|Minimum Order Quantity||50 Meter|
|Type Of End||Plain End|
Many large buildings, campuses, and other facilities have plants that make chilled water and distribute it to air handling units and other cooling equipment. The design operation and maintenance of these chilled water plants has a very large impact on building energy use and energy operating cost.
Not only do chilled water plants use very significant amounts of electricity (as well as gas in some cases), they also significantly contribute to the peak load of buildings. The utility grid in many other areas of the country, experiences its maximum peak on hot summer days. During this peak event, chilled water plants are often running at maximum capacity. When temperatures are moderate, chilled water plants are shut down or operated in stand-by mode. This variation in the rate of energy use is a major contributor to the peaks and valleys in energy demand, which is one of the problems that must be addressed by utility grid managers.
Most buildings and facilities that have chilled water plants have special utility rates where the cost of electricity depends on when it is used and the maximum rate of use. For instance, PG&E has five time charge periods: summer on-peak, summer mid-peak, summer off-peak, winter mid-peak and winter off-peak.
In addition to new construction, the chilled water plants of many existing buildings are being replaced or overhauled. Older chilled water plants have equipment that uses ozone-damaging refrigerants. International treaties, in particular the Montreal Protocol, call for ozone damaging chemicals (in particular CFCs) to be phased out of production. As the availability of CFCs is reduced.
2) Loads_ discusses the nature of chilled water loads and how they should be considered in the design of chilled water plants. In the past, most engineers have only estimated the peak or maximum load; however, accounting for the time pattern of loads can be just as important. It is also important to anticipate future growth in load and to build in excess capacity when appropriate. Methods of calculating peak loads and hourly loads are reviewed. These include site measurements (for existing facilities), computer simulations, rules of thumb and prototype buildings.
3) Equipment_ reviews some basics on chillers, cooling towers, pumps, and other plant equipment. The chapter discusses the basic refrigeration cycle; water chillers; cooling towers; air-cooled condensers; and pumps.
4) Systems_ discusses different ways of arranging chilled water equipment in the system to achieve energy efficiency and operational simplicity. The pros and cons of constant flow and variable flow systems are discussed along with different primary only and primary/secondary pumping systems. Other topics include interconnecting multiple chilled water plants and heat recovery chillers.
5) Design_ provides procedures and analysis techniques for optimizing chilled water plant design. Topics include optimizing the size and selection of the chillers and other plant components and the sequencing of the chiller plant equipment. A design approach is recommended which combines detailed analysis and rule-of-thumb recommendations. This approach will achieve better results than traditional design procedures.
6) Procurement_ discusses strategies for procuring chilled water plant design and construction services. It also recommends specific procedures for evaluating chiller options and selecting an energy-efficient and cost-effective chiller. A sample chiller bid specification and a sample chiller bid form are also provided.
7) Commissioning_ provides an overview of the commissioning process. This overview is followed by a discussion of the commissioning phases for a typical chilled water plant, from the development of the commissioning program to post occupancy commissioning activities.