Gas Behavior in Refrigeration Systems

During the process of filling a graduated charging cylinder with liquid refrigerant, any vapor refrigerant that is vented from the top of the cylinder occurs as part of the phase change where the gas condenses to a liquid. This is a typical behavior when dealing with refrigeration cycles, where the working fluid undergoes a phase change.

In a refrigeration system, the refrigerant cools down as it flows back through an expansion valve to the outdoor evaporator coils, leading to the condensation of the gaseous refrigerant.

It's essential to understand that refrigerant gas is not leaking, and the cylinder does not change its size significantly as it warms up. When dealing with such gases, precautions are taken, such as sealing the flask after allowing a gaseous sample to condense to liquid, to determine the substance's mass accurately. The mass of the gas that once filled the flask can then be measured in its condensed liquid form.

If a second flask containing a vacuum is introduced and a valve is opened between it and a flask containing the gas, the gas will spontaneously become evenly distributed between the two flasks. This illustrates the gas laws in action, where a temperature difference can result in the movement of gas molecules from an area of higher pressure to a region of lower pressure, or in this case, a vacuum.