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Energy Conversion and Management
Volume 155, 1 January 2018, Pages 253–261
Received 13 September 2017, Revised 22 October 2017, Accepted 23 October 2017, Available online 3 November 2017
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An enhancing mass transfer method based on the basic adsorption cycle is proposed.
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A new enhancing desorption solar adsorption refrigerator is designed and built.
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The comparison tests under different weather conditions are conducted.
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The circulating mass of refrigerant and COP of the new system are greatly improved.
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The desorption period of the new system is shortened.
The paper proposes a novel solar adsorption refrigeration system employing an active enhancing mass transfer method based on the typical basic cycle. In essence, the new method is to drop the internal pressure of the system in the desorption process. The working principle of the hypothesis and the cycle description are explained in detail and analyzed by laboratory experiments. The novel solar adsorption refrigeration system prototype with activated carbon-methanol as working pair was designed and built. Some different comparative tests under different weather conditions were conducted to prove the hypothesis and evaluate the performance of the novel adsorption refrigeration system. The experimental results show that the system employing an active enhancing mass transfer method will increase the mass of desorbed refrigerant by about 20% if compared with a natural desorption refrigeration system. It was also proved that the novel method is very effective for low adsorbent temperature operation, which may help to obtain a COPsolarincrease of at least 16.4%. And about one and half hours can be saved by enhancing desorption refrigeration system to get the same desorbed refrigerant with the natural desorption refrigeration system. The results of experiments show that the novel system has improvements in the coefficient of performance, the mass of desorption and desorption rate, and the characters of the solar adsorption refrigeration system can be a benefit to further application.
Volume 158, December 2017, Pages 147-160
YongfengXuXunMaReda Hassanien EmamHassanienXiLuoGuoliangLiMingLi
https://doi.org/10.1016/j.solener.2017.09.002Get rights and content
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Energy conversion and transmission characteristics of SIRACS driven by HDPES was analyzed.
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The system average energy utilization efficiency was 7.65%.
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0.92 kW SIRACS driven by HDPES could produce ice 52.56 kg serving user for 4 h at night.
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The best thickness of ice frozen on the evaporator was between 30 mm and 35 mm to the tube fin evaporator.
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The recommended super-cooled temperature for the ice storage air condition was in −2 °C to −5 °C.
The static ice refrigeration air conditioning system (SIRACS) driven by household distributed photovoltaic energy system (HDPES) was proposed and the energy conversion as well as the transmission performance were investigated by combining the theoretical calculation with experimental test. Results revealed that the system could be operated stably and continuously during three typical weather conditions (sunny, cloudy and light rainy) with an average photoelectric conversion efficiency of 11.76% and an average ice production of 52.56 kg. This system could continuously and stably serve user for 4 h during night. The models were verified to be reasonable and the simulated results were reliable. Meanwhile, the system average energy efficiency η was 7.65%. The performance analysis results showed that the ice making efficiency of the refrigerator was 50.19%, which was mainly responsible for the low energy efficiency. Therefore, to improve the refrigeration performance some optimization strategies were recommended and proposed in this paper.
Volume 139, 15 November 2017, Pages 571-579
GuangliangTianWudiZhangMinghuaDongBinYangRuiZhuFangYinXinglingZhaoYongxiaWangWeiXiaoQiangWangXiaolongCui
https://doi.org/10.1016/j.energy.2017.08.003Get rights and content
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Dominant OTUs were identified to construct a metabolic pathway of biogas production.
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Abundance of dominant bacteria increased when the biogas fermentation peak appeared.
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The dominant bacteria were involved in hydrolysis of cellulose and semi-cellulose.
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The metabolic pathway of acetogenesis almost disappeared between days 24 and 72.
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Key bacteria and archaea from hydrolysis to methanogenesis comprised 13–15 species.
Using high-throughput sequencing technology based on 16S rRNA genes and the determination of abiotic factors, the metabolic pathways and microbial community dynamics were analyzed in a batch biogas fermentation process with pig manure as the feedstock at 15 °C. The results showed the followings. 1) The decomposition rate of cellulose and semi-cellulose were close to maximal level at day 40.2) At the phylum level, the most dominant bacteria and archaea were Firmicutes and Euryarchaeota respectively. 3) Most dominant species maintained predominant positions even though the microbial community structure changed throughout the fermentation; in particular, the abundance of dominant bacteria increased when the biogas fermentation peak appeared. 4) The four most dominant bacterial species were involved in hydrolysis of cellulose and semi-cellulose. 5) The metabolic pathway and microbial composition in hydrolysis and acidogenesis are very similar, but those in acetogenesis and methanogenesis are different to some extent. The acetogenesis pathway almost disappeared between days 24 and 72.6) Even though the overall microbial communities consisted of >400 species, the key bacteria and archaea for hydrolysis, acidogenesis, acetogenesis, and methanogenesis comprised 13–15 species, and most of these species had high similarity (≥97%) to culturable strains.
Batch biogas fermentation
Cellulose
Abiotic factors
Bacterial community
Metabolic pathway
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