Paper Conference

Proceedings of ASim Conference 2016: 3rd Asia conference of IBPSA-China, Japan, Korea


Optimal operation of multiple district heating and cooling systems through mutual interchange of heat

Y. Kawasaki, H. Kitora, Y. Akashi, J. Lim

Abstract: The purpose of this study is to optimize the operation of Multiple District Heating and Cooling (DHC) systems utilizing the thermal energy of river water as a heat source. The system we studied has two plants between which heat can be transferred through pipes. We developed a simulation model that allowed us to investigate details of the system's behavior such as the flow rate and pressure of several points in pipes, the opening rate of valves, and the frequency of inverter pumps. With this simulation, we conducted a case study of heat interchange control over one month during summer. Our results show that the COP of this system is improved by 2.8% with one control, but is reduced with some other controls. Having analyzed the heat transferring efficiency of pumps and the quantity of heat treated by each heat source machine, we conclude that ratio of treated heat to the total heat of the secondary heat source machines of both plants has a great influence on the system COP. Our results also show that increasing the amount of interchanged heat improves the heat transferring efficiency of the secondary pump system in both plants, while the efficiency of the secondary pump system has little influence on the system COP and, according to the condition of the secondary heat source machines, improving this efficiency does not improve system performance.
Keywords: Heat source system simulation, Initial commissioning, Energy-saving effect, Multiple DHC systems, Area-wide energy usage