A flameout detection, protection and re-ignition device for a heating furnace

Abstract

The present invention provides a flameout detection, protection and re-ignition device for a heating furnace, which relates to the technical field of heating equipment and solves the technical problem that there is no detection means for fire extinguishing in a heating furnace and it relies on manual discovery, which has hidden dangers. The flameout detection, protection and re-ignition device for a heating furnace includes a furnace body, which is provided with an air door and a chimney, a burner, an air supply assembly and a fire extinguishing monitoring assembly. There are two fire extinguishing monitoring assemblies, which are respectively installed in the premixing zone and the flame zone; it also includes a sleeve-type tee, a switching air valve and a high-pressure fan; a combustible gas sensor arranged in the chimney; a self-pressurized high-energy high-frequency igniter arranged in the furnace body near the burner and a flame stabilizer arranged in the induced draft zone. The present invention has the characteristics of safety, and can monitor in real time whether the fire in the heating furnace is extinguished and shut down the gas in time.

Description

Technical Field

[0001] The invention relates to the technical field of heating equipment, and in particular to a flameout detection, protection and re-ignition device for a heating furnace. Background Art

[0002] Oilfield heating furnaces are key equipment for increasing temperature and reducing viscosity during the gathering and transportation process. Most well station heating furnaces use oilfield associated gas (casing gas) as fuel and adopt natural ventilation mode for combustion. Figure 1 As shown, a natural ventilation heating furnace currently used in the oil field adjusts or closes the casing gas through the manual valve group 1 to adjust the gas supply of the burner 3, and adjusts the air volume through the manual damper 3 to generate a flame zone 4. The heat generated by the combustion is transmitted to the fire tube 5 by radiation and convection, and is transferred to the softened water 6 through the fire tube 5. The softened water 6 is then transferred to the heated crude oil in the tube through the coil 7, and finally the flue gas is discharged to the atmosphere through the chimney 9. The chimney needs to have a certain height to ensure natural ventilation. During operation, after the flame is turned off, the manual valve group 1 is found and closed through manual inspection, and the manual damper 3 is fully opened to purge the casing gas in the fire tube. When igniting again, a portable rechargeable high-voltage ignition gun (not marked in the figure) is manually sent into the fire tube, the manual valve group 1 and the manual damper 2 are opened, and the rechargeable high-voltage ignition gun is exited after the ignition is successful.

[0003] The applicant has found that the prior art has at least the following technical problems:

[0004] (1) The flame is easily extinguished due to the presence of light oil and water in the casing gas, strong winds, chimney blockage, etc., and frequent re-ignition is necessary; (2) After the flame is extinguished during the operation of the heating furnace, the manual air inlet valve cannot be closed in time, resulting in the presence of flammable gas in the fire tube. When re-igniting, the natural induced draft mode is adopted, and the air door is manually opened for natural ventilation before ignition. The complete discharge of the fuel in the fire tube is judged by experience, which is prone to explosion and explosion accidents, seriously affecting the personal safety of oil workers; (3) During the operation of the heating furnace, there is no The flame detection method is completely discovered by manual inspection after the fire is extinguished. If it is not discovered in time, it will lead to low inlet temperature and high wellhead back pressure, which will not only affect the production, but also increase the safety hazard of wellhead packing leakage; (4) Due to unstable gas pressure, the flame length specifications of the heating furnace frequently change, and manual flame adjustment is required. However, the manual flame adjustment method is prone to cause the heating furnace to heat up too high or too low, and the risk of packing leakage is high due to low temperature rise and high back pressure; excessive temperature rise will not only cause a large amount of natural gas waste, but also lead to dry burning of the water-vaporized smoke pipe of the water-jacketed furnace or coking of the coil of the vertical fire tube furnace, resulting in safety accidents. Summary of the invention

[0005] The purpose of the present invention is to provide a heating furnace flameout detection protection and re-ignition device to solve the technical problem that the heating furnace flameout in the prior art has no detection means and relies on manual discovery, which poses hidden dangers.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a heating furnace flameout detection protection and re-ignition device, comprising a furnace body, on which an air damper and a chimney are arranged, and also comprising a burner, an air supply assembly and a fire extinguishing monitoring assembly. The burner is fixed in the furnace body and close to the air damper position, the air supply assembly is connected to the burner pipeline, a flame zone is formed at the front side of the burner, and a gas-air premixing zone is formed at the rear side of the burner; there are two fire extinguishing monitoring assemblies, which are respectively installed in the premixing zone and the flame zone.

[0008] Based on the above technical solution, the present invention can also be improved as follows.

[0009] As a further improvement of the present invention, the two fire extinguishing monitoring components use detection methods based on different principles to judge the flameout.

[0010] As a further improvement of the present invention, the two fire extinguishing monitoring components respectively include an ion type flame probe arranged in the flame zone and an ultraviolet flame detector arranged in the premixing zone.

[0011] As a further improvement of the present invention, the air supply assembly includes an air supply pipe, an electric valve and a solenoid valve, and the electric valve and the solenoid valve are sequentially arranged on the air supply pipe.

[0012] As a further improvement of the present invention, the electric valve is a rotary stroke electric valve; and the solenoid valve is a linear stroke quick-cut solenoid valve.

[0013] As a further improvement of the present invention, it also includes a sleeve-type tee, a switching air valve and a high-pressure fan, wherein the air door, the switching air valve and the high-pressure fan are respectively connected to three ports of the sleeve-type tee.

[0014] As a further improvement of the present invention, it also includes a combustible gas sensor arranged in the chimney.

[0015] As a further improvement of the present invention, it also includes a self-pressurized high-energy high-frequency igniter arranged in the furnace body close to the burner.

[0016] As a further improvement of the present invention, it also includes a flame stabilizer arranged in the premixing zone and connected to the air door and the burner respectively, and the outline and length of the flame zone are adjusted by adjusting the amount of air mixed with the fuel gas in the flame stabilizer.

[0017] As a further improvement of the present invention, it also includes a control component, which is electrically connected to the fire extinguishing monitoring component, the air supply component, the switching air valve, the high-pressure fan, the combustible gas sensor and the high-frequency igniter.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The heating furnace flameout detection protection and re-ignition device provided by the present invention changes the natural induced draft purge to forced air supply purge, and during ignition, the forced air supply sets the purge time according to the size of the furnace, thereby fundamentally eliminating the explosion accident caused by instantaneous ignition due to natural gas accumulation in the furnace;

[0020] The flameout detection protection and re-ignition device for a heating furnace provided by the present invention can adjust the mixing ratio of air and fuel gas by installing a flame stabilizer in the premixing zone, thereby adjusting the flame profile and length, and avoiding the flame licking the fire pipe and causing a pipe explosion accident;

[0021] The heating furnace flameout detection protection and re-ignition device provided by the present invention adds a flame detector and is interlocked with the automatic gas valve group program. If there is no previous signal within 10 seconds after the flame signal disappears, the gas valve group is automatically cut off to prevent the furnace gas from accumulating after the fire is extinguished, causing the explosion accident during re-ignition.

[0022] The flameout detection protection and re-ignition device for a heating furnace provided by the present invention increases a fixed ignition device and adopts a remote control ignition method to ensure a safe distance and personal safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 It is a structural schematic diagram of a natural ventilation heating furnace in the prior art;

[0025] Figure 2 It is a structural schematic diagram of a flameout detection protection and re-ignition device for a heating furnace according to the present invention;

[0026] Figure 3 It is a schematic cross-sectional view of the split structure of the flame stabilizer and the burner in the flameout detection protection and re-ignition device of the heating furnace of the present invention;

[0027] Figure 4 The invention discloses a front view of the split structure of a flame stabilizer and a burner in the flameout detection, protection and re-ignition device for a heating furnace.

[0028] In the figure, 1, manual valve group; 2, manual air door; 3, burner; 31, flame stabilizing mouth; 4, flame zone; 5, fire tube; 6, softened water; 7, coil; 9, chimney; 10, gas supply pipe; 11, electric valve; 12, solenoid valve; 13, combustible gas sensor; 14, forced purge pipeline; 15, switching air valve; 16, blower; 17, ultraviolet flame detector; 18, high frequency igniter; 19, ion type flame probe; 20, flame stabilizer; 201, gas nozzle mounting base; 202, Lafar velocity nozzle; 2021, air inlet; 100, furnace body; 200, air door; 300, gas supply assembly; 400, fire extinguishing monitoring assembly. DETAILED DESCRIPTION

[0029] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0030] The present invention provides a flameout detection, protection and re-ignition device for a heating furnace, which combines combustible gas replacement detection and interlocking protection during ignition, flame intensity detection during operation, and rapid cutting off of the gas supply valve group after flameout and forced air supply technology to eliminate safety hazards. The device comprises a furnace body 100, on which an air damper 200 and a chimney 9 are arranged, and further comprises a burner 3, an air supply assembly 300 and a fire extinguishing monitoring assembly 400. The burner 3 is an induced-type burner fixed in the furnace body 100 and close to the air damper 200. The air supply assembly 300 is connected to the burner 3 pipeline to continuously supply gas to the burner 3. A flame zone 4 is formed in front of the burner 3, and a gas-air premixing zone is formed at the rear of the burner 3. There are two fire extinguishing monitoring assemblies 400, which are respectively installed in the premixing zone and the flame zone 4.

[0031] In the present invention, in order to ensure the stability of the fuel gas pressure, when the casing gas pressure is insufficient, the fuel gas pumped out by the oil well pumping unit can be used as the fuel gas for the heating furnace.

[0032] In order to avoid misjudgment during monitoring, the two fire extinguishing monitoring components 400 respectively use detection methods based on different principles to judge the flameout.

[0033] Specifically, the two fire extinguishing monitoring components 400 respectively include an ion type flame probe 19 arranged in the flame zone 4 and an ultraviolet flame detector 17 arranged in the premixing zone. The ion type flame probe 19 is used to monitor the temperature of the flame zone 4, and the ultraviolet flame detector 17 is used to detect the temperature of the premixing zone. When the temperatures detected by both are lower than or higher than the fire extinguishing threshold value, the gas valve group is cut off or the high frequency igniter 18 is turned off.

[0034] The present invention uses an ion flame probe 19 in the flame zone and an ultraviolet flame detector 17 in the gas-air premixing zone to redundantly select two different principle detection methods to judge flameout. After flameout, the linear quick-cut solenoid valve 12 and the rotary electric valve 11 are closed, and air is forced to be supplied for purging. The proportion of displaced combustible gas is judged by detecting the concentration of combustible gas, and the gas extracted by the up and down reciprocating stroke of the oil well pumping unit is used as the gas source stroke for self-pressurized combustion-supporting high-energy and high-frequency ignition. After flameout, the furnace is ignited and operated again, thereby avoiding the safety hazards of natural ventilation oil field heating furnaces after ignition, operation and flameout.

[0035] like Figure 2 As shown, the gas supply assembly 300 includes a gas supply pipe 10, an electric valve 11 and a solenoid valve 12, and the electric valve 11 and the solenoid valve 12 are sequentially arranged on the gas supply pipe 10. The order of the electric valve 11 and the solenoid valve 12 is fixed and cannot be reversed. When the fire extinguishing monitoring assembly 400 detects that the flame is extinguished, the control assembly controls the solenoid valve 12 to close first, and then the electric valve 11 is closed in sequence.

[0036] Furthermore, the electric valve 11 is a rotary electric valve; the solenoid valve 12 is a linear fast-cut solenoid valve. A linear fast-cut solenoid valve and a rotary electric valve overcome the problem that the simple solenoid valve is not tightly closed due to organic impurities in the oil field casing gas. The rotary electric valve can push impurities through the rotation of the valve core. The linear fast-closing technology of the solenoid valve and the rotary slow-closing technology of the electric valve can better overcome the problem that the gas valve group is not tightly closed. The electric valve 11 and the solenoid valve 12 are both existing technology products purchased from the market.

[0037] Furthermore, in order to ensure that the gas valve group is tightly closed and does not leak, an online combustible gas monitoring system can be installed at the outlet of the gas valve group, that is, at the rear of the solenoid valve 12. After the valve group is turned off, it can be determined whether it is completely closed. If it is not closed tightly, the solenoid valve 12 is closed in turn and the electric valve 11 is closed with a delayed delay using program control technology to determine whether the solenoid valve 12 or the electric valve 11 is not closed tightly.

[0038] like Figure 2 As shown, it also includes a sleeve-type tee, a switching air valve 15 and a high-pressure fan, and the air door 200, the switching air valve 15 and the high-pressure fan are respectively connected to the three ports of the sleeve-type tee. Among them, the high-pressure fan is a blower 16. The sleeve-type tee is also a forced purge pipeline 14. When it is necessary to purge the furnace, the switching air valve 15 can be closed, and the blower 16 can be used to force the inside of the furnace through the forced purge pipeline 14 and the air door 200 to force the inside of the furnace to be purged; when it is necessary to ignite natural ventilation, the blower 16 is closed, and the switching air valve 15 is opened to allow the external natural air to enter the furnace through the forced purge pipeline 14 and the air door 200 for pre-mixing of gas and air before ignition.

[0039] The present invention adopts a method that combines natural ventilation with forced purge, that is, a sleeve-type tee, a forced air supply high-pressure fan and a switching air valve are installed at the existing natural ventilation damper. When the heating furnace is running, the natural ventilation combustion method is still adopted. When igniting again, the high-pressure fan is started for purge, and the casing gas displacement rate is judged by the combustible gas concentration sensor.

[0040] like Figure 2 As shown, a combustible gas sensor 13 is also included which is arranged in the chimney 9.

[0041] It also includes a self-pressurized high-energy high-frequency igniter 18 arranged in the furnace body 100 near the burner 3. The fixed ignition device is installed and automatic ignition is adopted to overcome the accident of casualties caused by the portable ignition gun being inserted into the furnace for ignition manually and the body being too close to the ignition area and not being able to avoid the explosion in time.

[0042] It also includes a flame stabilizer 20 that is arranged in the premixing zone and is connected to the air door 200 and the burner 3 respectively. The flame stabilizer 20 is used to adjust the mixing ratio of air and gas, thereby adjusting the outline and length of the flame zone 4 formed in front of the burner 3. The flame stabilizer 20 in the present invention is a self-spinning flow-blocking flame stabilizer specially developed according to the flame characteristics of the natural air supply heating furnace in the oil field. The flame stabilizer is installed in the premixing zone to make the flame outline and length controllable, eliminating the flame licking the fire tube and causing local overheating and bursting accidents. The specific structure of the flame stabilizer 20 is as follows Figure 3 and Figure 4 As shown, it includes a gas nozzle mounting base 201 and a Rafale velocity nozzle 202. The left end of the gas nozzle mounting base 201 is connected to the damper 200 through a connecting piece, and the other end is provided with an external thread section on the outside, which is threadedly connected to the Rafale velocity nozzle 202. The gas nozzle mounting base 201 has a passage for gas circulation inside. Eight air inlets 2021 are provided on the front outer wall of the Rafale velocity nozzle 202 along the circumferential direction. The air inlet 2021 is blocked by using components to adjust the amount of air entering the nozzle, thereby adjusting the mixing ratio of gas and air. The passage for gas circulation inside the Rafale velocity nozzle 202 is a structure with large ends and small middle, so that the internal gas forms a negative pressure near the air inlet 2021, which can introduce air outside the nozzle into the interior for mixing; the structure of the burner 3 is as follows Figure 3 and Figure 4 As shown, the burner 3 is threadedly connected to the Lafarge velocity nozzle 202 through a connecting piece, and a plurality of flame stabilizing ports 31 are evenly arranged along the circumferential direction on the front side of the burner 3, and a cavity with a stepped structure is arranged inside the left side of the burner 3, and the stepped cavity is gradually reduced in size, and the right side is a hollow cylindrical structure. The flame stabilizing port 31 is located on the burner 3 at the position of the hollow cylindrical structure, and the flame stabilizing port 31 is arranged to allow external air to enter to keep the flame stable.

[0043] It also includes a control component, which is electrically connected to the fire extinguishing monitoring component 400, the air supply component 300, the switching air valve 15, the high-pressure fan, the combustible gas sensor 13 and the high-frequency igniter 18.

[0044] The specific usage is:

[0045] When the ultraviolet flame detector 17 and the ion type flame probe 19 reach the flame intensity extinguishing threshold at the same time, the valve group consisting of the electric valve 11 and the solenoid valve 12 is automatically shut down, and the residual gas in the fire tube 5 is forced to be purged by switching the air valve 15 and starting the blower 16. After the combustible gas sensor 13 detects no combustible gas, the air valve 15 is switched to the natural ventilation state, and the electric valve 11 and the solenoid valve 12 are automatically opened. The self-pressurized high-energy high-frequency igniter 18 is energized to generate an ignition fire. After the burner 3 takes in air, the ultraviolet flame detector 17 and the ion type flame probe 19 reach flame at the same time, the self-pressurized high-energy high-frequency igniter 18 loses power and stands by, the heating furnace operates normally, and the contour and length of the flame zone 4 are adjusted by the swirl generated by the flame stabilizer 20.

[0046] First of all, it should be explained here that “inward” refers to the direction toward the center of the accommodating space, and “outward” refers to the direction away from the center of the accommodating space.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate directions or positional relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0052] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A heating furnace flameout detection protection and re-ignition device, characterized in that: It comprises a furnace body, on which an air door and a chimney are arranged, and also comprises a burner, an air supply assembly and a fire extinguishing monitoring assembly, wherein the burner is fixed in the furnace body and close to the air door, the air supply assembly is connected with the burner pipeline, a flame zone is formed in front of the burner, and a gas-air premixing zone is formed in the rear of the burner; there are two fire extinguishing monitoring assemblies, which are respectively installed in the premixing zone and the flame zone; The air supply assembly comprises an air supply pipe, an electric valve and a solenoid valve, wherein the electric valve and the solenoid valve are sequentially arranged on the air supply pipe; The electric valve is a rotary stroke electric valve; the solenoid valve is a linear stroke quick-cut solenoid valve; It also includes a flame stabilizer disposed in the premixing zone and connected to the air door and the burner respectively, and the profile and length of the flame zone are adjusted by adjusting the amount of air mixed with the fuel gas in the flame stabilizer; The flame stabilizer includes a gas nozzle mounting base and a Rafale velocity nozzle, the left end of the gas nozzle mounting base is connected to the damper through a connecting piece, and the other end is provided with an external thread section on the outside, which is threadedly connected to the Rafale velocity nozzle, and the inside of the gas nozzle mounting base has a passage for gas circulation, and 8 air inlets are provided on the front outer wall of the Rafale velocity nozzle in a circumferential direction. The air inlets are blocked by using components to adjust the amount of air entering the Rafale velocity nozzle, and the burner is threadedly connected to the Rafale velocity nozzle through a connecting piece, and a plurality of flame stabilizing ports are evenly arranged in the circumferential direction on the front side of the burner, and a cavity with a stepped structure is provided inside the left side of the burner, and the stepped cavity is gradually reduced in size, and the right side is a hollow cylindrical structure, and the flame stabilizing port is located on the burner at the position of the hollow cylindrical structure.

2. The heating furnace flameout detection protection and re-ignition device according to claim 1 is characterized in that: The two fire extinguishing monitoring components use detection methods based on different principles to judge fire extinguishing.

3. The heating furnace flameout detection protection and re-ignition device according to claim 2 is characterized in that: The two fire extinguishing monitoring components respectively include an ion type flame probe arranged in the flame zone and an ultraviolet flame detector arranged in the premixing zone.

4. The heating furnace flameout detection protection and re-ignition device according to any one of claims 1 to 3, characterized in that: It also includes a sleeve-type three-way connection, a switching air valve and a high-pressure fan, wherein the air door, the switching air valve and the high-pressure fan are respectively connected to three ports of the sleeve-type three-way connection.

5. The heating furnace flameout detection protection and re-ignition device according to claim 4, characterized in that: Also included is a combustible gas sensor disposed in the chimney.

6. The heating furnace flameout detection protection and re-ignition device according to claim 5, characterized in that: It also includes a self-pressurized high-energy high-frequency igniter arranged in the furnace body close to the burner.

7. The heating furnace flameout detection protection and re-ignition device according to claim 6, characterized in that: It also includes a control component, which is electrically connected to the fire extinguishing monitoring component, the air supply component, the switching air valve, the high-pressure fan, the combustible gas sensor and the high-frequency igniter.

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