HK1022672A - Method and device for re-accelerating a vehicle equipped with a high-pressure compressor - Google Patents

Description

Method and device for re-accelerating a motor vehicle equipped with a high-pressure gas compressor

The present invention relates to land vehicles, and in particular to land vehicles equipped with pollution-free or pollution-reduced engines of the self-contained combustion chamber type.

The applicant has described in its published patent application WO96/27737 a pollution-reducing method for an external independent combustion chamber engine operating on the principle of a dual-energy type dual-operating mode, using a traditional fuel such as gasoline or diesel fuel (a fuel-air mixture type mono-mode operation), at low speeds, in particular in urban and suburban areas, with the addition of compressed air (or any other non-polluting gas) not including any other fuel, an air mono-mode operation meaning the addition of compressed air. In its patent application 9607714, the applicant describes such an engine device for use on a utility vehicle, such as a city bus, operating in a single mode with the addition of compressed air.

In such engines, when operating on a fuel and air mixture, the air and fuel mixture is compressed in a separate intake and compression chamber. This mixed gas is then fed into a separate combustion chamber of constant volume, maintaining the pressure, and combusted therein to increase the temperature and pressure of the mixed gas. The mixed gas passes through a delivery port connecting the combustion chamber or the expansion chamber with a decompression and exhaust chamber, and then expands in the decompression and exhaust chamber to perform work. The inflation gas is then exhausted through an exhaust pipe into the air.

When operating in a low-power air mode, the fuel nozzle is not controlled any more; in this case, shortly after the fuel-free compressed air from the intake and compression chambers has entered the combustion chamber, a small amount of additional compressed air is fed into the combustion chamber from an outer cylinder in which the air is stored at room temperature and high pressure, for example 200 bar. The small amount of room temperature compressed air meets high temperature air in the combustion chamber or the expansion chamber, is heated and then expands, increasing the pressure in the combustion chamber, and thus, power work can be released during expansion.

It is also possible to eliminate all the components of the traditional fuel-type engines and to modify the dual-operating or dual-energy (air and gasoline or air and make-up compressed air) type engines into single-mode air-compressed air type engines, so as to be better suited to urban use, for example for any motor vehicle, in particular for buses or other utility vehicles (taxis, garbage trucks, etc.).

Such engines operate only in a single mode, i.e. injection of supplemental compressed air into the combustion chamber, which is thus also the expansion chamber. Additionally, the air entering the engine may be filtered and cleaned by one or more activated carbon filters, or other mechanical, chemical, molecular sieve, or other filters to achieve a pollution-reduced engine. In this context, the term "air" may refer to "all gases without contamination".

In french patent application 9611632, the applicant also describes an on-board high-pressure compressor device for re-supplying compressed air to the air reservoir of a motor vehicle equipped with an engine as described above, the compressor being driven by a self-contained engine with an autonomous source of energy and being engaged during the supply of compressed air, with the aim of starting and filling the compressed air reservoir of the vehicle during deceleration and braking of the vehicle to recover the large amount of energy that would be dissipated during deceleration and braking of the vehicle.

However, in this apparatus, the main tube is cooled down after the main tube is filled with the high-temperature and high-pressure compressed air at about normal temperature. This method results in a significant loss of energy, particularly at the beginning of the main drum bleed. The pressure is reduced due to the temperature reduction, which leads to a reduction in the pressure in the main cylinder.

The method according to the invention provides a further solution which additionally makes it possible to accelerate the vehicle with a torque and a reserve supplementary power. The device is characterized in that it is used, in particular, in that, during the deceleration braking of the motor vehicle, a high-pressure compressor, activated by a clutch or any other coupling, generates a compressed gas at high temperature and pressure, for example 200 bar, which then acts as a brake retarder or even as a brake. The compressed gas is diverted and stored in an insulated or uninsulated cylinder called a reaccelerating cylinder, which maintains the high temperature and pressure of the compressed gas, which can be fed to the engine combustion or expansion chamber for use as motive power for restarting the vehicle. The compressed gas, because of its short residence time in the reacceleration barrel, is maintained at its highest temperature and pressure and is therefore injected into the engine combustion chamber while hot, carrying much more energy, when the vehicle is to be restarted or reaccelerated. The volume of the heat-insulating reacceleration cylinder is determined according to actual needs, and the pressure of the air inside the heat-insulating reacceleration cylinder is the same, and when the reacceleration cylinder is filled with the heat-insulating reacceleration cylinder, the air flows to the main cylinder again.

The volume and pressure of the reaccelerating cartridge can be calculated by one skilled in the art based on the frequency and average intensity of braking and acceleration in the desired application effect.

According to a preferred feature of the invention, the re-acceleration air reservoir is implemented in a variable volume system, with the aim of maintaining the compressed air stored therein at a quasi-constant pressure and temperature from the start of injection, by means assisted by a number of mechanical, pneumatic or hydraulic systems, such as springs or other systems, and in particular by means using compressed air which has been reduced to a prescribed pressure in the main reservoir. Thus, the variable capacity of the thermal isolation reacceleration avoids the drop in pressure and temperature of the compressed air associated with the injection of compressed air and allows the desired high volume of warm compressed air to be readily available for restarting the vehicle without having to wait until the reacceleration barrel is fully filled to achieve the desired operating pressure (e.g., 100 bar).

Therefore, if the driver wants to accelerate again immediately after the vehicle is decelerated or braked, a large amount of high-temperature and high-pressure compressed air in the re-acceleration cylinder can be filled into the combustion chamber or the expansion chamber in order to obtain a relatively high pressure in the combustion chamber, thereby ensuring that torque and power are obtained.

There are also various methods for maintaining the temperature of the reacceleration column, such as using ceramics, such as using fiberglass or other thermal insulation, and it is also contemplated that some non-contaminating thermal or chemical heating system could be used, all without departing from the scope of the reacceleration method of the present invention.

Other objects, advantages and features of the invention are described in the following, non-limiting example with reference to the accompanying drawings, in which:

figure 1 is a schematic view of a device according to the invention with a re-acceleration cartridge.

Figure 2 is a longitudinal section of a similar device with re-acceleration air reservoir of variable capacity and constant pressure and its pressure and temperature maintenance system.

Fig. 1 shows schematically a schematic view of a pollution-reducing engine unit comprising an inlet and compression chamber 1, a volume of combustion or expansion chamber 2 and a decompression and exhaust chamber 4. Inside the combustion or expansion chamber 2 is mounted a nozzle 22 which supplies make-up air against compressed air stored in a high pressure cylinder 23. The intake and compression chamber 1 is connected to the combustion or expansion chamber 2 by a pipe 5, the opening and closing of the pipe 5 being controlled by a sealing valve 6. The combustion or expansion chamber 2 is connected to the decompression and exhaust chamber 4 by a duct 7, the opening and closing of the duct 7 being controlled by a sealing valve 8. The intake and compression chamber 1 is supplied with air from an intake pipe 13, the opening of which intake pipe 13 is controlled by a valve 14, and upstream of which a desmutting activated carbon filter 24 is installed.

The inlet and compression chamber 1 is a piston compressor assembly in which a piston 9 sliding in a cylinder 10 is operated by a drawbar 11 and a crank 12. The decompression and venting chamber 4 controls a conventional piston motor, the piston 15 of which slides in a cylinder 16 and drives a crank 18 in rotation via a traction rod 17. The expanding air is discharged through an exhaust duct 19, the opening of which is controlled by a valve 20. The rotation of the crank 12 of the inlet and compression chamber 1 is governed by a mechanical connection 21 with the motor crank 18 of the decompression and exhaust chamber 4. The inlet line 26 of the compressor 25 is a branch of the engine inlet line 13 between the engine and the engine filter system 24. When it is rotated, the compressed air is charged into the high-pressure compressed air reserve tank 23 mounted on the motor vehicle through the exhaust pipe 27. The compressor 25 is driven by an electric motor 28 through a clutch 29, and when the clutch 29 is activated, the reserve cartridge is charged.

The compressor is also connected to the vehicle drive train 30 by a clutch 31, which clutch 31 is activated (engaged) during deceleration and braking to act as a motor brake to decelerate the vehicle and to allow high temperature, high pressure air to fill the reaccelerating drum 32, preferably having a heat shield 32A, through the branch line 27A. A valve 33 mounted in the compressor discharge duct 27 closes off the duct 27 to allow compressed air to flow through the branch duct 27A to the reacceleration drum, and when the reacceleration drum is completely filled with gas, the valve 33 closes off the branch duct 27A to allow air flow through the duct 27 to the main drum 23, if desired, to allow the on-board compressor to remain operational during braking and/or deceleration. During the reacceleration, the valve 33 also closes the duct 27A, causing a concentrated flow of compressed air to the reacceleration nozzle 22A at the pressure of the air in the cylinder 35, while disconnecting the on-load compressor 25, to avoid pressure losses in the direction of the compressor 25 and/or the outer main cylinder 23.

After the vehicle is decelerated, braked and/or stopped, if it is necessary to accelerate and restart the vehicle, the air nozzle 22A is opened to inject the high-temperature and high-pressure compressed air into the combustion chamber or the expansion chamber. After being mixed with the compressed air in the compression chamber 1, the gas enters a combustion chamber or an expansion chamber of the engine, and the pressure in the chamber is greatly increased, so that powerful power is obtained to restart the motor vehicle.

Fig. 2 shows a schematic diagram of a device with a variable capacity type reacceleration air reservoir device according to a modification of the present invention, and a pressure regulation system controlled by the pressure of the compressed air in the main cylinder 23. The reacceleration column 35 is preferably surrounded by a thermally insulating layer 35A, and consists of a small diameter hollow air cylinder concentrically extended by a larger diameter hollow cylinder 37 in which a secondary piston 38 slides in a sealed manner. The small diameter cylinder serves as a re-acceleration cylinder 35, which is connected to an intake pipe 27A and an exhaust pipe 39, and the high temperature and high pressure compressed air in the intake pipe 27A is supplied from a compressor 25 which is activated when the vehicle is decelerated and/or braked, and the compressed air in the exhaust pipe 39 flows to a re-acceleration nozzle 22A. The large diameter cylinder 37 has a medium pressure compressed air inlet conduit 40 which compressed air from the main cylinder 23 is at a very high pressure and expands through a buffer reservoir 41 to a medium pressure required and sufficient to replenish the air to the nozzle 22 during normal engine operation.

The ratio of the cylinder diameters must be such that the expansion-stop pressure in the larger diameter cylinder 37 maintains the pressure in the small cylinder selected to supply the re-accelerating make-up air to the nozzle 22A. For example, a 100 mm diameter large cylinder with an expansion termination pressure of 40 bar may maintain a pressure of about 110 bar in a 60 mm diameter small cylinder as a reacceleration cartridge. To avoid excessive pressure differentials as the piston 38 moves, the buffer reservoir 41 has a relatively large volume.

When the engine is operated in compressed air mode, the engine is supplied with room temperature make-up air, for example at 40 bar pressure, from the make-up air nozzle 22.

During deceleration, i.e. when the driver releases the accelerator or brakes, the clutch 31 is activated, so that the self-contained air compressor is started to ensure deceleration or braking. The position of the reversing valve 33 is now such that the high temperature and high pressure compressed air (for example 150 bar) in the compressor 25 flows to the reacceleration drum 35. The secondary piston 38 is moved by the compressed air in the pipe 27A and the pressure in the reacceleration cylinder 35 is made almost constant (for example 100 bar) by the action of the force exerted by the pressure in the large cylinder 37 on the face of the piston with the larger diameter. When the piston 38 has completed its full stroke, the valve 33 is re-actuated to allow compressed air to flow to the main cylinder 23. Thus, deceleration and/or braking may also be achieved by operating the compressor 25 by flowing a flow of compressed air to the outer main barrel. Once the driver wishes to re-accelerate, the re-acceleration nozzle 22A is activated to supply hot, high pressure compressed air to the combustion chamber 2, so that a relatively high pressure and a large re-acceleration torque can be obtained in the combustion chamber. In this phase of operation, valve 33 closes branch conduit 27A to concentrate the flow of compressed air under pressure in reacceleration barrel 35 towards reacceleration nozzle 22A, while compressor 25 is switched off to avoid pressure losses in the direction of compressor 25 and outer main barrel 23. The person skilled in the art is fully capable of combining injection with valve actuation control, depending on the braking and acceleration phases.

The type of self-contained high pressure compressor, the type of operating clutch, the type of insulation of the re-acceleration cylinder, the type of reversing valve 33, the manner of pressure maintenance, etc., and the different arrangement of the components in the vehicle may be varied without departing from the scope of the invention.

Claims (10)

1. A method of re-accelerating a motor vehicle fitted with a pollution-free or pollution-reduced engine, said engine comprising a separate combustion chamber (2) into which, when operating pneumatically, a quantity of pollution-free make-up compressed gas is fed from an outer cylinder (23) in which the gas is stored at high pressure at substantially room temperature, shortly after the fuel-free compressed air from the intake and compression chambers (1) enters the separate combustion chamber; the vehicle is also equipped with a self-contained high-pressure compressor (25) which is activated during deceleration and braking to charge the outer main tube (23), characterized in that the high-pressure compressed air of the compressor (25) is diverted and stored to maintain its high temperature and high pressure, said compressed air being injected into the engine combustion or expansion chamber (2) for use once the vehicle has to be restarted or re-accelerated.

2. The method of claim 1, wherein the storage of compressed air is accomplished in a fixed capacity manner.

3. Method according to claim 1, characterized in that the storage of compressed air is effected in a variable capacity manner, so as to obtain and maintain, from the start of the injection of air, an almost constant air pressure and temperature, approximately similar to the pressure and temperature provided by the compressor.

4. A method according to claim 3, characterized in that the control of the increase and change of the stored air volume uses compressed air in the outer main cylinder (23).

5. Method according to one of claims 1 to 4, characterized in that the reacceleration drum is thermally insulated or made of a thermally insulating material to maintain high temperature and high pressure.

6. Device for carrying out the method according to one of claims 1 to 5, characterized in that the storage of the compressed air from the compressor (25) is carried out in a reacceleration cartridge (32,35) located in a branch of the exhaust line (27) of the onboard compressor, between the nozzle (22A) of the combustion or expansion chamber (2) and said exhaust line.

7. The apparatus of claim 6, wherein the reaccelerating drum is a fixed volume drum (32).

8. The device according to claim 6, characterized in that the reaccelerating drum is variable capacity (35).

9. The device according to claim 8, characterized in that the reacceleration cylinder consists of a hollow cylinder (35) of small diameter, concentrically extended by a hollow cylinder (37) of larger diameter, in which a secondary piston (38) slides, said cylinder (35) of small diameter being connected, on the one hand, to the compressed air intake pipe (27) of the self-contained high-pressure compressor (25) through a branch pipe (27A) and, on the other hand, to a reacceleration nozzle (22A); the large diameter cylinder (37) has a medium pressure compressed air intake conduit (40) which compressed air from a main cylinder (23) of very high pressure and expands as it passes through a buffer reservoir (41), and the ratio of the cylinder diameters must be such that the medium pressure in the large diameter cylinder (37) can maintain the high pressure in the small cylinder (35) selected as the reacceleration cylinder for supplying the reacceleration supplement air to the air nozzle (22A).

10. Device according to one of claims 6 to 9, characterized in that the discharge duct (27) of the compressor and the branch duct (27A) to the reacceleration drum are provided with a valve (33) which, on the one hand, allows the discharge duct (27) of the compressor (25) to be closed in the direction of the outer main drum (23) during deceleration and/or braking of the motor vehicle, allowing the air flow from the compressor (25) to flow into the branch duct (27A), and, on the other hand, to close the branch duct (27A) in order to or in order to allow the compressed air flow to the outer main drum (23) to be unimpeded; or when the air in the reacceleration cylinder (35) is full, the self-loading compressor (25) can still be used for decelerating and braking; or when re-accelerating, the compressed air flow is made to flow under the pressure of the re-acceleration barrel (35) intensively towards the re-acceleration nozzle (22A), while the compressor (25) is switched off, in order to avoid pressure losses towards the compressor (25) and/or the outer main barrel (23).