SE538968C2

SE538968C2 - A heating arrangement for a compartment in a vehicle

Info

Publication number: SE538968C2
Application number: SE1451499A
Authority: SE
Inventors: Kardos Zoltan; Björkbacka Tommi
Original assignee: Scania Cv Ab
Priority date: 2014-12-09
Filing date: 2014-12-09
Publication date: 2017-03-07
Also published as: SE1451499A1

Abstract

11 Abstract The present invention relates to a heating arrangement for a compartment in a vehicle.The vehicle comprises a first cooling system cooling a combustion engine (2) and asecond cooling circuit cooling charged air in a charged air cooler (18). The heatingarrangement comprises a control unit (35) receiving information of the temperature ofthe coolant in the first cooling system and the temperature of the coolant in the secondcooling system. The control unit controls a first valve member (29) such that coolantfrom the cooling system having the highest temperature is directed to a heater (24) in the compartment (23). (Pig. 1)

Description

AND PRIOR ART The present invention relates to a heating arrangement for a compartment in a vehicle according to the preamble of claim l. lt is desired to obtain a fast heating of the driver's cab in a vehicle. Usually, the coolantin the cooling system cooling the combustion engine is used to heat the driver's cab.During a cold start of a vehicle, the combustion engine and the coolant in the coolingsystem have initially a temperature corresponding to the ambient temperature of the.Especially when the ambient temperature is very low, it takes a relatively long time forthe combustion engine and the coolant to be heated to a temperature where the coolant is able to heat the air in the driver's cab to a desired temperature.

The amount of air which can be supplied to a supercharged combustion enginedepends on the pressure and the temperature of the charged air. ln order to supply alarge amount of charged air to the combustion engine, it is necessary to cool thecharged air to a low temperature. The charged air may be cooled in a charged aircooler by coolant in a low-temperature cooling system. The coolant in the lowtemperature cooling system has a lower temperature than the coolant in the coolingsystem cooling the combustion engine. During favorable circumstances, the charged air can be cooled to a temperature close to the ambient temperature.

US 2009/0211542 show a system for controlling the therrnal energy of a motorvehicle. The system comprises a high temperature circuit and a low temperaturecircuit. The coolant in the high temperature circuit comprises a heating radiatorsupplying heat to a vehicle cabin. The coolant in the low temperature circuit is used to cool, for example, cool charged air in a charged air cooler.

SUMMARY OF THE INVENTION The object of the present invention is to provide a heating arrangement able to provide a fast heating of a compartment in a vehicle after a cold start.

The above mentioned object is achieved by the heating arrangement according to thecharacterised part of claim l. The vehicle comprises a first cooling system including acirculating coolant cooling a combustion engine. The operating temperature of thecoolant in the first cooling system is relatively high since a favorable operatingtemperature of a combustion engine may be Within the temperature range of 90-l00°C.The vehicle comprises a second cooling system including a circulating coolant coolingcharged air in a charged air cooler. The operating temperature of the coolant in thesecond cooling system is to be relatively low since it is favorable to cool the charge airto a low temperature before it enters the combustion engine. It is advantageous to usethe coolant in the first cooling to heat the compartment in the vehicle during mostoperating conditions. HoWever, the coolant in the second cooling system obtains afaster heating in the charged air cooler than the coolant in the first cooling system aftera cold start. As a consequence, the coolant in the second cooling system has a highertemperature than the coolant in the first cool system during a period of time after acold start.

The heating arrangement receives information about the temperature of the coolants inthe respective cooling systems and controls a first valve member such that it directs thecoolant having the highest temperature to the heater in the compartment. During aninitial period of time after a cold start, the coolant in the second cooling system is usedto heat the compartment Whereupon the coolant in the first cooling system is used toheat the compartment When it has been heated to a higher temperature than the coolantin the second cooling system. In this case, a faster heating of the compartment isobtained than if the compartment only Were heated by coolant from the first coolingsystem after a cold start. The compartment in the vehicle is preferably the driver's cab but it is of course possible to heat other compartments in a vehicle.

According to an embodiment of the invention, the heating arrangement comprises asecond valve member directing coolant back to the same cooling system that theycame from. In this case, the coolant from the first cooling system and the coolant from the second cooling system Will not be mixed With each other.

According to an embodiment of the invention, the second inlet line conducts coolantfrom a charged air cooler outlet line to the heater. Charge air obtains a hightemperature when it is compressed in a compressor. As a consequence, the charge airprovides a fast heating of the coolant in the charge air cooler even during a cold start.The coolant in the second cooling system has its highest temperature when it leaves thecharge air cooler. Thus, it is favorable to use coolant from a charged air cooler outletline to heat the compartment during a period of time after a cold start. The first inletline may conduct coolant from an engine outlet line of the first cooling system to theheater. The coolant in the first cooling system has usually its highest temperature in anoutlet line from the engine. lt is favorable to use this coolant to heat the compartment when the coolant in the first cooling system has reached its operating temperature.

According to an embodiment of the invention, the first cooling system comprises afirst radiator in which the coolant cooled by ambient air. The first radiator can beplaced in a front portion of a vehicle. A cooling air ﬂow can be directed through thefirst radiator by a radiator fan. The second cooling system may comprise a secondradiator in which the coolant is cooled by ambient air. Preferably, the second radiatoris arranged in an upstream position of the first radiator in view of the air ﬂow directionthrough the radiators. ln this case, it is possible to cool the coolant in the secondcooling system with air of ambient temperature which results in a cooling of the chargeair in the charge air cooler to a low temperature. The coolant in the first cooling systemis cooled by air of a higher temperature which already has passed through the first radiator.

According to an embodiment of the invention, the second cooling system comprises abypass line conducting the coolant past the second radiator and a third valve memberconfigured to direct the coolant ﬂow to the second radiator or to the bypass line. Thethird valve member may be a conventional thermostat directing the coolant ﬂow to thebypass line when the temperature of the coolant is lower than a regulating temperatureof the therrnostat and to the second radiator when the temperature of the coolant ishigher than the regulating temperature of the therrnostat. Alternatively, the control unitis configured to control the valve member such that it conducts the coolant to thebypass line when the coolant in the second cooling system is directed to the heater. lnthis case, it is possible to increase the temperature of the coolant in the second cooling system and provide an even faster heating of the compartment.

According to an embodiment of the invention, the second cooling system comprisesﬂow restricting means, wherein the control unit is configured to control the ﬂowrestricting means such that the coolant ﬂow in the second cooling system is reduced atcertain operating conditions when the coolant in the second cooling system is directedto the heater. A reduced coolant ﬂow to the charge air cooler results in a highertemperature of the coolant leaving the charge air cooler. In order to provide a fastrising of the temperature in the compartment, the coolant directed to the heater has tohave a markedly higher temperature than the air in the compartment. The ﬂowrestricting means may comprise a throttle valve able to reduce the ﬂow area in asuitable part of the second cooling system or a controllable pump able to provide an adjustable coolant ﬂow in the second cooling system.

BRIEF DESCRIPTION OF THE DRAWING In the following a preferred embodiment of the invention is described, as an example, with reference to the attached drawing, in which: Fig. l shows an embodiment of the heating arrangement.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THEINVENTION Fig. l shows a combustion engine 2 powering a schematically disclosed vehicle l.The combustion engine 2 may be a diesel engine. The vehicle l may be a heavyvehicle. The vehicle l comprises a first high temperature cooling system. The firstcooling system comprises an engine inlet line 3 provided with a pump 4 circulating afirst coolant in the first cooling system. The pump 4 circulates the coolant to thecombustion engine 2. When the coolant has circulated through the combustion engine2, it enters an engine outlet line 6 comprising a retarder cooler 5. The coolant isintended to cool oil in the retarder cooler 5 when a not shown retarder is activated. Athermostat 7 is arranged at an end of the engine outlet line 6. In case the coolant has alower temperature than the regulating temperature of the thermostat 7, the coolant isdirected back to the pump 4 via a first retum line 8. In case the coolant has a higher temperature than the regulating temperature of the therrnostat 7, the coolant is directed to a first radiator 9 arranged at a front portion of the vehicle 1. A radiator fan 10provides a cooling air ﬂow through the first radiator 8. When the coolant has circulatedthrough the first radiator 9, it is directed, via a second return line 11, back to the engine inlet line 3 and the pump 4.

The vehicle 1 comprises a second low temperature cooling system with a secondcirculating coolant. The second cooling system comprises a second radiator 12arranged in an upstream position of the first radiator 9 in view of the air ﬂow directiondefined by the radiator fan 11. Thus, the second coolant is cooled in the secondradiator 12 to a lower temperature than the first coolant in the first cooling system. Thecoolant in the second cooling system is circulated by means of a second pump 13. Thesecond cooling system comprises a first branched line 14 in which the coolant coolsrefrigerant in an AC cooler 15 and recirculating eXhaust gases in an EGR cooler 16.The second cooling system comprises a second branched line 17 in which the coolantcools charged air in a charged air cooler 18 and gearboX oil in an oil cooler 19. Thefirst branched line 14 and the second branched line 17 are connected to each other in adownstream position of the coolers 15, 16, 18, 19 such that the coolant is conducted ina common line 20 towards a third valve member 21. The common line 20 comprises athrottle valve 20a. The third valve member 21 directs the coolant to the second radiator 12 or back to the second pump 21 via a bypass line 22.

The vehicle comprises a heating arrangement configured to heat the air in acompartment of the vehicle in the form of the driver°s cab 23. The heating arrangementcomprises a heater 24, a fan 25 forcing air through the heater 23 and an electric engine26 driving the fan 25. The heating arrangement comprises a first inlet line 27 receivingcoolant from the first cooling system and a second inlet line 28 receiving coolant fromthe second cooling system. A first valve member 29 is configured to direct coolantfrom the first inlet line 27 or the second inlet line 28, via a heater inlet line 30, to theheater 24. A heater outlet line 31 comprises a second valve member 32 configured todirect the coolant back to the first cooling system via a first outlet line 33 or to thesecond cooling system via a second outlet line 34. The first outlet line 33 directs the coolant back to the first cooling system in a position substantially immediately upstream of the first pump 4. The second outlet line 34 directs the coolant back to the second cooling system in a position substantially upstream of the second pump l3.

The heating arrangement comprises a control unit 35 receiving information from a firstsensor 36 sensing the temperature of the coolant in the engine outlet line 6 of the firstcooling system and from a second sensor 37 sensing the temperature of the coolant in acharge air outlet line l7a of the second cooling system. The vehicle l comprises aturbo aggregate in the form of a turbine 38 and a compressor 39. The turbine 38 drivesthe compressor 39 by means of the eXhaust gases in an eXhaust line 40. Thecompressor 39 is arranged in an air inlet line 4l delivering charged air to thecompression engine 2. The charged air is cooled in the charge air cooler 18 by coolantin the second cooling system before it is directed into the combustion engine 2. AneXhaust recirculating line 42 recirculates a part of the eXhaust gases from the eXhaustline 40, via the air inlet line 4l, to the combustion engine 2. The recirculating eXhaustgases is cooled in a first step in a first EGR-cooler 43 by coolant in the first coolingsystem and in a second step in a second EGR-cooler l6 by coolant in the second cooling system.

During a cold start of the vehicle l, the combustion engine 2, the coolant in the firstcooling system and the coolant in the second cooling system. If the temperature of theambient air is low, it is a corresponding low temperature in the driver's cab 23. Thecombustion engine 2 represents a large mass and it takes ta relatively long time for thecombustion engine 2 to be heated to its operating temperature. As a consequence, thecoolant in the first cooling system obtains a slow heating after a cold start. On theother hand, the air in the air inlet line 4l obtains substantially immediately a hightemperature when it is compressed by the compressor 39. When the coolant in thesecond cooling system cool the hot charged air in the charged air cooler 18, it obtains afast heating. Thus, the coolant in the second cooling system obtains substantiallyalways a higher temperature than the coolant in the first cooling system during a first period of time after a cold start.

The control unit 35 receives substantially continuously information from the firsttemperature sensor 36 about the temperature of the coolant in engine outlet line 6 ofthe first cooling system and from the second temperature 37 sensor about thetemperature of the coolant in the charge air cooler outlet line l7a of the second coolingsystem. The control unit 35 deterrnines which of the coolant has the highesttemperature. When the control unit 35 receives information from the temperaturesensors 36, 37 indicating that the coolant in the second cooling system has the highesttemperature, the control unit 35 sets the first valve member 29 in a second position. Inthe second position, the second valve member 29 receives coolant, via the second inletline 28, from the charge air cooler outlet line l7a of the second cooling system. Thecontrol unit 29 directs the coolant, via the heater inlet line 30, to the heater 24. Thecontrol unit 35 sets the second valve member 32 in a second position. When thecoolant has passed through the heater 24 and heated the air in the driver's cab 23, it isdirected back, via the second outlet line 34, to the second cooling system. The coolant is received in a radiator outlet line l2a of the second cooling system.

The control unit 35 may also control the pump l3 in the second system or the throttlevalve 20a in order to decrease the coolant flow in the second cooling system when thecoolant in the second cooling system is directed to the heater 24. In this case, a lowercoolant ﬂow is directed to the charge air cooler 18. The coolant obtains a heating to ahigher temperature in the charge air cooler 18. As a consequence, coolant with a highertemperature is directed to the heater 24 where it heats the air in the driver's cab 23.The increased temperature difference between the coolant and the air in the driver's cab 23 results in a faster temperature raise in the driver's cab 23.

Furthermore, the control unit 35 may control the third valve member 2l such that itdirects the coolant in the second cooling system to the bypass line 22 and passed thesecond radiator l2 during a period of time after a cold start. In this case, thetemperature of the coolant in the second cooling system increases as well as thetemperature of the coolant directed to the heater 24, which results in a faster heating ofthe air in the drivers cab 23. Altematively, the third valve member 2l may be a conventional thermostat directing the coolant to the bypass line 22 when the coolant has a lower temperature than the regulating temperature of the thermostat and to thesecond radiator l2 When the coolant has a higher temperature than the regulatingtemperature of the thermostat. In view of the above mentioned measures, the heatingarrangement provides a significantly faster heating of a compartment 23 in a vehicleafter a cold start than a conventional heating arrangement and substantially Without reduction of the efficiency of the combustion engine 2.

A period of time after a cold start, the coolant in first cooling system obtains a highertemperature than the coolant in the second cooling system. The control unit 35 sets thefirst valve member 29 in a first position. In the first position, coolant from the engineoutlet line 6 enters the valve member 29 via the second inlet line 27. The control unit29 directs the coolant from the high temperature cooling system, via the heater inletline 30, to the heater 24. The control unit 35 sets the second valve member 32 in a firstposition. When the coolant has passed through the heater 24 and heated the air in thedriver's cab, it is directed back by the second valve member 32, via the first outlet line33, to the first cooling system. The coolant is received in the second return line ll of the first cooling system.

The invention is not restricted to the described embodiment but may be varied freely Within the scope of the claims.

Claims

1. A heating arrangement for a compartment in a vehicle, Wherein the vehicle (1)comprises a first cooling system cooling a combustion engine (2) and a second coolingsystem, Wherein the heating arrangement comprises a heater (24) arranged in thecompartment (23) of the vehicle (1), a first inlet line (27) conducting coolant from thefirst cooling system to the heater (24) and a first temperature sensor (3 6) sensing thetemperature of the coolant in the first cooling system, a second inlet line (28)conducting coolant from the second cooling system to the heater (24), a secondtemperature sensor (3 7) sensing the temperature of the coolant in the second coolingsystem, a first valve member (29) configured to direct coolant from one of the inletlines (27, 28) to the heater (24) and a control unit (35) configured to receiveinformation from the temperature sensors (36, 37) about the temperatures of thecoolants in the cooling systems and to control the first valve member (29) such thatcoolant from the cooling system having the highest temperature is directed to theheater (24), characterised in that the second cooling system cools charged air in acharged air cooler (18) and that the second cooling system comprises ﬂow restrictingmeans (13, 20a), Wherein the control unit (35) is configured to control the ﬂowrestricting means (13, 20a) such that the coolant ﬂow in the second cooling system isreduced at certain operating conditions When the coolant in the second cooling systemis directed to the heater (24).

2. Heating arrangement according to claim 1, characterised in that the heatingarrangement comprises a first outlet line (33) and a second outlet line (34) and asecond valve member (32) directing coolant back, via one of the outlet lines (33, 34), to their respective cooling system.

3. Heating arrangement according claim 1 or 2, characterised in that the first inlet line (27) conducts coolant from an engine outlet line (6) to the heater (24).

4. Heating arrangement according to any one of the preceding claims, characterised inthat the second inlet line (28) conducts coolant from a charged air cooler outlet line(17a) to the heater (24).

5. Heating arrangement according to any one of the preceding claims, characterised inthat the first cooling system comprises a first radiator (9) in Which the coolant is cooled by air.

6. Heating arrangement according to any one of the preceding claims, characterised inthat the second cooling system comprises a second radiator (12) in Which the coolant is cooled by air of ambient temperature .

7. Heating arrangement according to claim 5 and 6, characterised in that the secondradiator (12) is arranged in an upstream position of the first radiator in View of the airﬂow direction through the radiators (9, 12).

8. Heating arrangement according to claim 6 or 7, characterised in that the secondcooling system comprises a bypass line (22) conducting the coolant past the secondradiator (12) and a third Valve member (21) configured to direct the coolant flow to the second radiator or the bypass line (22).

9. Heating arrangement according to claim 8, characterised in that the control unit(35) is configured to control the third valve member (21) such that it conducts thecoolant to the bypass line (22) When the coolant in the second cooling system isdirected to the heater (24).