Design and economical evaluation of components onboard LNG-FPSOs considering vibration and motion
MetadataVis full innførsel
AbstractLNG FPSO s are getting more interest as the new oil and gas reserves are found in sub seas. But a main technical challenge has been identified as the liquefaction systems since its considered as the bottle in natural gas processing. The LNG FPSO s are subjected to motion in the sea and it s been observed that it can affect the flows inside the heat exchangers. Previous research conducted by NTNU and SINTEF research showed that flow patterns are getting changed and disturbed during the motion. Also the phenomenon of multi phase flows and its heat transfer mechanism is studied during the work. The main motivation of this work is to conduct the experiment in the laboratory to observe the changes in flow patterns when motion is induced. For the current study only horizontal motion has been considered due to the technical difficulties that are involved in setting up the experiment. A simple electric motor with eccentric extended arm is used to induce the motion to the platform. The platform was hinged in such a way that it will allow to move in the horizontal plane with a pivoted axis.The reading has been recorded during the flow when the experiment is in steady state and also when the motion is induced in the setup. Later these results are analyzed using the Matlab coding. Also visual aids have been used to record the flow during the experiment. The results are described in the work by the aid of photographs and also by using the graphs. It should be mentioned here that when motion is induced in test section the signals that has been obtained showed very large disturbance and it was very difficult to be analyzed using Matlab. The code was modified but still the results are non recognizable since the Matlab wasn t able to recognize steady state of the flows. Due to this the visual observations by the student and the visual aids in the form of photographs and video has been used to analyze the results. The flow patterns where changing abruptly and the bigger slug flow was observed to be breaking in to smaller ones. Also the velocity of the flow was observed to be changed by the motion. The results are discussed in this report.