Intelligent sea water cooling system
A sea water cooling system including a first fluid cooling loop coupled to a first side of a heat exchanger and to a thermal load, a second fluid cooling loop coupled to a second side of the heat exchanger and including a pump for circulating fluid through the second fluid cooling loop, and a controller operatively connected to the pump, wherein the controller is configured to monitor an actual temperature in the first fluid cooling loop and to adjust a speed of the pump based on the monitored temperature to achieve a predetermined temperature in the first fluid cooling loop. The system may be selectively operable in one of a plurality of operating modes, wherein in a first operating mode the pump operates based entirely on cooling demands of the thermal load, and in a second operating mode the pump operates to maintain a fluid pressure above a predefined pressure.
1. A method for equalizing pump usage in a variable flowrate cooling system having a plurality of pumps, comprising:
monitoring a total operating time for each pump; and
reallocating usage of the plurality of pumps so that one of said plurality of pumps having a relatively lower total operating time will be used more than another of said plurality of pumps having a relatively higher total operating time;
wherein reallocating usage of the pumps comprises reassigning a current primary pump of said plurality of pumps to operate as a back-up pump and reassigning a current back-up pump of said plurality of pumps to operate as a primary pump;
wherein the variable flowrate cooling system includes:
a first fluid cooling loop coupled to a first side of a heat exchanger and to a thermal load;
a second fluid cooling loop coupled to a second side of the heat exchanger and including the plurality of pumps for circulating fluid through the second fluid cooling loop; and
a controller operatively connected to the plurality of pumps, wherein the controller is configured to monitor an actual temperature in the first fluid cooling loop and to adjust a speed of the plurality of pumps based on the monitored temperature to achieve a predetermined temperature in the first fluid cooling loop; and
wherein the system is selectively operable in one of a plurality of operating modes, wherein in a first operating mode the plurality of pumps are operated to maintain a fluid pressure above a predefined pressure and in a second operating mode the plurality of pumps are operated to maintain a fluid pressure above a predefined pressure.
2. The method of claim 1 , wherein the reallocating usage of the pumps comprises an operator manually initiating one or more equalization commands by an operator interface of the system.
3. The method of claim 1 , wherein the reallocating usage of the pumps comprises automatically initiating equalization commands in response to the pumps accumulating a predefined amount of operating time.
4. The method of claim 1 , wherein the controller is a plurality of controllers, such that each controller is operatively connected to a respective one of said plurality of pumps.
5. The method of claim 1 , wherein the thermal load is a diesel engine.
6. The method of claim 1 , wherein the predefined pressure is an operator-defined minimum threshold pressure, the plurality of operating modes further comprising a third operating mode in which the pump is operated to maintain a fluid pressure above a predefined minimum pressure associated with an attached system.
7. The method of claim 1 , wherein the second fluid cooling loop comprises a once through seawater loop.
8. The method of claim 1 , wherein the first fluid cooling loop comprises a closed freshwater loop.
9. A method for operating a variable flowrate cooling system,
activating the system and selecting an operating mode;
driving pumps for flowing fluid through a heat exchanger, a first cooling loop including a thermal load and being coupled to a first side of the heat exchanger, and a second cooling loop including the pumps and being coupled to a second side of the heat exchanger;
monitoring a temperature of the first cooling loop, and comparing the monitored temperature to a predefined temperature range using controllers;
in response to the monitored temperature of the first cooling loop exceeding the predefined temperature range, driving the pumps at an increased speed for flowing the fluid faster through the second cooling loop; and
in response to the monitored temperature of the first cooling loop falling below the predefined temperature range, driving the pumps at a decreased speed for flowing the fluid slower through the second cooling loop;
wherein the system is selectively operable in one of a plurality of operating modes, wherein in a first operating mode the pumps are operated to maintain a fluid pressure above a predefined pressure and in a second operating mode the pumps are operated to maintain a fluid pressure above a predefined pressure;
wherein the thermal load is a diesel engine.
10. The method of claim 9 , further comprising driving the pumps at a minimum safe operating speed for maintaining a predetermined minimum system pressure.
11. The method of claim 9 , further comprising transmitting data between the controllers, wherein the data includes an operation status of the controllers and the pumps.
12. The method of claim 9 , wherein the first pump is driven by a variable frequency drive and operatively connected to the controller, such that the first controller controls operation of the variable frequency drive to regulate a flow of seawater to a heat exchanger.
13. The method of claim 9 , wherein in response to the monitored temperature of the first cooling loop exceeding the predefined temperature range, adjusting a valve position for adjusting an amount of fluid in the first cooling loop through the heat exchanger.
14. The method of claim 9 , wherein in response to the monitored temperature of the first cooling loop falling below the predefined temperature range, adjusting a valve position for diverting at least a portion of fluid in the first cooling loop through the heat exchanger.
15. The method of claim 10 , wherein in response to driving the pumps at a minimum safe operating speed, at least partially closing a discharge valve to maintain a minimum system charging pressure such that fluid in the second cooling loop is restricted without additional speed reduction of the pumps.
16. The method of claim 9 , wherein the second fluid cooling loop comprises a once through seawater loop.
17. The method of claim 9 , wherein the first fluid cooling loop comprises a closed freshwater loop.
18. A method for equalizing pump usage in a variable flowrate cooling system having a plurality of pumps, comprising:
monitoring a total operating time for each pump; and
reallocating usage of the plurality of pumps so that one of said plurality of pumps having a relatively lower total operating time will be used more than another of said plurality of pumps having a relatively higher total operating time,
wherein the system includes:
a first fluid cooling loop coupled to a first side of a heat exchanger and to a thermal load;
a second fluid cooling loop coupled to a second side of the heat exchanger and including the plurality of pumps for circulating fluid through the second fluid cooling loop; and
a controller operatively connected to the plurality of pumps, wherein the controller is configured to monitor an actual temperature in the first fluid cooling loop and to adjust a speed of the plurality of pumps based on the monitored temperature to achieve a predetermined temperature in the first fluid cooling loop;
wherein the system is selectively operable in one of a plurality of operating modes, wherein in a first operating mode the plurality of pumps are operated to maintain a fluid pressure above a predefined pressure and in a second operating mode the plurality of pumps are operated to maintain a fluid pressure above a predefined pressure.