Dropwise Condensation Heat Transfer Coefficient on the Horizontal Circular Surface with Radial Gradient Surface Energy     

GU Yang-biao  LIAO Qiang  ZHU Xun  WANG Hong 《保鲜与加工》2006,(5):48-51

A theoretical model is developed for the dropwise condensation heat transfer on the horizontal circular surface with radial gradient surface energy based on the heat transfer model of individual condensate drop and the size distribution model of condensate drop on homogeneous condensation surface.The effect of variation of contact angle on the gradient surface on condensation heat transfer and condensate drop size distribution is taken account of in this model.The theoretical calculation method was obtained to predict the dropwise condensation heat transfer coefficient on the horizontal circular surface with radial gradient surface energy under various wall subcooled temperature,contact angle profile on wall surface,and working fluid.The effects of surface energy gradient,wall subcooled temperature,and thermophysical properties of condensate on the condensation heat transfer are discussed respectively.The calculation results show that the condensation heat transfer coefficient increases slightly with the increase of wall subcooled temperature.As latent heat and surface tension increasing,the condensation heat transfer coefficient increases.A larger surface energy gradient induces a larger condensation heat transfer coefficient.  相似文献   

PREDICTIVE INTELLIGENT CONTROL OF THE COLD STORAGE     

Cao Changxiu Wang WanLiang 《保鲜与加工》1989,(5):68-75

The predictive intelligent control scheme is proposed, which is based on approximation theory and numerical method of Chcbyshev orthogonal polynomial. It has the practical value to the cold storge using widely electromagnetic valve and can be also applied similar systems in orther area.  相似文献   

Optimization of Energy Dissipation Braces in Frame Structures     

WU Ze hou  ZHOU Fu lin 《保鲜与加工》2002,(2):47

In this paper, the complex method of the nonlinear programming is used to optimize the parameters of energy dissipation bracing in energy dissipation braced frame. This method is realized with computer program and proved to be efficient. A 6-story reinforced concrete frame is used as a demonstrative example.  相似文献   

Land Storage System: Effect, Problem and Its Legal Regulation     

HUANG Xi-sheng~  TANG Shao-jun~  WANG Bao-xin~ 《保鲜与加工》2004,(2)

The authors suggest that the land storage system is beneficial not only to strengthen the country's macroscopic regulation of city land market, accelerate healthy development of city economy and increase the financial income, it can also be advantageous to carry out the economic reform and public facilities construction without a hitch. On the basis of this, in this paper, the increment of the land price and house price as well as the high risk of fund due to lack of related laws is analyzed. Corresponding legal regulations, such as polishing the legislation of land right, implementing the land utilization planning, reinforcing the legislation of city development, land requisition and countryside residential land administration are put forward.  相似文献   

Pinning Theory of Fermi Energy and Surface State Measurement of ZnSnO3 Gas Sensitive Material     

LI Ji  LIU Tian-mo  ZHAO Xian-rui  WANG Zhong-chang  LI Jia-ming 《保鲜与加工》2006,(5):55-58

In order to research the state of energy bands and gain and loss of electrons on the surface of ZnSnO_(3),it is put forward that Pinning theory of Fermi energy is applied to development of gas sensitive materials.The relative position between surface state and conduction band on surface of zinc tin complex oxide(ZnSnO_(3)) gas sensitive material has been investigated by utilizing oxidation redox couple,FeCl_(2)/ FeCl_(3),which have high surface state.Fermi energy is pinned at about 0.2 eV below conduction band E_(cs)on the surface of ZnSnO_(3).It has been determined that additives doping ratio,addition concentration and working atmosphere have no effect on this value.Therefore,pinning theory of Fermi energy has been verified by using this method.  相似文献   

A Thermodynamic Criteria for Evaluation of Heat Exchanger Performance     

Li Yourong Jin Mingcong Tang Jingwen 《保鲜与加工》1993,(6):46-50

The concept of loss rate of available energy was introduced for evaluating heat exchanger performance. At the same time, the general expression of loss rate of available energy was obtained for heat exchangers of several typical. And NL criteria was recommended for evaluation of the loss rate of available energy of heat exchanger. Then. the influences of inlet temperatures ratio, heat capacity ratio of fluids, the number of heat transfer units and flow patterns of heat exchanger on ,VL criteria were also discussed.  相似文献   

Energy Assessement for Procedure Rationality of Recycling Materials from Wastes     

Liu Jianglong  Ding Peidao 《保鲜与加工》1996,(2):122-126

The mathematical relationship for assessing total energy consumption within a material life cycle is presented in this paper. According to the relationship,the procedure rationality of recycling waste may be assessed quantitatively.  相似文献   

THE SIZE EFFECT OF THE FRACTURE ENERGY OF CONCRETE TESTED BY THREE POINT BENDING     

Qian Jueshi  Fan Yingru  Yuan Jiang 《保鲜与加工》1995,(2):1-8

This paper ainalyses the size effect of the fracture energy of concrete tested bythree point bending. It is shown that positive errors of test results of fracture energy increase,ornegative errors decrease with increasing of the specimen ize. The phenomenon is one of main causesresulting in the size effect of fracture energy.  相似文献   

Energy Efficiency Analysis of Heating System in the Birdhouse     

HUANG Yong  FU Xiang- zhao 《保鲜与加工》2006,(3):93-95101

In this paper the problem of energy consumption and environment in the birdhouse is introduced and the reconstructive measures aiming at energy savings are recommended. The measures include the limitation of temperature region, reconstruction of the building envelop and using the sunny board at the south side of the birdhouse roof. Finally, the energy efficiency of the reconstructive project is estimated.  相似文献   

Optimum Planting System for Energy Saving and Healthy Demanded     

BAI Xue lian 《保鲜与加工》2002,(8):77

It is proved that planting is effective to improve environment both indoor and outdoor resulted from the functions of plants to clean air and save energy. So the contradiction between saving energy and comfort,healthy demanded by people can be solved by planting. The planting have being emphasized and expanded during recent years,but in the planting plan,just the function of beautifying the environment is concerned and the function of ecological and saving energy are neglected. The analysis on the ooptimum system of planting is to make the planting system as an organic composition in the effectiveness structure and space layout of the city. Based on the study on equivalent relation of different effects on environment, the optimum system of planting structure will be determined in order to achieve the integrated effects of planting on environment.  相似文献