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

Claim 23:
24. A hydraulic fracturing unit assembly comprising:
a chassis;
a gas turbine engine connected to the chassis, the gas turbine engine including:
a compressor positioned to compress air, a starter assembly connected to the compressor, a compressor turbine connected to the compressor such that the compressor turbine and the compressor rotate a first rotational speed, and a power turbine positioned such that heated combustion gas causes the power turbine to rotate at a second rotational speed;
a brake assembly to prevent rotation of the power turbine independent from rotation of the compressor turbine;
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 connected to the chassis and positioned to pump fracturing fluid into a wellhead, the hydraulic fracturing pump connected to the output shaft such that the output shaft drives the hydraulic fracturing pump at the third rotational speed; and
a fracturing unit controller configured to:
generate one or more idle signals to cause the starter assembly to cause the compressor and the compressor turbine to rotate at a target idle speed while the power turbine remains at zero rotational speed, and 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 target signals indicative of one or more of a target pressure or a target flow rate associated with a fracturing fluid pumped into the wellhead, or one or more fluid flow signals indicative of one or more of an actual pressure or an actual flow rate associated with the fracturing fluid pumped into the wellhead.