SINGLE PUMP COOLING ARRANGMENT

Abstract

A cooling arrangement having a first circuit and a second circuit in fluid communication of a coolant with each other. The cooling arrangement includes a pump configured to receive the coolant from the first circuit and the second circuit, and to re-circulate the coolant back to the first circuit and the second circuit. Further, the cooling arrangement includes an after-cooler disposed in the first circuit. A thermostat is provided in connection with the after-cooler to regulate a flow of the coolant supplied to the pump based on the temperature of the coolant from the after-cooler. Further, a bypass line is disposed in parallel to the thermostat in the first circuit. The bypass line is configured to provide a constant bleed of the coolant from the first circuit to the pump.

Description

TECHNICAL FIELD

The present disclosure relates to a cooling arrangement for a marine power system, and more particularly to the cooling arrangement using a single pump.

BACKGROUND

Typically, a marine power system employs a cooling arrangement for cooling of an engine, disposed therein. It is desired that the cooling arrangement with various components, may have the components to work at their operating temperature ranges for better performance. For this purpose, the cooling arrangement may utilize a two-circuit configuration, that is, the cooling arrangement include two different circuits for circulation of the coolant, with various components divided therein. Such cooling arrangement generally employs two separate pumps for circulation of the coolant in each of the two circuits of the cooling arrangement.

US Patent Publication No. 6,314,921 discloses a cooling system for an engine. The cooling system includes a radiator, and an after-cooler configured for cooling engine charge air from a turbocharger. Further, a pump is provided to supply the coolant from the radiator to the engine. A separate circuit after-cooling pump is provided to circulate the coolant from the radiator to the after-cooler. The cooling system further includes an after-cooler coolant line to provide a pathway for fluid communication between the after-cooler and the radiator. An orifice is disposed in series in the after-cooler coolant line to limit the fluid flow therethrough.

SUMMARY

In one aspect, the present disclosure provides a cooling arrangement having a first circuit and a second circuit. The first and the second circuits are in fluid communication of a coolant with each other. The cooling arrangement includes an after-cooler provided in the first circuit. Further, the cooling arrangement includes a pump configured to receive the coolant from the after-cooler in the first circuit and the second circuit. The pump is circulating the coolant back to the first circuit and the second circuit. A thermostat is disposed in connection with the after-cooler in the first circuit. The thermostat is configured to regulate the flow of the coolant provided to the pump based on the temperature of the coolant from the after-cooler. Further, a bypass line is provided in the first circuit parallel to the thermostat to provide a constant bleed of the coolant from the first circuit to the pump.

In another aspect, the present disclosure provides a marine power system including an engine. The marine power system includes the cooling arrangement, configured to extract heat from the engine by the coolant. The cooling arrangement includes the after-cooler for cooling the coolant to be supplied to the engine. The thermostat is provided in connection with the after-cooler and configured to regulate the flow of the coolant based on the temperature of the coolant from the after-cooler. Further, the bypass line is disposed in parallel to the thermostat to provide a constant bleed of the coolant from the after-cooler to the engine. An orifice is disposed in the bypass line to control the flow of the coolant through the bypass line.

In yet another aspect, the present disclosure provides a method for cooling the engine. The method includes receiving the coolant from the engine to the pump. The coolant from the pump is pumped to the after-cooler. The method further includes regulating the flow of the coolant from the after-cooler to the pump, to be supplied back to the engine, by the thermostat. Finally, the method involves providing the bypass line in parallel to the thermostat to provide the constant bleed of the coolant from the after-cooler to the engine.

Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic of a marine power system, according to an embodiment of the present disclosure; and

FIG. 2 illustrates a process flow diagram depicting various steps involved in cooling an engine.

DETAILED DESCRIPTION

The present disclosure will now be described in detail with reference being made to accompanying figures. A marine power system 100 in which disclosed embodiments may be implemented is schematically illustrated in FIG. 1. The marine power system 100 of the present disclosure may be employed to power various components of a machine, such as marine ships, recreational boats, or the like. The marine power system 100 may include an engine 102 to generate electric power (via a generator) for driving various components of the marine power system 100. In an embodiment, the engine 102 may be a combustion engine, such as, a gasoline, diesel or natural gas engine, etc.

The engine 102 may include an engine block 104, in which the combustion of fuel takes place. Further, the engine 102 may include an engine manifold 106, which may be in contact or partially enclose the engine block 104. The engine manifold 106 may receive and supply the fuel from some source, like a fuel tank, to the engine block 104. Further, according to an embodiment of the present disclosure, the engine manifold 106 may also be configured for receiving a coolant in the marine power system 100.

The marine power system 100 of the present disclosure includes a cooling arrangement 108. The cooling arrangement 108 may provide a flow of the coolant to extract heat, to be dissipated, from various components of the marine power system 100, and particularly the engine 102. In an embodiment, the coolant used in the cooling arrangement 108 may be any one of treated water; water mixed with mineral oils, silicone oils, cutting fluids and/or anti-freeze like ethylene glycol, di-ethylene glycol, etc.

In an embodiment, the cooling arrangement 108 may provide two circuits, namely, a first circuit 110 and a second circuit 112. In the exemplary configuration, the first circuit 110 may be working at a high temperature range, and the second circuit 112 at a low temperature range in the cooling arrangement 108. For the purpose of the present disclosure, In FIG. 1, the cooling arrangement 108 is illustrated with lines required only for the flow of the coolant. However, it may be contemplated that the cooling arrangement 108 may include additional lines, such as, for example, for the flow of charge air, sea-water, etc.

Further, the cooling arrangement 108 may include a pump 114, in fluid communication with the first and the second circuits 110, 112. In an embodiment, the pump 114 may be any type of a positive displacement pump, such as, a centrifugal pump having a construction well known in the art. The pump 114 may be configured to provide a pressure head for circulation of the coolant between the first circuit 110 and the second circuit 112, in the cooling arrangement 108.

The pump 114 may receive the coolant from the first and the second circuits 110, 112, of the cooling arrangement 108. Subsequently, the pump 114 may provide the pressure head to circulate the coolant back to the first and the second circuits 110, 112. In an embodiment, the coolant from the first and second circuits 110, 112 may mix within the pump 114, before being re-circulated back in the cooling arrangement 108.

In the marine power system 100, the coolant may be received by the engine 102, which is in connection with the second circuit 112 of the cooling arrangement 108. Specifically, the coolant may be received by the engine manifold 106 in the engine 102. The engine manifold 106 being in contact with the walls of the engine block 104, may extract the heat generated in the engine block 104 by the coolant, and supply the coolant back to the cooling arrangement 108 to dissipate the extracted heat.

Further, the cooling arrangement 108 may include a heat exchanger 116 disposed in the second circuit 112 of the cooling arrangement 108. The heat exchanger 116 may be disposed in connection with the engine 102 of the marine power system 100. In an embodiment, the heat exchanger 116 may be a jacket-water heat exchanger using sea-water for extracting heat gained by the coolant from the engine 102.

The cooling arrangement 108 may also include various other components, supporting the operation of the engine 102 in the marine power system 100. As illustrated, the cooling arrangement 108 may include an engine oil-cooler 118 and a turbocharger 120 disposed in the second circuit 112. The engine oil-cooler 118 may be utilized to cool the engine oil for the engine 102, by the coolant received from the pump 114. Similarly, the turbocharger 120 may be utilized to charge the air, for combustion of fuel, intake in the engine 102.

Further, in an embodiment, the cooling arrangement 108 may include an after-cooler 122 to cool the charge air, reducing an intake manifold air temperature for the engine 102. This may be required for better fuel economy and low emissions by the engine 102 in the marine power system 100. The after-cooler 122 may receive the charge air, from the turbocharger 120 via a line (not illustrated), and extract heat from the charge air by the coolant received from the pump 114. Subsequently, the cooled charge air may be supplied to the engine 102 in the marine power system 100.

For achieving better performance, the after-cooler 122 may be disposed in the first circuit 110, being the low temperature circuit, of the cooling arrangement 108. Further, in an embodiment, the cooling arrangement 108 may also include an after-cooler heat exchanger 124, disposed in connection with the after-cooler 122 in the first circuit 110. The after-cooler heat exchanger 124 may be configured to further cool the coolant supplied by the pump 114, from the first and the second circuit 110, 112, before being passed to the after-cooler 122 for cooling of the charge air.

In order to regulate the flow of the coolant, the cooling arrangement 108 may also include one or more thermostats disposed therein. In particular, the cooling arrangement 108 may include a thermostat 126 disposed in connection with the after-cooler 122. The thermostat 126 is configured to regulate the flow of the coolant from the first circuit 110 to the pump 114 based on the temperature of the coolant from the after-cooler 112. Specifically, the thermostat 126 may be configured to allow the coolant to flow to the pump 114 above a predetermined temperature limit.

In an embodiment, the cooling arrangement 108 may employ a triple thermostat configuration, that is, the cooling arrangement 108 includes three thermostats working in combination to regulate the flow of the coolant. In such a configuration, in addition to the thermostat 126, a first auxiliary thermostat 128 and a second auxiliary thermostat 130 may be provided in the first circuit 110 and the second circuit 112 of the cooling arrangement 108, respectively. For the purpose of the present disclosure, the thermostats 126, 128, 130 may be mechanically actuated thermostats, for example, a thermostatic radiator valve, a pneumatic thermostatic valve, or the like.

Specifically, the first auxiliary thermostat 128 may be disposed between the after-cooler heat exchanger 124 and the after-cooler 122 in the first circuit 110. The first auxiliary thermostat 128 may regulate the flow of the coolant from the pump 114 to the after-cooler 122, either via or bypassing the after-cooler heat exchanger 124. Similarly, the second auxiliary thermostat 130 may be provided between the heat exchanger 116 and the pump 114 in the second circuit 112. The second auxiliary thermostat 130 may regulate the flow of the coolant from the engine 102 to the pump 114, either via or bypassing the heat exchanger 116.

Further, the cooling arrangement 108 may include a bypass line 132 disposed in parallel to the thermostat 126. Specifically, the bypass line 132 may be extending from the line between the after-cooler 122 and the thermostat 126, to the line between the thermostat 126 and the pump 114. The bypass line 132 may enable the cooling arrangement 108 to route the flow of the coolant from the after-cooler 122 directly to the pump 114, bypassing the thermostat 126, and thus provides a constant bleed of the coolant in the cooling arrangement 108.

In an embodiment, the bypass line 132 may include an orifice 134 disposed within. The orifice 134 may be configured to control the flow of the coolant through the bypass line 132 in the cooling arrangement 108. In an embodiment, the flow of the coolant through the bypass line 132 may be dependent on the diameter of the orifice 134. In an embodiment, the diameter of the bypass line 132 may be in the range from about 2 to 12 millimeters. In an exemplary configuration, the diameter of the bypass line 132 is about 5 millimeters.

According to an alternative embodiment of the present disclosure, the bypass line 132, instead of being a separate line, may be formed within in the thermostat 126. That is, the bypass line 132 may be defined as an alternative path for the flow of the coolant in the thermostat 126, in addition to the regular path which allows the flow of the coolant therethrough based on the regulation on the basis of temperature. Therefore, in such a configuration, this additional path may function as the bypass line 132 with the orifice 134 disposed therein, and provides a controlled constant bleed of the coolant for the engine 102 in the cooling arrangement 108.

INDUSTRIAL APPLICABILITY

In operation, the engine 102 in the marine power system 100 may generate heat in the engine block 104 due to the combustion of the fuel. The generated heat may need to be dissipated for proper working of the engine 102 in the marine power system 100. Therefore, it is desired that the marine power system 100 may be provided with the cooling arrangement 108. The cooling arrangement 108 may supply the coolant to the engine 102 and extract heat in the process. Specifically, the cooling arrangement 108 may supply the coolant to the engine manifold 106, and extract heat generated from the engine block 104 in the engine 102. Further, the cooling arrangement 108 may dissipate the heat using various components working in combination.

It has been observed that for the efficient working of the cooling arrangement 108, various components may be disposed such as the components operate within the specified operating temperature ranges. For this purpose, the cooling arrangement 108 may be provided with two circuits, the first circuit 110 working at a high temperature range and the second circuit 112 working at a low temperature range. Conventional cooling arrangements utilizing such two-circuit configuration, typically employs two separate pumps, for each of the two circuits.

The present disclosure provides the cooling arrangement 108 for the marine power system 100, utilizing two-circuit configuration by employing only the single pump 114. This is made possible because the cooling arrangement 108 utilizes the triple-thermostat configuration, that is, the thermostats 126, 128, 130 working in conjunction with each other. The triple-thermostat configuration provides for better regulation of flow of the coolant based on the temperature and therefore allows for using a single pump 114 in the process.

The present disclosure also provides a method for cooling the engine 102 employing the cooling arrangement 108 with the single pump 114. FIG. 2 illustrates a process flow diagram 200 depicting various steps performed sequentially to achieve the purpose.

As illustrated, in step 202, the coolant from the engine 102 is received in the pump 114. This coolant, from the engine 102 via the second circuit 112, may mix with the coolant from the first circuit 110 of the cooling arrangement 108. Further, in step 204, the coolant from the pump 114 is supplied to the after-cooler 122, in the first circuit 110. As the coolant passes through the after-cooler 122, the temperature of the coolant may rise due to the gained heat, from cooling the charge air.

In certain cases, the temperature of the coolant, after passing through the after-cooler 122 in the first circuit 110, may still be at a substantially lower temperature to be supplied to the second circuit 112 for cooling of the engine 102 at a low load condition, that is, when the engine 102 is generating low heat in the second circuit 112.

Therefore, in step 206, the flow of the coolant back from the after-cooler 122 to the pump 114 is regulated via the thermostat 126. The thermostat 126 ensures that the temperature of the coolant flowing to the pump 114, to be supplied to the engine 102 after mixing in the pump 114, may be above a certain predetermined temperature to avoid overcooling of the engine 102.

As the load of the engine 102 is increased, the flow of the coolant may need to be increased. In such a situation, the thermostat 126 may not be able to instantaneously provide the required flow rate because of finite response time. So, as in step 208, the bypass line 132 is provided to route the coolant from the after-cooler 122 to the engine 102, via the pump 114.

The cooling arrangement 108 with the bypass line 132 ensures a constant bleed in order to provide flow of the coolant to the engine 102 at all times. This may be put in place to compensate for transient loading, that is, the sudden variation of load in the engine 102. The bypass line 132 may act to compensate for the finite response time of the thermostat 126 by allowing at least some flow of the coolant to the engine 102 in the second circuit 112.

Further, the cooling arrangement 108 may further be able to cope with varying cooling requirements of the marine power system 100 by relative positioning and combined operation of the thermostats 126, 128, 130 in the cooling arrangement 108. The thermostat 126 may ensure that the coolant supplied from the after-cooler 122 to the pump 114 is above a minimum predetermined temperature. Thus, the thermostat 126 may prevent the flow of the coolant at a low ambient temperature from the first circuit 110 to return to the second circuit 112 for the engine 102 in the low load condition. Also, the thermostat 126 may limit the exposure to overcooling for the components in the first circuit 110, especially the engine 102 and reduces the risk of the damage to the engine 102 in the marine power system 100.

Additionally, the first auxiliary thermostat 128 may ensure that the coolant supplied from the pump 114 to the after-cooler 122 is below a maximum predetermined temperature, sufficient to cool the charge air for the engine 102 in the after-cooler 122. Similarly, the second auxiliary thermostat 130 may ensure that the coolant supplied from the engine 102 to the pump 114 is again below a maximum predetermined temperature to be supplied to the second circuit 112 after mixing in the pump 114.

Consequently, the cooling arrangement 108 of the present disclosure with the triple thermostat configuration, in addition to regulating the flow of the coolant between the first and second circuits 110, 112, may enable the cooling arrangement 108 to work with a single pump 114. This is primarily made possible, as the thermostats 126, 128, 130 may regulate the flow of the coolant through the pump 114, for circulation of the coolant in both the first and the second circuits 110, 112 with varying temperature ranges, ensuring that the temperature of the coolant lies within a safe operating temperature range of the pump 114.

Further, the orifice 134 disposed in the bypass line 132 may act to control the flow rate of the coolant through the bypass line 132. The diameter of the orifice 134 may be calculated based on the specifications of the thermostat 126 and the needed flow rate through the bypass line 132, as determined to compensate for the transient load requirements of the engine 102. In an embodiment, the cooling arrangement 108 may include a variable orifice 134 for the bypass line 132.

In addition to controlling the flow rate of the coolant through the bypass line 132, the orifice 134 may also help in raising the temperature of the coolant flowing from the first circuit 110 to the second circuit 112. As the flow of the coolant may be restricted by the orifice 134, there may be a drop in velocity of the flow of the coolant. This may lead to the coolant in the bypass line 132, typically disposed near the after-cooler 122, to absorb some of the heat from the charge air at higher temperature in the after-cooler 122, as the coolant remains in close proximity to the after-cooler 122 for longer duration.

Thus, the cooling arrangement 108 of the present disclosure, with the thermostat 126 and the bypass line 132 including the orifice 134, may help to provide a constant bleed of the coolant and control the flow rate of the coolant between the first and the second circuits 110, 112. Thus, the cooling arrangement 108 may achieve the needed responsiveness to address the transient loading of the engine 102, thereby improving the efficiency of the marine power system 100, in general.

Although the embodiments of this disclosure as described herein may be incorporated without departing from the scope of the following claims, it will be apparent to those skilled in the art that various modifications and variations can be made. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.

Claims

1. A cooling arrangement comprising:

a first circuit;

a second circuit configured to be in fluid communication with the first circuit;

a coolant for circulating in the first circuit and the second circuit;

a pump configured to receive the coolant from the first circuit and the second circuit, the pump further configured to circulate the coolant back to the first circuit and the second circuit;

an after-cooler disposed in the first circuit of the cooling arrangement;

a thermostat disposed in connection with the after-cooler in the first circuit, the thermostat is configured to regulate the flow of the coolant from the after-cooler to the pump based on the temperature of the coolant from the after-cooler; and

a bypass line disposed in the first circuit parallel to the thermostat, the bypass line is configured to provide a constant bleed of the coolant in the cooling arrangement.

2. The cooling arrangement of claim 1, wherein the first circuit further includes a first auxiliary thermostat configured to regulate the flow of the coolant from the pump to the first circuit.

3. The cooling arrangement of claim 1, wherein the second circuit further includes a second auxiliary thermostat configured to regulate the flow of coolant from the second circuit to the pump.

4. The cooling arrangement of claim 1, wherein the first circuit is a low temperature circuit further including an after-cooler heat exchanger in connection with the after-cooler, the after-cooler heat exchanger configured to cool the coolant supplied to the after-cooler from the pump.

5. The cooling arrangement of claim 1, wherein the second circuit is a high temperature circuit in connection with an engine, the second circuit further includes a heat exchanger configured to cool the coolant supplied to the pump from the engine.

6. The cooling arrangement of claim 5, wherein the second circuit further includes a turbocharger configured to provide a charge air to the engine via the after-cooler.

7. The cooling arrangement of claim 1, wherein the bypass line further includes an orifice disposed within, the orifice is configured to control the flow of the coolant through the bypass line based on the diameter of the orifice.

8. The cooling arrangement of claim 7, wherein the orifice has the diameter of approximately 2-12 millimeters.

9. The cooling arrangement of claim 7, wherein the orifice has the diameter of approximately 5 millimeters.

10. A marine power system comprising:

an engine; and

a cooling arrangement configured to extract heat from the engine by a coolant, the cooling arrangement including: an after-cooler configured to cool a charge air for the engine by the coolant, a pump configured to receive the coolant from the after-cooler and the engine, and re-circulates the coolant back to the after-cooler and the engine, a thermostat disposed in connection with the after-cooler, the thermostat is configured to regulate a flow of the coolant from the after-cooler to the pump based on the temperature of the coolant from the after-cooler, a bypass line disposed in parallel to the thermostat, the bypass line is configured to provide a constant bleed of the coolant in the cooling arrangement, and an orifice disposed in the bypass line to control the flow of the coolant through the bypass line.

11. The marine power system of claim 10 further includes a turbocharger configured to provide the charge air to the engine via the after-cooler.

12. The marine power system of claim 10 further includes a heat exchanger configured to cool the coolant from the engine.

13. The marine power system of claim 10 further includes a first auxiliary thermostat configured to regulate the flow of coolant from the pump to the after-cooler.

14. The marine power system of claim 10 further includes a second auxiliary thermostat configured to regulate the flow of coolant from the engine to the pump.

15. The marine power system of claim 10, wherein the orifice is configured to control the flow of the coolant through the bypass line based on the diameter of the orifice.

16. The marine power system of claim 15, wherein the orifice has the diameter of approximately 2-12 millimeters.

17. The marine power system of claim 15, wherein the orifice has the diameter of approximately 5 millimeters.

18. A method for cooling an engine, the method comprising:

receiving a coolant from the engine to a pump;

pumping the coolant from the pump to an after-cooler;

regulating the flow of the coolant from the after-cooler to the pump, to be supplied back to the engine, by a thermostat; and

providing a bypass line in parallel to the thermostat to provide a constant bleed of the coolant from the after-cooler to the engine.

19. The method of claim 18, wherein regulating the flow of the coolant further includes allowing the coolant to flow through the thermostat based on the temperature of the coolant from the after-cooler.

20. The method of claim 18, wherein providing the bypass line further includes disposing an orifice within the bypass line to control the flow of the coolant through the bypass line.