Investigation of Transient Process of Heat Carrier Temperature of Water to Air Heat Exchanger

Abstract

Transient process of the outlet heat carrier temperature of water to air heat exchanger is investigated. This transient process, provoked by instantaneous change of inlet heat carrier temperature, is tripartite: the time delay, the initial jump of temperature and the temperature change from the initial jump to the steady state value. The mathematical expressions for calculation of the delay, the initial jump and the steady state temperature are presented. Mathematical model for investigation of the temperature change from the initial jump to the steady state is described. It was defined that this temperature change, at precise evaluation, is not the first order lag (exponential) process, but for many tasks of automatic control of heating devices can be considered as such. The block scheme of heat exchanger representation in ACS of heat carrier temperature is delivered. The empirical equation for calculation of exponential process time constant is proposed. Ill. 3, bibl. 11 (in English; abstracts in English and Lithuanian).

DOI: http://dx.doi.org/10.5755/j01.eee.118.2.1183