Experimental study of the characteristics of an active heat reclaim unit under changing operating conditions

AIMS: This study aimed to analyze the active heat reclaim unit SNAB.065171.001-01 as the main heater of a ventilation system of a real object and to confirm the reliability of the calculation method using obtained experimental data.

MATERIALS AND METHODS: The experimental and computational methods included the technical and economic assessment of active heat reclaim units to determine the characteristics of the device under changing air flow rates and operating temperature conditions. The tests were performed at the laboratory of life support systems of the Faculty of Low-Temperature Energy at the St. Petersburg National Research University of Information Technologies, Mechanics and Optics. The equipment under study was installed in the existing ventilation system of the laboratory. The laboratory ventilation system was equipped with a stepwise air flow control system. The automation system enabled setting five fixed operating modes of the supply and exhaust fans without the possibility of smooth regulation within the flow range. Operational parameters and verified measuring instruments were used in measurements.

RESULTS: This paper describes the results of the determination of the refined nominal characteristics of performance, energy consumption, and conversion coefficient of the active heat reclaim unit. It also presents empirical coefficients necessary for the calculation of these characteristics under arbitrary operating conditions. The calculation methodology was verified through additional experiments. The relative deviation of the calculated conversion coefficient from the experimentally obtained one did not exceed 3% in all experiments.

CONCLUSIONS: The nominal characteristics of the built-in air heat reclaim unit SNAB.065171.001-01 were determined under real operating conditions. The results of the calculation of operational characteristics were compared with the experimental results.