scholarly journals THE DEMAND FOR EXERGY DURING THE LIFE CYCLE OF DWELLING HOUSES/TIPINIŲ DAUGIABUČIŲ PASTATŲ GYVAVIMO CIKLO EKSERGIJOS POREIKIŲ ĮVERTINIMAS

1999 ◽  
Vol 5 (1) ◽  
pp. 53-58
Author(s):  
Vytautas Martinaitis
Keyword(s):  
Material Processing ◽  
Life Cycle ◽  
Energy Consumption ◽  
Primary Energy ◽  
Hot Water ◽  
Primary Energy Consumption ◽  
Construction Process ◽  
Optimal Coordination ◽  
Building Life Cycle ◽  
Storey Building

The heat demand for heating and ventilation of dwelling houses depends on the climate and thermal characteristics of buildings. Energy is consumed not only in the process of maintenance of a building, but also for constructing it. The aim of current research is to assess the needs of a building life cycle (constructing, maintenance, demolition) expressed in energy units. In order to determine the energy demand of the building life cycle, lasting from a few decades to a century, the thermodynamic methodology is used. The chosen method is based on a systematic approach, applying analysis through combination of approaches such as thermodynamics exergic approach and method of an economic life cycle. The exergic method describes the energy of different types not only by its quantity, but also by the quality, ie it evaluates different forms of energy and its sources by the same quality criteria. According to the design data of four main types of blocks of flats, based on splitting the thermodynamic model into special stages and analysing data of the primary energy consumption of material processing, and the stages of it, the comparative primary energy consumption levels are defined for the principal building material production and the construction process. Primary energy consumption for typical block of flats construction material processing (forming construction goals, planning, research, coordination, designing, management of the construction process, labour force costs, service costs, transportation, use of machinery, energy and fuel consumption) is different as regards the design variations and construction work technology. For the concrete panel five-storey building it amounts to 4,42 kWh/m2, for a nine-storey building 4,36 kWh/m2, for a five-storey brick house 6,35 kWh/m2, and 11,59 kWh/m2for a nine-storey building. Regular primary energy consumption needs (maintenance and repairs) for a concrete panel five-storey building are 35,45 kWh/m2, for a nine-storey building 39,77 kWh/m2, for a five-storey brick house 44,83 kWh/m2, and 52,54 kWh/m2 for a nine-storey building. 40 per cent of the consumed energy is used for heating and ventilation, the rest of it is used for hot water preparation, lighting, home appliances and repairs. Two renovations and demolition of a building (manufacture of materials and products for renovation, research, designing, realization of the projects, demolition of the building, regeneration of the territory and the waste, systemating the data, development of a new technology) need within the building life cycle from 5 to 12 kWh/m2 of energy. In the existing blocks of flats almost three fourths of energy are used for microclimate and comfort systems, whereas heating and conditioning require one third of primary energy used within the building life cycle. The main strategy for diminishing the level of primary energy consumption in dwelling houses is aimed at developing of technical, mostly thermodynamic, features of heating systems and considering nominal power of those systems and the heating characteristics of exterior surfaces, the optimal coordination of building life cycle energy demands.

scholarly journals Optimization of a Wood Pellet Boiler System Combined with CO2HPs in a Cold Climate Area in Japan

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5531 ◽  
Author(s):  
Taro Mori ◽  
Yusuke Iwama ◽  
Hirofumi Hayama ◽  
Emad Mushtaha
Keyword(s):  
Energy Consumption ◽  
Water Supply ◽  
Co2 Emissions ◽  
Primary Energy ◽  
Cold Climate ◽  
Hot Water ◽  
Water Volume ◽  
Primary Energy Consumption ◽  
Wood Pellet ◽  
Hot Water Supply

Hot water supply is one of the leading consumers of energy in the building sector in cold climate areas. The use of woody biomass is effective in reducing CO2 emissions in hot-water supply systems. This report deals with a system that combines a wood pellet boiler (PB) and a heat pump system with CO2 (CO2HP) that is used in a facility for disabled people. The following research was conducted. The operation of a hybrid system combining a PB and CO2HPs was investigated. While operating the system, four specific operations were developed as countermeasures to save on costs and reduce system troubles while reducing CO2 emissions. The processes and results are introduced. Numerical simulations were carried out to optimize the operation. The hot water temperature, water volume, and hot water loads were simulated. The influence of the water volume ratio on the cost and primary energy consumption under the requirements for safe system operation was studied. The regional economic ripple effects (REREs) of this system were studied. The wood pellet boiler is not only a measure for reducing primary energy consumption but can also play an important role in a regional economy for sustainable development in countries that import energy resources such as Japan.

Primary energy consumption of the dwelling with solar hot water system and biomass boiler

2014 ◽  
Vol 87 ◽  
pp. 1151-1161 ◽  
Author(s):  
Mihaela Berković-Šubić ◽  
Martina Rauch ◽  
Damir Dović ◽  
Mladen Andrassy
Keyword(s):  
Energy Consumption ◽  
Water System ◽  
Primary Energy ◽  
Hot Water ◽  
Primary Energy Consumption ◽  
Biomass Boiler

scholarly journals FACTORS OF THERMODYNAMICAL APPROACH TO BUILDINGS LIFE CYCLE/PASTATO GYVAVIMO CIKLO TERMODINAMINIO VERTINIMO VEIKSNIAI

1996 ◽  
Vol 2 (7) ◽  
pp. 75-84
Author(s):  
Vytautas Martinaitis
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Power Plants ◽  
Building Materials ◽  
Primary Energy ◽  
Climatic Conditions ◽  
Thermodynamic Evaluation ◽  
Climatic Regions ◽  
Minimum Requirements ◽  
Building Life Cycle

The article suggests that non-industrial buildings in Lithuania consume half the final energy including appr.70% heat produced in electric power plants and boiler-houses. In order to ensure standard heating and ventilation conditions for these buildings in terms of climate parameters of a normal year it would require heat consumption of some 22 TWh. However, the energy is required not only for operation and maintenance of the building (for active microclimatic conditioning systems—AMCS), but also for setting up the building (for passive microclimatic conditioning systems—PMCS). The above input is therefore determined by technological level in the building and building materials industries. Rather exact evaluations show that in the course of several next years already, primary energy consumption used for a building maintenance shall be equal to that used while construction thereof. In terms of a building life cycle, this is a fairly short term. Therefore these buildings in terms of energetic approach make an intensive energy-consumption system. It is hereby suggested to apply an exergic analysis for a life cycle of a building under certain climatic conditions and PMCS and AMCS combinations defined by the local produce technology level. Using solely economical (both direct or derived) criteria for this intention is therefore insufficient, because the reliability of economic forecasts for longer prospect falls below any other forecasts of physical quantities. As an example for this, a globally-ecological evaluation of energetic systems based on thermodynamics is therefore presented, and is characterised by thermo-economic and exergo-economic criteria. Further, the article provides formulas and indices for thermodynamic evaluation of climatic conditions which indicate minimum requirements of exergy for operation of AMCS. Furthermore, MCS operating points and zones characteristic of different climatic regions are provided. Tasks for MCS thermodynamic analysis have been formulated to include the processes of production of building and insulation materials, and construction erection process. These should be considered the first three stages of the above task: indices of present exergic input in production of materials; forecast of potential exergic input in production of materials; thermodynamic optimisation of technological processes and equipment of building materials. It is therefore considered, that the integration of separate exergic loss components of building life cycle into a general optimisation task shall enable establishment of thermodynamically-optimum combination of exergic use in the buildings under concrete climatic conditions. This would launch, apart from economic, social and ecological aspects, an approach for handling strategic issues of construction and energetic interaction.

scholarly journals INSULATION EXPEDIENCE OF THE EXTERNAL ENVELOPES OF THE BUILDING IN TERMS OF 2E CRITERIA / PASTATO IŠORINIŲ ATITVARŲ APŠILTINIMO TIKSLINGUMAS 2E RODIKLIŲ POŽIŪRIU

2014 ◽  
Vol 6 (4) ◽  
pp. 407-413
Author(s):  
Mantas Kijevičius ◽  
Kęstutis Valančius
Keyword(s):  
Life Cycle ◽  
Energy Consumption ◽  
Co2 Emissions ◽  
Life Cycle Analysis ◽  
Residential Building ◽  
Primary Energy ◽  
Payback Period ◽  
Primary Energy Consumption ◽  
Structural Elements ◽  
Life Cycle Stages

The paper analyses the insulation expediency of the external envelopes of the building with reference to 2E (energy – primary energy consumption and environmental – CO2 emissions) criteria and presents an overview of thermal insulation and studies on other structural elements based on life cycle analysis. The object of research is a typical residential building. The article determines different insulation materials of external envelopes, primary energy consumption and CO2 emissions by insulating walls from F to B and from B to A ++ class. Graphical interpretation shows primary energy, CO2 and the payback period of 60 years. Also, the paper considers primary energy and CO2 emissions distributed at various life cycle stages. Straipsnyje nagrinėjamas pastato išorinių atitvarų apšiltinimo tikslingumas 2E (energiniu ­– pirminės energijos sąnaudų ir ekologiniu – CO2 – išmetalų) kriterijų požiūriu. Apžvelgti teoriniai darbai, kuriuose statybinės medžiagos nagrinėjamos pirminės energijos ir poveikio aplinkai vertinimo (PAV) požiūriu. Tyrimo objektu pasirinktas gyvenamosios paskirties pastatas. Nagrinėjamos skirtingos išorinių atitvarų termoizoliacinės medžiagos, nustatomi pirminės energijos kiekiai ir CO2 išmetalai apšiltinant atitvaras nuo F iki B ir nuo B iki A++ pastato energinės klasės. Vertinama pagal gyvavimo ciklo analizės metodiką. Pateikiama grafinė interpretacija, rodanti sutaupytos pirminės energijos ir CO2 kiekius per 60 metų laikotarpį, identifikuojamos energetiškai ir ekologiškai priimtiniausios termoizoliacinės medžiagos pastatams apšiltinti.

scholarly journals Cost-Benefit Analysis of Hybrid Photovoltaic/Thermal Collectors in a Nearly Zero-Energy Building

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1582 ◽  
Author(s):  
Conti ◽  
Schito ◽  
Testi
Keyword(s):  
Energy Consumption ◽  
Energy Demand ◽  
Electrical Energy ◽  
Energy System ◽  
Primary Energy ◽  
Hot Water ◽  
Solar Thermal ◽  
Primary Energy Consumption ◽  
Solar Thermal Energy ◽  
Zero Energy

This paper analyzes the use of hybrid photovoltaic/thermal (PVT) collectors in nearly zero-energy buildings (NZEBs). We present a design methodology based on the dynamic simulation of the whole energy system, which includes the building energy demand, a reversible heat pump as generator, the thermal storage, the power exchange with the grid, and both thermal and electrical energy production by solar collectors. An exhaustive search of the best equipment sizing and design is performed to minimize both the total costs and the non-renewable primary energy consumption over the system lifetime. The results show that photovoltaic/thermal technology reduces the non-renewable primary energy consumption below the nearly zero-energy threshold value, assumed as 15 kWh/(m2·yr), also reducing the total costs with respect to a non-solar solution (up to 8%). As expected, several possible optimal designs exist, with an opposite trend between energy savings and total costs. In all these optimal configurations, we figure out that photovoltaic/thermal technology favors the production of electrical energy with respect to the thermal one, which mainly occurs during the summer to meet the domestic hot water requirements and lower the temperature of the collectors. Finally, we show that, for a given solar area, photovoltaic/thermal technology leads to a higher reduction of the non-renewable primary energy and to a higher production of solar thermal energy with respect to a traditional separate production employing photovoltaic (PV) modules and solar thermal (ST) collectors.

scholarly journals Determination of the Energy Performance of a Solar Low Energy House with Regard to Aspects of Energy Efficiency and Smartness of the House

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3232
Author(s):  
Dorota Chwieduk ◽  
Michał Chwieduk
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Solar Energy ◽  
Residential Buildings ◽  
Energy Performance ◽  
Primary Energy ◽  
Hot Water ◽  
Low Energy ◽  
Primary Energy Consumption

The paper shows how difficult it is to prove technically that a building really is both low energy and smart, and that all aspects of energy efficiency have been treated equally. Regulations connected to the determination of the energy performance of residential buildings take into account only space and hot water heating energy consumption and define the indices of maximal primary energy consumption, but not energy needs based on the architecture of the building. A single family house designed and constructed as a low energy solar house in Warsaw’s suburbs is considered. Availability of solar energy and its influence on the architecture of the house is analyzed. A specific solar passive architectural concept with solar southern and cold northern buffer spaces incorporated into the interior of the house is presented. Parameters of the building’s structure, construction materials, as well as operation parameters of equipment and heating systems based on active use of solar energy, ground energy (via a heat pump) and waste heat from a ventilation system are described. Results of calculations give values of final and primary energy consumption index levels of 11.58 kWh/m2 and 25.77 kWh/m2, respectively. However, the official methodology for determination of energy performance does not allow for presenting how energy efficient and smart the building really is.

scholarly journals An Evaluation of the Structure of Energy Consumption in Educational Buildings in Poland After Thermal Retrofitting

2020 ◽  
Vol 28 (4) ◽  
pp. 29-37
Author(s):  
Anna Życzyńska ◽  
Zbigniew Suchorab ◽  
Grzegorz Dyś ◽  
Jakub Čurpek ◽  
Miroslav Čekon
Keyword(s):  
Energy Consumption ◽  
Total Energy ◽  
Energy Performance ◽  
Primary Energy ◽  
Hot Water ◽  
The Other ◽  
Primary Energy Consumption ◽  
Total Energy Consumption ◽  
Energy Demands ◽  
Educational Buildings

AbstractThe paper presents the structure and indices of the annual energy consumption in educational buildings subject to comprehensive thermal retrofitting. Seven buildings were analyzed; the energy consumption for heating and ventilation, hot water preparation, and built-in lighting was analyzed in each of them and, in the case of one structure, also cooling. The indices of the usable, final, and primary energy consumption were analyzed. The values calculated were compared to the requirements of the energy standards in force in Poland. The percentage shares of the above-mentioned energy demands of each of the buildings investigated are given in the total energy performance. Within the investigation, we evaluated the shares of the particular building services in the total energy consumption and determined that even after the thermal retrofitting, the energy demands for heating together with lighting are still the most significant compared to the other demands.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.

scholarly journals Decarbonization of Residential Building Energy Supply: Impact of Cogeneration System Performance on Energy, Environment, and Economics

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2538
Author(s):  
Praveen K. Cheekatamarla
Keyword(s):  
Carbon Dioxide ◽  
Power Generation ◽  
Energy Consumption ◽  
Carbon Footprint ◽  
Residential Buildings ◽  
Building Energy ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Cogeneration System ◽  
The Impact

Electrical and thermal loads of residential buildings present a unique opportunity for onsite power generation, and concomitant thermal energy generation, storage, and utilization, to decrease primary energy consumption and carbon dioxide intensity. This approach also improves resiliency and ability to address peak load burden effectively. Demand response programs and grid-interactive buildings are also essential to meet the energy needs of the 21st century while addressing climate impact. Given the significance of the scale of building energy consumption, this study investigates how cogeneration systems influence the primary energy consumption and carbon footprint in residential buildings. The impact of onsite power generation capacity, its electrical and thermal efficiency, and its cost, on total primary energy consumption, equivalent carbon dioxide emissions, operating expenditure, and, most importantly, thermal and electrical energy balance, is presented. The conditions at which a cogeneration approach loses its advantage as an energy efficient residential resource are identified as a function of electrical grid’s carbon footprint and primary energy efficiency. Compared to a heat pump heating system with a coefficient of performance (COP) of three, a 0.5 kW cogeneration system with 40% electrical efficiency is shown to lose its environmental benefit if the electrical grid’s carbon dioxide intensity falls below 0.4 kg CO2 per kWh electricity.

scholarly journals Assessment Methodology for Efficiency, CO2-Emissions and Primary Energy Consumption for Refrigeration Technologies in the Industry

2018 ◽  
Vol 882 ◽  
pp. 215-220
Author(s):  
Matthias Koppmann ◽  
Raphael Lechner ◽  
Tom Goßner ◽  
Markus Brautsch
Keyword(s):  
Energy Consumption ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Primary Energy ◽  
Primary Energy Consumption ◽  
Assessment Methodology ◽  
Alternative Technologies ◽  
Overall Efficiency ◽  
Chp System ◽  
The Individual

Process cooling and air conditioning are becoming increasingly important in the industry. Refrigeration is still mostly accomplished with compression chillers, although alternative technologies are available on the market that can be more efficient for specific applications. Within the scope of the project “EffiCool” a technology toolbox is currently being developed, which is intended to assist industrials users in selecting energy efficient and eco-friendly cooling solutions. In order to assess different refrigeration options a consistent methodology was developed. The refrigeration technologies are assessed regarding their efficiency, CO2-emissions and primary energy consumption. For CCHP systems an exergetic allocation method was implemented. Two scenarios with A) a compression chiller and B) an absorption chiller coupled to a natural gas CHP system were calculated exemplarily, showing a greater overall efficiency for the CCHP system, although the individual COP of the chiller is considerably lower.

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