American Journal of Energy Research

In this paper, the problem of increasing the energy capacity of compressed air used as a mobile carrier of energy is considered. An idea of preliminary Joule-Thomson self-heating of the compressed air with the following heat redistribution to obtain the maximal work at maximal power is considered. A simple circle combination of a heat exchanger and a throttle device-Linde-Hampson anti-machine - is analyzed. Calculations performed in the framework of modified van der Waals gas model show essential increasing of accumulated specific energy of compressed air fuel to the range 0.5-1.0 MJ/kg which is comparable with electrochemical fuel energy. A concept of compressed air fuel production is discussed.

American Journal of Energy Research. 2013, 1(3), 59-67. DOI: 10.12691/ajer-1-3-4
Pub. Date: October 02, 2013

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Application of Fuzzy Control for the Energy Storage System in Improving Wind Power Prediction Accuracy

by A Li-nu-er A Mu-ti, CHAO Qin, TU Er-xun Yi Bu-la-yin and LUO Jian-chun

Original Research

Today the elaboration degree of wind meteorological information far from enough, which leads to the low wind farm wind power prediction accuracy, causing grid scheduling problems , so as to result in instability in power systems easily. This paper selects zinc bromide battery energy storage system for the measurement of improving the forecast accuracy of the wind farms, adopts fuzzy control and sets up fuzzy control rule base for the energy storage system considering the error probability characteristics and the charge state SOC of the energy storage to control the storage charge and discharge power, and does simulation analysis of a wind farm in XinJiang which introduced into the energy storage. At the same time, compared with the traditional control strategy the results indicate that fuzzy control strategy of energy storage system can more effectively improve the wind power short-term forecast accuracy significantly,80% of the predicted value meet the requirements of the state grid has less than ± 25%.

American Journal of Energy Research. 2013, 1(3), 54-58. DOI: 10.12691/ajer-1-3-3
Pub. Date: September 12, 2013

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Studying the Thermal and Cryogenic Performance of Shevadun in Native (Local) Buildings of Dezful Based on Modeling and Environmental Measuring

by Nazanin Nasrollahei, Mohammadjavad Mahdavinejad and Mohammad Hadiyanpour

Original Research

In the native buildings of Dezful, spaces called (Shevadun) that were constructed under the ground, were used, which used the thermal mass property of the earth to be protected from cold and warm weather conditions. In the old buildings of Dezful, these spaces that are constructed under the ground are called ((Shevadun)) in native language. In this research, first,the temperature and humidity in one Shevadun sample of the Dezful native buildings were measured using Data Logger units in 5 days (during August). Then, using the Design builder software which is a reliable software in modeling the energy and CFD calculations, the available sample is simulated in order to study the thermal and cryogenic performance. The results of the research show that the temperature of Shevaduns in summer is less than the average maximum temperature and the average minimum temperature of outdoor, and the thermal condition of the Shevadun space during the measurement is lower than the thermal comfort limit which is specified in the ashrae standard. In other words, the Shevadun space is colder than the summer comfort limit of ashrae. The effect of the cold weather of Shevadun on summer places above it which are connected with a trap door, was studied, and the results show that if the summer habit is connected with shevadun, the average temperature is 4 degrees centigrade lower than when the connection trap door is closed, and when the trap door is open, the relative humidity of the summer place will be 2 to 3 percent’s higher, which shows the high potential of the shevaduns in using the passive cooling of spaces. The other part of the paper studies how the cool air inside the shevadun is transferred to the summer place by the trap doors. The results show that in the day, because the door of the shevadun is closed to prevent from entering the warm air of outside to inside the shevadun, the air movement in shevadun and trap door which is the connecting canal between the shevadun and summer place, is very slight, and it is the result of the temperature difference between the vertical layers of the air inside the shevadun , trap door and space, so that , this air movement is not felt, and the cool air of the shevadun has less effect than during the night that the door of shevadun is opened for ventilating its air.

American Journal of Energy Research. 2013, 1(3), 45-53. DOI: 10.12691/ajer-1-3-2
Pub. Date: July 06, 2013

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Energy Audit of Manufacturing and Processing Industries in Nigeria: A Case Study of Food Processing Industry and Distillation & Bottling Company

by Oyedepo Sunday Olayinka and Aremu Thomas Oladele

Original Research

In this paper, analysis of the energy audit of Food processing industry and Distillation and Bottling Company in Ota, Nigeria has been carried out. A walk-through energy audit of these industries was undertaken to identify the major sources of energy in use, identifying the lapses in energy usage, identifying areas to improve energy usage, determining the level of consumption of the energy sources and recommending policy measures that will enhance energy savings in the industries and Nigerian industries at large. The study observed that among a wide variation of end-use electricity consuming equipment, electric motors were the major consumer of electrical energy, accounting for 40-47% of total electric energy. Also from the identified energy use sources in the two industries, it was observed that fuel energy expended in operating the generating set, boilers or heaters in the industries had the highest value of energy use accounting for more than 65% of the total energy used. It was observed that none of the companies under review sufficiently utilized their energy as they all have their energy used ratio far below 1. This was as a result of some factors that contributed to energy waste and energy use inefficiency in the companies. Among these factors are: Poor in housekeeping of air- condition and refrigeration equipments and electric motors that dissipate much heat, use of electric motors that are weak and generate excessive noise because they have been rewound more than twice, improper lagging of boilers that lead to losing much heat, switching on of the lighting points in the day time and generation of electrical energy more than needed in the industry by some electric generator. The study concluded that energy is not sufficiently utilized in these companies and recommendations for efficient energy usage in the industries were proposed in this study.

American Journal of Energy Research. 2013, 1(3), 36-44. DOI: 10.12691/ajer-1-3-1
Pub. Date: June 28, 2013

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