Document NeVbnN9OvEbaBgd3w3px25zmV

HEATINC VENTILATING AIR CONDITIONING GUIDE 1944 The correct fuel burning rate can be determined directly from the several charts for oil or gas burning installations, as these customarily operate on a strictly intermittent basis. These fuel burning devices usually introduce the fuel at a single fixed rate during the on periods and this rate should be sufficient to carry the gross load. In the case of coal stokers, which are usually capable of variable rates of firing, it is desirable to operate at as low a rate as weather conditions will permit, but the maxi mum firing rate of the stoker should be sufficient to carry the gross load. This rate may be determined by the same method as used for oil or gas. REFERENCES Performance Expectancy of Domestic Underfeed Stokers for Anthracite, by Allen J. Johnson (Transactions, A.I.M.E., Coal Division, Vol. 119, 1936). The Relation of the Size of Bituminous Coals to Their Performance on Small Under feed Stokers--Burning Tests on Four Typical Coals, by R. A. Sherman, E. R. Kaiser and H. R. Limbacher, Technical Report No. 1, Bituminous Coal Research, Inc. (July, 1937) Part it. Handbook of Oil Burning, by Harry F. Tapp. A Study of the Oil Burner as Applied to. Domestic Heating, by Arthur H. Senner (Technical Bulletin 109, U. S. Department of Agriculture). Progress in Domestic Oil Heating, by Rene J. Bender (Mechanical Engineering, October, 1942). A.S.H.V.E. Research Report No. 907--Study of Performance Characteristics of Oil Burners and Low Pressure Heating Boilers, by L. E. Seeley and E. J..Tavanlar (A.S.H.V.E. Transactions, Vol. 37, 1931, p. 517). A.S.H.V.E. Research Report No. 925--A Study of Intermittent Operation of Oil Burners, by L. E. Seeley and J. H. Powers (A.S.H.V.E. Transactions, Vol. 38, 1932, p. 317). t ^ Supply and Its Effect on Performance of Oil Burners and Heating Boilers, by L. E. Seeley, J. H. Powers and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 39,1933, n v?vi .* . Study of Fuel Burning Rates and Power Requirements of Oil Burners in Relation to Excess Air, by L. E. Seeley and E. J. Tavanlar (A.S.H.V.E. Transactions, Vol. 40, 1934, p. 319). Oil Burning in Residences, by D. W. Nelson (A.S.H.V.E. 'Transactions, Vol. 41 . 1935, p. 355). . A Study of Oil-Fired Heating Boilers, by R. C. Cross and W. R. Lyman (Heating and Ventilating, October, 1931). Combustion, American Gas Association. Comfort Heating, American Gas Association. Approval Requirements of Central House Heating Gas Appliances, American Gas Association. A Method for Determining Fuel Burning Rates in Heating Boilers Fired by Auto matic Devices, by R. C. Cross (Heating and Ventilating, January, 1932). Heat Losses and Efficiencies of Fuels in Residential Heating, by R. A. Sherman and R. C. Cross (A.S.H.V.E. Transactions, Vol. 43, 1937, p. 185). 222 CHAPTER 11 3timating. uei (Consumption Fuel Consumption Records, Calculated Heat Loss Estimation Method, Degree-Day Method, Unit Fuel Consumption per Degree-Day, Degree-Day as an Operating Unit, Maximum Demands and Load Factors MANY methods are in use for estimating in advance of actual oper ation the anticipated heat or fuel consumption of heating plants over long or short periods. With suitable modification in procedure these same general methods are frequently useful in checking the degree of effectiveness with which heat or fuel is utilized during plant operation. In applying any of these estimating methods to the consumption of a particular building plant it should be noted that (a) reliable records of past heat or fuel consumptions of the building under consideration will usually produce more trustworthy estimates of future consumptions than will any data obtained by averages or from other similar buildings; (b) where no past records exist useful data can sometimes be obtained from records of similar buildings with similar plants in the same locality; (c) records of consumption, which are averages from many types of plants in many types of buildings in various localities, can produce no better than an average estimate which may be far from accurate; (d) estimates based on computed heat losses without the benefit of operating data are wholly dependent on how well the computation represents the actual facts. Estimates based on computed heat losses alone are frequently the only ones possible to obtain, especially where new equipment is put into unusual buildings and there is a scarcity of records and an absence of experience data. Such estimates also have to be made where direct information is not obtainable as, for example, if a survey is being made without the assistance or knowledge of the building operator and thus without information as to the actual consumption. Estimates of this kind are also useful in some cases where a relative standard of performance is desired to serve as a base of comparisons in a campaign of fuel utili zation. In interpreting and evaluating heat or fuel consumption estimates as well as in their preparation, it is well to realize that any estimating method used will produce a more reliable result over a long period operation than over a short period. Nearly all of the methods in common use.will give trustworthy results over a full annual heating season, and in some cases such estimates will prove consistent within themselves for monthly periods. As the period of the estimate is shortened there is more chance that some 223