摘要
为了提高太阳能热水系统中换热系统膨胀定压设计的准确性,本文通过对3种采用不可压缩换热工质的闭式循环换热系统的特点进行对比,以及对我国北方地区的太阳能热水系统中换热系统采用单膨胀罐形式时的膨胀定压设计进行了理论分析,给出了膨胀罐的预存压力、最大工作压力、所需容积的确定方法,并针对工程应用对采用乙二醇型防冻液作为换热工质时单膨胀罐的膨胀定压公式进行了简化。分析结果表明:采用单膨胀罐形式作为太阳能热水系统中换热系统的膨胀定压形式时,膨胀罐容积计算的准确性对换热系统的稳定运行起到关键作用;采用乙二醇型防冻液作为换热工质时,不能简单套用热水供应工程中以水作为换热工质时常用的膨胀定压计算公式;将乙二醇型防冻液的温度膨胀系数简化为0.0007,可以满足太阳能热水系统中换热系统的工程实践要求。
In order to improve the accuracy of expansion and constant pressure design of heat exchange system in solar water heater system,this paper compares the characteristics of three kinds of closed-cycle heat exchange systems with incompressible heat exchange medium,theoretical analyzes the expansion and constant pressure design that the heat exchange system of solar water heater system used in the northern region of China adopts the form of single expansion tank form,and gives the pre storage pressure,maximum working pressure,the method of determining the required volume,and for engineering application,the expansion and constant pressure formula of single expansion tank using ethylene glycol-type antifreeze as heat exchange medium is simplified.The results show that when the single expansion tank form is used as the expansion and constant pressure form of the heat exchange system in the solar water heater system,the accuracy of the volume calculation of the expansion tank plays a key role in the stable operation of the heat exchange system.When ethylene glycol-type antifreeze is used as heat exchange medium,the common expansion and constant pressure calculation formula when water is used as heat exchange medium in hot water supply engineering cannot be simply applied.The temperature expansion coefficient of ethylene glycol-type antifreeze is simplified to 0.0007,which can meet the engineering practice requirements of heat exchange system in solar water heater system.
作者
张建强
郭卫星
陈华
Zhang Jianqiang;Guo Weixing;Chen Hua(Tianjin Eco-city Construction and Investment Co.,Ltd.,Tianjin 300467,China)
出处
《太阳能》
2022年第1期77-82,共6页
Solar Energy
关键词
太阳能热水系统
换热系统
膨胀定压
膨胀罐
换热工质
乙二醇
防冻液
solar water heater system
heat exchange system
expansion and constant pressure
expansion tank
heat exchange
ethylene glycol medium
antifreeze
作者简介
通信作者:郭卫星(1986-),男,硕士、高级工程师,主要从事太阳能热利用方面的研究。guoweixing@tjeco-city.com。
