2013 年 30 巻 3 号 p. 191-202
In the field of the central air-conditioning systems, variable water volume control (VWV) has been brought to attention to reduce the electricity consumed by water pumps, as well as to improve component performances. In the VWV of chilled water and cooling water passed through absorption chillers, what is important is the compatibility of energy saving and reliable operation while also controlling water flow rate and heat input. We dynamically simulated an absorption chiller to investigate this system. This chiller both calculates and transmits the controlled flow rate of chilled water and cooling water. Heat input control is simulated for both continuous and three position control. As the simulation result with assumption of cooling load profile, the estimated electricity reduction ratio is approximately 70% for the chilled water pump and 60% for the cooling water pump compared to the case of constant water volume system. On the other hand, cooling efficiency, defined as accumulated cooling calorie per accumulated heat input, is 99.5% of the constant water volume system, for continuous control. To improve the reliability of the operation, output temperature of chilled water is kept at 7±2°C in both continuous and three position controls.
