Report on Multi Stage Flash water is separated and evaporated by the MSF

From the sea water the water is separated and evaporated by the MSF, that is also the series of the flash evaporation. Every flash subsequent for the process is used the energy which is released from the concentration of the water vapor form the previous step. The process of the MSF which is dived into different stages of sections and the water saline is heated at the boiling temperature among the 90°-110°wit pressure decreasing by the stages. The part of the water flashes for the every stages while a rest continues for flow by the following stages in below figure; 

Figure: MSF Desalination Process

The process of MSF could be powered through product heat or waste which is combine the production of power, desalinated water, heat in the same plants. 

Solar thermal Desalination 

Desalination of seawater by the MED and MSF by using solar heat like the input energy which is promising process of the Desalination and it is based on the renewable energy resources. Desalination plant is also consisting with the two parts; 

Solar heat collector 

Distiller  

This process is referred like the indirect process where the heat comes from the collector of solar and its separate the solar ponds where it is also referred to direct component like the integration of solar plant [8]. The solar radiation is collected by the CSP (Concentrating solar power and it is also provides the high temperature for the generation of electricity. Thus it is also associate with the with the desalination membrane for example, RO (reverse osmosis) plus units of thermal desalinations. CSP-MED process is the more energy efficient as compare to the CSP-RO process where the seawater has the high level of salinity. For example the scheme of the CSP-MED is presented in the below figure [9]; 

Figure: CSP power plant with oil steam generator and MED desalination

Source: [9];

MED Process of Wind energy (Kinetics energy) to electrical energy and thermal energy to be used in a desalination plant

In the figure, the indicated process of MEB is composed of different elements which are referred to as effects. And the steam attained form one effect is utilized as a heating fluid in the other effect. In addition to it, while condensing, it causes evaporation of the solution’s distillate. The steam produced in the effect enters the following effect and evaporates the solution. This process continues one and in order to make this process possible, it is important for the heated effect to be pressurized lower than the pressure from which the steam is originating. For preheating the feed, solutions which are condensed are used [10]. 

Figure: Principle of operation of a multiple-effect boiling (MEB) system

Vapor, in this process, is created by boiling and flashing. However, distillate’s majority is created through the process of boiling. The MEB process, unlike an MSF plant, normally operates through the system without a large amount of brine which recirculates around the plant. Both scaling tendencies and pumping requirements are reduced by this design. Similar to the plant of MSF, the produced brine in the process of MED passes through a number of heaters. However, after it passes through the last ones, rather than entering the heater of brine, the feed seems to enter the top effect in which the temperature is raised by the heating steam to the saturation temperature for the pressure of effect. In addition to it, further steam amounts are utilized for producing evaporation in an effect either from a boiler or a system of solar collector. Then, the vapor goes for heating the incoming feed and providing the supply of heat for the second effect. This effect is present at a significantly lower pressure and feed is received by it from the first effect’s brine. Through the plant, this process seems to continue and the distillate passes down the parts of plant. In general, both the distillate and brine flash as they pass down the parts of plant because of a significant decrement in pressure. 

Figure: Long tube vertical (LTV) MEB plant.

As indicated in the above figure, the brine in LTV plants boils within the tubes while the steam is condensed outside. The steam condenses in the horizontal tube while the brine evaporates on the outside.  The underlying principles, with multiple evaporation, is concerned with utilizing the energy of leaving steams for producing more distillate. The ratio of Md/Mf, in the system of MEB, is limited by the optimum concentration for a value in the 2nd order and is offered by [11].

References of Multi Stage Flash of Wind energy (Kinetics energy) to electrical energy and thermal energy to be used in a desalination plant

[1] S. Kalogirou, "2005, Seawater desalination using renewable energy sources,," Energy & Combustion Science , vol. 31, pp. 242-262, 2005. 

[2] EA-ETSAP and IRENA, "Water Desalination Using Renewable Energy," ENERGY TECHNOLOGY SYSTEM ANALYSIS PROGRAMME, 2013.

[3] A. Subraman, "Energy minimization strategies and renewable energy utilization for desalination: A review," Water Research, vol. 45, no. 5, p. 1907–1920, 2011. 

[4] U. Caldera, "Caldera, U., Bogdanov, D., & Breyer, C. (2016). Local cost of seawater RO desalination based on solar PV and wind energy: A global estimate.," Desalination, vol. 385, p. 207–216., 2016. 

[5] Openei.org, "Wind energy," 20 November 2018. [Online]. Available: https://openei.org/wiki/Wind_energy.

[6] Q. Ma, "Wind energy technologies integrated with desalination systems: Review and state-of-the-art," Desalination,, vol. 277, no. 1-3, p. 274–280, 2011. 

[7] D. Mentis and e. al, "Desalination using renewable energy sources on the arid islands of the South Aegean Sea," Energy , vol. 94, p. 262–272, 2016. 

[8] E. Tzen, " Wind-Powered Desalination—Principles, Configurations, Design, and Implementation.," in Renewable Energy Powered Desalination Handbook, 2018, p. 91–139.

[9] U. Caldera and e. al, "Local cost of seawater RO desalination based on solar PV and wind energy: A global estimate," Desalination, vol. 385, p. 207–216, 2016. 

[10] F. Latorre and e. al, "F.J.G. Latorre, S.O.P. Báez, A.G. Gotor, Energy performance of a reverse osmosis desalination plant operating with variable pressure and flow,," Desalination, vol. 366, p. 146–153., 2015. 

[11] V. Belessiotis and e. al, "Solar Distillation—Solar Stills," in Thermal Solar Desalination, 2016, p. 103–190..