摘要
为了提高空温式气化器(AAV)的气化能力和使用效率,将直膨式太阳能热泵应用于液化天然气(LNG)气化,提出基于太阳能热泵的LNG气化系统(DX-SAHPNV),建立AAV在强制对流换热条件下的传热传质模型,并分析送风温度、相对湿度、送风速度和LNG入口温度对系统中AAV气化性能的影响。结果表明,强制对流换热条件下,送风温度每升高10 K,AAV出口温度至少升高3.49%;送风速度每增大1 m/s,液相区长度至少缩短11.11%;AAV入口温度每升高5 K,两相区长度至少缩短3.70%;相对湿度对AAV气化性能影响很小。结论认为,DX-SAHPNV系统能保证集热/蒸发器有效吸收太阳能和空气能,预热部分LNG和实现AAV实时化霜化冰。
In order to improve the vaporization capacity and operational efficiency of air ambient vaporizer(AAV),a novel LNG vaporization system utilizing a direct-expansion solar assisted heat pump(DX-SAHP)was developed,while a heat and mass transfer model was developed to assess the AAV performance under the condition of forced convection.Based on the simulation results,the effects of air temperature,relative humidity,air flow rate and temperature flowing into the vaporizer on the AAV performance were analyzed and discussed,while keeping all other parameters constant.Some conclusions were obtained as follows:First,the temperature of natural gas discharged from the AAV increases by more than 3.49%per 10 K increase in air temperature when it ranges from 273 to303 K.The liquid zone length of finned tube decreases by at least 11.11%per 1 m/s increase in air flow rate when it varies from 3 to 6 m/s.The two-phase zone length of finned tube decreases by at least 3.70%per 5 K increase in the LNG temperature at the inlet of AAV when it is within a range from 116 to 126 K.Second,since the little difference in the temperature of natural gas discharged from the AAV as the relative humidity increases from 30%to 90%,relative humidity has little effect on the performance of AAV.In summary,the DXSAHPNV system alleviates or eliminates the formation of frost and ice on the surface of finned tube and improves the AAV performance,which provides qualitative and quantitative theoretical guidance for the operation of DX-SAHPNV.
作者
时国华
代瑞
林俊华
王江江
李丹
Shi Guohua;Dai Rui;Lin Junhua;Wang Jiangjiang;Li Dan(School of Energy and Mechanical Engineering,North China Electric Power University,Baoding 071003,China;Haneheng Real Estate Ltd.,Greentown Group,Hancheng 715400,China)
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2021年第5期302-308,共7页
Acta Energiae Solaris Sinica
基金
河北省自然科学基金(E2016502027)
中央高校基本科研业务费专项资金(2017MS124)。
关键词
液化天然气
热泵
太阳能强制对流
空温式气化器
霜阻
换热效率
liquefied natural gas
solar heat pump systems
forced convention
ambient air vaporizer
frost thermal resistance
heat transfer coefficients
