WO2008037238A1

WO2008037238A1 - Air-conditioning system for a motor vehicle

Info

Publication number: WO2008037238A1
Application number: PCT/DE2007/001384
Authority: WO
Inventors: Manfred Pfalzgraf; Markus Bedenbecker; Matthias Boltze; Andreas Engl
Original assignee: Enerday Gmbh
Priority date: 2006-09-27
Filing date: 2007-08-03
Publication date: 2008-04-03
Also published as: DE102006045674A1

Abstract

The invention relates to an air-conditioning system (12) for a motor vehicle (10), having a fuel cell. Here, it is advantageously provided that the air-conditioning system (12) is designed to be arranged in the luggage space of the motor vehicle (10). The invention also relates to a motor vehicle having an air-conditioning system of said type.

Description

_

Air conditioning for a motor vehicle

The invention relates to an air conditioning system for a motor vehicle, with a fuel cell.

Moreover, the invention relates to a motor vehicle with an air conditioner, which has a fuel cell.

From DE 102 23 949 Al a stationary air conditioner with a fuel cell for air conditioning of a vehicle is known. However, the manner in which this stationary air conditioner is mounted in a vehicle is not disclosed.

It is therefore an object of the present invention, the generic stationary air conditioning further such that easy installation with good air conditioning performance can be achieved.

This object is solved by the features of the independent claims.

Advantageous embodiments and developments of the invention düng result from the dependent claim.

The air conditioning system according to the invention is based on the generic state of the art in that the air conditioning system is designed to be arranged in the trunk of the motor vehicle. Such an arrangement of the air conditioning ensures easy installation and good retrofitting. In addition, such a placement offers the advantage that with relatively little effort the air supply - -

driving or removal can take place via a partition wall behind a vehicle rear bench seat, which leads to short air guide paths and thus to improved air conditioning performance.

With the motor vehicle according to the invention, the advantages mentioned above can be achieved in a metaphorical manner.

In this case, the motor vehicle according to the invention may be designed such that the air conditioner seen in the vehicle longitudinal direction is mounted below a rear shelf of the motor vehicle and hanging. This is a particularly space-saving arrangement, since the air conditioner is placed in an otherwise hardly used place in the trunk. The floor space of the trunk is thus not reduced, so that the space below the air conditioner can be used. Especially in motor vehicles with fold-down rear seat, the functionality of the through-loading can thus be maintained. In addition, thus the ways for air ducts in the vehicle interior can be shortened.

Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

Show it:

Figure 1 is a schematic representation of an inventive air conditioner according to a first embodiment; _

Figure 2 is a schematic representation of the motor vehicle with the air conditioner according to the invention according to the first embodiment;

Figure 3 is a schematic representation of the motor vehicle with the air conditioner according to the invention according to a second embodiment; and

FIG. 4 shows a flow chart of the air-conditioning operation according to the invention.

Figure 1 shows a schematic representation of an air conditioner according to the invention according to a first embodiment. The air conditioning system 12 installed in a motor vehicle 10, which is outlined with a dashed line, comprises as main elements a fuel cell system 14 and a refrigeration circuit 16.

The fuel cell system 14 comprises a reformer 18, to which fuel can be supplied via a fuel line 20 from a fuel tank, not shown. Further, the reformer 18 at a second Brennstoffzuführstufe by means of a fuel strand 22 also from the fuel tank fuel can be supplied. As fuel types are diesel, gasoline, natural gas and other known from the prior art types of fuel in question. Furthermore, the oxidizer 24 via a Oxidationsmittelstrang 24 Oxidati- onsmittel, ie in particular air, can be fed to the reformer 18. The reformate produced by the reformer 18 can be fed to a fuel cell stack 26. Alternatively, instead of the fuel cell stack 26, only one fuel cell may be provided. The reformate is a hydrogen-containing gas which is conveyed in the fuel cell stack 26 by means of a cathode feed line 28 _

Kathodenenzuluft is converted by generating electrical energy and heat. The generated electrical energy can be fed via an electrical line 30 to an electric motor 32, a battery 34 and an electric heater 36 of the air conditioning system 12. This can be done directly or by feeding the energy through a central node in the electrical system of the motor vehicle 10. In the illustrated case, the anode exhaust gas via an anode exhaust 38 of a mixing unit 40 of an afterburner 42 can be supplied. Furthermore, fuel can be supplied to the afterburner 42 via a fuel line 44 from the fuel tank and via an oxidant strand 46 to oxidizing agent. In the fuel strands 20, 22 and 44 are suitable, not shown conveyors, such as pumps, arranged. Likewise, in the oxidant strands 24 and 46 corresponding, not shown conveyors, in this case, preferably blower arranged. These conveyors can be powered directly from the fuel cell stack 26 or from the battery 34. In the afterburner 42, a conversion of the depleted anode exhaust gas with the pumped fuel and oxidizing agent to a combustion exhaust gas, which is mixed in a mixing unit 48 with cathode exhaust air, which is conveyed via a Kathodenabluftstrang 50 from the fuel cell stack 26 to the mixing unit 48. The combustion exhaust gas, which contains virtually no pollutants, flows through a heat exchanger 52 for preheating the cathode feed air and finally leaves the fuel cell system 14 via an exhaust gas outlet 54.

In the refrigerant circuit 16, a compressor 56, a condenser 58, an expansion device 60 and an evaporator 62 are arranged. The compressor 56 can be driven by the electric motor 32, which in turn is preferably driven by the combustion engine. _The fuel cell stack 26 of the fuel cell system 14 is supplied with energy but can also be supplied with energy by the battery 34 for a short time. The evaporator 62 is associated with a blower 64. An outside air line 66 can be used to suck in ambient air from the outside. The term "from the outside", as used in connection with this invention, means from outside the interior space 78, thus designating the air surrounding the motor vehicle 10. The outside air duct 66 leads to an adjusting device 68, which can supply the outside air to the blower 64. The air directed from the actuator 68 to the fan 64 flows past the evaporator 62 as airflow 70. In this way, the air flow 70 through the evaporator 62 heat energy can be withdrawn. The cooled air flow can then via an adjusting device 72, a

Air guide 74 and a parcel shelf 76 are supplied to a vehicle interior 78. The adjusting device 72 can be realized, for example, by a solenoid valve or by check valves, which in each case allow only one flow from the two supply lines to the air guide 74. The cooled air flows through the vehicle interior 78 and leaves it below a seat 80, preferably the rear seat. Subsequently, the air flows via an air guide 82 back to the Stellein- direction 68, where it is completely or partially discharged to the outside or back to the blower 64 is passed. For the guidance of the air to the outside, a corresponding line is provided, which is not shown for reasons of clarity. The circuit of the actuating device 68 thus makes it possible, as desired, to realize a fresh-air concept or a recirculated-air concept in which air is drawn in from outside via the outside air line 66 or the air is recirculated from the air duct 82. Mixed forms of these modes are possible. Furthermore, by means of the setting -

Device 68, the air introduced via the outside air duct 66 of an air duct 84 and via this a blower 86 are supplied. In this case, this air flows as air stream 88 on hot parts of the fuel cell system 14 directly past or by (not shown) heat exchanger, which mediate between the air stream 88 and the hot parts. The hot parts of the fuel cell system 14 are preferably the reformer 18, the fuel cell stack 26 and the afterburner 42. In this way, heat energy can be supplied to the air flow 88 by the waste heat of the hot parts of the fuel cell system 14. The heated air flow 88 leads via an air duct 90 to the electrical heating device 36, which is supplied directly by a power generated by the fuel cell stack 26 or stored by the battery 34. Thus, in a heating operation, the already preheated air in the air duct 90 can be further heated and fed via the adjusting device 72 and the air guide 74 to the interior 78. After flowing through the interior 78 of the air flow via the air guide 82 to the adjusting device 68, where it is either discharged to the outside or is passed back to the fan 86. In this case as well, it is possible, via the circuit of the adjusting device 68, to realize a recirculation concept optionally in such a heating operation, in which air is drawn in from outside via the outside air line 66 or the air is recirculated out of the air guide 82.

Below, various operating conditions are shown, which can be realized by means of the air conditioning described above:

Cooling operation with circulating air circulation: In this operating state, the adjusting device 68 is switched so that air from the interior 78 via the air guide 82 to the fan _

64 is performed. This air flow 70 is cooled and guided via the adjusting device 72 and the air guide 74 into the interior 78, whereby it is cooled. In order to avoid heating of the trunk in which the fuel system 12 is arranged during cooling operation, corresponding blowers and lines (not shown) are provided, which dissipate the waste heat of the fuel cell system 14 and the waste heat of the condenser 58 to the outside.

Cooling operation with outside air supply: In this operating state, the adjusting device 68 is switched so that outside air is guided via the outside air line 66 to the blower 64. The air flow 70 is cooled and guided via the adjusting device 72 and the air guide 74 into the interior 78. The over the air duct 82 from the interior

78 leading air flow is discharged from the actuator 68 to the outside. With regard to the removal of the waste heat of the fuel cell system 14 and the capacitor 58, the measures explained in the context of the cooling operation described above are taken.

Heating mode with circulating air circulation: In this operating state, an air flow 88 is guided from the interior 78 to the fan 86 via the air guide 82, the adjusting device 68 and the air guide 84. The refrigeration circuit 16 is not in operation, ie the electric motor 32 is not operated. The blower 86 passes the air flow 88 past the hot parts of the fuel cell system 14. The preheated in this way air is guided by the air guide 90 to the e- lectric heater 36 and on to the adjusting device 72. The electric heater 36 is operated to heat the air in the air duct 90 with electric power. Subsequently, the heated flows - ö ~

Air via the adjusting device 72 and the air guide 74 into the interior 78th

Heating mode with outside air supply: In this operating state, outside air is supplied via the outside air line 66 from the adjusting device 68 to the air guide 84. The waste heat generated by the operation of the fuel cell system 14 heats the air flow 88. This heated air flow is, as in the above-described operating state, conducted via the air guide 90, the electric heater 36, the actuator 72 and the air guide 74 in the interior 78. Subsequently, this air flow is guided via the air guide 82 to the adjusting device 68, where it is discharged to the outside.

These different operating states are controlled via an electronic control unit, which selects the suitable operating state depending on the temperature in the interior 78, outside temperature, set target temperatures and desired air conditioning operation. This electronic

Control unit is not shown in the figures for reasons of clarity, but it is immediately apparent to those skilled in the art that these at least with the corresponding conveyors in the strands 20, 22, 24, 44 and 46 of the power distribution in the electrical line 30, the blower 64 and 86, the electric heater, the electric motor 32, the adjusting means 68 and 72 and the corresponding temperature sensors is connected.

The above-described flow direction in the vehicle interior 78, ie introducing the air over the parcel shelf 76 and discharging the air below the seat 80 may also be reversed in the cooling and / or heating mode. For such a modification would have according to the air guide 74th open below the seat 80 in the vehicle interior 78 and open the air guide 82 via the parcel shelf 76 in the vehicle interior 78.

Figure 2 shows a schematic representation of the motor vehicle 10 with the inventive air conditioner 12 according to the first embodiment. In Figure 2, in particular the installation position of the air conditioner 12 is illustrated. The air conditioner 12 according to the invention can be mounted in the trunk, preferably as a retrofittable unit. In addition to the described air conditioning system 12, the motor vehicle 10 has a conventional air conditioner 92, in which a compressor of a conventional refrigeration circuit is mechanically drivable by a drive unit 94, preferably an internal combustion engine. During the travel of the motor vehicle 10 and the associated operation of the drive unit 94, the interior space 78 can be cooled in a generally known manner via the conventional vehicle-mounted air conditioning system 92 or heated by waste heat of the drive unit 94. When the drive unit 94 is at a standstill, the interior space 78 can be conditioned via the air conditioning system 12 according to the invention.

FIG. 3 shows a schematic representation of the motor vehicle with the air conditioning system according to the invention in accordance with a second exemplary embodiment. To avoid repetition, only the differences of the second embodiment from the first embodiment will be explained at this point. The second embodiment differs from the first embodiment substantially lent by the fact that the air conditioner 12 is mounted below the hat rack 76 hanging. For this, the air conditioner 12 is mounted directly to the parcel shelf 76, to a (not shown) body panel or to (not shown) body struts. The air guide 74 can be omitted entirely or greatly shortened, since the air can flow directly from the air conditioner 12 via corresponding inlet openings in the parcel shelf 76 in the vehicle interior 78.

FIG. 4 shows a flowchart of the air conditioning operation of the air conditioner 12 according to the first and second embodiments. The routine of FIG. 4 executed by the electronic control unit starts at step S100 when the air conditioner 12 is turned on manually. At step SIOL, it is determined whether the power plant 94 is still operating. The process does not proceed to step S102 until the query in step S101 is negative. In step S102, it is determined whether the user has selected an automatic standby mode via a selector switch or a corresponding programming of the air conditioner 12. If not, the process proceeds to step S103 where it is determined whether the user has manually selected standby air conditioning. If this is not the case, then the process proceeds to step S104, where it is determined whether the user has manually selected comfort climate control. If this is to be answered with "YES", the process proceeds to step S105, at which a comfort air-conditioning is performed. In this wellness air-conditioning the interior space 78 of the motor vehicle 10 is conditioned to a comfortable temperature (for example, 18 ⁰ C), by a selection of the various heating and cooling modes is taken by the electronic control unit. The subsequent step S106 determines that this feel-good air conditioning is automatically stopped when the power plant 94 is started. Accordingly, if it is determined in step S106 that the power plant 94 is not running yet, it is determined in S107 whether the air conditioner 12 has been turned off manually. For a manual shutdown - -

the process ends at step S112, otherwise the process returns to step S105. If the user has not selected feel-good conditioning in step S104, the process returns to step S110. If it has been determined in step S102 that an automatic standby air conditioning has been selected, then the process proceeds from there to step S108, where it is determined whether a comfortable air conditioning has been manually selected by the user. If so, then the process proceeds to step S105, where the well-being conditioning described above is performed. If it is determined in step S108 that the user has not selected feel-good air-conditioning, then the process proceeds to step S109 where the standby air conditioning according to the present invention is performed. In this standby air conditioning, the temperature in the internal space 78 is controlled to a standby set temperature (e.g., 25 ° C) other than the comfort temperature. This is realized by suitably selecting the electronic control unit from the described heating and cooling modes. If the outside temperature is high, then the ready set temperature is greater than the comfort temperature. If, however, the outside temperature is low, then the ready set temperature is lower than the comfort temperature. Thus, for example, at high outside temperature

Heating the interior 78 prevents and, if necessary, ensures a very fast reaching the comfort temperature, because the interior 78 is already "pre-cooled". After step S109, the process proceeds to step SH0, where it is checked whether the power plant 94 has been started. If so, then the process returns to step S100. Otherwise, the process proceeds to step S11, where it is determined whether the user has turned off the air conditioning manually - if "YES", then the process ends - -

at step S112 and if "NO", then the process returns to step S108.

The preferred operation of the air conditioning system 12 in practice is to select automatic standby air conditioning. If the drive unit 94 is operated, then the interior space 78 can be conditioned via the vehicle-optimized, very effective and specially designed air conditioning system 92. As soon as the drive unit 94 is switched off (and the occupants possibly leave the motor vehicle 10), the air conditioning system 12 starts the standby air conditioning, which cools the interior space to, for example, 25 ^° C. at a high outside temperature. This ready-to-operate air conditioning operation can be carried out with 12 liters of fuel without any problems for 12 days in continuous operation. The standby air conditioning operation is performed until the user selects well-being air conditioning just before driving, which then cools the interior 78 to, for example, 18 ° C. The comfort air conditioning is then carried out until the drive unit 94 is restarted.

Although it has been described above that the air conditioner 12 is only in the stand, i. is operated at standstill of the drive unit 94, this is only the preferred mode of operation and it is also possible to operate the air conditioner 12 during operation of the drive unit 94.

The features of the invention disclosed in the foregoing description, in the drawings and in the claims may be essential to the realization of the invention both individually and in any combination. ^ _

LIST OF REFERENCE NUMBERS

10 motor vehicle

12 air conditioning 14 fuel cell system

16 cooling circuit

18 reformers

20 fuel strands

22 fuel strand 24 oxidant strand

26 fuel cell stack

28 Cathodic airflow

30 Electric line

32 electric motor 34 battery

36 Electric heater

38 anode exhaust gas stream

40 mixing unit

42 afterburner 44 fuel strands

46 Oxidizing agent strand

48 mixing unit

50 cathode exhaust line

52 heat exchanger 54 exhaust outlet

56 compressor

58 capacitor

60 expansion organ

62 evaporator 64 blower

66 outside air line

68 adjusting device

70 air streams

72 adjusting device _

74 air duct

76 hat rack

78 vehicle interior

80 seat

82 air duct

84 air duct

86 blowers

88 air flow

90 air duct

92 Conventional air conditioning

94 drive unit

Claims

An air conditioning system (12) for a motor vehicle (10), comprising a fuel cell (26), characterized in that the air conditioning system (12) is adapted to be arranged in the trunk of the motor vehicle (10).

2. Motor vehicle (10) with an air conditioner (12), which has a fuel cell (26), characterized in that the air conditioner (12) in the trunk of the motor vehicle (10) is arranged.

3. Motor vehicle (10) according to claim 2, characterized in that the air conditioning system (12) seen in the vehicle longitudinal direction below a hat rack (76) of the motor vehicle (10) and is mounted suspended.