Engineering Journal (Faculty of Engineering, Chulalongkorn University, Bangkok)
Not a member yet
1223 research outputs found
Sort by
Phenolic Wastewater Treatment Using Activated Carbon in a Three Phase Fluidized-Bed Reactor
Full text linkPhenolic wastewater treatment was investigated using activated carbon in a lab scale three phase fluidized-bed reactor. The reactor with effective volume of 272 ml, 300 mm in height and 40 mm in diameter was made from transparent acrylic that allowed to observe the phenomena occurring inside. Phenol 10 mg/l and air were used as representative agents that were continuously fed to the reactor at a constant flow rate of 1 and 2 l/min with co-current and up-flow, respectively. Comparison of the phenolic adsorption under five different conditions: (a) fresh Acs, (b) 1st reused Acs, (c) fresh Fe/Acs, (d) 1st reused Fe/Acs, and (e) 2nd reused Fe/Acs, have been carried out. The phenolic wastewater was re-circulated through the reactor and its concentration was measured with respect to time. The experimental adsorption results revealed that both fresh Acs and Fe/Acs gave the better results than reused Acs and reused Fe/Acs, respectively. The adsorption in all cases of Acs and Fe/Acs would follow Pseudo-second order kinetic
Finite Element Method for Analysis of Conjugate Heat Transfer between Solid and Unsteady Viscous Flow
Full text linkA fractional four-step finite element method for analyzing conjugate heat transfer between solid and unsteady viscous flow is presented. The second-order semi-implicit Crank-Nicolson scheme is used for time integration and the resulting nonlinear equations are linearized without losing the overall time accuracy. The streamline upwind Petrov-Galerkin method (SUPG) is applied for the weighted formulation of the Navier-Stokes equations. The method uses a three-node triangular element with equal-order interpolation functions for all the variables of the velocity components, the pressure and the temperature. The main advantage of the method presented is to consistently couple heat transfer along the fluid-solid interface. Four test cases, which are the lid-driven cavity flow, natural convection in a square cavity, transient flow over a heated circular cylinder and forced convection cooling across rectangular blocks, are selected to evaluate the efficiency of the method presented
Determination of Allowable Capacity of Distributed Generation with Protection Coordination Consideration
Full text linkThe presence of distributed generation (DG) provides considerable benefits from both engineering and economic viewpoints. However, it changes radial configuration of the distribution feeders. Consequently it may cause coordination failure to existing protection system which is originally set based on radial configuration. In addition, high penetration level of DG may increase feeder loss, and cause system voltage profile out of a required range. This paper presents an optimization based method to calculate maximum allowable capacity of a DG considering a set of constraints formulated to maintain protection system coordination. In addition feeder loss and system voltage constraints are also taken into account. With the developed methodology, the maximum DG capacity which does not provide adverse effects to the existing system, i.e. violate protection coordination, increase feeder loss, and cause voltage violation, can be obtained