共查询到19条相似文献,搜索用时 125 毫秒
1.
2.
3.
4.
5.
《工程热物理学报》2016,(2)
为了深入研究逆布雷顿空气制冷机的降温特性与制冷性能,论文首先采用CFX数值模拟方法,对透平膨胀机冷端通流部分的流动与热力学过程进行了数值模拟,进一步对整机的热力性能进行了分析;在此基础上探讨了制动功率对膨胀机降温特性影响;并改进了逆布雷顿空气制冷机综合实验台,采用风机回路闭式循环,进行了定制动压力和定特性比两种典型制动策略下制冷机降温性能的实验研究。结果表明:通过调节风机闭式循环制动压力来匹配膨胀机工况的变化方案可行,理论预测与实验结果吻合较好;透平膨胀机的绝热效率62%,在120 min内制冷机最低无负荷出口温度达到了-170℃;采用透平膨胀机的逆布雷顿空气制冷机具有优异的制冷性能。 相似文献
6.
7.
8.
9.
10.
11.
12.
This paper studies the acoustics of a frost free three door domestic refrigerator. Then, as a case study, the radiated noise reduction in the refrigerator using a natural material base composite is presented. Composites manufactured out of Jute, which is a plant fiber abundantly and cheaply available in India and Bangladesh are used in the noise reduction in the refrigerator. Mostly in this work, composites made out of felts of jute were used as barriers for noise control of the refrigerator. Measured acoustical, thermal and physical properties of various jute composites are reported. Noise sources in the refrigerator were characterized using sound intensity method and sound pressure level measurements. It is found that the compressor and the evaporator fan are the predominant noise sources. The jute composite treatment done to the refrigerator shell around the evaporator fan reduced the refrigerator noise level by 5 dB and improved its measured sound quality metrics without affecting the cooling performance of the refrigerator. 相似文献
13.
有限大低温热源混合工质节流制冷循环特性分析 总被引:3,自引:0,他引:3
通过深入分析和比较各种单级压缩混合工质节流制冷循环在低温热源为有限大热源时的热力学性能,揭示了不同循环型式之间的内在热力学关系,阐明了该类节流制冷机能够实现深度制冷的内在原因是利用了制冷机的内部热交换来减少节流制冷机所固有的节流过程的不可逆损失,并用实验进行了验证。 相似文献
14.
15.
16.
17.
18.
低温回热器模型REGEN 总被引:1,自引:1,他引:0
回热器是低温制冷机的核心组件,完成回热器的热设计与结构设计等于说完成了回热式低温制冷机设计的主体。通过建立回热器内流体与回热填料的质量方程、动量方程和能量方程并求解可确定制冷机的理论设计性能指标。运用解析方法求解回热器数学物理模型相当困难,因此广泛采用数值求解方法。总结了目前国际上主流的回热器物理数学模型,介绍并比较回热器性能仿真软件REGEN、Sage和DeltaE,重点介绍REGEN的原理、特点、功能和应用等方面,并指出其不足之处和发展方向。 相似文献
19.
《Heat Recovery Systems and CHP》1993,13(4):363-371
Since 1979, long-life, reliable heat-powered sorption refrigeration systems have been developed for spacecraft use at the Jet Propulsion Laboratory (JPL). JPL has successfully built and tested a series of cryogenic sorption refrigeration systems for spacecraft sensor cooling and is presently assembling a −263°C (10K) hydride sorption refrigerator, which will fly on the Space Shuttle in 1994. With the addition of novel regenerative heating techniques, this same technology has more recently been applied to design high efficiency, ground-based adsorption heat pumps. Using actual sorption isotherm data and detailed analytic thermal computer models, analysis has predicted that the cooling and heating COPs will be significantly better than for any other single stage, heat-powered heat pump. Specifically the cooling COP (COPc) with the new regenerative system using ammonia is predicted to be as high as about 1.16. Recent tests on a single carbon sorbent canister compressor have been performed with R22, R134a, and ammonia. Transient thermal response of the sorption compressor has compared well with computer predictions. With ammonia, the total amount of average cooling from the 0.51 kg bed of carbon has been measured to be about 1038 Btu h−1 (304 W) for a 6 min full cycle including both heating and cooling. 相似文献