最新刊期

    33 4 2012
    • Yu Nan, Wang Ruzhu, Li Tingxian, Xu Lv
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.001
      摘要:A double-effect and double-way thermochemical sorption refrigeration system was set up. In the system, adsorption refrigeration, resorption refrigeration and internal heat recovery technologies were used to improve system performance. The feasibility and working performance of the proposed system was experimentally investigated. Experimental results showed that the present double-effect and double-way thermochemical sorption refrigeration cycle was feasible in the field of refrigeration and air conditioning. In one cycle, four cold productions were achieved at the expense of only one heat input. When NiCl2-MnCl2-BaCl2 -NH3 was employed as a group of sorption working pair, the obtained COP was as high as 1.1 at the desorption temperature of 265℃, the heat sink temperature of 30℃, and the refrigeration temperature of 15℃. Moreover, cooling power evolution of four cold output processes was analyzed and it was found that the resorption reaction is stronger than adsorption reaction.  
      关键词:pyrology;sorption refrigeration;double-effect;double-way;reaction conversion   
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      发布时间:2024-07-30
    • Tong Huan, Luo Ercang
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.002
      摘要:The paper proposes a novel thermoacoustic heat pump and uses the DeltaEc code to simulate the thermodynamic performance of a double-acting traveling-wave thermoacoustic heat pump for high-temperature range. The influence of different dimensions of each thermodynamic component is analyzed when the inlet and outlet volume flow rates are kept at a phase difference of 120°. Based on the analysis and discussion of these influences, this article designs and optimizes a high-performance heat pump. When the hot end is kept at a temperature of 100℃ and the ambient temperature of 30℃, the heat pump can achieve pumping power of 1037.7W, a COP of 3.2 and a relative Carnot efficiency of 59.7%. Furthermore, the study shows that the relative Carnot efficiency can reach a highest Carnot efficiency of 60.1% if the inlet phase of inlet volume flow rate leading the outlet volume flow rate by 129°.  
      关键词:pyrology;double-acting;high-temperature heat pump;thermoacoustic conversion;traveling-wave   
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      发布时间:2024-07-30
    • Wang Fenghao, Yan Liang, Feng Chenchen, Wang Xinke
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.003
      摘要:A three dimensional numerical model of ground source heat pump system was established. The effects of testing time, starting time, borehole radius, initial ground temperature and heat injection rate on identified thermal conductivity of the deep ground soil were analyzed based on the numerical model. The simulation results showed that thermal response test time should be more than 70 h; For cylinder-source model, with the increase of the size of the borehole, the identified thermal conductivity gradually decreased; The initial temperature of ground soil has no effect on the result of thermal conductivity identification, but the testing precision of the initial temperature has larger effects to identification results when the parameter estimation method is adopted; For pure thermal conductivity model, heat injection rate has no effect on thermal conductivity identification results.  
      关键词:engineering thermophysics;ground source heat pump;thermal response test;influencing factor;numerical simulation   
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      发布时间:2024-07-30
    • Lin Enxin, Ding Guoliang, Hu Haitao, Zhao Dan
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.004
      摘要:When compressor starts and doesn’t reach stable, the two phase refrigerant mass calculation should consider the affection of non-linear quality distribution. A novel refrigerant mass calculation method for phase-lumped air cooled heat exchanger model is proposed. Firstly, the refrigerant quality distribution is predicted based on distributed heat exchanger model, then the dimensionless length of arbitrary point for two phase zone is introduced to describe the point of two phase zone; and then the refrigerant quality with the dimensionless length is fitted in polynomial; lastly, the mean void fraction for predicting two-phase refrigerant mass is described. When the refrigerant quality distribution is nearly linear, the difference of predicted refrigerant mass between the novel model and the existed model is small. When the refrigerant quality distribution is intensively non-linear, comparing with the existed two-phase refrigerant mass calculation model based on linear quality distribution, the novel two-phase refrigerant mass calculation model can decrease mean deviation and max deviation respectively to the 59% and 55% of the original ones, while the calculation speeds of these two models are similar.  
      关键词:engineering thermophysics;two phase;real quality distribution;refrigerant mass;phase-lumped heat exchanger model   
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      发布时间:2024-07-30
    • Chen Zhenming, Xie Lichang
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.005
      摘要:CFD tool was applied in the design of the rotary compressor, such as optimization of resonant-chamber, in-flow in the shell of the compressor, oil supply system and feeding of lubricant oil in the compressor. The CFD simulation results were validated by the experiment ones. It is shown that applying the CFD tool during the design of the rotary compressor could profoundly find out the characteristics about the compressor, and could direct the design, and save cost and time.  
      关键词:pyrology;CFD;rotary compressor;resonant-chamber;oil feed   
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      发布时间:2024-07-30
    • Yu Nan, Zhao Dan, Ding Guoliang, Hu Haitao
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.035
      摘要:In order to simulate different types of refrigerators under the same platform, an integrated simulation platform for multi-type refrigerators is introduced. Firstly, the general model for compressor, heat exchanger and cabinet is built separately, and then the method of data interaction and integration of system control algorithm is put forward. The experimental validation results show that the integrated simulation platform for multi-type refrigerators is able to simulate the commonly-used types of refrigerators, and the deviations of energy consumption and on-off ratio are within 10%.  
      关键词:pyrology;refrigerator;multi-type;simulation;model   
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      发布时间:2024-07-30
    • Yu Nan, Zhao Dan, Ding Guoliang, Hu Haitao
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.006
      摘要:In order to simulate different types of refrigerators under the same platform, an integrated simulation platform for multi-type refrigerators is introduced. Firstly, the general model for compressor, heat exchanger and cabinet is built separately, and then the method of data interaction and integration of system control algorithm is put forward. The experimental validation results show that the integrated simulation platform for multi-type refrigerators is able to simulate the commonly-used types of refrigerators, and the deviations of energy consumption and on-off ratio are within 10%.  
      关键词:pyrology;refrigerator;multi-type;simulation;model   
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      发布时间:2024-07-30
    • Chen Shuping, Yao Shuting, Xie Fushou, Han Hongyin
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.007
      摘要:A model of frost formation and growth on the cryogenic surface of finned-tube vaporizer was proposed based on Diffusion Limited Aggregation (DLA) model, and through controlling the times of program running, the simulation on the different stages of frost formation and growth on the cryogenic surface was carried out in this paper. Combined with frost formation and growth on the cryogenic surface obtained by experimental observations, the rationality of numerical simulation was verified from fractal dimension and frost layer density. The result shows that frost layer density decreases with the increase of thickness in the early frosting stage as initial frost dendrite constantly grows branch crystal, and the fractal dimension of frost layer on the cryogenic surface is larger than the fractal dimension of frost layer on the general cold surface. The frost growth on the cryogenic surface is more complex, and it has a bigger ability of filling space. This investigation is significant to further understand the frosting mechanism on the surface of cryogenic finned-tube vaporizer, explore the effective defrosting methods, and enhance heat transfer characteristics of the vaporizer.  
      关键词:engineering thermophysics;finned-tube vaporizer;fractal;numerical simulation   
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      发布时间:2024-07-30
    • Wang Haisong, Zhou Xinli, Li Weijie
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.008
      摘要:The Cryotop is an efficient vitrification method for cryopreservation of oocytes. It has been widely used owing to its simple operation and high freezing rates. Recently, its heat transfer performance is frequently studied by the way of numerical simulation. However, the range of heat transfer coefficient in the simulation is uncertain. Three kinds of Cryotop models with different board thickness were studied. The cooling rates of water droplets in freezing process of Cryotop were measured by ultra-fast measurement and calculated by numerical simulation. Comparing the results obtained by two methods, the range of the heat transfer coefficient which was needed in the numerical simulation of Cryotop was found. The result showed that the range of the heat transfer coefficient is 6000~8000 W/(m2.K).  
      关键词:pyrology;Cryotop;heat transfer coefficient;ultra-fast temperature measurement;numerical simulation   
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      发布时间:2024-07-30
    • Ma Min, Huang Bo, Geng Wei, Zhu Fuxiang
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.009
      摘要:The paper introduces the design of vapor-injection rotary compressor. Compared to the conventional system, a heat pump system with the vapor-injection rotary compressor has been developed and tested under several conditions. The vapor-injected rotary compressor has been tested with the system of flash tank and internal heat exchanger. The vapor-injected rotary compressor has also been tested compare to the vapor-injected scroll compressor under the same conditions. The results show that when the outdoor temperature decreases, the heating capacity increasing ratio of the vapor-injection rotary compressor is enlarged. The system with flash tank has a better heating capacity compared to the internal heat exchanger. The vapor-injection rotary compressor can effectively increase the heating capacity by 18% for low ambient heating application, and has a comparable performance with scroll compressor.  
      关键词:thermal engineering;rotary compressor;enhanced vapor-injection;economizer   
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      发布时间:2024-07-30
    • Liu Lianjun, Xu Haifeng, Hao Baotong, Tang Linli, Liu Baolin
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.010
      摘要:To study the effects of the nanoparticles on thermodynamic parameter of cryoprotectant solutions, the specific heat of the glycerol solutions (50% v/v) with/without nanoparticiles (HA) was measured by using DSC. The results show that specific heat of the glycerol solutions has decreased slightly, when the mass fraction of nanoparticles is 0.1%. While specific heat of the glycerol solutions has decreased obviously, when the mass fraction of nanoparticles is 0.5%. Because the specific heat is inverse to the thermal diffusivity, the less the specific heat is, the farther the cooling rate is. This paper provides a theoretical explanation about it.  
      关键词:engineering thermophysics;DSC;specific heat;nanoparticles;cryoprotectant solutions   
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      发布时间:2024-07-30
    • Li Kuining, Li Jin, Guo Junfeng, Liu Bin
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.011
      摘要:Based on the thermal equilibrium equation of vehicle envelope considering the impact of external heat radiation, the Newton iteration method was used to calculate both the envelope temperature and the heat flux through the envelope in the idling working condition. Then, a complete thermal load calculation model of vehicle in idling condition was proposed by measuring the body wall temperature of the engine compartment and the trunk and the amount of air leakage. Finally, the thermal load of objective car which was calculated by the new model was compared with the experimental values which were tested in an environmental simulation laboratory. The results showed that the relative errors are within ± 8%, which indicated that the thermal load model was reasonable and accurate in the idling working condition, which could meet requirements of engineering application.  
      关键词:pyrology;car passenger compartment;idling working condition;air leakage;thermal load   
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      发布时间:2024-07-30
    • Zhou Xinli, Yuan Ji, Wang Haisong, Li Weijie
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.012
      摘要:Optimization of human red blood cells (RBCs) cryopreservation protocols requires an understanding of the water permeability characteristics. Volume shrinkage during freezing of RBCs can be obtained by using a shape-independent differential scanning calorimeter (DSC) technique. By ?tting the water transport model to the experimentally obtained DSC data, the best-?t membrane permeability parameters (reference membrane permeability to water and the activation energy) in normal saline, 20 % dimethyl sulfoxide (Me2SO), 10% glycerol and 20% glycerol were determined. These parameters were then used to simulate water transport of RBCs at constant cooling rates between 0.5~50℃/min. The simulation results showed “optimal cooling rate” for erythrocytes were 5.2℃/min, 5.5℃/min and 4.6℃/min in 20 % Me2SO, 10% and 20% glycerol respectively.  
      关键词:pyrology;permeability parameters;optimal cooling rate;DSC;red blood cell   
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      发布时间:2024-07-30
    • Qin Haijie, Liu Jinglin, Sun Ming
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.013
      摘要:This paper found the freezing point of multiple secondary refrigerant for immersion chilling and freezing by the experiment. The refrigerant consists of ethanol, sodium chloride and water. The mutual influence of each component as well as glucose and protein as an additive to the freezing point of the mixed solution was analyzed. The results showed that suitable composition of multiple secondary refrigerant used in different temperature range for ICF are as follows: above -20℃: Ethanol concentration 5%~15% and sodium chloride concentration 5%~20%; between -20℃ to -30℃: Ethanol concentration 23%~25% and sodium chloride concentration 14%~18%; between -30℃ to -40℃: Ethanol concentration 37%~40% and sodium chloride concentration 12%~14%; between -40℃ to -46℃: Ethanol concentration 40%~55% and sodium chloride concentration 9%~12%. Sodium chloride reduced the freezing point of ethanol solution and ethanol lowered the freezing point of sodium chloride solution. The saturation of sodium chloride on ethanol solution decreased with the increasing of the ethanol concentration. Aqueous protein reduced 1~2℃ freezing point of mixture solution, but the effect of glucose on freezing point of mixture solution was not obvious.  
      关键词:engineering thermophysics;immersion chilling and freezing;secondary refrigerant;freezing point   
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      发布时间:2024-07-30
    • Peng Fuyu, Xu Yi, Zhao Xiaogang, Liu Daoping, Zhong Yanqian
      Vol. 33, Issue 4, (2012) DOI: 10.3969/j.issn.0253-4339.2012.04.014
      摘要:For the requirements of lung preservation with low temperature in situ, a rapid cooling and preservative system was developed. By the way of bronchus and thorax, the temperature of donor lung would be reduced respectively with cooling gas and cooling water. The experimental results showed that the cooling effect would be better in the areas closer to the entrance of the trachea with cooling gas and there was nearly no effect in the end of bronchus. With cooling fluid, the cooling effect was satisfied both in the surface and internal area except some potential mechanical damage for lung tissue.  
      关键词:pyrology;semiconductor refrigeration;rapid cooling;cooling preservation in situ;non-heart-beating donors   
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      发布时间:2024-07-30
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