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US 4,685,072 AGranted
Steam generator on-line efficiency monitor
AssigneeThe Babcock & Wilcox Company
InventorsRalph K. Johnson, Azmi Kaya, Marion A. Keyes, IV, William H. Moss
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Abstract
A system for the automatic and continuous determination of the efficiency of a fossil fuel-fired vapor generator for utilization by an automatic load control (88) to control the distribution of the system load among a plurality of generators, wherein various heat losses from various combustion sources are separately determined, the individual losses summed (80) and subtracted (86) from 100 percent to obtain a measure of the vapor generator efficiency.
Claims7
A system for automatically and continuously determining the efficiency of a combustion process in a fossil-fuel fired vapor generator for utilization by an automatic load control system that controls the distribution of a system load among a plurality of vapor generators, comprising:
- a first function generator, connected to an oxygen transducer for sensing the level of excess air in the flue gas, for generating a first signal indicative of the total air supplied for combustion in percent by weight;
- a second function generator, connected to a combustibles transducer for sensing the level of combustibles in the flue gas, for generating a second signal indicative of the percent combustibles present in the flue gas;
- means for correcting the first signal, connected to said first and second function generators, when the oxygen transducer is of a type that operates at a temperature level sufficient to cause the unburned combustibles to react with the oxygen present in the flue gas;
- an ambient air temperature transducer for generating a third signal indicatve of the temperature of the ambient air supplied to the vapor generator for combustion;
- a flue gas exit temperature transducer for generating a fourth signal indicative of the temperature of the flue gas exiting from the vapor generator;
- means for generating a fifth signal indicative of the temperature difference between the flue gas exiting from the vapor generator and the ambient air supplied to the vapor generator;
- means for generating a sixth signal indicative of the specific heat of the dry flue gas;
- means for generating a ninth signal, indicative of the pounds of dry exit flue gas per pound of fuel, from said first and second signals, a seventh signal indicative of the required theoretical air for combustion, and an eighth signal indicative of the weight of combustibles in a pound of fuel;
- and
- means for generating a tenth signal, indicative of the heat loss in dry flue gas, from the product of said fifth, and sixth and ninth signals.
7 more elements
A method for the automatic and continuous determination of a vapor generator efficiency for utilization by an automatic load control comprising the steps of:
- generating a first signal proportional to the pounds of dry exit flue gas per pound of fuel;
- generating a second signal corresponding to the temperature difference between the sensed exit flue gas and the sensed air supplied combustion;
- generating a third signal proportional to the specific heat of the dry exit flue gases;
- generating a fourth signal proportional to the product of the first, second, and third signals and to the heat loss in the dry flue gas in BTU per pound of fuel;
- generating a fifth signal proportional to the pounds of combustibles in the exit flue gas per pound of fuel;
- generating a sixth signal proportional to the heat of combustion of said combustibles;
- generating a seventh signal proportional to the product of said fifth and sixth signals and to the heat loss due to combustibles in the exit flue gas in BTU per pound of fuel;
- generating an eighth signal proportional to the pounds of moisture in the air supplied for combustion per pound of fuel;
- generating a ninth signal proportional to the pounds of moisture in the fuel per pound of fuel;
- generating a tenth signal proportional to the sum of said eighth and ninth signals;
- generating an eleventh signal proportional to the specific heat of water vapor;
- generating a twelfth signal proportional to the product of said second and eleventh signals;
- generating a thirteenth signal proportional to the product of said tenth and twelfth signals and to the heat loss due to moisture in the fuel and air supplied combustion per pound of fuel;
- generating a fourteenth signal proportional to the latent heat of vaporization of the water in the fuel;
- generating a fifteenth signal proportional to the product of the ninth and fourteenth signals and to the latent heat of vaporization of the water in the fuel;
- generating a sixteenth signal proportional to the rate of vapor flow from the generator;
- generating a seventeenth signal varying in inverse non-linear relationship to the magnitude of said sixteenth signal and to the heat loss in percent due to heat radiation from the vapor generator;
- generating an eighteenth signal proportional to the loss due to unburned carbon in the fuel ash in BTU per pound of fuel;
- generating a nineteenth signal proportional to the heat loss in percent due to unaccounted for losses;
- generating a twentieth signal proportional to tbe sum of the fourth, seventh, thirteenth, fifteenth, and eighteenth signals;
- generating a twenty-first signal proportional to the higher heating value of fuel;
- generating a twenty-second signal proportional to the twentieth signal divided by the twenty-first signal;
- generating a twenty-third signal proportional to the sum of the seventeenth, nineteenth, and twenty-second signals and to the total of the said heat losses in percent;
- generating a twenty-forth signal proportional to 100 percent efficiency of the vapor generator;
- and
- generating a twenty-fifth signal proportional to difference between said twenty-forth signal and twenty-third signals and to the vapor generator efficiency.
23 more elements
Dependencies are inferred from the claim text.