Regenerative heating of feedwater is essential to enhancing the efficiency of the power cycle. The feedwater is heated to the maximum permissible extent in a feedwater heater using controlled or uncontrolled extraction from the steam turbine.

LP Feedwater Heater

HP Feedwater Heater

The Power Plants Components Division (PPCD) provides high and low pressure feedwater heaters to the power industry for steam turbine applications ranging from 10 MW to 1500 MW.

Depending on the requirements the heaters can be designed as horizontal, vertical, channel up, channel down, one zone, two zone, three zone, duplex or a combination thereof. The channel closure for high pressure feedwater heaters could be, cup forging with bolt cover, pressure seal, breech lock or hemi-head/manway closure.

Proper distribution of steam inside the shell, prevention of damage to heater internals from incoming extraction steam and flashing drains, proper setting of condensate levels, prevention of steam ingress into the subcooling zone, lower snorkel and snorkel inlet velocity, elimination of flashing in subcooling zone, and effective venting of tube bundles, are some of the characteristics that enhance the performance and dependability of Holtec low pressure (LP) feedwater heaters.

HP Feedwater HeatersThe distinguishing characteristics of Holtec high pressure (HP) feedwater heaters, in additional to those highlighted above for low pressure heaters, are longitudinal flow and accompanying low pressure drop in desuperheating zone, specified minimum dry wall margin at various operating conditions, flawless zone boundary welds, and absence of flow induced vibration in all zones of the heater.

None of the Holtec heaters supplied to the power generating industry in the past twenty years has suffered damages from flow induced vibration.

HP Feedwater HeaterHigh temperatures, high pressures, a variety of operating scenarios mandate a thorough analysis of stresses in critical locations of the heater. One such critical location is the knuckle radius in the cup forging of a high pressure heater. Critical sections of the feedwater heater are designed using the state-of-the-art finite element methods.

Flow distribution in all zones of the heater is studied using the conventional as well as the computational fluid dynamics programs. The advanced analysis such as CFD (Fluent) and finite analysis (ANSYS) are usually performed by the experts from the Holtec Technical Services Division.

CFD Solution for a HP HeaterThe conventional, complex and innovative heater design concepts are captured in the proprietary heater program, “HEATER”. The versatile heater code permits the Holtec engineering team to develop thermal, mechanical, hydraulic, vibration and other related designs expeditiously to meet the proposal and project deadlines.

Holtec heaters are fabricated by the Holtec Manufacturing Division (HMD) and by Holtec fabricating partners in North America and Asia. All of the fabrication facilities have ASME Section VIII code stamps (“U” and “R”) and sterling credentials for quality fabrication and on time delivery.

The fabrication is in strict accordance with Holtec quality standards, client’s requirements and applicable codes. State of the art fabrication techniques, a skilled workforce, and comprehensive quality assurance programs guarantee reliable, accurate and on time fabrication of Holtec heaters.