Development of a thermostatic chamber for the performance testing of commercial compression refrigerators with traditional and low global warming potential fluids

Purpose This paper describes the design and implementation of a thermostatic chamber for the performance analysis of commercial vapor compression refrigerators. The thermostatic chamber and the refrigerators are equipped with a range of sensors to monitor respectively the temperature and humidity inside and outside the chamber and the thermodynamic conditions of the working fluid, i.e. temperature, pressure and mass flow rate, in the circuit critical points. The acquisition of sensor data and the refrigerator performance evaluation are provided thanks to a real-time and automatic interface developed adopting LabView© integrated development environment (IDE). The thermostatic chamber is adopted to compare the performance of refrigerants R407f and R410a as environmentally-friendly alternatives to the R404a, the current working fluid in the considered commercial refrigerator. Indeed, the Global Warming Potential (GWP) of R404a is approximately twice the value of refrigerants R407f and R410a. The purpose of the experimental campaign is verify whether the R407f and R410a refrigerants allow comparable thermodynamic performances to R404a without requiring substantial component replacements.   Design/methodology/approach The paper focuses on the description of the developed thermostatic chamber and the system setup for the experimental campaign of a commercial vapor compression refrigerator . The chamber is composed by a 180x180x220cm stainless steel climatic room with an internal volume of 5.12m3, properly insulated by 100mm of expanded polyurethane. The thermostatic chamber integrates the commercial vapor compression refrigerator, the refrigerant charging equipment and all the necessary sensors to monitor the environment conditions and evaluate the system performance. Originality/Value Global warming concerns have increased the efforts of the scientific community to identify alternative refrigerants in air conditioning systems with lower environmental impact and many results in the literature show their technical and economical feasibility. However, the introduction of these refrigerant alternatives in industrial products encounters some difficulties and, nowadays, several commercial refrigerators still adopt working fluids with a significant global warming potential. In this context, this paper presents the development and setup of a thermostatic chamber that can be adapted to real refrigerators to compare the thermodynamic performance of different refrigerants. An automatic control and data acquisition systems allow to test the thermostatic chamber in several technical configurations, i.e. ambient temperature and operating temperatures etc. The experimental campaign, applied to a commercial vapor compression refrigerator, compares the performance of environmentally-friendly refrigerants alternatives, i.e. R407f and R410a, to the currently adopted working fluid , i.e. R404a. The results may lead the company to launch onto the market a similar commercial refrigerator adopting a working fluid with a lower environmental impact.