Abstract Thermal pollution is produced by industries such as electric power plants,
pulp and paper mills, chemical facilities, and other process industries that use water
and subsequently discharge water with elevated temperature. The receiving streams,
rivers, lakes, and other waters can dramatically alter the native environment. Often,
elevated water temperature will be detrimental to native species of plants and
animals. As water warms, the solubility of oxygen decreases. In addition to promoting competitive species of plants and animals, warmed waters may lead to aesthetic
and odor problems if anaerobic conditions are created. For these and many other
reasons, the discharge of warm process water is widely regulated by governmental
agencies in developed nations. The authors introduce both cooling ponds and
cooling towers in detailed. The cooling pond topics covered are mechanism of
heat dissipation, cooling pond types and design, completely mixed cooling,
recirculation cooling, surface temperature prediction, longitudinal mixing, heat
dissipation evaluation, once-through cooling ponds, seasonal weather variation,
pond location, cooling, etc. The cooling tower topics covered are mechanism of
cooling tower’s heat dissipation, cooling tower types and designs, natural draft
atmospheric cooling towers, natural-draft wet hyperbolic cooling towers, design
examples, hybrid draft cooling towers, induced, mechanical or forced wet cooling
towers, cooling tower performance, operational problems and solutions, and reuse of
thermal discharge.
Keywords Cooling ponds · Cooling towers · Reuse of thermal discharges · Heat
dissipation mechanism · Types of cooling ponds · Types of cooling towers · Design ·
Surface heat transfer · performance · Natural draft atmospheric cooling towers ·
Natural-draft wet hyperbolic cooling towers
Nomenclature
a
contact area/tower volume, 1/ft or 1/m
A
surface area of pond, ft or m
2
β
slope of the saturated vapor pressure curve between the dew point
temperature and the pond surface temperature, mm Hg
C
C1
Bowen’s conduction-evaporation coefficient, 0.468 mm Hg
C
C p
specific heat of water, 1.0 cal/g
C
d
average depth of flow path, ft or m
dq t /dt
net rate of surface heat exchange, kcal/m
2 d
E
equilibrium temperature,
C
E
equilibrium temperature of the pond at zero added heat load,
C
e a
air vapor pressure, mm Hg
e s
saturated vapor pressure of water at pond surface, mm Hg
f(U )
evaporative wind speed function, Kcal/d-m
2 -mm Hg
h a
enthalpy of air-water vapor mixture at wet bulb temperature, J /kg dry air
or Btu/lb dry air
196
Y.-T. Hung et al.
pulp and paper mills, chemical facilities, and other process industries that use water
and subsequently discharge water with elevated temperature. The receiving streams,
rivers, lakes, and other waters can dramatically alter the native environment. Often,
elevated water temperature will be detrimental to native species of plants and
animals. As water warms, the solubility of oxygen decreases. In addition to promoting competitive species of plants and animals, warmed waters may lead to aesthetic
and odor problems if anaerobic conditions are created. For these and many other
reasons, the discharge of warm process water is widely regulated by governmental
agencies in developed nations. The authors introduce both cooling ponds and
cooling towers in detailed. The cooling pond topics covered are mechanism of
heat dissipation, cooling pond types and design, completely mixed cooling,
recirculation cooling, surface temperature prediction, longitudinal mixing, heat
dissipation evaluation, once-through cooling ponds, seasonal weather variation,
pond location, cooling, etc. The cooling tower topics covered are mechanism of
cooling tower’s heat dissipation, cooling tower types and designs, natural draft
atmospheric cooling towers, natural-draft wet hyperbolic cooling towers, design
examples, hybrid draft cooling towers, induced, mechanical or forced wet cooling
towers, cooling tower performance, operational problems and solutions, and reuse of
thermal discharge.
Keywords Cooling ponds · Cooling towers · Reuse of thermal discharges · Heat
dissipation mechanism · Types of cooling ponds · Types of cooling towers · Design ·
Surface heat transfer · performance · Natural draft atmospheric cooling towers ·
Natural-draft wet hyperbolic cooling towers
Nomenclature
a
contact area/tower volume, 1/ft or 1/m
A
surface area of pond, ft or m
2
β
slope of the saturated vapor pressure curve between the dew point
temperature and the pond surface temperature, mm Hg
C
C1
Bowen’s conduction-evaporation coefficient, 0.468 mm Hg
C
C p
specific heat of water, 1.0 cal/g
C
d
average depth of flow path, ft or m
dq t /dt
net rate of surface heat exchange, kcal/m
2 d
E
equilibrium temperature,
C
E
equilibrium temperature of the pond at zero added heat load,
C
e a
air vapor pressure, mm Hg
e s
saturated vapor pressure of water at pond surface, mm Hg
f(U )
evaporative wind speed function, Kcal/d-m
2 -mm Hg
h a
enthalpy of air-water vapor mixture at wet bulb temperature, J /kg dry air
or Btu/lb dry air
196
Y.-T. Hung et al.