scholarly journals An Overview of Recent Studies on the Development of Desiccant Air-conditioning Systems

Author(s):  
Hossein Fatahian ◽  
Hesamoddin Salarian ◽  
Esmaeel Fatahian

In the past decades, desiccant cooling systems have received much attention. These systems are considered as an alternative way to decrease energy consumption and greenhouse gas emission in humid and hot locations. To address the importance of desiccant air-conditioning systems, the present research aims to provide an overview of recent studies on the development of desiccant air conditioning system. Another objective is to consider the numerical and theoretical analysis of desiccant systems. Moreover, for the first time, a summary of recent researches regarding the use of Computational Fluid Dynamics (CFD) technique for numerical modeling of desiccant cooling systems has been especially reviewed in detail. Finally, in the present review, the principle of regeneration of liquid desiccant using solar energy have also been considered briefly.

2005 ◽  
Vol 16 (4) ◽  
pp. 59-66 ◽  
Author(s):  
V Mittal ◽  
KS Kasana ◽  
NS Thakur

An air-conditioning system utilizing solar energy would generally be more efficient, cost wise, if it was used to provide both heating and cooling requirements in the building it serves. Various solar powered heating systems have been tested extensively, but solar powered air conditioning systems have received very little attention. Solar powered absorption cooling systems can serve both heating and cooling requirements in the building it serves. Many researchers have studied the solar absorption air conditioning system in order to make it economically and technically viable. But still, much more research in this area is needed. This paper will help many researchers working in this area and provide them with fundamental knowledge on absorption systems, and a detailed review on the past efforts in the field of solar absorption cooling systems with the absorption pair of lithium-bromide and water. This knowledge will help them to start the parametric study in order to investigate the influence of key parameters on the overall system performance.


2011 ◽  
Vol 33 (4) ◽  
pp. 423-435 ◽  
Author(s):  
Fu Xiao ◽  
XiaoFeng Niu

Liquid desiccant is an energy-saving, environmentally friendly and healthy means of air dehumidification. A liquid desiccant-based all-air air conditioning system is studied by simulation. Two different modes of air mixing between the return air and the fresh air are compared, that is mixing before and mixing after the liquid desiccant dehumidifier, respectively. System performance and total energy consumption of the two modes under different operation conditions are obtained. The results show that mixing air after dehumidification consumes less energy than mixing air before dehumidification. Coefficient of performance (COP) of the all-air system with air mixing after dehumidification is higher. The differences of COP and energy consumption between the two air mixing modes increase when the outdoor air temperature and relative humidity increase. Practical application: Liquid desiccant based all-air system is quite suitable for museums, libraries and computer centres where water is not allowed to enter the space for property safety and strict thermal-hygrometric control is necessary. The results of this paper provide guidelines on the selection of air mixing modes in liquid desiccant-based all-air systems, considering energy consumption and system COP.


2007 ◽  
Vol 4 (1) ◽  
pp. 48 ◽  
Author(s):  
A. M. Abu-Zour ◽  
S. B. Riffat

Most conventional cooling/refrigeration systems are driven by fossil fuel combustion, and therefore give rise to emission of environmentally damaging pollutants. In addition, many cooling systems employ refrigerants, which are also harmful to the environment in terms of their Global Warming Potential (GWP) and Ozone Depletion Potential (ODP). Development of a passive or hybrid solar-driven air-conditioning system is therefore of interest as exploitation of such systems would reduce the demand for grid electricity particularly at times of peak load. This paper presents a review of various cooling cycles and summarises work carried out on solar-driven air-conditioning systems. 


2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.


2013 ◽  
Vol 291-294 ◽  
pp. 1880-1883
Author(s):  
Li Ping Xiang

A numerical model to improve the air-conditioning system of vehicle cabin taking into the cabin air moisture and its transport by the airflow within the enclosure cabin is described. An efficient computational fluid dynamics(CFD) technique is using the “realisable” model. The temperature and humidity fields in the passenger cabin are investigated individually under having or no body moisture. The temperature in the vehicle cabin taking into account human moisture is lower than no taking into account moisture 0.5 °C. The human dispersing moisture effect significantly on the humidity, which lead to the humidity is elevating and the humidity in vehicle cabin is corresponded hygienic standard.


Energy ◽  
2016 ◽  
Vol 109 ◽  
pp. 180-189 ◽  
Author(s):  
Li Yinglin ◽  
Zhang Xiaosong ◽  
Tan Laizai ◽  
Zhang Zhongbin ◽  
Wu Wei ◽  
...  

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