MODEL FOR THE DEVELOPMENT OF A LOW COST THERMAL MASS FLOW METER
This paper presents the mathematical model for the development of a water mass flow meter. Its operation principle is based on a relation between a constant input power (heat flow) provided to the system and the increase of temperature in the test section. A numerical model of the thermal and fluid dynamic behavior of the thermal mass flow meter is carried out; the governing equations (continuity, momentum and energy) inside the tube together with the energy equation in the tube wall and insulation are solved iteratively in a segregated manner. The parametric study developed with the numerical model includes the tube diameter, tube length, and the power supply to the system, with the numerical results obtained and taking into account some restrictions on the system, the final design of the system has been obtained and constructed. A test procedure was carried out to show the technical feasibility of this system and an error of mass flow rate of ± 0.55 % was obtained. In relation to the cost, the errors of experimental measurement are acceptable if they are compared with some of the more common available commercial systems with much higher cost.
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