Search Results

1 - 10 of 551 items :

  • "performance" x
Clear All
Performance Evaluation of Photovoltaic Solar Air Conditioning

Abstract

Information on the electrical-driven solar air conditioning (SAC) is rather scanty. A considerable body of technical data mostly concerns large-scale photo-voltaic solar air conditioning (PV-SAC) systems. Reliable information about the energy output has arisen only in recent years; however, it is still not easily accessible, and sometimes its sources are closed. Despite these facts, solar energy researchers, observers and designers devote special attention to this type of SAC systems. In this study, performance evaluation is performed for the PV-SAC technology, in which low-power (up to 15 kWp of cooling power on average) systems are used. Such a system contains a PV electric-driven compression chiller with cold and heat sensible thermal storage capacities, and a rejected energy unit used for preheating domestic hot water (DHW). In a non-cooling season, it is possible to partly employ the system in the reverse mode for DHW production. In this mode, the ambient air serves as a heat source. Besides, free cooling is integrated in the PV-SAC concept.

Open access
Improvement and Optimisation of Gyroplane Performance

oraz parametrów sterowania na czas trwania i wysokość bezrozbiegowego startu wiatrakowca (”Analysis of the impact of design factors and control parameters on duration and height of autogiro’s jump start”),. Prace Instytutu Lotnictwa, Nr 219. s. 39-46. (in Polish) [5] Drela M., Youngren H., Scherrer M., and Deperrois A., 2012, “XFLR-5”, available at: http://www.xflr5.com/xflr5.htm [6] Floros M.W., Johnson W., Performance Analysis of the Slowed-Rotor Compound Helicopter Configuration, Journal of the American Helicopter Society. Presented at the AHS 4th

Open access
Performance Evaluation of Irbene RT-16 Radio Telescope Receiving System

50 GHz. The Astrophysical Journal Supplement Series, DOI: 10.1088/0067-0049/204/2/19 6. MT Mechatronics. (2015). Report VTP2-DOC-11210-02: Assessment of the RT16 antenna surface performance and illumination efficiency.

Open access
Thermal Performance Analysis of Solar Collectors Installed for Combisystem in the Apartment Building

-2697. European Solar Thermal Technology Platform. 2007. Solar Heating and Cooling for a Sustainable Energy Future in Europe. Brussels : Renewable Energy House. Kalogirou, S. A. (2004). Solar thermal collectors and applications. Progress in Energy and Combustion Science, 30 (3), 231-295. Hossain, M. S., Saidur, R., Fayaz, H., Rahim, N. A., Islam, M. R., Ahamed, J. U., & Rahman, M. M. (2011). Review on solar water heater collector and thermal energy performance of circulating pipe. Renewable and Sustainable Energy Reviews

Open access
Accurate Model for Temperature Dependence of Solar Cell Performance According to Phonon Energy Correction

REFERENCES 1. Hitha, P., Sosale, S.S., Sushmitha, S., & Rekha, K.R. (2017). Performance analysis of various-4-wheelers with IC engines for hybridization. International Journal of Advance Research, Ideas, and Innovations in Technology 3 (3), 1322–1327. 2. Chu, S., Cui, Y., & Liu, N. (2017). The path towards sustainable energy. Nature Materials 16 , 16–22. 3. Ferreira, A., Kunh, S.S., Fagnani, K.C., De Souza, T.A., Tonezer, C., Santos, G.R.D., & Coimbra-Araujo, C.H. (2018). Economic overview of the use and production of photovoltaic solar energy

Open access
Experimental Measurement of Erbium-Doped Optical Fibre Charecteristics for Edfa Performance Optimization

. Essiambre, R.J., Kramer, G., Winzer, P.J., Foschini, G.J., & Goebel, B. (2010). Capacity Limits of Optical Fibre Networks. J. Lightwave Technol., 28 , 662–701. 5. Lavrinovica, I., Porins, J., & Ivanovs, G. (2015). Estimation of EDFA performance in 40 Gbit/s 8 channel DWDM transmission system. In Progress in Electromagnetics Research Symposium (PIERS) Proceedings , 6–9 July 2015 (pp. 502–505). Prague, Czech Republic. 6. Lavrinovica, I., & Porins, J. (2015). Noise figure analysis of EDFA with different pumping configurations in 40 Gbit/s 8 channel DWDM

Open access
Fabrication and performance of fl y ash granule filter for trapping gaseous cesium

Abstract

Although a disk-type fly ash filter has shown a good performance in trapping gaseous cesium, it has difficulty in charging filters into a filter container and discharging waste filters containing radioactive cesium from a container by remote action. To solve the difficulty of the disk-type fly ash filter, five types of granule filters, including a ball type, tube type, and sponge-structure type have been made. Among them, the best filter type was chosen through simple crucible tests. The five types of granule filters packed into containers were loaded into five alumina crucibles of 50 cc. Five grams of CsNO3 was used as a gaseous cesium source. They were then placed in a muffle furnace and heated to 900°C and maintained for 2 hours. After the experiment, the weights of the cesium trapped filters were measured. Among the five types of granule filters, the sponge-structure type granule filter was the best, which has the highest trapping capacity of cesium. Its capacity is 0.42 g-Cs/g-filter. The chosen sponge-structure type granule filters and disk-type filters have been tested using a two-zone tube furnace. Cs volatilization and Cs trapping zones were maintained at 900 and 1000°C, respectively. Sixteen grams of CsNO3 was used as a gaseous cesium source. The cesium trapping profile of the sponge-structure type granule filters was almost similar to that of the disk-type fly ash filters. For both cases, cesium was successfully trapped within the third filter.

Open access
Investigation of EDFA Performance in DWDM Transmission Systems Under Different Operating Conditions

Abstract

The article investigates dependence of EDFA performance on its operating conditions. First of all, the impact of changes in channel spacing on the quality of the amplifier signal and on the desired EDFA configuration is observed – three different values of channel spacing are considered – 37.5 GHz, 50 GHz and 100 GHz. Afterwards, the impact of EDFA positioning on the quality of the amplified signal and the desired configuration is assessed. Three different EDFA positioning scenarios are considered – when the EDFA is used as a power booster, as an in-line amplifier and as a preamplifier. In all cases, such configuration of the EDFA is found that can ensure bit-error ratio (BER) values below 1·10−9 in all channels of the system. To assess the performance of the amplifiers, power penalty values are obtained in respect to identical transmission systems but without amplification.

Open access
Performance of a Voltage Step-Up/Step-Down Transformerless DC/DC Converter: Analytical Model

Performance of a Voltage Step-Up/Step-Down Transformerless DC/DC Converter: Analytical Model

The authors present an analytical model for a voltage step-up/step-down DC/DC converter without transformers. The proposed topology is a combination of classic buck and boost converters in one single circuit but with differing operational principles. The converter is developed for a wind power autonomous supply system equipped with a hydrogen electrolytic tank and a fuel cell for energy stabilization. The main power source of the hydrogen-based autonomous supply system is energized by a synchronous generator operating on permanent magnets and equipped with a diode bridge. The input voltage of the converter in this case varies in the range 0-700 V, while its output DC voltage must be 540 V according to the demand of other parts of the system. To maintain the rated voltage, a special electrical load regulation is introduced. The calculations of the converter, the generator (equipped with a diode bridge) as element of the power system supply joint, and the load replaced by resistance are verified with PSIM software.

Open access
Noise Immunity of the Fibonacci Counter with the Fractal Decoder Device for Telecommunication Systems

Abstract

The paper presents the improved method of noise immune Fibonacci counting in the minimal form of representation. The method was tested and investigated in the developed noise immune pulse counter based on a minimal form of Fibonacci code with a fractal decoding device. The proposed device, which is simulated in the NI Multisim software, possesses a homogenous structure, increased noise immunity, performance and detection of bit errors in the process of its operation.

Open access