The present disclosure relates generally to a cooling system and, more particularly, to a cooling system having an anti-recirculation feature configured to enhance engine cooling.
Most mobile machines are powered by an internal combustion engine, for example a diesel engine, a gasoline engine, or a gaseous-fuel powered engine. Each of these engines combust a mixture of fuel and air to generate a mechanical power output used to propel the machine. With the purpose to ensure optimum combustion of the fuel/air mixture and protect components of the engine from damaging extremes, temperature of the engine and air drawn into the engine for combustion should be tightly controlled.
Typical internal combustion engines are cooled by way of a heat exchanger and an axial cooling fan disposed adjacent (e.g. in front of or behind) the heat exchanger. Coolant from the engine is circulated through the heat exchanger, while the axial cooling fan directs a flow of fresh air through the heat exchanger to absorb heat from the coolant. The coolant, having dissipated heat to the air, is then circulated back through the engine to cool the engine. The air, after having absorbed heat from the heat exchanger, is directed to the atmosphere.
Unfortunately, not all of the air directed by the fan through the heat exchanger is fresh and cool and capable of adequately absorbing significant amounts of heat from the engine. In particular, conventional cooling fans generate a flow of air having a higher pressure at an outer periphery than at an axial center. In some situations, this pressure gradient can cause some of the higher pressure air at the outer periphery to reverse direction after passing through the heat exchanger and be drawn back through the lower pressure center of the heat exchanger. This recirculated air has an elevated temperature that can reduce an efficiency of the heat exchanger.
An attempt to address one or more of the problems described above is disclosed in U.S. Pat. No. 5,180,003 that issued to Kouzel et al. on Jan. 19, 1993 (the '003 patent). Specifically, the '003 patent describes a cooling system having a dual-fan architecture, including a primary fan and a smaller secondary fan. The primary fan is disposed at one side of a heat exchanger to push air through the heat exchanger, while the smaller secondary fan is disposed at an opposing side of the heat exchanger to pull air through the heat exchanger. The smaller secondary fan is located at an area of lowest air flow at a center of the primary fan and is intended to eliminate recirculation of air back through the heat exchanger.
Although the dual-fan architecture of the '003 patent may help to reduce air recirculation through the heat exchanger, it may also be complicated, expensive, and difficult to package. In addition, the added fan and associated mounting and control components may decrease a reliability of the cooling system.
The cooling system is directed to overcoming one or more of the problems set forth above and/or other problems of the prior art.
In one aspect, the present disclosure is directed to a cooling system. The cooling system may include a heat exchanger fluidly connectable to the engine, and a fan situated adjacent the heat exchanger and configured to generate a flow of air through the heat exchanger. The cooling system may also include an anti-recirculation feature located adjacent the fan and configured to block the flow of air at a center of the fan and allow air to flow at a periphery of the fan.
In another aspect, the present disclosure is directed to an engine grill. The engine grill may include an end portion, and a plurality of perforations formed within the end portion in a pattern around a middle of the end portion. The engine grill may also include an anti-recirculation feature situated at the middle of the end portion within the pattern of the plurality of perforations.
As shown in
In the disclosed embodiment, fan 28 may be located between heat exchanger 26 and cowling 20 to draw air from inlets 22 of housing 18 through heat exchanger 26, and push the air out through and end of cowling 20. Fan 28 may include, among other things, a hub 30 and a plurality of inclined blades 32 that extend radially outward from hub 30. Fan 28 may be driven by engine 14 directly (e.g., via a mechanical connection such as a pulley or gear drive) or indirectly (e.g., via a hydraulic or electric motor 34), and include mounting hardware 36 configured to fixedly connect fan 28 to engine cowling 20. Fan 28 may also be pivotally connected to heat exchanger 26 (e.g., at a lower edge of heat exchanger 26) such that fan 28 and heat exchanger 26 may together form a door to enclosure 16 (referring to
Cowling 20 may include an engine grill 40 located at an end thereof. Engine grill 40 may be configured to allow the air flow generated by fan 28 to pass through cowling 20, while simultaneously inhibiting passage of debris larger than a certain size. In particular, as shown in
Engine grill 40 may include a generally planar first portion 46 and a generally planar second portion 48 that is located below first portion 46 (i.e., between first portion 46 and frame 12). As shown in
Anti-recirculation feature 44 may be designed to enhance performance of cooling system 24. In particular, anti-recirculation feature 44 may have geometry and be located to inhibit recirculation of warm air through heat exchanger 26. Specifically, anti-recirculation feature 44 may have an outer diameter D1 greater than an outer diameter D2 of hub 30 (referring to
The disclosed cooling system, together with engine 14, may form a power unit applicable to any mobile or stationary machine where efficient engine cooling is desired. The disclosed cooling system may improve cooling efficiency by reducing an amount of air that is recirculated through an associated heat exchanger. The disclosed cooling system may employ anti-recirculation feature 44 to reduce the amount of recirculated air. In particular, anti-recirculation feature 44 may block higher pressure air flow from the outer periphery of fan 28 from being drawn back through a lower pressure center of fan 28 and heat exchanger 26. In this manner, a greater amount of cool fresh air may pass through heat exchanger 26, thereby increasing an amount of cooling and an associated efficiency of heat exchanger 26. In fact, it has been demonstrated that anti-recirculation feature 44 may actually increase airflow through heat exchanger 26 by 5% or more. Noise reduction has also been shown to occur through the use of anti-recirculation feature 44.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed cooling system without departing from the scope of the disclosure. Other embodiments of the cooling system will be apparent to those skilled in the art from consideration of the specification and practice of the thermal management system disclosed herein. For example, in an alternative configuration described above, where fan 28 is located between engine 14 and heat exchanger 26 in opposition to engine cowling 20, it is contemplated that anti-recirculation feature 44 may be a stand-alone component (i.e., separate from engine grill 40) and located adjacent fan 28 at an upstream or downstream side of fan 28. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.