A MEMS turbopump for fuel delivery in small-scale power systems

Author(s):  
C. M. Waits ◽  
M. McCarthy ◽  
R. Ghodssi
Processes ◽  
2016 ◽  
Vol 4 (4) ◽  
pp. 54 ◽  
Author(s):  
Aikaterini Anastasopoulou ◽  
Sughosh Butala ◽  
Bhaskar Patil ◽  
John Suberu ◽  
Martin Fregene ◽  
...  

Author(s):  
Alex Frank ◽  
Peter Therkelsen ◽  
Miguel Sierra Aznar ◽  
Vi H. Rapp ◽  
Robert K. Cheng ◽  
...  

About 75% of the electric power generated by centralized power plants feeds the energy needs from the residential and commercial sectors. These power plants waste about 67% of primary energy as heat emitting 2 billion tons of CO2 per year in the process (∼ 38% of total US CO2 generated per year) [1]. A study conducted by the United States Department of Energy indicated that developing small-scale combined heat and power systems to serve the commercial and residential sectors could have a significant impact on both energy savings and CO2 emissions. However, systems of this scale historically suffer from low efficiencies for a variety of reasons. From a combustion perspective, at these small scales, few systems can achieve the balance between low emissions and high efficiencies due in part to the increasing sensitivity of the system to hydrodynamic and heat transfer effects. Addressing the hydrodynamic impact, the effects of downscaling on the flowfield evolution were studied on the low swirl burner (LSB) to understand if it could be adapted to systems at smaller scales. Utilizing particle image velocimetry (PIV), three different swirlers were studied ranging from 12 mm to 25.4 mm representing an output range of less than 1 kW to over 23 kW. Results have shown that the small-scale burners tested exhibited similar flowfield characteristics to their larger-scale counterparts in the non-reacting cases studied. Utilizing this data, as a proof of concept, a 14 mm diameter LSB with an output of 3.33 kW was developed for use in microturbine operating on a recuperated Brayton cycle. Emissions results from this burner proved the feasibility of the system at sufficiently lean mixtures. Furthermore, integration of the newly developed LSB into a can style combustor for a microturbine application was successfully completed and comfortably meet the stringent emissions targets. While the analysis of the non-reacting cases was successful, the reacting cases were less conclusive and further investigation is required to gain an understanding of the flowfield evolution which is the subject of future work.


2020 ◽  
Vol 12 (5) ◽  
pp. 1793 ◽  
Author(s):  
Alexandros Korkovelos ◽  
Hisham Zerriffi ◽  
Mark Howells ◽  
Morgan Bazilian ◽  
H-Holger Rogner ◽  
...  

Achieving universal access to electricity by 2030 is a key part of the Agenda for Sustainable Development, and has its own Sustainable Development Goal, SDG 7.1. This is because electricity services are required for almost all aspects of a modern economy, from the cooling of vaccines to irrigation pumping, to manufacturing and running a business. The achievement of SDG 7.1 will require a thoughtful mix of policy, finance, and technology to be designed and implemented at scale. Yet, the pressing need for an electrification ramp-up is not unprecedented. Many countries (now considered “industrialized”) faced similar challenges about a century ago. Although the existing literature covers a great deal of power systems evolution, there is a gap around the specific role and impact of small, isolated power systems in the early stages of electricity uptake. In this paper, we provide insights based on the review of the historical electrification efforts in four (now middle and high-income) countries. The drivers and context of electrification efforts in early stages are described. Those focus particularly on the role of dispersed, small-scale generation systems (mini-grids). Our analysis shows that electrification follows four loosely defined phases, namely: pilot projects, technological roll-out, economic expansion, and social scale-up. We report a selection of historical mistakes and advances that offer lessons of striking importance for today´s energy access efforts, particularly in regards to the development of mini-grids. We find that today, as historically, multi-stakeholder (e.g., planners, regulators, developers, investors, third party actors) collaboration is key and can help build locally adaptable, economically sustainable and community compatible mini-grids that can accelerate—and lower the societal costs of—universal access to electricity.


Author(s):  
Colin F. McDonald

This paper has been written exactly 50 years after the first disclosure of a closed-cycle gas turbine concept with a simplistic uranium heater. Clearly, this plant was ahead of its time in terms of technology readiness, and the closed-cycle gas turbine was initially deployed in a cogeneration mode burning dirty fuels (e.g., coal, furnace gases). In the 1950s through the mid 1980s about 20 of these plants operated providing electrical power and district heating for European cities. The basic concept of a nuclear gas turbine plant was demonstrated in the USA on a small scale in 1961 with a mobile closed-cycle nitrogen gas turbine [330 KW(e)] coupled with a nuclear reactor. In the last three decades, closed-cycle gas turbine research and development, particularly in the U.S. has focused on space power systems, but today the utility size gas turbine-modular helium reactor (GT-MHR) is on the verge of being realized. The theme of this paper traces the half century of closed-cycle gas turbine evolution, and discusses the recent enabling technologies (e.g., magnetic bearings, compact recuperator) that now make the GT-MHR close to realization. The author would like to dedicate this paper to the late Professor Curt Keller who in 1935 filed the first closed-cycle gas turbine patent in Switzerland, and who exactly 50 years ago, first described a power plant involving the coupling of a helium gas turbine with a uranium heater.


2019 ◽  
Vol 112 ◽  
pp. 02011
Author(s):  
Cristian-Gabriel Alionte ◽  
Daniel-Constantin Comeaga

The importance of renewable energy and especially of eolian systems is growing. For this reason, we propose the investigation of an important pollutant - the noise, which has become so important that European Commission and European Parliament introduced Directive 2002/49/CE relating to the assessment and management of environmental noise. So far, priority has been given to very large-scale systems connected to national energy systems, wind farms whose highly variable output power could be regulated by large power systems. Nowadays, with the development of small storage capacities, it is feasible to install small power wind turbines in cities of up to 10,000 inhabitants too. As a case study, we propose a simulation for a rural locality where individual wind units could be used. This specific case study is interesting because it provides a new perspective of the impact of noise on the quality of life when the use of this type of system is implemented on a large scale. This option, of distributed and small power wind turbine, can be implemented in the future as an alternative or an adding to the common systems.


Author(s):  
Mehdi Aghaei Meybodi ◽  
Masud Behnia

Microturbines are ideally suited for distributed generation applications due to their flexibility in connection methods. They can be stacked in parallel for larger loads and provide stable and reliable power generation. One of the main applications of microturbines is operating as the prime mover in a combined heat and power (CHP) system. CHP systems are considered to be one of the best ways to produce heat and power with efficient fossil fuel consumption. Further, these systems emit less pollution compared to separate productions of the same amount of electricity and heat. In order to optimally benefit from combined heat and power systems, the proper sizing of prime movers is of paramount importance. This paper presents a technical-economic method for selecting the optimum number and nominal power as well as planning the operational strategy of microturbines as the prime movers of small scale combined heat and power systems (capacities up to 500 kW) in three modes of operation: one-way connection (OWC) mode, two-way connection (TWC) mode, and heat demand following (HDF) mode. In the proposed sizing procedure both performance characteristics of the prime mover and economic parameters (i.e. capital and maintenance costs) are taken into account. As the criterion for decision making Net Present Worth (NPW) is used. In our analysis we have also considered the impact of carbon tax on the economics of generation. The proposed approach may also be used for other types of prime movers as well as other sizes of CHP system.


Author(s):  
Amy Bilton ◽  
Leah Kelley ◽  
Francesco Mazzini

Electrification of remote areas in the developing world can greatly improve the health and economic standing of the population. Unfortunately, providing power to these remote areas can be expensive and determining the most economical solution is not trivial. This paper presents a method to compare the economics of different small-scale power systems for developing world. In this method, models are developed to describe the performance of power systems composed of diesel generators, batteries with photovoltaics or wind turbines, and hybrid systems. These models are coupled to an optimizer to determine the lowest cost solution that meets the desired system reliability. The reliability is expressed as Loss of Load Probability, and is computed using hourly solar and wind data. In this paper, this method is used to design a power system for a small hospital in the developing world. The results are presented for three sample locations in Honduras, Pakistan, and Uganda. Results show that the economic attractiveness of different technologies varies greatly due to local climatic conditions. The variety and soundness of the solutions found using this method show that it can aid in the design of a small-scale power system for any location in the developing world.


2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
A. Elsherif ◽  
T. Fetouh ◽  
H. Shaaban

In recent years a multitude of events have created a new environment for the electric power infrastructure. The presence of small-scale generation near load spots is becoming common especially with the advent of renewable energy sources such as wind power energy. This type of generation is known as distributed generation (DG). The expansion of the distributed generators- (DGs-) based wind energy raises constraints on the distribution networks operation and power quality issues: voltage sag, voltage swell, voltage interruption, harmonic contents, flickering, frequency deviation, unbalance, and so forth. Consequently, the public distribution network conception and connection studies evolve in order to keep the distribution system operating in optimal conditions. In this paper, a comprehensive power quality investigation of a distribution system with embedded wind turbines has been carried out. This investigation is carried out in a comparison aspect between the conventional synchronous generators, as DGs are widely in use at present, and the different wind turbines technologies, which represent the foresightedness of the DGs. The obtained results are discussed with the IEC 61400-21 standard for testing and assessing power quality characteristics of grid-connected wind energy and the IEEE 1547-2003 standard for interconnecting distributed resources with electric power systems.


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