Renewable energy in agro-industrial complex: Power parameters of wind power system for heat production, storage and supply of granary. Part 1

Consider the main parameters of wind power system for heat supply of granaries that could replace a typical grain drier working on organic fossil fuel and having specific grain drying productivity of 32 tones per hour.

 

The parameters of the wind and gaseous power systems for heat supply of granary

 

Electrical power: Grain drier productivity is 32 tones per hour. Electrical energy consumption to dry 1 tone of grain is 3,8 kWh. Drying chamber ventilator productivity is 80000 m3 of air per hour (first zone). Drying chamber ventilator productivity is 42600 m3 of air per hour (second zone).. Cooling chamber ventilator productivity is 49000 m3 of air per hour. Electrical energy consumption is 3,8 х 32 = 121,6 (kWh) = 438 MJ per hour. Electrical energy consumption is 3,8 х 32 х 24 = 2918 (kWh) = 10,5 GJ per day. Power of electrical equipment is 121,6 kW.

Thermal power: Fossil fuel consumption to dry 1 tone of grain is 12,2 kg of low calorie anthracite. Grain mass dried per day is 32 (t/h.) х 24 h = 768 t. Grain mass dried during a month is 768 t. х 30 = 23040 t. Grain mass dryied during 3 months is 23040 t х 3 = 843230 t. Mass of fossil fuel consuming during 1 hour is 32 х 12,2 = 390 kg. Mass of fossil fuel that is consuming during 24 hours is 390 kg x 24 = 9370 kg. Mass of fossil fuel that is consuming during 1 month is 9370 kg x 30 = 281400 kg. Mass of fossil fuel that is consumed during 3 months is 230 t х 3 = 843 t  Quantity of thermal energy consumed during 24 hours is 9370 kg х 29,3 МJ = 277 GJ. Quantity of thermal energy during a month is 277 GJ х 30 = 8310 GJ. Quantity of thermal energy consumed during 3 months is 277 GJ х 30 х 3 = 24900 GJ = 5929 Gcal;  At fuel cost of US$0,7/kg the total cost of fuel consumed during a heating year is 843000 kg х US$0,7/kg = US$590261. 

Wind power: Average power of wind turbines at duration of wind 10 hours a day is (3,18 MW х 24 h)/10 h = 7,63 МW. Average wind power that falls onto 1 m2 area, perpendicular to wind flow direction and wind velocity of 7 m/s during 1 s is 0,5 х 1,2 (kg/m3) х 73 (m/s)3 х 1 m2 = 206 J = 206 J х 0,24 cal/J = 50 cal. Specific WPT power is 206 W. During one hour the 1 m2 of useful wind flow area produces 0,206 kWh = 0,206 kWh х 860 kcal/kWh = 177 kcal. During a day – 10 х 0,206 kWh = 2,06 kWh = 2,06 kWh х 3,6 МJ = 7,4 МJ = 7,4 МJ х 0,24 (МcalJ) = 1,78 Мcal. Area of wind flow cross section А providing power of 7,63 МW is 7,63J/s)/[0,5 х 1,2 (kg/m3) х 73(m/s)3] = 37017 m2. Wind flow with the cross section area of 37017 m2 can be taken, for example, by 3 wind turbines (every one takes of 11660 m2 and has length of turbines blades of 62 m.

Heat accumulator: Heat quantity stored by 1 m3 volume of water with a specific heat capacity of 4,2 kJ/(kg·°C) at heating from 200C to 700C is 4,2 kJ/(kg·°C) х 50·°C = 210 MJхm-3; volume of water providing accumulation of 276,5 GJ per day is 276,5 GJ/0,210 GJхm-3 = 1316 m3.

Tables 4.3 and 4.4 illustrate parameters of wind and traditional systems for heat supply of granaries of different powers.

 

 

By Vasil Sidorov on October 15, 2012

Technopark QUELTA, Queltanews from

Nizhyn Laboratories of Scanning Devices

sidorovvasil@gmail.com

 


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