Feasibility of winter cultivation of fruit vegetables in a solar greenhouse in temperate zone; experimental and numerical study

• Published in: Solar energy 2022-02, Vol.233, p.18-30
• Main Authors: An, Chol-Ho, Ri, Hyo-Jong, Han, To-Uk, Kim, Sok-Il, Ju, Un-Song
• Format: Article
• Language: English
• Subjects: Air temperature; Boundary conditions; CFD; Cultivation; Energy equation; Enthalpy; Feasibility studies; Fruit cultivation; Fruit vegetable; Fruits; Greenhouses; Leaves; Mathematical models; Microclimate; Microclimate model; Night; Numerical models; Sensible heat; Solar energy; Solar greenhouse; Temperate zones; Temperature; Transpiration; Vegetables; Winter
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2022.01.024

[Display omitted] •Clarification of DPG performance during winter night by experiment and simulation.•Unsteady CFD modeling of microclimate in cropped greenhouse.•Applying a new sensible heat term to energy equation for cropped greenhouse.•Improvement of computational modeling of complex biological system.•Extension of ANSYS FLUENT’s (or CFD) capability by UDF coding. Feasibility of winter-cultivation of fruit vegetables was studied in a solar double plastic covered greenhouse in a temperate zone. An experment for 24-hour-course including a cold night was performed and an unsteady numerical model was developed to predict microclimate in the greenhouse. Sensible heat term with separated air and leaf temperatures was applied to energy equation. Modeling of plant transpiration and outside boundary conditions were accomplished by applying a user defined function added to FLUENT. Comparisons between measured and simulated air/leaf temperatures showed a good agreement for the 24-hour-course. Simulations were performed to examine the feasibility of ensuring the inside air temperature higher than 12 ℃ (the lowest temperature limit for fruit vegetables) in inner greenhouse during the coldest winter night. When covering both the outer and inner films with quilts, it could overcome the night with the lowest outside air temperature of −18.6 ℃. A necessity of heat shield for north wall outside surface was confirmed. Results show that the double plastic covered greenhouse can be a good passive solar system for winter-cultivating the fruit vegetables in some temperate zones.