COVER-BRAKE VALVE 7K6116 - Caterpillar

The control strategy for the G3600 will adjust the air/fuel ratio. That adjustment is determined by the BTU setting, the fuel flow, and the combustion burn times. The BTU setting is the initial setting of the air/fuel ratio. The combustion burn time measurement allows the control strategy to fine tune the air/fuel ratio. This is based on the quality of the fuel. Both of these adjustments are critical, and problems can arise if the adjustments are not properly set.BTU Setting
The BTU setting on the G3600 engine is typically defined during the engine commissioning process. The BTU setting should only be readjusted when the average lower heating value of the fuel changes. The process involved for properly establishing the BTU setting on a G3600 engine requires both a gas analysis and a emission measurement. A gas analysis is required before making any BTU adjustments on the engine. The analysis defines the lower heating value (LHV) of the fuel. Refer to the Methane Program, LEKQ4196 in order to calculate the lower heating value (LHV). This program establishes the lower heating value through a calculation that weighs the effect of the various contents of the gas. This calculation is based on the percentage of the total gas. The engine should be tuned to this lower heating value (LHV). An emission measurement should be made in order to verify that the G3600 is properly set. The emission levels of the BTU setting can be compared to the following levels that were recorded during the engine commissioning.
NO
NOx
CO
CO2
O2If the amount of NOx and CO that is in the exhaust are not within 10 ppm of the values established during the engine commissioning, then a determination must be made if the BTU setting should be adjusted. A leaner air/fuel ratio will reduce NOx and a leaner air/fuel ratio will increase CO. A richer air/fuel ratio will increase NOx and a richer air/fuel ratio will reduce CO. Two basic concepts of the control strategy must be understood before making an adjustment to the BTU.Basic G3600 Engine Speed And Governing Control
The G3600 engine's control strategy adjusts fuel flow. This is based on the differential between the actual engine speed and the desired engine speed setting.If the actual engine speed is lower than the desired engine speed, then the control strategy will increase the amount of fuel flow to the combustion process. If the actual engine speed is higher than the desired engine speed, then the control strategy will decrease the amount of fuel flow to the combustion process. The application of load to the engine will result in a higher fuel flow in order to maintain the same desired speed. This is because the actual engine speed will decrease as the load is increased.Basic G3600 Air/Fuel Ratio Control
The control strategy of the G3600 uses the volume of fuel that is supplied to the combustion process and the engines heating value to determine the amount of air that is required in order to maintain the proper air/fuel