Patent Application
20140290923
The present disclosure relates to a cooling system, and more particularly to a system and method for cooling a working fluid in a hydraulic system.
An engine is usually equipped with a radiator for cooling the engine using an appropriate coolant. The coolant from the radiator may also be used for a secondary application, such as, for example, cooling an oil used in a hydraulic circuit. In current systems, a hydraulic oil cooler is prone to plugging, is inaccessible for cleaning, and prevents access to clean the radiator. Hence, the hydraulic oil cooler needs to be relocated from the bottom of the cooling package to an area that can be cleaned easily. One possible solution includes moving the hydraulic oil cooler to a coolant circuit associated with a radiator. However, the temperature of the coolant associated with the radiator is relatively higher than that required by the hydraulic system installed on the machine.
U.S. Pat. No. 5,067,561 relates to a radiator apparatus. The apparatus includes an oil cooler located within the radiator tank. The oil cooler includes a plurality of pairs of tube plates wherein each pair defines tube. The coolant from the radiator tube is used to exchange the heat from the oil in the oil cooler.
In one aspect of the present disclosure, a cooling system is provided. The cooling system includes a first heat exchanger and a second heat exchanger. The first heat exchanger has a first chamber and a second chamber. A plurality of tubes is provided in the first heat exchanger such that the tubes are in fluid communication with the first chamber and the second chamber. The tubes are arranged in a plurality of rows. A baffle is located in the second chamber. The baffle divides the second chamber into a first region and a second region. The first region of the second chamber is in fluid communication with at least one row of tubes. Further, an outlet is provided in fluid communication with the first region. The second heat exchanger includes an inlet in communication with the outlet of the first region.
In another aspect, a method for cooling a working fluid in a hydraulic system is provided. The method receives a coolant in a first chamber of a first heat exchanger. The method introduces the coolant into a plurality of tubes, the tubes being arranged in a plurality of rows. The method directs the coolant through the plurality of tubes towards a second chamber of the first heat exchanger. The method provides a baffle in the second chamber. The baffle is configured to define a first region and a second region within the second chamber. The first region is in fluid communication with at least one row of tubes from the plurality of tubes. Further, the method introduces the coolant from the first region to a second heat exchanger.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
Wherever possible the same reference numbers will be used throughout the drawings to refer to the same or the like parts.
As illustrated in
Further, the machine 100 may include a load lifting assembly 110 having a lift arm 112, one or more hydraulic actuator 114 and a ground engaging tool 116, such as a blade or bucket. The ground engaging tool 116 is configured to collect, hold and convey material and/or heavy objects on the ground. The hydraulic actuators 114 may be configured to effectuate the movement of the lifting assembly 110 based on an operator command provided by an operator of the machine 100. The operator command may be received through various input devices present within an operator cabin 118 of the machine 100.
As shown in
In one embodiment, the first heat exchanger 202 may be a tube radiator, preferably a grommeted tube radiator. The first heat exchanger 202 may include a first chamber 306 and a second chamber 308. The first chamber 306 and the second chamber 308 may be fluidly connected to each other through a plurality of tubes 310. The plurality of tubes 310 connecting the first chamber 306 with the second chamber 308 may be placed substantially vertical within the first heat exchanger 202, such that the tubes 310 are arranged in a plurality of rows. The tubes 310 may be configured to convey the coolant from the first chamber 306 to the second chamber 308. It should be noted that each of the plurality of rows of tubes 310 may conduct the coolant from the first chamber 306 to the second chamber 308 independent of each other. The tubes 310 may be arranged in such a manner that one end of the tubes 310 is in fluid communication with the first chamber 306, while another end of the tubes 310 is in fluid communication with the second chamber 308.
Arrowheads shown in
One of ordinary skill in the art will appreciate that the drop in temperature of the coolant may vary in each of the row of tubes 310. The drop in temperature may depend on the location or position of the row of tubes 310 relative to the direction of the flow of the cooling medium 312. More specifically, the temperature drop in the coolant flowing in the initial few rows of tubes 310 may be relatively more than the drop in temperature experienced by the coolant flowing through the row of tubes 310 situated further away from the direction of flow of the cooling medium 312. For example, the temperature drop in first row of tubes 310 may be approximately 25% higher than the temperature drop in the row of the tubes 310 situated further away. Moreover, the temperature of the cooling medium 312 may continue to increase as the cooling medium 312 flows through the first heat exchanger 202, based on heat exchanged with the coolant flowing through the tubes 310. It should be understood that the first heat exchanger 202 is not restricted to the grommeted tube radiator, and may be any suitable type of heat exchanger for effective heat transfer between the coolant and the cooling medium 312.
As shown in
As shown in
In one embodiment, the second heat exchanger 204 may be a shell and tube type heat exchanger for exchanging heat between the working fluid used in hydraulic system and the coolant from the first heat exchanger 202. In another embodiment, the second heat exchanger 204 may be an in-tank cooler that may be placed in the first region 404 of the second chamber 308. More particularly, as shown in
Further, referring to
In one embodiment, the second chamber 308 of the first heat exchanger 202 may further include the outlet port 304 to fluidly connect the first heat exchanger 202 with the power source 102 via the fluid passage 208. The coolant from the second chamber 204 of the first heat exchanger 202 may be conveyed to the power source 102 from the outlet port 304 via the fluid passageway 208. It should be noted that this coolant may include the coolant leaving the row of tubes 310 present in the second region 406 of the first heat exchanger 202. Additionally, the coolant may also include the coolant received from the outlet 322 of the second heat exchanger 204 which is in communication with the second region 406 of the first heat exchanger 202.
In the present disclosure the coolant from the at least one row of tubes 310 of the first heat exchanger 202 is utilized to cool the working fluid in the second heat exchanger 204. Since the at least one row of tubes 310 are provided in the direction of the flow of the cooling medium 312, the coolant leaving this region of the first heat exchanger 202 is approximately 25% cooler than that leaving the second region. Further, the second heat exchanger 204 may remain in the cooling circuit of the first heat exchanger 202 having minimal or no effect on the flow rate and overall cooling system performance.
Referring to
As the coolant is conveyed from the first chamber 306 to the second chamber 308, the coolant may undergo the drop in temperature as a result of the heat exchange with the cooling medium 312 flowing over the plurality of tubes 310. At step 508, the baffle 402 may be provided within the second chamber 308. As described earlier, the baffle 402 may divide the second chamber 308 into the first region 404 and the second region 406. The first region 404 is in fluid communication with the at least one row of plurality of tubes 310. Further, the first region 404 may be provided in the direction of the cooling medium 312.
The cooling medium 312 may flow over the at least one row of tubes 310 in the first region 404 prior to that of the tubes 310 in the second region 406. As a result, the temperature drop of the coolant in the at least one row of tubes 310 of the first region 404 may be relatively higher than that of the second region 406. Further, at step 510, the coolant from the first region 404 may be introduced into the second heat exchanger 204. The coolant from the first region 404 of the second chamber 308 can be fed through the outlet 314 of the first region 404 to the inlet 316 of the second heat exchanger 204 through the fluid passage 210.
In one embodiment, the second heat exchanger 204 may utilize the coolant from the first region 404 of the second chamber 308 to cool the working fluid fed from the hydraulic system into the second heat exchanger 204. In one embodiment, the working fluid may be directed towards any suitable application in the machine 100. Further, the coolant from the second heat exchanger 204 may be fed back to the second chamber 308 of the first heat exchanger 202 through the outlet 322 of the second heat exchanger 204. The coolant from the first heat exchanger 202 may then be directed towards the power source 102 via the fluid passageway 208.
A person of ordinary skill in the art will appreciate that the connections described herein are exemplary and do not limit the scope of the disclosure. Also, the present disclosure has been explained with reference to the cooling system 200 for cooling the working fluid of the hydraulic system. However, the disclosure may also be utilized on other applications having similar requirements.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
