不同制冷劑噴射制冷性能計算分析

王菲，沈勝強

(大連理工大學(xué)海洋能源利用與節(jié)能教育部重點實驗室，遼寧大連116024)

摘要：引入制冷劑的實際物性，建立了噴射器熱力學(xué)模型;比較了沸點相近工質(zhì)在噴射器內(nèi)的壓力和速度變化趨勢及噴射系數(shù)，探討了引起噴射器性能差異的主要物性因素;比較了幾組具有相近沸點制冷劑的噴射制冷性能。結(jié)果表明：對沸點相近的工質(zhì)來說，一般工作蒸氣的比焓值越商。噴射系數(shù)越高;沸點相近的工質(zhì)對中，R717的性能優(yōu)于R290，R152a優(yōu)于R134a，R14】b優(yōu)于R123，R142b優(yōu)于R600af在研究的所有制冷劑中，R717的制冷性能z*好，R152a次之，兩者的c0P(性能系數(shù))值差隨發(fā)生溫度的升高而增大。

關(guān)鍵詞：噴射式制冷;噴射系數(shù);COP;制冷劑

中圖分類號：TK 511+.3 文獻標識碼：A 文章編號：0438—1157(2010)02一0275一06

Calculation and analysis for an ej ector refrigeration

system with VariOus refrigerants

WANG Fei，SHEN Shengqiang

Abstract： A thermodynamic model of ej ector was established by introducing refrigerant property.Thechange in pressure and temperature in the ejector and the entrainment ratio of ejector for seVeralrefrigerants with similar normal boiling point were compared，and the difference in injector performancewas analyzed according to refrigerant properties.The refrigeration performances of seVeral pairs ofrefrigerants with similar normal boiling points were also compared.The results indicate that higher specific enthalpy of driving vapor results in higher entrainment ratio of ejector.Among the refrigerants studied， R7 1 7 gives the best perfofmance and R1 52a takes the second place，and their COP difference increases with generation temperature.

Key words：ejector refrigeration;entrainment ratio;COP;refrigerant