CHAPTER XLIII PRESENT STATUS OF OIL BURNING POWER PLANT DESIGN The present shortage of hydro-electric power on the Pacific Coast has created an unusual situation in that the demand for power is so great that steam plants intended originally to act merely as standby installations and to assist the hydro-electric systems in case of trouble are now being operated at full capacity and carrying a large proportion of the total load. Other steam plants are being planned, and those already under way are being rushed to completion so as to tide over the emergency fast becoming acute. Fuel.-California oil is the fuel that is used almost exclusively, along the Western Coast. However, unless its production is greatly increased, in the next few years Mexican oil will be introduced into California as it has been in Arizona, Texas and the Atlantic Coast. Mexican oil is generally much heavier, dirtier and more viscous than California oil. Oil in the Panuco FIG. 232.-Graphical display of petroleum production. field runs in gravity about 12° Baumé and is so viscous that it cannot be unloaded from a car without being heated and must be kept up to a temperature of 120°F. (50°C.) in the pipes in order to keep it flowing. It is therefore necessary to use large pipes, covered on the outside and containing internal heating pipes through which steam or hot water is passed. Mexican oil usually contains a large proportion of silt, and it is necessary to provide strainers at both the suction and discharge of pumps as well as at the burners. To burn properly it must be heated up to 190°F. (90°C.) and in some cases even as high as 250°F. (110°C.) Natural gas is now being used in Bakersfield and in Los Angeles. This is the only available fuel that is superior to fuel oil. It has all the advantages of oil, and in addition does not require atomizers or bulky storage tanks if it is piped direct from the wells. Coal is used quite extensively in the Pacific Northwest, both in pulverized form and stoker-fired. In California, however, FIG. 234.-Comparison of coal and fuel oil production. there is no coal marketed except for domestic purposes. If oil continues to advance in price, the question of the available supply of coal will become of paramount importance. The most promising source appears to be the Alaskan coal fields, which are known to be very extensive and to contain coal of excellent quality. Vast developments must be made, however, in the way of transport and docking facilities before Alaskan coal becomes available in quantities sufficient to represent a factor of importance in connection with power developments. The design of a coal-burning plant differs in many respects from that of an oil-burning plant. Boilers must be set higher for coal than for oil so as to provide room for mechanical stokers or to provide ample combustion space for powdered fuel. A basement under the boilers is required for handling ashes. The building must be high enough to allow for coal bunkers and conveyors above the boilers, larger smokestacks are necessary, and forced-draft apparatus is usually required. In most cases, therefore, it would be impracticable to change over existing oilburning plants to coal-burning plants, although, on the other hand, it is an easy matter to change a coal-burning plant to an oil-burning one. In some cases oil-burning plants have been specially designed with a view to converting them to coal-burning at a future date. However, since it is impossible to anticipate the rapid changes that occur in engineering practice, the extra expense involved in thus attempting to design for the future is hardly warranted. Another fuel used quite extensively in the Northwest is the refuse from sawmills, known as hog fuel. This is an extremely cheap fuel if used close to the mill. Owing to its bulk, however, it is difficult to transport, and its field of usefulness is therefore limited. LOCATION OF STEAM-ELECTRIC POWER PLANTS Economy of design in the vast hydro-electric transmission lines of the West, in which steam-electric generation serves as an auxiliary, necessitates the location of the steam-electric plant as near to the large industrial centers as possible. This reduces to a minimum the distance through which the steam-generated power must be transmitted, thus avoiding the necessity of burning extra fuel to make up for transmission losses. The exact location within the industrial center depends mainly on the four following factors: (a) An adequate supply of water for condensing purposes; (b) access to deep water, to enable oil to be delivered by barge; (c) railway facilities for the delivery of machinery and possible delivery of fuel; (d) proximity of the transmission |