US20120286052A1

US20120286052A1 - System and method for solar-powered engine thermal management

Info

Publication number: US20120286052A1
Application number: US13/105,288
Authority: US
Inventors: Venkata Prasad Atluri; Kushal Narayanaswamy; Gerald A. Szekely, Jr.; Joel G. Toner; Paul M. Najt
Original assignee: GM Global Technology Operations LLC
Current assignee: GM Global Technology Operations LLC
Priority date: 2011-05-11
Filing date: 2011-05-11
Publication date: 2012-11-15
Also published as: CN102777307B; DE102012207729A1; DE102012207729B4; CN102777307A

Abstract

A system and method of engine thermal management. Energy may be received from a solar energy source electrically connected to a vehicle propulsion system. At least some of the energy from the solar energy source may be used to heat a component of the vehicle propulsion system. A control module may provide at least some of the energy from the solar energy source to a heater, for example, to heat a component of the vehicle propulsion system prior to starting the vehicle propulsion system. The heater may heat the vehicle propulsion system to temperatures within a predetermined range associated with optimal efficiency of the vehicle propulsion system.

Description

GOVERNMENT INTEREST STATEMENT

This invention was made in whole or in part with government support under grant number DE-EE0003379 awarded by the US Department of Energy. The government may have certain rights in the invention.

FIELD OF THE INVENTION

The present invention is related to methods and systems of efficient engine thermal management to improve fuel economy and engine performance of, for example, internal combustion, diesel, hybrid and extended range electric vehicles. In particular, the present invention is related to heating an engine coolant system using solar energy.

BACKGROUND

Vehicle propulsion or engine systems operate at optimal efficiency when the temperature of the engine system components is within a certain range. If a vehicle is parked for several hours in a cold environment, engine system components, which may include the engine coolant system, engine block, engine head, and other elements, may cool to temperatures below optimal operating temperature. When the temperature of the engine system components falls outside of specific temperature bounds, the engine system performance may be sub-optimal. When operating at a sub-optimum performance, a vehicle propulsion system may consume greater amounts of fuel than would be consumed under optimal temperature conditions. A cold engine system may, for example, expend roughly 33% of the fuel energy heating the engine coolant system or other engine system components. An engine system operating at temperatures outside of a given temperature range may also expel more exhaust emissions. Common exhaust emissions expelled include carbon monoxide (CO), unburned hydrocarbons (UHC), NOx and other particulate emissions that are harmful to the environment. Keeping engine system components within a certain temperature range results in better fuel economy and reduced emissions.
A method and system to keep vehicle propulsion system components within a given temperature range is needed.

SUMMARY

In some embodiments, energy may be received from a solar energy source electrically connected to a vehicle propulsion system. At least some of the energy from the solar energy source may be used to heat a component of the vehicle propulsion system. A control module may provide at least some of the energy from the solar energy source to a heater, for example, to heat a component of the vehicle propulsion system prior to starting the vehicle propulsion system. The heater may heat the vehicle propulsion system to temperatures within a predetermined range associated with optimal efficiency of the vehicle propulsion system.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

FIG. 1 is a schematic diagram of a vehicle and an engine thermal management method and system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a solar-powered engine thermal management method and system according to an embodiment of the present invention;

FIG. 3 is a chart defining different modes for allocating energy to different components in a vehicle according to an embodiment of the present invention;

FIG. 4 is a graph of cumulative fuel consumption of an engine system with respect to time according to an embodiment of the present invention;

FIG. 5 is a graph of coolant temperature of an engine system with respect to time according to an embodiment of the present invention; and

FIG. 6 is a flowchart of a method according to an embodiment of the present invention.

Reference numerals may be repeated among the drawings to indicate corresponding or analogous elements. Moreover, some of the blocks depicted in the drawings may be combined into a single function.

DETAILED DESCRIPTION

In the following description, various aspects of the present invention will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the present invention. However, it will also be apparent to one skilled in the art that the present invention may be practiced without the specific details presented herein. Furthermore, well known features may be omitted or simplified in order not to obscure the present invention.
Unless specifically stated otherwise, as apparent from the following discussions, it is appreciated that throughout the specification discussions utilizing terms such as “processing,” “computing,” “calculating,” “determining,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic computing device, that manipulates and/or transforms data represented as physical, such as electronic, quantities within the computing system's registers and/or memories into other data similarly represented as physical quantities within the computing system's memories, registers or other such information storage, transmission or display devices.
A vehicle propulsion or engine system may operate at optimal efficiency when it or certain propulsion or engine system components are within a specific range of elevated temperatures. An engine system operating at optimal efficiency may operate in warm engine calibration and advanced combustion modes resulting in increased fuel economy and reduced tailpipe emissions. Heating the engine system or its components to these temperatures may take time. The time it takes to heat the engine system may depend on many factors including the target temperatures for the specific type of engine system, available energy reserves in the vehicle, ambient temperature, weather conditions, the operational mode of the vehicle, for example, whether the vehicle is parked, stopped, driving, accelerating, etc. For example, it may take up to several minutes to properly heat an engine system. In one embodiment, the time required to heat the vehicle propulsion system components may be reduced by providing heat to the components while the vehicle is idle or parked.
Conventional systems do not provide energy to heat engine systems when the vehicle is not operating. The engine system therefore may only increase in temperature once the engine is started (and may not increase as much when the engine is idling). Accordingly, there may be a time delay after a vehicle has just been started (and possibly extended each time the vehicle idles) during which the engine system has not yet reached optimal temperatures. The engine system may operate with sub-optimal efficiency during these time delays by, for example, burning excess fuel, operating in cold engine calibration, operating in conventional inefficient combustion modes, and releasing increased emissions.
According to embodiments of the invention, a vehicle propulsion system may use solar power to power (e.g., heat) engine systems. Solar power energy (e.g., converted to electricity) may be captured via, for example, one or more (e.g., a network of) solar power cells mounted on or attached to the vehicle. The one or more solar power cells that may provide direct power to heating or engine systems, or power via an intermediate battery to the engine systems (e.g., by directing electricity to the engine systems). The solar power energy may be managed independently (or dependently) of other vehicle energy systems (e.g., the main vehicle battery) and may provide power or energy, for example, even when the vehicle engine is off. Since the solar power energy source does not depend on the main battery, the engine system may begin to be heated prior to starting the engine, for example, to be fully (or partially) pre-heated to optimal temperatures by the time the vehicle ignition is started. The energy to heat a component of the vehicle propulsion system may be stored in an energy storage system separately from, and distributed by a control module independently of, energy provided to start the vehicle propulsion system.
In one embodiment, an engine system may be pre-heated prior to starting the vehicle ignition for a time period which is less than, equal to, or greater than the time typically used to achieve the system's optimal functional temperature. In some embodiments, solar power sources may cause a longer time delay to pre-heat the engine system (e.g., one hour) than by using conventional vehicle energy sources (e.g., two to four minutes) and therefore a pre-heating process using solar power may be started earlier than one with non-solar power to account for the extra length of the time delay. In some embodiments, the heating from the solar power source may be deployed when the temperature of engine coolant, block, heads or other portions of the vehicle propulsion system drop below a predetermined temperature. The solar power source may therefore be operated to, and power may be distributed or provided to engine components to, ensure that the coolant, or other engine components, remains within a predetermined temperature range. In one embodiment, the solar power source provides energy to the engine system to maintain the engine coolant above 45-50 degrees Celsius (° C.). Other thresholds may be used.
Fluctuations in available energy from the solar power energy source may further affect the time used to heat the engine system by solar power. For example, on a sunny day, solar power energy sources may provide more energy and may take less time to power the engine system than on a cloudy day or during nighttime. In some embodiments, to account for such solar fluctuations, the solar energy sources may have an energy reserve or battery (e.g., separate from the main vehicle battery). The vehicle solar energy source may therefore harness solar energy from the sun during sunlight hours and may store the energy to power the engine system components at any time, regardless or currently available solar power (for example, during daytime as well as during nighttime).
Accordingly, a solar-powered engine system in a vehicle may be pre-heated, for example, to optimal temperatures (e.g., for optimal fuel economy, transition to warm engine calibration, and combustion efficiency, but other or different benefits may occur), prior to starting the vehicle engine. Accordingly, the conventional time delay during which the vehicle burns increased fuel, operates in cold engine calibration, is inhibited from employing advanced combustion modes, and produces increased tailpipe emissions may be eliminated or substantially reduced. In other embodiments, solar energy pre-heating need not occur prior to starting the vehicle engine.
FIG. 1 is a schematic diagram of a vehicle 100 and an engine thermal management system according to an embodiment of the present invention. Vehicle 100 (e.g. a locomotive device such as an automobile, truck, plane, boat, forklift, hybrid electric vehicle (HEV), extended range electric vehicle (EREV), non-locomotive device such as mining equipment, other engine-equipped machine, etc.) may include a main body 102 and optionally, an auxiliary power unit (APU) 104. Main body 102 may be a standard vehicle and may provide at least driving capabilities. Auxiliary power unit 104 may include an extension that may be integral to or detachable from main body 102.
Vehicle 100 may include one or more photovoltaic (solar) power source(s) 106. Photovoltaic sources 106 may include one or a plurality of interconnected individual solar cells, solar laminate film, solar cured glass, surface coatings, and/or other photovoltaic devices. Photovoltaic sources 106 may be mounted on either or both of main body 102 and auxiliary power unit 104. Photovoltaic sources 106 generating electricity may be mounted on any surface of vehicle 100 that may potentially be incident to the sun. For example, photovoltaic sources 106 may be mounted on the roof, trunk lid, front hood, bumpers, window guards, the windows themselves via photovoltaic glass laminate or cured glass, or any combination thereof, or other suitable surfaces. Photovoltaic sources 106 may be positioned at fixed positions or orientations or, using a device for tracking sun position, may be moved or movable, or rotated to a position or orientation to collect the maximal amount of solar power. Various arrangements may provide a total area of photovoltaic sources 106 of, for example, from approximately one square meter (e.g., mounted only on the roof) to about two to three square meters (e.g., mounted on the roof, trunk and hood). Other sizes may be used. Photovoltaic sources 106 may generate, for example, 200 to 400 watts of power for vehicle 100. The maximum amount of energy generated or power outputted by photovoltaic source 106 may be determined based on the amount of solar irradiance incident on a cell or other surface of photovoltaic source 106. The solar irradiance may be measured by photovoltaic source 106 or independently using one of several types of stand-alone pyranometers such as thermopile-based, silicon photodiode-based, or other type of measurement device.
Vehicle 100 may include a vehicle propulsion system or engine 108 providing mechanical power to move the vehicle and/or components of vehicle 100 (e.g., a fork lift). Engine 108 may be any hydrocarbon or hybrid hydrocarbon/electric fueled power source, such as an internal combustion engine, a diesel engine, a gasoline engine, a hydrocarbon portion of hybrid powertrain, electric motor (e.g., an AC electric motor or DC electric motor) or any combination thereof.
In one embodiment, engine 108 may operate in multiple engine calibrations including a cold engine calibration, a warm engine calibration, and/or other engine calibrations. Based on the engine calibration (e.g., warm engine calibration) engine 108 is operating in, a power control module, which may include a controller or processor and memory, or other device may use a set of engine maps corresponding to the calibration. The engine maps may be tables, matrices, or other forms of data used to control various engine functions. The power control module may use the engine maps to calculate or determine engine system parameters. The engine system parameters may include, for example, fuel-to-oxidizer ratio and other engine parameters.
Engine 108 may operate in a cold engine calibration below a certain threshold temperature required for transition to, for example, warm engine calibration or other engine calibration(s). In one embodiment, the threshold temperature to transfer to warm engine calibration may be 45-50° C., and the optimal temperature for warm engine calibration may be 90° C. Other thresholds may be used. Engine 108 may operate at optimal efficiency in warm calibration by burning less fuel and producing fewer emissions. By producing fewer emissions, the need for after-treatment devices may be reduced.
In one embodiment, engine 108 may operate in multiple combustion modes including a baseline conventional combustion mode (e.g., direct injection), a stratified or advanced combustion mode, and/or other combustion modes. An engine operating in baseline conventional combustion mode may produce more emissions and higher exhaust gas temperature, which heats up the coolant faster. An advanced combustion mode may be a homogeneous charge compression ignition (HCCI) mode. The HCCI combustion mode is advantageous because it emits low engine emissions while operating at high efficiency. The HCCI combustion mode employs functional characteristics of both gasoline and diesel engines. Similar to a gasoline or homogeneous charge spark ignition engine, fuel (e.g., gasoline) and oxidizer (e.g., air or other gases) may be combined. A spark-plug however may not be used to ignite the fuel/oxidizer mixture. Similar to gasoline engines, the emissions from HCCI combustion may be treated, or cleaned, using, for example, a three-way catalytic converter after-treatment device or other device(s) or method(s). Similar to a diesel engine, combustion of the fuel and oxidizer mixture may occur when the density and temperature of the mixture are raised to a certain level. Engine 108 when operating in an HCCI combustion mode may be difficult to control because combustion may occur in multiple locations within the cylinder when the fuel and oxidizer mixture reaches a certain temperature and pressure threshold. In order to more precisely control the combustion location and friction in engine 108, the temperature of engine 108 components must be maintained within a certain range. Engine 108 may therefore only operate efficiently in HCCI combustion mode when above a minimum temperature. As such, an engine 108 with HCCI functionality may operate in a conventional combustion mode when engine components are below a certain temperature. Engine 108 may then switch or transfer to an advanced combustion mode (e.g., HCCI) when the engine components, for example, the coolant, reach the threshold temperature. In one embodiment, the threshold temperature to switch to HCCI combustion mode may be 45-50° C. and the optimal temperature for HCCI combustion may be 90° C. Other thresholds may be used.
In one embodiment, engine 108 may operate in multiple combustion modes including a lean spark ignition direct injection (SIDI) combustion mode and other combustion modes. The benefits of lean SIDI combustion in comparison with conventional fuel injection based combustion modes include lower emissions and increased fuel economy. In a lean SIDI combustion mode highly pressurized fuel is injected into the combustion chamber where it mixes with oxidizer (e.g., oxygen or air). The fuel and oxidizer mix may then be ignited by a spark-plug. The fuel in an SIDI combustion system is injected at a much higher pressure than in a standard fuel injection system because the ratio of oxidizer to fuel is much higher in lean SIDI combustion than in baseline conventional combustion modes. The fuel in an SIDI combustion system, for example, is injected at 100-500 bar pressure or other pressure ranges. In order to raise the fuel to a higher pressure and minimize friction in engine 108, the engine components must be above a threshold temperature. In one embodiment, the threshold temperature to switch to lean SIDI combustion mode may be 45-50° C. and the optimal temperature for lean SIDI combustion may be 90° C. Other thresholds may be used.
In one embodiment, engine 108 may operate in multiple combustion modes including a premixed charge compression ignition (PCCI) combustion mode and other combustion modes. Similar to HCCI and lean SIDI combustion modes, the threshold temperature to switch from a conventional combustion mode to PCCI combustion mode may be 45-50° C. The optimal temperature for the PCCI combustion mode may be 90° C. Other thresholds may be used.
Vehicle 100 may include one or more energy storage system(s) (ESS) or batteries 110 and/or 112 for storing energy in main body 102 and/or auxiliary power unit 104. Battery 110 may include one or more low-voltage (e.g., 12 volt) batteries and battery 112 may include one or more high-voltage (e.g., 300 volts or greater) batteries. In some embodiments, low-voltage battery 110 may be used for relatively low-power tasks, for example, operating windshield wiper motors, power seats, or power door locks, powering a starter for an internal combustion engine, powering an after-treatment system 114, and/or heating an engine system 108. In some embodiments, high-voltage battery 112 may be used for either or both low or high-power tasks, where high-power tasks may include, for example, heating the engine system 108, including the coolant, engine head and engine block, powering the traction motors (if included) of vehicle 100 and propelling vehicle 100.
Photovoltaic sources 106 may be electrically connected to charge or store energy (e.g., electricity) generated thereby in either or both of low-voltage and/or high- voltage batteries 110, 112. Low-voltage battery 110 may be charged over a range of temperatures of from, for example, −20° C. to 50° C. The voltage used to charge low-voltage battery 110 may exceed the storage voltage of, for example, 12 volts. In one embodiment, the charging voltage of a lead-acid battery over this temperature range may be from approximately 13.5 to 16.5 volts. To charge high voltage battery 112, a plurality of interconnected photovoltaic sources 106 may be connected to a DC-DC converter to increase the voltage, for example, to about 300 volts. To charge both low and high- voltage batteries 110, 112, a step-down DC-DC converter may be used to reduce voltages to additionally charge low-voltage battery 110. In yet another embodiment, photovoltaic sources 106 may be connected to form at least two separate arrays with one generating power to high-voltage battery 112 at high-voltage battery-charging voltages and a second generating power to low-voltage battery 110 at low-voltage battery-charging voltages. Any suitable configuration of photovoltaic or solar material or cells may be used, for example, in combination with a DC-DC converter to increase charging voltage or a step-down DC-DC converter to decrease charging voltage, to achieve any target charging voltage. In some embodiments, photovoltaic sources 106 may charge low and high- voltage batteries 110, 112 equally, or one before the other, for example, only charging low-voltage battery 110 after high-voltage battery 112 is fully charged or vice versa.
Vehicle 100 may include an after-treatment (A/T) system 114. After-treatment system 114 may reduce undesirable exhaust emissions for example including NOx and particulate emissions.
FIG. 2 is a schematic diagram of a solar-powered engine thermal management system 200 according to an embodiment of the present invention.
System 200 may include a vehicle 202 (e.g., vehicle 100 of FIG. 1) having a vehicle propulsion or engine system 204. Vehicle 202 may include or have mounted to it photovoltaic (solar) electric power sources 206 (e.g., photovoltaic sources 106 of FIG. 1), such as, an array of solar energy cells and/or laminate. Vehicle 202 may include one or more high-voltage batteries 208 (e.g., high-voltage battery 112 of FIG. 1), one or more low-voltage batteries 210 (e.g., low-voltage battery 110 of FIG. 1) and/or one or more auxiliary power modules (APM) 214. Auxiliary power module 214 may be a step-up or step-down voltage converter.
A power control module 212 may control the allocation of energy (e.g. in the form of electricity) from photovoltaic sources 206 to each of vehicle 202 components (e.g., engine system 204). Power control module 212 may use a current measuring element 218 to measure the electric power output of photovoltaic sources 206 to determine the power adjustment necessary to charge or power each of vehicle 202 components. Power control module 212 may use DC- DC converters 220, 222 to adjust (e.g., increase or decrease) the voltage output of photovoltaic sources 206.
Power control module 212 may transfer energy (e.g. in the form of electricity) from photovoltaic sources 206 to high-voltage battery 208 (e.g., and/or APM 214) at the correct high-voltage battery charging voltage, for example, via DC-DC converter 222 and to low-voltage battery 210 at the low-voltage battery charging voltage, for example, via DC-DC converter 220. Energy may be transferred to batteries 208, 210 and/or APM 214 independently or, alternatively, first to high-voltage battery 208 and/or APM 214 and, upon saturating the storage capacity or reaching an above threshold amount of stored energy, subsequently transferred to low-voltage battery 210 (or vice versa). Current measuring element 218 may be used to measure current or electricity output from the photovoltaic sources 206 to determine the available electricity from solar power for distribution. Power control module 212 may also transfer electric energy (e.g. in the form of electricity) from photovoltaic sources 206 (e.g., either directly or via an intermediate storage component, such as, low-voltage battery 210) to engine system 204 components including one or more heater(s) 224 and/or other components of engine system 204. The one or more heater(s) 224 and/or other components each may heat a component of the engine system 204 such as coolant system 226 (which includes coolant 265), coolant 256, engine block 228, engine cylinders 230, or other engine system component. Power control module 212 may adjust voltage or current output to each of the vehicle propulsion system components according to the component's specific system standards (e.g., and according to different modes in FIG. 3), for example, via DC-DC converter 220 and may split output among engine system components, for example, via pulse-width modulation (PWM) device 232.
Power control module 212 may include a controller or processor 234 and memory 236. Processor 234 may issue control signals to (or directly) divert energy (e.g. in the form of electricity) to vehicle 202 components via one or more switches 238 and 240. In one example, switch 238 may distribute energy to after treatment system 254 or after treatment blower motor 216 (e.g., in actuated position (L1)), to the one or more heater(s) 224 (e.g., in actuated position (L2)), or to low-voltage battery 210 (e.g., in actuated position (L3)). Switch 240 may distribute energy from low-voltage battery 210 to after treatment system 254 or after treatment blower motor 216 (e.g., in actuated position (S2)) or to one or more heater(s) 224 (e.g., in actuated position (S3)). Heater 224 may be a heat exchanger, heating coil, heating device, heater or other device. Heater 224 may be used to transfer heat to coolant 256, coolant system 226, engine block 228, engine cylinders 230, or other engine system 204 components. Other switches or arrangements of switches may be used to transfer energy between any components in vehicle 202. Power control module 212 may be part of another engine system, such as an engine or vehicle computer system.
Controller or processor 234 may be, for example, one or more central processing unit(s) (CPU), a chip or any suitable computing or computational device. Processor 234 may include multiple processors, and may include general purpose processors and/or dedicated processors. Processor 234 may execute code or instructions, for example stored in memory 236 or long term storage 250, to carry out embodiments of the present invention.
Memory 236 may be or may include, for example, a Random Access Memory (RAM), a read only memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM (SD-RAM), a double data rate (DDR) memory chip, a Flash memory, a volatile memory, a non-volatile memory, a cache memory, a buffer, a short term memory unit, a long term memory unit, or other suitable memory units or storage units. Memory 236 may be or may include multiple memory units.
Long term storage 250 may be or may include, for example, a hard disk drive, a floppy disk drive, a Compact Disk (CD) drive, a CD-Recordable (CD-R) drive, and may include multiple or a combination of such units.
Power control module 212 may input information to determine (e.g., at processor 234) the appropriate amount of energy to transfer to engine system 204 to heat coolant system 226 within the optimal temperature range. Information may include data on conditions that affect the optimal amount of energy, power, or electricity to distribute or allocate to heater 224, coolant 256, coolant system 226, engine block 228, engine cylinders 230 and/or other engine system components to achieve the optimal temperature. Information may include, for example, voltage of one or more energy sources (Vb) (e.g., low-voltage battery 210), output current of photovoltaic source 206 (Ip), voltage of photovoltaic source 206 (Vp), ambient temperature (Ta), cabin temperature (Tc), after-treatment device bed temperature (Tbed), minimum power to operate power control module 212 (5 Volts), and/or vehicle mode (e.g., parked mode, driving mode) (Veh. Status). Information may include additional or different conditions.
Vehicle 202 may include internal devices, such as, an internal computer, processor 234 and memory 236, temperature, voltage and/or current sensors, and/or switches 238, 240 activated by predefined environmental conditions, for example, to store, retrieve or generate information, such as, Vb, Ip, Vp, Tc, and min. power. Vehicle 202 may also include a communication module 242 to communicate with external devices to retrieve or generate information, such as, Ta and Veh. Status. External devices may include a vehicle telemetrics source 244 such as, a global positioning system (GPS), a weather service source 246 providing information related to weather, terrain, altitude, or other environmental information, and a mobile computing device 248, such as, a mobile computer, a smart phone, a tablet computer, a personal digital assistant (PDA), etc., which may have a wireless network or cellular network connection to retrieve temperature, weather, geographic or environmental condition information from external devices or servers. Alternatively, any or all of the information may be obtained by devices internal to vehicle 202 or external to vehicle 202.
Power control module 212 may use information to select one or more modes defining where the energy from photovoltaic sources 206 is transferred. In one example, power control module 212 may transfer energy according to modes, for example, as defined in FIG. 3. Power control module 212 may provide energy by providing a current at a voltage (to result in a certain power level), which may be predetermined according to the voltage of the energy source (e.g., high-voltage battery 208, APM 214 or low-voltage battery 210).
FIG. 3 is a chart defining relationships between a plurality of different energy modes 304 for allocating energy to different components in a vehicle (e.g., vehicle 100 of FIG. 1) and a plurality of conditions 300 according to an embodiment of the present invention. When conditions or combination of conditions in a set of conditions 300 are detected, a control module may select a corresponding mode 304 for operation. Conditions 300 may include, for example, vehicle driving status or modes (e.g., if the vehicle is in park (0) or drive (1)), solar power (e.g., if there is light from the sun (1) or moon (0)), if a measured temperature is greater than, less than, or equal to a reference temperature (Tref), a coolant reference temperature (Tcoolant), and available battery voltage (e.g., if the voltage of one or more energy sources (Vb) such as low-voltage battery 210 of FIG. 2 is within a maximum, mid, or minimum voltage range). The measured temperature may be, for example, a cabin temperature (Tc), current temperature of the engine system 204, current coolant temperature (Tcoolant) when the vehicle is operating, etc. The reference temperature (Tref) may be the optimal temperature (or temperature range) for the engine system 204, coolant system 226, or after-treatment light-off temperature. The reference temperature (Tref) may also be equal to the difference between the ambient temperature (Ta) and the cabin temperature (Tc) (Tref=Ta−Tc). The coolant reference temperature (Tcoolant) may be the optimal temperature (or temperature range) for the coolant 256, coolant system 226, or other engine system component.
Each one of the plurality of energy modes 304 may correspond to a set of switch positions 302 and energy allocations 306. Energy allocations 306 may define the amount or percentage of energy (e.g., electricity) generated at a solar energy source to be allocated to different components of the vehicle. The energy may be distributed directly from the solar energy source (e.g., photovoltaic sources 106 of FIG. 1) or via an intermediate energy storage system (e.g., low-voltage battery 110 of FIG. 1). The components in the example in FIG. 3 are blower motor (X) (e.g., after treatment blower motor 216 of FIG. 2), battery (Y) (e.g., low-voltage battery 210 of FIG. 2), one or more after treatment system components (e.g., after treatment system 254 of FIG. 2), and one or more engine system components (e.g., engine system heater 224 of FIG. 2), although other components may be used. Energy modes 304 in the example in FIG. 3 include “Sleep 1” (e.g., 0% energy allocated to components during drive mode), “Sleep 2” (e.g., 0% energy allocated to components during park mode), “Blower ON 1” (e.g., 100% energy allocated to the blower), “Blower ON 2” (e.g., 80% energy allocated to the blower and 20% energy allocated to the battery), “Blower ON 3” (e.g., 40% energy allocated to the blower, 40% energy allocated to the battery and 20% energy allocated to one or more engine system component(s)), “Trickle Charge” (e.g., 60% energy allocated to the battery), “Bulk Charge” (e.g., 100% energy allocated to the battery), “After-Treatment” (e.g., 100% energy allocated to the after-treatment component(s) or associated parts), “Engine Thermal Management” (e.g., 100% energy allocated to the engine system component(s) or associated parts, for example, heater, heating exchanger, heating coil or other device to heat the engine coolant system or other engine system component(s)), “Engine Thermal Management+After Treatment” (e.g., 50% energy allocated to the engine system component(s) or associated parts, such as, heater, heating exchanger, heating coil, or other device to heat the coolant system or other engine system component(s) and 50% energy allocated to after-treatment system component(s) or associated parts), although other modes may be used. A power control module (e.g., power control module 212 of FIG. 2) may store these relationships between conditions 300 and the energy allocations 306 for energy modes 304, for example, in a memory unit (e.g., memory 230 of FIG. 2). Other or different modes may be used, and controlling systems and allocating power may be done without the use of modes.
The power control module may use a pulse-width modulation (PWM) device (e.g., PWM device 232 of FIG. 2) to divide or shunt electric energy from the solar energy source in different proportions among each of the different components based on conditions 300, for example, according to energy allocations 306.
In one embodiment of the present invention, power control module 212 may use energy from a low-voltage energy storage system (ESS) 210 (e.g., low-voltage battery 110 of FIG. 1) to provide relatively low-voltage energy to one or more heater(s) 224 to achieve optimal temperatures over a relatively longer time delay (e.g., 20-30 minutes). Power control module 212 may also use energy from a high-voltage battery 208 (e.g., high-voltage battery 112 of FIG. 1) to provide relatively high-voltage energy to heater 224 to achieve optimal temperatures over a relatively shorter time delay (e.g., 2-3 minutes).
In some embodiments, power control module 212 may use solar power energy from a solar energy source to fully or partially power heater 224. Power control module 212 may retrieve solar energy from photovoltaic (solar energy) sources 206, for example, stored in low-voltage energy storage system 210.
Power control module 212 may be in communication with a vehicle telemetrics source 244 and/or a mobile device 248, such as, a smart phone, to retrieve information to allocate power or generate a schedule or timeline for pre-heating engine system 204 or its components.
In some embodiments, a user or vehicle (with one or more associated users) may have a driving schedule (e.g., expected times when the user typically drives, such as, before and after work during the user's weekday commute, before and after meeting times for clubs or sport practices on the weekends, etc.), for example, stored in vehicle telemetrics source 244 or mobile device 248, or in another unit such as module 212. Power control module 212 may use the driving schedule to activate heater 224 to pre-heat engine system 204 components (e.g., coolant system 226, engine block 228, etc.) to optimal temperatures by the times that engine 204 is expected to be started. The user may be alerted that the engine system has begun pre-heating and/or that pre-heating is complete, for example, via an alert or alarm on their mobile device 248. The user may verify (or ignore) the prompt to initiate, continue, or not cancel pre-heating engine system 204 or, conversely, may reject (or ignore) the prompt to stop, cancel or not initiate pre-heating engine system 204. In another embodiment, a user may have a control button, for example, a virtual button on mobile device 248, a physical button in the vehicle, or a partial turning of an ignition key to initiate pre-heating engine system 204.
In some embodiments, power control module 212 may use weather information (e.g., temperature, clouds, time of sunrise/sunset, etc., provided by vehicle telemetrics source 244 or mobile device 248) to determine if pre-heating should be done and/or an amount of energy to allocate to pre-heat engine system 204. In some embodiments, if the weather information indicates future temperature fluctuations, power control module 212 may compensate for such weather changes by likewise changing the energy allocated to heater 224 to maintain engine temperature within the optimal range. Power control module 212 may alter the energy allocated to heater 224 prior to the expected future weather changes, for example, by an amount of time estimated to take heater 224 to achieve the expected temperature compensation. In some embodiments where power control module 212 uses energy from photovoltaic sources 206, power control module 212 may provide information related to the geographical location of the vehicle and may receive a sunlight schedule indicating measures of predicted future sunlight available to the vehicle over time based on the geographical location of the vehicle. Power control module 212 may change the amount of energy from photovoltaic sources 206 reserved for engine system 204 based on the sunlight schedule. In one example, if the sunlight schedule predicts clouds or a decrease in the future amount of available sunlight, power control module 212 may reserve an increased or maximum amount of current solar energy resources from photovoltaic sources 206 to be stored in low-voltage energy storage system 210 to compensate for the predicted future decrease in sunlight. Conversely, if the sunlight schedule predicts direct sun or an increase in the future amount of available sunlight, power control module 212 may reserve relatively less or a minimum amount of solar energy resources for engine system 204 and may distribute the remaining available energy from photovoltaic sources 206 to be used for other functionality.
In some embodiments, power control module 212 may use vehicle driving modes or status (e.g., park mode, drive mode, idle mode, start/stop mode, accelerating, decelerating, etc., which for example may be provided by vehicle telemetrics source 244) to determine an amount of energy to allocate to pre-heat engine system 204 or its components. The driving modes may be measured by, for example, sensing the engine 204 operation or monitoring the gears of the vehicle. The driving modes may be predicted (e.g., a driving mode to be expected in the future may be a predicted driving mode) using real time traffic information, for example, provided by vehicle telemetrics source 244 and/or a mobile device 248.
In one embodiment, when engine system 204 is in a driving or start/stop mode, the coolant system or another target component may reach an optimal temperature. The optimal temperature may be, for example, 45-50° C. or 90° C. (other temperature ranges or thresholds may be used). When engine system 204 has reached an optimal temperature, power control module 212 may allocate less energy to heater 224 to heat engine system 204 or a target component. Power control module 212 may change the amount of energy from photovoltaic sources 206 reserved for engine system 204 and alternatively allocate energy from photovoltaic sources 206 to other systems including, for example, an after-treatment system or any other vehicle systems. In some embodiments, power control module 212 may be in ongoing communication with one or more temperature sensor(s) 252 to receive temperature measurements over time. One or more temperature sensor(s) 252 may be, for example, located in engine system 204 and may measure the temperature of engine coolant system 226, engine block 228, engine cylinders 230, or any system or component. Power control module 212 may modulate energy or power allocations to pre-heat engine system 204 according to temperature measurements from temperature sensor(s) 252.
In some embodiments, power control module 212 may use a combination of factors, e.g., driving schedule, weather information (e.g., temperature and/or sunlight schedules), and driving modes, to determine a time schedule (e.g., pre-heating start times) and/or an energy schedule (e.g., variable amounts of energy allocated over time) to pre-heat engine system 204 to maintain optimal temperatures. Each set of vehicle telematics or factors used to control pre-heating may provide an extra degree of freedom to control engine system 204.
Other numbers, types and configurations of combustion chambers, exhaust valves, air-fuel ratios, engines, fuels, and engine systems may be used.
FIG. 4 is a graph of cumulative fuel consumption of an engine system with respect to time, and shows that faster coolant heating may result in less fuel consumption. Graph 400 may represent the cumulative fuel consumption of a vehicle and engine system during multiple identical New European Driving Cycles (NEDC) with different coolant system heating rates. Graph segment 402 may represent the vehicle speed over an NEDC drive cycle. Graph segment 404 may represent the fuel consumption of a vehicle, in which the engine coolant heats slowly over the NEDC drive cycle. The engine coolant system in the vehicle represented by graph segment 404 was not heated by any heater, heat exchanger or other device. In the example shown, the coolant system in the vehicle represented by graph segment 404 heated to 90° C. in 814 seconds. Graph segment 406 may represent the fuel consumption of a vehicle in which the coolant is heated with a heater (e.g., a heat exchanger, heating coil, heater or other heating device) during the NEDC drive cycle. The coolant system in the vehicle represented by graph segment 406 heated to 90° C. in 325 seconds. As shown in graph 400, a vehicle in which the coolant is heated with a heater or other device may consume less fuel. Of course, other vehicles, and other embodiments, may correspond to graphs with different data.
FIG. 5 is a graph of coolant temperature of an engine system with respect to time according to an embodiment of the present invention. Graph 500 may represent a coolant temperature, and its decline, from 0 to 8 hours after a vehicle with heated coolant is turned off. Coolant temperature 508 may be the temperature of the heated coolant as it declines after the engine is turned off, if no action is taken to heat the coolant. Coolant temperature 502 may be the minimum coolant temperature necessary to transfer from a typical combustion mode to an advanced combustion mode (e.g., HCCI combustion, lean SIDI combustion, etc.) or minimum coolant temperature necessary to transfer to warm engine calibration. Coolant temperature 502 may be, for example, 45-50° C. (other temperature values may be used in other embodiments). Coolant temperature 506 represents, in one example, the coolant system temperature when engine is first turned off, after the coolant has been heated. Heating energy 504 may be the energy required to maintain the vehicle coolant system temperature at or above coolant temperature 502 while the vehicle (or the engine) is not operating. Heating energy 504 may be, for example, 6 megajoules (MJ) over 8 hours to maintain the coolant system temperature at or above 45-50° C. Other heating energy values and temperature thresholds may be used in other embodiments. Photovoltaic source 106 may, for example, provide 5.76 MJ of energy over 8 hours or other amounts of energy. Heat received by photovoltaic source 106 may therefore maintain coolant system 226 temperature near 45-50° C. during direct sunlight weather conditions. Photovoltaic source 106 may provide more or less energy depending on the type of photovoltaic source, the size of the photovoltaic source and other factors.
FIG. 6 is a flowchart of a method according to an embodiment of the present invention.
In operation 600, energy may be received from a solar energy source (e.g., photovoltaic sources 106 of FIG. 1) electrically connected to a vehicle propulsion system (e.g., engine system 108 of FIG. 1). The solar energy source may be electrically connected to the vehicle propulsion system directly or via intermediate components such as a controller, batteries, etc. Electricity may be produced from the photovoltaic source.
In operation 610, a component of the vehicle propulsion system (e.g., coolant system 226 of FIG. 2) may be heated using at least some of the energy from the solar energy source. For example, coolant system may be heated using electricity from photovoltaic sources.
In operation 620, a control module (e.g., power control module 212 of FIG. 2) may provide an alert, indication or signal when the component of the vehicle propulsion system (e.g., coolant system 226) is heated within a predetermined temperature range associated with optimal efficiency. The alert may be issued to a driver, for example, or to a system controlling the engine, e.g., to change the mode or calibration of the engine. The alert may indicate that the vehicle propulsion system is started with optimal efficiency and may indicate when the vehicle propulsion system transfers to an advanced combustion mode (e.g., HCCI, PCCI, lean SIDI, etc.) or transfers to a different engine calibration (e.g., warm engine calibration). In some embodiments operations 600-620 may occur before the engine of the vehicle is turned on.
Other operations or series of operations may be used.
Embodiments of the present invention may include apparatuses for performing the operations described herein. Such apparatuses may be specially constructed for the desired purposes, or may comprise computers or processors selectively activated or reconfigured by a computer program stored in the computers. Such computer programs may be stored in a computer-readable or processor-readable storage medium, any type of disk including floppy disks, optical disks, CD-ROMs, magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs) electrically programmable read-only memories (EPROMs), electrically erasable and programmable read only memories (EEPROMs), magnetic or optical cards, or any other type of media suitable for storing electronic instructions. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein. Embodiments of the invention may include an article such as a non-transitory computer or processor readable storage medium, such as for example a memory, a disk drive, or a USB flash memory encoding, including or storing instructions, e.g., computer-executable instructions, which when executed by a processor or controller, cause the processor or controller to carry out methods disclosed herein. The instructions may cause the processor or controller to execute processes that carry out methods disclosed herein.
Features of various embodiments discussed herein may be used with other embodiments discussed herein. The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

Claims

1. A method comprising:

receiving energy from a solar energy source electrically connected to a vehicle propulsion system; and

heating, using at least some of the energy from the solar energy source, a component of the vehicle propulsion system.

2. The method of claim 1, wherein the energy to heat the component of the vehicle propulsion system is stored in an energy storage system separately from, and distributed by a control module independently of, energy provided to start the vehicle propulsion system.

3. The method of claim 1, wherein the energy from the solar energy source is used to heat the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.

4. The method of claim 3, comprising initiating heating the vehicle propulsion system prior to starting the vehicle propulsion system.

5. The method of claim 1, wherein the component of the vehicle propulsion system is engine coolant.

6. The method of claim 1, comprising receiving an indication of an anticipated start time for starting the vehicle propulsion system and initiating heating the component of the vehicle propulsion system a predetermined amount of time prior to the anticipated start time for starting the vehicle propulsion system.

7. The method of claim 1, comprising receiving information from a device external to the vehicle and changing the amount of energy from the solar energy source provided to the component of the vehicle propulsion system based on the received information.

8. A system comprising:

a solar energy source to collect solar power;

an energy storage system electrically connected to the solar energy source for storing energy generated thereby; and

a vehicle propulsion system, wherein the vehicle propulsion system is electrically connected to the energy storage system to receive energy from the solar energy source to heat a component of the vehicle propulsion system.

9. The system of claim 8, comprising a heater, wherein a controller allocates energy from the solar energy source to power the heater to heat the component of the component of the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.

10. The system of claim 9, comprising a temperature sensor to sense the temperature of the component of the vehicle propulsion system and wherein the control module is to change the amount of energy from the solar energy source allocated to the heater to compensate for the sensed temperature to heat the component to temperatures within the predetermined temperature range.

11. The system of claim 8, wherein the energy generated by the solar energy source is provided to heat the component of the vehicle propulsion system to temperatures within a predetermined temperature range associated with optimal efficiency for the vehicle propulsion system.

12. The system of claim 8, comprising a controller to initiate heating the component of the vehicle propulsion system prior to starting the vehicle propulsion system.

13. The system of claim 8, wherein the component of the vehicle propulsion system is engine coolant.

14. The system of claim 8, comprising a control module and an external device, wherein the control module receives information from the external device and changes the amount of energy from the solar energy source allocated to the vehicle propulsion system based on the received information.

15. The system of claim 8, wherein the system is a vehicle.

16. A method comprising:

generating electricity using a solar energy source attached to a vehicle; and

heating an engine coolant system of the vehicle using the electricity.

17. The method of claim 16, wherein the electricity used to heat the engine coolant system is stored in an energy storage system separately from, and distributed by a control module independently of, energy provided to start the engine.

18. The method of claim 17, comprising initiating heating the engine coolant system prior to starting the engine.

19. The method of claim 16, wherein the energy from the solar energy source is provided to heat the engine coolant system to temperatures within a predetermined temperature range associated with optimal efficiency for the engine.

20. The method of claim 16, comprising receiving information from a device external to the vehicle and changing the amount of electricity used to heat the engine coolant system based on the received information.