Affinity laws are applied in centrifugal loads. Centrifugal loads such as pump, compressor, fan, hydraulic system and the like. This is a well settled scientific law that was discovered long time ago but not widely used until advent of
The increase of global energy consumption due to increasing demands from all sectors of our society is very alarming. One major factor that affects this problem is the increasing rate of carbon emissions coming from the burning of fossil fuels particularly petroleum, coal and gas. However no matter what are our reasons maybe we cannot deny the fact that we cannot live in todays world without doing the same. From the all forms of vehicles that we used everyday for transportation, appliances that we are using to give us aide in doing house chores, and to the industrial machinery used for producing products with high global demands. These are but some of our daily activities that we cannot live without. According to the EIA (Energy Information Administration) based on Washington DC in the year 2008 the total world energy consumption is 143,000 TeraWatthours. Around 81% of these were produced using fossil fuels! In due time scientist predicted the decline of vast reserves of fossil fuels. Even if fossil fuels cannot be depleted the drawback is the accumulation of carbon emissions in the atmosphere which is the responsible for the climate change.
A Product of Human Knowledge
Human knowledge brought this present civilization by which the dependence of modern technology is at par. This dependence is supposed give us convenience, however what we see is an irony since the one that gives us convenience is the same thing that could lead us into chaos. Scientists predicted that the growing rate of carbon emissions will increase the global temperature that could vehemently affect the global climate. The melting of glaciers is one of the evidences that our global temperature is indeed increasing. One of the effects of this is the rapid rate of rising of sea water level that causes floods in some areas and pollutes groundwater supply with sea water making it not suitable for domestic purposes. Other effects not to mention is far or equally worst than the latter such as hurricanes and famine. What are happening today reminds us that we have responsibilities to at least mitigate the worst effect of global warming. Modernization is inevitable so all we have to do is a win-win solution.We know that human knowledge is involve in this dilemna therefore human knowledge can also be use to mitigate it. But it is not a question of "what" but it is a question of attitude and commitment, that is how people can be cooperative can be in order to achieve this goal--- mitigate the effect of global warming.
Currently with the advancement of research and technology we already have invented products and enacted state legislations that could possibly be the solution solve for the problem. Led Technology
The use LED technology could really help to reduce our energy consumption. The lights in our home, street lights, cars and traffic lights can help to reduce energy consumption. Compare to the conventional lighting with the same capacity LED is 60%-80% more efficient and could last long by 10 to 50 times compare to others. If we analyze deeply buying LED lights while higher in cost but surely will compensate the maintenance and replacement cost compare to the conventional one. But be sure to buy the original LED lights from reputable manufacturers.
In the same vein LED technology is not only limited to lighting equipment but it also have other major products such as LED TV and LED monitor. According to study LED TV and monitor can cut our electricity consumption for as high as 40% compare to LCD TV. However because this is a new breed of technology the setback is a higher price but with the market competition sooner or later prices of this stuff will become affordable.
In transportation the use electric vehicles and hybrid automobile can help to reduce carbon emissions in significant percentage if used by the majority. For urban places where transportation vehicles need not high torque and high speed the use of electric vehicle is suitable. Good example for this is in the Philippines where e-jeepney are used for public transportation.This e-jeepney is using a12-volts battery for power and therefore does not create carbon emissions.
Automation Systems
The help of modern automation for building management and industrial processes help to achieve an effective energy savings strategies. For building designers they can use advance BMS (Building Management systems) technology by focusing on the automation of building lightings, ventilation, heating and airconditiong systems. This features automatic shut-off to the active state of several equipments such as lighting, air conditioning and heater while the office or hall is not in use. In industrial plants the use of SCADA (Supervisory Control And Data Acquisition) features energy management system that automatically control the optimum use of energy in the process thus wastage can be eliminated. Manufacturers of these equipments is certain of the the return of investment if these equipments will be use. Therefore industrial plants that uses this technology does not only helped in saving the environment but also have augmented the profit margin of the company.
State Legislations
Not only for consuming public but also to the people who are engaged in the the policy and control of the supply of energy particularly the government and the investors. These sectors of the society should develop the untapped renewable energy. State legislators must enact laws how to effectively impose the development of the said renewable energy such as giving tax incentives for those corporations who are interested in investing in renewable energy in their area. In addition the strict imposition of the regulation of equipment manufacturers to comply with the highly efficient products. As early as 1992 the United States have already enacted the Energy Policy Act of 1992 as amended by the Energy Independence and Security Act of 2007 to enhance the state energy management policies. Also in the Philippines the Republic Act 8749 also known as the Philippine Clean Air Act of 1999 was enacted to reduced air pollution. Furthermore the state must also segregate certain areas to be used as carbon sink where trees are planted to offset the harmful carbon emissions. However these policies must be strictly imposed and should not be remain as a paper in the repository of laws.
Energy Independence and Security Act of 2007
Federal Energy Management Program: Energy Independence & Security Act
The Energy Independence and Security Act of 2007 (EISA 2007) established energy management goals and requirements while also amending portions of the National Energy Conservation Policy Act (NECPA). It was signed into law on December 19, 2007.
These things are not just a duty of a single entity but a cooperation from all sectors of the society. May the higher cost of these things shall not hinder the implementation and jeopardize our goals. This cannot be achieve overnight but rather it is a long process of commitment and dedication. We may restructure the economy to achieve this goal and corporations may sacrifice some profits but if for the benefit of all mankind we have no choice but to undertake the win-win solution or else we will resort into a win-loss solution where we are the losers and our civilization may vanished.
Electric motors are frequently used by industrial plants for several purposes. Without this equipment mass production of goods with global demands are very hard to achieve. The energy that causes this equipment to put into motion is the electrical energy. According to study in 2008 alone more than half of electricity of the world are produced coming from power plants that are feed by burning fossil fuels like oil, gas and coal. Burning fossil fuels produced carbon emission that are harmful to our environment. Global warming is the principal effect of excessive carbon dioxide in the atmosphere. Any methods that could reduce energy consumption could also directly reduce the excessive carbon dioxide in the atmosphere.
The variable frequency drive (VFD)
Variable frequency drive is an electrical device that can be used to reduce speed of an induction motor from rated speed down to zero speed. This varies according to sizes ranging from a fractional horsepower rating up to 10,000 horsepower and a rated voltage of 110 volts up to 24 kilovolts. Since this equipment is relatively expensive therefore a well trained engineers in this field should be consulted in selecting the type of VFD to be used in a particular installation. Improper selection of VFD may result into undesirable result and could damage other equipments in the vicinity.
How VFD reduce electric consumption
Variable frequency reduce electric consumption in relation to the type of application by which the electric motor is used. The application that is referred here is the centrifugal loads such as fans and pumps. The reduction of speed of motors used in centrifugal applications has corresponding power reduction as described in the relation that the power is directly proportional to the cube of the shaft speed. This scientific law is commonly known as law of affinity. From the given formula its shows that a reduction of 80% speed will result into 50% reduction in power.
Typical applications
Air Blast Freezer
Fan is used by air blast freezer in order to circulate the air uniformly inside the cold room. However in some applications there are instances where temperature lesser than -35 degrees celsius is no longer necessary. Thus continuous full operation of fans is no longer necessary however it is impractical to shut-off this fan because the product temperature inside will surely rise up again. In this situation some operators have no choice but to choose to remain the full operation of fan even the excessive low temperature is no longer required.
When the temperature of the cold room reached its desired level we can used VFD in order to slow down the speed of the fan just to maintain the desired temperature. Take note that 80% speed reduction will result into 50% energy reduction.
Drying Bins
Like in air blast freezer fans are also used in drying bins to induced hot air to dry the product inside. Products such as corn and coconut when placed in the drying bin have different moisture content at the start of the drying process. Sometime the amount of product to be dried is relatively lesser compare to the size of the drying vessel. Therefore there are really times that force evacuation of excessive hot air is applied in order not to damage the product. Bleeding method to evacuate this excess hot air is applied by installation of a valve besides the drying bin that controls the amount of air to be evacuated. We must know that every time that bleeding takes place it constitutes waste of energy.
With the use of VFD we can make speed reduction in the motor that drives the fan in order to slow down the supply of hot air. As a result only required volume of hot air will be induced and the bleeding process will be eliminated. Simply by this way energy savings is achieve.
Booster Pump
Booster pump is applied to water system where there are identified place that normal system pressure is low and needs to be increased. The pressure at this point is variable depending upon the number of the opened valve running through this pump. Many open valves would result into a lower pressure and a higher pressure to the contrary. To remedy the variability of the pressure, engineers install a relief valve coupled with pipe that returns to the water tank. Meaning to say that if there are only few valves open that would result into a higher pressure the relief valve will release and the excess water will return to the tank so that the piping will not be damage as a result of the over pressure. And if there are no open valves then it means that the water are just circulating all over the pipe while pump are continuously running. This operation is necessary in this design in order to provide water whenever at any time there is one valve that will suddenly open. Every time there are even small amount of water that flows back to the tank manifests energy loss.
If we will integrate the VFD in the design of water system as described in the example, all we have to do is to install it together with a pressure transducer forming a close loop. This transducer will provide feedback signal to the VFD that commands the speed of the motor.
Assures return of investment
The above mentioned applications are just few examples of using the variable frequency drive in using as a tool for energy savings. Other applications varies on how the engineer could come up into a design that fits for any existing system aiming to improve the efficiency of the process. There are companies who have testified that the use of VFD assures return of investment in which top management is concern in particular. You can save energy, enhance your profitability and most of all you help to protect the environment in making it all the time healthy.
