Pages

Tuesday, January 7, 2014

Reconditioning old batteries is a great way to help the environment.

How you can make thousands by purchasing old batteries and selling them as reconditioned ones for massive profits.



Li-ion: The Battery Of Choice!





The trend of battery-powered laptops and other portable equipment becoming smaller and more power hungry led to the creation of lithium-ion (Li-ion) rechargeable batteries. The electrodes used in these batteries are made of lightweight lithium and carbon, making them compact and lightweight. They offer a far better performance when compared to the more traditional rechargeable batteries.
Lithium-ion batteries often used in laptops are different from primary lithium batteries used in cameras. Li-ion technology was introduced in 1990 and has over the years emerged as a superior source of power for a variety of applications. With the demand and growth of the electronic consumer market, Li-ion batteries have witnessed unprecedented popularity, and are used in laptops, iPhones, iPods, PDAs and other electronic equipment.
It is energy density that determines the size and weight of batteries. The idea is to minimize both the weight and size of the portable equipment for today’s market, and Li-ion batteries give designers this ability, with their significantly better volumetric energy density. These batteries are not only used in consumer electronics, but also in aerospace, defense and automotive applications were high energy density is used.
Since Li-ion cells have a much higher operating voltage than others, fewer cells are needed to build a pack, thus reducing the battery assembly costs and increasing reliability.
There is no one reason for their huge acceptance in the rapidly growing market. The numerous benefits include higher energy density, better cycle life, higher voltage per cell, great low temperature performance, simple battery management, slower self discharge when not in use – about 5% in a month, easy to charge as well as being environmental friendly too.
One of the main benefits of lithium-ion batteries is the fact that they have no “memory effect,” which means they do not have to be completely discharged before they are recharged, like so many other batteries. The batteries also stay new for a long time and can take hundreds of charge and discharge cycles.
Li-ion batteries are also easy to use in all sorts of devices because they can be created in different shapes and sizes.
Having talked about all the positive features about Li-ion batteries, one cannot help but wonder if anything can be so perfect. Well, the only flaw that has been found is their ability to burst into flames – very rarely, perhaps a couple of battery packs in a million.
Li-ion batteries are the most energetic and powerful batteries around, and one cannot go wrong using them, and the lack of memory effect makes them all the more attractive to consumers.






Easy Techniques To Improve Battery Life!


All batteries will fail at some point, when they have been in use for longer periods of time. But premature battery failure is one of the main frustrations people face.
Common thinking is that turning devices off extends battery life, but what happens is the opposite. Devices consume more power when they are starting up, so turning them off is not such a good idea if they are going to be switched on frequently.
Cars and Other Automobiles
It is important to protect the car battery from high under the hood temperatures with the use of a case or a heat shield. The battery life can be extended by keeping the battery charged at all times. Electrolyte levels will have to be checked frequently during the hot months. A recent study revealed that relocating the battery outside the engine compartment has increased its life by almost eight months. Car manufacturers are relocating the starting battery to the passenger compartment or the trunk to avoid under the hood temperatures. It also helps to use wet batteries vented to the outside or cells that do not produce gas when recharged. Based on the driving of each individual, some batteries are undercharged and this leads to sulfation, where lead sulfate gets accumulated, reducing the battery capacity. An external battery can be used for charging.
For any battery, the most important factor to consider is the temperature. Ensuring they are not exposed to too much heat can extend the life of a battery. It is common sense that high temperatures lead to faster chemical reactions. They need to be watered more often with only deionized or demineralized water. However, rain water is a good substitute in an emergency. In addition to the temperature, a reduction in the number of discharge/charge cycles significantly improves battery service life. In extremely cold climates, the car battery needs to be continuously kept fully charged when not in use.
Portable Electronic Devices
Battery life can be increased for iPods, cell phones, laptops etc. by lowering the brightness when not necessary. For example, when using these devices in a dark room, it is not necessary to set the brightness to 100%. The brightness can be lowered enough so that the screen can be seen without exerting any strain on the eyes can be done. The amount of time the backlight stays on can also be decreased. For iPods it doesn’t have to stay on for 10 seconds, 2 seconds should be good enough. Laptops can be set in hibernate mode when not in use.
One most important point that not many people are aware of is that turning down the volume increases battery life. Use headphones that are louder and leave the volume at 50%.
Background applications are power hungry monsters. Stop everything that is not being used. Defragmenting the hard drive once in a while helps decrease file scatter on the hard drive and uses up less power. Send the computer into standby mode after a certain period of inactivity as it conserves battery. Although, standby resume also uses some power but not as much as starting up. Interestingly, leaving a CD or DVD in the drive can decrease battery life, as it hogs power whenever the drive spins up.
In Wi-Fi Applications
Battery life in Wi-Fi apps can be prolonged by either increasing battery capacity or reducing Wi-Fi product power consumption and through control methods. It is easy to increase battery capacity; however, due to technological limits, it may lead to an increase in cost and size of the battery. That brings us to the option of reducing power consumption, which can be done by prolonging the standby time and shortening the time of the active cycle. You can also turn off the WiFi on the iPod when not in use as it consumes a large amount of life.
These techniques of low power consumption can improve battery life dramatically. Most of them are common sense usage techniques and can easily be made part of our daily lives.







What Makes Ni-Cd Rechargeable Battery Popular!


Nickel-Cadmium or the Ni-Cd rechargeable batteries are a type of alkaline storage battery, classified as a secondary battery. As the name suggests, they are made from two chemical elements, nickel hydroxide, cadmium and an alkaline electrolyte, which is usually a solution of Potassium Hydroxide.
Invented in I899 by Waldemar Jungner of Sweden, their practical application was only made possible after 50 years, with the development of the sealed battery by Frenchman, Neumann.
The Ni-Cd batteries are used in a variety of applications all over the world. They comprise of a positive electrode plate that uses nickel hydroxide as the main material, and a negative electrode plate that uses cadmium compound as the main active material.
There are two varieties of Ni-Cd batteries: sealed and vented. The smaller sealed variety is used in toys and other portable electronics. Specialty Ni-Cd batteries are used in wireless and cordless telephones, old motherboards, laptops cell phones and other applications. These batteries can supply high surge currents making them perfect for use in remote-controlled cars, boats, airplanes, camera flash units etc.
When compared to other rechargeable batteries, Ni-Cd is beneficial in many ways. They are strong and cannot be damaged easily, with the ability to withstand deep discharges for longer periods. They also have more endurance to the charge and discharge cycles. These batteries are lightweight and smaller even when compared to the lead-acid battery, making them a preferred choice in aircrafts where size and weight are crucial factors.
However, there is one drawback, if you can call it that. Ni-Cd are known for their “memory effect.” Memory effect is when batteries “think” that they are fully charged even when they are not. If your battery is about 80% charged, it thinks it is 100% charged, and due to this thinking, does not charge any further even when placed on the charger. The problem is that when gadgets with Ni-Cd batteries are used, they last for a shorter time because of being charged less. This problem mostly affects older batteries and not the brand new ones. However, there is a solution to this memory effect – that of performing a “full recharge cycle,” which is to let the gadget discharge completely before recharging it again. For example, recharge only when your cell phone starts beeping.
Now that the memory effect has been taken care of, let us look at some more benefits of Ni-Cd rechargeable batteries. They can be used for as many as 500 full recharge cycles, which is on the higher side. The charge is also retained for a longer time when not in use. Losing only 1% of charge per day takes almost four months for the battery to be completely discharged.
In spite of the Ni-Cd batteries costing more, having slightly lower voltage and the memory effect; their demand has not diminished because they have a significantly longer total lifetime than alkaline cells, which is what consumers look for when buying batteries – a long lasting battery.






Ni-MH: The Long Life Battery!

For today’s lifestyles, the most important attribute to consider is mobility. Advanced electronic devices such as portable computers and cell phones allow people to perform much more effectively than ever before. With mobility comes the increased need for portable power sources.
Fortunately, this advancement in electronics is matched with improvements in batteries that power these devices. Ni-MH batteries provide much more power than the Ni-Cd batteries and also eliminate any concerns on the usage of heavy metals in the making of these cells. The exciting new technology used in the sealed Ni-MH rechargeable batteries provides optimum results for battery-powered devices, in terms of performance and environmental friendliness.
Introduced to the commercial market in 1988, the Ni-MH battery is still at an early stage of maturity, but has already proven to be an attractive power source for today’s devices.
There are several benefits of Ni-MH batteries, such as a higher energy density, which is almost 40% more than the nickel-cadmium batteries. This increase in energy density helps with providing longer run times, which means longer service life than ordinary batteries of the same size. They also charge much faster, in approximately one hour. They are safe to use and designed to withstand a variety of abusive conditions in consumer devices. Unlike the Ni-Cd batteries and other battery systems, they are environmental friendly, as there is no fear of cadmium, mercury or lead toxicity.
Today, the Ni-MH battery is hugely popular with high-end portable electronic devices where the performance of the battery translates into run-time, which is a major consideration for a consumer and influences their decision in the purchase of product. The reduced weight and volume also play an important role.
Ni-MH batteries are similar to Ni-Cd batteries as they use the same technology. The only difference is that they use hydrogen-absorbing negative electrode instead of the cadmium-based electrode used in Ni-Cd. This small change increases the electrical capacity of the battery as well as eliminates the toxicity problem. The problem of “memory” does not exist in the Ni-MH batteries, as there is no cadmium used.
These batteries are designed to ensure maximum safety with a safety vent, to avoid build up of pressure in case of being exposed to high temperature, charged excessively or abused in other ways. They can also be used in any position and the only maintenance that is needed is to keep them dry and clean while in use as well as in storage. Whether stored when charged or discharged, nothing happens to these batteries.






The Benefits Of Lead-Acid Batteries!


Lead-acid batteries or “starting batteries,” as they are also called, are the oldest rechargeable batteries in existence and the first used for commercial use. They have dominated the market for over 100 years, ever since their invention in the 1850s by Gaston Plante, a French engineer, and continue to weave their magic to this day. The surge of new batteries in the market has not lessened their importance.
Today, lead-acid are cost-effective and their ability to supply high surge currents, makes them the most viable option for use in cars and other motor vehicles, as they meet the requirement of the high current that automobile starter motors need.
Car batteries are used to start diesel or gasoline engines, as they provide the electricity needed for starter motors, ignition, lights and other electronic features. Most of the car batteries are lead-acid batteries and the energy is produced through a chemical process that involves lead, lead oxide and a liquid electrolyte solution. Plates of lead and lead oxide sit in the electrolyte solution that is made up of a small percentage of sulfuric acid and more of water. This causes a chemical reaction and electrons are released, which are all routed through conductors in the battery to generate the electricity needed for the car.
When lead batteries are discharged, sulfuric acid forms on the lead plates, and when they are recharged again, this sulfuric acid on the plates breaks back into its constituent lead and lead oxide.
Some car batteries need maintenance in the form of adding water. It was during the 1970s that maintenance-free sealed lead-acid batteries were developed and they can be used in any position, sideways or upside down without the risk of acid leakage. The liquid electrolyte is gelled into separators and sealed. Safety valves are used to allow venting during charging, discharging and other atmospheric pressure changes.

Currently, there are two lead-acid systems used, the small sealed lead-acid (SLA) and the larger valve-regulated lead-acid (VRLA).
The newer type of sealed lead-acid batteries are the Absorbed Glass Mat batteries (AGM) that are maintenance free and the plates are mounted in such a way that they can withstand extensive vibration and shock. The hydrogen emission from cars using these batteries is less than 4% and self-discharge is extremely low at 1-3% per month. This gives them long storage before the need to recharge. These batteries are more expensive than the flooded lead-acid batteries (liquid electrolyte), but because of their durability, they are the preferred version for high performance cars rather than the flooded variety.
One of the best things about lead-acid batteries is their self-discharge, which is one of the best on rechargeable batteries at about 40% per year, in comparison with nickel-cadmium that self-discharges in three months.
In conclusion, lead-acid batteries are a perfect choice for cars as they are inexpensive, reliable and provide dependable service, durable when used appropriately, and they have the lowest self-discharge rate among rechargeable batteries.


Wednesday, September 29, 2010

Electricity Storage-Pumped and Elated Hydro, Superconducting Magnetic, Fuel Cell Supercapacitor, Compressed Air, Flywheel and Ammonia Power Storage

Modern Technologies and Trends to Store Electricity and Energy in Huge Quantities to meet Peak Hour demands in the Grid

Author-Engineer4u Writer4u Friend4u


Energy storage in huge quantity remained great challenge for Scientist since long. There are many invention and innovation but still challenge is present. Many Scientist around the Globe are working to find solution. Many Scientists are giving us innovative solution and important lead which may be utilized for our future.


Lead-Acid Battery and Capacitors are well known devices which are used for storage of electricity but these devices can’t store electricity in huge quantity.


Superconducting magnetic energy storage, Hybrid capacitor-Battery Storage device, Super Capacitors, Fuel cells, Synthetic Zeolite to store Solar energy, Ammonia Energy Storage, Flywheel Energy Storage and Compressed Air Storage Power Plants are said to be at developmental stage and Scientist are working very hard to find feasible solution. We hope these innovations will give us promising results and solve our problems in near future but till then we have a more viable solution for Storage of Electricity in huge quantity which is Pumped Storage Hydro Power Plant.


Superconducting Magnetic Energy Storage

Superconducting Magnetic Energy Storage (SMES) systems store energy in the magnetic field created by the flow of direct current in a superconducting coil.


compressed air energy storage

In compressed air energy storage, off-peak power is taken from the grid and is used to pump air into a sealed underground cavern to a high pressure. Compressed air energy storage technology involves taking excess energy from a power plant or renewable energy, using it to run air Compressor to store energy.



Supercapacitors and Ultracapacitors

Supercapacitors and Ultracapacitors are the new super battery for energy storage. supercapacitors will supply power to the system when there are surges.


synthetic zeolites have shown positive results for solar energy storage.


Fuel Cell

A fuel cell is an electrochemical cell that converts a source fuel into an electric current.



Pumped storage Hydro power Plant

For storing energy in bulk quantity Pumped storage Hydro power Plant may be viable solution. In pumped storage hydro power plant energy is stored by lifting water to upper pond during off-peak period. Stored water’s potential energy is utilized
during peak hour.


Generally electricity may be purchased during off-peak period for almost negligible price and same may be sold at very high prices at peak load hours. Installing such pump storage hydro power plant may solve many problems such as voltage and frequency control. Such pump storage hydro power plant provides stability to our Grid. Installing Pumped storage Hydro Power Plant may be profitable venture and same may prove as great business ideas for generating profits.



Reversible Pump -Turbine and Motor- Generator set is being used for that purpose and its efficiency is more than 70%.



Sea, Lake and River Water may be stored at height by Pumps in Reservoirs and same may be utilized for generation of electricity by reversible pump-turbine set at Peak load. Even used mines filled with water may be used for Installing Small Pumped storage Hydro Power Plants.



High Initial cost and long erection period for Pumped Storage Hydro Power Plant are limiting factor but benefits of Pump Hydro Power Plants are tremendous hence same may be termed as only viable or feasible solution for storage of energy at present which not only gives us huge quantity of electricity at peak hour but also it is useful for management of our Grid.


Pumped Storage Power Plants may be backbone for intermittent Renewable such as Wind Solar Power. Energy produced by renewable may be utilized to pump water to higher Reservoir which may be utilized during demands.


Elated Hydro Power Plant

Capacity of existing Hydro power Plant may be increased to meet peak hour demand is also very much cost effective Idea. Hydro Power Station which is running on base load may be elated by addiction of capacity. Losses due to pumping may be avoided by elated Hydro Power Plant.



Readers are requested to provide Promising and Feasible Leads on which our Scientist may work to create Miracle. Finding solution for storing electricity or energy is need of the hour to utilized intermittent Renewable Power such as Solar or Wind Energy which is clean energy.

http://electricitystorage.blogspot.com/


Electricity or Energy Storage Research and Innovation Mission

Pumped Storage Hydro Power Plant, Elated Hydro Power, Superconducting magnetic energy storage, Hybrid capacitor-Battery Storage device, Super Capacitors, Fuel cells, Synthetic Zeolite to store Solar energy and Compressed Air Storage Power Plants

Wednesday, September 8, 2010

How to deal Emergencies in Thermal Power Plant? Introduction, Facts and solution of Most critical problems of Thermal Power Plant

Introduction, Facts, Problem Solution and Tackle Emergencies of Thermal Power Plant


Boiler is used for steam generation.


Ball Mill or Bowl mills are used for pulverisation of coal in powder form for efficient firing in boiler.


Raw Coal Feeders are used to supply coal to ball mills in controlled quantity.


Primary Air Fan is used to transport and preheat pulverised coal to burners.


Induced Draught Fan is used to exhaust flue gases to Chimney and create vacuum in Furnace.



Electrostatic Precipitators are used to separate ash particles from flue gases to control pollution. Here collecting electrode, emitting electrode and rapping mechanism used to dislodge fly ash particle.


FD Fan used to provide air to boiler for help in firing which is called secondary air.


Steam produced in boiler is further superheated in Super heaters. There are lot super heaters such as platen, pendent, convection and final super heaters.


Boiler drum used for separation of steam from water and storage. Nowadays drum less once through boiler also used which operates at super critical temperature and Pressure.


Boiler circulation pump used for forced circulation of water in water wall because at high pressure natural circulation is not possible.


Soot Blowers used to remove soot from water wall, Super heater, Re heaters and Air Heaters by injecting steam into heating surfaces.


Ash slurry pumps are used to flush ash with water.


Boiler Feed Pump used to provide water to boiler Drum.


De aerator used to separate dissolved air from Feed water.


In Turbine heat energy of steam is converted into mechanical energy.


ESV which is called emergency stop valve used to stop supply of steam to turbine when unit trips.


Re heaters used to reheat steam exhausted from HP turbine. After reheating up to 535 degree Centigrade same steam is utilised in Intermediate Pressure Turbine.


Barring gear or shaft turning gear is used to rotate turbine rotor at 3.15 rpm when turbine is not running to check bending of rotor due to its own weight.


LP Heaters and HP Heaters are used to heat condensate and feed water supplied to boiler to increase efficiency by steam bled from turbine extraction.


Economiser is used to heat feed water by flue gages to increase efficiency. Heat of waste flue gas is utilised here.


Air Heaters uses heat of waste flue gases to preheat primary and secondary air. There are two types of air heaters tubular and rotary.


Condenser used to condense steam exhausted from turbine.


Condensate Pump are used to supply water to De aerator from condenser Hot well.


CW Pump used to cool steam exhausted from turbine into condensers.


Raw Water is circulated by cw pump into condenser tube hence leakage from condenser tubes must be checked to avoid mixing of raw water into Hot well.


Turbo generator converts mechanical energy into electrical energy.


H2 Gas used in generators used for cooling of generators.


Seal Oil system used to seal hydrogen gas from escape from generator.


Stator Water Cooling system provides demineralised water into hollow stator conductor of generator for its cooling.


Generating Tans former steps up voltage for transmission.


Water Treatment Plant is used to produce demineralised water for steam generation. Cation anion and degasifier tower used to separate mineral and gases from water.PAC or alum used to separate mud and silica from water. Here minerals removed from water and pH value is maintained near 7 and silica value must less than 0.02 ppm


Coal Handling Plant supplies Coal to Boiler. Merry go round system or wagon tippler used to unload coal into hoppers. Coal is crushed in crusher to crush it in 25mm size. Magnetic separators used to separate metallic particles from coal.


ABCB, SF6, OCB, MOCB and VCB are circuit breakers used to make or break electricity contact at load.


Isolators are used to make or break contact at no loads.

ABT

ABT is availability based tariff and frequency based pricing system to maintain Grid discipline.


Purging is done to clean furnace from combustible gases by running ID Fan and FD Fan at least 30% load for 5 minutes to avoid furnace explosion.


Furnace explosion may be checked by timely purging and adjusting firing properly using right quantity of primary and secondary air and timely oil support and avoiding leakage of fuel oil in boiler. Furnace must be purged properly again if flame is not established during light up of boiler.


Flame scanners used to sense flame in boiler to detect flame failure to avoid boiler furnace explosion.


FSSS is furnace safeguards supervisory system to safeguard boiler.

How to avoid Clinker Formation in Boiler?
Clinker Formation in Boiler of Thermal Power Station is due to high Ash Content which have low fusion temperature below 1470 degree Centigrade and Minerals present in it. Due to poor Quality of Coal ash got fused and mineral content stick into Water Wall which is very difficult to remove often requires removal by pneumatic machines. This Clinker deposition may be stopped to some extent if sufficient water is sprayed into hopper and regular poking and using good quality of coal. Ash fusion temperature must be above 1470 degree Centigrade and soot blowing regularly at load by injecting steam by wall blowers. Over firing is also responsible hence firing must be properly adjusted by proper balance of primary and secondary air in boiler.



Accumulation of clinker may be checked if poking of hoppers done regularly and any negligence may start process of clinker deposition. If clinker is not removed immediately then same may choke hopper and often workers got burnt due to sudden fall of hot water which accumulated in hopper.


Once clinker formed into hopper than outage of unit is evident otherwise clinker may deposit in huge quantity which will be very difficult to remove because minerals content present in coal fused with ash deposit into water wall. Such hard Lumps of Clinkers requires pneumatic hammering which takes very much time resulting in forced closure of unit for weeks.



Although cause of clinker formation is poor coal quality and high mineral content in coal but accumulation in Water Wall is result of negligence by Workers and Engineers who do not poke hopper regularly and spray insufficient amount of water into hopper which may not flush fused slag to channels. Outage of clinker grinder and soot blower is also matter of concern may be termed as negligence.



Hence it is advised never blame to low coal quality, low GCV, low ash fusion temperature and high mineral content in coal. Instead of blaming to above factors try regular poking and provide sufficient water in hopper. Clinker Grinders must be made operational. Soot blowing must be done regularly by injecting steam. In India coal supplied to power plants is mostly of low quality which has high ash content so precaution is best solution here to avoid deposition and formation of clinkers in Boiler.


Precaution may stop clinker deposition and formation so remain vigilant.
Boiler Tube Leak Detection by Acoustic Monitoring Instruments

Acoustic Instruments may be used to detect early boiler tube leak to avoid secondary damage to pressure parts. Boiler acoustic tube leak detection system must be used as it prevents damage to costly boiler parts and it is very much cost effective. An increase in boiler availability of just one day will more than cover the cost of a leak detection system.




Traditional leak detection system such hearing hissing sound by ear or monitoring feed water flow or furnace vacuum is not much reliable because it can not detect small leak so damage to vital costly equipment of boiler may not be avoided. Writer noticed many instances where thermal power plants boiler allowed to run for long time due to confusion which caused permanent damage to many boiler tubes, refractory and boiler structures. Hence importance of acoustic monitoring leak detection systems sincerely felt.




Acoustic leak detection sensors detect high frequency emissions from site of leak and Sensitive piezoelectric sensors mounted to the structure transform these acoustic waves to electronic voltage signals, which are amplified, filtered, and processed to determine energy content.




Early detection by acoustic monitoring instruments results in substantial reduction of repair times and costs with a consequent increase in plant availability and profits. The early detection of a boiler tube leak will give financial savings which will easily exceed the initial capital cost of the detection system even at the very first event.




http://www.acousticmonitoring.com/


Acoustic monitoring international


p (330)305-1422f (330)494-9822-16707 harbour drive n.w cantou Ohio 447


http://www.proconeng.com/mainfiles/boilerleak.html



procon engineering


http://www.triple5industries.com/


http://www.steamleak.com/


How to Run Thermal Power Plant Units Efficiently?

How to run units efficiently and safely is big question today? Thermal Power Plant Units require great care during operation. Only highly trained Employees and Engineers may handle effectively. Only Quality Training Programmes for Engineers and Operators may ensure efficient Running. Greatest Importance must be given to such Training Programmes. Frequent trippings, damage of auxiliaries and Accidents are seen if Engineers and Employees are not properly trained. Engineers must know important facts and Operational Precaution for efficient operation of Units which are described below.
Coal is received from mines by Merry Go Round System. Old Power Houses uses the Wagon Tripler which turns Wagon to unload it. Coal is crushed up to size of 25 mm and Magnetic particles are separated. If Coal is not properly crushed and Iron pieces not separated then Pulverisers and Raw Coal Feeders will face severe problems. Chain of Raw Coal Feeder may damage due to metallic parts present in Coal. Big Size Coal may affect grinding capacity of our Pulverisers.

Raw Coal Feeders are used to provide controlled quantity of Coal to Pulverisers. Ball Mill or Bowl Mill is being used to grind coal in powder form for efficiently burning Coal.

Primary Air Fan provides air for transportation of Coal and its drying. Forced Draught Fan provides Secondary Air help burning coal. Important points which must be remember that Ratio of Primary and Secondary must be proper. Quantity of Primary Air, Secondary Air and Pulverised Coal must be properly adjusted and firing must be checked properly by flame scanners so that they may not be unburnt coal.

Air from Feed Water is separated by De aerator. Hydrazine is dosed here so that oxygen is removed from feed water. Phosphate dosing is done in Boiler Drum to separate Silica particles from feed water. Dosing of Phosphate and Hydrazine must be properly monitored. Sample of water must be timely getting checked from Lab so that deposition of silica in Boiler Tubes and Turbine Blades may be avoided. Continuous Blow Down valve is generally opened up to 10% to 30% as per sample reports from water chemistry lab.

At the start of boiler ignitors or oil rows if the flame is not established then we must relight boiler after purging. Boiler Furnace explosion may be avoided by timely purging and stoppage of leakage of fuel oil in
furnace. Purging is done before every light up of boiler by starting Induced Draft Fan and Forced Draft
Fan for five minute and maintains 30% air flow for five minutes so that UN burnt fuel and gases present in
boiler furnace may escape.

At low load always take fuel oil support to avoid flame failure.

Soot blowing which done to dislodge soot from boiler tubes must be regularly done by injecting steam at
sufficient pressure and temperature as per manufacturer's guidelines and instructions.

Poking of ash hoppers must be continuously monitored so that hoppers may not choke and further
deposition of clinkers takes place. Clinker grinders must be made operational.

L P Drain which are provided at boiler zero meter for draining water if salt concentration and silica value
increases must be operated under strict guidance and monitoring. L P Drain valve must be opened
partially, one by one for less than one minute otherwise water wall may damage due to stoppage of natural circulation. It is best practice to operate L P Drain at the time of light up of boiler when pressure and
temperature is relatively low.

Isolators must be opened or closed at no Loads and Circuit Breakers may be opened or closed at Load.

Stator water cooling system is provided for cooling of Generator Stator Conductors where Demineralised water is circulated in hollow conductors. Quality of Demineralised water must be monitored.

Power Plant Auxiliaries such as I D Fan, F D Fan, and PA Fan must be started at no load because at the time of start of motor it takes nearly 14 times more current. Position of Discharge and Suction Dampers must be properly checked.

For starting Boiler Feed Pump we must ensure that suction valve is opened and discharge valve is closed and recirculation valve must be opened.

Interlock and Protection must be timely checked to know its functioning.

At the instant of tripping of unit we must open Main breaker first and after Main breaker is tripped and current in all three phases shows zero then we must open field breaker of generator for its safety.
D C Seal oil Pump, D C Lube oil Pump, D C Fire Pump must be started daily to check its functioning.

Barring Gear or Shaft Turning Gear must be immediately engaged when turbine rotor speed reaches to zero to avoid its bending.

At the time of Boiler Tube Leakage we must immediately trip the unit to avoid secondary damage. Feed flow quantity, De aerator level, Furnace Vacuum must be monitored regularly. Hissing sound may be observed from site in case of tube leakage. Acoustic Monitoring Instruments may also be used to detect small Boiler Tube Leakage up to size of 2.5 mm with its correct location. This system may detect leakage at the moment it starts.

Operation of Modern Thermal Power Plant requires great attention and Precaution for its safe and efficient running although many advanced protection, auto and burner management system which are controlled by latest software and computer are provided. Engineers engaged in operation should remain vigilant, understand the procedures to control emergencies and prepare for many more unexpected circumstances.



https://sites.google.com/site/thermaltraining/


how a coal power station works?

Saturday, July 31, 2010

Acoustic Monitoring Instruments for Boiler tube leakage detection in Thermal Power Plants

Acoustic Instruments may be used to detect early boiler tube leak to avoid secondary damage to pressure parts. Boiler acoustic tube leak detection system must be used as it prevents damage to costly boiler parts and it is very much cost effective. An increase in boiler availability of just one day will more than cover the cost of a leak detection system.




Traditional leak detection system such hearing hissing sound by ear or monitoring feed water flow or furnace vacuum is not much reliable because it can not detect small leak so damage to vital costly equipment of boiler may not be avoided. Writer noticed many instances where thermal power plants boiler allowed to run for long time due to confusion which caused permanent damage to many boiler tubes, refractory and boiler structures. Hence importance of acoustic monitoring leak detection systems sincerely felt.




Acoustic leak detection sensors detect high frequency emissions from site of leak and Sensitive piezoelectric sensors mounted to the structure transform these acoustic waves to electronic voltage signals, which are amplified, filtered, and processed to determine energy content.




Early detection by acoustic monitoring instruments results in substantial reduction of repair times and costs with a consequent increase in plant availability and profits. The early detection of a bolier tube leak will give financial savings which will easily exceed the initial capital cost of the detection system even at the very first event.




Finally, Acoustic monitoring instruments must be installed in boilers of thermal power plants. For more details go to


http://www.acousticmonitoring.com/


Acoustic monitoring international


p (330)305-1422f(330)494-9822-16707 harbour drive n.w cantou ohio 447


http://www.proconeng.com/mainfiles/boilerleak.html


procon engineering


http://www.triple5industries.com/


http://www.steamleak.com/

Tuesday, July 13, 2010

Superheater Waterwall Economiser Tube Leakage may be detected by Acoustic Instruments to avoid secondary damage to Boiler

Detect Boiler Tube Leakage Early to avoid secondary Damage. Super heater Water Wall Economiser Tube Leakage may be detected by Acoustic Instruments to avoid secondary damage.BTL may damage boiler tubes, refractory, structure beams and choke Air heater tubes so it must be watched carefully.



There must be constant vigil on possibility of Boiler Tube Leakage because small negligence may result into heavy leakage to pressure parts of Boiler, its refractory’s and even to its Structure Beams etc. We must constantly watch furnace vacuum which must be maintained -10 to -20 mmwl. If furnace vacuum is disturbed then we must physically inspect boiler for hissing sound of leakage of steam. Nowadays some Acoustic Instruments also available which may detect steam leakage from boiler tube. Feed water flow is another parameter which must be watched carefully to judge boiler tube leakage. Any increase of feed water flow and decreasing of de aerator level must be seriously examined.




There are several type of boiler tube leakage such as Super Heater Leakage, Water Wall Leakage and Economiser Tube Leakage, all type of boiler tube leakage are seriously dangerous for Boiler. In some cases I have seen that Economiser leakage not taken seriously and unit allowed running for some time which resulted into chocking of Air Heater Tube which resulted into pressurisation on Boiler Furnace.

Sunday, July 11, 2010

Boiler Turbogenerator GT ESP ABT FSS Deaerator Scanners Soot blowers Air heaters Economisers Superheaters Reheaters ID FD PA Fan BFP LPH HPH CW Pump

Introduction and some facts about large thermal power station for efficient operation.


Boiler is used for steam generation.


Ball Mill or Bowl mills are used for pulverisation of coal in powder form for efficient firing in boiler.


Raw Coal Feeders are used to supply coal to ball mills in controlled quantity.


PA Fan is used to transport and preheat pulverised coal to burners.


ID Fan is used to exhaust flue gases to chimney and create vacuum in Furnace.


Electrostatic Precipitators are used to separate ash particles from flue gases to control pollution. Here collecting electrode emitting electrode and rapping mechanism used.


FD Fan used to provide air to boiler for help in firing.


Steam produced in boiler is further superheated in Super heaters. There are lot super heaters such as platen, pendent, convection and final super heaters.


Boiler drum used for separation of steam from water and storage. Nowadays drum less once through boiler also used which operates at super critical temperature and Pressure.


Boiler circulation pump used for forced circulation of water in water wall because at high pressure natural circulation is not possible.


Soot Blowers used to remove soot from water wall, Super heater, Re heaters and Air Heaters by injecting steam into heating surfaces.


Ash slurry pumps are used to flush ash with water.


Boiler Feed Pump used to provide water to boiler Drum.


Deaerator used to separate dissolved air from Feed water.


In Turbine heat energy of steam is converted into mechanical energy.


ESV which is called emergency stop valve used to stop supply of steam to turbine when unit trips.


Re heaters used to reheat steam exhausted from HP turbine. After reheating up to 535 degree centigrade same steam is utilised in Intermediate Pressure Turbine.


Barring gear or shaft turning gear is used to rotate turbine rotor at 3.15 rpm when turbine is not running to check bending of rotor due to its own weight.


LP Heaters and HP Heaters are used to heat condensate and feed water supplied to boiler to increase efficiency by steam bled from turbine extraction.


Economiser is used to heat feed water by flue gages to increase efficiency. Heat of waste flue gas is utilised here.


Air Heaters uses heat of waste flue gases to preheat primary and secondary air. There are two types of air heaters tubular and rotary.


Condenser used to condense steam exhausted from turbine.


Condensate Pump are used to supply water to De aerator from condenser Hot well.


CW Pump used to cool steam exhausted from turbine into condensers.


Raw Water is circulated by cw pump into condenser tube hence leakage from condenser tubes must be checked to avoid mixing of raw water into Hot well.


Turbo generator converts mechanical energy into electrical energy.


H2 Gas used in generators used for cooling of generators.


Seal Oil system used to seal hydrogen gas from escape from generator.


Stator Water Cooling system provides demineralised water into hollow stator conductor of generator for its cooling.


Generating Transformer step up voltage for transmission.


Water Treatment Plant is used to produce demineralised water for steam generation. Cation anion and degasifier’s tower used to separate mineral and gases from water.PAC or alum used to separate mud and silica from water. Here minerals removed from water and ph value is maintained near 7 and silica value must less them 0.02 ppm


Coal Handling Plant supplies Coal to Boiler. Merry go round system or wagon tippler used to unload coal into hoppers. Coal is crushed in crusher to crush it in 25mm size. Magnetic separators used to separate metallic particles from coal.


ABCB, SF6, OCB, MOCB and VCB are circuit breakers used to make or break electricity contact at load.


Isolators are used to make or break contact at no loads.


ABT is availability based tariff system to maintain grid discipline.


Purging is done to clean furnace from combustible gases by running ID Fan and FD Fan at least 30% load for 5 minutes to avoid furnace explosion.


Furnace explosion may be checked by timely purging and adjusting firing properly using right quantity primary and secondary air and timely oil support and avoiding leakage of fuel oil in boiler. Furnace must be purged properly again if flame is not established during light up of boiler.


Flame scanners used to sense flame in boiler to detect flame failure to avoid boiler furnace explosion.


FSSS is furnace safeguards supervisory system to safeguard boiler.


Clinker formation which caused by more ash content having low fusion temperature and mineral in poor quality coal may be checked by proper poking and using more water for flushing and use of clinker grinder and regular soot blowing. Over firing which is also cause of clinker formation may be avoided by proper primary and secondary air ratio.


Acoustic Instruments used to detect early boiler tube leakage to avoid secondary damage to pressure parts, Refractory and structures of Boiler. Boiler must be immediately shut down in case of Boiler tube Leakage.

http://tpp-4u.blogspot.com/

Friday, July 9, 2010

Avoid Clinker Formation in Boiler using good quality coal, poking, soot blowing, flushing slag by sufficient water from hopper

Clinker Formation in Boiler of Thermal Power Station is due to high Ash Content which have low fusion temperature below 1500 degree centigrade and Minerals present in it. Due to poor Quality of Coal ash got fused and mineral content stick into Water Wall which is very difficult to remove often requires removal by pneumatic machines. This Clinker deposition may be stopped to some extent if sufficient water is sprayed into hopper and regular poking to remove deposition and using good quality of coal. Ash fusion temperature must be above 1500 degree centigrade and soot blowing regularly at load by injecting steam by wall blowers. Over firing is also responsible hence firing must be properly adjusted by proper balance of primary and secondary air in boiler.



Accumulation of clinker may be checked if poking of hoppers done regularly and any negligence may start process of clinker deposition. If clinker is not removed immediately then same may choke hopper and often workers got burnt due to sudden fall of hot water which accumulated in hopper.


Once clinker formed into hopper than outage of unit is evident otherwise clinker may deposit in huge quantity which will be very difficult to remove because minerals content present in coal fused with ash deposit into water wall. Such hard Lumps of Clinkers requires pneumatic hammering which takes very much time resulting in forced closure of unit for weeks.



Although cause of clinker formation is poor coal quality and high mineral content in coal but accumulation in Water Wall is result of negligence by Workers and Engineers who do not poke hopper regularly and spray insufficient amount of water into hopper which may not flush fused slag to channels. Outage of clinker grinder and soot blower is also matter of concern may be termed as negligence.



Hence it is advised never blame to low coal quality, low GCV, low ash fusion temperature and high mineral content in coal. Instead of blaming to above factors try regular poking and provide sufficient water in hopper. Clinker Grinders must be made operational. Soot blowing must be done regularly by injecting steam. In India coal supplied to power plants is mostly of low quality which has high ash content so precaution is best solution here to avoid deposition and formation of clinkers in Boiler.


Precaution may stop clinker deposition and formation so remain vigilant.

Electrostatic Precipitators for Pollution control

Electrostatic Precipitators for Pollution control
ESP