汽车空调环境模拟试验技术综述

本文系统地阐述了汽车空调系统环境模拟试验技术及相关设备组成，结合对国内汽车空调环境模拟试验室的技术资料分析和实寺考察，提出了汽车空调性能模拟试验技术的发展动向和趋势。     

基于环境模拟的汽车热平衡试验研究

以环境模拟试验中的热平衡试验为主要研究对象,对该试验的国标及企标进行对比研究,利用试验室的环境仓和转鼓等硬件设施,进行了多车型的整车热平衡环境模拟试验。从热平衡、环境温度对试验结果影响、光照对试验结果影响、环境模拟试验与道路试验的比对等方面进行分析,进而对目前的热平衡试验标准提出了改进意见。     

汽车环境风洞实验室的性能评价与分析

近年来,汽车环境风洞试验室在整车性能研发中的作用越来越受到研发人员的重视,如何评价试验室本身的模拟精度,目前还并未形成完整的评价体系。基于国内某风洞试验室的实测案例,本文对环境风洞试验室气动参数的含义、测量方法、数据分析进行了详细阐述;展示了环境参数的测试结果,并与环境舱参数进行对比,结果表明环境风洞的空气动力学特性对环境模拟指标具有重要影响。     

基于组态软件的汽车空调整车环境模拟试验室的研制

介绍汽车空调整车环境模拟试验室的原理、结构的研制及应用。     

商用车整车环境模拟试验室能力匹配设计方法

整车环境模拟试验室包括高低温环境舱和重型转毂两套主要的设备,这两套设备能力的规划不仅关系到投资成本、基建成本、运营成本、项目实施的难度等,更决定了未来商品开发的试验能力。本文从商品开发的需求出发,结合重要设备的原理、结构、特性、成本,合理的规划了转毂电机、环境舱制冷系统、阳光模拟系统以及环境舱新风系统的设备能力,以保障设备投资项目在顺利开展的前提下,降低各项成本,提高效率。     

沥青混凝土拌和站粉料的可控加湿搅拌方案

对沥青混合料搅拌设备现有的加湿搅拌模式进行了阐述和分析,并指出了现有方案的不足,随后结合粉尘的特点提出了一种可控制的加湿搅拌方案.事实证明:该方案能有效解决粉尘类物料的运输及对环境造成污染的问题,对同类设备的改造具有现实意义.     

重庆交通科研设计院结构动力工程所

重庆交通科研设计院结构动力工程所是集科研、设计、开发、试验、检测为一体的经济实体，拥有一支高素质的科技队伍。我所现有的桥梁结构动力试验室是交通部“九五”大型基建项目，一期工程投资近6000万元，是目前中国投资规模最大、设备技术水平和试验能力最先进的结构抗震和振动动力学试验室之一。其中六自由度大型地震模拟试验台阵系统是目前国内外唯一的由1个固定台和1个移动台组成台阵的大型高性能三轴向地震模拟试验系统，台阵的组合工作模式及台子轨道移动方式均属世界首创，并通过国际招标由英、美有关公司专门定制完成。配置的多通道结构试验机系统，具有6个大吨位结构试验作动器，也是目前国内规模最大的结构试验系统之一；同样采用了目前国际上最先进的数字控制系统，可进行多通道协调加载试验，具有静载、动载、拟静力、拟动力以及环境模拟试验控制功能。其环境模拟试验功能，可以在试验室环境真实地模拟结构构件危险部位在真实环境工作条件下的应力状况，从而研究其工作性能和破坏机理，其功能是目前国内其他试验室同类系统所没有的，可为广泛领域内的结构动力学研究提供必要的条件，从而使得进行结构动力学的一些基本问题的试验研究成为可能，总体技术水平达到国际先进水平。     

轿车车身淋雨试验室的设计与计算

为评价车身的防雨密封性，须建立淋雨试验室。介绍了淋雨试验室的组成、原理、设备、管路、喷嘴的设计与计算，按此方法设计可以达到国际GB／T12480－90规定的要求。     

曲轴箱通风口海拔模拟条件对柴油机运行的影响

针对柴油机进排气高原环境模拟装置在应用中存在的问题,基于活塞、活塞环、气缸套形成的几何密封结构,确定了缸内气体向曲轴箱流动形成的气室,进一步构建环间气体窜出流量的数学模型,运用迭代计算方法推演计算了各个气室气体压力和气体流量的变化,分析了曲轴箱通风口与进排气管路模拟海拔不一致时活塞窜气影响和增压器轴系润滑密封问题,最后进行试验验证.研究结果表明,海拔4 500 m时曲轴箱通风口处于相同海拔环境条件,曲轴箱通风口窜出废气流量要比处于试验室环境条件时窜出气体流量大,增加0.4 L/min.此外,曲轴箱通风口处于试验室环境条件时,压气机背盘两侧气体压力差异会使间隙空间形成很大的负压,导致润滑增压器轴承的机油窜入进气管路.     

汽车淋雨试验室结构及设计

<正>汽车淋雨试验室主要是用来模拟自然降雨环境,用于测试汽车的防雨密封性能,是新车下线必不可少的检测设备。淋雨试验室主要由淋雨室、输送板链、喷淋系统、淋雨控制系统、吹干系统组成。本文介绍了淋雨试验室设计中各主要参数及设备设计和选型的依据,为淋雨试验室设计在理论计算上提供参考。     

Experimental study on performance of automotive air conditioning system using R-152a refrigerant

Recently, as climate changes have manifested worldwide, every country is making efforts to prevent ozone depletion and global warming. In the automotive industry, R-134a refrigerant is widely used in air conditioning systems because it has zero ozone depletion potential (ODP). Unfortunately, its global warming potential (GWP) is high. Therefore, alternative refrigerants are needed as a replacement for R-134a. R-152a is considered to be one of the better alternative refrigerants due to zero ODP and low GWP. In this paper, the performance of an automotive air conditioning system using R-134a and one using R-152a are compared experimentally at the bench level. The experimental apparatus simulated a real automotive air conditioning system consisting of a cabin and engine room structure. The cooling capacity, condensing capacity, coefficient of performance (COP) and power consumption characteristics of the automotive air conditioning system are evaluated by changing the air velocity entering the condenser and the compressor rotation speed with the optimized refrigerant charge amount. Also, the performance of the R-152a system was investigated by changing the thermostatic expansion valve which is set of values. The results of this study show that the R-152a system is slightly better than the R-134a system, not only under driving conditions but also under idling condition. R-152a refrigerant thus shows promise as an alternative refrigerant to replace the current standard, R-134a, in automotive air conditioning systems.     

热带沙漠气候环境汽车空调系统的开发

阐述热带沙漠气候环境下汽车空调制冷性能的研究,对热带沙漠气候环境下整车空调系统的舒适性温度指标进行分析探讨;并以某车型出口迪拜的空调系统改进性开发为实例,从系统架构、性能指标、部件布置和试验验证等方面行介绍。     

城市轨道交通通风空调设备选型附加系数探讨

已运行的轨道交通通风空调设备,由于选型存在不合理因素,有些不能较好地适应系统的实际需求,而设备选型附加系数取值的合理性是重要原因之一。先对现行设计规范、手册、技术措施、轨道交通工程设计技术要求对设备选型附加系数取值的规定进行了分析;然后对各种通风空调设备分析各参数需要修正的原因、各参数间相互关联对修正的影响;最后提出各类设备需要修正的主要参数及其附加系数的建议值。     

Analysis of the performance of the evaporator of automotive air conditioning system

The purpose of this research was to establish a theoretical model for the evaporator of automotive air conditioning system and conducting simulations to evaluate the effect of operation parameters, environmental conditions, and design parameters on the performance of evaporator. An automotive air conditioning system primarily consists of four components: the compressor, the condenser, the refrigerant controller, and the evaporator. The refrigerant flow in the evaporator can be divided into two regions: the evaporating region and the superheat region. The refrigerant in the first region is a two-phase flow, while the refrigerant in the latter region is in the state of superheated vapor. The air flowing through the interior of the evaporator can also be divided into two zones: the unsaturated zone and the saturated zone. Water vapor is condensed in the saturated zone while in the unsaturated zone, no water condenses. Because the refrigerant flow and the airflow are perpendicular to each other, the distribution of refrigerant in the evaporating region and the superheat region does not coincide with the distribution of air in the unsaturated zone and the saturated zone. This study examines the effects of different design parameters, environmental conditions and operating parameters on the cooling capacity and superheat of an air conditioning system. Design parameters include the length of the refrigerant channel, the length of the air channel, and the thickness of the fins. Environmental conditions include the air inlet temperature and absolute humidity. Operation conditions include the refrigerant inlet enthalpy, inlet air flow rate, and refrigerant mass flow rate. Results of simulation demonstrated that fins with 50 micron meters width has the greatest cooling capacity for identical outer dimensions; thicker or thinner fins only decreased cooling capacity. Under different outer dimensions, longer refrigerant tubes and air channels created a greater cooling capacity. However, the increase in cooling capacity becomes less and less if the refrigerant flow was fixed because the heat transfer capability of the gaseous refrigerant was limited. In this study, an increase of 19% in cooling capacity can be reached as the length of refrigerant channels was increased, and the increased length of the air channels can promote the cooling capacity by 22%. Besides, it was found in this study that a decrease in the refrigerant inlet enthalpy, the inlet air flow rate, the air inlet temperature, and the inlet absolute humidity, or an increase in the refrigerant mass flow rate, would extend the superheat region and decrease the refrigerant’s superheat. It was also found that the cooling capacity of air conditioners is extremely sensitive to changes in the refrigerant mass flow rate and the inlet enthalpy, and variations more than 50% were found in the operating ranges examined in this study. However, changes in the inlet temperature, absolute humidity, and inlet air flow rate only resulted in variations between 10% and 20% in the examined ranges of conditions. Finally, a correlation among these variables and the simulated cooling capacity was obtained in this study, enabling the relevant researchers to evaluate automotive air conditioning performance under different environmental conditions and operation parameters more easily.     

汽车空调系统与发动机冷却系统的耦合分析

建立汽车空调系统与发动机冷却系统数学模型,对两系统进行耦合计算,与实验结果对比表明:仿真与实验结果吻合较好,能够满足工程设计的需要。     

冻土层上限下移对桥梁桩基轴向承载性能的影响分析

在气候变暖和人类活动的共同作用下,多年冻土层上限逐渐下移.现依托青海某高速公路上的一座中桥,在不同冻土层上限位置方案下对其桩基轴向承载性能进行数值模拟,通过将模拟计算出的桩基轴向承载性能指标进行对比分析,得到多年冻土区桥梁桩基轴向承载性能指标随冻土层上限下移的变化规律.其成果可为多年冻土区桥梁桩基的设计、施工与加固处理提供一定参考.     

汽车空调系统工作原理及故障诊断

作为汽车的重要组成部分,空调系统一直都在汽车中扮演着重要角色。驾驶员可以借助空调系统,对车内环境(如温湿度等)进行调节,既可提高车内人员舒适度,还可消除附着在挡风玻璃的雾气,避免影响驾驶员的视线。但是经过长时间使用以后,汽车空调系统不可避免地会出现各种问题。文章首先对空调系统的运行原理进行了简单描述,然后分别介绍了空调系统制冷量不足、不制冷以及制冷效果时好时坏三种情况下的故障诊断。     

考虑人体热调节的乘员表面温度分布及车内热环境的数值仿真和试验

为研究在瞬态变化的车内热环境下的人体表面温度分布情况及舱内热环境对乘员热舒适性评价的影响，以冬季某轿车乘员舱内热环境为研究对象，实车测试暖风系统开启后车内热流场的动态变化，建立乘员舱流场和温度场的瞬态仿真模型，综合考虑环境参数和人体新陈代谢等因素以及车内热环境与人体热调节模型间的耦合关系。研究结果表明：仿真计算与试验测试结果吻合良好；基于人体热调节模型的仿真计算可得到车内热环境变化下的乘员皮肤温度变化结果；开启暖风后，车内温度在高度方向和前后排乘坐空间均存在显著的不均匀性，后排的热环境均匀性更好；人体散热对乘员舱温度场分布的影响可以忽略，而暖风使不同位置处乘员的皮肤温度上升程度存在明显差异。     

DD6120HCI大客车热力特性的实验研究

本文对大客车热力特性进行了实验研究，实验内容包括车厢气密性，客车热力特性，空调系统制冷能力以及车围结构导热性等。本文还讨论了汽车稳太热载荷及车围结构导热的计算方法。     

客车空调系统对客车舒适度的影响分析

客车空调在满足驾乘人员舒适度的同时,其运行产生的噪声和振动也影响客车的舒适性。本文就此加以论述,并提出解决措施。