The chipper used was an Edsbyhuggen 250H (Edsbyhuggen AB, Sweden, year of manufacture 2011) with a 30kW electric motor (Busck T1C 200L-4), which had an efficiency of 91.2–93.5% at full load (Swedish Energy Agency 2010) (Fig. 1). It had a hy- draulic system (15 l) that drove a vertical pair of feed- rollers with an in-feed opening of 250×250 mm. The speed of the feed rollers was constant over the whole experiment. The chipper was equipped with a steel disc 825 mm in diameter and 38 mm thick, with 4 knives, giving a total mass of 205 kg. The disc formed an angle of 45° with the feed direction and rotated at 540 rpm. The 4 knives were adjustable to produce chips from 5 to 12 mm in target length. The chips produced were blown for 2.0 m into an expulsion tube by means of a fan and then collected in 1.5 m 3
feasibility of a biomass-based hybrid gasification power plant in meeting the power needs of an off-grid remote village in Northern Sierra Leone, where it was installed and has been operating since 2012. The configuration of the existing power plant is based on biomass gasifier, diesel generator, battery bank and converter. HOMER Software was used to shape an optimal system that eliminated the use of the diesel generator. The system simulations showed that with a daily load of 355 kWh/day and an annual peak load of 30kW the optimal system is a combination of 20 kW biomass gasifier, 24 batteries, and 10 kW converter. This configuration has a capital cost of $64,250, operating cost of $12,716/year and net present cost of $187,747, which results in a cost of energy of $0.149/kWh compared to the existing configuration whose capital, operating, net present costs and cost of energy are $67,250, $13,664/year, $199.954 and $0.159/kWh, respectively. Operating the existing option can pose a serious challenge as diesel fuel costs may increase in the long term and there is no backup source if supply is disrupted. The optimal simulated system is not only sustainable and techno-economically feasible but has less greenhouse gas emission which complies with the Sierra Leone policy strategy of climate Resilient Green Economy.
individual district to solar PV vendors may require assistance from one or more experts knowledgeable about PV procurement and contracting as well as rate and economic analysis. Important judgments will need to be made both in crafting the RFP and in evaluating the resulting proposals. Analysis and evaluation should also be done pre- RFP ( i.e., regarding the district’s current and projected electricity usage patterns, the potential for switching to alternate electric rate structures, the potential to feed solar electricity into the utility grid and any associated limitations, and estimates of optimally sized solar PV systems), and post-RFP (i.e., evaluating on a comparable basis the various proposals in terms of each firm’s strength, experience, proposed system designs, O&M agreements, and performance guarantees). A good consultant and a good attorney, each with the requisite experience, knowledge, and skills, generally pay for themselves on projects as large as 1,000 kW (1 MW) or more.
and Test Reactor. The versatile MCNP code was used to analyse the neutronics parameters given in the SAR of HEU core, thereby characterizing the core. Subsequently, the LEU core was indentified with necessary changes to the HEU MCNP model. It was ascertained that the reactivity for the LEU core with the same number of fuel pins as the HEU was inadequate, hence the fuel pins were increased from 344 to 348. The neutron flux at the ir- radiation sites was found to be below the nominal value at full power for the LEU and hence the nominal power was increased to 34 kW for a nominal flux value of 1 × 10 12 n/cm 2 ∙s. The parameters investigated for the HEU and LEU are shown in this paper.
ACS800-04 drives are single drive modules that are optimised for building into customers’ own cabinets. They have been designed to minimise the cabinet space used, make cabinet assembly as easy as possible, and give maximum ﬂ exibility. The power range is from 0.55 kW up to 1900 kW. All the drives, regardless of the power and voltage, have the same customer interface and I/O making system design and training easier. The units have everything necessary inbuilt. That includes, for example, inbuilt chokes for harmonic ﬁ ltering as standard, inbuilt braking chopper and inbuilt EMC ﬁ ltering (both are optional in some frame sizes), making cabinet assembly easier. There is also a wide selection of different I/O and communications options. In addition to these there is a selection of external accessories available.
The performed calculations have proved that obtaining 30kW of electric power from the gas turbine and addition- ally 3.5 kW of electric power from the vapour turbine, along with 34kW of thermal power (for R365mfc, Table 1) at 95ºC, or, alternatively, 6.8kW of electric power and over 46kW of thermal power (also for R365mfc, Table 1) at a condenser temperature of 55ºC is possible. This result increases the efficiency of the analyzed gas cycle from 22.3% up to 24.9% and 27.4%, respectively (Table 1). When the condenser temperature is 30ºC, nearly 10kW of electric power can be additionally obtained, which increas- es the efficiency of the combined cycle to about 30% (Table 1). However, in this case we assumed that the heat in the condenser at temperature 30ºC is not used for heating and technological purposes. The performed cycle calculations have also proved that from the thermodynamic point of view, R365mfc works best as a medium in the vapour sys- tem for condenser temperatures equal to 55ºC and 95ºC, while comparable results can also be obtained using R245fa and pentane when this temperature drops down to 30ºC. That is why further part of the analysis, consisting in design calculations of micro turbines, will be performed for these media. Since in a single-stage turbine of this type large enthalpy drops result in the Mach numbers frequently exceeding 2, the analysis was performed for multi-stage tur- bines (four- and five-stage constructions) with subsonic flows. Low mass flow rates determine large rotational speeds exceeding 20,000 rpm, along with partial admission in practically all turbine stages. In construction of this type short blades (of about 10 mm in length) are mounted on small diameters, which results in slightly lower efficiency than that observed in large power steam turbines. At the same time the velocity coefficient, the reaction, and the ratio of disc diameter to blade length (D:L ratio) take values from the ranges typical for classical steam turbines. A collection of basic design parameters of multi-stage micro turbines for select parameters is given in Table 2 [12-14].
PT ISTI Overview: The Initiative overall has been progressing, although at a slower pace than envisaged in the first Implementation Plan. The databank is about to go to version 1 which of course represents the version that the steering committee expects this working group to spin their benchmark analogs of. Latest run (1/30) with a blacklist almost completely constructed and tested, is at 32K stations globally (+/- the odd hundred). More on progress is available in a slew of postings on the initiative blog at http://surfacetemperatures.blogspot.com/ . Once the databank is released we will be trying to encourage groups to go in and create products and submit their algorithms to the benchmarks so the benchmarks do need to be available within some reasonable timeframe. We will have two posters at EGU. We also have a piece appearing in EOS next week led by Jay Lawrimore outlining the databank. A longer, more substantive, exposition the of databank is under preparation led by Jared Rennie.
Abstract—This paper solves the problem of minimizing losses in the stator magnetic core of high-speed electric machines with the use of amorphous iron. A fundamentally new technology for manufacturing of a stator magnetic core from segments of amorphous steel is developed by the authors. The feature of the new stator design is the possibility to use technological ducts located inside the stator as cooling ducts. This aspect signiﬁcantly improves the heat dissipation from the active zone of the stator and, accordingly, minimizing temperature. The eﬃciency of this solution was studied using two power generators of 100 kW and 200 kW and rotational speeds of 60,000 rpm and 45,000 rpm respectively in the software complex Ansys Maxwell. Harmonic compositions of currents and voltages, ﬂux density distributions in active elements of the generator in various operating modes were studied: under load, in a three-phase short-circuit and at idle. Also, the obtained data were compared with analogous models of an electrogenerator made of electrical steel. The results of the study showed the operability and eﬀectiveness of the proposed technology. Based on the results of the research, a prototype of the stator magnetic core made from amorphous iron was created. Losses in the generator were experimentally measured. Also the results of experimental studies of aerodynamic losses are presented.
It is extremely difficult to extend transmission lines to these remote villages resulting in technical limitations and prohibitive cost. People depend on the wood and often kerosene for their lighting needs. There exists little or no reliable access to communication systems, television, and health facilities, all of which requires more electricity. Families in the remote area use precious trees as firewood for cooking, room heating and lighting. These activities, especially indoor cooking and lighting on open fire places, consume firewood, with direct chronic impact on the health of women and children which causes environment pollution . Among various renewable energy sources based technologies, the photovoltaic technology for power generation is considered well-suited technology particularly for distributed power generation in India where non-electrified areas. For many people, powering their homes or small businesses using a small renewable energy system that is not connected to the electricity grid called a stand-alone system makes economic sense and appeals to their environmental values. Now days in remote locations, stand-alone systems about 1 kW with subsidy is not cost-effective than extending a power line to the electricity grid (the cost of which can range from Rs.10 lakhs to Rs.33 lakhs per mile). But these systems are also used by people who live near the grid and wish to obtain independence from the power provider or demonstrate a commitment to non-polluting energy sources. Successful stand-alone systems generally take advantage of a combination of techniques and technologies to generate reliable power, reduce costs, and minimize inconvenience. Some of these strategies include using fossil fuel or renewable hybrid systems and reducing the amount of electricity required to meet your needs .
decreased. Furthermore, when the focal point position was too far above the sheet surface (105 mm and 110 mm) the diameter of the laser spot was increased and energy density on the surface was decreased . Thus, penetration depth and tensile load decreased. According to the obtained experimental results, tensile load, penetration depth, and weld seam width were related to the process parameters. All the parameters and material properties and thicknesses should be considered when selecting the appropriate process parameters to obtain desired weld quality. It was found that penetration depth was related to the heat input so laser power and welding speed were determined properly. For complete penetration, using lower laser power with lower welding speed is required, but it is not acceptable from the view of productivity and the visual quality of the weld bead. Conversely, under increased welding speed and decreased laser power conditions, the heat input was decreased and full penetration did not occur. In terms of weld seam width, laser power was proportional to weld seam width. Weld seam width was increased as laser power increased. Welding speed affected the weld in the opposite way. Furthermore, focal point position influenced the weld width. The best performance was obtained for 2.75 kW laser power, 20 mm/s welding speed and the 100-mm focal point position.
The development of poly-generation smart grids repre- sents an interesting solution to satisfy electricity and heat demand and emission reduction [1,2]: poly-generation smart grids generate electricity, heating and cooling thermal power close to end users, solving the main dis- advantages of the centralized generation approach, due to energy transmission . In fact, the distributed genera- tion approach has several benefits over the others, such as: 1) reduction of transmission and distribution costs: about the 30% of the costs related to electricity supply relates to these costs. Local connections do not generate high capital costs and energy losses for long distances to be wired with overhead facilities; 2) decrease of energy dissipation: piping and conversion devices dissipate al- most 6% of produced energy,  increasing costs and emissions; in a smart grid, these kinds of losses are avoided; 3) increase of energy efficiency: the simultane- ous supply of electrical and thermal demand allow to reduce energy waste, improving system global efficiency; since thermal energy is less easily transported than elec-