Investigation Of Solar Absorption Cooling System Based On Cooling Ceiling

Solar absorption cooling system provides air conditioning to buildings in summer using clean solar energy. Generally speaking, compared with traditional electric air-conditioning system, the efficiency of solar absorption cooling system is lower, so it has great significance to improve the efficiency of solar absorption cooling system. According many ways of improving the efficiency of solar absorption cooling system, a more effective way is increasing outlet chilled water temperature. However, the rise of outlet chilled water temperature also stands for the lack of dehumidification capacity. Therefore, it is necessary to study e the application mode of solar absorption cooling system. This Article focused on solar absorption cooling system based on cooling ceiling. Experimental and theoretical investigations were carried out. The main research work included:1. This Article studied solar absorption cooling system based on cooling ceiling. The system consisted of vacuum tube collectors, one adsorption chiller, hot water tank, cooling ceiling, fan coil and independent dehumidification unit. The system provided air-condition to the 50 m2 test room. It could achieve fan coil operation mode and cooling ceiling operation mode by switching the pipelines. Under cooling ceiling operation mode, the independent dehumidification unit as a supplementary was open to achieve temperature and humidity independent control, satisfied the demanding temperature and humidity.2. Set up theoretical model including U-type vacuum tube, hot storage tank, absorption chiller, cooling load and indoor thermal environment. The accuracy of the theoretical model as the foundation for theoretical analysis was verified by experiments.3. Under typical summer weather condition, the operating characteristic of solar absorption cooling system based on cooling ceiling was studied.(1) During stable operation, it was found that the average cooling output and COP separately reached 4.75 kW and 0.36,the outlet chilled water temperature was 16.2oC. (2) The energy conservation was improved through grading process of humidity. (3) Average indoor temperature and humidity respectively was 24.5 oC and 50%.In order to comparing the operating characteristic of solar absorption cooling system under fan coil operation mode and cooling ceiling operation mode, the performance of absorption chiller and indoor thermal comfort was compared. (4) It was suggested that compared with an coil operation mode, under cooling ceiling operation mode, both cooling capacity and COP of absorption chiller were improved. (5) Under the same weather condition, indoor thermal comfort level was C using fan coil, while it was A using cooling ceiling. The unite operation of cooling ceiling and independent dehumidification unit could improve the performance of absorption chiller and the indoor thermal comfort level.4. The main purpose of solar absorption air-condition system is to meet cooling demand of building, It involved in how to allocate the system to accommodate variations of cooling load. So it is necessary to study characteristic of cooling load by the building and cooling capacity by the solar absorption cooling system. Based on theoretical model, the analysis was developed from two aspects, the environmental parameters influencing performance of absorption chiller and the structural parameters influencing matching rate of cooling load and cooling capacity. The research was focus on main factors that affected cooling output of solar absorption chiller. It proposed three load matching index of cooling load and cooling capacity, providing theoretical basis of the optimized configuration.