文档介绍：Combined Air-conditioning and Tap Water Heating Plant, Using CO 2 as Refrigerant for Indonesian Climate Condition By Willy Adriansyah Thesis submitted in partial fulfillment of the requirements for the degree of Doktor Ingeni?r (.) Norwegian University of Science and Technology Faculty of Mechanical Engineering Department of Refrigeration and Air-conditioning April 2001 ii iii Abstract bined air-conditioning and water heating system using carbon dioxide as refrigerant has been investigated theoretically and experimentally. puter program simulates bined system has been developed and verified with experimental data. Effects of the following parameters to the system performance were examined: ratio of hot water load to rejected heat from air-conditioning system (load ratio), evaporation temperature, cooling medium temperature, inlet water temperature, hot water temperature, discharge pressure, and presence of internal heat exchanger. Main results were coefficient of performance and cooling capacity. It was concluded that there is an optimum pressure where the system reaches the highest coefficient of performance. Variation of coefficient of performance of the combined system with discharge pressures is similar to that of the air- conditioning system without heat recovery. Load ratio affects the performance of the air-conditioning side. Coefficient of performance of the air-conditioning side (cooling-COP) increased with increasing load ratio. Optimum discharge pressure was affected by load ratio. Improvement of cooling-COP depends on both cooling medium and inlet water temperatures. The cooling-COP was lower at higher cooling medium temperature and higher inlet water temperature. When inlet water temperature is higher than cooling medium temperature, the cooling-COP will be pared to the air- conditioning system without heat recovery. The system performance decreased as hot water temperature increased. The decrease is due to a need