scholarly journals Calculation method for the amount of contaminant oil during sequential transportation through product oil pipelines

2020 ◽  
Vol 38 (4) ◽  
pp. 1014-1033
Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Weibiao Qiao ◽  
Mohammadamin Azimi

A considerable amount of oil contamination is caused by the presence of the trailing oil. This paper aims to simulate and analyze the influences of trailing oil on the quality of oil products in undulating sections. By studying the formation mechanism of mixed oil at inclining pipeline sections and the influences of velocity and oil batches on incline sections, as well as both ups and downs, the correlation is obtained between replacement time of different batches and velocity at various sections. By applying FLUENT 14.5, the maximum time of volume fraction of contaminant oil from 1% to 99% is simulated at cross-sections among different pipeline sections. Aiming at the relationship between oil product replacement time and change time of mixing section volume fraction and flow velocity, the mixing increment of undulating section relative to straight section is obtained. Combining with the empirical mixing length calculation equation, the equation for calculating mixing length considering terrain undulation is obtained. Combined with the actual operation data of Lan-Chengyu’s product oil pipeline, the error of the new mixed oil length calculation equation and actual oil mixing is 0.7966%. Excessive cutting amount of mixed oil will result in the waste of refined oil, and the less cutting amount will cause pollution of refined oil. The new mixed oil length calculation equation can more accurately guide the oil mixing cutting work at the oil station.

Author(s):  
Jing Gong ◽  
Jian Cai

Regulating valves are the important components of control system on oil pipeline. The opening of the valves is changed to regulate flow and pressures of pipelines. Operating characteristic of valves is the most important factor influencing the regulating quality, and the distortion is great in actual operation with the variation of working conditions. Beginning with the inherent flow and resistance characteristics of regulating valves, the coefficient of discharge was adjusted considering the influence of fluid viscosity. The relationship between the deformity characteristics of valves and ratio of pressure cut down or turndown ratio was discussed. The system made up by a pump, a valve and a tank was an example to analyze the factors affected the operating characteristic of valves in the actual operation. The influences of different closing valve times, different closing valve laws and different ratio of pressure cut down or turndown ratio on the operating characteristic of valves were analyzed by simulation using Visual Basic program. The results indicated that the operating characteristics of valves were different. And the method of two-stage closing valve was adopted according to the changes of operating characteristic of valves by different closing valve time, different shutting valve laws. The distortion degree of valves in the operation of pipeline was decreased mostly. Then the selection measures of regulating valves were discussed. The factors influencing operating characteristic of valves were analyzed comprehensively. Theory criteria can be provided for selecting regulating valves of pipeline correctly. It is also the key to stable and economically operation control of pipelines.


Processes ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Shanbi Peng

Trailing oil is the tail section of contamination in oil pipelines. It is generated in batch transportation, for which one fluid, such as diesel oil follows another fluid, such as gasoline, and it has an effect on the quality of oil. This paper describes our analysis of the formation mechanism of trailing oil in pipelines and our study of the influence of dead-legs on the formation of trailing oil. We found that the oil replacement rate in a dead-leg is exponentially related to the flow speed, and the length of the dead-leg is exponentially related to the replacement time of the oil. To reduce the amount of mixed oil, the main flow speed should be kept at about 1.6 m/s, and the length of the dead-leg should be less than five times the diameter of the main pipe. In our work, the Reynolds time-averaged method is used to simulate turbulence. To obtain contamination-related experimental data, computational fluid dynamics (CFD) software is used to simulate different flow rates and bypass lengths. MATLAB software was used to perform multi-nonlinear regression for the oil substitution time, the length of the bypass, and the flow speed. We determined an equation for calculating the length of the trailing oil contamination produced by the dead-leg. A modified equation for calculating the length of the contamination was obtained by combining the existing equation for calculating the length of the contamination with new factors based on our work. The amounts of contamination predicted by the new equation is closer to the actual contamination amounts than predicted values from other methods suggested by previous scholars.


Author(s):  
Enbin Liu ◽  
Wensheng Li ◽  
Hongjun Cai ◽  
Shanbi Peng

Trailing oil is the tail section of contamination. There are two main reasons for the formation of trailing oil, one is the effect of laminar flow boundary layer, the other is the outflow of the preceding batch remained in the dead-legs. In the batch transportation of refined oil, under the action of viscous force, the preceding batch forms laminar boundary layer near the pipe wall and stays on the pipe wall, resulting in the phenomenon of contamination trailing and formation of trailing oil. When oil passes through the valve chamber of the oil transportation station, dead-leg will be formed. Due to gravity and convection diffusion, preceding batch flowing from dead-legs will form trailing oil in the pipeline. The phenomenon of trailing oil exists in the process of batch transportation, which will have an effect on the quality of oil. In this paper, Reynolds time-averaged method is used to simulate turbulence.Computational Fluid Dynamics(CFD) software is used to simulate different flow rates and bypass lengths to obtain contamination-related experimental data.Matlab software is used to perform multi-nonlinear regression for the oil substitution time, the length of the bypass and the flow rate. The formula for calculating the length of the trailing oil produced by the dead-leg is obtained. The modified formula for calculating the length of the contamination is obtained by combining the existing formula for calculating the length of the contamination.


2016 ◽  
Vol 30 (2) ◽  
pp. 76-86 ◽  
Author(s):  
Judith Meessen ◽  
Verena Mainz ◽  
Siegfried Gauggel ◽  
Eftychia Volz-Sidiropoulou ◽  
Stefan Sütterlin ◽  
...  

Abstract. Recently, Garfinkel and Critchley (2013) proposed to distinguish between three facets of interoception: interoceptive sensibility, interoceptive accuracy, and interoceptive awareness. This pilot study investigated how these facets interrelate to each other and whether interoceptive awareness is related to the metacognitive awareness of memory performance. A sample of 24 healthy students completed a heartbeat perception task (HPT) and a memory task. Judgments of confidence were requested for each task. Participants filled in questionnaires assessing interoceptive sensibility, depression, anxiety, and socio-demographic characteristics. The three facets of interoception were found to be uncorrelated and interoceptive awareness was not related to metacognitive awareness of memory performance. Whereas memory performance was significantly related to metamemory awareness, interoceptive accuracy (HPT) and interoceptive awareness were not correlated. Results suggest that future research on interoception should assess all facets of interoception in order to capture the multifaceted quality of the construct.


2002 ◽  
Author(s):  
R. Arnold ◽  
A. V. Ranchor ◽  
N. H. T. ten Hacken ◽  
G. H. Koeter ◽  
V. Otten ◽  
...  

2020 ◽  
Vol 29 (12) ◽  
pp. 52-58
Author(s):  
E.P. Meleshkina ◽  
◽  
S.N. Kolomiets ◽  
A.S. Cheskidova ◽  
◽  
...  

Objectively and reliably determined indicators of rheological properties of the dough were identified using the alveograph device to create a system of classifications of wheat and flour from it for the intended purpose in the future. The analysis of the relationship of standardized quality indicators, as well as newly developed indicators for identifying them, differentiating the quality of wheat flour for the intended purpose, i.e. for finished products. To do this, we use mathematical statistics methods.


2019 ◽  
Vol 9 (4) ◽  
pp. 413-420
Author(s):  
Amella Gusty ◽  
Dachriyanus Dachriyanus ◽  
Leni Merdawati

Kinerja perawat merupakan hasil yang dicapai dalam melaksanakan asuhan keperawatan di rumah sakit. Terciptanya asuhan keperawatan yang optimal sangat diperlukan dukungan dari pihak rumah sakit salah satunya adalah menciptakan kualitas kehidupan kerja baik bagi perawat. Penelitian ini bertujuan untuk mengetahui hubungan antara kualitas kehidupan kerja terhadap kinerja perawat pelaksana di RSUD Teluk Kuantan. Jenis penelitian kuantitatif dengan pendekatan cross sectional. Jumlah sampel 120 responden yang diperoleh melalui proportionate simple random sampling. Hasil penelitian menunjukkan kualitas kehidupan kerja perawat RSUD Teluk Kuantan berada pada kategori sedang, kinerja perawat berada pada kategori kurang baik. Berdasarkan analisis kedua variabel teridentifikasi bahwa tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana dengan  p value 0,817. Dimensi work context merupakan komponen yang memiliki hubungan dengan kinerja perawat pelaksana dengan p value 0,008, dimensi work life  tidak berhubungan secara signifikan dengan kinerja perawat. Kesimpulan penelitian diketahui tidak ada hubungan antara kualitas kehidupan kerja dengan kinerja perawat pelaksana. Ada hubungan dimensi work context dengan kinerja perawat pelaksana. Tidak ada hubungan dimensi work life dengan kinerja perawat.   Kata kunci: kualitas kehidupan kerja, kinerja, perawat pelaksana   THE RELATIONSHIP BETWEEN THE QUALITY OF WORK LIFE AND THE PERFORMANCE OF IMPLEMENTERS NURSES   ABSTRACT Nurse performance is the result achieved in implementing nursing care in a hospital. The creation of optimal nursing care is very much needed support from the hospital, one of which is to create a good quality of work life for nurses. This study aims to determine the relationship between the quality of work life and the performance of nurses at the Kuantan District Hospital. This type of quantitative research with cross sectional approach. The number of samples of 120 respondents obtained through proportionate simple random sampling. The results showed that the quality of work life of nurses at the Kuantan District Hospital was in the medium category, the nurses' performance was in the unfavorable category. Based on the analysis of the two variables, it was identified that there was no relationship between the quality of work life with the performance of implementing nurses with a p value of 0.817. The work context dimension is a component that has a relationship with the performance of nurses implementing with p value 0.008, the dimension of work life does not significantly correlate with nurse performance. The conclusion of the research is that there is no relationship between the quality of work life and the performance of the implementing nurses. There is a relationship between the dimensions of the work context and the performance of the nurses. There is no relationship between the dimensions of work life and nurse performance.   Keywords: quality of work life, performance, implementers nurse


2020 ◽  
Vol 17 (6) ◽  
pp. 76-91
Author(s):  
E. D. Solozhentsev

The scientific problem of economics “Managing the quality of human life” is formulated on the basis of artificial intelligence, algebra of logic and logical-probabilistic calculus. Managing the quality of human life is represented by managing the processes of his treatment, training and decision making. Events in these processes and the corresponding logical variables relate to the behavior of a person, other persons and infrastructure. The processes of the quality of human life are modeled, analyzed and managed with the participation of the person himself. Scenarios and structural, logical and probabilistic models of managing the quality of human life are given. Special software for quality management is described. The relationship of human quality of life and the digital economy is examined. We consider the role of public opinion in the management of the “bottom” based on the synthesis of many studies on the management of the economics and the state. The bottom management is also feedback from the top management.


2018 ◽  
Vol 13 (Number 2) ◽  
pp. 67-77
Author(s):  
Anis Syamimi Abd Rahim ◽  
Mohd Norhasni Mohd Asaad

The purpose of this study is to review the implementation of ISO 9001:2015 in order to improve the quality of services at Pusat Kesihatan Universiti (PKU), Universiti Utara Malaysia. The respondents of this study were customers at the PKU, UUM. The questionnaire was distributed to 50 respondents. The data were analyzed using SPSS software version 24. The data were tested using descriptive statistics, and correlation analysis to answer the research questions and to achieve the objectives. The findings show that customers agree that implementation of ISO 9001:2015 give service at PKU, UUM is good and satisfied. Through the correlation test, the results showed that the relationship between the implementation of ISO 9001:2015 has a positive and significant impact on customer satisfaction and the effect of implementing ISO 9001:2015 has a positive and significant impact in improving quality of service at PKU, UUM.Through mean and standard deviation tests, results show that tangible dimensions are the main dimensions of customer satisfaction while dimensions with low values are dimensions of responsiveness.Therefore, all aspects of service in PKU, UUM will be strengthened and all aspects of the weaknesses could be addressed to improve the service in order to maintain good quality services.


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