The WRN2-630 thermocouple is a temperature measurement device made of a wear-resistant protective tube made of special materials such as high-chromium cast iron and K alloy. This design is intended to improve the wear resistance and corrosion resistance of the thermocouple, thereby extending its service life in harsh environments. The WRN2-630 thermocouple is suitable for various high-temperature and high-wear scenarios including circulating fluidized bed boilers, coal mills, cement plants, and smelters in power plants. Its wide operating temperature range can meet the needs of temperature monitoring inside steam turbines.

The high temperature, high pressure and highly corrosive environment inside the steam turbine place extremely demanding requirements on temperature measurement equipment. Although the WRN2-630 thermocouple was designed for use in harsh environments, its performance may still be affected by the following factors during the long-term operation of the steam turbine:

• High temperature aging: The thermoelectric material of the thermocouple may age in a high temperature environment for a long time, resulting in changes in the thermoelectric characteristics, which affects the measurement accuracy. High temperature also accelerates the aging of insulating materials and reduces the insulation performance of the thermocouple.
• Chemical corrosion: Corrosive media inside the turbine, such as acid and alkali steam, oxides, etc., may corrode the protective tube and wiring of the thermocouple, affecting its mechanical strength and electrical performance.
• Mechanical wear: In a high-wear environment, such as particle impact or solid material flow, the protective tube of the thermocouple may be worn, reducing its protection effect or even causing damage to the thermocouple.
• Vibration effect: Vibration during turbine operation may cause the fixings of the thermocouple to loosen, affecting the contact tightness between the thermocouple and the object being measured, thereby affecting the accuracy of temperature measurement.
• Thermal cycle fatigue: During the start-up and shutdown of the turbine, the frequent temperature changes experienced by the thermocouple will cause thermal cycle fatigue, which may cause changes in the microstructure of the material and affect its long-term stability.

WRN2-630 thermocouples may indeed face the risk of performance degradation in the long-term operation environment of the turbine. However, by taking some maintenance and calibration measures, their service life can be significantly extended and their measurement accuracy and reliability can be maintained during turbine operation, such as: regularly inspect the appearance of the thermocouple, evaluate the integrity of its protection tube and the reliability of the wiring, and clean or replace it when necessary; regularly calibrate the thermocouple to confirm whether its measurement accuracy meets the standard and promptly detect and correct deviations; select materials that are more suitable for the turbine environment, such as high-temperature resistant alloys, and optimize the design of the thermocouple, such as improving the protection tube structure to enhance its ability to resist high temperature, corrosion and wear; consider adding anti-vibration devices, such as spring brackets or shock-absorbing materials, to reduce the impact of vibration on the thermocouple during design.

Yoyik can offer many spare parts for power plants as below:
PRINTED CIRCUIT BOARD IO PORT PCB JD10095
Two-stage Deviation Switch HKPP-12-30
capacitive linear position sensor 0-200mm
linear displacement measurement C9231129
CONNECTOR R40K02MONSM 2D 3569
Electrical actuator with motor ZHB2500-25
Dold Emergency Stop and Safety Gates LG 5925.48/6X
Pull cord sensor XD-TA-E
Presure Transmitter for kiln thrust PN35-P250M20H3AQ
Display Unit 71386715
OIL LEVEL INDICATOR YZF2-250(TH)
LVDT 0508.902T0102.AW021
temperature sensor pt100 3 wire WZPK2-336
SG Three-phase Dry Type Transformer DFFG-10KVA
liquid level sensor types UHZ-10007B1000T1.1DN25PN16V
Hydrogen Leakage Detection Sensor KQF1500
Speed Sensor ZS-04-065-3000
SENSOR LVDT DET400A
Protective Relay CSC 241C
NEPM meter Hz