Pulse control system and method for automatically changing high-fire power without changing high-fire air volume

Abstract

The present invention discloses a pulse control system and method for automatically changing the high-fire power without changing the high-fire air volume, including a combustion system and a combustion monitoring system, wherein the combustion system includes a burner, a gas main pipeline and an air main pipeline, the burner is located in a furnace, the gas main pipeline is connected to the gas interface of the burner, the air main pipeline is connected to the air interface of the burner, an air-fuel ratio valve is provided on the gas main pipeline, an air conditioning component is provided on the air main pipeline, the air-fuel ratio valve is connected to the air main pipeline and the connection point is located between the air conditioning component and the burner, and is characterized in that it also includes a pressure regulating pipeline system, a current limiting ratio valve connected to the pressure regulating pipeline system is provided on the gas main pipeline, and the current limiting ratio valve is located between the air-fuel ratio valve and the burner. The present invention can ensure that the high-fire power under the pulse combustion condition can be flexibly changed without changing the air volume corresponding to the rated power of the burner.

Description

Technical Field

[0001] The invention relates to the technical field of burners, and in particular to a pulse control system and a method for automatically changing high-fire power while keeping high-fire air volume unchanged. Background Art

[0002] In some heat treatment furnaces, pulse combustion control is a common heating solution to enhance the air flow agitation in the furnace and obtain better furnace temperature uniformity. For the pulse control system of open flame heating, the typical pipeline configuration scheme is as follows: Figure 3 As shown, the control system controls the opening time of the high-fire cut-off valve and the low-fire cut-off valve on the air pipeline to meet the heat demand of the furnace. Once the above pulse control system is debugged, its high-fire power is basically constant. If the heat demand of the furnace is small, the opening time of the high-fire cut-off valve on the air pipeline is very short, and the burner is in the low-fire state most of the time. At the same time, the ratio of gas and air in this proportional valve control form is certain. When the burner is in the low-fire stage, the gas volume and air volume are very small, the burner outlet flow rate is very low, and the stirring effect on the furnace atmosphere is very weak. Therefore, this pulse combustion will face great challenges to the uniformity of furnace temperature when the heat demand of the furnace is small. In actual applications, the heat demand of the same furnace varies greatly under different working conditions, such as multi-purpose furnaces and some furnaces with controlled cooling speed. Summary of the invention

[0003] The purpose of the present invention is to provide a pulse control system and method for automatically changing the high-fire power without changing the high-fire air volume, so as to solve the problem of furnace temperature uniformity of the pulse combustion system under the condition that the furnace heat demand varies greatly.

[0004] In order to solve the above technical problems, the present invention adopts the following solutions:

[0005] A pulse control system that automatically changes high-fire power while keeping the amount of high-fire air unchanged comprises a combustion system and a combustion monitoring system, wherein the combustion system comprises a burner, a gas main pipeline and an air main pipeline, the burner is located in a furnace, the gas main pipeline is connected to the gas interface of the burner, the air main pipeline is connected to the air interface of the burner, an air-fuel ratio valve is provided on the gas main pipeline, an air regulating component is provided on the air main pipeline, the combustion monitoring system can send pulse switch control signals to the air regulating component and the air-fuel ratio valve, the air-fuel ratio valve is connected to the air main pipeline and the connection point is located between the air regulating component and the burner, and further comprises a pressure regulating pipeline system, a flow limiting ratio valve connected to the pressure regulating pipeline system is provided on the gas main pipeline, and the flow limiting ratio valve is located between the air-fuel ratio valve and the burner.

[0006] Compared with the prior art, the prior art controls the opening time of the high-fire cut-off valve and the low-fire cut-off valve on the air pipeline through a control system to meet the heat demand of the furnace, while this pulse control system, once debugged, its high-fire power is basically constant. If the heat demand of the furnace is small, the opening time of the high-fire cut-off valve on the air pipeline is very short, and the burner is in a low-fire state most of the time. At the same time, the ratio of gas to air in this proportional valve control form is certain. When the burner is in the low-fire stage, the gas volume and air volume are very small, the burner outlet flow rate is very low, and the stirring effect on the furnace atmosphere is very weak. In this solution, a pressure regulating pipeline system and a flow limiting proportional valve are added. The pressure regulating pipeline system is used to adjust the incoming air pressure, and the flow limiting proportional valve is used to adjust the gas flow input to the burner. The air-fuel proportional valve automatically adjusts the size of the opening according to the air pressure in the pressure regulating pipeline system, thereby changing the amount of gas passing through. The air regulating component is used to adjust the flux of air entering the burner. When the heat demand of the furnace is relatively small, the system hopes to reduce the high-fire power while maintaining the corresponding air volume under the rated power to ensure a relatively large burner outlet speed and enhance the disturbance in the furnace. At this time, the pressure regulating pipeline system adjusts the air pressure in the pipeline to reduce, causing the feedback pressure of the flow limiting proportional valve to reduce, thereby making the gas flow through it very small. If the control system gives a high-fire command, the air regulating component adjusts the amount of air entering the burner to increase, the pressure in the pipeline increases, and the air-fuel proportional valve is at a higher air feedback pressure. It is in a fully open state under the pressure, but the flow rate of the limiting proportional valve downstream of the air-fuel proportional valve is reduced and the gas resistance is increased, resulting in the gas flow entering the burner at this time being less than the rated flow corresponding to the high fire of the burner, thereby reducing the combustion power of the burner, and achieving the effect of automatically changing the high fire power under the condition of unchanged high fire air volume. If the control system gives a low fire command, the air intake amount adjusted by the air regulating component is very small, the pressure downstream of the air regulating component is low, the opening of the air-fuel proportional valve becomes very small under a lower air feedback pressure, and the gas flow flowing through the gas proportional valve is very small. Since the gas flow is too small, the resistance of the limiting proportional valve to the very small flow of gas is very small, thereby having very little effect on the low fire power of the system. In this way, under the pulse combustion state, it can be ensured that the high fire power under the pulse combustion condition can be flexibly changed without changing the air volume corresponding to the rated power of the burner.

[0007] Preferably, the pressure regulating pipeline system includes a flow-limiting air pipe, a pressure regulating valve and a flow-limiting air cut-off valve. One end of the flow-limiting air pipe is connected to a combustion-supporting blower, and the other end is connected to the atmosphere through the pressure regulating valve and the flow-limiting air cut-off valve. The flow-limiting proportional valve is connected to the flow-limiting air pipe, and the connection point is located on the pipeline at the inlet of the pressure regulating valve. The combustion-supporting blower is used to provide a large amount of compressed air, and the pressure regulating valve is used to relieve the pressure of the flow-limiting air pipe. The larger the opening of the pressure regulating valve, the greater the pressure relief, and the lower the feedback pressure of the flow-limiting proportional valve, so that its opening becomes lower, thereby less gas passes through, and vice versa.

[0008] Preferably, the air conditioning assembly includes a low-fire air cut-off valve and a high-fire air cut-off valve, which are connected in parallel to the main air pipeline. The low-fire air cut-off valve is used to allow a small amount of air to pass through, and the high-fire air cut-off valve is used to allow a large amount of air to pass through.

[0009] Preferably, a gas shut-off valve is provided on the gas main pipeline, and the gas shut-off valve is located on the pipeline at the inlet of the air-fuel ratio valve. The gas shut-off valve is used to block or conduct whether the gas enters the burner.

[0010] Preferably, a plurality of gas branch pipes are connected in parallel on the gas main pipeline, and a plurality of air branch pipes corresponding to the gas branch pipes are connected in parallel on the air main pipeline, each corresponding gas branch pipe and air branch pipe are respectively connected to the gas interface and air interface of the same burner, each gas branch pipe is sequentially provided with a gas shut-off valve, an air-fuel ratio valve and a current limiting ratio valve, each air branch pipe is provided with an air regulating assembly, the air-fuel ratio valve on each gas branch pipe is connected to the corresponding air branch pipe and the connection point is located between the air regulating assembly and the burner, and the current limiting ratio valve on each gas branch pipe is respectively connected to the pressure regulating pipeline system.

[0011] Preferably, a temperature control area is provided in the furnace for detecting the combustion conditions of the corresponding burners of the gas main pipeline, gas branch pipe, air main pipeline and air branch pipe. The temperature control area is used to detect the combustion conditions of the corresponding burners on each main pipeline and branch pipe in real time to avoid safety accidents.

[0012] The pulse control method for automatically changing the high-fire power without changing the high-fire air volume is applied to the pulse control system. When the furnace heat demand is relatively small, the system hopes to reduce the high-fire power while maintaining the corresponding air volume under the rated power. The flow-limiting air shut-off valve is opened, the pressure regulating valve is opened to an appropriate opening and the flow-limiting air pipe is depressurized. The feedback pressure of the flow-limiting proportional valve is reduced, causing the opening of the flow-limiting proportional valve to become smaller. If the control system gives a high-fire command, the air high-fire shut-off valve is opened and the air low-fire shut-off valve is closed, causing the pressure downstream of the air shut-off valve to be higher. The air-fuel proportional valve is in a fully open state under a higher air feedback pressure. Since the opening of the flow-limiting proportional valve downstream of the air-fuel proportional valve becomes smaller, the resistance increases, so that the gas flow entering the burner at this time is less than the rated flow corresponding to the high-fire of the burner.

[0013] Preferably, if the control system gives a low fire command, the air high fire cut-off valve is disconnected and the air low fire cut-off valve is opened. The pressure downstream of the air cut-off valve is low, and the opening of the air-fuel ratio valve becomes very small under a lower air feedback pressure. The gas flow rate flowing through the air-fuel ratio valve is small. Due to the small gas flow rate, the flow limiting ratio valve has a small resistance to the small flow of gas, which has little impact on the low fire power of the system.

[0014] The present invention has the beneficial effects:

[0015] 1. By adding a current limiting proportional valve and a current limiting air pipe (including a pressure regulating valve and a current limiting air cut-off valve) to the conventional pulse control pipeline, it is possible to flexibly change the high fire power under pulse combustion conditions without changing the air volume corresponding to the rated power of the burner.

[0016] 2. Add a pressure regulating valve and a current limiting air cut-off valve at the end of the current limiting air pipe. Under the pulse combustion state, when the burner needs rated power at high fire, the current limiting air cut-off valve can be closed; when the burner needs to reduce the power of high fire, open the current limiting air cut-off valve, and then adjust the opening of the pressure regulating valve to achieve it.

[0017] 3. By reducing the high-fire power corresponding to the burner while ensuring that the high-fire combustion air volume remains unchanged, the pulse control system can extend the working time of the high-fire under conditions where the furnace heat demand is small, ensuring a higher burner outlet speed under high-fire conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention;

[0019] Figure 2 It is a structural schematic diagram of Example 2;

[0020] Figure 3 It is a schematic diagram of the structure of an existing pulse control system in the background technology.

[0021] Figure markings: 1-gas shut-off valve, 2-air-fuel ratio valve, 3-current limiting ratio valve, 4-air low-fire shut-off valve, 5-air high-fire shut-off valve, 6-current limiting air pipe, 7-pressure regulating valve, 8-current limiting air shut-off valve, 9-burner, 10-combustion-supporting fan, 11-gas main pipeline, 12-air main pipeline, 13-gas branch pipe, 14-air branch pipe. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0023] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "longitudinal", "lateral", "horizontal", "inside", "outside", "front", "back", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed", "opened", "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Example 1

[0026] like Figure 1As shown, a pulse control system for automatically changing the high-fire power without changing the high-fire air volume includes a combustion system and a combustion monitoring system. The combustion system includes a burner 9, a gas main pipeline 11 and an air main pipeline 12. The burner 9 is located in the furnace. The gas main pipeline 11 is connected to the gas interface of the burner 9. One end of the air main pipeline 12 is connected to the air interface of the burner 9, and the other end can also be connected to a combustion-supporting fan 10. The gas main pipeline 11 is provided with an air-fuel ratio valve 2, and the air main pipeline 12 is provided with an air conditioning component. The air conditioning component includes an air The small fire cut-off valve 4 and the air large fire cut-off valve 5, the air-fuel ratio valve 2 are connected to the air main pipeline 12 through the pressure pipe and the connection point is located between the air conditioning assembly and the burner 9, and also include a pressure regulating pipeline system, the pressure regulating pipeline system includes a flow-limiting air pipe 6, a pressure regulating valve 7 and a flow-limiting air cut-off valve 8, one end of the flow-limiting air pipe 6 is connected to the combustion-supporting fan 10, and the other end is connected to the atmosphere through the pressure regulating valve 7 and the flow-limiting air cut-off valve 8, the flow-limiting ratio valve is connected to the flow-limiting air pipe 6 and the connection point is located on the pipeline at the inlet of the pressure regulating valve 7. The combustion-supporting fan 10 is used to provide a large amount of compressed air, and the pressure regulating valve 7 is used to relieve the pressure of the flow-limiting air pipe 6. The larger the opening of the pressure regulating valve 7, the greater the pressure relief, and the lower the feedback pressure of the flow-limiting ratio valve 3, the lower its opening becomes, so that the amount of gas passing through is less, and vice versa. A current limiting proportional valve 3 connected to the pressure regulating pipeline system is provided on the gas main pipeline 11. The feedback pressure of the current limiting proportional valve 3 changes with the change of the air pressure on the current limiting air pipe 6, so that the opening of the current limiting proportional valve 3 changes accordingly, so that the gas flow changes accordingly, so as to achieve the effect of changing the power of the burner 9. The current limiting proportional valve is located between the air-fuel proportional valve 2 and the burner 9. The combustion monitoring system can send pulse switch control signals to the air conditioning component and the air-fuel proportional valve 2. The combustion monitoring system is composed of detection elements and control software and hardware. The detection elements include thermocouples for measuring furnace temperature, infrared thermometers, pressure transmitters (i.e., pressure gauges) for measuring furnace pressure, residual oxygen analyzers, laser detectors, motor encoders, and control units. The control software includes temperature control programs, furnace pressure control programs, flow control programs, PLC control programs, etc. The air conditioning components and the air-fuel proportional valve 2 can be connected to the control unit through cables.

[0027] In this embodiment, it is realized by adding a flow-limiting proportional valve 3 and a flow-limiting air pipe 6. The air feedback pressure of the flow-limiting proportional valve 3 comes from the flow-limiting air pipe 6. One end of the flow-limiting air pipe 6 is connected to the outlet of the combustion-supporting fan 10, and the other end is connected to the atmosphere through a pressure regulating valve 7 and a flow-limiting air cut-off valve 8. When the heat demand of the furnace is relatively small, the system expects to reduce the high-fire power while maintaining the corresponding air volume under the rated power, ensuring a relatively large burner 9 outlet speed and enhancing the disturbance in the furnace. The specific method is: open the flow-limiting air cut-off valve 8, open the pressure regulating valve 7 to a certain opening, release the pressure of the flow-limiting air pipe 6, reduce the feedback pressure of the flow-limiting proportional valve 3, and reduce the opening of the flow-limiting proportional valve 3. Under this operating condition, if the control system gives a high-fire instruction, the air high-fire cut-off valve 5 is opened, the air low-fire cut-off valve 4 is closed, the pressure downstream of the air cut-off valve is relatively high, and the air-fuel ratio valve 2 is in a fully open state under a relatively high air feedback pressure. However, since the opening of the flow-limiting ratio valve 3 downstream of the air-fuel ratio valve 2 becomes smaller, the resistance increases, resulting in the gas flow entering the burner 9 at this time being less than the rated flow corresponding to the high-fire of the burner 9 (the specific flow value depends on the opening of the pressure regulating valve 7. The larger the opening, the greater the pressure relief, the lower the feedback pressure of the flow-limiting ratio valve 3, the smaller the opening of the flow-limiting ratio valve 3 becomes, and the smaller the flow through the flow-limiting ratio valve 3, and vice versa); if the control system gives a low-fire instruction, the air high-fire cut-off valve 5 is disconnected, the air low-fire cut-off valve 4 is opened, the pressure downstream of the air cut-off valve is relatively low, the opening of the air-fuel ratio valve 2 becomes very small under a relatively low air feedback pressure, and the gas flow through the air-fuel ratio valve 2 is very small. Since the gas flow is too small, the resistance of the flow-limiting ratio valve 3 to the very small flow of gas is very small, thereby having very little effect on the low-fire power of the system. In this way, by adding a flow-limiting proportional valve 3 and a flow-limiting air pipe 6 (including a pressure regulating valve 7 and a flow-limiting air shut-off valve 8) to the conventional pulse control pipeline, it is possible to ensure that the high-fire power under the pulse combustion condition can be flexibly changed without changing the air volume corresponding to the rated power of the burner 9. In the pulse combustion state, when the burner 9 needs the rated power for high fire, the flow-limiting air shut-off valve 8 can be closed; when the high-fire power of the burner 9 needs to be reduced, the flow-limiting air shut-off valve 8 is opened, and then the opening of the pressure regulating valve 7 is adjusted to achieve this. By reducing the high-fire power corresponding to the burner 9 while ensuring that the high-fire combustion-supporting air volume remains unchanged, the pulse control system can extend the working time of the high-fire under conditions where the furnace heat demand is small, thereby ensuring a higher burner 9 outlet speed under high-fire conditions.

[0028] Specifically, a gas shut-off valve 1 is provided on the gas main pipeline 11 . The gas shut-off valve 1 is located on the pipeline at the inlet of the air-fuel ratio valve 2 . The gas shut-off valve 1 is used to block or conduct the gas from entering the burner 9 .

[0029] Example 2

[0030] like Figure 2As shown, a plurality of gas branch pipes 13 are connected in parallel on the gas main pipe 11, and a plurality of air branch pipes 14 corresponding to the gas branch pipes 13 are connected in parallel on the air main pipe 12. For example, the No. 2 gas branch pipe 13 corresponds to the No. 2 air branch pipe 14. Each corresponding gas branch pipe 13 and air branch pipe 14 are respectively connected to the gas interface and the air interface of the same burner 9, that is, the No. 2 gas branch pipe 13 and the No. 2 air branch pipe 14 are connected to the No. 2 burner 9. In this way, a plurality of burners 9 can be arranged in the furnace. A gas shut-off valve 1, an air-fuel ratio valve 2 and a flow limiting ratio valve 3 are sequentially arranged on each gas branch pipe 13. An air conditioning component is arranged on each air branch pipe 14. The air-fuel ratio valve 2 on each gas branch pipe 13 is connected to the corresponding air branch pipe 14 and the connection point is located between the air conditioning component and the burner 9. The flow limiting ratio valve 3 on each gas branch pipe 13 is respectively connected to the pressure regulating pipeline system.

[0031] Specifically, a temperature control area is provided in the furnace for detecting the combustion conditions of the corresponding burners 9 of the gas main pipeline 11, the gas branch pipe 13, the air main pipeline 12 and the air branch pipe 14. The temperature control area is used to detect the combustion conditions of the corresponding burners 9 on each main pipeline and branch pipeline in real time to avoid safety accidents.

[0032] Example 3

[0033] A pulse control method for automatically changing high-fire power without changing high-fire air volume, the method is applied to the pulse control system. First, when the furnace heat demand is relatively small, the system expects to reduce the high-fire power while maintaining the corresponding air volume under rated power, open the flow-limiting air shut-off valve 8, open the pressure regulating valve 7 to an appropriate opening and release the pressure on the flow-limiting air pipe 6, the feedback pressure of the flow-limiting proportional valve 3 is reduced, so that the opening of the flow-limiting proportional valve 3 becomes smaller. If the control system gives a high-fire command, the air high-fire shut-off valve 5 is opened and the air low-fire shut-off valve 4 is closed, so that the pressure downstream of the air shut-off valve is higher, and the air-fuel proportion valve 2 is in a fully open state under a higher air feedback pressure. Since the opening of the flow-limiting proportional valve 3 downstream of the air-fuel proportion valve 2 becomes smaller, the resistance increases, so that the gas flow entering the burner 9 at this time is less than the rated flow corresponding to the high-fire of the burner 9.

[0034] If the control system gives a low fire command, the air high fire cut-off valve 5 is disconnected and the air low fire cut-off valve 4 is opened. The pressure downstream of the air cut-off valve is low, and the opening of the air-fuel ratio valve 2 becomes very small under the lower air feedback pressure. The gas flow rate flowing through the air-fuel ratio valve 2 is small. Due to the small gas flow rate, the flow limiting ratio valve 3 has a small resistance to the small flow of gas, which has little impact on the low fire power of the system.

[0035] The working principle of this method is as follows: when the burner 9 receives the ignition command, the gas shut-off valve 1 is opened, the air high-fire shut-off valve 5 is closed, the air low-fire shut-off valve 4 is opened, the current-limiting air shut-off valve 8 is in a closed state, and the feedback pressure obtained by the current-limiting pressure regulating valve is the outlet pressure of the fan. Since the outlet pressure of the fan is relatively high, the current-limiting pressure regulating valve is in a fully open state, and the low-fire combustion-supporting air pressure in front of the burner 9 is fed back to the air-fuel ratio valve 2 to form a gas volume corresponding to the low-fire, which flows through the fully-open current-limiting ratio valve 3 into the burner 9 to mix with the low-fire air and ignite to form a low-fire flame.

[0036] When a high fire with rated power is required, the air high fire cut-off valve 5 is opened, the air low fire cut-off valve 4 is closed (some systems will also keep the low fire cut-off valve open, or even replace the low fire cut-off valve with a manual fine adjustment valve), the flow-limiting air cut-off valve 8 is closed, the feedback pressure obtained by the flow-limiting pressure regulating valve is still the outlet pressure of the fan, the flow-limiting pressure regulating valve is in the fully open state, and the high fire combustion-supporting air pressure in front of the burner 9 is fed back to the air-fuel ratio valve 22 to form a gas volume corresponding to the high fire rated power, which flows through the fully open flow-limiting ratio valve 3 into the burner 9 to mix with the high fire air and burn to form a high fire flame. Once the burner 9 is ignited, the control system can be used to control the opening and closing of the air high fire cut-off valve 5 and the air low fire cut-off valve 4 to achieve the alternating rotation of the large and small fires of the burner 9 and realize pulse combustion.

[0037] When the furnace heat demand is relatively small, the system expects to reduce the high fire power while maintaining the corresponding air volume under the rated power, ensuring a relatively large burner 9 outlet velocity and enhancing the disturbance in the furnace. The specific method is: open the flow-limiting air cut-off valve 8, open the pressure regulating valve 7 to a certain opening, release the pressure of the flow-limiting air pipe 6, reduce the feedback pressure of the flow-limiting proportional valve 3, and reduce the opening of the flow-limiting proportional valve 3. Under this operating condition, if the control system gives a high fire command, the air high fire cut-off valve 5 opens, the air low fire cut-off valve 4 closes, the pressure downstream of the air cut-off valve is relatively high, and the air-fuel ratio valve 2 is in a fully open state under the higher air feedback pressure. However, since the opening of the flow limiting ratio valve 3 downstream of the air-fuel ratio valve 2 becomes smaller, the resistance increases, resulting in the gas flow entering the burner 9 at this time being less than the rated flow corresponding to the high fire of the burner 9; if the control system gives a low fire command, the air high fire cut-off valve 5 is disconnected, the air low fire cut-off valve 4 is opened, and the pressure downstream of the air cut-off valve is relatively low. The opening of the air-fuel ratio valve 2 becomes very small under the lower air feedback pressure, and the gas flow passing through the air-fuel ratio valve 2 is very small. Since the gas flow is too small, the flow limiting ratio valve 3 has very small resistance to the very small flow of gas, which has very little effect on the low fire power of the system.

[0038] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. According to the technical essence of the present invention, within the spirit and principles of the present invention, any simple modification, equivalent replacement and improvement made to the above embodiment still falls within the protection scope of the technical solution of the present invention.

Claims

1. A pulse control system for automatically changing the high-fire power without changing the high-fire air volume, comprising a combustion system and a combustion monitoring system, wherein the combustion system comprises a burner (9), a gas main pipeline (11) and an air main pipeline (12), wherein the burner (9) is located in a furnace, the gas main pipeline (11) is connected to the gas interface of the burner (9), the air main pipeline (12) is connected to the air interface of the burner (9), the gas main pipeline (11) is provided with an air-fuel ratio valve (2), the air main pipeline (12) is provided with an air conditioning component, the combustion monitoring system can send a pulse switch control signal to the air conditioning component and the air-fuel ratio valve (2), the air-fuel ratio valve (2) is connected to the air main pipeline (12) and the connection point is located between the air conditioning component and the burner (9), and the burner (9) is characterized in that: It also includes a pressure regulating pipeline system, wherein a flow limiting proportional valve (3) connected to the pressure regulating pipeline system is provided on the gas main pipeline (11), and the flow limiting proportional valve (3) is located between the air-fuel proportional valve (2) and the burner (9); The pressure regulating pipeline system comprises a flow-limiting air pipe (6), a pressure regulating valve (7) and a flow-limiting air shut-off valve (8); one end of the flow-limiting air pipe (6) is connected to a combustion-supporting fan (10), and the other end is connected to the atmosphere through the pressure regulating valve (7) and the flow-limiting air shut-off valve (8); the flow-limiting proportional valve (3) is connected to the flow-limiting air pipe (6), and the connection point is located on the pipeline at the inlet of the pressure regulating valve (7); The air conditioning assembly comprises an air low-fire cut-off valve (4) and an air high-fire cut-off valve (5), and the air low-fire cut-off valve (4) and the air high-fire cut-off valve (5) are connected in parallel to the air main pipeline (12).

2. The pulse control system for automatically changing the high-fire power without changing the high-fire air volume according to claim 1 is characterized in that: The main gas pipeline (11) is provided with a gas shut-off valve (1), which is located on the pipeline at the inlet of the air-fuel ratio valve (2).

3. The pulse control system for automatically changing the high-fire power without changing the high-fire air volume according to claim 1 is characterized in that: The gas main pipe (11) is connected in parallel to a plurality of gas branch pipes (13), and the air main pipe (12) is connected in parallel to a plurality of air branch pipes (14) corresponding to the gas branch pipes (13). Each of the mutually corresponding gas branch pipes (13) and air branch pipes (14) is respectively connected to the gas interface and the air interface of the same burner (9). Each gas branch pipe (13) is provided with a gas shut-off valve (1), an air-fuel ratio valve (2) and a flow limiting ratio valve (3) in sequence. Each air branch pipe (14) is provided with an air conditioning component. The air-fuel ratio valve (2) on each gas branch pipe (13) is connected to the corresponding air branch pipe (14), and the connection point is located between the air conditioning component and the burner (9). The flow limiting ratio valve (3) on each gas branch pipe (13) is respectively connected to the pressure regulating pipeline system.

4. The pulse control system for automatically changing the high-fire power without changing the high-fire air volume according to claim 1 is characterized in that: A temperature control zone is provided in the furnace for detecting the combustion conditions of the corresponding burners (9) of the gas main pipeline (11), the gas branch pipeline (13), the air main pipeline (12) and the air branch pipeline (14).

5. A pulse control method for automatically changing the high-fire power without changing the high-fire air volume, applied to a pulse control system as claimed in any one of claims 1 to 4, characterized in that: When the heat demand of the furnace is relatively small, the system hopes to reduce the high-fire power while maintaining the corresponding air volume under the rated power, open the flow-limiting air shut-off valve (8), open the pressure regulating valve (7) to an appropriate opening and release the pressure on the flow-limiting air pipe (6), and reduce the feedback pressure of the flow-limiting proportional valve (3) so that the opening of the flow-limiting proportional valve (3) becomes smaller. If the control system issues a high-fire command, the air high-fire shut-off valve (5) is opened and the air low-fire shut-off valve (4) is closed, so that the pressure downstream of the air shut-off valve is higher, and the air-fuel proportion valve (2) is in a fully open state under the higher air feedback pressure. Since the opening of the flow-limiting proportional valve (3) downstream of the air-fuel proportion valve (2) becomes smaller, the resistance increases, so that the gas flow entering the burner (9) at this time is less than the rated flow corresponding to the high-fire of the burner (9); If the control system issues a low-fire command, the high-fire air shut-off valve (5) is disconnected and the low-fire air shut-off valve (4) is opened. The pressure downstream of the air shut-off valve is low, and the opening of the air-fuel ratio valve (2) becomes very small under the low air feedback pressure. The gas flow rate flowing through the air-fuel ratio valve (2) is small. Due to the small gas flow rate, the resistance of the flow-limiting ratio valve (3) to the small gas flow rate is small, so that the impact on the low-fire power of the system is small.

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