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Recent content by Bos88

  1. Bos88

    Outdoor water-cooled chiller

    I don’t have all the details of the container but technically it is a standard shipping container modified to accommodate the chiller, pumps, LV MCC, The cooling tower is optional. You can ask the manufacturer to supply what you need only.the bug question is what cooling capacity do you need ...
  2. Bos88

    Outdoor water-cooled chiller

    Why don’t you investigate prefabricated chiller plant (water-cooled). If the cooling capacity is « small » there are solutions available using 20 to 40 foot containers type design. For larger chiller it would be more a custom option but it is available for very large capacities using multiple...
  3. Bos88

    Chillers - Efficiency

    lukaiENG, agree with you. You need as well to check with cooling tower supplier to make sure flow reduction can be done (newer tower models can get to 50% and some to 30% but older models might be limited to 70% max). This also changes if is a crossflow or counterflow (the counterflow nozzles...
  4. Bos88

    Chillers - Efficiency

    nglty, yes I bring 2 towers and 1 pump. Most likely the reason you see VFD on condenser pump is to balance the flow during commissioning. The VFD gives some flexibility for this. Once they have the desired flow, they often run the pump at constant speed.
  5. Bos88

    Chillers - Efficiency

    I did not use any modeling tool. I actually ran selections for chillers, towers and pumps. Got the condenser water data at different fan speed using the manufacturer selection program and the part-load data from the chiller manufacturer program as well I used 85F-95F for the sake of the...
  6. Bos88

    Chillers - Efficiency

    Sorry somehow I posted twice my answer
  7. Bos88

    Chillers - Efficiency

    May be this will help. I ran an example comparing 1 x 800 TR vs 2 x 400 TR using chillers with and without VFD. The chillers were all selected with same Full load efficiency and NPLV values (VFD or non-VFD). I also selected the pumps and cooling towers. The overall installed efficiency was also...
  8. Bos88

    Chillers - Efficiency

    May be this will help. I ran an example comparing 1 x 800 TR vs 2 x 400 TR using chillers with and without VFD. The chillers were all selected with same Full load efficiency and NPLV values (VFD or non-VFD). I also selected the pumps and cooling towers. The overall installed efficiency was also...
  9. Bos88

    COOLING TOWER SELECTION WRONG

    The drawing shows the pumps to be rated for 1700 GPM. Typo?
  10. Bos88

    COOLING TOWER SELECTION WRONG

    HI Moideen, Based on your 18.5 kW nameplate, the head should be around 60 feet for the pump (1350 GPM). Using 15 Feet for tower, 20 feet chiller, that gives you about 25 feet for the piping/valves.
  11. Bos88

    COOLING TOWER SELECTION WRONG

    In the original design concept, is one of the chiller a standby? or both are supposed to run. Now I wonder in summer how do they cope with load if they have to run 2 towers for 1 chiller and the 2nd chiller needs to start as well? If you are getting 89F wet bulb, you will end up with 96F...
  12. Bos88

    COOLING TOWER SELECTION WRONG

    DrRTU, I guess we need Moideen to clarify what is exactly the problem on his system. In reply to LittleInch, the 86F WB is actually correct for this part of the world. Actually it can get even higher some days. The RH on the cooling tower selelction is 50% by default. SPX Marley uses this...
  13. Bos88

    COOLING TOWER SELECTION WRONG

    In my opinion DrRTU, they have a total of 2700 GPM in the system with each tower handling 1350 GPM and each chiller receiving 1350 GPM condenser flow. The Selection Datasheet actually is for the design point for 1 Cell and it shows 1350 GPM. Now if they have installed different towers and have...
  14. Bos88

    COOLING TOWER SELECTION WRONG

    I would not worry too much here. What you have is simply a written process description. They simply called the cooling tower a 450 TR tower same as the chiller capacity. I don't think they even thought of mentioning heat rejection in that description. What you need to look at the actual values...
  15. Bos88

    COOLING TOWER SELECTION WRONG

    I don't think your cooling tower is undersized. The cooling tower suppliers use 15000 Btuh to calculate Equivalent chiller tons. In your example, 1350 gpm *500 * 10 = 6,750,000 buth. Divide this by 15000 = 450 tons or rather cooling tower tons. If you divide the result by 12000 you will get the...
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