A surface air cooler anti-freezing control method, control device and surface air cooler

Abstract

The present application relates to a kind of surface condenser anti-freezing control method, control device, system and surface condenser.Therein, the surface condenser anti-freezing control method, for controlling drain valve and first heating device, include steps: S1, detect whether surface condenser is powered on;S2b, if the surface condenser is powered off, then obtain the length of time when powered off;S3b, if the length of time when powered off is greater than or equal to preset length of time, then control the drain valve opens;S4b, if the length of time when powered off is less than preset length of time, then obtain waterway temperature;S5, according to the waterway temperature, obtain basic anti-freezing mode;S6, according to the basic anti-freezing mode, obtain final anti-freezing mode;S7, according to the final anti-freezing mode, control the opening and closing of the drain valve and first heating device.The surface condenser anti-freezing control method, control device, system and surface condenser of the present application can automatically enter anti-freezing mode according to the length of time when powered off and temperature, effectively reduce the risk of water freezing pipe burst.

Description

Technical Field

[0001] This invention relates to the field of surface coolers, and in particular to a surface cooler antifreeze control method, control device, and surface cooler. Background Technology

[0002] A surface cooler is a device that uses a fluid medium with a high specific heat capacity to change the temperature and humidity of air. It is widely used in air conditioning, heat pumps, dehumidifiers, and other fields. A surface cooler consists of several pipes filled with a fluid medium. When air flows over the surface of the pipes, heat exchange occurs between the air and the fluid medium inside the pipes, thus changing the air temperature. If the temperature of the fluid medium inside the surface cooler pipes is low, the temperature of the outer wall of the pipes will be relatively low. When air flows over the pipes, water vapor in the air will condense into water upon cooling and adhere to the outer surface of the pipes, thus reducing the air humidity.

[0003] Existing surface coolers generally use water as the fluid medium. These existing surface coolers have the following drawbacks: in northern regions during winter, where ambient temperatures often drop below 0°C, the water inside the cooler's pipes is prone to freezing; once frozen, the water expands in volume, potentially causing the pipes to burst and preventing the cooler from operating normally. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a surface cooler antifreeze control method, control device, system and surface cooler, which can automatically enter the antifreeze mode according to the shutdown time and temperature, effectively reducing the risk of water freezing and bursting pipes.

[0005] A method for controlling the antifreeze function of a surface cooler, used to control a drain valve and a first heating device, includes the following steps: S1, Check if the surface cooler is powered on; S2b, If the surface cooler is turned off, obtain the shutdown duration; S3b, if the shutdown duration is greater than or equal to the preset duration, then control the drain valve to open; S4b, if the shutdown duration is less than the preset duration, then obtain the water circuit temperature; S5, Based on the water temperature, obtain the basic antifreeze mode; S6. Obtain the final antifreeze mode based on the basic antifreeze mode; S7, according to the final antifreeze mode, control the opening and closing of the drain valve and the first heating device.

[0006] The surface cooler antifreeze control method of the present invention can automatically open the drain valve and the first heating device when the water temperature is low, thereby greatly reducing the probability of water freezing in the surface cooler pipes.

[0007] Furthermore, after step S1 and before step S5, the following steps are also included: S2a, If the surface cooler is turned on, the status of the drain valve is detected; S3a, If the drain valve is in the open state, it will operate normally; S4a, if the drain valve is in the closed state, the water temperature is obtained.

[0008] Further, step S5 includes: S51, if the water temperature is less than or equal to the first threshold temperature, then the basic antifreeze mode is the advanced antifreeze mode. S52, if the water temperature is greater than the first threshold temperature and less than or equal to the second threshold temperature, then the basic antifreeze mode is the medium antifreeze mode. S53, if the water temperature is greater than the second threshold temperature and less than or equal to the third threshold temperature, then the basic antifreeze mode is the low-level antifreeze mode.

[0009] Furthermore, step S5 also includes: S54, if the water temperature is greater than the third threshold temperature and less than the fourth threshold temperature, then the basic antifreeze mode is the buffer antifreeze mode. S55, if the water temperature is greater than or equal to the fourth threshold temperature, then the basic antifreeze mode is to exit the antifreeze mode.

[0010] Further, step S6 includes: S6a1, If ​​the surface cooler is turned on, detect whether the surface cooler is in defrost mode or heating mode. S6a2, if the surface cooler is in heating mode, determine whether the first parameter meets the first preset condition; If the first parameter satisfies the first preset condition, then the final antifreeze mode is obtained based on the basic antifreeze mode and the first parameter; S6a3, if the surface cooler is in defrost mode, then determine whether the second parameter meets the second preset condition; If the second parameter satisfies the second preset condition, then the final antifreeze mode is obtained based on the basic antifreeze mode and the second parameter; If the second parameter does not meet the second preset condition, then determine whether the second parameter meets the third preset condition; if the second parameter meets the third preset condition, then switch the defrosting mode to the heating mode and return to step S6a2. S6b, if the surface cooler is turned off, or the surface cooler is turned on but not in defrost mode or heating mode, then the basic antifreeze mode is the final antifreeze mode.

[0011] Further, step S7 includes: S71, if the final antifreeze mode is a high-level antifreeze mode, control the drain valve to open and the first heating device to open. S72, if the final antifreeze mode is medium antifreeze mode, control the drain valve to open and the first heating device to close. S73, if the final antifreeze mode is a low-level antifreeze mode, control the drain valve to close and the first heating device to turn on; S74, if the final antifreeze mode is a buffer antifreeze mode, keep the state of the drain valve and the first heating device unchanged; S75, if the final antifreeze mode is to exit antifreeze mode, control the drain valve to close and the first heating device to close.

[0012] Furthermore, it is also used to control a second heating device; It also includes step S8, which controls the second heating device to turn on and off based on the antifreeze duration; Step S8 includes: S81, obtain the antifreeze duration when the final antifreeze mode is high antifreeze mode; the antifreeze duration starts counting from the time point when the final antifreeze mode is high antifreeze mode, and is reset to zero after the final antifreeze mode changes to exit antifreeze mode. S82, if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is high antifreeze mode, control the second heating device to turn on; if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is medium antifreeze mode, low antifreeze mode or buffer antifreeze mode, keep the state of the second heating device unchanged; if the antifreeze duration is 0, control the second heating device to turn off.

[0013] Furthermore, it also includes step S4b0, which is executed before step S4b: if the shutdown duration is less than a preset duration, then the water volume in the surface cooler pipe is obtained; Step S4b is replaced by: if the water volume is greater than or equal to the set water volume threshold, then obtain the water circuit temperature.

[0014] Based on the same inventive concept, the present invention provides a surface cooler antifreeze control device for controlling a drain valve and a first heating device, comprising: The shutdown detection module is used to detect whether the surface cooler is powered on. The shutdown duration acquisition module is used to acquire the shutdown duration when the surface cooler is shut down; The drain valve opening module is used to control the drain valve to open when the shutdown duration is greater than or equal to a preset duration; The water circuit temperature acquisition module is used to acquire the water circuit temperature when the shutdown time is less than a preset time. The basic antifreeze mode determination module is used to obtain the basic antifreeze mode based on the water circuit temperature. The final antifreeze mode acquisition module is used to acquire the final antifreeze mode based on the basic antifreeze mode. The control module is used to control the opening and closing of the drain valve and the first heating device according to the final antifreeze mode.

[0015] Based on the same inventive concept, the present invention provides a surface cooler, including a control device, which executes any of the above-described surface cooler antifreeze control methods to prevent the pipes of the surface cooler from freezing and cracking.

[0016] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the surface cooler antifreeze system according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the surface cooler antifreeze control device module according to Embodiment 1 of the present invention; Figure 3 This is a schematic flowchart of the surface cooler antifreeze control method according to Embodiment 1 of the present invention; Figure 4 This is a schematic diagram of step S5 of the surface cooler antifreeze control method in Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of step S6 of the surface cooler antifreeze control method in Embodiment 1 of the present invention; Figure 6 This is a schematic diagram of the surface cooler antifreeze control method according to Embodiment 2 of the present invention. Detailed Implementation

[0018] To address the issue that water in the pipes of a surface cooler may freeze and burst during winter, this invention provides a surface cooler antifreeze control method, control device, system, and surface cooler.

[0019] Example 1 Please see Figure 1 , Figure 1 This is a schematic diagram of the surface cooler antifreeze system according to Embodiment 1 of the present invention. The surface cooler antifreeze system of Embodiment 1 of the present invention includes a drain valve, a first heating device, a timer, a temperature sensor, and a control device.

[0020] The drain valve is installed at the drain outlet of the cooling coil pipe; when the drain valve is opened, the water in the cooling coil pipe will be discharged from the drain outlet.

[0021] When the surface cooler is in operation, if the drain valve is open, water enters the pipe from the inlet and exits from the outlet, keeping the pipe in a flowing state. Flowing water is less likely to freeze than stagnant water, reducing the probability of the pipe freezing and bursting. When the surface cooler is not in operation, if the drain valve is open, water will not enter the pipe from the inlet but will exit from the outlet, emptying the pipe. With no water in the pipe, there is no possibility of freezing and bursting.

[0022] The first heating device is used to heat the water in the surface cooler pipes; when the first heating device is turned on, the water temperature in the surface cooler pipes rises. In this embodiment, the first heating device is an electric auxiliary heating cable installed on the outer wall of the surface cooler pipes. In other embodiments, the first heating device may also be a thermal radiation heater or a fan heater.

[0023] The timer detects the shutdown duration of the surface cooler; the shutdown duration refers to the continuous duration during which the surface cooler is powered on but not working.

[0024] The temperature sensor detects the water temperature in the surface cooler; the water temperature refers to the temperature of the water inside the surface cooler pipes.

[0025] The control device controls the opening and closing of the drain valve and the first heating device according to the shutdown duration and water temperature.

[0026] When the surface cooler is not powered on, the control device cannot automatically control the opening and closing of the drain valve and the first heating device. Therefore, when the surface cooler is not powered on and is not used for a long time, the drain valve should be manually opened to drain the water from the surface cooler pipes. After the water in the surface cooler pipes is drained, there is no water in the pipes, and therefore no risk of water freezing and bursting the pipes.

[0027] When the surface cooler is powered on, the control device executes the surface cooler antifreeze control method of Embodiment 1 of the present invention, and automatically controls the opening and closing of the drain valve and the first heating device.

[0028] Please see Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the surface cooler antifreeze control device module according to Embodiment 1 of the present invention. Figure 3This is a schematic flowchart of the surface cooler antifreeze control method according to Embodiment 1 of the present invention. The control device includes a shutdown detection module 1, a drain valve status acquisition module 2a, a normal operation module 3a, a water circuit temperature acquisition module 4, a shutdown duration acquisition module 2b, a drain valve opening module 3b, a basic antifreeze mode judgment module 5, a final antifreeze mode acquisition module 6, and a control module 7.

[0029] The shutdown detection module 1 is used to perform step S1: detect whether the surface cooler is turned on.

[0030] The drain valve status acquisition module 2a is used to execute step S2a: if the surface cooler is turned on, the status of the drain valve is detected. The surface cooler being turned on means that the surface cooler is powered on and in operation.

[0031] The normal operation module 3a is used to execute step S3a: if step S2a detects that the drain valve is in the open state, then it operates normally and does not perform antifreeze protection.

[0032] The water circuit temperature acquisition module 4 is used to execute step S4a: if step S2a detects that the drain valve is in a closed state, then the water circuit temperature detected by the temperature sensor is acquired in real time.

[0033] When the surface cooler is in operation, it controls the opening and closing of the drain valve according to the original control logic for operating conditions, that is, controlling the opening and closing of the drain valve based on the return air temperature. If the surface cooler is in operation and the drain valve is open, it indicates that the water in the surface cooler pipes is in a flowing state. At this time, the probability of the water in the pipes freezing is very low. Therefore, the unit can operate normally without taking additional antifreeze protection measures, and the effect of preventing freezing and explosion can be achieved. If the surface cooler is in operation and the drain valve is closed, it indicates that the water in the surface cooler pipes is in a stagnant state, and there is still a possibility of freezing. Therefore, it is necessary to further obtain the water temperature.

[0034] The shutdown duration acquisition module 2b is used to execute step S2b: if the surface cooler is shut down, then acquire the shutdown duration detected by the timer. The surface cooler being shut down means that the surface cooler is powered on but not in operation.

[0035] The drain valve opening module 3b is used to execute step S3b: if the shutdown duration obtained in step S2b is greater than or equal to a preset duration, then the drain valve is controlled to open. A shutdown duration greater than or equal to the preset duration indicates that the surface cooler has not been in operation for a long time. In this case, the control device controls the drain valve to open, allowing water to drain from the surface cooler pipes to prevent the pipes from freezing and bursting. In one embodiment, the preset duration is 7 days.

[0036] The water temperature acquisition module 4 is used to execute step S4b: if the shutdown duration obtained in step S2b is less than a preset duration, the water temperature detected by the temperature sensor is acquired in real time. When the surface cooler is not in operation, the water in the pipe is in a static state and may freeze, so it is necessary to further acquire the water temperature.

[0037] The basic antifreeze mode determination module 5 is used to execute step S5: obtain the basic antifreeze mode based on the water circuit temperature. The basic antifreeze modes, from high to low, include: high antifreeze mode, medium antifreeze mode, low antifreeze mode, buffer antifreeze mode, and exit antifreeze mode.

[0038] Specifically, please refer to Figure 4 , Figure 4 This is a schematic diagram of step S5 of the surface cooler antifreeze control method according to Embodiment 1 of the present invention. The basic antifreeze mode judgment module 5 includes: a high-level antifreeze mode judgment unit 51, a medium-level antifreeze mode judgment unit 52, a low-level antifreeze mode judgment unit 53, a buffer antifreeze mode judgment unit 54, and an exit antifreeze mode judgment unit 55.

[0039] The advanced antifreeze mode determination unit 51 is used to execute step S51: if the water circuit temperature is less than or equal to a first threshold temperature, then the basic antifreeze mode is an advanced antifreeze mode. In one embodiment, the first threshold temperature is 1°C.

[0040] The medium antifreeze mode determination unit 52 is used to execute step S52: if the water circuit temperature is greater than the first threshold temperature and less than or equal to the second threshold temperature, then the basic antifreeze mode is the medium antifreeze mode. In one embodiment, the second threshold temperature is 3°C.

[0041] The low-level antifreeze mode determination unit 53 is used to execute step S53: if the water circuit temperature is greater than the second threshold temperature and less than or equal to the third threshold temperature, then the basic antifreeze mode is the low-level antifreeze mode. In one embodiment, the third threshold temperature is 5°C.

[0042] The buffer antifreeze mode determination unit 54 is used to execute step S54: if the water temperature is greater than the third threshold temperature and less than the fourth threshold temperature, then the basic antifreeze mode is the buffer antifreeze mode. In one embodiment, the fourth threshold temperature is 8°C. The buffer antifreeze mode is set to prevent repeated temperature fluctuations from causing the first heating device to frequently turn on and off, thus burdening the drive circuit of the first heating device.

[0043] The exit antifreeze mode determination unit 55 is used to execute step S55: if the water circuit temperature is greater than or equal to the fourth threshold temperature, then the basic antifreeze mode is exit antifreeze mode.

[0044] Specifically, please refer to Figure 5 , Figure 5 This is a schematic flowchart of step S6 of the surface cooler antifreeze control method according to Embodiment 1 of the present invention. The final antifreeze mode acquisition module 6 is used to execute step S6: acquiring the final antifreeze mode based on the basic antifreeze mode. The final antifreeze modes, from high to low, include: high antifreeze mode, medium antifreeze mode, low antifreeze mode, buffer antifreeze mode, and exit antifreeze mode.

[0045] Specifically, the final antifreeze mode acquisition module 6 includes: a mode detection unit, a heating mode adjustment unit, a defrost mode adjustment unit, and other mode adjustment units.

[0046] The mode detection unit is used to perform step S6a1: if the surface cooler is turned on, it detects whether the surface cooler is in heating mode or defrosting mode.

[0047] The heating mode adjustment unit is used to execute step S6a2: if the surface cooler is in heating mode, it determines whether the first parameter meets the first preset condition; if the first parameter meets the first preset condition, it obtains the final antifreeze mode based on the basic antifreeze mode and the first parameter. In one embodiment, the first parameter may be: heating power, heating capacity, or heating time; the first preset condition may be: the first parameter reaches a set first adjustment threshold; obtaining the final antifreeze mode based on the basic antifreeze mode and the first parameter may be: subtracting one level from the basic antifreeze mode.

[0048] The meaning of "subtract one level from the basic antifreeze mode" is as follows: if the basic antifreeze mode obtained in step S5 is high-level antifreeze mode, then the final antifreeze mode is medium-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is medium-level antifreeze mode, then the final antifreeze mode is low-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is low-level antifreeze mode, then the final antifreeze mode is buffered antifreeze mode; if the basic antifreeze mode obtained in step S5 is buffered antifreeze mode, then the final antifreeze mode is exited antifreeze mode; if the basic antifreeze mode obtained in step S5 is exited antifreeze mode, then the final antifreeze mode is still exited antifreeze mode.

[0049] In heating mode, the water in the cooling coil pipes tends to heat up, so a more advanced antifreeze protection mode is not needed. Therefore, in this embodiment, the final antifreeze mode is obtained by subtracting one level from the basic antifreeze mode. In other embodiments, those skilled in the art can set different methods for obtaining the final antifreeze mode according to their needs.

[0050] The defrost mode adjustment unit is used to execute step S6a3: if the surface cooler is in defrost mode, it determines whether the second parameter meets the second preset condition; if the second parameter meets the second preset condition, it obtains the final antifreeze mode based on the basic antifreeze mode and the second parameter; if the second parameter does not meet the second preset condition, it determines whether the second parameter meets the third preset condition; if the second parameter meets the third preset condition, it switches the defrost mode to the heating mode and calls the heating mode adjustment unit. In one embodiment, the second parameter can be: defrost progress, defrost amount, or defrost time; the second preset condition can be: the second parameter is less than a set second adjustment threshold; obtaining the final antifreeze mode based on the basic antifreeze mode and the second parameter can be: adding one level based on the basic antifreeze mode; the third preset condition can be: the second parameter is greater than a set third adjustment threshold.

[0051] The meaning of "adding one level on the basis of the basic antifreeze mode" is as follows: if the basic antifreeze mode obtained in step S5 is high-level antifreeze mode, then the final antifreeze mode is still high-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is medium-level antifreeze mode, then the final antifreeze mode is high-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is low-level antifreeze mode, then the final antifreeze mode is medium-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is buffered antifreeze mode, then the final antifreeze mode is low-level antifreeze mode; if the basic antifreeze mode obtained in step S5 is exit antifreeze mode, then the final antifreeze mode is buffered antifreeze mode.

[0052] In defrost mode, the water in the cooler pipes tends to cool down. If the defrost progress or defrost time is less than the set second adjustment threshold, it means that the defrost mode needs to be maintained for a relatively long time, and the water temperature will continue to drop, posing a high risk of freezing. Therefore, a higher level of antifreeze mode is required. If the defrost progress or defrost time is greater than the set third adjustment threshold, it means that defrosting is about to be completed or has already been completed. At this point, switching from defrost mode to heating mode can reverse the trend of water temperature drop and reduce the risk of freezing.

[0053] The other mode adjustment unit is used to execute step S6b: if the surface cooler is turned off, or the surface cooler is turned on but not in defrost mode or heating mode, or the surface cooler is in heating mode but the first parameter does not meet the first preset condition, or the surface cooler is in defrost mode but the second parameter does not meet either the second preset condition or the third preset condition, then the basic antifreeze mode is the final antifreeze mode.

[0054] The control module 7 is used to execute S7: control the opening and closing of the drain valve and the first heating device according to the final antifreeze mode.

[0055] Specifically, the control module 7 includes: a high-level antifreeze mode control unit, a medium-level antifreeze mode control unit, a low-level antifreeze mode control unit, a buffer antifreeze mode control unit, and an exit antifreeze mode control unit.

[0056] The advanced antifreeze mode control unit is used to execute step S71: if the final antifreeze mode is advanced antifreeze mode, control the drain valve to open and the first heating device to open.

[0057] The medium antifreeze mode control unit is used to execute step S72: if the final antifreeze mode is medium antifreeze mode, control the drain valve to open and the first heating device to close.

[0058] The low-level antifreeze mode control unit is used to execute step S73: if the final antifreeze mode is low-level antifreeze mode, control the drain valve to close and the first heating device to turn on.

[0059] The buffer antifreeze mode control unit is used to execute step S74: if the final antifreeze mode is the buffer antifreeze mode, keep the state of the drain valve and the first heating device unchanged.

[0060] The exit antifreeze mode control unit is used to execute step S75: if the final antifreeze mode is exit antifreeze mode, control the drain valve to close and the first heating device to close.

[0061] Furthermore, when the control device controls the first heating device to turn on, the control device also controls the heating power of the first heating device according to the water temperature, so that the lower the water temperature, the higher the heating power of the first heating device. In one embodiment, when the control device controls the first heating device to turn on, the control device controls the heating power of the first heating device according to the following formula: , In the formula, t represents the water temperature, P represents the heating power of the first heating device, and a, b, and c are all set constants.

[0062] Example 2 Please see Figure 6 , Figure 6This is a schematic flowchart of the surface cooler antifreeze control method according to Embodiment 2 of the present invention. The surface cooler antifreeze system of Embodiment 2 of the present invention is basically the same as that of Embodiment 1, except that: the surface cooler antifreeze system of Embodiment 2 of the present invention further includes a water volume sensor; the water volume sensor is used to acquire the water volume in the surface cooler pipes. The control device of Embodiment 2 of the present invention further includes a water volume acquisition module.

[0063] The water volume acquisition module is used to execute step S4a0 before step S4a: if step S2a detects that the drain valve is in a closed state, then the water volume in the surface cooler pipe detected by the water volume sensor is acquired in real time.

[0064] The water volume acquisition module is also used to execute step S4b0 before step S4b: if the shutdown duration obtained in step S2b is less than the preset duration, then the water volume in the surface cooler pipe detected by the water volume sensor is acquired in real time.

[0065] In Embodiment 2, step S4a executed by the water path temperature acquisition module 4 is replaced by: if the water volume detected in step S4a0 is greater than or equal to a set water volume threshold, then the water path temperature detected by the temperature sensor is acquired in real time. Step S4b executed by the water path temperature acquisition module 4 is replaced by: if the water volume detected in step S4b0 is greater than or equal to a set water volume threshold, then the water path temperature detected by the temperature sensor is acquired in real time.

[0066] When the water volume is less than the set water volume threshold, even if the water in the surface cooler pipes freezes, the volume of the ice will still be less than the pipe's capacity, resulting in a low probability of the pipes bursting. Therefore, when the water volume is less than the set water volume threshold, it is not necessary to obtain the water temperature to determine whether to enter the antifreeze mode. Steps S4a / S4b are only executed when the water volume is greater than or equal to the set water volume threshold. The water volume threshold is set based on the pipe's capacity, ensuring that even if all the water freezes when the water volume is less than the threshold, the volume of the ice will not exceed the pipe's capacity.

[0067] Furthermore, under the condition that the heating power of the first heating device remains constant, the smaller the water volume in the pipe, the faster the water heats up, and the less heating power is needed. Therefore, when the water volume is greater than or equal to a set water volume threshold, if the control device controls the first heating device to turn on, the control device also controls the heating power of the first heating device according to the water volume, so that the greater the water volume, the higher the heating power of the first heating device.

[0068] Furthermore, since the heating power of the first heating device is affected by both the water temperature and the water volume, the control device calculates the heating power of the first heating device according to the following formula: In the formula, t represents the water temperature, v represents the water volume, v0 represents the set water volume threshold, P represents the heating power of the first heating device, and a, b, c and d are all set constants.

[0069] Example 3 The surface cooler antifreeze system of Embodiment 3 of the present invention is basically the same as that of Embodiment 1, except that the surface cooler antifreeze system of Embodiment 3 further includes a second heating device. The opening and closing of the second heating device is also controlled by the control device. In one embodiment, the heating power of the second heating device is greater than that of the first heating device.

[0070] The control device further includes a second heating device control module; the second heating device control module is used to execute step S8: control the opening and closing of the second heating device according to the antifreeze duration.

[0071] Specifically, the second heating device control module includes: an antifreeze duration acquisition unit and a second heating device control unit.

[0072] The antifreeze duration acquisition unit is used to perform step S81: acquire the antifreeze duration when the final antifreeze mode is high antifreeze mode in real time through the timer; the antifreeze duration starts counting from the time point when the final antifreeze mode is high antifreeze mode, and is reset to zero after the final antifreeze mode changes to exit antifreeze mode.

[0073] The second heating device control unit is configured to execute step S82: if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is a high antifreeze mode, control the second heating device to turn on; if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is a medium antifreeze mode, a low antifreeze mode, or a buffer antifreeze mode, keep the state of the second heating device unchanged; if the antifreeze duration is 0, control the second heating device to turn off.

[0074] Furthermore, when the control device controls the second heating device to turn on, the lower the water temperature, the higher the heating power of the second heating device.

[0075] When the environment is extremely cold, the water in the surface cooler pipes cools down rapidly. Even if the first heating device is heating at full power, the rate of heating may not keep up with the rate of cooling, resulting in the water temperature remaining below or equal to the first threshold temperature for an extended period, i.e., it remains in a high-level anti-freeze mode. Therefore, when the anti-freeze duration exceeds the set anti-freeze time threshold and the water temperature is below or equal to the first threshold temperature, the second heating device is activated. Because the second heating device has a high heating power, the rate of heating generally does not lag behind the rate of cooling after it is activated, and the water in the surface cooler pipes slowly heats up, exceeding the first threshold temperature. When the water temperature exceeds the first threshold temperature but is below the fourth threshold temperature, the anti-freeze duration is not reset, so the second heating device remains on, and the water in the surface cooler pipes continues to heat up. When the water temperature reaches the fourth threshold temperature, the anti-freeze duration is reset to zero, and the second heating device is turned off. The second heating device is activated again when the water temperature drops to or below the first threshold temperature again, and the anti-freeze duration exceeds the set anti-freeze time threshold. The second heating device serves as a backup energy source to address situations where the first heating device alone cannot reverse the temperature drop in extreme cold weather.

[0076] The surface cooler antifreeze system of this invention, by incorporating a drain valve, a first heating device, and a control device, automatically activates the drain valve and the first heating device when the water temperature is low, thereby significantly reducing the probability of water freezing in the surface cooler pipes. Furthermore, the surface cooler antifreeze control method of this invention sets three levels of antifreeze modes based on temperature gradients, making antifreeze control more precise and more energy-efficient and environmentally friendly than a single-level antifreeze mode. Furthermore, in addition to the three levels of antifreeze modes, the surface cooler antifreeze control method of this invention also includes a buffer antifreeze mode, effectively avoiding the problem of frequent entry / exit of antifreeze modes due to temperature fluctuations. Furthermore, this invention also determines whether to enter the antifreeze mode based on water volume, and does not enter the antifreeze mode when the water volume is below a threshold, saving energy and improving the cost-effectiveness of control. Furthermore, this invention also considers the possibility that the heating power of the first heating device is insufficient in extreme low-temperature weather, and incorporates a backup second heating device, improving the reliability of antifreeze. Furthermore, this invention also takes into account the temperature change trend of the surface cooler in heating mode or defrosting mode, and designs a method to obtain the final antifreeze mode based on the basic antifreeze mode, thereby improving the intelligence of the control.

[0077] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A method for controlling the antifreeze function of a surface cooler, used to control a drain valve and a first heating device, characterized in that, Including the following steps: S1, Check if the surface cooler is powered on; S2b, If the surface cooler is turned off, obtain the shutdown duration; S3b, if the shutdown duration is greater than or equal to the preset duration, then control the drain valve to open; S4b, if the shutdown duration is less than the preset duration, then obtain the water circuit temperature; S5, Based on the water temperature, obtain the basic antifreeze mode; S6. Obtain the final antifreeze mode based on the basic antifreeze mode; Specifically, step S6 includes: S6a1, If ​​the surface cooler is turned on, detect whether the surface cooler is in defrost mode or heating mode. S6a2, if the surface cooler is in heating mode, determine whether the first parameter meets the first preset condition; the first parameter is heating power, heating capacity or heating time; the first preset condition is that the first parameter reaches a set first adjustment threshold. If the first parameter satisfies the first preset condition, then the final antifreeze mode is obtained based on the basic antifreeze mode and the first parameter; that is, one level is subtracted from the basic antifreeze mode. S6a3, if the surface cooler is in defrost mode, then determine whether the second parameter meets the second preset condition; the second parameter is defrost progress, defrost amount or defrost time; the second preset condition is that the second parameter is less than the set second adjustment threshold. If the second parameter satisfies the second preset condition, then the final antifreeze mode is obtained based on the basic antifreeze mode and the second parameter; that is, an additional level is added based on the basic antifreeze mode. If the second parameter does not meet the second preset condition, then determine whether the second parameter meets the third preset condition; if the second parameter meets the third preset condition, then switch the defrosting mode to the heating mode and return to step S6a2; the third preset condition is that the second parameter is greater than the set third adjustment threshold. S6b, if the surface cooler is turned off, or the surface cooler is turned on but not in defrost mode or heating mode, then the basic antifreeze mode is the final antifreeze mode. S7, according to the final antifreeze mode, control the opening and closing of the drain valve and the first heating device.

2. The surface cooler antifreeze control method according to claim 1, characterized in that: The steps following step S1 and before step S5 include: S2a, If the surface cooler is turned on, the status of the drain valve is detected; S3a, If the drain valve is in the open state, it will operate normally; S4a, if the drain valve is in the closed state, the water temperature is obtained.

3. The surface cooler antifreeze control method according to claim 2, characterized in that: Step S5 includes: S51, if the water temperature is less than or equal to the first threshold temperature, then the basic antifreeze mode is the advanced antifreeze mode. S52, if the water temperature is greater than the first threshold temperature and less than or equal to the second threshold temperature, then the basic antifreeze mode is the medium antifreeze mode. S53, if the water temperature is greater than the second threshold temperature and less than or equal to the third threshold temperature, then the basic antifreeze mode is the low-level antifreeze mode.

4. The surface cooler antifreeze control method according to claim 3, characterized in that: Step S5 further includes: S54, if the water temperature is greater than the third threshold temperature and less than the fourth threshold temperature, then the basic antifreeze mode is the buffer antifreeze mode. S55, if the water temperature is greater than or equal to the fourth threshold temperature, then the basic antifreeze mode is to exit the antifreeze mode.

5. The surface cooler antifreeze control method according to claim 1, characterized in that: Step S7 includes: S71, if the final antifreeze mode is a high-level antifreeze mode, control the drain valve to open and the first heating device to open. S72, if the final antifreeze mode is medium antifreeze mode, control the drain valve to open and the first heating device to close. S73, if the final antifreeze mode is a low-level antifreeze mode, control the drain valve to close and the first heating device to turn on; S74, if the final antifreeze mode is a buffer antifreeze mode, keep the state of the drain valve and the first heating device unchanged; S75, if the final antifreeze mode is to exit antifreeze mode, control the drain valve to close and the first heating device to close.

6. The surface cooler antifreeze control method according to claim 5, characterized in that: It is also used to control the second heating device; It also includes step S8, which controls the second heating device to turn on and off based on the antifreeze duration; Step S8 includes: S81, obtain the antifreeze duration when the final antifreeze mode is high antifreeze mode; the antifreeze duration starts counting from the time point when the final antifreeze mode is high antifreeze mode, and is reset to zero after the final antifreeze mode changes to exit antifreeze mode. S82, if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is high antifreeze mode, control the second heating device to turn on; if the antifreeze duration exceeds the set antifreeze time threshold and the final antifreeze mode is medium antifreeze mode, low antifreeze mode or buffer antifreeze mode, keep the state of the second heating device unchanged; if the antifreeze duration is 0, control the second heating device to turn off.

7. The surface cooler antifreeze control method according to claim 1, characterized in that: It also includes step S4b0, which is executed before step S4b: if the shutdown duration is less than a preset duration, then obtain the water volume in the surface cooler pipe; Step S4b is replaced by: if the water volume is greater than or equal to the set water volume threshold, then obtain the water circuit temperature.

8. A surface cooler antifreeze control device, used to implement the surface cooler antifreeze control method according to any one of claims 1-7, to control the drain valve and the first heating device, characterized in that, include: The shutdown detection module is used to detect whether the surface cooler is powered on. The shutdown duration acquisition module is used to acquire the shutdown duration when the surface cooler is shut down; The drain valve opening module is used to control the drain valve to open when the shutdown duration is greater than or equal to a preset duration; The water circuit temperature acquisition module is used to acquire the water circuit temperature when the shutdown time is less than a preset time. The basic antifreeze mode determination module is used to obtain the basic antifreeze mode based on the water circuit temperature. The final antifreeze mode acquisition module is used to acquire the final antifreeze mode based on the basic antifreeze mode. The control module is used to control the opening and closing of the drain valve and the first heating device according to the final antifreeze mode.

9. A surface cooler, characterized in that: The device includes a control unit that performs the surface cooler antifreeze control method according to any one of claims 1-7 to prevent the pipes of the surface cooler from freezing and cracking.

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