oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
纺织厂烘燥设备的节能和废热回收  [PDF]
纺织学报 , 1983,
Abstract: 本文将烘燥设备中的热能消耗,分为蒸发织物中水分的热量、加热通过的空气的热量、加热织物的热量、烘燥箱体蒸汽漏失的热量、烘燥箱体散失的热量等五部分,分别讨论了各部分热耗的计算和减低热耗的方法。最后还讨论了废热回收的问题。
溶液加冷剂回热双吸收式热变换器循环性能分析
Performance analysis of double absorption heat transformers with solution and coolant heat regeneration cycle
 [PDF]

纪光菊,陈亚平,吴嘉峰,吉鸽
- , 2017, DOI: 10.3969/j.issn.1001-0505.2017.01.016
Abstract: 基于溶液回热双吸收式热变换器循环,提出了一种溶液加冷剂回热双吸收式热变换器循环方案,即在溶液回热双吸收式热变换器的吸收蒸发器稀溶液出口增加了一个溶液与冷剂间的热交换器.计算并比较了吸收蒸发器稀溶液出口溶液无回热、有溶液回热以及同时有溶液和冷剂回热3种双吸收式热变换器循环的性能系数和效率.结果表明,溶液加冷剂回热双吸收式热变换器循环不仅具有较宽的吸收蒸发温度变化范围,而且在整个吸收蒸发器操作范围内可使循环性能系数和效率进一步提升,当吸收温度、发生温度、冷凝温度和吸收蒸发温度分别为120~150,70, 25和80~115 ℃时,性能系数和效率较有溶液回热双吸收式热变换器循环增加约2.5%~3.5%.同时分析了吸收温度、冷凝温度、发生温度和吸收蒸发温度变化时吸收蒸发器稀溶液出口无回热、有溶液回热以及同时有溶液和冷剂回热3种循环的性能系数和效率的变化趋势.
Based on the cycle of double absorption heat transformer with solution heat regeneration, a modified cycle of double absorption heat transformer with both solution and coolant heat regeneration was proposed by adding a heat exchanger between solution and coolant at the outlet of dilute solution of the absorber-evaporator. Both coefficients of performance(COP)and exergy efficiencies of three kinds of cycles in double absorption heat transformers without heat regeneration, with solution heat regeneration and with both solution and coolant heat regeneration at the outlet of dilute solution of the absorber-evaporator were calculated and compared. The results show that the new cycle of double absorption heat transformer with solution and coolant heat regeneration has a wider operating range of absorption-evaporation temperature and higher COP and exergy efficiency in the discussed scope. When the temperatures of absorption, generation, condensation and absorption-evaporation are 120 to 150, 70, 25 and 80 to 115 ℃, respectively, the COP and exergy efficiencies of the new cycle increase by about 2.5% to 3.5% compared with those of the one with solution heat regeneration only. The variation trends of COP and exergy efficiency of the three cycles versus the temperatures of absorption-evaporation, condensation, generation and absorption are analyzed
水化热对地源热泵地埋管夏季换热效果的影响  [PDF]
夏才初,刘志方,肖素光
- , 2015, DOI: 10.11908/j.issn.0253-374x.2015.09.008
Abstract: 通过数值模拟与现场实测地温的变化,研究了水泥水化热对地埋管周围地温的影响;通过理论分析、现场实测地埋管换热能力以及数值模拟研究了地埋管周围地温变化对地埋管夏季工况换热效果的影响。对上海自然博物馆地埋管系统的研究表明:(1)在地源热泵投入使用时,地下室底板以下约10m处的地温受水泥水化热影响最大,距离地下连续墙2.85m处地温的平均升高为2.2℃;(2)地埋管夏季工况的换热量随初始地温的升高而线性减小,地埋管周围地温每升高1℃,将使地埋管夏季工况的换热量减小5%以上。(3)地源热泵系统由夏季工况作为首次投入使用时应对距离地下连续墙13m以内地埋管采取相应措施,以保证换热系统高效运行。
Influence of the hydration heat by cement on the ground temperature around the ground heat exchanger was investigated by numerical simulation and field measurement for ground temperature. Influence of the ground temperature around the ground heat exchanger on the heat transfer effect in ground heat exchanger was investigated by theoretical analysis, heat transfer experiments of ground heat exchanger, and numerical simulation. Researches on the ground heat exchanger in Shanghai Museum of Natural History shows that the ground temperature approximately 10 m below the basement floor is most affected by the hydration heat of cement, and the average ground temperature 2.85 m away from the underground diaphragm wall increases by 2.2℃, when the ground source heat pump system is initiated. The heat transfer rate in ground heat exchanger decreases linearly with the increase in initial ground temperature in summer; Moreover, the heat transfer rate in the ground heat exchanger decreases by more than 5% in summer when the ground temperature around the ground heat exchanger is 1℃ higher. Measures should be taken to the ground heat exchangers whose distances between the underground diaphragm wall are no more than 13 m to ensure an efficiently operational heat transfer system, when the system is initiated in summer
海南岛燥红土发生学特性的薄片观察  [PDF]
熊德祥,武心齐
南京农业大学学报 , 2000, DOI: 10.7685/j.issn.1000-2030.2000.04.015
Abstract: 燥红土薄片的显微镜观察表明,由于长期受干热的生物气候条件影响,燥红土在发育过程中矿物风化淋溶程度较弱,各种分解形态的有机残体数量少,有机质含量缺乏。燥红土的主导形成过程是红化作用,由于遭受侵蚀,燥红土近代成土过程遭受砂化,表层呈现漂白砂型土壤微垒结。
忽略回填料与岩土热物性差异对桩基埋管换热计算的影响
Heat transfer calculation influence of pile geothermal ground exchanger ignoring the thermal property difference between grout and soil
 [PDF]

黄光勤,卢军,杨小凤
- , 2015, DOI: 10.11835/j.issn.1674-4764.2015.02.008
Abstract: 桩基埋管换热器具有桩径大、埋深浅的特点,适用于桩基埋管特点的系列导热解析解模型被不断提出,但是该类模型均忽略了回填料与岩土热物性的差异。对于桩径较大的桩基埋管而言,较大的热物性差异将引起较大的计算误差。建立了区别回填料与岩土热物性差异的导热数值解模型,对比分析忽略热物性差异对桩基埋管换热计算的影响,研究表明:导热系数差异对桩基埋管长时间运行的换热热阻计算影响甚小;容积比热差异将引起桩基埋管较大的设计容量误差;桩径越大,热物性差异引起的计算误差越显著。
Pile geothermal heat exchanger is characterized by bigger pile diameter and shallow buried depth,and current studies presented the analytical solution models only considering soil conduction ignoring the thermal property difference between grout and soil which would induce the calculation error for big pile diameter. A conduction numerical solution model considering the thermal property difference was developed to analyze the heat transfer influence of pile geothermal heat exchanger induced by thermal parameter difference. Results showed that conductivity difference had little impact on the heat transfer when the operation time was long and the difference of specific heat would induce big error of the ground heat exchanger design capacity and the bigger the pile diameter was,the more obvious the calculation error.
遗传-模拟退火算法优化设计管壳式换热器
Optimization of a shell-and-tube heat exchanger based on a genetic simulated annealing algorithm
 [PDF]

肖武,王开锋,姜晓滨,贺高红
- , 2016, DOI: 10.16511/j.cnki.qhdxxb.2016.24.021
Abstract: 依据Bell-Delaware法对壳程流体进行压降和传热的计算,选择管径、管长、折流挡板数等结构参数作为主要设计变量,参考了美国管式换热器制造商协会(Tubular Exchanger Manufacturers Association, TEMA)标准作为相关约束条件,以换热器的年度总费用最低为目标函数,建立了管壳式换热器优化设计数学模型,并基于遗传-模拟退火算法(GA-SA)进行求解。文献算例的对比结果表明:算法能较好地权衡换热器的换热面积费用和泵的操作费用并搜索到全局最优解,从而获得总费用较低的换热器主要结构参数。针对一个实际工程项目,考虑换热器设计裕度要求,计算结果与商业化软件HTRI的预测值接近,说明所设计的换热器实际可行。同时克服了HTRI需要设计者的经验确定设计变量和无法保证经济性最优的不足。
Abstract:A mathematical model was developed to optimize the design of a shell-and-tube heat exchanger based on design data obtained by using the Bell-Delaware method to describe the pressure drop and heat transfer on the shell-side. The design variables were the tube diameter, the tube length, and other geometric parameters with the Tubular Exchanger Manufacturers Association (TEMA) standard taken as the reference for the constraints and the minimum total heat exchanger cost as the objective. The solution used the genetic simulated annealing algorithm (GA-SA). This method more effectively balances the heat exchanger area cost and pumping cost than previous methods by searching for the global optimal solution for the main geometric heat exchanger parameters with the minimum total cost. With the margin requirement for heat exchanger designs for specific industrial projects, these results are close to those given by commercial HTRI software, which indicates that this heat exchanger design method is reliable. This method guarantees the economic optimum without an empirical method to optimize the design variables in the heat exchanger design which is a major weakness of HTRI software packages.
MHA型烘燥机  [PDF]
纺织学报 , 1986,
Abstract: <正>MHA型烘燥机是一种高效、节能、结构紧凑、操作方便的烘燥机,适用于麻、毛等纤维的干燥。它与传统的B061型烘燥机的对比如下:MHA型与B061型烘燥机主要指标对比型号MHA型B061型产量(吨/班)1.481风机用电机(千瓦)11.814
钛合金螺旋扁管换热器流阻与传热性能实验研究
6Experimental Research on the Flow Friction and Heat Transfer Performance in Titanium Alloy Twisted Tube
 [PDF]

董新宇,毕勤成,贺宇峰,王腾,桂淼
- , 2018, DOI: 10.7652/xjtuxb201801003
Abstract: 为研究钛合金螺旋扭曲扁管换热器壳侧选用高黏度导热油的传热规律,对钛合金螺旋扁管换热器的壳侧在层流(Re<2 000)与过渡流(2 000To study the heat transfer performance at the shell side of the titanium alloy spiral twisted tube heat exchanger with high viscosity heat transfer oil, experimental research was conducted on the laminar flow (Re<2 000) and transition flow (2 000
基于火积耗散原理的热网加热器优化设计与分析  [PDF]
赵麒,谭羽非,王琛
- , 2016, DOI: 10.11918/j.issn.0367-6234.2016.08.023
Abstract: 为使热网加热器具有最优的换热性能,基于粒子群优化算法,以(火积)耗散数为目标函数,提出热网加热器优化设计的最小(火积)耗散优化方法.与传统的热网加热器设计计算不同,本文的优化设计不预先设定热网加热器的结构,通过优化确定热网加热器的最佳尺寸,同时,热网加热器优化设计考虑了工质的相变,以潜热修正值对壳侧蒸汽凝结的对流换热系数进行修正.对一热网加热器优化设计结果表明,通过优化设计,热网加热器的效能增加7.8%,同时热网加热器功率消耗下降19.6%,表明当热网加热器的热力性能最优时,其功耗达最小值.
To optimize the heat transfer performance of the thermal-system heater, based on the particle swarm optimization algorithm and entransy dissipation theory, in this paper, a minimum entransy dissipation approach for optimization design was developed, taking entransy dissipation number as the objective function. The optimum size of the heat exchanger was determined without the pre-set structure of the heat exchanger and the phase change of working fluid of the heat exchanger was considered in the optimization design progress, which is different from the traditional design calculation. The convection heat transfer coefficient of steam condensation on the shell side was corrected by the latent heat value. For a specific thermal-system heater, the optimized design results showed that the exchanger effectiveness was increased by about 7.8%, while the pumping power reduced by about 19.6%, indicating that it achieved minimum power consumption when the thermal performance of thermal-system heater was optimized.
基于系统经济优化的换热器设计
Heat Exchanger Design Based on Systematic Economic Optimization
 [PDF]

,,齐文哲,阮仁君,刘春江,,
- , 2016, DOI: 10.11784/tdxbz201411063
Abstract: 传统换热器设计依赖于设计者的经验,通过实际操作条件要求进行选型与设计参数的调整,很少考虑设备经济性.以传热效率X 和综合利润Ctotal为目标函数,基于技术经济学原理,对流道长度、换热面积及冷热进口流量设计参数进行了数值模拟.模拟研究了各参数对目标函数的影响.结果表明:传热效率随流道长度的增长而提高,并在长度大于10,m 时趋于稳定;而压降与各参数变量呈指数关系;进出口流量对传热效率影响不大,但因此导致的高压降会使综合利润降低;换热面积越大,换热效果越好;根据对综合利润的分析,流量长度增加、换热面积减小会导致综合利润的降低.兼顾传热效率、综合利润值,对换热器进行了优化设计.
Traditional heat exchanger design is an iterative process relying heavily on the experience of designers. Usually a referential geometric configuration of the heat exchanger is chosen,and then the design parameters are adjusted according to the requirement of the actual situation.However,the traditional design may not be costeffective for the lack of cost criteria.Based on the principle of technical economics,the heat transfer efficiency X and combined profits Ctotal were considered as the objective functions.Taken channel length,area of heat transfer and flow rate of cold and hot inlets as variables,the effect was simulated.According to the results,with the increase of length of channel,the heat transfer efficiency increases.Once the length is greater than 10 m,it remains almost the same.Meanwhile,the pressure drop exponentially changes with the variables.Flow rate has little effect on heat transfer efficiency,but the increase of pressure drop will lead to combined profit decline.The larger the area of heat exchanger,the better effect of heat transfer efficiency.Besides,the increase of channel length and decrease of heat transfer area will lead to smaller combined profits.Taken the efficiency of heat transfer,and value of combined profit into consideration,the heat exchanger is optimized
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.