Energies Renouvelables & Systèmes Energétiques

University Hassan II of Casablanca Faculty of Sciences AÏN CHOCK Departement of Physic[pic 1][pic 2]

Master Spécialisé

Energies Renouvelables & Systèmes Energétiques

SIZING OF A CANADIAN WELL

Presented by :        Encadred by :

REFFASS Youssef        Mr . FARAJI

HEDDAR Hamza

BOUAZZAOUI Youssef

El Bouchtaoui Iliass

SAMTI Ayoub

 college year :  2022/2023[pic 3]

1. INTRODUCTION

In a context where buildings are constructed to be more airtight and more energy efficient, the supply of fresh air through a central ventilation system and a heat recovery ventilator (HRV) now represents the main air supply of a residential building. It is therefore interesting to reduce as much as possible the energy consumption linked to the heating and cooling of this fresh air. One of the recommended methods is the use of air-source heat pumps, which by their mode of operation allow more energy to be brought into the building than what they consume. On the other hand, the coefficient of performance (COP) in heating of an air heater drops when the outside temperature drops, which can then make them less efficient than heating by electric baseboards or by gas burner. In addition, the performances announced by fuel cell manufacturers are for warmer climates and are therefore sometimes erroneous in our climate. The advertised performance also only briefly takes into account the phenomenon of icing that appears when the outside temperature approaches the freezing point and which can reduce actual seasonal heating performance by nearly 15% (Vocale, Morini and Spiga, 2014).

Thus, any change that can make the fuel cell operate advantageously at lower outside temperatures results in an energy gain. Recently, FC manufacturers have developed models that can operate in temperatures as low as -30°C. On the other hand, these models often offer less advantageous real seasonal efficiencies due to partial load operation when the ambient temperature is higher. It is therefore interesting to study the combination of a system that can increase the temperature of the air at the outdoor coil of the FC in heating mode. As such, the air-ground exchanger (ÉAS), also known as the Canadian well or the Provençal well, is an avenue to study. With a low energy input from a fan, the air can be preheated (or pre-cooled, depending on the season) by passing through a tube buried in the ground, thus taking advantage of the thermal inertia of the ground.

The purpose of this project is therefore to demonstrate the interest of the combination of an EAS and an air fuel cell in order to increase the performance of the latter. More precisely, the performance of the system will be quantified by the savings in electrical energy, the improvement of the COP of the heat pump and heating and cooling and the reduction in the use of auxiliary heating at low ambient temperature and during the defrosting of the unit. 'evaporator.

A review of the relevant literature will first be presented to align the project with previous studies. Subsequently, the proposed system will be presented in order to understand its operation, then each component will be detailed to obtain an overall design of the system. The efficiency of the system will then be studied through energy simulations carried out with the TRNSYS software which will make it possible to judge the possible energy gains. A parametric study will then make it possible to study the influence of the various parameters of the construction of an EAS. Everything will be completed by a financial analysis that will make it possible to judge the economic viability of this type of project

1. DEFINITION

Geothermal energy is first and foremost the science that studies the internal thermal phenomena of the terrestrial globe. By extension, this term also refers to all the technical applications that make it possible to exploit geothermal energy sources.

Geothermal energy, from the Greek geo (earth) and therm (heat). It is the science that studies the internal thermal phenomena of the terrestrial globe and the techniques to be used.

In reality, the accumulated heat is exploited, stored in certain parts of the subsoil (water tables) by making one or more deep boreholes.

The earth is heated or cooled at the same time by: the sun, the air, the wind and the rainwater. So the ground constitutes a reservoir which permanently receives energy in the form of calories. The temperature gradient is not the same between the center of the earth and the terrestrial layer, where one can reach several hundred degrees for shallow depths and vice versa.

The deeper you drill into the earth's crust, the higher the temperature. On average, the temperature increase reaches 20-30 degrees per kilometer. This thermal gradient depends

much more of the region of the globe considered. It can vary from 3°C per 100 m (sedimentary regions) up to 15°C or even 30°C (volcanic regions, rift zones like in Iceland or New Zealand).

1. Historical

The first traces of the use of geothermal energy by man go back to a distant period, throughout the history of civilizations, the practice of thermal baths has multiplied and for a century, industrial exploitations have developed to electricity generation and district heating.

If we have to find distant origins for the use of geothermal energy, why not ask ourselves, like the historians of prehistory, what role did hot springs play in humanity's resistance to the last glaciations? The oldest remains related to the Earth's heat, found at the Niisato site in Japan, are carved volcanic stone objects (tools or weapons) dating from the Third Ice Age, 15 or 20,000 years ago. Volcanic regions were therefore, very early on, poles of attraction, due to the existence of fumaroles and hot springs that could be used for heating, cooking food or simply bathing.

1. Canadian wells

The enthusiasm for the Canadian/Provençal well in Germany and the interest it arouses in France has given rise to a large quantity of documents of varying relevance. Those used in this study are guides or works (CETIAT, 2008. , HERZOG, 2007. , DERDERIAN, 2008. , LOYAU, 2009. [102]), installers' and builders' sites (REHAU, EOLE, ALDES, SODIELEC…) and the sites of various organizations such as ADEME or the Ardennes Local Energy Agency.

1. Principle of operation and description of the system

The principle of the Canadian/Provençal well is to circulate new ventilation air in a buried duct using a fan, before blowing it into the building. In winter, the air warms up as it travels underground. The heating needs related to the renewal of air in the premises are then reduced and the frost protection of the building can be ensured. The work is then called Canadian well. In summer, the outside air takes advantage of the coolness of the ground to cool down and arrives in the building during the day at a temperature lower than the outside temperature. The work is then called Provençal well. In the remainder of the document, Canadian/Provençal wells will be referred to as Canadian wells only. The diagram in Figure 1 shows an example of a Canadian well with its four main components.

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