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王勤何巍王世宽郝楠徐象国陈光明徐璐陈达 《工程热物理学报》2014,(6):1053
本文搭建了带溶液泵的循环实验装置,并进行了提升管直径分别为6 mm、8 mm和12 mm的气泡泵用于输送12.5%、15%和17.5%三个质量浓度R134a-DMF溶液的性能实验。结果表明,在相同的R134a浓度下,三种管径气泡泵的气相流量随着输入功率的增加均呈大致线性增加趋势,提升效率随着气相流量的增加均明显减少,发生温度均随着输入功率的增加而线性增加,而输入功率对系统压力的影响不大。在相同的R134a浓度和相同气相流量下,8 mm管径气泡泵的提升效率最高,6 mm管径气泡泵的提升效率最低,R134a的浓度对提升效率的影响不明显。随着提升管直径的增大,气泡泵的启动加热量在所有R134a浓度下均增加,R134a的浓度对发生温度的影响不明显,但对系统压力的影响很大。这些实验结果对扩散吸收制冷系统的气泡泵设计具有重要参考价值。 相似文献
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一种扩散吸收式制冷系统的性能实验 总被引:2,自引:0,他引:2
设计了一套带有气液分离精馏设备的吸收扩散制冷装置,试验研究了提升管结构、热源加热温度、氨水浓度、充气压力对制冷装置的影响。新型的精馏结构在提高发生氨气纯度的同时,也可减少冷凝器的负荷(冷凝器进口温度为55℃左右)。实验在环境温度T0为25-35℃,溶液浓度ξ为25%-35%,充注压力P0为13-18 MPa,加热功率Pg为220-320 W的范围内进行。结果表明:浓度的提高可获得较大的冷量,一般28-32%为宜;适当的增加系统压力可降低蒸发温度;系统的冷量随加热功率的增加而提高;确定了提升管结构参数的选取。 相似文献
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A new model of a quantum refrigeration cycle composed of two adiabatic and
two isomagnetic field processes is established. The working substance in the
cycle consists of many non-interacting spin-1/2 systems. The performance of
the cycle is investigated, based on the quantum master equation and
semi-group approach. The general expressions of several important
performance parameters, such as the coefficient of performance, cooling
rate, and power input, are given. It is found that the coefficient of
performance of this cycle is in the closest analogy to that of the classical
Carnot cycle. Furthermore, at high temperatures the optimal relations of the
cooling rate and the maximum cooling rate are analysed in detail. Some
performance characteristic curves of the cycle are plotted, such as the
cooling rate versus the maximum ratio between high and low ``temperatures'
of the working substances, the maximum cooling rate versus the ratio between
high and low ``magnetic fields' and the ``temperature' ratio between high
and low reservoirs. The obtained results are further generalized and
discussed, so that they may be directly applied to describing the performance
of the quantum refrigerator using spin-$J$ systems as the working substance.
Finally, the optimum characteristics of the quantum Carnot and Ericsson
refrigeration cycles are derived by analogy. 相似文献
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An irreversible model of an Ericsson cryogenic refrigeration cycle working with an ideal Fermi gas is established, which is
composed of two isothermal and two isobaric processes. The influence of both the quantum degeneracy and the finite-rate heat
transfer between the working fluid and the heat reservoirs on the performance of the cycle is investigated, based on the theory
of statistical mechanics and thermodynamic properties of an ideal Fermi gas. The inherent regeneration losses of the cycle
are analyzed. Expressions for several important performance parameters such as the coefficient of performance, cooling rate
and power input are derived. By using numerical solutions, the cooling rate of the cycle is optimized for a given power input.
The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal regions of the coefficient
of performance and power input are determined. Especially, the optimal performance of the cycle in the strong and weak gas
degeneracy cases and the high temperature limit is discussed in detail. The analytic expressions of some optimized parameters
are derived. Some optimum criteria are given. The distinctions and connections between the Ericsson refrigeration cycles working
with the Fermi and classical gases are revealed.
相似文献