冷却塔免费供冷在不同地区商业建筑内区适用及经济性分析

介绍了冷却塔免费供冷技术的分类及原理。以间接供冷为例,分析了风机盘管、板式换热器、冷却塔选型要点。以大型商业建筑内区中服务于零售与餐饮两种业态的冷却塔免费供冷为例,分析了新风系统及冷却塔供冷所需承担的室内负荷比例;讨论了在我国不同气候环境下、不同地区冬季,使用冷却塔免费供冷技术时所需的室外湿球温度、供冷切换温度、换热温差、供冷时长及规律。以某项目为例,计算分析主机供冷与冷却塔免费供冷在不同地区的运行费用及投资回收期,为不同气候环境下冷却塔免费供冷提供设计依据和参考。     

闭式冷却塔冬季运行性能研究

以带填料的闭式冷却塔为分析对象,基于冷却塔热质交换原理及能量平衡方程,结合其热质交换数学模型以及各项冷却塔传热性能评价指标,以冷却塔额定工况的换热能力为比较基准,重点分析了冬季室外气象参数(干球温度、湿球温度)对冷却塔热湿交换性能的影响。在此基础上,进一步分析了闭式冷却塔在上海地区冬季运行的具体性能。     

公共建筑开式冷却塔过渡季节供冷适宜条件分析

为评价冷却塔在过渡季节或冬季非额定工况条件下的热湿交换性能,基于冷却塔的基本热湿交换原理,以开式横流湿式冷却塔为研究对象,重点分析了室外空气湿球温度ts1、冷却塔进口水温tw1及水气比μ等因素变化对冷却塔全年运行热湿交换性能以及冷却塔冷却能力偏离额定工况的影响规律;并分析讨论了北京、南京、西安、重庆地区冷却塔过渡季节(冬季)供冷运行的适宜条件。     

地铁排热风井对地铁车站冷却塔运行影响的模拟分析

以上海地铁国权路车站冷却塔为例,对排热风井位于冷却塔不同方位、不同距离进行了数值模拟,得出地铁排热风井对冷却塔运行环境的影响,并进一步分析对机组能耗的影响.为地铁车站环控设计时排热风井和冷却塔的合理布置提供建议.     

烟台某办公楼冷却塔供冷系统设计与分析

以烟台某办公大楼为例,详细介绍了冷却塔供冷系统设计。重点分析了内区房间室温的选择、最高冷水温度的计算、负荷侧和冷源侧系统设备配置的比较、冷却塔运行时间的计算,以及7个可行性方案的节能性与经济性比较。合理选择了冷却塔供冷系统的切换温度、供冷时间、运行水温,以充分利用冷却塔的冷却功能制冷。     

某商场冷却塔供冷系统设计

本文以某商场空调工程为实例,介绍了冷却塔供冷的原理,分析了冷却塔热工特性曲线,冷却水供水温度、温差取值,水泵选型,冷却塔供冷和冷水机组供冷工况转换点等问题。     

自然通风式双曲线冷却塔结构设计

本文以臬环保热电项目冷却塔为例,简要介绍了自然通风式双曲线冷却塔的结构、技术参数、基础做法、塔体各组成部分,构件的结构设计,并对冷却塔设计中起主要控制作用的荷载进行了探讨。     

基于土壤热平衡的混合式地源热泵系统控制方案研究

基于TRNSYS软件平台建立了以冷却塔为辅助散热装置的混合式地源热泵系统模型,以长沙地区某办公建筑为例,模拟了系统运行20年的地埋管附近土壤平均温度及机组性能。研究了循环水温控制、循环水与环境温差控制和冷却塔运行时间控制3种冷却塔启停控制方案对热泵系统运行能耗和土壤热平衡的影响,对各方案下的运行参数进行了优化。结果表明,使用带冷却塔的混合式地源热泵系统运行能耗低,并且能够有效消除土壤热量累计效应;采用以循环水温为控制信号的方案时系统运行能耗更低、冷却塔运行时间更短。     

普通玻璃钢冷却塔改造为低噪声冷却塔

冷却塔广泛应用于石油、化工、纺织、电力、宾馆、影剧院、医院及居民点等巨量用水的地方,以减少能耗和重复利用水资源。冷却塔除了其冷却水量、热工性能之外,噪声的高低也是主要指标之一。近年来,为适应环境保护、劳动保护的需要,不少科研设计单位及制造厂设计生产了一些低噪声型冷却塔。但是,用量最大的还是普通型(又称标准型)玻璃钢冷却塔。这种冷却塔制造方便,价格低廉,使用量大,分布面广。很多安装了普通型玻璃钢冷却塔的单位,因其噪声较高,污染环境,所以迫切希望在花钱不多的情况下,将其改造为低噪声冷却塔。     

空调系统节能优化运行与改造案例研究(4):冷却塔

冷却塔是集中空调系统的重要组成部分,开式逆流冷却塔在大型公共建筑空调系统中应用广泛,但实际运行过程中却普遍存在效率偏低的问题.以制冷机和冷却塔构成的系统为研究目标,提出了以制冷机节能为核心的优化思路.建立了半经验理论模型进行模拟计算,并在实际建筑中进行了改造测试,总结分析得到了冷却塔风机联合变频调节和高低风速调节的控制方法.     

Study on indoor thermal environment of office space controlled by cooling panel system using field measurement and the numerical simulation

The purpose of this study was to analyze the performance of a cooling panel system installed in the vertical plane with condensation (hereinafter a cooling panel system) using field measurement and coupled simulation of convection and radiation (CFD). Unlike an all-air cooling system, the cooling panel system could remove the cooling load by convection and radiation. Since the surface temperature of the cooling panel analyzed in this study can be controlled under the dew point, this system is expected to be energy-saving and dehumidifying. In the first step of this study, the indoor thermal environment of the office space, which is air-conditioned by a cooling panel system, was analyzed by field measurement and CFD. By comparing both results, the expected precision of CFD for an indoor space with a cooling panel was examined and the CFD method verified from a practical point of view. In the next step, the thermal environment of the model office space, which is cooled by three types of HVAC system (cooling panel system, all-air cooling system, and hybrid air cooling system composed of cooling panel and natural ventilation), was analyzed using CFD. Installing a human model in the office, the characteristics of heat transportation from the human model were also analyzed. The analysis deals with only sensible heat in this study. The operative temperature in the cooling panel system was lower than that in the all-air cooling system when each of the sensible cooling loads of all types of HVAC system was the same. In conclusion, the cooling panel system was found to be very energy-efficient.     

空调设计冷负荷计算专家系统的开发

空调设计冷负荷计算具有“不确定性”和“预测性”的特点，为了解决目前空调工程设计中冷负荷设计值普遍偏大的弊病，将专家系统技术与空调冷负荷指标估算法结合起来，利用人工神经网络技术建立了一个空调设计冷负荷计算专家系统，该系统计算结果准确，特别适于经验不足的设计人员使用。     

Effect of fa?ade systems on the performance of cooling ceilings: In situ measurements

This article presents an innovative fa?ade system designed to increase the thermal comfort inside an office room and to enhance the cooling capacity of the suspended cooling ceiling. A series of measurements is conducted in an existing office building with different fa?ade systems (i.e., a combination of glazing and shading). An innovative fa?ade system is developed based on this intensive set of measurements. The new system enhances the thermal comfort and cooling capacity of the suspended cooling ceiling. The main usage of the new system is the refurbishment and improvement of existing fa?ade systems.     

江水源集中供冷供热系统控制策略初探

江水源集中供冷供热控制系统采用基于负荷预测优化控制的控制策略,通过对取水站、能源站、供冷供热管网及末端区域用户供冷系统的分析,提出了集中供冷供热控制系统的整体解决方案。     

夏季湿热地区置换通风和冷却顶板复合系统节能潜力研究

根据上海一办公楼置换通风和冷却顶板复合系统的设计及运行特点,应用EnergyPlus软件模拟了采用转轮除湿方式的复合系统的供冷季能耗,并分别模拟了采用冷却除湿方式的复合系统、带热回收装置的混合通风系统和置换通风系统的供冷季能耗以进行对比。结果表明,在湿热地区采用转轮除湿方式可比冷却除湿方式节约制冷机冷量,空调季总能源费用比混合通风系统节约30%左右。     

虹桥交通枢纽T2航站楼供冷站运行分析

简要介绍了该供冷站的系统构成.该系统采用水蓄冷及末端直接供冷技术,并配置了先进的自动控制、合理的控制策略和运行管理方式,使系统运行稳定、可靠,获得了较好的经济效益.     

Innovative low-energy evaporative cooling system for buildings: study of the porous evaporator wall

To face the current increase of building cooling demand and the concerns related to climate changes, an energy-efficient evaporative cooling system using porous material has been developed. This article presents the innovative cooling system and a detailed hygrothermal analysis of its main element: the porous evaporator. A mathematical model and an experimental set-up are presented, which enable to determine the suitable material properties for the evaporator and its impact on the overall cooling system performance, focusing on the optimal use of both energy and water. A good agreement is observed between numerical and experimental results, and the evaporative cooling power is estimated from 12 to 72?W/m² of evaporator wall, depending on the evaporator characteristics. A parametric analysis is conducted to select the best material for the evaporative cooling system. An intrinsic permeability of the material of 4?×?10^?17?m² is recommended for this new cooling system.     

A two-stage system of nocturnal radiative and indirect evaporative cooling for conditions in Tehran

In this paper, the results of an investigation on a two-stage cooling system have been studied. This system consists of a nocturnal radiative unit, a cooling coil, and an indirect evaporative cooler. During the night in summer, requisite chilled water for a cooling coil unit is provided by nocturnal radiative cooling and is stored in a storage tank. During the next day, the water in the tank provides chilled water for the cooling coil unit and hot outdoor air passes through two-stages: the cooling coil unit and an indirect evaporative cooler. Three sources provide secondary air for the indirect evaporative cooler. The sources are outdoor air, the air leaving from the cooling coil, and the air leaving from the indirect stage (regenerative). The investigation has been conducted in weather conditions in the city Tehran. The results obtained demonstrate that the first stage of the system increases the effectiveness of the indirect evaporative cooler. Also, the regenerative model provides the best comfort conditions. Therefore, this environmentally friendly and energy-efficient system can be considered as an alternative to the mechanical vapor compression systems.     

热电冷三联供供冷方式的分析与评价

依据热力学第二定律的(火用)分析方法,从能量利用的全过程出发,考虑输送能耗的影响,利用能源(火用)效率代替设备的能量利用效率对热电冷三联供的集中供冷和常规的电供冷方式进行了比较,从而得出了更客观、合理的结论,为合理采用热电冷三联供的集中供冷方式提供了判断依据。     

建筑环境设计模拟分析软件DeST第9讲冷热源与水系统模拟分析(下)

冷热源系统是整个集中空调系统的核心,它决定了系统能否保障用户的冷热需求,是投资的主要部分,也是能源消耗的主要部分。同时冷热源产生的冷热量主要依靠水系统输配到各末端用户中去。因此冷热源与水系统的联合优化设计是整个空调系统设计过程中至关重要的环节。综述了目前冷热源与水系统联合模拟的现状,详细阐述了DeST模拟软件中冷源和水系统模拟所采用的的模型与模拟方法。通过介绍一个设计实例,指出了冷热源与水系统全工况模拟的应用范围和实际意义。