Control And Process Optimizing Of Internal-Heating-Cured High Pressure FRP Pipes

The high-pressure FRP pipe is short for Fiberglass-Reinforced Plastics pipe, providing many advantages, such as corrosion-resistance, light weight, high strength, small resistance for liquids, long service life, which makes it has a wide range of application in the fields of petrochemical industry, aerospace, architecture, etc. Due to the resources of petroleum are uneven distribution and the consumption of oil is unbalance, resulting in long distance transportation, which will have more requirements for the production of FRP pipes.In the middle of 1960s, we began to produce FRP pipe independently, the"external heating curing"technique was used to cure the FRP pipes, which delivered heat to the high-pressure FRP pipe by means of radiation, conduction and convection. The new"internal heating curing"technique used the way of heating the internal mandrel of FRP pipe to finish the process of curing.The principle of FRP pipe, curing process and internal structure of winding pipe are analyzed in this paper, designed internal heating curing control system which consist of oulu temperature as the core, Omron PLC as auxiliary, Siemens intelligent locator as actuators, temperature sensor and pressure sensor as detection device, Taida touch screen as human-computer interface display device. The control system can accomplish accurate temperature control of all phases of FRP pipe curing by PID intelligent control algorithm self-contained of oulu temperature.The degree of FRP pipe curing objectively reflects the variation of internal stress, and the curing temperature is an important factor for the process of curing, the control of the whole curing process can be accomplished by controlling the temperature of all phases. The fiber grating sensors can be used to detect the temperature variation of internal testing point clearly, and the curing control system can be used to control the temperature of all phases of the FRP pipe. Based on the finite element software ANSYS, 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 internal heating curing control system has been tested in Yangzhou Xinyang technology development limited liability company, the results shows that the error of temperature control of FRP pipe is±2℃. The product quality inspection shows that the control system can produce FRP pipes which are of high quality, high efficiency and low consumption in batch production.