Retrotec USACE - Manual (Page 411)

Appendix L L11
4.2.15 Resize chillers.
4.2.16 Retrofi t with higher coeffi cient of performance (COP) equipment.
4.2.17 Stage multiple chillers.
4.2.18 Use of absorption to reduce electric demand.
4.2.19 Use gas-absorption chillers where appropriate.
4.2.20 Install double-bundle chillers.
4.2.21 Install piggyback (absorption systems).
4.2.22 Reclaim heat from refrigeration system hot gas.
4.2.23 Equipment cooling: Control makeup water and reduce blowdown by adding tempera-
ture control valves to cooling water discharge lines in equipment such as air compres-
sors and refrigeration systems.
4.2.24 Evaporative cooling systems: Consider side stream softening for very large cooling
loads.
4.2.25 Evaporative cooling systems: Install drift eliminators or repair existing equipment.
4.2.26 Evaporative cooling systems: Install softeners for makeup water, side-stream fi ltration
(including nanofi ltration, a form of low-pressure reverse osmosis), and side stream in-
jection of ozone.
4.2.27 Evaporative cooling systems: Install submeters for makeup water and bleed-off water
for equipment such as cooling towers that use large volumes of water.
4.2.28 Evaporative cooling systems control cooling tower bleedoff based on conductivity by
allowing bleedoff within a high and narrow conductivity range. This will achieve high
cycles of concentration in the cooling system and reduce water use in cooling tower.
4.2.29 Use existing cooling towers to provide chilled water instead of using mechanical refrig-
eration for part of the year.
4.2.30 Clean evaporator and condenser surfaces of fouling.
4.2.31 Raise evaporator or lower condenser water temperature.
4.2.32 Optimize chiller sequencing.
4.2.33 Use two-speed or variable-speed fan instead of water bypass to modulate the cooling
tower capacity.
4.3 Compressed Air System
4.3.1 Typically compressed air system is the most expensive form of energy used in industrial
plant—its effi ciency from start to end use is around 10%.
4.3.2 Eliminate air leaks. A typical industrial facility that has not been well maintained could
have a leak rate between 20% and 50%. Leak repair and maintenance program can re-
duce this to less than 10%.
4.3.3 Heat recovery from cooling oil in screw compressors.
4.3.4 Install liquid pressure amplifi er on reciprocating compressor systems.
4.3.5 Reduce compressor speed in over-capacity system.
4.3.6 Replace air compressor and add receivers.
4.3.7 Automate blow-off nozzles on air compressor storage tanks.