schneider innovation challenge 2010

8/6/2019 Schneider Innovation Challenge 2010

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Innovation Challenge 2010

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Title

Power Optimization in the Building

College

Thiagarajar College of Engineering, Madurai-15

Participant Name Engg. Department +Semester

Address Contact number

ASHOK PElectrical andElectronics,

Vth semester.

ROOM NO: PG 12,TCEMENS HOSTEL,

THIRUPARANGUNDRAM,MADURAI 09.

+919003445493

RAJALAKSHMI KElectrical andElectronics,

Vth semester.

10\1, SRI SABARI ILLAM,JEYRAJ NAGAR,OPP TO FATIMA

COLLEGE,MADURAI 18

+919488010394

SINDHU PRIYA O MElectrical andElectronics,

Vth semester.

12/31,SBOA 2nd COLONY,BY PASS ROAD,

MADURAI.+919789513539

SURESH KUMAR R

Electrical and

Electronics,Vth semester.

ROOM NO: C-23,TCE

MENS HOSTEL,THIRUPARANGUNDRAM,

MADURAI 09.

+919003576190


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Contents

1. Abstract

2. Concept and Innovation details

3. Automatic Monitor Control

4. Energy Efficient Printer

5. Energy Efficient Mobile Charger

6. Optimized Compressor using VFD Technique

7. An Innovative Approach towards Optimization

8. Net power Savings

9. Future work possible

10. References


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Abstract:Make the most of your energy. This paper mainly aims at modeling an energy

efficient building by optimizing the energy consumption. The major power consuming loadsin the building are Air Conditioner, Computer, printer, servers and lift. We have mainlyconcentrated to reduce power consumption in these areas. We have also suggestedinnovative ideas to bring down the power consumption by phantom loads.

Concept and innovation details:

Assumptions:1. There are 500 computers in the building2. One monitor consumes 60 watts in ON mode.3. A printer dissipates 11 watts during stand by mode.

4. Office is running for 24 hours.5. In ac, compressor attains maximum efficiency at 28 degrees.6. A cell phone charger consumes 0.6 watts during stand by mode.

AUTOMATIC MONITOR CONTROL

Monitor forms an essential part of the computer system. It consumes nearly 35-40 % of power, about 60W, while in use. When in stand by mode it consumes about 6.5 W.In order to reduce this wastage of power for long duration we suggest the device-

Problem statement:

Consider a working environment, a personal computer forms an essentialpart of it. This pc is usually kept in ON condition even if its user is busy for a short durationwith another job. During such a situation the power consumed by the computer and itsperipherals either in running or in standby mode can be saved. This leads to huge savingsin the monthly bills. The basic idea is to switch OFF the monitor when not in use. In order todo this there may be two different possibilities-

(1) Usage of wireless Technology(2) Usage of wired control.

The wireless technology includes a transmitter (which is to be placed in the chair to which

the employee is seated) and a receiver circuitry (which is to be placed on the CPU) whichmay fail to produce the expected results in situations like-

(a) Changing the direction of the transmitter( chair).(b) Presence of an obstacle between transmitter and receiver.

Considering the disadvantages of the wireless system we adopt the wired controlmechanism.


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Working:

The automatic monitor control system consists of a wired connection between the chair inwhich the employee is seated and the processor of the computer. This circuit includes

Limit switches

Timer circuit

Monitor control circuitry.

Limit switches:

These switches are commonly employed as input devices to indicate thepresence or absence of a particular condition in a system or process that is being

controlled. It is a mechanically actuated switch. This is placed in the chair in which theperson is seated. This switch gets activated by the mechanical action of getting up andsitting down. The switch is designed in such away that when the employee is seated it is innormally open (NO) condition. When the person gets up the limit switch comes to normallyclosed (NC) condition, thereby, activating the timer circuit.

Monitor Status(A)

Switch Position(B)

Monitor Output(Y)

0 0 0

0 1 0

1 0 1

1 1 0


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Timer Circuit:

This circuit introduces a time delay in the working. Consider the case

when a person gets up only to switch on the lamp. For such a short duration the automaticcontroller should not turn off the monitor, so we introduce a time delay. Let us consider amaximum delay of 10 seconds. This means that the monitor should turn off after 10seconds from the instant the user gets up from his chair. The Timer present in themicrocontroller can serve this purpose. Thus the timer circuit after a set period of tenseconds includes the control circuit.

Monitor control circuitry:

This circuitry includes an inverter, AND gate, which helps to switch off themonitor. Consider-

Inputs- Monitor status(A)Monitor OFF lowMonitor ON high

Switch position (B)User is seated (Normally opened) lowUser gets off (closed) high.

Output-Monitor status remains same lowMonitor turned off high


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In the first case monitor is in off condition and no user is seated and so the desired

output is that the monitor should be in off condition.In the second case when the monitor is in off condition and when the user is seated theoutput is that the monitor continues to remain in off condition.In the third case the monitor is in on state but the user is not in the chair, in this case theoutput is high which turns off the monitor .This happens after the time delay occurs. Thusconstructing a K-map to implement the following logic we get to use an inverter along with aAND gate.

Power Savings:

In a 24 hours working environment, Consider a 3 hr break.The state of the monitor will fall under 2 cases. 1. Switched ON, 2. Switched OFF.The monitor in the switched on condition infers to two possibilities, few may log off while theothers just leave it in on condition. Considering the change in power consumed under thesecases, the following calculations are made:

Total no: of Computers = 500;

No of Computers left inOff Condition = 250

Monitor power consumption = 60W (On)

No of Computers left inOn Condition = 150

Power savings = 150* 60* 3 (hr) * 30 (days)= 810 KWhr

No of Computers left inLog off Condition = 100

The log off mode in the system can be removed, it is being discussed later. So the onlyoption is to Shut Down the computer.

Power consumed in log off mode= 29 W;

Power Savings= 100* 89(60+29) * 3 * 30 = 801 KWhr


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Other than break hours:Let us consider the system monitor is being turned off about 1 hrs/day.

Power saved = 500 * 60(W) * 30(days) * 1(hr)= 0.9 MWhr

ENERGY EFFICIENT PRINTER

PROBLEM STATEMENT:

Printer forms a major part of a work place in an office. In a workingenvironment most of the officers use printers for their work. Though their use is rare, theprinters will be in standby mode for most of the time. The standby power of a printer is

11W. We need to reduce this wastage of power. Here we bring in the concept ofimplementing an embedded module which turns on the printer whenever the printcommand is received from the user.

Working principle of the embedded module:

We design a circuit in which the printer is switched on only when the print command isgiven by the user. This circuit includes a relay coil, off delay timer. Under normal conditionsthe relay coil is does not get any supply and hence there is no power supply to the printer.


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Also the timer is in off condition. But once a print command is given by the user, thegenerated pulse activates the relay coil and hence the printer gets the power supply

through the relay contacts. Also the off delay timer is energized. After the printer gets thepulse for the last page, the relay coil is automatically de energized. But the timer drives thecircuit for another 20 seconds, thus the printer prints the last page.

Power Savings Calculation:Printer:Power consumed by printer inStandby mode = 11 W

Assume printer works 2 hrs/day but switched on 24 hrs/day.

Considering printer switched off by few of them. The no of hrs is considered to be 20 hrs/day.

So total hrs in Standby mode= 20 hrs

Assuming there are 200 printers,

Power Savings/ Month = 20*11*200*30

= 1.32 MWhr

ENERGY EFFICIENT MOBILE CHARGER:

Introduction:

Mobile phones form an integral part of every individuals life in the present days. The powerconsumption of a mobile phone is around 6W.Very often we fail to switch off the supplyduring unplugged condition. The standby power of a mobile phone is nearly 0.6W.Thoughthis power appears to be small, when it comes to a company with 600 employees we reallyneed to reduce this wastage of power. We introduce a new design in the conventionalcharger circuit in order to minimize this wastage of power.

Proof of concept:

Here we design an energy efficient mobile charger which takes power from the supply onlywhen the charger is plugged in.


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Conventional model:

Though the standby power of a mobile phone is less ( 0.6 watts), we need to reduce thiswastage of power, when it comes to company with 600 employees, each having a mobilephone. This will lead to considerable amount of power saving in the monthly bills .Theconventional charger circuit is shown below, which includes a step down transformer,rectifier unit and a control unit.The major disadvantage of a conventional charger is that the charger gets activatedwhenever the transformer gets the supply.

BLOCK DIAGRAM OF A CONVENTIONAL MOBILE CHARGER

Innovation:

The modified mobile charger circuit is shown below. The primary terminals of the stepdown transformer are connected to the plugging end of the charger. Proper insulation hasto be provided. During unplugged condition, the primary terminal is disconnected from theplugging end because of the mechanical action(spring controlled) provided and hence thecircuit is open. Hence the charger does not get the power supply.


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OPTIMISED COMPRESSOR USING VFD TECHNIQUE:

INTRODUCTION:

Considering the problem statement of the company almost 60% of the power consumedby air conditioners. Thus by improving its working ,significant savings can be achieved. Themajor components of a AC are:

i. Compressorii. Condenseriii. Evaporator

Out of which the compressor plays a major role. By improving its basic motoring action its

efficiency can be improved.

CONCEPT:

Consider the office environment to be maintained at 22C. The compressor motor getsloaded whenever the temperature deviates from the set value. The motor would have beendesigned for maximum load current i.e. for maximum deviation say 8C. But mostly thismaximum deviation is not reached and the motor runs on lesser load only. We know thefact that maximum efficiency of a motor will be at the optimum load (approx. 80% of max.load). Hence here we try to achieve the maximum efficiency even at lower loads.

INNOVATION:

We know that, for Maximum Efficiency

Iron Loss = Copper Loss

Copper loss depends upon the load, whereas, the iron loss is going to be a constant for amotor. In case of lower loads, the copper loss is less. So if we reduce the iron loss andmake it equal to the copper loss, we can have a maximum efficiency.

We know that,

Iron loss= Hysteresis loss + Eddy Current loss

Hysteresis loss = Kh f Bm ; where Kh = Hysteresis Const,.

f = Frequency,

Bm = Maximum Flux Density.


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Eddy Current Loss = Ke f Bm ; where Ke = Eddy Current Const,.

So Iron loss directly depends upon the frequency. If we reduce the frequency, iron loss isconsiderably reduced.

Working:

The setup consists of embedded module fitted in the motor which monitors theparameters like load current, frequency, no .of poles, speed. Using the load current, copperloss is determined for a fixed wire resistance R .To obtain maximum efficiency, iron lossshould be made equal to this copper loss. Using this iron loss the proportional frequency iscalculated and is given as an input to the VFD (Variable Frequency Drive) for varying thefrequency. When frequency reduces ,correspondingly, the speed varies by the relation

N = (120f)/P

But speed has to be maintained constant, which is achieved by increasing the no. of poles.Thus the required no. of poles are calculated. Accordingly the poles can be energized; thisis achieved by introducing a new a modification in the windings. The windings are designedin such a way that the entire mesh gets divided into the no. of poles obtained as an inputfrom the microcontroller.

The Motor Efficiency Vs Load graph is plotted. This graph is plotted for a practical motor.


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Thus by this design the maximum efficiency is achieved at any percentage of load.

Motor Power Savings Calculation:

Given that 60% of energy consumption is due to AC.

Power consumed by AC = .6 * 341 = 204.6 MW

About 90% of AC energy is consumed by motor,

Power consumed by the Motor

in the compressor = 180 MW

Mostly the motor runs at 30% of load, its efficiency is about 50% (from graph)

Efficiency = (Pin losses)/ Pin ;

0.5 = (180 - losses) / 180;

Losses = 90 MW;

In our method, the efficiency attained will be about 85%;

0.85 = (180 losses)/ 180

Losses = 27 MW.So we have reduced the losses by 63 MW (90 27 MW)

A Step ahead:

This principle can be implemented for lifts, as they operate mostly on varying load. Thistechnique will be effective considering the operating conditions of a lift.


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AN INNOVATIVE APPROACH TOWARDS OPTIMISATION:

Small changes often have great impacts.The following are some simple suggestions which have a greater impact towards power

optimization.

I. COMPUTER:I.a. Computers have become the essential part of life. They also become a major source ofpower wastage when kept in an idle state. Consider a company with significant no.ofpersonal computers; if the employee has to leave shortly, he usually has the tendency tolog off instead of turning off the computer. 'Log Off' means that all your programs will be

closed and you will be taken out of Windows, but the PC will not be turned off.'Shut down' means that you will be taken out of Windows and the machine is turned off,thus power consumed is more in the former. If the log off mode has been removed, theuser is forced to shut down the system thereby saving almost ----

I.b. The other change that can be brought about is reducing the power consumption in CDdrives. It can be averaged that the drive utilizes 2% of the total power consumed by acomputer (1.2W app.).With the advent of pen drives, the use of CD drives can be avoidedas the pen drives prove to be more energy efficient with higher transfer rates. The companymight remove the option for CD drive utilization.

II. Energy savings using ID recognition System:Most of the companies have the system of computerized ID Recognition. This system canbe programmed in such a way that a counter that counts up the no.of persons entering andthat which counts down the no.of persons leaving so that when both tally the systemactivates a switch that turns off the supply to that room.

III. According to the problem statement there are 2 lifts. These lifts can be positioned in thecenter of the buildings and not at the extremes. Consider a condition where 3 people fromleft extreme and other 3 people from right extreme are in a need to use the lift. Incase if thelifts are placed at the extreme ends of the building, preferentially they will opt their nearestlift. Thus 2 lifts will operate. If the lifts are placed at the center of the building, all 6 peoplewill use a same lift.

IV. In a working area, definitely there will be a canteen. Mostly it will be located at the topfloor. Our suggestion is that the cooking area should be at the top floor and the distributioncan be in each floor. It reduces the frequent usage of lift during break.

All these suggestions when implemented might save significant amounts in themonthly bill.


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Net Power Savings:

Power saved in Computers = 2.511 MWhr

Power saved in Printers = 1.32 MWhr

Power saved in Air Conditioners = 63.0 MWhr

Power saved in other ideas = 0.169 MWhr

Total Power Savings = 67 MWhr

Future Work Possible:

The below proposal is of ongoing research area. This will also have a greater powersavings.

INTRODUCTION:

As the performance of todays processors increases rapidly their power consumptionalso increases and hence the heat generation. But these must be maintained as cool aspossible to have good performance characteristicsThe most common symptoms of an overheating processor are system crashes, lockupsand random reboots. An overheating processor can also manifest itself through memoryerrors, application errors, disk problems, or a host of other things. A severely overheatedprocessor can also be permanently damaged, although this happens rarely.

A conventional processor can produce up to 85W as heat, while servers release asmuch as 600W as heat and the case temperature reaches about 75 78C. Henceprocessors are cooled using metal heat sinks, which has its own disadvantages like poorheat dissipation and bulky.

In this project we are going to determine the heat transfer characteristics of metalfoams and how effective will they be in replacing the conventional heat sinks.


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Conventional cooling in processors:

Passive Heat Sinks

The first type of cooling applied to processors was the heat sink, a device used for avery long time in electronics to cool hot devices. Your television and stereo have used themfor years, and you will find them in your and even on your motherboard in most cases.These are now sometimes called "passive" heat sinks as well, the term meaning simplythat there are no moving parts with this type of cooler, unlike a mounted fan which is oftencalled an "active" heat sink.

Active Heat Sinks / CPU Fans

An active or CPU fan is an enhancement to the standard. It too uses a finned piece ofmetal attached to the surface of the to conduct heat away from the CPU so it can be cooledby air. However, active heat sinks go one step further, adding a small fan that blows directlyonto the heat sink metal to ensure direct air cooling.

Forced Convection

Forced convection is a mechanism of transport in which fluid motion is generated byexternal source (like pump, fan, suction device, moving solid object). In forced convection,values of the heat transfer coefficient are usually much larger than in natural convection.Some examples of forced convection are fluid being pumped through a, pipe flow, flow overa plate at different temperature than the stream temperature. However, in any forcedconvection situation, some amount of natural convection is always present and such flowsare called as mixed convection.


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When natural convection doesn't significantly influence mixed convection, analysiswith forced convection yields accurate results. The parameter of importance in forced

convection is the, which is the ratio of advection and diffusion.

Metal Foams:

A metal foam is a cellular structure consisting of a solid metal, containing a largevolume fraction of gas-filled pores. The pores can be sealed (closed-cell foam), or they canform an interconnected network (open-cell foam). The defining characteristic of metalfoams is a very high porosity: typically well over 80% of the volume consists of void spaces.

Open-cell metal foams

Open celled metal foams have a structure similar to open-celled polyurethanefoams and have a wide variety of applications including heat exchangers (compactelectronics cooling, cryogen tanks, PCM heat exchangers), energy absorption, flowdiffusion and lightweight optics. Due to the high cost of the material it is most typically usedin advanced technology aerospace and manufacturing. Extremely fine-scale open-cellfoams, with cells too small to be visible to the naked eye, are used as high-temperaturefilters in the chemical industry.

Closed-cell metal foams

Closed-cell metal foams have been developed since about 1990, and are commonlymade by injecting a gas or foaming agent into molten metal. The size of the pores - or 'cell

size' - is usually between 1 mm and 8 mm.Closed-cell metal foams are primarily used as an impact-absorbing material, similarly to thepolymer foams in a bicycle helmet but for higher impact loads. Unlike many polymer foams,metal foams remain deformed after impact, and can therefore only be used once. They arelight (typically 10% of the density of the metal they are made of, which is usually aluminium)and stiff, and are frequently proposed as a lightweight structural material.


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Closed cell foam

Current Applications:

Applications in impact-absorbing systems probably offer the greatest potential formetallic foams. Their exceptional ability to absorb large amounts of energy at almostconstant pressure suggests applications ranging from automobile bumpers to aircraftcrash recorders

Metal foams have low density with good shear and fracture strength and are ideal forsandwich construction. The resulting structure can be used for energy absorptionand for lightweight structural applications.

The acoustic properties of metallic foams mean that they find uses in many placeswhere sound absorption is vital, e.g. along the sides of a road to reduce traffic noise.

Open cell foams have large accessible surface area and high cell-wall conductiongiving exceptional heat transfer ability.

Metal foams are also finding architectural applications purely on the basis of theiraesthetic quality; their light weight is an added advantage

Metal foam is an excellent material for arresting flames in such environments asalong pipes and ventilating enclosures. They are both fire proof and highlypermeable. They may also be used in blast protection applications.

Other applications include:

Chemical filters Heat exchangers, filters, catalysts Instrument housing Gearbox housings Structural parts for spacecraft


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Properties of metal foams:

large accessible surface area

Weldable & ductile. Superior overall thermal conductivity. Lightweight Stiff Incombustible, non-toxic

Porosity:Consider a sample of total volume V. Define the volume of the solid phase to be Vs, and

the volume of the pore phase (the holes) to be Vp, with V = Vs + Vp. The volume fraction isa normalized variable that is generally more useful. The volume fraction of the pore phase

is commonly called the porosity, and is denoted = Vp / V

PPI : Pores per inchNumber of pores in inch. Inversely proportional to pore size


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PROPOSED DESIGN SET UP:


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Experimental setup

1) Heaters2) Insulation3) Thermocouples4) Temperature indicator5) Fan6) DC power supply

Heaters:Heat flux necessary: 85W / (3 * 3 cm) = 9.44W/cm2Temperature to be maintained: 75C (normal operating temp of processor)Type of heater to be used: Thermofoil heaters

Advantages of Silicone rubber heaterSilicone rubber is a rugged, flexible elastomer material with excellent temperature

properties- Rugged construction provides high reliability in a wide range of heating applications.- Optional custom profiled heat density creates a uniform heat sink temperature which canimprove processing yields.- High temperature capability to 235C (455F)

FanAn axial flow fan used in desktops with varying rpm and dimensions.

DC power supply:Depends on the heater specifications

References:

en.wikipedia.org/wiki/Variable-frequency_driveen.wikipedia.org/wiki/Metal_foam

http://www.switches.machinedesign.com/guiEdits/Content/bdeee4/bdeee4_17.aspx

www.howeverythingworks.org/lecture_slides/air_conditioners.ppt

schneider innovation challenge 2010

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