Effect of the inlet gas volume fraction on the turbulent dissipation characteristics in the multiphase pump

The internal flow of the multiphase pump is complicated owing to its specific structure. To reveal the effect of the inlet gas volume fraction (IGVF) on the turbulent dissipation characteristics, the method of combining numerical simulation based on k-ε turbulence model with experiment was adopted, and the turbulent dissipation of the multiphase pump was quantitatively and qualitatively analyzed in both the pure water and gas-liquid two phases condition. Results showed the vortexes were primarily distributed in the diffusers at different inlet gas volume fractions (IGVFs), near the middle of the first diffuser and the outlet of the next diffuser. At the same time, the larger value of the turbulent dissipation than that in the impellers was concentrated in the inlet and outlet of the impellers and diffusers. In addition, the effect of IGVFs on the turbulent dissipation increased gradually from the hub to the shroud at the inlet section of the first impeller. Moreover, the turbulent dissipation became increasingly unsymmetrical from the hub to the shroud at the outlet section of the first impeller.

Automatic Air Volume Control System for Ventilation of Two Patients Using a Single Ventilator: A Large Animal Model Study

The COVID-19 pandemic outbreak led to a global ventilator shortage. Hence, different strategies to use a single ventilator to support multiple patients are considered. A mechatronic system Ventil divides and automatically controls gas volume pumped through two channels and was successfully validated in independent lung ventilation. We used Ventil in a series of experiments on a large animal model to verify its usability for ventilation in two patients using a single ventilator. The results of investigations on 12 pigs showed that the physiological level of respiratory parameters was maintained for 24 hours. Application of Ventil did not lead to injuries in the lungs, as indicated by CT scan analysis. We conclude that ventilation using Ventil can be considered safe in patients subjected to deep sedation without spontaneous breathing efforts.

Research of pressure pulsations during gas outlet to closed pipe area with liquid and installed disc barrier

A numerical simulation of the gas outflow to a closed region filled with liquid with a barrier disk was performed. The calculations were carried out using the VOF method, supplemented by the k-e turbulence model. Calculations were performed for three cases of 100, 200, and 300 mm distances of the disk from the injector with a gas outflow into water and liquid lead. The pulsations of axial pressure on a disk obstacle were investigated. It was found that the maximum pressure during pulsations of the upper gas volume in lead can be greater than the pressure in the gas receiver.

Effects on Lung Gas Volume, Respiratory Mechanics and Gas Exchange of a Closed-Circuit Suctioning System during Volume- and Pressure-Controlled Ventilation in ARDS Patients

Mechanically ventilated patients periodically require endotracheal suctioning. There are conflicting data regarding the loss of lung gas volume caused by the application of a negative pressure by closed-circuit suctioning. The aim of this study was to evaluate the effects of suctioning performed by a closed-circuit system in ARDS patients during volume- or pressure-controlled ventilation. In this prospective crossover-design study, 18 ARDS patients were ventilated under volume and pressure control applied in random order. Gas exchange, respiratory mechanics and EIT-derived end-expiratory lung volume (EELV) before the suctioning manoeuvre and after 5, 15 and 30 min were recorded. The tidal volume and respiratory rate were similar in both ventilation modes; in volume control, the EELV decreased by 31 ± 23 mL, 5 min after the suctioning, but it remained similar after 15 and 30 min; the oxygenation, PaCO2 and respiratory system elastance did not change. In the pressure control, 5 min after suctioning, EELV decreased by 35 (26–46) mL, the PaO2/FiO2 did not change, while PaCO2 increased by 5 and 30 min after suctioning (45 (40–51) vs. 48 (43–52) and 47 (42–54) mmHg, respectively). Our results suggest minimal clinical advantages when a closed system is used in volume-controlled compared to pressure-controlled ventilation.

PRODUKSI GAS HIDROGEN BERDASARKAN PENGARUH LUAS PENAMPANG TERHADAP KONSENTRASI LARUTAN ELEKTROLIT DAN SUPLAI ARUS DENGAN METODE ELEKTROLISIS

Pengembangan energi terbarukan menjadi fokus perhatian saat ini penggunaan sumber energi yang ramah lingkungan dan zero emission dengan pemanfaatan air untuk prosess pembuatan hidrogen melalui proses elektrolisis. Hidrogen adalah gas ringan (lebih ringan dari udara), tidak berwarna dan tidak berbau, jika terbakar tidak menunjukkan adanya nyala dan akan menghasilkan panas yang sangat tinggi, sehingga hidrogen mempunyai potensi yang sangat besar untuk dikembangkan sebagai sumber energi alternatif. Penelitian ini bertujuan untuk menganalisa pengaruh luas penampang dan konsentrasi larutan elektrolit dengan variasi suplai arus listrik terhadap produksi gas hidrogen dengan metode elektrolisis. Larutan elektrolit yang digunakan adalah larutan air garam (NaCl) dengan berlandaskan pada kadar salinitas air laut. Berdasarkan penelitian yang telah dilakukan membuktikan bahwa semakin tinggi konsentrasi larutan elektrolit , semakin besar luas penampang dan semakin tinggi arus yang disuplai maka volume gas yang dihasilkan akan semakin banyak. Hasil yang diperoleh yaitu volume gas H2 tertinggi pada konsentrasi salinitas 35 ppt , elektroda ukuran 0,5 in dan kuat arus 35 ampere sebesar 2,118693 liter gas H2 dalam waktu 120 detik. efisiensi tertinggi didapat pada ukuran elektroda 2,0 in ,salinitas 35 ppt dengan kuat arus 15 ampere nilai yang didapat 99,16% dan daya tertinggi dicapai pada 406 watt pada ukuran elektroda 2,0 in, salinitas 35 ppt pada kuat arus 35 ampere The development of renewable energy is currently the focus of attention on the use of environmentally friendly energy sources and zero emission by utilizing water for the hydrogen production process through the electrolysis process. Hydrogen is a light gas (lighter than air), colorless and odorless, if it burns it does not show a flame and will produce very high heat, so hydrogen has enormous potential to be developed as an alternative energy source. This study aims to analyze the effect of cross-sectional area and concentration of electrolyte solution with variations in the supply of electric current to the production of hydrogen gas by electrolysis method. The electrolyte solution used is a salt water solution (NaCl) based on the salinity of seawater. Based on the research that has been done, it is proven that the higher the concentration of the electrolyte solution, the greater the cross-sectional area and the higher the current supplied, the more gas volume will be produced. The result obtained is the highest H2 gas volume at salinity concentration of 35 ppt, electrode size of 0.5 inchi and current strength of 35 ampere of 2.118693 liters of H2 gas in 120 seconds. the highest efficiency is obtained at the electrode size of 2.0 inchi ,salinity 35 ppt with a current strength of 15 ampere the value obtained 99.16% and the highest power achieved at 406 Watts at the electrode size of 2.0 inchi, salinity 35 ppt at the current strength of 35 ampere

Physical Testing of a High-Speed Helico-Axial Pump for High-GVF Operation

High-speed rotordynamic pump operation for downhole or surface production is required and also beneficial to handle very high gas volume fraction (GVF) flows. Operating speeds of these pumps can be in excess of twice those of conventional pumps. This study presents results showing a high-speed helico-axial pump (HAP) can operate satisfactorily at intake GVFs up to 98%. The findings increase capabilities of field engineers and operators to boost and maximize production from high gas-content wells. The HAP tested had a housing outer diameter of 4.00-inch and operated at a rotational speed of 6000 revolutions per minutes (RPM). Air and water were the test fluids with the water volume flow rate held constant while the air volume flow rate was varied. The liquid and gas volume flow rates varied from 63 to 143 barrels per day (BPD), and 549 to 3238 BPD, respectively. Intake pressures varied from 14 to 76 psig, with average inlet temperature of 18°C. The corresponding discharge pressures and temperatures were recorded for each test point and observed for stable pump operation. The results showed that the HAP had stable operation during the tests for intake GVF range from 84% to 98%. Pump discharge pressures for this range of high intake GVF varied from 21 to 89 psig. The corresponding differential pressures across the HAP all had positive magnitudes indicating that at such high-speeds, the HAP was still able to add energy to the fluid even with the high gas content at intake. Analysis at fixed intake pressure with varying GVFs showed that the discharge-to-intake pressure ratio decreased with increasing intake GVF. For instance, at 33psig intake pressure, increasing the intake GVF from 84% to 94% decreased the discharge-to-intake pressure ratio from about 1.27 to 1.20, respectively. It was also observed that tightening the clearance between the impeller and diffuser of the HAP increased the discharge pressure compared to when the clearance was loose. Furthermore, ensuring the upstream flow is properly conditioned also improved the stable operation of the HAP. Overall and in conclusion, running a HAP at high speeds in addition to optimizing certain features of the HAP can result in stable pump operation and enhanced pressure boosting in high-GVF flows. This study mainly highlights the importance of operating HAPs at high speeds of up to 6000 RPM. Tightening clearances between rotordynamic components as well as tailored inlet flow conditioning are also additional features that enhance pressure boosting. This architecture opens up opportunities for field operators, and engineering personnel to maximize hydrocarbon production from their very high-gas content field assets, thereby increasing the economic bottomline for the stakeholders.

Multiple Application of Multi-Energy Gamma Ray Venture Type Multiphase Flowmeter in Giant Karachaganak Gas Condensate Field

The objective of this paper is to demonstrate multiple application of multi-energy gamma ray venture type multiphase flowmeter (MPFM) trial campaign in Karachaganak gas condensate giant carbonate field, operated by KPO B.V. The results of MPFM that was included into surface well test spread, to verify its performance, was compared against portable test separator and plant production testing facilities (control separator, flowmeters) and manual sampling results. MPFM from other vendors historically failed to deliver accurate production measurement mainly due to complexity of reservoir fluid in Karachaganak field. To ensure the MPFM considers this complexity, PVT samples were taken to provide laboratory data for PVT model of the MPFM to ensure sufficient quality of PVT data and compare against PVT model inside MPFM. First application of MPFM was during clean-up of the well prior handover well to production. Using MPFM helped to improve the quality during data acquisition. This information was critical for the well to be accepted by processing facility it is hooked-up to and to define optimal operating regime. Validation of BS&W, GOR and rates in unstable (foaming, carry over) and transient phase of production using MPFM has shown practical advantages. Another application was for water sampling loops to measure water cut and production rates. KPO has had challenges with inaccurate water cut measurement due to the limitations of existing test separators. A recent approach of performing fluid sampling (sampling loop) at the well head proved to be reliable source of measurements. In addition, the MPFM in combination with the test separator has been used to further improve the quality of the measurements of each phase. The third MPFM application had been with high gas-volume-fraction (HGVF) pumps, that helped to produce from low reservoir pressure, low GOR and high water cut wells. The operational range of HGVF pump was limited to maximum 75-80% of gas-volume-fraction (GVF). MPFM measures GVF in real-time to ensure HGVF pump operates in optimum operational range by managing the surface flow conditions. With current limitations of test separators in Karachaganak field and due to complexity of the gas-condensate fluid, the use of MPFM brings additional quality in the measurements (rates, water cut and GOR) which is crucial for field production optimization, reservoir management and short and long term forecasting.

Impact of effective microbes (em) bokashi supplementation on nutrients digestibility, rumen fermentation and gas volume production in diets of sheep

The present study was conducted to determine the appropriate type of by-products {sugar beet pulp (SBP), grape seeds (GS), olive cake (OC), citrus pulp (CtP), and jojoba meal (JM)} fermented with activated effective microorganisms (EM-Bokashi) to be integrated into the diet of sheep to obtain the best nutrient digestibility and rumen characteristic of Barki sheep. An in vitro experiment was carried out on five fistulated females for rumen fermentation activity, while 15 males were used for digestibility trials. Treatment with EM caused less cell wall content. GS and CtP had higher feed intake (FI) and digestibility coefficients; the lower was found for JM as well less FI. SBP and JM had a higher pH and NH3 concentration, while they were less for GS and CtP. Those had higher total volatile fatty acids (TVFA's) concentration, percentage of acetate, and acetic to propionic (A/P) ratio. JM had less acetate, A/P and higher propionate and butyrate. Higher gas volume after 24h fermentation was noticed for GS and CtP, they were higher kinetic parameters as well, but they were less methane production and more ME (MJ/kg DM), OMD (%) and microbial protein syntheses. Therefore, in conclusion, feeding Bokashi of GS or CtP to sheep can improve productivity, while using Bokashi of JM should be combined with other feeds.