2.2.6 Effect of Seasonal Weather Variations on Cooling Pond
Requirements and Performance
The equilibrium temperature, E, for most locations inside the continental USA
reaches a low in early January and then reaches a high six months later in early
July. The pattern of variation of E is actually quite smooth for most locations. The
difference between seasonal high and low is more distinct at more northern (higher
latitude) locations [4].
The surface heat exchange coefficient, K, varies in a relatively inversely proportional relationship to “E.” Highest heat exchange coefficients are realized in summer,
lowest in winter. The variation of “K” is not as regular as the variation “E” as the
result of seasonal wind variations. As a result, the maximum value of “K” occurs in
some locations (coastal, mountains, etc.) at times of the year other than mid-summer.
2.2.7 Effect of Geographic Location on Cooling Pond Performance
As mentioned above, geographic locations will affect both “E” and “K.” At higher
latitudes, solar radiation is reduced and significantly affects the equilibrium temperature of a cooling pond. Topography (hills, flat plain, etc.) will influence predominant wind speeds as well as wet bulb temperature and hence influence K. As a result,
within the continental USA, the best conditions for cooling pond performance exist
in the southern Great Plains between the Mississippi River and the Rocky Mountains
(Kansas, Oklahoma, north Texas, eastern Colorado, etc.). Favorable conditions for
cooling pond performance also exist along the Atlantic seaboard between Cape Cod
and the Gulf of Mexico. Poor conditions for cooling pond performance will be found
in the Great Basin region between the Rocky and Sierra Nevada Mountains (Nevada
and Utah). It should be stressed that local “micro-climate” and local topographic
conditions must be considered when determining cooling pond performance [4].
2.2.8 Other Factors Related to Cooling Pond Design
Topics pertinent to the design of cooling ponds are the following.
Dikes and Baffles
A cooling pond has traditionally been constructed by building dikes and/or other
embankments to form a man-made pond. Therefore, cooling ponds are normally
constructed where the local topography is amenable to such construction. If a pond
must be excavated, construction costs will escalate [4].
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Y.-T. Hung et al.
Requirements and Performance
The equilibrium temperature, E, for most locations inside the continental USA
reaches a low in early January and then reaches a high six months later in early
July. The pattern of variation of E is actually quite smooth for most locations. The
difference between seasonal high and low is more distinct at more northern (higher
latitude) locations [4].
The surface heat exchange coefficient, K, varies in a relatively inversely proportional relationship to “E.” Highest heat exchange coefficients are realized in summer,
lowest in winter. The variation of “K” is not as regular as the variation “E” as the
result of seasonal wind variations. As a result, the maximum value of “K” occurs in
some locations (coastal, mountains, etc.) at times of the year other than mid-summer.
2.2.7 Effect of Geographic Location on Cooling Pond Performance
As mentioned above, geographic locations will affect both “E” and “K.” At higher
latitudes, solar radiation is reduced and significantly affects the equilibrium temperature of a cooling pond. Topography (hills, flat plain, etc.) will influence predominant wind speeds as well as wet bulb temperature and hence influence K. As a result,
within the continental USA, the best conditions for cooling pond performance exist
in the southern Great Plains between the Mississippi River and the Rocky Mountains
(Kansas, Oklahoma, north Texas, eastern Colorado, etc.). Favorable conditions for
cooling pond performance also exist along the Atlantic seaboard between Cape Cod
and the Gulf of Mexico. Poor conditions for cooling pond performance will be found
in the Great Basin region between the Rocky and Sierra Nevada Mountains (Nevada
and Utah). It should be stressed that local “micro-climate” and local topographic
conditions must be considered when determining cooling pond performance [4].
2.2.8 Other Factors Related to Cooling Pond Design
Topics pertinent to the design of cooling ponds are the following.
Dikes and Baffles
A cooling pond has traditionally been constructed by building dikes and/or other
embankments to form a man-made pond. Therefore, cooling ponds are normally
constructed where the local topography is amenable to such construction. If a pond
must be excavated, construction costs will escalate [4].
210
Y.-T. Hung et al.