Heat and water vapour transfer in a greenhouse with an underground heat storage system part I. Experimental results

In this study, a new method of using the earth‐air heat exchangers to reduce energy consumption in buildings is discussed. The idea is to couple the EAHE with the condenser of a residential air conditioning system to enhance the effectiveness of the latter. Under the climatic conditions of high temperature in summer (south‐eastern region of Algeria), which can sometimes exceed 50 °C, what makes the heat exchange between the air conditioner and the external environment very difficult in addition to the problem of thermal comfort and the cost of energy consumption. Conducting a simulation by the TRNSYS software that allows to couple the model of the EAHE with the condenser of a residential air conditioner and connect the system with a building. The results show a clear reduction in the energy consumed by this system in connection with the direct use of the air conditioner and increase air conditioning efficiency, coefficient of performance, and energy efficiency rating. In this paper the Hollmuller model was ameliorated and the obtained results are in concord with it. The system is capable of resolving the problem of mal cooling of buildings by air conditioners under critical climate conditions, in addition to lowering the heat output of the condenser, and reducing its effect on the environment.

show abstract

“…The transfer of heat between the air and the casing can be expressed by the following relationship:

P_{air, tub} = S_{t u b} h_{c} (T_{a i r} - T_{t u b}) .

…”

Section: Model Of the Heat Exchanger Air‐groundmentioning

confidence: 99%

“…Heat transfer between the ground and the tube can be written as follows:

P_{sol, tub} = \sum_{i ε s o i l} S_{i} K_{i} (T_{s o i l, i, t - 1} - T_{t u b}) + \sum_{i ε t u b} S_{i} K_{i} (T_{s o i l, i, t - 1} - T_{t u b})

…”

Section: Model Of the Heat Exchanger Air‐groundmentioning

confidence: 99%

Contribution to the Study of the Reduction of Energy Consumption through the Exchanger Coupled Conventional Air‐Ground‐Air Conditioner. Application to the Building

Benhamza

Brima

Houda

et al. 2017

Heat Trans. Asian Res.

View full text Add to dashboard Cite

show abstract

“…As far as validation is concerned, it usually remains limited to a few hours or days and does generally only concern lab-operated installations. In this context, Hollmuller and Lachal [36] developed a revised version of the numerical model of Boulard et al [33,37]. In addition to the simultaneous sensible-latent heat transfer and fully 3D heat diffusion in soil, the new model account for various geometries, soil properties and border conditions, as well as frictional losses, possible water infiltration and control of airflow direction.…”

Section: Modelsmentioning

confidence: 99%

“…Some of them are limited to the description of only one ""typical"" pipe [14,18,[28][29][30][31]. Others deal with several parallel running pipes, with or without possibility to treat more complicated cases than steady state flow rate, homogenous and laterally adiabatic soils, or sole sensible heat exchange [32][33][34][35]. As far as validation is concerned, it usually remains limited to a few hours or days and does generally only concern lab-operated installations.…”

Section: Modelsmentioning

confidence: 99%

Experimental and numerical study of an earth-to-air heat exchanger for air cooling in a residential building in hot semi-arid climate

Khabbaz

Benhamou

Limam

et al. 2016

Energy and Buildings

108

View full text Add to dashboard Cite

Experimental and numerical study of an earth-to-air heat exchanger for air cooling in a residential building in hot semi-arid climate, Energy and Buildings http://dx.doi.org/10. 1016/j.enbuild.2016.04.071 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 3 ABSTRACT This work deals with an experimental and numerical study of an Earth-to-Air Heat Exchanger (EAHX) for air cooling, connected to a residential building located in Marrakech (Morocco) which climate is a hot semi-arid one. The EAHX consists of three parallel PVC pipes of 72 m length each and 15 cm inside diameter, buried at 2.2-3.2 m depth. Each pipe is equipped with a fan, which blows treated air into the building. The experimental study consists of summer monitoring of the EAHX via measurements of air temperature and humidity throughout the exchanger, as well as at its inlet and outlet to the building for two fixed values of the airflow rate. The experimental results show that the EAHX is a good semipassive system for air refreshment, as the recorded blown air temperature into the building is quasi-constant at 25 °C with air humidity around 40%, even though the outside temperature reaches more than 40 °C. Furthermore, the reduction of daily and annual air temperature amplitudes is characterized by an exponential drop as a function of pipe length. The characteristic length is found to be around 20m and 70m respectively for the daily and annual air temperature amplitudes reduction. Moreover, it is shown that the design guidelines from literature cannot straightforwardly be applied to an EAHX which is subject to meteorological disturbance from the upper surface and/or which is not operated all year round, for which numerical simulation with a validated models remains necessary. 1 EXPERIMENTAL AND NUMERICAL STUDY OF AN EARTH-TO-AIR HEAT EXCHANGER FOR AIR COOLING INOn the other hand, dynamic simulations of the EAHX using TRNSYS software (TYPE 460) were performed with one pipe or three pipes continuously running. Good agreement was found between the simulation and experimental results. Simulation results show that the EAHX can perform a maximum drop of air temperature as high as 19.5 °C and 18.3 °C respectively for an EAHX with one and three pipes. The achieving specific cooling capacity is 58 W/m 2 (one pipe) and 55 W/m 2 (three pipes) obtained for air temperatures of 25 °C and 26 °C respectively, at the EAHX outlet and 44.6 °C at its inlet.

show abstract

“…The constant soil temperature layer is an underground, widely existing, and easily accessible renewable energy resource (Yamamoto, 1966;1973;Takami and Uchijima, 1977;Takakura and Yamanaka, 1981;Kozai, 1985;Yamamoto, 1985;Hidaka et al, 2008). However, because of the low capacity of soil for heat storage and conduction, heat exchange with the constant soil temperature layer has been considered to be insufficient for controlling the temperature of the entire volume of air inside a greenhouse (Yamamoto, 1966(Yamamoto, , 1973(Yamamoto, , 1985Boulard et al, 1989a and1989b).…”

Section: Introductionmentioning

confidence: 99%

Application of the Constant Soil Temperature Layer for Energy-saving Control of the Local Environment of Greenhouse Crops. I. Local Control of the Ambient Environment of Strawberry

Miyoshi

Hidaka

Okayasu

et al. 2013

Environmental Control in Biology

View full text Add to dashboard Cite

Heat and water vapour transfer in a greenhouse with an underground heat storage system part I. Experimental results

Cited by 40 publications

References 6 publications

Contribution to the Study of the Reduction of Energy Consumption through the Exchanger Coupled Conventional Air‐Ground‐Air Conditioner. Application to the Building

Contribution to the Study of the Reduction of Energy Consumption through the Exchanger Coupled Conventional Air‐Ground‐Air Conditioner. Application to the Building

Experimental and numerical study of an earth-to-air heat exchanger for air cooling in a residential building in hot semi-arid climate

Application of the Constant Soil Temperature Layer for Energy-saving Control of the Local Environment of Greenhouse Crops. I. Local Control of the Ambient Environment of Strawberry

Contact Info

Product

Resources

About