槽式太阳能聚光集热器热力学分析及聚光集热系统动态特性仿真  

Thermodynamic Analysis of Trough Solar Collector and Simulation of Dynamic Characteristics of Solar Trough Concentration System

作　　者：董晓明 吴玉庭[1] 张灿灿 鹿院卫[1] 马重芳[1] DONG Xiaoming;WU Yuting;ZHANG Cancan;LU Yuanwei;MA Chongfang(Key Laboratory of Enhanced Heat Transfer and Energy Conservation,Beijing Key Laboratory of Heat Transfer and Energy,Faculty of Environment and Life,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学环境与生命学部,传热强化与过程节能教育部重点实验室及传热与能源利用北京市重点实验室,北京100124

出　　处：《北京工业大学学报》2024年第8期1007-1026,共20页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51906003);内蒙古自治区科技重大专项资助项目(2021ZD0036)。

摘　　要：槽式太阳能聚光集热器是槽式集热系统关键部件之一,因此对其热力学性能分析至关重要。利用分布参数法构建了集热器的一维稳态模型,分别研究了熔盐进口流量、日照辐射量、环形空间压力等因素对集热器的火积耗散率、熵产率、(火用)损失率以及热损失率的影响。结果发现火积耗散率和熵产率均随熔盐进口流量、发射率的增大而减小,随日照辐射量增大而增大。当日照辐射量增大67%时,火积耗散率和熵产率分别增大191.4%和177.7%;(火用)损失率随各个参数的变化趋势与熵产率基本相同;热损失率随熔盐进口流量、环境温度的增大而减小,随日照辐射量、环形空间压力、环境风速、发射率的增大而增大,并且发射率影响最大,当发射率增大28.6%时,热损失率增大18.9%。同时为探究集热系统的动态特性,构建了双罐集热系统和单罐集热系统的动态仿真模型并进行仿真计算,结果发现双罐系统的动态响应时间要明显长于单罐系统;熔盐罐的数量和位置仅会对初始阶段系统的动态响应造成影响,不会对稳定时系统各部件工质出口温度造成影响。从火积耗散率和熵产率2个角度对系统进行了分析,结果表明:换热器的火积耗散率与熵产率均随时间先增大后保持不变,集热器以及熔盐罐的火积耗散率与熵产率均随时间先减小后保持不变。Trough solar collector is one of the key components of trough solar collector system,therefore,it is very important to analyze its thermodynamic performance.In this paper,a one-dimensional steady-state model of the collector was constructed using the distributed parameter method.The influences of molten salt inlet mass flow rate,solar radiation,annular space pressure and other factors on the entransy dissipation rate,entropy production rate,exergy loss rate and heat loss rate of the collector were investigated.Results show that the exuvial dissipation rate and entropy production rate decrease with the increase of molten salt inlet flow rate and emissivity.It increases with increasing solar radiation.When the amount of solar radiation increases by 67%,the entransy dissipation rate and entropy production rate increase by 191.4%and 177.7%,respectively.The variation trend of exergy loss rate with each parameter is basically the same as that of entropy production rate.The heat loss rate decreases with the increase of molten salt inlet mass flow rate and ambient temperature,and increases with the increase of solar radiation,annular space pressure,ambient wind speed and emissivity.When the emissivity increases by 28.6%,the heat loss rate increases by 18.9%.To explore the dynamic characteristics of the heat collection system,the dynamic simulation models of the two-tank heat collection system and the single-tank system were constructed and the simulation calculation was carried out.Results show that the dynamic response time of the two-tank system is obviously longer than that of the single-tank system.The number and location of molten salt tanks will only affect the dynamic response of the system in the initial stage,and will not affect the outlet temperature of each working medium in the system during stablization stabilized.The system was analyzed from entransy dissipation rate and entropy production rate.Results show that the entransy dissipation rate and entropy production rate of heat exchanger first increase with

关 键 词：集热器 火积理论 分布参数 动态仿真 传热 熔盐 

分 类 号：TK172[动力工程及工程热物理—热能工程]