ปัญหาจากค่า Delta-T ต่ำา

1 1614 Q = mcp T (1) Q(Btu/h) = 500 GPM T(IP unit) Chilled water variable flow T ( Delta-T ) T ( Delta-T ) Supply Chilled water Temp.(SCHT)and Return Chilled water Temp.(RCHT) Q flow rate (1) AHU Chiller T ( Delta-T ) AHU Q load AHU control valve flow load T ( Delta-T ) AHU T ( Delta-T )

2 Chiller Primary loop Q Capacity chiller T chiller chiller Delta-T .605 . 12,14 . 62 . 77 .10250 02-721-0000 02-322-0575-6E-mail : chiller Primary flow flow rate Primary chilled water pumps(PCHP) T Secondary chilled water loop Q load Secondary flow flow rate secondary chilled water pumps(SCHP) , T (SCHT-Supplied chilled water temp.)

3 (RCHT-Return chilled water temp.) Secondary flow AHU flow/Tr ( deta-T ) deta-T flow Secondary chilled water loop Flow control valves & SCHPs Primary pumps Primary flow Secondary flow chiller bypass 15 Delta-T Delta-T chillers ( Primary flow Secondary flow)

4 RCHW bypass LCHW Supply Chilled water Temp.(SCHT) air side AHU - capacity chillers water cooled chiller (LCHT.) (Setpoint) capacity Q capacity chiller chiller flow ( flow primary VSD Flow ) Primary flow chiller capacity leaving chilled water temp.

5 (LCHT) (RCHT) (Low Delta-T ) chiller LCHT setpoint chiller (Unload) 100% flow flow rate deta-T AHU full load control valve pressure drop valve

6 Low load control valve flow flow load Control valve low load close off rating valve differential pressure valve control valve balance AHU AHU main / branch Direct return chilled water pipe ( ) Air flow AHU VAV low load VAV pressure drop filter cooling coil (Air side) (Water side)

7 Fincoil cooling coil Control valve flow load cooling coil laminar flow 1616 Delta-T Chiller plant manager flow Primary loop Secondary loop Flow/Tr Primary loop Secondary loop thermostat AHU control valve AHU control valve flow load Outdoor AHU Delta-T flow water side chiller plant manger primary water flow secondary water flow Primary chilled water pump(PCHP) chiller ,condenser water pump(CDP)

8 , Cooling tower chiller capacity Delta-T return water temp. chiller (Unload) Delta-T 1 chiller plant primary-secondary pumps tertiary pump Delta-T Figure 1flow rate flow rate chillers

9 3 chillers flow rate, load, LCHT flow flow primary secondary primary flow secondary flow flow bypass primary chiller bypass return secondary pumps chiller primary pump flow bypass flow primary pump 1 load chiller

10 Load 1 Delta-T load flow flow chiller primary pump 17 Delta-T Delta-T = 14 F (flow= ) Delta-T 7 F (flow= gpm/Tr) chiller 50 % 50% performance ( performance chiller 65-85 % chiller ) load Delta-T secondary flow RCHW(Return chilled water temp.)