The design of Chp plants

International Nuclear Information System (INIS)

Tomassetti, G.

2001-01-01

Chp is considered with a bottom-up view, as the most efficient way to satisfy the needs of the users. In order to achieve optimal results a particular care must be used in analyzing the thermal and electrical loads and their interactions. On this basis and taking into account the relationships among the user and the suppliers of electricity, fuels and heat, the energy market structure, the cost of energy and the tax assessment it is possible to properly design Chp plants with benefits for the users [it

Evaluation of an alkaline fuel cell system as a micro-CHP

International Nuclear Information System (INIS)

Verhaert, Ivan; Mulder, Grietus; De Paepe, Michel

2016-01-01

Highlights: • Sensitivity analysis on system configuration of the AFC as a micro-CHP. • Flow rate in the secondary heating circuit can be used to control water management. • Part load behavior of fuel cells is compared to other micro-CHP technologies. • For future energy demand in buildings fuel cells have the best performance. - Abstract: Micro-cogeneration is an emerging technology to reduce the non-renewable energy demand in buildings and reduce peak load in the grid. Fuel cell based cogeneration (CHP) has interesting prospects for building applications, even at relatively low heat demand. This is due to their partial load behavior which is completely different, compared to other micro-CHP technologies. Within the fuel cell technologies suitable for small scale CHP or micro-CHP, the existing configuration of an alkaline fuel cell system is analyzed. This analysis is based on validated models and offers a control strategy to optimize both water management and energy performance of the alkaline fuel cell system. Finally, the model of the alkaline fuel cell system with optimized control strategy is used to compare its part load behavior to other micro-CHP technologies.

Kyoto commitments: CHP will help the UK

International Nuclear Information System (INIS)

Knowles, Michael

1998-01-01

In order to meet the United Kingdom's targets for carbon dioxide emissions reduction, agreed at the Kyoto Summit, the UK Government is promoting the use of combined heat and power (CHP) plants. Such schemes need to offer over 70% efficiency, have on-site or nearby heat uses, and allow flexibility for the export of electricity where this is appropriate. Electricity trading arrangements will need to be re-organised in line with similar commodities, in order to facilitate and promote the growth of CHP and renewable energy schemes. Financial incentives and regulation of electricity prices will also contribute to the promotion of CHP schemes, ultimately leading to reduced CO 2 pollution as a result of the growth in the UK's CHP capacity. (UK)

Development of a Wood Powder Fuelled 35 kW Stirling CHP Unit

DEFF Research Database (Denmark)

Pålsson, M.; Carlsen, Henrik

2003-01-01

For biomass fuelled CHP in sizes below 100 kW, Stirling engines are the only feasible alternative today. Using wood powder as fuel, the Stirling engine can be heated directly by the flame like when using a gaseous or liquid fuel burner. However, the combustion chamber will have to be much larger...... recirculation (CGR) a smaller air preheater can be used, while system efficiency will increase compared with using excess air for flame cooling. In a three-year project, a wood powder fuelled Stirling engine CHP unit will be developed and run in field test. The project will use the double-acting four......-cylinder Stirling engine SM3D with an electric output of 35 kW. This engine is a further development of the engine SM3B that has been developed at the Technical University of Denmark. The engine heater is being adapted for use with wood powder as fuel. During a two-year period a combustion system for this engine...

Survey of controllability in decentralized CHP plants. Optimal operation of priority production units; Kortlaegning af decentrale kraftvarmevaerkers regulerbarhed. Optimal drift af prioriterede anlaeg - Teknologisk grundlag

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-03-15

The present report presents results from two closely related projects, carried out in parallel, under the PSO-F and U 2002. The one project is 'Survey of controllability in de-centralized combined heat and power plants' project number PSO 4724 and is fully reported here. The other project: 'Optimal operation of priority production units, project number PSO 4712, only the part project 'Technological foundations is reported here. In project 4724 the technical conditions that matter regarding controllability of electricity production in de-centralized heat and power stations are surveyed. In this context the term controllability means how fast and to which extent the load factors of the plants can be changed. Also, is has been investigated which options are available for improving the controllability, their potentials and estimates on required investments associated. The investigation covers CHP plants having a production capacity of up to 30 MW of electricity. The main part of the de-centralized CHP plants are based on spark ignited internal combustion engines (Otto engines). Most of these engines are fuelled by natural gas and a smaller part by biogas. A minor number are gas turbines fuelled by natural gas and steam turbines in industrial applications, waste incineration plants or in combined cycle power plants. The mapping has among others consisted of a number of visits on selected different types of plants including interview with people responsible for the daily operation. From these interviews data on the actual operating strategy and technical data have been provided. In addition suppliers of engines and other equipment involved have been contacted for technical information or recommendations regarding possible changes in operation strategy. Searching the Internet has been widely used for identification of technical investigations concerning e.g. operation and maintenance of relevant equipment. Finally, substantial statistical data from

Energy Analysis and Multi-Objective Optimization of an Internal Combustion Engine-Based CHP System for Heat Recovery

Directory of Open Access Journals (Sweden)

Abdolsaeid Ganjehkaviri

2014-10-01

Full Text Available A comprehensive thermodynamic study is conducted of a diesel based Combined Heat and Power (CHP system, based on a diesel engine and an Organic Rankine Cycle (ORC. Present research covers both energy and exergy analyses along with a multi-objective optimization. In order to determine the irreversibilities in each component of the CHP system and assess the system performance, a complete parametric study is performed to investigate the effects of major design parameters and operating conditions on the system’s performance. The main contribution of the current research study is to conduct both exergy and multi-objective optimization of a system using different working fluid for low-grade heat recovery. In order to conduct the evolutionary based optimization, two objective functions are considered in the optimization; namely the system exergy efficiency, and the total cost rate of the system, which is a combination of the cost associated with environmental impact and the purchase cost of each component. Therefore, in the optimization approach, the overall cycle exergy efficiency is maximized satisfying several constraints while the total cost rate of the system is minimized. To provide a better understanding of the system under study, the Pareto frontier is shown for multi-objective optimization and also an equation is derived to fit the optimized point. In addition, a closed form relationship between exergy efficiency and total cost rate is derived.

Optimization of operation for combined heat and power plants - CHP plants - with heat accumulators using a MILP formulation

Energy Technology Data Exchange (ETDEWEB)

Grue, Jeppe; Bach, Inger [Aalborg Univ. (Denmark). Inst. of Energy Technology]. E-mails: jeg@iet.auc.dk; ib@iet.auc.dk

2000-07-01

The power generation system in Denmark is extensively based on small combined heat and power plants (CHP plants), producing both electricity and district heating. This project deals with smaller plants spread throughout the country. Often a heat accumulator is used to enable electricity production, even when the heat demand is low. This system forms a very complex problem, both for sizing, designing and operation of CHP plants. The objective of the work is the development of a tool for optimisation of the operation of CHP plants, and to even considering the design of the plant. The problem is formulated as a MILP-problem. An actual case is being tested, involving CHP producing units to cover the demand. The results from this project show that it is of major importance to consider the operation of the plant in detail already in the design phase. It is of major importance to consider the optimisation of the plant operation, even at the design stage, as it may cause the contribution margin to rise significantly, if the plant is designed on the basis of a de-tailed knowledge of the expected operation. (author)

Methodology for evaluation of industrial CHP production

International Nuclear Information System (INIS)

Pavlovic, Nenad V.; Studovic, Milovan

2000-01-01

At the end of the century industry switched from exclusive power consumer into power consumer-producer which is one of the players on the deregulated power market. Consequently, goals of industrial plant optimization have to be changed, making new challenges that industrial management has to be faced with. In the paper is reviewed own methodology for evaluation of industrial power production on deregulated power market. The methodology recognizes economic efficiency of industrial CHP facilities as a main criterion for evaluation. Energy and ecological efficiency are used as additional criteria, in which implicit could be found social goals. Also, methodology recognizes key and limit factors for CHP production in industry. It could be successful applied, by use of available commercial software for energy simulation in CHP plants and economic evaluation. (Authors)

Modeling of non-linear CHP efficiency curves in distributed energy systems

DEFF Research Database (Denmark)

Milan, Christian; Stadler, Michael; Cardoso, Gonçalo

2015-01-01

Distributed energy resources gain an increased importance in commercial and industrial building design. Combined heat and power (CHP) units are considered as one of the key technologies for cost and emission reduction in buildings. In order to make optimal decisions on investment and operation...... for these technologies, detailed system models are needed. These models are often formulated as linear programming problems to keep computational costs and complexity in a reasonable range. However, CHP systems involve variations of the efficiency for large nameplate capacity ranges and in case of part load operation......, which can be even of non-linear nature. Since considering these characteristics would turn the models into non-linear problems, in most cases only constant efficiencies are assumed. This paper proposes possible solutions to address this issue. For a mixed integer linear programming problem two...

Optimization of a High Temperature PEMFC micro-CHP System by Formulation and Application of a Process Integration Methodology

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2013-01-01

A 1 kWe micro combined heat and power (CHP) system based on high temperature proton exchange membrane fuel cell (PEMFC) technology is modeled and optimized by formulation and application of a process integration methodology. The system can provide heat and electricity for a singlefamily household...

Two-phase optimizing approach to design assessments of long distance heat transportation for CHP systems

International Nuclear Information System (INIS)

Hirsch, Piotr; Duzinkiewicz, Kazimierz; Grochowski, Michał; Piotrowski, Robert

2016-01-01

Highlights: • New method for long distance heat transportation system effectivity evaluation. • Decision model formulation which reflects time and spatial structure of the problem. • Multi-criteria and complex approach to solving the decision-making problem. • Solver based on simulation-optimization approach with two-phase optimization method. • Sensitivity analysis of the optimization procedure elements. - Abstract: Cogeneration or Combined Heat and Power (CHP) for power plants is a method of putting to use waste heat which would be otherwise released to the environment. This allows the increase in thermodynamic efficiency of the plant and can be a source of environmental friendly heat for District Heating (DH). In the paper CHP for Nuclear Power Plant (NPP) is analyzed with the focus on heat transportation. A method for effectivity and feasibility evaluation of the long distance, high power Heat Transportation System (HTS) between the NPP and the DH network is proposed. As a part of the method the multi-criteria decision-making problem, having the structure of the mathematical programming problem, for optimized selection of design and operating parameters of the HTS is formulated. The constraints for this problem include a static model of HTS, that allows considerations of system lifetime, time variability and spatial topology. Thereby variation of annual heat demand within the DH area, variability of ground temperature, insulation and pipe aging and/or terrain elevation profile can be taken into account in the decision-making process. The HTS construction costs, pumping power, and heat losses are considered as objective functions. In general, the analyzed optimization problem is multi-criteria, hybrid and nonlinear. The two-phase optimization based on optimization-simulation framework is proposed to solve the decision-making problem. The solver introduces a number of assumptions concerning the optimization process. Methods for problem decomposition

Benefits of CHP Partnership

Science.gov (United States)

Learn about the benefits of being a EPA CHP Partner, which include expert advice and answers to questions, CHP news, marketing resources, publicity and recognition, and being associated with EPA through a demonstrated commitment to CHP.

Small-scale biomass CHP using gasa turbines: a scoping study

International Nuclear Information System (INIS)

James, D.W.; Landen, R.

1996-01-01

Various options for small-scale (up to 250 KWe) Combined Heat and Power (CHP) plants evaluated in this scoping study. Plants using small gas turbines, and able to use biomass fuels when available are included. Three detailed case studies of small-scale biomass CHP plants are compared to match specific technical options with customer requirements. The commercial development of such biomass-fired CHP units, using gas turbines, is shown to be economically viable depending on fuel costs and the continuation of existing financial incentives. (UK)

Modeling work of a small scale gasifier/SOFC CHP system

Energy Technology Data Exchange (ETDEWEB)

Liu, M.; Aravind, P.V.; Qu, Z.; Woudstra, N.; Verkooijen, A.H.M. [Delft University of Technology (Netherlands). Dept. of Mechanical Engineering], Emails: ming.liu@tudelft.nl, p.v.aravind@tudelft.nl, z.qu@tudelft.nl, n.woudstra@tudelft.nl, a. h. m. verkooijen@tudelft.nl; Cobas, V.R.M. [Federal University of Itajuba (UNIFEI), Pinheirinhos, MG (Brazil). Dept. of Mechanical Engineering], E-mail: vlad@unifei.edu.br

2009-07-01

For a highly efficient biomass gasification/Solid Oxide Fuel Cell (SOFC) Combined Heat and Power (CHP) generation system, the gasifier, the accompanying gas cleaning technologies and the CHP unit must be carefully designed as an integrated unit. This paper describes such a system involving a two-stage fixed-bed down draft gasifier, a SOFC CHP unit and a gas cleaning system. A gas cleaning system with both low temperature and high temperature sections is proposed for coupling the gasifier and the SOFC. Thermodynamic modeling was carried out for the gasifier/SOFC system with the proposed gas cleaning system. The net AC electrical efficiency of this system is around 30% and the overall system efficiency is around 60%. This paper also describes various exergy losses in the system and the future plans for integrated gasifier-GCU-SOFC experiments from which the results will be used to validate the modeling results of this system. (author)

A study on electricity export capability of the μCHP system with spot price

DEFF Research Database (Denmark)

You, Shi; Træholt, Chresten; Poulsen, Bjarne

2009-01-01

of the muCHP unit, which influence the export capability of muCHP system, is firstly carried out in the intraday case study, followed by the annual case study which explores the annual system performance. The results show that the electricity export capability of a muCHP system is closely related to its...

Future market relevance of CHP installations with electrical ratings from 1 to 1000 kW

International Nuclear Information System (INIS)

Eicher, H.; Rigassi, R.

2003-12-01

This report for the Swiss Federal Office of Energy (SFOE) discusses the future market relevance of combined heat and power (CHP) installations with electrical ratings from 1 to 1000 kW. Developments over the past ten years are reviewed. Important reductions in the price of motor-driven CHP units and the price of the electrical power produced are noted and commented on. The technical market potential of CHP units and the degree to which this potential has been implemented are commented on. Work done, including CHP implementation in the industrial, commercial and residential areas, is commented on. Future developments both in the technical area as well as in commercial areas are commented on. Micro-gas-turbine based CHP systems are also discussed, as are fuel-cell based systems in both the higher and lower capacity power generation area. The prospects for CHP systems in general in the electricity generation area are discussed

Mississippi State University Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center

Energy Technology Data Exchange (ETDEWEB)

Mago, Pedro [Mississippi State Univ., Mississippi State, MS (United States); Newell, LeLe [Mississippi State Univ., Mississippi State, MS (United States)

2014-01-31

Between 2008 and 2014, the U.S. Department of Energy funded the MSU Micro-CHP and Bio-Fuel Center located at Mississippi State University. The overall objective of this project was to enable micro-CHP (micro-combined heat and power) utilization, to facilitate and promote the use of CHP systems and to educate architects, engineers, and agricultural producers and scientists on the benefits of CHP systems. Therefore, the work of the Center focused on the three areas: CHP system modeling and optimization, outreach, and research. In general, the results obtained from this project demonstrated that CHP systems are attractive because they can provide energy, environmental, and economic benefits. Some of these benefits include the potential to reduce operational cost, carbon dioxide emissions, primary energy consumption, and power reliability during electric grid disruptions. The knowledge disseminated in numerous journal and conference papers from the outcomes of this project is beneficial to engineers, architects, agricultural producers, scientists and the public in general who are interested in CHP technology and applications. In addition, more than 48 graduate students and 23 undergraduate students, benefited from the training and research performed in the MSU Micro-CHP and Bio-Fuel Center.

Energy versus economic effectiveness in CHP (combined heat and power) applications: Investigation on the critical role of commodities price, taxation and power grid mix efficiency

International Nuclear Information System (INIS)

Comodi, Gabriele; Rossi, Mosè

2016-01-01

Starting from PES (primary energy saving) and CSR (cost saving ratio) definitions the work pinpoints a “grey area” in which CHP (combined heat and power – cogeneration) units can operate with profit and negative PES. In this case, CHP can be profitably operated with lower efficiency with respect to separate production of electrical and thermal energy. The work defines the R-index as the ratio between the cost of fuel and electricity. The optimal value of R-index for which CHP units operate with both environmental benefit (PES > 0) and economic profitability (CSR > 0) is the reference value of electrical efficiency, η_e_l_-_r_e_f, of separate production (national power grid mix). As a consequence, optimal R-index varies from Country to Country. The work demonstrates that the value of R corresponds to the minimum value of electrical efficiency for which any power generator operates with profit. The paper demonstrates that, with regard to the profitability of cogeneration, the ratio between the cost of commodities is more important than their absolute value so that different taxation of each commodity can be a good leverage for energy policy makers to promote high efficiency cogeneration, even in the absence of an incentive mechanism. The final part of the study presents an analysis on micro-CHP technologies payback times for different European Countries. - Highlights: • Investigation of the grey area where CHP profitably operates also with negative PES. • Study starts from definition of primary energy saving PES and cost saving ratio CSR. • Definition of the R-index as the ratio between the cost of fuel and electricity. • The optimal value of R for which the “grey area” disappears is R = η_e_l_-_r_e_f. • R is also the value of η_e_l for which any electric generator profitably operates.

Multi-Objective Analysis of a CHP Plant Integrated Microgrid in Pakistan

Directory of Open Access Journals (Sweden)

Asad Waqar

2017-10-01

Full Text Available In developing countries like Pakistan, the capacity shortage (CS of electricity is a critical problem. The frequent natural gas (NG outages compel consumers to use electricity to fulfill the thermal loads, which ends up as an increase in electrical load. In this scenario, the authors have proposed the concept of a combined heat & power (CHP plant to be a better option for supplying both electrical and thermal loads simultaneously. A CHP plant-based microgrid comprising a PV array, diesel generators and batteries (operating in grid-connected as well as islanded modes has been simulated using the HOMER Pro software. Different configurations of distributed generators (DGs with/without batteries have been evaluated considering multiple objectives. The multiple objectives include the minimization of the total net present cost (TNPC, cost of generated energy (COE and the annual greenhouse gas (GHG emissions, as well as the maximization of annual waste heat recovery (WHR of thermal units and annual grid sales (GS. These objectives are subject to the constraints of power balance, battery operation within state of charge (SOC limits, generator operation within capacity limits and zero capacity shortage. The simulations have been performed on six cities including Islamabad, Lahore, Karachi, Peshawar, Quetta and Gilgit. The simulation results have been analyzed to find the most optimal city for the CHP plant integrated microgrid.

Optimal designs of small CHP plants in a market with fluctuating electricity prices

DEFF Research Database (Denmark)

Lund, Henrik; Andersen, A.N.

2005-01-01

The paper presents the Danish experince with methodologies and software tools, which have been used to design investment and operation strategies for almost all small CHP plants in Denmark during the decade of the triple tariff.......The paper presents the Danish experince with methodologies and software tools, which have been used to design investment and operation strategies for almost all small CHP plants in Denmark during the decade of the triple tariff....

Management of fluctuations in wind power and CHP comparing two possible Danish strategies

International Nuclear Information System (INIS)

Lund, H.; Clark, W.W.

2002-01-01

Both CHP (combined heat and power production) and wind power are important elements of Danish energy policy. Today, approximately 50% of both the Danish electricity and heat demand are produced in CHP and more than 15% of the electricity demand is produced by wind turbines. Both technologies are essential for the implementation of Danish climate change response objectives, and both technologies are intended for further expansion in the coming decade. Meanwhile, the integration of CHP and wind power is subject to fluctuations in electricity production. Wind turbines depend on the wind, and CHP depends on the heat demand. This article discusses and analyses two different national strategies for solving this problem. One strategy, which is the current official government policy known as the export strategy, proposes to take advantage of the Nordic and European markets for selling and buying electricity. In this case, surplus electricity from wind power and CHP simply will be sold to neighbouring countries. Another strategy, the self-supply strategy, runs the CHP units to meet both demand and the fluctuations in the wind scheduling. In this case, investments in heat storages are necessary and heat pumps have to be added to the CHP units. Based on official Danish energy policy and energy plans, this article quantifies the problem for the year 2015 in terms of the amount of surplus electricity, and investments in heat pumps, etc. needed to solve the problem are calculated. Based on these results between the two different strategies, the conclusion is that the self-supply strategy is recommended over the official export strategy. (author)

SOFC/TEG hybrid mCHP system. Final report

Energy Technology Data Exchange (ETDEWEB)

2012-03-15

The starting point for this project have been the challenge has been to develop a cost effective solution with long term stability. This is where a focused effort in a strong consortium covering material research, module development and manufacture as well as device design and optimization can make a real difference. In March 2010 the SOFTEG phase II project was initiated and a cooperation organization was established to implement the project as a development and demonstration project involving the staff from all project partners. The project is now completed with excellent and documented outcome. The final results by Alpcon have been demonstration as a TEG-based mCHP system calls CHP Dual Engine Power System, which will be applicable as both a standalone TEG-CHP hybrid system, but also as an auxiliary power unit and power booster for the SOFC system. However the SOFC system cannot cover the household's heat demand alone so it is necessary to combine a SOFC system together with a water heater/boiler system to cover the peak heat demand of a residential house or a complex building. The SOFTEG project partners achieved significant results that mainly can be outlined as following: 1) University of Aarhus has improved the thermal stability of ZnSb by optimizing the concentration of Nano composite material. 2) The grain size and its influence on the sintering process by spark plasma method are investigated by Aarhus University, but further work seems to be necessary. 3) The TE material is going to commercialization by Aarhus University. 4) Aalborg University has prepared simulation tools for complex thermoelectric simulation in non-steady state condition. 5) The new type DCDC interleaved converter using the MPPT system for optimal power tracing is designed, build and tested by Aalborg University in cooperation with Alpcon. This task is included overall system design, control system implementation and power electronic control design. 6) Full scale practical

Demonstration Stirling Engine based Micro-CHP with ultra-low emissions

Energy Technology Data Exchange (ETDEWEB)

Oeberg, Rolf; Olsson, Fredrik [Carl Bro Energikonsult AB (Sweden); Paalsson, Magnus [Lund Inst. of Technology (Sweden)

2004-03-01

This project has been initiated in order to develop a new type of natural gas fired low emission combustion system for a Stirling engine CHP-unit, and to demonstrate and evaluate the unit with the newly developed combustion system in a CHP application. The Stirling engine technology is well developed, but mostly used in special applications and CHP-applications are scarce. The very low exhaust emissions with the new combustion system would make the Stirling engine very suitable for installation in as a CHP-unit in domestic areas. The Stirling engine used in the project has been a V161 engine produced by Solo Kleinmotoren GmbH in Sindelfingen. The unit has a nominal output of 7,5 kW{sub el} and 20 kW{sub heat} (Hot water). The new combustion system was developed at Lund University and the very strict emission targets that were set up could be achieved, both in the laboratory tests and during the site-testing period. Typical performance and emission figures measured at the site installation are: Generator output (kW): 7,3; Hot water output (kW): 15; El. efficiency (%): 25,4; Total efficiency (%): 77,8; NO{sub x} (ppm): 14; CO (ppm): 112; HC (ppm): < 1; O{sub 2} (%): 8,0; Noise level 1 m from the unit (dBA): 83. The NO{sub x} emissions were reduced with almost 97 % as compared to a standard Stirling combustion system. The emission figures are considerably lower than what could be achieved in an internal combustion engine of similar size with an oxidation catalyst (report SGC 106), while the performance figures are similar for the two technologies. The site testing was carried out during a period of 1,5 year at a site owned by Goeteborg Energi. The site comprises a building structure with workshops, offices etc. covering a ground area of 2,500 m{sup 2}. A gas fired boiler with an output of 250 kW supplies hot water to a local grid for heating and tap water. The annual heat demand is typically 285 MWh and the hot water temperatures are normally 60-80 deg C. The site

A Stochastic Unit Commitment Model for a Local CHP Plant

DEFF Research Database (Denmark)

Ravn, Hans V.; Riisom, Jannik; Schaumburg-Müller, Camilla

2005-01-01

Local CHP development in Denmark has during the 90’s been characterised by large growth primarily due to government subsidies in the form of feed-in tariffs. In line with the liberalisation process in the EU, Danish local CHPs of a certain size must operate on market terms from 2005. This paper...

Hydrocarbon emissions from gas engine CHP-units. 2011 measurement program

Energy Technology Data Exchange (ETDEWEB)

Van Dijk, G.H.J. [KEMA, Arnhem (Netherlands)

2012-06-15

In December 2009, the Ministry of Infrastructure and Environment (IandM) issued the Decree on Emission Limits for Middle Sized Combustion Installations (BEMS). This decree imposes a first-time emission limit value (ELV) of 1500 mg C/m{sup 3}{sub o} at 3% O{sub 2} for hydrocarbons emitted by gas engines. IandM used the findings of two hydrocarbon emission measurement programs, executed in 2007 and 2009, as a guideline for this initial ELV. The programs did reveal substantial variation in the hydrocarbon emissions of the gas engines tested. This variation, and especially the uncertainty as to the role of engine and/or other parameters causing such variation, was felt to hamper further policy development. IandM therefore commissioned KEMA to perform follow-up measurements on ten gas engine CHP-units in 2011. Aim of this 2011 program is to assess hydrocarbon emission variation in relation to engine parameters and process conditions including maintenance status, and to atmospheric conditions. The 2011 program comprised two identical measurement sessions, one in spring and one in winter.

Review of CHP projections tp 2010

Energy Technology Data Exchange (ETDEWEB)

Choudhury, W.

2003-07-01

This report summarises the findings of a study examining market conditions for combined heat and power since 2000 and assessing the commercial position of cogeneration (CHP) in order to provide advice on likely distributed generation in relation to technology, location and commissioning timetables. Details are given of the modelling of the development of 'good quality' CHP by Cambridge Econometrics (CE), and the work carried out by ILEX updating the CE study. Modelling assumptions, market conditions for CHP since the CE study, the effect of market conditions on CE modelling assumptions, justified changes in assumptions, and evaluation of likely CHP capacity to 2010 are discussed.

CHP in Switzerland from 1990 to 1998. Thermal power generation including combined heat and power

International Nuclear Information System (INIS)

Kaufmann, U.

1999-01-01

The results of a study on thermal power generation in Switzerland show that combined heat and power (CHP) systems have grown rapidly. Statistics are presented on the development of CHP-based power and also on thermal power stations without waste heat usage. Figures are given for gas and steam turbine installations, combined gas and steam turbine stations and motor-driven CHP units. Power production is categorised, separating small and large (over 1 Megawatt electrical) power generation facilities. On-site, distributed power generation at consumers' premises and the geographical distribution of plant is described

Deployment of FlexCHP System

Energy Technology Data Exchange (ETDEWEB)

Cygan, David [Gas Technology Inst., Des Plaines, IL (United States)

2015-11-01

The Gas Technology Institute (GTI), along with its partner Integrated CHP Systems Corporation, has developed and demonstrated an Ultra-Low-Nitrogen Oxide (ULN) Flexible Combined Heat and Power (FlexCHP) system that packages a state-of-the-art Capstone C65 gas microturbine and Johnston PFXX100 boiler with an innovative natural gas-fired supplemental burner. Supplemental burners add heat as needed in response to facility demand, which increases energy efficiency, but typically raises exhaust NOx levels, degrading local air quality unless a costly and complicated catalytic treatment system is added. The FlexCHP system increases energy efficiency and achieves the 2007 California Air Resource Board (CARB) distributed generation emissions standards for Nitrogen oxides (NOx), Carbon Monoxide (CO), and Total Hydrocarbons (THC) without catalytic exhaust gas treatment. The key to this breakthrough performance is a simple and reliable burner design which utilizes staged combustion with engineered internal recirculation. This ULN burner system successfully uses turbine exhaust as an oxidizer, while achieving high efficiencies and low emissions. In tests at its laboratory facilities in Des Plaines, Illinois, GTI validated the ability of the system to achieve emissions of NOx, CO, and THC below the CARB criteria of 0.07, 0.10, and 0.02 lb/MW-h respectively. The FlexCHP system was installed at the field demonstration site, Inland Empire Foods, in Riverside, California to verify performance of the technology in an applied environment. The resulting Combined Heat and Power (CHP) package promises to make CHP implementation more attractive, mitigate greenhouse gas emissions, and improve the reliability of electricity supply.

Islanded house operation using a micro CHP

NARCIS (Netherlands)

Molderink, Albert; Bakker, Vincent; Hurink, Johann L.; Smit, Gerardus Johannes Maria

2007-01-01

The µCHP is expected as the successor of the conventional high-efficiency boiler producing next to heat also electricity with a comparable overall efficiency. A µCHP appliance saves money and reduces greenhouse gas emission. An additional functionality of the µCHP is using the appliance as a

Design of Biomass Combined Heat and Power (CHP Systems based on Economic Risk using Minimax Regret Criterion

Directory of Open Access Journals (Sweden)

Ling Wen Choong

2018-01-01

Full Text Available It is a great challenge to identify optimum technologies for CHP systems that utilise biomass and convert it into heat and power. In this respect, industry decision makers are lacking in confidence to invest in biomass CHP due to economic risk from varying energy demand. This research work presents a linear programming systematic framework to design biomass CHP system based on potential loss of profit due to varying energy demand. Minimax Regret Criterion (MRC approach was used to assess maximum regret between selections of the given biomass CHP design based on energy demand. Based on this, the model determined an optimal biomass CHP design with minimum regret in economic opportunity. As Feed-in Tariff (FiT rates affects the revenue of the CHP plant, sensitivity analysis was then performed on FiT rates on the selection of biomass CHP design. Besides, design analysis on the trend of the optimum design selected by model was conducted. To demonstrate the proposed framework in this research, a case study was solved using the proposed approach. The case study focused on designing a biomass CHP system for a palm oil mill (POM due to large energy potential of oil palm biomass in Malaysia.

Carbon emissions reduction potential in the US chemicals and pulp and paper industries by applying CHP technologies

International Nuclear Information System (INIS)

Khrushch, M.; Worrell, E.; Price, L.; Martin, N.; Einstein, D.

1999-01-01

The chemical and the pulp/paper industries combined provide 55% of CHP generation in the US industry. Yet, significant potential for new CHP capacities exists in both industries. From the present steam consumption data, the authors estimate about 50 GW of additional technical potential for CHP in both industries. The reduced carbon emissions will be equivalent to 44% of the present carbon emissions in these industries. They find that most of the carbon emissions reductions can be achieved at negative costs. Depending on the assumptions used in calculations, the economic potential of CHP in these industries can be significantly lower, and carbon emissions mitigation costs can be much higher. Using sensitivity analyses, they determine that the largest effect on the CHP estimate have the assumptions in the costs of CHP technology, in the assumed discount rates, in improvements in efficiency of CHP technologies, and in the CHP equipment depreciation periods. Changes in fuel and electricity prices and the growth in the industries' steam demand have less of an effect. They conclude that the lowest carbon mitigation costs are achieved with the CHP facility is operated by the utility and when industrial company that owns the CHP unit can sell extra electricity and steam to the open wholesale market. Based on the results of the analyses they discuss policy implications

Analysis and optmization of CHP, CCHP, CHP-ORC, and CCHP-ORC systems

Science.gov (United States)

Hueffed, Anna Kathrine

Increased demand for energy, rising energy costs, and heightened environmental concerns are driving forces that continually press for the improvement and development of new technologies to promote energy savings and emissions reduction. Combined heating and power (CHP), combined cooling, heating, and power (CCHP), and organic Rankine cycles (ORC) are a few of the technologies that promise to reduce primary energy consumption (PEC), cost, and emissions. CHP systems generate electricity at or near the place of consumption using a prime mover, e.g. a combustion engine or a turbine, and utilize the accompanying exhaust heat that would otherwise be wasted to satisfy the building's thermal demand. In the case of CCHP systems, exhaust heat also goes to satisfy a cooling load. An organic Rankine cycle (ORC) combined with a CHP or CCHP system can generate electricity from any surplus low-grade heat, thereby reducing the total primary energy, cost, and emissions.

Distributed Control in a Network of Households with microCHP

NARCIS (Netherlands)

Larsen, Gunn; Scherpen, Jacquelien M.A.; van Foreest, Nicolaas

2011-01-01

This is an application of a dynamic price mechanism to distributed optimization of a network of houses which are both producers and consumers of electricity. One possibility for domestic generation is the Micro Combined Heat Power system (µCHP). We use a pricing mechanism based on dual

Grid Interaction of MV-connected CHP-plants during disturbances

NARCIS (Netherlands)

Coster, E.J.; Myrzik, J.M.A.; Kling, W.L.

2009-01-01

Nowadays the amount of distributed generation (DG) units is increasing rapidly. Most dominant are combined heat and power (CHP) plants and wind turbines. At this moment, in most systems, there are no requirements defined for short-circuit behavior of such generators connected to the medium voltage

Decentralised CHP in a competitive market

DEFF Research Database (Denmark)

Lund, Henrik

2004-01-01

The article agues that decentralised CHP plants is an important part of energy supply in Denmark.......The article agues that decentralised CHP plants is an important part of energy supply in Denmark....

Economic analysis of a supercritical coal-fired CHP plant integrated with an absorption carbon capture installation

International Nuclear Information System (INIS)

Bartela, Łukasz; Skorek-Osikowska, Anna; Kotowicz, Janusz

2014-01-01

Energy investments in Poland are currently focused on supercritical coal-fired unit technology. It is likely, that in the future, these units are to be integrated with carbon capture and storage (CCS) installations, which enable a significant reduction of greenhouse gas emissions into the atmosphere. A significant share of the energy market in Poland is constituted by coal-fired combined heat and power (CHP) plants. The integration of these units with CCS installation can be economically inefficient. However, the lack of such integration enhances the investment risk due to the possibility of appearing on the market in the near future high prices of emission allowances. The aforementioned factors and additional favorable conditions for the development of cogeneration can cause one to consider investing in large supercritical CHP plants. This paper presents the results of an economic analysis aimed at comparing three cases of CHP plants, one without an integrated CCS installation and two with such installations. The same steam cycle structure for all variants was adopted. The cases of integrated CHP plants differ from each other in the manner in which they recover heat. For the evaluation of the respective solutions, the break-even price of electricity and avoided emission cost were used. - Highlights: • The simulations of operation of CHP plants under changing load have been realized. • For analyzed cases sensitivity analyses of economic indices have been conducted. • Conditions of competitiveness for integration with CCS units have been identified. • Integration can be profitable if prices of allowance will reach high values, exceeding 50 €/MgCO 2 . • Others important factors are the investment costs and operation and maintenance costs

Dynamic analysis of PEMFC-based CHP systems for domestic application

International Nuclear Information System (INIS)

Barelli, L.; Bidini, G.; Gallorini, F.; Ottaviano, A.

2012-01-01

Highlights: ► Dynamic model of a CHP energy system based on a PEM fuel cell was developed. ► The CHP system behavior at variable electrical and thermal load was investigated. ► The optimal RH value was assessed maximizing PEMFC performance through simulations. ► The system best operating conditions are characterized by a RH value equal to 50%. -- Abstract: Fuel cell-based CHP systems for distributed residential power generation represent an interesting alternative to traditional thermoelectric plants. This is mainly due to the high efficiency obtainable in the production of electricity and heat in a decentralised, quiet and environmental friendly way. The current paper focuses on the development, in Matlab®Simulink environment, of a complete dynamic model of a residential cogenerative (CHP) energy system consisting of the Proton Exchange Membrane fuel cell (PEMFC), fuel processor, heat exchangers, humidifier and auxiliary hot water boiler. The target of the study is the investigation through such a model of the behavior of CHP systems based on fuel cell (FC) at variable electrical and thermal load, in reference to typical load curves of residential users. With the aim to evaluate the system performance (efficiency, fuel consumption, hot water production, response time) and then to characterize its better operating conditions with particular attention to air relative humidity, suitable simulations were carried out. They are characterized by the following of a typical electrical load trend and in relation to two different thermal load profiles. The dynamic model presented in this paper has allowed to observe the fully functioning of the FC based system under variable loads and it has permitted to design appropriate control logics for this system.

Micro CHP: implications for energy companies

Energy Technology Data Exchange (ETDEWEB)

Harrison, Jeremy [EA Technology (United Kingdom); Kolin, Simon; Hestevik, Svein [Sigma Elektroteknisk A/S (Norway)

2000-08-01

This article explains how micro combined heat and power (CHP) technology may help UK energy businesses to maintain their customer base in the current climate of liberalisation and competition in the energy market The need for energy companies to adopt new technologies and adapt to changes in the current aggressive environment, the impact of privatisation, and the switching of energy suppliers by customers are discussed. Three potential routes to success for energy companies are identified, namely, price reductions, branding and affinity marketing, and added value services. Details are given of the implementation of schemes to encourage energy efficiency, the impact of the emissions targets set at Kyoto, the advantages of micro CHP generation, business opportunities for CHP, business threats from existing energy companies and others entering the field, and the commercial viability of micro CHP.

Combined Heat and Power (CHP) Partnership

Science.gov (United States)

The CHP Partnership seeks to reduce air pollution and water usage associated with electric power generation by promoting the use of CHP. The Partnership works to remove policy barriers and to facilitate the development of new projects.

Risk analysis for CHP decision making within the conditions of an open electricity market

International Nuclear Information System (INIS)

Al-Mansour, Fouad; Kozuh, Mitja

2007-01-01

Decision making under uncertainty is a difficult task in most areas. Investment decisions for combined heat and power production (CHP) are certainly one of the areas where it is difficult to find an optimal solution since the payback period is several years and parameters change due to different perturbing factors of economic and mostly political nature. CHP is one of the most effective measures for saving primary energy and reduction of greenhouse gas emissions. The implementation of EU directives on the promotion of cogeneration based on useful heat demand in the internal energy market will accelerate CHP installation. The expected number of small CHP installations will be very high in the near future. A quick, reliable and simple tool for economic evaluation of small CHP systems is required. Since evaluation is normally made by sophisticated economic computer models which are rather expensive, a simple point estimate economic model was developed which was later upgraded by risk methodology to give more informative results for better decision making. This paper presents a reliable computer model entitled 'Computer program for economic evaluation analysis of CHP' as a tool for analysis and economic evaluation of small CHP systems with the aim of helping the decision maker. The paper describes two methods for calculation of the sensitivity of the economic results to changes of input parameters and the uncertainty of the results: the classic/static method and the risk method. The computer program uses risk methodology by applying RISK software on an existing conventional economic model. The use of risk methodology for economic evaluation can improve decisions by incorporating all possible information (knowledge), which cannot be done in the conventional economic model due to its limitations. The methodology was tested on the case of a CHP used in a smaller hospital

Elimination of restraints on the propagation of combined heat and power (CHP) generation systems in Switzerland

International Nuclear Information System (INIS)

Rieder, S.; Landis, F.; Lienhard, A.; Marti Locher, F.; Krummenacher, S.

2009-04-01

This report for the Swiss Federal Office of Energy (SFOE) discusses the results of study initiated by the SFOE that was to investigate the reasons for the low level of proliferation of CHP technology in Switzerland. The two main questions asked - which factors inhibit the use of CHP in particular application areas and which energy-policy measures can remove such obstacles - are discussed. The use of CHP in various areas of application from waste incineration plants through to units used in residential buildings is analysed and commented on. Recommendations on measures that can be taken to enhance the use of CHP are discussed. Three strategy variants available to the public services area are presented and discussed. It is noted that a consensus between players in the technical and political areas is necessary

Small scale CHP: Alternative integration forms in the Danish energy system

International Nuclear Information System (INIS)

Boeg, Rasmus; Gatautis, Ramunas; Engberg Pedersen, Thomas; Schmidt, Rune; Ravn, Hans F.

2003-01-01

In Denmark, introduction of small scale combined heat and power (CHP) plants were part of the energy policy during the 1990's. Thus, the installed electricity capacity on this type of units multiplied approximately ten times during this decade, to constitute more than 2000 MW in 2000, or around 20% of total installed electricity capacity. The motivation for this development was mainly energy savings due to the relatively high thermal efficiency in combined production, and the associated reduction of emissions. The remuneration for the electricity delivered to the electrical network was in part based on a feed in tariff. The construction of the tariff reflected estimated benefits to the electrical system. With the liberalisation of the electricity markets this arrangement has been questioned, and it has been suggested that the differentiated payment to local CHP should be based on electricity market prising. For Denmark this would imply that the local CHP should trade the electricity on the Nordpool electricity spot market. This paper analyses parts of these two alternative ways of economic arrangements in relation to small scale CHP. First it describes the development and status till now. Then it analyses the production patterns and associated economic consequences of a change from the tariff based system to a market system. (BA)

Performance study of an innovative natural gas CHP system

International Nuclear Information System (INIS)

Fu, Lin; Zhao, Xiling; Zhang, Shigang; Li, Yan; Jiang, Yi; Li, Hui; Sun, Zuoliang

2011-01-01

In the last decade, technological innovation and changes in the economic and regulatory environment have resulted in increased attention to distributed energy systems (DES). Combined cooling heating and power (CHP) systems based on the gas-powered internal combustion engine (ICE) are increasingly used as small-scale distribution co-generators. This paper describes an innovative ICE-CHP system with an exhaust-gas-driven absorption heat pump (AHP) that has been set up at the energy-saving building in Beijing, China. The system is composed of an ICE, an exhaust-gas-driven AHP, and a flue gas condensation heat exchanger (CHE), which could recover both the sensible and latent heat of the flue gas. The steady performance and dynamic response of the innovative CHP system with different operation modes were tested. The results show that the system's energy utilization efficiency could reach above 90% based on lower heating value (LHV) of natural gas; that is, the innovative CHP system could increase the heat utilization efficiency 10% compared to conventional CHP systems, and the thermally activated components of the system have much more thermal inertia than the electricity generation component. The detailed test results provide important insight into CHP performance characteristics and could be valuable references for the control of CHP systems. The novel CHP system could take on a very important role in the CHP market. (author)

330 kWe Packaged CHP System with Reduced Emissions

Energy Technology Data Exchange (ETDEWEB)

Plahn, Paul [Cummins Power Generation, Minneapolis, MN (United States); Keene, Kevin [Cummins Power Generation, Minneapolis, MN (United States); Pendray, John [Cummins Power Generation, Minneapolis, MN (United States)

2015-03-31

The objective of this project was to develop a flexible, 330 kWe packaged Combined Heat and Power (CHP) system that can be deployed to commercial and light industrial applications at a lower total cost of ownership than current CHP solutions. The project resulted in a CHP system that is easy to use and inexpensive to install, offering world class customer support, while providing a low-emissions, higher-efficiency internal combustion engine for a CHP system of this size.

Dicty_cDB: CHP827 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available CH (Link to library) CHP827 (Link to dictyBase) - - - Contig-U15898-1 - (Link to Or...iginal site) CHP827F 148 - - - - - - Show CHP827 Library CH (Link to library) Clone ID CHP827 (Link to dicty...Base) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U15898-1 Original site URL http://dictycdb.b...ments: (bits) Value N AC116984 |AC116984.2 Dictyostelium discoideum chromosome 2 map 2567470-3108875 strain ...18q21 clone:RP11-866E20, WORKING DRAFT SEQUENCE, 18 unordered pieces. 42 0.073 4 CK406764 |CK406764.1 AUF_IfLvr_212_c09 Ict

Toxin-antitoxin loci as stress-response-elements: ChpAK/MazF and ChpBK cleave translated RNAs and are counteracted by tmRNA

DEFF Research Database (Denmark)

Christensen, S.K.; Pedersen, K.; Hansen, Flemming G.

2003-01-01

Prokaryotic chromosomes encode toxin-antitoxin loci, often in multiple copies. In most cases, the function of these genes is not known. The chpA (mazEF) locus of Escherichia coli has been described as a cell killing module that induces bacterial apoptosis during nutritional stress. However, we...... found recently that ChpAK (MazF) does not confer cell killing but rather, induces a bacteriostatic condition from which the cells could be resuscitated. Results presented here yield a mechanistic explanation for the detrimental effect on cell growth exerted by ChpAK and the homologous ChpBK protein of E......AK cleaved tmRNA in its coding region. Thus, ChpAK and ChpBK inhibit translation by a mechanism very similar to that of E. coli RelE. On the basis of these results, we propose a model that integrates TA loci into general prokaryotic stress physiology....

Micro-CHP for self-supply in the housing industry. Profitability and system integration; Mikro-BHKW zur Eigenversorgung in der Wohnungswirtschaft. Wirtschaftlichkeit und Systemintegration

Energy Technology Data Exchange (ETDEWEB)

Hollinger, Raphael; Buettner, Markus; Erge, Thomas; Wille-Haussmann, Bernhard; Wittwer, Christof [Fraunhofer-Institut fuer Solare Energiesysteme ISE, Freiburg (Germany)

2011-07-01

The use of micro-CHP units in multifamily buildings is particularly profitable if the produced electricity - coupled with the thermal energy production - is used directly by the operator or sold locally. To maximize the share of own consumption the use of thermal storages to operate the CHP at times of high electrical demand is necessary. By conducting a field test it is shown that the share of own consumption can be increased by predictive control of CHP with thermal storages. The approach increases the profitability of the CHP operation under today's conditions as well as the system integration of the CHP electricity. (orig.)

CHP Partnership Partners

Science.gov (United States)

Partners of EPA's Combined Heat and Power Partnership include federal, state, and local government agencies and private organizations such as energy users, energy service companies, CHP project developers and consultants, and equipment manufacturers.

Micro-CHP systems for residential applications

International Nuclear Information System (INIS)

Paepe, Michel de; D'Herdt, Peter; Mertens, David

2006-01-01

Micro-CHP systems are now emerging on the market. In this paper, a thorough analysis is made of the operational parameters of 3 types of micro-CHP systems for residential use. Two types of houses (detached and terraced) are compared with a two storey apartment. For each building type, the energy demands for electricity and heat are dynamically determined. Using these load profiles, several CHP systems are designed for each building type. Data were obtained for two commercially available gas engines, two Stirling engines and a fuel cell. Using a dynamic simulation, including start up times, these five system types are compared to the separate energy system of a natural gas boiler and buying electricity from the grid. All CHP systems, if well sized, result in a reduction of primary energy use, though different technologies have very different impacts. Gas engines seem to have the best performance. The economic analysis shows that fuel cells are still too expensive and that even the gas engines only have a small internal rate of return (<5%), and this only occurs in favourable economic circumstances. It can, therefore, be concluded that although the different technologies are technically mature, installation costs should at least be reduced by 50% before CHP systems become interesting for residential use. Condensing gas boilers, now very popular in new homes, prove to be economically more interesting and also have a modest effect on primary energy consumption

Combined Heat and Power (CHP) as a Compliance Option under the Clean Power Plan: A Template and Policy Options for State Regulators

Energy Technology Data Exchange (ETDEWEB)

None

2015-07-30

Combined Heat and Power (CHP) is an important option for states to consider in developing strategies to meet their emission targets under the US Environmental Protection Agency's Clean Power Plan. This Template is designed to highlight key issues that states should consider when evaluating whether CHP could be a meaningful component of their compliance plans. It demonstrates that CHP can be a valuable approach for reducing emissions and helping states achieve their targets. While the report does not endorse any particular approach for any state, and actual plans will vary dependent upon state-specific factors and determinations, it provides tools and resources that states can use to begin the process, and underscores the opportunity CHP represents for many states. . By producing both heat and electricity from a single fuel source, CHP offers significant energy savings and carbon emissions benefits over the separate generation of heat and power, with a typical unit producing electricity with half the emissions of conventional generation. These efficiency gains translate to economic savings and enhanced competitiveness for CHP hosts, and emissions reductions for the state, along with helping to lower electric bills; and creating jobs in the design, construction, installation and maintenance of equipment. In 2015, CHP represents 8 percent of electric capacity in the United States and provides 12 percent of total power generation. Projects already exist in all 50 states, but significant technical and economic potential remains. CHP offers a tested way for states to achieve their emission limits while advancing a host of ancillary benefits.

Validation of a HT-PEMFC stack for CHP applications

Energy Technology Data Exchange (ETDEWEB)

Pasupathi, S.; Ulleberg, Oe. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Bujlo, P. [Western Cape Univ. (South Africa). HySA Systems, SAIAMC; Electrotechnical Institute Wroclaw Division (Poland); Scholta, J. [Centre for Solar Energy and Hydrogen Research (ZSW) (Germany)

2010-07-01

Fuel cell systems are very attractive for stationary co-generation applications as they can produce heat and electricity efficiently in a decentralized and environmentally friendly manner. PEMFC stacks operating at temperatures above 120 C, specifically in the range of 140-180 C, are ideal for co-generation purposes. In this study, preliminary results from a HTPEMFC stack designed for CHP applications is presented and discussed. A short, five-cell, HT-PEMFC stack was assembled with Celtec- P-2100 MEAs and validated in terms of electrical performance. The stack was operated with hydrogen and air at 160 C and the utilization curves for anode and cathode were recorded for a wide range of gas utilization at a current density of 0.52 A/cm{sup 2}. The current voltage characteristic was measured at optimal utilization values at 160 C. A 1kW stack is assembled and is currently being validated for its performance under various operating conditions for use in CHP applications. (orig.)

An energetic-exergetic analysis of a residential CHP system based on PEM fuel cell

International Nuclear Information System (INIS)

Barelli, L.; Bidini, G.; Gallorini, F.; Ottaviano, A.

2011-01-01

Highlights: → A zero-dimensional of a micro cogenerative (CHP) energy system based on a Proton Exchange Membrane fuel cell (PEMFC) has been developed. → The electrochemical model has been validated with experimental data. → The performances of this CHP system have been evaluated through a series of simulations. → An energy/exergy analysis of the simulation results has allowed to define the PEMFC optimal operating conditions. → The PEMFC optimal operating conditions detected are: 1 atm, 353.15 K and 100% RH. -- Abstract: The use of fuel cell systems for distributed residential power generation represents an interesting alternative to traditional thermoelectric plants due to their high efficiency and the potential recovering of the heat generated by the internal electrochemical reactions. In this paper the study of a micro cogenerative (CHP) energy system based on a Proton Exchange Membrane fuel cell (PEMFC) is reported. With the aim to evaluate the performance and then the feasibility of this non-conventional energy system, in consideration of thermal and electrical basic demand of a multifamily apartment blocks, a zero-dimensional PEMFC model in Aspen Plus environment has been developed. A simulations sequence has been carried out at different operating conditions of the fuel cell (varying temperature, pressure and relative humidity). Subsequently, on the basis of the obtained results, an energy/exergy analysis has been conducted to define the optimal operating conditions of the PEMFC that ensures the most efficient use of the energy and exergy inputs.

Techno, Economic and Environmental Assessment of a Combined Heat and Power (CHP System—A Case Study for a University Campus

Directory of Open Access Journals (Sweden)

Khuram Pervez Amber

2018-05-01

Full Text Available Universities in the United Kingdom that have installed Combined Heat and Power (CHP technology are making good moves towards achieving their CO2 reduction targets. However, CHP may not always be an economical option for a university campus due to numerous factors. Identification of such factors is highly important before making an investment decision. A detailed technical, economic, and environmental feasibility of CHP is, therefore, indispensable. This study aims to undertake a detailed assessment of CHP for a typical university campus and attempts to highlight the significance of such factors. Necessary data and information were collected through site visits, whereas the CHP sizing was performed using the London South Bank University (LSBU CHP model. The results suggest that there is a strong opportunity of installing a 230 kW CHP that will offset grid electricity and boilers thermal supply by 47% and 75%, respectively, and will generate financial and environmental yearly savings of £51k and 395 t/CO2, respectively. A wider spark gap decreases the payback period of the project and vice versa. The capital cost of the project could affect the project’s economics due to factors, such as unavailability of space for CHP, complex existing infrastructure, and unavailability of a gas connection.

Future market relevance of CHP installations with electrical ratings from 1 to 1000 kW; Zukuenftige Marktbedeutung von WKK-Anlagen mit 1 - 1000 kW elektrischer Leistung

Energy Technology Data Exchange (ETDEWEB)

Eicher, H.; Rigassi, R.

2003-12-15

This report for the Swiss Federal Office of Energy (SFOE) discusses the future market relevance of combined heat and power (CHP) installations with electrical ratings from 1 to 1000 kW. Developments over the past ten years are reviewed. Important reductions in the price of motor-driven CHP units and the price of the electrical power produced are noted and commented on. The technical market potential of CHP units and the degree to which this potential has been implemented are commented on. Work done, including CHP implementation in the industrial, commercial and residential areas, is commented on. Future developments both in the technical area as well as in commercial areas are commented on. Micro-gas-turbine based CHP systems are also discussed, as are fuel-cell based systems in both the higher and lower capacity power generation area. The prospects for CHP systems in general in the electricity generation area are discussed

Increased power to heat ratio of small scale CHP plants using biomass fuels and natural gas

International Nuclear Information System (INIS)

Savola, Tuula; Fogelholm, Carl-Johan

2006-01-01

In this paper, we present a systematic study of process changes for increased power production in 1-20 MW e combined heat and power (CHP) plants. The changes are simulated, and their economic feasibility evaluated by using existing small scale CHP case plants. Increasing power production in decentralised CHP plants that operate according to a certain heat demand could reduce the fuel consumption and CO 2 emissions per power unit produced and improve the feasibility of CHP plant investments. The CHP plant process changes were simulated under design and off design conditions and an analysis of power and heat production, investment costs and CO 2 emissions was performed over the whole annual heat demand. The results show that using biomass fuels, there are profitable possibilities to increase the current power to heat ratios, 0.23-0.48, of the small scale CHP plants up to 0.26-0.56, depending on the size of the plant. The profitable changes were a two stage district heat exchanger and the addition of a steam reheater and a feed water preheater. If natural gas is used as an additional fuel, the power to heat ratio may be increased up to 0.35-0.65 by integrating a gas engine into the process. If the CO 2 savings from the changes are also taken into account, the economic feasibility of the changes increases. The results of this work offer useful performance simulation and investment cost knowledge for the development of more efficient and economically feasible small scale CHP processes

Crystallization and preliminary crystallographic analysis of the human calcineurin homologous protein CHP2 bound to the cytoplasmic region of the Na+/H+ exchanger NHE1

International Nuclear Information System (INIS)

Ben Ammar, Youssef; Takeda, Soichi; Sugawara, Mitsuaki; Miyano, Masashi; Mori, Hidezo; Wakabayashi, Shigeo

2005-01-01

Crystallization of the human CHP2–NHE1 binding domain complex. Calcineurin homologous protein (CHP) is a Ca 2+ -binding protein that directly interacts with and regulates the activity of all plasma-membrane Na + /H + -exchanger (NHE) family members. In contrast to the ubiquitous isoform CHP1, CHP2 is highly expressed in cancer cells. To understand the regulatory mechanism of NHE1 by CHP2, the complex CHP2–NHE1 (amino acids 503–545) has been crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as precipitant. The crystals diffract to 2.7 Å and belong to a tetragonal space group, with unit-cell parameters a = b = 49.96, c = 103.20 Å

Contribution of wind power and CHP to exports from Western Denmark during 2000-2004

International Nuclear Information System (INIS)

Mignard, D.; Harrison, G.P.; Pritchard, C.L.

2007-01-01

The experience of Denmark is used by the United Kingdom's anti-wind lobby to demonstrate that intermittency and inaccuracies in wind forecasting make wind power ineffective and expensive. A further assertion is that most of the power is 'unwanted' since up to 80% of it is exported. Here, available data for Danish energy production for 2000-2004 is used to assess the link between wind generation and exports and test the validity of these claims. Net exports in Western Denmark showed good correlation with wind production. However, they were more significantly correlated with the production from local combined heat and power (CHP) plants. In order to test the 80% export claim, a simple technique was devised to correlate and rank hourly net exports and generation from wind and local CHP. In the case where net exports were primarily attributed to (or blamed on) wind, 44-84% of annual wind production was deemed to be exported, with wind 'causing' 57-79% of net annual exports. For this extreme scenario, the percentage values are in line with those of critics. However, under the opposite extreme scenario in which exports are attributed to local CHP, 77-94% of exports were caused by CHP and only 4-32% of wind production was exported. Overall, this study shows that there is some degree of correlation between net exports and wind power, but that the claim that 80% is exported is unwarranted since it ignores the demonstrably stronger influence of local CHP. (author)

Computer experimental analysis of the CHP performance of a 100 kW e SOFC Field Unit by a factorial design

Science.gov (United States)

Calì, M.; Santarelli, M. G. L.; Leone, P.

Gas Turbine Technologies (GTT) and Politecnico di Torino, both located in Torino (Italy), have been involved in the design and installation of a SOFC laboratory in order to analyse the operation, in cogenerative configuration, of the CHP 100 kW e SOFC Field Unit, built by Siemens-Westinghouse Power Corporation (SWPC), which is at present (May 2005) starting its operation and which will supply electric and thermal power to the GTT factory. In order to take the better advantage from the analysis of the on-site operation, and especially to correctly design the scheduled experimental tests on the system, we developed a mathematical model and run a simulated experimental campaign, applying a rigorous statistical approach to the analysis of the results. The aim of this work is the computer experimental analysis, through a statistical methodology (2 k factorial experiments), of the CHP 100 performance. First, the mathematical model has been calibrated with the results acquired during the first CHP100 demonstration at EDB/ELSAM in Westerwoort. After, the simulated tests have been performed in the form of computer experimental session, and the measurement uncertainties have been simulated with perturbation imposed to the model independent variables. The statistical methodology used for the computer experimental analysis is the factorial design (Yates' Technique): using the ANOVA technique the effect of the main independent variables (air utilization factor U ox, fuel utilization factor U F, internal fuel and air preheating and anodic recycling flow rate) has been investigated in a rigorous manner. Analysis accounts for the effects of parameters on stack electric power, thermal recovered power, single cell voltage, cell operative temperature, consumed fuel flow and steam to carbon ratio. Each main effect and interaction effect of parameters is shown with particular attention on generated electric power and stack heat recovered.

Crystallization and preliminary crystallographic analysis of the human calcineurin homologous protein CHP2 bound to the cytoplasmic region of the Na{sup +}/H{sup +} exchanger NHE1

Energy Technology Data Exchange (ETDEWEB)

Ben Ammar, Youssef [Department of Molecular Physiology, National Cardiovascular Center Research Institute, Fujishiro-dai 5-7-1, Suita, Osaka 565-8565 (Japan); Takeda, Soichi [Department of Cardiac Physiology, National Cardiovascular Center Research Institute, Fujishiro-dai 5-7-1, Suita, Osaka 565-8565 (Japan); Sugawara, Mitsuaki; Miyano, Masashi [Structural Biophysics Laboratory, RIKEN Harima Institute at SPring-8, Kouto, Mikazuki, Sayo, Hyogo 679-5148 (Japan); Mori, Hidezo [Department of Cardiac Physiology, National Cardiovascular Center Research Institute, Fujishiro-dai 5-7-1, Suita, Osaka 565-8565 (Japan); Wakabayashi, Shigeo, E-mail: wak@ri.ncvc.go.jp [Department of Molecular Physiology, National Cardiovascular Center Research Institute, Fujishiro-dai 5-7-1, Suita, Osaka 565-8565 (Japan)

2005-10-01

Crystallization of the human CHP2–NHE1 binding domain complex. Calcineurin homologous protein (CHP) is a Ca{sup 2+}-binding protein that directly interacts with and regulates the activity of all plasma-membrane Na{sup +}/H{sup +}-exchanger (NHE) family members. In contrast to the ubiquitous isoform CHP1, CHP2 is highly expressed in cancer cells. To understand the regulatory mechanism of NHE1 by CHP2, the complex CHP2–NHE1 (amino acids 503–545) has been crystallized by the sitting-drop vapour-diffusion method using PEG 3350 as precipitant. The crystals diffract to 2.7 Å and belong to a tetragonal space group, with unit-cell parameters a = b = 49.96, c = 103.20 Å.

Stockholm CHP potential - An opportunity for CO2 reductions?

International Nuclear Information System (INIS)

Danestig, Maria; Gebremehdin, Alemayehu; Karlsson, Bjoern

2007-01-01

The potential for combined heat and power (CHP) generation in Stockholm is large and a total heat demand of about 10 TWh/year can be met in a renewed large district heating system. This model of the Stockholm district heating system shows that CHP generation can increase from 8% in 2004 to 15.5% of the total electricity generation in Sweden. Increased electricity costs in recent years have awakened an interest to invest in new electricity generation. Since renewable alternatives are favoured by green certificates, bio-fuelled CHP is most profitable at low electricity prices. Since heat demand in the district heating network sets the limit for possible electricity generation, a CHP alternative with a high electricity to heat ratio will be more profitable at when electricity prices are high. The efficient energy use in CHP has the potential to contribute to reductions in carbon dioxide emissions in Europe, when they are required and the European electricity market is working perfectly. The potential in Stockholm exceeds Sweden's undertakings under the Kyoto protocol and national reduction goals. (author)

Experimental study on a project with CHP system basing on absorption cycles

International Nuclear Information System (INIS)

Sun, Jian; Fu, Lin; Sun, Fangtian; Zhang, Shigang

2014-01-01

A new heat recovery system for the CHP (combined heating and power) is presented, and HRU (heat recovery unit) and AHE (absorption heat exchanger) are invented to improve the total energy efficiency of the conventional CHP system by more than 20%, which are installed at the thermal power plant and the heating substation separately. The HRU could recover the low grade heat of exhausted steam from the turbine directly, and the AHE could decrease the temperature of back water of primary pipe to a lower temperature than that of secondary pipe without changing the flow rate of secondary pipe. A large demonstration project employing this technology has been built in Datong of China. And experimental results of HRU and AHE are presented to evaluate this system. - Highlights: • The total energy efficiency of CHP could by increased by more than 20%. • Temperature of back water of primary pipe could be lower than that of secondary pipe. • Heating capacity of primary pipe could be increased significantly. • Low grade heat of exhausted steam from turbine could be recovered directly

CHP expansion strategy in North Rhine-Westphalia. A blueprint for other regions

International Nuclear Information System (INIS)

Holzapfel, Dominik; Schneider, Sabine

2015-01-01

The North Rhine-Westphalian state government intends to increase the share of combined heat and power (CHP) generation to at least 25 % by 2020. Since 2013, the campaign ''CHP.NRW - Power Meets Heat'' (''KWK.NRW - Strom trifft Waerme'') of the EnergyAgency.NRW, is has been running on behalf of the NRW Climate Protection Ministry, to publicise this technology and to promote its expansion. The campaign accompanies the State Government's CHP Stimulus Programme. The EnergyAgency.NRW has organised companies and research institutions, associations and interest groups under the umbrella of ''CHP.NRW - Power Meets Heat'', aiming at co-ordinated and intensified activities in the field of combined heat and power generation. The target of the initial-project ''roadmap/CHP.NRW'' of the ''Virtual Institute / CHP.NRW'' is to develop a guideline for the application and optimisation of CHP-systems.

CHP plant Legionowo Poland. Description of the electricity market in Poland/CHP-feasibility analysis

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-04-01

In 1997, a new energy law was passed in Poland. An important element of the law is that local energy is made obligatory. The law describes obligatory tasks and procedures for the Polish municipalities related to planning and organisation of the energy sector. With the objective of supporting the Polish municipalities in their obligations according to the energy law, the project 'Energy Planning in Poland at Municipal Level - Support to Decision Makers' was launched. As part of the project, Municipal Guideline Reports have been elaborated for three model municipalities. These guidelines present the basis for energy supply plans in the three municipalities. For the city of Legionowo, the following was recommended: 1. The planning processes initiated during the project should be continued/followed up, 2. Master Plan for the district heating system should be prepared, 3. The possibilities of establishment of a major natural gas-fired CHP plant of the combined cycle type should be investigated. The present report describes the electricity market in Poland, the market in which a CHP plant in Legionowo will have to operate. Furthermore the report presents the results of the feasibility analysis carried out for a new CHP plant in Legionowo. (BA)

Micro-CHP Systems for Residential Applications

Energy Technology Data Exchange (ETDEWEB)

Timothy DeValve; Benoit Olsommer

2007-09-30

Integrated micro-CHP (Cooling, Heating and Power) system solutions represent an opportunity to address all of the following requirements at once: conservation of scarce energy resources, moderation of pollutant release into our environment, and assured comfort for home-owners. The objective of this effort was to establish strategies for development, demonstration, and sustainable commercialization of cost-effective integrated CHP systems for residential applications. A unified approach to market and opportunity identification, technology assessment, specific system designs, adaptation to modular product platform component conceptual designs was employed. UTRC's recommendation to U.S. Department of Energy is to go ahead with the execution of the proposed product development and commercialization strategy plan under Phase II of this effort. Recent indicators show the emergence of micro-CHP. More than 12,000 micro-CHP systems have been sold worldwide so far, around 7,500 in 2004. Market projections predict a world-wide market growth over 35% per year. In 2004 the installations were mainly in Europe (73.5%) and in Japan (26.4%). The market in North-America is almost non-existent (0.1%). High energy consumption, high energy expenditure, large spark-spread (i.e., difference between electricity and fuel costs), big square footage, and high income are the key conditions for market acceptance. Today, these conditions are best found in the states of New York, Pennsylvania, New Jersey, Wisconsin, Illinois, Indiana, Michigan, Ohio, New England states. A multiple stage development plan is proposed to address risk mitigation. These stages include concept development and supplier engagement, component development, system integration, system demonstration, and field trials. A two stage commercialization strategy is suggested based on two product versions. The first version--a heat and power system named Micro-Cogen, provides the heat and essential electrical power to the

A Geothermal Energy Supported Gas-steam Cogeneration Unit as a Possible Replacement for the Old Part of a Municipal CHP Plant (TEKO

Directory of Open Access Journals (Sweden)

L. Böszörményi

2001-01-01

Full Text Available The need for more intensive utilization of local renewable energy sources is indisputable. Under the current economic circumstances their competitiveness in comparison with fossil fuels is rather low, if we do not take into account environmental considerations. Integrating geothermal sources into combined heat and power production in a municipal CHP plant would be an excellent solution to this problem. This concept could lead to an innovative type of power plant - a gas-steam cycle based, geothermal energy supported cogeneration unit.

Biomass CHP Catalog of Technologies

Science.gov (United States)

This report reviews the technical and economic characterization of biomass resources, biomass preparation, energy conversion technologies, power production systems, and complete integrated CHP systems.

Evaluation of the impact of the liberalisation of the European electricity market on the CHP, District heating and cooling sector; 'Save CHP/DHC'. Final report

International Nuclear Information System (INIS)

2000-08-01

Improved energy efficiency will play a key role in meeting the EU Kyoto target economically. In addition to a significant positive environmental impact, improved energy efficiency will lead to a more sustainable energy policy and enhanced security of supply. The study: 1) Identifies and evaluates parameters and conditions which in relation to the liberalisation of the electricity market will have an impact on the CHP/DHC sector in EU15 and Poland. 2) Establishes an information base on CHP/DHC systems in EU15 and Poland. 3) Analyses the CHP/DHC sector and its ability to meet changing market conditions. 4) Assesses the effect of the liberalised electricity market on electricity production in relation to CHP/district heating and cooling. 5) Identifies threats for the viability of CHP/DHC in a liberalised market and evaluates means and measures to overcome such threats. The study brings forward the goals and commitments in respect of European energy and environmental policy and gives an overview of the present and expected future framework in which CHP/DHC is to operate. The study evaluates the viability of the sector at an overall level and for different groups/categories of CHP/DHC systems in different countries. The effects of existing or proposed national public measures are analysed. The analyses are essential to decision makers in the transition process towards a fully liberalised market. Recognised uncertainties in the market during the transition period may cause either a temporary or a permanent recession for the CHP/DHC sector. Improved understanding and recognition of threats and opportunities is important to all actors just now. The study can be considered a first step of a process to create a market situation, where the energy customers can make their choices under competition rules and where environmentally friendly and efficient CHP and DHC is considered an attractive business opportunity in competition with other energy supplies. (EHS)

Long-term optimization of cogeneration systems in a competitive market environment

International Nuclear Information System (INIS)

Thorin, E.; Brand, H.; Weber, C.

2005-01-01

A tool for long-term optimization of cogeneration systems is developed that is based on mixed integer linear-programming and Lagrangian relaxation. We use a general approach without heuristics to solve the optimization problem of the unit commitment problem and load dispatch. The possibility to buy and sell electric power at a spot market is considered as well as the possibility to provide secondary reserve. The tool has been tested on a demonstration system based on an existing combined heat-and-power (CHP) system with extraction-condensing steam turbines, gas turbines, and boilers for heat production and district-heating networks. The key feature of the model for obtaining solutions within reasonable times is a suitable division of the whole optimization period into overlapping sub-periods. Using Lagrangian relaxation, the tool can be applied to large CHP systems. For the demonstration model, almost optimal solutions were found. (author)

Optimal portfolio selection between different kinds of Renewable energy sources

Energy Technology Data Exchange (ETDEWEB)

Zakerinia, MohammadSaleh; Piltan, Mehdi; Ghaderi, Farid

2010-09-15

In this paper, selection of the optimal energy supply system in an industrial unit is taken into consideration. This study takes environmental, economical and social parameters into consideration in modeling along with technical factors. Several alternatives which include renewable energy sources, micro-CHP systems and conventional system has been compared by means of an integrated model of linear programming and three multi-criteria approaches (AHP, TOPSIS and ELECTRE III). New parameters like availability of sources, fuels' price volatility, besides traditional factors are considered in different scenarios. Results show with environmental preferences, renewable sources and micro-CHP are good alternatives for conventional systems.

Optimization of Combine Heat and Power Plants in the Russian Wholesale Power Market Conditions

Directory of Open Access Journals (Sweden)

I. A. Chuchueva

2015-01-01

Full Text Available The paper concerns the relevant problem to optimize the combine heat and power (CHP plants in the Russian wholesale power market conditions. Since 1975 the CHP plants specialists faced the problem of fuel rate or fuel cost reduction while ensuring the fixed level of heat and power production. The optimality criterion was the fuel rate or fuel cost which has to be minimized. Produced heat and power was paid by known tariff. Since the power market started in 2006 the power payment scheme has essentially changed: produced power is paid by market price. In such condition a new optimality criterion the paper offers is a profit which has to be maximized for the given time horizon. Depending on the optimization horizon the paper suggests four types of the problem urgency, namely: long-term, mid-term, short-term, and operative optimization. It clearly shows that the previous problem of fuel cost minimization is a special case of profit maximization problem. To bring the problem to the mixed-integer linear programming problem a new linear characteristic curves of steam and gas turbine are introduced. Error of linearization is 0.6%. The formal statement of the problem of short-term CHP plants optimization in the market conditions is offered. The problem was solved with IRM software (OpenLinkInternational for seven power plants of JSC “Quadra”: Dyagilevskaya CHP, Kurskaya CHP-1, Lipetskaya CHP-2, Orlovskaya CHP, Kurskaya CHP NWR, Tambovskaya CHP, and Smolenskaya CHP-2.The conducted computational experiment showed that a potential profit is between 1.7% and 4.7% of the fuel cost of different CHP plants and depends on the power plant operation conditions. The potential profit value is 2–3 times higher than analogous estimations, which were obtained solving fuel cost minimization problem. The perspectives of the work are formalization of mid-term and long-term CHP plants optimization problem and development of domestic software for the new problem

An assessment of the present and future opportunities for combined heat and power with district heating (CHP-DH) in the United Kingdom

International Nuclear Information System (INIS)

Kelly, Scott; Pollitt, Michael

2010-01-01

As global fuel reserves are depleted, alternative and more efficient forms of energy generation and delivery will be required. Combined heat and power with district heating (CHP-DH) provides an alternative energy production and delivery mechanism that is less resource intensive, more efficient and provides greater energy security than many popular alternatives. It will be shown that the economic viability of CHP-DH networks depends on several principles, namely (1) the optimisation of engineering and design principles; (2) organisational and regulatory frameworks; (3) financial and economic factors. It was found that in the long term DH is competitive with other energy supply and distribution technologies such as electricity and gas. However, in the short to medium term it is shown that economic risk, regulatory uncertainty and lock-in of existing technology are the most significant barriers to CHP-DH development. This research suggests that under the present regulatory and economic paradigm, the infrastructure required for DH networks remains financially prohibitive; the implementation of government policies are complicated and impose high transaction costs, while engineering solutions are frequently not implemented or economically optimised. If CHP-DH is going to play any part in meeting climate change targets then collaboration between public and private organisations will be required. It is clear from this analysis that strong local government involvement is therefore necessary for the co-ordination, leadership and infrastructural deployment of CHP-DH.

Multi-criteria evaluation for CHP system options

International Nuclear Information System (INIS)

Pilavachi, P.A.; Roumpeas, C.P.; Minett, S.; Afgan, N.H.

2006-01-01

Several Combined Heat and Power (CHP) system options have been considered for evaluation with respect to the end-user requirements. These included Internal Combustion Engines (Otto and Diesel), Gas Turbines, Steam Turbines and Combined Cycles covering a wide range of electrical output. Data have been obtained from literature and the CHP systems have been evaluated using different criteria such as overall efficiency, investment cost, fuel cost, electricity cost, heat cost, CO 2 production and footprint. A multi-criteria method is used with an agglomeration function based on the statistical evaluation of weight factors. The technical, economic and social aspects of each system have been evaluated in an integrated manner and the results have been compared by means of the Sustainability Index. Based on the above criteria and depending on the user requirements, the best CHP system options have been established

CHP systems to save money and cut carbon.

Science.gov (United States)

Hopkins, Ian

2014-10-01

According to Ian Hopkins, a director of ENER-G Combined Power--which has delivered more than 50 CHP-led energy services contracts within the healthcare sector, having, for the past 30 years, designed and manufactured CHP systems at its global headquarters and R&D centre in Salford--'the energy cost and carbon-saving benefits of combined heat and power are difficult to match where there is a large heating/cooling demand over extended periods'. In this article, he explains how hospitals and other busy healthcare facilities thus 'make ideal bedfellows' for CHP, and outlines the key criteria and considerations, such as sizing, for healthcare engineers, when looking to specify such a system.

Analysis of the impact of Heat-to-Power Ratio for a SOFC-based mCHP system for residential application under different climate regions in Europe

DEFF Research Database (Denmark)

Liso, Vincenzo; Zhao, Yingru; Brandon, Nigel

2011-01-01

In this paper, the ability of a micro combined heat and power (mCHP) system to cover the heat and electricity demand of a single-family residence is investigated. A solid oxide fuel cell based mCHP system coupled with a hot water storage tank is analyzed. The energy profiles of single-family hous......In this paper, the ability of a micro combined heat and power (mCHP) system to cover the heat and electricity demand of a single-family residence is investigated. A solid oxide fuel cell based mCHP system coupled with a hot water storage tank is analyzed. The energy profiles of single...... according to the summer energy demand. The winter energy demand shows a Heat-to-Power Ratio which cannot be covered by the mCHP unit alone. To ensure that the mCHP system meets both the thermal and electrical energy demand over the entire year, an auxiliary boiler and a hot water storage tank need...

Experimental development, 1D CFD simulation and energetic analysis of a 15 kw micro-CHP unit based on reciprocating internal combustion engine

International Nuclear Information System (INIS)

Muccillo, M.; Gimelli, A.

2014-01-01

Cogeneration is commonly recognized as one of the most effective solutions to achieve the increasingly stringent reduction in primary energy consumption and greenhouse emissions. This characteristic led to the adoption of specific directives promoting this technique. In addition, a strategic role in power reliability is recognized to distributed generation. The study and prototyping of cogeneration plants, therefore, has involved many research centres. This paper deals with energetic aspects of CHP referring to the study of a 15 kW micro-CHP plant based on a LPG reciprocating engine designed, built and grid connected. The plant consists of a heat recovery system characterized by a single water circuit recovering heat from exhaust gases, from engine coolant and from the energy radiated by the engine within the shell hosting the plant. Some tests were carried out at whole open throttle and the experimental data were collected. However it was needed to perform a 1D thermo-fluid dynamics simulation of the engine to completely characterize the micro-CHP. As the heat actually recovered depends on the user's thermal load, particularly from the required temperature's level, a comparison of the results for six types of users were performed: residential, hospital, office, commercial, sports, hotel. Both Italian legislative indexes IRE and LT were evaluated, as defined by A.E.E.G resolution n. 42/02 and subsequent updates, as well as the plant's total Primary Energy Saving. - Highlights: • This paper deals with energetic aspects of CHP referring to the study of a 15 kW micro-CHP plant. • The 15 kW micro-CHP plant is based on a GPL reciprocating engine designed, built and grid connected. • Some tests were carried out at whole open throttle and the experimental data were collected. • It was needed to perform a 1D thermo-fluid dynamics simulation of the engine to completely characterize the micro-CHP. • The analysed solution is particularly suited for

Heat Pumps in CHP Systems

DEFF Research Database (Denmark)

Ommen, Torben Schmidt

that three configurations are particular advantageous, whereas the two remaining configurations result in system performance close to or below what may be expected from an electric heater. One of the three advantageous configurations is required to be positioned at the location of the heat demand, whereas...... the two remaining can be located at positions with availability of high temperature sources by utilising the DH network to distribute the heat. A large amount of operational and economic constraints limit the applicability of HPs operated with natural working fluids, which may be the only feasible choice...... representation allows infeasible production. Using MIP or NLP optimisation, the number of operation hours and the total production of heat from HPs are significantly increased, as the HPs may be used to shave the load patterns of CHP units in significantly constrained energy systems. A MIP energy system model...

Is micro-CHP price controllable under price signal controlled Virtual Power Plants?

DEFF Research Database (Denmark)

You, Shi; Træholt, Chresten; Poulsen, Bjarne

2011-01-01

As micro-combined heat and power (micro-CHP) systems move towards mass deployment together with other kinds of distributed energy resources (DER), an increasing emphasis has been placed on how to coordinate such a large diversified DER portfolio in an efficient way by the Virtual Power Plant (VPP...... for three different micro-CHP systems to investigate the feasibility of being controlled by price. Such analysis is relevant for both controller designs for micro-CHP systems and VPP related operations. The results indicate that controlling the micro-CHP systems by price is feasible but could result...

Energetic and environmental performance of three biomass upgrading processes integrated with a CHP plant

International Nuclear Information System (INIS)

Kohl, Thomas; Laukkanen, Timo; Järvinen, Mika; Fogelholm, Carl-Johan

2013-01-01

Highlights: ► We simulate CHP-integrated production of wood pellets, torrefied wood pellets and pyrolysis slurry. ► Integration increases operation hours and district heat output by up to 38% and 22%. ► Additionally installed equipment reduces yearly power generation by up to 7%. ► Wood pellet production performs best energetically and environmentally. ► Integrated concepts substantially reduce fuel consumption and CO 2 emissions. - Abstract: In order to react on future expected increased competition on restricted biomass resources, communal combined heat and power (CHP) plants can be integrated with biomass upgrading processes that add valuable products to the portfolio. In this paper, outgoing from a base case, the retrofit integration of production of wood pellets (WPs), torrefied wood pellets (TWPs) and wood fast pyrolysis slurry (PS) with an existing wood-fired CHP plant was simulated. Within the integration concept, free boiler capacity during times of low district heat demands is used to provide energy for the upgrading processes. By detailed part-load modelling, critical process parameters are discussed. With help of a multiperiod model of the heat duration curve, the work further shows the influence of the integration on plant operating hours, electricity production and biomass throughput. Environmental and energetic performance is assessed according to European standard EN 15603 and compared to the base case as well as to stand-alone production in two separate units. The work shows that all three integration options are well possible within the operational limits of the CHP plant. Summarising, this work shows that integration of WP, TWP and PS production from biomass with a CHP plant by increasing the yearly boiler workload leads to improved primary energy efficiency, reduced CO 2 emissions, and, when compared to stand-alone production, also to substantial fuel savings

ANALYSIS OF CHP POTENTIAL AT FEDERAL SITES

Energy Technology Data Exchange (ETDEWEB)

HADLEY, S.W.

2002-03-11

This document was prepared at the request of the U.S. Department of Energy's (DOE's) Federal Energy Management Program (FEMP) under its Technical Guidance and Assistance and Project Financing Programs. The purpose was to provide an estimate of the national potential for combined heat and power (also known as CHP; cogeneration; or cooling, heating, and power) applications at federal facilities and the associated costs and benefits including energy and emission savings. The report provides a broad overview for the U.S. Department of Energy (DOE) and other agencies on when and where CHP systems are most likely to serve the government's best interest. FEMP's mission is to reduce the cost to and environmental impact of the federal government by advancing energy efficiency and water conservation, promoting the use of renewable energy, and improving utility management decisions at federal sites. FEMP programs are driven by its customers: federal agency sites. FEMP monitors energy efficiency and renewable energy technology developments and mounts ''technology-specific'' programs to make technologies that are in strong demand by agencies more accessible. FEMP's role is often one of helping the federal government ''lead by example'' through the use of advanced energy efficiency/renewable energy (EERE) technologies in its own buildings and facilities. CHP was highlighted in the Bush Administration's National Energy Policy Report as a commercially available technology offering extraordinary benefits in terms of energy efficiencies and emission reductions. FEMP's criteria for emphasizing a technology are that it must be commercially available; be proven but underutilized; have a strong constituency and momentum; offer large energy savings and other benefits of interest to federal sites and FEMP mission; be in demand; and carry sufficient federal market potential. As discussed in the report, CHP meets all

Micro-CHP Technologies Roadmap: Meeting 21st Century Residential Energy Needs

Energy Technology Data Exchange (ETDEWEB)

none,

2003-12-01

On June 11-12, 2003, at Greenbelt, Maryland, key stakeholders from industry, government agencies, universities, and others involved in combined heat and power and the residential buildings industry explores solutions to technical, institutional, and market barriers facing micro-combined heat and power systems (mCHP). Participants outlined a desired future for mCHP systems, identified specific interim technology cost and performance targets, and developed actions to achieve the interim targets and vision. This document, The Micro-CHP Technologies Roadmap, is a result of their deliberations. It outlines a set of actions that can be pursued by both the government and industry to develop mCHP appliances for creating a new approach for households to meet their energy needs.

CHP and District Cooling: An Assessment of Market and Policy Potential in India

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-01

This report contains an assessment of India's CHP/DC status and recommendations for addressing barriers to allow India to meet its energy efficiency targets. Such barriers include a lack of governmental emphasis on CHP, the absence of a clear methodology for calculating CO2 emission reductions from CHP/DHC, and a tax and duty structure for CHP capital equipment that is not as attractive as for other renewable energy technologies.

Investment in new power generation under uncertainty: Benefits of CHP vs. condensing plants in a copula-based analysis

International Nuclear Information System (INIS)

Westner, Günther; Madlener, Reinhard

2012-01-01

In this paper, we apply a spread-based real options approach to analyze the decision-making problem of an investor who has the choice between an irreversible investment in a condensing power plant without heat utilization and a plant with combined heat-and-power (CHP) generation. Our investigation focuses on large-scale fossil-fueled generation technologies and is based on a stochastic model that uses copula functions to provide the input parameters of the real options model. We define the aggregated annual spread as assessment criteria for our investigation since it contains all relevant volatile input parameters that have an impact on the evaluation of investment decisions. We show that the specific characteristics of CHP plants, such as additional revenues from heat sales, promotion schemes, specific operational features, and a beneficial allocation of CO 2 allowances, have a significant impact on the option value and therefore on the optimal timing for investment. For the two fossil-fueled CHP technologies investigated (combined-cycle gas turbine and steam turbine), we conclude from our analysis that a high share of CHP generation reduces the risk exposure for the investor. The maximal possible CHP generation depends significantly on the local heat demand in the surroundings of the power plant. Considering this, the size of the heat sink available could gain more relevance in the future selection process of sites for new large-scale fossil power plants.

The role of combined heat and power (CHP) in energy and climate policy

International Nuclear Information System (INIS)

Conrad, F.

1993-03-01

In the energy- and environment context CHP is said to be especially energy saving and climate preserving. This report shows that from the standpoint of energy economics as well as under technical aspects this judgement holds true only under special conditions. Depending on the technical parameters, the concrete circumstances of operation and the characteristics of the power plants and heating systems compared to CHP-plants the range of realistic energy savings turns out to be very large. Related overstimations are to a good extend caused by the traditional practice of granting the energetic advantage of CHP exclusively to the district heating. If this advantage is credited to heat and power as equal shares space heating with cogenerated power of 80% efficiency reveals to be very energy conserving. The uno actu utilization of cogenerated heat and power, for the same purpose could facilitate the expansion of CHP, since the problems related to the feeding of cogenerated power into the grid for general purposes would disappear. The second main issue of this report concerns the abatement of CO 2 -emissions with the aid of CHP. Fuelled with natural gas, CHP-plants are attractive instruments for climate policy. This is especially true if CHP is compared to old coal-based power plants and oil-fuelled old heating systems. In the FRG, however, hard coal, and not natural gas, will be the main fuel for future CHP, lowering its CO 2 -advantage considerably. On the other hand high efficient combi-power plants (gas turbine plus condensing turbine) and gas heating systems have to be included in the comparative analyse. Compared to these advanced systems the CO 2 -characteristics of CHP are inferior. Moreover, the specific CO 2 -advantage of natural gas is better used by such modern mono systems rather than CHP-plants. (orig.) [de

CHP as a Boiler Replacement Opportunity (Webinar) – April 30, 2013

Science.gov (United States)

This webinar provides information about the benefits of replacing a boiler with a CHP system, describes CHP project analysis and delivery processes, and highlights a case study at Penn State University.

A Study of a Diesel Engine Based Micro-CHP System

Energy Technology Data Exchange (ETDEWEB)

Krishna, C.R.; Andrews, J.; Tutu, N.; Butcher, T.

2010-08-31

systems instead of the conventional heating system, and analyze system approaches for interaction with the local electric utility. The primary energy savings between the space heating provided by a conventional space heating system with all the required electrical energy supplied by the grid and the micro-CHP system supplemented when needed by a conventional space heating and the grid supplied electricity. were calculated for two locations namely Long Island and Albany. The key results from the experimental work are summarized first and the results from the analytical work next. Experimental results: (1) The engine could be operated successfully in the normal and HCCI modes using both diesel and biodiesel blends. (2) The smoke levels are lower with biodiesel than with diesel in both modes of operation. (3) The NOx levels are lower with the HCCI mode of operation than with the normal mode for both fuels. (4) The engine efficiency in these tests is lower in the HCCI mode of operation. However, the system parameters were not optimized for such operation within the scope of this project. However, for an engine designed with such operation in mind, the efficiency would possibly be not lower. Analytical results: (1) The internal combustion engine (diesel engine in this case) is the only proven technology as a prime mover at present. However, as noted above, no U.S. engine is available at present. (2) For both locations, the use of a micro-CHP system results in primary energy savings. This is true whether the CHP system is used only to supply domestic hot water or to supply both hot water and space heat and even for a low efficiency system especially for the latter case. The size of the thermal storage (as long as it above a certain minimum) did not affect this. (3) For example, for a 2 kW CHP electrical efficiency of 25%, a typical house on Long Island will save about 30MBtu of energy per year for a combined space heat and domestic hot water system. This corresponds to annual

Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

Energy Technology Data Exchange (ETDEWEB)

Louay Chamra

2008-09-26

Initially, most micro-CHP systems will likely be designed as constant-power output or base-load systems. This implies that at some point the power requirement will not be met, or that the requirement will be exceeded. Realistically, both cases will occur within a 24-hour period. For example, in the United States, the base electrical load for the average home is approximately 2 kW while the peak electrical demand is slightly over 4 kW. If a 3 kWe micro- CHP system were installed in this situation, part of the time more energy will be provided than could be used and for a portion of the time more energy will be required than could be provided. Jalalzadeh-Azar [6] investigated this situation and presented a comparison of electrical- and thermal-load-following CHP systems. In his investigation he included in a parametric analysis addressing the influence of the subsystem efficiencies on the total primary energy consumption as well as an economic analysis of these systems. He found that an increase in the efficiencies of the on-site power generation and electrical equipment reduced the total monthly import of electricity. A methodology for calculating performance characteristics of different micro-CHP system components will be introduced in this article. Thermodynamic cycles are used to model each individual prime mover. The prime movers modeled in this article are a spark-ignition internal combustion engine (Otto cycle) and a diesel engine (Diesel cycle). Calculations for heat exchanger, absorption chiller, and boiler modeling are also presented. The individual component models are then linked together to calculate total system performance values. Performance characteristics that will be observed for each system include maximum fuel flow rate, total monthly fuel consumption, and system energy (electrical, thermal, and total) efficiencies. Also, whether or not both the required electrical and thermal loads can sufficiently be accounted for within the system

Stirling Energy Module (SEM) as Micro-CHP; Stirling Energy Module (SEM) als Mini-BHKW

Energy Technology Data Exchange (ETDEWEB)

Schlegel, A.

2006-07-01

Since many years, a lot of effort is being put into the development of combined heat and power units (CHP) for the decentralised production of electric power. For long time, the main focus was on fuel cells. In the meantime, the Stirling technology, which is based upon classical mechanical engineering and innovative technical concepts, proceeded in its development as well. The following article describes the technology and the actual state of the development of the Stirling Energy Module (SEM) for the application as Micro-CHP in one-family-houses. SEM is based on a free-piston engine with a linear power generator, producing electric power while heating. The Stirling engine is planned the be introduced into the market as a replacement for the conventional heating systems within a couple of years. (author)

Screening of CHP Potential at Federal Sites in Select Regions of the U.S.

Energy Technology Data Exchange (ETDEWEB)

Energy Nexus Group, . .

2002-02-25

Combined Cooling Heat and Power (CHP) is a master term for onsite power generation technologies that sequentially produce electrical or mechanical energy and useful thermal energy. Some form of CHP has existed for more than 100 years and it is now achieving a greater level of acceptance due to an increasing need for reliable power service and energy cost management. Capturing and using the heat produced as a byproduct of generating electricity from fuel sources increases the usable energy that can be obtained from the original fuel source. CHP technologies have the potential to reduce energy consumption through increased efficiency--decreasing energy bills as well as pollution. The EPA recognizes CHP as a potent climate change mitigation measure. The U.S. Department of Energy (D.O.E.) Federal Energy Management Program (FEMP) is assisting Federal agencies to realize their energy efficiency goals. CHP is an efficiency measure that is receiving growing attention because of its sizable potential to provide efficiency, environmental, and reliability benefits. CHP therefore benefits the host facility, the electric infrastructure, and the U.S. society as a whole. This report and study seeks to make a preliminary inquiry into near term CHP opportunities for federal facilities in selected U.S. regions. It offers to help focus the attention of policy makers and energy facility managers on good candidate facilities for CHP. First, a ranked list of high potential individual sites is identified. Then, several classes of federal facilities are identified for the multiple opportunities they offer as a class. Recommendations are then offered for appropriate next steps for the evaluation and cost effective implementation of CHP. This study was designed to ultimately rank federal facilities in terms of their potential to take advantage of CHP economic and external savings in the near term. In order to best serve the purposes of this study, projections have been expressed in terms of

CHP plant Legionowo Poland - Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-12-01

In 1997, a new Energy Law was passed in Poland. An important element of the law is that local energy planning is made obligatory. The law describes obligatory tasks and procedures for Polish municipalities related to planning and organisation of the energy sector. With the objective of supporting the Polish municipalities in their obligations according to the energy law of 1997, the project 'Energy Planning in Poland at Municipal Level - Support to Decision Makers' was launched. As part of the project, Municipal Guideline Reports have been elaborated for three model municipalities. These guidelines present the basis for the Energy Supply Plans in these municipalities. For the city of Legionowo, the following was recommended: 1. The planning processes initiated during the project should be continues/followed up, 2. Master Plan for the district heating system should be prepared, 3. The possibilities of establishment of a major natural gas-fired CHP plant of the Combined Cycle type should be investigated. The present report is the final Master Plan based on the following reports: Master Plan for Legionowo - Status Report; Master Plan for Legionowo - Hydraulic Analysis; CHP Plant Legionowo Poland - CHP Feasibility Analysis. The final Master Plan describes the status in the DH Company in Legionowo, possible improvements and an investment plan for the selected scenario. (BA)

The Significance of a Building’s Energy Consumption Profiles for the Optimum Sizing of a Combined Heat and Power (CHP System—A Case Study for a Student Residence Hall

Directory of Open Access Journals (Sweden)

Khuram Pervez Amber

2018-06-01

Full Text Available University buildings, such as student residence halls with year-round consistent energy demands, offer strong opportunities for Combined Heat and Power (CHP systems. The economic and environmental feasibility of a CHP project is strongly linked with its optimum sizing. This study aims to undertake such an assessment for a CHP system for a student residence hall located in London, the United Kingdom (UK. The study also aims to undertake a sensitivity analysis to investigate the effect of different parameters on the project’s economics. Necessary data are collected via interviews with the University’s Energy Manager. Modeling of the CHP system is performed using the London South Bank University (LSBU, London, the UK CHP model. Results demonstrate that optimum sizing of CHP is crucial for achieving higher economic and environmental benefits and strongly depends on the authenticity of the energy consumption data, based on which the CHP is being sized. Use of incorrect energy data could result in an undersized or oversized CHP system, where an oversized system will result in higher negative results compared to an undersized system. Finally, Monto Carlo statistical analysis shows that electricity price is the significant factor that could affect the project’s economics. With an increasing spark gap, the payback period decreases, and vice versa.

Modelling Danish local CHP on market conditions

DEFF Research Database (Denmark)

Ravn, Hans V.; Riisom, Jannik; Schaumburg-Müller, Camilla

2004-01-01

with the liberalisation process of the energy sectors of the EU countries, it is however anticipated that Danish local CHP are to begin operating on market conditions within the year 2005. This means that the income that the local CHPs previously gained from selling electricity at the feed-in tariff is replaced in part...... the consequences of acting in a liberalised market for a given CHP plant, based on the abovementioned bottom-up model. The key assumption determining the bottom line is the electricity spot price. The formation of the spot price in the Nordic area depends heavily upon the state of the water reservoirs in Norway...

Optimal Operation of Network-Connected Combined Heat and Powers for Customer Profit Maximization

Directory of Open Access Journals (Sweden)

Da Xie

2016-06-01

Full Text Available Network-connected combined heat and powers (CHPs, owned by a community, can export surplus heat and electricity to corresponding heat and electric networks after community loads are satisfied. This paper proposes a new optimization model for network-connected CHP operation. Both CHPs’ overall efficiency and heat to electricity ratio (HTER are assumed to vary with loading levels. Based on different energy flow scenarios where heat and electricity are exported to the network from the community or imported, four profit models are established accordingly. They reflect the different relationships between CHP energy supply and community load demand across time. A discrete optimization model is then developed to maximize the profit for the community. The models are derived from the intervals determined by the daily operation modes of CHP and real-time buying and selling prices of heat, electricity and natural gas. By demonstrating the proposed models on a 1 MW network-connected CHP, results show that the community profits are maximized in energy markets. Thus, the proposed optimization approach can help customers to devise optimal CHP operating strategies for maximizing benefits.

Hybrid robust predictive optimization method of power system dispatch

Science.gov (United States)

Chandra, Ramu Sharat [Niskayuna, NY; Liu, Yan [Ballston Lake, NY; Bose, Sumit [Niskayuna, NY; de Bedout, Juan Manuel [West Glenville, NY

2011-08-02

A method of power system dispatch control solves power system dispatch problems by integrating a larger variety of generation, load and storage assets, including without limitation, combined heat and power (CHP) units, renewable generation with forecasting, controllable loads, electric, thermal and water energy storage. The method employs a predictive algorithm to dynamically schedule different assets in order to achieve global optimization and maintain the system normal operation.

THE BREAKEVEN POINT GIVEN LIMIT COST USING BIOMASS CHP PLANT

Directory of Open Access Journals (Sweden)

Paula VOICU

2015-06-01

Full Text Available Biomass is a renewable source, non-fossil, from which can be obtained fuels, which can be used in power generation systems. The main difference of fossil fuels is the availability biomass in nature and that it is in continue "reproduction". The use its enable the use of materials that could be destined destruction, as a source of energy "renewable", though result with many ecological values. In this paper we will study, applying a calculation model in view optimal sizing of the cogeneration plant based on biomass, biomass cost limit for the net present value is zero. It will consider that in cogeneration systems and in heating peak systems using biomass. After applying the mathematical model for limit value of biomass cost will determine the nominal optimal coefficient of cogeneration, for which discounted net revenue value is zero. Optimal sizing of CHP plants based on using biomass will be given by optimum coefficient of cogeneration determined following the application of the proposed mathematical model.

Energetic optimization of the performances of a hot air engine for micro-CHP systems working with a Joule or an Ericsson cycle

International Nuclear Information System (INIS)

Creyx, M.; Delacourt, E.; Morin, C.; Desmet, B.; Peultier, P.

2013-01-01

The micro combined heat and electrical power systems (micro-CHP) with hot air engines are well adapted for solid biomass upgrading, in particular, the Ericsson engines working with an open cycle and an external combustion. This paper presents a model of an Ericsson engine with a compression and an expansion cylinder which allows a thermodynamic optimization of the engine performances in a global approach. A sensitive analysis on the influent parameters is carried out in order to determine the optimal working conditions of the engine: temperature and pressure range, expansion cycle shape with a late intake valve closing or an early exhaust valve closing, heat transfers through the wall of the cylinders. This study, focused on thermodynamic aspects, is a first step in the design of an Ericsson engine. -- Highlights: ► A model of Ericsson engine working with a Joule or Ericsson cycle is presented. ► Influent factors on the engine performances are investigated. ► The heat exchanges in the cylinder wall must be avoided to improve the performances. ► Closing the intake valve late and the exhaust valve early enhances the performances. ► Efficiency, indicated mean pressure, specific work are thermodynamically optimized.

Optimal scheduling of coproduction with a storage

International Nuclear Information System (INIS)

Ravn, H.F.; Rygard, J.M.

1993-02-01

We consider the problem of optimal scheduling of a system with combined heat and heat (CHP) units and a heat storege. The purpose of the heat storage is to permit a partial decoupling of the variations in the demand for heat and electrical power. We formulate the problem of optimal scheduling as that of minimizing the total costs over the planning period. The heat demand from the district heating system and the ''shadow prices'' for the electrical power system are taken as externally given parameters. The resulting model is solved by dynamic programming. We describe implementation details and we give examples of result of the optimization. (au) (12 refs.)

Integration of hydrothermal carbonization and a CHP plant: Part 2 –operational and economic analysis

International Nuclear Information System (INIS)

Saari, Jussi; Sermyagina, Ekaterina; Kaikko, Juha; Vakkilainen, Esa; Sergeev, Vitaly

2016-01-01

Wood-fired combined heat and power (CHP) plants are a proven technology for producing domestic, carbon-neutral heat and power in Nordic countries. One drawback of CHP plants is the low capacity factors due to varying heat loads. In the current economic environment, uncertainty over energy prices creates also uncertainty over investment profitability. Hydrothermal carbonization (HTC) is a promising thermochemical conversion technology for producing an improved, more versatile wood-based fuel. Integrating HTC with a CHP plant allows simplifying the HTC process and extending the CHP plant operating time. An integrated polygeneration plant producing three energy products is also less sensitive to price changes in any one product. This study compares three integration cases chosen from the previous paper, and the case of separate stand-alone plants. The best economic performance is obtained using pressurized hot water from the CHP plant boiler drum as HTC process water. This has the poorest efficiency, but allows the greatest cost reduction in the HTC process and longest CHP plant operating time. The result demonstrates the suitability of CHP plants for integration with a HTC process, and the importance of economic and operational analysis considering annual load variations in sufficient detail. - Highlights: • Integration of wood hydrothermal carbonization with a small CHP plant studied. • Operation and economics of three concepts and stand-alone plants are compared. • Sensitivity analysis is performed. • Results show technical and thermodynamic analysis inadequate and misleading alone. • Minimizing HTC investment, extending CHP operating time important for profitability.

MICRO-CHP System for Residential Applications

Energy Technology Data Exchange (ETDEWEB)

Joseph Gerstmann

2009-01-31

This is the final report of progress under Phase I of a project to develop and commercialize a micro-CHP system for residential applications that provides electrical power, heating, and cooling for the home. This is the first phase of a three-phase effort in which the residential micro-CHP system will be designed (Phase I), developed and tested in the laboratory (Phase II); and further developed and field tested (Phase III). The project team consists of Advanced Mechanical Technology, Inc. (AMTI), responsible for system design and integration; Marathon Engine Systems, Inc. (MES), responsible for design of the engine-generator subsystem; AO Smith, responsible for design of the thermal storage and water heating subsystems; Trane, a business of American Standard Companies, responsible for design of the HVAC subsystem; and AirXchange, Inc., responsible for design of the mechanical ventilation and dehumidification subsystem.

Elimination of restraints on the propagation of combined heat and power (CHP) generation systems in Switzerland; Beseitigung von Hemmnissen bei der Verbreitung von Waermekraftkopplung (WKK) in der Schweiz

Energy Technology Data Exchange (ETDEWEB)

Rieder, S.; Landis, F. [Interface Politikstudien Forschung Beratung, Luzern (Switzerland); Lienhard, A.; Marti Locher, F. [Universitaet Bern, Kompetenzzentrum fuer Public Management (KPM), Bern (Switzerland); Krummenacher, S. [Enerprice Partners AG, Technopark Luzern, Root Laengenbold (Switzerland)

2009-04-15

This report for the Swiss Federal Office of Energy (SFOE) discusses the results of study initiated by the SFOE that was to investigate the reasons for the low level of proliferation of CHP technology in Switzerland. The two main questions asked - which factors inhibit the use of CHP in particular application areas and which energy-policy measures can remove such obstacles - are discussed. The use of CHP in various areas of application from waste incineration plants through to units used in residential buildings is analysed and commented on. Recommendations on measures that can be taken to enhance the use of CHP are discussed. Three strategy variants available to the public services area are presented and discussed. It is noted that a consensus between players in the technical and political areas is necessary

Distributed Generation Dispatch Optimization under Various Electricity Tariffs

OpenAIRE

Firestone, Ryan; Marnay, Chris

2007-01-01

The on-site generation of electricity can offer building owners and occupiers financial benefits as well as social benefits such as reduced grid congestion, improved energy efficiency, and reduced greenhouse gas emissions. Combined heat and power (CHP), or cogeneration, systems make use of the waste heat from the generator for site heating needs. Real-time optimal dispatch of CHP systems is difficult to determine because of complicated electricity tariffs and uncertainty in CHP equipment...

Thermodynamic evaluation of CHP (combined heat and power) plants integrated with installations of coal gasification

International Nuclear Information System (INIS)

Ziębik, Andrzej; Malik, Tomasz; Liszka, Marcin

2015-01-01

Integration of a CHP steam plant with an installation of coal gasification and gas turbine leads to an IGCC-CHP (integrated gasification combined cycle-combined heat and power). Two installations of coal gasification have been analyzed, i.e. pressurized entrained flow gasifier – case 1 and pressurized fluidized bed gasifier with CO_2 recirculation – case 2. Basing on the results of mathematical modelling of an IGCC-CHP plant, the algorithms of calculating typical energy indices have been derived. The following energy indices are considered, i.e. coefficient of heat performance and relative savings of chemical energy of fuels. The results of coefficients of heat performance are contained between 1.87 and 2.37. Values exceeding 1 are thermodynamically justified because the idea of cogeneration of heat and electricity based on combining cycles of the heat engine and heat pump the efficiency of which exceeds 1. Higher values concerning waste heat replace more thermodynamically effective sources of heat in CHP plants. Relative savings of the chemical energy of fuels are similar in both cases of IGCC-CHP plants and are contained between the lower value of the CHP (combined heat and power) plants fuelled with coal and higher value of CHP plants fired with natural gas. - Highlights: • Energy savings of fuel is an adequate measure of cogeneration. • Relative energy savings of IGCC-CHP is near the result of a gas and steam CHP. • COHP (coefficient of heat performance) can help to divide fuel between heat fluxes. • Higher values of COHP in the case of waste heat recovery result from the lower thermal parameters.

CHP Integrated with Burners for Packaged Boilers

Energy Technology Data Exchange (ETDEWEB)

Castaldini, Carlo; Darby, Eric

2013-09-30

The objective of this project was to engineer, design, fabricate, and field demonstrate a Boiler Burner Energy System Technology (BBEST) that integrates a low-cost, clean burning, gas-fired simple-cycle (unrecuperated) 100 kWe (net) microturbine (SCMT) with a new ultra low-NOx gas-fired burner (ULNB) into one compact Combined Heat and Power (CHP) product that can be retrofit on new and existing industrial and commercial boilers in place of conventional burners. The Scope of Work for this project was segmented into two principal phases: (Phase I) Hardware development, assembly and pre-test and (Phase II) Field installation and demonstration testing. Phase I was divided into five technical tasks (Task 2 to 6). These tasks covered the engineering, design, fabrication, testing and optimization of each key component of the CHP system principally, ULNB, SCMT, assembly BBEST CHP package, and integrated controls. Phase I work culminated with the laboratory testing of the completed BBEST assembly prior to shipment for field installation and demonstration. Phase II consisted of two remaining technical tasks (Task 7 and 8), which focused on the installation, startup, and field verification tests at a pre-selected industrial plant to document performance and attainment of all project objectives. Technical direction and administration was under the management of CMCE, Inc. Altex Technologies Corporation lead the design, assembly and testing of the system. Field demonstration was supported by Leva Energy, the commercialization firm founded by executives at CMCE and Altex. Leva Energy has applied for patent protection on the BBEST process under the trade name of Power Burner and holds the license for the burner currently used in the product. The commercial term Power Burner is used throughout this report to refer to the BBEST technology proposed for this project. The project was co-funded by the California Energy Commission and the Southern California Gas Company (SCG), a

Generic model of a community-based microgrid integrating wind turbines, photovoltaics and CHP generations

International Nuclear Information System (INIS)

Ma, Xiandong; Wang, Yifei; Qin, Jianrong

2013-01-01

Highlights: ► Proposes a generic microgrid model comprising hybrid distributed generation units. ► Examines DG performance due to both environmental condition changes and electrical faults. ► Addresses island and grid connected modes of operation for DG units. ► We demonstrate the feasibility of the proposed residential microgrid system. - Abstract: Development and deployment of low-carbon energy technologies has been a national strategy of both the UK and China for a number of years, including the use of renewable generation technologies and the improvement of energy efficiency of operations and activities. The paper addresses several issues of generic importance to a residential microgrid system such as network modelling, advanced control and integration of intelligent monitoring techniques. The system, comprising representative distributed generation technologies of photovoltaics, wind turbines and combined heat and power, has been simulated by PSCAD/EMTDC under different operational scenarios. Studies include the effect of environmental condition changes, control systems and power electronics on wind turbines and PV cells, and the mixture of wind/solar/CHP energy generation under dominance of each technology. The performance and dynamics of the system are examined against symmetrical and asymmetrical electrical faults to seek an optimal isolation and restoration of the distributed generation unit from the connected grid system. Modelling these system interactions has demonstrated the feasibility of the proposed residential microgrid system

A microeconomic analysis of decentralized small scale biomass based CHP plants—The case of Germany

International Nuclear Information System (INIS)

Wittmann, Nadine; Yildiz, Özgür

2013-01-01

Alternative energy sources, such as biomass CHP plants, have recently gained significantly in importance and action is due both on the large scale corporate level and on the small scale. Hence, making the scope and economic outline of such projects easily intelligible without losing relevant details seems a key factor to further promote the necessary developments. The model setup presented in this paper may therefore serve as a starting point for generating numerical results based on real life cases or scenarios. Its focus lies on the economic analysis of decentralized biomass CHP plants. It presents a new approach to analyzing the economic aspects of biomass CHP plants implementing a formal microeconomic approach. As Germany claims a leading role in the market for renewable energy production, the paper also takes a closer look on the effects of German energy policy with respect to biomass CHP plants. - Highlights: • A formal microeconomic model is used to analyse a decentralized biomass CHP plant. • Model setup is used to generate numerical results based on real life scenarios. • Nested CES production function is a new approach to model economics of biomass CHP. • Analysis presents insight into microeconomics and cost drivers of biomass CHP. • Evaluation of energy policy design with respect to environmental policy goals

Analysis of the location for peak heating in CHP based combined district heating systems

International Nuclear Information System (INIS)

Wang, Haichao; Lahdelma, Risto; Wang, Xin; Jiao, Wenling; Zhu, Chuanzhi; Zou, Pinghua

2015-01-01

Combined heat and power (CHP) is the main technology for providing the base load of district heating in China. However, CHP is not efficient for providing the peak load; instead, a peak boiler with high efficiency could be used to compensate the peak load. This paper studies how the location of the peak boiler can affect the energy efficiency and economic performance of such CHP based combined district heating system. Firstly, the connection mode and the control strategy for different peak heating locations are analyzed. Then the effect of the peak boiler's location on the initial investment of the network and the cost for distributing heat is studied. The objective is to place the peak boiler in a location where the overall costs are the smallest. Following this rule, the results indicate that the peak boiler should be located at the CHP plant if that allows using cheaper ‘self-use electricity’ in CHP for distributing the heat. However, if the market electricity price is used everywhere, or if energy efficiency is more emphasized, the location of the peak boiler should be closer to the users with dense heat loads. - Highlights: • Location for peak heating in the CHP based combined DH system is studied. • Regulation or control strategies for combined DH are summarized. • The heat load duration curve for combined DH is demonstrated. • Network design for combined DH with peak boiler outside of the CHP is analyzed

DEVELOPMENT OF THE CHP-THERMAL SCHEMES IN CONTEXTS OF THE CONSOLIDATED ENERGY SYSTEM OF BELARUS

Directory of Open Access Journals (Sweden)

V. N. Romaniuk

2015-01-01

Full Text Available The paper deals with the structural specifics of the Belarus Consolidated Energy System capacities in view of their ongoing transfer to the combined-cycle technology, building the nuclear power plant and necessity for the generating capacity regulation in compliance with the load diagram. With the country’s economic complex energy utilization pattern being preserved, the generating capacities are subject to restructuring and the CHP characteristics undergo enhancement inter alia a well-known increase of the specific electricity production based on the heat consumption. Because of this the steam-turbine condensation units which are the traditional capacity regulators for the energy systems with heat power plants dominance are being pushed out of operation. In consequence of this complex of changes the issue of load diagram provision gains momentum which in evidence is relevant to the Consolidated Energy System of Belarus. One of the ways to alleviate acuteness of the problem could be the specific electric energy production cut on the CHP heat consumption with preserving the heat loads and without their handover to the heat generating capacities of direct combustion i.e. without fuel over-burning. The solution lies in integrating the absorption bromous-lithium heat pump units into the CHP thermal scheme. Through their agency low-temperature heat streams of the generator cooling, the lubrication and condensation heat-extraction of steam minimal passing to the condenser systems are utilized. As a case study the authors choose one of the CHPs in the conditions of which the corresponding employment of the said pumps leads to diminution of the fuel-equivalent specific flow-rate by 20−25 g for 1 kW⋅h production and conjoined electric energy generation capacity lowering. The latter will be handed over to other generating capacities, and the choice of them affects economic expediency of the absorption bromous-lithium heat pump-units installation

Alternative depreciation policies for promoting combined heat and power (CHP) development in Brazil

International Nuclear Information System (INIS)

Soares, Jeferson Borghetti; Szklo, Alexandre Salem; Tolmasquim, Mauricio Tiomno

2006-01-01

This paper assessed the economic impact of alternative depreciation methods on the development of combined heat-and-power (CHP) systems in the Brazilian industrial sector. Alternative depreciation methods were proposed and the case study of a Brazilian chemical plant showed that the most effective depreciation method for the promotion of CHP plants in Brazil was the Matheson method with an accelerated depreciation schedule of 7 years. This alternative method was then applied to the Brazilian chemical industry as a whole, increasing its installed capacity in CHP systems by 24%. Therefore, fiscal incentives can be an interesting tool for promoting energy efficiency in the Brazilian industrial sector, promoting the expansion of CHP plants. It reduces government fiscal revenues, but it also induces the technological reposition and improves the feasibility of ventures that are not installed without this kind of incentive

Local CHP Plants between the Natural Gas and Electricity Systems

DEFF Research Database (Denmark)

Bregnbæk, Lars; Schaumburg-Müller, Camilla

2005-01-01

, and they contribute significantly to the electricity production. CHP is, together with the wind power, the almost exclusive distributed generation in Denmark. This paper deals with the CHP as intermediary between the natural gas system and the electricity system. In particular, the relationship between the peak hour......Local combined heat and power (CHP) plants in Denmark constitute an important part of the national energy conversion capacity. In particular they supply a large share of the district heating networks with heat. At the same time they are important consumers as seen from the gas network system...... characteristics of the electricity and gas systems will be investigated. The point is here that the two systems will tend to have peak demand during the same hours. This is the typical situation, since load is high during the same hours of the day and of the year. Moreover, the random variations in the load...

Procuring Stationary Fuel Cells For CHP: A Guide for Federal Facility Decision Makers

Energy Technology Data Exchange (ETDEWEB)

Stinton, David P [ORNL; McGervey, Joseph [SRA International, Inc.; Curran, Scott [ORNL

2011-11-01

Federal agency leaders are expressing growing interest in using innovative fuel cell combined heat and power (CHP) technology at their sites, motivated by both executive branch sustainability targets and a desire to lead by example in the transition to a clean energy economy. Fuel cell CHP can deliver reliable electricity and heat with 70% to 85% efficiency. Implementing this technology can be a high efficiency, clean energy solution for agencies striving to meet ambitious sustainability requirements with limited budgets. Fuel cell CHP systems can use natural gas or renewable fuels, such as biogas. Procuring Stationary Fuel Cells for CHP: A Guide for Federal Facility Decision Makers presents an overview of the process for planning and implementing a fuel cell CHP project in a concise, step-by-step format. This guide is designed to help agency leaders turn their interest in fuel cell technology into successful installations. This guide concentrates on larger (100 kW and greater) fuel cell CHP systems and does not consider other fuel cell applications such as cars, forklifts, backup power supplies or small generators (<100 kW). Because fuel cell technologies are rapidly evolving and have high up front costs, their deployment poses unique challenges. The electrical and thermal output of the CHP system must be integrated with the building s energy systems. Innovative financing mechanisms allow agencies to make a make versus buy decision to maximize savings. This guide outlines methods that federal agencies may use to procure fuel cell CHP systems with little or no capital investment. Each agency and division, however, has its own set of procurement procedures. This guide was written as a starting point, and it defers to the reader s set of rules if differences exist. The fuel cell industry is maturing, and project developers are gaining experience in working with federal agencies. Technology improvements, cost reductions, and experienced project developers are making

An updated assessment of the prospects for fuel cells in stationary power and CHP. An information paper

Energy Technology Data Exchange (ETDEWEB)

Sanderson, T.K. [Future Energy Solutions, Harwell (United Kingdom)

2005-07-01

This report presents updated conclusions of the Department of Trade and Industry's research and development programme to assess the commercial prospects for advanced fuel cells in stationary power and combined heat and power (CHP) systems. The programme has focussed on low temperature solid polymer fuel cells (SPFCs) for transport and combined heat and power (CHP)/distributed power and high temperature solid oxide fuel cells (SOFCs) for CHP/distributed power. As well as assessing the prospects for SPFCs and SOFCs in stationary power and CHP applications, the report examines those for molten carbonate fuel cells (MCFCs) and phosphoric acid fuel cells (PAFCs). The report provides an assessment of the status of technology development for these different types of fuel cells in terms of applications to stationary power and CHP, and offers estimates of market potential for SOFCs in CHP markets, SPFCs in CHP markets and SOFCs in distributed power generation markets. Both large SPFC and SOFC CHP systems require further development to deliver the necessary cost reductions in materials and manufacturing processes before pre-commercial sales can begin. The routes taken by different manufacturers and their choice of preferred technology are explained. A discussion of the prospects and barriers for fuel cell cars concludes that while cost reduction is a major barrier to the successful commercialisation of fuel cells, there are insufficient data available from operating fuel cells systems (other than PAFC) in stationary power and CHP applications to assess the economic attractiveness of fuel cells compared with existing systems. More field trials are required to confirm energy and environmental performance in such applications and to evaluate operational and economic performance under commercial operating conditions. Such field trials could also provide a focus for the required developments in fuel cells for stationary power/CHP systems.

Sizing Combined Heat and Power Units and Domestic Building Energy Cost Optimisation

OpenAIRE

Dongmin Yu; Yuanzhu Meng; Gangui Yan; Gang Mu; Dezhi Li; Simon Le Blond

2017-01-01

Many combined heat and power (CHP) units have been installed in domestic buildings to increase energy efficiency and reduce energy costs. However, inappropriate sizing of a CHP may actually increase energy costs and reduce energy efficiency. Moreover, the high manufacturing cost of batteries makes batteries less affordable. Therefore, this paper will attempt to size the capacity of CHP and optimise daily energy costs for a domestic building with only CHP installed. In this paper, electricity ...

Combustion Turbine CHP System for Food Processing Industry

Energy Technology Data Exchange (ETDEWEB)

None

2010-10-01

This factsheet describes a combined heat and power (CHP) demonstration project that reduces the energy costs and environmental impact of a plant while easing congestion on the constrained Northeast power grid.

Generic Combined Heat and Power (CHP Model for the Concept Phase of Energy Planning Process

Directory of Open Access Journals (Sweden)

Satya Gopisetty

2016-12-01

Full Text Available Micro gas turbines (MGTs are regarded as combined heat and power (CHP units which offer high fuel utilization and low emissions. They are applied in decentralized energy generation. To facilitate the planning process of energy systems, namely in the context of the increasing application of optimization techniques, there is a need for easy-to-parametrize component models with sufficient accuracy which allow a fast computation. In this paper, a model is proposed where the non-linear part load characteristics of the MGT are linearized by means of physical insight of the working principles of turbomachinery. Further, it is shown that the model can be parametrized by the data usually available in spec sheets. With this model a uniform description of MGTs from several manufacturers covering an electrical power range from 30 k W to 333 k W can be obtained. The MGT model was implemented by means of Modelica/Dymola. The resulting MGT system model, comprising further heat exchangers and hydraulic components, was validated using the experimental data of a 65 k W MGT from a trigeneration energy system.

Thermodynamic, ecological and economic aspects of the use of the gas turbine for heat supply to the stripping process in a supercritical CHP plant integrated with a carbon capture installation

International Nuclear Information System (INIS)

Bartela, Łukasz; Skorek-Osikowska, Anna; Kotowicz, Janusz

2014-01-01

Highlights: • Variants of integration of CHP plant with CCS and gas turbine unit were analyzed. • The simulations of operation of plants under changing load were realized. • Conditions of competitiveness for all solutions were identified. • Integration can be profitable if prices of allowance will reach values >60 €/MgCO 2 . - Abstract: This paper presents the results of thermodynamic and economic analyses for eight variants of a combined heat and power (CHP) plant fuelled with coal working under supercritical steam parameters and integrated with a CO 2 capture installation and a gas turbine system. The motivation behind using a gas turbine in the system was to generate steam to supply heat for the stripping process that occurs in the separation installation to regenerate the sorbent. Additional analyses were conducted for the reference case, a CHP unit in which the CO 2 separation process was not conducted, to enable an economic evaluation of the integration of a CHP unit with a CO 2 separation installation according to the variants proposed. The break-even price of electricity and avoided emission costs were used to evaluate the respective solutions. In this paper, the results of the sensitivity analysis of the economic evaluation indicators in terms of the change in the annual operation time, price of emission allowance and heat demand rate for the realization of the stripping process for all cases are presented

Development of Next Generation micro-CHP System

DEFF Research Database (Denmark)

Arsalis, Alexandros

Novel proposals for the modeling and operation of a micro-CHP (combined-heat-andpower) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology are described and analyzed to investigate the technical feasibility of such systems. The proposed systems must...

A family of serine proteases of Clavibacter michiganensis subsp. michiganensis: chpC plays a role in colonization of the host plant tomato.

Science.gov (United States)

Stork, Ines; Gartemann, Karl-Heinz; Burger, Annette; Eichenlaub, Rudolf

2008-09-01

Genes for seven putative serine proteases (ChpA-ChpG) belonging to the trypsin subfamily and homologous to the virulence factor pat-1 were identified on the chromosome of Clavibacter michiganensis subsp. michiganensis (Cmm) NCPPB382. All proteases have signal peptides indicating export of these proteins. Their putative function is suggested by two motifs and an aspartate residue typical for serine proteases. Furthermore, six cysteine residues are located at conserved positions. The genes are clustered in a chromosomal region of about 50 kb with a significantly lower G + C content than common for Cmm. The genes chpA, chpB and chpD are pseudogenes as they contain frame shifts and/or in-frame stop codons. The genes chpC and chpG were inactivated by the insertion of an antibiotic resistance cassette. The chpG mutant was not impaired in virulence. However, in planta the titre of the chpC mutant was drastically reduced and only weak disease symptoms were observed. Complementation of the chpC mutant by the wild-type allele restored full virulence. ChpC is the first chromosomal gene of Cmm identified so far that affects the interaction of the pathogen with the host plant.

Development of HT-PEMFC components and stack for CHP unit

Energy Technology Data Exchange (ETDEWEB)

Jensen, Jens Oluf; Li, Q. (Technical Univ. of Denmark, Dept. of Chemistry, Kgs. Lyngby (Denmark)); Terkelsen, C.; Rudbech, H.C.; Steenberg, T. (Danish Power System Aps, Charlottenlund (Denmark)); Thibault de Rycke (IRD Fuel Cell A/S, Svendborg (Denmark))

2009-10-15

The aim of the project has been to further develop components for an all Danish high temperature PEM fuel cells stack for application in combined heat and power units (CHP units). The final product aimed at was a 1.5-2 kW stack for operation at 150-200 deg. C. The project follows the previous PSO project 4760, 'High Temperature PEM Fuel Cell'. The project has addressed the HT-PEM fuel cells form a components point of view and the materials here for. The main areas were polymer and membrane development, electrode and MEA development (MEA = membrane electrode assembly, i.e. the cells.) and stack development. The membrane development begins with the polymer. The polymerization technique was improved significantly in two ways. Better understanding of the process and the critical issues has led to more reproducible results with repeated high molecular weights. The molecular weight is decisive for the membrane strength and durability. The process was also scaled up to 100-200 g polymer pr. batch in a new polymerization facility build during the project. It is dimensioned for larger batches too, but this was not verified during the project. The polymer cannot be purchased in the right quality for fuel cell membranes and it is important that it manufacture is not a limiting factor at the present state. Experiments with other membrane casting techniques were also made. The traditional PBI doped with phosphoric acid is still the state of art membrane for the HT-PEM fuel cells, but progress was also made with modified membranes. Different variants of PBI were synthesized and tested. Electrodes have been manufactured by a spray technique in contrast to the previously applied tape casting. The hand held spray gun previously led to an improvement of the electrodes, but the reproducibility was limited. Subsequently the construction of a semi automated spray machine was started and results like of the best hand sprayed electrodes were obtained. A viable way of MEA rim

ChpK and MazF of the toxin-antitoxin modules are involved in the virulence of Leptospira interrogans during infection.

Science.gov (United States)

Komi, Komi Koukoura; Ge, Yu-Mei; Xin, Xiao-Yang; Ojcius, David M; Sun, Dexter; Hu, Wei-Lin; Zhao, Xin; Lin, Xu'ai; Yan, Jie

2015-01-01

Pathogenic Leptospira species are the causative agents of leptospirosis, a global zoonotic infectious disease. Toxin-antitoxin (TA) modules have been confirmed as stress-response elements that induce prokaryotic and eukaryotic cell-growth arrest or death, but their role in the virulence of Leptospira has not been reported. Here, we confirmed that all the tested leptospiral strains had the chpIK and mazEF TA modules with highly-conserved sequences. The transcription and expression of the chpI, chpK, mazE, and mazF genes of Leptospira interrogans strain Lai were significantly increased during infection of phorbol 12-myristate 13-acetate-induced human THP-1 macrophages. The toxic ChpK and MazF but not the antitoxic ChpI and MazE proteins were detectable in the cytoplasmic fraction of leptospire-infected THP-1 cells, indicating the external secretion of ChpK and MazF during infection. Transfection of the chpK or mazF gene caused decreased viability and necrosis in THP-1 cells, whereas the chpI or mazE gene transfection did not affect the viability of THP-1 cells but blocked the ChpK or MazF-induced toxicity. Deletion of the chpK or mazF gene also decreased the late-apoptotic and/or necrotic ratios of THP-1 cells at the late stages of infection. The recombinant protein MazF (rMazF) cleaved the RNAs but not the DNAs from Leptospira and THP-1 cells, and this RNA cleavage was blocked by rMazE. However, the rChpK had no RNA or DNA-degrading activity. All these findings indicate that the ChpK and MazF proteins in TA modules are involved in the virulence of L. interrogans during infection. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Modeling and simulation of a residential micro-CHP system based on HT-PEMFC technology

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2009-01-01

Combined-heat-and-power (CHP) technology is a well known and proved method to produce simultaneously power and heat at high efficiencies. This can be further improved by the introduction of a novel micro-CHP residential system based on High Temperature-Proton Exchange Membrane Fuel Cell (HT-PEMFC......). The HT-PEMFC (based on PBI-membrane technology) operates at temperatures near 200oC, and this can be an ideal match for cogeneration residential systems. The proposed system provides electric power, hot water, and space heating for a typical household (1-5 kWe, 5-10 kWth). The micro-CHP system...

Optimal Scheduling of a Multi-Carrier Energy Hub Supplemented By Battery Energy Storage Systems

DEFF Research Database (Denmark)

Javadi, Mohammad Sadegh; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2017-01-01

This paper introduces a management model for optimal scheduling of a multi-carrier energy hub. In the proposed hub, three types of assets are considered: dispersed generating systems (DGs) such as micro-combined heat and power (mCHP) units, storage devices such as battery-based electrical storage...... systems (ESSs), and heating/cooling devices such as electrical heater, heat-pumps and absorption chillers. The optimal scheduling and management of the examined energy hub assets in line with electrical transactions with distribution network is modeled as a mixed-integer non-linear optimization problem....... In this regard, optimal operating points of DG units as well as ESSs are calculated based on a cost-effective strategy. Degradation cost of ESSs is also taken into consideration for short-term scheduling. Simulation results demonstrate that including well-planned energy storage options together with optimal...

Reactive power control with CHP plants - A demonstration

DEFF Research Database (Denmark)

Nyeng, Preben; Østergaard, Jacob; Andersen, Claus A.

2010-01-01

power rating of 7.3 MW on two synchronous generators. A closed-loop control is implemented, that remote controls the CHP plant to achieve a certain reactive power flow in a near-by substation. The solution communicates with the grid operator’s existing SCADA system to obtain measurements from...... lines to underground cables has changed the reactive power balance, and third, the TSO has introduced restrictions in the allowed exchange of reactive power between the transmission system and distribution grids (known as the Mvar-arrangement). The demonstration includes a CHP plant with an electric......In this project the potential for ancillary services provision by distributed energy resources is investigated. Specifically, the provision of reactive power control by combined heat and power plants is examined, and the application of the new standard for DER communication systems, IEC 61850...

New CHP plant for a rubber products manufacturer

International Nuclear Information System (INIS)

Vila, R.; Martí, C.

2016-01-01

At the end of 2014 the company Industrias de Hule Galgo decided to undertake the installation project of an efficient CHP plant for its production plant, with the aim of bringing down energy costs and improving the company’s competitive position in the market. The new plant has already started its first operational phase. The project has comprised the installation of a single cycle with gas-powered gensets providing a total electrical capacity of 6.6 MW. This provides the necessary thermal oil for the production plant; covers 100% of the electrical power consumed by the industrial complex; and also generates cooling water, giving improved production capacity by supercooling the extrusion system. To execute these works, Industrias de Hule Galgo contracted the services of engineering company AESA to provide the engineering, procurement and construction of the CHP plant. (Author)

The Pseudomonas aeruginosa Chp Chemosensory System Regulates Intracellular cAMP Levels by Modulating Adenylate Cyclase Activity

Science.gov (United States)

Fulcher, Nanette B.; Holliday, Phillip M.; Klem, Erich; Cann, Martin J.; Wolfgang, Matthew C.

2010-01-01

Summary Multiple virulence systems in the opportunistic pathogen Pseudomonas aeruginosa are regulated by the second messenger signaling molecule adenosine 3’, 5’-cyclic monophosphate (cAMP). Production of cAMP by the putative adenylate cyclase enzyme CyaB represents a critical control point for virulence gene regulation. To identify regulators of CyaB, we screened a transposon insertion library for mutants with reduced intracellular cAMP. The majority of insertions resulting in reduced cAMP mapped to the Chp gene cluster encoding a putative chemotaxis-like chemosensory system. Further genetic analysis of the Chp system revealed that it has both positive and negative effects on intracellular cAMP and that it regulates cAMP levels by modulating CyaB activity. The Chp system was previously implicated in the production and function of type IV pili (TFP). Given that cAMP and the cAMP-dependent transcriptional regulator Vfr control TFP biogenesis gene expression, we explored the relationship between cAMP, the Chp system and TFP regulation. We discovered that the Chp system controls TFP production through modulation of cAMP while control of TFP-dependent twitching motility is cAMP-independent. Overall, our data define a novel function for a chemotaxis-like system in controlling cAMP production and establish a regulatory link between the Chp system, TFP and other cAMP-dependent virulence systems. PMID:20345659

Changes of the thermodynamic parameters in failure conditions of the micro-CHP cycle

Science.gov (United States)

Matysko, Robert; Mikielewicz, Jarosław; Ihnatowicz, Eugeniusz

2014-03-01

The paper presents the calculations for the failure conditions of the ORC (organic Rankine cycle) cycle in the electrical power system. It analyses the possible reasons of breakdown, such as the electrical power loss or the automatic safety valve failure. The micro-CHP (combined heat and power) system should have maintenance-free configuration, which means that the user does not have to be acquainted with all the details of the ORC system operation. However, the system should always be equipped with the safety control systems allowing for the immediate turn off of the ORC cycle in case of any failure. In case of emergency, the control system should take over the safety tasks and protect the micro-CHP system from damaging. Although, the control systems are able to respond quickly to the CHP system equipped with the inertial systems, the negative effects of failure are unavoidable and always remain for some time. Moreover, the paper presents the results of calculations determining the inertia for the micro-CHP system of the circulating ORC pump, heat removal pump (cooling condenser) and the heat supply pump in failure conditions.

Changes of the thermodynamic parameters in failure conditions of the micro-CHP cycle

Directory of Open Access Journals (Sweden)

Matysko Robert

2014-03-01

Full Text Available The paper presents the calculations for the failure conditions of the ORC (organic Rankine cycle cycle in the electrical power system. It analyses the possible reasons of breakdown, such as the electrical power loss or the automatic safety valve failure. The micro-CHP (combined heat and power system should have maintenance-free configuration, which means that the user does not have to be acquainted with all the details of the ORC system operation. However, the system should always be equipped with the safety control systems allowing for the immediate turn off of the ORC cycle in case of any failure. In case of emergency, the control system should take over the safety tasks and protect the micro-CHP system from damaging. Although, the control systems are able to respond quickly to the CHP system equipped with the inertial systems, the negative effects of failure are unavoidable and always remain for some time. Moreover, the paper presents the results of calculations determining the inertia for the micro-CHP system of the circulating ORC pump, heat removal pump (cooling condenser and the heat supply pump in failure conditions.

Utilization of straw in district heating and CHP plants

International Nuclear Information System (INIS)

Nikolaisen, L.

1993-01-01

In Denmark 64 straw-fired district heating plants and 6 decentral CHP plants have been built since 1980 which are completely or partly straw-fired. The annual straw consumption in the district heating plants is 275,000 tons and in the decentral plants about 200,000 tons. The size of the district heating plants amounts to 0.5 MW - 10 MW and that of the CHP plants to 7 MW - 67 MW heat flow rate. Either whole bales or cut/scarified straw is used for firing. Hesston bales of about 450 kg control the market. The Centre of Biomass Technology is an activity supported 100 % by the Danish Energy Agency with the purpose of increasing the use of straw and wood in the energy supply (orig.)

Environmental sustainability analysis of UK whole-wheat bioethanol and CHP systems

International Nuclear Information System (INIS)

Martinez-Hernandez, Elias; Ibrahim, Muhammad H.; Leach, Matthew; Sinclair, Phillip; Campbell, Grant M.; Sadhukhan, Jhuma

2013-01-01

The UK whole-wheat bioethanol and straw and DDGS-based combined heat and power (CHP) generation systems were assessed for environmental sustainability using a range of impact categories or characterisations (IC): cumulative primary fossil energy (CPE), land use, life cycle global warming potential over 100 years (GWP 100 ), acidification potential (AP), eutrophication potential (EP) and abiotic resources use (ARU). The European Union (EU) Renewable Energy Directive's target of greenhouse gas (GHG) emission saving of 60% in comparison to an equivalent fossil-based system by 2020 seems to be very challenging for stand-alone wheat bioethanol system. However, the whole-wheat integrated system, wherein the CHP from the excess straw grown in the same season and from the same land is utilised in the wheat bioethanol plant, can be demonstrated for potential sustainability improvement, achieving 85% emission reduction and 97% CPE saving compared to reference fossil systems. The net bioenergy from this system and from 172,370 ha of grade 3 land is 12.1 PJ y −1 providing land to energy yield of 70 GJ ha −1 y −1 . The use of DDGS as an animal feed replacing soy meal incurs environmental emission credit, whilst its use in heat or CHP generation saves CPE. The hot spots in whole system identified under each impact category are as follows: bioethanol plant and wheat cultivation for CPE (50% and 48%), as well as for ARU (46% and 52%). EP and GWP 100 are distributed among wheat cultivation (49% and 37%), CHP plant (26% and 30%) and bioethanol plant (25%, and 33%), respectively. -- Highlights: ► UK whole-wheat energy system can achieve 85% GHG emission reduction. ► UK whole-wheat energy system can achieve 97% primary energy saving. ► The land to energy yield of the UK whole-wheat system is 70 GJ ha −1 y −1 . ► Fertiliser production is the hotspot. ► DDGS and straw-based CHP system integration to wheat bioethanol is feasible

Examination of the optimal operation of building scale combined heat and power systems under disparate climate and GHG emissions rates

International Nuclear Information System (INIS)

Howard, B.; Modi, V.

2017-01-01

Highlights: • CHP attributable reductions, not viable by electric generation alone, are defined. • Simplified operating strategy heuristics are optimal under specific circumstances. • Phosphoric acid fuel cells yield the largest reductions except in the extremes. • Changes in baseline emissions affect the optimal system capacity and operating hours. - Abstract: This work aims to elucidate notions concerning the ideal operation and greenhouse gas (GHG) emissions benefits of combined heat and power (CHP) systems by investigating how various metrics change as a function of the GHG emissions from the underlying electricity source, building use type and climate. Additionally, a new term entitled “CHP Attributable” reductions is introduced to quantify the benefits from the simultaneous use of thermal and electric energy, removing benefits achieved solely from fuel switching and generating electricity more efficiently. The GHG emission benefits from implementing internal combustion engine, microturbines, and phosphoric acid (PA) fuel cell based CHP systems were evaluated through an optimization approach considering energy demands of prototypical hospital, office, and residential buildings in varied climates. To explore the effect of electric GHG emissions rates, the ideal operation of the CHP systems was evaluated under three scenarios: “High” GHG emissions rates, “Low” GHG emissions rates, and “Current” GHG emissions rate for a specific location. The analysis finds that PA fuel cells achieve the highest GHG emission reductions in most cases considered, though there are exceptions. Common heuristics, such as electric load following and thermal load following, are the optimal operating strategy under specific conditions. The optimal CHP capacity and operating hours both vary as a function of building type, climate and GHG emissions rates from grid electricity. GHG emissions reductions can be as high as 49% considering a PA fuel cell for a

Optimisation of Combined Cycle Gas Turbine Power Plant in Intraday Market: Riga CHP-2 Example

Science.gov (United States)

Ivanova, P.; Grebesh, E.; Linkevics, O.

2018-02-01

In the research, the influence of optimised combined cycle gas turbine unit - according to the previously developed EM & OM approach with its use in the intraday market - is evaluated on the generation portfolio. It consists of the two combined cycle gas turbine units. The introduced evaluation algorithm saves the power and heat balance before and after the performance of EM & OM approach by making changes in the generation profile of units. The aim of this algorithm is profit maximisation of the generation portfolio. The evaluation algorithm is implemented in multi-paradigm numerical computing environment MATLab on the example of Riga CHP-2. The results show that the use of EM & OM approach in the intraday market can be profitable or unprofitable. It depends on the initial state of generation units in the intraday market and on the content of the generation portfolio.

CHP expansion strategy in North Rhine-Westphalia. A blueprint for other regions; KWK-Ausbaustrategie in NRW. Eine Blaupause fuer andere Regionen

Energy Technology Data Exchange (ETDEWEB)

Holzapfel, Dominik [EnergieAgentur.NRW, Duesseldorf (Germany); Schneider, Sabine [EnergieAgentur.NRW, Wuppertal (Germany)

2015-10-01

The North Rhine-Westphalian state government intends to increase the share of combined heat and power (CHP) generation to at least 25 % by 2020. Since 2013, the campaign ''CHP.NRW - Power Meets Heat'' (''KWK.NRW - Strom trifft Waerme'') of the EnergyAgency.NRW, is has been running on behalf of the NRW Climate Protection Ministry, to publicise this technology and to promote its expansion. The campaign accompanies the State Government's CHP Stimulus Programme. The EnergyAgency.NRW has organised companies and research institutions, associations and interest groups under the umbrella of ''CHP.NRW - Power Meets Heat'', aiming at co-ordinated and intensified activities in the field of combined heat and power generation. The target of the initial-project ''roadmap/CHP.NRW'' of the ''Virtual Institute / CHP.NRW'' is to develop a guideline for the application and optimisation of CHP-systems.

Pilot test and optimization of plasma based DeNO{sub x}. Final report

Energy Technology Data Exchange (ETDEWEB)

Stamate, E.; Chen, W.; Michelsen, P.K. (Risoe DTU. PLF, Roskilde (Denmark)); Joergensen, L.; Jensen, T.K.; Kristensen, P.G.; Tobiasen, L.; Simonsen, P. (Dansk Gasteknisk Center, Hoersholm (Denmark))

2010-12-15

A technique for NO{sub x} reduction for combustion processes was examined. The technique is based on injecting ozone into the NO{sub x} containing flue gas where it will react with NO{sub x}, forming an anhydride of nitric acid, N{sub 2}O{sub 5}. N{sub 2}O{sub 5} is easily removed later using a water scrubber. The technique was tested on a gas engine based CHP unit and a CHP unit based on a straw-fired boiler and a steam turbine. It was found that: 1) NO{sub x} emissions can be reduced by more than 95 % by adding ozone to the flue gas; 2) The technique is applicable on flue gas from biomass combustion despite the presence of compounds such as SO{sub 2} and HCl; 3) Reduction of NO{sub x} emissions requires approximately half as much O{sub 3} when it is applied to the natural gas fired engine unit compared to the straw-fired boiler unit; 4) The higher O{sub 3} consumption on straw-fired units is due both to higher flue gas temperature and to larger NO{sub x} fluctuations in the flue gas compared to the gas engine unit; 5) For the gas engine unit the formaldehyde emission was reduced by 60%; 6) SO{sub 2} emissions are eliminated by the deNO{sub x} unit. It can be concluded that at present the plasma deNO{sub x} process suffers from too high capital and operating costs and too low plant operating time to be an attractive alternative for gas engine CHP plants. Furthermore, there is only a small gap of approx. 25 % between the specific ozone consumption obtained at the pilot test in Ringsted and the theoretically achievable value. This difference is too small to have a major impact on process economy in case of an optimized deNO{sub x} process. At straw fired plants the technology tends to be more promising for several reasons: 1) Significant potential for optimizing specific ozone consumption. 2) Larger NO{sub x} reduction due to the fact that higher concentration levels in the flue gas generate higher income from e.g. fertilizer sales. 3) Reduced or zero SO{sub 2

Ecological assessment of new CHP systems and their combination; Oekologische Bewertung neuer WKK-Systeme und Systemkombinationen - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Primas, A.

2007-07-01

This final report for the Swiss Federal Office of Energy (SFOE) reports on new developments in the Combined Heat and Power (CHP) generation area. The objective of this study is an ecological and technical evaluation of various CHP systems and system combinations. These also include suitable combinations with other technologies. Systems for five different temperature levels are quantified according to their environmental impact. Various possible applications are compared with a highly efficient reference system using separate heat and power generation - a combined-cycle plant and a heat pump. For chilled water production a combination of the CHP system with an absorption chiller is investigated. The results of the investigations are presented and commented on. Also, advantageous applications of CHP systems are noted.

Micro scale CHP based on biomass intelligent heat transfer with thermoelectric generators

Energy Technology Data Exchange (ETDEWEB)

Moser, W.; Aigenbauer, S.; Heckmann, M.; Friedl, G. (Austrian Bioenergy Centre GmbH, Wieselburg (Austria)); Hofbauer, H. (Institute of Chemical Engineering, Vienna University of Technology (Austria))

2007-07-01

Pellet burners need auxiliary electrical power to provide CO{sub 2} balanced heat in a comfortable and environment friendly way. The idea is to produce this and some extra electricity within the device in order to save resources and to gain operation reliability and independency. An option for micro scale CHP is the usage of thermoelectric generators (TEGs). They allow direct conversion of heat into electrical power. They have the advantage of a long maintenance free durability and noiseless operation without moving parts or any working fluid. The useful heat remains almost unaffected and can still be used for heating. TEGs are predestined for the use in micro scale CHP based on solid biomass. In this paper the first results from the fully integrated prototype are presented. The performance of the TEG was observed for different loads and operating conditions in order to realise an optimised micro scale CHP based on solid biomass. (orig.)

Research, Development and Demonstration of Micro-CHP System for Residential Applications

Energy Technology Data Exchange (ETDEWEB)

Karl Mayer

2010-03-31

ECR International and its joint venture company, Climate Energy, are at the forefront of the effort to deliver residential-scale combined heat and power (Micro-CHP) products to the USA market. Part of this substantial program is focused on the development of a new class of steam expanders that offers the potential for significantly lower costs for small-scale power generation technology. The heart of this technology is the scroll expander, a machine that has revolutionized the HVAC refrigerant compressor industry in the last 15 years. The liquid injected cogeneration (LIC) technology is at the core of the efforts described in this report, and remains an excellent option for low cost Micro-CHP systems. ECR has demonstrated in several prototype appliances that the concept for LIC can be made into a practical product. The continuing challenge is to identify economical scroll machine designs that will meet the performance and endurance requirements needed for a long life appliance application. This report describes the numerous advances made in this endeavor by ECR International. Several important advances are described in this report. Section 4 describes a marketing and economics study that integrates the technical performance of the LIC system with real-world climatic data and economic analysis to assess the practical impact that different factors have on the economic application of Micro-CHP in residential applications. Advances in the development of a working scroll steam expander are discussed in Section 5. A rigorous analytical assessment of the performance of scroll expanders, including the difficult to characterize impact of pocket to pocket flank leakage, is presented in Section 5.1. This is followed with an FEA study of the thermal and pressure induced deflections that would result from the normal operation of an advanced scroll expander. Section 6 describes the different scroll expanders and test fixtures developed during this effort. Another key technical

Thermodynamic analysis and experimental investigation of a Solo V161 Stirling cogeneration unit

International Nuclear Information System (INIS)

Rogdakis, E.D.; Antonakos, G.D.; Koronaki, I.P.

2012-01-01

In order to investigate the Stirling engine implementation technology, a Solo Stirling Engine V161 cogeneration module has been installed at the Laboratory of Applied Thermodynamics of National Technical University of Athens. A special thermodynamic analysis of the engine's performance has been conducted introducing and utilizing specially designed computing codes along with the thermal balance study of the unit. Measurements were conducted under different operational conditions concerning various heat load stages of the engine, working pressure, as well as electric power production. Analysis of the experimental results has shown that the overall performance of the Stirling unit proved very promising and quite adequate for various areal applications, equally competing with other CHP systems. The performance of the unit experienced significant stability all over the operating range. The power stand ratio 0.35 differentiates Stirling cogeneration units from others that use diverging technologies significantly. The energy savings using a Stirling CHP unit, in respect to the concurrent use of a thermal and an electrical system at the same equivalent power has revealed 36.8%. -- Highlights: ► Thermodynamic analysis of an a-type Stirling engine. ► Development of generated electrical and thermal power of the m-CHP Solo Stirling Unit to engine's load comparison. ► Stirling m-CHP until heat balance analysis. ► Evaluation of the Solo Stirling V161 unit efficiency.

Optimisation of Combined Cycle Gas Turbine Power Plant in Intraday Market: Riga CHP-2 Example

Directory of Open Access Journals (Sweden)

Ivanova P.

2018-02-01

Full Text Available In the research, the influence of optimised combined cycle gas turbine unit – according to the previously developed EM & OM approach with its use in the intraday market – is evaluated on the generation portfolio. It consists of the two combined cycle gas turbine units. The introduced evaluation algorithm saves the power and heat balance before and after the performance of EM & OM approach by making changes in the generation profile of units. The aim of this algorithm is profit maximisation of the generation portfolio. The evaluation algorithm is implemented in multi-paradigm numerical computing environment MATLab on the example of Riga CHP-2. The results show that the use of EM & OM approach in the intraday market can be profitable or unprofitable. It depends on the initial state of generation units in the intraday market and on the content of the generation portfolio.

MicroCHP: Overview of selected technologies, products and field test results

Energy Technology Data Exchange (ETDEWEB)

Kuhn, Vollrad [Berliner Energieagentur GmbH, Franzoesische Strasse 23, 10117 Berlin (Germany); Klemes, Jiri; Bulatov, Igor [Centre for Process Integration, CEAS, The University of Manchester, P.O. Box 88, M60 1QD Manchester (United Kingdom)

2008-11-15

This paper gives an overview on selected microCHP technologies and products with the focus on Stirling and steam machines. Field tests in Germany, the UK and some other EC countries are presented, assessed and evaluated. Test results show the overall positive performance with differences in sectors (domestic vs. small business). Some negative experiences have been received, especially from tests with the Stirling engines and the free-piston steam machine. There are still obstacles for market implementation. Further projects and tests of microCHP are starting in various countries. When positive results will prevail and deficiencies are eliminated, a way to large-scale production and market implementation could be opened. (author)

Robust Management of Combined Heat and Power Systems via Linear Decision Rules

DEFF Research Database (Denmark)

Zugno, Marco; Morales González, Juan Miguel; Madsen, Henrik

2014-01-01

The heat and power outputs of Combined Heat and Power (CHP) units are jointly constrained. Hence, the optimal management of systems including CHP units is a multicommodity optimization problem. Problems of this type are stochastic, owing to the uncertainty inherent both in the demand for heat and...... linear decision rules to guarantee both tractability and a correct representation of the dynamic aspects of the problem. Numerical results from an illustrative example confirm the value of the proposed approach....

Hybrid Solid Oxide Fuel Cell and Thermoelectric Generator for Maximum Power Output in Micro-CHP Systems

DEFF Research Database (Denmark)

Rosendahl, Lasse; Mortensen, Paw Vestergård; Enkeshafi, Ali A.

2011-01-01

and market segments which are not yet quantified. This paper quantifies a micro-CHP system based on a solid oxide fuel cell (SOFC) and a high-performance TE generator. Based on a 3 kW fuel input, the hybrid SOFC implementation boosts electrical output from 945 W to 1085 W, with 1794 W available for heating...... the electricity production in micro-CHP systems by more than 15%, corresponding to system electrical efficiency increases of some 4 to 5 percentage points. This will make fuel cell-based micro-CHP systems very competitive and profitable and will also open opportunities in a number of other potential business...

Potential for CHP in Africa

International Nuclear Information System (INIS)

Yameogo, Gabriel

2000-01-01

It is suggested that many industries in Africa could benefit from biomass-fired cogeneration so long as the correct structures and learning processes are put in place. The article discusses Africa's energy background and gives figures for generation sources and consumption. A profile of Sudan and its energy needs is presented. It is argued that although some barriers do exist, a move to cogeneration is essential. CHP should be particularly attractive for industries able to use thermal energy for drying, heating and cooling: typical areas would be pharmaceutical and chemical plants, textile factories, cement works and steel mills

IEA Energy Technology Essentials: Biomass for Power Generation and CHP

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-01-15

The IEA Energy Technology Essentials series offers concise four-page updates on the different technologies for producing, transporting and using energy. Biomass for Power Generation and CHP is the topic covered in this edition.

Optimal placement of combined heat and power scheme (cogeneration): application to an ethylbenzene plant

International Nuclear Information System (INIS)

Zainuddin Abd Manan; Lim Fang Yee

2001-01-01

Combined heat and power (CHP) scheme, also known as cogeneration is widely accepted as a highly efficient energy saving measure, particularly in medium to large scale chemical process plants. To date, CHP application is well established in the developed countries. The advantage of a CHP scheme for a chemical plant is two-fold: (i) drastically cut down on the electricity bill from on-site power generation (ii) to save the fuel bills through recovery of the quality waste heat from power generation for process heating. In order to be effective, a CHP scheme must be placed at the right temperature level in the context of the overall process. Failure to do so might render a CHP venture worthless. This paper discusses the procedure for an effective implementation of a CHP scheme. An ethylbenzene process is used as a case study. A key visualization tool known as the grand composite curves is used to provide an overall picture of the process heat source and heat sink profiles. The grand composite curve, which is generated based on the first principles of Pinch Analysis enables the CHP scheme to be optimally placed within the overall process scenario. (Author)

Evaluation of Combined Heat and Power (CHP Systems Using Fuzzy Shannon Entropy and Fuzzy TOPSIS

Directory of Open Access Journals (Sweden)

Fausto Cavallaro

2016-06-01

Full Text Available Combined heat and power (CHP or cogeneration can play a strategic role in addressing environmental issues and climate change. CHP systems require less fuel than separate heat and power systems in order to produce the same amount of energy saving primary energy, improving the security of the supply. Because less fuel is combusted, greenhouse gas emissions and other air pollutants are reduced. If we are to consider the CHP system as “sustainable”, we must include in its assessment not only energetic performance but also environmental and economic aspects, presenting a multicriteria issue. The purpose of the paper is to apply a fuzzy multicriteria methodology to the assessment of five CHP commercial technologies. Specifically, the combination of the fuzzy Shannon’s entropy and the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS approach will be tested for this purpose. Shannon’s entropy concept, using interval data such as the α-cut, is a particularly suitable technique for assigning weights to criteria—it does not require a decision-making (DM to assign a weight to the criteria. To rank the proposed alternatives, a fuzzy TOPSIS method has been applied. It is based on the principle that the chosen alternative should be as close as possible to the positive ideal solution and be as far as possible from the negative ideal solution. The proposed approach provides a useful technical–scientific decision-making tool that can effectively support, in a consistent and transparent way, the assessment of various CHP technologies from a sustainable point of view.

Sizing Combined Heat and Power Units and Domestic Building Energy Cost Optimisation

Directory of Open Access Journals (Sweden)

Dongmin Yu

2017-06-01

Full Text Available Many combined heat and power (CHP units have been installed in domestic buildings to increase energy efficiency and reduce energy costs. However, inappropriate sizing of a CHP may actually increase energy costs and reduce energy efficiency. Moreover, the high manufacturing cost of batteries makes batteries less affordable. Therefore, this paper will attempt to size the capacity of CHP and optimise daily energy costs for a domestic building with only CHP installed. In this paper, electricity and heat loads are firstly used as sizing criteria in finding the best capacities of different types of CHP with the help of the maximum rectangle (MR method. Subsequently, the genetic algorithm (GA will be used to optimise the daily energy costs of the different cases. Then, heat and electricity loads are jointly considered for sizing different types of CHP and for optimising the daily energy costs through the GA method. The optimisation results show that the GA sizing method gives a higher average daily energy cost saving, which is 13% reduction compared to a building without installing CHP. However, to achieve this, there will be about 3% energy efficiency reduction and 7% input power to rated power ratio reduction compared to using the MR method and heat demand in sizing CHP.

Anti-diabetic effect of Cyclo-His-Pro (CHP)-enriched yeast ...

African Journals Online (AJOL)

Anti-diabetic effect of Cyclo-His-Pro (CHP)-enriched yeast hydrolysate in ... The present study was designed to investigate the hypoglycemic effects of the daily ... in the area under curve (AUC) value of YH supplemented groups as compared ...

IVO`s CHP know-how: experience, inventions, patents

Energy Technology Data Exchange (ETDEWEB)

Aeijaelae, M.; Ohtonen, V. [ed.

1997-11-01

IVO can justly claim mastery in the co-generation of district heat and electricity - CHP. As well as looking at the issue from the viewpoint of planners, builders and operators, IVO`s engineers also view power plants through the eyes of the product developer and inventor. This approach has resulted in successful power plant configurations, inventions and patents and visions

Performance and cost results from a DOE Micro-CHP demonstration facility at Mississippi State University

International Nuclear Information System (INIS)

Giffin, Paxton K.

2013-01-01

Highlights: ► We examine the cost and performance results of a Micro-CHP demonstration facility. ► Evaluation includes both summer and winter performance. ► Evaluation in comparison to a conventional HVAC system using grid power. ► Influence of improperly sized equipment. ► Influence of natural gas prices on the viability of CHP projects using that fuel. - Abstract: Cooling, Heating, and Power (CHP) systems have been around for decades, but systems that utilize 20 kW or less, designated as Micro-CHP, are relatively new. A demonstration site has been constructed at Mississippi State University (MSU) to show the advantages of these micro scale systems. This study is designed to evaluate the performance of a Micro-CHP system as opposed to a conventional high-efficiency Heating, Ventilation, and Air Conditioning (HVAC) system that utilizes electrical power from the existing power grid. Raw data was collected for 7 months to present the following results. The combined cycle efficiency from the demonstration site was averaged at 29%. The average combined boiler and engine cost was $1.8 h −1 of operation for heating season and $3.9 h −1 of operation for cooling season. The cooling technology used, an absorption chiller exhibited an average Coefficient of Performance (COP) of 0.27. The conventional high-efficiency system, during cooling season, had a COP of 4.7 with a combined cooling and building cost of $0.2 h −1 of operation. During heating mode, the conventional system had an efficiency of 47% with a fuel and building electrical cost of $0.28 h −1 of operation.

Multi-period MINLP model for optimising operation and structural changes to CHP plants in district heating networks with long-term thermal storage

International Nuclear Information System (INIS)

Tveit, Tor-Martin; Savola, Tuula; Gebremedhin, Alemayehu; Fogelholm, Carl-Johan

2009-01-01

By using thermal storages it is possible to decouple the generation of power and heat, and it can also lead to an reduction in investments, as the storage can be used to cover the peak load periods. This work presents a MINLP model that can be used for analysing new investments and the long-term operation of CHP plants in a district heating network with long-term thermal storage. The model presented in this work includes the non-linear off-design behaviour of the CHP plants as well as a generic mathematical model of the thermal storage, without the need to fix temperatures and pressure. The model is formulated in such a way that it is suitable for deterministic MINLP solvers. The model is non-convex, and subsequently global optimality cannot be guaranteed with local solvers. In order to reduce the chance of obtaining a poor local optimum compared to the global optimum, the model should be solved many times with the initial values varying randomly. It is possible to extract a lot of results from the model, for instance total annual profit, the optimal selection of process options, mass flow through the plant, and generated power from each plant. The formulation of the model makes it suitable for deterministic MINLP solvers

Experimental characterization, modeling and simulation of a wood pellet micro-combined heat and power unit used as a heat source for a residential building

Energy Technology Data Exchange (ETDEWEB)

Thiers, Stephane; Aoun, Bernard; Peuportier, Bruno [MINES ParisTech, CEP - Centre Energetique et Procedes, 60 Boulevard St Michel, 75272 Paris Cedex 06 (France)

2010-06-15

Cogeneration provides heat and power in a more efficient way than separate production. Micro-cogeneration (micro-CHP) is an emerging solution for the improvement of energy and environmental assessments of residential buildings. A wood pellet Stirling engine micro-CHP unit has been studied in order to characterize its annual performance when integrated to a building. First, through a test bench experiment, both transient and steady state behaviors of the micro-CHP unit have been characterized and modeled. Then a more complete model representing a hot water and heating system including the micro-CHP unit and a stratified storage tank has been carried out. This model has been coupled to a building model. A sensitivity analysis by simulation shows that the dimensioning of different elements of the system strongly influences its global energy performance. (author)

Characterization of ultrafine and fine particles from CHP Plants

Energy Technology Data Exchange (ETDEWEB)

2009-08-15

Samples of particles collected at CHP plants in the project 'Survey of emissions from CHP Plants' have been analysed in this project to give information on the morphology and chemical composition of individual particle size classes. The objective of this project was to characterize ultrafine and fine particles emitted to the atmosphere from Danish CHP plants. Nine CHP plants were selected in the Emission Survey Project as being representative for the different types of CHP plants operating in Denmark: 1) Three Waste-to Energy (WTE) plants. 2) Three biomass fired (BM) plants (two straw fired, one wood/saw dust fired). 3) Two gas fired (GF) plants (one natural gas, one landfill gas fired). 4) One gasoil (GO) fired plant. At the WTE and BM plants, various types of emission control systems implemented. The results from these plants represent the composition and size distribution of combustion particles that are emitted from the plants emission control systems. The measured emissions of particles from the waste-to-energy plants WTE1-3 are generally very low. The number and mass concentrations of ultrafine particles (PM{sub 0.1}) were particularly low in the flue gas from WTE2 and WTE3, where bag filters are used for the reduction of particle emissions. The EDX analysis of particles from the WTE plants indicates that the PM{sub 0.1} that penetrates the ECS at WTE can contain high fractions of metals such as Fe, Mn and Cu. The SEM analysis of particles from WTE1-3 showed that the particles were generally porous and irregular in shape. The concentrations of particles in the flue gas from the biomass plants were generally higher than found for the WTE plants. The time series results showed that periodical, high concentration peaks of PM emissions occur from BM1 and BM2. The chemical composition of the particles emitted from the three biomass plants is generally dominated by C, O and S, and to some extend also Fe and Si. A high amount of Cu was found in selected

EPA's Air Quality Rules for Reciprocating Internal Combustion Engines (RICE) and their Application to CHP (Webinar) – June 24, 2014

Science.gov (United States)

This webinar discusses the effect of EPA's air quality regulations on CHP facilities and stationary RICE, and describes how CHP systems can comply with air quality regulations by using stationary RICE.

Optimal Resources Planning of Residential Complex Energy System in a Day-ahead Market Based on Invasive Weed Optimization Algorithm

Directory of Open Access Journals (Sweden)

P. Αhmadi

2017-10-01

Full Text Available This paper deals with optimal resources planning in a residential complex energy system, including FC (fuel cell, PV (Photovoltaic panels and the battery. A day-ahead energy management system (EMS based on invasive weed optimization (IWO algorithm is defined for managing different resources to determine an optimal operation schedule for the energy resources at each time interval to minimize the operation cost of a smart residential complex energy system. Moreover, in this paper the impacts of the sell to grid and purchase from grid are also considered. All practical constraints of the each energy resources and utility policies are taken into account. Moreover, sensitivity analysis are conducted on electricity prices and sell to grid factor (SGF, in order to improve understanding the impact of key parameters on residential CHP systems economy. It is shown that proposed system can meet all electrical and thermal demands with economic point of view. Also enhancement of electricity price leads to substantial growth in utilization of proposed CHP system.

An Integrated and Optimal Joint Scheduling of Energy Resources to Feed Electrical, Thermal and Potable Water Demands in Remote Area

Directory of Open Access Journals (Sweden)

R. Ghaffarpour

2016-12-01

Full Text Available The continuous spread of distributed energy resources (DERs such as combined heating and power (CHP, diesel generators, boilers and renewable energy sources provide an effective solution to energy related problems to serve the power and heat demands with minimum cost. Moreover, the DERs may play a significant role for supplying power and heat in rural areas, where grid electricity is not available. Also, some dry areas may face water scarcity and salinity problems. So, one important solution is the use of DERs to drive desalination units in order to solve water scarcity and salinity problems. In this study, the optimal scheduling of DERs and reverse osmosis (RO desalination unit that feed the required electric, thermal and potable water demands are determined. The present paper describes the operation constraints and cost function of components of the system in detail. Operation constraints of generation units as well as feasible region of operation CHP in dual dependency characteristic are taken into account. To confirm the performance of the proposed model the approach is tested on a realistic remote area over a 24-h period. The results show that the economical scheduling of DERs and desalination units can be obtained using proposed methodology by implementing the proposed formulation.

Exergoeconomic performance optimization of an endoreversible intercooled regenerative Brayton combined heat and power plant coupled to variable-temperature heat reservoirs

Energy Technology Data Exchange (ETDEWEB)

Yang, Bo; Chen, Lingen; Sun, Fengrui [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

2012-07-01

An endoreversible intercooled regenerative Brayton combined heat and power (CHP) plant model coupled to variable-temperature heat reservoirs is established. The exergoeconomic performance of the CHP plant is investigated using finite time thermodynamics. The analytical formulae about dimensionless profit rate and exergy efficiency of the CHP plant with the heat resistance losses in the hot-, cold- and consumer-side heat exchangers, the intercooler and the regenerator are deduced. By taking the maximum profit rate as the objective, the heat conductance allocation among the five heat exchangers and the choice of intercooling pressure ratio are optimized by numerical examples, the characteristic of the optimal dimensionless profit rate versus corresponding exergy efficiency is investigated. When the optimization is performed further with respect to the total pressure ratio, a double-maximum profit rate is obtained. The effects of the design parameters on the double-maximum dimensionless profit rate and corresponding exergy efficiency, optimal total pressure ratio and optimal intercooling pressure ratio are analyzed in detail, and it is found that there exist an optimal consumer-side temperature and an optimal thermal capacitance rate matching between the working fluid and the heat reservoir, respectively, corresponding to a thrice-maximum dimensionless profit rate.

Reducing the network load and optimization of the economic efficiency of CHP plants by forecast-guided control; Verringerung der Netzbelastung und Optimierung der Wirtschaftlichkeit von KWK-Anlagen durch prognosegefuehrte Steuerung

Energy Technology Data Exchange (ETDEWEB)

Glaser, Daniel; Adelhardt, Stefan [Erlangen-Nuernberg Univ., Erlangen (Germany). Lehrstuhl fuer Sensorik; beECO GmbH, Erlangen (Germany)

2012-07-01

Heat-guided combined heat and power (CHP) plants often cause large compensation energy amounts, additional costs to the operator respectively and another burden on the parent network. The balance energy is caused by errors in the production forecast whose quality heavily depends on the heat load performance. This paper identifies the forecasting problems with heat-guided CHP and reveals how the accompanying cost and the network burden can be reduced. This is achieved by an improvement of the forecast in conjunction with a forecast-guided control without affecting the heat supply. In addition, an outlook on further measures to the earnings with the system is presented. (orig.)

Topology optimization of inertia driven dosing units

DEFF Research Database (Denmark)

Andreasen, Casper Schousboe

2017-01-01

This paper presents a methodology for optimizing inertia driven dosing units, sometimes referred to as eductors, for use in small scale flow applications. The unit is assumed to operate at low to moderate Reynolds numbers and under steady state conditions. By applying topology optimization...

Financing CHP Projects at Wastewater Treatment Facilities with Clean Water State Revolving Funds

Science.gov (United States)

This factsheet provides information about CHP at wastewater treatment facilities, including applications, financial challenges, and financial opportunities, such as the Clean Water State Revolving Fund.

Optimally Locating MARFORRES Units

OpenAIRE

Salmeron, Javier; Dell, Rob

2015-01-01

Javier Salmeron and Rob Dell The U.S. Marine Forces Reserve (USMCR, MARFORRES) is conducting realignment studies where discretionary changes may benefit from formal mathematical analysis. This study has developed an optimization tool to guide and/or support Commander, MARFORRES (CMFR) decisions. A prototype of the optimization tool has been tested with data from the units and Reserve Training Centers (RTCs) in the San Francisco, CA and Sacramento, CA areas. Prepared for: MARFORRES, POC:...

The effectiveness of heat pumps as part of CCGT-190/220 Tyumen CHP-1

Directory of Open Access Journals (Sweden)

Tretyakova Polina

2017-01-01

Full Text Available The article considers the possibility of increasing the energy efficiency of CCGT-190/220 Tyumen CHP-1 due to the utilization of low-grade heat given off in the condenser unit of the steam turbine. To assess the effectiveness of the proposed system, the indexes of thermal efficiency are given. As a result of a research the following conclusions are received: The heat-transfer agent heat pump, when heated uses low-grade heat TPP and increases heat output, but consumes the electricity. Using a heat pump is effective for a small temperature difference between the condenser and the evaporator. Good example is heating water before chemical treatment. This method is more efficient than using a replacement boiler and it is used in steam selection.

Flue gas condensation in straw fired CHP plants; Roeggaskondensation i halmfyrede kraftvarmeanlaeg

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-06-15

The high price of straw and a general demand for increased use of straw in power and heat production are expected to result in an increased need for efficient fuel utilization. The use of flue gas condensation in straw fired CHP plants can contribute to a higher exploitation of energy, and at the same time open of the possibility of utilization of wet (cheaper) fuels without energy loss. Furthermore flue gas condensation can contribute to the flue gas cleaning process through removal of HCl and SO{sub 2} as well as in particle cleaning in wet cleaning processes. With starting point in a straw fired CHP plant the technical and economic consequences of installation of a flue gas condensation system are investigated. Fuel exploitation and power/heat production distribution is included in the investigation. (BA)

Development of a CHP/DH system for the new town of Parand: An opportunity to mitigate global warming in Middle East

International Nuclear Information System (INIS)

Mostafavi Tehrani, S. Saeed; Saffar-Avval, M.; Mansoori, Z.; Behboodi Kalhori, S.; Abbassi, A.; Dabir, B.; Sharif, M.

2013-01-01

As a result of the worldwide concern about global warming, projects that target reduction of greenhouse gas emissions have gained a lot of interest. The idea of this paper is to recover exhaust hot gases of an existing gas turbine power plant to meet dynamic thermal energy requirements of a residential area (the new town of Parand) situated in the suburb of Tehran, and also use the rest of the heat source potential to feed a steam turbine cycle. In close proximity to this town, there are two GT plants: Parand (954 MW e ) and Rudeshur (790 MW e ). For handling the CHP/STC/DH plant, two methods are considered along with thermal load following operation strategy: maximum power generation (MPG) and minimum fuel consumption (MFC). Then, the alternatives are compared in terms of annual PES, CO 2 abatement and NPV. For the best design from environmental viewpoint (Parand CHP-B), PES, CO 2 abatement and NPV are calculated to be 27.31%, 2.56 million tons and 1491 million dollar, respectively. -- Highlights: • To propose a technical and financial methodology to evaluate CHP/DH projects. • To address environmental advantages of CHPs with conventional plants. • To present practical operation strategies to increase benefits of CHP/DH plants. • To report/compare benefits of various CHP/DH alternatives for a case study in Iran. • To conduct a comprehensive energy analysis of proposed CHP/DH design options

TaCHP: a wheat zinc finger protein gene down-regulated by abscisic acid and salinity stress plays a positive role in stress tolerance.

Science.gov (United States)

Li, Cuiling; Lv, Jian; Zhao, Xin; Ai, Xinghui; Zhu, Xinlei; Wang, Mengcheng; Zhao, Shuangyi; Xia, Guangmin

2010-09-01

The plant response to abiotic stresses involves both abscisic acid (ABA)-dependent and ABA-independent signaling pathways. Here we describe TaCHP, a CHP-rich (for cysteine, histidine, and proline rich) zinc finger protein family gene extracted from bread wheat (Triticum aestivum), is differentially expressed during abiotic stress between the salinity-sensitive cultivar Jinan 177 and its tolerant somatic hybrid introgression cultivar Shanrong No.3. TaCHP expressed in the roots of seedlings at the three-leaf stage, and the transcript localized within the cells of the root tip cortex and meristem. TaCHP transcript abundance was higher in Shanrong No.3 than in Jinan 177, but was reduced by the imposition of salinity or drought stress, as well as by the exogenous supply of ABA. When JN17, a salinity hypersensitive wheat cultivar, was engineered to overexpress TaCHP, its performance in the face of salinity stress was improved, and the ectopic expression of TaCHP in Arabidopsis (Arabidopsis thaliana) also improved the ability of salt tolerance. The expression level of a number of stress reporter genes (AtCBF3, AtDREB2A, AtABI2, and AtABI1) was raised in the transgenic lines in the presence of salinity stress, while that of AtMYB15, AtABA2, and AtAAO3 was reduced in its absence. The presence in the upstream region of the TaCHP open reading frame of the cis-elements ABRE, MYBRS, and MYCRS suggests that it is a component of the ABA-dependent and -independent signaling pathways involved in the plant response to abiotic stress. We suggest that TaCHP enhances stress tolerance via the promotion of CBF3 and DREB2A expression.

Emissions from decentralised CHP plants 2007 - Energinet.dk Environmental project no. 07/1882. Project report 5 - Emission factors and emission inventory for decentralised CHP production

Energy Technology Data Exchange (ETDEWEB)

Nielsen, Malene; Nielsen, Ole-Kenneth; Thomsen, M.

2010-06-15

Updated emission factors for decentralised combined heat and power (CHP) plants with a capacity < 25MWe have been estimated based on project emission measurements as well as emission measurements performed in recent years that were collected. The emission factors valid for 2006/2007 have been estimated for the plant technologies: Municipal solid waste (MSW) incineration plants, plants combusting straw or wood, natural gas fuelled reciprocating engines, biogas fuelled engines, natural gas fuelled gas turbines, gas oil fuelled reciprocating engines, gas oil fuelled gas turbines, steam turbines combusting residual oil and reciprocating engines combusting biomass producer gas based on wood. The emission factors for MSW incineration plants are much lower than the emission factors that were estimated for year 2000. The considerable reduction in the emission factors is a result of lower emission limit values in Danish legislation since 2006 that has lead to installation of new and improved flue gas cleaning systems in most MSW incineration plants. For CHP plants combusting wood or straw no major technical improvements have been implemented. The emission factors for natural gas fuelled reciprocating engines have been reduced since year 2000 as a result of technical improvements that have been carried out due to lower emission limit values in Danish legislation. The NO{sub x} emission factor for natural gas fuelled gas turbines has decreased 62 % since year 2000. This is a result of installation of low-NO{sub x} burners in almost all gas turbines that has been necessary to meet new emission limits in Danish legislation. The emission measurements programme included screening of the emissions of HCB, PCB, PCDD/-F and PBDD/-F. Compared to the Danish national emission decentralized CHP plants are major emission sources for CH{sub 4}, NO{sub x}, SO{sub 2}, heavy metals and HCB. (author)

Economic feasibility of CHP facilities fueled by biomass from unused agriculture land

DEFF Research Database (Denmark)

Pfeifer, Antun; Dominkovic, Dominik Franjo; Ćosić, Boris

2016-01-01

In this paper, the energy potential of biomass from growing short rotation coppice on unused agricultural land in the Republic of Croatia is used to investigate the feasibility of Combined Heat and Power (CHP) facilities fueled by such biomass. Large areas of agricultural land that remain unused...... work and is now used to investigate the conditions in which such energy facilities could be feasible. The overall potential of biomass from short rotation coppice cultivated on unused agricultural land in the scenarios with 30% of the area is up to 10PJ/year. The added value of fruit trees pruning...... biomass represents an incentive for the development of fruit production on such agricultural land. Sensitivity analysis was conducted for several parameters: cost of biomass, investment costs in CHP systems and combined change in biomass and technology cost....

Putney Basketville Site Biomass CHP Analysis

Energy Technology Data Exchange (ETDEWEB)

Hunsberger, Randolph [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mosey, Gail [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-10-01

The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response Center for Program Analysis developed the RE-Powering America's Land initiative to reuse contaminated sites for renewable energy generation when aligned with the community's vision for the site. The Putney, Vermont, Basketville site, formerly the location of a basket-making facility and a paper mill andwoolen mill, was selected for a feasibility study under the program. Biomass was chosen as the renewable energy resource based on abundant woody-biomass resources available in the area. Biomass combined heat and power (CHP) was selected as the technology due to nearby loads, including Putney Paper and Landmark College.

Operational Strategies for a Portfolio of Wind Farms and CHP Plants in a Two-Price Balancing Market

DEFF Research Database (Denmark)

Hellmers, Anna; Zugno, Marco; Skajaa, Anders

2015-01-01

In this paper we explore the portfolio effect of a system consisting of a Combined Heat and Power (CHP) plant and a wind farm. The goal is to increase the overall profit of the portfolio by reducing imbalances, and consequently their implicit penalty in a two-price balancing market for electricity......-horizon fashion, so that forecasts for heat demand, wind power production and market prices are updated at each iteration. We conclude that the portfolio strategy is the most profitable due to the two-price structure of the balancing market. This encourages producers to handle their imbalances outside the market........ We investigate two different operational strategies, which differ in whether the CHP plant and the wind farm are operated jointly or independently, and we evaluate their economic performance on a real case study based on a CHP-wind system located in the western part of Denmark. We present...

Calorimetric studies and lessons on fires and explosions of a chemical plant producing CHP and DCPO

International Nuclear Information System (INIS)

Hsu, Jing-Ming; Su, Mao-Sheng; Huang, Chiao-Ying; Duh, Yih-Shing

2012-01-01

Highlights: ► We analyzed fire and explosion incidents in a plant producing CHP and DCPO. ► Data from calorimeters reveal causes and phenomena associated with the incidents. ► The credible worst scenario was thermal explosion. ► Incidents may be avoided by implementing DIERS methodology. - Abstract: Cumene hydroperoxide (CHP) has been used in producing phenol, dicumyl peroxide (DCPO) and as an initiator for synthesizing acrylonitrile–butadiene–styrene (ABS) resin by copolymerization in Taiwan. Four incidents of fire and explosion induced by thermal runaway reactions were occurred in a same plant producing CHP, DCPO and bis-(tert-butylperoxy isopropyl) benzene peroxide (BIBP). The fourth fire and explosion occurred in the CHP reactor that resulted in a catastrophic damage in reaction region and even spread throughout storage area. Descriptions on the occurrences of these incidents were assessed by the features of processes, reaction schemes and unexpected side reactions. Calorimetric data on thermokinetics and pressure were used for explaining the practical consequences or which the worst cases encountered in this kind of plant. Acceptable risk associated with emergency relief system design is vital for a plant producing organic peroxide. These basic data for designing an inherently safer plant can be conducted from adiabatic calorimetry. An encouraging deduction has been drawn here, these incidents may be avoided by the implementation of API RP 520, API RP 521, DIERS technology, OSHA 1910.119 and AIChE's CCPS recommended PSM elements.

Process Intensification in Fuel Cell CHP Systems, the ReforCELL Project

Directory of Open Access Journals (Sweden)

José Luis Viviente

2016-10-01

Full Text Available This paper reports the findings of a FP7/FCH JU project (ReforCELL that developed materials (catalysts and membranes and an advance autothermal membrane reformer for a micro Combined Heat and Power (CHP system of 5 kWel based on a polymer electrolyte membrane fuel cell (PEMFC. In this project, an active, stable and selective catalyst was developed for the reactions of interest and its production was scaled up to kg scale (TRL5 (TRL: Technology Readiness Level. Simultaneously, new membranes for gas separation were developed. In particular, dense supported thin palladium-based membranes were developed for hydrogen separation from reactive mixtures. These membranes were successfully scaled up to TRL4 and used in lab-scale reactors for fluidized bed steam methane reforming (SMR and autothermal reforming (ATR and in a prototype reactor for ATR. Suitable sealing techniques able to integrate the different membranes in lab-scale and prototype reactors were also developed. The project also addressed the design and optimization of the subcomponents (BoP for the integration of the membrane reformer to the fuel cell system.

Innovative Hybrid CHP systems for high temperature heating plant in existing buildings

NARCIS (Netherlands)

de Santoli, Livio; Lo Basso, Gianluigi; Nastasi, B.; d’Ambrosio Alfano, Francesca R.; Mazzarella and Piercarlo, Livio

2017-01-01

This paper deals with the potential role of new hybrid CHP systems application providing both electricity and heat which are compatible with the building architectural and landscape limitations. In detail, three different plant layout options for high temperature heat production along with the

Preliminary experimental investigation of a natural gas-fired ORC-based micro-CHP system for residential buildings

International Nuclear Information System (INIS)

Farrokhi, M.; Noie, S.H.; Akbarzadeh, A.A.

2014-01-01

The continual increases in energy demand and greenhouse gas emissions, call for efficient use of energy resources. Decentralized combined heat and power (CHP) technology provides an alternative for the world to meet and solve energy-related problems including energy shortages, energy supply security, emission control and conservation of energy. This paper presents the preliminary results of an experimental investigation of a natural gas-fired micro-CHP system for residential buildings based on an organic Rankine cycle (ORC). Isopentane was used as the ORC working fluid in consideration of several criteria including its environmentally-friendly characteristics. Experiments were conducted to evaluate the performance of the developed system at different heat source temperatures of nominally 85, 80, 75, 70, and 65 °C. The maximum electrical power output of 77.4 W was generated at heating water entry temperature of 84.1 °C, corresponding to net cycle electrical efficiency of 1.66%. Further work will be done with a view to increasing the cycle electrical efficiency by using more efficient components, in particular the expander and generator. - Highlights: •A natural gas-fired ORC-based micro-scale CHP system has been developed and tested. •The good agreement between the mechanical and gross power validates the assumptions. •A vane expander suits a micro-CHP system based on an organic Rankine cycle. •A vane expander does not suit power generation by a Trilateral Flash Cycle (TFC). •Domestic gas-fired ORC systems may reduce reliance on central power stations

Calorimetric studies and lessons on fires and explosions of a chemical plant producing CHP and DCPO

Energy Technology Data Exchange (ETDEWEB)

Hsu, Jing-Ming; Su, Mao-Sheng; Huang, Chiao-Ying [Department of Occupational Safety and Health, Chia Nan University of Pharmacy and Science, Tainan, Taiwan, ROC (China); Duh, Yih-Shing, E-mail: yihshingduh@yahoo.com.tw [Department of Safety, Health and Environmental Engineering, National United University, No. 1 Lien-Da, Miaoli, Taiwan, ROC (China)

2012-05-30

Highlights: Black-Right-Pointing-Pointer We analyzed fire and explosion incidents in a plant producing CHP and DCPO. Black-Right-Pointing-Pointer Data from calorimeters reveal causes and phenomena associated with the incidents. Black-Right-Pointing-Pointer The credible worst scenario was thermal explosion. Black-Right-Pointing-Pointer Incidents may be avoided by implementing DIERS methodology. - Abstract: Cumene hydroperoxide (CHP) has been used in producing phenol, dicumyl peroxide (DCPO) and as an initiator for synthesizing acrylonitrile-butadiene-styrene (ABS) resin by copolymerization in Taiwan. Four incidents of fire and explosion induced by thermal runaway reactions were occurred in a same plant producing CHP, DCPO and bis-(tert-butylperoxy isopropyl) benzene peroxide (BIBP). The fourth fire and explosion occurred in the CHP reactor that resulted in a catastrophic damage in reaction region and even spread throughout storage area. Descriptions on the occurrences of these incidents were assessed by the features of processes, reaction schemes and unexpected side reactions. Calorimetric data on thermokinetics and pressure were used for explaining the practical consequences or which the worst cases encountered in this kind of plant. Acceptable risk associated with emergency relief system design is vital for a plant producing organic peroxide. These basic data for designing an inherently safer plant can be conducted from adiabatic calorimetry. An encouraging deduction has been drawn here, these incidents may be avoided by the implementation of API RP 520, API RP 521, DIERS technology, OSHA 1910.119 and AIChE's CCPS recommended PSM elements.

Simulation and optimization of an industrial PSA unit

Directory of Open Access Journals (Sweden)

Barg C.

2000-01-01

Full Text Available The Pressure Swing Adsorption (PSA units have been used as a low cost alternative to the usual gas separation processes. Its largest commercial application is for hydrogen purification systems. Several studies have been made about the simulation of pressure swing adsorption units, but there are only few reports on the optimization of such processes. The objective of this study is to simulate and optimize an industrial PSA unit for hydrogen purification. This unit consists of six beds, each of them have three layers of different kinds of adsorbents. The main impurities are methane, carbon monoxide and sulfidric gas. The product stream has 99.99% purity in hydrogen, and the recovery is around 90%. A mathematical model for a commercial PSA unit is developed. The cycle time and the pressure swing steps are optimized. All the features concerning with complex commercial processes are considered.

Energy policy responses to the climate change challenge: The consistency of European CHP, renewables and energy efficiency policies

International Nuclear Information System (INIS)

Grohnheit, P.E.

1999-09-01

This report is Volume 14 of individual reports of the Shared Analysis Project prepared for the European Commission, Directorate General for Energy. The three major objectives of the project were: to design a common framework of energy analysis that aimed to involve all Member States and the experts of industrial research groups (the shared approach to energy analysis); To analyse generic EU-wide issues important for energy policy and for future energy demand and production, putting particular emphasis on world energy market trends, strategic energy policy responses to the Kyoto process, and evaluation of response strategies to increasing energy import dependence and to climate change activities; to carry out quantitative analyses of energy trends and scenarios as an input for discussion. The present volume considers three main issues concerning energy policy responses to the climate change challenge: the penetration of CHP and renewables according to official objectives, focusing on infrastructure and institutions rather than technology; the consistency of promotion of CHP, renewables and energy savings at the same time; consumers' choices and priorities in a liberalised market. The volume describes examples of policies in several Member States for these technologies with emphasis on CHP for both large-scale and small-scale district heating systems. The penetration of CHP technologies is analysed quantitatively using a traditional optimisation model approach for stylised regions with heat markets suitable for CHP and facing a competitive European market for electricity. The Joint Final Report of the project, titled 'Economic Foundations for Energy Policy' is published as a Special Issue of Energy in Europe, December 1999. All reports are available on the Internet, www.shared-analysis.fhg.de/ The project started in January 1998, involving about 100 months of scientific labour. The project consortium consisted of nine member institutes co-ordinated by the Fraunhofer

Economic feasibility of CHP facilities fueled by biomass from unused agriculture land

DEFF Research Database (Denmark)

Pfeifer, Antun; Dominkovic, Dominik Franjo; Ćosić, Boris

2016-01-01

In this paper, the energy potential of biomass from growing short rotation coppice on unused agricultural land in the Republic of Croatia is used to investigate the feasibility of Combined Heat and Power (CHP) facilities fueled by such biomass. Large areas of agricultural land that remain unused...

Economic potentials of CHP connected to district heat systems in Germany. Implementation of the EU Efficiency Directive

International Nuclear Information System (INIS)

Eikmeier, Bernd

2015-01-01

The EU Efficiency Directive (2012/27/EU) is requiring all member states to carry out an evaluation of the potential for highly efficient CHP and the efficient use of district heating and cooling by December 2015. The German Federal Ministry of Economic Affairs and Energy appointed this task to the Fraunhofer Institute for Manufacturing and Advanced Materials, division for Energy Systems Analysis (formerly Bremer Energie Institut) in conjunction with other partners. The results for the sector district- and communal heating with CHP, sub-sectors private households, trade and services industry, are presented in this article.

EFFICIENCY OF THE USE OF HEAT PUMPS ON THE CHP PLANTS

Directory of Open Access Journals (Sweden)

Juravleov A.A.

2007-04-01

Full Text Available The work is dedicated to the calculus of the efficiency of the use of heat pumps on the CHP plants. There are presented the interdependences between the pay-back period and NPV of heat pump and the price of 1 kWt of thermal power of heat pump and of the tariff of electricity.

Energy Management for Community Energy Network with CHP Based on Cooperative Game

Directory of Open Access Journals (Sweden)

Xiaofeng Liu

2018-04-01

Full Text Available Integrated energy system (IES has received increasing attention in micro grid due to the high energy efficiency and low emission of carbon dioxide. Based on the technology of combined heat and power (CHP, this paper develops a novel operation mechanism with community micro turbine and shared energy storage system (ESS for energy management of prosumers. In the proposed framework, micro-grid operator (MGO equipped with micro turbine and ESS provides energy selling business and ESS leasing business for prosumers. Prosumers can make energy trading with public grid and MGO, and ESS will be shared among prosumers when they pay for the rent to MGO. Based on such framework, we adopt a cooperative game for prosumers to determine optimal energy trading strategies from MGO and public grid for the next day. Concretely, a cooperative game model is formulated to search the optimal strategies aiming at minimizing the daily cost of coalition, and then a bilateral Shapley value (BSV is proposed to solve the allocation problem of coalition’s cost among prosumers. To verify the effectiveness of proposed energy management framework, a practical example is conducted with a community energy network containing MGO and 10 residential buildings. Simulation results show that the proposed scheme is able to provide financial benefits to all prosumers, while providing peak load leveling for the grid.

Energetic and exergetic efficiencies of coal-fired CHP (combined heat and power) plants used in district heating systems of China

International Nuclear Information System (INIS)

Liao, Chunhui; Ertesvåg, Ivar S.; Zhao, Jianing

2013-01-01

The efficiencies of coal-fired CHP (combined heat and power) plants used in the district heating systems of China were analyzed with a thermodynamic model in the Hysys program. The influences of four parameters were evaluated by the Taguchi method. The results indicated that the extraction steam flow rate and extraction steam pressure are the most important parameters for energetic and exergetic efficiencies, respectively. The relations between extraction steam flow rate, extraction steam pressure and the energetic and exergetic efficiencies were investigated. The energetic and exergetic efficiencies were compared to the RPES (relative primary energy savings) and the RAI (relative avoided irreversibility). Compared to SHP (separate heat and power) generation, the CHP systems save fuel energy when extraction ratio is larger than 0.15. In the analysis of RAI, the minimum extraction ratio at which CHP system has advantages compared with SHP varies between 0.25 and 0.6. The higher extraction pressure corresponds to a higher value. Two of the examined plants had design conditions giving RPES close to zero and negative RAI. The third had both positive RPES and RAI at design conditions. The minimum extraction ratio can be used as an indicator to design or choose CHP plant for a given district heating system. - Highlights: • Extraction flow rate and extraction pressure are the most important parameters. • The exergetic efficiency depends on the energy to exergy ratio and system boundary. • The minimum extraction ratio is a key indicator for CHP plants. • Program Hysys and Taguchi method are used in this research

Stochastic Multicriteria Acceptability Analysis for Evaluation of Combined Heat and Power Units

Directory of Open Access Journals (Sweden)

Haichao Wang

2014-12-01

Full Text Available Combined heat and power (CHP is a promising technology that can contribute to energy efficiency and environmental protection. More CHP-based energy systems are planned for the future. This makes the evaluation and selection of CHP systems very important. In this paper, 16 CHP units representing different technologies are taken into account for multicriteria evaluation with respect to the end users’ requirements. These CHP technologies cover a wide range of power outputs and fuel types. They are evaluated from the energy, economy and environment (3E points of view, specifically including the criteria of efficiency, investment cost, electricity cost, heat cost, CO2 production and footprint. Uncertainties and imprecision are common both in criteria measurements and weights, therefore the stochastic multicriteria acceptability analysis (SMAA model is used in aiding this decision making problem. These uncertainties are treated better using a probability distribution function and Monte Carlo simulation in the model. Moreover, the idea of “feasible weight space (FWS” which represents the union of all preference information from decision makers (DMs is proposed. A complementary judgment matrix (CJM is introduced to determine the FWS. It can be found that the idea of FWS plus CJM is well compatible with SMAA and thus make the evaluation reliable.

Heading towards the nZEB through CHP+HP systems. A comparison between retrofit solutions able to increase the energy performance for the heating and domestic hot water production in residential buildings

International Nuclear Information System (INIS)

Salata, Ferdinando; Golasi, Iacopo; Domestico, Umberto; Banditelli, Matteo; Lo Basso, Gianluigi; Nastasi, Benedetto; Lieto Vollaro, Andrea de

2017-01-01

Highlights: • Energy optimization measures to increase the energy class of buildings. • Analysis of the demands related to the space-heating season and the production of annual DHW. • Case study related to a residential building of medium size located in Rome (Italy). • Improvements on building envelope and on systems (traditional technologies or CHP+HP). • Energy and economic analysis to achieve the performance of a nZEB. - Abstract: Optimizing consumptions in the field of civil construction led to define energy labels for residential buildings. To calculate the building energy demand the EPgl was determined, i.e. the annual consumption per m"2 of primary energy. This paper examines the technical solutions useful to optimize the energy demands for heating during space-heating season and domestic hot water production (thanks to energy analysis softwares as MC11300 and TRNSYS) and, at the same time, to take into account the financial issues those interventions implied. The total inside heated surface of the building case study is 1204.00 m"2, hence the inside heated volume is about 3250.80 m"3. Besides the more traditional interventions concerning the building envelope and its systems, the paper examined the performance of a system obtained through the combination of a cogenerator (CHP) and a heat pump (HP), thus, substituting the conventional boilers of the buildings. CHP+HP solution increases the most the energy label of the building (from a D class with EPgl = 59.62 kW h m"−"2 year"−"1, to an A class, with EPgl = 25.64 kW h m"−"2 year"−"1), determining an annual energy cost saving of 3,114 € year"−"1, allowing to amortize installation costs (54,560 €) in a reasonable payback period, i.e. 15.4 years. This innovative solution in the residential sector can be realized through retrofit interventions on existing buildings, hence it leads the current dwelling towards nZEB with a remarkable benefits for the environment.

Energy policy responses to the climate change challenge: The consistency of European CHP, renewables and energy efficiency policies

Energy Technology Data Exchange (ETDEWEB)

Grohnheit, P.E.

1999-09-01

This report is Volume 14 of individual reports of the Shared Analysis Project prepared for the European Commission, Directorate General for Energy. The three major objectives of the project were: to design a common framework of energy analysis that aimed to involve all Member States and the experts of industrial research groups (the shared approach to energy analysis); To analyse generic EU-wide issues important for energy policy and for future energy demand and production, putting particular emphasis on world energy market trends, strategic energy policy responses to the Kyoto process, and evaluation of response strategies to increasing energy import dependence and to climate change activities; to carry out quantitative analyses of energy trends and scenarios as an input for discussion. The present volume considers three main issues concerning energy policy responses to the climate change challenge: the penetration of CHP and renewables according to official objectives, focusing on infrastructure and institutions rather than technology; the consistency of promotion of CHP, renewables and energy savings at the same time; consumers' choices and priorities in a liberalised market. The volume describes examples of policies in several Member States for these technologies with emphasis on CHP for both large-scale and small-scale district heating systems. The penetration of CHP technologies is analysed quantitatively using a traditional optimisation model approach for stylised regions with heat markets suitable for CHP and facing a competitive European market for electricity. The Joint Final Report of the project, titled 'Economic Foundations for Energy Policy' is published as a Special Issue of Energy in Europe, December 1999. All reports are available on the Internet, www.shared-analysis.fhg.de/ The project started in January 1998, involving about 100 months of scientific labour. The project consortium consisted of nine member institutes co-ordinated by

Optimization of an experimental hybrid microgrid operation: reliability and economic issues

OpenAIRE

Milo, Aitor; Gaztañaga, Haizea; Etxeberria Otadui, Ion; Bilbao, Endika; Rodríguez Cortés, Pedro

2009-01-01

In this paper a hybrid microgrid system, composed of RES (Renewable Energy System) and CHP (Combined Heat and Power) systems together with a battery based storage system is presented. The microgrid is accompanied by a centralized energy management system (CEMS) in order to optimize the microgrid operation both in grid-connected and in stand-alone modes. In grid-connected mode the optimization of the economic exploitation of the microgrid is privileged by applying optim...

A MATHEMATICAL MODEL OF CHP 2000 TYPE PROGRESSIVE GEAR

Directory of Open Access Journals (Sweden)

Paweł Lonkwic

2016-12-01

Full Text Available The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with the loading capacity from 8500 up to 20000 N.

Dynamic optimization of a FCC converter unit: numerical analysis

Directory of Open Access Journals (Sweden)

E. Almeida Nt

2011-03-01

Full Text Available Fluidized-bed Catalytic Cracking (FCC is a process subject to frequent variations in the operating conditions (including feed quality and feed rate. The production objectives usually are the maximization of LPG and gasoline production. This fact makes the FCC converter unit an excellent opportunity for real-time optimization. The present work aims to apply a dynamic optimization in an industrial FCC converter unit, using a mechanistic dynamic model, and to carry out a numerical analysis of the solution procedure. A simultaneous approach was used to discretize the system of differential-algebraic equations and the resulting large-scale NLP problem was solved using the IPOPT solver. This study also does a short comparison between the results obtained by a potential dynamic real-time optimization (DRTO against a possible steady-state real-time optimization (RTO application. The results demonstrate that the application of dynamic real-time optimization of a FCC converter unit can bring significant benefits in production.

Economic feasibility of CHP facilities fueled by biomass from unused agriculture land: Case of Croatia

International Nuclear Information System (INIS)

Pfeifer, Antun; Dominković, Dominik Franjo; Ćosić, Boris; Duić, Neven

2016-01-01

Highlights: • Potential of unused agricultural land for biomass and fruit production is assessed. • Technical and energy potential of biomass from SRC and fruit pruning is calculated. • Economic feasibility of CHP plants utilizing biomass from SRC is presented for Croatia. • Sensitivity analysis and recommendations for shift toward feasibility are provided. - Abstract: In this paper, the energy potential of biomass from growing short rotation coppice on unused agricultural land in the Republic of Croatia is used to investigate the feasibility of Combined Heat and Power (CHP) facilities fueled by such biomass. Large areas of agricultural land that remain unused for food crops, represent significant potential for growing biomass that could be used for energy. This biomass could be used to supply power plants of up to 15 MW_e in accordance with heat demands of the chosen locations. The methodology for regional energy potential assessment was elaborated in previous work and is now used to investigate the conditions in which such energy facilities could be feasible. The overall potential of biomass from short rotation coppice cultivated on unused agricultural land in the scenarios with 30% of the area is up to 10 PJ/year. The added value of fruit trees pruning biomass represents an incentive for the development of fruit production on such agricultural land. Sensitivity analysis was conducted for several parameters: cost of biomass, investment costs in CHP systems and combined change in biomass and technology cost.

Spatial distribution of pollutants in the area of the former CHP plant

Science.gov (United States)

Cichowicz, Robert

2018-01-01

The quality of atmospheric air and level of its pollution are now one of the most important issues connected with life on Earth. The frequent nuisance and exceedance of pollution standards often described in the media are generated by both low emission sources and mobile sources. Also local organized energy emission sources such as local boiler houses or CHP plants have impact on air pollution. At the same time it is important to remember that the role of local power stations in shaping air pollution immission fields depends on the height of emitters and functioning of waste gas treatment installations. Analysis of air pollution distribution was carried out in 2 series/dates, i.e. 2 and 10 weeks after closure of the CHP plant. In the analysis as a reference point the largest intersection of streets located in the immediate vicinity of the plant was selected, from which virtual circles were drawn every 50 meters, where 31 measuring points were located. As a result, the impact of carbon dioxide, hydrogen sulfide and ammonia levels could be observed and analyzed, depending on the distance from the street intersection.

CHP and Local Governments: Case Studies and EPA’s New Guide (Webinar) – September 30, 2014

Science.gov (United States)

This webinar presents two case studies of CHP development projects undertaken through cooperation between private companies and government entities, and introduces an EPA guide to assist local governments to reduce greenhouse gas (GHG) emissions.

Assessment of the implementation issues for fuel cells in domestic and small scale stationary power generation and CHP applications

Energy Technology Data Exchange (ETDEWEB)

Graham, G.; Cruden, A.; Hart, J.

2002-07-01

This report discusses implementation issues associated with the use of fuel cells in <10 kW domestic, small-scale power generation and combined heat and power (CHP) operations in the UK. The report examines the key issues (fuel cell system standards and certification, fuel infrastructure, commercial issues and competing CHP technologies), before discussing non-technical issues including finance, ownership, import and export configuration, pricing structure, customer acceptability, installation, operation and training of servicing and commissioning personnel. The report goes on to discuss market and technical drivers, grid connection issues and solutions, operations and maintenance. Recommendations for the future are made.

Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units

Directory of Open Access Journals (Sweden)

Kehe Wu

2014-01-01

Full Text Available An optimal capacity allocation of large-scale wind-photovoltaic- (PV- battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net present cost (NPC was calculated through hybrid iteration/adaptive hybrid genetic algorithm (HIAGA. The optimal capacity ratio among wind generator, PV array, and battery device also was calculated simultaneously. A simulation was conducted based on the wind-PV-battery unit in Zhangbei, China. Results showed that a wind-PV-battery unit could effectively minimize the NPC of power-generation units under a stable grid-connected operation. Finally, the sensitivity analysis of the wind-PV-battery unit demonstrated that the optimization result was closely related to potential wind-solar resources and government support. Regions with rich wind resources and a reasonable government energy policy could improve the economic efficiency of their power-generation units.

Optimal design of unit hydrographs using probability distribution and ...

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

optimization formulation is solved using binary-coded genetic algorithms. The number of variables to ... Unit hydrograph; rainfall-runoff; hydrology; genetic algorithms; optimization; probability ..... Application of the model. Data derived from the ...

Research, Development and Demonstration of Micro-CHP Systems for Residential Applications - Phase I

Energy Technology Data Exchange (ETDEWEB)

Robert A. Zogg

2011-03-14

The objective of the Micro-CHP Phase I effort was to develop a conceptual design for a Micro-CHP system including: Defining market potential; Assessing proposed technology; Developing a proof-of-principle design; and Developing a commercialization strategy. TIAX LLC assembled a team to develop a Micro-CHP system that will provide electricity and heating. TIAX, the contractor and major cost-share provider, provided proven expertise in project management, prime-mover design and development, appliance development and commercialization, analysis of residential energy loads, technology assessment, and market analysis. Kohler Company, the manufacturing partner, is a highly regarded manufacturer of standby power systems and other residential products. Kohler provides a compellingly strong brand, along with the capabilities in product development, design, manufacture, distribution, sales, support, service, and marketing that only a manufacturer of Kohler's status can provide. GAMA, an association of appliance and equipment manufacturers, provided a critical understanding of appliance commercialization issues, including regulatory requirements, large-scale market acceptance issues, and commercialization strategies. The Propane Education & Research Council, a cost-share partner, provided cost share and aided in ensuring the fuel flexibility of the conceptual design. Micro-CHP systems being commercialized in Europe and Japan are generally designed to follow the household thermal load, and generate electricity opportunistically. In many cases, any excess electricity can be sold back to the grid (net metering). These products, however, are unlikely to meet the demands of the U.S. market. First, these products generally cannot provide emergency power when grid power is lost--a critical feature to market success in the U.S. Even those that can may have insufficient electric generation capacities to meet emergency needs for many U.S. homes. Second, the extent to which net

In-situ corrosion investigation at Masnedø CHP plant - a straw-fired power plant

DEFF Research Database (Denmark)

Montgomery, Melanie; Karlsson, Asger

1999-01-01

Various austenitic and ferritic steels were exposed on a water-cooled probe in the superheater area of a straw-fired CHP plant. The temperature of the probe ranged from 450-600°C and the period of exposure was 1400 hours. The rate of corrosion was assessed based on unattacked metal remaining...

Identification of an operon, Pil-Chp, that controls twitching motility and virulence in Xylella fastidiosa.

Science.gov (United States)

Cursino, Luciana; Galvani, Cheryl D; Athinuwat, Dusit; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia

2011-10-01

Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.

Feasibility study of a Thermo-Photo-Voltaic system for CHP application in residential buildings

International Nuclear Information System (INIS)

Bianchi, Michele; Ferrari, Claudio; Melino, Francesco; Peretto, Antonio

2012-01-01

Highlights: ► The profitability of Thermo-Photo-Voltaic generator systems for a single-family dwelling is analyzed. ► Heat and electricity load profiles depending on hour of the day are considered for an entire year. ► The effect of Thermo-Photo-Voltaic generator size is evaluated for different household utilities. ► Results allow to identify the conditions for the energetic and economic convenience of Thermo-Photo-Voltaic system. -- Abstract: The growing demand of energy coupled with an increasing attention to the environmental impact have forced, in the last decades, toward the study and the development of new strategies in order to reduce primary energy consumptions. The cogeneration (CHP) and the on-site generation (also known as distributed generation) could be the key strategy to achieve this goal; CHP systems allow to reduce the fuel consumption and pollutant emissions (in particular the greenhouse gases) compared to separate generation; moreover on-site-generation contributes to the reduction of the energy which is lost in electricity transmission, and increases the security in the energy supply. In this scenario the Thermo-Photo-Voltaic generation (TPV) is obtaining an increasing attention; TPV is a system to convert into electrical energy the radiation emitted from an artificial heat source (i.e. the combustion of fuel) by the use of photovoltaic cells. A domestic gas furnace based on this technology can provide the entire thermal need of an apartment and can also contributes to satisfy the electrical demand. The aim of this study is the understanding of the behavior of a TPV in CHP application in case of residential buildings, under both the energetic and economical point of view; in particular a parametrical analysis is developed and discussed varying the TPV electrical efficiency, the thermal request and the apartment typology.

Energy efficiency analysis and impact evaluation of the application of thermoelectric power cycle to today's CHP systems

DEFF Research Database (Denmark)

Chen, Min; Lund, Henrik; Rosendahl, Lasse

2010-01-01

benefits, together with the environmental impact of this deployment, will then be estimated. By using the Danish thermal energy system as a paradigm, this paper will consider the TEG application to district heating systems and power plants through the EnergyPLAN model, which has been created to design......High efficiency thermoelectric generators (TEG) can recover waste heat from both industrial and private sectors. Thus, the development and deployment of TEG may represent one of the main drives for technological change and fuel substitution. This paper will present an analysis of system efficiency...... configurations for combustion systems. The feasible deployment of TEG in various CHP plants will be examined in terms of heat source temperature range, influences on CHP power specification and thermal environment, as well as potential benefits. The overall conversion efficiency improvements and economic...

Optimal operation of cogeneration units. State of art and perspective

International Nuclear Information System (INIS)

Polimeni, S.

2001-01-01

Optimal operation of cogeneration plants and of power plant fueling waste products is a complex challenge as they have to fulfill, beyond the contractual obligation of electric power supply, the constraints of supplying the required thermal energy to the user (for cogeneration units) or to burn completely the by-products of the industrial complex where they are integrated. Electrical power market evolution is pushing such units to a more and more volatile operation caused by uncertain selling price levels. This work intends to pinpoint the state of art in the optimization of these units outlining the important differences among the different size and cycles. The effect of the market liberalization on the automation systems and the optimization algorithms will be discussed [it

A price mechanism for supply demand matching in local grid of households with micro-CHP

NARCIS (Netherlands)

Larsen, G.K.H.; van Foreest, N.D.; Scherpen, J.M.A.

2012-01-01

This paper describes a dynamic price mechanism to coordinate eletric power generation from micro Combined Heat and Power (micro-CHP) systems in a network of households. It is assumed that the households are prosumers, i.e. both producers and consumers of electricity. The control is done on household

Modeling and parametric study of a 1 kWe HT-PEMFC-based residential micro-CHP system

DEFF Research Database (Denmark)

Arsalis, Alexandros; Nielsen, Mads Pagh; Kær, Søren Knudsen

2011-01-01

A detailed thermodynamic, kinetic and geometric model of a micro-CHP (Combined-Heatand-Power) residential system based on High Temperature-Proton Exchange Membrane Fuel Cell (HT-PEMFC) technology is developed, implemented and validated. HT-PEMFC technology is investigated as a possible candidate...

Fuel cell power plants for decentralised CHP applications

International Nuclear Information System (INIS)

Ohmer, Martin; Mattner, Katja

2015-01-01

Fuel cells are the most efficient technology to convert chemical energy into electricity and heat and thus they could have a major impact on reducing fuel consumption, CO 2 and other emissions (NO x , SO x and particulate matter). Fired with natural or biogas and operated with an efficiency of up to 49 % a significant reduction of fuel costs can be achieved in decentralised applications. Combined heat and power (CHP) configurations add value for a wide range of industrial applications. The exhaust heat of approximately 400 C can be utilised for heating purposes and the production of steam. Besides, it can be also fed directly to adsorption cooling systems. With more than 110 fuel cell power plants operating worldwide, this technology is a serious alternative to conventional gas turbines or gas engines.

Systematic optimization of subcritical and transcritical organic Rankine cycles (ORCs) constrained by technical parameters in multiple applications

International Nuclear Information System (INIS)

Maraver, Daniel; Royo, Javier; Lemort, Vincent; Quoilin, Sylvain

2014-01-01

Highlights: • ORC optimization for different target applications. • Model developed to allow computation in subcritical and transcritical operation. • Regenerative and non-regenerative cycles evaluated through second law efficiency. • Common working fluids: R134a, R245fa, Solkatherm, n-Pentane, MDM, Toluene. • Thermodynamic and technological approaches lead to optimal design guidelines. - Abstract: The present work is focused on the thermodynamic optimization of organic Rankine cycles (ORCs) for power generation and CHP from different average heat source profiles (waste heat recovery, thermal oil for cogeneration and geothermal). The general goal is to provide optimization guidelines for a wide range of operating conditions, for subcritical and transcritical, regenerative and non-regenerative cycles. A parameter assessment of the main equipment in the cycle (expander, heat exchangers and feed pump) was also carried out. An optimization model of the ORC (available as an electronic annex) is proposed to predict the best cycle performance (subcritical or transcritical), in terms of its exergy efficiency, with different working fluids. The working fluids considered are those most commonly used in commercial ORC units (R134a, R245fa, Solkatherm, n-Pentane, Octamethyltrisiloxane and Toluene). The optimal working fluid and operating conditions from a purely thermodynamic approach are limited by the technological constraints of the expander, the heat exchangers and the feed pump. Hence, a complementary assessment of both approaches is more adequate to obtain some preliminary design guidelines for ORC units

Micro CHP as a new business model. Trianel distribution system decentralised production; Mikro-BHKW als neues Geschaeftsmodell. Trianel-Netzwerk Dezentrale Erzeugung

Energy Technology Data Exchange (ETDEWEB)

Nicolai, Michel [Trianel GmbH, Aachen (Germany)

2013-04-29

About four years ago, an energy distribution company in Hamburg (Federal Republic of Germany) reported on mini and micro CHP in the media. When it comes to a decentralized production of electricity and heat, however public utilities are the perfect partner: the decentralized power generation in flexible adjustable combined heat and power plants offers the opportunity to provide highly efficient heat and power directly at the place of consumption. In addition, regional and municipal utilities score with the theme mini and micro CHP for their customers due to the support on the way to more energy efficiency.

Optimal unit sizing for small-scale integrated energy systems using multi-objective interval optimization and evidential reasoning approach

International Nuclear Information System (INIS)

Wei, F.; Wu, Q.H.; Jing, Z.X.; Chen, J.J.; Zhou, X.X.

2016-01-01

This paper proposes a comprehensive framework including a multi-objective interval optimization model and evidential reasoning (ER) approach to solve the unit sizing problem of small-scale integrated energy systems, with uncertain wind and solar energies integrated. In the multi-objective interval optimization model, interval variables are introduced to tackle the uncertainties of the optimization problem. Aiming at simultaneously considering the cost and risk of a business investment, the average and deviation of life cycle cost (LCC) of the integrated energy system are formulated. In order to solve the problem, a novel multi-objective optimization algorithm, MGSOACC (multi-objective group search optimizer with adaptive covariance matrix and chaotic search), is developed, employing adaptive covariance matrix to make the search strategy adaptive and applying chaotic search to maintain the diversity of group. Furthermore, ER approach is applied to deal with multiple interests of an investor at the business decision making stage and to determine the final unit sizing solution from the Pareto-optimal solutions. This paper reports on the simulation results obtained using a small-scale direct district heating system (DH) and a small-scale district heating and cooling system (DHC) optimized by the proposed framework. The results demonstrate the superiority of the multi-objective interval optimization model and ER approach in tackling the unit sizing problem of integrated energy systems considering the integration of uncertian wind and solar energies. - Highlights: • Cost and risk of investment in small-scale integrated energy systems are considered. • A multi-objective interval optimization model is presented. • A novel multi-objective optimization algorithm (MGSOACC) is proposed. • The evidential reasoning (ER) approach is used to obtain the final optimal solution. • The MGSOACC and ER can tackle the unit sizing problem efficiently.

A Compound Herbal Preparation (CHP) in the Treatment of Children with ADHD: A Randomized Controlled Trial

Science.gov (United States)

Katz, M.; Adar Levine, A.; Kol-Degani, H.; Kav-Venaki, L.

2010-01-01

Objective: Evaluation of the efficacy of a patented, compound herbal preparation (CHP) in improving attention, cognition, and impulse control in children with ADHD. Method: Design: A randomized, double-blind, placebo-controlled trial. Setting: University-affiliated tertiary medical center. Participants: 120 children newly diagnosed with ADHD,…

Biomass gasification for CHP with dry gas cleaning and regenerative heat recovery

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-05-01

Small scale CHP plants based on biomass gasification technologies are generally expensive and not very efficient due to gas quality problems which increase operation and maintenance cost as well as breakdown. To overcome this situation the team has developed, integrated and tested a complete biomass gasification combine heat and power prototype plant of 250 kWth equipped with a specifically developed dry gas cleaning and heat recovery system. The dry gas cleaning device is a simple dry gas regenerative heat exchanger where tars are stopped by condensation but working at a temperature above due point in order to avoid water condensation. Two types of heat particles separation devices have been tested in parallel multi-cyclone and ceramic filters. After several month spent on modelling design, construction and optimisation, a full test campaign of 400 hours continuous monitoring has been done where all working parameters has been monitored and gas cleaning device performances has been assessed. Results have shown: Inappropriateness of the ceramic filters for the small scale unit due to operation cost and too high sensibility of the filters to the operation conditions fluctuating in a wide range, despite a very high particle separation efficiency 99 %; Rather good efficiency of the multi-cyclone 72% but not sufficient for engine safety. Additional conventional filters where necessary for the finest part; Inappropriateness of the dry gas heat exchanger device for tar removal partly due to a low tar content of the syngas generated, below 100 mg/Nm{sup 3} , but also due to their composition which would have imposed, to be really efficient, a theoretical condensing temperature of 89 C below the water condensation temperature. These results have been confirmed by laboratory tests and modelling. However the tar cracking phase have shown very interesting results and proved the feasibility of thermal cracking with full cleaning of the heat exchanger without further mechanical

Modelling the Italian household sector at the municipal scale: Micro-CHP, renewables and energy efficiency

International Nuclear Information System (INIS)

Comodi, Gabriele; Cioccolanti, Luca; Renzi, Massimiliano

2014-01-01

This study investigates the potential of energy efficiency, renewables, and micro-cogeneration to reduce household consumption in a medium Italian town and analyses the scope for municipal local policies. The study also investigates the effects of tourist flows on town's energy consumption by modelling energy scenarios for permanent and summer homes. Two long-term energy scenarios (to 2030) were modelled using the MarkAL-TIMES generator model: BAU (business as usual), which is the reference scenario, and EHS (exemplary household sector), which involves targets of penetration for renewables and micro-cogeneration. The analysis demonstrated the critical role of end-use energy efficiency in curbing residential consumption. Cogeneration and renewables (PV (photovoltaic) and solar thermal panels) were proven to be valuable solutions to reduce the energetic and environmental burden of the household sector (−20% in 2030). Because most of household energy demand is ascribable to space-heating or hot water production, this study finds that micro-CHP technologies with lower power-to-heat ratios (mainly, Stirling engines and microturbines) show a higher diffusion, as do solar thermal devices. The spread of micro-cogeneration implies a global reduction of primary energy but involves the internalisation of the primary energy, and consequently CO 2 emissions, previously consumed in a centralised power plant within the municipality boundaries. - Highlights: • Energy consumption in permanent homes can be reduced by 20% in 2030. • High efficiency appliances have different effect according to their market penetration. • Use of electrical heat pumps shift consumption from natural gas to electricity. • Micro-CHP entails a global reduction of energy consumption but greater local emissions. • The main CHP technologies entering the residential market are Stirling and μ-turbines

Comparative analysis of organizational obstacles to CHP/DH

Energy Technology Data Exchange (ETDEWEB)

Ruedig, W.

1986-04-01

An explanation is given of the vast differences between the countries of Western Europe in the adoption of combined heat and power (CHP) for district heating (DH). The history of this technology in FR Germany and the UK is analysed in detail, and experiences of other countries are reviewed. It is concluded that the over centralization of the electricity supply industry is a major obstacle in the widespread adoption of combined heat and power and district heating. Significant improvements of energy efficiency would thus require organizational reforms giving greater powers to local energy organizations. This, however, should not imply total decentralization of energy supply. Instead, a two-tier system is proposed in which central organizations remain responsible for bulk supply but where local or regional bodies are in charge of all gas, electricity and heat supplies to the final user.

Advanced m-CHP fuel cell system based on a novel bio-ethanol fluidized bed membrane reformer

NARCIS (Netherlands)

Viviente, J.L.; Melendez Rey, J.; Pacheco Tanaka, D.A.; Gallucci, F.; Spallina, V.; Manzolini, G.; Foresti, S.; Palma, V.; Ruocco, C.; Roses, L.

2017-01-01

Distributed power generation via Micro Combined Heat and Power (m-CHP) systems, has been proven to over-come disadvantages of centralized generation since it can give savings in terms of Primary Energy consumption and energy costs. The FluidCELL FCH JU/FP7 project aims at providing the Proof of

Experimental study and modelling of degradation phenomena in HTPEM fuel cell stacks for use in CHP systems

DEFF Research Database (Denmark)

Andreasen, Søren Juhl

2009-01-01

Degradation phenomena in HTPEM fuel cells for use in CHP systems were investigated experimentally and by modelling. It was found that the two main degradation mechanisms in HTPEM fuel cells are carbon corrosion and Pt agglomeration. On basis of this conclusion a mechanistic model, describing...

The Design, Construction, and Experimental Evaluation of a Compact Thermoacoustic-Stirling Engine Generator for Use in a micro-CHP Appliance

Science.gov (United States)

Wilcox, Douglas A., Jr.

Micro combined heat and power or micro-CHP is the simultaneous generation of useful heat and electricity on a residential scale. The heat and electricity are produced at the point of use, avoiding the distribution losses associated with a centralized power plant. These appliances combine a conventional gas-fired condensing boiler with an electric power module capable of generating electricity from the heat of combustion. Currently, the leading power modules for micro-CHP appliances are free-piston Stirling engines (FPSEs) which can generate 1050 watts of electricity at a thermal-to-electric efficiency of 26%.[1] These external combustion engines have been under development for the last 25 years, with FPSE micro-CHP appliances only recently being introduced to the commercial market. Publications by developers assert unlimited service life and high efficiency, with low noise and emissions; but despite these claims, the actual reliability and cost of manufacturing has prevented their successful mass-market adoption. A Thermoacoustic-Stirling Engine Generator or TaSEG is one possible alternative to FPSE's. A TaSEG uses a thermoacoustic engine, or acoustic heat engine, which can efficiently convert high temperature heat into acoustic power while maintaining a simple design with fewer moving parts than traditional FPSE's. This simpler engine is coupled to an electrodynamic alternator capable of converting acoustic power into electricity. This thesis outlines the design, construction, and experimental evaluation of a TaSEG which is appropriate for integration with a gas burner inside of a residential micro- CHP appliance. The design methodology is discussed, focusing on how changes in the geometry affected the predicted performance. Details of its construction are given and the performance of the TaSEG is then outlined. The TaSEG can deliver 132 watts of electrical output power to an electric load with an overall measured thermal-to-electric (first law) efficiency of eta

Renewables and CHP with District Energy in Support of Sustainable Communities

Energy Technology Data Exchange (ETDEWEB)

Snoek, Chris

2010-09-15

This paper addresses the powerful idea of connecting many energy users to environmentally optimum energy sources through integrated community energy systems. Such systems require piping networks for distributing thermal energy, i.e., district heating and cooling (DHC) systems. The possibilities and advantages of the application of integrated energy concepts are discussed, including the economic and environmental benefits of integrating localized electrical generating systems (CHP), transportation systems, industrial processes and other thermal energy requirements. Examples of a number of operating systems are provided. Some of the R and D carried out by the IEA Implementing Agreement on District Heating and Cooling is also described.

Large-area landslide susceptibility with optimized slope-units

Science.gov (United States)

Alvioli, Massimiliano; Marchesini, Ivan; Reichenbach, Paola; Rossi, Mauro; Ardizzone, Francesca; Fiorucci, Federica; Guzzetti, Fausto

2017-04-01

A Slope-Unit (SU) is a type of morphological terrain unit bounded by drainage and divide lines that maximize the within-unit homogeneity and the between-unit heterogeneity across distinct physical and geographical boundaries [1]. Compared to other terrain subdivisions, SU are morphological terrain unit well related to the natural (i.e., geological, geomorphological, hydrological) processes that shape and characterize natural slopes. This makes SU easily recognizable in the field or in topographic base maps, and well suited for environmental and geomorphological analysis, in particular for landslide susceptibility (LS) modelling. An optimal subdivision of an area into a set of SU depends on multiple factors: size and complexity of the study area, quality and resolution of the available terrain elevation data, purpose of the terrain subdivision, scale and resolution of the phenomena for which SU are delineated. We use the recently developed r.slopeunits software [2,3] for the automatic, parametric delineation of SU within the open source GRASS GIS based on terrain elevation data and a small number of user-defined parameters. The software provides subdivisions consisting of SU with different shapes and sizes, as a function of the input parameters. In this work, we describe a procedure for the optimal selection of the user parameters through the production of a large number of realizations of the LS model. We tested the software and the optimization procedure in a 2,000 km2 area in Umbria, Central Italy. For LS zonation we adopt a logistic regression model implemented in an well-known software [4,5], using about 50 independent variables. To select the optimal SU partition for LS zonation, we want to define a metric which is able to quantify simultaneously: (i) slope-unit internal homogeneity (ii) slope-unit external heterogeneity (iii) landslide susceptibility model performance. To this end, we define a comprehensive objective function S, as the product of three

Emissions from decentralised CHP plants 2007 - Energinet.dk Environmental project no. 07/1882

DEFF Research Database (Denmark)

Nielsen, Malene; Nielsen, Ole-Kenneth; Thomsen, Marianne

Updated emission factors for decentralised combined heat and power (CHP) plants with a capacity project emission measurements as well as emission measurements performed in recent years that were collected. The emission factors valid for 2006/2007 have been...... estimated for the plant technologies: Municipal solid waste (MSW) incineration plants, plants combusting straw or wood, natural gas fuelled reciprocating engines, biogas fuelled engines, natural gas fuelled gas turbines, gas oil fuelled reciprocating engines, gas oil fuelled gas turbines, steam turbines...

Optimal Scheduling of Integrated Energy Systems with Combined Heat and Power Generation, Photovoltaic and Energy Storage Considering Battery Lifetime Loss

Directory of Open Access Journals (Sweden)

Yongli Wang

2018-06-01

Full Text Available Integrated energy systems (IESs are considered a trending solution for the energy crisis and environmental problems. However, the diversity of energy sources and the complexity of the IES have brought challenges to the economic operation of IESs. Aiming at achieving optimal scheduling of components, an IES operation optimization model including photovoltaic, combined heat and power generation system (CHP and battery energy storage is developed in this paper. The goal of the optimization model is to minimize the operation cost under the system constraints. For the optimization process, an optimization principle is conducted, which achieves maximized utilization of photovoltaic by adjusting the controllable units such as energy storage and gas turbine, as well as taking into account the battery lifetime loss. In addition, an integrated energy system project is taken as a research case to validate the effectiveness of the model via the improved differential evolution algorithm (IDEA. The comparison between IDEA and a traditional differential evolution algorithm shows that IDEA could find the optimal solution faster, owing to the double variation differential strategy. The simulation results in three different battery states which show that the battery lifetime loss is an inevitable factor in the optimization model, and the optimized operation cost in 2016 drastically decreased compared with actual operation data.

Analyzing a self-managed CHP system for greenhouse cultivation as a profitable way to reduce CO2-emissions

International Nuclear Information System (INIS)

Compernolle, Tine; Witters, Nele; Van Passel, Steven; Thewys, Theo

2011-01-01

To counter global warming, a transition to a low-carbon economy is needed. The greenhouse sector can contribute by installing Combined Heat and Power (CHP) systems, known for their excellent energy efficiency. Due to the recent European liberalization of the energy market, glass horticulturists have the opportunity to sell excess electricity to the market and by tailored policy and support measures, regional governments can fill the lack of technical and economic knowledge, causing initial resistance. This research investigates the economic and environmental opportunities using two detailed cases applying a self managed cogeneration system. The Net Present Value is calculated to investigate the economic feasibility. The Primary Energy Saving, the CO 2 Emission Reduction indicator and an Emission Balance are applied to quantify the environmental impact. The results demonstrate that a self-managed CHP system is economic viable and that CO 2 emissions are reduced.

Economic optimization of waste treatment and energy production in Denmark

DEFF Research Database (Denmark)

Münster, Marie; Ravn, Hans; Hedegaard, Karsten

2013-01-01

This article presents an optimization model that incorporates LCA methodology and captures important characteristics of waste management systems. The most attractive waste management options are in the model identified as part the optimization. The model renders it possible to apply different...... optimization objectives such as minimizing costs or greenhouse gas emissions or to prioritise several objectives given different weights. An illustrative case is analyzed, covering alternative treatments of 1 tonne residual household waste: incineration of the full amount or sorting out organic waste...... for biogas production for either CHP generation or as fuel in vehicles. The case study illustrates, that what is the optimal solution depends on the objective and assumptions regarding the background system – here illustrated with different assumptions regarding displaced electricity production. The article...

Penempatan Optimal Phasor Measurement Unit (PMU) Dengan Integer Programming

OpenAIRE

Amrulloh, Yunan Helmy

2013-01-01

Phasor Measurement Unit (PMU) merupakan peralatan yang mampu memberikan pengukuran fasor tegangan dan arus secara real-time. PMU dapat digunakan untuk monitoring, proteksi dan kontrol pada sistem tenaga listrik. Tugas akhir ini membahas penempatan PMU secara optimal berdasarkan topologi jaringan sehingga sistem tenaga listrik dapat diobservasi. Penempatan optimal PMU dirumuskan sebagai masalah Binary Integer Programming (BIP) yang akan memberikan variabel dengan pilihan nilai (0,1) yang menu...

Total cost of ownership of CHP SOFC systems: Effect of installation context

International Nuclear Information System (INIS)

Arduino, Francesco; Santarelli, Massimo

2016-01-01

Solid oxide fuel cells (SOFC) are one of the most interesting between the emerging technologies for energy production. Although some information about the production cost of these devices are already known, their operational cost has not been studied yet with sufficient accuracy. This paper presents a life cycle cost (LCC) analysis of CHP (combined heat and power) SOFC systems performed in hospitals located in various cities of the US and one in Italy. In this study the strong effects of the installation context will be analyzed using a customized use phase model for each location. The cost effectiveness of these devices has been proved without credits in Mondovi (IT), New York (NY) and Minneapolis (MN) where the payback time goes from 10 to 7 years. Considering the credits, it is possible to obtain economic feasibility also in Chicago (IL) and reduce the payback for other cities to values from 4 to 6 years. In other cities like Phoenix (AZ) and Houston (TX) the payback can’t be reached in any case. The life cycle impact assessment analysis has shown how, even in the cities with cleaner electricity grid, there is a reduction in the emissions of both greenhouse gases and pollutants. - Highlights: •Life cycle cost analysis has been performed for CHP SOFC systems. •The strong effects of the installation context have been analyzed. •Economic feasibility has been proven in new york, Minneapolis and Mondovi. •Economic feasibility can’t be reached in phoenix and Houston. •SOFC always provide a reduction in the emissions of greenhouse gases and pollutant.

Advice on MEP tariff for cogeneration in 2004

International Nuclear Information System (INIS)

Ten Donkelaar, M.; Harmsen, R.; Scheepers, M.J.J.

2004-05-01

The title analysis is part of the monitoring of combined heat and power generation (CHP) in the Netherlands, and concerns the impact of the new Dutch subsidy scheme MEP (environmental quality of power generation) on the cost-effectiveness of CHP investments based on a number of CHP reference cases. The MEP scheme provides a reward for the additional kWhs of electricity produced by CHP units compared to separate production of heat and power. This means that the MEP rewards the 'CO2 free kWhs' produced by CHP units, providing an incentive for the most efficient CHP units. In the first chapter a description of the calculation of 'CO2 free kWhs' is given followed by the physical developments of CHP in the Netherlands. The third and final chapter calculates the impact of the MEP regulation on the cost effectiveness of CHP and compares it with the European Community Guidelines on Aid for Environmental Protection. The results of the calculations show that the Dutch MEP scheme complies with the European guidelines for all CHP reference cases [nl

Energetic and Exergetic Analysis of a Heat Exchanger Integrated in a Solid Biomass-Fuelled Micro-CHP System with an Ericsson Engine

Directory of Open Access Journals (Sweden)

Marie Creyx

2016-04-01

Full Text Available A specific heat exchanger has been developed to transfer heat from flue gas to the working fluid (hot air of the Ericsson engine of a solid biomass-fuelled micro combined heat and power (CHP. In this paper, the theoretical and experimental energetic analyses of this heat exchanger are compared. The experimental performances are described considering energetic and exergetic parameters, in particular the effectiveness on both hot and cold sides. A new exergetic parameter called the exergetic effectiveness is introduced, which allows a comparison between the real and the ideal heat exchanger considering the Second Law of Thermodynamics. A global analysis of exergetic fluxes in the whole micro-CHP system is presented, showing the repartition of the exergy destruction among the components.

Optimization of a flexible multi-generation system based on wood chip gasification and methanol production

DEFF Research Database (Denmark)

Lythcke-Jørgensen, Christoffer Ernst; Clausen, Lasse Røngaard; Algren, Loui

2017-01-01

of ± 25% in investment costs and methanol price, and considering two different electricity price scenarios.In addition, a change in the interest rate from 5% to 20% was found to reduce the lower bound of the NPVto 181.3 M€ for reference operating conditions. The results suggest that the applied interest...... rate andoperating conditions, in particular the methanol price, would have a much higher impact on the economicperformance of the designs than corresponding uncertainties in investment costs. In addition,the study outcomes emphasize the importance of including systematic uncertainty analysis...... with an existing combined heat and power (CHP) unit and industrial energy utility supply in the Danish city of Horsens. The objective was to optimize economic performance and minimize total CO2 emission of the FMG while it was required to meet the local district heating demand plus the thermal utility demand...

Small-scale CHP Plant based on a 35 kWel Hermetic Four Cylinder Stirling Engine for Biomass Fuels- Development, Technology and Operating Experiences

DEFF Research Database (Denmark)

Obernberger, I.; Carlsen, Henrik; Biedermann, F.

2003-01-01

) process and the Stirling engine process. The ORC process represents an economically interesting technology for small-scale biomass-fired combined heat and power plants in a power range between 400 and 1,500 kWel. A newly developed ORC technology with a nominal electric capacity of 1,000 kW was implemented...... in the biomass CHP plant Lienz (A) in the framework of an EU demonstration project. This plant was put in operation in February 2002. Stirling engines are a promising solution for installations with nominal electric capacities between 10 and 150 kW. A biomass CHP pilot plant based on a 35 kWel-Stirling engine...

Increased electrical efficiency in biofueled CHP plants by biomass drying; Oekat elutbyte i biobraensleeldade kraftvaermeanlaeggningar med hjaelp av foertorkning

Energy Technology Data Exchange (ETDEWEB)

Berntsson, Mikael; Thorson, Ola; Wennberg, Olle

2010-09-15

In this report, integrated biofuel drying has been studied for two cases. One is the existing CHP plant at ENA Energi AB in Enkoeping and the other is a theoretical case. The thought plant is assumed to have a steam generating performance that is probable for a future CHP plant optimised for power production. The CHP plant at ENA Energi with its integrated bed drying system has been used as a model in this study. The plant has a grate fired boiler with the capacity to co-produce 24 MW electricity and 55 MW heat. It is designed to use biofuel with moisture content between 40 and 55 %. However, the boiler is able to manage even dryer fuels with the moisture content of about 35 % without complications. Since the boiler operates on part load during most of the season, there are free capacity which can be used for delivering heat to the drying system. The increased power production is a result of mainly two factors: Increased demand of heat as the dryer uses district heating and thus improved possibility to produce steam; and, The season of operation can be extended, since the point where the minimum load of the boiler occurs can be pushed forward as a result of increased demand of heat. For future CHP plants, an optimised plant has been used as a model. The steam data is assumed to be 170 bar and 540 deg C with reheating. For this plant, both on-site and offsite drying have been studied. The case study comprises a whole season of operation and the fuel is assumed to be dried from 50 to 10 %. The size of the optimised plant is as to fit the dimension of a main production unit in a district heating net equal to the tenth largest in Sweden. Heat delivery is assumed to be 896 GWh/year and the maximum heat delivery of district heating is 250 MW. The sizing of the boiler is made to maximise the production of electricity, and thus dependent of the drying strategy used. Flue gas condensation is assumed to be used as much as possible. It decreases the basis for power production

A CSP plant combined with biomass CHP using ORC-technology in Bronderslev Denmark

DEFF Research Database (Denmark)

Perers, Bengt; Furbo, Simon; Yuan, Guofeng

2017-01-01

A new CSP plant combined with biomass CHP, using ORC technology, will be built and taken into operation in Bronderslev, Denmark during spring 2017. The price for Biomass is expected to increase with more and more use of this very limited energy source and then CSP will be cost effective in the long...... run, also in the Danish climate. Oil is used as heat transfer fluid instead of steam giving several advantages in this application for district heating at high latitudes. Total efficiencies and costs, competitive to PV plants. are expected....

Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source

Directory of Open Access Journals (Sweden)

Jiří Fink

2016-07-01

Full Text Available In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP. The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space heating. Electricity for the heat pumps is generated by a central CHP unit, which also provides thermal energy to a district heating system. The paper reviews recent smart grid control approaches for central and distributed levels. An online algorithm is described based on the earliest deadline first theory that can be used on the aggregator level to control the CHP and to give signals to the heat pump controllers if they should start or should wait. The central controller requires only a limited amount of privacy-insensitive information from the heat pump controllers about their deadlines, which the heat pump controllers calculate for themselves by model predictions. In this way, a robust heat pump and CHP control is obtained, which is able to minimize energy demand and results in the desired thermal comfort for the households. The simulations demonstrate fast computation times due to minor computational and communication overheads.

Modeling and Optimization of the Medium-Term Units Commitment of Thermal Power

Directory of Open Access Journals (Sweden)

Shengli Liao

2015-11-01

Full Text Available Coal-fired thermal power plants, which represent the largest proportion of China’s electric power system, are very sluggish in responding to power system load demands. Thus, a reasonable and feasible scheme for the medium-term optimal commitment of thermal units (MOCTU can ensure that the generation process runs smoothly and minimizes the start-up and shut-down times of thermal units. In this paper, based on the real-world and practical demands of power dispatch centers in China, a flexible mathematical model for MOCTU that uses equal utilization hours for the installed capacity of all thermal power plants as the optimization goal and that considers the award hours for MOCTU is developed. MOCTU is a unit commitment (UC problem with characteristics of large-scale, high dimensions and nonlinearity. For optimization, an improved progressive optimality algorithm (IPOA offering the advantages of POA is adopted to overcome the drawback of POA of easily falling into the local optima. In the optimization process, strategies of system operating capacity equalization and single station operating peak combination are introduced to move the target solution from the boundary constraints along the target isopleths into the feasible solution’s interior to guarantee the global optima. The results of a case study consisting of nine thermal power plants with 27 units show that the presented algorithm can obtain an optimal solution and is competent in solving the MOCTU with high efficiency and accuracy as well as that the developed simulation model can be applied to practical engineering needs.

Large-scale heat pumps in sustainable energy systems: System and project perspectives

Directory of Open Access Journals (Sweden)

Blarke Morten B.

2007-01-01

Full Text Available This paper shows that in support of its ability to improve the overall economic cost-effectiveness and flexibility of the Danish energy system, the financially feasible integration of large-scale heat pumps (HP with existing combined heat and power (CHP plants, is critically sensitive to the operational mode of the HP vis-à-vis the operational coefficient of performance, mainly given by the temperature level of the heat source. When using ground source for low-temperature heat source, heat production costs increases by about 10%, while partial use of condensed flue gasses for low-temperature heat source results in an 8% cost reduction. Furthermore, the analysis shows that when a large-scale HP is integrated with an existing CHP plant, the projected spot market situation in The Nordic Power Exchange (Nord Pool towards 2025, which reflects a growing share of wind power and heat-supply constrained power generation electricity, further reduces the operational hours of the CHP unit over time, while increasing the operational hours of the HP unit. In result, an HP unit at half the heat production capacity as the CHP unit in combination with a heat-only boiler represents as a possibly financially feasible alternative to CHP operation, rather than a supplement to CHP unit operation. While such revised operational strategy would have impacts on policies to promote co-generation, these results indicate that the integration of large-scale HP may jeopardize efforts to promote co-generation. Policy instruments should be designed to promote the integration of HP with lower than half of the heating capacity of the CHP unit. Also it is found, that CHP-HP plant designs should allow for the utilization of heat recovered from the CHP unit’s flue gasses for both concurrent (CHP unit and HP unit and independent operation (HP unit only. For independent operation, the recovered heat is required to be stored. .

Evaluation of the performance of combined cooling, heating, and power systems with dual power generation units

International Nuclear Information System (INIS)

Knizley, Alta A.; Mago, Pedro J.; Smith, Amanda D.

2014-01-01

The benefits of using a combined cooling, heating, and power system with dual power generation units (D-CCHP) is examined in nine different U.S. locations. One power generation unit (PGU) is operated at base load while the other is operated following the electric load. The waste heat from both PGUs is used for heating and for cooling via an absorption chiller. The D-CCHP configuration is studied for a restaurant benchmark building, and its performance is quantified in terms of operational cost, primary energy consumption (PEC), and carbon dioxide emissions (CDE). Cost spark spread, PEC spark spread, and CDE spark spread are examined as performance indicators for the D-CCHP system. D-CCHP system performance correlates well with spark spreads, with higher spark spreads signifying greater savings through implementation of a D-CCHP system. A new parameter, thermal difference, is introduced to investigate the relative performance of a D-CCHP system compared to a dual PGU combined heat and power system (D-CHP). Thermal difference, together with spark spread, can explain the variation in savings of a D-CCHP system over a D-CHP system for each location. The effect of carbon credits on operational cost savings with respect to the reference case is shown for selected locations. - Highlights: • We investigate benefits from using combined cooling, heating, and power systems. • A dual power generation unit configuration is considered for CCHP and CHP. • Spark spreads for cost, energy, and emissions correlate with potential savings. • Thermal difference parameter helps to explain variations in potential savings. • Carbon credits may increase cost savings where emissions savings are possible

A robust optimization approach for energy generation scheduling in microgrids

International Nuclear Information System (INIS)

Wang, Ran; Wang, Ping; Xiao, Gaoxi

2015-01-01

Highlights: • A new uncertainty model is proposed for better describing unstable energy demands. • An optimization problem is formulated to minimize the cost of microgrid operations. • Robust optimization algorithms are developed to transform and solve the problem. • The proposed scheme can prominently reduce energy expenses. • Numerical results provide useful insights for future investment policy making. - Abstract: In this paper, a cost minimization problem is formulated to intelligently schedule energy generations for microgrids equipped with unstable renewable sources and combined heat and power (CHP) generators. In such systems, the fluctuant net demands (i.e., the electricity demands not balanced by renewable energies) and heat demands impose unprecedented challenges. To cope with the uncertainty nature of net demand and heat demand, a new flexible uncertainty model is developed. Specifically, we introduce reference distributions according to predictions and field measurements and then define uncertainty sets to confine net and heat demands. The model allows the net demand and heat demand distributions to fluctuate around their reference distributions. Another difficulty existing in this problem is the indeterminate electricity market prices. We develop chance constraint approximations and robust optimization approaches to firstly transform and then solve the prime problem. Numerical results based on real-world data evaluate the impacts of different parameters. It is shown that our energy generation scheduling strategy performs well and the integration of combined heat and power (CHP) generators effectively reduces the system expenditure. Our research also helps shed some illuminations on the investment policy making for microgrids.

New CHP plant for a rubber products manufacturer; Nueva planta e cogeneración para un fabricante de productos de hule

Energy Technology Data Exchange (ETDEWEB)

Vila, R.; Martí, C.

2016-07-01

At the end of 2014 the company Industrias de Hule Galgo decided to undertake the installation project of an efficient CHP plant for its production plant, with the aim of bringing down energy costs and improving the company’s competitive position in the market. The new plant has already started its first operational phase. The project has comprised the installation of a single cycle with gas-powered gensets providing a total electrical capacity of 6.6 MW. This provides the necessary thermal oil for the production plant; covers 100% of the electrical power consumed by the industrial complex; and also generates cooling water, giving improved production capacity by supercooling the extrusion system. To execute these works, Industrias de Hule Galgo contracted the services of engineering company AESA to provide the engineering, procurement and construction of the CHP plant. (Author)

Optimal Energy Management of Multi-Microgrids with Sequentially Coordinated Operations

Directory of Open Access Journals (Sweden)

Nah-Oak Song

2015-08-01

Full Text Available We propose an optimal electric energy management of a cooperative multi-microgrid community with sequentially coordinated operations. The sequentially coordinated operations are suggested to distribute computational burden and yet to make the optimal 24 energy management of multi-microgrids possible. The sequential operations are mathematically modeled to find the optimal operation conditions and illustrated with physical interpretation of how to achieve optimal energy management in the cooperative multi-microgrid community. This global electric energy optimization of the cooperative community is realized by the ancillary internal trading between the microgrids in the cooperative community which reduces the extra cost from unnecessary external trading by adjusting the electric energy production amounts of combined heat and power (CHP generators and amounts of both internal and external electric energy trading of the cooperative community. A simulation study is also conducted to validate the proposed mathematical energy management models.

Multiobjective Optimization of a Counterrotating Type Pump-Turbine Unit Operated at Turbine Mode

Directory of Open Access Journals (Sweden)

Jin-Hyuk Kim

2014-05-01

Full Text Available A multiobjective optimization for improving the turbine output and efficiency of a counterrotating type pump-turbine unit operated at turbine mode was carried out in this work. The blade geometry of both the runners was optimized using a hybrid multiobjective evolutionary algorithm coupled with a surrogate model. Three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump-turbine unit. As major hydrodynamic performance parameters, the turbine output and efficiency were selected as objective functions with two design variables related to the hub profiles of both the runner blades. These objectives were numerically assessed at twelve design points selected by Latin hypercube sampling in the design space. Response surface approximation models for the objectives were constructed based on the objective function values at the design points. A fast nondominated sorting genetic algorithm for the local search coupled with the response surface approximation models was applied to determine the global Pareto-optimal solutions. The trade-off between the two objectives was determined and described with respect to the Pareto-optimal solutions. The results of this work showed that the turbine outputs and efficiencies of optimized pump-turbine units were simultaneously improved in comparison to the reference unit.

4E analysis and multi objective optimization of a micro gas turbine and solid oxide fuel cell hybrid combined heat and power system

Science.gov (United States)

Sanaye, Sepehr; Katebi, Arash

2014-02-01

Energy, exergy, economic and environmental (4E) analysis and optimization of a hybrid solid oxide fuel cell and micro gas turbine (SOFC-MGT) system for use as combined generation of heat and power (CHP) is investigated in this paper. The hybrid system is modeled and performance related results are validated using available data in literature. Then a multi-objective optimization approach based on genetic algorithm is incorporated. Eight system design parameters are selected for the optimization procedure. System exergy efficiency and total cost rate (including capital or investment cost, operational cost and penalty cost of environmental emissions) are the two objectives. The effects of fuel unit cost, capital investment and system power output on optimum design parameters are also investigated. It is observed that the most sensitive and important design parameter in the hybrid system is fuel cell current density which has a significant effect on the balance between system cost and efficiency. The selected design point from the Pareto distribution of optimization results indicates a total system exergy efficiency of 60.7%, with estimated electrical energy cost 0.057 kW-1 h-1, and payback period of about 6.3 years for the investment.

[Diagnosis and the technology for optimizing the medical support of a troop unit].

Science.gov (United States)

Korshever, N G; Polkovov, S V; Lavrinenko, O V; Krupnov, P A; Anastasov, K N

2000-05-01

The work is devoted to investigation of the system of military unit medical support with the use of principles and states of organizational diagnosis; development of the method allowing to assess its functional activity; and determination of optimization trends. Basing on the conducted organizational diagnosis and expert inquiry the informative criteria were determined which characterize the stages of functioning of the military unit medical support system. To evaluate the success of military unit medical support the complex multi-criteria pattern was developed and algorithm of this process optimization was substantiated. Using the results obtained, particularly realization of principles and states of decision taking theory in machine program it is possible to solve more complex problem of comparison between any number of military units: to dispose them according to priority decrease; to select the programmed number of the best and worst; to determine the trends of activity optimization in corresponding medical service personnel.

Thermodynamic and economic analysis of integrating lignocellulosic bioethanol production in a Danish combined heat and power unit

DEFF Research Database (Denmark)

Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

bioethanol production in the Danish CHP unit Avedøreværket 1. Numerical models of the plants were developed, and feasible integration solutions were identified and optimised using exergy analysis. Hour-wise production simulations were run over a reference year, and market prices and economic parameters from...

Carbon Debt Payback Time for a Biomass Fired CHP Plant—A Case Study from Northern Europe

Directory of Open Access Journals (Sweden)

Kristian Madsen

2018-03-01

Full Text Available The European Union (EU has experienced a large increase in the use of biomass for energy in the last decades. In 2015, biomass used to generate electricity, heat, and to a limited extent, liquid fuels accounted for 51% of the EU’s renewable energy production. Bioenergy use is expected to grow substantially to meet energy and climate targets for 2020 and beyond. This development has resulted in analyses suggesting the increased use of biomass for energy might initially lead to increased greenhouse gas (GHG emissions to the atmosphere, a so-called carbon debt. Here, we analyze carbon debt and payback time of substituting coal with forest residues for combined heat and power generation (CHP. The analysis is, in contrast to most other studies, based on empirical data from a retrofit of a CHP plant in northern Europe. The results corroborate findings of a carbon debt, here 4.4 kg CO2eq GJ−1. The carbon debt has a payback time of one year after conversion, and furthermore, the results show that GHG emissions are reduced to 50% relative to continued coal combustion after about 12 years. The findings support the use of residue biomass for energy as an effective means for climate change mitigation.

Thermodynamic and economic optimization of a solar-powered Stirling engine for micro-cogeneration purposes

International Nuclear Information System (INIS)

Ferreira, Ana C.; Nunes, Manuel L.; Teixeira, José C.F.; Martins, Luís A.S.B.; Teixeira, Senhorinha F.C.F.

2016-01-01

Micro-cogeneration systems are a promising technology for improving the energy efficiency near the end user, allowing the optimal use of the primary energy sources and significant reductions in carbon emissions. Its use, still incipient, has a great potential for applications in the residential sector. This study aims to develop a methodology for the thermal-economic optimization of micro cogeneration units using Stirling engine as prime mover and concentrated solar energy as the heat source. The thermal-economic optimization was formulated considering the maximization of the annual worth from the system operation, subjected to the nonlinear thermodynamic and economic constraints. The physical model includes the limitations in the heat transfer processes and losses due to the pumping effects and the costing methodology was defined considering a purchase cost equation representative of each system component. Geometric and operational parameters were selected as decision variables. Numerical simulations were developed in MatLab"® programming language and the Generalized Pattern Search optimization algorithm with MADSPositiveBasis2N was used in the determination of the optimal solution. A positive annual worth for the defined input simulation conditions and the economic analysis disclosed a system, economically attractive, with a payback period of approximately 10 years. - Highlights: • Application of optimization methods to model a renewable powered Stirling engine. • The aim is to optimize design of each plant-component for the best economical outcome. • The objective function is the maximization of annual worth of micro-CHP system. • The optimal solution is sensitive to electricity feed-in-tariffs and fuel prices fluctuations. • The optimal solution is economically attractive, with a payback period of ≈10 years.

Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm

Science.gov (United States)

Jin, Junchen

2016-01-01

The shunting schedule of electric multiple units depot (SSED) is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO) algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality. PMID:27436998

Optimizing the Shunting Schedule of Electric Multiple Units Depot Using an Enhanced Particle Swarm Optimization Algorithm

Directory of Open Access Journals (Sweden)

Jiaxi Wang

2016-01-01

Full Text Available The shunting schedule of electric multiple units depot (SSED is one of the essential plans for high-speed train maintenance activities. This paper presents a 0-1 programming model to address the problem of determining an optimal SSED through automatic computing. The objective of the model is to minimize the number of shunting movements and the constraints include track occupation conflicts, shunting routes conflicts, time durations of maintenance processes, and shunting running time. An enhanced particle swarm optimization (EPSO algorithm is proposed to solve the optimization problem. Finally, an empirical study from Shanghai South EMU Depot is carried out to illustrate the model and EPSO algorithm. The optimization results indicate that the proposed method is valid for the SSED problem and that the EPSO algorithm outperforms the traditional PSO algorithm on the aspect of optimality.

Discrete Optimization of Internal Part Structure via SLM Unit Structure-Performance Database

Directory of Open Access Journals (Sweden)

Li Tang

2018-01-01

Full Text Available The structural optimization of the internal structure of parts based on three-dimensional (3D printing has been recognized as being important in the field of mechanical design. The purpose of this paper is to present a creation of a unit structure-performance database based on the selective laser melting (SLM, which contains various structural units with different functions and records their structure and performance characteristics so that we can optimize the internal structure of parts directly, according to the database. The method of creating the unit structure-performance database was introduced in this paper and several structural units of the unit structure-performance database were introduced. The bow structure unit was used to show how to create the structure-performance database of the unit as an example. Some samples of the bow structure unit were designed and manufactured by SLM. These samples were tested in the WDW-100 compression testing machine to obtain their performance characteristics. After this, the paper collected all data regarding unit structure parameters, weight, performance characteristics, and other data; and, established a complete set of data from the bow structure unit for the unit structure-performance database. Furthermore, an aircraft part was reconstructed conveniently to be more lightweight according to the unit structure-performance database. Its weight was reduced by 36.8% when compared with the original structure, while the strength far exceeded the requirements.

Earliest Deadline Control of a Group of Heat Pumps with a Single Energy Source

NARCIS (Netherlands)

Fink, J.; van Leeuwen, Richard Pieter

2016-01-01

In this paper, we develop and investigate the optimal control of a group of 104 heat pumps and a central Combined Heat and Power unit (CHP). The heat pumps supply space heating and domestic hot water to households. Each house has a buffer for domestic hot water and a floor heating system for space

Economic potentials of CHP connected to district heat systems in Germany. Implementation of the EU Efficiency Directive; Wirtschaftliche Potenziale der waermeleitungsgebundenen Siedlungs-KWK in Deutschland. Umsetzung der EU-Energieeffizienzrichtlinie

Energy Technology Data Exchange (ETDEWEB)

Eikmeier, Bernd [Fraunhofer-Institut fuer Fertigungstechnik und Angewandte Materialforschung IFAM, Bremen (Germany). Organisationseinheit Systemanalyse; Bremen Univ. (Germany)

2015-07-01

The EU Efficiency Directive (2012/27/EU) is requiring all member states to carry out an evaluation of the potential for highly efficient CHP and the efficient use of district heating and cooling by December 2015. The German Federal Ministry of Economic Affairs and Energy appointed this task to the Fraunhofer Institute for Manufacturing and Advanced Materials, division for Energy Systems Analysis (formerly Bremer Energie Institut) in conjunction with other partners. The results for the sector district- and communal heating with CHP, sub-sectors private households, trade and services industry, are presented in this article.

Optimal inspection and replacement periods of the safety system in Wolsung Nuclear Power Plant Unit 1 with an optimized cost perspective

International Nuclear Information System (INIS)

Jinil Mok; Poong Hyun Seong

1996-01-01

In this work, a model for determining the optimal inspection and replacement periods of the safety system in Wolsung Nuclear Power Plant Unit 1 is developed, which is to minimize economic loss caused by inadvertent trip and the system failure. This model uses cost benefit analysis method and the part for optimal inspection period considers the human error. The model is based on three factors as follows: (i) The cumulative failure distribution function of the safety system, (ii) The probability that the safety system does not operate due to failure of the system or human error when the safety system is needed at an emergency condition and (iii) The average probability that the reactor is tripped due to the failure of system components or human error. The model then is applied to evaluate the safety system in Wolsung Nuclear Power Plant Unit 1. The optimal replacement periods which are calculated with proposed model differ from those used in Wolsung NPP Unit 1 by about a few days or months, whereas the optimal inspection periods are in about the same range. (author)

Fuel cell-based CHP system modelling using Artificial Neural Networks aimed at developing techno-economic efficiency maximization control systems

International Nuclear Information System (INIS)

Asensio, F.J.; San Martín, J.I.; Zamora, I.; Garcia-Villalobos, J.

2017-01-01

This paper focuses on the modelling of the performance of a Polymer Electrolyte Membrane Fuel Cell (PEMFC)-based cogeneration system to integrate it in hybrid and/or connected to grid systems and enable the optimization of the techno-economic efficiency of the system in which it is integrated. To this end, experimental tests on a PEMFC-based cogeneration system of 600 W of electrical power have been performed to train an Artificial Neural Network (ANN). Once the learning of the ANN, it has been able to emulate real operating conditions, such as the cooling water out temperature and the hydrogen consumption of the PEMFC depending on several variables, such as the electric power demanded, temperature of the inlet water flow to the cooling circuit, cooling water flow and the heat demanded to the CHP system. After analysing the results, it is concluded that the presented model reproduces with enough accuracy and precision the performance of the experimented PEMFC, thus enabling the use of the model and the ANN learning methodology to model other PEMFC-based cogeneration systems and integrate them in techno-economic efficiency optimization control systems. - Highlights: • The effect of the energy demand variation on the PEMFC's efficiency is predicted. • The model relies on experimental data obtained from a 600 W PEMFC. • It provides the temperature and the hydrogen consumption with good accuracy. • The range in which the global energy efficiency could be improved is provided.

Penempatan Optimal Phasor Measurement Unit (PMU dengan Integer Programming

Directory of Open Access Journals (Sweden)

Yunan Helmy Amrulloh

2013-09-01

Full Text Available Phasor Measurement Unit (PMU merupakan peralatan yang mampu memberikan pengukuran fasor tegangan dan arus secara real-time. PMU dapat digunakan untuk monitoring, proteksi dan kontrol pada sistem tenaga listrik. Tugas akhir ini membahas penempatan PMU secara optimal berdasarkan topologi jaringan sehingga sistem tenaga listrik  dapat diobservasi. Penempatan optimal PMU dirumuskan sebagai masalah Binary Integer Programming (BIP yang akan memberikan variabel dengan pilihan nilai (0,1 yang menunjukkan tempat yang harus dipasang PMU. Dalam tugas akhir ini, BIP diterapkan untuk menyelesaikan masalah penempatan PMU secara optimal pada sistem tenaga listrik  Jawa-Bali 500 KV yang selanjutnya diterapkan dengan penambahan konsep incomplete observability. Hasil simulasi menunjukkan bahwa penerapan BIP pada sistem dengan incomplete observability memberikan jumlah PMU yang lebih sedikit dibandingkan dengan sistem tanpa konsep incomplete observability.

Optimal stochastic coordinated scheduling of proton exchange membrane fuel cell-combined heat and power, wind and photovoltaic units in micro grids considering hydrogen storage

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2017-01-01

Highlights: •Stochastic model is proposed for coordinated scheduling of renewable energy sources. •The effect of combined heat and power is considered. •Hydrogen storage is considered for fuel cells. •Maximizing profits of micro grid is considered as objective function. •Considering the uncertainties of problem lead to profit increasing. -- Abstract: Nowadays, renewable energy sources and combined heat and power units are extremely used in micro grids, so it is necessary to schedule these units to improve the performance of the system. In this regard, a stochastic model is proposed in this paper to schedule proton exchange membrane fuel cell-combined heat and power, wind turbines, and photovoltaic units coordinately in a micro grid while considering hydrogen storage. Hydrogen storage strategy is considered for the operation of proton exchange membrane fuel cell-combined heat and power units. To consider stochastic generation of renewable energy source units in this paper, a scenario-based method is used. In this method, the uncertainties of electrical market price, the wind speed, and solar irradiance are considered. This stochastic scheduling problem is a mixed integer- nonlinear programming which considers the proposed objective function and variables of coordinated scheduling of PEMFC-CHP, wind turbines and photovoltaic units. It also considers hydrogen storage strategy and converts it to a mixed integer nonlinear problem. In this study a modified firefly algorithm is used to solve the problem. This method is examined on modified 33-bus distributed network as a MG for its performance.

Researching of the possibility of using absorption heat exchangers for creating the low return temperature heat supply systems based on CHP generation

Science.gov (United States)

Yavorovsky, Y. V.; Malenkov, A. S.; Zhigulina, Y. V.; Romanov, D. O.; Kurzanov, S. Y.

2017-11-01

This paper deals with the variant of modernization of the heat point within urban heat supply network in order to create the system of heat and cold supply on its basis, providing the suppliers with heat in cold months and with heat and cold in warm months. However, in cold months in the course of heating system operation, the reverse delivery water temperature is maintained below 40 °C. The analysis of heat and power indicators of the heat and cold supply system under different operating conditions throughout the year was conducted. The possibility to use the existing heat networks for the cold supply needs was estimated. The advantages of the system over the traditional heat supply systems that use Combined Heat and Power (CHP) plant as a heat source as exemplified by heat supply system from CHP with ST-80 turbine were demonstrated.

Optimal maintenance of a multi-unit system under dependencies

Science.gov (United States)

Sung, Ho-Joon

The availability, or reliability, of an engineering component greatly influences the operational cost and safety characteristics of a modern system over its life-cycle. Until recently, the reliance on past empirical data has been the industry-standard practice to develop maintenance policies that provide the minimum level of system reliability. Because such empirically-derived policies are vulnerable to unforeseen or fast-changing external factors, recent advancements in the study of topic on maintenance, which is known as optimal maintenance problem, has gained considerable interest as a legitimate area of research. An extensive body of applicable work is available, ranging from those concerned with identifying maintenance policies aimed at providing required system availability at minimum possible cost, to topics on imperfect maintenance of multi-unit system under dependencies. Nonetheless, these existing mathematical approaches to solve for optimal maintenance policies must be treated with caution when considered for broader applications, as they are accompanied by specialized treatments to ease the mathematical derivation of unknown functions in both objective function and constraint for a given optimal maintenance problem. These unknown functions are defined as reliability measures in this thesis, and theses measures (e.g., expected number of failures, system renewal cycle, expected system up time, etc.) do not often lend themselves to possess closed-form formulas. It is thus quite common to impose simplifying assumptions on input probability distributions of components' lifetime or repair policies. Simplifying the complex structure of a multi-unit system to a k-out-of-n system by neglecting any sources of dependencies is another commonly practiced technique intended to increase the mathematical tractability of a particular model. This dissertation presents a proposal for an alternative methodology to solve optimal maintenance problems by aiming to achieve the

Optimal design of modular cogeneration plants for hospital facilities and robustness evaluation of the results

International Nuclear Information System (INIS)

Gimelli, A.; Muccillo, M.; Sannino, R.

2017-01-01

Highlights: • A specific methodology has been set up based on genetic optimization algorithm. • Results highlight a tradeoff between primary energy savings (TPES) and simple payback (SPB). • Optimized plant configurations show TPES exceeding 18% and SPB of approximately three years. • The study aims to identify the most stable plant solutions through the robust design optimization. • The research shows how a deterministic definition of the decision variables could lead to an overestimation of the results. - Abstract: The widespread adoption of combined heat and power generation is widely recognized as a strategic goal to achieve significant primary energy savings and lower carbon dioxide emissions. In this context, the purpose of this research is to evaluate the potential of cogeneration based on reciprocating gas engines for some Italian hospital buildings. Comparative analyses have been conducted based on the load profiles of two specific hospital facilities and through the study of the cogeneration system-user interaction. To this end, a specific methodology has been set up by coupling a specifically developed calculation algorithm to a genetic optimization algorithm, and a multi-objective approach has been adopted. The results from the optimization problem highlight a clear trade-off between total primary energy savings (TPES) and simple payback period (SPB). Optimized plant configurations and management strategies show TPES exceeding 18% for the reference hospital facilities and multi–gas engine solutions along with a minimum SPB of approximately three years, thereby justifying the European regulation promoting cogeneration. However, designing a CHP plant for a specific energetic, legislative or market scenario does not guarantee good performance when these scenarios change. For this reason, the proposed methodology has been enhanced in order to focus on some innovative aspects. In particular, this study proposes an uncommon and effective approach

Study on the Effect of the Separating Unit Optimization on the Economy of Stable Isotope Separation

Directory of Open Access Journals (Sweden)

YANG Kun

2015-01-01

Full Text Available An economic criterion called as yearly net profit of single separating unit (YNPSSU was presented to evaluate the influence of structure optimization on the economy. Using YNPSSU as a criterion, economic analysis was carried out for the structure optimization of separating unit in the case of separating SiF4 to obtain the 28Si and 29Si isotope. YNPSSU was calculated and compared with that before optimization. The results showed that YNPSSU was increased by 12.3% by the structure optimization. Therefore, the structure optimization could increase the economy of the stable isotope separation effectively.

Rhombicuboctahedron unit cell based scaffolds for bone regeneration: geometry optimization with a mechanobiology - driven algorithm.

Science.gov (United States)

Boccaccio, Antonio; Fiorentino, Michele; Uva, Antonio E; Laghetti, Luca N; Monno, Giuseppe

2018-02-01

In a context more and more oriented towards customized medical solutions, we propose a mechanobiology-driven algorithm to determine the optimal geometry of scaffolds for bone regeneration that is the most suited to specific boundary and loading conditions. In spite of the huge number of articles investigating different unit cells for porous biomaterials, no studies are reported in the literature that optimize the geometric parameters of such unit cells based on mechanobiological criteria. Parametric finite element models of scaffolds with rhombicuboctahedron unit cell were developed and incorporated into an optimization algorithm that combines them with a computational mechanobiological model. The algorithm perturbs iteratively the geometry of the unit cell until the best scaffold geometry is identified, i.e. the geometry that allows to maximize the formation of bone. Performances of scaffolds with rhombicuboctahedron unit cell were compared with those of other scaffolds with hexahedron unit cells. We found that scaffolds with rhombicuboctahedron unit cell are particularly suited for supporting medium-low loads, while, for higher loads, scaffolds with hexahedron unit cells are preferable. The proposed algorithm can guide the orthopaedic/surgeon in the choice of the best scaffold to be implanted in a patient-specific anatomic region. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental broadband absorption enhancement in silicon nanohole structures with optimized complex unit cells.

Science.gov (United States)

Lin, Chenxi; Martínez, Luis Javier; Povinelli, Michelle L

2013-09-09

We design silicon membranes with nanohole structures with optimized complex unit cells that maximize broadband absorption. We fabricate the optimized design and measure the optical absorption. We demonstrate an experimental broadband absorption about 3.5 times higher than an equally-thick thin film.

Australian coal mine methane emissions mitigation potential using a Stirling engine-based CHP system

International Nuclear Information System (INIS)

Meybodi, Mehdi Aghaei; Behnia, Masud

2013-01-01

Methane, a major contributor to global warming, is a greenhouse gas emitted from coal mines. Abundance of coal mines and consequently a considerable amount of methane emission requires drastic measures to mitigate harmful effects of coal mining on the environment. One of the commonly adopted methods is to use emitted methane to fuel power generation systems; however, instability of fuel sources hinders the development of systems using conventional prime movers. To address this, application of Stirling engines may be considered. Here, we develop a techno-economic methodology for conducting an optimisation-based feasibility study on the application of Stirling engines as the prime movers of coal mine CHP systems from an economic and an environmental point of view. To examine the impact of environmental policies on the economics of the system, the two commonly implemented ones (i.e. a carbon tax and emissions trading scheme) are considered. The methodology was applied to a local coal mine. The results indicate that incorporating the modelled system not only leads to a substantial reduction in greenhouse gas emissions, but also to improved economics. Further, due to the heavy economic burden, the carbon tax scheme creates great incentive for coal mine industry to address the methane emissions. -- Highlights: •We study the application of Stirling engines in coal mine CHP systems. •We develop a thermo-economic approach based on the net present worth analysis. •We examine the impact of a carbon tax and ETS on the economics of the system. •The modeled system leads to a substantial reduction in greenhouse gas emissions. •Carbon tax provides a greater incentive to address the methane emissions

Increasing the flexibility of operational scheduling for a large-scale CHP plant used for generating district heat and electricity in order to meet the varying market demands; Steigerung der Einsatzflexibilitaet einer grossen KWK-Anlage zur Fernwaerme- und Stromerzeugung gemaess aktueller Marktanforderungen

Energy Technology Data Exchange (ETDEWEB)

Meierer, Matthias; Krupp, Roland; Stork, Rolf [Grosskraftwerk Mannheim AG, Mannheim (Germany)

2015-07-01

The substantial changes in the structure of German power supply plants pose high demands on the flexibility of the operational scheduling of conventional thermal power plants. Grosskraftwerk Mannheim AG is a power plant company that is operating a plant for combined power and district heat generation. The paper describes some measures which have been taken to improve the plant's operational flexibility. In addition, the associated technical systems and their functions, as well as the state of ongoing projects are outlined. Special focus is placed on topics related to issues such as ''district-heat storage unit of the new unit 9, flexibility of operational scheduling, and efficient CHP plant operation''.

Optimal investment paths for future renewable based energy systems - Using the optimisation model Balmorel

DEFF Research Database (Denmark)

Karlsson, Kenneth Bernard; Meibom, Peter

2008-01-01

that with an oil price at 100 $/barrel, a CO2 price at40 €/ton and the assumed penetration of hydrogen in the transport sector, it is economically optimal to cover more than 95% of the primary energy consumption for electricity and district heat by renewables in 2050. When the transport sector is converted......: A model for analyses of the electricity and CHP markets in the Baltic Sea Region. 〈www.Balmorel.com〉; 2001. [1

Comparison of operation optimization methods in energy system modelling

DEFF Research Database (Denmark)

Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

2013-01-01

In areas with large shares of Combined Heat and Power (CHP) production, significant introduction of intermittent renewable power production may lead to an increased number of operational constraints. As the operation pattern of each utility plant is determined by optimization of economics......, possibilities for decoupling production constraints may be valuable. Introduction of heat pumps in the district heating network may pose this ability. In order to evaluate if the introduction of heat pumps is economically viable, we develop calculation methods for the operation patterns of each of the used...... energy technologies. In the paper, three frequently used operation optimization methods are examined with respect to their impact on operation management of the combined technologies. One of the investigated approaches utilises linear programming for optimisation, one uses linear programming with binary...

Energetic and exergetic analysis of steam production for the extraction of coniferous essential oils

International Nuclear Information System (INIS)

Friso, Dario; Grigolato, Stefano; Cavalli, Raffaele

2011-01-01

Bioenergy production is optimal when the energy production process is both efficient and benefits from local resources. Energetic and exergetic analyses are applied to highlight efficiency differences between small-size systems that are based on the co-generation of heating and power (CHP) versus the co-generation of heating and power with steam production (CHP-S). Both systems use the Organic fluid Rankine Cycle (ORC). The recovery of heat from flue gases is considered to be a way of increasing energy efficiency. In the CHP-S case, steam (at low pressure) is used to extract essential oils from fresh twigs and needles of coniferous trees throughout a steam distillation process. When the systems work at a thermal combustion power of 1350 kW, energetic analysis shows that the energy efficiency of the CHP-S plant (89.4%) is higher than that of the CHP plant (77.9%). Exergetic analysis shows that the efficiency of the CHP-S plant is 2.2% higher than that of the CHP plant. -- Highlights: → Bioenergy production is optimal when the energy production process is efficient. → Energetic and exergetic analyses are applied to highlight efficiency differences between the co-generation of heating and power (CHP) versus the co-generation of heating and power with steam production (CHP-S). → The recovery of heat from flue gases is a way of increasing energy efficiency. → The energetic and exergetic analysis shows that the efficiency of the CHP-S plant is higher than that of the CHP plant.

Experience of Implementing a Distributed Control System for Thermal and Mechanical and Electrical Equipment at the South-West CHP

Energy Technology Data Exchange (ETDEWEB)

Babkin, K. V., E-mail: babkin@uztec.ru; Tsvetkov, M. S.; Kostyuk, R. I.; Chugin, A. V. [SC “South-West CHP” (Russian Federation); Bilenko, V. A.; Molchanov, K. A.; Fedunov, V. V. [JSC “Interautomatika” (Russian Federation)

2015-01-15

Results of implementing an SPPA-T3000-based unified distributed control system for thermal and mechanical and electrical equipment at the South-West CHP are discussed. Hardware solutions for integration with local control systems, control of electrical equipment in compliance with the standards IEC 61850, Modbus RTU, and communication between the plant control system and the System Operator of the Unified Power System are described.

Experience of Implementing a Distributed Control System for Thermal and Mechanical and Electrical Equipment at the South-West CHP

International Nuclear Information System (INIS)

Babkin, K. V.; Tsvetkov, M. S.; Kostyuk, R. I.; Chugin, A. V.; Bilenko, V. A.; Molchanov, K. A.; Fedunov, V. V.

2015-01-01

Results of implementing an SPPA-T3000-based unified distributed control system for thermal and mechanical and electrical equipment at the South-West CHP are discussed. Hardware solutions for integration with local control systems, control of electrical equipment in compliance with the standards IEC 61850, Modbus RTU, and communication between the plant control system and the System Operator of the Unified Power System are described

Evaluating biomass energy strategies for a UK eco-town with an MILP optimization model

International Nuclear Information System (INIS)

Keirstead, James; Samsatli, Nouri; Pantaleo, A. Marco; Shah, Nilay

2012-01-01

Recent years have shown a marked interest in the construction of eco-towns, showcase developments intended to demonstrate the best in ecologically-sensitive and energy-efficient construction. This paper examines one such development in the UK and considers the role of biomass energy systems. We present an integrated resource modelling framework that identifies an optimized low-cost energy supply system including the choice of conversion technologies, fuel sources, and distribution networks. Our analysis shows that strategies based on imported wood chips, rather than locally converted forestry residues, burned in a mix of ICE and ORC combined heat and power facilities offer the most promise. While there are uncertainties surrounding the precise environmental impacts of these solutions, it is clear that such biomass systems can help eco-towns to meet their target of an 80% reduction in greenhouse gas emissions. -- Highlights: ► An optimization model for urban biomass energy system design is presented. ► Tool selects technologies, operating rates, supply infrastructures. ► Five technology scenarios evaluated for a UK eco-town proposal. ► Results show ICE and ORC CHP units, fed by wood chips, promising. ► Results show biomass can help eco-towns achieve 80% GHG emission reductions.

Five-year outcomes for frontline brentuximab vedotin with CHP for CD30-expressing peripheral T-cell lymphomas.

Science.gov (United States)

Fanale, Michelle A; Horwitz, Steven M; Forero-Torres, Andres; Bartlett, Nancy L; Advani, Ranjana H; Pro, Barbara; Chen, Robert W; Davies, Andrew; Illidge, Tim; Uttarwar, Mayur; Lee, Shih-Yuan; Ren, Hong; Kennedy, Dana A; Shustov, Andrei R

2018-05-10

This phase 1 study evaluated frontline brentuximab vedotin in combination with cyclophosphamide, doxorubicin, and prednisone (BV+CHP; 6 cycles, then up to 10 cycles of brentuximab vedotin monotherapy) in 26 patients with CD30 + peripheral T-cell lymphoma, including 19 with systemic anaplastic large cell lymphoma. All patients (100%) achieved an objective response, with a complete remission (CR) rate of 92%; none received a consolidative stem cell transplant. After a median observation period of 59.6 months (range, 4.6-66.0) from first dose, neither the median progression-free survival (PFS) nor the median overall survival (OS) was reached. No progression or death was observed beyond 35 months. The estimated 5-year PFS and OS rates were 52% and 80%, respectively. Eighteen of 19 patients (95%) with treatment-emergent peripheral neuropathy (PN) reported resolution or improvement of symptoms. Thirteen patients (50%) remained in remission at the end of the study, with PFS ranging from 37.8+ to 66.0+ months. Eight of these 13 patients received the maximum 16 cycles of study treatment. These final results demonstrate durable remissions in 50% of patients treated with frontline BV+CHP, suggesting a potentially curative treatment option for some patients. This trial was registered at www.clinicaltrials.gov as #NCT01309789. © 2018 by The American Society of Hematology.

Ising Processing Units: Potential and Challenges for Discrete Optimization

Energy Technology Data Exchange (ETDEWEB)

Coffrin, Carleton James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nagarajan, Harsha [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bent, Russell Whitford [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-07-05

The recent emergence of novel computational devices, such as adiabatic quantum computers, CMOS annealers, and optical parametric oscillators, presents new opportunities for hybrid-optimization algorithms that leverage these kinds of specialized hardware. In this work, we propose the idea of an Ising processing unit as a computational abstraction for these emerging tools. Challenges involved in using and bench- marking these devices are presented, and open-source software tools are proposed to address some of these challenges. The proposed benchmarking tools and methodology are demonstrated by conducting a baseline study of established solution methods to a D-Wave 2X adiabatic quantum computer, one example of a commercially available Ising processing unit.

Investigation of Continuous Gas Engine CHP Operation on Biomass Producer Gas

DEFF Research Database (Denmark)

Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Jensen, Torben Kvist

2005-01-01

More than 2000 hours of gas engine operation with producer gas from biomass as fuel has been conducted on the gasification CHP demonstration and research plant, named “Viking” at the Technical University of Denmark. The gas engine is an integrated part of the entire gasification plant. The excess...... operates with varying excess of air due to variation in gas composition and thus stoichiometry, and a second where the excess of air in the exhaust gas is fixed and the flow rate of produced gas from the gasifier is varying. The interaction between the gas engine and the gasification system has been...... investigated. The engine and the plant are equipped with continuously data acquisition that monitors the operation including the composition of the producer gas and the flow. Producer gas properties and contaminations have been investigated. No detectable tar or particle content was observed...

An integrated DEA-COLS-SFA algorithm for optimization and policy making of electricity distribution units

International Nuclear Information System (INIS)

Azadeh, A.; Ghaderi, S.F.; Omrani, H.; Eivazy, H.

2009-01-01

This paper presents an integrated data envelopment analysis (DEA)-corrected ordinary least squares (COLS)-stochastic frontier analysis (SFA)-principal component analysis (PCA)-numerical taxonomy (NT) algorithm for performance assessment, optimization and policy making of electricity distribution units. Previous studies have generally used input-output DEA models for benchmarking and evaluation of electricity distribution units. However, this study proposes an integrated flexible approach to measure the rank and choose the best version of the DEA method for optimization and policy making purposes. It covers both static and dynamic aspects of information environment due to involvement of SFA which is finally compared with the best DEA model through the Spearman correlation technique. The integrated approach would yield in improved ranking and optimization of electricity distribution systems. To illustrate the usability and reliability of the proposed algorithm, 38 electricity distribution units in Iran have been considered, ranked and optimized by the proposed algorithm of this study.

Optimization of Fuel Consumption and Emissions for Auxiliary Power Unit Based on Multi-Objective Optimization Model

Directory of Open Access Journals (Sweden)

Yongpeng Shen

2016-02-01

Full Text Available Auxiliary power units (APUs are widely used for electric power generation in various types of electric vehicles, improvements in fuel economy and emissions of these vehicles directly depend on the operating point of the APUs. In order to balance the conflicting goals of fuel consumption and emissions reduction in the process of operating point choice, the APU operating point optimization problem is formulated as a constrained multi-objective optimization problem (CMOP firstly. The four competing objectives of this CMOP are fuel-electricity conversion cost, hydrocarbon (HC emissions, carbon monoxide (CO emissions and nitric oxide (NO x emissions. Then, the multi-objective particle swarm optimization (MOPSO algorithm and weighted metric decision making method are employed to solve the APU operating point multi-objective optimization model. Finally, bench experiments under New European driving cycle (NEDC, Federal test procedure (FTP and high way fuel economy test (HWFET driving cycles show that, compared with the results of the traditional fuel consumption single-objective optimization approach, the proposed multi-objective optimization approach shows significant improvements in emissions performance, at the expense of a slight drop in fuel efficiency.

Optimization of use of waste in the future energy system

International Nuclear Information System (INIS)

Muenster, Marie; Meibom, Peter

2011-01-01

Alternative uses of waste for energy production become increasingly interesting when considered from two perspectives, that of waste management and the energy system perspective. This paper presents the results of an enquiry into the use of waste in a future energy system. The analysis was performed using the energy system analysis model, Balmorel. The study is focused on Germany and the Nordic countries and demonstrates the optimization of both investments and production within the energy systems. The results present cost optimization excluding taxation concerning the use of waste for energy production in Denmark in a 2025 scenario with 48% renewable energy. Investments in a range of waste conversion technologies are facilitated, including waste incineration, co-combustion with coal, anaerobic digestion, and gasification. The most economically feasible solutions are found to be incineration of mixed waste, anaerobic digestion of organic waste, and gasification of part of the potential RDF (refuse derived fuel) for CHP (combined heat and power) production, while the remaining part is co-combusted with coal. Co-combustion mainly takes place in new coal-fired power plants, allowing investments to increase in comparison with a situation where only investments in waste incineration are allowed. -- Highlights: → The analysis is based on hourly chronological time steps, thereby taking dynamic properties of the energy system into account. → The system analyzed includes both the heat and the electricity market, which is important when analyzing e.g. CHP technologies. → The surrounding countries, which form part of the same electricity market, are included in the analysis. → New innovative Waste-to-Energy production plants have been modeled to allow for a more efficient and flexible use of waste. → The analysis includes economical optimization of operation and of investments in production and transmission of both electricity and heat.

Design of shared unit-dose drug distribution network using multi-level particle swarm optimization.

Science.gov (United States)

Chen, Linjie; Monteiro, Thibaud; Wang, Tao; Marcon, Eric

2018-03-01

Unit-dose drug distribution systems provide optimal choices in terms of medication security and efficiency for organizing the drug-use process in large hospitals. As small hospitals have to share such automatic systems for economic reasons, the structure of their logistic organization becomes a very sensitive issue. In the research reported here, we develop a generalized multi-level optimization method - multi-level particle swarm optimization (MLPSO) - to design a shared unit-dose drug distribution network. Structurally, the problem studied can be considered as a type of capacitated location-routing problem (CLRP) with new constraints related to specific production planning. This kind of problem implies that a multi-level optimization should be performed in order to minimize logistic operating costs. Our results show that with the proposed algorithm, a more suitable modeling framework, as well as computational time savings and better optimization performance are obtained than that reported in the literature on this subject.

Optimization in Fuzzy Economic Order Quantity (FEOQ Model with Deteriorating Inventory and Units Lost

Directory of Open Access Journals (Sweden)

Monalisha Pattnaik

2014-09-01

Full Text Available Background: This model presents the effect of deteriorating items in fuzzy optimal instantaneous replenishment for finite planning horizon. Accounting for holding cost per unit per unit time and ordering cost per order have traditionally been the case of modeling inventory systems in fuzzy environment. These imprecise parameters defined on a bounded interval on the axis of real numbers and the physical characteristics of stocked items dictate the nature of inventory policies implemented to manage and control in the production system.   Methods: The modified fuzzy EOQ (FEOQ model is introduced, it assumes that a percentage of the on-hand inventory is wasted due to deterioration and considered as an enhancement to EOQ model to determine the optimal replenishment quantity so that the net profit is maximized. In theoretical analysis, the necessary and sufficient conditions of the existence and uniqueness of the optimal solutions are proved and further the concavity of the fuzzy net profit function is established. Computational algorithm using the software LINGO 13.0 version is developed to find the optimal solution.   Results and conclusions: The results of the numerical analysis enable decision-makers to quantify the effect of units lost due to deterioration on optimizing the fuzzy net profit for the retailer. Finally, sensitivity analyses of the optimal solution with respect the major parameters are also carried out. Furthermore fuzzy decision making is shown to be superior then crisp decision making in terms of profit maximization. 

Optimal placement and sizing of multiple distributed generating units in distribution

Directory of Open Access Journals (Sweden)

D. Rama Prabha

2016-06-01

Full Text Available Distributed generation (DG is becoming more important due to the increase in the demands for electrical energy. DG plays a vital role in reducing real power losses, operating cost and enhancing the voltage stability which is the objective function in this problem. This paper proposes a multi-objective technique for optimally determining the location and sizing of multiple distributed generation (DG units in the distribution network with different load models. The loss sensitivity factor (LSF determines the optimal placement of DGs. Invasive weed optimization (IWO is a population based meta-heuristic algorithm based on the behavior of weeds. This algorithm is used to find optimal sizing of the DGs. The proposed method has been tested for different load models on IEEE-33 bus and 69 bus radial distribution systems. This method has been compared with other nature inspired optimization methods. The simulated results illustrate the good applicability and performance of the proposed method.

Sizing a solar dish Stirling micro-CHP system for residential application in diverse climatic conditions based on 3E analysis

International Nuclear Information System (INIS)

Moghadam, Ramin Shabanpour; Sayyaadi, Hoseyn; Hosseinzade, Hadi

2013-01-01

Highlights: • 3E analysis was performed on solar CHP systems. • Significant primary energy saving and greenhouse gas reduction were obtained. • The engine was sized so that it had the best economic sound. • Various criteria at different weathers were used for sizing the engine. - Abstract: A solar dish Stirling cogeneration system is considered to provide energy demands of a residential building. As energy demands of the building and output power of the engine are functions of weather condition and solar irradiation flux, the benchmark building was considered to be located in five different cities in Iran with diverse climatic and solar irradiation conditions. The proposed solar dish Stirling micro-CHP system was analyzed based on 3E analysis. The 3E analysis evaluated primary energy saving analysis (energy analysis), carbon dioxide emission reduction (environmental analysis) and payback period for return of investment (economic analysis) and was compared to a reference building that utilized primary energy carriers for its demands. Three scenarios were considered for assessment and sizing the solar dish Stirling engine. In the first scenario, size of the solar dish Stirling engine was selected based on the lowest annual electric power demand while, in second, the highest annual electric power consumption was considered to specify size of the engine. In the third scenario, a solar dish Stirling engine with constant output capacity was considered for the five locations. It was shown that implementing the solar dish Stirling micro-CHP system had good potential in primary energy saving and carbon dioxide emission reduction in all scenarios and acceptable payback period for return of the investment in some scenarios. Finally, the best scenario for selecting size of the engine in each city was introduced using the TOPSIS decision making method. It was demonstrated that, for dry weather, the first scenario was the best while, for hot and humid cities and

Clinical treatment planning optimization by Powell's method for gamma unit treatment system

International Nuclear Information System (INIS)

Yan Yulong; Shu Huazhong; Bao Xudong; Luo Limin; Bai Yi

1997-01-01

Purpose: This article presents a new optimization method for stereotactic radiosurgery treatment planning for gamma unit treatment system. Methods and Materials: The gamma unit has been utilized in stereotactic radiosurgery for about 30 years, but the usual procedure for a physician-physicist team to design a treatment plan is a trial-and-error approach. Isodose curves are viewed on two-dimensional computed tomography (CT) or magnetic resonance (MR) image planes, which is not only time consuming but also seldom achieves the optimal treatment plan, especially when the isocenter weights are regarded. We developed a treatment-planning system on a computer workstation in which Powell's optimization method is realized. The optimization process starts with the initial parameters (the number of iso centers as well as corresponding 3D iso centers' coordinates, collimator sizes, and weight factors) roughly determined by the physician-physicist team. The objective function can be changed to consider protection of sensitive tissues. Results: We use the plan parameters given by a well-trained physician-physicist team, or ones that the author give roughly as the initial parameters for the optimization procedure. Dosimetric results of optimization show a better high dose-volume conformation to the target volume compared to the doctor's plan. Conclusion: This method converges quickly and is not sensitive to the initial parameters. It achieves an excellent conformation of the estimated isodose curves with the contours of the target volume. If the initial parameters are varied, there will be a little difference in parameters' configuration, but the dosimetric results proved almost to be the same

National Accounts Energy Alliance : Field test and verification of CHP components and systems

Energy Technology Data Exchange (ETDEWEB)

Sweetser, R. [Exergy Partners Corporation, Herndon, VA (United States)

2003-07-01

Exergy is a consulting firm which specializes in capitalizing on opportunities that result from the nexus of utility deregulation and global climate change in both the construction and energy industries. The firm offers assistance in technical business and market planning, product development and high impact marketing and technology transfer programs. The author discussed National Accounts Energy Alliance (NAEA) program on distributed energy resources (DER) and identified some advantageous areas such as homeland security (less possible terrorist targets to be protected), food safety (protection of food supply and delivery system), reliability, power quality, energy density, grid congestion and energy price. In the future, an essential role in moderating energy prices for commercial buildings will probably be played by distributed generation (DG) and combined heat and power (CHP). The technical merits of these technologies is being investigated by national accounts and utilities partnering with non-profit organizations, the United States Department of Energy (US DOE), state governments and industry. In that light, in 2001 an Alliance program was developed, which allows investors to broaden their knowledge from the application and verification of Advanced Energy Technologies. This program was the result of a synergy between the American Gas Foundation and the Gas Technology Institute (GTI), and it assists investors with their strategic planning. It was proven that a customer-led Energy Technology Test and Verification Program (TA and VP) could be cost-effective and successful. The NAEA activities in five locations were reviewed and discussed. They were: (1) Russell Development, Portland, Oregon; (2) A and P-Waldbaums, Hauppage, New York; (3) HEB, Southern, Texas; (4) Cinemark, Plano, Texas; and McDonald's, Tampa, Florida. 4 tabs., figs.

Multi-objective Optimization of a Solar Humidification Dehumidification Desalination Unit

Science.gov (United States)

Rafigh, M.; Mirzaeian, M.; Najafi, B.; Rinaldi, F.; Marchesi, R.

2017-11-01

In the present paper, a humidification-dehumidification desalination unit integrated with solar system is considered. In the first step mathematical model of the whole plant is represented. Next, taking into account the logical constraints, the performance of the system is optimized. On one hand it is desired to have higher energetic efficiency, while on the other hand, higher efficiency results in an increment in the required area for each subsystem which consequently leads to an increase in the total cost of the plant. In the present work, the optimum solution is achieved when the specific energy of the solar heater and also the areas of humidifier and dehumidifier are minimized. Due to the fact that considered objective functions are in conflict, conventional optimization methods are not applicable. Hence, multi objective optimization using genetic algorithm which is an efficient tool for dealing with problems with conflicting objectives has been utilized and a set of optimal solutions called Pareto front each of which is a tradeoff between the mentioned objectives is generated.

Smart house-based optimal operation of thermal unit commitment for a smart grid considering transmission constraints

Science.gov (United States)

Howlader, Harun Or Rashid; Matayoshi, Hidehito; Noorzad, Ahmad Samim; Muarapaz, Cirio Celestino; Senjyu, Tomonobu

2018-05-01

This paper presents a smart house-based power system for thermal unit commitment programme. The proposed power system consists of smart houses, renewable energy plants and conventional thermal units. The transmission constraints are considered for the proposed system. The generated power of the large capacity renewable energy plant leads to the violated transmission constraints in the thermal unit commitment programme, therefore, the transmission constraint should be considered. This paper focuses on the optimal operation of the thermal units incorporated with controllable loads such as Electrical Vehicle and Heat Pump water heater of the smart houses. The proposed method is compared with the power flow in thermal units operation without controllable loads and the optimal operation without the transmission constraints. Simulation results show the validation of the proposed method.

Design and Optimization of an Integrated Biomass Gasification and Solid Oxide Fuel Cell System

DEFF Research Database (Denmark)

Bang-Møller, Christian

of the different operating conditions reveals an optimum for the chosen pressure ratio with respect to the resulting electrical efficiency. Furthermore, the SOFC operating temperature and fuel utilization should be maintained at a high level and the cathode temperature gradient maximized. Based on 1st and 2nd law...... based on biomass will improve the competitiveness of decentralized CHP production from biomass as well as move the development towards a more sustainable CHP production. The aim of this research is to contribute to enhanced electrical efficiencies and sustainability in future decentralized CHP plants....... The work deals with the coupling of thermal biomass gasification and solid oxide fuel cells (SOFCs), and specific focus is kept on exploring the potential performance of hybrid CHP systems based on the novel two-stage gasification concept and SOFCs. The two-stage gasification concept is developed...

Application of multi-criteria decision-making model for choice of the optimal solution for meeting heat demand in the centralized supply system in Belgrade

International Nuclear Information System (INIS)

Grujić, Miodrag; Ivezić, Dejan; Živković, Marija

2014-01-01

The expected growth of living standard, number of inhabitants and development of technology, industry and agriculture will cause a significant increase of energy consumption in cities. Three scenarios of energy sector development until 2030 and corresponding energy consumption for the city of Belgrade are analyzed in this paper. These scenarios consider different level of economic development, investments in energy sector, substitution of fossil fuels, introduction of renewable energy sources and implementation of energy efficiency measures. The proposed model for selection of optimal district heating system compares different options for fulfilling expected new heat demand through eight criteria for each scenario. Proposed options are combination of different energy sources and technologies for their use. The criteria weights are set according to Serbian economy and energy position. The criteria include financial aspects, environmental impact and availability of energy. Multi-criteria method ELECTRE (ELimination Et Choix Traduisant la REalite) is used as a tool for obtaining the optimal option. It is concluded that combination of CHP (combined heat and power) plant and centralized use of geothermal energy is optimal choice in the optimistic scenario. In the pessimistic and business as usual scenario the optimal option is combination of new gas boilers and centralized use of geothermal energy. - Highlights: • Three scenarios for meeting new heat demand are developed and assessed. • Constructing CHP (combined heat and power) is desirable in case of significant electricity price growth. • In all scenarios the chosen option includes using geothermal energy for heating

Multi-Objective Optimization of Start-up Strategy for Pumped Storage Units

Directory of Open Access Journals (Sweden)

Jinjiao Hou

2018-05-01

Full Text Available This paper proposes a multi-objective optimization method for the start-up strategy of pumped storage units (PSU for the first time. In the multi-objective optimization method, the speed rise time and the overshoot during the process of the start-up are taken as the objectives. A precise simulation platform is built for simulating the transient process of start-up, and for calculating the objectives based on the process. The Multi-objective Particle Swarm Optimization algorithm (MOPSO is adopted to optimize the widely applied start-up strategies based on one-stage direct guide vane control (DGVC, and two-stage DGVC. Based on the Pareto Front obtained, a multi-objective decision-making method based on the relative objective proximity is used to sort the solutions in the Pareto Front. Start-up strategy optimization for a PSU of a pumped storage power station in Jiangxi Province in China is conducted in experiments. The results show that: (1 compared with the single objective optimization, the proposed multi-objective optimization of start-up strategy not only greatly shortens the speed rise time and the speed overshoot, but also makes the speed curve quickly stabilize; (2 multi-objective optimization of strategy based on two-stage DGVC achieves better solution for a quick and smooth start-up of PSU than that of the strategy based on one-stage DGVC.

Integration of torrefaction in CHP plants – A case study

International Nuclear Information System (INIS)

Starfelt, Fredrik; Tomas Aparicio, Elena; Li, Hailong; Dotzauer, Erik

2015-01-01

Highlights: • We model the integration of a torrefaction reactor in a CHP plant. • Techno-economic analysis for the system is performed. • Flue gas integration of torrefaction show better performance. • Heat or electricity production is not compromised in the proposed system. - Abstract: Torrefied biomass shows characteristics that resemble those of coal. Therefore, torrefied biomass can be co-combusted with coal in existing coal mills and burners. This paper presents simulation results of a case study where a torrefaction reactor was integrated in an existing combined heat and power plant and sized to replace 25%, 50%, 75% or 100% of the fossil coal in one of the boilers. The simulations show that a torrefaction reactor can be integrated with existing plants without compromising heat or electricity production. Economic and sensitivity analysis show that the additional cost for integrating a torrefaction reactor is low which means that with an emission allowance cost of 37 €/ton CO 2 , the proposed integrated system can be profitable and use 100% renewable fuels. The development of subsidies will affect the process economy. The determinant parameters are electricity and fuel prices

Implications of the modelling of stratified hot water storage tanks in the simulation of CHP plants

Energy Technology Data Exchange (ETDEWEB)

Campos Celador, A., E-mail: alvaro.campos@ehu.es [ENEDI Research Group-University of the Basque Country, Departamento de Maquinas y Motores Termicos, E.T.S.I. de Bilbao Alameda de Urquijo, s/n 48013 Bilbao, Bizkaia (Spain); Odriozola, M.; Sala, J.M. [ENEDI Research Group-University of the Basque Country, Departamento de Maquinas y Motores Termicos, E.T.S.I. de Bilbao Alameda de Urquijo, s/n 48013 Bilbao, Bizkaia (Spain)

2011-08-15

Highlights: {yields} Three different modelling approaches for simulation of hot water tanks are presented. {yields} The three models are simulated within a residential cogeneration plant. {yields} Small differences in the results are found by an energy and exergy analysis. {yields} Big differences between the results are found by an advanced exergy analysis. {yields} Results on the feasibility study are explained by the advanced exergy analysis. - Abstract: This paper considers the effect that different hot water storage tank modelling approaches have on the global simulation of residential CHP plants as well as their impact on their economic feasibility. While a simplified assessment of the heat storage is usually considered in the feasibility studies of CHP plants in buildings, this paper deals with three different levels of modelling of the hot water tank: actual stratified model, ideal stratified model and fully mixed model. These three approaches are presented and comparatively evaluated under the same case of study, a cogeneration plant with thermal storage meeting the loads of an urbanisation located in the Bilbao metropolitan area (Spain). The case of study is simulated by TRNSYS for each one of the three modelling cases and the so obtained annual results are analysed from both a First and Second-Law-based viewpoint. While the global energy and exergy efficiencies of the plant for the three modelling cases agree quite well, important differences are found between the economic results of the feasibility study. These results can be predicted by means of an advanced exergy analysis of the storage tank considering the endogenous and exogenous exergy destruction terms caused by the hot water storage tank.

Power to the people

Energy Technology Data Exchange (ETDEWEB)

Lawton, G.

2002-03-02

The Harrison family from Chester in north-west England are currently testing a 'personal' combined heat and power (CHP) plant in their garage. The CHP plant, which was supplied by the New Zealand-based company WhisperTech, produces electricity and provides space heating and hot water. The floor-mounted WhisperTech unit produces about 6 kW of heat and 1 kW of electricity. A similar wall-mounted unit developed by BG Group produces up to 15 kW of heat and 1.1 kilowatt of electricity. These personal CHP plants are based on Stirling engines built using advanced materials that can cope with the high temperatures necessary for the efficient operation required to achieve energy savings compared with conventional boilers. Some 20 WhisperTech units and 12 BG Group units have been installed in UK homes. Units have also been fitted in houses in the Netherlands. The advantages of personal CHP systems, the operation of Stirling engines and the need to remain connected to the mains are explained.

Multi-objective optimization for the maximization of the operating share of cogeneration system in District Heating Network

International Nuclear Information System (INIS)

Franco, Alessandro; Versace, Michele

2017-01-01

Highlights: • Combined Heat and Power plants and civil/residential energy uses. • CHP plant supported by auxiliary boilers and thermal energy storage. • Definition of optimal operational strategies for cogeneration plants for District Heating. • Optimal-sized Thermal Energy Storage and a hybrid operational strategy. • Maximization of cogeneration share and reduction of time of operation of auxiliary boilers. - Abstract: The aim of the paper is to define optimal operational strategies for Combined Heat and Power plants connected to civil/residential District Heating Networks. The role of a reduced number of design variables, including a Thermal Energy Storage system and a hybrid operational strategy dependent on the storage level, is considered. The basic principle is to reach maximum efficiency of the system operation through the utilization of an optimal-sized Thermal Energy Storage. Objective functions of both energetic and combined energetic and economic can be considered. In particular, First and Second Law Efficiency, thermal losses of the storage, number of starts and stops of the combined heat and power unit are considered. Constraints are imposed to nullify the waste of heat and to operate the unit at its maximum efficiency for the highest possible number of consecutive operating hours, until the thermal tank cannot store more energy. The methodology is applied to a detailed case study: a medium size district heating system, in an urban context in the northern Italy, powered by a combined heat and power plant supported by conventional auxiliary boilers. The issues involving this type of thermal loads are also widely investigated in the paper. An increase of Second Law Efficiency of the system of 26% (from 0.35 to 0.44) can be evidenced, while the First Law Efficiency shifts from about 0.74 to 0.84. The optimization strategy permits of combining the economic benefit of cogeneration with the idea of reducing the energy waste and exergy losses.

Optimal Energy Management of Combined Cooling, Heat and Power in Different Demand Type Buildings Considering Seasonal Demand Variations

Directory of Open Access Journals (Sweden)

Akhtar Hussain

2017-06-01

Full Text Available In this paper, an optimal energy management strategy for a cooperative multi-microgrid system with combined cooling, heat and power (CCHP is proposed and has been verified for a test case of building microgrids (BMGs. Three different demand types of buildings are considered and the BMGs are assumed to be equipped with their own combined heat and power (CHP generators. In addition, the BMGs are also connected to an external energy network (EEN, which contains a large CHP, an adsorption chiller (ADC, a thermal storage tank, and an electric heat pump (EHP. By trading the excess electricity and heat energy with the utility grid and EEN, each BMG can fulfill its energy demands. Seasonal energy demand variations have been evaluated by selecting a representative day for the two extreme seasons (summer and winter of the year, among the real profiles of year-round data on electricity, heating, and cooling usage of all the three selected buildings. Especially, the thermal energy management aspect is emphasized where, bi-lateral heat trading between the energy supplier and the consumers, so-called energy prosumer concept, has been realized. An optimization model based on mixed integer linear programming has been developed for minimizing the daily operation cost of the EEN while fulfilling the energy demands of the BMGs. Simulation results have demonstrated the effectiveness of the proposed strategy.

Structural optimization of the fibre-reinforced composite substructure in a three-unit dental bridge.

Science.gov (United States)

Shi, Li; Fok, Alex S L

2009-06-01

Failures of fixed partial dentures (FPDs) made of fibre-reinforced composites (FRC) have been reported in many clinical and in vitro studies. The types of failure include debonding at the composite-tooth interface, delamination of the veneering material from the FRC substructure and fracture of the pontic. The design of the FRC substructure, i.e. the position and orientation of the fibres, will affect the fracture resistance of the FPD. The purpose of this study was to find an optimal arrangement of the FRC substructure, by means of structural optimization, which could minimize the failure-initiating stresses in a three-unit FPD. A structural optimization method mimicking biological adaptive growth was developed for orthotropic materials such as FRC and incorporated into the finite element (FE) program ABAQUS. Using the program, optimization of the fibre positions and directions in a three-unit FPD was carried out, the aim being to align the fibre directions with those of the maximum principal stresses. The optimized design was then modeled and analyzed to verify the improvements in mechanical performance of the FPD. Results obtained from the optimization suggested that the fibres should be placed at the bottom of the pontic, forming a U-shape substructure that extended into the connectors linking the teeth and the pontic. FE analyses of the optimized design indicated stress reduction in both the veneering composite and at the interface between the veneer and the FRC substructure. The optimized design obtained using FE-based structural optimization can potentially improve the fracture resistance of FPDs by reducing some of the failure-initiating stresses. Optimization methods can therefore be a useful tool to provide sound scientific guidelines for the design of FRC substructures in FPDs.

Integrated energy markets and varying degrees of liberalisation: price links, bundled sales and CHP production exemplified by Northern European experiences

International Nuclear Information System (INIS)

Jacobsen, H.K.; Fristrup, P.; Munksgaard, J.

2006-01-01

Liberalisation of energy markets has during the last 20 years been gradually introduced in many countries. The liberalisation has led to concerns regarding the markets' state of competition and fears that market power existence can result in less efficiency gains than what is expected from liberalisation. Concerns have also been raised as to whether specific consumer groups will be affected by limited competition in markets. Much of the concern has been concentrated on the electricity markets, but the development of energy sectors with integration of activities within natural gas, electricity and the oil sector creates the need to examine market power aspects across these markets. This paper examines the concentration trends in the Northern European markets for electricity and natural gas, combined with regional district heating aspects, especially with respect to the situation in Denmark. The situation with natural gas companies supplying to both small-scale CHP and to retail heat customers is discussed, for instance, which changes of regulatory regime for domestic heating customers should be considered when the natural gas market is being liberalised? The interlinked nature of the energy markets is described and examples of impacts from one market with limited competition to other markets with seemingly well-functioning competition are given. The specific case of large CHP production facilities with output on the regulated district heating market and the competitive Nordic electricity market is examined. How much of the fluctuations in price experienced in electricity markets should be reflected in the price of heating supplies? To which degree do the heating customers have to bear the burden of low-electricity market prices? Regulation of liberalised markets is discussed focusing on the interaction between one regulated market and the related energy markets that are liberalised. Existing regulation on the markets are compared to a situation where liberalisation

Integrated energy markets and varying degrees of liberalisation: Price links, bundled sales and CHP production exemplified by Northern European experiences

International Nuclear Information System (INIS)

Klinge Jacobsen, Henrik; Fristrup, Peter; Munksgaard, Jesper

2006-01-01

Liberalisation of energy markets has during the last 20 years been gradually introduced in many countries. The liberalisation has led to concerns regarding the markets' state of competition and fears that market power existence can result in less efficiency gains than what is expected from liberalisation. Concerns have also been raised as to whether specific consumer groups will be affected by limited competition in markets. Much of the concern has been concentrated on the electricity markets, but the development of energy sectors with integration of activities within natural gas, electricity and the oil sector creates the need to examine market power aspects across these markets. This paper examines the concentration trends in the Northern European markets for electricity and natural gas, combined with regional district heating aspects, especially with respect to the situation in Denmark. The situation with natural gas companies supplying to both small-scale CHP and to retail heat customers is discussed, for instance, which changes of regulatory regime for domestic heating customers should be considered when the natural gas market is being liberalised? The interlinked nature of the energy markets is described and examples of impacts from one market with limited competition to other markets with seemingly well-functioning competition are given. The specific case of large CHP production facilities with output on the regulated district heating market and the competitive Nordic electricity market is examined. How much of the fluctuations in price experienced in electricity markets should be reflected in the price of heating supplies? To which degree do the heating customers have to bear the burden of low-electricity market prices? Regulation of liberalised markets is discussed focusing on the interaction between one regulated market and the related energy markets that are liberalised. Existing regulation on the markets are compared to a situation where liberalisation

Fuel cell power plants for decentralised CHP applications; Brennstoffzellen-Kraftwerke fuer dezentrale KWK-Anwendungen

Energy Technology Data Exchange (ETDEWEB)

Ohmer, Martin; Mattner, Katja [FuelCell Energy Solutions GmbH, Dresden (Germany)

2015-06-01

Fuel cells are the most efficient technology to convert chemical energy into electricity and heat and thus they could have a major impact on reducing fuel consumption, CO{sub 2} and other emissions (NO{sub x}, SO{sub x} and particulate matter). Fired with natural or biogas and operated with an efficiency of up to 49 % a significant reduction of fuel costs can be achieved in decentralised applications. Combined heat and power (CHP) configurations add value for a wide range of industrial applications. The exhaust heat of approximately 400 C can be utilised for heating purposes and the production of steam. Besides, it can be also fed directly to adsorption cooling systems. With more than 110 fuel cell power plants operating worldwide, this technology is a serious alternative to conventional gas turbines or gas engines.

Thermal and economical optimization of air conditioning units with vapor compression refrigeration system

Energy Technology Data Exchange (ETDEWEB)

Sanaye, S.; Malekmohammadi, H.R. [Iran University of Science and Technology, Tehran (Iran). Dept. of Mechanical Engineering

2004-09-01

A new method of thermal and economical optimum design of air conditioning units with vapor compression refrigeration system, is presented. Such a system includes compressor, condenser, evaporator, centrifugal and axial fans. Evaporator and condenser temperatures, their heating surface areas (frontal surface area and number of tubes), centrifugal and axial fan powers, and compressor power are among the design variables. The data provided by manufacturers for fan (volume flow rate versus pressure drop) and compressor power (using evaporator and condenser temperatures) was used to choose these components directly from available data for consumers. To study the performance of the system under various situations, and implementing the optimization procedure, a simulation program including all thermal and geometrical parameters was developed. The objective function for optimization was the total cost per unit cooling load of the system including capital investment for components as well as the required electricity cost. To find the system design parameters, this objective function was minimized by Lagrange multipliers method. The effects of changing the cooling load on optimal design parameters were studied. (author)

Comparison of particle swarm optimization and dynamic programming for large scale hydro unit load dispatch

International Nuclear Information System (INIS)

Cheng Chuntian; Liao Shengli; Tang Zitian; Zhao Mingyan

2009-01-01

Dynamic programming (DP) is one of classic and sophisticated optimization methods that have successfully been applied to solve the problem of hydro unit load dispatch (HULD). However, DP will be faced with the curse of dimensionality with the increase of unit number and installed generating capacity of hydropower station. With the appearance of the huge hydropower station similar to the Three George with 26 generators of 700 MW, it is hard to apply the DP to large scale HULD problem. It is crucial to seek for other optimization techniques in order to improve the operation quality and efficiency. Different with the most of literature about power generation scheduling that focused on the comparisons of novel PSO algorithms with other techniques, the paper will pay emphasis on comparison study of PSO with DP based on a case hydropower station. The objective of study is to seek for an effective and feasible method for the large scale of hydropower station of the current and future in China. This paper first compares the performance of PSO and DP using a sample load curve of the Wujiangdu hydropower plant located in the upper stream of the Yangtze River in China and contained five units with the installed capacity of 1250 MW. Next, the effect of different load interval and unit number on the optimal results and efficiency of two methods has also been implemented. The comparison results show that the PSO is feasible for HULD. Furthermore, we simulated the effect of the magnitude of unit number and load capacity on the optimal results and cost time. The simulation comparisons show that PSO has a great advantage over DP in the efficiency and will be one of effective methods for HULD problem of huge hydropower stations.

Comparison of particle swarm optimization and dynamic programming for large scale hydro unit load dispatch

Energy Technology Data Exchange (ETDEWEB)

Cheng Chuntian, E-mail: ctcheng@dlut.edu.c [Department of Civil and Hydraulic Engineering, Dalian University of Technology, 116024 Dalian (China); Liao Shengli; Tang Zitian [Department of Civil and Hydraulic Engineering, Dalian University of Technology, 116024 Dalian (China); Zhao Mingyan [Department of Environmental Science and Engineering, Tsinghua University, 100084 Beijing (China)

2009-12-15

Dynamic programming (DP) is one of classic and sophisticated optimization methods that have successfully been applied to solve the problem of hydro unit load dispatch (HULD). However, DP will be faced with the curse of dimensionality with the increase of unit number and installed generating capacity of hydropower station. With the appearance of the huge hydropower station similar to the Three George with 26 generators of 700 MW, it is hard to apply the DP to large scale HULD problem. It is crucial to seek for other optimization techniques in order to improve the operation quality and efficiency. Different with the most of literature about power generation scheduling that focused on the comparisons of novel PSO algorithms with other techniques, the paper will pay emphasis on comparison study of PSO with DP based on a case hydropower station. The objective of study is to seek for an effective and feasible method for the large scale of hydropower station of the current and future in China. This paper first compares the performance of PSO and DP using a sample load curve of the Wujiangdu hydropower plant located in the upper stream of the Yangtze River in China and contained five units with the installed capacity of 1250 MW. Next, the effect of different load interval and unit number on the optimal results and efficiency of two methods has also been implemented. The comparison results show that the PSO is feasible for HULD. Furthermore, we simulated the effect of the magnitude of unit number and load capacity on the optimal results and cost time. The simulation comparisons show that PSO has a great advantage over DP in the efficiency and will be one of effective methods for HULD problem of huge hydropower stations.

Comparison of particle swarm optimization and dynamic programming for large scale hydro unit load dispatch

Energy Technology Data Exchange (ETDEWEB)

Chun-tian Cheng; Sheng-li Liao; Zi-Tian Tang [Dept. of Civil and Hydraulic Engineering, Dalian Univ. of Technology, 116024 Dalian (China); Ming-yan Zhao [Dept. of Environmental Science and Engineering, Tsinghua Univ., 100084 Beijing (China)

2009-12-15

Dynamic programming (DP) is one of classic and sophisticated optimization methods that have successfully been applied to solve the problem of hydro unit load dispatch (HULD). However, DP will be faced with the curse of dimensionality with the increase of unit number and installed generating capacity of hydropower station. With the appearance of the huge hydropower station similar to the Three George with 26 generators of 700 MW, it is hard to apply the DP to large scale HULD problem. It is crucial to seek for other optimization techniques in order to improve the operation quality and efficiency. Different with the most of literature about power generation scheduling that focused on the comparisons of novel PSO algorithms with other techniques, the paper will pay emphasis on comparison study of PSO with DP based on a case hydropower station. The objective of study is to seek for an effective and feasible method for the large scale of hydropower station of the current and future in China. This paper first compares the performance of PSO and DP using a sample load curve of the Wujiangdu hydropower plant located in the upper stream of the Yangtze River in China and contained five units with the installed capacity of 1250 MW. Next, the effect of different load interval and unit number on the optimal results and efficiency of two methods has also been implemented. The comparison results show that the PSO is feasible for HULD. Furthermore, we simulated the effect of the magnitude of unit number and load capacity on the optimal results and cost time. The simulation comparisons show that PSO has a great advantage over DP in the efficiency and will be one of effective methods for HULD problem of huge hydropower stations. (author)

CO{sub 2} reduction: potential of heat pumps when used together with combined heat and power units; Potentiel energetique des pompes a chaleur combinees au couplage chaleur-force. Pour une reduction maximale des emissions de CO{sub 2} et pour une production de courant fossile avec reduction des emissions de CO{sub 2} en Suisse - Rapport final

Energy Technology Data Exchange (ETDEWEB)

Rognon, F.

2005-07-01

This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the potential of using heat pumps in combination with Combined Heat and Power (CHP) units as a replacement for fossil-fuel fired heating units in Switzerland. The electrical power produced by the CHP units can be used to provide power for the drives of heat pump systems. The author states that the fossil fuel consumption and the resulting emissions of carbon dioxide can be halved using this combination. Also, even more efficient systems using power produced in larger combined-cycle power generation are discussed. Further examples of how fossil-fired power generation in combination with heat pumps can not only replace fossil-fuelled heating systems but also provide additional electricity too are given. This overview includes figures on the potential of such combined systems.

Performance of U.S. hybrid distributed energy systems: Solar photovoltaic, battery and combined heat and power

International Nuclear Information System (INIS)

Shah, Kunal K.; Mundada, Aishwarya S.; Pearce, J.M.

2015-01-01

Highlights: • Simulated PV + battery + CHP hybrid systems deployed in three U.S. regions. • Used hybrid optimization model for electric renewable pro microgrid analysis. • Limited size of each sub-module to singe family house size. • Results show that the electricity generated meets residential load demand. • Hybrid systems are technically viable in hot, moderate and cold climates in U.S. - Abstract: Until recently, the relatively high levelized cost of electricity from solar photovoltaic (PV) technology limited deployment; however, recent cost reductions, combined with various financial incentives and innovative financing techniques, have made PV fully competitive with conventional sources in many American regions. In addition, the costs of electrical storage have also declined enough to make PV + battery systems potentially economically viable for a mass-scale off-grid low-emission transition. However, many regions in the U.S. (e.g. Northern areas) cannot have off-grid PV systems without prohibitively large battery systems. Small-scale combined heat and power (CHP) systems provide a potential solution for off-grid power backup of residential-scale PV + battery arrays, while also minimizing emissions from conventional sources. Thus, an opportunity is now available to maximize the use of solar energy and gain the improved efficiencies possible with CHPs to deploy PV + battery + CHP systems throughout the U.S. The aim of this study is to determine the technical viability of such systems by simulating PV + battery + CHP hybrid systems deployed in three representative regions in the U.S., using the Hybrid Optimization Model for Electric Renewable (HOMER) Pro Microgrid Analysis tool. The results show that the electricity generated by each component of the hybrid system can be coupled to fulfill the residential load demand. A sensitivity analysis of these hybrid off grid systems is carried out as a function capacity factor of both the PV and CHP units. The

Development and test of a Stirling engine driven by waste gases for the micro-CHP system

International Nuclear Information System (INIS)

Li Tie; Tang Dawei; Li Zhigang; Du Jinglong; Zhou Tian; Jia Yu

2012-01-01

In recent years, micro-CHP systems are attracting world attention. As one kind of external heating engines, Stirling engines could be applied to the micro-CHP systems driven by solar, biogas, mid-high temperature waste gases and many other heat sources. The development of a Stirling engine driven by mid-high temperature waste gases is presented first. The thermodynamic design method, the key parameters of the designed Stirling engine and its combustion chamber adapted for waste gases are described in detail. Then the performance test of the Stirling engine is carried out. During the test, the temperature of the heater head is monitored by thermocouples, and the pressure of the working fluid helium in the Stirling engine is monitored by pressure sensors. The relationships among the output shaft power, torque and speed are studied, and the pressure losses of the working fluid in the heat exchanger system are also analyzed. The test results demonstrate that the output shaft power could reach 3476 W at 1248 RPM, which is in good agreement with the predicted value of 3901 W at 1500 RPM. The test results confirm the fact that Stirling engines driven by mid-high temperature waste gases are able to achieve a valuable output power for engineering application. - Highlights: ► A β-type Stirling engine whose output power could reach about 3.5 kW is developed by ourselves. ► Waste gases are used as the heat source to drive the Stirling engine. ► Test on the relationship among the power, torque, and speed are presented. ► The pressure changing process of the working fluid in the heat exchanger system during the test is recorded and analyzed.

Optimal Placement of Phasor Measurement Units with New Considerations

DEFF Research Database (Denmark)

Su, Chi; Chen, Zhe

2010-01-01

Conventional phasor measurement unit (PMU) placement methods normally use the number of PMU installations as the objective function which is to be minimized. However, the cost of one installation of PMU is not always the same in different locations. It depends on a number of factors. One of these......Conventional phasor measurement unit (PMU) placement methods normally use the number of PMU installations as the objective function which is to be minimized. However, the cost of one installation of PMU is not always the same in different locations. It depends on a number of factors. One...... of these factors is taken into account in the proposed PMU placement method in this paper, which is the number of adjacent branches to the PMU located buses. The concept of full topological observability is adopted and a version of binary particle swarm optimization (PSO) algorithm is utilized. Results from...

A deterministic approach for performance assessment and optimization of power distribution units in Iran

International Nuclear Information System (INIS)

Azadeh, A.; Ghaderi, S.F.; Omrani, H.

2009-01-01

This paper presents a deterministic approach for performance assessment and optimization of power distribution units in Iran. The deterministic approach is composed of data envelopment analysis (DEA), principal component analysis (PCA) and correlation techniques. Seventeen electricity distribution units have been considered for the purpose of this study. Previous studies have generally used input-output DEA models for benchmarking and evaluation of electricity distribution units. However, this study considers an integrated deterministic DEA-PCA approach since the DEA model should be verified and validated by a robust multivariate methodology such as PCA. Moreover, the DEA models are verified and validated by PCA, Spearman and Kendall's Tau correlation techniques, while previous studies do not have the verification and validation features. Also, both input- and output-oriented DEA models are used for sensitivity analysis of the input and output variables. Finally, this is the first study to present an integrated deterministic approach for assessment and optimization of power distributions in Iran

The Added Economic and Environmental Value of Solar Thermal Systems in Microgrids with CombinedHeat and Power

Energy Technology Data Exchange (ETDEWEB)

Marnay, Chris; Stadler, Michael; Cardoso, Goncalo; Megel, Olivier; Lai, Judy; Siddiqui, Afzal

2009-08-15

The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions and annual energy costs, a microgrid's distributed energy resources (DER) adoption problem is formulated as a mixed-integer linear program. The objective is minimization of annual energy costs. This paper focuses on analysis of the optimal interaction of solar thermal systems, which can be used for domestic hot water, space heating and/or cooling, and micro-CHP systems in the California service territory of San Diego Gas and Electric (SDG&E). Contrary to typical expectations, our results indicate that despite the high solar radiation in southern California, fossil based CHP units are dominant, even with forecast 2020 technology and costs. A CO2 pricing scheme would be needed to incent installation of combined solar thermal absorption chiller systems, and no heat storage systems are adopted. This research also shows that photovoltaic (PV) arrays are favored by CO2 pricing more than solar thermal adoption.

The Added Economic and Environmental Value of Solar Thermal Systems in Microgrids with CombinedHeat and Power

International Nuclear Information System (INIS)

Marnay, Chris; Stadler, Michael; Cardoso, Goncalo; Megel, Olivier; Lai, Judy; Siddiqui, Afzal

2009-01-01

The addition of solar thermal and heat storage systems can improve the economic, as well as environmental attraction of micro-generation systems, e.g. fuel cells with or without combined heat and power (CHP) and contribute to enhanced CO2 reduction. However, the interactions between solar thermal collection and storage systems and CHP systems can be complex, depending on the tariff structure, load profile, etc. In order to examine the impact of solar thermal and heat storage on CO2 emissions and annual energy costs, a microgrid's distributed energy resources (DER) adoption problem is formulated as a mixed-integer linear program. The objective is minimization of annual energy costs. This paper focuses on analysis of the optimal interaction of solar thermal systems, which can be used for domestic hot water, space heating and/or cooling, and micro-CHP systems in the California service territory of San Diego Gas and Electric (SDG and amp;E). Contrary to typical expectations, our results indicate that despite the high solar radiation in southern California, fossil based CHP units are dominant, even with forecast 2020 technology and costs. A CO2 pricing scheme would be needed to incent installation of combined solar thermal absorption chiller systems, and no heat storage systems are adopted. This research also shows that photovoltaic (PV) arrays are favored by CO2 pricing more than solar thermal adoption.

Seeking optimal renal replacement therapy delivery in intensive care units.

Science.gov (United States)

Kocjan, Marinka; Brunet, Fabrice P

2010-01-01

Globally, critical care environments within health care organizations strive to provide optimal quality renal replacement therapy (RRT), an artificial replacement for lost kidney function. Examination of RRT delivery model literature and a case study review of the multidisciplinary-mixed RRT delivery model utilized within a closed medical surgical intensive care unit illustrates the organizational and clinical management of specialized resource and multidisciplinary roles. The successful utilization of a specific RRT delivery model is dependent upon resource availability.

CHP HIGHER EDUCATION, SCHOLARSHIPS AND DEMAND ABROAD ARE POLITICS (1942-1947

Directory of Open Access Journals (Sweden)

Suat ZEYREK

2016-04-01

Full Text Available Turkey was followed by a very slow development in the course of the republic’s first year in higher education.By 1955, there are only two universities in the three cities in Turkey.Although the new university will be declared opened by Ismet Inonu’s mouth several times it was not possible for various reasons.Turkey’s economic situation, the shortage of trained personel and it has been hampered by severe conditions of World War II.But even more important excuses should have prevented the spread of higher education in Turkey. This article will be presented in the light of the real causes of the problem of archival sources mentioned above.Period ruling party, the CHP’s higher education policy followed in scholarships and dormitories were investigated.CHP likely to promote higher education in the first primary education spread to the base and thus wants to create a higher demand.For this reason, it is necessary first of all to build infrastructure for higher education institutions and rules.Coming from big cities in different regions of Anatolia youth to take education to all students experience difficulties and inclusive, egalitarian policies were followed.

Thermal-economic optimization of an air-cooled heat exchanger unit

International Nuclear Information System (INIS)

Alinia Kashani, Amir Hesam; Maddahi, Alireza; Hajabdollahi, Hassan

2013-01-01

Thermodynamic modeling and optimal design of an air-cooled heat exchanger (ACHE) unit are developed in this study. For this purpose, ε–NTU method and mathematical relations are applied to estimate the fluids outlet temperatures and pressure drops in tube and air sides. The main goal of this study is minimizing of two conflicting objective functions namely the temperature approach and the minimum total annual cost, simultaneously. For this purpose, fast and elitist non-dominated sorting genetic-algorithm (NSGA-II) is applied to minimize the objective functions by considering ten design parameters. In addition, a set of typical constraints, governing on the ACHE unit design, is subjected to obtain more practical optimum design points. Furthermore, sensitivity analysis of change in the objective functions, when the optimum design parameters vary, is conducted and the degree of each parameter on conflicting objective functions has been investigated. Finally, a selection procedure of the best optimum point is introduced and final optimum design point is determined. -- Highlights: ► Multi-objective optimization of air-cooled heat exchanger. ► Considering ten new design parameters in this type of heat exchanger. ► A detailed cost function is used to estimate the heat exchanger investment cost. ► Presenting a mathematical relation for optimum total cost vs. temperature approach. ► The sensitivity analysis of parameters in the optimum situation

Flue gas emissions from gas-fired cogeneration units <25 MWe

International Nuclear Information System (INIS)

Nielsen, M.; Wit, J. de

1997-01-01

A total of 900 MW e gas driven combined heat and power (CHP) has now been established in Denmark based on gas engines and gas turbine units less than 25 MW e each. Of the 900 MW e approx. 750 MW e are based on gas engines. Biogas is used as fuel for some 32 MW e of these. Emission limits for NO x and CO are 650 mg/nm 3 (ref. 5% O 2 and electrical efficiency 30% LCV). There is at present no limit for unburned hydrocarbons (UHC) for gas engines or gas turbines. The average emission of unburned hydrocarbons for the Danish gas engine driven CHP units is equal to approx. 3,5% of the fuel used. It is the target of this report to provide the basis for evaluating the planned UHC limit and possible adjustments of the present limit for NO x emission. The average NO x emission from gas turbines slightly exceeds the NO x emission from gas engines. This is due to a number of older gas turbines. Modern gas turbines can achieve significantly lower NO x emission compared to engines. The NO x emission from biogas driven engines is significantly higher than that of natural gas driven units. This is mainly due to NO x -unfavourable engine settings and the use of older units, as there are no legislation concerning NO x emission for the majority of these biogas driven units. The emission of CO and UHC is lower from gas turbines than from gas engines. The NO x emission can be reduced by SCR Catalyst systems. In Denmark 3 gas engine installations use this commercially available technology. Oxidation catalyst for UHC reduction at modern gas engine installations has proven relatively unsuccesful in Denmark until now. Only limited reductions are achieved and many catalysts are toxificated in less than 100 hours of operation. However, long-term field testing of promising UHC reducing catalysts is now being made. UHC reduction by incineration is at the prototype stage. No such plant has yet been set up in Denmark. (Abstract Truncated)

Optimization of the scheduled maintenance on the power units of the nuclear power plants with WWER

International Nuclear Information System (INIS)

Skalozubov, V.I.; Kovrizhkin, Yu.L.; Kolykhanov, V.N.; Kochneva, V.Yu.; Urbanskij, V.V.

2008-01-01

The advanced international and domestic experience in the field of the maintenance optimization of the power units of NPPs, as well, as on the base of the planning optimization, the maintenance organization and carrying out, the technical maintenance and repair control system automatization, the testing and monitoring optimization during the service process, the modernization of the technology and technical tools of the maintenance service and control is represented

Scalable unit commitment by memory-bounded ant colony optimization with A{sup *} local search

Energy Technology Data Exchange (ETDEWEB)

Saber, Ahmed Yousuf; Alshareef, Abdulaziz Mohammed [Department of Electrical and Computer Engineering, King Abdulaziz University, P.O. Box 80204, Jeddah 21589 (Saudi Arabia)

2008-07-15

Ant colony optimization (ACO) is successfully applied in optimization problems. Performance of the basic ACO for small problems with moderate dimension and searching space is satisfactory. As the searching space grows exponentially in the large-scale unit commitment problem, the basic ACO is not applicable for the vast size of pheromone matrix of ACO in practical time and physical computer-memory limit. However, memory-bounded methods prune the least-promising nodes to fit the system in computer memory. Therefore, the authors propose memory-bounded ant colony optimization (MACO) in this paper for the scalable (no restriction for system size) unit commitment problem. This MACO intelligently solves the limitation of computer memory, and does not permit the system to grow beyond a bound on memory. In the memory-bounded ACO implementation, A{sup *} heuristic is introduced to increase local searching ability and probabilistic nearest neighbor method is applied to estimate pheromone intensity for the forgotten value. Finally, the benchmark data sets and existing methods are used to show the effectiveness of the proposed method. (author)

Optimal maintenance policy incorporating system level and unit level for mechanical systems

Science.gov (United States)

Duan, Chaoqun; Deng, Chao; Wang, Bingran

2018-04-01

The study works on a multi-level maintenance policy combining system level and unit level under soft and hard failure modes. The system experiences system-level preventive maintenance (SLPM) when the conditional reliability of entire system exceeds SLPM threshold, and also undergoes a two-level maintenance for each single unit, which is initiated when a single unit exceeds its preventive maintenance (PM) threshold, and the other is performed simultaneously the moment when any unit is going for maintenance. The units experience both periodic inspections and aperiodic inspections provided by failures of hard-type units. To model the practical situations, two types of economic dependence have been taken into account, which are set-up cost dependence and maintenance expertise dependence due to the same technology and tool/equipment can be utilised. The optimisation problem is formulated and solved in a semi-Markov decision process framework. The objective is to find the optimal system-level threshold and unit-level thresholds by minimising the long-run expected average cost per unit time. A formula for the mean residual life is derived for the proposed multi-level maintenance policy. The method is illustrated by a real case study of feed subsystem from a boring machine, and a comparison with other policies demonstrates the effectiveness of our approach.

Techno-economic optimization of flexible biogas concepts in the context of EEG

International Nuclear Information System (INIS)

Barchmann, Tino; Lauer, Markus

2014-01-01

Due to the introduction of direct marketing and flexibility premium of renewable energy by the Renewable Energy Act 2012 (EEG 2012), incentives were created to favour a more demand-oriented power supply from biogas plants (BGA). The decision for such an operational mode depends on on-site conversion units on the economic outcome of the plants throughout the whole operating time. To install new plants or transfer existing plants into a flexible mode of operation, investments in additional and more efficient combined heat and power plants (CHP), in additional gas and/or heat storage and other technical components are necessary. The analyses show that the flexibility premium, as an extra of the market premium model, creates the greatest incentive for a more flexible generation of electricity from biogas. In addition, an intelligent management optimization can generate additional revenues on EPEX SPOT SE and balancing energy market. The additional revenues of more demand-oriented power supply from biogas plants are highly dependent on plant-specific conditions. From an economic perspective, a duplication of the installed electrical capacity seems to be the most beneficial option for a transition to a demand-driven operation mode of an average biogas model plant under the current legal framework (EEG 2012).

Combined Heat and Power: Effective Energy Solutions for a Sustainable Future

Energy Technology Data Exchange (ETDEWEB)

Shipley, Ms. Anna [Sentech, Inc.; Hampson, Anne [Energy and Environmental Analysis, Inc., an ICF Company; Hedman, Mr. Bruce [Energy and Environmental Analysis, Inc., an ICF Company; Garland, Patricia W [ORNL; Bautista, Paul [Sentech, Inc.

2008-12-01

Combined Heat and Power (CHP) solutions represent a proven and effective near-term energy option to help the United States enhance energy efficiency, ensure environmental quality, promote economic growth, and foster a robust energy infrastructure. Using CHP today, the United States already avoids more than 1.9 Quadrillion British thermal units (Quads) of fuel consumption and 248 million metric tons of carbon dioxide (CO{sub 2}) emissions annually compared to traditional separate production of electricity and thermal energy. This CO{sub 2} reduction is the equivalent of removing more than 45 million cars from the road. In addition, CHP is one of the few options in the portfolio of energy alternatives that combines environmental effectiveness with economic viability and improved competitiveness. This report describes in detail the four key areas where CHP has proven its effectiveness and holds promise for the future as an: (1) Environmental Solution: Significantly reducing CO{sub 2} emissions through greater energy efficiency; (2) Competitive Business Solution: Increasing efficiency, reducing business costs, and creating green-collar jobs; (3) Local Energy Solution: Deployable throughout the US; and (4) Infrastructure Modernization Solution: Relieving grid congestion and improving energy security. CHP should be one of the first technologies deployed for near-term carbon reductions. The cost-effectiveness and near-term viability of widespread CHP deployment place the technology at the forefront of practical alternative energy solutions such as wind, solar, clean coal, biofuels, and nuclear power. Clear synergies exist between CHP and most other technologies that dominate the energy and environmental policy dialogue in the country today. As the Nation transforms how it produces, transports, and uses the many forms of energy, it must seize the clear opportunity afforded by CHP in terms of climate change, economic competitiveness, energy security, and infrastructure

Optimization Solutions for Improving the Performance of the Parallel Reduction Algorithm Using Graphics Processing Units

Directory of Open Access Journals (Sweden)

Ion LUNGU

2012-01-01

Full Text Available In this paper, we research, analyze and develop optimization solutions for the parallel reduction function using graphics processing units (GPUs that implement the Compute Unified Device Architecture (CUDA, a modern and novel approach for improving the software performance of data processing applications and algorithms. Many of these applications and algorithms make use of the reduction function in their computational steps. After having designed the function and its algorithmic steps in CUDA, we have progressively developed and implemented optimization solutions for the reduction function. In order to confirm, test and evaluate the solutions' efficiency, we have developed a custom tailored benchmark suite. We have analyzed the obtained experimental results regarding: the comparison of the execution time and bandwidth when using graphic processing units covering the main CUDA architectures (Tesla GT200, Fermi GF100, Kepler GK104 and a central processing unit; the data type influence; the binary operator's influence.

Optimization in Fuzzy Economic Order Quantity (FEOQ) Model with Deteriorating Inventory and Units Lost

OpenAIRE

Monalisha Pattnaik

2014-01-01

Background: This model presents the effect of deteriorating items in fuzzy optimal instantaneous replenishment for finite planning horizon. Accounting for holding cost per unit per unit time and ordering cost per order have traditionally been the case of modeling inventory systems in fuzzy environment. These imprecise parameters defined on a bounded interval on the axis of real numbers and the physical characteristics of stocked items dictate the nature of inventory policies implemented ...

Solid oxide fuel cells towards real life applications. Final report

Energy Technology Data Exchange (ETDEWEB)

2010-07-01

Solid Oxide Fuel Cells offer a clean and efficient way of producing electricity and heat from a wide selection of fuels. The project addressed three major challenges to be overcome by the technology to make commercialisation possible. (1) At the cell level, increased efficiency combined with production cost reduction has been achieved through an optimization of the manufacturing processes, b) by using alternative raw materials with a lower purchase price and c) by introducing a new generation of fuel cells with reduced loss and higher efficiency. (2) At the stack level, production cost reduction is reduced and manufacturing capacity is increased through an optimization of the stack production. (3) At the system level, development of integrated hotbox concepts for the market segments distributed generation (DG), micro combined heat and power (mCHP), and auxiliary power units (APU) have been developed. In the mCHP segment, two concepts have been developed and validated with regards to market requirements and scalability. In the APU-segment, different types of reformers have been tested and it has been proven that diesel can be reformed through appropriate reformers. Finally, operation experience and feedback has been gained by deployment of stacks in the test facility at the H.C. OErsted Power Plant (HCV). This demonstration has been carried out in collaboration between TOFC and DONG Energy Power A/S (DONG), who has participated as a subcontractor to TOFC. The demonstration has given valuable knowledge and experience with design, start-up and operation of small power units connected to the grid and future development within especially the mCHP segment will benefit from this. In this report, the project results are described for each of the work packages in the project. (Author)

Marketing opportunities for CHP electricity in a virtual power plant. Direct and indirect marketing of flexibility; Vermarktungschancen fuer KWK-Strom im virtuellen Kraftwerk. Direkte und indirekte Flexibilitaetsvermarktung

Energy Technology Data Exchange (ETDEWEB)

Otto, Achim; Baumgart, Bastian [Trianel GmbH, Aachen (Germany). Abt. Virtuelle Kraftwerke

2013-07-15

The increasingly fluctuating feed-in of electricity by means of a rapid expansion of renewable energies results in an increasing demand for flexible performance for the regulation of production and consumption. An important part of the necessary flexibility could be provided by CHP plants. Their potential of flexibility is not always fully exploited.

Integration of biomass into urban energy systems for heat and power. Part I: An MILP based spatial optimization methodology

International Nuclear Information System (INIS)

Pantaleo, Antonio M.; Giarola, Sara; Bauen, Ausilio; Shah, Nilay

2014-01-01

Highlights: • MILP tool for optimal sizing and location of heating and CHP plants to serve residential energy demand. • Trade-offs between local vs centralized heat generation, district heating vs natural gas distribution systems. • Assessment of multi-biomass supply chains and biomass to biofuel processing technologies. • Assessment of the key factors influencing the use of biomass and district heating in residential areas. - Abstract: The paper presents a mixed integer linear programming (MILP) approach to optimize multi-biomass and natural gas supply chain strategic design for heat and power generation in urban areas. The focus is on spatial and temporal allocation of biomass supply, storage, processing, transport and energy conversion (heat and CHP) to match the heat demand of residential end users. The main aim lies on the representation of the relationships between the biomass processing and biofuel energy conversion steps, and on the trade-offs between centralized district heating plants and local heat generation systems. After a description of state of the art and research trends in urban energy systems and bioenergy modelling, an application of the methodology to a generic case study is proposed. With the assumed techno-economic parameters, biomass based thermal energy generation results competitive with natural gas, while district heating network results the main option for urban areas with high thermal energy demand density. Potential further applications of this model are also described, together with main barriers for development of bioenergy routes for urban areas

Design process and instrumentation of a low NOx wire-mesh duct burner for micro-cogeneration unit

Energy Technology Data Exchange (ETDEWEB)

Ramadan, O.B.; Gauthier, J.E.D. [Carleton Univ., Ottawa, ON (Canada). Dept. of Mechanical and Aerospace Engineering; Hughes, P.M.; Brandon, R. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

2007-07-01

Air pollution and global climate change have become a serious environmental problem leading to increasingly stringent government regulations worldwide. New designs and methods for improving combustion systems to minimize the production of toxic emissions, like nitrogen oxides (NOx) are therefore needed. In order to control smog, acid rain, ozone depletion, and greenhouse-effect warming, a reduction of nitrogen oxide is necessary. One alternative for combined electrical power and heat generation (CHP) are micro-cogeneration units which use a micro-turbine as a prime mover. However, to increase the efficiencies of these units, micro-cogeneration technology still needs to be developed further. This paper described the design process, building, and testing of a new low NOx wire-mesh duct burner (WMDB) for the development of a more efficient micro-cogeneration unit. The primary goal of the study was to develop a practical and simple WMDB, which produces low emissions by using lean-premixed surface combustion concept and its objectives were separated into four phases which were described in this paper. Phase I involved the design and construction of the burner. Phase II involved a qualitative flow visualization study for the duct burner premixer to assist the new design of the burner by introducing an efficient premixer that could be used in this new application. Phase III of this research program involved non-reacting flow modeling on the burner premixer flow field using a commercial computational fluid dynamic model. In phase IV, the reacting flow experimental investigation was performed. It was concluded that the burner successfully increased the quantity and the quality of the heat released from the micro-CHP unit and carbon monoxide emissions of less than 9 ppm were reached. 3 refs., 3 figs.

Optimizing landslide susceptibility zonation: Effects of DEM spatial resolution and slope unit delineation on logistic regression models

Science.gov (United States)

Schlögel, R.; Marchesini, I.; Alvioli, M.; Reichenbach, P.; Rossi, M.; Malet, J.-P.

2018-01-01

We perform landslide susceptibility zonation with slope units using three digital elevation models (DEMs) of varying spatial resolution of the Ubaye Valley (South French Alps). In so doing, we applied a recently developed algorithm automating slope unit delineation, given a number of parameters, in order to optimize simultaneously the partitioning of the terrain and the performance of a logistic regression susceptibility model. The method allowed us to obtain optimal slope units for each available DEM spatial resolution. For each resolution, we studied the susceptibility model performance by analyzing in detail the relevance of the conditioning variables. The analysis is based on landslide morphology data, considering either the whole landslide or only the source area outline as inputs. The procedure allowed us to select the most useful information, in terms of DEM spatial resolution, thematic variables and landslide inventory, in order to obtain the most reliable slope unit-based landslide susceptibility assessment.

Are high penetrations of commercial cogeneration good for society?

Science.gov (United States)

Keen, Jeremy F.; Apt, Jay

2016-12-01

Low natural gas prices, market reports and evidence from New York State suggest that the number of commercial combined heat and power (CHP) installations in the United States will increase by 2%-9% annually over the next decade. We investigate how increasing commercial CHP penetrations may affect net emissions, the distribution network, and total system energy costs. We constructed an integrated planning and operations model that maximizes owner profit through sizing and operation of CHP on a realistic distribution feeder in New York. We find that a greater penetration of CHP reduces both total system energy costs and network congestion. Commercial buildings often have low and inconsistent heat loads, which can cause low fuel utilization efficiencies, low CHP rates-of-return and diminishing avoided emissions as CHP penetration increases. In the northeast, without policy intervention, a 5% penetration of small commercially owned CHP would increase CO2 emissions by 2% relative to the bulk power grid. Low emission CHP installations can be encouraged with incentives that promote CHP operation only during times of high heat loads. Time-varying rates, such as time-of-day and seasonal rates, are one option and were shown to reduce customer emissions without reducing profits. In contrast, natural gas rate discounts, a common incentive for industrial CHP in some states, can encourage CHP operation during low heat loads and thus increase emissions.

Optimized Matching Lift Unit Transmission Ratio of Engine Driven Ducted Fan

Directory of Open Access Journals (Sweden)

Xiao Senlin

2018-01-01

Full Text Available As a kind of VTOL technology, ducted fan is not only used by many kinds of aircrafts, but also one of the trends of the future aircraft lift system, and attracts more and more attention. For an engine driven ducted fan lift unit, involving the engine and ducted fan matching problem, the form of transmission and transmission ratio are the key design parameters. In order to design and develop a ducted fan aircraft reasonably, a thrust test platform was set up to connect the engine with the ducted fan through the belt driving. The matching relationship between the engine and the transmission system was experimentally studied and the optimal transmission ratio was determined. The results showed that the optimal transmission ratio for the engine 1 is 2.2:1, and for the engine 2, the optimal transmission ratio should be 2.95:1 based on the current ducted and movable blade aerofoil design. At this time, the lift will exceed 130 kg•f, meeting the aircraft's original design requirements.

Encouraging Combined Heat and Power in California Buildings

Energy Technology Data Exchange (ETDEWEB)

Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Groissbock, Markus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cardoso, Goncalo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Muller, Andreas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lai, Judy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2013-02-01

Governor Brown’s research priorities include an additional 6.5 GW of combined heat and power (CHP) by 2030. As of 2009, roughly 0.25 GW of small natural gas and biogas fired CHP is documented by the Self-Generation Incentive Program (SGIP) database. The SGIP is set to expire, and the anticipated grid de-carbonization based on the development of 20 GW of renewable energy will influence the CHP adoption. Thus, an integrated optimization approach for this analysis was chosen that allows optimizing the adoption of distributed energy resources (DER) such as photovoltaics (PV), CHP, storage technologies, etc. in the California commercial sector from the building owners’ perspective. To solve this DER adoption problem the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed by the Lawrence Berkeley National Laboratory and used extensively to address the problem of optimally investing and scheduling DER under multiple settings, has been used. The application of CHP at large industrial sites is well known, and much of its potential is already being realized. Conversely, commercial sector CHP, especially those above 50 to 100 kW peak electricity load, is widely overlooked. In order to analyze the role of DER in CO₂ reduction, 147 representative sites in different climate zones were selected from the California Commercial End Use Survey (CEUS). About 8000 individual optimization runs, with different assumptions for the electric tariffs, natural gas costs, marginal grid CO₂ emissions, and nitrogen oxide treatment costs, SGIP, fuel cell lifetime, fuel cell efficiency, PV installation costs, and payback periods for investments have been performed. The most optimistic CHP potential contribution in this sector in 2020 will be 2.7 GW. However, this result requires a SGIP in 2020, 46% average electric efficiency for fuel cells, a payback period for investments of 10 years, and a CO₂ focused approach of the building owners. In

WORKING PARK-FUEL CELL COMBINED HEAT AND POWER SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Allan Jones

2003-09-01

This report covers the aims and objectives of the project which was to design, install and operate a fuel cell combined heat and power (CHP) system in Woking Park, the first fuel cell CHP system in the United Kingdom. The report also covers the benefits that were expected to accrue from the work in an understanding of the full technology procurement process (including planning, design, installation, operation and maintenance), the economic and environmental performance in comparison with both conventional UK fuel supply and conventional CHP and the commercial viability of fuel cell CHP energy supply in the new deregulated energy markets.

Development of a biorefinery optimized biofuel supply curve for the western United States

Science.gov (United States)

Nathan Parker; Peter Tittmann; Quinn Hart; Richard Nelson; Ken Skog; Anneliese Schmidt; Edward Gray; Bryan Jenkins

2010-01-01

A resource assessment and biorefinery siting optimization model was developed and implemented to assess potential biofuel supply across the Western United States from agricultural, forest, urban, and energy crop biomass. Spatial information including feedstock resources, existing and potential refinery locations and a transportation network model is provided to a mixed...

Analysis of a CHP plant in a municipal solid waste landfill in the South of Spain

International Nuclear Information System (INIS)

Chacartegui, Ricardo; Carvalho, Monica; Abrahão, Raphael; Becerra, José

2015-01-01

The most effective strategy to manage and treat solid urban residues, with the least environmental impact as well as lowest economic and energy costs, is a challenge for sustainability in current society, who actually pay for the final management of these residues. This manuscript analyzes the potential of biogas generation in an urban solid residue treatment plant, and the potential use for cogeneration in situ at the landfill. The objective is to identify the energy potential associated with the landfill and its potential use to accelerate the evaporation of leachate through the supply of heat, reducing the risks of exceeding the collection capacity of the leachate ponds. The change in legislation for generation within the special regime in Spain (2014) introduced a sudden change in the direction of energy policies, which affected significantly the profitability of these facilities. This manuscript analyzes the application of both legislations, previous (2007) and current (2014), for the case of a cogeneration system installed in this landfill. The results obtained indicate that even with a much more restrictive legislation in force, acceptable values are obtained for the evaluation of the investment – however, better results were obtained for the previous legislation that favored the special regime. The new regulation constrains the maximum and minimum annual operating hours for landfill cogeneration. It results in relevant periods with limited use of biogas for electricity generation. Biogas storage for delayed future consumption in the same installation and biogas selling for external use in boilers are proposed as options for this biogas in excess. They can reduce greenhouse gases emissions from the non-used biogas and can improve the economic results of the facility. - Highlights: • Analysis of biogas generation capacity in an existing landfill at South of Spain. • Analysis of the integration of gas engine for cogeneration. • CHP integration for

An Optimal Calibration Method for a MEMS Inertial Measurement Unit

Directory of Open Access Journals (Sweden)

Bin Fang

2014-02-01

Full Text Available An optimal calibration method for a micro-electro-mechanical inertial measurement unit (MIMU is presented in this paper. The accuracy of the MIMU is highly dependent on calibration to remove the deterministic errors of systematic errors, which also contain random errors. The overlapping Allan variance is applied to characterize the types of random error terms in the measurements. The calibration model includes package misalignment error, sensor-to-sensor misalignment error and bias, and a scale factor is built. The new concept of a calibration method, which includes a calibration scheme and a calibration algorithm, is proposed. The calibration scheme is designed by D-optimal and the calibration algorithm is deduced by a Kalman filter. In addition, the thermal calibration is investigated, as the bias and scale factor varied with temperature. The simulations and real tests verify the effectiveness of the proposed calibration method and show that it is better than the traditional method.

The effectiveness of absorption heat pumps application for the increase of economic efficiency of CHP operation

Directory of Open Access Journals (Sweden)

Luzhkovoy Dmitriy S.

2017-01-01

Full Text Available The article deals with a comparative analysis of CHP operational efficiency in various working modes before and after the absorption heat pumps installation. The calculation was performed using a mathematical model of the extraction turbine PT- 80/100-130/13. Absorption heat pumps of LLC “OKB Teplosibmash” were used as AHP models for the analysis. The most effective way of absorption lithium-bromide heat pumps application as a part of the turbine PT-80/100-130/13 turned out to be their usage in a heat-producing mode during a non-heating season with a load of hot water supply. For this mode the dependence of the turbine heat efficiency on the heat load of the external consumer at a given throttle flow was analyzed.

Implementation strategy for small CHP-plants in a competitive market: the case of Lithuania

International Nuclear Information System (INIS)

Lund, H.; Siupsinskas, G.; Martinaitis, V.

2005-01-01

Within five years from now, Lithuania is going to close down Ignalina, the only nuclear-power plant in the country. Since Ignalina generates more than 75% of the Lithuanian electricity production, new generation capacities are needed. Traditional steam-turbines, fuelled with fossil fuels, would mean further imports of fuel as well as a rise in CO 2 emissions. At the same time, several small district-heating companies one suffering from high heating-prices. Typically, the price in small towns is 20-50% higher than the price in large urban areas. Consequently, alternative strategies should be considered. This article analyses the conditions for one such strategy, namely the replacement of boilers in the existing district-heating supplies with combined heat-and-power production (CHP). Compared with new power stations, fuel can be saved and CO 2 -emissions reduced. Also this strategy can be used to level the difference between low heating prices in the large urban areas and high prices in small towns and villages. (Author)

Testing and model-aided analysis of a 2 kW el PEMFC CHP-system

Science.gov (United States)

König, P.; Weber, A.; Lewald, N.; Aicher, T.; Jörissen, L.; Ivers-Tiffée, E.; Szolak, R.; Brendel, M.; Kaczerowski, J.

A prototype PEMFC CHP-system (combined heat and power) for decentralised energy supply in domestic applications has been installed in the Fuel Cell Testing Laboratory at the Institut für Werkstoffe der Elektrotechnik (IWE), Universität Karlsruhe (TH). The system, which was developed at the Zentrum für Sonnenenergie- und Wasserstoff-Forschung ZSW, Ulm (FC-stack) and the Fraunhofer-Institut für Solare Energiesysteme ISE, Freiburg (reformer) is operated and tested in close cooperation with the Stadtwerke Karlsruhe. The tests are carried out as part of the strategic project EDISon, which is supported by the German Federal Ministry of Economics and Technology (BMWA). The performance of the system is evaluated for different operating conditions. The tests include steady state measurements under different electrical and thermal loads as well as an analysis of the dynamic behaviour of the system during load changes. First results of these steady state and dynamic operation characteristics will be presented in this paper.

A study on the optimal replacement periods of digital control computer's components of Wolsung nuclear power plant unit 1

International Nuclear Information System (INIS)

Mok, Jin Il; Seong, Poong Hyun

1993-01-01

Due to the failure of the instrument and control devices of nuclear power plants caused by aging, nuclear power plants occasionally trip. Even a trip of a single nuclear power plant (NPP) causes an extravagant economical loss and deteriorates public acceptance of nuclear power plants. Therefore, the replacement of the instrument and control devices with proper consideration of the aging effect is necessary in order to prevent the inadvertent trip. In this paper we investigated the optimal replacement periods of the control computer's components of Wolsung nuclear power plant Unit 1. We first derived mathematical models of optimal replacement periods to the digital control computer's components of Wolsung NPP Unit 1 and calculated the optimal replacement periods analytically. We compared the periods with the replacement periods currently used at Wolsung NPP Unit 1. The periods used at Wolsung is not based on mathematical analysis, but on empirical knowledge. As a consequence, the optimal replacement periods analytically obtained and those used in the field show a little difference. (Author)

GA/particle swarm intelligence based optimization of two specific varieties of controller devices applied to two-area multi-units automatic generation control

Energy Technology Data Exchange (ETDEWEB)

Bhatt, Praghnesh [Department of Electrical Engineering, Charotar Institute of Technology, Changa 388 421, Gujarat (India); Roy, Ranjit [Department of Electrical Engineering, S.V. National Institute of Technology, Surat 395 007, Gujarat (India); Ghoshal, S.P. [Department of Electrical Engineering, National Institute of Technology, Durgapur 713 209, West Bengal (India)

2010-05-15

This paper presents the comparative performance analysis of the two specific varieties of controller devices for optimal transient performance of automatic generation control (AGC) of an interconnected two-area power system, having multiple thermal-hydro-diesels mixed generating units. The significant improvement of optimal transient performance is observed with the addition of a thyristor-controlled phase shifter (TCPS) in the tie-line or capacitive energy storage (CES) units fitted in both the areas. Three different optimization algorithms are adopted for the sake of comparison of optimal performances and obtaining the optimal values of the gain settings of the devices independently. Craziness based particle swarm optimization (CRPSO) proves to be moderately fast algorithm and yields true optimal gains and minimum overshoot, minimum undershoot and minimum settling time of the transient response for any system. Comparative studies of TCPS and CES by any algorithm reveals that the CES units fitted in both the areas improve the transient performance to a greater extent following small load disturbance(s) in both the areas. (author)

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Andersen, Palle

1998-01-01

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has...... tests on a 265 MW coal-fired power-plant unit reveals that the maximum allowable load gradient that can be imposed on the plant, can be increased from 4 MW/min. to 8 MW/min....

A general technoeconomic and environmental procedure for assessment of small-scale cogeneration scheme installations: Application to a local industry operating in Thrace, Greece, using microturbines

International Nuclear Information System (INIS)

Katsigiannis, P.A.; Papadopoulos, D.P.

2005-01-01

The present paper describes a proposed general systematic procedure for small-scale combined heat and power (CHP) exploitation (where 'small-scale CHP' refers to CHP installations with electric capacities up to 1 MW). The mentioned systematic procedure is implemented through a developed computer code and may be applied to any such small-scale project in order to assess its suitability based on technoeconomic and environmental considerations. A dynamic database based on small-scale CHP units (available in the world market) and their pertinent technical, economical and environmental features is created and, in conjunction with the developed program, is used for determination of a suitable CHP unit (or system) size and the selection of the associated proper prime mover type for any project of interest. Using well-known economic criteria, the economic analysis is performed, including the sensitivity analysis of the considered project based on the main key system parameters. In terms of the socioeconomic analysis, a carbon tax (CT) scenario is considered, and its effect on the economic behavior of the project is investigated. Last, with respect to environmental considerations, the program calculates, for any such project, the avoided main pollutants and the fuel savings when a CHP system is applied. As a case study, a small textile industry operating in the Eastern Macedonia-Thrace Region of Greece is considered, and its associated (electrical and thermal) data are used as input data to the proposed computer program. In this application, two microturbine units are selected and thoroughly evaluated, and the pertinent simulation results are presented and discussed accordingly

Design and analysis of permanent magnet moving coil type generator used in a micro-CHP generation system

Science.gov (United States)

Oros Pop, Susana Teodora; Berinde, Ioan; Vadan, Ioan

2015-12-01

This paper presents the design and analysis of a permanent magnet moving coil type generator driven by a free piston Stirling engine. This assemble free piston Stirling engine - permanent magnet moving coil type generator will be used in a combined heat and power (CHP) system for producing heat and power in residential area. The design procedure for moving coil type linear generator starts from the rated power imposed and finally uses the Faraday law of induction. The magneto-static magnetic field generated by permanent magnets is analyzed by means of Reluctance method and Finite Element Method in order to evaluate the magnetic flux density in the air gap, which is a design data imposed in the design stage, and the results are compared.

Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

Science.gov (United States)

Zhang, Yifei; Kang, Jian

2017-11-01

The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

Optimization of the coherence function estimation for multi-core central processing unit

Science.gov (United States)

Cheremnov, A. G.; Faerman, V. A.; Avramchuk, V. S.

2017-02-01

The paper considers use of parallel processing on multi-core central processing unit for optimization of the coherence function evaluation arising in digital signal processing. Coherence function along with other methods of spectral analysis is commonly used for vibration diagnosis of rotating machinery and its particular nodes. An algorithm is given for the function evaluation for signals represented with digital samples. The algorithm is analyzed for its software implementation and computational problems. Optimization measures are described, including algorithmic, architecture and compiler optimization, their results are assessed for multi-core processors from different manufacturers. Thus, speeding-up of the parallel execution with respect to sequential execution was studied and results are presented for Intel Core i7-4720HQ и AMD FX-9590 processors. The results show comparatively high efficiency of the optimization measures taken. In particular, acceleration indicators and average CPU utilization have been significantly improved, showing high degree of parallelism of the constructed calculating functions. The developed software underwent state registration and will be used as a part of a software and hardware solution for rotating machinery fault diagnosis and pipeline leak location with acoustic correlation method.

Optimizing gas extraction at landfills in Denmark; Optimering af gasindvinding pae deponeringsanlaeg i Danmark

Energy Technology Data Exchange (ETDEWEB)

Willumsen, H.C. [LFG Consult (Denmark)

2005-07-01

In landfills which contain organic material and anaerobic decomposition takes place, and landfill gas (LFG) is produced. The LFG contains approximately 50% methane, which contributes to the greenhouse effect when emitting from the landfill. Approximately 19% of the greenhouse gases in the atmosphere are methane, and around 8% of this is emission from landfills. This means that roughly 1.5% of the global warming is related to emission from landfills. Extraction of LFG for energy purposes was started 30 years ago in USA. In Denmark 26 LFG plants have been established since 1985. The gas is utilized for CHP or pure power production in gas engine/generator units. In some cases the LFG is used in gas burners in connection with boilers for district heating systems. 24 million m{sup 3} was recovered in 2004, which is equivalent to a reduction of CO{sub 2} of 160.000 tons CO{sub 2}/year. (BA)

Optimal Residential Load Scheduling Under Utility and Rooftop Photovoltaic Units

Directory of Open Access Journals (Sweden)

Ghulam Hafeez

2018-03-01

Full Text Available With the rapid advancement in technology, electrical energy consumption is increasing rapidly. Especially, in the residential sector, more than 80% of electrical energy is being consumed because of consumer negligence. This brings the challenging task of maintaining the balance between the demand and supply of electric power. In this paper, we focus on the problem of load balancing via load scheduling under utility and rooftop photovoltaic (PV units to reduce electricity cost and peak to average ratio (PAR in demand-side management. For this purpose, we adopted genetic algorithm (GA, binary particle swarm optimization (BPSO, wind-driven optimization (WDO, and our proposed genetic WDO (GWDO algorithm, which is a hybrid of GA and WDO, to schedule the household load. For energy cost estimation, combined real-time pricing (RTP and inclined block rate (IBR were used. The proposed algorithm shifts load from peak consumption hours to off-peak hours based on combined pricing scheme and generation from rooftop PV units. Simulation results validate our proposed GWDO algorithm in terms of electricity cost and PAR reduction while considering all three scenarios which we have considered in this work: (1 load scheduling without renewable energy sources (RESs and energy storage system (ESS, (2 load scheduling with RESs, and (3 load scheduling with RESs and ESS. Furthermore, our proposed scheme reduced electricity cost and PAR by 22.5% and 29.1% in scenario 1, 47.7% and 30% in scenario 2, and 49.2% and 35.4% in scenario 3, respectively, as compared to unscheduled electricity consumption.

Optimization models of the supply of power structures’ organizational units with centralized procurement

Directory of Open Access Journals (Sweden)

Sysoiev Volodymyr

2013-01-01

Full Text Available Management of the state power structures’ organizational units for materiel and technical support requires the use of effective tools for supporting decisions, due to the complexity, interdependence, and dynamism of supply in the market economy. The corporate nature of power structures is of particular interest to centralized procurement management, as it provides significant advantages through coordination, eliminating duplication, and economy of scale. This article presents optimization models of the supply of state power structures’ organizational units with centralized procurement, for different levels of simulated materiel and technical support processes. The models allow us to find the most profitable options for state power structures’ organizational supply units in a centre-oriented logistics system in conditions of the changing needs, volume of allocated funds, and logistics costs that accompany the process of supply, by maximizing the provision level of organizational units with necessary material and technical resources for the entire planning period of supply by minimizing the total logistical costs, taking into account the diverse nature and the different priorities of organizational units and material and technical resources.

Optimal selection of Orbital Replacement Unit on-orbit spares - A Space Station system availability model

Science.gov (United States)

Schwaab, Douglas G.

1991-01-01

A mathematical programing model is presented to optimize the selection of Orbital Replacement Unit on-orbit spares for the Space Station. The model maximizes system availability under the constraints of logistics resupply-cargo weight and volume allocations.

Three-dimensional reconstruction of statistically optimal unit cells of polydisperse particulate composites from microtomography

International Nuclear Information System (INIS)

Lee, H.; Brandyberry, M.; Tudor, A.; Matous, K.

2009-01-01

In this paper, we present a systematic approach for characterization and reconstruction of statistically optimal representative unit cells of polydisperse particulate composites. Microtomography is used to gather rich three-dimensional data of a packed glass bead system. First-, second-, and third-order probability functions are used to characterize the morphology of the material, and the parallel augmented simulated annealing algorithm is employed for reconstruction of the statistically equivalent medium. Both the fully resolved probability spectrum and the geometrically exact particle shapes are considered in this study, rendering the optimization problem multidimensional with a highly complex objective function. A ten-phase particulate composite composed of packed glass beads in a cylindrical specimen is investigated, and a unit cell is reconstructed on massively parallel computers. Further, rigorous error analysis of the statistical descriptors (probability functions) is presented and a detailed comparison between statistics of the voxel-derived pack and the representative cell is made.

Mathematical model for optimization of multilayer submerged-arc welding of frame equipment of power units

International Nuclear Information System (INIS)

Pankov, V.V.; Chernyshev, G.G.; Kozlov, N.E.

1987-01-01

A mathematical model for optimization of multilayer submerged arc welding of frame equipment of power units is constructed. The variation-energy method permits to construct the universal mathematical model for strengthening formation of a single bead; the method is reasonable for simulation of a multilayer welded joint. Minimization of the distance between maximum and minimum layer height of a built-up metal is the necessary condition for qualitative formation of the multilayer joint. One can calculate in real time scale the optimal vector of maximally ten parameters under the multilayer welding condition immediately after change in the grooving width using the developed mathematical model of optimization

Optimal replacement and inspection periods of safety and control boards in Wolsung nuclear power plant unit 1

International Nuclear Information System (INIS)

Mok, Jin Il

1993-02-01

In nuclear power plants, the safety and control systems are important for operating and maintaining safety of nuclear power plants. Due to the failure of the instrument and control devices of nuclear power plants caused by aging, nuclear power plants occasionally trip. Since the start of first commercial operation of Kori nuclear power plant (NPP) unit 1, the trips caused by instrument and control systems account for 28% of total trips of NPPs in Korea. Even a single trip of a nuclear power plant causes an extravagant economical loss and deteriorates public acceptance of nuclear power plants. Therefore, the replacement of the instrument and control devices with proper consideration of the aging effect is necessary in order to prevent the inadvertent trip. In this work we investigated the optimal replacement periods of the digital control computer's (DCC) and the programmable digital comparator's (PDC) electronic circuit boards of Wolsung nuclear power plant Unit 1. We first derived mathematical models which calculate optimal replacement periods for electronic circuit boards of digital control computer (DCC) and for those of the programmable digital comparator (PDC) in Wolsung NPP unit 1. And we analytically obtained the optimal replacement periods of electronic circuit boards by using these models. We compared these periods with the replacement periods currently used at Wolsung NPP Unit. The periods used at Wolsung is not based on mathematical analysis, but on empirical knowledge. As a consequence, the optimal replacement periods analytically obtained for the electronic circuit boards of DCC and those used in the field shown small difference : the optimal replacement periods analytically obtained for the electronic circuit boards of PDC are shorter than those used in the field in general. The engineered safeguards of Wolsung nuclear power plant unit 1 contains redundant systems of 2-out-of-3 logic which are not operating under normal conditions but they are called

Strandby Harbour on solar cooling. Demonstration of 8.000 m{sup 2} solar collectors combined with flue gas cooling with a absorption cooling system; Combined heat and power plant (CHP); Strandby havn paa solkoeling. Demonstration af 8.000 m{sup 2} solfangere kombineret med roeggaskoeling med absorptionskoeleanlaeg

Energy Technology Data Exchange (ETDEWEB)

Soerensen, Flemming (Strandby Varmevaerk, Strandby (Denmark)); Soerensen, Per Alex (PlanEnergi, Skoerping (Denmark)); Ulbjerg, F. (Ramboell, Odense (Denmark)); Sloth, H. (Houe and Olsen, Thisted (Denmark))

2010-04-15

The aim of the project was to demonstrate 1) high solar heating ratio (18% annually) at a decentralized natural gas combined heat and power plant; 2) increased efficiency (5% of the heat consumption) in a natural gas CHP by using an extra flue gas cooler and an absorption heat pump; 3) a double tank system where a new tank during winter is used for cooling/ heat storage for the absorption heat pump and during summer for solar heat storage in serial operation with the old tank. The concept of combining solar power, absorption cooling and natural gas-fired small-scale CHP in Strandby met expectations and could be replicated in other CHP plants. However, it is important to note that if major construction modifications in the flue gas condensation system in the boiler or engine are required, the operating hours must not be reduced significantly in the amortisation period for the conversion. (ln)

Nonlinear dynamic simulation of optimal depletion of crude oil in the lower 48 United States

International Nuclear Information System (INIS)

Ruth, M.; Cleveland, C.J.

1993-01-01

This study combines the economic theory of optimal resource use with econometric estimates of demand and supply parameters to develop a nonlinear dynamic model of crude oil exploration, development, and production in the lower 48 United States. The model is simulated with the graphical programming language STELLA, for the years 1985 to 2020. The procedure encourages use of economic theory and econometrics in combination with nonlinear dynamic simulation to enhance our understanding of complex interactions present in models of optimal resource use. (author)

The role of policy instruments for promoting combined heat and power production with low CO2 emissions in district heating systems

International Nuclear Information System (INIS)

Marbe, A.; Harvey, S.

2005-01-01

Policy instruments clearly influence the choice of production technologies and fuels in large energy systems, including district heating networks. Current Swedish policy instruments aim at promoting the use of biofuel in district heating systems, and at promoting electric power generation from renewable energy sources. However, there is increasing pressure to harmonize energy policy instruments within the EU. In addition, natural gas based combined cycle technology has emerged as the technology of choice in the power generation sector in the EU. This study aims at exploring the role of policy instruments for promoting the use of low CO 2 emissions fuels in high performance combined heat and power systems in the district heating sector. The paper presents the results of a case study for a Swedish district heating network where new large size natural gas combined cycle (NGCC) combined heat and power (CHP) is being built. Given the aim of current Swedish energy policy, it is assumed that it could be of interest in the future to integrate a biofuel gasifier to the CHP plant and co-fire the gasified biofuel in the gas turbine unit, thereby reducing usage of fossil fuel. The goals of the study are to evaluate which policy instruments promote construction of the planned NGCC CHP unit, the technical performance of an integrated biofuelled pressurized gasifier with or without dryer on plant site, and which combination of policy instruments promote integration of a biofuel gasifier to the planned CHP unit. The power plant simulation program GateCycle was used for plant performance evaluation. The results show that current Swedish energy policy instruments favour investing in the NGCC CHP unit. The corresponding cost of electricity (COE) from the NGCC CHP unit is estimated at 253 SEK MWh -1 , which is lower than the reference power price of 284 SEK MWh -1 . Investing in the NGCC CHP unit is also shown to be attractive if a CO 2 trading system is implemented. If the value of

Development of a biorefinery optimized biofuel supply curve for the Western United States

International Nuclear Information System (INIS)

Parker, Nathan; Tittmann, Peter; Hart, Quinn; Nelson, Richard; Skog, Ken; Schmidt, Anneliese; Gray, Edward; Jenkins, Bryan

2010-01-01

A resource assessment and biorefinery siting optimization model was developed and implemented to assess potential biofuel supply across the Western United States from agricultural, forest, urban, and energy crop biomass. Spatial information including feedstock resources, existing and potential refinery locations and a transportation network model is provided to a mixed integer-linear optimization model that determines the optimal locations, technology types and sizes of biorefineries to satisfy a maximum profit objective function applied across the biofuel supply and demand chain from site of feedstock production to the product fuel terminal. The resource basis includes preliminary considerations of crop and residue sustainability. Sensitivity analyses explore possible effects of policy and technology changes. At a target market price of 19.6 $ GJ -1 , the model predicts a feasible production level of 610-1098 PJ, enough to supply up to 15% of current regional liquid transportation fuel demand. (author)

Automatic delineation of geomorphological slope units with r.slopeunits v1.0 and their optimization for landslide susceptibility modeling

Directory of Open Access Journals (Sweden)

M. Alvioli

2016-11-01

Full Text Available Automatic subdivision of landscapes into terrain units remains a challenge. Slope units are terrain units bounded by drainage and divide lines, but their use in hydrological and geomorphological studies is limited because of the lack of reliable software for their automatic delineation. We present the r.slopeunits software for the automatic delineation of slope units, given a digital elevation model and a few input parameters. We further propose an approach for the selection of optimal parameters controlling the terrain subdivision for landslide susceptibility modeling. We tested the software and the optimization approach in central Italy, where terrain, landslide, and geo-environmental information was available. The software was capable of capturing the variability of the landscape and partitioning the study area into slope units suited for landslide susceptibility modeling and zonation. We expect r.slopeunits to be used in different physiographical settings for the production of reliable and reproducible landslide susceptibility zonations.

Integrated HT-PEMFC and multi-fuel reformer for micro CHP. Final report

Energy Technology Data Exchange (ETDEWEB)

2010-07-01

The project was initiated in April 2008 and completed by the end of March 2010. The project consortium consisted of: Dantherm Power, Serenergy and Department of Energy Technology at Aalborg University (project manager). The activities were coordinated with the project ''Nordjysk H2FC Center'' funded by the Region of Northern Jutland. A number of experimental characterization methods were developed through this project to improve the understanding in fuel cell performance under different operating conditions. In particular the application of Electrochemical Impedance Spectroscopy was found useful and lead to new information about individual losses in the fuel cell. Techniques to measure local temperatures of the MEA were also successfully developed. Durability studies were made on single cells as well as complete stacks. A dedicated test facility was constructed in a container to isolate the test from disturbances that occur in the laboratory. The stack tests were run for just above 6 months with few interruptions and it was found that single cell and stack degradation rates were comparable. Operation temperature was found to have the most pronounced influence on degradation. The information formed the basis for a simple modeling tool to optimize the stack operating temperature versus reformate gas CO concentration. The activities on multi-fuel reformer development were mostly focused on two issues; manufacturability and analyses of flow distribution and heat transfer. The latter was required since these areas these turned out to cause challenges in the reactor design. Through a combination of experimental tests, CFD analyses and flow network modeling design modifications were suggested to improve flow distribution on both the flue gas side and the reformate side. Most of these design changes were not validated in this project through the construction and test of a new reformer. In spite of the problems identifies, the reformed successfully

Feed-forward control of a solid oxide fuel cell system with anode offgas recycle

Science.gov (United States)

Carré, Maxime; Brandenburger, Ralf; Friede, Wolfgang; Lapicque, François; Limbeck, Uwe; da Silva, Pedro

2015-05-01

In this work a combined heat and power unit (CHP unit) based on the solid oxide fuel cell (SOFC) technology is analysed. This unit has a special feature: the anode offgas is partially recycled to the anode inlet. Thus it is possible to increase the electrical efficiency and the system can be operated without external water feeding. A feed-forward control concept which allows secure operating conditions of the CHP unit as well as a maximization of its electrical efficiency is introduced and validated experimentally. The control algorithm requires a limited number of measurement values and few deterministic relations for its description.

Trial operation of a phosphoric acid fuel cell (PC25) for CHP applications in Europe

Energy Technology Data Exchange (ETDEWEB)

Uhrig, M.; Droste, W.; Wolf, D. [Ruhrgas AG, Dorsten (Germany)

1996-12-31

In Europe, ten 200 kW phosphoric acid fuel cells (PAFCs) produced by ONSI (PC25) are currently in operation. Their operators collaborate closely in the European Fuel Cell Users Group (EFCUG). The experience gained from trial operation by the four German operators - HEAG, HGW/HEW, Thyssengas and Ruhrgas - coincides with that of the other European operators. This experience can generally be regarded as favourable. With a view to using fuel cells in combined heat and power generation (CHP), the project described in this report, which was carried out in cooperation with the municipal utility of Bochum and Gasunie of the Netherlands, aimed at gaining experience with the PC 25 in field operation under the specific operating conditions prevailing in Europe. The work packages included heat-controlled operation, examination of plant behavior with varying gas properties and measurement of emissions under dynamic load conditions. The project received EU funding under the JOULE programme.

Projected configuration of a coal-fired district heating source on the basis of comparative technical-economical optimization analysis

Directory of Open Access Journals (Sweden)

Tańczuk Mariusz

2017-01-01

Full Text Available District heating technologies should be efficient, effective and environmentally friendly. The majority of the communal heating systems in Poland produce district hot water in coal-fired boilers. A large number of them are considerably worn out, low-efficient in the summer time and will not comply with forthcoming regulations. One of the possible solution for such plants is repowering with new CHP systems or new boilers fuelled with fuels alternative to coal. Optimisation analysis of the target configuration of municipal heat generating plant is analysed in the paper. The work concerns repowering the existing conventional heat generating plant according to eight different scenarios of the plant configuration meeting technical and environmental requirements forecasted for the year of 2035. The maximum demand for heat of the system supplied by the plant is 185 MW. Taking into account different technical configurations on one side, and different energy and fuel prices on the other side, the comparative cost-benefits analysis of the assumed scenarios has been made. The basic economical index NPV (net present value has been derived for each analysed scenario and the results have been compared and discussed. It was also claimed that the scenario with CHP based on ICE engines is optimal.

Projected configuration of a coal-fired district heating source on the basis of comparative technical-economical optimization analysis

Science.gov (United States)

Tańczuk, Mariusz; Radziewicz, Wojciech; Olszewski, Eligiusz; Skorek, Janusz

2017-10-01

District heating technologies should be efficient, effective and environmentally friendly. The majority of the communal heating systems in Poland produce district hot water in coal-fired boilers. A large number of them are considerably worn out, low-efficient in the summer time and will not comply with forthcoming regulations. One of the possible solution for such plants is repowering with new CHP systems or new boilers fuelled with fuels alternative to coal. Optimisation analysis of the target configuration of municipal heat generating plant is analysed in the paper. The work concerns repowering the existing conventional heat generating plant according to eight different scenarios of the plant configuration meeting technical and environmental requirements forecasted for the year of 2035. The maximum demand for heat of the system supplied by the plant is 185 MW. Taking into account different technical configurations on one side, and different energy and fuel prices on the other side, the comparative cost-benefits analysis of the assumed scenarios has been made. The basic economical index NPV (net present value) has been derived for each analysed scenario and the results have been compared and discussed. It was also claimed that the scenario with CHP based on ICE engines is optimal.

Optimal coordinated scheduling of combined heat and power fuel cell, wind, and photovoltaic units in micro grids considering uncertainties

International Nuclear Information System (INIS)

Bornapour, Mosayeb; Hooshmand, Rahmat-Allah; Khodabakhshian, Amin; Parastegari, Moein

2016-01-01

In this paper, a stochastic model is proposed for coordinated scheduling of combined heat and power units in micro grid considering wind turbine and photovoltaic units. Uncertainties of electrical market price; the speed of wind and solar radiation are considered using a scenario-based method. In the method, scenarios are generated using roulette wheel mechanism based on probability distribution functions of input random variables. Using this method, the probabilistic specifics of the problem are distributed and the problem is converted to a deterministic one. The type of the objective function, coordinated scheduling of combined heat and power, wind turbine, and photovoltaic units change this problem to a mixed integer nonlinear one. Therefore to solve this problem modified particle swarm optimization algorithm is employed. The mentioned uncertainties lead to an increase in profit. Moreover, the optimal coordinated scheduling of renewable energy resources and thermal units in micro grids increase the total profit. In order to evaluate the performance of the proposed method, its performance is executed on modified 33 bus distributed system as a micro grid. - Highlights: • Stochastic model is proposed for coordinated scheduling of renewable energy sources. • The effect of combined heat and power is considered. • Maximizing profits of micro grid is considered as objective function. • Considering the uncertainties of problem lead to profit increasing. • Optimal scheduling of renewable energy sources and thermal units increases profit.

Efficiency-optimized low-cost TDPAC spectrometer using a versatile routing/coincidence unit

International Nuclear Information System (INIS)

Renteria, M.; Bibiloni, A. G.; Darriba, G. N.; Errico, L. A.; Munoz, E. L.; Richard, D.; Runco, J.

2008-01-01

A highly efficient, reliable, and low-cost γ-γ TDPAC spectrometer, PACAr, optimized for 181 Hf-implanted low-activity samples, is presented. A versatile EPROM-based routing/coincidence unit was developed and implemented to be use with the memory-card-based multichannel analyzer hosted in a personal computer. The excellent energy resolution and very good overall resolution and efficiency of PACAr are analyzed and compare with advanced and already tested fast-fast and slow-fast PAC spectrometers.

Efficiency-optimized low-cost TDPAC spectrometer using a versatile routing/coincidence unit

Energy Technology Data Exchange (ETDEWEB)

Renteria, M., E-mail: renteria@fisica.unlp.edu.ar; Bibiloni, A. G.; Darriba, G. N.; Errico, L. A.; Munoz, E. L.; Richard, D.; Runco, J. [Universidad Nacional de La Plata, Departamento de Fisica, Facultad de Ciencias Exactas (Argentina)

2008-01-15

A highly efficient, reliable, and low-cost {gamma}-{gamma} TDPAC spectrometer, PACAr, optimized for {sup 181}Hf-implanted low-activity samples, is presented. A versatile EPROM-based routing/coincidence unit was developed and implemented to be use with the memory-card-based multichannel analyzer hosted in a personal computer. The excellent energy resolution and very good overall resolution and efficiency of PACAr are analyzed and compare with advanced and already tested fast-fast and slow-fast PAC spectrometers.

Stochastic Programming for Fuel Supply Planning of Combined Heat and Power Plants

DEFF Research Database (Denmark)

Guericke, Daniela; Blanco, Ignacio; Morales González, Juan Miguel

The consumption of biomass to produce power and heat has increased due to the carbon neutral policies. Combined heat and power (CHP) plants often combine biomass with other fuels, e.g., natural gas. The negotiation process for supply contracts involves many uncertainties due to the long planning...... horizon. The demand for biomass is uncertain, and heat demand and electricity prices vary during the planning period. We propose a method using stochastic optimization to support the biomass and natural gas supply planning for CHP plants including short-term decisions for optimal market participation....

Unit Commitment Towards Decarbonized Network Facing Fixed and Stochastic Resources Applying Water Cycle Optimization

Directory of Open Access Journals (Sweden)

Heba-Allah I. ElAzab

2018-05-01

Full Text Available This paper presents a trustworthy unit commitment study to schedule both Renewable Energy Resources (RERs with conventional power plants to potentially decarbonize the electrical network. The study has employed a system with three IEEE thermal (coal-fired power plants as dispatchable distributed generators, one wind plant, one solar plant as stochastic distributed generators, and Plug-in Electric Vehicles (PEVs which can work either loads or generators based on their charging schedule. This paper investigates the unit commitment scheduling objective to minimize the Combined Economic Emission Dispatch (CEED. To reduce combined emission costs, integrating more renewable energy resources (RER and PEVs, there is an essential need to decarbonize the existing system. Decarbonizing the system means reducing the percentage of CO2 emissions. The uncertain behavior of wind and solar energies causes imbalance penalty costs. PEVs are proposed to overcome the intermittent nature of wind and solar energies. It is important to optimally integrate and schedule stochastic resources including the wind and solar energies, and PEVs charge and discharge processes with dispatched resources; the three IEEE thermal (coal-fired power plants. The Water Cycle Optimization Algorithm (WCOA is an efficient and intelligent meta-heuristic technique employed to solve the economically emission dispatch problem for both scheduling dispatchable and stochastic resources. The goal of this study is to obtain the solution for unit commitment to minimize the combined cost function including CO2 emission costs applying the Water Cycle Optimization Algorithm (WCOA. To validate the WCOA technique, the results are compared with the results obtained from applying the Dynamic Programming (DP algorithm, which is considered as a conventional numerical technique, and with the Genetic Algorithm (GA as a meta-heuristic technique.

Combined use of solar heat and cogeneration - a perspective for district heating?; Kombinierter Einsatz von solarer Waerme und Kraft-Waerme-Kopplung - eine Perspektive fuer die Nahwaerme?

Energy Technology Data Exchange (ETDEWEB)

Entress, J. [Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), Stuttgart (Germany). Abt. Systemanalyse und Technikbewertung; Steinborn, F. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung Baden-Wuerttemberg (ZSW), Stuttgart (Germany). Fachgebiet Systemanalyse

1998-02-01

With Cogeneration of Heat and Power (CHP), climate-endangering CO{sub 2}-emissions can be reduced singificantly. The heat produced can be delivered at prices comparable to those of conventionally produced heat. With solar district heating, yet higher CO{sub 2}-savings are possible but at higher cost. Promising is a combination of CHP and solar district heating: The heat storage of the solar system can be used to level out heat demand, leading to smooth CHP operation, while heat generated by CHP can be used to substitute for low irradiation during the winter period. However, calculations together with simulation and optimization indicate that combining CHP and solar district heating is not the optimal solution in all cases. (orig.) [Deutsch] Der Einsatz von Blockheizkraftwerken (BHKW) kann zu einer deutlichen Reduzierung der klimagefaehrdenden CO{sub 2}-Emissionen beitragen. Dabei kann die ausgekoppelte Waerme etwa zum gleichen Preis wie konventionell erzeugte Waerme abgegeben werden. Hoehere CO{sub 2}-Einsparungen lassen sich hingegen mit solarer Nahwaerme erzielen, allerdings zu hoeheren Kosten. Eine Kombination dieser beiden Waermetechniken verspricht Vorteile: Einerseits kann der Waermespeicher des Solarsystems auch zum Ausgleich von Lastspitzen beim Betrieb des BHKW`s genutzt werden. Andererseits kann die waehrend der einstrahlungsarmen Wintermonate fehlende solare Waerme durch das BHKW erzeugt werden. Detaillierte Simulations- und Optimierungsrechnungen zeigen jedoch, dass eine Kombination dieser Waermetechniken nicht immer empfehlenswert ist. (orig.)

A new methodology for greenhouse gas reduction in industry through improved heat exchanging and/or integration of combined heat and power

International Nuclear Information System (INIS)

Axelsson, H.; Asblad, A.; Berntsson, T.

1999-01-01

This paper presents a method that identifies economically optimal combinations of enhanced heat recovery, integration of combined heat and power (CHP), and fuel switching, in an existing industrial energy system at various emission levels. Novel types of composite curves based on pinch technology, representing the existing temperature levels for supplying heat and the possible ones that may be attained after retrofitting, are used as tools for estimating the opportunities for CHP and the trade-off between improved heat exchanging and CHP. The method is explained by an example. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

The role of heat pump technologies in the design of future sustainable energy systems

DEFF Research Database (Denmark)

Blarke, Morten Boje; Lund, Henrik

2005-01-01

source results in an 8% cost reduction. Furthermore, the operational analysis shows that when a large-scale heat pump is integrated with an existing CHP unit, the projected spot market situation in Nord Pool, which reflects a growing share of wind power and heat-bound power generation electricity......In this paper, it is shown that in support of its ability to improve the overall economic cost-effectiveness and flexibility of the Danish energy system, the financially feasible integration of large-scale heat pumps with existing CHP units, is critically sensitive to the operational mode...... of the heat pump vis-à-vis the operational coefficient of performance (COP), which is set by the temperature level of the heat source. When using only ambient air as the heat source, the total heat production costs increases by about 10%, while the partial use of condensed flue gas from the CHP unit as a heat...

Optimal design of compact organic Rankine cycle units for domestic solar applications

DEFF Research Database (Denmark)

Barbazza, Luca; Pierobon, Leonardo; Mirandola, Alberto

2014-01-01

criteria, i.e., compactness, high performance and safe operation, are targeted by adopting a multi-objective optimization approach modeled with the genetic algorithm. Design-point thermodynamic variables, e.g., evaporating pressure, the working fluid, minimum allowable temperature differences......Organic Rankine cycle turbogenerators are a promising technology to transform the solar radiation harvested by solar collectors into electric power. The present work aims at sizing a small-scale organic Rankine cycle unit by tailoring its design for domestic solar applications. Stringent design...

Combined heat and power in Dutch greenhouses: A case study of technology diffusion

International Nuclear Information System (INIS)

Veen, Reinier A.C. van der; Kasmire, Julia

2015-01-01

This paper presents a case study of the rapid diffusion of combined heat and power (CHP) units through the Dutch greenhouse horticulture sector between 2003 and 2009 in order to gain new insights regarding technology transitions. We present a sectoral diffusion analysis framework, which we apply to identify and examine developments in technical, economic, institutional, cultural and ecological domains that all contributed to an emergent and thorough CHP diffusion in the Dutch greenhouse sector. Five identified key drivers behind the CHP diffusion are the opening of the energy market in 2002, the high spark spread during the transition period, the compatibility of output of a CHP unit with greenhouse demand, the flexibility provided by heat buffers, and the cooperative and competitive greenhouse sector culture. We conclude that policies to stimulate or steer technology diffusion will benefit from an in-depth analysis of domain interactions and company decision-making processes. Such an in-depth analysis makes for well informed and targeted policies that are better able to steer an industrial sector effectively and in a socially desired direction. - Highlights: • We present a sectoral diffusion analysis framework. • We describe the case of the diffusion of cogeneration (CHP) in Dutch greenhouses. • We extract five key drivers of CHP diffusion in the Dutch greenhouse sector. • The case shows how technology diffusion emerges from co-evolutionary mechanisms. • We conclude that a co-evolutionary sectoral analysis will inform innovation policy.

CHP biomass gasifier for the Zwarts Gerbera Nursery. Technical and economic feasibility; Biomassavergasser-WKK voor Gerberakwekerij Zwarts. Technische inpassing en economische haalbaarheid

Energy Technology Data Exchange (ETDEWEB)

Peeters, S.; Hart, A. [Energy Matters, Driebergen (Netherlands)

2011-10-15

This report describes the feasibility of a CHP gasifier at the Zwarts gerbera nursery. Using the insights from this study, a picture has been sketched for energy production by means of gasification in the horticultural sector. Note, however, that each plant specie has its own specific growth requirements in terms of nutrients, heating-cooling, light, but also relative humidity and CO2. So a 'typical' horticulturer with an 'average' energy requirement is hard to define. The economic viability must be determined for each individual situation. The outcomes of this study can therefore not be automatically used for other projects. Technically, a lot is possible, so the submitted quotes show. Of the 16 suppliers, 3 offer CHP gasifiers which, subject to conditions, not only burn wood but also other low-grade residual waste such as road verge grass, reed and miscanthus. This low-grade residual waste has the advantage of being cheaper than wood. A low biomass price lowers the operating costs and improves the economic profitability of the relatively expensive installations. The investment for a complete CHP gasifier is 5 to 10 times higher than for a normal gas CHP installation. The CO2 consumption also influences the economic profitability. Buying CO2 is a costly business. The technical and economic feasibility of harvesting CO2 from flue gas was therefore explored. Two CO2 harvesting installations (of Procede and Knook) were examined for this purpose. According to Procede and Knook, CO2 harvesting is not economically profitable for a CHP gasifier with a relatively low power capacity (up to 800 kWe). CO2 procurement or generation by means of the existing gas-fired boiler therefore seems more viable. The technical-economic feasibility study shows that an investment in a CHP gasifier is not profitable due to the relatively high investment and maintenance costs. CO2 demand and the uncertain biomass prices are stumbling blocks. However, the picture changes

Stochastic risk-constrained short-term scheduling of industrial cogeneration systems in the presence of demand response programs

International Nuclear Information System (INIS)

Alipour, Manijeh; Mohammadi-Ivatloo, Behnam; Zare, Kazem

2014-01-01

Highlights: • Short-term self-scheduling problem of customers with CHP units is conducted. • Power demand and pool prices are forecasted using ARIMA models. • Risk management problem is conducted by implementing CVaR methodology. • The demand response program is implemented in self-scheduling problem of CHP units. • Non-convex feasible operation region in different types of CHP units is modeled. - Abstract: This paper presents a stochastic programming framework for solving the scheduling problem faced by an industrial customer with cogeneration facilities, conventional power production system, and heat only units. The power and heat demands of the customer are supplied considering demand response (DR) programs. In the proposed DR program, the responsive load can vary in different time intervals. In the paper, the heat-power dual dependency characteristic in different types of CHP units is taken into account. In addition, a heat buffer tank, with the ability of heat storage, has been incorporated in the proposed framework. The impact of the market and load uncertainties on the scheduling problem is characterized through a stochastic programming formulation. Autoregressive integrated moving average (ARIMA) technique is used to generate the electricity price and the customer demand scenarios. The daily and weekly seasonalities of demand and market prices are taken into account in the scenario generation procedure. The conditional value-at-risk (CVaR) methodology is implemented in order to limit the risk of expected profit due to market price and load forecast volatilities

U.S. DOE Intermountain Clean Energy Application Center

Energy Technology Data Exchange (ETDEWEB)

Case, Patti [Etc Group, LLC, Salt Lake City, UT (United States)

2013-09-30

The Intermountain Clean Energy Application Center helped promote, assist, and transform the market for combined heat and power (CHP), including waste heat to power and district energy with CHP, in the intermountain states of Arizona, Colorado, New Mexico, Utah, and Wyoming. We accomplished these objectives through a combination of the following methods, which proved in concert to be a technically and economically effective strategy: o Identifying and facilitating high-impact CHP projects o Helping industrial, commercial, institutional, federal, and other large energy users in evaluating the economic and technical viability of potential CHP systems o Disseminating essential information about CHP including benefits, technologies, applications, project development, project financing, electric and gas utility incentives, and state policies o Coordinating and collaborating on CHP advancement with regional stakeholders including electric utilities, gas utilities, state energy offices, municipal development and planning personnel, trade associations, industry groups, non-profits, energy users, and others Outcomes of the project included increased understanding of and deployment of efficient and well-designed CHP systems in the states of Arizona, Colorado, New Mexico, Utah, and Wyoming. Increased CHP deployment helps the United States to enhance energy efficiency, strengthen the competitiveness of American industries, promote economic growth, foster a robust and resilient energy infrastructure, reduce emissions of air pollutants and greenhouse gases, and increase the use of market-ready advanced technologies. Specific outcomes included direct assistance to energy-intensive industrial facilities and other businesses, workshops and CHP tours, communication materials, and state policy education, all contributing to implementation of CHP systems in the intermountain region.

Cost related sensitivity analysis for optimal operation of a grid-parallel PEM fuel cell power plant

Science.gov (United States)

El-Sharkh, M. Y.; Tanrioven, M.; Rahman, A.; Alam, M. S.

Fuel cell power plants (FCPP) as a combined source of heat, power and hydrogen (CHP&H) can be considered as a potential option to supply both thermal and electrical loads. Hydrogen produced from the FCPP can be stored for future use of the FCPP or can be sold for profit. In such a system, tariff rates for purchasing or selling electricity, the fuel cost for the FCPP/thermal load, and hydrogen selling price are the main factors that affect the operational strategy. This paper presents a hybrid evolutionary programming and Hill-Climbing based approach to evaluate the impact of change of the above mentioned cost parameters on the optimal operational strategy of the FCPP. The optimal operational strategy of the FCPP for different tariffs is achieved through the estimation of the following: hourly generated power, the amount of thermal power recovered, power trade with the local grid, and the quantity of hydrogen that can be produced. Results show the importance of optimizing system cost parameters in order to minimize overall operating cost.

Lowering district heating temperatures – Impact to system performance in current and future Danish energy scenarios

DEFF Research Database (Denmark)

Ommen, Torben; Markussen, Wiebke Brix; Elmegaard, Brian

2016-01-01

CHP (Combined heat and power) production in connection with DH (district heating) systems has previously demonstrated a significant reduction in primary energy consumption. With extended installation of intermittent sustainable sources, such as eg. wind turbines rather than thermal units, the cha......CHP (Combined heat and power) production in connection with DH (district heating) systems has previously demonstrated a significant reduction in primary energy consumption. With extended installation of intermittent sustainable sources, such as eg. wind turbines rather than thermal units...

Unit Stratified Sampling as a Tool for Approximation of Stochastic Optimization Problems

Czech Academy of Sciences Publication Activity Database

Šmíd, Martin

2012-01-01

Roč. 19, č. 30 (2012), s. 153-169 ISSN 1212-074X R&D Projects: GA ČR GAP402/11/0150; GA ČR GAP402/10/0956; GA ČR GA402/09/0965 Institutional research plan: CEZ:AV0Z10750506 Institutional support: RVO:67985556 Keywords : Stochastic programming * approximation * stratified sampling Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2013/E/smid-unit stratified sampling as a tool for approximation of stochastic optimization problems.pdf

An innovative ORC power plant layout for heat and power generation from medium- to low-temperature geothermal resources

International Nuclear Information System (INIS)

Fiaschi, Daniele; Lifshitz, Adi; Manfrida, Giampaolo; Tempesti, Duccio

2014-01-01

Highlights: • Explotation of medium temperature geothermal resource with ORC–CHP is investigated. • A new CHP configuration to provide higher temperature to thermal user is proposed. • Several organic fluids and wide range of heat demand are studied. • The system produces higher power (almost 55%) in comparison to typical layouts. • Optimal working fluids vary with the characteristics of the heat demand. - Abstract: Medium temperature (up to 170 °C), water dominated geothermal resources are the most widespread in the world. The binary geothermal-ORC power plants are the most suitable energy conversion systems for this kind of resource. Specifically, combined heat and power (CHP) systems have the potential to improve the efficiency in exploiting the geothermal resources by cascading the geothermal fluid heat carrier to successively lower temperature users, thus increasing first and second law efficiency of the entire power plant. However, geothermal CHPs usually extract heat from the geofluid either in parallel or in series to the ORC, and usually provide only low temperature heat, which is seldom suitable for industrial use. In this paper, a new CHP configuration, called Cross Parallel CHP, has been proposed and analyzed. It aims to provide higher temperature heat suitable for industrial use, allowing the exploitation of geothermal resources even in areas where district heating is not needed. The proposed CHP allows the reduction of the irreversibilities in the heat exchangers and the loss to the environment related to the re-injection of geofluid, thus producing higher electric power output while satisfying, at the same time, the heat demand of the thermal utility for a wide range of temperatures and mass flow rates (80–140 °C; 3–13 kg/s). Several organic fluids are investigated and the related optimizing working conditions are found by a built in procedure making use of genetic algorithms. The results show that the optimal working fluids and

Technical-Economic Evaluation of a Cogeneration Unit Considering Carbon Emission Savings

Directory of Open Access Journals (Sweden)

Ana Christina Ferreira

2014-06-01

Full Text Available The support of combined heat and power production systems has gained policy attention, because these are often considered to be less polluting and more efficient than conventional energy conversion systems. As a consequence, the potential market for these energy systems that contribute to reduce greenhouse gas emissions and to enhance energy security on a national level, is shifting from large-scale existing units to small and micro-size emerging technologies. This paper presents a numerical model based on a cost-benefit analysis used to design an optimal cogeneration system for a small-scale building application, considering the Portuguese context and the comparison with the harmonized efficiency reference values for the separate production of electricity and useful heat. The model includes the identification of the objective function terms (i.e., the elements involved in the financial analysis across the system lifetime and the economic evaluation of costs and benefits of the combined heat and power production system. The economic viability of cogeneration systems significantly depends on system technology, client energy requirements and support schemes implemented in the respective countries. A strategic approach is necessary to adequately embed the new technology as a feasible solution in terms of investment and operational costs. Only by matching the energy supply to the needs and expectations of the energy users, it will be possible to improve the market competitiveness of these alternative power production plants. The optimal solution disclosed a positive annual worth, which is higher if the carbon emission savings are monetized. In addition, the optimal system represents a more efficient way to produce useful heat and electricity (i.e. a positive primary energy saving and to reduce gas emissions. A cost-benefit analysis can be applied for the techno-economic evaluation of a CHP system by assessing the monetary socio-environmental costs

Modelling the adoption of industrial cogeneration in Japan using manufacturing plant survey data

International Nuclear Information System (INIS)

Bonilla, David; Akisawa, Atsushi; Kashiwagi, Takao

2003-01-01

Electric power deregulation in Japan opens opportunity for further penetration of on-site generation (cogeneration) otherwise known as distributed generation. In the paper the authors present a survey on Japanese industrial plants to fill existing gaps for the assessment of modern cogeneration (combined heat and power, CHP). The objective of the paper is to empirically examine CHP systems based on cross-sectional binary models; second to review diffusion trends of CHP by system vintage during the 1980-2000 period in the manufacturing sector. The econometric results point that the probabilities of embracing this technology increase, in declining importance, with on-site power consumption, and steam demand, operational hours as well as with payback period, purchased power. For example the survey shows that the CHP is used for the purpose of exporting power rather than meeting the plant's own consumption. Some of our results are in line with those of Dismukes and Kleit (Resource Energy Econ. 21 (1999) 153) as well with Rose and Macdonald (Energy J. 12(12) (1991) 47). We also find that a unit increase in satisfaction with CHP will lead to a 54% in CHP capacity. We find significant evidence on the cost effectiveness of CHP under conservative assumptions. Regarding the influence of satisfaction and performance indicators for the several plants, the survey threw some unexpected evidence on the nature of CHP

Review of tri-generation technologies: Design evaluation, optimization, decision-making, and selection approach

International Nuclear Information System (INIS)

Al Moussawi, Houssein; Fardoun, Farouk; Louahlia-Gualous, Hasna

2016-01-01

Highlights: • Trigeneration technologies classified and reviewed according to prime movers. • Relevant heat recovery equipment discussed with thermal energy storage. • Trigeneration evaluated based on energy, exergy, economy, environment criteria. • Design, optimization, and decision-making methods classified and presented. • System selection suggested according to user preferences. - Abstract: Electricity, heating, and cooling are the three main components constituting the tripod of energy consumption in residential, commercial, and public buildings all around the world. Their separate generation causes higher fuel consumption, at a time where energy demands and fuel costs are continuously rising. Combined cooling, heating, and power (CCHP) or trigeneration could be a solution for such challenge yielding an efficient, reliable, flexible, competitive, and less pollutant alternative. A variety of trigeneration technologies are available and their proper choice is influenced by the employed energy system conditions and preferences. In this paper, different types of trigeneration systems are classified according to the prime mover, size and energy sequence usage. A leveled selection procedure is subsequently listed in the consecutive sections. The first level contains the applied prime mover technologies which are considered to be the heart of any CCHP system. The second level comprises the heat recovery equipment (heating and cooling) of which suitable selection should be compatible with the used prime mover. The third level includes the thermal energy storage system and heat transfer fluid to be employed. For each section of the paper, a survey of conducted studies with CHP/CCHP implementation is presented. A comprehensive table of evaluation criteria for such systems based on energy, exergy, economy, and environment measures is performed, along with a survey of the methods used in their design, optimization, and decision-making. Moreover, a classification

Optimization of Edwards vacuum coating unit model E12E for the production of thin films

International Nuclear Information System (INIS)

Ruiz P, H.S.

1995-01-01

This work is about an Edwards vacuum coating unit model E12E, it shows the principle of vacuum thermal evaporation, some observations in the operation of vacuum diffusion pumps, mechanical pumps, vacuum gauge, Penning and Pirani, and some equations of leak vacuum, after the modifications and additions of Edwards vacuum coating unit for optimization, the last part contains a concise introduction about thin films and one specific application, it also contains the recommendations and requirements to keep the system in good conditions. (Author)

Techno-economic analysis of a coal-fired CHP based combined heating system with gas-fired boilers for peak load compensation

International Nuclear Information System (INIS)

Wang Haichao; Jiao Wenling; Lahdelma, Risto; Zou Pinghua

2011-01-01

Combined heat and power (CHP) plants dominate the heating market in China. With the ongoing energy structure reformation and increasing environmental concerns, we propose gas-fired boilers to be deployed in underperforming heating substations of heating networks for peak load compensation, in order to improve both energy efficiency and environmental sustainability. However, due to the relatively high price of gas, techno-economic analysis is required for evaluating different combined heating scenarios, characterized by basic heat load ratio (β). Therefore, we employ the dynamic economics and annual cost method to develop a techno-economic model for computing the net heating cost of the system, considering the current state of the art of cogeneration systems in China. The net heating cost is defined as the investment costs and operations costs of the system subtracted by revenues from power generation. We demonstrate the model in a real-life combined heating system of Daqing, China. The results show that the minimum net heating cost can be realized at β=0.75 with a cost reduction of 16.8% compared to coal heating alone. Since fuel cost is the dominating factor, sensitivity analyses on coal and gas prices are discussed subsequently. - Highlights: ► Combined heating systems comply with the energy structure reformation in China. ► We consider the current state of the art of cogeneration systems in China. ► Combined heating systems can be economically more feasible and sustainable. ► The net heating cost of a combined heating system is more sensitive to coal price. ► The optimal basic heat load ratio is more easily influenced by gas price.

Fuel cell processor with low-temperature PEM fuel cell - testing. Final report; Naturgasreformersystem med lavtgemperatur-PEM braendselsceller - TEST. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Bech-Madsen, J.

2006-11-03

The purpose of the project is to further develop a Danish natural gas reformer system including optimisation of subsystems and the overall system consisting of a natural gas reformer and fuel cell CHP generator. This will contribute to the evaluation of to what extend Denmark shall develop small reformer units for PEM fuel Cells. In the project a reformer system with a high degree of automatic control has been build that fulfils the CHP requirements to operation time, dynamics etc. This work, with a FP05 reformer unit, has given valuable results concerning the possibilities and limitations of the reformer technology for CHP usage. It is important that the reformer and fuel cell units are designed with matching yields to optimise efficiency, turn-down start-up time etc. The burner that delivers heat for the steam reaction shall be able to use natural gas as fuel. This gives the possibility of using existing burner technology. In addition this will improve the efficiency since it will not be necessary to reform natural gas to feed the burner. The large number of BoP components in the FP05 unit is primarily used for achieving good regulation dynamics and accuracy. To reduce the number of components, a CHP unit with few or only one operational point should be considered. A single point of operation will reduce the number of valves as well as the requirements to the control and regulation of the system. A large part of the reformer size is needed to meet the high demands for CO purification of the reformat. This purification results in a very narrow window of operation for the reformer system. By using more CO tolerant fuel cells this part of the system can be reduced or even eliminated. To test the developed automatic control it was planned to integrate the FP05 reformer with a 10kW CHP unit that was being build by IRD in a separate project. This unit was perfect in size for testing with the reformer. However due to a number of reasons it was not possible during the

Factors that are influencing the economical efficiency of the CHP plants

International Nuclear Information System (INIS)

Ruieneanu, Liviu; Ion, Mircea

2004-01-01

This paper presents some factors that might influence the economical efficiency of a cogeneration plant. These factors are: the understanding of the fuel economy at consumers; - the influence of the electricity production efficiency; - the influence of exergy losses. The statistical data for different countries of Europe show that under the conditions of a deregulated liberalized market of energy the cogeneration plants have numerous financial difficulties. Even if the use of cogeneration ensures a fuel saving, if this economy it is not obvious for the consumers, those consumers might prefer for the production of heat the use of a heat only generating plant. This trend might spread rapidly if the increase of the electricity will not be present immediately in the bill of the consumers that renounce to the heat produced by the CHP plant. The method used for cost allocation on both types of energy has also a great importance, because it might facilitate the rehabilitation measures and doing so it might allow lower prices for both types of energy. Perhaps the most important factor for the economical efficiency of the plant are the exergy losses. The analysis presented above shows two things, namely: - that the electricity production has a very high price, and this cost might be lowered down by some rehabilitation measures (for example repowering); - and that the heat only plants (boilers) are not affected by the exergy losses and that's why if we analyse only the heat production, the use of cogeneration might seem inappropriate

76 FR 5832 - International Business Machines (IBM), Software Group Business Unit, Optim Data Studio Tools QA...

Science.gov (United States)

2011-02-02

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,554] International Business Machines (IBM), Software Group Business Unit, Optim Data Studio Tools QA, San Jose, CA; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated November 29, 2010, a worker and a state workforce official...

Stochastic Modeling and Analysis of Power System with Renewable Generation

DEFF Research Database (Denmark)

Chen, Peiyuan

Unlike traditional fossil-fuel based power generation, renewable generation such as wind power relies on uncontrollable prime sources such as wind speed. Wind speed varies stochastically, which to a large extent determines the stochastic behavior of power generation from wind farms...... that such a stochastic model can be used to simulate the effect of load management on the load duration curve. As CHP units are turned on and off by regulating power, CHP generation has discrete output and thus can be modeled by a transition matrix based discrete Markov chain. As the CHP generation has a strong diurnal...

Probabilistic energy management of a renewable microgrid with hydrogen storage using self-adaptive charge search algorithm

International Nuclear Information System (INIS)

Niknam, Taher; Golestaneh, Faranak; Shafiei, Mehdi

2013-01-01

Micro Grids (MGs) are clusters of the DER (Distributed Energy Resource) units and loads which can operate in both grid-connected and island modes. This paper addresses a probabilistic cost optimization scheme under uncertain environment for the MGs with several multiple Distributed Generation (DG) units. The purpose of the proposed approach is to make decisions regarding to optimizing the production of the DG units and power exchange with the upstream network for a Combined Heat and Power (CHP) system. A PEMFCPP (Proton Exchange Membrane Fuel cell power plant) is considered as a prime mover of the CHP system. An electrochemical model for representation and performance of the PEMFC is applied. In order to best use of the FCPP, hydrogen production and storage management are carried out. An economic model is organized to calculate the operation cost of the MG based on the electrochemical model of the PEMFC and hydrogen storage. The proposed optimization scheme comprises a self-adaptive Charged System Search (CSS) linked to the 2m + 1 point estimate method. The 2m + 1 point estimate method is employed to cover the uncertainty in the following data: the hourly market tariffs, electrical and thermal load demands, available output power of the PhotoVoltaic (PV) and Wind Turbines (WT) units, fuel prices, hydrogen selling price, operation temperature of the FC and pressure of the reactant gases of FC. The Self-adaptive CSS (SCSS) is organized based on the CSS algorithm and is upgraded by some modification approaches, mainly a self-adaptive reformation approach. In the proposed reformation method, two updating approaches are considered. Each particle based on the ability of those approaches to find optimal solutions in the past iterations, chooses one of them to improve its solution. The effectiveness of the proposed approach is verified on a multiple-DG MG in the grid-connected mode. -- Highlights: ► Consider the effect of Hydrogen produced by PEMFC on MGs. ► Combines

Midwest Clean Energy Application Center

Energy Technology Data Exchange (ETDEWEB)

Cuttica, John; Haefke, Cliff

2013-12-31

The Midwest Clean Energy Application Center (CEAC) was one of eight regional centers that promoted and assisted in transforming the market for combined heat and power (CHP), waste heat to power (WHP), and district energy (DE) technologies and concepts throughout the United States between October 1, 2009 and December 31, 2013. The key services the CEACs provided included: Market Opportunity Analyses – Supporting analyses of CHP market opportunities in diverse markets including industrial, federal, institutional, and commercial sectors. Education and Outreach – Providing information on the energy and non-energy benefits and applications of CHP to state and local policy makers, regulators, energy end-users, trade associations and others. Information was shared on the Midwest CEAC website: www.midwestcleanergy.org. Technical Assistance – Providing technical assistance to end-users and stakeholders to help them consider CHP, waste heat to power, and/or district energy with CHP in their facility and to help them through the project development process from initial CHP screening to installation. The Midwest CEAC provided services to the Midwest Region that included the states of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin.

Optimal sizing study of hybrid wind/PV/diesel power generation unit

Energy Technology Data Exchange (ETDEWEB)

Belfkira, Rachid; Zhang, Lu; Barakat, Georges [Groupe de Recherche en Electrotechnique et Automatique du Havre, University of Le Havre, 25 rue Philippe Lebon, BP 1123, 76063 Le Havre (France)

2011-01-15

In this paper, a methodology of sizing optimization of a stand-alone hybrid wind/PV/diesel energy system is presented. This approach makes use of a deterministic algorithm to suggest, among a list of commercially available system devices, the optimal number and type of units ensuring that the total cost of the system is minimized while guaranteeing the availability of the energy. The collection of 6 months of data of wind speed, solar radiation and ambient temperature recorded for every hour of the day were used. The mathematical modeling of the main elements of the hybrid wind/PV/diesel system is exposed showing the more relevant sizing variables. A deterministic algorithm is used to minimize the total cost of the system while guaranteeing the satisfaction of the load demand. A comparison between the total cost of the hybrid wind/PV/diesel energy system with batteries and the hybrid wind/PV/diesel energy system without batteries is presented. The reached results demonstrate the practical utility of the used sizing methodology and show the influence of the battery storage on the total cost of the hybrid system. (author)

Improved Taguchi method based contract capacity optimization for industrial consumer with self-owned generating units

International Nuclear Information System (INIS)

Yang, Hong-Tzer; Peng, Pai-Chun

2012-01-01

Highlights: ► We propose an improved Taguchi method to determine the optimal contract capacities with SOGUs. ► We solve the highly discrete and nonlinear optimization problem for the contract capacities with SOGUs. ► The proposed improved Taguchi method integrates PSO in Taguchi method. ► The customer using the proposed optimization approach may save up to 12.18% of power expenses. ► The improved Taguchi method can also be well applied to the other similar problems. - Abstract: Contract capacity setting for industrial consumer with self-owned generating units (SOGUs) is a highly discrete and nonlinear optimization problem considering expenditure on the electricity from the utility and operation costs of the SOGUs. This paper proposes an improved Taguchi method that combines existing Taguchi method and particle swarm optimization (PSO) algorithm to solve this problem. Taguchi method provides fast converging characteristics in searching the optimal solution through quality analysis in orthogonal matrices. The integrated PSO algorithm generates new solutions in the orthogonal matrices based on the searching experiences during the evolution process to further improve the quality of solution. To verify feasibility of the proposed method, the paper uses the real data obtained from a large optoelectronics factory in Taiwan. In comparison with the existing optimization methods, the proposed improved Taguchi method has superior performance as revealed in the numerical results in terms of the convergence process and the quality of solution obtained.

Opportunities and challenges for the future utilization of bio methane in regional energy supply structures; Chancen und Herausforderungen fuer die zukuenftige Nutzung von Biomethan in regionalen Energieversorgungsstrukturen

Energy Technology Data Exchange (ETDEWEB)

Scholwin, Frank; Nelles, Michael [Rostock Univ. (Germany). Professur Biogas/Bioenergie

2013-10-01

In fact, that the transition of the energy system needs a decentralisation of energy supply. Energy from biomass will play an important role for stabilisation of energy supply and compensation of fluctuating energy demand and energy supply from solar and wind power. Especially biomethane what can be stored in the natural gas grid allows high flexibility in its use. Therefore the following options are analysed: - Integration of biomethane/biogas driven CHP units in local heat supply structures - Flexible operation of biomethane/biogas driven CHP units - Synergies through utilisation of biomethane as vehicle fuel. (orig.)

Finding Multiple Optimal Solutions to Optimal Load Distribution Problem in Hydropower Plant

Directory of Open Access Journals (Sweden)

Xinhao Jiang

2012-05-01

Full Text Available Optimal load distribution (OLD among generator units of a hydropower plant is a vital task for hydropower generation scheduling and management. Traditional optimization methods for solving this problem focus on finding a single optimal solution. However, many practical constraints on hydropower plant operation are very difficult, if not impossible, to be modeled, and the optimal solution found by those models might be of limited practical uses. This motivates us to find multiple optimal solutions to the OLD problem, which can provide more flexible choices for decision-making. Based on a special dynamic programming model, we use a modified shortest path algorithm to produce multiple solutions to the problem. It is shown that multiple optimal solutions exist for the case study of China’s Geheyan hydropower plant, and they are valuable for assessing the stability of generator units, showing the potential of reducing occurrence times of units across vibration areas.

Specialized software for optimization of the quality control of the mammography units

International Nuclear Information System (INIS)

Stoeva, M.; Vassileva, J.

2004-01-01

Quality control is essential to ensure the equipment used is reliable and consistent in order to maintain radiation does as low as reasonably achievable whilst optimizing image quality and performance in mammography. The effectiveness of mammographic screening is highly dependent on the consistent production of high quality diagnostic images. Mammography is highly dependent on the equipment status, which requires an effective Quality Control (QC) program to provide tools for continuous assessment of the equipment performance and also data storage and analysis of the protocols' data. The objective of this paper is to present the specialized software for Quality Control of the Mammography Units, as tool providing additional functionality for optimizations of the Mammography QC data storage and management. The PC program was developed according to the requirements stated in the European protocol for Quality Control of the Mammography Screening and the data collected as a result of its application in several Bulgarian hospitals. The Structured Analysis method was used in order to perform a case, which resulted in the development of the specialized software with a database module, providing the following functionality: Data Storage, Preliminary Data Processing and Post-Processing, Manual Data Entry, Data Import from XLS format, Data Export to XLS format, Printing, Data Filters, Automated Calculation, Automated Graphical Representation, Archiving The development of specialized QC software with a database for mammography units facilitates the process of QC data storage and handling and minimizes the errors. The electronic format for data storage is especially useful in case of long-term storage and periodical data analysis/access. The integrated data processing functionality and the automated import/export features based on standard platform increase the compatibility of the data. (authors)

Optimization of Boiler Control to Improve the Load-following Capability of Power-plant Units

OpenAIRE

Mortensen, J. H.; Mølbak, T.; Andersen, Palle; Pedersen, Tom Søndergaard

1998-01-01

The capability to perform fast load changes has been an important issue in the power market, and will become increasingly more so due to the incresing commercialisation of the European power market. An optimizing control system for improving the load-following capability of power-plant units has therefore been developed. The system is implemented as a complement, producing control signals to be added to those of the existing boiler control system, a concept which has various practical advanta...

Flexible 75 kWel Stirling CHP-plant for bio-fuels with low emissions and a high fuel utilization. Final technical report

Energy Technology Data Exchange (ETDEWEB)

2011-07-01

The objective of the project ''Flexible 75 kWel Stirling CHP-plant for bio-fuels with low emissions and a high fuel utilization'' was to combine the Danish experiences with the Stirling engine and updraft gasification with the application of the FLOX gas burner technology for developing and demonstrating a flexible biomass-based small scale CHP plant with 75 kW electrical output, high power efficiency and low emissions. Further, the project has aimed at increasing the technology's reliability and decreasing the need for service. Also, the project has included the development of a control and communication system for unmanned start-up and operation of the plant. During the project the objective was altered and so the development of a new Stirling engine design was done on the 4-cylindred 35 kWe Stirling engine instead of the 8-cylindred 75 kWe Stirling engine. Focus has been on designing a more durable engine designed for easy and fast service. Cold test of the engine has been successful and now full-scale hot tests are to be performed. In the project Stirling DK has also in cooperation with project partner Danish gas Technology Centre developed the Stirling Engine with Diluted Oxidation (SEDIOX) concept which is a combustion technology based on the diluted oxidation principle. A trademark is obtained and also a patent application is filed and pending regarding the SEDIOX combustion chamber concept. All components for the Stirling gasification plant were produced and installed at Svanholm Estate. The plant consisted of one conventional combustion chamber and one SD3E-type Stirling engine. The plant was commissioned in June 2009 and 1,472 hours of operation and 43 MWh of electricity production was achieved before the plant was de-commissioned in February 2010 due to divergences between Svanholm Estate and Stirling DK. During operation the control system including remote access was tested thoroughly and with great success. The new overall

Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

OpenAIRE

Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

2014-01-01

In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler...

A Comparative Study of Fuzzy Logic, Genetic Algorithm, and Gradient-Genetic Algorithm Optimization Methods for Solving the Unit Commitment Problem

Directory of Open Access Journals (Sweden)

Sahbi Marrouchi

2014-01-01

Full Text Available Due to the continuous increase of the population and the perpetual progress of industry, the energy management presents nowadays a relevant topic that concerns researchers in electrical engineering. Indeed, in order to establish a good exploitation of the electrical grid, it is necessary to solve technical and economic problems. This can only be done through the resolution of the Unit Commitment Problem. Unit Commitment Problem allows optimizing the combination of the production units’ states and determining their production planning, in order to satisfy the expected consumption with minimal cost during a specified period which varies usually from 24 hours to one week. However, each production unit has some constraints that make this problem complex, combinatorial, and nonlinear. This paper presents a comparative study between a strategy based on hybrid gradient-genetic algorithm method and two strategies based on metaheuristic methods, fuzzy logic, and genetic algorithm, in order to predict the combinations and the unit commitment scheduling of each production unit in one side and to minimize the total production cost in the other side. To test the performance of the optimization proposed strategies, strategies have been applied to the IEEE electrical network 14 busses and the obtained results are very promising.

Techno-economic optimization of flexible biogas concepts in the context of EEG; Technisch-oekonomische Optimierung von flexiblen Biogaskonzepten im Kontext des EEG

Energy Technology Data Exchange (ETDEWEB)

Barchmann, Tino; Lauer, Markus [DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH, Leipzig (Germany)

2014-08-01

Due to the introduction of direct marketing and flexibility premium of renewable energy by the Renewable Energy Act 2012 (EEG 2012), incentives were created to favour a more demand-oriented power supply from biogas plants (BGA). The decision for such an operational mode depends on on-site conversion units on the economic outcome of the plants throughout the whole operating time. To install new plants or transfer existing plants into a flexible mode of operation, investments in additional and more efficient combined heat and power plants (CHP), in additional gas and/or heat storage and other technical components are necessary. The analyses show that the flexibility premium, as an extra of the market premium model, creates the greatest incentive for a more flexible generation of electricity from biogas. In addition, an intelligent management optimization can generate additional revenues on EPEX SPOT SE and balancing energy market. The additional revenues of more demand-oriented power supply from biogas plants are highly dependent on plant-specific conditions. From an economic perspective, a duplication of the installed electrical capacity seems to be the most beneficial option for a transition to a demand-driven operation mode of an average biogas model plant under the current legal framework (EEG 2012).

Load scheduling for decentralized CHP plants

DEFF Research Database (Denmark)

Nielsen, Henrik Aalborg, orlov 31.07.2008; Madsen, Henrik; Nielsen, Torben Skov

) an interactive decision support tool by which optimal schedules can be found given the forecasts or user-defined modifications of the forecasts, and (iii) an automatic on-line system for monitoring when conditions have changed so that rescheduling is appropriate. In this report the focus is on methods applicable...... be obtained. Furthermore, we believe that all relevant forecasting methods are far too complicated to allow for this integration; both uncertainties originating from the dependence of heat load on climate and from meteorological forecasts need to be taken into account. Instead we suggest that the decision....... By letting the system find optimal schedules for each of these realizations the operator can gain some insight into the importance of the uncertainties. It is shown that with modern personal computers (e.g. 1 GHz Pentium III), operating systems (e.g. RedHat Linux 6.0), and compilers (e.g. GNU C 2...

Solving optimum operation of single pump unit problem with ant colony optimization (ACO) algorithm

International Nuclear Information System (INIS)

Yuan, Y; Liu, C

2012-01-01

For pumping stations, the effective scheduling of daily pump operations from solutions to the optimum design operation problem is one of the greatest potential areas for energy cost-savings, there are some difficulties in solving this problem with traditional optimization methods due to the multimodality of the solution region. In this case, an ACO model for optimum operation of pumping unit is proposed and the solution method by ants searching is presented by rationally setting the object function and constrained conditions. A weighted directed graph was constructed and feasible solutions may be found by iteratively searching of artificial ants, and then the optimal solution can be obtained by applying the rule of state transition and the pheromone updating. An example calculation was conducted and the minimum cost was found as 4.9979. The result of ant colony algorithm was compared with the result from dynamic programming or evolutionary solving method in commercial software under the same discrete condition. The result of ACO is better and the computing time is shorter which indicates that ACO algorithm can provide a high application value to the field of optimal operation of pumping stations and related fields.

Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

International Nuclear Information System (INIS)

Lythcke-Jørgensen, Christoffer; Haglind, Fredrik; Clausen, Lasse R.

2014-01-01

Highlights: • We model a system where lignocellulosic ethanol production is integrated with a combined heat and power (CHP) plant. • We conduct an exergy analysis for the ethanol production in six different system operation points. • Integrated operation, district heating (DH) production and low CHP loads all increase the exergy efficiency. • Separate operation has the largest negative impact on the exergy efficiency. • Operation is found to have a significant impact on the exergy efficiency of the ethanol production. - Abstract: Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol production. An exergy analysis is carried out for a modelled polygeneration system in which lignocellulosic ethanol production based on hydrothermal pretreatment is integrated in an existing combined heat and power (CHP) plant. The ethanol facility is driven by steam extracted from the CHP unit when feasible, and a gas boiler is used as back-up when integration is not possible. The system was evaluated according to six operation points that alternate on the following three different operation parameters: Load in the CHP unit, integrated versus separate operation, and inclusion of district heating production in the ethanol facility. The calculated standard exergy efficiency of the ethanol facility varied from 0.564 to 0.855, of which the highest was obtained for integrated operation at reduced CHP load and full district heating production in the ethanol facility, and the lowest for separate operation with zero district heating production in the ethanol facility. The results suggest that the efficiency of integrating lignocellulosic ethanol production in CHP plants is highly dependent on operation, and it is therefore suggested that the

Cogeneration of heat and electricity from rape oil with a little CHP unit in a car wash

International Nuclear Information System (INIS)

Pilz, H.D.; Thomas, S.; Zeilinger, J.

2002-01-01

Environmentally friendly energy supply system for smaller houses is described. In Elsbett system the so-called multi fuel engine starts the combined electricity and heat production unit. In such a system one can use also natural fuels, animal oils and fats besides heating oil. Therefore no additional CO 2 is produced, but it will be brought to the balanced natural circle

Energy and Exergy Analysis and Optimization of Combined Heat and Power Systems. Comparison of Various Systems

Directory of Open Access Journals (Sweden)

Monica Costea

2012-09-01

Full Text Available The paper presents a comparison of various CHP system configurations, such as Vapour Turbine, Gas Turbine, Internal Combustion Engine, External Combustion Engine (Stirling, Ericsson, when different thermodynamic criteria are considered, namely the first law efficiency and exergy efficiency. Thermodynamic optimization of these systems is performed intending to maximize the exergy, when various practical related constraints (imposed mechanical useful energy, imposed heat demand, imposed heat to power ratio or main physical limitations (limited heat availability, maximum system temperature allowed, thermo-mechanical constraints are taken into account. A sensitivity analysis to model parameters is given. The results have shown that the various added constraints were useful for the design allowing to precise the influence of the model main parameters on the system design. Future perspective of the work and recommendations are stated.

Studying effect of heating plant parameters on performances of a geothermal-fuelled series cogeneration plant based on Organic Rankine Cycle

International Nuclear Information System (INIS)

Habka, Muhsen; Ajib, Salman

2014-01-01

Highlights: • We analyzed performances of a series ORC–CHP plant versus the heating plant parameters. • ORC–CHP power is destructed when raising the heat demand or the return temperature. • Only the high supply temperatures of the heating plant affect negatively the performances. • Reducing the return temperature optimizes both the energetic and exergetic criteria. • Increasing the heat demand improves the exergetic efficiency of the total CHP system. - Abstract: The present work aims to analyze the performance characteristics of the series Combined Heat and Power (CHP) system based on Organic Rankine Cycle (ORC) under influence of the heating plant parameters without considering the chemistry of the geothermal water considered as heat source. For evaluation, energetic and exergetic criteria along with the heat transfer capacities have been determined, and also the working fluid R134a has been used. The results showed that increasing the heat demand or the return temperature and only the high supply temperatures lead to destruct the net power generated by the ORC–CHP system. While, influence of the last parameters on the total exergy efficiency and losses is different; whereas raising the heat demands optimizes these exergetic indicators, variation of the supply temperature leads to an optimum for these performances. Since increasing the return temperature has purely negative impacts on all exergetic and energetic criteria, the latter can be improved by reducing this temperature with attention to the heat transfer capacities. Thus, reduction of the return temperature about 5 °C lowers the exhausted stream losses by app. 25% and enhances the power generation by app. 52% and the total exergy efficiency by 9%

Technical assessment of a micro-cogeneration system based on polymer electrolyte membrane fuel cell and fluidized bed autothermal reformer

International Nuclear Information System (INIS)

Di Marcoberardino, Gioele; Roses, Leonardo; Manzolini, Giampaolo

2016-01-01

Highlights: • Performances of an ATR membrane reactor within a PEM FC micro-CHP system of 5 kWel. • Analysis of two different options for the H_2 permeate side: sweep and vacuum pump. • Optimization of operating conditions in terms of efficiency and membrane area. • Distribution of power and thermal consumptions and losses were discussed in detail. • A sensitivity analysis highlights the relevant design parameters of the CHP system. - Abstract: This work investigates the integration of an autothermal membrane reformer within a micro-CHP system of 5 kWel based on PEM fuel cell. The system modeled is based on a prototype developed within Reforcell European project. The optimization of the micro-CHP system is performed from a thermodynamic point of view aiming at the target of 40% of net electric efficiency and 90% of total system efficiency comparing different configuration and operating conditions. In particular, two hydrogen permeate side options as vacuum or sweep steam are evaluated together with different combination of feed temperature and pressures. A good compromise between electric efficiency (40%) and membrane surface area (0.3 m"2) was obtained for the sweep gas case at reaction side conditions of 8 bar, 600 °C and S/C of 2.5. Higher electric efficiency (40.5%) could be achieved by increasing the membrane surface area. The adoption of a vacuum pump simplifies the reactor design and manufacturing, but reduces the net electric efficiency by about 2% points with a membrane surface area of 0.15 m"2. Finally, the sensitivity analysis highlighted the influence of the main parameters and the design criteria for the definition of the CHP system.

Optimization of a Nucleic Acids united-RESidue 2-Point model (NARES-2P) with a maximum-likelihood approach

International Nuclear Information System (INIS)

He, Yi; Scheraga, Harold A.; Liwo, Adam

2015-01-01

Coarse-grained models are useful tools to investigate the structural and thermodynamic properties of biomolecules. They are obtained by merging several atoms into one interaction site. Such simplified models try to capture as much as possible information of the original biomolecular system in all-atom representation but the resulting parameters of these coarse-grained force fields still need further optimization. In this paper, a force field optimization method, which is based on maximum-likelihood fitting of the simulated to the experimental conformational ensembles and least-squares fitting of the simulated to the experimental heat-capacity curves, is applied to optimize the Nucleic Acid united-RESidue 2-point (NARES-2P) model for coarse-grained simulations of nucleic acids recently developed in our laboratory. The optimized NARES-2P force field reproduces the structural and thermodynamic data of small DNA molecules much better than the original force field

Techno-economic performance analysis of bio-oil based Fischer-Tropsch and CHP synthesis platform

International Nuclear Information System (INIS)

Ng, Kok Siew; Sadhukhan, Jhuma

2011-01-01

The techno-economic potential of the UK poplar wood and imported oil palm empty fruit bunch derived bio-oil integrated gasification and Fischer-Tropsch (BOIG-FT) systems for the generation of transportation fuels and combined heat and power (CHP) was investigated. The bio-oil was represented in terms of main chemical constituents, i.e. acetic acid, acetol and guaiacol. The compositional model of bio-oil was validated based on its performance through a gasification process. Given the availability of large scale gasification and FT technologies and logistic constraints in transporting biomass in large quantities, distributed bio-oil generations using biomass pyrolysis and centralised bio-oil processing in BOIG-FT system are technically more feasible. Heat integration heuristics and composite curve analysis were employed for once-through and full conversion configurations, and for a range of economies of scale, 1 MW, 675 MW and 1350 MW LHV of bio-oil. The economic competitiveness increases with increasing scale. A cost of production of FT liquids of 78.7 Euro/MWh was obtained based on 80.12 Euro/MWh of electricity, 75 Euro/t of bio-oil and 116.3 million Euro/y of annualised capital cost. -- Highlights: → Biomass to liquid process and gas to liquid process synthesis. → Biorefinery economic analysis. → Pyrolysis oil to biofuel. → Gasification and Fischer-Tropsch. → Process integration, pinch analysis and energy efficiency.

Clinical review of supracricoid laryngectomy with CHEP and CHP. 50 patients treated in 11 years

International Nuclear Information System (INIS)

Nakayama, Meijin; Seino, Yutomo; Hayashi, Seiichi; Miyamoto, Shunsuke; Takeda, Masahiko; Masaki, Takashi; Yokobori, Satoru; Okamoto, Makito

2009-01-01

An analysis of clinical data on 50 patients undergoing supracricoid laryngectomy (SCL) between 1997 and 2008 id est (i.e.), cricohyoidoepiglottopexy (CHEP) in 47 and cricohyoidopexy (CHP) in 3 cases showed that the number of SCL cases operated on within a year surpassed that of Total Laryngectomy after 2003. Selection criteria included performance status 0-1 and blood gas PO2>80 torr, especially in those patients over 70 years old. Postoperative wound infection occurred in 16 patients (32%), with four requiring additional surgical intervention (two ruptured pexis and two chondritis induced by C3-C4 osteophytes). A history of radiotherapy and systemic complications, i.e., diabetes and renal failure, added to the risk of wound infection. Introducing a clinical pathway shortened hospitalization. Vocal function was achieved in 96% and swallowing function in 89% of patients. Five-year crude survival in CHEP was 69% and in total laryngectomy (TL) 51%. Laryngeal preservation was 70%, increasing to 89% after the introduction of SCL. SCL-CHEP is thus indicated for unfavorable T2 (ASCO 2006), well-selected T3, T4, and rT1-4 (radiation failures). Effort should emphasize a good balance in prognosis and function in organ preservation for laryngeal cancer. (author)

Modelling of a Naphtha Recovery Unit (NRU with Implications for Process Optimization

Directory of Open Access Journals (Sweden)

Jiawei Du

2018-06-01

Full Text Available The naphtha recovery unit (NRU is an integral part of the processes used in the oil sands industry for bitumen extraction. The principle role of the NRU is to recover naphtha from the tailings for reuse in this process. This process is energy-intensive, and environmental guidelines for naphtha recovery must be met. Steady-state models for the NRU system are developed in this paper using two different approaches. The first approach is a statistical, data-based modelling approach where linear regression models have been developed using Minitab® from plant data collected during a performance test. The second approach involves the development of a first-principles model in Aspen Plus® based on the NRU process flow diagram. A novel refinement to this latter model, called “withdraw and remix”, is proposed based on comparing actual plant data to model predictions around the two units used to separate water and naphtha. The models developed in this paper suggest some interesting ideas for the further optimization of the process, in that it may be possible to achieve the required naphtha recovery using less energy. More plant tests are required to validate these ideas.

Electric Energy Consumption of the Full Scale Research Biogas Plant “Unterer Lindenhof”: Results of Longterm and Full Detail Measurements

Directory of Open Access Journals (Sweden)

Thomas Jungbluth

2012-12-01

Full Text Available This work thoroughly evaluates the electric power consumption of a full scale, 3 × 923 m3 complete stirred tank reactor (CSTR research biogas plant with a production capacity of 186 kW of electric power. The plant was fed with a mixture of livestock manure and renewable energy crops and was operated under mesophilic conditions. This paper will provide an insight into precise electric energy consumption measurements of a full scale biogas plant over a period of two years. The results showed that a percentage of 8.5% (in 2010 and 8.7% (in 2011 of the produced electric energy was consumed by the combined heat and power unit (CHP, which was required to operate the biogas plant. The consumer unit agitators with 4.3% (in 2010 and 4.0% (in 2011 and CHP unit with 2.5% (in 2010 and 2011 accounted for the highest electrical power demand, in relation to the electric energy produced by the CHP unit. Calculations show that 51% (in 2010 and 46% (in 2011 of the total electric energy demand was due to the agitators. The results finally showed the need for permanent measurements to identify and quantify the electric energy saving potentials of full scale biogas plants.

Progress along developmental tracks for electronic health records implementation in the United States

Directory of Open Access Journals (Sweden)

Hollar David W

2009-03-01

Full Text Available Abstract The development and implementation of electronic health records (EHR have occurred slowly in the United States. To date, these approaches have, for the most part, followed four developmental tracks: (a Enhancement of immunization registries and linkage with other health records to produce Child Health Profiles (CHP, (b Regional Health Information Organization (RHIO demonstration projects to link together patient medical records, (c Insurance company projects linked to ICD-9 codes and patient records for cost-benefit assessments, and (d Consortia of EHR developers collaborating to model systems requirements and standards for data linkage. Until recently, these separate efforts have been conducted in the very silos that they had intended to eliminate, and there is still considerable debate concerning health professionals access to as well as commitment to using EHR if these systems are provided. This paper will describe these four developmental tracks, patient rights and the legal environment for EHR, international comparisons, and future projections for EHR expansion across health networks in the United States.

Stochastic control and real options valuation of thermal storage-enabled demand response from flexible district energy systems

International Nuclear Information System (INIS)

Kitapbayev, Yerkin; Moriarty, John; Mancarella, Pierluigi

2015-01-01

Highlights: • We calculate the real option value of flexibility from CHP-thermal storage. • Stochastic optimal feedback control problem is solved under uncertain market prices. • Efficient real-time numerical solutions combine simulation, regression and recursion. • Clear, interpretable feedback control maps are produced for each hour of the day. • We give a realistic UK case study using projected market gas and electricity prices. - Abstract: In district energy systems powered by Combined Heat and Power (CHP) plants, thermal storage can significantly increase CHP flexibility to respond to real time market signals and therefore improve the business case of such demand response schemes in a Smart Grid environment. However, main challenges remain as to what is the optimal way to control inter-temporal storage operation in the presence of uncertain market prices, and then how to value the investment into storage as flexibility enabler. In this outlook, the aim of this paper is to propose a model for optimal and dynamic control and long term valuation of CHP-thermal storage in the presence of uncertain market prices. The proposed model is formulated as a stochastic control problem and numerically solved through Least Squares Monte Carlo regression analysis, with integrated investment and operational timescale analysis equivalent to real options valuation models encountered in finance. Outputs are represented by clear and interpretable feedback control strategy maps for each hour of the day, thus suitable for real time demand response under uncertainty. Numerical applications to a realistic UK case study with projected market gas and electricity prices exemplify the proposed approach and quantify the robustness of the selected storage solutions

Effect of grid disturbances on fault-ride-through behaviour of MV-connected DG-units, in especially CHP-plants

NARCIS (Netherlands)

Coster, E.J.; Myrzik, J.M.A.; Kling, W.L.

2009-01-01

In the near future a significant amount of the consumed electrical energy will be generated by distributed generation (DG). Because of the small size these units are normally connected to the local distribution grid [1]. Connection of DG changes the operation of the distribution grid. In order to

Optimal Thermal Unit Commitment Solution integrating Renewable Energy with Generator Outage

Directory of Open Access Journals (Sweden)

S. Sivasakthi

2017-06-01

Full Text Available The increasing concern of global climate changes, the promotion of renewable energy sources, primarily wind generation, is a welcome move to reduce the pollutant emissions from conventional power plants. Integration of wind power generation with the existing power network is an emerging research field. This paper presents a meta-heuristic algorithm based approach to determine the feasible dispatch solution for wind integrated thermal power system. The Unit Commitment (UC process aims to identify the best feasible generation scheme of the committed units such that the overall generation cost is reduced, when subjected to a variety of constraints at each time interval. As the UC formulation involves many variables and system and operational constraints, identifying the best solution is still a research task. Nowadays, it is inevitable to include power system reliability issues in operation strategy. The generator failure and malfunction are the prime influencing factor for reliability issues hence they have considered in UC formulation of wind integrated thermal power system. The modern evolutionary algorithm known as Grey Wolf Optimization (GWO algorithm is applied to solve the intended UC problem. The potential of the GWO algorithm is validated by the standard test systems. Besides, the ramp rate limits are also incorporated in the UC formulation. The simulation results reveal that the GWO algorithm has the capability of obtaining economical resolutions with good solution quality.

Requirements and operation of decentralised power plants in the changing power market

International Nuclear Information System (INIS)

Hoenings, Norbert; Hornig, Niels; Steinbach, Sebastian

2014-01-01

E.ON plans and realises distributed industrial power plants on the basis of contracting schemes. Target is to reduce energy costs without investment by the customer himself. Gas turbine CHP plants are very flexible and offer many possibilities for the operator to adjust optimally to a constantly changing energy market. This aspect is becoming increasingly important due to the increasing share of renewables. However, the economic situation for CHP plants has deteriorated significantly, due to the current market situation distorted by the subsidised renewable power generation. (orig.)

Requirements and operation of decentralised power plants in the changing power market; Anforderungen und Einsatz dezentraler Kraftwerke im veraenderten Strommarkt

Energy Technology Data Exchange (ETDEWEB)

Hoenings, Norbert; Hornig, Niels; Steinbach, Sebastian [E.ON Energy Projects GmbH, Muenchen (Germany)

2014-08-01

E.ON plans and realises distributed industrial power plants on the basis of contracting schemes. Target is to reduce energy costs without investment by the customer himself. Gas turbine CHP plants are very flexible and offer many possibilities for the operator to adjust optimally to a constantly changing energy market. This aspect is becoming increasingly important due to the increasing share of renewables. However, the economic situation for CHP plants has deteriorated significantly, due to the current market situation distorted by the subsidised renewable power generation. (orig.)

Optimized raw material usage and utilization degree in a polygeneration plant for heat, electricity, biofuel and market fuel; Optimal raavaruinsats och utnyttjandegrad i energikombinat foer vaerme, el, biodrivmedel och avsalubraensle

Energy Technology Data Exchange (ETDEWEB)

Jennie Rodin; Olle Wennberg; Mikael Berntsson; Rolf Njurell; Ola Thorson

2012-01-15

Energy and economic efficiency for six different types of energy combines which include heat, electricity, pellets and fuel production have been studied. The basic case is a conventional power plant, which subsequently is expanded with various additional facilities (dryer, pellets and/or fuel). Maximum exploitation of the product against inserted biofuel was obtained in case 6, pulp mills that use waste heat for district heating supply and drying of bark. Case 6 had also the lowest payoff period; two years. Of the CHP [combined heat and power] based energy combines 'the big combine' with four different products generally showed best marginal efficiency and economy. The results indicate that drying may be an economical way to extend the operating season and increase the production of electricity in a CHP based energy combine.

JOINT ECONOMIC AND ENVIRONMENTAL OPTIMIZATION OF HYBRID POWER SUPPLY FOR LARGE SCALE RO-DESALINATION PLANT: WITH AND WITHOUT CO2 SEQUESTRATION

Directory of Open Access Journals (Sweden)

EMAN A. TORA

2016-07-01

Full Text Available In this paper, a multi- objective optimization approach is introduced to define a hybrid power supply system for a large scale RO- desalination plant. The target is to integrate a number of locally available energy resources to generate the electricity demand of the RO- desalination plant with minimizing both the electricity generation cost and the greenhouse gas emissions whereby carbon dioxide sequestration may be an option. The considered energy resources and technologies are wind turbines, solar PV, combined cycles with natural gas turbines, combined cycles with coal gasification, pulverized coal with flue gas desulfurization, and biomass combined heat and power CHP. These variable energy resources are investigated under different constraints on the renewable energy contribution. Likewise, the effect of carbon dioxide sequestration is included. Accordingly, five scenarios have been analyzed. Trade- offs between the minimum electricity generation cost and the minimum greenhouse gas emissions have been determined and represented in Pareto curves using the constraint method (. The results highlight that among the studied fossil fuel technologies, the integrated combined cycle natural gas turbines can provide considerable fraction of the needed power supply. Likewise, wind turbines are the most effective technology among renewable energy options. When CO2 sequestration applied, the costs increase and significant changes in the optimum combination of renewable energy resources have been monitored. In that case, solar PV starts to appreciably compete. The optimum mix of energy resources extends to include biomass CHP as well.

Optimal PMU Placement By Improved Particle Swarm Optimization

DEFF Research Database (Denmark)

Rather, Zakir Hussain; Liu, Leo; Chen, Zhe

2013-01-01

This paper presents an improved method of binary particle swarm optimization (IBPSO) technique for optimal phasor measurement unit (PMU) placement in a power network for complete system observability. Various effective improvements have been proposed to enhance the efficiency and convergence rate...... of conventional particle swarm optimization method. The proposed method of IBPSO ensures optimal PMU placement with and without consideration of zero injection measurements. The proposed method has been applied to standard test systems like 17 bus, IEEE 24-bus, IEEE 30-bus, New England 39-bus, IEEE 57-bus system...

ANALYSIS AND PARAMETRIC OPTIMIZATION OF ENERGY-AND-TECHNOLOGY UNITS ON THE BASIS OF THE POWER EQUIPMENT OF COMPRESSOR PLANTS OF MAIN GAS PIPELINES

Directory of Open Access Journals (Sweden)

V. A. Sednin

2017-01-01

Full Text Available On the basis of the gas compressor units of compressor plants of a main gas pipeline mathematical models of the macro-level were generated for analysis and parametric optimization of combined energy-and-technology units. In continuation of the study these models was applied to obtain the regression dependencies. For this purpose, a numerical experiment was used which had been designed with the use of regression analysis mathematical tool, which assumes that the test results should represent independent, normally distributed, random variables with approximately equal variance. Herewith we study the dependence of the optimization criterion on the value of control parameters (factors. Planning, conducting and processing of results of the experiment was conducted in the following sequence: choice of the optimization criteria, selection of control parameters (factors, encoding factors, the matrix of experiment compiling, assessing significance of regression coefficients, testing the adequacy of the model and reproducibility of the experiments. As the optimization criteria the electricity capacity and efficiency of combined energy-technology units were adopted. As control parameters for the installation with a gas-expansion-and-generator machine the temperature of the fuel gas before the expander, the pressure of the fuel gas after the expander and the temperature of the air supplied to the compressor of the engine were adopted, while for the steam turbine the adopted optimization criteria were compression in the compressor of the engine, the steam consumption for the technology and the temperature of the air supplied to the compressor of the engine. The application of the outlined methodological approach makes it possible to obtain a simple polynomial dependence, which significantly simplify the procedures of analysis, parametric optimization and evaluation of efficiency in the feasibility studies of the options of construction of the energy

Combined Heat and Power Systems for the Provision of Sustainable Energy from Biomass in Buildings

OpenAIRE

Ortwein Andreas

2016-01-01

Against the background of greenhouse gases causing climate change, combined heat and power (CHP) systems fueled by biomass can efficiently supply energy with high flexibility. Such CHP systems will usually consist of one or more thermo-chemical conversion steps and at least one (the more or less separated) electric power generation unit. Depending on the main products of the previous conversion steps (e.g. combustible gases or liquids, but also flue gases with sensible heat), different techno...

Optimal unit commitment of the power system in Bulgaria during the transitional period to power wholesale market (cont..)

International Nuclear Information System (INIS)

Stoilov, D.

2001-01-01

The first part of the parer considers the general problem of optimal yearly unit commitment in the new economical conditions in Bulgaria. The second part deals with non-convex problem , taking into account some costs for starting and stopping of power systems. The transition from yearly commitment to weekly or daily dispatching is commented

Decentralised energy supply as our future energy supply system? - An interview with Prof. Alexander Wokaun

International Nuclear Information System (INIS)

Nagel, Ch.

2002-01-01

In this interview with Professor Alexander Wokaun, head of General Energy Research at the Paul Scherrer Institute (PSI) in Villigen, Switzerland, the decentralised use of small, gas-fired combined heat and power (CHP) units is discussed as a means of meeting Switzerland's Kyoto CO 2 commitments. The question on which of several new CHP technologies such as gas-fired engines and turbines, Stirling engines, fuel cells and thermo-photovoltaics will win the race is discussed. The efficiency and application areas of CHP technologies are examined and the problems involved when controlling complex electricity grids with many small decentrally placed generating facilities is discussed. Finally, Professor Wokaun is asked for his opinion on what the Swiss power mix will look like in 20 years

Optimal Sizing of Decentralized Photovoltaic Generation and Energy Storage Units for Malaysia Residential Household Using Iterative Method

Directory of Open Access Journals (Sweden)

Rahman Hasimah Abdul

2016-01-01

Full Text Available World’s fuel sources are decreasing, and global warming phenomena cause the necessity of urgent search for alternative energy sources. Photovoltaic generating system has a high potential, since it is clean, environmental friendly and secure energy sources. This paper presents an optimal sizing of decentralized photovoltaic system and electrical energy storage for a residential household using iterative method. The cost of energy, payback period, degree of autonomy and degree of own-consumption are defined as optimization parameters. A case study is conducted by employing Kuala Lumpur meteorological data, typical load profile from rural area in Malaysia, decentralized photovoltaic generation unit and electrical storage and it is analyzed in hourly basis. An iterative method is used with photovoltaic array variable from 0.1kW to 4.0kW and storage system variable from 50Ah to 400Ah was performed to determine the optimal design for the proposed system.

Exergetic analysis and thermoeconomic study for a container-housed engine

Energy Technology Data Exchange (ETDEWEB)

Sala, J.M.; Eguia, J.; Flores, I. [Escuela Superior de Ingenieros Industriales de Bilbao, Universidad del Pais Vasco, Alameda de Urquijo, s/n 48013 Bilbao, Bizkaia (Spain); Lopez-Gonzalez, L.M.; Ruiz de Adana, M. [Escuela Tecnica Superior de Ingenieria Industrial, Universidad de La Rioja, C/Luis de Ulloa, 20. E-26004 Logrono, La Rioja (Spain); Miguez, J.L. [Universidad de Vigo, Escuela Tecnica Superior de Ingenieros Industriales, C/Lagoas-Marcosende, s/n 36200 Vigo, Pontevedra (Spain)

2006-11-15

This paper presents the engineering design and theoretical exergetic analyses for a container-housed reciprocating engine. The exergy analysis conducted was based on the first and second laws of thermodynamics for power generation systems. Using thermographic inspection, the heat dissipated by each one of the 28 elements under consideration in the engine container was assessed, together with the mass flow rate of air supplied to the cab and the air temperature at the inlet and outlet. This information is essential for the proper design of the ventilation system needed to disseminate the heat generated inside the container-housed unit. The energy balance and corresponding exergy balance were drawn up using the values thus obtained and the information available on the engine. The engine efficiency rates were evaluated on both an energy and exergy basis, taking into account that heat from the cooling circuit and exhaust fumes are used for CHP. Finally, thermoeconomics was applied to calculate the costs of the electricity and useful heat energy produced by the engine. The result of this study should be to optimize the design of container-housed CHP systems, showing where exergy losses occur and identifying areas of improvement. (author)

Exergetic analysis and thermoeconomic study for a container-housed engine

International Nuclear Information System (INIS)

Sala, J.M.; Lopez-Gonzalez, L.M.; Ruiz de Adana, M.; Miguez, J.L.; Eguia, J.; Flores, I.

2006-01-01

This paper presents the engineering design and theoretical exergetic analyses for a container-housed reciprocating engine. The exergy analysis conducted was based on the first and second laws of thermodynamics for power generation systems. Using thermographic inspection, the heat dissipated by each one of the 28 elements under consideration in the engine container was assessed, together with the mass flow rate of air supplied to the cab and the air temperature at the inlet and outlet. This information is essential for the proper design of the ventilation system needed to disseminate the heat generated inside the container-housed unit. The energy balance and corresponding exergy balance were drawn up using the values thus obtained and the information available on the engine. The engine efficiency rates were evaluated on both an energy and exergy basis, taking into account that heat from the cooling circuit and exhaust fumes are used for CHP. Finally, thermoeconomics was applied to calculate the costs of the electricity and useful heat energy produced by the engine. The result of this study should be to optimize the design of container-housed CHP systems, showing where exergy losses occur and identifying areas of improvement

Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

DEFF Research Database (Denmark)

Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

2015-01-01

In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro......-CHP system assumes heat-led operation, to avoid dumping of heat and the use of complicated thermal energy storage. The overall system is grid-interconnected to allow importing and exporting of electricity as necessary. In this study emphasis is given on the operational characterization of the system...

Methods for Analysis of Urban Energy Systems: A New York City Case Study

Science.gov (United States)

Howard, Bianca

This dissertation describes methods developed for analysis of the New York City energy system. The analysis specifically aims to consider the built environment and its' impacts on greenhouse gas (GHG) emissions. Several contributions to the urban energy systems literature were made. First, estimates of annual energy intensities of the New York building stock were derived using a statistical analysis that leveraged energy consumption and tax assessor data collected by the Office of the Mayor. These estimates provided the basis for an assessment of the spatial distribution of building energy consumption. The energy consumption estimates were then leveraged to estimate the potential for combined heat and power (CHP) systems in New York City at both the building and microgrid scales. In aggregate, given the 2009 non-baseload GHG emissions factors for electricity production, these systems could reduce citywide GHG emissions by 10%. The operational characteristics of CHP systems were explored further considering different prime movers, climates, and GHG emissions factors. A combination of mixed integer linear programing and controlled random search algorithms were the methods used to determine the optimal capacity and operating strategies for the CHP systems under the various scenarios. Lastly a multi-regional unit commitment model of electricity and GHG emissions production for New York State was developed using data collected from several publicly available sources. The model was used to estimate average and marginal GHG emissions factors for New York State and New York City. The analysis found that marginal GHG emissions factors could reduce by 30% to 370 g CO2e/kWh in the next 10 years.

Microbiological Contamination at Workplaces in a Combined Heat and Power (CHP Station Processing Plant Biomass

Directory of Open Access Journals (Sweden)

Justyna Szulc

2017-01-01

Full Text Available The aim of the study was to evaluate the microbial contamination at a plant biomass processing thermal power station (CHP. We found 2.42 × 103 CFU/m3 of bacteria and 1.37 × 104 CFU/m3 of fungi in the air; 2.30 × 107 CFU/g of bacteria and 4.46 × 105 CFU/g of fungi in the biomass; and 1.61 × 102 CFU/cm2 bacteria and 2.39 × 101 CFU/cm2 fungi in filtering facepiece respirators (FFRs. Using culture methods, we found 8 genera of mesophilic bacteria and 7 of fungi in the air; 10 genera each of bacteria and fungi in the biomass; and 2 and 5, respectively, on the FFRs. Metagenomic analysis (Illumina MiSeq revealed the presence of 46 bacterial and 5 fungal genera on the FFRs, including potential pathogens Candida tropicalis, Escherichia coli, Prevotella sp., Aspergillus sp., Penicillium sp.. The ability of microorganisms to create a biofilm on the FFRs was confirmed using scanning electron microscopy (SEM. We also identified secondary metabolites in the biomass and FFRs, including fumigaclavines, quinocitrinines, sterigmatocistin, and 3-nitropropionic acid, which may be toxic to humans. Due to the presence of potential pathogens and mycotoxins, the level of microbiological contamination at workplaces in CHPs should be monitored.

Unit commitment with probabilistic reserve: An IPSO approach

International Nuclear Information System (INIS)

Lee, Tsung-Ying; Chen, Chun-Lung

2007-01-01

This paper presents a new algorithm for solution of the nonlinear optimal scheduling problem. This algorithm is named the iteration particle swarm optimization (IPSO). A new index, called iteration best, is incorporated into particle swarm optimization (PSO) to improve the solution quality and computation efficiency. IPSO is applied to solve the unit commitment with probabilistic reserve problem of a power system. The outage cost as well as fuel cost of thermal units was considered in the unit commitment program to evaluate the level of spinning reserve. The optimal scheduling of on line generation units was reached while minimizing the sum of fuel cost and outage cost. A 48 unit power system was used as a numerical example to test the new algorithm. The optimal scheduling of on line generation units could be reached in the testing results while satisfying the requirement of the objective function

Production planning of combined heat and power plants with regards to electricity price spikes : A machine learning approach

OpenAIRE

Fransson, Nathalie

2017-01-01

District heating systems could help manage the expected increase of volatility on the Nordic electricity market by starting a combined heat and power production plant (CHP) instead of a heat only production plant when electricity prices are expected to be high. Fortum Värme is interested in adjusting the production planning of their district heating system more towards high electricity prices and in their system there is a peak load CHP unit that could be utilised for this purpose. The econom...

Combined Heat and Power in an open market

International Nuclear Information System (INIS)

Hawkins, A.

1999-01-01

The chances and risks for combined heat and power (CHP) installations presented by the future liberalisation of the electricity market in Switzerland are discussed. A summary of papers and speeches presented at a conference in Basle is presented. New developments in the electricity marketplace are looked at from the point of view of CHP unit manufacturers, the Federal Administration, energy policy makers and marketing experts. Examples are quoted concerning the situation in Germany and possible changes in power generation philosophy

Operating Experiences with a Small-scale CHP Pilot Plant based on a 35 kWel Hermetic Four Cylinder Stirling Engine for Biomass Fuels

DEFF Research Database (Denmark)

Biedermann, F.; Carlsen, Henrik; Schoech, M.

2003-01-01

Within the scope of the RD&D project presented a small-scale CHP plant with a hermetic four cylinder Stirling engine for biomass fuels was developed and optimised in cooperation with the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GesmbH, an Austrian biomass furnace and boiler...... exchanger of the Stirling engine, of the air preheater and of the entire combustion system. Furthermore, the optimisation of the pneumatic cleaning system to reduce ash deposition in the hot heat exchanger is of great relevance....... manufacturer, and BIOS BIOENERGIESYSTEME GmbH, an Austrian development and engineering company. Based on the technology developed, a pilot plant was designed and erected in Austria. The nominal electric power output of the plant is 35 kWel and the nominal thermal output amounts to approx. 220 kWth. The plant...

SpecOp: Optimal Extraction Software for Integral Field Unit Spectrographs

Science.gov (United States)

McCarron, Adam; Ciardullo, Robin; Eracleous, Michael

2018-01-01

The Hobby-Eberly Telescope’s new low resolution integral field spectrographs, LRS2-B and LRS2-R, each cover a 12”x6” area on the sky with 280 fibers and generate spectra with resolutions between R=1100 and R=1900. To extract 1-D spectra from the instrument’s 3D data cubes, a program is needed that is flexible enough to work for a wide variety of targets, including continuum point sources, emission line sources, and compact sources embedded in complex backgrounds. We therefore introduce SpecOp, a user-friendly python program for optimally extracting spectra from integral-field unit spectrographs. As input, SpecOp takes a sky-subtracted data cube consisting of images at each wavelength increment set by the instrument’s spectral resolution, and an error file for each count measurement. All of these files are generated by the current LRS2 reduction pipeline. The program then collapses the cube in the image plane using the optimal extraction algorithm detailed by Keith Horne (1986). The various user-selected options include the fraction of the total signal enclosed in a contour-defined region, the wavelength range to analyze, and the precision of the spatial profile calculation. SpecOp can output the weighted counts and errors at each wavelength in various table formats using python’s astropy package. We outline the algorithm used for extraction and explain how the software can be used to easily obtain high-quality 1-D spectra. We demonstrate the utility of the program by applying it to spectra of a variety of quasars and AGNs. In some of these targets, we extract the spectrum of a nuclear point source that is superposed on a spatially extended galaxy.

Optimized 4-bit Quantum Reversible Arithmetic Logic Unit

Science.gov (United States)

Ayyoub, Slimani; Achour, Benslama

2017-08-01

Reversible logic has received a great attention in the recent years due to its ability to reduce the power dissipation. The main purposes of designing reversible logic are to decrease quantum cost, depth of the circuits and the number of garbage outputs. The arithmetic logic unit (ALU) is an important part of central processing unit (CPU) as the execution unit. This paper presents a complete design of a new reversible arithmetic logic unit (ALU) that can be part of a programmable reversible computing device such as a quantum computer. The proposed ALU based on a reversible low power control unit and small performance parameters full adder named double Peres gates. The presented ALU can produce the largest number (28) of arithmetic and logic functions and have the smallest number of quantum cost and delay compared with existing designs.

Investments in the LNG Value Chain: A Multistage Stochastic Optimization Model focusing on Floating Liquefaction Units

OpenAIRE

Røstad, Lars Dybsjord; Erichsen, Jeanette Christine

2012-01-01

In this thesis, we have developed a strategic optimization model of investments in infrastructure in the LNG value chain. The focus is on floating LNG production units: when they are a viable solution and what value they add to the LNG value chain. First a deterministic model is presented with focus on describing the value chain, before it is expanded to a multistage stochastic model with uncertain field sizes and gas prices. The objective is to maximize expected discounted profits through op...

Directional Convexity and Finite Optimality Conditions.

Science.gov (United States)

1984-03-01

system, Necessary Conditions for optimality. Work Unit Number 5 (Optimization and Large Scale Systems) *Istituto di Matematica Applicata, Universita...that R(T) is convex would then imply x(u,T) e int R(T). Cletituto di Matematica Applicata, Universita di Padova, 35100 ITALY. Sponsored by the United

Is the Korean public willing to pay for a decentralized generation source? The case of natural gas-based combined heat and power

International Nuclear Information System (INIS)

Kim, Hyo-Jin; Lim, Seul-Ye; Yoo, Seung-Hoon

2017-01-01

Natural gas (NG)-based combined heat and power (CHP) plants can be installed near electricity-consuming areas and do not require large-scale and long-distance power transmission facilities. This paper attempts to assess the public's additional willingness to pay (WTP) for substituting consumption of a unit of electricity generated from nuclear power plant, currently a dominant power generation source in Korea, with that produced from NG-based CHP plant in terms of decentralized generation using the contingent valuation (CV) method. To this end, a CV survey of 1,000 households was implemented. The results show that the mean additional WTP for substituting nuclear power plant by NG-based CHP plant is estimated to be KRW 55.3 (USD 0.047) per kWh of electricity, which is statistically significant at the 1% level. This value amounts to 44.7% of the average price for electricity, KRW 123.69 (USD 0.106) in 2015, which implies that the public are ready to shoulder a significant financial burden to achieve the substitution. Moreover, the value can be interpreted as an external cost of nuclear power generation relative to NG-based CHP generation, or as an external benefit of NG-based CHP generation relative to nuclear power generation with a view to decentralized generation. - Highlights: • Combined heat and power (CHP) is a representative decentralized generation source. • Nuclear power requires large-scale and long-distance power transmission facilities. • We assess people's additional willingness to pay (WTP) for CHP over nuclear power. • We conduct a contingent valuation survey of 1,000 households in Korea. • The mean additional WTP amounts to 44.2% of the average price for electricity.

Ultra Clean 1.1MW High Efficiency Natural Gas Engine Powered System

Energy Technology Data Exchange (ETDEWEB)

Zurlo, James; Lueck, Steve

2011-08-31

Dresser, Inc. (GE Energy, Waukesha gas engines) will develop, test, demonstrate, and commercialize a 1.1 Megawatt (MW) natural gas fueled combined heat and power reciprocating engine powered package. This package will feature a total efficiency > 75% and ultra low CARB permitting emissions. Our modular design will cover the 1 – 6 MW size range, and this scalable technology can be used in both smaller and larger engine powered CHP packages. To further advance one of the key advantages of reciprocating engines, the engine, generator and CHP package will be optimized for low initial and operating costs. Dresser, Inc. will leverage the knowledge gained in the DOE - ARES program. Dresser, Inc. will work with commercial, regulatory, and government entities to help break down barriers to wider deployment of CHP. The outcome of this project will be a commercially successful 1.1 MW CHP package with high electrical and total efficiency that will significantly reduce emissions compared to the current central power plant paradigm. Principal objectives by phases for Budget Period 1 include: • Phase 1 – market study to determine optimum system performance, target first cost, lifecycle cost, and creation of a detailed product specification. • Phase 2 – Refinement of the Waukesha CHP system design concepts, identification of critical characteristics, initial evaluation of technical solutions, and risk mitigation plans. Background

The concept of system for chips production need to work demo CHP plant in company 'AGROSAVA' from Šimanovci

Directory of Open Access Journals (Sweden)

Dedić Aleksandar Đ.

2014-01-01

Full Text Available In this paper according to the calculation of chips productivity needs for gasification in the demo CHP plant for co-generation: electricity and heat, chippers were analyzed due to: the type of mobility, running for chipping and the method of delivering chips to temporary yard. The plant was planned to generate electricity power up to 200kWelec. First, in consideration were taken the chippers with medium capacity, which mainly served for chipping brushwood and leaves that remain after harvest plantations on mostly flat terrain and parks. Later, the comparative characteristics of the world's three largest manufacturers of machinery for the production of wood chips significantly larger amounts (up to 30m3/h were given. These chippers were particularly suitable for the higher density of crops and stationed yard, in which brushwood would be brought and chip. At the end, the types of convective dryers were analyzed that could be successfully used for drying wood chips (drum and pneumatic dryer and based on the calculation proposed the types of dryers that were available in the local market.

Joint optimisation of the future Danish waste and energy system

DEFF Research Database (Denmark)

Münster, Marie; Pizarro, Amalia Rosa; Salvucci, Raffaele

2015-01-01

in future scenarios with higher biomass consumption, where the average heat prices are higher. In both scenarios, biogas produced from organic waste is upgraded and fed into the natural gas grid and waste is incinerated rather than being centrally sorted in a material recovery facility.......In this article the impact of the future development of the energy system on the feasibility of waste treatment options is analysed. In the article two different optimization tools are used: a regional electricity model (Balmorel) and a national waste treatment and district heating model (Opti......Waste). When performing optimization by minimizing the socio-economic costs, into future energy systems with high wind power production, it proves feasible primarily to incinerate waste in large scale combined heat and power (CHP) plants, whereas more incineration takes place in decentralized CHP plants...

Exergy analysis of a combined heat and power plant with integrated lignocellulosic ethanol production

DEFF Research Database (Denmark)

Lythcke-Jørgensen, Christoffer Ernst; Haglind, Fredrik; Clausen, Lasse Røngaard

2014-01-01

production. An exergy analysis is carried out for a modelled polygeneration system in which lignocellulosic ethanol production based on hydrothermal pretreatment is integrated in an existing combined heat and power (CHP) plant. The ethanol facility is driven by steam extracted from the CHP unit when feasible...... district heating production in the ethanol facility. The results suggest that the efficiency of integrating lignocellulosic ethanol production in CHP plants is highly dependent on operation, and it is therefore suggested that the expected operation pattern of such polygeneration system is taken......Lignocellulosic ethanol production is often assumed integrated in polygeneration systems because of its energy intensive nature. The objective of this study is to investigate potential irreversibilities from such integration, and what impact it has on the efficiency of the integrated ethanol...

Optimization of fermentation conditions for red pigment production ...

African Journals Online (AJOL)

An extracellular pigment-producing ascomycetous filamentous fungi belonging to the genera Penicillium was obtained from soil and its optimal culture conditions investigated. The optimal culture conditions for pigment production were as follows; soluble starch 2% (670 units), peptone (880 units), pH 9.0 (900 units); ...

Optimization model of a system of crude oil distillation units with heat integration and metamodeling

International Nuclear Information System (INIS)

Lopez, Diana C; Mahecha, Cesar A; Hoyos, Luis J; Acevedo, Leonardo; Villamizar Jaime F

2010-01-01

The process of crude distillation impacts the economy of any refinery in a considerable manner. Therefore, it is necessary to improve it taking good advantage of the available infrastructure, generating products that conform to the specifications without violating the equipment operating constraints or plant restrictions at industrial units. The objective of this paper is to present the development of an optimization model for a Crude Distillation Unit (CDU) system at a ECOPETROL S.A. refinery in Barrancabermeja, involving the typical restrictions (flow according to pipeline capacity, pumps, distillation columns, etc) and a restriction that has not been included in bibliographic reports for this type of models: the heat integration of streams from Atmospheric Distillation Towers (ADTs) and Vacuum Distillation Towers (VDT) with the heat exchanger networks for crude pre-heating. On the other hand, ADTs were modeled with Metamodels in function of column temperatures and pressures, pump a rounds flows and return temperatures, stripping steam flows, Jet EBP ASTM D-86 and Diesel EBP ASTM D-86. Pre-heating trains were modeled with mass and energy balances, and design equation of each heat exchanger. The optimization model is NLP, maximizing the system profit. This model was implemented in GAMSide 22,2 using the CONOPT solver and it found new operating points with better economic results than those obtained with the normal operation in the real plants. It predicted optimum operation conditions of 3 ADTs for constant composition crude and calculated the yields and properties of atmospheric products, additional to temperatures and duties of 27 Crude Oil exchangers.

A Benders decomposition approach for a combined heat and power economic dispatch

International Nuclear Information System (INIS)

Abdolmohammadi, Hamid Reza; Kazemi, Ahad

2013-01-01

Highlights: • Benders decomposition algorithm to solve combined heat and power economic dispatch. • Decomposing the CHPED problem into master problem and subproblem. • Considering non-convex heat-power feasible region efficiently. • Solving 4 units and 5 units system with 2 and 3 co-generation units, respectively. • Obtaining better or as well results in terms of objective values. - Abstract: Recently, cogeneration units have played an increasingly important role in the utility industry. Therefore the optimal utilization of multiple combined heat and power (CHP) systems is an important optimization task in power system operation. Unlike power economic dispatch, which has a single equality constraint, two equality constraints must be met in combined heat and power economic dispatch (CHPED) problem. Moreover, in the cogeneration units, the power capacity limits are functions of the unit heat productions and the heat capacity limits are functions of the unit power generations. Thus, CHPED is a complicated optimization problem. In this paper, an algorithm based on Benders decomposition (BD) is proposed to solve the economic dispatch (ED) problem for cogeneration systems. In the proposed method, combined heat and power economic dispatch problem is decomposed into a master problem and subproblem. The subproblem generates the Benders cuts and master problem uses them as a new inequality constraint which is added to the previous constraints. The iterative process will continue until upper and lower bounds of the objective function optimal values are close enough and a converged optimal solution is found. Benders decomposition based approach is able to provide a good framework to consider the non-convex feasible operation regions of cogeneration units efficiently. In this paper, a four-unit system with two cogeneration units and a five-unit system with three cogeneration units are analyzed to exhibit the effectiveness of the proposed approach. In all cases, the

Two Examples of Exergy Optimization Regarding the “Thermo-Frigopump” and Combined Heat and Power Systems

Directory of Open Access Journals (Sweden)

Michel Feidt

2013-02-01

Full Text Available In a recent review an optimal thermodynamics and associated new upper bounds have been proposed, but it was only relative to power delivered by engines. In fact, it appears that for systems and processes with more than one utility (mainly mechanical or electrical power, energy conservation (First Law is limited for representing their efficiency. Consequently, exergy analysis combining the First and Second Law seems essential for optimization of systems or processes situated in their environment. For thermomechanical systems recent papers report on comparisons between energy and exergy analysis and corresponding optimization, but the proposed models mainly use heat transfer conductance modelling, except for internal combustion engine. Here we propose to reconsider direct and inverse configurations of Carnot machines, with two examples. The first example is concerned with “thermofrigo-pump” where the two utilities are hot and cold thermal exergies due to the difference in the temperature level compared to the ambient one. The second one is relative to a “combined heat and power” (CHP system. In the two cases, the model is developed based on the Carnot approach, and use of the efficiency-NTU method to characterize the heat exchangers. Obtained results are original thermodynamics optima, that represent exergy upper bounds for these two cases. Extension of the proposed method to other systems and processes is examined, with added technical constraints or not.

Combined Heat and Power Market Potential for Opportunity Fuels

Energy Technology Data Exchange (ETDEWEB)

Jones, David [Resource Dynamics Corporation, McLean, VA (United States); Lemar, Paul [Resource Dynamics Corporation, McLean, VA (United States

2015-12-01

This report estimates the potential for opportunity fuel combined heat and power (CHP) applications in the United States, and provides estimates for the technical and economic market potential compared to those included in an earlier report. An opportunity fuel is any type of fuel that is not widely used when compared to traditional fossil fuels. Opportunity fuels primarily consist of biomass fuels, industrial waste products and fossil fuel derivatives. These fuels have the potential to be an economically viable source of power generation in various CHP applications.

Mathematical modelling and optimization of a large-scale combined cooling, heat, and power system that incorporates unit changeover and time-of-use electricity price

International Nuclear Information System (INIS)

Zhu, Qiannan; Luo, Xianglong; Zhang, Bingjian; Chen, Ying

2017-01-01

Highlights: • We propose a novel superstructure for the design and optimization of LSCCHP. • A multi-objective multi-period MINLP model is formulated. • The unit start-up cost and time-of-use electricity prices are involved. • Unit size discretization strategy is proposed to linearize the original MINLP model. • A case study is elaborated to demonstrate the effectiveness of the proposed method. - Abstract: Building energy systems, particularly large public ones, are major energy consumers and pollutant emission contributors. In this study, a superstructure of large-scale combined cooling, heat, and power system is constructed. The off-design unit, economic cost, and CO_2 emission models are also formulated. Moreover, a multi-objective mixed integer nonlinear programming model is formulated for the simultaneous system synthesis, technology selection, unit sizing, and operation optimization of large-scale combined cooling, heat, and power system. Time-of-use electricity price and unit changeover cost are incorporated into the problem model. The economic objective is to minimize the total annual cost, which comprises the operation and investment costs of large-scale combined cooling, heat, and power system. The environmental objective is to minimize the annual global CO_2 emission of large-scale combined cooling, heat, and power system. The augmented ε–constraint method is applied to achieve the Pareto frontier of the design configuration, thereby reflecting the set of solutions that represent optimal trade-offs between the economic and environmental objectives. Sensitivity analysis is conducted to reflect the impact of natural gas price on the combined cooling, heat, and power system. The synthesis and design of combined cooling, heat, and power system for an airport in China is studied to test the proposed synthesis and design methodology. The Pareto curve of multi-objective optimization shows that the total annual cost varies from 102.53 to 94.59 M

In-vitro Characterization of Optimized Multi-Unit Dosage Forms of ...

African Journals Online (AJOL)

The optimized formulation was characterized with Differential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy. Results showed that the optimized MU tablets gave dissolution profile that was comparable with that of the designed model. The following were the dissolution parameters of the optimized MU ...

Optimal unit sizing of a hybrid renewable energy system for isolated applications

International Nuclear Information System (INIS)

Morales, D.

2006-07-01

In general, the methods used to conceive a renewable energy production system overestimate the size of the generating units. These methods increase the investment cost and the production cost of energy. The work presented in this thesis proposes a methodology to optimally size a renewable energy system.- This study shows that the classic approach based only on a long term analysis of system's behaviour is not sufficient and a complementary methodology based on a short term analysis is proposed. A numerical simulation was developed in which the mathematical models of the solar panel, the wind turbines and battery are integrated. The daily average solar energy per m2 is decomposed into a series of hourly I energy values using the Collares-Pereira equations. The time series analysis of the wind speed is made using the Monte Carlo Simulation Method. The second part of this thesis makes a detailed analysis of an isolated wind energy production system. The average energy produced by the system depends on the generator's rated power, the total swept area of the wind turbine, the gearbox's transformation ratio, the battery voltage and the wind speed probability function. The study proposes a methodology to determine the optimal matching between the rated power of the permanent magnet synchronous machine and the wind turbine's rotor size. This is made taking into account the average electrical energy produced over a period of time. (author)

Research on Power System Scheduling Improving Wind Power Accommodation Considering Thermal Energy Storage and Flexible Load

Science.gov (United States)

Zou, Chenlu; Cui, Xue; Wang, Heng; Zhou, Bin; Liu, Yang

2018-01-01

In the case of rapid development of wind power and heavy wind curtailment, the study of wind power accommodation of combined heat and power system has become the focus of attention. A two-stage scheduling model contains of wind power, thermal energy storage, CHP unit and flexible load were constructed. This model with the objective function of minimizing wind curtailment and the operation cost of units while taking into account of the total coal consumption of units, constraint of thermal energy storage and electricity-heat characteristic of CHP. This paper uses MICA to solve the problem of too many constraints and make the solution more feasible. A numerical example showed that the two stage decision scheduling model can consume more wind power, and it could provide a reference for combined heat and power system short-term operation

Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

Directory of Open Access Journals (Sweden)

Zhihua Ge

2018-01-01

Full Text Available To reduce the exergy loss that is caused by the high-grade extraction steam of traditional heating mode of combined heat and power (CHP generating unit, a high back-pressure cascade heating technology for two jointly constructed large-scale steam turbine power generating units is proposed. The Unit 1 makes full use of the exhaust steam heat from high back-pressure turbine, and the Unit 2 uses the original heating mode of extracting steam condensation, which significantly reduces the flow rate of high-grade extraction steam. The typical 2 × 350 MW supercritical CHP units in northern China were selected as object. The boundary conditions for heating were determined based on the actual climatic conditions and heating demands. A model to analyze the performance of the high back-pressure cascade heating supply units for off-design operating conditions was developed. The load distributions between high back-pressure exhaust steam direct supply and extraction steam heating supply were described under various conditions, based on which, the heating efficiency of the CHP units with the high back-pressure cascade heating system was analyzed. The design heating load and maximum heating supply load were determined as well. The results indicate that the average coal consumption rate during the heating season is 205.46 g/kWh for the design heating load after the retrofit, which is about 51.99 g/kWh lower than that of the traditional heating mode. The coal consumption rate of 199.07 g/kWh can be achieved for the maximum heating load. Significant energy saving and CO2 emission reduction are obtained.

The effect of fault ride-through requirements on voltage dips and post-fault voltage recovery in a Dutch distribution network

NARCIS (Netherlands)

Karaliolios, P.; Coster, E.J.; Slootweg, J.G.; Kling, W.L.

2010-01-01

In this paper the possibility to use Decentralized Generation (DG) units for voltage support in Distribution Networks during and after a Short Circuit (S/C) event is discussed. Two types of DG units will be examined, Combined Heat-Power (CHP) plants and Doubly-Fed Induction Generators (DFIG).

Integration issues of distributed generation in distribution grids

NARCIS (Netherlands)

Coster, E.J.; Myrzik, J.M.A.; Kruimer, B.; Kling, W.L.

2011-01-01

In today’s distribution grids the number of distributed generation (DG) units is increasing rapidly. Combined heat and power (CHP) plants and wind turbines are most often installed. Integration of these DG units into the distribution grid leads to planning as well as operational challenges. Based on

Financial stability, wealth effects and optimal macroeconomic policy combination in the United Kingdom: A new-Keynesian dynamic stochastic general equilibrium framework

Directory of Open Access Journals (Sweden)

Muhammad Ali Nasir

2016-12-01

Full Text Available This study derives an optimal macroeconomic policy combination for financial sector stability in the United Kingdom by employing a New Keynesian Dynamic Stochastic General Equilibrium (NK-DSGE framework. The empirical results obtained show that disciplined fiscal and accommodative monetary policies stance is optimal for financial sector stability. Furthermore, fiscal indiscipline countered by contractionary monetary stance adversely affects financial sector stability. Financial markets, e.g. stocks and Gilts show a short-term asymmetric response to macroeconomic policy interaction and to each other. The asymmetry is a reflection of portfolio adjustment. However in the long-run, the responses to suggested optimal policy combination had homogenous effects and there was evidence of co-movement in the stock and Gilt markets.

Modelling and control synthesis of a micro-combined heat and power interface for a concentrating solar power system in off-grid rural power applications

Science.gov (United States)

Prinsloo, Gerro; Dobson, Robert; Brent, Alan; Mammoli, Andrea

2016-05-01

Concentrating solar power co-generation systems have been identified as potential stand-alone solar energy supply solutions in remote rural energy applications. This study describes the modelling and synthesis of a combined heat and power Stirling CSP system in order to evaluate its potential performance in small off-grid rural village applications in Africa. This Stirling micro-Combined Heat and Power (micro-CHP) system has a 1 kW electric capacity, with 3 kW of thermal generation capacity which is produced as waste heat recovered from the solar power generation process. As part of the development of an intelligent microgrid control and distribution solution, the Trinum micro-CHP system and other co-generation systems are systematically being modelled on the TRNSYS simulation platform. This paper describes the modelling and simulation of the Trinum micro-CHP configuration on TRNSYS as part of the process to develop the control automation solution for the smart rural microgrid in which the Trinum will serve as a solar powerpack. The results present simulated performance outputs for the Trinum micro-CHP system for a number of remote rural locations in Africa computed from real-time TRNSYS solar irradiation and weather data (yearly, monthly, daily) for the relevant locations. The focus of this paper is on the parametric modelling of the Trinum Stirling micro-CHP system, with specific reference to this system as a TRNSYS functional block in the microgrid simulation. The model is used to forecast the solar energy harvesting potential of the Trinum micro-CHP unit at a number of remote rural sites in Africa.

Market optimization of a cluster of DG-RES, micro-CHP, heat pumps and energy storage within network constraints: The Power Matching City field test

Energy Technology Data Exchange (ETDEWEB)

Bliek, F.W.; Van den Noort, A. [KEMA, Arnhem (Netherlands); Roossien, B.; Kamphuis, I.G. [ECN Efficiency and Infrastructure, Petten (Netherlands); De Wit, J.; Van de Velde, J. [HumiQ, Barendrecht (Netherlands); Eijgelaar, M. [Essent, Arnhem (Netherlands)

2010-10-15

The share of renewable energy resources for electricity production, in a distributed setting (DG-RES), increases. The amount of energy transported via the electricity grid by substitution of fossil fuels for mobility applications (electric vehicles) and domestic heating (heat pumps) increases as well. Apart from the volume of electricity also the simultaneity factor increases at all grid levels. This poses unprecedented challenges to capacity management of the electricity infrastructure. A solution for tackling this challenge is using more active distribution networks, intelligent coordination of supply and demand using ICT and using the gas distribution network to mitigate electricity distribution bottlenecks. In the EU FP6 Energy Program Integral project, a large scale heterogeneous field test has been designed for application of the software agent based PowerMatcher technology. The test is conducted in a suburb of Groningen, Hoogkerk, and entails approximately 30 homes with either a 'dual fuel' heating system (electrical heat pump with gas-fired peak-burners) or a micro-CHP. Homes also may have PV. Furthermore, a wind production facility and nodes with electricity chargers for EVs and electricity storage are part of the Virtual Power Plant cluster, constructed in this way. Domestic heating systems have intrinsic operational flexibility in comfort management through the thermal mass of the dwellings. Furthermore, the field test comfort systems are equipped with possibilities for hot water storage for central heating as well as for tap-water. Finally, having additional gas-fired heating capacity for electrical heat pumps adds to increasing flexibility by switching the energy source dependent on the status of the electricity grid. Purpose of the field test is using this flexibility to react to phenomena in the electricity system. From a commercial perspective, the aggregated cluster reacts on small-time scale events like real-time portfolio imbalance

Environmental implications of carbon limits on market ...

Science.gov (United States)

Combined heat and power (CHP) is promoted as an economical, energy-efficient option for combating climate change. To fully examine the viability of CHP as a clean-technology solution, its market potential and impacts need to be analyzed as part of scenarios of the future energy system, particularly those with policies limiting greenhouse gas (GHG) emissions. This paper develops and analyzes scenarios using a bottom-up, technology rich optimization model of the U.S. energy system. Two distinct carbon reduction goals were set up for analysis. In Target 1, carbon emission reduction goals were only included for the electric sector. In Target 2, carbon emission reduction goals were set across the entire energy system with the target patterned after the U.S.’s commitment to reducing GHG emissions as part of the Paris Agreement reached at the COP21 summit. From a system-wide carbon reduction standpoint, Target 2 is significantly more stringent. In addition, these scenarios examine the implications of various CHP capacity expansion and contraction assumptions and energy prices. The largest CHP capacity expansion are observed in scenarios that included Target 1, but investments were scaled back in scenarios that incorporated Target 2. The latter scenario spurred rapid development of zero-emissions technologies within the electric sector, and purchased electricity increased dramatically in many end-use sectors. The results suggest that CHP may play a role in a carbon-c

An Integrated GIS, optimization and simulation framework for optimal PV size and location in campus area environments

International Nuclear Information System (INIS)

Kucuksari, Sadik; Khaleghi, Amirreza M.; Hamidi, Maryam; Zhang, Ye; Szidarovszky, Ferenc; Bayraksan, Guzin; Son, Young-Jun

2014-01-01

Highlights: • The optimal size and locations for PV units for campus environments are achieved. • The GIS module finds the suitable rooftops and their panel capacity. • The optimization module maximizes the long-term profit of PV installations. • The simulation module evaluates the voltage profile of the distribution network. • The proposed work has been successfully demonstrated for a real university campus. - Abstract: Finding the optimal size and locations for Photovoltaic (PV) units has been a major challenge for distribution system planners and researchers. In this study, a framework is proposed to integrate Geographical Information Systems (GIS), mathematical optimization, and simulation modules to obtain the annual optimal placement and size of PV units for the next two decades in a campus area environment. First, a GIS module is developed to find the suitable rooftops and their panel capacity considering the amount of solar radiation, slope, elevation, and aspect. The optimization module is then used to maximize the long-term net profit of PV installations considering various costs of investment, inverter replacement, operation, and maintenance as well as savings from consuming less conventional energy. A voltage profile of the electricity distribution network is then investigated in the simulation module. In the case of voltage limit violation by intermittent PV generations or load fluctuations, two mitigation strategies, reallocation of the PV units or installation of a local storage unit, are suggested. The proposed framework has been implemented in a real campus area, and the results show that it can effectively be used for long-term installation planning of PV panels considering both the cost and power quality

Solving unit commitment and economic load dispatch problems ...