İklimlendirme sistemlerinde R22 yerine R442A kullanılmasının enerji parametrelerine etkisinin incelenmesi

Yıl 2016, Cilt: 7 Sayı: 3, 551 - 558, 01.12.2016

Atilla G. Devecioğlu Vedat Oruç Uğur Berk Sertaç Ender

Öz

Bu çalışmada buhar sıkıştırmalı iklimlendirme cihazında R22 soğutucu akışkanı yerine R442A kullanılması
deneysel olarak incelenmiştir. Sistemde sadece kompresör yağı değiştirilmiştir. R22 ile çalışırken mineral
yağ kullanılırken R442A ile yapılan çalışmalarda sentetik polyol ester (POE) yağ kullanılmıştır. Deneyler
aynı çalışma şartları altında üç farklı çevre sıcaklığı (25°C, 30°C, 35°C) için tekrarlanmıştır. Deneyler
sonucunda soğutucu akışkanlara ait kütlesel debi, soğutma kapasitesi, COP ve sıkıştırma oranı tespit
edilmiştir. Tespit edilen bu enerji parametrelerinin mukayesesi yapılmıştır. Sonuçlarda R22’nin soğutma
kapasitesi ve soğutma performans katsayısı R442A’ya göre bir miktar yüksek tespit edilmiştir. R22’nin
elektrik tüketimi ise R442A’dan düşük tespit edilmiştir. Ozon yok etme potansiyeli sıfır olan ve R22’nin
enerji parametrelerine yakın değerlere sahip R442A’nın orta vadede R22 yerine iklimlendirme sistemlerinde
kullanılabilecek uygun bir soğutucu akışkan olduğu söylenebilir.

Anahtar Kelimeler

İklimlendirme sistemleri, R22, R442A, COP

The investigation of the effect on the energy parameters using R442A instead of R22 in air-conditioning systems

Öz

The refrigerant of R22 is widely used in the airconditioning
systems. However this refrigerant
would be gradually removed to use as per Montreal
protocol since it has a serious potential of ozone
depletion. According to EU regulations,
refrigerants, which do not deplete the ozone layer,
having low global warming potential (GWP) should
be preferred in both air-conditioning and
refrigeration systems. Obviously, the gas leakages
may occur from the available devices operating with
R22 as a result of their maintenance and installation
elsewhere. Hence, R22 currently utilized in the
refrigeration systems should be replaced with
refrigerants having ozone depletion potential (ODP)
of zero in order to protect the ozone layer.
Although the air-conditioners of small capacity are
widely used, the effect of different alternative
refrigerants (especially R442A) on the energy
parameters such as COP, cooling capacity, and
power consumption etc. is not well known. Some
studies can be found in the literature on refrigerants,
which are not ozone-depleting, as alternatives for
R22 in the air-conditioning systems. The refrigerants
such as R407C and R410A that do not deplete the
ozone layer are used as an alternative for R22 in the
air-conditioners by implementing some
modifications in the system. It was remarked in the
previous studies that the refrigerants should be
preferred as alternatives to HCFC-22. The related
investigations are still continuing due to the
significance of the topic.
The literature survey has pointed out that there are
two possible methods to use the alternative
refrigerants in air-conditioning or refrigeration
systems. In the first one, the new refrigerant is
directly charged into the system instead of R22
without making any constructional modification
which is called as “drop-in” process. On the other
hand, the second method known as “retrofitting” in
which changing compressor oil and/or modifying
some elements of the system depending on the
refrigerant type would be necessary.
In this study, an experimental investigation was
carried out using R442A as a substitute for R22 in a
vapour compression air-conditioning system. A
split-type air-conditioning device with a cooling
capacity of 2.05 kW and operating with R22 was
used as the experimental test unit. Although GWP
values of R22 and R442A are similar, their ODP
values are 0.05 and zero, respectively. Both
refrigerants have been classified as non-flammable
class by ASHRAE. Moreover, the thermodynamic
properties of the tested refrigerants were seen to be
in the similar range of magnitude.
The compressor oil has only been changed in the
experimental system such that while mineral oil was
used for R22, synthetic Polyolester oil (POE) was
utilized for the case of R442A. The experiments were
conducted under the same conditions for each
refrigerant at three different ambient temperatures,
Ta (25°C, 30°C, 35°C). Basically, measurements of
mass flow rate, pressure and temperatures in the
system were accomplished for the experimental
work. The enthalpy values of the refrigerants have
been subsequently determined according to the
measured data through Refprop software. The
compression ratio, cooling capacity, power
consumption of the compressor, and coefficient of
performance (COP) were evaluated in the
investigation. Then the comparison of these
determined energy parameters for both refrigerants
were performed. It was seen that mass flow rate of
R442A was smaller than that of R22 at the
considered ambient temperatures. The evaporation
temperature, Te had greater values for higher Ta
cases regardless of refrigerant type while Te for R22
was lower compared to R442A. The compression
ratio, PH/PL increased with Ta and it was larger for
R442A case. The experimental results demonstrated
that the cooling capacity and COP values of R22
were somewhat greater in comparison with R442A.
Furthermore, the power consumption of the
compressor was lower in the case of using R22. In
addition, the COP was considerably reduced as a
result of increasing Ta for both refrigerants.
According to the experimental results of the present
investigation R442A should be a suitable refrigerant
in the medium term that can be alternatively utilized
in the air-conditioning systems considering its zero
ozone depletion potential and similar energy
parameters of R22.

Anahtar Kelimeler

Air-conditioning systems, R22, R442A, COP