摘要
高压至低、中压空间的液氨等焓节流过程中 ,液氨的微分节流效应 ,μH=( T/ p) H>0 ,为制冷效应 ,积分节流效应的ΔTH 数值与节流前后的状态 (T、p)有关 ,当节流后压强p2 一定 ,节流前压强p1愈高 ,温度T1愈低时 ,冷却度ΔTH 就愈大 .推得了液氨焓与压力的关系式及ΔTH 的计算方法 ,冷却度ΔTH 的计算值与实验测定值误差很小 ,能满足指导实际工作的需要 .在中压法氨合成系统中应用 ,分别可以获得 7 5℃与 15℃的冷却度 ,应用液氨等焓节流效应 ,适当配合冷量回收与节能的技术措施 ,在有条件的氨合成系统中 ,可以革除冷冻工序 ,实现冷量自给 ,获得节约能耗、降低成本的效益 .
The differential throttling effect of liquid ammonia, μH=(&partΤ/&partp)H>0, for the isoenthalpy throttling process of liquid ammonia from high pressure to low and moderate pressure, means a refrigerating effect. The magnitude of the integral throttling effect ΔTH depends on the states (T, p)before and after throttling. Given the post-throttling pressure p2, the refrigerating extent ΔTH is larger when the initial temperature is lower and the pressure is higher before throttling. The relationship of enthalpy with pressure and the computing method of ΔTH or the liquid ammonia were derived. The deviation was small for the calculated refrigerating extent ΔTH in comparison with the experimental value, which met the requirements for practical use. It was found that a refrigerating extent from 7.5°C to 15°C could be obtained in the ammonia-synthesis system with a moderate operating pressure. To benefit from lower energy consumption and production cost, the refrigeration working procedure in the present ammonia-synthesis system could be replaced by exploiting the self-generating refrigerating effect from the throttling effect of liquid ammonia, as well as some techniques of cold quantity reclaiming and energy saving.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2004年第9期1400-1405,共6页
CIESC Journal
关键词
液氨
节流效应
冷却度
冷量
Ammonia
Enthalpy
Heat exchangers
Liquids
Pressure
Temperature
Thermal insulation
