A theoretical and experimental study of transient characteristics of the heat exchange in a thermal control system

Abstract

Introduction. The “Heater-Blower-Room” thermal control system represents three different interconnected subsystems. It is necessary to study the transient characteristics of the heat exchange process, that is underway in the subsystems, including informative impulse responses, to stabilize the system operation. It is a non-parametric problem, and its solution requires identification algorithms. Materials and methods. Mathematical models of the subsystems represent the Volterra integral equation of the first kind with an undetermined difference kernel, or an impulse response. An impulse response evaluation is a solution to this equation in respect of registered noisy input and output values. The problem is to evaluate unknown impulse responses for the subsystems where the output of one subsystem is the input of another one. This problem is ill-posed, and features of identification-focused experiments do not allow to apply computational methods of classical regularization algorithms. The co-authors propose two specific non-parametric identification algorithms where impulse responses are evaluated using stable first derivatives by means of smoothing cubic splines through the optimal smoothing parameter selection on the basis of the statistical optimality criterion. Results. The co-authors solve inverse problems of impulse response identification and direct problems of heat flux reaction prediction. The research results demonstrate a high level of convergence between the evaluated data and observation findings. Both experimental and theoretical results represent the findings of the research performed by the co-authors. Conclusions. The results have proven the efficiency of the algorithms proposed for the identification of solutions to the problems of complex technical systems.