Patent Publication Number: US-11649758-B1

Title: Systems and methods for control of engine cooling

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to methods and systems for internal combustion engine systems and, more particularly, to systems and methods for an internal combustion engine system with an air cooler. 
     BACKGROUND 
     Internal combustion engines are useful in various applications, including in machines, marine applications, and vehicles. These internal combustion engines generate significant quantities of heat during operation. To control this heat, engines are typically coupled to a cooling system that supplies coolant to the interior of the engine with the goal of maintaining the engine at suitable operating temperatures. In high-output internal combustion engine systems, cooling can also be provided to components other than the engine itself, such as air-supply components. These compressed-air cooling devices, such as aftercoolers, can reduce the temperature of air and further improve the efficiency and/or output of the engine. 
     Cooling systems for internal combustion engines include passages for circulating liquid coolant where needed. For example, engine systems for marine applications can include plural individual loops, each loop including a dedicated coolant-supplying pump. Thus, these systems include one pump that supplies coolant for the engine itself, and another pump that supplies coolant for another component of the engine system, such as an intercooler. While these systems can provide sufficient cooling capacity under some operating conditions, the use of separate individual pumps and fully-isolated loops involves the use of significant space and cost. For example, engine systems with multiple coolant loops employ mechanisms that transfer power from the engine to the coolant pumps, each coolant loop having a dedicated pump. However, some engines with space and/or design constraints are unable to accommodate individual engine-driven pumps. Even when engines systems are designed to accommodate individual coolant loops with separate pumps, the use of a dedicated pump for each loop increases the cost, size, and complexity of the system, while reducing efficiency due to increased parasitic load to drive each individual pump. 
     An engine system is described in U.S. Pat. No. 7,543,558 (“the &#39;558 patent”) to Buck. The system described in the &#39;558 patent includes a primary water pump that circulates water for cooling cylinders of an internal combustion engine, as well as a raw water pump for pumping from a body of water. The system of the &#39;558 patent includes multiple open flow paths for the raw water pump. While the system described in the &#39;558 patent may be useful for providing adequate engine cooling under some circumstances, it is not able to adjust a flow of coolant to a heat exchanger based on changing engine conditions. 
     The systems and methods of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem. 
     SUMMARY 
     In one aspect, a method for controlling an internal combustion engine cooling system may include pumping coolant in an engine cooling loop with a coolant pump, pumping the coolant in an air cooler loop that includes a liquid-to-liquid heat exchanger with the coolant pump, and receiving a condition signal indicative of at least one condition associated with the internal combustion engine. The method may also include, based on the condition signal, adjusting a position of a flow control valve to modify a flow of coolant to the liquid-to-liquid heat exchanger. 
     In another aspect, a method for controlling a cooling system for an internal combustion engine may include pumping coolant in a first closed loop and a second closed loop, the first and second closed loops being connected to each other and to a single coolant pump, the first closed loop including an air cooler and determining a condition associated with the internal combustion engine, including one or more of an engine speed condition, an engine output condition, an ambient temperature condition, or an emissions condition. The method may also include, in response to the determined condition, adjusting a position of a coolant flow valve positioned in the first closed loop. 
     In yet another aspect, an internal combustion engine cooling system may include an internal combustion engine, a single coolant pump in fluid communication with an engine cooling loop connected to provide coolant to the internal combustion engine and an air system cooling loop connected to provide the coolant to an air cooler, and a liquid-to-liquid heat exchanger configured to receive the coolant via the coolant pump. The system may also include a flow control valve connected downstream of the coolant pump as part of the air system cooling loop, the flow control valve being configured to modify a flow of the coolant from the engine cooling loop to the liquid-to-liquid heat exchanger based on one or more operating conditions of the internal combustion engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of an engine system, according to aspects of the disclosure. 
         FIG.  2    is a schematic diagram of an engine system applied in a marine vessel, according to aspects of the disclosure. 
         FIG.  3    is a block diagram of an electronic control module that may be used with an electronically-actuated flow valve, according to aspects of the disclosure. 
         FIG.  4    is a flowchart depicting an exemplary method for controlling an internal combustion engine cooling system, according to aspects of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “having,” including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a method or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a method or apparatus. In this disclosure, relative terms, such as, for example, “about,” “substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in the stated value or characteristic. While the term “seawater” is used herein for convenience, “seawater” is intended to encompass both saltwater (e.g., ocean water) and freshwater (e.g., lake water, river water, etc.). As used herein, “coolant” excludes seawater, but includes any suitable cooling fluid, such as fresh water (e.g., deionized water), propylene glycol, ethylene glycol, and others, including mixtures. 
       FIG.  1    illustrates an exemplary engine system  12  including an internal combustion engine  14  and an engine cooling system  50  for controlling temperatures during various operating conditions of engine  14 . In addition to engine  14  and cooling system  50 , system  12  may include a sensor system  70  for monitoring one or more aspects of system  12  and an electronic control module (“ECM”)  80  in communication with sensor system  70 . Cooling system  50  may include a plurality of paths for cooling engine  14  via a jacket water cooling system and for cooling other aspects of an operating engine system, such as engine oil, gear oil, air passing within an air cooler, etc., as shown in  FIGS.  1  and  2   . 
     Engine  14  may be a diesel fuel engine, gasoline engine, gaseous fuel engine, or dual fuel engine (an engine capable of generating power by combusting liquid fuel, such as diesel or gasoline, and gaseous fuel, such as natural gas). While engine  14  is shown as a twelve-cylinder engine having two rows of cylinders, engine  14  may have fewer cylinders, more cylinders, and/or a different arrangement of cylinders. Engine  14  may be configured to receive air via an intake system that includes an air intake  24 , a compressor  26 , a charge air cooler  28 , and an intake manifold  31 . While intake manifold  31  is represented with an arrow in  FIG.  1   , as understood, intake manifold  31  is connected to cylinders of engine  14  to provide intake air to individual cylinders of engine  14  via a plenum and plurality of runners in a known manner. The intake air for engine  14  may be compressed with air compressor  26  (e.g., a compressor of a turbocharger, a supercharger, etc.), this compressed air being supplied to engine  14  for combustion with fuel. While one engine  14  is shown in system  12 , as understood, a plurality of engines may be included in system  12 , these engines being connected to cooling system  50  as shown for engine  14 . 
     In the exemplary configuration shown in  FIG.  1   , cooling system  50  may include an air system cooling loop  54  and an engine system cooling loop  56 . Cooling loop  54  may be a first closed loop, while cooling loop  56  may be configured as a second closed loop. These two closed loops  54  and  56  may be connected to each other and may share a single pump. For example, with loops  54  and  56  connected to each other as shown in  FIG.  1   , cooling system  50  may include pump  32 , this pump  32  being operable to supply coolant to both closed loops  54  and  56 . Loops  54  and  56  may diverge from each other via branching passages or elbows connected directly to pump  32 , or connected downstream of pump  32 , such that a passage of loop  54  connects pump  32  to coolant a control valve  34  (described below), while a passage of loop  56  is connected upstream of engine  14 . Loops  54  and  56  may each include a component for reducing a temperature of coolant circulated within these loops, such as a jacket water heat exchanger  20  and an air cooler heat exchanger  22 . 
     Air system cooling loop  54  may include a path for supplying coolant to one or more components of an air system that guides compressed intake air to engine  14 . For example, air system cooling loop  54  may include air cooler heat exchanger  22 , charge air cooler  28 , a coolant pump  32 , and a flow-regulating valve  34 , also referred to herein as coolant control valve  34 . Heat exchanger  22  may be a liquid-to-liquid heat exchanger in which coolant in loop  54  is cooled using a second fluid circulated via a circuit  18 . If desired, jacket water heat exchanger  20  may also be a liquid-to-liquid heat exchanger in which coolant from loop  56  is cooled using a second fluid circulated in circuit  18 . While air cooler heat exchanger  22  and jacket water heat exchanger  20  are shown connected to the same circuit  18 , if desired, separate fluid circuits  18  may connect to air cooler heat exchanger  22  and jacket water heat exchanger  20 . However, if desired, one or both of heat exchangers  20  and  22  may be air-to-liquid heat exchangers (e.g., radiators) that employ the flow of air to cool coolant for loops  54  and  56 . 
     Air cooler heat exchanger  22  may be connected in loop  54  between flow-controlling valve  34  and charge air cooler  28 . Heat exchanger  22  may be a liquid-to-liquid heat exchanger that reduces a temperature of coolant supplied to charge air cooler  28 . Thus, coolant in loop  54  may form a first (cooled) liquid, while a separate fluid circuit  18  (dashed lines in  FIG.  1   ) includes a second liquid that absorbs heat from the first liquid. To enable heat exchange between coolant in loop  54  and fluid in circuit  18 , air cooler heat exchanger  22  may be a shell and tube heat exchanger, a plate type heat exchanger (e.g., a gasketed plate heat exchanger), or any other suitable type of heat exchanger. 
     Charge air cooler  28  may be connected downstream of air cooler heat exchanger  22  and upstream of coolant pump  32  in loop  54 . In particular, air cooler  28  may also be connected between control valve  34  and coolant pump  32 . Air cooler  28  may be an intercooler configured to cool intake air via heat exchange with coolant circulated in loop  54 . As shown in  FIG.  1   , air cooler  28  may be connected to air compressor  26  so that charge air cooler  28  receives compressed intake air via a compressed air passage  30  connected to an outlet of compressor  26 . An air outlet of air cooler  28  may be connected to engine  14  via intake manifold  31 . 
     Pump  32  may be connected between air cooler  28  and coolant control valve  34 , such that coolant is supplied to charge air cooler  28  via coolant control valve  34 , this coolant returning to pump  32  from air cooler  28 . With respect to loop  56 , pump  32  may be connected between engine  14  and engine oil cooler  36 , via a thermostat  38 . Pump  32  may be a tandem pump or any other appropriate type of pump having an output sufficient to drive a sufficient quantity of coolant fluid through loops  54  and  56 . 
     Coolant control valve  34  may be a two-way proportional valve having one inlet and one outlet, as represented by the solid line portions of valve  34  in  FIGS.  1  and  2   . In other configurations, valve  34  may be provided with a second outlet, represented by dashed lines in  FIGS.  1  and  2   , such that valve  34  is a three-way proportional valve. When valve  34  is a two-way valve, valve  34  may be positionable at a fully open position, a fully closed position, and a plurality of intermediate positions in which flow is partially restricted. When flow control valve  34  is a three-way valve having one inlet and two outlets, a bypass passage  35  may be connected to the second outlet, enabling fluid communication between valve  34  and charge air cooler  28  in a manner that bypasses air cooler heat exchanger  22 . This passage  35  may be omitted in two-way configurations of valve  34 . In the three-way configuration, valve  34  may have a first position that causes an entirety of the flow received by valve  34  to proceed to air cooler heat exchanger  22 , and a second position that causes an entirety of the flow received at valve  34  to bypass air cooler heat exchanger  22  via bypass passage  35 . Valve  34  may further include a plurality of third positions between these first and second positions. These third positions may cause some coolant to flow from valve  34  to air cooler heat exchanger  22  and some coolant to flow from valve  34  to air cooler heat exchanger  22 . 
     Whether valve  34  is a two-way valve or a three-way valve, valve  34  may be electronically-controlled, such that the position of valve  34  is set and adjusted with an actuator  60 . In an exemplary configuration, actuator  60  may be a solenoid actuator that selectively regulates a quantity of flow through air cooler heat exchanger  22 . This may be performed by restricting the amount of flow through valve  34  in two-way configurations, and/or by causing at least some flow through valve  34  to bypass air cooler heat exchanger  22  in three-way configurations. 
     Engine system cooling loop  56  may be connected in parallel to loop  54 . As shown in  FIG.  1   , engine system cooling loop  56  may connect pump  32  to engine  14  via an engine oil cooler  36 . Engine oil cooler  36  may be connected to an outlet of pump  32  to receive coolant via pump  32 , cool engine oil within cooler  36  via heat exchange, and provide this coolant to engine  14  via an outlet of cooler  36 . If desired, loop  56  may also include a bypass path (not shown) in which some coolant from pump  32  bypasses cooler  36  and is delivered to engine  14 . Coolant supplied to engine  14  via loop  56  may enter a water jacket of engine  14  (e.g., a sealed coolant path adjacent to cylinders of engine  14 , where the coolant receives heat from engine  14 ). 
     A thermostat  38  may be connected downstream of engine  14  to receive the coolant from engine  14 . Thermostat  38  may include a plurality of outlets, including a first outlet connected to jacket water heat exchanger  20 , and a second outlet connected to pump  32 . Thermostat  38  may be a mechanically-regulated valve configured to partially or fully close one of these outlets based on the temperature of the coolant exiting engine  14 . Thermostat  38  may define a plurality of coolant paths: a path in which coolant from thermostat  38  is provided to pump  32  via jacket water heat exchanger  20 , and another path in which coolant from thermostat  38  bypasses jacket water heat exchanger  20 . Thus, and as shown in  FIG.  1   , jacket water heat exchanger  20  may be connected between thermostat  38  and pump  32  in loop  56 . 
     Sensor system  70  may be configured to monitor aspects of system  12 , including one or more signals that may be useful for controlling valve  34  and for determining conditions of system  12  and engine  14 . Sensor system  70  may include at least one sensor in communication with ECM  80 , such as a heat exchanger temperature sensor  71  to measure a temperature of coolant entering and/or exiting heat exchanger  22 , an intake manifold sensor  72  configured to measure intake manifold temperature (“IMT”), intake manifold air pressure (“IMAP”), or both IMT and IMAP, a pump pressure sensor  73  configured to detect a pressure associated with pump  32 , an engine sensor  74  (e.g., an engine speed sensor, engine fuel sensor, etc.), a jacket water temperature sensor  75  configured to measure coolant temperature, and an ambient temperature sensor  76  configured to detect an ambient temperature associated with system  12 , such as a temperature outside of system  12  or around system  12 . The sensors of sensor system  70  may be configured to generate signals that are received by ECM  80  as inputs  310  ( FIGS.  1 - 3   ). While the sensors of sensor system  70  are shown at exemplary locations in  FIG.  1   , as understood, one or more of these sensors may be secured at a different position. For example, while jacket water temperature sensor  75  is shown at a position downstream of engine  14 , jacket water temperature sensor  75  may include one or more temperature sensors upstream of engine  14 , either instead of or in addition to the downstream position illustrated in  FIG.  1   . 
     ECM  80  may be enabled, via programming, to generate outputs (e.g., commands  352  for actuator  60 ) that control and adjust a position of coolant control valve  34  based on one or more conditions of system  12 . In particular, ECM  80  may be configured to identify one or more conditions associated with internal combustion engine  14  and determine one or more suitable temperature targets (values or ranges) for the operating condition, as described below. Commands  352  generated with ECM  80  may adjust the position of valve  34  so as to modify the proportion of coolant that passes through air cooler heat exchanger  22  and thereby seek a temperature target at one or more other locations of system  12 . 
     ECM  80  may be a control unit for controlling internal combustion engine  14  (e.g., by issuing commands to one or more fuel injectors), or may be a separate control unit that is dedicated for monitoring and controlling system cooling. If desired, ECM  80  may be in communication with one or more additional electronic control modules, including a supervisory control module, a control module for a transmission system, or a control module that controls fuel injectors of engine  14 . ECM  80  may embody a single microprocessor or multiple microprocessors that receive inputs  310  and generate outputs  350  ( FIG.  3   ). ECM  80  may include a memory, a secondary storage device, a processor such as a central processing unit, or any other means for accomplishing a task consistent with the present disclosure. The memory or secondary storage device associated with ECM  80  may store data and software to allow ECM  80  to perform its functions, including the condition module  330  and valve position selector  340  functions described with respect to  FIG.  3    and one or more steps of method  400  described below. Numerous commercially available microprocessors can be configured to perform the functions of ECM  80 . Various other known circuits may be associated with ECM  80 , including signal-conditioning circuitry, communication circuitry, and other appropriate circuitry. 
       FIG.  2    illustrates an embodiment of engine system  12  in which system  12  is utilized in a marine vessel such as a ship  110 . Ship  110  may be, for example, a tugboat, a cargoship or freighter, a yacht, a fishing boat, a passenger boat (e.g., a ferry), a patrol or emergency response boat, or any other type of recreational or commercial boat. In addition to the components described above with respect to  FIG.  1   , system  12  may include components suitable for use in a marine environment. For example, system  12  may include a seawater supply  150  forming one or more open-loop circuits that can supply cooling seawater to a fuel cooler  124 , and gear oil cooler  126 , as well as to jacket water heat exchanger  20  and air cooler heat exchanger  22 . An outlet  158  may provide a path for seawater to exit system  12 . Ship  110  may also include a propulsion device  142  connected to engine  14  via a coupling  140 . Coupling  140  may include one or more flywheels, gearboxes, clutches, couplings, and/or transmission shafts, in a known manner. Ship  110  may also include one or more internal combustion engines  14  used as part of a generator set (not shown), a system which is not connected to a propulsion device  142  and that includes a generator in combination with engine  14 . 
     In the exemplary configuration shown in  FIG.  2   , cooling system  50  includes seawater supply  150  represented with dashed lines, air system cooling loop  54 , and engine system cooling loop  56 . In this configuration, cooling system  50  may include no more than two pumps, a pump that supplies seawater (e.g., pump  118  of the open loop formed by seawater supply  150 ), and a pump that supplies coolant (e.g., pump  32  of loops  54  and  56 ). Moreover, the fluid supplied by these pumps  32  and  118  does not mix such that coolant within the closed loops  54  and  56  may be isolated from seawater in supply  150 . 
     Seawater supply  150  of cooling system  50  may include a plurality of parallel paths configured to receive fluid, such as seawater, and pass this seawater through heat exchangers to draw heat away from coolant and from one or more components of engine system  12 . Seawater supply  150  may include a water intake  116  configured to connect a seawater pump  118  to a source of water (e.g., a body of water in which ship  110  is floating). Seawater pump  118  may include one or more outlets that supply this seawater to fuel cooler  124 , gear oil cooler  126 , jacket water heat exchanger  20 , and air cooler heat exchanger  22 . This cooling seawater, after passing through one or more of these components, may exit ship  110  via ship outlet  158 . While a single outlet  158  is shown in  FIG.  1   , as understood, ship  110  may include two more outlets  158 , each path of seawater supply  150  including one or more individual outlets  158  to facilitate efficient routing of seawater supply  150 . 
     A first path of seawater supply  150  may include water intake  116 , pump  118 , fuel cooler  124 , gear oil cooler  126 , and outlet  158 . Fuel cooler  124  may include a heat exchange device in which fuel (e.g., fuel returning to a fuel tank from engine  14 ) is cooled by seawater pumped via seawater pump  118 . Another heat exchange device, gear oil cooler  126 , may be connected downstream of fuel cooler  124 , or alternatively, in parallel with or downstream of fuel cooler  124 . Gear oil cooler  126  may be configured to cool oil for one or more transmission components (e.g., a gearbox of coupling  140 ) with seawater delivered via water pump  118 . 
     A second path of seawater supply  150  may provide a flow of seawater to a cooling device associated with engine  14 . This path of seawater supply  150  may include water intake  116 , seawater pump  118 , heat exchanger  20 , and outlet  158 . Seawater may enter an inlet of jacket water heat exchanger  20 , absorb heat from engine coolant passing within jacket water heat exchanger  20 , and exit jacket water heat exchanger  20 . Seawater that exits heat exchanger  20  may be removed from ship  110  via outlet  158 . 
     A third path of seawater supply  150  may connect seawater pump  118  to air cooler heat exchanger  22 . This third path may include water intake  116 , seawater pump  118 , air cooler heat exchanger  22 , and outlet  158 . Air cooler heat exchanger  22  may include a seawater inlet connected to seawater pump  118  and an outlet for seawater connected to ship outlet  158 . 
       FIG.  3    is a block diagram of an exemplary configuration of ECM  80  that may enable functions for controlling cooling of engine  14  according to one or more different conditions of system  12 . ECM  80  may receive inputs  310 , generate one or more outputs  350 , with one exemplary output  352  being shown. ECM  80  may include (e.g., ECM  80  may be programmed with) a condition module  130  configured to evaluate conditions of system  12  based on one or more inputs  310  and a valve position selector  340  configured to generate valve commands  352  based on the conditions identified with conditions module  130 . 
     The inputs  310  received by ECM  80  may include signals from sensor system  70 . Inputs  310  may also include one or more calculated values, if desired. As shown in  FIG.  3   , inputs  310  may include an engine speed signal  312 , an engine output signal  314 , an environment temperature signal  316 , an engine coolant temperature signal  318 , a heat exchanger temperature signal  320 , an intake air temperature signal  322 , and a pump pressure signal  324 . 
     Engine speed signal  312  may be a signal generated by engine sensor  74  ( FIGS.  1  and  2   ) that represents a detected speed of engine  14 . In particular, engine speed signal  312  may represent a detected speed and/or detected position of a crankshaft or other output shaft connected to engine  14 . Engine output signal  314  may be a calculated or detected value representing torque or power output of engine  14 . This engine output may be determined based on an amount or pressure of air supplied to engine  14  (as measured with intake manifold sensor  72 ), a quantity or pressure of fuel supplied to engine  14  (calculated based on fuel injector commands and/or one or more sensors associated with a fuel delivery system), and/or the speed of engine  14  represented by engine speed signal  312 . Environment temperature signal  316  may represent an ambient temperature of the geographic location of system  12  generated with ambient temperature sensor  76 . In configurations where system  12  is adapted for a marine vessel, temperature signal  316  may indicate a temperature of a body of water or a temperature at a body of water. Engine coolant temperature signal  318  may represent a temperature of coolant in loop  56  and may be generated by jacket water temperature sensor  75 . Heat exchanger temperature signal  320  may be generated by heat exchanger temperature sensor  71 , and may indicate the temperature of coolant supplied to heat exchanger  22 , and in particular, the temperature of coolant at an inlet of heat exchanger  22 . Intake air temperature signal  322  may represent the temperature of compressed air supplied to engine  14  (e.g., downstream of a compressor and downstream of charge air cooler charge air cooler  28 ), as measured with intake manifold sensor  72 . Pump pressure signal  324  may represent a pressure of pump  32 , and in particular, a pressure difference between an inlet of pump  32  and an outlet of pump  32  (e.g., inlets and outlets of pump  32  for loops  54  and/or  56 ). 
     Condition module  330  may be configured to determine one or more types of conditions associated with system  12  and engine  14 . The condition(s) identified with condition module  330  may depend on the particular configuration of system  12  (e.g., whether system  12  is placed on a stationary machine, mobile machine, vehicle, or marine vessel). In the example of a vehicle or machine (e.g., an earthmoving machine, off-highway truck, material loaders, etc.), condition module  330  may be configured to determine engine speed conditions and engine output conditions. In the example of a marine vessel such as ship  110 , condition module  330  may be configured to determine ambient temperature conditions or emissions conditions, instead of or in addition to engine speed conditions and engine output conditions. However, it is also contemplated that a vehicle or machine may also include a condition module  330  configured to determine ambient temperature and emissions conditions. The conditions determined with module  330  may be output to valve positon selector  340  and used to generate valve command  352 . 
     An engine speed condition determined with condition module  330  may indicate whether the current engine speed signal  312  indicates a low speed condition (e.g., an engine speed that is equal to or lower than a first predetermined speed), a high speed condition (e.g., an engine speed that is equal to or higher than a second predetermined speed, the second predetermined speed being faster than the first predetermined speed), or a moderate speed condition (e.g., an engine speed between the first and second predetermined speeds). The engine speed may correspond to a speed of a crankshaft of engine  14 . In some aspects, the high engine speed may be approximately equivalent to the rated engine speed of engine  14 . 
     When an engine output condition is determined with module  330 , this condition may indicate whether the current output of engine  14  is high, moderate, or low, based on low and high predetermined thresholds, in a similar manner as described above with respect to engine speed conditions. The engine output may correspond to torque generated with engine  14  or a power generated with engine  14 . In some aspects, the high engine output may be approximately equivalent to the rated, or maximum, output (power or torque) of engine  14 . 
     When condition module  330  determines an ambient temperature condition, this condition may correspond to whether the current temperature (e.g., a temperature indicated by environment temperature signal  316 ) corresponds to a standard or typical day-time temperature, a low ambient temperature, or a high ambient temperature. The low ambient temperature condition may correspond to temperatures below a low temperature threshold, while the high ambient temperature condition may correspond to temperatures above a high temperature threshold. 
     In aspects where condition module  330  determines an emissions condition, this condition may correspond to a reduced-emissions mode or a normal mode. In some aspects, the emissions condition may correspond to a manual or automated request for reduced emissions. The reduced emissions mode may be suitable for marine applications of system  12  (e.g., ship  110 ) where emissions requirements may change according to the location of system  12 . For example, ECM  80  may receive a request for reduced emissions when system  12  is located within a particular distance of a port. 
     Valve position selector  340  may receive one or more of the above-described conditions determined with condition module  330 . Valve position selector  340  may also be configured to determine one or more target temperatures that are appropriate for the received conditions. For example, valve position selector  340  may determine temperature targets, in the form of either a particular temperature or range of temperatures for one or more of: internal combustion engine  14 , intake manifold, or coolant between engine  14  and pump  32 . If desired, valve position selector  340  may also be configured to set one or more flow targets, such as a flow rate of coolant through engine  14 . 
     The target temperature(s) set with valve position selector  340  may be lower for determined conditions that are associated with lower engine speed, lower output, and/or lower ambient temperatures. While the target temperature may be set based on a single condition, the target temperature may be set by taking into account multiple determined conditions. In one example, an IMT target may be set based on engine speed, engine power, and ambient temperature conditions, with lower engine speeds, lower engine powers, and lower ambient temperatures acting to decrease the IMT target, while higher engine speeds, higher engine powers, and higher ambient temperatures increase the IMT target. ECM  80  may be configured to determine whether a temperature target is satisfied based on feedback information from signals  318 ,  320 , and  322 . When a flow target is set with ECM  80 , pump pressure  324  may provide feedback information to assist ECM  80  in determining whether the flow target is satisfied. 
     Valve position selector  340  may be able to determine an appropriate position for valve  34 , and generate commands  352  for actuator  60 . These commands may be based on the condition determined with module  330  and, in particular, may seek to achieve the above-described targets. Valve position selector  340  may generate bypass valve command  352  to adjust the position of valve  34  by controlling an amount of electrical energy supplied to actuator  60 , this position controlling the amount of coolant that enters heat exchanger  22  and thereby controlling the temperature of components cooled by loops  54  and  56 . Bypass valve command  352  may control the amount of current supplied to a solenoid of actuator  60 , a duty cycle of energy supplied to this solenoid, or both, such that valve  34  enters a desired position based on the above-described temperature target(s). 
     In some aspects, the valve command  352  generated with valve position selector  340  may cause valve  34  to be in a “fully open” position in which no coolant bypasses heat exchanger  22  when the engine speed condition or the engine output condition is high, thereby maximizing cooling. When engine speed and engine output are both low, valve position selector  340  may cause valve  34  to be in a “fully closed” position in which substantially no coolant is provided to heat exchanger  22 . When engine speed and engine output conditions are both moderate or low, the valve command  352  determined with position selector  340  may be adjusted based on the ambient temperature condition, the emissions condition, or both. 
     INDUSTRIAL APPLICABILITY 
     Engine system  12  may be useful in any machine, vehicle, or marine vessel (e.g., ship  110 ) having an internal combustion engine, where it is desirable to control cooling of one or more system components based on changing operating conditions. Engine system  12  may be useful to control engine cooling in a manner that accounts for various conditions that occur in mobile or stationary machines, vehicles, and/or marine vessels. In particular, engine system  12  may be useful for controlling cooling in systems  12  that include an engine coolant loop and an air cooler coolant loop, coolant being driven through these loops by a single pump. 
       FIG.  4    is a flowchart illustrating an exemplary method  400  for controlling a cooling system, such as cooling system  50 , associated with internal combustion engine  14 , according to aspects of the present disclosure. Method  400  may be performed while operating engine  14  to generate propulsion or electrical power for ship  110 , a mobile machine, or a vehicle. Method  400  may also be performed when system  12  is employed in a stationary power generation configuration. Method  400  may be performed continuously during the operation of system  12 , or in response to a particular condition or to condition changes. 
     A step  402  of method  400  may include pumping, with pump  32 , coolant in a first closed loop, such as loop  56 , for supplying this coolant to internal combustion engine  14 . The coolant may pass through engine oil cooler  36 , or may bypass engine oil cooler  36  via a bypass passage (not shown), and may be received within an interior of engine  14 . For example, a block of engine  14  may include a water jacket, such that the coolant flows through this jacket and adjacent to one or more cylinders of engine  14 . The coolant may return to pump  32  via thermostat  38 , either through a path that includes jacket water heat exchanger  20  or a path that bypasses jacket water heat exchanger  20 . The path by which coolant returns to pump  32  may depend on the temperature of the coolant. For example, when coolant has a relatively low temperature, thermostat  38  may cause coolant to return directly to pump  32 . However, when coolant exiting engine  14  has a relatively high temperature, some or all of this coolant may be directed, via thermostat  38 , to jacket water heat exchanger  20 , where the coolant is cooled via heat exchange with a second fluid (e.g., seawater circulated in seawater supply  150 , as represented with dotted lines in  FIG.  2   ). 
     A step  404  may include pumping coolant in a second loop, such as loop  54 , with pump  32 . Pumping coolant in loop  54  may supply coolant to a system that guides air (e.g., compressed air) to engine  14 . This coolant may be the same as the coolant that is pumped with pump  32  in step  402 . Thus, steps  402  and  404  may include pumping coolant with a single pump, such that the engine system  12  includes exactly one coolant pump for the closed-circuit coolant loops for engine  14  and air cooler  28 . Step  404  may also include supplying this coolant to bypass valve  34 . 
     A step  406  may include receiving condition signals and determining conditions associated with system  12  based on the received signals. For example, condition module  330  may determine one or more of an engine speed condition, an engine output condition, an ambient temperature condition, or an emissions condition, as described above. The conditions determined in step  406  may be based on sensor signals and/or calculated values, such as engine speed signal  312 , engine output signal  314 , and environment temperature signal  316 . In step  406 , condition module  330  may determine whether engine speed or engine power is high (e.g., approximately equal to the rated speed or power of engine  14 ), moderate, or low, as described above. When ambient conditions are determined in step  406 , condition module  330  may determine whether the ambient temperature corresponds to typical daytime ambient temperatures or whether the temperature is lower or higher than typical ambient daytime temperatures. 
     Step  408  may include operating valve  34  in response to the determination performed in step  406 . In particular, step  408  may include setting or adjusting a position of flow control valve  34  based on the condition signal received in step  406 . Step  408  may include generating a command valve command  352  to control a state of actuator  60 . 
     The adjusted position of valve  34  may be based on the engine speed condition, engine output condition, ambient temperature condition, emissions condition, or any combination of these conditions. In some aspects, the adjusted position of valve  34  may reflect all of these conditions, with the engine speed and engine output conditions having the greatest impact on command  352 . For example, when engine speed and/or engine output is high, the ambient temperature condition and/or emissions condition may be ignored and valve  34  may be set to a fully-open position in which no flow bypasses heat exchanger  22 . 
     In conditions when engine speed and engine output are each moderate or low, the ambient temperature condition, emissions condition, or both, may be used to further adjust command  352 . For example, if engine speed and/or engine output are both moderate and ambient temperature is moderate, valve  34  may be set to a position where approximately 50% of the flow of coolant bypasses heat exchanger  22 , while the remaining 50% of flow is directed to heat exchanger  22 . In conditions where engine speed and/or engine output are both moderate and ambient temperature is high, valve  34  may be set to a position where approximately 25% of the coolant bypasses heat exchanger  22 , while the remaining approximately 75% of the coolant is directed to heat exchanger  22 . When engine speed, engine output, and ambient temperature are all low, valve  34  may be fully closed such that no coolant is directed to heat exchanger  22 . 
     Command  352  may also be adjusted in a manner that is expected to reduce emissions produced by engine  14  when ECM  80  receives a request to enter a reduced emissions mode. For example, command  352  may be adjusted to increase a flow of coolant to heat exchanger  22  when increased cooling will result in improved emissions performance of engine  14 . 
     While steps  402 ,  404 ,  406 , and  408  have been described in an exemplary sequence, as understood, one or more of these steps may be performed simultaneously or performed and/or repeated in a different order. Moreover, any two or more of these steps may be performed simultaneously and/or at overlapping periods of time. In embodiments where valve  34  is a two-way valve, the above-described exemplary positions of valve  34  may be employed to adjust the flow of coolant to heat exchanger  22  when desired, without causing coolant to bypass heat exchanger  22  due to the omission of a second outlet and/or bypass passage  35 . For example, rather than causing 25% of coolant to bypass heat exchanger  22 , valve  34  may instead restrict flow rate by a corresponding amount (e.g., 25%). 
     System  12  and method  400  may be useful for various types of internal combustion engines  14 . In particular, system  12  and method  400  may provide coolant flow to both a jacket water system and a separate circuit after cooler system via respective closed coolant loops and a single pump. System  12  and method  400  may further facilitate control over system temperatures under different operating conditions. This control may improve control over emissions and improve compensation for ambient conditions, such as ambient temperature. Additionally, the use of a single pump for both engine and air cooler circuits may reduce cost, system complexity, and space requirements. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system and method without departing from the scope of the disclosure. Other embodiments of the system and method will be apparent to those skilled in the art from consideration of the specification and system and method disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.