Centrales Diesel

Diesel Electric Power Plants
23.1. Introduction. 23.2. Field of Use. 23.3. Outline of Diesel Electric Plant. 23.4. Types of Engines used for Diesel Power Plants. 23.5. Thermodynamic Cycles and Cycle Analysis. 23.6. Different Systems of Diesel Power Plant. 23.7. Supercharging of Diesel Engines. 23.8. Performance of the Diesel Power Plant. 23.9. Plant Layout. 23.10. Advantages and Disadvantages ofDiesel Plant over Thermal Plants. 23.11. Present Trends in Diesel Research. 23.1. INTRODUCTION

Since the invention of diesel engine at the end of the nittenth century, this engine has found increasing applications either as continuous or as a peak source of electric power due to its excellent qualities in respect of economy of operation. Diesel electric plants in the range of 2 to 50 MWcapacity are used as central stations for small supply authorities and works and they are universally adapted to supplement hydro-electric or thermal stations where stand-by generating plants are essential for starting from cold and under emergency conditions. In many countries, the demand for diesel electric plants is increased for electric power generation because of difficulties experienced inconstruction of new hydraulic plants and enlargement of old hydro-plants. A long-term planning is required for the development of thermal and hydroplants which cannot keep the pace many times with the increased demand by the people and industries. The diesel units used for electric generation are more reliable and long-lived piece of equipment compared with other types of plants. In Denmark, a 15 MWunit was in existence as far back as the early 1900s. The 20 MW set of four engines is available in Belgium which was established long back. The present trend is to increase the unit capacity, and unit capacity of 40 to 100 MW is expected by the end of this century. In some countries like Iran, few power plants work with diesel engines to supply large network where prices of fuel are in favour ofadopting diesel-plants. With the rapid development of electric generation by other sources after independence made diesel plants to disappear from field as their generation cost was considerably high. Many small units in the range of 1 to 5 MW were used in India before independence to take the localised load as to supply electricity to small industrial units or district towns. The diesel plants aremore efficient than any other heat engines of comparable size. It is cheap in first cost. It can be started quickly and brought into the service. It can burn a fairly wide range of fuels. Its manufacturing periods are short and, therefore, a diesel station may be rapidly extended to keep pace with load growth by adding generating units of suitable sizes. With such a formidable list of merits to itscredit, it does not monopolise the power production market. Because, there are definitely some hurdles in the way of adopting these units for power generation as well as other power plants are in good competition with this unit. It is sometimes possible to generate power very cheaply where use can be made of existing civil engineering works such as navigation or irrigation canals by introducingmicro-hydro power plants, particularly low siphon units using bulb-propeller turbines. The thermal plants are favoured where cheap solid fuels or combustible waste products are cheaply available which can be burnt in boilers. The gas turbine power plants for continuous power generation are superior than diesel where fuel is very cheap, as at refinery or where load factors are very low. All theserivals to the diesel plant can be attractive where they are favoured by the right conditions. The diesel engine will provide the most economic means of generating electricity on small scale particularly where there is no convenient site for micro-hydro plants and cheap fuels are not available and load factors are considerably large. j In the Southern states of India, especially in Karnataka and...