Energy-saving Simulation And Study On Rotation Hydraulic System Of Fire Truck Based On Secondary Regulation

With the enhancement of environmental awareness and the growth of energy crisis, high efficiency energy-saving products were more and more welcomed in market. Hydraulic power transmission, a common method of power transmission, had its unique advantages of power density and control performance, it was wildly applied to engineering and industrial products such as construction machinery and numerical control machining center. However, as a result of interference factors such as friction and leakage, hydraulic transmission system always worked at a low level of energy utilization, which restricted the development and application of this technique. Hence, Energy-saving technique had been a very significant issue of hydraulic transmission research.Secondary regulation system was a new-developing branch of hydraulic transmission. It had the advantages of energy recycle and high control accuracy, which led to a promising prospect of application and development. So far, foreign scholars had applied this technique to several industrial products on stage of product test, however domestically there were few studies on secondary regulation in engineering application. The study of this paper was based on a real project. It analyzed and designed a secondary regulation hydraulic system for rotary transmission section of a multi-functional fire rescue breaker, and studied energy recycle performance under different system parameters. To be specific, the main work of this paper could be concluded in aspects as follows:(1) A principal introduction of secondary regulation system was given, which included analysis and presentation on working performance of critical elements in secondary regulation system. Based on that, the mathematical model of the system, which included models of accumulator, servo valve, control cylinder and secondary element, was built.(2) Load of rotary mechanism of fire rescue breaker was calculated and analyzed, based on which it introduced the design principle of the system. In convenience of simulation study, a simplification of load was also presented.(3) A mathematical model of secondary regulation rotary speed control system was built and simplified. Based on the model, A PID controller was designed, and a series of simulation was run through MATLAB/Simulink, with the help of simulation, it discussed the influence that parameter fluctuation brought to the system. An F-PID controller based on fuzzy control principle was designed for a better performance, simulation results showed that F-PID controller performed better in control characteristics.(4) A theoretical analysis of energy recycle efficiency was studied. A further study of how system parameters influenced energy recycle efficiency was surveyed through simulation. Considered system parameters included brake time, rotary speed, equivalent rotary inertia and system pressure. The result of simulation showed energy recycle efficiency would increase under less brake time, smaller rotary speed, larger equivalent rotary inertia and lower system pressure.