GB2062112A

GB2062112A - Device for Utilization of Residual Energy in Machinery

Info

Publication number: GB2062112A
Application number: GB8033149A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-10-17
Filing date: 1980-10-14
Publication date: 1981-05-20
Also published as: FR2467989A1; DE2941902C2; DE2941902A1; JPS5660876A; FR2467989B1

Abstract

An I.C. engine (B) drives an exhaust gas turbine (T) which drives a flywheel (S) through a clutch (K1). The flywheel stores energy and can when required drive an energy consuming machine (X) e.g. an air compressor, by way of a clutch (K2). Alternatively, an electric vehicle with regenerative braking has a further motor, separate from the traction motor, which drives a flywheel. The flywheel can be connected through a clutch to an electrical generator which then supplies electrical power to the traction motor or to ancilliaries. <IMAGE>

Description

SPECIFICATION Device for Utilization of Residual Energy in Machinery This invention relates to a device for using the residual energy in machinery, for example the energy contained in exhaust gases of internal combustion engines.

The consumption of energy is an important matter in all fields of technology. The desire to keep the consumption of energy as low as possible is predominant but considerable importance is also attached to the recovery of excess energy or residual energy from any technical processes or operation, e.g. utilization of the exhaust heat in a generating plant.

The utilization of hot exhaust gases from an internal combustion engine has become of practical importance. It is known to use the hot exhaust gases to drive a turbine which in turn drives a charging compressor for the internal combustion engine and thereby increases its output. These turbochargers, however, are only effective when the residual energy in the exhaust gases is sufficiently high, i.e. when the engine is rotating at a relatively high speed. It must be regarded as a disadvantage that at lower speeds such as those prevailing when the engine is starting, the increase in power given by a turbocharger is not available.

German Specification No. 28 08 147 discloses an arrangement which deals with this problem. In order to supply an internal combustion engine with sufficient scavenging and charging air even when the energy from the exhaust gas turbine is no longer sufficient for this purpose, the turbocharger in this arrangement is structurally combined with an electric motor which supplies the missing energy to it. Although this arrangement provides some improvement in the balance of supply and demand of energy for the engine, it requires the use of an external source of energy for driving the electric motor, e.g. a battery.

Another method of converting the kinetic energy of a moving body into useful energy is disclosed in German Specification No. 1451 916, which proceeds from the fact that when a moving body, i.e. a vehicle, is braked or stopped, its energy of movement is used to compress a working medium stored in a pressure tank. The medium in the tank may then be used to assist the combustion engine of the vehicle for a short time. Although precompressed charging air is supplied to the engine in this arrangement, the method requires an elaborate arrangement of compressors, pressure tanks, pipes and seals. The residual energy contained in the exhaust gases is not utilized.

Another method of recovering energy is known from electric regenerative braking, where the kinetic energy of the vehicle released when the brakes are applied is used to generate electrical energy which is fed back into the supply line, or otherwise utilized. In this arrangement again the recovery of energy depends on the velocity or speed of rotation at the time.

It is an object of this invention to provide an arrangement for utilization of the residual energy in machinery, in particular the residual energy contained in exhaust gases of an internal combustion engine, which enables the energy to be utilized not only at high speeds but under other conditions and, if desired, with some time delay.

According to this invention there is provided a device for utilization of residual energy in machinery, for example the energy in the exhaust gases of an internal combustion engine, wherein a flywheel, connectible to the machine, stores the residual energy, the device having connecting means for connection of an energy consuming machine to the flywheel when required.

The invention is versatile in its applicability and capable of variation both as regards the method of driving the flywheel and as regards the utilization of the energy from the flywheel. The flywheel is driven by, for example, an exhaust gas turbine using the exhaust gases of an internal combusion engine, and it stores energy. The energy stored in the flywheel may be transmitted as and when desired to any type of energy consuming machine, e.g. a compressor.

This arrangement differs from the known exhaust gas turbochargers in that the energy can be taken from the flywheel even when the vehicle is at a standstill or the engine is rotating at low speed, and increased power can be obtained for starting or acceleration by supercharging the engine by way of the compressor.

An advantage of the invention is that interim storage of the available residual energy in a flywheel is possible. As compared with the storage of energy in a pressure tank mentioned above, the invention provides the advantage that the energy stored in the flywheel need not necessarily be used to drive a charging compressor but may be used in some other manner, for example by connecting the flywheel to an electric generator from which the energy is further used, for example for starting or accelerating an electrically driven vehicle. The energy of the flywheel may also be used mechanically for operating for example a starter.

In a vehicle having electrical regenerative braking, the electric energy obtained may be supplied to an electric motor which drives the flywheel. In all cases, use of a flywheel and storage of the kinetic energy of the flywheel affords advantages for further use of the energy since storage enables the energy to be obtained at some later time and under a wide variety of operating conditions of the original machinery.

Embodiments of the invention will now be described by way of example, with reference to the drawing, in which: Figure 1 is a schematic representation of residual energy storage in a flywheel driven by an exhaust gas turbine; and Figure 2 is a schematic representation of an embodiment with an electrically driven flywheel.

Referring to Figure 1, a primary machine is an internal combustion engine B. Exhaust gases A from the engine B are carried in the direction of the arrow to an exhaust gas turbine T whence they escape into the atmosphere, as indicated.

The turbine T drives a flywheel S by means, not shown, either directly or by way of a transmission.

The bearings at each side of the flywheel S, and clutches K1 and K2 at the driving and driven ends of the flywheel, indicate that, after having stored the energy, the flywheel can continue to rotate independently of the drive from the engine B. The residual energy in the exhaust gases A is thus stored in the flywheel even when the speed of the engine B is reduced or it is brought to a standstill so that no drive is obtained from the turbine T. At the driven end of the flywheel S, an energy consuming or working machine X, e.g. an air compressor, may be connected beyond the clutch K2.The use of a flywheel S as an energy storing device enables the stored energy to be taken at a later time and independently of the instantaneous condition of the primary engine B and hence also independently of the operating condition of the turbine, and used for whatever purpose it may be required. The supply of energy from the flywheel may therefore be used to operate a charging compressor even under conditions which are such that the known turbochargers are only capable of very limited operation, if any. A brief increase in the power of the machine can therefore also be obtained as an aid for starting or accelerating a vehicle.

The concept of using residual energy need not be limited to exhaust gases of an internal combustion engine but is quite generally applicable to machines which are capable while in operation of supplying part of their unused kinetic energy to the flywheel S which acts as an energy storage device.

Figure 2 illustrates an embodiment which again is assumed to comprise a vehicle drive F with electric regenerative braking N. The electric energy produced by this braking is transmitted to an electric motor M along a path 3, which may include a switch (as shown) so that the flywheel S may be driven by the motor. The device shown by way of example at the driven end of the flywheel is an electric generator E from which the energy can be transmitted along a path 4 to drive an energy consuming machine. Another possibility of utilizing the energy is indicated by the path 5 along which the electric energy from the generator E can be used directly to assist the vehicle drive F for starting or acceleration.

In either case, considerable quantities of energy can be transmitted over a short period, from the flywheel to the attached energy consuming machine, and the advantage of intermittent storage of residual energy is preserved. Short distance transport means such as train or bus should be mentioned as a particularly advantageous field of application. The brief intermittent storage and re-use of the residual energy provides considerable advantages for the frequent braking, stopping, starting and acceleration required for these modes of transport.

Claims

1. Device for utilization of residual energy in machinery, for example the energy in the exhaust gases of an internal combustion engine, wherein a flywheel, connectible to the machine, stores the residual energy, the device having connection means for connection of an energy consuming machine to the flywheel when required.

2. Device according to claim 1, wherein the flywheel is driven by an exhaust gas turbine.

3. Device according to claim 1 for a vehicle having electric regenerative braking, wherein an electric motor is supplied with electric energy derived from the braking and drives the flywheel.

4. Device according to any preceding claim wherein the attached energy consuming machine is a compressor for an internal combustion engine.

5. Device according to any of claims 1 to 3, wherein the attached energy consuming machine is an electric generator.

6. Device according to any preceding claim having selectively operated clutches and/or transmissions at the driving and/or driven side of the flywheel.

7. Device for utilization of residual energy in machinery, the device being constructed and arranged substantially as herein described and shown in the drawing.