Entity

Time filter

Source Type


Mohammad A.Th.,National University of Malaysia | Mohammad A.Th.,Baqubah Technical Institute | Mat S.B.,National University of Malaysia | Sulaiman M.Y.,National University of Malaysia | And 2 more authors.
Energy Conversion and Management | Year: 2013

In the current paper, an artificial neural network (ANN) model for predicting the performance of a liquid desiccant dehumidifier in terms of the water condensation rate and dehumidifier effectiveness is proposed. Six air and desiccant inlet parameters were used as inputs for the ANN. To determine the performance of the ANN technique for predicting the performance of the dehumidifier, actual experimental test data were obtained from a previous study, that tested a packed column dehumidifier with a total height of 0.6 m and a specific packing material surface area of 77 m2/m3, using triethylene glycol as the desiccant. In the experiment, 54 data samples were used in a series of runs. MATLAB code was designed to study feed forward back propagation with traingdm, learngdm, MSE, and tansig as the training, learning, performance, and transfer functions, respectively. Up to 70% of the experimental data was used to train the model; the remaining 30% was used to test the output. The results show that the 6-3-3-1 network structure was the best model for predicting water condensation rate, whereas the 6-6-6-1 network structure was the best model for predicting dehumidifier effectiveness. The maximum percentage difference between the ANN and experimental value for water condensation rate and dehumidifier effectiveness were 8.13% and 9.0485%, respectively. The model for the water condensation rate and dehumidifier effectiveness could be further improved by modifying the number of hidden layers. © 2012 Elsevier Ltd. All rights reserved. Source


Mohammad A.T.,National University of Malaysia | Mohammad A.T.,Baqubah Technical Institute | Bin Mat S.,National University of Malaysia | Sulaiman M.Y.,National University of Malaysia | And 2 more authors.
Renewable and Sustainable Energy Reviews | Year: 2013

This paper reviews and surveys the available hybrid liquid-desiccant air-conditioning system technologies. These technologies are proposed as alternative to the traditional vapor-compression systems because of its advantages in removing air latent load, environment-friendly feature, ability to remove pollutants from the processed air, and ability to reduce electrical energy consumption. This paper first introduces the traditional air-conditioning system: vapor compression, vapor absorption, and evaporative cooling. In addition, the principles of liquid desiccants and liquid-desiccant dehumidification systems and the hybrid liquid-desiccant classifications are discussed. Next, combination of the liquid-desiccant systems with vapor compression, vapor absorption, and direct and indirect evaporative cooling units are outlined. Finally, conclusions and some important suggestions are presented based on the collected information. © 2012 Elsevier Ltd. Source


Mohammad A.T.,National University of Malaysia | Mohammad A.T.,Baqubah Technical Institute | Mat S.B.,National University of Malaysia | Sulaiman M.Y.,National University of Malaysia | And 2 more authors.
Energy and Buildings | Year: 2013

In hot and humid areas, the liquid desiccant air-conditioning systems based on evaporative cooling was proposed as an alternative to the traditional vapor compression systems due to its advantage in, removing the air latent load, friendly environment, removing of pollutants from the process air and reduction of the electrical energy. This paper briefly surveys the recent researches and development activities in liquid desiccant dehumidification systems combined with evaporative cooling technologies. A basic description of the principle operation for liquid desiccants and classification of hybrid liquid desiccant systems is given first. Next, liquid desiccant dehumidification systems are included. Finally, hybrid liquid desiccant with direct evaporative and indirect evaporative cooling systems are discussed. © 2013 Elsevier B.V. All rights reserved. Source


Mohammad A.T.,National University of Malaysia | Mohammad A.T.,Baqubah Technical Institute | Mat S.B.,National University of Malaysia | Sulaiman M.Y.,National University of Malaysia | And 2 more authors.
Energy and Buildings | Year: 2013

Abstract Conventional air conditioning systems based on the vapor compression principle are primary electricity consumers and their refrigerants have negative environmental impacts. The combined liquid desiccant dehumidification and vapor compression system, defined as hybrid liquid desiccant systems, was studied extensively to improve the performance of these systems. Different configurations of hybrid liquid desiccant systems and their components were investigated. This paper reviews and surveys the available hybrid liquid desiccant air conditioning system technologies. Relevant information about the system characteristics, configurations, and performances are covered and presented in detail. Finally, conclusions and some important suggestions are presented according to the collected information about the systems. Source


Al-Abidi A.,Sanaa Community College | Mat S.,National University of Malaysia | Sopian K.,National University of Malaysia | Sulaiman Y.,National University of Malaysia | Mohammad A.,Baqubah Technical Institute
Heat Transfer Engineering | Year: 2015

Thermal energy storage is critical for reducing the discrepancy between energy supply and energy demand, as well as for improving the efficiency of solar thermal energy systems. Among the different types of thermal energy storage, phase-change materials (PCM) thermal energy storage has gained significant attention recently because of its high energy density per unit mass/volume at nearly constant temperature. This study experimentally investigates the using of a triplex tube heat exchanger (TTHX) with PCM in the middle tube as the thermal energy storage to power a liquid desiccant air-conditioning system. Four longitudinal fins were welded to each of the inner and middle tubes as a heat transfer enhancement in the TTHX to improve the thermal performance of the thermal energy storage. The average temperature of the PCM during the melting process in the TTHX with and without fins was compared. The PCM temperature gradients in the angular direction were analyzed to study the effect of the natural convection in the melting process of the thermal storage. The energy storage efficiency of the TTHX was determined. Results indicated that there was a considerable enhancement in the melting rate by using fins in the TTHX thermal storage. The PCM melting time is reduced to 86% by increasing of the inlet heat transfer fluid. The average heat storage efficiency calculated from experimental data for all the PCMs is 71.8%, meaning that 28.2% of the heat actually was lost. 2016 Copyright © Taylor and Francis Group, LLC Source

Discover hidden collaborations