Research On High Pressure Pulse Test System

In hydraulic systems, there can be very large pressure impacts. The possible causes could be the opening and closing of hydraulic valves, startup of hydraulic pumps and also the variation of loads, there are very large pulse impacts. Generally, the intensity of pressure impacts is many times the normal working pressure. This kind of pulse impact will bring obvious adverse impact on the life of hydraulic components. It may cause rupture of pipelines, failure of operating components and etc. Due to this, pulse test is specified as a important test subject for some important hydraulic components in both the national and international hydraulic standards. In China, the development and application of high-pressure hydraulic pulse test system is rarely reported till now. In this paper, our focus is on the design of a pulse test system for hydraulic components; a hydraulic pulse test system is developed, and a control scheme for the system is also introduced. The thesis is organized as follows:1) Design of hydraulic system for high pressure pulse testBased on a thorough review and analysis of several kinds of schemes for pulse test, we propose a full scheme for high-precision, high pressure pulse test platform. We introduce a cylinder with variable cross-section to increase the pressure. High pressure is obtained with two steps of pressure lifting. The platform incorporates the modules of oil source, cooling circuit, and etc. It can produce stable pulse pressure of more than 100MPa.2) Control scheme for pulse pressure systemAfter a thorough analysis of the hydraulic system, a closed-loop control strategy is proposed; it regulates both the pressure at the pump outlet (low pressure) and also the pressure at the outlet of cylinder (high pressure).For the low pressure control system, a PID control strategy is used, while a discrete fuzzy PID strategy is proposed for the high pressure control.3) Experimental verification and analysis of the test resultsA pulse test system is finally fulfilled based on the proposed scheme. Some experiments are carried out to verify the feasibility and performance of the pulse test schemes. Results of experiments show that the hydraulic system and its control system are reliable and flexible. It can regulate the pressure of test pulses with high precision. Our scheme is proven to be able to serve the purpose of high pressure pulse tests.