最小二乘支持向量机在空调温控系统中的应用

温度控制系统是空调控制系统的核心,传统的温控系统采用PID调节和普通模糊控制。利用最小二乘支持向量机（Least Squares SVM,LS-SVM）理论,建立模糊控制器,通过与一般模糊控制仿真实验结果进行比较,验证了其在温控系统的有效性。     

Effects of temperature dependent air properties on the performances of a thermal actuated slider

Thermal actuated sliders have been widely used in today's hard disk drive industry for its advantages of easier control of flying height (FH) and less risk of contacts with the disk over the conventional slider. In this paper, we used a coupled-field analysis method, which includes an air bearing model, a heat transfer model and a thermal-structural finite element (FE) model to investigate the flying and thermal performances of a thermal actuated slider at various environmental temperatures. We also proposed a generalized mean free path model to incorporate various molecular dynamics models and consider temperature effects of the mean free path. Some temperature dependent air properties, such as the viscosity and the thermal conductivity are also considered in the simulation. It is found that the mean free path is a crucial parameter in determine air bearing and heat transfer across the head-disk interface (HDI). Our simulation results also show that the temperature effects of the viscosity and the thermal conductivity are contrary to that of the mean free path, which limit the variations of air bearing and heat transfer as the environmental temperature increases. However, their temperature effects still need to be considered for an accurate simulation, especially when the disk drives operate in a wide temperature range.     

基于PLC的地铁通风空调控制系统设计

随着计算机控制技术的迅速发展,以微处理器为核心的可编程序控制器已逐步取代继电器,普遍应用于各行各业的自动化控制领域.该文主要探讨了AB公司的PLC及其网络技术在西安地铁一号线通风空调控制系统中的应用,详细阐述了通风空调控制系统的组成与控制策略,并介绍了PLC控制程序与触摸屏上位监控程序的开发设计.该控制系统已在西安地铁实际工程项目中成功应用,取得了良好效果.     

Influencing factors on thermal comfort and biosignals of occupant-a review

Journal of Mechanical Science and Technology - Thermal comfort has become one of the most important factors to be considered for the working efficiency and health of occupants in an indoor space....     

AVELING自卸车自动变速器的检测分析与故障诊断

以AVELING自卸车的自动变速器为例,介绍工程机械传动系统中广泛采用的液力自动变速器基本的检测、分析与故障诊断方法。     

工程自卸车刚柔耦合建模及空载板簧刚度优化

以某工程自卸车为研究对象,运用ADAMS/Car软件建立包括柔性车架、轮胎、驾驶室前后悬架、车厢、发动机和转向系等子系统的工程自卸车刚柔耦合模型。根据国标建立了H级路面,在相同的路面、车速和载重下,分析了前悬架板簧刚度对自卸车平顺性的影响,为自卸车平顺性的研究提供了一些参考。     

基于递阶结构的变风量空调控制系统设计

变风量空调系统结构复杂,规模庞大,而且变量多,耦合性强,还存在各种不确定因素。传统的自动控制方法大都采用控制参数固定的方法,虽然能够满足系统的稳定性运行,但会带来很大的能量浪费。该文设计一种递阶方式的控制方案,以变风量空调系统能耗最小为优化目标,使其在满足舒适性和稳定性的同时,减少系统的运行能耗,达到最佳的节能效果。     

基于AutoCAD对象技术的组合式空调机组CAD

运用面向对象技术对组合式空调机组CAD系统中零部件设计部分进行开发是实际所需，本文论述了ObjectARX和面向对象技术在零部件设计中的运用，包括总体结构、系统实现、图形数据库以及界面设计。     

Experimental research on thermal comfort in the university classroom of regular semesters in Korea

This research has investigated physical variables affecting indoor thermal comfort and subjective responses of thermal comfort of students in a university in Korea in which the weather is oceanic temperate climate, and has been performed to contribute to the research fields of Sustainable Thermal Standard and Adaptive Thermal Comfort (ATC). This research is based on the ISO 7730-2005 standard and the ATC theories and 4 main variables of PMV such as dry bulb temperature (Ta), relative humidity (RH), black bulb temperature (Tg), and air velocity (Va) are measured once a week during two regular semesters. A clothing insulation, a thermal sensation vote (TSV), an acceptability of thermal environment, and a preference for cooling and heating are investigated at the same time using a questionnaire. This study was carried out for 26 weeks during the spring season, from March to June 2009, and the autumn season, from September to December 2009. The main achievements of this study are as follows. Monthly Mean Outdoor Temperature (MMOT) and Operative Temperature (OT) in the classroom during research periods are 7.4∼23.3°C and 17.5∼29.0°C, respectively. The acceptability ratio of thermal environment shows over 80% when the range of OT in the classroom is 17∼25°C, and the range can be applicable to operative index of heating and cooling of classroom. The mean TSV of respondents is almost “neutral (0)” when the PMV in the classroom moves to “neutral (0)” and “slightly cool (−1)”, and the TSV is almost “+1.5” when the PMV moves to “slightly warm (+1)”. The acceptability ratio of thermal environment is slightly different from ASHRAE Standard 55-2004. So it is necessary to more investigate standard range of acceptability of thermal environment in oceanic temperate climate region using much more databases.     

An experimental study on the performance of air/water direct contact air conditioning system

Direct contact air conditioning systems, in which heat and mass are transferred directly between air and water droplets, have many advantages over conventional indirect contact systems. The purpose of this research is to investigate the cooling and heating performances of direct contact air conditioning system for various inlet parameters such as air velocity, air temperature, water flow rate and water temperature. The experimental apparatus comprises a wind tunnel, water spray system, scrubber, demister, heater, refrigerator, flow and temperature controller, and data acquisition system. The inlet and outlet conditions of air and water are measured when the air contacts directly with water droplets as a counter flow in the spray section of the wind tunnel, and the heat and mass transfer rates between air and water are calculated. The droplet size of the water sprays is also measured using a Malvern Particle Analyzer. In the cooling conditions, the outlet air temperature and humidity ratio decrease as the water flow rate increases and as the water temperature, air velocity and temperature decrease. On the contrary, the outlet air temperature and humidity ratio increase in the heating conditions as the water flow rate and temperature increase and as the air velocity decreases.     

特征技术在组合式空调机组CAD系统中的应用

特征技术是实现CAD／CAM集成的关键技术之一，本文主要介绍特征建模技术在组合式空调机组CAD图形系统中的具体运用，并介绍系统的实现方法。     

基于ANSYS Workbench空调配管模态分析与优化

以某品牌空调压缩机配管为研究对象,利用ANASYS Workbench软件模态计算方法对空调压缩机配管进行动态特性研究。利用Pro/E对空调压缩机配管建立动力学模型,根据ANSYS软件网格划分功能建立其有限元模型并进行模态分析,获得压缩机配管前10阶的固有频率。通过将其与外界激励频率进行校核,获得避免共振产生条件的可行性。在此基础上提出相应的改进措施,从而有效保障管道的安全使用以及有效的控制室外机的噪声。     

基于PLC空调蒸发器成型机控制系统的设计

随着电气自动化的不断发展和推广,传统的控制方式已经不能满足现在工业的发展。该文针对蒸发器成型机的工作要求,进行控制上的改进,采用PLC控制,使其拥有触摸屏进行手动和自动的控制和监测,安全光幕进行保护,投入生产使用后产生了良好的经济效益。     

The effect of thermal conductivity and friction coefficient on the contact temperature of polyimide composites: Experimental and finite element simulation

In this work, the Finite Element Method is used to simulate and visualize the maximum contact temperature of polymer composites under ring-on-block tribolgical test. The simulated temperatures are in good agreement with the experimental results under all testing conditions. The error values between the experimental and simulated temperature are less than 10%. The contact temperature is decreased to nearly 72 °C just by reduction of the friction coefficient by 40%, which is about 18 times higher than the 40% increase of thermal conductivity. The results indicate that the friction coefficient plays a more important role in the contact temperature than the thermal conductivity.     

The effect of sliding time and speed on the wear of composite materials

The friction and wear properties of an Al 201 alloy and a unidirectionally oriented graphite fiber-aluminum matrix composite (T50-Al 201) were investigated. The experiments were conducted on a pin-on-disc type friction machine. The diameter of the pin was 0.22 cm and the load 4.46 N. The sliding velocity varied between 0.17 and 0.43 m s^?1. The disc counterface was of commercially pure iron. It has been found that the friction coefficient μ and the wear rate W_L of the composite material decrease as the sliding time is increased until a steady state value is reached. The steady state wear rate is proportional to the reciprocal of the sliding speed in accord with a recently proposed model. Scanning electron microscopy and Auger electron spectroscopy observations indicate that the high initial values of μ and W_L are due to a high degree of matrix adhesion to the counterface accompanied by fiber breaking and transfer. The low steady state values of μ and W_L are due to the formation of a film that impedes adhesion and confers some degree of self-lubrication. It is suggested that the observed variation of W_L with sliding speed is related to changes in the degree of subsurface damage as the velocity is varied.     

The effects of using different type of inlet vents on the thermal characteristics of the automobile cabin and the human body during cooling period

A three-dimensional (3-D) transient numerical analysis was performed inside an automobile cabin during cooling period. A three-dimensional vehicle cabin including glazing surfaces was modelled by using the real dimensions of a car. A virtual manikin with real dimensions and physiological shape was added to the model of the vehicle cabin, and it was assumed that the manikin surfaces were subjected to constant temperature. The virtual manikin was divided into 17 parts in standing posture to evaluate the local heat transfer characteristics of the human body during transient cooling period. We considered three different cases that the cooling capacity of the automobile cabin was same for all cases. Three-dimensional fluid flow, temperature distribution and heat transfer characteristics inside the automobile cabin were calculated with different type of inlet vents. Comparisons of the numerical results were presented and discussed.     

The friction characteristics of the journal bearing in a reciprocating compressor for refrigeration and air conditioning systems

The performance of a reciprocating compressor in refrigeration and air-conditioning systems is influenced by the lubrication characteristics of the critical sliding components. Thus, the lubrication characteristics between the crankshaft and journal bearing have to be researched in order to improve the design and performance of a reciprocating compressor. Therefore, in this study, to enhance the EER (energy efficiency ratio) to reduce power consumption, and to improve the reliability of a reciprocating compressor for refrigeration and air conditioning systems, theoretical analysis of the friction characteristics between the crankshaft and journal bearing in a reciprocating compressor is studied. The results demonstrate that frictional characteristics are significantly influenced by the clearance between the crankshaft and journal bearing and the viscosity of the lubricating oil.     

河池市草温、地温、气温的对比分析

利用广西河池市地面站2009年的观测资料,对不同季节天气情况下的草温、地温和气温的变化进行了综合性的对比分析。分析表明,草温最高温度平均值比地面最高温度平均值低5．7℃,对抑制“热岛效应”有一定作用。     

准高速机车制动盘三维温度场及热应力场分析

应用有限元方法对准高速机车制动盘制动过程中由于摩擦生热引起的热弹性问题进行研究.利用Pro/E软件建立制动盘三维实体模型,并将之导入ANSYS中建立制动盘的三维有限元模型.根据热力学理论建立传热数学模型以及耦合的热弹性本构模型.虚拟仿真过程中考虑热流密度和换热系数随时间变化的影响,得出随时间变化的温度场和应力场.仿真结果表明,制动盘在制动后20s最高温度达到121℃,在制动后10s最大应力达到210MPa.     

基于云平台的空调控制系统的设计与实现

近年来随着云技术的发展,基于云服务的远程控制系统越来越受到关注。搭建一个基于OpenStack的私有云服务器,采用ZMQ通信中间件、MongoDB非关系型数据库和红外传输等技术,设计了一种结构简单、性价比高、扩展灵活的"云+端"控制系统,从而实现对空调的远程控制,并应用云模型中的逆向云发生器使系统具有分析能力。该文详细描述了系统总体设计方案,详细说明其中的软硬件设计要点,阐明系统的应用特点和应用前景。