R-1234yf和R-134a之间的区别

R-1234yf和R-134a之间的区别

组件/设计差异

在汽车空调系统中压倒性地选择R-1234yf来替代R-134a的一个令人信服的原因之一是，因为系统的设计和工作方式之间并没有太多差异。热力膨胀阀（更换节流孔管或膨胀阀）和冷凝器有几处较小的组件更改，但总体而言，从事A / C系统工作的任何人都将熟悉该系统。两个系统中的服务端口都是快速连接的，但是在yf系统中它们较高，以避免交叉污染。

另一个区别是 R-1234yf蒸发器必须符合SAE Spec J2842，这在R-134a系统中不是问题。最后的区别是，大多数（尽管不是全部）R-1234yf汽车都将配备吸气管热交换器。该零件是生产线组件的一部分，旨在提高效率。它们没有活动部件。

工作压力/温度差异

R-1234yf和R-134a的压力/温度曲线非常相似。如下图所示，下面的曲线几乎一起贯穿整个曲线，仅在250 psig / 150度及以上时略有断开的路径

易燃/安全

R-1234yf被指定为轻度易燃。这仅表示如果与明火接触可能会燃烧。重要的是要注意它确实具有低燃烧速度和低热量或燃烧性。它的压力上升非常低，火焰移动非常缓慢（小于10厘米/秒）。与商店中的其他液体/化学品/气体相比，它是一种极其缓慢的移动火焰。它在车辆中的体积小，撞击性低。相比之下，如下表所示，它具有以下几种常见的汽车油：汽油，柴油，发动机油，变速箱油和动力转向液的可燃性影响更低。

上海路阳即将上市能够满足检测R-1234YF和R-134A冷媒泄漏的荧光检漏剂，敬请期待！

R1234YF制冷剂是一种无臭氧层破坏性且低全球变暖潜值(GWP）的车用空调制冷剂,符合欧盟汽车空调(MAC指令）,该指令旨在逐步停止高GWP制冷剂在汽车空调中的使用。 R1234YF的GWP<1根据AR5,完全符合欧盟MAC指令。 R1234YF表现出与R-134a相似的操作工况,可以在所有允许使用微弱可燃工质的场合替代R134a。R1234YF的安全分类为微弱可燃（A2L）,但如需在直膨式汽车空调系统中使用,仅需要适度地改变设计。

文章英文原文：

Differences between R-1234yf and R-134a
Component/Design Differences

One of the compelling reasons R-1234yf was overwhelmingly chosen to replace R-134a in automotive air conditioning systems is because there are not really many differences between the way the systems are designed and work.  There are a couple minor component changes in the Thermal Expansion Valves (replace orifice tubes or expansion valves) and Condensers, but overall the system will be familiar to anyone who works on A/C systems. The service ports in both systems are quick-connect, but they are taller in the yf systems to avoid cross-contamination.

Another difference is that yf Evaporators must meet SAE Spec J2842, which was not an issue in R-134a systems.
A final difference is that most (though not all) R-1234yf cars will have a Suction Line Heat Exchanger.  This part is part of the line assembly and is designed to improve efficiency.  They have no moving parts.

Operating Pressure/Temperature Differences

The pressure/temperature curves for R-1234yf and R-134a are very similar.  As illustrated in the chart below, the curves below run together nearly throughout the curve, only slightly breaking paths at around 250 psig/150 degrees and above

Flammability/Safety

R-1234yf has been designated as MILDLY flammable.  This simply means that it could ignite if it comes in contact with an open flame.  It is important to note that it does have a low burning velocity and low heat or combustion.  It has a very low pressure rise and the flame is very slow moving (less than 10cm/sec.)  Compared to other liquids/chemicals/gases in a shop, it  is an EXTREMELY slow moving flame.  It has low volume in a vehicle, and low impact flammability.  By comparison, and as illustrated in the chart below, it has the significantly  lowest flammability impact of the following common automotive fluids:  gasoline, diesel, engine oil, transmission fluid, and power steering fluid.