AN ELECTRICALLY DRIVEN AUTOMOBILE WITH A POWER PACK AND RETROFIT THEREOF

Abstract

An electrically driven automobile with a power pack and retrofit thereof. An electric power pack in an electrically powered automobile is provided for retrofit where part of the batteries are substituted by a fuel cell system in order to extend the travelling range of the automobile.

Claims

1-12. (canceled)

13. A method of extending the range of an electrically powered automobile by retrofitting an electric power pack in the automobile, the power pack of the automobile, prior to retrofit, comprising a casing and batteries but no fuel cell inside the casing for providing power to the electrical motors that rotate the wheels of the automobile only by the batteries, the batteries of the power pack being dimensioned to provide power enough for electrically propelling the automobile over a minimum range of a distance of more than 100 km, wherein the method comprises retrofitting the power pack by either modifying the power pack of the automobile or by removing the power pack from the automobile and installing an exchange power pack into the automobile; wherein the retrofitted power pack has electrical connectors for delivering electrical power to the electrical engines; wherein a fuel tank is provided as part of the automobile separate from the retrofitted power pack; wherein the method, as part of the retrofit, comprises providing a fuel cell system inside the casing of the modified power pack or inside the casing of a similarly dimensioned retrofit casing of the exchange power pack, the fuel cell system being provided in addition to batteries inside the casing and being electrically connected to the batteries in the casing for charging the batteries inside the casing by the fuel cell system and for providing electrical power by the fuel cell for the electrical engines, wherein the method further comprises propelling the automobile after retrofit with a hybrid power system inside the casing, the hybrid power system comprising batteries inside the casing and the fuel cell system inside the casing; wherein the retrofitted power pack has fuel connectors for receiving fuel for the fuel cell through a fuel pipe from a fuel tank and coolant connectors for connecting to a cooling radiator of the automobile and for circulation of cooling liquid through the power pack; wherein the casing of the power pack after retrofit comprises a first compartment that contains the batteries and at least one further compartment (15, 16, 17) containing the fuel cell system with a thermally insulating wall between the first compartment and the at least one further compartment for thermally separating the first compartment from the at least one further compartment of fuel cell system by the first thermally insulating wall, wherein the at least one further compartment comprises at least two further compartments with thermally insulating walls for separating the at least two further compartments in the casing from each other by the further thermally insulating walls, wherein one of the further compartments contains the fuel cell and another compartment a power management system, which is an electronic control system for power management of the fuel cell and the batteries; wherein the fuel cell is a high temperature polymer electrolyte membrane HT-PEM fuel cell, wherein the retrofitted power pack contains a reformer for catalytic reaction of alcohol and water into syngas for the fuel cell; wherein the method comprises after retrofitting providing alcohol in the fuel tank, receiving the alcohol from the fuel tank by the power pack, using the reformer for catalytic reaction of an evaporated mix of the alcohol and water into syngas, and providing the syngas to the fuel cell, operating the fuel cell at a temperature in the range of 120-200° C.

14. The method according to claim 13, the method further comprising propelling the automobile by power from the power pack prior to the retrofitting during multiple discharge and charging cycles of the batteries.

15. The method according to claim 13, wherein the method comprises retrofitting the power pack of the automobile by removing more than half but not more than 80% of the batteries from the casing and installing the fuel cell system inside the casing as a replacement for the removed batteries in the space of the removed batteries.

16. The method according to claim 13, wherein a cooling circuit is provided inside the casing after retrofit and the method comprises adjusting the temperature of the fuel cell and adjusting the temperature of the batteries using the same cooling circuit by controlling flow of coolant from the cooling circuit through the fuel cell and separately controlling flow of coolant from the cooling circuit through the batteries.

17. The method according to claim 13, wherein the fuel cell system comprises a reformer as well as a reformer burner in thermal contact with the reformer for transfer of heat to a catalyser inside the reformer, wherein the reformer burner comprises a burner-chamber providing flue gas by burning anode waste gas or fuel or both, wherein, for insulating the other components, including the electronic control system, thermally against the radiated heat from the reformer burner and the reformer, a fourth compartment with the reformer and the reformer burner is provided and also insulated and thermally separated from the other compartments by a further thermally insulating and thermally separating wall.

18. An electrically driven automobile comprising a hybrid electric power pack, the power pack comprising a casing inside which batteries are provided as well as a fuel cell system, the fuel cell system at least comprising a fuel cell and a liquid cooling circuit for adjustment of the temperature of the fuel cell, wherein the batteries and the fuel cell system are electrically interconnected for recharging the batteries by the fuel cell system; wherein the casing comprises a first compartment that contains the batteries and at least one further compartment containing the fuel cell system, wherein a first thermally insulating wall is provided between the first compartment and the at least one further compartment, wherein the first thermally insulating wall is thermally separating the first compartment from the at least one further compartment, wherein the automobile comprises a fuel tank separate from the power pack; wherein the power pack has coolant connectors for connecting to a cooling radiator of the automobile and for circulation of cooling liquid through the power pack; the power pack has electrical connectors for delivering electrical power to the electrical engines and fuel connectors for receiving fuel for the fuel cell through a fuel pipe from the fuel tank; the power pack contains a reformer for catalytic reaction of alcohol and water into syngas for the fuel cell; the fuel cell is a high temperature polymer electrolyte membrane HT-PEM fuel cell, configured for operating at a temperature in the range of 120-200° C.; the at least one further compartment comprises at least two further compartments, wherein one of the compartments contains the fuel cell and another compartment an electronic control system for power management of the fuel cell and the batteries, wherein further thermally insulating walls are provided and thermally separating the at least two further compartments in the casing from each other.

19. The automobile according to claim 18, wherein the cooling circuit is configured for adjustment of the temperature of the fuel cell and adjustment of the temperature of the batteries by control of flow of coolant from the cooling circuit through the fuel cell and by separate control of flow of coolant through the battery.

20. The automobile according to claim 18, wherein the fuel cell system comprises a reformer as well as a reformer burner in thermal contact with the reformer for transfer of heat to a catalyser inside the reformer, wherein the reformer burner comprises a burner-chamber providing flue gas by burning anode waste gas or fuel or both, wherein, for insulating the other components including the electronic control system thermally against the radiated heat from the reformer burner and the reformer, a fourth compartment with the reformer and the reformer burner is provided and also insulated and thermally separated from the other compartments by a further thermally insulating and thermally separating wall.

Description

DESCRIPTION OF THE DRAWING

[0051] Embodiments of the invention will be described in the figures, wherein:

[0052] FIG. 1 illustrates a chassis of an automobile with a hybrid energy pack,

[0053] FIG. 2 illustrates the hybrid energy pack in greater detail.

DETAILED DESCRIPTION OF THE INVENTION

[0054] FIG. 1 illustrates a chassis 1 of a vehicle in the form of an automobile, where a power pack 30 is equipped with a fuel cell stack 6 and a battery 12.

[0055] FIG. 2 illustrates details of the power pack 30. The fuel cell system and the batteries 12 are contained in a box-shaped casing 13 with walls 19 forming bottom and top and sides to form an enclosure, preferably insulating enclosure. As best seen in FIG. 2, the casing 13 is held inside a frame 26. The frame 26 is configured such that the power pack 30 can be demounted from the automobile and substituted by a similar sized retrofit power pack 30.

[0056] The fuel cell system comprises a fuel cell stack 6, a combination 27 of the reformer 8 and corresponding reformer burner 28, and a temperature regulation system 11, including a cooling circuit 18. In addition, a power management system 10 is provided. Fuel is provided from a fuel tank 9. The fuel tank 9 is separate and remote from the casing 13 of the power pack 30 and feeds fuel to the power pack 30 through a fuel pipe 29. For example, the fuel tank 9 contains alcohol, optionally methanol, to which water is added prior to catalytic transformation in a reformer for providing it as hydrogen fuel to the fuel cell. However, in principle, it is also possible that the fuel tank 9 comprises hydrogen gas.

[0057] The battery 12 changes temperature during charging and discharging relatively to an idle state. The reformer 8 has to be heated by a reformer burner in order to convert the liquid fuel, for example methanol and water into syngas for providing hydrogen gas the fuel cell 6. This produces substantial amounts of heat.

[0058] As an example, in the reformer 8, the mix of methanol CH.sub.3OH and water H.sub.2O is catalytically converted into hydrogen gas H.sub.2 and CO.sub.2. Simplified, the methanol CH.sub.3OH is converted into 2H.sub.2 and CO, and the water molecule splits into H.sub.2 and O, where the oxygen is captures by the CO to produce CO.sub.2. The mix of H.sub.2 and CO.sub.2 is then supplied as so-called syngas to the anode side of the fuel cell, typically fuel cell stack 6. Air from the environment is drawn in through an air filter 4 and through air intake pipe 7 and supplied to the cathode side of the fuel cell 6 in order to provide the necessary oxygen for the reaction with the hydrogen to produce water, after hydrogen ions H+ have passed the membrane from the anode side to the cathode side.

[0059] Advantageously, the fuel cell 6 is a high temperature polymer electrolyte membrane (HT-PEM) fuel cell. Typically, high temperature fuel cells operate in the temperature range of 120-200° C., and thus are producing heat as well. For example, the fuel cell 6 operates at a temperature of 175° C. This operation temperature is held constant by a correspondingly adjusted flow of first coolant in a cooling circuit 18 through the fuel cell 6. For example, the temperature of the first coolant at the coolant inlet of the fuel cell 6 is in the range of 160° C. to 170° C.

[0060] In order to control the temperature of the individual components, the components are separated into compartments of the box 13. In a first compartment 14, the batteries 12 are provided. A separate compartment 15 is provided for the combined reformer 8 and burner 28. A third compartment 16 is for the fuel cell stack 6 and the temperature regulation system and the main components of the cooling circuit 18. A fourth compartment 17 houses the power management system 10.

[0061] Between the first compartments 14 with the battery 14 and the fuel cell system 6, 8, 11 a first insulating wall 21 is provided. This first insulating wall 21 insulates and thermally separates the battery 12 from the heat that is produced by the fuel cell system, including the fuel cell stack 6 and the reformer 8 and its burner 28. By thermally separating the compartments of the fuel cell system from the first compartment of the battery 12 by a first insulating wall 21, the temperature of the battery 12 and the fuel cell system 6, 8, 11 can be adjusted better and more precise than without the first insulating wall 21.

[0062] By regulating the flow from the cooling circuit 18 with respect to each of the heat-producing components 6, 8, 12, a thorough control is obtained for the system. Flow meters and valves as well as temperature gauges electronically, electrically and functionally connected to a controller allows a proper computerized management of the temperature of each of the components.

[0063] In order to even control the temperature of the fuel cell stack more precisely, a second insulating wall 22 is provided between the fuel cell stack and the reformer 8 with its burner 28. This is another advantageous feature, as it allows a precise adjustment and maintenance of the correct temperature of the fuel cell.

[0064] Electronics are influenced by high temperature and should be thermally protected. For this reason, a third insulating wall 23 is provided between the fourth compartment 17 with the electronic power management system 10 from the fuel cell system, including the third compartment 16 that houses the fuel cell stack 6 and the second compartment 15 that contains the reformer 8.

[0065] In order to remove heat from the fuel cell system, the coolant is flowing through a radiator 2, for example in the front of the vehicle, which is a common way of releasing thermal energy from the system. Some of the heat can be used for heating the cabin, which is regulated in a controller 5 for air condition and heating. However, the precise temperature of the fuel cell system 6, 8 and the battery 12 is controlled in a controller 20 for the temperature management, which also controls the flow of the coolant through the various components.

[0066] Advantageously, the fuel cell system comprises a startup heater 24 for providing thermal energy to raise the temperature of the fuel cell system to the correct temperature for power-producing operation.

[0067] For connection to the radiator 2 and for receiving fuel from the fuel tank 9, as well as delivering electrical power, the power pack has corresponding connectors 25.

REFERENCE NUMBERS

[0068] 1 Chassis [0069] 2 Radiator [0070] 3 Air exhaust [0071] 4 Air filter [0072] 5 Aircon and heat controller [0073] 6 Fuel cell stack [0074] 7 Air intake [0075] 8 Reformer [0076] 9 Fuel tank [0077] 10 Power management system [0078] 11 Temperature regulation system [0079] 12 Battery [0080] 13 Box-shaped casing [0081] 14 first compartment for the batteries 12, [0082] 15 second compartment for the combined reformer and burner 8, [0083] 16 third compartment for the fuel cell stack 6 [0084] 17 fourth compartment for the power management system 10 [0085] 18 cooling circuit [0086] 19 casing of box 13 [0087] 20 controller for temperature management [0088] 21 first insulating wall [0089] 22 second insulating wall [0090] 23 third insulating wall [0091] 24 startup heater [0092] 25 connectors [0093] 26 frame [0094] 27 combination of reformer 8 and reformer-burner 28 [0095] 28 reformer-burner [0096] 29 fuel pipe from tank 9 to power pack 30 [0097] 30 power Pack [0098] 31 wheels