The results presented here correspond to the operation period from June 4th, 2007 to December 1st, 2007. From these 180 days the system was in operation during 108 day. The days without operation were either weekends or days without monitoring data due to a lightning stroke into the data acquisition system. Within these 108 days […]
4.1 Results Experiments have been conducted on the desiccant wheel with the parameters (e. g. outside temperature, outside humidity ratio, regeneration temperature and regeneration humidity ratio) varying in the range defined in the section 2. The complete DOE of 4 parameters operating between 2 levels needs 24=16 experiments. When a combination of the studied parameters […]
Performance of the chiller In order to evaluate the performance of the chiller a comparison of experimentally measured cooling capacities and COPs with expected values from calculations is shown in Fig. 2. The experimental values were selected according to the following criteria: 1. a continuous operation during the whole hour as well as in the […]
A detailed full dynamic simulation model of the installed system which considers the electricity consumption of all installed components (fans, pumps, etc.) has been developed by zafh. net in the simulation environment INSEL . The simulation model is used to analyse the effect of different storage charge and discharge options. A very small time step […]
In Fig. 3 and Fig. 4 a histogram of the measured COP and cooling power is shown. COPs between 0.48 to 0.62 were obtained. The measured power shows a much larger dispersion: cooling powers between 3.1 and 5.9kW have been obtained.
In table 1 the selected building applications and energy efficiency standards are described.  Coefficient of Performance (COP) = cooling or heating output (kW) divided by electrical input. The only electrical input is 4 small circulation pumps and internal controls. COP in conventional compressor-based chillers and packaged air conditioning units is usually stated as cooling […]
The control system start the chiller only if a driving temperature above 72°C is available, and turns the machine off when it falls below 68°C (Fig. 5). The measured heat rejection temperatures were very favourable for the chiller: in 95% of the hours an inlet temperature to the machine between 18°C and 20°C was registered. […]
From the 282 operation hours in the cooling mode about 35.8% (101 hours) no solar operation was possible. On 148 hours (52%) a complete solar operation covering the whole hour was possible, on the remaining 33 hours the solar system could only provide a part of the driving heat. From an energetic point of view, […]