CO2 REFRIGERATION SYSTEM

FOR A GREENER FUTURE

INTRODUCTION

Is CO₂ Better for the Environment?

The perception of CO₂ gas has been long regarded as the significant contributor to global warming. This association arises from the the continuous consumption of fossil fuels like oil and coal in our daily lives, leading to emissions from vehicles and power generators.

So how is CO₂ refrigeration system actually good for the environment?

The environmental advantage of CO₂ refrigeration system becomes evident when considering its impact through the lens of Global Warming Potential (GWP). In this regard, CO₂ demonstrates a remarkably low GWP of 1 as compared to the mainstream Hydrochlorofluorocarbon (HCFC) or Hydrofluorocarbon (HFC) gases like R22 or R404A, which possess significantly higher GWP of 1810 and 3920, respectively.

The transition from the use of Fluorocarbon gas (F gas) to CO₂ is strongly recommended as one of the most effective and sustainable strategies to lower the environmental impact. This recommendation stems from the fact that CO₂ within our refrigeration systems operates in a closed circuit because of this, they system itself does not contribute to the emission of any CO₂, thereby aligning with environmentally conscious practises.

how does it work?

Simple Direct Expansion (DX) System

The diagram provided severs as a representation of a standard refrigeration system setup commonly used in cold rooms. The CO₂ refrigeration units are positioned outdoors while the evaporators are situated inside.

In this system, liquid CO₂ refrigerant is cooled to about 0°C within the refrigeration unit and then sent to expansion valves (EV) inside the cold rooms. These valves turn liquid CO₂ into CO₂ gas through evaporation. The CO₂ gas is then used to cool the storage are by blowing chilled air. This system known as "Direct Expansion" is straightforward and effective for cold rooms.

The diameter of the piping used for the distribution line (liquid) and suction line (gas) are smaller and it offers several advantages. This includes easy installation, reduced utilisation of space and lower piping pressure.

Application

The chilled CO₂ refrigerant is delivered directly to the evaporators (unit coolers) installed at cold rooms. Ideal for room temperature set at -25°C, max at -45°C