In modern thermal power plants, thermocouples are key temperature measuring components, and their stability and life directly affect the safe operation and energy efficiency management of equipment. WRER2-13 high-temperature and high-pressure sleeve thermocouples are widely used in high-temperature and high-pressure environments such as boiler combustion chambers, flues and steam turbines due to their unique structural design and material properties. However, in flue gas conditions containing hydrogen sulfide (H₂S), the corrosion and failure problems of thermocouples are particularly prominent. H₂S, as a highly corrosive gas, is prone to chemical reactions with metal materials under high temperature conditions to form sulfide deposits, leading to local corrosion, stress cracking and even fracture. In response to this challenge, WRER2-13 effectively delays the corrosion process and extends its service life by optimizing multi-dimensional measures such as material selection, structural design, surface protection technology and operation management.

1. Anti-corrosion properties of material and structural design

The core advantage of the WRER2-13 heat sleeve thermocouple lies in the design of its heat protection tube. Unlike traditional prefabricated structures, the protective tube adopts deep blind hole processing technology to avoid the existence of welding joints, thereby eliminating the problems of grain coarsening and stress concentration caused by welding stress. This design not only improves the mechanical strength, but also significantly reduces the risk of sulfide stress corrosion cracking. In terms of material selection, the protective tube of WRER2-13 usually adopts high-temperature resistant high-alloy steel, which shows excellent resistance to sulfide corrosion in H₂S environment. Its crystal structure is stable and can effectively resist corrosion products such as iron sulfide generated by the reaction of hydrogen sulfide with the metal surface at high temperature. In addition, the packaging process of the armored temperature measuring element further enhances the overall sealing of the thermocouple and reduces the penetration path of corrosive media in the flue gas.

2. Application of surface protection and coating technology

In H₂S-containing flue gas, the oxide layer and sulfide layer on the surface of the armored thermocouple are the main causes of corrosion. WRER2-13 constructs a multi-level protection barrier through surface passivation treatment and functional coating technology. For example, a dense ceramic-based or metal-based coating is formed on the outer surface of the protective tube by plasma spraying or chemical vapor deposition. These coatings have extremely low sulfur diffusion coefficients and can effectively block direct contact between H₂S and the base material. At the same time, the microporous structure of the coating can inhibit the deposition and expansion of sulfides and reduce the occurrence of local corrosion.

3. Optimization and dynamic regulation of operating environment

The life of the thermocouple depends not only on its own materials and structure, but also on the operating environment in which it is located. In the actual application of power plants, WRER2-13 further extends the service life by dynamically regulating flue gas parameters and installation strategies. For example, during boiler combustion, the concentration of H₂S in the flue gas is reduced by precisely controlling the air-fuel ratio and fuel ratio. Studies have shown that when the H₂S content in the flue gas drops from 1000 ppm to below 500 ppm, the sulfide corrosion rate can be reduced by about 40%. In addition, the installation location of WRER2-13 needs to avoid areas where the flue gas velocity changes dramatically to reduce the synergistic effect of wear and corrosion caused by air flow scouring. For high corrosion risk areas such as flue elbows or heat exchanger outlets, local insulation layers or guide plate designs can be used to reduce the time that thermocouples are exposed to high-temperature sulfiding environments.

4. Maintenance strategy and fault warning mechanism

Even if multiple protective measures are taken, thermocouples will inevitably accumulate corrosion damage during long-term operation. WRER2-13 uses intelligent maintenance strategies and online monitoring technology to achieve dynamic evaluation of life and risk warning. For example, its matching temperature transmitter can collect the output signal fluctuations of the thermocouple in real time, and establish a corrosion trend model based on historical data. When an abnormal signal is detected, the system will trigger an early warning mechanism to prompt the operation and maintenance personnel to conduct targeted inspections. In addition, regular non-destructive testing can evaluate the thickness loss and internal defects of the protective tube, providing a basis for replacement decisions. During shutdown and maintenance, high-pressure water jets or chemical cleaning technology are used to remove sulfide deposits on the surface of the thermocouple to restore its temperature measurement accuracy and corrosion resistance.

5. Performance verification in practical applications

In the high-temperature flue of a coal-fired power plant, the WRER2-13 thermocouple was installed at the flue gas temperature monitoring point before the desulfurization system. The flue gas temperature in this area is as high as 550℃, and the H₂S concentration is about 800 ppm. After 18 months of continuous operation, only a slight oxidation color appeared on the surface of the thermocouple protection tube, and no obvious cracks or perforations were found. In contrast, the traditional assembled thermocouple failed due to sulfide corrosion after 12 months of service under the same working conditions. This case shows that WRER2-13 has significantly improved its durability in H₂S-containing environments through material optimization and structural innovation. In addition, in the steam pipeline of another nuclear auxiliary power generation system, the WRER2-13 thermocouple has been operating stably for more than 24 months under the coexistence of 600℃, 30 MPa high-pressure steam and trace H₂S, and its temperature measurement error has always been controlled within ±1.5℃, verifying its reliability under extreme working conditions.

In a high-temperature and high-pressure flue gas environment containing H₂S, the WRER2-13 high temperature thermocouple effectively slows down the corrosion process and significantly extends its service life through the synergy of material innovation, structural optimization, surface protection and operation management. This technical solution not only reflects the adaptability of modern industrial sensors under harsh working conditions, but also provides reliable technical support for the sustainable development of the energy industry. With the continuous advancement of materials science and intelligent monitoring technology, WRER2-13 and its similar products will play a key role in more complex environments, helping industrial automation to move to a higher level.

When looking for high-quality, reliable thermocouples, YOYIK is undoubtedly a choice worth considering. The company specializes in providing a variety of power equipment including steam turbine accessories, and has won wide acclaim for its high-quality products and services. For more information or inquiries, please contact the customer service below:
E-mail: sales@yoyik.com
Tel: +86-838-2226655
Whatsapp: +86-13618105229

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