Use of an ultrasonic flowmeter has demonstrated its feasibility for the transmission of indicators to a computer network.Development of flow-metering systems meeting requirements for the reliability and required accuracy of determination of flow rates and volumes of water consumed is one of the complex and critical problems of power engineering.Virtually all domestic HPP are equipped with spiral turbine flowmeters operating on the principle of pressurehead measurement in the spiral case by the Winter-Kennedy method. According to the method in question, the flow rate is calculated from the formulawhere K is a constant coefficient, h is the pressure gradient between two points of the spiral case, and n is an exponent. This method is recommended by domestic and international standards [1,2]. It possesses, however, significant drawbacks to which the following are basically referred:-a large scatter of K and n values, even for the monotypic hydraulic-turbine units of multiple-set hydroelectric plants;-the inertia of the measurement system as the load on the set changes;-loss of airtightness of the pulse tubes connecting the nipples of the pressure tap with a secondary fitting;-restoration of the serviceability of pulse tubes is virtually impossible, since they are laid out in the concrete mass, and are inaccessible for repair; and, -in addition to low reliability, such a system generates a high error.At the present time, official spiral flow meters have lost serviceability at more than 90% of the water-power entities in the Russian Federation, and instrument metering of the flow in the turbines is essentially not done. This does not correspond to requirements for energy conservation and rational utilization of water-power equipment. In this connection, ultrasound systems for determination of flow rate, which are devoid of the drawbacks common to traditional spiral flowmeters, have come into widespread use in recent years.The Scientific-Research Institute of Power-Generating Structures (JSC NIIÉS) has acquired experience with the implementation of these systems on water-power projects over many years. An ultrasound system for the measurement of flow was first used in domestic practice at the Bratsk HPP in 1983 [3] for power-generating tests to obtain actual turbine efficiencies, and determine the expediency of impeller replacement. Thereafter, the ultrasound system for flow-rate determination has been used in power-generating tests of hydraulic sets at the Nurek, Baipaza, Vilyui HPP, and the Zagorsk State Regional Power Plant. Moreover, an automated system for efficiency determination of hydraulic turbines [4], which is intended for the following uses, has been employed:-in performing warranty tests to evaluate the quality of the fabrication and assembly of hydraulic machinery;-for calibration of official in-service flow rates; and, -as a subsystem of the automated control system for heat flow to diagnose the condition of the settings of hydraulic machinery, and ascertain causes of emergency situations.Tests of the aut...
