Gas Turbine Integrated (GTI) Storage addresses the operational
issues of Combined Cycle Gas Turbines (CCGT), by allowing
for faster ramping, greater turndown and time shifting of power production
GTI-Storage system is based on the process of extraction, storage and subsequent reinjection of hot compressed air into a gas turbine. Air extraction and air injection has been used in gas turbines in the past and this system utilises this process, but with the addition of the Isentropic
Thermal Store to enhance flexibility and efficiency.
A conventional gas turbine
In a conventional gas turbine air is drawn through the compressor, fuel is added to the mixture and the products of combustion all pass through the turbine. Power is used to turn the compressor but a greater amount is produced by the turbine. The difference is the net shaft power, which is used to drive an electrical generator. (Typically the turbine power is around twice that of the compressor).
GTI-Storage system includes the following components:
- CCGT (new or existing)
- Thermal stores (in particular, the patented Isentropic
- An additional compressor for pumping up to the 250 bar storage pressure
- Pressurised steel pipe designed to store compressed air at high pressure
With GTI-Storage, air is injected into or bled from the gas turbine just before the combustor. This allows hot, pressurised air from the compressor to be stored and fed back into the gas turbine at a later time. By controlling the bleed or injection rate the output power of the turbine can be varied significantly.
Charge Mode Discharge Mode
By bleeding some air to the Air & Injection of stored air supplements the
Heat Storage unit, less air is passed flow to the combustor, increasing fuel
through the combustor and so the burn and leading to an increase in the
power output of the turbine is reduced. power output of the system.
Note that when charging or discharging the reduction or increase in the power output is greater than the storage power. The gas turbine has an amplifying effect
on the stored power.