Abstract
In this paper, we investigate implications of running a cooling system of two silicagel/water adsorption chillers powered by a district heating network. The devices are connected in series, i.e., the heating water output from the primary chiller is directed to the secondary one. In consequence, the secondary device must deal with an even lower driving temperature and with temperature fluctuations caused by the primary device. We have evaluated three factors that influence the operation of those coupled devices: synchronization of their operating cycles, selection of their cycle time allocations (CTAs), and changing the heating water mass flow rate. Numerical analyses indicate that the performance of the secondary chiller drops significantly if the coupled devices that use the same CTA run asynchronously. The decrease is largest if the shift between the operating cycles is x=0.375 and x=0.875. We found that it is possible to reduce the negative influence of the asynchronous operation by implementing different CTA in each chiller. The best performance is achieved if the primary chiller uses an adsorption time to desorption time ratio f=1.0 and the secondary chiller uses f = 0.6–0.7.
Highlights
Tri-generation systems or combined cooling, heating and power systems (CCHPs), have become more popular during the past decades. These integrated systems offer higher thermal efficiency compared to traditional power generation systems, are more cost effective and have lower environmental impact
A typical CCHP system consists of a power generation unit working together with heating and cooling components
In this paper, we numerically analyze the performance of two two-bed silica gel/water adsorption chillers that are powered by low-temperature heat from a district heating network
Summary
Tri-generation systems or combined cooling, heating and power systems (CCHPs), have become more popular during the past decades. The heating water mass flow rate remains the same, but as a consequence, the secondary chiller will always run below its nominal performance capability. In both configurations, both chillers are cooled and produce chilled water independently. In this paper, we numerically analyze the performance of two two-bed silica gel/water adsorption chillers that are powered by low-temperature heat from a district heating network. This study is focused on three factors that influence the performances of two adsorption chillers connected in series: synchronization of their operating cycles, consequence of using different cycle time allocations, and sensitivity to the change of mass flow rates of the media. The outcome is a recommendation on how to set CTAs independently for each chiller in a way that will prevent a performance drop in the secondary device
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
