阅读说明：本技术 智能海水冷却系统
(Intelligent seawater cooling system
) 是由 尹丹
S·沃纳
S·莱姆克 于 2015-08-03 设计创作，主要内容包括：一种适于减轻海水冷却回路中的盐结晶的海水冷却系统。所述系统可以包括：操作性地连接至冷却回路且配置成通过冷却回路泵送海水的泵,操作性地连接至冷却回路且配置成监测冷却回路中的海水温度的温度传感器,以及操作性地连接至温度传感器和泵的控制器,所述控制器配置成如果确定被监测的海水温度超过预定阈值温度则发布警告且增加泵的速度。(A seawater cooling system adapted to mitigate salt crystallization in a seawater cooling loop the system may include a pump operatively connected to the cooling loop and configured to pump seawater through the cooling loop, a temperature sensor operatively connected to the cooling loop and configured to monitor a temperature of the seawater in the cooling loop, and a controller operatively connected to the temperature sensor and the pump, the controller configured to issue an alert and increase a speed of the pump if it is determined that the monitored temperature of the seawater exceeds a predetermined threshold temperature.)
1, a seawater cooling system for monitoring and reducing clogging in a seawater cooling circuit, the system comprising:
a pressure sensor operatively connected to the cooling circuit and configured to measure a fluid pressure of the seawater in the cooling circuit;
a plurality of valves operatively connected to the cooling circuit and configured to selectively change a flow direction of seawater through the cooling circuit between an th direction during normal operation and a second direction opposite the th direction during backwash operation, and
a controller operatively connected to the pressure sensor and the plurality of valves, the controller configured to operate the plurality of valves to change flow from the th direction to a second direction when the pressure of the seawater exceeds a pressure level associated with a predetermined maximum blockage level.
2. The seawater cooling system of claim 1, wherein the controller is configured to operate the plurality of valves based on manual user input.
3. The seawater cooling system of claim 1, wherein the controller is configured to maintain a flow direction of the seawater through the cooling circuit in the second direction for a predetermined period of time.
4. The seawater cooling system of claim 3, wherein the controller is configured to adjust the positions of the plurality of valves after a predetermined period of time has elapsed such that the flow direction of the seawater through the cooling circuit is configured in the th direction.
5. The seawater cooling system of claim 1, wherein the pressure level associated with the predetermined maximum blockage level is a predetermined value above an initial system resistance pressure level.
6, a method for monitoring and reducing plugging in a seawater cooling circuit, the method comprising:
circulating seawater through the cooling loop using a pump operating at a predetermined speed;
measuring the pressure of the seawater while the pump is operating at the predetermined speed;
comparing the measured pressure to a predetermined pressure, the predetermined pressure associated with a baseline condition of the cooling circuit; and
when the measured pressure exceeds the predetermined pressure by a predetermined amount, the circulation direction of the seawater through the cooling circuit is reversed.
7. The method of claim 6, wherein the baseline condition is a condition of the cooling circuit at a new installation or after system maintenance.
8. The method of claim 6, wherein the circulation direction of the seawater is reversed for a predetermined amount of time.
9. The method of claim 8, wherein the circulation direction of the seawater is returned to the initial flow direction after the predetermined amount of time has elapsed.
10. The method of claim 6, wherein the direction of circulation of the seawater is automatically reversed without user intervention.
11, an overlap pump system, comprising:
a th pump and a second pump coupled to the seawater cooling circuit for circulating seawater through the seawater cooling circuit, and
a controller and a second controller operatively coupled to the th pump and the second pump, respectively, and
the th controller and the second controller are configured to perform a handshake operation for switching operation between the th pump and the second pump, the handshake operation including:
a request is sent from the th controller to the second controller requesting the second controller to begin operation of the second pump,
upon receiving the request, sending an acknowledgement from the second controller to the th controller when the second pump is capable of beginning operation, an
Upon receiving the acknowledgement at the th controller, the th controller turns off the th pump.
12. The system of claim 11, the handshake operation further comprising;
if the th controller does not receive an acknowledgement from the second controller within a predetermined period of time after sending the request, operation of the th pump is maintained.
13. The system of claim 11 wherein the handshaking operation includes the th controller operating the th pump at the current speed for a predetermined period of time after receiving an acknowledgement from the second controller.
14. The system of claim 11 wherein the handshaking operation includes the th controller decreasing the speed of the th pump after receiving the acknowledgement from the second controller, and the second controller increasing the speed of the second pump after sending the acknowledgement.
15, a method for overlapping operation of a pump and a second pump, the method comprising:
sending a request from a controller coupled to the th pump to a second controller coupled to the second pump requesting the second controller to begin operation of the second pump;
upon receiving the request, sending an acknowledgement from the second controller to the th controller when the second pump can begin operation, and
upon receiving the confirmation at the th controller, the th pump is turned off.
16. The method of claim 15, further comprising maintaining operation of the pump if the controller does not receive an acknowledgement from the second controller within a predetermined period of time after sending the request.
17. The system of claim 15 wherein the th controller operates the th pump at the current speed for a predetermined period of time after receiving the acknowledgement from the second controller.
18. The system of claim 15 wherein the controller decreases the speed of the pump after receiving the acknowledgement from the second controller and the second controller increases the speed of the second pump after sending the acknowledgement.
Technical Field
The present application relates generally to the field of seawater cooling systems, and more particularly to systems and methods for controlling temperature in a fresh water cooling circuit by adjusting pump speed in a seawater cooling circuit thermally coupled to the fresh water cooling circuit.
Background
Large marine vessels are typically powered by large internal combustion engines that require continuous cooling under various operating conditions, such as during high speed cruising, low speed operation near ports, and full speed operation to avoid inclement weather existing systems for achieving such cooling typically include or more pumps that draw seawater into onboard heat exchangers used to cool closed fresh water cooling circuits that flow through and cool the vessel's engines ( or more) and/or other various loads on the vessel (e.g., air conditioning systems).
The cooling system will in this case be configured to divert of the fresh water circuit all the cooling power provided by the seawater pump driven at constant speed (and thus required to divert water into the fresh water circuit) directly to the discharge side of the heat exchanger, where it mixes with the remaining fresh water flowing through and cooled by the heat exchanger.
Disclosure of Invention
A seawater cooling system for mitigating salt crystallization in a seawater cooling circuit is disclosed . the system can include a pump operatively connected to the cooling circuit and configured to pump seawater through the cooling circuit.
A method for mitigating salt crystallization in a seawater cooling loop can include measuring a temperature of seawater in the cooling loop, comparing the measured seawater temperature to a predetermined threshold temperature, and increasing a speed of a pump circulating the seawater through the cooling loop when the measured seawater temperature exceeds the predetermined threshold temperature.
A controller may be operatively connected to the pressure sensor and the plurality of valves, the controller configured to operate the plurality of valves to change the flow from the th direction to the second direction when the pressure of the seawater exceeds a pressure level associated with a predetermined maximum blockage level.
A method for monitoring and reducing blockages in a seawater cooling circuit is disclosed that can include circulating seawater through the cooling circuit with a pump operating at a predetermined speed, measuring a pressure of the seawater while the pump is operating at the predetermined speed, comparing the measured pressure to a predetermined pressure, the predetermined pressure being associated with a baseline condition of the cooling circuit, and reversing a direction of circulation of the seawater through the cooling circuit when the measured pressure exceeds the predetermined pressure by a predetermined amount.
A th controller and the second controller may be configured to perform a handshake operation for a switching operation between the th pump and the second pump, the handshake operation may include sending a request from the th controller to the second controller requesting the second controller to begin operation of the second pump, upon receiving the request, sending an acknowledgement from the second controller to the th controller when the second pump is capable of beginning operation, and upon receiving the acknowledgement at the th controller, the th controller shutting off the th pump.
A method for overlapping operation of a pump and a second pump is disclosed that may include sending a request from a controller coupled to a pump to a second controller coupled to the second pump requesting the second controller to begin operation of the second pump, sending an acknowledgement from the second controller to a controller when the second pump is capable of beginning operation upon receipt of the request, and shutting down an pump upon receipt of the acknowledgement at a controller.
Drawings
Specific embodiments of the disclosed apparatus will now be described, by way of example, with reference to the accompanying drawings, in which:
fig. 1 is a schematic diagram illustrating an exemplary intelligent seawater cooling system according to the system.
Fig. 2 is a flow chart illustrating an exemplary method for operating the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Fig. 3 is a flow chart illustrating an exemplary method for establishing parameters in the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Fig. 4 is a flow chart illustrating an exemplary method for equalization pump usage in the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Fig. 5 is a graph illustrating energy saving due to a reduction in pump speed.
Fig. 6 is a graph illustrating an exemplary means for determining whether to operate the system of the present application with 1 pump or 2 pumps.
Fig. 7 is a flow diagram illustrating an exemplary method for mitigating salt crystallization in the seawater cooling loop of the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Fig. 8 is a flow chart illustrating an exemplary method for monitoring and reducing plugging in the seawater cooling circuit of the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Fig. 9 is a flow chart illustrating an exemplary method for overlapping the operation of the th pump and the second pump in the intelligent seawater cooling system illustrated in fig. 1 in accordance with the present application.
Detailed Description
The intelligent seawater cooling system and method according to the present application will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the system and method are shown. The disclosed systems and methods may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbering represents like elements throughout.
Referring to FIG. 1, a schematic diagram of an exemplary intelligent seawater cooling system 10 (hereinafter "system 10") is shown, the system 10 may be mounted on any type of marine vessel or offshore platform having or more engines 11 requiring cooling, although only a single engine 11 is shown in FIG. 1, it should be understood by one of ordinary skill in the art that the engine 11 may represent multiple engines or various other loads that may be coupled to the vessel or platform of the cooling system 10.
The system 10 may include a seawater cooling loop 12 and a freshwater cooling loop 14, the seawater cooling loop 12 and the freshwater cooling loop 14 being interconnected by a heat exchanger 15, as described further below, although only a single heat exchanger 15 is shown in fig. 1, it is contemplated that the system 10 may alternatively include more than two heat exchangers for providing greater heat transfer between the seawater cooling loop 12 and the freshwater cooling loop 14 without departing from the present application.
The seawater cooling loop 12 of the system 10 may include a primary pump 16, a secondary pump 18, and a backup pump 20. The pumps 16-20 may be driven by respective variable frequency drives 22, 24, and 26 (hereinafter " VFDs 22, 24, and 26"). While the pumps 16-20 may be centrifugal pumps, it is contemplated that the system 10 may alternatively or additionally include various other types of pumps including, but not limited to, gear pumps, progressive cavity pumps, or multi-axis screw pumps, or other positive displacement or other non-positive displacement pumps.
The VFDs 22-26 may be operatively connected to respective primary, secondary and backup controllers 28, 30 and 32 via communication lines 40, 42 and 44 various sensors and monitoring devices 35, 37 and 39 may be operatively mounted on the pumps 16, 18 and 20 and connected to the respective controllers 28, 30 and 32 via communication lines 34, 36 and 38, the sensors and monitoring devices 35, 37 and 39 including, but not limited to, vibration sensors, pressure sensors, bearing temperature sensors, leakage sensors and possibly other sensors, which sensors may be provided for monitoring the health of the pumps 16, 18 and 20, as further described in below.
The controllers 28-32 may further be interconnected by a communication line 46 the communication line 46 may be transparent to other networks that provide supervisory communication capabilities the controllers 28-32 may be configured to control the operation of the VFDs 22-26 (and thus the pumps 16-20) to regulate the flow of seawater to the heat exchanger 15 as described further the controllers 28-32 may be any suitable type of controller including, but not limited to, Proportional Integral Derivative (PID) controllers and/or Programmable Logic Controllers (PLCs). the controllers 28-32 may include corresponding memory units and processors (not shown) that may be configured to receive and store data provided by various sensors in the cooling system 10, to transfer data between the controllers and the network external to the system 10, and to store and execute software instructions for performing the method steps of the present application as described below.
The controller 28, VFD 22, or other user interface may be configured to automatically determine the type of pump connected in the system 10 and load the corresponding set of parameters without any operator input, as well as the control system may be configured to automatically determine the type of pump connected in the system 10 and load the corresponding set of parameters.
The operator may also establish a number of system parameters at the controller 28, the VFD 22, or other user interface. These parameters may include, but are not limited to, fresh water temperature range, VFD motor speed range, minimum pressure level, fresh water flow, hydrothermal capacity coefficient, heat exchanger surface area, heat transfer coefficient, presence of three-way valve, and ambient temperature limit.
The pump parameters and system parameters established at the controller 28 or the VFD 22 may be copied to the other controllers 30 and 32 and/or other VFDs 24 and 26, such as by transmission of corresponding data via the communication line 46. this copying of parameters may be performed automatically or upon entry of appropriate commands by an operator at the controller 28, VFD 22, or other user interface.
The communication lines 34-46 and the communication lines 81, 104 and 108 described below are illustrated as hard-wired connections. However, it should be understood that the communication lines 34-46, 91, 104 and 108 of the system 10 may be embodied by various wireless or hardwired connections. For example, communication lines 34-46, 91, 104, and 108 may be implemented using: Wi-Fi, Bluetooth, the Public Switched Telephone Network (PSTN), a satellite network system, a cellular network (such as, for example, the Global System for Mobile communications (GSM) for SMS and packet voice communications), the General Packet Radio Service (GPRS) for encapsulating data and voice communications, or a wired data network (such as the Ethernet/Internet for TCP/IP, VOIP communications), etc.
The seawater cooling circuit 12 may include various piping and piping system components ("pipes") 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 69, 70, 109, 110, 111, 112, 113, 114 for drawing water from the ocean 72 via pumps 16-20 and circulating seawater through the seawater cooling circuit 12 on the seawater side including heat exchangers 15, as described below in step the pipes 50-70 and 109 and the pipes 84, 86, 88, 90, 92, 94, 95, 97, 99, and 101 and the additional systems 103, 105, and 107 of the freshwater cooling circuit 14 described below may be any type of rigid or flexible conduit, pipe, tube, or pipe suitable for transporting seawater, and may be disposed on a vessel or platform in any configuration that may be suitable for a particular application.
The seawater cooling loop 12 may further include a discharge valve 89 disposed intermediate the conduits 69 and 70 and connected to the primary controller 28 via a communication line 91 it is contemplated that the discharge valve 89 may also be connected to the secondary controller 30 and/or the backup controller 32 as these controllers may automatically identify the connected discharge valve 89 and may automatically distribute information regarding the connection of the discharge valves 89 to each other via the communication line 46 the discharge valve 89 may be adjustably opened and closed to change the operating characteristics (e.g., pressure) of the pumps 16-20 as described in the further step below the discharge valve 89 is a throttle in non-limiting exemplary embodiments.
The seawater cooling loop 12 may further include flow control valves 115, 116, 117, 118 disposed intermediate the conduits 66 and 109, 110 and 68, 111 and 112, 113 and 114, respectively, the flow control valves 115 and 118 may be connected to the primary controller 28 via communication line 91 (as shown in FIG. 1) and/or via or more additional communication lines for controlling the operation of those valves it is contemplated that the flow control valves 115 and 118 may also be connected to the secondary controller 30 and/or the backup controller 32 as these controllers may automatically identify the connected discharge valves 89 and may automatically distribute information regarding the connection of the discharge valves 89 to each other via communication line 46. the flow control valves 115 and 118 may be selectively opened and closed to change the direction in which seawater is circulated through the heat exchanger 15. specifically, during normal operation of the system 10, the flow control valves 115 and 116 may be opened and the flow control valves 117 and 118 may be closed so that seawater is circulated through the heat exchanger 15 in the direction for cooling the fresh water in the fresh water cooling loop 14, as described below in step .
During a backwash operation, the flow regulating valves 115, 116 may be closed and the flow regulating valves 117, 118 may be opened to circulate seawater through the heat exchanger 15 in a second direction opposite the th direction to backwash and clean the heat exchanger 15, as will be described further below with respect to FIG. 8 .
The seawater cooling loop 12 may further include a resistance temperature detector 119 (hereinafter "RTD 119") or other temperature measuring device operatively connected to the discharge side of the heat exchanger 15, such as at a location upstream of the discharge valve 89 intermediate the conduits 68 and 69. the RTD 119 may be connected to the main controller 28 via communication line 91 and/or via or more additional communication lines it is contemplated that the RTD 119 may also be connected to the secondary controller 30 and/or the backup controller 32 as these controllers may automatically identify the connected RTD 119 and may automatically distribute information regarding the connection of the RTDs 119 to each other via communication line 46. the RTD 119 may be used to monitor the seawater temperature in the seawater cooling loop 12, such as to determine if the seawater is approaching a temperature at which salt may crystallize in the seawater.
The fresh water cooling circuit 14 of the system 10 may be a closed fluid circuit including a fluid pump 80 and various conduits and components 84, 86, 88, 90, 92, and 94 for continuously pumping and transporting fresh water through the heat exchanger 15 and the engine 11 to cool the engine 11, as described in step below, the fresh water cooling circuit 14 may further include a three-way valve 102, the three-way valve 102 being connected to the main controller 28 via a communication line 104 to controllably bypass the heat exchanger 15 with a prescribed amount of water in the fresh water cooling circuit 14, as described in step below.
The temperature in the fresh water cooling loop 14 may be measured and monitored by the main controller to facilitate various control operations of the cooling system 10. Such temperature measurement may be performed by a resistance temperature detector 106 (hereinafter "RTD 106") or other temperature measurement device operatively connected to the fresh water cooling circuit 14. Although RTD106 is illustrated in fig. 1 as measuring the temperature of fresh water cooling circuit 14 on the inlet side of engine 11, it is contemplated that RTD106 may alternatively or additionally measure the temperature of fresh water cooling circuit 14 on the outlet side of engine 11. RTD106 may be connected to host controller 28 via communication line 108 or, alternatively, RTD106 may be an integrated onboard component of host controller 28. It is contemplated that RTD106 may also be connected to secondary controller 30 and/or backup controller 32 because these controllers may automatically identify connected RTD106 and may automatically distribute information regarding the connection of RTD106 to each other via communication lines 46.
For example, seawater from the seawater cooling loop 12 may be provided to or more of the fire suppression system 103, the ballast control system 105, and/or the seawater diversion system 107 on an as-needed basis.
In the exemplary system 10 illustrated in fig. 1, seawater may be provided to the system 103 and 107 via conduits 95, 97, 99, and 101, which may be connected to the seawater cooling loop 12 at, for example, conduit 66. The conduits 95-101 may be provided with various manual or automatic control valves (not shown) for introducing the flow of seawater into the system 103 and 107 in a desired manner. Of course, it will be appreciated that if seawater is supplied to the system 103 and 107, the flow of seawater through the heat exchanger 15 will be reduced, which may cause the temperature in the fresh water cooling loop 14 to rise unless the operation of the pumps 16-20 is modified. Thus, the pumps 16-20 may be controlled in the manner of the seawater used by the compensation system 103 and 107, as will be described in more detail below.
It is contemplated that system 10 may monitor the total amount of time each of pumps 16-20 has been operating and may redistribute operation of pumps 16-20 in a manner that equalizes or attempts to equalize the operating time of pumps 16-20. for example, if primary pump 16 has recorded 100 hours of operation, secondary pump 18 has recorded 50 hours of operation, and the backup pump has recorded only 5 hours of operation, system 10 may redistribute primary pump 16 to operate as a backup pump and may redistribute backup pump 20 to operate as a primary pump.
The equalization procedure described above may be performed automatically, such as according to a predetermined schedule, for example, when of pumps 16-20 have accumulated a predetermined (e.g., operator defined) amount of operating time since the last reassignment, the equalization procedure may be performed and the roles of pumps 16-20 may be reassigned as needed for equalization use.
The system 10 may be operated in a number of different operator selectable modes, such as modes that may be selected via an operator interface (not shown), wherein each operating mode may indicate a specific minimum system pressure to be maintained by the system 10. for example, the operating mode may be a "no threshold" or similar specific mode that, if selected, will cause the system 10 to operate the pumps 16-20 without regard to any predetermined or specified minimum system pressure. in other words, the system 10 will operate the pumps 16-20 based solely on the cooling demand of the engine 11. for example, if any seawater operating system (e.g., the ballast control system 105) draws seawater from the seawater cooling circuit 12, the flow of seawater through the heat exchanger 15 will be reduced, thereby reducing the amount of cooling in the primary control cooling circuit 14. accordingly, the water temperature in the fresh water cooling circuit 14 may increase.
The second optional operating mode may be a "minimum threshold" or similar designated mode that, if selected, may allow an operator to manually input the minimum threshold and thereafter cause the system 10 to operate the pumps 16-20 in a manner that maintains the system pressure of the vessel above a manually specified threshold, the minimum threshold may be a value below the minimum system pressure (described above), but this provides some constant maintenance amount of seawater pressure in the vessel's system pressure may be monitored by a sensor that is integral with the vessel and independent of the system 10, and may be communicated to the system 10 via a communication line such as communication line 46.
A third selectable operating mode may be a "minimum system pressure" or similar designated mode that, if selected, will cause the system 10 to operate the pumps 16-20 in a manner that will maintain the system pressure of the vessel above a predetermined (e.g., pre-calculated) minimum system pressure for the vessel.
It will be appreciated that the above-described modes of operation provide flexibility to the system 10 to adapt to various system operator preferences without having to reconfigure system components prior to installation. Additionally, if the operator's preferences change over time, such as if the operator begins to hesitate to operate the system 10 at a pressure less than the minimum system pressure, the operator may seamlessly switch between operating modes and gradually transition to pure on-demand operation as his/her level of habit increases.
Referring to FIG. 2, a flow diagram of an -like exemplary method for operating the system 10 according to the present application will be described in connection with the schematic diagram of the system 10 shown in FIG. 1 unless otherwise indicated, the described method may be performed in whole or in part by the controllers 28-32, such as by executing various software algorithms with their processors.
In step 200, the system 10 may be activated, such as by an operator making an appropriate selection in an operator interface (not shown) of the system 10. when activated, the operator may be prompted to select an operating mode that may indicate a minimum system pressure to be maintained by the system 10. for example, the operator may be prompted to select of the "no threshold", "minimum threshold", or "minimum system pressure" operating modes described above.
once the system 10 has been activated and the mode of operation has been designated, the primary and secondary controllers 28 and 30 may command the VFDs 22 and 24 to begin driving at least of the pumps 16 and 18 in step 210 of the exemplary method so that the pumps 16 and 18 may begin drawing seawater from the ocean 72, passing it through the conduits 52 and 54, the pumps 16 and 18, the conduits 58-66, the heat exchanger 15, and finally back to the ocean 72 through the conduits 68 and 70. when seawater flows through the heat exchanger 15, it may cool the fresh water in the fresh water cooling circuit 14, which also flows through the heat exchanger 15. thereafter, the cooled fresh water flows through the engine 11 and cools the engine 11.
In step 220 of the exemplary method, main controller 28 may monitor the temperature of the fresh water in fresh water cooling loop 14 via RTD 106. Thus, the main controller 28 may determine whether the fresh water is at a temperature required to provide adequate cooling for the engine 11, such as by comparing the monitored temperature to a predetermined temperature level and a predetermined temperature range. For example, the desired temperature level of the fresh water at the discharge of the heat exchanger may be 35 degrees Celsius, and the predetermined temperature may range from +/-3 degrees Celsius.
If the primary controller 28 determines in step 220 that the monitored temperature of the fresh water exceeds or is about to exceed the predetermined temperature level, the primary controller 28 may increase the speed of the VFD 22 and may issue a command to the secondary controller 30 to, for example, increase the speed of the VFD 24 to the speed of the VFD 22 in step 230 of the exemplary method. Thus, the corresponding primary pump 16 and/or secondary pump 18 are driven faster and the flow of seawater through the seawater cooling loop 12 is increased. Thereby, a greater cooling is provided at the heat exchanger 15 and thus the temperature in the fresh water cooling circuit 14 is reduced.
Conversely, if the main controller 28 determines in step 220 that the monitored fresh water temperature is below or is about to be below the predetermined temperature level, then in step 240 of the exemplary method the main controller 28 may reduce the speed of the VFD 22 and may issue a command to the secondary controller 30 to, for example, reduce the speed of the VFD 24 to the speed of the VFD 22. accordingly, drive the corresponding primary and secondary pumps 16, 18 more slowly, reducing the flow of seawater through the seawater cooling loop 12. accordingly, less cooling is provided at the heat exchanger 15, and thus the temperature in the fresh water cooling loop 14 is increased. in some cases, such as if the fresh water temperature is still too low (e.g., lower than the desired temperature level or lower than a predetermined temperature range) and the pump speed cannot be reduced further by due to a requirement to maintain a minimum system pressure and/or minimum pump speed, the main controller 28 may additionally direct the three-way valve 102 to adjust its position, thereby diverting some or all of the fresh water in the fresh water cooling loop 14 to bypass the heat exchanger 15 so as to further reduce the cooling of the fresh water.
Regardless of how little cooling may be required by the engine 11, if the "minimum threshold" mode or the "minimum system pressure" mode is selected in step 200 above, both pumps 16 and 18 will be driven at a speed that does not allow the system pressure of the vessel being monitored to be below the predetermined minimum system pressure or the specified minimum threshold (described above), respectively. Thus, a certain minimum level of seawater pressure may be maintained throughout the system of the vessel for supplying seawater to the seawater operating system.
If the "no threshold" mode is selected in step 200, the system 10 will not operate according to any predetermined or specified minimum system pressure, but will then operate as described above only in response to the cooling requirements of the engine 11 to ensure that a sufficient amount of seawater is pumped in an as-needed manner to provide engine cooling and to supply the seawater operating system.
In some cases, such as if the system 10 is operating in specially cooled water and/or if the engine 11 is idling, it may be desirable to reduce the flow of seawater in the seawater cooling circuit 12 below that which can be achieved by reducing the pump speed while maintaining steady operation of the pumps 16 and 18. in other words, regardless of how much flow is required in the seawater cooling circuit 12, it may be necessary to operate the pumps 16 and 18 at a minimum safe operating speed to avoid, for example, cavitation or damage to the pumps 16 and 18. if the main controller 28 determines that such a low flow rate of seawater is desirable, then the main controller 28 may reduce the speed of the VFD 22 to drive the main pump 16 at or near the minimum safe operating speed, may command the speed of the VFD 24 to drive (or shut off) the secondary pump 18 at or near the minimum safe operating speed in step 250, and may command the partial closure of the bleed valve 89 to maintain the required minimum system bleed pressure, thus, by partial closure of the bleed valve 89, may command the bleed valve 89 to operate at or near the minimum safe operating speed to drive (or shut off) the secondary pump 18, and may command the pressure of the system 18 to maintain the required pressure in a minimum safe operating speed or pressure reduction mode, i.e., may command the flow rate of the system 18 to maintain the desired pressure in a high pressure reduction mode, i.e., a minimum pressure reduction mode designated as the system pressure in step 3589, and a minimum pressure restriction of the system 18, and a minimum pressure in a designated mode, and a designated as a designated sea cooling mode, and a designated sea cooling mode, may be achieved in which may be achieved in a high pressure, or a high pressure, and a designated sea cooling mode, a designated sea cooling circuit.
By continuously monitoring the temperature in the fresh water cooling circuit 14 and adjusting the pump speed and flow in the seawater cooling circuit 12 in the manner described above, the pumps 16 and 18 may be driven only as fast as needed to provide the amount of cooling needed at the heat exchanger 15 and/or to maintain a predetermined or specified minimum system pressure. Thus, significant energy savings may be realized when the disclosed system 10 operates at a lower Q due to lower cooling demands from the engine, rather than running the pump at maximum speed and simply diverting excess flow away or through a recirculation loop. For example, if Q is the rated seawater flow Q opt50% of their rated speed, then pumps 16, 18 need only operate at 50% of their rated speed to provide Q opt50% of the total. This reduction in speed results in an 87.5% reduction in power "P" as compared to prior art systems that operate the pumps 16, 18 at a constant maximum speed (or rated speed).
In step 260 of the exemplary method, the main controller 28 may determine whether the system 10 should operate in 1-pump mode or 2-pump mode in order to achieve the desired efficiency and more energy savings.in other words, it may be more efficient in some circumstances (e.g., if minimal cooling is required) to drive only of the pumps 16 or 18 and not the other pumpsoptThis can result in a more efficient system. For example, if the system 10 is operating in the 2-pump mode and both pumps 16 and 18 are driven at less than a predetermined efficiency point, the main controller 28 may deactivate the secondary pump 18 and operate only the primary pump 16. Efficiency Q/Q while the 1-pump is runningoptWill increase, resulting in a more efficient system than 2-pump operation. Conversely, if the system 10 is operating in a 1-pump mode of operation (e.g., running only the primary pump 16) and the primary pump 16 is being driven at greater than a predetermined efficiency point, the primary controller 28 may activate the secondary pump 18.
As shown in FIG. 6, the switch point (between and two pump operations) may be based on the optimal flow range "QoptThe "actual flow rate of system 10 compared" Q ". According to an exemplary curve, Q/Q when operating with a single pumpoptAbove 127%, the system may switch to two pump operation to achieve the most efficient operation. Likewise, Q/Q when operating with two pumpsoptFalling below 74%, the system may switch to single pump operation. At the same time, the discharge valve is controlled so as to always maintain the required minimum system discharge pressure.
In step 270 of the exemplary method, the primary, secondary and backup controllers 28, 30, 32 may periodically transmit data packets to each other, such as via the communication lines 46, which may include information regarding the critical operating status or "health" of the various controllers 28-32, including the respective pumps 16-20 and VFDs 22-26. if it is determined that of the controllers 28-32 or their corresponding pumps have stopped operating properly or are tending to indicate a direction of a near or far fault, or if their communication lines have failed or are inactive, the roles of the controllers may be reassigned to another controllers.
Referring to FIG. 3, a flow chart illustrating an exemplary method for inputting operating parameters into the system 10 in accordance with the present application is illustrated.
In step 300 of the exemplary method, the operator may establish a plurality of pump parameters at the controller 28, the VFD 22, or other user interface, as described above, which may include, but are not limited to, a reference speed, a reference efficiency, a reference flow rate, a reference head, a reference pressure, a speed limit, a suction pressure limit, a discharge pressure limit, a bearing temperature limit, and a vibration limit.
In step 320 of the exemplary method, the operator may establish a plurality of system parameters at the controller 28, the VFD 22, or other user interface. These parameters may include, but are not limited to, fresh water temperature ranges, VFD motor speed ranges, minimum pressure levels, fresh water flow, hydrothermal capacity coefficients, heat exchanger surface area, heat transfer coefficients, presence of three-way valves, and ambient temperature limits.
In step 330 of the exemplary method, the pump parameters and system parameters established in the previous steps may be copied to the other controllers 30 and 32 and/or other VFDs 24 and 26, such as via transmission of corresponding data over the communication line 46.
Referring to FIG. 4, a flow chart illustrating an exemplary method for use of the pumps 16-20 of the equalization system 10 according to the present application is shown.
In step 400 of the exemplary method, the system 10 may monitor the total amount of time that each of the pumps 16-20 has operated, in step 410, the system 10 may determine whether of the pumps 16-20 has operated for longer than a specified amount of time of at least of the other pumps 16-20, in step 420, the system 10 may redistribute operation of the pumps 16-20 in a manner that balances or attempts to balance the operating time of the pumps 16-20. for example, if the primary pump 16 has recorded 100 hours of operation, the secondary pump 18 has recorded 50 hours of operation, and the backup pump has recorded only 5 hours of operation, the system 10 may redistribute the primary pump 16 to operate as a backup pump and may redistribute the backup pump 20 to operate as a primary pump, thus, the pumps 16 and 20 may continue to accumulate effective operating time while the pumps 16 remain substantially idle, thus, by balancing the operating time of the pumps 16-20, the pumps 16-20 may be caused to wear at a basic system rate and may thus be repaired or replaced according to the schedule.
For example, when of pumps 16-20 have accumulated a predetermined (e.g., operator defined) amount of operating time since the last reassignment, the equalization procedure may be executed and the roles of pumps 16-20 may be reassigned as needed for equalization use.
With reference now to FIG. 7, methods for mitigating salt crystal formation within the cooling system will be described.
In summary, a temperature sensor (such as RTD 119, see FIG. 1) can be installed at the sea water discharge of the heat exchanger 15 to enable the sea water temperature to be monitored by of the networked controllers 28, 30, 32. in embodiments, this information can be shared among the controllers in the network. an alarm set point can be provided by the system operator so that if the sea water temperature rises below the alarm set point by a specified amount (e.g., 5 degrees Celsius), an alarm will be issued and all operating pumps 16, 18, 20 in the system will operate at a rated speed to reduce the sea water temperature to prevent salt crystallization. in embodiments, this feature will override the conventional fresh water temperature regulation strategy.
, the system enters this "sea temperature lowering mode" and after that the sea temperature falls below a warning level (e.g., 5 ℃ below the alarm set point), the system will return to "normal" operation where fresh water temperature regulation and minimum system pressure regulation determine the operating speed of the pumps 16, 18, 20.
The described "sea water temperature reduction mode" helps to automatically prevent sea salt crystallization and accumulation in the cooling system components it enables a single temperature input to be monitored and shared with the networked pumps 16, 28, 20 the action of the pumps is not personalized, but rather reacts as an system.
Fig. 7 is a flow chart illustrating a non-limiting exemplary method for monitoring seawater temperature and preventing salt crystallization in the seawater cooling loop 12 of the system 10.
In step 700, the operator may enter an alarm temperature at the controller 28, the VFD 22, or other user interface. The alarm temperature may be a temperature at which salt may crystallize in the seawater cooling loop 12 and may thus clog the system 10.
If it is determined that the measured seawater temperature exceeds some predetermined threshold temperature, i.e., is less than an alarm temperature (e.g., 5 degrees celsius below the alarm temperature) but does not exceed the alarm temperature, then the system 10 may issue a warning in step 720 to notify the system operator ( or more) of this condition, and may further direct any active pumps 16-20 to operate at their maximum rated speed regardless of the cooling demand of the engine 11 to reduce the seawater temperature in the seawater cooling circuit 12 and thereby prevent or mitigate salt crystallization and plugging.
It will be appreciated that since the active pumps 16-20 are operating at their rated speed to cool the seawater to a temperature that prevents or mitigates salt crystallization, the fresh water in the fresh water cooling circuit 14 may be cooled to a temperature below that required to maintain the engine 11 at the required safe operating temperature in which case the main controller 28 may additionally command the three-way valve 102 to adjust its position to divert some or all of the in the fresh water cooling circuit 14, thereby bypassing the heat exchanger 15 to further reduce the cooling of the fresh water .
After the temperature of the seawater in the seawater cooling loop 12 falls below the threshold temperature, the system 10 may return to normal operation in step 740, wherein the pumps 16-20 are partially or wholly driven in response to the cooling demand of the engine 11 in the manner previously described. Thus, the exemplary method set forth in fig. 7 utilizes only a single temperature input in the seawater cooling loop 12 to assist in automatically mitigating or preventing salt crystallization and resultant plugging within the system 10.
Referring now to FIG. 8, methods will be described for mitigating plugging of the heat exchanger 15 and related components.
After this, the cooling system can be monitored periodically for clogging resistance ("clogging level") through the use of a user configurable schedule or through manual operations on demand. During such monitoring, all pumps in the network may operate at the same speed for a predetermined amount of time as they did during the initial set up operation (described above), and the system pressure may be recorded into the controllers 28, 30, and 32. The recorded system pressure may then be compared to the initial system resistance level recorded during the initial set operation. If the system pressure exceeds a cooler blockage warning/alarm level, a warning/alarm can be activated, alerting the user to clean the cooling system with an automatic backwash process or by manual backwash as needed.
It is contemplated that the measured initial occlusion level may be manually modified by the operator at for a quantified time after the set operation described above, such as may be desired for various reasons.
In embodiments, the system can automatically initiate a predetermined backwash operation by opening/closing appropriate valves to direct flow through the heat exchanger 15 in a reverse direction (as compared to a normal operation cooling flow) to flush the system when the current system clogging level reaches or exceeds a warning or alarm clogging level.
If the current blockage level does not decrease by a sufficient amount after th attempts at backwash, or several more backwash operations can be performed to reduce the current blockage level to the desired value.
The disclosed configuration provides fully automatic monitoring of the blockage level of the cooling system. With integrated backwash operations, cooling system cleaning maintenance can be reduced to a minimum (i.e., to a point when the cooling system does require user attention). This is advantageous in comparison to prior systems where the backwash operation is performed periodically and/or automatically when the vessel is in port, which can result in unnecessary cleaning or undesirably delayed cleaning.
FIG. 8 is a flow chart illustrating an exemplary method for monitoring the cooler blockage level of the system 10. The method may be employed to determine the extent to which the seawater cooling loop 12 of the system 10 has become clogged (e.g., due to salt, debris, biological organisms, etc.) relative to conventional operation. The measured occlusion level may then be used to determine whether manual and/or automatic steps should be taken to alleviate or remedy the occlusion.
In step 800, an initial resistance level or "initial blockage level" of the system 10 may be determined, such as by running all of the pumps 16-20 in the system 10 at their rated speeds and measuring the system pressure in the seawater cooling loop 12 with a system pressure sensor.
In step 820, the main controller 28 may determine a maximum plugging level using the initial plugging level.
In step 830, a blockage level test may be performed hours after the initial blockage level of the system 10 is measured to determine a contemporaneous blockage level of the system 10.
If it is determined that the contemporaneous blockage level exceeds the maximum blockage level, then the system 10 may issue a warning in step 850 to notify the system operator ( or more) of the condition and may automatically initiate steps of a backwash operation (described above) whereby the flow regulating valves 115, 116 of the seawater cooling loop 12 may be closed and the flow regulating valves 117, 118 may be opened to reverse the flow of seawater through the heat exchanger 15. backwash may reduce or eliminate blockage in the system 10.
After the backwashing operation, the system 10 may repeat the blockage level test in step 860 to determine a new contemporaneous blockage level in step 870, the new contemporaneous blockage level may be compared to the maximum blockage level if it is determined that the contemporaneous blockage level still exceeds the maximum blockage level, the system 10 may repeat the backwashing procedure in step 880.
As will be appreciated, the exemplary method facilitates automatic monitoring and mitigation of blockages in the system 10, thereby reducing manual monitoring and intervention required to operate and maintain the system 10.
Referring now to FIG. 9, a method of switching adjustable pumps for overlapping operation of the pumps 16, 18, 20 will be described when the system switches from pumps to another pumps (during a planned switch, alarm, or cascade), the pressure may fluctuate due to the time gap between switches, decreasing in most cases.
To minimize or eliminate such alarms, during operation, if operating a pump 16, 28, 20 must shut down (e.g., due to various system normal operations or shut down alarms), that pump will make a request to the backup pump.
This manner of initiating disconnection of the pump itself from operation can be a user configurable time delay, or it can be controlled to fall with a controlled rise of the backup pump to provide maximum stability of system pressure and/or maintain stability of flow.
In embodiments, if the originating pump does not receive an "ack" from the backup pump (e.g., due to a loss of communication over the communication line 46), the originating pump may continue to operate without being in a critical shutdown alarm if the communication line 46 is in good condition, the originating controller will get an "ack" from the backup controller to indicate that the backup controller has successfully engaged in operation, or that the backup controller is not capable of engaging in operation due to its own shutdown condition, in any case, the originating pump will thus shut down.
The disclosed configuration enables the starting and backup pumps to handshake with each other to coordinate pump switching operations to ensure proper operation of the cooling pump and to ensure proper flow is maintained within the system.
Referring to FIG. 9, a flow chart illustrating an exemplary method for operation of the pumps 16-20 in the overlapping system 10 is shown that may be employed to prevent system pressure fluctuations that may otherwise be caused by sudden pump shut-offs and starts when pumps are operating in place of the other pumps, such as may occur due to pump failure or scheduled pump switches as described above.
If the communication line 46 is in good condition and the second pump is able to receive the request and successfully activate, then the pump may prepare to shut down in step 910 however, if the communication line 46 is not in good condition and the pump does not receive an acknowledgement from the second pump for a predetermined amount of time, then the pump may continue normal operation without shutdown without being in a critical shut down alarm in step 930.
The "transition" operation from the th pump to the second pump described above may be performed in a simple time-limited manner, wherein the th pump continues to operate at its then-current speed for a predetermined amount of time after receiving confirmation from the second pump.
Thus, the exemplary method set forth in FIG. 9 facilitates a smooth and automatic transition between pumps 16-20 in system 10 in a manner that prevents or at least mitigates sudden loss of system pressure that might otherwise cause disruption of system operation.
The term "computer" as used herein may include any processor-based or microprocessor-based system including systems using microcontrollers, Reduced Instruction Set Circuits (RISC), Application Specific Integrated Circuits (ASICs), logic circuits, and any other circuit or processor capable of executing the functions described herein. The above examples are exemplary only, and are thus not intended to limit in any way the definition and/or meaning of the term "computer".
The computer system executes sets of instructions stored in of one or more storage elements to process input data.
The set of instructions may include various commands that direct a computer as a processor to perform specific operations, such as the methods and processes of embodiments of the present invention.
The term "software" as used herein includes any computer program stored in memory for execution by a computer, including RAM memory, ROM memory, EPROM memory, EEPROM memory, and non-volatile RAM (NVRAM) memory. The above memory types are exemplary only, and are thus not limiting as to the types of memory usable for storage of a computer program.
