Energy-saving system for frequency conversion control of ship sea water pump

Abstract

The invention discloses an energy-saving system for frequency conversion control of ship sea water pumps. The energy-saving system comprises at least two sea water pumps, a frequency converter control cabinet, a signal acquisition control box and a temperature sensor, the sea water pumps are driven by a frequency converter, one sea water pump is in a running state, the other sea water pumps are in a standby state, the sea water pumps are connected with the frequency converter control cabinet, and the signal acquisition control box carries out efficiency test analysis on the cooling state of the sea water pumps, obtains temperature meter data and sets a plurality of monitoring points. And obtaining temperature values of the monitoring points, summing and averaging to obtain temperature meter data. A sea water pump of an operating ship is basically configured to be a constant-speed full-power motor, and the sea water pump runs at the maximum rotating speed under different working conditions, so that great energy waste is caused. Under the low-load working condition of the ship, the sea water pump can be controlled to operate at a low rotating speed in a variable-frequency mode, and the energy-saving effect of the ship sea water pump can reach 60% or above.

Description

Technical Field

[0001] This invention relates to the field of seawater pump energy-saving technology, and more specifically, to an energy-saving system for a variable frequency control marine seawater pump. Background Technology

[0002] To achieve the strategic goals of greenhouse gas emission reduction in international shipping, the International Maritime Organization (IMO) and national government agencies have issued a series of strategic guidelines and industry standards related to carbon reduction. The existing Energy Efficiency Index (EEXI) and Carbon Intensity Index (CII) for ships have been mandatory since January 1, 2023, and the 80th meeting of the MEPC in 2023 updated the carbon reduction targets for the shipping sector. The domestic and international shipping industries are actively seeking better and more effective energy-saving and emission-reduction technologies and equipment to meet increasingly stringent regulatory requirements.

[0003] Seawater pumps, as standard equipment on every vessel, operate continuously during shipboard operations, consuming a significant amount of electrical energy. Current seawater pumps are generally equipped with fixed-speed, full-power motors, outputting power at full load. However, due to the diverse operating conditions of ships, such as full-load operation, low-load operation, and berthing operations, the required amount of seawater cooling varies. Traditional full-load operation of seawater pumps introduces a certain flow redundancy. Therefore, this invention proposes a variable frequency control system that adjusts the flow output of the seawater pump according to the different operating conditions of the ship. This reduces power consumption, saves fuel, and reduces carbon emissions.

[0004] There are currently no effective solutions to the problems in the relevant technologies. Summary of the Invention

[0005] In view of the problems in related technologies, this invention proposes an energy-saving system for variable frequency control of marine seawater pumps to overcome the aforementioned technical problems existing in the prior art.

[0006] Therefore, the specific technical solution adopted by the present invention is as follows: An energy-saving system for variable frequency control of marine seawater pumps includes at least two seawater pumps, a frequency converter control cabinet, a signal acquisition and control box, and a temperature sensor; The seawater pumps are driven by frequency converters, with one pump in operation and the others in standby mode. The seawater pump is connected to the frequency converter control cabinet. The signal acquisition and control box performs efficiency testing and analysis on the cooling status of the seawater pump, obtains thermometer data, sets up several monitoring points, obtains the temperature values ​​of the monitoring points, sums them and takes the average value to obtain the thermometer data. The temperature sensors include a freshwater temperature sensor installed at the freshwater outlet and a seawater temperature sensor installed at the seawater outlet. The freshwater temperature sensor and the seawater temperature sensor are connected to the frequency converter control cabinet through the signal acquisition and control box.

[0007] Preferably, the signal acquisition and control box acquires the pressure value of the seawater main pipe and controls the speed of the seawater pump to adjust the pressure of the system main pipe to the set value.

[0008] Preferably, the inverter control cabinet controls the opening of the remote control valve to meet the user's requirement of maintaining the set temperature during operation. The calculation formula between speed and flow rate follows the law of proportionality, that is, the flow rate is directly proportional to the speed, specifically: Q1 / Q2 = N1 / N2.

[0009] Preferably, the head is proportional to the square of the rotational speed, specifically: H1 / H2 = (N1 / N2)²; Power consumption is proportional to the cube of the rotational speed, specifically: P1 / P2 = (N1 / N2)³.

[0010] Preferably, when the ship is operating under low load, the frequency converter control cabinet controls the seawater pump speed to 1 / 2 of the rated speed, then the power consumption is 1 / 8 of the rated power of the seawater pump, and the energy saving effect can theoretically reach 87.5%.

[0011] Preferably, when the seawater frequency conversion system is powered on, the signal acquisition and control box acquires the seawater temperature on the user side, and the frequency converter control cabinet controls the opening of valves NV1-NV3 to meet the user's requirement of maintaining the set temperature during operation.

[0012] Preferably, the frequency converter control cabinet determines whether the real-time temperature is greater than the rated temperature; when the real-time temperature is greater than the rated temperature, the frequency converter control cabinet controls any one of the seawater pumps to increase its operating frequency.

[0013] Preferably, the frequency converter control cabinet accumulates the working time of each seawater pump and controls the working time of each seawater pump.

[0014] Preferably, the method for increasing the operating frequency of any of the seawater pumps is to increase the operating frequency of the seawater pump in the running state and / or to start the seawater pump in the standby state by frequency conversion.

[0015] Preferably, the duration of the frequency conversion of the seawater pump is marked as a test cycle, and the frequency conversion efficiency of the main unit is analyzed within the test cycle, and the efficiency reduction parameter is generated based on the analysis results.

[0016] The beneficial effects of this invention are as follows: The basic configuration of seawater pumps on operating vessels is a fixed-speed, full-power motor. Under different operating conditions, the seawater pumps operate at maximum speed, resulting in significant energy waste. Under low-load conditions, this invention allows for variable frequency control of the seawater pumps, enabling energy savings of over 60%. For example, with two 30kW seawater pumps on a vessel, annual fuel savings can reach over 60 tons, CO2 emissions can be reduced by over 200 tons, and CII (Clean Energy Intake) can be improved by over 1%. The higher the power of the original seawater pump, the better the fuel-saving and emission-reduction effect. The seawater pumps can achieve frequency speed regulation to output different flow rates under different operating conditions, optimizing the overall energy efficiency of the seawater pumps, reducing power consumption, and thus achieving energy conservation and emission reduction. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an energy-saving system for a variable frequency controlled marine seawater pump according to an embodiment of the present invention; Figure 2 This is one of the system diagrams for controlling the frequency converter control cabinet according to an embodiment of the present invention; Figure 3 This is a second system diagram of the control cabinet for the frequency converter according to an embodiment of the present invention; Figure 4 This is a diagram of a frequency converter control electrical system according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the variable frequency control seawater pipeline modification according to an embodiment of the present invention; Figure 6 This is one of the schematic diagrams of a frequency converter control cabinet according to an embodiment of the present invention; Figure 7 This is the second schematic diagram of the inverter control cabinet according to an embodiment of the present invention. Detailed Implementation

[0019] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0020] According to an embodiment of the present invention, an energy-saving system for variable frequency control of a marine seawater pump is provided. Example

[0021] like Figure 1-7 As shown, the energy-saving system for variable frequency control of marine seawater pumps according to an embodiment of the present invention includes at least two seawater pumps, a frequency converter control cabinet, a signal acquisition and control box, and a temperature sensor. The seawater pumps are driven by frequency converters, with one pump in operation and the others in standby mode. The seawater pump is connected to the frequency converter control cabinet. The signal acquisition and control box performs efficiency testing and analysis on the cooling status of the seawater pump, obtains thermometer data, sets up several monitoring points, obtains the temperature values ​​of the monitoring points, sums them and takes the average value to obtain the thermometer data; The temperature sensors include a freshwater temperature sensor installed at the freshwater outlet and a seawater temperature sensor installed at the seawater outlet. The freshwater temperature sensor and the seawater temperature sensor are connected to the frequency converter control cabinet through a signal acquisition control box.

[0022] The seawater pumps on operating vessels are basically equipped with constant speed full-power motors. Under different operating conditions, the seawater pumps run at maximum speed, resulting in a great deal of energy waste. Example

[0023] like Figure 1-7 As shown, the signal acquisition and control box collects the pressure value of the seawater main pipe and controls the speed of the seawater pump to adjust the pressure of the main pipe to the set value. The frequency converter control cabinet controls the opening of the remote control valve to meet the user's requirement of maintaining the set temperature. The calculation formula between speed and flow rate follows the proportional law, that is, the flow rate is directly proportional to the speed, specifically: Q1 / Q2 = N1 / N2. The head is directly proportional to the square of the speed, specifically: H1 / H2 = (N1 / N2)². The power consumption is directly proportional to the cube of the speed, specifically: P1 / P2 = (N1 / N2)³.

[0024] Under low-load conditions on ships, the variable frequency control of the seawater pumps of this invention can achieve energy savings of more than 60% by operating the seawater pumps at low speeds. Taking a ship equipped with two 30KW seawater pumps as an example, it can save more than 60 tons of fuel and reduce CO2 emissions by more than 200 tons per year. Example

[0025] like Figure 1-7As shown, when the ship is operating under low load, the frequency converter control cabinet controls the seawater pump speed to 1 / 2 of the rated speed, resulting in a power consumption of 1 / 8 of the rated power of the seawater pump. Theoretically, the energy-saving effect can reach 87.5%. When the seawater frequency converter system is powered on, the signal acquisition and control box collects the seawater temperature on the user side. The frequency converter control cabinet controls the opening of valves NV1-NV3 to meet the user's requirement of maintaining the set temperature. The frequency converter control cabinet determines whether the real-time temperature is greater than the rated temperature. When the real-time temperature is greater than the rated temperature, the frequency converter control cabinet controls any one of the seawater pumps to increase its operating frequency. The frequency converter control cabinet accumulates the working time of each seawater pump and controls the working time of each seawater pump.

[0026] The greater the power of the original ship's seawater pump, the better the fuel saving and emission reduction effect. The seawater pump can achieve frequency speed regulation to output different flow rates in different working conditions, optimize the overall energy efficiency of the seawater pump, reduce power consumption, and thus achieve energy saving and emission reduction. Example

[0027] like Figure 1-7 As shown, the method to increase the operating frequency of any seawater pump is to increase the operating frequency of the seawater pump in operation and / or to start the seawater pump in standby mode by frequency conversion. The duration of frequency conversion of the seawater pump is marked as the test cycle. Within the test cycle, the frequency conversion efficiency of the main unit is analyzed and the efficiency reduction parameters are generated based on the analysis results.

[0028] In summary, using the technical solution of this invention, the seawater pumps on operating vessels are basically configured with fixed-speed, full-power motors. Under different operating conditions, the seawater pumps operate at maximum speed, resulting in significant energy waste. Under low-load conditions, this invention allows the variable frequency drive to control the seawater pumps at low speeds, achieving energy savings of over 60%. Taking a vessel equipped with two 30kW seawater pumps as an example, this can save over 60 tons of fuel annually and reduce CO2 emissions by over 200 tons. CII (Clean Energy Intake) can be improved by over 1%. The higher the power of the original seawater pump, the better the fuel-saving and emission-reduction effect. The seawater pumps can achieve frequency speed regulation to output different flow rates under different operating conditions, optimizing the overall energy efficiency of the seawater pumps, reducing power consumption, and thus achieving energy conservation and emission reduction.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving system for a variable frequency controlled marine seawater pump, characterized in that, It includes at least two seawater pumps, a frequency converter control cabinet, a signal acquisition and control box, and a temperature sensor; The seawater pumps are driven by frequency converters, with one pump in operation and the others in standby mode. The seawater pump is connected to the frequency converter control cabinet. The signal acquisition and control box performs efficiency testing and analysis on the cooling status of the seawater pump, obtains thermometer data, sets up several monitoring points, obtains the temperature values ​​of the monitoring points, sums them and takes the average value to obtain the thermometer data. The temperature sensors include a freshwater temperature sensor installed at the freshwater outlet and a seawater temperature sensor installed at the seawater outlet. The freshwater temperature sensor and the seawater temperature sensor are connected to the frequency converter control cabinet through the signal acquisition and control box.

2. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 1, characterized in that, The signal acquisition and control box acquires the pressure value of the seawater main pipe and controls the speed of the seawater pump to adjust the pressure of the system main pipe to the set value.

3. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 2, characterized in that, The inverter control cabinet controls the opening of the remote control valve to meet the user's requirement of maintaining the set temperature. The calculation formula between speed and flow rate follows the proportional law, that is, the flow rate is directly proportional to the speed. The specific relationship is: Q1 / Q2 = N1 / N2.

4. An energy-saving system for a variable frequency controlled marine seawater pump according to claim 3, characterized in that, The head is directly proportional to the square of the rotational speed, specifically: H1 / H2 = (N1 / N2)²; Power consumption is proportional to the cube of the rotational speed, specifically: P1 / P2 = (N1 / N2)³.

5. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 4, characterized in that, When the ship is operating under low load, the frequency converter control cabinet controls the seawater pump speed to 1 / 2 of the rated speed, and the power consumption is 1 / 8 of the rated power of the seawater pump. Theoretically, the energy saving effect can reach 87.5%.

6. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 5, characterized in that, When the seawater frequency conversion system is powered on, the signal acquisition and control box collects the seawater temperature on the user side, and the frequency converter control cabinet controls the opening of valves NV1-NV3 to ensure that the user maintains the set temperature during operation.

7. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 6, characterized in that, The frequency converter control cabinet determines whether the real-time temperature is greater than the rated temperature; when the real-time temperature is greater than the rated temperature, the frequency converter control cabinet controls any one of the seawater pumps to increase its operating frequency.

8. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 7, characterized in that, The frequency converter control cabinet accumulates the working time of each of the seawater pumps and controls the working time of each of the seawater pumps.

9. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 8, characterized in that, The method for increasing the operating frequency of any of the seawater pumps is to increase the operating frequency of the seawater pump in the running state and / or to start the seawater pump in the standby state by frequency conversion.

10. The energy-saving system for a variable frequency controlled marine seawater pump according to claim 9, characterized in that, The duration of the frequency conversion of the seawater pump is marked as the test cycle. Within the test cycle, the frequency conversion efficiency of the main unit is analyzed, and the efficiency reduction parameters are generated based on the analysis results.

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