Cooling water circuit

Closed Air Circuit Water Cooled (CACW) The motor s interior hot air forms one part of the closed air circuit that is circulated by the motor s internal fans. A separate heat exchanger is mounted on top of the motor as the cooling water circuit. This forms the second cooling circuit. 

Chemical consumption Chemical consumption will be associated with boiler feed make-up water-treatment plant, dosing systems for feedwater and boiler system, treatment of cooling water circuits and effluent treatment. Typical chemical requirements for a thermal power plant are given in Table 15.9. 

Miscellaneous There are many interesting applications that arise from time to time that are outside the main stream of industry described above. Examples include desalination plant reactor cooling water circuits automobile body corrosion in situ) marine (vessels, piling, harbour installations) aircraft (in situ) packaging and cavitation monitoring. 

In some instances (e.g. cooling water circuits), chemicals can be added to the heat transfer fluids to inhibit fouling. The chemicals added to inhibit fouling and the means of cleaning depend on the nature of the fouling. Fouling can be classified as ... 

Improving control of cooling tower blowdown (see Chapter 24) for evaporative cooling water circuits to increase the cycles of concentration and reduce the cooling tower blowdown rate. 

Check that pipeline tappings for temperature and pressure measurements are htted on chilled water and cooling water circuits. 

Use of plate exchangers to exchange process heat with cooling water circuit. 

Cooling water circuits can be controlled from an outside stand. 

The cooling water circuit provides river water (at 20°C) to the steam condenser and compressor intercooler. The use of stainless... 

NONE No Flow 1. Pump failure. 2. Valve fails shut. 3. Line fracture. High emissions of NOx in tail gas. As for. Valve overheats. AS for I and 2. a) Install HIGH LEVEL ALARM on TIC on the tail-gas outlet line to indicate high emissions. Covered by a). b) Install kick-back on pumps. Covered by a) and b). C) Regular inspection and patrolling of cooling-water circuit lines and associated seals. 

The design specification for the absorber requires that the tail gas leaves the absorber at 1 0°C, make-up water to be supplied at 7°C to the top plate, and inclusion of two independent sets of cooling coils in the column. The first set of coils runs in the top half of the column. The inlet temperature for these coils is 7°C and the design exit temperature is 20°C. The second set of coils occupy the bottom half of the column using cooling water from the normal cooling-water circuit. Therefore, the inlet temperature is 20°C, and the outlet temperature is 40°C. 

The deionized cooling-water circuit has a dual role. First, it provides process make-up water. Second, water, is circulated from within this loop for cooling. The cooler/condenser and lower cooling coils in the absorption column must both use deionized water as the cooling medium because of the prerequisite use of stainless steel in this section of the plant. 

The cooling-water circuit provides cooling water for the steam condenser and for the compressor intercooler. Since these units are constructed from mild steel, the cooling water used can be either sea water, river water or scheme water. Probably the second option is best because there are no further equipment materials requirements and this water is free. The total circulation through this cooling-water loop is approximately 120 000 kg (120 cubic metres). 

To prevent or reduce the risk of robust crystalline structures forming on heat-transfer surfaces, it is helpful to employ a crystal modifier. The action of these chemical compounds is to interfere with the crystal structure, so that the scale is more susceptible to the removal forces created by the liquid flow across the deposit. Crystal modifiers including polymaleic acid are widely used in cooling water circuits. 

These studies allowed the development of corrosion probes with high sensitivity and reliability. They have been applied on steam condensers [10] and cooling water circuits [11]. 

It is valuable to provide connections on the cooling water system, that may be used for flushing to dislodge any accumulations of deposits that might occur. The opportunity to isolate heat exchangers by the inclusion of bypass systems, must be included so that off-line cleaning can be carried out without the need to shut down whole sections of the total cooling water circuit. 

FIGURE 16.3. Simplified flow sheet of a power station cooling water circuit using chemical additives... 

SPRAY-COOLING CIRCUIT - An open cooling-water circuit which sprays water and cools by evaporation, for example, a cooling tower, all evaporative condenser, an air washer, or a spray-coil unit. 

The test operation of the HHV showed that monitors were necessary in order to ensure that the cooling water flows in each of the approximately 50 cooling water circuits. Moreover operationing experience showed the need for a hydrocarbon detector and for adequate interlocking in the sealing oil lubrication systems. 

A failure of a conductivity meter on the cooling water circuit of an alternator led to the shutdown of the corresponding turbo-generator set on January 7, thus validating the procedure involving switching the load from one generator set to another. 

The leaching reactions are exothermal. Temperature in the autoclave is kept at about 140-160 with cooling coils (closed cooling water circuit) and the pressure is 15-16 bar. The autoclave vent gases are directed to the gas scrubbing system. 

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