| 引用本文: | 吴小舟,赵加宁.U型翅片管换热器传热单元数计算式[J].哈尔滨工业大学学报,2012,44(4):71.DOI:10.11918/j.issn.0367-6234.2012.04.015 |
| WU Xiao zhou,ZHAO Jia ning.Approximate formulas of number of transfer unit of U shaped fin tube heat exchangers[J].Journal of Harbin Institute of Technology,2012,44(4):71.DOI:10.11918/j.issn.0367-6234.2012.04.015 |
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| 摘要: |
| 为了得到U型翅片管换热器传热单元数计算式,以U型翅片管换热器为研究对象,通过建立翅片管换热模型,推导出了逆流和顺流2种流体流动趋势的传热单元数计算式(NTU计算式)．分别采用推导出的传热单元数计算式(ε NTU法)和前人推导出的平均温差关系式(LMTD法)计算U型翅片管传热系数,并进行对比分析．结果表明,当进水温度为45～60 ℃,热水流量为30～110 kg／h时,由ε NTU法和LMTD法计算出来的翅片管传热系数相差很小．所推导出来的U型翅片管换热器传热单元数计算式是合理的． |
| 关键词: U型翅片管换热器 翅片管传热系数 ε NTU法 LMTD法 |
| DOI：10.11918/j.issn.0367-6234.2012.04.015 |
| 分类号:TU833 |
| 基金项目:国家“十一五”科技支撑计划重大项目(2006BAJ01A00) |
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| Approximate formulas of number of transfer unit of U shaped fin tube heat exchangers |
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WU Xiaozhou, ZHAO Jianing
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School of Municipal and Environmental Engineering, Harbin Institute of Technology, 150090 Harbin, China
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| Abstract: |
| To obtain the formulas of number of transfer unit (NTU) of U shaped fin tube heat exchangers, a U shaped fin tube heat exchanger is taked as research object. Approximate NTU formulas of number of transfer unit are derived by establishing heat transfer model of U shaped fin tube when the trend of two flows in fin tube heat exchanger is counter and parallel, respectively. Subsequently, the heat transfer coefficients of fin tube are compared and analyzed by effectiveness number of transfer unit method (ε NTU method) and logarithm mean temperature difference method (LMTD method) when inlet water temperature is from 45 ℃ to 60 ℃ and water flow rate is from 30 kg／h to 110 kg／h. The results show that, the difference of the heat transfer coefficients respectively calculated by ε NTU method and LMTD method is so small that these NTU formulas are valid |
| Key words: U shaped fin tube heat exchanger heat transfer coefficients ε NTU method LMTD method |
