Economic Optimization of a Combined Heat and Power System for an Office Building

2007 ◽  
Author(s):  
M. E. Douglas ◽  
Timothy C. Wagner ◽  
Michael K. Sahm ◽  
William J. Wepfer
Keyword(s):  
Thermal Energy ◽  
Waste Heat ◽  
Cost Effective ◽  
Energy Generation ◽  
Prime Mover ◽  
Economic Optimization ◽  
Electrical Efficiency ◽  
Load Demand ◽  
Generation Cost ◽  
The Relationship

The determination of a prime mover’s characteristics is important in ascertaining its suitability for combined heat and power (CHP) applications. By definition, its operation affects the operation of all heat recovery equipment downstream. The correct balance between component electrical efficiency and waste heat is needed if the electric power producing equipment is to be used in a CHP application in a cost effective manner. Understanding the relationship between electric efficiency and exhaust stream energy content for different prime movers systems is a first step in an overall CHP system optimization. The goals of this work are to determine the potential financial benefit of utilizing waste heat from various prime mover configurations as well as establish the relationship between the two types of energy generation and costs. An economic optimization was performed to determine the system with the lowest average product (electricity and thermal energy) generation cost. The prime mover system was required to meet the electrical load demand of a typical 9290 m2 (100,000 ft2) office building in New York, NY, USA. The composition of the most cost effective prime mover system, when considering both electrical and thermal energy generation, was shown to be a single microturbine. When comparing the electrical and thermal energy generation of all systems studied with product generation cost, the more cost effective systems had either high electrical efficiency with a low thermal energy generation or high amounts of waste heat with low electrical efficiency. Each installation site and load demand is unique. The results of this study, along with others, can be used to help determine a cost effective system for a particular application.

Thermal Management Using Free Liquid Jet Impingement From a Slot Nozzle to a Curved Plate

2007 ◽  
Author(s):  
Muhammad M. Rahman ◽  
Cesar F. Hernandez
Keyword(s):  
Thermal Energy ◽  
Waste Heat ◽  
Cost Effective ◽  
Energy Generation ◽  
System Optimization ◽  
Prime Mover ◽  
Electrical Efficiency ◽  
Load Demand ◽  
Generation Cost ◽  
The Relationship

The determination of a prime mover’s characteristics is important in ascertaining its suitability for combined heat and power (CHP) applications. By definition, its operation affects the operation of all heat recovery equipment downstream. The correct balance between component electrical efficiency and waste heat is needed if the electric power producing equipment is to be used in a CHP application in a cost effective manner. Understanding the relationship between electric efficiency and exhaust stream energy content for different prime movers systems is a first step in an overall CHP system optimization. The goals of this work are to determine the potential financial benefit of utilizing waste heat from various prime mover configurations as well as establish the relationship between the two types of energy generation and costs. An economic optimization was performed to determine the system with the lowest average product (electricity and thermal energy) generation cost. The prime mover system was required to meet the electrical load demand of a typical 9290 m2 (100,000 ft2) office building in New York, NY, USA. The composition of the most cost effective prime mover system, when considering both electrical and thermal energy generation, was shown to be a single microturbine. When comparing the electrical and thermal energy generation of all systems studied with product generation cost, the more cost effective systems had either high electrical efficiency with a low thermal energy generation or high amounts of waste heat with low electrical efficiency. Each installation site and load demand is unique. The results of this study, along with others, can be used to help determine a cost effective system for a particular application.

Considerations on Economic Optimization of the Relationship Insulation - Thermal Energy Sources Insurance for Civil Building

2014 ◽  
Vol 659 ◽  
pp. 463-468
Author(s):  
Adrian Alexandru Şerbănoiu ◽  
Gabriel Teodoriu ◽  
Bogdan Serbanoiu ◽  
Ion Serbanoiu ◽  
Marina Verdeș ◽  
...  
Keyword(s):  
Energy Source ◽  
Renewable Energy ◽  
Thermal Energy ◽  
Renewable Energy Sources ◽  
Building Envelope ◽  
Energy Sources ◽  
Economic Optimization ◽  
Major Objective ◽  
Financial Perspective ◽  
The Relationship

The major objective of this paper is to optimize the relationship insurance energy source - high thermal insulation of the building envelope analyzed in order to minimize the financial effort incurred by the beneficiary. In this respect, the paper proposes a methodology for analyzing the financial perspective of the relation envelope - equipment that capitalizes renewable energy sources, built on a newer concept - optimal cost.

Comparative Performance Analysis of IADR Operating in Natural Gas-Fired and Waste-Heat CHP Modes

2006 ◽  
Author(s):  
Andrei Y. Petrov ◽  
James R. Sand ◽  
Abdolreza Zaltash ◽  
John Fischer ◽  
Rick Mitchell
Keyword(s):  
Natural Gas ◽  
Thermal Energy ◽  
Waste Heat ◽  
Cooling System ◽  
Cost Effective ◽  
Direct Expansion ◽  
Comparative Performance ◽  
Desiccant Wheel ◽  
Absorption Chillers ◽  
Expansion Cooling

Fuel utilization can be dramatically improved through effective recycle of "waste" heat produced as a by-product of on-site or near-site power generation technologies. Development of modular compact cooling, heating, and power (CHP) systems for end-use applications in commercial and institutional buildings is a key part of the Department of Energy's (DOE) energy policy. To effectively use the thermal energy from a wide variety of sources which is normally discarded to the ambient, many components such as heat exchangers, boilers, absorption chillers, and desiccant dehumidification systems must be further developed. Recently a compact, cost-effective, and energy-efficient integrated active-desiccant vapor-compression hybrid rooftop (IADR) unit has been introduced in the market. It combines the advantages of an advanced direct-expansion cooling system with the dehumidification capability of an active desiccant wheel. The aim of this study is to compare the efficiency of the IADR operation in baseline mode, when desiccant wheel regeneration is driven by a natural gas burner, and in CHP mode, when the waste heat recovered from microturbine exhaust gas is used for desiccant regeneration. Comparative analysis shows an excellent potential for more efficient use of the desiccant dehumidification as part of a CHP system and the importance of proper sizing of the CHP components. The most crucial factor in exploiting the efficiency of this application is the maximum use of thermal energy recovered for heating of regeneration air.

Solar–Hydrogen Energy System: The Choice of the Future

1991 ◽  
Vol 18 (4) ◽  
pp. 304-312 ◽  
Author(s):  
T. Nejat Veziroglu ◽  
Frano Barbir
Keyword(s):  
Thermal Energy ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Cost Effective ◽  
Energy Generation ◽  
Energy System ◽  
Production Costs ◽  
Hydrogen Energy ◽  
Fuel System ◽  
Solar Hydrogen

As a result of the foregoing study, the following conclusions are reached: (A) The solar–hydrogen energy system is environmentally far more compatible than the fossil-fuel system; it is actually the only solution for the carbon-dioxide-induced ‘greenhouse’ effect and its threatening consequences. (B) The utilization efficiencies of hydrogen are greater than those of fossil and synthetic fossil fuels; therefore, in the hydrogen-energy system, less energy will be required to perform the same services. (C) The solar-hydrogen energy system is the most cost-effective system if effective costs (the costs which society pays for the energy services) are taken into account. It is not only more cost-effective than the synthetic fossil-fuel system—it is even more cost-effective than the present fossil-fuel system. (D) Clean coal technologies could be used for thermal-energy generation, satisfying approximately 30% of the world's total energy needs. Such a system, which employs coal for thermal-energy generation, and hydrogen from renewable energy sources in electricity generation and transportation sectors, would be the least-cost energy system for the transition period. (E) Transition to the solar–hydrogen energy system could help to save our economy and our planet.The fuels that are being most favourably considered for the post-petroleum and natural-gas era, namely hydrogen (both gaseous and liquid) and coal and coal-derived synthetic fluid fossil-fuels, have been compared in this paper by taking into account production costs, external costs, and utilization efficiencies. The results show that hydrogen is a much more cost-effective energy carrier than coal or synthetic fossil-fuels. At the same time, and most importantly by far from our viewpoint, it is the most environmentally compatible of all.

scholarly journals Design and optimization of grid Integrated hybrid on-site energy generation system for rural area in AJK-Pakistan using HOMER software

AIMS Energy ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1113-1135
Author(s):  
Muti Ur Rehman Tahir ◽  
◽  
Adil Amin ◽  
Ateeq Ahmed Baig ◽  
Sajjad Manzoor ◽  
...  
Keyword(s):  
System Design ◽  
Operating Cost ◽  
Cost Effective ◽  
Energy Generation ◽  
Flow Speed ◽  
Total Load ◽  
Design And Optimization ◽  
Available Energy ◽  
Load Demand ◽  
Fuel Costs

<abstract> <p>Power sector plays a crucial role in the development of a country. Rise in population and industrial expansion in developing countries are reason to burdenize the central grid. Pakistan is a country in its developing stages. About 58% of its total energy generation is contributed by fossil fuel based conventional plants for which the fuel costs plenteous amount. In these circumstances it is indispensable to exploit naturally available renewable resources for electricity generation. This study proposes a hybrid hydro-kinetic/Photovoltaic/Biomass system integrated with grid to serve electricity in a residential area of district Kotli in AJK Pakistan. By evaluating available resources and total load demand data of residential consumers, a system design is modelled in HOMER to get techno-economic and optimal design analysis of the purposed system. Using several configurations and combinations of available energy generation systems and then by comparing their results, the most optimum system design is achieved in terms of initial cost, operating cost, cost per unit and net present cost of the system. To further refine the results, the effect of variations of different parameters like load demand, water flow speed and solar irradiance on system is investigated by performing sensitivity analysis on the system. Final results demonstrate that the purposed system is cost-effective and efficient to meet the load demand.</p> </abstract>

Pound Wise and Penny Foolish? Weight Loss and The Dynamics of Health Care Spending

2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch
Keyword(s):  
Weight Loss ◽  
Cost Savings ◽  
Cost Effective ◽  
Economic Consequences ◽  
Health Care Spending ◽  
Order Of Magnitude ◽  
Dynamic Measures ◽  
The Cost ◽  
The Impact ◽  
The Relationship

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.

scholarly journals PSVII-3 Correlations between L-lactate concentrations obtained using a handheld lactate analyser and a lactate assay colorimetric kit in beef cattle transported by road

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 296-297
Author(s):  
Daniela M Meléndez ◽  
Sonia Marti ◽  
Luigi Faucitano ◽  
Derek B Haley ◽  
Timothy D Schwinghamer ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Cost Effective ◽  
Road Transportation ◽  
Long Distance ◽  
Suitable Alternative ◽  
Blood Samples ◽  
Handheld Device ◽  
Time Points ◽  
Relationship Of ◽  
The Relationship

Abstract Blood metabolites are used to assess a variety of animal conditions for veterinary diagnosis and research. Concentration of metabolites in blood can be measured using a commercially-available lab-based assay or in real-time using a handheld device developed to be more time- and cost-effective than the lab-based method. Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer (Lactate Scout, EFK Diagnostics, Barleben, Germany) and a lactate assay colorimetric kit (Lactate Assay Kit, Cell Biolabs Inc., San Diego, CA). Blood samples were collected by venipuncture from 96 steers (245 ± 35.7 kg BW) prior to (L1) and after 36 h, and prior to and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in colorimetric analysis. Pearson correlations were calculated to determine the relationship between the experimental methods for the quantification of L-lactate concentrations. The strengths and levels of statistical significance of the correlation varied over the observed time points, r = -0.03, P = 0.75 (L1) to r = 0.75, P = &lt; 0.0001 (d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, P &lt; 0.001). Based on the experimental results, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay for measuring L-lactate in transported cattle, due to variability across sampling time points and weak correlation with the traditional enzymatic method.

Quantification of thermal energy generation in annular hyperbolic porous-finned heat sinks using inverse optimization

2021 ◽  
pp. 095440892110243
Author(s):  
Sagnik Pal ◽  
Ranjan Das
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Heat Generation ◽  
Thermal Energy ◽  
Inverse Method ◽  
Golden Section ◽  
Energy Generation ◽  
Heat Sinks ◽  
Search Technique ◽  
Golden Section Search

The present paper introduces an accurate numerical procedure to assess the internal thermal energy generation in an annular porous-finned heat sink from the sole assessment of surface temperature profile using the golden section search technique. All possible heat transfer modes and temperature dependence of all thermal parameters are accounted for in the present nonlinear model. At first, the direct problem is numerically solved using the Runge–Kutta method, whereas for predicting the prevailing heat generation within a given generalized fin domain an inverse method is used with the aid of the golden section search technique. After simplifications, the proposed scheme is credibly verified with other methodologies reported in the existing literature. Numerical predictions are performed under different levels of Gaussian noise from which accurate reconstructions are observed for measurement error up to 20%. The sensitivity study deciphers that the surface temperature field in itself is a strong function of the surface porosity, and the same is controlled through a joint trade-off among heat generation and other thermo-geometrical parameters. The present results acquired from the golden section search technique-assisted inverse method are proposed to be suitable for designing effective and robust porous fin heat sinks in order to deliver safe and enhanced heat transfer along with significant weight reduction with respect to the conventionally used systems. The present inverse estimation technique is proposed to be robust as it can be easily tailored to analyse all possible geometries manufactured from any material in a more accurate manner by taking into account all feasible heat transfer modes.

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