Modélisation énergétique de serres de petite taille : Amélioration, calibration et validation d’un modèle de simulation thermique dynamique développé avec TRNSYS

Abstract

Due to the unfavourable climate for agriculture in Quebec, producers and communities often turn to small-scale greenhouses to extend their growing season. However, maintaining optimal growth conditions in a greenhouse quickly becomes energy-intensive, posing a major challenge for profitable greenhouse operations.Greenhouse energy modelling is a prevalent tool for studying greenhouse energy performance. However, there is currently no reliable energy model with extensive validation to confidently assess the energy performance of smallscale greenhouses in the Quebec climate. This thesis aims to develop a validated greenhouse energy model for a typical small-scale greenhouse in a cold climate. The model is created using TRNSYS, a building performance simulation tool, with detailed energy modelling components and a user-defined crop model. The model is calibrated to fix uncertain parameters. A sensitivity analysis is used first to identify sensible uncertain parameters, followed by a multi-stage automated calibration. The automated calibration method uses a multi-objective genetic algorithm to adjust the uncertain parameters, calibrating the model for the measured indoor air temperature and relative humidity. The model performed well during the free-floating and ventilated stages (56 days) with a combined root mean square error (RMSE) of 1.6°C for the indoor temperature and 8.3% for the relative humidity. Then, the calibrated model is validated to assess its applicability using two additional datasets. For all the cases, comparing the simulation results with indoor environment measurements resulted in an RMSE of less than 2°C for air temperature and less than 10% for air relative humidity: these values compare favourably to the literature. The model achieved a 3.7% mean relative error in estimating monthly energy consumption for a minimally heated greenhouse. Given these results, the model is deemed sufficiently accurate and applicable for future investigations. The TRNSYS model, with its versatility, provides the opportunity to explore various construction configurations, systems, and operating modes for greenhouses. This opens up diverse possibilities for assessing and enhancing the energy performance of smallscale greenhouses in Quebec.

Date	16 Apr 2024
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Didier Haillot (Supervisor) & Danielle Monfet (Co-supervisor)