Page 136 - Managing Global Warming

Electricity generation in the world of nuclear power industry 101

Fig. 3.29 The largest in the world 18-cylinder Otto cycle natural gas engine (18V50SG)
power-generating unit with output of up to 18.3MW el , 50Hz and 500rpm. The natural gas
fueled, lean-burn, medium-speed engine is a reliable, high-efficiency, and low-pollution power
source for flexible base load, intermediate peaking, and combined-cycle power plants.
Efficiency—48.6%. Dimensions in m: Length: 18.8; width: 5.33; height: 6.34; bore: 500mm;
and weight: 360t. Engine is 4-stroke spark ignition with prechamber.
€
€
Courtesy of WARTSILA, Finland.

Table 3.8 Typical ranges of thermal efficiencies (gross)
of modern thermal power plants [1,2]
Gross
No Thermal power plant Eff. (%)
1 Combined-cycle power plant (combination of Brayton gas-turbine Up to 62
cycle (fuel—natural gas or LNG; combustion-products parameters
at the gas-turbine inlet: T in 1650°C) and Rankine steam-turbine
cycle (steam parameters at the turbine inlet: T in 620°C(T cr ¼374°
C)) (Fig. 3.28)
2 Supercritical-pressure coal-fired power plant (Rankine cycle steam Up to 55
inlet turbine parameters: P in 25–38MPa (P cr ¼22.064MPa),
T in 540–625°C(T cr ¼374°C) and T reheat 540–625°C) (Fig. 3.27)
3 Internal combustion engine generators (Diesel cycle and Otto cycle Up to 50
with natural gas as a fuel (Fig. 3.29))
4 Subcritical pressure coal-fired power plant (older plants) (Rankine Up to 43
cycle steam: P in 17MPa, T in 540°C(T cr ¼374°C) and
T reheat 540°C) (Fig. 3.27A)
5 Concentrated solar thermal power plants with heliostats, solar Up to 30
receiver (heat exchanger) on a tower and molten-salt heat storage
system (Figs. 3.15–3.17)