A novel design for a solar powered multistage flash desalination

In this paper, a mathematical model for multistage flash (MSF) desalination plants was developed. The model was based on basic principles of physics and chemistry that describe the stages occurring in the desalination process. The input plant parameters that are known to affect the operation of the MSF desalination plant and its performance was taken into account in the construction of the model. These parameters included make-up flow, brine recycle flow, seawater flow, seawater temperature, seawater concentration, top brine temperature (TBT), steam temperature and the plant load. For each stage, the developed model was used for predicting the temperatures of the brine, distillate and cooling brine, and the flow rates of brine outlet and distillate production. The developed model was evaluated with the MSF plant vendor simulation results and its actual operating data. The evaluation indicated that model predictions matched well with the vendor simulation results and the plant operating data. The developed model is sufficiently accurate and model predictions can be relied upon. Therefore, it may be recommended for determining optimum set point of a running MSF desalination plant at different loads to maximize the water production or minimize energy consumption. It can also be used to calculate controller set points for different loads of the plant. Copyright © 2011 John Wiley & Sons, Ltd.

Multi stage flash desalination plant with brine–feed mixing and cooling

Component-based, dynamic simulation of a novel once through multistage flash (MSF-OT) solar thermal desalination plant

The present study is applied on the seawater multi-stage flash (MSF) desalination plant that is currently under operation in E-Zuetina operations plant located in Libya. The plant contains 21 evaporator stages at capacity of 10025 (ton/day). The presented operating data has been collected during a visit of the plant, a mathematical model for multistage flash (MSF) desalination plants was developed. The model was based on basic principles of physics and chemistry that describe the stages occurring in the desalination process. The input plant parameters that are known to affect the operation of the MSF desalination plant and its performance were taken into account in the construction of the model. These parameters included make-up flow, brine recycle flow, seawater flow, seawater temperature, seawater concentration, steam temperature and the plant load. For each stage, the developed model was used for predicting the temperatures and pressure of the brine, distillate, cooling brine, and the flow rates of brine outlet and distillate production. The developed model was evaluated with the MSF plant vendor simulation results and its actual operating data. The evaluation indicated that model predictions matched well with the vendor simulation results and the plant operating data. The developed model is sufficiently accurate and model predictions can be relied upon. Therefore, it may be recommended for determining optimum set point of a running MSF desalination plant at different loads to maximize the water production or minimize energy consumption. It can also be used to calculate controller set points for different loads of the plant. Keywords:E-Zuetina MSF Desalination Plant, case study, stage model, brine heater.

Techno-economical simulation and study of a novel MSF desalination process

Novel multi-stage flash (MSF) desalination plant driven by parabolic trough collectors and a solar pond: A simulation study in UAE

Thermal desalination technologies are very energy intensive. The utilisation of nuclear energy for seawater desalination provides a safe, feasible and economic solution for the production of very good quality water. The Multi-Stage Flash (MSF) desalination plant of the Nuclear Desalination Demonstration Project (NDDP) of the Department of Atomic Energy (DAE), Government of India, is coupled with a nuclear power plant on the south east coast of India to share the common facilities and steam. The MSF desalination plant is under construction. This paper describes a case study of the coupling aspects of the MSF desalination plant with the existing nuclear power plant and gives an estimate of the loss of electrical power generation due to extraction of steam. Loss of electrical power is also compared with the Desalination Economic Evaluation Program (DEEP) of the IAEA.

Development of Hybrid Fuzzy-GMC Control System for MSF Desalination Process

An adaptive scheme with an optimally tuned PID controller for a large MSF desalination plant

Neural networks for the identification of MSF desalination plants

Scale formation model for high top brine temperature multi-stage flash (MSF) desalination plants

Studies by simulation on the model of a multistage flash (MSF) desalination plant have shown certain features of the model developed, on the basis of physical laws and correlations. The most important of these is nonlinearity which relates to the changing of the process characteristics with the operating conditions. It is shown that a fixed PID controller cannot be optimal, if the operating point changes from the one at which the optimal controller was designed. In this paper, the parameter variations in the linearised plant model have been modelled over the operating region of interest, and these are mapped into the parameter space of the optimal PID controller. The resulting algorithm is a parameter scheduling scheme for the MSF plant for optimal PID control with a choice among four criteria (ISE, IAE, ISTE, and IATE). The scheme illustrated is with reference to the top brine temperature control of an actual 18 stage MSF desalination plant.

This article presents the results of an investigation on the corrosion of flash chamber floor plates in a multistage flash (MSF) desalination plant. In an MSF plant, desalinated water is produced by flashing deaerated seawater in successive flash chambers under reduced pressure. The flash chamber floor plates were made of carbon steel with AISI type 317L stainless steel (UNS S31703) internal cladding. The thickness of the carbon steel and cladding was 8.5 and 3 mm, respectively. Approximately four years after the plant was commissioned, indications of corrosion processes, in the form of numerous red-colored spots, were noticed on the floor plates.

Over the past few decades, the growth of the earth’s population has increasingly contributed to global warming, and increased demand for fresh water on top of a need for a greater power supply. This paper will analyze the integration of a combined- gas turbine with intercooler and a multi-stage flash (MSF) desalination plant for the simultaneous generation of electricity and supply of water and improved performance. The paper will also examine the calculation of the production cost and the capital cost of the MSF desalination plant. The thermo-economic analysis of the study was conducted using the IPSEpro software system. Also, exergy losses of the gas turbine and MSF desalination unit were also calculated. The desalination plant uses the exhaust gases from the gas turbine, as a form of thermal energy, and discharges to feed the seawater heater. A portion of the desalinated water is used to cool the compressed air in the intercooler heat exchanger. Results indicate the improvement in the gas turbine’s performance when desalinated water is used for the intercooler between compressor stages, as the power output increased by 59% over the the simple gas cycle and found decrease with an increase in the ambient temperature. The desalinated water cost was calculated to be $1.7 per cubic meter after determining the optimal configuration and operating conditions. A decrease in steam cost by 36% was observed when the waste heat from the gas turbine was used as the source of thermal energy. Part of this reduction can be explained by the observation that the desalination plant’s pumps consume part of the power generated by the gas turbine.

The fossil fuels that power conventional desalination systems cause substantial environmental impact. Solar desalination can satisfy critical water needs with only a minimal contribution to global warming. The current work presents an attractive new design suitable for regions with limited water resources and high solar radiation rates. This work is an experimental study of a newly designed, solar-powered, multi-stage flash (MSF) desalination plant. The design could address the need to increase the limited water resources in solar energy-rich areas. The prototype consists of a solar collector, an MSF unit, and a novel dual thermal storage tank design. In this prototype, preheated brine is directly heated by circulation through the solar collector. Two tanks serve the MSF unit; one tank feeds the MSF unit while the other receives the preheated feed water. The two tanks alternate roles every 24 h. The study was conducted in Taif, Saudi Arabia, throughout the month of September 2020. The results of the experiment showed that 1.92 square meters of solar collector area is needed for an average daily production of 19.7 kg of fresh water, at a cost of approximately $0.015 per liter.