SPECIFICALLY, we are going to study what happens when R600A gas is added to a system that originally uses R290 refrigerant, resulting in a mixture of refrigerants within the system.
Let’s start by saying that although the equipment can cool, it is not recommended to mix these gases because it alters the operation points of the refrigeration cycle. However, we will explore everything that can happen when the mixture is performed so that the concepts become clear.
Remember that both gases are compatible with mineral oil, POE oil, and alkylbenzene.
After a proportion of more than 50% of R600A, as the amount of R600A refrigerant in the mixture increases, the coefficient of performance of the system (COP) decreases, meaning the system becomes less efficient.
On the screen, we have different performance values for some mixtures between R600A and R290.
As the amount of R600A increases in the mixture, with values well above 50% of R600A, the cooling capacity or refrigeration power of the system starts to decrease. In other words, it takes more time to cool down or has the ability to cool down fewer products.
On the screen, we have different cooling power values for some mixtures between R600A and R290.
The greater the amount of R290 in the mixture, without exceeding 50% concentration, the compressor discharge temperature decreases. After surpassing 50%, the opposite occurs. Remember that a lower compressor discharge temperature increases the lifespan of the motor windings.
On the screen, we have different discharge temperature values for some mixtures between R600A and R290.
Before the 50% proportion of R600A in the mixture, as the amount of R600A increases, the mass flow rate of refrigerant in the equipment increases, along with the need for other capillary tube measures.
On the screen, we have different mass flow rate values for some mixtures between R600A and R290.
Experimentally, it has been demonstrated that the optimal efficiency point for the mixture of R600A and R290 is when each gas contributes 50% by mass to the mixture.