叠置式太阳能加湿除湿海水淡化系统的稳态性能研究

介绍一种基于空气加湿除湿技术的太阳能海水淡化装置,装置中除湿腔叠置在加湿腔的上部,以此缩小装置的占地面积并利用热湿空气自然上升的浮力,形成一种新结构。详细说明装置的结构和运行原理,并研究控制海水运行温度、流量、循环空气流率等参数对装置产水性能的影响。实验结果表明,装置产水量随进水流量和运行温度增加而增加,当温度为90℃时,进水流量为420 kg/h,装置的最大产水量达到10.38 kg/h,装置性能系数GOR最大为1.33。系统在类似条件下的理论产水率达到约15.6 kg/h,性能系数达到1.90。对生化小球和加湿帘2种填料及不同填料厚度的产水性能进行测试,结果表明填料的选择,要结合装置体积和传质效率来综合考虑。     

多级鼓泡式加湿除湿型太阳能海水淡化装置研究

提出一种多级鼓泡式加湿除湿型海水淡化装置。该装置主要由多曲面太阳能聚光系统、加湿层和除湿层以及相应的泵和管路组成。经聚光器加热后的高温空气在风机驱动下分别进入加湿层和除湿层,热风穿过各级筛板及筛孔,产生气泡,增大了空气与水的接触面积,强化了传热传质过程。在不同天气下对装置进行实验研究,结果表明：在晴朗天气下,装置的太阳能利用率最高可达0.41,淡化装置效率最大可达1.23,最大产水速率为3.66 kg/h,全天产水量为17.08 kg;在非晴朗天气下,装置产水量为12.43 kg。     

太阳能驱动的膜式加热加湿系统性能实验研究

中空纤维膜加湿系统能从根本上解决空气加湿过程中气液夹带的问题。通过搭建太阳能驱动的中空纤维膜加热加湿系统试验台并在冬季进行实验测试,分析出太阳能辐射量、空气体积流量和热水体积流量对系统加热加湿性能的影响。研究发现提高太阳能辐射量和空气体积流量对系统的加湿能力和热性能系数均有积极影响,而前者的影响更为显著。为了获得最好的系统性能,选择40℃(对应太阳能辐射量为329 W/m²)和100 L/h作为最佳热水条件,空气体积流量为100 m³/h。在此条件下,出口空气的含湿量为22.4 g/kg,约为环境空气的4倍。空气温度为30.5℃,热性能系数COP可达2.40,太阳能利用率为45%。由于膜加湿器的热质交换能力有限,过度提高热水温度反而降低太阳能利用率。为了在含湿量低的环境空气下提供较好的性能,采用低的空气体积流量,有助于提高出风的含湿量和空气温度。     

湿燃气透平叶片热流固耦合换热特性的数值研究

为评估湿空气透平循环中湿燃气对透平叶片燃气侧换热特性的影响,以及湿空气对透平叶片冷却效果的影响,以C3X叶片为例,采用热流固耦合的数值计算方法,研究了湿燃气含湿量对透平叶片表面温度和传热系数的影响,对比分析了干空气与湿空气冷却效果的差异.同时在研究范围内给出了透平叶片燃气侧传热系数的无量纲关系式,为湿化燃气轮机透平叶片的优化和冷却结构设计提供参考.结果 表明:湿燃气含湿量对透平叶片燃气侧的流动性能基本无影响;当湿燃气含湿量从0 g/kg增加到150 g/kg,主流进口温度为1473 K时,透平叶片表面平均传热系数增加10％,且增加幅度随着主流进口温度的升高而增大,叶片表面最高温度平均提高10 K;与干空气相比,湿空气作为冷却工质时的叶片表面温度更低,冷却效率更高,且冷却效率随着湿空气合湿量的增加而提高.     

叠置式增湿去湿太阳能海水淡化系统的稳态研究

设计了一台具有叠置结构的增湿去湿太阳能海水淡化系统,该系统可采用太阳能系统供热,也可利用其他余热系统供热。在稳态供热条件下,对系统的产水性能随热海水布水温度的变化进行了测试,并对该条件下性能系数进行了计算。结果表明:当喷淋海水温度为85℃时,系统的淡水产量可达到63.4 kg/h,单效时性能系数可达0.77;在关闭循环风机,仅依靠热湿空气自身升力的条件下,此温度下淡水产量约为37 kg/h,可达有风机时的58%,说明叠置式的分布设计是有效的。     

上海地区太阳能溶液除湿新风系统的TRNSYS模拟研究

以上海徐汇某别墅空调系统为例,利用TRNSYS软件对太阳能溶液除湿新风系统的运行情况进行数值模拟,以验证该系统夏季供冷工况下运行的稳定性和可靠性。主要模拟太阳能溶液除湿新风系统运行过程中新风经过各级除湿塔后含湿量的变化、除湿溶液经各级除湿塔后浓度的变化以及除湿溶液再生前后浓度的变化。结果表明:一、二级除湿塔的除湿效率较高,三、四级除湿塔的除湿效率相对较低;使用者可根据室外含湿量具体情况选择除湿塔运行级数,而四级除湿塔的联合运行能保证全夏季空调期内送风含湿量均低于设计送风含湿量11.22 g/kg;除湿溶液经四级除湿后的平均浓度保持在34%~35%之间,仍保留有一定的除湿能力;夏季空调期内溶液再生前后浓度差的平均值为6.48%,溶液再生效率高,能为除湿环节提供稳定的除湿浓溶液。太阳能溶液除湿新风系统运行稳定,能满足不同室内外气象参数条件下系统送风参数的要求。     

小型太阳能海水淡化装置

基于空气增湿-除湿海水淡化技术,采用热海水与空气逆流对喷的空气加湿器,设计了结合太阳能集热器的小型太阳能海水淡化系统。试验结果表明,该结构的空气加湿器具有很好的加湿效果,出口空气相对湿度可达到98%以上。当喷水温度为60℃、空气流量为11.8 L/s时,该小型海水淡化装置产水率可达3.42 kg/h。     

聚光直热式加湿除湿型太阳能海水淡化装置性能测试与经济性分析

对一种聚光直热式加湿除湿太阳能海水淡化装置进行实验测试,根据其产淡水速率和经济成本,对其长期运行的经济性进行分析。在室内稳定条件下,测试给出海水喷淋温度、加热功率等对产水速率的影响曲线。结果表明,采用双层加湿小球作为加湿层材料的系统产水效果最好,在喷淋温度为73℃时,其产水速率为1.12 kg/h。在实际天气下,也测试给出装置内部的工作温度和产水性能随时间的变化曲线。实验结果表明,在平均太阳直射辐照度为692 W/m~2时,最大产水速率达到0.52 kg/h,装置的平均性能系数达到0.84。     

逆流喷雾式饱和器内湿化过程的实验研究

对逆流喷雾式饱和器内部空气的湿化过程进行实验研究，实验中不仅测量了饱和器进出口湿空气的相对湿度、温度和水的温度，而且也测量了饱和器内部几个高度截面上湿空气的相对湿度和气相、液相的温度。根据实验测量的湿空气的相对湿度和温度，计算出了饱和器内湿空气的含湿量和测量高度间湿空气的加湿量。由实验结果可见，随水气质量比的增大,饱和器出口湿空气的温度和温升也相应增大。湿空气的含湿量和水的蒸发量、出口温度随进口水温升高、水气质量比增大而增大。在所有实验工况下，饱和器出口湿空气接近或达到饱和。随空气速度增大水滴逃逸量增大。总体上饱和器内部下部主要是加湿进口空气，上部是加湿和加热空气。     

热空气式加湿除湿海水淡化装置研究

基于喷淋水自循环与太阳能加热空气的方法,设计一种加湿除湿型海水淡化装置。首先对装置的结构及原理进行说明,然后对装置各部分的能量平衡进行分析,最后实验研究装置集热及产水性能。从实验结果可知,淡化装置所匹配的太阳能空气集热器效率在37%～50%之间,在循环风量为164.21 m~3/h、海水喷淋速率为971 kg/h以及淡水喷淋速率为896 kg/h的条件下,装置最大半小时产水量为2.2 kg。此外,研究结果显示,因喷淋水自循环,喷淋速率的变化对装置产水量的影响较小。     

An open heat pump process for moist gases

A heat pump process is proposed for the recovery of the latent heat of water vapour in waste heat gases. The process includes a humidifier where the moist waste gas is additionally humidified. The moist gas leaving the humidifier is pressurized in a turbocompressor. The dew point temperature of the gas is increased by the humidification and the compression. This is utilized by indirect heat exchange for the production of low pressure steam and for the required heat of vaporization in the humidifier. It should be possible to use the process for waste heat recovery from moist flue gases and from process gases such as dryer exhaust air. Performance data have been calculated for production of low pressure steam at 1.2 bar from moist air at atmospheric pressure, dry temperature 100°C and the absolute humidity 0.19 kg water vapour per kg dry air. With these data a coefficient of performance for the heat pump process has been calculated to be 2.8. 85% (m/m) of the waste heat has been recovered from the moisture content. For these calculations the pressurization in the compressor has been set to 4.0 bar. The process should be further investigated to find performance data under optimal operating conditions.     

泡沫陶瓷填料湿化器加湿性能实验研究

温化器是湿空气透平(HAT)循环的关键部件,其性能优劣对于循环的性能有着重要的影响.对采用新型SiC泡沫陶瓷填料的湿化器在加压条件下的湿化性能进行了实验研究,分析了水气比、进口水温、操作压力以及进口空气温度对湿化过程的影响,研究表明,提高水气比或进口水温会使进出口空气温差、含湿量差相应增加,湿化器节点温差增大.操作压力...     

Thermodynamic performance experiment and cooling number calculation of a counter-flow spray humidifier in the HAT cycle

An experimental investigation of the thermodynamic performance of a counter-flow spray humidifier was conducted on the basis of theoretical analysis of the heat and mass transfer mechanism inside the humidifier. Critical parameters such as the temperature and relative humidity of air and the temperature of water at the inlet and outlet were measured. The influence of every measured parameter on the thermal performance of the humidifier was obtained under different experimental conditions. The cooling number, whose variation was also obtained, was calculated according to the measured data. The experimental results show that both the temperature and the temperature increment of outlet humid air and the temperature of outlet water increase with an increase of the water-gas ratio, whereas the cooling number decreases. Under all experimental conditions, the outlet humid air reaches or is close to the saturation level. The lower cooling number is favorable for the system, but it has an optimal value for a certain humidifier.     

燃料电池空气系统增湿器建模与仿真

建立气-气增湿器的数学理论模型,并基于Amesim软件建立燃料电池增湿器及空气系统仿真模型,从燃料电池系统层面分析干湿侧不同温度、压力、水含量等输入条件下的干侧出口空气的湿度变化情况,并采用水转移率（water vapor transfer rate,WVTR）对增湿器增湿性能进行评价,结果表明此模型可进行前期验证,能较好地预测汽车运行过程中增湿器的动态响应特性。     

Thermodynamic performance experiment and cooling number calculation of a counter-flow spray humidifier in the HAT cycle

An experimental investigation of the thermodynamic performance of a counter-flow spray humidifier was conducted on the basis of theoretical analysis of the heat and mass transfer mechanism inside the humidifier. Critical parameters such as the temperature and relative humidity of air and the temperature of water at the inlet and outlet were measured. The influence of every measured parameter on the thermal performance of the humidifier was obtained under different experimental conditions. The cooling number, whose variation was also obtained, was calculated according to the measured data. The experimental results show that both the temperature and the temperature increment of outlet humid air and the temperature of outlet water increase with an increase of the water-gas ratio, whereas the cooling number decreases. Under all experimental conditions, the outlet humid air reaches or is close to the saturation level. The lower cooling number is favorable for the system, but it has an optimal value for a certain humidifier. __________ Translated from Journal of Power Engineering, 2006, 40(9): 1263–1267 [译自: 动力工程]     

Humidification-dehumidification water desalination system integrated with multiple evaporators/condensers heat pump unit

A study of the performance enhancement of a humidification-dehumidification (HDH) system integrated with multiple evaporators/condensers heat pump (HP) and heat recovery units is presented. The HP unit is intended to deliver necessary heating for humidifier and heating/cooling for dehumidifier in a new strategy. The proposed integrated system is capable to produce fresh water from the HDH system and HP unit. Four different configurations of the system formed by excluding/adding condensers and evaporators were investigated; mode-A (seawater precooling and reheating), mode-B (seawater reheating), mode-C (seawater precooling and humid air reheating), and mode-D (humid air reheating). Fresh water productivity, fresh water ratio, system water recovery, gain output ratio, specific work consumption, and fresh water production cost were used as performance measuring parameters of the system. The influences of operating parameters on the system performance were analytically studied and experimentally validated for different system configurations. The results indicate the enhancement of the systems' performance with increasing ambient air temperature and humidity, seawater and air flow rates, and with decreasing seawater temperature. The system configuration of mode-B shows the best performance with fresh water production of 61.94 kg/h and gain output ratio of 4.97 which are higher than those of the other configurations by 13%, 55%, 85% and 11%, 48%, and 75%, respectively. Comparisons of the proposed configurations with the other HDH desalination systems available in the literature were presented and better performance of the proposed systems was noticed.     

HAT循环逆流式湿化器的热力性能实验研究及冷却数计算

在理论分析湿化器内部传热传质机理的基础上，进行了湿化器总体热力性能试验，得出了在不同实验工况下，各测量参数对湿化器热力性能的影响规律，同时计算了冷却数，得出了其变化规律。结果表明：随水气质量比的增大，湿化器出口湿空气的温度、温升和出口水温都增大，而冷却数减少。在同一水气质量比下，随进口水温升高，出口湿空气温度、温升和出口水温都增大，冷却数减少。在各实验工况下，湿化器的出口湿空气都具有很高的相对湿度，达到或接近饱和状态。冷却数降低对系统有利，但不是越低越好，应该优化选择最佳值。     

Experimental analysis of evacuated tube solar air heater (ETSAH) with inbuilt sensible thermal energy storage

In the present work, an evacuated tube solar air heater (ETSAH) with inbuilt sensible heat storage material (SHSM) is experimentally evaluated. The system comprises two sets each having 50 evacuated tubes with an H-type arrangement and a total collector area of 16.92 m². For the purpose of hot air generation, ETSAH is simultaneously connected in series and in parallel with and without the use of reflectors. Three different mass flow rates of 122.90, 164.87, and 212.83 kg/h were fixed to get 12 diverse cases of ETSAH operation. The highest hot air temperature reported by the system is 121.7°C when it was connected in series with conventional reflectors at 212.83 kg/h of flow rate and 469 W/m² average solar intensity. The system reported an overall average energy efficiency of 49.76% and an exergy efficiency of 17.97% with the highest average hot air temperature difference of 56.12°C from 09:00 to 20:00 h. Without the incorporation of any additional SHSM, the average hot air temperature delivered by ETSAH (when under the neighbor building shadow) is 49.73°C logged from 17:00 to 20:00 h. The economic analysis is also carried out to ensure its practical application and feasibility. For the best system performance, the annual cost of hot air generation is 0.0194 Rs./kg (0.0002433 $/kg).