Investigation of Reversible Heat Transfer in a One-Pipe Heating System

Introduction. With the standard mode, heat transfer in one-pipe heating systems is significantly inferior to heat transfer in two-pipe systems. The development of pulse technologies for heating systems made it possible to create a reversible heat transfer in which heat transfer in heating devices is improved through the heat transfer agent pulsation, but the heat transfer coefficient depends largely on technological solutions for creating this reversing mode. In this connection, developing original technological scheme for reversible heat transfer based on the diaphragm pump and substantiating optimal frequency range of its operation is relevant and practically important for improving one-pipe heating systems.Aim of the Study. The study is aimed at increasing the efficiency of one-pipe heating systems through creating reversible heat transfer agent supply using a diaphragm pump.Materials and Methods. There were used the methods of circuits, physical experiment and mathematical statistics to establish experimental dependences of the temperature difference for the heating and heated circuits of reversible heat transfer through one pipe on the frequency of pulsations of the heat transfer agent flow at different inlet temperatures in dynamics. The physical experiment was carried out at two heat transfer agent temperatures(50 and 60°C).Results. With the use of the laboratory setup for reversible heat transfer through one pipe, there have been found the optimal frequency for two heat transfer agent temperatures, providing an increase in the temperature difference in the circuits and the heat transfer coefficient. There have been found dependences of temperature difference for heating (external) and heated (internal) circuits of heat transfer and heat transfer coefficient for the heat exchanger on the pump diaphragm stroking rate.Discussion and Conclusion. As a result of the physical experiment, it has been found that the heat energy transfer through one pipe is possible in a wide frequency range (from 0.15 to 0.4 Hz), while the greatest heat transfer is recorded at a frequency of 0.3–0.4 Hz. The technology of heat transfer through one pipe can be successfully used for heating common areas in apartment buildings, dormitories, industrial and agricultural facilities, and individual residential buildings.