White Paper

• Ten tips for improving chiller efficiency – Richard Grenz

  “Heat transfer has the greatest single effect on chiller performance. Large chillers can have more than five miles of condenser and evaporator tubes, so high heat transfer is fundamental to maintaining efficiency. Chiller efficiency declines rapidly when tubes become fouled. Contaminants, such as minerals, scale, mud, algae and other impurities, increase thermal resistance and reduce overall performance. These contaminants accumulate on the water side of heat transfer surfaces in both closed- and open-loop systems. Fouling occurs gradually over time, depending on the quality and temperature of the water used.”
  http://www.plantservices.com/articles/2004/192.html
  

• FacilitiesNet – Chiller Challenge Energy Efficiency

  Purchasing the most efficient chiller is only the first step in minimizing energy costs. Once installed, an organization must maintain the chiller properly if it is to perform as efficiently as possible. In most cases, any savings produced by cutting back on chiller maintenance will be more than offset by increased energy costs… Another critical ongoing maintenance task is properly treating water in both the chilled-water and condenser-water loops to prevent scale, corrosion and biological growth. Any accumulation of these contaminants will result in a rapid decrease in operating efficiency”.
  http://www.facilitiesnet.com/ms/article.asp?id=4303
  

• Solutions to fouling in power station condensers

  “Fouling is a very important problem for condensers and heat exchangers. All industrial circuits cooled with natural fresh and marine water are affected by the phenomenon of biological fouling consisting in biofilm growth and settlements of several kinds of living organisms. Biofouling is detrimental to open cooling systems as it causes undesirable effects, such as efficiency loss inside the heat exchanger”,
  

• Fouling characteristics of internal helical-rib roughness tubes using low-velocity cooling tower water

  “This paper provides long-term cooling tower water fouling data in seven 15.54 mm I.D. copper, helically ribbed tubes taken at low water velocity (1.07 m/s). The ranges of geometric parameters were number of rib starts (18–45), helix angle (25–45_), and height (0.33–0.55 mm). These geometries provide a new class of internal enhancement that is typical of commercially enhanced tubes presently used in water chillers”.
  

• Carry Out Maintenance Procedures

  “Online cleaning has the greatest potential advantage for a plant owner…Mechanical techniques include methods such as injecting rubber balls into the cooling fluid upstream of the heat exchanger and collecting them downstream in a special filter”