汽-汽再热器内流动与换热特性数值研究

Numerical simulation of flow and heat transfer inshell and tube steam reheater

中文关键词: 工业供热  汽汽换热  强化换热  数值模拟

英文关键词: industrial heating  heat transfer between steam and steam  heat transfer enhancement  numerical simulation

中文摘要:

      为了揭示汽-汽再热器的换热特性，本文首次通过三维数值模拟的方法对汽-汽再热器内的流动、换热及熵产特性进行了研究。结果显示，当高温蒸汽流速较小时，高温蒸汽侧进口处的温度梯度较大，而低温蒸汽侧出口处的温度变化不明显；随着高温蒸汽流速增大，高温蒸汽沿流程的温度梯度逐渐减小，低温蒸汽出口平均温度逐渐增大，同时换热器内局部熵产值逐渐增大；随着管壳式换热器隔板数的增加，低温蒸汽出口平均温度逐渐增大，但增幅逐渐减小。

英文摘要:

      Inordertorevealtheheattransfercharacteristicsofsteamreheater,theflow,heattransfer andentropygenerationcharacteristicsinsteamreheaterwerestudiedbythree-dimensionalnumerical simulationforthefirsttime.Theresultsshowthatwhenthehigh-temperaturesteamflowrateis small,thetemperaturegradientattheinletofhigh-temperaturesteamsideislarger,whilethe temperaturechangeattheoutletoflow-temperaturesteamsideisnotobvious;withtheincreaseof high-temperaturesteamflowrate,thetemperaturegradientofhigh-temperaturesteamalongtheflow directiongraduallydecreases,whiletheaveragetemperatureattheoutletoflow-temperaturesteam graduallyincreases,andthelocalentropygenerationincreases.Withtheincreaseofthebafflenumber inshellandtubeheatexchanger,theaveragetemperatureattheoutletoflowtemperaturesteam increases,buttheriserangedecreases