جستجوی مقالات مرتبط با کلیدواژه "reverse osmosis" در نشریات گروه "مکانیک"

Today, the production of fresh water using reverse osmosis method is the affordable options in many countries. One of the problems of this method is the reduction of the amount of permeate water due to increase of salinity and temperature of raw water throughout the year. In this article, a method for redesigning the hydraulic turbocharger rotor has been discussed so that the amount of permeate water can be kept relatively constant without. For this purpose, firstly, the performance of a working plant was investigated, then using computational fluid dynamics and similarity relations in turbomachinery, two new rotors were designed and manufactured for the existing turbocharger to be used in two modes of high and low membrane pressure. To verify the validity, the design parameters have been compared with the test data. The results show that despite the change in the membrane, replacing new rotors The new rotor design has made the water production unchanged. The efficiency has also increased in one of the cases more than 4% and energy recovery about 2%. So, it can be concluded that this method can be used in seasons when the pressure change of the membranes is noticeably higher or lower than the initial design pressure.

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.

In this study, the thermodynamic and thermoeconomic analysis of an Absorption Heat Transformer (AHT), Organic Rankine Cycle (ORC) and Reverse Osmosis (RO) desalination combined system was performed. The performance of the system was examined with the objective of generating electricity and fresh water from low temperature heat sources. All analyses are carried out based on the thermodynamic and thermoeconomic laws by programming in the EES software. The results have shown that the AHT with increase temperature to 105°C, is produced 494.7 kW thermal energy in absorber, having the Coefficient of Performance (COP) of 0.4372. By applying the AHT produced thermal energy; it is possible to produce 63.15 kW of electricity in the ORC. By using this amount of electricity in the reverse osmosis system, 216.2 m3/day of freshwater are produced where the cost of this amount of water produced achieved 2.374 $/m3. Also, in thermoeconomic analysis, the unit cost of the exergy for all points of the system and the unit cost of the electricity and fresh water were calculated. The levelized cost of electricity at different heat rates was determined, according to the results, the levelized cost of electricity is reduced when the heat rate increases. Also the effects of interest and inflation rate changes on the unit cost of the fresh water were studied.

The feed channel spacers cause the membrane plates to be separated. These mesh spacers increase the pressure drop in the channel and, in contrast, improve the mass transfer process. In this study, investigate hydrodynamics and mass transfer in the spacer-filled channel in the Reverse osmosis module by using the simulation of computational fluid dynamics coupled with response surface method. Input parameters include the average inlet velocity, the attack angle, the mesh angle, and the output parameters include the pressure drop over the computational domain and the water flux across the membrane walls. The Latin Hypercube Sampling Design method was used to sample the input parameters and the Kriging model has been used for response surface model. Also, genetic algorithm and Screening was used to determine the optimal output parameters. The sensitivity analysis of the input parameters on the output parameters indicates that the average inlet velocity and the attack angle are the most and the least influential parameters respectively. The optimum configuration taking all the operational parameters into account was stood up at the attack angle of 72.74 degrees, the mesh angle of 85.19 degrees, and the inlet velocity of 0.13 m/s.