共查询到19条相似文献,搜索用时 156 毫秒
1.
2.
小冷量变频空调器制冷系统采用单根毛细管的性能分析 总被引:3,自引:0,他引:3
建立了变频空调器制冷系统模拟稳态模型,并用试验验证了模型的可靠性。采用所编的模拟程序,分析了在不同频率时毛细管长度对变频空调器制冷系统性能的影响及原因,指出了选择毛细管时应注意的几个关键问题。 相似文献
3.
房间空调器制冷系统分相模拟研究 总被引:2,自引:1,他引:1
从制冷系统热动力学观点出发,在分布参数的基础上建立了一个房间空调器的稳态模拟模型;分析了换热器的两相流特性及分布,并且针对每一种流态提出相应的热交换关系式。换热器模型基于两相流分析,在动量、能量、质量三大守恒方程基础上引入一个反映两相之间相互关系的关系式以使方程可解。实验表明,与计算机模拟结果吻合较好,玮均相流模型相比,精度有所提高。 相似文献
4.
变频空调器制冷系统充灌量的影响分析和确定原则研究 总被引:6,自引:0,他引:6
建立了变频空调器制冷系统模拟稳态模型,并用试验验证了模型的可靠性。采用所编的模拟程序,分析了在不同频率时,充灌量对变频空调器制冷系统性能的影响及原因,提出了在配有低压储液器情况下,变频空调器制冷系统充灌量的确定原则及储液器最小尺寸的确定方法。 相似文献
5.
6.
7.
变频房间空调器由4个关键部件组成,每一部件又包含影响空调制冷性能(如制冷量、能效比等)的多个相关参数。为了分析空调部件及系统主要性能指标和关键参数的关系,以为空调制冷系统的参数设计与性能分析提供依据,建立了基于Modelica的变频空调稳态性能仿真模型库,包括关键部件模型及制冷工质热力性质和热物理性质计算模型等。基于该模型库建立变频空调制冷系统仿真模型,在MWorks平台上对其进行仿真,仿真结果与理论分析相符。 相似文献
8.
9.
小型轴流风扇为电脑CPU等的重要散热器件。为改善其气动及声学性能,提出了一种新型改进结构。对于原型和改进型,首先应用RNG k-ε湍流模型模拟了稳态流场,进行了静态特性的计算;然后以稳态流场为初始解,运用非稳态大涡模拟模型结合FH-W声学模型、傅里叶变换,计算了风扇进口、出口及内部的监测点噪声;并进行了静态特性和声学性能的实验研究。数值计算与实验结果表明:改进结构在提高静态特性及降噪两个方面效果良好,可在生产实践中加以应用推广。 相似文献
10.
《仪器仪表标准化与计量》2018,(6)
目前,恒定蒸发温度和最小稳定过热度双回路控制方案是制冷系统先进节能控制方案之一。一方面,实际中采用PID控制蒸发器过热度时会产生振荡。另一方面,现有制冷系统稳态模型不适于变负荷工况分析,制冷系统高阶、耦合、非线性动态模型控制分析困难。无模型控制算法不需系统精确模型、适于复杂非线性系统。本文将无模型控制方法应用于双输入双输出制冷机节能控制方案中。仿真结果表明,系统输出稳定且动态性能改善。 相似文献
11.
12.
13.
14.
15.
Finite element analysis with deformation behavior modeling of globular microstructure in forming process of semi-solid materials 总被引:1,自引:0,他引:1
The behavior of alloys in a semi-solid state depends on the imposed stress state and on the morphology of the phase which can vary from dendritic to globular microstructure. An estimation of characteristic behavior in a compression simulation with semi-solid materials (SSMs) is made using the finite element method (FEM) and a proposed, new stress–strain relationship formulation with a separation coefficient. The proposed theoretical models for the compression forming process involve simultaneous calculations performed with solid-phase deformation and the liquid-phase flow saturating the interstitial space. A simulation process considering solidification phenomena is implemented with non-isothermal conditions in two-dimensions. To analyze the compression process of SSMs, a new stress–strain relationship is described, and the compression analysis is performed by using a compressible visco-plastic model for the solid phase and Darcy’s law of fluid flow through a porous medium for the liquid phase. The validity of the proposed models is investigated by comparing the calculated results with experimental data for the relationship between engineering stress and true strain, and the distributions of solid fraction, temperature effective strain, etc., are calculated. 相似文献
16.
17.
18.
19.
Yong-sik Choi Jun-ho Lee Weui-bong Jeong Il-Geun Kim 《Journal of Mechanical Science and Technology》2010,24(7):1371-1377
In refrigerator designs, the linear compressor is preferable to the recipro-type compressor, due to its higher energy efficiency.
The linear compressor’s valve system, however, causes significant noise, not only in the steady state but also in the transient
state. To accurately predict the behavior of the suction and discharge valve system in both states, the interaction between
the fluid flowing through the valves and the structural deformation of the valves needs to be understood. In the present study,
the steady-state behaviors of the valve system were numerically analyzed using ADINA software, which takes fluid-structure
interaction (FSI) into account. This computational analysis thereafter was experimentally validated. The effects of a pre-load
of the conical compression spring on the dynamic characteristics of the valve system also were analyzed. 相似文献