Learning, our way Exercise Water pipe, Pump and Cooling Tower Selection

Learning, our way Watercooled VRV Selection: VRV WII - Express Cooling Load per floor is 40 kW, Heat load 16.5 kW –10 HP VRV unit gives >130% connection ratio –20 HP VRV unit gives % connection ratio, Depending on piping length –30 HP VRV unit gives <66% connection ratio 20 Hp unit is selected

Learning, our way Cooling unit Selection Cooling tower, evaporative cooler or dry cooler? Approach: 8°C, mild climate. Europe, small scale installation (No large water purification installation needed) Type: Evaporative fluid coolers Brand Baltimore: Type VXI

Learning, our way Cooling mode: (VRV express) Total heating capacity available= 49.5W *4 Total Power Input at 98% connection ratio = 9.0 kW *4 Total rejected heat = 4 *( )= 234 kW Total water flow (= max water flow )= 96 * 2* 4 = 768 l/min = 12.8 l/s Range= EWC – LWC = rejected heat / (4.186 x water flow) =177.6 / (4,186 x 12,8)= 4,37°C EWC= cooling tower entering water temperature= ,4 = 34,4°C LWC= cooling tower leaving water temperature = 30 °C Approach = LWC – WBT = 30°C – 22°C = 8°C Calculations Evaporative Cooler Selection:

Learning, our way Selection Evaporator Determine the performance factor using the diagrams provided by Baltimore: Input: Range = 4.4 Approach = 8°C WBT = 22°C Output: Pf = 5

Learning, our way Evaporative cooler selection

Learning, our way

Cooling mode: ACCORDING TO DATABOOK is different?? A lot higher, 10 HP… Total heating capacity available= 56.7kW *4 Total Power Input at 98% connection ratio = 12.3kW *4 Total rejected heat = 4 *( )= kW Total water flow)= 96 * 2* 4 = 768 l/min = 12.8 l/s Range= EWC – LWC = rejected heat / (4.186 x water flow) = = 177.6/(4,186 x 12,8)= 4,4°C EWC= cooling tower entering water temperature= ,3 = 33,3°C LWC= cooling tower leaving water temperature = 30 °C Calculations Cooling tower Selection:

Learning, our way Heating mode: Total Heat capacity required= 63 kW *4 Total Power Input = 6 kW *4 Total injected heat = 4 *(63-6)= 228 kW Calculations Boiler Capacity:

Learning, our way Water piping: water flow rates Each VRV has as design waterflow –96 l/min per 10 Hp unit. Horizontal piping to indoor units: –2 x 96 l/min = 192 l/min Vertical parts: Different sections A, B, C, D –Secton A: Only 1 20 HP unit: 192 l/min (=3,2l/s) –Section B: 2x 20 HP unit : 384 l/min (=6,4l/s) –Section C: 3x 20 HP unit, 576 l/min (=9,6l/s) –Section D: 1x 10 HP Sub-unit, 96l/min (=1,6l/s) –Section E: 4x 20 HP unit: 768 l/min (=12,8l/s) Reverse Return Distriubution * * A B C D E A C B

Learning, our way Piping diameters Reccomendations: Pipe diameter (mm) Velocity range (m/s) ~ ~ ~2.1 Around 250.6~1.2 A B C D E

Learning, our way Reference Path: Take worse case: 3m C+B+C+horizontal: 3m A+B+C+horizontal Linear Head Loss Using Friction loss graph: Opposite effect of joints Comparable results! Part:Flow rate (l/s) Diameter (mm) Water velocity (m/s) Length (m) Pressure loss per meter (Pa/m)=10m H 2 O/m Total (mH 2 O) A ,52x ,91 B ,21 C ,53500,15 D ,92 x 1500,1 E , * * A B C D E A C B

Learning, our way Linear Head loss (Water piping selector) Reference Path: take worse case. 3m C+B+C+horizontal 3m A+B+C+horizontal:  Comparable (0,06 mH2O difference) Part:Flow rate (l/min) Diameter (mm) Water velocity (m/s) Length (m) Pressure loss per meter mH 2 O/m Total (mH 2 O) A ,52 X ,91 B ,21 C ,53500,15 D 96400,92 x 1500,1 E , ,18 * * A B C D E A C B

Learning, our way Water Pipe Design: Local Head losses Local friction losses: For 1 water route: –3 branches “Straight Trough” -2 x “Trough Branch” connection on main line (2 for each 10 HP unit, speed ) -2 x “Trough Branch” Joint on indoor piping -2x 3 elbow joints on indoor piping Straight line friction losses: –4 x 3 m vertical piping, –2 x 3 m indoor piping * * A B C D E A C B

Learning, our way * * A B C D E A C B Local Head loss: Blue path T joints “Straight Trough” E to C C to B B to A. Partial head loss Ht Location: Number ON 1 water path Equivalent piping length (m) Pressure loss / m (mmH 2 O/m) Pressure loss (mH2O) Elbows on A 2* * Elbows on D 2*12 * Elbows on E 22 * 1, T-joints Staight-tru (on main line) 31, T-joints Tru Branch (on main line) T-joints Tru Branch (on horizontal line) T joint “Trough Branch” A to E B to A A to C E to C C to B C to E vs Red path name Diam (mm) A 50 B 65 C 80 D 40 E Total: +0.20

Learning, our way Piping design – pump selection properties H = H a + H f + H t + H k H t = Linear Head loss = 1.55 mH 2 O H a = Actual head (m H 2 O) = 0 H t = Partial friction loss = 2,23 m H 2 O H k = Internal friction loss = 2,7 mH 2 O 1 x 1 VRV 10 HP unit, at 96 l/min H k2 = Given, 5 mH 2 O Total head loss= 11,48 mH 2 O at a flow rate of 768 l/min 46 m 3 /hr mH 2 O

Learning, our way Water piping design: Pump Pre-selection LRC 406

Learning, our way Pump Selection: Pump /3 or above