一种多功能热泵干燥装置及其特性分析

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.     

膏状物料热泵厢式干燥的传热方案分析

介绍了一种干燥膏状热敏物料的相对较新的低温干燥方法———热泵厢式干燥,并提出了干燥该类物料的两种传热方案:对流传热方案和导热对流联合传热方案。通过典型参数计算分析了两个方案的特性,结果表明第二种传热方案在保证干燥质量的前提下,可以明显地缩短干燥时间,提高干燥效率。     

热泵干燥装置在生物物料干燥中的应用分析

干燥是食品、药品及生物活性制品生产的基本环节之一。就热泵与生物物料干燥装置相结合 ,提高干燥过程的热效率 ,降低生物物料在干燥过程中的质量损失进行了较深入的分析 ,同时也对热泵干燥装置应用与推广需进一步解决的问题及其应用策略进行了剖析。     

热泵型空气吸湿式膜蒸馏组件再生干燥装置的特性分析

热泵型空气吸湿式膜蒸馏组件再生干燥装置具有再生干燥速度较快、能耗低、无废气排放等特点。在简要介绍其工作原理的基础上,利用其特性方程,对膜蒸馏组件再生干燥速度、空气出加热器温度、出膜组件温度、出冷却器温度、耗电功率随循环空气流量的变化规律进行了计算分析,可为装置的设计和调控提供参考。     

内加热式热泵干燥装置的设计

内加热式热泵干燥装置通过导热加热方式提供物料中水分气化所需热能,可获得较高的能源效率和除湿能耗比。在介绍内加热式热泵干燥装置基本结构和工作过程的基础上,给出了其物料衡算、能量衡算和主要部件选型参数的计算公式,为内加热式热泵干燥装置的设计提供了较好的参考。     

热泵干燥装置操作参数的分析

分析了热泵干燥装置的独立操作参数,给出了热泵的蒸发温度、冷凝温度、干燥器进口空气的速度、干燥器出口空气的温度及相对湿度与热泵干燥装置除湿能耗比之间的关系式,计算了除湿能耗比随独立操作参数的变化规律,相关结论为热泵干燥装置测控系统的开发提供了较好的参考。     

膜蒸馏组件再生干燥装置的技术方案分析

介绍了真空干燥箱式、电热型空气吸湿式、热泵型空气吸湿式、溶剂吸湿式膜蒸馏组件再生干燥装置的构成、工作过程及其特点,并从再生时间、再生能耗、装置费用、环境污染及操作复杂性等方面对四种装置进行了综合比较,结果表明热泵型空气吸湿式膜蒸馏组件再生干燥装置具有较好的综合优势。     

气体干燥技术及装置

概括了一些传统气体干燥方法和装置及其最新进展,并比较其优缺点,适用范围。在此基础上,介绍一些新兴气体干燥技术及其工作原理,包括膜法除湿、热泵除湿、热电冷凝除湿和电化除湿。     

热泵干燥装置中干燥介质的物性及其应用分析

在热泵干燥装置中,干燥介质对干燥过程的传热传质速率、物料干燥质量和装置的能源效率均具有重要影响。给出了空气、氮气、二氧化碳、氩气、氢气、氦气六种干燥介质的热物性数据及其计算方程,并分析了其适宜的应用场合,为热泵干燥装置中选择适宜的干燥介质提供了较好的参考。     

热泵干燥装置的特性方程及其应用分析

以应用最广泛的封闭式热泵干燥装置为例,建立了其SMER计算方程。在此基础上,对SMER随干燥器进口空气温度、干燥器出口空气温度和蒸发器出口空气温度而变化的规律进行了计算和分析。结果表明,其他两个参数一定时,SMER随干燥器出口空气温度上升而降低,随蒸发器出口空气温度上升而增加,但当干燥器进口空气温度取适宜值时,SMER存在最大值。     

传导干燥与对流干燥的能耗与成本对比分析

干燥作业是各行业中能耗较大的处理方法之一,我国干燥能耗约占全部工业能耗的12%。传导干燥比对流干燥节能20%—50%,但传导设备往往耗用金属材料较多,结构较复杂,主机造价较高,用户有时会因不能综合分析对比,只因主机投资较大,放弃节能产品的选用。文中利用通用的Excel程序,建立了一种定量的能耗及干燥成本综合对比分析方法,可方便迅速地对不同干燥方法定量比较,给出节能对投资的回报率,从而优选出节能干燥设备,对推动节能产品的应用、降低干燥成本具有重要意义。     

热敏性物质精馏系统的模拟优化

对丙烯酸等热敏性物质精馏系统进行了研究.建立了以NRTL方程为活度系数方程的计算模型,使用Aspen Plus模拟软件优化了丙烯酸精馏过程中的主要参数并对工艺流程进行了模拟计算,以降低精馏系统操作温度、提高系统处理能力为主要目的,从而降低了丙烯酸等热敏性物质的聚合倾向,提出的工艺方案可用于指导实际的生产操作和设备改造,优化生产操作参数.     

蜡油加氢处理装置物料流向和能耗分析

对洛阳石化蜡油加氢处理装置物料平衡和能耗进行了统计分析,介绍了装置物流走向和收率、综合能耗组成及变化,为企业优化生产、降低加工成本提供了依据。装置原料是混合蜡油和氢气,产品主要是精制蜡油、加氢干气和加氢酸性气,副产柴油和石脑油。装置负荷在162 136~201 298 t的情况下,总收率约99.9%,并且总收率随装置处理量的增大而变大。     

Dynamic criteria for evaluating the energy consumption efficiency of drying equipment

A new approach to the evaluation of the efficiency of drying equipment is considered. The approach employs dynamic efficiency criteria that are calculated from time-distributed parameters (for batch drying) or space-distributed parameters (for continuous drying) rather than average or input-output data. This approach, in addition to comparing the operation efficiencies of various dryers, allows one to analyze how the efficiency changes during the drying. Sample efficiency evaluations using the dynamic criteria are performed on the basis of experimental data for various types of dryers (fluidized-bed, freeze, and microwave vacuum dryers) and various materials (DSSK-65 rubber, mannitol, lactose).Translated from Teoreticheskie Osnovy Khimicheskoi Tekhnologii, Vol. 39, No. 2, 2005, pp. 170–174.Original Russian Text Copyright © 2005 by Menshutina, Gordienko, Voinovskii, Kudra.     

Simulation and energy consumption analysis of a propane plus recovery plant from natural gas

This paper deals with the investigation of a cryogenic plant for the recovery of propane plus compounds from natural gas. The commercially available software ASPEN Plus® has been used to simulate the process, and to investigate the effect of the main operating variables on the efficiency of propane plus recovery and on the energy required by the various pieces of equipment of the plant. With respect to the base case considered, the optimized plant allows to reduce the heat required up to 25%; besides, the refrigeration required can be reduced up to 60%, without significantly affecting the propane plus recovery.     

生物质型煤干燥能耗的瞬态分析及预测模型

通过在不同干燥温度(140,160,180℃)、不同风速(0.4,0.8,1.2 m/s)下对生物型煤进行了干燥特性实验,并对其瞬时单位能耗进行了计算和分析,结果表明:生物质型煤干燥过程中,单位能耗曲线分为3个阶段:下降阶段、恒定阶段和上升阶段;当干燥速率处在升速阶段时,单位能耗随干燥温度和风速的提高下降迅速;当干燥速率处在恒速阶段时,单位能耗随干燥温度和风速的提高而降低;当干燥速率处在降速阶段时,单位能耗随干燥温度和风速的提高而快速上升。基于干燥特性数学模型——Sabbet方程,得到了生物质型煤干燥时瞬时单位能耗的预测模型,其可以有效地反映出生物质型煤在干燥过程中单位能耗瞬态变化,为生产和工艺改进提供指导。     

Reducing energy requirement for drying of beet-pulp: Simulation of energy integration between superheated steam and air drying systems

Beet-pulp dehydration in the sugar industry is a highly energy intensive unit operation. Producing 1?kg of dried beet-pulp requires ～2–3?kg of water to be removed. The cost saving is a real challenge in sugar factory as the current dryers are underperforming (around 3?MJ/kg of water evaporated) because the heat recovery is limited and only a small proportion of dryer exhaust can be reused. The aim of this study was to investigate by simulation the energy efficiency of an independent multistage drying method that combines superheated steam drying (SHSD) and hot air drying (AD). Two case studies awarding the two types of energy coupling (AD then SHSD or SHSD then AD) are presented and compared. An approach of optimization is developed from energy balance. A number of operating parameters of the two drying configurations are investigated using sensitivity analysis. It proves that both cases allow an energy economy around 40% compared to the conventional dryer. Nevertheless, the SHSD-AD plant may present more benefits for a better quality product.     

Thermal intermittent drying of apples and its effects on energy consumption

This study investigated thermal intermittence in apple drying, conducted in two stages, and its effect on energy consumption, drying kinetics, color and chlorogenic acid retention. The energy consumption was measured using an energy analyzer and calculated through an energy balance. The results indicate intermittent drying advantages, such as an improvement in effective diffusivities and drying rates, a consequent reduction in the total processing time (35%) and no impairment of color parameters and chlorogenic acid retention. The consumption measures showed 17% energy savings, which could have been higher if insulation was improved, and a theoretical energy savings of up to 35% was obtained from calculations in adiabatic conditions.     

Modeling of heat pump tumble dryer energy consumption and drying time

The use of heat pump tumble dryers is nowadays more common because they offer huge energy savings compared to conventional tumble dryers. Earlier studies made on conventional tumble dryers have shown that parameters such as heater power, fan speed, drum speed, weight and initial moisture content of textiles and air leakage have a huge impact on the energy efficiency and drying time. In the present study, a modified commercial heat pump tumble dryer was evaluated for energy consumption and drying time by changing operating parameters including fan speed, drum speed, and mass load. The total energy consumption and drying time were measured and corrected for the initial and final moisture content in the textiles. The experimental results based on 27 drying tests were evaluated to develop linear regression models for energy consumption and drying time, which show a good agreement with the experimental data. The results show that a large mass load, a high drum speed, and a low fan speed give the highest energy efficiency, i.e. the lowest energy consumption per kg of drying load. Larger loads extend the length of the drying cycle while higher fan and drum speeds result in shorter drying time.