Mathematical modeling for greenhouse heating by using thermal curtain and geothermal energy

Abstract A thermal model has been developed for the heating of a greenhouse by using inner thermal curtain and natural flow of geothermal warm water through the polyethylene tube laid on its floor. The calculations were done for a typical production greenhouse with the climatic data in the central part of Argentina during winter period. From the energy conservations point of view, the greenhouse has been divided into three zones i.e., zone I (plants under thermal blanket), zone II (space under ceiling) and zone III (space between roof and ceiling). The model has been tested with the published experimental data of air temperatures in zone I and zone II of the greenhouse. From the results, it was observed that the temperatures of air surrounding the plant mass in zone I were maintained in the range of 14–23 °C during winter night and early morning resulting in the better growth of winter growing plants against the harmful freezing effects. The predicted values of air temperature both in zone I and zone II of the greenhouse obtained from the proposed model exhibited fair agreement with the published experimental values.

[1]  Constantinos A. Balaras,et al.  Passive solar agricultural greenhouses: a worldwide classification and evaluation of technologies and systems used for heating purposes , 1994 .

[2]  G. N. Tiwari,et al.  Design and optimization of a winter greenhouse for the Leh-type climate , 1986 .

[3]  D. R. Mears,et al.  THE EFFECT OF WARM ROOT ZONE TEMPERATURES ON GROWTH OF TOMATO AND POINSETTIA , 1981 .

[4]  T. L. Lyon,et al.  The Nature and Properties of Soils , 1930 .

[5]  Athanassios A. Argiriou,et al.  Design and operation of a low energy consumption passive solar agricultural greenhouse , 1994 .

[6]  P. Nelson,et al.  Greenhouse operation and management. , 1991 .

[7]  A. Gosselin,et al.  Effect of covering materials on energy consumption and greenhouse microclimate , 1996 .

[8]  G. Mihalakakou,et al.  Energy conservation in greenhouses with buried pipes , 1996 .

[9]  W. Beckman,et al.  Solar Engineering of Thermal Processes , 1985 .

[10]  C. Gauthier,et al.  Numerical simulation of soil heat exchanger-storage systems for greenhouses , 1997 .

[11]  K. Suen,et al.  Using shallow solar ponds as a heating source for greenhouses in cold climates , 1998 .

[12]  Ricardo Echazú,et al.  Greenhouse solar heating in the Argentinian northwest , 1997 .

[13]  M. N Bargach,et al.  Survey of thermal performances of a solar system used for the heating of agricultural greenhouses in Morocco , 2000 .

[14]  B. Liu,et al.  Daily insolation on surfaces tilted towards equator , 1961 .

[15]  Louis D. Albright,et al.  Rational Operation of Greenhouse Thermal-Curtains , 1980 .

[16]  M. A. Lara,et al.  Integrated thermal improvements for greenhouse cultivation in the central part of Argentina , 1999 .

[17]  A. Basçetinçelik,et al.  Influence of double plastic cover and thermal screens on greenhouse temperature, yield and quality of tomato , 1994 .

[18]  William A. Beckman,et al.  Solar Engineering of Thermal Processes, 2nd ed. , 1994 .

[19]  G. C. Bakos,et al.  Greenhouse heating using geothermal energy , 1999 .

[20]  Louis D. Albright,et al.  Analytical Determination of the Effect on Greenhouse Heating Requirements of Using Night Curtains , 1980 .

[21]  B. J. Bailey.  THE EVALUATION OF THERMAL SCREENS IN GLASSHOUSES ON COMMERCIAL NURSERIES , 1981 .

[22]  M.Dj. Pucar,et al.  Enhancement of ground radiation in greenhouses by reflection of direct sunlight , 2002 .

[23]  E. A. Arinze,et al.  Experimental and computer performance evaluation of a movable thermal insulation for energy conservation in greenhouses , 1986 .

[24]  J. Watmuff,et al.  Solar and wind induced external coefficients - Solar collectors , 1977 .

[25]  G. N. Tiwari,et al.  Modeling and optimal design of ground air collector for heating in controlled environment greenhouse , 2003 .

[26]  Amílcar Fasulo,et al.  Geothermal contribution to greenhouse heating , 1999 .

[27]  Kamal Abdel Radi Ismail,et al.  Thermal performance of a pcm storage unit , 1999 .

[28]  David R. Mears,et al.  Progress in movable blanket insulation systems for greenhouses , 1981 .

[29]  John W. Lund,et al.  World-wide direct uses of geothermal energy 2000 , 2001 .

[30]  S. Kurpaska,et al.  Optimization of greenhouse substrate heating. , 2000 .