KR101130388B1 - Leak alarm for high-pressure pipe - Google Patents

Abstract

The present invention relates to a high-pressure system in combustion engines and particularly to leak alarms. The idea is to connect the leak flow space of the high-pressure pipe via a valve to an expansion space and furthermore, to measure the pressure in the leak flow space. The valve provides the operatively necessary limitation of the volume of the flow space for pressure measurement and at the same time it acts as a discharge passage for possible over-pressure and leak fuel. A direct passage out of the engine may act as an expansion space. Another option is to use the channel for continuous leak connected to the fuel recycle system as an expansion space.

Description

Leak Alarm for High Pressure Pipes {LEAK ALARM FOR HIGH-PRESSURE PIPE}

The present invention relates to high pressure pipe systems for combustion engines, and more particularly to leak alarms.

Many combustion engines, especially large combustion engines, include fuel conduits / conduits with high pressure fuel flowing therein. These conduits are commonly referred to as high pressure pipes. For example, it is known to place fuel pipes in other tubular sleeves in order to retain leaks that may occur inside the external piping in a diesel engine. If a leak occurs in the system, the leaked fuel flows out of the engine and flows into the other sleeve. Such a configuration is disclosed, for example, in EP A 0002385 and EP A 0786593.

In order to detect leaks in such devices, various types of plugs have been used, for example, and leaks can be detected by unfastening the plugs. Another commonly used method is the use of detachable hoses, which can also detect leaks by dropping the hoses. However, these known methods are the most rudimentary and have been very slow and inconvenient to find leaks. The hose or plug needed to be loosened alternately until leaks were found several times.

GB A 2060800 discloses an example of a fitting for use in double-walled fuel piping of an engine. By using this device, leaking fuel can be discharged out of the flow space formed by the outer wall. According to the publication, the device can be applied with an injector pump manifold and can connect the outlet of the device to a conventional discharge line. The device according to the specification has a piston member which is moved in the event of a leak so that leaking fuel can be directed through the device to the discharge line while at the same time the pin of the piston member is extended to indicate the leak. Comes out. However, this device is particularly difficult to apply to large engines having a common rail storage injection system with a wide range of fuel piping and many branch pipes. By using the above disclosed configuration, the system becomes very distracting and therefore difficult to use and maintain.

1 shows a more improved fuel transfer system. The figure is a schematic sectional view of a fuel transfer system of a combustion engine, in particular a large combustion engine. Large combustion engine means, for example, that it can be applied as a main engine or auxiliary engine of a ship or a power plant for producing heat and / or electricity. Usually, such large engines are diesel engines. More precisely, Fig. 1 shows an example of a so-called common rail diesel engine configuration.

The combustion engine is, for the sake of clarity, very schematic and may be a known engine. Mainly the cylinder 13 and cylinder head 12 are shown in more detail. In two cylinders, the piston 23 is in its upper position. Fuel is supplied by the fuel delivery pump 1 from the fuel tank 2 via the fuel pipe 3 to each of the high pressure pumps 4, and the fuel pressure is sequentially supplied at an injection pressure level sufficient to supply the injector 11. Is raised. The high pressure pump 4 is connected to a pressure accumulator unit 6, by which the fuel is supplied to the unit. Fuel from the pressure accumulator unit is guided back to the injector 11 by the fuel manifold 7.

Fuel continuously leaks from the nozzle 11 at the cylinder head and is led through the leak pipe 14 to the continuous leak channel 15 connected to the fuel recycling system. In addition, some conventional leaks in the high pressure pump 4 occur and are leaked through the leak pipe 24 into the leak channel 15.

Therefore, in the example of FIG. 1, preferably, the fuel is delivered to the pressure accumulator unit 6 by the high pressure pump 4, and the fuel from the unit is transferred to the engine cylinder 13 by the injector 11. It is configured to include an assembly that is fed back to. Each pressure accumulator unit 6 is connected to at least two injectors 11 and has its own high pressure pump 4. The high pressure pump 4 and the pressure accumulator unit are connected by a fuel transfer pipe 5, the pressure accumulator unit 6 and the injector 11 are connected by a fuel manifold 7, The pressure accumulator unit is connected by a fuel connecting line 8, at least the fuel conveying pipe 5, fuel manifold 7 and fuel connecting line 8 formed of a double wall tube, External flow spaces (for leaking fuel) can be connected to one another. Thus, if a leak occurs somewhere in the system, the leaked fuel flows along the outer flow space 10 and outlet flow channel 20 to the leak tank 21 and the leak indicator 22 connected thereto. Can be. The leak indicator, for example a float or optical sensor indicating the filling of the leak tank, detects the leak. The leaked fuel is sent out of the leak tank of the engine via a throttle pipe 27. The actual high pressure fuel flows inside the inner flow space 110.

In order to find a fuel leak point, the fuel connection line 8 has at least one leaking fuel detection device 18 which is connected to the external flow space of the pipe by a connection line 17. The leak fuel detector 18 is configured to include a leak check member, by means of which the external flow spaces may or may not be connected to each other flow. The detection device is also connected to the outlet flow channel 20 by a connecting line 19.

As shown in FIG. 1, a separation wall 9 or the like is installed in the fuel connection line 8 connected to the pressure accumulator unit 6 of the fuel delivery system, and the external flow space of the delivery system by the wall. (10) and the conveying system itself is divided into separate parts, two of which are shown here, the first of which consists of one of the pressure accumulator units and the injectors connected thereto. Also included is a fuel delivery pump, correspondingly the second of which includes the other pressure accumulator unit and the injectors connected thereto and also the fuel delivery pump, wherein the outer flow space 10 of both separation zones is a leaking fuel. Connected to a detector 18. In this case, the leak fuel detection device 18 arranged in the fuel connection line is not always necessary, but in some fuel delivery systems and engines, the leak detection is a leak fuel detection arranged with the pressure accumulator unit 6. It can be performed mainly by the device.

In FIG. 1, the area 25 enclosed by a dotted line represents a so-called engine hotbox. Thus, the figure shows a device located inside a hotbox.

2 is a cross-sectional view of the hot box. The hot box is an area defined by the cover 28 and its engine body and other components 29, which use heat energy generated by the engine. Since the cover can be opened, the condition of the device can be easily checked. The leak fuel detector 18 with the necessary connection lines 17 and 19 is represented by only the pipe 210 for simplicity. 2 is a simple principle diagram and therefore does not show all possible devices arranged in a hotbox. 3 is a view of the combustion engine 31 from the outside. The hotbox is typically located at the upper edge of the engine, the cover 28 of which can be opened.

4 shows another application of the leak fuel detector. The figure shows a detailed example for detecting leaks in the high pressure pipes 5, 7, 8, i.e. the coupling point of the high pressure pipe (for example in the cylinder head or the pressure accumulator unit). In this embodiment, a pin 41 with a corresponding pin housing 42, a spring-loaded ball 43, or the like is an external flow space in the pressure accumulator unit 6. It is applied with (10). A spring loaded ball 43 or the like is formed on the pin and maintains the normal position of the pin by a groove (not shown) or the like that cooperates with the ball or the like. For example, if a leak occurs in pipe 8 (or other high pressure pipes, the outer flow space of which is connected to pipe 8 shown in FIG. 4 by a separate channel), the pressure is the pressure in the pin housing. It begins to ascend within space 44). By appropriate configuration of the spring loaded ball 43 or the like and grooves cooperating therewith, it is possible to determine the pressure in the pressure space 44, at which pressure the pin moves outwards in the pin housing 42. It begins to move and reaches the state shown in FIG. 4, in which the leaking fuel is discharged through the channel 45 until it reaches the leak indicator 22. Thus, the pin is arranged with the wall of the pressure accumulator unit 6 to act as a member of action, and the position of the pin relative to the pressure accumulator unit 6 is the impact of the leaking fuel pressure. The flow of leaking fuel may be guided in the outer flow space of the leak detection fuel pipe based on the pin position with respect to the pressure accumulator unit. In the configuration according to this embodiment, the leaking fuel does not flow out of the system even in the detection phase, but the leak is indicated by a pin protruding from the body. As observed in Figure 4, the use of such pins results in a relatively complex and expensive device.

Another problem with the known device is that the delay between the start of the leak and its alarm is relatively long. Because the amount of leaking fuel is relatively small compared to the volume of the leak passage, it takes a long time before the alarm (e.g. a leak indicator associated with the leak tank) reacts. Moreover, for some engine types, the leak channel of the high pressure piping is located outside the hot box, and therefore the channel needs to be cleaned after each alarm because the leak fuel is blocking the channel. The throttle channel associated with the leak tank is also often incorrectly adjusted for leaks of the high pressure pipe.

It is an object of the present invention to solve the above-mentioned problems with the prior art. This object is achieved by the invention described in the claims. The technical idea of the present invention relates to the leakage flow space of a high pressure pipe being connected to an expansion space through a valve and to measuring the main pressure in the leakage flow space. The valve, for example a check valve, serves to limit the volume of the flow space for pressure measurement to the range required for operation, and at the same time serves as an outlet for over-pressure and leaking fuel.

Direct passages (eg channel structures or pipes) out of the engine can function as expansion spaces, through which leaking fuel (and simultaneously generated transient pressures) can be released to the surrounding environment. As a practical device, it is preferable to install the leaking fuel collection container in connection with the discharge port. As another useful alternative, a continuous leak channel connected to the fuel recycling system can be used as the expansion space. An advantage of the continuous leak channel is that it is very easy to arrange the leak pipe including the valve between the high pressure pipe and the normal leak channel since it is preinstalled in the engine. At this time, the total volume of the leak pipe and the leak flow space is limited by the valve, so that the pressure sensor is a target volume for measuring the pressure.

Accordingly, the present invention relates to an apparatus in a combustion engine against leakage in a high pressure pipe, the apparatus comprising at least one valve and at least one pressure sensor, wherein the leak pipe is expanded through the valve. The pressure sensor is connected to a normal flow space of the leak pipe and the external flow space.

1 is a view showing an example of a leaking apparatus in a conventional high pressure pipe;

2 is a side view of the device according to FIG. 1;

3 is a view showing an example of a combustion engine seen from the outside;

4 shows an example of a pin of an indicator for leaking fuel;

5 shows an example of an apparatus according to the invention;

FIG. 6 is a side view of the apparatus according to FIG. 5; FIG.

The invention will be described in detail below with reference to the accompanying drawings.

5 shows an example of an apparatus according to the invention. The device is based on the device shown in Figure 1, but has been modified in accordance with the present invention. In this embodiment, the external flow space 10 of the high pressure pipe 8 connected to the pressure accumulator unit 6 is connected to the channel 15 of the engine for continuous leakage via the leak pipe 53. The leak pipe is provided with a valve 51, preferably a check valve, by which the total volume of the external flow space and the volume of the leak pipe attached thereto can be limited. Note that only a portion of the leak pipe volume located between the valve and the high pressure pipe is included in the total limit volume.

The pressure of the total limiting volume is measured by the pressure sensor 52. Preferably, the pressure sensor has an output for sending pressure measurement data to a control center. When a leak occurs in the high pressure pipe, the pressure within the volume limited by the valve rises rapidly, and the pressure sensor responds. Thus, the delay between leaks and alarms is as short as possible.

The fuel leaking into the external flow space, ie the leaking fuel, is discharged into the continuous leak channel 15 through the valve 51 opened by the pressure increase. Thus, the valve not only provides a limited volume (i.e. a conventional flow space formed by the leak pipe and the external flow space), but also provides an outlet for draining the leaked fuel out of the engine. The apparatus has a pressure sensor.

In FIG. 5, the high pressure pipe 8 is divided into two separated volumes by the separating element 9 (separation wall). The pressure in the first volume is measured by a pressure sensor 52 attached to the leak pipe 53, and the second volume is measured by a sensor attached directly to the high pressure pipe 8. The position of the pressure sensor thus depends on the structure of the system connected to the volume being measured. In addition, the leak pipe 53 may be implemented in a manner suitable for the application. For example, it may be a drilled / milled channel in the structure.

The position of the valve 51 also depends on the structure of the system. The leaking pipe can be very short, in which case the position of the valve is determined without choice and the leaking pipe can be long, in which case the position of the valve can be more freely determined. FIG. 6 is a side view of the device according to FIG. 5; FIG. 5 and 6 show that a conventional leak channel is preferably located within the hot box.

The leak pipes / pipes may also be connected to one channel (preferably one) which forms a passage connected directly or possibly directly out of the engine. Thus, it is not necessary to use a continuous leak channel that is connected to the engine's fuel recycling system to send leak fuel out of the engine from the high pressure pipe. In extreme cases, the leak pipe itself may form a channel outside the engine. Choosing an idea of the structure that can be used depends on the rest of the engine structure. Since the continuous leak channel is installed in most engines in advance, it is conceivable to use the channel. On the other hand, it is desirable to have some kind of vessel for collecting the leaked fuel outside the engine in order to avoid environmental pollution on the direct discharge passage for the leaked fuel. Thus, the common idea for most engines is to use existing channels for continuous leakage.

According to the embodiment according to the present invention, since a conventional leak channel located in the hot box is employed, there is no need to clean the channel separately after the alarm. The heat of the hotbox keeps leaking fuel in the channel fluent so that the fuel does not solidify. Thus, after a leak, the leak channel remains in good condition and is ready for the next leak that may be present. Therefore, it is advantageous to arrange such that the operating members, pressure sensors and valves are included in a hot box.

Since the measurement is carried out by pressure sensors / sensors, neither the leak tank 21 nor the throttle channel 27 connected thereto is required.

The pressure in the inner flow space of the high pressure pipe is usually up to about 1600 bar (in a CR engine), so in the case of pipe rupture this pressure is released into the outer flow space 10 and thereby into the leak pipe 53 The pressure is thereby reduced. By the increase in pressure, the valve is opened to release pressure into the outer space, which is referred to herein as an expansion space. As can be concluded from the above-described embodiment, a direct passage outside the engine or a continuous leak channel connected to the engine's fuel recycling system acts as an expansion space. It is also possible to think of other structural ideas for the required expansion space. Before implementing the device according to the invention, consideration should be given to the pressure shock in the leaking fuel discharge channel. If pressure is not taken into account, the engine may break.

If the pressure in the high pressure pipe is released fast enough and in a large volume, the size of the leak pipe and the channel used is not a problem. The pressure sensor may for example be operated to identify up to 0.1 bar and the valve up to 0.2 bar. Therefore, it is possible to operate the pressure sensor more reliably before the pressure and leaking fuel are discharged into the expansion space. It is also possible to use other actuation parameters for the pressure sensor and the valve.

According to the engine structure according to the present invention, cost reduction can be achieved because a separate channel system or actuator is no longer needed. 5 and 1, it can be seen that the leak fuel detection device 18 has the necessary connection lines 17 and 19, the outlet flow channel and the leak tank 21 as required equipment, but according to the present invention. This is unnecessary in the idea. The cost for the pressure sensor and valve is lower than the saved cost.

It is also possible to arrange the cylinders in the engine individually by connecting a combination of a pressure sensor and a valve to the injector pipe of each cylinder, that is, a high pressure pipe for supplying fuel to each cylinder. The pressure sensor and / or valve may also be connected to a high pressure pipe between the high pressure pump and the pressure accumulator unit or to a high pressure pipe between the pressure accumulator unit.

 Thus, the present invention not only provides a less expensive structure, but also allows a shorter delay between leakage and alarm. Moreover, there is no need to clean the leak channel system after a leak, thereby reducing the need for maintenance and improving reliability.

Although the above-described embodiments of the leak fuel detector are independent, it is also practical to select various basic ideas for operating the same engine according to different embodiments. It is also within the scope of the present invention to combine the principles of operation of the various embodiments. The engine may be a standard engine, a common rail engine or another type of engine. The engine may be a combustion engine, but is preferably a diesel engine.

Although the above-described technical configuration is only shown by the embodiment, it is clear that the present invention is not limited by the above-described embodiment, and various other modifications are possible within the scope of the appended claims.

Claims (13)

 A device in a combustion engine for leakage in a high pressure pipe, comprising: a high pressure pipe consisting of a double wall fuel pipe comprising an inner flow space for fuel and an outer flow space for leaking fuel; An apparatus having at least one leak pipe connected to the external flow space and leading to leak fuel, At least one valve and at least one pressure sensor, said valve and pressure sensor being in separate parts, said leak pipe being connected to an expansion space through said valve, said pressure sensor being said It is connected to the common flow space of the leak pipe and the external flow space, and by the generation of leak fuel, the pressure sensor which is increased or increased in the normal flow space is detected by the pressure sensor for alarm. And the valve is opened to discharge the leaked fuel to the expansion space. The method of claim 1, The expansion space is formed by a channel for the continuous leak from the engine, the space being connected to the fuel recycling system of the engine. The method of claim 1, And the expansion space is formed by a passage outside the engine. The method according to claim 1 or 3, Wherein said leak pipe, valve and pressure sensor are located in a hotbox. 3. The method of claim 2, Wherein said leak pipe, valve, pressure sensor and continuous leak channel are located in a hotbox. The method according to claim 2 or 5, The continuous leak channel is connected by a fuel recycle system and a pipe. The method according to any one of claims 1 to 3, and 5, And the pressure sensor has an output for transferring measurement data from the pressure sensor. The method according to any one of claims 1 to 3, and 5, At least one of the pressure sensor and the valve is connected to a high pressure pipe for supplying fuel to the cylinder. The method according to any one of claims 1 to 3, and 5, At least one of the pressure sensor and the valve is connected to a high pressure pipe between the high pressure pump and the pressure accumulator unit. The method according to any one of claims 1 to 3, and 5, At least one of the pressure sensor and the valve is connected to a high pressure pipe between the pressure accumulator unit. The method according to any one of claims 1 to 3, and 5, The valve is characterized in that the check valve. The method according to any one of claims 1 to 3, and 5, The combustion engine is a device, characterized in that the common rail engine. The method according to any one of claims 1 to 3, and 5, The combustion engine is a device characterized in that the diesel engine.

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