最新刊期
卷 28 ， 期 3 ， 2007
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Experimental Investigation on Pressure Drop of R22 and R410a during Condensing Process in Microtubes
摘要：R410a is known as one of the substitutes for R22 and it is important to study the pressure drop of R410a during condensing processes. A test rig was established to measure pressure drop in micro scale and characteristics of pressure drop of R22 and R410a in a horizontal stainless round tube with an inner diameter of O. 941 mm during condensing processes were investigated experimentally at the saturation temperature of 40%. The mass flux varied within the range of 200- 1000 kg/m^2 s and the vapor quality 0. 2- 0. 8. The experiment results indicate that pressure drop increases with mass flux and vapor quality and more obviously in high vapor quality region. The pressure drop of R410a is equivalent to that of R22 at low vapor quality and mass flux but obviously lower than that of R22 at higher vapor quality and mass flux.关键词：engineering thermophysics;Microtube;Condensation;Pressure drop;experimental investigation1722|375|0更新时间：2025-09-03 - 摘要：Performance tests were conducted on three finned tube evaporators, which included one untreated copper fin evaporator, two hydrophilic treated copper fin evaporators. Each evaporator was tested with it being installed in the indoor unit of a cabinet- type air conditioner, which was used as the platform of the performance tests. Tests were conducted using the calorimeter method under the different humidity air conditions. The results showed that the evaporator surface wettability has notable effect on the air conditioner performance at high humidity air conditions because of strong ability to discharging great dew water, not at low humidity air conditions because of less water condensate.1663|349|0更新时间：2025-09-03
- 摘要：Compound surfactants were added to aqueous LiBr solution in static pool setup to study their effect on water vapor absorption of aqueous LiBr solution. 1- Octanol, 2- Octanol, 2- Ethyl- 1 - hexanol, and 1 - Hexanol were added to 60w LiBr solution individually and in the mixture form of two surfactants. The experimental result shows that the effect of compound surfactants is near to the better one between them,for example, 1 - Octanol is the best one during these four additives, the effect of any other additive mixed with 1 - Octanol is near to the effect of 1 - Octanol alone.关键词：Engineering thermophysics;Absorption mass;Stagnant pool absorber;Surfactant;Aqueous LiBr solution1628|343|0更新时间：2025-09-03
- 摘要：Energy loss for a gas flowing inside a capillary tube was obtained experimentally. With data processing, the curves of the gas flow rate change with different lengths and inner diameters for the capillary tube were achieved. The gas flow rate change curves inside the capillary tube with the pressure difference were imitated.关键词：Power machinery and engineedng;Capillary tube gas flux speciality;Capillary tube gas flux distributing function;Curve imitate;DSP data processing;Refrigeration system matching;Capillary tube check up1681|354|0更新时间：2025-09-03
- 摘要：A regeneration tower with honeycomb paper to be its packed material was developed.Experiments were conducted to investigate the influence of air flow,solution temperature and height of packed material on its regeneration performance with the fixed inlet air states,solution concentration and flow rate.The experimental results indicate that the mass transfer increases when the solution temperature increases and MR decreases.In addition,The change of the mean Sherwood number at several heights of packed material was obtained.1657|346|0更新时间：2025-09-03
- 摘要：A regeneration tower with honeycomb paper to be its packed material was developed. Experiments were conducted to investigate the influence of air flow, solution temperature and height of packed material on its regeneration performance with the fixed inlet air states, solution concentration and flow rate. The experimental results indicate that the mass transfer increases when the solution temperature increases and MR decreases. In addition, The change of the mean Sherwood number at several heights of packed material was obtained.1496|352|0更新时间：2025-09-03
- 摘要：Considering the characteristics of linear grill which is widely used in vertical display cases, a two- fluid model for the air supply opening was set up. In the model the two fluids were defined as the original air in the display case and the inlet stream through the air curtains. The volume fraction of the inlet stream was defined as the area coefficient of linear grill. The mass transfer, momentum transfer, and energy transfer between two fluids were computed with empirical equations. The computational results show that the two- fluid model of air supply opening is in more agreement with the experiment than the conventional simple opening model.关键词：pyrology;Air supply opening model;Two- fluid model;air curtain;Display case1698|345|0更新时间：2025-09-03
- 摘要：The direct evaporative internal- melt ice storage air conditioning is a new and promising ice - storage technology. It has high heat transfer efficiency and hence can be widely used. Through adding ice storage tank and heat transfer tubes and the control valves, a split- type inverter air- conditioner was reconstructed as an evaporative internalmelt ice storage air conditioning system. In this study, the heat - transfer properties in the ice storage tank and dynamic characteristics of the system about the charging process and discharging process were studied and the performance curves of the both processes were obtained. Experimental results show that the power load shift rate of the experimental system can reach about 23%关键词：pyrology;Direct evaporative internal- melt ice storage system;Charging process;Discharging process;heat transfer;Dynamic characteristic1772|356|0更新时间：2025-09-03
- 摘要：Based on the corresponding principle, it is found that the relationship between saturated vapor corresponding - density and corresponding- temperature for mixtures accorded with that for pure- components. Moreover, a methed was obtained to calculate the critical density and critical pressure of refrigerant mixtures by using the critical density and critical pressure of pure- components and thus the characteristic parameters, the critical density and critical pressure of refrigerant mixtures, were achieved. Then the generalized equation that is implicit and used to calculate saturated vapor density of refrigerant mixtures was proposed. In addition, the values calculated were compared with the values in literature for five ternary and binary refrigerant mixtures and their deviation is less than 2%.关键词：pyrology;Saturated vapor density;Corresponding state;Refrigerant mixtures;Prediction1766|346|0更新时间：2025-09-03
- 摘要：A novel machine learning method,support vector machine(SVM),was used to develop a prediction model for frost growth on cold surface.The prediction model was validated by experimental data.The values predicted were compared with those by multivariable nonlinear regression(NLR) model which is based on the least square method,and the results show that the SVM based model has a good prediction accuracy.Then the SVM based total heat flux prediction model was investigated as an example in the capability of dealing white noise signal by adding noise in the input vectors and the output vector of the training set.The result shows that the present SVM prediction models are robust against noise.1634|339|0更新时间：2025-09-03
- 关键词：food processing technology;The time of sublimation vacuum freeze- drying;Scallop1738|350|0更新时间：2025-09-03
- 关键词：horticulture;vacuum cooling;air cooling;cold storage;Pakchoi1714|349|0更新时间：2025-09-03
- 摘要：A new formula for compressor current was proposed by revision of the conventional formula and a formula for the calculation of the compressor power efficiency was also proposed. A multiple non - linear mathematical method was used to achieve fitted coefficient. The average related errors between the experiment data and the fitted data are 1 .97% and 1. 503 %. The result shows that the present two calculation models can describe accurately the compressor performance and energy consumption for a whole series of scroll compressors.关键词：Power machinery and engineering;scroll compressor;Current;Power efficiency;Formula;Multiple nonlinear1585|354|0更新时间：2025-09-03
- 摘要：Based on the model of phase change heat conduction,an inverse problem method combining phase interface motion experiment and numerical calculation was developed to study the improvement of thermal conductivity when metal is added in PCMs(Phase Change Materials).The results show that the greater the thermal conductivity of metal,the higher the effective thermal conductivity of PCMs.It is indicated that when the added ratio of metal is the same,the improvement is greater for PCMs with low conductivity than that for PCMs with high conductivity.The results agree well with those in literature.关键词：Engineering thermophysics;PCMs;thermal conductivity;Inverse problem method1631|372|0更新时间：2025-09-03
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