Patent Application
20150345370
The present disclosure relates generally to a cooling control system, and more particularly, to a cooling control system for a mobile machine.
Mobile machines operate in environments that can change dramatically within a relatively short period of time. For example, during a single trip between destinations, a locomotive can operate in an open environment and, at select times during the trip, in a closed environment such as in a tunnel When the locomotive operates in the open environment, the locomotive is provided with an adequate amount of relatively cool air that is used for both combustion and for cooling engines and electronics of the locomotive. When the locomotive operates in the closed environment, the amount of available air can be less and/or the temperature of the air can be higher. In addition, when a locomotive operates at high altitude (e.g., when navigating a mountain pass), the amount of available air can be less. For this reason, in the closed environments or at high altitude, performance of the locomotive can diminish naturally through overheating of the engine and/or electronics, or the locomotive may be purposely derated to protect components of the locomotive from overheating.
One attempt to improve cooling of a locomotive in a closed environment is described in U.S. Pat. No. 5,561,602 (“the '602 patent”) of Bessler that issued on Oct. 1, 1996. The '602 patent describes a locomotive having a liquid-cooled engine and an air-cooled controller. The '602 patent also describes a tunnel indicator that can be initiated either manually by an operator, or automatically by a GPS system. When the tunnel indicator initiates a tunnel operation, for example at a location one or two miles before a tunnel, the controller activates a blower to operate at full speed and maximize cooling of the controller prior to entering the tunnel Likewise, the controller causes a heat exchanger motor to operate at full speed in order to increase cooling of the engine before entering the tunnel. This pre-cooling effectively increases the tolerance of the locomotive to thermal overload, maximizing the time that the locomotive can spend in the tunnel without adverse consequences.
Although the system of the '602 patent may be capable of increasing the operating limits of a locomotive within a tunnel, it may still be less than optimal. Specifically, the system of the '602 patent requires either manual activation, which can be prone to operator error, or GPS activation, which can be susceptible to loss of signal or discrepancy in the locomotive position versus the GPS tunnel indicator trigger position.
The cooling control system of the present disclosure solves one or more of the problems set forth above and/or other problems with existing technologies.
In one aspect, the present disclosure is directed to a cooling control system for a mobile machine having an engine. The cooling control system may include a circuit fluidly connected to the engine, and a heat exchanger configured to dissipate heat from coolant in the circuit. The cooling control system may also include a fan disposed proximate the heat exchanger, a thermostat configured to selectively allow coolant through the heat exchanger, and a locating device configured to generate a location signal indicative of a location of the mobile machine. The cooling control system may further include a pressure sensor configured to generate a pressure signal indicative of a barometric pressure in proximity to the mobile machine, and a controller in communication with the fan, the thermostat, the locating device, and the pressure sensor. The controller may be configured to selectively activate the fan and cause the thermostat to move to an increased cooling position when the location signal indicates the mobile machine is within a threshold area of a geological feature known to increase a temperature of the engine, and to selectively activate the fan and cause the thermostat to move based on the pressure signal when the location signal from the locating device is unavailable.
In another aspect, the present disclosure is directed to a method of cooling a mobile machine having an engine. The method may include receiving a location signal indicative of a location of the mobile machine, and determining a barometric pressure in proximity to the mobile machine. The method may also include selectively increasing cooling of the engine when the location signal indicates that the mobile machine is within a threshold area of a geological feature known to increase a temperature of the engine, and selectively increasing cooling of the engine based on the barometric pressure when the location signal is determined to be unavailable.
In another aspect, the present disclosure is directed to a mobile machine. The mobile machine may include a frame, an engine mounted to the frame, and wheels configured to support the frame. The mobile machine may also include a circuit fluidly connected to the engine, a heat exchanger configured to dissipate heat from coolant in the circuit, and a fan disposed proximate the heat exchanger. The mobile machine may further include a thermostat configured to selectively allow coolant through the heat exchanger, a locating device configured to generate a location signal indicative of a location of the mobile machine, and a pressure sensor configured to generate a pressure signal indicative of a barometric pressure in proximity to the mobile machine. The mobile machine may also include a controller in communication with the fan, the thermostat, the locating device, and the pressure sensor. The mobile machine may further include wherein the controller is configured to selectively activate the fan and cause the thermostat to move to maximum cooling position when the location signal indicates the mobile machine is within a threshold area of a tunnel, and selectively activate the fan and cause the thermostat to move based on the pressure signal when the signal from the locating device is unavailable.
Heat exchanger 220 may function as the radiator used to cool engine 140 (as well as power electronics of machine 100 not shown). Heat exchanger 220 may be a liquid-to-air type of heat exchanger. That is, a flow of air may be directed through channels of heat exchanger 220 by fan 230, such that heat from coolant within adjacent channels is transferred to the air. In this manner, the coolant passing through engine 140 may be cooled and maintained at an allowable operating temperature range. Fan 230 may be associated with heat exchanger 220 and configured to generate the flow of cooling air. Fan 230 may include a single fan or multiple fans. Fan 230 may include a driver device (not shown) such as a belt-driven pulley, a hydraulically-driven motor, or an electrically-powered motor that is configured to drive the rotation of fan 230. Cooling control system 160 may further include a heat exchanger sprayer 221 associated with heat exchanger 220 and configured to spray a liquid on to heat exchanger 220 to enhance cooling.
Flow control device 242 may be a proportional type valve having a valve element movable to regulate a flow of coolant. The valve element may be solenoid-operable to move between a flow-passing position and a flow-blocking position. In the flow-passing position, flow control device 242 may permit substantially all of the coolant to flow through passage 214 and engine 140. In the flow-blocking position, flow control device 242 may substantially block coolant from flowing to engine 140. Flow control device 242 may also include an intermediate position between the flow-passing position and the flow-blocking position. In the intermediate position, flow control device 242 may permit some of the coolant to flow through passage 214 to engine 140. While flow control device 242 is described as being a proportional-type valve, a plurality of throttle-type valves (not shown) may alternatively be utilized. Thermostat 240 can be configured to control the operation of flow control device 242. Thermostat 240 may be, for example, an electronic, digital, analog, or other type of thermostat. It is also contemplated that pump 290 could be used to control the flow of coolant through passages 212 and 214 to engine 140 by varying the speed of pump 290. Thermostat 240 may be configured to control both pump 290 and flow control device 242, or control pump 290 could be independently controlled. For example, the speed of pump 290 may correspond with the speed (e.g., rotation per minute) of engine 140, such that setting engine 140 to maximum speed increases the speed of pump 290 to maximum speed.
Cooling control system 160 may further include a locating device 250, a pressure sensor 260, and a controller 270. Thermostat 240 can be in communication with controller 270 and configured to receive a thermostat signal 241 from controller 270 configured to move the cooling position of thermostat 240. Locating device 250 may be a global positioning system (GPS) receiver, cellular receiver, or other like receiver, or combination thereof configured to identify the location of mobile machine 100. For example, locating device 150 may include a receiver configured to receive a transponder signal from a track side transponder. Track side transponders may be positioned before and after a geological feature. Locating device 250 can be in communication with controller 270 and may also be configured to generate a location signal 251 indicative of a location of the mobile machine 100, and send that signal to controller 270. Location signal 251 may comprise, for example, a longitude, a latitude, and an altitude of mobile machine 100.
Pressure sensor 260 may be, for example, a barometric pressure sensor configured to detect the barometric pressure in proximity to mobile machine 100. Pressure sensor 260 may be configured to detect a barometric pressure of the atmosphere at an intake to engine 140. Pressure sensor 260 can be in communication with controller 270 and configured to generate a pressure signal 261 indicative of a barometric pressure in proximity to mobile machine 100.
Electrical compartment 150 may further include a blower 151 configured to cool the various components within electrical compartment 150. Electrical compartment 150 and blower 151 can be in communication with controller 270. Controller 270 can be configured detect the temperature within electrical compartment 150 and control operation (e.g., on/off and/or speed) of blower 151.
Controller 270 may be a single microprocessor or multiple microprocessors that includes a mechanism for controlling an operation of cooling control system 160. Numerous commercially available microprocessors can be configured to perform the functions of controller 270. It should be appreciated that controller 270 could readily be embodied in a general mobile machine microprocessor capable of controlling numerous engine and/or machine functions. Controller 270 may include a memory, a secondary storage device, a processor, and any other components for running an application. Various other circuits may be associated with controller 270 such as power supply circuitry, signal conditioning circuitry, solenoid driver circuitry, and other types of circuitry.
Mobile machine 100 may further include a speedometer 273 and a throttle controller 274. Speedometer 273 can be configured to detect a track speed of mobile machine 100 and transmit a track speed signal 271 to controller 270 indicative of the track speed of mobile machine 100. Throttle controller 274 can be configured to detect a throttle position of mobile machine 100 and transmit a throttle position signal 272 to controller 270 indicative of the throttle position of mobile machine 100. In other embodiments, track speed signal 271 and throttle position signal 272 may be transmitted by a main system controller in communication with the throttle and speedometer.
Mobile machine 100 may further comprise a plurality of sensors configured to detect various environmental conditions and transmit signals to controller 270. For example, the plurality of sensors may detect ambient humidity, ambient temperature, ambient wind speed, or other environmental conditions.
It is contemplated that mobile machine 100 may further include a variety of other cooling mechanisms and apparatuses for cooling electrical and mechanical equipment not specifically described herein and controller 270 may be configured to control such cooling mechanisms similarly to those described herein.
The disclosed cooling control system may be applicable to any mobile machine required to operate in varying temperature and atmospheric conditions as a result of a geological feature, such as a tunnel or a high altitude mountain peak. The disclosed cooling control system may enhance mobile machine cooling by controlling one or more of the following: fan operation, thermostat setting, blower operation, coolant pump speed, and heat exchanger sprayer of the cooling system preemptively before arriving at the geological feature and while exposed to the geological feature. Exemplary embodiments of operation of cooling control system 160 will now be described, with respect to
For both embodiments represented in
Controller 270 could make this determination by, for example, comparing the longitude and latitude of location signal 251 versus a longitude and latitude value that corresponds to a threshold distance from a geological feature. However, comparing the longitude and latitude of location signal 251 to the longitude and latitude value of a signal point determined to indicate the threshold distance from a geological feature can lead to issues caused by the margin of error between the values. The margin of error could result in mobile machine 100 passing the signal point for the threshold distance without the longitude and latitude values ever sufficiently equaling the longitude and latitude values of location signal 251. As a result, mobile machine 100 could proceed past the signal point for the geological feature without satisfying the condition of step 304.
To prevent this, controller 270 can be configured to compare the longitude and latitude of location signal 251 to not just a single signal point, but instead to an area defined by a plurality of longitude and latitude points. The plurality of points can correspond to an area surrounding a geological feature. The plurality of points of the threshold area for a geological feature can be stored as a data set in the form of, for example, a data table, lookup table, database or the like.
According to an exemplary embodiment, the threshold area can cover the entire geological feature and a surrounding zone. For example, the threshold area can start a threshold distance prior to the geological feature along the route and can extend beyond the geological feature along the route. The shape of the threshold area can vary. For example, the area can be a square, rectangle, circle, quadrilateral, oval, triangle, trapezoid, or an abnormal shape. Track side transponders may be positioned to correspond to the start and finish of a threshold area along a route of mobile machine 100.
The configuration of the threshold area can be unique for each geological feature. For example, for a longer geological feature, such as a tunnel, the threshold area may be greater than for a shorter tunnel; for a higher altitude tunnel, the threshold area may be greater than for a lower altitude tunnel; or for a geological feature that has a steep grade, the threshold area may also be greater than that of a less steep grade. Additionally, the threshold area can be generated based on unique characteristics of mobile machine 100 and/or operating conditions of mobile machine 100. For example, the threshold area can be varied based one or more of the following characteristics of mobile machine 100, such as a length, a weight, a power of mobile machine, a load on mobile machine, a speed, an operating temperature, a cooling capacity, etc.
Controller 270 may be configured to compare the location signal 251 to threshold areas along the route. It is also contemplated that, rather than doing a point-to-point comparison of longitude and latitude values of location signal 251 to the longitude and latitude of each point of a data set, values of location signal 251 could be input into a function block that compares both the longitude and latitude values to a range (e.g., greater than x longitude/latitude, but less than y longitude/latitude) where the limits of the ranges correspond to the outer limits (e.g., corners) of the area.
It is also contemplated that a distance from the start of the geological feature to the outer limit of the threshold area along the mobile machine's route of travel can correspond with a time needed to reduce coolant and engine temperatures to a low system temperature setpoint. For example, the threshold area can be determined such that the distance to the outer edge of the threshold area along the mobile machine route is about one mile, which based on the mobile machines track speed should enable sufficient time for a coolant temperature of mobile machine 100 to drop from about 85° C. to about 80° C.
At step 304, if controller 270 determines that mobile machine 100 is not within the threshold area of a geological feature, then controller 270 can return to step 300 where a tunnel mode decision logic is enabled and the determination logic can be repeated. At step 304, if controller 270 determines that mobile machine 100 is within the threshold area of a geological feature, then controller 270 can proceed to step 312, where controller 270 can initiate the tunnel mode of operation. At step 312, steps 302 and 304 may become latched, such that if mobile machine 100 enters a tunnel causing loss of locating signal 251, the tunnel mode may remain operational.
According to the embodiment of
Thermostat 240 may be moved to the maximum cooling position by adjusting a threshold thermostat temperature to a minimum setpoint, for example, from about 85° C. to about 80° C., or less. As described herein, at a maximum cooling position, flow control device 242 can be configured to allow maximum circulation of coolant through circuit 210. By allowing maximum circulation of coolant through circuit 210 at a distance before a tunnel, temperatures of the coolant and engine 140 can begin to fall before mobile machine 100 reaches the tunnel Controller 270 can be configured to continue chilling the coolant and engine 140 until the temperature of engine 140 reaches a minimum operating temperature setpoint, at which point circulation of coolant can be adjusted by flow control device 242 to maintain the minimum operating temperature setpoint. Pump 290 may be moved to the maximum pumping position by increasing the rotations per minute of engine 140 and thereby increasing the speed and output of pump 290.
Steps 314 and 316 of
According to the embodiment of
If the position of mobile machine 100 is no longer within the threshold area corresponding to the geological feature, then controller 270 can proceed to step 320 where it can be determined whether throttle position signal 272 is less than a throttle setpoint for a set period or track speed signal 271 is greater than a track speed setpoint for a set period. The throttle setpoint and the track speed setpoint can be specific to a geological feature and/or a mobile machine. Checking the throttle position or track speed of mobile machine 100 after exiting the geological feature can confirm mobile machine 100 is capable of operating within the normal limits of cooling control system 160 with tunnel mode turned off. Confirming such after exiting a geological feature can be advantageous because often the grade of the track following a geological feature (e.g., a tunnel) can remain steep or increase such that the load on mobile machine 100 can still be beyond the normal limits of cooling control system 160 despite exiting the geological feature. Therefore, confirming throttle position signal 272 is less than the throttle setpoint can provide verification that the load on engine 140 has been reduced, resulting in a reduction in heat generated capacity of engine 140. Similarly, confirming track speed signal 271 may be greater than the track speed setpoint may verify that the speed of mobile machine 100 is such that the load has been reduced sufficiently to enable adequate cooling and temperature control of engine 140. In addition, if a geological feature has a reduced track speed limit, the track speed setpoint can be set to a value above the track speed limit for the geological feature, enabling the comparison of track speed signal 271 to the track speed setpoint to be a way of confirming mobile machine 100 is beyond the reduced speed area of the geological feature.
At step 320, if throttle position signal 272 is greater than the throttle setpoint and track speed signal 271 is less than the track speed setpoint, controller 270 may conclude that tunnel mode is still necessary to adequately cool engine 140 and, therefore, return to step 314 to repeat the logic. By repeating the logic, fan 230 can stay running and thermostat 240 can stay at maximum cooling position until mobile machine 100 is both out of the threshold area corresponding to the geological feature and mobile machine 100 is operating under conditions that enable temperature control of engine 140 without overheating.
At step 320, if either or both conditions are met, controller 270 can proceed to step 322, where tunnel mode is stopped. Thereafter, controller 270 can return to step 300. At this point in time, operation of fan 230 and thermostat 240 may return to normal.
According to the embodiment of
Referring back to step 317B, if location signal 251 is unavailable, controller 270 can proceed to step 319. At step 319 it can be determined whether the transponder signal has been received by locating device 250 or whether the transponder signal has been manually activated. The transponder signal may correspond to the transponder positioned at about the end of the geological feature. If either the transponder signal has been received or manually activated, controller 270 can proceed directly to step 322, where tunnel mode is stopped. If neither the transponder signal has been received nor manually activated, controller 270 can proceed to step 320 and execute the determination of step 320 as described above with regard to the embodiment of
Referring back to step 302 of
If track speed signal 271 is less than the track speed setpoint, then controller 270 can proceed to step 308 where it can be determined whether throttle position signal 272 is equal to a throttle position setpoint range. The throttle position setpoint range can be specific to a geological feature and/or a mobile machine. The throttle position setpoint range can be determined such that it can indicate that mobile machine 100 is likely within a threshold area of a geological feature. For example, based on the route characteristics (e.g., grade) approaching a geological feature and the characteristics of mobile machine 100 (e.g., engine, load, etc.), the throttle position setpoint range of mobile machine 100 at about the point mobile machine 100 enters the threshold area can be determined Therefore, if throttle position signal 272 is not equal to the throttle position setpoint range, then mobile machine is likely not with the threshold area and controller 270 can return to step 300 and the decision logic can be repeated.
If throttle position signal 272 is within the throttle position setpoint range, then controller 270 can proceed to step 310 where it can be determined whether pressure signal 261 is less than a barometric pressure setpoint. The barometric pressure setpoint can be specific to a geological feature and/or a mobile machine. For example, the barometric pressure setpoint can be set to correspond with the barometric pressure at a corresponding altitude of each particular geological feature. The barometric pressure setpoint can be determined such that it can indicate that mobile machine 100 is likely within a threshold area of a geological feature. It is also contemplated that the barometric pressure setpoint could be a range rather than a setpoint.
If pressure signal 261 is not less than the barometric pressure setpoint, then controller 270 can return to step 300 and the decision logic can be repeated. If pressure signal 261 is less than the barometric pressure setpoint, then controller 270 can proceed to step 312. At step 312, steps 306, 308, and 310 may become latched, such that if any of the conditions are no longer met tunnel mode may remain operational.
According to the embodiment of
According to the embodiment of
According to the embodiment of
For both embodiments, the order of steps 306, 308, and 310 can be rearranged, such that any of the three steps can be first, second or third. Controller 270 may also be configured such that one or more of steps 306, 308, and 310 may be eliminated or bypassed. For example, controller 270 can proceed from step 302 directly to step 310 and, when the condition is met, controller can proceed to step 312.
In yet another embodiment, controller 270 may be configured to eliminate step 302 and step 304, and instead proceed directly from step 300 to step 305 for the
Controller 270 may also be configured to have a delay between each step. For example, a delay of about 10 seconds or less may be used between steps. This delay may provide adequate time for sending and receiving of signals, as well as initiating, stopping, and ramping of mechanical components (e.g., fan 230, pump 290, etc.). Track speed setpoint for step 306, throttle position setpoint range, barometric pressure setpoint, throttle setpoint, track speed setpoint for step 320, and the other setpoints may be set manually by the operator of mobile machine 100, hard coded, or an automatically read in from a data table, database, or look up tables.
Controller 270 may further be configured to receive an ambient air temperature signal indicative of an ambient air temperature in proximity to the mobile machine. Controller 270 may incorporate the ambient air temperature into the determination of the distance to the outer limit of the threshold area along the route of the mobile machine and/or incorporate the ambient air temperature signal into the determination of when to selectively activate the fan and cause the thermostat to move to maximum cooling position. For example, when the ambient air temperature is higher, the efficiency of heat exchanger 220 will be reduced and, therefore, additional cooling time will be needed before entering a geological feature. In contrast, when the ambient air temperature is cooler, the efficiency of heat exchanger 220 will increase and less cooling time will be needed before entering a geological feature.
The disclosed cooling control system 160 may provide an efficient mechanism for cooling of a mobile machine 100 in anticipation of and during temporary environmental extremes caused by a geological feature. For example, the disclosed cooling control system 160 may provide more effective cooling by performing one or more of the following operations, turning on fan 230, turning on blower 151, and turning on heat exchanger sprayer 221, moving thermostat 240, or moving pump 290 to maximum speed, enabling preemptive cooling before arriving at the geological feature. Additionally, cooling control system 160 may initiate tunnel mode based on a comparison of a location signal to a threshold area or when the location signal is unavailable based on receipt of a transponder signal or based on a comparison of a barometric pressure signal, therefore, enabling more reliable operation.
In other embodiments, it is contemplated that the cooling operations activated by controller 270 (e.g., turning on fan 230, turning on blower 151, and turning on heat exchanger sprayer 221, moving thermostat 240, or moving pump 290 to maximum speed) may vary from those embodiments described in reference to
It will be apparent to those skilled in the art that various modifications and variations can be made to the cooling control system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed cooling control system. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
