SU1719612A1 - Device for thermal drilling in ice - Google Patents

Abstract

The invention relates to mining and m. used in drilling-melting wells in the ice. The purpose of the invention is to increase the drilling efficiency due to the redistribution of external and internal heat fluxes. The body consists of an inner ring 1 and an outer shell 2. Between them, a heat pipe 3 of a semi-toroidal shape with ferromagnetic shells 4 in its cavity is strengthened. Inductor 5 creates a field that shuts off over the shells 4. In this case, the last heat is radiated to the ice mass. The maximum heat energy (up to 80%) is concentrated on the bottom, which increases the efficiency of the device. 1 il.

Description

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The proposed device relates to a technique used in the mining industry, in particular, to devices for drilling wells in ice and frozen soils, and can be used for core sampling from soils and ice covers.

A device for electrothermal drilling of holes in ice is known, which includes a cylindrical hollow body, in which body the turns of the electric heating element 1 are located. body parts.

The closest to the proposed device according to the technical essence and achievable. The result is a device for electrothermal drilling of wells in ice, including a hollow cylindrical body-magnetic core, in the body of which the coils of the inductor are located along the perimeter, the winding plane of which is perpendicular to the end face in longitudinal section body-magnetic. A disadvantage of the electrothermal well drilling device in ice is that, due to the absence of directional energy concentration at the bottomhole, the heat transfer efficiency decreases, the drilling energy intensity increases due to the melting of ice volumes near the borehole walls and, as a result, the drilling efficiency decreases.

The purpose of the invention is to increase the drilling efficiency by increasing the power realized at the bottomhole.

. The goal is achieved by the fact that between the inner ring of the housing and the shell there is a rigidly fixed heat pipe of one and a half shape, having an internal cavity with ferromagnetic shell, and the height of the open outer surface of the heat pipe is 2-4 times higher than the height of the open inside surface of the heat pipe.

The drawing shows schematically a device for electric drilling in ice, longitudinal section.

The device consists of a detachable hollow cylindrical body comprising an inner ring 1 and an outer shell 2 made of a low thermal conductivity material. A copper heat energy concentrator — a heat line 3 — is located inside the case, the inner cavity of which is covered by ferrous magnetic shells 4 adjacent to a heat pipe. Coils of copper conductors are located in the cavity of the heat pipe — inductor 5 in insulation 6.

The device for electrothermal drilling of wells in ice works as follows,

After being installed on ice and connected to a high-frequency power source (5.5-4 kHz), inductor 5 carries a current, which creates a magnetic field closing through the ferromagnetic shells 4. It induces in them. EMF, under the action of which current flows through the shells, releases thermal energy. Since the shells 4 are tightly attached to the heat pipe 3

5 (for example, a riveted joint), the temperature stress during the transfer of the required amount of heat from the shells 4 to the heat pipe 3 is insignificant.

Compared with the traditional method of heat transfer, which consists in the fact that the heater, through which the current flows from an external source, has electrical insulation, and therefore has a high thermal resistance during heat transfer.

5B of the proposed device, the extracted heat energy is concentrated (80% of the total power of the device) at the end, i.e. in the area of contact with the bottom, which significantly increases the rate of drilling and melting of wells.

The housing of the device, consisting of the inner ring 1 and the outer shell 2, is made of steel, i.e. from material less heat-conducting than copper. In this way,

5 reduced heat transfer through the side surfaces.

The magnitude of the body of the heat pipe from under the shielding parts of the body is adjusted depending on the size of the development

0 wells and the required core diameter.

The use of the proposed device allows a significant increase in the power sold at the bottomhole, due to the fact that the heater transmits heat

5 energy directly to the heat pipe rather than through the insulation (electric or heat}, as with the traditional method of heating. The temperature of all parts of the device does not exceed 100 ° C with noticeably large transmitted

0 power x. This ensures drilling efficiency by increasing power and increasing the reliability of individual elements and their durability.

In addition, the proposed device

5 allows the wellbore diameters of both the well to be maintained during the drilling process by controlling the heat flow transmitted radially to the well and the core. This allows trouble-free drilling in the ice with the required

the gap between the projectile and the well at the maximum possible diameters of the well and core.

When testing the proposed device drilled 200 m wells. The high reliability of the device makes it possible to efficiently drill and melt glaciers in various modes, both dry and non-freeze-filled wells. Drilling-melting kern contains many-sided information about the changing natural conditions of the Earth and is of great interest to a whole range of natural sciences, such as glycologists, geophysics, microbiologists, and others. Formula of electrothermal drilling-drilling in ice containing

five

a stinging body, consisting of an inner ring and an outer shell of a material with low thermal conductivity, and an inductor, the turns of which are wound in a plane that is perpendicular to the end of the case, characterized in that, in order to increase drilling efficiency internal heat fluxes, it is provided with a one-and-a-half heat wave with an internal cavity and ferromagnetic shells placed in the latter, with a heat line fixed between the ring and the shell to ensure that the height of the the outer surface of the heat pipe above the height of its open inner surface 2-4 times.

Claims (1)

Claim A device for electrothermal drilling and melting of wells in ice, comprising a casing consisting of an inner ring and an outer shell of material with low thermal conductivity, and an inductor whose coils are wound in a plane perpendicular to the end of the casing, characterized in that, for the purpose of to increase drilling efficiency by redistributing the external and internal heat fluxes, it is equipped with a sesqui-shaped heat pipe with an internal cavity and ferromagnetic shells located in the latter, moreover, eplen between the ring and the shell ensuring the height exceeding the exposed outer surface of the heat line above the height of the inner surface of its open 2-4 times.