Thermodynamic Modeling of Screw Expander in a Trilateral Flash Cycle
Thermodynamic Modeling of Screw Expander in a Trilateral Flash Cycle
复制标题
三边闪蒸循环中螺杆膨胀机的热力学建模
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
A. Brümmer
中科院分区：
文献类型：
--
作者：
H. Vasuthevan;A. Brümmer
本文主要研究了螺杆膨胀机在三边闪蒸循环中的热力学模型。在这个过程中，液体从低压泵送到高压，然后加热到接近饱和点。螺杆膨胀机的工作腔内填充的不是通常的蒸汽工作流体，而是热液体。在灌装过程中，由于过程快速，液体压力下降到饱和压力以下，而温度几乎保持不变。因此液体处于亚稳态。液体吸入稳定状态，因此在填充和膨胀过程中由于其增大的腔体体积而汽化。因此，在工作室内存在两相混合物，即蒸汽和液体。所提出的模拟包括计算每个腔室内的流体状态处于热力学平衡状态，这假设相之间存在足够的传热以在一个时间步长内达到稳定状态。热力学模拟进行了使用水作为工作流体的示范螺杆膨胀机几何。将模拟结果与相应的两相螺杆膨胀机的实验测量结果进行了比较，证明了热力学模型的结论。
The present paper focuses on the thermodynamic modeling of screw expanders in a trilateral flash cycle. In this process a liquid is pumped from low to high pressure and then heated up close to saturation point. Instead of a vaporous working fluid as usual, a hot liquid is filled in the working chamber of the screw expander. During the filling process the pressure of the liquid drops below the saturation pressure while the temperature remains almost constant due to a fast process. Hence the liquid is in a metastable state. The liquid aspires a stable state and therefore is vaporized during the filling and expansion process due to its increasing chamber volume. Thus a two-phase mixture, vapor and liquid, exists in the working chamber. The simulation presented includes the calculation of fluid states within each chamber to be in thermodynamic equilibrium, which assumes that a sufficient heat transfer exists between the phases to reach a stable state within a time step. Thermodynamic simulations are carried out using water as the working fluid for an exemplary screw expander geometry. The conclusive assessment of the thermodynamic model is demonstrated by the comparison of the simulation results with available experimental measurement results for a corresponding two-phase screw expander.