The core requirements of photovoltaic equipment for thermocouples: The photovoltaic manufacturing process involves high temperature and corrosive environments, and the performance of thermocouples is strict:
1. High temperature resistance
The temperature of the monocrystalline silicon growth furnace (crystal pulling furnace) needs to reach more than 1500°C, and **B type (platinum rhodium 30-platinum rhodium 6) or S type (platinum rhodium 10-platinum) thermocouples are used.
The temperature of the cell sintering process is about 800-1000°C, and K-type (nickel-chromium-nickel-silicon) or N-type (nickel-chromium-silicon-nickel-silicon) thermocouples are commonly used.
2. Corrosion resistance
Silicon vapor and acid gas are present in the silicon smelting and coating process, and the thermocouple sheath material needs to be corrosion-resistant (such as ceramics, high-purity alumina, quartz tubes).
3. Long-term stability
Photovoltaic equipment is continuously operated, and the thermocouple needs to maintain accuracy (error <± 1.5°C) at high temperatures, and the life span is usually 1-3 years.
The main application scenarios of thermocouples for photovoltaic equipment
Process link Temperature range Thermocouple type Technical requirements
Monocrystalline silicon 1400-1600°C S-type, B-type High precision, low drift
Cell sintering 800-1000°C K-type, N-type fast response, anti-oxidation