Computer-Aided System for Designing the Thermal Energy Metering Devices

The paper presents the developed computer-aided design (CAD) system of thermal energy metering devices, which includes flowmeters with standard primary devices. Theoretical bases for CAD developing are considered, in particular, algorithms for determining the thermal energy amount that are developed by the authors, complete mathematical model of differential pressure flowmeter, realized by taking into account the limitations of standards DSTU GOST 8.586.1-5:2009, IAPWS methods for determining water and steam properties, a method for calculating the isentropic exponent of steam, a method for estimating the uncertainty of measurement result of thermal energy amount, developed by the authors, as well as new approaches to the computer-aided design of thermal energy metering systems proposed by the authors. The main characteristics of subsystem for entering and validating the input data are presented. The CAD dialog box for entering the characteristics of measuring instruments of pressure, differential pressure, temperature, which are the components of thermal energy metering system, as well as the dialog box for entering the characteristics of measuring pipe. The basics of the developed technique for estimating the uncertainty of thermal energy amount that is implemented in CAD are presented. The structure of protocol of designing a thermal energy metering system is considered.