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1.
微胶囊相变蓄冷材料的制备及其性能研究   总被引:1,自引:0,他引:1  
邢琳  方贵银  杨帆 《真空与低温》2006,12(3):153-156
阐述了微胶囊相变蓄冷材料的制备方法及其性能。采用复合凝聚法制备了微胶囊相变蓄冷材料。用明胶和阿拉伯胶作囊材、十四烷作芯材,使用示差扫描量热仪(DSC)来测定蓄冷材料的熔化温度、熔化潜热、凝固温度、凝固潜热,用热重分析仪(TG)测定其热稳定性,并用扫描电镜(SEM)观测了材料的微相结构。测试结果表明,该相变蓄冷材料具有较高的相变潜热和较好的热稳定性,可用作空调的蓄冷材料。  相似文献   

2.
蓄冷空调新型相变蓄能材料热性能研究   总被引:1,自引:0,他引:1  
通过实验分析了空调蓄冷材料的凝固点、融点、融解热和相变过程中的热稳定性等热学性能。在热分析中 ,用示差扫描量热仪 (DSC)来测定蓄冷材料的融解热 ,温度传感器用来测定蓄冷材料的凝固点和融解点。通过热分析寻找到了一种新型蓄冷材料 ,其测试结果表明 :该蓄冷材料是蓄冷空调系统中一种高效的蓄冷材料  相似文献   

3.
TiO2-WATER相变蓄冷纳米复合材料是一种新型的空调蓄冷介质.用差示扫描量热法测试了其熔解潜热,结果显示熔解潜热比水的低,但由于其熔解温度低于水的熔解温度,相变蓄冷纳米复合材料比水具有更大的显热储存能力.  相似文献   

4.
分析了当前空调蓄冷材料的研究现状及存在的一些问题,提出一种新型的相变蓄冷材料,该材料相变温度适宜,相变潜热大,具有重大的现实意义和实用价值.通过对KCL溶液的相图分析和热力性能的研究,联系实际应用情况,研制出一种新型相变组合材料,其相变温度在-5℃左右,相变潜热为280KJ/Kg.性能稳定,节能效果好,非常适合应用于低温送风与相变蓄冷相结合的空调系统中.  相似文献   

5.
四丁基溴化铵相变蓄冷材料热物性实验研究   总被引:3,自引:0,他引:3  
通过实验对四丁基溴化铵(TBAB)溶液的蓄冷结晶过程进行了测试,结果表明TBAB溶液的凝固温度随其浓度的改变而改变,在25%~45%的浓度范围内,其凝固温度位于5.8~9.3℃范围内.选取相变温度适宜、相变过程稳定、浓度为40%的TBAB溶液,向其添加硼砂成核剂,测试其相变温度和相变潜热,测试结果表明质量浓度为2%的硼砂在不影响TBAB溶液凝固温度的情况下可以降低其结晶过冷度2.4℃.采用示差扫描量热仪(DSC)测试TBAB溶液的熔解潜热为187.030kJ/kg.因此TBAB溶液是一种高效的空调蓄冷材料.  相似文献   

6.
小型蓄冷空调系统研究   总被引:3,自引:0,他引:3  
方贵银  徐锡斌 《制冷》2003,22(1):5-8
本文阐述小型蓄冷空调系统的工作原理和循环系统,并通过实验分析了相变蓄冷材料的凝固点、融解点、融解热等热学性能。在热性能分析中,用示差扫描量热仪(DSC)来测定蓄冷材料的融解热,用温度测量仪器来测定蓄冷材料的凝固点和融解点,通过热性能分析找到了一种新型蓄冷材料,该蓄冷材料可被应用于小型蓄冷空调系统中。  相似文献   

7.
有机相变材料在空调蓄冷中的应用是今后一个重要的发展方向,选取壬酸、辛酸、癸酸、月桂酸、正癸醇、月桂醇和肉豆蔻醇7种有机物质作为研究对象,两两组合,根据热力学第二定律和相平衡理论,预测出不同比例二元混合材料中的相变温度和相变潜热。通过DSC测试各组样品的热物性,制备筛选出适用于空调场合使用的二元有机相变蓄冷材料。结果表明:辛酸/月桂醇、癸酸/月桂醇和辛酸/肉豆蔻醇3组二元混合材料的相变温度范围为5~9℃,相变潜热范围为145~172kJ/kg,符合空调蓄冷要求;上述混合体系中辛酸/肉豆蔻醇(质量比73.7∶26.3)样品的性能最好,其相变温度为6.9℃,相变潜热为169.1kJ/kg。  相似文献   

8.
本文阐述了自行研制的蓄冷材料相变温度与相变潜热实验装置的特点 ,并在该实验装置上测试了蓄冷材料的相变温度和相变潜热 ,获得了较准确的结果。该方法简单易行 ,可用于工程上测量相变蓄冷材料的热物性  相似文献   

9.
蓄冷材料相变温度与相变潜热实验研究   总被引:5,自引:0,他引:5  
阐述了自行研制的蓄冷材料相变温度与相变潜热实验装置的特点,并在该实验装置上测试了蓄冷材料的相变温度和相变潜热,获得了较准确的结果。该方法简单易行,可用于工程上测量相变蓄冷材料的热物性。  相似文献   

10.
随着家用空调的日益普及,空调耗电量急剧增加。我国开发与推广小型家用蓄冷空调器,其转移尖峰用电负荷的潜力将比在中央空调系统上发展蓄冷空调大得多。小型家用蓄冷空调系统采用外融冰蓄冷,可以明显地节省运行费用;系统采用直接蒸发方式进行蓄冷,可避免冷热转换的中间环节,减少了能耗;相变温度为5~8℃的相变材料利用潜热进行蓄冷,可以改善制冷系统的运行特性。因此研制冰蓄冷与相变材料蓄冷混合的蓄冷空调系统是有意义的。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
13.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

14.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

15.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

16.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

17.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.  相似文献   

20.
Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.  相似文献   

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