Research On Energy Saving Technology For Cutter Head Drive System Of Shield Tunneling Machine

Shield tunneling machine is a modern construction equipment dominating the tunneling field. Nowadays, the shield tunneling machine which is related with subjects of hydraulic, electrical and mechanical control, materials, computers and other technology has the advantages of high automation, labor saving, fast speed of construction and small impact to the buildings on the ground, etc., and is widely applied in construction projects such as subway, rail, highway, city planning, urban pipeline tunnel and other construction projects. Hydraulic drive technology is widely used in many areas with its stable transmission, convenient speed regulating, great ratio of power to volume and other excellent characteristics. But the hydraulic system is inefficient, especially in shield tunneling machine that energy consumption is huge. So it has important practical significance to research energy saving of the hydraulic system in shield tunneling machine. Considering the high cost, complicated structure and the security on field operations, it is necessary to establish the simulation test rig to study the core technology of shield tunneling machine.This paper takes the simulation cutter system of shield tunneling machine as research object which simulate the actual conditions encountered on the working process. A test rig was built including the design of principle, component selection and the designs of hardware and software of the monitoring system. Simulation and experiment were done based on the test rig, energy analysis on the frequency control and variable displacement speed of the cutter system at different load conditions will be researched and the law of force and energy transfer in the shield machine will be revealed for the development of the next generation of shield tunneling machine. The main contents of this paper are as follows:In chapter 1, the work principle and the composition of shield tunneling machine were firstly introduced, then the present and future development state of the shield tunneling machine was described. Moreover the hydraulic drive system of cutter head in the shield tunneling machine was elaborated. Finally the significance and main research content of this subject were proposed in view of the development of energy saving on the shield and principle of the test rig.In chapter 2, a semi-physical simulation test rig was built according to the contents of this paper. The working principle of the hydraulic system was clarified and the key components of this rig were designed and selected. Then the software and hardware of electronic control system in this test rig were designed, and the data acquisition system of this test rig was programmed using the LabVIEW software.In chapter 3, the mathematical models of variable speed pump-motor speed regulating system and variable displacement pump-motor speed regulating system were established. According to composition of the test rig, the dynamic equation and the time-domain mathematical model of the system were obtained, and open loop transfer functions of the two systems were established.In chapter 4, the energy consumption and power characteristics in hydraulic drive system for cutter head in shield tunneling machine were analyzed based on the composition of energy transfer chains. The efficiency of motor and volumetric efficiency and mechanical efficiency of the pump were given. The impact of each part upon the whole system was analyzed in depth, the law of energy transfer in driving source of cutter head system, transfer chains and executing agency was revealed, and the principle of energy saving in cutter-head speed regulating system of shield tunneling machine was clarified which laid the theoretical foundation for the next simulation and experimental research.In chapter 5, comparisons of efficiency between the hydraulic systems with variable speed and variable displacement were carried out based on the semi-physical simulation test rig for cutter-head of shield tunneling machine. The load and system between this test rig and the actual shield were similar by analyzing the load characteristics of test rig system. Then the efficiency improvement of the variable speed hydraulic system applied in cutter-head drive was analyzed which indicated that the experimental results had practical significance.