Desalinations Systems with Renewable Energies
Neda Mehtari; Mostafa Kahani; Mohammad Zamen
Abstract
The current research focuses on the utilization of three waste water streams from a power plant located in southwestern Iran for desalination purposes and to prevent the waste of heat from the boiler blowdown stream while reducing carbon dioxide emissions by preheating the cooling water. Three different ...
Read More
The current research focuses on the utilization of three waste water streams from a power plant located in southwestern Iran for desalination purposes and to prevent the waste of heat from the boiler blowdown stream while reducing carbon dioxide emissions by preheating the cooling water. Three different scenarios are simulated using the Thermoflow-GT master 23 software, considering the conditions of power plant. The optimal values for the top brine temperature (TBT) of cooling water and the mass flow rate of the hot steam are selected by sensitivity analysis. The premier scenario consists of eight stages, with five stages dedicated to heat recovery (HGS) and three stages for heat rejection section (HRS). The optimal value for the TBT of cooling water is determined to be 90℃, the produced freshwater capacity in the desalination unit is found to be 1.69 kg/s, and the gain output ratio (GOR) of the system is about 3.60. The proposed unit requires 0.47 and 10.15 kg/s of hot steam and cooling water, respectively and the overall heat transfer coefficient is 2069.2 W/m2 ℃. In addition, the feasibility of utilizing a solar farm to generate the necessary thermal energy for the system is being evaluated.
Photovoltaic Systems
H. Eshghi; M. Kahani; M. Zamen
Abstract
The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their ...
Read More
The cooling process of photovoltaic (PV) panel is one the main issue in in the field of solar systems. The temperature of solar cells increases when solar radiation and also ambient temperature increase. Increasing the cell temperature reduces the electrical output power of the panels as well as their lifetime. To solve this problem, various methods have been provided for cooling the panels. One of these methods is the application of heat pipes. In this research, a PV panel equipped with thermosyphon heat pipe is introduced. The thermosyphon was connected to the back sheet of the panel to enhance the cooling effect of the PV system. Instead of using polyvinyl fluoride polymer, unlike conventional panels, an aluminum plate was used to connect the heat pipe to the back of the panel to have better cooling. In addition, to increase the heat transfer area between heat pipe and back surface of the panel, a special groove was drilled on the aluminum plate. Three different filling ratios (25, 45 and 65%) of distilled water as the working fluid were used in thermosyphon. The best performance of the systems was obtained at 45% of filling ratio, in which, the electrical power of the PV panel equipped with heat pipe was around 3.2% better than the conventional PV panel. In this case, 6.8 °C temperature difference was observed in the water tank connected to the condenser section of heat pipe which means that 54 kJ heat was transferred to the water in the tank.