scholarly journals Techno-Economic Performance Assessment of a Trigeneration System Operating in a Hospital

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5105
Author(s):  
Aikaterini Papadimitriou ◽  
Anastasios Tosios ◽  
Eugenia Giannini
Keyword(s):  
Economic Performance ◽  
Electric Energy ◽  
Performance Standards ◽  
Field Measurements ◽  
Total Efficiency ◽  
Design Standards ◽  
Financial Assessment ◽  
Heating And Cooling ◽  
Real Behavior ◽  
Combined Cooling

The techno-economic performance evaluation of a combined cooling heating and power (CCHP) system installed in a hospital building in Greece is presented. The aim was to verify performance standards and evaluate real behavior, while highlighting the economic gains. In this research, system performance was evaluated using actual and year-round field measurements. The data were used to calculate the recovered heat and the generated electric energy. Furthermore, the performance was modeled and compared to the manufacturer specifications. Financial assessment was conducted through energy cost analysis to verify the operating viability of the system, both for its heating and cooling functions. The results showed that, overall, after eight years of operation, the energy efficiency was still within design standards. Electrical efficiency was constantly above 30%, while thermal efficiency was around 40–45%. Total efficiency was usually above the 75% threshold, characterizing the system as fully CHP operating. The analysis also pointed out the economic effectiveness of the system in the Greek energy market. The results verified the potential of a CCHP system for improving the energy and economic performance of a building.

Micro-Thermoelectric-Generator Design and Analysis Based on Catalytic Combustion of Hydrogen

2011 ◽  
Vol 216 ◽  
pp. 713-717
Author(s):  
Feng Wang ◽  
Guo Qiang Wang ◽  
Jing Zhou ◽  
Xin Jing Zhou
Keyword(s):  
Temperature Difference ◽  
Catalytic Combustion ◽  
Thermoelectric Generator ◽  
Reaction Rate ◽  
Total Efficiency ◽  
Design And Optimization ◽  
Heating And Cooling ◽  
Micro Thermoelectric Generator ◽  
Generator Design ◽  
Combustion Of Hydrogen

The micro-thermoelectric-generator based on combustion of hydrogen and oxygen was designed. With the application of general finite reaction rate model in CFD software of FLUENT, the effect of inlet parameters on the highest temperature difference between the hot and cold plate of the generator was studied. Results show that, the temperature in the heating and cooling channel of the micro-thermoelectric-generator is uniform; With the increasing of inlet reactant temperature, the highest temperature difference increases, but the total efficiency of the generator decreases. Results can be used to the further design and optimization of micro-thermoelectric-generator based on hydrogen catalytic combustion.

scholarly journals Defying the Footprint Oracle: Implications of Country Resource Trends

2019 ◽  
Vol 11 (7) ◽  
pp. 2164 ◽  
Author(s):  
Mathis Wackernagel ◽  
David Lin ◽  
Mikel Evans ◽  
Laurel Hanscom ◽  
Peter Raven
Keyword(s):  
International Development ◽  
Low Income ◽  
Economic Performance ◽  
Analysis Data ◽  
Low Income Countries ◽  
Data Sets ◽  
Economic Policies ◽  
Economic Implications ◽  
Financial Assessment ◽  
Resource Dynamics

Mainstream competitiveness and international development analyses pay little attention to the significance of a country’s resource security for its economic performance. This paper challenges this neglect, examining the economic implications of countries resource dynamics, particularly for low-income countries. It explores typologies of resource patterns in the context of those countries’ economic prospects. To begin, the paper explains why it uses Ecological Footprint and biocapacity accounting for its analysis. Data used for the analysis stem from Global Footprint Network’s 2018 edition of its National Footprint and Biocapacity Accounts. Ranging from 1961 to 2014, these accounts are computed from UN data sets. The accounts track, year by year, how much biologically productive space is occupied by people’s consumption and compare this with how much productive space is available. Both demand and availability are expressed in productivity-adjusted hectares, called global hectares. Using this biophysical accounting perspective, the paper predicts countries’ future socio-economic performance. This analysis is then contrasted with a financial assessment of those countries. The juxtaposition reveals a paradox: Financial assessments seem to contradict assessments based on biophysical trends. The paper offers a way to reconcile this paradox, which also elevates the significance of biophysical country assessments for shaping successful economic policies.

Performance Standards vs. Design Standards: Facilitating a Shift toward Best Practices

2019 ◽  
Author(s):  
Laura Montgomery ◽  
Patrick A. McLaughlin ◽  
Tyler Richards ◽  
Mark Febrizio
Keyword(s):  
Best Practices ◽  
Performance Standards ◽  
Design Standards

scholarly journals Voltage Unbalance, Power Factor and Losses Optimization in Electrified Railways Using an Electronic Balancer

Electricity ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 554-572
Author(s):  
António P. Martins ◽  
Pedro Rodrigues ◽  
Mahmoud Hassan ◽  
Vítor A. Morais
Keyword(s):  
Low Power ◽  
Power Factor ◽  
Electric Energy ◽  
Field Measurements ◽  
Electric Grid ◽  
Voltage Unbalance ◽  
Three Phase ◽  
Railway System ◽  
Regenerative Energy ◽  
Electrified Railways

Unbalanced currents, low power factor and high losses contribute to increasing the bill infrastructure managers must pay to the TSO/DSO operator that supplies electric energy to the railway system. Additionally, if regenerative energy coming from braking regimes is not allowed to be injected into the grid or even is penalized when it occurs, then the optimization of those parameters must be pursued. One of the possible measures that can be taken to counteract those phenomena is the installation of electronic balancers in heavy loaded substations in order to optimize the interface to the three-phase electric grid. This paper shows the benefit of such use taking examples from real conditions and realistic simulations assumed equivalent to field measurements.

Energy and Exergy Investigations Upon Tri-Generation Based Combined Cooling, Heating, and Power (CCHP) System for Community Applications

2017 ◽  
Author(s):  
Meeta Sharma ◽  
Onkar Singh
Keyword(s):  
Gas Turbine ◽  
Second Law Of Thermodynamics ◽  
Plant Size ◽  
Heating And Cooling ◽  
Energy And Exergy ◽  
Increasing Demand ◽  
The Cost ◽  
Alternate Fuels ◽  
Combined Cooling ◽  
Gas Turbine Cycle

The continually increasing demand for electricity, cooling and heating accompanied by depleting energy sources, makes it inevitable to use the technologies to harness the available resources to their maximum capacity. The tri-generation systems are the advanced and popular technological option for efficient, reliable, flexible, and less polluting alternatives to utilize the conventional energy resources in an optimal way. In this work, the energy available with conventional fuel is utilized along with solar energy collected through parabolic trough collectors which are integrated with steam injected gas turbine cycle for combined power, heating and cooling requirements. Here a thermodynamic model has been developed for the considered tri-generation combined cooling, heating, and power (CCHP) system and the detailed energy and exergy analysis is performed. The results obtained, by the thermodynamic modeling and analyses of CCHP system based on the first and second law of thermodynamics have been presented and conclusions are drawn from their analysis. This work provides the energy efficient solution for combined heating, cooling, and power for medium load in community usage which may require plant size in the range of 10–50 MW. However, the cost effectiveness depends on the relative cost of gas turbine fuel with respect to other alternate systems with alternate fuels.

scholarly journals Evolutionary Maximization of Energy Amount Harvested by Means of Panel of Thermoelectric Modules

2022 ◽  
Vol 12 (2) ◽  
pp. 539
Author(s):  
Tomasz Golonek
Keyword(s):  
High Speed ◽  
Electric Energy ◽  
Load Level ◽  
Total Efficiency ◽  
Evolutionary Computations ◽  
Thermoelectric Modules ◽  
Concurrent Optimization ◽  
Peltier Modules ◽  
System Temperature ◽  
Global Mppt

This work proposes the use of a specialized algorithm based on evolutionary computation to the global MPPT regulation of panel of thermoelectric modules connected serially in numerous string sections. Each section of the thermovoltaic panel is equipped with local DC/DC converter controlled by the proposed algorithm and finally this allows the optimization of the total efficiency of conversion. Evolutionary computations adjust PWM signals of switching waveforms of DC/DC sectional simple boost converters, which have outputs configured in parallel. It gives the chance to obtain the highest level of electric energy harvested, i.e., thanks to boost converting operational points precise adaptation to the system temperature profile as well as electric load level. The simulation results of the proposed evolutionary technique confirmed the high speed of the MPPT process that is much better than for perturbation and observation, as well as incremental conductance methods, and it assures concurrent optimization of numerous PWM signals. Next, the work shows practical optimization results achieved by the proposed algorithm implemented to microcontroller module controlling the DC/DC converter during thermal to electric conversion experiment. A laboratory thermovoltaic panel was constructed from a string of Peltier modules and radiator that assured passive cooling. The measurements obtained once more proved the MPPT evolutionary regulation properness and its adaptation effectiveness for different resistive test loads.

The Sewage Treatment and Disposal Problem in Cyprus in the Absence of Sewerage Systems: Limassol Case Study – Evaluation of Compromise Solutions

1989 ◽  
Vol 21 (1) ◽  
pp. 77-86
Author(s):  
E. Malikides
Keyword(s):  
High Efficiency ◽  
Sewage Treatment ◽  
Performance Standards ◽  
Design Standards ◽  
Treatment Methods ◽  
Decentralized System ◽  
Bathing Waters ◽  
Residential Units ◽  
Construction Operation ◽  
Treatment And Disposal

Due to lack of central sewerage systems in coastal towns of Cyprus, temporary measures have been imposed to protect health and environment. As a result sewage is treated in small biological plants serving individual residential units. Effectiveness of treatment methods employed were examined and the method of extended aeration has been proved to be the most suitable for Cyprus conditions. Design standards have to be modified taking into account Cyprus specific conditions, especially that of temperature. Statistical results from 54 small treatment plants operating in the town of Limassol showed that the vast majority of the plants failed to meet either performance standards in terms of BOD5, SS, or bacteriological requirements in terms of faecal coliforms. It was identified that the main reason for this was the lack of proper maintenance. The bacteriological quality of bathing waters has not been affected by temporary measures although many secondary problems have arisen from the operation of about 90 small treatment plants at Limassol town. The per capita cost of construction, operation and maintenance of this decentralized system has been proved extremely high compared with that of centralized system. Improvement of the situation, in the short term, includes reconsideration of temporary measures, modification of design standards relying on reliable and high efficiency treatment methods and rising of plants maintenance level. Radical solution of the problem is the construction of the central sewerage system.

scholarly journals Impacts of Investment Cost, Energy Prices and Carbon Tax on Promoting the Combined Cooling, Heating and Power (CCHP) System of an Amusement Park Resort in Shanghai

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4252
Author(s):  
Liting Zhang ◽  
Weijun Gao ◽  
Yongwen Yang ◽  
Fanyue Qian
Keyword(s):  
Economic Performance ◽  
Carbon Dioxide Emissions ◽  
Carbon Tax ◽  
Energy Prices ◽  
Amusement Park ◽  
Energy Supply System ◽  
Market Competitiveness ◽  
Investment Cost ◽  
Combined Cooling ◽  
Investment Subsidy

Poor economic performance has limited the diffusion of the combined cooling, heating, and power (CCHP) system. Various factors influence the economic performance of the CCHP system. To analyze the impacts of these different factors and promote the CCHP system, this study evaluated its comprehensive performance through a multi-criteria method, using an amusement park resort in Shanghai as a research case. First, three CCHP systems with different penetration rates were presented and simulated in a transient simulation model for comparison. The economic and environmental performance of these different penetration CCHP systems were evaluated based on the dynamic payback period and carbon dioxide emissions. The impacts of investment cost, energy prices, investment subsidy and a carbon tax on the economic performance of the three systems were discussed, and a sensitivity analysis was used to compare these factors. The results show that the current subsidy can reduce the economic gap between the CCHP system and the conventional system, but it still needs to be increased by 1.71 times to achieve market competitiveness of the CCHP system with 100% penetration under the current investment cost and energy prices. In addition, the introduction of a carbon tax could accelerate the promotion of the CCHP system. When the carbon tax reaches 25 $/ton, the CCHP system becomes the best choice of energy supply system.

scholarly journals Economic Assessment of Cogeneration Systems in Operation

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2206 ◽  
Author(s):  
Aikaterini Papadimitriou ◽  
Vassilios Vassiliou ◽  
Kalliopi Tataraki ◽  
Eugenia Giannini ◽  
Zacharias Maroulis
Keyword(s):  
Economic Performance ◽  
Performance Indicators ◽  
Operating Performance ◽  
Economic Assessment ◽  
Combined Heat And Power ◽  
Current Situation ◽  
Systematic Method ◽  
Break Even Point ◽  
Combined Cooling

A systematic method to evaluate the economic operating performance of existing combined heat and power (CHP) or combined cooling heat and power (CCHP) generation systems is applied. Two key performance indicators are selected to evaluate both the technical and the economic performance, based on operating recording data; the capacity factor and the capital recovery. The case study for eight projects in Athens is presented with the purpose to reveal the current situation of CHP in Greece and identify reasons that are hindering its penetration. Interesting conclusions were reached from the analysis. Only two out of the eight projects managed to achieve the break-even point in less than four years since the beginning of their operation, while oversizing phenomena were noticed in many cases leading in extremely low capacity factors.

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