Feedforward control method and device for ship seawater cooling frequency conversion system
阅读说明：本技术 船舶海水冷却变频系统前馈控制方法及装置 (Feedforward control method and device for ship seawater cooling frequency conversion system ) 是由 陆利平 李俊 黄信男 王成 于 2019-11-12 设计创作，主要内容包括：本发明提供了一种船舶海水冷却变频系统前馈控制方法及装置,涉及海水冷却变频系统的技术领域,方法包括获取中央冷却器水进口温度；根据所述水进口温度得到预设采样时间间隔内的水进口温度变化；当水进口温度变化超过预设温度变化阈值时,计算当前时刻所需的海水流量；控制海水变频系统调节海水泵流量,以使海水泵流量达到当前时刻所需的海水流量。本发明能够在船舶系统热负荷突然大幅波动或者海水温度突然大幅波动时提前进行预判,从而实现系统的主动调节,确保船舶的安全运行。(The invention provides a feedforward control method and a feedforward control device for a ship seawater cooling frequency conversion system, and relates to the technical field of seawater cooling frequency conversion systems, wherein the method comprises the steps of obtaining the water inlet temperature of a central cooler; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet; when the temperature change of the water inlet exceeds a preset temperature change threshold value, calculating the flow of the seawater required at the current moment; and controlling the seawater frequency conversion system to adjust the flow of the seawater pump so as to enable the flow of the seawater pump to reach the seawater flow required at the current moment. The invention can carry out prejudgment in advance when the heat load of the ship system suddenly fluctuates greatly or the seawater temperature suddenly fluctuates greatly, thereby realizing the active adjustment of the system and ensuring the safe operation of the ship.)
1. A feedforward control method for a ship seawater cooling frequency conversion system is characterized by comprising the following steps:
acquiring the water inlet temperature of a central cooler; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet;
when the temperature change of the water inlet exceeds a preset temperature change threshold value, calculating the flow of the seawater required at the current moment;
and controlling the seawater frequency conversion system to adjust the flow of the seawater pump so as to enable the flow of the seawater pump to reach the seawater flow required at the current moment.
2. The control method according to claim 1, wherein the water inlet temperature comprises a fresh water inlet temperature, and when the water inlet temperature changes by more than a preset temperature change threshold, the step of calculating the required seawater flow at the current moment comprises:
and when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value, calculating the flow of the seawater required at the current moment.
3. The control method according to claim 1 or 2, wherein the water inlet temperature comprises a seawater inlet temperature, and when the water inlet temperature changes by more than a preset temperature change threshold, the step of calculating the required seawater flow at the current time comprises:
and when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value, calculating the seawater flow required at the current moment.
4. The control method of claim 3, wherein the step of controlling the seawater frequency conversion system to adjust the flow rate of the seawater pump so that the flow rate of the seawater pump reaches the required seawater flow rate at the current moment comprises:
acquiring current seawater flow;
calculating the required seawater flow at the current moment according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature of the central cooler, Tf2 is the fresh water inlet temperature of the central cooler, Qf is the fresh water flow, Ts1 is the seawater outlet temperature of the central cooler, Ts2 is the seawater inlet temperature of the central cooler, Qs is the seawater flow, and Cs is the specific heat of the seawater; cf is the specific heat of fresh water;
and adjusting the rotating speed of the seawater pump according to the current seawater flow and the seawater flow required at the current moment so as to enable the current seawater flow to reach the seawater flow required at the current moment.
5. The utility model provides a boats and ships sea water cooling frequency conversion system feedforward control device which characterized in that includes:
the water inlet temperature acquisition module is used for acquiring the water inlet temperature of the central cooler; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet;
the seawater flow calculation module is used for calculating the required seawater flow at the current moment when the temperature change of the water inlet exceeds a preset temperature change threshold value;
and the seawater pump flow adjusting module is used for controlling the seawater frequency conversion system to adjust the seawater pump flow so as to enable the seawater pump flow to reach the seawater flow required at the current moment.
6. The control apparatus of claim 5, wherein the water inlet temperature comprises a fresh water inlet temperature; the seawater flow calculation module comprises:
and the first seawater pump flow adjusting module is used for calculating the seawater flow required at the current moment when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value.
7. The control device of claim 5 or 6, wherein the water inlet temperature comprises a seawater inlet temperature; the seawater flow calculation module comprises: the method comprises the following steps:
and the second seawater pump flow adjusting module is used for calculating the required seawater flow at the current moment when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value.
8. The control device of claim 5, wherein the seawater pump flow regulating module comprises:
the acquisition module is used for acquiring the current seawater flow;
the calculating module is used for calculating the seawater flow required at the current moment according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature of the central cooler, Tf2 is the fresh water inlet temperature of the central cooler, Qf is the fresh water flow, Ts1 is the seawater outlet temperature of the central cooler, Ts2 is the seawater inlet temperature of the central cooler, Qs is the seawater flow, and Cs is the specific heat of the seawater; cf is the specific heat of fresh water;
and the adjusting module is used for adjusting the rotating speed of the seawater pump according to the current seawater flow and the seawater flow required at the current moment so as to enable the current seawater flow to reach the seawater flow required at the current moment.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the steps of the method of any of the preceding claims 1 to 4 are implemented when the computer program is executed by the processor.
10. A computer-readable medium having non-volatile program code executable by a processor, wherein the program code causes the processor to perform the method of any of claims 1 to 4.
Technical Field
The invention relates to the technical field of seawater cooling frequency conversion systems, in particular to a feedforward control method and device for a ship seawater cooling frequency conversion system.
Background
At present, most of marine seawater cooling frequency conversion systems are passively adjusted, namely when the temperature of a fresh water outlet of a central cooler deviates from a set value of a control system, a frequency converter adjusts the rotating speed of a seawater pump to increase or decrease, so that the temperature of the fresh water outlet of the central cooler returns to the set value; the passive regulation mode can generate a certain degree of regulation lag when the thermal load change amplitude of the ship is large or the seawater temperature change amplitude is large, and the safe operation of a ship system can be influenced.
Disclosure of Invention
The invention aims to provide a feedforward control method and a feedforward control device for a ship seawater cooling frequency conversion system, which can be used for carrying out prejudgment in advance when the thermal load of the ship system suddenly fluctuates greatly or the seawater temperature suddenly fluctuates greatly, so that the active adjustment of the system is realized, and the safe operation of a ship is ensured.
In a first aspect, an embodiment provides a feedforward control method for a ship seawater cooling frequency conversion system, including:
acquiring the water inlet temperature of a central cooler; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet;
when the temperature change of the water inlet exceeds a preset temperature change threshold value, calculating the flow of the seawater required at the current moment;
and controlling the seawater frequency conversion system to adjust the flow of the seawater pump so as to enable the flow of the seawater pump to reach the seawater flow required at the current moment.
In an alternative embodiment, the water inlet temperature includes a fresh water inlet temperature, and when the water inlet temperature changes by more than a preset temperature change threshold, the step of calculating the required seawater flow at the current time includes:
and when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value, calculating the flow of the seawater required at the current moment.
In an alternative embodiment, the water inlet temperature includes a seawater inlet temperature, and when the water inlet temperature changes beyond a preset temperature change threshold, the step of calculating the required seawater flow at the current time includes:
and when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value, calculating the seawater flow required at the current moment.
In an optional embodiment, the step of controlling the seawater frequency conversion system to adjust the flow rate of the seawater pump so that the flow rate of the seawater pump reaches the seawater flow rate required at the current time includes:
acquiring current seawater flow;
calculating the required seawater flow at the current moment according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature of the central cooler, Tf2 is the fresh water inlet temperature of the central cooler, Qf is the fresh water flow, Ts1 is the seawater outlet temperature of the central cooler, Ts2 is the seawater inlet temperature of the central cooler, Qs is the seawater flow, and Cs is the specific heat of the seawater; cf is the specific heat of fresh water;
and adjusting the rotating speed of the seawater pump according to the current seawater flow and the seawater flow required at the current moment so as to enable the current seawater flow to reach the seawater flow required at the current moment.
In a second aspect, an embodiment provides a feed-forward control device for a ship seawater cooling frequency conversion system, including:
the water inlet temperature acquisition module is used for acquiring the water inlet temperature of the central cooler; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet;
the seawater flow calculation module is used for calculating the required seawater flow at the current moment when the temperature change of the water inlet exceeds a preset temperature change threshold value;
and the seawater pump flow adjusting module is used for controlling the seawater frequency conversion system to adjust the seawater pump flow so as to enable the seawater pump flow to reach the seawater flow required at the current moment.
In an alternative embodiment, the water inlet temperature comprises a fresh water inlet temperature; the seawater flow calculation module comprises:
and the first seawater pump flow adjusting module is used for calculating the seawater flow required at the current moment when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value.
In an alternative embodiment, the water inlet temperature comprises a seawater inlet temperature; the seawater flow calculation module comprises: the method comprises the following steps:
and the second seawater pump flow adjusting module is used for calculating the required seawater flow at the current moment when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value.
In an alternative embodiment, the seawater pump flow regulating module comprises:
the acquisition module is used for acquiring the current seawater flow;
the calculating module is used for calculating the seawater flow required at the current moment according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature of the central cooler, Tf2 is the fresh water inlet temperature of the central cooler, Qf is the fresh water flow, Ts1 is the seawater outlet temperature of the central cooler, Ts2 is the seawater inlet temperature of the central cooler, Qs is the seawater flow, and Cs is the specific heat of the seawater; cf is the specific heat of fresh water;
and the adjusting module is used for adjusting the rotating speed of the seawater pump according to the current seawater flow and the seawater flow required at the current moment so as to enable the current seawater flow to reach the seawater flow required at the current moment.
In a third aspect, embodiments provide an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where the processor implements the steps of the method of any one of the foregoing embodiments when executing the computer program.
In a fourth aspect, embodiments provide a computer readable medium having non-volatile program code executable by a processor, the program code causing the processor to perform the method of any of the preceding embodiments.
According to the feedforward control method and device for the ship seawater cooling frequency conversion system, when the heat load of the ship system suddenly fluctuates greatly or the seawater temperature suddenly fluctuates greatly, the temperature of the water inlet of a central cooler is obtained; obtaining the temperature change of the water inlet within a preset sampling time interval according to the temperature of the water inlet, and calculating the flow of the seawater required at the current moment when the temperature change of the water inlet exceeds a preset temperature change threshold; therefore, prejudgment is carried out in advance, and the seawater frequency conversion system can be controlled to adjust the flow of the seawater pump so as to enable the flow of the seawater pump to reach the seawater flow required at the current moment; therefore, the active adjustment of the ship seawater cooling frequency conversion system is realized, and the safety of the ship is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flowchart of a control method of a seawater cooling frequency conversion system according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a seawater cooling frequency conversion system according to an embodiment of the present invention;
fig. 3 is a system schematic diagram of a control device of a seawater cooling frequency conversion system according to an embodiment of the present invention;
fig. 4 is a system schematic diagram of an electronic device according to an embodiment of the present invention.
Icon: 21-a central cooler; 22-fresh water inlet temperature sensor; 23-fresh water inlet flow sensor; 24-fresh water outlet temperature sensor; 25-seawater inlet temperature sensor; 26-seawater inlet flow sensor; 27-seawater outlet temperature sensor; 31-a water inlet temperature acquisition module; 32-a seawater flow calculation module; 33-a seawater pump flow regulating module; 400-an electronic device; 401 — a communication interface; 402-a processor; 403-a memory; 404-bus.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the present invention, it should be noted that, in addition, the terms "first", "second", "third", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as meaning either a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Some embodiments of the invention are described in detail below with reference to the accompanying drawings. The embodiments described below and the features of the embodiments can be combined with each other without conflict.
At present, the application of a seawater variable-frequency cooling system on ships is more and more common, and when the temperature of seawater is reduced or the heat load of the ships is reduced, a seawater pump can operate at a lower rotating speed, so that the power of a motor is reduced, and the purposes of energy conservation and emission reduction are achieved. When the heat load of the ship is reduced, the temperature of the fresh water outlet of the central cooler is reduced and deviates from a preset target value, at the moment, the seawater frequency conversion system starts to act, the frequency is reduced, the rotating speed of the seawater pump is reduced, the seawater flow is reduced, and the temperature of the fresh water outlet of the central cooler is increased and returns to the target value. However, in the current technology, no matter the heat load of the ship changes or the temperature of the seawater changes, the seawater frequency conversion system starts to act after the temperature of the fresh water outlet of the central cooler deviates from a set value, the temperature of the fresh water outlet is pulled back to a target set value, and the regulation lag occurs, so that the passive regulation mode influences the safe operation of the ship system.
Based on the method, the feedforward control method and the feedforward control device for the ship seawater cooling frequency conversion system can realize active adjustment of the seawater cooling frequency conversion system, when the heat load of the ship system suddenly fluctuates greatly or the seawater temperature suddenly fluctuates greatly, the system can pre-judge in advance, and adjust the rotating speed of the seawater pump in advance, namely, the active adjustment of the seawater frequency conversion cooling system is realized, and the safe operation of ship equipment is ensured.
Referring to fig. 1, a feedforward control method for a ship seawater cooling frequency conversion system includes:
s110: acquiring the water inlet temperature of the
s120: when the temperature change of the water inlet exceeds a preset temperature change threshold value, calculating the flow of the seawater required at the current moment;
s130: and controlling the seawater frequency conversion system to adjust the flow of the seawater pump so as to enable the flow of the seawater pump to reach the seawater flow required at the current moment.
In particular, a central cooling inverter system of a ship is one of the most important ship auxiliary devices for supplying cooling water to a thermal load of the ship. The central cooling frequency conversion system of the ship mainly comprises a sea water pump, a fresh water pump, a
As shown in fig. 2, the
The water inlet temperature in this embodiment includes a seawater inlet temperature detected by the seawater
Wherein, the required seawater flow at the current moment is also calculated according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature, Tf2 is the fresh water inlet temperature, Qf is the fresh water flow, Ts1 is the seawater outlet temperature, Ts2 is the seawater inlet temperature, Qs is the seawater flow, and Cs is the seawater specific heat; cf is the specific heat of fresh water.
And obtaining Qs (the seawater flow required at the current moment) through the above formula, comparing the Qs with the current seawater flow Qs ', and adjusting the rotating speed of the seawater pump according to the comparison result to enable Qs' to be equal to Qs.
The fresh water outlet temperature Tf1 is obtained through a fresh water
Preferably, when the absolute value of the fresh water inlet temperature Tf2 of the
Preferably, the next operation can be performed by obtaining the seawater inlet temperature Ts2 of the
In this embodiment, the heat load variation and the seawater temperature variation of the system are determined by determining the temperature variation range of the water inlet of the
Optionally, the water inlet temperature comprises a fresh water inlet temperature, and step S120 comprises:
and when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value, calculating the flow of the seawater required at the current moment.
Specifically, step S110 obtains the change in the fresh water inlet temperature of the
At this time, there are two cases. In the first case, when the thermal load of the ship is suddenly and greatly increased, the system starts the feedforward control, and the required seawater flow at the current moment
When the heat load of the ship is suddenly and greatly reduced, the system starts feedforward control, and the required seawater flow at the current moment
Optionally, the water inlet temperature includes a seawater inlet temperature, and step S120 includes:
and when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value, calculating the seawater flow required at the current moment.
Specifically, by acquiring the seawater inlet temperature variation of the
At the moment, two situations also exist, when the temperature of the seawater is suddenly and greatly increased, the system starts feedforward control, and the required seawater flow at the moment is
When the temperature of the seawater is suddenly and greatly reduced, the system starts feedforward control, and the required seawater flow at the current moment
Compared with the prior art, the method has the advantages that when the heat load of the ship or the temperature of the seawater is greatly changed, the required seawater flow rate after the heat load of the ship or the temperature of the seawater is changed is calculated according to the temperature and the flow rate fed back by the sensor, so that the frequency of the seawater variable-frequency cooling system can be adjusted in advance to meet the heat exchange required by the system, namely, feedforward control is realized.
The seawater flow required by the system is obtained according to the principle of energy conservation in the embodiment, including but not limited to the formula described above, and the installation positions of the temperature and flow sensors include but not limited to the positions shown in the figure.
As shown in fig. 3, a feedforward control device for a marine seawater cooling frequency conversion system includes:
a water inlet
the seawater
and the seawater pump
Optionally, the water inlet temperature comprises a fresh water inlet temperature; the seawater flow
and the first seawater pump flow adjusting module is used for calculating the seawater flow required at the current moment when the temperature change of the fresh water inlet exceeds a preset first temperature change threshold value.
Optionally, the water inlet temperature comprises a seawater inlet temperature; the seawater flow
and the second seawater pump flow adjusting module is used for calculating the required seawater flow at the current moment when the temperature change of the seawater inlet exceeds a preset second temperature change threshold value.
Specifically, the water inlet
and the fresh water inlet temperature acquisition module is used for acquiring the fresh water inlet temperature change of the
And the seawater inlet temperature acquisition module is used for acquiring the fresh water inlet temperature change of the
Optionally, the sea water pump flow regulating module includes:
the acquisition module is used for acquiring the current seawater flow;
the calculating module is used for calculating the seawater flow required at the current moment according to the following formula:
in the above formula, Tf1 is the fresh water outlet temperature of the central cooler, Tf2 is the fresh water inlet temperature of the central cooler, Qf is the fresh water flow, Ts1 is the seawater outlet temperature of the central cooler, Ts2 is the seawater inlet temperature of the central cooler, Qs is the seawater flow, and Cs is the specific heat of the seawater; cf is the specific heat of fresh water;
and the adjusting module is used for adjusting the rotating speed of the seawater pump according to the current seawater flow and the seawater flow required at the current moment so as to enable the current seawater flow to reach the seawater flow required at the current moment.
The embodiment adopts a feedforward control concept, the change of the system heat load is judged by judging the change amplitude of the fresh water inlet temperature, and the load change is considered to be overlarge when the change value exceeds a set value; the seawater flow required by the system is calculated by utilizing energy conservation, so that the frequency conversion system can realize accurate control.
Referring to fig. 4, an embodiment of the present invention further provides an apparatus, and an embodiment of the present invention further provides an electronic apparatus 400, which includes a communication interface 401, a processor 402, a memory 403, and a bus 404, where the processor 402, the communication interface 401, and the memory 403 are connected by the bus 404; the memory 403 is used for storing a computer program for supporting the processor 402 to execute the ship seawater cooling frequency conversion system control method, and the processor 402 is configured to execute the program stored in the memory 403.
Optionally, an embodiment of the present invention further provides a computer readable medium having a non-volatile program code executable by a processor, where the program code causes the processor to execute the ship seawater cooling frequency conversion system control method in the above embodiment.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
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