8 7 6 5 4 3 2 1

10_RP01:B5.BO01

Turbine MSV Closed

H HP BP Average Demand H/ x BO01 H

Turbine RSV Closed BO02 BO03

LP BP Average Demand H/ x
10LP01:B4.RO01 2.5%
DB:2
G G

10_RP01:B5.BO03
M6
BO07
Turbine Tripped

BI6
S x Loss of Reheat Protection
R 50sec 10_RP01:B4.BO08

F x F

x 60sec BO07

10_RP01:B4.RO01
∑ H/

242T/H
DB:2
E f(x1) E
0~100
BI7

10_FA02:B5.RO01

Total Fuel Flow[%] H/

30T/H
DB:2
D D
10MAA10_2TX1:B106.PNT
10FWCS_10:B1.OUT
Turbine First Stage Pressure f(x2) H/

242T/H
DB:2

Reheater Protection
C C
Stopping or significantly reducing steam flow through the reheater when the entering gas temperature is above 1000℉
(538℃) can cause overheating and damage to the reheater tubing. To prevent this condition, the following
measures are taken with the automatic reheat protection interlocks:

RH FLOW MONITORING
If excessive steam flow is extracted upstream of the reheater, causing flow through the reheater to be dangerously low,
all fuel should be tripped automatically with a maximum time delay of 10 seconds. Extreme care should be exercised
when bringing in feedwater heaters or when extracting auxiliary steam from the cold reheat lines.
B B
TURBINE VALVE CLOSURE
If a loss of load should cause the turbine valves to close, the HP/LP bypass stations will automatically open to allow the
boiler to stay on-line. If the HP/LP bypass stations do not open within 10 seconds to provide a flow path through the
superheater and reheater, all fuel should be tripped.

TURBINE TRIP
If a loss of load occurs in which the turbine is tripped, the HP/LP bypass stations will automatically open to
provide a steam flow path for the superheater and reheater, allowing the boiler to stay on-line.
A A
Made by Date
C&I TA, KOSEP 2011-06-07
Title
Loss of Reheat Protection
8 7 6 5 4 3 2 1