Grain cooling machine and control method and system for grain cooling machine

Abstract

The invention provides a grain cooling machine and a control method and system for the grain cooling machine. The grain cooling machine at least comprises an air supply system, and the air supply system comprises a heat exchange device, an air outlet, an air inlet and an inner fan; the air outlet and the air inlet are connected through an air duct, and the inner fan is arranged on the air duct and used for generating air pressure in the air duct; the heat exchange device is arranged in the air duct and used for conducting heat exchange with air in the air duct. The air inlet is provided with an air return valve which is used for opening and closing the air inlet; an air outlet valve is arranged at the air outlet and is used for opening and closing the air outlet; the air duct is further provided with a fresh air opening, the fresh air opening is provided with a fresh air valve, and the fresh air valve is used for opening and closing the fresh air opening. The fresh air port is used for introducing a fresh air source of the air supply system in the cleaning mode of the air supply system. The problem that in the prior art, after a heat exchange device of a grain cooling machine is used for a period of time, parts are still prone to being corroded by phosphine gas is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of grain storage, and in particular to a grain cooler, a control method and system for the grain cooler. BACKGROUND

[0002] At present, in the process of storing grain in a grain depot, in order to ensure the safety of the grain, the environment of the grain depot needs to be adjusted regularly, and the grain in the grain depot needs to be handled, for example, the grain needs to be regularly treated by phosphine fumigation to eliminate pests and diseases therein; the grain depot needs to be cooled by a grain cooler to ensure that the grain in the grain depot is stored at a low temperature.

[0003] When the grain in the grain depot is handled, harmful gases (such as phosphine gas remaining in the grain depot after phosphine fumigation) remain in the grain depot, and when the grain depot is cooled by the grain cooler, the phosphine gas remaining in the grain depot enters the heat exchange device of the grain cooler along with the air, since the main material of the heat exchange device of the grain cooler is mostly copper, and the phosphine gas mostly has strong corrosive effect in a humid environment, which causes the copper parts to be corroded frequently.

[0004] In view of this problem, the main solutions at present include: electroplating corrosion-resistant coating of the copper parts of the heat exchange device, and selection of a motor with high sealing property for the copper motor, but none of them can completely solve the problem, and the problem of corrosion still exists after a period of use. Through analysis, the main reason is that these parts are in an environment containing phosphine gas for a long time, and the coating and sealing form cannot completely isolate the contact between the two, and corrosion still easily occurs at weak points and gradually expands the corrosion area. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a grain cooler, a control method and system for the grain cooler, which solves the problem that the heat exchange device of the grain cooler in the prior art is still prone to corrosion of the parts by phosphine gas after a period of use.

[0006] According to an embodiment of the present application, a grain cooler is provided, comprising at least an air supply system, the air supply system comprising a heat exchange device, an air outlet, an air inlet, an internal fan; the air outlet and the air inlet are connected by an air duct, the internal fan is arranged on the air duct and used to generate air pressure in the air duct; the heat exchange device is arranged in the air duct and used to exchange heat with the gas in the air duct; the air inlet is provided with a return air damper, the return air damper is used to open and close the air inlet; the air outlet is provided with an air outlet damper, the air outlet damper is used to open and close the air outlet; the air duct is further provided with a fresh air inlet, the fresh air inlet is provided with a fresh air damper, the fresh air damper is used to open and close the fresh air inlet; the fresh air inlet is used to introduce a fresh air source of the air supply system in a cleaning mode of the air supply system.

[0007] In another aspect, according to an embodiment of the present application, a control method for a grain cooler is also provided, the grain cooler uses the grain cooler described above, and the control method comprises the following steps:

[0008] S1, determining the operation mode of the grain cooler;

[0009] S2, based on the determined operation mode of the grain cooler, outputting the air supply system control strategy corresponding to the operation mode.

[0010] In still another aspect, according to an embodiment of the present application, a control system for a grain cooler is also provided, the control system comprises:

[0011] a temperature sensing probe arranged in a grain bin and used to collect temperature data in the grain bin;

[0012] a controller used to execute the control method of the grain cooler described above.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] By arranging the fresh air inlet on the air duct connected between the air inlet and the air outlet, when the air supply system is in the cleaning mode, the fresh air source required by the air supply system can be introduced from the fresh air inlet, the phosphine gas at the heat exchange device in the air duct is purged, and finally the phosphine gas purged out is discharged from the air outlet, so as to prevent the phosphine gas from staying on the surface of the heat exchange device, solve the problem that the heat exchange device of the grain cooler in the prior art is still prone to corrosion of parts by phosphine gas after being used for a period of time, greatly slow down the corrosion of the parts caused by the contact between the phosphine gas and the parts of the heat exchange device, so as to achieve the purpose of protecting the parts of the heat exchange device and prolonging the service life of the parts. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 This is a schematic diagram of the overall structure of a grain cooler in the prior art.

[0016] Figure 2 This is a schematic diagram of the installation structure of a grain cooler using existing technology.

[0017] Figure 3 This is a schematic diagram of the refrigeration cycle of a grain cooler in the prior art.

[0018] Figure 4 This is a schematic diagram of the overall structure of a grain cooler according to an embodiment of the present invention.

[0019] Figure 5 This is a schematic diagram of the installation structure of a grain cooler according to an embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the installation of the compressor in a grain cooler according to an embodiment of the present invention.

[0021] Figure 7 This is a schematic diagram of the installation of the internal fan of a grain cooler according to an embodiment of the present invention.

[0022] Figure 8 This is a schematic diagram of the installation of a finned heat exchanger for a grain cooler according to an embodiment of the present invention.

[0023] Figure 9 This is a flowchart illustrating the control method for a grain cooler according to another embodiment of the present invention.

[0024] In the above attached diagram: 1. Outdoor unit; 2. Indoor unit; 3. Wired controller; 4. Temperature sensor; 5. Controller; 6. Return air duct; 7. Air outlet duct; 8. Grain silo wall; 11. Compressor; 12. External fan; 21. Internal fan; 22. Air outlet; 23. Air inlet; 24. Fresh air inlet; 25. Finned heat exchanger; 26. Piping fittings; 27. Return air filter. Detailed Implementation

[0025] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] like Figures 1-3As shown, a prior art grain cooler includes an outdoor unit 1 and an indoor unit 2. The indoor unit 2 is mounted on the outdoor unit 1. The outdoor unit 1 contains a compressor 11 and an outdoor fan 12. The indoor unit 2 includes at least an air supply system, which includes a heat exchange device, an air outlet 22, an air inlet 23, and an indoor fan 21. The air outlet 22 and the air inlet 23 are connected by a duct. The indoor fan 21 is mounted on the duct and is used to generate air pressure within the duct. The heat exchange device is located within the duct and is used to exchange heat with the gas within the duct. Specifically, the air inlet 23 and the air outlet 22 are connected to the grain silo wall 8 via a return air duct 6 and an outlet air duct 7, allowing air from inside the grain silo to be transferred from the return air duct 6 to the outlet air duct 8. The air enters through the air inlet 23 and finally flows into the indoor unit 2. After passing through the indoor unit 2, it is discharged from the air outlet 22 into the air outlet duct 7, and finally discharged into the grain silo from the air outlet duct 7. The heat exchange device includes a finned heat exchanger 25, a pipe component 26 connected to the finned heat exchanger 25, and a return air filter 27. The heat exchange device is set in the air duct. The finned heat exchanger 25 includes an evaporator. When the indoor fan 21 is running, the air in the grain silo can be drawn to the heat exchange device in the air duct and exchange heat with the refrigerant at the heat exchange device, cooling the air in the grain silo. Finally, it is discharged into the grain silo from the air outlet 22, realizing the cooling of the grain silo interior.

[0027] During cooling, the compressor 11, the outdoor fan 12, and the indoor fan 21 operate. Air from the grain silo enters the indoor unit 2 through the air inlet 23 (the air pressure generated by the operation of the indoor fan 21 draws the air from the grain silo into the indoor unit 2). At the finned heat exchanger 25 (or evaporator) of the indoor unit 2, heat exchange occurs with the refrigerant, cooling the air. The air is then finally discharged into the grain silo through the air outlet 22. Meanwhile, the refrigerant absorbs heat from its low-temperature, low-pressure state and vaporizes into a low-pressure gas. At this point, the compressor 11 compresses the low-pressure gas into a high-temperature, high-pressure gas, which enters the condenser of the outdoor unit 1. On the surface of the condenser, the refrigerant exchanges heat with the outdoor air (the operation of the outdoor fan 12 draws the outdoor air into the condenser), releasing heat into the air. After heat exchange, the refrigerant liquefies into a high-temperature, high-pressure gas. Through the throttling and pressure-reducing effect of the throttling element, it becomes a low-temperature, low-pressure gas and enters the finned heat exchanger 25. This cycle continues, achieving cooling of the grain silo's interior. During the entire cooling process, air inside the grain silo is continuously transferred to the indoor unit 2. Since the air inside the grain silo generally contains at least a small amount of phosphine gas, this phosphine gas is transferred to the indoor unit 2 during the cooling process. Even with the electrophoretic anti-corrosion coating on the components of the heat exchange device in the indoor unit 2 and the use of a highly sealed motor, it is still impossible to completely prevent phosphine gas from contacting the components of the heat exchange device. As a result, after a period of use, the components of the heat exchange device are still prone to corrosion by phosphine gas.

[0028] To solve the above problems, such as Figures 4-8As shown in the figure, this embodiment of the invention proposes a grain cooler. The air inlet 23 is equipped with a return air valve for opening and closing the air inlet 23; the air outlet 22 is equipped with an outlet air valve for opening and closing the air outlet 22; a fresh air inlet 24 is also provided on the air duct, and the fresh air inlet 24 is equipped with a fresh air valve for opening and closing the fresh air inlet 24; the fresh air inlet 24 is used to introduce fresh air from the air supply system in the air supply system cleaning mode. The heat exchange device is installed in the pipe between the air inlet 23 and the internal fan 21. A fresh air inlet 24 is also installed on the pipe between the air inlet 23 and the internal fan 21. Specifically, the air supply system cleaning modes include a shutdown cleaning mode, a fumigation cleaning mode, and a timed cleaning mode. When in any of these three operating modes, the return air valve is closed, thus closing the air inlet 23 to prevent air from the grain silo from re-entering the air supply system. By opening the air outlet valve and the fresh air valve, the air outlet 22 and the fresh air inlet 24 are opened, and the internal fan 21 is operated. This generates air pressure in the air duct, drawing outdoor air from the fresh air inlet 24 into the heat exchange device. This purges the phosphine gas in the heat exchange device, removing any residual phosphine gas. The purged phosphine gas is then discharged from the air outlet 22 into the grain silo, preventing phosphine gas from lingering on the surface of the heat exchange device. (The fresh air source introduced into the air supply system can purge not only phosphine gas but also other harmful gases simultaneously.) This solves the problem in existing grain coolers where heat exchange devices are prone to corrosion by phosphine gas after a period of use. It significantly reduces the contact between phosphine gas and the components of the heat exchange device, thus protecting the components and extending their service life.

[0029] like Figure 9 As shown, in another aspect, this embodiment of the invention also proposes a control method for a grain cooler, wherein the grain cooler employs the grain cooler described above, and the control method includes the following steps:

[0030] S1. Determine the operating mode of the grain cooler;

[0031] S2. Based on the determined operating mode of the grain cooler, output the control strategy of the air supply system corresponding to the operating mode.

[0032] S1 includes:

[0033] Acquire the operating status information of the grain cooler and the temperature data inside the grain silo;

[0034] The operating mode of the grain cooler is obtained based on the working status information and the temperature data.

[0035] Specifically, a temperature probe 4 (or a temperature sensor) is installed inside the grain silo to collect temperature data in real time. Since the grain silo needs to be maintained within a relatively low temperature range (generally 15-22℃), the preset temperature threshold should also be within this range when collecting temperature data. To collect the operating signals of the compressor 11, the external fan 12, and the internal fan 21, an accelerometer can be installed at the compressor 11 to detect its vibration value. Sound level meters can be installed at the external fan 12 and the internal fan 21 to detect their noise levels. The system collects the operating signals of the compressor 11, the external fan 12, and the internal fan 21. After collection, the operating mode of the grain cooler is determined based on the operating signals of the compressor 11, the external fan 12, the internal fan 21, the input command of the wired controller 3, and the grain silo temperature data. This allows the grain cooler to enter an anti-corrosion state when the refrigeration is stopped, after fumigation, and in standby mode. Compared with traditional anti-corrosion operations, this reduces the contact time of phosphine gas in the grain silo at the heat exchange device of the grain cooler, thus preventing phosphine gas from corroding the components of the heat exchange device.

[0036] The operating status information includes the compressor 11 operating signal, the external fan 12 operating signal, and the internal fan 21 operating signal;

[0037] The operating mode is determined in the control method as follows:

[0038] When the obtained grain silo temperature is higher than the preset temperature threshold, and the compressor 11 operation signal, the external fan 12 operation signal, and the internal fan 21 operation signal are obtained at the same time, the grain cooler is determined to be in normal cooling mode.

[0039] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0040] Close the fresh air valve, and open the return air valve and the outlet air valve, then run the compressor 11, the outdoor fan 12 and the indoor fan 21.

[0041] Specifically, when the grain silo temperature is detected to be higher than the preset temperature threshold, and the compressor 11, the external fan 12, and the internal fan 21 are simultaneously detected to be running, the compressor 11, the external fan 12, and the internal fan 21 are all in operation. At this time, the grain cooler is determined to be in normal cooling mode. The corresponding air supply system control strategy in this operating mode is as follows: first, close the fresh air valve, and then open the return air valve and the outlet air valve (when the outlet air valve, return air valve, and fresh air valve are open, their opening degree is 100%, and when closed, the leakage rate of the gas passing through the outlet 22, the inlet 23, or the fresh air outlet 24 is ≤1×10-6 Pa·m). 3 / s), causing the fresh air inlet 24 to close, and the air inlet 23 and the air outlet 22 to open. Then, the compressor 11, the outdoor fan 12 and the indoor fan 21 are run. The air in the grain silo enters the air duct through the air inlet 23. At the finned heat exchanger 25 in the air duct, heat exchange occurs with the refrigerant to cool the air, and finally the air is discharged into the grain silo from the air outlet 22. The refrigerant absorbs heat from the low temperature and low pressure liquid and vaporizes into a low pressure gas. At this time, through the work of the compressor 11, the low pressure gas is compressed into a high temperature and high pressure gas and enters the condenser of the outdoor unit 1. On the surface of the condenser, the refrigerant exchanges heat with the outdoor air and releases heat into the air. After the heat exchange, the refrigerant liquefies into a high temperature and high pressure gas. Through the throttling and pressure reduction effect of the throttling element, it becomes a low temperature and low pressure gas and enters the finned heat exchanger 25. This cycle continues, realizing the cooling of the grain silo interior.

[0042] The operating status information includes the compressor 11 operating signal, the external fan 12 operating signal, and the internal fan 21 operating signal;

[0043] The operating mode is determined in the control method as follows:

[0044] When the obtained grain silo temperature reaches the preset temperature threshold, or when the compressor 11 is found to have stopped abnormally, the operating mode of the grain cooler is determined to be the shutdown cleaning mode.

[0045] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0046] Turn off the external fan 12, then close the return air valve, open the fresh air valve and the outlet air valve, run the internal fan 21 to purge the phosphine gas at the heat exchange device, and after the first preset time is reached, stop running the internal fan 21 and close the fresh air valve and the outlet air valve.

[0047] Specifically, when the grain silo temperature is detected to reach a preset temperature threshold (overheating shutdown), or when an abnormal shutdown of compressor 11 is detected, the grain cooler is determined to be in a shutdown cleaning mode. In this operating mode, the corresponding air supply system control strategy is as follows: the external fan 12 is shut down, the return air valve is closed, the fresh air valve and the outlet air valve are opened, and the internal fan 21 is operated, allowing outdoor air to enter the duct from the fresh air inlet 24. After passing through the return air filter 27 installed in the duct (to filter out dust and other impurities in the air), the air exchanger in the duct... The surface of the heat exchanger is purged to remove residual phosphine gas. The purged phosphine gas is then discharged from the air outlet 22 into the grain silo along with the purged phosphine gas. This directional, unidirectional airflow purging removes the phosphine gas from the heat exchanger. Compared to traditional corrosion prevention methods, this method prevents phosphine gas from lingering on the surface of the heat exchanger, significantly reducing the risk of corrosion caused by contact between the phosphine gas and the components. This protects the components and extends their service life.

[0048] When the purging time reaches the first preset time, the internal fan 21 is stopped, and the fresh air valve and the outlet air valve are closed, so that the fresh air inlet 24 and the outlet airlet 22 are closed to prevent phosphine gas in the grain silo from entering the air duct from the outlet airlet 22 and adhering to the surface of the heat exchange device in the air duct, causing corrosion of the components of the heat exchange device.

[0049] Furthermore, in order to more thoroughly purge the phosphine gas from the heat exchanger in the air duct, an electrochemical / infrared composite sensor (such as an ME3-PH3 sensor or a PH3 / M series probe) can be installed on the surface of the heat exchanger to monitor the concentration of phosphine gas on the surface of the heat exchanger in real time. The first preset time is dynamically adjusted according to the concentration of phosphine gas on the surface of the heat exchanger until the concentration of phosphine gas on the surface of the heat exchanger reaches zero, thereby stopping the purging and preventing phosphine gas from corroding the components of the heat exchanger.

[0050] The operating status information includes the compressor 11 operating signal, the external fan 12 operating signal, and the internal fan 21 operating signal;

[0051] The operating mode is determined in the control method as follows:

[0052] When the obtained grain silo temperature is lower than the preset temperature threshold, and the compressor 11, external fan 12 and internal fan 21 are found to be shut down normally, the grain cooler is determined to be in standby anti-corrosion mode.

[0053] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0054] Close the outlet air valve and return air valve, and keep them in the normally closed state.

[0055] Specifically, when the grain silo temperature is detected to be lower than the preset temperature threshold (over-temperature shutdown), and the compressor 11, the external fan 12, and the internal fan 21 are detected to have stopped normally, the grain cooler is determined to be in standby anti-corrosion mode. In this operating mode, the corresponding air supply system control strategy is as follows: first, close the air outlet valve and the air return valve and keep them in a normally closed state, so that the air outlet 22 and the air inlet 23 are closed, so as to prevent phosphine gas in the grain silo from entering the air duct of the grain cooler from the air outlet 22 and the air inlet 23 and adhering to the surface of the heat exchange device in the air duct, causing corrosion of the components of the heat exchange device.

[0056] The working status information includes input commands from the wired controller 3;

[0057] The operating mode is determined in the control method as follows:

[0058] When the input command of the wired controller 3 is fumigation protection, the operating mode of the grain cooler is determined to be fumigation protection mode;

[0059] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0060] Turn off compressor 11, outdoor fan 12 and indoor fan 21, and then close the air outlet valve, air return valve and fresh air valve.

[0061] Specifically, a fumigation protection command is manually input into the wired controller 3. The wired controller 3 then transmits this input command to the grain cooler, causing the grain cooler to switch its operating mode to fumigation protection mode. In this operating mode, the corresponding air supply system control strategy is as follows: first, the compressor 11, the external fan 12, and the internal fan 21 are shut down; then, the outlet air valve, the return air valve, and the fresh air valve are shut down, so that the outlet 22, the inlet 23, and the fresh air inlet 24 are all closed. This prevents phosphine gas in the grain silo from entering the air duct of the grain cooler through the outlet 22 and the inlet 23 and adhering to the surface of the heat exchange device in the air duct, causing corrosion of the heat exchange device components.

[0062] The working status information includes input commands from the wired controller 3;

[0063] The operating mode is determined in the control method as follows:

[0064] When the input command to the wired controller 3 is fumigation and cleaning, the operating mode of the grain cooler is determined to be fumigation and cleaning mode;

[0065] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0066] Open the fresh air valve and the outlet air valve, run the internal fan 21 to purge the phosphine gas at the heat exchange device, and after the second preset time is reached, stop running the internal fan 21 and close the fresh air valve and the outlet air valve.

[0067] Specifically, a fumigation cleaning command is manually input into the wired controller 3. The wired controller 3 then transmits this command to the grain cooler, switching the grain cooler's operating mode to fumigation cleaning mode. In this mode, the corresponding air supply system control strategy is as follows: first, the fresh air valve and the outlet air valve are opened; then, the internal fan 21 is run, allowing outdoor air to enter the duct from the fresh air inlet 24. After passing through the return air filter 27 installed in the duct (to remove dust and other impurities), the air then cleans the surfaces of the pipe components 26 and the finned heat exchanger 25 within the duct. The purging process removes residual phosphine gas from the surfaces of the pipe components 26 and the finned heat exchanger 25, and the removed phosphine gas is then discharged from the outlet 22 into the grain silo. This directional, unidirectional airflow purging removes phosphine gas from the pipe components 26 and the finned heat exchanger 25. Compared to traditional corrosion prevention methods, this method prevents phosphine gas from lingering on the surface of the heat exchanger, significantly reducing the risk of corrosion caused by contact between phosphine gas and the components. This protects the components and extends their service life.

[0068] When the purging time reaches the second preset time, the internal fan 21 is stopped, and the fresh air valve and the outlet air valve are closed, so that the fresh air inlet 24 and the outlet airlet 22 are closed to prevent phosphine gas in the grain silo from entering the air duct from the outlet airlet 22 and adhering to the surface of the heat exchange device in the air duct, causing corrosion of the components of the heat exchange device.

[0069] Furthermore, in order to more thoroughly purge the phosphine gas from the heat exchanger in the air duct, an electrochemical / infrared composite sensor (such as an ME3-PH3 sensor or a PH3 / M series probe) can be installed on the surface of the heat exchanger to monitor the concentration of phosphine gas on the surface of the heat exchanger in real time. The second preset time is dynamically adjusted according to the concentration of phosphine gas on the surface of the heat exchanger until the concentration of phosphine gas on the surface of the heat exchanger reaches zero, thereby stopping the purging and preventing phosphine gas from corroding the components of the heat exchanger.

[0070] The working status information includes input commands from the wired controller 3;

[0071] The operating mode is determined in the control method as follows:

[0072] When the input command for the wired controller 3 is timed cleaning, the operating mode of the grain cooler is determined to be timed cleaning mode;

[0073] In the control method, the air supply system control strategy corresponding to the operating mode includes:

[0074] A fresh air purge is performed every third preset time interval. At this time, the return air valve is closed, the fresh air valve and the outlet air valve are opened, and the internal fan 21 is run to purge the phosphine gas at the heat exchange device.

[0075] During the purging process, the temperature inside the grain silo is monitored in real time, and purging is stopped when the temperature exceeds a preset temperature threshold of 1°C or reaches a fourth preset time.

[0076] Specifically, a timed cleaning command is manually input into the wired controller 3. The wired controller 3 then transmits this input command to the grain cooler, switching the operating mode of the grain cooler to the timed cleaning mode. In this operating mode, the corresponding air supply system control strategy is as follows: a fresh air cleaning is performed every third preset time interval. At this time, the return air valve is closed, the fresh air valve and the outlet air valve are opened, and the internal fan 21 is run to purge the phosphine gas at the heat exchange device. This prevents the phosphine gas from lingering on the surface of the heat exchange device, thereby greatly reducing the contact between the phosphine gas and the components of the heat exchange device, which could lead to corrosion of the components. This effectively protects the components of the heat exchange device and extends their service life.

[0077] During the purging process, the temperature inside the grain silo is monitored in real time. When the temperature inside the grain silo exceeds the preset temperature threshold by 1°C or reaches the fourth preset time (priority is the grain silo temperature), the purging is stopped. By stopping the purging when the temperature inside the grain silo exceeds the preset temperature threshold by 1°C, the purging is stopped as soon as the grain silo temperature exceeds the preset temperature threshold by 1°C, so that the operating mode of the grain cooler can be switched to the normal cooling mode to cool the inside of the grain silo. The third preset time is longer than the fourth preset time, and the temperature threshold ranges from 15 to 22°C.

[0078] Furthermore, if the outlet air valve, the return air valve, or the fresh air valve cannot be opened or closed normally in any operating mode of the grain cooler, the grain cooler will stop operating, and the wired controller 3 will display a fault code until the fault is cleared.

[0079] Specifically, in any of the above operating modes, if the outlet air valve, the return air valve, or the fresh air valve cannot open or close normally, the power supply to the compressor 11 will be immediately cut off, and the operation of the indoor fan 21 and the outdoor fan 12 will be stopped. At the same time, the fault code will be transmitted to the wired controller 3 for display (e.g., the fault code for the outlet air valve is E01, the fault code for the return air valve is E02, and the fault code for the fresh air valve is E03) so that the user can check the fault situation until the fault is eliminated. After the fault is eliminated, the "RESET" button on the wired controller 3 should be pressed and held for 3 seconds to clear the fault memory, and then the power should be turned on again to allow the outlet air valve, the return air valve, or the fresh air valve to automatically execute the self-test program. Only after the self-test is completed can any of the above operating modes be executed.

[0080] The detailed working process of this embodiment is as follows:

[0081] The system collects the operating signals of the compressor 11, the external fan 12, the internal fan 21, the input command of the wired controller 3, and the temperature data inside the grain silo. Based on these signals, the operating mode of the grain cooler is determined. When the operating mode is a shutdown cleaning mode, a fumigation cleaning mode, or a timed cleaning mode, a fresh air purging is performed. At this time, the return air valve is closed, causing the air inlet 23 to be closed to prevent air from the grain silo from re-entering the air duct of the grain cooler. Then, the outlet air valve and the fresh air valve are opened, allowing the outlet 22 and the fresh air inlet to open. When 24 is opened, the internal fan 21 is activated, generating air pressure within the duct. This draws outdoor air into the duct from the fresh air inlet 24, where it is filtered through the return air filter 27 (to remove dust and other impurities). The air then blows through the pipe components 26 and the finned heat exchanger 25 within the duct, removing any residual phosphine gas. Finally, the blown-off phosphine gas is discharged from the outlet 22 into the grain silo, preventing phosphine gas from lingering on the surface of the heat exchanger. This significantly reduces the risk of corrosion caused by contact between phosphine gas and the components, thus protecting the components and extending their service life.

[0082] Furthermore, embodiments of the present invention also provide a control system for a grain cooler, the control system comprising:

[0083] Temperature sensor 4 is installed inside the grain silo to collect temperature data inside the grain silo.

[0084] Controller 5 is used to execute the control method of the grain cooler described above.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A grain cooler, comprising at least an air supply system, the air supply system including a heat exchange device, an air outlet, an air inlet, and an internal fan; the air outlet and the air inlet are connected by an air duct, the internal fan is disposed on the air duct and is used to generate air pressure within the air duct; the heat exchange device is disposed within the air duct and is used to exchange heat with the gas within the air duct; characterized in that... The air inlet is equipped with a return air valve, which is used to open and close the air inlet; the air outlet is equipped with an outlet air valve, which is used to open and close the air outlet; a fresh air inlet is also provided on the air duct, and a fresh air inlet is equipped with a fresh air valve, which is used to open and close the fresh air inlet; the fresh air inlet is used to introduce fresh air from the air supply system in the air supply system cleaning mode.

2. A grain cooler according to claim 1, characterized in that, The heat exchange device is installed in the pipe between the air inlet and the internal fan, and the fresh air outlet is also installed on the pipe between the air inlet and the internal fan.

3. A control method for a grain cooler, wherein the grain cooler is the grain cooler according to claim 1 or 2, characterized in that: The control method includes the following steps: S1. Determine the operating mode of the grain cooler; S2. Based on the determined operating mode of the grain cooler, output the control strategy of the air supply system corresponding to the operating mode.

4. The control method according to claim 3, characterized in that, S1 includes: Acquire the operating status information of the grain cooler and the temperature data inside the grain silo; The operating mode of the grain cooler is obtained based on the working status information and the temperature data.

5. The control method according to claim 4, characterized in that, The operating status information includes compressor operation signal, external fan operation signal, and internal fan operation signal; The operating mode is determined in the control method as follows: When the obtained grain silo temperature is higher than the preset temperature threshold, and the compressor operation signal, the external fan operation signal, and the internal fan operation signal are obtained at the same time, the grain cooler is determined to be in normal cooling mode. In the control method, the air supply system control strategy corresponding to the operating mode includes: Close the fresh air valve, and open the return air valve and the outlet air valve, then run the compressor, outdoor fan and indoor fan.

6. The control method according to claim 4, characterized in that, The operating status information includes compressor operation signal, external fan operation signal, and internal fan operation signal; The operating mode is determined in the control method as follows: When the obtained grain silo temperature reaches the preset temperature threshold, or when the compressor stops abnormally, the operating mode of the grain cooler is determined to be the shutdown cleaning mode. In the control method, the air supply system control strategy corresponding to the operating mode includes: Turn off the external fan, then close the return air valve, open the fresh air valve and the outlet air valve, run the internal fan to purge the phosphine gas at the heat exchange device, and after the first preset time is reached, stop running the internal fan and close the fresh air valve and the outlet air valve.

7. The control method according to claim 4, characterized in that, The operating status information includes compressor operation signal, external fan operation signal, and internal fan operation signal; The operating mode is determined in the control method as follows: When the obtained grain silo temperature is lower than the preset temperature threshold, and the compressor, external fan and internal fan are found to be shut down normally, the grain cooler is determined to operate in standby anti-corrosion mode. In the control method, the air supply system control strategy corresponding to the operating mode includes: Close the outlet air valve and return air valve, and keep them in the normally closed state.

8. The control method according to claim 4, characterized in that, The working status information includes the input commands from the wired controller; The operating mode is determined in the control method as follows: When the input command from the wired controller is fumigation protection, the operating mode of the grain cooler is determined to be fumigation protection mode. In the control method, the air supply system control strategy corresponding to the operating mode includes: Turn off the compressor, outdoor fan, and indoor fan, and then close the outlet air valve, return air valve, and fresh air valve.

9. The control method according to claim 4, characterized in that, The working status information includes the input commands from the wired controller; The operating mode is determined in the control method as follows: When the input command to the wired controller is fumigation and cleaning, the operating mode of the grain cooler is determined to be fumigation and cleaning mode; In the control method, the air supply system control strategy corresponding to the operating mode includes: Open the fresh air valve and the outlet air valve, run the internal fan to purge the phosphine gas at the heat exchange device, and after the second preset time is reached, stop running the internal fan and close the fresh air valve and the outlet air valve.

10. The control method according to claim 4, characterized in that, The working status information includes the input commands from the wired controller; The operating mode is determined in the control method as follows: When the wired controller inputs a timed cleaning command, the operating mode of the grain cooler is determined to be the timed cleaning mode. In the control method, the air supply system control strategy corresponding to the operating mode includes: A fresh air purge is performed every third preset time interval. At this time, the return air valve is closed, the fresh air valve and the outlet air valve are opened, and the internal fan is run to purge the phosphine gas at the heat exchange device. During the purging process, the temperature inside the grain silo is monitored in real time, and purging is stopped when the temperature exceeds a preset temperature threshold of 1°C or reaches a fourth preset time.

11. A control system for a grain cooler, characterized in that: The control system includes: Temperature sensors are installed inside the grain silo to collect temperature data. A controller for performing the control method of the grain cooler as described in any one of claims 3-10.

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