Storage of Heat Excess from a Plastic Tunnel in a Rock—Bed Accumulator: Tomato Yield and Energy Effects

The paper presents the outcome of experimental research which was carried out in real conditions on tomato production in a plastic tunnel. Plastic tunnels with dimensions of 9 × 30 were covered with double PE plastic with an air insulation layer. Devices responsible for microclimate inside the facility were controlled with a climate computer. Two facilities where tomatoes were cultivated in the April–October cycle were analysed. A rock-bed accumulator was installed in one of the tunnels. The system of heat accumulation comprised elements which suck hot air from the upper part of the facility and the system which distributes heated air to the plant zone. Heat storage in the accumulator was performed with the use of an autonomous control system. This system, based on the algorithm, controlled both the charging and discharging process including the set parameters of the microclimate inside the facility. The energy effects (the amount of heat, parameters of the microclimate inside the tunnel), issues concerning drying and humidification of air pressed through the stone bed and the amount and quality of tomato yield were analysed. The effects of accumulation were calculated into fuel consumption and the reduction of hazardous substance emitted to atmosphere was calculated. Moreover, the obtained effects in the form of plant yield were presented.