An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are deri...An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are derived based on the asymptotic theory. The signal is used for the open loop experiment. The design constraint is the power of the process signal or the process input signal. The results give guideline for identification application.展开更多
Wax sedimentation in pipelines is a severe crude oil production and transportation challenge.Pipeline surface roughness is experienced at the early stages of the problem;with time,the effective pipe cross-sectional ar...Wax sedimentation in pipelines is a severe crude oil production and transportation challenge.Pipeline surface roughness is experienced at the early stages of the problem;with time,the effective pipe cross-sectional area is reduced due to pipeline wax plugging,causing pumping pressure increase,equipment failures,and blockages,resulting in unnecessary downtime costs and pipeline abandonments in the worst situation.This paper reviews mathematical and experimental loops models used for pipeline solid wax predictions and calculations as functions of pressure,temperature,and fluid composition;by assessing model's Assumptions,strengths and weaknesses.It is found that most mathematical models applied molecular-diffusion mechanisms in modeling and neglected shear effects;which resulted in wax over-prediction.Experimental loop was time-consuming due to mounting and dismounting of test section during wax deposition measurements;our modification has included sensor-integration to detect,measure,and analyze wax deposition;Reliable wax predictions models are essential to properly design pipelines and adopt cost-effective strategies for wax deposition prevention,control,and removal.展开更多
基金High Technology Research and Development Program me of China (No.2 0 0 1AA413 13 0 )
文摘An optimal experiment design (DED) with respect to the use of designing model-base controller was studied. The mean squared error at the setpoint is chosen as the performance criterion. Simple design formulas are derived based on the asymptotic theory. The signal is used for the open loop experiment. The design constraint is the power of the process signal or the process input signal. The results give guideline for identification application.
基金the National Natural Science Foundation of China[Grant number 51704319 and 51574274].
文摘Wax sedimentation in pipelines is a severe crude oil production and transportation challenge.Pipeline surface roughness is experienced at the early stages of the problem;with time,the effective pipe cross-sectional area is reduced due to pipeline wax plugging,causing pumping pressure increase,equipment failures,and blockages,resulting in unnecessary downtime costs and pipeline abandonments in the worst situation.This paper reviews mathematical and experimental loops models used for pipeline solid wax predictions and calculations as functions of pressure,temperature,and fluid composition;by assessing model's Assumptions,strengths and weaknesses.It is found that most mathematical models applied molecular-diffusion mechanisms in modeling and neglected shear effects;which resulted in wax over-prediction.Experimental loop was time-consuming due to mounting and dismounting of test section during wax deposition measurements;our modification has included sensor-integration to detect,measure,and analyze wax deposition;Reliable wax predictions models are essential to properly design pipelines and adopt cost-effective strategies for wax deposition prevention,control,and removal.
