两源间定常态能量转换热机换热器管内流速的选择关系

Relational Expression of Selecting Flow Velocity in Pipes of a Heat Exchanger For a Certain Thermal Machine of Enrgy Conversion between Two-Heat-Sources

本文从一种换热总热阻的经验关系式出发，根据有限时间热力学得到的两源定常态能量转换热机最佳传热面积比．得到了换热器管内流速的关系式。该关系式对热机的论证及实际工程设计有一定的指导意义。

From a experience relation expression on total thermal resistance of heat exchange, the ralation expression of flow volocity in pipes of a heat exchanger has been derived according to the optimal ratio of heat-transfer surface for a certain thermal machine of energy conversion between two-heat-sources obtained by the finite time thermodynamics. The expression has a certain guiding meaning to verify the thermal machine and design in practical engineering.