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In this paper, heat loss is precisely computed by a proposed code considering different climates. Estimating the costs of different central heating system, unit heaters were selected as the most feasible system. Finally, considering the heating capacity and unit heater's dimensions a computational fluid dynamics model was developed to find the optimized configuration of unit heaters in a typical greenhouse. Using this model, the required thermal load for a greenhouse based on the daily temperature of Arak city in 2017 was computed with a smart control system. It was found that savings in energy consumption were approximately 5447 m3 of natural gas each year.

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Dust flames are associated with two-phase combustion phenomena where flame characteristics depend on interactions between solid and gas phases. Since organic dust particles can be effectively utilized in energy production systems, investigation of this phenomenon is essential. In this study, an analytical model is presented to simulate the combustion process of moist organic dust. The flame structure is divided into three zones: preheat zone, reaction zone, and postflame zone. To determine the effects of moisture content and volatile evaporation, the preheat zone is also divided into four subzones: first heating subzone and drying subzone, second heating subzone, and volatile evaporation subzone. The results obtained from the presented model are in reasonable agreement with experimental data for lycopodium particles. An increase in moisture content causes a reduction in burning velocity owing to moisture evaporation resistance. Consequently, the effects of some important parameters, like volatilization temperature, volatilization Damköhler number and drying Damköhler number are investigated. In special cases, like high moisture content, low volatilization temperature, and high drying resistance, the second heating subzone is omitted.

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