Investigation and Evaluation on District Energy System at Kitakyushu Science and Research Park-Field Study on Running Situation during 2002

A district energy system in Kitakyushu Science and Research Park (KSRP) has been introduced. In this paper, the system’s running situation was analyzed by using the recorded data in 2002. Generating electricity, heat recovery efficiency and recovery heat utilization efficiency for gas engine and fuel cell were calculated. On the basis of the above study, energy saving and CO 2 reduction were evaluated. The results can be summarized as follows: 1) The on-site generating electricity equipments provided 51.2% of the total electricity demand, including fuel cell with 34.5%, gas engine with 13.4% and PV system with 3.3%. In total heat energy demand, 70% of hot water load, 30.9% of cooling load and 14.3% of heating load were provided by recovering the heat energy from fuel cell and gas engine system. 2) Fuel cell was running 8572 hours with constant generating electricity efficiencies, about 30.8%. Gas engine only run 4281 hours with higher generating electricity efficiencies, about 24.5%. PV system achieved over 8% module conversion efficiencies in 83% of generating electricity time.3) Fuel cell had lower heat recovery efficiency, but this heat energy recovered almost was utilized by the heat exchanger or absorption chiller. Gas engine had higher heat recovery efficiency, but only 70% of them were utilized by heat recovery equipments. 4) Compared with the conventional energy supply system, the district energy system achieved 56% primary energy utilization efficiency, 10.9% saving energy ratio and 1.32% CO 2 reduction ratio.