scholarly journals Dynamic Simulation and Thermoeconomic Analysis of a Trigeneration System in a Hospital Application

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3558
Author(s):  
Francesco Calise ◽  
Francesco Liberato Cappiello ◽  
Massimo Dentice d’Accadia ◽  
Luigi Libertini ◽  
Maria Vicidomini
Keyword(s):  
Dynamic Simulation ◽  
Economic Performance ◽  
Net Present Value ◽  
Energy Savings ◽  
Control Strategies ◽  
Cooling Capacity ◽  
Building Envelope ◽  
Simplified Approach ◽  
South Italy ◽  
Heating And Cooling

Hospitals are very attractive for Combined Heat and Power (CHP) applications, due to their high and continuous demand for electric and thermal energy. However, both design and control strategies of CHP systems are usually based on an empiric and very simplified approach, and this may lead to non-optimal solutions. The paper presents a novel approach based on the dynamic simulation of a trigeneration system to be installed in a hospital located in Puglia (South Italy), with around 600 beds, aiming to investigate the energy and economic performance of the system, for a given control strategy (electric-load tracking). The system includes a natural gas fired reciprocating engine (with a rated power of 2.0 MW), a single-stage LiBr-H2O absorption chiller (with a cooling capacity of around 770 kW), auxiliary gas-fired boilers and steam generators, electric chillers, cooling towers, heat exchangers, storage tanks and several additional components (pipes, valves, etc.). Suitable control strategies, including proportional–integral–derivative (PID) and ON/OFF controllers, were implemented to optimize the trigeneration performance. The model includes a detailed simulation of the main components of the system and a specific routine for evaluating the heating and cooling demand of the building, based on a 3-D model of the building envelope. All component models were validated against experimental data provided by the manufacturers. Energy and economic models were also included in the simulation tool, to calculate the thermoeconomic performance of the system. The results show an excellent economic performance of the trigeneration system, with a payback period equal to 1.5 years and a profitability index (ratio of the Net Present Value to the capital cost) equal to 3.88, also due to the significant contribution of the subsidies provided by the current Italian regulation for CHP systems (energy savings certificates).

scholarly journals Dynamic Daylight Metrics for Electricity Savings in Offices: Window Size and Climate Smart Lighting Management

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3143 ◽  
Author(s):  
Ignacio Acosta ◽  
Miguel Ángel Campano ◽  
Samuel Domínguez-Amarillo ◽  
Carmen Muñoz
Keyword(s):  
Energy Efficiency ◽  
Net Present Value ◽  
Energy Savings ◽  
Performance Metrics ◽  
Control Strategies ◽  
Window Size ◽  
Weather Conditions ◽  
Worst Case ◽  
Daylight Performance ◽  
Dynamic Metrics

Daylight performance metrics provide a promising approach for the design and optimization of lighting strategies in buildings and their management. Smart controls for electric lighting can reduce power consumption and promote visual comfort using different control strategies, based on affordable technologies and low building impact. The aim of this research is to assess the energy efficiency of these smart controls by means of dynamic daylight performance metrics, to determine suitable solutions based on the geometry of the architecture and the weather conditions. The analysis considers different room dimensions, with variable window size and two mean surface reflectance values. DaySim 3.1 lighting software provides the simulations for the study, determining the necessary quantification of dynamic metrics to evaluate the usefulness of the proposed smart controls and their impact on energy efficiency. The validation of dynamic metrics is carried out by monitoring a mesh of illuminance-meters in test cells throughout one year. The results showed that, for most rooms more than 3.00 m deep, smart controls achieve worthwhile energy savings and a low payback period, regardless of weather conditions and for worst-case situations. It is also concluded that dimming systems provide a higher net present value and allow the use of smaller window size than other control solutions.

scholarly journals Comparative analysis of selected glass systems by dynamic simulation using measured real environmental conditions

2020 ◽  
Vol 172 ◽  
pp. 19009
Author(s):  
Silvia Bizoňová ◽  
Dušan Katunský ◽  
Miloslav Bagoňa
Keyword(s):  
Dynamic Simulation ◽  
Energy Savings ◽  
Building Envelope ◽  
Heat Losses ◽  
Experimental Glass ◽  
Existing Structures ◽  
Spectrally Selective ◽  
The Subject ◽  
Simulation Results ◽  
Made In

The subject of the study presents the measurement of temperatures on surfaces of glass systems of existing structures and the surfaces of experimental glass systems obtained by dynamic simulation. Measurements were made in the test cells of the Faculty of Civil Engineering of the Technical University of Košice. The partial results of which are the basis for the comparison of the currently installed and experimentally designed glass systems using spectrally selective films. The proposed mathematical-physical model was simplified by replacing the sash, frame and its components with a homogenous element with minimal shape modifications, while this does not have a significant effect on the simulation results. The choice of the proposed glass system respects the need for reduction of solar gains in summer and heat losses in buildings in winter through the weakest part of the building envelope and indicates future energy savings in relation to cooling and heating costs with a view to optimizing light and thermal comfort.

scholarly journals Energy, Environmental, and Economic Analyses of Geothermal Polygeneration System Using Dynamic Simulations

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4603
Author(s):  
Francesca Ceglia ◽  
Adriano Macaluso ◽  
Elisa Marrasso ◽  
Carlo Roselli ◽  
Laura Vanoli
Keyword(s):  
Dynamic Simulation ◽  
Net Present Value ◽  
District Heating ◽  
Simulation Models ◽  
Hot Water ◽  
Transfer Coefficients ◽  
Dynamic Simulations ◽  
Data Matching ◽  
Heating And Cooling ◽  
Polygeneration System

This paper presents a thermodynamic, economic, and environmental analysis of a renewable polygeneration system connected to a district heating and cooling network. The system, fed by geothermal energy, provides thermal energy for heating and cooling, and domestic hot water for a residential district located in the metropolitan city of Naples (South of Italy). The produced electricity is partly used for auxiliaries of the thermal district and partly sold to the power grid. A calibration control strategy was implemented by considering manufacturer data matching the appropriate operating temperature levels in each component. The cooling and thermal demands of the connected users were calculated using suitable building dynamic simulation models. An energy network dedicated to heating and cooling loads was designed and simulated by considering the variable ground temperature throughout the year, as well as the accurate heat transfer coefficients and pressure losses of the network pipes. The results were based on a 1-year dynamic simulation and were analyzed on a daily, monthly, and yearly basis. The performance was evaluated by means of the main economic and environmental aspects. Two parametric analyses were performed by varying geothermal well depth, to consider the uncertainty in the geofluid temperature as a function of the depth, and by varying the time of operation of the district heating and cooling network. Additionally, the economic analysis was performed by considering two different scenarios with and without feed-in tariffs. Based on the assumptions made, the system is economically feasible only if feed-in tariffs are considered: the minimum Simple Pay Back period is 7.00 years, corresponding to a Discounted Pay Back period of 8.84 years, and the maximum Net Present Value is 6.11 M€, corresponding to a Profit Index of 77.9% and a maximum Internal Rate of Return of 13.0%. The system allows avoiding exploitation of 27.2 GWh of primary energy yearly, corresponding to 5.49∙103 tons of CO2 avoided emissions. The increase of the time of the operation increases the economic profitability.

Heating and Cooling Performance of Building Integrated Solar Roof Panels

2010 ◽  
Vol 168-170 ◽  
pp. 1735-1741
Author(s):  
Mao Yan ◽  
Li Zhu ◽  
Yi Ping Wang ◽  
Ming Ze Zhu
Keyword(s):  
Energy Consumption ◽  
Cooling Capacity ◽  
Building Envelope ◽  
Total Energy Consumption ◽  
Climate Conditions ◽  
Average Heat ◽  
Operation Conditions ◽  
Heating And Cooling ◽  
Roof Panel ◽  
Collecting Efficiency

With the high proportion of building energy consumption in the total energy consumption, it is of great importance to relieve the shortage of conventional energy resources and improve the building environment by incorporating solar energy into buildings. A new type solar roof panels were designed and tested in the present paper, which perfectly achieves the integration of solar equipment with building envelope. This panel can act as the construction component for building envelope and completely removes the double-skin mode for conventional solar equipment, as well as the functional equipment for heating and cooling collecting. Corrugated colored steel roof panel was tested under various climate conditions and operation conditions. The results show that in a typical sunny day the average heat collecting efficiency is 49% and the average cooling capacity is 100W/m2. In a cloudy day, the average heat collecting efficiency is 41% and the average cooling capacity is 84W/m2.

scholarly journals Energy Renovation of Buildings the Skin of a Building 70’s Housing Developments in Barcelona Montbau’s Housing Developments Renovation

2017 ◽  
Vol 11 (1) ◽  
pp. 27-64
Author(s):  
Josep M. Rieradevall i Pons ◽  
Jaume Avellaneda i Diaz Grande ◽  
Jaume Roset i Calzada
Keyword(s):  
Internal Energy ◽  
Energy Demand ◽  
Energy Savings ◽  
Weather Conditions ◽  
Building Envelope ◽  
Economic Costs ◽  
Building Projects ◽  
Housing Developments ◽  
Heating And Cooling ◽  
Different Characteristics

This study, considering the current conditions of our planet, proposes to analyze how efficient is to renovate building skins to meet energy, economic, and CO2 emission criteria. A building envelope is the part of a building that is most exposed to weather conditions and therefore it has an impact on the internal energy demand of its inhabitants so that they can comfortably there. Studying building skins and their status in terms of energy, economic costs, and CO2 emissions will allow renovation to produce benefits in the medium and long-term. This study was conducted in the neighborhood of Montbau, a housing development of around 30 buildings, each with different characteristics, built in the 70’s and currently having energy losses through their skins, which results in a high demand of internal energy for heating and cooling purposes, in addition to doubled emission of CO2e released into the atmosphere. Improvements are proposed to adapt the conditions of these buildings. Two solutions are proposed in addition to evaluating energy costs caused by CO2e emissions and any other economic costs year 2012. Other studies analyze the behavior of buildings already implementing such solutions and their corresponding energy, emission, and economic reductions. The importance of such studies lays on the need to analyze options such as renovation instead of considering demolition as an alternative, and to suggest the future building of housing developments in pro of the sustainability of our planet and offer an alternative for a sustainable future, housing and shelter under optimal conditions. The figures herein offer solid results in terms of expenses, costs and energy savings, as well as the reduction of CO2 emissions released into the atmosphere. The graphs and tables here contained offer a clear reading and suggest topics for further research and even for starting up building projects, both locally and worldwide.

Optimal Control Strategies for Switchable Roof Insulation Systems Applied to US Residential Buildings

2020 ◽  
Vol 1 (4) ◽  
Author(s):  
Ammar H. A. Dehwah ◽  
Moncef Krarti
Keyword(s):  
Energy Use ◽  
Energy Savings ◽  
Control Strategies ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Envelope ◽  
Optimization Techniques ◽  
Optimal Controls ◽  
Insulation Systems ◽  
Rule Sets

Abstract Switchable building envelope systems, including passive and active systems, have recently seen an increase interest in the literature. Unlike static insulation, switchable insulation systems (SISs) have the ability to adjust the thermal properties of envelope elements. Advanced control strategies for SISs are evaluated in this analysis using genetic algorithm-based optimization techniques. In particular, this study investigates the potential heating and cooling energy savings for deploying optimal controls specific to SIS technologies when applied to residential roofs located in representative US climates. Moreover, energy use and peak demand savings obtained by optimal controls are compared with those obtained from the 2-step rule-based controls. Overall, the analysis results indicate that the maximum monthly additional savings obtained by optimal controls can reach up to 32% compared with 2-step rule sets when an annual analysis is conducted for a residential building located in Golden, CO.

scholarly journals The integrated design of building services by an equipped and eco-efficient module (MOTE2)

2016 ◽  
Vol 1 (2) ◽  
pp. 13 ◽  
Author(s):  
Roberto Giordano ◽  
Cristina Allione ◽  
Andrè Clos ◽  
Elena Montacchini ◽  
Silvia Tedesco
Keyword(s):  
Energy Savings ◽  
Phase 1 ◽  
Integrated Design ◽  
Building Design ◽  
Building Envelope ◽  
Hot Water ◽  
Design Standards ◽  
Heating And Cooling ◽  
Research Activities ◽  
Building Models

<p>The targets set out by European Directives concerning the energy savings in the construction sector refer both to building envelope and to its services. With regard to building services it is mandatory meeting requirements related to heating, cooling, lighting and ventilation.</p><p>Building services take up a variable space in the buildings that cannot be considered anymore negligible and they would always be fully integrated into buildings.</p><p>Equipped and Eco-efficient Technological Module (MOTE2) is a research project aimed at implementing the integration in a unique services cupboard of some building services: heating and cooling; domestic hot water; mechanical ventilation.</p><p>The project was organized according to four main phases. In phase 1 a set of rules was defined matching requirements related to the energy efficiency to environmental building design standards. During the phase 2 six building models were studied in order to size the corresponding building services according to scenario analysis set down for existing buildings. In phase 3 the project was focused on designing the assembly among services.</p><p>The cupboard design is like a Tetris® game through the planning of the best combination among services shape. Based on the drawings developed a first mock-up was built up and monitored. Finally, in phase 4 the paper deals with the MOTE2’s expected performances.</p><p>Outlook and some conclusions point out the future steps of the research activities.</p>

Improving Sustainability of Housing in Ghana through Energy Efficient Climate Control Strategies

2012 ◽  
Vol 608-609 ◽  
pp. 1698-1704
Author(s):  
Abdul Manan Dauda ◽  
Hui Gao
Keyword(s):  
Natural Ventilation ◽  
Energy Savings ◽  
Control Strategies ◽  
Internal Heat ◽  
Climate Control ◽  
Housing Design ◽  
Artificial Lighting ◽  
Testing Procedures ◽  
Mass Housing ◽  
Design Changes

This paper aims at explaining testing procedures used to evaluate the potential of natural ventilation and daylighting applications to passive design of housing in Ghana. The objectives of research were to reduce energy costs and increase the sustainability of housing. From the results of these experiments actual and potential designs are illustrated and discussed. Mass housing results in multi-storey buildings which require substantial artificial lighting and ventilation. Also, with the increasing usage of glass for windows and doors in Ghana, even the shaded depths of buildings require additional daylight usually resulting in more energy consumption. By supplementing the internal lighting levels with daylight, reducing the internal heat load by shading windows to direct radiation and the utilization of natural ventilation over air conditioning where possible, significant energy savings are could be achieved. The research proposes mass housing design changes such as: delivering daylight above the suspended ceiling into the depths of the building by horizontal light pipes and natural ventilation, utilizing stack effect and wind siphonage, etc.

scholarly journals Towards Sustainable Energy Retrofitting, a Simulation for Potential Energy Use Reduction in Residential Buildings in Palestine

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3876
Author(s):  
Sameh Monna ◽  
Adel Juaidi ◽  
Ramez Abdallah ◽  
Aiman Albatayneh ◽  
Patrick Dutournie ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Use ◽  
Energy Savings ◽  
Residential Buildings ◽  
Residential Building ◽  
Simulation Models ◽  
Water Heating ◽  
Heating And Cooling ◽  
Space Cooling ◽  
Cooling Loads

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.

scholarly journals Harvester Evaluation Using Real-Time Kinematic GNSS and Hiring Service Model

2021 ◽  
Vol 3 (2) ◽  
pp. 363-382
Author(s):  
Md. Kamrul Hasan ◽  
Takashi S. T. Tanaka ◽  
Md. Rostom Ali ◽  
Chayan Kumer Saha ◽  
Md. Monjurul Alam
Keyword(s):  
Developing Countries ◽  
Real Time ◽  
Economic Performance ◽  
Net Present Value ◽  
Satellite System ◽  
Cost Ratio ◽  
Great Opportunity ◽  
Real Time Kinematic ◽  
Combine Harvesters ◽  
Asian Developing Countries

To reduce human drudgery and the risk of labor shortages in the Asian developing countries, the appropriate introduction of agricultural machinery, especially combine harvesters, is an urgent task. Custom hiring services (CHSs) are expected to contribute to making paddy harvesters prevalent in developing countries; however, the economic performance has been rarely quantified. The study was carried out to precisely evaluate the machine performance attributes of medium and large combine harvesters using the real-time kinematic (RTK) global navigation satellite system (GNSS) and to estimate the economic performance of CHSs of paddy harvesters in Japan, as a typical case of Asian countries. The financial profitability was evaluated by four major indicators: net present value, benefit–cost ratio, internal rate of return, and payback period. The financial indicators showed that both types of harvester could be considered financially viable. Thus, the investment in combine harvesters can be highly profitable for CHS business by a local service provider and custom-hire entrepreneur, providing a great opportunity to use a combine harvester without initial investment by general farmers. The findings demonstrated the high feasibility of CHSs of paddy harvesters in Japan, while they highlighted that further study is needed to estimate the feasibility of CHS in the other Asian developing countries.

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