In order to control the heat saturation time, the temperature field of the regenerators of high temperature air combustion （HTAC） technology after reheating furnace was studied. A one-dimensional unsteady mathematic...In order to control the heat saturation time, the temperature field of the regenerators of high temperature air combustion （HTAC） technology after reheating furnace was studied. A one-dimensional unsteady mathematical model was established and discretized through finite difference method. The relationship between the heat saturation time and some factors was determined through the calculation of a program developed by language C. The heat saturation time decreases with the increase of heat convection coefficient, however, the increase of heat capacity, density and radius of regenerator all increase the heat saturation time approximately linearly.展开更多
Saturated vapor pressure, critical evaporation temperature and evaporation loss rate of Fe-Ga alloy were calculated under different conditions of Ga and Fe contents with activity coefficients. The relationship between...Saturated vapor pressure, critical evaporation temperature and evaporation loss rate of Fe-Ga alloy were calculated under different conditions of Ga and Fe contents with activity coefficients. The relationship between the change of Ga content and melting time was determined. The results demonstrated that saturated vapor pressure of Ga was higher than that of Fe under the same conditions. The difference value of critical evaporation temperature of Ga with and without Ar was nearly 800 K. The critical evaporation temperature of Fe was higher than that of Ga under vacuum, indicating that Ga was more volatile than Fe. At 1800 K, the evaporation rate of Ga was 84 times higher than that of Fe in the melt of Fe81Ga19 alloy. Under this condition, the change of Ga content and smelting time kept a linear relationship. The higher the temperature was, the faster the Ga content decreased, which was consistent with theoretical calculations.展开更多
In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of rege...In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of regenerator and gas were obtained. The variation of temperature with time was discussed. In addition, the effects of some parameters such as switching time, gas temperature at the inlet of regenerator, height of regenerator and specific heat of the regenerative materials on heat saturating time were discussed. It provided primarily theoretic basis for further study of regenerative heat transfer mechanism.展开更多
Due to the wide application of floor heating systems, the radiant floor cooling systems has developed rapidly in recent years. In this paper, TRNSYS numerical simulation methods are used to study the influence of chil...Due to the wide application of floor heating systems, the radiant floor cooling systems has developed rapidly in recent years. In this paper, TRNSYS numerical simulation methods are used to study the influence of chilled water supply temperature and flow rate on the cold storage characteristics of a standard floor structure for office buildings in northern China. The results are verified by experimental measurements. The functional relationship between the saturated cold storage time and the chilled water flow rate is quadratic polynomial, while the changes of supply-water temperature have no effect on the saturation time;the supply-water temperature has a linear relationship with the saturated cold storage volume, while the chilled water flow rate has almost no effect on the saturation cold storage volume. The accumulated cold volume of floor changes with time in an exponential distribution with four coefficients, and the floor has the characteristics of rapid cold storage. This paper is instructive for the design, application and promotion of radiant floor cooling systems.展开更多
文摘In order to control the heat saturation time, the temperature field of the regenerators of high temperature air combustion （HTAC） technology after reheating furnace was studied. A one-dimensional unsteady mathematical model was established and discretized through finite difference method. The relationship between the heat saturation time and some factors was determined through the calculation of a program developed by language C. The heat saturation time decreases with the increase of heat convection coefficient, however, the increase of heat capacity, density and radius of regenerator all increase the heat saturation time approximately linearly.
基金Item Sponsored by National Natural Science Foundation of China(51161019)Project of Department of Science and Technology of Jiangxi Province of China(20133BBE50011)Project of Department of Science & Technology of Jiangxi Province of China(20141BDH80025)
文摘Saturated vapor pressure, critical evaporation temperature and evaporation loss rate of Fe-Ga alloy were calculated under different conditions of Ga and Fe contents with activity coefficients. The relationship between the change of Ga content and melting time was determined. The results demonstrated that saturated vapor pressure of Ga was higher than that of Fe under the same conditions. The difference value of critical evaporation temperature of Ga with and without Ar was nearly 800 K. The critical evaporation temperature of Fe was higher than that of Ga under vacuum, indicating that Ga was more volatile than Fe. At 1800 K, the evaporation rate of Ga was 84 times higher than that of Fe in the melt of Fe81Ga19 alloy. Under this condition, the change of Ga content and smelting time kept a linear relationship. The higher the temperature was, the faster the Ga content decreased, which was consistent with theoretical calculations.
基金The research is supported by National Natural Science Foundation of China （No.50276002）.
文摘In this paper, heat transfer of the ceramic honeycomb regenerator was numerically simulated based on the computational fluid dynamics numerical analysis software CFX5. The longitudinal temperature distribution of regenerator and gas were obtained. The variation of temperature with time was discussed. In addition, the effects of some parameters such as switching time, gas temperature at the inlet of regenerator, height of regenerator and specific heat of the regenerative materials on heat saturating time were discussed. It provided primarily theoretic basis for further study of regenerative heat transfer mechanism.
基金financially supported by the Plan of Guidance and Cultivation for Young Innovative Talents of Shandong Provincial Colleges and Universitiesfinancially supported by the National Natural Science Foundation of China(Grant No.51808321)。
文摘Due to the wide application of floor heating systems, the radiant floor cooling systems has developed rapidly in recent years. In this paper, TRNSYS numerical simulation methods are used to study the influence of chilled water supply temperature and flow rate on the cold storage characteristics of a standard floor structure for office buildings in northern China. The results are verified by experimental measurements. The functional relationship between the saturated cold storage time and the chilled water flow rate is quadratic polynomial, while the changes of supply-water temperature have no effect on the saturation time;the supply-water temperature has a linear relationship with the saturated cold storage volume, while the chilled water flow rate has almost no effect on the saturation cold storage volume. The accumulated cold volume of floor changes with time in an exponential distribution with four coefficients, and the floor has the characteristics of rapid cold storage. This paper is instructive for the design, application and promotion of radiant floor cooling systems.
