Experimental Study of Large-Temperature-Range and Long-Period Monitoring for LNG Marine Auxiliary Based on Fiber Bragg Grating Temperature Measurement

Abstract

Temperature is a key variable to evaluate the energy consumption and thermodynamic performance of traditional marine auxiliary machinery, chillers and piping systems. In particular, for the cryogenic storage tanks and fuel gas supply systems of LNG ships, explosion-proof and low-temperature-resistance properties bring new challenges to the onboard temperature measurement and monitoring. In order to promote the development of high-performance and safer monitoring systems for LNG ships, this paper adopted fiber Bragg grating (FBG) technology to ensure the measurement safety and accuracy of temperature sensors, and performs a series of experiments in a large temperature range on the chiller, pipeline, and cryogenic storage tank of an LNG ship and their long-term reliabilities. Firstly, the principle and composition of the designed FBG temperature sensors are introduced in detail, and the measurement accuracy and range of different metal-coated optical fibers were tested in a large temperature range and compared against the traditional thermistors. Then, the effects of different operating conditions of the LNG marine chiller system and cryogenic storage tank on the temperature measurements were investigated. In addition, the drift degrees of the optical fibers and industrial thermistors were analyzed to figure out their reliabilities for long-term temperature measurements. The results showed that for the long-period (16 months) monitoring of LNG ships in a large temperature range (105–315 K) under different shipping conditions, the optical temperature measurement based on FBG technology has sufficient accuracy and dynamic sensitivity with a higher safety than the traditional thermoelectric measurement. Besides, the ship vibration, ambient humidity, and great temperature changes have little impact on its measurement reliability and drifts. This research can provide references and technical supports to the performance testing systems of LNG ships and other relevant vessels with stricter safety standards.

Marine Structural Health Monitoring with Optical Fiber Sensors: A Review

“…Due to its characteristics of multi-point monitoring, a quasi-distributed FBG sensor can realize the health monitoring of marine structures such as drilling platforms [ 112 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 ], submarine pipelines [ 116 , 125 , 126 , 127 ], bridges [ 3 , 128 , 129 , 130 , 131 , 132 , 133 ], dams [ 134 , 135 , 136 , 137 ], and hulls [ 15 , 138 , 139 , 140 , 141 , 142 , 143 , 144 , 145 ].…”

“…The FBG sensor has promoted the development of the hull safety monitoring system for the past few years. Han et al [ 139 ] employed FBG sensing technology to monitor the temperature of a cryogenic storage tank, pipeline, and water chiller. Through a series of experiments in a wide temperature range, the FBG sensors with temperature-sensitive metal coating materials were proved to have better reliability for long-term temperature measurements and higher safety than those of the traditional thermistors.…”

Optimizing Energy Management and Case Study of Multi-Energy Coupled Supply for Green Ships

“…However, ships that primarily rely on diesel engines have become major sources of air pollution and climate change worldwide [2]. In response to growing global environmental concerns, countries have implemented stricter environmental regulations, demanding the reduction of emissions, and the adoption of clean energy sources in the ship industry to promote sustainability [3].…”

High Sensitivity Cryogenic Temperature Sensors Based on Arc-Induced Long-Period Fiber Gratings

“…Systems operating at cryogenic temperatures are becoming increasingly important in the energy sector, transportation, medicine technology and many other fields (high energy physics, military, aerospace, etc.) [ 1 , 2 , 3 ]. Some applications also use superconducting magnets and high magnetic fields requiring electromagnetic shield and heat transfer control of their monitoring devices [ 4 , 5 , 6 ].…”