US20110214844A1

US20110214844A1 - Cooling system for cooling of at least one circulating fluid, and a machine comprising the cooling system

Info

Publication number: US20110214844A1
Application number: US12/998,682
Authority: US
Inventors: Henrik Jacobsson; Goran Toumas
Original assignee: Atlas Copco Rock Drills AB
Current assignee: Epiroc Rock Drills AB
Priority date: 2008-12-22
Filing date: 2009-12-18
Publication date: 2011-09-08
Also published as: AU2009330784B2; SE0802650A1; EP2361361A4; WO2010074638A1; AU2009330784A1; EP2361361A1; SE533313C2; CN102257329A

Abstract

The present invention concerns a cooling system for cooling of at least one circulating fluid. The cooling system comprises at least one cooling unit (20) comprising: an air inlet (22) arranged in a first side surface (35); an air outlet (23) arranged in a second side surface (36); a fan for creating an air flow through the unit from the air inlet (22) to the air outlet (23); a cooling element (30) through which at least one fluid is circulating and which is placed in the air flow through the unit (20). The invention is characterized in that the cooling unit comprises a passage (37), which extends between the air inlet (22) and the air outlet (23) through which the air flow flows and in which the flow direction of the air flow is redirected by a redirection plate (24) so that the air flow in to, and out of the cooling unit (20) are separated, and that the size of the cross section area in the air inlet (22) and along the passage (37) that extends between the air inlet (22) and the air outlet (23) as well as in the air outlet (23) is mainly constant. The invention also concerns a machine (10) comprising the cooling system according to the invention.

Description

TECHNICAL FIELD

The invention relates to a cooling system for cooling of at least one circulating fluid, according to the preamble of patent claim 1.
The invention furthermore relates to a machine comprising one, or a plurality, of such cooling systems according to claim 12.

BACKGROUND

At different types of ground and construction works, and during mining, different types of machines and vehicles are used in order to facilitate and increase the efficiency of the work. Vehicles that may be used are e.g. drill rigs, asphalting machines, excavation machines etc. In common for all these machines are that they are exposed to surrounding air comprising particles and waste material which deteriorate several of the systems and components of the machines and vehicles that are essential in order to make the machines and the vehicles work satisfactory.
An important system in all these machines and vehicles is the cooling system that prevents overheating of the driving motor and the rest of the heat generating equipment, which otherwise would result in expensive and time consuming shutdowns. The cooling systems may have different designs, but in all systems the surrounding air is used in order to in an appropriate way directly cool one or more components that are in need of cooling, alternatively a fluid that flows in a cooling system is cooled and later on used for preventing a component, or the components, from being overheated and break down.
However, the use of the surrounding air for cooling of the fluid of the cooling system leads to some severe consequences when air pollutants and particles are accompanying the air that is flowing into the system, and/or the machine or the vehicle where they are deposited on the cooling element etc. These deposited particles are polluting the interior of the system and/or the machine, which considerably deteriorate the efficiency of the system, and increases the risk of breakdowns considerably. Furthermore, the cooling system has to be dimensioned with an overcapacity to avoid breakdowns when the capacity of the cooling system decreases.
Thus, there is a need for an improved cooling system, which increases the reliability of the machines or vehicles where it is installed.

SUMMARY OF THE INVENTION

The present invention intends to solve the above described problems. The object is achieved by a cooling system for cooling of at least one circulating fluid, which is stated in the independent claim.
The problems are solved by a cooling system for cooling of at least one circulating fluid. The cooling system comprises at least one cooling unit comprising:

- an air inlet arranged in a first side surface;
- an air outlet arranged in a second side surface;
- a fan for creating an air flow through the unit from the air inlet to the air outlet;
- a cooling element through which a fluid is circulating and which is placed in the air flow through the unit.

Whereby the invention is characterized in that the cooling unit comprises a passage, which extends between the air inlet and the air outlet through which the air flow flows and in which the flow direction of the air flow is redirected by a redirection plate so that the air flow in to, and out of, the cooling unit are separated, and that the size of the cross section area in the air inlet and along the passage that extends between the air inlet and the air outlet as well as in the air outlet is mainly constant.
By separating the air flows in to, and out of, the cooling unit the performance of the cooling unit is improved since air, that is already heated, flowing out from the cooling unit is prevented from being mixed with the air that is about to flow into the cooling unit. Thereby a lower temperature of the air flowing into the unit is obtained, which means that the cooling efficiency of the unit is improved.
The air flow into the cooling unit has a flow direction. The flow direction of the air flow is then redirected in the cooling unit so that its flow direction when the flow exits the cooling unit is different from the flow direction at the air inlet. The difference between the inlet direction and the outlet direction is determined by the intended use of the cooling unit, and the design of the cooling unit.
In an embodiment of the cooling unit the cooling unit mainly has the shape of a cuboid where the air inlet is arranged in one side surface of the cuboid while the air outlet is arranged in a second side surface, which means that the redirection is between 80° and 90°. If the cooling unit has another shape the redirection is adapted to this specific shape. The redirection will then preferably be between 45° and 100° since larger redirection leads to larger flow losses, which thereby not is desirable.
A further essential advantage with the cooling system according to the invention is that the cooling unit is designed as a separate unit where all the components influencing the air flow through the cooling unit are arranged within the cooling unit. The components that determine the cooling efficiency of the cooling unit is the selection of radiator, the efficiency of the fan and the size of the cross sectional area of the passage, which all are comprised in the cooling unit. This means that the air flow, which is directly proportional to the cooling efficiency of the cooling unit, is not hindered by other components placed in the vicinity of the cooling unit. The air flow through the cooling unit is thereby independent of possible changes of elements/components outside of the cooling unit. Thus, it will be easier to dimension and predict what cooling efficiency actually will be obtained from the cooling system.
Since the size of the cross sectional area in the air inlet, along the passage and in the air outlet is mainly constant, constrictions that limits the air flow through the cooling unit are avoided, and thereby also the cooling efficiency of the cooling unit which is directly proportional to the flow through the cooling unit. The shape of the air inlet, the passage and the air outlet may be varied as long as the size of the cross sectional area is mainly constant. Possible changes of the cross sectional shape of the passage along the passage should not have sharp curvatures/changes in order to avoid flow losses.
The selection of radiator, fan device and the size of the cross section area of the passage decide the cooling efficiency of the cooling unit and all of these parameters are comprised within the cooling unit, which thus means that the air flow will be controlled by active choices of the comprised parameters. The redirection plate in the cooling unit reduces the flow losses in the cooling unit. The redirection plate has a suitably even curvature adapted to the redirection that takes place in the unit.
At the air inlet of an embodiment of the invention inlet lamellae are arranged partly covering the air inlet. The object of these is to reduce the amount of noise emitted from the cooling unit and prevent water and particles etc. from entering the cooling unit.
In an embodiment of the invention, outlet lamellae are arranged at the air outlet, said outlet lamellae at least partly covering the air outlet in order to direct the air flow from the cooling unit in the desired direction, and to reduce the amount of noise emitted from the cooling unit.
The inlet lamellae, as well as the outlet lamellae, could be provided with a noise absorbing cover in order to further reduce the noise emitted from the unit.
The inlet lamellae as well as the outlet lamellae could also be replaced by appropriate touch protection such as e.g. a net or similar.
In an embodiment of the cooling system the fan comprises a fan wheel placed parallel to the first side surface of the cooling unit in connection to the air inlet of the cooling unit. This position results in a satisfactory air flow through the unit and in that service and cleaning are facilitated since the wheel is arranged close to one of the openings in the unit.
In an embodiment of the cooling system the fan comprises a fan wheel placed parallel to the air outlet of the cooling unit in connection to the second side surface of the cooling unit. This position also results in a satisfactory air flow through the unit and in that service and cleaning are facilitated since the wheel is arranged close to the second opening of the unit.
In an embodiment of the cooling system, the cooling element is placed inside the inlet lamellae in the vicinity of the air inlet. This position of the cooling element is very advantageously since the air flow will pass the cooling element immediately after having passed the lamellae at the air inlet and will accordingly still have a low temperature, which is important to achieve a high cooling efficiency of the fluid in the cooling element.
In an embodiment of the cooling system deflection plates are arranged in the cooling unit in order to reduce the flow losses in the air flow and thereby ensuring the maximizing of the air flow through the cooling unit. The use of deflection plates imply that the flow losses in the air flow are reduced considerably since the deflection plates are positioned at selected places in the unit to facilitate the redirection of the air flow and reduce the vortex formation in the cooling unit.
In an embodiment of the cooling system, the inlet lamellae are turnably arranged outwardly at the air inlet. This embodiment is very advantageously since much waste and particles after some use will be accumulated on the inlet lamellae and they will be easy to clean e.g. by flushing streaming water when they are turned outwardly outside of the cooling unit.
In an embodiment of the cooling system, the cooling unit comprises rotation actuators so that when the inlet lamellae are turned outwardly, the cooling element could also be turned outside of the first side surface of the cooling unit where the air inlet is situated. Since much waste and particles after some use will be accumulated on the cooling element, which reduces its cooling efficiency of the fluid flowing through the cooling element, it is advantageously if also the cooling element easily could be cleaned, e.g. by flushing of streaming water when they are turned outwardly outside of the cooling unit.
In an embodiment of the cooling system, the cooling element comprises one, or a plurality of, pipe coils for one, or a plurality of fluids. If the cooling system is intended for used for cooling of a plurality of fluids each one of them has to be circulated in a separate pipe coil in the cooling unit.
In an embodiment of the cooling system, it comprises at least a pair of cooling units according to any of the embodiments above. The cooling system is at least partly enclosed by a housing, which has at least two side surfaces and an upper surface, whereby the air inlet of the cooling units are placed in the same, or different, side surfaces of the housing and the air outlet is placed in the upper surface of the housing. If the cooling unit not is able to supply all the cooling needed from the cooling system is it appropriate to extend the system with further cooling units. These are suitably placed according to the definition above in order to ensure that the air flows are kept separate.
In an embodiment of the cooling system above, the housing mainly has the shape of a cuboid where the air inlets are placed in two of the side surfaces and turned away from each other. This embodiment ensures that no heated air is entering the cooling units and the required cooling efficiency may be supplied by the cooling system.
The invention, as stated in the claims, is intended to be used in e.g. machines appropriate for ground works, drilling or similar. These machines comprise one or a plurality of cooling systems according to any of the definitions above, whereby the air inlet, or the air inlets, is placed in connection to anyone of the sides of the machine, and the air outlet, or the air outlets, is placed on a upper surface of the machine. A cooling system installed and arranged in this way is able to supply sufficiently cooling to big machines. The orientation of the air inlet at the side surfaces of the machine, the rear surface and/or the longitudinal surfaces, also reduces the amount of pollutions and particles sucked into the cooling system, since the amount of pollutions and particles in this area normally is low since it is situated far from the place where the working tools of the machine are placed. By placing the air outlet on the upper surface of the machine the outgoing air flow will not contribute to any vortex formation close to the ground, which otherwise would lead to further particles close to the air inlet.
In an embodiment of the machine the air inlet, or the air inlets, is/are placed at the longitudinal surfaces of the machine, where the pollutions normally are limited.
In the machine comprising the above mentioned cooling system, at least one fluid that is circulated in the cooling system is used for cooling the heat generating components in the machine.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in detail below with references to the figures, where;

FIG. 1 shows a complete drill rig schematically.

FIG. 2 shows a cross section of a pair of cooling units arranged together.

FIG. 3 shows a cooling unit schematically.

FIG. 4 shows selected parts of an embodiment of the cooling unit.

FIG. 5 shows an embodiment of selected parts of a cooling unit schematically in cross section.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, a drill rig 10 for different types of ground and construction works and in which the present invention e.g. may be used is schematically illustrated.
The drill rig comprises i.e. a longitudinal, movable arm 11, at which end drilling devices 12 are arranged, caterpillar treads 13 to propel the rig, a compartment 14 for the operator and an engine housing 15.
The engine housing 15 of the drill rig contains a plurality of components and systems that ensures that the rig work properly such as e.g. an engine that supplies the required power to the drill rig. Thus, the engine is used to e.g. propel the rig, move the longitudinal arm and to operate the drilling device. The engine, and a plurality of the different systems and components in the drill rig, produce a considerably amount of heat and thus, require cooling in order to avoid breakdowns and to ensure continuous operation during long periods. The necessity of cooling increases when the load is high and if the surrounding air temperature is high, which means that the drill rig has to have an efficient and reliable cooling system.
In FIG. 2 a cooling system comprising a pair of cooling units 20 according to the invention schematically in cross section is illustrated. The two cooling units 20 of the cooling system, which are shown separately in FIG. 5, are placed so that they mainly constitute the shape of a cuboid. Initially one cooling unit of the cooling system will be described since the cooling units are identical.
The cooling unit 20 comprises a partly enclosing housing 21 that mainly has the shape of a cuboid with somewhat rounded corners. The housing may also have other shapes to fit within the design of the machine where the cooling system is used. The cooling unit 20 comprises an air inlet 22 placed in a side surface 35 and an air outlet 23 placed in its upper surface 36. The surfaces adjacent to the surface where the air inlet is placed are closed and in the unit a redirection plate 24 is arranged so that a passage 37 from the air inlet 22 to the air outlet 23 is created. In this embodiment, the inside of the housing walls in combination with the redirection plate 24 constitutes the passage 37. In the schematic figure the redirection plate has the shape of a curved plate, but the shape of the redirection plate may also have a more dish shaped design. The passage may alternatively be designed as a separately curved pipe section arranged in an enclosed housing between the air inlet and the air outlet of the cooling unit. The design is preferably such that it covers the entire air inlet and air outlet of the cooling unit and thereby leading the entire air flow through the pipe section.
In the cooling unit in FIG. 2 the redirection plate 24 extends from the lower edge of the air inlet 22 to the edge of the air outlet 23 that is turned away from the air inlet and has a curved shape so that the air flow through the cooling unit 20 will change flow direction, i. e. is redirected, in the cooling unit 20. The air inlet 22 is partly covered by lamellae 26, which reduces the amount of particles that are sucked into the unit, and works as a protection that hinders possible objects from coming into and damaging the unit. The air outlet 23 also has lamellae 27 that partly cover the air outlet. However, the main function of these are to regulate the air flow out of the cooling unit 20 in a desired direction, suitably away from the operator compartment 14 of the drill rig, and other parts of the drill rig that possibly are sensitive. Both the lamellae 26 at the air inlet 22 and the lamellae 27 at the air outlet 23 will lower the emitted noise level from the cooling unit. The lamellae may be replaced by other profiles or noise reducing elements.
Inside the inlet lamellae the cooling element of the cooling unit is placed. The cooling unit may comprise one or a plurality of cooling elements, alternatively a cooling element divided in sections for different fluids. Through the cooling element the cooling fluid, or the cooling fluids, that shall be cooled flows through one or a plurality of pipe coils arranged in the air flow of the cooling unit. The cooling unit may have pipe coils for one or a plurality of fluids since different fluids are circulating in different coils to cool each component that they are intended for. E.g. one fluid may be used for cooling of the engine and another one for cooling of compressor or pump comprised in the hydraulic system of the drill rig. The cooling element may be design in different ways, but advantageously the area of the pipes, where the fluid is flowing, has a great area exposed to the air flow in order to ensure efficient cooling of the fluid in the pipe coil.
The lamellae 26 at the air inlet 22 are arranged in a lamella frame 28 that is hinged near the outer edge of the housing 21 of the cooling unit, not shown, so that they accordingly may be turned from the original placing. Also the cooling element 30 is turnably arranged where it is hinged in the cooling unit 20 so that the cooling element with its pipe coils may be turned outside of the cooling unit where it could be cleaned easily. This is illustrated in FIG. 4 and is made possible by the cooling element 30 that is attached with a hinge 31 at the housing of the cooling unit. The pipe coil of the cooling unit is attached to the cooling system by means of an elastic pipe 32. One section of the pipe 32 is hanging freely between the connection to the cooling element 30 and the cooling system so that the pipe 32 is able to follow the cooling element 30 when it is rotated outside of the cooling unit 20 without damaging the connections of the pipe 32. The cooling element has to be cleaned after being used some time to ensure that sufficient cooling efficiency is obtained when the particles and waste that after some time is collected on the cooling element deteriorate the cooling efficiency in the cooling element 30 considerably. In the figure, also by dotted lines, is the positions where the cooling element 30 and the inlet lamellae will have when they are in the collapsed neutral position illustrated.
The cooling unit 20 also comprises a fan intended to generate a forced air flow through the unit and thereby improving the cooling efficiency in the unit 20. The fan comprises a not shown fan engine and a wheel 51, shown in FIG. 5, positioned parallel to the side surfaces of the cooling unit inside the air inlet 22 and installed in an attachment structure 29. This placing makes inspection, cleaning and service of the fan easy. However, the wheel may also be positioned on other places along the air passage in the cooling unit 20.
Under the redirection plate 24 a space is created through which the air flow not is flowing. This space is suitably used for e.g. the pipes through which the cooling fluid is flowing and which are intended to be connected to the cooling element. Furthermore the engine, comprised in the fan, may be placed here if the axis is articulated in an appropriate way to the wheel. The cables comprised in the different systems in the drill rig may also pass though this space where they will be protected by the redirection plate.
In the cooling system comprising a pair 40 of cooling units the air inlets of the two cooling units 20 are turned away from each other. The two air outlets are placed in the upper surface of each cooling unit so that the air to each air inlet 22 is kept separated from the heated air flowing up from the air outlet 23. The lamellae 27 placed in connection to the two air outlets 23 may be used to direct the air flow either in one and the same direction, or separate the air flows from each outlet 23 and lead them in different directions.
In order to maximize the air flow through the cooling unit guide rails 50, shown schematically in FIGS. 2 and 5, may be arranged in the cooling unit. The guide rails, shown in FIGS. 2 and 5, are not drawn to scale, and only illustrated schematically in order to easier understand the design of the cooling system. The guide rails are composed of curved plates that extend laterally through the passage in the cooling unit in order to facilitate the redirection of the air flow. This is achieved by reducing the generation of vortexes and thereby creating a more laminar air flow through the passage. Less turbulence in the flow leads to reduced flow losses in the cooling unit. The number of guide rails is adapted depending on the size of the cooling unit and the expected air flow through the unit. The air flow to the cooling unit and the air flow from the cooling unit are illustrated with arrows.
In FIG. 5, an alternative embodiment of the inlet lamellae 26 that have a somewhat v shaped cross section, and a wheel 51 are shown. The wheel may have different designs depending on which fan capacity is needed.
In order to further reduce the amount of noise emitted from the cooling unit the inside of the surrounding housing may be insulated with therefore appropriate noise absorbing material.
In machines where the cooling unit 20, or the cooling module 40 are used, the inlet, or the inlets 22, are placed at the sides of the machine, where the amount of pollutions is small, while the air outlet 23, or air outlets 23, are arranged on the upper surface of the machine. This positioning facilitates the separation of the air flow to the cooling unit, or the cooling module, since the heated air flows upwards from the upper surface of the machine and continues in this direction, which prevents it from mixing with the air with lower temperature at the side surfaces of the machine.
The invention is described above in combination with the shown embodiments. Further modifications are however possible without deviating from the invention. E.g. may:

- the shape of the cooling unit be varied, e.g. by bending some of the sides, as long as the air flows to and from the unit or the module are kept separately.
- the cooling unit be designed in different ways in order to facilitate cleaning and service e.g. by making some parts of the housing, the air inlet, the air outlet detachable or able to open and thereby easier to clean efficiently.
- different types of wheels be used to produce the desired air flow through the unit and the module.

Even if the invention is described by some exemplified embodiments is the invention not limited to these, instead it is characterized by the accompanied patent claims.

Claims

1. Cooling system for cooling of at least one circulating fluid, whereby the cooling system comprises at least one cooling unit (20) comprising:

an air inlet (22) arranged in a first side surface (35);

an air outlet (23) arranged in a second side surface (36);

a fan for creating an air flow through the unit from the air inlet (22) to the air outlet (23); and

a cooling element (30) through which at least one fluid is circulating and which is placed in the air flow through the unit (20),

whereby the cooling system is characterized in that the cooling unit comprises a passage (37), which extends between the air inlet (22) and the air outlet (23) through which the air flow flows and in which the flow direction of the air flow is redirected by a redirection plate (24) so that the air flow in to, and out of, the cooling unit (20) are separated, and

that the size of the cross section area in the air inlet (22) and along the passage (37) that extends between the air inlet (22) and the air outlet (23) as well as in the air outlet (23) is mainly constant.

2. Cooling system according to claim 1, characterized in that the fan of the cooling unit comprises a fan wheel (51) placed parallel to the first side surface (35) of the cooling unit in connection to the air inlet (22) of the cooling unit.

3. Cooling system according to claim 1, characterized in that the fan of the cooling unit comprises a fan wheel placed parallel to the air outlet (23) of the cooling unit in connection to the second side surface (36) of the cooling unit.

4. Cooling system according to claim 1, characterized in that at the air inlet (22) inlet lamellae (26) are arranged that partly cover the air inlet (22) in order to prevent particles etc. from entering the cooling unit (20) and to reduce the amount of noise emitted from the cooling unit (20) to the surroundings.

5. Cooling system according to claim 1, characterized in that at the air outlet (23) outlet lamellae (27) are arranged, which at least partly cover the air outlet (23) to direct the air flow and to reduce the amount of noise emitted from the cooling unit (20) to the surroundings.

6. Cooling system according to claim 4, characterized in that the cooling element (30) is placed inside the inlet lamellae (26) in connection to the air inlet (22).

7. Cooling system according to claim 1, characterized in that in the cooling unit (20) a redirection plate (24) is arranged that guides the air flow between the air inlet (22) and the air outlet (23).

8. Cooling system according to claim 1, characterized in that in the cooling unit (20) deflection plates (50) are arranged in order to reduce the flow losses in the air flow.

9. Cooling system according to claim 4, characterized in that the inlet lamellae (26) are arranged being able to be turned outwardly at the air inlet (22).

10. Cooling system according to claim 9, characterized in that the cooling unit comprises rotation actuators (31) so that when the inlet lamellae (26) are turned outwardly, the cooling element (30) could be turned outside of the first side surface (35) of the cooling unit (20) where the air inlet (22) is situated.

11. Cooling system according to claim 1, any of the claims 1 to 10, characterized in that the cooling element (30) comprises one, or a plurality of, pipe coils for one, or a plurality of fluids.

12. Cooling system comprising at least a pair of (40) cooling units (20) according to claim 1, whereby the cooling system at least partly is enclosed by a housing (21), which at least has two side surfaces (35) and an upper surface (36), whereby the air inlet (22) of the cooling units (20) are placed in the same, or different, side surfaces (35) of the housing (21) and the air outlet (23) is placed in the upper surface (36) of the housing (21).

13. Cooling system according to claim 12, characterized in that the housing (21) mainly has the shape of a cuboid where the air inlets (22) are placed in two of the side surfaces (35) facing away from each other.

14. Machine (10) appropriate for ground works, drilling or similar comprising one or a plurality of cooling systems according to claim 1, whereby the air inlet (22), or the air inlets (22), are placed in connection to any of the sides of the machine, and the air outlet (23), or the air outlets (23), are placed on the upper surface of the machine (10).

15. Machine (10) according to claim 14, where the air inlet, or the air inlets, is/are placed at the longitudinal surfaces of the machine.

16. Machine (10) according to claim 14, where the at least one fluid circulating in the cooling system is used for cooling the heat generating components in the machine.

17. Cooling system according to claim 2, characterized in that at the air inlet (22) inlet lamellae (26) are arranged that partly cover the air inlet (22) in order to prevent particles etc. from entering the cooling unit (20) and to reduce the amount of noise emitted from the cooling unit (20) to the surroundings.

18. Cooling system according to claim 3, characterized in that at the air inlet (22) inlet lamellae (26) are arranged that partly cover the air inlet (22) in order to prevent particles etc. from entering the cooling unit (20) and to reduce the amount of noise emitted from the cooling unit (20) to the surroundings.

19. Cooling system according to claim 2, characterized in that at the air outlet (23) outlet lamellae (27) are arranged, which at least partly cover the air outlet (23) to direct the air flow and to reduce the amount of noise emitted from the cooling unit (20) to the surroundings.

20. Machine (10) according to claim 15, where the at least one fluid circulating in the cooling system is used for cooling the heat generating components in the machine.