A control-oriented modeling approach for two-phase flow plate heat exchanger

In this paper, a simple yet accurate model is proposed for real-time control and optimization of two-phase flow plate heat exchanger (PHE). The model is derived with selected controllable or measurable I/O parameters and heat mass transfer equations by mechanism analysis. The linear and nonlinear least-squares methods are adopted to identify unknown or empirical parameters to reduce the error of evaluation and prediction in applications. The modeling approach takes advantages of both mechanism and empirical model, which has the effectiveness that the unreachable parameters are eliminated while the computation is reduced with wide operating range. Validation was carried out in a substation in a district heating system, and the testing results showed that the proposed model can predict the performance of the PHE with a maximum error less than ±8% that satisfied the requirements of real-time control and optimization in applications.