The purpose of this research is to investigate thermoeconomic optimization and exergy analysis of transcritical CO2 refrigeration cycle with an ejector. After modeling thermodynamic equations of elements and considering optimization parameters of emerging temperature of gas of cooler (Tgc) , emerging pressure of cooler's gas (Pgc) , and eva...

ABSTRACT Stringent NOx and particulate emission constraints require high levels of exhaust gas recirculation. In this paper we model and analyze a Variable Valve Timing methodology that in steady-state achieves large levels of internal Exhaust Gas Recirculation (iEGR) or residual charge in Compression Ignition Direct Injection (CIDI) engines. Current external Exhaust Gas Recirculation (eEGR) te...

The purpose of this research is to investigate thermoeconomic optimization and exergy analysis of transcritical CO2 refrigeration cycle with an ejector. After modeling thermodynamic equations of elements and considering optimization parameters of emerging temperature of gas of cooler (Tgc) , emerging pressure of cooler's gas (Pgc) , and eva...

Pipelines are pressure vessels. Their enviable safety record compares weil with other transportation modes. Typical pipeline fatality rates are about 1% those of rail or air which are, in turn, about 1% of highway fatalities. Pipeline safety is first assured by rigorous inspection during pipe manufacture and line construction. All welds are inspected using radiography to detect voids and ultras...

cementing is an essential part of every drilling operation. protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. failure in this task results in catastrophic events, such as blow outs. hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phe...

.hot metal gas forming of tubes can be used in various industries such as automotive and aerospace industries. in this process tube is formed at elevated temperatures, by using gas instead of fluid pressure. lower required pressure and low power are its advantages in comparison to hydroforming process. in this paper, a hot metal gas bulging process of an aluminum alloy tube has been investigate...

In this study, mass transfer coefficients (MTC’s) of natural gas components during hydrate formation are reported. This work is based on the assumption that the transport of gas molecules from gas phase to aqueous phase is dominant among other resistances. Several experiments were conducted on a mixture of natural gas at different pressures and temperatures and the consumed gas was monitored an...

Cryotherapy machines, also known as cryosurgery machines, continue to be widely used for surgical procedures of the eye such as retinal detachment repair, cataract extraction, glaucoma and so on. Cryotherapy machines (Figure 1) control the release of a compressed gas, stored under high pressure in a cylinder. When the foot pedal is depressed, the gas is regulated to a lower working pressure and...