Reducing Ventilation Energy Demand by Using Air-to-Earth Heat Exchangers

2013 ◽  
pp. 731-742 ◽  
Author(s):  
Hans Havtun ◽  
Caroline Törnqvist
Keyword(s):  
Heat Exchangers ◽  
Energy Demand

scholarly journals Application and Design Aspects of Ground Heat Exchangers

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2134
Author(s):  
Luka Boban ◽  
Dino Miše ◽  
Stjepan Herceg ◽  
Vladimir Soldo
Keyword(s):  
Renewable Energy ◽  
Heat Exchangers ◽  
Geothermal Energy ◽  
Energy Demand ◽  
Design Parameters ◽  
Direct Expansion ◽  
Alternative Source ◽  
Ground Heat Exchangers ◽  
Point Of Interest ◽  
Constant Source

With the constant increase in energy demand, using renewable energy has become a priority. Geothermal energy is a widely available, constant source of renewable energy that has shown great potential as an alternative source of energy in achieving global energy sustainability and environment protection. When exploiting geothermal energy, whether is for heating or cooling buildings or generating electricity, a ground heat exchanger (GHE) is the most important component, whose performance can be easily improved by following the latest design aspects. This article focuses on the application of different types of GHEs with attention directed to deep vertical borehole heat exchangers and direct expansion systems, which were not dealt with in detail in recent reviews. The article gives a review of the most recent advances in design aspects of GHE, namely pipe arrangement, materials, and working fluids. The influence of the main design parameters on the performance of horizontal, vertical, and shallow GHEs is discussed together with commonly used performance indicators for the evaluation of GHE. A survey of the available literature shows that thermal performance is mostly a point of interest, while hydraulic and/or economic performance is often not addressed, potentially resulting in non-optimal GHE design.

scholarly journals The potential of Earth-to-Air Heat Exchangers for reducing energy demand in Spanish dwellings

2014 ◽  
pp. 413-418
Author(s):  
E. Massaguer ◽  
J.R. González ◽  
A. Massaguer ◽  
J. Ricart ◽  
S. Lorenz
Keyword(s):  
Heat Exchangers ◽  
Energy Demand ◽  
Reducing Energy

scholarly journals Enhancement of heat exchangers with metal foams

2019 ◽  
Vol 9 (1) ◽  
pp. 15-28
Author(s):  
Mete Ozturk ◽  
Bahadır Dogan
Keyword(s):  
Heat Transfer ◽  
Surface Area ◽  
Heat Exchangers ◽  
Energy Demand ◽  
Emerging Technologies ◽  
Metal Foams ◽  
Heat Transfer Surface ◽  
Technological Equipment ◽  
Surface Areas

Removal of the heat is becoming a vital issue for safer operations of today’s technological equipment. The necessity of heat exchangers is underlined at this stage for the sake of the emerging technologies, which are producing more heat than before by the increment of the higher energy demand during their operations. Several methods have been suggested to improve the efficiency of the heat exchangers in last decades by the researchers including the extension of the heat transfer surface by the larger surface areas surrounding the channels. In addition to this fundamental approach (extension of the surface area), alternate methods have been released too including the implementation of metal foams to the heat exchangers as for the extension of the surface. Keywords: Heat exchangers, surface extension, metal foams.

Efficient Ways of Turning to Account Geothermal Energy for Heating in Energy Efficient Buildings

2017 ◽  
Vol 21 ◽  
pp. 437-444 ◽  
Author(s):  
Raluca Paula Moldovan ◽  
Gheorghe Viorel Dragoș ◽  
Marina Verdeș ◽  
Vasilică Ciocan ◽  
Marius Costel Bălan ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Energy Efficient ◽  
Geothermal Energy ◽  
Energy Demand ◽  
Negative Impact ◽  
Heat Pumps ◽  
Economic Framework ◽  
Energy Efficient Buildings ◽  
Optimum Solution ◽  
Heating Energy Demand

Within the present context of the effects of climate changes upon the environment, social and economic framework, but also of the trend of population growth and urban development, ensuring a sustainable, competitive and secure energy development will be possible, primarily, by reducing the negative impact of buildings upon the environment, improving energetic and ecological performances of systems and buildings envelope and promoting renewable sources of energy. In this sense, the paper analyzes, in dynamic simulation regime, performant solutions to reduce the energy consumption for heating energy efficient buildings and greenhouse gas emissions, by harnessing geothermal energy through the use of heat pumps and earth-to-air heat exchangers. The case study starts from an energy efficient building, analyzing the dynamic thermal behavior of the building and then various configurations of earth-to-air heat exchangers in terms of heating potential. For the selection of the optimum solution in terms of coverage of the heating energy demand, different systems combining heat pumps and earth-to-air heat exchangers are studied.

Experimental Study of a Earth-to-Air Heat Exchanger Coupled to a Photovoltaic System

2004 ◽  
Vol 126 (1) ◽  
pp. 620-625 ◽  
Author(s):  
Athanassios A. Argiriou ◽  
Spyridon P. Lykoudis ◽  
Constantinos A. Balaras ◽  
Demosthenes N. Asimakopoulos
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Energy Demand ◽  
Photovoltaic System ◽  
Summer Period ◽  
Photovoltaic Array ◽  
Innovative System ◽  
Cooling Loads ◽  
System Coupling ◽  
Cooling Energy Demand

Coupling a building to the ground as a heat sink through earth-to-air heat exchangers can reduce the cooling energy demand during summer. The fans for circulating the air through the heat exchangers are usually grid connected. However, given that the cooling loads are almost in phase with the available solar irradiance, an innovative system coupling an earth-to-air heat exchanger with a simple photovoltaic array has been designed. The experimental results are presented and discussed in this paper. The system was installed and studied in Athens, Greece during a summer period. The obtained results showed that the overall thermal performance of the system and the efficiencies involved indicate that earth-to-air heat exchangers are an interesting hybrid cooling technique and another field of application of photovoltaics.

Determination of creep mechanisms in various silicon carbides via TEM

1986 ◽  
Vol 44 ◽  
pp. 484-487
Author(s):  
C. H. Carter ◽  
J. E. Lane ◽  
J. Bentley ◽  
R. F. Davis
Keyword(s):  
Heat Exchangers ◽  
Sintered Material ◽  
Polycrystalline Material ◽  
Chemical Vapor ◽  
Graphite Substrate ◽  
Second Phase ◽  
Reaction Bonding ◽  
Creep Mechanisms ◽  
Porous Sic

Silicon carbide (SiC) is the generic name for a material which is produced and fabricated by a number of processing routes. One of the three SiC materials investigated at NCSU is Norton Company's NC-430, which is produced by reaction-bonding of Si vapor with a porous SiC host which also contains free C. The Si combines with the free C to form additional SiC and a second phase of free Si. Chemical vapor deposition (CVD) of CH3SiCI3 onto a graphite substrate was employed to produce the second SiC investigated. This process yielded a theoretically dense polycrystalline material with highly oriented grains. The third SiC was a pressureless sintered material (SOHIO Hexoloy) which contains B and excess C as sintering additives. These materials are candidates for applications such as components for gas turbine, adiabatic diesel and sterling engines, recouperators and heat exchangers.

A novel ligand with –NH2 and –COOH-decorated Co/Fe-based oxide for an efficient overall water splitting: dual modulation roles of active sites and local electronic structure

2020 ◽  
Vol 10 (18) ◽  
pp. 6266-6273
Author(s):  
Yalan Zhang ◽  
Zebin Yu ◽  
Ronghua Jiang ◽  
Jung Huang ◽  
Yanping Hou ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Water Splitting ◽  
Energy Demand ◽  
Active Sites ◽  
Electrode Materials ◽  
Global Energy ◽  
Overall Water Splitting ◽  
Local Electronic Structure ◽  
Electrochemical Water Splitting

Excellent electrochemical water splitting with remarkable durability can provide a solution to satisfy the increasing global energy demand in which the electrode materials play an important role.

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

Sign in / Sign up

Export Citation Format

Share Document