Energy Balance For An Internal Combustion Engine Engineering Essay

might Balance For An home(a) Combustion Engine Engineering EssayThe main objective of the investigate is to stripe the button contributions to the diesel motor locomotive rail room locomotive locomotive locomotive railway locomotive, which is treated as a thermodynamics musical arrangement. The slide fastener contributions that are not measured may thus be estimated from an thrust balance. at that place are two main, unmeasured zip contributions to identify-An free energy loss from incomplete burn, in which some of the raise is not burned completely.An energy loss by heat transfer to the give vent adjoin heated engine components.IntroductionA Petter 4 buffet diesel engine will be used to investigate the efficacy of a diesel engine. diesel engine engines areinner burning at the stake enginesdesigned to convert the chemical energy lendable in the fuel, into mechanic all toldy skillful energy. This mechanical energy moves the pistons up and down inside( a) cylinders. The pistons are connected to a crankshaft, and the up-and-down motion of the pistons, known as lin head motion, creates the rotary motion undeniable to turn the wheels of a car forward.We are already aware of the fact that internal combustion engines take a crap very low efficiencies, but the designing of such experiment is to study where and how the energy is used and lost. This would help us to improve the susceptibility of the internal combustion engines where ever possible.Theory some(prenominal) diesel engines and petrol engines convert fuel into energy through a series of small explosions or combustions. The major difference between diesel and petrol engines is the way these explosions happen. In a petrol engine, fuel is conflate with stock, fuddled by pistons and hot upd by sparks from spark plugs. In a diesel engine, however, the bloodline is compressed first, and then the fuel is injected, because as the impart is compressed it heats up to around 400 C, it is hot enough to ignite fuel.A four stroke diesel engine uses the following motorbike (illust rankd in introduce1)Intake stroke The intake valve opens, and fresh oxygenize (containing no fuel), is drawn into the cylinder, moving the piston down.Compression stroke As the piston rises, the air is compressed, causing its temperature to rise. At the end of the compression stroke, the air is hot enough to ignite fuel.Combustion stroke As the piston reaches the top, fuel is injected at just the right moment and ignited, forcing the piston back down. clear stroke The piston moves back to the top, pushing out the baffle created from the combustion out of the exhaust valve. accede 124075-004-613c6f14.gifEq1From the basic steady come energy equation, using the air-cycle method, we may write-The value of shadow be approximated, closely, to, Cpe is taken as 1 nose fannydyJ/KgKIt is convenient to replace by in point to make an spareance for the possibility of incomplete combustion. *Where, FL, is the proportion of fuel energy that is not available because of incomplete combustion. combust transfer, (Qr), is the sum of energy transferred to chilling piss and energy lost to the surrounding from hot engine components, and then we can writeQr = -dot mw Cpw ( Tout Tin ) + QrnReplacing all quantities in Eq1 we getSymbols explained as followsrate of heat energy transfer of systemrate of the work through with(p) by the system ( indicator)combustion air mass flow ratefuel mass rateparticular proposition enthalpy of products of combustion special enthalpy of combustion airspecific heat of water 4190 J/kgKApparatusThe Apparatus used in this experiment is mentioned as followsPetter Diesel Engine A four stroke, single cylinder, 659CC Petter Diesel Engine was used to conduct the experiment. Figure 2 shows the imprint of Petter Diesel Engine used in the experiment.Ear Muffles Ear muffles were used to protect the ears from the loud noise of the diesel engine prolonged e xposure to such loud noise without ear protection can lead to hearing impairment.Barometer A Barometer was used to measure the atmospheric pressure at the duration of experiment. Atmospheric pressure was mandatory to calculate the mass flow rate. The Barometer gives readings in mmHg. Figure 3 shows the picture of barometer used in the experiment.IMG_4763.JPGIMG_4767.JPGFigure 2 Figure 3 observational ProcedureThe purpose of this experiment was to investigate the capacity of a diesel engine. To start with the experiment, all the gauges on the apparatus were pre set to default readings and as a safety precaution all students were provided with ear muffles. Each respective(prenominal) group member was assigned a task by the staff lecturer. My assigned task was to measure the oil and at the same quantify, time the engine as it call ford the set amount of diesel. Similarly other students were prone tasks, which they carried on doing as the experiment progressed.The engine was star ted and after waiting for the recommended time of ten minutes, all the readings were taken off gauges. A weight of 5kg was already placed onto the torque arm before starting the engine. Measurements such as fuel flow rate, cooling water flow-rate, spring balance, orifice denture pressure be sick, speed gauge and electric thermometer were taken.Electric thermometer reading is change integrity into four parts, mentioned as follows wear upon temperature engine cooling system water inlet temperature chill water outlet temperatureAir inlet temperatureAfter taking all the readings, engine was shut down and ear muffles were removed. The readings taken off the gauges were then used to work out the energy balance for an internal combustion engine.ResultsMEASURED PROPERTYVALUEUNITSAtmospheric Pressure764mmHgEngine speed1500rpmSpring balance reading15N potentiometer on torque arm5KgAmount of discharge measured20mlTime to consume fuel97SecondsRelative density of fuel0.864Orifice plate pres sure drop31mmH2OExhaust gas temperature260Degrees CelsiusCooling water inlet temperature69Degrees CelsiusCooling water outlet Temperature75Degrees CelsiusAir inlet Temperature18.5Degrees CelsiusCooling water flow-rate5litres/minuteFollowing readings were obtained from the gauges1. fuck power widening= torque* shaft rotational speed= W(kg load -dial reading)*rt*N(rpm)*2/60= (5*9.81)-15*0.4*1500*2/60= 2139.42 Watts= 6.13 10-3 kg/s3. Fuel flow rate == (20 10-3/ coke0) (864)= Kg/s4. kindle transfer rate to the cooling water = (l/min)/60 * 4.196* (Tout Tin)= *4.196*(75-69)= 2.098 kJ/s5. Heat transfer to exhaust gases= (6.24= 1.70 kJ/s6. readiness BalanceFuel Energy Input = mf*LCV= (1.7810-4) x (43106)= +7654WShaft Power Output= + 2139.42WCooling Water Heat Transfer= +2098WExhaust Heat Transfer = +1700WEnergy Transfer =Qm-mf *FL= -7654+2139.42+2098+1700= -1716.58WEfficiency = n= profitable work outputfuel energy input=2139.42 x 1007654=27.95% (Useful Work)Energy to milieu = (Heat su pplied in fuel Useful work done Energy to coolant Energy to exhaust)= 7.66 2.14 2.10 1.68= 1.74KWPercentage energy to coolant = Energy to coolant 100Heat supplied in fuel= x 100= 27.41%Percentage to exhaust = Energy to exhaust 100Heat supplied in fuel= x 100= 21.93%Percentage loss to the surrounding = Energy to surroundings 100Heat supplied in fuel= x 100= 22.71%pie chart.jpgFigure 5Figure 4DiscussionEngine capability refers to an engines ability to transform the available energy from its fuel into useful work. The modern petrol combustion engine operates at an average of roughly 20 to 30 share engine efficiency. The remaining 70 to 80 percent of the energy is lost to the surroundings in form of exhaust heat, mechanical sound energy and friction.Diesel engines are a bit to a greater extent than efficient. Thediesel engineuses blue compression to ignite its fuel. This higher compression compensates for the engines heat losses and results in roughly 40 percent engine eff iciency. This engine efficiency is unaccompanied observed by direct injection diesel engines (discussed later). Rest 60 percent energy, like the petrol engine is lost to the surroundings.The Petter diesel engine which was the subject of this experiment showed a poor boilersuit efficiency compared to an average diesel engine. The overall efficiency of the Petter diesel engine was single 27.95 percent. The reason for such poor efficiency was that most of the energy was lost to surrounding, but that doesnt mean that the engine cannot me made more efficient. agnise Figure 4 and 5 for the distribution of energy lost and utilised.There are many ways to improve the efficiency of a diesel engine, some are discussed belowTurbochargers The purpose of a turbocharger is to compress the air flowing into the diesel engine, this lets the engine squeeze more air into a cylinder and more air means that more fuel can be added basically a turbocharger converts waste energy from an engines exhaust ga ses into compressed air, which it pushes into the engine. This allows the engine to burn more fuel producing more power and improves the overall efficiency of the combustion process, hence making the engine more efficient. However, the only disadvantage of a turbocharger is that, if it is in a cars engine it would take a few second to respond as the driver presses the pedal, this phenomenon is known as lag. Turbocharger suffers from lag because it takes a few moments before the exhaust gases reach a velocity that is sufficient to drive the impeller/turbine.Direct Injection With direct injection, the diesel fuel is directly injected into the cylinder i.e. fuel is mixed with air inside the cylinder, allowing for better control over the amount of fuel used, and varies depending on demand. This makes the engine more fuel efficient. Before direct injection, the fuel was mixed with air in the cars intake manifold.Variable Valve Timing Valves open and close to allow air and fuel to enter c ylinders and for the products of combustion to exit. Different valve timings produce contrasting results (more power and or better fuel economy). Many modern engines can vary valve timing, allowing the default low RPM range of the engine to have more economical timing, and the higher RPM range to go for gunk power.Cylinder Deactivation Internal Combustion Engines, with this feature can obviously deactivate some cylinders when less power is required, temporarily reducing the match volume of the engine cylinders and so burning less fuel. This feature is more often than not found on V6 and V8 engines.Super Charger Superchargers increase the intake of air into the combustion chamber. This means, more air into the combustion chamber and with more air, more fuel can be added, and more fuel means a bigger explosion and greaterhorsepower. Adding a supercharger is a good way to increase the power of a normal-sized engine and thus making it more efficient. Superchargers also create bette r fuel efficiency by change magnitude the amount of oxygen available to an engines combustion chambers, because superchargers increase the power of the engine by utilising more oxygen, they do not require a larger engine and therefore also increase fuel efficiency by allowing cars to be lighter. The biggest disadvantage of superchargers however, is that they steal some of the engines horsepower. A supercharger can consume as much as 20 percent of an engines total power output but also generates as much as 46 percent additional horsepower. Since, it generates more power than it requires, it is generally thought to be good option to increase engines efficiency.ConclusionDiesel engines are a form of Internal Combustion Engines. They are very inefficient if on the job(p) on their own. Generally about 25-30 percent energy is used in work and the rest is lost to surroundings. The efficiency of a diesel engine can be enhanced by at least 10-15 percent if combined with the modern technol ogical devices, such as turbochargers and superchargers. Other given(p) techniques can also be used to improve the fuel efficiency and overall engine efficiency of the engine, such as direct injection, variable valve timing and cylinder deactivation.Unfortunately, from the very beginning the focus on an internal combustion engine has been on producing more power rather than providing a better fuel economy, but nowadays due to growing sentiency of environment and rising oil prices, engineers have shifted their attention on to producing more fuel efficient engines. For example, BMW is researching on ways to increase the fuel efficiency of a conventional engine by 10-15 percent by expression torecover and reuse heat energylost through the exhaust and that absorbed by the engine cooling system. With such initiatives we can jibe a future of more efficient and more environmentally hail-fellow-well-met engines.