Mohamed A. Teamah

Simulation of Liquefied Petroleum Gas (LPG) Production from Natural Gas Using Fractionation Towers

Liquefied petroleum gas (LPG) is used as a fuel in several applications, it can replace diesel and petrol. (LPG) is also filled in cylinders, and used as cooking fuel for households, this is why the price of (LPG) increased over the last few years. This paper focuses on the design and simulation of (LPG) plant in order to decrease the heat consumption in (kW) by each fractionation tower during fractionation. Simulation consists of four fractionation towers and is done by using Aspen HYSYS software. Results showed that the recommended inlet feed tray is at the middle of the tower, to provide enough space to occur heat transfer between descending liquid from the condenser and ascending vapor from the reboiler. Simulation showed that the 9 th trays for feed inlet to depropanizer is the proper location for this study giving optimum results. Also operating the tower at lower pressures is recommended if it will not affect the boiling point of the desired component to be separated, where the lowest heat duties were consumed at lowest reboiler pressures.

Numerical Investigation of a Three-Dimensional Laminar Mixed Convection Flows in Lid-Driven Cavity for Very Small Richardson Numbers

Laminar mixed convection in a three-dimensional lid driven cavity is numerically investigated. The top lid of the cavity is moving rightwards with a constant speed at a cold temperature. The bottom wall is maintained at an isothermal hot temperature, while the other vertical walls of the cavity are assumed to be insulated. In this study the mass diffusion was not taken into account and the fluid used was air. The flow and heat transfer behavior is studied for various Richardson number ranging from 5 × 10−5 to 3 × 10−4 at a fixed Prandtl number of 0.71 through analyzing the local Nusselt number distribution at different sections inside the cavity. Lewis number Le is assumed to be unity and the buoyancy ratio parameter N is equal to zero. Computations were done using an in-house code based on a finite volume method. The results showed a good agreement with previous two dimensional studies, while the three dimensional study gives different results at different sections inside the cavity. It is observed that, the average Nusselt number “Av Nu” on top and bottom surfaces decreases for all sections inside the cavity with increasing Richardson number. A correlation was formulated for each section on both walls for “Av Nu” as a function of “Ri” with a maximum error of 7.3%.Copyright

Experimental Study of a Water Desalination System Based on Humidification-Dehumidification Process Using a Heat Pump

In this paper an experimental investigation on a lab scale HDH water desalination unit using a Heat pump was presented. From the thermodynamic view, it was found that the electric heater has a coefficient of performance equal unity, while the heat pump has a coefficient of performance greater than one; in other words the dissipated heat has a high scale. In addition, the refrigeration effect could be used as a secondary benefit. The proposed system utilizes the heat rejected and the cooling effect of the mechanically driven vapor compression heat pump for fresh water production. A test rig consisting of a fan, condenser duct, water spray humidifier and evaporator duct was constructed to study the performance under different operating conditions. The effect of air flow rate variation and water spraying direction (cross, counter or parallel) in the humidification process were studied. Experiments were carried out under variable inlet air conditions. Air flow rate was varied from 0.076 m3/s to 0.4054 m3/s. Results showed that cross water spraying humidification tests yielded the highest production rate. The unit’s maximum production rate was found to be 2.8 Liters/hour at a power 1.4091 kW.Copyright