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5AUTONOMOUS ENERGY TECHOLOGICAL COMPLEX TESTS IN REAL GEO-CLIMATE CONDITIONS
A. Basteev, V. Solovey, V. Forfutdinov
Zhukovsky National Aerospace University "Kharkov Aviation Institute", 17, Chkalov Str., Kharkov, 61070, Ukraine E-mail: a.v.basteev@htsc.kipt.kharkov.ua
The energy-technological complex (ETC) destination is the transforming of primary renewable sun/ wind forms of energy into electric one as well the sub-products fabrication. The ETC consists of the following constituent elements: wind power station, photo-voltaic transformer, distiller, fuel cell, electrolyzer for hydrogen and oxygen generation and compressed gases storing and supply system (SSS). Control system is also included in the ETC configuration. The hydrogen and oxygen are generated in the new type of electrolyzer and stored in the SSS for further use in fuel cell. The desalination of seawater and sea salt yielding is the ETC output as well. The exploitation peculiarities of ETC constituent element are considered as well. The creation and operational demonstration of the autonomous ETC are encouraged by STCU (www.stcu.int), project #UZB-23j.
Preface
The purposes of accomplished work were the investigation, design, manufacturing and operational demonstration of ETC and its constituent elements for transformation of the renewable forms of "dirty" energy (solar and/or wind) into conventional (quality) electrical energy with obtaining of following sub-products:
♦ Ecologically pure secondary energy carrier of future (hydrogen);
♦ Distilled water;
♦ Compressed gases (hydrogen and oxygen);
♦ The educed from seawater salt (for cosmetic industry).
In connection with depleting of traditional non-renewed sources of energy (fossils: coal, petroleum, natural gas etc.) the researches on seeking the renewed sources of energy are actively carried out all over the world. For the first time the described below ETC configuration has been considered in [1] although the similar schemes were well known and considered earlier. Nevertheless the attempts of renewable energy transformers compiling (namely the wind turbine and photovoltaic panel) with electrolyzer, fuel cell and the distiller in to whole complex did not undertake till now. This work is focused on to following targets: elaboration, design and optimization of the ETC configuration; manufacturing and assembling of constituent elements; creation of the specialized control system and its providing by responsible SOFTWARE for adaptation and optimal ETC operation in the geo-climate conditions of places of possible application. Thus the novelty of ETC consists in the combination and advisable functional interaction of the constituent elements. Scientific
and technological approaches of ETC were published in [2, 3]. The ETC has been mounted at the tested both in laboratory as well at real geo-cli-mate conditions. The tests were conducted in Crimea, Ukraine in February - March 2004. The obtained results completely coincided with laboratory ones and verified the ETC capacity for work.
ETC constituent elements description and operational peculiarities
The ETC consists of the following constituent elements that are characterized by the harmonized parameters: primary energy receivers — wind power station (WPS), photovoltaic transformer; distiller with solar collector; hydrogen and oxygen generator (electrolyzer); vessels for compressed gases SSS; fuel cell. The ETC is provided by informational control system connected with separate elements by means of pipelines and sensors for gathering and processing of working parameters data. Basic idea of the renewable energy consumption exists in ETC opportunity of "dirty" energy processing. Obtained from WPS or solar energy transformer (SET) irregular primary energy flow is shared to the electrolyzer that is non-sensitive to the quality of received energy. It is evidently that this approach is preferable for creation of autonomous power plants with small and moderate power output for individuals. The ETC as the whole unit has been tested on the shore of Black Sea, Ukraine and these conditions are similar with Mexico ones. The elaborated ETC could be considered as the autonomous hydrogen refill station for different kinds of hydrogen-feed vehicles.
Wind power station. Designed WPS is able to transform the kinetic energy of the moving air as
Статья поступила в редакцию 16.09.2005. The article has entered in publishing office 16.09.2005.
International Scientific Journal for Alternative Energy and Ecology ISJAEE № 8(28) (2005) Международный научный журнал «Альтернативная энергетика и экология» АЭЭ № 8(28) (2005)
Fig. 3. Solar panel with total power 0.5 kW
The operating pressure about 15 MPa provides the hydrogen and oxygen generation directly in compressed state. The electrolysis cycle operational mode is based on the shared in time hydrogen and oxygen emanation. This is achieved due to use of electro-active electrodes that can store hydrogen or oxygen in accordance with their capacity and further hydrogen and oxygen emanation in the next part of the cycle. The switching from one of the component receiving to it emanation can be realized by electrodes pole switching. The cycle duration is determined by the electrochemical capacity and output of the active-electrodes.
The tests were conducted at the levels of 25, 50, 75 and 100 percent of maximum power consumption. The maximum power of high-pressure electrolyzer was ~450 W (voltage was up to 0.200 kV, and current consequently up to 2.2 A). The electrolyzer is equipped by the electric energy transformer with the aim of harmonizing with WPS generator. The demonstrated output of hydrogen was 0.52 m3 and oxygen 0.26 m3, the specific energy consumption per hydrogen was ~4.9 kW/m3 with efficiency ~0.9. The content of oxygen additives in hydrogen was at the level of 0.04-0.06 % vol. and hydrogen additives in oxygen was 0.080.1 % vol. correspondingly. The duration of elec-trolyzer system adaptation to the energy income differences (electrolyzer dynamical property) was about 60-180 s. Electrolyzer has the unique properties and after the improving the it could demonstrate the ability to reversible operational mode. The simplest vessel type of SSS for compressed gases has been used.
Fuel cell. In order to generate the conventional (standard) electricity from the stored secondary energy carrier — hydrogen, the factory made fuel cell with power 0.4 kW has been used. Hydrogen/air fuel cell produced by Canadian firm ASTRIS ENERGI INC is shown on Fig. 5.
Distiller. Distiller with power <3 kW for sea-water desalination and water with high salt containing from underground sources purification is one of the energy consumer and ETC constituent element. The principle of "instantaneous boiling" was applied. The distiller module was realized both as the ETC constituent element as well as detached facility with possible energy supply from regular energy sources. The distiller principle scheme was performed in details in [3]. During the process of thermal distillation the complete water demineral-
Fig. 2. Wind power station replaced on the roof of hotel
well as the energy of short-duration wind gusts with maximum efficiency. The WPS's turbine blades are providing by special mechanical system for the airflow redistribution. This especially elaborated and patented engineering development allows taking off the limitations for upper wind velocity value. The WPS is the production of firm "WIND WORLD", Ukraine; Chief designer is A. Lushnya. The designed WPS as the ETC constituent element can be applied in the regions with moderate year wind velocity i3 m/s. The experimentally defined dependence of output power upon wind velocity can be seen at the diagram (see Fig. 1). Fig. 2 performs the general view of WPS on the roof of the building.
Photovoltaic transformer. The operable in calm conditions solar energy receiver was included into ETC scheme. Produced by firm "SOLAR KW" photovoltaic transformer with maximum power 0.5 kW is shown on Fig. 3.
Electrolyser. The consumed non-steady "dirty" energy is delivered to the electrolyzer to decay the water on to hydrogen and oxygen. The electrolyzer with active elements and original scheme and consumed power ~ 0.5 kW was used in the project.
P, W
3500
3000
2500
2000
1500
1000
13 14
V, m/s
Fig. 1. The dependence of WPS output upon wind velocity. The electric generator provides the output parameters: voltage up to 70 V, and current up to 31 A
International Scientific Journal for Alternative Energy and Ecology ISJAEE № 8(28) (2005) Международный научный журнал «Альтернативная энергетика и экология» АЭЭ № 8(28) (2005)
Экологические аспекты использования альтернативной энергетики, экология мегаполисов, малых городов, деревень
H2, O2, m3 Ж
H2O, g A
1.0 840
0.8 680
0.6 520
0.4 360
0.2 200
0.045 40
0.022
0.54 1 2 3
Fig. 4. Electrolyzer and outcome characteristics: 1 — O2; 2 — H2O; 3 — H2
N, kW h
LABCELL 200 low power voltage-current characteristic
14
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S? 9.
3
- -
1,5
4,5
7
Direct current, A
Fig. 5. Hydrogen/air fuel cell with power 0.1-0.4 kW
ization and sterilization take place thus the obtained water could be used as drinkable. The water circulation in the facility is doing under compulsion. In order to heat the water injected into chamber the electric heater, regeneration system and solar energy transformer (SET) are used. Some of obtained distilled water is delivered to electro-lyzer. The educed sea salts should be used in pharmacological industry for example.
On the basis of thermodynamic calculations at shaping appearance of water distiller the following design parameters were selected and confirmed experimentally:
♦ potency of an electric heater Ne = 2.7 kW;
♦ potency of the electric drive of the pump (quality electric power obtained from a fuel cell or the solar battery) Np = 0.2 kW;
♦ parameters of water on an inlet in the expansive device P = 1.0 MPa, Tw = 176 °C; the mass flow of seawater on an inlet Gw = 1410-3 kg/s;
♦ the mass flow of drinkable water Gw = = 2.010-3 kg/s, from which 0.1410-3 kg/s is transmitted to an fuel cell.
Specific energy on deriving of clear drinkable water Nsp = 0.379 kWh/liter (theoretical estimation for two stages purification process).
Water distiller is intended for deriving distillate from seawater. The scooping of seawater is carried out or from an open pool, or from a special settling tank (Fig. 6).
Fig. 6. The water distiller assembled with solar collector for sea water preheating
Main obtained results and recorded parameters
The operation of such complexes demands of their adaptation to the geo-climate conditions of region of use and this adaptation are provided by the specialized control system. The control system provides the distribution of energy supply from WPS and SET to the secondary capacitors and energy transformers. The regulation and control system for ETC realizes the rational electrical en-
International Scientific Journal for Alternative Energy and Ecology ISJAEE № 8(28) (2005) Международный научный журнал «Альтернативная энергетика и экология» АЭЭ № 8(28) (2005)
ergy distribution from the primary energy converters to the external consumers and for energy storing and buffering. The recommendations for ETC efficiency increasing are registered as control system's SOFTWARE and corresponded to the „ concrete geo-climate conditions. As the result of ^ project implementation assembled ETC as whole * unit has been tested and technical documentation | (with use of SOFT SOLIDWORK) and parameters ■75 for control system tuning was presented for possi-
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Je ble customers.
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The control system destination is providing of 1 main working processes of energy output in auto-£ matic regime and in regime of manual control. g There are following control system functions: © - "stand by" control of ETC main constituent elements;
- forming of rational ETC configuration in dependence upon actual state of energy sources and ETC aggregates and analysis of possibility of any working process implementation;
- switching in/off of ETC elements;
- keeping of ETC elements working parameters at different regimes in accordance with requirements of energy consumption/transformation technology;
- recording of working parameters data on floppy discs;
- switching off of ETC aggregates in cases of energy consumption reducing down to minimal values.
Automatic operational mode of control system consists in series of controlled procedures of ETC elements tuning in accordance with selected variants F working processes realization. If the energy consumption level changes the control system provides the internal energy flows redistribution taking into account the defined majorities.
The results of development and natural testing (April 2004 in the Crimea, Ukraine) of the Energy-Technological Complex allow generalizing over the input/output characteristics:
♦ Wind-energy station — providing 2-2.8 kW (70 V, ~ 31 A).
< ♦ Stationary silicon solar battery — 0.5 kW $ (100 V, 5 A), efficiency of energy transformation £ is 15 % .
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♦ Water distiller with 0.2 kW electric driver/ | engine — 1.5-2 kW total power (211V, 9.5 A), 1 distilled water output 1 liter/kWh, efficiency $ 0.9 kW h/l (one stage process) and 0.6-0.7 kW/l
0
I, for two stages process.
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♦ High-pressure electrolyzer — 0.45-0.5 kW (200 V, 2.2 A) of consumed power and with specific energy consumption ~4.9kW/m3 of hydrogen showed the efficiency about 0.9.
♦ Storage/supply system for hydrogen (with 0.04-0.06 vol. % of oxygen as additives) and oxygen (with 0.08-0.1 vol. % of hydrogen as additives) in cylinders right at high pressure (15.0 MPa).
♦ Fuel cell — consumes H2 — 270 l/h, air-1500 l/h at 0-80 °C, produces electricity 150400 W (15-20 V, 10-20 A), efficiency ~0.5.
♦ The automatic control system was done and the control parameters were controlled.
♦ The technical documentation (technical project) for complete configuration of ETC with use of licensed SOFTWARE SOLIDWORK.
The total demonstrated ETC efficiency is about 25-26 %. The duration of ETC recoupment could be estimated as ~5-6 years correspondingly with high ecological indexes. The propositions for further commercialization of the obtained due to project implementation results and characteristics for the ETC should be oriented on the markets of USA, Mexico, Israel and Asia or Near East Countries. On the base of light climate and wind-activity maps inherent to the number of climate zones (Kharkov region, Crimea, Asian countries) the typical diagrams of energy exchange can be created. In accordance with this diagram the permissible operational modes for constituent elements will be defined and work orders for their improving will be determined.
References
1.Basteev A., Solovey V., Prognimack A., Chashka Kh., Beletsky V. The device for transformation of the sun, wind or high-tide energy to the hydrogen // Proc. of Int. Symp. HYPOTHESIS-1. Cassino, Italy, 1995, June 22-24. P. 125-131. Chapter 2.
2. Muminov M., Zakhidov R., Basteev A., Bazima L., Rashkovan V., Solovey V., Progni-mack A. Autonomous energy technological complex with hydrogen as the secondary energy carrier // Proc. of Int. Symp. HYPOTHESIS-1V. Stralsund, Germany, 2001, September 09-14. Vol. 1. P.108-112.
3. Muminov M., Basteev A., Solovey V. Autonomous energy technological complex with hydrogen as the secondary energy carrier (2) // ISJAEE. 2004. Vol. 1. P. 64-68.
International Scientific Journal for Alternative Energy and Ecology ISJAEE № 8(28) (2005) pp
Международный научный журнал «Альтернативная энергетика и экология» АЭЭ №8(28) (2005) J J
