主动式冷梁空调系统适用性研究

主动式冷梁(Active chilled beam)作为辐射供冷末端的一种重要形式,具有节能、舒适等优势。本文首先根据主动式冷梁系统的工作原理,提出了3个反映其冷却性能、系统能效和结构特点的评价指标。在不同室外气象参数条件下,校核计算了主动式冷梁系统的适用范围,得出中国除部分高湿度临海地区需增加一次风系统表冷器排数外,绝大部分城市采用常规表冷器便可达到室内的负荷要求。而后,通过对3个评价指标的计算,进一步探讨了主动式冷梁系统在中国不同地区的适用效果,得出冷却性能和系统能效均按自西向东、自南向北的方向递增,而结构产生的性能优势变化趋势相反。由此可见,在中国北方地区,尤其是东北地区,采用主动式冷梁空调系统能效更高,优势更明显。     

主动式冷梁空调系统风系统调适实践

以实际项目为例,重点介绍了主动式冷梁空调系统风系统调适方法,包括冷梁末端系统风平衡调适及冷梁空调主送风系统平衡调适。并结合主动式冷梁空调系统特点及调适结果,针对性地提出了建议。     

主动式冷梁在空调系统中的设计与应用

论述了主动式冷梁应用在空调系统中的节能重要性。冷梁应用可以提高室内环境热舒适性,同时可降低空调运行能耗实现建筑节能。提出新风设计及防止结露的控制措施在该系统中尤为重要,并为该技术在绿色建筑中的应用提供设计参考。     

新风深度冷却除湿系统在洁净手术室中的适用性探讨

比较了新风深度冷却除湿系统与一次回风再热系统的空气热湿处理过程。以某手术室为例,计算分析了2种空气热湿处理方案的适用性。结果表明,由于存在新风处理临界点,洁净手术室采用新风深度冷却除湿系统的总负荷并不总是小于一次回风再热系统。     

溶液除湿空调新风机组冬季工况性能研究

提出了一种由溶液除湿新风机组和空气源热泵装置组合的新系统,利用MATLAB语言对该系统进行数值模拟计算和分析,结果表明:在西安地区冬季空调室外计算参数下,新风机组性能系数COP,TCOP和COPh分别为0.5,0.65和5.1。     

间接蒸发冷却与冷凝除湿新风系统性能分析

间接蒸发冷却与冷凝除湿新风系统是一种基于蒸发冷却技术提出的新风处理方式,用于减少建筑物内新风量需求较大时,新风处理过程中所需的能耗。本文选取热回收效率、火用利用效率和系统综合性能系数(COP)作为评价指标对组合系统进行实验分析,着重考察了外界环境温度变化对系统运行性能的影响,分析了该系统降温冷却性能和其适应性。系统COP随进口新风干球温度和含湿量的增大而增大。当回风量偏小时系统热回收效率及火用利用效率随新风干球温度和含湿量的增大而增大,较新风量和回风量相等时的变化趋势相反。     

医用空调新风独立除湿系统变工况运行控制特性研究

本文结合医院手术室空调系统特点对新风独立除湿系统进行建模,并通过VBA编写程序进行模拟计算,研究以普通冷水机组为冷源的新风独立除湿系统的可行性,以及不同的室外环境温湿度、室内设计温湿度、新风量及冷冻水供水温度对新风独立除湿系统的能耗、运行特性及控制的影响,并提出使得系统较节能且稳定地运行的控制策略。研究结果表明,适当地增加新风量会提高新风机器露点温度,有利于系统的安全运行;室内设计温湿度的高低不仅会影响系统的能耗,而且会影响到新风机器露点温度,从而影响系统的稳定性;合理匹配室内设计温湿度和新风量,就能保证系统的稳定运行。     

转轮除湿与冷却除湿相结合的复合式除湿工艺空调系统

介绍一个转轮除湿与冷却除湿相结合的复合式除湿工艺空调系统，分析比较氯化钙、乙二醇冷冻水载冷剂在同一温度之间及同一载冷剂在不同温度下的换热系数差异，分析该工艺空调系统不能正常运行的原因，并提出改进措施。     

双级除湿冷却式空调系统及其能耗分析

介绍了双级湿冷却式空高系统及笔者建立的数学模型。计算机模拟结果显示，其再生温度大大低于单级除湿冷却系统，使低品位热能的利用成为可能。能耗对比分析表明，双级系统所消耗的Ｙｏｎｇ也低于单级系统。     

辐射空调新风除湿系统设计计算

基于北京市一栋采用辐射空调系统的住宅,计算了辐射空调新风送风的含湿量,绘制了新风系统焓湿图。通过焓湿图确定了内冷式双冷源热回收新风机组用于室内除湿时的各状态点,根据各状态点的参数值总结了设计计算时应注意的事项,提出了进一步提高系统能效比的方法。     

蒸发冷却新风空调集成系统

分析了对蒸发冷却技术的一些误解，介绍了新风集成系统，单风道、双风道、三风道集成系统等几种方案，在此基础上提出一种借鉴了独立新风系统设计思想的蒸发冷却新风空调集成系统方案。     

冷却顶板空调系统中用新风承担湿负荷的分析

分析了冷却顶板空调系统中利用最小新风量去除室内湿负荷的可行性，以及单独用表冷器处理新风的不足和改进途径。     

Study on a novel thermally driven air conditioning system with desiccant dehumidification and regenerative evaporative cooling

Existing desiccant cooling systems reduce the temperature of process air either by adopting evaporative coolers or incorporating vapor compression systems. While the former is restricted by inaccurate control, the latter still consumes certain quantity of electric power. To solve this problem, a thermally driven air conditioning system, which combines the technologies of rotary desiccant dehumidification and regenerative evaporative cooling, has been proposed and investigated. In addition to dehumidification, the system is capable of producing chilled water, thereby realizing separate temperature and humidity control without increasing electrical load. To find out the characteristics of produced chilled water and evaluate the feasibility and energy saving potential of this novel system, a mathematical model has been developed. Case studies have been conducted under Air conditioning and Refrigeration Institute (ARI) summer, ARI humid and Shanghai summer conditions. It is found that the system can achieve a thermal COP higher than 1.0 and an electric COP about 8.0. The temperature of chilled water produced by the system is around 14–20 °C. This chilled water can be used with capillary tube mats for radiant cooling. It is suggested that the system can also be designed as a standalone chilled water plant. As a desiccant dehumidification-based chilled water producing technology, this would expand desiccant cooling to a boarder niche application. The effects of chilled water flow rate, air distribution ratio, inlet air conditions and regeneration temperature have been analyzed in detail. Reachable handling regions, which will be helpful to system design and optimization, have been obtained.     

蒸发冷却空调新风系统的全年应用研究

结合干热、严寒或寒冷地区全年气候特点及冬夏季建筑能耗特性,通过逐时新风能耗模拟计算,得到设置热回收装置的全年用蒸发冷却空调系统冬季新风节能量远大于夏季节能量,选用热回收装置时应重点关注冬季热回收效率,各类热回收装置中转轮热回收装置全年节能量最大,节能效果最好。基于此,深入分析了蒸发冷却空调系统冬夏季新风加湿需求、新风量变化范围和水系统管径选择,给出了全年用蒸发冷却空调机组冬季运行的防冻措施。     

A combined system of chilled ceiling,displacement ventilation and desiccant dehumidification

Different types of heating, ventilation, and air-conditioning (HVAC) systems consume different amounts of energy yet they deliver similar levels of acceptable indoor air quality (IAQ) and thermal comfort. It is desirable to provide buildings with an optimal HVAC system to create the best IAQ and thermal comfort with minimum energy consumption. In this paper, a combined system of chilled ceiling, displacement ventilation and desiccant dehumidification is designed and applied for space conditioning in a hot and humid climate. IAQ, thermal comfort, and energy saving potential of the combined system are estimated using a mathematical model of the system described in this paper. To confirm the feasibility of the combined system in a hot and humid climate, like China, and to evaluate the system performance, the mathematical model simulates an office building in Beijing and estimates IAQ, thermal comfort and energy consumption. We conclude that in comparison with a conventional all-air system the combined system saves 8.2% of total primary energy consumption in addition to achieving better IAQ and thermal comfort. Chilled ceiling, displacement ventilation and desiccant dehumidification respond consistently to cooling source demand and complement each other on indoor comfort and air quality. It is feasible to combine the three technologies for space conditioning of office building in a hot and humid climate.     

Impact of heat load location and strength on air flow pattern with a passive chilled beam system

A passive chilled beam is a source of natural convection, creating a flow of cold air directly into the occupied zone. Experiments were conducted in a mock-up of an office room to study the air velocities in the occupied spaces. In addition, velocity profiles are registered when underneath heat loads exist and the cool and warm air flows interact. Experimental laboratory study revealed that in the case of the underneath heat gains, even no upward plume was generated and the dummy only acted as a flow obstacle, having a significant effect on the velocity profile. Furthermore, in an actual occupied office environment, the thermal plumes and the supply air diffuser mixed effectively the whole air volume. The maximum air velocity measured was still below 0.25 m/s with the extremely high heat gain of 164 W/m². The results demonstrate that analysis methods were the interaction of convection flow and jet are not taken into account could not accurately describe air movement and draught risk in the occupied room space.     

Thermodynamic modeling of a novel air dehumidification system

A novel air dehumidification system is proposed. The proposed system incorporates a membrane-based total heat exchanger into a mechanical air dehumidification system, where the fresh air flows through the enthalpy exchanger, the evaporator and the condenser subsequently. Thermodynamic model for the performance estimation of the combined system is investigated. Processes of the fresh air and the refrigerant are studied. Two additional specific programs are devised to calculate the psychrometrics and the thermodynamic properties of the refrigerant R134a. Annual energy requirement is 4.15 × 10⁶ kJ per person, or 33% saving from a system without energy saving measures.     

独立新风系统(DOAS)研究(3):常规风机盘管独立新风系统

分析了以风机盘管机组为空调末端装置,以普通冷水机组为冷源的独立新风空调系统的特点。结合设计实例,介绍了该空调系统的设计方法。详细说明了如何实现风机盘管的干工况运行。     

主动式冷梁在绿色建筑中的设计与应用

介绍了主动式冷梁的运行原理及设计特点,分析了主动式冷梁空调系统在某绿色建筑中的设计方法,指出新风设计以及防止结露的控制措施在该系统中尤为重要。结合GB/T50378—2014《绿色建筑评价标准》分析了主动式冷梁技术在绿色建筑中的得分项,为该技术在绿色建筑中的应用提供设计参考。