Control method and system of variable frequency evaporative condenser and storage medium

Abstract

This invention relates to the field of electronic digital data processing, specifically to a control method, system, and storage medium for a variable frequency evaporative condenser. The control method includes: controlling the operating frequency of the cooling fan and cooling water pump based on the deviation between the measured condensing temperature and the set condensing temperature; determining whether blowdown is necessary based on whether the calcium and magnesium ion concentration in the circulating water system reaches a threshold, thereby slowing down the scaling rate of the heat exchanger; and lowering the circulating water temperature by increasing the cooling fan frequency and changing the water, thereby preventing excessively high water temperatures from affecting the heat exchange performance of the evaporative condenser. This invention achieves a balance between energy saving, water saving, and scale prevention in air conditioning units, contributing to the efficient operation of evaporative condensing heat pump units.

Description

Technical Field

[0001] This invention relates to the field of electronic digital data processing, and in particular to a control method, system, and storage medium for a variable frequency evaporative condenser. Background Technology

[0002] Evaporative condensing chillers (heat pumps) utilize evaporative condensers as air-side heat exchangers in their cooling operation, leveraging the latent heat of vaporization of water to condense the refrigerant, resulting in high heat exchange efficiency. Influenced by factors such as meteorological parameters and system load variations, evaporative condensers often operate under partial load conditions. Insufficient output from the cooling fan and cooling water pump will increase the unit's measured condensing temperature and reduce energy efficiency; conversely, excessive output will lead to excessively high input power, similarly reducing energy efficiency. Therefore, properly adjusting the output of these components is crucial for improving unit energy efficiency. Currently, most evaporative condensers on the market employ fixed-frequency control, resulting in higher input power and reduced energy efficiency.

[0003] Meanwhile, due to the continuous evaporation of circulating water in the evaporative condenser, the concentration of calcium and magnesium ions gradually increases. It is necessary to dilute the concentration of calcium and magnesium ions in the circulating water through blowdown and makeup water to slow down scaling on the heat exchange tubes. Currently, the blowdown control strategy is mainly based on time. However, since the evaporation rate of water varies under different operating conditions, the concentration rate of calcium and magnesium ions also varies. Therefore, the time-based control strategy is not accurate, and a balance between water conservation and scale prevention needs to be considered.

[0004] In addition, as the circulating water system continuously absorbs heat from the refrigerant, the temperature of the circulating water gradually rises, affecting the heat exchange performance of the evaporative condenser. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a control method, system and storage medium for a variable frequency evaporative condenser, so as to achieve a balance between energy saving, water saving and scale prevention in the unit.

[0006] In a first aspect, the present invention provides a control method for a variable frequency evaporative condenser, wherein the stable operation phase includes the following steps:

[0007] S1: Every interval Time, measuring ambient wet-bulb temperature Water replenishment temperature Heating capacity of the unit and measured condensation temperature ; S2: Based on ambient wet-bulb temperature Heating capacity of the unit The computer group's set condensing temperature and the set limit temperature of circulating water ; S3: Based on the measured condensation temperature With set condensation temperature Calculate and set the cooling water pump frequency based on the deviation. and cooling fan frequency After the calculation is completed, the cooling fan frequency will be... Stored in variables In, that is ; S4: Every interval The timer checks whether both the sewage and water replenishment systems are turned on. If not, the process ends; if so, the circulating water temperature is checked. and water level in the collection tank Proceed to the next step; S5: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If not, the process ends; if yes, the calcium and magnesium ion concentrations of the circulating water system are approximately calculated. After the calculation is completed, update the circulating water volume. ; and The calculation method is as follows:

[0008]

[0009] in, The bottom area of ​​the water collection tank; S6: Determine the calcium and magnesium ion concentration in the circulating water system Is it greater than the threshold? If yes, proceed to the next step; otherwise, proceed to S9. S7: Activate the sewage system and drain sewage to the water change level. ; S8: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows:

[0010]

[0011] in, The concentration of calcium and magnesium ions for water replenishment; S9: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows:

[0012]

[0013] During the execution of S5-S9, S10-S13 are executed simultaneously; S10: Determine the circulating water temperature Is it greater than the set limit water temperature? If no, the process ends; if yes, proceed to the next step. S11: Determine the frequency of the cooling fan Is it equal to the maximum value of the frequency conversion range of the cooling fan? If yes, proceed to the next step; if no, increase the cooling fan frequency and end the process. S12: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If no, proceed to the next step; if yes, end the process. S13: Simultaneously activate the sewage discharge system and the water replenishment system, with both sewage discharge and water replenishment capacities set at [value missing]. And approximately calculate the calcium and magnesium ion concentrations in the circulating water system. Update the circulating water volume after the calculation is complete. Meanwhile, the frequency of the cooling fan for And end the process; and The calculation method is as follows:

[0014]

[0015]

[0016] In the formula, This is the proportionality coefficient; Among them, each interval Re-execute S1 at each interval. At that time, S4 will be re-executed.

[0017] Preferably, in step S2: the condensation temperature is set. The calculation method is as follows:

[0018] in, , is a coefficient.

[0019] Preferably, in step S2: a set limit temperature for the circulating water is set. The calculation method is as follows:

[0020] in, , is a coefficient.

[0021] Preferably, in step S3: calculating the cooling water pump frequency , ,if Then set the cooling water pump frequency. ;if Then set the cooling water pump frequency. The frequency conversion range of the cooling water pump is limited to... - , This is the proportional control coefficient.

[0022] Preferably, in step S3: calculating the frequency of the cooling fan. , ,if Then set the cooling fan frequency. ;if Then set the cooling fan frequency. The frequency conversion range of the cooling fan is limited to... - , This is the proportional control coefficient.

[0023] Preferably, in S11: the frequency of the cooling fan The calculation method is as follows: , in, is a coefficient.

[0024] Preferably, the power-on phase includes the following steps: A1: After receiving the power-on signal, determine whether the downtime exceeds the set value. If no, proceed directly to A4; if yes, proceed to the next step. A2: Turn on the drainage system to completely drain all the water in the collection tank; A3: Turn on the water replenishment system and add water to the operating water level. Initialize the calcium and magnesium ion concentration of the circulating water system for Initialize circulating water volume ; A4: Turn on the cooling fan and cooling water pump, and set them to run at their rated frequencies; A5: Turn on the compressor.

[0025] Preferably, the shutdown phase includes the following steps: B1: Upon receiving a shutdown signal, the compressor stops running; B2: Turn off the cooling fan and cooling water pump.

[0026] In a second aspect, the present invention provides a control system for a variable frequency evaporative condenser, employing any of the control methods described above for a variable frequency evaporative condenser.

[0027] In a third aspect, the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device in which the computer-readable storage medium is located to perform any of the control methods for the variable frequency evaporative condenser described above.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a control method, system, and storage medium for a variable frequency evaporative condenser. Based on the deviation between the measured condensing temperature and the set condensing temperature, the operating frequency of the cooling fan and cooling water pump is controlled. Whether the calcium and magnesium ion concentration in the circulating water system reaches a threshold is used to determine whether sewage discharge is required, thereby slowing down the scaling rate of the heat exchanger. The circulating water temperature is reduced by increasing the cooling fan frequency and changing the water, thereby preventing the water temperature from being too high and affecting the heat exchange performance of the evaporative condenser.

[0029] This invention can achieve a balance between energy saving, water saving, and scale prevention in air conditioning units, thus helping evaporative condensing heat pump units to operate efficiently. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the variable frequency evaporative condenser described in Embodiment 1 of the present invention.

[0031] Figure 2 This is a control flowchart of the variable frequency evaporative condenser during the stable operation phase according to Embodiment 1 of the present invention.

[0032] Figure 3 This is a control flowchart of the variable frequency evaporative condenser during the start-up phase according to Embodiment 1 of the present invention.

[0033] Figure 4 This is a control flowchart of the variable frequency evaporative condenser during the shutdown phase according to Embodiment 1 of the present invention.

[0034] Figure 5 This is a comparison chart of test results for the commonly used fixed-frequency control method and the optimized control method described in this invention, as described in Embodiment 2 of the present invention.

[0035] Marked in the image: 1-Cooling fan, 2-Spray water pipe, 3-Water baffle, 4-Refrigerant pipe, 5-Packing layer, 6-Cooling water pump, 7-Water collection tank, 8-Water replenishment system, 9-Sewage system. Detailed Implementation

[0036] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0037] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0038] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0039] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0040] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0041] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0042] Example 1 Figure 1 A schematic diagram of a variable frequency evaporative condenser is shown. Figure 1As shown, it mainly consists of a cooling fan 1, a spray water pipe 2, a baffle plate 3, a refrigerant pipe 4, a packing layer 5, a cooling water pump 6, a water collection tank 7, a water replenishment system 8, and a sewage discharge system 9. Among them, the cooling fan 1 and the cooling water pump 6 are power equipment and are set to frequency conversion control; the water replenishment system and the sewage discharge system are water-using equipment and are both equipped with flow meters.

[0043] The frequency conversion range of the cooling water pump is limited to: - The frequency conversion range of the cooling fan is limited to - The bottom area of ​​the water collection tank is... The water collection tanks are equipped with separate operating water levels. Water replenishment level and water level change ,in, Evaporative condensers can operate stably at these four water levels.

[0044] like Figure 2 As shown, the present invention provides a control method for a variable frequency evaporative condenser, the stable operation stage of which includes the following steps: S1: Every interval Time, measuring ambient wet-bulb temperature Water replenishment temperature Heating capacity of the unit and measured condensation temperature .

[0045] S2: Based on ambient wet-bulb temperature Heating capacity of the unit The computer group's set condensing temperature and the set limit temperature of circulating water .

[0046] Preferably, the condensation temperature is set. The calculation method is as follows:

[0047] in, , is a coefficient.

[0048] Preferably, a set limit temperature for the circulating water is set. The calculation method is as follows:

[0049] in, , is a coefficient.

[0050] S3: Based on the measured condensation temperature With set condensation temperature Calculate and set the cooling water pump frequency based on the deviation. and cooling fan frequency After the calculation is completed, the cooling fan frequency will be... Stored in variables In, that is .

[0051] Preferably, the cooling water pump frequency is calculated and set. Includes: calculating the frequency of the cooling water pump , ,if Then set the cooling water pump frequency. ;if Then set the cooling water pump frequency. ,in, This is the proportional control coefficient.

[0052] Preferably, the frequency of the cooling fan is calculated and set. Includes: calculating the frequency of the cooling fan , ,if Then set the cooling fan frequency. ;if Then set the cooling fan frequency. ,in, This is the proportional control coefficient.

[0053] S4: Every interval The timer checks whether both the sewage and water replenishment systems are turned on. If not, the process ends; if so, the circulating water temperature is checked. and water level in the collection tank Proceed to the next step; S5: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If not, the process ends; if yes, the calcium and magnesium ion concentrations of the circulating water system are approximately calculated. After the calculation is completed, update the circulating water volume. ; and The calculation method is as follows:

[0054]

[0055] in, The bottom area of ​​the water collection tank; S6: Determine the calcium and magnesium ion concentration in the circulating water system Is it greater than the threshold? If yes, proceed to the next step; otherwise, proceed to S9. S7: Activate the sewage system and drain sewage to the water change level. ; S8: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows:

[0056]

[0057] in, The concentration of calcium and magnesium ions for water replenishment; S9: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows:

[0058]

[0059] During the execution of S5-S9, S10-S13 are executed simultaneously; S10: Determine the circulating water temperature Is it greater than the set limit water temperature? If no, the process ends; if yes, proceed to the next step. S11: Determine the frequency of the cooling fan Is it equal to the maximum value? If yes, proceed to the next step; if no, increase the cooling fan frequency and end the process. Preferably, the frequency of the cooling fan The calculation method is as follows: , in, is a coefficient.

[0060] S12: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If no, proceed to the next step; if yes, end the process. S13: Simultaneously activate the sewage discharge system and the water replenishment system, with both sewage discharge and water replenishment capacities set at [value missing]. And approximately calculate the calcium and magnesium ion concentrations in the circulating water system. Update the circulating water volume after the calculation is complete. Meanwhile, the frequency of the cooling fan for And end the process; and The calculation method is as follows:

[0061]

[0062]

[0063] In the formula, This is the proportionality coefficient; Among them, each interval Re-execute S1 at each interval. At that time, S4 will be re-executed.

[0064] Preferably, the control method of the present invention includes three stages: power-on, stable operation, and power-off, wherein, as shown in the figure... Figure 3 As shown, the power-on phase includes the following steps: A1: After receiving the power-on signal, determine whether the downtime exceeds the set value. If not, proceed directly to S4; if yes, proceed to the next step. A2: Turn on the drainage system to completely drain all the water in the collection tank; A3: Turn on the water replenishment system and add water to the operating water level. Initialize the calcium and magnesium ion concentration of the circulating water system for Initialize circulating water volume ; A4: Turn on the cooling fan and cooling water pump, and set them to run at their rated frequencies; A5: Turn on the compressor.

[0065] like Figure 4 As shown, the shutdown process includes the following steps: B1: Upon receiving a shutdown signal, the compressor stops running; B2: Turn off the cooling fan and cooling water pump.

[0066] Example 2 Based on Example 1, this example uses a variable frequency evaporative condensing chiller unit with a nominal cooling capacity of 575kW as an example. Its evaporative condenser is equipped with two units with a rated air volume of 40,000 m³ / h. 3 A variable frequency axial flow fan with a rated power of 4.3kW per unit and a frequency range of [missing information - likely a range of values]. The frequency is 30-50Hz; one unit with a rated flow rate of 130m³ / h is configured. 3 A variable frequency cooling water pump with a rated power of 3.0kW and a frequency range of [missing information - likely a variable frequency range] / h. The frequency is 30-50Hz. The formula for calculating the set condensing temperature is: The formula for calculating the set limit temperature of circulating water is: Based on the measured condensation temperature With set condensation temperature The deviation was calculated, and the frequency coefficients of the cooling water pump and cooling fan were determined. and Both are 2; based on the circulating water temperature With the set limit temperature of circulating water The deviation calculation coefficient of the cooling fan frequency Take 3; calculate in S13 of Take 3. The calcium and magnesium ion concentration in the makeup water is 113 mg / L. What is the calcium and magnesium ion concentration threshold for the circulating water system? The concentration is set at 600 mg / L; the operating water level in the collection tank is... Water replenishment level and water level change The bottom areas of the water collection tanks are 0.5m, 0.4m, and 0.2m respectively. 9m 2 Interval time and Set to 5 minutes and 1 minute respectively. (Downtime settings) It takes 12 hours.

[0067] Taking a specific operating condition as an example, under this condition, the ambient wet-bulb temperature is set to 22℃ and the unit outlet water temperature is 7℃. The first step is the control process during the start-up phase.

[0068] A1: After receiving the start-up signal, the unit detected a shutdown duration of 15.3 hours, which exceeds the set value of 12 hours. Proceed to the next step.

[0069] A2: Turn on the drainage system to completely drain all the water in the collection tank.

[0070] A3: Turn on the water replenishment system and add water to the operating water level. Initialize the calcium and magnesium ion concentrations in the circulating water system. The initial circulating water volume is 113 mg / L. It is 5.4m 3 .

[0071] A4: Turn on the cooling fan and cooling water pump, and set both to run at 50Hz.

[0072] A5: Turn on the compressor and other components.

[0073] After stable operation, the control process for stable operation is introduced using a specific moment as an example. At this time, the operating frequency of both the cooling fan and the cooling water pump is 42Hz, and the calcium and magnesium ion concentration in the circulating water system is... The concentration was 383 mg / L, and the circulating water volume was... It is 4.5m 3 .

[0074] S1: Detect ambient wet-bulb temperature The water replenishment temperature is 21.9℃. The heating capacity of the evaporative condensing chiller unit is 15.7℃. The actual condensing temperature is 429kW. The temperature was 36.4℃.

[0075] S2: Calculate the set condensing temperature of the unit under this operating condition. The set limit temperature for circulating water is 35.6℃. The temperature is 31.3℃. The calculation method is as follows.

[0076]

[0077]

[0078] S3: Based on the deviation between the measured condensing temperature of 36.4℃ and the set value of 35.6℃, calculate and set the cooling water pump frequency. For 44Hz and cooling fan frequency The frequency is 44Hz. Simultaneously, the cooling fan frequency is stored in a variable. In, that is .

[0079] S4: Neither the sewage discharge nor the water replenishment system is activated. Check the circulating water temperature. The temperature was 32.7℃, and the water level in the collection tank was [missing information]. The value is 0.46m. Proceed to the next step.

[0080] S5: If the water level in the collection tank is 0.46m higher than the water replenishment level of 0.4m, then S6-S9 do not need to be executed, and the process ends.

[0081] During the execution of S5, S10-S13 are executed simultaneously.

[0082] S10: The circulating water temperature of 32.7℃ is greater than the set limit water temperature of 31.3℃, so execute S11.

[0083] S11: If the cooling fan frequency of 44Hz is less than the maximum value of the frequency converter range of 50Hz, then increase the cooling fan frequency to 48Hz. S12-S13 are not required; the process ends. The calculation method for the cooling fan frequency is as follows.

[0084]

[0085] After a 1-minute interval, execute S4 again. At this time, neither the sewage discharge nor the water replenishment system is activated; monitor the circulating water temperature. The temperature was 32.4℃, and the water level in the collection tank was [missing information]. It is 0.46m.

[0086] S5: If the water level in the collection tank is 0.46m higher than the water replenishment level of 0.4m, then S6-S9 do not need to be executed, and the process ends.

[0087] During the execution of S5, S10-S13 are executed simultaneously.

[0088] S10: The circulating water temperature of 32.4℃ is greater than the set limit water temperature of 31.3℃, so execute S11.

[0089] S11: If the cooling fan frequency of 48Hz is less than the maximum value of the frequency converter range of 50Hz, then increase the cooling fan frequency to 50Hz. S12-S13 are not required; the process ends. The calculation method for the cooling fan frequency is as follows.

[0090]

[0091] After a 1-minute interval, execute S4 again. At this time, neither the sewage nor the water replenishment system is activated; monitor the circulating water temperature. The temperature was 31.8℃, and the water level in the collection tank was [missing information]. It is 0.46m.

[0092] S5: If the water level in the collection tank is 0.46m higher than the water replenishment level of 0.4m, then S6-S9 do not need to be executed, and the process ends.

[0093] During the execution of S5, S10-S13 are executed simultaneously.

[0094] S10: The circulating water temperature of 31.8℃ is greater than the set limit water temperature of 31.3℃, so execute S11.

[0095] S11: The cooling fan frequency of 50Hz is equal to the maximum value of the frequency conversion range of 50Hz. Execute S12.

[0096] S12: The water level in the collection tank is 0.46m higher than the water replenishment level of 0.4m. Continue to execute S13.

[0097] S13: Simultaneously activate the sewage discharge system and the water replenishment system, with the sewage discharge volume and water replenishment volume both adjusted. It is 0.39m 3 And calculate the calcium and magnesium ion concentrations in the circulating water system. The concentration is 391 mg / L. Update the circulating water volume after calculation. The process ends when the cooling fan frequency is set to 44Hz.

[0098]

[0099]

[0100] .

[0101] The control process for the evaporative condenser during the shutdown phase is as follows.

[0102] B1: Upon receiving a shutdown signal, prioritize stopping the operation of other components such as the compressor.

[0103] B2: Turn off the cooling fan and cooling water pump.

[0104] Under the operating conditions shown in this embodiment, the optimized control method described in this invention and the commonly used fixed-frequency control method for evaporative condensers were each tested for one hour for comparison. The results are as follows: Figure 5 As shown. The average power of the optimized control method described in this invention is 73.1kW, which is 3.2kW lower than that of the fixed-frequency control method; the average COP of the optimized control method described in this invention is 5.87, which is 4.1% higher than that of the fixed-frequency control method.

[0105] Example 3 A control system for a variable frequency evaporative condenser, employing any of the control methods described above for variable frequency evaporative condensers.

[0106] Example 4 A computer-readable storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the control methods for the variable frequency evaporative condenser described above.

[0107] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A control method for a variable frequency evaporative condenser, characterized in that, Stable operation phase Includes the following steps: S1: Each interval Time, measuring ambient wet-bulb temperature Water replenishment temperature Heating capacity of the unit and measured condensation temperature ; S2: Based on ambient wet-bulb temperature Heating capacity of the unit The computer group's set condensing temperature and the set limit temperature of circulating water ; S3: Based on the measured condensation temperature With set condensation temperature Calculate and set the cooling water pump frequency based on the deviation. and cooling fan frequency After the calculation is completed, the cooling fan frequency will be... Stored in variables In, that is ; S4: Every interval The timer determines whether both the sewage and water replenishment systems are not activated; if not, the process ends. If so, then check the circulating water temperature. and water level in the collection tank Proceed to the next step; S5: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If not, the process ends; If so, then the calcium and magnesium ion concentrations of the circulating water system can be approximated. After the calculation is completed, update the circulating water volume. ; and The calculation method is as follows: in, The bottom area of ​​the water collection tank; S6: Determine the calcium and magnesium ion concentration in the circulating water system Is it greater than the threshold? If yes, proceed to the next step; otherwise, proceed to S9. S7: Activate the sewage system and drain sewage to the water change level. ; S8: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows: in, The concentration of calcium and magnesium ions for water replenishment; S9: Turn on the water supply system and add water to the operating water level. Approximate calculation of calcium and magnesium ion concentration in circulating water system Update the circulating water volume after the calculation is complete. At the same time, the frequency of the cooling fan is set. for End the process; and The calculation method is as follows: During the execution of S5-S9, S10-S13 are executed simultaneously; S10: Determine the circulating water temperature Is it greater than the set limit water temperature? If no, the process ends; if yes, proceed to the next step. S11: Determine the frequency of the cooling fan Is it equal to the maximum value of the frequency conversion range of the cooling fan? If yes, proceed to the next step; if no, increase the cooling fan frequency and end the process. S12: Determine the water level in the collection tank Is it less than or equal to the water replenishment level? If no, proceed to the next step; if yes, end the process. S13: Simultaneously activate the sewage discharge system and the water replenishment system, with both sewage discharge and water replenishment capacities set at [value missing]. And approximately calculate the calcium and magnesium ion concentrations in the circulating water system. Update the circulating water volume after the calculation is complete. Meanwhile, the frequency of the cooling fan for And end the process; and The calculation method is as follows: In the formula, This is the proportionality coefficient; Among them, each interval Re-execute S1 at each interval. At that time, S4 will be re-executed.

2. The control method for a variable frequency evaporative condenser according to claim 1, characterized in that, In S2: the condensation temperature is set. The calculation method is as follows: in, , is a coefficient.

3. The control method for a variable frequency evaporative condenser according to claim 2, characterized in that, In S2: the set limit temperature of the circulating water is set. The calculation method is as follows: in, , is a coefficient.

4. The control method for a variable frequency evaporative condenser according to claim 1, characterized in that, In S3: Calculate the cooling water pump frequency. , ,if Then set the cooling water pump frequency. ;if Then set the cooling water pump frequency. The frequency conversion range of the cooling water pump is limited to... - , This is the proportional control coefficient.

5. The control method for a variable frequency evaporative condenser according to claim 4, characterized in that, In S3: Calculate the cooling fan frequency. , ,if Then set the cooling fan frequency. ;if Then set the cooling fan frequency. The frequency conversion range of the cooling fan is limited to... - , This is the proportional control coefficient.

6. The control method for a variable frequency evaporative condenser according to claim 5, characterized in that, In S11: Cooling fan frequency The calculation method is as follows: ， in, is a coefficient.

7. The control method for a variable frequency evaporative condenser according to any one of claims 1-6, characterized in that, The power-on process includes the following steps: A1: After receiving the power-on signal, determine whether the downtime exceeds the set value. If no, proceed directly to A4; if yes, proceed to the next step. A2: Turn on the drainage system to completely drain all the water in the collection tank; A3: Turn on the water replenishment system and add water to the operating water level. Initialize the calcium and magnesium ion concentration of the circulating water system for Initialize circulating water volume ; A4: Turn on the cooling fan and cooling water pump, and set them to run at their rated frequencies; A5: Turn on the compressor.

8. The control method for a variable frequency evaporative condenser according to claim 7, characterized in that, The shutdown process includes the following steps: B1: Upon receiving a shutdown signal, the compressor stops running; B2: Turn off the cooling fan and cooling water pump.

9. A control system for a variable frequency evaporative condenser, characterized in that, The control method for the variable frequency evaporative condenser as described in any one of claims 1-8 is adopted.

10. A computer-readable storage medium, characterized in that, The device includes a stored computer program, wherein, when the computer program is executed, it controls the device containing the computer-readable storage medium to perform the control method for the variable frequency evaporative condenser as described in any one of claims 1-8.

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