Power Plant #8 (PP8)

Stellar Energy designed and built a turbine inlet air chilling (TIAC) system to increase power output during off-peak consumption times and store the energy to be used during the daily six-hour peak consumption period. The project included an office, a machine room, TIAC coils, a filter house retrofit and a thermal energy storage tank.

Project Challenge

Saudi Electric Company’s requirement was to increase power generation from 10 Frame 7 gas turbines to meet peak electrical demand during the summer. Because of water limitations in the region, the system was required to be air-cooled and operate on a design day temperature of 122°F (50°C).

Project Solution

Stellar Energy provided engineering, construction management and equipment procurement and supply for the project which included an office, machine room, turbine inlet chilling coils, filter house retrofit and a thermal energy storage tank. The 30,000 cooling load is satisfied with an 11,000 TR chilling plant and a 195,000 TR-HR Thermal Energy Storage (TES) tank. At the time of completion, this TES tank had the largest stored TR-HR capacity in the world. It allows the chiller plant to be sized to one-third of the cooling load requirement. The chiller plant is air-cooled with large fan-cooled radiators.

The Thermal Energy Storage tank is charged with chilled water during off-peak hours using compound centrifugal chillers. During peak hours, when power is most needed, the chillers are turned off and the chilled water in the tank is pumped to the cooling coils to reduce inlet air temperature and increase power output.

Result

Project delivered on time and on budget, met all the specified project requirements, and the system increased total plant output by 25%, or 160 MW.