Condenser Water Make-Up System Calculations for Block 02

A. Condenser Water Loss Calculations

1. Evaporation Loss (E)

E = R × ΔT × f × 0.00153

Where:
R = Recirculation rate = 1066.5 m³/hr
ΔT = Temperature difference = 5 °C
f = Load factor = 1 (for design conditions)
0.00153 = Empirical constant (°C⁻¹)

E = 1066.5 × 5 × 1 × 0.00153 = 8.16 m³/hr

2. Drift Loss (D)

D = R × d

Where:
d = Drift rate = 0.00005 (0.005% for high-efficiency eliminators)

D = 1066.5 × 0.00005 = 0.053 m³/hr

3. Blowdown Loss (B)

B = E / (C - 1)

Where:
C = Cycles of concentration = 5 (recommended 3-6)

B = 8.16 / (5 - 1) = 2.04 m³/hr

4. Leakage Loss (L)

L = System volume × l

Where:
System volume = 70 m³
l = Leakage rate = 0.0005 (0.05% per hour)

L = 70 × 0.0005 = 0.035 m³/hr

5. Total Make-Up Water Requirement (M)

M = E + D + B + L

M = 8.16 + 0.053 + 2.04 + 0.035 = 10.29 m³/hr

Note: Recommended design margin of 20% → 12.35 m³/hr

B. Elevated Make-Up Water Tank Sizing

1. Storage Capacity (V_tank)

V_tank = M × t × SF

Where:
t = Autonomy time = 4 hours (recommended 4-8 hrs)
SF = Safety factor = 1.2

V_tank = 10.29 × 4 × 1.2 = 49.4 m³

Recommend standard size: 50 m³

2. Tank Dimensions

Assuming cylindrical tank:
Diameter (D) = 3.5 m
Height (H) = V / (π × (D/2)²)

H = 50 / (3.1416 × (3.5/2)²) = 5.2 m

Actual tank height with freeboard: 5.5 m

C. Make-Up Water Pump Selection

1. Pump Flow Rate (Q_pump)

Q_pump = M × SF / n

Where:
SF = Safety factor = 1.2
n = Number of operating pumps = 2 (1 duty + 1 standby)

Q_pump = 10.29 × 1.2 / 1 = 12.35 m³/hr

2. Pump Head Calculation

H_total = H_static + H_friction + H_pressure

3. Pump Specifications

4. Pump Rest Time Calculation

t_rest = V_tank × (L_min - L_start) / M

Where:
L_min = Minimum level = 20%
L_start = Pump start level = 30%

t_rest = 50 × (0.3 - 0.2) / 10.29 = 0.49 hours (29 minutes)

D. Pipe Sizing for Make-Up Line

1. Flow Velocity Calculation

v = Q / A

Target velocity range: 1-2 m/s

Recommend: DN65 (2½") Schedule 40 PVC pipe

2. Pressure Drop Verification

Using Darcy-Weisbach equation:

ΔP = f × (L/D) × (ρ × v²)/2

Where:
f = Friction factor ≈ 0.02 (PVC)
L = Pipe length = 100 m
D = Pipe diameter = 0.065 m

ΔP = 0.02 × (100/0.065) × (1000 × 1.03²)/2 = 16.3 kPa (1.63 m)

Acceptable (less than 10% of total head)

E. Tank Height Calculation

1. Minimum Required Height (H_min)

H_min = (P_req × 10.2) + H_f + H_static

Where:
P_req = Required system pressure = 2 bar
H_f = Friction losses = 3.5 m
H_static = Static height difference = 5 m

H_min = (2 × 10.2) + 3.5 + 5 = 28.9 m

2. Available Height

H_available = Building height + tank support

H_available = 25 + 3 = 28 m

Recommendation: Increase tank support by 1 m or add booster pump

F. Summary of Key Parameters

G. Editable Variables Table