A control method, system and computer-readable storage medium for the working state of a plate heat exchanger

Abstract

The present invention relates to a control method, system and computer-readable storage medium for the working state of a plate heat exchanger, the method comprising: S2, collecting the inlet and outlet temperatures T1 and T2 of the liquid side of the plate heat exchanger, and obtaining the temperature difference; S3, judging whether the temperature difference is greater than a threshold value; if so, going to step S4; if not, going to step S5; S4, collecting the temperature T3 of the water side outlet, and judging whether T3 is greater than a threshold value; if not, going to step S6; S5, judging whether the temperature T2 of the liquid side outlet is greater than a threshold value; if so, going to step S7; S6, judging whether the first-order derivative change of the temperature T3 in adjacent collection cycles is greater than a threshold value; if not, increasing the flow rate of the liquid pump; S7, judging whether the first-order derivative change of the temperature T2 in adjacent collection cycles is greater than a threshold value; if so, increasing the flow rate of the liquid pump. The present invention realizes accurate identification and control of the operating state of the plate heat exchanger.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent control technology, and specifically relates to a control method and system for the working state of a plate heat exchanger and a computer-readable storage medium. Background Art

[0002] The liquid cooling coolant is heat exchanged with the plate heat exchanger outside the liquid cooling cabinet to achieve cooling of the liquid cooling coolant. At present, most of the cooling water is heat exchanged with the liquid cooling coolant through the plate heat exchanger. Among them, the inlet and outlet of the liquid cooling coolant at the plate heat exchanger are called the liquid side inlet and liquid side outlet, and the inlet and outlet of the cooling water at the plate heat exchanger are called the water side inlet and water side outlet.

[0003] As we all know, the heat exchange efficiency of the plate heat exchanger is very high, but the gap in the heat exchange space is very small, which makes it easy to get blocked, affecting the reliability of the heat exchange.

[0004] Among them, the scaling of circulating water can easily cause the heat exchanger to be blocked. The main reason for the formation of scale is that the water contains calcium and magnesium salts with low solubility. Their solubility decreases as the water temperature rises, and they become insoluble salts. These insoluble salts have a great impact on the heat exchange effect of the heat exchanger.

[0005] In addition, the inner wall of the pipe is rusted and enters the heat exchanger with the circulating water, which is easy to cause blockage. Especially when the heat exchanger stops running, the rusting speed will be accelerated.

[0006] At present, the pressure sensor or flow sensor installed on the pipeline detects the pressure change or flow change, and then determines whether the plate heat exchanger is blocked. However, this judgment method has a lag, and it is often blocked or about to be blocked. Therefore, it is impossible to accurately detect the blockage during the working process, so as to make a prediction in advance and take relevant actions. Summary of the invention

[0007] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the objects of the present invention is to at least solve one or more of the above-mentioned problems in the prior art. In other words, one of the objects of the present invention is to provide a control method, system and computer-readable storage medium for the working state of a plate heat exchanger that meet one or more of the above-mentioned requirements.

[0008] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0009] A method for controlling the working state of a plate heat exchanger, wherein the liquid side inlet and the liquid side outlet of the plate heat exchanger are respectively connected to the inlet and outlet of the liquid cooling liquid of a liquid cooling cabinet to form a circulating flow path of the liquid cooling liquid, and the circulating flow path of the liquid cooling liquid is provided with a liquid pump; the water side inlet and the water side outlet of the plate heat exchanger are respectively connected to the water outlet and the water inlet of a dry cooler to form a circulating flow path of cooling water, and the circulating flow path of the cooling water is provided with a water pump, and the control method comprises the following steps:

[0010] S1, liquid cooling cabinet is turned on and running;

[0011] S2, collecting the temperature T1 of the liquid side inlet and the temperature T2 of the liquid side outlet of the plate heat exchanger, and obtaining the temperature difference ΔT between the two;

[0012] S3, determining whether the temperature difference ΔT is greater than a first preset threshold; if so, proceeding to step S4; if not, proceeding to step S5;

[0013] S4, collecting the temperature T3 of the water side outlet of the plate heat exchanger, and determining whether the temperature T3 is greater than a second preset threshold; if so, the heat exchange of the plate heat exchanger is normal, and the process goes to step S2; if not, the process goes to step S6;

[0014] S5, determine whether the temperature T2 of the liquid side outlet is greater than the third preset threshold; if so, go to step S7; if not, the plate heat exchanger is heat exchanging normally, go to step S2;

[0015] S6, judging whether the first-order derivative change of the temperature T3 in the adjacent collection period is greater than the fourth preset threshold; if so, the heat exchange of the plate heat exchanger is normal, and the process goes to step S2; if not, the flow rate of the liquid pump is increased, and the process goes to step S2;

[0016] S7, determine whether the first-order derivative change of the temperature T2 in adjacent collection cycles is greater than the fifth preset threshold; if so, increase the flow rate of the liquid pump and go to step S2; if not, the plate heat exchanger is normal and go to step S2.

[0017] As a preferred solution, the first preset threshold is 3-5°C, the second preset threshold is the ambient temperature T0+B, B is 2-8°C, and the third preset threshold is 40-50°C.

[0018] As a preferred solution, the fourth preset threshold and the fifth preset threshold are both -0.1 to 0.1.

[0019] As a preferred solution, in steps S6 and S7, the flow rate of the liquid pump is increased by 1 to 10%.

[0020] The present invention also provides a method for controlling the working state of a plate heat exchanger, wherein the liquid side inlet and the liquid side outlet of the plate heat exchanger are respectively connected to the inlet and outlet of the liquid cooling liquid of the liquid cooling cabinet to form a circulating flow path of the liquid cooling liquid, and the circulating flow path of the liquid cooling liquid is provided with a liquid pump; the water side inlet and the water side outlet of the plate heat exchanger are respectively connected to the water outlet and the water inlet of the dry cooler to form a circulating flow path of the cooling water, and the circulating flow path of the cooling water is provided with a water pump, and the control method comprises the following steps:

[0021] S1, liquid cooling cabinet is turned on and running;

[0022] S2, collecting the temperature T1 of the water side inlet and the temperature T2 of the water side outlet of the plate heat exchanger, and obtaining the temperature difference ΔT between the two;

[0023] S3, determining whether the temperature difference ΔT is greater than a first preset threshold; if so, proceeding to step S4; if not, proceeding to step S5;

[0024] S4, collecting the temperature T3 of the liquid side outlet of the plate heat exchanger, and determining whether the temperature T3 is greater than a second preset threshold; if so, proceeding to step S6; if not, the plate heat exchanger is heat exchanging normally, and proceeding to step S2;

[0025] S5, determine whether the temperature T2 of the water side outlet is greater than the third preset threshold; if so, go to step S7; if not, the plate heat exchanger is heat exchanging normally, go to step S2;

[0026] S6, judging whether the first-order derivative change of the temperature T3 in the adjacent collection period is greater than the fourth preset threshold; if so, increasing the flow rate of the water pump and going to step S2; if not, the heat exchange of the plate heat exchanger is normal, and going to step S2;

[0027] S7, determine whether the first-order derivative change of the temperature T3 in adjacent collection cycles is greater than the fifth preset threshold; if so, increase the flow rate of the water pump and go to step S2; if not, the plate heat exchanger is normally exchanging heat, and go to step S2.

[0028] As a preferred solution, the first preset threshold is 2-8°C, the second preset threshold is the ambient temperature T0+B, B is 2-8°C, and the third preset threshold is 40-50°C.

[0029] As a preferred solution, the fourth preset threshold and the fifth preset threshold are both -0.15 to 0.15.

[0030] As a preferred solution, in steps S6 and S7, the flow rate of the liquid pump is increased by 1 to 15%.

[0031] The present invention further provides a control system for the working state of a plate heat exchanger, applying the control method described in any of the above schemes, the control system comprising:

[0032] A collection module is used to collect temperature T1, temperature T2, temperature difference ΔT, temperature T3, first-order derivative changes of temperature T3 in adjacent collection cycles, and first-order derivative changes of temperature T2 in adjacent collection cycles;

[0033] A judgment module, used in the judgment step of the control method to obtain a corresponding judgment result;

[0034] The control module is used to execute corresponding subsequent steps according to the judgment result.

[0035] The present invention also provides a computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium. When the instructions are executed on a computer, the computer executes the control method described in any of the above schemes.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Through the cross-checking of liquid side temperature and water side temperature, the operating status of the plate heat exchanger can be accurately identified;

[0038] 2. Set a threshold value based on the temperature difference between the inlet and outlet of the liquid side to determine whether there is an abnormality in the heat exchange on the liquid side. Combine the outlet temperatures of the liquid side and the water side to determine the heat exchange status on both sides of the heat exchanger.

[0039] 3. Through the relationship between the outlet temperature of the liquid side or water side and the threshold, determine whether the outlet temperature is abnormal. Combined with the first-order derivative change of the temperature, determine whether the temperature rises or falls, and further determine the operating status of the heat exchanger for accurate identification;

[0040] 4. Through periodic detection and judgment, the online and timely detection and control of the data center are realized, which improves the effectiveness of intelligent control and timely feedback.

[0041] 5. The present invention accurately identifies the operating status of the heat exchanger through the temperature changes on the liquid side and the water side of the plate heat exchanger, accurately determines which side is blocked, and compensates for it, thereby achieving precise control of the equipment and improving reliability;

[0042] 6. By judging the first-order derivative of the outlet temperature on the liquid side or water side, the temperature and its temperature change trend can be detected in real time, and prediction and precise control can be achieved;

[0043] 7. Make a preliminary judgment based on the temperature changes and temperature difference changes on the liquid side and the water side, and combine the judgment of the threshold and its first-order derivative to achieve accurate judgment and control compensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a schematic diagram of a liquid cooling system according to Embodiment 1 of the present invention;

[0045] Figure 2 is a flow chart of a method for controlling the working state of a plate heat exchanger according to Example 1 of the present invention;

[0046] Figure 3 It is a module architecture diagram of a control system for the working state of a plate heat exchanger according to Example 1 of the present invention;

[0047] Figure 4 It is a flow chart of a method for controlling the working state of a plate heat exchanger according to Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0048] In order to more clearly illustrate the embodiments of the present invention, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings and other implementation methods can be obtained based on these accompanying drawings without creative work.

[0049] Embodiment 1:

[0050] like Figure 1 As shown, the liquid cooling system of this embodiment includes a liquid cooling cabinet, a plate heat exchanger (referred to as heat exchanger) and a dry cooler (referred to as dry cooler). Among them, the liquid side inlet and liquid side outlet of the plate heat exchanger are respectively connected to the inlet and outlet of the liquid cooling coolant of the liquid cooling cabinet to form a circulating flow path of the liquid cooling coolant (referred to as liquid path), and the circulating flow path of the liquid cooling coolant is provided with a liquid pump; the water side inlet and water side outlet of the plate heat exchanger are respectively connected to the water outlet and water inlet of the dry cooler to form a circulating flow path of the cooling water (referred to as water path), and the circulating flow path of the cooling water is provided with a water pump. The cooling water is used to perform heat exchange with the liquid cooling coolant to realize the circulating liquid cooling function of the liquid cooling coolant. Based on the liquid cooling system of this embodiment, the control method of the working state of its plate heat exchanger is described in detail below.

[0051] like Figure 2 As shown, the method for controlling the working state of the plate heat exchanger of this embodiment includes the following steps:

[0052] 1. The liquid cooling cabinet is turned on and running;

[0053] 2. Detect the inlet and outlet temperatures T1, T2 and the temperature difference ΔT1 of the liquid side of the heat exchanger;

[0054] 3. Determine the relationship between the inlet and outlet temperature difference of the heat exchanger liquid side and the threshold value A, that is, determine whether the inlet and outlet temperature difference of the heat exchanger liquid side is greater than the threshold value A (if (f (ΔT1)> A, 0, 1); wherein the threshold value A is 3-5 ° C, 0 represents the judgment result is no, 1 represents the judgment result is yes, the same below, and no further description is given;

[0055] 4. If ΔT1>A, it indicates that the temperature difference on the liquid side is too high. It is necessary to further detect the water side outlet temperature T4 of the heat exchanger and determine the relationship between the water side outlet temperature and the threshold value M, that is, determine whether the water side outlet temperature T4 is greater than the threshold value M (if (f (T4)>M,0,1)); where M=ambient temperature T0+B, B is 2-8℃.

[0056] If ΔT1≤A, it indicates that the temperature difference on the liquid side is too low, and go to step 8;

[0057] 5. If T4>M, it means that the water side outlet temperature is normal, and the heat exchange is normal, and the test of the inlet and outlet temperatures and the temperature difference of the liquid side of the heat exchanger is continued; if T4≤M, it means that the water side outlet temperature is slightly low, and further test and judge the relationship between the first-order derivative change of T4 and the threshold value X in the adjacent collection period; the value range of X is -0.1-0.1; the collection period is the period of temperature detection, for example, 1 minute.

[0058] 6. If the first-order derivative of T4 is greater than the threshold value X, it means that the outlet water temperature changes normally, and the heat exchanger is normal. Return to continue the detection of the inlet and outlet temperatures and their temperature difference on the liquid side of the heat exchanger;

[0059] 7. If the first-order derivative of T4 is less than or equal to the threshold value X, it means that the outlet water temperature changes abnormally and is in a declining stage, and there is a slight blockage on the liquid side of the heat exchanger. To compensate for the flow, the liquid pump flow + P, the value range of P is 1%-10% (preferably 2%-10%), and then return to continue to detect the inlet and outlet temperatures and the temperature difference of the liquid side of the heat exchanger.

[0060] 8. Further detect the liquid side outlet temperature T2 of the heat exchanger, and determine the relationship between the liquid side outlet temperature T2 and the threshold value N, that is, determine whether the liquid side outlet temperature T2 is greater than the threshold value N (if (f (T2)> N, 0, 1)); wherein N is 40-50 ° C;

[0061] 9. If T2 is less than or equal to N, it means that the liquid side outlet temperature is normal, and the heat exchange is normal. Return to continue testing the liquid side inlet and outlet temperatures and their temperature difference of the heat exchanger;

[0062] 10. If T2>N, it means that the liquid side outlet temperature is too high, then the relationship between the first-order derivative of the temperature T2 of the adjacent acquisition cycle and the threshold value X is determined, that is, whether the first-order derivative of the temperature T2 of the adjacent acquisition cycle is greater than the threshold value X (if (f (f (T2))>X, 0, 1)), where X is -0.1-0.1;

[0063] 11. If the first-order derivative of T2 is less than or equal to the threshold value X, it means that the outlet water temperature changes normally, and the heat exchanger is normal. Return to continue the detection of the inlet and outlet temperatures and their temperature difference on the liquid side of the heat exchanger;

[0064] 12. If the first-order derivative of T4 is greater than the threshold value X, it means that the liquid side outlet temperature changes abnormally and is in the rising stage, then there is a slight blockage on the liquid side of the heat exchanger. To compensate for the flow, the liquid pump flow + Q, the value range of Q is 1%-10%, and the heat exchanger liquid side inlet and outlet temperatures and their temperature difference are returned to continue the detection.

[0065] Corresponding to the control method of the working state of the plate heat exchanger described above in this embodiment, as follows Figure 3 As shown, this embodiment also provides a control system for the working state of the plate heat exchanger, including a setting module, a collection module, a judgment module and a control module.

[0066] Among them, the setting module is used to set all thresholds, which is convenient for freely adjusting the threshold settings.

[0067] The acquisition module is used to acquire all detected temperatures and first-order derivative changes of the temperatures, specifically including temperature T1, temperature T2, temperature difference ΔT1, temperature T4, first-order derivative changes of temperature T4 in adjacent acquisition cycles, and first-order derivative changes of temperature T2 in adjacent acquisition cycles;

[0068] The judgment module is used to execute each judgment step in the above control method to obtain a corresponding judgment result;

[0069] The control module is used to execute corresponding subsequent steps according to the judgment result.

[0070] The specific execution process of the above modules can refer to the detailed description of the above control method, which will not be repeated here.

[0071] This embodiment further provides a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a computer, the computer executes the control method described in the above embodiment.

[0072] Embodiment 2:

[0073] The control method of the working state of the plate heat exchanger in this embodiment is different from that in Embodiment 1 in that:

[0074] like Figure 4 As shown, the method for controlling the working state of the plate heat exchanger of this embodiment includes the following steps:

[0075] 1. The liquid cooling cabinet is turned on and running;

[0076] 2. Detect the inlet and outlet temperatures T3 and T4 of the water side of the heat exchanger and their temperature difference ΔT2;

[0077] 3. Determine the relationship between the inlet and outlet temperature difference of the water side of the heat exchanger and the threshold value B, that is, determine whether the inlet and outlet temperature difference of the water side of the heat exchanger is greater than the threshold value B (if (f (ΔT2)> B, 0, 1); wherein the threshold value B is 2-8 ° C, 0 represents the judgment result is no, 1 represents the judgment result is yes, the same below, and no further description is given;

[0078] 4. If ΔT2>B, it indicates that the water side temperature difference is too high. It is necessary to further detect the liquid side outlet temperature T2 of the heat exchanger and determine the relationship between the liquid side outlet temperature T2 and the threshold value M1, that is, determine whether the liquid side outlet temperature T2 is greater than the threshold value M1 (if(f(T2)>M1,0,1)); where M1 is 40-50℃. If ΔT2≤B, it indicates that the water side temperature difference is slightly low, and go to step 6;

[0079] If T2≤M1, it means that the liquid side outlet temperature is normal, and the heat exchange is normal. Return to continue to detect the inlet and outlet temperatures and temperature difference of the water side of the heat exchanger;

[0080] If T2>M1, it means that the liquid side outlet temperature is too high, and then further detection is performed to determine the relationship between the first-order derivative change of T2 in adjacent acquisition cycles and the threshold value Y, that is, to determine whether the first-order derivative change of T2 is greater than the threshold value Y; Y is -0.15-0.15;

[0081] 5. If the first-order derivative of T2 is greater than the threshold value Y, it means that the liquid side outlet temperature changes abnormally, and the water side of the heat exchanger is blocked by dirt. It is necessary to increase the water pump flow to improve the heat exchange performance, that is, the water pump flow is increased by W, and the value range of W is 1%-15% (preferably 2%-15%). Return to continue to detect the inlet and outlet temperatures and temperature difference of the water side of the heat exchanger;

[0082] If the first-order derivative of T2 is less than or equal to the threshold value Y, it means that the outlet water temperature on the liquid side changes normally and is in the decreasing stage, and the heat exchanger is normal. Return to continue to detect the inlet and outlet temperatures and their temperature difference on the water side of the heat exchanger;

[0083] 6. Further determine the relationship between the water side outlet temperature T4 and the threshold value N1, that is, determine whether the water side outlet temperature T4 is greater than the threshold value N1 (if (f (T4)> N1,0,1)); wherein N1 = ambient temperature T0 + B, B is 2-8 ° C;

[0084] If T4≤N1, it means that the outlet temperature of the water side is normal, and the heat exchange is normal. Return to continue to detect the inlet and outlet temperatures and temperature difference of the water side of the heat exchanger;

[0085] If T4>N1, it means that the water side outlet temperature is too high, then further detection is performed to determine the relationship between the first-order derivative change of the liquid side outlet temperature T2 in adjacent acquisition cycles and the threshold value X, where X is -0.15-0.15, preferably -0.1-0.1;

[0086] 7. If the first-order derivative of T2 is greater than the threshold value X, it means that the liquid side outlet temperature changes abnormally, and the water side of the heat exchanger is dirty and blocked. It is necessary to increase the water pump flow to improve the heat exchange performance, that is, the water pump flow is increased by V, and the value range of V is 1%-15%; then return to detect the inlet and outlet temperatures and temperature difference of the water side of the heat exchanger;

[0087] If the first-order derivative of T2 is less than or equal to the threshold value X, it means that the outlet water temperature changes normally and is in a decreasing stage, and the heat exchanger is normal, then the inlet and outlet temperatures and the temperature difference of the water side of the heat exchanger are detected.

[0088] The control system of the working state of the plate heat exchanger of this embodiment can refer to Example 1;

[0089] The computer-readable storage medium of this embodiment stores instructions, and when the instructions are executed on a computer, the computer executes the control method described in the above embodiment.

[0090] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, according to the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the protection scope of the present invention.

Claims

1. A method for controlling the working state of a plate heat exchanger, wherein the liquid side inlet and the liquid side outlet of the plate heat exchanger are respectively connected to the inlet and outlet of the liquid cooling liquid of the liquid cooling cabinet to form a circulating flow path of the liquid cooling liquid, and the circulating flow path of the liquid cooling liquid is provided with a liquid pump; the water side inlet and the water side outlet of the plate heat exchanger are respectively connected to the water outlet and the water inlet of the dry cooler to form a circulating flow path of the cooling water, and the circulating flow path of the cooling water is provided with a water pump, characterized in that: The control method comprises the following steps: S1, liquid cooling cabinet is turned on and running; S2, collecting the temperature T1 of the liquid side inlet and the temperature T2 of the liquid side outlet of the plate heat exchanger, and obtaining the temperature difference ΔT1 between the two; S3, determining whether the temperature difference ΔT1 is greater than a first preset threshold; if so, proceeding to step S4; if not, proceeding to step S5; S4, collecting the temperature T3 of the water side outlet of the plate heat exchanger, and determining whether the temperature T3 is greater than a second preset threshold; if so, the heat exchange of the plate heat exchanger is normal, and the process goes to step S2; if not, the process goes to step S6; S5, determine whether the temperature T2 of the liquid side outlet is greater than the third preset threshold; if so, go to step S7; if not, the plate heat exchanger is heat exchanging normally, go to step S2; S6, judging whether the first-order derivative change of the temperature T3 in the adjacent collection period is greater than the fourth preset threshold; if so, the heat exchange of the plate heat exchanger is normal, and the process goes to step S2; if not, the flow rate of the liquid pump is increased, and the process goes to step S2; S7, determine whether the first-order derivative change of the temperature T2 in adjacent collection cycles is greater than the fifth preset threshold; if so, increase the flow rate of the liquid pump and go to step S2; if not, the plate heat exchanger is normal and go to step S2.

2. A method for controlling the working state of a plate heat exchanger according to claim 1, characterized in that: The first preset threshold is 3-5°C, the second preset threshold is the ambient temperature T0+B, B is 2-8°C, and the third preset threshold is 40-50°C.

3. A method for controlling the working state of a plate heat exchanger according to claim 1, characterized in that: The fourth preset threshold and the fifth preset threshold are both between -0.1 and 0.

1.

4. A method for controlling the working state of a plate heat exchanger according to claim 1, characterized in that: In the steps S6 and S7, the flow rate of the liquid pump is increased by 1 to 10%.

5. A method for controlling the working state of a plate heat exchanger, wherein the liquid side inlet and the liquid side outlet of the plate heat exchanger are respectively connected to the liquid cooling coolant inlet and outlet of the liquid cooling cabinet to form a circulating flow path of the liquid cooling coolant, and the circulating flow path of the liquid cooling coolant is provided with a liquid pump; the water side inlet and the water side outlet of the plate heat exchanger are respectively connected to the water outlet and the water inlet of the dry cooler to form a circulating flow path of the cooling water, and the circulating flow path of the cooling water is provided with a water pump, characterized in that: The control method comprises the following steps: S1, liquid cooling cabinet is turned on and running; S2, collecting the temperature T4 of the water side inlet and the temperature T3 of the water side outlet of the plate heat exchanger, and obtaining the temperature difference ΔT2 between the two; S3, determining whether the temperature difference ΔT2 is greater than a sixth preset threshold; if so, proceeding to step S4; if not, proceeding to step S5; S4, collecting the temperature T2 of the liquid side outlet of the plate heat exchanger, and determining whether the temperature T2 is greater than the seventh preset threshold; if so, proceeding to step S6; if not, the plate heat exchanger is normally exchanging heat, and proceeding to step S2; S5, determine whether the temperature T3 of the water side outlet is greater than the eighth preset threshold; if so, go to step S7; if not, the plate heat exchanger is heat exchanging normally, go to step S2; S6, judging whether the first-order derivative change of the temperature T2 in the adjacent collection period is greater than the ninth preset threshold; if so, increasing the flow rate of the water pump and going to step S2; if not, the heat exchange of the plate heat exchanger is normal, and going to step S2; S7, determine whether the first-order derivative change of the temperature T2 in adjacent collection cycles is greater than the tenth preset threshold; if so, increase the flow rate of the water pump and go to step S2; if not, the plate heat exchanger is normal and go to step S2.

6. A method for controlling the working state of a plate heat exchanger according to claim 5, characterized in that: The sixth preset threshold is 2-8°C, the seventh preset threshold is the ambient temperature T0+B, B is 2-8°C, and the eighth preset threshold is 40-50°C.

7. A method for controlling the working state of a plate heat exchanger according to claim 5, characterized in that: The ninth preset threshold and the tenth preset threshold are both -0.15 to 0.

15.

8. A method for controlling the working state of a plate heat exchanger according to claim 5, characterized in that: In steps S6 and S7, the flow rate of the water pump is increased by 1 to 15%.

9. A control system for the working state of a plate heat exchanger, using the control method according to any one of claims 1 to 4, characterized in that: The control system comprises: A collection module is used to collect temperature T1, temperature T2, temperature T3, temperature difference ΔT1, first-order derivative changes of temperature T3 in adjacent collection cycles, and first-order derivative changes of temperature T2 in adjacent collection cycles; A judgment module, used in the judgment step of the control method to obtain a corresponding judgment result; The control module is used to execute corresponding subsequent steps according to the judgment result.

10. A control system for the working state of a plate heat exchanger, using the control method according to any one of claims 5 to 8, characterized in that: The control system comprises: An acquisition module is used to acquire temperature T2, temperature T3, temperature T4, temperature difference ΔT2, and first-order derivative changes of temperature T2 in adjacent acquisition cycles; A judgment module, used in the judgment step of the control method to obtain a corresponding judgment result; The control module is used to execute corresponding subsequent steps according to the judgment result.

11. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium, characterized in that: When the instructions are executed on a computer, the computer is enabled to execute the control method according to any one of claims 1 to 8.

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