Patent ID: 11898429
Assignee: BJ ENERGY SOLUTIONS, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC E  F | IPC E  F

Claim 0:
1. A hydraulic fracturing unit assembly to pump a fracturing fluid into a wellhead, the hydraulic fracturing unit assembly comprising:
a gas turbine engine including:
a compressor, a combustor section positioned to receive compressed air from the compressor, a compressor turbine connected to the compressor such that the compressor turbine rotates with the compressor at a first rotational speed, and a power turbine positioned such that heated combustion gas output from the combustor section causes the power turbine to rotate at a second rotational speed;
a transmission including:
an input shaft connected to the power turbine such that the input shaft rotates at the second rotational speed, and an output shaft positioned to be driven by the input shaft at a third rotational speed;
a hydraulic fracturing pump positioned to pump fracturing fluid into the wellhead, the hydraulic fracturing pump connected to the output shaft;
a brake assembly configured to at least partially control the second rotational speed of the power turbine independent from the first rotational speed of the compressor turbine; and
a fracturing unit controller configured to:
control one or more of the first rotational speed, the second rotational speed, or the third rotational speed based at least in part on one or more of a target pressure or a target flow rate associated with fracturing fluid pumped into the wellhead, and generate one or more brake control signals configured to at least partially control operation of the brake assembly; and
generate one or more idle signals to cause a starter assembly of the gas turbine engine to cause the compressor and the compressor turbine to rotate at a target idle speed while the power turbine remains at zero rotational speed.