【文章內(nèi)容簡(jiǎn)介】 ondenser is subject to the conditions specified in the heat transfer calculation sheet. It is particularly important that the steam pressure is maintained as specified, since lowering the pressure may cause excessive inlet velocity which may be both noisy and harmful to the condenser, as well as the lower pressure will decrease the thermal performance. Usually it will be sufficient to evaluate the performance of the condenser by monitoring the outlet temperature of either the condensate or the water outlet temperature . If the condensate temperature is too high or the sea water outlet temperature is too low, either the condenser needs cleaning or the operating parameters are incorrect. Check the operating conditions and take appropriate corrective action to bring the performance back to the required level. Conservation during shut down periods Corrosion occurrences in shut down periods are mainly caused by oxygen. The corrosion occurs if nondistilled, alkaline or sea water remains in the condenser. However, even when fully emptied, the condenser is exposed to corrosion caused by water residues or condensation. Hence, when out of service, it should be protected against corrosion by flushing with fresh water on the sea water side and carefully draining of both sides. If the condenser is out of service for an extended period of time – in particular during winter seasons with frost – it must be carefully emptied. Open the air vent valve and check for clogging. Maintenance and cleaning The condenser should be cleaned regularly by removing the tube insert every twelve months or at any time there is a decrease in output not related to other causes. STEP A： Check if any deposits have collected in the water boxes or in/on the tubes. ***：輪機(jī)工程專業(yè) 英文翻譯 8 STEP B： Cleaning of the tube bundle from the outside is carried out after removing the tube insert using a liquid jet STEP C： Cleaning of the tube bundle from the inside is carried out after removing the cover by flushing the tubes with . citric acid. To remove scales or impurities a soft nylon brush can be used, but it is very important not to damage the tube surface during mechanical cleaning. STEP D： Once every year the safety valve must be checked for correct set point. Dismantling and reassembling of the tube bundle When the tube bundle must be pulled from the condenser, the sea water connections must be dismantled and the water boxes at the steam inlet removed. Loosen the bolts for the other water box and use the jacking bolts in the water box to pull the water box off the tight Oring fitting with the tube sheet. Protect the floating end tube sheet packing surface with a wrap of tape before pulling the bundle. Handle the bundle and water boxes with care, since both tubes and packing surfaces can be damaged by impact. Inspect the tube bundle, water boxes and the shell for damage and excessive wear, make necessary repairs and cleaning and reassemble the condenser. Fit new Orings to the floating end water box gasket grooves and grease with heat resistant silicone grease to ease the mounting and increase the gasket life time. Mount the bundle in the shell and remember to protect the packing surface of the tube sheet before inserting the bundle. It is extremely important that the impingement plate is facing the steam inlet nozzle, otherwise the tubes may fail prematurely due to erosion. Mount the fixed end water box. Remove the protective tape from the floating end tube sheet and gently slide the floating head water box on. Use the flange bolts to ensure a proper fitting without yawing of the water box. Set up the piping again and tighten all bolts. Gasket surfaces must be cleaned and protected against damage. New gaskets should be fitted every time a connection has been dismantled. To ensure a tight fit only original spares should be used when replacing the gaskets and Orings. Always use a torque wrench when tightening the flange bolts. Operate the condenser for one hour, stop, and retighten all bolts A pressure test should be carried out to prove tight joints. Both sides of the condenser must be carefully vented and the circuits carefully inspected for leakage during the whole startup period. Spare parts When ordering spare parts ple