Optimal Design of DHC Pipe Metwork of Seawater-source Heat Pump in Dalian's Xinghai Bay Commercial District

摘要

The district heating and cooling (DHC) system of a seawater-source heat pump is large system engineering.The pipe diameter of the DHC pipeline is large because the small temperature difference and very long running time.The traditional design methods only satisfy the needs of the technology but dissatisfy the needs of the economy,which not only waste a mass of money but also bring problems to the circulation,the maintenance and the management.So we build a least-annualized-cost global optimal mathematic model that comprises all the constrict conditions.A heuristic method GA (genetic algorithms) is used to obtain the optimal combination of discrete diameters.The hardy cross method is used to simulate the hydraulic conditions and the punish function is introduced to eliminated some restrictions.This optimal method is used to the design of the DHC pipe network of Xinghai Bay Commercial District which is a real engineering.The design optimization can avoid the matter of the hydraulic unbalance of the system,enhance the running efficiency and greatly reduce the annualized-cost comparing with the traditional design method.