Energy Conservation CII Sohrabji Godrej Green Business Centre, Hyderabad A unique Public Private Partnership ( CII, Govt of Andhra Pradesh, USAID and Pirojsha Godrej Foundation ) Opportunities in Boilers & Steam system Centre of Excellence for Energy, Environment, Green Buildings, Renewable energy, Water & Climate change activities in India Agenda v Approach for energy conservation Example from sports v Opportunities for energy efficiency Two Examples from Sports v Sergei Bubka - Ukranianpole vaulter q I person to cross 6-m mark q Continuously improved q Broke his own records > 14 times! improvement Case studies Efficiency Improvement - Continuous Olympic Gold Medal Winners in High Jump 2.6 Inference from Sports 2.4 Fosbury Flip v Fosbury 2.2 2 Scissors Western Roll Straddle q Basically a Gymnast - Not successful q Applied principles of Gymnastics to High Jump 1.8 q Result - A Quantum Jump!!! Adopt the Latest Technology 1.6 Inputs from Other Industries - Innovation 1900 1920 1940 1960 1980 Source: Pascale
Arrest air infiltration through APH Unit I ESP 6.7 % O 2 Few Case Studies 4.6 % O 2 APH 2.3 % O 2 ESP 6.8 % O 2 Q 122.56 M3/s H 406 mm M 725 kw Observation - Air infiltration in Air Preheater v Online flue gas analyzer available Before & after air pre heater v Combustion analysis carried out Using portable combustion analyser Unit 1 APH -A APH -B Inlet Outlet Inlet Outlet % O 2 2.3 4.6 2.8 4.7 Air infiltration in Air Preheater Unit 2 APH -A APH -B Inlet Outlet Inlet Outlet % O 2 4.6 4.9 4.9 5.4 % CO 2 14.1 13.3 13.6 13.4 CO (ppm) 0 0 0 0 Temp o C 323 156 325 155 % CO 2 15.6 13.8 16.4 14.3 CO (ppm) 6 0 0 3 Temp o C 339 151 338 151 Air infiltration in Air Preheater Air infiltration in Air Preheater X Kg of air 20.9 % O 2 v Unit 1 quantity of air ingress is significant 1 Kg flue gas 2.3 % O 2 Air preheater 1+ X Kg of Flue gas 4.6 % O 2 v Unit -1 due for maintenance v Arrest air preheater leakage during the maintenance v Quantity of air infiltration Unit -1 APH - A - 14.1 % APH B - 11.72 % Unit 2 APH A - 1.8 % APH B - 3.2 % v Online monitoring available before & after APH Periodically cross check using portable analyser v Equivalent coal saving - 0.5 tons/hr
Methods for reducing air infiltration in flue gas side Ceramite coating in the bends v Holes in ID fan duct bends & corners Erosion due to flue gas especially in locations where direction of flow changes v Increased air infiltration & hence increased ID fan power consumption Castable refractory for reducing Erosion Methods for reducing air infiltration in flue gas side v Covered with Thermal Fabric Expansion Special material-can withstand temperature upto 700-800 o C Sandwiched with Glass Wool Can be installed ON line 2.Operate the condenser at design v What is the effect of vacuum on turbine performance? v Turbine capacity - 37 MW v Present load - 15 MW loaded less than 50% of the capacity v During normal operating condition very low vacuum has been achieved Achieved vacuum - 0.04 kg/cm 2 (a) Design vacuum - 0.1 kg/cm 2 (a) Operate the condenser at design v Effect of lower vacuum compared to design v Life of the turbine Reduction in dryness fraction of exhaust steam q Turbines normally designed for 0.86 dryness fraction Increased pitting on LP turbine blades v Increase in energy consumption Velocity of steam flow increases Exhaust loss increases
Turbine Exhaust loss curve Operate the condenser at design Pressure (kg/cm 2 ) 0.1 0.09 0.08 0.06 0.05 0.04 Velocity (m/sec) 85 93.8 104.8 137.5 163 201 Exhaust loss kcal/kg 2.8 2.5 2.4 3.0 3.8 6.5 Operate the condenser at design v The exhaust loss is the lowest at 0.08 kg/cm 2 (a) vacuum v How to maintain the design vacuum Reduce the quantity of water supply Optimise the operation of cooling tower fan Control on Ejector v Equivalent reduction in steam consumption - 300 kg/hr Annual Saving - Rs 27.00 Lakhs 3. High efficiency Micro turbine v Waste heat recovery boiler in operation v Operating steam parameters Pressure - 38 kg/cm 2 Saturated steam Capacity - 12 13 tons/hr v Steam utilised for turbo driven circulating water pump & exhaust steam for process High efficiency Micro turbine v Power generation potential partially utilised v Specification of circulation water pump Flow - 280 m 3 /hr Head - 48.9 m v Power requirement - 60 kw Power generation potential v Conventional turbine with exhaust in superheated condition Turbine single stage v Power generation potential 75 kw v Latest double stage turbine gives excellent potential Power generation opportunity - 500 kw
Steam and Power Costing Power generation potential Pr 38 kg/cm 2(g) Temp sat Flow 12 tons/hr 500 kw v Supplier guaranteed upto - 560 kw v Existing circulation water pumps needs to Two stage turbine ~ be electrical motor driven Pr 5 kg/cm 2 (g) Temp 158 oc Dryness fraction 0.93 v Net power generation - 500 kw Excellent potential for power generation Annual Saving - Rs 105.60 Lakhs Investment - Rs 70.00 Lakhs Payback period - 8 months 4.Steam Ejector / Vacuum Pump Install vacuum pump in lieu of steam ejector v Presently steam ejector is in operation Existing Steam v Design specification Working steam pr - 10 ata Condenser or vessel CW Proposed Steam ejector Steam temperature - 350 o C Steam consumption - 1000 kg/hr Suction pressure - 0.035 ata Capacity of dry air - 20.4 kg/hr Water ring vacuum pump Dry air + water vapour - 65.4 kg/hr Install vacuum pump in lieu of steam ejector v Main steam utilised as auxiliary steam v From the turbine characteristic curve Power generation potential for 1 ton/hr of steam -250 units v Install vacuum pump in lieu of steam ejector v Vacuum pump specification Pressure - 660 mmhg Capacity - 0.3 m 3 /sec v Estimated power consumption - 47 kw Install vacuum pump in lieu of steam ejector v Temperature gain in ejector condensor - 10 o C v Increase in steam consumption in deaerator - 1 ton/hr steam at 5.5 kg/cm 2 v Reduction in power generation - 100 units/ton v Net benefit - 100 kw Annual Saving - Rs 48.00 Lakhs Investment - Rs 15 Lakhs Payback period - 4 Months
5. Install Thermo compressor and recover flash steam from feed tank v Condensate from digester Collected in feed tank v Heat balance of feed tank and estimation of flash steam quantity indicate q Flash steam quantity is about 2.55 tons/hr Water in feed tank @ 0.3 kg/cm 2 170 TPH Flash Steam to atomos phere (Y) kg Flash vessel Install Thermo compressor and recover flash steam from feed tank Motive Steam @ 33 kg/cm 2 (abs) Temp 390 o C Flow 1.5 tons/hr (approx) LP Steam @ 0.1 kg/cm 2 (abs) Temp 100 o C Flow 2.0 tons/hr Discharge Steam @ 2.5 kg/cm 2 (abs) Flow 3.5 tons/hr 98 C Condensate (1 Y) kg Install Thermo compressor and recover flash steam from feed tank v Good potential to recover the flash steam v Best option - Installing thermo compressor and injecting back to low pressure header To sum up vtremendous potential for Energy Saving in Boilers & Steam systems vbecome a world class energy efficient unit Implement the latest technologies Annual saving - Rs 28.16 Lakhs Investment - Rs 30.00 Lakhs Payback - 13 Months Learning the best practices from other sector / industries Contact S Karthikeyan Senior Counsellor CII-Sohrabji Godrej Green Business Centre Confederation of Indian Industry Southern Regional Headquarters 98/1 Velacherry Main Road, Guindy Chennai 600 032 Email : s.karthikeyan@cii.in Mobile : +91 98400 02983 Website : www.greenbusinesscentre.com / www.cii.in Thank You