A Cooling System

Abstract

A cooling package for a vehicle, such as an agricultural tractor, having a charge air cooler assembly configured such that airflow is routed through a charge air cooler multiple times in order to cool a compressed charge of air. As the temperature rise experienced by the cooling airflow is relatively minor compared to the initial temperature of the compressed charge of air, the airflow is initially routed through an outlet-side portion of the charge air cooler to cool the compressed charge of air towards the outlet side of the charge air cooler, and subsequently routed through an inlet-side portion of the charge air cooler to cool the compressed charge of air towards the inlet side of the charge air cooler.

Claims

1. A cooling package for a vehicle, comprising at least one heat exchanger; a fan arranged to create a flow of air through the at least one heat exchanger; and a charge air cooler (CAC), the CAC comprising: an inlet to receive a compressed charge of air; an outlet to provide a cooled compressed charge of air for an engine; and a plurality of parallel flow paths for flow of a compressed charge of air between the inlet and the outlet, the plurality of parallel flow paths defining an inlet-side portion and an outlet-side portion of the CAC, wherein the fan is arranged to create a flow of air initially through the outlet-side portion of the CAC, to cool the compressed charge of air in the portion of the flow paths in the region of the outlet, the air subsequently routed through the inlet-side portion of the CAC, to cool the compressed charge of air in the portion of the flow paths in the region of the inlet.

2. The cooling package of claim 1, wherein the charge air cooler assembly comprises a flow duct, wherein the flow duct is arranged to route coolant from an outlet-side portion of the CAC to an inlet-side portion of the CAC, wherein at least a portion of the flow duct forms part of a shroud for the fan.

3. The cooling package of claim 1, wherein the cooling package comprises an engine radiator as a heat exchanger.

4. The cooling package of claim 1, wherein the inlet and the outlet of the CAC are arranged along an axis, the axis extending parallel to a rotational axis of the fan.

5. The cooling package of claim 1, wherein the at least one heat exchanger of the cooling package comprises: a first heat exchanger arranged upstream of the fan; a second heat exchanger located downstream of the fan; and the CAC in fluid connection with the fan, the CAC arranged in parallel to the first and second heat exchangers.

6. The cooling package of claim 5, wherein the CAC is located laterally adjacent to a flow path defined between the first and second heat exchangers.

7. The cooling package of claim 1, wherein the fan is located upstream of the outlet-side portion of the flow paths of the CAC assembly, the fan arranged to blow a flow of air through the outlet-side portion of the CAC, the flow of air subsequently routed to flow through the inlet-side portion of the CAC.

8. The cooling package of claim 1, wherein the fan is located downstream of the inlet-side portion of the flow paths of the CAC assembly, the fan arranged to draw a flow of air through the outlet-side portion of the CAC, the flow of air subsequently routed to flow through the inlet-side portion of the CAC.

9. The cooling package of claim 1, wherein the fan is located downstream of the outlet-side portion of the CAC and upstream of the inlet-side portion of the CAC, the fan arranged to draw a flow of air through the outlet-side portion of the CAC and to subsequently blow the flow of air through the inlet-side portion of the CAC.

10. The cooling package of claim 9, wherein the fan is arranged such that a portion of the fan swept area extends into the space defined by a flow duct arranged adjacent the CAC.

11. The cooling package of claim 10, wherein the flow duct is arranged to route coolant flowing through an outlet-side portion of the CAC to flow through an inlet-side portion of the CAC.

12. The cooling package of claim 9, wherein the fan is located off-centre to a flow path through the at least one heat exchanger, the fan located close to the CAC, such that a first portion of the flow generated by the fan flows through the first and second heat exchangers, and a second portion of the flow generated by the fan flows.

13. An agricultural vehicle, comprising a cooling package having a charge air cooler assembly as claimed in claim 1.

14. The vehicle of claim 13, wherein the fan of the cooling package is arranged such that the rotational axis of the fan is transverse to the longitudinal axis of the vehicle, extending between the front and the rear of the vehicle.

15. The vehicle of claim 14, wherein a first and second heat exchangers are arranged parallel to the fan along the longitudinal axis of the vehicle, and wherein the CAC is arranged in series with the fan along the longitudinal axis of the vehicle.

16. An agricultural vehicle such as a tractor, having a longitudinal axis extending between the front and the rear of the vehicle, the vehicle comprising: an engine; a cab located rear of the engine; and a cooling package located between the engine and the cab, the cooling package comprising a fan and at least one heat exchanger, the fan and at least one heat exchanger each having a major axis arranged parallel to the longitudinal axis of the vehicle, the cooling package arranged to generate a flow of air through the at least one heat exchanger in a direction transverse to the longitudinal axis of the vehicle, wherein the cooling package further comprises at least one charge air cooler (CAC), the CAC arranged adjacent to the fan, wherein the CAC has a major axis arranged transverse to the longitudinal axis of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0059] FIG. 1 is a side plan view of an agricultural tractor according to an embodiment of the invention;

[0060] FIG. 2 is an isometric perspective view of a cooling package of the tractor of FIG. 1;

[0061] FIG. 3 is a top-down cross-sectional view of the cooling package of FIG. 2, according to a first embodiment of the invention;

[0062] FIG. 4 is an illustrative view of a cooling package according to a second embodiment of the invention;

[0063] FIG. 5 is an illustrative view of a cooling package according to a third embodiment of the invention;

[0064] FIG. 6 is a side plan view of an agricultural tractor according to a further embodiment of the invention; and

[0065] FIG. 7 is a top plan view of the tractor of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0066] In FIG. 1, an agricultural tractor is indicated at 10. The tractor 10 comprises front wheels 12, rear wheels 14, an engine section 16 and a cab section 18. An engine 20 is provided in the engine section 16, with a cooling package 22 located adjacent the engine 20.

[0067] The tractor 10 comprises an Engine Control Unit (ECU, not shown), which is configured to control the operation of the engine 20 of the tractor 10, as well as any additional vehicle systems, based on input received from the tractor operation and/or any tractor sensor systems.

[0068] A cooling package 22 is illustrated in FIG. 2. The cooling package 22 comprises a first heat exchanger assembly 24, a second heat exchanger assembly 26, and an engine fan (28, FIG. 3) arranged between the first and second heat exchanger assemblies 24, 26. The fan 28 is arranged such that a first side 28a of the fan faces the first heat exchanger assembly 24, and a second side 28b of the fan 28 faces the second heat exchanger assembly 26. The fan 28 is configured to rotate to draw in air through the first heat exchanger assembly 24 and to expel the air out through the second heat exchanger assembly 26, as indicated by the respective sets of arrows A,B shown in the cross-sectional view of FIG. 3. It will be further understood that the fan 28 may further be configured to rotate in a reverse direction, and/or to have reversible fan blades, such that a reverse air flow through the heat exchangers 24,26 can be facilitated, e.g. for cleaning of accumulated dust and debris. The cooling package 22 further comprises a duct or cowling 30 arranged to route air between the first and second heat exchanger assemblies 24,26 through the fan 28.

[0069] A charge air cooler (CAC) assembly 32 is arranged to one side of the fan 28, the CAC assembly 32 oriented substantially parallel to the rotational axis of the fan 28. The CAC assembly 32 receives a compressed charge of air, preferably from a turbocharger or a supercharger (not shown), preferably to be used in the engine 20. The CAC assembly 32 comprises an inlet 34 for receiving a hot compressed charge of air and an outlet 36 for providing a cooled compressed charge of air, the inlet 34 and outlet 36 arranged either side of a body portion 38 of the CAC assembly 32. An array of flow paths (not shown) are arranged in the body 38 of the CAC assembly 32, the flow paths running in parallel between the inlet 34 and the outlet 36. The flow paths may comprise a plurality of flow tubes or ducts connecting the inlet 34 and the outlet 36. The CAC assembly 32 is arranged to allow for cooling air to flow through the body 38 of the CAC assembly 32, to cool the compressed charge of air carried in the flow paths of the body 38.

[0070] The duct 30 of the cooling package 22 is coupled with the CAC assembly 32, such that a first face 38a of the body 38 of the CAC assembly 32 is open to the interior of the cooling package 22, the body of the CAC assembly 32 further comprising a second opposed face 38b. The CAC assembly 32 is positioned such that the midpoint of the flow paths between the inlet 34 and the outlet 36 is substantially in line with the lateral axis of the fan 28, such that an outlet-side section 36a of the flow paths of the CAC assembly 32 are arranged to the first side 28a of the fan 28, and an inlet-side section 34a of the flow paths of the CAC assembly 32 are arranged to the second side 28b of the fan 28.

[0071] In addition to the airflow A,B through the first and second heat exchanger assemblies 24,26, the fan 28 is operable to generate an airflow through the body 38 of the CAC assembly 32. During normal rotation, the fan 28 is arranged such that airflow is initially drawn in through the outlet-side section 36a of the CAC assembly 32 (as indicated by arrow X), then passes through the fan 28, and is then routed out through the inlet-side section 34a of the CAC assembly 32 (as indicated by arrow Y).

[0072] As the temperature of the compressed charge of air at the outlet-side section 36a of the CAC is lower than at the inlet-side section 34a, a coolant used to initially cool the outlet-side flow can subsequently be used to cool the inlet-side flow. The coolant will experience a rise in temperature from cooling the outlet-side flow, but the relatively-warmer coolant will still remain at a temperature where it can cool the high-temperature inlet-side flow. The temperature of the compressed charge of air may be of the order of 200 degrees C. at the inlet 34 of the CAC, and approximately 50 degrees C. at the outlet 36. Accordingly, while the coolant flow will experience an increase in temperature when cooling the outlet-side flow of charge air, as such a temperature increase will be relatively minortypically of the order of 10 degrees C. the coolant may still be effectively used to cool the inlet-side flow of charge air.

[0073] This arrangement of the cooling package 22 with the CAC assembly 32 provides a multi-pass charge air cooler, with results in several advantages when compared to prior art systems. Firstly, as the coolant flow is routed such that the same flow of coolant is used twice to cool the flow of charge air, only a single fan and a single charge air cooler may be required to achieve the desired cooling of the charge air. Accordingly, the efficiency of the charge air system is increased. Furthermore, coolant from the first pass through the CAC is still cold enough to be re-used in a second pass through the CAC, or any other cooler. This allows for the exchange of more power via the coolant when compared to a single-pass CAC. Additionally, the pressure drop across the assembly may be reduced due to only a single charge air cooler being used, compared to prior art systems using multiple charge air coolers. In a further advantage, less physical space is taken up by the assembly, due to a reduction in the number of components.

[0074] The flow of air into and out of the second face 38b of the CAC assembly 32 may be facilitated using additional vents or grilles provided in the housing of the vehicle, where such additional vents or grilles may be oriented perpendicularly to existing vents or grilles used for flow of air into the cooling package 22.

[0075] The embodiment of FIGS. 2 and 3 illustrates a configuration wherein the CAC assembly 32 is positioned to the side of the cooling package 22, effectively resulting in an airflow through the CAC assembly 32 parallel to the flow of air through the cooling package 22 itself. It will be understood that further embodiments may be provided wherein the CAC assembly 32 is positioned upstream or downstream of the flow of air through a cooling package. Schematic examples of such embodiments are provided in FIGS. 4 and 5.

[0076] With reference to FIG. 4, a charge air cooler (CAC) assembly 132 is provided having an inlet 134, an outlet 136, and a body 138 extending therebetween, a plurality of parallel flow paths (not shown) arranged in the body 138 to provide for the flow of a compressed charge of air from the inlet 134 to the outlet 136. A fan 140 is coupled with the CAC assembly 132 via airflow ducts 142. The ducts 142 are arranged such that a flow path is defined through the body 138 of the CAC assembly 132, wherein airflow is initially routed through an outlet-side section 136a of the body 138 before subsequently being routed through an inlet-side section 134a of the body 138.

[0077] The fan 140 is located downstream of the CAC assembly 132, with regard to the normal direction of airflow through the fan 140. During operation, the fan 140 is configured to draw in air initially through the outlet-side section 136a of the body 138 and subsequently through the inlet-side section 134a, as indicated by the arrows. The airflow can then be routed to other cooling packages as required (not shown).

[0078] Similarly, FIG. 5 illustrates a comparable construction, wherein similar components are indicated via corresponding reference numerals, increased by 100. In the embodiment of FIG. 5, the fan 240 is located upstream of the CAC assembly 232, and coupled to the CAC assembly 232 via appropriate ducts 142. The fan 240 is accordingly arranged to blow air initially through the outlet-side section 136a of the body 138 and subsequently through the inlet-side section 134a, as indicated by the arrows. The airflow through the fan 140 may be initially drawn through other cooling packages as required (not shown).

[0079] The example embodiments of FIGS. 4 and 5 operate on the same principle as that of the embodiment of FIGS. 2 and 3, in that a cooling airflow may be routed multiple times through the body of the CAC to cool the compressed charge of air, the airflow initially passing through the CAC towards the outlet side of the CAC and subsequently routed through the CAC towards the inlet side of the CAC.

[0080] In the embodiment shown in FIG. 1, the cooling package 22 is provided at the front of the tractor 10, forward of the engine 20. In addition, the fan 28 of the cooling package 22 is aligned such that the rotational axis of the fan 28 is in line with and parallel to the longitudinal or front-rear axis of the tractor 10. In a further aspect of the invention, the charge air cooler assembly may be incorporated into different vehicle component configurations. In a particularly preferred embodiment, the charge air cooler assembly is provided as part of a cooling package having a fan, wherein the rotational axis of the fan is transverse to the longitudinal axis of the associated vehicle.

[0081] An alternative embodiment is illustrated in FIGS. 6 and 7, where an agricultural tractor is indicated at 300. The tractor 300 comprises front wheels 302, rear wheels 304, an engine section 306 and a cab section 308. An engine 310 is provided in the engine section 306, with a cooling package 312 located adjacent the engine 310. In contrast to the embodiment of FIG. 1, in FIG. 6 the cooling package 312 is positioned between the engine 310 and the cab section 308.

[0082] With reference to FIG. 7, the cooling package 312 comprises a first heat exchanger assembly 314, a second heat exchanger assembly 316, and an engine fan 318 arranged between the first and second heat exchanger assemblies 314,316. The cooling package 312 is arranged such that the cooling fan 318 is aligned with the main longitudinal axis of the tractor 10, wherein the rotational axis of the fan 318 is orthogonal to the longitudinal axis. Accordingly, the cooling package 312 provides for a transverse flow of air through the engine section 306 of the tractor 300, as shown by the airflow directions indicated by the arrows at Z. It will be understood that the fan 318 may be controlled by an appropriate ECU (not shown) to provide for forward and reverse flow through the cooling package 312.

[0083] This configuration provides numerous advantages to vehicle operation: In one aspect, air which is heated by passing through the heat exchangers 314,316 of the cooling package 312 is no longer directed over the engine 310 itself, thereby preventing unwanted additional heating of the engine 310. In addition, providing for a transverse air flow allows for the flow direction to be easily reversed, e.g. for the purposes of cleaning accumulated dirt and debris from the heat exchangers and associated grilles. Also, the positioning of a longitudinally-aligned cooling package between the engine 310 and the cab section 308 can allow for improved construction of tractor 300, having a reduced-width or wasp waist. Such a wasp waist construction can provide increased operator visibility, e.g. towards the front wheels 302 of the tractor 300, and/or improved turning circles of the tractor 300, by providing additional space for the front wheels 302 to be pivoted into.

[0084] In the embodiment shown in FIGS. 6 & 7, a CAC 320 is provided as part of the cooling package 312, wherein the CAC 320 is positioned adjacent the fan 318 and the heat exchangers 314,316. The CAC 320 arranged in series with the fan 318 along the longitudinal axis of the vehicle 300, between the fan 318 and the cab section 308. However, it will be understood that the CAC 320 may be positioned in any other suitable alignment. For example, the CAC 320 may be positioned above or below the fan 318. In such a configuration, the CAC 320 can be arranged to lie flat relative to the other components of the cooling package 312. This arrangement may be preferred in an effort to reduce the length of the cooling package 312 in the longitudinal direction of the tractor 300. Alternatively, the CAC 320 may be positioned between the fan 318 and the engine 310.

[0085] While the embodiments of FIGS. 6 & 7 show the longitudinally-aligned cooling package 312 positioned between the engine 310 and the cab section 308, it will be understood that such a cooling package may alternatively be arranged at the front of the tractor 300, forward of the engine 310, and aligned to provide transverse airflow through the cooling package 312.

[0086] It will be understood that the arrangement of the longitudinally-aligned cooling package may be combined with any or all of the features of the embodiments shown in FIGS. 1-5.

[0087] While the above embodiments illustrate a two-pass charge air cooler assembly, wherein airflow is routed through the CAC twice, it will be understood that additional ducts may be used to provide a multi-pass CAC, wherein airflow is routed through the CAC multiple times, in a direction from the outlet side towards the inlet side of the CAC.

[0088] The invention provides for a charge air cooler construction and assembly, and the subsequent use of such a system in a cooling package of a vehicle, which provides for improved performance efficiency and reduced volume, when compared to the prior art.

[0089] While the above-described embodiment illustrates the construction of a cooling system having a charge air cooler, it will be understood that the principle of the invention may also apply to any cooling system having a heat exchanger with a low internal mass flow compared to an external coolant airflow, where the motivation is to provide outlet temperature of internal fluid flow as close as possible to coolant temperature.

[0090] The invention is not limited to the embodiments described herein, and may be modified or adapted without departing from the scope of the present invention.