Calculation of thermal loads of buildings adapted for cooling in summer and heating in winter is important for the accuracy of the design and the appropriate choice of equipment for the adaptation of air and air handling units in order to meet the requirements of operation, thermal comfort and good distribution of air in the adapted place. This paper presents some consideration of cooling load calculation techniques. The numerical calculations are performed for a certain building in Basra, which is located on a longitude of 47.78 ° and N 32 latitude with two floors.
Small modular reactors (SMRs) represent a key area of interest to nuclear industry developers, which have been making significant progress during the past few years. Generally, these reactors are promising owing to their improved safety due to passive systems, enhanced containment efficiency, and fewer capital costs in comparison to traditional nuclear reactors. An important advantage of SMRs is their adaptability in being coupled to other energy-consuming systems, such as desalination plants (DPs) to create a cogeneration plant. Considering the serious challenges regarding the freshwater shortage in many regions of the world and the necessity of using low-carbon energy sources, it is advantageous to use SMR for supplying the required heat and electricity of DPs. As a high-performance desalination technology, the hybrid desalination (HD) systems can be exploited, which retain the advantages of both thermal and membrane desalination methods. In this study, several SMR coupling schemes to HD plants have been suggested. In performing a thermodynamic analysis of integrated SMR-DP, the International Atomic Energy Agency (IAEA) Desalination Thermodynamic Optimization Program (DE-TOP) has been utilized. It has been found that the use of relatively hot water from the SMR condenser leads to about 6.5 to 7.5% of total desalination cost reduction, where the produced electricity and hot steam extracted from low-pressure turbine were used to drive the HD system.
31 December 2018 in IOP Conference Series: Materials Science and Engineering
Grate coolers which represent one of the pyro-processing units are extensively used in cement industries. The essential function of grate coolers is a waste heat recovery from hot clinker which leaves the rotary kiln. This paper presents an analysis of energy and exergy based on the clinker temperature profile. It focuses on the distributions of temperature, energy and exergy for cooling air and hot clinker along the grate cooler in cement industries. Consequently, this distribution allows predicting the temperatures of secondary air, tertiary air, and exhaust air, which will lead to estimation of waste heat recovery from the clinker cooler system.
18 June 2017 in Numerical Heat Transfer, Part A: Applications
To explore the mechanism of flow boiling in microchannels, the processes of a single-vapor bubble evaporating and two lateral bubbles merging in a 2D microchannel are investigated. The temperature recovery model based on volume of fluid method is adopted to perform the flow boiling phenomena. The effects of wall superheat, Reynolds number, contact angle, surface tension, and two-bubble merger on heat transfer are discussed. Wall superheat dominates the bubble growth and is roughly proportional to wall heat flux. The update of velocity and temperature fields’ distribution in the channel increases with increasing inflow Reynolds number, which improves the wall heat flux markedly. Besides, the area of thin liquid film between the wall and the bubble is enlarged by reducing the contact angle, thus, expanding the wall heat flux several times compared with the single-phase cross section. However, variation of surface tension (0.0589, 0.1 N/m) is found to be insignificant.
Nowadays, several technologies for desalination processes are available and widely employed. However, they consume a considerable amount of energy and involve high capital and operating costs. Therefore, the techno-economic analysis of a system coupling different energy sources with the desalination processes is of value. The possibility of coupling a small gas turbine combined heat and power system (GT CHP) with hybrid desalination plants (HDPs) has been assessed in this study. The proposed gas turbine power generation system, based on a single-stage centrifugal compressor and an uncooled centripetal turbine, provides design simplicity and reasonable installation costs for the power generating plant. The hybrid desalination technique, based on the use of two different desalination technologies, i.e., Reverse Osmosis (RO) and a thermal desalination process, has been chosen to better exploit the electrical and thermal energy produced by the mini CHP plant. The proposed solution is numerically investigated from both thermodynamic and economic points of view, and the results of the thermodynamic analysis of the cycle are used as input for the evaluation of the amount of freshwater produced and of costs. The economic assessment of standalone desalination systems is also shown for the comparison with the hybrid solutions here proposed. Results show that the total cost of the water produced by MED + RO was less than the total cost of the water obtained by MSF + RO, and that the energy cost of MED + RO hybrid desalination system was about 15% less than that for stand-alone RO desalination technology. Thus, the MED + RO hybrid desalination system can be considered a promising solution for the coupling with the proposed mini GT CHP plant, which, due to the small size and cost, as well as the easy installation, can be easily applied in off-grid or remote areas.