R1234yf四氟丙烯和R134a四氟乙烷之間的區(qū)別
首先：在汽車空調(diào)系統(tǒng)中壓倒性地選擇R-1234yf來替代R-134a的一個令人信服的原因之一是，因為系統(tǒng)的設(shè)計和工作方式之間并沒有太多差異。熱力膨脹閥（更換節(jié)流孔管或膨脹閥）和冷凝器有幾處較小的組件更改，但總體而言，從事A / C系統(tǒng)工作的任何人都將熟悉該系統(tǒng)。兩個系統(tǒng)中的服務(wù)端口都是快速連接的，但是在yf系統(tǒng)中它們較高，以避免交叉污染。
工作壓力/溫度差異
R1234yf四氟丙烯和R134a四氟乙烷的壓力/溫度曲線非常相似。在250 psig / 150度及以上時略有斷開的路徑
組件/設(shè)計差異
在汽車空調(diào)系統(tǒng)中壓倒性地選擇R-1234yf來替代R-134a的一個令人信服的原因之一是，因為系統(tǒng)的設(shè)計和工作方式之間并沒有太多差異。熱力膨脹閥（更換節(jié)流孔管或膨脹閥）和冷凝器有幾處較小的組件更改，但總體而言，從事A / C系統(tǒng)工作的任何人都將熟悉該系統(tǒng)。兩個系統(tǒng)中的服務(wù)端口都是快速連接的，但是在yf系統(tǒng)中它們較高，以避免交叉污染。
易燃/安全
R-1234yf被指定為輕度易燃。這僅表示如果與明火接觸可能會燃燒。重要的是要注意它確實具有低燃燒速度和低熱量或燃燒性。它的壓力上升非常低，火焰移動非常緩慢（小于10厘米/秒）。與商店中的其他液體/化學(xué)品/氣體相比，它是一種極其緩慢的移動火焰。它在車輛中的體積小，撞擊性低。相比之下，如下表所示，它具有以下幾種常見的汽車油：汽油，柴油，發(fā)動機油，變速箱油和動力轉(zhuǎn)向液的可燃性影響更低。
英文：
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.
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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.
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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
