摘要
保冷效果评价国标规定:保冷结构外表面温度应高于设计工况下的空气露点温度。然而,保冷结构外表面温度和空气露点温度均随环境参数的变化而波动,这给保冷结构外表面温度及设计工况下空气露点温度的确定带来不便。本文基于传热学和空气物理特性相关知识,分析了保冷结构的传热过程,拟合了保冷结构外表面温度与空气露点温度的差值(Δt_(w-l))和环境温湿度之间的函数关系,分析了空气温湿度对Δt_(w-l)的影响。并以哈尔滨地区空气参数为例,对分析结果进行了验证。在此基础上,对国标中的设计工况提出了改进建议。结果表明,Δt_(w-l)随室外空气干球温度及相对湿度的升高而近似一阶线性降低;现有国标规定的以夏季空调室外计算干球温度和最热月平均室外计算相对湿度作为设计工况不能代表实际运行的最不利工况;建议在进行保冷设计与保冷效果评价时,环境空气干球温度取当地室外空气干球温度较大值,相对湿度取最热月最大室外计算相对湿度。
In the evaluation standard of the cold storage effect, the outer surface temperature of the cold insulation structure should be higher than the dew point temperature under the design conditions. However, it is difficult to determine the outer surface temperature of the cold storage structure and the dew point temperature under the design conditions, which vary with the change of the environmental parameters. The difference between the outer surface temperature of the cold storage structure and the dew point tem- perature was defined as Δt（w-l） in this paper. The functional relationship between Δt（w-l） and the ambient temperature and humidity was fitted by analyzing the heat transfer process of cold storage structure. The influence of air temperature and humidity on Δt（w-l） was analyzed. Based on the analysis of air parameters in Harbin area, the results were validated. Some suggestions were proposed for the design conditions of cold storage. The results show that Atw-l decreased approximately first -order linear with the increase of outdoor air dry bulb temperature and relative humidity. Outdoor dry bulb temperature for summer air con- ditioning and the hottest month average relative humidity used as the design condition in the national standard cannot represent the most unfavorable conditions. It is suggested that the larger ambient air dry bulb temperature and the hottest month maximum relative humidity should be used in the design and eval- uation of cold storage structure.
出处
《节能技术》
CAS
2017年第6期505-508,共4页
Energy Conservation Technology
基金
黑龙江省青年科学基金项目(QC2014C047)
关键词
保冷
评价
露点温度
相对湿度
温湿度
cold insulation
evaluation
dew point temperature
relative humidity
temperature and humidity
