SU1093877A1 - Method of checking fuel incomplete combustion - Google Patents

Abstract

THE METHOD OF CONTROL CHEMICAL UNDERLETE OF POGZHV by measuring the signal proportional to the total thermal effect of oxidation of combustible components Nd and CO, by means of a sensor in the forced flow of the sample, which is measured through a diffusion membrane, and measured through an increase in its accuracy, a part of the analyzed sample is passed through the diffusion membrane and passed through the diffusion membrane and measured through the diffusion membrane and passed through the diffusion membrane and passed through a diffusion membrane and a part of the analyzed sample passed through the diffusion membrane and passed through the diffusion membrane. proportional to the total thermal effect of the oxidation reaction of the combustible components CO and Hj, by the sensor in the diffusion flow, is subtracted from the sensor signal located in the receiver the flow signal, the signal of the sensor located in the diffusion flow, and the resulting difference of signals judge the concentration of products of chemical underburning fuel. CO 00 00 4J

Description

1 The invention relates to the control of combustion and can be used in the systems of automatic control and regulation of the combustion process of energy steam generators, industrial boilers, furnaces and other fuel-using units. The closest to the invention is a method of controlling the chemical underburning of fuel by measuring a signal proportional to the total thermal effect of the reaction. Oxidation of combustible components Hg and CO by a sensor in the forced flow of the analyzed sample lj. The disadvantage of this method is low reliability of the control of chemical underburning of fuel in the presence of hydrogen Hi and carbon monoxide CO in the sample being analyzed. In this case, the output signal of the measuring bridge circuit for this monitoring method can be written as. , C, K2C2 (1) where C, and Ci are concentrations of hydrogen Hj, respectively. and V carbon monoxide; K, and Kg - sensor transmission coefficients, respectively, for H and CO. Since the coefficients K and K are not equal, and K, K, due to the higher calorific value of hydrogen, it is impossible to obtain a unique dependence of the sensor signal on the sum of combustible CO + Ng. in waste gases. The purpose of the invention is to improve the accuracy of control of chemical underburning of fuel. The goal is achieved by the method of controlling chemical underburning of fuel by measuring the signal proportional to the total thermal effect of the oxidation of combustible components H2 and CO, a sensor in a forced flow of the sample being analyzed, a part of the analyzed sample is passed through a diffusion membrane, measuring the signal proportional to the total the thermal effect of the oxidation of the combustible components CO and Hg, by a sensor in the diffusional flow, is subtracted from the sensor signal located in the forced sweat OC, the signal of the sensor located in the diffusion flow and on the obtained difference of the signals 77 judges the concentration of products of the chemical underburning of fuel. FIG. 1 shows a diagram of a device that implements a method for controlling chemical underburning of fuel; in fig. 2 - calibration characteristics of the sensor located in the forced flow; in fig. 3 -. calibration characteristics of the sensor located in the diffusion flow; in fig. 4 - calibration characteristic of the device that implements the method of controlling the chemical underburning of fuel. The device for monitoring the chemical underburning of fuel (Fig. 1) contains a sensor 1 located in the forced flow, and a sensor 2 located in the diffusion flow, the adjacent arms of the bridge circuits which include identical in their geometrical and electro-thermal parameters working 3 and comparative 4 sensitive elements and the same size shoulders 5 ratios. To correct the zero, the bridges contain zero-equalizers 6. The bridges are powered from a stabilized electric source 7. The operating sensing elements are platinum thermal resistors, fixed in a layer of solid carrier of active alumina and heated by an electric current. The surface of the carrier is coated with a fine low-temperature catalyst, for example, platinum-palladium. Comparative elements are made similar to the working ones, but do not contain a catalytic coating. Sensing elements 3 and 4 of sensor 1 are installed in the sample receiver 8 directly in the forced flow of the sample being analyzed, and sensitive elements 3 and 4 of sensor 2 are installed in chamber 9, which is separated from the main flow by a diffusion membrane 10. The membrane 10 can be made of a thin film permeable to carbon monoxide and hydrogen, or to a porous material, for example, from nickel-based metal-ceramic granules sintered under pressure, or from a multi-explosion network. - Bridge measuring circuits of sensors 1 and 2 are included in the opposite direction, i.e. provides the subtraction of their signals. The difference of the signals is measured by the indicating device 11, and the part of the signal of the bridge of the sensor 2, defined by the voltage divider 12, is subtracted from the signal of the bridge of the sensor 1. In the presence of chemical underburning, oxidation of the combustible components CO and Ng takes place at the working sensing elements of the 3 bridges of sensors 1 and 2. The useful signal of the sensor 1 - Id depends on the thermal effect and the complete oxidation of the combustible component on it, moreover, due to the difference in physical and chemical the properties of the H and CO coefficients. the transmissions, respectively, Kj — right 13 and KI right 14 (FIG. 2) are different, and K, K FIG. Figure 3 shows the calibration characteristics of sensor 2 on Na - Direct 15 and CO - Direct 16 in the diffusion flow of the analyzed sample of combustion products. Due to the difference in diffusion coefficients Hj and CO, the transmission coefficients in the diffusion flux. K and K differ from the corresponding coefficients in the inductive flux K | and Kg, and their ratios are not equal. v; , kCx The output signal of the sensor 2 Itz K / S, + KgSg. , (3) The differential signal of the device paradise is IGGrid, (: to –jbKOc, –– (–jbKx) a2, (where ft is the fraction of the signal from the sensor located in the diffusion flow, subtracted from the sensor signal located in the forced current). (2) 774 From equation (4) it is obvious that by choosing the value of j3 from the condition, l, K-1, from which we obtain the equation (: s, + - C4y in which the proportionality coefficient tC- | /, -. Jbk,) C2 -y 2 The calibration characteristic of the device 17 is shown in Fig. 4. The signal measured by the measuring device 11 is proportional to the total concentration of H and CO. The fuel burner is performed as follows: During the calibration process, the calibration characteristics of sensors 1 and 2 and the value A, which is set with the help of divider 12, are determined. Thus, predictor 11 shows the magnitude of chemical underburning proportional to the content of Hj and CO. Use The proposed method of controlling the chemical underburning of fuel makes it possible to increase the control accuracy and to receive a signal on the indicating device proportional to the content of NdI CO, which in turn allows an increase in The efficiency of quality control of fuel combustion and reduce emissions of Himnedo products to the atmosphere.

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Claims (1)

METHOD FOR CONTROL OF CHEMICAL underburning The signal FUEL by measuring, Nala proportional to the total thermal effect of the oxidation reaction of combustible components H _r th CO sensor in a forced stream analysis sample, characterized in that, in order to increase its accuracy, some of the analysis sample is passed through the diffusion membrane measure the signal proportional to the total thermal effect of the oxidation reaction of the combustible components CO and H ^ by the sensor in the diffusion flow, subtract from the signal of the sensor located in the forced Yelnia stream signal sensor arranged in the diffusion flow, and the resulting difference signal is judged on the chemical concentration of unburnt fuel.