出版社:Faculty of Humanities, Kaunas University of Technology
摘要:Recent years brought many changes, which accelerated the development of different communication approaches and technologies. Nowadays, wireless technologies become the accelerators for a wide range of new applications. This paper focuses on the latest evolution of the promising wireless communication technology IQRF. For this aim, an in-depth analysis together with experimental measurements and simulations are provided. We provide original results in selected indoor and outdoor scenarios, in which the important communication parameters and technological limitations are highlighted. Last but not least, the application field of IQRF is established together with a comparison with other relevant technologies.
其他摘要:This paper proposed an active greenhouse heating system which focused on the problem of crop growth under extreme cold weather. At the beginning, heat transfer process of heating system was analysed based on thermal equilibrium theory. Radial and axial heat conduction mathematical analysis model of temperature control system were established respectively. Then, numerical simulation of temperature distribution was carried out by means of finite element method (FEM) software. When the effective operation range (later referred to as Qf) was defined with soil temperature more than 15 °C at 20 cm underground, opening temperature of heating system should be no less than 28 °C. Simulation results show that an increase of air inlet temperature by 2 °C could extend axial effective operating range by 2.4 m–2.8 m. Later, field test was implemented in greenhouses which located in Changping district, Beijing. Finally, compared with simulation data, the field testing data shows that the perturbation law of heating system heat transfer process on shallow and deep layer soil temperature is consistent with theoretical analysis. The numerical simulation could help to guide the temperature control of greenhouse. DOI: 10.5755/j01.eie.25.2.23205
关键词:Active greenhouse heating system;Temperature control effect;Heat transfer analysis;Numerical simulation;ANSYS