Pressure Differential
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2021 ◽  
Vol 13 (3) ◽  
pp. 14-21
Yurii Buriennikov ◽  
Leonid Kozlov ◽  
Oana Rusu ◽  
Viktor Matviichuk ◽  

Mobile machine hydraulic circuits tend to adopt electrohydraulics. Such hydraulic circuits are based on controlled pumps, modulated hydraulics, sensors and controllers. This allows adapting the hydraulic circuit operating modes to the changes of external conditions of the machine operation. Application of hydraulic circuits with electrohydraulics in mobile machines allows to use mobile machines efficiently with a high number of removable endangers, increases their performance and improves the quality of performed works. The authors propose an adaptive hydraulic circuit for a mobile machine. The operation process in the adaptive hydraulic circuit in static and dynamic modes is determined by the interaction of the pump controller and pressure differential control valves. The hydraulic system operation stability, its fast response and readjustment are determined by the controller parameters. It has been revealed that the main parameters affecting the dynamic characteristics of the hydraulic system are: throttle area and coefficient of amplifying the pump controller orifice, dampener area and coefficient of amplifying the pressure differential control valve orifice. These parameters affect the stability, controlling and readjustment time in the hydraulic circuit differently. A functional including the values of controlling time , σ controlling and losses in the pump controller was used as an optimization criterion. The optimization has been made according to the developed mathematical model applying the method developed by I. Sobol and R. Statnikov. During the optimization each controller parameter changed on 3 levels. 81 tests were made and the best combination of controller parameters for the optimization criterion was determined. The following hydraulic circuit operation values were reached under the optimal values of parameters = 1.0·10-6 m2, = 1.0·10-3 m, = 1.2·10-6 m2, = 10·10-3 m: = 1.1 с, σ = 32 %, = 0.82 kW that comply with the requirements towards hydraulic circuits of mobile machines.

2021 ◽  
Jaime Orlando Castaneda ◽  
Almohannad Alhashboul ◽  
Amir Farzaneh ◽  
Mehran Sohrabi

Abstract CWI is affected by multiple factors, including the wettability of the rock. These experiments seek to determine the results that are obtained when CW is injected in a tertiary mode for systems: (1) wetted by water and (2) mixed wettability; to date, no study has used this approach. The same sandstone core was used in all trials, and each test consisted of saturating the core with live crude, followed by the injection of water as a secondary recovery and then the injection of CW as a tertiary recovery. An additional sensitivity test was conducted that consisted of varying the composition of the dissolved gas in the crude. In general, in a water wet system, the recovery associated with the injection of CW is higher (normalized) compared to a mixed wettability system. This does not mean that the results were negative in the mixed system. On the contrary, the results are positive since on the order of an additional 20% was recovered. However, the pressure differential in a mixed system is higher (14%) compared to water wet system. Although it is common knowledge that wettability of the rock affects the production and pressure results in an experiment, these are the first experiments that have been performed exclusively to determine quantitatively the response to CWI while maintaining the other parameters constant.

Prashant Unnikrishnan Nair

In real-world water injection applications, an in-line injection facilitates a pressure differential that boosts the current flow. A pressure differential created by the injection of a pressurized flow into the mainline of flow is derived from the momentum transfer equation. Heat loss is disregarded, and such empirical equations provide a ballpark value to these pressure differentials during the injection. In industrial applications, injection of the fluid is done on the surface, due to weld and other constraints where losses due to friction and eddy current formation are imminent. On the other hand, penetration injection provides a far more augmented pressure differential that has a polynomial impact based on the mainline flow rate and the injection flow rate. This paper aims to derive an accurate representation of the pressure differential values obtained from a penetration injection through experimentation and compare it against a surface injection or empirical calculation. The paper concludes by indicating that the penetration injection augments the pressure differential with a new empirical formula for the derived pressure differential as a polynomial equation for this apparatus and can be extended across different sizes of the mainline and injection line diameters. This work provides a precise formula that can be used to derive pressure differential and estimate the flow and pressure rates. The formula also provides a platform for further utility in the fracturing operations where fracture flow from the well upstream presents multiple injection fractures to the mainline through fracture pores.

2021 ◽  
Vol 13 (23) ◽  
pp. 13367
Angus Shiue ◽  
Ming-Jie Yin ◽  
Min-Hsuan Tsai ◽  
Shu-Mei Chang ◽  
Graham Leggett

In this study, Polyvinyl alcohol (PVA) blended with Polyethylene glycol (PEG), Monosodium glutamate (MSG) and Glutamic acid (GA) was cast on a reverse osmosis membrane to form a composite membrane. It is expected that the ether group can increase the CO2 affinity of the membrane. Sodium tetraborate (Borax) as a crosslinker can increase membrane basicity and glutamic acid (salt) can provide an enhanced transport mechanism, thereby improving the permeability and selectivity of carbon dioxide. FTIR spectra show that the thickness of coating is sufficiently low, while SEM results show that PVA-PEG series have a dense surface, and particles are observed on the surface of MSG/GA series. The gas permeance and separation performance of the composite membrane was tested using a single gas. Results showed that CO2 had higher permeance (GPU) at lower pressure differential. PEG with an ether group had the greatest effect on improving CO2 permeance and selectivity. However, MSG and GA with amine groups could not effectively improve CO2 selectivity due to solubility. The best coating solution was provided by PVA-PEG-1.2. The CO2 selectivity of the composite membrane was 10.05 with a pressure differential of 1.00 bar in a humid environment and no obvious deterioration was observed over a 10-day period. Borax can improve selectivity, water absorption, and thermal stability while avoiding the need for high temperature and long crosslinking time of aldehydes, which makes it possible to be used in a PVA carbon dioxide separation membrane.

2021 ◽  
Vol 2096 (1) ◽  
pp. 012041
A O Kharitonov ◽  
E B Bysigina ◽  
O A Nikitina

Abstract In operation the outcomes of study influencing an abrasive wear of working surfaces of a cylindrical nozzle on operation of a flow sensor of variable pressure differential are introduced. The outcomes are obtained by a numerical modelling of current of fluid through a nozzle. For a nozzle the internal cylindrical surface is resized up to a taper and circularization on radius a crimp on an input. Simulation executed by a finite element method with usage of the program Ansys 5.5ED. Budgeting of numerical experiment and treating of outcomes have fulfilled with applying of the program Stastistica 6.1.The quantitative estimation of influencing an abrasive wear on variation coefficient of the outflow of flow sensors is obtained.

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