1. UNIT 4:Energy Conservation

2. Energy Conservation In Electrical Field Energy is the primary and the most universal measures of all kinds of work by human being and nature. Electrical energy is proved to be an ideal energy in all sorts of energy available in nature. Energy conservation means reduction in growth of energy consumption and is measured in physical terms Energy conservation is the practice of decreasing the quantity of energy used while achieving a similar outcome of end use. Energy conservation also means reduction or elimination of unnecessary energy used and wasted.

3. EC in Transmission & Distribution In India the power transmission and distribution (T&D) system is a three tire structure comprising of state grids, regional grids and distribution network. To meet the energy demand power system networks are interconnected through INTRA- REGIONAL LINK Power losses in T&D system can be classified as Technical losses and Commercial losses.

4. Technical Losses In T&D System:

5. Energy Conservation In Transmission Line: To reduce line resistance solid conductors are replaced by stranded conductors (ACSR or AAC) and by bundled conductors in HT line. High Voltage Direct Current (HVDC) is used to transmit large amount of power over long distances or for interconnections between asynchronous grids By transmitting energy at high voltage level reduces the fraction of energy lost due to Joule heating. As load on system increases terminal voltage decreases.

6. Voltage level can be controlled by using voltage controllers and by using voltage stabilizer To control receiving end voltage, reactive power controllers or reactive power compensating equipments such as Static VAR controllers are used.

7. Energy Conservation In Distribution Line (A) Optimization of distribution system: The optimum distribution system is the economical combination of primary line (HT), distribution transformer and secondary line (LT), To reduce this loss and improve voltage HT/LT line length ratio should be optimized. Balancing of phase load- As a result of unequal loads on individual phase sequence, components causes over heating of transformers, cables, conductors, motors. Thus, increasing losses and resulting in the motor malfunctioning under unbalanced voltage conditions. Harmonics: With increase in use of non-linear devices distortion of the voltage and current waveforms occurs known as Harmonics. Due to presence of harmonic excessive voltage and current occur in transformers terminals.

8.  Cost of fuel (input energy) is 85% of the total operating costs.  8 to 10% of final output (electrical energy) is consumed for its own auxiliaries.  Due to the above, energy efficiency issues are of the highest priority in Thermal Power Station.  Energy Audit becomes mandatory under Energy Conservation Act, 2001. ENERGY CONSERVATION IN THERMAL POWER STATION

10. ENERGY CONSERVATION IN THERMAL POWER STATION(B)

11. ENERGY CONSERVATION IN THERMAL POWER STATION

13. ENERGY CONSERVATION IN Illumination The use of timer switches or photo cells to switch off lights during unwanted hours should be considered. Replace existing tungsten filament lamps with compact fluorescent lamps/LED Use electronic chokes and low loss magnetic ballasts for fluorescent lubes. Removal of light diffusers can reduce the number of lamps required by up to 20 % for the same luminance. Lamps and luminaries should be cleaned regularly. Soundness of capacitors and chock starters etc. should be checked periodically Replace incandescent lamps with circular fluorescent lamps.

14. ENERGY CONSERVATION IN Illumination Install electronic ballasts when conventional ballasts wear out.ballasts Use light oppressive sodium lamps and instead of mercury vapors lamps and ballasts. Lower the height of light fixtures in high ceiling areas, wherever possible. Lighting should be reduced in non-productive areas. Translucent corrugated roof sheets should be used to allow day light inside the factory. Aluminum baffles may be used to avoid glare at different points. Use electronic dimmer dimming circuits. Microprocessial or controlled lighting management system

15. ENERGY CONSERVATION IN PUMPING SYSTEM Ensure adequate NPSH(Pump suction performance) at site of installation Ensure availability of basic instruments at pumps like pressure gauges, flow meters. Operate pumps near best efficiency point. Modify pumping system and pumps losses to minimize throttling.

16. Adapt to wide load variation with variable speed drives or sequenced control of multiple units. Stop running multiple pumps - add an auto-start for an on-line spare or add a booster pump in the problem area. Use booster pumps for small loads requiring higher pressures Increase fluid temperature differentials to reduce pumping rates in case of heat exchangers.

17. Balance the system to minimize flows and reduce pump power requirements. Conduct water balance to minimize water consumption Avoid cooling water re-circulation in DG sets, air compressors, Refrigeration systems, cooling towers feed water pumps, condenser pumps and process pumps

18. Provide booster pump for few areas of higher head Replace old pumps by energy efficient pumps In the case of over designed pump, provide variable speed drive, or downsize / replace impeller or replace with correct sized pump for efficient operation Reduce system resistance by pressure drop assessment and pipe size optimization

19. ENERGY CONSERVATION IN WASTE HEAT RECOVERY SYSTEM Waste heat is heat, which is generated in a process by way of fuel combustion or chemical reaction, and then “dumped” into the environment even though it could still be reused for some useful and economic purpose. The essential quality of heat is not the amount but rather its “value”. The strategy of how to recover this heat depends in part on the temperature of the waste heat gases and the economics involved.

20. Large quantity of hot flue gases is generated from Boilers, Ovens and Furnaces. If some of this waste heat could be recovered, a considerable amount of primary fuel could be saved. The energy lost in waste gases cannot be fully recovered.

21. Heat Losses –Quality Depending upon the type of process, waste heat can be rejected at virtually any temperature from that of chilled cooling water to high temperature waste gases from an industrial furnace. Usually higher the temperature, higher the quality and more cost effective is the heat recovery. Typical examples would be preheating of combustion air, space heating, or pre-heating boiler feed water or process water.

22. Heat Losses – Quantity In any heat recovery situation it is essential to know the amount of heat recoverable and also how it can be used.

23. Classification and Application

24. Benefits of Waste Heat Recovery Direct Benefits: Recovery of waste heat has a direct effect on the efficiency of the process. This is reflected by reduction in the utility consumption & costs, and process cost.

25. Indirect Benefits: a) Reduction in pollution: A number of toxic combustible wastes such as carbon monoxide gas, sour gas, carbon black off gases, oil sludge, and other plastic chemicals etc, releasing to atmosphere if/when burnt it serves dual purpose i.e. recovers heat and reduces the environmental pollution levels. b) Reduction in equipment sizes: Waste heat recovery reduces the fuel consumption, which leads to reduction in the flue gas produced. This results in reduction in equipment sizes of all flue gas handling equipments such as fans, stacks, ducts, burners, etc.

26. c) Reduction in auxiliary energy consumption: Reduction in equipment sizes gives additional benefits in the form of reduction in auxiliary energy consumption like electricity for fans, pumps etc..

27. Development of a Waste Heat Recovery System(A) Understanding the process Understanding the process is essential for development of Waste Heat Recovery system. This can be accomplished by reviewing the process flow sheets, layout diagrams, piping isometrics, electrical and instrumentation cable ducting etc. Detail review of these documents will help in identifying: a) Sources and uses of waste heat b) Upset conditions occurring in the plant due to heat recovery c) Availability of space d) Any other constraint, such as dew point occurring in an equipments etc.

28. Waste Heat Boilers Waste heat boilers are ordinarily water tube boilers in which the hot exhaust gases from gas turbine, pass over a number of parallel tubes containing water. The water is vaporized in the tubes and collected in a steam drum from which it is drawn off for use as heating or processing steam. Typical applications of waste heat boilers are to recover energy from the exhausts of gas turbines, reciprocating engines, incinerators, and furnaces.

30. What is Cogeneration?(B) A cogeneration system is the sequential or simultaneous generation of multiple forms of useful energy (usually mechanical and thermal) in a single, integrated system. CHP systems consist of a number of individual components – prime mover (heat engine), generator, heat recovery, and electrical interconnection – configured into an integrated whole. The type of equipment that drives the overall system (i.e. the prime mover) typically identifies the CHP system.

31. The Benefits of Cogeneration Provided the cogeneration is optimized in the way (i.e. sized according to the heat demand), the following benefits can be obtained: Increased efficiency of energy conversion and use. Lower emissions to the environment, in particular of CO 2, the main greenhouse gas.

32. In some cases, biomass fuels and some waste materials such as refinery gases, process or agricultural waste are used. These substances which serve as fuels for cogeneration schemes, increases the cost- effectiveness and reduces the need for waste disposal. Large cost savings, providing additional competitiveness for industrial and commercial users while offering affordable heat for domestic users also.

33. An opportunity to move towards more decentralized forms of electricity generation, where plants are designed to meet the needs of local consumers, providing high efficiency, avoiding transmission losses and increasing flexibility in system use. This will particularly be the case if natural gas is the energy carrier(B)(A) An opportunity to increase the diversity of generation plant, and provide competition in generation. Cogeneration provides one of the most important vehicles for promoting liberalization in energy markets.

34. In a fluorescent lighting system, the ballast regulates the current to the lamps and provides sufficient voltage to start the lamps. Without a ballast to limit its current, a fluorescent lamp connected directly to a high voltage power source would rapidly and uncontrollably increase its current draw