A natural gas combustion device control system

Abstract

The present invention discloses a control system for a natural gas incineration device, relating to the technical field of natural gas incineration devices. The present invention includes a combustion-supporting air blower unit, a fuel metering pump unit, a BOG flow regulating valve unit, a control device, a hot air unit, a burner, a BOG pressure transmitter, a BOG flow transmitter, and a host computer; the control device is respectively connected to the combustion-supporting air blower, combustion-supporting air blower A, combustion-supporting air blower B, BOG flow regulating valve A, BOG flow regulating valve B, fuel switch valve, fuel switch valve A, fuel switch valve B, fuel switch valve C, hot air blower, and air heater. The natural gas incineration device control system of the present invention can implement automatic random control according to settings based on changes in BOG pressure, flow, exhaust gas temperature, and furnace pressure; it has good randomness, tracking, and accuracy. The system can ensure the normal operation of the combustion equipment when the fuel is a combustible gas, can fully burn the mixed gas, and meet exhaust emission standards.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas incineration devices, and in particular relates to a control system for a natural gas incineration device. Background Art

[0002] A Gas Combustion Unit (GCU) is a specialized device used to incinerate boil-off gas (BOG) produced during the navigation of liquefied natural gas (LNG) vessels due to delayed liquefaction and combustion. It is a critical piece of equipment required for LNG vessels. This excess BOG not only causes significant environmental pollution and waste, but also poses significant safety risks if not promptly handled. Currently, the research, development, and production of natural gas incineration units in China are still underdeveloped. Following market research and incorporating experience in burner design and production, this application proposes a control system for a natural gas incineration unit to address issues such as insufficient combustion and substandard emissions under varying BOG parameters. Summary of the Invention

[0003] The purpose of the present invention is to provide a natural gas incineration device control system, in which the air volume is automatically distributed by an induction burner according to the fuel quantity and exhaust gas temperature, the fuel and combustion-supporting air ratio is completed, sufficient combustion is achieved, the furnace temperature is controlled, and the problems of insufficient combustion and substandard emissions under variable BOG parameters are solved.

[0004] To solve the above technical problems, the present invention is achieved through the following technical solutions:

[0005] The present invention is a control system for a natural gas incineration device, comprising a combustion-supporting air unit, a fuel metering pump unit, a BOG flow regulating valve unit, a control device, a hot air unit, a burner, a BOG pressure transmitter, a BOG flow transmitter, a furnace pressure transmitter, an exhaust gas temperature transmission unit and a host computer.

[0006] The combustion-supporting air unit includes a combustion-supporting air fan, a combustion-supporting air fan A, and a combustion-supporting air fan B; the fuel metering pump group includes a fuel switch valve, a fuel switch valve A, a fuel switch valve B, and a fuel switch valve C; the hot air unit includes a hot air blower, an air heater, and an air switch valve.

[0007] The control device is respectively connected to the combustion-supporting fan, combustion-supporting fan A, combustion-supporting fan B, BOG flow regulating valve A, BOG flow regulating valve B, fuel switch valve, fuel switch valve A, fuel switch valve B, fuel switch valve C, hot air fan and air heater.

[0008] The combustion-supporting fan, combustion-supporting fan A, combustion-supporting fan B, BOG flow regulating valve A, BOG flow regulating valve B, furnace pressure transmitter, exhaust gas temperature transmission, fuel switch valve, fuel switch valve A, fuel switch valve B, fuel switch valve C, hot air fan, and air heater are connected to the burner; the BOG pressure transmitter, BOG flow transmitter, furnace pressure transmitter, exhaust gas temperature transmission, and host computer are connected to the control device.

[0009] As a preferred technical solution of the present invention, the BOG pressure signal detected by the BOG pressure transmitter serves as the primary variable of the system, and the BOG flow signal detected by the BOG flow transmitter, the pressure signal detected by the exhaust gas temperature transmitter, and the temperature signal detected by the furnace pressure transmitter serve as parameter variables. The BOG flow regulating valve A or the BOG flow regulating valve B is adjusted by the control device, and the combustion-supporting air volume is automatically distributed to the furnace by the burner structure in a quantitative manner.

[0010] As a preferred technical solution of the present invention, the combustion-supporting air units are operated in groups of two, and after a set operating time, another group is automatically switched. The control device automatically adjusts the BOG flow control valve A or BOG flow control valve B according to the load output by the control device.

[0011] As a preferred technical solution of the present invention, the burner is an induction burner, and the combustion air volume is automatically distributed to the furnace by the burner mechanical structure.

[0012] As a preferred technical solution of the present invention, the air output end of the hot air blower is connected to the air inlet end of the air heater, and the air outlet end of the air heater is connected to the burner through an air switch valve.

[0013] As a preferred technical solution of the present invention, the fuel switching valve is connected to the fuel switching valve A, the fuel switching valve B, and the fuel switching valve C respectively.

[0014] As a preferred technical solution of the present invention, information is interactively transmitted between the host computer and the control device.

[0015] As a preferred technical solution of the present invention, the BOG pressure transmitter is a gas pressure sensor, and the BOG flow transmitter is a gas flow meter.

[0016] The present invention has the following beneficial effects:

[0017] 1. The control system of the natural gas incineration device of the present invention can implement automatic random control according to the settings based on the changes in BOG pressure and flow; it has good randomness, tracking and accuracy. The air volume is automatically distributed by the induction burner according to the fuel amount and exhaust temperature to complete the ratio of fuel and combustion-supporting air. The system can realize the normal operation of the combustion equipment when the fuel is combustible gas, can fully burn the mixed gas, and meet the exhaust emission standards.

[0018] 2. When the present invention is applied to LNG ships, the BOG generated by the LNG ships and the mixed gas used in the replacement pipeline can be fully burned to make the tail gas meet the emission standards and the furnace temperature can be controlled within the required range. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative work.

[0020] Figure 1 This is a structural block diagram of a natural gas incineration device control system of the present invention.

[0021] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0022] 1-Combustion-supporting fan, 2-Fuel switch valve, 3-BOG flow control valve A, 4-BOG flow control valve B, 5-Control device, 6-Hot air fan, 7-Air heater, 8-Burner, 9-BOG pressure transmitter, 10-BOG flow transmitter, 11-Host computer, 12-Air switch valve, 13-Exhaust gas temperature transmission, 14-Furnace pressure transmitter, 15-Combustion-supporting fan A, 16-Combustion-supporting fan B, 21-Fuel switch valve A, 22-Fuel switch valve B, 23-Fuel switch valve C. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0024] Specific embodiment 1: Please refer to Figure 1As shown, the present invention is a control system for a natural gas incineration device, comprising a combustion air unit, a fuel metering pump unit, a BOG flow regulating valve unit, a control device 5, a hot air unit, a burner 8, a BOG pressure transmitter 9, a BOG flow transmitter 10, a furnace pressure transmitter 14, an exhaust gas temperature transmitter 13, and a host computer 11. The BOG pressure transmitter 9 is a gas pressure sensor, and the BOG flow transmitter 10 is a gas flow meter. Information is exchanged between the host computer 11 and the control device 5. Each pair of combustion air units operates in a group, and after a set operating time, the other group automatically switches. The control device 5 automatically adjusts the BOG flow regulating valve A3 or BOG flow regulating valve B4 based on the load output by the control device. The burner 8 is an induction burner, and the combustion air volume is automatically distributed by the burner 8 based on the flow rate through the BOG flow regulating valve A3 or BOG flow regulating valve B4 and the furnace temperature.

[0025] The combustion-supporting air unit includes combustion-supporting air fan 1, combustion-supporting air fan A15, and combustion-supporting air fan B16; the fuel metering pump group includes fuel switch valve 2, fuel switch valve A21, fuel switch valve B22, and fuel switch valve C23, and the fuel switch valve 2 is respectively connected to the fuel switch valve A21, fuel switch valve B22, and fuel switch valve C23; the hot air unit includes a hot air blower 6, an air heater 7, and an air switch valve 12.

[0026] Control device 5 is connected to combustion-supporting blower 1, combustion-supporting blower A15, combustion-supporting blower B16, BOG flow regulating valve A3, BOG flow regulating valve B4, fuel on / off valve 2, fuel on / off valve A21, fuel on / off valve B22, fuel on / off valve C23, hot air blower 6, and air heater 7. The air output end of hot air blower 6 is connected to the air inlet end of air heater 7, and the air outlet end of air heater 7 is connected to burner 8 via air on / off valve 12.

[0027] The combustion-supporting fan 1, combustion-supporting fan A15, combustion-supporting fan B16, BOG flow regulating valve A3, BOG flow regulating valve B4, furnace pressure transmitter 14, exhaust gas temperature transmission device 13, fuel oil switch valve 2, fuel oil switch valve A21, fuel oil switch valve B22, fuel oil switch valve C23, hot air blower 6, and air heater 7 are connected to the burner 8; the BOG pressure transmitter 9, BOG flow transmitter 10, furnace pressure transmitter 14, exhaust gas temperature transmission device 13, and host computer 11 are connected to the control device 5.

[0028] The BOG pressure signal detected by the BOG pressure transmitter 9 serves as the main variable of this system. The BOG flow signal detected by the BOG flow transmitter 10, the pressure signal detected by the exhaust gas temperature transmitter 13, and the temperature signal detected by the furnace pressure transmitter 14 serve as parameter variables. After adjustment by the control device 5, the BOG flow regulating valve A3 or the BOG flow regulating valve B4 is adjusted. The combustion air volume is automatically distributed to the furnace by the burner structure in a quantitative manner.

[0029] Each two combustion air units form a group and operate in combination. After the set operation time is reached, another group is automatically switched. The control device 5 automatically adjusts the BOG flow control valve A3 or BOG flow control valve B4 according to the load output by the control device.

[0030] The air output end of the hot air blower 6 is connected to the air inlet end of the air heater 7 , and the air outlet end of the air heater 7 is connected to the burner 8 through the air switch valve 12 .

[0031] A specific application of this embodiment is that the control system sets four operating modes based on the BOG supply flow and pressure: BOG mode, free flow mode, warming mode, and exhaust mode. Fuel oil is used as an auxiliary fuel and is optional.

[0032] First, host computer 11 selects one of the four aforementioned modes based on the operating conditions, with fuel as an optional option. After the natural gas combustion unit (GCU) starts, combustion-supporting fans 1 and A15 (two fans operate simultaneously as a group, automatically switching to the other group after a specified time to reduce the cumulative operating time difference between each fan) start. After leak detection passes, the main gas valve opens. If auxiliary fuel is selected, fuel valves 2, A21, B22, and C23 open simultaneously, igniting the main flame.

[0033] After normal combustion, the control system can output a load signal based on the input from the BOG pressure transmitter (gas pressure sensor) 9 and the BOG flow transmitter (gas flow meter) 10. After passing through the control device 5, the control device 5 uses a fuzzy adaptive PID control algorithm to control the valve opening of the BOG flow control valve A3 and / or BOG flow control valve B4. After the combustion-supporting fan 1 is started, it operates at the industrial frequency. The air volume is automatically distributed by the induction burner 8 according to the fuel quantity and exhaust gas temperature. The fuel and combustion-supporting air ratio is completed, achieving sufficient combustion, controlling the furnace temperature, and ensuring that the exhaust gas meets emission standards.

[0034] Specific embodiment 2: Based on the specific embodiment 1, the difference of this embodiment is that:

[0035] like Figure 1As shown, when the natural gas combustion device is not in use and the ambient temperature is low, the hot air blower 6 is started, the air switch valve 12 is opened, the air heater 7 is turned on, and the hot air blows along the pipeline to the burner 8 to prevent the burner 8 from freezing at low temperatures.

[0036] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. Schematic representations of these terms throughout this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0037] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A natural gas incineration device control system, characterized in that: include: Combustion-supporting air unit, fuel metering pump unit, BOG flow regulating valve unit, control device (5), hot air unit, burner (8), BOG pressure transmitter (9), BOG flow transmitter (10), furnace pressure transmitter (14), exhaust gas temperature transmission unit (13) and host computer (11); The combustion-supporting air unit comprises a combustion-supporting air fan (1), a combustion-supporting air fan A (15), and a combustion-supporting air fan B (16); The fuel metering pump group includes a fuel switch valve (2), a fuel switch valve A (21), a fuel switch valve B (22), and a fuel switch valve C (23); The BOG flow regulating valve group includes a BOG flow regulating valve A (3) and a BOG flow regulating valve B (4); The hot air unit includes a hot air blower (6), an air heater (7) and an air switch valve (12); The control device (5) is respectively connected to the combustion-supporting fan (1), the combustion-supporting fan A (15), the combustion-supporting fan B (16), the BOG flow regulating valve A (3), the BOG flow regulating valve B (4), the furnace pressure transmitter (14), the exhaust gas temperature transmission (13), the fuel switch valve (2), the fuel switch valve A (21), the fuel switch valve B (22), the fuel switch valve C (23), the hot air fan (6), and the air heater (7); The combustion-supporting blower (1), the combustion-supporting blower A (15), the combustion-supporting blower B (16), the BOG flow regulating valve A (3), the BOG flow regulating valve B (4), the fuel switch valve (2), the fuel switch valve A (21), the fuel switch valve B (22), the fuel switch valve C (23), the hot air blower (6), and the air heater (7) are connected to the burner (8); The BOG pressure transmitter (9), the BOG flow transmitter (10), the furnace pressure transmitter (14), the exhaust gas temperature transmission device (13), and the host computer (11) are connected to the control device (5); The BOG pressure signal detected by the BOG pressure transmitter (9) is used as the main variable of the system. The BOG flow signal detected by the BOG flow transmitter (10), the pressure signal detected by the exhaust gas temperature transmitter (13), and the temperature signal detected by the furnace pressure transmitter (14) are used as parameter variables. After adjustment by the control device (5), the BOG flow regulating valve A (3) or the BOG flow regulating valve B (4) is adjusted, and the combustion air volume is quantitatively distributed to the furnace by the burner (8) structure.

2. A natural gas combustion device control system according to claim 1, characterized in that: Every two combustion-supporting air units form a group and operate in combination. After the operation reaches a set time, another group is automatically switched. The control device (5) automatically adjusts the BOG flow control valve A (3) or the BOG flow control valve B (4) according to the load output by the control device.

3. A natural gas combustion device control system according to claim 1, characterized in that: The burner (8) is an induction burner, and the combustion-supporting air volume is automatically distributed to the furnace by the mechanical structure of the burner (8).

4. A natural gas combustion device control system according to claim 1, characterized in that: The air output end of the hot air blower (6) is connected to the air inlet end of the air heater (7), and the air outlet end of the air heater (7) is connected to the burner (8) via an air switch valve (12).

5. A natural gas combustion device control system according to claim 1, characterized in that: The fuel switch valve (2) is connected to the fuel switch valve A (21), the fuel switch valve B (22), and the fuel switch valve C (23) respectively.

6. A natural gas combustion device control system according to claim 1, characterized in that: The host computer (11) and the control device (5) perform interactive information transmission.

7. A natural gas combustion device control system according to claim 1, characterized in that: The BOG pressure transmitter (9) is a gas pressure sensor, and the BOG flow transmitter (10) is a gas flow meter.

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