Automatic feeding method based on more than one advance time of the grate

Abstract

This invention relates to an automatic feeding method based on the upper grate advance time, belonging to the field of waste incineration control technology, and includes the following steps: S1: The DCS control system collects the start and end times of the upper grate advance and calculates the upper grate advance time; S2: The DCS control system recalculates the feeding speed of the feeder based on the change in the upper grate advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the feeding speed of the feeder; S3: The DCS control system recalculates the number of cycles of the upper grate based on the change in the upper grate advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the upper grate; S4: The DCS control system recalculates the number of cycles of the lower grate based on the change in the upper grate advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the lower grate.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration control technology and relates to an automatic feeding method based on the grate advance time. Background Technology

[0002] The complex composition and low calorific value of current municipal solid waste lead to unstable combustion conditions in waste incinerators. Most incinerators have a dedicated operator for each incinerator, and most equipment related to waste incineration control operates manually. Stable operation relies entirely on the operator's experience to adjust parameters such as airflow, air-fuel ratio, feed rate, and grate speed in different sections of the grate. Even slight changes in combustion conditions require constant adjustments, and improper or untimely operations can cause even greater fluctuations in combustion. Therefore, the automation level of incinerator combustion control is low, and manual control results in poor operational stability. Many equipment manufacturers have invested significant resources in researching automatic combustion control systems for municipal solid waste incinerators, aiming to achieve stable operation by automatically adjusting to changes in the calorific value of the waste.

[0003] Currently, the most widely used automatic combustion control systems (ACC) for waste incineration are not only expensive, but also subject to core technology restrictions. Furthermore, having ACC functionality is one of the essential requirements for bidding on new projects. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a low-cost, stable and reliable automatic feeding method based on the above grate advance time.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An automatic feeding method based on the grate advance time includes the following steps:

[0007] S1: The DCS control system collects the start and end times of the upper grate's advance and calculates the advance time of the upper grate.

[0008] S2: The DCS control system recalculates the feeding speed of the feeder based on the change in the advance time of the upper grate, and sends the calculation result to the hydraulic station control system of the incinerator grate to adjust the feeding speed of the feeder.

[0009] S3: The DCS control system recalculates the number of cycles of the upper grate based on the change in the upper grate advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the upper grate.

[0010] S4: The DCS control system recalculates the number of cycles of the lower grate based on the change in the advance time of the upper grate, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the lower grate.

[0011] Furthermore, in step S1, the incinerator grate hydraulic station control system sends a notification to the DCS control system when the upper grate starts to move forward and when it stops moving forward. The DCS control system starts timing when the upper grate starts to move forward and stops timing when the upper grate moves to the position, thereby obtaining the forward time Tq of the upper grate. When the upper grate moves forward for the next cycle, the forward time Tq is reset.

[0012] Furthermore, in step S2, the DCS control system sets the standard time Ts for the upper grate to advance, the time Tb for the feeder speed to remain constant, the time Tm for the feeder speed to decrease to its minimum, the upper limit Smax for the feeder speed, and the lower limit Smin for the feeder speed. Based on the changes in the upper grate's advance time, the feeder's pushing speed is adjusted as follows:

[0013] When |Tq-Ts|≤Tb, the feeder speed remains unchanged until the next cycle, at which point the judgment is repeated.

[0014] When 10 seconds > Tq - Ts > Tb, the feeder speed is reduced by 0.1 m / h to 0.5 m / h from the original speed. If the adjusted feeder speed is less than Smin, it runs at the Smin speed until the next cycle.

[0015] When 20 seconds > Tq - Ts ≥ 10 seconds, the feeder speed is reduced by 0.5 m / h to 1.0 m / h from the original speed. If the calculated speed of the feeder after adjustment is less than Smin, it will run at the speed of Smin until the next cycle.

[0016] When Tm > Tq - Ts ≥ 20 seconds, the feeder speed is reduced to Smin from its original value until the next cycle, and this process is repeated.

[0017] When 10 seconds > Ts-Tq > Tb, the feeder speed is increased by 0.1m / h to 0.5m / h from the original speed. If the calculated speed of the feeder after adjustment is greater than Smax, it will run at the speed of Smax until the next cycle.

[0018] When 20 seconds > Ts - Tq ≥ 10 seconds, the feeder speed is increased by 0.5 m / h to 1.0 m / h. If the calculated speed of the feeder after adjustment is greater than Smax, it will run at the speed of Smax until the next cycle.

[0019] Furthermore, in step S3, the DCS control system sets the baseline value Hb for the number of upper grate cycles, the upper limit Hmax for the number of upper grate cycles, and the lower limit Hmin for the number of upper grate cycles, and adjusts the number of upper grate cycles according to the change in the upper grate advance time as follows:

[0020] When |Tq-Ts|≤Tb, the number of cycles for the upper grate remains unchanged until the next cycle, and so on.

[0021] When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down. For intermediate parameters, Take 3~5; if the adjusted number of cycles of the upper grate is less than Hmin, then run according to Hmin until the next cycle, and so on.

[0022] When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down. For intermediate parameters, Select 3 to 5; if the adjusted number of cycles of the upper grate is greater than Hmax, then run according to Hmax until the next cycle, and so on.

[0023] Furthermore, in step S4, the DCS control system sets the baseline value Lb for the number of lower grate cycles, the upper limit Lmax for the number of lower grate cycles, and the lower limit Lmin for the number of lower grate cycles, and adjusts the number of lower grate cycles according to the change in the upper grate advance time as follows:

[0024] When |Tq-Ts|≤Tb, the number of cycles for the lower grate remains unchanged until the next cycle, and so on.

[0025] When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down. b For intermediate parameters, b If the adjusted number of cycles for the lower grate is less than Lmin, then run according to Lmin until the next cycle, and so on.

[0026] When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down. b For intermediate parameters, b If the adjusted number of cycles for the lower grate is greater than Lmax, then run according to Lmax until the next cycle, and so on.

[0027] The beneficial effects of this invention are as follows: This invention effectively solves the problem of untimely manual adjustment of municipal solid waste feeding, which leads to waste accumulation or shortage, thereby ensuring more stable combustion of municipal solid waste and boiler evaporation, and reducing the labor intensity of power plant operators. This invention utilizes a DCS control system as a development platform and adopts modular packaging technology, making project implementation convenient and highly practical.

[0028] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0030] Figure 1 A schematic diagram of the feeding structure for a 600-ton / day incinerator;

[0031] Figure 2 This is a schematic diagram of the data exchange framework between the DCS system and the incinerator grate hydraulic station control system. Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0033] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0034] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0035] This invention provides an automatic feeding method based on the grate advance time. In this embodiment, automatic feeding control is implemented for the core equipment of a 600-ton / day incinerator. Figure 1 The diagram shows the incinerator feeding structure used in this embodiment, which includes 4 feeders (8 rows of feeding trolleys), 4 rows of upper grates, and 4 rows of lower grates. The feeders are driven forward and backward by 8 high-pressure hydraulic cylinders controlled by 4 servo valves, and the upper and lower grates are driven forward and backward by 8 high-pressure hydraulic cylinders controlled by 8 servo valves, respectively.

[0036] like Figure 2 As shown, in this embodiment, the DCS system and the incinerator grate hydraulic station control system exchange data via Profibus-DP communication, collecting important parameters of the incinerator system and controlling all equipment of the incinerator system on the DCS operating interface. The automatic feeding system based on the grate advance time uses a separate core control program, which exchanges data with other systems on the DCS platform, such as the primary and secondary air systems, via I / O interfaces. This program performs relevant calculations based on the grate advance time and transmits the results to the incinerator grate hydraulic station control system, automatically controlling the feeder and core equipment such as the upper and lower grates.

[0037] The automatic feeding process is as follows:

[0038] S1: The DCS control system collects the start and end times of the upper grate's advance and calculates the grate's advance time. Specifically, the incinerator grate hydraulic station control system sends notifications to the DCS control system when the upper grate begins and ends its advance. The DCS control system starts timing from the start of the upper grate's advance until it reaches its final position, thus obtaining the upper grate's advance time Tq. When the upper grate begins its next cycle of advance, the advance time Tq is reset to zero. In this embodiment, the advance time Tq = 75 seconds.

[0039] S2: The DCS control system recalculates the feeding speed of the feeder based on the change in the advance time of the upper grate, and sends the calculation result to the hydraulic station control system of the incinerator grate to adjust the feeding speed of the feeder.

[0040] The DCS control system sets the standard time Ts for the upper grate advance, the time Tb for the feeder speed to remain constant, the time Tm for the feeder speed to decrease to its minimum, the upper limit Smax for the feeder speed, and the lower limit Smin for the feeder speed. In this embodiment, Ts = 68 seconds, Tb = 2 seconds, Tm = 120 seconds, Smin = 0.1 m / h, and Smax = 5 m / h. Based on the change in the upper grate advance time, the feeder's pushing speed is adjusted as follows:

[0041] When |Tq-Ts|≤Tb, the feeder speed is kept constant until the next cycle, and this process is repeated.

[0042] When 10 seconds > Tq - Ts > Tb, the feeder speed is reduced by 0.2 m / h from the original speed. If the adjusted feeder speed is less than Smin, the feeder will run at the Smin speed until the next cycle.

[0043] When 20 seconds > Tq - Ts ≥ 10 seconds, the feeder speed is reduced by 0.5 m / h from the original speed. If the calculated speed of the feeder after adjustment is less than Smin, it will run at the speed of Smin until the next cycle.

[0044] When Tm > Tq - Ts ≥ 20 seconds, the feeder speed is reduced to Smin from its original value until the next cycle, and this process is repeated.

[0045] When 10 seconds > Ts-Tq > Tb, the feeder speed is increased by 0.2 m / h. If the calculated speed of the feeder after adjustment is greater than Smax, it will run at the speed of Smax until the next cycle.

[0046] When 20 seconds > Ts - Tq ≥ 10 seconds, the feeder speed is increased by 0.5 m / h. If the calculated speed of the adjusted feeder is greater than Smax, it will run at the Smax speed until the next cycle, and so on.

[0047] In this embodiment, Ts = 68 seconds and Tq = 75 seconds. According to the above rule, when 10 seconds > Tq - Ts > 2 seconds, the feeder speed is the current value minus 0.2 m / h. If the adjusted feeder speed is less than 0.1 m / h, it will operate at 0.1 m / h.

[0048] S3: The DCS control system recalculates the number of cycles of the upper grate based on the change in the upper grate's advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the upper grate. The DCS control system sets the upper grate cycle count baseline value Hb, the upper grate cycle count upper limit Hmax, and the upper grate cycle count lower limit Hmin. In this embodiment, Hb=14, Hmax=18, and Hmin=10. Based on the change in the upper grate's advance time, the number of cycles of the upper grate is adjusted as follows:

[0049] When |Tq-Ts|≤Tb, the number of cycles for the upper grate remains unchanged until the next cycle, and so on.

[0050] When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down; if the adjusted number of cycles for the upper grate is less than Hmin, then it will run according to Hmin until the next cycle, and so on.

[0051] When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down; if the adjusted number of cycles for the upper grate is greater than Hmax, then it will run according to Hmax until the next cycle, and so on.

[0052] In this embodiment, Ts = 68 seconds and Tq = 75 seconds. Therefore, according to the above rule, 75 - 68 > 2, the number of cycles for the upper grate is: .

[0053] S4: The DCS control system recalculates the number of cycles for the lower grate based on the change in the upper grate's advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles for the lower grate. The DCS control system sets a baseline value Lb for the number of cycles for the lower grate, an upper limit Lmax for the number of cycles for the lower grate, and a lower limit Lmin for the number of cycles for the lower grate. In this embodiment, Lb=8, Lmax=12, and Lmin=4. Based on the change in the upper grate's advance time, the number of cycles for the lower grate is adjusted as follows:

[0054] When |Tq-Ts|≤Tb, the number of cycles for the lower grate remains unchanged until the next cycle, and so on.

[0055] When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down. If the adjusted number of cycles for the lower grate is less than Lmin, then it will run according to Lmin until the next cycle, and so on.

[0056] When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down. If the adjusted number of cycles for the lower grate is greater than Lmax, then it will run according to Lmax until the next cycle, and so on.

[0057] In this embodiment, Ts = 68 seconds and Tq = 75 seconds. Therefore, according to the above rule, 75 - 68 > 2, the number of cycles for the lower grate is: .

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An automatic feeding method based on the advance time of one or more grate furnaces, characterized in that: Includes the following steps: S1: The DCS control system collects the start and end times of the upper grate's advance and calculates the advance time Tq of the upper grate; S2: The DCS control system recalculates the feeding speed of the feeder based on the change in the advance time of the upper grate, and sends the calculation result to the hydraulic station control system of the incinerator grate to adjust the feeding speed of the feeder. The DCS control system sets the standard time Ts for the upper grate to advance, the time Tb for the feeder speed to remain constant, the time Tm for the feeder speed to decrease to its minimum, the upper limit Smax for the feeder speed, and the lower limit Smin for the feeder speed. Based on the changes in the upper grate's advance time, the feeder's pushing speed is adjusted as follows: When |Tq-Ts|≤Tb, the feeder speed remains unchanged until the next cycle, at which point the judgment is repeated. When 10 seconds > Tq - Ts > Tb, the feeder speed is reduced by 0.1 m / h to 0.5 m / h from the original speed. If the adjusted feeder speed is less than Smin, it runs at the Smin speed until the next cycle. When 20 seconds > Tq - Ts ≥ 10 seconds, the feeder speed is reduced by 0.5 m / h to 1.0 m / h from the original speed. If the calculated speed of the feeder after adjustment is less than Smin, it will run at the speed of Smin until the next cycle. When Tm > Tq - Ts ≥ 20 seconds, the feeder speed is reduced to Smin from its original value until the next cycle, and this process is repeated. When 10 seconds > Ts-Tq > Tb, the feeder speed is increased by 0.1m / h to 0.5m / h from the original speed. If the calculated speed of the feeder after adjustment is greater than Smax, it will run at the speed of Smax until the next cycle. When 20 seconds > Ts - Tq ≥ 10 seconds, the feeder speed is increased by 0.5 m / h to 1.0 m / h. If the calculated speed of the feeder after adjustment is greater than Smax, it will run at the speed of Smax until the next cycle. S3: The DCS control system recalculates the number of cycles of the upper grate based on the change in the upper grate advance time, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the upper grate. S4: The DCS control system recalculates the number of cycles of the lower grate based on the change in the advance time of the upper grate, and sends the calculation result to the incinerator grate hydraulic station control system to adjust the number of cycles of the lower grate.

2. The automatic feeding method based on the grate advance time according to claim 1, characterized in that: In step S1, the incinerator grate hydraulic station control system sends a notification to the DCS control system when the upper grate starts to move forward and when it stops moving forward. The DCS control system starts timing when the upper grate starts to move forward and stops timing when the upper grate reaches the position, thus obtaining the forward time Tq of the upper grate. When the upper grate starts to move forward in the next cycle, the forward time Tq is reset.

3. The automatic feeding method based on the grate advance time according to claim 1, characterized in that: In step S3, the DCS control system sets the baseline value Hb for the number of upper grate cycles, the upper limit Hmax for the number of upper grate cycles, and the lower limit Hmin for the number of upper grate cycles, and adjusts the number of upper grate cycles according to the change in the upper grate advance time as follows: When |Tq-Ts|≤Tb, the number of cycles for the upper grate remains unchanged until the next cycle, and so on. When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down. For intermediate parameters, Take 3~5; if the adjusted number of cycles of the upper grate is less than Hmin, then run according to Hmin until the next cycle, and so on. When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down. For intermediate parameters, Select 3 to 5; if the adjusted number of cycles of the upper grate is greater than Hmax, then run according to Hmax until the next cycle, and so on.

4. The automatic feeding method based on the grate advance time according to claim 1, characterized in that: In step S4, the DCS control system sets the baseline value Lb for the number of lower grate cycles, the upper limit Lmax for the number of lower grate cycles, and the lower limit Lmin for the number of lower grate cycles. Based on the change in the upper grate's advance time, the number of lower grate cycles is adjusted as follows: When |Tq-Ts|≤Tb, the number of cycles for the lower grate remains unchanged until the next cycle, and so on. When Tq-Ts>Tb, the number of cycles for the grate is: ,in This indicates rounding down. b For intermediate parameters, b If the adjusted number of cycles for the lower grate is less than Lmin, then run according to Lmin until the next cycle, and so on. When Ts-Tq>Tb, the number of cycles for the grate is: ,in This indicates rounding down. b For intermediate parameters, b If the adjusted number of cycles for the lower grate is greater than Lmax, then run according to Lmax until the next cycle, and so on.

Images