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首页> 外文会议>10th international conference on phase change materials and slurries for refrigeration and air conditioning >EXPERIMENTAL STUDIES OF THE HEAT DENSITY OF PARAFFIN AND GAS HYDRATE SLURRY
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EXPERIMENTAL STUDIES OF THE HEAT DENSITY OF PARAFFIN AND GAS HYDRATE SLURRY

机译：石蜡和天然气水合物浆液的热密度实验研究

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Due to the high increase of energy consumption and after Montreal and Kyoto protocols, it has beenrnnecessary to reduce power consumption and the propagation of the refrigerants in the atmospherernby improving the performances of the refrigerating machines. In this context, the use of ThermalrnEnergy Storage (TES) techniques could be an interesting solution.rnClassical secondary refrigerants, such as water and glycol aqueous solutions, are single phase fluidsrnlimited by their small cold carrying capacity. Moreover, secondary refrigerants need the use of additionalrnpumps leading to high thermodynamic irreversibilities. In order to combine a more efficientrnsecondary loop and fluids with higher energy storage capacity, a phase change material (PCM) slurryrncould be used as secondary refrigerant. In such systems, energy is stored mainly during a phasernchange process of the storage material and a carrier fluid should be used as a continuous phase. Thernobtained system is called Phase Change Slurry (PCS). PCS has a higher energy density than singlephasernsecondary refrigerants due to both sensible and latent heat capacities of the materials.rnIn the present work, three types of PCS systems were investigated: CO_2 hydrate slurry, paraffinrndispersion and hydrate-paraffin slurry. CO_2 hydrate slurry was already studied at Irstea (France) andrnit was found that its dissociation enthalpy (500 kJ.kg-1rnwater) was higher than that of ice (333 kJ/kg).rnStudies on paraffins latent heat enthalpy were already accomplished only under atmospheric pressurernat the Fraunhofer institute (Germany) and the total emulsion enthalpy was largely higher thanrnthen sensible heat of pure water. It was also shown that paraffin dispersions have good flowing capacities.rnThe purpose of this work is to combine CO_2 hydrate and paraffin dispersion systems inrnorder to reach a PCS system that combines the advantages in terms of melting enthalpy and flowingrncapacities. Therefore, a DTA device was used in which the phase change temperatures and the correspondingrnenthalpies for many PCS systems were measured. The best system must verify somernrequirements: stability over a large period of time, high storage density (higher than ice), goodrnflowing capacities and phase transformation between 0 and 20 ℃ under moderate pressure.
机译：由于能耗的大量增加，并且在蒙特利尔和京都议定书之后，有必要通过改善制冷机的性能来降低功耗和制冷剂在大气中的传播。在这种情况下，使用热能存储（TES）技术可能是一个有趣的解决方案。经典的二次制冷剂（例如水和乙二醇水溶液）是单相流体，受其较小的冷容量限制。此外，次级制冷剂需要使用额外的泵，从而导致高度的热力学不可逆性。为了将更有效的二次回路和具有更高能量存储能力的流体结合起来，可以使用相变材料（PCM）浆料作为二次制冷剂。在这样的系统中，能量主要在存储材料的相变过程中存储，并且载流子应用作连续相。获得的系统称为相变浆料（PCS）。由于材料的显热和潜热能力，PCS具有比单相二次制冷剂更高的能量密度。在当前工作中，研究了三种类型的PCS系统：CO_2水合物浆料，石蜡分散液和水合物-石蜡浆料。在法国的Irstea已经研究了CO_2水合物浆液，并发现rnit的离解焓（500 kJ.kg-1rnwater）比冰的解离焓（333 kJ / kg）高。rn仅在以下条件下才完成石蜡潜热焓的研究。弗劳恩霍夫研究所（德国）的大气压和总乳化焓大大高于当时的纯水显热。还显示出石蜡分散体具有良好的流动能力。这项工作的目的是将CO_2水合物和石蜡分散体系无序结合，以达到结合熔融焓和流动能力方面优点的PCS体系。因此，使用了DTA设备，其中测量了许多PCS系统的相变温度和相应的焓。最佳系统必须验证一些要求：长时间内的稳定性，高存储密度（高于冰），良好的流动能力以及在中等压力下0至20℃之间的相变。

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