78 CHAPTER IV EXPERIMENTAL WORK 4.1 INTRODUCTION The details of the experimental set up are presented in this chapter. The information about the engine, components, instrumentation and controls used in test engine are described. 4.2 EXPERIMENTAL SET-UP The various components of experimental set up are described below. Fig.4.1 shows line diagram & Fig.4.2 shows the photograph of the experimental set up. The important components of the system are (i) The engine (ii) Dynamometer (iii)smoke meter (iv) Exhaust gas analyzer 4.2.1 The Engine: The Engine chosen to carry out experimentation is a single cylinder, four stroke, vertical, water cooled, direct injection computerized Kirloskar make CI Engine. This engine can withstand higher pressures encountered and also is used extensively in agriculture and industrial sectors. Therefore this
79 engine is selected for carrying experiments. The specifications of the engine given in Appendix I. Fig. 4.3 and 4.4 show the actual photos of the C.I. Engine and its attachments. 4.2.2 Dynamometer: The engine has a DC electrical dynamometer to measure its output. The dynamometer is calibrated statistically before use. The dynamometer is reversible i.e., it works as monitoring as well as an absorbing device. Load is controlled by changing the field current. Eddy-Current Dynamometer's theory is based on Eddy-Current (Fleming's right hand law). The construction of eddy-current dynamometer has a notched disc (rotor) which is driven by a prime mover (such as engine, etc.) and magnetic poles (stators) are located outside with a gap. The coil which excites the magnetic pole is wound in circumferential direction. When current runs through exciting coil, a magnetic flux loop is formed around the exciting coil through stators and a rotor. The rotation of rotor produces density difference, then eddy-current goes to stator. The electromagnetic force is applied opposite to the rotational direction by the product of this eddy-current. 4.2.3 Smoke meter: Smoke measurement is made using an OPAX2000II/DX200P of Neptune Equipment Pvt. Ltd. Ahmedabad. The measurement is based on the principle of light absorption by particle. Photo electronic smoke detection is based on the principle of optical detection. It is also known as the "scattered" light principle. An alarm condition occurs when smoke particles
80 enter the light path and a part of the light is "scattered" by reflection and refraction onto a sensor. This type of detector is best for areas where dense smoke may occur, as in ductwork. The equipment allows test on a continuous mode, average and peak levels. The measured operating values are shown as three digital either in light absorption coefficient that is in ABS K units from 0.00 to 9.99 are in Bosch units (or) in percentage from 0% to 99.9%.The measurements are made in Bosch units at continuous mode. Fig.4.7 shows the actual photo of smoke meter attached to the engine at the exit. 4.2.4 Exhaust Gas Analyzer: All emissions like Carbon monoxide, Carbon dioxide,un-burnt Hydrocarbons, Nitrogen oxide and unused oxygen are found in 5 gas emission analyzer of model 5G -10, PLANET EQUIPMENT is used. In this cable one end is connected to the inlet of the analyzer and the other end is connected at the end of the exhaust gas outlet. Continuous charging of the analyzer is essential to work in an effective way.fig.4.5 and 4.6 show the actual photos of Exhaust Gas Analyzer attached to engine at the exit. The measuring method is based on the principle of light absorption in the infrared region, known as "non-dispersive infrared absorption" (NDIR). The broadband infrared radiation produced by the light source passes through a chamber filled with gas, generally methane or carbon dioxide. This gas absorbs radiation of a known wavelength and this absorption is a measure of the concentration of the gas. There is a narrow bandwidth optical filter at
81 the end of the chamber to remove all other wavelengths before it is measured with a pyro-electric detector. 4.3. Experimental Programme: The experiments are conducted for variable loads like 0.2, 1,2,3,4 and 5.2 KW at rated speed, with injection pressure of 210 bars and cooling water exit temperature at 65 0 C. Three blends of all types of vegetable oils such as 25%, 50%, 75% and 100% (neat oils) are used in this experimentation. The vegetable oils and their blends with diesel are heated externally to a required temperature as stated earlier before injecting into the test cylinder. The engine was sufficiently warmed up and stabilized before taking all the readings. All the observations recorded were replicated thrice to get a reasonable value. The performance parameters such as Brake Thermal Efficiency(ηB.Th.), Brake Specific Fuel Consumption(bsfc), Exhaust Gas Temperature(EGT) and Volumetric efficiency(ηvol.) Emission parameters such as Carbon Monoxide (CO), Carbon Dioxide (CO2), Un-burnt Hydro carbon (UHC) (UHC), Nitrogen Oxides (NOx) and Smoke are evaluated.these performance and emission parameters of oils are compared to those of pure diesel.
82 F2 Compu Control Panel F1 T2 PT T5 T4 Calorimete T6 EGA SM T3 N Dynamometer Engine Rota meters T1 Fig.4.1.Line diagram of Experimental setup Fig.4.2. Experimental setup with Instrumentation
83 Fig. 4.3. Experimental set up of computerized C.I. Engine Fig. 4.4. Experimental set up of computerized C.I. Engine with smoke meter
84 Fig. 4.5. Five gas emission analyzer
85 Fig. 4.6. Five gas analyzer with display
86 Fig. 4.7. Smoke meter