STTR Phase II: Active Fiber Optic Sensor Array for Cryogenic Fuel Monitoring and Management

这项小型企业技术转让（STTR）二期项目将开发一种多功能有源光纤布拉格光栅传感器技术，用于监测和管理液态氢和液化天然气等低温燃料。该技术利用光纤内光来主动调节传感器温度，这将大大提高光纤传感器在低温环境中的响应性和灵敏度。通过在光纤光栅传感器上涂上功能薄膜，可以在低温下同时测量液体燃料水平、空间分布、氢浓度和温度。在这个项目中开发的有源传感器不受电磁干扰，可以在一根光纤中复用，这就允许在地面和太空中使用一根光纤和一根光纤馈通解决方案进行低温燃料管理。该项目的更广泛影响/商业潜力将是开发一种谨慎的传感技术和系统，以提高使用液态氢和液化天然气燃料的安全性和可靠性。作为未来几十年为美国经济提供动力的主要替代燃料，它们具有很高的经济价值，需要精确可靠的计量和管理。拥有一个灵活的、多用途的系统，可以绝对放心地安装来监测和管理这些燃料，以及安装的系统的健康状况，将对接受这些挥发性燃料作为安全的替代能源产生重大影响。在一根光纤上安装多个传感器的能力将使低温壁的穿透更安全、更经济，纤维的低腐蚀电位将使传感器能够沿着地下管道放置。相同的基本有源光纤传感器技术有可能扩展到燃料流量和其他经济有用的功能。

This Small Business Technology Transfer (STTR) Phase II project will develop a multi-functional active fiber Bragg grating sensor technology for the monitoring and management of cryogenic fuel such as liquid hydrogen and liquefied natural gas. The proposed technology uses in-fiber light to actively adjust sensor temperature, which will drastically improve responsivity and sensitivity of fiber sensors in the cryogenic environment. By coating fiber Bragg grating sensors with functional films, liquid fuel levels, spatial distribution, hydrogen concentration, and temperature can be simultaneously measured at cryogenic temperatures. Active sensors to be developed in this program are immune to electromagnetic interference and can be multiplexed in a single fiber, which allows a one-fiber and one-fiber-feedthrough solution for the cryogenic fuel management on the ground and in space. The broader impact/commercial potential of this project will be the development of a prudent sensing technology and system to improve the safety and reliability of the use of both liquid hydrogen and liquefied natural gas fuels. As major alternative fuels to power the U.S. economy for decades to come, they share a high economic value that requires accurate and reliable metering and management. Having a flexible, multi-use system available that can be installed with absolute confidence to monitor and manage these fuels, as well as the health of installed systems, will have a major impact on the acceptance of these volatile fuels as safe alternative energy sources. The ability to multiplex many sensors on a single fiber will enable safer and more economical penetrations in cryogenic walls and the low corrosion potential of the fibers will enable sensors to be placed along piping underground. The same basic active fiber sensor technology has the potential to be extended to fuel flow and other economically useful functions.