中文摘要：

提出了一种新的计算舒适性空调中可燃制冷剂最大允许充注量的方法。与EN378—2008标准推荐的计算方法相比，新方法综合考虑了可燃制冷剂的最低可燃下限、最小点火能、火焰传播速度、燃烧热以及燃烧产物等燃烧特性参量对于制冷剂最大允许充注量的影响。又假设R32为基准制冷剂，例论了可燃制冷剂R152a、R290、R1234yf、R600a和R717的对应修正系数。结果显示R32的综合可燃危险性与R1234yf接近，R152a的最大允许充注量应适当削减，R717在此基准情况下凸显比另外五种可燃制冷剂更适用于大型制冷／制热设备的特点。

英文摘要：

A new assessment methodology on the maximum allowable charge of flammable refrigerants in human comfortable air conditioning systems was proposed. Compared with the previous calculating method listed in the BS EN-378 Standard, the new method covered more comprehensive consideration from the aspects of five typical combustion characteristics, which are the lower flammable limit, minimum ignition energy, flame propagation velocity, heat of combustion and the production of combustion. Then the correction coefficients of R152a, R290, R1234yf, R600a and R717 were assessed under the new method by supposing R32 as the referenced substance. Results showed that the comprehensive combustion dangerousness of R32 was closed to that of R1234yf, and the maximum allowable charge of R152a should be cut down appropriately. On the current calculating conditions, R717 possessed its advantage on the application in larger heating and cooling equipment.