| In the 1960s, the high-pressure FRP pipe was first developed in the United States. It soon took the place of the steel tube to be applied in the technological pipe line of petroleum collection and transportation, which achieved great economic and social benefits. The high pressure FRP pipe was introduced to China in the early years of three oil extraction to solve the steel tube corrosion problem caused by polymer. In order to break the international monopolization and fill in the blank of this field in China, designing the product line of high pressure FRP pipe with independent intellectual property right is becoming an urgent task for our FRP pipe industry.At present, three independent pieces of equipment are used to carry through winding, curing and extraction of FRP pipe. The external heating curing technique is used to cure the pipe, which increases the cost of equipment and production. In addition, the process of curing in the oven has many disadvantages like the low heat conduction efficiency and poor curing quality. The advanced internal heating curing technique adopts the method of winding the metal mandrel with the fiber and resin layers which can be heated inside. The heat energy in mandrel cavity can transfer to winding fiber layers directly through the metal pipe. By this way the curing efficiency and quality are improved greatly. In this paper the high pressure FRP pipe manufacturing system which adopts internal heating curing technique is designed, and the theoretical analysis and systemic study of the key technologies of winding and curing of FRP pipe are also conducted.Based on the traditional production technology of high pressure FRP pipes, the technology of heating the mandrel by steam is introduced into the curing process of FRP pipe, and the first high pressure FRP pipe production system in our country which only one machine tool is used to perform three processes of winding, curing and extraction is designed. This system integrates the traditional winding and extraction machines into one machine tool, and the hollow mandrel in which saturated steam, cooling water and compressed air can circulate is used to accomplish the winding, curing, cooling and sweeping.In order to study the internal course and analysis its mechanism of FRP pipe curing process, the cocurrencing and interrelating four courses during cure process are analyzed. They are chemical principle, the resin motion principle, the void action principle and the stress principle. Four mathematical models of curing processes of FRP pipe from four aspects are built. The thermal chemical model describes the relations of temperature and curing rate. The fiber motion model describes the tension variation, motion state and position of fiber in the process. The stress model describes the distribution of the stress and the strain in the pipe. The air hole movement model describes the generation, variation and movement of air hole inside the pipes. These models provide theoretic bases of scientifically design and optimize winding and curing process of FRP pipe.The selection and design of curing process curves is important factor that affect the quality of FRP pipe. The curing process of epoxy FRP pipe involves the heat conduction, thermosetting chemical reaction and the interaction between them, which is a complex coupling process. A finite element method is employed to study the distribution and change principle of temperature and curing degree during the cure process of FRP pipe. The lumped-mass approach is adopted to improve calculation precision, and the adaptive time step control to improve calculation efficiency. Based on the finite element software ANSYS and APDL the numerical simulation program of FRP pipe is developed. Curing process numerical simulation and analysis of high pressure FRP pipe is conducted, which is an effective way of designing the curing curve of FRP pipe.The control mode of electronic-gearing is proposed to realize winding synchronous motion control, which simplify the two axis servo control of traditional numerical control winding machine into one axis servo tracking control. Based on DSP and CPLD, the position synchronous motion controller which can perform none-uniform speed ratio control is developed. The control strategy of parameters self-tuning fuzzy PID is adopted to realize synchronous motion control. Simulation based on MATLAB shows that the fuzzy-PID controller can improve the robustness, the dynamic and static performance of the control system compared with ordinary PID controller. The internal heating curing high pressure FRP pipe product line developed in this paper has been applied in Daqing Hanwei Changyuan FRP Pipe Inc. and proves to be successful. The performance comparison test of pipelines manufactured by two different processes shows that the performance of the pipes manufactured by internal heating curing process is better. The elastic limit is 8.12% higher and the bursting pressure is 8.5% higher than the pipes manufactured by the external heating curing process. It proves that the internal heating curing process has achieved speediness and high efficiency in industrialized manufacturing of epoxy FRP pipe. It ends the history that we can't manufacture high pressure FRP pipe that agree with American API standard by ourselves.Finally, all the work in this paper is summarized and some further investigation contents are also proposed.
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