Evaluation of Ways to Improve the Energy Efficiency of Sites of First Rise Supply Water Systems with Storage Tank by Laboratory Modeling

The paper considers the main ways to reduce operating costs in the sites of the first rise of water supply systems with a storage tank. Theoretical and laboratory confirmations of the maximum energy efficiency of the frequency control method by the performance of pumping units are made. The attention is focused on the problem of freezing water in the pipeline with a change in a volume flow. Possible methods for determining optimal parameters of the water supply system for protection from freezing are described. The requirements for the physical model of the pipeline system are substantiated, taking into account the dynamic change in the volumetric flow rate and the water temperature in the line. The description of the laboratory stand allowing simulating various operating modes of the first rise section is given. The hydraulic characteristics of the water supply system are experimentally determined when the frequency of the supply voltage of the pumping unit changes. Experimentally, the level of the electric power consumption is defined by the pump unit at the maintenance of the required volume flow by the method of frequency regulation. The change in the water temperature in the pipeline at various flow rates and ambient temperatures is experimentally determined. On the basis of the data obtained, the reliability of theoretical methods for calculating the thermal parameters of the pipeline is verified and their error is estimated.