Constant power regulation system for duplex axial plunger pump and applications thereof

A constant power regulation system for a duplex axial plunger pump comprises a main valve body (001), an outer spring regulation screw (703), an inner spring regulation screw (701), an outer spring regulation nut (704), and an inner spring regulation nut (702). The main valve body (001) comprises an outer spring (706), an inner spring (708), a compensation rod (801), a compensation spool (802), and a compensation piston (805). The main valve body further comprises an inner spring converter (707), an outer spring converter (709), and a spring seat (710). The inner spring (708) is located between the inner spring converter (707) and the spring seat (710). The inner spring converter (707) runs through the outer spring (706) and the outer spring converter (709). One end of the outer spring (706) is in contact with the outer spring regulation screw (703), and the other end is in contact with the outer spring converter (709). The outer spring converter (709) is in contact with the inner spring converter (707) in a cooperative manner, and a gap is formed between the inner spring converter (707) and the inner spring regulation screw (701) and between the inner spring converter (707) and the spring seat (710). The inner spring converter and the outer spring converter enable the two springs to show four spring stiffness features in the compression process, and the fitting degree of a feature curve of the four shown comprehensive stiffness coefficients and a theoretical constant power hyperbolic curve is higher in the constant power regulation process. The mechanism can greatly increase the energy utilization rate of the plunger pump when the plunger pump works within the pressure load range of 15 MPa to 25 MPa; the overload state in which the plunger pump and a prime mover work is effectively avoided, thereby prolonging the service life of hardware.