共查询到18条相似文献,搜索用时 46 毫秒
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混合物和纯氮工质在一种JT节流制冷机上热力性能的对比实验 总被引:1,自引:0,他引:1
报道了采用混合物工质及纯氮工质在一种开式快速JT节流制冷机上的实验对比研究。采用纯氮工质在压力为11.0Mpa左右,该JT节流冷机可获得的最低温度为83-84K,启动时间是75S左右;而采用混合物质后,在压力为5.0MPa左右,该制冷机可获得73-74K的最低温度;降温时间与纯氮相当。 相似文献
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对工作在50~80K的混合物工质J—T节流制冷机作了初步的热力学分析。采用混合物工质在一种开式J—T节流制冷机上作了实验研究 相似文献
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液氮温区J—T节流制冷机多元低温混合物工质热力循环优化设计 总被引:1,自引:0,他引:1
报道了针对液氮温区混合物工质J-T节流制冷机的热力循环优化计算。作者以制冷循环的卡诺系数为目标函数,考虑了压缩机的容积效率及换热器的传热温差损失等实际情况,采用复合形优化算法,在给定热力条件下来优化混合物最佳配比和循环最佳运行压力参数,计算结果对实际混合物制冷循环设计有一定指导意义。 相似文献
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一种基于深冷混合工质节流制冷机的高真空水汽捕集器 总被引:1,自引:0,他引:1
详细介绍了一种新型的高真空深冷水汽捕集器.该深冷水汽捕集器采用单压缩机驱动的混合工质节流制冷机冷却,制冷系统采用商用单级油润滑压缩机驱动,在配套600 L涡轮分子泵时,压缩机的额定输入功率450 W,捕集器表面温度最低为110 K.在相同真空测试条件下,开启低温捕集器可使系统极限真空度和抽速均提高一个数量级.该新型深冷捕集器具有优异的性能、低廉的造价及高可靠性等特点,与其他高真空获得设备如涡轮分子泵结合可成为一种优异的洁净高真空获得系统. 相似文献
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多元非共沸混合工质应用于深冷节流制冷机中,显著提高了制冷系统效率,得到了广泛应用.但是有多种因素会促使多元混合工质循环浓度变化,即最终循环混合物浓度与初始配制浓度不同,从而造成系统性能也发生变化.就混合物各组元浓度变化特性对制冷系统性能造成的影响进行敏感性分析.结果表明,不同组元在制冷系统中作用不同,存在关键组分,其浓度变化对制冷机性能影响显著.分析结果将有助于提高实际制冷系统性能,并加深对深冷多元混合工质工作机理的认识. 相似文献
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本文通过一项改进直冷式双温双控冰箱性能的试验,提出了一些实用有效的节能、降噪的技术手段,为冰箱制冷系统的优化设计提供参考。 相似文献
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混合工质节流制冷循环的优化原则及其应用 总被引:3,自引:0,他引:3
提出了在混合工质制冷循环优化中应遵循的三条较为合理和切实可行的优化原则。在此基础上,采用定循环运行压比优化方法,在较为合理的外部约束条件下,对二元混合工质循环进行了优化计算,分析了各设计变量对循环性能的影响,并进行了实验验证。 相似文献
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S. N. PATNAIK R. M. CORONEOS J. D. GUPTILL D. A. HOPKINS 《International journal for numerical methods in engineering》1996,39(10):1761-1774
Non-linear programming algorithms play an important role in structural design optimization. Fortunately, several algorithms with computer codes are available. At NASA Lewis Research Centre, a project was initiated to assess the performance of eight different optimizers through the development of a computer code CometBoards. This paper summarizes the conclusions of that research. CometBoards was employed to solve sets of small, medium and large structural problems, using the eight different optimizers on a Cray-YMP8E/8128 computer. The reliability and efficiency of the optimizers were determined from the performance of these problems. For small problems, the performance of most of the optimizers could be considered adequate. For large problems, however, three optimizers (two sequential quadratic programming routines, DNCONG of IMSL and SQP of IDESIGN, along with Sequential Unconstrained Minimizations Technique SUMT) outperformed others. At optimum, most optimizers captured an identical number of active displacement and frequency constraints but the number of active stress constraints differed among the optimizers. This discrepancy can be attributed to singularity conditions in the optimization and the alleviation of this discrepancy can improve the efficiency of optimizers. 相似文献
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多元混合工质精馏循环的优化计算与实验研究 总被引:1,自引:0,他引:1
结合多元精馏的操作型计算,采用了网格穷举法和机理法相结合的成分优化方法,对多元混合工质精馏循环进行了数值优化计算,得到了压比为8。温度为-60,-80,-100,-120℃等4个温度位的混合工质最佳成分,并进行了实验验证。 相似文献
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《低温学》2016
Non-flammable mixed refrigerant (NF-MR) Joule Thomson (J–T) refrigerators have desirable characteristics and wide cooling temperature range compared to those of pure J–T refrigerators. However, the operating challenge due to freezing is a critical issue to realize this type of refrigerator. In this paper, the solid–liquid phase equilibria (i.e. freezing point) of the NF-MR which is composed of Argon (Ar), R14 (CF4), and R218 (C3F8), has been experimentally investigated by a visualized apparatus. The accuracy of the apparatus is experimentally verified with pure refrigerants and selected binary mixed refrigerants. Freezing points of the ternary NF-MRs have been measured with the molar compositions from 0.1 to 0.8 for each component. Each test result is simultaneously acquired by a camcorder for visual inspection and temperature measurement during a warming process. Experimental results reveal that the specific MR, with R14 molar composition higher than 0.4, can achieve remarkably low freezing temperature even below 77 K. These unusual freezing point depression characteristics of the MR can be a useful information for designing a cryogenic MR J–T refrigerator to reach temperatures less than 77 K. 相似文献