CN100430594C - Leak alarm device for high pressure pipeline - Google Patents

Abstract

The invention relates to a high-pressure system used in an internal combustion engine, in particular to a leakage alarm device. The idea is to connect the leakage flow space of the high-pressure line with the expansion space via a valve and to be able to measure the pressure in this leakage flow space. The valve provides the operationally necessary restriction of the volume of the flow space for pressure measurement and at the same time serves as a discharge channel for possible overpressure and leaking fuel. Direct access outside the engine serves as room for expansion. Another option is to use a continuous leak path connected to the fuel recovery system as room for expansion.

Description

Leak alarm device for high pressure pipeline

field of invention

The invention relates to a high-pressure piping system for an internal combustion engine, and in particular the invention relates to a leak warning device.

Background of the invention

Many internal combustion engines, especially larger ones, have fuel lines through which fuel at high pressure can flow. These lines are often called high pressure lines. For example in diesel engines it is common to have fuel lines in another tubular sleeve in order to receive possible leaks of fuel in the outer sleeve. When a leak occurs in the system, the leaking fuel flows out of the diesel engine and into the outer tubular sleeve. For example, European Patent No. A 0002385 and No. A 0786593 disclose the above solutions.

In order to detect leaks in corresponding devices, for example, various plugs are used in the industry, and the presence or absence of leaks is detected by loosening these plugs. Another common method is to use detachable hoses, which can also be detected for leaks by taking them apart. However, the above-mentioned known method is relatively basic, and using the above-mentioned detection method to find the location of the leak will take a lot of time and a lot of work, because the hose and the plug need to be loosened in turn until the location of the leak is found.

British published patent No. A 2060800 discloses a device that can be used in the fuel pipeline of the double wall of the engine. With this arrangement, leaked fuel can escape from the flow channel formed by the outer wall. According to the records of this published patent, this device needs to be used in cooperation with the branch pipe of the fuel injection pump and the outlet of the device should be connected with the public discharge pipeline. According to the specification of this document, the device also has a piston member which is displaced when a leak occurs so that the leaked fuel can be introduced through the device into the discharge line, while the plug body of the piston member protrudes to indicate the leak. However, it is difficult to apply this arrangement especially to large engines equipped with a common rail reservoir injection system, the fuel piping system of which is very bulky and has many branch lines. If this public solution is adopted, the system becomes very decentralized and thus difficult to use and maintain.

Figure 1 shows a more advanced fuel supply system. This figure schematically shows a part of a fuel supply system applicable to an internal combustion engine, especially a large internal combustion engine. Large internal combustion engines refer to main and auxiliary internal combustion engines for generating heat and/or electricity, which may be applied to ships or power plants, for example. Typically, such large internal combustion engines are diesel engines. More precisely, Figure 1 shows an example of what is known as a common rail diesel engine.

For the sake of clarity, the internal combustion engine is shown very schematically and this internal combustion engine may be of a known type. Mainly the cylinder 13 and the cylinder head 12 are shown in more detail. Two of the cylinders 13 show the upper piston 23, and the fuel is sent from the fuel tank 2 to each high-pressure pump 4 by the fuel delivery pump 1 through the fuel pipeline 3, where the fuel is boosted to the injection Sufficient injection pressure required by oiler 11. The high-pressure pump 4 communicates with the pressure accumulator 6 , and the fuel is delivered to the pressure accumulator 6 by the high-pressure pump 4 , and then delivered to the fuel injector 11 from the pressure accumulator through the fuel manifold 7 .

Some fuel is continuously leaking from the nozzle 11 located at the cylinder head 12, and it will be sent to the continuous leakage channel 15 connected with the fuel recovery system through the leakage pipe 14. There is also some normal leaked fuel at the high pressure pump 4 , which will be sent to the leak pipe 15 through the leak pipe 24 .

Therefore, the example in FIG. 1 preferably includes a device assembly that sends fuel to the pressure accumulator 6 via the high-pressure pump 4 and delivers fuel from the pressure accumulator to the engine cylinder 13 through the fuel injector 11 . Each pressure accumulator 6 is connected to at least two fuel injectors 11 and is equipped with its own high-pressure pump 4 . The high-pressure pump 4 is connected to the pressure accumulator 6 through the fuel supply pipe 5 , the pressure accumulator 6 is connected to the fuel injector 11 through the fuel manifold 7 , and the pressure accumulator 6 is connected through the fuel connecting pipe 8 . Therefore, at least the above-mentioned fuel supply pipe 5, fuel manifold 7 and fuel connection pipe 8 are formed by double-walled pipes, the outer flow space 10 (for leaking fuel) being communicated with each other. Therefore, if a fuel leak occurs somewhere in the system, the leaked fuel will flow through the outer flow space 10 and the outlet flow passage 20 into the leaking fuel tank 21 and the leaking indicator 22 connected to the leaking fuel tank 21, which The leak indicator 22 may be a liquid level sensor or an optical sensor used to indicate whether the leaking fuel tank is full and to detect leaks. The leaked fuel will be discharged from the leaked fuel tank 21 of the engine through the throttling pipe 27 , and the fuel with actually relatively high pressure flows in the inner layer flow space 110 .

In order to locate the fuel leakage location, the above-mentioned fuel connection pipeline 8 is provided with at least one fuel leakage detection device 18 , and the detection device 18 can communicate with the outer flow space 10 of the pipeline system through the connection pipeline 17 . The fuel leak detection device 18 comprises a number of leak detection elements, via which the above-mentioned outer flow spaces 10 can be flow-connected with each other or can be isolated from each other. The detection device is also communicated with the outlet flow channel 20 through the connecting pipeline 19 .

As also shown in FIG. 1 , the fuel connection line 8 , which connects the pressure accumulator 6 in the fuel supply system, is also provided with a partition wall 9 or the like. By means of this partition wall 9 the outer flow space 10 in the supply system and the supply system itself are separated into several separate parts, two of which are shown in the figure. The first part includes one of the pressure accumulators, the fuel injector connected with the pressure accumulator and the fuel delivery pump. Correspondingly, the second part includes another pressure accumulator, a fuel injector and an oil delivery pump connected to the pressure accumulator. Both parts of the outer flow space 10 are connected with a fuel leakage deep detection device 18 . In this case, the fuel leak detection device 18 provided in the fuel connection line is not always necessary, but in some fuel supply systems and engines, the location of fuel leaks can only be located mainly by contact with the pressure accumulator. 6 connected fuel leak detection device to measure.

The area 25 outlined in dashed lines in FIG. 1 depicts what is known as the engine heat tank. The figure thus shows the device placed inside the hot box.

Fig. 2 is a sectional view of the hot box. The hot box is the area bounded by the cover 28 and the engine block and other components 29 which utilizes the thermal energy generated by the engine. Since the cover 28 can be opened, the status of the device can be easily checked. For reasons of simplification, the fuel leak detection device 18 and the necessary connecting lines 17 , 19 are only indicated by the line 210 in FIG. 2 . In addition, FIG. 2 is a schematic schematic diagram, so not all devices that may be placed in the hot box are shown in the figure. FIG. 3 is an external view of the internal combustion engine 31 . The above-mentioned heat box is usually located at the upper edge of the engine, where its cover 28 can be opened.

Figure 4 shows another application of the fuel leak detection device. FIG. 4 shows in detail, by way of example, the localization of fuel leaks in the high-pressure lines 5 , 7 and 8 , ie at connections of the high-pressure lines, for example at the cylinder head or the pressure accumulator. In this exemplary embodiment a pin 41 cooperating with the outer flow space 10 of the pressure accumulator 6 , a housing 42 cooperating with the pin 41 and a spring-loaded ball 43 are used. A spring loaded ball 43 or the like maintains the pin 41 in the normal position by means of a groove or similar structure (not shown) provided in the pin 41 and cooperating with the ball 43 or the like. When fuel leakage occurs at the pipeline 8 (or other high-pressure pipeline, the outer flow space 10 of the high-pressure pipeline communicates with the pipeline 8 through a separate channel shown in Figure 4), the pressure in the pressure space 44 of the above-mentioned pin housing begins to rise. high. By judicious design of the above-mentioned spring loaded ball 43 or similar and groove or similar structure, it is possible to determine the pressure in the pressure space 44 which causes the pin 41 to start moving outwards in the pin housing 42 until it is shown in FIG. location. In this case, the leaking fuel is discharged forward through the channel 45 until it flows into the leak indicator device 22 . Therefore, here the pin 41 serves as an operating element arranged to cooperate with the wall of the pressure accumulator 6 . Under the influence of the pressure of the leaking fuel, the position of the pin relative to the pressure accumulator can change, and based on the position of the pin relative to the pressure accumulator, the leaking fuel can be directed into the outer flow space of the fuel line to detect the leak. According to the solution of this embodiment, leaked fuel cannot flow out of the system even during the localization phase. However the leak is indicated by the pin sticking out of the housing. As can be seen in Figure 4, the use of pins makes the setup of the system complex and costly.

One of the problems associated with the known solutions is also that the delay between the onset of the leak and the alarm is too long. The quantity of fuel leakage is smaller than the volume of the leakage channel, so it takes a considerable period of time from the onset of the leakage to the reaction of the warning devices such as the leakage indicating element and the leaking fuel tank. Furthermore, in some engine types, the leak passages of the high pressure lines are located outside the said hot box, so that the lines need to be cleaned after each alarm, since these lines are clogged with leaking fuel. A fairly common problem is that for leaks in high pressure piping, the adjustment of the throttle passage and leak box is often incorrect.

Brief description of the invention

The purpose of the present invention is to eliminate the problems of the prior art mentioned above. This object is achieved as stated in the claims. The idea of the present invention is to connect the leakage flow space of the high-pressure pipeline with the expansion space through a valve and to measure the pressure in the leakage flow space. The valve, for example a non-return valve, provides the operationally necessary limitation of the volume of the flow space for pressure measurement and at the same time acts as a drain for possible excess pressure and leaking fuel.

A direct channel on the outside of the engine, such as a trough or pipe, acts as an expansion space through which possible leaking fuel (and the resulting overpressure) can escape to the outside world. In practical applications, it is also necessary to cooperate with a leaking fuel collector connected to the outlet of the above passage. Another preferred way is to use the continuous leakage channel connected with the fuel recovery system as an expansion space. The advantage of adopting the continuous leakage channel is that the continuous leakage channel will be pre-installed in the internal combustion engine, so it is easy to arrange the leakage pipeline with the valve between the high-pressure pipeline and the normal leakage pipeline. The combined volume of the leakage conduit and the leakage flow space together form a valve-limitable volume in which the pressure sensor can measure the pressure.

Therefore, the present invention relates to a device for leakage in a high-pressure line in an internal combustion engine, which device comprises at least one valve and at least one pressure sensor, in which device the leakage line communicates with the expansion space through the above-mentioned valve, in which device the pressure The sensor communicates with the common flow space consisting of the leakage pipe and the outer flow space.

Description of drawings

The present invention is described below with reference to the accompanying drawings, in the accompanying drawings,

Fig. 1 is a schematic diagram of an example of a leakage device for a high-pressure pipeline in the prior art.

FIG. 2 is a cross-sectional view of an example of the device shown in FIG. 1 .

Fig. 3 is an external view of an example of an internal combustion engine.

Figure 4 is a schematic diagram of one example of using a fuel leak indicator pin.

Fig. 5 is a schematic diagram of an example of the device of the present invention.

FIG. 6 is a cross-sectional view of an example of the device shown in FIG. 5 .

Description of the invention

Figure 5 shows an example of a device according to the invention. The device is based on that shown in Figure 1, but modified to comply with the present invention. In this example, the outer flow space 10 of the high-pressure line 8 connected to the pressure accumulator 6 is connected via a leakage line 53 to the continuous leakage channel 15 of the internal combustion engine. A valve 51, preferably a non-return valve, is arranged on this leakage line 53 . The valve 51 can limit the total volume of the outer flow space 10 and the volume of the leakage pipe connected to the outer flow space 10 . It is worth noting that only that part of the leakage line volume lying between the valve 51 and the high pressure line 8 is included in the above-mentioned restricted total volume.

The pressure within this confined bulk volume is measured by a pressure sensor 52 . The pressure sensor 52 is preferably provided with an output for transmitting measured pressure data to eg a control center. When a leak occurs in the above-mentioned high-pressure pipeline, the pressure value of the above-mentioned volume limited by the valve 51 will rise rapidly, and the pressure sensor 52 will respond at this time. Thus, the delay between leak and alarm is minimized.

Fuel that has leaked into the outer flow space 10 , that is, leaked fuel, is discharged into the continuous leakage channel 15 through the valve 51 that opens due to the pressure increase. Therefore, the above-mentioned valve 51 can not only provide a restricted volume (that is, the common flow space formed by the leakage pipe and the outer flow space 10 ), but also provide an outlet for the leaked fuel to flow out of the engine. The device is also equipped with a pressure sensor.

As shown in FIG. 5 , the high-pressure line 8 is divided into two separate volumes by a partition element 9 (partition wall). The pressure in the first volume is measured by a pressure sensor 52 connected to the leakage line 53 ; the pressure in the second volume is measured by the pressure sensor 52 connected directly to the high pressure line 8 . The position of the pressure sensor therefore depends on the configuration of the system connected to the volume exposed to the measuring use. Likewise, the leakage conduit 53 can also be realized in a manner suitable for the application. For example, leaking ducts can be drilled or milled channels.

The position of valve 51 also depends on the configuration of the system. If the length of the leakage pipeline is very short, the position of the valve 51 does not have much room for selection; if the length of the leakage pipeline is relatively long, the position of the valve 51 can be set relatively freely. Figures 5 and 6 show that the aforementioned normal leaking piping is preferably located inside the hot box.

The leakage duct may also communicate with a channel, if preferably one, which forms a rapid and as direct as possible access to the outside of the engine. Therefore, the above-mentioned continuous leakage channel connected to the fuel recovery system of the engine for discharging the leaked fuel from the high-pressure line out of the engine is unnecessary. Even, the leak pipe itself may be formed with a passage directly communicating with the outside of the engine. Which of the above architectural concepts to choose depends on the construction of the rest of the system. However, since a continuous leak passage is installed in most engines, it is always conceived to drain fuel out of the engine through the continuous leak passage. On the other hand, in order to prevent environmental pollution, it is better to use the passage leading the leaked fuel directly out of the engine in conjunction with a collector located outside the engine to collect the leaked fuel. Therefore, it is common practice for most engines to utilize existing continuous leak paths.

In the embodiment of the present invention, due to the use of the normal leakage channel inside the hot box, there is no need to clean the channel separately after the alarm. The heat from the hot box keeps the leaked fuel flowing in the channels so it doesn't freeze. When a leak occurs, the leak channel is still in good condition to prepare for the next possible leak. It is therefore advantageous that operating elements, pressure sensors and valves etc. can all be arranged inside the hot box.

Since the measurement is done by the pressure sensor, the leakage fuel tank 21 and the throttle pipe 27 connected thereto are unnecessary.

The pressure in the inner flow space of the high-pressure pipe is generally about 1600 bar maximum (in CR engines), so when the pipe ruptures, this pressure is released into the outer flow space 10 and finally into the leakage pipe 53, thereby The pressure is also reduced. As the pressure rises, the valve also opens to release the pressure into the external space. The above-mentioned external space is referred to herein as an expansion space. As can be concluded from the described examples, a direct path from the engine or a continuous leak path connected to the engine's fuel recovery system can serve as room for expansion. Other structural concepts are also conceivable for the required expansion space. Before implementing the arrangement of the present invention, the influence of the pressure in the leaking fuel discharge channel needs to be considered, otherwise the engine is easily damaged.

Since the pressure in the high pressure line can be released quickly enough into a sufficiently large volume, the size of the leaky line and other passages used will not cause any problems. The pressure sensor can work at a pressure difference of eg 0.1 bar and the valve 51 can work at a pressure difference of 0.2 bar. Therefore, more reliable operation of the pressure sensor 52 is activated before the above-mentioned pressure and leakage fuel are allowed to be discharged into the expansion space. Of course, the pressure sensor and valve may have other operating parameters as well.

Costs are saved since no separate channel system or drive is required in the engine configuration of the invention. Comparing FIG. 5 with FIG. 1, it can be seen that it is not necessary to have a fuel oil leak detection device 18 with the necessary connecting lines 17, 19, an outlet flow channel with the required devices and a leak box 21 in the structural concept of the present invention . The cost of the pressure sensor and valve is lower than the reduced cost.

It is also possible to have separate control elements for each cylinder of the engine, so that the pressure sensor and valve combination described above can be connected to each cylinder's injector line, ie the high pressure line that delivers fuel to the cylinder. Pressure sensors and/or valves can also be connected to the high-pressure line between the high-pressure pump and the pressure accumulator or to the high-pressure line between the pressure accumulators.

Thus, the invention achieves a shorter delay between fuel leak and warning and a low-cost construction concept. Furthermore, the invention also reduces the need for maintenance and increases reliability since no cleaning of the leak channel system is required after a possible leak.

The embodiments of the fuel leak detection device described above are independent of each other, but it is also possible to select several basic concepts operating according to different embodiments in the same engine. It is also possible within the scope of the invention to combine the operating principles of the different embodiments. The above-mentioned engines may be standard engines, common rail engines or other types of engines. The engine may be any type of internal combustion engine, preferably a diesel engine.

It is therefore clear that the above-described technical solutions are shown as examples only, and that the invention is therefore not limited to the above-described embodiments, but that other modifications are conceivable within the scope of the appended claims.

Claims (14)

1. A device for high-pressure pipeline leakage in an internal combustion engine, in which, said high-pressure pipeline is a double-walled fuel pipeline, which includes an inner layer flow space for fuel oil and a possible The outer flow space of the leaked fuel, the device includes at least one leak pipe communicating with the outer flow space and leading out the possible leaked fuel, characterized in that the device includes at least one pressure sensor and at least one valve, the The valve and the pressure sensor are separate components in which the leakage pipe is connected to the expansion space through the valve, and in which the pressure sensor is connected to the leakage pipe and the outer flow space. The flow spaces are connected; in this case, due to a possible leak of fuel, a rising and/or rising pressure in the common flow space is detected in the pressure sensor, an alarm is issued and the opening of the valve is carried out , leading the leaked fuel into the expansion space. 2. The device according to claim 1, wherein the expansion space is formed by a continuous leakage passage of the engine, and the continuous leakage passage communicates with a fuel recovery system of the engine. 3. The device of claim 1, wherein the expansion space is formed by a passage outside the internal combustion engine. 4. The apparatus of claim 1, wherein said leakage line, valve and pressure sensor are all located in a hot box. 5. The apparatus of claim 3, wherein said leak line, valve and pressure sensor are all located in a hot box. 6. The apparatus of claim 2, wherein said leak line, valve, pressure sensor and continuous leak channel are located in a hot box. 7. The device according to claim 2 or 6, characterized in that the continuous leakage channel communicates with the fuel recovery system through a pipeline. 8. The device according to any one of claims 1 to 6, characterized in that the pressure sensor is provided with an output for transmitting measurement data from the pressure sensor. 9. The device according to any one of claims 1 to 6, characterized in that the pressure sensor and/or valve is connected to a high-pressure pipe supplying fuel to the cylinders. 10. The device according to any one of claims 1 to 6, characterized in that the pressure sensor and/or the valve are connected to a high-pressure pipeline between the high-pressure pump and the pressure accumulator. 11. The device according to any one of claims 1 to 6, characterized in that the pressure sensors and/or valves are connected to a high pressure line between the pressure accumulators. 12. A device as claimed in any one of claims 1 to 6, characterized in that the valve is a non-return valve. 13. The device according to any one of claims 1 to 6, characterized in that the internal combustion engine is a common rail engine. 14. The device according to any one of claims 1 to 6, characterized in that the internal combustion engine is a diesel engine.

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