EP2481898A1 - Cooling system for a rail vehicle - Google Patents

Abstract

The system has two heat generators comprising respective cooling circuits (1, 10) i.e. high-temperature cooling circuits. A balancing unit comprising a cooling medium-heat exchanger draws the cooling circuit of one of the heat generators for assisting the cooling circuit of another heat generator when degree of utilization of the former cooling circuit is smaller than degree of utilization of the latter cooling circuit, where the degree of utilization is the ratio between actual cooling power requirement and actual cooling power potential.

Description

The invention relates to a cooling system for a powered railway vehicle, with at least two heat generators whose heat has to be dissipated, and which each have at least one cooling circuit. As drives come for example diesel-hydraulic drives into consideration, diesel-electric drives, electric drives, gas turbines.

The design of a cooling system for a rail vehicle depends on a variety of factors. First, the basic concept of the rail vehicle - whether it is a locomotive or a railcar - decides on the available space in the rail vehicle and thus on the design and arrangement of the cooling system in the rail vehicle. While railcars mainly serve to carry passengers, locomotives are also used in freight trains, but are also suitable for the rapid transportation of passengers. Of course, depending on the basic concept of the rail vehicle, its drive power is also important. When using high-performance locomotives, a larger waste heat is generated than is the case, for example, with low-power railcars. The performance of the cooling system must therefore be adapted to the performance of the rail vehicle. Also to be noted is the number of units, such as fan systems and air conditioning systems for the interior cooling of railcars and wagons or auxiliary equipment in railway maintenance vehicles and locomotives. Furthermore, the climatic conditions at the place of use of the rail vehicle in the design of a cooling system must be included. Also, the geographical location of the sites and thus the route profile decide on the performance of the rail vehicle and its cooling system.

Such cooling systems for rail vehicles have long been known. They essentially comprise one or more fans and one or more Heat exchangers which are arranged in at least one cooling circuit. In this case, a cooling medium is conveyed in the cooling circuit by means of a pump, waste heat being taken up by the drive system and the units from the cooling medium in order to release it to the environment via an air volume flow which flows through relatively large heat removal surfaces of the heat exchangers. For this purpose, cooling systems with one, two or more separate coolant circuits have been used in the past. Such cooling systems have, for example, a high-temperature cooling circuit, in particular for cooling the internal combustion engine and its lubricating or hydraulic oils, and a low-temperature circuit, for example for cooling the charge air for the internal combustion engine. Depending on the cooling circuit, high-temperature and low-temperature heat exchangers are also used. Corresponding high and low temperature circuits can also be found in electrically driven vehicles, for example for transformer and frequency converter cooling.

The structural complexity of cooling systems is high. Every single cooling circuit needs at least piping, fans and other aggregates. The individual heat generators such as engine, brake, etc. have a variable cooling requirement over time. The cooling requirements are thus different levels, from single cooling circuit to single cooling circuit, as well as over time. The cooling capacity potential of each cooling circuit also has a variable time profile and depends, for example, on the current outside temperature, the air humidity, the degree of soiling and the air pressure. Each individual cooling circuit therefore does not always work within the range of optimum efficiency, but also outside of it.

The invention has for its object to provide a cooling system that has a lower energy consumption and thus lower operating costs, and generates less noise.

This object is solved by the features of claim 1. Accordingly, means are provided for adding to the single cooling circuit of a first heat generator the single cooling circuit of a second heat generator for assistance when the utilization rate of the first circuit is lower than the utilization rate of the second circuit. Thus, a mutual support of the individual cooling circuits takes place. A typical example of two heat generators with temporally different cooling requirements are a motor and a retarder. During normal driving, the engine as a heat generator needs cooling power, but the retarder does not. The cooling circuit of the retarder can therefore support those of the engine. This comes especially into consideration when the engine gives off increased power, for example when driving uphill.

Conversely, the retarder requires high cooling capacity when driving downhill. But just then the required cooling capacity of the engine is minimal.

When forming the cooling system with at least two cooling circuits thus part of the costs incurred in a cooling circuit cooling capacity is transferred to the other cooling circuit. This is possible if the other cooling circuit currently applies a lower than its maximum possible cooling capacity and thus has a low cooling requirement. Thus, the cooling capacity acting as a reserve (difference between the maximum possible cooling capacity and the current cooling capacity) of the other cooling circuit is used for the cooling of the cooling medium of the one cooling circuit.

According to a first embodiment, the means for controlled distribution comprise a cooling medium heat exchanger which is connected to the cooling circuits so that heat energy of the one cooling circuit is transferable via the cooling medium heat exchanger to the other cooling circuit, wherein the cooling medium heat exchanger flowing through the cooling medium amount is adjustable by means of a regulator. In other words, thus the cooling capacity of the one cooling circuit is extended by the cooling medium of the other cooling circuit is used in addition to the cooling.

According to a second embodiment, the means comprise a mixing device for mixing the cooling media of the cooling circuits, wherein the mixing device via a connecting line in each case the supply line and / or return line of the cooling circuits interconnected by cooling medium, wherein the cooling medium flowing through the connecting line by means of a respective regulator in the connecting line is adjustable ,

According to a third embodiment, the heat exchanger functioning as a cooler has a plurality of heat exchanger surfaces through which cooling medium flows, which can be connected to one another in the manner of a cooling medium. Furthermore, the means comprise devices for at least partial connection or disconnection of the flow around individual heat exchanger surfaces with cooling medium. This means that the effective total heat exchanger surface flown by the cooling medium can be varied according to the heat output currently required between the circuits. The total area of the heat exchanger thus remains the same. However, it is allocated to the individual cooling circuits depending on the load.

According to a fourth embodiment, the Mitteil lines for cooling medium-conducting connection respectively of the flow lines and / or return lines of the cooling circuits, wherein the lines flowing through the cooling medium quantities are adjustable by means of regulators. By connecting the flow lines, for example, two cooling circuits and the return lines with each other is achieved that the cooling medium from all connected in this way cooling circuits, the heat exchanger surfaces as a heat exchanger acting radiator flows. In other words, the heat exchanger surfaces of the radiator with a relatively low degree of utilization are used to support the cooling of the one cooling circuit with a currently high degree of utilization.

According to a fifth embodiment, the cooling medium cooled by the drive motor and / or the at least one heat generating unit is cooled by means of at least two unit heat exchangers, wherein a first unit heat exchanger in a first cooling circuit and a second unit heat exchanger in a second cooling circuit is arranged and both unit heat exchanger based on the flowing through them , Cooling medium to be cooled are connected in parallel or in series with each other. This ensures that the unit, which is arranged in the cooling circuit with currently high cooling demand, yet sufficiently cooled, in addition, the resulting heat in the unit is transferred to the cooling circuit lower cooling demand.

Of course, it would be conceivable to combine the means described in the embodiments for the controlled distribution of the cooling capacity occurring in a cooling circuit.

• Es wird ein erster Kühlkreislauf dann zur Unterstützung eines zweiten Kühlkreislaufes herangezogen, wenn der Auslastungsgrad des ersten Kühlkreislaufes geringer ist als jener des zweiten Kühlkreislaufes. Dabei wird unter dem Auslastungsgrad das Verhältnis zwischen dem aktuellen Kühlleistungsbedarf und dem aktuellen Kühlleistungspotenzial verstanden.

In general, the invention can be defined as follows:

• A first cooling circuit is then used to support a second cooling circuit when the degree of utilization of the first cooling circuit is lower than that of the second cooling circuit. The degree of utilization is understood to mean the ratio between the current cooling capacity requirement and the current cooling capacity potential.

The invention will now be explained by way of example with reference to embodiments and the figures shown.

Figur1

eine schematische Darstellung einer Kühlanlage eines Schienenfahrzeugs mit einem als Verbrennungsmotor ausgeführten Antriebsmotor;

Figur 2

eine schematische Darstellung einer Kühlanlage eines Schienenfahrzeugs mit einem dieselelektrischen Antrieb;

Figur 3

eine schematische Darstellung einer Kühlanlage eines Schienenfahrzeugs mit einem rein elektrischen Antrieb;

Figuren 4 bis 9

jeweils eine schematische Darstellung eines Kühlsystems einer Kühlanlage gemäß unterschiedlicher Ausführungsformen.

Show it:

Figur1

a schematic representation of a cooling system of a rail vehicle with a drive motor designed as an internal combustion engine;

FIG. 2

a schematic representation of a cooling system of a rail vehicle with a diesel-electric drive;

FIG. 3

a schematic representation of a cooling system of a rail vehicle with a purely electric drive;

FIGS. 4 to 9

each a schematic representation of a cooling system of a cooling system according to different embodiments.

In FIG. 1 is a cooling system comprising a cooling circuit 1, which is designed here as a high-temperature cooling circuit shown. In the present embodiment, the following components are connected in series in the flow direction of the cooling medium circulated therein: a drive motor 4, a heat exchanger 3, which is designed as a liquid-air cooler, a further heat exchanger 9, which is designed as a liquid-liquid cooler, and a Cooling medium pump 2 for circulating the cooling medium. Of course, the components could be arranged in a different order than shown here.

Due to the heat generated by the drive motor 4 due to the drive power transmission via a gear 8 on drive wheels 15 of the rail vehicle heat in the transmission 8 is discharged via the heat exchanger 9 in the cooling medium of the cooling circuit 1. For this purpose, the transmission oil of the transmission 8 via appropriate Lines for heat dissipation with the heat exchanger 9 connected in flow.

The heat arising in the cooling circuit 1 is dissipated via the heat exchanger 3, which in the present case is flowed through by cooling air circulated by means of a fan 19. The resulting heat in the cooling circuit 1 is thus dissipated convectively into the external environment.

In the FIG. 1 is shown in dashed lines another cooling circuit 10. The latter is in the present case designed as a low-temperature cooling circuit. In the present case, the following components are arranged one behind the other in the flow direction of the cooling medium circulating therein: a cooling medium pump 12, a heat exchanger 14, which is embodied here as an air-liquid cooler, another heat exchanger 13, in the present case designed as an air-liquid cooler, and an additional heat exchanger 11, for example a hydrostatic device. In the present case, the heat exchanger 13 is assigned a separate fan 20. Of course, it would be conceivable that both heat exchangers 3, 13, for example, viewed in the flow direction of the cooling air, could be arranged one behind the other, wherein both heat exchangers 3, 13 could be assigned a common fan.

With the heat exchanger 14, the compressed by means of a compressor 17 of an exhaust gas turbocharger 16 fresh air is intermediately cooled before it is supplied to the drive motor 4 again. To drive the compressor 17, the exhaust gas emerging from the drive motor 4, which acts on a turbine 18, which is in drive connection with the compressor 17 of the exhaust gas turbocharger 16, acts.

The in the FIG. 2 shown cooling system differs from the in FIG. 1 represented by the fact that instead of the transmission 8 now an electrical Generator 21 is directly in drive connection with the drive motor 4, which electrical power via a power converter 22 on traction motors 23, which drive, for example via an axle drive wheels 15 transmits. The generator 21, power converter 22, traction motor 23 and the axle drive can be understood as heat generating units and thus be connected to the cooling circuits 1, 10 for cooling (not shown). Alternatively, as shown, they may be cooled via respective fans associated with each individual unit.

In FIG. 3 is a further schematic representation of a cooling system of a rail vehicle shown. In this case, the rail vehicle is driven in the present case purely electrically, for which purpose the rail vehicle to drive the electrical energy from a traction current line 25 takes, which is fed to a transformer 24 for conversion. The transformer 24 is connected to a power converter 22 and the traction motors, of which only one designated by the reference numeral 23, shown, is electrically connected. The cooling circuit 1 is used for cooling the transformer 4 flowing through the transformer oil, the cooling circuit 10 is used for cooling the converter 22 flowing through the coolant. Both heat exchangers 3, 13 are in the present case connected in series in the flow direction of the cooling air flowing against them. Both heat exchangers 3, 13 are assigned a single fan 19 in the present case.

The FIGS. 4 to 9 each show a preferred embodiment of a cooling system for a rail vehicle, where there the drive motor 4 of both cooling circuits 1, 10 is cooled, for example by the exchange of heat - see reference numerals 6 and 7. The cooling systems shown there are simplified, so that additional, in the FIGS. 1 to 3 shown components are not shown there. The in the FIGS. 4 to 9 shown However, embodiments could be incorporated in the FIGS. 1 to 3 used cooling systems are used, even in combination.

The FIG. 4 essentially shows the item FIG. 1 , Here is a heat-generating unit 5, which, for example, the transmission 8 from the FIG. 1 corresponds, via an aggregate heat exchanger 26 for heat dissipation to the cooling circuit 1 thermally conductively connected.

In FIG. 5 is the subject of FIG. 4 shown, wherein the unit heat exchanger 26 with respect to the cooling medium flowing through it, a further unit heat exchanger 27 is connected in parallel. In this case, the additional unit heat exchanger 27 is arranged in the second cooling circuit 10 such that the cooling medium of the unit 5 is also cooled by the cooling circuit 10. In the junction of the unit heat exchanger 26 and 27 with the unit 5 connecting lines a regulator is arranged, by means of which the flow rate of the cooling medium to the unit heat exchanger 27 is variably adjustable. As a result, the cooling capacity of the second cooling circuit 10 for cooling the unit heat exchanger 27 can be set variably. This can be regulated or controlled how much cooling capacity is transferred from the cooling circuit 1 to the cooling circuit 10.

The FIG. 6 shows a further embodiment under development of the subject FIG. 5 , In contrast to FIG. 5 are in FIG. 6 the two unit heat exchangers 26 and 27 connected in series. In the connecting line between the two unit heat exchangers 26 and 27, in turn, a controller for variable adjustment of the cooling medium throughput is provided.

The FIG. 7 shows a further embodiment based on the in FIG. 4 represented item. There are in the FIG. 7 symbolically three each Heat exchanger surfaces of the heat exchanger 3 and 13 shown, which in the present case are flown by the cooling air flow generated by the fans 19 and 20. In this case, the individual heat exchanger surfaces of the heat exchangers 3, 13 are designed such that they can be selectively flowed by the cooling medium of the cooling circuits 1 and 10. For this purpose, corresponding valves and regulators for adjusting, for example, the amount of cooling medium through the heat exchangers 3, 13 are provided. Thus, with little need for cooling, one or more heat exchanger surfaces can be switched off so that they are not affected by the cooling medium and / or cooling air. In this case, the heat exchangers 3, 13 in the corresponding cooling circuits 1, 10 respectively via flow lines 29 and 32 for supplying cooling medium and return lines 30, 33 for discharging cooling medium from the heat exchangers 3, 13 with the corresponding cooling circuits 1, 10 connected in flow.

In the present case, each of the flow lines 29 and 32 of the cooling circuits 1 and 10 and the return lines 30 and 33 are connected to each other via corresponding lines. In the lines turn regulator for adjusting the cooling medium flow rate are arranged. In this way, for example, at a high cooling load of the cooling circuit 10 of the circulating therein cooling medium, for example, in addition heat exchanger surfaces that are otherwise flown by the cooling medium of the cooling circuit 1, are flown. Thus, for example, both heat exchangers 3, 13 are used for cooling the circulating in the cooling circuit 10 cooling medium. Depending on the cooling load, of course, also heat exchanger surfaces of the heat exchanger 13 can be used for cooling the circulating in the cooling circuit 1 cooling medium. In a further embodiment, therefore, the entire heat exchanger surface can be variably allocated to the cooling circuits.

According to the in FIG. 8 shown embodiment, which is a development of the subject FIG. 4 represents, both cooling circuits 1, 10 are connected via a cooling medium heat exchanger 28 heat transferring together. In this case, the cooling medium heat exchanger 28 is connected in such a manner to the cooling medium circuit with the two cooling circuits that cooling medium is supplied from the flow line 29 to the flow line 32.

In the FIG. 9 is still another embodiment of the cooling system according to the invention under development of the subject from the FIG. 4 shown. Unlike in the FIGS. 4 to 8 shown cooling systems in which heat energy of a cooling circuit is transferred to the other cooling circuit indirectly via a heat exchanger, is in the FIG. 9 the heat energy achieved by mixing the cooling media of both cooling circuits. For this purpose, a mixing device 11 is provided in the present case, which connects each of the flow lines 29 and 32 and the return lines 30 and 33 of the two cooling circuits 1 and 10 with each other cooling medium. Regulator 31 are provided in the lines to adjust the volume flow of the cooling medium flowing through the lines corresponding to the cooling load of the two cooling circuits 1 and 10.

LIST OF REFERENCE NUMBERS

1

Cooling circuit

2

Coolant pump

3

heat exchangers

4

drive motor

5

heat generating unit

6

Proportionate heat input of the heat generating unit

7

Proportionate heat input of the heat generating unit

8th

transmission

9

heat exchangers

10

Cooling circuit

11

mixing device

13

heat exchangers

12

Coolant pump

14

heat exchangers

15

drive wheels

16

turbocharger

17

compressor

18

turbine

19

Fan

20

Fan

21

generator

22

current direction

23

traction motor

24

transformer

25

Driving power line

26

Unit heat exchanger

27

Unit heat exchanger

28

Cooling medium heat exchanger

29

supply line

30

Return line

31

regulator

32

supply line

33

Return line

Claims (7)

Cooling system for a powered rail vehicle 1.1 with at least two heat generators, 1.2 each having at least one cooling circuit (1, 10); 1.3 compensation means are provided to use a first single cooling circuit of a first heat generator to support a second single cooling circuit of a second heat generator, when the utilization rate of the first single cooling circuit is less than the utilization rate of the second single cooling circuit, the utilization ratio, the ratio between the current cooling power requirement and the current Cooling capacity potential is. Cooling system according to claim 1, characterized in that the compensating means comprise a cooling medium heat exchanger (28), the Kühlmediumleitend with the single cooling circuits (1, 10) is connected, and that the cooling medium heat exchanger (28) flowing through the cooling medium amount is adjustable by means of a regulator , Cooling system according to claim 2, characterized in that the cooling medium heat exchanger (28) is connected to the individual cooling circuits (1, 10) such that cooling medium flows through the cooling medium heat exchanger (28) from the respective flow line (29, 32) of the single cooling circuit , Cooling system according to one of claims 1 to 3, characterized by the following features: 4.1 the compensating means comprise a mixing device (31) for mixing the cooling media of the individual cooling circuits (1, 10); 4.2 the mixing device (31) is connected via a connecting line in each case with the flow lines (29, 32) and / or return lines (31) of the individual cooling circuits (1, 10); 4.3 there is provided a regulator for adjusting the flow rate of the cooling medium in the connecting line. Cooling system according to one of claims 1 to 4, characterized by the following features: 5.1 of the heat exchanger (3, 13) has a plurality of cooling medium flowed through by heat exchanger surfaces which are interconnected with each other cooling medium; 5.2 the compensating means comprise means or measures to at least partially switch the cooling medium flowing around the heat exchanger surfaces between the individual cooling circuits (1, 10). Cooling system according to one of claims 1 to 5, characterized in that the compensating means comprise lines for connecting the flow lines (29, 32) and / or the return lines (30, 33) of the individual cooling circuits (1, 10), and that regulators for adjusting the Throughput of the cooling medium in the lines (30, 33) are provided. Cooling system according to one of claims 1 to 6, characterized by the following features: 7.1 a heat generator are associated with two or more individual heat exchanger (26, 27); 7.2 a first individual heat exchanger (26) is arranged in a first single cooling circuit (1), and a second individual heat exchanger (27) in a second single cooling circuit (10); 7.3 the two individual heat exchangers (26, 27) are connected in parallel or in series.

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