JPS5820911A - Compound engine system - Google Patents

Abstract

PURPOSE:To improve a fuel consumption for travelling on an urban street, by providing a vapor accumulator on a vapor inlet part of an expander, in a compound engine having a Rankine engine which is operated by waste heat of a main engine. CONSTITUTION:A Rankine engine is constituted with a vpaorizer 3, an expander 4, a condenser 5 and a feed liquid pump 6. A vapor accumulator 12 is provided on a vapor inlet part of the expander 4. A main engine 1 is suspended at the time of an idling operation, and restarting is carried out by the Rankine engine based on a vapor state inside the vapor accumulator 12. A fuel consumption can be improved like this, in travelling on a street where many idling operations are made. An idling noise of a vehicle at its standing can be reduced and further the smooth restarting becomes possible as this system is so constituted that the main engine is suspended at the time of the idling operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified jLK of a composite engine system having a Rankine engine operated by exhaust heat of a main engine such as an internal combustion engine.

A conventional composite engine system of this type is shown in FIG. (For example, JP 1851-12
4748 Publication).

That is, a steam generator 3. which is a type of heat exchanger provided in the exhaust pipe 1 of the main engine 1. An expander 4 that extracts power from the steam via the steam generator 3. The Rankine engine is mainly composed of a condenser i for condensing low-pressure steam discharged from the expander 4, a liquid supply pump 6 for supplying the condensed working fluid to the steam generator 3, and the like.

T is a power transmission device such as a gear or a fluid coupling, which transmits the power generated in the expander 4 to the main engine 1 to rotate the main engine 1v, thereby improving the fuel efficiency of the main engine 1. Furthermore, the Rankine engine can be used as a compressor for air pumps if necessary.

It is designed to drive a generator and further improve the fuel efficiency of the engine system. In this case, the power is taken out from the Rankine engine only while the main engine 10 is operating. Note that 1 is an oxidation catalyst for exhaust gas purification, and 11 is an exhaust bypass pulp that bypasses -mV steam generation II3 of the exhaust when the exhaust flow rate is large -1.

In a conventional combined engine system such as C, there are a steam generator aS, an expander 4. The Rankine engine was composed of the capacitor S, the liquid supply pump 6, etc., and the power was dissipated from the Rankine engine only when the main engine 1 was in operation. In the city driving mode where there is a lot of ring driving, the power recovery rate during the driving is unavoidable, even though the fuel consumed in the ring driving is 1 s to 25 - of the total fuel. , the exhaust heat causes the Rankine engine Vv to work; however, the overall fuel efficiency improvement rate in the driving mode is 10 to 1.
The problem was that it was only 5%, and a significant change in carbon dioxide could not be expected.

This invention was made by focusing on such conventional problems, and includes a steam 7 cumulator installed at the steam inlet of the expander end of the Rankine engine, and the main engine Vv is stopped during idling operation. ! The purpose of the present invention is to solve the above-mentioned problems by controlling the start-up based on the steam condition in the steam accumulator, and if possible, by controlling the Rankine engine only.

The following description will be made based on this at' drawing.

*Figure g is a diagram showing an embodiment of the present invention.

In the second Ii, the same components as those in the first II are denoted by the same reference numerals, and the explanation thereof will be omitted. 11 is the expander 4
This steam accumulator 120 is provided with a steam population m, and the main body of the steam accumulator 120 is covered with heat insulation #1s. Additionally, a steam pulp 14 is provided between the steam 7 chemulator 12 and the expander 4. Further, the steam accumulator 12 is provided with a temperature sensor 1s and a pressure sensor 16 for detecting the temperature and pressure of steam.

31Il is a diagram showing an example of the control circuit in FIG. 1;
A comparator $1. compares the vehicle speed V at that time with the set vehicle speed Vrd v and outputs a t output if the vehicle speed V is less than or equal to the set single series V,, f. The output of this ratio $1131 and the accelerator switch 8. Steam temperature in the input bit gate 3LIli7 is compared with the set value Trd of the input bit gate 3LIli7 which outputs an output according to the signal of
2 vessels 33. Similarly, the ratio I2 device S4 outputs an output when the steam pressure P is equal to or higher than the set value Pr*f. Comparison of both 11$8.3
It is composed of an AND circuit Ss to which the output of 4 is added, ANDaS*S to which the output of inhibit Y gate $2 and MUNDIIIS is added, and an AND circuit 31 to which the signal of the accelerator switch S and the output of ANDIIISI are added. be done. Note that the s amount is an ignition switch, which is turned off when the output from the AND circuit 36 is applied. Steam pulp 14) iDi1
When the output is added from ml$7, it becomes an opening.

Next, refer to the 5th WAW showing the operation of the embodiment shown in the 11th IIK.

Either the steam temperature or the steam pressure in the steam generator 12 is low, and each set value Trott is Pyd.
If the K command is not reached, the output of the expander 4t'16 is also 10', so the ignition switch 8i of the main engine 1 will not turn OFF (here, in the case of a gasoline engine), so ignition will continue and the main engine 1 will Continue driving without stopping.

When both the steam temperature T and the steam pressure P in the steam 7 cumulator 12 exceed the set values Trd and Pr5f, respectively, the output cover 11' of the ANDB circuit 3Is occurs.

This case will be explained below. At this time, during normal driving, the vehicle speed V is the set vehicle speed Vt@ts, for example, 4 km.
greater than /h or accelerator pedal vIII
32f) The output is 10.
1, the output of M'NDIIIINS6 is 10', and the ignition switch S1 of earthwork engine V1 is set to 0.
It will not become FF. However, when the vehicle is about to stop, that is, when the vehicle is decelerating,
Also, when the vehicle speed ■ becomes less than the set value vr, f, comparison 111
The output from 1 is applied to one input terminal of inhibit gate $2, and since the accelerator switch 8a is off, the output force of inhibit gate 32 becomes I', so the output of ANDlim path $6 becomes 111. The event switch 8.4 of the main engine 1 is turned OFF, and the main engine 1 is stopped.

When the main engine 1 is restarted, the accelerator pedal via megge accelerator switch S is turned ON, and the AND times 11$2
The output of the AND circuit 3T becomes 101 and the OFF switch S1 is turned off via the AND circuit 36 to start ignition, while the output of the AND circuit 3T becomes 111 and the steam pulp 14 is opened to start the Rankine engine. It starts and the main engine is turned on by the power transmission device T? The main engine 11' is started and detonated to drive the vehicle.

Since the expander 4 is activated only by supplying steam, it is possible to drive the vehicle extremely smoothly.

FIG. 4 is a diagram showing another embodiment of the invention.

This embodiment is an example in which steam generation l111v is provided with combustion 111171' for auxiliary heating. Combustion 111F is carried out by fuel injection valve 18. Air pump 11. It is configured with a spark plug 20, etc., and is controlled to operate when the steam temperature and steam pressure in the steam accumulator 12 fall below a set value, and the steam temperature in the steam accumulator 12 is controlled even when the vehicle is stopped for a long time.

This is to prevent the steam pressure from decreasing. Therefore, even during cold operation after being stopped for a long time, the main engine 1v can be started by the Rankine engine. Note that 21 and 22 are clutches.

As explained above, this engine is equipped with a steam inlet IIK steam 7-kine mulator for the Rankine engine expander, and the main engine is stopped during fitting operation, and when restarted, the steam in the steam akiniulator is installed. Since the configuration is such that the Rankine engine performs row 5 to 5 control based on the state, fuel efficiency can be improved in city driving where there is a lot of idling. In addition, by stopping the main engine during vehicle operation, it is possible to reduce idle noise when the vehicle is stopped (muffled noise on the 41st wheel), and smooth restarting is possible. can get.

[Brief explanation of the drawing]

The first @l is a configuration diagram of a conventional combined engine system, and the second
IQ is a configuration diagram of a composite engine system showing an embodiment of the present invention, FIG. 3 is a diagram showing an example of the control circuit of FIG. 2,
The fourth @ is a configuration diagram showing another embodiment of the present invention. In the figure, 1 is the main engine, 2 is the exhaust pipe, 3 is the steam generator,
4 is the expander, S is the capacitor, 6 is the supply pump,
T is a power transmission device, 12 is a steam akimulator, 14
1 is a steam pulp, 15 is a temperature sensor, and 1 is a pressure sensor. Figure 1

Claims (1)

[Claims] In a composite engine system including a steam generator, an expander, a condenser, and a liquid feed pump, and having a Rankine engine operated by the exhaust heat of the main engine, a steam 7 chiemulator is provided at the steam inlet 11 of the expander, and the steam 7 If the steam temperature and steam pressure in the steam generator are above the set values, the main engine is stopped during idling operation, and the main engine is restarted by the Rankine engine. **Composite engine system.