Volume 18: Sustainable Energy Solutions for a Post-COVID Recovery towards a Better Future: Part I

Application of Nonlinear Programming Algorithms in Dynamic Hydraulic Optimization of District Heat Networks: A Case Study From a Chinese University Ruijie1 Ma, Junhong Yang, Xinyu Shi, Xuyang Cui, Mianshan Cui

Abstract

As one of the important energy systems, heating systems often suffer hydraulic imbalances and high energy consumptions in district heat networks. To further reduce the operational energy consumption of pumps and achieve hydraulic balance, the utilization of nonlinear programming algorithms for hydraulic optimization of district heat networks was proposed. With the actual heating system of a university as a use case, a dynamic hydraulic optimization model was established using the nonlinear programming algorithm to optimize the pump frequency, valve opening and thermal inlet flow rate. The actual data (from 2019 to 2020 and from 2020 to 2021) were selected for the simulation and comparison of the difference between the simulated energy consumption and the actual one by using four different dynamic regulation methods. The results reveal that with the dynamic regulation under day-by-day, day-night, time-by-time, and large temperature difference operation methods, the pump energy consumption could be reduced by 25.0%, 32.7%, 38.2%, and 61.1%, respectively compared with the actual operation. Therefore, the selection of large temperature difference dynamic regulation can further reduce the pump energy consumption of the system, and the work provides a certain reference for the dynamic hydraulic optimization regulation of heat network.

Keywords heating systems, nonlinear programming, hydraulic optimization, dynamic regulation