Simple model and control strategy of earth-to-air heat exchangers
The worldwide energy situation forces industrialized countries to reduce their energy consumption, especially in the building sector, which makes up a high proportion of the total consumption. Techniques such as earth-to-air heat exchangers must therefore be developed and managed to meet this challenge. Yet earth-to-air heat exchangers provide better performance when linked to efficient control strategies.
GENERIC MULTI-OBJECTIVE OPTIMIZATION METHOD OF INDOOR AND ENVELOPE SYSTEMS' CONTROL
Growing concerns about energy consumption reduction and comfort improvement inside buildings make it necessary to optimize the control of any indoor and envelope thermal system. This study proposes a generic on-line method based on Genetic Algorithms for controllers’ setting optimization, with regard to two objectives: energy consumption and indoor discomfort. Consumption and discomfort prediction is used for performance assessment of individuals. Even though prediction is carried out by using physical modelling in this article, the method is doomed to use Neural Networks prediction in the future, in order to save development and simulation time. The method was assessed by being compared to off-line optimization, and showed similar performance.
Heat and water vapour transfer in a greenhouse with an underground heat storage system part I. Experimental results
Abstract A greenhouse with an underground heat storage system consisting of two layers of 0.125-m diameter PVC drain pipes buried 0.8 and 0.5 m deep, and a centrifugal fan circulating the greenhouse air, was tested with a classical crop rotation lettuce-tomato. Measurements of microclimatic and thermal performances of the system, including both sensible and latent heat transfers, were performed during two heating seasons. From our results, it can be concluded that this type of heat exchanger may be used in the South of France to maintain an average night inside-outside temperature difference of 7–9°C in March–April. Auxiliary heating to maintain the desired air temperature for these crops is only 20% of the whole heating season requirement. The measurements have shown the importance of water vapour exchanges which generate high humidity levels during the night-time and may enhance fungal diseases and physiological disorders on tomato plants (intumescences).