Optimizing the Low Temperature Cooling Energy Supply: Experimental Performance of an Absorption Chiller, a Compression Refrigeration Machine and Direct Cooling - a Comparison

Abstract

A strategy to optimize the low temperature cooling energy supply of a newly build office building is discussed against the background of a changing energy system. It is focused on, what production way - Direct Cooling, the Compression Refrigeration Machine or the Absorption Chiller provided with heat from Combined Heat and Power Plants - has the lowest primary energy consumption at what load level. For low levels this is direct cooling. If demand exceeds the capacity of direct cooling, the absorption chiller is the option to choose. However, in future the compression refrigeration machine is more efficient at providing high load levels than the Absorption Chiller. The operation analysis shows that flow rates are often held constant and the re-cooling temperatures are often above the ambient temperature. By the integration of automatic flow rate control and lowering the re-cooling temperature of the chillers, electricity consumption of pumps can be reduced and energy efficiency enhanced.