Performances of the Hybrid Active Desiccant Wheel System with Type III Desiccant

2010 ◽  
Vol 34-35 ◽  
pp. 167-171
Author(s):  
Yuan Zhi Zuo ◽  
Sheng Li Wen ◽  
Xi Ya Li

A new type of hybrid desiccant air conditioning system combining an active desiccant wheel with a conventional front-positioned cooling coil is presented, in which Type Ⅲ desiccant is used in the active desiccant wheel. Then a preliminary experiment is carried out in order to investigate the feasibility of the hybrid desiccant system serving as a dedicated outdoor air system (DOAS). The result shows: under the two typical outdoor air conditions in the area of South China, the desiccant system which only needs to adopt a regeneration temperature of 45°C without lowering the cooling coil temperature can satisfy the requirements of the dehumidification; when operating in the climate with a high humidity of 90% and a high-temperature of no more than 36.5°C, the desiccant system only driven at a regeneration temperature of 60°C can also provide enough dehumidifying capacity; but compared with the active desiccant wheel using Type Ⅰor Type Ⅱ desiccant, this system can not reach a lower dew point. Therefore, this system can operate effectively at a moderate regeneration temperature, suitable for the high quality and comfortable air conditioning.

2019 ◽  
Vol 111 ◽  
pp. 02021
Author(s):  
Djallel Abada ◽  
Chadi Maalouf ◽  
Tala MOUSSA ◽  
Amel Ferial Boudjabi ◽  
Guillaume Polidori ◽  
...  

Refreshing air remains a crucial problem in warm climates where electricity consumption for air conditioning has become excessive and irrational for several years, notably in Algeria. Research in this field is increasingly oriented towards new techniques that can reduce costs and environmental impacts. Among these techniques, the evaporative dew point cooling technology is the most promising as it can cool outdoor air to temperatures below its wet bulb temperature. The aim of this work is to model and design a dew point cooler for french and algerian climates. This model is used to study the effect of the cooler parameters such as its length, water temperature and working air ratio on its cooling effectiveness and supply temperature.


2014 ◽  
Vol 628 ◽  
pp. 332-337
Author(s):  
Xiao Xia Xia ◽  
Nai Jun Zhou ◽  
Zhi Qi Wang

The energy consumption of several central air conditioning systems in summer was researched by the method of exergy analysis. Combined with actual example,the exergy loss of all the equipments and the exergy efficiency of three systems were calculated. The results show that the exergy efficiency of three systems is very low. Relatively speaking, the exergy efficiency of primary return air conditioning system with supplying air in dew point is highest. The equipment of highest exergy loss is air-conditioned room, while the exergy loss of surface air cooler is smallest. Based on this, several improvement measures were proposed to reduce exergy loss and improve exergy efficiency.


2019 ◽  
Vol 27 (04) ◽  
pp. 1950034 ◽  
Author(s):  
Nguyen Minh Phu

When water chillers are arranged in series-series counterflow (SSCF), the compressor lift of each chiller is decreased in comparison with that of water chillers in parallel. This means that the compressor power of SSCF chillers is lower than that of parallel chillers. In this paper, models of the main components in an air conditioning system were developed and verified to predict the behaviors of the whole system with respect to SSCF chillers. The results showed that performance was maximized with three SSCF chillers when the system was operated with normal set points. The performance was further improved to 26% and decreased with the number of SSCF chillers when the system was operated with optimal set points. The SSCF chiller system also demonstrated higher exergy efficiency regardless of the number of SSCF chillers. The irreversibility of components in SSCF chillers was rather low. However, the irreversibility of the cooling tower and cooling coil was slightly higher and lower, respectively, than those in the parallel chiller system.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 522
Author(s):  
Su Liu ◽  
Jae-Weon Jeong

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.


2009 ◽  
Vol 2009 (0) ◽  
pp. 65-66
Author(s):  
Makoto Koganei ◽  
Shinsuke Kato ◽  
Ryozo Ooka ◽  
Wanghee Cho ◽  
Yaw-Shyan Tsay ◽  
...  

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