共查询到19条相似文献,搜索用时 93 毫秒
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氢气作为热泵干燥装置干燥介质的分析 总被引:1,自引:0,他引:1
分析了氢气作为热泵干燥装置干燥介质时,干燥介质与物料的对流换热系数、对流传质系数、干燥介质的流动阻力、单位体积干燥介质与水蒸气的饱和混合物中的水蒸气量、单位体积干燥介质在绝热干燥过程中的最大水蒸气吸收量等特性,并与空气作为干燥介质时进行了对比,为氢气型热泵干燥装置的开发提供了较好的参考. 相似文献
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在简要介绍热泵干燥装置基本结构和工作原理的基础上,对热泵干燥装置的特点、市场拓展、应用与推广中的主要问题和解决思路、技术发展等进行了较全面的分析,为科学地把握和应用热泵干燥技术提供了较好的参考。 相似文献
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给出了一种兼具干燥、浓缩、冷却、速冻、解冻、为其他工艺环节供冷及供热等功能的多功能热泵干燥装置,简要介绍了其各项功能的实现方式,并以干燥功能为例,就其干燥温度、干燥速度、能耗、综合经济性等与电加热式干燥装置进行了对比分析. 相似文献
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热泵干燥具有节能、低温干燥及环境友好等特点,控制热泵干燥装置运行在较佳的状态,是保证热泵干燥装置效率和可靠性的基础。以带循环空气旁通的封闭式热泵,干燥装置为例,对热泵干燥装置的调控方法进行了分析,给出了装置的被控参数和一组较佳的控制参数,并建立了各控制参数的计算公式。 相似文献
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Effects of Component Arrangement and Ambient and Drying Conditions on the Performance of Heat Pump Dryers 总被引:4,自引:0,他引:4
Performances of five heat pump dryer (HPD) configurations were studied by computer simulation. The component arrangement covers the fully open, the partially open, and the fully closed systems with external condenser or external cooler. The HPD performance was investigated for high and low drying rate and within the ambient temperature range of 20°C to 40°C. The best operating mode of the HPD depends on both drying rate and ambient condition. For the case of tropical climate and high drying rate, the partially open system is the optimum operating mode in general, except at some particular conditions where the fully open and fully closed systems are recommended. However, the operation for the low drying rate is more complicated, as the optimum configuration is sensitive to the change of ambient temperature. 相似文献
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《Drying Technology》2013,31(7):1603-1620
Abstract Drying kinetics of tomato was studied by using heat pump dryer (HPD) and electric resistance dryers with parallel and crossed airflow. The performance of both systems was evaluated and compared and the influence of temperature, air velocity, and tomato type on the drying kinetics was analyzed. The use of HPD showed to be adequate in the drying process of tomatoes, mainly in relation to the conversion rate of electric energy into thermal energy. The heat pump effective coefficient of performance (COPHT,EF) was between 2.56 and 2.68, with an energy economy of about 40% when compared to the drying system with electric resistance. The Page model could be used to predict drying time of tomato and statistical analysis showed that the model parameters were mainly affected by drying temperature. 相似文献
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Drying kinetics of tomato was studied by using heat pump dryer (HPD) and electric resistance dryers with parallel and crossed airflow. The performance of both systems was evaluated and compared and the influence of temperature, air velocity, and tomato type on the drying kinetics was analyzed. The use of HPD showed to be adequate in the drying process of tomatoes, mainly in relation to the conversion rate of electric energy into thermal energy. The heat pump effective coefficient of performance (COPHT,EF) was between 2.56 and 2.68, with an energy economy of about 40% when compared to the drying system with electric resistance. The Page model could be used to predict drying time of tomato and statistical analysis showed that the model parameters were mainly affected by drying temperature. 相似文献
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Heat pump–assisted dryers are an alternative method for drying heat-sensitive food products at low temperature and less relative humidity with lower energy consumption. The mathematical models of a heat pump dryer consist of three submodels; namely, drying models, heat pump models, and performance models. Heat and mass balance of both refrigerant and air circuits in all components of the system are used for development of mathematical models. The models are used for design of different components of heat pump dryers operating under constant drying rate condition. A simple stepwise design procedure for batch-type, closed-loop heat pump dryer is also presented. 相似文献
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The heat pump dryer with CO2 as the working medium is investigated in this study. The drying systems were designed based on the thermophysical properties and characteristics of CO2 cycle. The two-stage drying of CO2 transcritical cycle heat pumps are presented and discussed in comparison with the single compression cycle single-stage heat pump dryer, the two-stage drying heat pumps, and electric drying system. The analysis indicates that the specific moisture extraction ratio of the two-stage drying system can be higher than that of the single drying CO2 system. The efficiency of energy utilization of the CO2 heat pump dryer was higher than that of an electric dryer. 相似文献
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In this study, exergy and exergoeconomic analyses of a heat pump tumbler dryer are carried out by using actual thermodynamic and cost data. The wet cotton fabric is used as the test drying material. The results show that the specific moisture extraction rate (SMER) and evaporation rate of dryer are equal to 1.08 kg/kWh and 0.018 kg/s, respectively. Also, the respective exergetic efficiencies of the heat pump and overall system are equal to 0.07 and 0.11. A parametric study is then conducted in order to investigate the system performance and costs of the components, depending on the operating temperature and mass flow rate of air. 相似文献