In the below figure the operation of the desalination is presented which is also used for the wind turbine and charge batter along with use of battery which is driving the small pumps, and create water enter that is also shown in above figure of design and after pass by the Y-type strainer water.
Figure : Desalination device flow chart
Desalination systems energy analysis of Wind energy (Kinetics energy) to electrical energy and thermal energy to be used in a desalination plant
According to requirements first of explains the Desalination systems energy analysis, in this according to first law of thermodynamics , is the significant and evaluating process for the performances of the desalination plant line the analysis which does not take into account for the quality of energy that transferred. In the actual desalination process the use of energy is the process of the thermodynamic in the point of view which is also growing the importance and it identify the sides for the greatest losses and it is also improve the process performances. The desalination plant perform the separation process where the saline water is separated by two output streams , like the product of water and it is also contains the high concentration for the dissolved slats. Thus analyzing the desalination process where the properties of pure water and slats also taken into account , and the important properties like the analysis of the salinity where it is expressed in part per million and the salinity = mass fraction mf_s×10^6.
The salinity is 2000 ppm and its coorsposnd salinity of 0.2% of salt and mass fractions of mf_s=0.002, whereas the mole fraction of salt, x_s is obtained [13]
mf_s=m_s/m_sw
mf_s=(N_s M_s)/(N_sw M_sw )
mf_s=x_s M_s/M_sw (1)
Similarly;
mf_w=x_w M_w/M_sw (2)
Whereas
m =mass (kg).
M = molar mass (kg/kmol).
N = number of moles.
x = mole fraction.
In above two equation subscripts s,w and sw for the water and the salts along with saline water. The saline water has the apparent molar mass;
M_sw=m_sw/N_sw
M_sw=(N_s M_s+N_w M_w)/(N_s w )
M_sw=x_s M_s+x_w M_w (3)
The molar mass of the water is 18.0 kg/mol and the molar mass of the NaCl is 58.5kg/mol
The equation 1 and 3 is considering that x_s+x_w=1 and it also gives the relation’s for mass converting faction to the mole fractions [14]
x_s=M_w/(M_s (1/(mf_s )-1)+M_w )
And
x_w=M_s/(M_s (1/(mf_s )-1)+M_s )
Exergy analysis of thermal desalination systems of Wind energy (Kinetics energy) to electrical energy and thermal energy to be used in a desalination plant
Form the first law of thermodynamics the energy balance equation given below;
∑_in▒E_j +Q= ∑_out▒E_j +W
For all plant subsystem , the mass ,spices and the energy balances along with connected effects and states reacted to function is set of independent equations [15].
Energy balances for the steady states equation can be written as;
Total energy transported into system = total energy transported out of system + Energy destroyed in system
Thus;
∑▒E_in = ∑▒E_out +I_T
Where;
∑▒E_in = ∑▒E_(sw,in) +∑▒E_stream +∑▒E_pumps
And;
∑▒E_out = ∑▒E_cond +∑▒E_br
The irreversibility of overall system can be expressed like the summation of the subsystem
I_T= ∑_J▒I_i
Whereas the J is the number of subsystem in an analysis along with the I_i irreversibility rate of subset is i.
The efficiency is η_II=(∑▒E_out )/(∑▒E_in )
With E_in ,and E_out is determined form the above calculations, and the efficiency of energy is defect the δ_i for each subsystem;
δ_i=I_i/(∑▒E_in )
By combining η_II above two equations;
η_II+δ_1+δ_2+⋯…δ_j=1
Form the properties the working of energy is calculated and it is given by;
E=M[(h-h_0 )-T_o (s-s_0 )]
In the above equation the subscripts presented the “dead states”
Wind energy desalination Calculation
To explain the wind energy desalination calculation as shown in the above designed of the solar stills; first of all explain thermal model which the requirement of the desalination plant. Inside enclosure of the desalination unit the humid air with the heat transfer is occurs by free convection and it is also caused through the buoyancy actions of force which is caused though the variations of the humid air. The variation of density which is caused trough the gradient temperature in a fluid, and the heat transfers form a surface of water where the glass cover the q ̇_cw through the convention is estimated;
q ̇_cw=h_cw (T_w-T_g )
Whereas the h_cw is determine form the relation
N_u=〖h_cw.d〗_r/K_f
N_u=(Gr.Pr)^n
Where;
G_r= (δβ`ρ^2 (d_r )^3 (∆T))/μ^2
P_r= (μ.C_p)/k_f
∆T=(T_w-T_g )+ [((P_w-P_g )+ (T_w+273))/(268.0×10^3-P_w )]
Evaporate the heat transfer rate q_new is given by;
q_new=0.016273(P_w-P_g ).h_cw
q ̇_new= 0.016273(P_w-P_g ).(k_f/d_f ).C(R_a )^n
Where R_a=Gr.Pr〖,and alos 〗
M ̇_w=(q ̇_new×3600)/L
Above equation can be written as;
M ̇_w=0.016273(P_w-P_g ).(k_f/d_f ).(3600/L) .C(R_a )^n
Therefore;
M ̇_w/R=C(R_a )^n
Whereas;
R=0.016273(P_w-P_g ).(k_f/d_f ).(3600/L)
The field conditions and the values T_w and T_g vary significantly due to variations so the climatic conditions as well as correspondingly M_w and R_a alos vary.
References of Operation of designs of Wind energy (Kinetics energy) to electrical energy and thermal energy to be used in a desalination plant
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