Solar Cooling for Southern Climates, Double Effect Absorption Chillers with High Concentrating Collectors Versus Standard Single Effect Systems

Abstract

In the present paper solar thermal cooling systems applied to office buildings in hot southern climates are analysed. The solar cooling systems are considered to be applied to a planned innovative office building in Cairo, Egypt. Dynamic building simulations with TRNSYS where used to calculate the cooling load of the analysed building. Single effect absorption chillers with vacuum tube collectors are analysed as well as double and triple effect absorption chillers with high concentrating collectors as heat source such as parabolic trough or Fresnel collectors. The dynamic simulation environment INSEL is used for the analysis of the solar cooling systems. Apart from the thermal performance of the systems also the electricity consumption of all components like cooling tower, external pumps and absorption chiller are considered in the calculated. For the double and triple effect absorption chillers additional heating provided by an external or integrated gas burner is considered if the heating energy from the solar system is not sufficient to cover the cooling load of the building. For all analysed systems additional cooling delivered by a standard compression chiller is considered to cover the remaining part of the cooling load. The primary energy consumption required to cover the whole cooling load of the building and the resulting primary energy ratio are used to compare the overall performance of the analysed solar cooling systems.