Industrial Exhaust Fans As Source Of Power INDUSTRIAL EXHAUST FANS AS SOURCE OF POWER

1ARCHIT PATNAIK, 2S.M.ALI

KIIT University, Bhubaneswar, Odisha, India

Abstract: The energy demand of the world has become unbridled in the past years and is augmenting by leaps and bounds. With increase in energy demand, the conventional sources of energy (fossil fuels, nuclear) are encumbered with monumental pressure and hence, the unremitting use of it, leads to dearth of fossil fuels. This has provoked an extensive research into the area of non-conventional energy sources like hydro, wind, thermal energy, etc. Out of these, the wind energy is being discussed in this paper. Wind energy has a lot of potential and advantages but its utilization is restricted due to its irregularity, geographical conditions and its availability. Our primary goal is to suggest an idea that can surmount these conundrums and utilize the wind energy to its maximum extent. This paper deals with the wind energy that can be derived from the wasted wind energy from industrial exhaust fans. The wind force from an exhaust fan can drive a small and the energy generated from it will be stored in energy storage unit. The dc power stored in the battery will be converted into ac through inverter and then will be supplied to load and hence, can be utilized to meet the growing energy demand.

Keywords: Wind power, Exhaust fan, , Electrical storage

I. INTRODUCTION  Local winds: These winds are caused by unequal heating and cooling of ground and The rapid depletion of natural resources and fossil ocean/lake surfaces during day and night. fuels have led to the development of alternative  Planetary winds (Global winds): These sources of energy. The conventional sources of winds are engendered by daily rotation of energy are non-renewable, cause pollution, not earth around its polar axis and unequal sufficient to meet the growing energy demand. Due to temperature between polar regions and these reasons, it is imperative that we must start equatorial regions. exploring and developing methods to utilize the non- conventional energy sources to reduce too much of III. WIND POWER dependence on conventional sources. One of the most arresting form of non-conventional Wind power is the conversion of wind energy into a energy is wind energy. But due to some of its useful form of energy, such as using: wind turbines to limitations, the wind energy cannot be utilized fully make electrical power, for mechanical to produce electricity. This limitation can be power, wind pumps for water pumping or drainage, surmounted with idea of using the wind from exhaust or sails to propel ships. fan of big industries as a source of power. Advantages of wind energy:  It is renewable source of energy. II. WIND FORMATION  It emits no greenhouse gases and hence non- polluting. Wind is the movement of air across the surface of the  It uses very little land Earth, affected by areas of high pressure and of low  Fuel transportation are not required in wind pressure. The surface of the Earth is heated unevenly energy conversion system. by the Sun, depending on factors such as the angle of Disadvantages of wind energy: incidence of the sun's rays at the surface (which  Owing to its irregularity, the wind energy differs with latitude and time of day) and whether the needs storage. land is open or covered with vegetation. Also, large  Availability of energy is fluctuating in bodies of water, such as the oceans, heat up and cool nature. down slower than the land. The heat energy absorbed  Wind energy conversion is noisy in at the Earth's surface is transferred to the air directly operation. above it and, as warmer air is less dense than cooler  air, it rises above the cool air to form areas of high Low energy density pressure and thus pressure differentials. The rotation  Maintenance is required. of the Earth drags the atmosphere around with it  Wind turbines design, manufacture and causing turbulence. These effects combine to cause a installation have proved to be most complex constantly varying pattern of winds across the surface due to several variables and extreme of the Earth. stresses.  Its implementation is limited due to Sources of wind are discussed below [1]: geographical locations.

Proceedings of 6th IACEECE-2013, 29th September 2013, Chennai, India. ISBN: 978-93-82702-31-3

35 Industrial Exhaust Fans As Source Of Power IV. ELECTRICAL POWER GENERATION process. Then inverter will convert the stored dc FROM WIND ENERGY HISTORY energy into ac. This ac energy can be supplied to the load and grid. In July 1887, a Scottish academic, Professor James This mechanism beget several advantages: Blyth, built a cloth-sailed wind turbine in the garden  Wasted wind force from the exhaust fan can of his holiday cottage in Marykirk and used the be utilized to generated electrical power. electricity it produced to charge accumulators which  It will surmount the present day problems of he used to power the lights in his cottage. His wind energy conversion, that is, it can experiments culminated in a UK patent in 1891. In provide a constant source of wind and the the winter of 1887/8 US inventor Charles F. Brush wind fluctuations can be surmounted. produced electricity using a wind powered generator  It will not be affected by geographical which powered his home and laboratory until about locations and hence can be implemented in 1900. In the 1890s, the Danish scientist and inventor many big industries. Poul la Cour constructed wind turbines to generate  It will be plentiful, renewable and eco- electricity, which was used to produce hydrogen and friendly source of energy. Oxygen by electrolysis and a mixture of the two  The stored energy can be used when main gases was stored for use as a fuel. La Cour was the supply is cut off. Hence, can be used as a first to discover that fast rotating wind turbines with emergency unit. fewer rotor blades were the most efficient in generating electricity and in 1904 he founded the Society of Wind Electricians [2]. By the mid-1920s, 1 to 3-kilowatt wind generators developed by companies such as Parris-Dunn and Jacobs Wind-electric found widespread use in the rural areas of the mid western Great Plains of the US but by the 1940s the demand for more power and the coming of the electrical grid throughout those areas made these small generators obsolete. During the 1920s the first vertical axis wind turbine was built by Frenchman George Darrieus and in 1931 a 100 kW precursor to the modern horizontal wind generator was used in Yalta, in the USSR. In 1956 Johannes Juul, a former student of la Cour, built a 200 kW, three-bladed turbine at Gedser in Denmark, which influenced the design af many later turbines. In 1975 the United States Department of Energy funded a project to develop utility-scale wind turbines. The NASA wind turbines project built thirteen experimental turbines which paved the way for much of the technology used today. Since then, turbines have increased greatly in size with the Enercon E-126 capable of delivering up to 7 MW. Wind turbine production has expanded to many countries and wind power is expected to grow worldwide in the twenty-first century.

V. WORKING PRINCIPLE

The exhaust fan in big industries can play a seminal role in producing electrical energy which can surmount the energy demand to certain extent. The wind force from the exhaust fan can be directed Fig 1.Flow chart of the process of using exhaust fan as a source towards a small windmill in front of it. The wind of power Wind energy thrust from the exhaust fan can drive wind turbine and these wind turbines produce electricity which can Wind energy is the kinetic energy of air in motion, be stored in storage unit. also called wind. Total wind energy flowing through The storage unit may vary according to the an imaginary area A during the time t is[2]: production of electricity from the wind turbines. Preferably ultra capacitors can be used to store monumental amount of energy produced in the ………………………(1)

Proceedings of 6th IACEECE-2013, 29th September 2013, Chennai, India. ISBN: 978-93-82702-31-3

36 Industrial Exhaust Fans As Source Of Power where ρ is the air density; v is the wind speed; Avt is operating in. Once we incorporate various the volume of air passing through A (which is engineering requirements of a wind turbine - strength considered perpendicular to the direction of the and durability in particular – the real world limit is wind); Avtρ is therefore the mass m passing per unit well below the Betz Limit with values of 0.35-0.45 time. Note that ½ ρv2 is the kinetic energy of the common even in the best designed wind turbines. moving air per unit volume. Hence, the power equation becomes Power is energy per unit time, so the wind power Power generated =0.5×A×ρ× Cp× v3 incident on A (e.g. equal to the rotor area of a wind ……………………………………… (4) turbine) is: Typical modern wind turbines have diameters of 40 to 90 metres (130 to 300 ft) and are rated between 500 kW and 2 MW. These values are being tabulated ………………………………………………...... (2) below and the power that can be generated using the Wind power in an open air stream is thus proportional wind from the exhaust fan (taking the exhaust fan to the third power of the wind speed; the available specification of sinter plant 2) is calculated. power increases eightfold when the wind speed Power generated is calculated using eq (4).(taking doubles. Wind turbines for grid electricity therefore Cp=0.4) need to be especially efficient at greater wind speeds. Calculation of power generated from wind turbine from wind speed of industrial exhaust fans:

Table 2: power generated on normal wind turbines using exhaust fan wind

Specifications of common industrial wind turbines are also taken into consideration for the calculation of

Table1: specification of exhaust fans used in generated power using the wind thrust out of exhaust Rourkela Steel Plant fan. Generally and General Electric (GE) dominate The wind speed suitable for viable wind turbine the market for industrial wind turbines in the U.S and generating system is 5m/s or more. At sea level and at specification of some of its models are in below table 15 °C, air has a density of approximately 1.225 3.The following power generated calculation is made kg/m3 (0.0023769 slugs/ft3) according to ISA taking wind speed(15.5 m/s) of sinter plant 2 exhaust (International Standard Atmosphere).But in the fan. calculation, gas density of 0.7 kg/m3 is taken into account. The speed of wind coming out of exhaust fan is very high and when such high wind force strike the wind turbines, it can generate electricity either an equal amount or 1.5-2 times more than the power generated from atmospheric wind and this generation of power varies depending upon the speed of wind from the exhaust fan. This has been proved in the following calculation. VII. DESIGN CONSIDERATIONS FOR VI. CONSIDERATION OF POWER WIND TURBINE COEFFICIENT As it is observed that the wind speed and the power A German physicist Albert Betz concluded that no that can be generated from wind turbines using wind wind turbine can convert more than 16/27 (59.3%) of force from industrial exhaust fan are higher than the the kinetic energy of the wind into mechanical energy rated speed and the capacity of the normal wind turning a rotor. To this day, this is known as the Betz turbines respectively. This makes the design of wind Limit or Betz' Law. The theoretical maximum power turbine a matter of overriding importance. efficiency of any design of wind turbine is 0.59 (i.e. should follow the following no more than 59% of the energy carried by the wind criteria: can be extracted by a wind turbine). This is called the  It should be small in size. “power coefficient” and is defined as: Cpmax= 0.59.  The efficiency should be good. Also, wind turbines cannot operate at this maximum  Insensitive to turbulence. limit. The Cp value is unique to each turbine type and  Should be suitable for mass production at low is a function of wind speed that the turbine is price.

Proceedings of 6th IACEECE-2013, 29th September 2013, Chennai, India. ISBN: 978-93-82702-31-3

37 Industrial Exhaust Fans As Source Of Power VIII. WORLDWIDE WIND GENERATION

Worldwide there are now over two hundred thousand wind turbines operating, with a total nameplate capacity of 238,351 MW as of end 2011.The European Union alone passed some 100,000 MW nameplate capacity in September 2012,while the United States surpassed 50,000 MW in August 2012 and China passed 50,000 MW the same month. World wind generation capacity more than quadrupled between 2000 and 2006, doubling about every three years [2]. At the end of 2011, worldwide nameplate capacity of wind-powered generators was 238 gigawatts (GW), growing by 40.5 GW over the preceding year.2010 data from the World Wind Energy Association, an industry organization states that wind power now has the capacity to generate 430 TWh annually, which is about 2.5% of worldwide electricity usage. Between 2005 and 2010 the average annual growth in new installations was 27.6 percent. Wind power market penetration is expected to reach 3.35 percent by 2013 Fig 3:Global wind power cumulative capacity. and 8 percent by 2018.Several countries have already Wind power in India achieved relatively high levels of penetration, such as 28% of stationary (grid) electricity production in The development of wind power in India started since Denmark (2011), 19% in Portugal (2011), 16% in 1999 and has shown tremendous rise in the past few Spain (2011), 14% in Ireland (2010) and 8% in years. India has the fifth largest installed wind power Germany (2011). As of 2011, 83 countries around the capacity in the world. world were using wind power on a commercial basis. In 2009-10 India's growth rate was highest among the Europe accounted for 48% of the world total wind other top four countries. power generation capacity in 2009. In 2010, Spain became Europe's leading producer of wind energy, As of 31 Jan 2013 the installed capacity of wind achieving 42,976 GWh. Germany held the top spot in power in India was 19564.95 MW, mainly spread Europe in terms of installed capacity, with a total of across Tamil Nadu (7154 MW), Gujarat (3,093 27,215 MW as of 31 December 2010. MW), Maharashtra (2976 MW), Karnataka(2113 MW), Rajasthan (2355 MW), Madhya Pradesh (386 MW), Andhra Pradesh (435 MW), Kerala (35.1 MW), Orissa (2MW), West Bengal (1.1 MW) and other states (3.20 MW). It is estimated that 6,000 MW of additional wind power capacity will be installed in India by 2014. Wind power accounts for 8.5% of India's total installed power capacity, and it generates 1.6% of the country's power [2].

Energy storage The storage of electrical energy generated from the windmills is of overriding concern. Depending upon the wind penetration level, the type of energy storage varies. Low penetration requires daily storage, and high penetration requires both short and long term storage. Super capacitors can store electrical energy. They are much more efficient and advantageous than other kind of batteries/capacitors. They have higher power density, shorter charging times, and higher cycle efficiency (95% or more) and higher specific power than conventional capacitors. Stored energy increases the economic value of wind energy since it can be shifted to displace higher cost Fig 2: worldwide electricity generation from wind. generation during peak demand periods. The potential

Proceedings of 6th IACEECE-2013, 29th September 2013, Chennai, India. ISBN: 978-93-82702-31-3

38 Industrial Exhaust Fans As Source Of Power revenue from this arbitrage can offset the cost and  Wind from the exhaust fan, after travelling losses of storage; the cost of storage may add 25% to some distance, may get dispersed and when the cost of any wind energy stored but it is not the wind spreads over a large area, the wind envisaged that this would apply to a large proportion speed might get decreased and the expected of wind energy generated. power generation(as calculated above) may not take place. Connection to the grid (System integration)  The amount of power generated from such The electricity generated from wind turbines by system may require large electrical storage natural air is sporadic in nature due to variations in system and cost of the storage unit may the wind speed.[4]As wind power is a varying power affect the overall cost of the system. source, which cannot really be dispatched, storage facilities have to deal with these variations. If the CONCLUSION penetration of wind power into the grid is continuously increased, it might reach to a level It is observed that the wind from the exhaust can where economics of the total power production is work as a very good source of electricity. The wind affected in a negative way. This will limit the speed is sometimes more than the natural air speed penetration of wind power into the grid. The optimum and hence can generate even more electrical power penetration depends on specific circumstances and than what is produced from natural air. As it is characteristics of the utility system. In most cases, a discussed earlier that wind from exhaust fan may get wind power penetration will engender no economic dispersed after some time, there should be some kind disadvantage. For higher penetration, total electricity of directors/connectors that will guide the wind from production system has to be re-optimized. This may the exhaust fan directly to wind turbines without require storage unit integration. The distance from getting the average speed of the wind decreased as wind source from the grid poses another limiting the velocity of the wind is most important factor in factor as it influences the economics of wind power. the system. The wasted wind from exhaust fan can be A distance of less than 50 km is generally considered efficaciously utilized to generate power if proper as economically feasible. implementations are done.

The problems that might occur in adopting this REFERENCES idea: The process should be examined from every [1] Er.R.K.Rajput.Non-conventional energy sources and conceivable angle before its execution. This utilization. [2] http://en.wikipedia.org/wiki/Wind_power mechanism will provide plethora of advantages but [3] Md. Abir Hasan+, Mohammad Tanvir Hossain, Ratul Paul, there are few conundrums that the system may face Nilufer Akter, Producing Electrical Energy by using wastage and these conundrums are listed below: wind energy from exhaust fans of industries, International  The wind turbines should be strong enough Journal of Scientific & Engineering Research, Volume 4, Issue 8, August-2013 to withstand high wind force from exhaust [4] B.H.Khan,Non-conventional Energy resources. fan and hence, the design of wind turbines might become complex and costly.

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Proceedings of 6th IACEECE-2013, 29th September 2013, Chennai, India. ISBN: 978-93-82702-31-3

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