| 摘要: |
| 蓄热技术是太阳能光热利用的重要组成部分，而以水作为蓄热介质的中低温蓄热技术是太阳能热利用系统中的关键技术之一。本文设计了一种新型多孔进口均流器，并在初始水温为70 ℃、进水温度为10 ℃，不同进口流量 （1、2、3、4、5、6 L/min）下，应用理查德森数分析法、混合数分析法及填充效率分析法，与直接进水口结构水箱和三层孔板结构水箱的热特性进行对比实验。实验结果说明：随着进水流量的增加，直接进水口结构水箱和三层孔板结构水箱的填充效率减小，而均流器结构水箱的填充效率先增大后减小。当进水流量为6 L/min时，直接进水口结构水箱、三层孔板结构水箱和均流器结构水箱的理查德森数分别为6、4×104和4×106，填充效率分别为0.534 93、0.584 93和0.814 05。表明均流器可以更好地降低水箱内冷热水的混合程度，提高水箱的热分层效率。 |
| 关键词: 均流器 热分层；蓄热水箱 填充效率 |
| DOI： |
| Received:November 29, 2017 |
| 基金项目:国家自然科学青年基金（51606126）资助项目。 |
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| Effect of Perforated Inlet Structure on Thermodynamic Characteristics of Hot Water Storage Tank |
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Huang Huajie1, Zhang Hua1, Wang Zilong1, Liang Hao2, Chen Yankang1
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| (1.School of Energy and Power Engineering, University of Shanghai for Science and Technology;2.Center of Science and Technology Industrial Development, Ministry of Housing and Urban-Rural Development) |
| Abstract: |
| Heat storage technique is important to solar thermal energy utilization. Furthermore, it a key technology that uses water as a thermal storage medium. To improve the performance of water storage tank, a novel equalizer was proposed in the study. Richardson number (Ri), Mixed number (MIX), and filling efficiency (ξ) analysis method were used to analyze thermal characteristics of the novel equalizer under an initial temperature of 70 ℃, an inlet temperature of 10 ℃, and different flow rates (corresponding to 1, 2, 3, 4, 5, and 6 L/min). The performance of water storage tank with the novl equalizer was compared with the water tanks with the direct inlet structure and three-layer orifice structure. The results indicate that with increases in the inlet flow rate, the ξ of the direct inlet structure and the three-layer orifice structure water tank are reduced while the ξ of the equalizer is initially enlarged and subsequently reduced. When the flow rate is 6 L/min, the Ri for the three modes is 6, 4×104, and 4×106; the ξ corresponds to 0.534 93, 0.584 93, and 0.814 05, respectively. The results demonstrate that the proposed equalizer reduces the mixing process and improve the thermal stratification in the heat storage water tank. In addition, the stratification performance of water tank can be effectively evaluated with filling efficiency because it contains the influences of both temperature and flow rate which are the key factors for thermal stratification in a water tank. Therefore, the filling efficiency can be used to analyze the stratified characteristics of water tank quantitatively and qualitatively. |
| Key words: equalizer thermal stratification thermal energy storage fill efficiency |
