JPS58214615A - Device for recovering exhaust energy of engine - Google Patents

Abstract

PURPOSE:To enable exhaust energy to be recovered even in low enthalpy at the partial output of an AC generator by giving electic energy generated from the AC generator to a DC motor to drive the DC motor and feed back the output of the AC generator to the output shaft of an engine. CONSTITUTION:When an engine 1 starts its rotation and high temperature exhaust gas is exhausted from an exhaust turbine 3, a turbine blade 3b of the exhaust turbine 3 begines its rotation to drive an AC generator 4 for generation. When the rotational frequency of the engine 1 is raised gradually to increase an amount of exhaust gas and raise the temperature of same, the output voltage of the AC generator 4 is also raised to drive finally a DC motor 7. And since the DC motor 7 drives the rotary shaft 1a of the engine 1 in the direction of increasing its output, energy which the exhaust gas has been recovered and fed back to the rotary shaft of the engine 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exhaust energy recovery device for an engine.

Gasoline engines and diesel engines, which are internal combustion engines, use the energy generated by burning fuel in the cylinder to push down the piston to generate output, and the exhaust gas generated by combustion in the cylinder is directly released from the Sugi 1 air manifold to outside air. ejected in the direction. This exhaust gas is high temperature and high pressure, and still retains a considerable amount of energy.

By the way, recently various parts of internal combustion engines such as the outer wall of the exhaust manifold, cylinder liner, cylinder head insulation board, etc.
Adiabatic internal combustion engines have been developed that use ceramics for exhaust valves, pistons, etc. This internal combustion engine does not cool the internal combustion engine by dissipating the heat generated inside it, as in the past, but instead extracts hotter exhaust gas and returns this energy to the crankshaft. A conventional method that aims to improve operating efficiency is to place a turbine rotated by exhaust gas near the exhaust port, and use the surplus rotation obtained from this turbine. This device decelerates the power by speed conversion using multi-stage gears and returns it to the crankshaft. However, in such a device, the structure of the entire energy recovery device is complex and the transmission efficiency is poor, so the (+/ Not only did it make the J-stage expensive, but its operating efficiency was not very good, and it also had the disadvantage that it could not be used under partial load, so it was not very effective.

The present invention aims to improve these conventional drawbacks, and efficiently recovers the energy lost in the Lln (11J, stored in the exhaust gas of an internal combustion engine) and efficiently returns it to the crankshaft. If,! It is about providing.

Next, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram of the present invention, and 1 in the figure is an adiabatic type engine. As mentioned above, this engine has a cylinder head (-J--, cylinder head insulation 4j7, JJ
Most importantly, it is an insulated type that uses ceramics such as pinutons. 2 is tJl ki and 2 hold,
The outer wall is made of ceramic material and has an insulating structure. 1) A 1-air turbine 3 is connected to the tip of the 4-Jl air manifold 2. Reference numeral 3a denotes a turbine vortex chamber, in which a turbine blade 3b is rotatably disposed. Reference numeral 4 denotes a high-pressure alternating current generator, and its rotating shaft is directly connected to the turbine shaft 3C of the exhaust turbine 3. The alternator 4 has a rotor made of a permanent magnet, and a '71 magnet on the fixed side.
f, a two-pole alternating current generator with a machine winding. This AC Mt generator 4 is driven by the exhaust turbine 3 at a maximum rotation speed of about 100,000 times per minute, so the rotor is thin and long in the direction of the rotation axis, and the Centrifugal force is minimized to prevent rotor damage. Further, since the alternating current generator 4 rotates at a high speed, it generates an alternating current voltage of about 200 V, which is a high voltage for automobiles, and a frequency of about 3.5 KHz. Reference numeral 5 denotes a converter composed of a thyristor bridge, which converts the alternating current generated by the alternator 4 into direct current (pulsating current). The cylisk that makes up this controller is a high-frequency cylisk that operates satisfactorily even at a frequency of about 3.5 KHz. Reference numeral 6 denotes a gate control circuit for controlling the thyristor gate of the converter 5. Reference numeral 7 denotes a DC motor, the rotating shaft of which is connected to the rotating shaft 1a of the engine 1 via two gears 7a and 7b. This DC motor 7 is preferably a direct-wound motor that operates at approximately the same number of rotations as the engine l. Reference numeral 8 denotes a current detector that detects 111 the drive current of the DC motor 7.

Next, the operation of the present invention will be explained.

When the engine 1 starts rotating and a high-quality JJI gas is discharged from the 1-node air turbine 3, the turbine blades 3b of the tJI air turbine 3 start rotating, and the alternator 4 is driven. Start generating electricity. Initially, the gate control circuit 6 widens the gate of the cyrisk that constitutes the converter 5, and converts the electric power generated by the alternator 4 into 7 tons of DC! ;
An attempt is made to supply it to the motor 7 to drive it, but since the rotational speed of the JJI air turbine 3 is low, the output voltage of the alternator 4 is also small, and the DC motor 7 cannot be driven.

On the other hand, the DC 11r and the motor 7 are rotated by the engine 1 and become a generator Ilf to generate DC voltage, but the gate control circuit 6 gate-controls the converter 5 to the "DC motor 7 powering" state. , the electric power generated by the DC motor 7 does not flow backward.

As the rotational speed of the engine 1 gradually increases and the amount of gas increases and its temperature also rises, the output voltage of the alternating current generator 4 also rises and finally comes to drive the DC motor 7. Since the DC motor 7 drives the rotating shaft 1a of the engine 1 in a direction that increases its output, the energy contained in the exhaust gas is recovered and fed back to the rotating shaft of the engine 1. Even if the engine speed changes, the gate control circuit 6 controls the thyristor gate so that the DC motor 7 can always be driven under appropriate load conditions.
If an excessive load is applied to the DC motor 7 for some reason and a current exceeding the rating begins to flow, this is detected by the current detector 8.
is detected, and the gate control circuit 6 narrows down the gate of the thyristor of the converter 5 to suppress the current and control the DC motor 7 so that it can always be driven under the optimum load condition.

With this kind of circuit configuration, the entire circuit can be configured with a high-voltage circuit system, so it is possible to configure the entire circuit with a high-voltage circuit system.
Loss is also reduced compared to a 2V or 24V system circuit configuration.

FIG. 2 is a 41-composition drawing showing an example of fp, ゛, and the present invention, in which l; l: il- is omitted in the same part as the il drawing, and the explanation thereof will be omitted.

In FIG. 2, 15 is a rectifier circuit in which silicon rectifier elements are bridge-coupled. 18 is a switching regulator, which is a DC output type l/l of the rectifier Q circuit 15.
, is stabilized in 1111, and the motor 7 is moved 1'1 so that it can be driven efficiently and stably.

In the operation of this embodiment, the alternating current generated by the alternator 4 is directly rectified by the rectifier circuit 15. Since the voltage of the output of the rectifier circuit 15 fluctuates rapidly, the switching 1/G]
/-After being manually powered on evening 18 and stabilized, the DC motor 7
is applied to

As a modification of this embodiment, the output terminal of the alternator 4 may be
(In addition to setting up the J'E device 1 for pressure,
A rectifier circuit 15 and a regulator 18 are arranged near the DC motor 7, and an AC generator ↑11: 4? J4 output voltage A
After further applying y1 pressure due to pressure loading property, this is 't'+B
) The voltage may be rectified by the It circuit 15, converted to an optimum voltage for the DC motor by the regulator 18, and then the DC motor 7 may be driven.

As described in detail in 4-4 above, the present invention directly connects the rotating shaft of an alternator to the turbine shaft of an exhaust turbine disposed at the tip of an exhaust manifold of an engine, and also connects the rotating shaft of a DC motor to the rotating shaft of the engine. The electric energy generated from the AC generator is coupled to the DC motor to drive it, and the output of the AC motor is fed back to the output shaft of the engine, so it can be operated under full load conditions like conventional equipment. Unlike the exhaust energy that can only be recovered and returned to the engine, it can be easily recovered even when the enthalpy of the exhaust energy is low at partial engine output. In addition, in the conventional mechanical system, υ1−
Frictional loss is smaller than that of energy recovery methods, and electrical circuit resistance loss can be reduced by increasing the circuit voltage, which dramatically improves engine combustion efficiency compared to conventional methods. be able to.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 is a small block diagram showing another embodiment. 1. Φ engine 2. JJI manifold 3.
・4Jl air turbine 4・・AC generator 5・・Converter 6・Gate control circuit 7・・DC motor 8・
・Current detector 4) Fraudulent applicant: Representative of Isugu Jidosha Co., Ltd. Patent attorney Minoru Tsuji (1 other person)

Claims (1)

[Claims] In an engine that suppresses the radiation of heat generated internally and is equipped with an exhaust turbine, the rotating shaft of an alternator is directly connected to the turbine shaft of the exhaust turbine, and the rotating shaft of a DC motor is coupled to the rotating shaft of the engine. An exhaust energy recovery device for an engine, characterized in that electric energy generated from an alternating current generator is applied to a direct current motor to drive it, and the output of the alternating current motor is returned to the output shaft of the engine.