Due to the diversity and complexity of the causes of the heating failure of the hydraulic system, it is extremely difficult to trace the source of the on-site diagnosis. Taking the heating failure of the hydraulic system during the jacking process of a certain tower crane as an example, the virtual fault information obtained from the fault tree analysis is injected into the thermal fluid simulation model of the tower crane jacking hydraulic system, and the influence characteristics of the virtual fault on the system pressure and oil temperature are obtained. The fault diagnosis is realized by comparing with the temperature rise curve of the fault hydraulic system on the test bench. The research results show that the fault characteristics caused by the lowering of the set pressure of the relief valve are highly consistent with the test results, so it is determined that the overflow caused by the lowering of the set pressure of the relief valve is the main cause of the system heating fault, and the fault can be solved after on-site adjustment. The virtual simulation method of hydraulic system based on fault injection can effectively reproduce the real fault characteristics of hydraulic system and provide necessary reference for fast and effective fault diagnosis of complex hydraulic system.

The hydraulic support system in fully mechanized face is huge and complex, working environment is special, so emulsified pollution is an outstanding problem, which influences the performance and efficiency of the hydraulic support system, high pressure back flushing filter station is an important emulsion cleaning equipment in the system. The pollution control model is constructed, pollution equilibrium equations are derived for high pressure emulsion back flushing filter station in ore. Flow division coefficient and back flushing efficiency are introduced for back flushing time simulation research, that indicate the parameters influence relation for back flushing time, at last accuracy and feasibility of the pollution control simulation model is discussed by the comparison analysis of experimental and simulation results, the higher the back flushing efficiency is, the higher the flow division coefficient is, the shorter the back flushing time is, and the higher the cost is, the back flushing model based on pollution control is effective that provides a theoretical criterion for the optimal design of high pressure back flushing filter station.

The design of the hydraulic manifold block is time-consuming, laborious, and prone to make mistakes due to the vertical intersection and dense complexity of its internal oil passage network. The mathematical optimization model of this problem is given based on the comprehensive analysis of the structural characteristics and design rules of the internal orifices of the hydraulic manifold block. Using the integrated circuit layout algorithm for reference, an optimization design method of a multi-wire mesh channel network based on routing sequence optimization is proposed and verified by an example. The research results show that the optimization of the connection order between multiple wire networks at both ends and the routing order between multiple wire networks in a single-wire network can not only achieve the optimal design of the connectivity of the single-wire network but also ensure the optimal connectivity result of the entire hole network. At the same time, as the bottom core algorithm of the integrated block layout optimization design, it can provide a powerful technical guarantee for improving the integrated block design level, quality, and automation.