scholarly journals Energy Performance Optimization in a Condensing Boiler

2021 ◽  
Vol 9 (1) ◽  
pp. 6
Author(s):  
Diego Fernández-Cheliz ◽  
Eloy Velasco-Gómez ◽  
Juan Peral-Andrés ◽  
Ana Tejero-González
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Performance Optimization ◽  
Energy Performance ◽  
Primary Energy ◽  
Operating Conditions ◽  
Hot Water ◽  
Operating Parameters ◽  
Climate Conditions ◽  
Lower Heating Value

In Europe, primary energy consumption in buildings accounts for up to 25–40%, depending on the climate conditions. Space heating and Domestic Hot Water (DHW) contribute significantly to this energy consumption. Among the most common sources for heat generation in these appliances is natural gas. Condensing boilers can surpass the 100% energy performance over the lower heating value, if the operating conditions enable the water vapor in the exhaust gases to condensate. Consequently, optimizing the operating parameters of condensing boilers is necessary to decrease fuel consumption without hindering water heating needs. The present work presents an experimental approach to the operating parameters of a condensing boiler that works with natural gas. The aim is to develop a theoretical model that relates the energy performance to the water temperature set by the final user and the excess air set by the maintenance staff.

scholarly journals Real Domestic Hot Water Consumption in Residential Buildings and Its Impact on Buildings’ Energy Performance—Case Study in Poland

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5010
Author(s):  
Katarzyna Ratajczak ◽  
Katarzyna Michalak ◽  
Michał Narojczyk ◽  
Łukasz Amanowicz
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Water Consumption ◽  
Residential Buildings ◽  
Energy Performance ◽  
Primary Energy ◽  
Hot Water ◽  
Domestic Hot Water ◽  
Total Energy Balance ◽  
Consumption Rates

A building’s energy consumption is assessed considering the energy required for heating, cooling, lighting, and domestic hot water (DHW). Methodologies used to calculate energy certificates in European Union countries consider hot water consumption rates per person or per heated (floor) area, giving wide-ranging values (35–88 dm3/person/day). Using extreme parameters, it is possible to obtain a primary energy index that meets the legal requirements, although unrealistically large proportions of domestic hot water use relative to the total energy balance of the building may marginalize the influence of other components, such as fluctuations in heating, ventilation, or lighting. In the current work, the DHW consumption of three residential buildings was measured to verify the energy consumption for hot water preparation. Investigations were conducted based on the consumption of natural gas for DHW preparation. Experimentally obtained water consumption rates were determined per m2 of a dwelling and per person living in the building. The calculated indicators (0.85 ± 0.005 dm3/m2/day and 27.4 ± 1.4 dm3/person/day) were lower than those used for energy certifications of buildings. The experimentally obtained indicators were used in further theoretical energy assessments of six residential buildings. By adopting the designated indicators, the analyzed buildings met the legally required primary energy value (<70 kWh/m2/year) when using natural gas as a heat source. Applying more realistic DHW consumption values resulted in more accurate energy certifications.

scholarly journals Adsorption gas Heat Pump fuelled with hydrogen enriched natural gas blends: the analytical simulation model development and validation

2020 ◽  
Vol 197 ◽  
pp. 08002
Author(s):  
Matteo Sforzini ◽  
Gianluigi Lo Basso ◽  
Romano Paiolo ◽  
Livio De Santoli ◽  
Fabrizio Cumo
Keyword(s):  
Natural Gas ◽  
Simulation Model ◽  
Heat Pump ◽  
Energy Performance ◽  
Operating Conditions ◽  
Hot Water ◽  
Relative Standard Error ◽  
Outlet Temperature ◽  
Experimental Campaign ◽  
Relative Standard

This study deals with the implementation of an analytical model to simulate the energy performance associated to a commercial Gas adsorption Heat Pump, when H2NG (Hydrogen Enriched Natural Gas) blends are used as fuel. In detail, a water source heat pump manufactured by Robur (GAHP-WS) has been used as a reference device for building the simulation model within the MATLAB-Simulink environment. Thereafter, the simulation results have been validated by the experimental campaign, testing on field and in actual operating conditions the heat pump. Specifically, the model has been developed by implementing the WaterAmmonia mass and energy balances for each component. It is able to evaluate fuel consumption, efficiency in terms of GUE, required thermal power from the cold heat sink as well as the water outlet temperature at the evaporator, once the heating load is used as the main input. The experimental campaign for the model calibration and validation has been carried out over the winter season. Additionally, the heat pump performance has been detected when it operates to supply hot water at 60 °C and 55 °C, and it is fuelled with growing hydrogen fractions, starting from 0% vol., 5% vol. up to 10% vol. In the end, the standard errors as well as the relative ones affecting the main output parameters have computed for the validation process. From the outcomes it emerges that the average relative standard error related to all load conditions is lower than 2.5% for natural gas operation. On the contrary, it ranges between 2.5% and 4% when H2NG at 5% and 10% by volume have been burnt.

scholarly journals Experimental Assessment of Energy Performance and Emissions of a Residential Microcogenerator

2014 ◽  
Vol 1 (2) ◽  
pp. 48 ◽  
Author(s):  
Giovanni Angrisani ◽  
Carlo Roselli ◽  
Maurizio Sasso ◽  
Peter Tzscheutschler
Keyword(s):  
Energy Saving ◽  
High Efficiency ◽  
Thermal Power ◽  
Experimental Tests ◽  
Energy Performance ◽  
Primary Energy ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Hot Water ◽  
Test Facility

Microcogeneration can guarantee sensible primary energy savings and greenhouse gas emissions reductions in the residential sector. In this paper, the results of experimental tests carried out on a microcogenerator (5.5 kW electric power and 14.8 kW thermal power) based on a natural gas fuelled internal combustion engine, integrated with a condensing boiler, have been analyzed. Tests have been performed out at Institute for Energy Economy and Application Technology (IfE) of Technical University of Munich (Germany). The test facility allowed to simulate the thermal energy requirements of a real residential application, represented by a Multi Family House consisting of 10 apartments, and to evaluate the energy flows of the conversion devices in actual operating conditions. Four type days, characteristic of Mediterranean climatic conditions, have been used to define space heating and domestic hot water user’s requirements. Experimental tests have been performed to implement energy and environmental analysis, comparing the system consisting of cogenerator and integration boiler with a reference system. Results showed that the former can achieve a primary energy saving of about 6%, and CO2 equivalent emissions reduction of about 12%. Finally, the algorithm defined by the European Directive on the promotion of high efficiency cogeneration has been implemented; it demonstrated that the primary energy saving is well above the limit value prescribed by the Directive. Therefore the cogeneration plant can access support mechanisms that can help to achieve the economic feasibility of the system, besides energy and environmental benefits.

Effect of the Power Generation Unit Size on the Energy Performance of Cooling, Heating, and Power Systems

2008 ◽  
Author(s):  
N. Fumo ◽  
P. J. Mago ◽  
L. M. Chamra
Keyword(s):  
Power Generation ◽  
Energy Consumption ◽  
Building Energy ◽  
Energy Performance ◽  
Primary Energy ◽  
Energy Strategy ◽  
Climate Conditions ◽  
Power Generation Unit ◽  
Chp System ◽  
Generation Unit

Cooling, Heating, and Power (CHP) systems are a form of distributed generation that can provide electricity while recovering waste heat to be used for space and water heating, and for space cooling by means of an absorption chiller. CHP systems improve the overall thermal energy efficiency of a building, while reducing energy consumption. Since energy conservation has implications on energy resources and environment, CHP systems energy performance should be evaluated based on building primary energy consumption. Primary energy consumption includes the energy consumed at the building itself (site energy) plus the energy used to generate, transmit, and distribute the site energy. The objective of this investigation is to determine the effect of the power generation unit (PGU) size on the energy performance of CHP systems. Since CHP systems energy performance varies with the building energy profiles, in this study the same building is evaluated for three different cities with different climate conditions. This paper includes simulation results for the cases when a CHP system operates with and without a primary energy strategy. Results show that for any PGU size energy savings are guaranteed only when the primary energy strategy is applied. Since CHP system energy performance depends on the building energy use profiles, which depend on climate conditions and other factors such as building characteristic and operation, each case requires a particular analysis in order to define the optimum size of the power generation unit.

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 Case Study of Thermal Diagnostics of Single-Family House in Temperate Climate

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4549 ◽  
Author(s):  
Aleksandra Specjał ◽  
Aleksandra Lipczyńska ◽  
Maria Hurnik ◽  
Małgorzata Król ◽  
Agnieszka Palmowska ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Ventilation System ◽  
Energy Performance ◽  
Primary Energy ◽  
Building Envelope ◽  
Hot Water ◽  
Temperate Climate ◽  
Normative Values ◽  
Single Family ◽  
Family House

Reduction of the primary energy consumption is a crucial challenge for the building sector due to economic and environmental issues. Substantial savings could be achieved within the household. In this paper, we investigate the energy performance of a single-family house located in the temperate climate. The assessment is based on the comprehensive thermal diagnostic of the building performed on-site and via computational analyses. The on-site measurements included diagnostics of the building envelope, heat source, heating and domestic hot water system, ventilation system, and indoor environmental quality. Analyses confirmed that the studied building, which was built in 2008, meets the legislation requirements for the primary energy usage at that time and nowadays. However, results show discrepancies between energy performance obtained through on-site measurements and computational methods following regulations. Partially, discrepancies are a result of differences on normative values and how the building is operated in practice. It is also showed how important the role in the assessment of energy consumption through measurements is played by the measurement period.

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.

Performance analysis of a combined cooling, heating, and power system driven by a waste biomass fired Stirling engine

2010 ◽  
Vol 225 (2) ◽  
pp. 420-428 ◽  
Author(s):  
J Harrod ◽  
P J Mago
Keyword(s):  
Energy Consumption ◽  
Natural Gas ◽  
Wood Chip ◽  
Primary Energy ◽  
Stirling Engine ◽  
Primary Energy Consumption ◽  
Operational Cost ◽  
Excess Production ◽  
Prime Movers ◽  
Combined Cooling

Due to the soaring costs and demand of energy in recent years, combined cooling, heating, and power (CCHP) systems have arisen as an alternative to conventional power generation based on their potential to provide reductions in cost, primary energy consumption, and emissions. However, the application of these systems is commonly limited to internal combustion engine prime movers that use natural gas as the primary fuel source. Investigation of more efficient prime movers and renewable fuel applications is an integral part of improving CCHP technology. Therefore, the objective of this study is to analyse the performance of a CCHP system driven by a biomass fired Stirling engine. The study is carried out by considering an hour-by-hour CCHP simulation for a small office building located in Atlanta, Georgia. The hourly thermal and electrical demands for the building were obtained using the EnergyPlus software. Results for burning waste wood chip biomass are compared to results obtained burning natural gas to illustrate the effects of fuel choice and prime mover power output on the overall CCHP system performance. Based on the specified utility rates and including excess production buyback, the results suggest that fuel prices of less than $23/MWh must be maintained for savings in cost compared to the conventional case. In addition, the performance of the CCHP system using the Stirling engine is compared with the conventional system performance. This comparison is based on operational cost and primary energy consumption. When electricity can be sold back to the grid, results indicate that a wood chip fired system yields a potential cost savings of up to 50 per cent and a 20 per cent increase in primary energy consumption as compared with the conventional system. On the other hand, a natural gas fired system is shown to be ineffective for cost and primary energy consumption savings with increases of up to 85 per cent and 24 per cent compared to the conventional case, respectively. The variations in the operational cost and primary energy consumption are also shown to be sensitive to the electricity excess production and buyback rate.

A Small Gas Turbine Plant for Cogeneration of Electricity, Thermal and Cooling Thermal Energy With an Absorption Unit

1997 ◽  
Author(s):  
Maurizio De Lucia ◽  
Carlo Lanfranchi ◽  
Antonio Matucci
Keyword(s):  
Gas Turbine ◽  
Thermal Energy ◽  
Operating Conditions ◽  
Hot Water ◽  
Plant Performance ◽  
Cooling Power ◽  
Operating Parameters ◽  
The European Union ◽  
Cogeneration Plant ◽  
Two Stage

A cogeneration plant with a small gas turbine was installed in a pharmaceutical factory and instrumented for acquiring all the values necessary to appraise both its energetic and cost advantages. The plant was designed and built as a demonstrative project under a program for energy use improvement in industry, partially financed by the European Union. The system comprises as its main components: 1) a gas turbine cogeneration plant for production of power and thermal energy under the form of hot water, superheated water, and steam; 2) a two-stage absorption unit, fueled by the steam produced in the cogeneration plant, for production of cooling thermal energy. The plant was provided with an automatized control system for the acquisition of plant operating parameters. The large amount of data thus provided made it possible to compare the new plant, under actual operating conditions, with the previously existing cooling power station with compression units, and with a traditional power plant. This comparative analysis was based on measurements of the plant operating parameters over nine months, and made it possible to compare actual plant performance with that expected and ISO values. The analysis results reveal that gas turbine performance is greatly affected by part-load as well as ambient temperature conditions. Two-stage absorber performance, moreover, turned out to decrease sharply and more than expected in off-design operating conditions.

Analysis of Energy Sources on Energy Indicators Performance

2016 ◽  
Vol 861 ◽  
pp. 198-205
Author(s):  
Anton Pitonak ◽  
Martin Lopusniak
Keyword(s):  
European Union ◽  
Energy Demand ◽  
Energy Performance ◽  
Primary Energy ◽  
Hot Water ◽  
Energy Class ◽  
The European Union ◽  
Total Consumption ◽  
Minimum Requirements ◽  
Global Indicator

In the members states of the European Union, portion of buildings in the total consumption of energy represents 40%, and their portion in CO2 emissions fluctuates around 35%. The European Union is trying to protect the environment by reducing energy demand and releasing CO2 emissions into the air. Energy performance is the quantity of energy, which is necessary for heating and domestic hot water production, for cooling and ventilation and for lighting. Based on results of energy performance, individual buildings are classified into energy classes A to G. A global indicator (primary energy) is the decisive factor for final evaluation of the building. The new building must meet minimum requirements for energy performance, i.e. it must be classified to energy class A1 since 2016, and to energy class A0 since 2020. The paper analyses effect of the use of different resources of heat in a family house designed according to requirements valid since 2020, and its subsequent classification into an energy class.

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