A method and control system for controlling the thickness of garbage layer in a garbage incinerator

Abstract

The present application discloses a method and control system for controlling the thickness of a garbage layer in a garbage incinerator, which ensures the stability of incineration. The method comprises: measuring the thickness of the garbage layer on the drying grate and the combustion grate; performing closed-loop adjustment according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, converting the closed-loop output to obtain the standard speed of the pusher and the drying grate; performing closed-loop adjustment according to the deviation between the measured value and the set value of the thickness of the garbage layer on the drying grate, multiplying the closed-loop output by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate; performing closed-loop adjustment according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, multiplying the closed-loop output by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; performing speed control according to the standard speed of the pusher and the ember grate, and performing speed control according to the corrected standard speed of the drying grate and the combustion grate.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic combustion control, and more specifically to a method and a control system for controlling the thickness of a garbage layer in a garbage incinerator. Background Art

[0002] The ACC (Automatic combustion control) system of the waste incinerator is centered on the main steam flow control and the waste layer thickness control, and combines the furnace temperature control, the thermal burn rate minimization control, the oxygen content control, etc. to realize the all-round regulation of the automatic combustion of the waste incinerator.

[0003] Garbage layer thickness control is an important part of the ACC system. The so-called garbage layer thickness refers to the thickness of the garbage above the grate of the garbage incinerator during the combustion process of the garbage incinerator. Figure 1 As shown, the grate is arranged in three steps, and the upper, middle and lower steps are respectively called drying grate 1, combustion grate 2 and ember grate 3; the pusher 4 pushes the garbage put into the feeding port 5 onto the drying grate 1, and after the garbage is fully dried on the drying grate 1, it falls onto the combustion grate 2 through the continuous movement of the drying grate 1, and after the garbage is burned on the combustion grate 2, it falls onto the ember grate 3 through the continuous movement of the combustion grate 2, and after the garbage is completely burned and cooled on the ember grate 3, it falls into the slag outlet through the continuous movement of the ember grate 3.

[0004] In order to ensure the burning stability of the waste incinerator, the furnace temperature needs to be well controlled. The furnace temperature is mainly determined by the thickness of the waste layer on the combustion grate 2. The movement speed changes of the combustion grate 2, the pusher 4 and the drying grate 1 can change the thickness of the waste layer on the combustion grate 2 (when the thickness of the waste layer on the combustion grate 2 is too high, the thickness of the waste layer on the combustion grate 2 can be reduced by slowing down the movement speed of the drying grate 1 and the pusher 4 and speeding up the movement speed of the combustion grate 2; when the thickness of the waste layer on the combustion grate 2 is too low, the thickness of the waste layer on the combustion grate 2 can be increased by speeding up the movement speed of the drying grate 1 and the pusher 4 and slowing down the movement speed of the combustion grate 2). Based on this, the prior art has adopted the following waste layer thickness control scheme:

[0005] A grate standard speed S1 is predetermined as the standard speed of the burning grate 2 and the ember grate 3;

[0006] The thickness of the garbage layer on the combustion grate 2 is measured, and closed-loop regulation is performed according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate 2 and the set value. The output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate 2;

[0007] A closed-loop adjustment is performed according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate 2 and the set value, and the output of the closed-loop adjustment is converted as the standard speed of the pusher 4 and the drying grate 1;

[0008] The pusher 4, the drying grate 1 and the ember grate 3 are controlled to move according to their standard speeds, and the combustion grate 2 is controlled to move according to the corrected standard speed of the combustion grate 2.

[0009] Under the above-mentioned garbage layer thickness control scheme, if the garbage layer thickness on the drying grate 1 is within a reasonable range, the deviation between the garbage layer thickness formed on the combustion grate 2 and the set value is not large, so the adjustment range of the garbage layer thickness on the combustion grate 2 is not large, otherwise the adjustment range is larger; and in the case of a larger adjustment range, the furnace temperature is bound to fluctuate greatly. Summary of the invention

[0010] In view of this, the present invention provides a method and a control system for controlling the thickness of a garbage layer in a garbage incinerator to ensure the incineration stability.

[0011] A method for controlling the thickness of a garbage layer in a garbage incinerator, comprising:

[0012] Measure the thickness of the garbage layer on the drying grate and the combustion grate respectively;

[0013] According to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, a closed-loop adjustment is performed, and the output of the closed-loop adjustment is converted to obtain the standard speed of the pusher and the drying grate;

[0014] Closed-loop regulation is performed according to the deviation between the measured value of the thickness of the garbage layer on the drying grate and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate;

[0015] A closed-loop adjustment is performed according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, and the output of the closed-loop adjustment is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; wherein the standard speeds of the combustion grate and the ember grate are pre-calculated according to the basic parameters of the garbage incinerator;

[0016] The pusher and the ember grate are controlled to move respectively according to their standard speeds, and the drying grate and the burning grate are controlled to move respectively according to their corrected standard speeds.

[0017] Optionally, before controlling the movement of the pusher and the ember grate at their standard speeds, and controlling the movement of the drying grate and the burning grate at their corrected standard speeds, the method further includes: measuring the thickness of the garbage layer on the burning grate;

[0018] A closed-loop adjustment is performed according to the deviation between the measured value of the thickness of the garbage layer on the ember grate and the set value, and the output of the closed-loop adjustment is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the ember grate;

[0019] The method of controlling the movement of the pusher and the ember grate according to their standard speeds, and controlling the movement of the drying grate and the burning grate according to their revised standard speeds, can be replaced by: controlling the movement of the pusher according to their standard speed, and controlling the movement of the drying grate, the burning grate and the ember grate according to their revised standard speeds.

[0020] Optionally, measure the thickness of the waste layer on any section of the grate, including:

[0021] Use multiple differential pressure transmitters to measure the upper and lower pressure differences of the garbage layer at different positions of this grate, calculate the average value, and then convert it to obtain the corresponding garbage layer thickness.

[0022] Optionally, the method of using a plurality of differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of the grate in this section, calculating the average value thereof, and then converting the corresponding garbage layer thickness to obtain the corresponding garbage layer thickness includes:

[0023] A differential pressure transmitter is used to measure the upper and lower pressure difference of the garbage layer on the left half of this grate section, and another differential pressure transmitter is used to measure the upper and lower pressure difference of the garbage layer on the right half of this grate section. The two pressure differences are then averaged and converted to obtain the corresponding garbage layer thickness.

[0024] Optionally, the formula for calculating the standard speed of the burning and ember grate according to the basic parameters of the garbage incinerator is:

[0025] S1=V1*F1(x)

[0026] Wherein, V1=C2*FT / C1 / LHV / T;

[0027] V1 represents the required garbage volume, in m 3 ;

[0028] C1 represents boiler thermal efficiency, unit: %;

[0029] C2 represents the boiler steam enthalpy, unit KJ / kg;

[0030] FT represents the boiler steam volume setting value, unit is h / t;

[0031] LHV means the lower heating value of garbage, in KJ / kg;

[0032] T represents the specific gravity of garbage, unit: t / m 3 ;

[0033] F1(x) represents the inverse of the feed throat area, unit 1 / ㎡;

[0034] S1 represents the standard speed of the burning and embering grate, in m / h.

[0035] Optionally, the method for controlling the thickness of the garbage layer in a waste incinerator further includes: further performing deviation correction on the corrected standard speed of any grate in combination with other influencing factors, wherein the other factors include furnace temperature.

[0036] A garbage layer thickness control system for a garbage incinerator, comprising:

[0037] Measuring unit, used to measure the thickness of the garbage layer on the drying grate and the combustion grate respectively;

[0038] A control unit is used to perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and the output of the closed-loop regulation is converted to obtain the standard speed of the pusher and the drying grate; perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the drying grate, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate; perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; wherein the standard speeds of the combustion grate and the ember grate are pre-calculated based on the basic parameters of the garbage incinerator; the movement of the pusher and the ember grate is controlled separately according to the standard speeds of the pusher and the ember grate, and the movement of the drying grate and the combustion grate is controlled separately according to the corrected standard speeds of the drying grate and the combustion grate.

[0039] Optionally, the measuring unit is also used to measure the thickness of the garbage layer on the ember grate;

[0040] The control unit is also used to perform closed-loop regulation according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; and the control of the pusher and the combustion grate movement according to their standard speeds, as well as the control of the drying grate and the burning grate movement according to their corrected standard speeds, is replaced by: controlling the pusher movement according to the standard speed of the pusher, and controlling the drying grate, the burning grate and the combustion grate movement according to their corrected standard speeds.

[0041] Optionally, when measuring the thickness of the garbage layer on any section of the grate, the measuring unit uses multiple differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of this section of the grate, calculates the average value, and then converts it to obtain the corresponding garbage layer thickness.

[0042] Optionally, when measuring the thickness of the garbage material layer on any section of the grate, the measuring unit uses a differential pressure transmitter to measure the upper and lower pressure difference of the garbage material layer on the left half of this section of the grate, and uses another differential pressure transmitter to measure the upper and lower pressure difference of the garbage material layer on the right half of this section of the grate, and then calculates the average of the two pressure differences and converts them to obtain the corresponding garbage material layer thickness.

[0043] It can be seen from the above technical scheme that the present invention not only measures the thickness of the garbage layer on the combustion grate, but also measures the thickness of the garbage layer on the drying grate in real time; when the speed of the drying grate is adjusted according to the thickness of the garbage layer on the combustion grate, the movement speed of the drying grate is also accurately adjusted according to the thickness of the garbage layer on the drying grate to ensure that the thickness of the garbage layer on the drying grate is within a reasonable range. In this way, the deviation between the thickness of the garbage layer formed on the combustion grate and the set value will not be very large. Therefore, the adjustment range of the thickness of the garbage layer on the combustion grate is not large, thereby achieving the purpose of stable feeding, and the furnace temperature will not fluctuate greatly, thereby ensuring the incineration stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of a garbage incinerator structure and a differential pressure transmitter installation position disclosed in the prior art;

[0046] Figure 2A flow chart of a method for controlling the thickness of a garbage layer in a garbage incinerator disclosed in an embodiment of the present invention;

[0047] Figure 3 A schematic diagram of the installation position of a differential pressure transmitter disclosed in an embodiment of the present invention;

[0048] Figure 4 A block diagram of standard speed calculation of a pusher and a drying grate disclosed in an embodiment of the present invention;

[0049] Figure 5 A block diagram of a calculation of a corrected standard speed of a drying grate disclosed in an embodiment of the present invention;

[0050] Figure 6 A block diagram of a corrected standard speed calculation of a combustion grate disclosed in an embodiment of the present invention;

[0051] Figure 7 A block diagram of a corrected standard speed calculation of a burning grate disclosed in an embodiment of the present invention;

[0052] Figure 8 This is a schematic diagram of the installation position of another differential pressure transmitter disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figure 2 The embodiment of the present invention discloses a method for controlling the thickness of a garbage layer in a garbage incinerator, comprising:

[0055] Step S01: measuring the thickness of the garbage layer on the drying grate 1, the combustion grate 2 and the ember grate 3 respectively.

[0056] Specifically, for any of the three grates, namely, the drying grate 1, the combustion grate 2 and the ember grate 3, the method for measuring the thickness of the garbage layer on the grate of this section can be, for example, using multiple differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of the grate of this section, finding the average value, and then converting to obtain the corresponding garbage layer thickness. As a recommendation, a differential pressure transmitter can be used to measure the upper and lower pressure differences of the garbage layer on the left half of the grate of this section, and another differential pressure transmitter can be used to measure the upper and lower pressure differences of the garbage layer on the right half of the grate of this section, and then the two pressure differences are averaged, and then the corresponding garbage layer thickness is converted according to the average value.

[0057] The differential pressure transmitter is a transmitter used to measure the pressure difference on both sides of the measured medium. Its structure and working principle are as follows: the differential pressure transmitter has two pressure interfaces, one is the positive pressure end for measuring the pressure on the positive pressure side of the measured medium (the positive pressure side refers to the measurement direction in which the gas pressure is higher than the normal pressure), and the other is the negative pressure end for measuring the pressure on the negative pressure side of the measured medium (the negative pressure side refers to the measurement direction in which the gas pressure is lower than the normal pressure); when the pressure on both sides of the measured medium acts on the differential pressure sensor, the pressure sensor converts the pressure signal into an electrical signal, which is amplified by the differential amplifier and the output amplifier, and finally converted into a standard current output signal that is linearly corresponding to the pressure difference on both sides of the measured medium through the V / A voltage and current.

[0058] The system control unit determines the pressure difference on both sides of the measured medium according to the standard current output signal output by the differential pressure transmitter. The pressure difference on both sides of the measured medium corresponds to the thickness of the measured medium (the greater the pressure difference on both sides of the measured medium, the thicker the measured medium, and vice versa), and thus the thickness of the measured medium can be obtained.

[0059] The gas pressure in the furnace above the grate is lower than the normal pressure. The primary air chamber below the grate (the primary air chamber refers to the position where the primary air enters the grate below the grate, which is bucket-shaped. Usually, the garbage incinerator has two rows of grates. In the longitudinal direction, the primary air chamber below the grate is divided into a left and a right; in the transverse direction, the drying grate 1 only includes one section of the air chamber, the primary air chamber below the combustion grate 2 includes one section of the air chamber, a second section of the air chamber and a third section of the air chamber, and the primary air chamber below the burning grate 3 includes one section of the air chamber and a second section of the air chamber. Figure 3 Based on this, the negative pressure end pressure of the differential pressure transmitter designed in the embodiment of the present invention is drawn from the furnace above the grate, and the positive pressure end pressure is drawn from the primary air chamber below the grate, and then the thickness of the garbage layer on the grate is obtained by converting the output data of the differential pressure transmitter.

[0060] For any section of the three grates, namely, the drying grate 1, the combustion grate 2 and the ember grate 3, when measuring the thickness of the garbage layer on the grate in this section, the more differential pressure transmitters are used and the more evenly the differential pressure transmitters are distributed, the more accurately the thickness of the garbage layer on the grate in this section can be reflected, but the corresponding cost is also higher. Therefore, the embodiment of the present invention recommends using two differential pressure transmitters, one on the left and one on the right, for this section of the grate. The two differential pressure transmitters are preferably symmetrically installed on both sides of the furnace wall ( Figure 1 and Figure 3 Only the differential pressure transmitter on one side of the furnace wall is shown in the figure. Figure 1 and Figure 3 The figure in the figure is marked with 6; Figure 3 and Figure 1 The main difference lies in the number of differential pressure transmitters used and the different installation locations. Figure 1 Only the thickness of the garbage layer on the combustion grate 2 is measured. Figure 3 The thickness of the garbage layer on the drying grate 1, the combustion grate 2 and the ember grate 3 is measured simultaneously).

[0061] When the waste incinerator uses Figure 3 In the two-row grate structure shown in the figure, and two differential pressure transmitters are allocated to the drying grate 1, the combustion grate 2 and the ember grate 3, respectively, it is recommended that the high-pressure ends of the two differential pressure transmitters corresponding to each grate section measure the gas pressure in the two air chambers on the left and right below the grate section to improve the measurement accuracy.

[0062] Step S02: Controlling the speed of the drying grate 1, the combustion grate 2, the ember grate 3 and the pusher 4.

[0063] Specifically, the embodiment of the present invention calculates a grate standard speed S1 in advance according to the basic parameters of the waste incinerator, and uses S1 as the standard speed of the combustion grate 2 and the ember burning grate 3. The grate standard speed S1 is not only related to the evaporation amount of the waste incinerator, but also affected by parameters such as the mechanical size of the grate, the steam enthalpy value, the boiler efficiency, and the low calorific value of the waste. The calculation formula is:

[0064] S1=V1*F1(x)

[0065] Wherein, V1=C2*FT / C1 / LHV / T;

[0066] V1 represents the required garbage volume, in m 3 ;

[0067] C1 represents boiler thermal efficiency, unit: %;

[0068] C2 represents boiler steam enthalpy, unit KJ / kg;

[0069] FT represents the boiler steam volume setting value, unit is h / t;

[0070] LHV means the lower heating value of garbage, in KJ / kg;

[0071] T represents the specific gravity of garbage, unit: t / m 3 ;

[0072] F1(x) represents the inverse of the feed throat area, unit 1 / ㎡;

[0073] S1 represents the standard speed of the combustion and ember grate, in m / h.

[0074] The step S02 is based on the measured value in step S01 and is implemented as S1, and specifically includes the following parts 1) to 5):

[0075] 1) A closed-loop adjustment is performed based on the deviation between the measured value of the thickness of the garbage layer on the combustion grate 2 and the set value, and the output of the closed-loop adjustment is converted to obtain the standard speed of the pusher 4 and the drying grate 1.

[0076] See also Figure 4 , Figure 4 Take the allocation of two differential pressure transmitters GI2A and GI2B, one on the left and one on the right, to the combustion grate 2 as an example: the output data of the differential pressure transmitters GI2A and GI2B are averaged by the averaging function AVE, and the average value reflects the measured value of the thickness of the garbage layer on the combustion grate 2; PID adjustment is performed according to the deviation between the average value and the set value SV2 of the thickness of the garbage layer on the combustion grate 2, and the output of the PID adjustment is converted by a conversion function F3(x) to obtain the standard speed S2 of the pusher 4 and the standard speed S3 of the drying grate 1; wherein, PID adjustment is a transfer function commonly used for closed-loop regulation, and other transfer functions can also be used in addition to this, without limitation.

[0077] 2) A closed-loop adjustment is performed based on the deviation between the measured value of the thickness of the garbage layer on the drying grate 1 and the set value. The output of the closed-loop adjustment is multiplied by a certain proportional coefficient and used as the deviation correction value of the standard speed of the drying grate 1.

[0078] See also Figure 5 , Figure 5 Take the allocation of two differential pressure transmitters GI1A and GI1B on the left and right for the drying grate 1 as an example: the output data of the differential pressure transmitters GI1A and GI1B are averaged by the averaging function AVE, and the average value reflects the measured value of the thickness of the garbage layer on the drying grate 1; PID adjustment is performed according to the deviation between the average value and the set value SV1 of the thickness of the garbage layer on the drying grate 1, and the output of the PID adjustment is multiplied by a certain proportional coefficient C3 as the deviation correction value ΔS2 of the standard speed of the drying grate 1; ΔS2 and the standard speed S3 of the drying grate 1 are added and subtracted to obtain the corrected standard speed S4 of the drying grate 1; wherein, PID adjustment is a transfer function commonly used in closed-loop adjustment, and other transfer functions can also be used in addition to this, without limitation.

[0079] Since the main combustion area is still in the combustion grate 2, the speed of the pusher 4 and the drying grate 1 is mainly affected by the thickness of the garbage layer on the combustion grate 2. The thickness of the garbage layer on the drying grate 1 is used as an interference factor to adjust the actual speed of the drying grate 1 (the proportional coefficient C3 is a preset value, and the size of C3 determines the influence of the thickness of the garbage layer on the drying grate 1 on the speed of the drying grate 1), so that the speed of the drying grate 1 can be adjusted in combination with the thickness of the garbage layer on the drying grate 1.

[0080] 3) A closed-loop adjustment is performed based on the deviation between the measured value of the thickness of the garbage layer on the combustion grate 2 and the set value. The output of the closed-loop adjustment is multiplied by a certain proportional coefficient and used as the deviation correction value of the standard speed of the combustion grate 2.

[0081] See also Figure 6 , Figure 6 Still take the allocation of two differential pressure transmitters GI2A and GI2B on the left and right for the combustion grate 2 as an example: the output data of the differential pressure transmitters GI2A and GI2B are averaged by the averaging function AVE, and the average value reflects the measured value of the thickness of the garbage layer on the combustion grate 2; PID adjustment is performed according to the deviation between the average value and the set value SV2 of the thickness of the garbage layer on the combustion grate 2, and the output of the PID adjustment is multiplied by a certain proportional coefficient C4 as the deviation correction value ΔS3 of the standard speed of the combustion grate 2; ΔS3 and the standard speed S1 of the combustion grate 2 are added and subtracted to obtain the corrected standard speed S5 of the combustion grate 2; wherein, PID adjustment is a transfer function commonly used in closed-loop regulation, and other transfer functions can also be used without limitation; the proportional coefficient C4 is a preset value, and the size of C4 determines the degree of influence of the thickness of the garbage layer on the combustion grate 2 on the speed of the combustion grate 2.

[0082] 4) Closed-loop regulation is performed according to the deviation between the measured value of the thickness of the garbage layer on the ember grate 3 and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the ember grate 3.

[0083] See also Figure 7 , Figure 7 Take the allocation of two differential pressure transmitters GI3A and GI3B on the left and right of the burning grate 3 as an example: the output data of the differential pressure transmitters GI3A and GI3B are averaged by the averaging function AVE, and the average value reflects the measured value of the thickness of the garbage layer on the burning grate 3; PID adjustment is performed according to the deviation between the average value and the set value SV3 of the thickness of the garbage layer on the burning grate 3, and the output of the PID adjustment is multiplied by a certain proportional coefficient C5 as the deviation correction value ΔS4 of the standard speed of the burning grate 3; ΔS4 and the standard speed S1 of the burning grate 3 are added and subtracted to obtain the corrected standard speed S6 of the burning grate 3; wherein, PID adjustment is a transfer function commonly used in closed-loop adjustment, and other transfer functions may also be used; the proportional coefficient C5 is a preset value, and the size of C5 determines the influence of the thickness of the garbage layer on the burning grate 3 on the speed of the burning grate 3.

[0084] In the case of insufficient combustion of the garbage on the combustion grate 2, the ember grate 3 bears the combustion task of the combustion grate 2 to a certain extent. Therefore, in order to ensure the combustion stability, it is recommended to make a deviation correction to the standard speed of the ember grate 3 in combination with the thickness of the garbage layer on the ember grate 3, for example Figure 7 shown.

[0085] 5) Controlling the movement of the pusher 4 according to its standard speed, and controlling the movement of the drying grate 1, the combustion grate 2 and the ember grate 3 according to their corrected standard speeds.

[0086] It can be seen from the above description that, compared with the prior art, the key to the embodiment of the present invention lies in the addition of parts 2) and 4). The embodiment of the present invention not only measures the thickness of the garbage layer on the combustion grate 2, but also measures the thickness of the garbage layer on the drying grate 1 and the ember grate 3 in real time; when adjusting the speed of the drying grate 1 according to the thickness of the garbage layer on the combustion grate 2, the movement speed of the drying grate 1 is also accurately adjusted according to the thickness of the garbage layer on the drying grate 1 to ensure that the thickness of the garbage layer on the drying grate 1 is within a reasonable range, so that the deviation between the thickness of the garbage layer formed on the combustion grate 2 and the set value will not be large, so the adjustment range of the thickness of the garbage layer on the combustion grate 2 is not large, achieving the purpose of stable feeding, and the furnace temperature will not fluctuate greatly, ensuring the incineration stability. In addition, the ember grate 3 bears the combustion task of the combustion grate 2 to a certain extent, so in order to further ensure the combustion stability, the embodiment of the present invention also combines the thickness of the garbage layer on the ember grate 3 to make a deviation correction for the standard speed of the ember grate 3.

[0087] Of course, when the garbage on the combustion grate 2 is fully burned or the requirement for combustion completeness is slightly lower, the standard speed of the combustion grate 3 may be corrected for deviation without considering the thickness of the garbage layer on the combustion grate 3, that is: the thickness of the garbage layer on the combustion grate 3 is not obtained, and the part 4) in the above method is omitted. Correspondingly, the part 5) is replaced by: controlling the movement of the pusher 4 and the combustion grate 3 according to their standard speeds, and controlling the movement of the drying grate 1 and the combustion grate 2 according to their corrected standard speeds.

[0088] Optionally, in any of the embodiments disclosed above, the corrected standard speed of any grate may be further corrected for deviation in combination with other influencing factors (such as furnace temperature, etc.) to further improve the combustion stability.

[0089] Corresponding to the above method embodiment, the embodiment of the present invention further discloses a waste material layer thickness control system for a waste incinerator, comprising:

[0090] Measuring unit, used to measure the thickness of the garbage layer on the drying grate and the combustion grate respectively;

[0091] A control unit is used to perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and the output of the closed-loop regulation is converted to obtain the standard speed of the pusher and the drying grate; perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the drying grate, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate; perform closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; wherein the standard speeds of the combustion grate and the ember grate are pre-calculated based on the basic parameters of the garbage incinerator; the movement of the pusher and the ember grate is controlled separately according to the standard speeds of the pusher and the ember grate, and the movement of the drying grate and the combustion grate is controlled separately according to the corrected standard speeds of the drying grate and the combustion grate.

[0092] Optionally, the measuring unit is also used to measure the thickness of the garbage layer on the ember grate;

[0093] The control unit is also used to perform closed-loop regulation according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; and the control of the pusher and the combustion grate movement according to their standard speeds, as well as the control of the drying grate and the burning grate movement according to their corrected standard speeds, is replaced by: controlling the pusher movement according to the standard speed of the pusher, and controlling the drying grate, the burning grate and the combustion grate movement according to their corrected standard speeds.

[0094] Optionally, in any of the control systems disclosed above, when measuring the thickness of the garbage layer on any section of the grate, the measuring unit uses multiple differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of this section of the grate, calculates the average value, and then converts it to obtain the corresponding garbage layer thickness.

[0095] Optionally, in any of the control systems disclosed above, when measuring the thickness of the garbage material layer on any section of the grate, the measuring unit uses a differential pressure transmitter to measure the upper and lower pressure differences of the garbage material layer on the left half of this section of the grate, and uses another differential pressure transmitter to measure the upper and lower pressure differences of the garbage material layer on the right half of this section of the grate, and then calculates the average of the two pressure differences and converts them to obtain the corresponding garbage material layer thickness.

[0096] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0097] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the embodiments of the present invention. Therefore, the embodiments of the present invention will not be limited to the embodiments shown herein, but rather to the widest range consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the thickness of garbage layer in a garbage incinerator, It is characterized in that include: Measure the thickness of the garbage layer on the drying grate and the combustion grate respectively; According to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, a closed-loop adjustment is performed, and the output of the closed-loop adjustment is converted to obtain the standard speed of the pusher and the drying grate; Closed-loop regulation is performed according to the deviation between the measured value of the thickness of the garbage layer on the drying grate and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate; A closed-loop adjustment is performed according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, and the output of the closed-loop adjustment is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; wherein the standard speeds of the combustion grate and the ember grate are pre-calculated according to the basic parameters of the garbage incinerator; Controlling the movement of the pusher and the ember grate according to their standard speeds, and controlling the movement of the drying grate and the burning grate according to their revised standard speeds; The formula for calculating the standard speed of the burning and ember grate according to the basic parameters of the garbage incinerator is: S1= F1(x) *(C2*FT / C1 / LHV / T) In the formula, C1 represents boiler thermal efficiency, unit: % C2 represents boiler steam enthalpy, unit KJ / kg; FT represents the boiler steam volume setting value, unit is t / h; LHV means the lower heating value of garbage, in KJ / kg; T represents the specific gravity of garbage, in t / m³; F1(x) represents the inverse of the feed throat area, unit: 1 / ㎡; S1 represents the standard speed of the burning and embering grate, in m / h.

2. The method for controlling the thickness of the garbage layer in a garbage incinerator according to claim 1, It is characterized in that Before the pusher and the ember grate are controlled to move according to their standard speeds, and the drying grate and the burning grate are controlled to move according to their corrected standard speeds, the method further includes: measuring the thickness of the garbage layer on the burning grate; A closed-loop adjustment is performed according to the deviation between the measured value of the thickness of the garbage layer on the ember grate and the set value, and the output of the closed-loop adjustment is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the ember grate; The method of controlling the movement of the pusher and the ember grate according to their standard speeds, and controlling the movement of the drying grate and the burning grate according to their revised standard speeds, can be replaced by: controlling the movement of the pusher according to their standard speed, and controlling the movement of the drying grate, the burning grate and the ember grate according to their revised standard speeds.

3. The method for controlling the thickness of the garbage layer in a garbage incinerator according to claim 1 or 2, It is characterized in that Measure the thickness of the waste layer on any section of the grate, including: Use multiple differential pressure transmitters to measure the upper and lower pressure differences of the garbage layer at different positions of this grate, calculate the average value, and then convert it to obtain the corresponding garbage layer thickness.

4. The method for controlling the thickness of the garbage layer in a garbage incinerator according to claim 3, It is characterized in that The method of using a plurality of differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of the grate in this section, calculating the average value thereof, and then converting the corresponding garbage layer thickness to obtain the corresponding garbage layer thickness includes: A differential pressure transmitter is used to measure the upper and lower pressure difference of the garbage layer on the left half of this grate section, and another differential pressure transmitter is used to measure the upper and lower pressure difference of the garbage layer on the right half of this grate section. The two pressure differences are then averaged and converted to obtain the corresponding garbage layer thickness.

5. The method for controlling the thickness of the garbage layer in a garbage incinerator according to claim 1, It is characterized in that Also includes: The corrected standard speed of any grate is further corrected for deviation in combination with other influencing factors, wherein the other influencing factors include furnace temperature.

6. A garbage layer thickness control system for a garbage incinerator. It is characterized in that include: Measuring unit, used to measure the thickness of the garbage layer on the drying grate and the combustion grate respectively; A control unit, used for performing closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and converting the output of the closed-loop regulation to obtain the standard speed of the pusher and the drying grate; performing closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the drying grate, and multiplying the output of the closed-loop regulation by a certain proportional coefficient as the deviation correction value of the standard speed of the drying grate; performing closed-loop regulation according to the deviation between the measured value and the set value of the thickness of the garbage layer on the combustion grate, and multiplying the output of the closed-loop regulation by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; wherein the standard speeds of the combustion grate and the ember grate are pre-calculated according to the basic parameters of the garbage incinerator; controlling the movement of the pusher and the ember grate respectively according to their standard speeds, and controlling the movement of the drying grate and the combustion grate respectively according to the corrected standard speeds of the drying grate and the combustion grate; The formula for calculating the standard speed of the burning and ember grate according to the basic parameters of the garbage incinerator is: S1= F1(x) *(C2*FT / C1 / LHV / T) In the formula, C1 represents boiler thermal efficiency, unit: % C2 represents boiler steam enthalpy, unit KJ / kg; FT represents the boiler steam volume setting value, unit is t / h; LHV means the lower heating value of garbage, in KJ / kg; T represents the specific gravity of garbage, in t / m³; F1(x) represents the inverse of the feed throat area, unit: 1 / ㎡; S1 represents the standard speed of the burning and embering grate, in m / h.

7. The garbage layer thickness control system for a garbage incinerator according to claim 6, It is characterized in that The measuring unit is also used to measure the thickness of the garbage layer on the ember grate; The control unit is also used to perform closed-loop regulation according to the deviation between the measured value of the thickness of the garbage layer on the combustion grate and the set value, and the output of the closed-loop regulation is multiplied by a certain proportional coefficient as the deviation correction value of the standard speed of the combustion grate; and the control of the pusher and the combustion grate movement according to their standard speeds, as well as the control of the drying grate and the burning grate movement according to their corrected standard speeds, is replaced by: controlling the pusher movement according to the standard speed of the pusher, and controlling the drying grate, the burning grate and the combustion grate movement according to their corrected standard speeds.

8. The garbage layer thickness control system for a garbage incinerator according to claim 6 or 7, It is characterized in that When measuring the thickness of the garbage layer on any section of the grate, the measuring unit uses multiple differential pressure transmitters to respectively measure the upper and lower pressure differences of the garbage layer at different positions of this section of the grate, calculates the average value, and then converts it to obtain the corresponding garbage layer thickness.

9. The garbage layer thickness control system for a garbage incinerator according to claim 8, It is characterized in that When measuring the thickness of the garbage layer on any section of the grate, the measuring unit uses a differential pressure transmitter to measure the upper and lower pressure differences of the garbage layer on the left half of this section of the grate, and uses another differential pressure transmitter to measure the upper and lower pressure differences of the garbage layer on the right half of this section of the grate, and then calculates the average of the two pressure differences and converts them to obtain the corresponding garbage layer thickness.

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