志高中央空调产品推介

螺杆式地源热泵 压缩机运行寿命更持久 表冷器特殊设计更高效 能源再利用更环保 运行稳定提高经济性 12大安全保护功能 微电脑控制器的控制功能 多种冷热源、冷媒选择，可选配部分热回收功能     

地源热泵冬夏两季运行性能分析与实验研究

结合天津某小区一地源热泵工程,在分析单螺杆压缩机的输气系数及总效率对压缩机性能影响的基础上对其设计工况进行求解,发现机组运行性能夏季比冬季好;分析了冬、夏季典型运行日机组工作温度的变化情况及其对机组性能的影响以及冬、夏季性能比较,验证了理论计算的正确性,同时发现冬、夏两季土壤的吸、排热负荷差值比设计值大。     

地源热泵U型垂直埋管传热特性的研究

基于ANSYS软件并结合唐山地区气象资料和土壤特性,建立了该地区地源热泵U型埋管非稳态温度场的数学模型并进行了性能分析.不同工况和埋管间距周围温度场的模拟结果表明,该地区最佳埋管间距约为4 m,并确定了给定条件下的热作用半径及土壤特性与热平衡时间的关系.考虑到土壤年净负荷或机组运行多年后净负荷均不平衡,分别对地源热泵机组全年和多年运行对土壤温度的影响进行了模拟.本文为地源热泵设计和施工提供了基础资料.     

使用定频压缩机的空气源热泵热水机最大负荷工况的研究

介绍了使用定频压缩机的空气源热泵热水机不同类型使用不同标准最大负荷工况运行时的不同情况,分析了机组铭牌中最大输入功率的确定依据.     

往复压缩机变负荷工况阀片运动规律及气缸内状态仿真研究

为了更好地了解往复式压缩机在不同工况下阀片的运动规律以及气缸内压力、温度的变化情况,对压缩机气缸及阀片运动规律进行了模拟仿真研究。采用有限元分析手段建立了往复压缩机的三维流场模型,在变负荷工况下,运用Fluent软件模拟分析了压缩机气阀与气缸工作状态;在正常工况下,模拟了压缩机气阀的运动情况和气缸内的压力变化情况,并利用往复压缩机实验台进行了实验验证;在气量调节工况和不同的阀片顶开位移的工况下,针对压缩机进行了模拟,得到了不同工况下阀片运动规律、气缸内示功图及气缸内温度变化规律。研究结果表明:针对机组复杂运行状态可用计算机仿真研究进行深入模拟,获得贴近实际运行状态的数据,对分析压缩机运行状态,改进优化气量调节系统具有重要作用。     

海相沉积砂岩土壤源热泵供热性能的试验研究

根据海相沉积砂岩——设计了土壤源热泵热水系统.试验采用单因素法,在连续和间歇运行两种工况下研究不同热负荷下系统的运行情况及土壤换热能力(通过控制开启主机的数量和土壤换热井数量来改变热负荷大小);在主机停止工作后,让土壤换热器中的循环介质与大地进行充分换热,测试土壤换热器中循环介质的温度变化来判断埋管区土壤温度场的恢复能力,从而综合评价地源热泵热水系统的运行性能.     

气量调节工况下6M51往复压缩机曲轴有限元分析

针对大型压缩机的传动机构在引入气量调节装置后故障率上升的问题,对6M51型往复压缩机曲轴进行了动力学分析及有限元分析。首先,通过构建力学模型,在变工况条件下,分析了该往复压缩机组传动机构的受力情况;然后,在曲轴变工况运行过程中,结合有限元分析法对各级连杆轴颈的变形和强度特性进行了分析;最后,对往复压缩机曲轴的静强度及疲劳强度进行了校核。研究结果表明:该压缩机曲轴的强度安全可靠,可在变工况条件下安全稳定运行,但气量调节工况下的往复压缩机在20%～40%负荷下运行时变形及应力明显增大,疲劳系数减小幅度较大,将加速曲轴的恶化,易发生断裂导致压缩机整机故障,因此需尽量避免使该机组在20%～40%负荷以下长期运行;该研究结果可为同类压缩机曲轴的设计和变负荷工况运行提供参考。     

R22地源热泵机组单螺杆压缩机循环性能研究

针对天津市一实际地下耦合地源热泵示范工程，在对所采用的地源热泵机组中的单螺杆压缩机产品样本数据分析的基础上，具体拟合出了单螺杆压缩机运行的输气系数和绝热效率与压缩比之间的关系式，并与往复活塞式压缩机相比较，结果表明单螺杆压缩机可获得较高的输气系数；同时分析了不同工作温度对单螺杆压缩机循环性能的影响，所得结论为单螺杆热泵系统数值模拟和运行特性分析提供了基础数据。     

基于小头瓦润滑EHD模型的变工况运行往复压缩机连杆动力学分析

针对往复压缩机采用气量调节装置进行流量调节中往复压缩机出现小头瓦磨损的问题,本文基于小头瓦润滑EHD模型,研究了往复压缩机变工况运行时连杆动力学特性。根据小头瓦变工况运行时的油膜分布状态,揭示了机组在变工况运行过程中小头瓦易发生磨损的原因,分析了不同调节方法对小头瓦变负荷工况运行产生的影响。基于仿真数据,证明了部分行程顶开进气阀调节方法最有利于往复压缩机变负荷运行,为机组变工况运行选择最佳气量调节方法提供实际参考价值。     

地下耦合地源热泵机组冬季供热性能分析与实验研究

针对天津市一地下耦合地源热泵示范工程，对所采用的单螺杆式地源热泵机组各部件参数之间的相互关系和运行特征。建立了地源热泵运行特性分析模型，并对机组性能进行了数值模拟；同时，结合对该系统的冬季制热工况的实测实验数据，对地源热泵冬季典型运行工况进行了实验研究，并与模拟分析结果作对比。结果表明，模拟和实验结果在数值上和变化趋势上均有较高的吻合度。     

Sensitivity of μ of Friction Materials to Load and Speed under Dry Sliding and Water Lubricated Conditions

The tribological behavior of friction materials is complex under various operating conditions. The present article discusses the sensitivity of tribological behaviors of friction materials to load and speed under dry and water-lubricated conditions qualitatively and μ of values was also analyzed quantitatively based on regression analysis. The friction and wear behaviors of friction materials were evaluated on a ring-on-block-type test rig. It was observed that the material itself was the dominant factor in μ sensitivity of friction materials, followed by sliding speed. The influence of the interaction of load and speed was negligible under water-lubricated condition. The friction coefficient of the composite was less sensitive to operating parameters under water-lubricated condition.     

Acetal gear wear and performance prediction under unlubricated running condition

Tests have shown that the acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry. The gear surface will wear slowly with a low specific wear rate if the gear is loaded below the critical condition. The sudden increase in wear rate may be due to the gear operating temperature reaching the material melting point under the critical load condition. Gear surface temperature has been investigated in detail by studying three components: ambient, bulk and flash temperatures. Through extensive experimental investigations and modelling on gear surface temperature variations, a general relation has been built up between gear surface temperature and gear load capacity. A new design method for acetal gear has been proposed based on the link between polymer gear wear rate and its surface temperature. The method has been related to test results under different operating ambient temperature and gear geometries. Good agreements have been achieved between the proposed method predictions and experimental test results. The maximum torque the acetal gears can transmit is 9 Nm for both the driver and driven with a 2 mm module, 30 teeth and 17 mm face width. Copyright © 2006 John Wiley & Sons, Ltd.     

A new feature for monitoring the condition of gearboxes in non-stationary operating conditions

The paper introduces a new diagnostic feature, which can be used for monitoring the condition of planetary gearboxes in time-variable operating conditions. The novel approach (originally presented in W. Bartelmus, R. Zimroz, Vibration condition monitoring of planetary gearbox under varying external load, Mechanical Systems and Signal Processing 23 (2009) 246–257) exploits the fact that a planetary gearbox in bad condition is more susceptible (yielding) to load than the gearbox in good condition. The diagnostic method based on the new diagnostic feature is very simple: one needs to capture signals for different external load values and calculate a simple spectrum based feature versus operating conditions indicator (current or instantaneous rotation speed). In a certain range of operating conditions the diagnostic relation (i.e. the dependence between the spectral features and the operating conditions indicator) is linear. However, since a gearbox in bad condition is more susceptible to load than the gearbox in good condition the relation will be different for the two cases. Using a simple regression equation one can calculate the slope of the straight line, which expresses the new diagnostic feature. The method is very quick, technically simple, robust and intuitive. This approach has been used for diagnosing the very complex high-power planetary gearbox used in bucket wheel excavators.     

电动机超负荷运转在打包机液压系统中的应用

本文通过对化纤打包机液压系统中主压工况的分析,提出可根据"周期性变负载这一特殊工况下电机可瞬时超载"的特性来设计并选择主压电动机功率.并通过实验来进一步验证.同时针对化纤打包机主压系统应用实例,提出了相应的保护措施.对减小打包机装机功率、降低噪声、降低用户运行成本具有指导性意义.     

钢-钢摩擦副在不同润滑和接触形式下的高温减摩性能的研究

用多功能SRV试验机评价了在干摩擦和油润滑条件下,试验参数对钢-钢摩擦副在点接触和线接触形式下的高温减摩性能的影响。结果表明,在试验范围内,随着试验负荷的增大,钢-钢摩擦副在干摩擦条件下线接触摩擦因数和点接触摩擦因数呈逐渐下降的趋势,这种下降趋势在线接触时尤为明显;但在油润滑条件下,试验负荷的增大对钢-钢摩擦副之间的线接触和点接触摩擦因数的影响不显著。在干摩擦条件下,不论是在点接触还是线接触形式下,试验速度对钢-钢摩擦副之间的高温点接触和线接触摩擦因数的影响并不显著;但在油润滑条件下,试验速度对钢-钢摩擦副的高温线接触和点接触摩擦因数的影响都比较显著,特别是在较高的试验速度时影响更为明显。     

浦东国际机场空调系统变水温运行分析

根据空调负荷和离心式及吸收式冷水机组的特性，探讨了变水温节能运行的可行性。通过对表冷器性能的分析，得出了冷水温度和流量等因素与供冷量的关系。针对浦东国际机场的负荷特点和气象条件，提出了分阶段变水温运行的方案。     

Polymer gear surface thermal wear and its performance prediction

This paper will concentrate on acetal gear wear behaviour and its performance prediction based on the extensive investigations on the gear thermal mechanical contact both experimentally and numerically. It has been found from the tests that acetal gear wear rate will be increased dramatically when the load reaches a critical value for a specific geometry and running speed. The gear surface will wear slowly with a low specific wear rate if the gear is loaded below the critical one. The possible reason of the sudden increase in wear rate is due to the gear operating temperature reaching the material melting point under the critical load condition. Gear surface temperature has been then investigated in details through three components: ambient, bulk and flash temperatures. Through extensive experimental investigations and modelling on gear surface temperature variations, a general relation has been built up between gear surface temperature and gear load capacity. An approach for acetal gear transition torque prediction has been proposed and this method is based on the link between polymer gear wear rate and its surface temperature. The method has been related to test results under different operating speeds and gear geometries. Good agreements have been achieved between the proposed method predictions and experimental test results.     

含低负荷场景低碳多源协调调度

温室效应导致全球持续升温,巨大碳排放量导致地球已不堪重负,如何降低碳排放成为目前亟待解决的问题。当风电出力与火电机组最小出力之和大于负荷量,只能通过储能、储热装置或弃风来达到功率平衡,此时可定义为低负荷运行状态。在低负荷时段,负荷消纳风电难、储能成本运行高。首先,考虑火电机组深调对发电成本和碳排放量的影响,建立了火电机组分阶段出力模型,将碳交易机制引入系统的调度模型中,构建阶梯型碳交易成本的计算模型;其次,以碳排放量和发电成本最小为优化目标,综合考虑系统的各种约束条件,建立了基于多目标的含低负荷场景低碳多源协调调度模型;然后,采用改进萤火虫算法,得到最优调度方案;最后,以带10个风电场的系统为算例,采用3种不同对比实验证明,所提方法可有效降低碳排放量,提高了系统运行经济性。所提方法分析了风电并网渗透率对系统运行方式的影响,表明含低负荷场景低碳多源协调调度与风电并网渗透率密切相关。     

装载机半轴变均值、变幅值标准载荷谱制取方法

结合装载机分段作业特点,提出了装载机半轴变均值、变幅值标准载荷谱的制取原则与方法,解决了均值、幅值“归一化”问题,最终建立装载机半轴标准载荷谱。     

油气润滑最佳供油量研究

研究了不同的工况参数s与所需的润滑油供油量的关系,发现在不同工况参数s下都存在最佳的供油量.通过试验和分析,得到系统所需供油量与系统工况参数s之间的关系式,应用该公式可以预测轴承-主轴系统的最佳供油量.