Vashchyshak I. The improvement of noncontact methods of underground heat networks condition inspection

Dissertation is devoted to the problem of technical state inspection of underground trench less heat networks with urethane foam insulated pipes. The classification of main types of defects of underground heat networks with urethane foam insulated pipes is performed. It is theoretically examined the pipeline wall ground current dependence on diagnostic indicators changes that caused be the defects. The mathematical model of excited acoustic vibrations propagation from pipeline to the ground surface is developed. It is obtained ground surface acoustic pressure dependence on level of pipeline's acoustic excitation that considers acoustic properties of environments on the way of acoustic wave propagation. Heat network's thermal losses dependencies on thermal properties of insulation coating of pipeline and cover materials is examined. The unit for experimental research of double line underground heat network with urethane foam insulated pipelines with different defects is developed and produced. It is developed an identification method of defect types of underground heat network using three informative parameters (current in pipeline walls, acoustic pressure and temperature of near-surface soil over heat network). The information and measuring system for defects location detection in trenchless underground heat networks is developed. It is drafted the normative document on inspection technique of technical condition of underground heat networks with urethane foam insulated pipelines.