11.1 Purpose of Treatment. Cooling water must be treated to remove
chemicalcomponents of the water supply that produce deleterious effects in
the diesel-engine cooling systems and allied equipment.
11.2 Choice of Treatment. The choice of treatment, type, and facilities
depends on the cooling system, characteristics of the water supply, chemical
components of the water, and the cost of treatment. This information can be
obtained only by a detailed investigation of the water supply. Water
treatment consultants should be retained to analyze water samples, recommend
types of treatment, and the chemicals required for internal treatment.
11.3 Chemicals and Conversion Factors. For chemicals and conversion
factors used in water treatment systems, refer to the National Water Well
Association (NWWA), Water Conditioning Technical Manual.
11.4.1 Radiator Cooling Circuits. Jacket water and lubricant cooling
systems for diesel engines, in general, should be closed-circuit types
requiring very little makeup water. In radiator type cooling, the same
fluid is usually circulated through the engine jackets, turbocharger
aftercooler, lubricant cooler heat exchanger and fan cooled radiator. In
smaller sized units, the entire engine, generator, cooling radiator,
radiator fan, turbocharger, aftercooler, and connecting piping systems are
all self-contained or packaged on a structural skid-type subbase. When
units are of large capacity, the cooling air quantities become large, and
the radiator units are moved outside the power plant building. In cases of
larger capacity units, the lubricant coolers can be incorporated with the
radiator and become air cooled by the radiator fans. In a marine
environment admiralty metal should be used for radiator construction.
11.4.2 Cooling Systems for Larger Diesel Engines. In general, the engine
cooling circuits remain the closed-circuit type with cooling supplied by an
external radiator, cooling tower, or other source of cooling water. The
primary cooling fluid can be cooling tower water, cooling pond, river water
lake water, sea, or well water. Separating the primary and secondary fluids
by means of heat exchangers is essential to prevent high maintenance costs
concentrations of dissolved salts, solids, and turbidity in natural water
sources can cause these problems. Monitoring and treating cooling tower or
cooling pond makeup water is required to prevent fouling of heat exchangers
are located in windy and dusty locations, the use of cooling water
recirculation filters will improve the reliability of the installation. In
general, were ambient temperature conditions are suitable, dry-type radiator
(air) cooling provides the most trouble and maintenance-free type of system.
The need for only small amounts of water to make up that lost by expansion
tank evaporation reduces the need for extensive water treatment systems.