MULTIPLE EFFECT DISTILLATION OF SEAWATER WATER USING SOLAR ENERGY - THE CASE OF ABU DHABI SOLAR DESALINATION PLANT - Energy Research Developments: Tidal Energy, Energy Efficiency and Solar Energy - page 47

C

(

T

)

+ C

(

T

)

U = ( 1888 × L + 1313 ) ×

1 2

(58)

2

• Calculate an improved value for the first effect temperature, T 1,

U

T = T + ( L × δ T × + BPE ) × N

1 2

U

d

• Iterate to get improved values for T 1 .

The heating water outlet temperature was assumed to be equal to the first effect
temperature: T h2 = T 1 and the heating water inlet temperature is calculated from a heat balance
equation:

Q

T = T +

h

(59)

h 1 h 2

m × C

h p

The power consumption (in kW) of the evaporator was assumed to depend mainly on its
capacity and was estimated from the following equations provided by the manufacturer
(Sasakura):

Evaporator capacity m d ≤ 500 m 3 /day:

− 5 2 − 2

P = − 1 25 × 10 × m + 9 . × 10 × m + 5 125 + Z (60)

d d

Evaporator capacity m d ≥ 1000 m 3 /day:

− 6 2 − 2

P = − 6 00 × 10 × m + 5 × 10 × m + 32 . + Z (61)

d d

Evaporator capacity 500 m 3 /day < m d < 1000 m 3 /day

− 5 2

P = − 4 48 × 10 × m + 0 1272 × m − 5 + Z (62)

d d

where Z is the pumping power (kW) of the vacuum pump and is given by:

Z = 0 050535 × m + 0 93045 (63)

d

9.2. Comparison of Simulation and Actually Measured Values

In order to determine the accuracy of the simulation program, a comparison between the
simulation results and the results from actual plant operation was conducted for January and