the production of soil cooling devices, including those combined with bearing piles.

Claims (3)

1. A device for cooling permafrost soils, made in the form of a tubular body, partially immersed in the soil and partially located above the ground level, containing an inner pipe located coaxially to the body, and in the lower part of the body pipe and the inner pipe are connected by a channel, characterized in that the upper ends the tubular casing and the inner pipe are flush, the annular gap between the upper parts of the casing and the inner pipe is hermetically closed, and the space between the casing and the inner pipe minutes in the upper part is connected to the exhaust pipe. 2. The device according to claim 1, characterized in that the inner and exhaust pipes are made of a material with low thermal conductivity of the walls. 3. The device according to claim 1, characterized in that the diameter of the inner pipe is larger than the transverse dimension of the space between the housing and the inner pipe of the space.