Overall modeling and power optimization of heating systems by standard thermal resistance-based thermo-hydraulic model

Abstract

Modeling and optimizing the heating system simultaneously considering the power and working flow constraints, to find a suitable operation strategy is important for reducing energy consumption. This paper mainly focuses on the optimization of the flow rate and pump operation frequency of the heating system. The standard thermal resistance method is used to establish the heat current model of each component, which can accurately reflect the heat transfer characteristics of the system. On this basis, heat transfer constraints are established at the system level, and the hydraulic constraints of the heating system are also considered. Under the heat and flow networkability constraints, the optimal operation strategy of each pipeline valve opening and frequency conversion pump frequency under different indoor air temperatures is obtained by using genetic algorithm with the total power consumption of the system as the optimization objective. The optimization results show that both the frequency and the total pump power of the secondary network pump decrease with the increase of indoor temperature. The frequency of the secondary pump after optimization at 288 K is 68.27 Hz and the total power consumption is 198.36 W, which reduces the total power consumption by about 25.3 % compared with the pre-optimization. Compared with other previous studies, the consideration of the hydraulic conditions of the heating system was added. In conclusion, the optimization model and method are effective in improving and evaluating the energy consumption of building heating systems.