Loading test on the oil tank ground settlement performance monitored by an optical parallel scheme

Abstract

A loading test of the ground settlement (GS) performance of the oil tank must be examined before beginning its commercial service. This test requires the sensors to be installed around the oil tank, and the GS is measured while water is being filled in, where the liquid level is read with an ultrasonic radar equipment, etc., to indicate the applied water loads. During the service of the oil tank, loading and unloading corresponding to the oil inlet and outlet are the critical factors to cause the oil tank destruction in a fatigue way. Thus, a regular in-service loading test is the means of evaluating the tank base health condition. However, the sensors for GS measurement of the oil tank are mostly based on a liquid hydraulic sensor, which is an intrinsically static sensor determined by the fluidity of the measurement liquid. In order to meet the instantaneous requirement of the loading test, first, the configuration of the optical GS sensor was designed to suit the simultaneous measurement. Secondly, a data acquisition system was designed by combining the digital signal processing with a field programmable gate array to carry out a parallel multiple channel data collection. This ensures that the GS sensors are interrogated simultaneously to snapshot a GS status of the oil tank, even if its load was changed slowly. A practical oil inlet process was recorded with an ultrasonic radar oil level measurement, and the results of oil tank GS were verified with a manual measurement by using the Electronic Total Station. The effectiveness of our sensor monitoring of the oil tank GS performance during the loading test has been proven.

Transfer-Learning-Based Temperature Uncertainty Reduction Algorithm for Large Scale Oil Tank Ground Settlement Monitoring

“…When the electrical motor moves and satisfies the equal optical path difference condition as , a peak signal can be found in the interference pattern. Using this, the liquid level change can be continuously recorded, and the GS can be deduced [ 3 ].…”

“…From Figure 1 b, the readout at midnight shows the change is limited to within 3 mm for 1 week. Besides this, actual tests have demonstrated that in a loading process, the GS between the totally empty condition and totally full condition can reach about 7 mm [ 3 ]. Based on that, it is believed that in a short time (daytime < 12 h), the fluctuation of GS measurement should all entirely attributable to temperature uncertainty.…”

“…Ground settlement in oil tanks is a critical factor that can compromise their structural integrity and service life [ 1 , 2 , 3 , 4 ], as depicted in Figure 1 a. This emphasizes the importance of prioritizing GS monitoring for large scale infrastructures.…”

“…However, one major challenge being faced is the interference caused by non-uniform temperature fields [ 6 ]. During the daytime, solar irradiation can be impeded by the large size of the oil tank, resulting in significant temperature differences of up to between the sunlit and shaded areas in the summer [ 3 , 6 ]. This temperature difference can impact the HLS directly and lead to considerable temperature uncertainty (large fluctuation of GS measurement).…”

Temperature Uncertainty Reduction Algorithm Based on Temperature Distribution Prior for Optical Sensors in Oil Tank Ground Settlement Monitoring

“…In order to overcome these limitations, researchers have utilized the hydrostatic leveling system (HLS) technique. But, in the oil tank application, two main challenges need to be addressed for the HLS: ensuring fireproof safety and avoiding temperature interference [12].…”