DE10301797A1 - Internal combustion engine with coolant circuit, has coolant pump connected to fourth switching element on outlet side, heat storage device connected to fifth switching element on input side - Google Patents

Abstract

The engine has a coolant circuit divisible into at least two heating circuits, engine coolant outlets and a coolant collection outlet. The first heating circuit has 2 switching elements for connection to the first coolant and collection outlets. The second has fourth and fifth switching elements either side of a heat exchanger. A coolant pump outlet is connected to the fourth element. A heat storage device input is connected to the fifth element. The engine has a coolant circuit (1), first and second engine coolant outlets (18,20) and a coolant collection outlet (19). The coolant circuit can be divided into at least first and second heating circuits (2,6). The first heating circuit has first and second switching elements (8,9) via which it can be connected to the first coolant outlet and the collection outlet. The second heating circuit has fourth and fifth switching elements (11,12) at the input and output sides of a heat exchanger (7). A coolant pump (3) is connected to the fourth switching element on its outlet side and a heat storage device is connected to the fifth switching element on its input side

Description

The invention relates to an internal combustion engine with a coolant circuit according to the characteristics in the preamble of claim 1.

It is based on a conventional one Coolant circuit with an engine oil / water heat exchanger and one in one Secondary circuit arranged heat storage from, for example, as optional equipment in the BMW 525 tds vehicle was offered until 1998. During normal engine operation becomes waste heat of the engine which over the coolant circuit to that as latent heat storage (LWS) trained heat storage arrives, temporarily stored in this as soon as the melting temperature of the storage medium in the LWS is exceeded. The absorbed "latent heat" remains after the engine has stopped longer in vacuum-insulated LWS Receive time and can next Engine start for quick heating of the coolant be used. Through this . Measure will be a quick heating up of the passenger compartment and the defrost behavior on the windows significantly improved. About that it is also a simple and inexpensive option without auxiliary heating to warm up the passenger interior quickly. Thus the Latent heat storage not only the well-being of the passengers, but also increases driving safety at low outside temperatures.

To achieve multifunctionality is next to the use of the heat storage in operating cases with heating request ("winter operation") also use in operational cases provided without heating request ("summer operation"), whereby in the first case the heat accumulator together with the heating heat exchanger and an additional electrical coolant pump its own, from the coolant circuit of the engine completely decoupled Partial cycle forms and in the second case either by introduction the one in the heat storage contained heat energy over the Heating return a reduction in fuel consumption in the engine water jacket due to a reduction in the engine friction or when the engine is warm Motor a renewed storage of thermal energy from reaching the melting temperature of the storage medium takes place.

Because of the high transmission losses from the heat accumulator to the cooling water as a result of being called heat sinks acting mass components of the cylinder crankcase and the water jacket The cylinder head remains the transition that can be achieved with the heat storage arrangement of thermal energy from the coolant that the height the engine oil determining engine friction, so that only a minor one Impact on fuel consumption is achieved.

Object of the present invention is a generic coolant circuit to demonstrate with which the passenger interior, as before, but also for example the engine oil can be heated after a cold start of the engine.

This task is due to the characteristics solved in the characterizing part of claim 1.

In addition to the beginning of the Technology mentioned Possibility, to heat the passenger interior with the help of the heat accumulator according to the positions of the switching elements also possible Internal combustion engine or parts thereof, such as the lubricant, to warm up quickly after starting the internal combustion engine. In depending on the coolant temperature level in the internal combustion engine either the thermal energy contained in the heat storage via the Heating return and the coolant collection outlet, a thermostatic valve in the engine water jacket fed in or a renewed heat energy storage from reaching a selectable Limit value of the coolant temperature on Internal combustion engine exit carried out. With the proposed one Arrangement are different switching positions of the switching elements, as well as winter operation as well for the summer operation that later explained in detail become realizable.

According to claim 2, the Switching effort for a change in the cooling circuit significantly reduced to another operating mode.

Because the coolant circuit at the same time thermal management for the Represents internal combustion engine, are the switching elements according to claim 3 can be switched in a temperature-controlled manner in an advantageous manner. Show for this them according to claim 4 a first and a second switching position.

According to claim 5, the second heating circuit for the passenger compartment temperature control is completely self-sufficient so that the heat accumulator exclusively for the Passenger compartment heating to disposal stands.

The arrangement of the exhaust gas cooling circuit according to claim 6 is despite its complete Integration in the heating circuit regardless of any switching position of the switching elements in the heating circuit. Regardless of winter or summer operation can the exhaust gas cooling circuit constantly completely operated independently and with a valve, preferably a thermostatic valve, be managed.

In the same way regardless the exhaust gas cooling circuit is also the third circuit, the actual cooling circuit of the internal combustion engine, to operate completely independently. The third heating circuit is used to remove excess waste heat from the internal combustion engine over the third heat exchanger, an engine cooler dissipate the environment.

With the proposed in claim 8 Switching valves is a simple structure, as well as a simple and safe operation of the cooling circuit possible.

The following is the state of the art in a single figure, as well as an embodiment according to the invention of a preferred embodiment in five other figures closer explained.

1 schematically shows a conventional cooling circuit;

2 shows schematically an inventive development of the prior art;

3 shows a position of the switching elements for cooling the internal combustion engine without heat storage;

4 shows a position of the switching elements for heating the passenger compartment with waste heat from the internal combustion engine;

5 shows a position of the switching elements for heating the passenger compartment with waste heat from the heat accumulator;

6 shows a position of the switching elements for heating the lubricant of the internal combustion engine with waste heat from the heat accumulator.

1 shows schematically a conventional cooling circuit 1 an internal combustion engine, here for a 6-cylinder diesel engine, installed in the vehicle BMW 525 tds, built in 1998. An internal combustion engine 17 , with a cylinder head 17a and a crankcase 17b points to the cylinder head 17a a first coolant outlet 18 and a coolant collection outlet 19 , a thermostat housing with a thermostat, and a second coolant outlet 20 on. In a coolant circuit internal to the engine, the coolant can be pumped 21 , a coolant pump, through a coolant inlet 22 in the crankcase 17b and out of the crankcase 17b further into the cylinder head 17a and from there into the coolant collection outlet 19 be pumped. Via a coolant line 25 the coolant passes from the coolant collection outlet 19 back to the second coolant pump 21 ,

In addition to the internal coolant circuit, the internal combustion engine has 17 via an external coolant circuit 1 , The external coolant circuit 1 has a third cycle 23 on, the regular coolant circuit of an internal combustion engine for cooling the coolant. The coolant circuit 23 is fed from the first coolant outlet 18 , The coolant is supplied by the second coolant pump 21 into a third heat exchanger 16 , a conventional engine cooler, pumped and from there back to the coolant collection outlet 19 ,

Furthermore, the coolant circuit 1 an exhaust gas cooling circuit 13 on, also from the second coolant outlet 18 is fed. The coolant passes through an exhaust gas cooler for exhaust gas cooling 14 , with a valve arranged on it 15 , preferably a thermostatic valve, for regulating the amount of coolant for the exhaust gas cooling. After the valve 15 the coolant becomes the coolant collection outlet 19 recycled.

In addition, the heating circuit 1 a first heating circuit 2 to temper the interior of the passenger. The heating circuit 2 is also from the first coolant outlet 18 fed. The first heating circuit 2 has a first switching element in the flow direction of the coolant 8th , a first coolant pump 3 , a third switching element 10 , a first heat exchanger 4 , a heating heat exchanger for the temperature control of the passenger compartment, and a second switching element 9 on. Furthermore, in the first heating circuit 2 a heat store 5 arranged, a latent heat storage. The exit of the heat storage 5 is both with the first switching element 8th , as well as with a sixth switching element 25 connected with coolant. Depending on the position of the switching element 25 the coolant to the coolant collection outlet 19 be recycled, or the first heating circuit 2 opposite the coolant collection outlet 19 be closed. With the first heating circuit 2 depending on the switching position of the switching elements 8th . 9 . 10 and 25 either a closed circuit can be represented, so the waste heat from the heat accumulator 5 is used exclusively for the temperature control of the passenger compartment, or the waste heat from the internal combustion engine 17 for heating the heat storage 5 serves.

The cooling circuit also has 1 via a second heating circuit 6 that from the second coolant outlet 20 is fed. The coolant flows through a second heat exchanger 7 , here a lubricant / coolant heat exchanger, then a thermostat 24 that is the flow rate of the coolant through the second heat exchanger 7 regulates depending on the lubricant temperature. After the thermostat 24 the coolant becomes the coolant collection outlet 19 returned. With the second heating circuit 6 becomes the lubricant of the internal combustion engine with the help of the thermal energy contained in the coolant 17 warmed up. That in the second heat exchanger 7 Lubricant entering and leaving is indicated by arrows with temperature measuring points in the form of circles.

2 shows schematically an inventive development of the prior art described above. The reference numerals from 1 apply to the same components in the 2 to 6 , Because the basic structure of the cooling circuit 1 largely corresponds to the state of the art for the following 2 to 6 only the differences 1 explained. The one in the 2 to 6 cooling circuit shown for different operating states 1 is identical for all operating states, only the switching valves are in different switching positions according to the following table.

Across from 1 is for everyone 2 to 6 the sixth switching element 25 omitted. Instead of the thermostat 24 is a fifth switching element 12 on the output side to the second heat exchanger 7 arranged. Furthermore, the cooling circuit according to the invention 1 inlet side of the second heat exchanger 7 a fourth switching element 11 on. The fourth switching element 11 is coolant-carrying with a pump outlet of the first coolant pump 3 connected. The fifth switching element 12 is coolant-carrying with an entrance to the heat accumulator 5 , and the coolant collection outlet 19 connected.

In the 3 to 6 the lines through which the coolant flows are shown as “wide” and the lines through which the flow does not flow are “narrow”.

The first switching element 8th and the second switching element 9 , as well as the fourth and fifth switching element 11 . 12 are switched simultaneously. The four switching elements 8th . 9 . 11 . 12 are individual 2/2-way valves or 3/2-way valves, but can also be installed together in a single valve block. Instead of a latent heat store, other types of heat stores can also be used.

With the proposed arrangement, the following switching positions for the switching elements 8th . 9 . 10 . 11 . 12 possible. The data in the table refer to the 3 to 6 , The switching position of the switching elements 8th . 9 . 10 . 11 . 12 is identified by a or b. Position a means that side a of the switching element is active, position b means that side b of the switching element is active.

• 1. Stellung „C" (5): Bei Heizanforderung und einer Kühlmitteltemperatur am Kühlmittelaustritt 20 unterhalb eines festgelegten Grenzwertes wird der Fahrgastinnenraum mit der Abwärme des Wärmespeichers 5 beheizt. Diese Stellung wird solange beibehalten, bis die Kühlmitteltemperatur am Kühlmittelaustritt 20 in etwa der Kühlmitteltemperatur an einem Kühlmittelauslass des Wärmespeichers 5 entspricht, d. h. die Zeitdauer ist vom Beladungszustand (gespeicherte Wärmeenergiemenge) des Wärmespeichers 5 abhängig.
• 2. Stellung „B" (4): Wenn die Kühlmitteltemperatur am Kühlmittelaustritt 20 in etwa der Kühlmitteltemperatur am Kühlmittelauslass des Wärmespeichers 5 entspricht, wird der Fahrgasinnenraum mittels Abwärme der Brennkraftmaschine 17 weiter beheizt, bis zum Erreichen eines festgelegten Grenzwertes „X" der Schmiermitteltemperatur an einem Schmiermittelauslass des zweiten Wärmetauschers 7. Der Wert „X" ist von der Wärmespeicherausführung abhängig. Im Fall eines Latentwärmespeichers beispielsweise von der Schmelztemperatur des Speichermediums.
• 3. Stellung „E" (6): Oberhalb des festgelegten Grenzwertes „X" der Schmiermitteltemperatur kann der Wärmespeicher 5 erneut, bis zum Erreichen einer festgelegten Grenztemperatur der Kühlmitteltemperatur am Kühlmittelauslass des Wärmespeichers 5, beladen werden.
• 4. Stellung „B" (3) oder „A" (4): Je nach Weiterbestehen der Heizanforderung für den Fahrgastinnenraum.

In addition to the switch positions corresponding to a conventional cooling system "Cooling of the internal combustion engine without using heat storage ( 3 ) "and" Passenger compartment heating with waste heat from the internal combustion engine ( 4 ) ", the waste heat from the heat accumulator can be used according to the following strategies based on the configuration according to the invention:
After starting the internal combustion engine in winter operation:

• 1st position "C" ( 5 ): When there is a heating request and a coolant temperature at the coolant outlet 20 The passenger interior with the waste heat from the heat accumulator is below a specified limit value 5 heated. This position is maintained until the coolant temperature at the coolant outlet 20 approximately the coolant temperature at a coolant outlet of the heat accumulator 5 corresponds, ie the time period depends on the load (stored amount of thermal energy) of the heat accumulator 5 dependent.
• 2nd position "B" ( 4 ): When the coolant temperature at the coolant outlet 20 approximately the coolant temperature at the coolant outlet of the heat accumulator 5 corresponds to the passenger compartment by means of waste heat from the internal combustion engine 17 heated further until a specified limit value "X" of the lubricant temperature is reached at a lubricant outlet of the second heat exchanger 7 , The value "X" depends on the heat storage design. In the case of a latent heat storage, for example on the melting temperature of the storage medium.
• 3rd position "E" ( 6 ): The heat accumulator can exceed the specified limit value "X" of the lubricant temperature 5 again until the coolant temperature at the coolant outlet of the heat accumulator is reached 5 , be loaded.
• 4th position "B" ( 3 ) or "A" ( 4 ): Depending on the heating requirement for the passenger compartment.

• 1. Stellung „D" (6): Das den zweiten Wärmetauscher 7 durchströmende Schmiermittel wird über den Wärmespeicher 5 beheizt. Diese Stellung wird so lange beibehalten, bis die Schmiermitteltemperatur am Kühlmittelaustritt des zweiten Wärmetauscher 7 der Kühlmitteltemperatur am Kühlmittelaustritt des Wärmespeichers 5 erreicht. Dies ist eine festgelegte Temperatur „Z".
• 2. Stellung „A" (3): Wenn die Schmiermitteltemperatur am Kühlmittelaustritt des zweiten Wärmetauscher 7 der Kühlmitteltemperatur am Kühlmittelaustritt des Wärmespeichers 5 entspricht (festgelegter Wert „Z"), wird die Brennkraftmaschine 17 in dieser Stellung bis zum Erreichen des festgelegten Grenzwertes „X" der Schmiermitteltemperatur am Schmiermittelein- oder austritt des zweiten Wärmetauschers 7 betrieben.
• 3. Stellung „E" (6): Oberhalb der festgelegten Grenztemperatur „X" des Schmiermittels kann der Wärmespeicher 5 erneut bis zum Erreichen einer festgelegten Grenztemperatur des Kühlmittels am Kühlmittelaustritt des Wärmespeichers 5 beladen werden.
• 4. Stellung „A" (3):

After starting the internal combustion engine in summer:

• 1st position "D" ( 6 ): The second heat exchanger 7 Lubricant flowing through is stored in the heat accumulator 5 heated. This position is maintained until the lubricant temperature at the coolant outlet of the second heat exchanger 7 the coolant temperature at the coolant outlet of the heat accumulator 5 reached. This is a fixed temperature "Z".
• 2nd position "A" ( 3 ): When the lubricant temperature at the coolant outlet of the second heat exchanger 7 the coolant temperature at the coolant outlet of the heat accumulator 5 corresponds (fixed value "Z"), the internal combustion engine 17 in this position until the specified limit value "X" of the lubricant temperature at the lubricant inlet or outlet of the second heat exchanger is reached 7 operated.
• 3rd position "E" ( 6 ): Above the specified limit temperature "X" of the lubricant, the heat accumulator can 5 again until a specified coolant limit temperature is reached at the coolant outlet of the heat accumulator 5 be loaded.
• 4th position "A" ( 3 ):

• – Hohes Verbrauchssenkungspotential;
• – Multifunktionale Nutzung bei hohem Übertragungswirkungsgrad;
• – Hohe Energiedichte als Kraftstoffzuheizer bei geringerem Preis;
• – Erhöhung von Heizkomfort und Sicherheit (Scheiben-Schnellentfrostung);
• – Schaltkreis auch für Standheizungsfunktion nutzbar;
• – Einfache Steuerung über Temperaturfühler mit paarweiser Ansteuerung von je zwei Schaltelementen

The proposed system offers the following advantages:

• - High consumption reduction potential;
• - Multifunctional use with high transmission efficiency;
• - High energy density as a fuel heater at a lower price;
• - Increased heating comfort and safety (quick defrosting of windows);
• - Circuit can also be used for auxiliary heating function;
• - Simple control via temperature sensors with paired control of two switching elements each

1

Cooling circuit

2

first heating circuit

3

First Coolant pump

4

first heat exchangers

5

heat storage

6

second heating circuit

7

second heat exchangers

8th

first switching element

9

second switching element

10

third switching element

11

fourth switching element

12

Fifth switching element

13

Exhaust gas cooling circuit

14

exhaust gas cooler

15

Valve

16

third heat exchangers

17

Internal combustion engine

17a

cylinder head

17b

crankcase

18

first coolant outlet

19

Kühlmittelsammelsauslass

20

second coolant outlet

21

Second Coolant pump

22

Coolant inlet

23

third circulation

24

thermostat

25

sixth switching element

Claims (8)

Internal combustion engine ( 17 ) with a coolant circuit ( 1 ), whereby - the internal combustion engine ( 17 ) a first and a second coolant outlet ( 18 . 20 ) and a coolant collection outlet ( 19 ), - the coolant circuit ( 1 ) at least in a first heating circuit ( 2 ) and a second heating circuit ( 6 ) can be subdivided, the first heating circuit comprising a first and a second switching element ( 8th . 9 ) through which it connects to the first coolant outlet ( 18 ) and the coolant collection outlet ( 19 ) can be connected in a coolant-carrying manner, wherein - a switching element ( 8th . 9 ) between a first coolant pump ( 3 ) and a heat accumulator ( 5 ) is arranged, - the second heating circuit ( 6 ) a second heat exchanger ( 7 ) and - from the second coolant outlet ( 20 ) is fed with coolant that flows into the coolant collection outlet ( 19 ) is traceable, characterized in that - in the second heating circuit ( 6 ) on the inlet side of the second heat exchanger ( 7 ) a fourth switching element ( 11 ) and on the output side a fifth switching element ( 12 ) is arranged, - the coolant pump ( 3 ) on the output side with the fourth switching element ( 11 ) is connected to carry coolant and - the heat accumulator ( 5 ) on the input side with the fifth switching element ( 12 ) is connected to carry coolant. Internal combustion engine according to claim 1, characterized in that the first and the second switching element ( 8th . 10 ) and / or the fourth and fifth switching element ( 11 . 12 ) can be switched at the same time. Internal combustion engine according to claim 1 or 2, wherein between the coolant pump ( 3 ) and the switching element ( 8th . 9 ) a third switching element ( 10 ) is arranged. characterized in that the switching elements ( 8th . 9 . 10 . 11 . 12 ) can be switched under temperature control. Internal combustion engine according to one of the aforementioned patent claims, characterized in that the switching elements ( 8th . 9 . 10 . 11 . 12 ) have a first and a second switching position (a, b). Internal combustion engine according to claim 4, characterized in that the second heating circuit ( 6 ) is a closed circuit if the fourth and fifth switching element ( 11 . 12 ) are active in the second switch position (b). Internal combustion engine according to one of the preceding claims, wherein the cooling circuit ( 1 ) an exhaust gas cooling circuit ( 13 ), characterized in that the exhaust gas cooling circuit ( 13 ) between the first coolant outlet ( 18 ) and the coolant collection outlet ( 19 ) is arranged. Internal combustion engine according to one of the preceding claims, wherein the cooling circuit ( 1 ) a third cycle ( 23 ) with a third heat exchanger ( 16 ) for cooling the coolant, characterized in that the third circuit ( 23 ) between the first coolant outlet ( 18 ) and the coolant collection outlet ( 19 ) is arranged. Internal combustion engine according to one of the aforementioned patent claims, characterized in that the switching valves ( 8th . 9 . 10 . 11 . 12 ) 2/2-way and / or 2/3-way switching valves.