Abstract: A gas turbine overspeed protection method includes: a power utilization load of a generator is acquired, and a rotating speed value of a gas turbine is acquired; whether the power utilization load suddenly decreases or disappears is judged, and if so, an eddy current retarder is controlled by a controller to simulate the power utilization load to provide a braking torque for the generator; or, whether the rotating speed value exceeds a set speed range is judged, and if so, the gas turbine is controlled by the controller to reduce fuel supply, and a discharge valve of a gas compressor is opened to discharge a high-pressure gas to reduce the power output and the rotating speed of the gas turbine.

Abstract: This disclosure generally relates to power generation methods and systems based on gas turbine engines, and particularly to mobile and adaptive power generation systems and methods based on gas turbine engine for supplying mechanical and/or electrical power for fracturing operations at an oil wellsite. Various systems, platforms, components, devices, and methods are provided for flexibly and adaptively configure one of more gas turbines, hydraulic pumps, and electric generators to support both fracturing and electric demands at a well site. The disclosed implementations enable and facilitate a mobile, adaptive, and reconfigurable power system to provide both mechanical and electric power for hydraulic fracturing operation.

Abstract: The present invention discloses a special modified expandable polystyrene copolymer particle for a lost foam, which respectively comprises the following parts by weight: 90 to 100 parts of styrene; 3 to 8 parts of methyl methacrylate; 100 to 140 parts of deionized water; 0.2 to 0.5 part of benzoyl peroxide; 0.2 to 0.5 part of dicumyl peroxide: 0.1 to 0.5 part of tert-butyl peroxybenzoate: 0.001 to 0.01 part of anionic surfactant; 1 to 2 parts of suspension concentrate; 5.0 to 10.0 parts of foaming agent; 0.1 to 0.4 part of nucleator; 0.2 to 2 parts of organic bromine; 0.01 to 0.1 part of molecular weight regulator having the effect of increasing molecular weight, and 0.3 to 0.5 part of surface coating agent.