WO2021058869A1

WO2021058869A1 - Internal combustion engines with flow batteries

Info

Publication number: WO2021058869A1
Application number: PCT/FI2020/050623
Authority: WO
Inventors: Guangrong ZOU
Original assignee: Teknologian Tutkimuskeskus Vtt Oy
Priority date: 2019-09-23
Filing date: 2020-09-23
Publication date: 2021-04-01
Also published as: FI128861B; FI20195800A1

Abstract

The invention concerns an arrangement for a power generating unit (10) and a method for providing a cooling medium to an internal combustion engine. The arrangement comprises an internal combustion engine (11) and a flow battery (12) having anode and cathode electrolyte circulation circuits (12A, 12B). The flow battery is electrically connected to the internal combustion engine and to an electrical power load (13). At least one cooling circuit (19A, 19B) for cooling said internal combustion engine and at least one of said electrolyte circuits (12A, 12B) are combined to circulate said electrolyte through said flow battery (12) and through said cooling circuit as a cooling medium for said internal combustion engine (11).

Description

TITLE OF THE INVENTION

INTERNAL COMBUSTION ENGINES WITH FLOW BATTERIES

BACKGROUND OF THE INVENTION

[0001] Most vehicles, land or waterborne, are powered by internal combustion engines (ICE). ICE’s will continue to play a key role in power plants, vehicles and vessels etc., also in the coming decades. This will happen in parallel with new technologies and the uptake of renewable resources, such as wind and solar energies. Hybrid solutions with ICE components have been developed and taken into use.

[0002] Redox flow batteries are electrochemical cells where chemical energy is provided by two chemical components dissolved in liquids contained within the system and separated by a membrane:

Ion exchange occurs through the membrane when electric current flows through the battery, while both liquids circulate in their own respective space. Cell voltage is chemically determined by the Nemst equation and ranges between 1 - 2.2 volts.

[0003] A flow battery may be used like a rechargeable battery. It has several advantages over conventional batteries, such as a flexible layout with separate power and energy components, long cycle life due to no solid-to-solid phase transitions, quick response times with rapid charging, and no harmful emissions, as the electrolyte is aqueous and inherently safe and non-flammable. Compared to solid-state rechargeable batteries, flow batteries can operate at much higher currents, but their energy densities are around 30 - 35% of solid state batteries and are thus comparatively less powerful.

[0004] The present invention is based on the idea of providing an internal combustion engine with a flow battery, and to integrate these into a compact and energy-efficient hybrid. SUMMARY OF THE INVENTION

[0005] According to the invention, the cooling system of an engine is combined with a flow battery system in a manner that the engine cooling fluid is used as flow battery electrolyte. In practice, both the anode and the cathode electrolytes may flow through the engine cooling system and form circuits where the necessary reservoirs of electrolytes and the cooling system of the engine are integrated. Thus, the space needed for the flow battery system is essentially saved, and much more electric power is available in the integrated engine- battery system, compared with separate layouts.

[0006] A novel approach to integrate internal combustion engines with flow batteries where the flows of the flow batteries are integrated into and operated also as the cooling circuits of the engine cooling systems. An integrated control unit is needed to further improve the performance of both the engine and flow battery systems, as a greener and more energy efficient solution to the future hybrid energy systems.

[0007] According to one aspect of the invention, an arrangement for a power generating unit is provided, where the arrangement comprises an internal combustion engine, a flow battery having anode and cathode electrolyte circulation circuits. The flow battery is electrically connected to the internal combustion engine and to an electrical power load. At least one cooling circuit for cooling the internal combustion engine and at least one of the electrolyte circuits are combined to circulate the electrolyte through the flow battery and through the cooling circuit as a cooling medium for the internal combustion engine.

[0008] One suitable type of flow batteries is the Vanadium redox flow (VRFB) battery, which voltage efficiency increases and the coulombic efficiency slightly decreases with temperature.

[0009] In some embodiments, the internal combustion engine may have a first and a second cooling circuit, wherein a first electrolyte circuit for an anode electrolyte is combined with the first cooling circuit and a second electrolyte circuit for a cathode electrolyte is combined with the second cooling circuit. [0010] In some embodiments, at least one electrolyte circuit may comprise a heat exchanger for cooling the electrolyte flowing from said internal combustion engine to said flow battery.

[0011] In some embodiments, at least one electrolyte circuit may comprise an electrolyte reservoir between the internal combustion engine and said flow battery.

[0012] In some embodiments, the inventive arrangement may further comprise a control unit, an engine control unit and a battery control unit, wherein the control unit provides control of at least the electrolyte temperature and the mass flow to the electrolyte circulation circuit, taking into account at least load and operating data which is received from the engine control unit and/or the battery control unit. The control unit may also provide simultaneous control of multiple engine control units and battery control units.

[0013] According to a second aspect of the invention, a method for providing a cooling medium to an internal combustion engine electrically connected to a flow battery and to an electrical power load is provided. At least one of the anode or cathode electrolyte circulation circuits of the flow battery is combined to a cooling circuit for cooling the internal combustion engine, and the electrolyte is circulated through the flow battery and through the cooling circuit as a cooling medium for the internal combustion engine.

[0014] The invention offers considerable advantages. It provides a novel approach to more compact layout of hybrid engine-flow battery systems, resulting in automated, integrated and energy efficient hybrid engine-flow battery systems. More durable and reliable engine-flow battery systems throughout their lifecycles are obtained, as well as green and more sustainable engine-flow-battery systems.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows one exemplary embodiment of an inventive power producing unit;

Fig. 2 shows another exemplary embodiment of an inventive power producing unit; Fig. 3 shows a control unit capable of supporting at least some embodiments of the present invention;

Fig. 4 shows an exemplary layout of a control system comprising an integrated control unit, an engine control unit, a battery control unit and a vehicle energy management system; and

Fig. 5 shows an exemplary a layout of a control system comprising more than one engine or battery systems.

EMBODIMENTS

[0015] In Fig. 1 is shown one embodiment of an exemplary 3MW power producing unit or power plant 10 which is operated according to the invention, and configured mainly for load peak shaving. An internal combustion engine 11 is producing AC power with a generator 14, which at least part of is rectified to DC power at 15 and connected across the poles of a load 13 and a flow battery 12. The flow battery 12 is provided with anode and cathode electrolyte circulation circuits 12A and 12B respectively, for circulating the respective electrolytes through the flow battery. Cooling circuits 19A, 19B for cooling the internal combustion engine and the electrolyte circuits 12A and 12B are combined to circulate the respective electrolytes as a cooling medium for the internal combustion engine through the cooling circuits 19 A, 19B. The amount of water in the cooling and electrolyte systems system may be a total of 1 m³, for example. The energy density may be in the region of 50 ~ 150 Wh/1.

[0016] Obviously, the cooling circuits 19A, 19B may be located in an integral cooling unit having two separate heat exchangers, or they may locate in separate cooling units. It is also clear that without leaving the inventive scope either one of the electrolyte circuits 12A or 12B may be connected to a cooling circuit 19A or 19B, while the other electrolyte circuit may be circulated conventionally.

[0017] The electrolyte circulation circuits 12A and 12B are in the exemplary power plant in Fig. 1 provided with circulation pumps 16A and 16B, a heat exchanger unit 17 to cool the heated electrolytes fed from the internal combustion engine, and reservoirs 18 A, 18B for intermediate storage of the electrolytes, before they are fed back to the flow battery 12.

[0018] During operation, the electrolyte liquids contained in the flow battery circulation systems 12A and 12B are pumped through the cooling circuits 19A and 19B of the engine 11. The engine waste heat generated during the combustion process is dissipated in one or several cooling units to the electrolyte liquids. Such cooling units may consist of cooling circuits 19A and 19B, which may be heat exchangers, for example. The temperature of the liquids then need to be controlled, possibly by an external cooling medium C in the heat exchanger 17, for the flow battery operation, and fed through the cells of the flow battery system.

[0019] A proper electrolyte choice for each application is naturally crucial for successful operation of the inventive power plant. However, such choices are made based on one hand on specific flow battery criteria, such as power efficiency, coulombic capacity, temperature dependence, and on the other hand on cooling medium criteria for the internal combustion engine, such as heat capacity, corrosion and scaling inhibiting capability, freezing point temperature, and so on. In each application these need to be considered case by case, and are therefore not a part of the invention as claimed.

[0020] In Fig. 2 is shown another embodiment of an exemplary 3MW power producing unit 20 which is operated according to the invention, and configured mainly for load balancing. In a similar fashion as in Fig. 1, an internal combustion engine 21 is producing AC power with a generator 24, which at least part of is rectified to DC power at 25 and connected across the poles of a load 23 and a flow battery 22. The flow battery 22 is provided with anode and cathode electrolyte circulation circuits 22A and 22B respectively, for circulating the respective electrolytes through the flow battery. Cooling circuits 29A, 29B for cooling the internal combustion engine and the electrolyte circuits 22A and 22B are combined to circulate the respective electrolytes as a cooling medium for the internal combustion engine through the cooling circuits 29A, 29B. [0021] As in Fig. 1, the electrolyte circulation circuits 22A and 22B are provided with circulation pumps 26 A and 26B. Here a heat exchanger is not used. Instead the intermediate storage reservoirs 28A, 28B have buffer electrolyte reservoirs 27A, 27B connected in parallel. These buffers 27A, 27B may be of considerable size and the electrolyte may be also be let to cool in them. For example, in the case of a ship or other vessel, the flow battery may have an almost unlimited capacity, if the ballast tanks and/or the sea chest of the ship are partially used as buffer reservoirs and are integrated in the power producing system.

[0022] Fig. 3 illustrates an example apparatus capable of supporting at least some embodiments of the present invention. Illustrated is device 300, which may comprise, for example, an integrated central control unit (ICCU) for a power producing system such as in Fig. 1 or Fig. 2. An integrated and automated control system is preferably implemented to control the mass flow and temperatures at different points of the various fluid-carrying circuits and pipes of the power producing unit or the power plant, to achieve the optimal performances of the cooling and electrolyte circulation systems integrated together. Both the engine and the flow battery need to be optimized based on the operating conditions and energy need.

[0023] For example, the uptake of flow batteries depends on their energy density and temperature.

[0024] Comprised in device 300 is processor 310, which may comprise, for example, a single- or multi-core processor wherein a single-core processor comprises one processing core and a multi-core processor comprises more than one processing core. Processor 310 may comprise, in general, a control device. Processor 310 may comprise more than one processor. Processor 310 may be a control device. A processing core may comprise, for example, a Cortex- A8 processing core manufactured by ARM Holdings or a Steamroller processing core designed by Advanced Micro Devices Corporation. Processor 310 may comprise at least one Qualcomm Snapdragon and/or Intel Atom processor. Processor 310 may comprise at least one application- specific integrated circuit, ASIC. Processor 310 may comprise at least one field-programmable gate array, FPGA. Processor 310 maybe means for performing method steps in device 300. Processor 310 may be configured, at least in part by computer instructions, to perform actions such as giving operating instructions and data processing.

[0025] A processor may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and/or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as control computer or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0026] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0027] Device 300 may comprise memory 320. Memory 320 may comprise random- access memory and/or permanent memory. Memory 320 may comprise at least one RAM chip. Memory 320 may comprise solid-state, magnetic, optical and/or holographic memory, for example. Memory 320 may be at least in part accessible to processor 310. Memory 320 may be at least in part comprised in processor 310. Memory 320 may be means for storing information. Memory 320 may comprise computer instructions that processor 310 is configured to execute. When computer instructions configured to cause processor 310 to perform certain actions are stored in memory 320, and device 300 overall is configured to run under the direction of processor 310 using computer instructions from memory 320, processor 310 and/or its at least one processing core may be considered to be configured to perform said certain actions. Memory 320 may be at least in part comprised in processor 310. Memory 320 may be at least in part external to device 300 but accessible to device 300.

[0028] Device 300 may comprise a transmitter 330. Device 300 may comprise a receiver 340. Transmitter 330 and receiver 340 may be configured to transmit and receive, respectively, information in accordance with at least one cellular or non- cellular standard. Transmitter 330 may comprise more than one transmitter. Receiver 340 may comprise more than one receiver. Transmitter 330 and/or receiver 340 may be configured to operate in accordance with global system for mobile communication, GSM, wideband code division multiple access, WCDMA, 5G, long term evolution, LTE, IS-95, wireless local area network, WLAN, Ethernet and/or worldwide interoperability for microwave access, WiMAX, standards, for example. The receiver may be used for wireless communication with external sensors, and the transmitter for wireless communication with various external actuators, operating units and drives necessary for adjusting the temperature, mass flow and other process parameters in the power producing units of Fig. 1 and Fig. 2.

[0029] Device 300 may comprise a communication interface 350 to send and receive information to and from the VEMS, the ECU, the BCU and other external sensors and actuators.

[0030] Device 300 may comprise user interface, UI, 360. UI 360 may comprise at least one of a display, a keyboard, a touchscreen, a vibrator arranged to signal to a user by causing device 300 to vibrate, a speaker and a microphone. A user may be able to operate device 300 via UI 360, for example to browse the Internet, to manage digital files stored in memory 320 or on a cloud accessible through the VEMS or via transmitter 330 and receiver 340. [0031] Device 300 may comprise or be arranged to accept a user identity module 370. User identity module 370 may comprise, for example, a subscriber identity module, SIM, card installable in device 300. A user identity module 370 may comprise information identifying a subscription of a user of device 300. A user identity module 370 may comprise cryptographic information usable to verify the identity of a user of device 300 and/or to facilitate encryption of communicated information and billing of the user of device 300 for communication effected via device 300.

[0032] Processor 310 may be furnished with a transmitter arranged to output information from processor 310, via electrical leads internal to device 300, to other devices comprised in device 300. Such a transmitter may comprise a serial bus transmitter arranged to, for example, output information via at least one electrical lead to memory 320 for storage therein. Alternatively to a serial bus, the transmitter may comprise a parallel bus transmitter. Likewise processor 310 may comprise a receiver arranged to receive information in processor 310, via electrical leads internal to device 300, from other devices comprised in device 300. Such a receiver may comprise a serial bus receiver arranged to, for example, receive information via at least one electrical lead from receiver 340 for processing in processor 310. Alternatively to a serial bus, the receiver may comprise a parallel bus receiver.

[0033] Processor 310, memory 320, transmitter 330, receiver 340, the wired interface 350, UI 360 and/or user identity module 370 may be interconnected by electrical leads internal to device 300 in a multitude of different ways. For example, each of the aforementioned devices may be separately connected to a master bus internal to device 300, to allow for the devices to exchange information. However, as the skilled person will appreciate, this is only one example and depending on the embodiment various ways of interconnecting at least two of the aforementioned devices may be selected without departing from the scope of the present disclosure.

[0034] Referring now to Fig. 4, an integrated central control unit ICCU, such as the one shown in Fig.3, is used to provide integrated control of e.g. temperatures and mass flow and to take into account information, such as load and operating conditions, received from the engine control unit (ECU), the battery control unit (BCU) and the vehicle energy management system (VEMS). An exemplary layout of such a system is shown in Fig.4. The system ensures that the internal combustion engine and flow battery can work under optimal load/operating conditions, as an integral part of the vehicle energy systems. The ICCU and BCU may be deployed as one unit. All or some of the units may be a part of the VEMS.

[0035] When more than one engine and/or battery systems are involved, as shown in Fig.5, the integrated central control unit ICCU works interactively with the VEMS and all the ECUs and BCUs. Depending on the requirements, operating conditions and plans of the vehicle energy systems, the internal combustion engines and flow batteries may work as engine-and-battery pairs or independently. In some cases, some flow battery (-ies) may operate without running the corresponding engine(s), where the engine cooling circuits function as the tanks storing the electrolyte of flow batteries. The control unit ICCU is used to provide integrated control of e.g. temperatures and mass flow and to take into account parameters such as operating conditions and load requirements, in order to optimize the operation of both the internal combustion engine and flow battery. For example, both the engine and the flow battery need to work at their proper temperature ranges in order to achieve their optimal performance.

[0036] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0037] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical value using a term such as, for example, about or substantially, the exact numerical value is also disclosed.

[0038] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[0039] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

[0040] While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

[0041] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", that is, a singular form, throughout this document does not exclude a plurality.

Claims

1. An arrangement for a power generating unit (10), said arrangement comprising an internal combustion engine (11), a flow battery (12) having anode and cathode electrolyte circulation circuits (12A, 12B), and which flow battery is electrically connected to said internal combustion engine and to an electrical power load (13), characterized by that at least one cooling circuit (19A, 19B) for cooling said internal combustion engine and at least one of said electrolyte circuits (12A, 12B) are combined to circulate said electrolyte through said flow battery (12) and through said cooling circuit as a cooling medium for said internal combustion engine (11).

2. An arrangement according to claim 1, wherein said internal combustion engine (11) has a first and a second cooling circuit (19A, 19B), wherein a first electrolyte circuit (12A) for an anode electrolyte is combined with said first cooling circuit (19A) and a second electrolyte circuit (12B) for a cathode electrolyte is combined with said second cooling circuit (19B).

3. An arrangement according to claim 1 or 2, wherein said at least one electrolyte circuit (12A, 12B) comprise a heat exchanger (17) for cooling the electrolyte flowing from said internal combustion engine (11) to said flow battery (12).

4. An arrangement according any of claims 1 - 3, wherein said at least one electrolyte circuit (22A, 22B) comprise an electrolyte reservoir (27A, 27B) between said internal combustion engine (21) and said flow battery (22).

5. An arrangement according any of claims 1 - 4, further comprising a control unit (ICCU), an engine control unit (ECU) and a battery control unit (BCU), wherein said control unit (ICCU) provides control of at least the electrolyte temperature and the mass flow to said at least one electrolyte circulation circuit (12A, 12B) taking into account at least load and operating data received from at least said engine control unit (ECU) and/or said battery control unit (BCU).

6. An arrangement according to claim 5, wherein said control unit (ICCU) provides simultaneous control of multiple engine control units and battery control units.

7. A method for providing a cooling medium to an internal combustion engine (11) electrically connected to a flow battery (12) and to an electrical power load (13), characterized by that at least one of the anode or cathode electrolyte circulation circuits (12A, 12B) of said flow battery is combined to a cooling circuit (19A, 19B) for cooling said internal combustion engine, and said electrolyte is circulated through said flow battery (12) and through said cooling circuit as a cooling medium for said internal combustion engine (11).

8. A method according to claim 7, wherein a first electrolyte in an anode electrolyte circuit (12A) is circulated in a first cooling circuit (19A) for said internal combustion engine and a second electrolyte in a cathode electrolyte circuit (12B) is circulated in a second cooling circuit (19B) for said internal combustion engine.

9. A method according to claim 7 or 8, wherein an electrolyte in said at least one electrolyte circuit (12A, 12B) is cooled between said internal combustion engine (11) and said flow battery (12) with a heat exchanger (17).

10. A method according any of claims 7- 9, wherein an electrolyte in said at least one electrolyte circuit (22 A, 22B) is let to cool between said internal combustion engine (21) and said flow battery (22) in an electrolyte reservoir (27A, 27B).

11. A method according any of claims 7 - 10, wherein at least the electrolyte temperature and the mass flow to said at least one electrolyte circulation circuit are controlled by a control unit (ICCU) taking into account at least load and operating data received from at least one engine control unit (ECU) and/or one battery control unit (BCU).