A test device and method for detecting leakage of natural gas equipment in an engine

Abstract

The present invention relates to a leakage detection test device and method for engine natural gas equipment, which is used to detect the air tightness between the inner cavity and the compartment of a natural gas double-wall pipe, and includes a base, and the surface of the base is provided with a slide and a slide seat for placing the double-wall pipe and a fixing component for fixing the double-wall pipe, and the fixing component includes two front plates and a rear plate that are butted against each other. The detection test is performed by setting the detection component to cut off the front end of the first solenoid valve from the air compressor after the inflation is completed, and connect it with the external atmospheric environment, so as to prevent the pressure storage pipe of the air compressor from continuously supplying pressure to the inner cavity through the first solenoid valve with internal leakage, which affects the reading and is difficult to detect. If the first solenoid valve has internal leakage, the high-pressure gas in the inner cavity leaks out, and the phenomenon manifested is that the reading of the air pressure transmitter becomes smaller, which is convenient for timely detection of abnormalities and eliminates the interference caused by the internal leakage of the solenoid valve during the test.

Description

Technical Field

[0001] The invention belongs to the technical field of engine natural gas equipment detection, and in particular relates to a leakage detection test device and method for engine natural gas equipment. Background Art

[0002] At present, with the increasing requirements of international ship emission standards and the need to improve the power of marine diesel engines, mixed fuel marine engines are increasingly used, among which dual-fuel engines using diesel and natural gas as fuel are a major type. However, the use of natural gas requires environmental safety, so the airtightness test of equipment that injects natural gas is particularly important. Among them, the natural gas transmission and injection of dual-fuel diesel engines are mainly carried out in their double-walled pipes and pipe sockets (such as Figure 6-7 As shown in the figure, the compartment is to prevent the natural gas from directly entering the outside air when it leaks, and the inner cavity is the flow channel of the natural gas. Therefore, the detection of the air tightness of the inner cavity is an important process of the product.

[0003] The existing detection method is to pass high-pressure gas into the inner cavity through an air compressor, and then determine whether there is a leak by observing whether the air pressure values ​​of the inner cavity and the partition cavity change. The disadvantage is that the solenoid valve at the air inlet is constantly opened and closed during the test, and the service life of the gas solenoid valve is related to the number of opening and closing times. Therefore, it is difficult to detect when the solenoid valve leaks. The pressure storage tank of the air compressor continuously supplies pressure, which has a great influence on the judgment of the air pressure value of the inner cavity. Therefore, the interference caused by the internal leakage of the solenoid valve needs to be eliminated during the detection. Summary of the invention

[0004] The purpose of the present invention is to provide a leakage detection test device and method for engine natural gas equipment with simple structure and reasonable design in order to solve the above problems.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] A leakage detection test device for engine natural gas equipment, used for detecting the air tightness between the inner cavity and the compartment of a natural gas double-wall pipe, comprising a base, the surface of the base is provided with a slide and a slide seat for placing the double-wall pipe and a fixing assembly for fixing the double-wall pipe, the fixing assembly comprises two mutually butted front plates and a rear plate, respectively used for closing the flange surfaces on both sides of the double-wall pipe, the surface of the front plate is provided with a pressure gauge connected to the compartment, and an air intake pipe connected to the inner cavity is also provided, the surface of the base is provided with an air compressor for supplying high-pressure air to the air intake pipe, the interior of the air intake pipe is provided with a first solenoid valve and a pressure transmitter electrically connected to the first solenoid valve, and a detection assembly is provided at the connection between the air intake pipe and the air compressor, used for preventing internal leakage of the first solenoid valve;

[0007] The detection assembly comprises a sealing slide bar arranged inside the shell, and the sealing slide bar is used to release the high pressure at the front end of the first solenoid valve after the air pressure in the compartment reaches a set value.

[0008] As a further optimization scheme of the present invention, the front plate is fixed to the end of the L-shaped frame on the base surface, and the front plate and the rear plate are connected to each other through a piston column and a piston cylinder, and a motor and a threaded rod are provided at the connection point for fixing each other.

[0009] As a further optimization scheme of the present invention, a sealing groove for accommodating a sealing slide rod is provided inside the shell, an air inlet connected to the output pipe of the air compressor is provided at one end of the shell, and a balancing port connected to the rear end of the first solenoid valve is provided at the other end, a spring is provided at the end of the sealing slide rod close to the balancing port, an annular groove is provided in the middle section of the sealing groove, and the annular groove is connected to the front end of the first solenoid valve through an air outlet.

[0010] As a further optimization solution of the present invention, a side groove for facilitating air guiding is provided on the side surface of one end of the annular groove close to the air inlet.

[0011] As a further optimization scheme of the present invention, a bottom groove is opened at the bottom end of the annular groove, an exhaust port is arranged on the surface of the bottom groove, an arc plate for closing the exhaust port is arranged between the side walls of the bottom groove through a hinged rod, the arc plate is slidably arranged with the end of the hinged rod, and a fixing part for pushing the hinged rod to rotate is arranged on the surface of the sealing sliding rod.

[0012] As a further optimization solution of the present invention, a sealing gasket is provided between the arc plate and the exhaust port.

[0013] As a further optimization solution of the present invention, a normally open second solenoid valve is also provided inside the air intake pipe for checking whether the first solenoid valve is leaking when the air pressure reading is abnormal.

[0014] Based on the above engine natural gas equipment leakage detection test device, the present invention also proposes an engine natural gas equipment leakage detection test method, comprising the following steps:

[0015] S1: Fixing: Place the double-walled pipe on the slide, then push the slide to make the piston rod enter the inner cavity of the double-walled pipe, insert the rear plate and the piston cylinder from the other end of the double-walled pipe, start the motor to make the front and rear plates clamp the double-walled pipe and close the flange surfaces on both sides;

[0016] S2: Test: Start the air compressor, inject high-pressure gas up to 0.6Mpa into the inner cavity, and maintain it for 10 minutes, and observe whether the before and after readings of the pressure gauge and air pressure transmitter change;

[0017] S3: Judgment: If the readings of the pressure gauge and the air pressure transmitter remain unchanged, it means that the air tightness test is good; if the readings of the pressure gauge remain unchanged and the air pressure transmitter decreases, it is necessary to check whether the first solenoid valve has internal leakage; if the air pressure of the pressure gauge increases and the air pressure transmitter decreases, it is judged that the air tightness of the inner cavity is not good.

[0018] The beneficial effects of the present invention are:

[0019] The present invention sets a detection component to cut off the front end of the first solenoid valve from the air compressor after inflation is completed, and connect it to the external atmospheric environment, so as to prevent the pressure storage pipe of the air compressor from continuously supplying pressure to the inner cavity through the first solenoid valve with internal leakage, which affects the reading and is difficult to detect. If there is an internal leakage in the first solenoid valve, the high-pressure gas in the inner cavity will leak out, and the phenomenon manifested is that the reading of the air pressure transmitter becomes smaller, which facilitates the timely detection of abnormalities and eliminates the interference caused by the internal leakage of the solenoid valve during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 The present invention Figure 1 A magnified view of the structure of part A;

[0022] Figure 3 It is a schematic diagram of the internal structure of the detection component of the present invention;

[0023] Figure 4 The present invention Figure 3 A magnified view of the structure of part B;

[0024] Figure 5 The present invention Figure 3 Middle CC section view;

[0025] Figure 6 It is a side view of a double-wall nozzle;

[0026] Figure 7 It is a side view and cross-sectional view of a double-wall nozzle;

[0027] In the figure: 11, base; 12, L-shaped frame; 13, slide; 14, slide seat; 15, air compressor; 21, front plate; 22, pressure gauge; 23, air pressure transmitter; 24, air inlet pipe; 25, piston column; 26, piston cylinder; 27, threaded rod; 28, back plate; 29, motor; 31, first solenoid valve; 32, second solenoid valve; 41, shell; 42, sealing groove; 43, air inlet; 44, balance port; 45, air outlet; 46, annular groove; 47, side groove; 51, sealing slide rod; 52, spring; 53, hinged rod; 54, arc plate; 55, bottom groove; 56, exhaust port; 6, double-walled pipe; 61, inner cavity; 62, compartment; 63, first sealing ring; 64, second sealing ring. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0029] Example 1

[0030] like Figure 1-5 As shown, a leakage detection test device for engine natural gas equipment is used to detect the air tightness between the inner cavity 61 and the compartment 62 of the natural gas double-wall pipe 6, including a base 11, the surface of the base 11 is provided with a slide 13 and a slide seat 14 for placing the double-wall pipe 6 and a fixing component for fixing the double-wall pipe 6, the fixing component includes two front plates 21 and a rear plate 28 butted against each other, respectively used to close the flange surfaces on both sides of the double-wall pipe 6, the front plate 21 is fixed to the end of the L-shaped frame 12 on the surface of the base 11, the front plate 21 and the rear plate 28 are butted against the piston cylinder 26 through the piston column 25, and a motor 29 and a threaded rod 27 are provided at the butt joint for mutual fixation, wherein the flange surfaces on both sides of the double-wall pipe 6 are provided with a first sealing ring 63 and a second sealing ring 64, the front plate 21 and the rear plate 28 are respectively used to seal the inner cavity 61 and the compartment 62 after being squeezed, and an automatic fixing method is provided, so that the fixing process before detection is simple and fast, and the detection efficiency is improved.

[0031] The surface of the front plate 21 is provided with a pressure gauge 22 connected to the compartment 62, and is also provided with an air intake pipe 24 connected to the inner cavity 61. The surface of the base 11 is provided with an air compressor 15 for supplying high-pressure air to the air intake pipe 24. The interior of the air intake pipe 24 is provided with a first solenoid valve 31 and an air pressure transmitter 23 electrically connected to the first solenoid valve 31. The model of the air pressure transmitter 23 is: MIK-P300. When the air pressure transmitter 23 detects that the air pressure inside the air intake pipe 24 reaches the set value, it controls the first solenoid valve 31 to close.

[0032] A detection assembly is provided at the connection between the intake pipe 24 and the air compressor 15, which is used to prevent the first solenoid valve 31 from leaking internally. The detection assembly includes a sealing slide rod 51 provided inside the housing 41, and a sealing groove 42 for accommodating the sealing slide rod 51 is provided inside the housing 41. An intake port 43 connected to the output pipe of the air compressor 15 is provided at one end of the housing 41, and a balance port 44 connected to the rear end of the first solenoid valve 31 is provided at the other end. A spring 52 is provided at one end of the sealing slide rod 51 close to the balance port 44, and an annular groove 46 is provided in the middle section of the sealing groove 42. 46 is connected with the front end of the first solenoid valve 31 through the air outlet 45, and a side groove 47 for air conduction is arranged on the side surface of one end of the annular groove 46 close to the air inlet 43, and a bottom groove 55 is provided at the bottom end of the annular groove 46, and an exhaust port 56 is arranged on the surface of the bottom groove 55, and an arc plate 54 for closing the exhaust port 56 is arranged between the side walls of the bottom groove 55 through a hinge rod 53, a sealing gasket is arranged between the arc plate 54 and the exhaust port 56, the arc plate 54 is slidingly arranged with the end of the hinge rod 53, and a fixing part for pushing the hinge rod 53 to rotate is arranged on the surface of the sealing slide rod 51.

[0033] The function of the detection component is: the air pressure transmitter 23 detects that the air pressure reaches the set value, that is, the air pressure in the inner cavity 61 reaches the output pressure of the air compressor 15. At this time, the first solenoid valve 31 is closed and enters the pressure maintaining process. The detection component cuts off the front end of the first solenoid valve 31 from the air compressor 15 and connects it to the external atmospheric environment to prevent the pressure storage pipe of the air compressor 15 from continuously supplying pressure to the inner cavity 61 through the leaking first solenoid valve 31, which affects the reading and is difficult to detect. If there is an internal leakage in the first solenoid valve 31, the high-pressure gas in the inner cavity 61 leaks out, and the phenomenon manifested is that the reading of the air pressure transmitter 23 becomes smaller, which is convenient for timely detection of abnormalities.

[0034] The working principle of the detection component is: when the air compressor 15 is working, the air pressure at the air inlet 43 pushes the sealing slide rod 51 to slide, so that the gas enters the annular groove 46 through the side groove 47, and enters the inner cavity 61 through the air outlet 45 and the first solenoid valve 31. When the sealing slide rod 51 slides, it pushes the hinge rod 53 to rotate, so that the arc plate 54 covers the exhaust port 56. The sliding arc plate 54 squeezes the exhaust port 56 under high pressure to achieve a sealing effect, ensuring that the high-pressure gas enters the inner cavity 61. When the pressure of the intake pipe 24 is consistent with the output pressure of the air compressor 15, the air pressure transmitter 23 controls the first solenoid valve 31 to close, and the air pressure of the air inlet 43 and the balance port 44 are consistent and balanced. Under the action of the spring 52, the sealing slide rod 51 closes the air inlet 43, and at the same time drives the arc plate 54 to rotate to leak out of the exhaust port 56, so that the annular groove 46 is connected with the outside world, thereby releasing the pressure at the front end of the first solenoid valve 31.

[0035] A normally open second solenoid valve 32 is also provided inside the air intake pipe 24, which is used to check whether the first solenoid valve 31 is leaking when the air pressure reading is abnormal. The second solenoid valve 32 is in a normally open state, has lower wear and tear, and has a lower probability of internal leakage than the first solenoid valve 31. When the reading of the air pressure transmitter 23 decreases, the second solenoid valve 32 is enabled for re-detection to check whether the first solenoid valve 31 is leaking internally.

[0036] In order to implement the device, the present application also proposes a method for detecting leakage of an engine natural gas device, comprising the following steps:

[0037] S1: Fixing: Place the double-walled pipe 6 on the slide 14, then push the slide 14 to make the piston rod 25 enter the inner cavity 61 of the double-walled pipe 6, insert the rear plate 28 and the piston cylinder 26 from the other end of the double-walled pipe 6, and start the motor 29 to make the front and rear plates clamp the double-walled pipe 6 and close the flange surfaces on both sides;

[0038] S2: Test: Start the air compressor 15, inject high-pressure gas up to 0.6 MPa into the inner cavity 61, and keep it for 10 minutes, and observe whether the readings of the pressure gauge 22 and the air pressure transmitter 23 change;

[0039] S3: Judgment: If the readings of the pressure gauge 22 and the air pressure transmitter 23 remain unchanged, it means that the air tightness test is good; if the reading of the pressure gauge 22 remains unchanged and the air pressure transmitter 23 decreases, it is necessary to check whether the first solenoid valve 31 has an internal leak; if the air pressure of the pressure gauge 22 increases and the air pressure transmitter 23 decreases; it is judged that the air tightness of the inner cavity 61 is not good.

[0040] It should be emphasized that the air tightness of the inner cavity 61 needs to be judged by the readings of the pressure gauge 22 and the air pressure transmitter 23. If only one of the readings is used for judgment, there is a possibility of misjudgment. If only the reading of the pressure gauge 22 is used for judgment, if the first sealing ring 63 is leaking, the compartment 62 is actually connected to the external atmospheric environment, and the reading of the pressure gauge 22 is normal.

[0041] The front end and rear end of the solenoid valve described above refer to the division according to the gas flow direction, with the gas inflow end being the front end and the gas outflow end being the rear end.

[0042] The above-mentioned embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A leakage detection test device for engine natural gas equipment, used for detecting the air tightness between the inner cavity (61) and the compartment cavity (62) of a natural gas double-wall pipe (6), comprising a base (11), a surface of the base (11) being provided with a slide frame (13) and a slide seat (14) for placing the double-wall pipe (6) and a fixing assembly for fixing the double-wall pipe (6), characterized in that: The fixing assembly comprises two front plates (21) and a rear plate (28) butted against each other, respectively used to seal flange surfaces on both sides of the double-walled pipe (6); a pressure gauge (22) communicating with the compartment (62) is disposed on the surface of the front plate (21); an air intake pipe (24) communicating with the inner cavity (61) is also disposed; an air compressor (15) for supplying high-pressure air to the air intake pipe (24) is disposed on the surface of the base (11); a first solenoid valve (31) and a pressure transmitter (23) electrically connected to the first solenoid valve (31) are disposed inside the air intake pipe (24); a detection assembly is disposed at the connection between the air intake pipe (24) and the air compressor (15) for preventing internal leakage of the first solenoid valve (31); The detection component comprises a sealing slide bar (51) arranged inside the shell (41), and the sealing slide bar (51) is used to release the high pressure at the front end of the first solenoid valve (31) after the air pressure in the compartment (62) reaches a set value; a sealing groove (42) for accommodating the sealing slide bar (51) is provided inside the shell (41), one end of the shell (41) is provided with an air inlet (43) connected to the output pipe of the air compressor (15), and the other end is provided with a balance port (44) connected to the rear end of the first solenoid valve (31), and a spring (52) is provided at one end of the sealing slide bar (51) close to the balance port (44), and an annular groove (46) is provided in the middle section of the sealing groove (42), and the annular groove (46) is connected to the front end of the first solenoid valve (31) through the air outlet (45); A side groove (47) for facilitating air conduction is provided on a side surface of one end of the annular groove (46) close to the air inlet (43); A bottom groove (55) is formed at the bottom end of the annular groove (46), an exhaust port (56) is provided on the surface of the bottom groove (55), an arc plate (54) for closing the exhaust port (56) is provided between the side walls of the bottom groove (55) via a hinge rod (53), the arc plate (54) is slidably arranged with the end of the hinge rod (53), and a fixing member for driving the hinge rod (53) to rotate is provided on the surface of the sealing slide rod (51).

2. The engine natural gas equipment leakage detection test device according to claim 1, characterized in that: The front plate (21) is fixed to the end of the L-shaped frame (12) on the surface of the base (11), and the front plate (21) and the rear plate (28) are butt-jointed via a piston column (25) and a piston cylinder (26), and a motor (29) and a threaded rod (27) are provided at the butt joint for mutual fixing.

3. The engine natural gas equipment leakage detection test device according to claim 1, characterized in that: A sealing gasket is provided between the arc-shaped plate (54) and the exhaust port (56).

4. The engine natural gas equipment leakage detection test device according to claim 1, characterized in that: A normally open second solenoid valve (32) is also provided inside the air intake pipe (24) for checking whether the first solenoid valve (31) is leaking when the air pressure reading is abnormal.

5. A test method for detecting leakage of engine natural gas equipment using the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: Fixing: Place the double-walled pipe (6) on the slide seat (14), then push the slide seat (14) to allow the piston rod (25) to enter the inner cavity (61) of the double-walled pipe (6), insert the rear plate (28) and the piston cylinder (26) as a whole from the other end of the double-walled pipe (6), and start the motor (29) to allow the front and rear plates to clamp the double-walled pipe (6) and close the flange surfaces on both sides; S2: Test: Start the air compressor (15) and inject high-pressure gas up to 0.6 MPa into the inner cavity (61). Maintain the pressure for 10 minutes and observe whether the readings of the pressure gauge (22) and the air pressure transmitter (23) change. S3: Determination: If the readings of the pressure gauge (22) and the air pressure transmitter (23) remain unchanged, it indicates that the air tightness test is good; if the reading of the pressure gauge (22) remains unchanged and the reading of the air pressure transmitter (23) decreases, it is necessary to check whether the first solenoid valve (31) has internal leakage; if the air pressure of the pressure gauge (22) increases and the air pressure transmitter (23) decreases, it is determined that the air tightness of the inner cavity (61) is not good.

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