scholarly journals Development of a Building Energy Simulation Model for Control of Multi-Span Greenhouse Microclimate

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1236
Author(s):  
Adnan Rasheed ◽  
Cheul Soon Kwak ◽  
Wook Ho Na ◽  
Jong Won Lee ◽  
Hyeon Tae Kim ◽  
...  
Keyword(s):  
Simulation Model ◽  
Natural Ventilation ◽  
Winter Season ◽  
Weather Conditions ◽  
Building Energy ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Proposed Model ◽  
Heating Loads ◽  
Maximum Heating

In this study, we propose a building energy simulation model of a multi-span greenhouse using a transient system simulation program to simulate greenhouse microenvironments. The proposed model allows daily and seasonal control of screens, roof vents, and heating setpoints according to crop needs. The proposed model was used to investigate the effect of different thermal screens, natural ventilation, and heating setpoint controls on annual and maximum heating loads of a greenhouse. The experiments and winter season weather conditions of greenhouses in Taean Gun (latitude 36.88° N, longitude 126.24° E, elevation 45 m) Chungcheongnam-do, South Korea was used for validation of our model. Nash–Sutcliffe efficiency coefficients of 0.87 and 0.71 showed good correlation between the computed and experimental results; thus, the proposed model is appropriate for performing greenhouse thermal simulations. The results showed that the heating loads of the triple-layered screen were 70% and 40% lower than that of the single-screen and double-screen greenhouses, respectively. Moreover, the maximum heating loads without a screen and for single-, double-, and the triple-layered screens were 0.65, 0.46, 0.41, and 0.34 MJ m−2, respectively. The analysis of different screens showed that Ph-77 (shading screen) combined with Ph-super (thermal screen) had the least heating requirements. The heating setpoint analysis predicted that using the designed day- and nighttime heating control setpoints can result in 3%, 15%, 14%, 15%, and 40% less heating load than when using the fixed value temperature control for November, December, January, February, and March, respectively.

scholarly journals Impact of Natural Ventilation on the Thermal and Energy Performance of Buildings in a Mediterranean Climate

Buildings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 123 ◽  
Author(s):  
A. Moret Rodrigues ◽  
Miguel Santos ◽  
M. Glória Gomes ◽  
Rogério Duarte
Keyword(s):  
Natural Ventilation ◽  
Mediterranean Climate ◽  
Building Energy ◽  
Energy Performance ◽  
Energy Simulation ◽  
Wind Effect ◽  
Building Energy Simulation ◽  
Simulation Tool ◽  
Energy Performance Of Buildings ◽  
Ventilation Rates

Natural ventilation plays an important role on the thermal and energy performance of a building. The present study aims to analyze the natural ventilation conditions of a dwelling in a Mediterranean climate and their impacts on the thermal and energy performance using an advanced building energy simulation tool. Several multi-zone simulations were carried out. In the summer, the simulations were performed under free-floating conditions, whereas in the winter they were carried out under controlled temperature conditions. In the summer, ventilation scenarios with windows opened during certain periods of time and with or without permanent openings in the facades were analyzed. The existence of permanent openings proved to be an important factor of temperature control by lowering the average indoor zone temperatures during the day. Cross-ventilation also showed to be effective. In the winter, we simulated the existence or absence of permanent openings for room ventilation and their surface area. The results showed that the stack effect plays an important role in the ventilation and that in general it outperforms the wind effect. Sizing permanent openings according to the standard guidelines proved to be adequate in providing the expected ventilation rates on an average basis.

scholarly journals Development and Optimization of a Building Energy Simulation Model to Study the Effect of Greenhouse Design Parameters

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2001 ◽  
Author(s):  
Adnan Rasheed ◽  
Jong Lee ◽  
Hyun Lee
Keyword(s):  
Energy Demand ◽  
Natural Ventilation ◽  
Thermal Environment ◽  
Local Environment ◽  
Building Energy ◽  
Energy Simulation ◽  
Design Parameters ◽  
Building Energy Simulation ◽  
Roof Shape ◽  
Systems Simulation

Energy management of the greenhouse is considered to be one of the most important challenges of greenhouse farming. Energy saving measures need considered, besides applying energy supplying techniques. To address this issue, a model was developed to simulate the thermal environment of a greenhouse using a Transient Systems Simulation Program (TRNSYS 17) as a building energy simulation (BES) platform. The model was calibrated by modifying the input parameters to minimize the uncertainties obtained from the results. Nash-Sutcliffe efficiency coefficients of 0.958 and 0.983 showed good agreement between the computed and experimental results. The proposed model was used to evaluate the effects of greenhouse design parameters, including roof shape, orientation, double-glazing, natural ventilation, coverings and their thickness, on its energy conservation capacity. It was found that the most suitable design for a greenhouse located in Daegu (latitude 35.53° N, longitude 128.36° E) South Korea would be east-west (E-W) oriented, with a gothic-shaped roof and double-glazing of PMMA (Polymethylmethacrylate) covering. Natural ventilation reduced the inside temperature of greenhouse, thereby reducing the energy demand of cooling. The model developed can help greenhouse farmers and researchers make pre-design decisions regarding greenhouse construction, taking their local environment and specific needs into consideration.

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