Pneumatic fuel gas premixing valve and fuel gas device

Abstract

The pneumatic type fuel gas premixing valve comprises a valve body, the valve body is provided with a fuel gas inlet and a fuel gas outlet, the inner side of the fuel gas inlet is sequentially provided with a first cavity, a control cavity and a gas outlet cavity, opening and closing between the first cavity and the control cavity are controlled through a first electromagnetic valve, and adjusting valves are arranged on the control cavity and the gas outlet cavity; a first branch communicated with the control cavity is arranged between the control cavity and the adjusting valve, a servo valve is arranged on the air outlet cavity and comprises a second diaphragm, the second diaphragm and the valve body form a second diaphragm cavity, a second branch is arranged between the first diaphragm cavity and the second diaphragm cavity, and the opening and closing and the opening degree of the second branch and the air outlet cavity are controlled through a second valve plug. By means of branch linkage of the first diaphragm cavity and the second diaphragm cavity and cooperation of the servo valve and the adjusting valve, the opening degree can be dynamically adjusted according to gas inlet pressure and air pipeline pressure. And the gas-air pressure difference is compensated in real time, so that the stability of the air-fuel ratio is ensured, and the problem of insufficient combustion or backfire is avoided.

Description

Technical Field

[0001] The present invention relates to a gas valve, especially a gas valve for gas. Background Art

[0002] During the use of a gas water heater, it entirely depends on the solenoid valve for adjustment and control. However, when the gas pressure and the intake pressure change, the existing regulating valve cannot automatically perform linkage adjustment using the pressure difference between the outlet pressure and the intake pressure, resulting in corresponding changes in the combustion conditions of the combustion chamber. Secondly, complex calculation logics are required for adjustment. Due to the changing gas pressure and the intake pressure of the combustion-supporting air in the existing gas valve body, it is very difficult to coordinate the mixing ratio of air and gas, the combustion ratio is unreasonable, and there is a lot of waste gas. Therefore, there is an urgent need for a gas valve that can actively adjust the ratio of combustion-supporting air to gas. Summary of the Invention

[0003] To solve the above deficiencies of the existing gas valve, the present invention provides a pneumatic gas premixing valve, which actively adjusts the valve body relying on the pressure difference between the intake pressure and the outlet pressure to meet the requirements of the set outlet pressure or flow rate value.

[0004] The technical solution adopted by the present invention is: a pneumatic gas premixing valve, including a valve body, the valve body is provided with a gas intake port and a gas outlet port. Inside the gas intake port, there are successively a first cavity, a control cavity, and an outlet cavity. The first cavity and the control cavity are controlled to open and close by a first solenoid valve. A regulating valve is provided on the control cavity and the outlet cavity; there is a first branch connected between the control cavity and the regulating valve. The regulating valve includes a first diaphragm, a first valve stem and a first valve plug are arranged on the first diaphragm. There is a first diaphragm cavity outside the first diaphragm, and the first branch is connected to the first diaphragm cavity; a slave valve linked to the first solenoid valve is provided on the first branch. The regulating valve controls the opening and closing and the opening degree of the valve body through the pressure in the first diaphragm cavity; a servo valve is provided on the outlet cavity. The servo valve includes a second diaphragm, a second valve stem and a second valve plug are arranged on the second diaphragm. The second diaphragm and the valve body form a second diaphragm cavity. There is a second branch between the first diaphragm cavity and the second diaphragm cavity. The second branch and the outlet cavity are controlled to open and close and the opening degree by the second valve plug. A cover plate is provided on the sealing cover of the valve body, and the first diaphragm cavity is formed by the cover plate and the first diaphragm.

[0005] The valve body further includes a base and a pressing plate covering the base. A sealing gasket is arranged between the pressing plate and the base; the first valve body, the second valve body and the servo valve are arranged on the pressing plate. The sealing and fixing of the first valve body, the second valve body and the pressing plate are conventional technical means in the art and will not be elaborated here again.

[0006] Further, as one of the preferred solutions of a pneumatic gas premixing valve, the valve body is composed of a solenoid valve previously applied by our company. The first solenoid valve includes a valve seat, a coil located within the valve seat, and a first valve stem located in the middle of the coil. A first valve plug is provided at the end of the first valve stem. A spring is sleeved on the first valve stem and the spring presses against the valve plug to keep the solenoid valve in a normally closed state. The slave valve is arranged within the valve seat and includes a fourth iron core, and a fourth valve plug is provided on the fourth iron core.

[0007] Further, as one of the preferred solutions of a pneumatic gas premixing valve, the servo valve can be an electromagnetic servo valve, and the electromagnetic servo valve jointly regulates the opening and closing and the opening degree through electric control and the pressure of the second diaphragm chamber.

[0008] Further, as one of the preferred solutions of a pneumatic gas premixing valve, a signal chamber is provided on the other side of the second diaphragm of the servo valve. An interface for connecting with the air inlet pipeline is provided on the signal chamber. The servo valve can jointly regulate the opening degree according to the pressures in the first diaphragm chamber and the air inlet pipeline. A spring is provided at the rear end of the second valve plug, and the other end of the spring presses against the plug. The pre-pressure of the spring can be adjusted by rotating and adjusting the position of the plug.

[0009] Further, as one of the preferred solutions of a pneumatic gas premixing valve, a flow regulator is provided at the air outlet of the air outlet chamber. The flow regulator includes a valve disc provided at the air outlet. A rotatable screw rod is provided on the valve disc. The screw rod is arranged within an adjusting screw hole, and a sealing ring is provided between the screw rod and the adjusting screw hole.

[0010] Further, as one of the preferred solutions of a pneumatic gas premixing valve, an air inlet pressure measuring port provided on the regulating valve and an air outlet pressure measuring port located in the air outlet chamber are further included.

[0011] A gas device includes a pneumatic gas premixing valve, and further includes an air pipeline. One end of the air pipeline is provided with a blowing device, an air throttle is provided in the middle of the air pipeline, the gas outlet is connected to and provided with a gas injection mechanism, and a combustion chamber is provided at the end of the air pipeline outside the air throttle.

[0012] Further preferably, the air pipeline and the inside of the air throttle are connected to the signal chamber through a signal pipe. When the air pipeline passes through the air throttle, the area decreases and the flow rate increases. At this time, the gas on the gas pipeline will be carried into and out of the combustion chamber.

[0013] The beneficial effects of the present invention are as follows: Through the branch linkage of the first diaphragm chamber and the second diaphragm chamber, combined with the cooperation of the servo valve and the regulating valve, the opening degree can be dynamically regulated according to the gas inlet pressure and the air pipeline pressure. The air pressure signal is introduced into the second diaphragm chamber to realize real-time compensation of the gas-air pressure difference, ensure the stability of the air-fuel ratio, and avoid problems such as incomplete combustion or flashback.

[0014] The mechanical linkage design of the first solenoid valve and the driven valve realizes the rapid switching of the control chamber pressure through the synchronous action of the fourth iron core. The normally closed spring structure of the solenoid valve automatically cuts off the gas path when the power is off, and the adjustable spring pressure design of the servo valve forms multiple safety redundancies, which significantly improves the safety of the system.

[0015] The valve plug is self-driven by the pressure of the diaphragm chamber (the first diaphragm chamber and the second diaphragm chamber), and the valve is opened and closed by the potential energy of the gas pressure, reducing the dependence on external power; the servo valve electronic control and air pressure combined regulation can adapt to complex working conditions, while maintaining the regulation accuracy, reducing the energy consumption of electromagnetic components and extending the service life.

[0016] The three-chamber layered design (first chamber - control chamber - outlet chamber) combined with the support limit valve stem structure reduces turbulent interference; and all adjustment and pressure measuring ports are ensured to be on the same side, which is convenient for users to adjust. The screw seal structure of the flow regulator allows linear adjustment of the air output, and closed-loop monitoring is achieved through the air inlet / outlet pressure measuring ports, which is convenient for accurate matching of combustion load requirements.

[0017] The gas device uses the air pressure signal generated by the Venturi effect in fluid mechanics to drive the opening adjustment of the gas valve to achieve automatic matching and adjustment of the gas volume. The gas valve in this project consists of two double-link double-circuit solenoid valves and a servo valve.

[0018] The gas volume is adjusted through the filter, solenoid valve and servo valve from the air inlet. The servo valve is driven by the air pressure signal, and a linear relationship is established between the air pressure and the gas pressure. This allows the air and gas to be kept in a reasonable and fixed mixing ratio throughout the combustion process, ensuring full combustion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a cross-sectional view of an embodiment of the present invention.

[0020] Figure 2 This is a cross-sectional view of embodiment 2 of the present invention.

[0021] Figure 3 It is a schematic diagram of the structure of the gas device of the present invention.

[0022] Wherein: 1. Valve body; 11. Gas inlet; 12. Gas outlet; 21. First cavity; 22. Control cavity; 23. Outlet cavity; 31. First solenoid valve; 32. Regulating valve; 33. First branch; 321. First diaphragm; 322. First valve stem; 323. First valve plug; 324. First diaphragm cavity; 310. Slave valve; 34. Servo valve; 341. Second diaphragm; 342. Second valve stem; 343. Second valve plug; 344. Second diaphragm cavity; 35. Second branch; 2. Cover plate; 311. Valve seat; 312. Coil; 315. Fourth iron core; 316. Fourth valve plug; 4. Signal cavity; 41. Interface; 42. Plug; 44. Flow regulator; 45. Valve plate; 46. Screw; 51. Inlet pressure measuring port; 52. Outlet pressure measuring port; 53. Outlet plug; 54. Bracket; 55. Flange; 6. Solenoid valve; 7. Air pipeline; 71. Blowing device; 8. Air restrictor; 9. Combustion chamber; 10. Signal pipe. Detailed implementation mode

[0023] The present invention will be further described below with reference to specific drawings.

[0024] It should be noted that the following first, second, etc. are only used to distinguish one component from another, and do not have specific meanings. Among them, up and down are only defined for convenience of description in the drawings, rather than the absolute up and down of the product.

[0025] Embodiment 1: As Figure 1As shown: A pneumatic gas premixing valve, including a valve body 1, the valve body 1 is provided with a gas inlet 11 and a gas outlet 12. Inside the gas inlet 11, there are successively a first cavity 21, a control cavity 22, and an outlet cavity 23. The first cavity 21 and the control cavity 22 are controlled to open and close by a first solenoid valve 631. A regulating valve 32 is provided on the control cavity 22 and the outlet cavity 23. A first branch 33 is provided between the control cavity 22 and the regulating valve 32. The regulating valve 32 includes a first diaphragm 321, a first valve stem 322 and a first valve plug 323 are arranged on the first diaphragm 321. There is a first diaphragm 321 cavity outside the first diaphragm 321, and the first branch 33 communicates with the first diaphragm 321 cavity. A slave valve 310 linked with the first solenoid valve 631 is provided on the first branch 33. The regulating valve 32 controls the opening and closing and the opening degree of the valve body 1 through the pressure in the first diaphragm 321 cavity. A servo valve 34 is provided on the outlet cavity 23. The servo valve 34 includes a second diaphragm 341, a second valve stem and a second valve plug are arranged on the second diaphragm 341. A second diaphragm 341 cavity is formed between the second diaphragm 341 and the valve body 1. A second branch 35 is provided between the first diaphragm 321 cavity and the second diaphragm 341 cavity. The second branch 35 and the outlet cavity 23 are controlled to open and close and the opening degree by the second valve plug. A cover plate 2 is hermetically covered on the valve body 1, and the first diaphragm 321 cavity is formed by the cover plate 2 and the first diaphragm 321. After the gas at the inlet enters, it fills the first cavity 21. When the first solenoid valve 631 is opened, the gas enters the control cavity 22, and the slave valve 310 is synchronously opened with the first solenoid valve 631. The gas pressure filling the control cavity 22 enters the first diaphragm 321 cavity through the first branch 33. The diaphragm is pushed by the pressure to open the regulating valve 32. The first diaphragm 321 cavity and the second diaphragm 341 cavity are communicated through the second branch 35. When the pressure in the first diaphragm 321 cavity is too high, it will cause the opening degree to be too large. At this time, the pressure in the second diaphragm 341 cavity increases synchronously, so that it opens, and then the second valve plug is pushed open to connect the inside with the outlet cavity 23.

[0026] The first solenoid valve 631 includes a valve seat 311, a coil 312 located inside the valve seat 311, and a first valve stem 313 located in the middle of the coil 312. A first valve plug 314 is provided at the end of the first valve stem 313. A spring is sleeved on the first valve stem 313 and the spring presses against the valve plug to keep the solenoid valve 6 (confused with the servo solenoid valve 6, need to distinguish) in a normally closed state. The slave valve 310 is arranged inside the valve seat 311. The slave valve 310 includes a fourth iron core 315, and a fourth valve plug 316 is provided on the fourth iron core 315.

[0027] On the top of the servo solenoid valve 6, there is a limit pressure regulating device applied for by our company earlier. On the upper part of the solenoid valve 6, there is a maximum pressure limit nut, and a small pressure pre-adjustment knob is adjusted on the limit nut. The end of the internal moving iron core passes through the limit nut, and a circlip is provided at the end. The circlip is limited by the limit nut to further limit the maximum downward displacement of the internal moving iron core. A small pre-adjustment spring is provided between the circlip and the small pre-adjustment nut, which can pre-adjust the minimum air outlet flow or pressure during factory production.

[0028] It can also be jointly adjusted and controlled by a program in cooperation with a circuit controller. Through the feedback of the combustion working condition, the magnitude of the current input to the solenoid valve 6 can be adjusted to achieve stepless adjustment of the air outlet flow or pressure.

[0029] In this embodiment, the servo valve 34 is the solenoid valve 6. The servo valve 34 jointly regulates the opening and closing and the opening degree through electric control and the pressure in the second diaphragm 341 cavity. The solenoid valve 6 can jointly regulate the opening and closing and the opening degree through the pressure linkage between the air inlet pressure measuring port 51 and the air outlet pressure measuring port 52.

[0030] Example 2: According to Figure 2As shown: A pneumatic gas premixing valve, including a valve body 1. The valve body 1 is provided with a gas inlet 11 and a gas outlet 12. Inside the gas inlet 11, there are successively a first cavity 21, a control cavity 22, and an outlet cavity 23. Between the first cavity 21 and the control cavity 22, the opening and closing are controlled by a first electromagnetic valve 631. A regulating valve 32 is provided on the control cavity 22 and the outlet cavity 23. There is a first branch 33 communicating between the control cavity 22 and the regulating valve 32. The regulating valve 32 includes a first diaphragm 321. A first valve stem 322 and a first valve plug 323 are arranged on the first diaphragm 321. There is a first diaphragm 321 cavity outside the first diaphragm 321. The first branch 33 communicates with the first diaphragm 321 cavity. A slave valve 310 linked with the first electromagnetic valve 631 is provided on the first branch 33. The regulating valve 32 controls the opening and closing and the opening degree of the valve body 1 through the pressure in the first diaphragm 321 cavity. A servo valve 34 is provided on the outlet cavity 23. The servo valve 34 includes a second diaphragm 341. A second valve stem and a second valve plug are arranged on the second diaphragm 341. A second diaphragm 341 cavity is formed between the second diaphragm 341 and the valve body 1. A second branch 35 is provided between the first diaphragm 321 cavity and the second diaphragm 341 cavity. The second branch 35 and the outlet cavity 23 control the opening and closing and the opening degree through the second valve plug. A cover plate 2 is hermetically covered on the valve body 1. The first diaphragm 321 cavity is formed by the cover plate 2 and the first diaphragm 321. After the gas enters from the gas inlet, it fills the first cavity 21. When the first electromagnetic valve 631 is opened, the gas enters the control cavity 22, and the slave valve 310 is synchronously opened with the first electromagnetic valve 631. The gas pressure filling the control cavity 22 enters the first diaphragm 321 cavity through the first branch 33. The diaphragm is pushed by the pressure to open the regulating valve 32. The first diaphragm 321 cavity and the second diaphragm 341 cavity are communicated through the second branch 35. When the pressure in the first diaphragm 321 cavity is too high, it will cause the opening degree to be too large. At this time, the pressure in the second diaphragm 341 cavity increases synchronously, causing it to open, and then pushing open the second valve plug to connect the inside with the outlet cavity 23.

[0031] The first electromagnetic valve 631 includes a valve seat 311, a coil 312 located inside the valve seat 311, and a first valve stem 313 located in the middle of the coil 312. A first valve plug 314 is provided at the end of the first valve stem 313. A spring is sleeved on the first valve stem 313, and the spring presses against the valve plug to keep the first valve plug 314 in a normally closed state. The slave valve 310 is arranged inside the valve seat 311. The slave valve 310 includes a fourth iron core 315, and a fourth valve plug 316 is provided on the fourth iron core 315.

[0032] In this embodiment, on the other side of the second diaphragm 341 of the servo valve 34, there is a signal chamber 4. The signal chamber 4 is provided with an interface 41 for connecting to the air inlet pipeline. The servo valve 34 can jointly adjust the opening degree according to the pressures in the first diaphragm 321 chamber and the air inlet pipeline. A spring is provided at the rear end of the second valve plug, and the other end of the spring abuts against the plug 42. By rotating and adjusting the position of the plug 42, the spring pressure can be adjusted. The signal chamber 4 is linked and adjusted according to the pressure of the gas air pipeline 7, the spring, and the pressure in the second diaphragm 341 chamber, so that the gas rate is linked to the air inlet pressure. The greater the air inlet pressure, the greater the tolerance of the second diaphragm 341 chamber for coordinated adjustment, effectively improving the gas combustion efficiency. When the air pressure suddenly decreases, it can quickly respond to open the pressure in the second diaphragm 341 chamber, reduce gas emissions, and avoid the generation of harmful gases due to incomplete combustion.

[0033] In this embodiment, to avoid too low pressure in the air outlet chamber 23, a flow regulator 44 is provided at the air outlet of the air outlet chamber 23. The flow regulator 44 includes a valve plate 45 covering the air outlet. A screw rod 46 is rotatably provided on the valve plate 45. The screw rod 46 is screwed in the adjustment screw hole, and a sealing ring is provided between the screw rod 46 and the adjustment screw hole.

[0034] A gas device, such as Figure 3 shown: It includes a pneumatic gas premixing valve, and also includes an air pipeline. One end of the air pipeline is provided with a blowing device, an air throttle is provided in the middle of the air pipeline, the gas outlet is connected to and provided with a gas injection mechanism, and a combustion chamber is provided at the end of the air pipeline outside the air throttle.

[0035] In this embodiment, when the valve body adopts the solution of Embodiment 2, the air pipeline and the inside of the air throttle are connected to the signal chamber through a signal pipe. The inner diameter of the air pipeline suddenly decreases through the air throttle, and the flow rate increases. At this time, the gas on the gas pipeline will be brought into and out of the combustion chamber.

[0036] The above are only specific implementation manners of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A pneumatic gas premixing valve, comprising a valve body (1), the valve body (1) being provided with a gas inlet (11) and a gas outlet (12), the inner side of the gas inlet (11) being provided with a first cavity (21), a control cavity (22), and an outlet cavity (23) in sequence, the first cavity (21) and the control cavity (22) being opened and closed by a first solenoid valve (6) (31), the control cavity (22) and the outlet cavity (23) being provided with a regulating valve (32); a first branch valve (6) (31) being provided between the control cavity (22) and the regulating valve (32) The regulating valve (32) comprises a first diaphragm (321), a first valve stem (322) and a first valve plug (323) are arranged on the first diaphragm (321), a first diaphragm (321) cavity is provided on the outer side of the first diaphragm (321), and the first branch (33) is connected to the first diaphragm (321) cavity; the first branch (33) is provided with a driven valve (310) linked to the first solenoid valve (6) (31), and the regulating valve (32) controls the opening and closing and the opening degree of the valve body (1) through the pressure of the first diaphragm (321) cavity; The air outlet cavity (23) is provided with a servo valve (34), the servo valve (34) comprising a second diaphragm (341), the second diaphragm (341) being provided with a second valve stem and a second valve plug, the second diaphragm (341) and the valve body (1) forming a second diaphragm (341) cavity, a second branch (35) being provided between the first diaphragm (321) cavity and the second diaphragm (341) cavity, the second branch (35) and the air outlet cavity (23) being controlled in opening and closing and in terms of opening degree through the second valve plug.

2. The pneumatic gas premixing valve according to claim 1 is characterized in that: The sealing cover on the valve body (1) is provided with a cover plate (2), and the cover plate (2) and the first diaphragm (321) form the first diaphragm (321) cavity.

3. The pneumatic gas premixing valve according to claim 2 is characterized in that: The first solenoid valve (6) (31) comprises a valve seat (311), a coil (312) located in the valve seat (311), and a first valve stem (313) located in the middle of the coil (312); a first valve plug (314) is provided at the end of the first valve stem (313); a spring is sleeved on the first valve stem (313) and the spring presses on the valve plug so that the solenoid valve (6) is in a normally closed state; the driven valve (310) is arranged in the valve seat (311); the driven valve (310) comprises a fourth iron core (315); and a fourth valve plug (316) is provided on the fourth iron core (315).

4. The pneumatic gas premixing valve according to claim 3 is characterized in that: A signal cavity (4) is provided on the other side of the second diaphragm (341) of the servo valve (34), and an interface (41) for communicating with an air intake pipeline is provided on the signal cavity (4). The servo valve (34) can adjust the opening degree in combination according to the pressure in the first diaphragm (321) cavity and the air intake pipe. A spring is provided on the top of the rear end of the second valve plug, and the other end of the spring is provided on the top of a screw plug (42). The spring pressure can be adjusted by rotating the screw plug to adjust the position.

5. The pneumatic gas premixing valve according to claim 4 is characterized in that: The air outlet of the air outlet cavity (23) is provided with a flow regulator (44), the flow regulator (44) comprising a valve plate (45) covering the air outlet, a screw rod (46) rotatably provided on the valve plate (45), the screw rod (46) being arranged in an adjusting screw hole, and a sealing ring being provided between the screw rod (46) and the adjusting screw hole.

6. The pneumatic gas premixing valve according to claim 1, characterized in that: It also includes an air inlet pressure measuring port (51) in communication with the control chamber (22) and an air outlet pressure measuring port (52) in communication with the air outlet chamber (23).

7. The pneumatic gas premixing valve according to claim 1, characterized in that: An opening is provided between the control chamber (22) and the air outlet chamber (23), the valve stem of the regulating valve (32) is inserted into the opening, an air outlet plug (53) is provided at the upper end of the valve stem located in the regulating chamber, and a bracket (54) fixed on the opening for limiting the position and inserting the valve stem is also provided, a flange (55) is protruding from the lower end of the valve stem, and a spring is also provided, the spring top being arranged between the bracket (54) and the flange (55).

8. The pneumatic gas premixing valve according to claim 3 is characterized in that: The servo valve (34) may also be a solenoid valve (6), which adjusts the opening of the second valve plug steplessly by changing the input current in conjunction with the pressure in the second diaphragm (341) cavity, thereby achieving the purpose of steplessly adjusting the outlet pressure or flow.

9. A gas device, comprising the pneumatic gas premixing valve according to any one of claims 1 to 8, characterized in that: It also comprises an air pipeline (7), one end of the air pipeline (7) is provided with an air blowing device (71), the middle of the air pipeline (7) is provided with an air throttle (8), the gas outlet (12) is connected to the outside of the air throttle (8), and the end of the air pipeline (7) is provided with a combustion chamber (9).

10. The gas device according to claim 9, characterized in that: The air pipeline (7) and the inner side of the air throttle (8) are connected to the signal chamber (4) via a signal tube (10).

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