高温气冷堆蒸汽发生器舱室混凝土温度场分析

采用ABAQUS6.7有限元分析软件,对高温气冷堆蒸汽发生器舱室混凝土在正常工况和设备冷却水系统停止供水事故工况下的温度场进行了计算。结果表明,在正常工况下,蒸汽发生器舱室混凝土的最高温度低于规定的限值;在设备冷却水系统停止对屏蔽冷却水系统供水事故工况下,7天内混凝土最高温度低于100℃,屏蔽冷却水系统能够保证对蒸汽发生器舱室的冷却。     

金川二矿机械化盘区充填采矿方法优化及应用

随着开采深度的增大,金川镍矿的开采环境越来越复杂,从而导致机型化盘区充填采矿法难于高效实施.针对金川二矿区开采技术条件,开展了机械化盘区开采方法的革新与应用研究,在大面积连续开采方法、回采进路及断面设计、盘区充填砂浆滤水工艺、盘区通风系统及采掘工程支护技术等方面进行了改进和优化.应用证明,这些改进的技术显著提高了金川二矿区的生产能力和经济效益,也为国内外深部复杂难采矿山的开采提供了宝贵经验.     

等离子体显示器自适应低功耗寻址方法

摘要为降低等离子体显示器(PDP)的寻址功耗,在分析了AERCs,no-AERCs,以及IPS等寻址方法的原理和特点的基础上,提出了一种自适应低功耗寻址方法及其实现电路——自适应寻址能量恢复电路(AAERCs),同时也给出了寻址数据变化率的检测方法。AAERCs首先检测PDP各子场寻址数据的变化率,然后根据不同寻址方法中寻址功耗和寻址数据变化率的关系,计算出相应的寻址功耗,根据计算结果,自适应改变PDP的扫描时序和对应的寻址数据,使AAERCs始终工作在寻址功耗最低的模式下。50英寸WXGA双扫PDP的实验结果表明:对于任何图像,AAERCs的寻址功耗均低于现有的任何一种寻址方法,典型图案下,寻址功耗最大可节省81W。     

On the influence of psychrometric ambient conditions on cooling tower drift deposition

Water drift emitted from cooling towers is objectionable for several reasons, mainly due to human health hazards. A numerical model to study the influence of psychrometric ambient conditions on cooling tower drift deposition was developed as a tool to evaluate liquid droplet dispersion and risk area. Both experimental plume performance and drift deposition were employed to validate the numerical results. This study shows the influence of variables like ambient dry bulb temperature, ambient absolute humidity and droplet exit temperature from cooling tower on the drift evaporation (and therefore deposition) and on the zone affected by the cooling tower. The strongest effect detected corresponds to the ambient dry bulb temperature. When a higher ambient temperature was present, deposition was lower (evaporation was therefore higher) and the zone affected by the cooling tower was smaller. The influence of the other two variables included in the study was weaker than the dry bulb ambient temperature. A high level of ambient absolute humidity increased drift deposition and also the size of the zone affected by the cooling tower. Finally, a high level of droplet exit temperature decreased deposition and increased the zone affected by the cooling tower.     

A novel approach to degree-hour calculation: Indoor and outdoor reference temperature based degree-hour calculation

This paper presents a novel approach to temperature probability density distribution and function. Probability density functions and frequency are successfully used in wind speed and solar energy analyses in literature. This study applies these data to temperature data analysis. The present model is developed using the indoor and outdoor temperature as a parameter. Outdoor temperature distribution is crucial for the calculation of monthly and total degree-hour. In this paper, using past weather data, the outdoor temperature probability density functions are modeled for four cities in different regions in Turkey via a new computer program. The main advantage of this approach is to allow us to determine heating and cooling loads with respect to different indoor and outdoor temperatures.     

Experimental study of gas engine driven air to water heat pump in cooling mode

Nowadays a sustainable development for more efficient use of energy and protection of the environment is of increasing importance. Gas engine heat pumps represent one of the most practicable solutions which offer high energy efficiency and environmentally friendly for heating and cooling applications. In this paper, the performance characteristics of gas engine driven heat pump used in water cooling were investigated experimentally without engine heat recovery. The effects of several important factors (evaporator water inlet temperature, evaporator water volume flow rate, ambient air temperature, and engine speed) on the performance of gas engine driven heat pump were studied in a wide range of operating conditions. The results showed that primary energy ratio of the system increased by 22.5% as evaporator water inlet temperature increased from 13 °C to 24 °C. On the other hand, varying of engine speed from 1300 rpm to 1750 rpm led to decrease in system primary energy ratio by 13%. Maximum primary energy ratio has been estimated with a value of two over a wide range of operating conditions.     

A generalized window energy rating system for typical office buildings

Detailed computer simulation programs require lengthy inputs, and cannot directly provide an insight to relationship between the window energy performance and the key window design parameters. Hence, several window energy rating systems (WERS) for residential houses and small buildings have been developed in different countries. Many studies showed that utilization of daylight through elaborate design and operation of windows leads to significant energy savings in both cooling and lighting in office buildings. However, the current WERSs do not consider daylighting effect, while most of daylighting analyses do not take into account the influence of convective and infiltration heat gains. Therefore, a generalized WERS for typical office buildings has been presented, which takes all primary influence factors into account. The model includes embodied and operation energy uses and savings by a window to fully reflect interactions among the influence parameters. Reference locations selected for artificial lighting and glare control in the current common simulation practice may cause uncompromised conflicts, which could result in over- or under-estimated energy performance. Widely used computer programs, DOE2 and ADELINE, for hourly daylighting and cooling simulations have their own weaknesses, which may result in unrealistic or inaccurate results. An approach is also presented for taking the advantages of the both programs and avoiding their weaknesses. The model and approach have been applied to a typical office building of Hong Kong as an example to demonstrate how a WERS in a particular location can be established and how well the model can work. The energy effect of window properties, window-to-wall ratio (WWR), building orientation and lighting control strategies have been analyzed, and can be indicated by the localized WERS. An application example also demonstrates that the algebraic WERS derived from simulation results can be easily used for the optimal design of windows in buildings similar to the typical buildings.     

Experimental validation of the simulation module of the water-cooled variable refrigerant flow system under cooling operation

On the basis of EnergyPlus’s codes, the catalogue and performance parameters from some related companies, a special simulation module for variable refrigerant flow system with a water-cooled condenser (water-cooled VRF) was developed and embedded in the software of EnergyPlus, the building energy simulation program. To evaluate the energy performance of the system and the accuracy of the simulation module, the measurement of the water-cooled VRF is built in Dalian, China. After simulation and comparison, some conclusions can be drawn. The mean of the absolute value of the daily error in the 9 days is 11.3% for cooling capacity while the one for compressor power is 15.7%. At the same time, the accuracy of the power simulation strongly depends on the accuracy of the cooling capacity simulation.     

特厚板坯连铸机二冷区喷嘴选型与布置

 连铸的二次冷却是影响铸坯质量的重要因素之一,而喷嘴选型和布置对二次冷却均匀性尤为重要。针对厚度大于400mm的特厚板坯生产所具有浇铸速度低、角部温度低、横向温度不均匀、液芯长度偏长等特点,拟定了特厚板坯喷嘴选型及布置的设计要求准则,再基于喷嘴厂提供的喷嘴试验参数和设备设计特点,从喷嘴喷射角度、安装高度、喷嘴间距、布置方式等方面对特厚板坯喷嘴选型与布置进行了分析,并就弱化特厚板坯边部冷却、均匀化水流密度提出了策略。生产实践表明,特厚板坯外形尺寸良好,表面质量无缺陷、内部质量良好。     

快速定量装车液压系统冷却、加热装置解析

快速定量装车系统液压站液压油温过高或过低都会直接影响到液压站的正常运行,对装车的精确度和安全生产带来隐患。通过对液压系统的热力学计算,对液压站设置冷却和加热装置提供了理论依据,并从快速定量装车系统实际使用工况出发,设置液压冷却和加热装置回路,确保液压站安全稳定运行。