热科学与技术
熱科學與技術
열과학여기술
JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY
2015年
2期
155-160
,共6页
CO2%低温循环工质%复叠式制冷系统
CO2%低溫循環工質%複疊式製冷繫統
CO2%저온순배공질%복첩식제랭계통
CO2%refrigerant in low-temperature circuit%cascade refrigeration system
通过对 NH3/CO2、R290/CO2和 R404A/CO2三种复叠式制冷系统的COP、最优低温循环冷凝温度和最佳质量流量比等进行理论分析及性能比较,得出在一定的蒸发温度、冷凝温度和冷凝蒸发器传热温差下,三种复叠式制冷系统的COP都随着低温循环冷凝温度的升高呈现出先增大后减少的趋势,其中 NH3/CO2复叠式制冷系统的COP最大；三种复叠式制冷系统的最佳低温循环冷凝温度和最佳质量流量比都随着蒸发温度的升高而升高,其中 R404A/CO2复叠式制冷系统的最佳低温循环冷凝温度最高,NH3/CO2复叠式制冷系统的最佳质量流量比最大。
通過對 NH3/CO2、R290/CO2和 R404A/CO2三種複疊式製冷繫統的COP、最優低溫循環冷凝溫度和最佳質量流量比等進行理論分析及性能比較,得齣在一定的蒸髮溫度、冷凝溫度和冷凝蒸髮器傳熱溫差下,三種複疊式製冷繫統的COP都隨著低溫循環冷凝溫度的升高呈現齣先增大後減少的趨勢,其中 NH3/CO2複疊式製冷繫統的COP最大；三種複疊式製冷繫統的最佳低溫循環冷凝溫度和最佳質量流量比都隨著蒸髮溫度的升高而升高,其中 R404A/CO2複疊式製冷繫統的最佳低溫循環冷凝溫度最高,NH3/CO2複疊式製冷繫統的最佳質量流量比最大。
통과대 NH3/CO2、R290/CO2화 R404A/CO2삼충복첩식제랭계통적COP、최우저온순배냉응온도화최가질량류량비등진행이론분석급성능비교,득출재일정적증발온도、냉응온도화냉응증발기전열온차하,삼충복첩식제랭계통적COP도수착저온순배냉응온도적승고정현출선증대후감소적추세,기중 NH3/CO2복첩식제랭계통적COP최대；삼충복첩식제랭계통적최가저온순배냉응온도화최가질량류량비도수착증발온도적승고이승고,기중 R404A/CO2복첩식제랭계통적최가저온순배냉응온도최고,NH3/CO2복첩식제랭계통적최가질량류량비최대。
Three kinds of cascade refrigeration systems, namely NH3/CO2 , R290/CO2 and R404A/CO2 ,were analyzed and compared theoretically in terms of coefficient of performance (COP), optimum condensing temperature of CO2 and optimum mass flow rate ratio.The results show that,at definite evaporating,condensing temperatures and heat-transfer temperature difference of condensing evaporator,the COP of three kinds of cascade refrigeration systems firstly increases and then decreases with an increase in condensing temperature of CO2 ,and the COP of NH3/CO2 cascade refrigeration system is higher than that of the others.With an increase in evaporating temperature, the optimum condensing temperature of CO2 and optimum mass flow rate ratio of three kinds of cascade refrigeration systems increase, and the optimum condensing temperature of CO2 of R404A/CO2 cascade refrigeration system,the optimum mass flow rate ratio of NH3/CO2 cascade refrigeration system are the highest.
