AU2016213721A1 - Thermal management system, vehicle, and associated method - Google Patents

Abstract

A method, comprising: switching a cooling system of a vehicle from a first mode of operation to a second, overcooling mode of operation; in the first mode of operation, maintaining a cooling element at a designated maximum threshold temperature during operation of an engine of the vehicle, wherein the cooling elemernt is associated with the engine; and in the overcooling mode of operation, powering the cooling system to cool the cooling element from past below the designated maximum threshold temperate to a lower, second threshold temperature,

Description

THERMAL MANAGEMENT SYSTEM, VEHICLE,

AND ASSOCIATED METHOD

[0001] The present application is a divisional application from Australian Patent Application No. 2014250734 (which is a divisional application of Australian Patent Application No. 2010276548) the entire disclosure of which is incorporated herein by reference.

BACKGROUND

Technical Field [0002] The invention includes embodiments that relate to a thermal management system for use in vehicle, the vehicle having the system, and an associated method.

Discussion of Art [0003] The engine coolant temperature of a haul truck or dumper has traditionally been controlled by a radiator fan that is mechanically linked to an output shaft of the engine. In particular, the radiator fan can be linked to the engine via a belt and clutch mechanism. The clutch is able to spin the fan at a desired fraction of engine speed, as dictated by a controller. At full engine power, the radiator fan can run at its full speed to provide cooling to the engine.

[0004] Running the cooling system comes at a fuel cost and power cost. Accordingly, cooling systems today minimize fuel consumption by picking an operating temperature that is as high as possible, and then maintaining that high temperature using the minimum cooling necessary.

[0005] Therefore, it may be desirable to have a vehicle and/or system with properties and characteristics that differ from those properties of currently available vehicles and systems. It may be desirable to have a method that differs from those methods currently available.

[0006] A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

BRIEF DESCRIPTION

[0006a] According to an aspect of the present invention, there is provided a method, comprising: switching a cooling system of a vehicle from a first mode of operation to a second, overcooling mode of operation; in the first mode of operation, maintaining a cooling element at a first threshold temperature during operation of an engine of the vehicle by actively cooling the cooling element when a temperature of the cooling element exceeds the first threshold temperature and not actively cooling the cooling element when the temperature of the cooling element reaches an intermediate threshold temperature lower than the first threshold temperature, wherein the cooling element is associated with the engine; in the overcooling mode of operation, powering the cooling system to cool the cooling element from below the first threshold temperature to a lower, second threshold temperature lower than the intermediate threshold temperature; and disabling the overcooling mode of operation in response to reaching a predetermined minimum threshold temperature and in response to an engine fuel usage amount.

[0007] According to another aspect of the present invention, there is provided a vehicle, comprising: an engine; a cooling system for cooling the engine, the cooling system having an electric device that is controllable independent of engine operating speed; a first energy source configured to supply electrical power to the electric device; and a controller configured to: responsive to a first condition, direct the electrical power from the first energy source to the electric device for operation of the cooling system in an overcooling mode, wherein in the overcooling mode the electric device is powered to continue to cool a cooling element from below a designated maximum threshold temperature to a lower, second threshold temperature, wherein the cooling element is associated with the engine; determine a heat rejection rate between the cooling system and an external environment based on one or more characteristics of the cooling system and one or more conditions of the external environment; and responsive to a second condition, disable the overcooling mode, the second condition including a cooling cost of cooling the engine above a designated cooling cost threshold, the cooling cost determined based at least in part on the heat rejection rate.

DESCRIPTION OF FIGURES 10008} The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, where like element, numbers refer to like elements, and wherein below: 10009} FIG. I is a schematic diagram of a thermal management system, according to an embodiment of the invention. )0010} FIG. 2 is a. schematic diagram of a thermal management system, according to another embodiment of tire invention, illustrating an overeooimg mode of operation.

[0011} FIG. 4 is a graph illustrating an overcooling mode of operation, in another embodiment.

[0012} FIG. 4 is a schematic diagram erf a thermal management system, according to another embodiment of the invention, illustrating a preceding mode of operation.

[0013} FIG. 5 is a schematic diagram of a· thermal management system, according to another embodiment of the invention, illustrating controlling a cooling system based on a determined heat rejection rate. }0014} FIG. 6 is a schematic diagram of a vehicle, according to an embodiment. 10015} FIG. 7 is a graph showing a comparison of duty cycles.

DETAILED DESCRIPTION (0016} The invention include® embodiments that relate to a thermal management svstem for use m vehicle, the vehicle having the system, and one or more associated methods.

[0017} in one embodiment, the system impieniemation includes a vehicle (e..g ·. a haul truck or dumper) in which one or more auxiliary systems of the vehicle, such as at engine cooling system, cm be controlled independently of engine speed. As noted above, this means that an auxiliary system is not mechanically driven, by the eng me and that the speed or oilier controllable aspect of the auxiliary system is not tied to the speed of die engine. The auxiliary systems can be -powered from different erseigy sources. Suitable energy sources can include m engine (e.g.„ electrical power provided by an engine-driven alternator and subsequent power converters suon as a rectifier, inverter, and the like); a regenerative braking system or ether dynamic 'braking system; and/or an energy storage system. Suitable energy storage systems may include one or more energy storage devices, such as batteries and other electrochemical devices, flywheels, capacitors, hydraulic accumulators, etc. As used herein, dynamic braking refers to slowing a vehicle by converting vehicle meehamcal energy to electrical energy (e,g., through traction motors of the vehicle), and «generative braking to a type of dynamic braking where braking-generated electricity is selectively stored in an energy storage system <as opposed to dissipating the electricity or immediately using the electricity). Ϊ0Θ1 SI In an embodiment, with reference to PI.C3. .1, a thermal management system i00 (e,g„ for a vehicle) includes a cooling system 102 for cooling an engine 104, a plurality of energy sources 106 (e,g., a first energy source 106a, a second energy source 106b,. a third energy source 106c, and so on), and a control!® 108. Ihe cooling system 102 has a first electric device 110 that is controllable independent of engine operating speed. (Meaning that the first electric device is not mechanically driven by trie engine and that the speed or other controllable aspect of the first electric device is not tied to the speed of the engine.) Each, of the plurality of energy sources 106 is controllable to supply electrical power 112 to the cooling system 102, 'Fhe controller 108 is operable to select a first energy source 106a from among the plurality of energy sources 106 and to direct: the electrical power from the first energy source 106a to the cooling system 102 for operation of the first electric device HO. 'flic .first energy source .106¾ is selected based on. at least one of (i) an availability of the first energy source and/or in) m energy cost factor 11.4 associated wife fee first energy source supplying the electrical power 112.

[0019| Regarding availability, in an embodiment, an energy source is available if. it can currently supply electrical power. Thus, an energy source is not selected if H cannot currently supply electrical power. In this embodiment, if an energy source can currently supply electrical power but not enough power to meet, a· designated mode, the energy source is still deemed available but augmented with other electrical power. in another embodiment, an energy source is available only if n can currently supply sufficient electrical power to meet a designated load Thus, in tins embodiment, an energy source is not selected if it cannot currently supply sufficient electrical power to meet the designated load. Regarding an energy cost lector 114, the controller 108 contains data/information correlating each energy source to a respective energy cost .factor. The energy cost factor is art estimation of what electrical energy from the particular source costs (results in or requires) in terms of one or mors system resources or operational parameters. For example, die energy cost, factor of each energy source may indicate how much fuel (or fuel equivalent factor) would in effect he consumed for a designated amount of electrical power to be supplied by the energy source. If the energy source is an engine alternator system, then the energy cost factor may be relatively high. On the other hand, if the energy source is a dynamic braking system, then fee energy cost factor may he relatively low. If the energy source is an energy storage device, then the energy cost factor may be relatively moderate (between relatively high and low vetoes). Other energy cost factors .may relate to vehicle emissions and vehicle performance (e.g.. available speed and power). Energy cost factor data/infonnation may be historical (generated by measuringsystem/vehicle •performance over many operational cycles, of the same vehicle and/or other vehicles in the same class) and/or derived concurrently by measuring current- system/vehicle performance. Alternatively or in addition, energy cost factors may be arranged or weighted hierarchically based on anecdotal evidence or estimations of vehicle system performance generally. For example, in the case of fuel (or fuel equivalent factor) consumed per 'unit electrical energy, electrical energy from a dynamic braking system may be considered lower in cost than electrical energy from an energy storage system which is lower in cost than electrical energy from an alternator system, based on general knowledge of vehide/system operation. The controller may include information on plural energy cost factors for each energy source, in which case an energy source may be selected based on assessing the plural energy cost factors of the various energy sources. {0020J Thus, to an embodiment, the controller 108 determines which energy source (out of a plurality qf energy sources 106) is most appropriate to supply electrical power for powering the cooling system 102 (e.g., the electrical power runs the electric device I i 0) to cool the engine, for reducing the average fuel bum and increasing vehicle productivity. For example, if first and second energy sources are available, an<1 the first energy source has «... lower fuel burn-related energy cost factor than the second, then selecting the first energy source for powering the cooling system will .result in reduced fuel usage. Further fuel usage and vehicle productivity benefits may be achieved by additionally or alternatively controlling the cooling system in, an overcooling mode of operation, as explained elsewhere herein in more detail.

[0021,] An example of a cooling system electric device 110 is ft radiator fan 116 and radiator fan motor ϊ 18. The radiator fan 11:6 is operably coupled to the radiator fan motor TIB (e.g., the radiator fan is attached to an output shaft of the radiator fan motor), such that when the radiator fan motor is electrically powered, the radiator fan is rotated. Typically, the radiator fan would be associated with a radiator portion of the cooling system. The radiator fart is controllable independent of engine speed because die radiator fan is not mechanically driven by the engme* but is instead driven by the radiator fait motor. Other examples of cooling system electric devices include blowers, other types of fans, and pumps.

[0022} In an embodiment, the cooling system electric device 110 is powered (or the cooling system may be otherwise powered) to cool a cooling dement 120 associated with the engine 104. ‘'Cooling element" refers to a portion of the engine that is cooled, or an element that is cooled to in turn cool a portion of She engine. In. regards to the former, one example of a cooling element may be an engine .manifold (e.g\, exahaust or intake manifold), or an engine block or portion thereof. In regards to the latter, one example of a cooling element 120 is a cooling fluid (a coolant such as water mixed wish aritifree^e) in a·'fluid circuit 122 associated with the engine 104 and cooling system 102. Another example of a cooling element 12.0 Is cooled air that is blown onto or into the engine for cooling purposes, in the case of a cooling fluid in a fluid circuit '122, the fluid circuit may comprise a cooling fluid reservoir, cooling jackets around an engine block, a wafer pump, valving or other control elements, a radiator, and tubing/hoses for fluid interconnections. Thus, &amp; radiator fan motor 1 i 8 .may be electrically powered to drive a radiator fan 116 for blowing air across or through the radiator, for heal exchange from the cooling liquid ίο the sir, and thereby cooling "the cooling liquid. |0023| According to one aspect of the invention, the cooling system '102 may be operated in an overcooling mode of operation, In the overcooling mode of operation, instead of maintaining the temperature of a. cooling element (eg., cooling fluid, or engine or vehicle components} at a designated tmximum threshold temperature, the cooling element is cooled to a low temperature within an acceptable temperature range, using relatively "low cost” electrical power. The low cost electrical power may be provided from a first energy source 106a having a lowest energy cost factor II4 among available energy sources 106, In one example, such a first energy source 106a is a dynamic braking system. Overcooling a cooling element will delay the need for cooling when low cost electrical, power is no longer available, such as when motoring, effectively resulting in additional traction power available during that period and a lower overall load factor. |00241 la an embodiment, therefore, with, reference to FIG. 2, m a thermal management sysiem 200, a controller 108 is operable to direct decirical power 112 from a first energy source 106a to a cooling system 102 for operation of the cooling system 102 in an overcooling mode 124. (Although plural energy sources are shown, it may be-the case that the system only has one energy source) In the overcooling mode 124,. a,first electric device 110 of the cooling system 102 is powered to continue to cool a cooling element 120 .from below past a designated maximum threshold temperature 13 (see point or region 126) to a lower, second threshold temperature i5. (As explained above, the cooling eieraenPi20 is associated with the engine 104.) |Q02S] To explain further, PIG. 2 shows a hypothetical graph illustrating an example plot of temperature T (y-axis) versos time t (rwaxis) for a cooling element 120. Thai is, the graph shows how the temperature T of the cooling element 120 varies over time t, in several possible operating modes of the cooling system m die thermal management system. In the graph, T1 represents a. minimum allowed temperature ot the cooling element and T4 a maximum allowed temperature of the cooling element, m between which is an allowed temperature range of the cooling element. 11 and s 4 may be designated levels, and/or they may represent physical limits of the cooling element (such as a freezing point and point where damage may occur, respectively), in a time period prior to t'L the temperature of the cooling element is rising, for example, due to engine operation. Temperature T3 represents a designated maximum threshold temperature. The designated maximum threshold temperature T3 is the designated temperature at which operation of the cooling system is initiated in order to prevent the cooling element from overheating (e.g., reaching or approaching dose so the maximum allowed temperature T4. Thus, before timetl, the cooling system.is deactivated (or at least not powered sufficient to prevent the temperature from increasing), and at time tl, corresponding to temperature T3, the cooling system is activated for cooling the cooling dement 120.

[00261 Between time tl and time 12, the temperature of the cooling element may continue to rise due to lag time from when the cooling system is activated to when, the temperature of the cooling element drops. However, the temperature of the cooling element eventually falls, reflecting that the cooling system is acting to cool the cooling element (e.g., even though the cooling element may continue to receive heal energy from the engine or otherwise, tbs cooling system acts to lower the net-energy level of the cooling element). At time 12, the temperature falls to the designated maximum threshold temperature Ό. In a first, ‘"regular" mode of operation 128, subsequent to time £2, the cooling element 120 is maintained a! the designated maximum threshold temperature T3 during operation of an engine of the vehicle. “Maintained at” includes keeping the cooling element temperature at the designated maximum threshold temperature T3 and/or cycling the cooling element temperature around the designated maximum threshold temperature T3, such that the designated .maximum threshold temperature T3 acts as a trigger for activating the cooling system and, in some embodiments, deactivating the cooling system. Specifically, when the cooling element temperature rises above Ό, the cooling system is activated (powered), and. in some embodiments, if the cooling element temperature Ms below T3, the cooling system is deactivated (not powered). {0027) In the overcooling mode of operation 124, at time t2, instead of deactivating the cooling system 102, the cooling system 102 is powered to continue to cool the cooling demerit 120 from below past the designated maximum threshold temperature T3 to the lower, second threshold temperature T5. (The point below past the designated maximum threshold temperature T3 is shown generally at 126.) T5 is shown in FIG, 2 as ..having a range between T3 and a temperature T2. Temperature T2 is a predetermined .minimum threshold temperature, meaning a designated lowest temperature limit below which die cooling system is never powered for further actively cooling the cooling element. In other words, the predetermined minimum threshold temperature T2 is a designated temperature point, at a temperature different from and below the designated maximum threshold temperature T3, to which the cooling element may-be cooled but not actively exceeded. Thus, die second threshold temperature T5 lies below the designated maximum th.reshold temperature T3 and at or above the predetermined minimum threshold temperature T2. In an embodiment, in the overcooling mode of operation .124, the cooling system .102 is powered to continue to coot the cooling element 120 from below past die designated maximum threshold temperature T3 to the predetermined minimum threshold temperature T2. In an embodiment, the second threshold temperature T5 reflects the lowest temperature, at or above the predetermined minimum threshold temperature T2,"that the system is able to achieve during a given overcoohng operation based on energy source availability, energy cost factors, vehicle operating parameters, the time available for operating in the overcooling mode, etc. (00281 The predetermined minimum threshold temperature T2 may be coincident with the minimum allowed'temperature T1 of the cooling element "120. Alternatively, actively cooling the cooling element (powering the cooling system to cool the cooling element) to the minimum allowed temperature XI may cause the temperature of the cooling element to fall below the minimum, all owed temperature T1. Accordingly, the predetermined minimum threshold temperature T2 may be above the minimum allowed temperature ΊΊ, but within a certain range of the minimum allowed temperature Tl. For example, depending on cooling system characteristics, the predetermined mini mum-threshold tetnperatnre T2 may he at or within five· to twenty percent of the allowed temperature range of the minimum allowed temperature Tl. That is. if the allowed temperature range is denoted as R T4-T15 then ((Tl + 0.0SR) < T2 < (Tl f· 0.2RR). |.n other embodiments, again depending on cooling system characteristics, the predetermined minimum threshold temperature T2 is at or within five to too percent, or ten to fifteen percent, or fifteen to twenty percent, of the allowed temperature ..range of the minimum allowed temperature Ti. 1,00291 in FIG; 2, the second threshold temperature T5 is illustrated as coincident with the predetermined minimum threshold temperature Ϊ2, which is above the minimum allowed temperature I t Titus, in die overcooiing mode 124, subsequent to time t2f the cooling system '102 is powered to continue to cool the cooling element 120 from below past the designated maximum threshold temperature T3 to the lower, second threshold temperature T5, which in this example is the predetermined minimum threshold temperature T2. Once the temperature of the cooling element reaches the second-lhres.ho.id temperature T5 (the predetermined minimum threshold temperature T2) at time 13, the cooling system is deadivated/dwpowersd, allowing the cooling element temperature to rise (possibly after a lag) due to continued operation of the engine. (0030J In another embodiment, with reference to i'lG, 3, in the overcoming mode 1,24, a first electric device 1.10 of the cooling system 1.02 is powered to continue to cool a coding element 120 from, below past a designated intermediate cycle threshold temperature T6 (see ..point or region 126) to a lower, second threshold temperature T3. {The designated intermediate cycle threshold temperature T6 is above the second threshold temperature T5 and below she designated maximum threshold temperature T3; thus, continuing to cool a cooling element 120 from 'below past a designated intermediate cycle- threshold temperature "Γ6 is a species/variant of continuing to cool the cooling element from below past a designated maximum threshold temperature T3.) To explain .further, in this embodiment, in a first mode of operation 128, the cooling element 120 ss maintained at the designated maximum threshold temperature T3 during operation of an engine of the vehicle. Bare, "maintained af" more specifically refers to cycling tlie cooling element temperature around the designated maximum threshold temperature T3 and around the designated intermediate cycle threshold temperature T6, Thus, the designated maximum threshold temperature T3 acts as a trigger for activating the cooling system, and the designated intermediate cycle threshold temperature T6 acts as a trigger for deactivating the cooling system.

Specifically, when the cooling element temperature tails below T6 (time t3)„ the cooling system is deactivated (not powered), and when the cooling element temperature rises above T3 (time tl), Ihe cooling system is activated (powered), .In the overcoofing mode of operation, instead of deactivating or de-powering the cooling system when ihe cooling element temperature falls below T6 (time t3), the -.first electric device 11,0 of the cooling system 102 .h powered to continue to cool the cooling dement 1.20 from below past T6 to a lower, second threshold temperature T5. (0031J The embodiment of FIG. 3 illustrates that a first ‘Tegular’ (or otherwise) mode of operation 128 may be more complex than simply cycling the cooling system 102 on and off around a single temperature point 13, liras’, regardless of how a cooling system is cycled in a first mode of operation, the overcooUng mode provides a mode of operation for continuing to actively cool a cooling dement (e.g., by electrically powering an electric device of the cooling system) below the lowest point of the first mode where active cooling is maintained. (00321 Further in regards to the embodiment of FIG·. 3, a. thermal management system .may comprise a cooling system for coding an engine, one or more energy sources each configured to supply electrical power to the cooling system, and a controller. The cooling system has an electric device that is controllable independent of engine operating speed. The controller is operable to direct the electrical power from at least one of the one or more energy sources to the cooling system for operation of the cooling system in a first mode of operation and in a second, overcoming mode of operation, hi the first mode of operation, the electric device· is not powered to cool a cooling element, (associated with the engine) any lower than a first threshold temperature. In the overcoming mode of operation, the electric device is powered to continue to cool the cooling element below the first threshold temperature to a lower, second threshold temperature. (00331 in a specific «sample of overcoming, a thermal management system includes a cooling system 102 for an engine .104, a dynamic braking system 106¾ and a controller 1.(¾¾. Tne cooling system 102 includes a radiator fan motor '116 and a radiator fan 118. The radiator fan. motor lif> is coupled to the radiator fan 118 for driving the radiator fan 118, 'When the radiator .fen is driven, it cools a cooling fluid 120 in a fluid circuit 122 associated with the engine 104 and coding system 102 (e.g., m conjunction with a radiator). The controller 108 monitors the dynamic braking system 106a, and when electrical power 112 is available from the dynamic hrakmg system 106a, the controller 108 directs the electrical power 112 from the dynamic braking system 106a. to the radiator fan motor ! 16, for overcooling the cooling fluid 120, That is, the radiator fan motor 116 is -powered to cool toe cooling fluid 120 from below past a designated maximum threshold temperature T3 (FIG. 2). or irons below past &amp; designated intermediate cycle threshold temperature T6 (FIG. 3)., or otherwise below past a lowest temperature at which active cooling of the cooling fluid is continued in one mode of operation 128, to a lower, second threshold temperature '1 ·-The second threshold temperature TS may be a predetermined minimum threshold temperature T2 of the cooling fluid. 10034] in an embodiment, one of toe energy sources 106 is an energy storage system having one or more energy storage devices. The energy storage device may he pre-charged (that is charged when the vehicle is parked and able to connect to a charging station), or it may be charged during operation of the vehicle, such as by receiving electrical power from an engine alternator system, or from an external source (e.g.. catenary line or ‘"third raiP-type device), or from a. dynamic braking system, or from other charging means (e g., scavenging elecricity from a turbocharger). If a vehicle Has a dynamic braking system, the energy storage device may be electrically coupled to the dynamic braking system, and the energy storage device may be operable to supply eiectrical power from the dynamic braking system to a cooling system electric device in response to a signal from a controller (regenerative braking). Thus, similar to as previously described above, when dynamic braking energy is available (from the energy storage device or directly), the system will cool a cooling element (e,g., cooling fluid, or engine part or other vehicle pan.) to a low temperature within an acceptable temperature range. This will delay the need lor cooling when dynamic braking energy is no longer available, such as when motoring, effectively resulting in additional traction power available during that period and a lower overall load factor. 1003:?! A suitable storage system can include a variety of energy storage devices,. A suitable energy storage device may include, for example, a sodium metal halide battery, sodium sulfur, lithium ion battery, nickel metal hydride, nickel cadmium, arid the like, as well as other energy storage mediums such as capacitors» fuel cells, fly wheel devices, and the like. While the energy storage devices listed here may not be entirety interchangeable in ail circumstances, they may he selected based on the end use requirements and constraints, {tM)36| In another embodiment, with reference to FIG. 4. m overcooiing mode of ooeration is initiated for precooltpg purposes. 11 ore, a thermal management system 300 indudes a,cooling system ‘02, an engine '104, one or more energy* sources .106. and a controller 108. Overall arrangement and operation is ami tar to what is described above in regards to one or more of FIGS. 1-3. However, the controller 108 is additionally or alternatively configured to identity a time period UO preceoing a Scad *ΜΓ of the engine or vehicle exceeding a designated load threshold ’‘MV' based on a learned duty cycle 132 of the engine. Further, an. overcoming mode of operation (such as described above).is initiated during the time period 130. |00371 To explain further, in the thermal management system 300» the system amlcspates periods thai precede heavy engine load portions of toe haul cycle, and precools the engine to delay the need for cooling during toe heavy engine load portions. For this purpose, the controller 108 has information about a learned duly cycle 132 of the engine. In a very simple example, a teamed duty cycle is simply a measure of engine/vehicie load as a, flmclion of lime during a cycle of operation, where the cycle is repeated and the measure of load is thereby applicable across multiple repeating cycles. {An example is a. haul truck wherein for each cycle of operation, the haul truck rum the same route and performs toe same tasks.) In more complex examples, toe learned, duty cycle incorporates additional factors besides load and time (all factors referred to as *1" in toe graphs of FIG. 4), such that load levels can be anticipated not only as a function of time, but also of current vehicle operating conditioux'parameters. Methods for generating learned duty cycles are known in the art. For example, see US. Pal. No 6601442 to Decker et al. ).0038} In the thermal management system 300, toe controller 108 is provided. With date/information of toe learned duty cycle 132. The data%formation may be loaded into toe controller 108 (e.g.·, into controUer-aecessihle memoiy) in advance of vehicle operation. Alternatively or additionally, the controller 108 may be configured to generate a learned dutv cycle 132 by monitoring or measuring vehicle operations and processing data, of the monitored or measured vehicle operations according to a designated method .for generating a learned doty cycle 132. in either case, during vehicle/engine operations, the controller 108 identifies a time period 130 preceding a load M of the engine or vehicle exceeding a designated load threshold Ml. The time period BO is identified based on <i> the learned duty cycle 132, and (ii) one or more monitored or measured operating parameters 134 of the vehicle/engine (e.g.. time ot operation, fuel usage, emissions output, vehicle speed, and the like). Again in a simple example, for a kradfome-based learned duty cycle 132, -the controller H?8 cross-'Tsfersnees the start time t6 of a new, current haul cycle with a start time index t7 of the learned doty ovcle 132. From the learned duty cycle, the controller 10S knows drat a time period 136 of the learned duty cycle 132 immediately precedes a time period 138 where the engine load M of the learned duty cycle 132 exceeds foe threshold ML The time period '136 is defined not only by time data, but also one or more load waveforms (e.g., 140) that precede the time period 136. For identifying the time period !30, foe controller 108 tracks bath the current time and the current load, which are correlated to -the learned duly cycle 132. For example, in the graphs shown in FIG 4. a currently measured load waveform 142 corresponds to the .learned duty cycle waveform 140 (that precedes the time preceding the heavy- load period), Also, Hie currently measured load waveform 142 is relatively close in time to foe learned duty cvcle waveform 140. From this, the controller 108 extrapolates that the time period 130 subsequent to the currently measured load waveform 142 likely corresponds to the time period 136 of the learned duty cycle 132, which is expected to immediately precede a load exceeding the threshold ML For further context, as art example, load M0 may correspond to engine idle, load M2 to motoring along «.flat surfo.ee load M3 to a haul truck damp operation, and M4 to the vehicle traversing a steep incline. 10039] Once foe controller 108 identifies a lime period B0 preceding a load of the engine or vehicle exceeding a designated load threshold, an overcooling mode of operation (such as described above) is initiated during the time period 130, in advance of the anticipated heavy toad period. ("Heavy" defined m a load exceeding the designated load threshold.) Initiating an overcooling mode of operation results in a cooling element (e.g., engine component) being cooled ahead of the heavy load period. This delays the need for cooling during the heavy load period, which may result in lowered ..fuel usage and/or improved vehicle power. I0040J Another embodiment; utilizes duty cycle matched cooling. Here, during portions of a duty cycle where cost of cooling is high (e.g.. when a vehicle is motoring and under heavy load), the coding level is set to an estimated level required to minimally meet cooling requirements, such that component temperatures rise using all the thermal capacity of the system while staying within the maximum operating limits. The estimated level may be determined based on learned duty cycle, ambient conditions, etc. 100411 In another embodiment, cooling system operation is controlled based (at least in part) on a determined heat rejection rale. In particular, the controller IDS is configured to determine a heat rejection rate between the cooling system 102 and an external environment based on one or mors characteristics of the cooling system 102 and one or snore conditions of the external environment. The controller is also configured to control the cooling system'based, on the heat rejection rale. 10042-1 In determining the heat rejection rate, the characteristics of the cooling system 102 may include a type of the cooling fluid, a volume of the cooling fluid, a Sow rale of the cooling fluid, an age and/or history of the cooling fluid, and/or one or more characteristics of a radiator portion of the cooling system. The one or more conditions of the external environment may include a temperature of the external environment, barometric pressure, etc. (0043) FIG. 5 shows a more specific example of a thermal management system 400 where cooling system operation is controlled based (at least in part) on a determined heat rejection rate HiRR'f in partciular, the controller 108 is configured to determine a heat rejection rate HER between the cooling system 102 and an external environment based on one or more characteristics of the cooling system 102 and one or more conditions of the external environment. (In one example, HER is determined based on a temperature difference between a temoerature of the cooling system {cooling element) and a temperature of the external environment,) The controller 108 is additionally configured to disable the overeooling mode of operation when a cooling cost "Cif" of coaling the engine 104 (using electrical power from a particular energy source or otherwise) is above «..designated cooling cost threshold "'Cu " (The graph is FIG. 5 is an example illustration of a cooling cost C versus time t curve.) The cooling cost C is determined based at least in pari on the heal rejection rate, that is. the cooling cost is a function of the heat rejection rate HRR, C f (HRR). {0044J in an embodiment, the cooling system 102 is otherwise controlled based on a determined 'heat rejection rate between the cooling system and the external environment. For example, a cooling level provided by the cooling system (e.g;, at airflow provided by electrically 'powering a radiator fan motor) may be adjusted based on a determined heat rejection rate, so as not to provide more cooling ihan required. For example, it a determined heat rejection rate is indicative of favorable conditions for heat transfer to the external environment (such as the external temperature being significantly lower than the temperature of the cooling element or system), then the cooling system may he turned off (de-powered), or powered to less of an extent (in terms of power level and/or active/‘kon',time) titan it.would be if conditions were less favorable for heat transfer to ambient (external environment), (0045} Other embodiments relate to methods for thermal management (e.g., in a vehicle). 1« one aspect, a method includes switching a cooling system 102 of a. vehicle.-from a first mode of operation 128 to a second, overcoming mode of operation 124. In the first mode of operation 128, a cooling element 120 (associated with an engine 104 of the vehicle) is maintained at a designated maximum threshold temperature T3 during operation of the engine, hi the overcooling mods of operation 124, the cooling system 102 is powered to cool die cooling element 120 from past below the designated maximum threshold temperature T3 to a lower, second threshold temperature T5.

[O04&amp;I In another embodiment of a method, the cooling element is a cooling fluid in a Quid circuit 122 associated with tire engine 104 and cooling system "102. 'lire second threshold temperature is a predetermined minimum threshold temperature T2 of the cooling fluid.

[00471 j.o another embodiment of a method, the step of powering the cooling system 102 in the overcooling mode 124 includes directing electrical power 112 from a dynamic braking system ,106a of the vehicle to the cooling system 102.

[0048} In another embodiment of a method, the method further includes the steps of determining when the electrical power from the dynamic braking system is available, and initiating the overcooling mode when the electrical power from the dynamic braking system is available.

[0049] In another embodiment of a method, the method further includes 'the step of selecting a first energy source of the vehicle for powering die cooling system in the overcooling mode. The first energy source is selected from among a plurality of energy sources m the vehicle The first energy source is selected based on at least one of an availability of the first energy source and/or an energy cost factor associated with the first energy source powering the cooling system. 10050} In another embodiment of a method, the method further includes the step of identifying a time period 130 preceding a load M of the engine 104 exceeding a designated load threshold Ml, based on a learned duly cycle of the engine. Additionally, the overcooling mode of operation is initiated during the time period, for preceding in advance of a· heavy load period.

[0051] in another embodiment of a method, the method further includes, for one or more energy sources 106a»JQ6c of die vehicle available tor powering die cooling system. .102, the step of assessing one or more energy cost factors (114,. C) respectively associated with the one or more energy sources. Further, switching to the overcooling mode of operation is precluded if none of the one or more assessed energy cost factors is below a designated cost threshold. That is, in an embodiment, .in order to initiate the overcooking mode of operation, die cost factor of at least one available energy source is below a designated threshold (indicative that the available energy is low cost enough to warrant operation in the overcoohng mode), [0052} In another embodiment of a method, the method further includes die step of identiiying a first assessed energy cost factor of the one or more energy cost factors that is lowest: below the designated cost threshold. The cooling system is powered in the overcooling mode of operation «sing a first one of the one or more energy sources •that is associated wife the fmi assesses! energy cost factor, .for example, with reference to FIG. L if ail the cost factor's 114 of the energy sources 106a, SOob. 106c are below a designated cost threshold, then the identified first assessed energy cost factor would be the one associated with energy source 106b. and the coolmg system would be powered in the overcooling mode of operation using dec-meat power provided by the energy source 106b. (00531 With reference to FIG. 6. another embodiment relates Ίο a vehicle 500. The vehicle 500 includes an engine 104, a cooling system 102 for cooling the engine, a first energy source 106a configured to supply electrical power H2 to the cooling system* arsd a controller .10¾. (Plural energy sources are shown in FIG. 6« but it. may be the case that the vehicle has only one energy source.) The cooling system 102 has an electric device 110 that is controllable independent of engine operating speed, The controller 108 is operable to direct the electrical power 112 from the first energy source 106a to the cooling system .102 for operation of the coding system in on overcooling mode of operation 1.24. In the overcooling mode, the electric device 110 is powered to continue to coo! a cooling element 120 (associated with the engine) iront below past a designated maximum threshold temperature 13 to a lower, second threshold temperature T5 (see FIGS. '1 and 3).

[00S4] In another embodiment of a vehicle, the vehicle has a plurality of energy sources 106, each controllable to supply electrical power to the cooling system. Additionally or alternatively to having functionality for eiTectuatiftg an overcooiing .mode of operation, the controller is operable to select a first energy source .from among the plurality of energy sources and to direct the electrical power from the first energy source to the cooling system for operation of the electric device. The first energy source is selected based on at least one of an avail ability of the first energy source and/or an energy cost factor associated with the first energy source supplying the electrical power. 100351 In another embodiment of a vehicle, the electric device of the cooling system comprises a radiator fan and a radiator fitn, motor coupled to the radiator fan for driving the radiator fan. The cooling element is a coolina fluid in a fluid circuit associated with the engine and cooling system, The first energy source is a dynamic braking system ««.figured to supply the electrical power to the radiator Ian motor during a braking event. The coniroiler is operable to direct the electrical power from the dynamic braking system lo the radiator fan motor to cool the cooling fluid to the second threshold temperature. The second threshold temperature may be a predetermined minimum threshold temperature of the cooling fluid {00561 Embodiments of a system, method, or vehicle herein may include a controller to determine which of a plurality of energy sources is the moss; appropriate :to use to provide cooling to the engine and the amount of cooling needed, based on a plurality of external parameters and internal logic. For example, a suitable controller can manage the energy usage to minimi*» the average fuel bum and umimixe the productivity of the truck. '.The factors and logic may be based, at least in part, on a learned engine duty cycle over the haul profile, engine cooling requirements, availability of energy sources such as state of charge or stale of health, impact of energy source on fuel consumption, with the engine itself having the most negative impact and dynamic braking energy having the lowest impact, and the benefit of precooling' or other ovencooling on productivity and speed on. grade. 10057) 'With regard to overcooling using energy derived from dynamic braking, there are several operational modes .from which a controller may select, in one operational mode, when dynamic braking energy is available, the system controller will attempt to cool the engine end vehicle components to a lowest temperature available within the acceptable temperature range This will delay the need for cooling until later m the job when dynamic braking energy may' no longer be available, such as when .motoring. This overeooling may effectively result in additional traction power available during that period and a lower overall load factor.

[00581 Another mode of operation may include ambiemmiatched cooling. The system controlier will estimate the heat rejection rate between the cooling system and the environment based on several factors. The factors can include one or mure of following: characteristics of the cooling system, heat rejection rate, ambient conditions, and other factors.

[0659} Suitable characteristics of the cooling system can include the type of coolant, foe volume of coolant, the coolant flow ratty age or history of the coolant (e.g., when the coolant was added/replaced), and specifics related to the radiator design, such as the number of turns, the cleanliness of the radiatorfim, age of the pump, and the like. With regard to the heat rejection rate of the engine to the cooling system, tire system can. calculate the rate, measure the rate, or case the value on predetermined data. For the ambient conditions, suitable conditions can include the time of day, humidity, temperature, 'barometric pressure, weather type, and dust/dirt levels of operation. Other factors cart include historical data calculations for the vehicle in question, or for another vehicle in a fleet of vehicles, or an average of all or a. subset of vehicles in the •fleet.

[0060j During use, the controller can adjust the airflow provided by the cooling system so as to avoid providing more cooling than required and to avoid overcooling foe components when the cooling cost function is at or approaching a peak cost. A peak cost may occur, for example, when motoring power is being drawn from foe engine as opposed to being drawn from an energy storage system. The system controller may limit foe impact of cooling on fuel consumption.

[00SJ} In one embodiment, the confooiler may institute a . precooling or duty-cycle matched coohng mode of operation. In response to foe vehicle duty cycle, (he-system controller anticipates periods proceeding heavy engine load portions of the hard cycle. "In. response to such periods, foe controller precools the engine to delay the need for cooling during foe heavy engine load portions. Also, during portions of the cycle where cost of cooling is high, cooling level may be set to an estimated level required based on the above-disclosed factots such that component temperatures rise using all the thermal capacity of the system while staying within foe maxi «nun operating limits. 10062} In one embodiment, an engine-speed independent fart driver topology and a dynamic braking energy may be utilized by a controller that anticipates the cooling needs of foe engine and its duty cycle to provide cooling in a way that mimmixes the impact of cooling on fuel consumption, engine emissions, vehicle power, and/or productivity.

[0063| With reference to FIG. 7< two duty cycles are compared and shown by the •indicated graab, which illustrates the efiects oi over cooling, tor example, over the course of driving a full haul track load oi ore up an incline, dumping the load., and returning to the shove! site to collect another ore load, the engine needs to output power to meet the demands of the job. Ihe two hoes 144, 146 indicate power usage over elevation with and without overcool lag oi Use coolant in the nuha&amp;or system The x~ms is time, and the y-axis is energy expended (in. horsepower) to run the radiator fan (which also corresponds, in etfeci, to iuel consumption). The line 144 shows engagement of foe engine at about loO seconds (in ine case oi no overcooling), and at about! 80 seconds, for line 146, with overcooling. That is, the coolant having a lower temperature takes longer to reach a ihresnoid lemperatuie In at w.ol activate the cooling fan motor, Thus, approximately 90 hp which would, otnerwute be consented isy the fen motor would be available for use in propelling the vehicle for (hose twenty seconds. All other variables being equal the vehicle would arrive at the top of the elevation having less thermal load, and would scan the non-climb portion of the duly cvcie with a cooler temperature than it would otherwise have. On the descent, the controller may divert at least some of the electrical energy flowing from foe traction motors Into the resistor grid to the radiator fan motors). Rather than burning fuel in the engine to cool the system on the descent, the dynamic braking system provides power to cool the coolant to the minimum threshold temperature 12 (or another reduced teropeature 13). Thus, less fuel may be consumed during the vehicle descent trip as well j00d4[ In an alternative embodiment, as opposed to or in addition to cooling- foe cooling -fluid, the controller can also activate one or more cooling blowers to provide coolinu air to one or mom of a set of electronic devices, mechanical/structural devices, etc. Suitable electronic devices may include one or more of the control electronics group, power eleelramcs, traction motors, and foe like. Suitable mechanical/structuraJ devices may include one or .more of foe cab environment., lubrication fluid, a thermal beat sink, and/or gearing. Cooling, and particularly overcooling to a minimum threshold temperature, may allow tor longer operating periods at sub-maxi mum operating temperatures due to (he lower initial temperature starting point.

[0065) In another embodiment, materials are selected for use in the system that have relatively better thermal cycling characteristics to better handle fee larger temperature swings of fee system components being cooled. |t)0661 As noted, a thermal management system (or associated method) may be .implemented in or as a vehicle. Example vehicles include haul trucks or dumpers, and especially high capacity haul trucks as used in mining operations, e.g., having a capacity of 100-400 tons.

[0067) The controller 108 may be a computer, microcontroller, or other electronics device configured for carrying out control functions as described herein, based on stored program instructions., a configuration, of fee electronics (hardwired control), or the like. )0668] lit an embodiment, a thermal management system includes a plurality of “first” operational modes, and in addition to the plurality of first operational modes, an overcooling mode of operation. The -plurality o.f first operational modes comprises all the modes of operation of the thermal management system except for the overcoo.ii.og mode, feat is, there are no other modes of operation other than the first operational modes and the overcooling mode. In all fee first operational modes wheu viewed together, a cooling element is cooled to no lower than a first temperature. In fee overcooling mode of operation, the cooling dement is cooled to a second temperature that is lower than the first, temperature. Thus, out of all the modes of operation of the thermal management system (including the first modes and the overcoolign mode), fee overcooling mode cools the cooling element to the very lowest temperature out of any and all of the modes. In an embodiment, the cooling element is a cooling fifed, and the thermal management system is in a vehicle, 't hus, out of all the modes of operation for cooling the cooling fluid in fee vehicle, the overcooling mode cools fee cooling fifed to the very lowest temperature out of any and all of fee modes.

[0069] It is ΐο be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosed subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the disclosed subject matter, they are by no means limiting and are exemplary embodiments. The scope of the described subject matter should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled, In the appended claims, the terms "including" and "in which" are used as the plain-language equivalents of the respective terms "comprising" and "wherein." Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects, [0070] This written description uses examples to disclose several embodiments of the described subject matter, including the best mode, and also to enable any person skilled in the art to practice the embodiments of subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims, [0071] Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereto.

Claims (12)

1. The claims defining the invention are as follows:

   1. A method, comprising: switching a cooling system of a vehicle from a first mode of operation to a second, overcooling mode of operation; in the first mode of operation, maintaining a cooling element at a first threshold temperature during operation of an engine of the vehicle by actively cooling the cooling element when a temperature of the cooling element exceeds the first threshold temperature and not actively cooling the cooling element when the temperature of the cooling element reaches an intermediate threshold temperature lower than the first threshold temperature, wherein the cooling element is associated with the engine; in the overcooling mode of operation, powering the cooling system to cool the cooling element from below the first threshold temperature to a lower, second threshold temperature lower than the intermediate threshold temperature; and disabling the overcooling mode of operation in response to reaching a predetermined minimum threshold temperature and in response to an engine fuel usage amount.
2. 2. The method of claim 1, wherein the cooling element is a cooling fluid in a fluid circuit associated with the engine and cooling system, and wherein the second threshold temperature is the predetermined minimum threshold temperature of the cooling fluid.
3. 3. The method of claim 1 or 2, wherein the step of powering the cooling system in the overcooling mode comprises directing electrical power from a dynamic braking system of the vehicle to the cooling system.
4. 4. The method of claim 3, further comprising: determining when the electrical power from the dynamic braking system is available; and initiating the overcooling mode when the electrical power from the dynamic braking system is available.
5. 5. The method of any one of the preceding claims, further comprising: selecting a first energy source of the vehicle for powering the cooling system in the overcooling mode, the first energy source being selected from among a plurality of energy sources in the vehicle, and the first energy source being selected based on at least one of an availability of the first energy source and an energy cost factor associated with the first energy source powering the cooling system.
6. 6. The method of any one of the preceding claims, further comprising: identifying a time period preceding a load of the engine exceeding a designated load threshold, based on a learned duty cycle of the engine; and initiating the overcooling mode of operation during the time period.
7. 7. The method of any one of the preceding claims, further comprising: for one or more energy sources of the vehicle available for powering the cooling system, assessing one or more energy cost factors respectively associated with the one or more energy sources; and precluding switching to the overcooling mode of operation if none of the one or more assessed energy cost factors is below a designated cost threshold.
8. 8. The method of claim 7, further comprising: identifying a first assessed energy cost factor of the one or more energy cost factors that is lowest below the designated cost threshold; and powering the cooling system in the overcooling mode of operation using a first one of the one or more energy sources that is associated with the first assessed energy cost factor.
9. 9. A vehicle, comprising: an engine; a cooling system for cooling the engine, the cooling system having an electric device that is controllable independent of engine operating speed; a first energy source configured to supply electrical power to the electric device; and a controller configured to: responsive to a first condition, direct the electrical power from the first energy source to the electric device for operation of the cooling system in an overcooling mode, wherein in the overcooling mode the electric device is powered to continue to cool a cooling element from below a designated maximum threshold temperature to a lower, second threshold temperature, wherein the cooling element is associated with the engine; determine a heat rejection rate between the cooling system and an external environment based on one or more characteristics of the cooling system and one or more conditions of the external environment; and responsive to a second condition, disable the overcooling mode, the second condition including a cooling cost of cooling the engine above a designated cooling cost threshold, the cooling cost determined based at least in part on the heat rejection rate.
10. 10. The vehicle of claim 9, wherein: the electric device of the cooling system comprises a radiator fan and a radiator fan motor coupled to the radiator fan for driving the radiator fan, and the cooling element is a cooling fluid in a fluid circuit associated with the engine and cooling system; the first energy source is a dynamic braking system configured to supply the electrical power to the radiator fan motor during a braking event; and the controller is configured to direct the electrical power from the dynamic braking system to the radiator fan motor to cool the cooling fluid to the second threshold temperature.
11. 11. The vehicle of claim 10, wherein the second threshold temperature is a predetermined minimum threshold temperature of the cooling fluid.
12. 12. The vehicle of claim 10 or 11, wherein the second threshold temperature is a lowest temperature to which the cooling fluid is cooled in the vehicle out of all operational modes of the vehicle.