Optimization of heating efficiency of buildings above underground coal mines by infrared heaters

Abstract

Purpose. To optimize the energy and economic efficiency of heating system of ground structures of coal mines with infrared heaters due to the rational choice of technical parameters of heating devices and their operating conditions, namely, the irradiation intensity of the floor q, thermal power of the heater Q, blackness degree of the floor surface and the height of installation H of infrared heaters. To achieve this goal, the task was to conduct theoretical and experimental studies on infrared heaters NL-12R of heating system of a building above underground coal mines during its thermal modernization. Methodology. At applying radiant heating systems, infrared heaters provide local heating of the working area of the buildings above underground coal mines. As a result, the necessary temperature conditions are maintained in the buildings above underground coal mines and there is a possibility of creating a local microclimate. A multifactorial experiment was performed taking into account the interaction of factors. The results of the study are presented in graphical and analytical forms. In addition, an analytical method was used to optimize parameters and operating conditions of the radiant heating system with infrared heaters NL-12R, and their number in the system of combined heating of buildings above underground coal mines is optimized. Findings. According to the experimental results, dependence of the relative floor temperature on the intensity of floor irradiation q, thermal power of the heater Q, blackness degree of the floor surface floor and the height H of infrared heaters location was determined. The results are presented in the form of graphs and nomograms, as well as approximated by their analytical equations. The annual economic effect of the optimal variant of combined heating system due to use the maximum number of infrared heaters NL-12R is 39.4 Euro/year provided that the installation of infrared heaters NL-12R with a power of Q = 1200 W in the number of 5 pcs. Originality. Optimization of energy and economic efficiency of heating system of buildings above underground coal mines by infrared heaters NL-12R, due to the rational choice of technical parameters of heating devices and conditions of their operation, was carried out by the analytical method. Practical value. Results of optimization of thermal and economic parameters of operation of the combined heating system of buildings above underground coal mines with installation of infrared heaters NL-12R with power Q = 1200 W proved the efficiency of combined heating of above-ground structures and the achievement of the annual economic effect of 39.4 Euro/year.

A New Approach to the Economic Evaluation of Thermomodernization: Annual Assessment Based on the Example of Production Space

“…In certain cases, the length of the analysis period may be determined by one of the interested parties, e.g., a bank or by law. In order for the thermal renovation option to be profitable, it is necessary that its Simple Payback Time is shorter than 15 years, and the Internal Rate of Return is greater than 8% [49,53]. Thus, in Poland and Ukraine, a period of 15 years is assumed for thermal modernization investments.…”