JPS63215808A - Exhaust energy recovering device - Google Patents

Abstract

PURPOSE:To enhance recovering efficiency of exhaust energy in response to the load state of an engine by providing a turbine which is driven in its rotation by exhaust gas of the engine and a turbine which is combined coaxially with this turbine and has a scroll of a small capacity respectively. CONSTITUTION:A super high-speed turbine (d) provided in a housing (c) is connected. To the tip end of an exhaust manifold (b) in an engine (a). And an exhaust turbine blade (e) is installed rotatably in the super high-speed turbine (d). In this case, as for the super high-speed turbine (d), a scroll j1 of a large capacity and a turbine d1, and a scroll j2 of a small capacity and a turbine d2 are provided respectively on the both sides of the rotor of a super high-speed alternator (i) which is put between them, and the super high-speed turbine (d) is formed into a double turbine chamber. And at the time of rotation of the engine (a), changeover to the double turbine chamber is carried out by a controller (f), the super high-speed alternator (i) is driven by either of the turbine d1 of a large capacity or the turbine d2 of a small capacity, and electric power is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust energy recovery device for recovering exhaust energy from an engine.

(Prior art) Gasoline engines and diesel engines, which are internal combustion engines, use the energy generated by burning fuel in a cylinder to push down a piston to generate power, and the exhaust gas generated by combustion in the cylinder is directly exhausted. It is discharged from the manifold towards the outside air. This exhaust gas is hot and pressurized and holds 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.
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. This is an attempt to improve operational efficiency, and I would like 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 and returned to the crankshaft. The structure of the energy recovery device as a whole is complex, and the transmission efficiency is poor, so not only does the overall cost of the internal combustion engine become effective, but the operating efficiency is also not very good, and it cannot be used at partial loads, making it not very effective. It wasn't.

For this reason, Japanese Patent Laid-Open No. 58-214815 (hereinafter referred to as a known example) proposes the following exhaust energy recovery device using an alternating current generator and a direct current generator.

FIG. 4 is a block diagram showing a schematic configuration of a known example.

In the figure, 1 is an adiabatic type engine. As mentioned above, this engine is of a heat-insulating type using ceramics 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.

An exhaust turbine 3 is connected to the tip of the exhaust manifold 2. 3a is a turbine vortex chamber, inside which turbine blades 3b are rotatably arranged. Reference numeral 4 denotes a high-pressure alternating current generator, the rotating shaft of which is directly connected to the turbine shaft 3c of the exhaust turbine 3. The alternator 4 is a two-pole alternator whose rotor is made of a permanent magnet and whose armature winding is arranged on the fixed side. This AC power generation @ 4 is driven by the 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 the centrifugal The 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 use in automobiles, and a frequency of about 3.5 KHz. Further, 5 is a rectifier circuit in which silicon rectifier elements are bridge-coupled, and 8 is a switching regulator, which stabilizes the DC output current of the rectifier circuit 5.
It operates so that the DC generator 7 can be efficiently and stably driven. The rotating shaft of the DC motor 7 has two gears 7a and 7b.
It is connected to the rotating shaft 1a of the engine 1 via.

Next, the operation of the known example will be explained.

As the rotational speed of the engine 1 gradually increases, the output voltage of the alternating current generator 4 also increases, and the direct current motor 7 is finally driven. The DC motor 7 is connected to the rotating shaft 1a of the engine 1.
In order to drive the engine 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.

(Problems to be Solved by the Invention) The exhaust turbine installed in the conventional exhaust energy recovery device as described above does not operate smoothly under, for example, operating conditions where the engine rotates at a constant speed and high load and the amount of exhaust gas is large. Because the engine is designed to operate at low speeds, when the engine is rotating at low speed, there is not enough exhaust gas to drive the exhaust turbine, which prevents the exhaust turbine from rotating smoothly and prevents power generation. The disadvantage is that the machine cannot be driven.

In order to improve these drawbacks, a meter adjustment mechanism was installed in the nozzle to change the speed of the exhaust gas hitting the turbine blades, making it possible to freely respond to the engine from high-load rotation to low-load rotation. There are some, but the structure is complex and not very practical.

Therefore, in an exhaust energy device that uses a turbine generator to recover the energy contained in the exhaust gas of the Kibatsu Ichisen engine, it is possible to accurately generate energy from the exhaust gas from low to high engine speeds with a simple structure. The objective is to provide a new device that can collect

(Means for Solving the Problems) The exhaust energy recovery device of the present invention includes a first turbine rotatably driven by exhaust gas of an engine, and a first turbine coupled coaxially with the first turbine. a second turbine having a scroll with a smaller capacity than that of the turbine; a generator directly connected to the rotating shafts of these turbines and obtained by rotationally driving these turbines; and gas control means for controlling exhaust gas supply.

(Function) The present invention has a double gas turbine chamber arranged at the rear end of the exhaust pipe of the engine, and inside this, a turbine with different sizes of scrolls and blades and an alternating current machine that can rotate at ultra high speed are integrated. A generator configured to open and close two exhaust passages to the turbine chamber depending on the engine load condition. Since a controller is provided that controls the amount of power generated according to the state of charge of the battery to which the generated power is supplied, exhaust energy can be efficiently converted into power. Further, this controller serves both as a voltage converter for converting alternating current voltage into direct current voltage and as an electrical energy distributor, so that power supply to the battery and direct current load can be controlled with high accuracy.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of the present invention, and in FIG. 6, the engine a has a heat-insulating structure using ceramics for the cylinder liner, cylinder head heat insulating plate, exhaust valve, piston, etc., as in the known example, The outer wall of the exhaust manifold b also has a heat insulating structure using ceramics. An ultrahigh-speed turbine d provided within the housing C is connected to the tip of the exhaust machining hold b. Exhaust turbine blades e are rotatably mounted within the ultra-high speed turbine d.

FIG. 2 is an explanatory diagram showing the detailed structure of the ultra-high-speed turbine d of the present invention. As shown in the figure, there are a large-capacity scroll j1 and a large-capacity turbine on both sides of the rotor of the ultra-high-speed AC machine i. d, and small capacity scroll J2. small capacity turbine d
2 is shown to provide a generator with a dual turbine chamber configuration.

Returning to Figure 1 again, the controller f doubles as a voltage converter (converts AC voltage to DC voltage) and an electrical energy distributor, and converts the AC voltage generated by the ultra-high-speed AC machine i into DC voltage. After that, the switching regulator charges the battery g, supplies power to the load, and controls the supply of power from the battery to the load. In addition, switching control of the passage to the dual turbine chamber is performed depending on the load condition of the engine.

Note that the housing that houses the exhaust turbine and the generator is integrally constructed with the exhaust manifold. That is, the exhaust energy recovery device according to the present invention is inseparable from the exhaust manifold b provided in the engine a, and is compact.

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

When engine a starts rotating and high-temperature exhaust gas is discharged from the exhaust manifold to the ultra-high-speed turbine, the controller switches the passage to the dual turbine chamber, and the ultra-high-speed AC machine i is transferred to the large-capacity turbine d1. Alternatively, power generation is started by being driven by either the small capacity turbine d2. At this time, the controller f detects the state of charge of the battery g, adjusts the switching regulator, changes the excitation current, and controls the amount of power generated by the alternator to an appropriate value.

In addition, when the battery switch is turned on, power is supplied from the battery to the load, and the controller converts the AC power generated by the AC machine into DC to charge the battery and increase the amount of power supplied to the load by M! control

FIG. 3 is a flowchart mainly showing the processing procedure for controlling charging of the battery. Next, this flowchart will be explained.

Check the battery specific gravity in S1, the battery temperature in step S2, and measure the battery voltage in step S3.Next, measure the power generation output of the alternator in step S4, and check the switching regulator in step S5. Measure duty. At this time, the voltage of the switching regulator is set, for example, +0.5V higher than the battery voltage.

In step S6, it is checked whether the load power W is greater than 0, and if the determination is NO, that is, if the load has not yet been energized and there is no need to supply power to the load, then the battery charging rate It is checked in step S7 whether VE satisfies a predetermined condition, for example VE<0.75, and the determination is YES.

That is, if rapid charging of the battery is required, the duty of the switching regulator is increased in step 5 to increase the excitation current of the alternator to increase the power generation output of the alternator, and then the battery is charged in step S9. Turn on the charging switch to quickly charge the battery.

In the process of step S6, when it is confirmed that the load power is larger than 0, that is, that the load is energized, the power generation amount and the load power are compared in step SIO, and the power generation amount is higher. If the battery charging rate VE<0.75 is not satisfied in the process of step S7, then in step 311 the battery charging rate ■
It is checked whether E is less than 1.0. When this condition is satisfied, the battery switch is turned off in step SL2, and then the battery charging switch is turned on in step SL5 to perform normal battery charging.

If the amount of power generated per step is smaller than the load power in the process of step SIO, the battery switch is turned on in step S14 to supply power to the load from the battery, and then in step S15 the engine speed is set to a predetermined speed, e.g. 11
If the 0 judgment to check whether the RP is lower than 000RP is YES, the scroll conversion valve is activated in step SXS, and the fuel flow rate is increased in step 817' to increase the engine output, thereby increasing the amount of power generated by the alternator. Next, when it is confirmed in step 517 that the amount of power generation is larger than the load power, the fuel valve is stopped in step 818. Also.

In the process of step 515, the engine speed is 11
If it is confirmed that it is not lower than 000RP, the scroll valve is opened in step 519.

Although not shown, the controller is composed of electronic circuits, etc., and controls the battery charging voltage and the power supplied to the load to a predetermined value, and also opens and closes the passage to the dual turbine chamber depending on the engine load condition. control.

Although one embodiment of the present invention has been described above, the description of the above embodiment is a preferred example of the device of the present invention, and the present invention allows various modifications and applications to be made without departing from the spirit and gist of the present invention. Those skilled in the art will understand that this is possible.

(Effects of the Invention) As described above, the present invention provides a generator integrally comprising a turbine and an alternating current machine capable of rotating at ultra-high speed at the tip of the exhaust manifold of an engine.

Two turbine chambers with different scrolls and blades are installed on both sides of the alternator's rotor, and the amount of power generated is controlled by opening and closing both roads according to the engine load condition. Optimal power can be obtained according to the requirements, and exhaust energy can be efficiently converted into power.

In addition, one generator output is used to charge the battery and supply power to the load using a controller that functions as both a voltage converter and an electrical energy distributor, making the configuration simpler than using a DC motor connected directly to the engine shaft as the load. become.

Furthermore, since the amount of power generation is appropriately controlled according to the state of charge of the battery, exhaust energy can be effectively utilized.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of the present invention, FIG. 2 is a configuration diagram of the main parts,
FIG. 3 is a flowchart, and FIG. 4 is a configuration diagram of a conventional example. a...Engine, b...Manifold, C...Housing, d...Ultra high speed turbine, e...Exhaust turbine blade 1, f...Controller, g...Battery, h...・Load, i...Ultra high speed AC machine. Patent applicant: IsuC Medosha Co., Ltd. Agent: Minoru Tsuji ε Figure 2 Figure 3

Claims (2)

[Claims] (1) A first turbine rotationally driven by engine exhaust gas, a second turbine coupled coaxially with the first turbine and having a scroll having a smaller capacity than the first turbine; It is characterized by having a generator that is directly connected to the turbine rotating shaft and obtained by rotationally driving these turbines, and a gas control means that controls the exhaust gas supply to the first and second turbines according to the flow rate of the exhaust gas, respectively. Exhaust energy recovery device. (2) The exhaust energy recovery device according to claim (1), wherein a turbine and a generator are integrated into a part of the exhaust pipe of the engine.