Rotary desiccant air conditioning system, which combines the technologies of desiccant dehumidification and evaporative cooling, is advantageous in being free from CFCs, using low grade thermal energy and controlling humidity and temperature separately. Compared with conventional vapor compression air conditioning system, it preserves the merits of environment-friendly, energy saving, healthy, comfortable, etc. Ongoing research and development works suggest that new desiccant materials and novel system configurations have significant potential for improving the performance and reliability and reducing the cost and size of rotary desiccant dehumidification and air conditioning system, thereby increasing its market competitiveness and breaking out the current fairly small niche market. For the purpose of providing an overview of recent efforts on these issues and showing how rotary desiccant air conditioning systems can be designed and coupled to available thermal energy, this paper presents and analyzes the status of rotary desiccant dehumidification and air conditioning in the following three aspects: the development of advanced desiccant materials, the optimization of system configuration and the utilization of solar energy and other low grade heat sources, such as solar energy, district heating, waste heat and bioenergy. Some key problems to further push forward the research and development of this technology are also summarized.

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Technical development of rotary desiccant dehumidification and air conditioning: A review

This paper gives a comprehensive overview about the recent advances related with the application of the nanotechnology in various kinds of the solar collectors. Papers reviewed including theoretical, numerical and experimental up to date works related with the nanotechnology applications in the flat plate, direct absorption, parabolic trough, wavy, heat pipe and another kinds of the solar collectors. A lot of literature are reviewed and summarized carefully in a useful tables ( Table 1 , Table 2 , Table 3 , Table 4 , Table 5 , Table 6 , Table 7 ) to give a panoramic overview about the role of the nanotechnology in improving the various types of the solar collectors. It was found that the use of the nanofluid in the solar collector field can play a crucial role in increasing the efficiency of these devises. We think that this paper can be considered as an important link between the nanotechnology and all available kinds of the solar collectors. From the other side, further researches are required to study the effect of nanotechnology to enhance the solar collector industry over the next several coming years.

Applications of nanotechnology to improve the performance of solar collectors – Recent advances and overview

A numerical and experimental study on a heat pipe PV/T system

Recently, solid desiccant air conditioning system has been proposed as an alternative to the conventional vapor compression refrigeration air conditioning systems for efficient control over humidity of conditioned air especially in hot and humid areas. The solid desiccant cooling can be more favorable over the traditional vapor compression refrigeration air conditioners, because it assures more accessible, economical and cleaner air conditioning. It is still more important when it is powered by free energy sources like solar energy and waste heat with temperatures of between 60°C and 80°C. In addition, it can significantly reduce the operating cost as well as save energy. In the present paper, principle of solid desiccant cooling system is recalled and its technological applications and advancements are discussed. Through a rigorous literature review, different configurations of desiccant cooling cycles, conventional and hybrid desiccant cooling cycles, different types of mathematical models of rotary desiccant dehumidifier, performance evaluation of desiccant cooling system, technological improvement and the advantage it can offer in terms of energy and cost savings are highlighted. This paper also gives a detailed account of the general features and performance of the solid desiccant cooling system when it is powered by solar energy or industrial waste heat for regenerating the desiccant. This review is useful for making opportunities to further research of solid desiccant cooling system and its feasibility which is becoming common in the coming days.

Solid desiccant air conditioning – A state of the art review

Performance study and parametric analysis of a novel heat pipe PV/T system

Potential of solar heat pipe vacuum collectors in the desiccant cooling process: Modelling and experimental results

Using solar thermal energy is an interesting option for heat driven air conditioning e.g. desiccant cooling, but it is very important to know with which efficiency this renewable energy is used. In this paper a solar installation of direct flow vacuum tube collectors dedicated for desiccant cooling is investigated. First a model of the mentioned collectors is presented and implemented into the simulation environment SPARK then it is validated experimentally. After, simulations of autonomous operations are run and the global efficiency is calculated. Finally the effect of increasing the regeneration temperature on the efficiency is studied.

Global efficiency of direct flow vacuum tube collectors in autonomous solar desiccant cooling: simulation and experimental results

Using solar thermal energy is an interesting option for heat-driven air conditioning, e.g. desiccant cooling. In this article, the autonomous operations of a solar desiccant cooling plant powered by direct-flow vacuum-tube collectors are investigated. A model of the solar installation and the desiccant air handling unit is presented and implemented in the SPARK simulation environment and then it is validated experimentally. The overall cooling efficiency of the system is evaluated using simulation for humid and moderately humid climates and the effect of increasing the regeneration temperature on the cooling capacity, the overall cooling efficiency is studied and finally the overall efficiency of the collectors is calculated for the studied cases.

Overall cooling efficiency of a solar desiccant plant powered by direct-flow vacuum-tube collectors: simulation and experimental results

A control strategy to prevent the impact of outside and load conditions on the hygro-thermal performance of a desiccant cooling system

Subtask C1 coordinator: Michael Krause, Kassel University Report edited by: Robert Ghirlando, University of Malta Contributions from: Erich Podesser, AEE-INTEC, Austria Robert Ghirlando, University of Malta Tomas Núñez, Fraunhofer, ISE, Germany Mustafa Jaradat, Kassel University Michael Krause, Fraunhofer, IBP, Germany Roland Heinzen, Kassel University, Germany Lucio Mesquita, Enerworks Inc. Canada Paul Bourdoukan, LOCIE-INES/CNRS, France Etienne Wurtz, LOCIE-INES/CNRS, France Klaus Ellehauge, Ellehauge and Kildermoos, Denmark Constanze Bongs, Fraunhofer ISE, Germany Clemens Pollerberg, Fraunhofer UMSICHT, Germany Pietro Finocchiaro, DREAM, University of Palermo, Italy Marcelo Izquierdo Millán, CSIC, Spain José Daniel Marcos del Cano, UNED, Spain

Paul Bourdoukan

Papers

Potential of solar heat pipe vacuum collectors in the desiccant cooling process: Modelling and experimental results

Global efficiency of direct flow vacuum tube collectors in autonomous solar desiccant cooling: simulation and experimental results

Overall cooling efficiency of a solar desiccant plant powered by direct-flow vacuum-tube collectors: simulation and experimental results

A control strategy to prevent the impact of outside and load conditions on the hygro-thermal performance of a desiccant cooling system

Task 38 Solar Air-Conditioning and Refr iger ation C1: State of the art - Survey on new solar cooling developments