溶液调湿空调系统在电子厂房中的应用分析

以重庆某电子厂房生产车间为例,介绍了溶液调湿空调系统在电子厂房中的应用。该系统采用溶液调湿新风机组消除湿负荷,利用高温冷水机组处理室内显热负荷。详细介绍了这一空调系统形式的具体设计方案和设计要点,分析了该系统的经济性。实测结果表明溶液调湿空调系统应用于电子厂房可以满足生产工艺要求。     

调湿材料对室内湿环境影响的实验研究

利用3种调湿板材硅藻泥抹面板、纸面石膏板、玻镁板,搭建了模拟用的实验箱,进行了室内湿环境动态变化模拟实验,得到了在不同工况下应用调湿材料模拟小室内相对湿度变化的规律,相对于对比实验箱,结果表明调湿材料有一定的调湿效果,对室内相对湿度的控制能力依次是玻镁板、硅藻泥抹面板、纸面石膏板;分析了散湿源的面积、是否间歇通风换气、间歇湿源、调湿板的面积等实验条件对三种调湿板材的调湿效果影响的程度。     

医院影像科与核医学科机房空调设计方案分析

简单介绍了医院影像科与核医学科设备机房空调要求。结合南京市某医院工程实例,分析了溶液调湿新排风空调与恒温恒湿空调这两种方案的系统构成、空气处理过程、适用特性、初投资。利用华电源能耗模拟软件,对全年空调负荷、全年空调系统耗电量进行模拟计算,结果显示这两种方案都可以满足机房的温湿度要求,恒温恒湿空调方案初投资低14.4%,溶液调湿新排风空调方案年耗电量低17.3%。     

市区高压变电站房封闭式降温系统理论探讨

我国城市市区有很多室内变电站房,其在工作时产生的热量大需要通过通风系统来保证室内正常的工作温度。传统的变电站通风系统包括自然通风、机械通风等。自然通风降温能力低且不稳定;机械通风降温能力相对较大,但噪声污染严重;另外这种开放式通风系统室内易于积灰,进而引起电线跑电甚至机组烧毁最终造成市区大面积停电等事故。提出一种封闭降温系统,可阻断灰尘的侵入,对其可行性及与封闭式空调系统相比的经济性进行了分析。结果表明:经过合理的设计,该系统可满足夏季温度最高日达到国家要求的电抗室内温度不超过40℃的要求,并且该系统比空调系统更为节能。     

风口上置置换通风的实验研究

对风口上置置换通风系统进行实验研究,得出此种通风方式下送风口的速度分布,室内的温度分布,O.1m处的风速等实验数据.通过分析实验数据得出,风口上置置换通风在满足室内热舒适性的前提下,能够提高房间的负荷承担能力,与混合通风相比能够得出较高的通风效率;另外,阶梯形的风口较普通的送风口能较少的卷吸上区品质差的空气,能更好地满足上置置换通风的风口特性要求.     

温度控制与污染物浓度控制相独立的通风空调系统

为解决传统通风空调系统温度控制与污染物浓度控制需求风量不匹配的问题,提出了一种温度控制与污染物浓度控制相独立的通风空调系统结构和控制方法。通过室内负荷计算及PM2.5浓度计算,对比分析了北京、上海、深圳地区在保证室内温湿度需求时典型办公室内的PM2.5浓度水平。结果表明,该通风空调系统可以同时满足室内温度和PM2.5浓度的控制要求,尤其在室外气候温和且大气污染较重时期对室内环境的保障效果更为明显。以北京地区2018年为例计算,在室内温度相同情况下,采用该通风空调系统室内PM2.5浓度全面达标,而采用传统通风空调系统则有10.3%的时间超标。     

严寒地区住宅冬季置换通风测试分析

为研究严寒地区住宅冬季有组织通风效果,对哈尔滨市某住宅小区的通风系统进行了现场实测。通过测试数据分析结果表明:采用置换通风方式时,室内空气温度能够满足采暖热舒适度要求;室内空气品质达到标准规定;该通风系统的通风效率较高,能够有效地排除室内污染物,同时可减少新风量需求,降低空气的处理、输送能耗。     

溶液调湿空调技术在酒店空调系统的应用

本文对溶液调湿空调技术在酒店空调系统中的应用进行了研究,着重介绍了酒店建筑空调系统特点及溶液调湿空调技术的原理、形式和优势,最后通过工程实例对热泵式溶液调湿新风机组(HVF)加VRV多联机组成的空调系统的经济性及节能减排效益进行具体分析。     

深圳国际会展中心空调及通风设计

介绍了该项目的制冷站规划、空调水系统及展厅气流组织设计等。结合运营需求和空调系统的特点,在国际报告厅、日常使用场所和数据中心分别设置了溶液调湿空调、独立空调和恒温恒湿空调。通过设置多功能通风系统改善了布展和撤展工作环境。     

舒适节能策略在南京南站中的应用

本文通过对南京南站主站房的负荷特点及室内空调通风方案的设计分析,采用模拟软件进行辅助设计,并对自然通风系统和空调通风系统进行设计优化。提出既满足节能又满足室内舒适性的合理的设计方案,大大的节约了空调能耗,对节能减排有重大意义。     

Performance analysis of liquid desiccant based air-conditioning system under variable fresh air ratios

In conventional air-conditioning system, fresh air volume is always restricted to save energy, which sacrifices indoor air quality (IAQ) to some extent. However, removing the latent load of air by liquid desiccant rather than by cooling is an alternative way of reducing energy consumption. Therefore, IAQ can be improved by increasing the volume of fresh air introduced into an air-conditioning system. In this paper, a liquid desiccant based air-conditioning system is studied, with the system performance under various fresh air ratios analyzed using simulation tests. In addition, the proposed system and a conventional system are compared. In the proposed system, with the increase in fresh air ratio, the heating load for solution regeneration rises, the dehumidification efficiency increases and the regeneration efficiency drops. The coefficient of performance (COP) of the liquid desiccant based system decreases sharply when the fresh air ratio exceeds 60%. The results also show that the proposed system can save power notably. The maximum power saving ratio is 58.9% when the fresh air ratio is 20%; however, the ratio drops when the fresh air ratio increases. These findings will be beneficial in the selection of fresh air ventilation strategies for liquid desiccant based air-conditioning systems.     

溶液除湿空调在档案库房中的应用

本文首先对档案库房所需要的环境进行了分析,指出档案库房除了要满足基本的温度和湿度要求外,还必须有一定的洁净度、空气酸度和霉菌量的要求。而后剖析了常规冷凝除湿空气处理机组在档案库房空调应用中的弊端,研究提出了适应于档案库房的基于温、湿度独立控制技术的溶液除湿空气处理技术。最后通过对常规空调与溶液除湿空调的能耗分析,得出溶液除湿空调与常规空调相比可显著节能的结论。     

Performance of combined displacement ventilation and cooled ceiling liquid desiccant membrane system in Beirut climate

The performance of the chilled ceiling (CC) displacement ventilation (DV) systems is constrained by latent load removal capacity and cost of supply air dehumidification to prevent condensation on the ceiling. In this study, a liquid desiccant dehumidification membrane cycle (LDMC) is mathematically modelled to replace the CC and remove directly latent and sensible load from indoor space through the membrane. The desiccant system is coupled with the DV system. An optimized operational strategy is adopted while allowing ceiling temperature to drop to lower values than conventional CC/DV. The optimized LDMC-C/DV system was implemented in an office space in Beirut climate. It was found that decreasing the membrane liquid desiccant temperature resulted in a significant decrease in the total cooling energy of the system, while increasing the solar heating energy of the desiccant regeneration. At optimal set points, a decrease of 49% in energy consumption was observed compared to the conventional CC/DV system.     

Desiccant wheels as gas-phase absorption (GPA) air cleaners: evaluation by PTR-MS and sensory assessment

Two experiments were conducted to investigate the use of the co-sorption effect of a desiccant wheel for improving indoor air quality. One experiment was conducted in a climate chamber to investigate the co-sorption effect of a desiccant wheel on the chemical removal of indoor air pollutants; another experiment was conducted in an office room to investigate the resulting effect on perceived air quality. A dehumidifier with a silica-gel desiccant wheel was installed in the ventilation system of the test chamber and office room to treat the recirculation airflow. Human subjects, flooring materials and four pure chemicals (formaldehyde, ethanol, toluene and 1,2-dichloroethane) were used as air pollution sources. Proton-Transfer-Reaction--Mass Spectrometry (PTR-MS) and sensory subjects were used to characterize the effectiveness of chemical and sensory pollution removal of the desiccant wheel. The experiments revealed that all the measured VOCs were removed effectively by the desiccant wheel with an average efficiency of 94% or higher; more than 80% of the sensory pollution load was removed and the percentage dissatisfied with the air quality decreased from 70% to 20%. These results indicate that incorporating a regenerative desiccant wheel in a ventilation system is an efficient way of removing indoor VOCs. PRACTICAL IMPLICATIONS: This study may lead to the development of new air cleaners and validates a new concept for the design of ventilation systems that can improve indoor air quality and reduce energy consumption.     

Optimization of a liquid desiccant based dedicated outdoor air-chilled ceiling system serving multi-zone spaces

A liquid desiccant based dedicated outdoor air-chilled ceiling (DOAS-CC) system is proposed to serve a multi-zone space. The outdoor airflow rate and the supply air humidity ratio are two crucial variables in such a system, which significantly influence indoor thermal comfort, indoor air quality and energy consumption. Two strategies are presented to optimize these two variables in the study. They are the demand-controlled ventilation (DCV) strategy and the supply air humidity ratio set-point reset strategy. To evaluate the performances of these two strategies, a basic control strategy, i.e., the strategy adopting constant ventilation flow rate and constant supply air humidity ratio, is selected as the benchmark. Performances of the two strategies in terms of indoor air temperature, relative humidity and CO₂ concentration as well as energy consumption are analyzed using simulation tests. The results show that the supply air humidity ratio set-point reset strategy is effective for the indoor air humidity control. It can save about 19.4% of total energy consumption during the whole year. The DCV-based ventilation strategy can further reduce about 10.0% of energy consumption.     

利用冷凝热再生的复合除湿空调除湿潜力分析

简要描述了利用冷凝热再生的复合除湿空调系统形式及其节能性特点;在热力学第一定律和热力学第二定律的基础上,分别以冷凝器和除湿转轮为控制体,建立了复合除湿空调的系统热力学模型,并给出模型求解框图,从而可以求得复合除湿空调系统的除湿量;最后,计算了在不同转轮效率和室内单位面积显热负荷下的系统单位面积除湿量,并讨论了新风量大小对结果的影响;结果表明,在现有转轮效率和常见单位面积负荷指标下,转轮的除湿量小于新风湿负荷（1次/h）,而降低新风量后（0.5次/h）,当转轮效率较高和室内显热负荷较大时,转轮能够承担新风湿负荷。     

Experimental study on dehumidifier and regenerator of liquid desiccant cooling air conditioning system

A new type of air conditioning system, the liquid desiccant evaporation cooling air conditioning system (LDCS) is introduced in this paper. Desiccant evaporation cooling technology is environmental friendly and can be used to condition the indoor environment of buildings. Unlike conventional air conditioning systems, the system can be driven by low-grade heat sources such as solar energy and industrial waste heat with temperatures between 60 and 80 °C. In this paper, a LDCS, as well as a packed tower for the regenerator and dehumidifier is described. The effects of heating source temperature, air temperature and humidity, desiccant solution temperature and desiccant solution concentration on the rates of dehumidification and regeneration are discussed. Based on the experimental results, mass transfer coefficients of the regeneration process were experimentally obtained. The results showed that the mean mass transfer coefficient of the packing regenerator was 4 g/(m² s). In the experiments of dehumidification, it was found that there was maximal tower efficiency with the suitable inlet humidity of the indoor air. The effective curves of heating temperature on the outlet parameters of the regenerator were obtained. The relationships of regeneration mass transfer coefficient as a function of heating temperature and desiccant concentration are introduced.     

New type of fresh air processor with liquid desiccant total heat recovery

A liquid desiccant total heat exchanger and small capacity refrigeration cycle combined fresh air processor is proposed here in this paper, in order to improve indoor air quality and decrease the energy consumption of the air-conditioning system. Operating principles of both the total heat recovery device and fresh air processor using liquid desiccant are presented in details. Experimental tests of the fresh air processor installed in a hospital show that energy efficiency ratio (EER) is around 6.3–7.3 in the summer experimental conditions and 4.7–5.0 in the winter experimental conditions. Hour-by-hour simulation, which is based on the climate data in Beijing, shows that the average EER is 5.3 and 4.3 in summer and winter period, respectively. Liquid desiccant has the potential to remove a number of pollutants, avoiding cross contamination. Furthermore, in summer fresh air is dehumidified by contacting liquid desiccant instead of 7 °C chilled water, which avoids wet surfaces in the air-conditioning system and much higher indoor air quality can be achieved.     

溶液全热回收装置与热泵系统结合的新风机组

提出了一种以溶液为媒介的全热回收装置和热泵系统相结合的新风处理机。安装于某医院的新风机性能测试结果表明：测试条件下，新风机夏季性能系数为6．3～7．3，冬季性能系数为4．7～5．0。新风机中吸湿溶液能去除空气中多种污染物，可避免新风和室内排风之间的交叉污染。     

Field performance measurements of a heat pump desiccant unit in dehumidification mode

The variable refrigerant volume (VRV) air conditioning system needs to be operated in conjunction with a ventilation system, because the VRV system cannot provide any fresh air. The common ventilation unit used with the VRV system is the heat recovery ventilation (HRV) unit. In this study, a new ventilation unit, a self-regenerating heat pump desiccant (HPD) unit, was introduced and the characteristics of the HPD unit was experimentally investigated over a wide range of operating conditions in a field performance test. In addition, the energy saving contribution of the HPD and HRV units to the VRV system was compared. It was found that the HPD unit maintained the target indoor humidity ratio of 10 g/kg throughout the cooling season resulting in a better indoor thermal comfort than the HRV unit. Besides, it was found that the outdoor unit of the VRV system consumed 26.3% less energy for the operation in conjunction with the HPD unit as compared to the operation in conjunction with the HRV unit.