DE102015222978B4 - Baggage tractor and method of operating a baggage tractor - Google Patents

Abstract

A baggage tractor (100) for transporting baggage at an airport, comprising:
- A drive motor (104) for driving the baggage tractor (100);
- A battery device (108) for storing electrical energy;
- A fuel cell device (112) for providing electrical energy;
- A thermal device (114) for cooling the fuel cell device (112), the thermal device (114) comprising a heat transfer medium for heat transfer;
- A heat storage device (132) which is formed by a storage container (134) for receiving heat transfer medium serving as a heat storage medium, the volume and / or the mass of the heat transfer medium storable or stored as a heat storage medium in the storage container (134) being at least five times the volume and / or the mass which would be required to operate the baggage tractor (100) without the storage container (134).

Description

The present invention relates to a vehicle and a method for operating a vehicle. One such vehicle is a baggage tractor for transporting baggage at an airport.

Vehicles, in particular those with a heat storage device, and generally various concepts for operating fuel cells are known, for example, from the following publications: DE 101 07 596 B4 ; DE 102 58 707 A1 ; DE 103 49 630 A1 ; DE 101 42 923 A1 ; DE 11 2007 002 347 T5 .

The present invention is based on the object of providing a baggage tractor which is simple in construction and can be operated in an energy-efficient manner.

This object is achieved according to the invention by a baggage tractor according to claim 1.

Because the vehicle includes a heat storage device, by means of which heat can be stored in a heat transfer medium serving as a heat storage medium, the heat generated during operation of the motor vehicle, in particular during operation of the fuel cell device, can preferably be stored simply and efficiently for later use.

It can be advantageous if a vehicle interior of the vehicle can be heated by means of the thermal device.

In particular, it can be provided that heat from the fuel cell device is used to heat the vehicle interior, for example by supplying heat transfer medium heated in the fuel cell device to a heat exchanger for heating air to be supplied from the vehicle interior. It can be provided that the supply of heat transfer medium from the fuel cell device to the heat exchanger for heating air to be supplied to the vehicle interior takes place at least approximately without a time delay or with a time delay taking into account intermediate storage.

The thermal device and the heat storage device preferably together comprise a single medium circuit for the heat transfer medium.

It can be provided that the heat transfer medium is optionally a heat exchanger for heating the vehicle interior (heat exchanger for heating air to be supplied from the vehicle interior) and / or a cooler for releasing excess heat to the surroundings of the vehicle and / or a heat exchanger for removing heat from the fuel cell device and / or can be fed to the storage container.

In one embodiment of the invention it can be provided that the heat transfer medium can be guided in a medium circuit. In particular, it can be provided that the heat transfer medium can be fed in succession to any of the aforementioned components of the vehicle or, optionally, can also be guided past one or more of the components by means of one or more bypass lines.

The vehicle, in particular the thermal device, preferably comprises one or more valves in order to be able to control and / or regulate in a targeted manner which component of the vehicle can be supplied or is supplied with heat transfer medium. Furthermore, a volume flow and / or mass flow of the heat transfer medium to be supplied to the respective component can preferably be controlled and / or regulated.

It can be provided that a control device of the vehicle is provided for control and / or regulation. This control device is preferably designed and set up to carry out the steps and / or functions described.

It can be provided that the heat transfer medium is or comprises a liquid. For example, it can be provided that the heat transfer medium is a water-glycol mixture.

The heat transfer medium is preferably liquid over the entire operating range of the vehicle. In particular, it can be provided that the heat transfer medium is in the liquid state of aggregation at least between approximately -20 ° C. and approximately + 50 ° C., preferably at least between approximately -40 ° C. and + 80 ° C.

The heat transfer medium is preferably designed and / or selected such that only sensible heat can be and / or stored by means of the heat transfer medium when the vehicle is in operation.

The drive motor of the vehicle is preferably an electric motor.

It can be provided that the vehicle comprises an electrical heating element for heating a vehicle interior. The vehicle interior is by means of the electrical heating element preferably heatable using electrical energy from the fuel cell device and / or the battery device.

In particular, the electric heating element can be used to heat the vehicle interior in order to heat the vehicle interior when the heat stored by means of the heat storage device is no longer sufficient to heat the vehicle interior or when a comfortable interior temperature is to be accelerated.

In one embodiment of the invention it can be provided that the volume and / or the mass of the heat transfer medium storable or stored as a heat storage medium in the storage container is at least ten times the volume and / or the mass which would be required to operate the vehicle without the storage container.

The volume and / or the mass that is or would be required to operate the vehicle without the storage container is the volume and / or the mass that is required in a conventional cooler circuit for cooling the fuel cell device by dissipating heat to the vehicle interior and / or to the vehicle environment would be provided. Usually the volume in this case is at most approximately 10 I, for example at most approximately 5 I.

The total volume of the heat transfer medium when using a heat storage device according to the invention is, however, preferably at least about 30 I, in particular at least about 50 I, for example at least about 100 I. The total volume of the heat transfer medium when using a heat storage device according to the invention is at least five times the volume which would be provided in a conventional cooler circuit for cooling the fuel cell device by dissipating heat to the vehicle interior and / or to the vehicle environment.

The thermal device preferably comprises several heat exchangers.

In particular, it can be provided that a heat exchanger is arranged in the fuel cell device and / or assigned to the fuel cell device in order to be able to transfer waste heat from the fuel cell device to the heat transfer medium and to be able to dissipate it from the fuel cell device. This heat exchanger can be, for example, a liquid-liquid heat exchanger. Furthermore, it can be provided that this heat exchanger is formed by cooling channels integrated into the fuel cell device, through which the heat transfer medium can flow.

Another heat exchanger, in particular for heating the vehicle interior, is preferably an air-liquid heat exchanger.

Furthermore, a heat exchanger is preferably provided for emitting heat to the surroundings of the vehicle. This heat exchanger is preferably an air-liquid heat exchanger.

The present invention also relates to a method for operating a baggage tractor.

In this regard, the invention is based on the object of providing a method by means of which a baggage tractor can be operated in a simple and energy-efficient manner. This object is achieved according to the invention by a method according to claim 8.

The method according to the invention preferably has one or more of the features and / or advantages described in connection with the baggage tractor according to the invention.

The method according to the invention can preferably be carried out on the baggage tractor according to the invention.

Furthermore, the baggage tractor according to the invention is preferably suitable for carrying out the method according to the invention.

The heat stored in the heat transfer medium can preferably be used for preconditioning the vehicle, in particular the vehicle interior and / or the fuel cell device, in particular before the vehicle is put into operation, i.e. set in motion.

In particular, the preconditioning takes place before the fuel cell device and / or the drive motor is put into operation.

In one embodiment of the invention, it can be provided that the vehicle can be operated either in fuel mode or in battery mode. In the fuel operation, electrical energy required to drive the vehicle is provided by means of the fuel cell device using fuel. In battery operation, electrical energy previously stored in a battery device is provided for driving the vehicle.

Heat generated in fuel operation is preferably stored in battery operation for later use, in particular by the arranged in the storage tank and / or to be supplied to the storage tank heat transfer medium is heated.

The heat transfer medium arranged in the storage tank is preferably heated in that heated and / or heated heat transfer medium is supplied to the storage tank and cooler heat transfer medium is removed from the storage tank.

However, provision can also be made for two storage tanks to be provided, with heated heat transfer medium being supplied to one of the storage tanks in order to store heat and at the same time cooler heat transfer medium being removed from the further storage tank, for example the heat transfer medium supplied to the first storage tank, which then consists of a Circuit of the thermal device has been removed.

It can be provided that, in battery operation, the heated heat transfer medium arranged in the storage container is fed to a heat exchanger for heating a vehicle interior of the vehicle. In this way, in particular electrical energy can be saved, which would otherwise have to be used to heat the vehicle interior by means of the electrical heating element.

It can be advantageous if, before starting and / or for starting the fuel cell device, the heated heat transfer medium arranged in the storage container is fed to a heat exchanger of the fuel cell device. In this way, a cold start of the fuel cell device can in particular be simplified and / or optimized using the heat stored in the storage container. The fuel cell device is thereby particularly preheated in order to avoid undesired operation of the fuel cell device at low temperatures, which can lead to high wear and / or damage to the fuel cell device.

In fuel operation of the fuel cell device, electrical energy is preferably provided on the one hand for driving the vehicle by means of the drive motor. On the other hand, electrical energy for charging the battery device is provided in fuel operation.

The fuel cell device is in particular what is known as an on-board charging device.

The fuel cell device is preferably only in cyclical operation.

For example, in the case of a utility vehicle designed as a baggage tractor, it can be provided that the battery device comprises several lead-acid batteries. These lead-acid batteries are preferably very heavy, which increases the traction performance of the baggage tractor. In this way, a driving force can be transmitted to the road, preferably without slippage, in order ultimately to be able to reliably pull the trailer to be pulled with the items of luggage located thereon.

A baggage tractor preferably comprises a vehicle cabin which surrounds the interior of the vehicle.

For safety reasons, an interior heater must preferably be provided, in particular to avoid undesired fogging of the windows. The interior heating is preferably formed by the thermal device and / or a component of the thermal device.

In particular, when a utility vehicle designed as a baggage hauler is frequently on the road alternately on the one hand in the open air and on the other hand in a baggage handling hall in cold outside conditions, the windows can fog up. Efficient interior heating, in particular by means of the thermal device and / or an electrical heating element, for example an electrical PTC resistance heater, is indispensable here.

In particular when the battery device comprises lead batteries, these have long charging times due to the high capacities required. Stationary charging of the lead batteries is then often economically critical. The battery device is therefore preferably charged while the vehicle is in operation, in particular using the fuel cell device.

The heat storage device is preferably an enthalpy storage device for the intermediate storage of waste heat from fuel cells.

The heat stored in the heat accumulator can preferably be used continuously or partially continuously, in particular as required and / or independently of the operation of the fuel cell device, for heating the vehicle interior.

Furthermore, it can be provided that the heat stored in the heat accumulator can be used continuously or partially continuously, in particular as required and / or independently of a driving operation of the vehicle, to heat the vehicle interior and / or the fuel cell device. A significant influencing factor can be the insulation of the storage tank of the heat storage device (the enthalpy storage). With conventional, thermally insulated storage containers, however, heat loss can preferably be minimized in a simple manner.

Because the heat transfer medium is used to store heat, there is preferably no exergy loss which would result from a transfer of the heat from the heat transfer medium to a separate heat storage medium.

As an alternative or in addition to one or more lead-acid batteries, the battery device can comprise one or more lithium-ion batteries.

A storage capacity of the battery device is preferably at least approximately 5 kWh, for example 8 kWh.

A maximum electrical power of the fuel cell device is preferably at least approximately 15 kW, in particular at least approximately 20 kW.

The fuel cell device is preferably designed and / or selected in such a way that its thermal and / or electrical power is overdimensioned for normal and / or regular operation of the vehicle. For example, it can be provided that the fuel cell device is overdimensioned with regard to its thermal and / or electrical power by at least approximately 30%, for example at least approximately 50%, in particular at least approximately 100%.

Further preferred features and / or advantages of the invention are the subject of the following description and the graphic representation of an exemplary embodiment.

• 1 eine schematische perspektivische Darstellung eines Fahrzeugs, welches eine Brennstoffzellenvorrichtung und eine Batterievorrichtung zum Versorgen eines Elektromotors des Fahrzeugs mit elektrischer Energie sowie eine Wärmespeichervorrichtung zum Speichern von Brennstoffzellenabwärme und eine Thermovorrichtung umfasst; und
• 2 eine vergrößerte Darstellung der Thermovorrichtung des Fahrzeugs aus 1.

In the drawings show:

• 1 a schematic perspective illustration of a vehicle, which comprises a fuel cell device and a battery device for supplying an electric motor of the vehicle with electrical energy and a heat storage device for storing fuel cell waste heat and a thermal device; and
• 2 an enlarged view of the thermal device of the vehicle 1 .

Identical or functionally equivalent elements are provided with the same reference symbols in all figures.

One in the 1 and 2 The illustrated embodiment of a vehicle designated as a whole by 100 is, for example, a motor vehicle 102 . In particular, the vehicle is 100 a baggage tractor for transporting baggage at airports.

The vehicle 100 includes a drive motor 104 which in particular as an electric motor 106 is trained.

The vehicle also includes 100 a battery device 108 , by means of which electrical energy to drive the drive motor 104 can be provided.

In particular, the electrical power is from the battery device 108 by means of an inverter 110 of the vehicle 100 convertible so that this is used to drive the drive motor 104 is usable.

The vehicle 100 further comprises a fuel cell device 112 .

The fuel cell device 112 is used to generate electrical energy using fuel, such as hydrogen.

The fuel cell device 112 is used in particular to charge the battery device 108 .

In the operation of the fuel cell device 112 this generates heat which is emitted from the fuel cell device 112 must be discharged.

To this end, the vehicle includes 100 a thermal device 114 .

The thermal device 114 comprises one or more heat exchangers 116 , a pump 118 and a medium circuit 120 .

By means of the pump 118 is a heat transfer medium in the medium cycle 120 drivable, in particular to the one or more heat exchangers 116 manageable.

A heat exchanger 116 preferably serves to absorb waste heat from the fuel cell device 112 .

A further heat exchanger is also preferred 116 provided, by means of which a vehicle interior 122 of the vehicle 100 is heatable. In particular, this is done by means of the heat exchanger 116 Heat from one in the medium cycle 120 guided heat transfer medium can be transferred to air, which ultimately the vehicle interior 122 can be fed or is fed.

How further 2 can be seen, the thermal device 114 also one as a cooler 124 trained heat exchanger 116 include. About this cooler 124 In particular, excess heat can be given off to a vehicle environment.

The thermal device 114 preferably also comprises one or more bypass lines 126 , by means of which the heat transfer medium, if required, to one or more heat exchangers 116 Can be passed in order to ultimately only transport heat to those areas where it is actually needed.

One or more valves 128 the thermal device 114 which are in particular controllable and / or regulatable are preferably used to distribute the heat transfer medium flow to the individual components of the thermal device 114 and / or flowing past the same by means of the one or more bypass lines 126 .

The vehicle 100 can be operated in particular in a fuel operation. Here, fuel is used in the fuel cell device 112 implemented to generate electrical energy. The resulting heat is transferred to the medium cycle via the heat transfer medium 120 out of the fuel cell device 112 discharged. In particular, the dissipated heat can be used to heat the vehicle interior 122 be used.

The vehicle interior 122 can be heated in particular when the fuel cell device 112 is in operation.

When the fuel cell device 112 is not in operation and thus the battery device 108 to provide electrical energy to drive the drive motor 104 of the vehicle 100 is used, can preferably by means of a heating element 130 electrical power from the battery device 108 for heating the vehicle interior 122 be used. However, such use of the electrical energy reduces the energy needed to propel the vehicle 100 in the battery device 108 available electrical energy.

In terms of the most energy-efficient possible operation of the vehicle 100 is therefore a different type of heat supply for the vehicle interior 122 desirable.

The vehicle 100 For this purpose preferably comprises a heat storage device 132 , which is a storage container 134 includes.

The storage container 134 serves in particular to accommodate the heat transfer medium, which thus serves as a heat storage medium.

In particular, the storage container 134 into the medium circuit 120 involved.

In the operation of the fuel cell device 112 is preferably all in the medium cycle 120 arranged heat transfer medium heated.

It is preferably in the medium cycle 120 including the storage tank 134 available amount of heat transfer medium considerably larger than this without the use of a storage tank 134 would be the case.

A large amount of heat can thus be sensibly stored by means of the heat transfer medium by heating or heating the entire heat transfer medium.

Because the heat transfer medium serves as a heat storage medium, there is no need for inefficient heat transfer from the heat transfer medium to a separate heat storage medium.

The operation of the fuel cell device 112 Generated heat can thus be stored particularly efficiently in order to ultimately heat the vehicle interior in particular 122 to be used when the fuel cell device 112 is no longer in operation.

By means of the heat storage device 132 In particular, it can be ensured that the in the battery device 108 stored electrical energy as large as possible to drive the drive motor 104 is available.

• Wenn ein Ladezustand der Batterievorrichtung 108 beispielsweise 30 % beträgt und auf 80 % erhöht werden soll, so wird die Brennstoffzellenvorrichtung 112 mit einer elektrischen Leistung von ungefähr 20 kW für vorzugsweise ungefähr 20 Minuten in Betrieb genommen. Dabei werden beispielsweise 0,3 kg Wasserstoff verbraucht. Das Fahrzeug 100 kann dann ausgehend von dem Ladegrad von 80 % der Batterievorrichtung 108 für ungefähr 2 Stunden im batterieelektrischen Betrieb genutzt werden, bevor der Beladegrad erneut unter 30 % fällt.

The vehicle described above 100 is used, for example, as follows:

• When a state of charge of the battery device 108 is, for example, 30% and is to be increased to 80%, the fuel cell device becomes 112 put into operation with an electrical power of approximately 20 kW for preferably approximately 20 minutes. For example, 0.3 kg of hydrogen are consumed in this process. The vehicle 100 can then based on the 80% charge level of the battery device 108 can be used for about 2 hours in battery-electric operation before the loading level falls below 30% again.

In cold conditions, in particular in winter operation at, for example, approximately -10 ° C., the vehicle interior must be heated 122 unavoidable, on the one hand, a comfortable environment for a driver of the vehicle 100 to provide and on the other hand to an undesirable fogging of a window of the vehicle 100 to prevent.

The heating of the vehicle interior 122 can for example by means of the heating element 130 be done electrically. However, this reduces the length of time in which the battery device 108 to propel the vehicle 100 can be used before the loading level falls below the limit of, for example, 30%.

Therefore, the one for heating the vehicle interior is preferred 122 required heat by means of the heat storage device 132 provided.

The heat storage device 132 for this purpose comprises in particular an enthalpy storage device, which is preferably provided by the storage container filled with the heat transfer medium 134 is formed.

Depending on the means of the heat storage device 132 Stored amount of heat and depending on the actual heating requirement, it may be necessary that the heating element 130 is switched on at least when a degree of loading of the heat storage device 132 with heat no longer for heating the vehicle interior 122 sufficient.

In addition, the heating element 130 be used to a regeneration phase of the enthalpy storage (renewed storage of heat) after starting the fuel cell device 112 to bridge.

By using the heat storage device 132 can be the required average heating power of the electrical heating element 130 preferably be reduced by about 50%.

For example, the use of a storage container 134 with a storage volume of 60 l and a corresponding increase in the medium circuit 120 The volume flow of the heat transfer medium is sufficient to provide useful thermal energy of 16 kWh. This can be used in particular for brief heating of the vehicle interior 122 sufficient up to 25 ° C. Compared to the conventional design of a vehicle 100 without a heat storage device 132 this roughly doubles the available heating energy.

List of reference symbols

100

Vehicle / baggage tractor

102

Motor vehicle

104

Drive motor

106

Electric motor

108

Battery device

110

Inverter

112

Fuel cell device

114

Thermal device

116

Heat exchanger

118

pump

120

Medium circuit

122

Vehicle interior

124

cooler

126

Bypass line

128

Valve

130

Heating element

132

Heat storage device

134

Storage tank

Claims (12)

A baggage tractor (100) for transporting baggage at an airport, comprising: - A drive motor (104) for driving the baggage tractor (100); - A battery device (108) for storing electrical energy; - A fuel cell device (112) for providing electrical energy; - A thermal device (114) for cooling the fuel cell device (112), the thermal device (114) comprising a heat transfer medium for heat transfer; - A heat storage device (132), which is formed by a storage container (134) for receiving heat transfer medium serving as heat storage medium, the volume and / or the mass of the heat transfer medium storable or stored as heat storage medium in the storage container (134) being at least five times the volume and / or the mass which would be required to operate the baggage tractor (100) without the storage container (134). Baggage tractor (100) after Claim 1 , characterized in that a vehicle interior (122) of the luggage tractor (100) can be heated by means of the thermal device (114). Baggage tractor (100) according to one of the Claims 1 or 2 , characterized in that the thermal device (114) and the heat storage device (132) jointly comprise a single medium circuit (120) for the heat transfer medium. Baggage tractor (100) according to one of the Claims 2 or 3 , characterized in that the Heat transfer medium a heat exchanger (116) for heating the vehicle interior (122) and / or a cooler (124) for releasing excess heat to the surroundings of the vehicle and / or a heat exchanger (116) for dissipating heat from the fuel cell device (112) and / or can be fed to the storage container (134). Baggage tractor (100) according to one of the Claims 1 until 4th , characterized in that the heat transfer medium is a liquid. Baggage tractor (100) according to one of the Claims 1 until 5 , characterized in that the drive motor (104) is an electric motor (106). Baggage tractor (100) according to one of the Claims 1 until 6th , characterized in that the volume and / or the mass of the heat transfer medium storable or stored as a heat storage medium in the storage container (134) is at least ten times the volume and / or the mass required to operate the baggage tractor (100) without the storage container (134 ) would be required. A method of operating a baggage tractor (100) comprising: - Provision of electrical energy and heat by means of a fuel cell device (112); - Absorption of the heat by means of a heat transfer medium; - Storage of the heat in a storage container (134) by supplying the heated heat transfer medium to the storage container (134) and / or by storing the heated heat transfer medium in the storage container (134), the volume and / or the mass of the heat storage medium in the storage container (134) storable or stored heat transfer medium is at least five times the volume and / or the mass which would be required to operate the baggage tractor (100) without the storage container (134). Procedure according to Claim 8 , characterized in that the baggage tractor (100) can be operated in a fuel mode and in a battery mode, wherein in the fuel mode an electrical energy required to drive the baggage tractor (100) is provided by means of the fuel cell device (112) using fuel, and wherein in the battery operation is provided with electrical energy previously stored in a battery device (108) for driving the luggage tractor (100). Procedure according to Claim 9 , characterized in that heat generated in the fuel operation is stored for later use of the same in battery operation by heating the heat transfer medium arranged in the storage container (134) and / or to be supplied to the storage container (134). Method according to one of the Claims 9 or 10 , characterized in that, in battery operation, the heated heat transfer medium arranged in the storage container (134) is fed to a heat exchanger (116) for heating a vehicle interior (122) of the baggage tractor (100). Method according to one of the Claims 8 until 11 , characterized in that before starting and / or for starting the fuel cell device (112), the heated heat transfer medium arranged in the storage container (134) is fed to a heat exchanger (116) of the fuel cell device (112).

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