Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P7/00—Controlling of coolant flow
  • F01P7/14—Controlling of coolant flow the coolant being liquid
  • F01P7/16—Controlling of coolant flow the coolant being liquid by thermostatic control
  • F01P7/165—Controlling of coolant flow the coolant being liquid by thermostatic control characterised by systems with two or more loops
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P5/00—Pumping cooling-air or liquid coolants
  • F01P5/10—Pumping liquid coolant; Arrangements of coolant pumps
  • F01P2005/105—Using two or more pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2025/00—Measuring
  • F01P2025/60—Operating parameters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
  • F01P2060/00—Cooling circuits using auxiliaries
  • F01P2060/08—Cabin heater

Definitions

• the invention relates to the management of the cooling of an engine system equipped with a device for partial recirculation of the exhaust gases, in particular of a diesel engine system.
• the invention can thus find an application in the field of the automobile.
• An engine system is generally cooled by a cooling circuit.
• an internal combustion engine can transform the initial energy provided by the fuel in motion of the crankshaft. Part of the energy is transformed into distributed thermal energy in the exhaust gas and losses to the walls of the combustion chamber. Combustion can lead to chamber temperatures of the order of 800 ° C, whereas the cylinder heads of the combustion chambers, when made of aluminum alloy, are generally designed to withstand temperatures of 250 ° C maximum only. To limit the temperatures to acceptable values for a good thermomechanical behavior of the motor, it is necessary to evacuate enough calories towards the environment.
• the cooling circuit thus prevents overheating of the engine.
• this circuit can provide a relatively fast optimal thermal level of one or more other components of the powertrain, to contribute for example to the heating benefits of the passenger compartment.
• An EGR device Exhaust Gas Recirculation
• EGR Exhaust Gas Recycling
• NOx nitrogen oxide
• EGR cooler also called EGR exchanger
• EGR exchanger designed to cool the exhaust gases to be reintroduced to the engine intake, in a cooling circuit of the engine itself.
• a so-called hot-loop cooling circuit may comprise an EGR exchanger and an engine cooler, designed to cool an engine, on the same heat transfer fluid circulation loop.
• the temperature of the EGR device is thus close to the engine temperature.
• a thermostat device makes it possible to maintain the temperature of the heat transfer fluid at the output of the engine at a predetermined value, for example 90 ° C.
• a so-called mixed loop cooling circuit may comprise a motor and a radiator in fluid communication so as to form a heat transfer fluid circulation loop, and an EGR exchanger arranged in fluid communication with the radiator so as to form an additional loop circulation of the coolant.
• a thermostat can close a valve on the loop serving the engine, so that when the temperature is below a threshold, for example 90 °, the engine is not cooled by the heat transfer fluid.
• a pump placed between the EGR exchanger and the radiator makes it possible to guarantee a circulation of the coolant in the additional loop only, so as to cool the EGR exchanger.
• a method for managing the cooling of an engine system equipped with a partial exhaust gas recirculation device, by means of a cooling circuit comprising:
• radiator device adapted to lower the temperature of a heat transfer fluid
• a heater device located in the passenger compartment, a motor in fluid communication with the heater device so as to form a first coolant circulation loop,
• a first fluid circulation means arranged to circulate heat transfer fluid from the radiator into the engine, for example a first pump, so as to form a second coolant circulation loop,
• a cooler (or exchanger) of the partial exhaust gas recirculation device for cooling said partial exhaust gas recirculation device, and in fluid communication with the radiator, so as to form a third heat transfer fluid circulation loop ,
• a second fluid circulation means for circulating heat transfer fluid from the radiator into the cooler of the partial exhaust gas recirculation device, for example a second pump, a decoupling device arranged for in a first mode, closing the second loop so as to allow the circulation of heat transfer fluid only in the first loop and the third loop, and in a second mode, open the second loop so as to have a circulation of heat transfer fluid in the three loops at the same time.
• the method comprises:
• the partial exhaust gas recirculation device may be an EGR device.
• the cooler of the partial exhaust gas recirculation device is then called EGR cooler.
• This control of the third loop of a mixed loop circuit can thus be performed independently of the (de) coupling between the loops.
• the coupling device may comprise a thermostat arranged to open and close the second loop as a function of a measured or estimated temperature value, for example as a function of the temperature of the exhaust gases leaving the the combustion chamber.
• the second loop remains closed, so that the coolant circulates only in the first and the third loop.
• a threshold for example 90 ° C. or other
• the at least one received value, from which the control signal of the third loop is developed may comprise a temperature value, for example a measured temperature value of the engine exhaust gases. or heat transfer fluid at the output of the engine.
• a threshold for example 85 °, 105 ° C or other.
• the partial exhaust gas recirculation device in the start-up phase, can be cooled less than if the second pump was operating at the minimum of its capacity.
• the radiator is designed and sized to cool the engine.
• the radiator can thus provide a relatively high cooling power. By limiting the cooling of the partial recirculation device of the exhaust gas, it is possible to prevent the temperature of the gases in this device from being too low.
• the temperature of the EGR device can be maintained at sufficiently high values to prevent clogging, while being sufficiently low to guarantee a relatively low emission of nitrogen oxides.
• the temperature value is compared with a threshold, and the control signal is developed according to the result of this comparison.
• the control signal is developed in such a way as to optimize the operation of the device for partial recirculation of the exhaust gases.
• control signal can be designed so as to avoid the boiling of the cooling liquid. Indeed if the heat transfer fluid does not flow quickly enough, it may evaporate.
• control signal is developed so as to limit an increase in the temperature of the motor.
• control signal can be designed so as to limit the circulation of the heat transfer fluid in the EGR exchanger in the event of detection of risk of engine overheating.
• engine overheating is meant here that the temperature of the coolant at the motor output exceeds a threshold value, for example a threshold value at which it is slaved, for example 90 ° C, or a trigger threshold value, for example.
• a threshold value for example a threshold value at which it is slaved, for example 90 ° C, or a trigger threshold value, for example.
• a threshold value for example a threshold value at which it is slaved, for example 90 ° C
• a trigger threshold value for example.
• Example 1 10 ° C, or other.
• the cooling circuit may be insufficient to maintain the temperature around the desired threshold, for example 90 °.
• the circulation of heat transfer fluid in the third loop it is possible to limit the quantity of coolant withdrawn by this third loop, and thus to allow a greater circulation of coolant in the second loop (radiator), which can thus participate in the engine cooling.
• a risk of overheating can be detected when the temperature of the engine or the temperature of the coolant in the first, second and / or third loop reaches a temperature threshold, or even according to the point of operation of the engine.
• the operating point of the engine can be determined from, for example, engine load and engine speed.
• the invention is not limited by the way in which a risk of motor overheating is detected.
• the at least one received value and from which the control signal of the third loop is developed can be a temperature value, a boolean parameter value indicative of the state of the EGR. , a parameter value indicative of the engine speed, for example a number of revolutions per minute, a parameter value indicative of the position of the accelerator pedal, and / or other.
• control signal can be sent to the second pump to drive this second pump.
• the second pump may be an electric pump.
• control signal can be used to drive a supply voltage of the second pump.
• the opening duty cycle (OCR) of the second pump goes from 100% to 50%
• the flow rate in the radiator can be halved.
• the invention is in no way limited by a control of the second pump.
• a two or three-way valve could be provided between the engine, the radiator and the EGR exchanger.
• the heat transfer fluid from the engine is mainly redirected to the radiator rather than to the EGR exchanger, thus allowing the engine to cool more than when more of the fluid is withdrawn from the third loop.
• This two or three-way valve can be controlled by a management device implementing the method described above.
• the two or three way valve may be a variable flow valve.
• the section of this valve can thus be controlled so as to reduce the flow rate in the third loop, for example in the start-up phase.
• This program can be stored on a hard disk or other type of media, downloaded or otherwise.
• an engine cooling management device equipped with a partial exhaust gas recirculation device for a cooling circuit comprising:
• radiator device adapted to lower the temperature of a heat transfer fluid
• a heater device located in the passenger compartment, a motor, in fluid communication with the heater device, so as to form a first heat transfer fluid circulation loop,
• a first fluid circulation means arranged to circulate heat transfer fluid from the radiator into the engine, for example a first pump, so as to form a second coolant circulation loop,
• a cooler (or exchanger) of the partial exhaust gas recirculation device in fluid communication with the radiator, so as to form a third circulation loop of the coolant.
• a second fluid circulation means for circulating heat transfer fluid from the radiator into the cooler of the partial exhaust gas recirculation device for example a second pump,
• a decoupling device arranged for in a first mode, closing the second loop so as to allow the circulation of heat transfer fluid only in the first loop and the third loop, and in a second mode, open the second loop so as to have a circulation coolant in the second and third loop at the same time.
• the management device comprises:
• receiving means for receiving at least one value of a parameter relating to the engine system, for example a value of temperature, engine speed, activation state of an EGR device, or other means of processing to develop a control signal of the third loop according to this at minus a received value, so as to reduce the cooling of the partial recirculation device of the exhaust gas, and
• transmission means for transmitting the developed control signal to the third loop.
• the cooling circuit may be a mixed loop circuit.
• the cooling management device may comprise or be integrated in one or more digital processors of the signal processing, for example a microprocessor, a microcontroller and / or other.
• the reception means may comprise, for example, an input pin, an input port and the like.
• the processing means may comprise a processor core or CPU (of the "Central Processing Unit"), a processor or other.
• the transmission means may for example comprise an output pin, an output port or the like.
• an engine system comprising a partial exhaust gas recirculation device, the management device described above and the cooling circuit.
• the engine of this vehicle can be for example a diesel engine, or not.
• open a loop is meant that provides a fluid communication so that the fluid can travel the loop in the same direction, for example an opening a valve arranged on the loop.
• closing a loop is meant that one part of the loop is isolated so as to prevent the circulation of fluid in the loop, for example by closing a valve disposed on the loop.
• Figure 1 shows schematically an example of a cooling system according to one embodiment of the invention.
• FIG. 2 is a graph showing temperature values of the heat transfer fluid at the outlet of the engine and of the heat transfer fluid in FIG. output of the EGR exchanger, with or without control of the second pump, as a function of time.
• FIG. 3 is a logic diagram of an exemplary method according to one embodiment of the invention.
• a cooling circuit 1 comprises a heater 14, located in the passenger compartment of a motor vehicle not shown as a whole, and a motor 10, connected by conduits to form a first loop 21 circulation of heat transfer fluid.
• the circuit 1 further comprises a radiator January 1 disposed on a second coolant circulation loop 22.
• a first pump 12 can circulate coolant on the second loop so as to reduce the temperature of the engine.
• a thermostat 13 placed at the output of the motor 10 makes it possible to open and close this second loop 22 according to the temperature measured at the output of the motor 10.
• the heater 14 may be arranged on the first loop 21, so as to benefit from the circulation of the heat transfer fluid.
• a jar 15 may constitute a reserve of coolant.
• An EGR exchanger 16 may be placed on a third loop 23.
• the conduits of this third loop 23 form a branch in parallel with respect to the second loop 22.
• a second pump 17 may allow the flow of fluid between the EGR exchanger 16 and the radiator of the engine 1 1.
• the curve 101 corresponds to temperature values of the coolant at the outlet of the engine 10 in the cooling system 1 of FIG. 1.
• the curve 161 corresponds to temperature values at the outlet of the exchanger EGR 16 of the circuit of FIG. 1.
• the curve 200 corresponds to temperature values of the coolant at the outlet of the EGR exchanger 16, when the pump 17 is unmanned and maintained at 100% of its capacity.
• the radiator 1 1 thus serves only to cool the EGR exchanger 16.
• the heat transfer fluid is relatively cold and the EGR exchanger 16 can be maintained at relatively low temperatures, for example around 45 ° C.
• a management device for example a processor 18 embedded in the motor vehicle and further comprising the engine system, makes it possible to adapt the flow rate of the second electric pump 17, so as to optimize the operation of the various consumers and to limit the emission of pollutant nitrogen oxides.
• This processor 18 receives signals from different non-represented sensors, for example a heat transfer fluid temperature sensor at the output of the engine, and generates a control signal from the second pump 17, so that it modulates the flow rate of the coolant.
• sensors for example a heat transfer fluid temperature sensor at the output of the engine, and generates a control signal from the second pump 17, so that it modulates the flow rate of the coolant.
• the curve 161 may exhibit oscillations slightly greater than 50 ° C. during this starting phase. Such temperature values are particularly advantageous in that they make it possible to reconcile low emission of nitrogen oxides and the risk of limited clogging.
• the thermostat 13 opens the second loop 22, that is to say that the pump 12 brings heat transfer fluid into the engine 10. The temperature of the coolant is then slaved around 90 °. Buckles
• the temperature of the EGR exchanger rapidly reaches 90 ° C.
• Such a value which corresponds to relatively high levels of pollution and in the starting phase, remains acceptable here because the EGR is generally inactive when the engine is sufficiently stressed.
• the coolant for example a glycolated liquid
• the coolant circulates in the third loop in the clockwise direction in the diagram of FIG.
• heat transfer fluid arrives in the third loop 23 by what was then the output of the radiator January 1, according to the arrow referenced 25 in Figure 1. Said otherwise, the heat transfer fluid, maintained at a temperature close to 55 ° C in the third loop, is mixed with heat transfer fluid whose temperature is close to 90 °, since the engine 10, and quickly, the fluid temperature in the EGR exchanger becomes close to that of the fluid in the engine 10.
• the heat transfer fluid circulates from left to right in FIG. 1 in the radiator 1 1.
• the heat transfer fluid circulates from left to right in the radiator 1 1 of FIG.
• the radiator 1 1 is designed to allow the circulation of heat transfer fluid in both directions.
• a management method may be implemented by the processor 18 of FIG. 1.
• a coolant temperature value is received at the output of the engine TM, a value of a state_EGR parameter, indicative of the state of an EGR actuator, a value of a load parameter pedal_pos engine and a speed_mot engine speed parameter value.
• the state_EGR parameter can correspond to the position of the electrical actuator related to the management of the EGR.
• the engine load parameter may for example be an effective average pressure (PME) value on the accelerator pedal.
• the temperature value of the coolant TM is compared with a threshold value, for example 105 ° C or 110 ° C.
• step 203 a value of a control signal S is developed as a function of the parameter values pedal_pos and rate_mot. More precisely, a first two-dimensional mapping, called engine cooling mapping, can make it possible to read a control signal value as a function of the values of these two parameters. This first mapping is designed to, depending on the point of operation of the engine, control the flow in the third loop so as to cool relatively little EGR and use the resources of the radiator to further cool the engine.
• test 202 If the test 202 is negative, that is to say if the temperature is below the threshold value, then it is considered that the vehicle is in a starting situation or normal operation, with a risk of limited overheating.
• the control value of the second electric pump is always elaborated according to the parameter values pedal_pos and regime_mot, but with the aid of a second two-dimensional cartography, different from the first mapping, during a step 204.
• This second mapping is designed to control the flow in order to optimize the operation of the EGR, in particular so as to avoid clogging by amalgam.
• a loop may be implemented with an output test 206, for example a test to check that the motor is always on, and a step of introducing a latency time 207, between the execution of two loops.
• the invention is in no way limited by the way in which the electric pump is controlled. For example one could predict to control the pump only depending on the temperature.
• the invention is not limited to the use of cartography to develop the control signal, or even to specific maps.
• the engine cooling map used during step 203 may for example lead to a reduction of 30, 40 or 50% of the control RCO of the electric pump 17 when the engine is relatively under-loaded, and at a reduction of 90%. of this command when the values of the variables pedal_pos and regime_mot correspond to an over-solicitation of the motor. In this case, in order to prevent the motor from overheating, it is indeed possible to reduce the flow rate of the third loop 23 to 10% of its maximum value, in order to send more coolant cooled by the radiator 1 1 to the motor 10.
• the reliability mapping implemented in step 204 may also be designed to lower the flow rate in the third loop 23, for example to 40% of the maximum flow rate of the second pump, when the variables pedal_pos and regime_mot may correspond to a Beginning phase.
• a temperature sensor positioned at the inlet of the EGR cooler. This sensor can provide measurement values that can better discriminate startup situations, and thus provide a management more suitable for these startup situations in which the third loop is isolated from the second loop.
• the processor 18 can receive the values read by this sensor and be arranged to, when these values exceed a threshold, increase the flow rate in the third loop 23. It is indeed necessary to avoid the boiling of the coolant in this third loop 23.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust-Gas Circulating Devices (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=47878173

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (12)

• 2012
  • 2012-10-31 FR FR1260398A patent/FR2997448B1/fr not_active Expired - Fee Related
• 2013
  • 2013-10-24 WO PCT/EP2013/072221 patent/WO2014067836A1/fr active Application Filing
  • 2013-10-24 EP EP13783038.6A patent/EP2914827B1/de active Active
  • 2013-10-24 CN CN201380056061.3A patent/CN104769248B/zh active Active

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events