DE102005035121A1 - Heating and air conditioning device operating method for e.g. passenger car, involves temporarily throttling coolant flow-rate in heating path, so that minimum heating criterion characterizing minimum heat potential is fulfillable - Google Patents

Abstract

The method involves depriving heat from a coolant of a drive machine and delivering the heat to cabin air supplied by a heat exchanger (4), by a heating blower. A coolant flow-rate is temporarily throttled in a heating path (4a) by a throttle device toward reduced heating potential in such a manner that a minimum heating criterion, which characterizes the required minimum amount of heat potential, is fulfillable by the associated adjustment of an air-sided temperature controller. Independent claims are also included for the following: (1) a device for operating a heating and air conditioning device (2) a method and device for cooling an internal combustion engine.

Description

The This invention relates to a method and apparatus for Operation of an engine cooling and Heating system with improved utilization of engine waste heat for cabin heating purposes and to save fuel.

Especially it refers to an air-conditioning controlled heating and air conditioning unit in motor vehicles, with a heating heat exchanger, which the coolant the prime mover heat withdraws and to the means of a heating fan through the heating heat exchanger funded Cabin air, as well as various approaches to solving on the air and water side Regulated air conditioners Save fuel.

Partial aspects of the invention are already in the application DE 10 2004 058 869.4 of the applicant of the same name of 06.12.2004 and are further developed here in particularly effective embodiments.

It is known to reduce fuel consumption in modern cars by means of thermal management measures. In particular, a rapid heating of the coolant and the engine oil and thus also the engine components and the raising of the thermostatic opening temperature in the partial load are proven means to realize fuel consumption improvements. In this context shows the original application DE 10 2004 058 869.4 of the applicant of the same name of 06.12.2004 particularly effective methods to improve at low cost and sometimes even with cost savings compared to today's production vehicles, fuel consumption and / or cabin heating.

Especially it is known in air-side controlled heaters, i. for heaters, where the temperature of the air delivered to the cabin by means of the mixture one through the heater core funded Air flow adjusted with a non-heated bypass air mass flow is, the coolant flow in the heating branch in driving situations without heating by means of shut-off valves too prevention. A faster warming of the engine leads here to improve fuel economy.

In addition will with this measure the heat transfer that is undesirable when set to maximum cooling effect minimized to the cabin air. This helps to improve comfort and, where appropriate, for vehicles with air conditioning systems via reduction the drive power of the air conditioning compressor and the improvement of fuel consumption.

to cooling water side Shutdown of the heating branch are known applications Solenoid valves used or valves with vacuum cans as an actuator, the above a vacuum solenoid valve are controlled. The control takes place i.a. ultimately over a digital I / O port of the engine control or the air conditioner and allows the Settings "on" and "closed". Regulations of the Flow, e.g. above clocked opening and closing, as they are known from water heaters, do not apply, because the air-side temperature control the regulation of the cabin temperature takes over.

In With regard to fuel consumption, such systems have the disadvantage that even with low heating demand opening the water valve in the heating branch necessary is. This is in previously known embodiments of this Systems directly the loss the fuel consumption benefits due to the "deactivated" heat-active Mass in Heizzweig accompanied.

The Number of trips with the possibility of being completely up dispensing with a certain heat output is in practice relatively low. Rather, it is almost always in spring and autumn requires a certain amount of heating, to keep the discs free of fogging. Even in the summer can Often not waived a certain amount of heat especially in vehicles with air conditioning, where the heating heat exchanger for temperature control and for dehumidifying always a certain amount of heat is removed.

The Effectiveness of the additional Water valve with air-side temperature control in relation to the Fuel economy is therefore almost exclusively on the legal Exhaust gas test limited, without heating or air conditioning at temperatures of about 22-25 ° C is driven and on driving situations with maximum cooling demand ("Pull-down") in vehicles with air conditioning.

The costs for an additional Shut-off valve in the heating branch relative to the achievable fuel economy In the current fuel prices often just barely under the limit for an economic introduction, so far in many vehicles not of this possibility Fuel saving is made use of.

In contrast, there is the task of a heating and air conditioning unit, in particular a heater with air-side control of the cabin heating, so umzugestalten that results in fuel economy with and without Nutzwärmeantnahme the cabin heat exchanger and in particular Nutzwärmeentnahme the cabin heat exchanger with limited heating demand and thus an overabundance of potential heating power.

there In particular, the costs should be limited by the fact that components for Come in for both the improvement of the heating with high heating demand as well as for the improvement of fuel consumption can be used.

These Task is solved by the method according to claim 1.

The accompanying claims solve this task as well and link the associated inventive concept in particular with new embodiments for solving the task of the original application DE 10 2004 058 869.4 of the applicant of the same name dated 06.12.2004.

By the extension of the scope of application of the additional valve in the heating branch according to claim 1 on operating points with heat extraction the cost / benefit ratio improves so much that already economic introduction becomes possible at today's fuel prices.

In In connection with the adjoining claims, the scope of use widens of the inventive concept even in areas that go far beyond minimizing the heat-reactive Mass and heat losses go beyond the heating branch, up to the possibility of very cost-effective heat management functionalities or to improve the previously known thermal management measures elaborate additional components such as el. map thermostats, three-disc thermostats, stepless el. rotary valves as controlled by the engine control Radiator thermostat replacement or even el. Engine coolant pumps need.

By the demand throttling the cooling water flow in the heating branch will be the maximum transferable to the heat exchanger heat limited to a value below that at full coolant flow rate achievable value, however, is at least so great that the airside Temperature control by suitable mixing of cold bypass air and warmer Air from the heater core the desired air outlet temperature can adjust. By the fulfillment the minimum heating criterion ensures that there is sufficient margin, i.e. suitable enthalpy current pairings with cold and warm air flow, to rapid regulation and thus to meet the climate comfort requirements is available.

in the Compared to a conventional air-side controlled air conditioning flows thereby unchanged Operating point, i. unchanged Total mass air flow and unchanged Cabin injection temperature, in most operating conditions on the one hand more air through the heater core and correspondingly less air through the unheated bypass branch. on the other hand is the cooling water in the Heating branch substantially due to the lower coolant flow rate stronger cooled.

ever according to heating power requirement leaves on this way - at correct dosage of the coolant mass flow relative to the required heat output - a reduction of the effective thermally active Achieve mass in the heating branch by 50-75%. This is partly because Remember that the coolant in wide map areas of heat extraction and especially at low heat extraction the heating heat exchanger leaves almost at ambient temperature, i. wide areas of the heater core are heated much less than at high coolant mass flow. The return lines stay with rel. low heat extraction almost to ambient temperature.

With air conditioner operation, the return temperature drops in some cases even below the ambient temperature, ie it is almost at the air temperature at the evaporator outlet. Especially in conventional engine cooling systems with engine coolant bypass (s.p. 6b in 1 ), this extremely low temperature is quite desirable, as it even adjusts a certain heat pump effect, which ultimately benefits the engine heating. Without engine coolant bypass flow - appropriate applications will be described later - you will use in fuel consumption optimal operation, at least for trips without maximum heating demand, in general, not the whole cooling potential, inter alia, to avoid local overheating of the engine and depending on the engine and a heat transfer from Cylinder head to realize the cylinder block.

Even the heating supply line remains especially at low heat extraction at the heating heat exchanger due to the surface heat losses over the yardage averaged at a reduced temperature level and needed thus less engine waste heat for the Heating.

In other words, the reduction of the coolant flow rate reduces the effective heat-active mass in the entire heating branch. This is accompanied by lower heat outputs for the heating and By lowering the surface temperatures also savings in surface heat losses.

to Implementation of the method according to the invention it is particularly advantageous, high-performance heat exchanger, in particular countercurrent heat exchanger to use, even with low cooling water throughput yet another good heat transfer and ensure temperature equality. With abandonment of the Utilization of the full range of fuel saving potential but can also with many standard heating heat exchangers and even with simple cross-flow heat exchangers still significant Benefits are achieved.

Especially It is advantageous if as the minimum heating criterion a map is stored in the control of the climate control part or the engine control, that ensures the coolant flow rate in the heating branch with decreasing heat removal at the heating heat exchanger decreases and in particular, that the coolant outlet temperature of the heating heat exchanger despite low heat extraction preferably is lowered far in the direction of ambient temperature.

Thereby it is ensured that the greatest possible cooling of the refrigerant takes place and thus the engine heat primary the engine heating and thus the fuel economy benefits.

in the In connection with the control characteristics, it should be noted that at rel. high heat extraction and starting from high coolant flow rates especially for very efficient heating heat exchangers with the reduction of the coolant mass flow not always accompanied by a reduction in the heating effect in the cabin but z.T. an increase in the Kabinenheizwirkung. To exploit the full potential it is Here particularly advantageous that an additional map the area characterized in that a reduction of the coolant flow rate an improvement the cabin heat output and that in an oversupply at heating potential an additional Reduction of coolant flow rate below the throughput value of the maximum heating power.

at Multi-zone air conditioners, it is important to ensure that for the zone with the largest heat extraction enough Heating potential available is. With an uneven heat extraction inevitably goes here the loss cooling and thus fuel saving potential as long as each zone does not have its own cooling water-side flow restrictor receives. That's why it's limited on only one cooling water throttle particularly advantageous if the minimum heating criterion in multi-zone air conditioners a first map area for nearly uniform heat extraction for the has individual zones and additional Map areas for uneven heat extraction for the individual zones.

there It is particularly advantageous if the coolant flow in the heating branch with uneven heat extraction is higher as with even heat extraction.

Should even in multi-zone air conditioners the optimum cooling achieved be so it is particularly advantageous if zone-dependent minimum heating criteria by means of separate throttle devices for the cooling water throughputs the individual zones of the heating heat exchanger are complied with, so that in addition to the fulfillment the local heating power requirements as far as possible lowering the temperature at the heating return he follows.

Of the Effort for this is a little bit higher though especially at high efficiency and primarily for low coolant throughput designed heating heat exchangers with simple thermostats, e.g. in bimetal design, quite feasible with reasonable costs. In this constellation, it is sufficient in many cases Ensure that the coolant return is always below a defined limit of e.g. 20 ° C and at higher temperatures only a small leakage current for transporting the temperature information he follows. At high heat extraction, the return temperature falls below 25 ° C and the Valve opens.

There In winter often air outlet temperatures above 50 ° C and at the same time comparatively high air mass flows are needed, lies on the Hand that such a simple implementation in wintry driving a high performance heat exchanger which is capable of with low coolant flow rate and at the same time rel. high air flow rate.

1 shows an exemplary cooling and heating circuit for implementing the method according to the invention. It has a heating circuit 4a with heat exchanger 4 on which the heat from the cooling of the internal combustion engine 1 refers. An electric valve 2 sets a defined coolant mass flow as independent as possible of the speed of the internal combustion engine, which for example by means of the coolant temperature of the sensor 15 in the control unit 16 and with the aid of the heat exchanger map in dependence on the blower position, the ambient temperature and the current position of the air temperature control flap 5 in a theoretical air temperature of the air masses stream 20 is converted at the outlet from the heater. If this temperature deviates from the setpoint temperature, the air temperature control flap regulates 5 to.

Is the position of the air temperature control flap 5 very close to one of the two end stops, the coolant mass flow is achieved by opening or closing the valve 2 changed so that again a position with sufficient safety distance for a robust temperature control with the air temperature control flap 5 consists.

To increase the control quality, it is particularly advantageous if, in addition to the calculation of the temperature of the air mass flow 20 a sensor whose temperature measures. In many vehicles, such a sensor is present anyway, with sufficient response speed may possibly even on the arithmetic operations for low-dead time determination of the outlet temperature of the air mass flow 20 be waived.

From the heat exchanger 4 the coolant flows over the radiator thermostat 6 and the coolant pump 7 back to the internal combustion engine 1 , Next to the heating branch 4a the coolant flows when the radiator thermostat is closed 6 additionally through the bypass branch 6b , The coolant flow rate in the bypass branch 6b is considerably larger than in the heating branch, so that this ultimately homogenized the engine coolant temperature largely independent of the heating return temperature and the thermostat opening temperature of the radiator thermostat 6 Are defined.

As with air-side regulated air conditioning systems common practice, also takes in the inventive method with excess heat supply of the heating heat exchanger 4 the temperature control flap 5 the temperature control of the cabin inlet temperature 20 by the heated air mass flow 21 an unheated bypass air mass flow 22 is added. However, in contrast to known systems, the superimposition of the coolant throughput adaptation according to the invention causes a considerable coolant and component temperature reduction in the entire heating branch to be realized. As a result, on the one hand, less engine waste heat is needed for heating the heating branch and, on the other hand, due to the lower surface temperatures, the heat losses to the environment are also reduced.

The the resulting fuel savings are in particular characterized in that they are under almost all operating conditions the heating and possibly the air conditioning is present.

Essential However, there is a corresponding care in the design of the components and in the tuning of the control parameters. Before this Background shows

2 an exemplary map with curves for the flow dependence of the average temperature of the effective heat-active mass in the heating branch on the one hand and curves of the associated Nutzwärmeantnahme the heater core on the other. The effective heat-active material is made up in particular of the flow line with valve 2 , the heater core 4 and the return line together and is mass-averaged according to their local temperature distribution and component mass. The heat exchanger 4 is characterized in this record in that it is highly efficient even with small coolant flow rates, some simpler heat exchangers some map points are not quite reachable.

For an exemplary operating point with + 80 ° C flow temperature and + 7 ° C ambient temperature and + 7 ° C outlet temperature from the evaporator of the air conditioner, the heat removal at the heater core, of course, depends largely on the current fan setting or the air mass flow 21 , It is known from practice that, depending on the driver and the environmental conditions, almost the entire range of the air mass flows shown can occur.

From the families of curves pairs of curves are the same air mass flow to compare. If, for example, one compares the associated curves for 5 kg / min air mass flow, the curve for the mass-average temperature shows that the mass-averaged temperature is only slightly below the flow temperature of 80 ° C with unthrottled ie high coolant volume flow. In contrast to this, the method according to the invention will throttle the coolant mass flow at a heating power requirement of, for example, 5 kW from 12 l / min to about 1.4 l / min and thus achieve a lowering of the average temperature to below 50 ° C. If the heating power requirement is less than 1 kW, it is even possible to lower the mean temperature to below 40 ° C. by lowering the coolant throughput to very low values of 0.3 l / min and less. 2 makes it clear that the inventive reduction of the effective heat-active mass can still be realized even at very low air mass flows and thus inevitably very low heat removal at the heating heat exchanger. Even with these low heat withdrawals, a less efficient heating heat exchanger is already sufficient to exploit the advantages.

2 But also makes it clear how important careful coordination of the control strategy described above for the valve 2 and the temperature control flap 5 in order to make the most of the savings potential while still providing safety margins for even temperature control.

The embodiment of the system according to 1 has the particular advantage that in the legal exhaust gas test, ie completely switched off heating and air conditioning, a complete shutdown of the heating branch is possible and no potential is given away.

Looking at the cost of the valve 2 and look at the fact that in the customer's hand very rarely a operation occurs completely without heating power extraction shows 3 a particularly advantageous embodiment of the method according to the invention. As throttle body 2 Here, no el. Actuated valve is used, but a purely thermostatically actuated valve, which now in the return of the heating branch or even in a largely cooled zone of the heating heat exchanger 4 is arranged. This valve is eg in the closed end position above + 25 ° C and has a small leakage current to the coolant temperature information to the thermostatic valve 2 to transport. Below 25 ° C, the thermostatic valve opens 2 and tries to regulate the return temperature to + 25 ° C. This ensures on the one hand that at high heat removal at the heat exchanger sufficient flow is applied to satisfy the heating needs and on the other hand, with low heat removal, the flow is throttled so much that the desired reduction of the coolant and component temperatures is ensured throughout the heating. Looking at the map in 2 It becomes clear that this procedure requires a high-performance heat exchanger, which is capable, for example, of delivering the same heat output even at flow rates around 2 l / min as conventional heat exchangers at 10-15 l / min. The additional costs for such a high-performance heat exchanger, however, are put into perspective by the fact that it is needed in any case to fully exploit the potential, thereby additionally simplifying the application significantly. At the same time, the cost savings of the thermostatic valve compared to a el. Valve can be counterbalanced. Given the low cost of a simple thermostatic valve with approved leakage, this approach seems quite attractive.

The Work with basically reduced flow in the heating branch extends in particular the Travel, heating heat exchanger with a higher one Use tube / rib density and, if necessary, the more efficient one To move counter-current construction. Part of the saved pressure loss at lower throughput but especially for that used particularly advantageously, the supply line with a something to provide a smaller cross-section. This does not only result Advantages of the heat-active Mass and surface heat losses, but also at the dead time of the heating temperature control, specifically at very low flow.

to Maximizing the fuel saving potential but also for simplification the application is in particular the combination of the el. valve very advantageous with the thermostatic valve. It does not work only realize the complete shutdown of the heating branch but also expand the control area.

The leakage current and the control temperature of the thermostatic valve 2 in 3 naturally define the upper limit of the air heating temperature at rel. warm ambient temperature. With a very good heat exchanger, a control temperature of 25 ° C is sufficient to manage with and without air conditioning even with very small leakage current. For simpler heat exchangers, it is advantageous to increase the control temperature to about 30-35 ° and / or to increase the leakage current slightly to ensure that always enough heating power is available.

Especially in engines with heating power deficit, but also to maximize the cabin heating in winter, it is particularly advantageous if in the cooling circuit according to 3 with high heating demand, the coolant bypass branch 6b is closed as well as the cooler branch 6a and the venting branch 9a , This is generally advantageous for maximizing the heating effect. In connection with the system according to the invention in the variant with high-performance heat exchanger, however, the Heizleistungsvorteile are still much larger, since now with a correspondingly low coolant throughput and the average heat-reactive mass of the engine is significantly reduced.

In the particularly advantageous cooling system according to 4 comes to this the bypass valve 6bv used and it is a laying of the return from the water tank 9 on the cold side of the radiator thermostat 6 he follows. At high heating demand and low engine power, the valve 6bv closed, so that not only the heat-active effective mass of the heating branch is minimized, but also the heat-reactive mass of the engine. As soon as there is a heat surplus for the cabin heating, it is particularly advantageous in this arrangement to additionally throttle the coolant mass flow in the heating branch. Depending on the engine type, it is then best for a fuel consumption optimal operation, the bypass valve 6bv Keep closed to the smallest possible heat-active To realize mass in the heating branch. This is advantageous in engine designs in which the extremely low return temperature over engine internal flow processes and in particular by natural convection in the engine interior largely compensates. The drop in the water-side heat transfer coefficient in the water jacket of the cylinder liners then makes an additional contribution to saving fuel, in particular via the savings in friction losses of the piston group and via an increased heat transfer to the engine oil.

On the other hand, in engine types where engine-internal compensation flows are less pronounced, it is particularly advantageous to use the bypass valve 6bv open to ensure heat transfer from hot spots of the engine cooling circuit, in particular from the cylinder head or optionally from the exhaust gas recirculation cooler, to the engine inlet and thus also to the cylinder liner.

It is particularly advantageous, the bypass valve 6bv open only partially or clocked and thus ensure that only as much coolant flows through the engine, as is necessary for a sufficient heat transfer from the cylinder head to the engine inlet. Especially with low to medium heat removal at the heating heat exchanger 4 Here, at low engine load, in general, a fraction of the flow rate applied to the engine when the bypass valve is fully open is sufficient. A look at the expected when minimizing the heat-active mass in the heating branch coolant flows 2 shows that even a few l / min bypass flow are sufficient to raise the coolant inlet temperatures at the engine inlet to approximately the engine outlet temperature level. An example calculation should clarify this: Coolant flows at 80 ° C at the engine outlet in the heating heat exchanger branch 4a and is cooled at a coolant flow rate of 0.5 l / min to + 7 ° C, it is sufficient when the thermostat is closed 6 a bypass volumetric flow 6b of 5 l / min around the motor inlet temperature at the pump 7 to 73 ° C, ie there is then a largely homogeneous coolant temperature in the engine of 73-80 ° C before. For example, compared to a conventional cooling system, the engine coolant flow rate is 50 l / min, ie 15 l / min from the heater branch 4a and 35 l / min from the bypass branch 6b , dropped to 5.5 l / min. Current correlations for the rough estimate of the heat transfer in the water jacket of the cylinder liner show a correlation of the heat transfer coefficient α with the Reynolds number and thus the coolant throughput or the flow velocity u of α ~ u ^0.8 , so that with this rule of thumb for the transition of 50 l / min to 5.5 l / min gives a theoretical difference of the water-side heat transfer by about a factor of 6. Even if the above correlation, especially in the direction of very low flows, predicts a somewhat too great drop in the heat transfer, the practice shows the fundamental correctness of this consideration. With the significant drop in the heat transfer coefficient is not only accompanied by a significant increase in the temperature of the cylinder liners, but ultimately a faster heating of the engine oil. Both effects have a positive effect on fuel consumption not only in the early phase of engine warm-up, but also during prolonged driving with low engine load and heat output.

Upon reaching engine outlet temperatures above the thermostat opening temperature, for example, 85 ° C is especially at low heat removal at the heat exchanger 4 quickly reached the point at which the clocked opening of the bypass valve 6bv the radiator thermostat 6 opens. Controlled mixing of bypass volume flow 6b with the heating volume flow is made from this point significantly more difficult now that now 3 volume flows and the temperature-dependent opening of the radiator thermostat 6 in determining the clock frequency or opening time of the bypass valve 6bv to take into account. Especially in applications where as a throttle body 2 in the heating branch 4a an el. switchable valve is used, it is particularly advantageous against this background, when partially opened or fully opened in operating situations with excess heat after reaching a minimum temperature of the coolant flow in the heating branch.

It is to avoid temporary undercooling of the engine particularly advantageous if the flow rate increase in the heating branch is such that during the transition to high flow, the bypass valve 6bv at least temporarily open.

Around the temporary one pour in cold coolant from the cooler branch It is particularly advantageous to avoid this switching at coolant outlet temperatures from the engine below the thermostat opening temperature of, for example 85 ° C.

With a small excess supply of engine waste heat, the bypass valve 6bv closed again when the coolant temperature at the engine outlet continues to rise to values well above the thermostat opening temperature, so that only the flow and the temperature in the heating branch 4a the extent of the opening of the radiator thermostat 6 and thus define the heat release to the environment. For a high control quality of the engine coolant temperature at a raised temperature level, it is particularly advantageous if the coolant throughput in the heating branch 4a by means of of the el. valve 2 throttled to values that just cause a sufficient cooling effect for the engine. Especially in connection with a already designed for reduced total throughput heat exchanger here is a wide range of engine part load operating points with and without heating can be found in which the thermostat 6 automatically makes a very sensitive throttling of the coolant flow rate through the engine. The low heat transfer coefficient in the water jacket of the cylinder liner at the low total flow through the engine, due to the closed bypass valve 6bv and the minimal open radiator thermostat 6 ultimately, lead to the desired increase in component and oil temperatures. With conventional radiator thermostats and a large cooling potential of the vehicle radiator, the coolant temperature difference between the engine inlet and engine outlet is in the range around 20K.

In some cases, operating conditions are also achieved with this approach, where actually a slightly higher coolant throughput would be desirable to avoid potential engine overheating or especially at relatively low heat surplus of the engine and already largely lowered coolant flow - and thus largely lowered heat transfer coefficient - a higher temperature to achieve at the engine entrance without the vehicle radiator 8th to open. In a particularly advantageous embodiment of the method according to the invention is therefore proposed, the coolant return line of the heating branch downstream of the radiator thermostat 6 and upstream of the engine coolant pump 7 to arrange. This is a far-reaching decoupling of the opening of the radiator thermostat 6 accompanied by the flow through the heating branch, so that now at low heat extraction on the heating heat exchanger 4 may well set the coolant temperatures at the engine inlet far above the opening temperature of the radiator thermostat. The gain in bandwidth for by means of the bypass valve 6bv and the throttle body 2 Adjustable engine component temperatures is quite significant. To compensate for the disadvantages caused by the interaction of the radiator thermostat 6 with the heating return in important engine part load points no longer automatically provides a very sensitive temperature control, by an el. Actuation of the valve 2 can be stepped very sensitively, is a correspondingly more precise control of the bypass valve 6bv taking particular account of local flows and temperatures.

These statements on the example according to 3 show that the procedure according to the invention especially in conjunction with an additional valve 6bv has a significant potential for fuel economy. The costs for the design according to 3 limited in the simplest case to the bypass valve 6bv and the thermostatic valve 2 in the heating branch or, alternatively, a second el. valve 2 in the heating branch and are well below the cost of alternative fuel economy saving technologies.

The practical implementation of the measures according to 3 Taking full advantage of the indicated fuel saving potential requires - with all the simplicity of the components - a not to be underestimated application costs. Especially when dosing the bypass valve 6bv in the range above the thermostat nominal temperature of, for example, 85 ° C is a certain potential for error in the application, including accidental or excessive opening of the cooler branch, associated with losses in fuel economy. In addition, there is also the danger here that too high demands on the component and the control consume a not negligible part of the cost advantages. This statement applies to the in 4 shown integration of the heating return and reinforced for the integration of the heating return downstream of the thermostat. A motor-related analysis can only show if it is not more cost-efficient, a somewhat inaccurate dosing bypass valve 6bv to use and thus still to realize the majority of the advantages of the system according to the invention.

Another particularly advantageous embodiment of the method according to the invention can be found in 5 , In addition to 4 you will find here the additional bypass 6c , parallel to the bypass branch 6b with bypass valve 6bv , which is not on the radiator thermostat 6 ends, but downstream, preferably directly in the vicinity of the pump inlet of the engine coolant pump 7 , In the simplest form, this is a small-diameter pipe with a corresponding throttling action or a pipe with a thermostatic valve 6cv , which opens eg from 60 ° C coolant temperature. Instead of the external line 6cv also internal engine channels can be used.

In both cases, ie with and without thermostat 6cv , the flow is in the bypass branch 6b with closed radiator thermostat 6 and opened by-pass valve 6bv many times larger than in the additional bypass branch 6c , This requirement with regard to the flow is important on the one hand for a good heat output and for limiting the flow-dependent cooling effect on the cylinder liners with and without heating. On the other hand, this also ensures that with high cooling demand, ie when closing the bypass branch 6b , a sufficient amount of coolant through the vehicle radiator 8th flows.

At first glance, this is a bit complicated Lich acting design of the cooling system is therefore particularly advantageous because it with closed bypass valve 6bv in a first setting, an improved heating effect with reduced fuel consumption allowed and in other settings with partially far below the maximum heat output reduced coolant mass flow in the heating branch and only in case of overheating danger opened by-pass valve 6bv a minimization of the fuel consumption taking into account the respective heating power requirement up to the legal exhaust gas test without heating.

In terms of maximizing heating power is the auxiliary thermostat 6cv particularly helpful because it ensures that the main coolant flow through the heater core up to a minimum temperature of the engine side coolant 4 goes and thus - over the limitation of the total throughput by the engine - at relatively low cooling water inlet temperatures of the engine and the engine itself is a very strong temperature stratification. That is, the heat-active mass of the engine is minimized as well as the heat-active mass in the heating branch. The bypass branch 6b and the venting branch 9a and the cooler branch 6a are closed here anyway.

In many applications, but is also without the additional thermostats 6cv sufficient heat output is available under all winter driving conditions, so that it can be more fuel-efficient in operating situations with high heat extraction in some engines, on the thermostat 6cv to renounce. It is even better in terms of switching between fuel consumption and optimum heating performance, the thermostatic valve 6cv to be replaced by a demand-driven by the engine control el. valve. In most applications, however, for cost reasons, no valve or thermostat will be used.

A certain amount of fuel savings with the cooling and heating system according to 5 As already described, has the fact that the cold return of the coolant in the heating branch upstream of the point of introduction 7e the additional bypass 6c lies and that the engine coolant bypass 6b so in the environment of the radiator thermostat 6 is arranged, that the coolant flow during electrical opening of the bypass valve 6bv on the expansion element of the radiator thermostat 6 flows past. In conjunction with the inventive design of the heating circuit, even with low heat removal at the heating heat exchanger 4 provides a temperature of the recirculating coolant well below the thermostatic opening temperature remains the radiator thermostat 6 if necessary, ie without opening the bypass valve 6bv , closed to very high engine temperatures. Thus, it remains in the arrangement according to 5 only the engine control 16 to determine the effective thermostat opening time by bypassing the engine coolant 6bv opens: Since the bypass coolant flow 6b designed to be much larger than the heating medium flow, defined when opening the bypass valve 6bv the engine coolant temperature the opening of radiator thermostat 6 , In this way, by means of the bypass valve 6bv depending on the engine load between an increased engine coolant temperature, for example, 110 ° C and a lower coolant temperature, for example, 85 ° C back and forth. The introduction of the targeted cold held heating return upstream of the discharge point 7e the additional bypass 6c acts in this context as a thermal barrier layer, so that the thermostat is not heated by heat conduction or natural convection to such a temperature level that he occasionally unintentionally Opens and releases cold water from the radiator. Since almost always a certain heat removal takes place at the heating heat exchanger in practical driving, this is a particularly robust protection against unintentional opening of the radiator thermostat available.

In 4 is like in 3 as throttle body 2 a thermostatic valve especially cheap. But it can also be an el. Valve with appropriate control use. In this case, it is particularly advantageous to provide a failsafe protection that in case of too high engine temperature, eg due to a failure of the bypass valve 6bv the valve 2 completely opens and so to an at least partial opening of the radiator 8th leads.

When using an el. Valve 2 this is in the statutory exhaust gas test, ie without heating, at least until reaching critical component or coolant temperatures, preferably completely closed. The advantage of the thermal barrier layer is then no longer, but at least no active heat transfer takes place at the radiator thermostats 6 that opens this unintentionally.

The additional bypass 6c , with the removal of the coolant from warm or overheating vulnerable zones of the cooling system or engine and its specific mouth at the position 7e downstream of the radiator thermostat 6 and upstream of the engine cooling water pump 7 costs without the additional valve 6cv or from its opening, of course, some potential to maximum heating power in winter, since it reduces the temperature stratification of the engine.

UU also results in a minimal loss of maximum cooling capacity, since with closed bypass branch 6b a larger partial mass flow not through the vehicle radiator 8th flows. The targeted di dimensioning to a much lower flow in the bypass branch 6c compared with the bypass branch 6b in the open state, it is necessary to make the motor dependent on this background and with due care.

In return, however, then results in a total system, which not only has a better wintry heating compared to today's standard cooling and heating systems, but with reduced heat removal from the heater has significant fuel economy benefits due to faster engine heating. In addition, this not only reduces the risk of local overheating when the bypass valve is closed 6bv reduced but it is also greatly improved the control quality of the engine temperature. It is only the comparative effect of the flow in the branch that makes this possible 6c the use of a relatively coarse dosing and slow bypass valve 6bv and considerably simplifies the application effort. As tests show, many standard radiator thermostats tend 6 with typical opening temperatures between 80 and 90 ° C in addition, with an excessive flow with a previously closed bypass valve 6bv On example 110-120 ° C heated coolant, to open briefly and to allow an excessive amount of cold coolant to flow into the inner engine cooling circuit. Strong fluctuations in the engine component temperature and in particular thermal stratification with undercooled cooling water in the lower engine zones and on the cylinder liner can result from this, combined with losses in fuel economy.

Pulsed or only partial opening of the bypass valve 6bv Although this provides a partial remedy, but as already described increases regulatory overhead and component costs.

The specific advantages of in 5 integration of the heating return line shown in the effective range of the radiator thermostat 6 have already been described. In conjunction with the additional bypass branch 6c with and without additional valve 6cv There are advantages that justify the additional costs for this unusual design in many applications. Especially the advantages when the coolant temperature in the engine is the thermostatic temperature of the radiator thermostat 6 of 85 ° C, for example, are quite substantial and should be underpinned once more with some exemplary numerical values:
In a conventional cooling system in cars without a bypass valve 6bv and without additional bypass branch 6cv In the engine part load and engine speeds of 1500 to 2000 l / min, a distribution of about 15 l / min through the heater branch and 35 l / min through the bypass branch is a common distribution with the radiator thermostats closed or only slightly open 6 ,

By way of example, consider a thermally stable operating point with 5 kW heat surplus at the engine and without heat removal at the heating heat exchanger 4 , ie the excess heat must be on the vehicle radiator 4 With a conventional cooling system and constant travel with an 85 ° C radiator thermostat, this leads, for example, to 1-3 l / min throughput in the vehicle radiator. The total coolant flow through the motor is approximately 50-55 l / min with the thermostat slightly open. Closing the bypass valve 6bv reduces the total volume flow through the motor assuming a typical pump characteristic to about 20 l / min. The control characteristics of the radiator thermostat 6 and the over-dimensioning of the vehicle radiator, which occurs at a moderate driving speed, ensure that the coolant temperature at the engine inlet is close to the thermostat nominal temperature of 85 ° C. At 5 kW heat absorption of the coolant in the engine, the coolant temperature rises to approximately 88-89 ° C until the engine exits under thermally stable conditions. This temperature level is well below the value that is desirable at this partial load point for optimum fuel economy. 110-120 ° C are here more desirable temperature values. The use of an el. Heated map field thermostat in previously known design is quite able to provide such a temperature level of the cooling water within the engine, but has the disadvantage that he does so at a total coolant mass flow of 50-55 l / min and thus the Component temperature due to the increased heat transfer coefficient does not increase as much as it would help to optimize consumption. A further increase in the coolant temperature level above 120 ° C is not effective, especially for security or cost reasons. In addition, the el. Thermostat known to have the disadvantage that when switching to low component temperatures at sudden full motor load an undesirably long delay time can occur.

The inventive combination of throttling the coolant flow in the bypass branch 6bv and in the heating branch helps to overcome the problems described above and is therefore superior to the el. Heated thermostat in this point as well as the switching speed to low component temperatures. For this purpose, first the bill without additional bypass line 6c : A throttling of the coolant throughput in the heating branch to, for example, 1.5 l / min delivers when the bypass valve is closed 6bv For example, about 1.5 l / min cooler flow, so that a total of 3 l / min flow through the engine. Due to the system, the radiator thermostat delivers coolant of only slightly more than 85 ° C, so that in view of the 5 kW heat absorption In the engine an engine exit temperature of about 114 ° C results. The average engine coolant temperature is thus slightly lower than with the el. Heated thermostat. Nevertheless, the increase of the engine component temperature and the engine oil temperature due to the smaller by about the factor 16-18 smaller coolant throughput and thus drastically reduced water-side heat transfer coefficients or better than the el. Heated thermostat. The reserves for an ultrafast switching to high cooling capacity by opening the bypass valve 6bv or, if necessary, also the el. operated heating valve 2 are obvious. This increases the heat transfer coefficient and thus the cooling effect without time delay and is partly due to the subcooled zones in the bypass branch 6bv still supported. Moreover, compared to the operation with high coolant throughput, primarily the combustion chamber near zones of the engine structure and thus also the cylinder path at elevated temperature level and not the entire engine structure including the coolant, so that when switching to low component temperatures less engine mass must be cooled. As tests show, the opening of the vehicle radiator branch takes place so fast that no problems with engine overheating in case of sudden full load are to be expected here.

These specific advantages with low total coolant flow through the Engine come especially to bear when the engine at steady-state operating temperature is and excess heat to be dissipated got to.

Especially with incomplete engine warming, very low excess heat and high heat extraction at the heater core minimizes the total coolant flow through the engine to very low flow values, associated with very high temperatures in the cylinder head and very low coolant temperatures at the engine inlet and strong engine-dependent temperature level at the cylinder bore. With a change in the coolant velocity in the direction of zero, the gain in the heat transfer is initially significantly reduced by the transition to laminar flow until finally, due to the dominance of the superimposed natural convection, a further reduction of the throughput no longer results in a reduction of the heat transfer. Thus, the gain in the heat transfer coefficient at extremely low inlet temperatures in some engines can not overcompensate the disadvantages of the low coolant inlet temperature. Here it is often cheaper to increase the flow again something and, for example, with a temporary opening of the bypass valve 6bv or with increasing the coolant flow rate in the heater branch for a slightly increased overall throughput through the engine. Is the return temperature of the heating branch 4a or the coolant temperature in the bypass branch 6b however, above the thermostat opening temperature of, for example, 85 ° C, this results in the arrangement according to 4 especially at very low engine surplus heat and in particular already in the heating phase of the engine coolant from, for example, 85 ° C to 115 ° C to unintentional losses due to premature opening of the radiator thermostat 6 , As already described, the laying of the return line of the heating branch to a position downstream of the radiator thermostat helps here 6 , However, this is, among other things, associated with certain disadvantages in terms of control quality and fail-safe behavior.

Referring now to the computational consideration of the additional bypass branch 6c Thus, an exemplary additional mass flow of 5 l / min in the additional bypass branch leads to a considerable reduction in the temperature inequality distribution within the engine. The additional bypass line ensures targeted heat transfer from the cylinder head to the cylinder block without leading to an unintentional opening of the thermostat. The mixture of 3 l / min coolant from heating and radiator branch with approximately 85 ° C with the 5 l / min in Zusatzbypasszweig 6c In this calculation example, the result is a stable operating point of approx. 102 ° C at the engine inlet and 113 ° C at the engine exit. Slight variations in the throughputs and the amounts of heat transferred in the radiator and heater branches have a significantly lower effect on the control quality of the engine component temperature. With a total engine throughput of 8 l / min, the heat transfer coefficient is still well below the base at 50-55 l / min, with the coolant inlet temperature increased from 85 ° C to 102 ° C compared to the constellation of 3 l / min total flow Disadvantages largely eliminated by the slightly increased heat transfer coefficient.

For analogue bills with even lower total coolant flow rates through the engine, as they are facing 2 In practice, quite often to be expected, falls the cylinder barrel temperature with bypass branch 6c For many engines ultimately even higher than without bypass branch 6c because here the effects already described above under the dominance of the natural convection on the water-side engine-internal heat transfer in the foreground.

The previous versions too 5 have focused to a great extent on operating conditions with heat emission to the radiator and possibly on the vehicle radiator. But even in the warm-up phase and without any heat loss on the radiator 8th is the arrangement according to 5 especially advantageous. This is particularly true of the fact that too cold motor entstems Temperature and too high a temperature spread with disadvantages in terms of mechanical stress and cold cylinder running on the engine are then absolutely sure avoided when an extreme cooling in the heating branch to turn off the heat-active mass of the heating branch, ie risks of incorrect application over the permissible mechanical limits of the engine Be minimized with it.

Especially in the legal exhaust gas test without heating and preferably with an el. Valve 2 switched off heating branch 4a provides the additional bypass 6cv sure that the bypass valve 6bv or the heating valve 2 only at very high coolant temperatures must be opened well above the thermostat opening limit. The danger of unintentional heat dissipation via the vehicle radiator does not even exist in many areas of the exhaust gas test and even with a rather crude control strategy and inexpensive bypass valves 6bv For example, the EUDC of the MVEURO can also be operated with well-dosed cooling effect.

It is particularly advantageous if, in the early phase of the exhaust gas test, the additional valve 6cv the flow of the engine is completely prevented and only after reaching a minimum coolant temperature in the engine opens and ensures heat transfer from the cylinder head to the cylinder block or the cylinder bore with minimal heat loss to the environment. The compared to the bypass branch 6bv smaller cable cross-sections, the smaller dimensions of a corresponding valve 6cv and the partial elimination of heat losses for Teilerwärmung the thermostat 6 and the line section to the point 7e help here in particular for a largely lossless and low-dead time transport of heat, even at relatively low flow selected in the additional bypass branch 6c ,

The initial flow velocity zero is especially advantageous because even in the cylinder head no warmer coolant is available than in the block. In this phase, rather, the relatively high friction losses on the cold cylinder bore dominate the raceway temperature and the heat balance, so that any convective cooling is harmful here. This procedure with the option the heating branch with an el. Valve 2 switching off completely is particularly advantageous in the legal exhaust gas test.

In contrast, the Real World operation is in the foreground, ie it is almost always a heat extraction at the heat exchanger 4 before, as already mentioned, the variant with a thermostatic valve as a throttle body 2 more cost effective. For engines with heat deficit or if a particularly good heating effect of the vehicle is in the foreground, you will be the additional valve 6cv Use it to close the additional bypass branch at the engine outlet to a minimum coolant temperature of, for example, 60 ° C and thus to realize the maximum heating power.

The heating effect, however, is sufficient anyway and comes as a throttle body 2 a cost-effective thermostatic valve is used, so it is with design focus on the fuel consumption especially when designing the additional bypass branch 6c most effective at relatively low throughput, all the way to the valve 6cv to renounce. Even with the resulting system due to low heat recovery very cold return temperatures in the heating branch is after mixing the two coolant flows from the branch 6c and 4a at the engine entrance only a moderate subcooling relative to the engine exit before. The basic design of the coolant flow in the branch 6c to relatively low values, in particular aims at the fact that the total coolant flow through the engine with closed bypass valve 6bv lies in the area where a reduction of the flow only brings a limited reduction of the heat transfer. With low heat removal at the heat exchanger is the flow in the heating branch 4a so low that already has a base throughput in the branch 6c of 2-5 l / min is sufficient to realize significant fuel economy benefits.

The entire system can be tuned particularly sensitively in the direction of optimal fuel consumption, albeit the additional bypass branch 6cv having a control of the coolant flow rate. In the simplest case, this takes place again by electrical means, ie via a valve which can be metered by the engine control 6cv ,

This provides for fuel consumption optimal operation especially at high heat extraction in the heating branch and / or high excess heat at the engine an increased additional bypass flow in the branch 6c one and at low excess heat with low heat removal in the heating branch a reduced additional bypass flow in the branch 6c ,

With high cooling requirement and opened bypass valve 6bv closes the el. additional bypass valve 6cv initially not to the scheme with timing of the bypass valve 6bv to support or to dampen temperature fluctuations. Only when a very high cooling effect is needed, the valve closes 6cv to the coolant flow through the vehicle radiator 8th to maximize.

With systems according to 5 In particular, the application costs and the Kos are reduced for the bypass valve 6bv including its activation. In addition, the system is particularly suitable for very high coolant temperatures at the engine outlet without unintentionally opening the radiator thermostat 6 adjust. It is characterized in particular by the fact that, if required, even very high coolant temperatures are present at the engine inlet. These high coolant temperatures at the engine inlet can be at engine part load in particular with and without heat dissipation on the vehicle radiator 8th to adjust.

The high coolant temperature mode of operation with variable coolant flow rate through the engine is one of the most particular strengths of this design. Previously known cooling systems with thermostatic control of the vehicle radiator 8th are unable to deliver a comparatively high average component temperature level in the lower engine part load range. Thus, for example, in the conventional el. Heated map thermostat with comparable coolant temperature, the coolant throughput and thus the cooling effect is much higher than in the system according to 5 can be adjusted. In particular, in contrast to the embodiment according to the invention, the total coolant throughput through the engine can not be influenced by the engine control, so that different component temperatures can be realized at the same maximum coolant temperature.

Around Depending on the design variant, this can be covered by engine load and engine speed dependent map local component, coolant and oil temperatures one has previously assumed that an expensive el. adjustable coolant pump as a replacement for the engine coolant pump in conjunction with a el. heated map thermostat or even with an el. infinitely variable rotary valve thermostat instead of the much cheaper standard radiator thermostat with Dehnstoffaktuator needed becomes.

In a further refinement of the cooling and heating system according to the invention 6 two more coolant branches 6d for an optional engine cooler 30 and 6e for an optional transmission oil cooler 40 , Again, make optional thermostats 6dv and 6EV or el. valves sure that with cold coolant on the one hand, the heating power is improved and the other during warm-up, the available heat first the engine or its cylinder linings is good. Again, it is particularly advantageous to ensure a suitable dimensioning of the components and cable cross-sections that the total coolant flow rate of the branches 6c . 6d . 6e with a warm engine is significantly smaller than in the open bypass branch 6bv , so that with the cooling effect of the cooler just as little problems occur as with the control quality of the radiator thermostat 6 , This is especially important with several additional branches, since the thermostat is at a mixed temperature of the cooler branch, heating branch and bypass branch 6b adjusts. This control temperature is the more inaccurate the larger the internal currents in the branches 6c . 6d and 6e are and can in extreme cases be several ° K lower than the effective engine coolant temperature without the internal "short circuits" 6c . 6d . 6e , El. switchable valves 6cv . 6dv and 6EV help to alleviate this problem, if necessary, but you will still choose to minimize the heat-active masses and for a dead-time response significantly smaller cross-sections than for the bypass branch 6bv In particular, according to the invention, the total coolant throughput through the engine should be significantly smaller than when the bypass valve is open 6bv ,

In terms of the cost-benefit ratio in this context is ia the restriction to thermostatic valves for the branches 6e and 6d the cheapest. The already described tasks of the additional bypass branch 6c may also be from one of the branches 6d or 6e at least partially taken over.

For best fuel economy with one el. Valve 2 switched off heating branch 4a It is particularly advantageous if, starting from the cold engine operating state, no coolant initially flows through the engine, then at a first switching temperature of the coolant, the additional bypass branch 6c opens, at a second switching temperature of the oil cooler bypass branch 6d opens and after further engine heating at a third switching temperature of the transmission oil cooler branch 6e , The inventive dimensioning of the branch 6c on low flow and a similar procedure in the branches 6d and 6e Make sure that by opening the bypass valve 6bv Sufficient motor cooling is always adjustable and that the control temperature of the radiator thermostat does not lead to an inadmissible increase in engine inlet temperatures.

Especially provides the preferred embodiment of the system with high performance heat exchangers and lowering the coolant flow in all heating heat exchanger operating points, for this, that even in the most diverse situations with heating operation there is a reduced total flow through the engine exceeding the Lowering the heat transfer coefficient provides a fuel economy advantage in the water jacket.

Especially the integration of the branches 6c . 6d . 6e and if necessary also the heating branch 4a at the point 7e in front of the engine coolant pump 7 and behind the radiator thermostat 6 thus results in the interplay with the bypass valve 6bv , which in contrast to the mentioned branches when opening directly on the radiator thermostats 6 acts, the necessary degrees of freedom, the coolant temperature within the engine by means of the engine control 16 if necessary to temperatures far above the actual opening temperature of the radiator thermostat 6 of for example 85 ° C. At the same time, the engine's total coolant flow rates preferably remain at reduced values over a wide part load range of the engine, unlike conventional heated thermostat systems, which provide fuel economy benefits in the lower part load range and throughout the warm-up.

The system is according to 6 In particular, characterized in that the high coolant temperatures at the engine outlet, which are achieved particularly quickly by the minimization of heat losses according to the invention favor the heating of the engine oil or the transmission oil during warm-up and in particular a premature heat release is avoided on the vehicle radiator. A conventional integration of the cooling water flowing back from the oil cooler at the heating return or at the bypass branch 6b would in this context very quickly to unintentional opening of the radiator thermostat 6 to lead.

It is obvious that the tuning of the coolant flow rates through the engine oil cooler 30 and the transmission oil cooler 40 requires a certain care in order not to get an insufficient heat transfer in the respective heat exchangers due to low cooling water throughputs despite high flow temperatures, so that ultimately but the bypass branch 6b must be opened prematurely to avoid potential engine overheating.

Conversely, the interactions described above exist that largely limit the coolant flow rate through the two oil coolers 30 and 40 suggest or require. Against this background, working with high-performance heat exchangers 4 and basically limited flow very helpful to defuse this conflict of objectives. But also conventional heating heat exchanger with the throttling according to the invention via el. Valves 2 help here in wide map areas to limit the coolant flow rate through the engine and yet on one for the oil cooler 30 and 40 meaningful level. It helps in particular that the procedure according to the invention specifically according to 6 leads to very high oil inlet temperatures, so that no oversized oil cooler are required. In particular, there is respect 6 the already mentioned cost saving potential, the additional bypass branch 6c to be omitted and after initial coolant shutdown directly one of the oil cooler branches with a thermostatic valve 6dv respectively. 6EV to open.

To further defuse this conflict of interest regarding the flows in the engine and by the oil cooler shows the particularly advantageous embodiment according to 7 the option of one or both oil coolers 30 and 40 so that you can connect the coolant directly to the pump outlet of the engine coolant pump 7 or directly in the vicinity of the engine inlet. The total coolant throughput through the engine is thus at the relevant for the water-side heat transfer points back to the flow in the additional bypass 6c limited, so that inside the engine again the desired reduction of the heat transfer coefficient takes place with simultaneous heat transfer from the cylinder head to the cylinder block or to the oil cooler 30 and 40 over the line 6c , The system according to 7 is particularly attractive because it not only significantly higher coolant flow rates through the oil cooler 30 and or 40 but also a higher pressure gradient is available to work with slightly smaller oil coolers. The slightly lower oil temperature compared to the integration according to 6 is here in favor of the higher Ölkühlerdurchsatzes and to minimize the coolant throughput through the engine and other benefits accepted. In the overall system in particular the important advantage is added that with open branches 6d respectively. 6e short-term cold water phases due to excessive opening of the bypass valve 6bv and thus the radiator thermostat 6 are damped much stronger than systematically with the additional bypass branch 6c anyway accomplished. A very uniform engine component temperature over time and this at a consistently elevated level is thus even with certain control weaknesses of the valve 6bv ensured. The same applies to strong fluctuations in the throughput and temperature level of the heating branch.

The advantages of this specific integration of the oil cooler 30 and or 40 Regarding the quality of control are so significant that it is easily possible with a connection of the heating return at the position 7e to work, as in 8th shown. The above-described, possibly greatly cost-increasing measures on the design and control quality of the bypass valve 6bv ia are not necessary here. This statement applies in particular to the preferred variant with high-performance heat exchangers and reduced base flow as well as for the variant with conventional heating heat exchangers with a high base coolant flow and el. Controlled valve 2 in the heating branch.

Even with elimination of the throttle body 2 in the Heating branch is the system with bypass valve 6bv , Bypass branch 6c and integration of the heating return to the position 7e even more fuel efficient than conventional systems with non el. controlled bypass branch 6b , This is especially because of premature opening of the radiator thermostat 6 is avoided and beyond the total coolant mass flow through the engine compared to the base without bypass valve 6bv or smaller with opened bypass valve. A conventional integration of the heating return at the inlet in the radiator thermostats 6 would in this context at high coolant temperature and high throughput through the heater or without throttling and heat removal at the heat exchanger 4 due to the high return temperature in many operating points to premature opening of the radiator thermostat 6 to lead.

As already described in detail, the additional bypass helps 6c here too, in cases where due to high heat extraction at the heating heat exchanger 4 and rel. small heat exchanger flow could cause subcooling on the engine to save fuel. In addition, it also serves to equalize control fluctuations in temporary opening of the bypass valve 6bv ,

A particularly versatile and less sensitive configuration shows 9 with additional integration of a motor oil cooler 30 and a transmission oil cooler 40 , With high performance heat exchangers and low base flow design, this system can be used very efficiently to improve fuel economy but with some sacrifice even with very conventional basic heat exchanger heat exchangers. It is clear that, with regard to the achievable in daily driving bandwidth of fuel savings in a variety of driving conditions and different Wärmieistungsentnahmen the heat exchanger, systems with throttle body 2 in the heating branch for both variants are better. Conversely, however, such systems with integration of the heat exchanger return downstream of the radiator thermostat and bypass valve 6bv with additional bypass branches 6c , and in particular additional bypass branches 6d and or 6e with integration according to 9 for cost-limited consumption saving measures still very attractive. This is not least due to the somewhat lower demands on the heating heat exchanger 4 , the saving of an active throttle body 2 and the relatively low application cost, which allows a quick and easy application to a variety of engine-vehicle combinations.

A very special advantage of the constellations according to 7 - 9 This is because it is very easily possible to trim these for either improved cabin heating or improved fuel economy. For this purpose, in particular measures are available that heat transfer in the engine oil cooler 30 promote, prevent or even reverse. The simplest implementation is done here with a el. Of the engine control 16 operated valve 6dv ,

The possibilities are manifold here and should be based on an example only 7 be explained. The valves 6cv and 6EV Thermostat valves are now the branch at 60 ° C 6c open and at 70 ° C the transmission oil cooler branch 6e , The valve 2 be an el. of the engine control 16 controllable valve, as well as the valve 6dv of the engine oil cooler branch 6d ,

To maximize the heating effect comes a high performance heat exchanger 4 For use with a throttled to 2 l / min, for example, coolant flow rate. At high heat extraction thus the coolant return temperature of the heating branch is greatly lowered.

To maximize the heating effect here is the valve 6dv closed first for a few minutes until an increase in the oil temperature has set above the return temperature of the cooling water in the heating branch.

A simple opening of the valve 6dv then causes an improvement in the heating effect, since now the cooling water extracts heat from the engine oil. This keeps the oil and engine parts in contact with oil a little cooler, which reduces the heat loss to the environment. UU motor friction at the bearings is slightly deteriorated. However, the overall balance in terms of fuel consumption is largely neutral in view of the low coolant flow rate of only 2 l / min and the now somewhat preheated coolant at the engine inlet. In the end, the lower heat losses for engine and engine oil heating and the lower surface heat losses on the engine surface, including the oil sump, result in faster coolant heating at the engine exit, and thus better heater performance. Maintaining cabin heating power and, in addition, reducing air flow 20 , which is possible in view of higher cooling water flow temperatures, can then ultimately achieve further fuel savings.

In contrast, it provides permanent closing of the valve 6dv from the beginning until the heating has been cut off due to excess heat in the cabin, there is a middle ground between good heating and good fuel consumption, with engine coolant temperatures above 60 ° C temperature of the thermostatic valve 6cv in the additional bypass branch 6c and after adjusting the heating, the fuel consumption reducing heat exchange between engine oil and coolant by opening the et in this example. controlled valve 6d is activated.

It has already been discussed several times that the valve 6cv optionally omitted in the additional bypass branch or its function at least partially in the valve 6dv or 6EV the two oil cooler branches 6d or 6e can be integrated. In the simplest case, the flow path is merely a corresponding flow channel from the cylinder block to the pump housing or a small line which is used for cooling additional components, in particular the turbocharger. The great importance of small cross sections in the pipes 6c to minimize the heat-active masses and dead times for the heat transfer has also been discussed in detail, as well as the need to ensure that if the radiator is fully open the main coolant mass flow should pass through the radiator and not through the internal bypass branches, not even the radiator thermostat 6 to intervene in the normal routine.

Depending on the specifications for the vehicle, it is still cheaper than alternative solutions - if these exist at all - the valve 6cv also to allow a little more elaborate and an et. Actuation of the valve 6cv to provide, for example, as in 10 and 11 explicitly by the dashed line connecting the valve 6cv for engine control 16 is shown. With such arrangements, the maximum control margin for the coolant flows through the engine and the individual heat exchangers in the cooling system, in particular the heating heat exchanger can be 4 , the engine oil cooler 30 and the transmission oil cooler 40 and the vehicle radiator 8th and optionally realize the exhaust gas recirculation cooler and other components.

Also, a very wide control range at slightly cheaper costs in this context, the embodiment according to 12 in which the valve 6cv is a differential temperature control valve and in particular includes a sensor actuator, which detects the temperature difference between engine inlet and engine outlet and ensures that the temperature difference is not greater than a defined default value. In the embodiment shown, this is a first minimum sensor volume flow in the branch 6t1 led to a first Dehnstoffzelle and tempered these and a second minimum sensor volume flow to a second Dehnstoffzelle. The two partial streams are then eg over the line 6T3 derived. The appropriate superposition of both sensor cell deflections then ultimately provides the desired differential temperature control. In the simplest case, the overlay takes place via a common membrane, which separates the two cells, and then opens or closes the valve via a plunger. Of course, this is just one of the many conceivable methods of differential temperature control.

Depending on the engine, usual differential temperature set values for good fuel consumption are usually between 2 ° K and 10 ° K differential temperature. If it is ensured in particular that the differential temperature control becomes active only at 60 ° C, and the control valve 6cv remains closed until then, so are when the bypass valve is closed 6bv also the Heizleistungsverbessernden aspects of the cooling and heating system according to the invention largely usable.

• 1. Die angesprochene Serienanwendung weist insbesondere eine el. Kühlmittelpumpe, anstelle einer riemengetrieben Kühlmittelpumpe 7 auf.
• 2. Es kommt ein el. beheizter Kennfeldthermostat zum Einsatz, anstelle des konventionellen Thermostaten 6.
• 3. Der Kennfeldthermostat sitzt wie der Kühlerthermostat 6 in 11 zwischen Kühleraustritt und Motoreintritt und hat einen Bypasszweig 6b, jedoch im Gegensatz zu 11 ohne zusätzliches Bypassventil 6bv.
• 4. Der Kennfeldthermostat weist im Gegensatz zum Kühlerthermostaten 6 in 11 zwei Ventilteller im Kühlerzweig auf und damit einen etwas geringeren Druckverlust. Er ist bereits deshalb teurer zuzüglich der Kosten für das beheizbare Dehnstoffelement einschließlich Ansteuerung. Der Kennfeldthermostat schließt bei geöffnetem Kühlerzweig 6a den Bypasszweig 6b ebenso wie der Kühlerthermostat 6 in 11.
• 5. Die Heizung ist im Gegensatz zu 11 mit Standardkomponenten auf hohen Kühlmitteldurchfluss ausgelegt und hat eine luftseitige Regelung ohne zusätzliches wasserseitiges Abschaltventil 2.
• 6. Der gesamte Motorkühlkreislauf ist auf geringen Druckverlust ausgelegt, um eine el. Wasserpumpe überhaupt leistungsmäßig realisierbar zu machen und weist insbesondere größere Kühlmittelquerschnitte auf als der Kreislauf gemäß 11.

If one counts the number of additional thermostatically and el. Actuated valves in 5 - 12 It is almost inevitable that the question arises as to whether this high number of additional valves can really be realized or put into practice in view of the current cost pressure in the motor vehicle industry. Against this background, a comparative cost / benefit analysis with a recently launched large-volume passenger car with an elec- trated engine coolant pump as a guide is very useful. This is here without claim to completeness and specification of accurate component prices exemplary in comparison with the application according to 11 respectively. Here are some particularly striking differences:

• 1. The mentioned series application has in particular an el. Coolant pump, instead of a belt-driven coolant pump 7 on.
• 2. An el. Heated map thermostat is used instead of the conventional thermostat 6 ,
• 3. The map thermostat sits like the radiator thermostat 6 in 11 between radiator outlet and engine inlet and has a bypass branch 6b but unlike 11 without additional bypass valve 6bv ,
• 4. The map thermostat has in contrast to the radiator thermostat 6 in 11 two valve plates in the cooler branch and thus a slightly lower pressure loss. It is therefore already more expensive plus the cost of the heated expansion element including control. The map thermostat closes when the radiator branch is open 6a the bypass branch 6b as well as the radiator thermostat 6 in 11 ,
• 5. The heating is contrary to 11 with standard components designed for high coolant flow and has air-side control without additional water-side shut-off valve 2 ,
• 6. The entire engine cooling circuit is designed for low pressure loss to a el. Water make pump ever realizable in terms of performance and in particular has larger coolant cross-sections than the circuit according to 11 ,

• • el. Bypassventil 6bv,
• • das Abschaltventil 2 und den Hochleistungswärmetauscher 4 im Heizungszweig 4a,
• • den Zusatzzweig 6cv mit el. Ventil 6cv und
• • die beiden Thermostatventile 6dv und 6ev, bevorzugt als preiswerte Bi-Metall-Bauteile ausgeführt,

addiert, so resultiert nur ein Bruchteil der Mehrkosten, die bereits die el. Kühlmittelpumpe und der el. Kennfeldthermostat beim angesprochenen Serienfahrzeug erzeugen.Be - compared to a cheap standard cooling system - the additional costs of the procedure according to the invention according 11 by the

• • el. Bypass valve 6bv .
• • the shut-off valve 2 and the high performance heat exchanger 4 in the heating branch 4a .
• • the additional branch 6cv with el. valve 6cv and
• • the two thermostatic valves 6dv and 6EV , preferably designed as inexpensive bi-metal components,

added, resulting in only a fraction of the additional costs that already produce the el. coolant pump and the el. map thermostat in the addressed series vehicle.

The fuel saving potential in the legal exhaust gas test, ie without heating in the embodiment according to 11 rather better than worse.

This is partly due to the fact that the el. Water pump can be switched off in almost the entire ECE part of the MVEURO cycle, but in the switched-off state leakage losses due to natural convection in the cooling circuit or thermosiphon effect still occur. In the system according to the invention here is due to the closing of the valves 6bv . 6cev . 6dv and 6EV There is already some advantage in the first few minutes of the cycle.

Far more important, however, is the fact that it is very important in the MVEURO for optimal use of available heat, at least after some time, the heat transfer in the engine oil cooler 30 and transmission oil cooler 40 to transfer heat from the coolant to the respective oil. As soon as the el. Water pump in the MVEURO becomes active, this means that the heating branch and the bypass branch 6b is flowed through, although this would actually not be necessary. It follows that the associated heat losses in the subsequent part of the cycle have a negative effect on fuel consumption at least until a significant excess heat has to be dissipated on the vehicle radiator. The heating of the oil, which has not yet been completed at this point in time, ensures that the disadvantages often persist even when heat has long been dissipated on the vehicle radiator.

In addition, with the el. Coolant pump due to the rel. poor efficiency chain must be saved as much as possible to pump drive power, not to be in the overall cycle already at the pump drive power much less favorable than with the conventional belt-driven pump in 11 ,

Both effects lead to a tribologically optimal utilization of the oil cooler 30 and 40 in the el. coolant pump is only partially feasible.

Furthermore, it should be noted in this context that in the known application with el. Coolant pump is not made of the particularly advantageous possibility use, this analogous to 11 To integrate, so that even at low total flows through the engine, a relatively high coolant flow through the engine oil cooler 30 or also the transmission oil cooler 40 results. This results in the system according to 11 even with very small coolant flow rates through the engine a very good heat transfer in the heat exchangers 30 and 40 , Small coolant flow rates are again just the method of choice to save fuel in the heating phase and with only a slight excess of engine heat, on the reduction of the water-side heat transfer coefficient ultimately.

With the decoupling according to the invention between the actual engine cooling requirement and the heat transfer in the oil circuits as well as the maximization of the oil temperatures is the duration, up to the cooling circuit 6a Heat must be dissipated, maximized, ie the bypass 6bv eg remains completely closed over large areas of the MVEURO. On the one hand for this reason, on the other hand because in the embodiment according to 11 about a relatively simple clocking of the bypass valve 6bv a well-dosed heat dissipation on the vehicle radiator 8th Without large fluctuations in the engine coolant temperature is possible, in particular no el. Heated thermostat is necessary to adjust the desired depending on the engine load temperature levels within the engine. The cost analysis would even with el. Heated thermostat as redundant protection still in favor of the embodiment according to 11 fail. This alleged improvement would not even be safer: This is because when using an expansion element in connection with, for example, 85 ° C opening temperature without el. Heating a much higher cooling effect and lowering the engine component temperature is possible than via the detour of heating a Dehnstoffelements with for example, 110 ° C opening temperature. The advantages that are relevant here include the spontaneous increase in the heat transfer coefficient with increased throughput by the engine and due to the high heating rate of the 85 ° C expansion element at An flow with 110 ° C hot cooling water have been described. In particular, there is also no danger of internal overheating of the expansion element in the case of unsuitable pairings of electric current and coolant-side heat transfer, combined with certain risks for the thermostatic life and partially observed overshoots during cooling of the motor.

With regard to the real-word operation, the system with el. Coolant pump claims to itself because of the possibility to maximize the coolant throughput through the heater core with high el. Pump performance to provide a particularly good heating performance. However, in view of the detailed interactions of the method according to the invention, in particular the advantages in terms of heat losses and the heat-active masses to be heated, it should be apparent that the embodiment according to FIG 11 with high performance heat exchanger and much lower coolant throughput in terms of fast cabin heating, this is by far the superior system. Experimental studies confirm this as well. It should also be clear that the increased drive power of the el. Coolant pump has a direct negative effect on fuel consumption, not to mention that the high coolant throughput by the engine also results in an increase in engine friction and thus an additional disadvantage in fuel consumption ,

Yet However, it seems more important that the system already in driving situations with limited cabin heating, both without air conditioning and in Air conditioning for the temperature of the supercooled Air, always a larger heat-active Must heat mass. The disadvantages are not only in the thermally active Mass of the heating circuit, but u.a. also in the bypass branch of the self with low cabin heat extraction with a multiple volume flow the volume flow in the heating branch is forced through, so that even relatively small volume flows in the heating branch a high Make the total volume flow through the engine unavoidable. This works not only about the loss at engine component and oil temperature disadvantageous on the fuel economy, but also about the drive power of the el. pump with its relatively poor efficiency chain.

In addition, the mentioned system with el. Engine coolant pump in particular also does not have the necessary degrees of freedom to the two oil cooler 30 and 40 to use optimally and especially at low engine load in teilerwärmten as in the heated operating condition of the engine to realize a small coolant flow rate through the engine and the heating circuit with good efficiency of the two oil cooler. In real driving result from these properties significant fuel consumption disadvantages compared to the much cheaper system according to 11 ,

The considerable cost advantages remain largely even if the specifications for a specific vehicle residual heat, ie heating even when the engine is stopped, or a follow-up cooling, ie circulation of the coolant after switching off the engine, provides. Even a very small booster pump with less than 10W el. Power can provide this function, so that the costs of such a pump are limited. In addition, it is very efficiently possible in conjunction with the throttling according to the invention to reduced heating volume flow, the functionality of the heating valve 2 represented by a variable speed positive displacement pump, in particular a gear pump, so that the valve 2 can be omitted. Alternatively, however, it is also possible to use a low-cost impeller pump that has already proven itself millions of times over. Again, it is particularly advantageous, the switchability of the valve 2 via the el. Pump represent. In the simplest case, this is done via a speed control of the impeller pump in conjunction with a thermostatic valve 2 combined with a reduced leakage, which is arranged in the heating return. Alternatively, however, a spring-loaded valve 2 be used at any point in the heating branch, but this is preferably integrated directly into the impeller pump.

In particular, it is quite possible depending on the application, starting 11 to make cost-cutting simplifications, while still avoiding some of the benefits that the system can not deliver with the el. pump, still provide fuel economy benefits to both the customer and the MVEURO. Potential ways to do this have already been described in detail, so that only one example should suffice below.

So the waiver means the use of a high performance heat exchanger 4 in 11 Although certain losses in the real-world fuel consumption and the maximum cabin heating effect, but still remains the system here better than the comparison system with el. coolant pump. In MVEURO, the benefits are fully preserved and even extend to a degree of freedom, so that in 11 is enough, the bypass valve 6cv form as a simple thermostatic valve. The heating valve 2 is then opened in MVEURO only when the thermostatic valve 6cv has opened.

The subsequent timing of the valve 2 can then choose the desired dosage of the total Make coolant throughput through the engine in teilerwärmten state and also in heat dissipation with simultaneous opening of the bypass valve 6bv and the heating valve 2 Make sure that sufficient dosing accuracy of the heat supply is available.

If the design focus is exclusively on the MVEURO, then in this constellation may even even the thermostatic valve 6dv in the oil cooler branch 6d omitted. The engine oil cooler 40 will then coincide with the activation of the additional bypass branch 6c flows through, which may well be fuel efficient depending on the engine, especially since here the total coolant flow through the engine remains small due to the first still closed heating valve. For cabin heating requirements, omitting the oil cooler valve means 6dv At high cabin heating demand now a disadvantage, since due to the standard heat exchanger must be worked here with high coolant flow and the oil cooler 30 without the valve 6dv the effective heat-active mass increases. For small to medium Kabinenheizbedarf the return temperature of the coolant on the inventive reduction of the coolant flow in the heating branch 4a but also be lowered with a standard heat exchanger so far that the oil cooler 30 no heat is transferred, ie the elimination of the valve 6dv can be compensated. With the additional use of a high-performance heat exchanger, not only the scope for this measure extends to the maximum heating demand, but it can even be actively transferred heat from the engine oil into the coolant. It has already been described in detail that in the sum of these measures, a dramatic improvement in cabin heating can be achieved. As measurements show, this goes all the way to eliminating the extra heaters in diesel cars.

The parent application as the present application are highly geared to the implementation of high temperatures in the engine according to the invention while minimizing the temperatures outside the engine and the switching between the individual areas with respective focus on fuel consumption minimization, heating power maximization and engine power maximization or overheating protection with a conventional and very inexpensive radiator thermostats 6 implement.

The physical principles described for minimizing heat losses and for minimizing fluctuations in the engine component temperature with limited dosing accuracy and reaction rate of the radiator thermostat 6 and the bypass valve 6bv can also be used in systems with the engine control 16 freely controllable replacement valve 6 instead of the conventional radiator thermostat 6 implement. In particular, the interactions with respect to the control quality make it possible in particular to work with components of a much coarser mesh size than was hitherto necessary. An application example is here, for example, the well-known rotary valve whose serial introduction has failed so far not least to the cost of high positioning accuracy and the difficult vote.

Some weaknesses of the known el. Heated map thermostat considered on its own have already been discussed. The fact that an additional el. Heatability may also lead to a deterioration of the control properties and possibly also the operational safety has been described. In addition to the slower switching to reduced engine component temperature, this particular has fail-safe disadvantages. Since only the upper control temperature is available in the event of a failure of the el. Current supply, the failure is more critical than, for example, with a bypass valve 6bv with solenoid valve, which with the setting "normally open" in the event of a failure eg the electric line is unproblematic in terms of engine performance and operational safety.

However, there are also applications where at least one very rapidly opening electr. Heated thermostat, ie a design with high el. Heating power, can be brought into harmony with the inventive concept to a large extent. In this case, the individual measures according to the invention for damping potential overshoots when opening the cooler branch at very high el. Current supply do not give rise to underestimated advantages. In this regard, it is important that switching to high coolant flow in the bypass branch 6b with the el. bypass valve 6bv can be done very quickly and in particular already on detection of an increased engine load from the engine control. The fact that the nearly dead time-free increase of the coolant flow through the bypass branch 6b And thus also by the engine at the same time causes a jump in the cooling of the engine components, long before the el. energization of the radiator thermostat can be effective, also offers an extension of the potential use. In contrast to cost reasons and in terms of fastest possible switching ia cheaper variant with unheated standard radiator thermostats with, for example, 85 ° C opening temperature, here provides the temperature difference between the Thermostatnenntemperatur and the coolant temperature at the engine outlet not the relevant contribution to the rapid response of the expansion element. Rather, this must be done via a correspondingly high el. Performance of the heating and / or thermal insulation of the expansion element. The tuning of these parameters and in particular the required el. Power is relatively complex in the relatively wide range of flow and temperature conditions in the bypass, radiator and heating branch, so that it can quite come to overshoots when opening, which are quite fundamentally undesirable, especially at low heat and small However, coolant flow through the engine should be avoided. The damping effect of the additional branches according to the invention is very helpful here.

By contrast, if this problem can be overcome by suitable components and if the possibility of an ultrafast switching to lowered component temperatures is not the decisive design criterion, the use of the el. Heated thermostat is certainly attractive in some applications. In particular, the raised control temperature without el. Current provides the advantage that the heat dissipation takes place at the radiator at a higher coolant temperature and thus there is more leeway to lower the coolant flow rate through the engine. With el. Teilbestromung here the margin can be additionally shifted in the direction of slightly higher engine heat surplus. This is in particular often a slightly gentler transition between phases with and without opening the bypass valve 6bv achievable. Another important advantage may be here in particular that the individual branches now in principle in the vicinity of the radiator thermostat 6 can lead. Ie it can be especially for the branches 6c . 6d . 6e and the heating return of the connection, already provided as a heating return, to the radiator thermostat is used instead of an additional connection branch downstream of the radiator thermostat. This becomes possible because there is no longer the risk that the warm coolant will open the radiator thermostat.

The requirements of the heating branch with respect to a return temperature below the thermostatic opening temperature are thus less critical, so that in particular still closed radiator thermostats 6 Also, the heating branch by means of an el. Valve can intervene more in the metering of the engine coolant flow rate.

In order to minimize the heat-active mass but also to improve damping effect, it is generally better, the lines 6c . 6d and 6e at positions 7e downstream of the radiator thermostat 6 to arrange and position the invention largely cooled at many operating points heating return further upstream, especially at today's standard position on the radiator thermostat 6 ,

Finally, it should be noted that the inventive concept both in the particular for cost optimization to be preferred variant without el. Heated thermostat 6 is very efficient to use as well as with el. driven thermostat 6 and that this thought goes even in applications where an el. coolant pump is the belt-driven engine coolant pump 6 Replaces fuel economy benefits yet.

It is a definite advantage that the local lowering of the coolant temperatures in the heating branch 4a but also in the rest of the coolant system and especially the very spontaneous response of the cooling when opening the additional valves help to eliminate reservations regarding the conventional el. Thermostats. Especially with designed for high driving dynamics car is partially dispensed against the background of too slow response to the use of el. Heated thermostat, although this represents a simple and proven method for fuel economy. Both in the procedure according to the invention without el. Heated thermostat and with el. Heating are here significantly more favorable response times of the cooling can be found.

The cool reserve is in the procedure without el. heated thermostat i.a. higher than with el. Heated thermostat, so here i.a. little cooling potential must be held, but if necessary, the measures described below also be used here accordingly.

When using the invention with el. Heated thermostat, it is particularly advantageous for very high demands on the cooling dynamics, if at engine part load, at least from a minimum temperature of the coolant or engine components, at least one of the engine control 16 controllable additional valve in a leading through the engine coolant branch, in particular a bypass valve 6bv in the bypass branch 6b and / or an additional valve 6cv in a branch 6c without heat exchanger and / or an additional valve 6dv in a branch 6d with engine oil cooler 30 and / or an additional valve in a branch 6e with a transmission oil cooler 40 , and / or a valve 2 in the heating branch 4a , partially or completely closed to provide a cooling reserve and in case of a sudden transition to very high engine load from the engine control 16 is opened. As a result, regardless of the local coolant temperatures, there is always a potential for increasing the cooling effect via the increase in the coolant flow.

It depends on the basic function of the valves, whether they remain open after the transition to high cooling capacity, such as the bypass valve 6bv or closed, such as valves 6cv without heating heat exchanger or cooling criti components.

Conversely, the oil cooler valves 6dv and 6EV In general, it is often already largely open during partial load, so that the latitude to use complete opening as a cooling reserve during the transition to high load is, of course, limited. Nevertheless, it is advantageous that these optionally starting from the partially opened state with warm or teilerwärmten engine in the partial load, completely open and remain open to protect the oil from overheating.

Claims (46)

A method for operating a heating and air conditioning unit in motor vehicles with air-side temperature control, with a heating heat exchanger, which extracts a heat transfer medium, in particular the coolant of the prime mover, heat and delivers to the conveyed by means of a heater fan through the heater core cabin air, characterized in that the cooling water flow rate in Heating branch is temporarily throttled by means of a throttle device so in the direction of reduced heating potential that a minimum heating criterion that characterizes the required minimum heating potential, by means of the associated adjustment of the air-side temperature control is still met. Method according to claim 1, characterized in that that as a minimum heating criterion a map is stored, which ensures that the coolant flow rate in the heating branch decreases with decreasing heat removal at the heating heat exchanger and in particular, that the coolant outlet temperature of the heating heat exchanger despite low heat extraction preferably is lowered far in the direction of ambient temperature. Method according to one of claims 1-2, characterized that an additional Map characterizes the area in which a reduction the coolant flow rate an improvement in cab heating results and that in an oversupply heating potential an additional reduction the coolant flow rate below the throughput value of the maximum heating power. Method according to one of claims 1-3, characterized that the minimum heating criterion for multi-zone air conditioners is a first Map area for nearly uniform heat extraction for the has individual zones and additional Map areas for uneven heat extraction for the individual zones. Method according to claim 4, characterized in that that the coolant flow in the heating branch with uneven heat extraction is higher as with even heat extraction. Method according to one of claims 1-3, characterized that in multi-zone air conditioners zone-dependent minimum heating criteria by means of separate throttle devices for the cooling water throughputs the individual zones of the heating heat exchanger are complied with, so that in addition to the fulfillment the local heating power requirements as far as possible lowering the temperature at the heating return he follows. Device for operating a heating and air conditioning unit in motor vehicles with air-side temperature control, in particular heating and air conditioning unit for motor vehicles according to one of the claims 1-6, with a heating heat exchanger, which a heat transfer medium, in particular the coolant the prime mover, heat withdraws and to the means of a heating fan through the heating heat exchanger funded Cabin air emits, characterized in that the cooling water flow rate in the heating branch by means of a throttle device temporarily such in the direction of reduced heating potential is throttled that a Minimum heating criterion, which is the required minimum heating potential characterized by the associated adjustment of the air side Temperature control after fulfillable is. Device according to claim 7, characterized in that that the throttling of the coolant flow rate in the heating branch under consideration the minimum heating criterion with one or more over the engine control or the air-conditioning control unit controlled cooling water valve (s) he follows. Device according to claim 7, characterized in that that is the throttling of the coolant flow rate in the heating branch under consideration the minimum heating criterion with one or more thermostatic valves in the cold cooling water zones of the heating heat exchanger or the heating return takes place, which (s) when exceeded a cooling water temperature limit throttles the throughput. Device according to claim 9, characterized in that that a high performance heat exchanger is used and the thermostat control range is chosen so that in conjunction with the heating performance of the high performance heat exchanger the maximum heat output with high water-side temperature drop is ensured. Device according to one of claims 9-10, characterized in that depending on the heat 25 ° C at very high power potential up to approx. 35 ° C with slightly lower power potential. Device according to one of claims 1-11, characterized that the coolant flow in the heating branch temporarily also one of the determining coolant flows the internal combustion engine is. Device according to one of claims 1-12, characterized that high performance heat exchanger be used and the reduction of the cooling water flow in one first mode only to improve fuel economy is used and in a second mode primarily for maximization the cabin heating effect. Device according to one of claims 1-13, characterized in that a high-performance heat exchanger 4 is used and the inner diameter of the feed line is less than 70% of the inner diameter of the return line. Device according to one of claims 1-14, characterized in that a high-performance heat exchanger is used, an el. Valve in the heating branch 4a if necessary, the shutdown of the coolant flow takes over and that when the el. Valve in the heating branch, a thermostatic valve makes the throttling to low return temperature. Method and device for operating a cooling and heating circuit, in particular method and device with design features according to one of claims 1-15 for motor vehicles with an internal combustion engine, by means of an engine coolant pump 7 circulated coolant is cooled, with a self-sufficient thermostatic valve 6 , which for controlling the coolant temperature, the coolant flow rate through the internal combustion engine 1 and the vehicle radiator 8th regulates and a bypass branch 6b , which additionally varies the coolant flow rate through the internal combustion engine as a function of its cooling requirement, in particular method for operating internal combustion engines with a conventional expansion thermostat with the electronic engine control 16 influenceable additional valve 6bv , characterized in that the heating heat exchanger circuit 4a and / or others even when the thermostatic valve is closed 6 flow through coolant branches such downstream of the thermostatic valve 6 integrated into the cooling system are that the thermostatic valve 6 by closing the additional valve 6bv in the bypass branch 6b undergoes such a low heat input that this remains closed well beyond the thermostat nominal temperature, and that the thermostatic valve 6 by opening the additional valve 6bv due to the flow through the coolant flow in the bypass branch 6b near its nominal temperature works by switching the coolant flow in the radiator branch 6a governs accordingly. A method according to claim 16, characterized in that the additional valve 6bv is used to the coolant flow rate through the internal combustion engine 1 temporarily, especially during engine warm-up and partial load, to be greatly reduced or completely prevented. Method according to one of claims 1-17, characterized in that the reduction / inhibition of the coolant flow rate through the internal combustion engine 1 through the additional valve 6bv alone and not exclusively from the engine control 16 modifiable coolant flow paths at points 7e downstream of the thermostatic valve 6 and upstream of the engine coolant pump 7 are integrated in the cooling system. Method according to one of claims 16-17, characterized in that the reduction / inhibition of the coolant flow rate through the internal combustion engine 1 through the additional valve 6bv in conjunction with additional intervention by the engine control 16 takes place, in particular with other coolant valves or by means of other flow restricting organs in the heating branch 4a and / or coolant flow paths at points 7e downstream of the thermostatic valve 6 and upstream of the engine coolant pump 7 are integrated in the cooling system. Device according to one of claims 1-19 and in particular according to one of the methods or one of the devices of the original application DE 10 2004 058 869.4 , characterized in that in addition to the actual Zusatzbybassventil 6bv in the bypass branch 6b at least one additional bypass branch, in particular an additional bypass branch 6c without the involvement of a heat exchanger and / or further Zusatzbypasszweige with heat exchangers or cooled components, in particular an additional branch 6d with engine oil cooler 30 and / or an additional branch 6e with transmission oil cooler 40 , and / or a heating branch 4a , Are involved in the engine cooling circuit that the respective coolant return to the engine 1 in a separate or common position 7e takes place, the downstream of the autarkic radiator thermostat 6 is located and upstream of the engine coolant pump 7 , Apparatus according to claim 20, characterized in that the flow through the Zusatzbypasszweige in total at least temporarily on egg NEN lower coolant flow rate through the internal combustion engine 1 leads, as this without flow through the Zusatzbypasszweige, both with open bypass branch 6b and closed radiator branch 6a as well as from the thermostat 6 partially or completely closed bypass branch 6b and thus partially or completely open cooler branch 6a , the case is. Device according to one of claims 20-21, characterized in that the Zusatzbypasszweig only a channel or a line of small cross-section 6c is and permanently for a heat transfer of particularly warm places of the internal combustion engine 1 to the position 7e ensures, and in particular, that this line has an inner diameter smaller 6 mm and / or a passive and not thermostatic throttle body, in particular in the form of a pinhole with a diameter smaller 6 mm, has. Device according to one of claims 20-21, characterized in that the Zusatzbypasszweig only a channel or a line of small cross-section 6c is and by means of one of the engine control 16 controlled valve 6cv or by means of a self-sufficient thermostatic valve 6cv temporarily for increased heat transfer of particularly hot spots of the internal combustion engine 1 to the position 7e ensures, and in particular, that the line 6c an inner diameter smaller 6 mm. Device according to one of claims 20-23, characterized in that the additional bypass branch 6c an additional branch 6d with engine oil cooler 30 and / or an additional branch 6e with a transmission oil cooler 40 by means of a valve 6cv temporarily or permanently charged with warm coolant. Apparatus according to claim 24, characterized in that at least one additional branch, in particular an additional branch 6d with engine oil cooler 30 and / or an additional branch 6e with a transmission oil cooler 40 , the cooling water at a still little heated position downstream of the coolant pump 7 , in particular at the pump outlet or at the engine inlet, remove, so that their flow allows the heat exchange with the coolant, without increasing the total coolant flow through the engine and thus to lead to an undesirable lowering of the engine components. Device according to one of claims 20-22 or 24, characterized in that at least one additional bypass branch, in particular a Zusatzbypasszweig 6d with engine oil cooler 30 and / or an additional bypass branch 6e with a transmission oil cooler 40 , the cooling water in a particularly warm position of the internal combustion engine, in particular at the engine outlet, takes and is reduced so far in the flow, that at high cooling demand of the engine and open auxiliary bypass valve 6bv the coolant flow through the bypass branch 6b and the radiator branch 6a in total is much higher than the sum of the throughputs through the bypass branches, in particular through the bypass branches 6c . 6d and 6e and the open heating branch 4a , Device according to one of claims 20-26, characterized in that at least one valve, in particular an additional valve 6cv in the bypass branch 6c and / or a valve 2 in the heating branch 4a and / or a valve 6dv in the engine oil cooler branch 6d and / or a valve 6EV in the transmission oil cooler branch 6e , with additional bypass valve closed 6bv a switchover between three types of operating modes, with first operating modes with fuel consumption-oriented flow conditions of the cooling system taking into account a target value of the cabin heat, second comfort and heating power oriented modes to maximize the heating effect and third modes with provision of maximum component temperatures without the risk of local component overheating. Device according to one of claims 20-27, characterized in that at least 1 a valve, in particular an additional valve 6cv in the bypass branch 6c and / or a valve 2 in the heating branch 4a and / or a valve 6dv in the engine oil cooler branch 6d and / or a valve 6EV in the transmission oil cooler branch 6e , with open additional bypass valve 6bv a switchover between two other types of operating modes makes, firstly fuel consumption-oriented modes with flow conditions of the cooling system taking into account a target value of the cabin heating and second modes with providing high cooling capacity with lowered component temperatures without the risk of local component overheating up to the highest load and power of the engine 1 , Device according to one of claims 20-28, characterized in that of the engine control 16 controllable valves, in particular the valve 6cv in the additional bypass branch 6c and depending on the arrangement, the valves 6dv and or 6EV and or 2 in the engine oil cooler, Getriebeölkühler- and heating branch, in the lower to middle engine part load in both warm-up and excess engine heat make a throttling of the total coolant mass flow through the engine, fully open at higher engine load and to simplify the temperature control even with partial and complete opening of the bypass valve 6bv remain open and that they are closed only at very high cooling demand. Device according to one of claims 1-20 or 25, characterized in that the heating return at an arbitrary position downstream of the radiator thermostat 6 flows and that over an open bypass branch, which at a position 7e behind the radiator thermostat 6 and in front of the coolant pump 7 opens, in particular a permanently open bypass branch 6c without bypass valve 6cv , with any coolant flow and any heat output at the heating heat exchanger 4 An undercooling of the coolant at the engine inlet is just as safe as a premature opening of the radiator thermostat 6 , Device according to one of claims 1-20 or 25, characterized in that the heating return at a position on or upstream of the radiator thermostat 6 that flows through an open bypass branch, which at one position 7e behind the radiator thermostat 6 and in front of the coolant pump 7 opens, in particular a permanently open bypass branch 6c without bypass valve 6cv , with any coolant flow and any heat output at the heating heat exchanger 4 a cooling of the coolant at the engine inlet is reliably avoided and that a design for a low base coolant throughput, and / or throttling and / or switching off the coolant flow in the heating branch premature opening of the radiator thermostat 6 prevented. Apparatus according to claim 31, characterized in that in operating situations with excess heat of the internal combustion engine, the heat dissipation via the vehicle radiator 8th in a first step takes place in that the coolant flow is increased in the heating branch so far that the return temperature in the heating branch on the radiator thermostat 6 above the thermostat opening temperature and an accurate and simple dosage of heat dissipation at the radiator using the self-regulating properties of the radiator thermostat 6 brought about and that in a second operating mode with very high cooling demand, the bypass valve 6bv opens. Device according to one of claims 1-32, characterized in that in addition to the bypass controlled by the engine control 6b with bypass valve 6bv a second bypass branch controlled by the engine control, which starts at a particularly hot spot of the engine cooling system and at the position 7e opens, in particular a Zusatzbypasszweig 6c with by the engine control controlled bypass valve 6cv , via the regulation of the coolant flow rate ensures that in operating situations with sufficient cabin heat only a small temperature difference between the coolant inlet and outlet of the internal combustion engine 1 is present and in operating situations with insufficient cabin heating a large temperature difference. Device according to one of claims 1-32, characterized in that in addition to the bypass controlled by the engine control 6b with bypass valve 6bv one from a self-contained differential temperature valve 6cv controlled Zusatzbypasszweig, which starts at a particularly warm point of the engine cooling system and at the generally colder position 7e opens and the mixing temperature 6t2 behind the position 7e and the flow temperature 6t1 uses as a reference variable and regulates the additional bypass flow rate so that waiving the maximum possible cabin heating in all operating situations, a small temperature difference between coolant inlet and outlet of the internal combustion engine 1 is applied. Device according to one of claims 1-34, characterized in that an engine oil cooler 30 and / or a transmission oil cooler 40 at least in vehicles with cabin heat deficit a thermostatic or by the engine control 16 has controlled flow control, which prevents their flow to a minimum temperature of the coolant. Device according to one of claims 1-33, characterized in that at Kabinenheizleistungsdefizit the heating branch 4a at least partially open, all bypass branches are largely closed and that an additional branch 6d with engine oil cooler 30 the coolant at a still little heated position downstream of the coolant pump 7 , in particular at the pump outlet or at the engine inlet, removes and at the position 7e fed back so that heat is transferred from the engine oil to the cooled at the heating heat exchanger below the engine oil temperature coolant without abandoning the heat-promoting temperature stratification between inlet and outlet of the engine. Device according to one of claims 1-36, characterized in that the additional coolant bypass valve 6bv a self-sufficient valve is, which is controlled by a pressure difference of the coolant pressure to the ambient pressure and that at least one of the engine control 16 controlled valve, in particular a valve 6cv in the additional branch 6c and / or a valve 6dv in the engine oil cooler branch 6d and / or a valve 6e in the transmission oil cooler branch 6e and / or a heating valve 2 in the heating branch 4a , the fine control until self-sufficient opening of the additional coolant bypass valve 6bv assumes, which occurs when high cooling demand and especially depending on the design and position of the pressure tapping point, even at high engine speed as cavitation protection of the engine coolant pump 7 self-sufficient opens. Device according to one of claims 1-36, characterized in that the additional coolant bypass valve 6bv This is replaced by a non-self-sufficient, by the engine control 16 Radiator replacement set to be set 6 coarse-mesh adjustment accuracy, in particular a rotary valve, the engine temperature level for the beginning of heat dissipation on the vehicle radiator 8th defined and engine-internal coolant branches, in particular coolant branches 6c without heat exchanger and / or 6d with engine oil cooler and / or 6e with transmission oil cooler 40 not by the radiator thermostat set 6 lead and thereby the principle and component-related control fluctuations of the radiator coil replacement 6 dampen away so that they do not adversely affect the internal combustion engine, and in particular that this control valves 6cv and or 6dv and or 6EV in the coolant branches 6c - 6e be used. Device according to one of claims 1-36, characterized in that in addition to the additional coolant bypass valve 6bv a not self-sufficient, from the engine control 16 in the control temperature level influenceable radiator thermostat 6 with a high response speed and in particular coarse adjustment accuracy, in particular an el. Heated radiator thermostat 6 , the engine temperature level for the start of heat dissipation on the vehicle radiator 8th defined and engine-internal coolant branches, in particular coolant branches 6c without heat exchanger and / or 6d with engine oil cooler 30 and or 6e with transmission oil cooler 40 not through the radiator thermostat 6 lead and thereby the principle and component-related control fluctuations of the fast responding radiator thermostat 6 dampen away so that they do not adversely affect the internal combustion engine, and in particular that this control valves 6cv and or 6dv and or 6EV in the coolant branches 6c - 6e be used. Method and apparatus for operating a cooling and heating system of internal combustion engines with one of the engine control 16 controlled thermostats 6 , in particular an el. heated expansion thermostat 6 , with radiator branch 6a , Bypass branch 6b and further coolant branches, in particular method and device with design features according to one of claims 1-15, for motor vehicles with an internal combustion engine, characterized in that one also from the engine control 16 controlled additional valve 6bv the bypass branch 6b temporarily closes. Method and device according to claim 40 with the motor control 16 controlled el. heated expander thermostat 6 and also from the engine control 16 controlled additional valve 6bv in the bypass branch 6b , characterized in that the el. Heated thermostat 6 by closing the additional valve 6bv in the bypass branch 6b undergoes a reduced heat input and thus takes place without el. energization heat removal at the cooler at elevated temperature level of the engine and reduced total coolant flow rate through the engine and that with el. energizing the el. heated radiator thermostat 6 with simultaneous opening of the additional bypass valve 6bv through a high coolant-side heat supply to the el. heated radiator thermostat 6 and the spontaneous increase of the heat transfer coefficient within the internal combustion engine with a sudden increase in total coolant throughput spontaneous engine component cooling takes place. A method and apparatus according to claim 41, characterized in that the heat dissipation on the vehicle radiator 8th with closed bypass valve 6bv and thus reduced total coolant throughput by the internal combustion engine by el. Partial flow of the el. Heated thermostat, so that in particular with very low heat surplus of the internal combustion engine can still be operated with reduced total coolant flow. Device according to one of claims 38-42, characterized in that the heating return upstream of the connection point (s) 7e the coolant branches 6c - 6e lies and in particular directly on the radiator thermostat 6 is arranged. Method and device for map cooling of internal combustion engines with one of the engine control 16 controlled el. heated radiator thermostats 6 , In particular method or device according to one of claims 1-15 or 38-43, characterized in that at engine part load, at least from a minimum temperature of the coolant or the engine components, at least one of the engine control 16 controllable additional valve in a leading through the engine coolant branch, in particular a bypass valve 6bv in the bypass branch 6b and / or an additional valve 6cv in a branch 6c without heat exchanger and / or an additional valve 6dv in a branch 6d with engine oil cooler 30 and / or an additional valve in a branch 6e with a transmission oil cooler 40 , and / or a valve 2 in the heating branch 4a , partially or completely closed to provide a cooling reserve and in case of a sudden transition to very high engine load from the engine control 16 is opened. Method and device according to claim 44, characterized in that the valve 6cv and / or when operating without Heizleistungsentnahme the valve 2 is closed again at high load after the radiator thermostat 6 has largely opened. Method and device according to claim 44, characterized in that the valves 6dv and 6EV in case of sustained high load, starting from partially open condition with partial or warm engine in partial load, to be fully opened and remain open after the radiator thermostat 6 has largely opened.