摘要
采用R404A作为制冷剂对重力供液蒸发器在低温工况下的特性进行实验研究,建立重力供液蒸发器的传热模型,搭建重力供液蒸发器的实验装置,用热平衡法测试重力供液蒸发器在不同蒸发器供液高度下的运行特性。研究表明:供液压头在h1=1200mm时比供液压头在h1=800mm、h1=1000mm时的传热温差明显下降,且随着室内温度的下降,传热温差随之变小;在同一供液高度下,重力供液蒸发器的循环倍率n随蒸发温度的降低而增大,而在不同供液高度下,循环倍率n随供液高度的升高而增大;重力供液蒸发器在供液高度h1=1000mm时的制冷量明显高于h1=800mm时的制冷量,其最大增幅为16.9%;而h1=1200mm时其制冷量与h1=1000mm很接近,甚至会有所下降;与h1=800mm相比,h1=1000mm时重力供液制冷系统COP大幅度增加,最大增幅为17%,h1=1200mm时系统COP介于前两者之间,重力供液制冷系统存在最佳的蒸发器供液高度。
The characteristics of an evaporator using R404A with liquid refrigerant supply by gravity were investigated at lower temperature. A heat transfer model of an evaporator with liquid refiigerant supply by gravity was established. The experiment was conducted using the thermal balance method to obtain the operation characteristics of an evaporator with liquid refrigerant supply by gravity in different supply height. The results indicate that the logarithmic temperature difference between the evaporator and the indoor temperature was lowest when the supplying height hl=1200mm and decreased with the decrease in the indoor temperature. For the same supplying height, the circulating ratio of the evaporator increased with the decrease in the evaporation temperature. For the different supplying height, the circulating ratio of the evaporator increased with the increase in the supplying height. The refrigerating capacity when h1=1000mm was up to 16.9% higher than that when h7800mm. The refrigerating capacity when h1=1000mm was very close to that when h1=1200mm. The COP of the system when h1=1000mm was up to 17% higher than that when ht=800mm. It seems that there is an optimum supplying height for the evaporator with liquid refrigerant supply by gravity.
出处
《制冷学报》
CAS
CSCD
北大核心
2010年第1期54-58,共5页
Journal of Refrigeration
关键词
热工学
重力供液蒸发器
循环倍率
传热特性
热平衡
Pyrology
Evaporator with supplying liquid refrigerant by gravity
Circulating ration
Heat transfer characteristics
Thermal balance
