To study the mechanism of unsteady heat-moisture transfer of wet surrounding rock in deep mining, a series of experiments with different initial and boundary conditions were carried out. Test results show that rock te...To study the mechanism of unsteady heat-moisture transfer of wet surrounding rock in deep mining, a series of experiments with different initial and boundary conditions were carried out. Test results show that rock temperature decreases quickly at the initial stage, and reduces slowly to be a constant value finally for transient heat-moisture transfer. The quasi-steady surface temperature of wet airway is lower than that of dry airway due to the moisture transfer. The diffusion radius is less than the cooling radius owing to the large diffusion resistance. The outlet airflow enthalpy of wet airway is much larger than that of dry airway. Latent heat caused by the moisture transfer plays a significant role in a deep thermal environment. For periodic heat-moisture transfer, temperature, humidity and enthalpy of outlet airflow and rock temperature also change periodically. The wave amplitude of rock temperature decreases gradually with increasing distance away from the airway surface, and the wave phase of rock temperature is also behind that of airflow. Moreover, direction of the heat-moisture transfer between airway and airflow is bidirectional, which is different from results of transient transfer.展开更多
The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried ou...The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried out to study'pull-down'and steady-state performance of the RF,and to determine how the experiment and simulation temperature stack up against each other.Good match is found between simulated and measured results for the'pull-down'period.For the steady-state period,the simulation results are also found to agree well with experiment ones except for the temperature profiles of the refrigerator compartment(RC) and freezer compartment(FC).The average temperature and the energy consumption errors between measurement and simulation are less than 10%.Although the model can not reflect the non-uniform air temperature fields in the RC and FC,the variation range and periodicities of the temperature correlate well between the simulation and experiment.We conclude that such a model is valid for investigating the performance of no-frost refrigerator.展开更多
基金Foundation item： Project（2012CB026103） supported by the National Basic Research Program of China Project（51204170） supported by the National Natural Science Foundation of China+2 种基金 Project（2011M500974） supported by Postdoctoral Science Foundation of China Project （2011QNA16） supported by Fundamental Research Funds for the Central Universities, China Project（PDll01） supported by Postdoctoral Foundation of State Key Laboratory for Geomechanics and Deep Underground Engineering, China
文摘To study the mechanism of unsteady heat-moisture transfer of wet surrounding rock in deep mining, a series of experiments with different initial and boundary conditions were carried out. Test results show that rock temperature decreases quickly at the initial stage, and reduces slowly to be a constant value finally for transient heat-moisture transfer. The quasi-steady surface temperature of wet airway is lower than that of dry airway due to the moisture transfer. The diffusion radius is less than the cooling radius owing to the large diffusion resistance. The outlet airflow enthalpy of wet airway is much larger than that of dry airway. Latent heat caused by the moisture transfer plays a significant role in a deep thermal environment. For periodic heat-moisture transfer, temperature, humidity and enthalpy of outlet airflow and rock temperature also change periodically. The wave amplitude of rock temperature decreases gradually with increasing distance away from the airway surface, and the wave phase of rock temperature is also behind that of airflow. Moreover, direction of the heat-moisture transfer between airway and airflow is bidirectional, which is different from results of transient transfer.
文摘The methodology for modeling no-frost refrigerator is described based on the component models developed in PartⅠ,and then,system simulation is applied to a BCD-235W refrigerator-freezer(RF).Experiments are carried out to study'pull-down'and steady-state performance of the RF,and to determine how the experiment and simulation temperature stack up against each other.Good match is found between simulated and measured results for the'pull-down'period.For the steady-state period,the simulation results are also found to agree well with experiment ones except for the temperature profiles of the refrigerator compartment(RC) and freezer compartment(FC).The average temperature and the energy consumption errors between measurement and simulation are less than 10%.Although the model can not reflect the non-uniform air temperature fields in the RC and FC,the variation range and periodicities of the temperature correlate well between the simulation and experiment.We conclude that such a model is valid for investigating the performance of no-frost refrigerator.
