Abstract: This paper presents a fire alarm system based on fluorescence optical fiber temperature sensing technology, which can be used for real?time temperature monitoring and fire warning of petroleum and petrochemical storage tanks. The sensor probe package structure is small, high temperature and corrosion resistance, can be directly into the tank to measure the actual gas or liquid phase temperature, truly reflect the temperature change of the medium in the tank. The sensor can withstand the temperature of more than 250 ℃ for a long time, and can monitor the temperature of the high temperature residual oil storage tank of more than 160 ℃. The 650 nm laser source with high stable power output and red light excitation phosphor material were selected, and the excitation fluorescence wavelength was in the near?infrared band. The transmission attenuation in the fiber was small, the working distance was long, the temperature measurement accuracy was high, and the long?term stability was good. The temperature measuring host has a plurality of temperature monitoring channels, each channel is independent, and can monitor different zones of the tank. Online real?time monitoring platform can realize the remote communication with the host temperature measurement. The monitoring platform supports spectrum data acquisition, waveform display, real?time millisecond temperature data acquisition, oil tank hot spot location simulation, overtemperature warning and other functions. The platform is developed in a split structure with high response speed and low fault tolerance.

Key words:  fluorescent fiber optic sensor, high temperature oil storage tank, temperature monitoring, fire warning