中高温热泵闪发器两相流动模拟研究

发布时间：2018-05-02 22:04

本文选题：闪发器 + 进口参数　；参考：《华中科技大学》2015年硕士论文

【摘要】：喷气增焓技术能够有效提高热泵以及空调的性能,这种技术可以应用于中高温热泵设计中。带闪发器的循环和带中间冷却器的循环是喷气增焓的两种典型应用。现有研究已经证明闪发器循环相比于中间冷却器循环能够多提高10.5%和4.3%的制热量和热性能系数,而闪发器则是闪发器循环的一个重要部件,也是系统稳定的重要环节。本文借助软件对闪发器的闪发过程进行了模拟。在模拟研究中选用了进口流速、进口压力、进口液相体积分数三个进口初始参数和进口角这一结构参数作为研究参数,同时选定进出口有液相体积分数的变化率作为衡量闪发器性能的参数。本文首先建立了闪发的热力学模型,确定以R134a作为研究工质,并一一选取了一些重要参数。对0°入口角的闪发器的气液相以及压力分布做了详细的研究,并总结出了其分布规律,发现闪发器的进出口液相体积分数变化率最多为4.825%。研究进口流速、进口压力、进口液相体积分数的变化对于闪发器的气液相及压力分布的影响,并总结出了三个进口参数的变化对于闪发性能的影响。研究发现进出口液相体积分数变化率会随着进口流速的减小、进口压力的增大而增大,而进口液相体积分数的变化对此的影响则可以忽略。本文重点研究了进口角这一结构因素对于闪发率的影响,并结合进口流速和进口压力进行了详细的分析。研究表明闪发器的进出口液相体积分数变化率随着进口角的增大而增大,在本文研究的进口角、进口压力和进口流速的范围内,这一变化率最多为4.825%。并进一步探究出了进口角对进出口液相体积分数变化率的影响会随着流速的减小和压力的增大而减弱。本文对中高温热泵闪发器的研究可以为闪发器的设计提供重要的参考意义。
[Abstract]:The enthalpy increasing technology can improve the performance of heat pump and air conditioning effectively, which can be used in the design of medium and high temperature heat pump. Cycle with flicker and cycle with intercooler are two typical applications of enthalpy of jet. It has been proved that flash cycle can increase heating capacity and thermal performance coefficient by 10.5% and 4.3% more than that of intercooler cycle. Flash is an important part of flash cycle and an important link of system stability. In this paper, the flicker process is simulated by software. In the simulation study, the structure parameters of inlet velocity, inlet pressure, inlet liquid volume fraction and inlet angle are selected as the study parameters. At the same time, the change rate of the volume fraction of liquid phase in the inlet and outlet was chosen as the parameter to measure the performance of the flicker. In this paper, the thermodynamic model of flash is established, and R134a is chosen as the working medium, and some important parameters are selected one by one. The gas-liquid phase and pressure distribution of the flicker with 0 掳inlet angle is studied in detail, and its distribution law is summarized. It is found that the maximum change rate of the volume fraction of the liquid phase in the inlet and outlet of the flicker is 4.825%. The effects of inlet flow rate, inlet pressure and inlet liquid volume fraction on the gas-liquid phase and pressure distribution of the flicker were studied, and the effects of the three inlet parameters on the flash performance were summarized. It is found that the change rate of the volume fraction of the inlet and outlet liquid phase will increase with the decrease of the inlet flow rate and the increase of the inlet pressure, but the effect of the change of the volume fraction of the inlet liquid phase on the change can be neglected. In this paper, the influence of inlet angle on flash rate is studied, and the inlet velocity and inlet pressure are analyzed in detail. The results show that the change rate of liquid phase volume fraction increases with the increase of inlet angle. In the range of inlet angle, inlet pressure and inlet velocity studied in this paper, the maximum change rate is 4.825%. It is found that the influence of inlet angle on the change rate of volume fraction of inlet and outlet liquid will be weakened with the decrease of flow rate and the increase of pressure. In this paper, the research of medium-high-temperature heat pump flicker can provide an important reference for the design of flicker.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU83

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