共查询到19条相似文献,搜索用时 156 毫秒
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作者结合热泵循环的基本原理,对压缩式开路循环热泵蒸发装置进行了分析,通过与多效蒸发的实例对比,说明了采用热泵蒸发装置的节能效果和经济效益,并对实际生产应用中存在的问题进行了阐述。 相似文献
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文章提出了一种利用海洋温差能和风能联合发电的方法及装置。利用海洋表层的热海水加热低沸点工质,使之蒸发.送入汽轮机推动汽轮发电机组做功发电,汽轮机排出的工质乏气用海洋深层的冷海水冷凝为液态,再用热海水加热,送入汽轮机,使之蒸发,推动汽轮机发电机组做功发电,如此循环,持续发电;并且利用洋面风力发电,并用该电力驱动热泵装置.由热泵装置的媒质将工质的温度进一步提高.增大工质体积膨胀率;由热泵装置的媒质将冷海水的温度进一步降低.再用该低温海水去冷凝工质乏气,增强对工质乏汽的冷凝效果。该装置既需要用到小型透平,又需要用到风力发电装置.十分适合公司发展。 相似文献
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通过数值模拟计算,讨论与分析了三种基本风力集中器建筑型式(非流线体型、平板型和扩散体型)对风能利用的情况。根据模拟结果可知,三种风力集中器建筑型式对增大风速、强化风能利用均具有良好的效果。 相似文献
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《International Journal of Hydrogen Energy》2023,48(54):20694-20704
Liquid piston compressor is the most promising compressor to be used for hydrogen-refueling stations. However, their energy transfer and the energy dissipation processes of are poorly studied and not well understood. In this paper, a new energy analysis method for an ionic-liquid type liquid piston compressor is proposed. In the compressor section, porous media is used to promote heat transfer from the hydraulic oil during the compression process. A mathematical model has been formulated considering the heat transfer and damping effects of the porous media on the compressor performance. Moreover, the compressibility of the hydraulic oil and its overflow loss on the compressor performance were also established. In the model, the seven stages of the entire working cycle of the compressor were look into in detail, alongside with its energy efficiency. The results show that the key parameters governing the energy efficiency of the compressor are the heat transfer efficiency of the compressor and the overflow losses of the hydraulic oil. 相似文献
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机械蒸汽压缩海水淡化是一种很有前景的消纳风能的方式,其中的压缩机是这种能源利用方式的核心部件。建立了离心式蒸汽压缩机数学模型,研究了压缩机性能参数间的关系,重点探讨了压缩机输入功率及吸气蒸汽参数与压缩机流量、压比和转速间的关系,并通过耦合风力发电机模型,研究了定压比条件下,压缩机流量和转速在风力发电机随机功率变化时的响应曲线。结果表明,风力发电机驱动的机械蒸汽压缩机需要辅助能源来保证在较小的风力发电机输入功率情况下,压缩机能稳定运行在非喘振区。对于额定功率为160 k W的压缩机,在压比2.4条件下的最小输入功率为50 k W。 相似文献
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Focusing on the effective use of low-grade solar heat as heat source to provide refrigeration for residential and commercial space cooling, an absorption-compression hybrid refrigeration cycle has been studied on the basis of available data of working pair 1,1,1,2-tetrafluoroethane (R134a) and dimethylformamide (DMF). In order to investigate their performance, the energy saving mechanism of the hybrid cycle was analyzed, by means of thermodynamic diagrams of log p–T, log p–h and T–s. The results show that the hybrid refrigeration cycle has a relatively high thermodynamic perfectibility and can use low-grade heat to replace parts of mechanical work for obtaining lower temperature refrigeration effect owing to its energy complement and cascade refrigerating configuration between the internal sub-cycles. Moreover, on the basis of two new criteria, the heat powered coefficient of performance and the electricity saving rate, the competition behavior between the sub-cycles of the hybrid cycle, i.e. the trade-off effects of compressor pressure on the low-grade heat utilization performance were also investigated. It was found that the sub-cycles compete in their contribution to the hybrid refrigeration system and the cycle preferences depend on the dominance which one achieves. In other words, there is an optimum compressor outlet pressure region under specified working conditions, where the hybrid refrigeration cycle has the maximum heat powered coefficient of performance and electricity saving rate. 相似文献
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通过对机械蒸汽压缩(mechanical vapor compression,MVC)-多效蒸馏(multi-effect evaporator,MEE)海水淡化系统建立模型,研究了压缩机输入功率与海水淡化系统运行参数之间的关系,分析了系统中压缩机与多效蒸发器之间相互耦合的匹配关系,探讨了辅助能源加热对系统运行状态及产水率的影响,并通过耦合风力发电机模型,研究了系统淡水产率随风电功率随机变化的响应曲线。结果表明:随压缩机输入功率的增加,多效蒸发器效间的传热温差增大,产水率也近似线性增加;辅助能源虽然有助于提高产水率,但其添加量不能超过一定的上限;对于一组平均为7.1m/s的随机风速,海水淡化系统的平均产水率为5.00t/h,平均产水能耗10.2kWh/t,而若采用20%辅助能源加热,可以使平均产水率提高0.21t/h。 相似文献
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《Applied Thermal Engineering》2002,22(3):295-308
The construction of a triple-effect absorption cooling machine using the lithium bromide-based working fluid is strongly limited by the corrosion problem caused by the high generator temperature. In this study four compressor-assisted H2O/LiBr cooling cycles were suggested to solve the problem by lowering the generator temperature of the basic theoretical triple-effect cycle. Each cycle includes one compressor at a different state point to elevate the pressure of the refrigerant vapor up to a useful condensation temperature. Cycle simulations were carried out to investigate both a basic triple-effect cycle and four compressor-assisted cycles. All types of compressor-assisted cycles were found to be operable with a significantly lowered generator temperature. The temperature decrements increase with elevated compression ratios. This means that, if a part of energy input is changed from heat to mechanical energy, the machine can be operated in a favorable region of generator temperature not to cause corrosion problems. In order to obtain 40 K of generator temperature decrement (from 475.95 K) for all cycles, 3–5% of cooling capacity equivalent mechanical energies were required for operating the compressor. A great advantage of the investigated triple-effect cycles is that the conventionally used H2O/LiBr solution can be used as a working fluid without the danger of corrosion or without integrating multiple solution circuits. 相似文献
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Until now, the technical development of wind force is mainly combined with electrical generator and already achieves the skillful technique in application. In this paper the newly developed windchiller directly applies the mechanical energy of wind force for refrigeration instead of the traditional electrical/mechanical energy conversion. The devise avoids energy loss during the two to-and-fro energy conversion processes between wind force and electrical energy. The special finished wind machine applies the technique with two directions to capture the wind force, the faced and its opposite directions, in the fans design. Between the wind turbine and the compressor, a transmission system with a fixed conversion rate 1:20 was used for acceleration. After the combination with open-type reciprocating compressor, the wind forced chiller is built. The windchiller increases the working efficiency in comparison with the refrigerating system of indirect connection from wind generator to refrigerator and ignores the unstable property of wind force. The strength of wind force influences only the windchiller’s efficiency; the stronger wind force, the larger windchiller’s efficiency. The experimental results show the newly developed windchiller’s efficiency ca. 21.28%, which agrees to the pre-evaluation and achieves a high efficiency. 相似文献
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Xiaoqin Yang 《Nanoscale and Microscale Thermophysical Engineering》2013,17(2):171-196
This article examines the size effects on the performance of miniature refrigerators and liquefiers operated by the Linde cycle. The system sizes are cased into a function of the compressor characteristic length and the heat exchanger length while several cycle operation parameters are held constant. Simplified models of a Hampson-type counterflow heat exchanger and a reciprocating-type compressor were considered in the present analysis. For both the refrigerator and the liquefier, it was found that only for certain ranges of the compressor size is the system able to produce a heat exchanger effectiveness greater than the required minimum value. It was also found that there exists an optimal compressor size for obtaining maximum heat exchanger effectiveness, cooling effect, mass fraction of liquefied product, and coefficient of performance. For the refrigerator, the optimal compressor size for obtaining the maximum heat exchanger effectiveness is different from that for obtaining the maximum cooling effects because of the mass flow rate effect. For the liquefier, the optimal compressor sizes for obtaining the maximum heat exchanger effectiveness, mass fraction of liquefied gas product, and FOM are approximately the same. When the Claude cycle is employed, it is found that it theoretically offers a more satisfactory performance than the Linde cycle in the small size range. The FOM of a mesoscale system with the Claude cycle can reach the range of 20 to 23% with the liquid product temperature ranging from 65 to 90 K. 相似文献
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A Moisture Air Turbine (MAT) cycle is proposed for improving the characteristics of land-based gas turbines by injecting atomized water through an inlet into a compressor. Compressor work of isentropic compression for moist air mixtures with phase change is theoretically considered, which has revealed that water evaporation may reduce compressor work. An experiment using a 15 MW class axial flow load compressor has also verified the theory. Realistic cycle model calculations predict that a 10% power increment by a ratio of 1% water to compressor intake air is expected and also that the amount of water consumption is much less than that of conventional inlet air cooling systems, used for heat rejection at the cooling tower. In addition, thermal efficiency is anticipated to be improved mainly due to the reduction of compressor work. Contrary to the conventional evaporative cooler, a MAT cycle could provide power output at a desired value within its capability regardless of ambient humidity condition. 相似文献