流量与风机转速对分体式空调室内机的影响

围绕分体式空调室内机流场特性进行研究与分析,尝试运用计算流体力学(CFD)方法对分体式空调室内机空气流动状态进行数值仿真,分析空调出风时空气流量与贯流风机转速对整个流场流动的影响,研究了相关变化规律为相关研究提供参考[1-6].     

Refrigerant charge prediction based on start-up characteristics of an air conditioner using a gray box model

The refrigerant charge is one of the important parameters that determines the performance and power consumption of an air conditioner. Refrigerant charge fault occurs because of refrigerant leakage as well as initial charge fault. Since refrigerant charge loss resulting from a leakage is a gradual process, it is difficult to detect it in an early stage of leakage. In this study, the refrigerant charge of an air conditioner was estimated using predictions of its start-up characteristics obtained from a gray box model. The dynamic characteristics of heat exchangers were assumed to vary with the refrigerant charge as well as operating conditions. Furthermore, the moving boundary method was used to determine the transient behavior of the refrigerant in the condenser and evaporator. Additionally, correction factors were employed in the heat exchanger model. The correction factors were correlated under training conditions of the air conditioner, and the accuracy of the model was verified by comparing its predictions with experimental results under test conditions. The condensation temperature was selected for estimating the refrigerant charge amount. The refrigerant charge could be estimated within a prediction error of 5 % by minimizing the differences between simulation and experimental data. The proposed method can be used for predicting the refrigerant charge and detecting faults in air conditioners during refrigerant leakage on the basis of the start-up characteristics of the air-conditioners.

     

汽车空调管清洗工艺

介绍汽车空调管软管、硬管的清洗工艺.通过装配生产工艺改进,提出了工序控制最佳方案,乳化液清洗系统的设计,从而实现了可生产性成本的清洗技术.     

Scheduling algorithms for an air conditioner manufacturing system composed of multiple parallel assembly lines

This paper focuses on a scheduling problem in a manufacturing system composed of multiple parallel assembly lines. There are multiple orders to be processed in this system, and each order is specified by the product type, the number of products to be processed, and the due date. Each product is composed of two types of subassemblies, one unit of an external subassembly and one or more units of an internal subassembly. In the system, the parallel assembly lines are not identical, and certain lines are designated for certain product types. We present heuristic algorithms for the scheduling problem with the objective of minimizing total tardiness of orders. For an evaluation of the performance of the suggested algorithms, computational experiments are performed on a number of problem instances and results show that the suggested algorithms work better than the method used in a real manufacturing system.     

面向机电产品回收的选择性拆卸技术

合理选择拆卸方法是提高废旧机电产品回收率的重要保证。研究和构建了机电产品面向回收的选择性拆卸模型,提出了绿色制造系统的优选方法,同时通过废旧产品选择性拆卸的递归算法,以BD-148冰柜产品作为实例研究,最终获得最经济的回收方案。     

U型布局的拆卸线平衡问题及其求解算法研究

建立以精益生产为准则的多目标U型拆卸线平衡问题模型,并提出了一种改进的人工蜂群算法求解该问题。通过利用蜜蜂对蜜源进行标记完成自身学习过程,有效地改善了蜜蜂寻找蜜源的能力。为避免算法搜索过程中陷入局部最优,采取模仿其他蜜蜂的搜索行为打破僵局,并将改进人工蜂群算法应用于求解文献中的实例,通过对比表明改进人工蜂群算法可以寻找到更优的解,从而验证了算法的可行性。最后,将改进人工蜂群算法用于U型布局求解,将U型布局结果与直线型布局进行对比,体现了U型布局的优越性。     

Investigation study on the flow-induced noise by winglet and shroud shape of an axial flow fan at an outdoor unit of air conditioner

Journal of Mechanical Science and Technology - Axial flow fans of outdoor units are equipped with specially shaped winglets and shroud for reduction of the flow-induced noise. In this study, the...     

Reliability evaluation of scroll compressor for system air conditioner

This study presents a reliability evaluation method of the scroll compressor for system air conditioner. After conducting reliability target determination and failure analysis (failure mode and effect analysis) on the scroll compressor, the significance of the stress factors affecting wear (main failure mode) is evaluated using design of experiments. Specifically, wear is estimated under various test conditions using analysis results. The lifetime of the scroll compressor is estimated using the data of zero-failure accelerated life test performed under various test conditions. The result satisfies the warranty lifetime of the scroll compressor. Finally, the procedure of reliability determination test for the scroll compressor is briefly proposed.     

CO2空调热泵机组管路的安全性分析

CO2是制冷空调业中最有潜力的自然工质之一.从内压变化、管路壁厚和管径之间的关系出发,通过分析不同种类材料性能对CO2跨临界热泵系统管路系统可靠性的影响,发现管路系统的可靠性与管径的大小成反比,与管壁厚度和材料的许用应力成正比,找出了高压下系统运行可靠度的变化规律及提高可靠度的措施.     

Petri网在产品拆卸序列规划中的应用研究

拆卸是废旧产品中零部件再制造及材料回收再利用的重要环节,拆卸过程规划的目的就是为了寻找最优的拆卸序列。这里以Petri网为工具,建立了包括零部件回收价值及拆卸成本在内的产品拆卸Petri网模型,对模型进行求解,得到了满足需求约束的最佳拆卸序列。     

CO2空调热泵机组管路的安全性分析

CO2是制冷空调业中最有潜力的自然工质之一。从内压变化、管路壁厚和管径之间的关系出发。通过分析不同种类材料性能对CO2跨临界热泵系统管路系统可靠性的影响,发现管路系统的可靠性与管径的大小成反比。与管壁厚度和材料的许用应力成正比。找出了高压下系统运行可靠度的变化规律及提高可靠度的措施。     

Parallel disassembly sequence planning for complex products based on fuzzy-rough sets

The goal of the parallel disassembly sequence planning (PDSP) is to find an optimal feasible disassembly task sequence with many constraints. Due to the PDSP of complex product is restricted by various factors, the DPSP problem is not easily solved in a general form. In order to reduce the time complexity, this paper presents a PDSP method based on fuzzy-rough sets. Five disassembly factors including assembly constraints factor, disassembly precedence factor, disassembly time factor, disassembly tool factor, and combination type factor are defined and formulated. In light of the characteristics of PDSP, the fuzzy-rough set mapping model of parallel disassembly is constructed. The components to be disassembled are taken as knowledge universe, and disassembly membership function as objection function is defined as the indiscernibility relation. Then, the fuzzy-rough set mapping model of parallel disassembly is adopted to generate the optimum parallel disassembly sequence. Finally, two examples validate the proposed method.     

空调器配管断裂失效分析及可靠性改善

基于国内某空调制造企业的产品研发实践，对目前空调器配管几种主要的断裂失效形式进行了总结。分析了失效发生的原因，提出了相应的解决思路。通过案例对配管断裂的故障分析和应对策略进行了讨论，相关分析结论对提高配管工作可靠性具有一定的工程指导意义。     

基于加权PMV和EQT的改舱客机地面空调最佳送风温度

为改善飞机地面空调恒定温度送风所造成的改舱客机舱内乘客热舒适性不佳的问题,建立了改舱后的Boeing 737客舱模型,并通过实验舱对仿真模型进行了试验验证,证明了此模型的合理有效性.在此改舱模型的基础上,运用CFD技术,模拟仿真出地面空调不同送风温度下,改舱客机的风速场与温度场,且针对改舱客机空调送风口与乘客座位距离不...     

Evaluating the performance of an ERP system based on the knowledge of ERP implementation objectives

Success is often defined as a favorable or satisfactory result or outcome. Since the objectives of an Enterprise Resource Planning (ERP) implementation project reveal exactly the states of an ERP system, which managers wish to realize, the knowledge of these objectives can indicate how outcomes of an ERP system execution must be measured in the ERP success analysis. This paper proposes a comprehensive framework for assessing the performance of an adopted ERP system. Based on the knowledge of ERP implementation objectives, the framework can systematically identify the appropriate ERP performance indicators, construct the performance indicator structure, and set up consistent evaluation standards for facilitating the complex ERP performance evaluation process. A real-world example demonstrates the feasibility of the proposed framework.     

基于Patran空调室外机支架的有限元分析

根据《空调器室外机安装用支架规范》对空调室外机支架进行了强度分析,采用Patran有限元软件进行了静力分析和屈曲分析,分析了在规范载荷下的强度和稳定性分析,计算结果表明强度和可靠性满足要求。     

空调四通转换阀体的感应钎焊

介绍感应加热电源在铜与不锈钢钎焊方面的应用,并结合具体产品提出了适合产品焊接的感应电源类型和具体的工艺参数组合。     

汽车空调吹脚风门的改进设计与试验验证

以汽车空调吹脚风门为研究对象,首先通过对空调系统CFD的仿真分析,得到吹脚风门的速度矢量图、静压图和温度分布图,为吹脚风门的改进设计提供依据。然后,对吹脚风门的导流面、控制风门开度的机构以及连动机构进行改进设计,并对改进后的结构进行刚度校核。结果表明,在满足刚度要求的情况下,吹脚风门质量明显减轻。最后通过风门扭矩试验得到原始吹脚风门和改进后吹脚风门的负载扭矩曲线,将二者进行比较分析,从而验证改进方案的有效性和准确性。     

柜式空调多翼离心风机的数值模拟

采用二维粘性数值模拟方法对某柜式空调多翼离心风机进行数值模拟，分析多翼离心风机的内部流场，预测风机的风量静压性能，预测结论与试验结果较接近，说明柜式空调多翼离心风机设计时可以采用数值模拟技术，以减少实物模型试验，降低产品开发成本。     

基于Pareto蚁群算法的拆卸线平衡多目标优化

为提高产晶拆卸效率,针对拆卸线平衡问题建立了数学模型.该模型以最小拆卸线闲置率、负荷均衡和最小拆卸成本为优化目标.结合拆卸线平衡问题的具体特点,提出了一种改进的基于Pareto解集的多目标蚁群优化算法.算法采用小生境技术,引导蚂蚁搜索到分布良好的Pareto最优解集,并以被支配度和分散度为个体评价规则.实验测试结果表明了该算法的可行性.最后,结合企业生产实际,给出了所提模型与算法的具体应用.