Paper Conference

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


Study on Energy Performance of Various Air Handling System using CHP, Thermally-driven Absorption Chiller and Desiccant Air Handling Unit for an Office Building

Makiko Ukai, Hiroaki Tanaka, Hideki Tanaka, Masaya Okumiya

Abstract: Temperature and humidity independent control of air handling unit (THI-AHU) treats sensible and latent heat separately. One of the representative system for latent heat process in THI-AHU is desiccant air handling unit (DAHU). The combination of DAHU and sensible heat air handling unit (SAHU) does not require low chilled water temperature used for coupled temperature and humidity air handling unit (THC-AHU) in which moisture is removed by condensation dehumidification. However, heat is necessary to regenerate the adsorbent which contains moisture. Combined heat and power (CHP) is an option to provide hot water to a regenerating coil in DAHU. In addition, heat from CHP can be supplied to absorption chillers of gas fired double effect with hot water single effect (ABS-GH). This study investigated whole system energy performance and compared the system with gas fired double effect absorption chiller (ABS-G) and THC-AHU to the following two systems. One is the system with CHP, ABS-GH, ABS-G and THC-AHU in which heat from CHP is supplied to ABS-GH, and chilled water from absorption chillers is supplied to THC-AHU. The other is the system with CHP, ABS-GH, ABS-G, DAHU and SAHU in which heat from CHP is supplied to ABS-GH and DAHU, and chilled water is supplied to DAHU and SAHU. Static simulation is conducted during cooling season for middle size office building. Coefficient of performance for overall system (SCOP) based on primary energy consumption is applied for evaluation. When evaluating systems using CHP, heat from CHP is considered as a main product or a byproduct. In former case, SCOP of the systems with CHP is lower than that of the system without CHP. In latter case, SCOP of the system with CHP is higher than that of the system without CHP. The system with DAHU and SAHU achieves higher SCOP than the system with THC-AHU.
Keywords: System simulation, CHP, Absorption chiller, Desiccant air handling unit