WO2015149138A1

WO2015149138A1 - Hydraugen powered vehicle

Info

Publication number: WO2015149138A1
Application number: PCT/BE2015/000012
Authority: WO
Inventors: Mark René Johan PECQUEUR
Original assignee: Blue Planet Hydrogen N.V.
Priority date: 2014-04-04
Filing date: 2015-04-02
Publication date: 2015-10-08
Also published as: BE1021828B1

Abstract

Vehicle (1) comprising an electric motor (for driving the vehicle and comprising a battery compartment, wherein a box is placed in the battery compartment (2') to supply electrical energy to the electric motor, whereby the box comprises a hydrogen tank (5), a combustion engine (6) and a generator (7), wherein the hydrogen tank is connected to the combustion engine for the purpose of supplying hydrogen as fuel for the combustion engine, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is provided in order to supply said electrical energy.

Description

HYDRAUGEN POWERED VEHICLE

The invention relates to a vehicle with an electric motor for driving the vehicle and with a battery compartment, wherein a box is placed in the battery compartment to supply electrical energy to the electric motor. The invention relates particularly here to an industrial electric vehicle such as an electric forklift truck.

Industrial vehicles such as forklift trucks are used to displace loads. These vehicles are typically used here to displace loads in a warehouse, or to transport them into and out of a warehouse. Because these industrial vehicles are used at least partially indoors in practice (in warehouses, storage spaces, commercial premises,...), these industrial vehicles usually take an electric form. The advantage of an industrial vehicle which takes an electric form is that it does not emit any harmful substances. A known alternative to electrical driving is a petrol or diesel-powered combustion engine. In practice however, in order to avoid contamination of indoor spaces, industrial vehicles which are optionally partially used indoors take an electric form (i.e. with an electric motor which provides directly or indirectly for driving of the vehicle).

Electric industrial vehicles therefore have a battery compartment in which in practice a battery is placed. Depending on the capacity of the battery and on the intensity of use of the industrial vehicle, the industrial vehicle with a charged battery can be used for a predetermined period of time. A heavy forklift truck (with a battery of a 80 V 930 AH and a lifting capacity of 8 tons) can be used intensively for two hours with a charged battery. After two hours of use the charged battery is empty and this battery must be recharged. Because charging a battery takes a relatively long time, and in order to make maximum use of the electric vehicle, electric vehicles are in practice provided with exchangeable batteries. This means that, when the battery of the electric vehicle is empty, the operator of the electric vehicle can remove the battery from the battery compartment and can place a charged battery in the battery compartment to replace the empty battery. The empty battery can then be charged without the electric vehicle being immobilized.

A drawback of the above described method is that replacing batteries is complex, time- consuming and risky. Batteries for electric vehicles such as forklift trucks will in practice weigh several hundred kilograms and even up to several tons, depending on the capacity of the forklift truck. The battery also often contains hazardous and aggressive chemical substances. Because of the high weight of the battery, the battery will have to be unloaded from the forklift truck by means of an external lifting device. A second forklift truck is often necessary in practice for the purpose of replacing the battery from a first forklift truck. When an empty battery is then lifted out of a forklift truck, or a charged battery placed in the forklift truck, this will have to take place very carefully so as not to damage the battery and/or forklift truck.

The invention has for its object to simplify the use of an electric vehicle. The invention provides for this purpose a vehicle with an electric motor for driving the vehicle and with a battery compartment, wherein a box is placed in the battery compartment to supply electrical energy to the electric motor, characterized in that the box comprises a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for the purpose of supplying hydrogen as fuel for a combustion engine, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is provided in order to supply said electrical energy.

In contrast to the placing of a battery in the battery compartment, a box is placed in the electric vehicle which generates electrical energy via a generator driven by a hydrogen-powered combustion engine. The whole system of hydrogen tank, combustion engine and generator is placed here in the box. That is, the whole system for generating the electrical energy fits inside the battery compartment. As a result no modifications need be made to the electric vehicle to enable placing of the box or to enable use of the system of the invention. In contrast to conventional petrol or diesel-powered combustion engines, hydrogen does not emit any harmful gases. Combustion of hydrogen is hereby highly suitable for use in indoor spaces. Tests have further demonstrated that the temperature at which the hydrogen combustion engine operates in the box is not critical. That is, no appreciable modifications have to be made in order to cool the combustion engine. This facilitates placing of the box according to the invention in an electric vehicle. Just as a battery, the box according to the invention has an autonomy dependent on the amount of hydrogen stored in the hydrogen tank. When the hydrogen tanks are empty the box, in contrast to a battery, does not have to be replaced. This is because hydrogen tanks can be filled in a very short time, this is in contrast to the charging of a battery. Exchanging the box by lifting the box out of the electric vehicle by means of an external lifting device and placing a new box in the battery compartment hereby becomes unnecessary. This considerably simplifies use of the electric vehicle according to the invention compared to an electric vehicle where a battery is placed in the battery compartment. Safety in respect of the user is also further improved because the user does not have to lift a heavy battery with hazardous substances into and out of the vehicle. Because the box is provided so as to be placed in the battery compartment, and because the box is provided for the purpose of supply the electrical energy to the vehicle, existing electric vehicles can also be provided with a box with a hydrogen tank, a combustion engine and a generator. This considerably increases the field of application of the invention, since the invention can be applied not only in new electric vehicles but also in existing electric vehicles. An existing electric vehicle can be converted here to an electric vehicle according to the invention without appreciable modifications by placing a box with hydrogen tank, combustion engine and generator in the battery compartment as replacement for the conventional battery.

The battery compartment preferably has an opening to outside the vehicle such that the box is replaceable via the opening. This feature specifies the field of application of the invention with the technical feature that the battery compartment has an opening to outside the vehicle. Electric industrial vehicles always have such an opening to outside the vehicle, this opening optionally be closed by a cover, in order to allow a user of the electric vehicle to replace the battery via an opening.

The box preferably has electrical output terminals which are compatible with electrical input terminals of the battery compartment, wherein the generator is connected electrically to the output terminals and wherein the electric motor is connected electrically to the input terminals. When electrical terminals are provided on the battery compartment which correspond to electrical terminals on the box, the box will automatically also be connected electrically to the vehicle when it is placed in the electric vehicle in order to supply the electrical energy. The electrical output terminals of the box are placed here in similar manner as the electrical output terminals of batteries which are compatible with the electric vehicle. This increases the convenience of placing of the box according to the invention in the electric vehicle.

The box preferably has a rectifier and an electrical buffer which are placed between generator and electric motor. Owing to the electrical buffer consumption peaks of the electric vehicle can be buffered by the box, whereby the output voltage of the box can be held more constant. The rectifier is provided to the purpose of supplying a predetermined direct voltage to the electric vehicle. The box preferably has a closable tank opening which is connected to the hydrogen tank and which is adapted for the purpose of refilling the hydrogen tank in the box from outside the box. The hydrogen tank can be refilled with hydrogen via the closable tank opening, whereby the box no longer has to be lifted out of the electric vehicle.

The tank opening is preferably accessible via the opening of the battery compartment. When the tank opening is accessible via the openings of the battery compartment, a user of the electric vehicle can reach the tank opening in very simple manner in order to refill the hydrogen tank. The box is not lifted out of the vehicle here, nor is the box displaced in the vehicle in order to access the tank opening.

The box preferably further has a heat exchanger for absorbing heat from the combustion engine and transporting means for transporting absorbed heat outside the box. The heat exchanger can be used here to cool the engine. Preferably however, the vehicle further comprises a heating element in a cab of the vehicle, wherein the transporting means are provided for the purpose of transporting the absorbed heat to the heating element. An electric vehicle, in particular an industrial electric vehicle, conventionally has no heating in the cab. The reason for this is that an electric vehicle generates hardly any heat as byproduct of the driving, and that heat must therefore be generated with electrical energy from the batteries. Such a system where heat is generated via electrical energy from the batteries would greatly detract from the autonomy of the electric vehicle, since heating means typically require much electric power. Electric vehicles are however often used outside, and even when they are used indoors this is typically in storage spaces or commercial premises which are not heated to any great extent. During cold periods it is often highly uncomfortable in the cab for an operator of a conventional electric vehicle (without heating elements). When the electric vehicle is converted to an electric vehicle according to the invention by placing of a box with a hydrogen tank, combustion engine and a generator, heating can be provided in the cab without detracting from the autonomy of the electric vehicle. Used for this purpose is heat (which is created as byproduct resulting from the combustion of hydrogen) which is absorbed via a heat exchanger and transported to the cabin. This considerably increases the comfort of the user of the electric vehicle according to the invention.

The transporting means are preferably formed as a liquid circuit in which a liquid can be circulated. A cooling liquid is then typically provided in the circuit here, the cooling liquid being known for absorbing heat in efficient manner in a first heat exchanger and relinquishing it again in a second heat exchanger.

The box preferably further comprises an electronic control which is provided so as to control at least one of the combustion engine and generator such that an output voltage of the box approximates a predetermined value. The predetermined value is preferably selected here such that it is substantially equal to the electrical output voltage supplied by a predetermined battery which is compatible with the electric vehicle. Via the electronic control the power supplied by combustion engine and generator is hereby configured to correspond to the electric power used by the vehicle.

The vehicle is preferably an industrial vehicle, and the vehicle is more preferably a forklift truck. It will be apparent from the above description that the problem to which the invention provides a solution occurs particularly in electric industrial vehicles, of which forklift trucks are the most common example.

The invention further relates to a box suitable for placing in an electric vehicle with an electric motor for driving the vehicle and with a battery compartment in which a box is placeable for the purpose of supplying electrical energy to the electric motor, and wherein the box has a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for the purpose of supplying the hydrogen as fuel for the combustion engine, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is provided so as to supply electrical energy to the vehicle. Via the box according to the invention an electric vehicle can be converted to an electric vehicle according to the invention (as described above). Particularly a battery of the electric industrial vehicle can be replaced by a box according to the invention with hydrogen tank, combustion engine and generator such that the electric vehicle obtains its energy from the box according to the invention. The invention further relates to a method for converting a vehicle with an electric motor for driving the vehicle, which vehicle has a battery compartment with electrical terminals which are connected to the electric motor for the purpose of supplying electrical energy to the electric motor, and wherein the method comprises of:

- removing a battery from a battery compartment of the vehicle;

- placing a box in a battery compartment, wherein the box comprises a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for supplying hydrogen as fuel therefor, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is connected electrically to output terminals of the box;

- connecting the output terminals of the box to the electrical terminals.

Via the method according to the invention an electric vehicle, in particular an electric industrial vehicle, can be converted to an electric vehicle according to the invention. This method can be applied to already existing electric vehicles currently running on batteries as well as to new electric vehicles.

The invention will be further described with reference to an exemplary embodiment shown in the drawing.

In the drawing:

figure 1 shows a forklift truck with replaceable battery;

figure 2 shows a diagram of a box according to an embodiment of the invention.

The same or similar elements are designated in the drawing with the same reference numerals.

Figure 1 shows a forklift truck 1 with a battery compartment 2' in which a battery in the form of a box 2 is conventionally placeable. Battery 2 can be lifted into and out of forklift truck 1, this being designated with arrow 3. Battery 2 can be provided for this purpose with channels 18 with which battery 2 can be placed into forklift truck 1 by means of a forklift truck or other lifting device. Battery 2 further has electrical terminals 4 which are compatible with electrical terminals on forklift truck 1 such that battery 2 can supply electrical energy to forklift truck 1. As alternative to the electrical terminals, the battery can be connected by means of a separate electrical conductor (not shown) to forklift truck 1. Forklift truck 1 has an electric motor for driving the forklift truck 1. Despite the fact that the invention can be applied particularly to forklift trucks 1 taking an electrical form, it will be apparent that other electric vehicles, in particular industrial electric vehicles, are likewise suitable for application of the invention. Any electric vehicle with a battery compartment, wherein the battery compartment has an opening for replacement of the battery and wherein the battery is periodically replaced during normal use of the electric vehicle, is in principle suitable for application of the invention. It will further be apparent here that the larger the battery 2 the more advantageous application of the invention becomes. Other electric vehicles for which the invention is applicable are electric excavators, electric transport machines, electric cranes and other industrial machines in electrical form with exchangeable battery. Mobile generators (which are typically seen as stationary industrial devices) can further also be provided with a box according to the invention.

An electric vehicle is defined in the context of the invention as a vehicle wherein an electric motor is directly or indirectly responsible for driving the vehicle. It will be apparent here that a direct electrical drive is a drive wherein the electric motor drives (for instance the wheels of) the forklift truck directly. An indirect electrical drive can for instance be formed by the electrical drive of a hydraulic system, the hydraulic system driving the wheels of the forklift truck via hydraulic motors .

Figure 2 shows a box 2, and shows in schematic manner how different elements are placed in box 2. In respect of shape and outer dimensions the box 2 corresponds to battery 2 of figure 1. Box 2, just as a battery, can hereby be placed in battery compartment 2' of the forklift truck. Box 2 of figure 2 shows an embodiment of the invention. By placing the box 2 in electric vehicle 1 as replacement for a battery the electric vehicle 1 can be converted to an electric vehicle according to the invention.

Box 2 comprises a hydrogen storage tank 5, a combustion engine 6 and a generator 7. Hydrogen storage tank 5 (also referred to as hydrogen tank) is provided here for the purpose of storing hydrogen. Hydrogen can be stored here as liquid or as gas depending on the type of storage medium used. Hydrogen storage tank 5 is connected via conduit 9 to motor 6 such that hydrogen from hydrogen storage tank 5 can be supplied as fuel to combustion engine 6. A pressure reducing valve (not shown) is typically placed here in conduit 9 so that the pressure of hydrogen from the tank to combustion engine 6 can be reduced. A valve 10 can be provided here at the position of hydrogen storage tank 5 for closing the conduit 9 such that supply of the hydrogen to motor 6 is stopped. The whole system in box 2, with the exception of hydrogen storage tank 5, is made hydrogen-free by stopping the motor 6 by closing the valve 10. Tests have shown that this increases the lifespan of motor 6 appreciably.

Combustion engine 6 has an output shaft which is connected mechanically to a rotor of an electric generator 7. The output shaft of engine 6 is connected mechanically for this purpose to the shaft of generator 7 via a connecting shaft 8 (wherein the rotor of the generator is mounted on the shaft of the generator).

Generator 7 is provided for the purpose of generating electrical energy when the rotor of generator 7 is driven by engine 6. Generators for generating electrical energy are generally known, wherein it is also known that such a generator can be configured to generate a direct voltage or an alternating voltage. Also known is how generators 7 can be wound in order to produce

predetermined output voltages. Because the skilled person is familiar with the selection and configuration of a generator 7 for the purpose of obtaining a predetermined output voltage, this is not discussed in detail in this description. Generator 7 is provided so as to supply a predetermined output voltage.

A rectifier is provided at the position of the output of generator 7. This rectifier can alternatively also be integrated into the generator. A buffer 12 can further be placed at the output of generator 7 as electrical buffer between generator 7 and electric vehicle 1. Peak loads of the electric vehicle can be absorbed via this buffer 12. Buffer 12 also makes recuperation of braking energy possible. The electrical buffer can be implemented in different ways, for instance as a capacitor, a battery or a flywheel which is coupled to an electric motor/generator (as known from KERS systems).

Box 2, and in particular the motor and the generator 7 of box 2, is configured such that the box can produce a predetermined output voltage and electrical output 13. The predetermined output voltage and the electrical output of box 2 corresponds to the battery conventionally placed in the electric vehicle. The electrical output 13 of box 2 is preferably formed similarly here to the electrical terminals 4 of the battery (see figure 1). This further facilitates placing of a box 2 according to the invention in an electric vehicle 1.

Box 2 is preferably further provided with an electronic control 19 which is coupled to at least one of the motor 6 and the generator 7. Electronic control 19 is preferably further provided for the purpose of measuring the output voltage 13 of box 2. The electronic control is configured here to control motor 6 and/or generator 7 so as to approximate the predetermined output voltage 13. In a practical example of a forklift truck 1 in which conventionally a battery 2 is placed with a voltage of 80 V at terminals 4, electronic control 19 will be configured such that the output voltage 13 of the box approximates 80 V. It will be apparent here to the skilled person that a battery, just as the box of the invention, will display a fluctuation around the predetermined ideal voltage (80 V). This fluctuation depends on, among other factors, the power drawn off from battery box 2 by the electric vehicle.

A closable tank opening 14 is preferably provided on box 2, which tank opening 14 is connected to hydrogen storage tank 5. Hydrogen storage tank 5 can be refilled via the closable tank opening 14. Refilling with hydrogen is known and no further information is therefore given about this in this description. Tank opening 14 is preferably placed on box 2 in a zone which is accessible via the battery compartment opening of electric vehicle 1. This allows refilling of hydrogen storage tank 5 in the box in simple manner without box 2 having to be lifted for this purpose out of electric vehicle 1.

Box 2 preferably further comprises a heat exchanger 20 which is suitable for absorbing heat from box 2 and transporting the heat outside the box 2. Preferably placed for this purpose on an outer side of the box is a second heat exchanger 21 which is provided for the purpose of generating heat, for instance by blowing air 15 through heat exchanger 21 , wherein an airflow can be created by a fan 16. First heat exchanger 20 and second heat exchanger 21 are here preferably placed in a circuit, wherein conduits 17 extend from inside the box 2 to the outside in order to transport heat. A cooling liquid can then flow through conduits 17 and heat exchangers 20 and 21 in order to transport heat. Cooling of the system in box 2 is on the one hand obtained by heat being relinquished from box 2 by means of first heat exchanger 20. This cooling is however found not to be essential in practice because the operating temperature at which box 2 can function is not critical. That is, box 2 can function optimally within a very wide temperature range. The great advantage will however be that heat becomes available outside box 2 without the autonomy of the electric vehicle being affected. This heat can be employed for instance to heat the cab of electric vehicle 1. Second heat exchanger 21 can be placed for this purpose in the cab. Alternatively, second heat exchanger 21 is placed in the box at a position such that the heat can be blown out of the box, for instance via an opening in the wall of the box.

Box 2 of figure 2 allows conversion of an electric vehicle 1. For this purpose the battery is lifted out of battery compartment 2' of the electric vehicle, box 2 (with dimensions substantially equal to the dimensions of the battery) is placed in battery compartment 2' and box 2 is connected electrically to vehicle 1 , preferably via the electrical terminals 4. Once box 2 according to the invention has been placed in electric vehicle 1 , this box 2 need in principle no longer be removed from electric vehicle 1 , since refilling with hydrogen is possible. As explained above, this considerably improves the convenience of use of electric vehicle 1. Existing electric vehicles can in this way be converted in simple manner.

The skilled person will appreciate that the above explanation and the shown figures are only examples of embodiments of the invention and that different alternative configurations are possible for the purpose of obtaining a box or vehicle according to the invention. The invention will therefore not be limited to the shown or described examples, but will be defined solely in the claims.

Claims

I . Vehicle comprising an electric motor for driving the vehicle and comprising a battery compartment, wherein a box is placed in the battery compartment to supply electrical energy to the electric motor, characterized in that the box comprises a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for the purpose of supplying hydrogen as fuel for the combustion engine, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is provided in order to supply said electrical energy.

2. Vehicle as claimed in claim 1 , wherein the battery compartment has an opening to outside the vehicle such that the box is replaceable via the opening.

3. Vehicle as claimed in claim 1 or 2, wherein the box has electrical output terminals which are compatible with electrical input terminals of the battery compartment, wherein the generator is connected electrically to the output terminals and wherein the electric motor is connected electrically to the input terminals.

4. Vehicle as claimed in claim 1 or 2, wherein the box further comprises a rectifier and electrical buffer which are placed between the generator and the electric motor.

5. Vehicle as claimed in any of the foregoing claims, wherein the box has a closable tank opening which is connected to the hydrogen tank and which is adapted for the purpose of refilling the hydrogen tank in the box from outside the box.

6. Vehicle as claimed in claim 2 and claim 5, wherein the tank opening is accessible via the opening of the battery compartment.

7. Vehicle as claimed in any of the foregoing claims, wherein the box further has a heat exchanger for absorbing heat from the combustion engine and has transporting means for transporting absorbed heat outside the box.

8. Vehicle as claimed in claim 6, wherein the vehicle further comprises a heating element in a cab of the vehicle, wherein the transporting means are provided for the purpose of transporting the absorbed heat to the heating element.

9. Vehicle as claimed in claim 6 or 7, wherein the transporting means are formed as a liquid circuit in which a liquid can be circulated.

10. Vehicle as claimed in any of the foregoing claims, wherein the box further comprises an electronic control which is provided so as to control at least one of the combustion engine and generator such that an output voltage of the box approximates a predetermined value.

I I . Vehicle as claimed in any of the foregoing claims, wherein the vehicle is an industrial vehicle.

12. Vehicle as claimed in any of the foregoing claims, wherein the vehicle is a forklift truck.

13. Box suitable for placing in a vehicle of any of the foregoing claims, wherein the box comprises a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for the purpose of supplying hydrogen as fuel for the combustion engine, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is provided so as to supply electrical energy to the vehicle.

14. Method for converting a vehicle with an electric motor for driving the vehicle, which vehicle further has a battery compartment with electrical terminals which are connected to the electric motor for the purpose of supplying electrical energy to the electric motor, the method comprising of:

removing a battery from a battery compartment of the vehicle;

placing a box in the battery compartment, wherein the box comprises a hydrogen tank, a combustion engine and a generator, wherein the hydrogen tank is connected to the combustion engine for supplying hydrogen as fuel therefor, and wherein an output shaft of the combustion engine is connected mechanically to the generator, which generator is connected electrically to output terminals of the box;

connecting the output terminals of the box to the electrical terminals.