Emerging Energy Efficient Thermally Driven HVAC Technology: Liquid Desiccant Enhanced Evaporative Air Conditioning

Solar energy can play a significant role in increasing the environmental sustainability of air-conditioning systems and a number of thermally-driven solar air-conditioning technologies are available. Among these technologies, liquid-desiccant systems have the potential to operate efficiently at lower regeneration temperatures, allowing for better use of flat plate collectors. In these systems, air to be conditioned is dehumidified through direct contact with a desiccant solution. This solution is then heated at the regenerator and water is evaporated into a scavenging air stream. This paper presents an analysis of the heat and mass transfer in a parallel-plate internally-heated liquid-desiccant regenerator. Using a finite-difference technique, a numerical analysis was performed to solve the species and energy equations. The influence of regenerator hot water parameters (temperature and mass flow), and solar collector efficiency on regeneration capacity and specific energy consumption was evaluated.

Download Full-text

Experimental evaluation of desiccant dehumidification and air-conditioning system for energy-efficient storage of dried fruits

Building Services Engineering Research and Technology ◽

10.1177/0143624419893660 ◽

2019 ◽

Vol 41 (4) ◽

pp. 454-465 ◽

Cited By ~ 3

Author(s):

Muhammad H Mahmood ◽

Muhammad Sultan ◽

Takahiko Miyazaki

Keyword(s):

Experimental Evaluation ◽

Energy Efficient ◽

Air Conditioning ◽

Evaporative Cooling ◽

Ambient Conditions ◽

Fruit Storage ◽

Dried Fruits ◽

Thermally Driven ◽

Dried Fruit ◽

Dried Foods

The ideal storage zones of dried fruits in comparison with dried foods and feeds are established on the psychrometric chart. The study investigates the combined effect of the desiccant dehumidification and Maisotsenko-Cycle evaporative cooling for the dried fruits storage. Two configurations of desiccant air-conditioning systems (S-I and S-II) are proposed, and their performance is evaluated under the ambient conditions of Fukuoka, Japan. It is established on the basis of parametric and thermodynamic analysis of both the system configurations (S-I and S-II) that S-II could yield better system performance. The psychrometric evaluation of S-II revealed that it can provide the optimal conditions for the storage of dried fruits at low regeneration temperature. However, modification in the proposed system configuration (S-II) is suggested for the storage of dried foods and feeds. Practical application: Conventional dehumidification and air-conditioning options are either expensive or inefficient for dried fruit storage buildings. The study provides a way forward of using thermally driven desiccant systems which are energy-efficient and environment-friendly. Worldwide, the building industries are actively involved in the development of such systems but their application for dried fruit storage buildings are not explored in detail. Therefore, the study provides thermodynamic details of dried fruits storage in relation with experimental evaluation of desiccant and evaporative cooling systems. Provision of such systems to the storage buildings will provide distinct control of humidity and temperature for optimal storage.

Download Full-text

Energy Efficient Liquid Desiccant Hybrid Air Conditioning System

International Journal of Modeling and Optimization ◽

10.7763/ijmo.2014.v4.375 ◽

2014 ◽

Vol 4 (3) ◽

pp. 211-215

Author(s):

Y. A. F. El-Samadony ◽

B. M. Gibbs

Keyword(s):

Energy Efficient ◽

Air Conditioning ◽

Liquid Desiccant ◽

Air Conditioning System

Download Full-text

Experimental Analysis on the Performance of Regeneration of Solar Liquid Desiccant System under Different Operation Condition

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.521.48 ◽

2014 ◽

Vol 521 ◽

pp. 48-51

Author(s):

Sun Jian

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Air Conditioning ◽

Liquid Desiccant ◽

Operation Condition ◽

Air Conditioning System ◽

Thermally Driven ◽

Diluted Solution ◽

Set Up

Liquid desiccant air-conditioning system is one kind of thermally driven open-cycle absorption air-conditioning systems which have been widely researched and applied because of its unique advantages in recent years.In this paper, an experimental equipment of liquid desiccant air-conditioning system was set up based on the mechanism of liquid desiccant dehumidification and regeneration. The dehumidifier and regenerator were all counter-flow towers and body of the tower were made of stainless steel to withstand the corrosive effect of the liquid desiccant. In experiments, mixture desiccant of calcium chloride and lithium chloride was applied.The performance of regeneration of the system was studied under different system operating condition. The effects of the inlet parameters on the efficiency of regeneration are discussed. The results show that the mass flow rate,humidity of the air,temperature and mass flow rate of the diluted solution can all affect the performance of regeneration of the system.

Download Full-text

Dehumidification and thermal regeneration characterization of binary deep eutectic solvents in liquid desiccant air conditioning systems

Journal of Building Engineering ◽

10.1016/j.jobe.2021.103056 ◽

2021 ◽

pp. 103056

Author(s):

Temidayo L. Oladosu ◽

Hussain H. Al-Kayiem ◽

Syed I.U. Gilani ◽

Aklilu T. Baheta

Keyword(s):

Air Conditioning ◽

Deep Eutectic Solvents ◽

Liquid Desiccant ◽

Thermal Regeneration ◽

Air Conditioning Systems

Download Full-text

Assessment Methodology for Efficiency, CO2-Emissions and Primary Energy Consumption for Refrigeration Technologies in the Industry

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.882.215 ◽

2018 ◽

Vol 882 ◽

pp. 215-220

Author(s):

Matthias Koppmann ◽

Raphael Lechner ◽

Tom Goßner ◽

Markus Brautsch

Keyword(s):

Energy Consumption ◽

Energy Efficient ◽

Air Conditioning ◽

Primary Energy ◽

Primary Energy Consumption ◽

Assessment Methodology ◽

Alternative Technologies ◽

Overall Efficiency ◽

Chp System ◽

The Individual

Process cooling and air conditioning are becoming increasingly important in the industry. Refrigeration is still mostly accomplished with compression chillers, although alternative technologies are available on the market that can be more efficient for specific applications. Within the scope of the project “EffiCool” a technology toolbox is currently being developed, which is intended to assist industrials users in selecting energy efficient and eco-friendly cooling solutions. In order to assess different refrigeration options a consistent methodology was developed. The refrigeration technologies are assessed regarding their efficiency, CO2-emissions and primary energy consumption. For CCHP systems an exergetic allocation method was implemented. Two scenarios with A) a compression chiller and B) an absorption chiller coupled to a natural gas CHP system were calculated exemplarily, showing a greater overall efficiency for the CCHP system, although the individual COP of the chiller is considerably lower.

Download Full-text