RU2597339C1 - Method of measuring soil temperature - Google Patents

Abstract

FIELD: thermometry.

SUBSTANCE: invention relates to thermometry, namely to a field determination of soils temperatures, where it is required to obtain specific data on the temperature of frozen, freezing and melting soils. Method of measuring soil temperature with the help of a measuring string lowered into the thermometric well. Herewith the casing pipe of the thermometric well represents a tube made from a material with relatively low heat conductivity coefficient (for example, polypropylene) with parts from a material with relatively high heat conductivity coefficient (for example, steel bushings), while the measuring string represents a tube having an outer diameter equal to the inner diameter of the casing pipe and similar in design, in which to metal parts thermocouples are attached for measuring temperature.

EFFECT: technical result is higher accuracy of measurements, elimination of air convection in the thermometric well during the measurement.

1 cl, 2 dwg

Description

The method relates to thermometry, namely to field determination of soil temperature, where it is required to obtain specific data on the temperature of frozen, freezing and thawing soils.

A known method in the form of a device for researching wells with a gradient thermometer (Pozin LZ Well research with a gradient thermometer. Exploration and field geophysics. - M., Gostoptekhizdat, 1969). The device contains two identical series-connected and placed along the axis of the well at a given distance thermosensitive resistors, the first and second.

The disadvantage of this method is the presence of balancing resistors that upset the balance with significant changes in temperature, and registration of only one component of the temperature field - along the axis of the well.

There is a method in the form of a device for thermal logging of wells, containing three identical heat-sensitive sensors located along the axis of the well at a given distance to measure the second temperature difference, the first, second and third (Patent No. 2314416 "Device for thermal logging of wells").

The disadvantages of this method is the narrow scope, low measurement accuracy, redundancy of equipment, the use of indirect methods of measuring one dependence on another.

A known method in the form of a device for monitoring temperatures in an extended object, containing a thermal suspension consisting of temperature sensors in series located in a protective casing of a small diameter, a control microcontroller, a signal converter, non-volatile memory, a real-time clock, a solver, a block for setting initial parameters , built-in power supply, and data transmission interface, as well as equipped with a seal designed to prevent ingress ambient air into the well during the measurement. The casing is made in the form of a removable thick-walled polymer sheath of a self-supporting cable (Patent No. 75692 "Device for monitoring temperatures in an extended object").

The disadvantage of this method is the long time of the thermal reaction due to the presence of a thick thick-walled polymer shell in which the thermal suspension is located, as well as the low tightness of the thermal suspension in the absence of a thick-walled polymer shell, which leads to a failure of the device in conditions of increased dust and moisture.

The closest technical solution is a method in the form of temperature measurement using a thermocut, which is lowered into a thermometric well and contains temperature sensors in series, interconnected by a flexible cable that provides electrical connection to temperature sensors, a connector for connecting to a reader, storage, processing and display device data, with each temperature sensor is enclosed in a protective housing (Patent No. 2448335 "Thermocosa").

The disadvantage of this method is the presence of convection in the well during measurements.

In addition, the above methods allow you to measure the temperature of the air in the well, and not the temperature of the soil, which affects the accuracy of the measurements.

The proposed method allows to increase the accuracy of measurements, as it allows you to measure the temperature of the soil, eliminates the effect of convection in the well on the measurement and allows you to measure the temperature along the entire length of the thermometer wells.

The essence of the method consists in measuring the temperature of the soil using a measuring string lowered into a thermometric well, the casing of a thermometric well is a pipe made of a material with a relatively low coefficient of thermal conductivity (for example, polypropylene), with parts of a material with a relatively high coefficient of thermal conductivity (for example , bushings made of steel), and the measuring string is a pipe having an outer diameter equal to the inner diameter of the casing and illogical in design, in which the metal parts attached thermocouple for temperature measurement.

The technical result provided by the given set of features is to increase the accuracy of measurements, the elimination of air convection in a thermometric well during measurements. Depending on the task, this technical solution will allow for operational, autonomous or continuous monitoring of soil temperature under the bases of buildings and structures, along the subgrade of railways.

The essence of this method is illustrated by drawings, where in FIG. 1 shows a diagram of a thermometric well device for measuring soil temperature; FIG. 2 is a diagram of the device of the measuring garland.

The method is as follows.

In the casing of a thermometric well, which is a pipe made of a material with a relatively low coefficient of thermal conductivity (for example, polypropylene) 1, with parts of a material with a relatively high coefficient of thermal conductivity (for example, steel sleeves) 2, a measuring string, which is a pipe, is immersed, having an outer diameter equal to the inner diameter of the casing, made of a material with a relatively low coefficient of thermal conductivity (for example, polypropylene) 3, with parts and of material with a relatively high coefficient of thermal conductivity (for example, steel sleeves) 4. Thermocouples 5 are attached to the metal parts of the tube of the measuring string to measure the temperature. The measuring string is immersed in the casing until its metal parts are aligned with the metal parts of the casing. If it is necessary to measure the temperature in the soil, the measuring garland is lubricated with a thin layer of heat-conducting substance, such as solid oil, to ensure tight airless contact with the casing. Thus, high measurement accuracy is ensured.

Claims (1)

A method of measuring soil temperature using a measuring string lowered into a thermometric well, characterized in that the casing of the thermometric well is a pipe made of a material with a relatively low coefficient of thermal conductivity (e.g. polypropylene), with parts of a material with a relatively high coefficient of thermal conductivity ( for example, steel sleeves), and the measuring string is a pipe having an outer diameter equal to the inner diameter of the casing, and ogichnuyu in design, in which the metal parts attached thermocouple for temperature measurement.

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