MCS (Mist Cooling System) for Air Cooled Condensers :

NOZZLE ARRANGEMENT/ DESIGN

The degree to which water sprayed in to inlet air stream which evaporates raises a number of important questions. Incomplete evaporation introduces several problems. Un evaporated droplets contributes nothing to cooling effects but add to the plant water use if they cannot be collect & recycled . If they are carried into the ACC’S  finned tube bundles, there is a danger of scaling and corrosion of surfaces. Producing extremely fine spray can approach complete evaporation, but results in high pressure, low flow design of nozzles which shall also require a strong back up filtration system.

MREPL has successfully developed Mist Creator Nozzles with a bore size of 8 to 10 mm which can produce Mist of size up to 5 microns. Due to such high bore size, it operates with a choke-less design. Also nozzles are arranged just below fans of ACHE/ACC in such a fashion that they spray water down-wards as shown in the enclosed schematic diagram.

COST BENEFIT ANALYSIS

For 20 MW POWER PLANT BY INSTALLATION OF MIST COOLING SYSTEM FOR
AIR COOLED  CONDENSER / HEAT EXCHANGER

A)              Design Basis
1)              Air Inlet Temperature                                                  :                 40°C
2)              Max. Site Ambient temp                                             :                 48°C
3)              Wet Bulb temp ( Max.)                                                :                 31°C
4)              No. of Hot Days / Year                                                :                 135
5)              No .of Hot hours/Day                                                  :                 8
6)              Total no of Hot hours/ Year                                        :                 1080
7)              Power Output at design Air temperature                 :                 20 MW
8)              Total Operating Hrs/Year                                            :                 8000
9)              Design Vacuum at TG exhaust                                 :                 0.18 ATA

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