Device for controlling the combustion process in a power station furnace system

Abstract

Device for controlling combustion process in power station furnace system, having burners (1) in combustion chamber. The combustion air is supplied via annular gap (3) surrounding burners which may influence quantity of combustion air flowing through the annular gap (3). Quantity of fuel supplied to burner (1) is recorded, and quantity of combustion air flowing through annular gap (3) is determined, for which two formed sensor rods (11, 12), arranged in the annular gap (3.1), successively and in parallel, preferably transversely to the longitudinal axis (4) of the annular gap and in the flow direction (7) of the combustion air flow, the sensor rods (11, 12) allow part of the combustion air to flow past the first sensor rod (12) in the flow direction (7) of the combustion air flow and also flows past the second sensor rod (11) in the flow direction (7) of the combustion air flow.

1 . A device for controlling the combustion process in a power station furnace system, comprising
 a plurality of burners ( 1 ) arranged in a wall of a combustion chamber, with combustion air is being supplied via one or more annular gaps surrounding the burner ( 1 ) and with the burner ( 1 ) comprising an arrangement for influencing the quantity of combustion air flowing through the annular gaps ( 3 ) into the combustion chamber, having at least a detector for detecting the quantity of fuel supplied to a burner ( 1 ) and an arrangement for determining the quantity of combustion air fuel flowing through the or the annular gaps ( 3 ), wherein the device generates control signals to influence the quantity of combustion air flowing through each annular gap ( 3 ),   wherein   the arrangement for determining the quantity of combustion air flowing through an annular gap ( 3 ,  3 . 1 ) having at least two sensor rods ( 10 ,  11 ) arranged in the annular gap ( 3 ,  3 . 1 ) sequentially in the flow direction ( 7 ) of the combustion air flow transverse to the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ) or at an angle α with respect to the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ) with about 30°≤α≤90° and parallel with a spacing a from each other, forming a corresponding pair,   wherein the sensor rods ( 10 ,  11 ) are composed of an electrically conductive material and electrically insulated from the walls ( 1 ,  2 ) that form the annular gap ( 3 ,  3 . 1 ),   wherein the shape of the sensor rods ( 10 ,  11 ) is adapted to the curvature of the annular gap ( 3 ,  3 . 1 ) and the sensor rods ( 10 ,  11 ) have a length l of l>20 mm, and   wherein the sensor rods ( 10 ,  11 ) are electrically connected to a correlation measuring device ( 13 ) which is used to determine the flow velocity (v) of the combustion air flow orthogonal to the longitudinal direction of the sensor rods ( 10 ,  11 ) by evaluating the electrical signals generated by the effect of electrically charged particles transported in the combustion air flow sensor rods ( 10 ,  11 ) and moving past the sensor rods ( 10 ,  11 ),   wherein in the event that the sensor rods ( 10 ,  11 ) are not arranged transversely to the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ), a component (v 2 ) of the flow velocity (v) of the combustion air flow in the direction of the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ) is calculated and, based on the component (v 2 ), the flow velocity (v) of the combustion air flow in the direction of the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ) is calculated, and the quantity of combustion air flowing through the annular gap ( 3 ,  3 . 1 ) is determined based on the geometric dimensions of the cross-sectional area of the annular gap ( 3 ,  3 . 1 ).   
     
     
         2 . The device according to  claim 1 ,
 wherein the sensor rods ( 10 ,  11 ) forming a corresponding pair are each arranged in the annular gap ( 3 ,  3 . 1 ) from the two walls ( 1 ,  2 ) forming in the annular gap ( 3 ,  3 . 1 ) with a respective constant spacing c, d, which is constant over the length of each sensor rod ( 10 ,  11 ).   
     
     
         3 . The device according to  claims 1 , wherein
 when an air guiding device ( 6 ) for generating a swirl flow of the combustion air flow is arranged, the sensor rods ( 10 ,  11 ) are arranged in the annular gap ( 3 ,  3 . 1 ) in the flow direction ( 7 ) of the combustion air flow downstream of the air guiding device ( 6 ).   
     
     
         4 . The device according to  claim 3 , wherein the sensor rods ( 10 ,  11 ) forming a corresponding pair are arranged in parallel but displaced relative to one another, such that at least a portion of the combustion air flowing past the first sensor rod ( 10 ) of the corresponding pair in the flow direction ( 7 ) of the combustion air flow also flows past the second sensor rod ( 11 ) of the corresponding pair in the flow direction ( 7 ) of the combustion air flow. 
     
     
         5 . The device according to  claim 3 ,
 wherein   two pairs of corresponding sensor rods ( 10 . 1 ,  11 . 1  and  10 . 2 ,  11 . 2 ) are arranged in the annular gap ( 3 ,  3 . 1 ), wherein the two pairs of corresponding sensor rods ( 10 . 1 ,  11 . 1  and  10 . 2 ,  11  . 2 ) are arranged at a different angle α with respect to the longitudinal axis ( 4 ) of the annular gap ( 3 ,  3 . 1 ).   
     
     
         6 . The device according to  claims 1 ,
 wherein   the sensor rods ( 10 ,  11 ) are constructed as one of a round rod having a diameter D with 1 mm≤D≤20 mm, or as a square rod having an edge length e in the direction of the width b of the annular gap with 1 mm≤e≤20 mm.   
     
     
         7 . The device according to  claims 1 ,
 wherein   sensor rods ( 10 ,  11 ) are formed by foil strips made of an electrically conductive material which are glued onto one of the two walls ( 1 ,  2 ) forming the annular gap ( 3 ,  3 . 1 ) and insulated with respect to the wall ( 1 ,  2 ).   
     
     
         8 . The device according to  claims 1 ,
 wherein characterized in that the sensor rods ( 10 ,  11 ) are segmented in the longitudinal direction, wherein the segments of the sensor rods ( 10 ,  11 ) are one of electrically connected to one another in series and the series connections of the sensor rods ( 10 ,  11 ) are electrically connected to a correlation measuring device ( 13 ), or the segments of the sensor rods ( 10 ,  11 ) are electrically connected to a correlation measuring device ( 13 ).   
     
     
         9 . The device according to  claim 1 , wherein the length I of the sensor rods ( 10 ,  11 ) is greater than 200 mm.