Effect of Heating System Position on Vertical Distribution of Crop Temperature and Transpiration in Greenhouse Tomatoes

• Published in: Journal of agricultural engineering research Vol. 75; no. 1; pp. 57 - 64
• Main Authors: Kempkes, F.L.K., Van de Braak, N.J., Bakker, J.C.
• Format: Journal Article
• Language: English
• Published: London Elsevier Science Ltd 01.01.2000; Academic Press
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; CALENTAMIENTO; CHAUFFAGE; CONSOMMATION D'ENERGIE; CONSUMO DE ENERGIA; CONVECCION; CONVECTION; ECHANGE THERMIQUE; ENERGY CONSUMPTION; ENERGY REQUIREMENTS; EVAPORACION; EVAPORATION; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; GREENHOUSES; HEAT TRANSFER; HEATING; HEATING SYSTEMS; Institute of Agricultural and Environmental Engineering; Instituut voor Mechanisatie, Arbeid en Gebouwen; INVERNADEROS; LATENT HEAT; LEAF AREA; LYCOPERSICON; MODELE DE SIMULATION; MODELOS DE SIMULACION; PIPES; Protected cultivation; SERRE; SIMULATION MODELS; Soilless cultures. Protected cultivation; SUPERFICIE FOLIAR; SURFACE FOLIAIRE; TEMPERATURA; TEMPERATURE; TRANSFERENCIA TERMICA; TRANSPIRACION; TRANSPIRATION; TUBERIA; TUYAU; Latent heat; Temperature distribution; Energy consumption; Heating equipment; Agricultural facility; Protected cultivation; Plant leaf; Experimental study; Leaf area; Convection; Transpiration; Vegetable crop; Dicotyledones; Angiospermae; Lycopersicon esculentum; Spermatophyta; Solanaceae; Simulation model; Greenhouse; Solar radiation; Heat transfer
• ISSN: 0021-8634; 1095-9246
• DOI: 10.1006/jaer.1999.0485

The presence of independently controllable heating systems enables local crop heating to influence the crop development. The position of the heating system also influences energy consumption. A simulation model was developed to predict the effects of the heating system on the vertical distribution of crop temperature and transpiration in a greenhouse tomato crop. The model is based on physical transport processes (radiation, convection and latent heat transfer). The radiation exchange factors between heating pipes, crop layers, soil and roof were determined as a function of the vertical distribution of leaf area and position of the heating systems. Experiments were performed to evaluate the model under a range of ambient nighttime conditions, including differences in leaf area index and position of the heating system and its temperature. Nighttime temperature differences in the tomato crop appeared to be small and the local effects on leaf temperature of the heating pipes, is rather limited. The energy requirement increases by 5–10% with overhead heating pipes. The simulation model is well suited to predict crop temperature distribution as a function of the position and temperature, of the heating pipes, as well as the vertical distribution of crop evaporation.