Energy Efficiencies Opportunities for SME’s

… An effective tool to sustain bottom line

Tuesday, April 2, 2013

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Energy Scenario

By 2030, World’s energy needs would be well over 50% higher

China & India together account for 45% of the increase in global primary energy demand

India - one of the fastest growing economies in the world, is poised to grow at around 7% on moderate term

India’s energy demand is expected to be more than double by 2030. India will need huge new power generation capacity, which needs financial & natural resources

Heavy utilization of depleting conventional energy sources. Demand supply gap, continuous rise in energy tariffs / rates

India’s energy intensity is higher, indicates inefficient use of energy but also substantial scope of energy savings

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What is Energy Efficiency & Conservation (EEC)?

Energy Efficiency refers using “less energy to provide better or at least same quality & productivity”

Energy Conservation refers to “continuous group efforts made to reduce energy consumption”

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Why EEC?

Reduction in energy consumption results in energy costs reduction - improvement in bottom line

Reduction in energy costs results in production cost reduction – larger market share / improvement in top line

In line with legal framework – Energy Conservation Act 2001

Mandatory conduct of energy audits, once in 3 years

Renewable Energy Purchase Obligation Mandatory use of renewable energy (solar & non solar), every year

Perform Achieve & Trade Scheme Mandatory reduction in specific energy consumption, every year

Contribution towards improving national energy security, reducing fresh power generation capacity addition & reducing global worming

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Energy Conservation

Energy Conservation is not curtailment of energy use. Energy Conservation is minimization of wastage of energy

resources. Energy Conservation is maximization of productivity of available

energy resources. Energy Conservation is increased profitability for the Nation. Energy Conservation is also a social obligation.

Energy Conservation By: Use of energy efficient practices. Use of energy efficient technologies. Reducing wastage – improving efficiency. Use of alternative sources of energy.

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Energy Saving Potential

Estimated total conservation potential of the Indian industry is around 23% of the total energy used by this sector

Over 5% to 8% saving is possible simply by better housekeeping and another 10% to 15% with small investment towards low - cost retrofitting, use of energy-efficiency devices and controls, etc.

Quantum of saving is much higher if high cost measures like major retrofitting, process modifications, etc. are considered

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Following factors affect fuel economy in Industrial Furnace

Complete combustion with minimum excess air Proper heat distribution Maintaining required temperature of the furnace Reduction of heat losses from furnace opening Minimizing wall losses Control of furnace draft Optimum capacity utilization Waste heat recovery from furnace flue gases

Sensible heat in flue gas can be salvaged by Charge preheating Preheating of combustion air Utilizing waste heat for other process like generation of steam

or hot water

Factors Affecting Fuel Economy

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Following factors affect on furnace efficiency:

Under loading due to poor hearth loading and improper production scheduling

Improper designing Use of inefficient burners Absence of waste heat recovery, instruments and control Improper maintenance or operation Improper insulation or refractories

Factors Affecting Furnace Performance

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Furnaces come in wide variety of configurations and applications.

Gas and oil are the commonly used as fuel.

Furnaces efficiencies depend on design, temperature and operation. Furnace temperatures vary from 600 0C for tempering to 1200 0C or more for forging. Higher temperature require higher gas temperature. Higher exhaust temperature, higher exhaust losses and low efficiencies.

Furnace efficiencies can be 10% to 30%. A proper heat balance of a furnace is necessary to improve operations.

Energy Conservation in Furnace

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Opportunities:

Complete combustion with minimum excess air. Operation at optimum temperature. Reducing heat losses through opening. Proper insulation. Better capacity utilization. Waste heat recovery.

Energy Conservation in Furnace

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Minimum Excess Air:

Proper selection of burners, monitoring of excess air, cold air ingress control are required.

Control excess air in furnaces. A 10% drop in excess air amounts to 1% saving of fuel in furnaces. For an annual consumption of 3000 kl. of furnace oil. This means a saving of Rs 3 Lacs.

The following table shows the quantum of losses.Excess Air Heat loss thru flue gas25% 48%50% 55%75% 63%100% 71%

Energy Conservation in Furnace (Contd.)

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Operate at Optimum Temperature:

Provision of proper temperature control is must. Operator judgment can be erroneous. Operation at higher temp. Leads to higher losses and also quality problems.

Optimum temperature of forging furnace is around 1150 0C

Minimise Wall Losses:

Providing proper insulation on all surfaces is a must. Use of insulation material having low conductivity, light weight

and hence low thermal mass have dramatically improved efficiencies.

Can be used for 1200 0C TO 1400 0C.

Energy Conservation in Furnace (Contd.)

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Waste Gas Heat Recovery:

Waste gas temperature in furnace are much higher i.e. Approx. 600 0C to 1200 0C

Preheating of combustion air

Waste heat can be used for charge preheating.

For combustion air preheating various type of regenerator, recuperator are used.

Energy Conservation in Furnace (Contd.)

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Reduce Losses Through Opening:

Observations show that a furnace operating at a temperature of Approx. 1000°C having an open door (1500mm*750mm) results in a fuel loss of 10 lit/hr. For a 4000 hrs. furnace operation this translates into a loss of approx. Rs. 4 Lacs per year.

Proper closing of doors, lids etc. Is must for optimum operation. Radiation losses are given as follows:

Energy Conservation in Furnace (Contd.)

Temperature (0C) Heat Loss kW/m2

555 25

833 64

1115 161

1400 387

Thank You