18 May 2017

K.3.1.1 Evaluation and Development of Air-conditioners using Low GWP Refrigerant

It is important to make the refrigeration technologies sustainable to the environment in order to continue to provide people with many technical benefits for a long time. In particular, to cope with global warming by reducing greenhouse gas and saving energy is an immediate task in the world. Characteristics of R32 for environment and high efficiency are effective for this opportunity in residential air-conditioner market, and 20 million R32 air-conditioners have already been sold by the year 2016. In Japanese market in particular, use of R410A have already been phased out.
Introduction of new HFO blended refrigerants, for example, blended with R1234yf or R1234ze(E), are expected to further contribute to the reduction of global warming. To check the reports that adding HFO refrigerant to R32 makes performance superior to R32, we conducted drop-in test to confirm the performances of 2 types of HFO blend refrigerants, R32/R1234ze(E)(70/30) and R32/R125/R1234yf (67/7/26):R452B. We compared the results from experiment and system simulation. As a result, R452B indicated higher COP than R410A, but lower than R32. This may be attributed to the increase in pressure loss that caused the degradation although this investigation using system simulation proved to be effective for prediction. From now on, we will continue to utilize this system simulation to accelerate exploration for next generation refrigerants.