In this article the using of thermosiphon solar collectors for system air heating of premises of passive houses was examined. The research determination the air velocity and air temperature in the space of experimental module were conducted. According to the research the field of temperature and air velocity in the space of the experimental module for different output of thermal solar radiation were built. The main factors that affect the value of speed and temperature of the internal air were identified. It was established that the presence of spiral turbo baffles increases the thermal output of thermosiphon collector to 15%, and the rate of heated flow to 17%
Abstract. 1 The promising environmentally friendly solar heating systems are based on the combined solar collector, in which the absorber made of constructive material of low-energy house was described. The usage of the combined absorber with an external protection of lowenergy house ensures sufficient efficiency of combined solar collector and reduces its cost. Three-factor planning matrix with the factors interaction was developed. Analytical and graphical dependencies of efficiency of the combined solar collector with a transparent coating and without it on the angle of incidence and intensity of heat flow were shown. The efficiency of transparent coating which protects the absorber of solar collector was researched. Ecological effect of using the combined solar collector was calculated.
The article is devoted to decision of actual task of air distribution efficiency increase due to swirled air jets application. The aim of the paper is investigation of swirled air jets, analytical dependencies obtaining for determination of the air velocity attenuation coefficient, aerodynamic local resistance coefficient and noise level from the twisting plates inclination angle; optimization of the twisting plates inclination angle of the air distributor. It has been established that increase of the angle results in the air velocity attenuation coefficient increase and results in decrease of the noise level and resistance coefficient of air distributor. The optimum angle of the plates is determined considering aerodynamic, noise and energy aspects and equals 36°.
The most common ventilation system in residential buildings in Ukraine is natural ventilation. In recent years, due to increased tightness of structures, an increase in the content of synthetic finishing materials in them, the quality of microclimate parameters deteriorated. One of the measures to improve the parameters of indoor air in residential buildings is the use of mechanical inflow and exhaust ventilation system. In this article the regulatory documents concerning the design of ventilation systems in Ukraine and Estonia and the requirements for air exchange in residential buildings are considered. It is established that the existing normative documents in Ukraine are analogous to European norms, which allow design the system of ventilation of residential buildings according to European standards. However, the basis for the design of ventilation systems in Ukraine is the national standards, in which mechanical ventilation, unfortunately, is provided only for the design of high-rise buildings. To maintain acceptable microclimate parameters in residential buildings, it is advisable for designers to apply the requirements for designing ventilation systems in accordance with European standards.
The data of geological exploration works carried out in Lviv region allow us to speak about the significant energy potential of geothermal waters in this region. At present, six bore-wells have been discovered in which the temperature of geothermal waters reaches 120oC at a depth of more than 3000 m. However, today the energy potential of geothermal waters of Lviv region is not used for both technical and economic reasons. This article, analyze the most common schemes for the use of geothermal resources based on the experience of countries with developed geothermal energy For geothermal systems with parameters typical of Lviv region, the greatest effect can be achieved by using doublet systems, which consist of two wells: suction and injection, and the resulting heat energy can be used to heat a wide group of consumers.
Purpose. To increase the energy and economic efficiency of heating coal mines with infrared heaters through energy saving measures, taking into account the dynamics of the discount rate. To achieve this goal, the task was to conduct an energy audit of the heating system of the mine during its reconstruction according to an improved method, taking into account the dynamics of the discount rate and measures that are not feasible at the same time. Methodology. When using infrared heating systems, local heating of the working area is provided. As a result, the necessary temperature conditions in the mines are maintained and there is a possibility of creating a local microclimate. A multifactorial experiment was performed and the research results were graphically and analytically described. Furthermore, the method of energy audit, taking into account the effect of complex interaction of factors and the dynamics of the degree of discount, is applied. Findings. According to the results of the experiment, a nomogram of the temperature regime of the irradiation area with an infrared heater was constructed, which was approximated by the analytical dependence. The optimal profit from the introduction of energy-saving technologies during operation is EUR 379.2 under the following conditions: replacement of the heating system from stationary to variable with automation; installation of a different number of infrared heaters NL-12R with power Q 1200 W each; application of the effect of complex interaction of factors. Originality. The conducted energy audit of the radiant heating system with the use of infrared heaters during the underground reconstruction showed that non-stationary heating is efficient because it saves energy and has the lowest payback period. Practical value. The expediency of using infrared heaters in variable mode in both energy and technical and economic aspects has been proved. These measures will provide comfortable conditions in the mine and have a significant economic effect.
In all sectors of the national economy of Ukraine, issues of energy efficiency and saving of fuel and energy resources are important. Legislative changes in the branches and scientific developments of scientists allow reducing the energy dependence of Ukraine on imported fuels. One of the energy-saving measures for the transportation of natural gas is the use of a vortex tube for heating natural gas at gas distribution stations. Natural gas is heated before the process of reducing it in the gas pressure regulator to prevent the formation of crystalline hydrates within the gas pressure regulator. The complexity of the implementation of such a measure is the explosion of the fire hazard of natural gas, which makes it impossible to conduct a sufficient number of experimental studies to determine the required characteristics of the vortex tube for operation at the gas distribution station. Therefore, for the wide introduction of a vortex tube at gas distribution stations, a generalized mathematical model should be developed that would allow describing the process of heating the vortex tube of a working gas with different thermophysical parameters. In this paper, the thermodynamic and physical bases of the process of heating the compressed gases in the vortex tube are considered and the main parameters that influence the operation of the vortex tube are determined. The mathematical model of the process of heating the natural gas in a vortex tube is scientifically substantiated and improved. To improve the mathematical model of the natural gas heating process in the vortex tube, loss of dynamic pressure was determined on each characteristic section of the vortex tube and the degree of heating therein. Moreover, the mathematical model proposed by the authors allows us to determine the thermal power of the vortex tube and the amount of heat needed to heat the working gas in the vortex tube.
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