scholarly journals High Pressure Injection of Chemicals in a Gravel Beach

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 525
Author(s):  
Geng ◽  
Abdollahi-Nasab ◽  
An ◽  
Chen ◽  
Lee ◽  
...  
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Lithium Bromide ◽  
Injection Pressure ◽  
Tidal Range ◽  
Application Of Surfactants ◽  
Pressure Injection ◽  
Oil Biodegradation ◽  
High Pressure Injection ◽  
Gravel Beach

The remediation of beaches contaminated with oil includes the application of surfactants and/or the application of amendments to enhance oil biodegradation (i.e., bioremediation). This study focused on evaluating the practicability of the high pressure injection (HPI) of dissolved chemicals into the subsurface of a lentic Alaskan beach subjected to a 5 m tidal range. A conservative tracer, lithium, in a lithium bromide (LiBr) solution, was injected into the beach at 1.0 m depth near the mid-tide line. The flow rate was varied between 1.0 and 1.5 L/min, and the resulting injection pressure varied between 3 m and 6 m of water. The concentration of the injected tracer was measured from four surrounding monitoring wells at multiple depths. The HPI associated with a flow rate of 1.5 L/min resulted in a Darcy flux in the cross-shore direction at 1.15 × 10−5 m/s compared to that of 7.5 × 10−6 m/s under normal conditions. The HPI, thus, enhanced the hydraulic conveyance of the beach. The results revealed that the tracer plume dispersed an area of ~12 m2 within 24 h. These results suggest that deep injection of solutions into a gravel beach is a viable approach for remediating beaches.

scholarly journals Exhaust Gas Characteristics According to the Injection Conditions in Diesel and DME Engines

2019 ◽  
Vol 9 (4) ◽  
pp. 647 ◽  
Author(s):  
Seamoon Yang ◽  
Changhee Lee
Keyword(s):  
High Pressure ◽  
Injection Pressure ◽  
Common Rail ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Pressure Injection ◽  
High Pressure Injection

In this paper, the effect of high-pressure injection pressure on particulate matter (PM) and nitrogen oxide (NOx) emissions is discussed. Many studies have been conducted by active researchers on high-pressure engines; however, the problem of reducing PM and NOx emissions is still not solved. Therefore, in the existing diesel (compression ignition) engines, the common rail high-pressure injection system has limitations in reducing PM and NOx emissions. Accordingly, to solve the exhaust gas emission problem of a compression ignition engine, a compression ignition engine using an alternative fuel is discussed. This study was conducted to optimize the dimethyl ether (DME) engine system, which can satisfy the emission gas exhaust requirements that cannot be satisfied by the current common rail diesel compression ignition engine in terms of efficiency and exhaust gas using DME common rail compression ignition engine. Based on the results of this study on diesel and DME engines under common rail conditions, the changes in engine performance and emission characteristics of exhaust gases with respect to the injection pressure and injection rate were examined. The emission characteristics of NOx, hydrocarbons, and carbon monoxide (CO) emissions were affected by the injection pressure of pilot injection. Under these conditions, the exhaust gas characteristics were optimized when the pilot injection period and needle lift were varied.

Implicit Numerical Model of a High-Pressure Injection System

1992 ◽  
Vol 114 (3) ◽  
pp. 534-543 ◽  
Author(s):  
A. E. Catania ◽  
C. Dongiovanni ◽  
A. Mittica
Keyword(s):  
High Pressure ◽  
Differential Equations ◽  
Gaussian Elimination ◽  
Injection Pressure ◽  
Injection System ◽  
Algebraic Equations ◽  
Two Phase ◽  
Boundary Shear ◽  
Pressure Injection ◽  
High Pressure Injection

An implicit finite-difference numerical method has been developed and applied to the simulation of unsteady flow phenomena in a high-pressure injection system. A first-order one-step BSBT (backward space, backward time) scheme was used to obtain the difference analogue of the one-dimensional, elemental-volume averaged, partial differential equations governing the pressure-pipe flow. Second and higher-order implicit difference representations were employed for the ordinary differential equations simulating the pump and injector dynamics. The resultant nonlinear algebraic equations were solved by the Newton-Raphson method and a fast modified version of the Gaussian elimination procedure was used to solve the linearized equations. This was an extension of the Thomas solver to a multidiagonal system of algebraic equations. A compact, efficient and stable numerical algorithm was so obtained. The mathematical model takes into account the compressibility of the liquid fuel, the boundary shear, and also includes the simulation of possible cavitation occurrence at one or multiple locations in the injection system. No artificial viscosity has to be added to the solution in the vicinity of discontinuities induced by cavitation in the flow properties. The cavitation simulation is based on a simple mixture model of transient two-phase flow in pipes and can incorporate the effects of gaseous cavitation occurrence. Experimental values of the flow coefficients were used for the pump and injector and, for the latter, the dependence of the discharge coefficients on the needle lift and injection pressure was also taken into account. The model was tested and validated by comparing the numerical results with those of experiments carried out at the Fiat Research Center on a diesel-engine inline injection system, with a jerk-pump and an orifice type nozzle-injector.

Effect of Regulation Valves Installation in High Pressure Injection System Pipelines on the Formation of Reactor Vessel Thermal Stress Conditions

2014 ◽  
Author(s):  
Aleksander Mazurok ◽  
Maksym Vyshemirskyi
Keyword(s):  
High Pressure ◽  
Thermal Stress ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Stress Conditions ◽  
Severe Accident ◽  
Injection System ◽  
Pressure Injection ◽  
Cooling Water Flow Rate ◽  
High Pressure Injection

Effect of regulation valves (RV) installation in high pressure injection system (HPIS) pipelines on the formation of reactor pressure vessel (RPV) thermal stress conditions was analyzed. Modernization is implemented at South-Ukrainian nuclear power plant (SUNPP) Unit 1 within the framework of life extension, which finished by the end of 2013. The main goal of the modernization is to expand the HPIS functionality for small leak accident and protection against the cold overpressurization due to flow rate and primary pressure effectively regulation. The thermal hydraulic model for RELAP5/mod3.2 code with detailed downcomer (DC) model and changes in accordance with modernization was used for calculations. Detailed (realistic) modeling of piping and equipment was performed. Also, an algorithm for the RVs was developed. Applying of cooling water flow rate regulation avoids excessive primary cooling and, consequently, helps to preserve the RPV integrity and to prevent reaching through crack formation, which can lead to a severe accident.

A Numerical Investigation on Mixing Characteristics of Natural Gas Jets With High-Pressure Injection

2021 ◽  
Author(s):  
Long Liu ◽  
Tianyang Dai ◽  
Qian Xiong ◽  
Yuehua Qian ◽  
Bo Liu
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Air Entrainment ◽  
Gas Jet ◽  
Swirl Ratio ◽  
Marine Engine ◽  
Low Speed ◽  
Pressure Injection ◽  
Mixing Characteristics ◽  
High Pressure Injection

Abstract With increasingly stringent emissions limitation of greenhouse gas and atmospheric pollutants for ship, the direct injection of natural gas on the cylinder head with high-pressure injection is an effective method to make a high power output and decrease harmful gas emissions in marine natural gas dual fuel engines. However, the effects on mixing characteristics of high-pressure natural gas underexpanded jet have not been fully understood. Especially, the injection pressure is up to 30 MPa with large injection quantity and critical surrounding gas conditions for the low-speed two-stroke marine engine. Therefore, this research is focused on the flow and mixing process of the natural gas jet with high-pressure injection under the in-cylinder conditions of low-speed two-stroke marine engine. The gas jet penetration, the distribution of velocity and density, the equivalence ratio and air entrainment have been analyzed under different nozzle hole diameters by numerical simulation. The effects of surrounding gas conditions including pressure, temperature and swirl ratio on air entrainment and equivalence ratio distribution were studied in detail. From the numerical simulation, it is found that the mixing characteristics of natural gas jet can be improved under in-cylinder conditions of higher ambient temperature and swirl ratio, which is relevant to the low-speed two-stroke marine engine.

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