不同制冷量空调器在住宅中应用的实测对比研究

通过实验测试对比了不同制冷量的定速房间空调器用于住宅卧室中时的室内温湿环境状况和空调器的耗电量情况。实验结果表明,当空调器容量过大时,空调器的除湿能力下降,室内相对湿度偏高,空调器耗电量大,实验日条件下,使用1.5 HP空调器时的室内相对湿度比使用1 HP空调器的室内相对湿度高5%,而1 HP空调器耗电量比1.5 HP空调器减少12.7%。     

机械泵驱动分离式热管应用于空调冷量回收

为了探究机械泵驱动分离式热管对空调系统冷量回收和除湿能力的影响,搭建了四组该热管系统进行实验,其循环工质为R134a。在入口空气干球温度28.5℃、相对湿度60%的条件下,当运行热管由0增加到4组时,系统的机器露点由11.7℃降到8.2℃,供风温度由11.7℃升到24.1℃,系统的除湿能力增加了29.5%。指数δ(热管系统回收的冷量与制冷机蒸发器的制冷量之比)达到66.0%。研究结果表明,机械泵驱动分离式热管可以显著提高空调系统除湿能力,降低系统能耗。     

The effect of heat-pipe air-handling coil on energy consumption in central air-conditioning system

A study was carried out to investigate the effect of heat-pipe air-handling coil on energy consumption in a central air-conditioning system with return air. Taking an office building as an example, the study shows that compared with conventional central air-conditioning system with return air, the heat-pipe air-conditioning system can save cooling and reheating energy. In the usual range of 22–26 °C indoor design temperature and 50% relative humidity, the RES (rate of energy saving) in this office building investigated is 23.5–25.7% for cooling load and 38.1–40.9% for total energy consumption. The RES of the heat-pipe air-conditioning system increases with the increase of indoor design temperature and the decrease of indoor relative humidity. The influence of indoor relative humidity on RES is much greater than the influence of the indoor design temperature. The study indicates that a central air-conditioning system can significantly reduce its energy consumption and improve both the indoor thermal comfort and air quality when a heat-pipe air-handling coil is employed in the air-conditioning process.     

蒸发冷却+干式风机盘管的空调系统探讨

本文在温湿度独立控制的原理基础之上，根据西北地区的气候特点，提出了将干式风机盘管与蒸发冷却相结合的半集中式空调系统。该系统解决了目前蒸发冷却空调系统中存在的风管尺寸大、难以分室控制等问题。最后，结合工程实例对该系统的设计过程进行了分析，指出了使用蒸发冷却＋干式风机盘管半集中式空调系统比直流式全新风系统节省能耗21．9％以上。     

热管在多联机卧式暗装室内机中节能应用探讨

以某品牌多联机三个型号卧式暗装室内机为例,将热管技术应用于多联机卧式暗装室内机,计算不同室内设计温度条件换热量,研究结果表明,与传统多联机室内机相比较,其冷量节能率可达20．94％～33．73％,同时在无需电加热或蒸汽动力设备的条件下提高室内送风温度,达到节约能源消耗的同时满足室内人体热舒适的要求。     

Analysis of indoor environmental conditions and heat pump energy supply systems in indoor swimming pools

For indoor swimming pools, a lot of energy is needed to control the indoor temperature, relative humidity and pool water temperature. Meanwhile, the indoor air contains a high specific enthalpy due to water evaporation. A new heat pump dehumidifier is studied to reduce energy consumption. The most significant feature of this system is that it can not only recover the latent heat from indoor moist air, but also absorb heat from outdoor air to heat the indoor air and pool water. First, indoor environmental conditions, including space parameters and pool temperature, are analyzed based on human thermal comfort and energy saving. Subsequently, the models of heat and moisture gain are built. After that, the construction and operating modes of the heat pump dehumidifier are described, and the system model is established based on polynomial equations model. In a case study, an indoor swimming pool with a heat pump dehumidifier in Shanghai is studied. When outdoor air specific enthalpy is higher than 18.6 kJ/kg, the requirement of pool water heating can be met only by the heat pump dehumidifier, thus, auxiliary pool heater will not to be put into use. At last, economic analysis between the heat pump dehumidifier and conventional dehumidifier is conducted.     

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.     

Application of a closed-loop oscillating heat pipe with check valves (CLOHP/CV) on performance enhancement in air conditioning system

The objective of this paper was to study the application and working fluid type of a closed-loop oscillating heat pipe with check valves on energy consumption in split type air conditioning system. In the experiment, the CLOHP/CV was fabricated from the copper tube with the diameter of 2.03 mm. In the usual range of 20-27 °C indoor design temperature and 50% relative humidity. R134a, R22 and R502 refrigerant was used as working fluid in the CLOHP/CV set for this study. In comparison of the type with a conventional air conditioning system and that with the CLOHP/CV air conditioning system, the results have shown that; the new cooling load had increased 3.6%, the latter gave the highest value of 14.9%, 17.6% for COP and EER, respectively. The highest value of heat flux was 5.19 kW/m² with R134a was used as the working fluid, at overall operating temperature. The results of this study are expected to guideline as they improve the performance of the air conditioning system in buildings, which reduce its energy consumption.     

对热舒适、空气感觉质量及能耗的模拟研究

室内空调设计温度和新风量对热舒适，室内空气质量及能耗量有重要影响，然而对它们之间相互关系进行研究的文献却较少。通过计算机模拟空调系统在7种室内设计温度和7种新风量条件下的运行情况，得到不同的设计条件组合对热舒适、人体感觉空气质量及建筑能耗量的影响。基于这项分析，提出了此办公建筑合理的室内设计温度和新风量取值。     

室内恒温泳池综合节能方案研究

基于广州某会所室内恒温泳池的温湿度设计参数,计算了该泳池全年制冷、除湿、泳池加热和采暖负荷动态需求。通过分析动态冷热负荷曲线提出冷凝热回收应作为泳池综合节能方案的基本出发点,进一步比较了泳池专用热泵系统与全热回收风冷热泵系统两种方案的运行特点和全年能耗特性,并建议采用小型热回收型热泵系统与普通风冷热泵的组合方案。     

新风负担室内全部湿负荷的手术室空调系统设计探讨

医院手术部空调系统怎样节能一直是行业关注的话题,由于采用湿度优先的控制方法,传统的一次回风空调系统存在"冷热抵消"的能源浪费现象。论文通过对新风集中处理一次回风空调系统能耗分析,结合新风机组风冷比的概念,提出了变新风量一次回风空调系统。新风采用两档风量,夏季及过渡季节采用高档风量,冬季采用低档风量,且新风机组担负室内全部湿负荷。     

夏热冬冷地区民用建筑除湿方式的适用性分析

本文对常见的几种空气除湿的原理进行了分析,针对夏热冬冷地区的建筑气候特点,比较了冷冻除湿、通风升温除湿、被动除湿、干式除湿和复合式除湿等各自的特点和适用场合。分析了该地区空气处理设备实现温湿度独立控制的必要性,强调了空调设备设计选型时不能只考虑设备显热冷负荷,说明了湿度控制对空气处理设备设计选型的要求,提出了独立新风系统集中除湿和室内空气湿度独立控制的重要途径,并从室内环境质量综合控制角度指出了民用建筑空气除湿技术和该地区空气湿度控制方式的发展趋势。     

Development and experimental validation of a high-temperature heat pump for heat recovery and building heating

The performance of a high-temperature heat pump unit using geothermal water for heat recovery in buildings is experimentally evaluated. The unit consists of a twin-screw refrigeration compressor, a condenser, an evaporator and an oil cooling system. The effect of the cooled oil temperature on the performance of the heat pump unit is experimentally investigated. Results show that the unit stably produces outlet hot water at a constant temperature of 85 °C and performs well in a wide range of high-temperature conditions with a high energy efficiency ratio. The results also indicate that the key to improving the performance of a high-temperature heat pump unit often depend on the selection of proper cooled oil temperature. The optimum cooled oil temperature is 50-65 °C when the condensing temperature is above 70 °C. At these temperatures, the oil cooling system can increase the energy efficiency ratio of the heat pump by 6.3%.     

夏热冬暖地区小城镇住宅建筑节能潜力的调研与评价

通过对福建省永定县凤城镇居住建筑围护结构、住宅能耗水平及室内温湿度的实地调研和测试,对比分析了夏热冬暖地区小城镇住宅单位面积能耗与全国非采暖城镇平均能耗的差异;并测评了其居住热舒适环境.在此基础上,结合当地实际情况提出以下3种研究方法探讨该地区小城镇的建筑节能潜力,即①现状建筑条件下未来(空调普及后)的建筑能耗;②仅采...     

Performance of temperature and humidity independent control air-conditioning system in an office building

The temperature and humidity independent control (THIC) system, which controls indoor temperature and moisture separately, may be an attractive alternative to existing conventional HVAC systems for its prominent improvement on the overall system performance and utilization of low grade energy resources. In order to verify the effectiveness of THIC system, a pilot project has been implemented in an office building in Shenzhen, China. In the system, liquid desiccant fresh air handling units driven by heat pumps are utilized to remove the entire latent load of outdoor air supplied for the whole building, and chilled water at the temperature of 17.5 °C from chiller is pumped and distributed into dry fan coil units and radiant panels to control indoor temperature. This paper presents the results of field test of the system, which shows that the system can provide a comfortable indoor environment even in very hot and humid weather. The COP of the entire THIC system can reach 4.0. According to the energy usage data recorded from the year 2009, the energy consumption of the THIC system in the tested office building was 32.2 kWh/(m² yr), which demonstrates magnificent energy-saving potential compared with the conventional air-conditioning system (around 49 kWh/(m² yr)).     

数据机房用分离式热管散热器运行特性分析

信息化水平的不断提高直接带来了数据中心耗电量的急剧增加。数据机房不同于一般的公共建筑,考虑到隔热、隔湿及洁净度的要求,即使在冬季也需供冷降温。而在满足散热需求的前提下,最大限度利用自然冷源则是降低空调能耗的最有效方法。但目前自然冷源的利用中常出现受环境影响大、节能效率低等问题,热管式散热器能将室内外空气完全隔绝,具有启动温差小、体积小、安装灵活等优点,在机房节能中有很大的应用潜力。以节能和良好的环境适应性为目标,对数据机房应用分离式热管的被动式散热方式进行了理论分析。以本学科工程领域现有技术为基础,理论分析了应用分离式热管的意义及优势,定义了分离式热管蒸发段及冷凝段的换热效率,建立了数据机房应用分离式热管散热系统的理论分析模型,以某名义排热量为30 kW的管翅式换热器为例,研究换热效率随风量的变化关系,得出分离式热管散热下可运行的最高允许室外温度、全年运行时间、功耗及全年节电量等关键参数。以某一30 kW冷负荷数据机房为模型进行CFD软件模拟,获得了采用分离式热管散热器的机房内部温度场分布,并与普通空调进行了比较。针对室外温度下降所引起的室内侧送风温度过低问题,提出减小室外侧风量的具体改进措施。利用理论模型设计分离式热管换热系统蒸发段和冷凝段,提出可根据热负荷及实际机房灵活配置,建设成本低,有效适应机房现有散热系统的方法。主要结论如下:(1)分离式热管散热器应用于数据机房散热,换热效率随着风量增加而减小,分离式热管散热器应用于数据机房散热,换热效率随着风量增加而减小,但可利用室外冷源的温度升高,可利用室外冷源的时间也随之增加,可根据换热器及所在地区设计最佳风量。(2)分离式热管散热下风量较大时,机柜进风温度比普通空调散热更为均匀,机房内热环境更好,可减少机房内局部热点。(3)若风量不变,分离式热管散热器蒸发段送风温度随室外温度降低,并有可能低于机房送风的标准温度。可通过减小室外侧风量使室内蒸发段出风温度满足数据机房送风温度,同时散热器的能效也可进一步提高。     

Model-based commissioning for filters in room air-conditioners

This paper proposes a model that can estimate filter resistance using estimated air-conditioner indoor unit air flow rate, which is tightly related to filter fouling conditions. Two sorts of value are used as inputs to estimate air flow rate. One is the power consumed by the fan in the indoor unit of a room air-conditioner and the other is the thermal performance of a room air-conditioner. For the room air-conditioners that the real-time indoor unit fan power consumption is available, fan power consumptions are used as inputs to estimate filter resistance. For the room air-conditioners that are equipped with refrigerant pressure and temperature sensors, this model estimates filter resistance using refrigerant pressure and temperature, air temperature or enthalpy difference between supply and indoor air. This model was validated using a really running multi-evaporator Gas-engine Heat Pump (GHP) system. The maximum and average difference between estimated and measured filter resistance are 12.72% and 5.89% when using the fan power consumption as inputs. When using the air-conditioner thermal performance data, the maximum and average estimation errors are 13.12% and 5.96%. The validation results show that this model is accurate enough for estimating filter resistance. Based on this model, the method for commissioning filters in air-conditioner is discussed. This method is useful for automatically estimating filter resistance and reminding users timely to clean or replace a filter to prevent wasting energy and to maintain desirable indoor environment.     

A comparative study of different control strategies for indoor air humidity

There has been a rising concern in controlling the high indoor humidity of hot and humid countries. When an air-conditioned space experiences only part of its design heat load, its humidity tends to rise as a result of the air-conditioning system trying to control the indoor temperature by reducing its cooling capacity. In this study, the part-load dehumidification performances of three temperature control strategies are compared, namely, chilled water flow control, bypass air control and the variable air volume control. Coil simulations are employed to study the part-load performance of these control strategies. The coil model has been validated with experimental data to within ±6.5%. The relative humidity of a space depends of factors such as design sensible heat factor of the space, temperature control strategy employed and load condition experienced by the space. Simulation results have indicated that chilled water control strategy results in the highest indoor humidity throughout the range of conditions studied while variable air volume system provides highly effective dehumidification performance of the cooling coil. Bypass air control appears to be a good option for adoption as it is able to provide an acceptable humidity over a wide range of load conditions without having to affect the air movement within the space.     

Field performance measurements of a heat pump desiccant unit in heating and humidification mode

In this study, a novel self-regenerating electric vapor compression heat pump desiccant (HPD) unit operated in the heating and humidification mode during the winter season is introduced. The HPD unit was installed in an office suite for the field test. The performance of the HPD unit and the provided indoor conditions were measured over a wide range of operating conditions. The target indoor humidity ratio was set to 4.4 g/kg, which is the minimum required indoor humidity ratio for a comfortable indoor environment indicated in the ASHRAE winter thermal comfort zone. The seasonal comparison revealed that even though 77.7% of all outdoor humidity ratio data was lower than 4.4 g/kg, 78.2% and 85.8% of all the indoor humidity ratio data of each room were found to be higher than 4.4 g/kg. In addition, due to the significant sensible capacity of the HPD unit, the indoor temperatures could be maintained within 20-25 °C. These results prove that the HPD unit not only properly humidifies the indoors without using any additional water source, like the conventional humidifier, but also helps to keep the indoor temperature at the desired temperature levels.     

北方既有居住建筑节能改造效果实测评价

选取唐山市某6层既有居住建筑,进行了围护结构及供热计量节能改造。实测了节能改造前后两个供暖期的耗热量、室内温度,调查了节能改造前后用户对室内温度、外窗气密性的主观评价及用户节能意识。节能改造前后的单位面积耗热量指标(折算成室内设计温度为18℃)分别为31.11、15.80W/m2。室内平均温度由20.09℃提高至22.91℃,外窗气密性有了很大改善,居民的节能意识有所提高。