JPS59141712A - Engine equipped with exhaust energy recovering device - Google Patents

Abstract

PURPOSE:To make available the efficient recovery of exhaust energy, by directly coupling a generator with a first exhaust turbine recovering the exhaust energy and an intake compressor with a second exhaust turbine recovering the remaining exhaust energy. CONSTITUTION:The top end of exhaust manifold 2 of an engine 1 is provided with a first exhaust turbine 3 which has an alternating current generator directly coupled with the turbine shaft 3c thereof, in order that a power may be supplied to an induction electric motor 7 directly coupled with the rotatable shaft 1a of engine via a converter 5, a DC-DC converter 9, an inverter 6 and a phase advancing condenser 8 for thereby recovering an exhaust energy. A second exhaust turbine 14 having an intake compressor 15 directly coupled therewith is provided at the downstream of first exhaust turbine 3 in order to utilize the remaining exhaust energy in a supercharging operation. A main valve 20 closes and a bypass valve 23 opens during a high load and low speed operation, so that a supercharging effect may be improved.

Description

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

Gasoline engines and diesel engines, which are inner reef 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 directed to the outside air from the exhaust manifold. is discharged. 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 plate, etc.
A thermally insulated internal combustion engine using ceramics for exhaust valves, pistons, etc. has been developed. This internal combustion engine does not cool the internal combustion engine by dissipating the heat generated inside it, as in the past, but extracts hotter exhaust gas and recovers this energy to operate the engine. This is an attempt to increase efficiency. To explain what has been done in the past, a turbine rotated by exhaust gas is placed near the exhaust port, and the surplus rotational power obtained from this turbine is reduced by speed conversion using multi-stage gears. The energy recovery device is used to return energy to the crankshaft, but the overall structure of the energy recovery device is complex and the transmission and speed efficiency is poor. is also not very good, and has the disadvantage that it cannot be used under partial load.
It wasn't very effective. In addition, instead of the adiabatic engine as described above, in a normal engine equipped with a cooling device, a turbine rotated by exhaust gas is placed near the exhaust port, and this turbine rotates an air compressor, causing the engine to operate at high speed. Some systems attempted to improve engine operating efficiency by forcefully feeding combustion air, which tends to be insufficient during high rotational loads, to the intake manifold. Therefore, depending on the turbine, it is not possible to generate effective compressed air when the flow velocity of exhaust gas is low, and the air that is insufficient when the engine rotates at low speed and under high load is effectively sent to the engine. Therefore, it is not possible to improve the operating efficiency of the engine at low speeds and high loads. In addition, with this device, when the engine rotates at high speed, supplying all of the compressed air generated by the turbine to the engine would result in an excessive supply amount, so some of the exhaust gas is bypassed and released directly into the atmosphere. Furthermore, all the exhaust energy during low-speed rotation is released directly into the atmosphere.
These energies could not be used effectively.

The present invention aims to improve these conventional drawbacks, and its purpose is to efficiently recover the energy held in the exhaust gas in an adiabatic engine, thereby increasing the engine operating efficiency and supercharging the engine. An object of the present invention is to provide an engine with an exhaust energy recovery device that can be operated effectively.

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

The figure is a block diagram of the present invention, and numeral 1 in the figure is an adiabatic type engine. As mentioned above, this engine is a heat-insulating type that uses Ceraminx for the cylinder liner, cylinder head insulation plate, exhaust valve, piston, etc. 2 is an exhaust manifold whose outer wall is made of ceramics and has a heat insulating structure. A first exhaust turbine 3 is connected to the tip of the exhaust manifold 2 . Since high-temperature Φ high-speed exhaust gas directly passes through the first exhaust turbine 3 from the exhaust manifold 2, the exhaust turbine 3 is a so-called high-speed turbine that generates effective output at high speed rotation. Reference numeral 3a denotes a turbine vortex chamber, in which a turbine blade 3b is rotatably disposed. 4 is a high-pressure alternator, whose rotating shaft is connected to the exhaust turbine 3.
It is directly connected to the turbine shaft 3C. The alternator 4 is a two-pole alternator whose rotor is composed of a permanent magnet and has an armature winding on the fixed side. This alternator 4 is driven by the first exhaust turbine 3 at a maximum rotation speed of about 10,000 times per minute, so the rotor is thin and long in the direction of the rotation axis, and rotates at high speed. The resulting centrifugal force is minimized to prevent rotor damage. In addition, since this alternator 4 rotates at high speed, it is suitable for use in automobiles at a high voltage of about 200 V and a frequency of 3.5 K.
Generates an alternating current voltage of about Hz. A converter 5 is composed of a thyristor bridge, and converts the alternating current generated by the alternating current generator 4 into direct current (for descaling).

The thyristor that makes up this converter is 3φ5 KH
This is a high frequency thyristor that operates satisfactorily even at frequencies around Z. 6 is an inverter, which converts the DC converted by the converter 5 into AC. Note that the inverter 6 outputs an alternating current at a frequency commanded by a command even number vC sent from a control device 21 to be described later, and the frequency depends on the rotation speed of the engine l and is approximately 10 Hz.
to several hundred Hz. 7 is an induction motor,
The rotating shaft is connected to the engine 1 through two gears 7a and 7b.
It is connected to the output shaft 1a of. 8 is a phase advance capacitor. 9 is a control signal C sent from the control device 21
A switching circuit controlled on/off by 8, lO
is a high voltage type battery.

A second exhaust turbine 14 is connected to the outlet of the first exhaust turbine 3 to recover residual exhaust gas energy. This second exhaust turbine 14 is of the so-called low-speed type, which has the characteristic of producing the most effective compressed air at relatively low air flow velocities. Reference numeral 14a denotes a turbine vortex chamber, in which a turbine blade 14b is rotatably disposed. Reference numeral 15 designates an intake compressor, and its rotating shaft is directly connected to the turbine shaft 14c of the second exhaust turbine 14. Compressed air compressed by the intake compressor 15 is sent under pressure to the intake manifold 17 through the introduction pipe 16. 22 is an exhaust bypass circuit, which directs the exhaust gas from the exhaust manifold 2 to the second exhaust turbine 14.
It is set up for sending to. 20 is the main valve, 2
3 is a bypass valve, and each valve is provided with actuators 24 and 25 for opening and closing the valve. Reference numeral 18 denotes a rotation speed detector having a structure such that, for example, the number of teeth of the gear 7b is counted by a peak-up coil. Reference numeral 19 denotes a load detector that detects the load on the engine 1 from the rack position, the amount of accelerator depression, and the like. 21 is a control device that determines the amount of exhaust gas to be sent to the first JJE turbine 3 and the BL of exhaust gas to be sent directly to the exhaust turbines 12 from the data of the rotation speed detector 18 and the load detector 19; +132. L, the main valve 20. which sends No. 44 to the 7 cutout units 24 and 25. This controls the opening degree of the bypass valve 23. The control device 21 also sends a command signal V to operate the inverter 6 in the power or regenerative state while monitoring the outputs of the current detectors 26 and 27.
C, and also outputs a control signal C8 for controlling the switching circuit 9 on-off. 28 is an air pressure sensor.

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

First, when starting the engine 1, the main valve 20 is fully opened, the bypass valve 23 is fully opened, and all exhaust gas discharged from the engine 1 is allowed to flow into the exhaust turbine 3.

When the engine l starts rotating and high-temperature Φ high-pressure exhaust gas is fed into the first exhaust turbine 3, the turbine blades 3b of the first exhaust turbine 3 start rotating, and the alternator 4 is driven. , starts generating electricity. The high frequency AC power generated by the AC generator 4 is once transferred to the converter 5.
This DC power is converted into a low frequency AC power that drives an induction motor 7 by an inverter 6.
An attempt is made to drive this, but since the rotation speed of the first exhaust turbine 3 is low, the output power of the alternator 4 is also small.
The induction motor 7 cannot be driven.

As the rotation speed of the engine 1 gradually increases, the pressure of the exhaust gas also increases, and its temperature also increases, the output power of the alternator 4 also increases. 'When the output power of the inverter 6 becomes larger than the back electromotive force of the induction motor 7, the inverter 6
becomes a power running state and starts to drive the induction motor 7.

Since the induction motor 7 drives the output 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 output shaft 1a of the engine 1.

In the present invention, when the engine 1 is in a partial load state, the first
A considerable amount of energy remains in the exhaust gas that has driven the exhaust turbine 3. Therefore, the remaining exhaust energy that could not be recovered by the first exhaust turbine 3 passes through the second exhaust turbine 14, and the turbine blades 14b of the second exhaust turbine 14 start rotating due to this exhaust energy. As a result, the intake combiner 15 connected to the turbine blade 14b is driven, and the compressed air is sent under pressure to the intake manifold 17 through the introduction pipe 16. However, the amount of air is not large. When the vehicle is running at high speed, the rotational speed of the engine 1 increases, and when the vehicle is operated under full load, the exhaust gas also becomes high temperature and high pressure, so it passes through the first exhaust turbine 3. , the energy of the exhaust gas reaching the second exhaust turbine 14 increases, and the air pressure sent to the intake manifold 17 also increases by -1; approaching the intercept point. The control device 21 detects this based on the signal from the air pressure sensor 238, and gives a command signal VC to the inverter 6 to bring the inner groove motor 7 into the maximum power state, maximizing the return of energy to the engine 1. The load on the exhaust turbine 3 of No. 1 is increased. Therefore, the rotational speed of the second exhaust turbine 14 also decreases, and the pressure within the intake manifold 17 does not exceed the intercept point. Note that if the load on the engine 1 further increases and the air pressure in the intake manifold 17 is about to rise further, the switching circuit 9 is turned on and energy is stored in the battery 10 as well. The load also increases, the rotational speed of the second exhaust turbine 14 decreases, and the pressure in the intake manifold 17 decreases.

It is generally known that when the engine 1 is rotating at low speed and under high load, that is, when climbing a slope in a low gear, the amount of air taken in from the intake manifold 17 tends to be less than the ideal amount. However, in this case, the main/< valve 20 restricts the supply of exhaust gas to the first exhaust turbine 3, and the bypass valve 2
3, exhaust gas is directly supplied to the second exhaust turbine 14, and compressed air optimal for combustion is force-fed to the intake manifold 17. Since the second exhaust turbine 14 is of a low speed type, it can send effective compressed air to the engine 1.

The opening and closing of the main valve 20 and the bypass valve 23 are adjusted by a control device 21. That is, the data from the speed detector 18 and the load detector 19 are read into the control device 21, and the control device 21 calculates the opening degrees of the main/<lube 20 and bypass valve 23 that are optimal for the speed and load at that time, and then controls them. A signal is sent to both actuators 24,25.

As explained in detail above, unlike conventional devices that can only pump compressed air when the engine is running at high speeds and under high load, the present invention provides compressed air to the engine even when the engine is running at low speeds and under high loads. Air can be pumped under pressure, and not only at high speeds and high loads, but also when there is little need to pump compressed air to the engine, such as when the engine is operating at medium speeds and medium loads, or when medium speed φ is low load. ,
The exhaust energy at that time can be effectively recovered to the output shaft of the engine. In addition, the structure that recovers exhaust energy on the engine's output shaft has lower friction loss than conventional mechanical systems that recover exhaust energy, and reduces electrical circuit resistance loss by increasing circuit voltage. 1. Because it can be forced. The combustion efficiency of the engine can be dramatically improved compared to conventional ones, and the structure of the entire energy recovery device can be made extremely simple.

[Brief explanation of the drawing]

The figure is a configuration diagram showing an embodiment of the present invention. 1. φ Engine la. Output shaft 2Φ. 2 holds with exhaust 3. Exhaust turbine 3 a. Turbine vortex chamber 3 b. Turbine blade 30. Turbine shaft 4. AC generator 5. Converter 6. Inverter 7. Induction Motor 7a, gear 7b, gear 8Φ, phase advance capacitor 9φ, DC
-DC converter 10, battery 14, exhaust turbine 14a, turbine vortex chamber 14b, turbine blade 14cm, turbine shaft 15, intake compressor 16, introduction pipe 17, intake manifold 18, rotation speed detector 19, load detector 20, main valve 2
1.Control device 22.Exhaust bypass circuit 23.Bypass valve 24-7 Cutuator 25.Actuator Patent applicant: Isugu Jidosha Co., Ltd. Patent attorney: Minoru Tsuji (1 other person)

Claims (2)

[Claims] (1) In an engine that suppresses radiation of heat generated inside the engine and operates an exhaust turbine using exhaust gas energy, a first exhaust turbine that recovers exhaust gas energy is provided in the exhaust circuit, The first
A second exhaust turbine is provided downstream of the exhaust turbine to recover the remaining exhaust energy, and the rotating shaft of the generator is directly connected to the turbine shaft of the first exhaust turbine, and the rotating shaft of the electric motor is connected to the output shaft of the engine. Connecting the shafts, applying electric energy generated from the generator to the electric motor to drive it, returning the output of the electric motor to the output shaft of the engine, and driving the intake compressor with the second exhaust turbine. An engine equipped with an exhaust energy recovery device. (2) In an engine that suppresses the radiation of heat generated inside the engine and uses exhaust gas energy to operate an exhaust turbine, the first and second Exhaust turbines are provided in series, an exhaust bypass circuit is provided that bypasses the first exhaust turbine, and a rotating shaft of a generator is directly connected to the turbine shaft of the first exhaust turbine, and an electric motor is connected to the output shaft of the engine. The rotating and rotating shafts are connected, and the electric energy generated from the generator is applied to the electric motor to drive it, and the output of the electric motor is returned to the output shaft of the engine, and the second exhaust turbine is used to create an intake compressor. An engine equipped with an exhaust energy recovery device, characterized in that the engine is operated in an optimal state by driving a first exhaust turbine and controlling the amount of exhaust gas passing through each of a first exhaust turbine and an exhaust bypass circuit.