RU204511U1 - Heat flux density measuring device - Google Patents

Abstract

The utility model of the device refers to the means for measuring the amount of heat and can be used to measure the heat flux density on pipelines insulated with fibrous heat-insulating materials of various densities. The technical result of the proposed utility model is to increase the accuracy of measuring specific linear heat losses through thermal insulation of pipelines made of fibrous heat-insulating materials of various densities. The technical result is achieved by the fact that the device for measuring the heat flux density contains a heat flux density converter, made with the possibility of transmitting a signal to an analog-to-digital converter and a personal computer, an air blower, a pressure gauge, according to the proposed utility model, a heat flux density converter flow is made in the form of a compression cuff, on the inner side of which heat flow sensors are fixed, based on the additional wall method, while m compression cuff is a textile cuff with a sewn inside pneumatic chamber connected by pneumatic tubes with a pressure gauge and an air blower. Heat flow sensors are located along the entire length of the cuff. The number of sensors depends on the diameter of the investigated thermally insulated cylindrical object. With the help of a blower, air is injected into the cuff pneumatic chamber, thereby ensuring the density of pressing the heat flow sensors along the entire circumference of the inspected heat-insulated pipeline. The pressure created in the pneumatic chamber, which determines the pressing force of the heat flow sensors to the surface, depending on the density of the insulating material, is regulated using a manometer.

Description

The useful model of the device refers to the means for measuring the amount of heat and can be used to measure the heat flux density on pipelines insulated with fibrous heat-insulating materials of various densities.

State of the art

Known device for a similar purpose, the device ITP-MG 4.03 "Stream". To measure the heat flux density, heat flux sensors are connected to the device. Heat flow sensors based on the additional wall method, which are an element of a flat cylindrical, spherical or other shell, located with a smaller size normal to the surface. The heat flow sensor generates an electrical signal, which is used to judge the values of the heat flow density [1-3].

The disadvantage of the analogue is the complexity of fixing heat flow sensors of the "additional wall" type to the surface of the material of the cylindrical wall, through which heat losses must be determined. For accurate measurements, the heat flow sensor of the "additional wall" type must be tightly pressed against the surface. At the same time, if fibrous thermal insulation is used as a heat-insulating material for insulating pipelines, then when attaching the heat flow sensor to the surface of the insulating material, it is necessary to take into account the density of the material in order to avoid mechanical damage or changes in the density of the material at the point of attachment of the sensor. The magnitude of the heat flux through the fibrous insulating materials depends on the density of the material, therefore, to accurately determine the magnitude of the heat flux, it is necessary to regulate the force of pressing the sensor to the surface, ensuring the tightness of the contact between the sensor and the surface under study, but at the same time, preventing the material from compaction at the place of the sensor attachment.

The technical result of the proposed utility model is to improve the accuracy of measuring specific linear heat losses through thermal insulation of pipelines made of fibrous thermal insulation materials of various densities.

The technical result is achieved in that the device for measuring the heat flux density contains a heat flux density converter configured to transmit a signal to an analog-to-digital converter and a personal computer, an air blower, a pressure gauge, according to the proposed utility model, the heat flux density converter is made in the form of a compression cuff, on the inside of which heat flow sensors are fixed, based on the additional wall method, while the compression cuff is a textile cuff with a pneumatic chamber sewn inside, connected by pneumatic tubes to a pressure gauge and an air blower.

Heat flow sensors are located along the entire length of the cuff. The number of sensors depends on the diameter of the investigated thermally insulated cylindrical object. With the help of a blower, air is injected into the cuff pneumatic chamber, thereby ensuring the density of pressing the heat flow sensors along the entire circumference of the inspected heat-insulated pipeline. The pressure created in the pneumatic chamber, which determines the pressing force of the heat flow sensors to the surface, depending on the density of the insulating material, is regulated using a manometer.

The essence of the utility model is illustrated by drawings, which show:

in fig. 1 - location of the device for measuring the heat flux density on the inspected pipeline in thermal insulation;

in fig. 2 is a general view of a device for measuring heat flux density.

In the figures, the numbers indicate:

1 - Heat flow sensors;

2 - Compression cuff;

3 - Pneumatic chamber;

4 - Pneumatic tubes;

5 - Manometer;

6 - Air blower;

7 - Electric wires;

8 - Analog-to-digital converter;

9 - Personal computer (PC);

10 - Ring for fastening;

11 - Pipelines;

12 - Thermal insulation material.

The device works as follows.

On the pipeline 11 (Fig. 1), insulated with heat-insulating material 12, the heat losses through which must be determined, a cuff 2 is put on. The cuff is fixed with a metal ring for fastening 10 (Fig. 2). Heat flow sensors 1 (Fig. 2) are located on the inner part of the cuff. With the help of a blower 6, air is injected into the pneumatic chamber 3 of the compression cuff 2 through the pneumatic tube 4. The required pressure in the pneumatic chamber is controlled using a pressure gauge 5 connected to the compression cuff 2 using pneumatic tubes 4. The pressure in the pneumatic chamber is selected so as to ensure tight pressing of the heat flow sensors to surface of the heat-insulated pipeline, but at the same time prevent mechanical damage or changes in the density of the material at the cuff installation site. Heat flow sensors are made with the possibility of transmitting an analog signal to an analog-to-digital converter 8 and a personal computer 9. The ADC reads the signal from the sensors and converts it from analog to digital. The signal is processed, the values of the heat flux density are displayed on the PC screen 9.

Information sources

1. GOST 25380-2014 Buildings and structures. A method for measuring the density of heat fluxes passing through the building envelope. - M .: Standartinform, 2015 .-- 14 p.

2. GOST 26263-84 Soils. Method for laboratory determination of thermal conductivity of frozen soils. - M .: Publishing house of standards, 1985 .-- 9 p.

3. Gerashchenko O.A. Basics of heat metering. Publishing house "Naukova Dumka", Kiev, 1971.

Claims (2)

1. A device for measuring heat flux density, containing a heat flux density converter, configured to transmit a signal to an analog-to-digital converter and a personal computer, an air blower, a pressure gauge, characterized in that the heat flux density converter is made in the form of a compression cuff, with an internal the sides of which are fixed heat flow sensors based on the additional wall method. 2. The device according to claim 1, characterized in that the compression cuff is a textile shell with a pneumatic chamber sewn inside, connected by pneumatic tubes to a pressure gauge and to an air blower.

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