SE1050162A1 - Arrangements to prevent ice formation in a charge air cooler - Google Patents

Abstract

The present invention relates to an arrangement for preventing ice formation in a single-charge air cooler comprising a radiator portion (3) where compressed air is cooled by ambient air flowing through the radiator portion (3). The arrangement comprises a first fate element (7a) which in a closed position is adapted to prevent compressed air being led through an area (A) of the radiator portion (3), a second fate element (7a) which in a closed position is adapted to prevent compressed air passage through a second region (B) of the radiator portion (3) which is larger than the first region of the radiator portion (A), and a control unit (10) adapted to receive information regarding at least one parameter (11, 12, 14) related to the risk of icing in the charge air cooler and in cases where the said parameter indicates that there is a risk of ice formation in the charge air cooler, the control unit (10) is adapted to set one of the fate elements (7a, 7b) in a closed position so that the compressed air is led through a reduced area (RA, RB) of the radiator section (3). (Fig. 1)

Description

“IO to the internal combustion engine becomes defective or ceases altogether as a result of the internal combustion engine stopping.

SUMMARY OF THE INVENTION The object of the present invention is to provide an arrangement which effectively prevents ice from forming in an air-cooled charge air cooler even during times when the air cooling the charge air has a very low temperature.

This object is achieved with the arrangement of the kind mentioned in the introduction, which is characterized by the features stated in the characterizing part of the patent claim 1. When there is a risk of ice formation in the charge air cooler, one of the fate elements is placed in a closed position so that the compressed air is led through a reduced area of the radiator section. Because the compressed air is led through a reduced area of the radiator portion, it provides a higher flow rate than if it is passed through the entire radiator portion. The compressed air thus does not have time to cool to the same low temperature in the charge air cooler as when the entire cooler section is used. At times when there is a risk of ice formation, the control unit chooses to set the fl fate element that provides the most suitable reduction of the charge air cooler capacity in the closed position. Thus, the compressed air is cooled to a low temperature in the charge air cooler but not to such a low temperature that there is a risk of ice formation in the charge air cooler.

According to an embodiment of the present invention, the larger area of the radiator portion comprises the entire smaller area of the radiator portion. In this case, the second fl element can be arranged upstream of the first ementet element. When the second ementet element is moved to the closed position, it blocks the supply of compressed air to the downstream first ementet element. In this way, two reduced areas of the cooling portion of different sizes can be provided in a simple manner.

The arrangement advantageously comprises at least a third fate element which in a closed position is adapted to prevent compressed air from being passed through a third region of the radiator portion, which third region is larger than the second region of the radiator portion.

Thus, the cooling of the compressed air can be reduced in a further step. The third destiny element is advantageously arranged upstream of the first two destiny elements.

Thus, the third area of the cooling portion will include both the first area and the second area of the cooling portion.

According to a preferred embodiment of the present invention, the arrangement comprises a sensor which is adapted to sense a parameter in the form of the temperature of the ambient air. A prerequisite for icing to take place is that the ambient air that cools the compressed air in the radiator section has a temperature below 0 ° C. It is therefore appropriate to sense this parameter to estimate whether there is a risk of ice formation. However, there is not always a risk of ice formation in the charge air cooler when the ambient air has a temperature below 0 ° C.

The control unit can therefore also be adapted to provide information regarding a parameter which is related to the load of an internal combustion engine. When an overcharged internal combustion engine is heavily loaded, a relatively large amount of compressed air with a high temperature is supplied to the charge air cooler. In this case, there is no risk of ice formation in the charge air cooler unless the ambient air has an extremely low temperature. At times when the supercharged combustion engine is low loaded, a relatively small amount of compressed air with a relatively low temperature is led to the charge air cooler. In this case, the risk is very great that ice formation occurs in the charge air cooler even at ambient air temperatures just below 0 ° C. The control unit can, with the aid of the above-mentioned parameters, estimate whether there is a risk of ice formation and, if so, set one of said fate elements in the closed position so that the compressed air is cooled in an area of the radiator portion of a suitable size.

Alternatively or in combination, the arrangement may comprise a sensor which is adapted to sense a parameter in the form of the temperature of the compressed air which is led out of the charge air cooler. If the compressed air that leaves the charge air cooler has a temperature below 0 ° C, ice formation takes place inside the charge air cooler. With the aid of this information, the control unit can assess whether there is a risk of ice formation and, if so, close one of said fate elements so that the area for cooling the compressed air is reduced in a suitable manner. If the control unit subsequently receives information indicating that the compressed air leaving the charge air cooler has a temperature clearly above 0 ° C, the control unit can again set the destiny element in an open position.

According to a preferred embodiment of the present invention, the charge air cooler comprises a tank which is adapted to receive the compressed air before or after it has been cooled in the cooler portion, said fate elements being arranged inside said tank. Most conventional charge air coolers are provided with a hot inlet tank on one side of the radiator portion to accumulate the hot compressed air before it is cooled and a cold outlet tank on the opposite side of the radiator portion to accumulate the cooled compressed air. The flow elements can obtain a protected location inside one of these tanks. The flow elements can be arranged one after the other inside, for example, such an inlet tank so that the most upstream fl element defines the area of the cooler portion which is used to cool the compressed air.

According to a preferred embodiment of the present invention, the control unit is adapted to use separate power means for setting the individual fate elements in desired positions. Such separate power means may be electric motors or other similar components such as pneumatic or hydraulic cylinders. Alternatively, the control unit may be adapted to utilize a common power member and a motion transmitting mechanism to set the individual fl fate elements in desired positions. In this case, different degrees of activation of the force means can be transmitted to movements of the fl elements so that they are in turn moved to the closed position. The motion transmitting mechanism may comprise a slidably arranged control rod and that the individual des element elements comprise contact means which are adapted to be in contact with a guide surface of the control rod. The contact surface may comprise recesses and when the contact means reaches such a recess they provide a movement which displaces the respective fl element elements from the open position to the closed position. Although the object of the invention is to eliminate ice formation in the charge air cooler, said fate element can also be used on other occasions when it is advantageous to reduce the cooling of the compressed air in the charge air cooler. One such occasion is when the exhaust gases have such a low temperature that they do not obtain a desired purification in an exhaust gas purifying component which may be a catalyst. When a vehicle is started cold or when the internal combustion engine has a low load, the exhaust gas temperature from the internal combustion engine may have a too low temperature for the catalyst. In these cases, the control unit can set one of said fate elements in the closed position so that the compressed air is led through a reduced area of the charge air cooler. Thus, the air which is led to the combustion engine can obtain a higher temperature as well as exhaust gases which thereby wind up the catalyst to a desired temperature.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, embodiments of the invention are described by way of example with reference to the accompanying drawings, in which: Fig. 1 shows a charge air cooler according to a first embodiment of the present invention and Fig. 2 shows a charge air cooler according to a second embodiment. of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Fig. 1 shows a charge air cooler which may be mounted to a front portion of a vehicle driven by a schematically shown supercharged internal combustion engine 1. An overcharged internal combustion engine of compressor 1 requires. The charge air cooler has the task of cooling the compressed air before it is led to the combustion engine l.

The cooling results in the air becoming more compact so that a larger amount of air can be supplied to the internal combustion engine. The charge air cooler comprises an inlet tank 2 which, via an inlet opening 2a, receives water compressed air from a compressor (not shown).

The charge air cooler comprises a radiator package 3 extending between the first tank 2 and an outlet tank 4 which receives the compressed air after cooling in the radiator package 3. The radiator package 3 comprises a number of tubular elements 5 extending substantially rectilinearly in a common plane 2 between the inlet tank 2 and the inlet tank. 4.

The tubular elements 5 are arranged in parallel at substantially uniform distances from each other so that regular gaps 6 are formed between adjacent tubular elements 5. Ambient air can thus flow through the gaps 6 between the tubular elements 5. The gaps 6 are provided with pleated heat transfer elements to increase the heat transfer surface between the ambient air and the tubular elements 5. The tubular elements 5 may be provided with internal elements such as turbulators to improve the cooling of the compressed air inside the tubular elements 5. The flow of ambient air through the radiator package 3 is provided by the movement of the vehicle and / or by a radiator fl genuine which sucks air through the radiator package 3. The ambient air cools the compressed air which is led through the tubular elements 5. The cooled compressed air is led out of the outlet tank 4 via an outlet opening 4a. The compressed air is optionally mixed with recirculating exhaust gases before it is led to the supercharged internal combustion engine 1.

In this case, a first fate element 7a, a second fate element 7b and a third fate element 7c are arranged inside the inlet tank 2. The flow elements 7a, 7b, 7c are arranged at different levels in the inlet tank 2. The flow elements 7a, 7b, 7c are pivotally arranged around between an open position and a closed position. A seat 8a, 8b, 8c defines the closed position of each of the fate elements 7a, 7b, 7c. The seat Sa, 8b, 8c can extend completely or partially around an inner surface of the inlet tank 2. In Fig. 1, the first fl element 7a and the third ement element 7c are in an open position while the second fl element 7b is in a closed position. The flow elements 7a, 7b, 7c have a shape so that they completely block the internal cross-sectional area of the inlet tank 2 in the closed position. When a fate element 7a, 7b, 7c is in the closed position, the compressed air provides an overpressure in the inlet tank 2 upstream of the fate elements 7a, 7b, 7c. This overpressure presses the fate element 7a, 7b, 7c against the seat Sa, 8b, 8c so that a tight connection is obtained between the fate element 7a, 7b, 7c and the seat 8a, 8b, 8c. In this case, the fate elements 7a, 7b, 7c are movably arranged between the open and the closed position by means of their respective electric motors 9a, 9b, 9c. Alternatively, the fate elements 8a, Sb, 8c may be movably arranged by means of other force means such as, for example, pneumatic or hydraulic cylinders.

When the first el element 7a is in a closed position, the compressed air is prevented from being led to a portion of the inlet tank 2 which is located downstream of the first el element 7a. This lower part of the inlet tank 2 communicates with a lower area A of the radiator package 3 which comprises a few tubular elements 5. When the first fl element 7a is in the closed position, the compressed air located upstream of the first ementet element 7a in the inlet tank 2 is led to an area RA of the radiator package 3. When the second fl element 7b is in a closed position, the compressed air is prevented from being led to a portion of the inlet tank 2 which is located downstream of the second fl element 7b. This portion of the inlet tank 2 communicates with an area B of the radiator package 3 which comprises a larger number of tubular elements 5. The compressed lug located upstream of the second destructive element 7b is led to an area RB of the radiator package 3 which comprises remaining tubular elements 5. When the third destructive element 7c is in a closed position, the compressed air to be led to a portion of the inlet tank 2 which is located downstream of the third fl desert element 7c. This portion of the inlet tank 2 communicates with an area C of the radiator portion 3 which comprises a large part of the tubular elements 5. The compressed air is in this case led from the portion of the inlet tank located upstream of the third fate element 7c to an area RC of the radiator portion 3 with only a few tubular elements 5.

A control unit 10 years adapted to receive information regarding at least one parameter that is related to the risk of ice formation in the charge air cooler. A relevant such parameter is the temperature of the ambient air that cools the compressed air in the charge air cooler. The control unit 10 is then adapted to receive information from a temperature sensor 11 regarding the temperature of the ambient air. If the ambient air has a higher temperature than 0 ° C, there is no risk of ice formation in the charge air cooler.

If, on the other hand, the ambient air has a temperature lower than 0 ° C, there is a risk of icing.

The risk of icing also depends on other parameters such as the speed of the cooling air through the charge air cooler and the temperature and fate of the compressed air.

The temperature and fate of the compressed air are related to the load of the internal combustion engine 1. The control unit 10 is here adapted to provide information 12 regarding the load of the internal combustion engine 1. The control unit 10 is also adapted to receive information from a sensor 13 which is related to the temperature of the exhaust gases when they leave the internal combustion engine 1. In order for the exhaust gases to be accepted in an acceptable manner by an exhaust gas cleaning component, such as a catalyst, the exhaust gases are not too low. temperature.

During operation of the vehicle, the control unit 10 receives information from e.g. the sensor ll about the temperature of the ambient air. If the ambient air temperature is above 0 ° C, the control unit 10 states that there is no risk of ice formation in the charge air cooler.

The control unit also receives information from sensor 13 which senses the temperature of the exhaust gases. During start-up of the vehicle and at times with a low load, the exhaust gases may have an unacceptably low level. When this is the case, the control unit 10 can set one of the fate elements 7a, 7b, 7c in the closed position so that the compressed air is led through one of the areas RA, RB, RC of the radiator package 3. During a cold start the third fate element 7c can be set in the closed position so that hot exhaust gases are obtained which quickly heat up the catalyst.

If the control unit 10 during operation of the vehicle receives information from the sensor 11 which indicates that the ambient air temperature is below 0 ° C, the control unit 10 finds that there is a risk of ice formation in the charge air cooler. The lower the temperature of the ambient air, the greater the risk that the compressed air is cooled to a ”IO temperature below 0 ° C so that ice forms in the charge air cooler. The control unit 10 receives substantially continuously information 12 regarding the load of the internal combustion engine 1.

During operating cases when the internal combustion engine 1 has a high load, a large fl fate of compressed air with a high temperature is led to the charge air cooler. Under such circumstances, usually the entire cooling portion 3 of the charge air cooler can be used to cool the compressed air without risk of ice formation in the charge air cooler. During operating times when the load is low, a relatively small air flow is led with a relatively low temperature to the charge air cooler. In this case, there is a great risk of ice formation in the charge air cooler. The control unit 10 determines, by means of received parameter values, how much the cooling must be limited in the radiator package 3 at different times, after which it closes one of the fate elements 7a, 7b, 7c by means of the respective electric motor 9a, 9b, 9c. In this case, the cooling in the radiator package 3 can be reduced in three different steps. In this case, as shown in Fig. 1, the second fate element 7b can be closed so that the compressed air through the area RB of the radiator portion 3. The compressed air is thereby led at a higher speed through the tubular elements 5 in the heat pipe RB than if it were is passed through all the tubular elements 5 in the radiator package 3. The compressed air thus does not have time to cool to the same low temperature as when the entire radiator package 3 is used for cooling the compressed air. The compressed one thus provides a cooling in the charge air cooler to a low temperature which, however, is higher than 0 ° C. The risk of ice formation in the charge air cooler is thus eliminated.

Fig. 2 shows an alternative embodiment of the invention. In this case, an electric motor 15 is used to position three fate elements 7a, 7b, 7c in an open position and in a closed position. The electric motor 15 is here adapted to displace a control rod 17 by means of a gear 16 which is connected to a rack 17d on the control rod 17. The control rod 17 comprises a guide surface 17e which are adapted to cooperate with a guide means 7a1, 7b1, 7c1 of the respectively fl fate elements 7a, 7b, 7c. The guide means 7a1, 7b1, 7c1 are arranged on a projecting portion which forms an angle of 90 ° towards the respective fate elements 7a, 7b, 7c. The guide surface 17e comprises three recesses 17a, 17b, 17c. The respective fate elements 7a, 7b, 7c comprise spring means which are adapted to provide a pressure force fi on the guide means 7a1, 7b1, 7c1 so that they are pressed against the guide surface 17e. When the control rod 17 is in a lower position, all the control means 7a1, 7b1, 7c1 are arranged in a respective recess 17a, 17b, 17c. Fig. 2 shows the control rod 17 as it continues upwards to a piece so that the first guide member 7a1 is taken out of the recess 17a.

When the first guide member 7a1 leaves the recess 17a, it is rotated 90 °. The control member 7a1 thus also rotates the first fate element 90 ° so that it is moved from the open position to the closed position. When the control rod 17 is moved a further distance upwards, the second guide member 7b1 is also displaced out of the recess 17b. The second control means 7a1 thus rotates the second fate element from the open position to the closed position. When the control rod 17 is moved a further distance upwards, the third guide member 7c1 is also displaced out of the recess 17c. The third control means 7c1 thus rotates the third ementet element 7c from the open position to the closed position. By displacing the control rod in different steps upwards from a lower starting position, the fate elements 7a, 7b, 7c can be successively displaced towards their closed positions by means of the electric motor 15.

In this case, the control unit 10 receives information from a sensor 14 which senses the temperature of the compressed air leaving the charge air cooler. As the compressed air leaving the charge air cooler has a temperature above 0 °, there is no risk of ice formation inside the charge air cooler. If the compressed air leaving the charge air cooler has a temperature below 0 ° C, the risk of ice formation inside the charge air cooler is imminent. Under these circumstances, the control unit 10 can activate the electric motor 15 so that it displaces the control rod 17 upwards so that the destructive element 7a, 7b, 7c which is arranged most upstream in the inlet tank 2 defines the area RA, RB, RC of the radiator portion 3 used for cooling. of the compressed air. During operation, the control unit 10 receives substantially continuously information from the sensor 14 regarding the temperature of the compressed air when it leaves the charge air cooler. The control unit can thus at relatively short intervals displace the control rod 17 between suitable positions so that the air leaving the charge air cooler has a continuously continuous temperature but which is always higher than 0 ° C. The control unit 10 here also receives information 12 regarding the load of the internal combustion engine. This information can enable the control unit 10 to steer the control rod 17 to suitable positions with increased precision. Also in this case, the control unit 10 receives information from a sensor 13 which senses the temperature of the exhaust gases.

The control unit 10 can thus also here reduce the capacity of the charge sensors during, for example, starting the vehicle to provide a required exhaust temperature at which the exhaust gases are purified in a desired manner.

The invention is in no way limited to the embodiment described in the drawing but can be varied freely within the scope of the claims. In the embodiments described above, the capacity of the charge air cooler is limited in three steps. It is of course possible to limit the capacity of the charge air cooler in two steps or in more than three steps.

Claims (10)

IO 15 20 25 30 35 10 Patent claim Arrangement for preventing icing in a charge air cooler comprising a radiator portion (3) where compressed air is cooled by ambient air flowing through the radiator portion (3), characterized in that the arrangement comprises a first fate element (7a) which is adapted in a closed position preventing compressed air from being passed through an area (A) of the radiator portion (3), a second fl element (7a) adapted in a closed position to prevent compressed air from passing through a second area (B) of the radiator portion (3) which is larger than the first area of the radiator portion (A), and a control unit (10) adapted to receive information regarding at least one parameter (11, 12, 14) which is related to the risk of ice formation in the charge air cooler and in the cases mentioned parameter indicates that there is a risk of ice formation in the charge air cooler, the control unit (10) is adapted to set one of the fl element elements (7a, 7b) in a closed position so that the compressed air is led through a reduced area (RA, R B) of the radiator section (3). Arrangement according to claim 1, characterized in that the larger area (B) of the radiator portion (3) comprises the entire smaller area (A) of the radiator portion (3). Arrangement according to claim 1 or 2, characterized in that the arrangement comprises at least a third fate element (7c) which in a closed position is adapted to prevent compressed air from being passed through a third region (C) of the radiator portion which is larger than the second region. of the radiator section (B). Arrangement according to one of the preceding claims, characterized in that the arrangement comprises a sensor (11) which is adapted to sense a parameter in the form of the temperature of the ambient air. Arrangement according to one of the preceding claims 1 to 4, characterized in that the arrangement comprises a sensor (14) which is adapted to sense a parameter in the form of the temperature of the compressed air which is led out of the charge air cooler. Arrangement according to one of the preceding claims, characterized in that the control unit (10) is adapted to provide information regarding a parameter which is related to the load of an internal combustion engine (1). 10 15 20 11 Arrangement according to any one of the preceding claims, characterized in that the charge cooler comprises a tank (2, 4) arranged to receive the compressed air before or after it has been cooled in the cooler portion (3), said fate element (7a, 7b, 7c) are arranged inside said tank (2, 4). Arrangement according to one of the preceding claims, characterized in that the control unit (10) is adapted to use separate bead members (9a, 9b, 9c) for setting the individual fl fate elements (7a, 7b, 7c) in desired positions. Arrangement according to one of the preceding claims 1 to 7, characterized in that the control unit (10) is adapted to use a common force means (15) and a motion transmitting mechanism (16, 17, 7a1, 7b1, 7c1) for setting the individual fl fate elements. (7a, 7b, 7c) in desired positions. Arrangement according to claim 9, characterized in that the motion transmitting mechanism (16, 17, 7a1, 7b1, 7c1) comprises a slidably arranged control rod (17) and that the individual fate elements (7a, 7b, 7c) comprise contact means (7a1, 7b1 , 7c1) adapted to be in contact with a guide surface (17e) of the control rod (17).