Simulation Based Optimization of Dynamic Power Contro for Small Capacity Chillers
Abstract
The control strategy is essential for successful implementation of solar thermal cooling plants. One possible solution is a dynamic power control of the chiller capacity - especially if part load conditions have to be considered. When part load is included in results and should be obtained by simulations, the model of the chiller has to be able to give realistic results for mass flow and temperature variations of the external circuits. Such a model was introduced for an ammonia/water chiller and was used to set up a holistic simulation model in TRNSYS. The system configuration is based on real cases, which show good performance during operation. First simple control approaches indicate promising results. Compared to simple ON/OFF- control strategy 40% primary energy can be saved by using the dynamic power control. This control strategy includes the variation of mass flow rates of generator and recooling circuits and also the cooling tower fans with a simple linear modulation. Further results using different strategies will be presented.
Keywords
Solar cooling, Control strategy, Primary energy efficiency