Automated Grate Shaking


 

Pressure at Combustion (P_comb)

Pressure at combustion is measured at or near the air nozzles inside the reactor. P_comb can be measured using the ignition port tube that extends close to the air nozzles in the V3/V4 GEK reactors. P_comb provides a rough measure of gas flow rate, independent of packing of the reduction bell with ash and fines.

 

Scatter plot of P_comb vs. real power. Data from 10 hour run on 2010/06/05.

 

Data taken from running the Power Pallet over ten hours shows that pressure at combustion relates to energy output from the generator. As more gas is consumed by the engine, more air is drawn into the reactor. The amount of air needed per unit of gas output remains roughly constant. The pressure at combustion is lowered as more air is needed to meet demand. The pressure ratio method of detecting bed packing works by normalizing the reactor pressure to this pressure, making the pressure ratio largely independent of gas flow rates.

 

Pressure of the Reactor (P_reactor)

Pressure of the reactor is measured at the manometer bung on all GEK gas cowlings. This pressure measurement location is below the reduction bell, so includes both the effect of the air nozzle pressure drop (P_comb) and pressure drop across the reduction bell (P_reactor - P_comb).

 

Pressure Ratio (P_comb/P_reactor)

Pressure ratio readings during a period from multi-fuel runs during summer 2009. Vertical bars grate shaking events, every 2 minutes. Grate was an automated V3 rotary grate. Pressure ratio increases during each shake event, showing a clearing of the reduction zone.

Pressure ratio plots from grate shake testing June 2010 on V4 GEK using vibratory and crank based automated shaking.