太阳能耦合式空调及热水一体系统研究

为解决北方部分城市无集中供暖建筑空调问题,将太阳能与建筑空调及热水系统相结合,提出一种新型太阳能耦合空气源热泵空调及热水系统。通过热力学模型建立与求解,以兰州的气候数据为依据,分析了热泵性能系数(COP)与系统能耗的变工况特性,并基于特定工况,探讨了不同太阳能保证率下系统的节能减排效益。研究结果表明,在太阳平均辐照度为374 W/m²,冷凝温度为55℃,环境温度在-10～0℃的工况下,系统COP均高于3.5,拥有良好的性能。在全年空调期为220天,建筑面积为100 m²的房屋中,相较于普通的热泵系统,采用太阳能保证率为30%的耦合式空调系统一年可多节省2.1 t的标准煤,并减少5.56 t的二氧化碳排放量。     

小型水源热泵机组变工况运行实验研究

本文以自行设计、开发的水源热泵机组为例,通过实验,研究了该热泵在制热模式下,蒸发器侧供水温度和流量变化对系统的运行参数和能耗的影响规律。结果分析表明,系统耗功率随供水温度的升高而降低,随供水流量的增加而升高;提高供水温度或增加供水流量,系统制热量及供热系数均会增加,水温每升高1℃,制热系数COP平均增幅1.94%,供水流量每增加0.5m3/h,制热系数COP平均增幅6.75%,室内温度每提高1℃,制热系数COP平均降幅2.47%。     

太阳能辅助空气源热泵空调低温特性研究

为了改善和提高空气源热泵空调冬季低温环境下的工作性能,设计了以翅片-套管复合式换热器为核心部件,以太阳能低温热水作为辅助热源的太阳能辅助空气源热泵空调,并对该热泵空调进行了低温工况性能测试。实验结果证明,当室外环境温度低至-15℃时,太阳能辅助空气源热泵空调与单一空气源热泵空调相比,系统性能得到明显改善,COP提高50%以上。     

热气旁通制冷系统除霜特性的仿真研究

为了研究空气源热泵热气旁通在不同旁通阀开度下的除霜特性,以带热气旁通的汽车热泵空调系统为研究对象,结合实验数据建立系统稳态仿真模型,并通过模型仿真研究系统在一个除霜周期内不同开度下的除霜能量、除霜时间和平均COP。研究表明,除霜能量随开度增加呈现线性增大,当旁通流量为60%时,除霜能量可达321.7 W;除霜时间随开度增加而减小并趋于平缓;系统的最佳旁通开度为45%,此时系统在一个除霜周期内的平均COP可达1.957。     

准二级压缩空气源热泵系统的变工况试验研究

介绍了准二级涡旋压缩机空气源热泵系统,对研制出的具有蒸汽喷射的涡旋压缩机空气源热泵系统样机进行了大范围变工况试验研究,获得机组在各工况下的输入功率、制热量、COP、排气温度的变化。通过变工况实验,综合考虑制热量、COP和机组工作稳定性,得出准二级压缩热泵系统最佳中间补气压力为1200kPa~1400kPa。研究结果可为准二级压缩系统设计与应用提供参考。     

气液双热源耦合热泵空调性能模拟研究

建立了气液双热源耦合换热器的耦合换热模型,并对其在耦合热源热泵空调中应用时的制热工况进行了性能模拟研究。模拟结果显示,使用该气液双热源耦合式换热器的耦合热源热泵空调系统,气液双热源模式与单空气热源模式相比,制热量和COP均有明显提高,低温时性能提高更为显著。当室外温度为-15℃时,双热源热泵的制热量较单一空气源热泵提高比例进一步增大,制热量提高近40%,COP提高近30%。     

办公楼地源热泵空调系统夏季运行特性

以泰安市某办公楼地源热泵系统为研究对象,通过对夏季运行工况的实时监测,得到地源侧出水温度、负荷侧回水温度、机组COP和机组制冷量随室外气温的变化特性。研究结果表明,地源侧出水温度波峰较室外气温波峰滞后22h;机组COP和机组制冷量不仅与室外气温有关,还与空调末端供冷需求有关,在供冷需求相同的情况下,室外气温每升高1℃,机组COP、制冷量升高2.5%;在室外温度相同的情况下,地源侧出水温度每升高1℃,机组COP降低5%。该研究结论为地源热泵空调系统的设计、节能运行提供了必要的参考。     

双热源空调-热水器一体机冬季制热的实验研究

冬季室外温度低时,空气源热泵系统的蒸发器会结霜,使系统COP降低。所设计的空调-热水器一体机可以制冷、制热、一年四季提供生活用热水。冬季室外温度低时,用太阳能加热后的水作为热泵的低温热源,可以提高热泵的效率。分别用空气源蒸发器和水源蒸发器独立工作使系统给房间制热,实验结果发现水源蒸发器工作时系统的COP平均值为3.56,空气源蒸发器工作时的COP平均值为2.51。     

带经济器的热泵型客车空调系统实验研究

开发并搭建了一套用于纯电动客车的带经济器补气型热泵空调系统实验台,进行了车外各低温环境温度不补气与补气模式下的供热性能实验研究。实验研究结果表明:在车外环境为-20℃超低温环境温度下,经济器补气型热泵空调系统较不补气热泵系统制热量增加54.98%,排气温度降低15℃左右,COP提高41.2%,可较好地解决普通热泵空调低温制热性能差的突出问题。     

热泵型纯电动客车空调结霜特性实验研究

针对热泵型纯电动客车空调系统在冬季低温高湿环境下,车外换热器易结霜而造成系统制热性能严重衰减的问题,开发了一种带有经济器的补气型纯电动客车热泵空调系统,对车外管翅式换热器结霜特性进行了实验研究。结果表明,当车外换热器完全结霜后,系统制热量和COP均大幅下降。由于采用中压补气技术,系统仍能稳定运行,当车外温度为0、-10、-20℃时,结霜过程中系统制热量分别降低了5、3.2、2.3 kW,COP分别降低了1.1、0.7、0.45,且车外空气相对湿度越大,系统制热性能衰减越严重。     

具有预脉冲屏蔽板的水介质自击穿开关的电路模拟

 介绍了具有预脉冲屏蔽板的水介质脉冲形成开关的结构和等效电路模型，给出模型中等效参数的计算方法。使用Pspice软件对该模型进行了电路模拟，着重分析预脉冲屏蔽板结构对输入、输出脉冲的影响，同时分析了开关电感和电极间隙电容对电压波形的作用。模拟结果表明，开关输入、输出端的对地电容对电压波形影响很大，开关电感和电极间隙电容的影响相对较小。对比“闪光二号”加速器上进行的水介质自击穿开关实验波形和模拟波形，说明在一定范围内等效模型是可以采用的。设计开关结构时，应先合理调整屏蔽板的位置以确定其对地电容，尽量兼顾减小开关电容和电感，屏蔽板开孔大小需选取适当。     

Sonochemical treatment of natural ground water at different high frequencies: preliminary results

Naturally occurring ground water polluted by highly volatile chlorinated compounds, with 1,2-dichloroethane as the main contaminant, was sonicated with high frequency ultrasound (361, 620 and 1086 kHz) in order to investigate if results from studies performed with single model compounds in water can be applied to a natural ground water. It was shown that the treated highly volatile halogenated hydrocarbons are almost completely destroyed by ultrasound in natural ground water within 60 min. It also transpired that the naturally occurring inorganic components and gases in the ground water play an important role.     

Tuning the continuum ground state energy of NO2- 2 by water molecules

Electron scattering on NO-2, NO-2 x (H2O), and NO-2 x (H2O)(2) was performed in two storage rings. We confirm the presence of earlier reported NO2-2 dianion resonances and show that they remain when water is attached. Importantly, hydration tunes the energy: each water molecule lowers the ground state energy by 0.8 +/- 0.3 eV relative to the monoanion. NO2-2 is observed to decay by two-electron emission, possibly in combination with fragmentation. NO(2-)2 x (H2O) mainly decays into NO-2 + H2O + e(-).     

One-dimensional approximation of the effective rotational Hamiltonian of the ground state of the water molecule

A method is presented for summation of the divergent perturbation-theory series used in molecular spectroscopy, by means of a one-dimensional approximation. Application of the proposed method enables one to fit the energy levels of the ground state of the water molecule (Mol. Phys. 32, 499–521 (1976)) to a maximum difference between the observed and the calculated levels of less than 8 cm^?1 for levels with the maximum rotational quantum numbers K = 20 and J = 20 in a model with 24 parameters and terms up to J⁸.     

Sonolytic degradation of volatile pollutants in natural ground water: conclusions from a model study.

In order to evaluate the possibilities of an ultrasound-based cleaning technology, the effects of sonication on pollutants in a contaminated natural ground water were investigated. After the discussion of the results from this model study on the sonolytic degradation of volatile organic compounds, some consequences are reported and the important role of water components is described. Furthermore, the use of sonication as a cleaning technology for polluted water is discussed based on the conclusions from this study.     

A study of water releases in ground (GCC) and precipitated (PCC) calcium carbonates

Precipitate calcium carbonates (PCCs) are important industrial products mainly used as fillers. Because of their regular, synthesized characteristics (e.g. grain shape or grain size distribution) PCCs are distinct from natural ground calcium carbonates (GCCs). A thermal study on GCC samples showed only the presence of surface physisorbed water with a monotonic weight loss up to the carbonate decomposition. In the case of PCC samples, two supplementary water releases were observed. The first one appeared at around 525 K and the second one at around 725 K. The nature of the water present in two different PCC samples was investigated by thermal analyses (thermogravimetric and Karl Fischer analyses), Rietveld analyses on X-rays powder diffraction, infrared and Raman spectroscopies and solid state ¹H MAS NMR. The second water release at about 725 K was clearly identified as being portlandite dehydration. Ca(OH)₂ was present in the PCC in an amorphous state. Its crystallization occurred simultaneously to the first water release at about 525 K. Structural effects observed on calcite during the first water release led to the assignment to structural water molecules inserted in the structure of calcite.     

Ultra trace determination of fluorobenzoic acids in reservoir and ground water using isotope dilution gas chromatography mass spectrometry

The accurate ultra-trace analysis of six fluorobenzoic acids (FBAs) via isotope dilution gas chromatography mass spectrometry through their deuterated analogues is described. North Sea reservoir and ground water samples were spiked with six deuterated FBAs (dFBAs), enriched using solid-phase extraction (SPE) and analysed using GC/MS after derivatisation with BF ₃· MeOH. All FBAs were enriched and determined simultaneously. SPE allowed a 250-fold enrichment of the acids if 100 mL of sample volume was used. The method enables the determination of FBAs down to the range of 8–37 ng L ^?1 with recoveries between 66 % and 85 %. It uses low amounts of chemicals and is adaptable to larger and smaller sample volumes.     

地对地导弹可见光与红外成像导引头技术研究

图像制导导引头信息处理是当今精确制导武器的关键技术之一。首先讨论了地对地导弹可见光与红外光学导引头技术的国内外研究现状,然后结合导弹使用的实际需要给出了研究方案.基于该方案的可见光与红外光学末制导模块基本能够满足地对地导弹的实际要求.最后介绍了业已取得的技术成果,包括:典型目标的快速自动识别算法,图像复原算法,图像融合算法的实验结果,以及双通道四DSP图像融合硬件平台。