SPP-BOILER drum unit · mechanics & protection

JV_PSPP_TEST / SPP-BOILERHARAIEC 61508 · SIL 2

t 0.00 s

Unit mimic

Running

Trends

limittrip set point

Drum pressure bar

Drum level mmtrue2oo3 DP median

Turbine speed % rated

Unburnt fuel in furnace kg

Safety goals

this run

Goal	Limit	Run extreme

Sequence of events

Model parameters (SPP-ASM-01) and simulation assumptions

MCR steam 100 kg/s; drum design 140 bar, normal 135 bar; SG-01 limit 154 bar
Pressure storage 60 kg/bar (lumped water + metal); level sensitivity 15 kg/mm
Normal level 0 mm; LL trip −250 mm; HH trip +250 mm; carry-over +300 mm; tube exposure −600 mm
Residual heat after fuel trip decays with τ = 8 s; turbine-generator H = 4 s
Stop valve closure 0.3 s (adjustable); overspeed trip at 110 %
2 safety valves, set 150 bar, 3 % accumulation, 4 % blowdown, 110 kg/s total
Trip response times used: pressure 0.5 s, level 1.5 s, flame 3 s, overspeed 0.05 s (all inside the FSR budgets)

Sim-only assumptions, not in WCGW: a boiler trip also trips the turbine; a reverse-power relay opens the breaker 1 s after steam is lost; level control is three-element and uses the DP median; drained reference leg biases DP channels +450 mm; conductivity electrodes every 50 mm; 2.5 kg/s fuel per burner, unburnt fuel swept out with τ = 3 s, explosive accumulation limit 25 kg; tube metal creep limit 480 °C; feed pump runout 160 kg/s.

Lumped-parameter sketch built from work item SPP-BOILER in WCGW. Illustrative numbers only, not real project data, and not a substitute for a validated plant model.