Armoured thermocouple that high temperature high pressure and hig flow speed is used and using method thereof
Technical field
The present invention relates to a kind of armoured thermocouple, particularly relate to a kind of armoured thermocouple and using method thereof that high temperature high pressure and hig flow speed is used that be used for.
Background technology
Existing armoured thermocouple or title bushing type armoured thermal resistance; comprise housing, thermocouple wire and protective casing; thermocouple wire inserts in the head protection sleeve pipe of thermopair; temperature by the protective casing measurement environment; prevent that thermocouple wire is damaged, so the environment for use of thermopair mainly is subjected to the restriction of the adaptedness and the measuring condition of thermopair.Because at present the protective casing of thermopair commonly used adopts common material and structure, so it can only be used under common pressure, temperature and the flow velocity, and environment for use is limited, and range of application is very little.
Armoured thermocouple is owing to measure more accurate; its range of application more and more widely; particularly be applied in the measurement environment of various high pressure-temperature high flow rates; as be used for the high temperature high pressure and hig flow speed state that the ultra supercritical fired power generating unit uses and measure temperature down; the main pipeline that 1000MW ultra supercritical fired power generating unit and 600MW ultra supercritical fired power generating unit need be measured temperature with the parameter that outer protection tube meets with stresses is: 610 ℃ of main steam temperatures; flow velocity 100m/S; static pressure 30MPa, creep tensile strength 85MPa, the required life-span of armoured thermocouple will reach 105 hours (about 11.4).Under the operating mode of such ultra supercritical intensity; after thermopair has born the impulsive force and oscillatory load of outside static pressure, stable state fluid; when stress that portion produces has surpassed meeting with stresses of material itself within it; the protective casing of thermopair can damage; simultaneously its high speed that also can be subjected to measuring fluid is washed away and is worn and torn; therefore the protective casing of thermopair must possess the creep strength of enough high temperature high pressure and hig flow speeds, and thermal response time is short, can accurately measure temperature.
In general, the design of armoured thermocouple, armoured Pt thermal resistance protection protective casing, as reduce thermal response time, improve to measure quality, need to reduce the hot transmission loss in the measuring process, therefore the tube wall of protective casing is got over Bao Yuehao, then weaken the intensity of protective casing thereupon, cause protective casing to damage; Otherwise, for increasing the intensity of thermocouple protective casing, then need improve its thickness, will increase thermal response time, reduce and measure quality, so this is a pair of insoluble contradiction, also be key point of the present invention.
Summary of the invention
Technical matters to be solved by this invention is to overcome the above-mentioned defective of prior art and a kind of armoured thermocouple is provided, and makes it be issued to request for utilization in the high temperature high pressure and hig flow speed condition.
The present invention solves the problems of the technologies described above the technical scheme that is adopted:
The armoured thermocouple that high temperature high pressure and hig flow speed is used; comprise terminal box, band stage clip connecting pipe, flexible joint, extension spray lance, thermocouple wire and protective casing; it is characterized in that: described protective casing is divided into two sections up and down; it is cylindrical that epimere becomes, and diameter is 32-40mm, and hypomere is a truncated cone-shaped; the diameter of hypomere upper surface is 38-48mm; the bottom surface diameter is 22-28mm, cylinder and round platform junction smooth transition, and the bore dia that the centre holds thermocouple wire is slightly larger than the diameter of thermocouple wire.
The crucial part of above-mentioned thermopair is the protective casing structure of thermopair head; by analyzing the weak part of existing thermocouple protective casing structure; the present invention improves the shape and the structure of protective casing; and consider its employed high temperature high pressure and hig flow speed and high flow rate environment and the thermal response time of measuring the thermopair (thermal resistance) of temperature; Theoretical Calculation according to the mechanics of materials, fluid mechanics, oscillation intensity; reach safe handling; accurately measure, determined above-mentioned shape and structure, the size of protective casing with this.
The using method of above-mentioned thermopair, very important when being welded to pipeline with the groove angle of pipeline, be generally 45 degree.
Compared with prior art; the invention has the advantages that: thermopair is by the thermocouple protective casing of above-mentioned design; under the following conditions: when 610 ℃ of main steam temperatures, flow velocity 100m/S, static pressure 30MPa, creep tensile strength 85MPa; its life-span can reach 105 hours (about 11.4); and can correctly measure temperature, therefore meet the request for utilization under the high temperature high pressure and hig flow speed condition fully.
The armoured thermocouple that the high temperature high pressure and hig flow speed of the present invention's design is used, can be widely used in the thermometric under the various high temperature high pressure and hig flow speed conditions, temperature as the measurement steam under 1000MW ultra supercritical fired power generating unit and the 600MW ultra supercritical fired power generating unit working condition, it can accurately measure temperature, again enough intensity can be arranged, use and measuring accuracy reach required technical requirement, and be safe and reliable, can reach the serviceable life in the safe handling cycle.
Description of drawings
The structural representation of the armoured thermocouple that Fig. 1 uses for high temperature high pressure and hig flow speed of the present invention.
Fig. 2 is the structural representation of the protective casing of the embodiment of the invention.
The practical application figure of the armoured thermocouple that Fig. 3 uses for embodiment of the invention high temperature high pressure and hig flow speed.
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
As shown in Figure 1; the armoured thermocouple that high temperature high pressure and hig flow speed is used; it comprises terminal box 1; band stage clip connecting pipe 2; flexible joint 3; extension spray lance 4; protective casing 5 and thermocouple wire 6; thermocouple wire 6 stretches into by terminal box 1; band stage clip connecting pipe 2; flexible joint 3; extension spray lance 4; in the inner core that protective casing 5 is formed; described protective casing 5 is divided into two sections up and down; it is cylindrical that epimere becomes; the bottom surface diameter is 32-40mm, and hypomere is a truncated cone-shaped, and the bottom surface diameter of hypomere circular platform type is 22-28mm; the diameter of upper surface is 38-48mm; cylinder and round platform junction smooth transition, the centre holds the diameter of the slightly larger in diameter of thermocouple wire in thermocouple wire, sees Fig. 2 for details.
Above-mentioned circular platform type length can be decided according to the height of field of employment, and is changeable, is 100mm in the present embodiment.
During use, when the thermopair that above-mentioned high pressure-temperature high flow rate is used was welded to the place of use, in pipeline 8, the position of welding and the groove of welding can influence its usability, were preferably 45 degree, as shown in Figure 3.