Energy performance enhancement of Hong Kong International Airport through chilled water system integration and control optimization

Poor energy performances of building systems in practice are often observed, especially under off-design conditions (i.e. at low part load ratios). In order to overcome such problem, most of existing methods are developed merely considering single system or building. Unlike them, a method integrating the chilled water systems in the neighboring buildings is proposed to enhance the overall energy performance of the Hong Kong International Airport. The system integration allows the excessive cooling from one building to be delivered to the other. In addition, one 1000 RT chiller is relocated from Terminal 2 to Terminal 1. After the system integration and chiller relocation, three different sized chillers can be selected to satisfy the overall cooling load with higher part load ratios. Meanwhile, the control optimizations of chillers and seawater pumps also contribute to the system energy performance improvement. With limited investment cost and easy implementation, the proposed method and the control optimization significantly enhance the airport system energy performance. The direct field data comparison demonstrated the average chiller plant COP value is improved by 5.93%. The simulated case studies indicated an annual energy saving about 4.70 M kWh is achievable.