HUP0900736A2 - Equipment and process for electronically controlled injection of liquified or compressed gas into diesel engines - Google Patents

Description

Representative: Pintz and Partners Patent, Trademark and Law Office, Budapest

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Device for electronically controlled dosing of liquefied or compressed gas into diesel engines for diesel-gas mixed-fuel vehicles and method for its application

The invention relates to a device for electronically controlled dosing of liquefied or compressed gas into diesel engines for diesel-gas mixed fuel vehicles and a method for its use. The device is particularly suitable for installation in a diesel engine, either mechanically or electronically controlled, or for retrofitting.

It is known that the use of gas fuel, especially stored in liquid form, would be very beneficial for the operation of vehicle engines for environmental and financial reasons, if its use were not hindered by numerous obstacles. Therefore, alternative vehicles, either pure gasoline or pure gas, have become more widespread, while retaining the advantages of operating a gasoline engine independent of the gas supply.

Although diesel engines generally pollute the air less than gasoline engines and emit less carbon monoxide and unburned hydrocarbons, it can still be disadvantageous that after the diesel fuel is injected into the cylinder, during the short period of its distribution, the possibility of forming a homogeneous mixture deteriorates, as a result of which, if the engine is worn out, the adjustment is incorrect, etc., black smoke is released into the air. But a diesel engine cannot operate purely on gas - without significant modification - because the gas-air mixture compressed in the cylinders cannot explode without a spark plug. Therefore, the idea arose that gas should be used in a conventional diesel engine only to improve combustion. The great advantage of this is that with the gas-air mixture, the mixing, expansion and explosion of the diesel fuel becomes more perfect, and the engine's performance becomes more uniform and greater.

As a result of the above recognition, there are several known solutions for adding gas to diesel engines. One such solution is the solution in the Hungarian patent description entitled “Method and apparatus for adding gas oil and propane butane gas to diesel engines” with registration number HU 171 169. The essence of this is that only gas oil is added up to 70% of the engine's power, and then a mixture of gas oil and gas. This solution only helps with gas addition when the diesel engine is under high load, although this would be necessary in the medium and most frequently used power ranges.

The description entitled "Fuel dosing device for gas diesel engine" with the also Hungarian case number P8803102 describes an outdated, insufficiently presented mechanical solution for the simultaneous control of liquid and gaseous material.

The essence of the solution of the patent description entitled “Method and device for operating vehicles equipped with a diesel engine, with a mixture of diesel oil and propane-butane gas” with registration number HU 223 128 is that the diesel oil-gas automatically combines proportionally controlled gas dosing with a mechanical, rack-and-pinion metering pump, for which an electronic control unit is used. Today, most modern diesel engines use electronic gas dosing and gas injection, for which this equipment is no longer suitable. Installing sensors on the rack and incorporating them into the engine block requires partial conversion of the engine.

According to the English patent specification GB 2437098 entitled “Dual-fuel engine with suitable fuel regulators”, the engine is capable of operating on both types of fuel, not a mixture of them. Therefore, it has ignition and a control that detects the fuel used and performs the corresponding adjustment. The solution according to the invention means a separate special engine design and control. This is not a commonly used diesel engine, it cannot be used as a retrofitted gas dosing device, but a complete, completely new engine design.

The device according to the patent document US 7,509,209 entitled “Method and apparatus for operating a multi-fuel engine” has a common electronic control device for the diesel engine and gas metering, which can be connected to the existing components of the engine, in order to control the operation of the multi-fuel engine. The engine system can be mechanically controlled or electronically controlled. In one solution, the first fuel is diesel oil, the second is natural gas. The engine operation is ensured by operating instructions and software linked to the various engine characteristic curves. The gas metering and diesel injection control units form a complete device in the vehicle, therefore they cannot be disassembled into separate devices, and therefore cannot be installed later. The whole solution is complicated and expensive.

The object of the invention is therefore to implement a device and method by which a mixed, dual diesel-oil-gas engine is created, which is free from the defects of previous solutions and can be retrofitted into currently used electronically controlled or mechanically regulated diesel engines without changing or modifying their existing control system. It is also an object that the emission control system of the vehicle is not modified by installing the device according to the invention, while preserving the original diesel fuel system. Its installation should be simple, its operation should not be too complicated and it should be able to operate even with a single signal taken from the engine, as well as with its own sensors.

The invention is based on the recognition that if we install a sampling nozzle in the air intake throat of the diesel engine, and by further conducting the air pressure prevailing in the air intake throat through the pipeline connected to the outlet of the sampling nozzle, we use it for the feedback control of the gas injector, gas metering valve and pressure reducing device, we have already achieved our goal, we have fulfilled our task. If we supplement all this with the installation of a knock sensor and the combined design of the gas nozzle with a new restrictor calibrated to the size of the engine, we will also achieve better, more reliable operation of the engine.

The invention is a device for electronically controlled dosing of liquefied or compressed gas into diesel engines for mixed diesel-gas vehicles, which can be retrofitted into the vehicle, and comprises a gas tank equipped with a multi-valve and a gas filling valve, a dosing valve and a pressure reducing device in the high-pressure gas circuit, an electronic control unit regulating the gas quantity dosing in the low-pressure gas circuit, and a device for supplying gas to the air intake throat of the diesel engine, and the heating part of the pressure reducing device is connected to the cooling water system of the diesel engine.

The essence of our invention is that a sampling stub is built into the air intake throat of the diesel engine, which is connected via pipelines partly to the pressure reducing device and partly to an evaluation unit that compares and evaluates the air pressure arriving in the air intake throat and through the gas injection valve.

In one advantageous embodiment of the device according to the invention, a knock sensor is mounted on the diesel engine, which is preferably connected to a knock sensor comprising an analog-to-digital signal converter, and the knock sensor is connected to the gas plant data processing and control central unit via a signal transmission chain, where the signal transmission chain preferably also comprises a gas plant data transmission wiring harness, a connecting strip and a connecting wiring harness.

In a further advantageous embodiment of the device according to the invention, the member for introducing gas into the air intake throat of the diesel engine is designed as a gas injection nozzle, which is conveniently connected to the gas outlet of the gas injection valve via a reducer and a connecting pipe calibrated to the size of the diesel engine.

It is advantageous if the gas injection nozzle is integrated with a restrictor calibrated to the size of the diesel engine.

In the device according to the invention, the end of the gas injection nozzle extending into the air intake throat has a design - preferably a nozzle head - that promotes the mixing of air and gas.

In the preferred embodiment of the invention, the sampling port built into the air intake throat is connected via a pipeline to the pressure regulating membrane in the pressure reducing member.

According to the invention, it is further advantageous if the electronically controlled gas dosing regulating and monitoring device in the device has a diagnostic and programming unit.

Our invention also provides a method for using the device for electronically controlled dosing of liquefied or compressed gas into diesel engines, as well as mixed diesel-gas vehicles, in which high-pressure, liquefied or compressed gas stored in gas tanks is fed through a valve into a pressure reducing device, then the low-pressure gas obtained here is fed further into a gas volume regulator controlled by an electronic control unit, and the electronically dosed gas exiting the gas volume regulator is fed into the air intake throat of the diesel engine.

The essence of our method is to install a sampling stub in the air intake throat of the diesel engine, with the help of which the current air pressure prevailing in the air intake throat - which can be not only normal, but also turbocharged or supercharged - is used for control, during which part of the air is led through a pipeline to the pressure reducing device, where the pressure reducing device is controlled by the air pressure, preferably with the help of its membrane, the other part of the air is led through a pipeline to the pressure comparing and evaluating unit, where this air pressure is compared with the gas pressure received from the gas injection valve, which was received through the gas pressure transmitting tube, and then with the electronically controlled gas dosing regulating and monitoring device, the gas injection valve is regulated through the gas quantity dosing control line so that the gas pressure exiting the gas injection nozzle is always higher than the pressure in the air intake throat.

A further advantageous embodiment of the method according to our invention is to mount a knock sensor on the diesel engine, with the help of which - preferably using a piezoelectric crystal - the analog signal of the knock is generated, then the obtained analog signal is passed on to the knock transmitter, where the analog signal is converted into a digital signal, and the digital signal thus obtained is passed on to the regulating and monitoring device via the gas plant data transmission wiring harness, from where the signal is passed on via a connection strip and a connecting wiring harness to the gas plant data processing and control central unit, and in the event of a knock being detected, the gas supply is stopped in the device, then after the knock has ceased, the gas supply is restarted - preferably gradually - by monitoring and evaluating the other signals of the gas plant transmitters.

The apparatus and method according to the invention are described in more detail through drawings, where the

Figure 1. is a layout diagram of a device for electronically controlled dosing of liquefied or compressed gas into a diesel engine, the

Figure 2. Enlarged detail of the device according to Figure 1 with the gas tank and associated pipelines, the

Figure 3 is a front view of the gas injection nozzle (32),

Figure 4 is a longitudinal sectional drawing of the gas injection nozzle,

Figure 5 is a cross-sectional drawing of the gas injection nozzle A-A,

Figure 6 shows an enlarged cross-sectional view of the nozzle head (57).

The upper part of Figure 1 shows the arrangement and block diagram of the known, gas-free, modem, electronically controlled diesel engine 5 and the most important units serving it, the diesel engine sensors 3 and the diesel plant data transmission wiring harness 4. The most important part of the regulation and control organ 5 is the diesel engine data processing and control central unit 7 and the diesel engine control memory 9. The communication and the transmission of the output and input signals are ensured by a connection strip 6 and a connecting wiring harness 8. The diesel fuel injection valve 1, into which the diesel fuel 2 is also fed, is electronically controlled via the valve control wire 10. It is indicated in the drawing with a dashed line that the diesel engine 40 has an electronically controlled diesel fuel injection valve 1 corresponding to the number of cylinders. In Figure 1, six cylinders are marked. All of these, including the air filter 42, the organs and units that ensure the operation of the diesel engine 40 without gas operation, do not belong to the device according to our invention. The diesel engine 40 is connected to the device according to our invention only by an injection signal transmission line 12. This satisfies the condition that the device according to the invention does not directly interfere with the existing operation of the diesel engine 40, and the device can be installed or removed later.

The rest of Figure 1 shows the connection of the device according to the invention to the diesel engine 40 after installation. Figure 2 shows an enlarged part of the device according to the invention, complete with the gas tank 48, the gas filling valve 49 and the multi-function multivalve 50.

In Figures 1 and 2, we can see that the device according to the invention includes the metering valve in the high-pressure gas circuit, in the exemplary embodiment a solenoid valve 37 and a pressure reducing device 35, which also serves as an evaporator, and also an electronic gas metering and control device 13 in the low-pressure gas circuit, and also a device for supplying gas to the air intake throat 41 of the diesel engine 40, which according to our invention has a new gas injection nozzle 32. The heating part of the pressure reducing device 35 is connected to the cooling water system of the diesel engine 40 by means of the inlet pipe 51 and the outlet pipe 52, so that the evaporator of the pressure reducing device 35 is always at the appropriate temperature. The gas dosing regulating and monitoring device 13 has a gas plant data processing and control central unit 15, a gas plant control memory 17, and furthermore a connecting strip 14 and a connecting wire bundle 16 serving these.

According to the invention, a sampling port 47 is installed in the air intake throat 41 of the diesel engine 40, which is partly connected to the pressure reducing member 35 via the pipeline 44 and partly connected via the pipeline 43 to an evaluation unit 28 comparing the pressure in the air intake throat 41 and the gas injection valve 30.

In Figures 1 and 2, the operation of the device according to the invention can best be followed by presenting the method according to our invention. First, at a suitable filling station, the gas tank 48 of the vehicle is filled with liquefied or compressed gas through the gas filling valve 49. It should be noted here that, in accordance with safety regulations, the gas tank 48 is also equipped with a multi-function multi-valve 50, known per se, which also measures the fuel level of the gas tank 48 and the pressure of the gas contained therein. In addition to the filling and connection valves, the multi-valve 50 is also equipped with a pressure-limiting safety valve. The gas stored in the gas tank 48 is fed through a high-pressure pipeline 38 to a metering valve, preferably the solenoid valve 37. See also Figure 2. The high-pressure gas is fed from the solenoid valve 37 through the high-pressure pipeline 36 to the pressure reducing device 35, where low-pressure gas is obtained by evaporation. Evaporation involves heat removal, therefore, to ensure the appropriate operating temperature, the heating part of the pressure reducing device 35 is connected to the cooling water system of the diesel engine 40 through the inlet pipe 51 and the outlet pipe 52. From the pressure reducing device 35, the low-pressure gas is fed through the gas supply pipeline 46 to the gas injection valve 30 designed according to our invention, which is electronically controlled by the gas dosing regulating and monitoring device 13. The gas supplied by the gas injection valve 30 is led to the gas injection nozzle 32 via a connecting pipe 39 and a reducer 31 calibrated to the size of the diesel engine 40, which is used to deliver the gas to the air intake throat 41 of the diesel engine 40. In order to achieve better, more perfect gas-air mixing, the protruding part 56 of the gas injection nozzle 32 is provided with a nozzle head 57. See also Figure 3. It is also possible to integrate the gas injection nozzle 32 and the reducer 31 calibrated to the size of the diesel engine. Thus, by simply replacing the gas injection nozzle 32, it becomes possible to service diesel engines of different types and sizes 40.

According to our invention, a sampling nozzle 47 is also installed in the air intake throat 41 of the diesel engine 40, with the help of which the current air pressure prevailing in the air intake throat 41 - which can be not only normal, but also supercharged, turbocharged or supercharged - is used for control. Thus, the device according to our invention automatically becomes suitable for any diesel engine 40 with not only normal, but also supercharged, turbocharged or supercharged charge. From the sampling nozzle 47, a part of the air is led through a pipeline 44 to the pressure reducing device 35, where the pressure reducing device 35 is controlled by the air pressure, preferably with the help of its membrane 58. The other part of the air from the sampling port 47 is led through the pipeline 43 to the pressure comparison evaluation unit 28, where this air pressure is compared with the gas pressure from the gas injection valve 30, which was received through the gas pressure transmission pipe 45. The result of the comparison is communicated to the gas dosing control and monitoring device 13 via the evaluation line 27. The electronically controlled gas dosing control and monitoring device 13 then controls the gas injection valve 30 via the control line 29 so that the gas pressure exiting the gas injection nozzle 32 is always higher than the pressure in the air intake throat 41.

However, the device according to our invention can be installed not only on the electronically controlled diesel engines 40 that are widespread today for the purpose of implementing mixed diesel oil-gas operation, but also on mechanically controlled diesel oil injection engines. In this case, too, the only control signal required for the device according to the invention is provided by the mechanically controlled diesel engine signal source 11, which is indicated by a dashed line in the drawing.

The preferred embodiment of the device according to the invention also has 18 gas operation sensors and a gas operation data transmission wire harness 19 transmitting their signals. Of the 18 gas operation sensors, the role and structure of the speed sensor 20, the speed sensor 21, the accelerator pedal angle sensor 22, and the throttle valve angle sensor 25 are known. Therefore, their use, structure and connection, which vary depending on the type of engine and are necessary, will not be described separately. We would only like to draw your attention to the fact that in our device, the gas supply is stopped during engine braking by means of the throttle valve sensor 25, and the gas supply is also stopped when the vehicle is stationary by means of the speed sensor 21. For careful and safe operation, the pressure reducing device 35 is equipped with an engine cooling water temperature gauge 34, the signal of which is transmitted to the gas dosing control and monitoring device 13 via the temperature data line 33.

The device according to the invention preferably also has a knock transmitter 23 and a knock sensor 24 mounted on the diesel engine 40. A knock sensor 24 is mounted on the diesel engine 40, which is preferably connected to a knock transmitter 23, which preferably includes an analog-to-digital signal converter, via an electrical wire. Furthermore, the knock transmitter 23 is connected to the gas plant data processing and control central unit 15 via a signal transmission chain for signal transmission. The signal transmission chain preferably also includes a gas plant data transmission wire harness 19, a connecting strip 14 and a connecting wire harness 16.

According to our method, a knock sensor 24 is mounted on the diesel engine 40, and an analog signal of the knock is generated using a piezoelectric crystal, and the resulting analog signal is then passed on to the knock transmitter 23, where the analog signal is converted into a digital signal. The digital signal thus obtained is then passed on to the gas dosing control and monitoring device 13 via the gas plant data transmission wiring harness 19, where, in the event of a knock being detected, the gas dosing is stopped in the device. After the knock has stopped, the gas dosing is restarted - preferably gradually - by monitoring and evaluating the other signals of the gas plant transmitters 19.

The device according to the invention, in accordance with the requirements of the time, is also equipped with a diagnostic and programming unit 26, which is connected to the gas dosing control and monitoring device 13. The task of this unit is to electronically detect any malfunction and, if desired, to adjust the operation of the device.

The gas injection nozzles 32 according to the invention are described in detail in Figures 3, 4, 5 and 6. Figure 3 shows a front view of the gas injection nozzle 32, and Figure 4 shows a longitudinal sectional view, where the cord threaded part 53, nozzle housing 54, external threaded part 55, protruding part 56 into the air intake throat 41 and the nozzle head 57 are shown. The connecting pipe 39 is connected to the gas injection nozzle 32 via the cord threaded part 53, preferably via a reducer 31. The gas injection nozzle 32 is screwed into the air intake throat 41 by means of an external threaded part 55. The inventive design of the nozzle head 57 of the protruding part 56 extending into the air intake throat 41 is shown in an enlarged manner in Figure 6. Figure 5 is a sectional drawing of the gas injection nozzle 32 along line A-A. If the reducer 31 is integrated with the gas injection nozzle 32, it is formed inside the nozzle housing 54, for example by narrowing it.

The advantage of the device is that it can be installed on any diesel engine vehicle in circulation, without directly interfering with its operation, the original fuel system remains unchanged and the emission control system is not modified. The use of the device is independent of whether the diesel engine has a normal, naturally aspirated, turbocharged or supercharged air supply. Its installation is simple and its operation is not complicated. It can also operate with a single signal taken from the engine, which signal can be conveniently obtained from the control of the diesel fuel injection valve. However, if necessary, the device can also operate with a speed signal, for example in a mechanically controlled diesel engine. In this case, one of the simple ways to generate the speed signal is with a Hall sensor. By installing and using the knock sensor, we achieve safer operation and avoid overloading the diesel engine.

Another great advantage of the device over other known gas injection systems is that it can use the same high-performance gas injection valve within a wide power range. Namely, the gas flowing out of the gas injection valve that supplies the gas is fed into the air intake throat through a separate gas injection nozzle equipped with a calibrated restrictor depending on the type and power of the diesel engine, or integrated with it. Another advantage of this is the longer-term injection, the reduction of the pulse and fluctuation of the gas dosing, and at the same time ensuring a uniform gas supply. These advantages are further increased by the design of the gas injection nozzle and the nozzle head according to the invention, since, thanks to its design that promotes gas mixing, it creates better air-gas mixing than the known gas/air mixing heads, which even limit and obstruct the amount of air entering the diesel engine.

Claims (9)

PATENT CLAIMS 1. Device for electronically controlled dosing of liquefied or compressed gas into diesel engines for diesel-gas mixed-fuel vehicles, which can be retrofitted into the vehicle, comprises a gas tank equipped with a multi-valve and a gas filling valve, a dosing valve and a pressure reducing device in the high-pressure gas circuit, an electronic control unit regulating the gas quantity dosing in the low-pressure gas circuit, and a device for supplying gas to the air intake throat of the diesel engine, the heating part of the pressure reducing device being connected to the cooling water system of the diesel engine, characterized in that a sampling stub (47) is built into the air intake throat (41) of the diesel engine (40), which is partly connected to the pressure reducing device (35), partly to an evaluation unit (28) comparing the pressure in the air intake throat (41) and the gas injection valve (30) via pipelines (44, 43). 2. The device according to claim 1, characterized in that the diesel engine 40 is equipped with a knock sensor (24), which is preferably connected to a knock transmitter (23) comprising an analog-to-digital signal converter, and the knock transmitter (23) is connected to the gas plant data processing and control central unit (15) via a signal transmission chain, where the signal transmission chain preferably also includes a gas plant data transmission wiring harness (19), a connecting strip (14) and a connecting wiring harness (16). 3. The device according to any one of claims 1-2, characterized in that the member for introducing gas into the air intake throat (41) of the diesel engine is designed as a gas injection nozzle (32), which is conveniently connected to the gas outlet of the gas injection valve (30) via a reducer (31) calibrated to the size of the diesel engine and a connecting pipe (39). 4. The device according to any one of claims 1-3, characterized in that the part (56) of the gas injection nozzle (32) extending into the air intake throat (41) is designed to promote the mixing of air and gas, — preferably has a nozzle head (57). 5. Apparatus according to any one of claims 1-4, characterized in that the gas injection nozzle (32) is integrated with the calibrated restrictor (31). 6. The device according to any one of claims 1-5, characterized in that the sampling nozzle (47) built into the air intake throat (41) is connected via a pipeline (44) to the pressure regulating membrane (58) in the pressure reducing member (35). 7. The device according to any one of claims 1-6, characterized in that the electronically controlled gas dosing regulating and monitoring device (13) has a diagnostic and programming unit (26). 8. Method for using the device according to claim 1, in which the high-pressure, liquefied or compressed gas stored in the gas tanks is fed through a valve into a pressure reducing device, then the low-pressure gas obtained here is fed further into a gas volume regulator controlled by an electronic control unit, and the electronically dosed gas exiting the gas volume regulator is fed into the air intake throat of the diesel engine, characterized in that a sampling stub (47) is installed in the air intake throat (41) of the diesel engine (40), with the help of which the current air pressure prevailing in the air intake throat (41) - which can be not only normal, but also tough, turbo or compressor - is used for control, during which part of the air is fed further through a pipeline (44) into the pressure reducing device (35), where the pressure of the air is used to control the pressure reducing device (35), preferably with the help of its membrane (58), and the other part of the air is fed further via a pipeline (43) to the pressure comparison and evaluation unit (28), where this air pressure is compared with the gas pressure received from the gas injection valve (30) via the gas pressure transmission pipe (45), and then the electronically controlled gas dosing regulating and monitoring device (13) regulates the gas injection valve (30) via the gas quantity dosing control line (29) in such a way that the gas pressure exiting the gas injection nozzle (32) is always higher than the pressure in the air intake throat (41). 9. The method according to claim 8, characterized in that a knock sensor (24) is mounted on the diesel engine (40), with the help of which - preferably using a piezoelectric crystal - the analog signal of the knock is generated, then the obtained analog signal is passed on to the knock transmitter (23), where the analog signal is converted into a digital signal, and the digital signal thus obtained is passed on to the gas dosing control and monitoring device (13) via the gas plant data transmitting wire harness (19), from where the signal is passed on to the gas plant data processing and control central unit (15) via a connecting strip (14) and a connecting wire harness (16), and in case of detection of knock, the gas dosing in the device is stopped, then after the knock has stopped, the other signals of the gas plant transmitters (18) are also monitored and evaluated, the gas dosing in the device is stopped - preferably gradually - we restart.