西安建筑科技大学学报(自然科学版)

对平板型太阳能集热器表面积尘进行测试,分析了积尘对其系统性能的影响.研究表明,在同等外界条件下,以集热器表面积尘量11.58 g·m-2为例,系统得热量显著下降,集热效率下降了17.40%.通过试验测试,分析了松散和粘结两种积尘状态下不同积尘量对系统集热性能的影响.在具有相同积尘量的条件下,粘结状态积尘对集热性能的影响高于松散状态积尘.在积尘初期系统集热效率下降速度较快,而后逐渐变缓.该研究对太阳能集热器积尘进行定期清洁、提高换热效率具有参考意义.

Solar collectors are the key components in the solar collector system, in which thermal performance determines the efficiency of solar heating system. In order to investigate the effect of natural dust on the performance of flat-plate collector, the filed tests are performed on the solar collectors under the same circumstance with the dust and cleaning conditions of the glass cover surface. The results show that compared with the cleaned collector, a dust density of 11.58 g·m-2 corresponds to a 17.40% reduction in thermal collection performance. Furthermore, contrast test is conducted to illustrate the effect of different dust forms on collector performance. With loose dust solar collector, the collector with cohesive dust exerts bigger influence on thermal performance in solar heating system. It is found that the collector performance decreases fast at the beginning of the dust accumulation and then gradually slows down. This study can provide a reference in formulating cleaning strategies of collector and improving the heat transfer efficiency of solar heating system.

引言
1 试验装置及测试内容
2 理论分析
3 结果与讨论
4 结论

图1 平板太阳能热水系统<br/>Fig.1 Solar hot water system with flat-plate collector

图1 平板太阳能热水系统
Fig.1 Solar hot water system with flat-plate collector

图2 测试系统测点布置图<br/>Fig.2 Layout of measuring points in test system

图2 测试系统测点布置图
Fig.2 Layout of measuring points in test system

图3 积尘平板集热器盖板表面光线传播原理图<br/>Fig.3 Schematic of light propagation in flat-plate collector with dust accumulation

图3 积尘平板集热器盖板表面光线传播原理图
Fig.3 Schematic of light propagation in flat-plate collector with dust accumulation

图4 集热器盖板表面松散与粘结积尘形态对比图<br/>Fig.4 Comparison of loose and cohesive dust forms on the glass cover of flat-plate collector

图4 集热器盖板表面松散与粘结积尘形态对比图
Fig.4 Comparison of loose and cohesive dust forms on the glass cover of flat-plate collector

图5 集热器表面温度对比(第一次测试)<br/>Fig.5 Comparison of surface temperature of collector(The first test)

图5 集热器表面温度对比(第一次测试)
Fig.5 Comparison of surface temperature of collector(The first test)

图6 集热器表面温度对比(第二次测试)<br/>Fig.6 Comparison of surface temperature of collector(The second test)

图6 集热器表面温度对比(第二次测试)
Fig.6 Comparison of surface temperature of collector(The second test)

图7 储水箱内水温和温差变化<br/>Fig.7 Comparison of water temperature and temperature difference in the storage tank

图7 储水箱内水温和温差变化
Fig.7 Comparison of water temperature and temperature difference in the storage tank

图8 两组集热器循环工质进出口温度变化<br/>Fig.8 Comparison of import/export temperature of circulating fluid between two groups of collectors

图8 两组集热器循环工质进出口温度变化
Fig.8 Comparison of import/export temperature of circulating fluid between two groups of collectors

图9 两组集热器表面温度变化<br/>Fig.9 Comparison of surface temperature of collector between two groups of collectors

图9 两组集热器表面温度变化
Fig.9 Comparison of surface temperature of collector between two groups of collectors

图10 系统集热性能下降率变化趋势图<br/>Fig.10 Trend of the descent rate in collector performance

图10 系统集热性能下降率变化趋势图
Fig.10 Trend of the descent rate in collector performance

图11 松散状态积尘量与集热性能下降关系<br/>Fig.11 Relationship between the amount of loose dust and the decrease of collector performance

图11 松散状态积尘量与集热性能下降关系
Fig.11 Relationship between the amount of loose dust and the decrease of collector performance

图12 粘结状态积尘量与集热性能下降关系<br/>Fig.12 Relationship between the amount of cohesive dust and decrease of collector performance

图12 粘结状态积尘量与集热性能下降关系
Fig.12 Relationship between the amount of cohesive dust and decrease of collector performance

表1 松散状态不同工况试验结果<br/>Tab.1 Experimental results of loose dust under different operating conditions

表1 松散状态不同工况试验结果
Tab.1 Experimental results of loose dust under different operating conditions

表2 粘结状态不同工况试验结果<br/>Tab.2 Experimental results of bonded dust under different operating conditions

表2 粘结状态不同工况试验结果
Tab.2 Experimental results of bonded dust under different operating conditions

图13 两种积尘状态测试结果对比<br/>Fig.13 Comparison of test results between two dust forms

图13 两种积尘状态测试结果对比
Fig.13 Comparison of test results between two dust forms

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备注

引言

1 试验装置及测试内容

2 理论分析

3 结果与讨论

4 结论

期刊信息