TRNSYS Simulation and Experimental Validation of Internal Temperature and Heating Demand in a Glass Greenhouse

Abstract

The energy demand in greenhouses is enormous, and high-performance covering materials and thermal screens with varying radiometric properties are used to optimise the energy demand in building energy simulations (BES). Transient System Simulation (TRNSYS) software is a common BES tool used to model the thermal performance of buildings. The calculation of the greenhouse internal temperature and heating demand in TRNSYS involves the solution of the transient heat transfer processes. This study modelled the temperature and heating demand of two multi-span glass greenhouses with concave (farm A) and convex (farm B) shapes. This study aims to investigate the influence of the different BES longwave radiation modes on greenhouse internal temperature in different zones and the heating demand of a conditioned zone. The standard hourly simulation results were compared with the experimental data. The results showed that the standard and detailed modes accurately predicted greenhouse internal temperature (the Nash–Sutcliffe efficiency coefficient (NSE) > 0.7 for all three zones separated by thermal screens) and heating demand (NSE > 0.8) for farms A and B. The monthly heating demand predicted by the simple and standard radiation modes for farm A matched the experimental measurements with deviations within 27.7% and 7.6%, respectively. The monthly heating demand predicted by the simple, standard, and detailed radiation modes for farm B were similar to the experimental measurements with deviations within 10.5%, 6.7%, and 2.9%, respectively. In the order of decreasing accuracy, the results showed that the preferred radiation modes for the heating demand were standard and simple for farm A, and detailed, standard, and simple for farm B.

Building Energy Simulation Model Application to Greenhouse Microclimate, Covering Material and Thermal Blanket Modelling: A Review

“…After validating the model, several other simulations are performed according to the set objectives of the study. For example, a study may want to investigated the influence of different thermal screens, the configuration of thermal screens in terms of the number of layers (multi-layer or single layer) and the type of material the thermal screen is made of (polyester, Luxous, or Tempa) on the heating or cooling energy requirement of a greenhouse (Rasheed et al, 2018c;Rasheed et al, 2020a;Rabiu et al, 2022). Figure 2 shows a typical BES model in the TRNSYS Simulation Studio.…”

“…Greenhouses also extend the cultivation period to achieve a high yield, protect plants from severe outdoor weather, reduce production costs and offer the possibility of off-season cropping (Lee et al, 2012;Akpenpuun and Mijinyawa, 2018;Ghoulem et al, 2019). Although greenhouse agriculture is cost-effective, as it reduces the number of agrochemicals and water required for the production processes of crops, greenhouse crop production is one of the high-energy-consuming sectors in large-scale agricultural production (Zhang et al, 2020;Rasheed et al, 2020a;Rabiu et al, 2022). This high energy consumption associated with large-scale greenhouse agriculture has caused an increase in research aimed at innovations and technological advancements.…”

“…Recent reports include developing building energy simulation (BES) to optimise greenhouse crop production and the design and manufacture of different thermal screens and cladding materials to conserve energy or shield crops from adverse climates. These methods promote energy savings without compromising crop growth, development and yield (Yano and Cossu, 2019;Rabiu et al, 2022).…”

“…Luo et al (2005) reported that energy balance and process-based climate simulation models and applications to greenhouse climate control were carried out in the 1980s. Since then, greenhouse climate simulations conducted by various researchers have contributed to the knowledge base on greenhouse climate, light transmission, ventilation, crop transpiration, photosynthesis, energy demand, thermal screening and cladding materials (Luo et al, 2005;Ahmad et al, 2017;Rasheed et al, 2018a;Rasheed et al, 2020b;Ahamed et al, 2020;Akpenpuun et al, 2021b;Akpenpuun et al, 2021a;Rabiu et al, 2022).…”

“…Crop cultivation in greenhouses increases from highaltitude and temperate regions to low-altitude and tropical and subtropical regions due to global warming (Kumar et al, 2009;Ogunlowo et al, 2021). Hence, manipulating or regulating the greenhouse air temperature to be the same as or very close to the outdoor air temperature in the hot season is required for successful crop production in the greenhouse (Akpenpuun et al, 2021b;Rabiu et al, 2022).…”