Additional high pressure heater after high pressure boiler feed pump procedure, the feed water heating can effectively reduce heat loss caused by cooling water in condenser, in order to increase feed water temperature that impacts on coal consumption saving and improve economic performance. Heat exchanger tubes is core component of the device, tubing types including U-tube and π-tube and straight tube etc.
Straight tubes mainly applied on fixed tube sheet exchanger, that tube row and shell are fully connected, the structure is simpler that only applicable to small temperature difference between the hot and cold fluids, and shell side operate without heat exchange procedure during mechanical cleaning. Elastic compensation ring can be installed on shell when temperature difference is large and pressure is not high enough, in order to reduce the thermal stress.
Main steel grades:
ASME SA-556M Seamless cold drawn carbon steel tube for feed water heater
GB/T 24591-2009 Seamless steel tubes for high pressure feed water heater
Super length( maximum up to 35 meters or more), Thin(length-diameter ratio>1000), High straightness requirement (full length ring gauge examination with max tolerance ＋0.02mm), High surface roughness requirement, and high resistance to corrosion due to product operating environment.
Product operating environment
Operating temperature of seamless steel straight tubes for high pressure feed water heater is over 350℃ (based on boiler unit capacity), operating pressure is 30MPa or more, also to withstand 3m / S or more high velocity flow and vibration of the inner tube, product reliability requirement are very high due to extreme service condition, that requires the tube service life of 15 years or more.