Method and algorithm for calculating the system of gas-radiant heating of a cultivation facility with preheating of supply air

Abstract

The development of new technologies for maintaining the required microclimate in cultivation facilities presupposes the availability of an appropriate mathematical basis for determining the estimated thermal capacity of heating equipment and the parameters of the heating system, depending on environmental factors. The purpose of the research is to develop a software method for calculating the system of gas-radiant heating of a cultivation facility with preheating of the supply air. The calculation method is based on a system of interrelated equations of the thermal balance of the room, its enclosure and the soil surface. The solution, among other things, includes the utilization of heat from the combustion products of gaseous fuels, as well as radiant heat exchange with multiple reflection and self-radiation occurring between the surfaces of the soil and the fence. The software calculation method also takes into account the effect of moisture evaporation from the soil surface on the heat exchange processes occurring in the cultivation facility. Based on the developed software calculation method, the parameters of the operation of the gas-flue heating system of a cultivation facility are determined using the example of the industrial greenhouse “Farmer 7.5” (Russian Federation). Under the given initial conditions, the following main calculation results were obtained: the required thermal power of the gas infrared radiator is 68.7 kW; the thermal energy consumption required to heat the supply air before it is supplied to the room is 35.5 kW; the temperature of the preheated supply air is –11.6°C; the temperature of the inner surface of the fence is 18.6°C. The main assumptions adopted in the development of the calculation method are indicated. The prospects for further scientific research have been identified.