Theoretical and applied aspects of using a thermal pump effect in gas pipeline systems

Abstract

Based on the classical method for calculating parameters of gas pipelines using electrohydraulic analogy, a mathematical model of the object, the process of gas transmission in an industrial pipeline, has been developed. The study subject was the change of gas temperature after its passing through a throttling device which brings about thermal pump effect in the receiving strand of the gas pipeline. It was proposed to use gas-dynamic thermal pumps to minimize the risk of plug and hydrate formation in the gas pipeline of Kharkivtransgaz Co. It was shown that the change of the ground body temperature by ±10 °C in the 20 km long gas transmission section of the multi-strand pipeline system causes a change of gas pressure by 5−15 %. A theoretical-empirical formula for determining the Joule-Thomson coefficient was derived which allows one to estimate the thermal pump effect on the energy and thermobaric parameters of nonstationary gas transmission processes. It was determined that the integral coefficient of performance (COP) for the network system of multi-strand pipelines including gas-dynamic thermal pumps varies within the range of 1.00‒1.09 depending on the ambient temperature (0−20 °C). The principles of constructing the topology of the diagram of the gas pipeline with bridges and branches which, due to the use of the thermal pump effect, ensures a minimal risk of plugging and hydration consist in activation and regulation of the energy-transforming and heat exchange processes in the sections of the network system. This is achieved by introduction of additional throttling devices in front of the bridges and branches of the pipeline and by checking for proximity and bordering with critical temperatures of plug and hydrate formation.На основе классического метода расчета параметров газопроводных сетей с использованием электрогидравлической аналогии разработана математическая модель объекта – процесса транспортировки газа в промышленном трубопроводе. Предмет исследования – изменение температуры после прохождения газом междуничочного дросселирующего устройства, которое вызывает эффект теплового насоса в принимающей нитке газопровода. Предложено использовать трассовые-газодинамические тепловые насосы для минимизации риска корко- и гидратообразования в УМГ "Харкивстрансгаз".