For the installation of bimetal thermometers, attention should be paid to the accuracy of temperature measurement, safety and reliability, and convenient maintenance, and does not affect the operation and production operation of equipment, to meet the above requirements, in the selection of thermal resistance installation site and insertion depth should pay attention to the following points:
(1) In order to ensure sufficient heat exchange between the measuring end of the thermal resistance and the measured medium, the location of the measuring point should be reasonably selected, and the thermal resistance should be avoided near the dead Angle of the valve, elbow, pipe and equipment. (2) Thermal resistance with protective sleeve has heat transfer and heat dissipation loss. In order to reduce measurement error, thermocouple and thermal resistance should have sufficient insertion depth:
A. For the thermal resistance measuring the temperature of the fluid in the center of the pipe, the measuring end should generally be inserted into the center of the pipe (vertical installation or inclined installation). If the pipe diameter of the flow body being measured is 200mm, the insertion depth of the thermal resistance should be selected as 100mm;
B. For the temperature measurement of high temperature, high pressure and high-speed fluid (such as the temperature of main steam), in order to reduce the resistance of the protective sleeve to the fluid and prevent the fracture of the protective sleeve under the action of the fluid, shallow insertion of the protective tube or the thermal resistance of the hot sleeve can be adopted. The depth of the thermal resistance protection sleeve inserted into the main steam pipe should not be less than 75mm; The standard insertion depth of hot sleeve thermal resistance is 100mm;
C. If it is necessary to measure the temperature of flue gas in the flue, even though the flue diameter is 4m and the insertion depth of thermal resistance is 1 m;
D. When the measuring element is inserted into a depth of more than 1m, it should be installed vertically as far as possible, or support frame and protection casing should be added.
