Energy Conservation Techniques

Prepared by

Mansi Vithalani

Topics To be Covered

What is Energy Conservation? Energy Conservation in Different areas

Industrial sector Power generation, transmission & distribution sector

Case study: Cement Industry

Transport sector Agriculture sector Domestic sector

Introduction What is Energy Conservation? Energy Conservation and Energy Efficiency are separate, but related

concepts. Energy conservation is achieved when growth of energy consumption

is reduced, measured in physical terms. Energy Conservation can, therefore, be the result of several processes or developments, such as productivity increase or technological progress.

On the other hand Energy efficiency is achieved when energy intensity in a specific product, process or area of production or consumption is reduced without affecting output, consumption or comfort levels.

Promotion of energy efficiency will contribute to energy conservation and is therefore an integral part of energy conservation promotional policies.

Industrial sector

Thermal Energy Conservation in industry General Undertake regular energy audits. Plug all oil leakage. Leakage of one drop of oil per second amounts to

a loss of over 2000 liters/year. Filter oil in stages. Impurities in oil affect combustion. Pre-heat the oil. For proper combustion, oil should be at right viscosity

at the burner tip. Provide adequate Pre-heat capacity. Incomplete combustion leads to wastage of fuel. Observe the colour of

smoke emitted from chimney. Black smoke indicates improper combustion and fuel wastage. White smoke indicates excess air & hence loss of heat. Hazy brown smoke indicates proper combustion.

Use of Low air pressure “film burners” helps save oil upto 15% in furnaces.

Furnace Recover & utilize waste heat from furnace flue gas for preheating of

combustion air. Every 21 0C rise in combustion air temperature results in 1% fuel oil savings.

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. (Cost of furnace oil-Rs. 10 per litre).

Reduce heat losses through furnace openings. Observations show that a furnace operating at a temperature of 1000 0C 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.

Boiler Recover heat from steam condense. For every 60C rise in boiler feed

water temperature through condense return, there is 1% saving in fuel. Improve boiler efficiency. Boilers should be monitored for flue gas

losses, radiation losses, incomplete combustion, blow down losses, excess air etc. Proper control can decrease the consumption upto 20%.

Use only treated water in boilers. A scale formation of 1mm thickness on the waterside would increase fuel consumption by 5-8%.

Stop steam leakage. Steam leakage from a 3 mm-diameter hole on a pipeline carrying steam at 7kg/cm2 would waste 32 kl of fuel oil per year amounting to a loss of Rs. 3 Lacs.

Maintain steam pipe insulation.

Electrical Energy Conservation in industry General Improve power factor by installing capacitors to reduce KVA demand

charges and also line losses within plant. Improvement of power factor from 0.85 to 0.96 will give 11.5%

reduction of peak KVA and 21.6% reduction in peak losses. This corresponds to 14.5% reduction in average losses for a load factor of 0.8.

Avoid repeated rewinding of motors. Observations show that rewound motors practically have an efficiency loss of upto 5%. This is mainly due to increase in no load losses. Hence use such rewound motors on low duty cycle applications only.

Use of variable frequency drives, slip power recovery systems and fluid couplings for variable speed applications such as fans, pumps etc. helps in minimizing consumption.

Illumination Use of electronic ballast in place of conventional choke saves

energy upto 20%. Use of CFL in place of GLS lamp can save energy upto 70%. Clean the lamps & fixtures regularly. Illumination levels fall by 20-

30% due to collection of dust. Use of 36W tubelight instead of 40 W tubelight saves electricity by

8 to 10%. Use of sodium vapour lamps for area lighting in place of Mercury

vapour lamps saves electricity upto 40%.

Compressed Air Compressed air is very energy intensive. Only 5% of electrical energy

are converted to useful energy. Use of compressed air for cleaning is rarely justified.

Ensure low temperature of inlet air. Increase in inlet air temperature by 30C increases power consumption by 1%.

It should be examined whether air at lower pressure can be used in the process. Reduction in discharge pressure by 10% saves energy consumption up to 5%.

A leakage from a ½” diameter hole from a compressed air line working at a pressure of 7kg/cm2 can drain almost Rs. 2500 per day.

Air output of compressors per unit of electricity input must be measured at regular intervals. Efficiency of compressors tends to deteriorate with time.

Refrigeration & Air Conditioning Use of double doors, automatic door closers, air curtains, double

glazed windows, polyester sun films etc. reduces heat ingress and air-conditioning load of buildings.

Maintain condensers for proper heat exchange. A 50C decrease in evaporator temperature increases the specific power consumption by 15%.

Utilization of air-conditioned/refrigerated space should be examined and efforts made to reduce cooling load as far as possible.

Utilize waste heat of excess steam or flue gases to change over from gas compression systems to absorption chilling systems and save energy costs in the range of 50-70%.

Cooling Towers Replacement of inefficient aluminum or fabricated steel fans by

moulded FRP fans with aerofoil designs results in electricity savings in the range of 15-0%.

A study on a typical 20ft. diameter fan revealed that replacing wooden blade drift eliminators with newly developed cellular PVC drift eliminators reduces the drift losses from 0.01-0.02% with a fan power energy saving of 10%.

Install automatic ON-OFF switching of cooling tower fans and save upto 40% on electricity costs.

Use of PVC fills in place of wooden bars results in a saving in pumping power of upto 20%.

Power Generation, Transmission and Distribution Sector

Performance Improvement of Existing Power Plant

1. Boilers

Use of multi fuel fired boiler

Remove the manual operation in fuel feeding, ash removal & boiler control

Use of microprocessor based measurement and control instruments

Maximize thermal efficiencies

Minimize boiler blowdown

2. Motors

Carry out motor load survey

Substitute motors having low loads by smaller size motors or change connection to star from delta

Use soft starters or energy savers

Explore possibility of replacing motor with high efficiency motor

3.Furnace

4.Lighting

5.Insulation Use of Co-generation Plants Improved power transmission lines & reduction in line losses

HVAC transmission

Proper size of conductor

Better line insulation

Improved power factor

HVDC transmission

Energy Conservation in Cement Industry

Fuel Due to frequent variations in the quality of coal, inadequate

supplies and transportation bottlenecks go for substitute fuels like, lignite, rice-husk, petroleum coke etc.

Use alternate fuels such as natural gas and pet coke. Use industrial and agricultural combustible wastes as

supplementary fuel.

Power Supply: For uninterrupted power supply have your own captive power

plant.

Operational Measures: Rationalize compressed air utilization. Use energy efficient equipment like high efficiency fans Carry out Heat and gas balance Recover waste heat of preheater and use for cogeneration of power. Increase utilization of waste products generated by other industries(substitution

like use of fly ash and petroleum coke, the by products of thermal power and refinery industry respectively)

Install fly ash handling & feeding system. Reduce energy consumption in manufacturing at each stage & monitor energy

performance of the plant. Optimize raw mix Use low ash coal

Prevent idle running of equipment by providing interlooking arrangement and operating with PLC system. Generate daily report on idle running of equipment, also in terms of monetary losses.

Repair steam leaks Adopt preventive maintenance approach Reinforce heat insulation Establish efficient management information system for identifying

various important parameters for efficient operation of the equipment and taking timely remedial measures.

Minimize waste by installing efficient dust collector equipment. Carry out energy audits.

Air Compressor Stop use of compressed air for floor cleaning. Check for compressed air leakage and arrest it. Switch off one compressor if requirement can be met by balance

operating compressors. Reduce compressed air pressure from 8 Kg/Cm2 to 7.0 Kg/Cm2

where ever possible to conserve energy, when required pressure at usage point is 6.0 Kg/Cm2

Motors Prevent idle operation of the motors Replace underloaded / overloaded motors with proper size motors.

Replace the motors with energy efficiency motors.

Transformer If possible switch off one transformer running under loaded in

parallel. Maintain all transformers at a loading of 70 to 80 % of rated capacity to minimize loss component (no load losses).

Try to have separate transformer for lighting where voltage can be kept low.

Power Factor Improve power factor by regular checking of current of all the

capacitors and their timely replacement. Install Automatic power factor correction device to have power factor

of 0.99 to 1.00

Lighting Replace 40W Tube light by slim 28W Tube light and electromagnetic

choke with electronic choke. Replace 400 Watt Mercury Vapour lamps with 250 Watt sodium

vapour lamps or 250 W metal hallide lamps. Replace 250 Watt Mercury Vapour lamps with 150 Watt sodium

vapour lamps or 150 W metal hallide lamps. Provide more transparent sheet instead of asbestos sheets to use

natural light. Install energy saver for reducing the lighting load. Prevent unnecessary lighting of the electric lamps. Rationalize lighting in identified areas i.e remove excess lighting in

identified areas. Also relocate lighting, if necessary.

Transport Sector

Drive between 45-55 Km/H Keep your engine healthy Drive in the Correct Gear Don’t wait for your car to warm up Good Braking Habits Keep your Foot off the Clutch Watch Your Tyre Pressure When you stop your car, stop engine   Use the Recommended grade of oil Plan Your Route Reduce Loads

Agriculture Sector saving diesel in tractors

badly maintained tractor wastes up to 25 % of precious diesel. Stop diesel leaks Turn your engine off, when you stop Worn out tyres reduce pulling power. Replug tyres on time. While refitting

tyres, make sure the ‘V’ treads point downwards when viewed from the front

Plan your field run. Plough according to a planned layout that reduces idle running, backtracking and awkward turn.

saving diesel in Lift Irrigation Pumps Use good quality foot valve having less resistance Educate the farmers by the dealers of irrigation pump sets for better

energy conservation Less numbers of bend in pipe lines Decide model & capacity of pump set according to head & pressure

Domestic SectorIn Kitchen, A few minutes of planning ensures a big fuel saving while cooking Pressure cooking saves fuel Use optimum quantity of water Reduce the flame when boiling starts Soak before cooking Shallow, wide vessels save fuel Put the lid on heat losses The small burner saves fuel A clean burner helps save fuel   Clean vessels help too Allow frozen food to reach room temperature before cooking Plan your meal timings

Washing machine Use washing machine to its full capacity Do not use dryer for drying the clothes at least in the summer

season/ dry season

Refrigerator Do not open and close the door frequently Open the door up to half of its opening capacity not up to the 90

degree or more Do not keep hot food/milk in the freeze without its proper

cooling Keep the freeze at least 6 to 12 inches away from the wall so

condenser coil gets free air circulation Do not allow direct sunlight on the freeze

Air Conditioner Remove all obstacles, which are in front of A.C. Remove dust from the grill regularly Turn the A.C. ‘off’ before half an hour of leaving the room Insulate wall and ceiling of the room as far as possible by means

of fiberglass or wood Grow more trees around your house Avoid direct sunlight on the heat exchanger of the A.C. unit

Thank You…!