Method of Experimental Investigation of Air-Cooled Condensers for Small Refrigeration Machines and Heat Pumps

Air-cooled condensers are widely used in commercial refrigeration machines and heat pumps. In the geographical regions with limiter water resources, the application of the air-cooled condensers is the only option for the systems for removing heat of the condensation process. The effectiveness of the air-cooled condensers depends on the internal factors such as increased amount of gases as well as external factors such as solid fouling. The result of growing the thickness of solid fouling is the following: increasing the sough level, decreasing the heat transfer coefficient, increasing the energy consumption and non-stable operation of the entire system. The analysis of the solid fouling is the useful information that should be included to the engineering calculations. It will help to estimate the operation parameters of the air-cooled condensers during the design as well as stability of operation of the refrigeration machine or heat pump. In the paper the experimental data of the air-cooled condensers with real solid fouling have been reported. The aircooled condenser is a component of one-stage refrigeration machine (BITZER, LH32E/2KES-0.5.) with R22 as the working fluid. The refrigeration machine was installed in a thermostatic room. The refrigeration capacity was imitated using an electrical heater. The experiment has been conducted for clean surface of the condenser as well for different levels of solid fouling and aerodynamic resistance modeled artificially. Using the obtained experimental data, the value of the refrigeration capacity, condensation heat rate, and power supplied for compressor and fan have been determined at different thickness of solid fouling and aerodynamic resistance. The experimental data showed that condenser is capable