Wind energy usage for building heating applying hydraulic system

Abstract

The most ordinary way to use wind energy for building heating needs is to convert mechanical wind energy into electrical energy and to use electrical energy for heating. Though there are ways to convert mechanical wind energy into thermal energy without transitional energy conversion – hydraulic systems can be implemented for this purpose. Wind rotor gives rotational motion to the pump of hydraulic system and it creates fluid circulation in the hydraulic system. A part of liquid mechanical energy due to hydraulic resistance of the system converts into the thermal energy when the liquid circulates in the close hydraulic loop and it heats up the liquid that can be used for heating purposes. Different hydraulic valves can be integrated in the hydraulic system and they can work as the load-regulating component of the system. The purpose of the study was to adjust the hydraulic load to the optimal value in order to generate a maximum amount of thermal energy. During the study, the work of a wind rotor was simulated by an electric motor, rotated at different frequencies (without feedback). The hydraulic system consisted of a gear pump, an adjustable load regulation valve, pipes, oil tank, sensors for measuring motor shaft rotational speed, oil temperature and pressure. The experiments were carried out at different electromotor speeds: 12.5, 17.5 and 22.5 Hz, and for different oil temperatures in the range of 20 to 50 °C. The relationship between the opening degree of the valve and the amount of generated thermal energy was determined. The study showed that wind energy usage can cover a significant part of the building’s thermal energy needs at the same time reducing pollution and the usage of the fossil fuel for heating purposes.