جستجوی مقالات مرتبط با کلیدواژه « desalination » در نشریات گروه « مکانیک »

This study conducts a parametric analysis as well as performance evaluation of a multiuple effect distillation system equipped with a thermocompressor. Equations for mass, salt concentration, energy, and exergy for each component of the desalination system are established. The study proceeds with an investigation and analysis of this system using the EES (Engineering Equation Solver) software. This research examines the effects of Top Brine Temperature (TBT), water concentration, and the number of effects on the flow rate of the cooling water in the condenser, the flow rate of produced fresh water, the performance ratio, specific area, the rate of exergy destruction, and the efficiency of exergy. The findings show that the eight-stage desalination system achieves the highest performance ratio under specific system input conditions. Additionally, the exergy analysis reveals that the exergy destruction rates for the evaporators (effects), the condenser, the thermocompressor, and the pumps are 5146, 3266, 1568 and 366 kW respectively, with the highest to the lowest exergy destruction correspondingly attributed to the evaporators and the pumps.

In this paper, a new biomass multi-generation system based on micro-CCHP using an absorption refrigeration cycle and a desalination system, are presented to increase the performance of the basic cycle and to reduce the thermal wastes. A thermodynamic comprehensive modeling was done on the proposed system. also validation of subsystems and optimization of the system was done by genetic algorithm method with EES software. The results show that the dehumidifier has the highest exergy destruction among the other components of the system. The impact of the various system parameters such as; Evaprator1 temperature, Ammonia mass fraction, Absorber temperature, Difference temperature of heater, Generator1 pressure and heat source temperature is also done on the performance of the system. The parametric study show that by increasing the evaprator1 temperature, the energy efficiency of the system is increased. The maximum amount of energy and exergy efficiency of the system is 74.2% and 47.7%, respectively that occur at the 750-740 kelvin of heat source temperature. The energy and exergy efficiency of the base and MOOD case is 68.7% and 44.32%, 91.87% and 49.3%, respectively

The increasing population of the world, the change of style and the limited number of natural resources and energy all make freshwater industrial productions the main contenders for the cost-effective production of freshwater. In this research, the combination of combined cycle power plant (CCPP) using multiple effect distillation (MED) and reverse osmosis (RO) desiccation techniques is investigated through normal and advanced exergy, exergy-economic and exergy-environmental comprehensive analysis. First, CCPP thermodynamic modeling is done using mathematical programming method. Then, a mathematical model is presented to integrate the existing CCPP with MED and RO desalination plants. Finally, the aforementioned normal and advanced analyzes are performed to evaluate the main performance parameters of the integrated CCPP system and MED-RO desalination system, and to identify potential technical, economic, and environmental improvements. A case study is also presented about the Shahid Salimi Neka power plant located in the north of Iran along the Caspian Sea.The mathematical modeling method for this integrated system is solved in "MATLAB" program and its results are validated by "Thermoflex" software. The results show a 3.79% increase in fuel consumption after combining CCPP and water desalination facilities. The exergy efficiency of the advanced system is 42.7% and the highest combustion chamber exergy destruction cost is $1.09 per second. Economic and environmental analyzes of the integrated system also show that gas turbines have the highest investment cost ($0.047 per second). At the same time, the MED system has the highest environmental impact rate, i.e. 0.025 points per second.

Population growth and freshwater scarcity have led people to think about renewable energy sources. In this research, a stepped solar still has been used to produce drinking water. In order to improve the device's performance, absorbent fabrics were utilised to increase the heat transfer area between the saline water and the environment, resulting in increased evaporation and fresh water production. Water inlet flow rate, fabric material, fabric thickness or number of layers, fabric colour, and fabric placement angle are all variables that have been used at the same time. Three different fabrics in three different layers were used in the experiments, with flow rates of 50, 100, and 150 ml/min and angles of 30, 60, and 90 degrees. There were also three colours for fabrics: white, brown, and black. The response level approach was used for the design of the experiments in this study, and 27 experiments were examined. The findings revealed that the black color, material # 1 with the highest water absorption, more layers, larger angles of fabrics, and lowering the flow rate all had an effect on increasing the amount of fresh water produced.

The air humidification-dehumidification method is a good option for decentralized freshwater production because of no need for high temperature operation. The main disadvantage of these systems is their dependence on direct sunlight. to solve this problem, using the sun's thermal energy storage during the day and using this energy during the night can be a very good option that can be achieved using phase change materials. In the present work, it is also possible to continue the desalination process after sunset, by equipping the solar collector with phase change material from two different types of paraffin wax. MATLAB software has been used to solve the equations governing the components of the desalination system. According to the results, the temperature of the output water from the solar collector plays a significant role in the amount of fresh water produced. The results also confirm that the use of phase change material leads to more than 9% increase in fresh water production. Another important result is that in the phase change materials the melting process speed is substantially higher than the freezing process speed.

Among desalination systems, the use of reverse osmosis has become very widespread due to its advantages. One of the challenges in desalination systems especially in the reverse osmosis method is the existence of a control algorithm to overcome the uncertainties and disturbances. Another challenge of such systems is their power supply. A high-pressure pump supplies the pressure behind the membrane in the reverse osmosis system. The use of renewable energy not only does not have any environmental effects but also provides sustainable energy for such systems. In this paper, to answer these two challenges, at first, the integrated model of the reverse osmosis desalination system with the solar photovoltaic system has been examined; then for each part, a control algorithm is designed and simulated. An optimized fuzzy controller has been designed to track the maximum power point at different temperatures and radiation conditions in the photovoltaic solar system. The fuzzy controller has been optimized with the invasive weed optimization algorithm. The electric motor has been controlled using a fuzzy proportional–integral–derivative algorithm. The super-twisting sliding mode control has been used for the reverse osmosis system. The simulation results show that the proposed algorithm for the combined reverse osmosis-photovoltaic system has a good performance in different operating conditions and can remove and eliminate disturbances on the system.

The design and optimization of multiple production systems, including systems that simultaneously generate heat, power and freshwater, play an important role in improving the performance of these systems. In this study, after modeling a multi-effect evaporative desalination system MED and simultaneous heat and power generation CHP, they are combined to meet the demand for heating, power and fresh water for a hotel. The purpose of this study is the thermoeconomic evaluation of the use of thermal energy storage TES tank in the combined system CHP + MED compared to the non-use of this tank. The strategy is applied every 24 hours of the two seasons. In optimizing this system, the annual cost minimization has been done as a objective function and using genetic algorithm. Optimal technical results in these systems show that the system CHP + MED + TES requires a gas turbine with a nominal capacity of 12% larger and a backup boiler with a nominal capacity of 7.14% smaller than the system CHP + MED. The optimal results of the economic comparison show that by using the thermal energy storage tank in the combined system CHP + MED, the annual cost is improved by 4.91%.

In the present study, an energy production system using two types of renewable solar and wind energy with climatic conditions and close to areas with high potential for the system under study, with suitable conditions in terms of wind speed and solar radiation as energy sources, We act. To use the heat from the solar system with a parabolic-linear collector, a steam cycle is designed to which heat is transferred through an evaporator and generated electrical energy by a steam turbine. The heat remaining after the evaporator was used to generate a single-effect absorption refrigeration system to generate a cooling load. The main components of the system consist of an organic Rankine cycle, steam Rankine cycle, thermoelectric, absorption refrigeration system, reverse osmosis, wind turbine and a parabolic-linear solar collector. EES software has been used as an engineering tool to model the system and obtain thermodynamic results. The results showed that due to the increase in solar radiation intensity and wind energy on the total exergy, the freshwater production output of the multiple production system is effective and increases the system output. According to the results, solar energy with the central receiver has the highest amount of exergy destruction. Also, the results of exergy degradation showed that the solar system with 60% and wind turbine with 17% have the highest amount of exergy degradation in the system components.

In gas power plants, a lot of energy is lost in the form of heat more than the electricity produced. In the present research, techno-economic evaluation of combined power, desalination and cooling systems running by the exhaust flue gases of a gas turbine in Iran is performed. In addition to using power generated by the gas turbine, attempts were made to use Organic Rankine Cycle to recover the heat dissipated from gas turbine in order to reproduce power. In fact, choosing the appropriate technology for the combined system of simultaneous production of power, fresh water and cooling based on energy and economic analysis is investigated. Results showed that multiple-effect distillation system with fresh water price of 1 $ per m3 should be used in order to produce high tonnage fresh water, and to achieve the proper price of fresh water, Reverse Osmosis by giving priority to ORC power, and then, GT application is suggested. According to the calculated price of power sale, the sale of gas turbine power is approximately 0.1 $ per kW/h. Regarding cooling systems, the results showed that the absorption system has a lower initial cost and produces a greater cooling load than the compression system, and if necessary, the compression cooling system can be used only to achieve very low temperatures.