毛细管流量对冰箱运行性能影响的研究

以某AQR-TZ42k型号冰箱为研究对象,对不同毛细管流量条件下的节能效果进行了对比研究。实验研究发现:使用12 L/min、7 L/min、5 L/min毛细管流量分别进行测试,当毛细管流量为5 L/min时,整机稳定段耗电量最低为0.70 kW·h/24 h,随着流量增加,耗电量分别升高3%、14%;采用双毛细管分时控制,使用5 L/min(低负荷)+5 L/min(高负荷)、7 L/min(低负荷)+7 L/min(高负荷)、12 L/min(低负荷)+12 L/min(高负荷)毛细管流量分别进行测试,当采用5 L/min(低负荷)+5 L/min(高负荷)组合时,冰箱(含化霜段)耗电量最低为0.80 kW·h/24 h,随着流量增加,耗电量升高6%、19%。实验结果说明,通过分时控制毛细管流量,可有效提升冰箱节能效果。

毛细管气体流量特性研究

通过实验研究,得出了气体在毛细管中流动时的沿程能量损失规律,经过数据处理,拟合出了毛细管的气体流量随毛细管内径、长度的变化曲线及其变化率曲线,得出了其韦泊分布函数。拟合出了毛细管的气体流量随压力差变化的曲线及其直线函数。为制冷系统的设计匹配以及毛细管批量生产的质量检验提供了一些非常有益的参考。

可变流量的变频冰箱(柜)制冷系统

通过变频压缩机控制器控制连接毛细管的电磁阀来换向制冷系统中并联接入的不同长度毛细管,实现制冷系统中的流量改变,从而变频压缩机在工作过程中运行状态和冷冻负荷的变化相匹配,达到节能的效果。

R290在小容积家用冰柜上的应用研究

本文以一款200 L和一款300 L小容积家用冰柜作为研究对象,通过适当优化冷凝器设计和毛细管流量设计,以及通过灌注量调试获得合理的制冷剂充注量等调试后,R290制冷系统与对应的R600a系统对比,耗电量基本相当,冷冻能力提升约70%,43℃高环境温度下的降温速度提升约45%,43℃高环境温度下的间室储藏温度平均值降低约6℃,噪声水平稍差,偏高约2 dB(A)。

电磁场-渗流场耦合作用下离子液体多孔介质流动模型

离子液体是一类可调控、多功能的绿色环保材料,具有良好的电磁场响应,有望应用于调控水驱油路径.在分析离子液体在毛细管中电磁场响应机理的基础上,建立了电磁场-渗流场耦合作用下离子液体多孔介质流动模型.通过理论推导与数值分析发现:电磁场-渗流场耦合作用下毛细管流量大小主要由离子液体电导率与黏度的比值(内因)、电磁场强度与压力梯度(外因)两方面决定;电磁场产生的洛伦兹力对离子液体施加一个电磁驱动压强,形成一个类似压力梯度的电磁驱动等效压力梯度,从而改变离子液体的流量,当电磁场强度为2.0×104 V/m·T时,电磁场在电导率为0.5 S/m的离子液体上可形成10 k Pa/m电磁驱动等效压力梯度.通过调整电磁场方向即可控制离子液体在多孔介质中的流动方向,解决常规注水利用压力差难以控制流动路径的难题,为离子液体智能驱油提供理论依据,且电磁场产生的热效应会影响离子液体的流动能力及潜在驱油效率.

Capillary blood flow in patients with dysmenorrhea treated with acupuncture

OBJECTIVE: To observe capillary blood flow at acupoints during acupuncture treatment of primary dysmenorrhea and gain new insights into its analgesic mechanism. METHODS: Patients with primary dysmenorrhea were enrolled and randomly assigned to a treatment or control group. Subjects' symptoms were differentiated into variousTraditional Chinese Medicine(TCM) syndromes and treated for 10 sessions with puncturing acupuncture or self-pressing right-hand Hegu(LI 4), adding other acupoints based on syndrome. Laser speckle was used to compare the change in the vasomotor amplitude and perfusion of the capillaries in Hegu(LI 4) before and during the treatment. Each subject was required to finish the period pain symptoms observation form, verbal rating scales, numerical rating scale, pain rating index, face rating scale, Zung self-rating depression scale, Zung self-rating anxiety scale, and numerical rating scale before and after treatments. RESULTS: After 10 sessions, the symptom scores, pain index(PI), and visual analog scale(VAS) decreased significantly in treatment group. The volume of blood flow in Hegu(LI 4) declined slightly. No significant evidence supported that needling caused capillary contraction, but the capillary vasomotor amplitude at Hegu(LI 4) increased remarkably. CONCLUSION: Acupuncture can increase the capillary blood flow, thus promoting the flow of Qi and blood in terms of TCM theory, which facilitates pain relief.

Comparison of the Effects of Traditional Box-Moxibustion and Eletrothermal Bian-Stone Moxibustion on Volume of Blood Flow in the Skin

Objective: To investigate and compare the effects of Electrothermal Bian-stone moxibustion and traditional box-moxibustion on capillary blood perfusion in the body surface. Methods: Twenty healthy subjects, 18 females and 2 males, aged averagely 36 years, were enrolled in this experiment. The traditional box-moxibustion and electrothermal Bian-stone moxibustion were respectively given on the hypogastrium around Guanyuan (CV 4), and the changes of local capillary blood perfusion in the body surface were investigated with Laser Doppler Perfusion Imaging (LDPI). Results:The traditional box-moxibustion was superior to the electrothermal Bian-stone moxibustion in the transient increasing effect in whole body and the long-term increasing effect in the local area of moxibustion on capillary blood perfusion; but for both methods, the increasing effect on the capillary blood perfusion in the local area of moxibustion was same. Conclusion: Electrothermal Bian-stone moxibustion can not completely take the place of the traditional box-moxibustion; but for some disorders with local pain, they possibly have the same effects.