农业工程学报
農業工程學報
농업공정학보
2015年
10期
235-240
,共6页
侯静%杨桔材%郑宏飞%常泽辉%于苗苗%马元波
侯靜%楊桔材%鄭宏飛%常澤輝%于苗苗%馬元波
후정%양길재%정굉비%상택휘%우묘묘%마원파
太阳能%粒子%热能%苦咸水淡化%功能化
太暘能%粒子%熱能%苦鹹水淡化%功能化
태양능%입자%열능%고함수담화%공능화
solar energy%particles%thermal energy%brackish water desalination%functioned
针对太阳能苦咸水淡化系统中太阳能集热系统在高温段时效率低,而苦咸水淡化系统在低温段时效率低的结构性不匹配问题,提出了聚光蒸发式太阳能苦咸水淡化系统。为了提高苦咸水对入射太阳光的吸收作用,对太阳能集热系统中的苦咸水进行功能化处理,并对功能化苦咸水的透射率进行了光学性能分析,在实际天气条件下,对功能化苦咸水的热能利用效率进行了试验研究。结果表明,功能化苦咸水的透射率随粒子丰度增加而减小,随粒径减小而降低;粒子丰度由6.25增加为50.0 mg/L时,含有粒径为0.72 mm粒子的功能化水体的热能利用效率增加了41.3%;功能化苦咸水热利用效率计算结果与光学性能测试结果变化趋势一致。该研究为提高太阳能苦咸水淡化系统热利用效率提供了参考。
針對太暘能苦鹹水淡化繫統中太暘能集熱繫統在高溫段時效率低,而苦鹹水淡化繫統在低溫段時效率低的結構性不匹配問題,提齣瞭聚光蒸髮式太暘能苦鹹水淡化繫統。為瞭提高苦鹹水對入射太暘光的吸收作用,對太暘能集熱繫統中的苦鹹水進行功能化處理,併對功能化苦鹹水的透射率進行瞭光學性能分析,在實際天氣條件下,對功能化苦鹹水的熱能利用效率進行瞭試驗研究。結果錶明,功能化苦鹹水的透射率隨粒子豐度增加而減小,隨粒徑減小而降低;粒子豐度由6.25增加為50.0 mg/L時,含有粒徑為0.72 mm粒子的功能化水體的熱能利用效率增加瞭41.3%;功能化苦鹹水熱利用效率計算結果與光學性能測試結果變化趨勢一緻。該研究為提高太暘能苦鹹水淡化繫統熱利用效率提供瞭參攷。
침대태양능고함수담화계통중태양능집열계통재고온단시효솔저,이고함수담화계통재저온단시효솔저적결구성불필배문제,제출료취광증발식태양능고함수담화계통。위료제고고함수대입사태양광적흡수작용,대태양능집열계통중적고함수진행공능화처리,병대공능화고함수적투사솔진행료광학성능분석,재실제천기조건하,대공능화고함수적열능이용효솔진행료시험연구。결과표명,공능화고함수적투사솔수입자봉도증가이감소,수립경감소이강저;입자봉도유6.25증가위50.0 mg/L시,함유립경위0.72 mm입자적공능화수체적열능이용효솔증가료41.3%;공능화고함수열이용효솔계산결과여광학성능측시결과변화추세일치。해연구위제고태양능고함수담화계통열이용효솔제공료삼고。
Fresh water demands are increasing day by day because of industrialization, motorization and increased life standards of mankind. Fresh water reserves available naturally are not capable of meeting the fresh water demands because of their less availability. Desalination is not only necessary to overcome the issue of fresh water shortage in the future, but also important for the oil-gas-coal industry which generates substantial amount of waste water during the production of oil, natural gas and coal. Compared to conventional water treatment technology, solar brackish water desalination has advantages of cleanness and sustainability. However, high cost and small scale have become the biggest obstacles for solar brackish water desalination technology, which is caused by the high-cost solar collector, the structural mismatch of the optimum working ranges between the solar collector system and the brackish water desalination system, and the large heat transfer resistance between them. To solve this problem, this paper has proposed a strong light-concentrating direct evaporationtype solar brackish water desalination system. It utilizes the concentrating solar energy which is directly shined into the functioned brackish water to produce steam for repeated usage. It should be noted that solar collector is introduced to collect much more solar energy and produce steam efficiently to improve the performance of solar desalination units. The light-induced evaporation type solardesalination units show small heat transfer resistance, heat capacity small and small cavity evaporation, which can largely reduce the cost and be beneficial for the economic performance of the solar desalination system. Generally, the functioned brackish water is in the boiling state during the system working. The transmissivity of the functioned brackish water in the boiling state was measured in optical darkroom. At the same time, thermal energy utilization efficiency of functioned brackish water was tested in dish type concentrating system under actual weather condition. The objective of the work was to determine the influence of abundance and size of particles on the optical and thermal performance of the system. The variations of transmissivity for brackish water through different optical paths were recorded under the same conditions. The dish type concentrating solar desalination device was then constructed according to the optical analysis results. The characteristics of temperature and performance ratio(PR) of the water were obtained through outdoor experiment. A dimensionless parameter of “efficiency rate” was used in this paper to evaluate the extinction performance of the functioned brackish water (30-60℃).The results indicated that functioned water could be obtained through adding black particles in brackish water. In addition, the transmissivity of the functioned brackish water decreased with the increasing of abundance, and with the decreasing of particle size. With the smallest particle size of 0.72 mm used in the experiment, the transparency rate of the brackish water reached the lowest value, and the transmissivities through 2 different optical paths decreased by 75.83% and 77.08%, respectively. When the particle abundance increased from 6.25 to 50.00 mg/L, the increase rate of thermal energy utilization efficiency of the functioned brackish water could reach 41.3%. Finally, it was found that the trend of thermal energy utilization efficiency was consistent with the transmissivity.