Abstract: This paper presents a novel three-phase utility
frequency to high frequency soft switching power conversion circuit
with dual mode pulse width modulation and pulse density modulation
for high power induction heating applications as melting of steel and
non ferrous metals, annealing of metals, surface hardening of steel
and cast iron work pieces and hot water producers, steamers and
super heated steamers. This high frequency power conversion circuit
can operate from three-phase systems to produce high current for
high power induction heating applications under the principles of
ZVS and it can regulate its ac output power from the rated value to a
low power level. A dual mode modulation control scheme based on
high frequency PWM in synchronization with the utility frequency
positive and negative half cycles for the proposed high frequency
conversion circuit and utility frequency pulse density modulation is
produced to extend its soft switching operating range for wide ac
output power regulation. A dual packs heat exchanger assembly is
designed to be used in consumer and industrial fluid pipeline systems
and it is proved to be suitable for the hot water, steam and super
heated steam producers. Experiment and simulation results are given
in this paper to verify the operation principles of the proposed ac
conversion circuit and to evaluate its power regulation and
conversion efficiency. Also, the paper presents a mutual coupling
model of the induction heating load instead of equivalent transformer
circuit model.
Abstract: Tea is a widely consumed beverage that contains many components. Caffeine belongs to this group of components called alkaloids contain nitrogen. In this study caffeine contents of three types of Turkish teas are determined by using extraction method. After condensation process, residue of caffeine and oil are obtained with evaporation. The oil which is in the residue is removed by hot water. Extraction process performed by using chloroform and the crude caffeine is obtained. From the results of experiments, caffeine contents are found in black tea, green tea and earl grey tea as 3.57±0.43%, 3.11±0.02%, 4.29±0.27%, respectively. Caffeine contents which are found in 1, 5 and 10 cups of tea are calculated. Furthermore, the daily intake of caffeine from black teas that affects human health is investigated.
Abstract: Tea has several types of essential elements. Potassium,
magnesium and phosphorus are some examples of these elements.
Tea is widely used drink in Turkey, also some people puts a lemon
wedge to tea for different taste. In this study potassium, magnesium
and phosphorus contents after the hot water brewing of black and
green tea were determined by Optical Emission Spectroscopy (ICPOES).
Furthermore, how the lemon addition to teas affects the
concentrations of the potassium, magnesium and phosphorus
amount are investigated.
From the results, potassium, magnesium and phosphorus
concentrations are found as 3003.3, 597.1, 1167.2 ppm in black tea
and 3718.0, 3830.5, 376.4 ppm in green tea, respectively. After
lemon addition potassium, magnesium and phosphorus
concentrations are changed to 14930, 830.4, 1113.5 ppm in black tea
and 15460.0, 909.5, 1152.5 ppm in green tea, respectively.
It is seen that lemon addition affects some essential elements in
black and green Turkish teas.
Abstract: Temperature is one of the most principle factors affects aquaculture system. It can cause stress and mortality or superior environment for growth and reproduction. This paper presents the control of pond water temperature using artificial intelligence technique. The water temperature is very important parameter for shrimp growth. The required temperature for optimal growth is 34oC, if temperature increase up to 38oC it cause death of the shrimp, so it is important to control water temperature. Solar thermal water heating system is designed to supply an aquaculture pond with the required hot water in Mersa Matruh in Egypt. Neural networks are massively parallel processors that have the ability to learn patterns through a training experience. Because of this feature, they are often well suited for modeling complex and non-linear processes such as those commonly found in the heating system. Artificial neural network is proposed to control water temperature due to Artificial intelligence (AI) techniques are becoming useful as alternate approaches to conventional techniques. They have been used to solve complicated practical problems. Moreover this paper introduces a complete mathematical modeling and MATLAB SIMULINK model for the aquaculture system. The simulation results indicate that, the control unit success in keeping water temperature constant at the desired temperature by controlling the hot water flow rate.
Abstract: The increasing demand for sufficient and clean
energy forces industrial and service companies to align their strategies towards efficient consumption. This trend refers also to the
residential building sector. There, large amounts of energy consumption are caused by house and facility heating. Many of the
operated hot water heating systems lack hydraulic balanced working
conditions for heat distribution and –transmission and lead to
inefficient heating. Through hydraulic balancing of heating systems,
significant energy savings for primary and secondary energy can be
achieved. This paper addresses the use of KNX-technology (Smart
Buildings) in residential buildings to ensure a dynamic adaption of
hydraulic system's performance, in order to increase the heating
system's efficiency. In this paper, the procedure of heating system
segmentation into hydraulically independent units (meshes) is
presented. Within these meshes, the heating valve are addressed and
controlled by a central facility server. Feasibility criteria towards
such drivers will be named. The dynamic hydraulic balance is
achieved by positioning these valves according to heating loads, that
are generated from the temperature settings in the corresponding
rooms. The energetic advantages of single room heating control
procedures, based on the application FacilityManager, is presented.
Abstract: Tea is consumed by a big part of the world-s
population. It has an enormous importance for the Turkish culture.
Nearly it is brewed every morning and evening at the all houses. Also it is consumed with lemon wedge. Habitual drinking of tea
infusions may significantly contribute to daily dietary requirements of elements.
Different instrumental techniques are used for determination of
these elements. But atomic and mass spectroscopic methods are preferred most. In these study chromium, iron and selenium contents
after the hot water brewing of black and green tea were determined
by Optical Emission Spectroscopy (ICP-OES). Furthermore, effect
of lemon addition on chromium, iron and selenium concentration tea
infusions is investigated.
Results of the investigation showed that concentration of
chromium, iron and selenium increased in black tea with lemon addition. On the other hand only selenium is increased with lemon
addition in green tea. And iron concentration is not detected in green
tea but its concentration is determined as 1.420 ppm after lemon addition.
Abstract: In this paper, in order to investigate the effects of
photovoltaic system introduction to detached houses in Japan, two
kinds of works were done. Firstly, the hourly generation amount of a
4.2kW photovoltaic system were simulated in 46 cities to investigate
the potential of the system in different regions in Japan using a
simulation model of photovoltaic system. Secondly, based on the
simulated electricity generation amount, the energy saving, the
environmental and the economic effect of the photovoltaic system
were examined from hourly to annual timescales, based upon
calculations of typical electricity, heating, cooling and hot water
supply load profiles for Japanese dwellings. The above analysis was
carried out using a standard year-s hourly weather data for the
different city provided by the Expanded AMeDAS Weather Data
issued by AIJ (Architectural Institute of Japan).
Abstract: In this paper a polymer electrolyte membrane (PEM)
fuel cell power system including burner, steam reformer, heat
exchanger and water heater has been considered to meet the
electrical, heating, cooling and domestic hot water loads of
residential building which in Tehran. The system uses natural gas as
fuel and works in CHP mode. Design and operating conditions of a
PEM fuel cell system is considered in this study. The energy
requirements of residential building and the number of fuel cell
stacks to meet them have been estimated. The method involved
exergy analysis and entropy generation thorough the months of the
year. Results show that all the energy needs of the building can be
met with 12 fuel cell stacks at a nominal capacity of 8.5 kW. Exergy
analysis of the CHP system shows that the increase in the ambient air
temperature from 1oC to 40oC, will have an increase of entropy
generation by 5.73%.Maximum entropy generates for 15 hour in 15th
of June and 15th of July is estimated to amount at 12624 (kW/K).
Entropy generation of this system through a year is estimated to
amount to 1004.54 GJ/k.year.
Abstract: The system is made with main distributed components:
First Level: Industrial Computers placed in Control Room (monitors thermal and electrical processes based on the data provided by the second level); Second Level: PLCs which collects data from process and transmits information on the first level; also takes commands from this level which are further, passed to execution elements from third
level; Third Level: field elements consisting in 3 categories: data collecting elements; data transfer elements from the third level to the second; execution elements which take commands from the second
level PLCs and executes them after which transmits the confirmation of execution to them. The purpose of the automatic functioning is the optimization of the co-generative electrical energy commissioning in the national
energy system and the commissioning of thermal energy to the consumers.
The integrated system treats the functioning of all the equipments and devices as a whole: Gas Turbine Units (GTU); MT 20kV Medium Voltage Station (MVS); 0,4 kV Low Voltage Station (LVS); Main Hot Water Boilers (MHW); Auxiliary Hot Water Boilers (AHW); Gas Compressor Unit (GCU); Thermal Agent Circulation
Pumping Unit (TPU); Water Treating Station (WTS).
Abstract: This paper describes a one-dimensional numerical model for natural gas production from the dissociation of methane hydrate in hydrate-capped gas reservoir under depressurization and thermal stimulation. Some of the hydrate reservoirs discovered are overlying a free-gas layer, known as hydrate-capped gas reservoirs. These reservoirs are thought to be easiest and probably the first type of hydrate reservoirs to be produced. The mathematical equations that can be described this type of reservoir include mass balance, heat balance and kinetics of hydrate decomposition. These non-linear partial differential equations are solved using finite-difference fully implicit scheme. In the model, the effect of convection and conduction heat transfer, variation change of formation porosity, the effect of using different equations of state such as PR and ER and steam or hot water injection are considered. In addition distributions of pressure, temperature, saturation of gas, hydrate and water in the reservoir are evaluated. It is shown that the gas production rate is a sensitive function of well pressure.
Abstract: The paper presents the results of the European EIE
project “Realising the potential for small scale renewable energy
sources in the home – Kyotointhehome". The project's global aim is
to inform and educate teachers, students and their families so that
they can realise the need and can assess the potential for energy
efficiency (EE) measures and renewable energy sources (RES) in
their homes. The project resources were translated and trialled by 16
partners in 10 European countries.
A web-based methodology which will enable families to assess
how RES can be incorporated into energy efficient homes was
accomplished. The web application “KYOTOINHOME" will help
the citizens to identify what they can do to help their community
meet the Kyoto target for greenhouse gas reductions and prevent
global warming. This application provides useful information on how
the citizens can use renewable energy sources in their home to
provide space heating and cooling, hot water and electricity. A
methodology for assessing heat loss in a dwelling and application of
heat pump system was elaborated and will be implemented this year.
For schools, we developed a set of practical activities concerned with
preventing climate change through using renewable energy sources.
Complementary resources will also developed in the Romanian
research project “Romania Contribution to the European Targets
Regarding the Development of Renewable Energy Sources" -
PROMES.
Abstract: The intermittent nature of solar energy and the energy
requirements of buildings necessitate the storage of thermal energy.
In this paper a hybrid system of storing solar energy has been
analyzed. Adding a LHS medium to a commercial solar water heater,
the required energy for heating a small room was obtained in
addition to preparing hot water. In other words, the suggested hybrid
storage system consists of two tanks: a water tank as a SHS medium;
and a paraffin tank as a LHS medium. A computing program was
used to find the optimized time schedule of charging the storage
tanks during each day, according to the solar radiation conditions.
The results show that the use of such system can improve the
capability of energy gathering comparing to the individual water
storage tank during the cold months of the year. Of course, because
of the solar radiation angles and shorten daylight in December &
January, the performance will be the same as the simple solar water
heaters (in the northern hemisphere). But the extra energy stored in
November, February, March & April, can be useful for heating a
small room for 3 hours during the cold days.
Abstract: Using logarithmic mean Divisia decomposition technique, this paper analyzes the change in industrial energy intensity of Fujian Province in China, based on data sets of added value and energy consumption for 35 selected industrial sub-sectors from 1999 to 2009. The change in industrial energy intensity is decomposed into intensity effect and structure effect. Results show that the industrial energy intensity of Fujian Province has achieved a reduction of 51% over the past ten years. The structural change, a shift in the mix of industrial sub-sectors, made overwhelming contribution to the reduction. The impact of energy efficiency’s improvement was relatively small. However, the aggregate industrial energy intensity was very sensitive to both the changes in energy intensity and in production share of energy-intensive sub-sectors, such as production and supply of electric power, steam and hot water. Pathway to reduce industrial energy intensity for energy conservation in Fujian Province is proposed in the end.
Abstract: The purpose of this work is fast design optimization of
the seal chamber. The study includes the mass transfer between lower
and upper chamber on seal chamber for hot water application pumps.
The use of Fluent 12.1 commercial code made it possible to capture
complex flow with heat-mass transfer, radiation, Tailor instability,
and buoyancy effect. Realizable k-epsilon model was used for
turbulence modeling. Radiation heat losses were taken into account.
The temperature distribution at seal region is predicted with respect
to heat addition.
Results show the possibilities of the model simplifications by
excluding the water domain in low chamber from calculations. CFD
simulations permit to improve seal chamber design to meet target
water temperature around the seal. This study can be used for the
analysis of different seal chamber configurations.