ENGINE TEST SET UP 3 CYLINDR, 4 STROKE, PETROL Instruction manual
ENGINE TEST SET UP 3 CYLINDR, 4 STROKE, PETROL Product Code 231 Instruction manual Contents 1 2 3 4 Description Specifications Installation requirements Installation Commissioning 5 6 7 8 Troubleshooting Components used Packing slip Warranty 9 Theory 10 Experiments APEX INNOVATIONS 21-01-2014 Im231.docx Page 1 Apex Innovations Description The setup consists of three cylinder, four stroke, Petrol engine connected to Eddy dynamometer for engine loading. The setup has standalone type independent panel box consisting of air box, fuel tank, manometer, fuel measuring unit, digital speed indicator and digital temperature indicator. Engine jacket cooling water inlet, outlet and calorimeter temperature is displayed on temperature indicator. Rotameters are provided for cooling water and calorimeter flow measurement. The setup enables study of engine for brake power, BMEP, brake thermal efficiency, volumetric efficiency, specific fuel consumption, air fuel ratio and heat balance. Set up is supplied with MS Excel program for Engine Performance Analysis. F1 F2 Fuel Air F3 F4 T2 Wt T1 T3 N T4 DYNAMOMETER T5 ENGINE Specifications Product Engine test setup 3 cylinder,4 stroke, Petrol Product code 231 Engine Make Maruti, Model Maruti 800, Type 3 Cylinder, 4 Stroke, Petrol (MPFI), water cooled, Power 27.6Kw at 5000 rpm, Torque 59 NM at 2500rpm,stroke 72 mm, bore 66.5mm, 796 cc,CR 9.2 Dynamometer Type Eddy current, water cooled with loading unit (Arm length 210 mm) Propeller shaft With universal joints Air box M S fabricated with orifice meter and manometer (Orifice dia 35 mm) Fuel tank Capacity 15 lit with glass fuel metering column Calorimeter Type Pipe in pipe Temperature sensor Thermocouple, Type K Temperature Digital, multi channel with selector switch indicator Speed indicator Digital with non contact type speed sensor Load sensor Load cell, type strain gauge, range 0-50 Kg Load indicator Digital, Range 0-50 Kg, Supply 230VAC Rotameter Engine cooling100-1000 LPH;Calorimeter 25-250 LPH Pump Type Monoblock Overall dimensions W 2000 x D 2750 x H 1750 mm Shipping details 21-01-2014 Im231.docx Page 2 Apex Innovations Gross volume 1.64m3, Gross weight 755kg, Net weight 910kg Installation requirements Electric supply Provide 230 +/- 10 VAC, 50 Hz, single phase electric supply with proper earthing. (Neutral – Earth voltage less than 5 VAC) 5A, three pin socket with switch (2 Nos.) Water supply Continuous, clean and soft water supply @ 4000 LPH, at 10 m. head. Provide tap with 1” BSP size connection Space 3500Lx4000Wx2000H in mm Drain Provide suitable drain arrangement (Drain pipe 65 NB/2.5” size) Exhaust Provide suitable exhaust arrangement (Exhaust pipe 32 NB/1.25” size) Foundation As per foundation drawing Fuel, oil Petrol @10 liter Oil @ 3.5 lit. (15W40) Installation Commissioning INSTALLATION Unpack the box(es) received and ensure that all material is received as per packing slip (provided in instruction manual). In case of short supply or breakage contact Apex Innovations / your supplier for further actions. Install engine test set up assembly on the foundation. Keep panel box structure and dash board panel near foundation (Refer foundation drawing ) Fit the panel box assembly on the panel box structure and fit following parts o Temperature indicator o Load indicator o Speed indicator Complete the piping work as follows: o Exhaust: Engine to calorimeter o Water: Dynamometer inlet, outlet, Engine cooling inlet, outlet, Calorimeter water inlet outlet and drain pipe. o Air: Air box to engine o Fuel: Fuel measuring unit to engine Fit the following parts o Pressure gauge on dynamometer inlet pipe. o Temperature sensors (Thermocouples) o Speed sensors on dynamometer (driving end and non driving end) o Load cell to dynamometer. Keep the Dashboard panel between engine and panel box. Fit the following units and connect to engine: o Battery o Gauges o Throttle unit Complete the wiring work as follows: 21-01-2014 Im231.docx Page 3 Apex Innovations o o o o Speed sensor to speed indicator Load cell to load indicator Temperature sensors to Temperature indicator Dynamometer to Dynamometer loading unit and proximity switch to DLU COMMISSIONING Confirm foundation bolts and propeller shaft bolts are properly tightened. Ensure cover guard on propeller shaft and fan guard is placed. Fill lubrication oil in the engine Fill fuel in the fuel tank. Remove air from fuel line connecting fuel measuring unit to fuel transmitter. Lower jack bolts under dynamometer for free movement. Provide electric supply to panel box o Confirm all temperatures are correctly displayed on Temperature indicator o Confirm load signal displayed on Load indicator Fill water in the manometer up to “0” mark level. Ensure water circulation through engine, calorimeter and dynamometer. The water pressure for dynamometer should be @1 to 1.5 kg/cm^2 Press heater switch for some time and then start the Engine. Check engine operation at various loads and ensure respective signals on indicators. Precautions Use clean and filtered water; any suspended particle may clog the piping. Circulate dynamometer cooling water for some time after shutting down the engine. Troubleshooting Note: For component specific problems refer components‟ manual Problems Possible causes / remedies Engine does not start Water circulation pump not switched on Discharged Battery Check Engine wiring connector Insufficient fuel /Air trapped in fuel line Dynamometer may be fully loaded from DLU Dynamometer does Loose connection from DLU to dynamometer not load the engine Proximity for speed feedback not connected Improper gap between speed feedback proximity and rotating object. Gap should be 5-8 mm. Engine not steady Improper gap of speed feedback proximity sensor after loading connected to DLU. Gap should be 5-8 mm. Faulty air flow Air hose leakage at connections with air-box and with engine. Faulty fuel flow Improper closing of fuel cock. Faulty speed Improper gap between speed sensor and rotating indication object. Gap should be 5-8 mm. Faulty load indication Excessively raised dynamometer jack bolts Damaged load cell due to overstressing Incorrect Check the connection between thermocouple and temperature temperature indicator/transmitter. Note that yellow indication cable of thermocouple is positive and red is 21-01-2014 Im231.docx Page 4 Apex Innovations negative. Open or damaged temperature sensor Components used Components Details Engine Make Maruti, Model Maruti 800, Type 3 Cylinder, 4 Stroke, Petrol (MPFI), water cooled, Power 27.6Kw at 5000 rpm, Torque 59 NM at 2500rpm,stroke 72 mm, bore 66.5mm, 796 cc,CR 9.2 Make Saj test plant, Model AG80, Type Eddy current Make Hindustan Hardy Spicer, Model 1260, Type A Make Apex, Model MX-104, Range 100-0-100 mm, Type U tube, Conn. 1/4`` BSP hose back side, Mounting panel Make Apex, Glass, Model:FF0.090 Make Radix Type K, Ungrounded, Sheath Dia.6mmX110mmL, SS316, Connection 1/4"BSP (M) adjustable compression fitting Temperature Indicator, make ESD, model ESD 9043, 230VAC, Input Thermocouple, 6 point, Range 01000deg.C. RPM Indicator, make Selectron, model RC 100A, Range 6000, 85 to 270VAC/DC with Photoelectric sensor, NPN (5-30 volt DC) Make Sensotronics Sanmar Ltd., Model 60001,Type S beam, Universal, Capacity 0-50 kg Load Indicator, make Selectron, model PIC 152 - B3, 85 to 270VAC/DC, Input - Load cell, Range 0-50 Kg. Make Cuadra, Model AX-153, Type veriable speed, Supply 230V AC. with Photoelectric sensor type PNP Make Eureka Model PG 5, Range 25-250 lph, Connection ¾” BSP vertical, screwed, Packing neoprene Make Eureka, Model PG 9, Range 100-1000 lph, Connection 1” BSP vertical, screwed, Packing neoprene Pump make Kirloskar, Model KDS-128+, Head 20m., HP 1.0, Single phase, Size 25x25 Type Centrifugal monoblock 12 V DC Dynamometer Propeller shaft Manometer Fuel measuring unit Temperature sensor Temperature indicator Speed indicator Load sensor Load indicator Dynamometer Loading unit Rotameter Rotameter Pump Battery 21-01-2014 Im231.docx Page 5 Apex Innovations Packing slip Total no. kg Case No.1/10 1 Box No.2/10 1 Box No.3/10 1 Box No.4/10 1 Box No.5/10 1 Box No.6/10 1 Box No.7/10 1 Box No.8/10 1 2 Box No.9/10 1 2 3 4 5 6 7 8 9 10 11 12 13 of boxes: 10, Volume: 2.54 m3, Gross weight: 860 kg. Net wt. 684 Engine Set up Assembly Size W1700xD800xH1200 mm; Volume:1.63m3 Engine test setup assembly Engine + Dynamometer + Base frame Engine panel box Size W990xD475xH500 mm; Volume:0.24m3 Engine panel box assembly Manometer with PU tube. Engine panel box structure Size W800xD475xH500 mm; Volume:0.19m3 Engine panel box structure assembly Rotameters with piping (2) Dynamometer loading unit clamp (1) Calorimeter Size W650xD275xH325 mm; Volume:0.06m3 Calorimeter assembly Exhaust pipe Size W900xD200xH250 mm; Volume:0.05m3 Exhaust pipe Gross weight: 475kg Net weight: 475kg 1 No. Pump Size W525xD325xH425mm; Volume:0.07m3 Pump Battery Size W150xD225xH250 mm; Volume:0.01m3 Battery Dash board Size W500xD400xH300 mm; Volume:0.06m3 Dash board panel with support structure Fuel throttle body with cable Engine wiring Size W500xD400xH300 mm; Volume:0.06m3 Temperature indicator Load indicator RPM Indicator Dynamometer loading unit Pressure gauge Wiring set Load cell with nut bolt RPM sensor Temperature sensor (5) Set of loose nut bolts Tool kit Fuel caps(2), Teflon tape(2) & Gasket shellac(1) Set of instruction manuals consisting of: Instruction manual CD (Apex) Dynamometer Calibration sheets for load cell Gross weight: 42kg Net weight: 23kg 1 No. Gross weight: 25kg Net weight: 17kg 1 No. Gross weight: 32kg Net weight: 20kg 1 No. 1 No. Gross weight: 30kg Net weight: 12kg 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 1 No. 21-01-2014 Im231.docx Gross weight: 78kg Net weight: 50kg 1 No. Gross weight: 56kg Net weight: 31kg 1 No. Gross weight: 45kg Net weight: 22kg 1 No. Gross weight: 17kg Net weight: 9kg 1 No. Page 6 Apex Innovations Box No.10/1 0 1 2 3 4 5 6 7 8 9 10 11 Engine piping Size W1250xD450xH350mm; Volume: 0.20m3 Gross weight: 60kg Net weight: 25kg Piping set (14 pieces) Engine water inlet and outlet, Dynamometer water inlet and outlet, Calorimeter water inlet and outlet, Air hose pipe, Pump suction connection with strainer, Pump outlet, Engine water inlet and outlet hose, Water supply hose pipe, Drain pipe (3 components) Water supply pipe 1.25” hose Load cell bracket Fuel measuring unit 2Nos (one spare) Wiring channel set Engine air connection pipe Fuel filter assembly Exhaust extension pipe with socket and bend Pump bracket Air box connection Calorimeter exhaust outlet flange 1 No. 21-01-2014 Im231.docx 1 1 1 1 1 1 1 1 1 1 No. set No. No. No. No. No. No. No. No. Page 7 Apex Innovations Warranty This product is warranted for a period of 12 months from the date of supply against manufacturing defects. You shall inform us in writing any defect in the system noticed during the warranty period. On receipt of your written notice, Apex at its option either repairs or replaces the product if proved to be defective as stated above. You shall not return any part of the system to us before receiving our confirmation to this effect. The foregoing warranty shall not apply to defects resulting from: Buyer/ User shall not have subjected the system to unauthorized alterations/ additions/ modifications. Unauthorized use of external software/ interfacing. Unauthorized maintenance by third party not authorized by Apex. Improper site utilities and/or maintenance. We do not take any responsibility for accidental injuries caused while working with the set up. Apex Innovations Pvt. Ltd. E9/1, MIDC, Kupwad, Sangli-416436 (Maharashtra) India Telefax:0233-2644098, 2644398 Email: [email protected] Web: www.apexinnovations-ind.com 21-01-2014 Im231.docx Page 8 Apex Innovations Theory TERMINOLOGY Engine Cylinder diameter (bore) (D): The nominal inner diameter of the working cylinder. Piston area (A): The area of a circle of diameter equal to engine 2 cylinder diameter (bore). A / 4 D Engine Stroke length (L): The nominal distance through which a working piston moves between two successive reversals of its direction of motion. Dead center: The position of the working piston and the moving parts, which are mechanically connected to it at the moment when the direction of the piston motion is reversed (at either end point of the stroke). Bottom dead center (BDC): Dead center when the piston is nearest to the crankshaft. Sometimes it is also called outer dead center (ODC). Top dead center (TDC): Dead center when the position is farthest from the crankshaft. Sometimes it is also called inner dead center (IDC). Swept volume (VS): The nominal volume generated by the working piston when travelling from one dead center to next one, calculated as the product of piston area and stroke. The capacity described by engine manufacturers in cc 2 is the swept volume of the engine. Vs A L / 4 D L Clearance volume (VC): The nominal volume of the space on the combustion side of the piston at top dead center. Cylinder volume: The sum of swept volume and clearance volume. V Vs Vc Compression ratio (CR): The numerical value of the cylinder volume divided by the numerical value of clearance volume. CR V / Vc 21-01-2014 Im231.docx Page 9 Apex Innovations Bore D Cylinder head Suction valve Intake or suction manifold Top dead center T.D.C. Piston Gudgeon or wrist pin Exhaust valve Exhaust manifold Clearance volume.Vc Cylinder volume’V’ Stroke volume.Vs Bottom dead center B.D.C. Cylinder Connecting rod Crankcase Crankshaft Crank pin Crank Important positions and volumes in reciprocating engine Four stroke cycle engine In four-stroke cycle engine, the cycle of operation is completed in four strokes of the piston or two revolutions of the crankshaft. Each stroke consists of 180 0 of crankshaft rotation and hence a cycle consists of 7200 of crankshaft rotation. The series of operation of an ideal four-stroke engine are as follows: 1. Suction or Induction stroke: The inlet valve is open, and the piston travels down the cylinder, drawing in a charge of air. In the case of a spark ignition engine the fuel is usually pre-mixed with the air. 2. Compression stroke: Both valves are closed, and the piston travels up the cylinder. As the piston approaches top dead centre (TDC), ignition occurs. In the case of compression ignition engines, the fuel is injected towards the end of compression stroke. 3. Expansion or Power or Working stroke: Combustion propagates throughout the charge, raising the pressure and temperature, and forcing the piston down. At the end of the power stroke the exhaust valve opens, and the irreversible expansion of the exhaust gases is termed „blow-down‟. 4. Exhaust stroke: The exhaust valve remains open, and as the piston travels up the cylinder the remaining gases are expelled. At the end of the exhaust stroke, when the exhaust valve closes some exhaust gas residuals will be left; these will dilute the next charge. Two stroke cycle engine In two stroke engines the cycle is completed in two strokes of piston i.e. one revolution of the crankshaft as against two revolutions of four stroke cycle engine. The two-stroke cycle eliminates the separate induction and exhaust strokes. 21-01-2014 Im231.docx Page 10 Apex Innovations 1. Compression stroke: The piston travels up the cylinder, so compressing the trapped charge. If the fuel is not pre-mixed, the fuel is injected towards the end of the compression stroke; ignition should again occur before TDC. Simultaneously under side of the piston is drawing in a charge through a springloaded non-return inlet valve. 2. Power stroke: The burning mixture raises the temperature and pressure in the cylinder, and forces the piston down. The downward motion of the piston also compresses the charge in the crankcase. As the piston approaches the end of its stroke the exhaust port is uncovered and blowdown occurs. When the piston is at BDC the transfer port is also uncovered, and the compressed charge in the crankcase expands into the cylinder. Some of the remaining exhaust gases are displaced by the fresh charge; because of the flow mechanism this is called „loop scavenging'. As the piston travels up the cylinder, the piston closes the first transfer port, and then the exhaust port is closed. Performance of I.C.Engines Indicated thermal efficiency (ηt): Indicated thermal efficiency is the ratio of energy in the indicated power to the fuel energy. t IndicatedP ower / FuelEnergy t (%) IndicatedP ower ( KW ) 3600 100 FuelFlow ( Kg / Hr) CalorificV alue( KJ / Kg ) Brake thermal efficiency (ηbth): A measure of overall efficiency of the engine is given by the brake thermal efficiency. Brake thermal efficiency is the ratio of energy in the brake power to the fuel energy. bth BrakePower / FuelEnergy bth (%) BrakePower ( KW ) 3600 100 FuelFlow ( Kg / Hr) CalorificV alue( KJ / Kg ) Mechanical efficiency (ηm): Mechanical efficiency is the ratio of brake horse power (delivered power) to the indicated horsepower (power provided to the piston). m BrakePower / IndicatedP ower and Frictional power = Indicated power – Brake power Following figure gives diagrammatic representation of various efficiencies, Energy lost in exhaust, coolant, and radiation Energy lost in friction, pumping etc. Energy in fuel (A) IP (B) BP (C) 21-01-2014 Im231.docx Page 11 Apex Innovations Indicated thermal efficiency = B/A Brake thermal efficiency = C/A Mechanical efficiency = C/B Volumetric efficiency (ηv): The engine output is limited by the maximum amount of air that can be taken in during the suction stroke, because only a certain amount of fuel can be burned effectively with a given quantity of air. Volumetric efficiency is an indication of the „breathing‟ ability of the engine and is defined as the ratio of the air actually induced at ambient conditions to the swept volume of the engine. In practice the engine does not induce a complete cylinder full of air on each stroke, and it is convenient to define volumetric efficiency as: ηv (%) = v (%) Mass of air consumed -------------------------------------------------------------------------mass of flow of air to fill swept volume at atmospheric conditions AirFlow ( Kg / Hr) 100 / 4 D L(m ) N ( RPM ) / n NoofCyl AirDen( Kg / m 3 ) 60 2 3 Where n= 1 for 2 stroke engine and n= 2 for 4 stroke engine. Air flow: For air consumption measurement air box with orifice is used. AitFlow ( Kg / Hr) Cd / 4 D 2 2 g hwater Wden / Aden Aden 3600 Where Cd = Coefficient of discharge of orifice D = Orifice diameter in m g = Acceleration due to gravity (m/s2) = 9.81 m/s2 h = Differential head across orifice (m of water) Wden = Water density (kg/m3) =@1000 kg/m3 Wair = Air density at working condition (kg/m3) = p/RT Where p= Atmospheric pressure in kgf/m2 (1 Standard atm. = 1.0332X104 kgf/m2) R= Gas constant = 29.27 kgf.m/kg0k T= Atmospheric temperature in 0k Specific fuel consumption (SFC): Brake specific fuel consumption and indicated specific fuel consumption, abbreviated BSFC and ISFC, are the fuel consumptions on the basis of Brake power and Indicated power respectively. Fuel-air (F/A) or air-fuel (A/F) ratio: The relative proportions of the fuel and air in the engine are very important from standpoint of combustion and efficiency of the engine. This is expressed either as the ratio of the mass of the fuel to that of the air or vice versa. Calorific value or Heating value or Heat of combustion: It is the energy released per unit quantity of the fuel, when the combustible is burned and the products of combustion are cooled back to the initial temperature of combustible mixture. The heating value so obtained is called the higher or gross calorific value of the fuel. The lower or net calorific value is the heat released when water in the products of combustion is not condensed and remains in the vapour form. Power and Mechanical efficiency: Power is defined as rate of doing work and equal to the product of force and linear velocity or the product of torque and 21-01-2014 Im231.docx Page 12 Apex Innovations angular velocity. Thus, the measurement of power involves the measurement of force (or torque) as well as speed. The power developed by an engine at the output shaft is called brake power and is given by Power = NT/60,000 in kW where T= torque in Nm = WR W = 9.81 * Net mass applied in kg. R= Radius in m N is speed in RPM Mean effective pressure and torque: Mean effective pressure is defined as a hypothetical pressure, which is thought to be acting on the piston throughout the power stroke. Power in kW = (Pm LAN/n 100)/60 in bar where Pm = mean effective pressure L = length of the stroke in m A = area of the piston in m2 N = Rotational speed of engine RPM n= number of revolutions required to complete one engine cycle n= 1 (for two stroke engine) n= 2 (for four stroke engine) Thus we can see that for a given engine the power output can be measured in terms of mean effective pressure. If the mean effective pressure is based on brake power it is called brake mean effective pressure (BMEP) and if based on indicated power it is called indicated mean effective pressure (IMEP). BMEP (bar ) BrakePower ( KW ) 60 L A ( N / n) NoOfCyl 100 IMEP (bar ) IndicatedP ower ( KW ) 60 L A ( N / n) NoOfCyl 100 Similarly, the friction means effective pressure (FMEP) can be defined as FMEP= IMEP – BMEP Basic measurements The basic measurements, which usually should be undertaken to evaluate the performance of an engine on almost all tests, are the following: 1 Measurement of speed Following different speed measuring devices are used for speed measurement. 1 Photoelectric/Inductive proximity pickup with speed indicator 2 Rotary encoder 2 Measurement of fuel consumption I) Volumetric method: The fuel consumed by an engine is measured by determining the volume flow of the fuel in a given time interval and multiplying it by the specific gravity of fuel. Generally a glass burette having graduations in ml is used for volume flow measurement. Time taken by the engine to consume this volume is measured by stopwatch. II) Gravimetric method: In this method the time to consume a given weight of the fuel is measured. Differential pressure transmitters working on hydrostatic head principles can used for fuel consumption measurement. 3 Measurement of air consumption Air box method: In IC engines, as the air flow is pulsating, for satisfactory measurement of air consumption an air box of suitable volume is fitted with orifice. 21-01-2014 Im231.docx Page 13 Apex Innovations The air box is used for damping out the pulsations. The differential pressure across the orifice is measured by manometer and pressure transmitter. 4 Measurement of brake power Measurement of BP involves determination of the torque and angular speed of the engine output shaft. This torque-measuring device is called a dynamometer. The dynamometers used are of following types: I) Rope brake dynamometer: It consists of a number of turns of rope wound around the rotating drum attached to the output shaft. One side of the rope is connected to a spring balance and the other to a loading device. The power is absorbed in friction between the rope and the drum. The drum therefore requires cooling. Brake power = ∏DN (W-S)/60,000 in kW where D is the brake drum diameter, W is the weight and S is the spring scale reading. II) Hydraulic dynamometer: Hydraulic dynamometer works on the principal of dissipating the power in fluid friction. It consists of an inner rotating member or impeller coupled to output shaft of the engine. This impeller rotates in a casing, due to the centrifugal force developed, tends to revolve with impeller, but is resisted by torque arm supporting the balance weight. The frictional forces between the impeller and the fluid are measured by the spring-balance fitted on the casing. Heat developed due to dissipation of power is carried away by a continuous supply of the working fluid usually water. The output (power absorbed) can be controlled by varying the quantity of water circulating in the vortex of the rotor and stator elements. This is achieved by a moving sluice gate in the dynamometer casing. III) Eddy current dynamometer: It consists of a stator on which are fitted a number of electromagnets and a rotor disc and coupled to the output shaft of the engine. When rotor rotates eddy currents are produced in the stator due to magnetic flux set up by the passage of field current in the electromagnets. These eddy currents oppose the rotor motion, thus loading the engine. These eddy currents are dissipated in producing heat so that this type of dynamometer needs cooling arrangement. A moment arm measures the torque. Regulating the current in electromagnets controls the load. Note: While using with variable speed engines sometimes in certain speed zone the dynamometer operating line are nearly parallel with engine operating lines which result in poor stability. 5 Measurement of indicated power There are two methods of finding the IHP of an engine. I) Indicator diagram: A dynamic pressure sensor (piezo sensor) is fitted in the cylinder head to sense combustion pressure. A rotary encoder is fitted on the engine shaft for crank angle signal. Both signals are simultaneously scanned by an engine indicator (electronic unit) and communicated to computer. The software in the computer draws pressure crank-angle and pressure volume plots and computes indicated power of the engine. Conversion of pressure crank-angle plot to pressure volume plot: 21-01-2014 Im231.docx Page 14 Apex Innovations The figure shows crank-slider mechanism. The piston pin position is given by x r cos l cos From figure r sin l sin and recalling cos 1 sin 2 2 x r cos l r 1 r l sin 2 The binomial theorem can be used to expand the square root term: x r cos l / r 1 1 (r / l ) 2 sin 2 1 8 (r / l ) 4 sin 4 ... 2 ….1 The powers of sin can be expressed as equivalent multiple angles: sin 2 1 / 2 1 / 2 cos 2 sin 4 3 / 8 1 / 2 cos 2 1 / 8 cos 4 …….2 Substituting the results from equation 2 in to equation 1 gives x r cos l / r 1 1 (r / l ) 2 1 / 2 1 / 2 cos 2 1 8 (r / l ) 4 3 / 8 1 / 2 cos 2 1 / 8 cos 4 ... 2 2 The geometry of the engine is such that r / l is invariably less than 0.1, in which case it is acceptable to neglect the r / l 4 terms, as inspection of above equation shows that these terms will be at least an order of magnitude smaller than r / l 2 terms. The approximate position of piston pin end is thus: x r cos l / r 1 1 (r / l ) 2 1 / 2 1 / 2 cos 2 2 Where r =crankshaft throw and l = connecting rod length. Calculate x using above equation; then (l r x) shall give distance traversed by piston from its top most position at any angle II) Morse test: It is applicable to multi-cylinder engines. The engine is run at desired speed and output is noted. Then combustion in one of the cylinders is stopped by short circuiting spark plug or by cutting off the fuel supply. Under this condition other cylinders “motor” this cylinder. The output is measured after adjusting load on the engine to keep speed constant at original value. The difference in output is measure of the indicated power of cut-out cylinder. Thus for each cylinder indicated power is obtained to find out total indicated power. a) When Cylinder no. 1 is in motoring: Output BP = Indicated power of Cylinder no. 2 + IP of cylinder no. 3 – Frictional power of cyl 1 – FP of cyl2 – FP of cyl 3 BP1 = IP2+IP3-FP1-FP2-FP3 BP1 = IP2+IP3-FP ------------I 21-01-2014 Im231.docx Page 15 Apex Innovations Where BP1 is Brake power when cyl no1 is cut off, FP is total frictional power for all 3 cylinders. Similarly BP2= IP1+IP3-FP--------------II and BP3 = IP1+IP2-FP--------------III b) When all working BP = IP1+IP2+IP3 – FP BP=IP1 + (IP2+IP3 – FP) BP = IP1 + BP1 (from eqn I) IP1 = BP - BP1 --------------------IV similarly IP2 = BP - BP2 --------------------V IP3 = BP - BP3 --------------------VI Add IP1, IP2 and IP3 to get total IP Then IP – BP = FP And mech eff = BP/IP VCR Engines The standard available engines (with fixed compression ratio) can be modified by providing additional variable combustion space. This is done by welding a long hollow sleeve with internal threads to the engine head. A threaded plug is inserted in the sleeve to vary the combustion chamber volume. With this method the compression ratio can be changed within designed range. Calculations Brake power (kw): 2NT 60 x1000 2N (WxR ) 60000 0.785 xRPMx (Wx9.81) xArmlength 60000 TxN BHP 75x60 BP Brake mean effective pressure (bar): BMEP BPx 60 / 4 xD xLx( N / n) xNoOfCylx100 2 n = 2 for 4 stroke n = 1 for 2 stroke Indicated power (kw) :From PV diagram ..m3 X scale (volume) 1cm = Y scale (pressure) 1cm = Area of PV diagram 21-01-2014 = ..bar ..cm2 Im231.docx Page 16 Apex Innovations workdone / cycle / cyl ( Nm) AreaofPVdi agram Xscalefact or Yscalefact or 100000 workdone / cycle / cyl ( N / n) NoOfCyl IP 60 1000 Indicated mean effective pressure (bar): IPx 60 / 4 xD xLx( N / n) xNoOfCylx100 IMEP 2 Frictional power (kw): Brake specific fuel consumption (Kg/kwh): FP IP BP FHP IHP BHP BHP IHP FHP BSFC Brake Thermal Efficiency (%): BThEff BP 3600 100 FuelFlowIn Kg / hr CalVal BThEff IThEff MechEff BHP OR 100 FuelHP Indicated Thermal Efficiency (%): IThEff IP 3600 100 FuelFlowIn Kg / hr CalVal IThEff BThEff 100 MechEff Mechanical Efficiency (%): MechEff FuelflowIn kg / hr BP BP 100 IP Air flow (Kg/hr): AirFlow Cd / 4 d 2 2 gh (Wden / Aden ) 3600 Aden Volumetric Efficiency (%): VolEff 21-01-2014 AirFlow 100 Theoretica lAirFlow AirFlow 100 / 4 D Stroke ( N / n) 60 NoOfCyl Aden 2 Im231.docx Page 17 Apex Innovations Air fuel ratio: A/ F AirFlow FuelFlow Heat Balance (KJ/h): a) HeatSuppli edbyFuel FuelFlow CalVal b) HeatEquivalentToUsefulWork BP 3600 HeatEquivalentToUsefulWork 100 HeatSuppli edByFuel C) HeatInJack etCoolingW ater F 3 C PW (T 2 T1) HeatEquivalentToUsefulWorkIn% HeatInJack etCoolingW aterIn% HeatInJack etCoolingW ater 100 HeatSuppli edByFuel d) Heat in Exhaust (Calculate CPex value): C P ex F 4 C PW (T 4 T 3) ..KJ / Kg 0 k ( F1 F 2) (T 5 T 6) Where, Cpex Specific heat of exhaust gas kJ/kg0K Cpw Specific heat of water kJ/kg0K F1 F2 F4 T3 T4 T5 T6 Fuel consumption Air consumption Calorimeter water flow Calorimeter water inlet temperature Calorimeter water outlet temperature Exhaust gas to calorimeter inlet temp. Exhaust gas from calorimeter outlet temp. kg/hr kg/hr kg/hr 0 K 0 K 0 K 0 K HeatInExha ust( KJ / h) ( F1 F 2) C P ex (T 5 Tamb) HeatInExha ust 100 HeatInExha ust % HeatSuppli edByFuel e) Heat to radiation and unaccounted (%) HeatSuppli edByFuel (100%) {( HeatEquivalentToUsefulWork (%) HeatInJack etCoolingW ater (%) HeatToExha ust (%)} 21-01-2014 Im231.docx Page 18 Apex Innovations Experiments 1 Study of engine performance (Manual mode) Object To study the performance of 3 cylinder, 4 stroke, Petrol engine connected to Eddy current dynamometer in manual mode Procedure Ensure cooling water circulation for Eddy current dynamometer, engine and calorimeter. Start the set up and run the engine at no load for 4-5 minutes. Gradually increase the load on the engine by rotating dynamometer loading unit nob. Wait for steady state (for @ 3 minutes) and collect the reading as per Observations provided in “Cal231” worksheet. Gradually decrease the load. Fill up the observations in “Cal231” worksheet to get the results and performance plots. 2 Study of Morse test Object To study Morse test Procedure Ensure cooling water circulation for dynamometer, engine and calorimeter. Start the set up and run the engine at no load for 4-5 minutes. Gradually increase the load on the engine from dynamometer loading unit. Increase the engine throttle to any desired position and simultaneously load the engine to obtain desired speed for which frictional power is to be calculated. Wait for few minutes till steady state is achieved. Note Engine speed and load. Cut off the fuel supply of cylinder no. 1 by pushing the push button "Cyl1" from Morse test panel. The engine speed shall decrease. Now decrease the load on dynamometer and bring back engine speed to the original. Wait for steady state (for @ 3 minutes) and collect the reading Repeat the same for "Cyl2" and "Cyl3". Fill up the readings is the Observations provided in “Cal231” worksheet in “Engine.xls”. Gradually decrease the load and throttle and Stop the engine. 21-01-2014 Im231.docx Page 19 Apex Innovations Components Rotameter (PG series) Rotameter works on the principle of variable area. Float is free to move up & down in a tapered measuring glass tube. Upward flow causes the float to take up a position in which the buoyancy forces and the weight are balanced. The vertical position of the float as indicated by scale is a measurement of the instantaneous flow rate. Technical specifications Model Make Pvt. Ltd. Flow Rate Max. Packing/Gaskets Measuring tube Float Cover Accuracy Range ability Scale length Max. Temp. Connection PG-1 to 21 Eureka Industrial Equipments 4000 to 40000 Lph Neoprene Borosilicate glass 316SS Glass +/-2% full flow 10:1 175-200mm. 2000C Flanged and Threaded, Vertical Principle of operation The rotameter valves must be opened slowly and carefully to adjust the desired flow rate. A sudden jumping of the float, which may cause damage to the measuring tube, must be avoided. Fig.1 Edge The upper edge of the float as shown in fig. 1 indicates the rate of flow. For alignment a line marked R.P. is provided on the scale which should coincide with the red line provided on measuring tube at the bottom. Maintenance When the measuring tube and float become dirty it is necessary to remove the tube and clean it with a soft brush, trichloroethylene or compressed air. Dismantling of the measuring tube Shut off the flow. Remove the front and rear covers. Unscrew the gland adjusting screws, and push the gland upwards incase of bottom gland and downwards incase of top gland. Then remove the glass by turning it to and fro. Care should be taken, not to drop down the glands. Float or float retainers. The indicating edge of the float should not be damaged. 21-01-2014 Im231.docx Page 20 Apex Innovations Fitting of the measuring tube Normally the old gland packing is replaced by new ones while fitting back the measuring tube. Put the glands first in their position and then put the packing on the tube. Insert the tube in its place. Push the glands downwards and upwards respectively and fix them with the gland adjusting screws. Tighten the gland adjusting screws evenly till the gap between the gland and the bottom plate is approximately 1mm. In case, after putting the loflometer into operation, still there is leakage, then tighten the gland adjusting screw till the leakage stops. Fix the scale, considering the remark given in the test report. Fix the front and rear covers. Troubleshooting Problem Leakage on glands Showing high/low flow rate than expected Showing correct reading initially but starts showing high reading after few days Showing correct reading initially but starts showing high reading after some months. Fluctuation of float Frequent breakage of glass tube Check Replace gland packing Consult manufacturers Replace float Incase of gases, check also leakage Clean the rotameter by suitable solvent or soft brush Maintain operating pressure as mentioned in test report. Use loflometer to accommodate correct flow rate. Maintain operating pressure below pressure rating of the tube. Check piping layout. Manufacturer’s address If you need any additional details, spares or service support for this unit you may directly communicate to the manufacturer / Dealer / Indian Supplier. Eureka Industrial Equipments Pvt. Ltd. 17/20, Royal Chambers, Paud Road, Pune – 411 038. Email: [email protected] 21-01-2014 Im231.docx Page 21 Apex Innovations Load cell Introduction Load cell are suitable use for static & dynamic weighing, bin/hopper weighing, force measurement, scales and electro-mechanical conversion kit. Constructed body of special high alloy steel. Approved for group I, IIA, IIB, & IIC applications and meets temperature class T4. Technical specifications Model Type Capacity Mounting thread Full scale output (mV/V) Tolerance on output (FSO) Zero balance (FSO) Non-linearity (FSO) Hysteresis (FSO) Non-repeatability Creep (FSO) in 30 min Operating temperature range Rated excitation Maximum excitation Bridge resistance Insulation resistance Span / 0C (of load) Zero / 0C (of FSO) Combined error (FSO) Safe overload (FSO) Ultimate overload (FSO) Protection class Overall dimensions Weight Manufacturer’s address Make Sensortronics 60001 „S‟ Beam, Universal 0 – 50Kg M10 x 1.25mm 3.00 +/-0.25% +/-0.1mV/V <+/-0.025% <+/-0.020% <+/-0.010% <+/-0.020% -200C to +700C 10V AC/DC 15V AC/DC 350 Ohms (Nominal) >1000 Meg ohm @ 50VDC +/-0.001% +/-0.002% <+/-0.025% 150% 300% IP 67 51 L x 20 W x 76 H mm 380 gm If you need any additional details, spares or service support for this unit you may directly communicate to the manufacturer / Dealer / Indian Supplier. Sensortronics Sanmar Ltd. 38/2A, Old Mahabalipuram Road, Perungudi, Chennai – 600 096. E-mail: [email protected] 21-01-2014 Im231.docx Page 22 Apex Innovations RPM indicator with sensor 21-01-2014 Im231.docx Page 23 Apex Innovations Load indicator 21-01-2014 Im231.docx Page 24 Apex Innovations 21-01-2014 Im231.docx Page 25 Apex Innovations 21-01-2014 Im231.docx Page 26
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