GB2517491A

GB2517491A - A Method and System of Heating a Vehicle Cabin

Info

Publication number: GB2517491A
Application number: GB1315100.6A
Authority: GB
Inventors: Andrew Pugh; Paul Simpson
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2013-08-23
Filing date: 2013-08-23
Publication date: 2015-02-25
Anticipated expiration: 2033-08-23
Also published as: CN104417317B; GB201315100D0; RU2014134129A; RU2666490C2; DE102014216262A1; GB2517491B; CN104417317A

Abstract

A vehicle comprises an internal combustion engine, preferably a diesel engine 10, a throttle 18 that varies a mass flow rate of air into the engine and a cabin heating assembly (not depicted) that transfers heat from the engine to a passenger cabin. One or more controllers (not depicted) determine whether additional cabin heating is required and adjust the position of the throttle to reduce the mass flow rate of air into the engine so as to increase engine temperature and thereby increase heat transferred to the passenger cabin. Ideally, the mass flow rate of intake air is measured by an air mass flow sensor 12a and compared with a desired value. The position of the throttle can be adjusted to meet the desired value, with the desired value being reduced when cabin heating is required. The vehicle may include an exhaust gas recirculation (EGR) system comprising an EGR loop 22, EGR valve 24, cooler 26 and a bypass valve 30. Preferably the throttle position is not adjusted when cabin heating is no longer required or when EGR is underway. The vehicle may also comprise an intercooler 16, turbocharger 14, diesel oxidation catalyst 20a and a diesel particulate filter 20b.

Description

A METHOD AND SYS'I'EM OF HEATING A VEhICLE CABIN The present disclosure relates a method and system oCheating a vehicle cabin and particularly but not exclusively relates to a method and system of heating a vehicle S cabin comprising adjusting the position of a throttle to reduce the mass flow of ambient air into an internal combustion engine.

Background

Combustion efficiency improvement and engine friction reduction in Diesel engines to achieve low emission and improved friel economy has led to a reduction in the quantity of heat transferred to the engine coolant. One undesirable effect of this is that the quantity of heat available to warm the vehicle cabin at low ambient temperatures has also reduced. Auxiliary electrical heaters are a partial so]ution, but in the latest generation of vehicles these have reached thcir maximum practical limits.

Currently, the main auxiliary heating systems used in passenger cars are: the addition of an electrical heating element in the heater unit (typically a resistive electrical heating element, which consumes 2kW of electrical power necessitating a large alternator), fuel fired heaters (uses heated element to burn fuel in heat exchanger in coolant circuit) or block heater (which requires the vehicle to be plugged into an external power supply).

In addition, Citroen are known to use post-injection fficlling strategics and an exhaust heat recovery system to improve their heater performance (see for example EP2055515). However, this requires extra hardware and has a cost in the form of extra fuel usage. Furthermore, the post-injection fuelling strategies also lead to increased fuel loss into the oil and at cold ambient temperatures there is no oil dilution recovery by evaporation, thereby significantly shortening the oil change interval.

The present disclosure seeks to address these issues.

Statements of Invention

According to a first aspect of the present disclosure there is provided a method of heating a. vehicle cabin of a vehicle, the vehicle comprising: an internal combustion engine; a throttle configured to vary a mass flow rate of air into the internal combustion engine; and a cabin heating assembly configured to transfer heat from the internal combustion engine to the vehicle cabin, wherein the method comprises: determining whether additional cabin heating is required; and adjusting the position of the throttle to reduce the mass flow rate of air into the internal combustion engine so as to increase a temperature associated with the intemal combustion engine and thereby increase the heat transferred to the cabin by the cabin heating assembly.

Determining whcthcr additional cabin heating may be required may comprise measuring the ambient air temperature and/or the cabin temperature. It may then he determined based on. the measured ambient air temperature and/or the cabin temperature 1 5 whether additional cabin heating is required.

The vehicle may thrthcr comprise a coolant circuit configured to cool the internal combustion engine. The coolant circuit may provide heat to the vehicle cabin. The method may further comprise increasing the temperature associated with the internal combustion engine; and increasing the transfer of heat. to the coolant circuit and thus to the vehicle cabin. The temperature of coolant in the coolant circuit may also he measured. The measured coolant temperature may be used to determine if additional cabin heating is required.

The method may further comprise determining a desired air mass flow rate into the internal combustion engine. The desired air mass flow rate may be reduced when it is determined that additional cabin heating may be required.

The method may further comprise determining a desired air mass flow rate into the internal combustion engine. The air mass flow rate into the internal combustion engine may he measured. The position of the throttle may be adjusted to obtain the desired air mass flow rate, e.g. depending on the difference between the measured mass flow rate and the desired mass flow rate.

The vehicle may further comprise an exhaust gas recireulat.ion loop configured to selectively recirculate exhaust gases from the internal combustion engine to an inlet of the internal combustion engine.

The method may further comprise preventing the flow of exhaust gas through the exhaust gas recirculation loop, e.g. whilst adjusting the position of the throttle to increase heat transferred to the cabin. The internal combustion engine may have a plurality of operational modes and the method may comprise operating in one of the operational modes. For example, the above-mentioned method maybe carried out in an operational mode in which the exhaust gas recirculation flow rate is set to zero.

Alternatively, the method may further comprise permitting the flow of exhaust gas through the exhaust gas rccirculation loop, e.g. whilst adjusting the position of the 1 5 throttle to increase heat transferred to the cabin.

If it is determined that exhaust gas recirculation may be desirable, the method may further comprise ending the adjustment of the throttle position to increase heat transferred to the cabin.

The method may further comprise determining that additional cabin heating is no longer required; and ending the adjustment of the throttle position. Determining that additional cabin heating is no longer required may comprise measuring thc ambient air temperature and/or the cabin temperature. The additional cabin heating may be stopped when the ambient air temperature and/or the cabin temperature reach a respective threshold value.

According to a second aspect olthe present disclosure there is provided a system for heating a vehicle cabin of a vehicle, the vehicle comprising: an internal combustion engine; a throttle configured to vary a mass flow rate of air into the internal combustion engine; and a cabin heating assembly configured to transfer heat from the internal combustion engine to the vehicle cabin, wherein the system comprises one or more controllers, e.g. modules, configured to: determine whether additional cabin heating is required; and adjust the position of the throttle to reduce the mass flow rate of air into the interna] combustion engine so as to increase a temperature associated with the internal combustion engine and thereby increase the heat transferred to the cabin by the cabin heating assembly.

The one or more controllers may be further configured to carry out any of the above mentioned methods. An engine control uiñt may comprise, at least in part, the above-mentioned controllers.

The internal combustion engine may comprise a diesel engine.

The invention also provides software such as a computer program or a computcr program product for carrying out any of the methods described herein, and a computer readable medium having stored thereon a program for carrying out any of the methods described herein. A computer program embodying the invention may be stored on a computer-readable medium, or it could, for example, be in the form of a signal such as a downloadable data signal provided from an Internet website, or it could be in any other form.

A vehicle or engine may comprise the above-mentioned system for heating a vehicle cabin of a vehicle.

Brief Description of the Drawings

For a bcttcr understanding of the present disclosure, and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 shows a schematic view of an air path through an internal combustion engine; Figure 2 shows a method of heating a vehicle cabin of a vehicle according to an

example of the present disclosure; and

Figure 3 shows a system of heating a vehicle cabin of a vehicle according to an example

of the present disclosure.

S Detailed Descdption With reference to Figure 1, a typical air path for an internal combustion engine 10 of a vehicle is described. One or more sensors 12 may be provided in the air flow path. For example. an air mass flow rate sensor 12a andlor an air temperature sensor 12b maybe provided in the air flow path. The air may pass through a compressor I 4a of a turbocharger 14. The turbocharger 14 may improve the engine power output and reduce emissions. Typically, the turbocharger 14 is arranged with an exhaust gas driven turbine 1 4b driving the compressor 14a mounted on the same shall. An optional intercooler 16 may be provided downstream of the turbocharger compressor 14a, e.g. to further increase the density of air entering the internal combustion engine 10. The air may enter the internal combustion engine TO via a throttle 18 configured to vary the mass flow of air into the internal combustion engine. In a particular example of the present disclosure, the internal combustion engine 1 0 comprises a diesel engine.

The exhaust gases leaving the internal combustion engine 1 0 may pass through the turbine 14b of the turbocharger. One or more exhaust treatment modules 20 may be provided, e.g. to reduce emissions from the engine exhaust. The exhaust treatment modules 20 may comprise one or more of an oxidation catalyst 20a. e.g. a diesel oxidation catalyst, and a particulate filter 20b, e.g. a diesel particulate filter.

An exhaust gas recirculation loop 22 configured to selectively recirculate exhaust gases from the internal combustion engine 10 back into the internal combustion engine may also be provided. The exhaust gas recirculation ioop 22 may comprise a recirculation valve 24, which may control the amount of recirculation. In addition, an exhaust gas cooler 26 may be provided in the exhaust gas recirculation loop 22. A cooler bypass passage 28 with a bypass valve 30 may be provided in parallel with the exhaust gas cooler 26 so that the cooler 26 may be selectively bypassed.

Although not shown in Figure 1, a cabin heating assembly may also be provided. The cabin heating assembly may be configured to transfer heat from the internal combustion engine to the vehicle cabin, A coolant circuit (also not showt) configured to cool the internal combustion engine 10 may also be provided. The coolant circuit may provide heat to the vehicle cabin, e.g. via the cabin heating assembly.

\Vith reference to Figures 2 and 3, the present disclosure relates to a method 100 of andlor system 200 for heating a vehicle cabin of a vehicle. Passengers of the vehicle may reside in the vehicle cabin when the vehicle is in use. As depicted in Figure 2, the method 100 comprises a first step 110 of determining whether additional cabin beating is required. The method 100 further comprises a second step 1 20 of reducing the mass flow rate of ambient air into the internal combustion engine 10. [he reduction in the mass flow rate of air may be achieved by adjusting the position of the throttle 18 to reduce the mass flow rate of ambient air into the internal combustion engine 10. As a 1 5 result, a temperature associated with the internal combustion engine may increase and morc heat may he transferred to the cabin by the cabin heating assembly. If it is determined in the first step 110 that additional cabin heating may be required, the second step 1 20 may then be carried out to provide the additional heat required.

The first step 110 of determining whether additional cabin heating may be required may comprise measuring the ambient air temperature, e.g. via sensor 12b. The first step 110 may additionally or alternatively comprise measuring the cabin temperature, e.g. via a temperature sensor in the vehicle cabin. A heating control setting, which may be set by the passengers of the vehicle, may also determine whether cabin heating and/or additional cabin heating are required. It may then be determined based on the measured ambient air temperature, the cabin temperature and/or heating control setting whether additional cabin heating is required.

The method 1 00 may frirther comprise determining a desired air mass flow rate into the internal combustion engthe 10. The air mass flow rate into the internal combustion engine may be measured, e.g. by sensor 12a. The position of the throttle 18 may be adjusted to obtain the desired air mass flow rate, e.g. depending on the difference bctween the measured mass flow rate and the desired mass flow rate. In this way, the mass flow of air into the internal combustion engine may be controlled in a closed loop.

eg. with a closed ioop controller. An air mass flow rate which is compatible with the engine requirements, such as torque, drivability and turbocharger surge limits, may thus be achieved.

However, when it is determined that additional cabin heating may be required, the desired air mass flow rate may he reduced, e.g. by a predetermined amount. The desired air mass flow rate may be reduced by an absolute amount or by a fraction of the previous desired flow rate. The size of the reduction in the desired air mass flow rate may be a function of the ambient and/or cabin temperatures. However, the desired air mass flow rate may not be reduced below a minimum air mass flow rate. It will be appreciated that the reduction in the air mass flow rate may be achieved by adjusting, e.g. partially closing, the throttle 18.

1 5 By partially closing the intake throttle valve 18 (which is typically 100% open during normal operation of a Diesel engine) at cold ambient and coolant temperatures, ii is possible to reduce the flow of cold air into the internal combustion engine. As a result, the temperature of the internal combustion engine is increased and the transfer of heat to the coolant circuit and thus to the vehicle cabin arc also increased. in a particular example. this method has been shown to increase the rate of heat rejection to the engine coolant and leads to a 10°C to 20°C increase in engine coolant temperature during a typical 50-1 OOkph drive cycle at an ambient air temperature of-i 8°C. The resulting increase in engine coolant temperature is available to the cabin heating assembly for improved cabin warm up.

The method 100 may further comprise preventing the flow of exhaust gas through the exhaust gas recirculation loop 22, e.g. whilst adjusting the position of the throttle 18 to increase heat transferred to the cabin. However, if it is determined that exhaust gas recireulation may be desirable, the method 100 may further comprise ending the adjustment of the throttle position to increase heat transferred to the cabin. Exhaust gas recirculation may in any case increase the temperature of the internal combustion engine and thus the coolant and so the above-described method 100 may not be required.

Alternatively, the method tOO may further comprise permitting the flow of exhaust gas through the exhaust gas rccircuiation loop 22. e.g. whilst also adjusting the position of the throttle 18 to increase heat transferred to the cabin.

The internal combustion engine 10 may have a plurality of operational modes and the method may comprise operating in one of the operational modes. For example. the above-mentioned method may be carried out in an operational mode in which the exhaust gas recirculation flow rate is set to zero.

The method 100 may further comprise determining that additional cabin heating is no longer required; and ending the adjustment of the throttle position. Determining that additional cabin heating is no longer required may comprise measuring the ambient air temperature, and/or the cabin temperature andlor monitoring the heating control setting.

1 5 The additional cabin heating may be stopped hen the ambient air temperature and/or the cabin temperature reach a respective threshold value or when the heating control setting is turned off.

With reference to Figure 3, the system 200 for heating a vehicle cabin of a vehicle comprises one or more controllers with a first module 210 configured to determine whether additional cabin heating is required. The controllers comprise a second module 220 configured to adjust the position of the throttle to reduce the mass flow rate of ambient air into the internal combustion engine so as to increase a temperature associated with the internal combustion engine and thereby increase the heat transferred to the cabin by the cabin heating assembly. It will be appreciated that the one or more controllers may comprise further modules configured to carry out any of the above-mentioned methods. For example, the controllers may determine which of the operational modes the internal combustion engine operates in. It will also he appreciated that the controllers may comprise pre-existing controllers that have been re-programmed to carry out any of the above-mentioned methods.

The method and system described herein require no extra hardware and can thus be readily deployed with little additional cost. It could also be retrofitted to existing vehicles if required. The present disclosure provides additional cabin heating whilst avoiding the disadvantages of post-injection, namely the additional hardware, the extra the! usage and increased oil dilution.

Claims

Claims 1, A method of heating a vehicle cabin of a vehicle, the vehicle comprising: an internal combustion engine; a throttle configured to vary a mass flow rate of air into the internal combustion engine; and a cabin heating assembly configured to transfer heat from the internal combustion engine to the vehicle cabin, wherein the method comprises: determining whether additional cabin heating is required; and adjusting thc position of thc throttle to reduce the mass flow rate of air into the internal combustion engine so as to increase a temperature associated with the internal combustion engine and thereby increase the heat transferred to the cabin by the cabin heating assembly.
2. The method of claim 1, wherein dctcrmining whether additional cabin heating is 1 5 required comprises: measuring the ambient air temperature and/or the cabin temperature; and determining based on the measured temperature(s) whether additional cabin heating is required.
3. The method of any preceding claim, wherein the vehicle further compriscs a coolant circuit configured to cool the internal combustion engine and provide heat to the vehicle cabin, and wherein the method further comprises: increasing the temperature associated with the internal combustion engine; and increasing the transfer of heat to the coolant circuit and thus to the vehicle cabin.
4. The method of any preceding claim, wherein the method further comprises: determining a desired air mass flow rate into the internal combustion engine; and when it is determined that additional cabin heating is required reducing the desired air mass flow rate.
5, The method of any preceding claim, wherein the method further comprises: determining a desired air mass flow rate into the internal combustion engine; measuring the air mass flow rate into the internal combustion engine; and adjusting the position of the throttle to obtain the desired air mass flow rate.
6. The method of any preceding claim, wherein the vehicle further comprises an exhaust gas recirculation loop configured to selectively recirculate exhaust gases from the internal combustion engine to an inlet of the internal combustion engine.
7. The method of claim 6, wherein the method further comprises: preventing the flow of exhaust gas through the exhaust gas recirculation loop.
8. The method of claim 6, wherein the method further comprises: permitting the flow of exhaust gas through the exhaust gas recirculation loop,
9. The method of any of claims 6 to 8, wherein if it is determined that exhaust gas reeirculation is desirable, the method further comprises: ending the adjustment of the throttle position..
10. The method of any preceding claim, wherein the method further comprises: determining that additional cabin heating is no longer required; and ending the adjustment of the throttle position.
11. A system for heating a vehicle cabin of a vehicle, the vehicle comprising: an internal combustion engine; a throttle configured to vary a mass flow rate of air into the internal combustion engine; and a cabin heating assembly configured to transfer heat from the internal combustion engine to the vehicle cabin, wherein the system comprises one or more controllers configured to: determine whether additional cabin heating is required; and adjust the position of the throttle to reduce the mass flow rate of air into the internal combustion engine so as to increase a temperature associated with the internal combustion engine and thereby increase the heat transferred to the cabin by the cabin heating assembly.
1 2. The system of claim 11, wherein the one or more controllers are further configured to carry out the method of any of claims 2 to 10.
13. The method or system of any preceding claim, wherein the internal combustion engine comprises a diesel engine.
14. Software which when executed by a computing apparatus causes the computing apparatustoperformthemethodofanyofclaims ito 10.
15. A vehicle or engine comprising the system for heating a vehicle cabin of a vehicle of any of claims 11 to 13.
16. A method of heating a vehicle cabin of a vehicle substantially as described herein with reference to and as shown in Figure 2.
17. A system for heating a vehicle cabin of a vehicle substantially as described herein withrekencetoandasshowninFigure3.